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Competing Interests: T. Inoue has received honoraria from Japan Lifeline Co., Ltd, unrelated to the submitted work. R. Kitano, M. Ibusuki, Y. Kobayashi, K. Ito, and M. Yoneda declare that they have no conflict of interest.

Background and Aims: Patients with NAFLD with significant hepatic fibrosis (Stage ≥ 2) are at increased risk of liver-related morbidity and are candidates for pharmacologic therapies. In this study, we compared the diagnostic accuracy of MEFIB (the combination of magnetic resonance elastography [MRE] and Fibrosis-4 [FIB-4]) and FAST (FibroScan-aspartate aminotransferase; combined liver stiffness measurement by vibration-controlled transient elastography, controlled attenuation parameter, and aspartate aminotransferase) for detecting significant fibrosis., Approach and Results: This prospective cohort study included 234 consecutive patients with NAFLD who underwent liver biopsy, MRE, and FibroScan at the University of California San Diego (UCSD cohort) and an independent cohort (N = 314) from Yokohama City University, Japan. The primary outcome was diagnostic accuracy for significant fibrosis (Stage ≥ 2). The proportions of significant fibrosis in the UCSD and Yokohama cohorts were 29.5% and 66.2%, respectively. Area under the receiver operating characteristic curve (95% CI) of MEFIB (0.860 [0.81-0.91]) was significantly higher than that of FAST (0.757 [0.69-0.82]) in the UCSD cohort (p = 0.005), with consistent results in the Yokohama cohort (AUROC, 0.899 [MEFIB] versus 0.724 [FAST]; p < 0.001). When used as the rule-in criteria (MEFIB, MRE ≥ 3.3 kPa and FIB-4 ≥ 1.6; FAST ≥ 0.67), the positive predictive value for significant fibrosis was 91.2%-96.0% for MEFIB and 74.2%-89.2% for FAST. When used as the rule-out criteria (MEFIB, MRE < 3.3 kPa and FIB-4 < 1.6; FAST ≤ 0.35), the negative predictive value for significant fibrosis was 85.6%-92.8% for MEFIB and 57.8%-88.3% for FAST., Conclusions: MEFIB has higher diagnostic accuracy than FAST for significant fibrosis in NAFLD, and our results support the utility of a two-step strategy for detecting significant fibrosis in NAFLD., (© 2021 by the American Association for the Study of Liver Diseases.)

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. It occurs with a prevalence of up to 25%, of which 10-20% cases progress to nonalcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. The histopathology of NASH is characterized by neutrophilic infiltration, and endotoxins from gram-negative rods have been postulated as a contributing factor. Elevations in endotoxin levels in the blood can be classified as intestinal and hepatic factors. In recent years, leaky gut syndrome, which is characterized by impaired intestinal barrier function, has become a significant issue. A leaky gut may prompt intestinal bacteria dysbiosis and increase the amount of endotoxin that enters the liver from the portal vein. These contribute to persistent chronic inflammation and progressive liver damage. In addition, hepatic factors suggest that liver damage can be induced by low-dose endotoxins, which does not occur in healthy individuals. In particular, increased expression of CD14, an endotoxin co-receptor in the liver, may result in leptin-induced endotoxin hyper-responsiveness in obese individuals. Thus, elevated blood endotoxin levels contribute to the progression of NASH. The current therapeutic targets for NASH treat steatosis and liver inflammation and fibrosis. While many clinical trials are underway, no studies have been performed on therapeutic agents that target the intestinal barrier. Recently, a randomized placebo-controlled trial examined the role of the intestinal barrier in patients with NAFLD. To our knowledge, this study was the first of its kind and study suggested that the intestinal barrier may be a novel target in the future treatment of NAFLD., Competing Interests: ANa receives grants and research support from Gilead, Mylan EPD, EA Pharma, Kowa, Taisho, and Biofermin. ANa is also a consultant for Gilead, Boehringer Ingelheim, Bristol Myers Squibb, Kowa, Astellas, EA Pharma, and Mylan EPD. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kessoku, Kobayashi, Imajo, Tanaka, Yamamoto, Takahashi, Kasai, Ozaki, Iwaki, Nogami, Honda, Ogawa, Kato, Higurashi, Hosono, Yoneda, Okamoto, Usuda, Wada, Kobayashi, Saito and Nakajima.)

The liver directly accepts blood from the gut and is, therefore, exposed to intestinal bacteria. Recent studies have demonstrated a relationship between gut bacteria and nonalcoholic fatty liver disease (NAFLD). Approximately 10-20% of NAFLD patients develop nonalcoholic steatohepatitis (NASH), and endotoxins produced by Gram-negative bacilli may be involved in NAFLD pathogenesis. NAFLD hyperendotoxicemia has intestinal and hepatic factors. The intestinal factors include impaired intestinal barrier function (leaky gut syndrome) and dysbiosis due to increased abundance of ethanol-producing bacteria, which can change endogenous alcohol concentrations. The hepatic factors include hyperleptinemia, which is associated with an excessive response to endotoxins, leading to intrahepatic inflammation and fibrosis. Clinically, the relationship between gut bacteria and NAFLD has been targeted in some randomized controlled trials of probiotics and other agents, but the results have been inconsistent. A recent randomized, placebo-controlled study explored the utility of lubiprostone, a treatment for constipation, in restoring intestinal barrier function and improving the outcomes of NAFLD patients, marking a new phase in the development of novel therapies targeting the intestinal barrier. This review summarizes recent data from studies in animal models and randomized clinical trials on the role of the gut-liver axis in NAFLD pathogenesis and progression.

