scholarly journals Epigenetic clock and methylation studies in the rhesus macaque

GeroScience ◽  
2021 ◽  
Author(s):  
Steve Horvath ◽  
Joseph A. Zoller ◽  
Amin Haghani ◽  
Anna J. Jasinska ◽  
Ken Raj ◽  
...  

AbstractMethylation levels at specific CpG positions in the genome have been used to develop accurate estimators of chronological age in humans, mice, and other species. Although epigenetic clocks are generally species-specific, the principles underpinning them appear to be conserved at least across the mammalian class. This is exemplified by the successful development of epigenetic clocks for mice and several other mammalian species. Here, we describe epigenetic clocks for the rhesus macaque (Macaca mulatta), the most widely used nonhuman primate in biological research. Using a custom methylation array (HorvathMammalMethylChip40), we profiled n = 281 tissue samples (blood, skin, adipose, kidney, liver, lung, muscle, and cerebral cortex). From these data, we generated five epigenetic clocks for macaques. These clocks differ with regard to applicability to different tissue types (pan-tissue, blood, skin), species (macaque only or both humans and macaques), and measure of age (chronological age versus relative age). Additionally, the age-based human-macaque clock exhibits a high age correlation (R = 0.89) with the vervet monkey (Chlorocebus sabaeus), another Old World species. Four CpGs within the KLF14 promoter were consistently altered with age in four tissues (adipose, blood, cerebral cortex, skin). Future studies will be needed to evaluate whether these epigenetic clocks predict age-related conditions in the rhesus macaque.

Author(s):  
Steve Horvath ◽  
Joseph A. Zoller ◽  
Amin Haghani ◽  
Anna J. Jasinska ◽  
Ken Raj ◽  
...  

ABSTRACTMethylation levels at specific CpG positions in the genome have been used to develop accurate estimators of chronological age in humans, mice, and other species. Although epigenetic clocks are generally species-specific, the principles underpinning them appear to be conserved at least across the mammalian class. This is exemplified by the successful development of epigenetic clocks for mice and several other mammalian species. Here, we describe epigenetic clocks for the rhesus macaque (Macaca mulatta), the most widely used nonhuman primate in biological research. Using a custom methylation array (HorvathMammalMethylChip40), we profiled n=281 tissue samples (blood, skin, adipose, kidney, liver, lung, muscle, and cerebral cortex). From these data, we generated five epigenetic clocks for macaques. These clocks differ with regards to applicability to different tissue types (pan-tissue, blood, skin), species (macaque only or both humans and macaques), and measure of age (chronological age versus relative age). Additionally, the age-based human-macaque clock exhibits a high age correlation (R=0.89) with the vervet monkey (Chlorocebus sabaeus), another Old World species. Four CpGs within the KLF14 promoter were consistently altered with age in four tissues (adipose, blood, cerebral cortex, skin). It is expected that the macaque clocks will reveal an epigenetic aging rate associated with a host of health conditions and thus lend themselves for identifying and validating anti-aging interventions.


2020 ◽  
Author(s):  
Steve Horvath ◽  
Amin Haghani ◽  
Joseph A. Zoller ◽  
Jason Ernst ◽  
Matteo Pellegrini ◽  
...  

ABSTRACTDNA methylation data have been successfully used to develop highly accurate estimators of age (“epigenetic clocks”) in several mammalian species. With a view of extending epigenetic clocks to primates, we analyzed DNA methylation profiles from five primate species; Papio hamadryas (baboons), Callithrix jacchus (common marmoset), Chlorocebus sabaeus (vervet monkey), Macaca mulatta (rhesus macaque), and Homo sapiens (human). From these we present here, a highly accurate primate epigenetic clock. This clock is based on methylation profiles of CpGs that are highly conserved and are located on a custom methylation array (HorvathMammalMethylChip40). Furthermore, we carried out in-depth analysis of the baboon, as it is evolutionarily the closest primate to humans that can be employed in biomedical research. We present five epigenetic clocks for baboons (Olive-yellow baboon hybrid), one of which, the pan tissue epigenetic clock, was trained on seven tissue types (fetal cerebral cortex, adult cerebral cortex, cerebellum, adipose, heart, liver, and skeletal muscle) with ages ranging from late fetal life to 22.8 years of age. To facilitate translational capability, we constructed two dual-species, human-baboon clocks, whereby one measures ages of both species in units of years, while the other reports ages relative to the maximum lifespan of the species. Although the primate clock applies to all five primate species, the baboon-specific clocks exhibit only moderate age correlations with other primates. We also provide detailed gene and pathway analyses of individual CpGs that relate to age and sex across different primate species. Ten out of 739 sex related CpGs in primate species are located near 9 autosomal genes (including FAM217A, CDYL, POU3F2, and UHRF2). Overall, this study sheds light on epigenetic aging mechanisms in primates, and the potential influence of sex.


