Upregulation of cytosolic phospholipase A2 correlates with apoptosis in mouse superior cervical and dorsal root ganglia neurons

The involvement of cytosolic phospholipase A₂ (cPLA₂) in apoptosis of adult mouse superior cervical and dorsal root ganglia neurons has been investigated by the use of immunohistochemistry for cPLA₂ and DNA nick-end labeling for apoptotic cells, respectively, cPLA₂ immunoreactivity was strongly upregulated in neurons of both preparations during in vitro culturing. By double labeling it was unequivocally demonstrated that cPLA₂ was present and upregulated only in neurons undergoing apoptosis. A similar picture emerged when cPLA₂ immunoreactivity was compared with staining with Fluoro-Jade, a novel fluorochrome marker for neuronal degeneration. The preferential presence of cPLA₂ in apoptotic and degenerating cells suggests that the enzyme is important for some mechanism involved in or intimately coupled to neuronal cell death.