番石榴酸改善INS-1胰岛β细胞胰岛素抵抗

Effect of guavenoic acid on improving insulin resistance in INS-1 cells and its mechanisms

目的考察番石榴酸对INS-1胰岛β细胞胰岛素抵抗的作用,并探讨其可能的作用机制。方法 40 mmol/L葡萄糖干预INS-1胰岛β细胞48 h建立胰岛素抵抗模型,设番石榴酸干预组(0.3、1、3、10、30 nmol/L),以及空白对照组、二甲亚砜对照组,胰岛素抵抗模型组,正钒酸钠组(1 mmol/L)和罗格列酮组(1 mmol/L),药物作用48 h。分别以5.6、16.7 mmol/L葡萄糖干预细胞1 h作为基础胰岛素分泌(BIS)、高糖刺激胰岛素分泌(GSIS)条件,用放射免疫法检测药物对胰岛素分泌的影响,结果以该细胞总蛋白量校正。荧光定量PCR法检测药物对胰岛素抵抗INS-1细胞内PTP1B、PPARγmRNA表达的作用。结果与胰岛素抵抗模型组比较,0.3 nmol/L番石榴酸便能促进胰岛素抵抗INS-1细胞的GSIS(P<0.05或P<0.01);1 nmol/L番石榴酸即可显著促进基础胰岛素分泌(P<0.01)。0.3、3、30 nmol/L番石榴酸均能显著下调胰岛素抵抗INS-1细胞的PTP1B mRNA相对表达(P<0.05或P<0.01),其中0.3和3 nmol/L番石榴酸下调作用优于正钒酸钠,上调PPARγmRNA相对表达作用优于罗格列酮。结论番石榴酸能够改善INS-1细胞胰岛素抵抗,可能通过下调PTP1B和上调PPARγ基因表达有关。番石榴酸可能通过改善胰岛β细胞自身胰岛素抵抗而发挥抗糖尿病作用。

AIM To investigate the improvement effect of guavenoic acid（ GA） on insulin resistance in INS-1cells and its possible mechanism. METHODS 40 mmol / L glucose caused stimulation to INS-1 cells in vitro for48 h to establish the insulin resistance model（ IR）. These INS-1 cells were assigned into guavenoic acid groups（ 0. 3,1,3,10,30 nmol/L）,DMSO group,the IR group,sodium orthoranadate group（ 1 mmol/L）,Rosiglitazone group（ 1 mmol / L）,and the control group,then 5. 6,16. 7 mmol / L glucose were used to challenge INS-1cells for 1h,respectively,to test their basal insulin secretion（ BIS） and glucose stimulated insulin secretion（ GSIS）. The influence of test drugs to insulin secretion was calculated by radioimmunology and was calibrated by total proteins in cells. The mRNA expressions of PTP1 B and PPARγ were measured by q-PCR. RESULTS Compared with the model group,guavenoic acid（ 0. 3 nmol / L） could promote GSIS of insulin resistance INS-1 cells（ P〈 0. 05 or P〈 0. 01）; guavenoic acid（ 1 nmol/L） played a significant role in the promotion of BIS（ P〈 0. 01）. Compared with the model group,guavenoic acid（ 0. 3,3,and 30 nmol / L） could significantly decrease relative expression of PTP1 B mRNA in insulin resistance INS-1 cells（ P〈 0. 05 or P〈 0. 01）. Downward effect of guavenoic acid（ 0. 3 and 3 nmol / L） was better than that of sodium orthovanadate; the increment of relative expression of PPARγ mRNA by guavenoic acid（ 0. 3 and 3 nmol / L） was more than that of Rosiglitazone. CONCLUSION Guavenoic acid can significantly improve the insulin resistance of INS-1 cells,which may be related to the down-regulation of PTP1 B gene expression and up-regulation of PPARγ gene expression.