Fibronectin fragments induce MMP activity in mouse mammary epithelial cells: evidence for a role in mammary tissue remodeling

2000 ◽  
Vol 113 (5) ◽  
pp. 795-806 ◽  
Author(s):  
P. Schedin ◽  
R. Strange ◽  
T. Mitrenga ◽  
P. Wolfe ◽  
M. Kaeck

Mammary gland form and function are regulated by interactions between epithelium and extracellular matrix. Major glycoprotein components of extracellular matrix have been identified that give survival, proliferation and differentiation signals to mammary epithelial cells. We provide evidence that proteolytic fragments of the extracellular matrix glycoprotein, fibronectin, suppress growth and can promote apoptosis of mouse mammary epithelial cells. During mammary gland involution, total fibronectin and fibronectin fragment levels are increased. The peak levels of fibronectin protein and fragments are observed 4–6 days post-weaning, coincident with the peak in epithelial cell death. Using a model for hormone withdrawal-induced death of mammary epithelium, elevated levels of fibronectin proteolytic fragments were associated with apoptosis in TM-6 cells, a tumorigenic mouse mammary epithelial cell line. Treatment of TM-6 cells with exogenous fibronectin fragments (FN120) reduced cell number, and induced apoptosis and matrix degrading protease activity. Inhibition of matrix protease activity rescued TM-6 cell viability, indicating that FN120-induced cell loss is mediated through matrix protease activity. In a three-dimensional model for mammary gland development, FN120 reduced alveolar-like and promoted ductal-like development by a matrix protease-dependent mechanism. These data suggest that during post-lactational involution, fibronectin fragments may contribute to epithelial cell loss and dissolution of mammary alveoli by inducing matrix degrading proteinases.

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3194
Author(s):  
Yutaka Suzuki ◽  
Sachi Chiba ◽  
Koki Nishihara ◽  
Keiichi Nakajima ◽  
Akihiko Hagino ◽  
...  

Epithelial barrier function in the mammary gland acts as a forefront of the defense mechanism against mastitis, which is widespread and a major disorder in dairy production. Chemerin is a chemoattractant protein with potent antimicrobial ability, but its role in the mammary gland remains unelucidated. The aim of this study was to determine the function of chemerin in mammary epithelial tissue of dairy cows in lactation or dry-off periods. Mammary epithelial cells produced chemerin protein, and secreted chemerin was detected in milk samples. Chemerin treatment promoted the proliferation of cultured bovine mammary epithelial cells and protected the integrity of the epithelial cell layer from hydrogen peroxide (H2O2)-induced damage. Meanwhile, chemerin levels were higher in mammary tissue with mastitis. Tumor necrosis factor alpha (TNF-α) strongly upregulated the expression of the chemerin-coding gene (RARRES2) in mammary epithelial cells. Therefore, chemerin was suggested to support mammary epithelial cell growth and epithelial barrier function and to be regulated by inflammatory stimuli. Our results may indicate chemerin as a novel therapeutic target for diseases in the bovine mammary gland.


2011 ◽  
Vol 14 (3) ◽  
pp. 433-442 ◽  
Author(s):  
M. Kozłowski ◽  
J. Wilczak ◽  
T. Motyl ◽  
M. Gajewska

Role of extracellular matrix and prolactin in functional differentiation of bovine BME-UV1 mammary epithelial cells Interactions between extracellular matrix (ECM) and epithelial cells are necessary for proper organisation and function of the epithelium. In the present study we show that bovine mammary epithelial cell line BME-UV1 cultured on ECM components, commercially available as Matrigel™, constitutes a good model for studying mechanisms controlling functional differentiation of the bovine mammary gland. In contact with Matrigel BME-UV1 cells induce apicobasal polarity, and within 16 days form three dimensional (3D) acinar structures with a centrally localized hollow lumen, which structurally resemble mammary alveoli present in the functionally active mammary gland. We have shown that the 3D culture system enables a high expression and proper localisation of integrin receptors and tight junction proteins in BME-UV1 cells to be induced. This effect was not obtained in cells grown in the classical 2D culture system on plastic. Moreover, ECM highly stimulated the synthesis of one of the major milk proteins, β-casein, even in the absence of prolactin. Our results show that contact with ECM plays an important role in the lactogenic activity of bovine MECs, however, prolactin is necessary for the efficient secretion of milk proteins.


