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Angiopoietin-like protein 8 (ANGPTL8)/betatrophin expression in visceral adipose tissue and associations with circulating fatty acid profile have not yet been investigated. Forty subjects were included in a cross-sectional study, 57 in a dietary weight reduction intervention. Circulating Angiopoietin-like protein 8/betatrophin was measured in all subjects. Liver and adipose tissue were sampled and plasma fatty acids and tissue Angiopoietin-like protein 8/betatrophin expression were evaluated in the cross-sectional study. In the intervention study oral glucose testing and liver magnetic resonance scanning at baseline and after 6 months were performed. Angiopoietin-like protein 8/betatrophin mRNA was increased in visceral compared to subcutaneous adipose tissue (p < 0.001). Circulating ANGPTL8/betatrophin correlated with liver steatosis (r = 0.42, p = 0.047), triacylglycerols (r = 0.34, p = 0.046), saturated (r = 0.43, p = 0.022), monounsaturated (r = 0.51, p = 0.007), and polyunsaturated fatty acids (r = - 0.53, p = 0.004). In the intervention study, baseline Angiopoietin-like protein 8/betatrophin correlated with age (r = 0.32, p = 0.010) and triacylglycerols (r = 0.30, p = 0.02) and was increased with hepatic steatosis (p = 0.033). Weight loss reduced liver fat by 45% and circulating Angiopoietin-like protein 8/betatrophin by 11% (288 ± 17 vs. 258 ± 17 pg/ml; p = 0.015). Angiopoietin-like protein 8/betatrophin is related to liver steatosis, while visceral adipose tissue represents an additional site of expression in humans. [ABSTRACT FROM AUTHOR]

5′AMP-activated protein kinase (AMPK) is known as metabolic sensor in mammalian cells that becomes activated by an increasing adenosine monophosphate (AMP)/adenosine triphosphate (ATP) ratio. The heterotrimeric AMPK protein comprises three subunits, each of which has multiple phosphorylation sites, playing an important role in the regulation of essential molecular pathways. By phosphorylation of downstream proteins and modulation of gene transcription AMPK functions as a master switch of energy homeostasis in tissues with high metabolic turnover, such as the liver, skeletal muscle, and adipose tissue. Regulation of AMPK under conditions of chronic caloric oversupply emerged as substantial research target to get deeper insight into the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Evidence supporting the role of AMPK in NAFLD is mainly derived from preclinical cell culture and animal studies. Dysbalanced de novo lipogenesis has been identified as one of the key processes in NAFLD pathogenesis. Thus, the scope of this review is to provide an integrative overview of evidence, in particular from clinical studies and human samples, on the role of AMPK in the regulation of primarily de novo lipogenesis in human NAFLD. [ABSTRACT FROM AUTHOR]