软脂酸对HIT-T15细胞线粒体形态功能和胰岛素分泌的影响

The effect of paimitate on mitochondrial morphology and function and insulin secretion of HIT-T15 cell

目的观察软脂酸(PA)对HIT-T15细胞凋亡、线粒体结构和功能及胰岛素分泌的影响并探讨可能的机制。方法试验分对照组、0.5mmol/L PA和1.0mmol/LPA组,透射电镜观察细胞及线粒体形态,流式细胞仪(FC)和原位末端标记法(TUNEL)检测凋亡率,高效液相色谱法(HPLC)检测细胞ATP/ADP,RT-PCR检测过氧化物酶体增殖物激活受体γ共激活因子1(PGC-1)和核呼吸因子1(NRF-1)mRNA,放免法测基础和葡萄糖刺激后胰岛素分泌(GSIS)。结果 PA能使线粒体肿胀、嵴破坏;细胞的凋亡率增加,且FC检测高浓度PA组凋亡率增加更显著;ATP/ADP比率下降;PGC-1mRNA和NRF-1mRNA表达增加,高浓度PA组增加更显著;GSIS下降(P均<0.05)。结论 PA导致HIT-T1 5细胞的线粒体结构和功能的损害及GSIS下降,可能与PGC-1和NRF-1的调节作用有关。

Objective To investigate the effect of palmitate（PA） on mitochondrial ultrastructure, apoptosis and insulin secretion of HIT-T15 cell and explore the possible mechanism. Methods There were 3 groups： control group, 0. 5mmol/L and 1.0mmol/L PA group. Mitochondrial ultrastructure, apotosis, ATP/ADP ratio, PGC-1 mRNA, NRF-1 mRNA and insulin secretion were detected. Results PA made cells and mitochondria swollen which were showed by electron-microscope. As detected by flow eytometer and TUNEL respectively, apoptosis increased in 0. 5mmol/L PA[9.73 %±0.38% （P（0. 05）, 8.31%±0.32% （P〈0.05）] and in 1.0mmol/L PA（12.97%±0.73%（P（0. 05） ,10. 80%±0. 27%（P〈 0.05） versus control（7.40 %± 0. 96 %, 5.93 %± 0.56 % ）. PA decreased ATP/ADP ratio from 3.15±1.14 of control to 0. 70±0.14 of 0.5mmol/L PA（P（0.05） and 0. 41±0. 08 of 1.0mmol/L PA（P（0. 05）. PA could increase the expression of NRF-1 mRNA and PGC-1 mRNA. There were increased expressions of NRF-1 mRNA in 0.5mmol/L PA with 1.94±0.91 vs in control with 0. 83±0. 28; and of PGC-1 mRNA in 0. 5mmol/L PA with 2. 36±0. 81 vs in control with 0.81±0. 16, and in 1.0mmol/L PA with 4. 16±1.42（P〈 0.05）respectively. GSIS were decreased from 1.03±0. 20 /μg/L of control to 0. 35 ±0. 05μg/L of 0. 5mmol/L PA （P〈0.05）and 0.07 ± 0.00μg/1 of 1.0mmol/L PA （P（0.05）. Conclusions PA could damage mitoehondrial ultrastructure and decrease GSIS of 13 cell,which are possibly regulated by PGC-1 and NRF-1.