scholarly journals Developmental regulation of Bcl-2 family protein expression in the involuting mammary gland

1999 ◽  
Vol 112 (11) ◽  
pp. 1771-1783 ◽  
Author(s):  
A.D. Metcalfe ◽  
A. Gilmore ◽  
T. Klinowska ◽  
J. Oliver ◽  
A.J. Valentijn ◽  
...  
Keyword(s):  
Cell Death ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
De Novo ◽  
Mammary Epithelial Cells ◽  
Expression Profiles ◽  
Mammary Epithelial ◽  
Mammary Tissue ◽  
Pregnancy And Lactation

Epithelial cells within the mammary gland undergo developmental programmes of proliferation and apoptosis during the pregnancy cycle. After weaning, secretory epithelial cells are removed by apoptosis. To determine whether members of the Bcl-2 gene family could be involved in regulating this process, we have examined whether changes in their expression occur during this developmental apoptotic program in vivo. Bax and Bcl-x were evenly expressed throughout development. However, expression of Bak and Bad was increased during late pregnancy and lactation, and the proteins were present during the time of maximal apoptotic involution. Thereafter, their levels declined. In contrast, Bcl-w was expressed in pregnancy and lactation but was downregulated at the onset of apoptosis. Bcl-2 was not detected in lactating or early involuting mammary gland. Thus, the pro-apoptotic proteins Bax, Bak and Bad, as well as the death-suppressors Bcl-x, Bcl-2 and Bcl-w, are synthesised in mouse mammary gland, and dynamic changes in the expression profiles of these proteins occurs during development. To determine if changes in Bak and Bcl-w expression could regulate mammary apoptosis, their effect on cultured mouse mammary epithelial cells was examined in transient transfection assays. Enforced expression of Bak induced rapid mammary apoptosis, which could be suppressed by coexpression of Bcl-w. In extracts of mammary tissue in vivo, Bak heterodimerized with Bcl-x whereas Bax associated with Bcl-w, but Bak/Bcl-w heterodimers were not detected. Thus, Bak and Bcl-w may regulate cell death through independent pathways. These results support a model in which mammary epithelial cells are primed for apoptosis during the transition from pregnancy to lactation by de novo expression of the death effectors Bak and Bad. It is suggested that these proteins are prevented from triggering apoptosis by anti-apoptotic Bcl-2 family proteins until involution, when the levels of Bcl-w decline. Our study provides evidence that regulated changes in the expression of cell death genes may contribute to the developmental control of mammary apoptosis.

scholarly journals Arginine Supply Impacts the Expression of Candidate microRNA Controlling Milk Casein Yield in Bovine Mammary Tissue

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 797 ◽  
Author(s):  
Xin Zhang ◽  
Yifan Wang ◽  
Mengzhi Wang ◽  
Gang Zhou ◽  
Lianmin Chen ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Milk Protein ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
In Vivo Study ◽  
Mammary Tissue ◽  
Casein Synthesis

