• 대한수의학회지
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• 제52권4호
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• pp.269-273
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• 2012

In the present study, we investigated the expression patterns of ErbB family proteins in the pre-pubertal and pubertal mammary glands of dairy cows in association with gland development. For this study, we performed immunohistochemistry for ErbB-1-4 and Ki-67 cell proliferation marker. We found that the pre-pubertal and pubertal mammary glands had typical structures, including ducts and terminal end buds embedded in the stroma, and no development of lobuloalveolar structures. On immunohistochemistry, ErbB-2 and ErbB-3 were strongly expressed in the cytoplasm and nuclei in the epithelial cells of mammary ducts and terminal end buds, and stromal cells, whereas ErbB-1 and ErbB-4 were weakly expressed only in the cytoplasm of gland epithelium and stromal cells, irrespective of the developmental stage. Cell proliferation was inactive in the mammary gland cell compartments in both phases. Thus, expression of the ErbB family in the developing mammary glands was not associated with their functional effects, such as cell proliferation and lobuloalveolar development. In conclusion, ErbB receptors were differentially expressed in the epithelial and stromal cells of virgin mammary glands of dairy cows. Compared with rodent mammary glands, ErbB-3 and ErbB-4 were found to be highly expressed in bovine mammary glands.

• 한국동물생명공학회지
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• 제37권3호
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• pp.169-175
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• 2022

Bovine mammary epithelial (MAC-T) cells are commonly used to study mammary gland development and mastitis. Lipopolysaccharide is a major bacterial cell membrane component that can induce inflammation. Autophagy is an important regulatory mechanism participating in the elimination of invading pathogens. In this study, we evaluated the mechanism underlying bacterial mastitis and mammary cell death following lipopolysaccharide treatment. After 24 h of 50 ㎍/mL lipopolysaccharide treatment, a significant decrease in the proliferation rate of MAC-T cells was observed. However, no changes were observed upon treatment of MAC-T cells with 10 ㎍/mL of lipopolysaccharide for up to 48 h. Thus, upon lipopolysaccharide treatment, MAC-T cells exhibit dose-dependent effects of growth inhibition at 10 ㎍/mL and death at 50 ㎍/mL. Treatment of MAC-T cells with 50 ㎍/mL lipopolysaccharide also induced the expression of autophagy-related genes ATG3, ATG5, ATG10, ATG12, MAP1LC3B, GABARAP-L2, and BECN1. The autophagy-related LC3A/B protein was also expressed in a dose-dependent manner upon lipopolysaccharide treatment. Based on these results, we suggest that a high dose of bacterial infection induces mammary epithelial cell death related to autophagy signals.

• 한국발생생물학회지:발생과생식
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• 제4권2호
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• pp.221-229
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• 2000

유선에서 젖의 생산은 뇌하수체 호르몬인 성장 호르몬과 프롤락틴을 포함한 여러 가지 호르몬의 조절을 받는다. 최근의 연구에 따르면 이 호르몬들 중에서 성장호르몬과 프롤락틴은 유선에서도 그 유전자 전사체가 발견된다 본 연구에서는 유선에서 발현되는 성장호르몬이 유선 특이 발현 유전자의 발현에 미치는 영향을 조사하고자 유선 특이 발현 유전자인 베타-락토글로불린($\beta$-lactoglobulin :BLG)의 프로모터를 모델 시스템으로 하여 소와 사람의 성장 호르몬이 유선의 유전자 발현에 끼치는 영향을 조사하였다. 성장 호르몬은 단독으로 처리하였을 패 베타-락토글로불린 유전자 프로모터 활성을 억제하였다. 그러나 젖 분비 호르몬들인 인슐린, 프롤락틴, 글루코코르티코이드와 함께 처리하였을 때는 농도 의존적으로 BLG 프로모터 활성을 상승시키는 효과를 보였다. 성장 호르몬을 유선 세포내에서 발현시켰을때는 적정농도에서 세포 증식과 유선 프로모터 활성을 크게 증진시켰다. 반면 소의 성장 호르몬 유전자 프로모터는 유선 세포에서 뚜렷한 활성을 나타내지 않았다. 이상의 결과는 유선에서 발현되는 뇌하수체 호르몬들은 조절 누수에 의한 유전자 발현이 아니라 생리적 기능을 가지고 있음을 의미한다. 또 인위적으로 성장호르몬의 발현을 조절하여 적정한 양이 발현되도록 하면 젖의 생산을 증진시킬 수 있다는 가능성도 암시한다.

