Objective To investigate the effect and mechanism of miR-4287, a chondrogenesis associated microRNA, regulated the expression of aggrecanase-1 (a disintegrin and metalloproteinase with thrombospondin motif 4, ADAMTS4) in human chondrocytes. Methods First, the voluntarily donated normal and osteoarthritic knee articular cartilages were used to detect the expressions of miR-4287 and ADAMTS4 mRNA by real-time fluorescence quantitative PCR. Then, chondrocytes were isolated from knee articular cartilages. The effect of IL-1β on the expression of miR-4287 and ADAMTS4 mRNA was validated by the first generation of osteoarthritic chondrocytes. To confirm the influence of IL-1β signal pathways on the expression of miR-4287 and ADAMTS4 mRNA, osteoarthritic chondrocytes were pretreated with MAPK signal pathway inhibitor SP600125, NF-κB pathway inhibitor SN50, and finally stimulated with IL-1β. Chondro cytes were transfected with miR-4287 mimics and mimics negative control, inhibitors and inhibitors negative control respectively to value the effect of miR-4287 on ADAMTS4 expression. Luciferase reporter assay was used to verify the direct interaction between miR-4287 and putative site in the 3-untranslated region (3’UTR) of ADAMTS4 mRNA. Results Compared with normal knee articular cartilages, the miR-4287 expression was markedly diminished and conversely ADAMTS4 mRNA expression was raised in osteoarthritis cartilages (P<0.05). Stimulation with IL-1β led to a reduction in miR-4287 expression and upregulation in ADAMTS4 mRNA expression, showing significant difference when compared with the untreated groups (P<0.05). Pretreatment with IL-1β signal pathway inhibitors induced miR-4287 expression and attenuated ADAMTS4 mRNA expression in human chondrocytes, which were significantly different from that of unstimulated cells (P<0.05). ADAMTS4 mRNA and protein were suppressed by transfection with miR-4287 mimics (P<0.05) and elevated by transfection with miR-4287 inhibitors (P<0.05). As luciferase reporter assay showed, overexpression miR-4287 failed to alter the luciferase activity of a reporter construct containing either wild or mutant 3’UTR of ADAMTS4 mRNA (P>0.05). Conclusion miR-4287, a chondrogenesis associated microRNA, may play an important role in cartilage degeneration. miRNA-4287 is able to regulate ADAMTS4 expression in human chondrocytes, but not by means of directly targeted the ADAMTS4 mRNA 3’UTR. The exact mechanisms need to be further addressed.
Objective To analyze the performance of epidemic prevention of Sichuan Province in the reconstruction stage after Wenchuan earthquake, so as to provide references for future epidemic prevention when such emergencies occur. Methods Data about the relief work were collected from the archives of Centers of Disease Control and Prevention in earthquake-stricken areas. And then the data were classified and analyzed. Results In the reconstruction stage, epidemic prevention followed principals of local-based, local-management, assistance-relied and joint -forces-pushed. The strategies included strengthening the capacity of CDCs through personnel training and improving abilities of hygiene service. Owing to these strategies, the epidemic prevention in Sichuan Province was conducted vigorously, orderly and effectively. Conclusion The epidemic prevention strategies in the reconstruction stage in Sichuan Province are accurate and effective, which could be recommended when such emergencies occur in future.