Expression of Fibroblast Growth Factor 23, Vitamin D Receptor, and Sclerostin in Bone Tissue from Hypercalciuric Stone Formers

Autor(es)

Menon, Viviane Barcellos ^[1] ; Affonso Moyses, Rosa Maria ^[2] ; Gomes, Samirah Abreu ^[1] ; de Carvalho, Aluizio Barbosa ^[1] ; Jorgetti, Vanda ^[2] ; Heilberg, Ita Pfeferman ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Div Nephrol, BR-04023900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Div Nephrol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Clinical Journal of the American Society of Nephrology; v. 9, n. 7, p. 1263-1270, JUL 7 2014.
• Citações Web of Science: 6

Resumo

Background and objectives Increased bone resorption, low bone formation, and abnormal mineralization have been described in stone formers with idiopathic hypercalciuria. It has been previously shown that the receptor activator of NF-kappa B ligand mediates bone resorption in idiopathic hypercalciuria (IH). The present study aimed to determine the expression of fibroblast growth factor 23 (FGF-23), vitamin D receptor (VDR), and sclerostin in bone tissue from IH stone formers. Design, setting, participants, \& measurements Immunohistochemical analysis was performed in undecalcified bone samples previously obtained for histomorphometry from 30 transiliac bone biopsies of idiopathic hypercalciuria stone-forming patients between 1992 and 2002 and 33 healthy individuals (controls). Serum parameters were obtained from their medical records. Results Histomorphometry disclosed 21 IH patients with high and 9 IH patients with normal bone resorption. Importantly, eroded surfaces (ES/BS) from IH patients but not controls were significantly correlated with VDR immunostaining in osteoblasts (r=0.51; P=0.004), sclerostin immunostaining in osteocytes (r=0.41; P=0.02), and serum 1,25-dihydroxyvitamin D (r=0.55; P<0.01). Of note, both VDR and sclerostin immunostaining were significantly correlated with serum 1,25-dihydroxyvitamin D in IH patients (r=0.52; P=0.01 and r=0.53; P=0.02, respectively), although VDR and sclerostin expression did not differ between IH and controls. IH patients with high bone resorption exhibited a significantly stronger sclerostin immunostaining than IH patients with normal bone resorption. FGF-23 expression in osteocytes from IH patients did not differ from controls and was not correlated with any histomorphometric parameter. Conclusions These findings suggest the contribution of VDR and sclerostin, as well as 1,25-dihydroxyvitamin D, to increase bone resorption in idiopathic hypercalciuria but do not implicate FGF-23 in the bone alterations seen in these patients. (AU)

• Processo FAPESP: 08/10515-0 - Expressão dos receptores de vitamina D (VDR), paratormônio (PTHR1), sensor de cálcio (CaSR) e do fator de crescimento fibroblástico 23 (FGF-23) em tecido ósseo de pacientes litiásicos hipercalciúricos
• Beneficiário: Ita Pfeferman Heilberg
• Modalidade de apoio: Auxílio à Pesquisa - Regular