ABSTRACT
Common genetic variants in glucokinase regulator (GCKR), which encodes GKRP, a regulator of hepatic glucokinase (GCK), influence multiple metabolic traits in genome-wide association studies (GWASs), making GCKR one of the most pleiotropic GWAS loci in the genome. It is unclear why. Prior work has demonstrated that GCKR influences the hepatic cytosolic NADH/NAD+ ratio, also referred to as reductive stress. Here, we demonstrate that reductive stress is sufficient to activate the transcription factor ChREBP and necessary for its activation by the GKRP-GCK interaction, glucose, and ethanol. We show that hepatic reductive stress induces GCKR GWAS traits such as increased hepatic fat, circulating FGF21, and circulating acylglycerol species, which are also influenced by ChREBP. We define the transcriptional signature of hepatic reductive stress and show its upregulation in fatty liver disease and downregulation after bariatric surgery in humans. These findings highlight how a GCKR-reductive stress-ChREBP axis influences multiple human metabolic traits.
Subject(s)
Genome-Wide Association Study , Glucokinase , Humans , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Glucokinase/genetics , Glucokinase/metabolism , Glucose/metabolism , Liver/metabolism , Transcription Factors/metabolismABSTRACT
Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in persons with HIV (PWH) (HIV-NAFLD). It is unknown if HIV-NAFLD is associated with impairment in health-related quality of life (HRQOL). We examined HRQOL in PWH with and without NAFLD, compared HRQOL in HIV- versus primary NAFLD, and determined factors associated with HRQOL in these groups. Prospectively enrolled 200 PWH and 474 participants with primary NAFLD completed the Rand SF-36 assessment which measures 8 domains of HRQOL. Individual domain scores were used to create composite physical and mental component summary scores. Univariate and multivariate analyses determined variables associated with HRQOL in PWH and in HIV- and primary NAFLD. In PWH, 48% had HIV-NAFLD, 10.2% had clinically significant fibrosis, 99.5% were on antiretroviral therapy, and 96.5% had HIV RNA <200 copies/ml. There was no difference in HRQOL in PWH with or without NAFLD. Diabetes, non-Hispanic ethnicity, and nadir CD4 counts were independently associated with impaired HRQOL in PWH. In HIV-NAFLD, HRQOL did not differ between participants with or without clinically significant fibrosis. Participants with HIV-NAFLD compared to those with primary NAFLD were less frequently cisgender females, White, more frequently Hispanic, had lower BMI and lower frequency of obesity and diabetes. HRQOL of individuals with HIV-NAFLD was not significantly different from those with primary NAFLD. In conclusion, in virally suppressed PWH, HRQOL is not different between participants with or without HIV-NAFLD. HRQOL is not different between HIV-NAFLD and primary NAFLD.
Subject(s)
Diabetes Mellitus , HIV Infections , Non-alcoholic Fatty Liver Disease , Female , Humans , Non-alcoholic Fatty Liver Disease/complications , Quality of Life , HIV Infections/complications , HIV Infections/drug therapy , HIV , FibrosisABSTRACT
BACKGROUND AIMS: The current prevalence of fatty liver disease (FLD) due to alcohol-associated (AFLD) and nonalcoholic (NAFLD) origins in US persons with HIV (PWH) is not well defined. We prospectively evaluated the burden of FLD and hepatic fibrosis in a diverse cohort of PWH. APPROACH RESULTS: Consenting participants in outpatient HIV clinics in 3 centers in the US underwent detailed phenotyping, including liver ultrasound and vibration-controlled transient elastography for controlled attenuation parameter and liver stiffness measurement. The prevalence of AFLD, NAFLD, and clinically significant and advanced fibrosis was determined. Univariate and multivariate logistic regression models were used to evaluate factors associated with the risk of NAFLD. Of 342 participants, 95.6% were on antiretroviral therapy, 93.9% had adequate viral suppression, 48.7% (95% CI 43%-54%) had steatosis by ultrasound, and 50.6% (95% CI 45%-56%) had steatosis by controlled attenuation parameter ≥263 dB/m. NAFLD accounted for 90% of FLD. In multivariable analysis, old age, higher body mass index, diabetes, and higher alanine aminotransferase, but not antiretroviral therapy or CD4 + cell count, were independently associated with increased NAFLD risk. In all PWH with fatty liver, the frequency of liver stiffness measurement 8-12 kPa was 13.9% (95% CI 9%-20%) and ≥12 kPa 6.4% (95% CI 3%-11%), with a similar frequency of these liver stiffness measurement cutoffs in NAFLD. CONCLUSIONS: Nearly half of the virally-suppressed PWH have FLD, 90% of which is due to NAFLD. A fifth of the PWH with FLD has clinically significant fibrosis, and 6% have advanced fibrosis. These data lend support to systematic screening for high-risk NAFLD in PWH.
Subject(s)
Diabetes Mellitus , Elasticity Imaging Techniques , HIV Infections , Non-alcoholic Fatty Liver Disease , Humans , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/epidemiology , Non-alcoholic Fatty Liver Disease/pathology , Cross-Sectional Studies , Liver Cirrhosis/complications , HIV Infections/complications , HIV Infections/drug therapy , HIV Infections/pathology , Liver/diagnostic imaging , Liver/pathologySubject(s)
Eicosanoids/blood , Liver Cirrhosis/diagnosis , Non-alcoholic Fatty Liver Disease/diagnosis , Adult , Biomarkers/blood , Chromatography, High Pressure Liquid , Cross-Sectional Studies , Eicosanoids/isolation & purification , Female , Humans , Liver/pathology , Liver Cirrhosis/blood , Liver Cirrhosis/epidemiology , Liver Cirrhosis/pathology , Male , Middle Aged , Non-alcoholic Fatty Liver Disease/blood , Non-alcoholic Fatty Liver Disease/epidemiology , Non-alcoholic Fatty Liver Disease/pathology , Prevalence , Prospective Studies , Severity of Illness Index , Tandem Mass SpectrometryABSTRACT
To elucidate the extent to which DNA methylation varies across multiple tissues in the brain and between animals, we have quantified global DNA methylation in tissues comprising the limbic system for six Red Angus x Simmental steers. Global DNA methylation was measured in nine regions of the bovine brain: amygdala, the bed nucleus of the stria terminalis, cingulate gyrus, dorsal raphe, hippocampus, hypothalamus, nucleus accumbens, periaqueductal gray and prefrontal cortex. DNA methylation varies among animals for each tissue type and varies among tissue types for each animal. The highest amounts of DNA methylation were found in the amygdala, cingulate gyrus and dorsal raphe, while the bed nucleus of the stria terminalis, nucleus accumbens and periaqueductal gray had the lowest amounts of DNA methylation. A heatmap sorted by k-means clustering was generated to graphically display percent DNA methylation in relation to tissue type and animal number. This is the first study to report measures of DNA methylation in the limbic system of the bovine brain and can be used to inform the cattle genomics community of expected variation in cattle brain methylation.