Eurosymposium on Healthy Ageing
A new age of long term health and longevity
Brussels, October 1st 2014
1
Advanced Glycation End-products as therapeutic targets: prevent, remove or ignore?
William Bains
MIT, USA
Long-lived proteins in cells and in the extracellular matrix accumulate chemical changes with life, resulting in changes in function, usually deleterious. One of the most common forms of change is glycation, the chemical reactions of proteins with sugars which ultimately generate Advanced Glycation Endproducts (AGEs). AGEs have significant physiological effects through changing or degrading protein function, stimulating a variety of inflammatory and other physiological systems, and cross-linking proteins to reduce flexibility and turnover. I will describe the chemistry of AGEs, their potential route to causing age-associated disability and pathology, and evidence that they actually are associated with disease. A variety of approaches have been suggested to block the formation of AGEs and to remove them once they have formed, respectively being approaches to retarding and reversing an underlying cause of disabilities such as reduced tendon mechanics and age-associated increase in systolic blood pressure, and diseases such as diabetic nephropathy. A large amount of animal experimentation and uncontrolled (and often anecdotal) human testing has been done on AGE-blocker and AGE-breaker treatments, and a small amount of controlled clinical research. I will critically review work this work, suggest why there has been little clinical progress to date in AGE biology, and conclude whether AGEs are a problem that is best prevented, removed or ignored.
Advanced Glycation End-products as therapeutic targets: prevent, remove or ignore?
William Bains
MIT, USA
Long-lived proteins in cells and in the extracellular matrix accumulate chemical changes with life, resulting in changes in function, usually deleterious. One of the most common forms of change is glycation, the chemical reactions of proteins with sugars which ultimately generate Advanced Glycation Endproducts (AGEs). AGEs have significant physiological effects through changing or degrading protein function, stimulating a variety of inflammatory and other physiological systems, and cross-linking proteins to reduce flexibility and turnover. I will describe the chemistry of AGEs, their potential route to causing age-associated disability and pathology, and evidence that they actually are associated with disease. A variety of approaches have been suggested to block the formation of AGEs and to remove them once they have formed, respectively being approaches to retarding and reversing an underlying cause of disabilities such as reduced tendon mechanics and age-associated increase in systolic blood pressure, and diseases such as diabetic nephropathy. A large amount of animal experimentation and uncontrolled (and often anecdotal) human testing has been done on AGE-blocker and AGE-breaker treatments, and a small amount of controlled clinical research. I will critically review work this work, suggest why there has been little clinical progress to date in AGE biology, and conclude whether AGEs are a problem that is best prevented, removed or ignored.
2
The role of telomeres in aging and the potential of telomerase activation to delay disease and increase health-span.
Christian Bär and María A. BlascoSpanish National Cancer Research Centre, Spain
Telomeres are nucleoprotein complexes which protect the ends of linear chromosomes and which play a pivotal role in cellular and organismal ageing. Over the past two decades short telomeres have been associated with a large disease spectrum including degenerative diseases and cancer. Our laboratory has made significant contributions to dissect the role of telomerase and telomere length as one of the key molecular pathways underlying cancer and aging. We previously demonstrated that telomerase activation by means of transgenesis as well as vector-based gene therapy has beneficial effects on a variety of age-related pathologies and survival in wild-type mice. We are currently exploring telomerase treatment strategies in mouse models of diseases related to the presence of short telomeres including models for myocardial infarction and aplastic anaemia.
The role of telomeres in aging and the potential of telomerase activation to delay disease and increase health-span.
Christian Bär and María A. BlascoSpanish National Cancer Research Centre, Spain
Telomeres are nucleoprotein complexes which protect the ends of linear chromosomes and which play a pivotal role in cellular and organismal ageing. Over the past two decades short telomeres have been associated with a large disease spectrum including degenerative diseases and cancer. Our laboratory has made significant contributions to dissect the role of telomerase and telomere length as one of the key molecular pathways underlying cancer and aging. We previously demonstrated that telomerase activation by means of transgenesis as well as vector-based gene therapy has beneficial effects on a variety of age-related pathologies and survival in wild-type mice. We are currently exploring telomerase treatment strategies in mouse models of diseases related to the presence of short telomeres including models for myocardial infarction and aplastic anaemia.
3
Growth hormone and methionine: Are these factors linked to aging and longevity?
Holly Brown-Borg
Department of Basic Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND 58203 USA.
Endocrine hormones impact aging and aging processes in multiple ways. Circulating growth hormone (GH) affects not only somatic growth but also drives aspects of metabolism and stress resistance. We have shown that GH modulates methionine metabolism and longevity in GH mutant mice. Our current studies focus on delineating the relationships between dietary methionine, methionine metabolism and plasma GH levels. Long living Ames dwarf, GH receptor knock out and short-living GH transgenic mice were subjected to different levels of dietary methionine in short-term (8 weeks) and long-term (lifetime) studies. Methionine metabolism, plasma IGF1, body weights, food consumption, end of life pathology and lifespan were examined. Methionine conserving and catabolizing enzymes were differentially affected by dietary methionine level. Underlying GH status also influenced the metabolic responses to alterations of this amino acid. We observed that long-living GH signaling deficient (Ames, GHRKO) mice were not able to discriminate differences in dietary methionine in terms of lifespan, food consumption and body weight. GH transgenic mice and the wild type mice from each line lived longer when fed methionine-restricted but not methionine-supplemented diets. These studies indicate that GH status affects the ability to respond to dietary methionine and downstream aspects of metabolism ultimately affecting health and lifespan.
Growth hormone and methionine: Are these factors linked to aging and longevity?
Holly Brown-Borg
Department of Basic Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND 58203 USA.
Endocrine hormones impact aging and aging processes in multiple ways. Circulating growth hormone (GH) affects not only somatic growth but also drives aspects of metabolism and stress resistance. We have shown that GH modulates methionine metabolism and longevity in GH mutant mice. Our current studies focus on delineating the relationships between dietary methionine, methionine metabolism and plasma GH levels. Long living Ames dwarf, GH receptor knock out and short-living GH transgenic mice were subjected to different levels of dietary methionine in short-term (8 weeks) and long-term (lifetime) studies. Methionine metabolism, plasma IGF1, body weights, food consumption, end of life pathology and lifespan were examined. Methionine conserving and catabolizing enzymes were differentially affected by dietary methionine level. Underlying GH status also influenced the metabolic responses to alterations of this amino acid. We observed that long-living GH signaling deficient (Ames, GHRKO) mice were not able to discriminate differences in dietary methionine in terms of lifespan, food consumption and body weight. GH transgenic mice and the wild type mice from each line lived longer when fed methionine-restricted but not methionine-supplemented diets. These studies indicate that GH status affects the ability to respond to dietary methionine and downstream aspects of metabolism ultimately affecting health and lifespan.
4
Chemical tools to study AGEing
Sven Bulterijs
Heales VZW, Belgium
The reaction between reducing sugars, reactive intermediates of metabolism and lipid peroxidation products with proteins produces a diversity of chemical modifications collectively known as advanced glycation end products (AGEs). AGEs accumulate in extracellular proteins with age and their accumulation has been suspected to be involved in the pathophysiology of cardiovascular disease, diabetic nephropathy, osteoporosis, Alzheimer’s disease and cataract. The biological study of these AGE-modifications has been hampered by the lack of chemically pure samples of single AGE products. In this presentation we illustrate the chemical synthesis of methylglyoxal-derived hydroimidazolones (MG-Hs), glyoxal lysine dimer (GOLD), methylglyoxal lysine dimer (MOLD), and glucosepane. We illustrate the unexpected pH-dependent antioxidant activity of MG-H3. Surprisingly, after oxidation the formed MG-I3 spontaneously hydrolyzes to produce the fully unmodified arginine residue and pyruvate. Due to the recent successful synthesis of chemically pure glucosepane for the first time we are able to probe the chemistry and biology of the most abundant protein cross-link found in vivo. Finally, we also show the development of a fluorescence-based chemical sensor to measure intracellular methylglyoxal levels in vivo.
5
Geroprotectors; of mice and men
Edouard Debonneuil
International Longevity Alliance
Now that we rarely die from infectious diseases, long term health is the new health challenge; or rather, how to address it. One approach is to test in short lived mammals -- mice -- the most promising interventions.
Those may be existing drugs that appear to be beneficial in humans, genetic therapies that come from human longevity genetic variants, or interventions that come from various universes and are more subject to differences between mice and humans.
Within the International Longevity Alliance we are voluntarily listing such candidates to be tested, in the hope to stimulate an industry of long term health and longevity, through a "Major Mouse Testing Program" and to benefit currently ageing populations.
Geroprotectors; of mice and men
Edouard Debonneuil
International Longevity Alliance
Now that we rarely die from infectious diseases, long term health is the new health challenge; or rather, how to address it. One approach is to test in short lived mammals -- mice -- the most promising interventions.
Those may be existing drugs that appear to be beneficial in humans, genetic therapies that come from human longevity genetic variants, or interventions that come from various universes and are more subject to differences between mice and humans.
Within the International Longevity Alliance we are voluntarily listing such candidates to be tested, in the hope to stimulate an industry of long term health and longevity, through a "Major Mouse Testing Program" and to benefit currently ageing populations.
6
Activation of an endogenous metabolic pathway extends health- and lifespan
Martin S. Denzel, Nadia J. Storm, Adam Antebi
Max Planck Institute for Biology of Ageing
Joseph-Stelzmann-Str. 9b
D-50931 Cologne
Germany
Demographic changes over the last 100 years have led to increased life expectancy, but also to ageing populations with an increased burden of age-associated disease. Diseases such as Alzheimer’s are a major health care challenge. Neurodegeneration can arise when normal quality control mechanisms fail to remove misfolded toxic proteins, leading to cellular dysfunction. Given the enormity of the problem, novel approaches for combatting neurodegeneration are desperately needed. Using a simple animal model, the roundworm Caenorhabditis elegans, we identified novel regulators that enhance protein quality control, ameliorate models of neurodegeneration, and extend life span. We found that activation of an enzyme that produces endogenous compounds called hexosamines, results in elevated cellular protein quality control. Interestingly, not only genetic activation of this enzymatic pathway, but also supplementation with hexosamines ameliorated age-related protein toxicity in C. elegans and extended its life span. The hexosamine pathway is also essential in mammalian cells and likewise counter neurodegeneration in higher animals and humans. In this talk, I will highlight how basic research into the genetics of ageing in C. elegans may be of use in the fight against neurodegeneration in people.