Arginine, a semi-essential functional amino acid, has been found to promote the synthesis of casein in mammary epithelial cells to some extent. Data from mouse indicated that microRNA (miRNA) are important in regulating the development of mammary gland and milk protein synthesis. Whether there are potential links among arginine, miRNA and casein synthesis in bovine mammary gland is uncertain. The objective of the present work was to detect the effects of arginine supplementation on the expression of miRNA associated with casein synthesis in mammary tissue and mammary epithelial cells (BMEC). The first study with bovine mammary epithelial cells (BMEC) focused on screening for miRNA candidates associated with the regulation of casein production by arginine. The BMEC were cultured with three different media, containing 0, 1.6 and 3.2 mM arginine, for 24 h. The expression of candidate miRNA was evaluated. Subsequently, in an in vivo study, 6 Chinese Holstein dairy cows with similar BW (mean ± SE) (512.0 ± 19.6 kg), parity (3), BCS (4.0) and DIM (190 ± 10.3 d) were randomly assigned to three experimental groups. The experimental cows received an infusion of casein, arginine (casein plus double the concentration of arginine in casein), and alanine (casein plus alanine, i.e., iso-nitrogenous to the arginine group) in a replicated 3 × 3 Latin square design with 22 d for each period (7 d for infusion and 15 d for washout). Mammary gland biopsies were obtained from each cow at the end of each infusion period. Results of the in vitro study showed differences between experimental groups and the control group for the expression of nine miRNA: miR-743a, miR-543, miR-101a, miR-760-3p, miR-1954, miR-712, miR-574-5p, miR-468 and miR-875-3p. The in vivo study showed that arginine infusion promoted milk protein content, casein yield and the expression of CSN1S1 and CSN1S2. Furthermore, the expression of miR-743a, miR-543, miR-101a, miR-760-3p, miR-1954, and miR-712 was also greater in response to arginine injection compared with the control or alanine group. Overall, results both in vivo and in vitro revealed that arginine might partly influence casein yield by altering the expression of 6 miRNAs (miR-743a, miR-543, miR-101a, miR-760-3p, miR-1954, and miR-712).

Bovine mammary epithelial cells, initiators of innate immune responses to mastitis

2005 ◽  
Vol 45 (8) ◽  
pp. 757 ◽  
Author(s):  
C. Gray ◽  
Y. Strandberg ◽  
L. Donaldson ◽  
R. L. Tellam
Keyword(s):  
Immune Response ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Vital Role ◽  
Mammary Epithelial ◽  
Innate Immune ◽  
Mammary Tissue ◽  
Effector Cells ◽  
Bovine Mammary Epithelial Cells

Innate immunity plays a vital role in the protection of the bovine mammary gland against mastitis. Until recently, the migration of effector cells such as neutrophils and monocytes into the mammary gland was thought to provide the only defence against invading pathogens. However, mammary epithelial cells may also play an important role in the immune response, contributing to the innate defence of the mammary tissue through secretion of antimicrobial peptides and attraction of circulating immune effector cells. This paper reviews the innate immune pathways in mammary epithelial cells and examines their role in the initiation of an innate immune response to Gram-positive and Gram-negative bacteria.

The role of Stat3 in mammary gland involution: cell death regulator and modulator of inflammation

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Katherine Hughes ◽  
Christine J. Watson
Keyword(s):  
Cell Death ◽  
Transcription Factor ◽  
Mammary Gland ◽  
Mammary Epithelial Cells ◽  
Expression Profiles ◽  
Global Gene Expression ◽  
Mammary Epithelial ◽  
Second Phase ◽  
Independent Manner ◽  
Microarray Analyses

AbstractMammary gland regression post-weaning (involution) is a highly regulated, complicated process in which the transcription factor Stat3 is a key player. Over the last decade, microarray analyses have had a profound impact on our understanding of this role. Studies using mammary epithelial cells in which Stat3 was activated in a ligand-independent manner have allowed direct transcriptional targets of Stat3 to be identified. Additionally, global gene expression changes during involution have been profiled by microarray analyses, which allowed characterization of clusters of genes with distinct expression profiles during the first 4 days of involution. Such expression profiling led to the observation that one of the most strikingly upregulated genes in the absence of Stat3 is the serpin Spi2a. This led to the discovery that mammary epithelial cell lysosomes undergo lysosomal membrane permeablisation and leak cathepsins during involution. Stat3 upregulates the expression of cathepsins B and L within 24 h of weaning and is thus the critical inducer of lysosomal-mediated cell death during this process. In addition to its pivotal role in the control of cell death during involution, microarray-based studies have demonstrated that the expression of acute phase and inflammatory genes is regulated by Stat3 and that mammary epithelial expression of this transcription factor modulates the phenotype of macrophages present in the gland during second phase remodelling. Thus, Stat3 signalling may have effects that are not cell-autonomous, in addition to its cell-autonomous role in involution.

