Growth hormone suppresses the expression of IGFBP-5, and promotes the IGF-I-induced phosphorylation of Akt in bovine mammary epithelial cells

2007 ◽  
Vol 32 (4) ◽  
pp. 260-272 ◽  
Author(s):  
Kazuhito Sakamoto ◽  
Tomoki Yano ◽  
Takuya Kobayashi ◽  
Akihiko Hagino ◽  
Hisashi Aso ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Bovine Mammary Epithelial Cells ◽  
Igf I

Growth hormone acts on the synthesis and secretion of α-casein in bovine mammary epithelial cells

2005 ◽  
Vol 72 (3) ◽  
pp. 264-270 ◽  
Author(s):  
Kazuhito Sakamoto ◽  
Tokushi Komatsu ◽  
Takuya Kobayashi ◽  
Michael T Rose ◽  
Hisashi Aso ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Epithelial Cells ◽  
Mrna Expression ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Gh Treatment ◽  
Bovine Mammary Epithelial Cells ◽  
Lactogenic Hormone ◽  
Mammary Epithelia

To study the effect of growth hormone (GH) on the functions of mammary epithelia, we examined the effect of GH on the synthesis and secretion of α-casein in a bovine mammary epithelial cell (BMEC) clonal line, which was established from a 26-d-pregnant Holstein heifer. GH receptors (GHR) were observed in the BMEC on the membrane as well as in the cytoplasm. After BMEC were plated onto cell culture inserts, GH stimulated α-casein release in both the presence and absence of the lactogenic hormone complex, which included dexamethasone, insulin and prolactin (DIP). DIP enhanced the effect of GH on α-casein release. Although αs1-casein mRNA expression was not detected in untreated control cells, its expression was observed in BMEC in response to the GH, DIP and GH+DIP treatments. Expression was greater for GH and GH+DIP than for just DIP. Expression of GHR mRNA was increased by DIP treatment, while the mRNA expression was little changed by GH treatment. We conclude that GH acts on BMEC and induces the expression of both the α-casein gene and protein. GHR gene expression was shown to be regulated by DIP and GHR. GHR may be involved in a synergic effect between GH and DIP on casein secretion. These results suggest that GH, in addition to its widely accepted homeorhetic role in vivo, also can act on the mammary parenchyma, and that the effects of GH on mammary epithelial cells could partly account for the clear galactopoietic effect of recombinant bovine GH seen in lactating dairy cows.

IGF-I, EGF, and sex steroids regulate autophagy in bovine mammary epithelial cells via the mTOR pathway

2009 ◽  
Vol 88 (2) ◽  
pp. 117-130 ◽  
Author(s):  
Agnieszka Sobolewska ◽  
Malgorzata Gajewska ◽  
Joanna Zarzyńska ◽  
Barbara Gajkowska ◽  
Tomasz Motyl
Keyword(s):  
Epithelial Cells ◽  
Sex Steroids ◽  
Mammary Epithelial Cells ◽  
Mtor Pathway ◽  
Mammary Epithelial ◽  
Bovine Mammary Epithelial Cells ◽  
Igf I

The effect of calcium on mammary epithelial cell proliferation and the plasminogen activating system

1999 ◽  
Vol 79 (3) ◽  
pp. 277-283 ◽  
Author(s):  
F. Cheli ◽  
B. Zavizion ◽  
O. Todoulou ◽  
I. Politis
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Extracellular Calcium ◽  
Mammary Epithelial ◽  
Bovine Mammary Epithelial Cells ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Igf I ◽  
Pai 1

