| Background:NLRP3 inflammasome are intracellular multiprotein complexes which consist of the NOD-like receptor, the adaptor molecule ASC, and the effector molecule procaspase-1. The activation of NLRP3 inflammasome culminates in caspase-1 activation and secretion of IL-1β and IL-18 which involved in inflammatory and immune response. Previous studies showed that the activation of NLRP3 inflammasome was associated with liver injury. However, its role in the pathogenesis of liver failure is unclear.AIM:To investigate the characteristics of NLRP3 inflammasome in liver failure and study the relationship between the expression levels of NLRP3 mRNA and severity with prognosis by observing the expression levels of NLRP3 inflammasome and CD40-CD40L molecular in HBV-related acute-on-chronic liver failure (HBV-ACLF) patients and Ga1N/LPS induced acute liver failure mice model.In addition, we discuss the possible mechanism of regulation of NLRP3 inflammasome activation.Method:(1) 60 HBV-ACLF patients,20 chronic hepatitis B (CHB) patients and 20 health controls (HC) were enrolled. mRNA expression of all inflanmasome components and CD40-CD40L from PBMCs were measured by PCR. Serum IL-1β, IL-18, sCD40 and sCD40L levels were measured by ELISA. Meantime, we study the relationship between the expression levels of NLRP3 mRNA and severity with prognosis in HBV-ACLF patients. (2) We detected the expression levels of components of NLRP3 inflammasome and CD40-CD40L molecular from the serum and liver tissues of GalN/LPS induced acute liver failure mice model and control group by PCR, ELISA, western blot and IHC. Mean while, the activation of caspase-1 were detected by caspase-1 activity assay kit.Result:(1) The mRNA expression of NLRP3 (63.28±51.38×10-4)、ASC (395.23±141.15×10-4)、procaspase-1 (325.64±167.44×10-4)、proIL-1β (896.80±555.55×10-4)in HBV-ACLF patients were significantly higher than those in CHB patients and HC, with serum IL-1β (4.29±2.28 pg/ml)、IL-18 (1358.17±421.29 pg/ml) levels increased significantly((P<0.05). Interestingly, significant increases of CD40 mRNA (65.85±46.18×10-4) expression and lower expression of CD154 mRNA (17.17±11.18×10-4) were observed in HBV-ACLF patients; however, serum levels of sCD154 (201.89±14.07 pg/ml) in HBV-ACLF patients increased significantly, but serum levels of sCD40 (48.28±16.31 pg/ml) in HBV-ACLF patients were lower than those in CHB patients, (P<0.05); There was significant positive correlation between NLRP3 mRNA and CD40 mRNA (r=0.852, P=0.000), the expression of NLRP3 mRNA in non-survival HBV-ACLF patients was higher than those in survival patients(P<0.01), and the expression of NLRP3 mRNA were correlated with MELD scores (r=0.466, P=0.000), AUC of NLRP3 were 0.709(95% CI 0.575-0.843). (2) In the process of GalN/LPS induced acute liver failure in mice, we found that the mRNA expression of NLRP3 (5.71±1.38)、ASC (3.03±1.15)、procaspase-1 (19.75±7.44)、 proIL-1β(16.80±5.55)、proIL-18 (0.76±0.34)、NF-κB (2.98±2.44)、CD40 (35.85±6.18)、CD154 (2.16±0.72) were remarkably higher in liver tissues of 6h mice model than those of 3h mice model, with activation of caspase-1 and serum IL-1β、 IL-18 levels increased significantly. The protein of NLRP3 increased gradually with aggravating acute liver injury.Conclusion:The activation of NLRP3 inflammasome play an important role on immunopathogenesis of HBV-ACLF and GalN/LPS induced acute liver failure in mice. The expression level of NLRP3 mRNA was associated with disease severity, and the patients with higher NLRP3 mRNA may have a poor prognosis. The expression of CD40 mRNA showed a significant correlation with NLRP3 mRNA, but how to CD40-CD40L regulated NLRP3 inflammasome in liver failure still need further study. |
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