2005 ◽  
Vol 288 (5) ◽  
pp. C1042-C1047 ◽  
Author(s):  
Shannon L. Kelleher ◽  
Bo Lönnerdal

During lactation, a substantial amount of Zn2+ is transferred by the mammary gland from the maternal circulation into milk; thus secretory mammary epithelial cells must tightly regulate Zn2+ transport to ensure optimal Zn2+ transfer to the suckling neonate. To date, six Zn2+ import proteins (Zip1–6) have been identified; however, Zip3 expression is restricted to tissues with unique requirements for Zn2+, such as the mammary gland, which suggests that it may play a specialized role in this tissue. In the present study, we have used a unique mammary epithelial cell model (HC11) to characterize the role of Zip3 in mammary epithelial cell Zn2+ transport. Confocal microscopy demonstrated that Zip3 is localized to the cell surface in mammary epithelial cells and transiently relocalized to an intracellular compartment in cells with a secretory phenotype. Total 65Zn transport was higher in secreting cells, while gene silencing of Zip3 decreased 65Zn uptake into mammary epithelial cells, particularly in those with a secretory phenotype. Finally, reduced expression of Zip3 ultimately resulted in cell death, indicating that mammary epithelial cells have a unique requirement for Zip3-mediated Zn2+ import, which may reflect the unique requirement for Zn2+ of this highly specialized cell type and thus provides a physiological explanation for the restricted tissue distribution of this Zn2+ importer.


1998 ◽  
Vol 140 (1) ◽  
pp. 159-169 ◽  
Author(s):  
Yohei Hirai ◽  
André Lochter ◽  
Sybille Galosy ◽  
Shogo Koshida ◽  
Shinichiro Niwa ◽  
...  

Hepatocyte growth factor (HGF) and EGF have been reported to promote branching morphogenesis of mammary epithelial cells. We now show that it is epimorphin that is primarily responsible for this phenomenon. In vivo, epimorphin was detected in the stromal compartment but not in lumenal epithelial cells of the mammary gland; in culture, however, a subpopulation of mammary epithelial cells produced significant amounts of epimorphin. When epimorphin-expressing epithelial cell clones were cultured in collagen gels they displayed branching morphogenesis in the presence of HGF, EGF, keratinocyte growth factor, or fibroblast growth factor, a process that was inhibited by anti-epimorphin but not anti-HGF antibodies. The branch length, however, was roughly proportional to the ability of the factors to induce growth. Accordingly, epimorphin-negative epithelial cells simply grew in a cluster in response to the growth factors and failed to branch. When recombinant epimorphin was added to these collagen gels, epimorphin-negative cells underwent branching morphogenesis. The mode of action of epimorphin on morphogenesis of the gland, however, was dependent on how it was presented to the mammary cells. If epimorphin was overexpressed in epimorphin-negative epithelial cells under regulation of an inducible promoter or was allowed to coat the surface of each epithelial cell in a nonpolar fashion, the cells formed globular, alveoli-like structures with a large central lumen instead of branching ducts. This process was enhanced also by addition of HGF, EGF, or other growth factors and was inhibited by epimorphin antibodies. These results suggest that epimorphin is the primary morphogen in the mammary gland but that growth factors are necessary to achieve the appropriate cell numbers for the resulting morphogenesis to be visualized.


