Histopathological analysis of renal cystic epithelia in the Pkd2WS25/- mouse model of ADPKD

2003 ◽  
Vol 285 (5) ◽  
pp. F870-F880 ◽  
Author(s):  
R. Brent Thomson ◽  
SueAnn Mentone ◽  
Robert Kim ◽  
Karen Earle ◽  
Eric Delpire ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mouse Model ◽  
Cell Polarity ◽  
Late Stage ◽  
Histopathological Analysis ◽  
Cell Dedifferentiation ◽  
Cyst Cell ◽  
Autosomal Dominant Polycystic Kidney ◽  
E Cadherin

It has been proposed that autosomal dominant polycystic kidney disease (ADPKD)affected renal epithelial cells undergo a phenotypic transition from a highly differentiated absorptive state to a much less differentiated secretory state during cystogenesis and that this transition is accompanied by loss of epithelial cell polarity and mistargeting of specific membrane proteins. We conducted a detailed evaluation of this hypothesis in the Pkd2 WS25/- mouse model of ADPKD. Ultrastructural analysis of Pkd2 WS25/- cysts by electron microscopy confirmed that cystic epithelial cells progressively dedifferentiate with cyst enlargement. Immunocytochemical analysis of both early- and late-stage cysts with antibodies directed against Na+-K+-ATPase, Ksp-cadherin, and E-cadherin failed to detect evidence of altered cyst cell polarity. Na+-K+-ATPase and Ksp-cadherin were expressed exclusively on the basolateral membranes (BLM) of epithelial cells in all early cysts. Expression levels of both Na+-K+-ATPase and Ksp-cadherin decreased progressively with the degree of cyst cell dedifferentiation, but neither protein was ever mislocalized. Highly dedifferentiated cysts did not express immunodetectable levels of either Na+-K+-ATPase or Ksp-cadherin. E-cadherin was expressed prominently on the BLM of all cysts. Cysts were subsequently stained with an antibody directed against the secretory isoform of the Na+-K+-Cl- cotransporter NKCC1. NKCC1 expression was detected on the BLM of advanced cysts only. Our data are consistent with a model of progressive cystic epithelial cell dedifferentiation in which fluid accumulation in late-stage cysts is mediated by transepithelial secretion of chloride rather than secretion of sodium by apical Na+-K+-ATPase.

scholarly journals Polycystin-1 and Gα12 regulate the cleavage of E-cadherin in kidney epithelial cells

2015 ◽  
Vol 47 (2) ◽  
pp. 24-32 ◽  
Author(s):  
Jen X. Xu ◽  
Tzong-Shi Lu ◽  
Suyan Li ◽  
Yong Wu ◽  
Lai Ding ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Signaling Pathway ◽  
Cell Polarity ◽  
Mdck Cells ◽  
Adherens Junction ◽  
Renal Epithelial Cells ◽  
Extracellular Milieu ◽  
Kidney Epithelial Cells ◽  
Autosomal Dominant Polycystic Kidney ◽  
E Cadherin

Interaction of polycystin-1 (PC1) and Gα12 is important for development of kidney cysts in autosomal dominant polycystic kidney disease (ADPKD). The integrity of cell polarity and cell-cell adhesions (mainly E-cadherin-mediated adherens junction) is altered in the renal epithelial cells of ADPKD. However, the key signaling pathway for this alteration is not fully understood. Madin-Darby canine kidney (MDCK) cells maintain the normal integrity of epithelial cell polarity and adherens junctions. Here, we found that deletion of Pkd1 increased activation of Gα12, which then promoted the cystogenesis of MDCK cells. The morphology of these cells was altered after the activation of Gα12. By using liquid chromatography-mass spectrometry, we found several proteins that could be related this change in the extracellular milieu. E-cadherin was one of the most abundant peptides after active Gα12 was induced. Gα12 activation or Pkd1 deletion increased the shedding of E-cadherin, which was mediated via increased ADAM10 activity. The increased shedding of E-cadherin was blocked by knockdown of ADAM10 or specific ADAM10 inhibitor GI254023X. Pkd1 deletion or Gα12 activation also changed the distribution of E-cadherin in kidney epithelial cells and caused β-catenin to shift from cell membrane to nucleus. Finally, ADAM10 inhibitor, GI254023 X, blocked the cystogenesis induced by PC1 knockdown or Gα12 activation in renal epithelial cells. Our results demonstrate that the E-cadherin/β-catenin signaling pathway is regulated by PC1 and Gα12 via ADAM10. Specific inhibition of this pathway, especially ADAM10 activity, could be a novel therapeutic regimen for ADPKD.