• 대한수의학회지
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• 제36권3호
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• pp.647-655
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• 1996

To establish the effective ways to prevent bovine mastitis, the study has been performed to investigate the attributable factors causing down-regulation of immune responses in mammary gland of non-lactating cows. Lymphocytes from peripheral blood and mammary gland secretions(MGS) were obtained from normal healthy cows and mastitic cows, respectively. Lymphoblastogenesis were investigated carefully by adding different concentrations of supernatants collected from pure-cultures of neutrophils seperated from peripheral blood and MGS, respectively. The results obtained are as follows ; 1. Lymphoblastogenesis activity stimulated by Con A, PWM and PHA were significantly reduced in MGS from mastitic cows. 2. Supernatants collected from pure-culture of neutrophils separated both from peripheral blood and MGS showed inhibitory effect on mitogenic lymphoblastogenesis. 3. Supernatants from mammary gland neutrophils have shown 7 times more inhibitory activity than those from peripheral blood and this inhibitory effect was increased in proportion to increasing concentrations of supernatants when those were added to lymphoblast cells in culture.

• 대한수의학회지
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• 제36권3호
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• pp.635-646
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• 1996

To establish the effective ways to prevent bovine mastitis, the study has been performed to investigate the attributable factors causing down-regulation of immune responses in mammary gland of non-lactating cows. Lymphocytes from peripheral blood and mammary gland secretions(MGS) were obtained from normal healthy cows and mastitic cows, respectively. Cellular immune responses were examined by comparison of proportion of lymphocyte subpopulations using a set of monoclonal antibodies and flow cytometry. The results obtained are as follows. 1. Proportions of peripheral blood lymphocyte subpopulations expressing BoCD2 and BoCD4 molecules were 32.9%, 15.4% in mastitic cows and 43.3%, 28.3% in normal healthy cows, respectively. The ratios of BoCD4 to BoCD8 were 0.76 and 1.47, respectively. 2. Proportions of mammary gland lymphocyte subpopulations expressing BoCD2 and BoCD4 molecules were 18.5%, 8.3% in mastitic cows and 38.2%, 14.2% in normal healthy cows, respectively. The ratios of BoCD4 to BoCD8 were 0.6 and 2.0, respectively. 3. Proportions of T lymphocyte subpopulations from MGS were significantly lower than those from peripheral blood both in mastitic cows and normal healthy cows. However, lymphocyte subpopulations expressing ACT2 and ACT3, which represent activated T suppressor cells, were significantly higher in MGS than those in peripheral blood.

• Animal Bioscience
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• 제37권7호
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• pp.1289-1302
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• 2024

Objective: There is a strong relationship between the content of beneficial fatty acids in milk and milk fat metabolic activity in the mammary gland. To improve milk quality, it is therefore necessary to study fatty acid metabolism in bovine mammary gland tissue. In adipose tissue, peroxisome proliferator-activated receptor gamma (PPARG), the core transcription factor, regulates the fatty acid metabolism gene network and determines fatty acid deposition. However, its regulatory effects on mammary gland fatty acid metabolism during lactation have rarely been reported. Methods: Transcriptome sequencing was performed during the prelactation period and the peak lactation period to examine mRNA expression. The significant upregulation of PPARG drew our attention and led us to conduct further research. Results: According to bioinformatics prediction, dual-luciferase reporter system detection, real-time quantitative reverse transcription polymerase chain reaction and Western blotting, miR-130a and miR-130b could directly target PPARG and inhibit its expression. Furthermore, triglyceride and oil red O staining proved that miR-130a and miR-130b inhibited milk fat metabolism in bovine mammary epithelial cells (BMECs), while PPARG promoted this metabolism. In addition, we also found that the coexpression of miR-130a and miR-130b significantly enhanced their ability to regulate milk fat metabolism. Conclusion: In conclusion, our findings indicated that miR-130a and miR-130b could target and repress PPARG and that they also have a functional superposition effect. miR-130a and miR-130b seem to synergistically regulate lipid catabolism via the control of PPARG in BMECs. In the long-term, these findings might be helpful in developing practical means to improve high-quality milk.

