bcl-XL抗视网膜光感受器细胞凋亡作用的实验研究

目的评价抗凋亡基因bcl-XL对视网膜光感受器细胞的抗凋亡作用.方法首先建立谷氨酸损伤的SD大鼠视网膜光感受器细胞凋亡模型.将体外培养的光感受器细胞分为A组(正常对照组)、B组(谷氨酸组)及C组(rAd-gfp-bcl-XL转染+谷氨酸组);其中C组在加入谷氨酸前48h用滴度为6.5×l012 pfu/mL的重组腺病毒rAd-gfp-bcl-XL转染光感受器细胞;荧光显微镜下观察光感受器细胞中的绿色荧光蛋白表达情况;用免疫组化法分析rAd-gfp-bcl-XL转染细胞和未转染细胞Bcl-XL蛋白水平;DNA琼脂糖凝胶电泳以评判3个组神经元凋亡发生与否及凋亡程度;采用Hoechst33258染色做正常核和凋亡核的形态学检测.结果免疫组化检测结果表明转染细胞与未转染细胞的Bcl-XL蛋白表达水平有差异,DNA电泳分析发现B组呈典型的DNA"梯度"条带,而A组和C组几乎无DNA"梯度"条带,核形态学检测结果亦证实转染组较未转染组的核有明显差异.结论重组腺病毒介导转染的bcl-XL对体外培养的视网膜光感受器细胞有抗凋亡作用,提高视网膜光感受器细胞bcl-XL的表达水平可能为视网膜变性疾病提供潜在有效的治疗方法.

Study of bcl-X(L) protection on retinal photoreceptors from apoptosis in vitro

OBJECTIVE: To assess the effect of bcl-X(L), an anti-apoptotic gene, on glutamate-induced apoptosis in cultured retinal photoreceptors. METHODS: Glutamate-induced apoptosis in cultured retinal photoreceptors was established. The experiment was divided into three groups: control, glutamate treatment and rAd-gfp-bcl-X(L) + glutamate transfection group, the protection of bcl-X(L) on retinal photoreceptors from apoptosis was evaluated. 6.5 x 10(12) pfu/L rAd-gfp-bcl-X(L) were transfected into retinal photoreceptors in the rAd-gfp-bcl-X(L) + glutamate group 48 h before Glutamate-induced apoptosis was established. The positive photoreceptors with green fluorescence were identified under fluorescence microscopy. The expression of Bcl-X(2) protein in rAd-gfp-bcl-X(L) transfected and non-transfected neurons were assessed by immunohistochemistry assay. DNA fragment was detected by agarose gel electrophoresis. Nuclei were revealed by hoechst33258 staining. RESULTS: rAd-mediated gene delivery can transfect retinal photoreceptors effectively. Increased expression of Bcl-X(L) protein was demonstrated in the rAd-transfecting neurons. Transfection of bcl-X(L) significantly decreased the number of apoptotic retinal photoreceptors in vitro. CONCLUSION: Transfection of bcl-X(L) protects cultured retinal photoreceptors from apoptosis induced by glutamate. Transfection the gene of bcl-X(L) may be a potential gene therapy for retinal degenerative diseases.