Cytoplasmic innate immune sensing by the caspase-4 non-canonical inflammasome promotes cellular senescence

SummaryCytoplasmic recognition of microbially derived lipopolysaccharides (LPS) in human cells is elicited by the inflammatory cysteine aspartic proteases caspase-4 and caspase-5, which activate non-canonical inflammasomes inducing a form of inflammatory programmed cell death termed pyroptosis. Here we show that LPS mediated activation of the non-canonical inflammasome also induces cellular senescence and the activation of tumour suppressor stress responses in human diploid fibroblasts. Interestingly, this LPS-induced senescence is dependent on caspase-4, the pyroptotic effector protein gasdermin-D and the tumour suppressor protein p53. Also, experiments with a catalytically deficient mutant suggest that caspase-4 proteolytic activity is not necessary for its role in senescence. Furthermore, we found that the caspase-4 non-canonical inflammasome is induced and assembled during Ras-mediated oncogene-induced senescence (OIS). Moreover, targeting caspase-4 in OIS showed that the non-canonical inflammasome is critical for SASP activation and contributes to reinforcing the cell cycle arrest in OIS. Finally, we observed that caspase-4 induction occurs in vivo in models of tumour suppression and ageing. Altogether, we are unveiling that cellular senescence is induced by cytoplasmic microbial LPS recognition by the caspase-4 non-canonical inflammasome and that this pathway is conserved in the senescence program induced by oncogenic stress.

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Cytoplasmic innate immune sensing by the caspase-4 non-canonical inflammasome promotes cellular senescence

Cell Death and Differentiation ◽

10.1038/s41418-021-00917-6 ◽

2021 ◽

Author(s):

Irene Fernández-Duran ◽

Andrea Quintanilla ◽

Núria Tarrats ◽

Jodie Birch ◽

Priya Hari ◽

...

Keyword(s):

Cellular Senescence ◽

Cellular Response ◽

Critical Role ◽

Ras Signaling ◽

Tumor Suppressor P53 ◽

Oncogenic Ras ◽

Cycle Arrest ◽

Immune Sensing ◽

Innate Immune Sensing

AbstractCytoplasmic recognition of microbial lipopolysaccharides (LPS) in human cells is elicited by the caspase-4 and caspase-5 noncanonical inflammasomes, which induce a form of inflammatory cell death termed pyroptosis. Here we show that LPS-mediated activation of caspase-4 also induces a stress response promoting cellular senescence, which is dependent on the caspase-4 substrate gasdermin-D and the tumor suppressor p53. Furthermore, we found that the caspase-4 noncanonical inflammasome is induced and assembled in response to oncogenic RAS signaling during oncogene-induced senescence (OIS). Moreover, targeting caspase-4 expression in OIS showed its critical role in the senescence-associated secretory phenotype and the cell cycle arrest induced in cellular senescence. Finally, we observed that caspase-4 induction occurs in vivo in mouse models of tumor suppression and ageing. Altogether, we are showing that cellular senescence is induced by cytoplasmic LPS recognition by the noncanonical inflammasome and that this pathway is conserved in the cellular response to oncogenic stress.

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The innate immune sensor Toll-like receptor 2 controls the senescence-associated secretory phenotype

10.1101/466755 ◽

2018 ◽

Author(s):

Priya Hari ◽

Fraser R. Millar ◽

Nuria Tarrats ◽

Jodie Birch ◽

Curtis J. Rink ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Innate Immune ◽

Toll Like Receptor ◽

Cycle Arrest ◽

Secretory Phenotype ◽

Immune Sensing ◽

Molecular Patterns ◽

Innate Immune Sensing

ABSTRACTCellular senescence is a stress response program characterised by a robust cell cycle arrest and the induction of a pro-inflammatory senescence-associated secretory phenotype (SASP) that is triggered through an unknown mechanism. Here, we show that during oncogene-induced senescence (OIS), the Toll-like receptor TLR2 and its partner TLR10 are key mediators of senescence in vitro and in murine models. TLR2 promotes cell cycle arrest by regulating the tumour suppressors p53-p21CIP1, p16INK4a and p15INK4b, and regulates the SASP through the induction of the acute-phase serum amyloids A1 and A2 (A-SAA) that, in turn, function as the damage associated molecular patterns (DAMPs) signalling through TLR2 in OIS. Finally, we found evidence that the cGAS-STING cytosolic DNA sensing pathway primes TLR2 and A-SAA expression in OIS. In summary, we report that innate immune sensing of senescence-associated DAMPs by TLR2 controls the SASP and reinforces the cell cycle arrest program in OIS.

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Mammalian-unique eIF4E2 maintains GSK3β proline kinase activity to resist senescence against hypoxia

10.1101/2020.10.20.346569 ◽

2020 ◽

Author(s):

Min zhang ◽

Lei Sun ◽

Dong He ◽

Jian Chen ◽

Zhiqiang Dong ◽

...

