Browsing by Author "Saxena, Romil"

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    The Apelin–Apelin Receptor Axis Triggers Cholangiocyte Proliferation and Liver Fibrosis During Mouse Models of Cholestasis
    (Wiley, 2021-06) Chen, Lixian; Zhou, Tianhao; White, Tori; O'Brien, April; Chakraborty, Sanjukta; Liangpunsakul, Suthat; Yang, Zhihong; Kennedy, Lindsey; Saxena, Romil; Wu, Chaodong; Meng, Fanyin; Huang, Qiaobing; Francis, Heather; Alpini, Gianfranco; Glaser, Shannon; Medicine, School of Medicine
    Background and Aims Apelin (APLN) is the endogenous ligand of its G protein–coupled receptor, apelin receptor (APJ). APLN serum levels are increased in human liver diseases. We evaluated whether the APLN–APJ axis regulates ductular reaction and liver fibrosis during cholestasis. Approach and Results We measured the expression of APLN and APJ and serum APLN levels in human primary sclerosing cholangitis (PSC) samples. Following bile duct ligation (BDL) or sham surgery, male wild-type (WT) mice were treated with ML221 (APJ antagonist) or saline for 1 week. WT and APLN−/− mice underwent BDL or sham surgery for 1 week. Multidrug resistance gene 2 knockout (Mdr2−/−) mice were treated with ML221 for 1 week. APLN levels were measured in serum and cholangiocyte supernatants, and cholangiocyte proliferation/senescence and liver inflammation, fibrosis, and angiogenesis were measured in liver tissues. The regulatory mechanisms of APLN–APJ in (1) biliary damage and liver fibrosis were examined in human intrahepatic biliary epithelial cells (HIBEpiCs) treated with APLN and (2) hepatic stellate cell (HSC) activation in APLN-treated human HSC lines (HHSteCs). APLN serum levels and biliary expression of APLN and APJ increased in PSC samples. APLN levels were higher in serum and cholangiocyte supernatants from BDL and Mdr2−/− mice. ML221 treatment or APLN−/− reduced BDL-induced and Mdr2−/−-induced cholangiocyte proliferation/senescence, liver inflammation, fibrosis, and angiogenesis. In vitro, APLN induced HIBEpiC proliferation, increased nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) expression, reactive oxygen species (ROS) generation, and extracellular signal–regulated kinase (ERK) phosphorylation. Pretreatment of HIBEpiCs with ML221, diphenyleneiodonium chloride (Nox4 inhibitor), N-acetyl-cysteine (NAC, ROS inhibitor), or PD98059 (ERK inhibitor) reduced APLN-induced cholangiocyte proliferation. Activation of HHSteCs was induced by APLN but reduced by NAC. Conclusions The APLN–APJ axis induces cholangiocyte proliferation through Nox4/ROS/ERK-dependent signaling and HSC activation through intracellular ROS. Modulation of the APLN–APJ axis may be important for managing cholangiopathies.
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    Autotaxin expression and its connection with the TNF-alpha-NF-κB axis in human hepatocellular carcinoma
    (BMC, 2010-03-31) Wu, Jian-Min; Xu, Yan; Skill, Nicholas J.; Sheng, Hongmiao; Zhao, Zhenwen; Yu, Menggang; Saxena, Romil; Maluccio, Mary A.; Surgery, School of Medicine
    Background Autotaxin (ATX) is an extracellular lysophospholipase D that generates lysophosphatidic acid (LPA) from lysophosphatidylcholine (LPC). Both ATX and LPA have been shown to be involved in many cancers. However, the functional role of ATX and the regulation of ATX expression in human hepatocellular carcinoma (HCC) remain elusive. Results In this study, ATX expression was evaluated in tissues from 38 human HCC and 10 normal control subjects. ATX was detected mainly in tumor cells within tissue sections and its over-expression in HCC was specifically correlated with inflammation and liver cirrhosis. In addition, ATX expression was examined in normal human hepatocytes and liver cancer cell lines. Hepatoma Hep3B and Huh7 cells displayed stronger ATX expression than hepatoblastoma HepG2 cells and normal hepatocytes did. Proinflammtory cytokine tumor necrosis factor alpha (TNF-α) promoted ATX expression and secretion selectively in Hep3B and Huh7 cells, which led to a corresponding increase in lysophospholipase-D activity. Moreover, we explored the mechanism governing the expression of ATX in hepatoma cells and established a critical role of nuclear factor-kappa B (NF-κB) in basal and TNF-α induced ATX expression. Further study showed that secreted enzymatically active ATX stimulated Hep3B cell invasion. Conclusions This report highlights for the first time the clinical and biological evidence for the involvement of ATX in human HCC. Our observation that links the TNF-α/NF-κB axis and the ATX-LPA signaling pathway suggests that ATX is likely playing an important role in inflammation related liver tumorigenesis.
