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Background: Hepatocyte growth factor (HGF), a potent mitogen for hepatocytes, enhances hepatocyte function without stimulating proliferation, depending on the physiological conditions. p53, a transcription factor, suppresses the cell proliferation by expressing p21WAF1/CIP1 in various tissues. Aim: To investigate the mechanism through which the hepatocytes maintain mitotically quiescent even in the presence of HGF. Methods: We studied the relationship between p53 and p21 expression and the effect of p53-p21 axis on hepatocyte proliferation in primary cultured rat hepatocytes stimulated by HGF. Hepatic p21 levels are determined serially after partial hepatectomy or sham operation in rats. Results: DNA synthesis was markedly increased by HGF addition in rat hepatocytes cultured at low density but not at high density. Cellular p53 levels increased in the hepatocytes cultured at both the densities. p21 levels were increased and correlated with cellular p53 levels in hepatocytes cultured at high density but not at low density. When the activity of p53 was suppressed by a chemical inhibitor for p53, cellular p21 levels were reduced, and DNA synthesis was increased. Similarly, p21 antisense oligonucleotide increased the DNA synthesis. In rats after partial hepatectomy, transient elevation of hepatic p21 levels was observed. In contrast, in sham-operated rats, hepatic p21 levels were increased on sustained time scales. Conclusion: p53-related induction of p21 may suppress hepatocyte proliferation in the presence of HGF in the setting that mitogenic activity of HGF is not elicitable. [ABSTRACT FROM AUTHOR]

Liver regeneration is considered to be retarded or suppressed in patients with acute liver failure. However, the mechanisms for this suppression remain to be elucidated. In order to evaluate deficiencies in liver regeneration in patients with acute liver failure, we focused on the cross-communication of growth-associated factors in experimental models. In primary cultured rat hepatocytes, the levels of cellular p53 and transforming growth factor-alpha (TGF-alpha), as well as DNA synthesis increased by the addition of hepatocyte growth factor (HGF). When p53 activity was suppressed, TGF-alpha expression and DNA synthesis were reduced. DNA synthesis was also reduced when TGF-alpha activity was suppressed. In rats after partial hepatectomy, hepatic HGF and p53 protein levels increased, followed by an increase of hepatic TGF-alpha levels and hepatocyte proliferation. Circulating levels of HGF and TGF-alpha correlated with changes in the hepatic levels. The suppression of TGF-alpha activity reduced the proliferation of hepatocytes in these rats. In patients suffering from acute hepatitis, serum HGF levels increased followed by an increase of serum TGF-alpha levels. In contrast, in patients with acute liver failure, the increase of serum TGF-alpha levels was suppressed depending on the severity of hepatic failure, even though serum HGF levels markedly increased. The patients' hepatic levels were consistent with serum levels. Cross-communication of growth associated factors may be important in the progression of liver regeneration, and impaired regenerative capacity in patients with acute liver failure may be attributable, at least in part, to a disruption of communication of growth-associated factors. [ABSTRACT FROM AUTHOR]

Abstract: Amino acids regulate cellular functions in a variety of cell types. Most notably, leucine stimulates protein production through the mammalian target of rapamycin (mTOR)-dependent signaling pathway. We investigated the effect of amino acids on hepatocyte growth factor (HGF) production. Treatment with glutamine and proline, as well as leucine, increased HGF levels in the culture medium of a rat hepatic stellate cell clone in a dose-dependent manner. Up-regulation of phosphorylation of 70kDa ribosomal protein S6 kinase and eukaryotic initiation factor 4E-binding protein 1 was not apparent in the cells after treatment with glutamine or proline. When rats received injections of glutamine or proline, hepatic and circulating HGF levels increased and peaked around 12h after treatment. Glutamine and proline may have the potential to stimulate HGF production but the mechanism underlying this stimulation seems not to be through the mTOR-dependent signaling pathway. [Copyright &y& Elsevier]

Abstract: Branched chain amino acids modulate various cellular functions in addition to providing substrates for the production of proteins. We examined the mechanism underlying the stimulation by leucine of hepatocyte growth factor (HGF) production by hepatic stellate cells. Both p70 S6 kinase activity and phosphorylation of eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) were up-regulated rapidly after leucine treatment of a rat hepatic stellate cell clone. No such activation was observed following treatment with valine or isoleucine. Rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), suppressed leucine-induced activation of p70 S6 kinase and 4E-BP1 and negated the stimulatory effect of leucine on HGF production. An mTOR-dependent signaling pathway mediates the stimulatory effect of leucine on the production of HGF by hepatic stellate cells. [Copyright &y& Elsevier]

Background: Rapamycin is a specific inhibitor of the mammalian target of rapamycin (mTOR). The effect of rapamycin on proliferation and cellular function was studied in hepatocytes stimulated by hepatocyte growth factor (HGF) or transforming growth factor-α (TGFα). Methods and Results: When isolated rat hepatocytes were cultured at low density, the addition of HGF or TGFα increased DNA synthesis but did not affect albumin or fibrinogen concentrations in the medium. In contrast, in hepatocytes cultured at high density, the albumin and fibrinogen concentrations, but not DNA synthesis, were increased by HGF or TGFα. The HGF- or TGFα-induced increase in DNA synthesis and in albumin or fibrinogen concentrations was suppressed by the addition of rapamycin, as well as wortmannin, a phosphatidylinositol-3 kinase inhibitor. Conclusion: HGF and TGFα stimulate proliferation and function of hepatocytes depending upon the conditions, and rapamycin inhibited these stimulatory effects, possibly by inhibiting the mTOR-dependent signaling pathway. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Although the functions associated with differentiation are thought to be suppressed when cells proliferate, recent studies have shown that several mitogens can stimulate functions such as protein production under certain physiological conditions. Hepatocyte growth factor (HGF) is now considered to be a pluripotent factor and has been shown to stimulate the differentiated functions of hepatocytes, as well as their proliferation. The use of HGF for the treatment of liver disease, especially hepatic failure, has been suggested. Because patients with decompensated liver cirrhosis have decreased plasma concentrations of branched-chain amino acids (BCAAs), many investigations in laboratory animals and patients have been designed to demonstrate the benefits of supplementation of BCAAs on the hepatic metabolism of proteins. However, the mechanisms involved in the specific actions of BCAAs remain to be elucidated. Amino acids are molecules that modulate numerous cellular functions. BCAAs are known to influence gene expression, cellular metabolism, amino acid transport, and protein turnover. In this paper, we show the potential of BCAAs for stimulating HGF synthesis in the liver and discuss the possibility that BCAAs stimulate protein production by hepatocytes through the induction of HGF. [Copyright &y& Elsevier]

