title: Short communication: retinoic acid plus prolactin to synergistically increase specific casein gene expression in MAC-T cells.
abstract: Mammary alveolar (MAC-T) cells, an established bovine mammary epithelial cell line, are frequently used to investigate differentiation. A lactogenic phenotype in these cells is induced by treatment with a combination of hydrocortisone, insulin, and prolactin (PRL). The effect of the vitamin A derivative retinoic acid (RA), which induces differentiation in many cells, has not been studied in MAC-T cells. The objective of this study was to evaluate the differentiation potential of RA (1 μM) in MAC-T cells and to examine the effect of combined treatment with RA (1 μM) and PRL (5 μg/mL). Although RA treatment alone inhibited MAC-T cell proliferation, co-treatment of RA with PRL increased cell growth compared with the control group (treated with 1 μg/mL hydrocortisone and 5 μg/mL insulin). The ratio of Bcl to Bax mRNA was decreased in the RA treatment compared with RA+PRL or control. Retinoic acid-induced differentiation of MAC-T cells was associated with an increase in the mRNA expression of αS1-casein (3.9-fold), αS2-casein (4.5-fold), and β-casein (4.4-fold) compared with the control group. Expression of αS1-casein, αS2-casein, and β-casein was increased 12.9-fold, 11.9-fold, and 19.3-fold, respectively, following treatment with RA and PRL combined compared with the control group. These results demonstrate that RA induces differentiation of MAC-T cells and acts synergistically with PRL to increase specific casein gene expression.
authors.affiliation: Department of Animal Science, Chungbuk National University, Chungbuk 361-763, Republic of Korea.
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
authors.forename: Y T
authors.initials: YT
authors.lastname: Heo
authors.forename: S E
authors.initials: SE
authors.lastname: Lee
authors.forename: K C
authors.initials: KC
authors.lastname: Hwang
authors.forename: H G
authors.initials: HG
authors.lastname: Lee
authors.forename: S H
authors.initials: SH
authors.lastname: Choi
authors.forename: N H
authors.initials: NH
authors.lastname: Kim
mesh_terms: D000818:Animals; D002364:Caseins / Q000235:genetics*; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D004357:Drug Synergism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism*; D011388:Prolactin / Q000008:administration & dosage*; D012333:RNA, Messenger / Q000032:analysis; D014212:Tretinoin / Q000008:administration & dosage*
chemical_list: D002364:Caseins; D012333:RNA, Messenger; D014212:Tretinoin; D011388:Prolactin