Corpus luteum regression in the rat--in vivo and in vitro studies of apoptotic mechanisms.
Apoptosis has been implicated in corpus luteum regression. Prostaglandin F2 alpha (PGF2alpha) is a luteolytic agent known to induce corpus regression in the rat. We have shown previously that staurosporine, a protein kinase C inhibitor, induces apoptosis in corpora luteal cells. In this study, we hypothesize that PGF2alpha and staurosporine will induce apoptosis in the rat corpus luteum and this process is mediated through the mitochondrial phospholipid cardiolipin and activation of caspase-9. Female prepubertal rats were superovulated and luteal cells were analyzed for apoptosis after treatment with a luteolytic dose of PGF2alpha (in vivo study) or cultured and treated with 10(-5) M PGF2alpha or 1 alphaM staurosporine (in vitro studies). Apoptosis was measured by annexin V and propidium iodide staining, loss of fluorescence of 10-N-nonyl acridine orange (NAO), a cardiolipin specific fluorescent dye, and cleavage of pro-caspase-9 by western blot analysis. PGF2alpha treatment demonstrated evidence of apoptosis in vivo, while staurosporine treatment demonstrated evidence of apoptosis in vitro. We provide, for the first time in the rat ovary, evidence that apoptosis during corpus luteum regression is mediated in part by mitochondria and by cleavage activation of caspase-9.
Department of Obstetrics, Gynecology and Women's Health, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Lisa M
LM
Dauffenbach
Shah M
SM
Khan
John
J
Yeh
D000818:Animals; D017209:Apoptosis; D002308:Cardiolipins / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002478:Cells, Cultured; D015237:Dinoprost / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D008184:Luteal Cells / Q000166:cytology* / Q000187:drug effects; D003341:Luteolysis / Q000187:drug effects*; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000378:metabolism; D051381:Rats; D019311:Staurosporine / Q000494:pharmacology*
D002308:Cardiolipins; D015237:Dinoprost; D053453:Caspase 9; D019311:Staurosporine