TY - JOUR
T1 - Developmental expression patterns and regulation of connexins in the mouse mammary gland
T2 - Expression of connexin30 in lactogenesis
AU - Talhouk, Rabih S.
AU - Elble, Randolph C.
AU - Bassam, Rola
AU - Daher, Mariam
AU - Sfeir, Agnel
AU - Mosleh, Lina Abi
AU - El-Khoury, Hilda
AU - Hamoui, Samar
AU - Pauli, Bendicht U.
AU - El-Sabban, Marwan E.
N1 - Funding Information:
This work was supported by the University Research Board and Lebanese National Council for Scientific Research (R.S.T. and M.E. S.), the Medical Practice Plan, Diana Tamari Sabbagh Research Fund, Terry Fox Cancer Research fund (M.E.S.), Third world Academy of Science (R.S.T.) and United States Army Breast Cancer Research Fund grant DAMD17-00-1-0219 (R.C.E.)
PY - 2005/1
Y1 - 2005/1
N2 - The mammary gland reaches a fully differentiated phenotype at lactation, a stage characterized by the abundant expression of β-casein. We have investigated the expression and regulation of gap junction proteins (connexins, Cx) during the various developmental stages of mouse mammary gland. Immunohistochemical analysis, with specific antibodies, reveals that Cx26 and Cx32 are expressed and confined to the cell borders of luminal epithelial cells in all developmental stages of the gland. Cx26 and Cx32 expression, at the mRNA and protein levels, increases in pregnancy and peaks in lactation. Whereas Cx43 mRNA decreases in pregnancy and lactation, the functional activity of Cx43 protein, which has been localized to myoepithelial cells, is regulated (through phosphorylation) during pregnancy and peaks during lactation. Cx30 mRNA and proteins have, for the first time, been detected in mammary gland epithelia. Using reverse transcription/polymerase chain reaction and sequencing techniques, we show that Cx30 is abundant in pregnant and lactating mammary gland. Cx30 protein levels have not been detected in the mammary gland prior to day 15 of pregnancy, whereas maximum expression occurs at the onset of lactation. In mouse mammary cells in culture, Cx30 is epithelial-cell-specific and is induced by lactogenic hormones. These data identify a novel player in mammary differentiation and suggest a potential role for Cx30 in the fully differentiated gland.
AB - The mammary gland reaches a fully differentiated phenotype at lactation, a stage characterized by the abundant expression of β-casein. We have investigated the expression and regulation of gap junction proteins (connexins, Cx) during the various developmental stages of mouse mammary gland. Immunohistochemical analysis, with specific antibodies, reveals that Cx26 and Cx32 are expressed and confined to the cell borders of luminal epithelial cells in all developmental stages of the gland. Cx26 and Cx32 expression, at the mRNA and protein levels, increases in pregnancy and peaks in lactation. Whereas Cx43 mRNA decreases in pregnancy and lactation, the functional activity of Cx43 protein, which has been localized to myoepithelial cells, is regulated (through phosphorylation) during pregnancy and peaks during lactation. Cx30 mRNA and proteins have, for the first time, been detected in mammary gland epithelia. Using reverse transcription/polymerase chain reaction and sequencing techniques, we show that Cx30 is abundant in pregnant and lactating mammary gland. Cx30 protein levels have not been detected in the mammary gland prior to day 15 of pregnancy, whereas maximum expression occurs at the onset of lactation. In mouse mammary cells in culture, Cx30 is epithelial-cell-specific and is induced by lactogenic hormones. These data identify a novel player in mammary differentiation and suggest a potential role for Cx30 in the fully differentiated gland.
KW - Connexin
KW - Differentiation
KW - Gap junctions
KW - Lactation
KW - Mammary gland
KW - Mouse (BALB/c, female)
UR - http://www.scopus.com/inward/record.url?scp=19944427043&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=19944427043&partnerID=8YFLogxK
U2 - 10.1007/s00441-004-0915-5
DO - 10.1007/s00441-004-0915-5
M3 - Article
C2 - 15517403
AN - SCOPUS:19944427043
SN - 0302-766X
VL - 319
SP - 49
EP - 59
JO - Cell and Tissue Research
JF - Cell and Tissue Research
IS - 1
ER -