Hepatocyte growth factor (HGF) has pleiotropic effects. Up-regulation of HGF activity in vivo may be beneficial. Branched-chain amino acids (BCAAs) are known to modulate various cellular functions. When starved rats received intraperitoneal injections of valine, leucine or isoleucine, only leucine treatment increased both hepatic and circulating levels of HGF in a dose-dependent manner, up to 1.5 and 2.3 times higher, respectively, than in controls. When young growing rats with free access to food were injected with leucine once a day for a week, HGF levels and liver weights were significantly higher than those of control rats. Furthermore, 1 week of leucine treatment of adult rats resulted in elevated serum albumin levels with an increase in HGF levels. Taken together with our previous report showing that leucine stimulates HGF production by hepatic stellate cells in culture, leucine, among BCAAs, may induce an increase in HGF production by the liver in vivo. [Copyright &y& Elsevier]

Amino acids can serve as regulatory molecules that modulate numerous cellular functions. Branched chain amino acids (BCAAs) are known to exert influences on cellular metabolism, amino acid transport, protein turn over, and gene expression. However, the mechanisms involved in the specific effect of BCAAs have not been clarified. BCAA supplementation therapy is a current treatment for patients with liver cirrhosis, therefore, specific BCAA activities should be examined. Hepatocyte growth factor (HGF) is considered to be a pleiotropic factor, and is reported to modulate gene expression and to stimulate the proliferation and functions of many cell types, including hepatocytes. A potential application of HGF for several types of diseases has been postulated. Here, we describe the potential of BCAAs as a therapeutic agent that acts through the induction of HGF production in the liver. [Copyright &y& Elsevier]

Fatty livers are vulnerable to ischemia/reperfusion (I/R) injury. We investigated the role of hepatic macrophages in the I/R injury in the fatty liver. Rats with alcoholic or nonalcoholic fatty liver were subjected to hepatic warm ischemia for 30 min. A bolus of gadolinium chloride (GdCl3) was injected intravenously twice before I/R to block hepatic macrophage activity. Alcoholic fatty liver developed more extensive hepatic necrosis with neutrophil infiltration in association with a higher production of cytokine-induced neutrophil chemoattractant (CINC)-1, a potent neutrophil chemokine in rat, after I/R than the nonalcoholic fatty liver or control liver without steatosis. Hepatic apoptosis after I/R increased to a similar degree (3-fold) in each of the two fatty liver models, compared with the control liver. Alcoholic fatty liver exposed to I/R showed a rapid increase in nuclear factor-kappa B (NF-κB) binding activity. The GdCl3 pretreatment significantly reduced NF-κB binding activity, CINC-1 level and necrosis in alcoholic fatty liver, despite no significant decrease in the extent of apoptosis. Our results suggest that the activation of hepatic macrophages in alcoholic fatty liver may contribute to hepatic necrosis after I/R, and that the apoptosis might be less dependent on the macrophage activity. [Copyright &y& Elsevier]

Branched-chain amino acids (BCAAs) modulate various cellular functions, in addition to providing substrates for the production of proteins. In this study, we examined the effect of BCAAs on the secretion of hepatocyte growth factor (HGF) by hepatic stellate cells. A hepatic stellate cell clone was cultured in medium supplemented with various concentrations of valine, leucine, or isoleucine. Of these BCAAs, leucine markedly induced an increase in the levels of HGF in the medium in a dose-dependent manner. The addition of valine or isoleucine had no significant effect on HGF levels in the medium. The difference in levels of HGF in the medium between leucine-treated and non-treated cells was enhanced by the incubation period. These results demonstrate that, among BCAAs, leucine stimulates the secretion of HGF by cultured hepatic stellate cells. [Copyright &y& Elsevier]

The author comments on a study on the sex difference that exists in the prevalence of nonalcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). He references various studies including one by Yumiko Anezaki et al in an issue of "Hepatology Research." In the study, female hepatocyte-specific Pten-knockout mice were reported to be less prone to the development of hepatic steatosis and inflammation compared to the male mice. The author also argues that sex difference in NAFLD and NASH animal models is highlighted but is complicated.

Aim Methods Results Conclusion Patients with chronic hepatitis B virus (HBV) infection experiencing viral breakthrough (BTH) or partial response (PR) during lamivudine (LAM) or entecavir hydrate (ETV) administration often took ETV plus tenofovir alafenamide fumarate (TAF) due to the emergence of a drug‐resistance mutation. However, in patients lacking drug‐resistance mutation against TAF, sufficient antiviral effects may be achievable with TAF monotherapy. We assessed the drug‐resistance profile through nucleotide sequences of HBV pregenome RNA, and subsequently changed to TAF monotherapy from ETV plus TAF.This prospective study included 25 patients with serum HBV‐DNA below 20 IU/mL under ETV plus TAF administration. Pregenome RNA nucleotide sequences of HBV in the sera were analyzed using direct sequencing and deep sequencing. ETV was discontinued in patients without rtA194T and rtS106C + rtH126Y + rtD134E + rtL269I quadruple mutations in direct sequencing.LAM‐PR, LAM‐BTH, ETV‐PR, and ETV‐BTH were observed in 1, 16, 7, and 1 patient(s), respectively. Pregenome RNA nucleotide sequences were analyzable in 20 patients. Among the 12 patients classified as LAM‐BTH, six patients showed rtL180M + rtM204V/I in direct sequencing, and one patient showed minor clones containing rtL180M + rtM204V + A194T in deep sequencing at a frequency of 0.3%. In the six patients classified as ETV‐PR, one patient harbored rtM204I. No clones showing rtS106C + rtH126Y + rtD134E + rtL269I quadruple mutation were detected in deep sequencing. Subsequently, ETV was discontinued, and serum HBV‐DNA remained undetectable up to 48 weeks in all patients.Patients receiving ETV plus TAF due to partial response or BTH during initial LAM or ETV administration were able to safely transition to TAF monotherapy based on nucleotide sequences of HBV pregenome RNA in the sera. [ABSTRACT FROM AUTHOR]

Aim: To determine the outcomes concerning portal venous blood flow and portosystemic shunts in patients with decompensated cirrhosis due to hepatitis C virus (HCV) infection who achieved sustained viral response (SVR) following antiviral therapy. Methods: Portal hypertension‐related events and liver function were evaluated in 24 patients achieving SVR following sofosbuvir plus velpatasvir therapy. Results: Serum albumin level (median; g/dL) increased from 2.9 at baseline to 3.5 at 12 weeks after the end of treatment (EOT) (p = 0.005), while liver volumes (cm3) decreased from 1260 to 1150 (p = 0.0002). Portal hypertension‐related events developed in 10 patients (41.7%), and the cumulative occurrence rates after the EOT were 29.2%, 33.3%, and 46.1% at 24, 48, and 96 weeks, respectively. Multivariate logistic regression analysis revealed that the maximal diameter of the shunts (p = 0.0235) was associated with the development of the events, with a cut‐off value of 8.3 mm (p = 0.0105). Meanwhile, multiple linear regression analysis revealed that portal venous blood flow, liver volume, serum albumin, and bilirubin levels at baseline were associated with serum albumin levels at 12 weeks after EOT (p = 0.0019, p = 0.0154, p = 0.0010, and p = 0.0350, respectively). Conclusion: In patients with decompensated cirrhosis due to HCV infection, the baseline portal venous blood flow and liver volume and function were predictive of liver function following SVR, while the maximal diameter of portosystemic shunts predicted the occurrence of portal hypertension‐related events. [ABSTRACT FROM AUTHOR]

