scholarly journals Photoperiodic regime influences onset of lens opacities in a non-human primate

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3258 ◽  
Author(s):  
Marko Dubicanac ◽  
Julia Strueve ◽  
Nadine Mestre-Frances ◽  
Jean-Michel Verdier ◽  
Elke Zimmermann ◽  
...  
Keyword(s):  
Age At Onset ◽  
Mouse Lemur ◽  
Chronological Age ◽  
Seasonal Cycles ◽  
Photoperiod Regime ◽  
Age Related ◽  
Mouse Lemurs ◽  
Photoperiodic Regime ◽  
Lens Opacities ◽  
Human Primate

Background Opacities of the lens are typical age-related phenomena which have a high influence on photoreception and consequently circadian rhythm. In mouse lemurs, a small bodied non-human primate, a high incidence (more than 50% when >seven years) of cataracts has been previously described during aging. Previous studies showed that photoperiodically induced accelerated annual rhythms alter some of mouse lemurs’ life history traits. Whether a modification of photoperiod also affects the onset of age dependent lens opacities has not been investigated so far. The aim of this study was therefore to characterise the type of opacity and the mouse lemurs’ age at its onset in two colonies with different photoperiodic regimen. Methods Two of the largest mouse lemur colonies in Europe were investigated: Colony 1 having a natural annual photoperiodic regime and Colony 2 with an induced accelerated annual cycle. A slit-lamp was used to determine opacities in the lens. Furthermore, a subset of all animals which showed no opacities in the lens nucleus in the first examination but developed first changes in the following examination were further examined to estimate the age at onset of opacities. In total, 387 animals were examined and 57 represented the subset for age at onset estimation. Results The first and most commonly observable opacity in the lens was nuclear sclerosis. Mouse lemurs from Colony 1 showed a delayed onset of nuclear sclerosis compared to mouse lemurs from Colony 2 (4.35 ± 1.50 years vs. 2.75 ± 0.99 years). For colony 1, the chronological age was equivalent to the number of seasonal cycles experienced by the mouse lemurs. For colony 2, in which seasonal cycles were accelerated by a factor of 1.5, mouse lemurs had experienced 4.13 ± 1.50 seasonal cycles in 2.75 ± 0.99 chronological years. Discussion Our study showed clear differences in age at the onset of nuclear sclerosis formation between lemurs kept under different photoperiodic regimes. Instead of measuring the chronological age, the number of seasonal cycles (N = four) experienced by a mouse lemur can be used to estimate the risk of beginning nuclear sclerosis formation. Ophthalmological examinations should be taken into account when animals older than 5–6 seasonal cycles are used for experiments in which unrestricted visual ability has to be ensured. This study is the first to assess and demonstrate the influence of annual photoperiod regime on the incidence of lens opacities in a non-human primate.

scholarly journals Photoperiodic regime influences onset of lens opacities in a non-human primate

2017 ◽  
Author(s):  
Marko Dubicanac ◽  
Julia Strueve ◽  
Nadine Mestre-Frances ◽  
Jean-Michel Verdier ◽  
Elke Zimmermann ◽  
...  
Keyword(s):  
Age At Onset ◽  
Mouse Lemur ◽  
Chronological Age ◽  
Seasonal Cycles ◽  
Photoperiod Regime ◽  
Age Related ◽  
Mouse Lemurs ◽  
Photoperiodic Regime ◽  
Lens Opacities ◽  
Human Primate