scholarly journals Prototheca zopfiiGenotype II induces mitochondrial apoptosis in models of bovine mastitis

2019 ◽  
Author(s):  
Muhammad Shahid ◽  
Eduardo R. Cobo ◽  
Liben Chen ◽  
Paloma A. Cavalcante ◽  
Herman W. Barkema ◽  
...  
Keyword(s):  
Cell Death ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Bovine Mastitis ◽  
Mammary Epithelial ◽  
Mitochondrial Apoptosis ◽  
Prototheca Zopfii ◽  
Severe Inflammation ◽  
Mammary Tissues

AbstractPrototheca zopfiiis an alga increasingly isolated from bovine mastitis. Of the two genotypes ofP. zopfii(genotype I and II (GT-I and II)),P. zopfiiGT-II is the genotype associated with acute mastitis and decreased milk production by unknown mechanisms. The objective was to determine inflammatory and apoptotic roles ofP. zopfiiGT-II in cultured mammary epithelial cells (from cattle and mice) and murine macrophages and using a murine model of mastitis.Prototheca zopfiiGT-II (but not GT-I) invaded bovine and murine mammary epithelial cells (MECs) and induced apoptosis, as determined by the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling assay. ThisP. zopfiiGT-II driven apoptosis corresponded to mitochondrial pathways; mitochondrial transmembrane resistance (ΔΨm) was altered and modulation of mitochondrion-mediated apoptosis regulating genes changed (increased transcriptionalBax, cytochrome-c andApaf-1and downregulatedBcl-2), whereas caspase-9 and -3 expression increased. Apoptotic effects byP. zopfiiGT-II were more pronounced in macrophages compared to MECs. In a murine mammary infection model,P. zopfiiGT-II replicated in the mammary gland and caused severe inflammation with infiltration of macrophages and neutrophils and upregulation of pro-inflammatory genes (TNF-α,IL-1βandCxcl-1) and also apoptosis of epithelial cells. Thus, we concludedP. zopfiiGT-II is a mastitis-causing pathogen that triggers severe inflammation and also mitochondrial apoptosis.Author summaryBovine mastitis (inflammation of the udder) reduces milk production and quality, causing huge economic losses in the dairy industry worldwide. Although the algaPrototheca zopfiiis a major cause of mastitis in dairy cows, mechanisms by which it damages mammary tissues are not well known. Here, we used cell cultures and a mouse model of mastitis to determine howProtothecacaused inflammation and cell death in mammary tissues.Protothecainvaded mammary gland cells, from cattle and mice, as well as macrophages (white cells that take up and kill pathogens) and caused cell death by interfering with mitochondria. Furthermore,Protothecacauses severe inflammation and tissue damage when injected into the mammary glands of mice. Although there are two genotypes ofP. zopfii, only genotype II causes tissue damage, whereas gentotype I, common in farm environments, does not damage mammary tissues. SinceP. zopfiiis an alga and not a bacterium, antibiotic treatments, frequently used to treat mastitis in cattle, are not effective against this organism. Understanding howP. zopfiidamages mammary tissue and causes mastitis is important new knowledge to promote future development of evidence-based approaches to prevent and treat mammary gland infections with this organism.

scholarly journals Muramyl Dipeptide Synergizes with Staphylococcus aureus Lipoteichoic Acid To Recruit Neutrophils in the Mammary Gland and To Stimulate Mammary Epithelial Cells

2010 ◽  
Vol 17 (11) ◽  
pp. 1797-1809 ◽  
Author(s):  
Salim Bougarn ◽  
Patricia Cunha ◽  
Abdallah Harmache ◽  
Angélina Fromageau ◽  
Florence B. Gilbert ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Synergistic Effects ◽  
Muramyl Dipeptide ◽  
Lipoteichoic Acid ◽  
Mammary Epithelial ◽  
Mammary Tissue ◽  
Chemokine Production

