Impaired lactation in mice expressing dominant-negative FADD in mammary epithelium.
The Fas-associated death domain (FADD/Mort1) adaptor protein was originally identified as a key mediator of apoptosis, although pleiotropic functions for FADD have also been reported. FADD-mediated tumoricidal effects have been described in breast cancer cells; however, its physiological role in normal mammary gland epithelium is not well understood. To determine the role of FADD signaling during mammary gland development, we generated transgenic mice overexpressing dominant-negative FADD (DN-FADD) in mammary epithelium, using the steroid responsive mouse mammary tumor virus promoter. Transgenic mice exhibited a perturbation in lactation resulting in impaired milk production and pup growth retardation. Reduced expansion of alveoli was evident during early lactation with extensive shedding of luminal alveolar cells. Significantly more TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling)-positive cells were present at this time point and a subsequent increase in bromodeoxyuridine-positive cells was observed. These findings suggest a role for FADD in maintaining the survival of mammary secretory alveolar cells after the establishment of lactation.
Shackleton
Mark
M
Molecular Genetics of Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.
O'Reilly
Lorraine A
LA
Sutherland
Kate D
KD
Bath
Mary L
ML
Ellis
Sarah
S
Strasser
Andreas
A
Visvader
Jane E
JE
Lindeman
Geoffrey J
GJ
D000818:Animals; D004848:Epithelium / Q000378:metabolism*; D053200:Fas-Associated Death Domain Protein / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D005799:Genes, Dominant; D007774:Lactation; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D046529:Microscopy, Electron, Transmission
C505534:Fadd protein, mouse; D053200:Fas-Associated Death Domain Protein