生物素对高糖状态下大鼠胰岛β细胞功能的影响

The effect of biotin on the function of rat islet β cell cultured with high glucose

目的探讨生物素对高糖损伤胰岛β细胞功能的影响。方法采用Dextran密度梯度离心法分离纯化大鼠胰岛,在含5.5mmol·L-1葡萄糖、5.5mmol·L-1葡萄糖+1μmol·L-1生物素、含27.0mmol·L-1葡萄糖及27.0mmol·L-1葡萄糖+1μmol·L-1生物素的RPMI1640培养基中培养48h,分析3.3、27.0mmol·L-1葡萄糖刺激的胰岛素分泌及胰岛细胞中胰岛素的含量;提取总mRNA,RT-PCR扩增前胰岛素源基因,电泳并进行灰度分析。结果在5.5mmol·L-1葡萄糖培养条件下,生物素增加高糖诱导的胰岛素释放及胰岛细胞的胰岛素含量,前胰岛素源mRNA也增加;在27.0mmol·L-1葡萄糖培养48h的胰岛中,胰岛细胞中的胰岛素浓度降低,高糖诱导的胰岛素释放及前胰岛素源mRNA显著减少;生物素的共培养,部分提高了高糖诱导的胰岛素释放及前胰岛素源mRNA含量。结论生物素通过促进胰岛素的合成显著改善了高糖损伤胰岛β细胞的功能紊乱。

OBJECTIVE To explore the effect of biotin on β cell dysfunction induced by high glucose. METHODS Rat islet were isolated and purified by the method of Dextran density - gradient centrifugation. Culture were performed in RPMI 1640 containing with 5.5 mmol·L^-1 glucose, 5.5 mmol·L^-1 glucose and 1 μmol·L·L^-1 biotin,27.0 mmol·L^-1 glucose,27. 0 mmol·L^-1 glucose and 1 μmol·L·L^-1 biotin. Islets were cultured for 48 h. Glucose - induced insulin release and insulin content in islet cells were determinated. Total RNA was extracted by the TRIzol isolation method. Preproinsulin gene were amplified by RT- PCR and PCR products were tested on agarose gels. Signals were quantified. RESULTS In islets cultured with 5.5 mmol·L^-1 glucose for 48 h, biotin significantly enhanced glucose - induced insulin release and cellular insulin content. Preproinsulin mRNA was also enhanced. In islets cultured with 27.0 mmol·L^-1 glucose, cellular insulin content, preproinsulin mRNA and glucose - induced insulin release deteriorated. Co - culture with biotin significantly restored glucose - induced insulin release and cellular insulin content together with the restoration of preproinsulin mRNA. CONCLUSION Biotin significantly improved 13 cell dysfunction induced by high glucose probably through the enhancement of insulin biosynthesis.