新生大鼠脑白质损伤时GRP78和caspase-12基因表达变化研究

Expression of GRP78 and caspase-12 in neonatal rats with experimental hypoxic-ischemic white matter damage

摘要:

目的：GRP78被认为是内质网应激的一个敏感标志，caspase-12是内质网应激诱导调亡的关键分子。该研究探讨新生大鼠脑白质损伤时GRP78 mRNA和caspase-12 mRNA表达的变化及caspase-12介导的内质网应激在脑白质损伤中的作用。方法：进入实验的大鼠共96只，实验组和对照组各49只，实验组制备脑白质损伤动物模型，分别于缺氧缺血后0，2，4，6，12，24 h及72 h处死，苏木精-伊红染色观察脑组织病理学变化，实时PCR技术检测GRP78 mRNA及caspase-12 mRNA表达变化。结果：与对照组相比，实验组GRP78 mRNA在缺氧缺血后2 h表达开始上升，6 h达峰值，缺氧缺血后2，4，6，12，24，72 h表达均增加（P<0.05）。实验组caspase-12 mRNA在缺氧缺血后6 h开始表达上调，缺氧缺血后6，12，24 h均增加（P<0.05）。结论：新生大鼠脑白质损伤时，实验组GRP78 mRNA及caspase-12 mRNA表达较对照组显著升高，且表达升高有时序性。表明缺氧缺血导致内质网应激反应被激活，内质网应激可能是新生大鼠脑白质损伤的发病机制之一。［中国当代儿科杂志，2009，11（8）：691-694］

Abstract:

OBJECTIVE: GRP78 is a sensitive marker of endoplasmic reticulum stress. Caspase-12 is involved in apoptosis induced by endoplasmic reticulum stress. This study was designed to explore the changes of GRP78 and caspase-12 mRNA in neonatal rats with experimental hypoxic-ischemic white matter damage (WMD) and investigate the roles of endoplasmic reticulum stress in the WMD. METHODS: Two-day-old rats were randomized to WMD and control groups (n=49 each). The pups were sacrificed at 0, 2, 4, 6, 12, 24 and 72 hrs after hypoxia-ischemia (HI). The light microscope was used to observe the brain pathological changes. Real time PCR was used to detect the expression of GRP78 mRNA and caspase-12 mRNA in the white matter tissue. RESULTS: The expression of GRP78 mRNA began increasing 2 hrs after HI and peaked at 6 hrs in the WMD group, demonstrating significant differences at 2, 4, 6, 12, 24 and 72 hrs compared with the control group (P<0.05). The caspase-12 mRNA expression in the WMD group began increasing 6 hrs after HI and demonstrated significantly increased levels 6, 12 and 24 hrs after HI compared with those in the control group (P<0.05). CONCLUSIONS: GRP78 and caspase-12 mRNA expression increased significantly in neonatal rats with WMD. This suggests that endoplasmic reticulum stress may be induced following HI. Endoplasmic reticulum stress seems to be involved in the apoptosis of oligodendrocytes induced by HI in neonatal rats with WMD.［Chin J Contemp Pediatr, 2009, 11 (8):691-694］