摘要
目的探讨高糖对体外培养的大鼠视网膜Muller细胞的活力和谷氨酸代谢功能有否改变及其可能机制。方法将体外培养的大鼠视网膜Muller细胞随机分为正常葡萄糖组（5mmol／L）和高糖组（25mmol／L），培养24h后MTT自动比色法测定两组细胞的活力，采用间接荧光免疫组化法和Western蛋白印迹法检测两组细胞胶质纤维酸性蛋白（GFAP）和磷酸化的信号转导及转录活化因子3（pSTAT3）的表达情况；采用间接荧光免疫组化法实时PCR检测两组细胞谷氨酰胺合成酶（GS）和c-Jun的蛋白和mRNA表达变化。结果MTT结果显示高糖状态下细胞活力提高，与对照组相比差异有统计学意义；与对照组相比，高糖组细胞GFAP、pSTAT3、c-Jun蛋白和mRNA的表达均升高，而GS蛋白和mRNA的表达降低。结论经高糖处理的Mailer细胞活力提高，其机制可能与GFAP和pSTAT3的表达升高有关；GS表达下降的可能机制为高糖激活了c-Jun基因。Mtiller细胞由于谷氨酸循环中的关键酶GS的表达减少而代谢谷氨酸的能力下降，这可能是糖尿病视网膜病变中导致神经节细胞死亡的机制之一。
Objective To investigate the viability of rat retinal Mailer cells and glutamate metabolism in these cells cultured in high glucose condition in vitro. Methods Cultured rat retinal Mailer cells were divided into control group （ 5 mmol/L glucose） or experimental group （25 mmol/L glucose）. After incubation for 24 h, the cell viability was detected by MTT colorimetry assay and expressions of glia fibrillary acidic protein （GFAP） and phosphorylated signal transducers and activators of transcription3 （pSTAT3） were evaluated by indirect inununofluorescence and western blot. The protein and mRNA expressions of glutamine synthetase （GS） and c-Jun were analyzed by indirect inununofluorescence or realtime PCR respectively. Results The viability of Mailer cells induced by high glucose was significantly increased as compared with control （ P 〈 0.05 ） and their expressions of GFAP, pSTAT3, c-Jun protein and mRNA were upregnlated, and expressions of GS protein and mRNA were downregnlated. Conclusion High glucose results in increased Muller cell viability, which may be related to the upregulation of GFAP and pSTAT3 expressions. Also high glucose decreases the expression of GS by activating c- Jun. GS is the key enzyme in glutamate cycle, and abnormal GS can result in decreased ability of metabolizing glutamate, which is one of the mechanisms of ganglion cell death in diabetic retinopathy.
出处
《中华内分泌代谢杂志》
CAS
CSCD
北大核心
2008年第1期74-77,共4页
Chinese Journal of Endocrinology and Metabolism
基金
上海市科委登山计划-基础研究（06jc14015）
