Rescue of the parathyroid hormone-related protein knockout mouse demonstrates that parathyroid hormone-related protein is essential for mammary gland development

Development ◽  
1998 ◽  
Vol 125 (7) ◽  
pp. 1285-1294 ◽  
Author(s):  
J.J. Wysolmerski ◽  
W.M. Philbrick ◽  
M.E. Dunbar ◽  
B. Lanske ◽  
H. Kronenberg ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Branching Morphogenesis ◽  
Mammary Epithelial ◽  
Related Protein ◽  
Transgenic Expression ◽  
Parathyroid Hormone Related Protein ◽  
Pthrp Receptor

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.

Parathyroid hormone-related protein increases cAMP production in mammary epithelial cells

1993 ◽  
Vol 264 (3) ◽  
pp. E471-E475 ◽  
Author(s):  
S. Ferrari ◽  
R. Rizzoli ◽  
C. Chaponnier ◽  
G. Gabbiani ◽  
J. P. Bonjour
Keyword(s):  
Parathyroid Hormone ◽  
Epithelial Cells ◽  
Breast Tissue ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Immunofluorescent Staining ◽  
Regulatory Function ◽  
Related Protein ◽  
Camp Production ◽  
Parathyroid Hormone Related Protein

Parathyroid hormone-related protein (PTHrP) is a major cause of malignant hypercalcemia but has been found in many nontumoral tissues as well. Thus it is produced by the mammary gland during lactation and released into milk. Whether PTHrP directly affects breast tissue is however not known. We investigated the effects of PTHrP on adenosine 3',5'-cyclic monophosphate (cAMP) production in primary cultures of mammary epithelial cells isolated from lactating rats. On the 7th day in culture, synthetic PTHrP-(1-34), recombinant (r) PTHrP-(1-108), and rPTHrP-(1-141) stimulated cAMP production in a concentration-dependent manner. Thus PTHrP-(1-34) induced a 1.92 +/- 0.04-fold stimulation of cAMP production (mean +/- SE, n = 5 separate experiments, P < 0.001). At the time of maximal responsiveness to PTHrP, a significant proportion of the cells was characterized by an elongated shape and a positive immunofluorescent staining for both prekeratin and alpha-smooth muscle actin 1, compatible with a myoepithelial phenotype. It therefore appears that PTHrP can stimulate the production of cAMP in mammary cells, suggesting a possible autocrine/paracrine regulatory function for PTHrP in breast tissue.

Parathyroid hormone-related protein maintains mammary epithelial fate and triggers nipple skin differentiation during embryonic breast development

Development ◽  
2001 ◽  
Vol 128 (4) ◽  
pp. 513-525 ◽  
Author(s):  
J. Foley ◽  
P. Dann ◽  
J. Hong ◽  
J. Cosgrove ◽  
B. Dreyer ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Epithelial Cells ◽  
Cell Fate ◽  
Mesenchymal Cells ◽  
Mammary Development ◽  
Mammary Epithelial ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Mammary Mesenchyme ◽  
Pthrp Receptor

Prior reports have demonstrated that both parathyroid hormone-related protein (PTHrP) and the type I PTH/PTHrP receptor are necessary for the proper development of the embryonic mammary gland in mice. Using a combination of loss-of-function and gain-of-function models, we now report that PTHrP regulates a series of cell fate decisions that are central to the survival and morphogenesis of the mammary epithelium and the formation of the nipple. PTHrP is made in the epithelial cells of the mammary bud and, during embryonic mammary development, it interacts with the surrounding mesenchymal cells to induce the formation of the dense mammary mesenchyme. In response, these mammary-specific mesenchymal cells support the maintenance of mammary epithelial cell fate, trigger epithelial morphogenesis and induce the overlying epidermis to form the nipple. In the absence of PTHrP signaling, the mammary epithelial cells revert to an epidermal fate, no mammary ducts are formed and the nipple does not form. In the presence of diffuse epidermal PTHrP signaling, the ventral dermis is transformed into mammary mesenchyme and the entire ventral epidermis becomes nipple skin. These alterations in cell fate require that PTHrP be expressed during development and they require the presence of the PTH/PTHrP receptor. Finally, PTHrP signaling regulates the epidermal and mesenchymal expression of LEF1 and (β)-catenin, suggesting that these changes in cell fate involve an interaction between the PTHrP and Wnt signaling pathways.

