Regulation of glycosylation-dependent cell adhesion molecule 1 (GlyCAM-1) gene in the mouse mammary gland differs from that of casein genes.
Mouse glycosylation-dependent cell adhesion molecule 1 (GlyCAM-1), also known as mC26 and homologous to bovine PP3, is a milk protein synthesized in the mammary gland. Several studies have investigated the regulation of casein, the major milk protein, gene in the mammary gland, but little is known about GlyCAM-1. Here we examined GlyCAM-1 gene expression in mouse mammary epithelial cells. First, we detected GlyCAM-1 expression in mammary epithelial cells in situ by immunohistochemistry; almost all mammary epithelial cells of the lactating mouse expressed GlyCAM-1. Second, mammary epithelial cells were digested with collagenase and cultured with insulin, prolactin and/or glucocorticoid. alpha-Casein and beta-casein genes were expressed following treatment with insulin, prolactin and glucocorticoid. In contrast, GlyCAM-1 expression could not be detected with any combination of these three hormones. We also analyzed changes in the levels of GlyCAM-1 and caseins mRNAs in cultured cells. The addition of hormones to the culture medium increased casein mRNAs, but surprisingly reduced GlyCAM-1 mRNA. Our results suggest that the mechanisms that regulate GlyCAM-1 gene in mammary cells of lactating mice are different from those involved in the regulation of casein genes.
Nishimura
T
T
Department of Animal Breeding, Faculty of Agriculture, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, 113-8657, Tokyo, Japan. ntoshi@biken.osaka-u.ac.jp
Kohmoto
K
K
D000818:Animals; D015153:Blotting, Western; D001940:Breast / Q000378:metabolism*; D002364:Caseins / Q000096:biosynthesis*; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D017364:Collagenases / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation; D005938:Glucocorticoids / Q000494:pharmacology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D009077:Mucins / Q000096:biosynthesis*; D011388:Prolactin / Q000494:pharmacology; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
D002364:Caseins; D005938:Glucocorticoids; D007328:Insulin; D009077:Mucins; D012333:RNA, Messenger; C075185:sulfated glycoprotein p50; D012313:RNA; D011388:Prolactin; D003094:Collagen; D017364:Collagenases