Large Perpendicular Magnetic Anisotropy Induced by an Intersite Charge Transfer in Strained EuVO2H Films.

Perovskite oxides ABO3 continue to be a major focus in materials science. Of particular interest is the interplay between A and B cations as exemplified by intersite charge transfer (ICT), which causes novel phenomena including negative thermal expansion and metal-insulator transition. However, the ICT properties were achieved and optimized by cationic substitution or ordering. Here we demonstrate an anionic approach to induce ICT using an oxyhydride perovskite, EuVO2H, which has alternating layers of EuH and VO2. A bulk EuVO2H behaves as a ferromagnetic insulator with a relatively high transition temperature (TC) of 10 K. However, the application of external pressure to the EuIIVIIIO2H bulk or compressive strain from the substrate in the thin films induces ICT from the EuIIH layer to the VIIIO2 layer due to the extended empty V dxy orbital. The ICT phenomenon causes the VO2 layer to become conductive, leading to an increase in TC that is dependent on the number of carriers in the dxy orbitals (up to a factor of 4 for 10 nm thin films). In addition, a large perpendicular magnetic anisotropy appears with the ICT for the films of <100 nm, which is unprecedented in materials with orbital-free Eu2+, opening new perspectives for applications. The present results provide opportunities for the acquisition of novel functions by alternating transition metal/rare earth layers with heteroanions.

Preferential increase in the hippocampal synaptic vesicle protein 2A (SV2A) by pentylenetetrazole kindling.

The present study evaluated the expressional levels of synaptic vesicle protein 2A (SV2A) and other secretary machinery proteins (i.e., soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes, Munc18-1, N-ethylmaleimide-sensitive factor (NSF) and soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP)) in a pentylenetetrazole (PTZ) kindling model. Repeated administration of sub-convulsive PTZ (40 mg/kg, i.p.) progressively increased seizure susceptibility in mice and consistently induced clonic seizures in most animals tested at 15 days after the treatment. Western blot analysis revealed that, among the secretary machinery proteins examined, hippocampal SV2A was selectively elevated by PTZ kindling. PTZ kindling-induced SV2A expression appeared region-specific and the SV2A levels in the cerebral cortex or cerebellum were unaltered. In addition, SV2A expression by PTZ kindling was prominent in the hilar region of the dentate gyrus (DG) where GABAergic interneurons are located, but not in other hippocampal regions (e.g., the stratum lucidum of the CA3 and synaptic layers surrounding CA1 or CA3 pyramidal neurons). These findings suggest that PTZ kindling preferentially elevates SV2A expression in the hippocampus probably as a compensatory mechanism to activate the inhibitory neurotransmission.

Hepatitis B virus DNA in liver tissue and risk for hepatocarcinogenesis in patients with hepatitis C virus-related chronic liver disease. A prospective study.

AIMS: To prospectively study whether occult hepatitis B virus (HBV) infection can promote the development of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV)-related chronic liver disease. In addition, to evaluate the difference among HBV DNA-negative patients and patients with high and low HBV copy numbers. METHODS: A total of 167 patients with HCV-related chronic liver disease without HBV surface antigen (HBsAg) were studied. HBV DNA in liver tissue was determined using polymerase chain reaction (PCR). RESULTS: HBV DNA was detected in 9 of 167 patients (5.4%) by single PCR and in 25 patients (15.0%) by nested PCR. HCC developed in 12 of 167 patients (7.2%). Ten of 142 HBV DNA-negative patients (7.0%) and 2 of 9 patients with a high HBV copy number (22.2%) developed HCC, whereas none of 16 patients with a low HBV copy number developed HCC. The incidence rate of HCC in patients with a high HBV copy number was significantly higher than in HBV DNA-negative patients and patients with low HBV copy number. CONCLUSION: A high amount of HBV DNA in liver tissue of HBsAg-negative patients with HCV-related liver disease might be associated with HCC development.

A model for estimating cirrhosis in patients with type 1 autoimmune hepatitis.

