Developmental stage-specific distribution of macrophages in mouse mammary gland

AbstractMammary gland development begins in the embryo and continues throughout the reproductive life of female mammals. Tissue macrophages (Mϕs), dependent on signals from the Mϕ colony stimulating factor 1 receptor (CSF1R), have been shown to regulate the generation, regression and regeneration of this organ, which is central for mammalian offspring survival. However, the distribution of Mϕs in the pre- and post-natal mammary gland, as it undergoes distinct phases of development and regression, is unknown or has been inferred from immunostaining of thin tissue sections. Here, we used optical tissue clearing and 3-dimensional imaging of mammary tissue obtained from Csf1r-EGFP mice. Whilst tissue Mϕs were observed at all developmental phases, their abundance, morphology, localization and association with luminal and basal epithelial cells exhibited stage-specific differences. Furthermore, sexual dimorphism was observed at E14.5, when the male mammary bud is severed from the overlying epidermis. These findings provide new insights into the localization and possible functions of heterogeneous tissue Mϕ populations in mammogenesis.

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HORMONAL REGULATION OF RNA AND PROTEIN SYNTHESIS IN THE MOUSE MAMMARY GLAND BEFORE AND DURING LACTATION

Journal of Endocrinology ◽

10.1677/joe.0.0500281 ◽

1971 ◽

Vol 50 (2) ◽

pp. 281-291 ◽

Cited By ~ 15

Author(s):

M. R. BANERJEE ◽

FERNE M. ROGERS ◽

D. N. BANERJEE

Keyword(s):

Protein Synthesis ◽

Mammary Gland ◽

Hormonal Regulation ◽

Rna Synthesis ◽

Mouse Mammary Gland ◽

Synthetic Activity ◽

Tissue Homogenate ◽

Mammary Tissue ◽

Leucine Incorporation

SUMMARY As measured by [3H]uridine incorporation in vivo, the low rate of RNA synthesis in the mammary gland of virgin C3H and BALB/c mice increased sixfold in the mammary tissue of 15-day pregnant mice. In the 5-day lactating gland, RNA synthesis was ten times higher than that in virgin mammary tissue. On the 10th day of lactation this increased RNA synthetic activity in the mammary gland was considerably reduced but was still twice that of the mammary tissue of virgin mice. Twenty-four hours after adrenalectomy, RNA synthesis in lactating glands was reduced by over 80%, whereas in the mammary gland before lactation, it was reduced by 20–30% only. A single i.p. injection of 250 μg of cortisol led to a threefold increase of RNA synthesis within 1 to 2 h in lactating glands of adrenalectomized mice; this was followed by a decline. Incorporation of [3H]leucine into trichloroacetic acid-insoluble material from lactating mammary tissue was used as a measure of'total protein' synthesis, and [3H]leucine radioactivity determined in Ca2+−rennin precipitate of 105000 g supernatant of lactating mammary tissue homogenate was used as a measure of casein synthesis. Adrenalectomy caused a 50% reduction of 'total protein' synthesis, whereas synthesis of 'casein-like' phosphoprotein virtually stopped after the operation. The injection of cortisol into adrenalectomized mice induced a selective increase of [3H]leucine incorporation into the casein of lactating glands. The results indicate that RNA synthesis in the mammary tissue is more dependent on adrenal hormones during the functional than the structural state of differentiation. The hormonal regulation of RNA synthesis and its role in milk protein synthesis in the mammary gland in vivo is discussed.

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Local Insulin-Like Growth Factor-II Mediates Prolactin-Induced Mammary Gland Development

Molecular Endocrinology ◽

10.1210/me.2002-0214 ◽

2003 ◽

Vol 17 (3) ◽

pp. 460-471 ◽

Cited By ~ 57

Author(s):

Russell C. Hovey ◽

Jessica Harris ◽

Darryl L. Hadsell ◽

Adrian V. Lee ◽

Christopher J. Ormandy ◽

...

