Kosuke Takeda

Reduction of endotoxin attenuates liver fibrosis through suppression of hepatic stellate cell activation and remission of intestinal permeability in a rat non-alcoholic steatohepatitis model

Previous clinical studies have demonstrated that endotoxin/toll-like receptor 4 (TLR4) signaling is critical in the inflammatory pathways associated with non-alcoholic steatohepatitis (NASH). In human and animal studies, NASH was associated with portal lipopolysaccharide (LPS) and the plasma LPS level was hypothesized to be associated with small intestinal bacterial overgrowth, change in composition of the microbiota and increased intestinal permeability. The aim of the present study was to investigate the roles of endogenous endotoxin and TLR4 in the pathogenesis of NASH. The effects of antibiotics were assessed in vivo using a choline deficiency amino acid (CDAA)-induced experimental liver fibrosis model. Antibiotics, including polymyxins and neomycins, were orally administered in drinking water. Antibiotics attenuated hepatic stellate cell (HSC) activation and liver fibrosis via TGF-β and collagen in an experimental hepatic fibrosis model. The mechanism by which antibiotics attenuated LPS-TLR4 signaling and liver fibrosis was assessed. Notably, TLR4 mRNA level in the liver was elevated in the CDAA group and the CDAA-induced increase was significantly reduced by antibiotics. However, no significant differences were observed in the intestine among all groups. Elevated mRNA levels of LPS binding protein, which was correlated with serum endotoxin levels, were recognized in the CDAA group and the CDAA-induced increase was significantly reduced by antibiotics. The intestinal permeability of the CDAA group was increased compared with the choline-supplemented amino acid group. The tight junction protein (TJP) in the intestine, determined by immunohistochemical analysis was inversely associated with intestinal permeability. Antibiotics improved the intestinal permeability and enhanced TJP expression. Inhibition of LPS-TLR4 signaling with antibiotics attenuated liver fibrosis development associated with NASH via the inhibition of HSC activation. These results indicated that reduction of LPS and restoration of intestinal TJP may be a novel therapeutic strategy for treatment of liver fibrosis development in NASH.

Predictive parameter of tolvaptan effectiveness in cirrhotic ascites

The efficacy of the vasopressin V2 receptor antagonist tolvaptan for difficult‐to‐treat cirrhotic ascites has recently been reported. However, its effect is variable among patients. This study aimed to clarify the predictive factors for obtaining a good response to tolvaptan in patients with difficult‐to‐treat ascites.

Combination treatment of dipeptidyl peptidase IV inhibitor (sitagliptin) and angiotensin-II type 1 receptor blocker (losartan) suppresses progression in a nondiabetic rat model of steatohepatitis

Dipeptidyl peptidase‐4 (DPP4) inhibitors (DPP4‐I) are oral glucose‐lowering drugs for type 2 diabetes mellitus. Previously, we reported that DPP4‐I (sitagliptin) exerted suppressive effects on experimental liver fibrosis in rats. Blockade of the renin–angiotensin system by angiotensin‐II type 1 receptor blocker (losartan), commonly used in the management of hypertension, has been shown to significantly alleviate hepatic fibrogenesis and carcinogenesis. We aimed to elucidate the effects and possible mechanisms of a sitagliptin + losartan combination on the progression of non‐diabetic non‐alcoholic steatohepatitis (NASH) in a rat model.

Serum angiotensin-converting enzyme level for evaluating significant fibrosis in chronic hepatitis B

AIM To evaluate the diagnostic performance of angiotensin-converting enzyme (ACE) on significant liver fibrosis in patients with chronic hepatitis B (CHB). METHODS In total, 100 patients with CHB who underwent liver biopsy in our hospital were enrolled, and 70 patients except for 30 patients with hypertension, fatty liver or habitual alcoholic consumption were analyzed. We compared histological liver fibrosis and serum ACE levels and evaluated the predictive potential to diagnose significant liver fibrosis by comparison with several biochemical marker-based indexes such as the aspartate aminotransferase (AST)-to-platelet ratio index (APRI), the fibrosis index based on four factors (FIB-4), the Mac-2 binding protein glycosylation isomer (M2BPGi) level and the number of platelets (Plt). RESULTS Serum ACE levels showed moderately positive correlation with liver fibrotic stages (R2 = 0.181). Patients with significant, advanced fibrosis and cirrhosis (F2-4) had significantly higher serum ACE levels than those with early-stage fibrosis and cirrhosis (F0-1). For significant fibrosis (≥ F2), the 12.8 U/L cut-off value of ACE showed 91.7% sensitivity and 75.0% specificity. The receiver-operating characteristic (ROC) curves analysis revealed that the area under the curve (AUC) value of ACE was 0.871, which was higher than that of APRI, FIB-4, M2BPGi and Plt. CONCLUSION The serum ACE level could be a novel noninvasive, easy, accurate, and inexpensive marker of significant fibrosis stage in patients with CHB.

Periostin cross‑reacts with the renin‑angiotensin system during liver fibrosis development

Periostin is a 90-kDa extracellular matrix protein, which is secreted primarily from fibroblasts and is expressed in the lungs, kidneys and heart valves. Angiotensin II (AT-II) serves pivotal roles in the pathogenesis of several diseases with accompanying fibrosis, including chronic liver diseases. AT-II induces periostin expression by regulating transforming growth factor-β1 (TGF-β1)/Smad signaling during cardiac fibrosis. The aim of the present study was to investigate the interaction between AT-II and periostin during liver fibrosis development. Fischer 344 rats were fed a choline-deficient L-amino-acid (CDAA)-defined diet for 12 weeks to simulate the development of steatohepatitis with liver fibrosis. Losartan, an AT-II type I receptor blocker, was administered to inhibit the effect of AT-II. The therapeutic effect of losartan on hepatic fibrosis development and on periostin expression was then evaluated. Several in vitro experiments were performed to examine the mechanisms underlying the interaction between AT-II and periostin in activated hepatic stellate cells (Ac-HSCs). Treatment with losartan suppressed the development of liver fibrosis induced by the CDAA diet, and reduced hepatic periostin expression. In addition, losartan treatment suppressed hepatic Ac-HSC expansion and hepatic TGF-β1 expression. In vitro analysis using LX2 HSC cells indicated that AT-II can augment TGF-β1 and collagen type I α1 mRNA expression via periostin expression, suggesting that the interaction between AT-II and periostin may serve a role in liver fibrosis development. In conclusion, blockade of AT-II-induced periostin may suppress the progression of liver fibrosis development.

Clinical significance of the Scheuer histological staging system for primary biliary cholangitis in Japanese patients.

Background Inadequate response to ursodeoxycholic acid (UDCA) is associated with unfavorable outcomes in patients with primary biliary cholangitis (PBC). We aimed to identify surrogate markers for predicting long-term prognosis and biochemical response to UDCA in patients with PBC. Patients and methods In this single-center, retrospective study, 99 patients with PBC were classified into responders (n=53) and nonresponders (n=46) based on reductions in the &ggr;-glutamyl transpeptidase levels at 1 year after initiating UDCA therapy (Nara criteria). We assessed whether the criteria for patentability by different countries are useful in predicting the prognosis of PBC. The accuracy of Scheuer and Nakanuma staging systems in predicting prognosis and treatment response was compared. Results Nara definition had comparable utility to the Paris-II definition for selecting patients in whom UDCA monotherapy can be safely continued. Patients at Scheuer stage 1 had a significantly better prognosis than those at Scheuer stages 3 or 4 (P<0.05 and 0.0001, respectively). Patients at Nakanuma stage 4 had decreased survival compared with those at stage 1 (P<0.05). The proportion of responders to nonresponders was significantly higher in stages 1–3 PBC than in stage 4 PBC, according to both staging systems (P<0.05 for both). All patients with Scheuer stage 4 PBC were nonresponders, whereas only 28.6% (2/7) of those with Nakanuma stage 4 PBC were responders. Conclusion The Scheuer staging system had greater utility in predicting long-term prognosis and UDCA response than the Nakanuma staging system.

Predisposing factors for hepatocellular carcinoma recurrence following initial remission after transcatheter arterial chemoembolization

Hepatocellular carcinoma (HCC) is prone to recurrence following curative treatment. The purpose of the present study was to identify the predisposing factors of HCC recurrence following complete remission achieved by transarterial chemoembolization (TACE). A retrospective cohort study of 70 consecutive patients with HCC who underwent TACE as the initial treatment was conducted. The patients were divided into two groups according to their 1-year disease-free survival (DFS) status; the early recurrence group (ER group; n=32), with HCC recurring within 1 year of initial TACE; and the non-early recurrence group (NER group; n=38), who did not experience recurrence within 1 year. The parameters identified as significantly associated with DFS time on univariate analysis were aspartate aminotransferase (AST), alanine aminotransferase and α-fetoprotein levels, as well as the tumor number (P=0.003, P=0.027, P=0.002 and P=0.005, respectively). Multivariate analysis revealed that AST levels and tumor number were significantly associated with a shorter DFS period (P=0.009 and P=0.038, respectively). The Mantel-Haenszel test revealed a significant trend of decreasing DFS with increasing tumor number. Among the patients with HCC in the ER group, locoregional recurrence occurred more frequently in those who received TACE alone compared with those treated with TACE combined with radiofrequency ablation treatment. In summary, multinodularity of HCC is the most potent predictive factor for the recurrence of HCC within 1 year of initial TACE.

Liver fibrosis progression predicts survival in patients with primary biliary cirrhosis.

The prognosis and natural history of primary biliary cirrhosis (PBC) has improved, and the clinical end‐point for PBC needs to be discovered. We aimed to identify surrogate markers for predicting long‐term prognosis in patients with PBC.

Severe Aplastic Anemia following Parvovirus B19-Associated Acute Hepatitis

Human parvovirus (HPV) B19 is linked to a variety of clinical manifestations, such as erythema infectiosum, nonimmune hydrops fetalis, and transient aplastic anemia. Although a few cases have shown HPVB19 infection as a possible causative agent for hepatitis-associated aplastic anemia (HAAA) in immunocompetent patients, most reported cases of HAAA following transient hepatitis did not have delayed remission. Here we report a rare case of severe aplastic anemia following acute hepatitis with prolonged jaundice due to HPVB19 infection in a previously healthy young male. Clinical laboratory examination assessed marked liver injury and jaundice as well as peripheral pancytopenia, and bone marrow biopsy revealed severe hypoplasia and fatty replacement. HPVB19 infection was diagnosed by enzyme immunoassay with high titer of anti-HPVB19 immunoglobulin M antibodies. Immunosuppressive therapy was initiated 2 months after the onset of acute hepatitis when liver injury and jaundice were improved. Cyclosporine provided partial remission after 2 months of medication without bone marrow transplantation. Our case suggests that HPVB19 should be considered as a hepatotropic virus and a cause of acquired aplastic anemia, including HAAA.

Platelet hyperaggregability is associated with decreased ADAMTS13 activity and enhanced endotoxemia in patients with acute cholangitis

Insufficient ADAMTS13 activity (ADAMTS13:AC) leads to increased levels of unusually large von Willebrand factor (VWF) multimers and causes microcirculatory disturbance and multiple organ failure (MOF). Endotoxin (Et) triggers the activation of coagulation and cytokine cascades, leading to MOF in severe inflammatory response syndrome. Here, we investigated the potential role of endotoxemia‐related ADAMTS13 in acute cholangitis.