Integrator complex subunit 6 promotes hepatocellular steatosis via ß-catenin-PPARγ axis.

Hepatic adipogenesis has common mechanisms with adipocyte differentiation such as PPARγ involvement and the induction of adipose tissue-specific molecules. A previous report demonstrated that integrator complex subunit 6 (INTS6) is required for adipocyte differentiation. This study aimed to investigate INTS6 expression and its role in hepatic steatosis progression. The expression of INTS6 and PPARγ was examined in the liver of a mouse model of steatohepatitis and in paired liver biopsy samples from 11 patients with severe obesity and histologically proven metabolic dysfunction associated steatohepatitis (MASH) before and one year after bariatric surgery. To induce hepatocellular steatosis in vitro, an immortalized human hepatocyte cell line Hc3716 was treated with free fatty acids. In the steatohepatitis mouse model, we observed hepatic induction of INTS6, PPARγ, and adipocyte-specific genes. In contrast, ß-catenin which negatively regulates PPARγ was reduced. Biopsied human livers demonstrated a strong positive correlation (r2 = 0.8755) between INTS6 and PPARγ mRNA levels. After bariatric surgery, gene expressions of PPARγ, FABP4, and CD36 were mostly downregulated. In our in vitro experiments, we observed a concentration-dependent increase in Oil Red O staining in Hc3716 cells after treatment with the free fatty acids. Alongside this change, the expression of INTS6, PPARγ, and adipocyte-specific genes was induced. INTS6 knockdown using siRNA significantly suppressed cellular lipid accumulation together with induction of ß-catenin and PPARγ downregulation. Collectively, INTS6 expression closely correlates with PPARγ. INTS6 suppression significantly reduced hepatocyte steatosis via ß-catenin-PPARγ axis, indicating that INTS6 could be a novel therapeutic target for treating MASH.

Assessing the Influence of the COVID-19 Pandemic on Gastric Cancer Mortality Risk.

BACKGROUND: The global impact of the coronavirus disease 2019 (COVID-19) pandemic on public health has been significant. Upper gastrointestinal endoscopy for screening and diagnosis decreased along with new gastric cancer (GC) diagnoses. METHODS: This study assesses how the pandemic affected GC mortality using data from Hiroshima Prefecture, comparing mortality rates between patients diagnosed during the pandemic (2020 and 2021) and pre-pandemic (2018 and 2019) periods. The crude hazard ratios (HRs) and HRs adjusted for age, sex, clinical stage, treatment status, and travel distance to the nearest GC screening facility were estimated using Cox regression models. Subgroup and sensitivity analyses were also performed. RESULTS: A total of 9571 patients were diagnosed, with 4877 eligible for follow-up. The median age was 74 years, and 69% were male. The median follow-up period was 157 days, with events per 1000 person-years at 278 and 374 in the pre-pandemic and pandemic periods, respectively (crude HR, 1.37; adjusted HR, 1.17). The sensitivity and subgroup analyses yielded consistent results. CONCLUSIONS: The COVID-19 pandemic increased mortality risk in patients with GC. Further studies are required to observe long-term outcomes and identify the disparities contributing to the increased mortality risk.

The impact of early-stage COVID-19 pandemic on the diagnosis and treatment of gastric cancer: A cross-sectional study using a large-scale cancer registry in Hiroshima, Japan.

Background: After the confirmation of coronavirus infection in Japan, a behavioral change caused people and physicians to refrain from visiting hospitals or undergoing examinations. This study aimed to assess how the trend of diagnosis in gastric cancers changed, and how it affected the therapeutic strategies and the interval from diagnosis to treatment during the COVID-19 pandemic. Methods: We use 15 cancer-designated hospitals' registries in Hiroshima, Japan. The target period was March to December 2020, and the same period in 2019 was set as the control period. The monthly mean of diagnoses and the interval from diagnosis to treatment were compared overall and separately by age, treatment procedure, diagnostic process, and clinical stage. Result: In 2020, the monthly mean (standard deviation [SD]) of patients was 192.2 (29.9), a significant 20.1% decrease from 240.7 (20.7) in 2019 due to older age and curative treatment groups. By reason for performing endoscopy, the change rate in cancer screening, endoscopic follow-up, and symptomatic status were -27.0%, -18.0%, and -17.3%, respectively. Meanwhile, the interval (days) from diagnosis to treatment (SD) was 37.8 (26.5) in 2020, significantly shorter than 46 (31.5) in 2019. Conclusion: From 2019 to 2020, we observed a significant decrease in the diagnosis of curable early-stage gastric cancer and treatments, although the interval from diagnosis to treatment decreased. This study suggests that cancer screening played a significant role in the decline in cancer diagnosis that occurred during the COVID-19 pandemic. Even under COVID-19 pandemic conditions, there should be an awareness of cancer screening and endoscopic follow-up.