Background. Opacities of the lens are typical age related phenomena which have high influence on photoreception and consequently circadian rhythm. In mouse lemurs, a small bodied non-human primate, a high incidence (more than 50% when > 7 years) of cataract has been previously described during aging. Previous studies showed that photoperiodical induced accelerated annual rhythms alter some of mouse lemurs’ life history traits. Whether a modification of photoperiod also affects the onset of age dependent lens opacities has not been investigated so far. The aim of this study was therefore to characterize the type of opacity and the mouse lemurs’ age at its onset in two colonies with different photoperiodic regimen. Methods. Two of the largest mouse lemur colonies in Europe have been investigated; Colony 1 with a natural annual photoperiodic regime and Colony 2 with an induced accelerated annual cycle. A Slit-lamp was used to determine opacities in the lens and a subset of all animals which showed no opacities in the lens nucleus in the first examination but developed first changes in the following examination were further used to estimate the age at onset of opacities. In total 387 animals were examined and 57 represent the subset for age at onset estimation. Results. The first and most common observable opacity in the lens was nuclear sclerosis. Mouse lemurs from Colony 1 showed a delayed onset of nuclear sclerosis compared to mouse lemurs of Colony 2 (4.35 ± 1.50 years vs. 2.75 ± 0.99 years). For colony 1, the chronological age was equivalent to the number of seasonal cycles experienced by the mouse lemurs. For colony 2, in which seasonal cycles are accelerated by factor 1.5, mouse lemurs had experienced 4.13 ± 1.50 seasonal cycles in 2.75 ± 0.99 chronological years. Discussion. Our study showed clear differences in the age at the onset of nuclear sclerosis formation between lemurs kept under different photoperiodic regimes. Instead of measuring the chronological age, the number of seasonal cycles (N = 4) experienced by a mouse lemur can be used as an estimation for risk of beginning NS formation. Ophthalmological investigations should be taken into account when animals older than 5 - 6 seasonal cycles are used for experiments in which unrestricted visual ability has to be ensured. This study is the first to assess and demonstrate the influence of annual photoperiod regime on the incidence of lens opacities in a non-human primate.

scholarly journals Photoperiodic regime influences onset of lens opacities in a non-human primate

2017 ◽  
Author(s):  
Marko Dubicanac ◽  
Julia Strueve ◽  
Nadine Mestre-Frances ◽  
Jean-Michel Verdier ◽  
Elke Zimmermann ◽  
...  
Keyword(s):  
Age At Onset ◽  
Mouse Lemur ◽  
Chronological Age ◽  
Seasonal Cycles ◽  
Photoperiod Regime ◽  
Age Related ◽  
Mouse Lemurs ◽  
Photoperiodic Regime ◽  
Lens Opacities ◽  
Human Primate

Background. Opacities of the lens are typical age related phenomena which have high influence on photoreception and consequently circadian rhythm. In mouse lemurs, a small bodied non-human primate, a high incidence (more than 50% when > 7 years) of cataract has been previously described during aging. Previous studies showed that photoperiodical induced accelerated annual rhythms alter some of mouse lemurs’ life history traits. Whether a modification of photoperiod also affects the onset of age dependent lens opacities has not been investigated so far. The aim of this study was therefore to characterize the type of opacity and the mouse lemurs’ age at its onset in two colonies with different photoperiodic regimen. Methods. Two of the largest mouse lemur colonies in Europe have been investigated; Colony 1 with a natural annual photoperiodic regime and Colony 2 with an induced accelerated annual cycle. A Slit-lamp was used to determine opacities in the lens and a subset of all animals which showed no opacities in the lens nucleus in the first examination but developed first changes in the following examination were further used to estimate the age at onset of opacities. In total 387 animals were examined and 57 represent the subset for age at onset estimation. Results. The first and most common observable opacity in the lens was nuclear sclerosis. Mouse lemurs from Colony 1 showed a delayed onset of nuclear sclerosis compared to mouse lemurs of Colony 2 (4.35 ± 1.50 years vs. 2.75 ± 0.99 years). For colony 1, the chronological age was equivalent to the number of seasonal cycles experienced by the mouse lemurs. For colony 2, in which seasonal cycles are accelerated by factor 1.5, mouse lemurs had experienced 4.13 ± 1.50 seasonal cycles in 2.75 ± 0.99 chronological years. Discussion. Our study showed clear differences in the age at the onset of nuclear sclerosis formation between lemurs kept under different photoperiodic regimes. Instead of measuring the chronological age, the number of seasonal cycles (N = 4) experienced by a mouse lemur can be used as an estimation for risk of beginning NS formation. Ophthalmological investigations should be taken into account when animals older than 5 - 6 seasonal cycles are used for experiments in which unrestricted visual ability has to be ensured. This study is the first to assess and demonstrate the influence of annual photoperiod regime on the incidence of lens opacities in a non-human primate.

scholarly journals A Biomarker-based Biological Age in UK Biobank: Composition and Prediction of Mortality and Hospital Admissions