Activation of an endogenous metabolic pathway extends health- and lifespan
Martin S. Denzel, Nadia J. Storm, Adam Antebi
Max Planck Institute for Biology of Ageing
Joseph-Stelzmann-Str. 9b
D-50931 Cologne
Germany
Demographic changes over the last 100 years have led to increased life expectancy, but also to ageing populations with an increased burden of age-associated disease. Diseases such as Alzheimer’s are a major health care challenge. Neurodegeneration can arise when normal quality control mechanisms fail to remove misfolded toxic proteins, leading to cellular dysfunction. Given the enormity of the problem, novel approaches for combatting neurodegeneration are desperately needed. Using a simple animal model, the roundworm Caenorhabditis elegans, we identified novel regulators that enhance protein quality control, ameliorate models of neurodegeneration, and extend life span. We found that activation of an enzyme that produces endogenous compounds called hexosamines, results in elevated cellular protein quality control. Interestingly, not only genetic activation of this enzymatic pathway, but also supplementation with hexosamines ameliorated age-related protein toxicity in C. elegans and extended its life span. The hexosamine pathway is also essential in mammalian cells and likewise counter neurodegeneration in higher animals and humans. In this talk, I will highlight how basic research into the genetics of ageing in C. elegans may be of use in the fight against neurodegeneration in people.
7
Ageing of the human immune system in health and disease
K.S.M van der Geest, W. Abdulahad, E Brouwer and A.M.H. Boots
Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands
Age is the most important risk factor for the development of infection, cancer and chronic inflammatory diseases. A decline in immune function is thought to underlie the increased morbidity with age. Yet, healthy elderly present living proof that appropriate immune responses can be maintained for extended periods. We hypothesized that physical resilience in healthy elderly is associated with immune resilience and that markers of a healthy immune system may be identified in healthy elderly. Insight into the maintenance of naïve T cells is essential to understand defective immune responses in the context of aging and other immune compromised states. Thymus involution drastically reduces the production of novel T cells in adult humans. Post thymic maintenance of the naive T cell pool therefore relies on low grade proliferation and long-term survival of already existing naive T cells in the periphery. Naïve CD4 T cells, in contrast to CD8, are remarkably well-retained in aged humans. Our studies reveal a unique mechanism for preservation of the naïve CD4+ T cell repertoire with age. Our data provide novel insight into the homeostasis of naïve T cells. Naïve T cells may be used to monitor immune resilience in aged humans and may guide the development of therapies to preserve or restore immunity in the elderly.
Email: [email protected]
Ageing of the human immune system in health and disease
K.S.M van der Geest, W. Abdulahad, E Brouwer and A.M.H. Boots
Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands
Age is the most important risk factor for the development of infection, cancer and chronic inflammatory diseases. A decline in immune function is thought to underlie the increased morbidity with age. Yet, healthy elderly present living proof that appropriate immune responses can be maintained for extended periods. We hypothesized that physical resilience in healthy elderly is associated with immune resilience and that markers of a healthy immune system may be identified in healthy elderly. Insight into the maintenance of naïve T cells is essential to understand defective immune responses in the context of aging and other immune compromised states. Thymus involution drastically reduces the production of novel T cells in adult humans. Post thymic maintenance of the naive T cell pool therefore relies on low grade proliferation and long-term survival of already existing naive T cells in the periphery. Naïve CD4 T cells, in contrast to CD8, are remarkably well-retained in aged humans. Our studies reveal a unique mechanism for preservation of the naïve CD4+ T cell repertoire with age. Our data provide novel insight into the homeostasis of naïve T cells. Naïve T cells may be used to monitor immune resilience in aged humans and may guide the development of therapies to preserve or restore immunity in the elderly.
Email: [email protected]
8
Somatic mutations found in the healthy blood compartment of a 115-year-old woman demonstrate oligoclonal hematopoiesis.
Holstege H, Pfeiffer W, Sie D, Hulsman M, Nicholas TJ, Lee CC, Ross T, Lin J, Miller MA, Ylstra B, Meijers-Heijboer H, Brugman MH, Staal FJT, Holstege G, Reinders MJT, Harkins TT, Levy S, Sistermans EA.
Genetic mutations are commonly studied because of links to diseases such as cancer; however, little is known about mutations occurring in healthy individuals. We used whole genome sequencing of the white blood cells from a 115-year-old woman to determine if, over a long lifetime, mutations accumulate in healthy white blood cells.
Our blood is continually replenished by hematopoietic stem cells that reside in the bone marrow and divide to generate different types of blood cells. Cell division, however, is error-prone, and cells that frequently divide, such as blood cells, are more likely to accumulate genetic mutations. Hundreds of mutations have been found in patients with blood cancers such as acute myeloid leukemia (AML), but it is unclear whether healthy white blood cells also harbor mutations.
We identified over 450 mutations in the healthy white blood cells of the 115 year old woman that were not found in her brain, a tissue which rarely undergoes cell division after birth. These mutations, known as somatic mutations because they are not passed on to offspring, appear to be tolerated by the body and do not lead to disease. The mutations reside primarily in non-coding regions of the genome not previously associated with disease, and include sites that are especially mutation-prone such as methylated cytosine DNA bases and solvent-accessible stretches of DNA.
By examining the fraction of the white blood cells containing the mutations we found that, at the time of her death, the majority of the peripheral blood was derived from only two active hematopoietic stem cells, in contrast to the 1,300 stem cells that are estimated to be simultaneously active in younger persons. Also, the distribution of the detected mutations indicated that one of these stem cells was derived from the other.
Because telomeres progressively shorten with each cell division, we also examined the length of the telomeres, The white blood cell telomeres were extremely short –17 times shorter than telomeres in the brain. Therefore, we speculate that most hematopoietic stem cells may have died from ‘stem cell exhaustion,’ reaching the upper limit of stem cell divisions. Whether stem cell exhaustion is likely to be a cause of death at extreme ages needs to be determined in future studies.
Somatic mutations found in the healthy blood compartment of a 115-year-old woman demonstrate oligoclonal hematopoiesis.
Holstege H, Pfeiffer W, Sie D, Hulsman M, Nicholas TJ, Lee CC, Ross T, Lin J, Miller MA, Ylstra B, Meijers-Heijboer H, Brugman MH, Staal FJT, Holstege G, Reinders MJT, Harkins TT, Levy S, Sistermans EA.
Genetic mutations are commonly studied because of links to diseases such as cancer; however, little is known about mutations occurring in healthy individuals. We used whole genome sequencing of the white blood cells from a 115-year-old woman to determine if, over a long lifetime, mutations accumulate in healthy white blood cells.
Our blood is continually replenished by hematopoietic stem cells that reside in the bone marrow and divide to generate different types of blood cells. Cell division, however, is error-prone, and cells that frequently divide, such as blood cells, are more likely to accumulate genetic mutations. Hundreds of mutations have been found in patients with blood cancers such as acute myeloid leukemia (AML), but it is unclear whether healthy white blood cells also harbor mutations.
We identified over 450 mutations in the healthy white blood cells of the 115 year old woman that were not found in her brain, a tissue which rarely undergoes cell division after birth. These mutations, known as somatic mutations because they are not passed on to offspring, appear to be tolerated by the body and do not lead to disease. The mutations reside primarily in non-coding regions of the genome not previously associated with disease, and include sites that are especially mutation-prone such as methylated cytosine DNA bases and solvent-accessible stretches of DNA.
By examining the fraction of the white blood cells containing the mutations we found that, at the time of her death, the majority of the peripheral blood was derived from only two active hematopoietic stem cells, in contrast to the 1,300 stem cells that are estimated to be simultaneously active in younger persons. Also, the distribution of the detected mutations indicated that one of these stem cells was derived from the other.
Because telomeres progressively shorten with each cell division, we also examined the length of the telomeres, The white blood cell telomeres were extremely short –17 times shorter than telomeres in the brain. Therefore, we speculate that most hematopoietic stem cells may have died from ‘stem cell exhaustion,’ reaching the upper limit of stem cell divisions. Whether stem cell exhaustion is likely to be a cause of death at extreme ages needs to be determined in future studies.
9
The extracellular metabolome of replicative- and irreparable DNA double strand break-induced senescence overlaps with the age-related metabolome of organs in vivo.
Emma L. James, Ryan D. Michalek¹, Gayani N. Pitiyage, Alice M. de Castro, Katie S. Vignola¹, Janice Jones¹, Robert P. Mohney¹, Edward D. Karoly¹, Stephen S. Prime and E. Kenneth Parkinson
Centre for Clinical & Diagnostic Oral Sciences, Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK.
1 Metabolon, Inc. 617 Davis Drive, Suite 400, Durham, NC 27713.
Cellular senescence modulates various pathologies and is associated with irreparable DNA double strand breaks (IrrDSBs). IrrDSBs are necessary for the secretion of a range of proteins, known as the senescence-associated secretory phenotype, which influences neighbouring cell behaviour. Senescence-associated extracellular metabolites, however, have not been characterised and they may potentially provide a non-invasive diagnostic tool as well as offering insight into metabolic changes in senescence. Extracellular metabolic profiles were generated from fibroblasts rendered senescent by proliferative exhaustion (PEsen) or 20 Gy of γ rays (IrrDSBsen) and compared with young proliferating cells, quiescent cells and cells exposed to repairable levels of DNA damage (0.5 Gy). The extracellular senescence metabolomes (ESMs) of IrrDSBsen showed increased levels of molecules involved in oxidative stress, nucleotide catabolism, branched-chain keto acid metabolism, transaminase reactions and sphingolipid metabolism, as well as reduced levels of nucleotides and dipeptides with similar changes detected in PEsen but at lower frequency. Characterisation of the ESM identified several candidate molecules for the non-invasive detection of human senescent cells in vivo with implications on the detection of a variety of human pathologies.