UNLABELLED: Longstanding cirrhosis has been recognized as a risk factor for the development of hepatocellular carcinoma in patients with autoimmune hepatitis (AIH). Thus, the accurate determination of cirrhosis is important for prognostication, decisions regarding treatment and monitoring of disease progression. The aim of this study was to identify independent predictors of cirrhosis and to develop a model for estimating cirrhosis in patients with type 1 AIH. METHODS: Using the training sample, consisting of 121 patients with type 1 AIH, we retrospectively examined independent predictors of cirrhosis and constructed a model for estimating cirrhosis. Validation was prospectively performed in the validation sample, consisting of 35 patients. RESULTS: Using a stepwise multiple linear regression analysis, three predictors of serum immunoglobulin A level, ratio of aspartate aminotransferase to alanine aminotransferase, and platelet count were elicited, and a model for estimating cirrhosis was determined as follows: risk score = -0.113 + 0.0006056 x immunoglobulin A (mg/dL) + 0.155 x ratio of aspartate aminotransferase to alanine aminotransferase - 0.007079 x platelet (x10(4)/mm(3)). In the training sample, the sensitivity and specificity were 90% and 83%, respectively, when patients presenting a risk score >/=0.20 were estimated to be cirrhotic. When this model was applied to the validation sample, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 83%, 97%, 83%, 97% and 94%, respectively. CONCLUSION: It is suggested that this model could be useful for the estimation of cirrhosis in patients with type 1 autoimmune hepatitis.

Systemic inflammatory response syndrome strongly affects the prognosis of patients with fulminant hepatitis B.

BACKGROUND: Hepatitis B virus infection is the most frequent cause of fulminant hepatic failure. Recently, systemic inflammatory response syndrome has been reported to be important in patients with fulminant hepatic failure. However, prognostic factors for fulminant hepatitis B have not been fully examined. In this study, we analyzed prognostic factors for fulminant hepatitis B in order to accurately identify patients with fatal outcomes. METHODS: Of 110 consecutive patients with fulminant hepatic failure, 36 (33%) were diagnosed with fulminant hepatitis B. Five of the 36 patients received liver transplants, and we analyzed prognostic factors associated with fatal outcomes in the other 31 patients, who consisted of 15 men and 16 women with a median age of 45 (range, 20-74) years. RESULTS: Eleven patients (35%) survived without liver transplantation, and the remaining 20 (65%) died. Nonsurvivors were older and had a higher prevalence ratio of systemic inflammatory response syndrome than survivors. Treatments were similar between survivors and nonsurvivors. Using a multivariate Cox proportional hazard model, age (>45 years), systemic inflammatory response syndrome, and ratio of total to direct bilirubin (>2.0) were associated with fatal outcomes. In particular, 1-week and overall survival rates of patients with systemic inflammatory response syndrome at the time of diagnosis were 39% and 8%, respectively, while those of patients without systemic inflammatory response syndrome were 94% and 56%, respectively. CONCLUSIONS: Systemic inflammatory response syndrome strongly affects the short-term prognosis of patients with fulminant hepatitis B, and patients with systemic inflammatory response syndrome might need urgent liver transplantation.

Clinical features of Japanese type 1 autoimmune hepatitis patients with zone III necrosis.

AIM: In Caucasians in northern Europe and North America, type 1 autoimmune hepatitis is characterized by susceptibility to human leukocyte antigens DR3 and DR4, and patients with zone III necrosis more frequently have an acute onset of the disease and a lower frequency of cirrhosis than those without. In Japanese patients, however, type 1 autoimmune hepatitis is primarily associated with DR4, and there are almost no DR3-positive patients. Thus, the clinical features of Japanese patients with type 1 autoimmune hepatitis and zone III necrosis may be different from those reported previously for Caucasians. METHODS: We investigated 160 consecutive patients with type 1 autoimmune hepatitis (20 males and 140 females; median age, 55 years; range, 16-79 years). RESULTS: Forty-seven patients (29%) had zone III necrosis, and these patients had lower serum levels of albumin and higher serum levels of total bilirubin, aspartate aminotransferaseand alanine aminotransferase. Histologically, zone III necrosis was found more frequently in patients with acute hepatitis than in those with chronic hepatitis. However, there was no difference in the frequency of cirrhosis between patients with and without zone III necrosis. In addition, normalization of serum alanine aminotransferase levels within six months after the introduction of corticosteroid treatment was slightly more frequent in patients with zone III necrosis (95% vs. 88%). CONCLUSION: In Japanese patients, zone III necrosis may reflect not only acute autoimmune hepatitis, but also acute exacerbation of pre-existing chronic disease. Furthermore, patients with zone III necrosis may respond better to corticosteroid treatment than those without.

A Missense Mutation of the Gene Encoding Synaptic Vesicle Glycoprotein 2A (SV2A) Confers Seizure Susceptibility by Disrupting Amygdalar Synaptic GABA Release.