2021 ◽  
Author(s):  
Mei Sum Chan ◽  
Matthew Arnold ◽  
Alison Offer ◽  
Imen Hammami ◽  
Marion Mafham ◽  
...  
Keyword(s):  
Principal Components ◽  
Hospital Admissions ◽  
Later Life ◽  
Chronological Age ◽  
Uk Biobank ◽  
Hand Grip ◽  
Cox Proportional Hazard ◽  
Prediction Of Mortality ◽  
Age Related ◽  
Cox Proportional Hazard Models

Abstract Background Chronological age is the strongest risk factor for most chronic diseases. Developing a biomarker-based age and understanding its most important contributing biomarkers may shed light on the effects of age on later-life health and inform opportunities for disease prevention. Methods A subpopulation of 141 254 individuals healthy at baseline were studied, from among 480 019 UK Biobank participants aged 40–70 recruited in 2006–2010, and followed up for 6–12 years via linked death and secondary care records. Principal components of 72 biomarkers measured at baseline were characterized and used to construct sex-specific composite biomarker ages using the Klemera Doubal method, which derived a weighted sum of biomarker principal components based on their linear associations with chronological age. Biomarker importance in the biomarker ages was assessed by the proportion of the variation in the biomarker ages that each explained. The proportions of the overall biomarker and chronological age effects on mortality and age-related hospital admissions explained by the biomarker ages were compared using likelihoods in Cox proportional hazard models. Results Reduced lung function, kidney function, reaction time, insulin-like growth factor 1, hand grip strength, and higher blood pressure were key contributors to the derived biomarker age in both men and women. The biomarker ages accounted for >65% and >84% of the apparent effect of age on mortality and hospital admissions for the healthy and whole populations, respectively, and significantly improved prediction of mortality (p < .001) and hospital admissions (p < 1 × 10−10) over chronological age alone. Conclusions This study suggests that a broader, multisystem approach to research and prevention of diseases of aging warrants consideration.

Molecular liver fingerprint reflects the seasonal physiology of the grey mouse lemur (Microcebus murinus) during winter

2021 ◽  
Author(s):  
Blandine Chazarin ◽  
Margaux Benhaim-Delarbre ◽  
Charlotte Brun ◽  
Aude Anzeraey ◽  
Fabrice Bertile ◽  
...  
Keyword(s):  
Glucose Intolerance ◽  
Molecular Mechanisms ◽  
Mouse Lemur ◽  
Primate Species ◽  
Whole Body ◽  
Microcebus Murinus ◽  
Late Winter ◽  
Pathological State ◽  
Fat Reserves ◽  
Mouse Lemurs

Grey mouse lemurs (Microcebus murinus) are a primate species exhibiting strong physiological seasonality in response to environmental energetic constraint. They notably store large amounts of lipids during early winter (EW), which are thereafter mobilized during late winter (LW), when food availability is low. In addition, they develop glucose intolerance in LW only. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, which seasonal regulations of metabolism and reproduction are comparable to their wild counterparts, during the phases of either constitution or use of fat reserves. We highlight profound changes that reflect fat accretion in EW at the whole-body level, however, without triggering an ectopic storage of fat in the liver. Moreover, molecular regulations would be in line with the lowering of liver glucose utilization in LW, and thus with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways, which suggests that glucose intolerance does not reach a pathological stage. Finally, fat mobilization in LW appeared possibly linked to reactivation of the reproductive system and enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Altogether, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while avoiding reaching a pathological state despite large lipid fluxes. This work emphasizes how the mouse lemur is of primary interest for identifying molecular mechanisms relevant to biomedical field.

A metabolomic aging clock using human CSF

2021 ◽  
Author(s):  
Nathan Hwangbo ◽  
Xinyu Zhang ◽  
Daniel Raftery ◽  
Haiwei Gu ◽  
Shu-Ching Hu ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Healthy Aging ◽  
Prediction Models ◽  
Mass Spectrometry Analysis ◽  
Chronological Age ◽  
Healthy Human ◽  
Missing Data Imputation ◽  
Spectrometry Analysis ◽  
Residual Variation ◽  
Age Related

