摘要
目的研究大明胶囊(Daming capsule,DM)对链脲佐菌素(streptozocin,STZ)诱导的1型糖尿病大鼠胰腺microRNA(miRNA)表达谱的影响,预测miRNA的靶点并进行分析。方法将45只成年雄性Sprague-Dawley大鼠随机分为3组:空白组、模型组及DM组。DM组大鼠灌胃给予200 mg/(kg·d)的DM,空白组和模型组给予同等体积的生理盐水,每天2次。2周后,模型组及DM组腹腔注射STZ 65mg/kg建立1型糖尿病模型,注射STZ后DM组大鼠按上述剂量继续给予DM,空白组和模型组给予同等体积的生理盐水,每天2次。STZ注射后3天、7天检测大鼠空腹血糖,并于STZ注射后7天取大鼠胰腺组织。microRNA芯片技术检测各组大鼠胰腺组织miRNA表达,实时荧光定量PCR(real-time PCR,RT-PCR)验证miRNA芯片结果。Targetscan数据库预测miRNA靶点。结果大鼠腹腔注射STZ 3天和7天后,大鼠空腹血糖值由(6.1±0.6)上升至(21.9±3.1)和(24.6±2.4)mmol/L(P<0.01)。DM组大鼠的空腹血糖为(6.5±0.8)mmol/L,STZ后3天和7天的血糖分别为(14.1±5.1)和(12.4±4.8)mmol/L(P<0.01),明显低于同期模型组血糖水平(P<0.01)。在STZ大鼠胰腺,有47个miRNAs表达上调大于2倍,32个miRNAs表达下调大于2倍;DM大鼠胰腺组织,有35个miRNAs表达上调大于2倍,34个miRNAs表达下调大于2倍。其中在STZ大鼠胰腺组织表达上调的21个miRNAs及下调的8个miRNAs的表达被DM逆转;随机选择miR-200b、let-7b和miR-375进行RT-PCR验证的结果显示,这些miRNAs的表达与芯片结果一致;对DM纠正的miRNAs靶点分析发现这些靶点参与了胰腺β细胞胰岛素的生成、分泌和葡萄糖代谢及胰岛细胞凋亡。结论 DM降低了STZ诱导的1型糖尿病大鼠的空腹血糖,并改变了大鼠胰腺组织miRNA表达谱;miRNAs通过调节胰岛素生成、分泌、葡萄糖代谢和胰岛细胞的凋亡参与了DM的降血糖作用。
Objective To investigate the influence of Daming capsule（ DM） on microRNA（ miRNA） expression profile in type 1 diabetic rats induced by streptozocin（ STZ） and analyze function of targets of the changed miRNAs. Methods Forty-five male Sprague-Dawley ratswere randomly divided into three groups： control group（ Ctl）,diabetes group（ DI） and DM group. Rats in DM group were intragastrically administrated with DM 200 mg /（ kg·d）,twice a day,while rats in Ctl and DI groups were administrated with the same volume of physiological saline. Two weeks later,the rats in DI and DM groups were intraperitoneally injected with STZ65 mg / kg to establish a model of type 1 diabetes mellitus,and rats in DM group were continually administrated with DM and rats in Ctl and DI groups administrated with the same volume of physiological saline. Fasting blood glucose of rats was detected at days 3 and 7 after STZ injection and pancreas tissue was removed at day 7. The expression profile of miRNA was detected by miRNA microarray in pancreas tissue from the rats. Real-time PCR was employed to verify the data of miRNA microarray. The target proteins of miRNA were predicted by Targetscan database. Results Blood glucose of STZ-treated rats was markedly increased from（ 6. 1 ± 0. 6）to（ 21. 9 ± 3. 1） and（ 24. 6 ± 2. 4） mmol / L at days 3 and 7 after STZ injection,respectively（ P 0. 01）. Blood glucose level of DM was（ 6. 5 ± 0. 8） mmol/L before STZ and（ 14. 1 ±5. 1） and（ 12. 4 ± 4. 8） mmol / L at days 3 and 7 after STZ,which were significantly lower compared with DI group at the same time points. In STZ rats,47 miRNAs were up-regulated more than 2 folds,and 32 down-regulated more than 2 folds in pancreas tissue. In DM rats,35 miRNAs were found upregulated and 34 downregulated in pancreas tissue. Among the altered miRNAs,expressions of 21 up-regulated miRNAs and 8 down-regulated miRNAs were reversed in DM rats. RT-PCR results confirmed microarray data by measuring expressions of miR-200 b,let-7b and miR-375 that were randomly selected from the altered miRNAs. Targets of the reversed miRNAs were analysed and showed closely association with molecules or pathways that were involved in the production and secretion of insulin,and glucose metablism as well as apoptosis of pancreatic β cells. Conclusion DM lowers increased blood glucose and induces changes in the expression profile of miRNAs in pancreatic tissue of diabetic rats. miRNAs are potentially involved in the process of diabetes through regulating metabolism of insulin and glucose as well as apoptosis of pancreatic β cells.
出处
《哈尔滨医科大学学报》
CAS
2015年第1期1-7,共7页
Journal of Harbin Medical University
基金
国家重点基础研究发展计划(2012CB723505)
