Effects of transgenic Pit-1 overexpression on calcium phosphate and bone metabolism

Autor: Patrick Ammann, Shizuko Nagao, Yutaka Oiso, Ryosuke Kaneko, Keiko Nishiwaki-Yasuda, Atsushi Suzuki, Mitsuyasu Itoh, Sahoko Sekiguchi, Masumi Hirabayashi, Joseph Caverzasio, Shogo Asano
Rok vydání: 2010
Předmět:
Male
Fibroblast growth factor 23
Endocrinology
Diabetes and Metabolism
Bone remodeling
Mice
0302 clinical medicine
Endocrinology
Bone Density
Bone cell
Skull/cytology/metabolism
Orthopedics and Sports Medicine
Bone and Bones/chemistry/*metabolism/radiography
Osteoblasts/metabolism
Alanine/metabolism
0303 health sciences
Alanine
Tibia/cytology/radiography
Chemistry
III/*biosynthesis/genetics/*physiology
Cell Differentiation
General Medicine
Hydroxyapatites/metabolism
medicine.anatomical_structure
Parathyroid Hormone
Alkaline phosphatase
Hydroxyapatites
Rats
Transgenic
Bone Density/*genetics
medicine.medical_specialty
Cell Differentiation/genetics
chemistry.chemical_element
030209 endocrinology & metabolism
Calvaria
Calcium
Bone and Bones
Phosphates
03 medical and health sciences
Calcitriol
Internal medicine
Phosphates/blood/*metabolism
medicine
Animals
Sodium-Phosphate Cotransporter Proteins
Type
Calcium/blood/*metabolism
Rats
Wistar
Fibroblast
Calcitriol/blood
030304 developmental biology
Osteoblasts
Tibia
Sodium-Phosphate Cotransporter Proteins
Type III
Skull
Fibroblast Growth Factors/blood
Alkaline Phosphatase
medicine.disease
Rats
Fibroblast Growth Factors
Radiography
Animals
Newborn
Alkaline Phosphatase/metabolism
Parathyroid Hormone/blood
ddc:618.97
Calcification
Zdroj: J Bone Miner Metab
Journal of Bone and Mineral Metabolism, Vol. 28, No 2 (2010) pp. 139-148
ISSN: 0914-8779
DOI: 10.1007/s00774-009-0121-3
Popis: The type III inorganic phosphate (Pi) transporter Pit-1 was previously found to be preferentially expressed in developing long bones. Several studies also described a regulation of its expression in cultured bone cells by osteotropic factors, suggesting a role of this transporter in bone metabolism. In the present study, we investigated the effects of the transgenic overexpression of Pit-1 in Wistar male rats on calcium phosphate and bone metabolism. A threefold increase and doubling of Pi transport activity were recorded in primary cultured osteoblastic cells derived from calvaria of two transgenic (Tg) lines compared with wild-type littermates (WT), respectively. Skeletal development was not affected by the transgene, and bone mass, analyzed by DXA, was slightly decreased in Tg compared with WT. Enhanced Pi uptake in calvaria-derived osteoblasts from Pit-1 Tg was associated with a significantly decreased expression of alkaline phosphatase activity and a normal deposition and calcification of the collagenous matrix. In 4-month-old adult Tg rats, serum Pi and renal Pi transport were increased compared with WT. The decrease of serum Ca concentration was associated with increased serum parathyroid hormone levels. Variations in serum Pi in Pit-1 Tg rats were negatively correlated with serum fibroblast growth factor-23, whereas 1,25-dihydroxyvitamin D(3) was not affected by Pit-1 overexpression. In conclusion, transgenic Pit-1 overexpression in rats affected bone and calcium phosphate metabolism. It also decreased alkaline phosphatase activity in osteoblasts without influencing bone matrix mineralization as well as skeletal development.
Databáze: OpenAIRE
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