Abstract: Bariatric surgery has been reported to improve non-alcoholic steatohepatitis (NASH), which is a frequent comorbidity in morbidly obese patients. We performed a retrospective cohort study to estimate the therapeutic effect of sleeve gastrectomy (SG), the most common bariatric surgery in Japan, on obese patients with NASH by comparing the findings of paired liver biopsies.Eleven patients who underwent laparoscopic SG for the treatment of morbid obesity, defined as body mass index (BMI) > 35 kg/m2, from March 2015 to June 2019 at Hiroshima University Hospital, Japan, were enrolled. All patients were diagnosed with NASH by liver biopsy before or during SG and were re-examined with a second liver biopsy 1 year after SG. The clinical and histological characteristics were retrospectively analyzed.One year after SG, body weight and BMI were significantly reduced, with median reductions in body weight and BMI of-22 kg and -7.9 kg/m2, respectively. Body fat was also significantly reduced at a median of 13.7%. Liver-related enzymes were also significantly improved. On re-examination by paired liver biopsy, liver steatosis improved in 9 of the 11 patients (81.8%), ruling out of the pathological diagnosis of NASH. However, fibrosis stage did not significantly improve 1 year after SG. The non-alcoholic fatty liver disease activity score was significantly reduced in 10 of 11 patients (90.9%).Pathological improvement or remission of NASH could be achieved in most morbidly obese Japanese patients 1 year after SG., Competing Interests: Conflict of interest and source of funding: EM is currently receiving a grant from Grants-in-Aid for Scientific Research and Development from the Ministry of Health, Labor, and Welfare and the Ministry of Education Culture Sports Science and Technology (JSPS KAKENHI grant number 18K15814). KC received a grant from the Japan Agency for Medical Research and Development (grant number JP20fk0210040). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding was received for this study. None of the remaining authors were declared., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Corticotropin-releasing factor (CRF) in the brain acts on physiological and pathophysiological modulation of the hepatobiliary system. Central CRF administration aggravates experimental acute liver injury by decreasing hepatic blood flow. Conversely, minimal evidence is available regarding the effect of centrally acting CRF on hepatic lipid metabolism and inflammation. We examined whether central CRF affects hepatic lipid metabolism and inflammation-related gene expression in rats. Male Long Evans rats were intracisternally injected with CRF (10 μg) or saline. Rats were sacrificed 2 h, 6 h, and 24 h after the CRF injection, the liver was isolated, and mRNA was extracted. Next, hepatic lipid metabolism and inflammation-related gene expression were examined. Hepatic SREBF1 (sterol regulatory element-binding transcription factor 1) mRNA levels were significantly increased 6 h and 24 h after intracisternal CRF administration when compared with those in the control group. Hepatic TNFα and IL1β mRNA levels increased significantly 6 h after intracisternal CRF administration. Hepatic sympathectomy or guanethidine treatment, not hepatic branch vagotomy or atropine treatment, inhibited central CRF-induced increase in hepatic SREBF1, TNFα and IL1β mRNA levels. These results indicated that central CRF affects hepatic de novo lipogenesis and inflammation-related gene expression through the sympathetic-noradrenergic nervous system in rats.

Prebiotics ameliorate dysbiosis and influence metabolism and the immune system, but their effects on cardiovascular complications in metabolic disorders remain largely unknown. We here investigated the effects of the soluble fiber inulin on cardiac, adipose tissue, and hepatic pathology as well as on metabolic disorders in DahlS.Z- Lepr fa / Lepr fa (DS/obese) rats, an animal model of metabolic syndrome (MetS). DS/obese rats and their homozygous lean (DahlS.Z- Lepr + / Lepr + , or DS/lean) littermate controls were fed a purified diet containing 5% or 20% inulin from 9 to 13 wk of age. The high-fiber diet ameliorated hypertension, left ventricular inflammation, fibrosis and diastolic dysfunction; attenuated adipose tissue inflammation and fibrosis; and alleviated the elevation of interleukin-6 levels, without affecting insulin resistance, in DS/obese rats. In addition, high fiber intake ameliorated lipid accumulation, inflammation, and fibrosis; attenuated the reduction in AMPK activity; upregulated sterol regulatory element-binding protein-1c gene expression; and increased the expression of microsomal triglyceride transfer protein gene in the liver of DS/obese rats. It also mitigated increases in total and non-high-density lipoprotein cholesterol levels but increased the triglyceride concentration in serum in these rats. None of these parameters were affected by high dietary fiber in DS/lean rats. The proportion of regulatory T cells in adipose tissue was influenced by dietary fiber but not by genotype. Our results indicate that inulin exacerbates hypertriglyceridemia but alleviates hypertension and cardiac injury as well as adipose tissue and hepatic pathology in MetS rats. NEW & NOTEWORTHY Prebiotics ameliorate dysbiosis and influence metabolism and the immune system, but their effects on cardiovascular complications in metabolic disorders remain largely unknown. Inulin ameliorated hypertension, cardiac injury, and diastolic dysfunction without affecting obesity or insulin resistance in a rat model of metabolic syndrome. The favorable cardiac effects of inulin may be related to inhibition of systemic inflammation associated with a reduction in circulating interleukin-6 levels. Additionally, inulin exacerbated hypertriglyceridemia but alleviates adipose tissue and hepatic pathology in these animals, as well as increased the number of regulatory T cells in adipose tissue.

The autonomic nervous system, consisting of sympathetic and parasympathetic branches, plays an important role in regulating metabolic homeostasis. The sympathetic nervous system (SNS) regulates hepatic lipid metabolism by regulating adrenergic receptor activation, resulting in the stimulation of hepatic very-low-density lipoprotein-triglyceride (TG) production in vivo. However, only a few studies on the relationship between SNS and hepatic steatosis have been reported. Here, we investigate the effect of adrenergic receptor agonists on hepatic steatosis in mice fed a high-fat diet (HFD). The α-adrenergic receptor agonist phenylephrine (10 mg/kg/d) or the β-adrenergic receptor agonist isoproterenol (30 mg/kg/d) was coadministered with HFD to male mice. After five weeks, hepatic steatosis, TG levels, and hepatic fat metabolism-related biomarkers were examined. HFD treatment induced hepatic steatosis, and cotreatment with phenylephrine, but not isoproterenol, attenuated this effect. Phenylephrine administration upregulated the mRNA levels of hepatic peroxisome proliferator-activated receptor alpha and its target genes (such as carnitine palmitoyltransferase 1) and increased hepatic β-hydroxybutyrate levels. Additionally, phenylephrine treatment increased the expression of the autophagosomal marker LC3-II but decreased that of p62, which is selectively degraded during autophagy. These results indicate that phenylephrine inhibits hepatic steatosis through stimulation of β-oxidation and autophagy in the liver.

