scholarly journals KDM4 Orchestrates Epigenomic Remodeling of Senescent Cells and Potentiates the Senescence-Associated Secretory Phenotype

2020 ◽  
Author(s):  
Boyi Zhang ◽  
Qilai Long ◽  
Shanshan Wu ◽  
Shuling Song ◽  
Qixia Xu ◽  
...  

Abstract Cellular senescence restrains the expansion of neoplastic cells through several layers of regulation, including epigenetic decoration of chromatin structure and functional modulation of bioactive components. Here we report that expression of the histone H3-specific demethylase KDM4 is upregulated in human stromal cells upon cellular senescence. In clinical oncology, upregulated KDM4 and diminished H3K9/H3K36 methylation are correlated with adverse survival of cancer patients post-chemotherapy. Global chromatin accessibility mapping via ATAC-seq and expression profiling through RNA-seq reveal extensive reorganization of chromosomes and spatiotemporal reprogramming of the transcriptomic landscape, events responsible for development of the senescence-associated secretory phenotype (SASP). Selectively targeting KDM4 dampens the SASP of senescent stromal cells and enhances the apoptotic index of cancer cells in the treatment-damaged tumor microenvironment (TME), together prolonging overall survival of experimental animals. Our study supports the dynamic change of H3K9/H3K36 methylation marks during cellular senescence, identifies an unusually permissive chromatin state, unmasks KDM4 as a key modulator of the SASP, and presents a novel therapeutic avenue to manipulate cellular senescence and curtail age-related pathologies.

Author(s):  
Boyi Zhang ◽  
Qilai Long ◽  
Shanshan Wu ◽  
Shuling Song ◽  
Qixia Xu ◽  
...  

AbstractCellular senescence restrains the expansion of neoplastic cells through several layers of regulation, including epigenetic decoration of chromatin structure and functional modulation of bioactive components. Here we report that expression of the histone H3-specific demethylase KDM4 is upregulated in human stromal cells upon cellular senescence. In clinical oncology, upregulated KDM4 and diminished H3K9/H3K36 methylation are correlated with adverse survival of cancer patients post-chemotherapy. Global chromatin accessibility mapping via ATAC-seq and expression profiling through RNA-seq reveal extensive reorganization of chromosomes and spatiotemporal reprogramming of the transcriptomic landscape, events responsible for development of the senescence-associated secretory phenotype (SASP). Selectively targeting KDM4 dampens the SASP of senescent stromal cells and enhances the apoptotic index of cancer cells in the treatment-damaged tumor microenvironment (TME), together prolonging overall survival of experimental animals. Our study supports the dynamic change of H3K9/H3K36 methylation marks during cellular senescence, identifies an unusually permissive chromatin state, unmasks KDM4 as a key modulator of the SASP, and presents a novel therapeutic avenue to manipulate cellular senescence and curtail age-related pathologies.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 742-742
Author(s):  
Judith Campisi

Abstract Cellular senescence is a complex cell fate, often induced by stress or damage, that can be beneficial or deleterious, depending on the physiological context and age of the organism. A prominent feature of senescent cells is a multi-faceted senescence-associated secretory phenotype (SASP), which includes growth factors, cytokine and chemokines, growth factors, proteases, bioactive lipids and metabolites. Senescent cells increase with age in most, if not all, mammalian tissues. Through the use of transgenic mouse models, senescent cells are now known to causally drive numerous age-related pathologies, largely through the SASP. Eliminating senescent cells, genetically or through the use of senolytic/senomorphic agents, can improve the health span, at least in mice, and hold promise for extension to humans in the near future.


Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1145
Author(s):  
Nesrine Mabrouk ◽  
Silvia Ghione ◽  
Véronique Laurens ◽  
Stéphanie Plenchette ◽  
Ali Bettaieb ◽  
...  

Cellular senescence is a cell state involved in both physiological and pathological processes such as age-related diseases and cancer. While the mechanism of senescence is now well known, its role in tumorigenesis still remains very controversial. The positive and negative effects of senescence on tumorigenesis depend largely on the diversity of the senescent phenotypes and, more precisely, on the senescence-associated secretory phenotype (SASP). In this review, we discuss the modulatory effect of nitric oxide (NO) in SASP and the possible benefits of the use of NO donors or iNOS inducers in combination with senotherapy in cancer treatment.


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.


2020 ◽  
Vol 13 ◽  
Author(s):  
Valeriia Rodichkina ◽  
Igor Kvetnoy ◽  
Victoria Polyakova ◽  
Alexander Arutjunyan ◽  
Ruslan Nasyrov ◽  
...  

