Interleukin-1 beta-induced type IIA secreted phospholipase A(2) gene expression and extracellular activity in rat vascular endothelial cells

Two phospholipase A(2) (PLA(2)) isoforms, secretory and cytosolic, have bee n implicated in inflammation. Secretory type IIA PLA(2) (sPLA(2)-IIA), whic h hydrolyzes fatty acids bound at the sn-2 position of glycerophospholipids , has been detected universally in a variety of mammalian tissues and cells . The expression of the sPLA(2)-IIA gene and its extracellular activity wer e shown to be regulated by different factors such as hypoxia, cytokines and phorbol esters. In the present study, we examined the effects of interleuk in-1 beta (IL-1 beta) on the expression of the 14 kDa sPLA(2)-IIA, determin ed using reverse transcription polymerase chain reaction and radiometric Es cherichia coli enzyme assay in primary cultures of rat endothelial cells an d in two different rat endothelial cell lines (SVAREC and RBE4). These expe riments revealed that IL-1 beta induces sPLA(2)IIa gene expression and secr etion of the enzyme in endothelial cells in a dose- and time-dependent mann er. The cAMP-elevator forskolin did not augment the cytokine-induced elevat ion of sPLA(2)-IIa enzyme activity but significantly increased the IL-1 bet a -stimulated sPLA(2)-IIa mRNA contents in endothelial cells. (C) 2001 Harc ourt Publishers Ltd.