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    Consensus Recommendations for Histological Criteria of Autoimmune Hepatitis from the International AIH Pathology Group
    (Wiley, 2022-05) Lohse, Ansgar W.; Sebode, Marcial; Bhathal, Prithi S.; Clouston, Andrew D.; Dienes, Hans P.; Jain, Dhanpat; Gouw, Annette S. H.; Guindi, Maha; Kakar, Sanjay; Kleiner, David E.; Krech, Till; Lackner, Carolin; Longerich, Thomas; Saxena, Romil; Terracciano, Luigi; Washington, Kay; Weidemann, Sören; Hübscher, Stefan G.; Tiniakos, Dina; Pathology and Laboratory Medicine, School of Medicine
    Background & Aims Diagnostic histological criteria for autoimmune hepatitis (AIH) have not been clearly established. Previously published criteria focused mainly on chronic AIH, in which inflammatory changes mainly occur in portal/periportal regions and may not be applicable to acute presentation of AIH, in which inflammatory changes are typically predominantly lobular in location. International consensus criteria for the diagnosis and assessment of disease severity in both acute and chronic AIH are thus urgently needed. Methods Seventeen expert liver pathologists convened at an international workshop and subsequently used a modified Delphi panel approach to establish consensus criteria for the histopathological diagnosis of AIH. Results The consensus view is that liver biopsy should remain standard for diagnosing AIH. AIH is considered likely, if there is a predominantly portal lymphoplasmacytic hepatitis with more than mild interface activity and/or more than mild lobular hepatitis in the absence of histological features suggestive of another liver disease. AIH is also considered likely if there is predominantly lobular hepatitis with or without centrilobular necroinflammation and at least one of the following features: portal lymphoplasmacytic hepatitis, interface hepatitis or portal-based fibrosis, in the absence of histological features suggestive of another liver disease. Emperipolesis and hepatocellular rosettes are not regarded as being specific for AIH. Conclusions The criteria proposed in this consensus statement provide a uniform approach to the histological diagnosis of AIH, which is relevant for patients with an acute as well as a chronic presentation and to more accurately reflect the current understanding of liver pathology in AIH.
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    Effect of different obesogenic diets on pancreatic histology in Ossabaw miniature swine
    (Wolters Kluwer, 2011-04) Fullenkamp, Allison M.; Bell, Lauren N.; Robbins, Reiesha D.; Lee, Lydia; Saxena, Romil; Alloosh, Mouhamad; Klaunig, James E.; Mirmira, Raghavendra G.; Sturek, Michael; Chalasani, Naga; Department of Medicine, IU School of Medicine
    OBJECTIVE: Obesity is a factor in the outcome and severity of pancreatic conditions. We examined the effect of hypercaloric diets on the pancreata of Ossabaw swine, a large animal model of metabolic syndrome and obesity. METHODS: Swine were fed with 1 of 4 diets: high-fructose (n = 9), atherogenic (n = 10), modified atherogenic (n = 6), or eucaloric standard diet (n = 12) for 24 weeks. Serum chemistries were measured, and pancreata were examined for histological abnormalities including steatosis, inflammation or fibrosis, insulin content, and oxidative stress. RESULTS: The fructose, atherogenic, and modified atherogenic diet groups exhibited obesity, metabolic syndrome, islet enlargement, and significantly increased pancreatic steatosis (22.9% ± 7.5%, 19.7% ± 7.7%, and 38.7% ± 15.3% fat in total tissue area, respectively) compared with controls (9.3% ± 1.9%; P < 0.05). The modified atherogenic diet group showed significantly increased oxidative stress levels as evidenced by elevated serum malondialdehyde (3.0 ± 3.3 vs 1.5 ± 0.3 μmol/L in controls; P = 0.006) and pancreatic malondialdehyde (0.1 ± 0.12 vs 0.04 ± 0.01 nmol/mg protein in controls; P = 0.01). None of the swine exhibited pancreatitis or cellular injury. CONCLUSIONS: Ossabaw swine fed with a modified atherogenic diet developed significant pancreatic steatosis and increased oxidative stress, but no other histological abnormalities were observed.
