scholarly journals Epimorphin Functions as a Key Morphoregulator for Mammary Epithelial Cells

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.

Development ◽  
2001 ◽  
Vol 128 (16) ◽  
pp. 3117-3131 ◽  
Author(s):  
Marina Simian ◽  
Yohei Hirai ◽  
Marc Navre ◽  
Zena Werb ◽  
Andre Lochter ◽  
...  

The mammary gland develops its adult form by a process referred to as branching morphogenesis. Many factors have been reported to affect this process. We have used cultured primary mammary epithelial organoids and mammary epithelial cell lines in three-dimensional collagen gels to elucidate which growth factors, matrix metalloproteinases (MMPs) and mammary morphogens interact in branching morphogenesis. Branching stimulated by stromal fibroblasts, epidermal growth factor, fibroblast growth factor 7, fibroblast growth factor 2 and hepatocyte growth factor was strongly reduced by inhibitors of MMPs, indicating the requirement of MMPs for three-dimensional growth involved in morphogenesis. Recombinant stromelysin 1/MMP3 alone was sufficient to drive branching in the absence of growth factors in the organoids. Plasmin also stimulated branching; however, plasmin-dependent branching was abolished by both inhibitors of plasmin and MMPs, suggesting that plasmin activates MMPs. To differentiate between signals for proliferation and morphogenesis, we used a cloned mammary epithelial cell line that lacks epimorphin, an essential mammary morphogen. Both epimorphin and MMPs were required for morphogenesis, but neither was required for epithelial cell proliferation. These results provide direct evidence for a crucial role of MMPs in branching in mammary epithelium and suggest that, in addition to epimorphin, MMP activity is a minimum requirement for branching morphogenesis in the mammary gland.


2000 ◽  
pp. 199-226 ◽  
Author(s):  
D S Saloman ◽  
C Bianco ◽  
A D Ebert ◽  
N I Khan ◽  
M De Santis ◽  
...  

The EGF-CFC gene family encodes a group of structurally related proteins that serve as important competence factors during early embryogenesis in Xenopus, zebrafish, mice and humans. This multigene family consists of Xenopus FRL-1, zebrafish one-eyed-pinhead (oep), mouse cripto (Cr-1) and cryptic, and human cripto (CR-1) and criptin. FRL-1, oep and mouse cripto are essential for the formation of mesoderm and endoderm and for correct establishment of the anterior/posterior axis. In addition, oep and cryptic are important for the establishment of left-right (L/R) asymmetry. In zebrafish, there is strong genetic evidence that oep functions as an obligatory co-factor for the correct signaling of a transforming growth factor-beta (TGFbeta)-related gene, nodal, during gastrulation and during L/R asymmetry development. Expression of Cr-1 and cryptic is extinguished in the embryo after day 8 of gestation except for the developing heart where Cr-1 expression is necessary for myocardial development. In the mouse, cryptic is not expressed in adult tissues whereas Cr-1 is expressed at a low level in several different tissues including the mammary gland. In the mammary gland, expression of Cr-1 in the ductal epithelial cells increases during pregnancy and lactation and immunoreactive and biologically active Cr-1 protein can be detected in human milk. Overexpression of Cr-1 in mouse mammary epithelial cells can facilitate their in vitro transformation and in vivo these Cr-1-transduced cells produce ductal hyperplasias in the mammary gland. Recombinant mouse or human cripto can enhance cell motility and branching morphogenesis in mammary epithelial cells and in some human tumor cells. These effects are accompanied by an epithelial-mesenchymal transition which is associated with a decrease in beta-catenin function and an increase in vimentin expression. Expression of cripto is increased several-fold in human colon, gastric, pancreatic and lung carcinomas and in a variety of different types of mouse and human breast carcinomas. More importantly, this increase can first be detected in premalignant lesions in some of these tissues. Although a specific receptor for the EGF-CFC proteins has not yet been identified, oep depends upon an activin-type RIIB and RIB receptor system that functions through Smad-2. Mouse and human cripto have been shown to activate a ras/raf/MAP kinase signaling pathway in mammary epithelial cells. Activation of phosphatidylinositol 3-kinase and Akt are also important for the ability of CR-1 to stimulate cell migration and to block lactogenic hormone-induced expression of beta-casein and whey acidic protein. In mammary epithelial cells, part of these responses may depend on the ability of CR-1 to transactivate erb B-4 and/or fibroblast growth factor receptor 1 through an src-like tyrosine kinase.


1994 ◽  
Vol 107 (12) ◽  
pp. 3557-3568 ◽  
Author(s):  
F. Berdichevsky ◽  
D. Alford ◽  
B. D'Souza ◽  
J. Taylor-Papadimitriou

To study the morphogenesis of human epithelial cells in vitro we have used a three-dimensional collagen matrix and a newly developed mammary epithelial cell line, 1–7 HB2. In standard medium 1–7 HB2 cells formed compact balls/spheres inside collagen type I gels, while cocultivation with various fibroblast cell lines or growth in fibroblast-conditioned media resulted in the appearance of branching structures. At least two different soluble factors secreted by fibroblasts were found to be implicated in the branching morphogenesis. Firstly, hepatocyte growth factor/scatter factor could induce branching in a concentration-dependent manner. Moreover, a polyclonal serum against hepatocyte growth factor/scatter factor completely inhibited the branching morphogenesis induced by medium conditioned by MRC-5 fibroblast cells. In contrast, a morphogenetic activity secreted by human foreskin fibroblasts was identified that appears to be different from hepatocyte growth factor/scatter factor and from a number of other well-characterized growth factors or cytokines. This model system has been used to examine the role of integrins in mammary morphogenesis. The expression of the alpha 2 beta 1, alpha 3 beta 1 and alpha 6 beta 4 integrins was decreased when cells were plated on collagen gels. The addition of specific blocking monoclonal antibodies directed to the alpha 2- and beta 1-integrin subunits to growth media impaired cell-cell interactions and interfered with the formation of compact structures inside collagen gels, suggesting that the alpha 2 beta 1 integrin can control intercellular adhesion in mammary morphogenesis. In contrast one of the blocking monoclonal antibodies against the alpha 3-integrin subunit (P1B5) mimicked the effect of soluble ‘morphogens’. Our results suggest that the modulation of alpha 3 beta 1 activity may represent an important event in the induction of branching morphogenesis of human mammary epithelial cells.


