Identification of the beta cells and demonstration of telomere shortening in diabetes mellitus by the tissue Q-FISH method

在2型糖尿病中，β细胞减少导致葡萄糖耐量功能障碍。端粒与恶性肿瘤或老年疾病有关。应用组织Q-FISH技术对47例2型糖尿病患者和104例正常对照者的胰腺石蜡包埋切片进行检测。测量并比较胰腺各细胞群的端粒长度。胰高血糖素和胰岛素的免疫荧光叠加研究显示胰岛α和β细胞的端粒长度在神经细胞中最长，在导管中比外分泌腺或内分泌腺长。在糖尿病患者中，几乎所有细胞组的端粒都比对照组短，但以β细胞最为突出。提示β细胞端粒缩短与2型糖尿病的发生有关。

In type 2 diabetes, reduction of beta cells causes dysfunction of the glucose tolerance. Telomere is related to malignant neoplasms or geriatric diseases. Therefore, we predicted that telomeres of beta cells should be shorten selectively in diabetic pancreas.Tissue Q-FISH method was applied to paraffin-embedded pancreatic sections from autopsy cases (type 2 diabetes 47 cases and control 104 cases). Telomere lengths of each cell group of the pancreas were measured and compared. Alpha and beta cells in pancreatic islets were distinguished by superimposed immunofluorescence study for glucagon and insulin.Telomere lengths were longest in the nerve cells, and longer in ducts than exocrine or endocrine glands. In the diabetic cases, almost cell group showed shorter telomeres than the controls, but most prominent especially in beta cells. Therefore, it is suggested that telomere shortening in beta cells has relevance to occurrence of type 2 diabetes.