Development of mammary gland requires normal beta 1-integrin function.
To study the role of beta 1-integrins in mammary gland development we have generated transgenic mice expressing a dominant negative mutant of the beta 1-integrin chain in the mammary epithelium. The transgenic glands presented a delayed development in pregnancy and lactation due to decreased epithelial cell proliferation and increased apoptosis, whereas at the beginning of lactation, expression of milk proteins, WAP and beta-casein was diminished. In correlation with transgene expression, the basement membrane component, laminin, and the beta 4 integrin were accumulated at the lateral surface of luminal epithelial cells, revealing defects in polarization. Our data show that beta 1-integrins are involved in vivo in the control of proliferation, apoptosis, differentiation, and maintenance of baso-apical polarity of mammary epithelium.
Faraldo
M M
MM
UMR 144, CNRS-Institut Curie, Section de Recherche, Paris, France.
Deugnier
M A
MA
Thiery
J P
JP
Glukhova
M A
MA
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D019012:Integrin beta1 / Q000502:physiology*; D007774:Lactation / Q000502:physiology; D008321:Mammary Glands, Animal / Q000196:embryology / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D011247:Pregnancy
D019012:Integrin beta1