2020 ◽  
Author(s):  
Jean-François Lemaître ◽  
Benjamin Rey ◽  
Jean-Michel Gaillard ◽  
Corinne Régis ◽  
Emmanuelle Gilot ◽  
...  

AbstractDNA methylation-based biomarkers of aging (epigenetic clocks) promise to lead to new insights in the evolutionary biology of ageing. Relatively little is known about how the natural environment affects epigenetic aging effects in wild species. In this study, we took advantage of a unique long-term (>40 years) longitudinal monitoring of individual roe deer (Capreolus capreolus) living in two wild populations (Chizé and Trois Fontaines, France) facing different ecological contexts to investigate the relationship between chronological age and levels of DNA methylation (DNAm). We generated novel DNA methylation data from n=90 blood samples using a custom methylation array (HorvathMammalMethylChip40). We present three DNA methylation-based estimators of age (DNAm or epigenetic age), which were trained in males, females, and both sexes combined. We investigated how sex differences influenced the relationship between DNAm age and chronological age through the use of sex-specific epigenetic clocks. Our results highlight that both populations and sex influence the epigenetic age, with the bias toward a stronger male average age acceleration (i.e. differences between epigenetic age and chronological ages) particularly pronounced in the population facing harsh environmental conditions. Further, we identify the main sites of epigenetic alteration that have distinct aging patterns across the two sexes. These findings open the door to promising avenues of research at the crossroad of evolutionary biology and biogerontology.


Author(s):  
Pavanello ◽  
Campisi ◽  
Tona ◽  
Lin ◽  
Iliceto

DNA methylation (DNAm) is an emerging estimator of biological aging, i.e., the often-defined “epigenetic clock”, with a unique accuracy for chronological age estimation (DNAmAge). In this pilot longitudinal study, we examine the hypothesis that intensive relaxing training of 60 days in patients after myocardial infarction and in healthy subjects may influence leucocyte DNAmAge by turning back the epigenetic clock. Moreover, we compare DNAmAge with another mechanism of biological age, leucocyte telomere length (LTL) and telomerase. DNAmAge is reduced after training in healthy subjects (p = 0.053), but not in patients. LTL is preserved after intervention in healthy subjects, while it continues to decrease in patients (p = 0.051). The conventional negative correlation between LTL and chronological age becomes positive after training in both patients (p < 0.01) and healthy subjects (p < 0.05). In our subjects, DNAmAge is not associated with LTL. Our findings would suggest that intensive relaxing practices influence different aging molecular mechanisms, i.e., DNAmAge and LTL, with a rejuvenating effect. Our study reveals that DNAmAge may represent an accurate tool to measure the effectiveness of lifestyle-based interventions in the prevention of age-related diseases.


2020 ◽  
Vol 35 (6) ◽  
pp. 1332-1345
Author(s):  
K W Olsen ◽  
J Castillo-Fernandez ◽  
A Zedeler ◽  
N C Freiesleben ◽  
M Bungum ◽  
...  

