Localization of various secretory phospholipase A2 enzymes in male reproductive organs.

Current evidence suggests the presence of transcripts for several secretory phospholipase A(2) (sPLA(2)) enzymes in male genital organs. In this study, we examined by immunohistochemistry the localization of group IIA, IIC, IID, IIE, IIF, V and X sPLA(2)s in male genital organs. In sPLA(2)-IIA-deficient C57BL/6 mouse testis, sPLA(2)-IIC, -IID, -IIE, -IIF, -V and -X were diversely expressed in spermatogenic cells within the seminiferous tubules.

Cellular arachidonate-releasing function of novel classes of secretory phospholipase A2s (groups III and XII).

Here we report cellular arachidonate (AA) release and prostaglandin (PG) production by novel classes of secretory phospholipase A(2)s (sPLA(2)s), groups III and XII. Human group III sPLA(2) promoted spontaneous AA release, which was augmented by interleukin-1, in HEK293 transfectants. The central sPLA(2) domain alone was sufficient for its in vitro enzymatic activity and for cellular AA release at the plasma membrane, whereas either the unique N- or C-terminal domain was required for heparanoid-dependent action on cells to augment AA release, cyclooxygenase-2 induction, and PG production.

Cellular arachidonate-releasing function and inflammation-associated expression of group IIF secretory phospholipase A2.

Here we report the cellular arachidonate (AA)-releasing function of group IIF secretory phospholipase A(2) (sPLA(2)-IIF), a sPLA(2) enzyme uniquely containing a longer C-terminal extension. sPLA(2)-IIF increased spontaneous and stimulus-dependent release of AA, which was supplied to downstream cyclooxygenases and 5-lipoxygenase for eicosanoid production. sPLA(2)-IIF also enhanced interleukin 1-stimulated expression of cyclooxygenase-2 and microsomal prostaglandin E synthase.