caa a22 4500 605543720 CHVBK 20210128100928.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s00109-015-1310-2 doi (NATIONALLICENCE)springer-10.1007/s00109-015-1310-2 Lipid-mediated muscle insulin resistance: different fat, different pathways? [Elektronische Daten] [Olesja Ritter, Tomas Jelenik, Michael Roden] Increased dietary fat intake and lipolysis result in excessive lipid availability, which relates to impaired insulin sensitivity. Over the last years, several mechanisms possibly underlying lipid-mediated insulin resistance evolved. Lipid intermediates such as diacylglycerols (DAG) associate with changes in insulin sensitivity in many models. DAG activate novel protein kinase C (PKC) isoforms followed by inhibitory serine phosphorylation of insulin receptor substrate 1 (IRS1). Activation of Toll-like receptor 4 (TLR4) raises another lipid class, ceramides (CER), which induce pro-inflammatory pathways and lead to inhibition of Akt phosphorylation. Inhibition of glucosylceramide and ganglioside synthesis results in improved insulin sensitivity and increased activatory tyrosine phosphorylation of IRS1 in the muscle. Incomplete fat oxidation can increase acylcarnitines (ACC), which in turn stimulate pro-inflammatory pathways. This review analyzed the effects of lipid metabolites on insulin action in skeletal muscle of humans and rodents. Despite the evidence for the association of both DAG and CER with insulin resistance, its causal relevance may differ depending on the subcellular localization and the tested cohorts, e.g., athletes. Nevertheless, recent data indicate that individual lipid species and their degree of fatty acid saturation, particularly membrane and cytosolic C18:2 DAG, specifically activate PKCθ and induce both acute lipid-induced and chronic insulin resistance in humans. Springer-Verlag Berlin Heidelberg, 2015 Free fatty acids nationallicence Diacylglycerols nationallicence Sphingomyelines nationallicence Acylcarnitines nationallicence Insulin sensitivity nationallicence Ritter Olesja Institute for Clinical Diabetology, German Diabetes Center, c/o Auf'm Hennekamp 65, D-40225, Düsseldorf, Germany aut Jelenik Tomas Institute for Clinical Diabetology, German Diabetes Center, c/o Auf'm Hennekamp 65, D-40225, Düsseldorf, Germany aut Roden Michael Institute for Clinical Diabetology, German Diabetes Center, c/o Auf'm Hennekamp 65, D-40225, Düsseldorf, Germany aut Journal of Molecular Medicine Springer Berlin Heidelberg 93/8(2015-08-01), 831-843 0946-2716 93:8<831 2015 93 109 https://doi.org/10.1007/s00109-015-1310-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 review-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00109-015-1310-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ritter Olesja Institute for Clinical Diabetology, German Diabetes Center, c/o Auf'm Hennekamp 65, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 700 1- Jelenik Tomas Institute for Clinical Diabetology, German Diabetes Center, c/o Auf'm Hennekamp 65, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 700 1- Roden Michael Institute for Clinical Diabetology, German Diabetes Center, c/o Auf'm Hennekamp 65, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 773 0- Journal of Molecular Medicine Springer Berlin Heidelberg 93/8(2015-08-01), 831-843 0946-2716 93:8<831 2015 93 109