Browsing by Author "Ross, Ruth A."
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Item Activation of carbohydrate response element binding protein (ChREBP) by ethanol(Sage, 2013) Liangpunsakul, Suthat; Ross, Ruth A.; Crabb, David W.; Medicine, School of MedicineObjective: Carbohydrate response element-binding protein (ChREBP) is a transcription factor involved in hepatic lipogenesis. Its function is in part under the control of AMP-activated protein kinase (AMPK) and protein phosphatase 2A (PP2A). Given known effects of ethanol on AMPK and PP2A, it is plausible that ethanol might enhance fatty acid synthesis by increasing the activity of ChREBP. We hypothesized that another potential pathway of ethanol-induced hepatic steatosis is mediated by activation of ChREBP. Methods: The effects of ethanol on ChREBP were assessed in hepatoma cells and in C57BL/6J mice fed with the Lieber-DeCarli diet. Results: When the cells were exposed to ethanol (50 mM) for 24 hours, the activity of a liver pyruvate kinase (LPK) promoter-luciferase reporter was increased by ∼4-fold. Ethanol feeding of mice resulted in the translocation of ChREBP from cytosol to the nucleus. Protein phosphatase 2A activity was increased in the liver of ethanol-fed mice by 22%. We found no difference in the levels of hepatic Xu-5-P between ethanol-fed mice and controls. Transfection of a constitutively active AMPK expression plasmid suppressed the basal activity of the LPK luciferase reporter and abolished the effect of ethanol on the reporter activity. However, transfection of rat hepatoma cells with a dominant-negative AMPK expression plasmid induced basal LPK luciferase activity by only ∼20%. The effect of ethanol on ChREBP was attenuated in the presence of okadaic acid, an inhibitor of PP2A. Conclusions: The effects of ethanol on AMPK and PP2A may result in activation of ChREBP, providing another potential mechanism for ethanol-induced hepatic steatosis. However, additional okadaic acid-insensitive effects appear to be important as well.Item Disturbances in the murine hepatic circadian clock in alcohol-induced hepatic steatosis(Springer Nature, 2014-01-16) Zhou, Peng; Ross, Ruth A.; Pywell, Cameron M.; Liangpunsakul, Suthat; Duffield, Giles E.; Medicine, School of MedicineTo investigate the role of the circadian clock in the development of alcohol-induced fatty liver disease we examined livers of mice chronically alcohol-fed over 4-weeks that resulted in steatosis. Here we show time-of-day specific changes in expression of clock genes and clock-controlled genes, including those associated with lipid and bile acid regulation. Such changes were not observed following a 1-week alcohol treatment with no hepatic lipid accumulation. Real-time bioluminescence reporting of PERIOD2 protein expression suggests that these changes occur independently of the suprachiasmatic nucleus pacemaker. Further, we find profound time-of-day specific changes to the rhythmic synthesis/accumulation of triglycerides, cholesterol and bile acid, and the NAD/NADH ratio, processes that are under clock control. These results highlight not only that the circadian timekeeping system is disturbed in the alcohol-induced hepatic steatosis state, but also that the effects of alcohol upon the clock itself may actually contribute to the development of hepatic steatosis.Item Increasing serum pre-adipocyte factor-1 (Pref-1) correlates with decreased body fat, increased free fatty acids, and level of recent alcohol consumption in excessive alcohol drinkers(Elsevier, 2014-12) Liangpunsakul, Suthat; Bennett, Rachel; Westerhold, Chi; Ross, Ruth A.; Crabb, David W.; Lai, Xianyin; Witzmann, Frank A.; Department of Medicine, IU School of MedicinePatients with alcoholic liver disease have been reported to have a significantly lower percentage of body fat (%BF) than controls. The mechanism for the reduction