Background: The laxative drug lubiprostone improves intestinal permeability in healthy volunteers. We aimed to assess efficacy and safety of lubiprostone in patients with non-alcoholic fatty liver disease (NAFLD) with constipation via attenuation of intestinal permeability., Methods: This randomised, double-blind, placebo-controlled, phase 2a study in Yokohama City University Hospital, Japan, recruited patients (aged 20-85 years) with NAFLD and constipation, alanine aminotransferase (ALT) at least 40 U/L, liver stiffness (≤6·7 kPa), and hepatic fat fraction at least 5·2% when assessed by MRI-proton density fat fraction. Eligible patients were randomly assigned (11:10:9) by a computer-based system and stratified by age and sex to receive 24 μg lubiprostone, 12 μg lubiprostone, or placebo, orally, once per day for 12 weeks. The primary endpoint was the absolute changes in ALT at 12 weeks. Efficacy analysis was done by intention to treat. Safety was assessed in all treated patients. This trial was registered with University Hospital Medical Information Network Clinical Trials Registry (UMIN000026635)., Findings: Between March 24, 2017, and April 3, 2018, we screened 288 patients, of whom 150 (52%) were randomly assigned to treatment: 55 patients were assigned to receive 24 μg lubiprostone, 50 to receive 12 μg lubiprostone, and 45 to receive placebo. A greater decrease in the absolute ALT levels from baseline to 12 weeks was seen in the 24 μg lubiprostone group (mean -13 U/L [SD 19]) than in the placebo group (1 U/L [24]; mean difference -15 U/L [95% CI -23 to -6], p=0·0007) and in the 12 μg lubiprostone group (-12 U/L [21]) than in the placebo group (mean difference -13 U/L [-22 to -5], p=0·0023). 18 (33%) of 55 patients in the 24 μg group had at least one adverse event, as did three (6%) of 47 patients in the 12 μg group and three (7%) of 43 in the placebo group. The most common adverse event was diarrhoea (17 [31%] of patients in the 24 μg group, three [6%] in the 12 μg group, none in the placebo group). No life-threatening events or treatment-related deaths occurred., Interpretation: Lubiprostone was well tolerated and reduced the levels of liver enzymes in patients with NAFLD and constipation. Further studies are necessary to better define the efficacy and tolerability of lubiprostone in patients with NAFLD without constipation., Funding: Mylan EPD G.K., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background and Aim: The fibrosis stage of liver is associated with the long-term outcomes in patients with non-alcoholic fatty liver disease (NAFLD). However, significant fibrosis, defined as fibrosis stages 2-4, is associated with an elevated risk of progression to severe liver disease; there have been scant reports about diagnosing significant fibrosis. We compare the noninvasive method and aim to identify appropriate liver fibrosis markers for detecting significant fibrosis in NAFLD patients., Methods: We compared the usefulness of liver fibrosis markers (Wisteria floribunda agglutinin-positive Mac-2-binding protein [WFA + -M2BP], type 4 collagen 7S, etc.), clinical scoring systems, and liver stiffness measurement obtained using vibration-controlled transient elastography and magnetic resonance imaging-based magnetic resonance elastography in the same individuals and identified the most appropriate noninvasive method for detecting significant fibrosis in 165 patients with liver biopsy-diagnosed NAFLD., Results: The area under the receiver operating characteristic curve based on the serum cutoff index values of WFA + -M2BP/the serum levels of type IV collagen 7S for the diagnosis of significant fibrosis was 0.832 (95% confidence interval: 0.771-0.894)/0.837 (95% confidence interval: 0.778-0.898). "WFA + -M2BP (cutoff index) ≥ 0.83 or type IV collagen 7S ≥ 5.2 ng/mL" showed a high sensitivity (91.4%) and negative predictive value (87.9%) for the diagnosis of significant fibrosis., Conclusions: We showed that serum WFA + -M2BP or type IV collagen 7S levels serve as useful independent markers for detecting significant fibrosis and that use of both WFA + -M2BP and type IV collagen 7S together increased the sensitivity and negative predictive value for the diagnosis of liver fibrosis. These results need to be validated in larger populations from multiple clinical centers., (© 2018 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Fourteen beta-agonists were quantitatively analyzed in cattle, chicken and swine liver specimens purchased at 14 wet markets in Selangor State, Malaysia, by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The health risks of ractopamine and clenbuterol residues in the Malaysian population were assessed based on quantitative data and meat consumption statistics in Malaysia. Wastewater samples collected at swine farms (n = 2) and cattle/cow farms (n = 2) in the Kuala Langat district were analyzed for the presence for the 14 compounds. Wastewater in chicken farms was not collected because there was negligible discharge during the breeding period. The environmental impacts caused by beta-agonists discharged from livestock farms were spatially assessed in the Langat River basin using a geographic information system (GIS). As a result, 10 compounds were detected in the liver specimens. Ractopamine, which is a permitted compound for swine in Malaysia, was frequently detected in swine livers; also, 9 other compounds that are prohibited compounds could be illegally abused among livestock farms. The health risks of ractopamine and clenbuterol were assessed to be minimal as their hazard quotients were no more than 7.82 × 10 -4 and 2.71 × 10 -3 , respectively. Five beta-agonists were detected in the wastewater samples, and ractopamine in the swine farm resulted in the highest contamination (30.1 μg/L). The environmental impacts of the beta-agonists in the Langat River basin were generally concluded to be minimal, but the ractopamine contamination released from swine farms was localized in coastal areas near the estuary of the Langat River basin because most swine farms were located in that region., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background & Aims: Noninvasive methods have been evaluated for the assessment of liver fibrosis and steatosis in patients with nonalcoholic fatty liver disease (NAFLD). We compared the ability of transient elastography (TE) with the M-probe, and magnetic resonance elastography (MRE) to assess liver fibrosis. Findings from magnetic resonance imaging (MRI)-based proton density fat fraction (PDFF) measurements were compared with those from TE-based controlled attenuation parameter (CAP) measurements to assess steatosis., Methods: We performed a cross-sectional study of 142 patients with NAFLD (identified by liver biopsy; mean body mass index, 28.1 kg/m(2)) in Japan from July 2013 through April 2015. Our study also included 10 comparable subjects without NAFLD (controls). All study subjects were evaluated by TE (including CAP measurements), MRI using the MRE and PDFF techniques., Results: TE identified patients with fibrosis stage ≥2 with an area under the receiver operating characteristic (AUROC) curve value of 0.82 (95% confidence interval [CI]: 0.74-0.89), whereas MRE identified these patients with an AUROC curve value of 0.91 (95% CI: 0.86-0.96; P = .001). TE-based CAP measurements identified patients with hepatic steatosis grade ≥2 with an AUROC curve value of 0.73 (95% CI: 0.64-0.81) and PDFF methods identified them with an AUROC curve value of 0.90 (95% CI: 0.82-0.97; P < .001). Measurement of serum keratin 18 fragments or alanine aminotransferase did not add value to TE or MRI for identifying nonalcoholic steatohepatitis., Conclusions: MRE and PDFF methods have higher diagnostic performance in noninvasive detection of liver fibrosis and steatosis in patients with NAFLD than TE and CAP methods. MRI-based noninvasive assessment of liver fibrosis and steatosis is a potential alternative to liver biopsy in clinical practice. UMIN Clinical Trials Registry No. UMIN000012757., (Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Aim: To investigate whether a glucagon-like peptide-1 (GLP-1) analogue inhibits nonalcoholic steatohepatitis (NASH), which is being increasingly recognized in Asia, in non-obese mice., Methods: A methionine-choline-deficient diet (MCD) along with exendin-4 (20 μg/kg per day, ip), a GLP-1 analogue, or saline was administered to male db/db mice (non-obese NASH model). Four or eight weeks after commencement of the diet, the mice were sacrificed and their livers were excised. The excised livers were examined by histochemistry for evidence of hepatic steatosis and inflammation. Hepatic triglyceride (TG) and free fatty acid (FFA) content was measured, and the expression of hepatic fat metabolism- and inflammation-related genes was evaluated. Oxidative stress-related parameters and macrophage recruitment were also examined using immunohistochemistry., Results: Four weeks of MCD feeding induced hepatic steatosis and inflammation and increased the hepatic TG and FFA content. The expression of fatty acid transport protein 4 (FATP4), a hepatic FFA influx-related gene; macrophage recruitment; and the level of malondialdehyde (MDA), an oxidative stress marker, were significantly augmented by a 4-wk MCD. The levels of hepatic sterol regulatory element-binding protein-1c (SREBP-1c) mRNA (lipogenesis-related gene) and acyl-coenzyme A oxidase 1 (ACOX1) mRNA (β-oxidation-related gene) had decreased at 4 wk and further decreased at 8 wk. However, the level of microsomal triglyceride transfer protein mRNA (a lipid excretion-related gene) remained unchanged. The administration of exendin-4 significantly attenuated the MCD-induced increase in hepatic steatosis, hepatic TG and FFA content, and FATP4 expression as well as the MCD-induced augmentation of hepatic inflammation, macrophage recruitment, and MDA levels. Additionally, it further decreased the hepatic SREBP-1c level and alleviated the MCD-mediated inhibition of the ACOX1 mRNA level., Conclusion: These results suggest that GLP-1 inhibits hepatic steatosis and inflammation through the inhibition of hepatic FFA influx and oxidative stress in a non-obese NASH model.

