Effects of propranolol on femoral fracture healing in mice via miR-92a-3p
Objective To explore the effect of propranolol on femoral fracture healing in mice through regulation of microRNA-92a-3p(miR-92a-3p)and its mechanism.Methods C57BL/6J male mice were randomly divided into sham group(equal amount of 0.9%NaCl),model group(equal amount of 0.9%NaCl),experimental group(50 mg·kg-1 propranolol administration),inhibitor group(mice were injected with 100 mg·kg-1 miR-92a-3p inhibitor via tail vein on the basis of the experimental group).Femur was severed and molded in all mice except sham operation group.X-ray was used to observe bone healing.Quantitative real time polymerase chain reaction was used to detect the expression of miR-92a-3p in femur tissues.The expression level of bone formation and bone metabolism markers was detected by enzyme linked immunosorbent assay.Western blot was used to detect the expression of pathway-related proteins.Results The X-ray scores of femur in sham group,model group and experimental group were 11.20±2.60,4.70±1.50 and 9.60±2.40,respectively;the relative expression levels of miR-92a-3p in sham operation group,model group,experimental group and inhibitor group were 1.00±0.09,0.73±0.06,0.90±0.07 and 0.78±0.06;alkaline phosphatase levels were(35.21±2.63),(43.16±3.29),(67.58±5.37)and(49.62±4.05)U·L-1,respectively;crosslaps levels were(4.57±0.52),(8.41±0.91),(4.26±0.67)and(5.73±0.84)ng·mL-1,respectively;the relative expression levels of brain derived neurotrophic factor were 1.00±0.14,0.58±0.05,0.83±0.09 and 0.71±0.06,respectively;the relative expression levels of phospho-tyrosine kinase receptor B were 1.00±0.12,0.62±0.05,0.89±0.08 and 0.76±0.07,respectively;the relative expression levels of phospho-extracellular regulated protein kinases were 1.00±0.11,0.54±0.04,0.78±0.07 and 0.65±0.05,respectively.The above indexes in the model group were compared with those in the sham group,those in the experimental group were compared with those in the model group,and those in the inhibitor group were compared with those in the experimental group,and the differences were statistically significant(P<0.05,P<0.001).Conclusion Propranolol can promote femoral fracture healing in mice,which may be achieved by up-regulating miR-92a-3p activation of brain derived neurotrophic factor/tyrosine kinase receptor B/extracellular regulated protein kinases signaling pathway.
propranololbrain derived neurotrophic factorextracellular regulated protein kinasesfemoral fracturetyrosine kinase receptor B