miR-155 inhibits chondrocyte pyroptosis in knee osteoarthritis by targeting SMAD2 and inhibiting the NLRP3/Caspase-1 pathway

Journal of Orthopaedic Surgery and Research

Lijun Xiu¹  Lisha Ma¹  Xiaoyun Li²  Gen Li³  Jihui Zhou⁴ 

[1] Department of Hand and Foot Surgery, Qingdao Eighth People’s Hospital;Department of Ophthalmology, Qingdao Eighth People’s Hospital;Department of Spine Surgery, QingDao HuangDao District Central Hospital;Department of Traumatic Orthopedics, Maoming People’s Hospital;

关键词: Knee osteoarthritis;    miR-155;    SMAD2;    Pyroptosis;    NLRP3;    Caspase-1;   

DOI  :  10.1186/s13018-021-02886-5

来源: DOAJ

【 摘 要 】

Abstract Objective Knee osteoarthritis (KOA) is based on degenerative pathological changes. miR-155 is involved in regulating KOA. This study estimated the mechanism of miR-155 in mouse KOA chondrocytes. Methods Mouse KOA chondrocyte model was established by lipopolysaccharide (LPS) induction and identified through Collagen II immunofluorescence staining and toluidine blue staining. LPS-induced KOA chondrocytes were transfected with miR-155 inhibitor or/and si-SMAD2, followed by the evaluation of miR-155 expression, pyroptosis, the SMAD2/NLRP3/Caspase-1 axis-related protein levels, IL-1β and 1L-18 levels, and cell viability by RT-qPCR, FAM-FLICA Caspase-1 Detection Kit, Western blot, ELISA, and MTT assays, respectively. The binding sites between miR-155 and SMAD2 were predicted online and the binding relationship was verified by dual-luciferase assay. Results miR-155 was highly-expressed in LPS-induced KOA chondrocytes. miR-155 knockdown increased cell viability and decreased pyroptotic chondrocytes, and Caspase-1, 1L-1β and 1L-18 levels. miR-155 targeted SMAD2. SMAD2 knockdown partially annulled the effects of miR-155 silencing on inhibiting KOA chondrocyte pyroptosis. NLRP3 pathway was activated in LPS-induced KOA chondrocytes, inhibited after miR-155 knockdown, and activated again after further SMAD2 knockdown. NLRP3 inhibition suppressed Caspase-1, IL-1β, and IL-18 levels and chondrocyte pyroptosis and increased cell viability. Conclusion miR-155 knockdown inhibited the NLRP3/Caspase-1 pathway by targeting SMAD2, thus inhibiting mouse KOA chondrocyte pyroptosis.

【 授权许可】

Unknown