Wang Xu, Tay Samuel Sam-Wah, Ng Yee-Kong
Department of Anatomy, Faculty of Medicine, National University of Singapore, MD10, 4 Medical Drive, 10 Kent Ridge Crescent, Singapore 117597.
Exp Brain Res. 2002 Jun;144(3):365-72. doi: 10.1007/s00221-002-1045-5. Epub 2002 Mar 19.
The present study was initiated to investigate the expressions of c-fos and c-jun in nitric oxide synthase immunoreactive neurons and their possible roles in the lateral geniculate nucleus (LGN) of glaucomatous rats. An experimental one-eye glaucoma model was created by cauterisation of the limbal-derived veins. Animals were killed by cardiac perfusion, and brains containing the LGN were removed and processed for c-fos, c-jun and neuronal nitric oxide synthase (nNOS) immunohistochemistry. No c-fos or c-jun immunoreactivity was observed in the LGN of control rats. In the glaucomatous rats, expression of c-fos and c-jun was induced bilaterally in the ventral LGN (vLGN) as early as 2 h postoperation. The number of c-fos-immunopositive cells increased at 1 and 2 days postoperation in both the lateral and medial subdivisions of the vLGN (vLGN-l and vLGN-m). Thereafter, the expression decreased and was totally absent at 1 and 2 weeks. No c-fos was induced in the dorsal LGN (dLGN). C-jun-immunopositive cells were mainly localised in the intergeniculate leaflet and vLGN. Few neurons were observed in the dLGN. The number of c-jun-immunopositive cells decreased at 1 and 2 weeks postoperation. Some of the c-fos- and c-jun-immunopositive cells were also nNOS immunopositive. The present results reveal that glaucoma activates the expressions of immediate early genes (IEGs) in some cells of the LGN. It is postulated that they may play important roles in the pathologic processes of glaucoma. The relationship between these IEGs and nitric oxide was also discussed.
本研究旨在探讨c-fos和c-jun在一氧化氮合酶免疫反应性神经元中的表达及其在青光眼大鼠外侧膝状体（LGN）中的可能作用。通过烧灼角膜缘静脉建立实验性单眼青光眼模型。动物经心脏灌注处死，取出含LGN的脑并进行c-fos、c-jun和神经元型一氧化氮合酶（nNOS）免疫组织化学处理。在对照大鼠的LGN中未观察到c-fos或c-jun免疫反应性。在青光眼大鼠中，早在术后2小时，双侧腹侧LGN（vLGN）就诱导了c-fos和c-jun的表达。术后1天和2天，vLGN的外侧和内侧亚区（vLGN-l和vLGN-m）中c-fos免疫阳性细胞数量增加。此后，表达下降，在1周和2周时完全消失。背侧LGN（dLGN）中未诱导出c-fos。c-jun免疫阳性细胞主要位于间膝叶和vLGN。在dLGN中观察到的神经元很少。术后1周和2周，c-jun免疫阳性细胞数量减少。一些c-fos和c-jun免疫阳性细胞也是nNOS免疫阳性。目前的结果表明，青光眼激活了LGN某些细胞中即刻早期基因（IEGs）的表达。据推测，它们可能在青光眼的病理过程中起重要作用。还讨论了这些IEGs与一氧化氮之间的关系。
