| First Author | Gavito AL | Year | 2016 |
| Journal | Br J Pharmacol | Volume | 173 |
| Issue | 6 | Pages | 1070-84 |
| PubMed ID | 26750868 | Mgi Jnum | J:318314 |
| Mgi Id | MGI:6859179 | Doi | 10.1111/bph.13423 |
| Citation | Gavito AL, et al. (2016) Single administration of recombinant IL-6 restores the gene expression of lipogenic enzymes in liver of fasting IL-6-deficient mice. Br J Pharmacol 173(6):1070-84 |
| abstractText | BACKGROUND AND PURPOSE: Lipogenesis is intimately controlled by hormones and cytokines as well as nutritional conditions. IL-6 participates in the regulation of fatty acid metabolism in the liver. We investigated the role of IL-6 in mediating fasting/re-feeding changes in the expression of hepatic lipogenic enzymes. EXPERIMENTAL APPROACH: Gene and protein expression of lipogenic enzymes were examined in livers of wild-type (WT) and IL-6-deficient (IL-6(-/-) ) mice during fasting and re-feeding conditions. Effects of exogenous IL-6 administration on gene expression of these enzymes were evaluated in vivo. The involvement of STAT3 in mediating these IL-6 responses was investigated by using siRNA in human HepG2 cells. KEY RESULTS: During feeding, the up-regulation in the hepatic expression of lipogenic genes presented similar time kinetics in WT and IL-6(-/-) mice. During fasting, expression of lipogenic genes decreased gradually over time in both strains, although the initial drop was more marked in IL-6(-/-) mice. Protein levels of hepatic lipogenic enzymes were lower in IL-6(-/-) than in WT mice at the end of the fasting period. In WT, circulating IL-6 levels paralleled gene expression of hepatic lipogenic enzymes. IL-6 administration in vivo and in vitro showed that IL-6-mediated signalling was associated with the up-regulation of hepatic lipogenic enzyme genes. Moreover, silencing STAT3 in HepG2 cells attenuated IL-6 mediated up-regulation of lipogenic gene transcription levels. CONCLUSIONS AND IMPLICATIONS: IL-6 sustains levels of hepatic lipogenic enzymes during fasting through activation of STAT3. Our findings indicate that clinical use of STAT3-associated signalling cytokines, particularly against steatosis, should be undertaken with caution. |
