scholarly journals From climate warming to accelerated cellular ageing: an experimental study in wild birds

2021 ◽  
Author(s):  
Antoine STIER ◽  
Bin-Yan Hsu ◽  
Nina Cossin-Sevrin ◽  
Natacha Garcin ◽  
Suvi Ruuskanen
Keyword(s):  
Ambient Temperature ◽  
Climate Warming ◽  
Early Life ◽  
Heat Waves ◽  
Bird Species ◽  
Wild Birds ◽  
Telomere Maintenance ◽  
Term Survival ◽  
Telomere Shortening ◽  
Cellular Ageing

Climate change is increasing both the average ambient temperature and the frequency and severity of heat waves. While direct mortality induced by heat waves is increasingly reported, sub-lethal effects are also likely to impact wild populations. We hypothesized that accelerated ageing could be a cost of being exposed to higher ambient temperature, especially in early-life when thermoregulatory capacities are not fully developed. We tested this hypothesis in wild great tit (Parus major) by experimentally increasing nest box temperature by ca. 2 degrees during postnatal growth and measuring telomere length, a biomarker of cellular ageing predictive of survival prospects in many bird species. While increasing early-life temperature does not affect growth or survival to fledging, it accelerates telomere shortening and reduces medium-term survival from 34% to 19%. Heat-induced telomere shortening was not explained by oxidative stress, but more likely by an increase in energy demand (i.e. higher thyroid hormones levels, increased expression of glucocorticoid receptor, increased mitochondrial density) leading to a reduction in telomere maintenance mechanisms (i.e. decrease in the gene expression of telomerase and protective shelterin). Our results thus suggest that climate warming can affect ageing rate in wild birds, with potential impact on population dynamics and persistence.

scholarly journals Prenatal thyroid hormones accelerate postnatal growth and telomere shortening in wild great tits

2021 ◽  
Author(s):  
Bin-Yan Hsu ◽  
Nina Cossin-Sevrin ◽  
Antoine Stier ◽  
Suvi Ruuskanen
Keyword(s):  
Oxidative Stress ◽  
Thyroid Hormones ◽  
Telomere Length ◽  
Early Life ◽  
Later Life ◽  
Delayed Effect ◽  
Oxidative Stress Biomarkers ◽  
Term Survival ◽  
Telomere Shortening ◽  
The Impact

Early-life environment is known to affect later-life health and disease, which could be mediated by the early-life programming of telomere length, a key hallmark of ageing. According to the fetal programming of telomere biology hypothesis, variation in prenatal exposure to hormones is likely to influence telomere length. Yet the contribution of key metabolic hormones, i.e. thyroid hormones (THs), has been largely ignored. We recently showed that in contrast to predictions, exposure to elevated prenatal THs increased postnatal telomere length in wild collared flycatchers, but the generality of such effect, its underlying proximate mechanisms and consequences on survival have not been investigated. We therefore conducted a comprehensive study evaluating the impact of THs on potential drivers of telomere dynamics (growth, post-natal THs, mitochondria and oxidative stress), telomere length and medium-term survival using wild great tits as a model system. While prenatal THs did not significantly affect telomere length after hatching (i.e. day 7), they influenced postnatal telomere shortening (i.e. shorter telomeres at day 14 and the following winter) but not apparent survival. Circulating THs, mitochondrial density or oxidative stress biomarkers were not significantly influenced, whereas TH-supplemented group showed accelerated growth, which may explain the observed delayed effect on telomeres. We discuss several alternative hypotheses that may explain the contrast with our previous findings in flycatchers. Given that shorter telomeres in early life tend to be carried until adulthood and are often associated with decreased survival prospects, the effects of prenatal THs on telomeres may have long-lasting effects on senescence.