Keyword(s):

Cell Cycle ◽

Cellular Senescence ◽

Kinase Activity ◽

Tumor Regression ◽

Stable State ◽

Conserved Motif ◽

Accelerate Senescence ◽

Cycle Arrest ◽

Living Organisms

AbstractCellular senescence is a stable state of cell cycle arrest elicited by various stresses. Hypoxia modulates senescence, but its consequences and implications in living organisms remains unknown. Here we identified the eIF4E2-GSK3β pathway regulated by hypoxia to maintain p53 proline-directed phosphorylation (S/T-P) to prevent senescence. We previously knew that GSK3β activates p53 translation through phosphorylation of RBM38 Ser195 (-Pro196). Unexpectedly, eIF4E2 directly binds to GSK3β via a conserved motif, mediating Ser195 phosphorylation. Phosphoproteomics revealed that eIF4E2-GSK3β specifically regulates proline-directed phosphorylation. Peptide e2-I or G3-I that disrupts this pathway dephosphorylates p53 at multiple S/T-P, which accelerate senescence by transcriptional suppressing TOPBP1 and TRX1. Consistently, peptides induce liver senescence that is rescued by TOPBP1 expression, and mediate senescence-dependent tumor regression. Furthermore, hypoxia inhibits eIF4E2-GSK3β. Inspiringly, eIF4E2-GSK3β is unique to mammals, which maintains mice viability and prevents liver senescence against physiological hypoxia. Interestingly, this mammalian eIF4E2 protects heart of zebrafish against hypoxia. Together, we identified a mammalian -unique eIF4E2-GSK3β pathway preventing senescence and guarding against hypoxia in vivo.

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Insights from In Vivo Studies of Cellular Senescence

Cells ◽

10.3390/cells9040954 ◽

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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Senescent Colon and Breast Cancer Cells Induced by Doxorubicin Exhibit Enhanced Sensitivity to Curcumin, Caffeine, and Thymoquinone

Integrative Cancer Therapies ◽

10.1177/1534735419901160 ◽

2020 ◽

Vol 19 ◽

pp. 153473541990116 ◽

Cited By ~ 3

Author(s):

Ali H. El-Far ◽

Noureldien H. E. Darwish ◽

Shaker A. Mousa

Keyword(s):

Breast Cancer ◽

Cell Cycle ◽

Cell Cycle Arrest ◽

Cancer Cells ◽

Cellular Senescence ◽

Annexin V ◽

Mcf7 Cells ◽

Enhanced Sensitivity ◽

Cycle Arrest

Cellular senescence is a process of physiological growth arrest that can be induced by intrinsic or extrinsic stress signals. Some cancer therapies are associated with senescence of cancer cells with a typical cell cycle arrest. Doxorubicin (Dox) induces senescence by a p53-dependent pathway and telomere dysfunction of numerous cancers. However, cellular senescence induces suppression in proliferation activity, and these cells will remain metabolically active and play an important role in tumor relapse and development of drug resistance. In the current study, we investigated the apoptotic effect of curcumin (Cur), caffeine (Caff), and thymoquinone (TQ) on senescent colon cancer HCT116 and breast cancer MCF7 cell lines treated with Dox. Results showed typical senescence markers including decreased bromodeoxyuridine incorporation, increased accumulation of senescence-associated β-galactosidase (SA-β-gal), cell cycle arrest, and upregulation of p53, P-p53, and p21 proteins. Annexin-V analysis by flow cytometry revealed 2- to 6-fold increases in annexin-V–positive cells in Dox-treated MCF7 and HCT116 cells by Cur (15 µM), Caff (10 mM), and TQ (50 µM; P < .001). In comparison between proliferative and senescent of either HCT116 or MCF7 cells, Caff at 15 mM and TQ at 25 µM induced significant increases in apoptosis of Dox-treated cells compared with proliferative cells ( P < .001). Data revealed that Cur, Caff, and TQ potentially induced apoptosis of both proliferative and senescent HCT116 and MCF7 cells. In vivo and clinical trials are of great importance to validate this result.

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Transcriptome signature of cellular senescence

Nucleic Acids Research ◽

10.1093/nar/gkz555 ◽

2019 ◽

Vol 47 (14) ◽

pp. 7294-7305 ◽

Cited By ~ 16

Author(s):

Gabriel Casella ◽

Rachel Munk ◽

Kyoung Mi Kim ◽

Yulan Piao ◽

Supriyo De ◽

...

