特异性转录因子在正常小鼠和糖尿病小鼠胰岛内的表达及其意义

Expression and significance of the specialized transcription factors within the pancreatic islets of normal and diabetic mice

目的探讨正常小鼠与糖尿病小鼠胰腺组织病理学特征的异同及其意义。方法正常C57BL／6小鼠作为对照组（n=4），腹腔内注射链脲霉素（STZ）的C57BL／6小鼠作为STZ组（n=8），非肥胖性糖尿病（NOD）小鼠作为NOD组（n=2）。观察各组小鼠胰腺组织苏木素-伊红（HE）染色特点；应用免疫荧光技术观察特异性标记物在各组小鼠胰腺组织中的表达情况。结果STZ、NOD组小鼠与对照组小鼠比较，HE染色：胰岛数目明显减少；免疫荧光染色：胰岛中Insulin^＋细胞与Glucagon^＋细胞数量比例倒置，Nkx2．2和Nkx6．1的表达均减少，STZ组小鼠胰岛中有少量Ngn3^＋细胞及Insulin^＋Glucagon^＋细胞。结论糖尿病小鼠血糖升高可能是由于B细胞和仅细胞数量的比例倒置所致；成体小鼠胰腺中有干细胞样特性的细胞存在；Nkx2．2需要其他转录因子的参与才能使胰岛内分泌前体细胞生成成熟B细胞。

Objective To investigate the differences in histopathological features in pancreatic tissues between normal mice and diabetic mice. Methods Selected normal C57BL/6 mice as control group （n = 4 ） , STZ-treated group mice were created by peritoneal injection of STZ （n = 8 ） , Selected NOD mice （n =2） as NOD group. Histochemistry and immunofluoreseent were performed to characterize pancreatic histology, morphology and markers expressed in receipt pancreas. Results HE staining：The quantity of the pancreatic islets of the diabetic mice was obviously decreased. Immunofluorescence staining：the ratio between Insulin-positive cells and Glucagon-positive cells was inverted in the pancreata of diabetic mice. Both Nkx2.2 and Nkx6.1 expressed less in the pancreata of diabetic mice. There were a few Ngn3^＋ cells and Insulin^＋ Glucagon^＋ cells in the pancreata of STZ treated mice. Conclusion The inversion of the ratio between β and α cells leads to hyperglycemia in diabetic mice. There are putative stem cells in adult pancreas. Nkx2.2 probably needs the help of certain transcription factors which make endocrine progenitor cells differentiate into mature β cells.