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    Evaluation of 11C-Acetate and 18 F-FDG PET/CT in mouse multidrug resistance gene-2 deficient mouse model of hepatocellular carcinoma
    (BioMed Central, 2015-05) Territo, Paul R.; Maluccio, Mary; Riley, Amanda A.; McCarthy, Brian P.; Fletcher, James; Tann, Mark; Saxena, Romil; Skill, Nicholas J.; Department of Radiology and Imaging, IU School of Medicine
    Background Hepatocellular carcinoma (HCC) remains a global health problem with unique diagnostic and therapeutic challenges, including difficulties in identifying the highest risk patients. Previous work from our lab has established the murine multidrug resistance-2 mouse (MDR2) model of HCC as a reasonable preclinical model that parallels the changes seen in human inflammatory associated HCC. The purpose of this study is to evaluate modalities of PET/CT in MDR2−/− mice in order to facilitate therapeutic translational studies from bench to bedside. Methods 18F-FDG and 11C-acetate PET/CT was performed on 12 m MDR2−/− mice (n = 3/tracer) with HCC and 12 m MDR2−/+ control mice (n = 3/tracer) without HCC. To compare PET/CT to biological markers of HCC and cellular function, serum alpha-fetoprotein (AFP), lysophosphatidic acid (LPA), cAMP and hepatic tumor necrosis factor α (TNFα) were quantified in 3-12 m MDR2−/− (n = 10) mice using commercially available ELISA analysis. To translate results in mice to patients 11C-acetate PET/CT was also performed in 8 patents suspected of HCC recurrence following treatment and currently on the liver transplant wait list. Results Hepatic18F-FDG metabolism was not significantly increased in MDR2−/− mice. In contrast, hepatic 11C-acetate metabolism was significantly elevated in MDR2−/− mice when compared to MDR2−/+ controls. Serum AFP and LPA levels increased in MDR2−/− mice contemporaneous with the emergence of HCC. This was accompanied by a significant decrease in serum cAMP levels and an increase in hepatic TNFα. In patients suspected of HCC recurrence there were 5 true positives, 2 true negatives and 1 suspected false 11C-acetate negative. Conclusions Hepatic 11C-acetate PET/CT tracks well with HCC in MDR2−/− mice and patients with underlying liver disease. Consequently 11C-acetate PET/CT is well suited to study 1) HCC emergence/progression in patients and 2) reduce animal numbers required to study new chemotherapeutics in murine models of HCC.
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    Hepatic Arterial Buffer Response: Pathologic Evidence in Non-Cirrhotic Human Liver with Portal Vein Thrombosis
    (Office of the Vice Chancellor for Research, 2016-04-08) Rush, Natalia; Sun, Hongliu; Nakanishi, Yukihiro; Mneimneh, Wadad; Kwo, Paul Y.; Saxena, Romil
    Hepatic arterial buffer response (HABR) is the ability of the hepatic artery (HA) to compensate for changes in portal flow. Experimentally, occlusion of the portal vein leads to compensatory increase in HA flow with minimal parenchymal effects. Wether portal vein thrombosis (PVT) causes similar effects in the human liver is unknown. This study aims to answer this question as well as elucidate any microscopic features that may reliably assist diagnosis of PVT in the non-cirrhotic liver. We studied patients with PVT and no concomitant liver pathology. Age and gender matched livers with normal morphology served as controls. Following parameters were graded as subtle or obvious and focal or diffuse in a blinded fashion: sinusoidal dilatation, central and portal vein (PV) dilatation, PV absence, hepatic plate thinning and thickening. Outer and luminal diameters and wall thickness of HA, and outer diameter of accompanying bile ducts (BD) were measured. There were 16 patients (8 men, 8 women; mean age, 46.5 years) who presented with varices (12), ascites (8) and splenomegaly (11). Subtle and or focal dilatations of CV, PV and sinusoids as well as thinning/thickening of hepatic plates were common findings in both groups but were diffuse and obvious predominantly in cases of PVT. Absence or attenuation of PV was seen only in cases of PVT. The large HA were dilated in resection specimens of patients with PVT, p<0.05. This difference was not seen in biopsy specimens. There was no difference in the small HA in either biopsy or resection specimens or other measurements of HA or BD. In conclusion, septal branches of the HA dilate as a compensatory response to long standing thrombosis. Microscopic features of PVT are subtle but when obvious and/or diffuse in a patient with non-cirrhotic portal hypertension should raise suspicion for this diagnosis.