Background: The Japanese guidelines for the treatment of cirrhosis suggest zinc supplementation to prevent hepatic encephalopathy in patients with cirrhosis and zinc deficiency, although the factors that are associated with therapeutic efficacy remain unknown. Method: A total of 159 patients with chronic liver diseases but without previous zinc supplementation were analyzed. Factors associated with serum zinc levels as well as the therapeutic efficacy of zinc supplementation were evaluated. Result: Serum zinc levels decreased with the progression of liver diseases. A multiple linear regression analysis revealed that the serum levels of albumin and cholinesterase and the daily furosemide dose were independently associated with the serum zinc levels. The optimal furosemide cut‐off dosage for patients with zinc deficiency (<60 μg/dl) was 5 mg/day. Among 34 patients receiving zinc acetate hydrate, overt hepatic encephalopathy occurred in 12 patients (35.4%). A multivariate analysis identified a minimal serum zinc level of 50 μg/dl after more than 12 weeks of zinc supplementation as a factor associated with overt encephalopathy development, while furosemide use was not associated. The Child‐Pugh score at baseline was the only factor associated with the maintenance of sufficient serum zinc levels. Conclusion: Although the furosemide dose was negatively correlated with the serum zinc level in patients with chronic liver diseases, furosemide use was not associated with the occurrence of overt encephalopathy in those receiving zinc supplementation. Serum zinc levels of ≥50 μg/dl were required to prevent overt encephalopathy development during zinc supplementation in both patients with and those without furosemide administration. [ABSTRACT FROM AUTHOR]

Aim: To establish a therapeutic strategy for cirrhosis patients with gastric variceal bleeding. Methods: The outcomes of 137 patients with bleeding gastric varices were evaluated. Results: The bleeding source was gastroesophageal varices (GOV) in 86 patients, and gastric fundal varices (FV) in 51 patients. The Child-Turcotte-Pugh classes were A, B, and C in 26, 79, and 32 patients, respectively; 34 patients (24.8%) had hepatocellular carcinoma (HCC), of which 11 also had complicating portal venous tumor thrombosis (PVTT). Patients with GOV were treated by endoscopic variceal ligation or endoscopic injection sclerotherapy (EIS) with ethanolamine oleate, while those with FV were treated by EIS with cyanoacrylate; 29 patients with FV also underwent additional balloon-occluded retrograde transvenous obliteration (BRTO). Hemostasis was successfully achieved in 136 patients (99.3%), and the cumulative 1-year, 3-year, and 5-year rebleeding rates were 18.1%, 30.8%, and 30.8%, respectively, in the patients with GOV, and 2.2%, 12.5% and 12.5%, respectively, in the patients with FV. The overall 1-year, 3-year, and 5-year survival rates were 79.7%, 71.5% and 64.4%, respectively, in the patients with GOV, and 91.0%, 76.9% and 59.5%, respectively, in the patients with FV. Multivariable analysis identified PVTT and alcoholic cirrhosis as a significant risk factor associated with rebleeding, model for end-stage liver disease (MELD) score and PVTT as significant factors associated with survival. Conclusions: Endoscopic therapies with or without BRTO appeared to be useful therapeutic strategies to prevent rebleeding in patients with gastric variceal bleeding, and favorable outcomes were obtained, except in patients with underlying HCC associated with PVTT and/or severe liver damage. [ABSTRACT FROM AUTHOR]

Background: To evaluate the long-term efficacy of switching of the nucleos(t)ide analog used for treatment from entecavir (ETV) to tenofovir alafenamide fumarate (TAF) in patients with chronic HBV infection. Methods: A total of 103 patients with serum HBsAg levels of ≥100 IU/mL who had received ETV were enrolled. The nucleos(t)ide analog used for the treatment was switched from ETV to TAF, and the changes in serum HBsAg levels during the 144-week period before and after the drug switching were compared in 74 patients who had received ETV at least for 192 weeks. Results: Significant decreases of serum HBsAg levels were observed during both the ETV and the TAF administration period, although the degree of reduction was greater during the latter period than during the former period (P<0.001). Significant decreases of serum HBsAg levels were seen in both patients with genotype B HBV infection and genotype C HBV infection, irrespective of the serum HBsAg and HBcrAg levels at the time of the drug switching. Conclusion: Switching of the nucleos(t)ide analog used for treatment from ETV to TAF merits consideration in patients with chronic HBV infection, since the extent of reduction of the serum HBsAg level was greater during the TAF treatment period than during the ETV treatment period. [ABSTRACT FROM AUTHOR]

Background: The significance of the 2018 Japanese diagnostic criteria for acute-on-chronic liver failure (ACLF) has not yet been evaluated. Methods: A nationwide survey was performed for patients with ACLF occurring between 2017 and 2019. Cirrhotic patients with a Child–Pugh score of 5–9 were diagnosed as having ACLF when liver failure (serum bilirubin level of ≥ 5.0 mg/dL and a prothrombin time international normalization rate [INR] of ≥ 1.5) occurred within 28 days after an acute insult. Patients who fulfilled either criterion (total serum bilirubin or INR) and/or those with indeterminate Child–Pugh scores at baseline were also enrolled. Results: Among the 501 enrolled patients, 183 patients (37%) were diagnosed as having ACLF. The etiologies of the cirrhosis and acute insults were alcohol intake/abuse in 114 (62%) and 75 (41%) patients, respectively. Sixty-eight patients (37%) were also diagnosed as having severe alcoholic hepatitis. The survival rate without liver transplantation was 48% among the ACLF patients and 71% in the remaining patients (P < 0.01). A multivariate analysis revealed that the disease condition was significantly associated with mortality, with an odds ratio of 2.025 in ACLF patients relative to the remaining patients (P < 0.01), and patient age and the number of organs with functional failure were also associated with mortality among the ACLF patients. Conclusion: The proposed diagnostic criteria for ACLF were useful for identifying cirrhotic patients with an unfavorable outcome following acute insults. A therapeutic strategy for patients with severe alcoholic hepatitis should be established, since such patients accounted for the majority of ACLF patients. [ABSTRACT FROM AUTHOR]

