MiRNA-125a-5p Agomir Protects Blood Spinal Cord Barrier Function And Promotes Motor Function Recovery In Rats With Spinal Cord Injury

ObjectiveA rat spinal cord injury model was established to simulate spinal cord injury.The effects of microRNA-125a-5p on blood-spinal cord barrier and motor function after spinal cord injury were detected by altering the content of microRNA-125a-5p after spinal cord injury.MethodsAdult female SD rats weighing 150-180 g were randomly divided into four groups.Sham group,SCI group,NC group and experimental group of intrathecal injection of microRNA-125a-5p agomir(MiRNA group).The content of microRNA-125a-5p in target spinal cord segments of each group was detected by RT-PCR.The expression of tight junction proteins(ZO-1,occludin,Claudin-5)was detected by Western blotting and immunofluorescence time.The function of blood-spinal cord barrier(BSCB)was evaluated by detecting the level of Evans blue exudation.Finally,Nissl staining and BBB score were used to determine the amount of motor neurons in the anterior horn of spinal cord and the recovery of motor function.ResultsThe content of miRNA-125a-5p after intrathecal introduction of miRNA-125a-5p agomir(1.37±0.04)was significantly higher than that in SCI group(P<0.05).The relative expression of tight junction proteins(ZO-1,occludin,Claudin-5)in MiRNA group was significantly higher than that in SCI group(1.16±0.10,2.18±0.11,2.32±0.05),the difference was statistically significant(P<0.05).The BSCB exudation rate in MiRNA group was significantly lower than that in SCI group(6.61±1.34)(P<0.05).The number of motor neurons in the anterior horn of spinal cord in MiRNA group(9.67±1.53)was higher than that in SCI group(P<0.05),and the BBB score showed that the motor function recovery in MiRNA group was significantly higher than that in SCI group(P<0.05).ConclusionsThe decrease of microRNA-125a-5p content in the injured center after spinal cord injury affects the function of BSCB,and indirectly leads to a serious decrease of hind limb motor function in rats.Introducing microRNA-125a-5p agomir can significantly reduce the degradation of tight junction protein in BSCB of rats after spinal cord injury,reduce the BSCB exudation rate,maintain the stability of the spinal cord environment and have great significance for the recovery of motor function.