Redistribution and dysfunction of integrins in cultured renal epithelial cells exposed to oxidative stress

1993 ◽  
Vol 264 (1) ◽  
pp. F149-F157 ◽  
Author(s):  
J. Gailit ◽  
D. Colflesh ◽  
I. Rabiner ◽  
J. Simone ◽  
M. S. Goligorsky

Tubular obstruction by detached renal tubular epithelial cells is a major cause of oliguria in acute renal failure. Viable renal tubular cells can be recovered from urine of patients with acute tubular necrosis, suggesting a possible defect in cell adhesion to the basement membrane. To study this process of epithelial cell desquamation in vitro, we investigated the effect of nonlethal oxidative stress on the integrin adhesion receptors of the primate kidney epithelial cell line BS-C-1. Morphological and functional studies of cell adhesion properties included the following: interference reflection microscopy, intravital confocal microscopy and immunocytochemistry, flow cytometric analysis of integrin receptor abundance, and cell-matrix attachment assay. High levels of the integrin subunits alpha 3, alpha v, and beta 1 were detected on the cell surface by fluorescence-activated cell sorting (FACS) analysis, as well as lower levels of alpha 1, alpha 2, alpha 4, alpha 5, alpha 6, and beta 3. Exposure of BS-C-1 cells to nonlethal oxidative stress resulted in the disruption of focal contacts, disappearance of talin from the basal cell surface, and in the redistribution of integrin alpha 3-subunits from predominantly basal location to the apical cell surface. As measured in a quantitative cell attachment assay, oxidative stress decreased BS-C-1 cell adhesion to type IV collagen, laminin, fibronectin, and vitronectin. Defective adhesion was not associated with a loss of alpha 3-, alpha 4-, or alpha v-integrin subunits from the cell surface.(ABSTRACT TRUNCATED AT 250 WORDS)

2002 ◽  
Vol 361 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Silvia GINÉS ◽  
Marta MARIÑO ◽  
Josefa MALLOL ◽  
Enric I. CANELA ◽  
Chikao MORIMOTO ◽  
...  

The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. The aim of the present study was to explore whether ADA—CD26 interaction plays a role in the adhesion of lymphocyte cells to human epithelial cells. To meet this aim, different lymphocyte cell lines (Jurkat and CEM T) expressing endogenous, or overexpressing human, CD26 protein were tested in adhesion assays to monolayers of colon adenocarcinoma human epithelial cells, Caco-2, which express high levels of cell-surface ADA. Interestingly, the adhesion of Jurkat and CEM T cells to a monolayer of Caco-2 cells was greatly dependent on CD26. An increase by 50% in the cell-to-cell adhesion was found in cells containing higher levels of CD26. Incubation with an anti-CD26 antibody raised against the ADA-binding site or with exogenous ADA resulted in a significant reduction (50–70%) of T-cell adhesion to monolayers of epithelial cells. The role of ADA—CD26 interaction in the lymphocyte—epithelial cell adhesion appears to be mediated by CD26 molecules that are not interacting with endogenous ADA (ADA-free CD26), since SKW6.4 (B cells) that express more cell-surface ADA showed lower adhesion than T cells. Adhesion stimulated by CD26 and ADA is mediated by T cell lymphocyte function-associated antigen. A role for ADA—CD26 interaction in cell-to-cell adhesion was confirmed further in integrin activation assays. FACS analysis revealed a higher expression of activated integrins on T cell lines in the presence of increasing amounts of exogenous ADA. Taken together, these results suggest that the ADA—CD26 interaction on the cell surface has a role in lymphocyte—epithelial cell adhesion.


2000 ◽  
Vol 278 (6) ◽  
pp. F989-F998 ◽  
Author(s):  
Rima M. Koka ◽  
Erick Huang ◽  
John C. Lieske

Adhesion of microcrystals that nucleate in tubular fluid to the apical surface of renal tubular cells could be a critical step in the formation of kidney stones, 12% of which contain uric acid (UA) either alone or admixed with calcium oxalates or calcium phosphates. UA crystals bind rapidly to monolayer cultures of monkey kidney epithelial cells (BSC-1 line), used to model the surface of the nephron, in a concentration-dependent manner. The urinary glycoproteins osteopontin, nephrocalcin, and Tamm-Horsfall glycoprotein had no effect on binding of UA crystals to the cell surface, whereas other polyanions including specific glycosaminoglycans blocked UA crystal adhesion. Specific polycations also inhibited adhesion of UA crystals and appeared to exert their inhibitory effect by coating cells. However, removal of anionic cell surface molecules with neuraminidase, heparitinase I, or chondroitinase ABC each increased UA crystal binding, and sialic acid-binding lectins had no effect. These observations suggest that hydrogen bonding and hydrophobic interactions play a major role in adhesion of electrostatically neutral UA crystals to renal cells, unlike the interaction of calcium-containing crystals with negatively charged molecules on the apical cell surface via ionic forces. After adhesion to the plasma membrane, subsequent cellular events could contribute to UA crystal retention in the kidney and the development of UA or mixed calcium and UA calculi.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jing Yu ◽  
Song Mao ◽  
Yue Zhang ◽  
Wei Gong ◽  
Zhanjun Jia ◽  
...  