Case of non-secretory multiple myeloma eventually diagnosed by 18F-FDG PET/CT.

Non-secretory multiple myeloma (NSMM) is a rare type of multiple myeloma characterized by the absence of the M protein, making its diagnosis challenging. Here, we report a 67-year-old female patient eventually diagnosed as NSMM with positron emission tomography-computed tomography (PET/CT) imaging as a clue.

Granulocyte Colony-stimulating Factor-induced Aortitis with Lung Injury, Splenomegaly, and a Rash During Treatment for Recurrent Extraosseous Mucinous Chondrosarcoma.

We herein report a case of aortitis induced by granulocyte colony-stimulating factor (G-CSF) that coincided with lung injury, splenomegaly, and cutaneous manifestations during treatment for recurrent extraosseous mucinous chondrosarcoma. Computed tomography revealed large-vessel vasculitis, splenomegaly, and pulmonary interstitial changes. Treatment with prednisolone was successful. Because sarcoma is a rare disease, this case is valuable for showing clinicians that G-CSF preparations could cause aortitis regardless of the patient's underlying diseases or therapeutic pharmacological backgrounds.

Senescent hepatic stellate cells caused by deoxycholic acid modulates malignant behavior of hepatocellular carcinoma.

PURPOSE: Deoxycholic acid (DCA), a secondary bile acid, is reportedly increased in the serum of patients with nonalcoholic steatohepatitis and animals with experimentally induced hepatocellular carcinoma (HCC), but its contribution to malignant behaviors of HCC has not been precisely clarified. This study aimed to examine the effect of DCA on hepatic stellate cells (HSCs), a major component of nonparenchymal cells in the liver, and its subsequent indirect effect on HCC cells. METHODS: LX2 cells, a human HSC line, were treated with DCA in vitro. Then, HuH7 cells, a human hepatoma cell line, were incubated in conditioned media of DCA-treated LX2 to investigate the subsequent effect focusing on malignant behaviors. RESULTS: DCA resulted in cellular senescence in LX2 with the decreased cell proliferation via cell cycle arrest at G0/1 phase, together with the induction of senescence-associated secretory phenotype (SASP) factors. To investigate the influence of SASP factors secreted by HSCs in response to DCA, HCC cells were treated with conditioned media that promoted cell migration and invasion via induction of epithelial mesenchymal transition. These changes were attenuated in the presence of neutralizing antibody against IL8 or TGFß. Pathological analysis of surgical specimens from HCC patients revealed that senescent HSCs were detected in the stroma surrounding HCC. CONCLUSION: Our data suggest an important role of HSC senescence caused by DCA for the malignant biological behaviors of HCC via induction of SASP factors, particularly IL8 and TGFß.

Protective effect of phosphatidylcholine on lysophosphatidylcholine-induced cellular senescence in cholangiocyte.

BACKGROUND: Pancreaticobiliary maljunction and intrahepatic gallstones are at a high risk for biliary malignancy. Lysophosphatidylcholine (LPC) is increased in the bile of these patients, and we have previously reported that LPC-induced cytotoxicity causes senescence-associated secretory phenotype (SASP) in cholangiocytes. We aimed to determine the protective effect of phosphatidylcholine (PC) on LPC-induced cholangiocyte cytotoxicity. METHODS: MMNK-1, a human immortalized cholangiocyte cell line was treated with LPC with or without PC. To assess the biological effects of SASP components on cholangiocarcinoma, HuH28 and HuCCT1 (human cholangiocarcinoma cell lines) were cultured in the conditioned media where MMNK-1 cells treated with LPC. RESULTS: The presence of PC reduced reactive oxygen species generation and oxidative DNA damage in MMNK-1 treated with LPC. Moreover, SA-ß-gal activity was markedly downregulated by PC. The secretion of SASP components, including interleukin (IL)-8, IL-6, and C-C motif chemokine ligand 2 was also substantially reduced in the presence of PC. Cellular proliferation and migration were enhanced in HuCCT1 and HuH28 cells when cultured in the conditioned media, and these observations were suppressed by simultaneous addition of PC. CONCLUSION: PC protects cholangiocytes against LPC-induced cytotoxicity and cellular senescence, suggesting its potential as a target for inhibiting LPC-related carcinogenesis and its promotion.

An Atypical Case of Non-asthmatic Eosinophilic Granulomatosis with Polyangiitis Finally Diagnosed by Tissue Biopsy.

