Factors affecting morphogenesis of rabbit gallbladder epithelial cells cultured in collagen gels

2000 ◽  
Vol 300 (2) ◽  
pp. 331-344 ◽  
Author(s):  
Michito Mori ◽  
Kohji Miyazaki
1988 ◽  
Vol 40 (2) ◽  
pp. 123-132 ◽  
Author(s):  
Raphael C. Guzman ◽  
Rebecca C. Osborn ◽  
Jack C. Bartley ◽  
Satyabrata Nandi

1990 ◽  
Vol 110 (4) ◽  
pp. 1405-1415 ◽  
Author(s):  
C H Streuli ◽  
M J Bissell

Reconstituted basement membranes and extracellular matrices have been demonstrated to affect, positively and dramatically, the production of milk proteins in cultured mammary epithelial cells. Here we show that both the expression and the deposition of extracellular matrix components themselves are regulated by substratum. The steady-state levels of the laminin, type IV collagen, and fibronectin mRNAs in mammary epithelial cells cultured on plastic dishes and on type I collagen gels have been examined, as has the ability of these cells to synthesize, secrete, and deposit laminin and other, extracellular matrix proteins. We demonstrate de novo synthesis of a basement membrane by cells cultured on type I collagen gels which have been floated into the medium. Expression of the mRNA and proteins of basement membranes, however, are quite low in these cultures. In contrast, the levels of laminin, type IV collagen, and fibronectin mRNAs are highest in cells cultured on plastic surfaces, where no basement membrane is deposited. It is suggested that the interaction between epithelial cells and both basement membrane and stromally derived matrices exerts a negative influence on the expression of mRNA for extracellular matrix components. In addition, we show that the capacity for lactational differentiation correlates with conditions that favor the deposition of a continuous basement membrane, and argue that the interaction between specialized epithelial cells and stroma enables them to create their own microenvironment for accurate signal transduction and phenotypic function.


1998 ◽  
Vol 111 (4) ◽  
pp. 521-532 ◽  
Author(s):  
D. Alford ◽  
D. Baeckstrom ◽  
M. Geyp ◽  
P. Pitha ◽  
J. Taylor-Papadimitriou

The HB2 cell line, developed from luminal epithelial cells cultured from milk, forms ball-like structures in collagen gels which show a uniform branching response to hepatocyte growth factor. The alpha2beta1 integrin is the major integrin expressed by luminal epithelial cells, and the role of this integrin in mammary morphogenesis has been analysed using HB2 cells cultured in collagen gels and antibodies which affect integrin function. Selectivity of response was followed by comparing effects on morphogenesis in fibrin, where the alphavbeta1 integrin interacts with the matrix. In the presence of hepatocyte growth factor, using alpha2 and beta1 antibodies in collagen and alphav and beta1 antibodies in fibrin, complete blocking of the cell-matrix interaction inhibits cell survival. With partial blocking of the integrin-ligand interaction, the cells proliferate but form dissociated colonies. Activating antibodies to the beta1 integrin subunit which enhance the matrix interaction dramatically inhibit the branching and motility responses to hepatocyte growth factor. A series of non-blocking alpha2 reactive antibodies also inhibit these responses specifically in or on collagen. Studies with ras-transfected HB2 cells emphasise the importance of the alpha2beta1 collagen interaction in the development of form since HB2ras cells, which express reduced levels of the alpha2beta1 integrin, form dissociated colonies in collagen but not in fibrin. Treatment of HB2ras cells with a beta1 activating antibody, however, induces the formation of compact colonies. Even though the ras-transformants form colonies in agar, complete blocking of the alpha2beta1/collagen interaction does not allow survival in collagen. The results indicate that in mammary morphogenesis, the strength of the interaction of integrins with the extracellular matrix modulates the response to motogenic factors and contributes to the definition of form.


In Vitro ◽  
1982 ◽  
Vol 18 (3) ◽  
pp. 233-242 ◽  
Author(s):  
C. D. Logsdon ◽  
C. A. Bisbee ◽  
M. J. Rutten ◽  
T. E. Machen

1984 ◽  
Vol 98 (1) ◽  
pp. 146-155 ◽  
Author(s):  
E Y Lee ◽  
G Parry ◽  
M J Bissell

It has been shown previously that cultures of mouse mammary epithelial cells retain their characteristic morphology and their ability to produce gamma-casein, a member of the casein gene family, only if they are maintained on floating collagen gels (Emerman, J.T., and D.R. Pitelka, 1977, In Vitro, 13:316-328). In this paper we show: (a) Cells on floating collagen gels secrete not only gamma-casein but also alpha 1-, alpha 2-, and beta-caseins. These are not secreted by cells on plastic and are secreted to only a very limited extent by cells on attached collagen gels. (b) The floating collagen gel regulates at the level of synthesis and/or stabilization of the caseins rather than at the level of secretion alone. Contraction of the floating gel is important in that cells cultured on floating glutaraldehyde cross-linked gels do not secrete any of the caseins. (c) The secretion of an 80,000-mol-wt protein, most probably transferrin, and a 67,000-mol-wt protein, probably butyrophilin, a major protein of the milk fat globule membrane are partially modulated by substrata. However, in contrast to the caseins, these are always detectable in media from cells cultured on plastic and attached gels. (d) Whey acidic protein, a major whey protein, is actively secreted by freshly isolated cells but is secreted in extremely limited quantities in cultured cells regardless of the nature of the substratum used. alpha-Lactalbumin secretion is also decreased significantly in cultured cells. (e) A previously unreported set of proteins, which may be minor milk proteins, are prominently secreted by the mammary cells on all substrata tested. We conclude that while the substratum profoundly influences the secretion of the caseins, it does not regulate the expression of every milk-specific protein in the same way. The mechanistic implications of these findings are discussed.


1991 ◽  
Vol 261 (4) ◽  
pp. L255-L261 ◽  
Author(s):  
M. A. Fiedler ◽  
C. S. Kaetzel ◽  
P. B. Davis

Secretory immunoglobulin A (sIgA) is an important initial defense against environmental agents in the airway. The purposes of our study were to determine whether human tracheal epithelial (HTE) cells produce secretory component (SC), the receptor for dimeric IgA (dIgA), to determine whether HTE cells in primary culture continue to produce SC, and if so, to develop a model for studying SC metabolism in the airway. Immunoperoxidase staining of the human trachea using antibody raised against human SC reveals that many surface epithelial cells and the cells of the submucosal glands express SC but basal cells do not. HTE cells, obtained from tracheal specimens at necropsy, contain 10-51 ng of SC/10(5) cells, at the time of isolation. However, when these cells are placed in culture on plastic, SC release diminishes with time (from 19.6 ng/10(5) cells on day 2 to 6.4 on day 8) despite continued cell proliferation. In contrast, HTE cells cultured on floating collagen gels increase SC release over the same period (26.2 ng/10(5) cells on day 2 and 193.9 on day 8). HTE cells cultured on collagen-coated and uncoated nitrocellulose filters also produced SC at least through day 8 (collagen coated, 21.5 ng/10(5); uncoated, 6.3). Furthermore, SC was released preferentially to the apical surface (4:1 ratio) under both conditions. This system will allow us to study the production, processing, and release of SC by HTE cells and further understand the transport and function of secretory IgA in the airway.


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