scholarly journals Comparative Meta-Analysis of Transcriptomics Data during Cellular Senescence andIn VivoTissue Ageing

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Konstantinos Voutetakis ◽  
Aristotelis Chatziioannou ◽  
Efstathios S. Gonos ◽  
Ioannis P. Trougakos

Several studies have employed DNA microarrays to identify gene expression signatures that mark human ageing; yet the features underlying this complicated phenomenon remain elusive. We thus conducted a bioinformatics meta-analysis on transcriptomics data from human cell- and biopsy-based microarrays experiments studying cellular senescence orin vivotissue ageing, respectively. We report that coregulated genes in the postmitotic muscle and nervous tissues are classified into pathways involved in cancer, focal adhesion, actin cytoskeleton, MAPK signalling, and metabolism regulation. Genes that are differentially regulated during cellular senescence refer to pathways involved in neurodegeneration, focal adhesion, actin cytoskeleton, proteasome, cell cycle, DNA replication, and oxidative phosphorylation. Finally, we revealed genes and pathways (referring to cancer, Huntington’s disease, MAPK signalling, focal adhesion, actin cytoskeleton, oxidative phosphorylation, and metabolic signalling) that are coregulated during cellular senescence andin vivotissue ageing. The molecular commonalities between cellular senescence and tissue ageing are also highlighted by the fact that pathways that were overrepresented exclusively in the biopsy- or cell-based datasets are modules either of the same reference pathway (e.g., metabolism) or of closely interrelated pathways (e.g., thyroid cancer and melanoma). Our reported meta-analysis has revealed novel age-related genes, setting thus the basis for more detailed future functional studies.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dorian V. Ziegler ◽  
David Vindrieux ◽  
Delphine Goehrig ◽  
Sara Jaber ◽  
Guillaume Collin ◽  
...  

AbstractCellular senescence is induced by stresses and results in a stable proliferation arrest accompanied by a pro-inflammatory secretome. Senescent cells accumulate during aging, promoting various age-related pathologies and limiting lifespan. The endoplasmic reticulum (ER) inositol 1,4,5-trisphosphate receptor, type 2 (ITPR2) calcium-release channel and calcium fluxes from the ER to the mitochondria are drivers of senescence in human cells. Here we show that Itpr2 knockout (KO) mice display improved aging such as increased lifespan, a better response to metabolic stress, less immunosenescence, as well as less liver steatosis and fibrosis. Cellular senescence, which is known to promote these alterations, is decreased in Itpr2 KO mice and Itpr2 KO embryo-derived cells. Interestingly, ablation of ITPR2 in vivo and in vitro decreases the number of contacts between the mitochondria and the ER and their forced contacts induce premature senescence. These findings shed light on the role of contacts and facilitated exchanges between the ER and the mitochondria through ITPR2 in regulating senescence and aging.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 954
Author(s):  
Luis I. Prieto ◽  
Sara I. Graves ◽  
Darren J. Baker

Cellular senescence is the dynamic process of durable cell-cycle arrest. Senescent cells remain metabolically active and often acquire a distinctive bioactive secretory phenotype. Much of our molecular understanding in senescent cell biology comes from studies using mammalian cell lines exposed to stress or extended culture periods. While less well understood mechanistically, senescence in vivo is becoming appreciated for its numerous biological implications, both in the context of beneficial processes, such as development, tumor suppression, and wound healing, and in detrimental conditions, where senescent cell accumulation has been shown to contribute to aging and age-related diseases. Importantly, clearance of senescent cells, through either genetic or pharmacological means, has been shown to not only extend the healthspan of prematurely and naturally aged mice but also attenuate pathology in mouse models of chronic disease. These observations have prompted an investigation of how and why senescent cells accumulate with aging and have renewed exploration into the characteristics of cellular senescence in vivo. Here, we highlight our molecular understanding of the dynamics that lead to a cellular arrest and how various effectors may explain the consequences of senescence in tissues. Lastly, we discuss how exploitation of strategies to eliminate senescent cells or their effects may have clinical utility.


2021 ◽  
Vol 22 (22) ◽  
pp. 12232
Author(s):  
Nathalie Thorin-Trescases ◽  
Pauline Labbé ◽  
Pauline Mury ◽  
Mélanie Lambert ◽  
Eric Thorin

Cellular senescence is a cell fate primarily induced by DNA damage, characterized by irreversible growth arrest in an attempt to stop the damage. Senescence is a cellular response to a stressor and is observed with aging, but also during wound healing and in embryogenic developmental processes. Senescent cells are metabolically active and secrete a multitude of molecules gathered in the senescence-associated secretory phenotype (SASP). The SASP includes inflammatory cytokines, chemokines, growth factors and metalloproteinases, with autocrine and paracrine activities. Among hundreds of molecules, angiopoietin-like 2 (angptl2) is an interesting, although understudied, SASP member identified in various types of senescent cells. Angptl2 is a circulatory protein, and plasma angptl2 levels increase with age and with various chronic inflammatory diseases such as cancer, atherosclerosis, diabetes, heart failure and a multitude of age-related diseases. In this review, we will examine in which context angptl2 was identified as a SASP factor, describe the experimental evidence showing that angptl2 is a marker of senescence in vitro and in vivo, and discuss the impact of angptl2-related senescence in both physiological and pathological conditions. Future work is needed to demonstrate whether the senescence marker angptl2 is a potential clinical biomarker of age-related diseases.