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    Hepatic lipid peroxidation and cytochrome P-450 2E1 in pediatric nonalcoholic fatty liver disease and its subtypes
    (Wolters Kluwer, 2011-10) Bell, Lauren N.; Molleston, Jean P.; Morton, Michael J.; Klipsch, Ann; Saxena, Romil; Vuppalanchi, Raj; Chalasani, Naga; Department of Medicine, IU School of Medicine
    GOAL: To compare hepatic lipid peroxidation and cytochrome P-450 2E1 (CYP2E1) protein content in liver biopsies from children with nonalcoholic fatty liver disease (NAFLD) and 2 control groups. BACKGROUND: Elevated hepatic lipid peroxidation resulting from increased hepatic CYP2E1 enzyme activity is involved in the pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH) in adults, but studies in children are lacking. STUDY: Liver biopsies from 59 children with NAFLD (49 with NASH), 10 children with normal liver histology, and 9 children with mild chronic hepatitis C (HCV) infection were examined. Hepatic malondialdehyde (a measure of lipid peroxidation) levels and CYP2E1 protein content were quantitated, as a percentage of the total area, by immunohistochemical staining of liver biopsy material followed by digital image quantitation. RESULTS: Lipid peroxidation was significantly greater in NAFLD liver biopsies (46.7 ± 20.8%) compared with biopsies from children with normal liver histology (7.6 ± 9.4%; P<0.001) or HCV infection (7.7 ± 7.6%; P<0.001). However, hepatic CYP2E1 expression was not different across the NAFLD, normal liver histology, and HCV groups (60.7 ± 8.7%, 53.5 ± 10.7%, and 60.0 ± 11.9%, respectively; P=0.116). Among children with NAFLD, lipid peroxidation and CYP2E1 protein content did not differ between biopsies with and without NASH. Body mass index was independently associated with hepatic lipid peroxidation levels (r=0.549; P<0.001). CONCLUSIONS: Hepatic lipid peroxidation is increased in children with NAFLD but this is not related to hepatic CYP2E1 expression. No difference in lipid peroxidation in pediatric NAFLD versus NASH argues against a role in disease progression.
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    A High Serum Level of Taurocholic Acid is Correlated with the Severity and Resolution of Drug-induced Liver Injury
    (Elsevier, 2020) Tian, Qiuju; Yang, Ruiyuan; Wang, Yan; Liu, Jimin; Wee, Aileen; Saxena, Romil; Wang, Lan; Li, Min; Liu, Liwei; Shan, Shan; Kong, Yuanyuan; Ma, Hong; Ou, Xiaojuan; You, Hong; Zhao, Xinyan; Jia, Jidong; Pathology and Laboratory Medicine, School of Medicine
    Background & Aims Alterations in the serum levels of bile acids are associated with drug-induced liver injury (DILI). We investigated the association between serum levels of bile acids and the severity and outcome of DILI, along with the potential role of variants in the ATP binding cassette subfamily B member 11 ( ABCB11) gene and expression of its product, ABCB11 (also called BSEP). Methods We performed this prospective study of 95 patients (median age, 53 years; 73.7% female) with DILI from August 2018 through August 2019. Patients were matched for age, gender, and body mass index with healthy individuals (n=100; healthy controls) and patients with chronic hepatitis B (n=105; CHB controls). We collected demographic and biochemical data at baseline and 1 week, 1 month, 3 months, and 6 months after DILI onset and at the time of biochemical recovery, liver failure or liver transplantation. Serum levels of bile acids were measured using high-performance liquid-chromatography tandem mass-spectrometry. All 27 exons of ABCB11 were sequenced and expression of BSEP were analyzed by immunohistochemistry in liver biopsy specimens. Results Levels of 30 of the 37 bile acids analyzed differed significantly between patients with DILI and healthy controls. Changes in levels of taurocholic acid (TCA), glycocholic acid, taurochenodeoxycholate, and glycochenodeoxycholate associated with the increased levels of bilirubin and greater severity of DILI, and were also associated with CHB. Cox regression analysis showed that only change in the levels of TCA independently associated with biochemical resolution of DILI. Combination of TCA level (≥ 1955.41 nmol/L), patient age, and DILI severity was associated with abnormal blood biochemistry at 6 months after DILI onset (area under the curve, 0.81; 95% confidence interval, 0.71–0.88; sensitivity, 0.69; specificity, 0.81). ABCB11 missense variants were not associated with differences in the serum bile acid profiles, DILI severity, or clinical resolution. However, lower levels of BSEP in bile canaliculi in liver biopsies were associated with altered serum levels of bile acids. Conclusions In this prospective study performed in Chinese patients, we found that the serum levels of TCA were associated with the severity and clinical resolution of DILI. Reduced protein expression of BSEP in liver tissue, rather than variants of the ABCB11 gene were associated with altered serum levels of bile acids.