Keyword(s):

Cellular Senescence ◽

Sequencing Analysis ◽

Multiple Traits ◽

Protein Coding ◽

Telomere Attrition ◽

Human Diploid Fibroblasts ◽

Non Coding Rnas ◽

Macromolecular Damage ◽

Transcriptome Signature

Abstract Cellular senescence, an integral component of aging and cancer, arises in response to diverse triggers, including telomere attrition, macromolecular damage and signaling from activated oncogenes. At present, senescent cells are identified by the combined presence of multiple traits, such as senescence-associated protein expression and secretion, DNA damage and β-galactosidase activity; unfortunately, these traits are neither exclusively nor universally present in senescent cells. To identify robust shared markers of senescence, we have performed RNA-sequencing analysis across eight diverse models of senescence triggered in human diploid fibroblasts (WI-38, IMR-90) and endothelial cells (HUVEC, HAEC) by replicative exhaustion, exposure to ionizing radiation or doxorubicin, and expression of the oncogene HRASG12V. The intersection of the altered transcriptomes revealed 50 RNAs consistently elevated and 18 RNAs consistently reduced across all senescence models, including many protein-coding mRNAs and some non-coding RNAs. We propose that these shared transcriptome profiles will enable the identification of senescent cells in vivo, the investigation of their roles in aging and malignancy and the development of strategies to target senescent cells therapeutically.

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The Preconditioning of Berberine Suppresses Hydrogen Peroxide-Induced Premature Senescence via Regulation of Sirtuin 1

Oxidative Medicine and Cellular Longevity ◽

10.1155/2017/2391820 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 8

Author(s):

Xiaofei Zhu ◽

Haodi Yue ◽

Xiaofang Guo ◽

Jingyi Yang ◽

Jingshuo Liu ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Cellular Senescence ◽

Sirtuin 1 ◽

Premature Senescence ◽

Low Concentration ◽

Human Diploid Fibroblasts ◽

Cycle Arrest ◽

Age Related ◽

History Of

With a long history of application in Chinese traditional medicine, berberine (BBR) was reported to exhibit healthspan-extending properties in some age-related diseases, such as type 2 diabetes and atherosclerosis. However, the antiaging mechanism of BBR is not completely clear. By means of hydrogen peroxide- (H2O2-) induced premature cellular senescence model, we found that a low-concentration preconditioning of BBR could resist premature senescence in human diploid fibroblasts (HDFs) measured by senescence-associated β-galactosidase (SA-β-gal), accompanied by a decrease in loss of mitochondrial membrane potential and production of intracellular reactive oxygen species (ROS). Moreover, the low-concentration preconditioning of BBR could make cells less susceptible to subsequent H2O2-induced cell cycle arrest and growth inhibition. Experimental results further showed that the low concentration of BBR could induce a slight increase of ROS and upregulate the expression level of sirtuin 1 (SIRT1), an important longevity regulator. H2O2-induced activation of checkpoint kinase 2 (Chk2) was significantly attenuated after the preconditioning of BBR. The present findings implied that the low-concentration preconditioning of BBR could have a mitohormetic effect against cellular senescence triggered by oxidative stress in some age-related diseases through the regulation of SIRT1.

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Tumour suppressor p53 down-regulates the expression of the human hepatocyte nuclear factor 4α (HNF4α) gene

Biochemical Journal ◽

10.1042/bj20060614 ◽

2006 ◽

Vol 400 (2) ◽

pp. 303-313 ◽

Cited By ~ 34

Author(s):

Yutaka Maeda ◽

Wendy W. Hwang-Verslues ◽

Gang Wei ◽

Takuya Fukazawa ◽

Mary L. Durbin ◽

...

Keyword(s):

P53 Protein ◽

Tumour Suppressor ◽

Nuclear Factor ◽

Hepatocyte Nuclear Factor ◽

Protein Levels ◽

Tumour Suppressor Protein ◽

Toxic Agents ◽

Hepatocyte Nuclear Factor 4Α

The liver is exposed to a wide variety of toxic agents, many of which damage DNA and result in increased levels of the tumour suppressor protein p53. We have previously shown that p53 inhibits the transactivation function of HNF (hepatocyte nuclear factor) 4α1, a nuclear receptor known to be critical for early development and liver differentiation. In the present study we demonstrate that p53 also down-regulates expression of the human HNF4α gene via the proximal P1 promoter. Overexpression of wild-type p53 down-regulated endogenous levels of both HNF4α protein and mRNA in Hep3B cells. This decrease was also observed when HepG2 cells were exposed to UV irradiation or doxorubicin, both of which increased endogenous p53 protein levels. Ectopically expressed p53, but not a mutant p53 defective in DNA binding (R249S), down-regulated HNF4α P1 promoter activity. Chromatin immunoprecipitation also showed that endogenous p53 bound the HNF4α P1 promoter in vivo after doxorubicin treatment. The mechanism by which p53 down-regulates the P1 promoter appears to be multifaceted. The down-regulation was partially recovered by inhibition of HDAC activity and appears to involve the positive regulator HNF6α. p53 bound HNF6α in vivo and in vitro and prevented HNF6α from binding DNA in vitro. p53 also repressed stimulation of the P1 promoter by HNF6α in vivo. However, since the R249S p53 mutant also bound HNF6α, binding HNF6α is apparently not sufficient for the repression. Implications of the p53-mediated repression of HNF4α expression in response to cellular stress are discussed.

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