• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.551-558
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• 2017

To study and validate tissue-specific promoters and vectors, it is important to develop cell culture systems that retain the tissue and species specificity. Such systems are attractive alternatives to transgenic animal models. This study established a line of porcine mammary gland epithelial cells (PMECs) from a primary culture based on the cellular morphology and mRNA levels of porcine beta-casein (CSN2). The selected PMECs were stained with the cytokeratin antibody, and were shown to express milk protein genes (CSN2, lactoferrin, and whey acidic protein). In addition, to confirm the acini structure of PMEC932-7 in 3D culture, live cells were stained with SYTO-13 dye, which binds to nucleic acid. The acini of these PMECs on matrigel were formed by the aggregation of peripheral cells and featured a hollow lumens. The system was demonstrated by testing the effects of the culture conditions to cell culture including cell density and matrigel methods of the PMECs. These results suggest that PMECs possess the genetic and structural features of mammary epithelial cells.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.274-278
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• 2002

A culture system for lactating rat mammary acini was evaluated, where the primary indicator of performance was lactose secretion, measured by a sensitive bioluminescence assay. Lactose secretion was reduced by half (p<0.01) over the first 6 h of culture by overnight feed withdrawal (FW) from tissue donors but was sensitive to increased glucose concentration in the culture media (p<0.001) up to 30 mM. Lactose production of cells from fed donors over the first 6 h in culture in 30 mM glucose was 8.9 fmol/cell/h - a rate calculated to be about half that in vivo. No significant difference was shown in lactose secretion by cells from fed or FW rats over 6-24 h. Lactose secretion was 3.6 fmol/cell/h by cells from fed animals in 40 mM glucose concentration media over the 6-24 h culture period. Addition of insulin to the culture media had no effect on rates of lactose secretion while addition of prolactin and hydrocortisone, with or without insulin, significantly (p<0.001) decreased lactose production over both 0-6 h and 6-24 h culture periods. Lactose synthesis in vitro was significantly enhanced by aeration of the media during collagenase digestion of mammary tissue (p<0.05). No improvement in lactose secretion was effected by shaking of cells during culture, Matrigel coating of culture dishes or change in cell density over a range up to 2.5 million cells per ml.

• Animal Bioscience
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• v.37 no.7
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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.

• Korean Journal of Animal Reproduction
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• v.17 no.4
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• pp.375-383
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• 1994

The human growth hormone (hGH) gene uder the control of the rat $\beta$-casein promoter gene was designed to produce transgenic mouse expressed hGH gene in only mammary gland. One hundred seventy two eggs microinjected were transferred to the oviducts of pseudopregnants and 43 offspring were delivered. By Southern blotting hybridization, 3 were transgenic with rat $\beta$-casein/hGH gene. The copy numbers of three transgenic founder were 1, 5, and 15, respectively. A radioimmunoassay was developed to quantitate the amount of expression of the hGH gene in mammary gland of transgenic mice. The amount of hGH was 13.3ng/ml in the lactating milk of one transgenic line, showing predominantly higher than 3.0ng/ml in milk of control mice. Therefore, our findings suggested that $\beta$-casein promoter may induce the tissue specific expression of structural gene.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.433-441
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• 1995

Mammary tissue-specificity of the caprine $\beta$-lactoglobulin promoter appears to be secured by repression in non-expressing cells. In order to identify the mechanism of the negative regulation, the upstream promoter sequence of the caprine $\beta$-lactoglobulin gene was analyzed in detail. The repression was mediated by the upstream flanking sequence from -47O to -205. The sequence could repress the promoter activity of $\beta$-lactoglobulin in either orientation. The effect of the putative negative regulation element of caprine $\beta$-lactoglobulin on heterlogous promoters, however, varied: the promoter activity of herpes simplex virus thimidine kinase was either repressed or activated by the sequence depending on its orientation, while the SV4O early promoter was activated rather than repressed. The regulatory sequence involving the putative negative regulatory element was strongly shifted with the nuclear extract from non-mammary HeLa and CV-1 cells, while only weak shift was observed with that of mammary HC11 cells. Such correlation between repression and factor binding suggests that the protected regions in foot-printing assay may be the negative regulatory elements of $\beta$-lactoalobulin that serve tissue-specific repression.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.663-666
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• 2007

A 16-year-old female Poodle with multiple mammary masses was referred to the Veterinary Medical Teaching Hospital of Seoul National University. Radiographic finding indicated a round mass of soft tissue density at the ventral portion of the 4th-7th sternum, which was 7 cm in diameter and presented multiple mineralization within the mass. Cytologically, aspirate of the mammary mass was moderately cellular and revealed well-differentiated osteoblasts with moderately basophilic cytoplasm, various sized and eccentrically placed nuclei and distinct nucleoli. Osteoblasts interspersed with osteoid-suspected pink-staining intercellular matrix. Some cells displayed malignant features such as macronuclei, macronucleoli, binucleation, abnormal mitotic figures, anisocytosis and anisokaryosis. On which the mass was diagnosed as osteosarcoma. Histopathologic examinations of the mass were compatible with a diagnosis of osteosarcoma. The patient was treated with surgery alone. The patient died 45 days later from surgery.

