scholarly journals Purinergic receptor (P2X7) activation reduces cell–cell adhesion between tubular epithelial cells of the proximal kidney

2019 ◽  
Vol 22 ◽  
pp. 102108 ◽  
Author(s):  
Eleftherios Siamantouras ◽  
Gareth W. Price ◽  
Joe A. Potter ◽  
Claire E. Hills ◽  
Paul E. Squires
Development ◽  
1989 ◽  
Vol 105 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Y. Hirai ◽  
A. Nose ◽  
S. Kobayashi ◽  
M. Takeichi

The role of Ca2+-dependent cell-cell adhesion molecules, E- and P-cadherins, in the histogenesis of mouse embryonic lung was studied. All epithelial cells of the lung express both E- and P-cadherin at the early developmental stage. P-cadherin, however, gradually disappears during development, initially from the main bronchi and eventually from all epithelial cells. When a monoclonal antibody to E-cadherin (ECCD-1) was added to monolayer cultures of lung epithelial cells, it induced a partial disruption of their cell-cell adhesion, while a monoclonal antibody to P-cadherin (PCD-1) showed a subtle effect. A mixture of the two antibodies, however, displayed a synergistic effect. We then tested the effect of the antibodies on the morphogenesis of lung primordia using an organ culture system. In control media, the explants formed typical bronchial trees. In the presence of ECCD-1, the explants grew up at the same rate as in the control, but their morphogenesis was affected. The control explants formed round epithelial lobules with an open luminal space at the tips of the bronchial trees, whereas the lobules of explants incubated with ECCD-1 tended to be flat and devoid of the luminal space. PCD-1 showed a similar but very small effect. A mixture of the two antibodies, however, showed a stronger effect: the branching of epithelia was partially suppressed and the arrangement of epithelial cells was distorted in many places. These results suggest that E- and P-cadherin have a synergistic role in the organization of epithelial cells in lung morphogenesis.


1998 ◽  
Vol 9 (11) ◽  
pp. 3161-3177 ◽  
Author(s):  
Peter A. Piepenhagen ◽  
W. James Nelson

Organization of proteins into structurally and functionally distinct plasma membrane domains is an essential characteristic of polarized epithelial cells. Based on studies with cultured kidney cells, we have hypothesized that a mechanism for restricting Na/K-ATPase to the basal-lateral membrane involves E-cadherin–mediated cell–cell adhesion and integration of Na/K-ATPase into the Triton X-100–insoluble ankyrin- and spectrin-based membrane cytoskeleton. In this study, we examined the relevance of these in vitro observations to the generation of epithelial cell polarity in vivo during mouse kidney development. Using differential detergent extraction, immunoblotting, and immunofluorescence histochemistry, we demonstrate the following. First, expression of the 220-kDa splice variant of ankyrin-3 correlates with the development of resistance to Triton X-100 extraction for Na/K-ATPase, E-cadherin, and catenins and precedes maximal accumulation of Na/K-ATPase. Second, expression of the 190-kDa slice variant of ankyrin-3 correlates with maximal accumulation of Na/K-ATPase. Third, Na/K-ATPase, ankyrin-3, and fodrin specifically colocalize at the basal-lateral plasma membrane of all epithelial cells in which they are expressed and during all stages of nephrogenesis. Fourth, the relative immunofluorescence staining intensities of Na/K-ATPase, ankyrin-3, and fodrin become more similar during development until they are essentially identical in adult kidney. Thus, renal epithelial cells in vivo regulate the accumulation of E-cadherin–mediated adherens junctions, the membrane cytoskeleton, and Na/K-ATPase through sequential protein expression and assembly on the basal-lateral membrane. These results are consistent with a mechanism in which generation and maintenance of polarized distributions of these proteins in vivo and in vitro involve cell–cell adhesion, assembly of the membrane cytoskeleton complex, and concomitant integration and retention of Na/K-ATPase in this complex.


1994 ◽  
Vol 267 (4) ◽  
pp. F612-F623
Author(s):  
E. E. Simon ◽  
C. H. Liu ◽  
M. Das ◽  
S. Nigam ◽  
T. J. Broekelmann ◽  
...  

