RESUMO
AIM:To evaluate the effect of microRNA-155(miRNA-155) on the regulation of angiogenesis in diabetic rats with cerebral ischemic injury .METHODS: Adult male Sprague-Dawley rats were randomly divided into 5 groups:sham group, cerebral ischemia group , diabetic cerebral ischemia group , diabetic cerebral ischemia +miRNA-155 inhibitors group and diabetic cerebral ischemia +scramble group .Diabetes model was made by injection of streptozocin and permanent cerebral ischemic model was developed by suture-occluded method .The scores of neurological deficit and infarct volume were estimated at 24 h after cerebral ischemia .miRNA-155 level was detected by real-time polymerase chain reaction.The expression of platelet endothelial cell adhesion molecule-1 ( PECAM-1/CD31 ) and vascular endothelial growth factor ( VEGF) was detected by Western blotting .RESULTS:miRNA-155 inhibitor significantly reduced miRNA-155 levels in the ischemic cortex (P<0.05), improved the scores of neurological deficit , reduced infarction size and up-regulated the levels of CD31 and VEGF (P<0.05).CONCLUSION:miRNA-155 has a critical role in the regulation of angiogenesis in diabetic rats with cerebral ischemia .Down-regulation of miRNA-155 using miRNA-155 inhibitor attenuates brain infarct injury in diabetic rats .