title: Oestradiol enhances apoptosis in bovine mammary epithelial cells in vitro.
abstract: Ovarian steroids, oestradiol and progesterone, are required for normal mammary growth at puberty and during pregnancy. They contribute to mammary parenchyma development by stimulating mammary epithelial cell (MEC) proliferation. However several studies demonstrate that oestradiol negatively affects milk production during the declining phase of lactation, but the oestradiol effect on MEC in lactating mammary gland remains unclear. The objective of this study was to investigate the differential effect of oestradiol on bovine MECs mimicking two physiological statuses: active and early apoptotic MECs. We demonstrated that oestradiol has a major effect on early apoptotic MECs and might accelerate MEC apoptosis by activation of caspases rather than by inducing apoptosis in active MECs. Early apoptotic MECs could be compared with senescent cells in the late-lactation mammary gland. These results suggest that the negative effect of oestradiol on milk production during the declining phase of lactation would be due to an enhancement of apoptotic processes in MECs.
authors.affiliation: INRA, UMR1348 Pegase, F-35590 Saint-Gilles, France.
authors.forename: Lucile
authors.initials: L
authors.lastname: Yart
authors.forename: Laurence
authors.initials: L
authors.lastname: Finot
authors.forename: Vanessa
authors.initials: V
authors.lastname: Lollivier
authors.forename: Frederic
authors.initials: F
authors.lastname: Dessauge
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002417:Cattle; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects* / Q000502:physiology*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007774:Lactation; D008321:Mammary Glands, Animal / Q000166:cytology*
chemical_list: D004958:Estradiol; D020169:Caspases