Cellular Senescence: Mechanisms, Morphology, and Mouse Models

2020 ◽  
Vol 57 (6) ◽  
pp. 747-757
Author(s):  
Jessica Beck ◽  
Izumi Horikawa ◽  
Curtis Harris
Keyword(s):  
Mouse Models ◽  
Cellular Senescence ◽  
Cardiac Fibrosis ◽  
Therapeutic Benefit ◽  
Associated Diseases ◽  
Cycle Arrest ◽  
A Cell ◽  
Secretory Phenotype ◽  
Global Population

Cellular senescence is a cell cycle arrest in damaged or aged cells. Although this represents a critical mechanism of tumor suppression, persistence of senescent cells during aging induces chronic inflammation and tissue dysfunction through the adoption of the senescence-associated secretory phenotype (SASP). This has been shown to promote the progression of age-associated diseases such as Alzheimer’s disease, pulmonary fibrosis, and atherosclerosis. As the global population ages, the role of cellular senescence in disease is becoming a more critical area of research. In this review, mechanisms, biomarkers, and pathology of cellular senescence and SASP are described with a brief discussion of literature supporting a role for cellular senescence in veterinary diseases. Cell culture and mouse models used in senescence studies are also reviewed including the senescence-accelerated mouse—prone (SAMP), senescence pathway knockout mice (p53, p21 [CDKN1A], and p16 [CDKN2A]), and the more recently developed senolysis mice, which allow for direct visualization and elimination (or lysis) of senescent cells in live mice (p16-3MR and INK-ATTAC). These and other mouse models have demonstrated the importance of cellular senescence in embryogenesis and wound healing but have also identified a therapeutic benefit for targeting persistent senescent cells in age-associated diseases including neurodegeneration, diabetes, and cardiac fibrosis.

scholarly journals Senescence and Cancer: Role of Nitric Oxide (NO) in SASP

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1145
Author(s):  
Nesrine Mabrouk ◽  
Silvia Ghione ◽  
Véronique Laurens ◽  
Stéphanie Plenchette ◽  
Ali Bettaieb ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cancer Treatment ◽  
Cellular Senescence ◽  
Negative Effects ◽  
No Donors ◽  
Cell State ◽  
Age Related ◽  
A Cell ◽  
Secretory Phenotype

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.

scholarly journals Nuclear pore density controls heterochromatin reorganization during senescence

2018 ◽  
Author(s):  
Charlene Boumendilrid ◽  
Priya Hari ◽  
Karl C. F. Olsen ◽  
Juan Carlos Acosta ◽  
Wendy A. Bickmore
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Tumour Progression ◽  
Nuclear Periphery ◽  
Nuclear Pore ◽  
Pore Density ◽  
Cycle Arrest ◽  
A Cell ◽  
Secretory Phenotype

AbstractOncogene induced senescence (OIS) is a cell cycle arrest program triggered by oncogenic signalling. An important characteristic of OIS is activation of the senescence associated secretory phenotype (SASP)1 which can reinforce cell cycle arrest, lead to paracrine senescence but also promote tumour progression2–4. Concomitant with cell cycle arrest and the SASP activation, OIS cells undergo a striking nuclear chromatin reorganization, with loss of heterochromatin from the nuclear periphery and the appearance of internal senescence-associated heterochromatin foci (SAHF)5. The mechanisms by which SAHF are formed, and their role in cell cycle arrest and expression of the SASP, remain poorly understood. Here we show that nuclear pore density increases during OIS and is responsible for SAHF formation. In particular, we show that the nucleoporin TPR is required for both SAHF formation and maintenance. The TPR-induced loss of SAHF does not affect cell cycle arrest but completely abrogates the SASP. Our results uncover a previously unknown role of nuclear pores in heterochromatin reorganization in mammalian nuclei and in senescence, which uncouples the cell cycle arrest from the SASP.

scholarly journals Cellular Senescence in Liver Disease and Regeneration

2021 ◽  
Author(s):  
Sofia Ferreira-Gonzalez ◽  
Daniel Rodrigo-Torres ◽  
Victoria L. Gadd ◽  
Stuart J. Forbes
Keyword(s):  
Cell Cycle ◽  
Liver Disease ◽  
Cell Cycle Arrest ◽  
Genomic Instability ◽  
Cellular Senescence ◽  
Cell Populations ◽  
Cycle Arrest ◽  
Relevant Role ◽  
Extent Of Damage

AbstractCellular senescence is an irreversible cell cycle arrest implemented by the cell as a result of stressful insults. Characterized by phenotypic alterations, including secretome changes and genomic instability, senescence is capable of exerting both detrimental and beneficial processes. Accumulating evidence has shown that cellular senescence plays a relevant role in the occurrence and development of liver disease, as a mechanism to contain damage and promote regeneration, but also characterizing the onset and correlating with the extent of damage. The evidence of senescent mechanisms acting on the cell populations of the liver will be described including the role of markers to detect cellular senescence. Overall, this review intends to summarize the role of senescence in liver homeostasis, injury, disease, and regeneration.

scholarly journals CRISPR enriches for cells with mutations in a p53-related interactome, and this can be inhibited

2021 ◽  
Author(s):  
Long Jiang ◽  
Katrine Ingelshed ◽  
Yunbing Shen ◽  
Sanjaykumar V. Boddul ◽  
Vaishnavi Srinivasan Iyer ◽  
...  
Keyword(s):  
Cellular Response ◽  
Human Cancer ◽  
Genetic Alterations ◽  
Dna Breaks ◽  
Data Set ◽  
Human Cancer Cell Lines ◽  
Cycle Arrest ◽  
Double Stranded Dna ◽  
A Cell

CRISPR/Cas9 can be used to inactivate or modify genes by inducing double-stranded DNA breaks1–3. As a protective cellular response, DNA breaks result in p53-mediated cell cycle arrest and activation of cell death programs4,5. Inactivating p53 mutations are the most commonly found genetic alterations in cancer, highlighting the important role of the gene6–8. Here, we show that cells deficient in p53, as well as in genes of a core CRISPR-p53 tumor suppressor interactome, are enriched in a cell population when CRISPR is applied. Such enrichment could pose a challenge for clinical CRISPR use. Importantly, we identify that transient p53 inhibition suppresses the enrichment of cells with these mutations. Furthermore, in a data set of >800 human cancer cell lines, we identify parameters influencing the enrichment of p53 mutated cells, including strong baseline CDKN1A expression as a predictor for an active CRISPR-p53 axis. Taken together, our data identify strategies enabling safe CRISPR use.

Extracellular vesicles, stem cells and the role of miRNAs in neurodegeneration

2021 ◽  
Vol 19 ◽  
Author(s):  
Ayaz M. Belkozhayev ◽  
Minnatallah Al-Yozbaki ◽  
Alex George ◽  
Raigul Ye Niyazova ◽  
Kamalidin O. Sharipov ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neurodegenerative Diseases ◽  
Extracellular Vesicles ◽  
Intercellular Communication ◽  
Direct Consequence ◽  
Therapeutic Benefit ◽  
The Body ◽  
A Cell ◽  
Crucial Information

There are different modalities of intercellular communication governed by cellular homeostasis. In this review, we will explore one of these forms of communication called extracellular vesicles (EVs). These vesicles are released by all cells in the body and are heterogeneous in nature. The primary function of EVs is to share information through their cargo consisting of proteins, lipids and nucleic acids (mRNA, miRNA, dsDNA etc.) with other cells, which have a direct consequence on their microenvironment. We will focus on the role of EVs of mesenchymal stem cells (MSCs) in the nervous system and how these participate in intercellular communication to maintain physiological function and provide neuroprotection. However, deregulation of this same communication system could play a role in several neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Amyotrophic lateral sclerosis, multiple sclerosis, prion disease and Huntington’s disease. The release of EVs from a cell provides crucial information to what is happening inside the cell and thus could be used in diagnostics and therapy. We will discuss and explore new avenues for the clinical applications of using engineered MSC-EVs and their potential therapeutic benefit in treating neurodegenerative diseases.

scholarly journals PDTM-09. Yap1 FUNCTION IN SEX-BIASED MEDULLOBLASTOMA FORMATION AND ANTI-TUMOR IMMUNITY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi188-vi188
Author(s):  
Nourhan Abdelfattah ◽  
Sivaraman Natarajan ◽  
Yaohui Chen ◽  
Kin-Hoe Chow ◽  
Shu-hsia Chen ◽  
...  
Keyword(s):  
Cytotoxic T Cells ◽  
Therapeutic Benefit ◽  
Tumor Formation ◽  
Normal Brain ◽  
A Cell ◽  
Developing Mouse Brain ◽  
Pediatric Brain ◽  
Normal Brain Development ◽  
Extended Survival

Abstract Immunotherapies offer remarkable potential to provide robust therapeutic benefit. Patients suffering from medulloblastoma (MB), the most frequent pediatric brain malignancy, can especially benefit from this approach, minimizing the devastating side effects of aggressive radiation and chemotherapies that disrupt normal brain development. However, regulators of the immune landscape remain poorly understood and no effective immunotherapies exist yet for MB. Here, we describe a sex-dependent Yap1 function in fSmoM2;GFAPcre SHH-MB (SG) mouse model. We show that Yap1 is both a cell-autonomous regulator of MB stem-cells and a non-cell-autonomous regulator of immune infiltrates in SHH-MB. Yap1 deletion in SG mice results in increased neuronal differentiation, significantly extended survival, and enhanced infiltration of peripheral blood immune cells (including cytotoxic T-cells, neutrophils, and macrophages). Additionally, this rescue phenotype is observed in a sex-biased manner: 65% of Yap1f/f;fSmoM2;GFAPcre males are rescued in contrast to 35% of females. These observations implicate Yap1 as a mediator of sex-biased brain-tumor formation, either through direct modulation of MB cells and/or through indirectly mediating the MB immune landscape. We are currently testing the role of sex-specific differences in the developing mouse brain to elucidate context-dependent function of Yap1 in MB genesis and maintenance.

Deciphering the mechanism for induction of senescence-associated secretory phenotype (SASP) and its role in ageing and cancer development

2019 ◽  
Vol 166 (4) ◽  
pp. 289-295 ◽  
Author(s):  
Naoko Ohtani
Keyword(s):  
Immune Responses ◽  
Cancer Progression ◽  
Cellular Senescence ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Cycle Arrest ◽  
Secreted Factors ◽  
Suppression Mechanism ◽  
Secretory Phenotype ◽  
Sting Pathway

Abstract Cellular senescence is an irreversible form of cell cycle arrest that can be induced by persistent DNA damage, and is well known to function as an important tumour suppression mechanism. Cellular senescence is detected in aged organisms; thus, it is also recognized as a hallmark of organismal ageing. Unlike apoptotic cells, senescent cells can survive for long periods of time. Recently, it has been shown that the late stage of senescent cells are capable of expressing a variety of secreted proteins such as cytokines, chemokines and proteases, and this condition is now known as senescence-associated secretory phenotype (SASP). These secreted factors are involved in myriad of physiological functions including tissue repair and clearance of damaged cells. Alternatively, these factors may promote detrimental effects, such as chronic inflammation or cancer progression, should the SASP persist. Recent scientific advances have indicated that innate immune responses, particularly involving the cGAS–STING pathway, trigger SASP induction. Therefore, developing a strategy to regulate SASP may provide scientific insights for the management of age-associated diseases and the implementation of healthy ageing in the future.

scholarly journals Cellular senescence contributes to radiation-induced hyposalivation by affecting the stem/progenitor cell niche

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Xiaohong Peng ◽  
Yi Wu ◽  
Uilke Brouwer ◽  
Thijmen van Vliet ◽  
Boshi Wang ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Cellular Senescence ◽  
Progenitor Cell ◽  
Tissue Degeneration ◽  
Cycle Arrest ◽  
Radiation Induced ◽  
Secretory Phenotype ◽  
Cell Niche ◽  
Gland Function ◽  
Formation Efficiency