Abstract Quantifying the physiology of aging is essential for improving our understanding of age-related disease and the heterogeneity of healthy aging. Recent studies have shown that in regression models using “-omic” platforms to predict chronological age, residual variation in predicted age is correlated with health outcomes, and suggest that these “omic clocks” provide measures of biological age. This paper presents predictive models for age using metabolomic profiles of cerebrospinal fluid from healthy human subjects, and finds that metabolite and lipid data are generally able to predict chronological age within 10 years. We use these models to predict the age of a cohort of subjects with Alzheimer’s and Parkinson’s disease and find an increase in prediction error, potentially indicating that the relationship between the metabolome and chronological age differs with these diseases. However, evidence is not found to support the hypothesis that our models will consistently over-predict the age of these subjects. In our analysis of control subjects, we find the carnitine shuttle, sucrose, biopterin, vitamin E metabolism, tryptophan, and tyrosine to be the most associated with age. We showcase the potential usefulness of age prediction models in a small dataset (n = 85), and discuss techniques for drift correction, missing data imputation, and regularized regression, which can be used to help mitigate the statistical challenges that commonly arise in this setting. To our knowledge, this work presents the first multivariate predictive metabolomic and lipidomic models for age using mass spectrometry analysis of cerebrospinal fluid.

scholarly journals The Gut Microbiota and Healthy Aging: A Mini-Review

Gerontology ◽  
2018 ◽  
Vol 64 (6) ◽  
pp. 513-520 ◽  
Author(s):  
Sangkyu Kim ◽  
S. Michal Jazwinski
Keyword(s):  
Gut Microbiota ◽  
Individual Variation ◽  
Gut Microbiome ◽  
Chronological Age ◽  
Low Grade ◽  
Beneficial Effects ◽  
Gut Dysbiosis ◽  
Age Related ◽  
Host Health ◽  
Nutrient Signaling

The gut microbiota shows a wide inter-individual variation, but its within-individual variation is relatively stable over time. A functional core microbiome, provided by abundant bacterial taxa, seems to be common to various human hosts regardless of their gender, geographic location, and age. With advancing chronological age, the gut microbiota becomes more diverse and variable. However, when measures of biological age are used with adjustment for chronological age, overall richness decreases, while a certain group of bacteria associated with frailty increases. This highlights the importance of considering biological or functional measures of aging. Studies using model organisms indicate that age-related gut dysbiosis may contribute to unhealthy aging and reduced longevity. The gut microbiome depends on the host nutrient signaling pathways for its beneficial effects on host health and lifespan, and gut dysbiosis disrupting the interdependence may diminish the beneficial effects or even have reverse effects. Gut dysbiosis can trigger the innate immune response and chronic low-grade inflammation, leading to many age-related degenerative pathologies and unhealthy aging. The gut microbiota communicates with the host through various biomolecules, nutrient signaling-independent pathways, and epigenetic mechanisms. Disturbance of these communications by age-related gut dysbiosis can affect the host health and lifespan. This may explain the impact of the gut microbiome on health and aging.

scholarly journals The effects of a national highway on the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, Madagascar

Oryx ◽  
2017 ◽  
Vol 53 (4) ◽  
pp. 727-731 ◽  
Author(s):  
Malcolm S. Ramsay ◽  
Andriamahery Razafindrakoto ◽  
Shawn M. Lehman
Keyword(s):  
National Park ◽  
Mouse Lemur ◽  
Population Subdivision ◽  
Empirical Testing ◽  
Future Studies ◽  
North West ◽  
Mouse Lemurs ◽  
Interior Forest ◽  
Males And Females ◽  
Dispersal Events

AbstractAlthough roads are often assumed to be barriers to the dispersal of arboreal species, there has been little empirical testing of this assumption. If arboreal animals are unable to cross roads, population subdivision may occur, or resources may become inaccessible. We tested the hypothesis that Route Nationale 4 (RN4), a paved highway, was a barrier to movement and dispersal of the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, in north-west Madagascar. During June–August 2015 we conducted a capture–mark–recapture study at three sites: two adjacent to RN4 and one within intact forest without a potential barrier. During 2,294 trap nights we captured 120 golden-brown mouse lemurs 1,032 times. In roadside habitats we captured significantly more males than females, whereas the opposite was the case in interior forest habitat. We detected eighteen crossings of highway transects by nine individuals; however, all potential dispersal events involved males. In roadside habitat, movement was significantly inhibited in both males and females. We present some of the first data on the effects of roads on movement patterns in arboreal Malagasy mammals, showing species- and sex-biased effects of roads as dispersal barriers. Our findings indicate that roads may not be complete barriers to dispersal in lemurs. We recommend that conservation managers and scientists examine explicitly the effects of roads and natural arboreal bridges in Madagascar in future studies.