Synaptic vesicle glycoprotein 2A (SV2A) is specifically expressed in the membranes of synaptic vesicles and modulates action potential-dependent neurotransmitter release. To explore the role of SV2A in the pathogenesis of epileptic disorders, we recently generated a novel rat model (Sv2a(L174Q) rat) carrying a missense mutation of the Sv2a gene and showed that the Sv2a(L174Q) rats were hypersensitive to kindling development (Tokudome et al., 2016). Here, we further conducted behavioral and neurochemical studies to clarify the pathophysiological mechanisms underlying the seizure vulnerability in Sv2a(L174Q) rats. Sv2a(L174Q) rats were highly susceptible to pentylenetetrazole (PTZ)-induced seizures, yielding a significantly higher seizure scores and seizure incidence than the control animals. Brain mapping analysis of Fos expression, a biological marker of neural excitation, revealed that the seizure threshold level of PTZ region-specifically elevated Fos expression in the amygdala in Sv2a(L174Q) rats. In vivo microdialysis study showed that the Sv2a(L174Q) mutation preferentially reduced high K(+) (depolarization)-evoked GABA release, but not glutamate release, in the amygdala. In addition, specific control of GABA release by SV2A was supported by its predominant expression in GABAergic neurons, which were co-stained with antibodies against SV2A and glutamate decarboxylase 1. The present results suggest that dysfunction of SV2A by the missense mutation elevates seizure susceptibility in rats by preferentially disrupting synaptic GABA release in the amygdala, illustrating the crucial role of amygdalar SV2A-GABAergic system in epileptogenesis.

Synaptic vesicle glycoprotein 2A (SV2A) regulates kindling epileptogenesis via GABAergic neurotransmission.

Synaptic vesicle glycoprotein 2A (SV2A) is a prototype synaptic vesicle protein regulating action potential-dependent neurotransmitters release. SV2A also serves as a specific binding site for certain antiepileptics and is implicated in the treatment of epilepsy. Here, to elucidate the role of SV2A in modulating epileptogenesis, we generated a novel rat model (Sv2a(L174Q) rat) carrying a Sv2a-targeted missense mutation (L174Q) and analyzed its susceptibilities to kindling development. Although animals homozygous for the Sv2a(L174Q) mutation exhibited normal appearance and development, they are susceptible to pentylenetetrazole (PTZ) seizures. In addition, development of kindling associated with repeated PTZ treatments or focal stimulation of the amygdala was markedly facilitated by the Sv2a(L174Q) mutation. Neurochemical studies revealed that the Sv2a(L174Q) mutation specifically reduced depolarization-induced GABA, but not glutamate, release in the hippocampus without affecting basal release or the SV2A expression level in GABAergic neurons. In addition, the Sv2a(L174Q) mutation selectively reduced the synaptotagmin1 (Syt1) level among the exocytosis-related proteins examined. The present results demonstrate that dysfunction of SV2A due to the Sv2a(L174Q) mutation impairs the synaptic GABA release by reducing the Syt1 level and facilitates the kindling development, illustrating the crucial role of SV2A-GABA system in modulating kindling epileptogenesis.

Lamivudine treatment in patients with HBV-related hepatocellular carcinoma--using an untreated, matched control cohort.

Lamivudine is widely used to treat patients with hepatitis B. However, the outcomes in patients with hepatocellular carcinoma (HCC) treated with lamivudine have not been established. This study was conducted to evaluate the outcomes of lamivudine treatment for patients with HCC using an untreated, matched control group. Thirty patients with controlled HCC orally received lamivudine. As controls, 40 patients with HCC who were not treated with lamivudine and matched for clinical features were selected. The lamivudine-treated and untreated groups were compared with respect to changes in liver function, HCC recurrence, survival, and cause of death. In the lamivudine-treated group, there was significant improvement in the Child-Pugh score at 24 months after starting treatment, while no improvement was observed in the untreated group. There was no significant difference in the cumulative incidence of HCC recurrence and survival between the groups. However, there was a significant difference in the cumulative incidence of death due to liver failure (P= 0.043). A significant improvement in liver function was achieved by lamivudine treatment, even in patients with HCC. These results suggest that lamivudine treatment for patients with HCC may prevent death due to liver failure. Further prospective randomized studies using a larger number of patients are required.

A scoring system for primary biliary cirrhosis and its application for variant forms of autoimmune liver disease.