Abstract Radiotherapy for head and neck cancer is associated with impairment of salivary gland function and consequent xerostomia, which has a devastating effect on the quality of life of the patients. The mechanism of radiation-induced salivary gland damage is not completely understood. Cellular senescence is a permanent state of cell cycle arrest accompanied by a secretory phenotype which contributes to inflammation and tissue deterioration. Genotoxic stresses, including radiation-induced DNA damage, are known to induce a senescence response. Here, we show that radiation induces cellular senescence preferentially in the salivary gland stem/progenitor cell niche of mouse models and patients. Similarly, salivary gland-derived organoids show increased expression of senescence markers and pro-inflammatory senescence-associated secretory phenotype (SASP) factors after radiation exposure. Clearance of senescent cells by selective removal of p16Ink4a-positive cells by the drug ganciclovir or the senolytic drug ABT263 lead to increased stem cell self-renewal capacity as measured by organoid formation efficiency. Additionally, pharmacological treatment with ABT263 in mice irradiated to the salivary glands mitigates tissue degeneration, thus preserving salivation. Our data suggest that senescence in the salivary gland stem/progenitor cell niche contributes to radiation-induced hyposalivation. Pharmacological targeting of senescent cells may represent a therapeutic strategy to prevent radiotherapy-induced xerostomia.

scholarly journals Hepatocellular Senescence: Immunosurveillance and Future Senescence-Induced Therapy in Hepatocellular Carcinoma

2020 ◽  
Vol 10 ◽  
Author(s):  
Peng Liu ◽  
Qinghe Tang ◽  
Miaomiao Chen ◽  
Wenjian Chen ◽  
Yanli Lu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cellular Senescence ◽  
Immune Surveillance ◽  
Targeted Drugs ◽  
New Strategy ◽  
Cell Induction ◽  
Tumorigenesis And Progression ◽  
Secretory Phenotype ◽  
Molecular Compounds

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. The lack of effective targeted drugs has become a challenge on treating HCC patients. Cellular senescence is closely linked to the occurrence, development, and therapy of tumor. Induction of cellular senescence and further activation of immune surveillance provides a new strategy to develop HCC targeted drugs, that is, senescence-induced therapy for HCC. Precancerous hepatocytes or HCC cells can be induced into senescent cells, subsequently producing senescence-associated secretory phenotype (SASP) factors. SASP factors recruit and activate various types of immune cells, including T cells, NK cells, macrophages, and their subtypes, which carry out the role of immune surveillance and elimination of senescent cells, ultimately preventing the occurrence of HCC or inhibiting the progression of HCC. Specific interventions in several checkpoints of senescence-mediated therapy will make positive contributions to suppress tumorigenesis and progression of HCC, for instance, by applying small molecular compounds to induce cellular senescence or selecting cytokines/chemokines to activate immunosurveillance, supplementing adoptive immunocytes to remove senescent cells, and screening chemical drugs to induce apoptosis of senescent cells or accelerate clearance of senescent cells. These interventional checkpoints become potential chemotherapeutic targets in senescence-induced therapy for HCC. In this review, we focus on the frontiers of senescence-induced therapy and discuss senescent characteristics of hepatocytes during hepatocarcinogenesis as well as the roles and mechanisms of senescent cell induction and clearance, and cellular senescence-related immunosurveillance during the formation and progression of HCC.

scholarly journals Insights from In Vivo Studies of Cellular Senescence

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 954
Author(s):  
Luis I. Prieto ◽  
Sara I. Graves ◽  
Darren J. Baker
Keyword(s):  
Cellular Senescence ◽  
Cell Biology ◽  
Senescent Cell ◽  
In Vivo Studies ◽  
Cycle Arrest ◽  
Mammalian Cell Lines ◽  
Age Related ◽  
Cell Accumulation ◽  
Secretory Phenotype

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.

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