: Aging is a complex biological process, a major aspect of which is the accumulation of somatic changes throughout the life. Cellular senescence is a condition in which cells undergo an irreversible cell cycle arrest in response to various cellular stresses. Once the cells begin to senesce, they become more resistant to any mutagens, including oncogenic factors. Inflammaging (inflammatory aging) is an age-related, chronic and systemic inflammatory condition realized by cells with the senescence associated secretory phenotype (SASP). These recently recognized senescent phenotypes associated with aging have been reported to promote better wound healing, embryonic development, as well as stimulation and extension of the tumor process. It is assumed that cellular senescence contributes to age-related decline of reproductive function due to the association of senescent cells with aging and age-related diseases. Thus, SASPs have both positive and negative effects, depending on the biological context. SASP cell accumulation in tissues contributes to an age-related functional decline of the tissue and organ state. In this review, the term “cellular senescence” is used to refer the processes of cells irreversible growth inhibition during their viable state, while the term “aging” is used to indicate the deterioration of tissues due to loss of function. Late reproductive age is associated with infertility and possible complications of the onset and maintenance of pregnancy. Senescent cells express pro-inflammatory cytokines, growth factors, and matrix metalloproteinases and some other molecules, collectively called the senescence associated secretory phenotype (SASP).


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Theres Schaub ◽  
Dennis Gürgen ◽  
Deborah Maus ◽  
Claudia Lange ◽  
Victor Tarabykin ◽  
...  

AbstractVascular regeneration depends on intact function of progenitors of vascular smooth muscle cells such as pericytes and their circulating counterparts, mesenchymal stromal cells (MSC). Deregulated MSC differentiation and maladaptive cell fate programs associated with age and metabolic diseases may exacerbate arteriosclerosis due to excessive transformation to osteoblast-like calcifying cells. Targeting mTOR, a central controller of differentiation and cell fates, could offer novel therapeutic perspectives. In a cell culture model for osteoblastic differentiation of pluripotent human MSC we found distinct roles for mTORC1 and mTORC2 in the regulation of differentiation towards calcifying osteoblasts via cell fate programs in a temporally-controlled sequence. Activation of mTORC1 with induction of cellular senescence and apoptosis were hallmarks of transition to a calcifying phenotype. Inhibition of mTORC1 with Rapamycin elicited reciprocal activation of mTORC2, enhanced autophagy and recruited anti-apoptotic signals, conferring protection from calcification. Pharmacologic and genetic negative interference with mTORC2 function or autophagy both abolished regenerative programs but induced cellular senescence, apoptosis, and calcification. Overexpression of the mTORC2 constituent rictor revealed that enhanced mTORC2 signaling without altered mTORC1 function was sufficient to inhibit calcification. Studies in mice reproduced the in vitro effects of mTOR modulation with Rapamycin on cell fates in vascular cells in vivo. Amplification of mTORC2 signaling promotes protective cell fates including autophagy to counteract osteoblast differentiation and calcification of MSC, representing a novel mTORC2 function. Regenerative approaches aimed at modulating mTOR network activation patterns hold promise for delaying age-related vascular diseases and treatment of accelerated arteriosclerosis in chronic metabolic conditions.


2021 ◽  
Vol 22 (7) ◽  
pp. 3553
Author(s):  
Abhishek Chandra ◽  
Jyotika Rajawat

Bone is a dynamic organ maintained by tightly regulated mechanisms. With old age, bone homeostasis, which is maintained by an intricate balance between bone formation and bone resorption, undergoes deregulation. Oxidative stress-induced DNA damage, cellular apoptosis, and cellular senescence are all responsible for this tissue dysfunction and the imbalance in the bone homeostasis. These cellular mechanisms have become a target for therapeutics to treat age-related osteoporosis. Genetic mouse models have shown the importance of senescent cell clearance in alleviating age-related osteoporosis. Furthermore, we and others have shown that targeting cellular senescence pharmacologically was an effective tool to alleviate age- and radiation-induced osteoporosis. Senescent cells also have an altered secretome known as the senescence associated secretory phenotype (SASP), which may have autocrine, paracrine, or endocrine function. The current review discusses the current and potential pathways which lead to a senescence profile in an aged skeleton and how bone homeostasis is affected during age-related osteoporosis. The review has also discussed existing therapeutics for the treatment of osteoporosis and rationalizes for novel therapeutic options based on cellular senescence and the SASP as an underlying pathogenesis of an aging bone.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4230-4230 ◽  
Author(s):  
Monika Hruba ◽  
Jitka Vesela ◽  
Hana Votavova ◽  
Michaela Dostalova Merkerova ◽  
David Kundrat ◽  
...  

