O-GlcNAc糖基化修饰介导的小檗碱抗II型糖尿病胰岛素抵抗机制研究

Traditional Chinese medicine (TCM) indicates that Yin Xu Zao Re is the core mechanism of diabetes. Thus, in the compatibility for TCM clinical treatment of type II diabetes, Qing Re Liang Xue herb is pretty common, and have achieved a certain effect, such as Scutellaria baicalensis, rhizoma coptidis and cortex phellodendron chinensis. Berberine is a common effective compound of these three Chinese herbs. Plenty reports have clarified the efficacy and pharmacological effects of berberine in the treatment of type II diabetes in recent years, however, it is limited known about the mechanism of Berberine works. O-GlcNAcylation is a dynamic, reversible post-translational modification. It has been found that the level of O-GlcNAc modification on insulin resistance related proteins, including IRS, is significantly aberrant in type II diabetes mellitus. In our previous study, we found that berberine down-regulated the global O-GlcNAc modification level in HepG2 cells, suggesting berberine-mediated the reduction of O-GlcNAc modification may be related with the mechanism of berberine effects on type II diabetes. In this project, we will establish the model of HepG2 insulin resistance cells and type II diabetes rats, combined with molecular biology and biochemistry experiments, aim to clarify the mechanism of O-GlcNAcylation mediated berberine effects on type II diabetes. Providing the theoretical basis for the compatibility in the treatment of clinical diabetes mellitus of berberine.

传统中医学认为阴虚燥热是糖尿病发病的核心机制，清热凉血类中药黄芩、黄连、黄柏在中医临床治疗II型糖尿病的组方中十分常见，并取得了一定疗效。小檗碱是上述中药的共同有效成分。近年来有关小檗碱治疗II型糖尿病的药效和药理作用报道越来越多，但是有关其作用机理知之甚少。O-GlcNAc修饰是一种动态、可逆的翻译后修饰，已发现在II型糖尿病细胞/组织中胰岛素抵抗相关蛋白的O-GlcNAc修饰水平明显异常。我们在前期研究中发现用小檗碱处理HepG2细胞可致全细胞O-GlcNAc修饰水平下调，提示小檗碱介导的O-GlcNAc修饰水平的降低可能与其治疗II型糖尿病的作用机理有关。本项目将以经典的HepG2细胞胰岛素抵抗模型及II型糖尿病大鼠动物模型为研究对象，结合分子生物学实验方法，研究O-GlcNAc修饰介导的小檗碱治疗II型糖尿病的分子机制，为小檗碱的临床用药提供理论基础。

中药黄连在中医临床治疗II型糖尿病（T2DM）的组方中十分常见。Berberine是黄连的主要药效物质，具有抗炎、降血脂、降糖等多种药理作用。本项目通过网络药理学分析阐明黄连-T2DM、Berberine-T2DM的靶蛋白及其相互作用网络，揭示Berberine通过调控多靶点及相关生物学过程和信号通路治疗T2DM。并在体外建立胰岛素抵抗HepG-2、C2C12细胞模型，结合葡萄糖消耗、糖原合成及免疫印迹等试验方法，在细胞水平揭示Berberine显著改善了棕榈酸诱导的胰岛素抵抗细胞葡萄糖消耗、糖原合成、胰岛素敏感性（phAKT/panAKT比值）、葡萄糖转运以及糖异生等糖代谢过程，并靶向O-GlcNAc糖基化修饰酶OGT催化结构域，以剂量依赖的方式抑制OGT蛋白水平，从而下调HepG-2细胞O-GlcNAc修饰，进而缓解胰岛素抵抗。阐明Berberine治疗T2DM的分子机制。另一方面，蛋白质组学结合大数据分析揭示Berberine-HepG-2蛋白质组学分析揭示Berberine对细胞周期、细胞凋亡的调控作用，提示Berberine抗肿瘤的潜在药理学活性。为课题组后续研究Berberine靶向O-GlcNAc-乙酰基化修饰治疗肿瘤提供数据基础。目前已发表相关研究论文1篇，在投论文1篇；培养硕士研究生2名。