Involvement of $PLA_2$ Isoforms in Muscarinic Receptor-Mediated sAPP Release and Store-Operated Calcium Entry in SH-SY5Y Cells.

We previously reported that phospholipase$A_2$ ($PLA_2$)-related pathway and capacitative calcium entry (CCE) via store-operated calcium channel (SOC) were involved in the regulation of muscarinic receptor- mediated sAPP release. We also observed that stimulation of muscarinic receptor associated with the inositol phosphate cascade resulted not only in increase of CCE but also in activation of PLA$_2$ in SH-SY5Y cells. In this study, we further investigated whether the $PLA_2$ isoforms differently regulate the muscarinic receptor-mediated sAPP release, and examined the relationships between activation of $PLA_2$ isoforms and CCE mediated by muscarinic receptors in SH-SY5Y cells. (omitted)