in %BF in heavy alcohol users has not been elucidated. In adipose tissue, Pref-1 is specifically expressed in pre-adipocytes but not in adipocytes. Pref-1 inhibits adipogenesis and elevated levels are associated with reduced adipose tissue mass. We investigated the association between serum Pref-1 and %BF, alcohol consumption, and serum free fatty acids (FFA) in a well-characterized cohort of heavy alcohol users compared to controls. One hundred forty-eight subjects were prospectively recruited. The Time Line Follow-Back (TLFB) questionnaire was used to quantify the amount of alcohol consumed over the 30-day period before their enrollment. Anthropometric measurements were performed to calculate %BF. Serum Pref-1 and FFA were measured. Fifty-one subjects (mean age 32 ± 9 years, 88% men) were non-excessive drinkers whereas 97 were excessive drinkers (mean age 41 ± 18 years, 69% men). Compared to non-excessive drinkers, individuals with excessive drinking had significantly higher levels of Pref-1 (p<0.01), FFA (p < 0.001), and lower %BF (p = 0.03). Serum levels of Pref-1 were associated with the amount of alcohol consumed during the previous 30 days. Serum Pref-1 was negatively correlated with %BF, but positively associated with serum FFA. Our data suggest that elevated Pref-1 levels in excessive drinkers might inhibit the expansion of adipose tissue, decreasing %BF in alcoholics. Further work is needed to validate these findings and to better understand the role of Pref-1 and its clinical significance in subjects with heavy alcohol use.Item LncRNA AK054921 and AK128652 are potential serum biomarkers and predictors of patient survival with alcoholic cirrhosis(Wiley, 2017-08) Yang, Zhihong; Ross, Ruth A.; Zhao, Shi; Tu, Wanzhu; Liangpunsakul, Suthat; Wang, Li; Medicine, School of MedicineBackground: Alcoholic liver disease (ALD) is one of the leading causes of chronic liver disease. Recent studies have demonstrated the roles of long noncoding RNAs (lncRNAs) in the pathogenesis of several disease processes. However, the roles of lncRNAs in patients with ALD remain unexplored. Methods: Global profiling for human lncRNAs from peripheral blood RNA was performed in a well characterized cohort of healthy controls (HC, n=4), excessive drinkers without liver diseases (ED, n=4), and those with alcoholic cirrhosis with different severities (AC, n=12). The expression of unique lncRNA signatures were validated in a separate cohort of HC (n=17), ED (n=19), AC (n=48), and human liver tissues with ALD (n=19). Results: Detailed analysis of plasma lncRNAs in AC subjects with different severities compared to HC identified 244 commonly up-regulated lncRNAs and 181 commonly down-regulated lncRNAs. We further validated top 20 most differentially up- and down-regulated lncRNAs in ED and AC as compared to HC and also determined the expression of selected lncRNAs in human liver tissues with or without AC. Among those lncRNAs, AK128652 and AK054921 were two of the most abundantly expressed lncRNAs in normal human plasma and liver, and their levels were significantly elevated in AC. The prognostic significance of AK128652 and AK054921 was determined in 48 subjects with AC; who were prospectively followed for 520 days. The expression of AK128652 and AK054921 was inversely associated with survival in patients with AC. Conclusions: LncRNAs AK054921 and AK128652 are potential biomarkers to predict the progression to ALD in those with excessive alcohol consumption and are predictors of survival with patients with alcoholic cirrhosis.Item MicroRNA-223 ameliorates alcoholic liver injury by inhibiting the IL-6–p47phox–oxidative stress pathway in neutrophils(BMJ, 2017-04) Li, Man; He, Yong; Zhou, Zhou; Ramirez, Teresa; Gao, Yueqiu; Gao, Yanhang; Ross, Ruth A.; Cao, Haixia; Cai, Yan; Xu, Mingjiang; Feng, Dechun; Zhang, Ping; Liangpunsakul, Suthat; Gao, Bin; Department