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Cell‐surface matrix proteins and sialic acids in cell‐crystal adhesion; the effect of crystal binding on the viability of human CAKI‐1 renal epithelial cells
Author(s) -
Kramer G.,
Steiner G.E.,
PrinzKashani M.,
Bursa B.,
Marberger M.
Publication year - 2003
Publication title -
bju international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 1464-4096
DOI - 10.1046/j.1464-410x.2003.04139.x
Subject(s) - dispase , sialic acid , viability assay , lectin , collagenase , cell adhesion , biochemistry , chemistry , cell , microbiology and biotechnology , biology , enzyme
Objective To investigate the role of sialic acids and cellular matrix proteins as crystal‐binding molecules in human calcium‐oxalate nephrolithiasis. Materials and methods The well‐defined human renal cancer cell line CAKI‐1 was used a standard cell culture system. After enzymatic digestion of various cell surface molecules, the binding of α2,6 ( Sambucus nigra , SN‐) and α2,3 ( Maackia amurensis , MA)‐specific lectins to CAKI‐1 cells was analysed. Simultaneously, the effect on adhesion and release of calcium oxalate monohydrate crystals was investigated (eight replicates). The effect of crystal adhesion on cell viability was assessed using Trypan blue exclusion (five replicates). Results Neuraminidase decreased MA‐lectin binding of CAKI‐1 cells by 39% ( P < 0.05) but elevated SN‐lectin binding by 812% ( P < 0.05). Simultaneously, crystal binding to CAKI‐1 cells was increased by 28% ( P > 0.05). Pretreatment with collagenase type I, trypsin and dispase II reduced crystal‐binding by 61–74% ( P < 0.05) with no effect on sialic acid‐specific lectin‐binding. However, only collagenase type I and dispase (ratio 4 : 1) were also able to release crystals from their receptor‐binding sites ( P < 0.05). An increase in the number of cell surface‐bound crystals correlated significantly with a decrease in cell viability ( P < 0.05). Conclusions α2,3‐linked sialic acids protect cells from crystal‐binding. Much greater SN‐lectin binding associated with only moderately increased crystal binding argues against α2,6‐linked sialic acids as a main target structure of crystals. In contrast, collagen type I, type IV and/or fibronectin seem to be potent crystal‐binding molecules on human renal epithelial cells, with collagen type I involved in a potential second step of crystal–cell interaction.