RESUMO
The P2Y(2) receptor is a G-protein-coupled receptor with adenosine 5'-triphosphate (and UTP) as natural ligands. It is thought to be involved in bone physiology in an anti-osteogenic manner. As several non-synonymous single nucleotide polymorphisms (SNPs) have been identified within the P2Y(2) receptor gene in humans, we examined associations between genetic variations in the P2Y(2) receptor gene and bone mineral density (BMD) (i.e., osteoporosis risk), in a cohort of fracture patients. Six hundred and ninety women and 231 men aged ≥50 years, visiting an osteoporosis outpatient clinic at Maastricht University Medical Centre for standard medical follow-up after a recent fracture, were genotyped for three non-synonymous P2Y(2) receptor gene SNPs. BMD was measured at three locations (total hip, lumbar spine, and femoral neck) using dual-energy X-ray absorptiometry. Differences in BMD between different genotypes were tested using analysis of covariance. In women, BMD values at all sites were significantly different between the genotypes for the Leu46Pro polymorphism, with women homozygous for the variant allele showing the highest BMD values (0.05 > p > 0.01). The Arg312Ser and Arg334Cys polymorphisms showed no differences in BMD values between the different genotypes. This is the first report that describes the association between the Leu46Pro polymorphism of the human P2Y(2) receptor and the risk of osteoporosis.
Assuntos
Densidade Óssea/genética , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/genética , Osteoporose/epidemiologia , Osteoporose/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores Purinérgicos P2Y2/genética , Absorciometria de Fóton , Idoso , Estudos de Coortes , DNA/sangue , DNA/química , Feminino , Frequência do Gene , Variação Genética , Genótipo , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Medição de Risco , Saliva/químicaRESUMO
PURPOSE: Adipose derived mesenchymal stem cells (ADMSCs) may be osteogenic, may generate neoangiogenisis and may be progenitors for differentiated osteoblast mineralization. Titanium granules may be suitable as carriers for these cells. The aim was to demonstrate the osteogenic potential of ADMSCs and the effect of porous non-oxidized (Ti) and oxidized titanium (TiO2) granules as carriers for ADMSCs mineralization in vitro. MATERIALS AND METHODS: ADMSCs were isolated, cultivated in osteoblast medium and evaluated for alkaline phosphatase (ALP) assay, RNA isolation, and ALP staining. Osteoblast in vitro mineralization cells without granules or seeded on Ti or TiO2 granules were evaluated for Alizarin Red assay and RNA isolation for later gene expressing. RESULTS: ADMSCs express osteoblastic lineage genes, CBFA-1 and stain strongly for ALP. Mineralization was significantly higher for cells seeded on TiO2 than on Ti granules or pure cells. Expression of ALPL and RUNX2 was significantly higher for cells seeded on TiO2 granules and expression of COL1α1 for pure cells was significantly higher than for cells seeded on granules. CONCLUSION: ADMSCs have osteogenic potential. Mineralization was significantly high when cells were seeded on TiO2 granules. TiO2 granules may be used as carriers for adipose derived mesenchymal osteoblastic cells from laboratory bench to the patient.
Assuntos
Tecido Adiposo/citologia , Calcificação Fisiológica/fisiologia , Células-Tronco Mesenquimais/fisiologia , Osteoblastos/fisiologia , Osteogênese/fisiologia , Alicerces Teciduais/química , Titânio/química , Fosfatase Alcalina/análise , Animais , Antraquinonas , Materiais Biocompatíveis/química , Técnicas de Cultura de Células , Diferenciação Celular/fisiologia , Linhagem da Célula , Colágeno Tipo I/análise , Cadeia alfa 1 do Colágeno Tipo I , Corantes , Subunidade alfa 1 de Fator de Ligação ao Core/análise , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Neovascularização Fisiológica/fisiologia , PorosidadeRESUMO
Long-term stability of titanium implants are dependent on a variety of factors. Nanocoating with organic molecules is one of the methods used to improve osseointegration. Therefore, the aim of this study is to evaluate the in vitro effect of nanocoating with pectic rhamnogalacturonan-I (RG-I) on surface properties and osteoblasts response. Three different RG-Is from apple and lupin pectins were modified and coated on amino-functionalized tissue culture polystyrene plates (aminated TCPS). Surface properties were evaluated by scanning electron microscopy, contact angle measurement, atomic force microscopy, and X-ray photoelectron spectroscopy. The effects of nanocoating on proliferation, matrix formation and mineralization, and expression of genes (real-time PCR) related to osteoblast differentiation and activity were tested using human osteoblast-like SaOS-2 cells. It was shown that RG-I coatings affected the surface properties. All three RG-I induced bone matrix formation and mineralization, which was also supported by the finding that gene expression levels of alkaline phosphatase, osteocalcin, and collagen type-1 were increased in cells cultured on the RG-I coated surface, indicating a more differentiated osteoblastic phenotype. This makes RG-I coating a promising and novel candidate for nanocoatings of implants.