Abstract STUDY QUESTION Does women’s age affect the DNA methylation (DNAm) profile differently in mural granulosa cells (MGCs) from other somatic cells? SUMMARY ANSWER Accumulation of epimutations by age and a higher number of age-related differentially methylated regions (DMR) in MGCs were found compared to leukocytes from the same woman, suggesting that the MGCs have a distinctive epigenetic profile. WHAT IS KNOWN ALREADY The mechanisms underlying the decline in women’s fertility from the mid-30s remain to be fully elucidated. The DNAm age of many healthy tissues changes predictably with and follows chronological age, but DNAm age in some reproductive tissues has been shown to depart from chronological age (older: endometrium; younger: cumulus cells, spermatozoa). STUDY DESIGN, SIZE, DURATION This study is a multicenter cohort study based on retrospective analysis of prospectively collected data and material derived from healthy women undergoing IVF or ICSI treatment following ovarian stimulation with antagonist protocol. One hundred and nineteen women were included from September 2016 to June 2018 from four clinics in Denmark and Sweden. PARTICIPANTS/MATERIALS, SETTING, METHODS Blood samples were obtained from 118 healthy women with varying ovarian reserve status. MGCs were collected from 63 of the 119 women by isolation from pooled follicles immediately after oocyte retrieval. DNA from leukocytes and MGCs was extracted and analysed with a genome-wide methylation array. Data from the methylation array were processed using the ENmix package. Subsequently, DNAm age was calculated using established and tailored age predictors and DMRs were analysed with the DMRcate package. MAIN RESULTS AND ROLE OF CHANCE Using established age predictors, DNAm age in MGCs was found to be considerable younger and constant (average: 2.7 years) compared to chronological age (average: 33.9 years). A Granulosa Cell clock able to predict the age of both MGCs (average: 32.4 years) and leukocytes (average: 38.8 years) was successfully developed. MGCs differed from leukocytes in having a higher number of epimutations (P = 0.003) but predicted telomere lengths unaffected by age (Pearson’s correlation coefficient = −0.1, P = 0.47). DMRs associated with age (age-DMRs) were identified in MGCs (n = 335) and in leukocytes (n = 1) with a significant enrichment in MGCs for genes involved in RNA processing (45 genes, P = 3.96 × 10−08) and gene expression (152 genes, P = 2.3 × 10−06). The top age-DMRs included the metastable epiallele VTRNA2-1, the DNAm regulator ZFP57 and the anti-Müllerian hormone (AMH) gene. The apparent discordance between different epigenetic measures of age in MGCs suggests that they reflect difference stages in the MGC life cycle. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION No gene expression data were available to associate with the epigenetic findings. The MGCs are collected during ovarian stimulation, which may influence DNAm; however, no correlation between FSH dose and number of epimutations was found. WIDER IMPLICATIONS OF THE FINDINGS Our findings underline that the somatic compartment of the follicle follows a different methylation trajectory with age than other somatic cells. The higher number of epimutations and age-DMRs in MGCs suggest that their function is affected by age. STUDY FUNDING/COMPETING INTEREST(S) This project is part of ReproUnion collaborative study, co-financed by the European Union, Interreg V ÖKS, the Danish National Research Foundation and the European Research Council. The authors declare no conflict of interest.


2020 ◽  
Author(s):  
Leonard C Steg ◽  
Gemma L Shireby ◽  
Jennifer Imm ◽  
Jonathan P Davies ◽  
Robert Flynn ◽  
...  

Abstract Induced pluripotent stem cells (iPSCs) and their differentiated neurons (iPSC-neurons) are a widely used cellular model in the research of the central nervous system. However, it is unknown how well they capture age-associated processes, particularly given that pluripotent cells are only present during the early stages of mammalian development. Epigenetic clocks utilize coordinated age-associated changes in DNA methylation to make predictions that correlate strongly with chronological age, and is has been shown that the induction of pluripotency rejuvenates predicted epigenetic age. As existing clocks are not optimized for the study of brain development, to investigate more precisely the epigenetic age of iPSCs and iPSC-neurons, here, we establish the fetal brain clock (FBC), a bespoke epigenetic clock trained in prenatal neurodevelopmental samples. Our data show that the FBC outperforms other established epigenetic clocks in predicting the age of fetal brain samples. We then applied the FBC to DNA methylation data of cellular datasets that have profiled iPSCs and iPSC-derived neuronal precursor cells and neurons and find that these cell types are characterized by a fetal epigenetic age. Furthermore, while differentiation from iPSCs to neurons significantly increases the epigenetic age, iPSC-neurons are still predicted as having fetal epigenetic age. Together our findings reiterate the need for better understanding of the limitations of existing epigenetic clocks for answering biological research questions and highlight a potential limitation of iPSC-neurons as a cellular model for the research of age-related diseases as they might not fully recapitulate an aged phenotype.


2020 ◽  
Author(s):  
Leonard C. Steg ◽  
Gemma L. Shireby ◽  
Jennifer Imm ◽  
Jonathan P. Davies ◽  
Robert Flynn ◽  
...  

AbstractInduced pluripotent stem cells (iPSCs) and their differentiated neurons (iPSC-neurons) are a widely used cellular model in the research of the central nervous system. However, it is unknown how well they capture age-associated processes, particularly given that pluripotent cells are only present during the early stages of mammalian development. Epigenetic clocks utilize coordinated age-associated changes in DNA methylation to make predictions that correlate strongly with chronological age, and is has been shown that the induction of pluripotency rejuvenates predicted epigenetic age. As existing clocks are not optimized for the study of brain development, to investigate more precisely the epigenetic age of iPSCs and iPSC-neurons, here, we establish the fetal brain clock (FBC), a bespoke epigenetic clock trained in prenatal neurodevelopmental samples. Our data show that the FBC outperforms other established epigenetic clocks in predicting the age of fetal brain samples. We then applied the FBC to DNA methylation data of cellular datasets that have profiled iPSCs and iPSC-derived neuronal precursor cells and neurons and find that these cell types are characterized by a fetal epigenetic age. Furthermore, while differentiation from iPSCs to neurons significantly increases the epigenetic age, iPSC-neurons are still predicted as having fetal epigenetic age. Together our findings reiterate the need for better understanding of the limitations of existing epigenetic clocks for answering biological research questions and highlight a potential limitation of iPSC-neurons as a cellular model for the research of age-related diseases as they might not fully recapitulate an aged phenotype.