Regulation And Effect Of Telomerase And Telomeric Length In Stem Cells

2020 ◽  
Vol 15 ◽  
Author(s):  
Basak Celtikci ◽  
Gulnihal Kulaksiz Erkmen ◽  
Zeliha Gunnur Dikmen
Keyword(s):  
Telomere Length ◽  
Somatic Cells ◽  
Telomere Maintenance ◽  
The Other ◽  
Telomerase Reverse Transcriptase ◽  
Human Telomerase Reverse Transcriptase ◽  
Telomere Shortening ◽  
Maintenance Mechanism ◽  
Associated Diseases ◽  
Human Telomerase

: Telomeres are the protective end caps of eukaryotic chromosomes and they decide the proliferative lifespan of somatic cells, as the guardians of the cell replication. Telomere length in leucocytes reflects telomere length in other somatic cells. Leucocyte telomere length can be a biomarker of human ageing. The risk of diseases, which are associated with reduced cell proliferation and tissue degeneration, including aging or aging-associated diseases, such as dyskeratosis congenita, cardiovascular diseases, pulmonary fibrosis and aplastic anemia, are correlated with an increase in short telomeres. On the other hand, the risk of diseases, which are associated with increased proliferative growth, including major cancers, is correlated with long telomeres. In most of the cancers, a telomere maintenance mechanism during DNA replication is essential. The reactivation of the functional ribonucleoprotein holoenzyme complex [telomerase] starts the cascade from normal and premalignant somatic cells to advanced malignant cells. Telomerase is overexpressed during the development of cancer and embryonic stem cells, through controlling genome integrity, cancer formation and stemness. Cancer cells have mechanisms to maintain telomeres to avoid initiation of cellular senescence or apoptosis, and halting cell division by critically short telomeres. Modulation of the human telomerase reverse transcriptase is the ratelimiting step for the production of functional telomerase and the telomere maintenance. Human telomerase reverse transcriptase promoter promotes its gene expression only in tumor cells, but not in normal cells. Some cancers activate an alternative lengthening of telomeres maintenance mechanism via DNA recombination to unshorten their telomeres. Not only heritability but also oxidative stress, inflammation, environmental factors, and therapeutic interventions have an effect on telomere shortening, explaining the variability in telomere length across individuals. There have been a large number of publications, which correlate human diseases with progressive telomere shortening. Telomere length of an individual at birth is also important to follow up telomere shortening, and it can be used as biomarkers for healthy aging. On the other hand, understanding of cellular stress factors, which affect stem cell behavior, will be useful in regeneration or treatment in cancer and age-associated diseases. In this review, we will understand the connection between stem cell and telomere biology, cancer, and aging-associated diseases. This connection may be useful for discovering novel drug targets and improve outcomes for patients having cancer and aging-associated diseases.

scholarly journals Predicting the Future Distribution of Ara rubrogenys, an Endemic Endangered Bird Species of the Andes, Taking into Account Trophic Interactions

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 94
Author(s):  
Alain Hambuckers ◽  
Simon de Harenne ◽  
Eberth Rocha Ledezma ◽  
Lilian Zúñiga Zeballos ◽  
Louis François
Keyword(s):  
Food Resource ◽  
Bird Species ◽  
Co2 Concentration ◽  
Distribution Models ◽  
Plant Resources ◽  
Term Survival ◽  
The Andes ◽  
Vegetation Models ◽  
Fertilizing Effect ◽  
The Impact

Species distribution models (SDMs) are commonly used with climate only to predict animal distribution changes. This approach however neglects the evolution of other components of the niche, like food resource availability. SDMs are also commonly used with plants. This also suffers limitations, notably an inability to capture the fertilizing effect of the rising CO2 concentration strengthening resilience to water stress. Alternatively, process-based dynamic vegetation models (DVMs) respond to CO2 concentration. To test the impact of the plant modelling method to model plant resources of animals, we studied the distribution of a Bolivian macaw, assuming that, under future climate, DVMs produce more conservative results than SDMs. We modelled the bird with an SDM driven by climate. For the plant, we used SDMs or a DVM. Under future climates, the macaw SDM showed increased probabilities of presence over the area of distribution and connected range extensions. For plants, SDMs did not forecast overall response. By contrast, the DVM produced increases of productivity, occupancy and diversity, also towards higher altitudes. The results offered positive perspectives for the macaw, more optimistic with the DVM than with the SDMs, than initially assumed. Nevertheless, major common threats remain, challenging the short-term survival of the macaw.

scholarly journals Association between ambient temperature and heat waves with mortality in South Asia: Systematic review and meta-analysis

2021 ◽  
Vol 146 ◽  
pp. 106170
Author(s):  
Asya Dimitrova ◽  
Vijendra Ingole ◽  
Xavier Basagaña ◽  
Otavio Ranzani ◽  
Carles Milà ◽  
...  
Keyword(s):  
Systematic Review ◽  
Ambient Temperature ◽  
South Asia ◽  
Heat Waves ◽  
Meta Analysis

scholarly journals Abundance, diversity and daily activity of terrestrial mammal and bird species in disturbed and undisturbed limestone habitats using camera trapping, Central Thailand

2021 ◽  
Vol 22 (8) ◽  
Author(s):  
MANANYA PLA-ARD ◽  
WIPAVEE HOONHEANG ◽  
BUNYATHIPORN KAEWDEE ◽  
TARAPON PANGANTA ◽  
KHWANRUTAI CHARASPET ◽  
...  
Keyword(s):  
Daily Activity ◽  
Bird Species ◽  
Wild Birds ◽  
Camera Trapping ◽  
Mountainous Area ◽  
Mining Activities ◽  
Natural Habitats ◽  
Terrestrial Mammal ◽  
Significant Difference ◽  
Central Thailand

Abstract: Pla-ard M, Hoonheang W, Kaewdee B, Panganta T, Charaspet K, Khoiesri N, Paansri P, Kanka P, Chanachai Y, Thongbanthum J, Bangthong P, Sukmasuang R. 2021. Abundance, diversity and daily activity of terrestrial mammal and bird species in disturbed and undisturbed limestone habitats using camera trapping, Central Thailand. Biodiversitas 22: 3620-3631.  This study on the abundance, diversity and daily activity of terrestrial mammal and bird species was conducted in the limestone mountainous area of Central Thailand, located on the east of Dong Phaya Yen-Khao Yai forest complex. Camera traps were placed in both habitats disturbed by limestone mining and undisturbed habitat areas. From the study, a total of 38 species of mammals and birds from 27 families in 13 orders were recorded, including 15 species of mammals from 6 orders, 12 families and 23 species of birds from 14 families in 7 orders. Fifteen species of mammals were recorded in the undisturbed area and 11 were recorded in the disturbed area, with the Malayan Pangolin, Small Indian Civet and Grey-bellied Squirrel found in the undisturbed area. However, the number of bird species in the limestone mining area was larger than in the undisturbed area. It was also found that there was no difference in the overall abundance and diversity of mammalian species between disturbed and undisturbed areas, which is not in accordance with the hypothesis. But in the case of wild birds, the relative abundance of wild birds was found to differ significantly between areas. A high number was found in the areas with mining activities, although there was no difference in the diversity index of the two areas. However, it was found that when the combined data was analyzed, there was a significant difference in the daily activity of both mammals and wild birds in both areas. Many rare wildlife species were recorded during this study, for example, the Malayan Pangolin, Serow, Northern Pig-tailed Macaque, Rufous Limestone-babbler, Golden Jackal, Leopard Cat, Large-toothed Ferret Badger, Small Asian Mongoose, Common Palm Civet, Small Indian Civet, Malayan Porcupine. The key measure proposed is to preserve some natural habitats within the areas with mining activities, as wildlife remains in the area.

scholarly journals SIRT1 contributes to telomere maintenance and augments global homologous recombination

