The role of lncRNA TSIX in osteoarthritis pathogenesis: mechanistic insights and clinical biomarker potential.

Background: This study seeks to elucidate the expressions of lncRNA TSIX in Osteoarthritis (OA) and to explore its mechanisms in regulating OA progression.

Methods: RT-qPCR was employed to analyze the expression of TSIX in OA patients classified by Kellgren-Lawrence (K-L) grades. Receiver operator characteristic (ROC) was conducted to evaluate the diagnostic value of TSIX. Correlation between TSIX levels and clinical scores such as Lysholm and visual analogue scale (VAS) score was evaluated using Pearson method. IL-1β-induced SW1353 cells served as an in vitro model. The cell function were assessed by flow cytometry and cell counting kit-8 (CCK-8) assay. The relationship between TSIX and miR-320a was verified by luciferase reporting system, while bioinformatics approaches were utilized to predict the downstream target genes of miR-320a.

Results: The findings revealed that TSIX level in OA patients was elevated compared to that of the control group, with a notable progressive increase in TSIX expression correlated with higher K-L grades. In OA patients, the Lysholm score showed a negative correlation with TSIX expression, while the VAS score displayed a positive correlation with TSIX levels. Cell studies demonstrated that inhibition of TSIX enhanced cell viability and mitigated IL-1β-induced apoptosis by targeting miR-320a, in addition to promoting Aggrecan and Collagen II secretion. Luciferase reporter assay further validated the targeting interaction among TSIX, miR-320a, and PTEN.

Conclusions: This study demonstrated an increased expression of TSIX in OA patients. It suggests that TSIX may play a role in chondrocyte dysfunction during OA by modulating the miR-320a/PTEN axis.