scholarly journals New genomic data and analyses challenge the traditional vision of animal epithelium evolution

2017 ◽  
Author(s):  
Hassiba Belahbib ◽  
Emmanuelle Renard ◽  
Sébastien Santini ◽  
Cyril Jourda ◽  
Jean-Michel Claverie ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Polarity ◽  
Protein Complexes ◽  
Genomic Data ◽  
Genes Encoding ◽  
Interaction Domains ◽  
Unexpected Findings ◽  
Crumbs Complex ◽  
Adhesive Type ◽  
E Cadherin

AbstractThe emergence of epithelia was the foundation of metazoan expansion. To investigate the early evolution of animal epithelia, we sequenced the genome and transcriptomes of two new sponge species to characterize epithelial markers such as the E-cadherin complex and the polarity complexes for all classes (Calcarea, Demospongiae, Hexactinellida, Homoscleromorpha) of sponges (phylum Porifera) and compare them with their homologs in Placozoa and in Ctenophora. We found that Placozoa and most sponges possess orthologs of all essential genes encoding proteins characteristic of bilaterian epithelial cells, as well as their conserved interaction domains. In stark contrast, we found that ctenophores lack several major polarity complex components such as the Crumbs complex and Scribble. Furthermore, the E-cadherin ctenophore ortholog exhibits a divergent cytoplasmic domain making it unlikely to interact with its canonical cytoplasmic partners. These unexpected findings challenge the current evolutionary paradigm on the emergence of epithelia.SIGNIFICANT STATEMENTEpithelial tissues are a hallmark of metazoans deeply linked to the evolution of the complex morphogenesis processes characterizing their development. However, studies on the epithelial features of non-bilaterians are still sparse and it remains unclear whether the last common metazoan ancestor possessed a fully functional epithelial toolkit or if it was acquired later during metazoan evolution. In this work, we demonstrate that if sponges have a well conserved and functionally predicted epithelial toolkit, Ctenophores have either divergent adhesion complexes or lack essential polarity complexes. Altogether, our results raise a doubt on the homology of protein complexes and structures involved in cell polarity and adhesive type junctions between Ctenophora and Bilateria epithelia.

scholarly journals Move your microvilli

2014 ◽  
Vol 207 (1) ◽  
pp. 9-11 ◽  
Author(s):  
Robert S. Fischer
Keyword(s):  
Wound Healing ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Polarity ◽  
Apical Membrane ◽  
Apical Surface ◽  
Epithelial Cell Polarity ◽  
Cell Biol ◽  
Polarized Epithelial Cells

Polarized epithelial cells create tightly packed arrays of microvilli in their apical membrane, but the fate of these microvilli is relatively unknown when epithelial cell polarity is lost during wound healing. In this issue, Klingner et al. (2014. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201402037) show that, when epithelial cells become subconfluent, actomyosin contractions locally within the apical cortex cause their microvilli to become motile over the dorsal/apical surface. Their unexpected observations may have implications for epithelial responses in wound healing and disease.

