RESUMO
BACKGROUND: The present study aimed to determine the role and mechanism of miR-23 with respect to regulating the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). MATERIALS: The expression of miR-23 and MEF2C was measured in osteoporosis (OP) patients and healthy controls by a quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The correlation between miR-23 and MEF2C was determined by the Pearson correlation coefficient. Moreover, bioinformatic analysis was performed using public databases. Target gene function and potential pathways were further examined. Then, we used a miR-23 mimic or inhibitor to further explore the potential mechanism of miR-23. RESULTS: miR-23 is found to be up-regulated and MEF2C is down-regulated in OP patients compared to healthy controls. miR-23 had a negative correlation with MEF2C (r = -0.937, p = 0.001). Bioinformatic analysis revealed that a total of 664 overlapping target genes were found in the TargetScan (http://www.targetscan.org), miRDB (http://mirdb.org) and miRanda (http://www.microrna.org/microrna/home.do) databases. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that miR-23 may regulate the mitogan-activated protein kinase (MAPK) signaling pathway. miR-23 is down-regulated and MEF2C is significantly up-regulated in the osteogenic differentiation of hBMSCs. MEF2C was significantly up-regulated in the osteogenic differentiation of hBMSCs. Overexpression of miR-23 significantly down-regulated alkaline phosphatase (ALP) activity and calcium deposition, whereas the miR-23 inhibitor had the opposite effects. Moreover, overexpression of miR-23 significantly decreased osteoblast-related markers (Runx2, Osx, ALP and OCN). Further experiments confirmed that MEF2C is a direct target of miR-23. Moreover, the miR-23 mimic enhanced the expression of p-p38 but had no effect on p-JNK. CONCLUSIONS: miR-23 decreases the osteogenic differentiation of hBMSCs through the MEF2C/MAPK signaling pathway.
Assuntos
Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , Osteogênese/genética , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Diferenciação Celular/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Sistema de Sinalização das MAP Quinases/genética , Fatores de Transcrição MEF2/genética , Células-Tronco Mesenquimais/patologia , Osteoblastos/metabolismo , Osteoblastos/patologiaRESUMO
OBJECTIVE: To study the reconstruction of partial defects at the end of the thumbs and other fingers with microsurgical free toe flaps. METHODS: 21 partial defects (19 cases) at the end of thumbs and other fingers were reconstructed with microsurgical free toe flaps taking from the corresponding toe part. RESULTS: All the free flaps survived. The patients were followed up for 3 - 6 months. The aesthetic and functional results were both satisfactory. The two-point-discrimination distance was 4 - 6 mm. CONCLUSIONS: The microsurgical free toe flaps have good therapeutic effect for the reconstruction of partial defects at the end of the fingers.