维生素D对大鼠脑外伤海马组织自噬及细胞凋亡的影响

摘要

Objective To explore the effect of vitamin D hormone(VDH)on autophagy and apoptosis in hippocampus of rats with traumatic brain injury(TBI). Methods A total of 45 male Sprague-Dawley rats were divided into control group(n=15),model group(n=15)and VDH group(n=15).The TBI model was established in the model group and VDH group.VDH group was injected with VDH 1 μg/kg 30 minutes,24 hours and 48 hours after modeling,respectively.The expression of microtubule as-sociated protein 1 light chain 3(LC3)and p62 was detected with Western blotting,and the number of apoptotic cells were detected with TUNEL three days after modeling.All groups were tested with Morris water maze on the fifth,sixth and seventh days. Results The number of TUNEL positive cells in hippocampus was more in the model group than in the control group (P<0.05),and was lower in VDH group than in the model group(P<0.05),as well as the expression of LC3II/LC3I and p62(P<0.05).The escape latency was longer in the model group than in the control group(P<0.05),and was shorter in VDH group than in the model group (P<0.05). There was no significant difference in the swimming velocity on the fifth,sixth,and seventh days among three groups(F=0.530,P>0.05). Conclusion VDH has potential neuroprotective effects on TBI,which might be associated with its anti-apoptosis effect on the expression of LC3 and p62 proteins in hippocampus after TBI.%目的 探讨低浓度维生素D3(VDH)对脑外伤大鼠海马组织内自噬和凋亡的影响.方法45只雄性Sprague-Dawley大鼠分为对照组(n=15)、模型组(n=15)和VDH组(n=15).后两组制作脑外伤模型,VDH组于造模后30 min、24 h、48 h腹腔注射VDH 1 μg/kg.3 d后,Western blotting检测海马组织微管相关蛋白轻链3(LC3)和p62的表达,TUNEL检测凋亡细胞数.三组均于造模后第5、6、7天进行Mor-ris水迷宫测试,记录逃避潜伏期及游泳速度.结果 模型组TUNEL阳性细胞数多于对照组(P<0.05),VDH组TUNEL阳性细胞数少于模型组(P<0.05).模型组LC3Ⅱ/LC3Ⅰ和p62表达均明显高于对照组(P<0.01),VDH组明显低于模型组(P<0.01).模型组逃避潜伏期明显长于对照组(P<0.01),VDH组逃避潜伏期短于模型组(P<0.05).三组大鼠第5、6、7天的平均游泳速度无显著性差异(F=0.530,P>0.05).结论 VDH对脑外伤大鼠有神经保护作用,可能与脑外伤后影响海马组织LC3、p62蛋白的表达,发挥抗凋亡作用有关.