BACKGROUND: Although primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) are two independent autoimmune liver diseases, it is sometimes difficult to characterize the variant forms of autoimmune liver disease. A PBC scoring system, in combination with the AIH scoring system may be helpful to characterize such patients. METHODS: A PBC scoring system was introduced that selected 14 categories characteristic of PBC. One hundred and thirty-four patients with PBC, 31 patients with autoimmune cholangitis (AIC), 22 patients with overlap syndrome, and 48 patients with AIH were included in the study. The AIC patients fulfilled the PBC criteria but were negative for anti-mitochondrial antibody and positive for anti-nuclear antibody. Overlap syndrome patients fulfilled both the PBC and AIH criteria. RESULTS: The total scores (means +/- SD) for the PBC, AIC, overlap syndrome, and AIH patients were 23.3 +/- 4.7, 9.3 +/- 4.4, 18.0 +/- 5.9, and 3.6 +/- 3.3, respectively. When definite and probable PBC patients were defined as those with a total score of over 17 and 9-17, respectively, all except for 1 patient could be classified as definite or probable PBC. Four of the 48 AIH patients were classified as probable PBC. PBC scores for the variant autoimmune liver diseases showed a wide deviation. Plotting both PBC and AIH scores in a rectangular coordinate enabled us to locate each patient with variant forms according to the deviation from classical PBC or AIH. CONCLUSIONS: The PBC scoring system might be useful in characterizing the features of variant forms of autoimmune liver disease.

Clinicopathological features of acute-onset autoimmune hepatitis.

The clinicopathological features of nine acute-onset autoimmune hepatitis (AIH) patients were compared with those of 29 classical AIH patients. The clinical features of acute-onset AIH showed significantly higher serum ALT levels, lower serum IgG levels and AIH score than those of classical AIH, although the type of auto-antibodies, age and gender were not different between the two groups. Pathological features showed that the stages of acute-onset AIH varied from stage 1 to stage 4 and were less advanced compared with those of classical AIH. One patient showed submassive hepatic necrosis. Both centrilobular necrosis and interface hepatitis were observed in 7 and 8 of 9, respectively. Three stage 1 patients with centrilobular necrosis and one patient with submassive hepatic necrosis were suggestive of acute presentation, while patients with stages 2 and 4 fibrosis were suggestive of acute exacerbation of chronic disease. An immunohistochemical study demonstrated that CD8 T cells were predominant at both interface hepatitis and centrilobular necrosis, while CD79alpha-positive B lineage cells were predominant at interface hepatitis. These results suggest that acute-onset AIH includes both acute presentation and acute exacerbation of chronic disease and that centrilobular necrosis might be a prevailing pathological feature.

Expressional analysis of inwardly rectifying Kir4.1 channels in Noda epileptic rat (NER).

The inwardly rectifying potassium channel subunit Kir4.1 is expressed in brain astrocytes and involved in spatial K(+) buffering, regulating neural activity. To explore the pathophysiological alterations of Kir4.1 channels in epileptic disorders, we analyzed interictal expressional levels of Kir4.1 in the Noda epileptic rat (NER), a hereditary animal model for generalized tonic-clonic (GTC) seizures. Western blot analysis showed that Kir4.1 expression in NERs was significantly reduced in the occipito-temporal cortical region and thalamus. However, the expression of Kir5.1, another Kir subunit mediating spatial K(+) buffering, remained unaltered in any brain regions examined. Immunohistochemical analysis revealed that Kir4.1 was primarily expressed in glial fibrillary acidic protein (GFAP)-positive astrocytes (somata) and foot processes clustered around neurons proved with anti-neuronal nuclear antigen (NeuN) antibody. In NERs, Kir4.1 expression in astrocytic processes was region-selectively diminished in the amygdaloid nuclei (i.e., medial amygdaloid nucleus and basomedial amygdaloid nucleus) while Kir4.1 expression in astrocytic somata was unchanged. Furthermore, the amygdala regions with reduced Kir4.1 expression showed a marked elevation of Fos protein expression following GTC seizures. The present results suggest that reduced activity of astrocytic Kir4.1 channels in the amygdala is involved in limbic hyperexcitability in NERs.

Kindling-associated SV2A expression in hilar GABAergic interneurons of the mouse dentate gyrus.