All the authors have read and approved the abstract and confirm they have no financial interests in the work.
The extracellular metabolome of replicative- and irreparable DNA double strand break-induced senescence overlaps with the age-related metabolome of organs in vivo.
Emma L. James, Ryan D. Michalek¹, Gayani N. Pitiyage, Alice M. de Castro, Katie S. Vignola¹, Janice Jones¹, Robert P. Mohney¹, Edward D. Karoly¹, Stephen S. Prime and E. Kenneth Parkinson
Centre for Clinical & Diagnostic Oral Sciences, Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK.
1 Metabolon, Inc. 617 Davis Drive, Suite 400, Durham, NC 27713.
Cellular senescence modulates various pathologies and is associated with irreparable DNA double strand breaks (IrrDSBs). IrrDSBs are necessary for the secretion of a range of proteins, known as the senescence-associated secretory phenotype, which influences neighbouring cell behaviour. Senescence-associated extracellular metabolites, however, have not been characterised and they may potentially provide a non-invasive diagnostic tool as well as offering insight into metabolic changes in senescence. Extracellular metabolic profiles were generated from fibroblasts rendered senescent by proliferative exhaustion (PEsen) or 20 Gy of γ rays (IrrDSBsen) and compared with young proliferating cells, quiescent cells and cells exposed to repairable levels of DNA damage (0.5 Gy). The extracellular senescence metabolomes (ESMs) of IrrDSBsen showed increased levels of molecules involved in oxidative stress, nucleotide catabolism, branched-chain keto acid metabolism, transaminase reactions and sphingolipid metabolism, as well as reduced levels of nucleotides and dipeptides with similar changes detected in PEsen but at lower frequency. Characterisation of the ESM identified several candidate molecules for the non-invasive detection of human senescent cells in vivo with implications on the detection of a variety of human pathologies.
All the authors have read and approved the abstract and confirm they have no financial interests in the work.
10
BRICHOS - a proprotein domain that prevents amyloid fibril toxicity
Jan Johansson, Jenny Presto, Erik Hermansson, Lisa Dolfe, Henrik Biverstål, Helen Poska
Centre for Alzheimer Research Centre, NVS Department, Karolinska Institutet, Novum, 5th floor, 141 57 Huddinge, Sweden
Amyloid fibrils are very stable β-sheet structures composed of one protein, unique for each amyloid disease. Although amyloid associated proteins are unique to each disease, the mechanism whereby they form amyloid is similar for all of them. Amyloid diseases encompass some of our time’s most devastating conditions, eg Alzheimer’s disease (AD) and type 2 diabetes, and no cures are available.
In vitro, amyloid fibrils can be formed from in principle any protein, but only thirty amyloid diseases have so far been described, ie only a minute fraction of all available proteins end up in amyloid. This suggests that many proteins are prevented from forming amyloid, because “nature” has evolved defence mechanism. We have found a specific domain – BRICHOS – that apparently guards extraordinarily amyloidogenic peptides.
We have used recombinant human BRICHOS, hippocampal slice preparations, Drosophila and cell culture systems, x-ray crystallography and physical-chemical methods to study the BRICHOS physiological function, effects on fibril formation and toxicity of amyloid forming peptides, general chaperone activity and structure-activity relationships.
BRICHOS from prosurfactant protein C prevents an extremely aggregation-prone transmembrane region from forming amyloid and mutations in this domain results in a novel amyloid disease. The BRICHOS domain, however, not only prevents amyloid formation of its natural client peptides but also of the amyloid β-peptide (Aβ) associated with AD, islet amyloid polypeptide (IAPP) associated with type 2 diabetes, medin associated with aortic amyloid and even designed β-model proteins. BRICHOS efficiently prevents neurotoxicity of Aβ in vivo and in mouse hippocampal slice preparations. BRICHOS counteracts toxicity by redirecting the fibrillation pathway so that generation of toxic oligomers is greatly reduced, a mechanism not described previously for any chaperone or aggregation inhibitor. Finally, BRICHOS from Bri2, associated with familial dementia and amyloid, possesses general chaperone activities and also reduces toxicity of Aβ in vivo.
Knight et al (2013). The BRICHOS domain, amyloid fibril formation, and their relationship. Biochemistry 52, 7523.
Hermansson et al (2014) The chaperone domain BRICHOS prevents CNS toxicity of amyloid-β peptide in Drosophila melanogaster. Dis. Mod. Mechan. 7,
Willander et al (2012). BRICHOS domains efficiently delay fibrillation of amyloid β-peptide. J. Biol. Chem. 287, 31608.
Willander et al (2012), High-resolution structure of a BRICHOS domain and its implications for anti-amyloid chaperone activity on lung surfactant protein C. Proc. Natl. Acad. Sci. USA, 109, 2325.
BRICHOS - a proprotein domain that prevents amyloid fibril toxicity
Jan Johansson, Jenny Presto, Erik Hermansson, Lisa Dolfe, Henrik Biverstål, Helen Poska
Centre for Alzheimer Research Centre, NVS Department, Karolinska Institutet, Novum, 5th floor, 141 57 Huddinge, Sweden
Amyloid fibrils are very stable β-sheet structures composed of one protein, unique for each amyloid disease. Although amyloid associated proteins are unique to each disease, the mechanism whereby they form amyloid is similar for all of them. Amyloid diseases encompass some of our time’s most devastating conditions, eg Alzheimer’s disease (AD) and type 2 diabetes, and no cures are available.
In vitro, amyloid fibrils can be formed from in principle any protein, but only thirty amyloid diseases have so far been described, ie only a minute fraction of all available proteins end up in amyloid. This suggests that many proteins are prevented from forming amyloid, because “nature” has evolved defence mechanism. We have found a specific domain – BRICHOS – that apparently guards extraordinarily amyloidogenic peptides.
We have used recombinant human BRICHOS, hippocampal slice preparations, Drosophila and cell culture systems, x-ray crystallography and physical-chemical methods to study the BRICHOS physiological function, effects on fibril formation and toxicity of amyloid forming peptides, general chaperone activity and structure-activity relationships.
BRICHOS from prosurfactant protein C prevents an extremely aggregation-prone transmembrane region from forming amyloid and mutations in this domain results in a novel amyloid disease. The BRICHOS domain, however, not only prevents amyloid formation of its natural client peptides but also of the amyloid β-peptide (Aβ) associated with AD, islet amyloid polypeptide (IAPP) associated with type 2 diabetes, medin associated with aortic amyloid and even designed β-model proteins. BRICHOS efficiently prevents neurotoxicity of Aβ in vivo and in mouse hippocampal slice preparations. BRICHOS counteracts toxicity by redirecting the fibrillation pathway so that generation of toxic oligomers is greatly reduced, a mechanism not described previously for any chaperone or aggregation inhibitor. Finally, BRICHOS from Bri2, associated with familial dementia and amyloid, possesses general chaperone activities and also reduces toxicity of Aβ in vivo.
Knight et al (2013). The BRICHOS domain, amyloid fibril formation, and their relationship. Biochemistry 52, 7523.
Hermansson et al (2014) The chaperone domain BRICHOS prevents CNS toxicity of amyloid-β peptide in Drosophila melanogaster. Dis. Mod. Mechan. 7,
Willander et al (2012). BRICHOS domains efficiently delay fibrillation of amyloid β-peptide. J. Biol. Chem. 287, 31608.
Willander et al (2012), High-resolution structure of a BRICHOS domain and its implications for anti-amyloid chaperone activity on lung surfactant protein C. Proc. Natl. Acad. Sci. USA, 109, 2325.
11
Prototype of crowdsourcing platform for aging research
Anton Kulaga
International Longevity Alliance (ILA)
Aging is very complex phenomena that requires integrating wide arrange of heterogeneous biomedical knowledge. A knowledge base together with powerful knowledge management and data mining tools may greatly improve research productivity of both aging researchers and research organization as a whole.
Currently biomedical knowledge is scattered in heterogeneous formats. It is present in the form of unstructured academic articles, semi-structured datasets, structured databases and non-accessible in the minds of experts. This renders this heterogeneous knowledge inaccessible for global computing.
With semantic web technologies and some crowdsourcing techniques it is possible to collect, integrate a large volume of such data and semi-automatically maintain its good quality.
There is a successful experience of establishing a database of longevity variants http://longevitydb.org/ that were collected entirely by volunteers mentored by several scientists. Even though in above mentioned project primitive instruments were used it became a good proof on concept.
Now a crowdsourcing platform for semantic annotations of aging research data is being developed. It will be integrated with SENS knowledgebase and will provide input user interface together with features to manage data collection process, data querying and task distributions to longevity community that will help researchers. Its working prototype will be demonstrated.
Prototype of crowdsourcing platform for aging research
Anton Kulaga
International Longevity Alliance (ILA)
Aging is very complex phenomena that requires integrating wide arrange of heterogeneous biomedical knowledge. A knowledge base together with powerful knowledge management and data mining tools may greatly improve research productivity of both aging researchers and research organization as a whole.
Currently biomedical knowledge is scattered in heterogeneous formats. It is present in the form of unstructured academic articles, semi-structured datasets, structured databases and non-accessible in the minds of experts. This renders this heterogeneous knowledge inaccessible for global computing.
With semantic web technologies and some crowdsourcing techniques it is possible to collect, integrate a large volume of such data and semi-automatically maintain its good quality.
There is a successful experience of establishing a database of longevity variants http://longevitydb.org/ that were collected entirely by volunteers mentored by several scientists. Even though in above mentioned project primitive instruments were used it became a good proof on concept.
Now a crowdsourcing platform for semantic annotations of aging research data is being developed. It will be integrated with SENS knowledgebase and will provide input user interface together with features to manage data collection process, data querying and task distributions to longevity community that will help researchers. Its working prototype will be demonstrated.
