Possible roles of Phospholipase A2 in the biological activities of Acanthamoeba castellanii (T4 Genotype)
Mortazavi, Parisa Nakhostin and Keisary, E. and Loh, L.N. and Jung, S.Y. and Khan, Naveed Ahmed (2011) Possible roles of Phospholipase A2 in the biological activities of Acanthamoeba castellanii (T4 Genotype). Protist 162 (1), pp. 168-176. ISSN 1434-4610.
Using phospholipases A2-specific spectrophotometric assays, it was shown that A. castellanii lysates and their conditioned medium exhibit phospholipase activities. The extracellular levels of PLA2 detected were significantly reduced compared with the cell-associated enzyme (P<0.05). Sphinganine, a PLA2 inhibitor showed robust amoebistatic properties but had no effect on the viability of A. castellanii. The potency of sphinganine was demonstrated effectively towards purified PLA2 derived from porcine pancreas. Using sphinganine, it was observed that PLA2 is involved in neither binding nor cytotoxicity of the human brain microvascular endothelial cells due to A. castellanii. Unlike as was the case for Dictyostelium amoebae, PLA2 appeared to be involved in A. castellanii phagocytosis of the fluorescently-labelled polystyrene beads. Horseradish peroxidase was used as a tracer molecule to develop assays to study pinocytosis in A. castellanii. The findings revealed that sphinganine impedes phagocytosis but augments pinocytosis in A. castellanii suggesting distinct nature of processes. A complete understanding of the role of phospholipases in the biology and pathogenesis of A. castellanii infections will determine their potential as therapeutic targets.
|Keyword(s) / Subject(s):||Acanthamoeba castellanii, pathogenicity, phospholipase A2, phagocytosis, pinocytosis, sphinganine|
|School:||Birkbeck Schools and Departments > School of Science > Biological Sciences|
|Date Deposited:||27 Jul 2011 08:22|
|Last Modified:||17 Apr 2013 12:21|
Additional statistics are available via IRStats2.