MiR-92a inhibits fibroblast-like synoviocyte proliferation and migration in rheumatoid arthritis by targeting AKT2.

Growing data have indicated that the miR-17-92 cluster is implicated in inflammatory response and rheumatoid arthritis (RA). This study was aimed to investigate the effects of miR-92a on the proliferation and migration of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs). Our results showed that miR-92a was significantly down-regulated in RA synovial tissue and RA-FLSs, whereas the protein level of AKT2 is increased. Restoration of miR-92a suppressed the proliferation and migration of RA-FLSs. Down-regulation of miR-92a promotes proliferation and migration of normal human FLSs. Dual luciferase reporter gene assay showed that miR-92a could specifically bind with the 30UTR of AKT2 and significantly repressed the luciferase activity. Down-regulation or up-regulation of miR-92a significantly increased or decreased the protein and phosphorylation levels of AKT2. siRNA-mediated down-regulation of AKT2 significantly prevented cell proliferation and migration of RA-FLSs, which were similar to the effects induced by overexpression of miR-92a. Moreover, AKT2 overexpression rescued miR-92a-mediated suppressive effect on proliferation and migration of RA-FLS. Thus, miR-92a could inhibit the proliferation and migration of RA-FLSs through regulation of AKT2 expression.

[Case-control studies on double bundle posterior cruciate ligament reconstruction with remnant fiber preservation].

OBJECTIVE: To study the clinical efficacy of double bundle posterior cruciate ligament (PCL) reconstruction with remnant preservation. METHODS: From January 2007 to November 2011, 50 patients with PCL rupture met the inclusion criteria were divided into two groups: remnant preservation group (RP group) and remnant resection group (RR group). There were 19 males and 7 females in the RP group, ranging in age from 18 to 55 years, with a mean of (32.250 +/- 11.085) years old. The duration from injury to operation ranged from 2 to 66 months, with an average of (17.481 +/- 3.568) months. Among the RR group, 17 patients were male and 7 patients were female, ranging in age from 20 to 54 years old, with an average of (31.458 +/- 9.569) years. The duration from injury to operation ranged from 3 to 72 months, with a mean of (19.354 +/- 3.950) months. The patients in both groups suffered from instability of knee joint, got a positive result of posterior drawer test. In the RP group, the intercondylar notch remnant fiber, scar tissue and synovial were preserved in operation, only the free ligament in the intercondylar notch was resected. In the RR group, the remnant fiber, scar tissue and synovial tissue of adhesive parts were resected. In both groups, autologous semitendinosus and gracilis tendon double-bundle PCL reconstruction were carried out, the tibia was fixed with an absorbable interference screw with post-tie fixation, and the femur side was compositely fixed with absorbable interference screws and suspending fixation. Each patient received both subjective assessment (IKDC subjective evaluation, Lysholm scoring and Cincinnati rating) and objective clinical assessment (IKDC objective evaluation and Kneelax 3 tibia backward measurement) before operation and two years after operation. RESULTS: IKDC subjective evaluation: 92.167 +/- 4.177 in the RP group,which was higher than 87.542 +/- 5.687 in the RR group (P = 0.010). Lysholm scores: 90.917 +/- 4.413 in the RP group, which was higher than 87.083 +/- 5.149 in the RR group (P = 0.027). Cincinnati knee scores: 92.125 +/- 4.003 in the RP group, which was higher than 87.791 +/- 6.665 in the RR group (P = 0.027). IKDC objective evaluation:no significant statistical differences between RP group and RR group. Kneelax 3 assessment : tibia backward test with Kneelax 3 under 132 N showed no significant statistical difference between RP group and RR group, which were (3.958 +/- 0.693) mm and (4.029 +/- 0.846) mm respectively (P = 0.795). CONCLUSION: The study shows a significant advantage of remnant fiber preservation than remnant fiber resection in double-bundle PCL construction in terms of subjective knee function recovery after operation. There is no significant difference in postoperative knee stability.