Jin-tang-ning(JTN), a Chinese patent medicine, mainly comprised of Bombyx mori L., has been proved to show α-glucosidase inhibitory efficacy and clinically effective for the treatment of type 2 diabetes(T2 DM). Recen...Jin-tang-ning(JTN), a Chinese patent medicine, mainly comprised of Bombyx mori L., has been proved to show α-glucosidase inhibitory efficacy and clinically effective for the treatment of type 2 diabetes(T2 DM). Recently, we have reported that JTN could ameliorate postprandial hyperglycemia and improved β cell function in monosodium glutamate(MSG)-induced obese mice,suggesting that JTN might play a potential role in preventing the conversion of impaired glucose tolerance(IGT) to T2 DM. In this study, we evaluated the effect of JTN on the progression of T2 DM in the pre-diabetic KKAy mice. During the 10 weeks of treatment,blood biochemical analysis and oral glucose tolerance tests were performed to evaluate glucose and lipid profiles. The β cell function was quantified using hyperglycemic clamp at the end of the study. JTN-treated groups exhibited slowly raised fasting and postprandial blood glucose levels, and also ameliorated lipid profile. JTN improved glucose intolerance after 8 weeks of treatment. Meanwhile, JTN restored glucose-stimulated first-phase of insulin secretion and induced higher maximum insulin levels in the hyperglycemic clamp.Thus, to investigate the underlying mechanisms of JTN in protecting β cell function, the morphologic changes of the pancreatic islets were observed by optical microscope and immunofluorescence of hormones(insulin and glucagon). Pancreatic protein expression levels of key factors involving in insulin secretion-related pathway and ER stress were also detected by Western blot. Pre-diabetic KKAy mice exhibited a compensatory augment in β cell mass and abnormal α cell distribution. Long-term treatment of JTN recovered islet morphology accompanied by reducing α cell area in KKAy mice. JTN upregulated expression levels of glucokinase(GCK), pyruvate carboxylase(PCB) and pancreas duodenum homeobox-1(PDX-1), while down-regulating C/EBP homologous protein(Chop)expression in pancreas of the hyperglycemic clamp, which indicated the improvement of mitochondrial metabolism and relief of endoplasmic reticulum(ER) stress of β cells after JTN treatment. These results will provide a new insight into exploring a novel strategy of JTN for protecting β cell function and preventing the onset of pre-diabetes to T2 DM.展开更多
注射用艾塞那肽-人血清白蛋白融合蛋白(injectable recombinant protein of exendin-4 and human serum albumin,E2HSA)是我国自主研发的一种长效胰高血糖素样肽-1(glucagon-like peptide-1,GLP-1)受体激动剂,目前处于临床研究阶段。本...注射用艾塞那肽-人血清白蛋白融合蛋白(injectable recombinant protein of exendin-4 and human serum albumin,E2HSA)是我国自主研发的一种长效胰高血糖素样肽-1(glucagon-like peptide-1,GLP-1)受体激动剂,目前处于临床研究阶段。本研究在细胞和整体动物水平研究E2HSA对胰岛β细胞的保护作用。在细胞水平,采用小鼠胰岛素瘤细胞株NIT-1考察E2HSA对细胞活力和增殖的影响;采用水溶性胆固醇诱导NIT-1细胞损伤,考察E2HSA对细胞活力和凋亡的影响,并研究其相关作用机制。在整体动物水平,采用四氧嘧啶高血糖小鼠考察长期注射E2HSA对血糖、血胰岛素和胰岛内胰岛素含量的影响。动物实验操作和福利均遵循中国医学科学院、北京协和医学院药物研究所实验动物伦理与动物福利委员会的规定。结果显示,E2HSA可明显增加NIT-1细胞的活力和掺入的溴脱氧尿嘧啶核苷(bromodeoxyuridine,BrdU);同时显著增加水溶性胆固醇诱导NIT-1细胞损伤后的细胞活力,减少其凋亡发生率,并增加胞内胰腺-十二指肠同源框1(pancreatic duodenal homeobox-1,PDX-1)和蛋白激酶B(protein kinase B,PKB)蛋白的表达。E2HSA长期注射可明显降低四氧嘧啶小鼠的空腹血糖和非禁食血糖,增加其血清和胰岛内的胰岛素含量。综上,E2HSA可以促进NIT-1细胞增殖,抑制水溶性胆固醇诱导的细胞损伤和凋亡,同时增加四氧嘧啶高血糖小鼠血清和胰岛内的胰岛素水平,提示E2HSA可改善小鼠胰岛β细胞功能。展开更多