The objectives of this study were to examine 1) the effect of extracellular calcium on proliferation of bovine mammary epithelial cells, 2) whether extracellular calcium regulates the mitogenic effect of insulin-like growth factor (IGF-I) and epidermal growth factor (EGF) towards mammary epithelial cells, and 3) whether the effects of calcium on growth are mediated through changes in the plasminogen activating system. The BME-UV1 cells were used as a model system. Results showed that optimal proliferation of BME-UV1 cells grown in the presence of 10% dialyzed FBCS was achieved when the culture medium was supplemented with 1–2 mmol L−1 of extracellular Ca2+. IGF-I (P<0.01) but not EGF, increased proliferation of BME-UV1 cells. Furthermore, calcium does not regulate IGF-I and EGF responsiveness of BME-UV1 cells. Northern blot analysis was performed to examine the effect of extracellular calcium on expression of urokinase-type plasminogen activator (u-PA), PA inhibitor 1 (PAI-1) and u-PA receptor (u-PAR) genes by BME-UV1 cells in culture. Results showed that calcium increased expression of all above-mentioned genes after 24 h of exposure of cells to calcium, at a time that the effect of calcium on growth was not apparent. Calcium had no effect on u-PA and u-PAR expression after 48 and 72 h of exposure of cells to calcium, at a time that the effect of calcium on growth was predominant. Calcium caused a small increase of PAI-1 expression after 48 and 72 h but this small increase is apparently of limited biological value. Key words: Mammary epithelial cells, calcium, growth factors, plasminogen activating system

Growth hormone and lactogenic hormones can reduce the leptin mRNA expression in bovine mammary epithelial cells

2006 ◽  
Vol 31 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Shinichi Yonekura ◽  
Kazuhito Sakamoto ◽  
Tokushi Komatsu ◽  
Akihiko Hagino ◽  
Kazuo Katoh ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Epithelial Cells ◽  
Mrna Expression ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Bovine Mammary Epithelial Cells ◽  
Lactogenic Hormones

Differential effects of retinoids on proliferation of bovine mammary epithelial cells in collagen gel culture

2001 ◽  
Vol 68 (2) ◽  
pp. 157-164 ◽  
Author(s):  
STIG PURUP ◽  
SØREN KROGH JENSEN ◽  
KRIS SEJRSEN
Keyword(s):  
Cell Proliferation ◽  
Retinoic Acid ◽  
Growth Factors ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Collagen Gel ◽  
Mammary Epithelial ◽  
Bovine Mammary Epithelial Cells ◽  
Igf I

The effects of increasing concentrations of retinol, retinal and retinoic acid on proliferation of bovine mammary epithelial cells were investigated in collagen gel cultures. All retinoids significantly inhibited proliferation of mammary epithelial cells. The relative inhibitory potency of the retinoids was: retinoic acid > retinal > retinol. Maximal inhibition at 10 μg/ml corresponded to a 75–95% inhibition of proliferation obtained in basal medium. Retinol, retinal and retinoic acid also inhibited proliferation of cells growth-stimulated with insulin-like growth factor-I (IGF-I). Retinoids in highest concentrations (10 μg/ml) inhibited 68–85% of proliferation of cells obtained in culture medium containing 25 ng IGF-I/ml. Retinol and retinoic acid also inhibited proliferation of cells growth-stimulated by insulin and other growth factors from the IGF growth factor family (des(1-3)IGF-I and IGF-II), as well as growth factors from the epidermal growth factor family (EGF and TGF-α), with retinoic acid being more effective than retinol. At a concentration of 100 ng/ml, retinol and retinoic acid inhibited respectively 24–38 and 44–52% of mammary cell proliferation stimulated by growth factors of the IGF family, and at 10000 ng/ml, 61–71% of cell proliferation was inhibited. The growth-stimulating effect of insulin, EGF and TGF-α was inhibited 42–64% by retinol and retinoic acid at 100 ng/ml, and 64–84% at 10000 ng/ml. The present results show that retinol, retinal and retinoic acid are potent inhibitors of bovine mammary epithelial cell proliferation. It is suggested that retinoids may have concentration-dependent roles in regulation of pubertal mammary growth and development, indicating that the milk yield potential of heifers may be affected by vitamin A status.

scholarly journals Effects of adenosine 5'-triphosphate and growth hormone on cellular H+ transport and calcium ion concentrations in cloned bovine mammary epithelial cells

2001 ◽  
Vol 169 (2) ◽  
pp. 381-388 ◽  
Author(s):  
K Katoh ◽  
T Komatsu ◽  
S Yonekura ◽  
H Ishiwata ◽  
A Hagino ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Dependent Manner ◽  
Efflux Rate ◽  
Bovine Mammary Epithelial Cells ◽  
Lactogenic Hormones ◽  
Cloned Bovine

