The CDP-ethanolamine pathway regulates skeletal muscle diacylglycerol content and mitochondrial biogenesis without altering insulin sensitivity

Ahrathy Selathurai, Greg M Kowalski, Micah L Burch, Patricio V Sepulveda, Steve Risis, Robert S Lee-Young, Severine Lamon, Peter J Meikle, Amanda J Genders, Sean L McGee, Matthew J Watt, Aaron Paul Russell, Matthew Frank, Suzanne Jackowski, Mark A Febbraio, Clinton R Bruce

Research output: Contribution to journalArticleResearchpeer-review

48 Citations (Scopus)

Abstract

Accumulation of diacylglycerol (DG) in muscle is thought to cause insulin resistance. DG is a precursor for phospholipids, thus phospholipid synthesis could be involved in regulating muscle DG. Little is known about the interaction between phospholipid and DG in muscle; therefore, we examined whether disrupting muscle phospholipid synthesis, specifically phosphatidylethanolamine (PtdEtn), would influence muscle DG content and insulin sensitivity. Muscle PtdEtn synthesis was disrupted by deleting CTP:phosphoethanolamine cytidylyltransferase (ECT), the rate-limiting enzyme in the CDP-ethanolamine pathway, a major route for PtdEtn production. While PtdEtn was reduced in muscle-specific ECT knockout mice, intramyocellular and membrane-associated DG was markedly increased. Importantly, however, this was not associated with insulin resistance. Unexpectedly, mitochondrial biogenesis and muscle oxidative capacity were increased in muscle-specific ECT knockout mice and were accompanied by enhanced exercise performance. These findings highlight the importance of the CDP-ethanolamine pathway in regulating muscle DG content and challenge the DG-induced insulin resistance hypothesis.
Original languageEnglish
Pages (from-to)718 - 730
Number of pages13
JournalCell Metabolism
Volume21
Issue number5
DOIs
Publication statusPublished - 2015

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