ABSTRACT Staphylococcus aureus, a major pathogen for the mammary gland of dairy ruminants, elicits the recruitment of neutrophils into milk during mastitis, but the mechanisms are incompletely understood. We investigated the response of the bovine mammary gland to muramyl dipeptide (MDP), an elementary constituent of the bacterial peptidoglycan, alone or in combination with lipoteichoic acid (LTA), another staphylococcal microbial-associated molecular pattern (MAMP). MDP induced a prompt and marked influx of neutrophils in milk, and its combination with LTA elicited a more intense and prolonged influx than the responses to either stimulus alone. The concentrations of several chemoattractants for neutrophils (CXCL1, CXCL2, CXCL3, CXCL8, and C5a) increased in milk after challenge, and the highest increases followed challenge with the combination of MDP and LTA. MDP and LTA were also synergistic in inducing in vitro chemokine production by bovine mammary epithelial cells (bMEpC). Nucleotide-binding oligomerization domain 2 (NOD2), a major sensor of MDP, was expressed (mRNA) in bovine mammary tissue and by bMEpC in culture. The production of interleukin-8 (IL-8) following the stimulation of bMEpC by LTA and MDP was dependent on the activation of NF-κB. LTA-induced IL-8 production did not depend on platelet-activating factor receptor (PAFR), as the PAFR antagonist WEB2086 was without effect. In contrast, bMEpC and mammary tissue are known to express Toll-like receptor 2 (TLR2) and to respond to TLR2 agonists. Although the levels of expression of the inflammatory cytokines tumor necrosis factor alpha (TNF-α) and IL-1β were increased by LTA and MDP at the mRNA level, no protein could be detected in the bMEpC culture supernatant. The level of induction of IL-6 was low at both the mRNA and protein levels. These results indicate that MDP and LTA exert synergistic effects to induce neutrophilic inflammation in the mammary gland. These results also show that bMEpC could contribute to the inflammatory response by recognizing LTA and MDP and secreting chemokines but not proinflammatory cytokines. Overall, this study indicates that the TLR2 and NOD2 pathways could cooperate to trigger an innate immune response to S. aureus mastitis.

Conditional loss of PTEN leads to precocious development and neoplasia in the mammary gland

Development ◽  
2002 ◽  
Vol 129 (17) ◽  
pp. 4159-4170 ◽  
Author(s):  
Gang Li ◽  
Gertraud W. Robinson ◽  
Ralf Lesche ◽  
Hilda Martinez-Diaz ◽  
Zhaorong Jiang ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Pten Gene ◽  
Mammary Tissue ◽  
Breast Cancers ◽  
Gene Mutant ◽  
Mammary Epithelia ◽  
Ductal Branching

PTEN tumor suppressor is frequently mutated in human cancers, including breast cancers. Female patients with inherited PTEN mutations suffer from virginal hypertrophy of the breast with high risk of malignant transformation. However, the exact mechanisms of PTEN in controlling mammary gland development and tumorigenesis are unclear. In this study, we generated mice with a mammary-specific deletion of the Pten gene. Mutant mammary tissue displayed precocious lobulo-alveolar development, excessive ductal branching, delayed involution and severely reduced apoptosis. Pten null mammary epithelial cells were disregulated and hyperproliferative. Mutant females developed mammary tumors early in life. Similar phenotypes were observed in Pten-null mammary epithelia that had been transplanted into wild-type stroma, suggesting that PTEN plays an essential and cell-autonomous role in controlling the proliferation, differentiation and apoptosis of mammary epithelial cells.

