Examination of megalin in renal tubular epithelium from patients with Dent disease.
Dent disease is characteristic for the urinary loss of low-molecular-weight proteins and calcium, leading to renal calcification and, in some patients, chronic renal failure. This disorder is caused by loss-of-function mutations in the renal chloride channel gene, CLCN5. The animal model of this disease has demonstrated the possible role of disturbed megalin expression, which is a member of the low-density lipoprotein receptor family and is associated with renal reabsorption of a variety of proteins, in Dent disease. We examined the expression of megalin in the renal tubular epithelium of two unrelated patients with Dent disease. One patient, whose CLCN5 gene was completely deleted, showed significantly decreased staining of megalin compared with controls, while there was no change in another patient with partial deletion of the gene. These results demonstrated that mutation of CLCN5 in some patients with Dent disease may impair the expression of megalin, resulting in abnormal calcium metabolism, manifested as hypercalciuria and nephrocalcinosis.
Santo
Yoko
Y
Department of Developmental Medicine, D-5, Osaka University Graduate School of Medicine, Suita, 565-0871 Osaka, Japan.
Hirai
Haruhiko
H
Shima
Masaaki
M
Yamagata
Masayo
M
Michigami
Toshimi
T
Nakajima
Shigeo
S
Ozono
Keiichi
K
D002128:Calcium Metabolism Disorders / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D002675:Child, Preschool; D018118:Chloride Channels / Q000235:genetics; D004252:DNA Mutational Analysis; D004848:Epithelium / Q000378:metabolism* / Q000473:pathology; D005455:Fluorescent Antibody Technique; D040181:Genetic Diseases, X-Linked / Q000150:complications / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D007684:Kidney Tubules / Q000378:metabolism* / Q000473:pathology; D026561:Low Density Lipoprotein Receptor-Related Protein-2 / Q000096:biosynthesis*; D008297:Male; D009154:Mutation; D011507:Proteinuria / Q000209:etiology
C097503:CLC-5 chloride channel; D018118:Chloride Channels; D026561:Low Density Lipoprotein Receptor-Related Protein-2