12
Sequencing the genome of the longest-lived mammal to identify longevity assurance mechanisms
Joao Pedro de Magalhaes
University of Liverpool, UK
The bowhead whale (Balaena mysticetus) is estimated to live over 200 years and is possibly the longest living mammal. These animals should possess protective molecular adaptations relevant to age-related diseases, particularly in the context of cancer as they can weigh over 100 tons. In this talk, I will discuss our recent work in sequencing and analyzing the genome of the bowhead whale to identify longevity assurance mechanisms. Our analysis identified several promising candidate genes in the bowhead with potential phenotypic effects, including in genes associated with DNA repair, cell cycle regulation, cancer and ageing. Our results open new perspectives concerning the evolution of mammalian longevity and provide insights regarding possible players involved in adaptive genetic changes conferring disease resistance. Overall, studying a species so long-lived and with such an extraordinary resistance to age-related diseases will help elucidate mechanisms and genes conferring longevity and disease resistance in mammals that in the future may be applied to improve human health.
Sequencing the genome of the longest-lived mammal to identify longevity assurance mechanisms
Joao Pedro de Magalhaes
University of Liverpool, UK
The bowhead whale (Balaena mysticetus) is estimated to live over 200 years and is possibly the longest living mammal. These animals should possess protective molecular adaptations relevant to age-related diseases, particularly in the context of cancer as they can weigh over 100 tons. In this talk, I will discuss our recent work in sequencing and analyzing the genome of the bowhead whale to identify longevity assurance mechanisms. Our analysis identified several promising candidate genes in the bowhead with potential phenotypic effects, including in genes associated with DNA repair, cell cycle regulation, cancer and ageing. Our results open new perspectives concerning the evolution of mammalian longevity and provide insights regarding possible players involved in adaptive genetic changes conferring disease resistance. Overall, studying a species so long-lived and with such an extraordinary resistance to age-related diseases will help elucidate mechanisms and genes conferring longevity and disease resistance in mammals that in the future may be applied to improve human health.
13
Is there a maximum lifespan for neurons?
Lorenzo Magrassi1, Ketty Leto2
1 Dipartimento di Scienze Clinico–Chirurgiche Diagnostiche e Pediatriche, University of Pavia Fondazione IRCCS Policlinico San Matteo and Istituto di Genetica Molecolare CNR, 27100 Pavia, Italy
2 Department of Neuroscience, Neuroscience Institute of Turin, University of Turin, 10043 Orbassano, Italy; and Neuroscience Institute of the Cavalieri Ottolenghi Foundation, University of Turin, 10125 Turin, Italy
Mature neurons in mammals are considered the paradigm of the post-mitotic cells. In absence of pathology the number of neurons in humans and mammals in general decrease less than 10% with aging. These results suggest that neurons, may survive at least as the entire lifetime of the individual, but they do not provide us with indications on the existence of a specific lifetime limit for neurons. Moreover, there are exceptions to the rule that aging is not accompanied by neuronal loss: in the mouse cerebellar cortex up to 40% of Purkinje neurons are lost during aging. Is neuronal lifespan limited to the individual lifespan or could be prolonged well beyond it. We answered to this question by exploiting the differences in maximum lifespan of different strains of mice and rats focusing on mouse Purkinje cell survival xenografted during fetal life into the developing rat cerebella. Our results indicate that, despite the species difference engrafted mouse neurons survive up to 36 months, the maximum lifespan of the host rats, doubling their average lifespan and lasting 38% longer than the maximum lifetime of the donor mice under our experimental conditions. Interestingly, the number of mouse Purkinje cells surviving after transplantation into the rat brain was not significantly different in host rats sacrificed within 18 months from the transplant and in older recipient animals, surviving up to 36 months. Cell death, however, is not the only effect of normal aging in Purkinje cells: Purkinje cells, as the majority of neurons in the brain, show a substantial loss of dendritic branches, spines and synapses. The results of our experiments indicate that the age related progressive spine loss occurs in grafted Purkinje cells and continues till death of the host individual. Rate of spine reduction, however, seems to follow a slower pace, typical of the longer living rat, thus reaching absolute levels of spine loss comparable to those observed in aged mice but after much longer survival times. Our results indicate that neuronal death and loss of spines are not cell autonomous. The great influence of the host environment demonstrated in our experiments suggests that both the genotype and the stochastic accumulation of damages (chronological aging) are not the principal determinants of neuronal aging and death.
Is there a maximum lifespan for neurons?
Lorenzo Magrassi1, Ketty Leto2
1 Dipartimento di Scienze Clinico–Chirurgiche Diagnostiche e Pediatriche, University of Pavia Fondazione IRCCS Policlinico San Matteo and Istituto di Genetica Molecolare CNR, 27100 Pavia, Italy
2 Department of Neuroscience, Neuroscience Institute of Turin, University of Turin, 10043 Orbassano, Italy; and Neuroscience Institute of the Cavalieri Ottolenghi Foundation, University of Turin, 10125 Turin, Italy
Mature neurons in mammals are considered the paradigm of the post-mitotic cells. In absence of pathology the number of neurons in humans and mammals in general decrease less than 10% with aging. These results suggest that neurons, may survive at least as the entire lifetime of the individual, but they do not provide us with indications on the existence of a specific lifetime limit for neurons. Moreover, there are exceptions to the rule that aging is not accompanied by neuronal loss: in the mouse cerebellar cortex up to 40% of Purkinje neurons are lost during aging. Is neuronal lifespan limited to the individual lifespan or could be prolonged well beyond it. We answered to this question by exploiting the differences in maximum lifespan of different strains of mice and rats focusing on mouse Purkinje cell survival xenografted during fetal life into the developing rat cerebella. Our results indicate that, despite the species difference engrafted mouse neurons survive up to 36 months, the maximum lifespan of the host rats, doubling their average lifespan and lasting 38% longer than the maximum lifetime of the donor mice under our experimental conditions. Interestingly, the number of mouse Purkinje cells surviving after transplantation into the rat brain was not significantly different in host rats sacrificed within 18 months from the transplant and in older recipient animals, surviving up to 36 months. Cell death, however, is not the only effect of normal aging in Purkinje cells: Purkinje cells, as the majority of neurons in the brain, show a substantial loss of dendritic branches, spines and synapses. The results of our experiments indicate that the age related progressive spine loss occurs in grafted Purkinje cells and continues till death of the host individual. Rate of spine reduction, however, seems to follow a slower pace, typical of the longer living rat, thus reaching absolute levels of spine loss comparable to those observed in aged mice but after much longer survival times. Our results indicate that neuronal death and loss of spines are not cell autonomous. The great influence of the host environment demonstrated in our experiments suggests that both the genotype and the stochastic accumulation of damages (chronological aging) are not the principal determinants of neuronal aging and death.
14
Exploring strategies for cell rejuvenation and tissues regeneration.
Milhavet O1,2, Lapasset L1, Schwerer H1, Aït-Hamou N1, Lemey C1, Innocenti C1, Desprat2, Becker F2, Pichard L2, Pellestor F1,3, Besnard E1, De Vos J1 and Jean-Marc Lemaitre1,2.
1 Laboratory of Genome and stem cell plasticity in development and aging, Institute of functional Genomics, 141 rue de la Cardonille, F-34094 Montpellier, Cedex 05, France
2Laboratory of Stem Cell reprogramming facility SAFE-iPSC, Institute of Regenerative Medicine and Biotherapies, St Eloi hospital, 80 rue Augustin Fliche, Montpellier, Cedex 05, France
3 Laboratory of Chromosomal Genetics ChromoStem Facility, Genetic department, Hôpital CHRU Arnaud de Villeneuve, 371 avenue du Doyen Gaston Giraud, 34295 Montpellier Cedex 5, France
Many of the pathologies that could benefit from regenerative stem cell-based therapies are associated to aging. Emmerging evidences indicates that adult stem cells exhibit functional shortcomings, including pronounced shifts in the types of mature effector cells produced as well as alterations in self-renewal capacity. Many intrinsic or extrinsic stress are able to accelerate the exhaustion of the proliferative capacity of stem cells or differentiated progenitors towards an ultimate senescence-like cell cycle arrest. Important and specific epigenetic modifications have been observed during this process, likely driving a specific gene expression « signature of cellular aging ». To further understand the impact of « epigenetics » in tissue aging and to unravel molecular barriers, preventing cell rejuvenation of the age-related cellular physiology, we developped, we developed reprogramming strategies of somatic cells into induced pluripotent stem cells (iPSCs) to erase the hallmarks of cellular aging. Although this strategy provides a unique opportunity to derive patient-specific stem cells with potential application in autologous tissue replacement, limitation was revealed for for elderly individuals, due to senescence described as a barrier to reprogramming. To overcome this barrier we developed an optimized six factor based-reprogramming strategy that caused efficient reversing of cellular senescence and aging through reprogramming into iPSCs. We demonstrated that iPSCs derived from senescent and centenarian fibroblasts have reset all the hallmarks of cellular aging, as telomere size, gene expression profiles, oxidative stress and mitochondrial metabolism, and are indistinguishable from hESC. Finally, we further demonstrate that re-differentiation, led to rejuvenated cells with a reset cellular physiology, defining a new paradigm for human cell rejuvenation. These results provide pave the way for regenerative medicine for aged patients in providing an unlimited source of various differentiated cell types for cell therapies and tissue regeneration.
Exploring strategies for cell rejuvenation and tissues regeneration.
Milhavet O1,2, Lapasset L1, Schwerer H1, Aït-Hamou N1, Lemey C1, Innocenti C1, Desprat2, Becker F2, Pichard L2, Pellestor F1,3, Besnard E1, De Vos J1 and Jean-Marc Lemaitre1,2.