Proteinases of the mammary gland: developmental regulation in vivo and vectorial secretion in culture

Development ◽  
1991 ◽  
Vol 112 (2) ◽  
pp. 439-449 ◽  
Author(s):  
R.S. Talhouk ◽  
J.R. Chin ◽  
E.N. Unemori ◽  
Z. Werb ◽  
M.J. Bissell
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Cell Function ◽  
Mammary Development ◽  
Mammary Epithelial ◽  
The Other ◽  
Mammary Tissue ◽  
Tissue Inhibitor Of Metalloproteinases ◽  
Tissue Extracts

The extracellular matrix (ECM) is an important regulator of mammary epithelial cell function both in vivo and in culture. Substantial remodeling of ECM accompanies the structural changes in the mammary gland during gestation, lactation and involution. However, little is known about the nature of the enzymes and the processes involved. We have characterized and studied the regulation of cell-associated and secreted mammary gland proteinases active at neutral pH that may be involved in degradation of the ECM during the different stages of mammary development. Mammary tissue extracts from virgin and pregnant CD-1 mice resolved by zymography contained three major proteinases of 60K (K = 10(3) Mr), 68K and 70K that degraded denatured collagen. These three gelatinases were completely inhibited by the tissue inhibitor of metalloproteinases. Proteolytic activity was lowest during lactation especially for the 60K gelatinase which was shown to be the activated form of the 68K gelatinase. The activated 60K form decreased prior to parturition but increased markedly after the first two days of involution. An additional gelatin-degrading proteinase of 130K was expressed during the first three days of involution and differed from the other gelatinases by its lack of inhibition by the tissue inhibitor of metalloproteinases. The activity of the casein-degrading proteinases was lowest during lactation. Three caseinolytic activities were detected in mammary tissue extracts. A novel 26K cell-associated caseinase—a serine arginine-esterase—was modulated at different stages of mammary development. The other caseinases, at 92K and a larger than 100K, were not developmentally regulated. To find out which cell type produced the proteinases in the mammary gland, we isolated and cultured mouse mammary epithelial cells. Cells cultured on different substrata produced the full spectrum of gelatinases and caseinases seen in the whole gland thus implicating the epithelial cells as a major source of these enzymes. Analysis of proteinases secreted by cells grown on a reconstituted basement membrane showed that gelatinases were secreted preferentially in the direction of the basement membrane. The temporal pattern of expression of these proteinases and the basal secretion of gelatinases by epithelial cells suggest their involvement in the remodelling of the extracellular matrix during the different stages of mammary development and thus modulation of mammary cell function.

scholarly journals Expression of Prolactin mRNA in Rat Mammary Gland During Pregnancy and Lactation

2000 ◽  
Vol 48 (3) ◽  
pp. 389-395 ◽  
Author(s):  
Toshiki Iwasaka ◽  
Shinobu Umemura ◽  
Kochi Kakimoto ◽  
Haruko Koizumi ◽  
Yoshiyuki R. Osamura
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Late Pregnancy ◽  
Mammary Epithelial ◽  
Rt Pcr ◽  
Pregnancy And Lactation ◽  
Rat Mammary Gland ◽  
Pcr Method

We studied the expression of prolactin (PRL) mRNA in the mammary gland of resting, pregnant, lactating, and weanling rats using in situ and solution reverse transcriptase-polymerase chain reaction (RT-PCR). In mid- to late pregnancy and throughout lactation, PRL mRNA was detected in both in situ and solution RT-PCR. These PRL mRNA signals were clearly identified in the cytoplasm of alveolar and ductal mammary epithelial cells by the in situ RT-PCR method. In mid- to late pregnancy, such as at the initiating point of PRL mRNA expression, we confirmed in some cases a lack of PRL mRNA by solution RT-PCR. In addition, in the early weaning phase, no signals were detected by solution RT-PCR. However, slight focal signals were detected in some poorly vacuolated cytoplasm of regressing acinar cells by in situ RT-PCR. These findings suggest that PRL mRNA in rat mammary gland begins in mid- to late pregnancy in parallel with the development of the mammary gland, continues throughout lactation, and declines in the early phase of weaning, with regression of mammary epithelial cells.

