A Dual Role of the Senescence Marker P16Ink4a in Liver Endothelial Cell Function
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PROVIDER: PRJNA1185188 | ENA |
REPOSITORIES: ENA
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Project description:P16Ink4a is a well-established marker of senescence. Although P16Ink4a is expressed in endothelial cells, little is known about its function in these cells. Using isolated liver endothelial cells with silencing or overexpression of P16Ink4a, we show here that dependent on P16Ink4a levels, different pathways and functions are affected. High levels of P16Ink4a reduce proliferation and induce senescence while low levels have the opposite effects. Only high P16Ink4a expression reduces in vitro angiogenesis. Expression profiling reveals an inflammatory phenotype upon silencing of P16Ink4a while P16Ink4a overexpression is associated with a profile associated to DNA damage, repair and senescence. Low levels of P16Ink4a induce reactive oxygen species (ROS) generation and increase endothelial cell leakage. Collectively, P16Ink4a represents an “antagonistic pleiotropy” gene, which is on the one hand required to prevent ROS generation and endothelial damage and on the other hand at high levels inhibits angiogenesis through induction of senescence.
2024-11-18 | GSE281665 | GEO
Project description:Uncontrolled accumulation of pulmonary artery smooth muscle cells (PASMC) to the distal pulmonary arterioles (PAs) is one of the major characteristics of pulmonary hypertension (PH). Cellular senescence contributes to aging and lung diseases associated with PH and links to PH progression. However, the mechanism by which cellular senescence controls vascular remodeling in PH is not fully understood. The levels of senescence marker, p16INK4A and senescence-associated β-galactosidase (SA-β-gal) activity are higher in PA endothelial cells (ECs) isolated from idiopathic pulmonary arterial hypertension (IPAH) patients compared to those from healthy individuals. Hypoxia-induced accumulation of α-smooth muscle actin (αSMA)-positive cells to the PAs is attenuated in p16fl/fl-Cdh5(PAC)-CreERT2 (p16iΔEC) mice after tamoxifen induction. We have reported that endothelial TWIST1 mediates hypoxia-induced vascular remodeling by increasing platelet-derived growth factor (PDGFB) expression. Transcriptomic analyses of IPAH patient or hypoxia-induced mouse lung ECs reveal the alteration of senescence-related gene expression and their interaction with TWIST1. Knockdown of p16INK4A attenuates the expression of PDGFB and TWIST1 in IPAH patient PAECs or hypoxia-treated mouse lungs and suppresses accumulation of αSMA–positive cells to the supplemented ECs in the gel implanted on the mouse lungs. Hypoxia-treated mouse lung EC-derived exosomes stimulate DNA synthesis and migration of PASMCs in vitro and in the gel implanted on the mouse lungs, while p16iΔEC mouse lung EC-derived exosomes inhibit the effects. These results suggest that endothelial senescence controls αSMA–positive cell proliferation and migration in PH through TWIST1-PDGFB signaling.
2022-10-15 | PXD033549 | Pride
Project description:Accumulation of senescent cells with age is believed to be an important driver of aging and age-related diseases. However, the underlying mechanisms and the signaling pathways that regulate senescence remain elusive. In this report, we couple high throughput (HTP) mapping of disease-associated functional SNPs (fSNPs) with proteomics analysis of fSNP-binding regulatory proteins to dissect the CDKN2A/B locus, a locus known to be associated with multiple age-related diseases, as well as overall human longevity. We demonstrate that the homeodomain transcription factor CUX1 specifically binds to a fSNP (rs1537371) associated with atherosclerosis within the CDKN2A/B locus. Although it binds at a considerable distance (> 100 kb), CUX1 is shown to regulate the CDKN2A/B encoded genes p14ARF, p15INK4b, p16INK4a, and ANRIL in endothelial cells (ECs). In-depth analysis demonstrates that endothelial CUX1 expression correlates with telomeric length and is induced by both DNA-damaging agents and oxidative stress. Moreover, induction of CUX1 expression triggers both replicative and stress-induced premature senescence via activating p16INK4A expression. Consistent with these findings, we also detect elevated expression of CUX1 and p16INK4A in the plaques of patients with carotid artery disease. Our HTP strategy therefore identifies CUX1 as a regulator of p16INK4A expression and endothelial senescence and a potential therapeutic target for atherosclerosis and other age-related diseases.
2021-12-05 | GSE186528 | GEO
Project description:Cellular senescence plays a causal role in ageing and, in mouse, depletion of p16INK4a-expressing senescent cells delays ageing-associated disorders. Adenosine deaminases acting on RNA (ADARs) RNA editing enzymes are also implicated as important regulators of human ageing and ADAR inactivation causes age-associated pathologies such as neurodegeneration in model organisms. However, the role, if any, of ADARs in cellular senescence is unknown. Here we show that ADAR1 is post-transcriptionally downregulated by autophagic degradation to promote senescence through upregulating p16INK4a. ADAR1 is downregulated during senescence post-transcriptionally by autophagy-lysosomal pathway and the downregulation is sufficient to drive senescence in both in vitro and in vivo models. Senescence induced by ADAR1 downregulation is p16INK4a dependent and independent of its RNA editing function. Mechanistically, ADAR1 promotes SIRT1 expression by affecting its RNA stability through HuR, an RNA binding protein that increases the half-life and steady state levels of its target mRNAs. And SIRT1, in turn, antagonizes translation of mRNA encoding p16INK4a. Hence, downregulation of ADAR1 and SIRT1 mediates p16INK4aupregulation by enhancing its mRNA translation. Finally, Adar1 is downregulated during ageing of mouse tissues such as brain, ovary, and intestine, and Adar1 expression correlates with Sirt1 expression in these tissues in mice. Together, our study reveals an RNA-editing independent role of ADAR1 in regulating senescence by post-transcriptionally controlling p16INK4a expression.
