Thioredoxin-Interacting Protein’s Role in NLRP3 Activation and Osteoarthritis Pathogenesis by Pyroptosis Pathway: In Vivo Study

Abstract

Thioredoxin-interacting protein (TXNIP) has been involved in oxidative stress and activation of the NOD-like receptor protein-3 (NLRP3) inflammasome, directly linking it to the pyroptosis pathway. Furthermore, pyroptosis may contribute to the inflammatory process in osteoarthritis (OA). The purpose of this study was to investigate the role of TXNIP in activating the NLRP3 inflammasome through the pyroptosis pathway in an OA rat model. Destabilization of the medial meniscus (DMM) was induced in the OA model with intra-articular injections of adeno-associated virus (AAV) overexpressing (OE) or knocking down (KD) TXNIP. A total of 48 healthy rats were randomly divided into six groups (N = 8 each). During the experiment, the rats’ weights, mechanical pain thresholds, and thermal pain thresholds were measured weekly. Morphology staining, micro-CT, 3D imaging, and immunofluorescence (IF) staining were used to measure the expression level of TXNIP, and ELISA techniques were employed. OE-TXNIP-AAV in DMM rats aggravated cartilage destruction and subchondral bone loss, whereas KD-TXNIP slowed the progression of OA. The histological results showed that DMM modeling and OE-TXNIP-AAV intra-articular injection caused joint structure destruction, decreased anabolic protein expression, and increased catabolic protein expression and pyroptosis markers. Conversely, KD-TXNIP-AAV slowed joint degeneration. OE-TXNIP-AVV worsened OA by accelerating joint degeneration and damage, while KD-TXNIP-AAV treatment had a protective effect.