Molecular targets of hyperphosphataemia in chronic renal failure.

Dietary phosphate restriction can prevent or retard the progress of chronic renal failure (CRF) and secondary hyperparathyroidism. The klotho gene is involved in the development of a syndrome resembling human ageing, and klotho mutant mice show abnormal calcium/vitamin D metabolism, developing hyperphosphataemia and vascular calcification. Phosphate retention rescues the phenotype of klotho mice. The level of expression of klotho RNA was greatly reduced in the kidneys of all CRF patients. Dietary P(i) restriction induced klotho expression, which enhances the beneficial effect of P(i) restriction in patients with CRF and/or on haemodialysis.