Type I procollagen C-proteinase enhancer (PCPE) exists in hepatic stellate cells (HSCs) which can produce collagen. The deduced amino acid sequence of PCPE contains motifs specific for RNA-binding proteins. The effect of PCPE on the syntheses of collagen and noncollagenous protein was studied using an HSC clone derived from cirrhotic rat liver. When the cells were cultured in the presence of an antisense oligonucleotide (AS) against PCPE mRNA, the synthesis of noncollagenous protein as well as collagen was reduced compared to the cells cultured with addition of a nonsense oligonucleotide (NS). The extent of the reduction was similar in both syntheses. The total RNA content of the AS-treated cells and NS-treated cells did not differ. In the presence of actinomycin D, however, such total RNA content was decreased more rapidly in the AS-treated cells than in the NS-treated cells. PCPE may be involved in stabilization of RNA strands in noncollagenous protein synthesis as well as collagen synthesis. [Copyright &y& Elsevier]

Aim: To optimize the therapeutic strategy for patients with decompensated cirrhosis manifesting hepatic ascites and/or edema, factors affecting the outcome of patients receiving tolvaptan were evaluated. Methods: The subjects were 165 patients receiving tolvaptan including 116 patients (70%) also treated with furosemide. The therapeutic efficacy of tolvaptan was defined as "effective" when a body weight reduction of 1.5 kg or more was obtained within 1 week. The long‐term outcome was defined as "favorable" when the ascites‐related events‐free duration was prolonged following tolvaptan treatment, compared with that before treatment, or ascites‐related events were absent for at least 120 days during treatment based on the hazard function analysis. Results: Tolvaptan was effective in 115 patients (70%). Among them, the long‐term outcome was evaluated in 99 patients and was favorable in 70 patients (71%). A multivariate analysis revealed that the serum blood urea nitrogen levels at baseline (odds ratio 0.960 per +1 mg/dL, P = 0.021) and the type of tolvaptan initiation (planned vs. emergent; 3.695, P < 0.001) were associated with therapeutic efficacy, while the furosemide dose (0.280 per +20 mg/day, P = 0.014) and previous ascites‐related events (0.074, P < 0.001) were associated with the long‐term outcome. Receiver operating curve analyses identified the optimal cut‐off values for the furosemide dose as 15 mg/day (P < 0.001). Furthermore, the cumulative survival rates in patients receiving furosemide at 15 mg/day or less were significantly higher than those in the remaining patients (P = 0.048). Conclusion: Furosemide given at baseline contributed to an unfavorable outcome in patients receiving tolvaptan; consequently, tolvaptan should be given before increasing the furosemide dose. [ABSTRACT FROM AUTHOR]

Aim: To optimize the therapeutic strategy for cirrhotic patients manifesting hepatic encephalopathy, factors affecting the outcome of patients receiving rifaximin were evaluated. Methods: The subjects were 95 patients receiving rifaximin. Serum ammonia levels were measured serially during rifaximin treatment. Factors associated with long‐term outcomes and cumulative survival rates were evaluated. Results: Serum ammonia levels were decreased at 4 weeks after rifaximin treatment compared to the levels at baseline even in patients receiving rifaximin as an add‐on therapy with lactitol hydrate (P < 0.001) and reduction values were negatively correlated with the maximal diameter of portosystemic shunts (r = −0.275, P = 0.009). Overt encephalopathy occurred in 37 patients (38.9%) during rifaximin treatment, and the hazard function analysis identified 90 days as a high‐risk term for developing the first‐time overt encephalopathy. Thus, the long‐term outcome was judged as favorable in 77 patients (81.1%) in whom overt encephalopathy was absent for at least 90 days during rifaximin initiation. A multivariate analysis revealed that furosemide, especially at daily doses of ≥20 mg both at baseline and during rifaximin treatment, was a significant factor associated with unfavorable outcome (P = 0.009 and P = 0.022, respectively) as well as occurrence and recurrence of overt encephalopathy (P = 0.012). Moreover, furosemide treatment significantly deteriorated the cumulative survival rate of patients receiving rifaximin (P = 0.026). Conclusion: Furosemide contributed to the deteriorated outcome of patients receiving rifaximin. Consequently, rifaximin should be given before increasing the furosemide dose, and the furosemide dose should not be increased during rifaximin treatment. [ABSTRACT FROM AUTHOR]

Aim: This study sought to clarify the usefulness of lenvatinib for patients with unresectable hepatocellular carcinoma (HCC). Methods: The subjects were 69 patients with HCC receiving lenvatinib; the median age was 73 years, and 14 and 67 patients had been previously treated with regorafenib and/or sorafenib and therapies without molecular-targeted agents, respectively. Therapeutic efficacy was evaluated using contrast-enhanced CT images obtained 4–8 weeks after the start of lenvatinib and the middle-term outcome using Kaplan-Meier method. Results: The baseline Child-Pugh scores were 5, 6 and 7 in 31, 32 and 6 patients, respectively, and the modified albumin-bilirubin (mALBI) grades were 1, 2a and 2b in 20, 20 and 29 patients, respectively. The Barcelona Clinic Liver Cancer (BCLC) stages following downsizing after prior treatment were A, B and C in 17, 22 and 30 patients, respectively. The therapeutic efficacy was evaluated in 54 patients, and the percentages of patients achieving CR, PR, SD and PD were 3.7%, 44.4%, 37.0%, and 14.8%, respectively. The ALBI scores deteriorated significantly between 4 and 12 weeks after the start of therapy, compared with the baseline. The cumulative survival rates at 48 weeks were significantly higher among patients achieving CR/PR (95.5%) than among those showing no response (54.3%). Multivariate analyses revealed that the BCLC stages and the serum AFP levels were significantly associated with therapeutic efficacy, while the mALBI grade was associated with the middle-term outcome. Conclusions: A favorable middle-term outcome was obtained in patients with HCC receiving lenvatinib, especially in those manifesting grades 1/2a mALBI at baseline, despite the deterioration in ALBI scores during treatment. [ABSTRACT FROM AUTHOR]

Aim: Factors responsible for impaired improvement of liver function despite sustained viral response after direct‐acting antiviral agents therapies in cirrhotic patients with hepatitis C virus need to be elucidated. Methods: Liver function and the extent of portosystemic shunting were evaluated for 79 patients with compensated cirrhosis, in whom sustained viral response had been achieved after direct‐acting antiviral agents therapies for hepatitis C virus at least 3 years earlier. Results: Portosystemic shunts were observed in 63 patients (80%). Improvement and worsening, as compared with the baseline, of esophageal/gastric varices after direct‐acting antiviral agents therapies was seen in three patients (4%) and 10 patients (13%), respectively. Portal hypertension‐related events, such as varices and ascites requiring treatment, were observed in six patients (8%), in whom three patients showing worsening of Child–Pugh scores were included. Multivariate analysis showed that maximal diameter of the shunts (P = 0.012) and serum Mac‐2 binding protein glycosylation isomer levels at the end of treatment (P = 0.005) were associated with the development of portal hypertension‐related events, with cut‐off values of 5.25 mm (P = 0.001) and 6.84 cut‐off index (P < 0.001), respectively. The increase of serum albumin levels at 3 years, as compared with the baseline, was smaller in 22 patients having shunts with maximal diameters of ≥5 mm than in the remaining 57 patients (P = 0.034), whereas no such difference was seen between the patients with and without elevation of serum Mac‐2 binding protein glycosylation isomer level of ≥6.8 cut‐off index. Conclusions: A large size of portosystemic shunts was found to be a crucial determinant of impaired improvement of liver function, as well as of the development of portal hypertension‐related events, even after sustained viral response in patients with compensated cirrhosis. [ABSTRACT FROM AUTHOR]

