The Mechanism Of NLRP3Inflammasome In Kupffer Cells In Non-alcoholic Steatohepatitis

Objective (1) To confirm the expression of NLRP3in Kupffer cells（KCs） in NASH patients’ liver.(2) To discuss the function ofNLRP3inflammasome in the inflammation of KCs induced by freefatty acids (FFA).Methods (1) Collected the liver specimens of the patients whowere probably with NASH. Carried on HE, MASSON dyes, group thespecimens according to the score of NAS: NAS>4as NASH group（5cases）, NAS <3as control group（4cases）. Immunohistochemistrywere done to examine expressions of KCs, NLRP3and caspase-1.(2)Isolated KCs by perfusion in situ with collagenase plus gradientcentrifugation with Percoll liquids, identified and stimulated by FFA.Observed its shape change. Western blot examined NLRP3, Caspase-1,the ASC protein expression after stimulation. ELISA further examinedthe level of IL-1and IL-18secreted by KCs.Results (1) In the NASH, not only observed that steatosis werewidespread among liver cells, the inflammatory cells infiltrated, thecollagen fiber proliferated; but also found the KCs cell massive accumulated and the activated, simultaneously the NALP3and thecaspase-1expression in KCs were also obviously increased.(2) AfterKCs stimulated by FFA, the level of NLRP3（WB：0.565±0.027）、Caspase-1（WB：0.541±0.031） and ASC（WB：0.594±0.038）proteinexpression were obviously increased than control NLRP3（WB：0.148±0.018）、 Caspase-1（WB：0.122±0.007）、 ASC （WB：0.128±0.015）(p<0.001); the level of IL-1（578±36.21pg/ml） andIL-18（197±27.16pg/ml） expression also increased with it，comparewith the control IL-1（26.34±7.36pg/ml）、IL-18（22.17±6.28pg/ml）.(p<0.05).Conclusion (1) The activated NLRP3inflammasome in KCs areexist in NASH patients’ liver. The activation of KCs and NALP3inflammasome causes the inflammation factor the released anddamaged the cells. They may play a vital role in NASH development.(2) FFA has the obviously fat toxicity to KCs, the KCs inflammationrespond to NLRP3is possibly induced by FAA, subsequently, NLRP3,ACS, the Caspase-1protein expression as well as secretion of IL-1and IL-18are increased. Thus, inhibiting NLRP3may be a new way forthe treatment of inflammatory liver injury by FFA.