The present experiment was carried out to investigate the effects of exogenous adenosine 5'-triphosphate (ATP) and growth hormone (GH) on cellular H(+) efflux rate (extracellular acidification rate) and Ca(2+) concentration ([Ca(2+)](c)) in cloned bovine mammary epithelial cells (bMEC) raised from the mammary gland of a 26-day-pregnant Holstein heifer. Perifusion of 2-day cultured cells with a medium containing ATP (10, 100 and 1000 micromol/l) for 30 min caused a significant and concentration-dependent increase in the cellular H(+) efflux rate. ATP application (100 micromol/l) caused a transient and large increase in [Ca(2+)](c) in all cells. In contrast, perifusion with a medium containing bovine GH at 10, 50 and 250 ng/ml for 30 min caused a significant decrease in the cellular H(+) efflux rate in a concentration-dependent manner. However, bovine GH application (50 ng/ml) caused a small decrease followed by an increase, in some cases, in [Ca(2+)](c). In bMEC treated with lactogenic hormones (1 microgram/l prolactin, 1 nmol/ml dexamethasone and 5 microgram/ml insulin) for 2 days, the increased H(+) efflux rate induced by ATP was significantly reduced, whereas the negative response induced by GH was inversely and significantly changed to the positive. Treatment of the cells with lactogenic hormones reduced the increase in [Ca(2+)](c) induced by ATP stimulation, while it enhanced the increase in [Ca(2+)](c) induced by GH stimulation. Application of ATP or GH did not cause any significant changes in [pH](c). Treatment with lactogenic hormones enhanced GH receptor (GHR) transcription that was determined by RT-PCR. From these results, we conclude that exogenous application of ATP and GH causes prompt and significant responses in H(+) transport and [Ca(2+)](c) that were significantly changed in the opposite direction by the treatment with lactogenic hormones. The lactogenic hormone treatment also enhanced GHR transcription, which may change post-receptor signal transduction systems for both agents in the bMEC.

scholarly journals 5-ALA Attenuates the Palmitic Acid-Induced ER Stress and Apoptosis in Bovine Mammary Epithelial Cells

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1183
Author(s):  
Mst Mamuna Sharmin ◽  
Md Aminul Islam ◽  
Itsuki Yamamoto ◽  
Shin Taniguchi ◽  
Shinichi Yonekura
Keyword(s):  
T Cells ◽  
Epithelial Cells ◽  
Palmitic Acid ◽  
Er Stress ◽  
Aminolevulinic Acid ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Protective Effects ◽  
Bovine Mammary Epithelial Cells ◽  
Induced Apoptosis

The conservation of mammary gland physiology by maintaining the maximum number of mammary epithelial cells (MECs) is of the utmost importance for the optimum amount of milk production. In a state of negative energy balance, palmitic acid (PA) reduces the number of bovine MECs. However, there is no effective strategy against PA-induced apoptosis of MECs. In the present study, 5-aminolevulinic acid (5-ALA) was established as a remedial agent against PA-induced apoptosis of MAC-T cells (an established line of bovine MECs). In PA-treated cells, the apoptosis-related genes BCL2 and BAX were down- and upregulated, respectively. The elevated expression of major genes of the unfolded protein response (UPR), such as CHOP, a proapoptotic marker (C/EBP homologous protein), reduced the viability of PA-treated MAC-T cells. In contrast, 5-ALA pretreatment increased and decreased BCL2 and BAX expression, respectively. Moreover, cleaved caspase-3 protein expression was significantly reduced in the 5-ALA-pretreated group in comparison with the PA group. The downregulation of major UPR-related genes, including CHOP, extended the viability of MAC-T cells pretreated with 5-ALA and also reduced the enhanced intensity of the PA-induced expression of phospho-protein kinase R-like ER kinase. Moreover, the enhanced expression of HO-1 (antioxidant gene heme oxygenase) by 5-ALA reduced PA-induced oxidative stress (OxS). HO-1 is not only protective against OxS but also effective against ER stress. Collectively, these findings offer new insights into the protective effects of 5-ALA against PA-induced apoptosis of bovine MECs.

Sign in / Sign up

Export Citation Format

Share Document