AMP-activated protein kinase (AMPK) plays an important role in insulin resistance, which is characterized by the impairment of the insulin-Akt signaling pathway. However, the time course of the decrease in AMPK and Akt phosphorylation in the liver during the development of obesity and insulin resistance caused by feeding a high fat diet (HFD) remains controversial. Moreover, it is unclear whether the impairment of AMPK and Akt signaling pathways is reversible when changing from a HFD to a standard diet (SD). Male ddY mice were fed the SD or HFD for 3 to 28 days, or fed the HFD for 14 days, followed by the SD for 14 days. We examined the time course of the expression and phosphorylation levels of AMPK and Akt in the liver by immunoblotting. After 3 days of feeding on the HFD, mice gained body weight, resulting in an increased oil red O staining, indicative of hepatic lipid accumulation, and significantly decreased AMPK phosphorylation, in comparison with mice fed the SD. After 14 days on the HFD, systemic insulin resistance occurred and Akt phosphorylation significantly decreased. Subsequently, a change from the HFD to SD for 3 days, after 14 days on the HFD, ameliorated the impairment of AMPK and Akt phosphorylation and systemic insulin resistance. Our findings indicate that AMPK phosphorylation decreases early upon feeding a HFD and emphasizes the importance of prompt lifestyle modification for decreasing the risk of developing diabetes.

Background & Aims: The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is affected by epigenetic factors as well as by genetic variation., Methods: We performed targeted-bisulfite sequencing to determine the levels of DNA methylation of 4 CpG islands (CpG99, CpG71, CpG26, and CpG101) in the regulatory regions of PNPLA3, SAMM50, PARVB variant 1, and PARVB variant 2, respectively. We compared the levels of methylation of DNA in the livers of the first and second sets of patients with mild (fibrosis stages 0 and 1) or advanced (fibrosis stages 2 to 4) NAFLD and in those of patients with mild (F0 to F2) or advanced (F3 and F4) chronic hepatitis C infection. The hepatic mRNA levels of PNPLA3, SAMM50, and PARVB were measured using qPCR., Results: CpG26, which resides in the regulatory region of PARVB variant 1, was markedly hypomethylated in the livers of patients with advanced NAFLD. Conversely, CpG99 in the regulatory region of PNPLA3 was substantially hypermethylated in these patients. These differences in DNA methylation were replicated in a second set of patients with NAFLD or chronic hepatitis C. PNPLA3 mRNA levels in the liver of the same section of a biopsy specimen used for genomic DNA preparation were lower in patients with advanced NAFLD compared with those with mild NAFLD and correlated inversely with CpG99 methylation in liver DNA. Moreover, the levels of CpG99 methylation and PNPLA3 mRNA were affected by the rs738409 genotype., Conclusions: Hypomethylation of CpG26 and hypermethylation of CpG99 may contribute to the severity of fibrosis in patients with NAFLD or chronic hepatitis C infection., (Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Objectives: Vitamin E is often used in the treatment of nonalcoholic fatty liver disease (NAFLD), including nonalcoholic steatohepatitis (NASH); however, the magnitude of treatment response associated with vitamin E in improving liver function and histology in NAFLD/NASH has not, to our knowledge, been quantified systematically. Thus, we conducted a meta-analysis of randomized controlled trials (RCTs) using vitamin E in the treatment of NAFLD/NASH., Methods: PubMed, Medline, and Cochrane Library Full Text Database, and Japan Medical-Literature Database (Igaku Chuo Zasshi) were searched until March 2014, and five RCTs were identified for meta-analysis., Results: According to a random effect model analysis of the five studies, vitamin E significantly reduced aspartate transaminase (AST) by -19.43 U/L, alanine aminotransferase (ALT) by -28.91 U/L, alkaline phosphatase (ALP) by -10.39 U/L, steatosis by -0.54 U/L, inflammation by -0.20 U/L, and hepatocellular ballooning by -0.34 U/L compared with the control group. Vitamin E treatment with NASH adult patients showed obvious reductions in not only AST of -13.91 U/L, ALT by -22.44 U/L, steatosis of -0.67 U/L, inflammation of -0.20 U/L, but also fibrosis of -0.30 U/L compared to the control treatment., Conclusions: Vitamin E significantly improved liver function and histologic changes in patients with NAFLD/NASH., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Although many of the factors and molecules closely associated with non-alcoholic steatohepatitis (NASH) have been reported, the role of inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) on the progression of NASH remains unclear. We therefore investigated the role of iNOS-derived NO in NASH pathogenesis with a long-term follow-up study using systemic iNOS-knockout mice under high-fat diet (HFD) conditions., Methods: iNOS-knockout and wild-type mice were fed a basal or HFD for 10 or 48 weeks. Lipid accumulation, fibrosis, and inflammation were evaluated, and various factors and molecules closely associated with NASH were analyzed., Results: Marked fibrosis and inflammation (indicators of NASH) were observed in the livers of iNOS-knockout mice compared to wild-type mice after 48 weeks of a HFD; however, lipid accumulation in iNOS-knockout mice livers was less than in the wild-type. Increased expressions of various cytokines that are transcriptionally controlled by NF-kB in iNOS-deficient mice livers were observed during HFD conditions., Conclusions: iNOS-derived NO may play a protective role against the progression to NASH during an HFD by preventing fibrosis and inflammation, which are mediated by NF-kB activation in Kupffer cells. A lack of iNOS-derived NO accelerates progression to NASH without excessive lipid accumulation.

Several lines of evidence have suggested a role of gut microbiota in the etiology of nonalcoholic steatohepatitis (NASH). NASH subjects reportedly showed a prolonged orocecal transit time coexistent with small intestinal bacterial overgrowth. We considered the possibility that enhanced gastrointestinal motility would influence gut microbiota and thus investigated the effects of the gastroprokinetic agent mosapride citrate (MC) on gut microbiota and the development of NASH using a methionine-choline deficient (MCD) diet-fed rodent model. Mice were divided into three groups, given the normal chow diet (NCD), the MCD diet, or the MCD diet containing 10 mg·kg(-1)·day(-1) of MC (MCD plus MC) for 6 wk. NASH development was evaluated based on hepatic histochemical findings, serum parameters and various mRNA and/or protein expression levels. MC treatment suppressed MCD diet-induced NASH development, with reduced serum lipopolysaccharide and increased plasma glucagon-like peptide-1 (GLP-1) concentrations. Calculation of the relative abundance of each strain based on gut microbiota analyses indicated lactic acid bacteria specifically, such as Bifidobacterium and Lactobacillus, in feces to be decreased in the MCD, compared with the NCD group. Interestingly, the reduction in lactic acid bacteria in the MCD diet group was reversed in the MCD plus MC group. In addition, colon inflammation observed in the MCD diet group was reduced in the MCD plus MC group. Therefore, MC showed a protective effect against MCD diet-induced NASH development in our rodent model, with possible involvements of increased fecal lactic acid bacteria, protection against colon inflammation and elevated plasma GLP-1., (Copyright © 2015 the American Physiological Society.)

