Acyl-CoA:cholesterol acyltransferase 1 mediates liver fibrosis by regulating free cholesterol accumulation in hepatic stellate cells.

BACKGROUND & AIMS: Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes the conversion of free cholesterol (FC) to cholesterol ester, which prevents excess accumulation of FC. We recently found that FC accumulation in hepatic stellate cells (HSCs) plays a role in progression of liver fibrosis, but the effect of ACAT1 on liver fibrosis has not been clarified. In this study, we aimed to define the role of ACAT1 in the pathogenesis of liver fibrosis. METHODS: ACAT1-deficient and wild-type mice, or Toll-like receptor 4 (TLR4)(-/-)ACAT1(+/+) and TLR4(-/-)ACAT1(-/-) mice were subjected to bile duct ligation (BDL) for 3 weeks or were given carbon tetrachloride (CCl4) for 4 weeks to induce liver fibrosis. RESULTS: ACAT1 was the major isozyme in mice and human primary HSCs, and ACAT2 was the major isozyme in mouse primary hepatocytes and Kupffer cells. ACAT1 deficiency significantly exaggerated liver fibrosis in the mouse models of liver fibrosis, without affecting the degree of hepatocellular injury or liver inflammation, including hepatocyte apoptosis or Kupffer cell activation. ACAT1 deficiency significantly increased FC levels in HSCs, augmenting TLR4 protein and downregulating expression of transforming growth factor-ß (TGFß) pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor), leading to sensitization of HSCs to TGFß activation. Exacerbation of liver fibrosis by ACAT1 deficiency was dependent on FC accumulation-induced enhancement of TLR4 signaling. CONCLUSIONS: ACAT1 deficiency exaggerates liver fibrosis mainly through enhanced FC accumulation in HSCs. Regulation of ACAT1 activities in HSCs could be a target for treatment of liver fibrosis.

Multifocal lesions with pancreatic atrophy in IgG4-related autoimmune pancreatitis: report of a case.

We herein report a case of IgG4-related autoimmune pancreatitis (AIP). A 72-year-old male with jaundice visited our hospital complaining of epigastralgia. A blood chemistry analysis revealed elevated serum levels of total bilirubin and DUPAN-II. Computed tomography (CT) revealed irregularly shaped pancreatic masses with a stricture of the main pancreatic duct (MPD) in the head and tail that were interposed by marked atrophy with MPD dilation in the body. F-18 fluorodeoxyglucose (FDG)-positron emission tomography/CT revealed abnormally intense FDG uptake only at the masses. During surgery, another small tumor was also found in the atrophied body; therefore, a total pancreatectomy was performed under the diagnosis of multiple pancreatic cancers. The histological analysis revealed fibrosis with dense and diffuse infiltrations of lymphocytes and IgG4-positive plasma cells. The pancreatic parenchyma of the body was firmly replaced by fibrosis. AIP can lead to the formation of multiple pancreatic lesions, and thus the correct diagnosis is occasionally difficult to establish in atypical cases.

Glucocorticoid receptor-dependent immunomodulatory effect of ursodeoxycholic acid on liver lymphocytes in mice.

Although ursodeoxycholic acid (UDCA) has long been used for patients with chronic cholestatic liver diseases, particularly primary biliary cirrhosis, it may modulate the host immune response. This study investigated the effect of UDCA feeding on experimental hepatitis, endotoxin shock, and bacterial infection in mice. C57BL/6 mice were fed a diet supplemented with or without 0.3% (wt/vol) UDCA for 4 wk. UDCA improved hepatocyte injury and survival in concanavalin-A (Con-A)-induced hepatitis by suppressing IFN-γ production by liver mononuclear cells (MNC), especially NK and NKT cells. UDCA also increased survival after lipopolysaccharide (LPS)-challenge; however, it increased mortality of mice following Escherichia coli infection due to the worsening of infection. UDCA-fed mice showed suppressed serum IL-18 levels and production of IL-18 from liver Kupffer cells, which together with IL-12 potently induce IFN-γ production. However, unlike normal mice, exogenous IL-18 pretreatment did not increase the serum IFN-γ levels after E. coli, LPS, or Con-A challenge in the UDCA-fed mice. Interestingly, however, glucocorticoid receptor (GR) expression was significantly upregulated in the liver MNC of the UDCA-fed mice but not in their whole liver tissue homogenates. Silencing GR in the liver MNC abrogated the suppressive effect of UDCA on LPS- or Con-A-induced IFN-γ production. Furthermore, RU486, a GR antagonist, restored the serum IFN-γ level in UDCA-fed mice after E. coli, LPS, or Con-A challenge. Taken together, these results suggest that IFN-γ-reducing immunomodulatory property of UDCA is mediated by elevated GR in the liver lymphocytes in an IL-12/18-independent manner.

