Tao Bo, Shi Keqin
Department of Orthopaedics, Nanjing Medical University Affiliated Wuxi Second Hospital, Wuxi city in Jiangsu province, China.
Department of Orthopaedics, Nanjing Medical University Affiliated Wuxi Second Hospital, Wuxi city in Jiangsu province, China
Ann Clin Lab Sci. 2016 Winter;46(1):49-53.
Hypoxia-inducible factor 1-alpha (HIF-1α) protects hypoxic cells from apoptosis and necrosis under ischemic and anoxic conditions. miRNAs are important regulators in the genome. This study aims to explore whether miR-195 is involved in spinal cord injury through HIF-1α. A total of 40 male Sprague-Dawley (SD) rats were separated into four groups: Sham, Control, Ad-con, and Ad-miR-195. The behavior recovery was explored using the Basso, Beattie and Bresnahan (BBB) scoring system. Then, the rats were sacrificed, and the spinal cords were collected. The levels of the HIF-1α, Bcl-2, Bax and VEGF proteins were explored using western blotting. H&E and immunohistochemistry were applied to study the morphological changes. qPCR analysis revealed that miR-195 was significantly decreased after spinal cord injury (SCI). Meanwhile, the expression of Bcl-2, VEGF and HIF-1α was increased in animals after SCI. More importantly, administration with Ad-miR-195 significantly decreased the HIF-1α protein level, thereby reducing Bcl-2 and VEGF expression. In addition, Ad-miR-195 also obviously increased the number of apoptotic cells and decreased the neurological recovery in the animals injected with Ad-miR-195. In conclusion, reduced miR-195 expression partially protects rats from spinal cord injury, primarily by targeting HIF-1α.
缺氧诱导因子1α（HIF-1α）可在缺血缺氧条件下保护缺氧细胞免于凋亡和坏死。微小RNA（miRNA）是基因组中的重要调节因子。本研究旨在探讨miR-195是否通过HIF-1α参与脊髓损伤。将40只雄性Sprague-Dawley（SD）大鼠分为四组：假手术组、对照组、腺病毒对照（Ad-con）组和腺病毒miR-195（Ad-miR-195）组。使用Basso、Beattie和Bresnahan（BBB）评分系统评估行为恢复情况。然后，处死大鼠并收集脊髓。采用蛋白质印迹法检测HIF-1α、Bcl-2、Bax和血管内皮生长因子（VEGF）蛋白水平。应用苏木精-伊红（H&E）染色和免疫组织化学方法研究形态学变化。定量聚合酶链反应（qPCR）分析显示，脊髓损伤（SCI）后miR-195显著降低。同时，SCI后动物体内Bcl-2、VEGF和HIF-1α的表达增加。更重要的是，给予Ad-miR-195可显著降低HIF-1α蛋白水平，从而降低Bcl-2和VEGF的表达。此外，Ad-miR-195还明显增加了注射Ad-miR-195的动物体内的凋亡细胞数量，并降低了神经功能恢复。总之，miR-195表达降低可部分保护大鼠免受脊髓损伤，主要是通过靶向HIF-1α实现的。
