Regulation of genes encoding proteolytic enzymes during mammary gland development.
The mammary gland undergoes extensive tissue remodelling during each lactation cycle. During pregnancy, the epithelial compartment of the gland is vastly expanded (Benaud et al. 1998). At the end of lactation the epithelial cells undergo apoptosis and adipocyte differentiation is induced (Lilla et al. 2002). Ductal and alveolar growth during puberty and pregnancy, and the involution process require the action of proteolytic enzymes (including matrix metalloproteinases, plasminogen and membrane-peptidases) and the corresponding genes are activated during these periods (Benaud et al. 1998; Alexander et al. 2001). Matrix metalloproteinases (MMP) are expressed in several cell types of the mammary gland including stromal fibroblasts (e.g., MMP3, MMP2), epithelial cells (e.g., MMP7 or MMP9), adipocytes (e.g., MMP2) and lymphoid cells (e.g., MMP9) (Crawford et al. 1996; Lund et al. 1996; Wiseman et al. 2003). A number of knock-out mice, which are deficient for individual MMP genes (e.g., MMP2, MMP3) or plasminogen, display alterations to mammary gland structure and impairment of lactation (Lund et al. 1999; Wiseman et al. 2003).
Sorrell
David A
DA
Molecular Recognition Group, Hannah Research Institute, Ayr, UK.
Szymanowska
Malgorzata
M
Boutinaud
Marion
M
Robinson
Claire
C
Clarkson
Richard W E
RW
Stein
Torsten
T
Flint
David J
DJ
Kolb
Andreas F
AF
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D007774:Lactation / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000098:blood supply / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D011247:Pregnancy