A 78-year-old woman with fever of unknown origin that had persisted for 3 months, systemic edema, and cervical lymphadenopathy was admitted to our hospital. Skin purpura and jaw claudication were subsequently observed. Histopathological examinations of the lymph nodes, skin, and temporal artery revealed findings characteristic of eosinophilic granulomatosis with polyangiitis (EGPA). However, she had no past medical history of asthma with modest eosinophilia. Although EGPA is a systemic vasculitis characterized by asthma and eosinophilia, various limited forms have been described. This was therefore considered to be an atypical form of non-asthmatic EGPA complicating with temporal arteritis (TA) diagnosed by tissue biopsy.

Primary Signet Ring Cell Carcinoma of Rectum Diagnosed by Boring Biopsy in Combination with Endoscopic Mucosal Resection.

A 46-year-old man with severe back pain visited our hospital. Magnetic resonance imaging revealed extensive bone metastasis and rectal wall thickness. Colonoscopy revealed circumferential stenosis with edematous mucosa, suggesting colon cancer. However, histological findings of biopsy specimens revealed inflammatory cells but no malignant cells. The patient underwent endoscopic ultrasound, which demonstrated edematous wall thickness without destruction of the normal layer structure. After unsuccessful detection of neoplastic cells by boring biopsies, we performed endoscopic mucosal resection followed by boring biopsies that finally revealed signet ring cell carcinoma. Herein, we present a case and provide a review of the literature.

Periostin promotes malignant potential by induction of epithelial-mesenchymal transition in intrahepatic cholangiocarcinoma.

Periostin, a secreted matricellular protein, has been reported to induce epithelial-mesenchymal transition (EMT), which increases motility and invasiveness in various epithelial cancer cells. Periostin is also overexpressed in intrahepatic cholangiocarcinoma (ICC) and suggested to be a biomarker for tumor progression and poor prognosis; however, its functional role in ICC is not fully understood. Here, we investigated whether periostin influences malignant potential through the induction of EMT in ICC. Analyses of surgical resected ICC specimens revealed that the gene expression of periostin was significantly higher in ICC tumors than in adjacent nontumor liver tissues and was closely correlated with the expression of mesenchymal markers, including N-cadherin, vimentin, and fibronectin. However, the expression level of periostin varied in each case. Consistently, the expression of periostin in HuH28 (an undifferentiated ICC cell) was markedly higher than in HuCCT-1 (a moderately differentiated ICC cell). In addition, high-level secretion of periostin into culture media was observed in HuH28 but not in HuCCT-1. To identify the biological significance of periostin in EMT, gene silencing of periostin by small interfering RNA was performed in HuH28 cells. Periostin knockdown in HuH28 cells significantly down-regulated mesenchymal markers and up-regulated epithelial markers, suggesting the reversal of EMT, namely mesenchymal-epithelial transition. Along with these changes, cell proliferation was significantly suppressed by 52%. In addition, cell migration and invasion were significantly suppressed by 62% and 61%, respectively, with reduced gene expression of matrix metalloproteinase 2. Interestingly, chemosensitivity to gemcitabine was also significantly improved by periostin depletion. Conclusion: Periostin plays an important role in the regulation of malignant potential through EMT and is suggested to be a novel target for the treatment of ICC. (Hepatology Communications 2017;1:1099-1109).

Systemic Inflammatory Syndrome Associated with a Case of Jugular Paraganglioma.

Jugular paraganlioma is a benign, slow-growing tumor originating from the paraganglion cells and it is associated with catecholamine secretion. Paragangliomas can secrete Interleukin-6 (IL-6) and present as a systemic inflammatory syndrome; these characteristics have not been previously associated with jugular paragangliomas. A 63-year-old man with a jugular tumor in the skull base was referred to our hospital for an evaluation of pyrexia, back pain, and acute inflammation. His serum IL-6 level was elevated on admission and it decreased after radiotherapy. This is the first known case of a jugular paraganglioma exhibiting systemic inflammatory syndrome.

Cholangiocyte senescence caused by lysophosphatidylcholine as a potential implication in carcinogenesis.