2020 ◽  
Vol 12 ◽  
Author(s):  
Ai Qing Yu ◽  
Jie Wang ◽  
Xiao Jia Zhou ◽  
Ke Yu Chen ◽  
You De Cao ◽  
...  

Cellular senescence is implicated in several lines of aging-related disorders. However, the potential molecular mechanisms by which cellular senescence modulates age-related pathologies remain largely unexplored. Herein, we report that the density of sympathetic fibers (SFs) is significantly elevated in naturally aged mouse tissues and human colon adenoma tissues compared to the SFs densities in the corresponding young mouse tissues and human non-lesion colon tissues. A dorsal root ganglion (DRG)-human diploid fibroblast coculture assay revealed that senescent cells promote the outgrowth of SFs, indicating that the senescent cells induce recruitment of SFs in vitro. Additionally, subcutaneous transplantation of 2BS fibroblasts in nude mice shows that transplanted senescent 2BS fibroblasts promote SFs infiltration. Intra-articular senolytic molecular injection can reduce SFs density and inhibit SFs infiltration caused by senescent cells in osteoarthritis (OA), suggesting senescent cells promote the infiltration of SFs in vivo in aged tissues. Notably, the elevated level of SFs contributes to impaired cognitive function in naturally aged mice, which can be reversed by treatment with propranolol hydrochloride, a non-selective β receptor blocker that inhibits sympathetic nerve activity (SNA) by blocking non-selective β receptors. Additionally, 6-hydroxydopamine (6-OHDA)-induced sympathectomy improved hepatic sympathetic overactivity mediated hepatic steatosis in high fat diet (HFD)-fed APOE knockout mice (APOE−/− mice) by reducing hepatic SNA. Taken together, this study concludes that senescent cell-secreted netrin-1 mediated SFs outgrowth and infiltration, which contributes to aging-related disorders, suggesting that clearing senescent cells or inhibiting SNA is a promising therapeutic strategy for improving sympathetic nervous system (SNS) hyperactivity-induced aging-related pathologies.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Gabor Czibik

Introduction: Cardiac aging is characterized by cardiomyocyte hypertrophy and myocardial interstitial fibrosis with impaired contractility and relaxation. Recent metabolomics studies revealed an age-dependent increase in the plasma levels of essential amino acid phenylalanine (Phe), which is predictive of heart failure hospitalization. The present study aimed to dissect 1) the basis for increased Phe levels with age and 2) how Phe may promote age-related cardiac dysfunction. Methods: To establish a role for Phe in driving cardiac aging, wild-type (WT) male mice were treated twice a day with Phe (200 mg/kg) for a month. The impact of Phe on cellular senescence, redox biology and epigenetics were explored in cultured cardiomyocytes (primary adult rat and AC-16 human cardiomyocytes) treated with Phe. In vivo cardiac structure and function, together with Phe catabolism were monitored in WT and in p21 -/- mice (in pursuit of p21 induction with Phe and age) up to 24 months of age. Finally, we treated aged WT mice with tetrahydrobiopterin (BH4; 10 mg/kg), the essential cofactor for Phe-degrading enzyme phenylalanine hydroxylase (Pah). The effect of aging and Phe treatment on hepatic Phe catabolism was explored in vivo and vitro in AML-12 hepatocytes. Results: Natural aging induced a progressive increase in plasma Phe levels concomitant with cardiac dysfunction, whilst p21 deficiency prevented these changes. Phe treatment triggered cellular senescence, along with complex redox and epigenetic changes in vitro and induced an age-mimicking cardiac deterioration in young WT mice in vivo . Pharmacological restoration of Phe catabolism with BH4 reversed the rise in plasma Phe and senescent cardiac alterations in aged WT mice without affecting myocardial NOS activity. Key observations were reproduced in corresponding human samples and collectively they pointed to hepatic Phe catabolic decline with ensuing elevated plasma Phe levels compromising cardiac integrity. Conclusions: Our findings established a pathogenic role for increased Phe levels in cardiac aging, highlighting modulation of Phe catabolism as a potential therapeutic target for age-associated cardiac impairment.


2021 ◽  
Author(s):  
Irfan Rahman ◽  
Gagandeep Kaur ◽  
Isaac Sundar

Abstract Cellular senescence and lung aging are associated with the pathogenesis of Chronic Obstructive Pulmonary Disease (COPD). COPD progresses with aging, and chronic smoking is the key susceptibility factor in lung pathological changes concurrent with biological aging. However, these processes involving cigarette smoke (CS)-mediated lung cellular senescence are difficult to distinguish. One of the impediments to study cellular senescence in relation to age-related lung pathologies is the lack of a suitable in vivo model. In view of this, we provide evidence that supports the suitability of p16-3MR mice to study cellular senescence in CS-mediated and age-related lung pathologies. p16-3MR mice has a trimodal reporter fused to the promoter of p16INK4a gene that enables detection, isolation and selective elimination of senescent cells, thus making it a suitable model to study cellular senescence. To determine its suitability in CS-mediated lung pathologies, we exposed young (12-14 months) and old (17-20 months) p16-3MR mice to 30-day CS exposure and studied the expression of senescent genes (p16, p21 and p53) and SASP-associated markers (MMP9, MMP12, PAI-1, and FN-1) in air- and CS-exposed mouse lungs. Our results showed that this model could detect cellular senescence using luminescence and isolate cells undergoing senescence with the help of tissue fluorescence in CS-challenged young and old mice. Our results from the expression of senescence markers and SASP-associated genes in CS-challenged young and old p16-3MR mice were comparable with increased lung cellular senescence and SASP in COPD. We further showed age-dependent alteration in the (i) tissue luminescence and fluorescence, (ii) mRNA and protein expressions of senescent markers and SASP genes, and (iii) SA-β-gal activity in CS-challenged young and old p16-3MR mice as compared to their air controls. Overall, we showed that p16-3MR is a competent model to study cellular senescence in age-related pathologies and could help understand the pathobiology of cellular senescence in lung conditions like COPD and fibrosis.


2021 ◽  
Author(s):  
Giorgio Oliviero ◽  
Sergey Kovalchuk ◽  
Adelina Rogowska-Wrzesinska ◽  
Veit Schwämmle ◽  
Ole N. Jensen

SUMMARYTemporal molecular changes in ageing mammalian organs are of relevance to disease etiology because many age-related diseases are linked to changes in the transcriptional and epigenetic machinery that regulate gene expression. We performed quantitative proteome analysis of chromatin-enriched protein extracts to investigate the dynamics of the chromatin-proteomes of the mouse brain, heart, lung, kidney, liver, and spleen at 3, 5, 10, and 15 months of age. Each organ exhibited a distinct chromatin-proteome and sets of unique proteins. The brain and spleen chromatin-proteomes were the most extensive, diverse, and heterogenous among the six organs. The spleen chromatin proteome appeared static during the lifespan, presenting a young phenotype that reflects the permanent alertness state and important role of this organ in physiological defense and immunity. We identified a total of 5928 proteins, including 2472 nuclear or chromatin associated proteins across the six mouse organs. Up to 3125 proteins were quantified in each organ demonstrating distinct and organ-specific temporal protein expression timelines and regulation at the post-translational level. Bioinformatics meta- analysis of these chromatin proteomes revealed distinct physiological and ageing- related features for each organ. Our results demonstrate the efficiency of organelle specific proteomics for in vivo studies of a model organism and consolidate the hypothesis that chromatin-associated proteins are involved in distinct and specific physiological functions in ageing organs.HIGHLIGHTSQuantitative chromatin-proteome analysis during mouse lifespan;Chromatin analysis in vitro and in vivo mouse models;Distinct chromatin proteomes of six organs during mouse lifespan;Correlations between ageing and chromatin regulation in mammalian lifespan.


2021 ◽  
Author(s):  
Gagandeep Kaur ◽  
Isaac K. Sundar ◽  
Irfan Rahman

ABSTRACTCellular senescence and lung aging are associated with the pathogenesis of Chronic Obstructive Pulmonary Disease (COPD). COPD progresses with aging, and chronic smoking is the key susceptibility factor in lung pathological changes concurrent with biological aging. However, these processes involving cigarette smoke (CS)-mediated lung cellular senescence are difficult to distinguish. One of the impediments to study cellular senescence in relation to age-related lung pathologies is the lack of a suitable in vivo model. In view of this, we provide evidence that supports the suitability of p16-3MR mice to study cellular senescence in CS-mediated and age-related lung pathologies. p16-3MR mice has a trimodal reporter fused to the promoter of p16INK4a gene that enables detection, isolation and selective elimination of senescent cells, thus making it a suitable model to study cellular senescence. To determine its suitability in CS-mediated lung pathologies, we exposed young (12-14 months) and old (17-20 months) p16-3MR mice to 30-day CS exposure and studied the expression of senescent genes (p16, p21 and p53) and SASP-associated markers (MMP9, MMP12, PAI-1, and FN-1) in air- and CS-exposed mouse lungs. Our results showed that this model could detect cellular senescence using luminescence and isolate cells undergoing senescence with the help of tissue fluorescence in CS-challenged young and old mice. Our results from the expression of senescence markers and SASP-associated genes in CS-challenged young and old p16-3MR mice were comparable with increased lung cellular senescence and SASP in COPD. We further showed age-dependent alteration in the (i) tissue luminescence and fluorescence, (ii) mRNA and protein expressions of senescent markers and SASP genes, and (iii) SA-β-gal activity in CS-challenged young and old p16-3MR mice as compared to their air controls. Overall, we showed that p16-3MR is a competent model to study cellular senescence in age-related pathologies and could help understand the pathobiology of cellular senescence in lung conditions like COPD and fibrosis.


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