High fiber dietary and sodium butyrate attenuate experimental autoimmune hepatitis through regulation of immune regulatory cells and intestinal barrier.

Autoimmune hepatitis (AIH) is chronic autoimmune liver disease accompanied with the imbalance of Treg/Th17 and increased intestinal permeability. We investigated the effects of a high fiber diet and sodium butyrate on the Treg/Th17 and intestinal barrier function in an experimental autoimmune hepatitis. Intraperitoneal injection of hepatic antigen (S100) was used to induce experimental autoimmune hepatitis mice model and mice were divided into normal control, S100 model control, S100 plus high fiber diet and S100 plus sodium butyrate. Serum aminotransferases and liver histology were examined. Short chain fatty acids in feces were determined by HPLC. The ratio of CD4 + C25 + Foxp3+ Treg and CD4 + IL-17 + Th17 were evaluated by flow cytometry. Tight junction proteins Zonula ocluden, Occludin and Claudin-1 were used to assess intestinal barrier function, so does Escherichia coli protein in the liver. Mice fed with either high fiber diet or sodium butyrate showed significantly lower levers of serum aminotransferases and minor liver injury compared to that of model control. Moreover, the ratio of Treg/Th17 was significantly higher in high fiber diet and sodium butyrate fed mice than that in model control. Furthermore, high fiber diet and sodium butyrate significantly increased intestinal tight junction proteins and decreased Escherichia Coli protein in the liver. In conclusion, high fiber diet and sodium butyrate can attenuate development of autoimmune hepatitis through regulation of immune regulatory cells and intestinal barrier function.

Attenuation of Experimental Autoimmune Hepatitis in Mice with Bone Mesenchymal Stem Cell-Derived Exosomes Carrying MicroRNA-223-3p.

MicroRNA-223-3p (miR-223-3p) is one of the potential microRNAs that have been shown to alleviate inflammatory responses in pre-clinical investigations and is highly encased in exosomes derived from bone mesenchymal stem cells (MSC-exosomes). MSC-exosomes are able to function as carriers to deliver microRNAs into cells. Autoimmune hepatitis is one of the challenging liver diseases with no effective treatment other than steroid hormones. Here, we examined whether MSC-exosomes can transfer miR-223-3p to treat autoimmune hepatitis in an experimental model. We found that MSC-exosomes were successfully incorporated with miR-223-3p and delivered miR-223-3p into macrophages. Moreover, there was no toxic effect of exosomes on the macrophages. Furthermore, treatments of either exosomes or exosomes with miR-223-3p successfully attenuated inflammatory responses in the liver of autoimmune hepatitis and inflammatory cytokine release in both the liver and macrophages. The mechanism may be related to the regulation of miR-223-3p level and STAT3 expression in the liver and macrophages. These results suggest that MSC-exosomes can be used to deliver miR-223-3p for the treatment of autoimmune hepatitis.

BMSCs-derived miR-223-containing exosomes contribute to liver protection in experimental autoimmune hepatitis.

Autoimmune hepatitis is a chronic inflammatory disease in the liver with potential to the development of liver fibrosis. Recent evidences suggest that bone marrow derived mesenchymal stem cells (BMSCs) may exert its therapeutic activity through exosomes. Moreover, miR-223 is highly expressed in BMSCs and plays an important role in autoimmune diseases. Therefore, in this study, hepatoprotective role of BMSCs and miR-223 was investigated in both mice and hepatocytes. Liver antigen S100 was used to establish autoimmune hepatitis model in mice while LPS and ATP were used to establish cell injury model in hepatocyte. Before the experiments, BMSCs were infected with pre-miR-223 and transfected with miR-223 inhibitor respectively. Exosomes from bone marrow stem cells were isolated by ultracentrifugation. Liver injury was evaluated by serum levels of ALT and AST as well as liver histology. Inflammation and cell death were examined by inflammatory cytokines and lactase dehydrogenase respectively. Both BMSCs-exo and BMSCs-exomiR-223(+) significantly reversed either S100 or LPS/ATP induced injury in mice and hepatocytes. Meanwhile, the expressions of cytokines, NLRP3 and caspase-1 were also downregulated by BMSCs-exo and BMSCs-exomiR-223(+) at both protein and mRNA levels in mice and hepatocytes. Moreover, BMSCs-exomiR-223(-) reverses the effects of BMSCs-exo and BMSCs-exomiR-223(+) in mouse AIH and in hepatocytes. In conclusion, bone marrow stem cell derived exosomes can protect liver injury in an experimental model of autoimmune hepatitis and the mechanism could be related to exosomal miR-223 regulation of NLRP3 and caspase-1.