of Medicine, IU School of MedicineObjectives Chronic-plus-binge ethanol feeding activates neutrophils and exacerbates liver injury in mice. This study investigates how recent excessive drinking affects peripheral neutrophils and liver injury in alcoholics, and how miR-223, one of the most abundant microRNAs (miRNAs) in neutrophils, modulates neutrophil function and liver injury in ethanol-fed mice. Designs Three hundred alcoholics with (n=140) or without (n=160) recent excessive drinking and 45 healthy controls were enrolled. Mice were fed an ethanol diet for 10 days followed by a single binge of ethanol. Results Compared with healthy controls or alcoholics without recent drinking, alcoholics with recent excessive drinking had higher levels of circulating neutrophils, which correlated with serum levels of alanine transaminase (ALT) and aspartate transaminase (AST). miRNA array analysis revealed that alcoholics had elevated serum miR-223 levels compared with healthy controls. In chronic-plus-binge ethanol feeding mouse model, the levels of miR-223 were increased in both serum and neutrophils. Genetic deletion of the miR-223 gene exacerbated ethanol-induced hepatic injury, neutrophil infiltration, reactive oxygen species (ROS) and upregulated hepatic expression of interleukin (IL)-6 and phagocytic oxidase (phox) p47phox. Mechanistic studies revealed that miR-223 directly inhibited IL-6 expression and subsequently inhibited p47phox expression in neutrophils. Deletion of the p47phox gene ameliorated ethanol-induced liver injury and ROS production by neutrophils. Finally, miR-223 expression was downregulated, while IL-6 and p47phox expression were upregulated in peripheral blood neutrophils from alcoholics compared with healthy controls. Conclusions miR-223 is an important regulator to block neutrophil infiltration in alcoholic liver disease and could be a novel therapeutic target for the treatment of this malady.Item Mitochondrial DNA-enriched microparticles promote acute-on-chronic alcoholic neutrophilia and hepatotoxicity(American Society for Clinical Investigation, 2017-07-20) Cai, Yan; Xu, Ming-Jiang; Koritzinsky, Erik H.; Zhou, Zhou; Wang, Wei; Cao, Haixia; Yuen, Peter S.T.; Ross, Ruth A.; Star, Robert A.; Liangpunsaku, Suthat; Gao, Bin; Medicine, School of MedicineOver the last several years, one of the major advances in the field of alcoholic liver disease research was the discovery that binge alcohol consumption induced neutrophilia and hepatic neutrophil infiltration in chronically ethanol-fed mice and human subjects with excessive alcohol use (EAU); however, the underlying mechanisms remain obscure. Here, we demonstrated that chronic EAU patients with a history of recent excessive drinking (EAU + RD) had higher serum levels of mitochondrial DNA (mtDNA)-enriched microparticles (MPs) than EAU without recent drinking (EAU - RD) and healthy controls, which correlated positively with circulating neutrophils. Similarly, mice with chronic-plus-binge (E10d + 1B) ethanol feeding also had markedly elevated serum levels of mtDNA-enriched MPs, with activation of hepatic ER stress and inflammatory responses. Inhibition of ER stress by gene KO or inhibitors attenuated ethanol-induced elevation of mtDNA-enriched MPs, neutrophilia, and liver injury. The data from the study of hepatocyte-specific deletion of the protein kinase RNA-like ER kinase (Perk) gene in mice and of cultured hepatocytes demonstrated that hepatocytes were the main source of mtDNA-enriched MPs after ethanol feeding. Finally, administration of mtDNA-enriched MPs isolated from E10d+1B-fed mice caused neutrophilia in mice. In conclusion, E10d + 1B ethanol consumption activates hepatic ER stress-dependent mtDNA-enriched MP release, leading to neutrophilia and liver injury.Item Quantity of alcohol drinking positively correlates with serum levels of endotoxin and markers of monocyte activation(Nature Publishing Group, 2017-06-30) Liangpunsakul, Suthat; Toh, Evelyn; Ross, Ruth A.; Heathers, Laura E.; Chandler, Kristina; Oshodi, AdePeju; McGee, Breann; Modlik, Elizabeth; Linton, Tobyn; Mangiacarne, Darrin; Jimenez, Claudie; Dong, X. Charlie; Wang, Li; Tu, Wanzhu; Nelson, David E.; Medicine, School of MedicineIt is unknown if LPS (lipopolysaccharides) and markers of immune activation, soluble CD14 (sCD14) and CD163 (sCD163) are associated with the quantity of alcohol consumption. 