2010 ◽  
Vol 191 (7) ◽  
pp. 1299-1313 ◽  
Author(s):  
Jose A. Palacios ◽  
Daniel Herranz ◽  
Maria Luigia De Bonis ◽  
Susana Velasco ◽  
Manuel Serrano ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Telomerase Activity ◽  
Histone Deacetylation ◽  
Telomere Maintenance ◽  
Loss Of Function ◽  
Entire Genome ◽  
Telomere Shortening ◽  
Telomere Biology ◽  
Sir Complex

Yeast Sir2 deacetylase is a component of the silent information regulator (SIR) complex encompassing Sir2/Sir3/Sir4. Sir2 is recruited to telomeres through Rap1, and this complex spreads into subtelomeric DNA via histone deacetylation. However, potential functions at telomeres for SIRT1, the mammalian orthologue of yeast Sir2, are less clear. We studied both loss of function (SIRT1 deficient) and gain of function (SIRT1super) mouse models. Our results indicate that SIRT1 is a positive regulator of telomere length in vivo and attenuates telomere shortening associated with aging, an effect dependent on telomerase activity. Using chromatin immunoprecipitation assays, we find that SIRT1 interacts with telomeric repeats in vivo. In addition, SIRT1 overexpression increases homologous recombination throughout the entire genome, including telomeres, centromeres, and chromosome arms. These findings link SIRT1 to telomere biology and global DNA repair and provide new mechanistic explanations for the known functions of SIRT1 in protection from DNA damage and some age-associated pathologies.

scholarly journals Telomere length and human hippocampal neurogenesis

2020 ◽  
Vol 45 (13) ◽  
pp. 2239-2247 ◽  
Author(s):  
Alish B. Palmos ◽  
Rodrigo R. R. Duarte ◽  
Demelza M. Smeeth ◽  
Erin C. Hedges ◽  
Douglas F. Nixon ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Psychiatric Disorder ◽  
Telomere Length ◽  
Gene Networks ◽  
Hippocampal Neurogenesis ◽  
Telomere Maintenance ◽  
Adult Hippocampal Neurogenesis ◽  
Telomere Shortening ◽  
Age Related

Abstract Short telomere length is a risk factor for age-related disease, but it is also associated with reduced hippocampal volumes, age-related cognitive decline and psychiatric disorder risk. The current study explored whether telomere shortening might have an influence on cognitive function and psychiatric disorder pathophysiology, via its hypothesised effects on adult hippocampal neurogenesis. We modelled telomere shortening in human hippocampal progenitor cells in vitro using a serial passaging protocol that mimics the end-replication problem. Serially passaged progenitors demonstrated shorter telomeres (P ≤ 0.05), and reduced rates of cell proliferation (P ≤ 0.001), with no changes in the ability of cells to differentiate into neurons or glia. RNA-sequencing and gene-set enrichment analyses revealed an effect of cell ageing on gene networks related to neurogenesis, telomere maintenance, cell senescence and cytokine production. Downregulated transcripts in our model showed a significant overlap with genes regulating cognitive function (P ≤ 1 × 10−5), and risk for schizophrenia (P ≤ 1 × 10−10) and bipolar disorder (P ≤ 0.005). Collectively, our results suggest that telomere shortening could represent a mechanism that moderates the proliferative capacity of human hippocampal progenitors, which may subsequently impact on human cognitive function and psychiatric disorder pathophysiology.

scholarly journals 3106 The influence of early life experience on telomere length, health, and behavior of domestic cats

2019 ◽  
Vol 3 (s1) ◽  
pp. 23-23
Author(s):  
Mikel Maria Delgado ◽  
Melissa Bain ◽  
Tony C.A.T. Buffington
Keyword(s):  
Telomere Length ◽  
Reference Gene ◽  
Early Life ◽  
Maternal Separation ◽  
Single Copy ◽  
Physical Contact ◽  
Telomere Shortening ◽  
Blood Samples ◽  
Future Studies ◽  
And Behavior