1 Laboratory of Genome and stem cell plasticity in development and aging, Institute of functional Genomics, 141 rue de la Cardonille, F-34094 Montpellier, Cedex 05, France
2Laboratory of Stem Cell reprogramming facility SAFE-iPSC, Institute of Regenerative Medicine and Biotherapies, St Eloi hospital, 80 rue Augustin Fliche, Montpellier, Cedex 05, France
3 Laboratory of Chromosomal Genetics ChromoStem Facility, Genetic department, Hôpital CHRU Arnaud de Villeneuve, 371 avenue du Doyen Gaston Giraud, 34295 Montpellier Cedex 5, France
Many of the pathologies that could benefit from regenerative stem cell-based therapies are associated to aging. Emmerging evidences indicates that adult stem cells exhibit functional shortcomings, including pronounced shifts in the types of mature effector cells produced as well as alterations in self-renewal capacity. Many intrinsic or extrinsic stress are able to accelerate the exhaustion of the proliferative capacity of stem cells or differentiated progenitors towards an ultimate senescence-like cell cycle arrest. Important and specific epigenetic modifications have been observed during this process, likely driving a specific gene expression « signature of cellular aging ». To further understand the impact of « epigenetics » in tissue aging and to unravel molecular barriers, preventing cell rejuvenation of the age-related cellular physiology, we developped, we developed reprogramming strategies of somatic cells into induced pluripotent stem cells (iPSCs) to erase the hallmarks of cellular aging. Although this strategy provides a unique opportunity to derive patient-specific stem cells with potential application in autologous tissue replacement, limitation was revealed for for elderly individuals, due to senescence described as a barrier to reprogramming. To overcome this barrier we developed an optimized six factor based-reprogramming strategy that caused efficient reversing of cellular senescence and aging through reprogramming into iPSCs. We demonstrated that iPSCs derived from senescent and centenarian fibroblasts have reset all the hallmarks of cellular aging, as telomere size, gene expression profiles, oxidative stress and mitochondrial metabolism, and are indistinguishable from hESC. Finally, we further demonstrate that re-differentiation, led to rejuvenated cells with a reset cellular physiology, defining a new paradigm for human cell rejuvenation. These results provide pave the way for regenerative medicine for aged patients in providing an unlimited source of various differentiated cell types for cell therapies and tissue regeneration.
15
Cellular senescence in tissue remodeling: from physiology to pathology.
Daniel Muñoz
Recent discoveries are re-defining our view of cellular senescence as a trigger of tissue remodeling that acts during normal embryonic development and upon tissue damage. In the case of developmental processes, cellular senescence facilitates the elimination of transient structures, controls the balance of different cell populations, and contributes to the regulation of morphogenesis. To achieve tissue renewal, senescent cells arrest their own proliferation, recruit phagocytic immune cells, and promote the mobilization of nearby progenitor cells that repopulate the tissue. This sequence of events (senescence, followed by clearance and then regeneration) may not be efficiently completed in aged or pathological contexts, thereby resulting in the accumulation of senescent cells that aggravates tissue dysfunction. Increasing evidence indicates that manipulation of cellular senescence can be used as an innovative therapeutic tool. In cancer and during active tissue repair, pro-senescent therapies contribute to minimize the damage by limiting proliferation and fibrosis, respectively. At the same time, anti-senescent therapies may help to eliminate senescent areas that accumulate during ageing or chronic damage and recover tissue function.
Cellular senescence in tissue remodeling: from physiology to pathology.
Daniel Muñoz
Recent discoveries are re-defining our view of cellular senescence as a trigger of tissue remodeling that acts during normal embryonic development and upon tissue damage. In the case of developmental processes, cellular senescence facilitates the elimination of transient structures, controls the balance of different cell populations, and contributes to the regulation of morphogenesis. To achieve tissue renewal, senescent cells arrest their own proliferation, recruit phagocytic immune cells, and promote the mobilization of nearby progenitor cells that repopulate the tissue. This sequence of events (senescence, followed by clearance and then regeneration) may not be efficiently completed in aged or pathological contexts, thereby resulting in the accumulation of senescent cells that aggravates tissue dysfunction. Increasing evidence indicates that manipulation of cellular senescence can be used as an innovative therapeutic tool. In cancer and during active tissue repair, pro-senescent therapies contribute to minimize the damage by limiting proliferation and fibrosis, respectively. At the same time, anti-senescent therapies may help to eliminate senescent areas that accumulate during ageing or chronic damage and recover tissue function.
16
Immunity and ageing: causes and effects of immunosenescence in humans
Graham Pawelec
University of Tübingen, Germany
[email protected]
The immune system defends against infection, but older people paradoxically suffer both from failing immunity resulting in increased susceptibility to infections and decreased responsiveness to vaccination, but at the same time increased immunopathology and inflammation accompanying immune responses. Interventions to reduce such deleterious effects while enhancing protective immunity are challenging but need to be confronted if we are to deal successfully with the increasing numbers of elderly and frail people in modern societies. To do this, we need to understand the mechanisms responsible for age-associated increased susceptibility to infections and immune-influenced chronic degenerative diseases of ageing. Defining relevant age-associated alterations and identifying reliable biomarkers for monitoring clinically-relevant immune status in the elderly is crucial to overcoming these problems. This means performing longitudinal as well as cross-sectional studies assessing innate and adaptive immune parameters, the impact of the individual genetic background, and epigenetic modifications dependent on environmental exposures, and then correlating these factors with morbidity and mortality at follow-up over the years. Limited longitudinal studies have begun to reveal biomarkers of immune ageing increasingly recognized as an “immune risk profile” (IRP) predicting mortality in the very elderly. Hallmark parameters of the IRP may also be associated with poorer responses to vaccination. Initially surprisingly, but now widely accepted, usually asymptomatic infection with the widespread persistent beta-herpesvirus HHV5 (Cytomegalovirus, CMV) has an enormous impact on these immune biomarkers. This is probably because, for reasons not fully understood, a large proportion of available human immune resources is committed to controlling CMV, but not other persistent herpesviruses, in infected individuals. The prevalence of CMV infection in populations in industrialized countries increases with age, and within individuals, the degree of immune commitment also increases with age. This may cause pathology by maintaining higher systemic levels of inflammatory mediators and decreasing the “immunological space” available for immune cells with other specificities. Interventions to prevent or reverse immunosenescence may therefore need to include targeting infectious agents such as CMV.
Immunity and ageing: causes and effects of immunosenescence in humans
Graham Pawelec
University of Tübingen, Germany
[email protected]
The immune system defends against infection, but older people paradoxically suffer both from failing immunity resulting in increased susceptibility to infections and decreased responsiveness to vaccination, but at the same time increased immunopathology and inflammation accompanying immune responses. Interventions to reduce such deleterious effects while enhancing protective immunity are challenging but need to be confronted if we are to deal successfully with the increasing numbers of elderly and frail people in modern societies. To do this, we need to understand the mechanisms responsible for age-associated increased susceptibility to infections and immune-influenced chronic degenerative diseases of ageing. Defining relevant age-associated alterations and identifying reliable biomarkers for monitoring clinically-relevant immune status in the elderly is crucial to overcoming these problems. This means performing longitudinal as well as cross-sectional studies assessing innate and adaptive immune parameters, the impact of the individual genetic background, and epigenetic modifications dependent on environmental exposures, and then correlating these factors with morbidity and mortality at follow-up over the years. Limited longitudinal studies have begun to reveal biomarkers of immune ageing increasingly recognized as an “immune risk profile” (IRP) predicting mortality in the very elderly. Hallmark parameters of the IRP may also be associated with poorer responses to vaccination. Initially surprisingly, but now widely accepted, usually asymptomatic infection with the widespread persistent beta-herpesvirus HHV5 (Cytomegalovirus, CMV) has an enormous impact on these immune biomarkers. This is probably because, for reasons not fully understood, a large proportion of available human immune resources is committed to controlling CMV, but not other persistent herpesviruses, in infected individuals. The prevalence of CMV infection in populations in industrialized countries increases with age, and within individuals, the degree of immune commitment also increases with age. This may cause pathology by maintaining higher systemic levels of inflammatory mediators and decreasing the “immunological space” available for immune cells with other specificities. Interventions to prevent or reverse immunosenescence may therefore need to include targeting infectious agents such as CMV.
17
The role of aging in transthyretin amyloidosis (ATTR)
V. Planté-Bordeneuve, MD, PhD.
Department of Neurology- Amyloid Network – CHU Henri Mondor – Créteil - France
Transthyretin (TTR) amyloidosis includes systemic degenerative disorders characterized by fibrillar amyloid deposition of TTR as main protein precursor. TTR which is mainly synthetized in the liver has a tetrameric structure. Aging was recently stressed to play an important role on the disease expression. The condition was originally described in Portuguese kindreds, as a severe axonal neuropathy with onset in young adult. This form was dominantly inherited and linked to one variation of the gene, namely the TTR-
Val30Met in all families. Subsequently, similar condition was identified in kindreds across the world, with more than 100 different pathogenic missense mutation of the gene now reported. In parallel, the phenotypic spectrum was refined including a wide range of age at first symptoms, up to the ninth decade and apparently sporadic cases. Also, the clinical presentation often combines a progressive sensori-motor and autonomic neuropathy, a carpal tunnel syndrome (CTS) and a restrictive hypertrophic cardiopathy that manifests later in life. In older patients, the cardiomyopathy is prominent or even isolated. Renal manifestations or ophthalmologic involvement are less frequent. In contrast, central nervous expression of the disease is very uncommon due to leptomeningeal TTR amyloid deposits. On the other hand, an entity called senile systemic amyloidosis (SSA) is characterized by wild type TTR deposition. SSA is prevalent in elderly and manifests with a severe hypertrophic cardiomyopathy, almost exclusively in male patients. Here, amyloid deposition affects mainly the heart, but also tenosynovial tissues with CTS, tendons and ligaments with lumbar canal stenosis. Such condition is clearly an age related process and a continuum with the clinical picture of mutated TTR diseases seems to exist. The presentation will cover the main presentation and diagnostic issues of TTR related disorders and recent therapeutic advances in the field.