148 subjects were enrolled (97 excessive drinkers (ED) and 51 controls). Time Line Follow-Back questionnaire was used to quantify the amount of alcohol consumed. Serum LPS, sCD14, and sCD163 were measured. Peripheral blood mononuclear cells (PBMCs) were also isolated. Compared to controls, ED had higher total drinks in the past 30 days, higher levels of LPS, sCD14 and sCD163. The levels of serum LPS, sCD14, and sCD163 were higher among ED with recent alcohol consumption (last drink <10 days before enrollment) compared to those without recent drinking. Similar bacterial genome copy numbers were detected in control and ED groups. We found that ethanol primed PBMCs for LPS-induced inflammatory responses. A positive correlation between serum LPS, sCD14, sCD163 and the quantity of alcohol drinking was observed after adjusting for covariates and that abstinence was associated with decline in the levels of LPS, sCD14 and sCd163. We found an increase in the levels of LPS and markers of monocyte activations in ED. Further studies are needed to determine whether these can be used as the biomarkers for excessive alcohol use.Item Serum Metabolomic Profiling Identifies Key Metabolic Signatures Associated With Pathogenesis of Alcoholic Liver Disease in Humans(Wiley, 2019-02-20) Yang, Zhihong; Kusumanchi, Praveen; Ross, Ruth A.; Heathers, Laura; Chandler, Kristina; Oshodi, Adepeju; Thoudam, Themis; Li, Feng; Wang, Li; Liangpunsakul, Suthat; Medicine, School of MedicineAlcoholic liver disease (ALD) develops in a subset of heavy drinkers (HDs). The goals of our study were to (1) characterize the global serum metabolomic changes in well-characterized cohorts of controls (Cs), HDs, and those with alcoholic cirrhosis (AC); (2) identify metabolomic signatures as potential diagnostic markers, and (3) determine the trajectory of serum metabolites in response to alcohol abstinence. Serum metabolic profiling was performed in 22 Cs, 147 HDs, and 33 patients with AC using ultraperformance liquid chromatography-tandem mass spectrometry. Hepatic gene expression was conducted in Cs (n = 16) and those with AC (n = 32). We found progressive changes in the quantities of metabolites from heavy drinking to AC. Taurine-conjugated bile acids (taurocholic acid [TCA], 127-fold; taurochenodeoxycholic acid [TCDCA], 131-fold; and tauroursodeoxycholic acid, 56-fold) showed more striking elevations than glycine-conjugated forms (glycocholic acid [GCA], 22-fold; glycochenodeoxycholic acid [GCDCA], 22-fold; and glycoursodeoxycholic acid [GUDCA], 11-fold). This was associated with increased liver cytochrome P450, family 7, subfamily B, member 1 and taurine content (more substrates); the latter was due to dysregulation of homocysteine metabolism. Increased levels of GCDCA, TCDCA, GCA, and TCA positively correlated with disease progression from Child-Pugh A to C and Model for End-Stage Liver Disease scores, whereas GCDCA, GCA, and GUDCA were better predictors of alcohol abstinence. The levels of glucagon-like peptide 1 (GLP-1) and fibroblast growth factor (FGF) 21 but not FGF19 were increased in HDs, and all three were further increased in those with AC. Conclusion: Serum taurine/glycine-conjugated bile acids could serve as noninvasive markers to predict the severity of AC, whereas GLP-1 and FGF21 may indicate a progression from heavy drinking to AC.