Effect of NGF on the subcellular localization of group IIA secretory phospholipase A(2) (GIIA) in PC12 cells: role in neuritogenesis.

Phospholipases A(2) (PLA(2)s) are involved in neuritogenesis but the identity of the isoforms(s) contributing to this process is still not defined. Several reports have focused on secretory PLA(2)s (sPLA(2)) as the administration of exogenous sPLA(2)s to PC12 neuronal cells stimulates neurite outgrowth. The present study demonstrates that the endogenous group IIA sPLA(2) (GIIA), constitutively expressed in mammalian neural cells, changes its subcellular localization when PC12 cells are induced to differentiate by NGF treatment. Indeed, confocal analysis showed a time-dependent accumulation of GIIA in growth cones and neurite tips. Under identical conditions the subcellular distribution of another isoform (GV) was unaffected by NGF. Contrary to GX, another sPLA(2) isoform expressed by PC12 cells, the contribution of GIIA to neuritogenesis does not require its release in the extracellular medium.