Various phospholipases A2 (PLA2) are present in the nervous tissue where they participate in physiological and pathological processes: Ca2+-dependent low molecular weight PLA2s, generally referred as secretory enzymes (sPLA2), have recently received particular attention. Administration of exogenous sPLA2s to PC12 cells was shown to stim- ulate neurite outgrowth as a consequence of the enzyme activity rather than its binding to the cells (Nakashima et al., Brain Res. 1015:207, 2004). We have reported that two sPLA2 isoforms have different local- ization in PC12 (Macchioni et al., JBC 279:37860, 2004): group IIA sPLA2 (GIIA) is largely present in perinuclear mitochondria and group V sPLA2 (GV) is mostly localized in the nucleus. In this study, we investigated the effects of NGF on subcellular localization of both GIIA and GV in PC12. Confocal analysis showed that when PC12 were induced to differentiate in neuronal-like cells by NGF (100ng/ml), GIIA was predominantly found in growth cones and tips of neurite and it was no longer detectable in mitochondria, while the distribution of GV was unaffected. NGF treatment increased PLA2 activity both in PC12 cells and in the culture medium, and a specific inhibitor of sPLA2s (Indoxam, Shionogi) (Suzuki et al., JBC 275:5785, 2000) com- pletely inhibited enzyme activity, pointing to a selective release of sPLA2, likely GIIA. These results suggest that: a) NGF induces changes in the localization of GIIA but not of GV; b) NGF-induced GIIA translocation might be functionally linked to the NGF-dependent neurite outgrowth; c) NGF-induced GIIA release might be part of a mechanism by which NGF stimulates neuronal differentiation.
EFFECT OF NGF ON PHOSPHOLIPASES A2 LOCALIZATION IN PC12 CELLS
FERRINI, Monica;MACCHIONI, Lara;NARDICCHI, Vincenza;ARCURI, Cataldo;NICOLETTI, Ildo;DONATO, Rosario Francesco;GORACCI, Gianfrancesco
2005
Abstract
Various phospholipases A2 (PLA2) are present in the nervous tissue where they participate in physiological and pathological processes: Ca2+-dependent low molecular weight PLA2s, generally referred as secretory enzymes (sPLA2), have recently received particular attention. Administration of exogenous sPLA2s to PC12 cells was shown to stim- ulate neurite outgrowth as a consequence of the enzyme activity rather than its binding to the cells (Nakashima et al., Brain Res. 1015:207, 2004). We have reported that two sPLA2 isoforms have different local- ization in PC12 (Macchioni et al., JBC 279:37860, 2004): group IIA sPLA2 (GIIA) is largely present in perinuclear mitochondria and group V sPLA2 (GV) is mostly localized in the nucleus. In this study, we investigated the effects of NGF on subcellular localization of both GIIA and GV in PC12. Confocal analysis showed that when PC12 were induced to differentiate in neuronal-like cells by NGF (100ng/ml), GIIA was predominantly found in growth cones and tips of neurite and it was no longer detectable in mitochondria, while the distribution of GV was unaffected. NGF treatment increased PLA2 activity both in PC12 cells and in the culture medium, and a specific inhibitor of sPLA2s (Indoxam, Shionogi) (Suzuki et al., JBC 275:5785, 2000) com- pletely inhibited enzyme activity, pointing to a selective release of sPLA2, likely GIIA. These results suggest that: a) NGF induces changes in the localization of GIIA but not of GV; b) NGF-induced GIIA translocation might be functionally linked to the NGF-dependent neurite outgrowth; c) NGF-induced GIIA release might be part of a mechanism by which NGF stimulates neuronal differentiation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
