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Background & AimsAdipose tissue (AT)-derived fatty acids (FAs) are utilized for hepatic triacylglycerol (TG) generation upon fasting. However, their potential impact as signaling molecules is not established. Herein we examined the role of exogenous AT-derived FAs in the regulation of hepatic gene expression by investigating mice with a defect in AT-derived FA supply to the liver.MethodsPlasma FA levels, tissue TG hydrolytic activities and lipid content were determined in mice lacking the lipase co-activator comparative gene identification-58 (CGI-58) selectively in AT (CGI-58-ATko) applying standard protocols. Hepatic expression of lipases, FA oxidative genes, transcription factors, ER stress markers, hormones and cytokines were determined by qRT-PCR, Western blotting and ELISA.ResultsImpaired AT-derived FA supply upon fasting of CGI-58-ATko mice causes a marked defect in liver PPARα-signaling and nuclear CREBH translocation. This severely reduced the expression of respective target genes such as the ATGL inhibitor G0/G1 switch gene-2 (G0S2) and the endocrine metabolic regulator FGF21. These changes could be reversed by lipid administration and raising plasma FA levels. Impaired AT-lipolysis failed to induce hepatic G0S2 expression in fasted CGI-58-ATko mice leading to enhanced ATGL-mediated TG-breakdown strongly reducing hepatic TG deposition. On high fat diet, impaired AT-lipolysis counteracts hepatic TG accumulation and liver stress linked to improved systemic insulin sensitivity.ConclusionsAT-derived FAs are a critical regulator of hepatic fasting gene expression required for the induction of G0S2-expression in the liver to control hepatic TG-breakdown. Interfering with AT-lipolysis or hepatic G0S2 expression represents an effective strategy for the treatment of hepatic steatosis.

In 1955, a paradigm shift in the conception of sex is said to have taken place, when psychologist John Money at Johns Hopkins's Pediatric Endocrinology Clinic argued that 'hermaphroditic' children could be assigned a sex contradictory to their biological sex. Rather than being born male or female, he claimed, these children learned to be boys or girls. Money was subsequently credited the invention of the term gender role. However, Money only confirmed a practice that was established at the clinic several years before his intervention. The clinic's director Lawson Wilkins (1894-1963) had already recommended that certain children, virilized by congenital adrenal hyperplasia, should be raised in the male sex, even though they were by all medical standards of the time female. What mattered for him was assigning the sex that seemed 'better' for these children. What constituted the 'better sex' was contingent on the child's psyche and habitus, social expectations, and on the range of medical and surgical interventions available at the time.