Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dent's disease is a nephrolithiasis disorder associated with hypercalciuria and low molecular weight proteinuria that is caused by mutations in the voltage-gated chloride channel ClC-5. Because the exact cause of hypercalciuria in this disease is unknown and could come from a renal, intestinal, or bone origin, we have investigated overall calcium handling in the ClC-5 knockout mouse (ClC-5 KO). On a high calcium diet, ClC-5 KO mice had elevated serum 1alpha,25-dihydroxyvitamin D3 (1alpha,25D3), alkaline phosphatase (AP), osteocalcin (OC), and urinary deoxypyridinoline (DPD), but serum parathyroid hormone (PTH), calcium, and intestinal calcium uptake was similar to that of wild-type (WT) mice. A 30-fold decrease in dietary calcium intake caused elevation of serum PTH and urinary cyclic adenosine monophosphate in ClC-5 KO mice and decreased the renal calcium excretion, which still remained 2-fold above that of WT mice. On this low calcium diet, both groups of mice had the same serum 1alpha,25D3, with similar increments in intestinal calcium absorption, serum AP, OC, and urinary DPD. These data indicate that the hypercalciuria in the ClC-5 KO mice on low and high calcium diets is of bone and renal origin and is not caused by increased intestinal calcium absorption, despite an elevated serum 1alpha,25D3. These mice data suggest that young patients with this disease may have a propensity for altered bone homeostasis that should be monitored clinically.
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PMID:The ClC-5 knockout mouse model of Dent's disease has renal hypercalciuria and increased bone turnover. 1267 22

We encountered a 16-year-old boy with Japanese Dent's disease who exhibited renal insufficiency and an osseous disorder of the spine. Proteinuria first was noted at the age of 2 years. At 13 years, the patient underwent analysis of the CLCN5 gene, which identified missense mutation (I524K) in exon 10. During follow-up, a marked increase in urinary beta2-microglobulin was associated with mild deterioration of renal function. At the age of 15 years, hypocalcemia (7.5 mg/dl) accompanied by an increased plasma concentration of alkaline phosphatase was first detected. At that time, plasma concentration of 25(OH)D3 and 1'alpha25(OH)2D3 were low accompanied by a high plasma parathyroid hormone concentration. A renal biopsy specimen revealed tubulointerstitial alterations including mononuclear cell infiltration, partial fibrosis and focal glomerular sclerosis. Immunofluorescence revealed weak, discontinuous staining of megalin along the brushborder of renal proximal tubules. Western blotting demonstrated decreased urinary excretion of megalin. Thus, clinical manifestations and prognosis may vary in Japanese Dent's disease. Reduced megalin expression may have disturbed calcium homeostasis, leading to osseous disorder in our patient.
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PMID:A boy with Japanese Dent's disease exhibiting abnormal calcium metabolism and osseous disorder of the spine: defective megalin expression at the brushborder of renal proximal tubules. 1552 62