Immunohistochemical studies were performed to analyze the expressional changes in hippocampal synaptic vesicle protein 2A (SV2A) following pentylenetetrazole (PTZ) kindling. Repeated treatments of mice with sub-convulsive PTZ (40 mg/kg, i.p.) for 15 days progressively enhanced seizure susceptibility and induced clonic convulsions in most animals examined. Topographical analysis of hippocampal SV2A-immunoreactivity revealed that SV2A was densely expressed in the hilar region of the dentate gyrus, stratum lucidum of the CA3 field and around the periphery of CA3 pyramidal neurons. PTZ kindling region-specifically increased SV2A expression in the dentate hilus without affecting that in the stratum lucidum or the pyramidal cell layer of the CA3 field. Confocal laser microscopic analysis using PTZ-kindled mice illustrated that most SV2A was co-expressed with glutamic acid decarboxylase 67 in the cell bodies and dendrites of hilar interneurons. However, SV2A-immunoreactivity was negligibly observed in the hilar glutamatergic nerve terminals (mossy fibers) probed with the anti-vesicular glutamate transporter 1 antibody. The present study suggests that SV2A specifically regulates hilar GABAergic neurotransmission in the kindled hippocampus probably as a compensatory or prophylactic mechanism against kindling epileptogenesis.

Antiepileptogenic and anticonvulsive actions of levetiracetam in a pentylenetetrazole kindling model.

Levetiracetam (LEV) is a unique antiepileptic drug that preferentially interacts with synaptic vesicle protein 2A (SV2A). To evaluate the antiepileptogenic action of LEV, we studied its effects on the development and acquisition of pentylenetetrazole (PTZ) kindling and compared them to those of sodium valproate (VPA). Anticonvulsive actions of LEV in PTZ-kindled animals were also determined. LEV did not affect PTZ seizures in naïve animals even at high doses (approximately 300 mg/kg, i.p.). However, combined treatment of LEV (30 and 100 mg/kg, i.p.) with PTZ significantly suppressed the development and acquisition of PTZ kindling. In addition, LEV at relatively low doses (3-30 mg/kg, i.p.) inhibited PTZ-evoked seizures in fully kindled animals. In contrast to LEV, VPA at sub-anticonvulsive doses (30 and 100 mg/kg, i.p.) failed to prevent the development of PTZ kindling and its anticonvulsive potency was similar in PTZ-kindled and naïve mice. The present study shows that LEV contrasts VPA by preventing the development of PTZ kindling and inhibiting seizures selectively in kindled animals.

Eosinophilic cholangitis with initial clinical features indistinguishable from IgG4-related cholangitis.

A 66-year-old woman presented with jaundice, elevated liver enzymes, peripheral eosinophilia and increased levels of immunoglobulin (Ig) G4. The image findings of the biliary tree revealed multifocal strictures mimicking primary sclerosing cholangitis. A biopsy specimen of the liver demonstrated an infiltration of inflammatory cells consisting of several eosinophils and IgG4-positive plasma cells. The liver enzymes and eosinophil count were normalized immediately after the administration of an oral steroid. Finally, the patient was diagnosed with eosinophilic cholangitis based on the clinical manifestations, although she had features of both eosinophilic cholangitis and IgG4-related cholangitis. This case indicates that the two entities may show similar manifestations and thus they should be discriminated carefully.

Mortality rate of patients with asymptomatic primary biliary cirrhosis diagnosed at age 55 years or older is similar to that of the general population.

PURPOSE: Recent routine testing for liver function and anti-mitochondrial antibodies has increased the number of newly diagnosed patients with primary biliary cirrhosis (PBC). This study investigated the prognosis of asymptomatic PBC patients, focusing on age difference, to clarify its effect on the prognosis of PBC patients. METHODS: The study was a systematic cohort analysis of 308 consecutive patients diagnosed with asymptomatic PBC. We compared prognosis between the elderly (55 years or older at the time of diagnosis) and the young patients (<55 years). The mortality rate of the patients was also compared with that of an age- and gender-matched general population. RESULTS: The elderly patients showed a higher aspartate aminotransferase-to-platelet ratio, and lower alanine aminotransferase level than the young patients (P < 0.01 and P = 0.03, respectively). The two groups showed similar values for alkaline phosphatase and immunoglobulin M. Death in the young patients was more likely to be due to liver failure (71%), while the elderly were likely to die from other causes before the occurrence of liver failure (88%; P < 0.01), especially from malignancies (35%). The mortality rate of the elderly patients was not different from that of the age- and gender-matched general population (standardized mortality ratio, 1.1; 95% confidence interval, 0.6-1.7), although this rate was significantly higher than that of the young patients (P = 0.044). CONCLUSIONS: PBC often presents as more advanced disease in elderly patients than in the young. However, the mortality rate of the elderly patients is not different from that of an age- and gender-matched general population.

