Differential miRNAomics of the synovial membrane in knee osteoarthritis induced by bilateral anterior cruciate ligament transection in rats.

The differential microRNA (miRNA) omics of the synovial membrane were investigated using a rat model of knee osteoarthritis (KOA) induced by bilateral anterior cruciate ligament transection, which produced pathological biomarkers in KOA. Sprague‑Dawley rats were randomly divided into two groups; Sham‑operated and KOA‑operated group. The KOA rats were subjected to bilateral anterior cruciate ligament transection. After 6 weeks, total RNA was extracted from the knee joint synovial membrane of the rats and a microRNA (miR) microarray was performed to identify differentially expressed miRs. Subsequently, the obtained differentially expressed miRs were validated by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis. A total of 24 miRs were identified with alterations ≥1.5‑fold in the synovial membrane in the KOA‑operated group compared with the sham‑operated group, of which 4 miRs (miR‑532‑5p, ‑200b‑5p, ‑377‑3p and ‑759‑5p) were decreased and 20 miRs (miR‑382‑3p, ‑223‑3p, ‑100‑5p, ‑30d‑5p, ‑183‑5p, ‑130, ‑92b‑3p, ‑125b‑3p, ‑151‑3p, ‑155‑3p, 27a‑3p, ‑146b‑3p, ‑885‑5p, ‑352, ‑184, ‑345‑5p, ‑30a‑5p and ‑9a‑5p) were increased. Subsequently, RT‑qPCR was used to validate the expressions of miR‑223, ‑100, ‑345, ‑130, ‑382, ‑377, ‑352, ‑200b, ‑9a and ‑183, which were upregulated by a fold change of ≥1.5 in synovial membranes of KOA rats compared with shams. Furthermore, in vitro miR‑223 mimic could suppress the luciferase activity of NACHT, LRR and PYD domains‑containing protein 3 (NLRP3) 3' untranslated region by detecting of dual luciferase reporter vector. Additionally, the expression of NLRP3, interleukin (IL)‑1β and IL‑18 significantly increased in the synovial membrane of KOA rats. A total of 24 different miRs were determined by comparing the miRNAomics in the synovial membrane of the KOA model rats. Furthermore, the miR‑233‑regulated NLRP3 inflammasome was implicated in synovial membrane injury, which may be an important mechanism of KOA pathogenesis.