Adoptive Cell Transfer of Regulatory T Cells Exacerbates Hepatic Steatosis in High-Fat High-Fructose Diet-Fed Mice.

Background and Aims: Non-alcoholic steatohepatitis (NASH) is a multisystem condition, involving the liver, adipose tissue, and immune system. Regulatory T (Treg) cells are a subset of T cells that exert an immune-controlling effect. Previously, a reduction of Treg cells in the visceral adipose tissue (VAT) was shown to be associated with a more severe degree of liver disease. We aimed to correct this immune disruption through adoptive cell transfer (ACT) of Treg cells. Methods: Male 8-week-old C57BL/6J mice were fed a high-fat high-fructose diet (HFHFD) for 20 weeks. Treg cells were isolated from the spleens of healthy 8 to 10-week-old C57BL/6J mice and were adoptively transferred to HFHFD-fed mice. PBS-injected mice served as controls. Plasma ALT and lipid levels were determined. Liver and adipose tissue were assessed histologically. Cytotoxic T (Tc), Treg, T helper (Th) 1 and Th17 cells were characterized in VAT, liver, subcutaneous adipose tissue (SAT), blood, and spleen via flow cytometry. Gene expression analysis was performed in SAT and VAT of mice fed either the HFHFD or a control diet for 10-32 weeks. Results: ACT increased Treg cells in SAT, but not in any of the other tissues. Moreover, the ACT induced a decrease in Th1 cells in SAT, liver, blood, and spleen. Higher plasma ALT levels and a higher degree of steatosis were observed in ACT mice, whereas the other HFHFD-induced metabolic and histologic disruptions were unaffected. Expression analysis of genes related to Treg-cell proliferation revealed a HFHFD-induced decrease in all investigated genes in the SAT, while in the VAT the expression of these genes was largely unaffected, except for a decrease in Pparg. Conclusion: ACT of Treg cells in HFHFD-fed mice exacerbated hepatic steatosis, which was possibly related to the increase of Treg cells in the SAT and/or the general decrease in Th1 cells. Moreover, the HFHFD-induced decrease in Pparg expression appeared critical in the decrease of Treg cells at the level of the VAT and the inability to replenish the amount of Treg cells by the ACT, while the mechanism of Treg cell accumulation at the level of the SAT remained unclear.

Diet Reversal and Immune Modulation Show Key Role for Liver and Adipose Tissue T Cells in Murine Nonalcoholic Steatohepatitis.

BACKGROUND & AIMS: Nonalcoholic steatohepatitis (NASH) is a multisystem condition, implicating liver and adipose tissue. Although the general involvement of the innate and adaptive immune system has been established, we aimed to define the exact role of the functionally diverse T-cell subsets in NASH pathogenesis through diet reversal and immunologic modulation. METHODS: Multiple experimental set-ups were used in 8-week-old C57BL/6J mice, including prolonged high-fat high-fructose diet (HFHFD) feeding, diet reversal from HFHFD to control diet, and administration of anti-CD8a and anti-interleukin 17A antibodies. Plasma alanine aminotransferase, glucose, and lipid levels were determined. Liver and adipose tissue were assessed histologically. Cytotoxic T (Tc), regulatory T, T helper (Th) 1, and Th17 cells were characterized in liver and visceral adipose tissue (VAT) via flow cytometry and RNA analysis. RESULTS: HFHFD feeding induced the metabolic syndrome and NASH, which coincided with an increase in hepatic Th17, VAT Tc, and VAT Th17 cells, and a decrease in VAT regulatory T cells. Although diet reversal induced a phenotypical metabolic and hepatic normalization, the observed T-cell disruptions persisted. Treatment with anti-CD8a antibodies decreased Tc cell numbers in all investigated tissues and induced a biochemical and histologic attenuation of the HFHFD-induced NASH. Conversely, anti-interleukin 17A antibodies decreased hepatic inflammation without affecting other features of NASH or the metabolic syndrome. CONCLUSIONS: HFHFD feeding induces important immune disruptions in multiple hepatic and VAT T-cell subsets, refractory to diet reversal. In particular, VAT Tc cells are critically involved in NASH pathogenesis, linking adipose tissue inflammation to liver disease.

