Search results for "SENESCENCE"
showing 10 items of 339 documents
Establishment and characterization of a nontumorigenic cell line derived from a human hepatocellular adenoma expressing hepatocyte-specific markers.
1997
In the present study the establishment and characterization of a nontumorigenic liver epithelial cell line (HACL-1) derived from a human hepatocellular adenoma is described. The HACL-1 cells have a finite life span (i.e., they proliferate for a period of 2 months and then senesce), show cell-cell contact inhibition, do not grow in soft agar, are not tumorigenic when injected in nude mice, and possess a normal diploid karyotype. The cultured cells resemble hepatocytes, but exhibit some features of dedifferentiation. At the ultrastructural level the cells are endowed with round or oval nuclei, abundant cytoplasmic organelles, and varying amounts of glycogen. The rough endoplasmic reticulum is…
Mitochondria as sources and targets of damage in cellular aging.
2011
Mitochondria are considered as the most important cellular sources and targets of free radicals. They are also a source of signalling molecules that regulate cell cycle, proliferation, and apoptosis. Denham Harman postulated the free radical theory of aging in 1956. Previously Rebecca Gershman showed that radiation toxicity could be attributed to free radical damage. Subsequently, Jaime Miquel formulated the mitochondrial free radical theory of aging. We have shown that mitochondrial size, membrane potential, inner membrane mass and peroxide production is altered inside cells in old animals. These result in an increase in the oxidative damage to mitochondrial DNA with aging that can be prev…
Vascular Senescence: A Potential Bridge Between Physiological Aging and Neurogenic Decline
2021
The adult mammalian brain contains distinct neurogenic niches harboring populations of neural stem cells (NSCs) with the capacity to sustain the generation of specific subtypes of neurons during the lifetime. However, their ability to produce new progeny declines with age. The microenvironment of these specialized niches provides multiple cellular and molecular signals that condition NSC behavior and potential. Among the different niche components, vasculature has gained increasing interest over the years due to its undeniable role in NSC regulation and its therapeutic potential for neurogenesis enhancement. NSCs are uniquely positioned to receive both locally secreted factors and adhesion-…
Expression of a vegetative-storage-protein gene from Arabidopsis is regulated by copper, senescence and ozone
2001
Emerging data suggest that the mechanisms regulating plant copper homeostasis could be implicated in stress and senescence signal transduction pathways. To gain insight into copper-modulated patterns of gene expression, copper-treated Arabidopsis thaliana (L.) Heynh. plants were analysed by mRNA differential display. The experimental conditions were selected using aggregation of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) as a molecular sensor to monitor copper-induced oxidative stress. Two copper-induced messengers encoding a vegetative storage protein (VSP2) were isolated by this technique. Both clones differed in the length of their 3'-untranslated region according to the p…
A scientific approach to anti-ageing therapies: state of the art.
2008
A lasting dream of human beings is to reverse or at least postpone ageing. During the last years, an increasing number of scientific meetings, articles, and books have been devoted to anti-ageing therapies. This subject, full of misleading, simplistic, or wrong ideas, is very popular among the general public, whose imagery has been fascinated by all possible tools to delay ageing, getting immortality. Here, we discuss anti-ageing strategies aimed not to rejuvenate but to slow ageing and delay the onset of age-related diseases. These approaches should be able to substantially slow down the ageing process, extending our productive, youthful lives.
Sodium-glucose cotransporter type 2 inhibitors prevent ponatinib-induced endothelial senescence and disfunction: A potential rescue strategy
2021
Background: Ponatinib (PON), a third-generation tyrosine kinase inhibitor (TKI), has proven cardiovascular toxicity, with no known preventing agents usable to limit such side effect. Sodium-glucose cotransporter type 2 (SGLT2) inhibitors are a new class of glucose-lowering agents, featuring favorable cardiac and vascular effects. Aims: We assessed the effects of the SGLT2 inhibitors empagliflozin (EMPA) and dapagliflozin (DAPA) on human aortic endothelial cells (HAECs) and underlying vasculo-protective mechanisms in an in vitro model of PON-induced endothelial toxicity. Methods and results: We exposed HAECs to PON or vehicle (DMSO) in the presence or absence of EMPA (100 and 500 nmol/L) or …
“Mitotic Slippage” and Extranuclear DNA in Cancer Chemoresistance: A Focus on Telomeres
2020
Mitotic slippage (MS), the incomplete mitosis that results in a doubled genome in interphase, is a typical response of TP53-mutant tumors resistant to genotoxic therapy. These polyploidized cells display premature senescence and sort the damaged DNA into the cytoplasm. In this study, we explored MS in the MDA-MB-231 cell line treated with doxorubicin (DOX). We found selective release into the cytoplasm of telomere fragments enriched in telomerase reverse transcriptase (hTERT), telomere capping protein TRF2, and DNA double-strand breaks marked by γH2AX, in association with ubiquitin-binding protein SQSTM1/p62. This occurs along with the alternative lengthening of telomeres (ALT) and DNA repa…
Systems Biology and immune aging
2014
Many alterations of innate and adaptive immunity are common in the aging population, which reflect a deterioration of the immune system, and have lead to the terms "immune aging" or "immunosenescence". Systems Biology aims to the comprehensive knowledge of the structure, dynamics, control and design that define a given biological system. Systems Biology benefits from the continuous advances in the omics sciences, based on high-throughput and high-content technologies, as well as on bioinformatic tools for data mining and integration. The Systems Biology approach is becoming gradually used to propose and to test comprehensive models of aging, both at the level of the immune system and the wh…
An Official American Thoracic Society Workshop Report: Evaluation and Management of Asthma in the Elderly.
2016
Asthma in the elderly (>65 yr old) is common and associated with higher morbidity and mortality than asthma in younger patients. The poor outcomes in this group are due, in part, to underdiagnosis and undertreatment. There are a variety of factors related to aging itself that affect the presentation of asthma in the elderly and influence diagnosis and management. Structural changes in the aging lung superimposed on structural changes due to asthma itself can worsen the disease and physiologic function. Changes in the aging immune system influence the cellular composition and function in asthmatic airways. These processes and differences from younger individuals with asthma are not well u…
Immunopathology and Immunosenescence, the Immunological Key Words of Severe COVID-19. Is There a Role for Stem Cell Transplantation?
2021
The outcomes of Coronavirus disease-2019 (COVID-19) vary depending on the age, health status and sex of an individual, ranging from asymptomatic to lethal. From an immunologic viewpoint, the final severe lung damage observed in COVID-19 should be caused by cytokine storm, driven mainly by interleukin-6 and other pro-inflammatory cytokines. However, which immunopathogenic status precedes this “cytokine storm” and why the male older population is more severely affected, are currently unanswered questions. The aging of the immune system, i.e., immunosenescence, closely associated with a low-grade inflammatory status called “inflammageing,” should play a key role. The remodeling of both innate …