Department of Endocrinology and Metabolism, University of Pisa, Ospedale Cisanello, Italy.
Diabetes Metab. 2009 Sep;35(4):293-8. doi: 10.1016/j.diabet.2009.01.004. Epub 2009 Jun 6.
To evaluate the effects of exposure to high glucose (HG) levels and sulphonylurea on isolated human islet-cell function, and to investigate some of the mechanisms that might be involved.
Islet cells were isolated, using collagenase digestion and gradient purification, from 13 pancreata from non-diabetic multiorgan donors (age: 61.2+/-11.5 years; gender: 7 men/6 women; body mass index: 25.1+/-2.8kg/m(2)). The cells were then cultured for 5 days with normal glucose (NG) concentrations (5.5mmol/L), or NG and HG (16.7mmol/L) levels (alternating every 24h), with or without the addition of therapeutic concentrations of gliclazide (10micromol/L) or glibenclamide (1.0micromol/L). At the end of incubation, functional (glucose-stimulated insulin secretion), morphological (electron microscopy) and molecular (gene and protein expression) studies were performed.
Insulin secretion differed significantly between study groups, with marked decreases in the presence of HG plus glibenclamide. Compared with NG, insulin expression decreased significantly with HG, and increased similarly with gliclazide as with glibenclamide. However, exposure to gliclazide, but not glibenclamide, significantly induced expression (at both gene and protein levels) of PDX-1, a fundamental beta-cell differentiation transcription factor, and Ki67, a marker of proliferation. However, gliclazide and glibenclamide did not differ in terms of effects on gene expression of the antiapoptotic molecule Bcl2 (increased significantly with both) and the proapoptotic molecule Bax (decreased significantly with both).
Gliclazide and glibenclamide have different effects on the changes induced by prolonged exposure of human islet cells to high levels of glucose.
评估高糖（HG）水平和磺酰脲类药物暴露对分离的人胰岛细胞功能的影响，并研究可能涉及的一些机制。
使用胶原酶消化和梯度纯化法从 13 例非糖尿病多器官供体的胰腺中分离胰岛细胞（年龄：61.2±11.5 岁；性别：7 男/6 女；体重指数：25.1±2.8kg/m(2)）。然后将细胞在正常葡萄糖（NG）浓度（5.5mmol/L）或 NG 和 HG（16.7mmol/L）水平（每 24 小时交替）下培养 5 天，加入或不加入治疗浓度的格列齐特（10µmol/L）或格列本脲（1.0µmol/L）。孵育结束时，进行功能（葡萄糖刺激的胰岛素分泌）、形态学（电子显微镜）和分子（基因和蛋白表达）研究。
胰岛素分泌在研究组之间有显著差异，HG 加格列本脲存在时明显减少。与 NG 相比，HG 使胰岛素表达显著降低，而格列齐特与格列本脲相似地增加。然而，与 NG 相比，与格列本脲相比，格列齐特暴露显著诱导 PDX-1（一种基本的β细胞分化转录因子）和 Ki67（增殖标志物）的表达增加（在基因和蛋白水平上）。然而，格列齐特和格列本脲在抗凋亡分子 Bcl2（均显著增加）和促凋亡分子 Bax（均显著减少）的基因表达方面的作用没有差异。
格列齐特和格列本脲对人胰岛细胞长期暴露于高糖水平引起的变化有不同的影响。