2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Thomas H. Jonkman ◽  
Koen F. Dekkers ◽  
Roderick C. Slieker ◽  
Crystal D. Grant ◽  
M. Arfan Ikram ◽  
...  

Abstract Background Epigenetic clocks use DNA methylation (DNAm) levels of specific sets of CpG dinucleotides to accurately predict individual chronological age. A popular application of these clocks is to explore whether the deviation of predicted age from chronological age is associated with disease phenotypes, where this deviation is interpreted as a potential biomarker of biological age. This wide application, however, contrasts with the limited insight in the processes that may drive the running of epigenetic clocks. Results We perform a functional genomics analysis on four epigenetic clocks, including Hannum’s blood predictor and Horvath’s multi-tissue predictor, using blood DNA methylome and transcriptome data from 3132 individuals. The four clocks result in similar predictions of individual chronological age, and their constituting CpGs are correlated in DNAm level and are enriched for similar histone modifications and chromatin states. Interestingly, DNAm levels of CpGs from the clocks are commonly associated with gene expression in trans. The gene sets involved are highly overlapping and enriched for T cell processes. Further analysis of the transcriptome and methylome of sorted blood cell types identifies differences in DNAm between naive and activated T and NK cells as a probable contributor to the clocks. Indeed, within the same donor, the four epigenetic clocks predict naive cells to be up to 40 years younger than activated cells. Conclusions The ability of epigenetic clocks to predict chronological age involves their ability to detect changes in proportions of naive and activated immune blood cells, an established feature of immuno-senescence. This finding may contribute to the interpretation of associations between clock-derived measures and age-related health outcomes.


2020 ◽  
Author(s):  
Natalia A. Prado ◽  
Janine L. Brown ◽  
Joseph A. Zoller ◽  
Amin Haghani ◽  
Mingjia Yao ◽  
...  

ABSTRACTAge-associated DNA-methylation profiles have been used successfully to develop highly accurate biomarkers of age (“epigenetic clocks”) in humans, mice, dogs, and other species. Here we present epigenetic clocks for African and Asian elephants. These clocks were developed using novel DNA methylation profiles of 140 elephant blood samples of known age, at loci that are highly conserved between mammalian species, using a custom Infinium array (HorvathMammalMethylChip40). We present epigenetic clocks for Asian elephants (Elephas maximus), African elephants (Loxodonta africana), and both elephant species combined. Two additional human-elephant clocks were constructed by combing human and elephant samples. Epigenome-wide association studies identified elephant age-related CpGs and their proximal genes. The products of these genes play important roles in cellular differentiation, organismal development, metabolism, and circadian rhythms. Intracellular events observed to change with age included the methylation of bivalent chromatin domains, targets of polycomb repressive complexes, and TFAP2C binding sites. These readily available epigenetic clocks can be used for elephant conservation efforts where accurate estimates of age are needed to predict demographic trends.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Victoria J Sugrue ◽  
Joseph Alan Zoller ◽  
Pritika Narayan ◽  
Ake T Lu ◽  
Oscar J Ortega-Recalde ◽  
...  

In mammals, females generally live longer than males. Nevertheless, the mechanisms underpinning sex-dependent longevity are currently unclear. Epigenetic clocks are powerful biological biomarkers capable of precisely estimating chronological age and identifying novel factors influencing the aging rate using only DNA methylation data. In this study, we developed the first epigenetic clock for domesticated sheep (Ovis aries), which can predict chronological age with a median absolute error of 5.1 months. We have discovered that castrated male sheep have a decelerated aging rate compared to intact males, mediated at least in part by the removal of androgens. Furthermore, we identified several androgen-sensitive CpG dinucleotides that become progressively hypomethylated with age in intact males, but remain stable in castrated males and females. Comparable sex-specific methylation differences in MKLN1 also exist in bat skin and a range of mouse tissues that have high androgen receptor expression, indicating it may drive androgen-dependent hypomethylation in divergent mammalian species. In characterising these sites, we identify biologically plausible mechanisms explaining how androgens drive male-accelerated aging.


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