Dong Zhixia, Zhuang Qian, Ning Min, Wu Shan, Lu Lungen, Wan Xinjian
Digestive Endoscopic Center, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China.
Ann Transl Med. 2020 Mar;8(5):168. doi: 10.21037/atm.2020.02.21.
The NLRP3 inflammasome activation plays an important role in the development of NASH and fibrogenesis. However, the mechanisms involved in NLRP3 activation in hepatic stellate cells (HSCs) have been unclear. The aim of this study was to investigate the mechanism of NLRP3 activation in HSCs and the role of NLPR3 inflammasome activation in HSCs on the development of nonalcoholic steatohepatitis (NASH) to fibrosis.
Primary HSCs isolated from SD rats were incubated with palmitic acid and/or LPS, respectively. For animal experiment, 4-week-old SD rats were fed with high fat diet (HF-diet) for 12 weeks, SD rats were sacrificed at 0, 4, 8 and 12 w. In another group of animal experiment, 4-week-old SD rats were fed with HF-diet and a NLRP3 inhibitor (intraperitoneal injection of NLRP3 inhibitor glybenclamide 5 mg/kg, injected every 3 days) for 12 weeks. Liver tissue and serum were harvested. RT-PCR, WB, ELISA, immunofluorescence and immunohistochemistry were performed to assess the NLRP3 inflammasome activation and signal molecules.
Palmitic acid stimulated NLPR3 inflammasome activation and fibrotic phenotype change in primary HSCs, LPS sensitizes the response of HSCs to palmitic acid. TLR4-NF-κB signal pathway was involved in NLRP3 inflammasome activation in palmitic acid-exposed HSCs and HF diet-induced NASH. It is evident that administration of NLRP3 inhibitor reduced the development of NASH to liver fibrosis in the NASH rat model.
Palmitic acid stimulates NLRP3 inflammasome activation through the TLR4-NF-κB signal pathway in HSCs. NLRP3 inflammasome activation in HSCs exacerbates the development of NASH to liver fibrosis.
NLRP3炎性小体激活在非酒精性脂肪性肝炎（NASH）的发展和纤维化过程中起重要作用。然而，肝星状细胞（HSCs）中NLRP3激活所涉及的机制尚不清楚。本研究旨在探讨HSCs中NLRP3激活的机制以及NLRP3炎性小体激活在HSCs对非酒精性脂肪性肝炎（NASH）向纤维化发展中的作用。
分别用棕榈酸和/或脂多糖孵育从SD大鼠分离的原代HSCs。在动物实验中，4周龄的SD大鼠喂食高脂饮食（HF饮食）12周，在0、4、8和12周时处死SD大鼠。在另一组动物实验中，4周龄的SD大鼠喂食HF饮食并给予NLRP3抑制剂（腹腔注射NLRP3抑制剂格列本脲5mg/kg，每3天注射一次）12周。收集肝脏组织和血清。进行逆转录-聚合酶链反应（RT-PCR）、蛋白质免疫印迹（WB）、酶联免疫吸附测定（ELISA）、免疫荧光和免疫组织化学以评估NLRP3炎性小体激活和信号分子。
棕榈酸刺激原代HSCs中NLRP3炎性小体激活和纤维化表型改变，脂多糖使HSCs对棕榈酸的反应敏感。Toll样受体4（TLR4）-核因子κB（NF-κB）信号通路参与棕榈酸暴露的HSCs和HF饮食诱导的NASH中NLRP3炎性小体激活。显然，在NASH大鼠模型中给予NLRP3抑制剂可减少NASH向肝纤维化的发展。
棕榈酸通过HSCs中的TLR4-NF-κB信号通路刺激NLRP3炎性小体激活。HSCs中NLRP3炎性小体激活加剧了NASH向肝纤维化的发展。