Keyword(s):

Mammary Gland ◽

Early Pregnancy ◽

Insulin Receptors ◽

Mammary Glands ◽

Mouse Mammary Gland ◽

Mammary Epithelial ◽

Receptor Expression ◽

Mammary Tissue ◽

Alveolar Development

Abstract Prolactin (PRL) is a major determinant of mammary epithelial cell proliferation during alveolar development in sexually mature and pregnant mice. To date, it has not been clear whether PRL effects these responses alone or by also invoking the action of autocrine/paracrine growth factors. In this study, we provide evidence that part of the effect of PRL on mammary gland growth is mediated by IGF-II. During sexual maturity and in early pregnancy, the level of IGF-II mRNA in the mammary gland was increased concurrent with increased PRL receptor expression. The level of IGF-II mRNA was reduced in mammary tissue from PRL receptor−/− mice during early pregnancy, and explants of mouse mammary gland and HC11 mammary epithelial cells both increased their expression of IGF-II after exposure to PRL in vitro. These findings coincided with the demonstration that IGF-II stimulated alveolar development in mammary glands in whole organ culture. PRL was most efficacious in stimulating IGF-II gene transcription from promoter 3 of the mouse IGF-II gene in vitro. Insight into the mechanism by which PRL induced IGF-II expression was provided by the fact that it was blocked by the Jak2 inhibitor AG490 and the MAPK inhibitor PD98059. Finally, induction of insulin receptor substrate (IRS)-1 in the mammary glands of PRL-treated mice and induction of IRS-1 and IRS-2 after treatment with PRL plus progesterone indicates that these molecules are induced by PRL as potential signaling intermediates downstream from IGF-I/insulin receptors. Together, these data demonstrate a role for IGF-II as a mediator of PRL action in the mouse mammary gland during ductal branching and alveolar development.

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Heterogeneity of cationic amino acid transport systems in mouse mammary gland and their regulation by lactogenic hormones

Journal of Dairy Research ◽

10.1017/s0022029999003994 ◽

2000 ◽

Vol 67 (1) ◽

pp. 21-30 ◽

Cited By ~ 10

Author(s):

REKHA SHARMA ◽

VINOD K. KANSAL

Keyword(s):

Amino Acids ◽

Mammary Gland ◽

Amino Acid ◽

Mouse Mammary Gland ◽

Mammary Tissue ◽

Acid Transport ◽

Cationic Amino Acid ◽

Lactogenic Hormones ◽

Broad Specificity ◽

Specificity System

The mechanism of cationic amino acid transport in lactating mouse mammary gland was investigated. Two Na+-independent systems of arginine transport were discriminated on the basis of their sensitivity to leucine. The leucine-sensitive uptake of arginine (Km 0·4 mM) was through a broad specificity system that interacted with both cationic and neutral amino acids, and was inhibited by preloading mammary tissue with neutral amino acids. The leucine-insensitive uptake was identified as the y+ system (Km 0·76 mM). Preloading mammary tissue with cationic amino acids increased the uptake of arginine by the y+ system. Decreasing the pH of the external medium to 6·0 suppressed the y+ system-mediated uptake by ∼25%, whereas the broad specificity system remained unaffected. Lactogenic hormones upregulated the y+ system-mediated uptake of arginine in pregnant mouse mammary tissue cultured in vitro, although the broad specificity system remained unaffected. The y+ system-mediated uptake increased 2-fold with insulin alone and 4-fold with the combination of insulin, cortisol and prolactin.

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DNA POLYMERASE ACTIVITY IN MAMMARY GLAND OF VIRGIN MICE AFTER OVARIAN HORMONE TREATMENT

Journal of Endocrinology ◽

10.1677/joe.0.0510259 ◽

1971 ◽

Vol 51 (2) ◽

pp. 259-264 ◽

Cited By ~ 7

Author(s):

D. N. BANERJEE ◽

M. R. BANERJEE ◽

JANICE WAGNER

Keyword(s):

Mammary Gland ◽

Dna Polymerase ◽

Hormone Treatment ◽

Ovarian Hormones ◽

Polymerase Activity ◽

Mouse Mammary Gland ◽

Supernatant Fraction ◽

Mammary Tissue ◽

Ovariectomized Mice

SUMMARY The effect of ovarian hormones on DNA polymerase activity in the mouse mammary gland was determined. The rate of [3H]thymidine triphosphate incorporation into DNA during incubation in vitro was used as a measure of DNA polymerase activity in the post-microsomal supernatant fraction of the mammary tissue. A negligible amount of DNA polymerase activity was present in the mammary tissue of ovariectomized mice which had no hormone treatment. Daily subcutaneous injections of 1 μg oestradiol-17β plus 1 mg progesterone induced a sixfold increase of DNA polymerase activity in the mammary tissue after two injections. A single intraperitoneal injection of the same dose also induced a similar rise of DNA polymerase activity and the effect was evident within hours after the treatment. The results provide evidence that stimulation of cellular biosynthesis by the growth-promoting ovarian hormones is associated with the activation of a specific enzyme involved in DNA replication.

