RT Journal Article
SR Electronic
T1 Human Group IIA Secretory Phospholipase A<sub>2</sub> Induces Neuronal Cell Death via Apoptosis
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 114
OP 126
DO 10.1124/mol.61.1.114
VO 61
IS 1
A1 Tatsurou Yagami
A1 Keiichi Ueda
A1 Kenji Asakura
A1 Satoshi Hata
A1 Takayuki Kuroda
A1 Toshiyuki Sakaeda
A1 Nobuo Takasu
A1 Kazushige Tanaka
A1 Takefumi Gemba
A1 Yozo Hori
YR 2002
UL http://molpharm.aspetjournals.org/content/61/1/114.abstract
AB Expression of group IIA secretory phospholipase A2(sPLA2-IIA) is documented in the cerebral cortex (CTX) after ischemia, suggesting that sPLA2-IIA is associated with neurodegeneration. However, how sPLA2-IIA is involved in the neurodegeneration remains obscure. To clarify the pathologic role of sPLA2-IIA, we examined its neurotoxicity in rats that had the middle cerebral artery occluded and in primary cultures of cortical neurons. After occlusion, sPLA2 activity was increased in the CTX. An sPLA2 inhibitor, indoxam, significantly ameliorated not only the elevated activity of the sPLA2 but also the neurodegeneration in the CTX. The neuroprotective effect of indoxam was observed even when it was administered after occlusion. In primary cultures, sPLA2-IIA caused marked neuronal cell death. Morphologic and ultrastructural characteristics of neuronal cell death by sPLA2-IIA were apoptotic, as evidenced by condensed chromatin and fragmented DNA. Before apoptosis, sPLA2-IIA liberated arachidonic acid (AA) and generated prostaglandin D2 (PGD2), an AA metabolite, from neurons. Indoxam significantly suppressed not only AA release, but also PGD2 generation. Indoxam prevented neurons from sPLA2-IIA–induced neuronal cell death. The neuroprotective effect of indoxam was observed even when it was administered after sPLA2-IIA treatment. Furthermore, a cyclooxygenase-2 inhibitor significantly prevented neurons from sPLA2-IIA–induced PGD2 generation and neuronal cell death. In conclusion, sPLA2-IIA induces neuronal cell death via apoptosis, which might be associated with AA metabolites, especially PGD2. Furthermore, sPLA2 contributes to neurodegeneration in the ischemic brain, highlighting the therapeutic potential of sPLA2-IIA inhibitors for stroke.