TLR2/NLRC5参与棕榈酸诱导的心肌细胞凋亡及相关机制研究

TLR2/NLRC5 involved in palmitate acid-induced apoptosis in H9C2 and the relative mechanism research

目的:建立棕榈酸(palmitate acid,PA)诱导体外培养心肌细胞胰岛素抵抗(insulin resistance,IR)及凋亡模型,检测Toll样受体2(TLR2)和NLRC5在此模型中的表达变化及研究相关的可能机制。方法:用500μmol/L终浓度的PA处理培养H9C2心肌细胞后采用AnnexinⅤ/PI双染和流式细胞术分析细胞凋亡情况,并分别采用q-PCR及Western blot方法分析处理后细胞的胰岛素受体(InsR)、CD36、PGC-1α、TLR2、NLRC5、SIRT1、p-AMPK/AMPK的mRNA或蛋白表达变化。结果:与对照组比较,PA处理24 h后H9C2细胞的早、晚期和总凋亡率显著升高,分别为(7.55±3.80)%、(53.84±4.70)%和(61.39±8.54)%(P<0.05);处理6 h后心肌细胞的PGC-1αmRNA相对表达量开始下降(P<0.05),TLR2和NLRC5则显著升高(P<0.01),CD36mRNA相对表达量在PA处理14 h时升高(P<0.05);InsR、SIRT1和AMPK蛋白相对表达量从PA处理8 h时开始下降,差异均有统计学意义(P<0.05)。结论:TLR2/NLRC5参与PA诱导的心肌细胞IR和凋亡,并且可能与AMPK/SIRT1/PGC-1α信号通路的活性下降有关。

AIM： To establish a model of palmitate acid（ PA） induced-insulin resistance（ IR）and apoptosis in in-vitro cultured cardiomyocyte,detect the change of the expression of Toll-like receptor2（ TLR2） and NLRC5 in the model and investigate the possible relative mechanisms. METHODS：Cultured H9C2 cells were treated with 500 μmol / L PA and then the apoptosis ratio of cells measured through Annexin-Ⅴ-PI double staining assay on flow cytometry,and the expression level of mRNA or protein of InsR, CD36, PGC-1α, TLR2, NLRC5,SIRT1,p-AMPK / AMPK of cells were detected by q-PCR or western blotting respectively. RESULTS：Compared with the control,the ratio of the total,early and late apoptosis of H9C2 after PA 24 h treatment were all significantly increased with the amount of（ 7. 55 ± 3. 80） %,（ 53. 84 ± 4. 70） % and（ 61. 39 ± 8. 54） % respectively（ P〈0. 05）. In model cells,after 6 h treatment of PA,the mRNA relative expression of PGC-1α began to decrease（ P〈0. 05）,while TLR2 and NLRC5 increased（ P〈0. 01）; mRNA relative expression of CD36 increased after 14 h treatment（ P〈0. 05）; the protein relative expression of InsR,SIRT1 and AMPK of model all decreased from 8 h PA treated（ P〈0. 05）. CONCLUSION： TLR2 / NLRC5 involved in the cardiomyocyte insulin resistance and apoptosis induced by palmitate acid,and may also be relative to the descending activity of p-AMPK / SIRT1 / PGC-1α signaling pathway.