Search results for "cellular senescence"
showing 10 items of 109 documents
Mcl-1 targeting could be an intriguing perspective to cure cancer
2018
The Bcl-2 family, which plays important roles in controlling cancer development, is divided into antiapoptotic and proapoptotic members. The change in the balance between these members governs the life and death of the cells. Mcl-1 is an antiapoptotic member of this family and its distribution in normal and cancerous tissues strongly differs from that of Bcl-2. In human cancers, where upregulation of antiapoptotic proteins is common, Mcl-1 expression is regulated independent of Bcl-2 and its inhibition promotes senescence, a major barrier to tumorigenesis. Cancer chemotherapy determines various kinds of responses, such as senescence and autophagy; however, the ideal response to chemotherapy…
Class I histone deacetylases regulate p53/NF-κB crosstalk in cancer cells
2016
The transcription factors NF-κB and p53 as well as their crosstalk determine the fate of tumor cells upon therapeutic interventions. Replicative stress and cytokines promote signaling cascades that lead to the co-regulation of p53 and NF-κB. Consequently, nuclear p53/NF-κB signaling complexes activate NF-κB-dependent survival genes. The 18 histone deacetylases (HDACs) are epigenetic modulators that fall into four classes (I-IV). Inhibitors of histone deacetylases (HDACi) become increasingly appreciated as anti-cancer agents. Based on their effects on p53 and NF-κB, we addressed whether clinically relevant HDACi affect the NF-κB/p53 crosstalk. The chemotherapeutics hydroxyurea, etoposide, an…
DNA Hypomethylation and Histone Variant macroH2A1 Synergistically Attenuate Chemotherapy-Induced Senescence to Promote Hepatocellular Carcinoma Progr…
2016
Abstract Aging is a major risk factor for progression of liver diseases to hepatocellular carcinoma (HCC). Cellular senescence contributes to age-related tissue dysfunction, but the epigenetic basis underlying drug-induced senescence remains unclear. macroH2A1, a variant of histone H2A, is a marker of senescence-associated heterochromatic foci that synergizes with DNA methylation to silence tumor-suppressor genes in human fibroblasts. In this study, we investigated the relationship between macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, and liver carcinogenesis. We found that protein levels of both macroH2A1 isoforms were increased in the livers of very elderly rodents and humans, a…
A dual role of caspase-8 in triggering and sensing proliferation-associated DNA damage, a key determinant of liver cancer development.
2017
Summary Concomitant hepatocyte apoptosis and regeneration is a hallmark of chronic liver diseases (CLDs) predisposing to hepatocellular carcinoma (HCC). Here, we mechanistically link caspase-8-dependent apoptosis to HCC development via proliferation- and replication-associated DNA damage. Proliferation-associated replication stress, DNA damage, and genetic instability are detectable in CLDs before any neoplastic changes occur. Accumulated levels of hepatocyte apoptosis determine and predict subsequent hepatocarcinogenesis. Proliferation-associated DNA damage is sensed by a complex comprising caspase-8, FADD, c-FLIP, and a kinase-dependent function of RIPK1. This platform requires a non-apop…
Inhibition of DNA damage response at telomeres improves the detrimental phenotypes of Hutchinson–Gilford Progeria Syndrome
2019
Hutchinson–Gilford progeria syndrome (HGPS) is a genetic disorder characterized by premature aging features. Cells from HGPS patients express progerin, a truncated form of Lamin A, which perturbs cellular homeostasis leading to nuclear shape alterations, genome instability, heterochromatin loss, telomere dysfunction and premature entry into cellular senescence. Recently, we reported that telomere dysfunction induces the transcription of telomeric non-coding RNAs (tncRNAs) which control the DNA damage response (DDR) at dysfunctional telomeres. Here we show that progerin-induced telomere dysfunction induces the transcription of tncRNAs. Their functional inhibition by sequence-specific telomer…
MUC4 is overexpressed in idiopathic pulmonary fibrosis and collaborates with transforming growth factor β inducing fibrotic responses.