• Archives of Plastic Surgery
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• v.44 no.6
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• pp.502-508
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• 2017

Background Breast-conserving therapy is defined as a breast-conserving wide local excision (WLE) of a mammary tumour combined with postoperative radiotherapy. Immediate restoration of the mammary shape by use of breast reduction techniques (volume displacement) or tissue replacement techniques (volume replacement) is gaining popularity to prevent breast malformation. Methods To date, using the internal mammary artery perforator (IMAP) flap has been suggested for immediate volume replacement after WLE, but has never been evaluated in a published study. Results We applied this flap in 12 women (mean age, 56.1 years) after WLE (mean specimen weight, 46.5 g) of the medial aspect of the breast. Over a median follow-up of 35.3 months (standard deviation, 1.2 months), 4 women needed repeated surgery for dog-ear correction of the donor site. Conclusions In our experience, the use of an IMAP flap was a reliable technique with good cosmetic outcomes after oncoplastic reconstruction. In this series, donor site revision often proved necessary initially, but we showed that this may easily be prevented.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.349-357
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• 2001

This study was conducted to examine the effect of caffeine and three dietary levels of fat, i.e., 0%, 5% and 20% on mammary gland development. Mice were assigned to three groups (dietary levels 0%, 5%, 20% fat), and treated caffeine of half within the each group. Caffeine-treated mice with 0% or 20% fat levels significantly increased 4$^{th}$ mammary gland development in comparison with that of no caffeine -treated mice (P＜0.05). Caffeine-treated mice significantly increased DNA contents of 4$^{th}$ mammary gland in comparison with that of no caffeine-treated mice (P＜0.05), and DNA contents of mammary gland increased as fat levels increased within caffeine-treated or no caffeine-treated group. nteraction effect was shown between caffeine and 20% fat diet, ［(20% fat+caffeine) - (20% fat + no caffeine) vs (0% fat + caffeine) - (0% fat + no caffeine)］(P＜0.01). Conclusively, caffeine significantly increased mouse mammary gland development possibly by inhibiting phosphodiesterase activity, and dietary fat supplements increased mammary gland development as the fat content of the diet increased from 0 to 20%. The stimulatory effect of caffeine in mammary development interacted with high level of fat diet.

• Molecules and Cells
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• v.40 no.3
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• pp.169-177
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• 2017

Tissue-specific transcription is critical for normal development, and abnormalities causing undesirable gene expression may lead to diseases such as cancer. Such highly organized transcription is controlled by enhancers with specific DNA sequences recognized by transcription factors. Enhancers are associated with chromatin modifications that are distinct epigenetic features in a tissue-specific manner. Recently, super-enhancers comprising enhancer clusters co-occupied by lineage-specific factors have been identified in diverse cell types such as adipocytes, hair follicle stem cells, and mammary epithelial cells. In addition, noncoding RNAs, named eRNAs, are synthesized at super-enhancer regions before their target genes are transcribed. Many functional studies revealed that super-enhancers and eRNAs are essential for the regulation of tissue-specific gene expression. In this review, we summarize recent findings concerning enhancer function in tissue-specific gene regulation and cancer development.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1445-1452
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• 2002

The present experiment was carried out to study the utilization of substrates in the mammary gland of crossbred Holstein Friesian during feeding on different types of roughage. Sixteen pregnant crossbred Holstein heifers consisted of two breed types of eight animals each; Holstein Friesian${\times}$Red Sindhi (50:50=50%HF) and Holstein Friesian${\times}$Red Sindhi (87.5:12.5=87.5%HF). Animals were divided into four groups of the same breed type in each group which were fed with either rice straw treated with 5% urea or pangola hay (Digitaria decumbens) as the source of roughage throughout the experiments. Four consecutive experimental periods were carried out in late pregnancy (20-23 days before parturition), early lactation (30 days postpartum), mid-lactation (120 days postpartum) and late lactation (210 days postpartum). Measurement of mammary blood flow in combining with measurement of AV difference was performed for the mammary uptake of substrates. In the period of lactation, udder blood flow was nearly three times higher than that of late pregnant period (p<0.05) in both 50%HF and 87.5%HF feeding on either hay or urea treated rice straw. During mid- and late lactation of both groups of 87.5%HF animals, mammary blood flow and milk yield showed decrease when compared to those during the early lactating period while the trends for persistency were apparent in both groups of 50%HF animals throughout experimental periods. The mean arterial plasma concentrations of glucose, acetate, $\beta$-hydroxybutyrate and free glycerol in each group remained constant throughout experimental periods. During late pregnancy in all groups, the AV difference and extraction ratio of glucose, $\beta$-hydroxybutyrate and triacylglycerol across the mammary gland markedly lowered (p<0.05), which coincided with a lower net uptake by the mammary gland in comparison to the early lactating period. The mean arterial plasma concentration, AV difference and extraction ratio for acetate showed no significant differences between late pregnancy and the early lactating period. The AV difference of free glycerol showed apparent release from mammary tissue during late pregnancy in all groups. In mid- and late lactation, the mammary uptake for glucose, acetate and $\beta$-hydroxybutyrate in both groups of 87.5%HF animals showed apparent decrease as compared to that in the early lactating period, whereas no appearances were observed in 50%HF animals feeding either hay or urea treated rice straw. The mean arterial plasma concentrations for free fatty acid (FFA) and triacylglycerol (C16 to C18) were higher in late pregnancy than in early lactation in both types of crossbred animals. The values of AV difference and the net uptake by the mammary gland for FFA were variable during late pregnancy and lactating periods in all groups. There were no significant differences for AV difference, extraction ratio and net uptake of triacylglycerol during lactation advance in both groups of 50%HF and 87.5%HF animals feeding either hay or urea treated rice straw. These results suggest that the adaptations to either hay or urea treated rice straw by the mammary gland of crossbred HF animals allow for an adequate nutrient supply during pregnancy and lactation. There is no difference in the mode of mammary uptake of substrates in the same crossbred animals in response to feeding hay or urea treated rice straw. The differences in utilizing nutrients by the mammary gland for milk production between 87.5%HF and 50%HF animals would be dependent on changes in both intra-mammary factors and extra-mammary factors.