Phosphatidylcholine homeostasis and liver failure.
Article Details
- CitationCopy to clipboard
Li Z, Agellon LB, Vance DE
Phosphatidylcholine homeostasis and liver failure.
J Biol Chem. 2005 Nov 11;280(45):37798-802. Epub 2005 Sep 6.
- PubMed ID
- 16144842 [ View in PubMed]
- Abstract
In mammals, the only endogenous pathway for choline biosynthesis is the methylation of phosphatidylethanolamine to phosphatidylcholine (PC) by phosphatidylethanolamine N-methyltransferase (PEMT) coupled to PC degradation. Complete choline deprivation in mice by feeding Pemt(-/-) mice a choline-deficient (CD) diet decreases hepatic PC by 50% and is lethal within 5 days. PC secretion into bile is mediated by a PC-specific flippase, multiple drug-resistant protein 2 (MDR2). Here, we report that mice that lack both PEMT and MDR2 and are fed a CD diet survive for >90 days. Unexpectedly, the amount of PC also decreases by 50% in the livers of Mdr2(-/-)/Pemt(-/-) mice. The Mdr2(-/-)/Pemt(-/-) mice adapt to the severe choline deprivation via choline recycling by induction of phospholipase A(2), choline kinase, and CTP:phosphocholine cytidylyltransferase activities and by a strikingly decreased expression of choline oxidase. The ability of Mdr2(-/-)/Pemt(-/-) mice to survive complete choline deprivation suggests that acute lethality in CD-Pemt(-/-) mice results from rapid depletion of hepatic PC via biliary secretion.
DrugBank Data that Cites this Article
- Drug Enzymes
Drug Enzyme Kind Organism Pharmacological Action Actions Choline Choline kinase alpha Protein Humans UnknownSubstrateDetails Choline salicylate Choline kinase alpha Protein Humans UnknownSubstrateDetails