The role of aging in transthyretin amyloidosis (ATTR)
V. Planté-Bordeneuve, MD, PhD.
Department of Neurology- Amyloid Network – CHU Henri Mondor – Créteil - France
Transthyretin (TTR) amyloidosis includes systemic degenerative disorders characterized by fibrillar amyloid deposition of TTR as main protein precursor. TTR which is mainly synthetized in the liver has a tetrameric structure. Aging was recently stressed to play an important role on the disease expression. The condition was originally described in Portuguese kindreds, as a severe axonal neuropathy with onset in young adult. This form was dominantly inherited and linked to one variation of the gene, namely the TTR-
Val30Met in all families. Subsequently, similar condition was identified in kindreds across the world, with more than 100 different pathogenic missense mutation of the gene now reported. In parallel, the phenotypic spectrum was refined including a wide range of age at first symptoms, up to the ninth decade and apparently sporadic cases. Also, the clinical presentation often combines a progressive sensori-motor and autonomic neuropathy, a carpal tunnel syndrome (CTS) and a restrictive hypertrophic cardiopathy that manifests later in life. In older patients, the cardiomyopathy is prominent or even isolated. Renal manifestations or ophthalmologic involvement are less frequent. In contrast, central nervous expression of the disease is very uncommon due to leptomeningeal TTR amyloid deposits. On the other hand, an entity called senile systemic amyloidosis (SSA) is characterized by wild type TTR deposition. SSA is prevalent in elderly and manifests with a severe hypertrophic cardiomyopathy, almost exclusively in male patients. Here, amyloid deposition affects mainly the heart, but also tenosynovial tissues with CTS, tendons and ligaments with lumbar canal stenosis. Such condition is clearly an age related process and a continuum with the clinical picture of mutated TTR diseases seems to exist. The presentation will cover the main presentation and diagnostic issues of TTR related disorders and recent therapeutic advances in the field.
18
Microglia in Healthy Ageing; harnessing their good intentions.
Jennifer M Pocock, Department of Neuroinflammation, University College London, Institute of Neurology, 1 Wakefield Street, London WC1N 1PJ
[email protected]
Microglia, the resident immune cell of the brain, mediate CNS innate immune responses and carry out numerous functions to ensure the brain remains healthy. With ageing, microglia can become senescent, stressed and dystrophic, resulting in a reduction in trophic functions of these cells. In addition, pathways which were previously silent in microglia, can become activated. The loss of trophic support by microglia may have ramifications for the integrity of synapses and neural networks in the brain. With ageing, neuronal changes occur within the brain such as synapse loss and altered neurotransmitter release, leading to altered synaptic homeostasis and resulting in the development of deficits in spatial learning and memory.
The transcription factor, p53, modulates microglial responses and can be activated by the presence of amyloid peptides, chromogranin peptides, reactive oxygen species or following stimulation of toll-like receptor 4, all of which may occur progressively with ageing and neurodegeneration. Activation of p53 in microglia can switch the phenotype of these cells from an anti-inflammatory function which promotes recovery and repair, to one which is pro-inflammatory and may be detrimental to neurons. Here we will discuss how activation of p53 in microglia is detrimental because of a direct effect on synapse function and loss, and how amelioration of the pathways responsible can promote a healthy protective phenotype in microglia.
Microglia in Healthy Ageing; harnessing their good intentions.
Jennifer M Pocock, Department of Neuroinflammation, University College London, Institute of Neurology, 1 Wakefield Street, London WC1N 1PJ
[email protected]
Microglia, the resident immune cell of the brain, mediate CNS innate immune responses and carry out numerous functions to ensure the brain remains healthy. With ageing, microglia can become senescent, stressed and dystrophic, resulting in a reduction in trophic functions of these cells. In addition, pathways which were previously silent in microglia, can become activated. The loss of trophic support by microglia may have ramifications for the integrity of synapses and neural networks in the brain. With ageing, neuronal changes occur within the brain such as synapse loss and altered neurotransmitter release, leading to altered synaptic homeostasis and resulting in the development of deficits in spatial learning and memory.
The transcription factor, p53, modulates microglial responses and can be activated by the presence of amyloid peptides, chromogranin peptides, reactive oxygen species or following stimulation of toll-like receptor 4, all of which may occur progressively with ageing and neurodegeneration. Activation of p53 in microglia can switch the phenotype of these cells from an anti-inflammatory function which promotes recovery and repair, to one which is pro-inflammatory and may be detrimental to neurons. Here we will discuss how activation of p53 in microglia is detrimental because of a direct effect on synapse function and loss, and how amelioration of the pathways responsible can promote a healthy protective phenotype in microglia.
19
Healthy ageing, hormesis and future lines of investigation
Suresh I.S. Rattan
Laboratory of Cellular Ageing, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark (email: [email protected])
There are no gerontogenes with the specific function of causing ageing. Genes determine the ability to live and maintain health for essential lifespan (ELS). A longer life beyond ELS allows the emergence of ageing with its physical, mental and social manifestations. The very act of living causes damage in our cells. A network of molecular, cellular and physiological maintenance and repair systems creates a “homeodynamic space”, or a “buffering capacity” against such damages. Ageing is the progressive shrinkage of the homeodynamic space, reduced stress tolerance and increased vulnerability. A promising scientific approach towards healthy ageing is that of hormesis for maintaining health and homeodynamics. Hormesis is the positive relationship between mild stress and health. Conditions that induce hormesis are called hormetins, and are categorised as nutritional, physical and mental hormetins. Two challenging questions that need to be given high priority in biological ageing research are: (1) what is the functional relevance of various types of molecular damage that accumulate during ageing? and (2) what are the biological determinants of health and homeodynamic space in terms of stress response profiles, damage control and tolerance, and adaptive abilities? Resolving these issues are crucial with respect to testing, developing and applying effective means of ageing interventions for maintaining health and activity in old age.
Healthy ageing, hormesis and future lines of investigation
Suresh I.S. Rattan
Laboratory of Cellular Ageing, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark (email: [email protected])
There are no gerontogenes with the specific function of causing ageing. Genes determine the ability to live and maintain health for essential lifespan (ELS). A longer life beyond ELS allows the emergence of ageing with its physical, mental and social manifestations. The very act of living causes damage in our cells. A network of molecular, cellular and physiological maintenance and repair systems creates a “homeodynamic space”, or a “buffering capacity” against such damages. Ageing is the progressive shrinkage of the homeodynamic space, reduced stress tolerance and increased vulnerability. A promising scientific approach towards healthy ageing is that of hormesis for maintaining health and homeodynamics. Hormesis is the positive relationship between mild stress and health. Conditions that induce hormesis are called hormetins, and are categorised as nutritional, physical and mental hormetins. Two challenging questions that need to be given high priority in biological ageing research are: (1) what is the functional relevance of various types of molecular damage that accumulate during ageing? and (2) what are the biological determinants of health and homeodynamic space in terms of stress response profiles, damage control and tolerance, and adaptive abilities? Resolving these issues are crucial with respect to testing, developing and applying effective means of ageing interventions for maintaining health and activity in old age.
20
Longevity and Aging, role of genes and extracellular matrix (ECM).
L. Robert and J. Labat-Robert
Hotel Dieu Hospital, Univ Paris 5
Email : [email protected]
Longevity is different for every animal species as well as their genome, suggesting a correlation between genes and life-span. Estimates put the genetic effect from 5 to 35 % approximately, suggesting that even genetic effects are dependent on environmental conditions. This contention is largely confirmed by the study of identical twins raised apart [1]. They do not die at the same age and also for different reasons. Aging is not « genetically » programmed, it is outside evolutionary constraint. Evolution favors early and efficient reproduction, but does not care for longevity. A number of mechanisms were shown to be involved in the age-dependent decline of vital functions, among them the Maillard reaction (non enzymatic glycosylation)[2] and the age-dependent upregulation of proteolytic activity [3]. Aging of ECM is a complex process comprising progressive modification of its macromolecular components and of cell-matrix interactions. An important process is the uncoupling of the elastin receptor from its « young » transmission pathway losing all physiological effects, but enhancing free radical and elastase release. These processes contribute to age-related ECM degradation, production of matrikines aggravating functional loss with age. Both genetic and post-genetic mechanisms are susceptible to be influenced by medical, pharmacological and dietary interventions. Among the genetic mechanisms, those attributed to the Sirtuins, (7 orthologs identified in the human genome) are especially important. Among the environmental effects, nutrition, hygiene and weather conditions play a role. These data justify some predictions on the evolution of life expectancy taking in account also socio-economic factors. Biological constraints become evident by the comparison of centenarians and supercentenarians (less than 1% of centenarians) putting an upper limit to the attainable human lifespan.
1. Segal NL. Born together – reared apart. Harvard Univ Press, Cambridge, Mass, 2012
2. Robert L, Robert AM, Labat-Robert J. The Maillard reaction – illicite (bio) chemistry in tissues and food. Pathol Biol 2011 ; 59 : 321-328
3. Robert L, Labat-Robert J, Hornebeck W. Aging and Atherosclerosis. In Atherosclerosis Reviews. Gotto AM and Paoletti R Eds. Vol 14, pp 143-170, Raven Press , New York, 1986
Longevity and Aging, role of genes and extracellular matrix (ECM).
L. Robert and J. Labat-Robert
Hotel Dieu Hospital, Univ Paris 5
Email : [email protected]
Longevity is different for every animal species as well as their genome, suggesting a correlation between genes and life-span. Estimates put the genetic effect from 5 to 35 % approximately, suggesting that even genetic effects are dependent on environmental conditions. This contention is largely confirmed by the study of identical twins raised apart [1]. They do not die at the same age and also for different reasons. Aging is not « genetically » programmed, it is outside evolutionary constraint. Evolution favors early and efficient reproduction, but does not care for longevity. A number of mechanisms were shown to be involved in the age-dependent decline of vital functions, among them the Maillard reaction (non enzymatic glycosylation)[2] and the age-dependent upregulation of proteolytic activity [3]. Aging of ECM is a complex process comprising progressive modification of its macromolecular components and of cell-matrix interactions. An important process is the uncoupling of the elastin receptor from its « young » transmission pathway losing all physiological effects, but enhancing free radical and elastase release. These processes contribute to age-related ECM degradation, production of matrikines aggravating functional loss with age. Both genetic and post-genetic mechanisms are susceptible to be influenced by medical, pharmacological and dietary interventions. Among the genetic mechanisms, those attributed to the Sirtuins, (7 orthologs identified in the human genome) are especially important. Among the environmental effects, nutrition, hygiene and weather conditions play a role. These data justify some predictions on the evolution of life expectancy taking in account also socio-economic factors. Biological constraints become evident by the comparison of centenarians and supercentenarians (less than 1% of centenarians) putting an upper limit to the attainable human lifespan.