Overexpression of the integrin-linked kinase mesenchymally transforms mammary epithelial cells

2001 ◽  
Vol 114 (6) ◽  
pp. 1125-1136 ◽  
Author(s):  
A. Somasiri ◽  
A. Howarth ◽  
D. Goswami ◽  
S. Dedhar ◽  
C.D. Roskelley
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mammary Epithelial Cell ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Cell Morphogenesis ◽  
Wild Type ◽  
Integrin Linked Kinase ◽  
E Cadherin ◽  
Cell Cell

Signals generated by the interaction of (β)1 integrins with laminin in the basement membrane contribute to mammary epithelial cell morphogenesis and differentiation. The integrin-linked kinase (ILK) is one of the signaling moieties that associates with the cytoplasmic domain of (β)1 integrin subunits with some specificity. Forced expression of a dominant negative, kinase-dead form of ILK subtly altered mouse mammary epithelial cell morphogenesis but it did not prevent differentiative milk protein expression. In contrast, forced overexpression of wild-type ILK strongly inhibited both morphogenesis and differentiation. Overexpression of wild-type ILK also caused the cells to lose the cell-cell adhesion molecule E-cadherin, become invasive, reorganize cortical actin into cytoplasmic stress fibers, and switch from an epithelial cytokeratin to a mesenchymal vimentin intermediate filament phenotype. Forced expression of E-cadherin in the latter mesenchymal cells rescued epithelial cytokeratin expression and it partially restored the ability of the cells to differentiate and undergo morphogenesis. These data demonstrate that ILK, which responds to interactions between cells and the extracellular matrix, induces a mesenchymal transformation in mammary epithelial cells, at least in part, by disrupting cell-cell junctions.

Epithelial cell polarity: what flies can teach us about cancer

2012 ◽  
Vol 53 ◽  
pp. 129-140 ◽  
Author(s):  
Daniel T. Bergstralh ◽  
Daniel St Johnston
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Polarity ◽  
Human Cancer ◽  
Fruit Fly ◽  
Model Organisms ◽  
Epithelial Cell Polarity ◽  
Energetic Stress ◽  
Evolutionarily Conserved ◽  
Cellular Machinery

Epithelial cells are polarized along their apical–basal axis. Much of the cellular machinery that goes into establishing and maintaining epithelial cell polarity is evolutionarily conserved. Model organisms, including the fruit fly, Drosophila melanogaster, are thus particularly useful for the study of cell polarity. Work in Drosophila has identified several important components of the polarity machinery and has also established the surprising existence of a secondary cell polarity pathway required only under conditions of energetic stress. This work has important implications for the understanding of human cancer. Most cancers are epithelial in origin, and the loss of cell polarity is a critical step towards malignancy. Thus a better understanding of how polarity is established and maintained in epithelial cells will help us to understand the process of malignant transformation and may lead to improved therapies. In the present chapter we discuss the current understanding of how epithelial cell polarity is regulated and the known associations between polarity factors and cancer.

scholarly journals Susceptibility of Epithelial Cells to Pseudomonas aeruginosa Invasion and Cytotoxicity Is Upregulated by Hepatocyte Growth Factor

1998 ◽  
Vol 66 (7) ◽  
pp. 3443-3446 ◽  
Author(s):  
Suzanne M. J. Fleiszig ◽  
Vicky Vallas ◽  
Cindy H. Jun ◽  
Leo Mok ◽  
Daniel F. Balkovetz ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Growth Factor ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Hepatocyte Growth Factor ◽  
Cell Polarity ◽  
Normal Cell ◽  
Cell Clones ◽  
Susceptibility Factors ◽  
Hepatocyte Growth

ABSTRACT Normal cell polarity protects epithelial cells againstPseudomonas aeruginosa invasion and cytotoxicity. Using epithelial cell clones with selective defects in sorting of membrane constituents, and using hepatocyte growth factor pretreatment, we found that polarized susceptibility to P. aeruginosa can be altered without disrupting tight junctions. The results also showed that cellular susceptibility factors for invasion and cytotoxicity are not the same, although both are localized to the basolateral cell surface in polarized epithelial cells.

scholarly journals Gonococcal invasion into epithelial cells depends on both cell polarity and ezrin

2021 ◽  
Vol 17 (12) ◽  
pp. e1009592
Author(s):  
Qian Yu ◽  
Liang-Chun Wang ◽  
Sofia Di Benigno ◽  
Daniel C. Stein ◽  
Wenxia Song
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Polarity ◽  
Immunofluorescence Microscopy ◽  
Myosin Ii ◽  
Epithelial Cell Line ◽  
Cervical Tissue ◽  
Polarized Epithelial Cells ◽  
Cervical Epithelial Cells ◽  
Muscle Myosin