BACKGROUND: The incidence of biliary tract cancer in patients with pancreaticobiliary maljunction or intrahepatic cholelithiasis is markedly high with undefined mechanism. In these diseases, biliary lysophosphatidylcholine (LPC) level is reportedly increased. This study investigated the influence of LPC on cholangiocytes focusing on cellular senescence and its potential contribution to carcinogenesis. METHODS: Cultured MMNK-1, an immortalized human cholangiocyte was treated with LPC in vitro and its effect was evaluated. RESULTS: Lysophosphatidylcholine demonstrated cytotoxicity with generation of intracellular reactive oxygen species. Accordingly, LPC provoked oxidative DNA injury, whereas the gene expressions of DNA repair enzyme (OGG1, MUTYH, MTH1) remained unchanged. Interestingly, LPC caused global DNA hypomethylation, which is frequently observed in cancer tissues. Microarray analysis identified differentially regulated genes in response to LPC, which included the components of senescence-associated secretory phenotype (SASP) including interleukin-8 (IL-8), IL-6, transforming growth factor-ß and plasminogen activator inhibitor-1. Significant induction of these genes was further confirmed by quantitative real-time polymerase chain reaction. In addition to upregulation of p21 gene expression, senescence-associated beta-galactosidase activity, a widely used marker of cellular senescence was significantly induced by the treatment of LPC. CONCLUSIONS: Based on these data, cholangiocyte senescence and SASP caused by LPC are potential pathogenic mechanisms in the development of biliary tract cancer.

Partial characterization of proapoptotic action of biliary deteriorated lipids on biliary epithelial cells in pancreaticobiliary diseases.

BACKGROUND: Lysophosphatidylcholine (LPC), a derivative of phosphatidylcholine (PC) hydrolyzed by phospholipase A2 (PLA2), is reported to be increased in bile of the patients with pancreaticobiliary maljunction or intrahepatic cholelithiasis, both of which are major risk factors for biliary tract cancers with undefined etiology. METHODS: To investigate the influence of LPC on biliary epithelial cells (BECs), a human cholangiocarcinoma cell line HuCCT-1 and an immortalized human BECs line MMNK-1 were treated by LPC in vitro. RESULTS: The treatment of LPC exhibited cytotoxicity with significant induction of apoptosis. In addition to upregulation of Fas receptor mRNA, the activities of caspase-8 and -3 were significantly increased by LPC treatment. We also observed upregulation of Bax mRNA and significant activation of caspase-9. Interestingly, LPC significantly upregulated G2A, a member of transmembrane G protein-coupled receptor family at mRNA and protein levels, and 9-hydroxyoctadecaduenoic acid (9HODE), an oxidized free fatty acid that functions as a ligand for G2A dramatically reduced cell viability when treated together with LPC. CONCLUSIONS: These data suggest that PLA2, which catalyzes the hydrolysis of PC to yield LPC and free fatty acid, is supposed to be an important etiological factor in BECs injury in pancreaticobiliary maljunction or intrahepatic cholelithiasis.

Nutritional factors (nutritional aspects) in biliary disorders: bile acid and lipid metabolism in gallstone diseases and pancreaticobiliary maljunction.

Nutritional factors play a key role in the pathogenesis of biliary diseases such as gallstones and pancreaticobiliary maljunction. Gallstones are primarily classified into cholesterol stone and pigment stone according to the major composition. Cholesterol gallstone formation is very likely based upon supersaturated bile formation, and pigment stones are formed in bile rich in bilirubin. Thus, defects of hepatic metabolism of lipids and organic anions lead to biliary stones. Here, the recent understanding of cholesterol gallstone pathogenesis is elaborated. On the other hand, there is another important link of biliary lipid degradation to serious biliary disease, namely pancreaticobiliary maljunction. Lysophosphatidylcholine (lysoPC), a derivative of phosphatidylcholine hydrolysis by phospholipase A2, is a highly abundant bioactive lipid mediator present in circulation as well as in bile. Increases in bile of lysoPC and phospholipase A2 have been reported in pancreaticobiliary maljunction and considered to be the major risk factor for biliary tract cancers. Further, oxidized fatty acids have been established as a potent ligand for G2A, a member of G protein-coupled receptor family that mediates a diverse array of biological processes including cell growth and apoptosis. Thus, both of lysoPC and free fatty acids are supposed to play an important role through G2A in biliary inflammation and carcinogenesis of pancreaticobiliary maljunction. Taken together, nutritional factors, especially lipid compounds, are seemingly crucial in the pathogenesis of biliary diseases, and such a causal relationship is reviewed by mainly authors' previous publications.

Lack of adiponectin promotes formation of cholesterol gallstones in mice.