We have characterized the integrins present on cultured tubule epithelial cells from human renal cortexes, enriched for proximal cells, using fluorescence microscopy, immunoprecipitation, and cell adhesion assays. By immunofluorescence, the alpha 3-integrin subunit stained most intensely and was present on all cells predominantly at cell-cell contacts. The alpha 6-subunit was present on all cells in a pattern consistent with extracellular matrix contacts. The alpha 5-subunit was present on most cells in a cell-matrix contact pattern; alpha V-subunit was weakly positive and occasionally seen in cell-matrix contacts. The alpha 2-subunit was present on clusters of distal tubule cells, predominantly at cell-cell contacts. Immunoprecipitation revealed the predominant integrin to be alpha 3 beta 1 with some alpha 2 beta 1, presumably contributed by distal cells. The alpha 5 beta 1-, alpha 6 beta 1-, alpha 6 beta 4-, and alpha V beta 3-integrins, as well as trace amounts of alpha 1 beta 1-integrins, were also present. The alpha 4 beta 1-integrin was not detected. Initial attachment to fibronectin was mediated by alpha V beta 3- and alpha 5 beta 1-integrins; initial attachment to laminin was mediated by the alpha 6 beta 1- and alpha 3 beta 1- integrins and, in some preparations, by an unidentified integrin; and initial attachment to collagen type IV was mediated by alpha V beta 3-integrin and an unidentified beta 1-integrin. After extensively immunodepleting membrane extracts with anti-alpha 1, -alpha 2, -alpha 3, -alpha 4, -alpha 5, -alpha 6, and -alpha V antibodies, an anti-beta 1 antibody still precipitated an integrin. Its electrophoretic mobility differs from the laminin-binding alpha 7 beta 1-integrin. Thus we have identified many of the integrins on cortical tubule cells and their role in mediating initial attachment to extracellular matrix. However, the cell adhesion assays and immunoprecipitations suggest the presence of an unidentified beta 1-integrin that may mediate renal tubule cell attachment to laminin and collagen.


2004 ◽  
Vol 166 (3) ◽  
pp. 393-405 ◽  
Author(s):  
Tatsuro Fukuhara ◽  
Kazuya Shimizu ◽  
Tomomi Kawakatsu ◽  
Taihei Fukuyama ◽  
Yukiko Minami ◽  
...  

Nectins, Ca2+-independent immunoglobulin-like cell–cell adhesion molecules, initiate cell–cell adhesion by their trans interactions and recruit cadherins to cooperatively form adherens junctions (AJs). In addition, the trans interactions of nectins induce the activation of Cdc42 and Rac small G proteins, which increases the velocity of the formation of AJs. We examined here how nectins induce the activation of Cdc42 in MDCK epithelial cells and L fibroblasts. Nectins recruited and activated c-Src at the nectin-based cell–cell adhesion sites. FRG, a GDP/GTP exchange factor specific for Cdc42, was then recruited there, tyrosine phosphorylated by c-Src, and activated, causing an increase in the GTP-bound active form of Cdc42. Inhibition of the nectin-induced activation of c-Src suppressed the nectin-induced activation of FRG and Cdc42. Inhibition of the nectin-induced activation of FRG or depletion of FRG by RNA interference suppressed the nectin-induced activation of Cdc42. These results indicate that nectins induce the activation of Cdc42 through c-Src and FRG locally at the nectin-based cell–cell adhesion sites.


2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Kieran Brennan ◽  
Gozie Offiah ◽  
Elaine A. McSherry ◽  
Ann M. Hopkins

Breast cancer is a complex and heterogeneous disease that arises from epithelial cells lining the breast ducts and lobules. Correct adhesion between adjacent epithelial cells is important in determining the normal structure and function of epithelial tissues, and there is accumulating evidence that dysregulated cell-cell adhesion is associated with many cancers. This review will focus on one cell-cell adhesion complex, the tight junction (TJ), and summarize recent evidence that TJs may participate in breast cancer development or progression. We will first outline the protein composition of TJs and discuss the functions of the TJ complex. Secondly we will examine how alterations in these functions might facilitate breast cancer initiation or progression; by focussing on the regulatory influence of TJs on cell polarity, cell fate and cell migration. Finally we will outline how pharmacological targeting of TJ proteins may be useful in limiting breast cancer progression. Overall we hope to illustrate that the relationship between TJ alterations and breast cancer is a complex one; but that this area offers promise in uncovering fundamental mechanisms linked to breast cancer progression.


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