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Neal SJ, Whitney S, Yi SV, Simmons JH. Epigenetic and accelerated age in captive olive baboons ( Papio anubis), and relationships with walking speed and fine motor performance. Aging (Albany NY) 2025; 17:740-756. [PMID: 40105865 PMCID: PMC11984432 DOI: 10.18632/aging.206223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 03/06/2025] [Indexed: 03/20/2025]
Abstract
Epigenetic age, estimated by DNA methylation across the genome, reflects biological age. Accelerated age (i.e., an older methylation age than expected given chronological age) is an accepted aging biomarker in humans, showing robust associations with deleterious health outcomes, longevity, and mortality. However, data regarding age acceleration in nonhuman primates (NHPs), and relationships between NHP epigenetic age and behavioral indicators of aging, such as walking speed and fine motor performance, are sparse. We measured DNA methylation of 140 captive olive baboons (Papio anubis) (84% female, 3-20 years-old), estimated their epigenetic ages, and classified them as showing age acceleration or deceleration. We found that epigenetic age was strongly correlated with chronological age, and that approximately 27% of the sample showed age acceleration and 28% showed age deceleration. We subsequently examined relationships between epigenetic and accelerated age and walking speed (N=129) and fine motor performance (N=39). Older animals showed slower speeds and poorer motor performance. However, the difference between the epigenetic age and chronological age, referred to as delta age, was not a consistent predictor of walking speed or fine motor performance. These data highlight the need for further examination of age acceleration across NHP species, and the ways that age acceleration may (not) be related to indicators of aging in NHP models.
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Affiliation(s)
- Sarah J Neal
- The University of Texas MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, National Center for Chimpanzee Care, TX 78602, USA
| | - Shannon Whitney
- Texas State University, Department of Biology Supple Science Building, TX 78666, USA
| | - Soojin V Yi
- Department of Ecology and Evolution and Marine Biology, Department of Molecular, Cellular and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Joe H Simmons
- The University of Texas MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, National Center for Chimpanzee Care, TX 78602, USA
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Mariencheck CL. The immunity gap in primates. Evol Anthropol 2024; 33:e22038. [PMID: 38877873 DOI: 10.1002/evan.22038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 08/09/2024]
Abstract
Vertebrates exhibit sexual dimorphism in response to infectious diseases and in morbidity and mortality rates to various pathogens. Females are generally more immunocompetent than males, despite their increased reproductive burden and the immunosuppressive effects of gestation. In addition, females generally have lower incidences of cancer compared to males; however, they have higher rates of autoimmune disorders. These sex differences may be a result of life history differences, sexual selection, genetics, and/or the physiological effects of hormones. As highly social mammals with complex life histories, primates offer a unique opportunity to investigate the evolution of enhanced female immunocompetence. This review aims to examine the evidence of this immunity gap, understand current hypotheses for its evolution, and explore the potential role of X chromosome specific genes and heterozygosity within this framework.
