title: Estrous cycle dependent changes in expression and distribution of Fas, Fas ligand, Bcl-2, Bax, and pro- and active caspase-3 in the rat ovary.
abstract: In the present investigation, the localization of proteins involved in ovarian apoptosis were studied throughout the estrous cycle in the presence of fluctuating hormone levels. Fas, Fas ligand, Bcl-2, Bax and caspase-3 mRNA expression and proteins were detected in all ovarian tissue extracts, though the amount of protein varied with the phase of the estrous cycle. Fas, Bax and caspase-3 protein levels were highest at diestrus and decreased thereafter towards metestrus. In contrast, Fas ligand and Bcl-2 protein levels were lowest at diestrus and increased toward metestrus. Immunohistochemistry revealed that the staining of the anti-apoptotic protein Bcl-2 was more pronounced in healthy preantral follicles than in atretic follicles. In contrast, the pro-apoptotic proteins Fas, Fas ligand, Bax and active caspase-3 were more predominantly present in atretic follicles. In the ovarian surface epithelium (OSE), Fas, procaspase-3 and Bcl-2 immunostaining appeared independent of the phase of the estrous cycle. Fas ligand and Bax staining was detected particularly during proestrus in OSE cells surrounding the ovulatory follicles, while active caspase-3 was observed only in OSE cells at the postovulatory site during estrus. The proportion of luteal cells that stained positively for Fas, Bax and caspase-3 increased with the age of the corpus luteum, while Fas ligand and Bcl-2 immunostaining was strongest in newly formed corpora lutea and decreased thereafter. In conclusion, the components of the Fas signalling pathway were differentially expressed throughout the estrous cycle in a variety of ovarian cell types, which may correspond to hormone dependent survival mechanisms.
authors.affiliation: Department of Biochemistry & Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3508 TD Utrecht, The Netherlands.
authors.forename: Karin A
authors.initials: KA
authors.lastname: Slot
authors.forename: Marsha
authors.initials: M
authors.lastname: Voorendt
authors.forename: Mieke
authors.initials: M
authors.lastname: de Boer-Brouwer
authors.forename: Harmke H
authors.initials: HH
authors.lastname: van Vugt
authors.forename: Katja J
authors.initials: KJ
authors.lastname: Teerds
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D053148:Caspase 3; D020169:Caspases / Q000032:analysis*; D003338:Corpus Luteum / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D004971:Estrus / Q000378:metabolism*; D053222:Fas Ligand Protein; D005260:Female; D007150:Immunohistochemistry / Q000379:methods; D003341:Luteolysis / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000032:analysis*; D006080:Ovarian Follicle / Q000254:growth & development; D010053:Ovary / Q000378:metabolism*; D010060:Ovulation / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis*; D015398:Signal Transduction / Q000502:physiology; D048069:Tumor Necrosis Factors / Q000032:analysis*; D051028:bcl-2-Associated X Protein / Q000032:analysis; D019014:fas Receptor
chemical_list: D053222:Fas Ligand Protein; C491898:Fas protein, rat; C505662:Faslg protein, rat; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D048069:Tumor Necrosis Factors; D051028:bcl-2-Associated X Protein; D019014:fas Receptor; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases