Linked Life Data

15256067

Source:http://linkedlifedata.com/resource/pubmed/id/15256067

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-7-16
pubmed:abstractText
Inorganic phosphate (Pi) is required for cellular function and skeletal mineralization. Serum Pi level is maintained within a narrow range through a complex interplay between intestinal absorption, exchange with intracellular and bone storage pools, and renal tubular reabsorption. The crucial regulated step in Pi homeostasis is the transport of Pi across the renal proximal tubule. Type II sodium-dependent phosphate (Na/Pi) cotransporter (NPT2) is the major molecule in the renal proximal tubule and is regulated by Pi, parathyroid hormone and by 1,25-dihydroxyvitamin D. Recent studies of inherited and acquired hypophosphatemia [X-linked hypophosphatemic rickets/osteomalacia (XLH), autosomal dominant hypophosphatemic rickets/osteomalacia (ADHR) and tumor-induced rickets/osteomalacia (TIO)], which exhibit similar biochemical and clinical features, have led to the identification of novel genes, PHEX and FGF23, that play a role in the regulation of Pi homeostasis. The PHEX gene, which is mutated in XLH, encodes an endopeptidase, predominantly expressed in bone and teeth, but not in kidney. FGF-23 may be a substrate of this endopeptidase and may therefore accumulate in patients with XLH. In the case of ADHR mutations in the furin cleavage site, which prevent the processing of FGF-23 into fragments, lead to the accumulation of a "stable" circulating form of the peptide which also inhibits renal Pi reabsorption. In the case of TIO, ectopic overproduction of FGF-23 overwhelms its processing and degradation by PHEX, leading to the accumulation of FGF-23 in the circulation and inhibition of renal Pi reabsorption. Mice homozygous for severely hypomorphic alleles of the Klotho gene exhibit a syndrome resembling human aging, including atherosclerosis, osteoporosis, emphysema, and infertility. The KLOTHO locus is associated with human survival, defined as postnatal life expectancy, and longevity, defined as life expectancy after 75. In considering the relationship of klotho expression to the dietary Pi level, the klotho protein seemed to be negatively controlled by dietary Pi.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1582-1838
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
191-200
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Inorganic phosphate homeostasis and the role of dietary phosphorus.
pubmed:affiliation
Department of Clinical Nutrition, Institute of Health Biosciences, University of Tokushima Graduate School, Kuramoto-cho 3-18-15, Tokushima, 770-8503, Japan. takeda@nutr.med.tokushima-u.ac.jp
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't