γ-氨基丁酸受体基因转染对癫痫大鼠海马缝隙连接蛋白43表达的影响

Effects of GABA receptor gene transfection on expression of CX43 in hypothalamus of epileptic rats

目的:探讨下丘脑乳头体上核内转染γ-氨基丁酸(GABA)受体基因对海人藻酸(KA)致痫大鼠海马区缝隙连接蛋白43(CX43)表达的影响。方法:将24只Wistar雄性大鼠分为4组:正常对照组(n=2)、手术对照组(n=2)、KA对照组(n=10)及GABA受体基因转染组(n=10),正常对照组未经任何处置,手术对照组在右侧杏仁核注射生理盐水1μL,KA对照组在杏仁核注射KA 1μL(1μg),GABA受体基因转染组则在KA注射前48 h预先将GABA受体mRNA 400 nL(40 ng)注射到下丘脑的乳头体上核。采用原位杂交法观察4组大鼠各个时程(3 h、6 h、24 h、3 d、7 d)海马区形态及CX43阳性细胞数变化。结果:正常对照组和手术对照组大鼠海马神经元结构完整;KA对照组海马神经元肿胀变性,其程度随时间延长而加重;GABA受体基因转染组海马神经元变性坏死程度相对于KA对照组减轻。CX43表达阳性细胞数定量分析显示,正常及手术对照组CX43表达阳性细胞数较少,KA对照组随时间延长CX43阳性表达细胞数逐渐增多,GABA受体基因转染组大鼠CX43阳性表达细胞数在各个时程均比KA对照组减少。结论:下丘脑内转染GABA受体基因可以下调海马区CX43的表达。

Objective To investigate the expression of connexin CX43 using hybridization techniques after GABA restraining receptor gene was transferred into the supramammillary of hypothalamus in Kainic acid （KA） induced epileptic rats. Methods Twenty-four male Wistar rats were divided into four groups： control group （n = 2）, surgery group （n= 2）, KA group （n= 10） and GABA restraining receptor gene transferred group （GABA group） （n= 10）. No treatment was given to the control group. Physiological saline （1 μL） was injected into right amygdala of rat in surgery group. In KA group, KA （1μL, 1 μg） was injected into the amygdala of rat to build epileptic model. In GABA group, the GABA restraining receptor gene （400 nL, 40 ng） was transferred into the supramammillary of hypothalamus by HVJ-liposome 48 h before KA was injected into amygdala. The expressions of CX43 mRNA and morphological changes different time （3 h, 6 h, 24 h, 3d, 7d） were observed by in situ hybridization in each group. Results In control group and surgery group, the morphological manifestations were normal, and the hippocampus structures were complete. In KA group, swell and degenerative hippocampus neurons were showed and deteriorated with time. In GABA group, the degeneration and necroses of hippocampus neurons were relatively alleviated. The positive expression of CX43 mRNA was few in control group and surgery group. And in KA group it increased with time. In GABA group, the positive expression of CX43 mRNA was fewer than that of KA group at every period. Conclusion The expression of CX43 mRNA in hippocampus can be decreased by transferring GABA receptor gene into hypothalamus.