Plasma adiponectin levels are reduced in obese people, and hypoadiponectinemia is recently reported to associate with cholesterol gallstone formation in human. The aim of this study was to examine the role of adiponectin in gallstone formation using adiponectin knockout mice. We analyzed male knockout and C57BL6J mice fed normal or lithogenic diet for 6 weeks. On lithogenic diet, the prevalence rate of gallstone was significantly greater in knockout mice than C57BL6J mice. The molar percentages of beta and omega-muricholic acid were significantly higher and hepatic sterol 12 alpha-hydroxylase expression (cyp8b1) was significantly lower in knockout mice than C57BL6J mice fed normal diet. The bile apolipoprotein A-I protein levels were decreased in knockout mice. Histological examination showed gallbladder wall thickening and accumulation of glycoprotein in the gallbladder of knockout mice. Gallbladder phospholipase A2-IVA expression was significantly higher in knockout mice than in C57BL6J mice fed lithogenic diet. Our results indicate that lack of adiponectin promotes gallstone formation in mice.

Cytoprotective effect of tauroursodeoxycholate on hepatocyte apoptosis induced by peroxisome proliferator-activated receptor gamma ligand.

BACKGROUND AND AIM: Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands inhibit cell growth and induce apoptosis in various cancer cells. Bile acids are also known to cause hepatocyte apoptosis through nuclear receptor-mediated mechanisms. The aim of this study was to examine the effect of two different bile acid species on the inhibitory action of PPARgamma in cell growth with paying attention to the role of the mitogen-activated protein kinase pathway as an underlying mechanism. METHODS: Immortalized human hepatocytes (OUMS-29) and hepatoma cells (HepG2 and Huh7) were incubated with troglitazone (TGZ), a PPARgamma ligand with or without pre-incubation of either hydrophobic glycochenodeoxycholate (GCDC) or hydrophilic tauroursodeoxycholate (TUDC). RESULTS: TGZ induced cell apoptosis in all cell types, resulting in the reduction of cell viability. While pre-incubation with GCDC enhanced the apoptotic effects of TGZ, TUDC significantly attenuated it. Both bile acids enhanced p38 and c-Jun N-terminal kinase (JNK) phosphorylation in a similar way, whereas there was more drastic enhancement of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation in the presence of TUDC compared to GCDC. In addition, ERK inhibitors suppressed the action of TUDC against apoptotic effect of TGZ. CONCLUSION: This study demonstrates that TUDC exhibits anti-apoptotic and cytoprotective effects against TGZ-induced cell apoptosis, presumably through the ERK signaling pathway. We speculate that the administration of TUDC might be one of the potential strategies for the hepatotoxicity caused by TGZ.

AT1A-deficient mice show less severe progression of liver fibrosis induced by CCl(4).

The renin-angiotensin system has been shown to contribute to fibrogenesis in varieties of organs, including the liver. Here, we investigated whether the angiotensin II type 1A receptor (AT1A) is implicated in the development of liver fibrosis, using AT1A-deficient and wild-type (WT) mice. After single dose of carbon tetrachloride (CCl(4)), there were no significant differences between two groups with regard to hepatic inflammation and necrosis. After 4 weeks of treatment with CCl(4), histological examination revealed that AT1A-deficient mice showed less infiltration of inflammatory cells and less severe progression of liver fibrosis compared with WT mice. These findings were accompanied by the hepatic content of hydoxyproline and the expression of alpha-smooth muscle actin (alpha SMA). The level of transforming growth factor-beta 1 (TGF-beta 1) messenger RNA was markedly higher in WT mice when compared with AT1A-deficient mice. These results confirm that signaling via AT1A plays a pivotal role in hepatic fibrogenesis.

Unique reciprocal changes of hepatocellular membrane transporter expression and fluidity in rats with selective biliary obstruction.

BACKGROUND AND AIMS: The localized occlusion of bile ducts by intrahepaticlithiasis and intrahepatic neoplasms dose not cause severe jaundice, although the reason is unclear. The aim of this study was to clarify the molecular change of the liver in partial cholestasis, especially with respect to transporter expression (Mrp2, Mrp3, Bsep, P-gps) and membrane fluidity. METHODS AND RESULTS: After 3 days of selective bile duct ligation in Sprague-Dawley rats, the obstructed lobe (OL) and non-OL were analyzed. Canalicular and sinusoidal membrane fluidity were decreased in the OL compared with the non-OL. Mrp2 protein expression was significantly lower in the OL (by 62.9+/-6.9%) when compared with the non-OL. Mdr1b and Mdr2 mRNA were up-regulated in the OL when compared with the non-OL. Interestingly, Mrp3 protein and mRNA were induced in both the non-OL and OL of rats without hyperbilirubinemia. CONCLUSIONS: It seems that the reduction of membrane fluidity in the OL is a local response to localized cholestasis, while the induction of Mrp3 observed in both the OL and non-OL may be a response of the whole liver to localized impairment of bile secretion, although the regulatory mechanism is yet to be established.