Surface binding and uptake of cadmium (Cd2+) by LLC-PK1 cells on permeable membrane supports

Prozialeck, Walter C.; Lamar, Peter C.

doi:10.1007/bf01973681

Cited by 34 publications

(12 citation statements)

References 30 publications

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“…To differentiate between apical and basolateral chemokine secretion, we used cell culture inserts as basement membrane imitation. This model has been previously established for renal tubular epithelial cells [17, 18, 19]. Here we show that IL-8 as well as MCP-1 secretion by TEC after stimulation with IL-1α is preferentially directed to the basolateral environment.…”

Section: Discussionmentioning

confidence: 66%

1,25-Dihydroxyvitamin D<sub>3</sub> Differentially Regulates IL-1α-Stimulated IL-8 and MCP-1 mRNA Expression and Chemokine Secretion by Human Primary Proximal Tubular Epithelial Cells

Krüger¹,

Kreft²

2001

Nephron Exp Nephrol

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Beside its role in calcium homeostasis, 1,25-D₃ modulates multiple immunological functions in cells of the immune system. In tubular epithelial cells, it increases the expression of HLA-DR and ICAM-1 molecules. Since production of chemokines, such as IL-8 and MCP-1, by tubular epithelial cells is crucial for the inflammatory response in acute transplant rejection and interstitial nephritis, we tested whether 1,25-D₃ influences the production of IL-8 and MCP-1 by primary human tubular epithelial cells (TEC). For chemokine detection we used enzyme-linked immunosorbent assays. We differentiated between chemokine secretion directed to the apical and basolateral environment by using cell culture inserts as a model for the tubular basement membrane. mRNA of IL-8 and MCP-1 after stimulation of TEC with IL-1α and/or 1,25-D₃ was isolated and compared by competitive RT-PCR. We found that basolateral production of IL-8 was higher than luminal secretion. 1,25-D₃ (10^–8M) alone and in combination with IL-1α suppressed IL-8 production after 48 h. Basolateral compared to luminal MCP-1 secretion was higher after stimulation either with IL-1α alone or combined with 1,25-D₃. After 72 h, 1,25-D₃ enhanced the IL-1α-stimulated MCP-1 secretion. Increased IL-8 mRNA expression after stimulation with IL-1α was suppressed by coincubation with 1,25-D₃, while MCP-1 mRNA synthesis was enhanced by 1,25-D₃ alone and in combination with IL-1 α . We conclude that 1,25-D₃ differently modulates the expression of CXC-chemokine IL-8 and CC-chemokine MCP-1 by human TEC. The differential effects of 1,25-D₃ on renal tubular cytokine secretion have to be considered in therapeutic dials on this hormone, e.g. in renal transplant rejection.

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Section: Discussionmentioning

confidence: 66%

1,25-Dihydroxyvitamin D<sub>3</sub> Differentially Regulates IL-1α-Stimulated IL-8 and MCP-1 mRNA Expression and Chemokine Secretion by Human Primary Proximal Tubular Epithelial Cells

Krüger¹,

Kreft²

2001

Nephron Exp Nephrol

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“…Such effects have been observed in vitro on filter-grown Caco-2 cells and found to be concentration-and time-dependent occurring at 5 lM Cd following a 4-h period of exposure (Duizer et al 1999). In LLC-PK1 cells, decrease in TEER has been found to be an early-response and more sensitive marker of Cd cytotoxicity than lactate dehydrogenase leakage or cell detachment (Prozialeck and Lamar 1993). Therefore, we tested whether Cd at the levels used in the present study may impair tight junctions, leading to Cd leakage through the paracellular pathways.…”

Section: Higher Bl Uptake Of CD In Differentiated Cells Exclusivelymentioning

confidence: 90%

Characterization of basolateral-to-apical transepithelial transport of cadmium in intestinal TC7 cell monolayers

et al. 2011

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Cadmium (Cd) is a toxic metal with an extremely long half-life in humans. The intestinal absorption of Cd has been extensively studied but the role the intestinal epithelium may play in metal excretion has never been considered. The basolateral (BL)-to-apical (AP) transepithelial transport of Cd was characterized in TC7 human intestinal cells. Both AP and BL uptakes varied with days in culture, and BL uptake was twofold higher compared to AP in differentiated cultures. A 50% increase in the BL uptake of 0.5 μM (109)Cd was observed at pH 8.5 in a chloride but not nitrate medium, suggesting the involvement of a pH-sensitive mechanism of transport for chloro-complexes. Fe and Zn inhibited the BL uptake of Cd whereas complexation by albumin had no effect, but the stimulatory effect of pH 8.5 was lost in the presence of albumin. The BL uptake of [(3)H]-MPP(+) and (109)Cd were both inhibited by decynium22 without reciprocal inhibition. MRP2 and MDR1 mRNA levels increased as a function of days in culture. A 25 and 20% decrease in the cellular AP efflux of Cd was observed in the presence of verapamil and probenecid, respectively. In cells treated with BSO, which lowered by 26% the total cellular thiol content, the inhibitory effect of verapamil increased, whereas that of probenecid decreased. These results reveal the existence of a decynium22-sensitive mechanism of transport for Cd at the BL membrane, and suggest the involvement of MDR1 and MRP2 in cellular Cd efflux at the AP membrane. It is conceivable that the intestinal epithelium may contribute to Cd blood excretion.