A 42‐year‐old Chinese man with chronic hepatitis C virus (HCV) infection visited our hospital for antiviral therapy. The subgenotype could not be determined using the HCV GENOTYPE Primer Kit (Institute of Immunology, Tokyo, Japan), which can identify genotype 3a HCV exclusively among genotype 3 HCV. Thus, the whole‐genome sequence of HCV was analyzed using the MinION nanopore sequencer (Oxford Nanopore Technologies, Oxford, UK), a third‐generation single‐molecule sequencing platform. Consequently, a total of 9442 bases with a 73.6 mean depth, corresponding to the sequences between nt25 and PolyU/UC were determined (LC414155.2). The similarity analysis revealed that the obtained sequence was classified into genotype 3b HCV and showed nucleotide identities from 87.6% to 93.9% with those of 12 previously reported strains. Furthermore, possible resistance‐associated substitutions in non‐structural protein (NS)3, NS5A, and NS5B based on consensus sequences of 12 genotype 3b HCV strains, including NS5A‐Y93H and NS5B‐S282 T substitutions, were absent. In conclusion, the MinION nanopore sequencer is useful for analyzing the HCV genome, especially the genomes of genotype 3 HCV strains for which standardized real‐ time PCR methods for all subgenotypes have not been established. [ABSTRACT FROM AUTHOR]

Aim: A nationwide survey of acute liver failure (ALF) and late‐onset hepatic failure (LOHF) has revealed that the outcomes of recent patients whose diseases were caused by infection with hepatitis A virus (HAV) have worsened, compared with those of previously reported patients. The factors associated with this deterioration were evaluated. Methods: A total of 83 patients with HAV infection seen between 1998 and 2015 were enrolled. All the patients had a prothrombin time–international normalized ratio of 1.5 or more and hepatic encephalopathy of grade 2 or more severe. The demographic and clinical features of 45 patients seen prior to 2003 (cohort 1) and 38 patients seen during 2004 and thereafter (cohort 2) were compared. Results: Three and four patients in cohort 1 and cohort 2, respectively, received liver transplantations; the survival rates among the remaining patients were 56% for cohort 2 and 79% for cohort 1 (P < 0.05). The mean age (±standard deviation) of the patients was higher in cohort 2 than in cohort 1 (58 ± 11 vs. 48 ± 13 years; P < 0.01). The percentages of patients with underlying metabolic diseases were 22% in cohort 1 and 61% in cohort 2 (P < 0.01). Diabetic mellitus was more common among deceased patients than among rescued patients (29% vs. 8%; P < 0.05) among patients who did not receive liver transplantations, and a multivariate analysis revealed that patient age and disease type were significantly and independently associated with the outcome. Conclusion: The outcomes of recent patients with ALF or LOHF caused by HAV infection have recently worsened mainly because of an increase in underlying metabolic diseases as a consequence of aging. [ABSTRACT FROM AUTHOR]

Background: This study sought to clarify the factors involved in virologic failure in patients with HCV receiving retreatment with glecaprevir/pibrentasvir (GLE/PIB) in real-world practice.Methods: Forty-two patients who had previously received direct-acting antivirals (DAAs) therapies consisting of 35, 3, 3, and 1 patient(s) with genotype (GT)-1b, GT-2a, GT-2b, and GT-3b HCV, respectively, received GLE/PIB for 12 weeks. Resistance-associated substitutions (RASs) at baseline were evaluated, and the dynamics of NS5A-RASs were assessed by deep sequencing in patients showing virologic failure.Results: Baseline NS5A-RASs were found in all the patients with GT-1b HCV including 16 patients with NS3-RASs. In contrast, both NS5A-RASs and NS3-RASs were absent in 3 and 2 patients with GT-2a and GT-2b HCV, respectively. Virologic failure occurred in 3 patients with GT-1b HCV with NS5A-P32del, while a sustained virologic response (SVR) was achieved in the remaining 39 patients including those with GT-1b HCV carrying NS5A-L31V + Y93H and NS5A-A92K. Virologic failure even occurred in a patient in whom the NS5A-P32del HCV strains had become undetectable by direct sequencing, and the percentage of such strains relative to the total HCV strains was 10%, as determined by deep sequencing. In the other patient with GT-1b HCV with NS5A-P32del, NS3-A156A/V/S were found at 4 weeks after GLE/PIB therapy, but had disappeared at 11 weeks, as determined by direct sequencing.Conclusions: GLE/PIB was effective for patients with HCV who failed to achieve an SVR after prior DAA therapies except in those with GT-1b HCV carrying NS5A-P32del even when such strains became undetectable by direct sequencing. [ABSTRACT FROM AUTHOR]

Aims: Liver injury can occur during antiviral therapies with direct-acting antivirals (DAAs), potentially necessitating discontinuation of the therapies, with consequent worsening of the sustained viral response (SVR) rates, in patients with hepatitis C virus (HCV). To clarify the mechanisms involved in serum transaminase level elevation, we performed a retrospective evaluation of the serum concentrations of daclatasvir and asunaprevir, both classified as DAAs, in patients receiving treatment with a combination of the two drugs. Methods: Subjects were 278 Japanese patients with genotype-1b HCV who received daclatasvir plus asunaprevir therapy for more than 4 weeks. Serum concentrations of both the DAAs were measured at 4 weeks after the initiation of therapy. Result: Liver injuries including serum AST and/or ALT level elevation to 150 U/L or over were found in 34 patients (12.2%). Multivariate logistic regression analysis identified serum asunaprevir concentrations as being significantly associated with developing liver injury, with an odds ratio of 1.046 (95% confidence interval 1.011–1.082, p<0.05). Serum asunaprevir concentrations showed correlation with the extent of liver fibrosis, estimated by peripheral platelets counts and serum albumin levels and baseline and FIB4 index and serum Mac-2 binding protein glycosylation isomer (M2BPGi) levels at 4 weeks of the therapy; the concentrations were significantly higher among patients showing 3.0 or more of M2BPGi levels than among those with the levels less than 3.0; on the other hand, no such correlation/difference was found in serum daclatasvir concentrations. Conclusion: High serum concentrations of serum asunaprevir, which were associated with the extent of liver fibrosis, appear to provoke the occurrence of liver injury in patients with genotype-1b HCV receiving combined daclatasvir plus asunaprevir therapy. [ABSTRACT FROM AUTHOR]

