Rifaximin Prevents Intestinal Barrier Dysfunction and Alleviates Liver Injury in MCT-induced HSOS Mice.

OBJECTIVE: Rifaximin is an effective component of treatment strategies for liver and intestinal diseases. However, the efficacy of rifaximin in hepatic sinusoidal obstruction syndrome (HSOS) has not been explored. The present study aimed to investigate the efficacy and mechanism of rifaximin in HSOS. METHODS: An HSOS model was established in mice through the administration of monocrotaline (MCT, 800 mg/kg), and part of the HSOS mice were intragastrically administered with rifaximin. Then, the efficacy of rifaximin in HSOS was evaluated based on the liver pathological findings, liver proinflammatory cytokines, and alanine aminotransferase and aspartate aminotransferase levels. The Ussing chamber was used to evaluate the intestinal permeability, and tight junction (TJ) proteins were measured by Western blotting and real-time polymerase chain reaction to evaluate the intestinal barrier integrity. Then, the serum proinflammatory cytokine levels were evaluated by enzyme-linked immunosorbent assay. Afterwards, an in vitro experiment was performed to determine the relationship between rifaximin and TJ proteins. RESULTS: Rifaximin effectively alleviated the MCT-induced HSOS liver injury, suppressed the expression of liver proinflammatory cytokines, and reduced the serum levels of tumor necrosis factor-alpha and interleukin-6. Furthermore, rifaximin reduced the intestinal permeability, improved the intestinal barrier integrity, and promoted the expression of TJ proteins. CONCLUSION: The results revealed that the intestinal barrier integrity was destroyed in MCT-induced HSOS. The significant alleviation of MCT-induced HSOS induced by rifaximin might be correlated to the repairment of intestinal barrier integrity via the regulation of the TJ protein expression.

Contribution of gut microbiota to drug-induced liver injury.

Drug-induced liver injury (DILI) is caused by various drugs with complex pathogenesis, and diverse clinical and pathological phenotypes. Drugs damage the liver directly through drug hepatotoxicity, or indirectly through drug-mediated oxidative stress, immune injury and inflammatory insult, which eventually lead to hepatocyte necrosis. Recent studies have found that the composition, relative content and distribution of gut microbiota in patients and animal models of DILI have changed significantly. It has been confirmed that gut microbial dysbiosis brings about intestinal barrier destruction and microorganisms translocation, and the alteration of microbial metabolites may cause or aggravate DILI. In addition, antibiotics, probiotics, and fecal microbiota transplantation are all emerging as prospective therapeutic methods for DILI by regulating the gut microbiota. In this review, we discussed how the altered gut microbiota participates in DILI.

Attenuation by Time-Restricted Feeding of High-Fat and High-Fructose Diet-Induced NASH in Mice Is Related to Per2 and Ferroptosis.

Nonalcoholic steatohepatitis (NASH) is a chronic and progressive disease whose treatment strategies are limited. Although time-restricted feeding (TRF) is beneficial for metabolic diseases without influencing caloric intake, the underlying mechanisms of TRF action in NASH and its efficacy have not yet been demonstrated. We herein showed that TRF effectively alleviated NASH, producing a reduction in liver enzymes and improvements in liver pathology. Regarding the mechanisms by which TRF mitigates NASH, we ascertained that TRF inhibited ferroptosis and the expression of the circadian gene Per2. By adopting a hepatocyte-specific Per2-knockout (Per2△hep) mice model, we clarified the critical role of Per2 in exacerbating NASH. According to the results of our RNA-Seq analysis, the knockout of Per2 ameliorated NASH by inhibiting the onset of ferroptosis; this was manifested by diminished lipid peroxidation levels, decreased mRNA and protein levels for ferroptosis-related genes, and alleviated morphologic changes in mitochondria. Furthermore, using a ferroptosis inhibitor, we showed that ferroptosis significantly aggravated NASH and noted that this was likely achieved by regulation of the expression of peroxisome proliferator activated receptor (PPAR)α. Finally, we discerned that TRF and hepatocyte-specific knockout of Per2 promoted the expression of PPARα. Our results revealed a potential for TRF to effectively alleviate high-fat and high-fructose diet-induced NASH via the inhibition of Per2 and depicted the participation of Per2 in the progression of NASH by promoting ferroptosis, which was ultimately related to the expression of PPARα.

Liver damage at admission is an independent prognostic factor for COVID-19.

OBJECTIVE: Abnormal liver function is a common form of extra-pulmonary organ damage in patients with coronavirus disease 2019 (COVID-19). Patients with severe COVID-19 have a higher probability and progression of liver injury than those without severe disease. We aimed to evaluate the prognosis of liver injury in patients with COVID-19. METHODS: We retrospectively included 502 patients with laboratory-confirmed SARS-CoV-2 infection. Clinical features and survival of patients with and without liver injury were compared. Cox proportional hazards models were used to determine the variables that might have an effect on survival. RESULTS: Among the 502 patients enrolled, 301 patients had abnormal liver function with increased neutrophil count, C-reactive protein, creatinine, troponin I (TnI), D-dimer, lactose dehydrogenase and creatine kinase. Patients with abnormal liver functions had a higher mortality rate (28.9% vs 9.0%, P < 0.001), a higher ratio of male sex (65.1% vs 40.8%, P < 0.001) and a higher chance of developing systemic inflammatory response syndrome (53.5% vs 41.3%, P = 0.007). Among patients with abnormal liver functions, patients with grade 2 liver damage (with both abnormal alanine aminotransferase or aspartate aminotransferase levels and abnormal alkaline phosphatase or gamma-glutamyl transpeptidase levels) had a higher ratio of male patients, elevated neutrophil count, procalcitonin, D-dimer levels and mortality rate. Multivariate Cox regression analyses suggested that the grade of liver damage (hazard ratio: 1.377, 95% confidence interval: 1.000-1.896, P = 0.049) was an independent predictor of death. CONCLUSIONS: Patients with COVID-19 and abnormal liver functions have a higher mortality than those with normal liver functions. Liver damage is an independent prognostic factor of COVID-19.