RagD regulates amino acid mediated-casein synthesis and cell proliferation via mTOR signalling in cow mammary epithelial cells

2018 ◽  
Vol 85 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Ying Mu ◽  
Dongmei Zheng ◽  
Cong Wang ◽  
Wei Yu ◽  
Xiaonan Zhang
Keyword(s):  
Cell Proliferation ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Mammary Tissue ◽  
Lactation Period ◽  
Mtor Inhibition ◽  
Pregnancy And Lactation ◽  
Casein Synthesis

This research paper addresses the hypothesis that RagD is a key signalling factor that regulates amino acid (AA) mediated-casein synthesis and cell proliferation in cow mammary epithelial cells (CMECs). The expression of RagD was analysed at different times during pregnancy and lactation in bovine mammary tissue from dairy cows. We showed that expression of RagD at lactation period was higher (P < 0·05) than that at pregnancy period. When CMECs were treated with methionine (Met) or lysine (Lys), expression of RagD, β-casein (CSN2), mTOR and p-mTOR, and cell proliferation were increased. Further, when CMECs were treated to overexpress RagD, expression of CSN2, mTOR and p-mTOR, and cell proliferation were up-regulated. Furthermore, the increase in expression of CSN2, mTOR and p-mTOR, and cell proliferation in response to Met or Lys supply was inhibited by inhibiting RagD, and those effects were reversed in the overexpression model. When CMECs were treated with RagD overexpression together with mTOR inhibition or conversely with RagD inhibition together with mTOR overexpression, results showed that the increase in expression of CSN2 and cell proliferation in response to RagD overexpression was prevented by inhibiting mTOR, and those effects were reversed by overexpressing mTOR. The interaction of RagD with subunit proteins of mTORC1 was analysed, and the result showed that RagD interacted with Raptor. CMECs were treated with Raptor inhibition, and the result showed that the increase in expression of mTOR and p-mTOR in response to RagD overexpression was inhibited by inhibiting Raptor.In conclusion, our study showed that RagD is an important activation factor of mTORC1 in CMECs, activating AA-mediated casein synthesis and cell proliferation, potentially acting via Raptor.

scholarly journals MicroRNA in the ovine mammary gland during early pregnancy: spatial and temporal expression of miR-21, miR-205, and miR-200

2013 ◽  
Vol 45 (4) ◽  
pp. 151-161 ◽  
Author(s):  
Laurent Galio ◽  
Stéphanie Droineau ◽  
Patrick Yeboah ◽  
Hania Boudiaf ◽  
Stephan Bouet ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Early Pregnancy ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Normal Mammary Gland ◽  
Basal Cells ◽  
Pregnancy And Lactation ◽  
Luminal Cells

The mammary gland undergoes extensive remodeling between the beginning of pregnancy and lactation; this involves cellular processes including cell proliferation, differentiation, and apoptosis, all of which are under the control of numerous regulators. To unravel the role played by miRNA, we describe here 47 new ovine miRNA cloned from mammary gland in early pregnancy displaying strong similarities with those already identified in the cow, human, or mouse. A microarray study of miRNA variations in the adult ovine mammary gland during pregnancy and lactation showed that 100 miRNA are regulated according to three principal patterns of expression: a decrease in early pregnancy, a peak at midpregnancy, or an increase throughout late pregnancy and lactation. One miRNA displaying each pattern (miR-21, miR-205, and miR-200b) was analyzed by qRT-PCR. Variations in expression were confirmed for all three miRNA. Using in situ hybridization, we detected both miR-21 and miR-200 in luminal mammary epithelial cells when expressed, whereas miR-205 was expressed in basal cells during the first half of pregnancy and then in luminal cells during the second half. We therefore conclude that miR-21 is strongly expressed in the luminal cells of the normal mammary gland during early pregnancy when extensive cell proliferation occurs. In addition, we show that miR-205 and miR-200 are coexpressed in luminal cells, but only during the second half of pregnancy. These two miRNA may cooperate to maintain epithelial status by repressing an EMT-like program, to achieve and preserve the secretory phenotype of mammary epithelial cells.

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