1. Segal NL. Born together – reared apart. Harvard Univ Press, Cambridge, Mass, 2012
2. Robert L, Robert AM, Labat-Robert J. The Maillard reaction – illicite (bio) chemistry in tissues and food. Pathol Biol 2011 ; 59 : 321-328
3. Robert L, Labat-Robert J, Hornebeck W. Aging and Atherosclerosis. In Atherosclerosis Reviews. Gotto AM and Paoletti R Eds. Vol 14, pp 143-170, Raven Press , New York, 1986
21
Protein glycation: between tissue aging and protection against lung tumor formation
Andreas Simm
Protein glycation is a major mechanism of ageing. AGEs can harm tissue by 1) changing protein function due to the modification, 2) change protein turnover, 3) crosslinking proteins leading to tissue stiffening, 4) inducing radical formation and 5) induction of an inflammatory responses after binding to specific AGE receptors. The plasma fluorescence related to the standard fluorescence of advanced glycation end products (AGEs) is a simple measurable blood parameter related to diseases like Diabetes but its importance in human cancer, including non-small cell lung carcinoma (NSCLC), is unknown. Plasma samples of NSCLC patients who underwent resection surgery were analyzed for AGE-related plasma fluorescence and the prognostic relevance of this fluorescence was tested. NSCLC patients with high (> median) AGE-related plasma fluorescence were characterized by a later reoccurrence of the tumor after curative surgery and a higher survival rate compared with patients with low plasma fluorescence (25% versus 47% 5-y survival, P = 0.011). Treating NSCLC cell spheroids with patients’ plasma showed an inverse correlation between the growth of spheroids in vitro and the individual AGE-related fluorescence of each plasma sample. To confirm the impact of circulating AGEs on the NSCLC progression, we studied the NSCLC growth in mice whose circulating AGE level was elevated by AGE-rich diet. These experiments demonstrated that mice with higher levels of circulating AGEs developed smaller tumors than mice with normal AGE levels. The AGE-related plasma fluorescence has prognostic relevance for NSCLC patients in whom the tumor growth-inhibiting effect of circulating AGEs might play a critical role. Our data show, that beside the well-known pathophysiological effects of AGEs, these molecules may have a benefit in the context of lung tumor formation.
Protein glycation: between tissue aging and protection against lung tumor formation
Andreas Simm
Protein glycation is a major mechanism of ageing. AGEs can harm tissue by 1) changing protein function due to the modification, 2) change protein turnover, 3) crosslinking proteins leading to tissue stiffening, 4) inducing radical formation and 5) induction of an inflammatory responses after binding to specific AGE receptors. The plasma fluorescence related to the standard fluorescence of advanced glycation end products (AGEs) is a simple measurable blood parameter related to diseases like Diabetes but its importance in human cancer, including non-small cell lung carcinoma (NSCLC), is unknown. Plasma samples of NSCLC patients who underwent resection surgery were analyzed for AGE-related plasma fluorescence and the prognostic relevance of this fluorescence was tested. NSCLC patients with high (> median) AGE-related plasma fluorescence were characterized by a later reoccurrence of the tumor after curative surgery and a higher survival rate compared with patients with low plasma fluorescence (25% versus 47% 5-y survival, P = 0.011). Treating NSCLC cell spheroids with patients’ plasma showed an inverse correlation between the growth of spheroids in vitro and the individual AGE-related fluorescence of each plasma sample. To confirm the impact of circulating AGEs on the NSCLC progression, we studied the NSCLC growth in mice whose circulating AGE level was elevated by AGE-rich diet. These experiments demonstrated that mice with higher levels of circulating AGEs developed smaller tumors than mice with normal AGE levels. The AGE-related plasma fluorescence has prognostic relevance for NSCLC patients in whom the tumor growth-inhibiting effect of circulating AGEs might play a critical role. Our data show, that beside the well-known pathophysiological effects of AGEs, these molecules may have a benefit in the context of lung tumor formation.
22
Metformin and healthy aging: mitohormesis is good for you.
Liesbet Temmerman, Wouter De Haes
This work was a collaborative effort between the department of Animal Physiology at the University of Leuven (KU Leuven, Belgium) and the lab of Aging Physiology and Molecular Evolution at Ghent University (UGent, Belgium). Thanks to all partners for their relentless enthusiasm in looking for/at healthily aging worms, always wondering how it might work.
Recently it has been shown that metformin, currently the most powerful anti-diabetic drug, might possess general health-promoting properties, but exactly how this drug is able to exert its beneficial effects remains largely unexplored. It is assumed that elucidating metformin’s mode of action will vastly increase its application range, and will contribute to healthy aging.
Via an integrative approach using proteomic, bioinformatic, biochemical and phenotypic techniques and the model organism Caenorhabditis elegans, we gained molecular understanding of the physiological changes elicited by metformin exposure, including changes in branched-chain amino acid catabolism and cuticle maintenance.
We could show that metformin extends lifespan through the process of mitohormesis and propose a signaling cascade in which metformin-induced production of reactive oxygen species (ROS) eventually increases overall life expectancy. This adds to the growing body of evidence that within the context of a mild stress response, ROS signaling is beneficial for an organism.
We further address an important issue in aging research, where so far, the key factor that executes the essential task of translating the ROS signal into a pro-longevity cue remained elusive. We were able to pinpoint a molecule that is able to perform this task, an exciting finding because it fills in a major missing link in the field. We dissected how this beneficial signal of the mitohormetic pathway is propagated and propose that the mechanism, which will be presented in detail, might underlie a general principle of pro-longevity signaling.
The overall knowledge of the action of metformin in living organisms is of direct interest to millions of people worldwide. Our work provides detailed insights into the beneficial effects and evolutionary conserved pathways employed by metformin, and fills in missing links in aging research. Continued research efforts in this field could lead towards targeted improvement of aging-related complications.
Metformin and healthy aging: mitohormesis is good for you.
Liesbet Temmerman, Wouter De Haes
This work was a collaborative effort between the department of Animal Physiology at the University of Leuven (KU Leuven, Belgium) and the lab of Aging Physiology and Molecular Evolution at Ghent University (UGent, Belgium). Thanks to all partners for their relentless enthusiasm in looking for/at healthily aging worms, always wondering how it might work.
Recently it has been shown that metformin, currently the most powerful anti-diabetic drug, might possess general health-promoting properties, but exactly how this drug is able to exert its beneficial effects remains largely unexplored. It is assumed that elucidating metformin’s mode of action will vastly increase its application range, and will contribute to healthy aging.
Via an integrative approach using proteomic, bioinformatic, biochemical and phenotypic techniques and the model organism Caenorhabditis elegans, we gained molecular understanding of the physiological changes elicited by metformin exposure, including changes in branched-chain amino acid catabolism and cuticle maintenance.
We could show that metformin extends lifespan through the process of mitohormesis and propose a signaling cascade in which metformin-induced production of reactive oxygen species (ROS) eventually increases overall life expectancy. This adds to the growing body of evidence that within the context of a mild stress response, ROS signaling is beneficial for an organism.
We further address an important issue in aging research, where so far, the key factor that executes the essential task of translating the ROS signal into a pro-longevity cue remained elusive. We were able to pinpoint a molecule that is able to perform this task, an exciting finding because it fills in a major missing link in the field. We dissected how this beneficial signal of the mitohormetic pathway is propagated and propose that the mechanism, which will be presented in detail, might underlie a general principle of pro-longevity signaling.
The overall knowledge of the action of metformin in living organisms is of direct interest to millions of people worldwide. Our work provides detailed insights into the beneficial effects and evolutionary conserved pathways employed by metformin, and fills in missing links in aging research. Continued research efforts in this field could lead towards targeted improvement of aging-related complications.
23
Omic markers of aging using twin studies
Ana M Valdes, MA PhD
Associate Professor and Reader, School of Medicine University of Nottingham
Senior lecturer, School of Medicine, King’s College London
Aging has been described as a progressive decline in the ability to withstand stress, damage and disease and age is also a major risk factor in the development of many diseases. Age related changes do not occur at the same rate among individuals. Some of the variation in the rate of aging between individuals is under genetic control, the majority of interindividual variation (>70%) is not inherited. This implies the existence of molecular changes over time which must relate to environmental, epigenetic and lifestyle factors. Lifestyle factors such smoking and nutrition intake contribute to aging. At the same time, it has been shown that early development (i.e. malnutrition during gestation) contributes to health or disease in old age and this can be traced to epigenetic changes in the DNA As high throughput omics technologies (genomics, metabolomics, metagenomics and transcriptomics) become available studies are unravelling the molecular changes associated with aging and the biological pathways underlying this complex multifactorial process. Data on some of the molecular changes associated with aging as reflected by metabolomic and proteomic analyses in the TwinsUK cohort discovered as part of the EurHEALTHAging project will be presented. The specific role and pathways involved in early development and age related changes, with particular emphasis on blood pressure and response to antihypertensive therapy is also discussed.
Supported by the EU FP7 project EurHEALTHAging.
Omic markers of aging using twin studies
Ana M Valdes, MA PhD
Associate Professor and Reader, School of Medicine University of Nottingham
Senior lecturer, School of Medicine, King’s College London
Aging has been described as a progressive decline in the ability to withstand stress, damage and disease and age is also a major risk factor in the development of many diseases. Age related changes do not occur at the same rate among individuals. Some of the variation in the rate of aging between individuals is under genetic control, the majority of interindividual variation (>70%) is not inherited. This implies the existence of molecular changes over time which must relate to environmental, epigenetic and lifestyle factors. Lifestyle factors such smoking and nutrition intake contribute to aging. At the same time, it has been shown that early development (i.e. malnutrition during gestation) contributes to health or disease in old age and this can be traced to epigenetic changes in the DNA As high throughput omics technologies (genomics, metabolomics, metagenomics and transcriptomics) become available studies are unravelling the molecular changes associated with aging and the biological pathways underlying this complex multifactorial process. Data on some of the molecular changes associated with aging as reflected by metabolomic and proteomic analyses in the TwinsUK cohort discovered as part of the EurHEALTHAging project will be presented. The specific role and pathways involved in early development and age related changes, with particular emphasis on blood pressure and response to antihypertensive therapy is also discussed.
