Rilong Jin1, Sanzhong Xu1, Xiangjin Lin1, Miaoda Shen2. 1. Department of Orthopedic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, China. 2. Department of Orthopedic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, China. Electronic address: mds@zju.edu.cn.
Abstract
BACKGROUND: Spinal cord ischemia is a serious injury that threatens human health and life. Furthermore, it was widely accepted that miR-136 was mediated in the spinal injury, while whether it regulated neurocytes apoptosis in I/R-induced spinal cord injury remains unclear. METHODS: Spinal cord ischemia injury (SCII) rats were induced by clamping the nontraumatic vascular clip on the abdominal aorta. Real-time PCR was conducted to determine the mRNA expression, and western blot was carried out to measure protein expression. TUNEL assay was used to measure cell apoptosis. RESULTS: MiR-136 was up-regulated, while Tissue Inhibitor of Metalloproteinases-3 (TIMP3) was down-regulated in both SCII rats and hypoxic neurocytes. MiR-136 overexpression protected neurocytes against injury that induced by hypoxia. TIMP3 was the target gene of miR-136. Hypoxia supplementation decreased the expression of miR-136, promoted TIMP3 expression, and urged cell apoptosis, cells transfected with miR-136 mimic reversed the effect that induced by hypoxia, while cells co-transfected with pcDNA-TIMP3 abolished the results that induced by overexpressed miR-136. CONCLUSION: MiR-136 regulated neurocytes apoptosis of SCII by mediating TIMP3.
BACKGROUND:Spinal cord ischemia is a serious injury that threatens human health and life. Furthermore, it was widely accepted that miR-136 was mediated in the spinal injury, while whether it regulated neurocytes apoptosis in I/R-induced spinal cord injury remains unclear. METHODS:Spinal cord ischemia injury (SCII) rats were induced by clamping the nontraumatic vascular clip on the abdominal aorta. Real-time PCR was conducted to determine the mRNA expression, and western blot was carried out to measure protein expression. TUNEL assay was used to measure cell apoptosis. RESULTS:MiR-136 was up-regulated, while Tissue Inhibitor of Metalloproteinases-3 (TIMP3) was down-regulated in both SCII rats and hypoxic neurocytes. MiR-136 overexpression protected neurocytes against injury that induced by hypoxia. TIMP3 was the target gene of miR-136. Hypoxia supplementation decreased the expression of miR-136, promoted TIMP3 expression, and urged cell apoptosis, cells transfected with miR-136 mimic reversed the effect that induced by hypoxia, while cells co-transfected with pcDNA-TIMP3 abolished the results that induced by overexpressed miR-136. CONCLUSION:MiR-136 regulated neurocytes apoptosis of SCII by mediating TIMP3.