Uptake and utilization of arachidonic acid in infective larvae ofAngiostrongylus cantonensis

Abstract

Infective larvae of Angiostrongylus cantonensis may take up and incorporate exogenous arachidonic acid into their lipid pool. By scintillation counting, uptake and incorporation were determined to be time dependent. Arachidonic acid was mainly incorporated into phospholipid (56.8%) and neutral lipid (22.4%) pools. In the neutral lipids, 64.0% was diglyceride and 36.0% triglyceride. Phosphatidylcholine was the predominant fatty acid in the phospholipid pool. In addition to the release of leukotriene B4, the parasite was found to generate radiolabelled CO2 after incubation with [U-14C]arachidonate. Moreover, enzymatic analysis of crude extracts revealed the presence of acyl-CoA dehydrogenase (short and long chain), thiolase, enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase. These findings suggest that infective larvae of A. cantonensis not only take up and incorporate exogenous arachidonic acid into their lipid pool, but may also utilize the fatty acid through a functional β-oxidation pathway.

Expression and Characterization of α-Methylacyl CoA Racemase from Anisakis simplex Larvae

“…However, the β-oxidation of fatty acids has not been reported in adult or larval helminths due to their anaerobic condition within the host even though the genes for the TCA cycle are present in several nematodes [22,23]. Recently, the oxidization of fatty acids and the activity of fatty acid oxidation enzymes were confirmed in infective larvae of Angiostrongylus cantonensis [24]. The uptake of arachidonic acid by A. cantonensis and the presence of oxidation enzymes strongly suggest that some nematodes can use the β-oxidation pathway.…”