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Affiliation(s)
- Clara L Mariencheck
- Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, Washington, District of Columbia, USA
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Neal SJ, Achorn AM, Schapiro SJ, Hopkins WD, Simmons JH. Neutrophil to lymphocyte ratio in captive olive baboons (Papio anubis): The effects of age, sex, rearing, stress, and pregnancy. Am J Primatol 2024; 86:e23619. [PMID: 38482892 PMCID: PMC11090752 DOI: 10.1002/ajp.23619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 02/21/2024] [Accepted: 03/02/2024] [Indexed: 05/14/2024]
Abstract
In apes and humans, neutrophil to lymphocyte ratio (NLR) can be used as a predictive indicator of a variety of clinical conditions, longevity, and physiological stress. In chimpanzees specifically, NLR systematically varies with age, rearing, sex, and premature death, indicating that NLR may be a useful diagnostic tool in assessing primate health. To date, just one very recent study has investigated NLR in old world monkeys and found lower NLR in males and nursery-reared individuals, as well as a negative relationship between NLR and disease outcomes. Given that baboons are increasingly used as research models, we aimed to characterize NLR in baboons by providing descriptive data and examinations of baboon NLR heritability, and of the relationships between NLR, age, rearing, and sex in 387 olive baboons (Papio anubis) between 6 months and 19 years of age. We found that (1) mother-reared baboons had higher NLRs than nursery-reared baboons; (2) females had higher NLRs than males; and (3) there was a quadratic relationship between NLR and age, such that middle-aged individuals had the highest NLR values. We also examined NLR as a function of transport to a new facility using a subset of the data. Baboons exhibited significantly higher transport NLRs compared to routine exam NLRs. More specifically, adult baboons had higher transport NLRs than routine NLRs, whereas juveniles showed no such difference, suggesting that younger animals may experience transport stress differently than older animals. We also found that transport NLR was heritable, whereas routine NLR was not, possibly suggesting that stress responses (as indicated in NLR) have a strong genetic component. Consistent with research in humans and chimpanzees, these findings suggest that NLR varies with important biological and life history variables and that NLR may be a useful health biomarker in baboons.
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Affiliation(s)
- Sarah J. Neal
- The University of Texas MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, 650 Cool Water Drive, Bastrop, Texas, 78602
| | - Angela M. Achorn
- The University of Texas MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, 650 Cool Water Drive, Bastrop, Texas, 78602
| | - Steven J. Schapiro
- The University of Texas MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, 650 Cool Water Drive, Bastrop, Texas, 78602
- The University of Copenhagen, Department of Experimental Medicine, Copenhagen, Denmark
| | - William D. Hopkins
- The University of Texas MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, 650 Cool Water Drive, Bastrop, Texas, 78602
| | - Joe H. Simmons
- The University of Texas MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, 650 Cool Water Drive, Bastrop, Texas, 78602
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Le Clercq LS, Kotzé A, Grobler JP, Dalton DL. Biological clocks as age estimation markers in animals: a systematic review and meta-analysis. Biol Rev Camb Philos Soc 2023; 98:1972-2011. [PMID: 37356823 DOI: 10.1111/brv.12992] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 06/04/2023] [Accepted: 06/08/2023] [Indexed: 06/27/2023]
Abstract
Various biological attributes associated with individual fitness in animals change predictably over the lifespan of an organism. Therefore, the study of animal ecology and the work of conservationists frequently relies upon the ability to assign animals to functionally relevant age classes to model population fitness. Several approaches have been applied to determining individual age and, while these methods have proved useful, they are not without limitations and often lack standardisation or are only applicable to specific species. For these reasons, scientists have explored the potential use of biological clocks towards creating a universal age-determination method. Two biological clocks, tooth layer annulation and otolith layering have found universal appeal. Both methods are highly invasive and most appropriate for post-mortem age-at-death estimation. More recently, attributes of cellular ageing previously explored in humans have been adapted to studying ageing in animals for the use of less-invasive molecular methods for determining age. Here, we review two such methods, assessment of methylation and telomere length, describing (i) what they are, (ii) how they change with age, and providing (iii) a summary and meta-analysis of studies that have explored their utility in animal age determination. We found that both attributes have been studied across multiple vertebrate classes, however, telomere studies were used before methylation studies and telomere length has been modelled in nearly twice as many studies. Telomere length studies included in the review often related changes to stress responses and illustrated that telomere length is sensitive to environmental and social stressors and, in the absence of repair mechanisms such as telomerase or alternative lengthening modes, lacks the ability to recover. Methylation studies, however, while also detecting sensitivity to stressors and toxins, illustrated the ability to recover from such stresses after a period of accelerated ageing, likely due to constitutive expression or reactivation of repair enzymes such as DNA methyl transferases. We also found that both studied attributes have parentally heritable features, but the mode of inheritance differs among taxa and may relate to heterogamy. Our meta-analysis included more than 40 species in common for methylation and telomere length, although both analyses included at least 60 age-estimation models. We found that methylation outperforms telomere length in terms of predictive power evidenced from effect sizes (more than double that observed for telomeres) and smaller prediction intervals. Both methods produced age correlation models using similar sample sizes and were able to classify individuals into young, middle, or old age classes with high accuracy. Our review and meta-analysis illustrate that both methods are well suited to studying age in animals and do not suffer significantly from variation due to differences in the lifespan of the species, genome size, karyotype, or tissue type but rather that quantitative method, patterns of inheritance, and environmental factors should be the main considerations. Thus, provided that complex factors affecting the measured trait can be accounted for, both methylation and telomere length are promising targets to develop as biomarkers for age determination in animals.