Renal fibrosis is a common pathological feature of all kinds of chronic kidney diseases (CKDs) with uncertain mechanisms. Accumulating evidence demonstrated an important role of oxidative stress in the pathogenesis of CKD. Here we hypothesized that MnTBAP (manganese (III) tetrakis (4-benzoic acid)porphyrin chloride), a cell-permeable mimic of superoxide dismutase (SOD), may protect against the fibrotic response in CKD by antagonizing oxidative stress. To verify this hypothesis, we performed experiments in tubular epithelial cells and mice with 5/6 nephrectomy (Nx). In mouse tubular epithelial cells, TGF-β1 induced a significant transition to fibrotic phenotype in line with a remarkable mitochondrial dysfunction, which was markedly improved by MnTBAP (1.14 μM) pretreatment. In remnant kidneys of 5/6 Nx mice, tubulointerstitial fibrosis occurred in parallel with mitochondrial abnormality in renal tubular cells. Administration of MnTBAP significantly attenuated the deposition of extracellular matrix as evidenced by the blocked expressions of fibronectin, collagen I, and collagen III. Masson staining also displayed an ameliorated accumulation of collagenous matrix in MnTBAP-treated mice. Moreover, MnTBAP also significantly improved the severity of proteinuria without altering CKD-related hypertension. Collectively, MnTBAP therapy served as a promising strategy in preventing renal fibrosis in CKDs possibly via antagonizing mitochondrial-derived oxidative stress and subsequent protection of mitochondrial function.


Cornea ◽  
2007 ◽  
Vol 26 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Marco Porcu ◽  
Francesco Guarna ◽  
Laura Formentini ◽  
Giuseppe Faraco ◽  
Silvia Fossati ◽  
...  

1992 ◽  
Vol 116 (4) ◽  
pp. 889-899 ◽  
Author(s):  
D A Wollner ◽  
K A Krzeminski ◽  
W J Nelson

The development of polarized epithelial cells from unpolarized precursor cells follows induction of cell-cell contacts and requires resorting of proteins into different membrane domains. We show that in MDCK cells the distributions of two membrane proteins, Dg-1 and E-cadherin, become restricted to the basal-lateral membrane domain within 8 h of cell-cell contact. During this time, however, 60-80% of newly synthesized Dg-1 and E-cadherin is delivered directly to the forming apical membrane and then rapidly removed, while the remainder is delivered to the basal-lateral membrane and has a longer residence time. Direct delivery of greater than 95% of these proteins from the Golgi complex to the basal-lateral membrane occurs greater than 48 h later. In contrast, we show that two apical proteins are efficiently delivered and restricted to the apical cell surface within 2 h after cell-cell contact. These results provide insight into mechanisms involved in the development of epithelial cell surface polarity, and the establishment of protein sorting pathways in polarized cells.


2007 ◽  
Vol 178 (2) ◽  
pp. 323-335 ◽  
Author(s):  
Lene N. Nejsum ◽  
W. James Nelson

Mechanisms involved in maintaining plasma membrane domains in fully polarized epithelial cells are known, but when and how directed protein sorting and trafficking occur to initiate cell surface polarity are not. We tested whether establishment of the basolateral membrane domain and E-cadherin–mediated epithelial cell–cell adhesion are mechanistically linked. We show that the basolateral membrane aquaporin (AQP)-3, but not the equivalent apical membrane AQP5, is delivered in post-Golgi structures directly to forming cell–cell contacts where it co-accumulates precisely with E-cadherin. Functional disruption of individual components of a putative lateral targeting patch (e.g., microtubules, the exocyst, and soluble N-ethylmaleimide–sensitive factor attachment protein receptors) did not inhibit cell–cell adhesion or colocalization of the other components with E-cadherin, but each blocked AQP3 delivery to forming cell–cell contacts. Thus, components of the lateral targeting patch localize independently of each other to cell–cell contacts but collectively function as a holocomplex to specify basolateral vesicle delivery to nascent cell–cell contacts and immediately initiate cell surface polarity.


1995 ◽  
Vol 108 (1) ◽  
pp. 369-377 ◽  
Author(s):  
K.L. Soole ◽  
M.A. Jepson ◽  
G.P. Hazlewood ◽  
H.J. Gilbert ◽  
B.H. Hirst

To evaluate whether a glycosylphosphatidylinositol (GPI) anchor can function as a protein sorting signal in polarized intestinal epithelial cells, the GPI-attachment sequence from Thy-1 was fused to bacterial endoglucanase E' (EGE') from Clostridium thermocellum and polarity of secretion of the chimeric EGE'-GPI protein was evaluated. The chimeric EGE'-GPI protein was shown to be associated with a GPI anchor by TX-114 phase-partitioning and susceptibility to phosphoinositol-specific phospholipase C. In polarized MDCK cells, EGE' was localized almost exclusively to the apical cell surface, while in polarized intestinal Caco-2 cells, although 80% of the extracellular form of the enzyme was routed through the apical membrane over a 24 hour period, EGE' was also detected at the basolateral membrane. Rates of delivery of EGE'-GPI to the two membrane domains in Caco-2 cells, as determined with a biotinylation protocol, revealed apical delivery was approximately 2.5 times that of basolateral. EGE' delivered to the basolateral cell surface was transcytosed to the apical surface. These data indicate that a GPI anchor does represent a dominant apical sorting signal in intestinal epithelial cells. However, the mis-sorting of a proportion of EGE'GPI to the basolateral surface of Caco-2 cells provides an explanation for additional sorting signals in the ectodomain of some endogenous GPI-anchored proteins.


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