Severe steatosis induces portal hypertension by systemic arterial hyporeactivity and hepatic vasoconstrictor hyperreactivity in rats.

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease. The presence of portal hypertension has been demonstrated in NAFLD prior to development of inflammation or fibrosis, and is a result of extrahepatic and intrahepatic factors, principally driven by vascular dysfunction. An increased intrahepatic vascular resistance potentially contributes to progression of NAFLD via intralobular hypoxia. However, the exact mechanisms underlying vascular dysfunction in NAFLD remain unknown. This study investigates systemic hemodynamics and both aortic and intrahepatic vascular reactivity in a rat model of severe steatosis. Wistar rats were fed a methionine-choline-deficient diet, inducing steatosis, or control diet for 4 weeks. In vivo hemodynamic measurements, aortic contractility studies, and in situ liver perfusion experiments were performed. The mean arterial blood pressure was lower and portal blood pressure was higher in steatosis compared to controls. The maximal contraction force in aortic rings from steatotic rats was markedly reduced compared to controls. While blockade of nitric oxide (NO) production did not reveal any differences, cyclooxygenase (COX) blockade reduced aortic reactivity in both controls and steatosis, whereas effects were more pronounced in controls. Effects could be attributed to COX-2 iso-enzyme activity. In in situ liver perfusion experiments, exogenous NO donation or endogenous NO stimulation reduced the transhepatic pressure gradient (THPG), whereas NO synthase blockade increased the THPG only in steatosis, but not in controls. Alpha-1-adrenergic stimulation and endothelin-1 induced a significantly more pronounced increase in THPG in steatosis compared to controls. Our results demonstrate that severe steatosis, without inflammation or fibrosis, induces portal hypertension and signs of a hyperdynamic circulation, accompanied by extrahepatic arterial hyporeactivity and intrahepatic vascular hyperreactivity. The arterial hyporeactivity seems to be NO-independent, but appears to be mediated by specific COX-2-related mechanisms. Besides, the increased intrahepatic vascular resistance in steatosis appears not to be NO-related but rather to vasoconstrictor hyperreactivity.

Hepatocellular autophagy modulates the unfolded protein response and fasting-induced steatosis in mice.

Autophagy and the unfolded protein response (UPR) are key cellular homeostatic mechanisms and are both involved in liver diseases, including nonalcoholic fatty liver disease (NAFLD). Although increasing but conflicting results link these mechanisms to lipid metabolism, their role and potential cross talk herein have been poorly investigated. Therefore, we assessed the effects of hepatocyte-specific autophagy deficiency on liver parenchyma, the UPR, and lipid metabolism. Adult hepatocellular-specific autophagy-deficient mice (Atg7F/FAlb-Cre+) were compared with their autophagy-competent littermates (Atg7+/+Alb-Cre+). Livers were analyzed by electron microscopy, histology, real-time qPCR, and Western blotting. Atg7F/FAlb-Cre+ mice developed hepatomegaly with significant parenchymal injury, as shown by inflammatory infiltrates, hepatocellular apoptosis, pericellular fibrosis, and a pronounced ductular reaction. Surprisingly, the UPR exhibited a pathway-selective pattern upon autophagy deficiency. The activity of the adaptive activating transcription factor 6 (ATF6) pathway was abolished, whereas the proapoptotic protein kinase RNA-like ER kinase pathway was increased compared with Atg7+/+Alb-Cre+ mice. The inositol-requiring enzyme-1α signal was unaltered. Fasting-induced steatosis was absent in Atg7F/FAlb-Cre+ mice. Remarkably, some isolated islands of fat-containing and autophagy-competent cells were observed in these livers. Hepatocellular autophagy is essential for parenchymal integrity in mice. Moreover, in the case of autophagy deficiency, the three different UPR branches are pathway selectively modulated. Attenuation of the ATF6 pathway might explain the observed impairment of fasting-induced steatosis. Finally, autophagy and lipid droplets are directly linked to each other.