Background: A nationwide survey was performed to clarify the recent status of acute liver failure (ALF) and late-onset hepatic failure (LOHF) in Japan.Methods: Two-step surveys for patients with ALF and LOHF meeting the Japanese diagnostic criteria were performed annually in 782 hospitals. The clinical features of the patients were then compared to those reported in previous surveys.Results: In total, 1554 and 49 patients with ALF and LOHF, respectively, who were seen between 2010 and 2015 were enrolled. The subjects were classified into 1280 patients with hepatitis (642 non-comatose and 638 comatose) and 323 patients without hepatitis (190 non-comatose and 133 comatose). Compared with patients seen between 1998 and 2009, an older patient age and a higher percentage of underlying extrahepatic disease were observed. Although hepatitis virus infection was the most frequent etiology, the percentage of patients with this etiology had decreased, compared with previous cohorts, while the percentages of patients with drug-induced liver injuries, autoimmune hepatitis, and an indeterminate etiology had increased. Liver transplantation was performed in 170 patients (10.6%), whereas artificial liver support with plasmapheresis and/or hemodiafiltration were performed for most of the comatose patients. The outcomes of comatose patients were unfavorable, similar to previous surveys, especially the outcomes of hepatitis B virus carriers, including those with de novo hepatitis B (survival rate of 5.4% without liver transplantation).Conclusion: Although the clinical features, including the etiologies, of patients with ALF and LOHF have changed, the outcomes of patients have not improved in recent years. [ABSTRACT FROM AUTHOR]

Aim: To establish diagnostic criteria for acute‐on‐chronic liver failure (ACLF) in Japan, a multicenter pilot survey was carried out to examine the usefulness of overseas criteria in patients with chronic liver diseases manifesting acute decompensation. Methods: Patients fulfilling the Asian‐Pacific Association for the Study of the Liver (APASL), European Association for the Study of the Liver (EASL), or Chinese Medical Association (CMA) criteria for decompensation were enrolled from eight institutions in Japan, and the clinical features were evaluated. Results: Among 112 patients, 109 patients (97.3%) fulfilled the APASL criteria for decompensation; 7 patients were excluded because the decompensation had been provoked by gastrointestinal bleeding. Consequently, 102 patients (91.1%) were diagnosed as having ACLF according to the APASL definition. Among the patients who fulfilled the APASL criteria for decompensation, the etiologies of the underlying liver diseases were alcohol abuse in 59 cases (54.1%) and hepatitis B or hepatitis C virus infection in 24 (22.0%). The acute insults were alcohol abuse in 50 (45.9%), bacterial infection in 26 (23.9%), and exacerbation of underlying liver disease in 14 (12.8%). Fifty‐four patients (49.5%) satisfied the CMA criteria, but the survival rates were similar between patients who did and those who did not meet the criteria. When 84 patients with underlying cirrhosis were classified according to the EASL–Chronic Liver Failure (Clif) Consortium criteria, the survival rates differed according to grade: 67.6% (23/34) for patients without ACLF, and 41.2% (14/34) and 18.8% (3/16) for those with grade 1/2 and grade 3 ACLF, respectively. Conclusion: The APASL definition was suitable for screening Japanese patients with ACLF, including those whose conditions were triggered by gastrointestinal bleeding, and the EASL‐Clif Consortium criteria were useful for predicting outcome. [ABSTRACT FROM AUTHOR]

Aim: To improve the therapeutic efficacy of sofosbuvir/ledipasvir (SOF/LDV) for the retreatment of patients after daclatasvir/asunaprevir (DCV/ASV), a customized therapy with or without lead‐in interferon (IFN)‐β injections was formulated according to the types of resistance‐associated substitutions (RAS) in the non‐structural protein (NS)5A region of genotype 1b hepatitis C virus (HCV). Methods: Thirty‐three patients failing prior DCV/ASV received SOF/LDV for 12 weeks. Patients with HCV carrying unfavorable NS5A‐RAS and/or those previously treated with simeprevir were given lead‐in IFN‐β injections twice a day for 2 weeks; sequential changes in the NS5A‐RAS during the injection period were evaluated using deep sequencing. Results: Lead‐in injections were not undertaken in 27 patients; a sustained viral response (SVR) was achieved in 26 patients, while viral relapse occurred in 1 patient with HCV carrying NS5A‐L28M/R30H/Y93H mutations. Among the 6 patients receiving lead‐in injections, viral relapse occurred in 2 patients who had an unfavorable IFN‐λ3‐related gene single nucleotide polymorphism allele; both patients had been previously treated with simeprevir, and HCV carrying NS5A‐L31V/Y93H mutations had emerged after DCV/ASV. Deep sequencing revealed no changes in the NS5A‐RAS profiles during the lead‐in injection period in either patient. In contrast, in a patient with a favorable allele who was infected with similar unfavorable HCV strains, NS5A‐L31/Y93 wild‐type strains appeared during the injection period, enabling an SVR. Conclusion: Using customized therapies based on the NS5A‐RAS profiles, a high SVR rate was obtained after SOF/LDV in patients failing prior DCV/ASV. Lead‐in IFN‐β injections did not improve the efficacy in patients with HCV carrying unfavorable NS5A‐RAS except in those with a favorable IFN‐λ3‐related gene allele. [ABSTRACT FROM AUTHOR]

A 40‐year‐old male patient with virologic relapse after daclatasvir plus asunaprevir therapy for a serogroup 1 hepatitis C virus (HCV) infection visited our hospital for retreatment. Virologic examinations revealed that a genotype 2b HCV strain carrying both NS3‐S122N / D168A and NA5A‐R30Q / L31M / Q54H / Y93H mutations had relapsed. The patient received sofosbuvir plus ribavirin therapy, but virologic relapse occurred once again. Sequencing of the HCV genome clarified an intergenotypic recombination of 2b and 1b with an estimated crossover point between nucleotides 3114 and 3115, corresponding to the N‐terminal end of the NS3 region (DDBJ/EMBL/GenBank databases accession no. LC273304). The NS5B‐S282T mutation was not detected in the HCV strain, and resistance‐association substitutions in the NS3 and NS5A regions were similar to those at baseline. Direct sequencing of the core and NS4A regions corresponding to the targeting sites of genotyping and serogrouping, respectively, is useful to determine the combination of direct‐acting antivirals when a discrepancy is observed between the serogroup and genotype of HCV strains. [ABSTRACT FROM AUTHOR]