OBJECTIVES/SPECIFIC AIMS: The primary objective of this research is to determine whether being hand-reared, and deprived of early maternal interaction, will affect telomere length in orphaned kittens. The secondary goal is to examine how early maternal separation impacts the health, growth and behavior of orphaned kittens. METHODS/STUDY POPULATION: Kittens were fostered through local rescue groups and shelters. We collected blood samples from 42 orphaned kittens during the first week of their lives. Due to high mortality of this population, we obtained a second blood sample at eight weeks of age from only 30 of these kittens. We collected blood samples from 12 control kittens raised with mothers at during the first and eighth weeks of life. Blood samples are currently being processed with real time quantitative PCR (qPCR) by the Real-time PCR Research and Diagnostics Core Facility at the UC Davis School of Veterinary Medicine (SVM). This includes RNA extraction, cDNA synthesis, Reference Gene Validation, and qPCR analysis. Relative telomere length (RTL) will be calculated by comparing the average telomere abundance across three samples cells with that of a reference gene (single copy number) for each sample. The resulting T/S ratio (telomere to single copy) is proportional to the average telomere length. If T/S = 1, then telomere length in the sample and the reference are the same. RESULTS/ANTICIPATED RESULTS: Because telomeres show the fastest rate of shortening early in life, we predict that maternal separation will increase the rate of telomere shortening in kittens. We also predict that the telomeres of orphaned kittens will be shorter at both one week and eight weeks of age, compared to controls. DISCUSSION/SIGNIFICANCE OF IMPACT: This study will increase our understanding of early life adversity, a finding that can translate to other mammals. It will inform the practice of fostering neonatal kittens, and illuminate whether these kittens might be at higher risk than mother-reared kittens for health problems (which could be investigated in future studies). If significant telomere shortening occurs between collection periods, then future studies can take more frequent blood samples to determine what stages of early development are potentially most sensitive. If differences between groups are found, this will establish a protocol for several future research projects, such as testing whether these detrimental effects can be mitigated by environmental enrichment via activation of telomerase. Telomerase is an enzyme that appears to counteract some shortening of telomeres, and is activated by several external factors, including exercise. Thus, a logical follow up study would be developing and testing age-specific and appropriate enrichments that may activate telomerase and reduce telomere loss. Physical contact, whether human, mother, or siblings, is another possible source of telomerase activation in young kittens. Future studies also could quantify the effects of different sources of physical contact on telomere shortening. Finally, a positive finding would establish a need for longitudinal studies of the effects of early weaning on feline health and behavior and whether differences in early-life telomere lengths predict health and longevity of cats.

scholarly journals Essential roles for Pot1b in HSC self-renewal and survival

Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6068-6077 ◽  
Author(s):  
Yang Wang ◽  
Mei-Feng Shen ◽  
Sandy Chang
Keyword(s):  
Progenitor Cell ◽  
Essential Role ◽  
Dyskeratosis Congenita ◽  
Telomere Maintenance ◽  
Wild Type ◽  
Telomere Shortening ◽  
Damage Response ◽  
First Time

Abstract Maintenance of mammalian telomeres requires both the enzyme telomerase and shelterin, which protect telomeres from inappropriately activating DNA damage response checkpoints. Dyskeratosis congenita is an inherited BM failure syndrome disorder because of defects in telomere maintenance. We have previously shown that deletion of the shelterin component Pot1b in the setting of telomerase haploinsufficiency results in rapid telomere shortening and fatal BM failure in mice, eliciting phenotypes that strongly resemble human syskeratosis congenita. However, it was unclear why BM failure occurred in the setting of Pot1b deletion. In this study, we show that Pot1b plays an essential role in HSC survival. Deletion of Pot1b results in increased apoptosis, leading to severe depletion of the HSC reserve. BM from Pot1bΔ/Δ mice cannot compete with BM from wild-type mice to provide multilineage reconstitution, indicating that there is an intrinsic requirement for Pot1b the maintenance of HSC function in vivo. Elimination of the p53-dependent apoptotic function increased HSC survival and significantly extended the lifespan of Pot1b-null mice deficient in telomerase function. Our results document for the first time the essential role of a component of the shelterin complex in the maintenance of HSC and progenitor cell survival.

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