Gene expression profiling in biliary epithelial cells of primary biliary cirrhosis using laser capture microdissection and cDNA microarray.

UNLABELLED: Primary biliary cirrhosis (PBC) is a chronic, cholestatic liver disease characterized by progressive destruction of interlobular bile ducts that leads to biliary cirrhosis. To elucidate the etiology of PBC, the gene expression profile in biliary epithelial cells (BECs) was analyzed. Liver specimens of 5 PBC, 3 chronic hepatitis C (CHC), and 3 normal subjects were obtained. BECs were selectively collected by laser capture microdissection (LCM), RNA were obtained by extraction and amplification with T7 RNA polymerase, and a cDNA microarray analysis was performed. The following genes exhibited increased expression in BEC of PBC, as compared with CHC or normal subjects: human leukocyte antigen DQ alpha 1 (HLA-DQA-1), carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and vascular cell adhesion molecule 1 (VCAM-1). The immunohistochemistry for HLA-DQA-1, CEACAM1, TRAIL, and VCAM-1 confirmed these results. Furthermore, two-way cluster analysis showed that the gene expression profiling in BEC of PBC were categorized into a separate cluster, distinct from CHC or normal subjects. CONCLUSIONS: The gene expression profiling in BEC of PBC differed from those of CHC and normal subjects, and the genes concerning local immune response, such as HLA-DQA-1, CEACAM1, TRAIL, and VCAM-1, exhibited increased expression, indicating that they were involved in the development of bile duct injury.

Persistent normalization of serum alanine aminotransferase levels improves the prognosis of type 1 autoimmune hepatitis.

BACKGROUND/AIMS: Autoimmune hepatitis shows a good response to immunosuppressive treatment, and the prognosis may be determined by the clinical course. The present study was conducted in order to analyze the factors contributing to the outcomes of patients with type 1 autoimmune hepatitis. METHODS: Eighty-four consecutive patients with type 1 autoimmune hepatitis were followed up regularly for a median follow-up period of 70.5 months (16.2-163 months). We analyzed the prognostic factors using time-fixed and time-dependent Cox proportional hazard models. The end point was progression of the disease to decompensated liver cirrhosis. RESULTS: Seventy-seven patients (92%) were treated with prednisolone during the follow-up period, and 11 patients (13%) developed decompensated liver cirrhosis. Using a time-dependent multivariate model, the starting dose of corticosteroid (dose of prednisolone <20 mg/day), relapse within 3 months after the normalization of serum alanine aminotransferase levels with initial treatment, and elevated serum alanine aminotransferase levels during the follow-up period (>40 IU/L), all showed a significant association with progression of the disease. CONCLUSIONS: The prognosis of type 1 autoimmune hepatitis on adequate immunosuppressive treatment improves when the serum alanine aminotransferase level persists at < or = 40 IU/L. Factors existing prior to medical treatment may not affect the prognosis.

A crucial role of hepatocyte nuclear factor-4 expression in the differentiation of human ductular hepatocytes.

Ductular structures are suggested to be bipotential progenitor cells that may differentiate into hepatocytes or biliary epithelial cells (BEC). To better understand the differentiation process, we studied the expression of hepatocyte nuclear factor (HNF) in ductular structures. Matured hepatocytes in normal liver expressed HNF-1, HNF-4alpha, HNF-3beta, and C/EBPalpha in the nucleus. Normal BEC expressed HNF-1 but did not express HNF-4alpha, suggesting an important role of HNF-4alpha in maintaining the phenotype of matured hepatocytes. Ductular structures were classified into ductular cells and ductular hepatocytes. Ductular cells showed glandular or bile duct-like appearance and strongly expressed cytokeratin-7. Ductular hepatocytes showed features between BEC and hepatocytes and heterogeneously expressed cytokeratin-7. Both ductular cells and ductular hepatocytes expressed HNF-4alpha, but the nuclear localization of HNF-4alpha was more prominent in ductular hepatocytes. The expression of HNF-4alpha mRNA in ductular hepatocytes was demonstrated at the single cell level by laser capture microdissection. Regenerative hepatocytes strongly expressed all HNFs in the nucleus, whereas residual hepatocytes in massive necrosis showed low or cytoplasmic expression. These results suggest that HNF-4alpha plays an important role in the differentiation and maintenance of the matured hepatocyte phenotype and that nuclear localization of HNFs is implicated in the accomplishment of their function.