p53/p66Shc-mediated signaling contributes to the progression of non-alcoholic steatohepatitis in humans and mice.

BACKGROUND & AIMS: The tumor suppressor p53 is a primary sensor of stressful stimuli, controlling a number of biologic processes. The aim of our study was to examine the roles of p53 in non-alcoholic steatohepatitis (NASH). METHODS: Male wild type and p53-deficient mice were fed a methionine- and choline-deficient diet for 8 weeks to induce nutritional steatohepatitis. mRNA expression profiles in normal liver samples and liver samples from patients with non-alcoholic liver disease (NAFLD) were also evaluated. RESULTS: Hepatic p53 and p66Shc signaling was enhanced in the mouse NASH model. p53 deficiency suppressed the enhanced p66Shc signaling, decreased hepatic lipid peroxidation and the number of apoptotic hepatocytes, and ameliorated progression of nutritional steatohepatitis. In primary cultured hepatocytes, transforming growth factor (TGF)-ß treatment increased p53 and p66Shc signaling, leading to exaggerated reactive oxygen species (ROS) accumulation and apoptosis. Deficient p53 signaling inhibited TGF-ß-induced p66Shc signaling, ROS accumulation, and hepatocyte apoptosis. Furthermore, expression levels of p53, p21, and p66Shc were significantly elevated in human NAFLD liver samples, compared with results obtained with normal liver samples. Among NAFLD patients, those with NASH had significantly higher hepatic expression levels of p53, p21, and p66Shc compared with the group with simple steatosis. A significant correlation between expression levels of p53 and p66Shc was observed. CONCLUSIONS: p53 in hepatocytes regulates steatohepatitis progression by controlling p66Shc signaling, ROS levels, and apoptosis, all of which may be regulated by TGF-ß. Moreover, p53/p66Shc signaling in the liver appears to be a promising target for the treatment of NASH.

The postoperative serum interleukin-15 concentration correlates with organ dysfunction and the prognosis of septic patients following emergency gastrointestinal surgery.

OBJECTIVE: To clarify the time course of changes in the serum interleukin-15 (IL-15) concentrations in septic patients undergoing emergency surgery for abdominal infection and to investigate whether the serum IL-15 levels correlate with the postoperative clinical course of septic patients. METHODS: Twenty-four septic patients who had intra-abdominal infection and who underwent an emergency operation were enrolled in this study. The serum IL-15 levels were measured before surgery, and on postoperative d 1 (POD1), POD3, and POD5, and the relationship between the serum IL-15 levels and the postoperative clinical course estimated by the Systemic Inflammatory Response Syndrome (SIRS) criteria, Acute Physiology and Chronic Health Evaluation (APACHE-II) score, the parameters of organ function, and the 30-d mortality were evaluated. RESULTS: The time course of changes of the serum IL-15 levels were significantly different between survivors and non-survivors (P < 0.05, by repeated measures analysis of variance [ANOVA]). There was a statistically significant relationship between the serum IL-15 levels on POD1 or POD3 and the duration of SIRS (R = 0.50, P < 0.05, R = 0.65, P < 0.01, respectively). Furthermore, a significant positive correlation was observed between the serum IL-15 levels on POD1 and the creatinine levels on POD1 or POD3 (R = 0.48, P < 0.05, R = 0.50, P < 0.05, respectively), and a significant negative correlation between the serum IL-15 levels on POD1 or POD 3 and the PaO(2)/FiO(2) on POD3 (R = -0.51, P < 0.05, R = -0.69, P < 0.01, respectively). CONCLUSIONS: The measurement of postoperative serum level of IL-15 might be useful for predicting the severity of SIRS and organ dysfunction, especially renal and pulmonary dysfunction.