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    HLA-DR Mismatch and Black Race Are Associated With Recurrent Autoimmune Hepatitis After Liver Transplantation
    (Wolters Kluwer, 2021-06-10) McCabe, Marshall; Rush, Natalia; Lammert, Craig; Patidar, Kavish R.; Nephew, Lauren; Saxena, Romil; Ekser, Burcin; Salven, James; Kubal, Chandrashekhar; Ghabril, Marwan; Medicine, School of Medicine
    The predictors of recurrent autoimmune hepatitis (R-AIH) after liver transplantation (LT) are heterogeneous with limited data to guide immunosuppression, with little data on impact of race. Aims: To describe the incidence, predictors, and outcomes of R-AIH. Methods: We studied patients undergoing LT for AIH during 2000-2017 at our center. Liver biopsies were performed for clinical indications. R-AIH was defined using clinical and histologic criteria. Results: Among 75 patients undergoing LT for AIH (mean age 45 ± 16, 65% female individuals, 19% Black), 71 (95%) received antithymocyte globulin induction with tacrolimus-based immunosuppression. R-AIH developed in 20 (27%) patients at a median interval of 313 d (interquartile range, 155-1205). R-AIH was associated with level 2 HLA-DR mismatch (hazard ratio, 3.6; (95% confidence interval, 1.3-9.9; P = 0.01) and Black race (hazard ratio, 4.5; 95% confidence interval, 1.8-11.8; P = 0.002)] in the multivariable analysis. R-AIH developed in 62% of patients with level 2 HLA-DR mismatch on single-agent immunosuppression but in <20% of patients with no or 1 HLA-DR mismatch regardless of maintenance immunosuppression. R-AIH developed in 8 (57%) of 14 Black patients (71% on single-agent and 43% on dual-agent maintenance immunosuppression). Patient and graft survival were not impacted by R-AIH over a median follow-up of 8.3 y (interquartile range, 3-12). Conclusions: High-level HLA-DR mismatch and Black recipient race are associated with an increased risk of R-AIH. Immunosuppression did not predict R-AIH, but higher rates of disease recurrence with single-agent maintenance immunosuppression with these risk factors were observed and may guide maintenance immunosuppression in LT for AIH.
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    Increased Mast Cell Counts and Degranulation in Microscopic Colitis
    (Hindawi, 2020) Chi, Zhikai; Xu, Jing; Saxena, Romil; Pathology and Laboratory Medicine, School of Medicine
    Objectives: Microscopic colitis (MC) is characterized by chronic diarrhea, normal colonoscopy findings, and mucosal inflammation in colonic biopsies and can be classified as collagenous colitis (CC) or lymphocytic colitis (LC). However, the pathogenesis of MC is largely unknown. In this study, we aimed to study mast cell counts and activation in MC. Methods: We investigated 64 biopsy samples from the surgical pathology database of Indiana University Health, which met the diagnostic criteria for CC or LC along with 20 control samples collected from 2014 to 2015. The specimens were used for the quantification of mast cells by examining the presence of intracellular and extracellular tryptase by immunohistochemistry. Results: In the lamina propria, the mast cell count was higher in both CC and LC groups than the control (mean highest count, 39/high-power field (HPF) vs. 30/HPF vs. 23/HPF; P < 0.01). Extracellular tryptase was present in 10% of control subjects as compared to 41% of CC (P < 0.01). Extracellular tryptase was present in 10% of control subjects as compared to 41% of CC (P < 0.01). Extracellular tryptase was present in 10% of control subjects as compared to 41% of CC (. Conclusions: The increased mast cell count and degranulation are identified in MC, suggesting that mast cell activation might be involved in the pathogenesis of MC.