Chronic hepatic inflammation from multiple etiologies leads to a fibrogenic response that can progress to cirrhosis and liver failure. Transplantation of human amniotic epithelial cells (hAEC) from term delivered placenta has been shown to decrease mild to moderate hepatic fibrosis in a murine model. To model advanced human liver disease and assess the efficacy of hAEC therapy, we transplanted hAEC in mice with advanced hepatic fibrosis. Immunocompetent C57BL/6 mice were administered carbon tetrachloride (CCl₄) twice weekly resulting in bridging fibrosis by 12 weeks. hAEC (2×10⁶) were infused via the tail vein at week 8 or weeks 8 and 10 (single and double dose, respectively). Human cells were detected in mouse liver four weeks after transplantation showing hAEC engraftment. CCl₄ treated mice receiving single or double hAEC doses showed a significant but similar decrease in liver fibrosis area associated with decreased activation of collagen-producing hepatic stellate cells and decreased hepatic protein levels of the pro-fibrogenic cytokine, transforming growth factor-beta1. CCl₄ administration caused hepatic T cell infiltration that decreased significantly following hAEC transplantation. Hepatic macrophages play a crucial role in both fibrogenesis and fibrosis resolution. Mice exposed to CCl₄ demonstrated increased numbers of hepatic macrophages compared to normal mice; the number of macrophages decreased significantly in CCl₄ treated mice given hAEC. These mice had significantly lower hepatic protein levels of the chemokine monocyte chemoattractant protein-1 than mice given CCl₄ alone. Alternatively activated M2 macrophages are associated with fibrosis resolution. CCl₄ treated mice given hAEC showed increased expression of genes associated with M2 macrophages including YM-1, IL-10 and CD206. We provide novel data showing that hAEC transplantation induces a wound healing M2 macrophage phenotype associated with reduction of established hepatic fibrosis that justifies further investigation of this potential cell-based therapy for advanced hepatic fibrosis.

Background: Hepatic stellate cells (HSCs) are the primary collagen-secreting cells in the liver. While HSCs are the major cell type involved in the pathogenesis of liver fibrosis, hepatic macrophages also play an important role in mediating fibrogenesis and fibrosis resolution. Previously, we observed a reduction in HSC activation, proliferation and collagen synthesis following exposure to human amnion epithelial cells (hAEC) and hAEC-conditioned media (hAEC-CM). This suggested that specific factors secreted by hAECs might be effective in ameliorating liver fibrosis. hAEC-derived extracellular vesicles (hAEC-EVs), which are nanosized (40-100nm) membrane bound vesicles, may act as novel cell-cell communicators. Accordingly, we evaluated the efficacy of hAEC-EV in modulating liver fibrosis in a mouse model of chronic liver fibrosis and in human HSC. Methods: hAEC-EVs were isolated and characterised. C57BL/6 mice with CCl4 induced liver fibrosis were administered hAEC-EV, hAEC-CM or hAEC-EV depleted medium (hAEC EVDM). LX-2 cells, a human HSC line, and bone marrow derived mouse macrophages were exposed to hAEC-EV, hAEC-CM and hAEC-EVDM. Mass spectrometry was used to examine the proteome profile of each preparation. Results: The extent of liver fibrosis and number of activated HSCs were reduced significantly in CCl4 treated mice given hAEC-EVs, hAEC-CM and hAEC EVDM compared to untreated controls. Hepatic macrophages were significantly decreased in all treatment groups, where a predominant M2 phenotype was observed. Human HSCs cultured with hAEC-EV and hAEC-CM displayed a significant reduction in collagen synthesis and hAEC-EV, hAEC-CM and hAEC EVDM altered macrophage polarization in bone marrow-derived mouse macrophages. Proteome analysis showed that 163 and 164 proteins were unique to hAEC-CM and hAEC-EVDM, respectively, and 67 proteins were co-identified components with the hAEC-EV fraction. Conclusion: This study provides novel data showing that hAEC-derived EVs significantly reduced liver fibrosis and macrophage infiltration to an extent similar to hAEC-EVDM and hAEC-CM. hAEC-EV based therapy may be a potential therapeutic option for liver fibrosis.

