消朦灵对糖尿病大鼠视网膜TNF-α及JAK/STAT信号转导通路的调控作用

摘要

目的:探讨消朦灵片对肿瘤坏死因子α(TNF-α)和Janus激酶2/信号转导与转录激活子途径5(JAK2/STATS)信号通路的调控作用,及防治糖尿病视网膜病变的机理.方法:实验研究.选取50只SD雄性大鼠,随机抽取8只作为空白组.余42只以链脲佐菌素(STZ)腹腔注射诱导制作糖尿病大鼠模型;造模成功40只,随机分成模型组、低剂量组、中剂量组和高剂量组,每组10只.模型组不予处理,低剂量组、中剂量组和高剂量组分别给予消朦灵片0.1 g/100 g、0.2 g/100 g、0.3 g/100 g进行治疗.治疗4个月后观察各组大鼠体质量、血糖变化.通过光学显微镜及透射电子显微镜观察视网膜超微结构变化.采用Western Blot法检测TNF-α、JAK2/STAT5蛋白表达的变化.对相关数据行重复测量资料的方差分析及单因素方差分析.结果:空白组大鼠视网膜中TNF-α、JAK/STAT有少量表达,模型组表达较多,消朦灵低剂量、中剂量、高剂量组表达依次减少,其中高剂量组表达明显下降,差异有统计学意义(F=4.61、4.23、3.28,P＜0.05).生物光学显微镜下大鼠视网膜结构,空白组结构正常;模型组各层组织排列紊乱,视网膜水肿,毛细血管扩张明显,神经节细胞数量减少,细胞核固缩,内核层空泡变性;高剂量组视网膜各层排列欠规则,轻度水肿,神经节细胞及内核层数量减少.透射电镜下空白组大鼠视网膜结构正常;模型组外节膜盘中段断裂、溶解、溃变,线粒体嵴消失,排列不规则,视锥细胞形态不规则,核中染色质分布不均匀,毛细血管基底膜增厚,管腔狭窄;高剂量组视网膜外节膜盘间隙扩大,排列欠整齐,部分线粒体肿胀变形,视锥细胞核染色欠均匀,毛细血管基底膜厚度不均匀.结论:消朦灵对糖尿病大鼠视网膜中TNF-α、JAK/STAT信号通路有显著的调控作用,能有效防止糖尿病视网膜微血管病变,延缓糖尿病视网膜病变的进程.%Objective:To research the regulating effects of Xiaomengling on the tumor necrosis factor α (TNF-α),Janus kinase 2/signal transducer and activator of transcription 5 (JAK2/STAT5) signaling pathway,and to study its mechanism in preventing and curing diabetic retinal microangiopathy.Methods:This was an experimental research study.Fifty male SD rats were chosen and acclimated for 5 days.Eight rats were randomly chosen as the blank group;diabetic models were established in the other 42 rats with streptozotozin (STZ).Forty rats were modeled successfully and were divided randomly into 4 groups:10 rats were the model group and 30 rats were the treatment group.In the treatment group,10 rats were given a 0.1 g/100 g dose of Xiaomengling (low-dose group),10 were given a 0.2 g/100 g dose of Xiaomengling (medium-dose group),and 10 were given a 0.3 g/100 g dose of Xiaomengling (high-dose group).After 4 months of treatment,body mass and blood sugar change were observed,and changes in the retinal ultrastructure were observed under light microscopy and electron microscopy.The protein expression change in TNF-α,JAK2/STAT5 was observed by Western blot.Relevant data were analyzed with repeated measures analysis of variance.Results:TNF-α,JAK/STAT expression was visible in the retinas of the blank group.More expression was visible in the model group;expressions were reduced successively in the low-dose,medium-dose and high-dose groups.The comparison between groups was statistically significantly (F=4.61,4.23,3.28,P＜0.05).By observing retinal structures of rats under light microscopy,rats in the blank group had normal retinal structures.Rats in the model group had deranged distribution in each layer,obvious retinal edema and telangiectasia,decreased number of ganglion cells,karyopyknosis and inner nuclear layer vacuolar degeneration.Rats in the high-dose treatment group had default arrangements in each retinal layer,slight edema,a decreased number of ganglion cells and inner nuclear layers.Under retinal electron microscopy,rats in the blank group had normal retinal structures.The middle parts of the retinal rod outer segments of rats in the model group were ruptured,dissolved and degenerated.The mitochondrial cristae disappeared,and had no orderly pattern,their cones were irregular in shape,chromatin was distributed unevenly in the nucleus,the retinal capillary basement membrane was thickening and the channel was narrow.The spaces between the retinal rod outer segments in the high-dose treatment group were expanded and were not regular enough in alignment.Some of the mitochondria were swollen and deformed,the nuclear chromosomes in the cone cells had no orderly pattem,and the thickness of the retinal capillary basement membrane was uneven.Conclusions:Xiaomengling has significant regulating effects on the TNF-α and JAK2/STAT5 signal transduction pathway of diabetic rats,and can effectively slow or prevent diabetic retinal microangiopathy.