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Over‐expression of anti‐CD75 reactive proteins on distal and collecting renal tubular epithelial cells in calcium‐oxalate stone‐forming kidneys in Egypt
Author(s) -
Kramer G.,
Steiner G.E.,
Neumayer C.,
PrinzKashani M.,
Hohenfellner M.,
Gomha M.,
Ghoneim M.,
Newman M.,
Marberger M.
Publication year - 2004
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 - 10.1111/j.1464-410x.2003.04751.x
Subject(s) - calcium oxalate , sialic acid , blot , neuraminidase , kidney , chemistry , lectin , kidney stones , pathology , microbiology and biotechnology , biology , biochemistry , medicine , urine , gene , enzyme , endocrinology
OBJECTIVE To assess the nature, distribution and expression pattern of CD75, a neuraminidase‐sensitive lymphocyte cell surface differentiation antigen, in calcium oxalate (CaOx) stone disease, as cell‐surface sialic acid might be involved CaOx crystal binding, and lectin‐binding assays suggest that sialic acid in the α2,6 position is upregulated in stone‐forming kidneys. MATERIALS AND METHODS Human CaOx stone‐forming and normal kidneys (13 each) and primary kidney epithelial cells (CAKI‐1, three samples) were analysed. The protein pattern, distribution and expression of CD75 were analysed using Western blotting, immunohistology and semi‐quantitative confocal laser scanning microscopy (cLSM). Production was investigated by α2,6‐sialyltransferase specific reverse transcription‐polymerase chain reaction. RESULTS Western blotting showed one strong band at ≈ 43 kDa that reacted with anti‐CD75 when renal epithelial and CAKI‐1 tumour cell extracts were analysed. However, in renal tissue extracts of CaOx stone formers there were additional bands at 120 and 205 kDa. Image processing after cLSM showed that anti‐CD75 reactivity was significantly greater on E‐cadherin‐positive distal and collecting tubular cells from CaOx stone‐forming kidneys, at a mean ( sd ) intensity of 87 (7), than on those from normal kidneys, at 41 (5) ( P = 0.005). CONCLUSION CD75 expression in human kidney was primarily on the luminal surface of distal tubules and collecting ducts. Whether increased epithelial CD75 expression in CaOx stone disease is a cause or result of the disease remains to be clarified.