Purpose: To evaluate whether arterial injection of miriplatin-iodized oil suspension facilitates ablative zone expansion by radiofrequency (RF) ablation using a Cool-Tip electrode and to provide effective tissue platinum concentration in the normal swine liver., Materials and Methods: RF ablation was performed at three sites of each liver. RF ablation alone was performed in two animals (control). Ablation was performed after arterial injection of iodized oil (iodized-oil group) or a miriplatin-iodized oil suspension (miriplatin group) in two animals each. Long- and short-axis diameters of the ablative zone were measured. In the miriplatin group, tissue platinum concentrations were measured in the ablative, surrounding hyperemic rim, and nonablative zones., Results: The mean long- and short-axis diameters of ablative zones were 27.0 ± 3.1 and 18.0 ± 0.6 mm in the control. Although the long-axis diameter (30.2 ± 2.8 mm, p = 0.07) showed no significant expansion, the short-axis diameter (20.8 ± 2.6 mm, p = 0.04) was significantly expanded more in the iodized-oil group than in the control. Ablative zone sizes were largest in the miriplatin group. The long-axis diameter (33.5 ± 2.4 mm, p = 0.01) was significantly larger than that in the control. The short-axis diameter (27.2 ± 1.9 mm, p = 0.004) was significantly larger than that of the iodized-oil group. Tissue platinum concentrations showed an effective antitumor effect (≥9 μg/g) in ablative (16.5 ± 5.7 μg/g), surrounding hyperemic rim (18.0 ± 5.1 μg/g), and nonablative zones (mean 22.2 ± 5.7 μg/g) (p = 0.21)., Conclusion: Arterial injection of miriplatin-iodized oil suspension can expand the ablative zone size and provide effective tissue platinum concentration on tumor control in the ablative zones and their surrounding hyperemic rim.

Background: Although therapeutic intervention for nonalcoholic steatohepatitis (NASH) at an early stage is important owing to the progressive nature of the disease, diagnosis using noninvasive methods remains difficult. We previously demonstrated NASH specific impairment of choline metabolism and the use of fasting plasma free choline (fCh) levels for NASH diagnosis. Here, we investigated the utility of an oral choline tolerance test (OCTT), based on disordered choline metabolism, as a novel noninvasive method for NASH diagnosis., Methods: Sixty-five patients with biopsy proven nonalcoholic fatty liver disease (NAFLD) and 17 healthy controls were enrolled. Blood samples were obtained from all subjects five times during the OCTT (before and 1, 2, 3, and 4 h after oral loading with 260 mg choline)., Results: Four-hour fCh levels after oral loading choline were markedly increased in NASH patients, compared with non-NASH subjects. For detecting NASH, compared with non-NASH subjects, the area under the curve for 4-h fCh levels was 0.829 on receiver operating characteristic (ROC) analysis. The cut-off level for NASH diagnosis was ≥0.16 mg/dL, and the sensitivity, specificity, positive predictive value, and negative predictive value were 80.1, 82.6, 78.4, and 84.4 %, respectively. Moreover, 4-h fCh levels were significantly associated with the disease activity based on NAFLD activity score in patients with NAFLD., Conclusions: Four-hour fCh levels obtained by an OCTT reflect a NASH specific disorder of choline metabolism, suggesting that the OCTT is a novel and useful noninvasive method for diagnosing NASH at an early stage with sufficient accuracy for clinical practice.

Background Aims: Liver inflammation is a risk factor for the progression of nonalcoholic fatty liver disease (NAFLD). However, the diagnosis of liver inflammation is very difficult and invasive liver biopsy is still the only method to reliably detect liver inflammation. We previously reported that overexpression of CD14 in Kupffer cells may trigger the progression to nonalcoholic steatohepatitis (NASH) via liver inflammation following hyper-reactivity to low-dose lipopolysaccharide. Therefore, the aim of this study was to investigate the relationship between soluble type of CD14 (sCD14) and histological features in patients with NAFLD., Methods: Our cohort consisted of 113 patients with liver biopsy-confirmed NAFLD and 21 age-matched healthy controls. Serum sCD14 levels were measured by an enzyme-linked immunosorbent assay., Results: Serum sCD14 levels were significantly associated with diagnosis of NASH and the area under the receiver operator characteristic curve (AUROC) to distinguish between not NASH and NASH was 0.802. Moreover, serum sCD14 levels were significantly associated with the disease activity based on NAFLD activity score and hepatic CD14 mRNA expression, which is correlated with membrane CD14 (mCD14) expression, in patients with NAFLD. In multiple regression analysis, the serum sCD14 levels were independently associated with liver inflammation. The AUROC to distinguish between mild and severe liver inflammation in patients with NAFLD was 0.752., Conclusions: We found that serum sCD14 levels increased significantly with increasing liver inflammation grade in patients with NAFLD, reflecting increased hepatic CD14 expression. Serum sCD14 is a promising tool to predict the worsening of liver inflammation, and may offer a potential biomarker for evaluation of therapeutic effects in NAFLD.

Aims/hypothesis: Epidemiological studies have revealed that obesity and diabetes mellitus are independent risk factors for the development of non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma. However, the debate continues on whether insulin resistance as such is directly associated with NASH and liver tumourigenesis. Here, we investigated the incidence of NASH and liver tumourigenesis in Irs1 ( -/- ) mice subjected to a long-term high-fat (HF) diet. Our hypothesis was that hepatic steatosis, rather than insulin resistance may be related to the pathophysiology of these conditions., Methods: Mice (8 weeks old, C57Bl/6J) were given free access to standard chow (SC) or an HF diet. The development of NASH and liver tumourigenesis was evaluated after mice had been on the above-mentioned diets for 60 weeks. Similarly, Irs1 ( -/- ) mice were also subjected to an HF diet for 60 weeks., Results: Long-term HF diet loading, which causes obesity and insulin resistance, was sufficient to induce NASH and liver tumourigenesis in the C57Bl/6J mice. Obesity and insulin resistance were reduced by switching mice from the HF diet to SC, which also protected these mice against the development of NASH and liver tumourigenesis. However, compared with wild-type mice fed the HF diet, Irs1 ( -/- ) mice fed the HF diet were dramatically protected against NASH and liver tumourigenesis despite the presence of severe insulin resistance and marked postprandial hyperglycaemia., Conclusions/interpretation: IRS-1 inhibition might protect against HF diet-induced NASH and liver tumourigenesis, despite the presence of insulin resistance.

