Browsing by Subject "Non-alcoholic steatohepatitis"

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    Diet-induced dyslipidemia drives store-operated Ca2+ entry, Ca2+ dysregulation, non-alcoholic steatohepatitis, and coronary atherogenesis in metabolic syndrome
    (2010-07-21T20:06:24Z) Neeb, Zachary P.; Sturek, Michael Stephen; Breall, Jeffrey A.; Considine, Robert V.; Obukhov, Alexander; Tune, Johnathan D.
    Risk of coronary artery disease (CAD), the leading cause of death, greatly increases in metabolic syndrome. Metabolic syndrome (MetS; obesity, insulin resistance, glucose intolerance, dyslipidemia, and hypertension) is increasing in prevalence with sedentary lifestyles and poor nutrition. Non-alcoholic steatohepatitis (NASH; i.e. MetS liver) is progressive and decreases life expectancy, with CAD as the leading cause of death. Pathogenic Ca2+ regulation transforms coronary artery smooth muscle from a healthy, quiescent state to a diseased, proliferative phenotype thus majorly contributing to the development of CAD. In particular, store-operated Ca2+ entry (SOCE) in vascular smooth muscle is associated with atherosclerosis. Genetic predisposition may render individuals more susceptible to Ca2+ dysregulation, CAD, NASH, and MetS. However, the metabolic and cellular mechanisms underlying these disease states are poorly understood. Accordingly, the goal of this dissertation was to investigate the role of dyslipidemia within MetS in the development of Ca2+ dysregulation, CAD, and NASH. The overarching hypothesis was that dyslipidemia within MetS would be necessary for induction of NASH and increased SOCE that would primarily mediate development of CAD. To test this hypothesis we utilized the Ossabaw miniature swine model of MetS. Swine were fed one of five diets for different lengths of time to induce varying severity of MetS. Lean swine were fed normal maintenance chow diet. F/MetS swine were fed high Fructose (20% kcal) diet that induced normolipidemic MetS. TMetS were fed excess high Trans-fat/cholesterol atherogenic diet that induced mildly dyslipidemic MetS and CAD. XMetS were TMetS swine with eXercise. DMetS (TMetS + high fructose) were moderately dyslipidemic and developed MetS and extensive CAD. sDMetS (Short-term DMetS) developed MetS with mild dyslipidemia, but no CAD. MMetS (Mixed-source-fat/cholesterol/fructose) were severely dyslipidemic, exhibited NASH, and developed severe CAD. Dyslipidemia in MetS predicted NASH severity (all groups < DMetS << MMetS), CAD severity (i.e. Lean, F/MetS, sDMetS < XMetS < TMetS < DMetS < MMetS), and was necessary for STIM1/TRPC1-mediated SOCE, which preceded CAD. Exercise ameliorated SOCE and CAD compared to TMetS. In conclusion, dyslipidemia elicits TRPC1/STIM1 SOCE that mediates CAD, is necessary for and predictive of NASH and CAD, and whose affects are attenuated by exercise.
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    Editorial: Nonalcoholic fatty liver disease therapy: Exploring molecular mechanisms of well-defined composition from natural plants
    (Frontiers Media, 2022-09-20) Zhang, Wenji; Huang, Menghao; Liu, Runping; Biochemistry and Molecular Biology, School of Medicine
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    Ethyl Acetate Fraction of Amomum villosum var. xanthioides Attenuates Hepatic Endoplasmic Reticulum Stress-Induced Non-Alcoholic Steatohepatitis via Improvement of Antioxidant Capacities
    (MDPI, 2021-06-23) Cho, Jung-Hyo; Lee, Jong-Suk; Kim, Hyeong-Geug; Lee, Hye Won; Fang, Zhigang; Kwon, Hyeok-Hee; Kim, Dong Woon; Lee, Chang-Min; Jeong, Jin-Woo; Biochemistry and Molecular Biology, School of Medicine
    Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic steatohepatitis (NASH), affects 25% of the global population. Despite the prevalence of NAFLD worldwide, effective therapeutics are currently lacking. Amomum villosum var. xanthioides (Wall. ex Baker) T.L.Wu & S.J.Chen (AX) is a medicinal herb traditionally used for treating digestive tract disorders in countries across Asia. We aimed to examine the pharmacological effects of the ethyl acetate fraction of AX (AXEF) against tunicamycin (TM)-induced ER stress in a NASH mouse model using C57/BL6J male mice. Following TM injections (2 mg/kg), the mice were orally administrated AXEF (12.5, 25, or 50 mg/kg), silymarin (50 mg/kg), or distilled water daily for 5 days, and the outcomes for fatty liver, inflammation, and oxidative stress were measured in serum or liver tissue levels. AXEF drastically attenuated hepatic ER stress-induced NASH as indicated by decreases in lipid droplet accumulations, serum liver enzymes, hepatic inflammations, and cell death signals in the hepatic tissue and/or serum levels. Interestingly, AXEF showed potent antioxidant effects by quenching reactive oxidative stress and its final product lipid peroxide in the hepatic tissue, specifically an increase in metallothionein (MT). To confirm the underlying actions of AXEF, we observed that AXEF increases MT1 gene promoter activities in the physiological levels. Collectively, AXEF showed antioxidant properties on TM-induced ER stress in a NASH mice model through the improvement of MTs.
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    Relationship Between Three Commonly Used Non-invasive Fibrosis Biomarkers and Improvement in Fibrosis Stage in Patients With NASH
    (Wiley, 2019-02-21) Chalasani, Naga; Abdelmalek, Manal F.; Loomba, Rohit; Kowdley, Kris V.; McCullough, Arthur J.; Dasarathy, Srinivasan; Neuschwander-Tetri, Brent A.; Terrault, Norah; Ferguson, Beatrice; Shringarpure, Reshma; Shapiro, David; Sanyal, Arun J.; Medicine, School of Medicine
    Non-invasive biomarkers are needed for monitoring changes in liver histology in patients with non-alcoholic steatohepatitis (NASH). Obeticholic acid (OCA) was shown to improve fibrosis in patients with NASH in the FLINT trial; a post hoc analysis of these data was performed to determine the relationship between 3 non-invasive fibrosis markers and liver fibrosis improvement. Methods In the Phase 2b FLINT trial, patients were randomised (1:1) to receive 25 mg OCA or placebo once daily for 72 weeks. Aspartate aminotransferase:platelet ratio index (APRI), fibrosis-4 (FIB-4) index, and non-alcoholic fatty liver disease fibrosis score (NFS) were evaluated in serum at baseline and weeks 24, 48, 72, and 96. Liver biopsies were obtained at baseline and 72 weeks. Results In patients with fibrosis improvement at week 24, scores were reduced by a median of 34% for APRI, 10% for FIB-4, and 4% for NFS. Reductions in APRI (p=0.015) and FIB-4 (p=0.036), but not NFS (p=0.201) at week 24, significantly correlated with ≥1-stage improvement in histologic fibrosis at week 72. Reductions in APRI at week 72 were significantly correlated with fibrosis improvement at week 72 (p=0.012). Patients receiving OCA had significant reductions in all markers compared with patients receiving placebo at week 72 [APRI and FIB-4 (p<0.0001); NFS (p<0.05)]. Conclusions Readily available non-invasive markers may predict improvement in liver fibrosis in patients with NASH. Upon external confirmation and further refinement in larger populations, these markers may serve as surrogate end points in NASH clinical trials.