Supported by the EU FP7 project EurHEALTHAging.
24
The effect of aging on neuroregenerative capacities: insights from the senescent zebrafish
J. Van houcke*, K. Lemmens, I. Bollaerts, I. Van Hove and L. Moons
Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium
[email protected]
Since adult mammals lack the capacity to regenerate lost or damaged neurons, age-related deterioration of the central nervous system (CNS) seriously constrains life quality of a growing number of elderly. Despite intensive research, induction of neuronal and axonal regeneration and subsequent functional recovery of the diseased mammalian CNS remains a challenge, especially in an aging environment. In contrast to mammals, zebrafish have a high neurogenic and regenerative capacity. However, they also age gradually and thus form an ideal model to study the effects of aging on regeneration.
We focus on the zebrafish retinotectal system, a powerful system to study neurogenesis, neuronal survival and axonal regrowth after damage. Detailed morphometric and immunohistochemical analyses of the aged zebrafish retina confirmed the occurrence of age-related retinal atrophy and revealed a clear manifestation of inflammaging. These hallmarks of aging are accompanied by a reduction in the endogenous neurogenic capacity of the ciliary marginal zone and, more importantly, by a significant delay in axonal regeneration after optic nerve crush, resulting in a diminished reinnervation of the tectum in 2-year-old zebrafish.
A detailed characterization of the aged zebrafish retinotectal system and its regeneration potential, will allow us to elucidate underlying mechanisms and pathways, and might unveil new targets for the development of novel regenerative strategies in the senescent mammalian CNS.
The effect of aging on neuroregenerative capacities: insights from the senescent zebrafish
J. Van houcke*, K. Lemmens, I. Bollaerts, I. Van Hove and L. Moons
Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium
[email protected]
Since adult mammals lack the capacity to regenerate lost or damaged neurons, age-related deterioration of the central nervous system (CNS) seriously constrains life quality of a growing number of elderly. Despite intensive research, induction of neuronal and axonal regeneration and subsequent functional recovery of the diseased mammalian CNS remains a challenge, especially in an aging environment. In contrast to mammals, zebrafish have a high neurogenic and regenerative capacity. However, they also age gradually and thus form an ideal model to study the effects of aging on regeneration.
We focus on the zebrafish retinotectal system, a powerful system to study neurogenesis, neuronal survival and axonal regrowth after damage. Detailed morphometric and immunohistochemical analyses of the aged zebrafish retina confirmed the occurrence of age-related retinal atrophy and revealed a clear manifestation of inflammaging. These hallmarks of aging are accompanied by a reduction in the endogenous neurogenic capacity of the ciliary marginal zone and, more importantly, by a significant delay in axonal regeneration after optic nerve crush, resulting in a diminished reinnervation of the tectum in 2-year-old zebrafish.
A detailed characterization of the aged zebrafish retinotectal system and its regeneration potential, will allow us to elucidate underlying mechanisms and pathways, and might unveil new targets for the development of novel regenerative strategies in the senescent mammalian CNS.
25
DNA Methylation Changes in Replicative Senescence and Aging
Wolfgang Wagner*
Helmholtz-Institute for Biomedical Engineering; Stem Cell Biology and Cellular Engineering; RWTH Aachen University Medical School, Aachen, Germany
Replicative senescence during in vitro culture of primary cells and aging of the organism appear to be two related processes. Both are associated with highly reproducible DNA methylation (DNAm) changes at specific sites in the genome – yet, there are significant differences in DNAm patterns of long-term culture and aging. So far, there is little evidence how DNAm is regulated at specific sites in the genome and whether these modifications are cause or consequence of the aging process. I will demonstrate that specific epigenetic modifications are reliable biomarkers: senescence-associated DNAm changes can be used to track the number of population doublings for quality control of cell preparations (Koch et al., Aging Cell. 2012 and Genome Res. 2013); age-related DNAm changes facilitate predictions of donor age (Weidner et al., Genome Biol. 2014). These epigenetic age-predictions are affected by disease and life-style parameters and may therefore rather reflect biological age than chronological age. Notably, senescence-associated as well as age-associated DNAm changes are reversed in induced pluripotent stem cells (iPSCs) and this may play a central role for their escape from both – replicative senescence and aging.
Conflicts of Interest:
RWTH Aachen University Medical School has applied for patent applications for an Epigenetic- Senescence-Signature and an Epigenetic-Aging-Signature. Wolfgang Wagner is involved in the company Cygenia which provides service for these methods to other researchers (www.cygenia.com).
DNA Methylation Changes in Replicative Senescence and Aging
Wolfgang Wagner*
Helmholtz-Institute for Biomedical Engineering; Stem Cell Biology and Cellular Engineering; RWTH Aachen University Medical School, Aachen, Germany
Replicative senescence during in vitro culture of primary cells and aging of the organism appear to be two related processes. Both are associated with highly reproducible DNA methylation (DNAm) changes at specific sites in the genome – yet, there are significant differences in DNAm patterns of long-term culture and aging. So far, there is little evidence how DNAm is regulated at specific sites in the genome and whether these modifications are cause or consequence of the aging process. I will demonstrate that specific epigenetic modifications are reliable biomarkers: senescence-associated DNAm changes can be used to track the number of population doublings for quality control of cell preparations (Koch et al., Aging Cell. 2012 and Genome Res. 2013); age-related DNAm changes facilitate predictions of donor age (Weidner et al., Genome Biol. 2014). These epigenetic age-predictions are affected by disease and life-style parameters and may therefore rather reflect biological age than chronological age. Notably, senescence-associated as well as age-associated DNAm changes are reversed in induced pluripotent stem cells (iPSCs) and this may play a central role for their escape from both – replicative senescence and aging.
Conflicts of Interest:
RWTH Aachen University Medical School has applied for patent applications for an Epigenetic- Senescence-Signature and an Epigenetic-Aging-Signature. Wolfgang Wagner is involved in the company Cygenia which provides service for these methods to other researchers (www.cygenia.com).
26
In silico screening for drugs and drug combinations for aging and age-related diseases.
Zhavoronkov AA
Tissue-specific signaling pathway activation strength (SPAS) profiles generated using the OncoFinder algorithm were shown to be better biomarkers of cancer than individual genes (1,2) and can be used to compare gene expression data obtained on various microarray and NGS platforms (3). We proposed using SPAS for comparing gene expression between different cellular states including young and old tissue-specific samples and predicting the geroprotective properties of drugs with known molecular targets or effects on gene expression (4) and developed a platform called GeroScope for drug discovery. Here we will discuss the possible approaches to finding geroprotector combinations so that maximize the geroprotective effects and minimize toxicity and adverse effects.
1. Buzdin AA, Zhavoronkov AA, Korzinkin MB, Venkova LS, Zenin AA, Smirnov PY and Borisov NM (2014) Oncofinder, a new method for the analysis of intracellular signaling pathway activation using transcriptomic data. Front. Genet. 5:55. doi: 10.3389/fgene.2014.00055
2. Nikolay M. Borisov, Nadezhda V. Terekhanova, Alexander M. Aliper, Larisa S. Venkova, Philip Yu. Smirnov, Sergey Roumiantsev, Mikhail B. Korzinkin, Alex A. Zhavoronkov, Anton A. Buzdin (2014), “Signaling pathway activation profiles make better markers of cancer than expression of individual genes”, Oncotarget, accepted, in print
3. Buzdin AA, Zhavoronkov AA, Korzinkin MB, Roumiantsev SA, Aliper AM, Venkova LS, Smirnov PY and Borisov NM (2014) The OncoFinder algorithm for minimizing the errors introduced by the high-throughput methods of transcriptome analysis. Front. Mol. Biosci. 1:8. doi: 10.3389/fmolb.2014.00008
4. Zhavoronkov A, Buzdin AA, Garazha AV, Borissov NM and Moskalev AA (2014) Signaling pathway cloud regulation for in silico screening and ranking of the potential geroprotective drugs. Front. Genet. 5:49. doi: 10.3389/fgene.2014.00049
In silico screening for drugs and drug combinations for aging and age-related diseases.
Zhavoronkov AA
Tissue-specific signaling pathway activation strength (SPAS) profiles generated using the OncoFinder algorithm were shown to be better biomarkers of cancer than individual genes (1,2) and can be used to compare gene expression data obtained on various microarray and NGS platforms (3). We proposed using SPAS for comparing gene expression between different cellular states including young and old tissue-specific samples and predicting the geroprotective properties of drugs with known molecular targets or effects on gene expression (4) and developed a platform called GeroScope for drug discovery. Here we will discuss the possible approaches to finding geroprotector combinations so that maximize the geroprotective effects and minimize toxicity and adverse effects.
1. Buzdin AA, Zhavoronkov AA, Korzinkin MB, Venkova LS, Zenin AA, Smirnov PY and Borisov NM (2014) Oncofinder, a new method for the analysis of intracellular signaling pathway activation using transcriptomic data. Front. Genet. 5:55. doi: 10.3389/fgene.2014.00055
2. Nikolay M. Borisov, Nadezhda V. Terekhanova, Alexander M. Aliper, Larisa S. Venkova, Philip Yu. Smirnov, Sergey Roumiantsev, Mikhail B. Korzinkin, Alex A. Zhavoronkov, Anton A. Buzdin (2014), “Signaling pathway activation profiles make better markers of cancer than expression of individual genes”, Oncotarget, accepted, in print
3. Buzdin AA, Zhavoronkov AA, Korzinkin MB, Roumiantsev SA, Aliper AM, Venkova LS, Smirnov PY and Borisov NM (2014) The OncoFinder algorithm for minimizing the errors introduced by the high-throughput methods of transcriptome analysis. Front. Mol. Biosci. 1:8. doi: 10.3389/fmolb.2014.00008
4. Zhavoronkov A, Buzdin AA, Garazha AV, Borissov NM and Moskalev AA (2014) Signaling pathway cloud regulation for in silico screening and ranking of the potential geroprotective drugs. Front. Genet. 5:49. doi: 10.3389/fgene.2014.00049