α-Taxilin, a binding partner of the syntaxin family, is a candidate tumor marker. To gain insight into the physiological role of α-taxilin in normal tissues, we examined α-taxilin expression by Western blot and performed immunochemical analysis in the murine gastrointestinal tract where cell renewal vigorously occurs. α-Taxilin was expressed in the majority of the gastrointestinal tract and was prominently expressed in epithelial cells positive for Ki-67, a marker of actively proliferating cells. In the small intestine, α-taxilin was expressed in transient-amplifying cells and crypt base columnar cells intercalated among Paneth cells. In the corpus and antrum of the stomach, α-taxilin was expressed in cells localized in the lower pit and at the gland, respectively, but not in parietal or zymogenic cells. During development of the small intestine, α-taxilin was expressed in Ki-67-positive regions. Inhibition of cell proliferation by suppression of the Notch cascade using a γ-secretase inhibitor led to a decrease in α-taxilin- and Ki-67-positive cells in the stomach. These results suggest that expression of α-taxilin is regulated in parallel with cell proliferation in the murine gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Abstract: Background: The clinical significance of autotaxin (ATX), a key enzyme for the production of the bioactive lysophospholipid lysophosphatidic acid remains unknown. Serum ATX enzymatic activity reportedly increases in parallel with liver fibrosis and exhibits a gender difference. Methods: Serum ATX antigen level, measured easier than the activity, was evaluated as a marker of liver fibrosis in 2 cohorts of chronic liver disease caused by hepatitis C virus. Results: In the first cohort, serum ATX level correlated significantly with liver fibrosis stage and was the best parameter for prediction of cirrhosis with an area under the receiver operating characteristic curve (AUROC) of 0.756 in male and 0.760 in female, when compared with serum hyaluronic acid and aminotransferase-to-platelet ratio index, an established marker of liver fibrosis. In another cohort, serum ATX level correlated significantly with liver stiffness, a novel reliable marker of liver fibrosis, being the second-best parameter in male (AUROC, 0.799) and in female (AUROC, 0.876) for prediction of significant fibrosis, and the best parameter in male (AUROC, 0.863) and the third-best parameter in female (AUROC, 0.872) for prediction of cirrhosis, both of which were judged by liver stiffness. Conclusions: Serum ATX level may be a novel marker of liver fibrosis. [Copyright &y& Elsevier]

Abstract: Background: Bioactive lipid mediator S1P has been suggested to play pathophysiological roles in various fields of clinical science as a circulating paracrine mediator. We previously established a reliable method of measuring plasma S1P concentration, and reported that the one in healthy subjects has a gender difference and a correlation with red blood cell (RBC)-parameters, however, the reports of S1P measurements in the blood in patients with a specific disease have been scarce. Because our previous evidence suggests that S1P is involved in liver pathophysiology, we examined plasma S1P concentration in chronic hepatitis C patients. Methods: S1P assay was performed using a high-performance liquid chromatography system. Results: Plasma S1P concentrations were reduced in chronic hepatitis C patients compared with in healthy subjects with the same hemoglobin concentration, irrespective of gender. Among the blood parameters, serum hyaluronic acid concentration, a surrogate marker for liver fibrosis, was most closely and inversely correlated with plasma S1P concentration. Furthermore, plasma S1P concentration decreased throughout the progression of carbon tetrachloride-induced liver fibrosis in rats. Conclusions: Plasma S1P concentration was reduced in chronic hepatitis C patients, and liver fibrosis might be involved, at least in part, in the mechanism responsible for this reduction. [Copyright &y& Elsevier]

A protective effect of Rho-kinase inhibitor on various organ injuries is gaining attention. Regarding liver injury, Rho-kinase inhibitor is reported to prevent carbon tetrachloride (CCl4)- or dimethylnitrosamine-induced liver fibrosis and hepatic ischemia-reperfusion injury in rats. Because Rho-kinase inhibitor not only improved liver fibrosis but also reduced serum alanine aminotransferase (ALT) level in CCl4-induced liver fibrosis, we wondered whether Rho-kinase inhibitor might exert a direct hepatocyte-protective effect. We examined this possibility in acute CCl4 intoxication in rats. Rho-kinase inhibitor, HA-1077, reduced serum alanine ALT level in rats with acute liver injury induced by CCl4 with the improvement of histological damage and the reduction of the number of apoptotic cells. In cultured rat hepatocytes in serum-free condition, HA-1077 reduced apoptosis evaluated by quantitative determination of cytoplasmic histone-associated DNA oligo-nucleosome fragments with the reduction of caspase-3 activity and the enhancement of Bcl-2 expression. HA-1077 stimulated phosphorylation of Akt, and wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3-kinase)/Akt pathway, abrogated the reduction of hepatocyte apoptosis by HA-1077 in vitro. Furthermore, wortmannin abrogated the reduction of serum ALT level by HA-1077 in rats with acute liver injury induced by CCl4, suggesting that the activation of PI3-kinase/Akt pathway may be involved in the hepatocyte-protective effect by Rho-kinase inhibitor in vivo. In conclusion, Rho-kinase inhibitor prevented hepatocyte damage in acute liver injury induced by CCl4 in rats and merits consideration as a hepatocyte-protective agent in liver injury, considering its direct antiapoptotic effect on hepatocytes in vitro. [ABSTRACT FROM AUTHOR]

Abstract: Lysophosphatidic acid (LPA) is a lipid mediator with multiple biological actions. We have reported that LPA stimulates hepatic stellate cell proliferation and inhibits DNA synthesis in hepatocytes, suggesting that LPA might play some role in the liver. We have found that plasma LPA level and serum autotaxin (ATX) activity were increased in patients with chronic hepatitis C. However, the clinical significance of LPA and its synthetic enzyme, autotaxin (ATX), is still unclear. To determine whether the increase of plasma LPA level and serum ATX activity might be found generally in liver injury, we examined the possible modulation of them in the blood in rats with various liver injuries. Plasma LPA level and serum ATX activity were increased in carbon tetrachloride-induced liver fibrosis correlatively with fibrosis grade, in dimethylnitrosamine-induced acute liver injury correlatively with serum alanine aminotransferase level or in 70% hepatectomy as early as 3 h after the operation. Plasma LPA level was correlated with serum ATX activity in rats with chronic and acute liver injury. ATX mRNA in the liver was not altered in carbon tetrachloride-induced liver fibrosis. Plasma LPA level and serum ATX activity are increased in various liver injuries in relation to their severity. Whether increased ATX and LPA in the blood in liver injury is simply a result or also a cause of the injury should be further clarified. [Copyright &y& Elsevier]

Abstract: ADAMTS13 is gaining attention, because its deficiency causes thrombotic thrombocytopenic purpura. Although its regulatory mechanism is not fully understood, we wondered if hepatic stellate cells (HSCs) play a role, because ADAMTS13 mRNA is exclusively expressed in the liver and primarily in HSCs. Plasma ADAMTS13 activity was markedly reduced in dimethylnitrosamine-treated rats, where HSC apoptosis is an essential event, but not in carbon tetrachloride- or thioacetamide-treated rats without HSC apoptosis. Furthermore, plasma ADAMTS13 activity was also reduced in 70% hepatectomized rats, where HSC loss occurs. These results suggest that HSC may be involved in the regulation of plasma ADAMTS13 activity. [Copyright &y& Elsevier]