• 한국축산식품학회지
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• 제18권2호
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• pp.185-191
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• 1998

Human milk and bovine milk in normal stage were fractionated four parts : whey, skimmilk membrane, and casein pellet. The specific activity (nmole / mim / mg protein) and distribution ratio(%) of suborganella marker enzymes in each separated milk fraction were determined. Especially, neutral $Ca^{2+}$-ATPase, acid $Ca^{2+}$-ATPase, NADH-cytochrome C reductase, and acid phosphatase were higher in human milk. However, both $Ca^{2+}$-ATPases were not detected in all fractions of bovine milk. On the other hand, 5'-nucleotidase, phosphodiesterase I, alkaline phosphatase, and $\gamma$-glutamyl transpeptidase activities in bovine milk were higher than in human milk. Most of the marker enzymes were highly distributed in cream fraction of either human milk or bovine milk, and their specific activities were high to 24 fold from 3 fold when compared with that of whole milk. These results suggest that marker enzymes in mammary epitherial cell are transfered into cream fraction by the membrane rearrangement, and different biochemical reaction between human and bovine exists for milk secretion in mammary gland.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.922-936
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• 2022

5-Hydroxytryptamine (5-HT), a monoamine, as a local regulator in the mammary gland is a chemical signal produced by the mammary epithelium cell. In cows, studies have shown that 5-HT is associated with epithelial cell apoptosis during the degenerative phase of the mammary gland. However, studies in other tissues have shown that 5-HT can effectively promote cell viability. Whether 5-HT could have an effect on mammary cell viability in dairy cows is still unknown. The purpose of this study was to determine: (1) effect of 5-HT on the viability of bovine mammary epithelial cells and its related signaling pathways, (2) interaction between prolactin (PRL) and 5-HT on the cell viability. The bovine mammary alveolar cell-T (MAC-T) were cultured with different concentrations of 5-HT for 12, 24, 48 or 72 hours, and then were assayed using cell counting kit-8, polymerase chain reaction (PCR) and immunobloting. The results suggested that 20 μM 5-HT treatment for 12 or 24 h promote cell viability, which was mainly induced by the activation of 5-HT receptor (5-HTR) 1B and 4, because the increase caused by 5-HT vanished when 5-HTR 1B and 4 was blocked by SB224289 and SB204070. And protein expression of mammalian target of rapamycin (mTOR), eukaryotic translation elongation factor 2 (eEF2), janus kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5) were decreased after blocking 5-HT 1B and 4 receptors. When MAC-T cells were treated with 5-HT and PRL simultaneously for 24 h, both the cell viability and the level of mTOR protein were significantly higher than that cultured with 5-HT or PRL alone. In conclusion, our study suggested that 5-HT promotes the viability of MAC-T cells by 5-HTR 1B and/or 4. Furthermore, there is a reciprocal relationship between PRL and 5-HT.

• Asian-Australasian Journal of Animal Sciences
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• 제18권11호
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• pp.1600-1608
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• 2005

The study was carried out to evaluate the effect of exogenous bovine somatotropin on water metabolism in relation to mammary function in early lactation of crossbred Holstein cattle. Ten, 87.5% crossbred Holstein cattle were divided into two groups of 5 animals each. At day 60 of lactation, the control group was given placebo while animals in the experimental group were given recombinant bovine somatotropin (rbST) by subcutaneous injection with 500 mg of rbST (14-days prolonged-release rbST). In rbSTtreated animals, milk yield increased 19.8%, which coincided with a significant increase in water intake (p<0.01), while DM daily intake was not different when compared to the control animals. Water turnover rate as absolute values significantly increased (p<0.05), while the biological half-life of water did not change in rbST-treated animals. Total body water (TBW) and total body water space (TOH) as absolute values significantly increased (p<0.01) in rbST-treated animals, while it was decreased in the control animals. Absolute values of empty body water (EBW) markedly increased (p<0.05), which was associated with an increase in the extracellular fluid (ECF) volume. Absolute values of plasma volume and blood volume were also significantly increased (p<0.05) in rbST-treated animals. The increase in mammary blood flow in rbST-treated animals was proportionally higher than an increase in milk production. The plasma IGF-1 concentration was significantly increased (p<0.01) in rbST-treated animals when compared with those of control animals during the treatment period. Milk fat concentration increased during rbST treatment, while the concentrations of both protein and lactose in milk were not affected. The present results indicate that rbST exerts its effect on an increase in both TBW and EBW. An increased ECF compartment in rbST-treated animals might partly result from the decrease in fat mass during early lactation. The action of rbST on mammary blood flow might not be mediated solely by the action of IGF-1 for increase in blood flow to mammary gland. An elevation of body fluid during rbST treatment in early lactation may be partly a result of an increase in mammary blood flow in distribution of milk precursors to the gland.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.212-212
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• 2004

Collagen has been widely studied for medical applications. Previous studies have shown that the bovine β-casein promoter were able to drive cell-specific and hormone-dependent expression to a mouse mammary cell line but failed to induce accurate expression to the mammary gland. of transgenic mice. (omitted)