Background and Aims A part of lower-risk myelodysplastic (LR-MDS) patients progress to higher-risk MDS or acute myeloid leukemia (AML). The progression may be predicted in some of these patients by determining mutations associated with myeloid malignancies at the time of diagnosis. We focused to find out dysregulated pathways caused by a well-defined mutation associated with disease progression. Methods We examined 158 samples from LR-MDS patients at diagnosis using TruSight Myeloid Sequencing Panel containing 54 genes (Illumina) to identify the mutational profile. We applied RNA-seq (NEB; Illumina) on bone marrow CD34+ cells of 5 LR-MDS patients with RUNX1 mutation and 6 LR-MDS patients without mutations. We performed differential gene expression analysis, gene set enrichment analysis (GSEA), Reactome biological pathway and Gene Ontology (GO) annotations. Results Forty out of 158 patients (25%) progressed during the follow-up period (median: 45.1 months). Mutation in RUNX1 gene was detected in 10 patients. Using RNA-seq, significantly dysregulated expression was observed in 986 genes (FDR<0.05; FC >2). Patients with mutation in RUNX1 gene had significant down regulation of expression genes involved in cellular senescence induced by DNA Damage/Telomere Stress (FDR=1.4e-11) and Oxidative Stress (FDR=3.6e-9), HDACs deacetylate histones (FDR =1.1e-13) and Senescence Associated Secretory Phenotype (FDR=1.4e-11) according to Reactome pathway database. There were 21 genes involved in the regulation of these pathways, of which 10 were part of all described pathways and belonged to the Nucleosome Assembly according to GO biological process with 33 down regulated genes (FDR=6.3e-28). According to GSEA, GO chromatin silencing gene set (Figure 1) was down regulated in the patients with RUNX1 mutation (p<0.001; NES=-1.8) same as Reactome apoptosis (p<0.001; NES-1.7). In these patients, expression of 750 genes was up-regulated (FDR<0.05; FC >2); however, they did not form a specific pathway. The up-regulated genes were classified as so-called leukemia-associated antigens (LAAs) such as PRAME (adjusted p=6.9e-09; logFC=6.8), WT1AS (adjusted p=4.4e-07; logFC=5.7), BAALC (adjusted p=3.5e-06; logFC=2.1), WT1 (adjusted p=6.8e-07; logFC=3.2), FLT3 (adjusted p=0.004; logFC=1.3) and LEF1 (adjusted p=5.3e-08; logFC=-4.2). Conclusions To study the transcriptome of the hematopoietic stem cells of LR-MDS patients, we used gene expression profiling and identified biological processes in relation to mutations in RUNX1 gene that were detected in patients with disease progression. According to our results, we suppose that cells of LR-MDS patients with no mutations are maintained in senescent state or apoptosis in opposite to RUNX1 mutated cells. Finding out of dysregulated senescence was reinforced by other dysregulated pathways such as HDACs deacetylate histones, chromatin structural changes and senescence-associated secretory phenotype. About cellular senescence is known that may act as a strong tumor suppression mechanism that restrains proliferation of cells at risk for malignant transformation. We suppose that in precancerous cells of LR-MDS patients apoptosis or cellular senescence limits the replicative capacity of cells, thus preventing the proliferation. The disturbed state of cellular senescence in RUNX1 gene mutated hematopoietic stem cell can escape proliferation control and then can contribute to the disease progression in these patients. Supported by grants NV18-03-00227 and 00023736 from the Ministry of Health of the Czech Republic. Disclosures No relevant conflicts of interest to declare.


Author(s):  
Ruchi Kumari ◽  
Parmjit Jat

Cellular senescence is a stable cell cycle arrest that can be triggered in normal cells in response to various intrinsic and extrinsic stimuli, as well as developmental signals. Senescence is considered to be a highly dynamic, multi-step process, during which the properties of senescent cells continuously evolve and diversify in a context dependent manner. It is associated with multiple cellular and molecular changes and distinct phenotypic alterations, including a stable proliferation arrest unresponsive to mitogenic stimuli. Senescent cells remain viable, have alterations in metabolic activity and undergo dramatic changes in gene expression and develop a complex senescence-associated secretory phenotype. Cellular senescence can compromise tissue repair and regeneration, thereby contributing toward aging. Removal of senescent cells can attenuate age-related tissue dysfunction and extend health span. Senescence can also act as a potent anti-tumor mechanism, by preventing proliferation of potentially cancerous cells. It is a cellular program which acts as a double-edged sword, with both beneficial and detrimental effects on the health of the organism, and considered to be an example of evolutionary antagonistic pleiotropy. Activation of the p53/p21WAF1/CIP1 and p16INK4A/pRB tumor suppressor pathways play a central role in regulating senescence. Several other pathways have recently been implicated in mediating senescence and the senescent phenotype. Herein we review the molecular mechanisms that underlie cellular senescence and the senescence associated growth arrest with a particular focus on why cells stop dividing, the stability of the growth arrest, the hypersecretory phenotype and how the different pathways are all integrated.


2020 ◽  
Vol 2020 ◽  
pp. 1-28
Author(s):  
Provvidenza M. Abruzzo ◽  
Silvia Canaider ◽  
Valeria Pizzuti ◽  
Luca Pampanella ◽  
Raffaella Casadei ◽  
...  

Cellular senescence plays a very important role in organismal aging increasing with age and in age-related diseases (ARDs). This process involves physiological, structural, biochemical, and molecular changes of cells, leading to a characteristic trait referred to “senescence-associated secretory phenotype (SASP).” In particular, with aging, stem cells (SCs) in situ exhibit a diminished capacity of self-renewal and show a decline in their functionality. The identification of interventions able to prevent the accumulation of senescent SCs in the organism or to pretreat cultured multipotent mesenchymal stromal cells (MSCs) prior to employing them for cell therapy is a main purpose of medical research. Many approaches have been investigated and resulted effective to prevent or counteract SC senescence in humans, as well as other animal models. In this work, we have reviewed the chance of using a number of herb-derived products as novel tools in the treatment of cell senescence, highlighting the efficacy of these agents, often still far from being clearly understood.


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