2021
Several mucins are implicated in idiopathic pulmonary fibrosis (IPF); however, there is no evidence regarding the role of MUC4 in the development of IPF. Here we demonstrated that MUC4 was overexpressed in IPF patients (n = 22) compared with healthy subjects (n = 21) and located in pulmonary arteries, bronchial epithelial cells, fibroblasts, and hyperplastic alveolar type II cells. Decreased expression of MUC4 using siRNA–MUC4 inhibited the mesenchymal/myofibroblast transformations of alveolar type II A549 cells and lung fibroblasts, as well as cell senescence and fibroblast proliferation induced by TGF-β1. The induction of the overexpression of MUC4 increased the effects of TGF-β1 on mesen…
p38α regulates actin cytoskeleton and cytokinesis in hepatocytes during development and aging.
2017
[Background]: Hepatocyte poliploidization is an age-dependent process, being cytokinesis failure the main mechanism of polyploid hepatocyte formation. Our aim was to study the role of p38α MAPK in the regulation of actin cytoskeleton and cytokinesis in hepatocytes during development and aging. [Methods]: Wild type and p38α liver-specific knock out mice at different ages (after weaning, adults and old) were used. [Results]: We show that p38α MAPK deficiency induces actin disassembly upon aging and also cytokinesis failure leading to enhanced binucleation. Although the steady state levels of cyclin D1 in wild type and p38α knock out old livers remained unaffected, cyclin B1- a marker for G2/M…
Synaptic Regulator α-Synuclein in Dopaminergic Fibers Is Essentially Required for the Maintenance of Subependymal Neural Stem Cells.
2018
Synaptic protein -synuclein (-SYN) modulates neurotransmission in a complex and poorly understood manner and aggregates in the cytoplasm of degenerating neurons in Parkinsons disease. Here, we report that -SYN present in dopaminergic nigral afferents is essential for the normal cycling and maintenance of neural stem cells (NSCs) in the brain subependymal zone of adult male and female mice. We also showthat premature senescence of adult NSCs into non-neurogenic astrocytes in mice lacking-SYN resemblesthe effects of dopaminergic fiber degeneration resulting from chronic exposure to 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine or intranigral inoculation of aggregated toxic -SYN. Interestingly…
Two different pathogenic mechanisms, dying-back axonal neuropathy and pancreatic senescence, are present in the YG8R mouse model of Friedreich ataxia
2016
Frataxin (FXN) deficiency causes Friedreich's ataxia (FRDA), a multisystem disorder with neurological and non-neurological symptoms. FRDA pathophysiology combines developmental and degenerative processes of dorsal root ganglia (DRG), sensory nerves, dorsal columns and other central nervous structures. A dying-back mechanism has been proposed to explain the peripheral neuropathy and neuropathology. In addition, affected individuals have non-neuronal symptoms such as diabetes mellitus or glucose intolerance. To go further in the understanding of the pathogenic mechanisms of neuropathy and diabetes associated with the disease, we have investigated the humanized mouse YG8R model of FRDA. By bio…
p53 and p53-related mediators PAI-1 and IGFBP-3 are downregulated in peripheral blood mononuclear cells of HIV-patients exposed to non-nucleoside rev…
2019
The improved effectiveness and safety of the combined antiretroviral therapy (cART) has largely diminished mortality and AIDS-defining morbidity of HIV-patients. Nevertheless, chronic age-related diseases in these individuals are more common and their underlying pathogenic mechanisms of these actions seem to involve accelerated aging and enhanced inflammation. The present study explores markers of these processes in a heterogenous Spanish HIV cohort using peripheral blood samples of HIV-patients and matched uninfected controls. We isolated periheral blood mononuclear cells (PBMCs) and i) compared the expression of a panel of 14 genes related to inflammation and senescence in PBMCs of HIV-pa…