title: Ether--lipid (alkyl-phospholipid) metabolism and the mechanism of action of ether--lipid analogues in Leishmania.
abstract: Ether-lipid (alkyl-phospholipid) analogues such as Miltefosine possess potent in vitro and in vivo anti-leishmanial activity and these compounds are currently undergoing clinical trials in humans. These analogues are also effective against Trypanosoma cruzi and Trypanosoma brucei subspecies but their mode of action is not known. Leishmania have high levels of ether-lipids and these are mainly found in the glycosylphosphatidylinositol-anchored glycolipids and glycoproteins present on the surface of the parasites. In Leishmania mexicana promastigotes we have studied both the initiating steps for the biosynthesis of ether-lipids, and key remodelling steps. The effect of Miltefosine and Edelfosine, on key enzymes involved in the metabolism of ether-lipids has been studied. The enzymes include dihydroxyacetonephosphate acyltransferase, sn-l-acyl-2-lyso-glycero-3-phosphocholine and sn-l-alkyl-2-lyso-glycero-3-phosphocholine acyltransferases. We confirm that the initiating steps in ether-lipid metabolism in Leishmania are present in glycosomes, and that Miltefosine or Edelfosine did not perturb these enzymes. The metabolism of the latter phosphatidylcholine base intermediates, which may be involved in the remodelling of acyl- and alkyl-glycerophospholipids, was also seemingly associated with glycosomes. Both Miltefosine and Edelfosine inhibited this microbody (glycosomal) located alkyl-specific-acyl-CoA acyltransferase in a dose-dependent manner with an inhibitory concentration of 50 microM. It is suggested therefore that a perturbation of ether-lipid remodelling could be responsible for the anti-leishmanial action of these drugs.
authors.affiliation: Infection and Immunity Research Group, Division of Life Sciences, King's College London, London SEI 8WA, UK.
authors.forename: H
authors.initials: H
authors.lastname: Lux
authors.forename: N
authors.initials: N
authors.lastname: Heise
authors.forename: T
authors.initials: T
authors.lastname: Klenner
authors.forename: D
authors.initials: D
authors.lastname: Hart
authors.forename: F R
authors.initials: FR
authors.lastname: Opperdoes
mesh_terms: D000215:Acylation; D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism; D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D007894:Leishmania mexicana / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008830:Microbodies / Q000378:metabolism; D010742:Phospholipid Ethers / Q000378:metabolism* / Q000494:pharmacology*; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D000981:Antiprotozoal Agents; D010742:Phospholipid Ethers; D010767:Phosphorylcholine; C026659:edelfosine; C039128:miltefosine; D000429:Alcohol Oxidoreductases; D000217:Acyltransferases; C020051:glycerone-phosphate O-acyltransferase; D019883:Alkyl and Aryl Transferases; C019654:alkylglycerone-phosphate synthase