{"title":"Sustained activation of NF-κB through constitutively active IKKβ leads to senescence bypass in murine dermal fibroblasts.","authors":"Masayuki Harada, Kanae Su-Harada, Takeshi Kimura, Koh Ono, Noboru Ashida","doi":"10.1080/15384101.2024.2325802","DOIUrl":null,"url":null,"abstract":"<p><p>Although the transcription factor nuclear factor κB (NF-κB) plays a central role in the regulation of senescence-associated secretory phenotype (SASP) acquisition, our understanding of the involvement of NF-κB in the induction of cellular senescence is limited. Here, we show that activation of the canonical NF-κB pathway suppresses senescence in murine dermal fibroblasts. IκB kinase β (IKKβ)-depleted dermal fibroblasts showed ineffective NF-κB activation and underwent senescence more rapidly than control cells when cultured under 20% oxygen conditions, as indicated by senescence-associated β-galactosidase (SA-β-gal) staining and <i>p16<sup>INK4a</sup></i> mRNA levels. Conversely, the expression of <u>c</u>onstitutively <u>a</u>ctive IKKβ (IKKβ-CA) was sufficient to drive senescence bypass. Notably, the expression of a degradation-resistant form of inhibitor of κB (IκB), which inhibits NF-κB nuclear translocation, abolished senescence bypass, suggesting that the inhibitory effect of IKKβ-CA on senescence is largely mediated by NF-κB. We also found that IKKβ-CA expression suppressed the derepression of <i>INK4/Arf</i> genes and counteracted the senescence-associated loss of <i>Ezh2</i>, a catalytic subunit of the Polycomb repressive complex 2 (PRC2). Moreover, pharmacological inhibition of Ezh2 abolished IKKβ-CA-induced senescence bypass. We propose that NF-κB plays a suppressive role in the induction of stress-induced senescence through sustaining <i>Ezh2</i> expression.</p>","PeriodicalId":9686,"journal":{"name":"Cell Cycle","volume":null,"pages":null},"PeriodicalIF":3.4000,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11057680/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cell Cycle","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1080/15384101.2024.2325802","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/3/10 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Although the transcription factor nuclear factor κB (NF-κB) plays a central role in the regulation of senescence-associated secretory phenotype (SASP) acquisition, our understanding of the involvement of NF-κB in the induction of cellular senescence is limited. Here, we show that activation of the canonical NF-κB pathway suppresses senescence in murine dermal fibroblasts. IκB kinase β (IKKβ)-depleted dermal fibroblasts showed ineffective NF-κB activation and underwent senescence more rapidly than control cells when cultured under 20% oxygen conditions, as indicated by senescence-associated β-galactosidase (SA-β-gal) staining and p16INK4a mRNA levels. Conversely, the expression of constitutively active IKKβ (IKKβ-CA) was sufficient to drive senescence bypass. Notably, the expression of a degradation-resistant form of inhibitor of κB (IκB), which inhibits NF-κB nuclear translocation, abolished senescence bypass, suggesting that the inhibitory effect of IKKβ-CA on senescence is largely mediated by NF-κB. We also found that IKKβ-CA expression suppressed the derepression of INK4/Arf genes and counteracted the senescence-associated loss of Ezh2, a catalytic subunit of the Polycomb repressive complex 2 (PRC2). Moreover, pharmacological inhibition of Ezh2 abolished IKKβ-CA-induced senescence bypass. We propose that NF-κB plays a suppressive role in the induction of stress-induced senescence through sustaining Ezh2 expression.
期刊介绍:
Cell Cycle is a bi-weekly peer-reviewed journal of high priority research from all areas of cell biology. Cell Cycle covers all topics from yeast to man, from DNA to function, from development to aging, from stem cells to cell senescence, from metabolism to cell death, from cancer to neurobiology, from molecular biology to therapeutics. Our goal is fast publication of outstanding research.