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Characteristics of transport systems of L-alanine in mouse mammary gland and their regulation by lactogenic hormones: evidence for two broad spectrum systems

Journal of Dairy Research ◽

10.1017/s002202999900357x ◽

1999 ◽

Vol 66 (3) ◽

pp. 385-398 ◽

Cited By ~ 10

Author(s):

REKHA SHARMA ◽

VINOD K. KANSAL

Keyword(s):

Mammary Gland ◽

Isobutyric Acid ◽

Pregnant Mouse ◽

Mouse Mammary Gland ◽

Transport Systems ◽

Mammary Tissue ◽

System A ◽

System L ◽

Lactogenic Hormones

The characteristics of the transport systems of L-alanine in lactating mouse mammary gland and their regulation by lactogenic hormones have been studied. L-alanine uptake was mediated by three Na+-dependent and one Na+- independent systems. The 2-(methylamino)isobutyric acid-sensitive component of Na+-dependent uptake exhibited the usual characteristics of system A. Cl− dependency has been established for system A. The other two Na+-dependent systems, which we have named BCl−-dependent and BCl−-independent, are described for the first time. These are systems with broad specificity and were distinguished on the basis of inhibition analysis, Cl− dependency and the effect of preloading mammary tissue with amino acids. The Na+-independent route was identified as system L, which operates independent of Cl−. The A, L and BCl−-independent transport systems were upregulated in pregnant mouse mammary tissue cultured in vitro in the presence of lactogenic hormones (insulin plus cortisol plus prolactin). Insulin alone also upregulated systems A and L to some extent in pregnant mouse mammary tissue. BCl−-dependent activity was not detected in pregnant mouse mammary tissue and was not induced by lactogenic hormones in vitro.

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OESTROGEN PRODUCTION BY THE GOAT MAMMARY GLAND: TRANSIENT AROMATASE ACTIVITY DURING LATE PREGNANCY

Journal of Endocrinology ◽

10.1677/joe.0.125r001 ◽

1990 ◽

Vol 125 (1) ◽

pp. R1-R3 ◽

Cited By ~ 14

Author(s):

M. Peaker ◽

E. Taylor

Keyword(s):

Mammary Gland ◽

Late Pregnancy ◽

Mouse Mammary Gland ◽

Mammary Tissue ◽

Aromatase Activity ◽

In Pregnancy

ABSTRACT Mammary tissue from goats had significantly higher aromatase activity at 148-149 days of pregnancy than earlier in pregnancy or during lactation. Aromatase activity was determined by production of 3H2O from [1 β–3H]androstenedione that was inhibited by 4–hydroxyandrostenedione. The time of maximum aromatization was during peak mammary output of oestradiol–17β described previously in vivo in the same species. Aromatase activity in the mouse mammary gland was low and no peak was observed in late pregnancy. It is concluded that the oestrogens produced by the mammary gland in the late–pregnant goat are formed by aromatization of androgens.

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Developmental Stage-Specific Distribution of Macrophages in Mouse Mammary Gland

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2019.00250 ◽

2019 ◽

Vol 7 ◽

Cited By ~ 15

Author(s):

Teneale A. Stewart ◽

Katherine Hughes ◽

David A. Hume ◽

Felicity M. Davis

Keyword(s):

Mammary Gland ◽

Developmental Stage ◽

Mouse Mammary Gland ◽

Specific Distribution

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Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081097 ◽

1978 ◽

Vol 36 (2) ◽

pp. 46-47

Author(s):

Jan Zarzycki ◽

Joseph Szroeder

Keyword(s):

Mammary Gland ◽

Protein Denaturation ◽

Chemical Constituents ◽

Freeze Substitution ◽

Electron Microscopic Examination ◽

Mouse Mammary Gland ◽

Electron Microscopic ◽

Preparation Methods ◽

Microscopic Studies ◽

Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

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