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Affiliation(s)
- Louis-Stéphane Le Clercq
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Antoinette Kotzé
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - J Paul Grobler
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Desiré Lee Dalton
- School of Health and Life Sciences, Teesside University, Middlesbrough, TS1 3BA, UK
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Schröder S, Heck J, Groh A, Frieling H, Bleich S, Kahl KG, Bosch JJ, Krichevsky B, Schulze-Westhoff M. White Blood Cell and Platelet Counts Are Not Suitable as Biomarkers in the Differential Diagnostics of Dementia. Brain Sci 2022; 12:1424. [PMID: 36358351 PMCID: PMC9688654 DOI: 10.3390/brainsci12111424] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/06/2022] [Accepted: 10/21/2022] [Indexed: 03/04/2025] Open
Abstract
Apart from Alzheimer's disease (AD), no biomarkers for the differential diagnosis of dementia have been established to date. Inflammatory processes contribute to the pathogenesis of dementia subtypes, e.g., AD or frontotemporal dementia (FTD). In the context of cancer or cardiovascular diseases, white blood cell (WBC) populations and platelet counts, as well as C-reactive protein (CRP), have emerged as biomarkers. Their clinical relevance in dementia, however, is currently only insufficiently investigated. In the present study, hematological and inflammatory parameters were measured in the peripheral blood of 97 patients admitted to the gerontopsychiatric ward of Hannover Medical School, a university hospital in Germany, for dementia assessment. The study population comprised 20 non-demented, depressed patients (control group) and 77 demented patients who were assigned to five different groups based on their underlying dementia etiology: AD, n = 33; vascular dementia, n = 12; mixed dementia, n = 21; FTD, n = 5; and Korsakoff syndrome, n = 6. We observed neither statistically significant differences regarding total WBC populations, platelet counts, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio, nor CRP levels between the control group and the five dementia groups. CRP levels tended to be higher in patients with Korsakoff syndrome than in the control group and in AD patients. Thus, CRP could possibly play a role in the differential diagnosis of dementia. This should be investigated further in future prospective studies with larger sample sizes. WBC and platelet counts, by contrast, do not appear to be suitable biomarkers in the differential diagnosis of dementia.
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Affiliation(s)
- Sebastian Schröder
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, D-30625 Hannover, Germany
| | - Johannes Heck
- Institute for Clinical Pharmacology, Hannover Medical School, D-30625 Hannover, Germany
| | - Adrian Groh
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, D-30625 Hannover, Germany
| | - Helge Frieling
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, D-30625 Hannover, Germany
| | - Stefan Bleich
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, D-30625 Hannover, Germany
| | - Kai G. Kahl
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, D-30625 Hannover, Germany
| | - Jacobus J. Bosch
- Centre for Human Drug Research, 2333 CL Leiden, The Netherlands
- Leiden University Medical Center, 2333 CL Leiden, The Netherlands
| | - Benjamin Krichevsky
- Institute for General Practice and Palliative Care, Hannover Medical School, D-30625 Hannover, Germany
- Medical Service of the German Armed Forces, 24119 Kiel, Germany
| | - Martin Schulze-Westhoff
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, D-30625 Hannover, Germany
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