ABSTRACT
MicroRNA (miR)-335-5P has the ability to regulate chondrogenic differentiation and promote chondrogenesis in mouse mesenchymal stem cells. It is also abnormally elevated in human osteoarthritic chondrocytes. However, the biological function of miR-335-5P in osteoarthritis (OA) is not well understood. The present study investigated the mechanism of miR-335-5P in the pathogenesis of OA. To investigate the effect of miR-335-5P on the pathogenesis of OA in vitro, a miR-335-5P mimic and inhibitor were transfected into chondrocytes. Cell Counting kit-8 assay and flow cytometry were used to observe the effects of miR-335-5P on chondrocyte apoptosis and the expression of cartilage-specific genes, such as aggrecan, collagen II, matrix metalloproteinase 13 and collagen X, were detected by reverse transcription-quantitative PCR and western blot analysis. Moreover, the current study assessed whether HMG-box transcription factor 1 (HBP1) is a novel target of miR-335-5P with dual luciferase reporter assays. Finally, a rescue experiment was used to prove the regulation between miR-335-5P and HBP1. The results revealed that HBP1 was a novel target of miR-335-5P, and that miR-335-5P mediated the apoptosis of chondrocytes and changes in cartilage-specific genes via targeting HBP1. Overall, the present study revealed that miR-335-5P mediated the development of OA by targeting the HBP1 gene and promoting chondrocyte apoptosis. These data suggested that miR-335-5P may be used to develop novel early-stage diagnostic and therapeutic strategies for OA.
ABSTRACT
BACKGROUND: This retrospective multicenter study investigated whether the presence of free fracture fragments is associated with the clinical outcome of adolescents with Delbet II femoral neck fracture (FNF). MATERIALS AND METHODS: The study population comprised 74 adolescents with Delbet II FNF, with an average age of 13.31 y (range, 10-17 y). There were 19 and 55 patients, respectively, with and without (control) free fracture fragments. The patients underwent open (n = 41) or closed (n = 33) fracture reduction and then cannulated screw internal fixation. Postoperative functional evaluation was performed using Ratliff's criteria, and complications such as femoral head necrosis, premature epiphyseal closure, and coxa vara were recorded. RESULTS: All patients achieved bony union during the mean follow-up period of 15.6 mo (range, 12-78 mo). By Ratliff's criteria, the clinical outcomes of the patients with free fracture fragment (three excellent, eight good, eight poor) were significantly worse compared with the control group (26 excellent, 20 good, and nine poor). The rate of complications (femoral head necrosis, premature epiphyseal closure, and coxa vara) of patients with free fracture fragments was significantly higher than that of the control patients. CONCLUSIONS: In adolescents with Delbet II FNF, the presence of free fracture fragments is associated with poorer clinical outcomes. Delbet II FNF in adolescents with free fracture fragment may be a special clinical entity with a poorer outcome.