Role of autophagy in the pathophysiology of nonalcoholic fatty liver disease: a controversial issue.

Autophagy is a mechanism involved in cellular homeostasis under basal and stressed conditions delivering cytoplasmic content to the lysosomes for degradation to macronutrients. The potential role of autophagy in disease is increasingly recognised and investigated in the last decade. Nowadays it is commonly accepted that autophagy plays a role in the hepatic lipid metabolism. Hence, dysfunction of autophagy may be an underlying cause of non-alcoholic fatty liver disease. However, controversy of the exact role of autophagy in the lipid metabolism exists: some publications report a lipolytic function of autophagy, whereas others claim a lipogenic function. This review aims to give an update of the present knowledge on autophagy in the hepatic lipid metabolism, hepatic insulin resistance, steatohepatitis and hepatic fibrogenesis.

Fine needle trucut biopsy in focal liver lesions: a reliable and safe method in identifying the malignant nature of liver lesions.

BACKGROUND AND STUDY AIMS: The correct management of a focal liver lesion, suspected of being malignant, requires tissue for histopathological examination. To this purpose an ultrasonically guided fine needle trucut biopsy technique (FNTCB) can be used, to allow obtaining large tissue samples. The aim of the study is to see that FNTCB is a reliable method in identifying the malignant or benign character of a focal liver lesion. PATIENTS AND METHODS: We retrospectively compared the results of 231 FNTCB of focal liver lesions with the final diagnosis. RESULTS: In 191 lesions a final diagnosis was obtained (164 were malignant, 27 were benign). In our series FNTCB has a sensitivity of 86.6% (142/164), a specificity of 100% (27/27) and an overall accuracy of 88.5% (169/191) in identifying malignancy. There was a correct identification in 79.4% (27/34) of primary liver tumours and 88.5% (115/130) of liver metastases. In 52% (60/115) of liver metastases the primary site was accurately suggested by the pathologist. Correct characterization of benign liver lesions was obtained in 63% (17/27) of the cases. The insufficient sample rate was 3.1% (6/191). In one patient with thrombocytopenia an intraabdominal haemorrhage occurred. CONCLUSIONS: FNTCB is a reliable and safe method in identifying the malignant nature of liver lesions. Due to the large tissue sample, insufficient sample rate is low and an accurate histological identification of benign lesions, primary liver malignancies and metastases can be made. In case of metastases it is often possible to determine the site of the primary tumour.

Peginterferon alpha-2b is safe and effective in HBeAg-positive chronic hepatitis B patients with advanced fibrosis.

UNLABELLED: Chronic hepatitis B (CHB) patients with advanced fibrosis are often not considered for treatment with peginterferon (PEG-IFN) because IFN therapy may precipitate immunological flares, potentially inducing hepatic decompensation. We investigated the efficacy and safety of treating hepatitis B e antigen (HBeAg)-positive CHB patients with 52 weeks of PEG-IFN-alpha-2b (100 microg weekly) alone or in combination with lamivudine (100 mg daily). Seventy patients with advanced fibrosis (Ishak fibrosis score 4-6) and 169 patients without advanced fibrosis, all with compensated liver disease, participated in the study. Virologic response, defined as HBeAg seroconversion and hepatitis B virus (HBV) DNA < 10,000 copies/ml at week 78, occurred significantly more often in patients with advanced fibrosis than in those without (25% versus 12%, respectively; P = 0.02). Also patients with cirrhosis (n = 24) exhibited a virologic response more frequently than did patients without cirrhosis (30% versus 14%, respectively; P = 0.02). Improvement in liver fibrosis occurred more frequently in patients with advanced fibrosis (66% versus 26%, P < 0.001). HBV genotype A was more prevalent among patients with advanced fibrosis than among those without (57% versus 24%, P < 0.001). Most adverse events, including serious adverse events, were observed equally as frequently in patients with advanced fibrosis and those without. Fatigue, anorexia, and thrombocytopenia occurred more often in patients with advanced fibrosis than in those without (P < 0.01). Necessary dose reduction or discontinuation of therapy was comparable for both patient groups (P = 0.92 and P = 0.47, respectively). CONCLUSION: PEG-IFN is effective and safe for HBeAg-positive patients with advanced fibrosis. Because PEG-IFN therapy results in a high rate of sustained off-therapy response, patients with advanced fibrosis or cirrhosis but compensated liver disease should not be excluded from PEG-IFN treatment.

