Expression and localization of cFLIP, an anti-apoptotic factor, in the bovine corpus luteum.
The objective of the present study was to investigate the potential mechanisms regulating cellular FLICE-like inhibitory protein (cFLIP), an anti-apoptotic factor, in the bovine corpus luteum (CL). Expression of cFLIP mRNA was highest at the developing stage and then decreased significantly during the mid, late and regressed stages (P<0.05). Western blot analysis revealed that expression of the long isoform of cFLIP (cFLIP(L)) protein was high during the early and developing luteal stages, remained steady during the mid and late luteal stages and then decreased significantly (P<0.05) by the regressed stage. However, the expression levels of the short isoform of cFLIP (cFLIP(S)) remained low during the early, developing and mid luteal stages. Immunostaining of cFLIP was strongest in the cytoplasm of luteal and non-luteal cells, including endothelial and immune cells, remained high during the early, developing and mid luteal stages and then decreased significantly (P<0.05) in the late and regressed luteal stages. Immunostaining of cFLIP was observed only in macrophage-like cells in the regressing CL. However, cultured mid luteal cells had a higher percentage of cFLIP-positive cells and a lower percentage of TUNEL-positive cells than luteal cells treated with tumor necrosis factor alpha (TNF)/interferon gamma (IFNG; P<0.01). These results indicate downregulation of cFLIP during structural luteal regression, suggesting that cFLIP plays a survival role in the bovine CL.
Hojo
Takuo
T
Laboratory of Reproductive Endocrinology, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
Al-Zi'abi
Mohamad Omar
MO
Komiyama
Junichi
J
Manabe
Noboru
N
Acosta
Tomas J
TJ
Okuda
Kiyoshi
K
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000235:genetics* / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D015536:Down-Regulation / Q000502:physiology; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007371:Interferon-gamma / Q000494:pharmacology; D008183:Luteal Phase / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma