运用数字基因表达图谱技术进行胰岛β细胞糖毒性发病机制的研究

Apoptosis of pancreatic beta cells and impairment of insulin secretion caused by hyperglycemia play an important role in the development and progression in type 2 diabetes. Endoplasmic reticulum stress not only induces the adaptive response to high level of glucose,but also results in apoptosis and dysfunction in pancreatic beta cells. By using high thapsigargin,or by inducing the expression of dominant negative mutant of XBP-1 in INS-1 cells， we will build different endoplasmic reticulum stress models and compare their cellular effects with the effect of high level of glucose;in parellel,we will use K-ATP channel openner（Dizoxide）in INS-1 cells to prevent endoplasmic reticulum stress induced by high level of glucose. By using digital gene expression technology, we will analyze the global gene expression. We will evaluate the effect of these mentioned treatments on apoptosis/proliferation and insulin secretion of INS-1 cells.Consequently,we aim to clarify the signal pathway involved in endoplasmic reticulum stress in glucotoxicity. Finally we hope make a progess in understanding the mechanism of endoplasmic reticulum stress in glucotoxicity and in finding potential targets for prevention of glucotoxicity.

高血糖导致的胰岛β细胞凋亡和胰岛素分泌障碍在2型糖尿病的发生和发展中发挥重要作用。β细胞内质网应激既是细胞对高血糖的适应性反应，也是导致细胞凋亡和功能衰竭的重要因素。通过毒胡萝卜素和通过建立强力土霉素可诱导的INS-1细胞系显性抑制表达XBP-1基因诱导内质网应激并与高浓度葡萄糖培养比较；同时采用K-ATP 通道开放剂二氮嗪预防高浓度葡萄糖导致内质网应激；利用数字基因表达图谱技术，分析不同实验条件下全基因组表达的差别，并通过集群分析、功能富集分析和通路分析方法，探索糖毒性发生和缓解所涉及的主要信号通路或分子与不同方式导致内质网应激的异同。本课题有助于揭示人类胰岛糖毒性发生的机制及探索可能的防治途径。

高血糖导致的胰岛β细胞凋亡和胰岛素分泌障碍在2型糖尿病的发生和发展中发挥重要作用。β细胞内质网应激既是细胞对高血糖的适应性反应，也是导致细胞凋亡和功能衰竭的重要因素。本课题在INS-1细胞系中通过糖毒性、糖脂毒性、毒胡萝卜素、衣霉素和促进胰岛素分泌的格列苯脲诱导内质网应激；同时，利用K-ATP通道开放剂二氮嗪、化学伴侣分子牛磺熊去氧胆酸和4-苯基丁酸钠盐预防糖脂毒性导致的内质网应激。利用数字基因表达图谱技术的通路分析，我们发现糖毒性、糖脂毒性，毒胡萝卜素和衣霉素都可以导致MODY通道上的基因表达改变,其中NKX6.1 和MNX1表达下降。同时，二氮嗪、化学伴侣分子牛磺熊去氧胆酸和4-苯基丁酸钠盐可阻止相关基因的下调。研究结果提示MODY通路相关的转录因子在糖尿病发生发展过程中发挥重要作用，为糖尿病治疗提供新的靶点。