2017 ◽  
Author(s):  
Reetta Virtakoivu ◽  
Emilia Peuhu ◽  
Anja Mai ◽  
Anni Wärri ◽  
Johanna Ivaska

AbstractIn the mammary gland, vimentin intermediate filaments are expressed in stromal cells and in basal epithelial cell populations including gland-reconstituting mammary stem cells (MaSC), with largely undefined functions. Here, we studied how vimentin deficiency affects mouse mammary gland development. Our results demonstrate that in adult vimentin knockout mice (Vim-/-) mammary ductal outgrowth is delayed. The adult Vim-/- glands are characterised by dilated ducts, an imbalance in the proportion of basal to luminal mammary epithelial cells and a reduction in cells expressing Slug (Snai2), an established MaSC regulator. All of these features are indicative of reduced progenitor cell activity. Accordingly, isolated Vim-/- mammary epithelial cells display reduced capacity to form mammospheres, and altered organoid structure, compared to wt counterparts, when plated in a 3D matrix in vitro. Importantly, altered basal epithelial cell number translates into defects in Vim-/- mammary gland regeneration in vivo in cleared fat pad transplantation studies. Furthermore, we show that vimentin contributes to stem-like cell properties in triple negative MDA-MB-231 breast cancer cells, wherein vimentin depletion reduces tumorsphere formation and alters expression of breast cancer stem cell-associated surface markers. Together, our findings identify vimentin as a positive regulator of stemness in the developing mouse mammary gland and in breast cancer cells.


1993 ◽  
Vol 4 (8) ◽  
pp. 849-858 ◽  
Author(s):  
J Kirjavainen ◽  
S Leppä ◽  
N E Hynes ◽  
M Jalkanen

A cell surface proteoglycan, syndecan-1, has been shown to participate in the maintenance of the epithelial cell morphology. A point mutated activated c-Ha-ras gene under the control of the glucocorticoid inducible MMTV-LTR promoter was transfected into the mouse mammary epithelial cell line, NOG-8. The NOG-8 ras cells were used to study changes in syndecan-1 expression during epithelial transformation. NOG-8 ras cells, when induced to express Ha-ras, transformed and formed foci in monolayer cultures and colonies in suspension cultures. Expression of syndecan-1 at the cell surface was markedly reduced in cells showing the transformed phenotype. The accumulation of newly synthesized core protein of syndecan-1 was suppressed in these cells, whereas mRNA levels remained unchanged. This novel finding indicates that syndecan-1 expression is translationally suppressed in the Ha-ras-transformed epithelial cells. Hence, syndecan-1 loss during epithelial transformation could take place without altering syndecan gene transcription and, on the other hand, could be one of the critical events involved in malignant transformation.


2000 ◽  
Vol 20 (23) ◽  
pp. 9092-9101 ◽  
Author(s):  
Ratna K. Vadlamudi ◽  
Rui-An Wang ◽  
Amjad H. Talukder ◽  
Liana Adam ◽  
Randy Johnson ◽  
...  

ABSTRACT Heregulin β1 (HRG), a combinatorial ligand for human growth factor receptors 3 and 4, is a regulatory polypeptide that promotes the differentiation of mammary epithelial cells into secretory lobuloalveoli. Emerging evidence suggests that the processes of secretory pathways, such as biogenesis and trafficking of vesicles in neurons and adipose cells, are regulated by the Rab family of low-molecular-weight GTPases. In this study, we identified Rab3A as a gene product induced by HRG. Full-length Rab3A was cloned from a mammary gland cDNA library. We demonstrated that HRG stimulation of human breast cancer cells and normal breast epithelial cells induces the expression of Rab3A protein and mRNA in a cycloheximide-independent manner. HRG-mediated induction of Rab3A expression was blocked by an inhibitor of phosphatidylinositol 3-kinase but not by inhibitors of mitogen-activated protein kinases p38MAPK and p42/44MAPK. Human breast epithelial cells also express other components of regulated vesicular traffic, such as rabphilin 3A, Doc2, and syntaxin. Rab3A was predominantly localized in the cytosol, and HRG stimulation of the epithelial cells also raised the level of membrane-bound Rab3A. HRG treatment induced a profound alteration in the cell morphology in which cells displayed neuron-like membrane extensions that contained Rab3A-coated, vesicle-like structures. In addition, HRG also promoted the secretion of cellular proteins from the mammary epithelial cells. The ability of HRG to modify exocytosis was verified by using a growth hormone transient-transfection system. Analysis of mouse mammary gland development revealed the expression of Rab3A in mammary epithelial cells. Furthermore, expression of the HRG transgene in Harderian tumors in mice also enhanced the expression of Rab3A. These observations provide new evidence of the existence of a Rab3A pathway in mammary epithelial cells and suggest that it may play a role in vesicle trafficking and secretion of proteins from epithelial cells in response to stimulation by the HRG expressed within the mammary mesenchyma.