Background/aims: The degree of hepatic fibrosis is an important factor for prognosis and management of patients with chronic liver disease; however, liver biopsy is an invasive method of measuring fibrosis. Here, we investigated the diagnostic utility of liver stiffness, as measured by transient elastography in assessing hepatic fibrosis of viral chronic liver disease and nonalcoholic fatty liver disease (NAFLD)., Methodology: Four hundred and nine eligible patients underwent transient elastography to measure liver stiffness. Liver biopsy for histopathological assessment of fibrosis (F0-F4) was performed in 71 of these patients. Serum levels of hyaluronic acid were determined in 110 patients. We assessed liver stiffness in several chronic liver diseases and compared correlations among liver stiffness, hepatic fibrosis stage and serum hyaluronic acid levels., Results: A steady stepwise increase in liver stiffness was observed with progressing severity of hepatic fibrosis (p<0.0001) in 71 patients who underwent liver biopsy. In 32 chronic viral hepatitis patients, measuring liver stiffness was useful for differentiating between F1, or F2, or F3 and F4, while in 32 NAFLD liver stiffness can differentiate between F0 and F1, F2, or F3, F1 and F3 or F4 and F2 and F4. There was no significant correlation between liver fibrotic stages and serum hyaluronic levels., Conclusions: The present data advocates measuring liver stiffness for assessing hepatic fibrosis is more sensitive in NAFLD than viral chronic diseases, and liver stiffness is useful compared to serum hyaluronic acid level in estimating hepatic fibrosis.

Acoustic Radiation Force Impulse (ARFI) imaging is a novel ultrasound-based elastography method that is integrated in a conventional ultrasound machine enabling the exact localization of measurement site. It might present an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. At present, studies with small patient population have shown promising results. A systematic review and meta-analysis of pooled patient data were performed to evaluate the overall performance of ARFI for the staging of liver fibrosis. Literature databases were searched up to 10/2010. The authors of the original publication were contacted, and the original patient data were requested. A meta-analysis was performed using a random effect meta-analytic method for diagnostic tests. In addition, available data comparing ARFI with FibroScan with the DeLong test were evaluated. Literature search yielded nine full-paper publications evaluating ARFI while using liver biopsy as reference method. Original patient data were available from eight studies including 518 patients. The mean diagnostic accuracy of ARFI expressed as areas under ROC curves (AUROC) was 0.87 for the diagnosis of significant fibrosis (F ≥ 2), 0.91 for the diagnosis of severe fibrosis (F ≥ 3), and 0.93 for the diagnosis of cirrhosis. ARFI can be performed with good diagnostic accuracy for the noninvasive staging of liver fibrosis., (© 2011 Blackwell Publishing Ltd.)

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (Pin1) is a unique enzyme that associates with the pSer/Thr-Pro motif and catalyzes cis-trans isomerization. We identified Pin1 in the immunoprecipitates of overexpressed IRS-1 with myc and FLAG tags in mouse livers and confirmed the association between IRS-1 and Pin1 by not only overexpression experiments but also endogenously in the mouse liver. The analysis using deletion- and point-mutated Pin1 and IRS-1 constructs revealed the WW domain located in the N terminus of Pin1 and Ser-434 in the SAIN (Shc and IRS-1 NPXY binding) domain of IRS-1 to be involved in their association. Subsequently, we investigated the role of Pin1 in IRS-1 mediation of insulin signaling. The overexpression of Pin1 in HepG2 cells markedly enhanced insulin-induced IRS-1 phosphorylation and its downstream events: phosphatidylinositol 3-kinase binding with IRS-1 and Akt phosphorylation. In contrast, the treatment of HepG2 cells with Pin1 siRNA or the Pin1 inhibitor Juglone suppressed these events. In good agreement with these in vitro data, Pin1 knock-out mice exhibited impaired insulin signaling with glucose intolerance, whereas adenoviral gene transfer of Pin1 into the ob/ob mouse liver mostly normalized insulin signaling and restored glucose tolerance. In addition, it was also demonstrated that Pin1 plays a critical role in adipose differentiation, making Pin1 knock-out mice resistant to diet-induced obesity. Importantly, Pin1 expression was shown to be up-regulated in accordance with nutrient conditions such as food intake or a high-fat diet. Taken together, these observations indicate that Pin1 binds to IRS-1 and thereby markedly enhances insulin action, essential for adipogenesis.

Unlabelled: The specific mechanisms of nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) pathogenesis remain unknown. In the present study we investigated the differences between NAFL and NASH in terms of liver lipid metabolites and serum lipoprotein. In all, 104 Japanese subjects (50 men and 54 postmenopausal women) with histologically verified NAFL disease (NAFLD) (51 with NAFL, 53 with NASH) were evaluated; all diagnoses were based on liver biopsy findings and the proposed diagnostic criteria. To investigate the differences between NAFL and NASH in humans, we carefully examined (1) lipid inflow in the liver, (2) lipid outflow from the liver, (3) very-low-density lipoprotein (VLDL) synthesis in the liver, (4) triglyceride (TG) metabolites in the liver, and (5) lipid changes and oxidative DNA damage. Most of the hepatic lipid metabolite profiles were similar in the NAFL and NASH groups. However, VLDL synthesis and lipid outflow from the liver were impaired, and surplus TGs might have been produced as a result of lipid oxidation and oxidative DNA damage in the NASH group., Conclusion: A growing body of literature suggests that a deterioration in fatty acid oxidation and VLDL secretion from the liver, caused by the impediment of VLDL synthesis, might induce serious lipid oxidation and DNA oxidative damage, impacting the degree of liver injury and thereby contributing to the progression of NASH. Therefore, dysfunctional VLDL synthesis and release may be a key factor in progression to NASH.

Background: Liver fibrosis is the main predictor of the progression of nonalcoholic fatty liver disease. Transient elastography (FibroScan), which measures liver stiffness, is a novel, noninvasive method to assess liver fibrosis., Aim: We investigated the usefulness of liver stiffness measurement in the evaluation of liver fibrosis in nonalcoholic fatty liver disease patients., Study Population: A total of 97 nonalcoholic fatty liver disease patients., Methods: Transient elastography was performed for liver stiffness measurement in 97 nonalcoholic fatty liver disease patients. And the relationship between histological parameters and liver stiffness measurement was studied by multivariate analysis. Moreover, we investigated the relationship between liver stiffness measurement and the serum levels of hyaluronic acid and type IV collagen 7s domain., Results: The liver stiffness was well correlated with the stage of liver fibrosis (Kruskal-Wallis test p < 0.0001). The areas under the receiver-operating characteristic curves were 0.927 for > or = F1, 0.865 for > or = F2, 0.904 for > or = F3, 0.991 for > or = F4. Only fibrosis stage was correlated significantly with liver stiffness measurement by multiple regression analysis. Liver stiffness was also strongly correlated with the serum levels of type IV collagen 7s domain (r = 0.525, p < 0.0001) and hyaluronic acid (r = 0.457, p < 0.0001)., Conclusions: Our results show a significant correlation between liver stiffness measurement and fibrosis stage in nonalcoholic fatty liver disease patients, as confirmed by the results of liver biopsy, which remains the gold standard for evaluation of the severity of liver fibrosis in patients with nonalcoholic steatohepatitis.

