Search results for "SENESCENCE"
showing 10 items of 339 documents
A Perspective on Aging in Rotifers
1980
Most research on aging in rotifers has been performed with populations, not with individuals. As a consequence, the dependent variable in these studies is usually either mean lifespan or rate of survivorship. After a brief consideration of the literature published since the last major review (King, 1969), the results of a series of experiments are presented. Males and females of three genetically distinct clones of Brachionus plicatilis were used for a factorial life table analysis at three different temperatures. The results of these experiments indicate several potential problems in using populations to study the aging process of individuals. These problems derive from the fact that lifes…
BCL-xL, a Mitochondrial Protein Involved in Successful Aging: From C. elegans to Human Centenarians
2020
B-Cell Lymphoma-extra-large (BCL-xL) is involved in longevity and successful aging, which indicates a role for BCL-xL in cell survival pathway regulation. Beyond its well described role as an inhibitor of apoptosis by preventing cytochrome c release, BCL-xL has also been related, indirectly, to autophagy and senescence pathways. Although in these latter cases, BCL-xL has dual roles, either activating or inhibiting, depending on the cell type and the specific conditions. Taken together, all these findings suggest a precise mechanism of action for BCL-xL, able to regulate the crosstalk between apoptosis, autophagy, and senescence, thus promoting cell survival or cell death. All three pathways…
Histone Variant MacroH2A1 Marks Liver Aging and Orchestrates the Escape from Senescence Induced by DNA Hypomethylation in Hepatocellular Carcinoma
2015
The epigenetic basis of age-associated progression of liver diseases towards hepatocellular carcinoma (HCC) is unclear. MacroH2A1 is a variant of histone H2A1, present in the two isoforms, with fundamental roles in cell homeostasis. MacroH2A1 is a marker of senescence associated heterochromatic foci (SAHF) and synergizes with DNA demethylating chemotherapic agent 5-aza-2'-deoxycytidine (5-aza-dC) in silencing tumor suppressor genes in human fibroblasts. We show that protein levels of macroH2A1 isoforms are increased in the livers of old rodents and humans, and in human HCC tissue. Human HCC cells overexpressing macroH2A1 escape a 5-aza-dC-induced senescent phenotype, as determined by cell p…
Chaperonopathies of senescence and the scrambling of interactions between the chaperoning and the immune systems
2010
Aging entails progressive deterioration of molecules and supramolecular structures, including Hsp chaperones and their complexes, paralleled by functional decline. Recent research has changed our views on Hsp chaperones. They work inside and outside cells in many locations, alone or forming teams, interacting with cells, receptors, and molecules that are not chaperones, in roles that are not typically attributed to chaperones, such as protein folding. Hsp chaperones form a physiological system with a variety of functions and interactions with other systems, for example, the immune system. We propose that chaperone malfunctioning due to structural damage or gene dysregulation during aging ha…
Hsp60 and Hsp10 in Ageing
2009
HSP and molecular chaperones, both referred to in this chapter as chaperones, are key players in development and senescence. With regard to senescence, several issues are critical: the role of normal chaperones in the process of ageing itself and in preventing and controlling age-associated diseases, the role of defective chaperones (chaperonopathies) in the onset and progression of senescence and in the etiology of old-age diseases, the interaction of chaperones with the immune system, and the potential of chaperones as therapeutic agents for counteracting the deleterious effects of ageing on molecules and cells and for treating proteinopathies of the elderly (chaperonotherapy). All these …
Chemical intervention in senescence-accelerated mice metabolism for modeling neurodegenerative diseases: an overview
2004
Abstract SAMP1 is a line of inbred mice with a pronounced misbalance between generation and neutralization of reactive oxygen species (ROS) in brain and other tissues. This results in accumulation of molecular defects in lipids, proteins and DNA moieties. The metabolic disorders appear at a very early stage of ontogenic development and induce morphological and behavioral defects manifesting from the fourth month after birth. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment of these mice induced specific changes that closely resembled parkinsonian syndrome. Neuropeptide carnosine prevented toxic effects of MPTP and protected the animals against experimental parkinsonism.
Is chlamydial heat shock protein 60 a risk factor for oncogenesis?
2004
Heat shock protein 60 (HSP60) plays an important role in the protein folding of prokaryotic and eukaryotic cells. Most of the papers published on chlamydial HSP60 concern its role in immune response during infection. In the last decade, exposure to Chlamydia trachomatis has been consistently associated with the development of cervical and ovarian cancer. Moreover, it has been suggested that chlamydial HSP60 may have an anti- apoptotic effect during persistent infection. We hypothesize that the accumulation of exogenous chlamydial HSP60 in the cytoplasm of actively replicating eukaryotic cells may interfere with the regulation of the apoptotic pathway. The concomitant expression of viral onc…
Age-related changes in astrocytic and ependymal cells of the subventricular zone
2014
Neurogenesis persists in the adult subventricular zone (SVZ) of the mammalian brain. During aging, the SVZ neurogenic capacity undergoes a progressive decline, which is attributed to a decrease in the population of neural stem cells (NSCs). However, the behavior of the NSCs that remain in the aged brain is not fully understood. Here we performed a comparative ultrastructural study of the SVZ niche of 2-month-old and 24-month-old male C57BL/6 mice, focusing on the NSC population. Using thymidine-labeling, we showed that residual NSCs in the aged SVZ divide less frequently than those in young mice. We also provided evidence that ependymal cells are not newly generated during senescence, as ot…
Rejuvenative Efficacy and NF-κB Pathway-Dependent Mechanism of Human Platelet Lysate on Skin Aging
2021
Background: Skin aging is an irreversible process associated with poor self-regenerative capability. Human platelet lysate (hPL) contains rich amounts of growth factors, benefiting tissue regeneration. To explore the anti-aging efficacy and mechanism of hPL on skin, this study employed nude mice and human dermal fibroblasts (HDFs) to perform in vitro and in vivo assays. Methods: Flow cytometry and ELISA were conducted for quality control of hPL. In vivo, skin texture grading, histopathological observation, immunofluorescence analysis, and SOD and MDA assays were conducted to determine the effects of hPL on epidermis and dermis of aged skin. In vitro, senescence-associated-beta-galactosidase…
Interleukin 13 (IL-13)-regulated expression of the chondroprotective metalloproteinase ADAM15 is reduced in aging cartilage
2020
Objective The adamalysin metalloproteinase 15 (ADAM15) has been shown to protect against development of osteoarthritis in mice. Here, we have investigated factors that control ADAM15 levels in cartilage. Design Secretomes from wild-type and Adam15−/− chondrocytes were compared by label-free quantitative mass spectrometry. mRNA was isolated from murine knee joints, either with or without surgical induction of osteoarthritis on male C57BL/6 mice, and the expression of Adam15 and other related genes quantified by RT-qPCR. ADAM15 in human normal and osteoarthritic cartilage was investigated similarly and by fluorescent immunohistochemistry. Cultured HTB94 chondrosarcoma cells were treated with …