scholarly journals Survival is reduced when endogenous period deviates from 24 h in a non-human primate, supporting the circadian resonance theory

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Clara Hozer ◽  
Martine Perret ◽  
Samuel Pavard ◽  
Fabien Pifferi
Keyword(s):  
Circadian Rhythms ◽  
Circadian Clock ◽  
Microcebus Murinus ◽  
Circadian Period ◽  
Biological Functions ◽  
Resonance Theory ◽  
Aging Research ◽  
Mouse Lemurs ◽  
Living Organisms ◽  
Human Primate

Abstract Circadian rhythms are ubiquitous attributes across living organisms and allow the coordination of internal biological functions with optimal phases of the environment, suggesting a significant adaptive advantage. The endogenous period called tau lies close to 24 h and is thought to be implicated in individuals’ fitness: according to the circadian resonance theory, fitness is reduced when tau gets far from 24 h. In this study, we measured the endogenous period of 142 mouse lemurs (Microcebus murinus), and analyzed how it is related to their survival. We found different effects according to sex and season. No impact of tau on mortality was found in females. However, in males, the deviation of tau from 24 h substantially correlates with an increase in mortality, particularly during the inactive season (winter). These results, comparable to other observations in mice or drosophila, show that captive gray mouse lemurs enjoy better fitness when their circadian period closely matches the environmental periodicity. In addition to their deep implications in health and aging research, these results raise further ecological and evolutionary issues regarding the relationships between fitness and circadian clock.

scholarly journals Early-Onset Parkinson Disease Screening in Patients From Nigeria

2021 ◽  
Vol 11 ◽  
Author(s):  
Lukasz M. Milanowski ◽  
Olajumoke Oshinaike ◽  
Benjamin J. Broadway ◽  
Jennifer A. Lindemann ◽  
Alexandra I. Soto-Beasley ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Parkinson Disease ◽  
Neurodegenerative Diseases ◽  
Early Onset ◽  
Local Population ◽  
Age At Onset ◽  
Compound Heterozygous ◽  
Loss Of Function ◽  
African Countries ◽  
Age Related

Introduction: Nigeria is one of the most populated countries in the world; however, there is a scarcity of studies in patients with age-related neurodegenerative diseases, such as Parkinson disease (PD). The aim of this study was to screen patients with PD including a small cohort of early-onset PD (EOPD) cases from Nigeria for PRKN, PINK1, DJ1, SNCA multiplication, and LRRK2 p.G2019S.Methods: We assembled a cohort of 109 Nigerian patients with PD from the four main Nigerian tribes: Yoruba, Igbo, Edo, and Hausa. Fifteen cases [14 from the Yoruba tribe (93.3%)] had EOPD (defined as age-at-onset <50 years). All patients with EOPD were sequenced for the coding regions of PRKN, PINK1, and DJ1. Exon dosage analysis was performed with a multiplex ligation-dependent probe amplification assay, which also included a SNCA probe and LRRK2 p.G2019S. We screened for LRRK2 p.G2019S in the entire PD cohort using a genotyping assay. The PINK1 p.R501Q functional analysis was conducted.Results: In 15 patients with EOPD, 22 variants were observed [PRKN, 9 (40.9%); PINK1, 10 (45.5%); and DJ1, 3 (13.6%)]. Three (13.6%) rare, nonsynonymous variants were identified, but no homozygous or compound heterozygous carriers were found. No exonic rearrangements were present in the three genes, and no carriers of SNCA genomic multiplications or LRRK2 p.G2019S were identified. The PINK1 p.R501Q functional analysis revealed pathogenic loss of function.Conclusion: More studies on age-related neurodegenerative diseases are needed in sub-Saharan African countries, including Nigeria. Population-specific variation may provide insight into the genes involved in PD in the local population but may also contribute to larger studiesperformed in White and Asian populations.

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