內源性白血病抑制因子在脑室周围白质软化新生大鼠脑组织中的表达

Expression of endogenous leukemia inhibitory factor in neonatal rats with periventricular leukomalacia

摘要:

目的 探讨脑室周围白质软化（periventricular leukomalacia, PVL） 新生大鼠脑组织内源性白血病抑制因子（leukemia inhibitory factor, LIF）的表达变化。方法 采用左侧颈总动脉结扎并低氧（6% O₂ 4 h）处理建立 3 日龄 Wistar 大鼠缺氧缺血（HI）PVL 模型。HI 后 1 d、3 d、7 d、14 d 和 28 d 处死动物, 应用 Real-Time PCR 方法和 Western blot 方法分别检测脑组织 LIF mRNA 和蛋白的表达变化；应用免疫荧光双标染色方法检测 LIF 和胶质纤维酸性蛋白（glial fibrillary acidic protein, GFAP）的共表达情况。结果 HI 后 1、3、7 d PVL 组脑组织 LIF 蛋白表达量均高于对照组（均 P<0.01）；PVL 组脑组织 LIF 蛋白表达量于 HI 后 3 d 达到高峰，明显高于同组其他时间点（P<0.01），随后降低。LIF mRNA 的变化趋势与 LIF 蛋白一致。免疫荧光双标染色结果显示LIF 与 GFAP 存在共表达。结论 PVL 新生大鼠脑组织中星形胶质细胞 LIF mRNA 与蛋白的表达均呈先升高后降低的趋势；LIF 可能参与了 PVL 病变的修复过程。

Abstract:

Objective To study the changes of endogenous leukemia inhibitory factor（LIF) in neonatal rats with periventricular leukomalacia（PVL). Methods A PVL model of 3-day-old Wistar rats was prepared by left carotid artery ligation followed by 6% oxygen for 4 hours. The rats were sacrificed at 1, 3, 7, 14 and 28 days of hypoxia ischemia（HI), and the brain tissues were sampled. Real-Time PCR and Western blot methods were applied to analyze the expression of LIF mRNA and protein. Double staining immunofluorescence was used to detect the co-expression of LIF and GFAP. Results At 1, 3 and 7 days of HI, LIF protein level in the PVL group was higher than in the control group（P<0.01). In the PVL group, the LIF protein level on the third day after HI reached a peak and was higher than the other time points（P<0.01). The change of LIF mRNA expression showed the same tendency with LIF protein. The double staining immunofluorescence showed a co-expression of LIF and GFAP. Conclusion LIF mRNA and LIF protein expression in astrocytes show a trend of initial increase followed by steady decline in neonatal rats with PVL, suggesting that endogenous LIF may participate in the repair of PVL.