Importance of maintaining left gastric arterial flow at Appleby operation preserving whole stomach for central pancreatic cancer.

The safety of whole stomach-preserving Appleby operation with resection of the left gastric artery (LGA) for pancreatic cancer cannot be assured. The anatomy of the celiac axis (CA) with special regard to the position of the origin of the LGA was examined. Using 3D images of the vascular architecture reconstructed from volume data of helical CT, the length of the CA and the position of the origin of the LGA from the CA were measured in 53 patients. Among 53 patients, 47 patients (89%) had classical anatomy of the CA branches. The mean length(2 standard deviation) of the CA and the distance from the root of the LGA to the bifurcation of the CA were 25.2mm (-4.9) (range 14.6-36.5) and 10.3mm (+4.5)(range 2.4-21.9), respectively. In 23 (45%) cases, the LGA arose farther than 10mm away from the bifurcation of the CA. Among six patients with anatomical variation of the arteries, two (4%) had the LGA directly arising from the aorta. Conservation of the LGA at modified Appleby operation would give complete cancer removal by en bloc resection of the nerve plexus, without risk of ischemic complications of the stomach and liver.

A case of intraductal papillary mucinous neoplasm of the pancreas rupturing both the stomach and duodenum.

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas may extend to other organs. However, it is rare for a histopathologically benign IPMN to rupture other organs, particularly multiple organs. There has been no report of a benign IPMN rupturing both the stomach and duodenum. OBJECTIVE: We experienced a very rare case and make personal remarks based on bibliographical consideration. DESIGN: Case report. SETTING: National Defense Medical College. PATIENT: A patient with IPMN. INTERVENTION: EGD, ERCP, and pancreatoduodenectomy. CONCLUSIONS: We report a case of benign IPMN of the pancreas extending to two adjacent organs. A 77-year-old male who was diagnosed as having IPMN by CT, MRI, upper GIF, and ERCP underwent pancreatoduodenectomy for a mass of 4.2 cm in diameter. Pathological examinations revealed that the IPMN was composed of adenoma. Intraluminal nodular growth was observed in the duodenal gland tissue, and abnormal growth was observed in the fistula to the stomach. According to a literature review based on PubMed data up until March 2009, it is rare for a benign IPMN to penetrate two adjacent organs.

Poorly differentiated adenocarcinoma with signet-ring cell carcinoma of the extrahepatic bile duct in a 42-year-old Japanese female: a case report.

Poorly differentiated adenocarcinoma without papilla or tubule formation of the extrahepatic bile duct is rare. Here we present a case (a 42-year-old Japanese woman) without either pancreatobiliary maljunction or liver disease. The patient had obstructive jaundice. Imaging studies revealed a bile duct tumor obstructing the common bile duct and invading the surrounding tissues. Pathologic examination revealed a dense periductal growth of poorly differentiated adenocarcinoma containing signet-ring cells, but without papilla or tubule formation in the extrahepatic bile duct. The tumor cells directly invaded the pancreatic parenchyma and the portal vein. In the extrahepatic bile duct, poorly differentiated adenocarcinoma may be established as a distinct clinicopathologic entity if the tumors are characterized by: 1) the absence of papilla or tubule formation, 2) Asian preponderance, 3) occurrence at a younger age than is usual for patients with biliary cancers, and 4) an aggressive mural invasiveness.

The knockdown of endogenous replication factor C4 decreases the growth and enhances the chemosensitivity of hepatocellular carcinoma cells.

AIMS: To identify differentially expressed genes and thereby detect potential molecular targets for future therapies directed against hepatocellular carcinoma (HCC). METHODS: To isolate differentially expressed genes between HCC and adjacent non-cancerous liver tissues, cDNA microarray and quantitative reverse transcriptase polymerase chain reaction analyses were performed. Gene knockdown experiments in HepG2 cells were also performed using small interfering RNAs (siRNAs). Proteins were detected by immunostaining, and cell proliferation was analysed using the MTT/WST-8 assay. Apoptosis and cell cycle analyses were performed using flow cytometry. RESULTS: After an intensive screening for differentially expressed genes in HCC tissues, we isolated 23 upregulated genes in these lesions. Among these, we focused on the replication factor C4 (RFC4) gene. The expression of endogenous RFC4 proteins in HepG2 cells was found to be significantly reduced by RFC4-specific siRNA. This inhibition of RFC4 expression correlated with a decrease in cellular proliferation, increased levels of apoptosis and a sensitizing of the cells to the DNA-damaging chemotherapeutic agents, doxorubicin and camptothecin. CONCLUSION: The replication factor C4 gene may be a novel target for developing cancer therapeutics, which can enhance the antitumour activity of chemotherapeutic agents that induce DNA damage.

