Chrysin ameliorates synovitis and fibrosis of osteoarthritic fibroblast-like synoviocytes in rats through PERK/TXNIP/NLRP3 signaling

Liang Ding; Taiyang Liao; Nan Yang; Yibao Wei; Runlin Xing; Peng Wu; Xiaochen Li; Jun Mao; Peimin Wang

doi:10.3389/fphar.2023.1170243

Chrysin ameliorates synovitis and fibrosis of osteoarthritic fibroblast-like synoviocytes in rats through PERK/TXNIP/NLRP3 signaling

Front Pharmacol. 2023 Mar 20:14:1170243. doi: 10.3389/fphar.2023.1170243. eCollection 2023.

Authors

Liang Ding^{1

2}, Taiyang Liao^{1

2

3}, Nan Yang^{1

2

3}, Yibao Wei^{1

2

3}, Runlin Xing^{1

2}, Peng Wu^{1

2}, Xiaochen Li^{1

2}, Jun Mao^{1

2}, Peimin Wang^{1

2}

Affiliations

¹ Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Liaoning, China.
² Jiangsu Province Hospital of Chinese Medicine, Nanjing, Jiangsu, China.
³ Key Laboratory for Metabolic Diseases in Chinese Medicine, First College of Clinical Medicine, Nanjing University of Chinese Medicine, Nanjing, China.

Abstract

Objective: Synovitis and fibrosis are common pathological features of knee osteoarthritis (KOA). The interaction of synovitis and fibrosis can promote KOA progression. Chrysin (CHR), a natural flavonoid, may treat inflammation and prevent fibrosis. However, the effect and mechanism of CHR in KOA synovitis and fibrosis remains unclear. Methods: The KOA model was established in male SD rats by anterior cruciate ligament transection (ACLT), and histological analysis was used to evaluate synovitis and fibrosis. IL-6, IL-1β and TNF-α mRNA expression in synovial tissue was measured by qRT‒PCR. Immunohistochemistry (IHC) was performed to detect GRP78, ATF-6 and TXNIP expression in vivo. Synovial fibroblasts (SFs) were treated with TGF-β1 to stimulate the inflammatory response and fibrosis. CCK-8 assays were used to detect the viability of CHR-treated SFs. The IL-1β level was detected by immunofluorescence analysis. Coimmunoprecipitation (Co-IP) and double immunofluorescence colocalization were used to detect the physiological interaction between TXNIP and NLRP3. The expression of fibrosis-related mediators and PERK/TXNIP/NLRP3 signaling molecules was detected by western blotting and qRT-PCR. Results: Four weeks after CHR treatment, pathological sections and associated scores showed that CHR improved synovitis and fibrosis in the ACLT model. In vitro, CHR attenuated the TGF-β1-induced inflammatory response and fibrosis in SFs. Moreover, CHR suppressed the expression of synovial fibrosis markers and PERK/TXNIP/NLRP3 signaling molecules in the synovial tissue of rats with ACLT and cultured SFs. More importantly, we found that CHR inhibited TXNIP-NLRP3 interactions in TGF-β-induced SFs. Conclusion: Our findings indicate that CHR can ameliorate synovitis and fibrosis in KOA. The underlying mechanism may be related to the PERK/TXNIP/NLRP3 signaling pathway.

Keywords: PERK/TXNIP/NLRP3; chrysin; fibrosis; knee osteoarthritis; synovial fibroblasts; synovitis.

Grants and funding

The current work was supported by the Development of Science and Technology Plan Projects of Chinese Medicine in Jiangsu Province (No. MS2021016), the National Natural Science Foundation of China (No. 82074460, 82274545), the Peak Academic Talent Project of Jiangsu Province Hospital of Chinese Medicine (No. y2021rc02, y2021rc20), the Jiangsu Provincial Medical Key Discipline (Laboratory) Cultivation Unit (js2252) and the Excellent Young Doctor Program of Jiangsu Hospital of Chinese Medicine (No. 2023QB0122). The authors would like to thank the Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, for their help.