Sodium butyrate ameliorates S100/FCA-induced autoimmune hepatitis through regulation of intestinal tight junction and toll-like receptor 4 signaling pathway.

BACKGROUND AND AIM: Recent investigation revealed that dysbiosis in the gut flora and disruption of permeability of intestinal barrier are possible causes for the development of autoimmune hepatitis. Supplementation of sodium butyrate has been suggested to protect liver injury from disrupted permeability of small intestine. In current study, we employed S100/Freund's complete adjuvant induced autoimmune hepatitis to investigate therapeutic efficacy of sodium butyrate and its mechanism in the liver and upper small intestine. METHODS: C57BL/6 mice were employed and divided into three groups - control group (n=8), autoimmune hepatitis group (n=12) and autoimmune hepatitis with treatment of sodium butyrate group (n=12). Histological staining and western blot analyses were employed to evaluate liver and upper small intestine morphology and gene expression respectively. RESULTS: The findings revealed that S100/Freund's complete adjuvant caused liver injury and disruption of upper small intestine villi. Sodium butyrate attenuated the injuries and prevented migration of Escherichia coli into the liver. Moreover, the effect of sodium butyrate on protection of injuries of the liver and upper small intestine could be due to inhibition of toll-like receptor 4 signaling pathway, as well as its down-regulation of inflammatory cytokines - interleukin-6 and tumor necrosis factor-a. CONCLUSIONS: Sodium butyrate can prevent liver injury by maintaining the integrity of small intestine and inhibiting inflammatory response in S100/Freund's complete adjuvant induced autoimmune hepatitis.

Effect of transforming growth factor beta and bone morphogenetic proteins on rat hepatic stellate cell proliferation and trans-differentiation.

AIM: To explore different roles of TGF-beta (transforming growth factor beta) and bone morphogenetic proteins (BMPs) in hepatic stellate cell proliferation and trans-differentiation. METHODS: Hepatic stellate cells were isolated from male Sprague-Dawley rats. Sub-cultured hepatic stellate cells were employed for cell proliferation assay with WST-1 reagent and Western blot analysis with antibody against smooth muscle alpha actin (SMA). RESULTS: The results indicated that TGF-beta1 significantly inhibited cell proliferation at concentration as low as 0.1 ng/ml, but both BMP-2 and BMP-4 did not affect cell proliferation at concentration as high as 10 ng/ml. The effect on hepatic stellate cell trans-differentiation was similar between TGF-beta1 and BMPs. However, BMPs was more potent at trans-differentiation of hepatic stellate cells than TGF-beta1. In addition, we observed that TGF-beta1 transient reduced the abundance of SMA in hepatic stellate cells. CONCLUSION: TGF-beta may be more important in regulation of hepatic stellate cell proliferation while BMPs may be the major cytokines regulating hepatic stellate cell trans-differentiation.

Serum hepatic enzyme manifestations in patients with severe acute respiratory syndrome: retrospective analysis.

AIM: To evaluate the hepatic function in patients with severe acute respiratory syndrome (SARS) and possible causes of hepatic disorder in these patients. METHODS: One hundred and eighty-two patients with SARS were employed in a retrospective study that investigated hepatic dysfunction. Liver alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactic dehydrogenase (LDH) were analyzed in these patients. Patients with different hospital treatments were further investigated. RESULTS: Of the 182 patients, 128(70.3%) had abnormal ALT activity, 57(31.3%) had abnormal AST activity and 87(47.8%) had abnormal LDH activity. The peak of elevated hepatic enzyme activities occurred between the sixth day and the tenth day after the first day of reported fever. Of the 182 patients, 160(87.9%) had been treated with antibiotics, 137(75.2%) with Ribavirin, and 115(63.2%) with methylpredisolone. There was no statistically significant correlation between the duration of Ribavirin treatment and hepatic dysfunction. CONCLUSION: Abnormal liver functions were common in patients with SARS and could be associated with virus replication in the liver.

CD4+ CD25+ regulatory T cells: a therapeutic target for liver diseases.

BACKGROUND: Regulatory T cells (Tregs) have been shown to play an important role in maintaining peripheral immune homeostasis by suppressing autoreactive and allergen-specific T cells and turning off the immune response after the pathogen has been cleared. However, in certain situations Tregs can impair effective immunity to some pathogens and tumour cells. OBJECTIVE: To review the role of Tregs in liver pathology and to assess the potential to enhance or inhibit their function as applied to the treatment of liver disease. METHODS: The literature was reviewed using standard indexing terms and incorporating publications up to and including those published in 2007. RESULTS/CONCLUSIONS: Tregs are therapeutic targets for modulation in autoimmune disease and may provide new opportunities for application to human liver conditions.