He Guigui, Wang Liuli, Jing Gaojing, Cen Mengjia, Zhao Nan, Tang Xulei
First Clinical Medical College, Lanzhou University, Lanzhou 730000, China.
Endocrinology Department of the First Hospital, Lanzhou University, Lanzhou 730000, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2022 May;38(5):385-390.
Objective To investigate the molecular mechanism of palmitic acid (PA) inducing inflammation and epithelial to mesenchymal transdifferentiation (EMT) in human renal tubular epithelial cells (RTECs). Methods The cell lipid accumulation model was prepared by RTECs and the cells were divided into blank control group, bovine serum albumin (BSA) group, PA group, and PA combined with stimulator of interferon genes (STING) specific inhibitor H151 group. The lipid accumulation of RTECs were detected by oil red O staining. Real-time quantitative PCR was used to detect the mRNA levels of interleukin 6 (IL-6), IL-8, transforming growth factor β1 (TGF-β1), and type 1 collagen alpha 1 chain (COL1A1) in RTECs. The protein expressions of STING, nuclear factor-κB p65 (NF-κB p65), phosphorylated NF-κB p65 (p-NF-κB p65), TGF-β1, and type 1 collagen (Col1) were detected by Western blot and the expression and distribution of Col1 in RETCs were detected by immunofluorescence chemical staining. Results Compared with the control group, PA stimulated the lipid deposition, the expression of STING, and the phosphorylation of NF-κB p65 obviously, up-regulated the mRNA levels of IL-6, IL-8, TGF-β1, and COL1A1 significantly, increased the protein expressions of TGF-β1 and Col1 and the distribution of Col1 in RTECs; compared with those in the PA group, after H151 treatment, the expression of STING and the phosphorylation of NF-κB p65 decreased notably, the mRNA levels of IL-6, IL-8, TGF-β1, and COL1A1 were down-regulated dramatically, and the protein expressions of TGF-β1 and Col1 declined with reduced distribution of Col1. Conclusion PA induces lipid deposition, activated the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)/STING pathway, and caused inflammation and EMT in RTECs.
目的 探讨棕榈酸（PA）诱导人肾小管上皮细胞（RTECs）发生炎症及上皮-间质转化（EMT）的分子机制。方法 用RTECs制备细胞脂质蓄积模型，将细胞分为空白对照组、牛血清白蛋白（BSA）组、PA组、PA联合干扰素基因刺激因子（STING）特异性抑制剂H151组。采用油红O染色检测RTECs的脂质蓄积情况。运用实时定量PCR检测RTECs中白细胞介素6（IL-6）、IL-8、转化生长因子β1（TGF-β1）及Ⅰ型胶原α1链（COL1A1）的mRNA水平。通过蛋白质免疫印迹法检测STING、核因子κB p65（NF-κB p65）、磷酸化NF-κB p65（p-NF-κB p65）、TGF-β1及Ⅰ型胶原（Col1）的蛋白表达，采用免疫荧光化学染色检测Col1在RETCs中的表达及分布。结果 与对照组相比，PA明显促进脂质沉积、STING表达及NF-κB p65磷酸化，显著上调IL-6、IL-8、TGF-β1及COL1A1的mRNA水平，增加TGF-β1和Col1的蛋白表达及Col1在RTECs中的分布；与PA组相比，H151处理后，STING表达及NF-κB p65磷酸化明显降低，IL-6、IL-8、TGF-β1及COL1A1的mRNA水平显著下调，TGF-β1和Col1的蛋白表达下降，Col1分布减少。结论 PA诱导脂质沉积，激活环磷酸鸟苷-磷酸腺苷合成酶（cGAS）/STING通路，导致RTECs发生炎症及EMT。