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“…No stimulation after exposure to differently fimbriated E. coli was seen (23). Other investigators described a polarity of renal tubular epithelium cultured on microporous cell culture inserts (26,30). Recently, Phillips et al reported that proximal tubular cells secrete transforming growth factor ␤ 1 equally into the apical and basolateral compartments only after basolateral exposure to platelet-derived growth factor in combination with D-glucose (25).…”

Section: Discussionmentioning

confidence: 99%

Interleukin-8 Secretion of Cortical Tubular Epithelial Cells Is Directed to the Basolateral Environment and Is Not Enhanced by Apical Exposure toEscherichia coli

Krüger¹,

Brandt

Klinger³

et al. 2000

Infect Immun

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More than 80% of urinary tract infections in adults are caused by Escherichia coli (31). For E. coli, different factors of virulence, e.g., lipopolysaccharides (LPS), hemolysins, or various types of fimbriae, have been characterized (8). Multiple lines of evidence have emerged concerning the involvement of proximal tubular epithelial cells (TEC) in the renal immune response. These cells have been shown to express major histocompatibility complex (MHC) class II antigens, which are essential for antigen presentation to CD4 ϩ lymphocytes (32) and cellular adhesion molecules crucial for leukocyte migration, e.g., intercellular adhesion molecule-1 (16, 18) and VCAM-1 (6). They are capable of processing and presenting foreign antigen (27) and, besides other cytokines, produce different chemokines, a group of low-molecular-weight cytokines with chemotactic functions. So far, the secretion of RANTES (14), MCP-1 (10), ENA-78 (28), and interleukin-8 (IL-8) (29) has been studied in TEC. Secretion of IL-8 is supposed to be of major relevance for the influx of neutrophils after bacterial contact. In earlier studies we showed that, in contrast to renal carcinoma cells (3), the expression of MHC class II molecules and intercellular adhesion molecule-1 by TEC could not be significantly enhanced by S fimbriae, LPS, or E. coli (21, 23). Furthermore, the secretion of IL-6, tumor necrosis factor alpha, and IL-8 by TEC grown as monolayers could be stimulated by cytokines, but not by S fimbriae, LPS, or E. coli (23). Concerning signalling of TEC directed to the basolateral environment, the in vitro model of monolayer cultures grown on a continuous surface has its limitations. Therefore, we tested whether basolaterally directed IL-8 secretion by TEC differs from luminal secretion and, if so, whether basolaterally directed IL-8 secretion can be stimulated by virulence factors of E. coli. MATERIALS AND METHODSPrimary cell culture of TEC and electron microscopy. Normal renal tissue was obtained in the local Department of Urology from nephrectomies due to tumors (23). Cells were grown from 1-mm 3 pieces of renal cortex in Dulbecco's modified Eagle medium-Ham's F-12 medium (BioWhittaker, Heidelberg, Germany) supplemented with epidermal growth factor (10 ng/ml), insulin-transferrin-sodiumselenite medium supplement (5 mg/liter), hydrocortisone (37.4 g/liter), 3,3-5-triiodo-L-thyronine (40 mg/liter), penicillin (100 U/ml), streptomycin (100 g/ ml), and 1 M HEPES buffer (15 ml/liter of medium). All supplements were obtained from Sigma, Deisenhofen, Germany, except for penicillin and streptomycin (BioWhittaker). The purity and proximal tubular origin of each cell culture were determined by immunohistochemistry by using anti-cytokeratin (Dianova, Hamburg, Germany), anti-APM (kindly provided by J. E. Scherberich, Frankfurt, Germany), anti-CD68, and anti-factor VIII antibodies (both from Dako, Hamburg, Germany) (21) and by electron microscopy. The ultrastructure of TEC with a microvillus surface is presented in Fig. 1. For electron microscopy, sma...

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Surface binding and uptake of cadmium (Cd2+) by LLC-PK1 cells on permeable membrane supports

Cited by 34 publications

References 30 publications

1,25-Dihydroxyvitamin D<sub>3</sub> Differentially Regulates IL-1α-Stimulated IL-8 and MCP-1 mRNA Expression and Chemokine Secretion by Human Primary Proximal Tubular Epithelial Cells

1,25-Dihydroxyvitamin D<sub>3</sub> Differentially Regulates IL-1α-Stimulated IL-8 and MCP-1 mRNA Expression and Chemokine Secretion by Human Primary Proximal Tubular Epithelial Cells

Characterization of basolateral-to-apical transepithelial transport of cadmium in intestinal TC7 cell monolayers

Interleukin-8 Secretion of Cortical Tubular Epithelial Cells Is Directed to the Basolateral Environment and Is Not Enhanced by Apical Exposure toEscherichia coli

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