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.


1997 ◽  
Vol 110 (1) ◽  
pp. 55-63 ◽  
Author(s):  
S. Stahl ◽  
S. Weitzman ◽  
J.C. Jones

In vivo, normal mammary epithelial cells utilize hemidesmosome attachment devices to adhere to stroma. However, analyses of a potential role for hemidesmosomes and their components in mammary epithelial tissue morphogenesis have never been attempted. MCF-10A cells are a spontaneously immortalized line derived from mammary epithelium and possess a number of characteristics of normal mammary epithelial cells including expression of hemidesmosomal associated proteins such as the two bullous pemphigoid antigens, alpha 6 beta 4 integrin and its ligand laminin-5. More importantly, MCF-10A cells readily assemble mature hemidesmosomes when plated onto uncoated substrates. When maintained on matrigel, like their normal breast epithelial cell counterparts, MCF-10A cells undergo a branching morphogenesis and assemble hemidesmosomes at sites of cell-matrigel interaction. Function blocking antibodies specific for human laminin-5 and the alpha subunits of its two known receptors (alpha 3 beta 1 and alpha 6 beta 4 integrin) not only inhibit hemidesmosome assembly by MCF-10A cells but also impede branching morphogenesis induced by matrigel. Our results imply that the hemidesmosome, in particular those subunits comprising its laminin-5/integrin ‘backbone’, play an important role in morphogenetic events. We discuss these results in light of recent evidence that hemidesmosomes are sites involved in signal transduction.


2002 ◽  
Vol 22 (8) ◽  
pp. 2586-2597 ◽  
Author(s):  
Caterina Bianco ◽  
Heather B. Adkins ◽  
Christian Wechselberger ◽  
Masaharu Seno ◽  
Nicola Normanno ◽  
...  

ABSTRACT Cripto-1 (CR-1), an epidermal growth factor-CFC (EGF-CFC) family member, has a demonstrated role in embryogenesis and mammary gland development and is overexpressed in several human tumors. Recently, EGF-CFC proteins were implicated as essential signaling cofactors for Nodal, a transforming growth factor β family member whose expression has previously been defined as embryo specific. To identify a receptor for CR-1, a human brain cDNA phage display library was screened using CR-1 protein as bait. Phage inserts with identity to ALK4, a type I serine/threonine kinase receptor for Activin, were identified. CR-1 binds to cell surface ALK4 expressed on mammalian epithelial cells in fluorescence-activated cell sorter analysis, as well as by coimmunoprecipitation. Nodal is coexpressed with mouse Cr-1 in the mammary gland, and CR-1 can phosphorylate the transcription factor Smad-2 in EpH-4 mammary epithelial cells only in the presence of Nodal and ALK4. In contrast, CR-1 stimulation of mitogen-activated protein kinase and AKT in these cells is independent of Nodal and ALK4, suggesting that CR-1 may modulate different signaling pathways to mediate its different functional roles.


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.


Development ◽  
1998 ◽  
Vol 125 (7) ◽  
pp. 1285-1294 ◽  
Author(s):  
J.J. Wysolmerski ◽  
W.M. Philbrick ◽  
M.E. Dunbar ◽  
B. Lanske ◽  
H. Kronenberg ◽  
...  

Parathyroid hormone-related protein (PTHrP) was originally discovered as a tumor product that causes humoral hypercalcemia of malignancy. PTHrP is now known to be widely expressed in normal tissues and growing evidence suggests that it is an important developmental regulatory molecule. We had previously reported that overexpression of PTHrP in the mammary glands of transgenic mice impaired branching morphogenesis during sexual maturity and early pregnancy. We now demonstrate that PTHrP plays a critical role in the epithelial-mesenchymal communications that guide the initial round of branching morphogenesis that occurs during the embryonic development of the mammary gland. We have rescued the PTHrP-knockout mice from neonatal death by transgenic expression of PTHrP targeted to chondrocytes. These rescued mice are devoid of mammary epithelial ducts. We show that disruption of the PTHrP gene leads to a failure of the initial round of branching growth that is responsible for transforming the mammary bud into the rudimentary mammary duct system. In the absence of PTHrP, the mammary epithelial cells degenerate and disappear. The ability of PTHrP to support embryonic mammary development is a function of amino-terminal PTHrP, acting via the PTH/PTHrP receptor, for ablation of the PTH/PTHrP receptor gene recapitulates the phenotype of PTHrP gene ablation. We have localized PTHrP expression to the embryonic mammary epithelial cells and PTH/PTHrP receptor expression to the mammary mesenchyme using in situ hybridization histochemistry. Finally, we have rescued mammary gland development in PTHrP-null animals by transgenic expression of PTHrP in embryonic mammary epithelial cells. We conclude that PTHrP is a critical epithelial signal received by the mammary mesenchyme and involved in supporting the initiation of branching morphogenesis.


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