基金supported by the Drug Innovation Major Project in China (Nos. 2018ZX09711001-003-011 and 2018ZX09711-001-009-014)the National Natural Science Foundation of China (No. 81973379)the Natural Science Foundation of Beijing Municipality (No. 7202137)。
文摘Jin-tang-ning(JTN), a Chinese patent medicine, mainly comprised of Bombyx mori L., has been proved to show α-glucosidase inhibitory efficacy and clinically effective for the treatment of type 2 diabetes(T2 DM). Recently, we have reported that JTN could ameliorate postprandial hyperglycemia and improved β cell function in monosodium glutamate(MSG)-induced obese mice,suggesting that JTN might play a potential role in preventing the conversion of impaired glucose tolerance(IGT) to T2 DM. In this study, we evaluated the effect of JTN on the progression of T2 DM in the pre-diabetic KKAy mice. During the 10 weeks of treatment,blood biochemical analysis and oral glucose tolerance tests were performed to evaluate glucose and lipid profiles. The β cell function was quantified using hyperglycemic clamp at the end of the study. JTN-treated groups exhibited slowly raised fasting and postprandial blood glucose levels, and also ameliorated lipid profile. JTN improved glucose intolerance after 8 weeks of treatment. Meanwhile, JTN restored glucose-stimulated first-phase of insulin secretion and induced higher maximum insulin levels in the hyperglycemic clamp.Thus, to investigate the underlying mechanisms of JTN in protecting β cell function, the morphologic changes of the pancreatic islets were observed by optical microscope and immunofluorescence of hormones(insulin and glucagon). Pancreatic protein expression levels of key factors involving in insulin secretion-related pathway and ER stress were also detected by Western blot. Pre-diabetic KKAy mice exhibited a compensatory augment in β cell mass and abnormal α cell distribution. Long-term treatment of JTN recovered islet morphology accompanied by reducing α cell area in KKAy mice. JTN upregulated expression levels of glucokinase(GCK), pyruvate carboxylase(PCB) and pancreas duodenum homeobox-1(PDX-1), while down-regulating C/EBP homologous protein(Chop)expression in pancreas of the hyperglycemic clamp, which indicated the improvement of mitochondrial metabolism and relief of endoplasmic reticulum(ER) stress of β cells after JTN treatment. These results will provide a new insight into exploring a novel strategy of JTN for protecting β cell function and preventing the onset of pre-diabetes to T2 DM.
文摘注射用艾塞那肽-人血清白蛋白融合蛋白(injectable recombinant protein of exendin-4 and human serum albumin,E2HSA)是我国自主研发的一种长效胰高血糖素样肽-1(glucagon-like peptide-1,GLP-1)受体激动剂,目前处于临床研究阶段。本研究在细胞和整体动物水平研究E2HSA对胰岛β细胞的保护作用。在细胞水平,采用小鼠胰岛素瘤细胞株NIT-1考察E2HSA对细胞活力和增殖的影响;采用水溶性胆固醇诱导NIT-1细胞损伤,考察E2HSA对细胞活力和凋亡的影响,并研究其相关作用机制。在整体动物水平,采用四氧嘧啶高血糖小鼠考察长期注射E2HSA对血糖、血胰岛素和胰岛内胰岛素含量的影响。动物实验操作和福利均遵循中国医学科学院、北京协和医学院药物研究所实验动物伦理与动物福利委员会的规定。结果显示,E2HSA可明显增加NIT-1细胞的活力和掺入的溴脱氧尿嘧啶核苷(bromodeoxyuridine,BrdU);同时显著增加水溶性胆固醇诱导NIT-1细胞损伤后的细胞活力,减少其凋亡发生率,并增加胞内胰腺-十二指肠同源框1(pancreatic duodenal homeobox-1,PDX-1)和蛋白激酶B(protein kinase B,PKB)蛋白的表达。E2HSA长期注射可明显降低四氧嘧啶小鼠的空腹血糖和非禁食血糖,增加其血清和胰岛内的胰岛素含量。综上,E2HSA可以促进NIT-1细胞增殖,抑制水溶性胆固醇诱导的细胞损伤和凋亡,同时增加四氧嘧啶高血糖小鼠血清和胰岛内的胰岛素水平,提示E2HSA可改善小鼠胰岛β细胞功能。
