miR-122/SIRT1 axis regulates chondrocyte extracellular matrix degradation in osteoarthritis.

BACKGROUND/AIMS: MicroRNAs (miRNAs) are involved in the pathogenesis of osteoarthritis (OA). The present study aimed to investigate the potential function of miR-122 in the development of OA and its potential molecular mechanisms. METHODS: The expression of miR-122, silent information regulator 1 (SIRT1), collagen II, aggrecan, matrix metalloproteinase (MMP) 13 (MMP13) and ADAMTS4 in OA cartilage was detected by RT-qPCR. Target gene prediction and screening, luciferase reporter assay were used to verify downstream target genes of miR-122. RESULTS: Compared with osteonecrosis, the expression of miR-122 was significantly increased in OA cartilage, while the expression of SIRT1 was significantly decreased. Overexpression of miR-122 increased the expression of extracellular matrix (ECM) catabolic factors, for example disintegrins, MMPs and metalloproteinases with platelet reaction protein motifs, and inhibited the expression of synthetic metabolic genes such as collagen II and aggregating proteoglycan. Inhibition of miR-122 expression had the opposite effect. Furthermore, SIRT1 was identified as a direct target of miR-122. SIRT1 was significantly inhibited by miR-122 overexpression. Knockdown of SIRT1 reversed the degradation of chondrocyte ECM by miR-122 inhibitors. CONCLUSION: The miR-122/SIRT1 axis can regulate the degradation of ECM in OA, thus providing new insights into the treatment of OA.

Treatment of the distal fracture in radioulna based on the volar wrist dual channel approach and postoperative X-ray diagnosis.

The fracture of the distal ulna and radius is a kind of fracture that results in high morbidity and occurrence rate and contributes to about one-sixth of the entire body's fracture. In this study, we implemented the improved palmar wrist surgery by a volar wrist dual channel approach. Between 2011 and 2014, we have treated 67 distal radius fracture patients. We divided them into two parts randomly, and treat them by the Carpometacarpal direct approach solution and dual wrist palmar surgical approach solution respectively. After the surgery, the differences in the incidence of median nerve irritation are significant (P < 0.01). With reference to the exposure time of fracture, the operation time and the pronator quadratus muscle repair rate, we find that the exposure time of fracture and the operation time in the dual wrist palmar surgical approach solution are much less than that as compared to the Carpometacarpal direct approach solution (P < 0.01). The improved dual wrist palmar surgical approach can lead to a successful treatment of the distal radius fractures volar distal radial ulnar by reducing the blind exposure problem. As such, the surgeon can complete treatment of fractures of the region under direct vision during operation. Furthermore, reducing the median nerve in the carpal tunnel and the structure of the stretch can decrease the incidence of postoperative complications. Postoperative X-ray diagnosis is then performed to examine the patients' recovery and assist in clinical follow-up. Our study proves that the volar wrist dual channel approach can be successfully achieved by a surface incision surgical implementation of the dual channel, and gives rise to a minimally invasive operation.