NLRP3 inflammasome inhibitor MCC950 ameliorates sepsis-associated organ damage via suppressing Th1/Th17 response and promoting Tregs response in mice
YE Yumei1, CHEN Longwang2, ZHANG Wanli3,WANG Xuetao4.
1.Department of Ultrasound Imaging, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325015, China; 2.Department of Emergency, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325015, China; 3.Department of Emergency, Wenzhou Longwan District First People’s Hospital, Wenzhou 325024, China; 4.Department of Intensive Care Unit, Wenzhou Longwan District First People’s Hospital, Wenzhou 325024, China
YE Yumei,CHEN Longwang,ZHANG Wanli, et al. NLRP3 inflammasome inhibitor MCC950 ameliorates sepsis-associated organ damage via suppressing Th1/Th17 response and promoting Tregs response in mice[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2024, 54(3): 190-198.
Abstract：Objective: To investigate the effects of MCC950, the NLRP3 inflammasome inhibitor, on T cell differentiation and organ damage in septic mice. Methods: Eighteen C57BL/6 male mice were randomly divided into sham group, CLP group and MCC950 group, with six in each. In CLP group and MCC950 group, the sepsis model was operated by cecal ligation and puncture (CLP). MCC950 group was injected intraperitoneally with MCC950 (50 mg/kg) dissolved in 0.5 mL saline, and the sham group and CLP group were injected withan equal volume of saline. Mouse serum and issue were collected at 24 h after surgery. HE staining was used to observe the histopathological damage in lungs and kidneys. The survival rate was calculated in 7 d after operation; The level of splenic NLRP3 protein was detected by Western blot; IL-1β, IL-18, IL-1α, IL-6, and TNF-α protein level in the serum and lung was measured by ELISA; The proportion of helper T cells (Th)1, Th17, and regulatory T cells (Tregs) in splenic lymphocytes were detected by flow cytometry. Results: Compared with the sham group, the septic mice had inflammatory cell infiltration, oedema and alveolar wall thickening in lungs (P<0.05), and reduction of renal tubular brush border and epithelial cells, glomerular atrophy, diffusely dilatation of the renal tubules with many inflammatory cell infiltration (P<0.05). The expression of NLRP3 in the spleen and the
levels of IL-1β, IL-18, IL-1α, IL-6, and TNF-α in the serum and lung in CLP group were higher than that in sham group (P<0.05). Furthermore, compared with sham group, the proportions of CD4+IFN-γ+ Th1 and CD4+IL-17+ Th17 in the spleen were elevated, accompanied by a slight increase in the proportion of CD4+CD25+Foxp3+ Tregs (P<0.05). The 7 d survival rate of septic mice was 30%. Meanwhile, the inflammatory cell infiltration and oedema in the lung in septic mice were attenuated by MCC950 treatment (P<0.05). The glomerular telangiectasia was not obvious, and the dilatation of the renal tubules was decreased in the MCC950 group (P<0.05). Compared with CLP group, the expression of NLRP3 in the spleen in CLP group was down-regulated, and the levels of IL- 1β, IL-18, IL-1α, IL-6, and TNF-α in the serum and lung were reduced (P<0.05). In addition, the proportion of CD4+IFN-γ+ Th1 and CD4+IL-17+ Th17 was decreased, and the proportion of CD4+CD25+Foxp3+ Tregs was more significantly increased than that in CLP group (P<0.05). The 7 d survival rate of septic mice was improved (P<0.05). Conclusion: Inhibition of NLRP3 activation by MCC950 ameliorated organ damage in septic mice, and its effect may depend on inhibiting Th1/Th17 response and promoting Tregs response.