Activation of a system A amino acid transporter, ATA1/SLC38A1, in human hepatocellular carcinoma and preneoplastic liver tissues.

The expression of amino acid transporter (AT) mRNAs including A system (ATA1/SNAT1/SLC38A1, ATA2/SNAT2/SLC38A2 and ATA3/SNAT3/SLC38A4), L system (LAT1/SLC7A5 and LAT2/SLC7A8), and y+ (CAT2/SLC7A2) genes, were compared among hepatocellular carcinoma (HCC) and non-cancerous liver cells. Among them the ATA1 mRNA expression was significantly elevated in all HCC cell lines (HepG2, HLF, HuH7 and JHH4) examined compared with normal liver tissue. We further discovered that the expression of ATA1 mRNA was significantly activated in HCC tissues and also elevated in pre-malignant cirrhotic livers from HCC patients, compared with normal livers from non-HCC patients. The ATA1 protein was extensively accumulated in the cytoplasm of pre-malignant liver and most HCCs, while being weak or undetectably low in normal liver tissues. SiRNA-mediated suppression of endogenous ATA1 lowered the viability of HepG2 cells. Thus, the activation of ATA1 confers growth and survival advantages in pre-malignant and malignant liver lesions.

Transformation-associated gene regulation by ATF6alpha during hepatocarcinogenesis.

We have previously reported that the endoplasmic reticulum (ER) stress-regulated transmembrane transcription factor 6 alpha (ATF6alpha) is implicated in the pathogenesis of hepatocellular carcinomas (HCCs). In order to further identify genes that are regulated by ATF6alpha, the global gene expression profiles of the ATF6alpha-transfected and untransfected HCC cell line, HLF, were analyzed. These results were then compared with the differential gene expression patterns of poorly differentiated HCC and control non-tumorous liver tissue. Our findings demonstrate that at least 18 genes are specifically upregulated by ATF6alpha, while another UPR mediator, XBP1 or ER-stress inducer, thapsigargin could partially stimulate or even repress some of them in HCC cells. Moreover, six of these identified genes contain potential ER stress-responsive elements and/or unfolded protein response elements in their 5' regulatory regions.

Carcinoid tumor of the ampulla of Vater. Magnetic resonance imaging findings.

Carcinoid tumors arising from the ampulla of Vater are rare, and their magnetic resonance (MR) imaging findings have not been reported in the literature to date. We report a case of carcinoid tumor of the ampulla of Vater and discuss the characteristic MR imaging findings. The tumor was isointense relative to the muscle on both the T1- and T2-weighted images with heterogeneous enhancement after gadolinium administration. Both the common bile and the pancreatic ducts were dilated on the MR cholangiopancreatography.

Intrahepatic Cholangiocarcinoma With Lymphoepithelioma-like Carcinoma Components Not Associated With Epstein-Barr Virus: Report of a Case.

A carcinoma displaying undifferentiated features with dense lymphoplasmacytic infiltration is defined as lymphoepithelioma-like carcinoma (LELC). Intrahepatic cholangiocarcinoma (ICC) with LELC components is rare, and most LELCs are associated with Epstein-Barr virus (EBV). We report here on a case of ICC with LELC components not associated with EBV. A 65-year-old woman was incidentally found to have a hepatic tumor in the caudate lobe. An extended right hepatectomy with lymphadenectomy was performed. Histologically, the tumor was mainly composed of large undifferentiated epithelial cells with vesicular nuclei, prominent nucleoli, indistinct cell borders, and heavy small lymphocytic infiltration, which are the characteristic features of LELC. Immunohistochemical studies revealed that the tumor cells were positive for cytokeratin 19 but were negative for glypican 3. In situ hybridization using EBV-encoded RNA was negative. Therefore, a diagnosis of ICC with LELC components not associated with EBV was made. Because there is limited information available regarding the prognosis and treatment of ICC with LELC components because of the limited number of reported cases, additional studies will be needed to clarify the clinicopathologic features of this disease.