The differential diagnosis between intracystic hemorrhage and cystadenocarcinoma of the liver is often difficult even with the use of various imaging modalities. A 73-year-old woman was admitted to our hospital with the complaint of right upper quadrant pain. Ultrasonography (US) demonstrated a heterogeneous echogenic cyst measuring 11 cm multiply 8 cm in size in S2 of the liver, indicated intracystic hemorrhage of simple liver cyst or cystadenocarcinoma, but the differential diagnosis was considerably difficult. Levovist (Schering, Berlin, Germany) US revealed no enhancement of the intracystic structures, suggesting a clot in the case of intracystic hemorrhage. An operation was performed and the resected lesion showed a solitary benign liver cyst, measuring 5.5 cm multiply 4.7 cm multiply 8.5 cm containing a large blood clot. The patient had an uneventful recovery after the surgery. Levovist US may play an important role in discrimination between intracystic hemorrhage of simple hepatic cysts and cystadenocarcinoma of the liver.

Aim: To investigate the efficacy of angiotensin II receptor antagonist on hepatic stellate cells (HSCs) activation in the patients with non-alcoholic steatohepatitis (NASH)., Methods: Seven patients with NASH were prescribed losartan, a selective angiotensin II type 1 receptor antagonist (50 mg/d) for 48 wk. Liver biopsies were performed both at the entry and end of the study in all patients. Quiescent and activated HSCs were identified by double immunostaining using anti-p75 and -smooth muscle actin antibodies, and the number of each phenotype was counted. Similarly, the liver specimens obtained from the eight patients with non-alcoholic fatty liver (NAFL) were also examined as controls., Results: In NASH hepatic tissues, activated HSCs were dominantly distributed as compared with those in NAFL. The 48-wk losartan treatment induced a remarkable decrease in activated HSCs and a mild increase in quiescent phenotypes., Conclusion: Our data suggest the crucial involvement of HSCs in anti-fibrotic effect of angiotensin II receptor antagonist on patients with NASH.

Central neuropeptides play roles in many physiologic regulations through the autonomic nervous system. We have demonstrated that central thyrotropin-releasing hormone (TRH), one of neuropeptides, induces a stimulation of hepatic proliferation through vagal-cholinergic pathways. Since cAMP is known to play an important role in the hepatic proliferation, effect of central TRH on hepatic cAMP was investigated. Rats were intracisternally injected with either a TRH analog, RX-77368 (1-100 ng), or saline. The liver was removed 2-72 h after the TRH analog and hepatic cAMP content was determined by radioimmunoassay. In some experiments, pretreatment with hepatic vagotomy, atropine methyl nitrate, or 6-hydroxydopamine (6-OHDA) was performed. Hepatic cAMP was dose-dependently increased by intracisternal TRH analog (5-100 ng) with a peak response occurring 12 h postinjection. The central TRH-induced increase in hepatic cAMP was abolished by vagotomy, atropine and indomethacin, but not by 6-OHDA. Intravenous injection of the TRH analog (10 ng) did not affect hepatic cAMP. These results demonstrate that TRH acts in the brain to increase hepatic cAMP through vagal-cholinergic and prostaglandin-dependent pathways, suggesting that central TRH modulates hepatic functions through cAMP-mediated signaling pathways.

Responses of hepatic glucose output (HGO) to electro-acupuncture (EA) stimulation of the hindlimb were investigated in anaesthetized rats, focusing on involvement of the somatic afferent and autonomic efferent nerves. HGO was measured with a microdialysis probe implanted into the left lateral lobe of the liver. Stainless steel needles with a diameter of 0.25 mm were inserted into the right tibialis anterior muscle and connected to an electrical stimulator. The EA stimulation was delivered for 10 min at 10 mA, 20 Hz. Atropine was injected in order to block the action of the parasympathetic nerves, whereas phentolamine and propranolol were injected in order to block the action of the sympathetic nerves. Furthermore, adrenal sympathetic nerves were crushed bilaterally to block the reflex secretion of adrenal medullary hormones. The EA stimulation significantly increased HGO for 20 min after the onset of stimulation. The increases of HGO were abolished by severing the femoral and sciatic nerves, demonstrating that the responses are elicited via activation of somatic afferent nerves. Furthermore, the increases were diminished after severance of the adrenal sympathetic nerves, which regulate catecholamine secretion from the adrenal medulla. The increases were totally abolished after pretreatment with phentolamine, an alpha-adrenergic blocker, and propranolol, a beta-adrenergic blocker. On the other hand, the increases of HGO in response to the EA stimulation were augmented after pretreatment with atropine, a muscarinic cholinergic blocker. The present results demonstrate that EA stimulation to a hindlimb can reflexly increase HGO via activation of somatic afferents and, thereby, sympathetic efferents, including sympathetic efferents to the adrenal medulla. The present results further show that the increases of HGO in responses to EA stimulation are simultaneously reflexly inhibited via the parasympathetic nerves.

The aim of the present study was to investigate how hepatic blood flow (HBF) changes in response to mechanical stimulation of different areas of the skin in anaesthetised rats, by focusing on involvement of the hepatic sympathetic nerves in and contribution of systemic circulatory changes to the HBF responses. HBF was measured at the surface of the left lateral lobe using the laser Doppler flowmetry. Both innocuous and noxious mechanical stimuli were applied to skin areas of the abdomen and hindlimb. Innocuous mechanical stimulation (brushing) of the abdomen and hindlimb did not significantly change HBF, while noxious mechanical stimulation (pinching) of the abdomen and hindlimb did. The responses to pinching were dependent on the sites stimulated. Pinching of the abdomen decreased, while pinching of the hindlimb increased the HBF. The decrease of HBF in response to abdominal pinching remained after the spinal cord was transected at T1-2 level, but the response was diminished after hepatic sympathetic nerves were severed. On the other hand, the increase of HBF in response to hindlimb pinching was dependent on the increase in blood pressure, and was not influenced by the severance of hepatic sympathetic nerves, and the responses to hindlimb pinching were almost absent after the spinal cord was transected. Based on these results, we suggest that noxious mechanical stimulation of the skin produces changes of HBF, either as a reflex response via activation of the hepatic sympathetic nerves or as a passive response to systemic circulatory changes, depending on the sites stimulated.