2022-04-25 | GSE179423 | GEO
Project description:Uncontrolled accumulation of pulmonary artery smooth muscle cells (PASMC) to the non-muscularized distal pulmonary arterioles (PAs) is one of the major characteristics of pulmonary hypertension (PH). Cellular senescence contributes to aging and lung diseases associated with PH and links to PH progression. However, the mechanism by which cellular senescence controls vascular remodeling in PH is not fully understood. Here, we have demonstrated that endothelial senescence mediates PH pathology by increasing platelet-derived growth factor (PDGFB) expression. The levels of senescence markers p16INK4A and senescence-associated β-galactosidase (SA-β-gal) are higher in PA endothelial cells (ECs) isolated from IPAH patients compared to those from healthy individuals. Hypoxia-induced accumulation of α-smooth muscle actin (αSMA)-positive cells to the PAs is attenuated in p16INK4Afl/fl-Cdh5(PAC)-CreERT2 mice after tamoxifen induction. We have reported that endothelial TWIST1 mediates hypoxia-induced vascular remodeling by increasing PDGFB expression. Transcriptomic analyses of idiopathic pulmonary arterial hypertension (IPAH) patient lung ECs or hypoxia-induced mouse lung ECs reveal the alteration of senescence-related gene expression and interaction with TWIST1. Increases in the levels of PDGFB and TWIST1 in hypoxia-treated mouse lung ECs or IPAH patient lung ECs are attenuated by knocking down p16INK4A expression or treating with senolytic reagents. Knockdown of p16INK4A also suppresses accumulation of αSMA–positive cells to the supplemented ECs in the gel. Exosomes collected from hypoxia-treated mouse lung ECs stimulate SMC DNA synthesis and migration in vitro and in the gel implanted on the mouse lungs, while p16INK4A knockdown in ECs inhibits the effects. These results suggest that endothelial senescence controls αSMA–positive cell proliferation and migration in PH through TWIST1-PDGFB signaling.
2022-10-12 | GSE193272 | GEO
Project description:We collected freshly sorted mesenchyme (live CD45-Epcam-CD31-PDGFRa+GFP- or GFP+) from dissociated lung tissue of INKBRITE animals to characterize the transcriptome difference between p16INK4a+ vs p16INK4a- cells at homeostasis and during injury. We used fluorescence activated cell sorting (FACS) to exclude immune (CD45+), epithelial (Epcam+), and endothelial (CD31+) cells and positively select for PDGFRa+ mesenchyme. Cells were sequenced at a depth of average of 45 million reads/sample. The results revealed an increase of senescence associated secretory phenotype (SASP) signature in p16INK4+ cells that becomes refined after injury. We found the expression of an epithelial growth factor epiregulin (ereg) increased in p16INK4a+ cells after injury suggesting a possible role of p16INK4a+ senescence during regeneration of lung epithelium.
2022-11-02 | GSE140654 | GEO
Project description:Here we evaluated the contribution of cellular senescence to the effect of chronic exposure to low dose angiotensin II in a mouse model that mimics the initiation of hypertension. We utilized the INK-ATTAC (p16ink4a - Apoptosis Through Targeted Activation of Caspase 8) mouse model that allows for conditional elimination of p16ink4a -dependent senescent cells by administration of AP20187. INK-ATTAC mice received continuous low doses of angiotensin II over 3 weeks and AP20187 vs vehicle. In the kidneys increased expression of ATM, p15 and p21 matched with angiotensin II induction of senescence-associated secretory phenotype genes MMP3, FGF2, IGFBP2, and tPA. AP20187-mediated elimination of p16-dependent senescent cells prevented physiologic, cellular and molecular responses to angiotensin II. We conclude that angiotensin II induces a relatively selective senescence transformation of renal endothelial cells that could provide a novel therapeutic target for senolytic drugs as alternative treatment options for hypertension and resulting tissue damage.
2022-01-10 | GSE179195 | GEO
Project description:p16INK4A inhibits the CDK4/6 kinases and is therefore an important cell cycle regulator. Accumulation of p16INK4A in response to oncogenic transformation leads to cellular senescence and it is therefore frequently lost in cancer. p16INK4A is also known to accumulate under conditions of cellular oxidative stress and therefore could potentially be regulated by redox signaling, which is a form of signal transduction that is mediated by the reversible oxidation of cysteine-thiol side chains in proteins. We found that oxidation of the single cysteine residue in p16INK4A in human cells occurs under relatively mild oxidizing conditions and that this leads to disulfide dependent dimerization. p16INK4A is a well-characterized all alpha-helical protein, but we find that upon cysteine-dependent dimerization, p16INK4A undergoes a dramatic structural rearrangement and forms aggregates that have the typical features of amyloid fibrils, including binding of diagnostic dyes, presence of cross-β sheet structure, and typical dimensions found in electron microscopy. We find that p16INK4A amyloid formation abolishes its function as a CDK4/6 inhibitor in human cells. Taken together, these observations mechanistically link the cellular redox state to the inactivation of p16INK4A through the formation of amyloid fibrils.
2019-09-04 | PXD012353 | Pride
Project description:Senescence-induced endothelial phenotypes underpin immune-mediated senescence surveillance
| PRJNA801491 | ENA
Project description:ADAR1 downregulation contributes to p16INK4a upregulation independent of RNA editing during senescence
| PRJNA743669 | ENA