Search results for "senescence."
showing 10 items of 335 documents
Lifecycle of Polycystic Ovary Syndrome (PCOS): From In Utero to Menopause
2013
Context: Polycystic ovary syndrome (PCOS) is diagnosed during the reproductive years when women present with 2 of 3 of the following criteria: 1) irregular menstrual cycles or anovulation, 2) hyperandrogenism, and 3) PCO morphology. However, there is evidence that PCOS can be identified from early infancy to puberty based on predisposing environmental influences. There is also increasing information about the PCOS phenotype after menopause. The goal of this review is to summarize current knowledge about the appearance of PCOS at different life stages and the influence of reproductive maturation and senescence on the PCOS phenotype. Evidence: PubMed, the bibliography from the Evidence-Based …
Age-associated telomere shortening in mouse oocytes
2013
Abstract Background Oocytes may undergo two types of aging. The first is induced by exposure to an aged ovarian microenvironment before being ovulated, known as ‘reproductive or maternal aging’, and the second by either a prolonged stay in the oviduct before fertilization or in vitro aging prior to insemination, known as ‘postovulatory aging’. However, the molecular mechanisms underlying these aging processes remain to be elucidated. As telomere shortening in cultured somatic cells triggers replicative senescence, telomere shortening in oocytes during reproductive and postovulatory aging may predict developmental competence. This study aimed to ascertain the mechanisms underlying altered te…
Telomeres in the Brain Cortex of Patients with Major Depressive Disorder
2014
Telomeres are complex structures formed by the end of the DNA molecule at the tip of each chromosomal arm. The repeated (TTAGGG) telomeric sequence progressively shortens during lifespan because it cannot be replicated as somatic cells divide, and is highly susceptible to breakage by free radicals. Critically shortened telomeres activate the genetic program of cell senescence and/or apoptosis. The telomere length measured in peripheral blood leucocytes is considered a reliable marker of biological age, mortality risk and exposure to various pathological conditions, including cardiovascular disease, dementia, and metabolic syndrome. Telomere erosion has been observed in psychiatric disorders…
Dietary prevention of visual function and cognitive decline by omega-3 polyunsaturated fatty acids in Senescence Accelerated Mouse P8 (SAM P8)
2008
International audience; Purpose: : Neuronal tissues such as the brain and the retina contain elevated amounts of long-chain omega-3 polyunsaturated fatty acids (PUFAs) and particularly docosahexaenoic acid (DHA). DHA concentrations are known to decrease in the aging brain and are associated with cognitive decline. The senescence-accelerated mouse prone 8 (SAM P8) is a mouse model for aging that exhibits deficits in cognitive performances as well as alterations of retinal functionality (ARVO 2004 E-abstract 797). The aim of this study was to evaluate the effects of a dietary supplementation with DHA on mood, cognition and visual functionality of SAM P8 during aging. Methods: : SAM P8 mice we…
Relevance of Oxygen Concentration in Stem Cell Culture for Regenerative Medicine
2019
The key hallmark of stem cells is their ability to self-renew while keeping a differentiation potential. Intrinsic and extrinsic cell factors may contribute to a decline in these stem cell properties, and this is of the most importance when culturing them. One of these factors is oxygen concentration, which has been closely linked to the maintenance of stemness. The widely used environmental 21% O2 concentration represents a hyperoxic non-physiological condition, which can impair stem cell behaviour by many mechanisms. The goal of this review is to understand these mechanisms underlying the oxygen signalling pathways and their negatively-associated consequences. This may provide a rationale…
Telomerase activity and telomeric states in cell proliferative and differentiative mechanisms.
2008
Telomeres are DNA-protein complexes playing an important role in the maintenance of genome integrity. Telomerase is the enzyme acting as a template for addition of new telomeric repeats; this addition is essential for those cellular populations that have proliferative and differentiative potential. Telomerase and associated proteins are essential in response to DNA damage. Moreover, telomere-associated proteins as TRF2 are involved in all signalling transduction pathway which drive cellular proliferation and differentiation. In somatic cells, shortening of telomeres contributes to the onset of senescence or apoptosis; tissues which require cellular renewal express telomerase activity in ord…
B cell immunosenescence in the elderly and in centenarians.
2008
The elderly suffer from an increased susceptibility to infectious disease and cancer. Aging of the immune system contributes to this state of affairs due to immunosenescence. Because repeated intermittent or chronic antigen exposure may lead to lymphocyte clonal exhaustion, chronic antigenic stress plays a part in the compromised immunity of the elderly, who have accumulated a lifetime's exposure to infectious agents, autoantigens, and cancer antigens. Literature on immunosenescence has focused mainly on T cell impairment, but B cell compartment is also affected. The age-dependent B cell changes documented by the present review indicate that advanced age per se is a condition characterized …
The role of immune response in ageing and longevity. A focus on B cell compartment
2017
The improvement of the quality of life of elderly people is going to become a priority because of the continuous increase in the number of centenarians. This render the studies of the processes involved in ageing of critical importance. Centenarians are a widely accepted model of successful ageing, a complex process which is influenced by several biological, environmental and lifestyle factors, because they have reached the extreme limits of life span overcoming the major age-related diseases. In centenarians model, several aspects have been studied, as inflammation, immune system, genetics and metabolism, to understand the secret of their long survival. It has been proposed that centenaria…
From cellular senescence to age-associated diseases: miRNAs as tools and targets for healthy ageing
2017
miRNAs are the most abundant RNA species to be found in cell-free blood, encapsulated within microvesicles or bound to proteins. miRNAs play essential roles in the regulation of various biological processes. Moreover, specific changes in miRNA transcription levels or miRNA secretory levels have been linked to the development and progression of certain age-related diseases. So, they might be an ideal target for modulating healthy ageing
Aging and chronic inflammation: highlights from a multidisciplinary workshop
2023
Abstract: Aging is a gradual, continuous series of natural changes in biological, physiological, immunological, environmental, psychological, behavioral, and social processes. Aging entails changes in the immune system characterized by a decrease in thymic output of naïve lymphocytes, an accumulated chronic antigenic stress notably caused by chronic infections such as cytomegalovirus (CMV), and immune cell senescence with acquisition of an inflammatory senescence-associated secretory phenotype (SASP). For this reason, and due to the SASP originating from other tissues, aging is commonly accompanied by low-grade chronic inflammation, termed “inflammaging”. After decades of accumulating evide…