Right-sided retrocaval approach using guidance via the lesser sac for Spieghel lobe resection.

BACKGROUND: Few reports describe technical problems encountered in resections of the Spieghel lobe of the liver. METHODS: The relationship of the caudate lobe with the inferior vena cava (IVC) was analyzed using computed tomography in 51 patients without hepatobiliary diseases. Using reconstructed 1 mm axial images, the angles of the most dorsal part of the Spieghel lobe (angle A) and the right hepatic lobe (angle B) around the IVC were measured clockwise from the ventral midpoint of the IVC. RESULTS: In 11 (22%) patients, angle A was 180 ° or more, thus the retrocaval part of the Spieghel lobe projected rightward beyond the dorsal midline, but in 1 patient (2%) the right dorsal part of the liver extended leftward beyond the dorsal midline. In 20 (39%) patients, angle A was less than 135 degrees. The Spieghel lobe surrounded the IVC most dorsally at 22% of the distance from the top of the retrohepatic IVC. In 9 patients (18%), the retrocaval process of the Spieghel lobe appeared to be connected to the dorsal part of the right lobe. CONCLUSION: The Spieghel lobe sometimes extends to the right, dorsal aspect of the IVC, such that a right-sided approach facilitates securing the retrohepatic IVC through the lesser sac and allows a safe dissection of the protruding portion of this lobe.

Membranous and cytoplasmic expression of epidermal growth factor receptor in metastatic pancreatic ductal adenocarcinoma.

Recent studies indicate the clinical significance of the cellular localization of epidermal growth factor receptor (EGFR) in a variety of cancer types. Internalization of activated EGFR is reported to be closely associated with patient prognosis. This study investigated the clinical significance of the immunohistochemical localization of EGFR in patients with metastatic pancreatic cancers compared to those with surgically resected pancreatic cancers. Using 44 surgically resected primary pancreatic cancers and 40 primary or meta-static tumors from 20 autopsied patients with far advanced pancreatic cancers, the incidence of membranous and cytoplasmic EGFR overexpression was compared between primary tumors and far advanced tumors by immunohistochemistry using the Dako EGFR pharmDx™ kit, a global standard kit for EGFR assay. In the 44 surgically resected cancers, 13 (30%) exhibited membranous overexpression of EGFR, comprising 1 case (2%) with score 3+ and 12 cases (27%) with score 2+ and 10 (23%) exhibited cytoplasmic overexpression of EGFR. In the 40 tumors at a far advanced stage, the percentage of samples exhibiting positivity for membranous and cytoplasmic EGFR overexpression was 48% (19 of 40) comprising 7 (18%) with score 2+ and 12 (30%) with score 3+ and 33% (13 of 40), respectively. The far advanced tumors tended to show membranous and cytoplasmic EGFR overexpression more frequently than the surgically resected tumors, although the difference was not significant. These findings suggest that membranous and cytoplasmic overexpression of EGFR may be indicative of the potential aggressiveness of pancreatic cancers.

Immunosuppression in the livers of mice with obstructive jaundice participates in their susceptibility to bacterial infection and tumor metastasis.