Cortisol, parathyroid hormone-related protein and the onset of calcium secretion by the mammary gland of the goat

1997 ◽  
Vol 64 (4) ◽  
pp. 633-636
Author(s):  
GORDON E. THOMPSON ◽  
S. KHAWAR ABBAS ◽  
CARL HOLT ◽  
ANTHONY D. CARE
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Epithelial Cells ◽  
Tight Junctions ◽  
Calcium Transport ◽  
Extracellular Fluid ◽  
Secretory Cells ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Calcium Secretion

During lactogenesis in the goat, the onset of secretion of calcium into milk occurs at parturition (Thompson et al. 1995) at approximately the same time as the onset of secretion of parathyroid hormone-related protein (PTHrP) by the mammary gland (Ratcliffe et al. 1992); these events may be unrelated or PTHrP may be involved in calcium transport from blood to milk.Parturition in goats is initiated by fetal secretion of cortisol (Flint et al. 1978) and maternal secretion of cortisol also increases (Paterson & Linzell, 1971). Injecting cortisol locally into the sinus of a mammary gland of the late-pregnant goat when the tight junctions between secretory epithelial cells appear to be ‘loose’, and injectate can reach the basolateral surfaces of secretory cells, stimulates an early tightening of these junctions (Thompson, 1996) as occurs naturally at parturition. This tightening can be produced by an increased concentration of ionized calcium in the extracellular fluid of the gland (Neville & Peaker, 1981).The experiments reported here were undertaken to determine if cortisol injection stimulates the mammary gland to secrete both PTHrP and calcium before parturition.

The EGF-CFC family: novel epidermal growth factor-related proteins in development and cancer.

2000 ◽  
pp. 199-226 ◽  
Author(s):  
D S Saloman ◽  
C Bianco ◽  
A D Ebert ◽  
N I Khan ◽  
M De Santis ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Branching Morphogenesis ◽  
Mammary Epithelial ◽  
Biologically Active ◽  
Beta Catenin ◽  
Mesenchymal Transition ◽  
Related Proteins

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.

Stromal and epithelial cells of the canine prostate express parathyroid hormone-related protein, but not the PTH/PTHrP receptor

The Prostate ◽  
1998 ◽  
Vol 36 (2) ◽  
pp. 110-120 ◽  
Author(s):  
Eric A.G. Blomme ◽  
Yasuro Sugimoto ◽  
Laurie K. McCauley ◽  
Young C. Lin ◽  
Charles C. Capen ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Epithelial Cells ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Pthrp Receptor

scholarly journals Understanding mammary gland functioning in livestock species using in-vitro mammary epithelial cells model -An overview

2013 ◽  
Vol 3 (1) ◽  
pp. 160-168
Author(s):  
M Mukesh ◽  
Umesh Kumar Shandilya ◽  
Monika Sodhi ◽  
Ankita Sharma ◽  
Neha Kapila
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Cell Line ◽  
In Vitro Model ◽  
Mammary Epithelial Cells ◽  
Branching Morphogenesis ◽  
Mammary Epithelial ◽  
Livestock Species ◽  
Vitro Model

Understanding the mechanisms of the development of the mammary gland can increase the efficiency of milk production, as well as improve animal health. Mammary epithelial cells (MEC) are the functional unit of the mammary gland. Although, there is a well-established MEC cell line, known as MAC-T, the use of a primary cell line is preferred because it more closely mimics an in vivo model. This review focuses on utilization of MECs as a potential in vitro model to better understand mammary gland functions in livestock species. Recently, considerable advances in three dimensional modeling of the mammary gland have been made with the used of extracellular matrix for the study of branching morphogenesis which may enable rapid advances in our understanding of mammary gland biology. Progress in the exploitation of MECs as in vitro model is more productive than ever, however further research is vital.    

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 ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Growth Factors ◽  
Growth Factor ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Branching Morphogenesis ◽  
Mammary Epithelial ◽  
Collagen Gels ◽  
Stromal Compartment

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.

Sign in / Sign up

Export Citation Format

Share Document