Viral hepatitis and hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. The incidence of HCC varies considerably with the geographic area because of differences in the major causative factors. Chronic hepatitis B and C, mostly in the cirrhotic stage, are responsible for the great majority of cases of HCC worldwide. The geographic areas at the highest risk are South-East Asia and sub-Saharan Africa, here hepatitis B is highly endemic and is the main cause of HCC. In areas with an intermediate rate of HCC such as Southern Europe and Japan, hepatitis C is the predominant cause, whereas in low rate areas such as Northern Europe and the USA, HCC is often related to other factors as alcoholic liver disease. There is a rising incidence in HCC in developed countries during the last two decades, due to the increasing rate of hepatitis C infection and improvement of the clinical management of cirrhosis. METHODS: This article reviews the literature on hepatitis and hepatocellular carcinoma. The Medline search was carried out using these key words and articles were selected on epidemiology, risk factors, screening, and prevention of hepatocellular carcinoma. RESULTS: Screening of patients with advanced chronic hepatitis B and C with hepatic ultrasound and determination of serum alfa-fetoprotein may improve the detection of HCC, but further studies are needed whether screening improves clinical outcome. Hepatitis B and C viruses (HBV/HCV) can be implicated in the development of HCC in an indirect way, through induction of chronic inflammation, or directly by means of viral proteins or, in the case of HBV, by creation of mutations by integration into the genome of the hepatocyte. CONCLUSION: The most effective tool to prevent HCC is avoidance of the risk factors such as viral infection. For HBV, a very effective vaccine is available. Preliminary data from Taiwan indicate a protective effect of universal vaccination on the development of HCC. Vaccination against HBV should therefore be a health priority. In patients with chronic hepatitis B or C, interferon-alfa treatment in a noncirrhotic stage is protective for HCC development in responders, probably by prevention of cirrhosis development. When cirrhosis is already present, the protective effect is less clear. For cirrhosis due to hepatitis B, a protective effect was demonstrated in Oriental, but not in European patients. For cirrhosis due to hepatitis C, interferon-alfa treatment showed to be protective in some studies, especially in Japan with a high incidence of HCC in untreated patients. Virological, but also merely biochemical response, seems to be associated with a lower risk of development of HCC. As most studies are not randomized controlled trials, no definitive conclusions on the long-term effects of interferon-alfa in HBV or HCV cirrhosis can be established. Especially in hepatitis C, prospective studies should be performed using the more potent reference treatments for cirrhotics, namely the combination of peginterferon and ribavirin.

Bacillus Calmette-Guérin-induced granulomatous hepatitis in a patient with a superficial bladder carcinoma.

A 71-year-old male patient with a superficial transitional cell carcinoma of the urinary bladder developed high fever and jaundice, accompanied by progressively increasing serum aminotransferase activities, 2 weeks after the fourth local instillation with an attenuated live strain of Mycobacterium bovis [bacillus Calmette-Guérin (BCG)]. A liver biopsy showed non-caseating granulomatous hepatitis. Cultures for mycobacteria were negative. Mycobacterial DNA was not detected in liver tissue using the polymerase chain reaction. Empirical treatment with rifampicin and isoniazid was started, resulting in partial recovery. After 6 months of therapy, however, serum aminotransferase activities were still twice the upper limit of normal. A second liver biopsy still demonstrated several granulomas. Only after addition of prednisolone, liver tests completely normalized. Also histologically the lesions improved dramatically. This suggests that the BCG hepatitis was at least partially caused by a hypersensitivity reaction. Our patient is the first reported case of BCG hepatitis with histological follow-up under therapy.