脑室周围白质软化新生鼠脑组织中Olig1基因动态表达与髓鞘修复关系研究

Olig1 gene expression in brain tissue of newborn rat of periventricular leukomalacia and the relation with remyelination

目的观察脑室周围白质软化（PVL）新生大鼠脑组织中Olig1转录因子动态变化，探讨其与髓鞘损伤、修复过程的关系。方法通过双侧颈总动脉结扎、8％低氧0．5h制备新生大鼠PVL动物模型；采用原位杂交方法检测实验组大鼠术后当天、7d、14d脑组织Olig1转录因子表达水平的动态变化；采用免疫组化法检测未成熟少突胶质细胞（OLPs）、成熟少突胶质细胞（OL）数量；采用荧光定量PCR检测髓鞘碱性蛋白（MBP）、蛋白脂蛋白（PLP）、髓鞘相关糖蛋白（MAG）的表达情况。结果术后当天Olig1阳性细胞数（72±20）／mm^2、术后7d[（75±12）／mm^2]均较对照组[（115±15）／mm^2]明显降低（JP均〈0．05），术后14d Olig1阳性细胞数[（146±11）／mm^2]较对照组明显增加（P〈0．05）。谷胱甘肽S-转移酶-∏（GST—∏）表达阳性的成熟OL细胞在术后当天及7d均较对照组减少（P均〉0．05），术后14dGST-∏1-I表达阳性的成熟OL细胞有所增加，但仍低于对照组（P〉0．05）。而术后当天及术后7dO4表达阳性的OLPs较对照组明显减少（P均〈0．05）。术后14dO4表达阳性的OLPs明显增加，但与对照组比较差异无显著性（P〉0．05）。髓鞘特异性蛋白MBP、PLP和MAG的mRNA水平在术后当天及7d均较对照组明显降低（P〈0．05），术后14d时以上蛋白的mRNA水平有所增加，但与对照组相比，差异无显著性（P〉0．05）。结论Olig1转录因子是PVL发生发展过程中再次髓鞘化和髓鞘修复过程中关键因素。

Objective To determine Oligl transcription factor expression in periventricular tissue of day 2 newborn rat of periventricular leukomalacia （PVL） and to explore the relation with remyelination. Methods PVL newborn rat model was successfully established through bilateral common carotid artery ligation,followed by 8% oxygen exposure for 30 min. On day 0 ,day 7 and day 14 after operation ,Olig1 expression was examined through in situ hybridization, oligodendrocyte precursor cells and oligodendrocytes were detected via immunohistochemistry method and mRNA levels of MBP, PLP, MAG in control and PVL group were examined with quantitative real-time PCR. Results Olig1 positive cells of control group were 115 ±15/mm^2. On day 0 and day 7 after operation, olig1 positive cells were 72 ± 20/mm^2 and 75 ± 12/mm^2, and there was significant difference as compared with control group （P both 〈 0. 05 ）, however the oligl positive cells on day 14 after operation（ 146 ± 11/mm^2 ） significantly increased with comparison to control group （P 〈 0. 05 ）. Compared to control group, GST-∏ positive oligodendrocytes and O4 positive oligodendroglial progenitor cells of PVL group were significantly decreased on day 0, day 7 after operation （P both 〈 0.05 ）, and these cells both increased on day 14 after operation ,however there was no difference as compared with control group （ P 〉 0. 05 ）. Compared to control group, mRNA levels of MBP, PLP, MAG all significantly decreased on day 0, day 7 after oPeration （ P all 〈 0. 05 ）, and these levels slightly increased on day 14 after oPeration （ P 〉 0.05 ）. Conclusion Olig1 transcription factor may be essential in the remyelination and repair of myelin in PVL.