{"title":"mTORC2 inhibition by JR-AB2-011 improves IL-1β-induced inflammation, catabolic response, and apoptosis in human chondrocytes through IκB-α/NF-κB p65.","authors":"Meryem Temiz-Resitoglu, Zainab Sabrie, Rukiye Nalan Tiftik, Taskın Kalkan, Ayca Aktas-Sukuroglu, Kafait U Malik, Seyhan Sahan-Firat","doi":"10.14715/cmb/2024.70.9.5","DOIUrl":null,"url":null,"abstract":"<p><p>Osteoarthritis (OA) is a very common chronic joint condition marked by inflammation and cartilage loss. mTOR is a well-known mediator of inflammation, cell survival, and aging; however, its role in OA has not been determined. To explore the role of mTORC2 in OA-and associated pathological changes, we examined the contribution of mTORC2-mediated Akt, rictor and IκB-α/NF-κB p65 pathway in interleukin (IL)-1β-treated human chondrocytes. We focused on the protein expression of proinflammatory cytokines and catabolic and apoptotic factors, including TNF-α, IL-6, iNOS, MMP13, Bax, and caspase3, which may occur through this signalling pathway in IL-1β-treated chondrocytes. Chondrocytes were cultured and treated with either 2 ng/mL IL‑1β alone or in combination with increasing concentrations of JR-AB2-011 (50, 100, or 250 µM), a selective mTORC2 inhibitor. The protein levels of phosphorylated (p)‑Akt, Akt, rictor, p-NF-κB p65, NF-κB p65, IκB-α, p-IκB-α, iNOS, MMP13, Bax, and caspase3 were evaluated by Western blotting. In IL-1β-stimulated chondrocytes, mTORC2 activity was increased with increased phosphorylation of Akt and expression of rictor. IL-1β increased the expression of p-IκBα, p-NF-κB p65, NF-κB p65, IL-6, TNF-α, iNOS, Bax, and caspase3 proteins and decreased the expression of IκB-α. All of these IL-1β-induced alterations were prevented by JR-AB2-011. The main novel finding in the present study is that selective mTORC2 inhibition by JR-AB2-011 prevents the inflammatory, catabolic, and apoptotic responses induced by IL-1β via modulation of IκB-α/NF-κB activity. Therefore, we demonstrated a previously unknown function of mTORC2 inhibition that seems to be a potential therapeutic target for OA.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4000,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Accounts of Chemical Research","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.14715/cmb/2024.70.9.5","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Osteoarthritis (OA) is a very common chronic joint condition marked by inflammation and cartilage loss. mTOR is a well-known mediator of inflammation, cell survival, and aging; however, its role in OA has not been determined. To explore the role of mTORC2 in OA-and associated pathological changes, we examined the contribution of mTORC2-mediated Akt, rictor and IκB-α/NF-κB p65 pathway in interleukin (IL)-1β-treated human chondrocytes. We focused on the protein expression of proinflammatory cytokines and catabolic and apoptotic factors, including TNF-α, IL-6, iNOS, MMP13, Bax, and caspase3, which may occur through this signalling pathway in IL-1β-treated chondrocytes. Chondrocytes were cultured and treated with either 2 ng/mL IL‑1β alone or in combination with increasing concentrations of JR-AB2-011 (50, 100, or 250 µM), a selective mTORC2 inhibitor. The protein levels of phosphorylated (p)‑Akt, Akt, rictor, p-NF-κB p65, NF-κB p65, IκB-α, p-IκB-α, iNOS, MMP13, Bax, and caspase3 were evaluated by Western blotting. In IL-1β-stimulated chondrocytes, mTORC2 activity was increased with increased phosphorylation of Akt and expression of rictor. IL-1β increased the expression of p-IκBα, p-NF-κB p65, NF-κB p65, IL-6, TNF-α, iNOS, Bax, and caspase3 proteins and decreased the expression of IκB-α. All of these IL-1β-induced alterations were prevented by JR-AB2-011. The main novel finding in the present study is that selective mTORC2 inhibition by JR-AB2-011 prevents the inflammatory, catabolic, and apoptotic responses induced by IL-1β via modulation of IκB-α/NF-κB activity. Therefore, we demonstrated a previously unknown function of mTORC2 inhibition that seems to be a potential therapeutic target for OA.
期刊介绍:
Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance.
Accounts of Chemical Research replaces the traditional article abstract with an article "Conspectus." These entries synopsize the research affording the reader a closer look at the content and significance of an article. Through this provision of a more detailed description of the article contents, the Conspectus enhances the article's discoverability by search engines and the exposure for the research.