MicroRNA-142 protects MC3T3-E1 cells against high glucose-induced apoptosis by targeting β-catenin.

Osteoporosis, characterized by decreased mineral density and bone mass, is triggered by various detrimental factors and often causes further complications, including fractures. Aberrant expression of microRNAs (miRs) has been associated with the pathogenesis of osteoporosis. Recently, miR-142 was reported to be downregulated in osteoblasts; however, the underlying mechanism of miR-142 in mediating the development of osteoporosis remains unclear. In the present study, high glucose induced the downregulation of miR-142 mRNA expression and promoted the apoptosis of MC3T3-E1 cells. miR-142-mimics significantly protected against high glucose-induced apoptosis, upregulated the expression levels of B-cell lymphoma 2 (Bcl-2) and downregulated the protein expression levels of β-catenin, Bcl-2 associated X (Bax) and caspase-3. Furthermore, β-catenin was identified as a direct target of miR-142 using luciferase reporter assays. Similar to the effects of miR-142 inhibitors, overexpression of β-catenin aggravated the apoptosis of MC3T3-E1 cells, as demonstrated by the upregulation of Bax and caspase-3, and the downregulation of Bcl-2 expression levels. In conclusion, miR-142 protects MC3T3-E1 cells against high glucose-induced apoptosis by targeting β-catenin.