2008 ◽  
Vol 22 (12) ◽  
pp. 2677-2688 ◽  
Author(s):  
Paul G. Tiffen ◽  
Nader Omidvar ◽  
Nuria Marquez-Almuina ◽  
Dawn Croston ◽  
Christine J. Watson ◽  
...  

Abstract Recent studies in breast cancer cell lines have shown that oncostatin M (OSM) not only inhibits proliferation but also promotes cell detachment and enhances cell motility. In this study, we have looked at the role of OSM signaling in nontransformed mouse mammary epithelial cells in vitro using the KIM-2 mammary epithelial cell line and in vivo using OSM receptor (OSMR)-deficient mice. OSM and its receptor were up-regulated approximately 2 d after the onset of postlactational mammary regression, in response to leukemia inhibitory factor (LIF)-induced signal transducer and activator of transcription-3 (STAT3). This resulted in sustained STAT3 activity, increased epithelial apoptosis, and enhanced clearance of epithelial structures during the remodeling phase of mammary involution. Concurrently, OSM signaling precipitated the dephosphorylation of STAT5 and repressed expression of the milk protein genes β-casein and whey acidic protein (WAP). Similarly, during pregnancy, OSM signaling suppressed β-casein and WAP gene expression. In vitro, OSM but not LIF persistently down-regulated phosphorylated (p)-STAT5, even in the continued presence of prolactin. OSM also promoted the expression of metalloproteinases MMP3, MMP12, and MMP14, which, in vitro, were responsible for OSM-specific apoptosis. Thus, the sequential activation of IL-6-related cytokines during mammary involution culminates in an OSM-dependent repression of epithelial-specific gene expression and the potentiation of epithelial cell extinction mediated, at least in part, by the reciprocal regulation of p-STAT5 and p-STAT3.


1983 ◽  
Vol 3 (6) ◽  
pp. 982-990
Author(s):  
N S Yang ◽  
C Park ◽  
C Longley ◽  
P Furmanski

Multiple molecular forms of plasminogen activator were detected in normal human mammary epithelial cells in culture. Cells derived from (normal) breast mammoplasty specimens and grown on the surface of collagen gels exhibited three major classes of plasminogen activator isozymes (Mr = 100,000 [100K], 75,000 [75K], and 55,000 [55K]). The activity of the 100K and 75K isozymes was greatly reduced when the cells were grown on conventional tissue-culture-grade plastic surfaces. MCF-7, a human mammary carcinoma cell line, exhibited predominantly or exclusively the 55K isozyme, irrespective of the cell growth substratum. The activity of the 55K isozyme was more than twofold higher for MCF-7 cells grown on collagen gels than for cells grown on plastic. Progesterone, diethylstilbestrol, and estrogen stimulated the activity of the 55K isozyme of MCF-7 cells, but only when the cells were grown on a plastic surface. The plasminogen activator activities of the normal human mammary epithelial cells were not stimulated by these hormones, irrespective of the growth substratum. These results show that the expression of plasminogen activator isozymes by human mammary epithelial cells is subject to modulation by the extracellular matrix. Normal and malignant cells may differ in their responsiveness to these effects.


2021 ◽  
pp. 105367
Author(s):  
Peerzada Tajamul Mumtaz ◽  
Qamar Taban ◽  
Basharat Bhat ◽  
Syed Mudasir Ahmad ◽  
Mashooq Ahmad Dar ◽  
...  

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