Protease-activated receptor (PAR) 2 is a G-protein–coupled receptor that is activated after proteolytic cleavage by serine proteases, including mast cell tryptase and activated coagulation factors. PAR-2 activation augments inflammatory and profibrotic pathways through the induction of genes encoding proinflammatory cytokines and extracellular matrix proteins. Thus, PAR-2 represents an important interface linking coagulation and inflammation. PAR-2 is widely expressed in cells of the gastrointestinal tract, including hepatic stellate cells (HSCs), endothelial cells, and hepatic macrophages; however, its role in liver fibrosis has not been previously examined. We studied the development of CCl4-induced liver fibrosis in PAR-2 knockout mice, and showed that PAR-2 deficiency reduced the progression of liver fibrosis, hepatic collagen gene expression, and hydroxyproline content. Reduced fibrosis was associated with decreased transforming growth factor beta (TGFβ) gene and protein expression and decreased matrix metalloproteinase 2 and tissue inhibitor of matrix metalloproteinase 1 gene expression. In addition, PAR-2 stimulated activation, proliferation, collagen production, and TGFβ protein production by human stellate cells, indicating that hepatic PAR-2 activation increases profibrogenic cytokines and collagen production both in vivo and in vitro . Conclusion : Our findings demonstrate the capacity of PAR-2 activation to augment TGFβ production and promote hepatic fibrosis in mice and to induce a profibrogenic phenotype in human HSCs. PAR-2 antagonists have recently been developed and may represent a novel therapeutic approach in preventing fibrosis in patients with chronic liver disease.

Background: Non-alcoholic fatty liver disease (NAFLD) is associated with visceral adiposity. We assessed the effectiveness of time-restricted fasting (TRF) for 16 h daily without calorie restrictions compared to standard care (SC; diet and lifestyle advice) in improving visceral adiposity and steatosis via controlled attenuation parameter (CAP). Methods: In a prospective single-blind randomized controlled trial, 32 participants with NAFLD were randomly assigned to TRF or SC for 12 weeks. The secondary endpoints were changes in liver stiffness, anthropometry, blood pressure, and other metabolic factors. Results: Twenty-eight participants completed the first arm of the study (TRF = 14, SC = 14), with 23 completing the crossover arm (TRF = 10, SC = 13). The baseline demographics were similar between the groups. Intermittent fasting caused a significant decrease in hepatic steatosis (p = 0.038), weight (p = 0.005), waist circumference (p = 0.001), and BMI (p = 0.005) compared to standard care. Intermittent fasting also resulted in additional within-group changes that were not seen in the standard care intervention. Conclusion: TRF offers superior improvements in patients with NAFLD, improving steatosis, weight, and waist circumference despite a lack of change in overall caloric intake. Time-restricted fasting should be considered as a primary weight loss intervention in the context of NAFLD. Trial registration: ACTRN12613000935730.

Anemia may increase the likelihood of achieving a sustained virological response (SVR) during pegylated interferon and ribavirin treatment of hepatitis C virus (HCV) infection. To determine whether hemoglobin decline is associated with SVR, we retrospectively evaluated the CHARIOT study of 871 treatment-naïve HCV genotype 1 patients. Anemia (serum hemoglobin <100 g/L) occurred in 137 (16%) patients, of whom only 14 (10%) received erythropoietin. Hemoglobin decline >30g/L from baseline occurred in 76% of patients overall, including 526 patients who did not become anemic. Virological responses were higher in anemic patients compared with those who did not develop anemia (end of treatment, 80% versus 65%, P = 0.003; SVR, 61% versus 50%, P = 0.02); these differences remained significant when patients receiving erythropoietin were excluded from analysis. SVR was also higher in patients with hemoglobin decline >30 g/L compared with patients without a similar decline. In multiple logistic regression analyses with treatment group and baseline characteristics, the odds ratio for SVR was 1.97 (95% confidence interval, 1.08-3.62) for anemia and 2.17 (95% confidence interval, 1.31-3.62) for hemoglobin decline >30 g/L. Patients who first developed a hemoglobin decline >30 g/L during weeks 5-12 and 13-48 were more likely to achieve SVR than those who first developed such changes in weeks 0-4 or who never experienced them. Conclusion: Patients with HCV genotype 1 infection who develop anemia or experience a hemoglobin decline >30 g/L during weeks 5-48 of therapy achieve higher virological responses to pegylated interferon and ribavirin therapy that are unrelated to erythropoietin use. (HEPATOLOGY 2011;)