The aim of the present study was to elucidate the influence of the hepatic sympathetic and parasympathetic (vagal) nerves on the hepatic blood flow (HBF), both tonically and when stimulated, using urethane-anesthetized rats as an in vivo experimental model. HBF was measured at the surface of the lateral left lobe of the liver using laser Doppler flowmetry and the hydrogen gas clearance method. Denervation of the hepatic sympathetic nerves had no influence on the HBF, while electrical stimulation of the hepatic sympathetic nerves caused the HBF to decrease in a frequency-dependent manner. This decrease was shown to occur via alpha-adrenergic receptors. In contrast, neither denervation nor electrical stimulation of the hepatic vagal nerves elicited significant changes in the HBF. These results demonstrate that the sympathetic and vagal hepatic nerves have little or no tonic influence on the HBF of rats under urethane anesthesia, whereas the HBF decreases in response to activation of the hepatic sympathetic nerves.

Background/aims: Macrophage inflammatory protein-2 (MIP-2), one of the CXC chemokines, is involved in the recruitment of neutrophils in several tissue injuries. In this study, we investigated the role of MIP-2 in concanavalin A (Con A)-induced liver injury in mice., Methods: Liver injury was induced by intravenous injection of Con A (15 mg/kg) and plasma alanine aminotransferase (ALT), MIP-2 levels were determined and histological assessment of the liver was performed. Anti-mouse MIP-2 antibody was intravenously administered 30 min before Con A injection., Results: The plasma ALT level significantly elevated and reached a maximum at 8 h after Con A injection. The plasma MIP-2 level was also elevated and reached a peak value at 2 h after Con A injection. The elevated ALT level by Con A injection was significantly inhibited by the MIP-2 antibody. The elevated plasma MIP-2 level after Con A injection was significantly reduced by the tumor necrosis factor alpha (TNF-alpha) antibody, and MIP-2 was induced in plasma after recombinant TNF-alpha injection. Hepatic necrosis and infiltration of neutrophils were observed after Con A injection, and these histological changes were attenuated by the MIP-2 antibody., Conclusions: These findings suggest that Con A induces TNF-alpha release, and this TNF-alpha stimulates MIP-2 induction, at least partially contributing to the liver injury mediated through the recruitment of neutrophils.

In addition to classical neurotransmitters, such as acetylcholine and noradrenaline, neuropeptides have been recognized as new neurotransmitters and neuromodulators. Neuropeptides are widely distributed in the central nervous system as well as in peripheral nerves, and act as neurotransmitters to regulate various physiological functions. The digestive organs are no exception, and several neuropeptides in the central nervous system are shown to act in specific brain sites and control gastrointestinal functions, such as gastric acid secretion, and gastrointestinal motility, through the autonomic nervous system. Recently, a relationship between central neuropeptides and hepatic function through the autonomic nervous system has been revealed in animal models. Thyrotropin-releasing hormone acts in the medulla, in particular in the left dorsal vagal complex, to induce stimulation of hepatic blood flow and hepatic proliferation, and protect against experimental liver injury through vagal and cholinergic pathways. Corticotropin-releasing factor injected intracisternally elicits inhibition of the hepatic blood flow and exacerbates experimental liver injury through sympathetic and noradrenergic pathways. Neuropeptide Y acts in the left dorsal vagal complex, in particular in regard to the Y1 receptor subtype, to stimulate bile secretion. Other neuropeptides such as beta-endorphin and bombesin in the brain modulate hepatic proliferation and bile secretion. Through the use of neuropeptides, new knowledge of the central and peripheral mechanisms underlying brain regulation of hepatic function will be revealed. Further studies in regard to the physiological relevance of the central action of neuropeptides on specific brain sites should be performed to unravel the underlying pathways that mediate brain-liver interaction.

The involvement of capsaicin-sensitive afferent neurons and calcitonin gene-related peptide (CGRP) in the central thyrotropin-releasing hormone (TRH)-induced hepatic hyperemia was investigated in urethane anesthetized rats. Both systemic capsaicin pretreatment and intravenous administration of CGRP receptor antagonist, human CGRP-(8-37), completely abolished the stimulatory effect of hepatic blood flow induced by intracisternal injection of TRH analog (RX-77368; p-Glu-His-(3,3'-dimethyl)-Pro-NH2, 100 ng), assessed by the hydrogen gas clearance method. These data demonstrate the involvement of capsaicin-sensitive afferent neurons and CGRP in the central TRH-induced stimulation of hepatic blood flow.

Nitric oxide (NO) is produced by the liver during lipopolysaccharide (LPS)-induced endotoxemia. The aim of this study was to examine whether NO, which is produced in the liver, is released from the liver surface to the intraabdominal cavity during endotoxemia. NO was quantitatively determined by chemiluminescence and a newly developed gas purge technique was used to directly measure NO released from the liver surface and the intraabdominal cavity of rats before and after LPS (0.1 mg/kg, intraperitoneally) or saline administration. The expression of inducible NO synthase (iNOS) mRNA in the liver was detected by Northern blot analysis. NO levels from both the liver surface and in the intraabdominal cavity were elevated at 2 h after LPS injection and peaked at 10 h and both the time course of NO level were well correlated with each other. Both NO levels were below the detectable range before LPS and after saline administration. Inducible NOS mRNA in the liver exhibited a sharp increase to a maximum level at 4 h after LPS injection. The present study indicates that the hepatic NO, which might have been produced by iNOS in the liver, is released from the liver surface to the intraabdominal cavity during endotoxemia.

Central neuropeptides play a role as physiological regulators in the autonomic nervous system. One of these neuropeptides, thyrotropin-releasing hormone (TRH), is distributed throughout the central nervous system (CNS) and acts as a neurotransmitter to regulate gastric functions through the vagus nerve. However, the autonomic nervous system is also involved in hepatic regeneration, but the effect of TRH is unknown. Therefore, the CNS's effect of TRH on hepatic DNA synthesis was studied in rats. Hepatic DNA synthesis was assessed by [Methyl-3H]thymidine incorporation 6, 12, 24, 48, and 72 hours after intracisternal injection of the TRH analog, RX 77368 (1, 5, 10, and 100 ng), and by 5-bromo-2'-deoxyuridine (BrdU) labeling of the liver section. Hepatic DNA synthesis was stimulated by intracisternal TRH analog (10 ng), with a peak response at 24 hours after peptide injection, and returned to baseline by 72 hours. This stimulatory effect by central TRH analog on hepatic DNA synthesis was dose-related, ranging from 1 ng to 10 ng (dpm/microg DNA at 24 hours [mean +/- SE]: saline, 95 +/- 6; 1 ng, 114 +/- 14; 5 ng, 318 +/- 57; 10 ng, 693 +/- 78; 100 ng, 710 +/- 135). Hepatocytes were randomly labeled by BrdU 24 hours after intracisternal TRH analog (10 ng). Intravenous TRH analog (10 ng) did not influence hepatic DNA synthesis. The stimulatory effect of TRH analog was blocked by hepatic branch vagotomy and atropine, but not by hepatic sympathectomy, 6-hydroxydopamine, insulin antibody, or hypophysectomy. These results indicate that TRH acts in the CNS to stimulate hepatic DNA synthesis through vagal and cholinergic mechanisms, and that TRH may be the chemical messenger involved in brain regulation of hepatic proliferation.