TY - JOUR
T1 - Growth hormone and lactogenic hormones can reduce the leptin mRNA expression in bovine mammary epithelial cells
AU - Yonekura, Shinichi
AU - Sakamoto, Kazuhito
AU - Komatsu, Tokushi
AU - Hagino, Akihiko
AU - Katoh, Kazuo
AU - Obara, Yoshiaki
PY - 2006/7/1
Y1 - 2006/7/1
N2 - Leptin mRNA is expressed in not only adipocytes but also mammary epithelial cells and leptin protein is present in milk. Although milk leptin is thought to influence metabolism or the immune system in neonates, there is little information about the regulation of leptin expression in mammary epithelial cells. We examined the effect of growth hormone (GH) and/or lactogenic hormone complex (DIP; dexamethasone, insulin and prolactin) on leptin mRNA expression in mammary epithelial cells. We used a bovine mammary epithelial cell (BMEC) clonal line, which was established from a 26-day pregnant Holstein heifer. We confirmed that the mRNA was expressed in BMECs and the expression was significantly reduced by GH and/or DIP, when the cells were cultured on both plastic plates and cell culture inserts at days 2 and 7 after stimulation with lactogenic hormones. GH and/or DIP significantly increased level of α-casein mRNA in BMECs after 7 days on the cell culture inserts, but no mRNA expression was detected at day 2. GH and DIP significantly stimulated the secretion of α-casein from BMEC on cell culture inserts at 3.5 and 7 days. However, neither α-casein mRNA expression nor secretion was observed in the BMECs cultured on plastic dishes, even in the presence of GH or/and DIP. These results indicate that GH and DIP can directly reduce leptin mRNA expression in both undifferentiated and functionally differentiated bovine mammary epithelial cell.
AB - Leptin mRNA is expressed in not only adipocytes but also mammary epithelial cells and leptin protein is present in milk. Although milk leptin is thought to influence metabolism or the immune system in neonates, there is little information about the regulation of leptin expression in mammary epithelial cells. We examined the effect of growth hormone (GH) and/or lactogenic hormone complex (DIP; dexamethasone, insulin and prolactin) on leptin mRNA expression in mammary epithelial cells. We used a bovine mammary epithelial cell (BMEC) clonal line, which was established from a 26-day pregnant Holstein heifer. We confirmed that the mRNA was expressed in BMECs and the expression was significantly reduced by GH and/or DIP, when the cells were cultured on both plastic plates and cell culture inserts at days 2 and 7 after stimulation with lactogenic hormones. GH and/or DIP significantly increased level of α-casein mRNA in BMECs after 7 days on the cell culture inserts, but no mRNA expression was detected at day 2. GH and DIP significantly stimulated the secretion of α-casein from BMEC on cell culture inserts at 3.5 and 7 days. However, neither α-casein mRNA expression nor secretion was observed in the BMECs cultured on plastic dishes, even in the presence of GH or/and DIP. These results indicate that GH and DIP can directly reduce leptin mRNA expression in both undifferentiated and functionally differentiated bovine mammary epithelial cell.
KW - Bovine mammary epithelial cell
KW - Differentiation
KW - GH
KW - Lactogenic hormone
KW - Leptin
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UR - http://www.scopus.com/inward/citedby.url?scp=33646844498&partnerID=8YFLogxK
U2 - 10.1016/j.domaniend.2005.09.002
DO - 10.1016/j.domaniend.2005.09.002
M3 - Article
C2 - 16198527
AN - SCOPUS:33646844498
VL - 31
SP - 88
EP - 96
JO - Domestic Animal Endocrinology
JF - Domestic Animal Endocrinology
SN - 0739-7240
IS - 1
ER -