Although patients with obstructive jaundice are susceptible to bacterial infections and cancers, the mechanisms remain to be elucidated. In the present study, liver mononuclear cells (MNCs) of bile duct-ligated (BDL) mice were immunologically assessed. Liver natural killer T cells were greatly decreased within 24 h after BDL. Upon injection of Escherichia coli (E. coli; 10 colony-forming units) at 7 days after the procedure, all BDL mice had died, but no sham mice died. Consistently, an overgrowth of E. coli was seen in the livers of BDL mice. Although the serum IL-12 and IL-18 levels after E. coli challenge in BDL mice were higher than those in sham mice, the IFN-gamma level was greatly suppressed. However, exogenous IFN-gamma injection significantly increased BDL mouse survival after E. coli challenge. Furthermore, liver MNC of BDL mice exhibited a lower cytotoxic activity against tumors, and BDL mice intravenously injected with liver metastatic EL-4 cells showed markedly increased EL-4 metastases. The total bile acids, as well as the bile acid fractions, increased in the sera and liver. IFN-gamma production by liver MNC from normal mice stimulated with LPS in vitro was inhibited by the addition of bile acids, whereas, conversely, the production of IL-12 and IL-18 increased. In conclusion, liver natural killer T cells were diminished in BDL mice, and the function of liver MNC (IFN-gamma production) was also impaired presumably due to increased bile acids. This may partly explain the increased susceptibility of BDL mice to bacterial infections and tumor metastasis.

Outcomes for patients following hepatic resection of metastatic tumors from gastric cancer.

PURPOSE: Although several studies have reported the efficacy of hepatic resection for the long-term survival of patients with gastric cancer metastases, the optimal treatment remains to be determined. METHODS: Seventeen patients underwent a hepatic resection for gastric cancer metastases at the National Defense Medical College Hospital. We retrospectively analyzed the clinical outcomes of surgical resection and identified factors associated with prognosis for patients who underwent hepatectomy for gastric cancer metastases. RESULTS: In 17 patients, the accumulated 5-year survival rate after hepatic resection was 31.5% and the median survival time was 34 months. Univariate and multivariate analyses showed that gastric tumors less than 6.0 cm and D2 lymphadenectomy were the most important predictors of survival. The five patients who survived more than 5 years after hepatic resection had a D2 lymphadenectomy, modest lymphatic invasion, primary gastric tumors less than 6.0 cm, and a solitary liver metastasis. CONCLUSION: Although recent progress in adjuvant therapy should be the key to a good prognosis, we believe that surgical resection may bring some hope of long-term survival for judiciously selected patients with hepatic metastases from gastric cancer.

Combined hepatocellular carcinoma and cholangiocarcinoma with components of mucinous carcinoma arising in a cirrhotic liver.

A rare autopsy case of combined hepatocellular and cholangiocarcinoma, occurring in a 54-year-old man with liver cirrhosis, is presented. Initial laboratory data included CEA 52.1 ng/mL, DUPAN-2 1600 U/mL, AFP 2 ng/mL, and negativity for hepatitis B surface antigen, hepatitis B early antigen and hepatitis B core antibody. Ultrasonography and CT scan showed a large tumor node in the liver with ringed enhancement, swelling of several para-aortic lymph nodes, and ascites. Clinically, it was not possible to determine whether the hepatic tumor was an intrahepatic cholangiocarcinoma or a metastatic carcinoma. Histologically, the primary lesion was composed solely of hepatocellular carcinoma (HCC) with a trabecular pattern, and the intrahepatic metastases consisted of a variable admixture of HCC and cholangiocarcinoma (CC) with excessive mucin production. Interestingly, the tumor cell cluster showing a trabecular growth pattern produced mucin and had immunohistochemical expression of hepatocyte, cytokeratins 7 and 8. It is concluded that these hepatic tumor cells had both HCC and CC characters.

Mucinous carcinoma of the duodenum associated with hereditary nonpolyposis colorectal cancer: report of a case.

We herein report a rare case of primary mucinous carcinoma of the duodenum associated with hereditary nonpolyposis colorectal cancer (HNPCC). A 50-year-old man known to have HNPCC based on the Amsterdam criteria I was admitted because of the presence of a duodenal tumor. Duodenoscopy revealed an ulcerated tumor in the posterior wall of the second portion of the duodenum and the malignancy was confirmed by a biopsy. He underwent a pylorus-preserving pancreaticoduodenectomy with a regional lymph node dissection. The histological diagnosis was mucinous carcinoma of the duodenum with lymph node metastasis. High-frequency microsatellite instability (MSI-H) was identified in both the colon and a duodenal specimen based on a microsatellite assay. A germline mutation in the hMSH2 gene was also identified. Even though extracolonic malignancies are associated with HNPCC, duodenal cancer is nevertheless very rare, and only two cases have been reported over the past 20 years. The present case is therefore only the third such case and the patient is herein described with a brief review of the literature.