Abstract: Use of herbal remedies in the treatment of various diseases has a long tradition in Eastern medicine and the liver diseases are not an exception. In their use, lack of elucidation of mechanism(s) as well as randomized, placebo-controlled clinical trials has been a problem. Recently, we and others reported that inchin-ko-to (TJ-135), one of herbal remedies, suppressed hepatic fibrosis in animal models. In the course of clarifying the mechanism, we directed our focus on hepatic stellate cells (HSCs), playing a pivotal role in hepatic fibrosis, and found that rat HSCs cultured with TJ-135 changed their morphology to star-like configuration with thin, slender and dendritic processes with fewer stress fibers, which might be the features in apoptosis. In fact, TJ-135 induced HSC apoptosis in a time- and concentration-dependent manner as judged by the nuclear morphology, quantitation of cytoplasmic histone-associated DNA oligonucleosome fragments and caspase 3 activity. In HSCs treated with TJ-135, increased expression of p53 and decreased expression of Bcl-2 and phosphorylated Akt and Bad were determined. HSC apoptosis is shown to be involved in the mechanisms of spontaneous resolution of rat hepatic fibrosis and the agent which induces HSC apoptosis has been shown to reduce experimental hepatic fibrosis in rats. Thus, the induction of HSC apoptosis could be the mechanism how TJ-135 works on the resolution of hepatic fibrosis. Our current data may shed light on the novel effect of the herbal remedy. [Copyright &y& Elsevier]

Although structural changes are most important to determine vascular resistance in portal hypertension, vasoactive mediators also contribute to its regulation. Hepatic stellate cells (HSCs) are assumed to play a role in modulating intrahepatic vascular resistance based on their residence in the space of Disse and capacity to contract. Because sphingosine 1-phosphate (S1P) has been shown to stimulate HSC contractility, we wondered if S1P could regulate portal pressure. S1P at 0.5–5 μM increased portal pressure in isolated rat perfused liver. This effect was abrogated in the presence of a binding antagonist for S1P2, JTE-013. Perfusion of isolated rat liver with 5 μM S1P increased Rho activity in the liver, and co-perfusion with JTE-013 cancelled S1P-induced Rho activation. Because S1P is present in human plasma at approximately 0.2 μM, S1P might readily regulate portal vascular tone in physiological and pathological status. The antagonist for S1P2 merits consideration for treatment of portal hypertension. [Copyright &y& Elsevier]

Hepatic stellate cells (HSCs) play a central role in the development of hepatic fibrosis. Recent evidence has revealed that HSCs also play a role in its resolution, where HSC apoptosis was determined. Moreover, induction of HSC apoptosis caused a reduction of experimental hepatic fibrosis in rats. Thus knowing the mechanism of HSC apoptosis might be important to clarify the pathophysiology and establish the therapeutic strategy for hepatic fibrosis. In HSCs, Rho and Rho kinase are known to regulate contraction, migration, and proliferation with modulation of cell morphology. Controversy exists as to the participation of Rho and Rho kinase on cell survival, and little is known regarding this matter in HSCs. In this study, we directed our focus on the role of the Rho pathway in the regulation of riSC survival. C3, an inhibitor of Rho, increased histone-associated DNA fragmentation and caspase 3 activity with enhanced condensation of nuclear chromatin in rat cultured HSCs. Moreover, Y-27632, an inhibitor of Rho kinase, had the same effects, suggesting that inhibition of the Rho/Rho kinase pathway causes HSC apoptosis. On the other hand, lysophosphatidic acid, which stimulates the Rho/Rho kinase pathway, decreased histone-associated DNA fragmentation in HSCs. Inhibition of the Rho/Rho kinase pathway did not affect p53, Bcl-2, or Bax levels in HSCs. Thus we concluded that the Rho/Rho kinase pathway may play a role in the regulation of HSC survival. [ABSTRACT FROM AUTHOR]

Using a rat myofibroblast-like hepatic stellate cell line, we studied the actomyosin-based cytoskeletal actions mediated by Rho-kinase and/or myosin light chain kinase (MLCK). Calmodulin/MLCK inhibitors W-7 and ML-7 attenuated cell migration dose-relatedly at concentrations from 10−6 to 10−4 M and collagen gel-contraction by the cells at 10−4 M, respectively. Rho-kinase inhibitors Y-27632 and HA1077 attenuated the gel-contraction at concentrations from 10−6 to 10−4 M, respectively. These Rho-kinase inhibitors attenuated cell migration at 10−7 M but enhanced the migration at 10−4 M, respectively. They altered cell morphology showing prominent peripheral actin bundles and sparse central stress fibers, in comparison with the calmodulin/MLCK inhibitors. Both ML-7 and Y-27632 attenuated phosphorylation of myosin regulatory light chain and cell attachment to extracellular substrate. ML-7 attenuated the activation of GTP-binding protein Rac, while Y-27632 did not. These findings suggest that the actomyosin-based cytoskeletal actions can be functionally diverse depending on the Rho-kinase-mediated pathway and the MLCK-mediated pathway. [Copyright &y& Elsevier]

A conference paper about the effect of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) and/or the related compounds of the cholesterol synthesis pathway on collagen gel-contractility, cell morphology, and/or cell-substrate attachment of hepatic stellate cells. It is concluded that HMG-CoA reductase inhibitor may modulate hepatic myofibroblast-like stellate cell line morphology, and its attachment to surrounding extracellular matrix.

Brief periods of tissue ischemia produced tissue resistance to prolonged ischemia and reperfusion, a phenomenon called ischemic preconditioning. The mechanisms of ischemic preconditioning were examined in a rat warm ischemia–reperfusion model as well as the effect of ischemic preconditioning on liver regeneration. Ischemic preconditioning decreased liver injury after warm ischemia–reperfusion, which was reversed by Kupffer cell depletion. Ischemic preconditioning stimulated Kupffer cells to produce reactive oxygen species. Scavengers of reactive oxygen species reversed the effect of ischemic preconditioning, and pretreatment with sublethal dose of hydrogen peroxide mimicked ischemic preconditioning effect. Rat livers were preconditioned by ischemia and subjected to 70% partial hepatectomy. Liver regeneration was then evaluated serially. Ischemic preconditioning promoted liver regeneration, which was reversed by adenosine A2 receptor antagonism and mimicked by adenosine A2 receptor agonism. Promotion of liver regeneration by ischemic preconditioning and adenosine A2 receptor agonism were reversed by Kupffer cell depletion. In conclusion, ischemic preconditioning stimulates Kupffer cells to produce reactive oxygen species, leading to hepatocyte protection against warm ischemia–reperfusion injury; and ischemic preconditioning promoted liver regeneration via adenosine A2 receptor pathway in Kupffer cells. [ABSTRACT FROM AUTHOR]