ABSTRACT
Immune-related GTPase M (IRGM) induces autophagy and suppresses inflammation, but its putative role and signaling mechanism remain undefined in the pathogenesis of liver failure. This study aimed to address how IRGM attenuates inflammatory injury by regulating autophagy in liver failure. In this study, a total of 10 patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) and 10 healthy controls were prospectively enrolled. Intrahepatic expression of IRGM/Irgm1, NLRP3 inflammasome (NLRP3, ASC, and caspase-1), autophagy-related proteins (LC3II, P62), and inflammatory cytokines (IL-1ß, TNF-α) were measured. Autophagy was activated by rapamycin (4 mg/kg) in an acute liver failure (ALF) mouse model, which was used to further study the expression of Irgm1, NLRP3 inflammasome, autophagy-related proteins, and inflammatory cytokines using both qRT-PCR and Western blot analyses. Irgm1 expression was knocked down using Irgm1 short hairpin RNA (shRNA) in lipopolysaccharide (LPS)-induced AML12 cells to investigate the effects of Irgm1 deletion on autophagy and inflammation. We found that the expression of IRGM and autophagy-related proteins was significantly downregulated while the NLRP3 inflammasome was significantly upregulated in the livers of HBV-ACLF patients and the ALF mouse model (all P < 0.05). Rapamycin-induced autophagy ameliorated intrahepatic NLRP3 inflammasome activation and decreased inflammation and necrosis in the ALF mice. Irgm1 knockdown decreased autophagy and significantly upregulated NLRP3 inflammasome activation in AML12 cells (all P < 0.05). Rapamycin-induced autophagy also protected against hepatocyte injury following LPS stimulation in vitro by inhibiting NLRP3 inflammasome activation. Thus, IRGM/Irgm1 alleviates inflammation-mediated hepatocyte injury by regulating autophagy. This study provides new insight into potential molecular targets to treat liver failure.
ABSTRACT
BACKGROUND AND AIM: Patients with end-stage liver disease (ESLD) are susceptible to invasive pulmonary aspergillosis (IPA). This study aimed to investigate the risk factors affecting the occurrence and short-term prognosis of ESLD complicated by IPA. METHODS: This retrospective case-control study included 110 patients with ESLD. Of them, 27 ESLD-IPA received antifungal therapy with amphotericin B (AmB); 27 AmB-free-treated ESLD-IPA patients were enrolled through 1:1 propensity score matching. Fifty-six ESLD patients with other comorbid pulmonary infections were enrolled as controls. The basic features of groups were compared, while the possible risk factors affecting the occurrence and short-term outcomes of IPA were analyzed. RESULTS: Data analysis revealed invasive procedures, glucocorticoid exposure, and broad-spectrum antibiotic use were independent risk factors for IPA. The 54 patients with ESLD-IPA exhibited an overall treatment effectiveness and 28-d mortality rate of 50.00% and 20.37%, respectively, in whom patients treated with AmB-containing showed higher treatment efficacy than patients treated with AmB-free antifungal regimens (66.7% vs. 33.3%, respectively, χ2 = 6.000, P = 0.014). Multivariate logistic regression analysis revealed that the treatment regimen was the only predictor affecting patient outcomes, with AmB-containing regimens were 4.893 times more effective than AmB-free regimens (95% CI, 1.367-17.515; P = 0.015). The only independent predictors affecting the 28-d mortality rate were neutrophil-to-lymphocyte ratio and IPA diagnosis (OR = 1.140 and 10.037, P = 0.046 and 0.025, respectively). CONCLUSIONS: Glucocorticoid exposure, invasive procedures, and broad-spectrum antibiotic exposure increased the risk of IPA in ESLD patients. AmB alone or combined with other antifungals may serve as an economical, safe, and effective treatment option for ESLD-IPA.
