Wnt信号通路对体外培养小鼠胰岛β细胞的影响

Influence of Wnt signaling pathway on mouse NIT-1 β-ceil cultured in vitro

目的研究Wnt信号通路对体外培养的小鼠NIT-1胰岛细胞增殖和凋亡的影响。方法高糖或细胞因子诱导胰岛细胞损伤，给予Wnt3a蛋白孵育，激活Wnt通路。Tunnel及流式细胞术检测细胞凋亡，BrdU检测细胞增殖。实时定量PCR检测同源异型结构域蛋白转录因子2（Pitx2）、T细胞特异性转录因子7类似物2（TCF7L2）mRNA的表达。结果Wnt蛋白干预组细胞的凋亡减少（P〈0．01），增殖增加，促进增殖的相关基因表达上调。结论激活Wnt通路能促进胰岛细胞的增殖及减少其凋亡。

Objective To establish whether Wnt-signaling pathway plays a role in mice β-cell function and/or survival in vitro. Methods Mice NIT-1 beta cells were cultured in media with glucose concentration of 33.3 mmol/L and the cytokines interleukin-1β, interferon-yand tumor necrosis factor-or with or without the addition of purified Wnt3a protein in vitro. Subsequently, β-cell apoptosis by Tunnel and flow cytometry, and β-cell proliferation by BrdU were analyzed. Total RNA was extracted to measure gene expressions by real-time PCR. Results Incubations of NIT-1 ceils with high glucose and cytokines resulted in an increase in B-cell apoptosis and decrease in β-cell proliferation （P〈0. 01 ）. In contrast, treatment with Wnt3a protein protected β-cell from glucose and cytokines-induced apoptosis through up-regulating the expressions of above Pitx2, TCF7L2. Conclusions Wnt-signaling regulates the proliferation of pancreatic β-cell, and protectes β-cell from glucotoxicity and cytokine toxicity with respect to proliferation and apoptosis.