8.A.136.1.14
Thioredoxin-interacting protein (TXNIP), also known as thioredoxin-binding protein-2, is a member of the α-arrestin protein family and is regulated by several cellular stress factors. It is a 391 aa protein possibly with two TMSs, one near the N-terminus and one between residues 260 and 300. TXNIP overexpression coupled with thioredoxin inhibits its antioxidant functions, thereby increasing oxidative stress (Jiang et al. 2022). TXNIP is directly involved in inflammatory activation by interacting with Nod-like receptor protein 3 inflammasomes. Bone metabolic disorders are associated with aging, oxidative stress, and inflammation. They are characterized by an imbalance between bone formation involving osteoblasts and bone resorption by osteoclasts, and by chondrocyte destruction. The role of TXNIP in bone metabolic diseases has been extensively investigated. Jiang et al. 2022 discussed the roles of TXNIP in the regulatory mechanisms of transcription and protein levels and summarized its involvement in bone metabolic disorders such as osteoporosis, osteoarthritis, and rheumatoid arthritis. TXNIP is expressed in osteoblasts, osteoclasts, and chondrocytes, and it affects the differentiation and functioning of skeletal cells through both redox-dependent and redox-independent regulatory mechanisms (Jiang et al. 2022). It activates HSF1 (heat shock factor 1) in Brown adipose tissue (Waldhart et al. 2023).