Neisseria gonorrhoeae (GC) establishes infection in women from the cervix, lined with heterogeneous epithelial cells from non-polarized stratified at the ectocervix to polarized columnar at the endocervix. We have previously shown that GC differentially colonize and transmigrate across the ecto and endocervical epithelia. However, whether and how GC invade into heterogeneous cervical epithelial cells is unknown. This study examined GC entry of epithelial cells with various properties, using human cervical tissue explant and non-polarized/polarized epithelial cell line models. While adhering to non-polarized and polarized epithelial cells at similar levels, GC invaded into non-polarized more efficiently than polarized epithelial cells. The enhanced GC invasion in non-polarized epithelial cells was associated with increased ezrin phosphorylation, F-actin and ezrin recruitment to GC adherent sites, and the elongation of GC-associated microvilli. Inhibition of ezrin phosphorylation inhibited F-actin and ezrin recruitment and microvilli elongation, leading to a reduction in GC invasion. The reduced GC invasion in polarized epithelial cells was associated with non-muscle myosin II-mediated F-actin disassembly and microvilli denudation at GC adherence sites. Surprisingly, intraepithelial GC were only detected inside epithelial cells shedding from the cervix by immunofluorescence microscopy, but not significantly in the ectocervical and the endocervical regions. We observed similar ezrin and F-actin recruitment in exfoliated cervical epithelial cells but not in those that remained in the ectocervical epithelium, as the luminal layer of ectocervical epithelial cells expressed ten-fold lower levels of ezrin than those beneath. However, GC inoculation induced F-actin reduction and myosin recruitment in the endocervix, similar to what was seen in polarized epithelial cells. Collectively, our results suggest that while GC invade non-polarized epithelial cells through ezrin-driven microvilli elongation, the apical polarization of ezrin and F-actin inhibits GC entry into polarized epithelial cells.

Epithelial cell polarity and hypoxia influence heme oxygenase-1 expression by heme in renal epithelial cells

2006 ◽  
Vol 291 (4) ◽  
pp. F790-F795 ◽  
Author(s):  
Mahesh Basireddy ◽  
Jason T. Lindsay ◽  
Anupam Agarwal ◽  
Daniel F. Balkovetz
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Surface ◽  
Cell Polarity ◽  
Heme Oxygenase ◽  
Mdck Cells ◽  
Heme Oxygenase 1 ◽  
Renal Tubules ◽  
Epithelial Cell Polarity ◽  
Surface Sensitivity

Induction of heme oxygenase-1 (HO-1) in renal tubules occurs as an adaptive and beneficial response in acute renal failure (ARF) following ischemia and nephrotoxins. Using an in vitro model of polarized Madin-Darby canine kidney (MDCK) epithelial cells, we examined apical and basolateral cell surface sensitivity to HO-1 induction by heme. Basolateral exposure to 5 μM hemin (heme chloride) resulted in higher HO-1 induction than did apical exposure. The peak induction of HO-1 by basolateral application of hemin occurred between 12 and 18 h of exposure and was dose dependent. Similar cell surface sensitivity to hemin-induced HO-1 expression was observed using a mouse cortical collecting duct cell line (94D cells). Hepatocyte growth factor (HGF) is known to decrease cell polarity of MDCK cells. Following pretreatment with HGF, apically applied hemin gave greater stimulation of HO-1 expression, whereas HGF alone did not induce HO-1. We also examined the effect of hypoxia on hemin-mediated HO-1 induction. MDCK cells were subjected to hypoxia (1% O2) for 24 h to simulate the effects of ischemic ARF. Under hypoxic conditions, both apical as well as basolateral surfaces of MDCK were more sensitive to HO-1 induction by hemin. Hypoxia alone did not induce HO-1 but appeared to potentiate both apical and basolateral sensitivity to hemin-mediated induction. These data demonstrate that the induction of HO-1 expression in polarized renal epithelia by heme is achieved primarily via basolateral exposure. However, under conditions of altered renal epithelial cell polarity and hypoxia, increased HO-1 induction occurs following apical exposure to heme.

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