Allelic variations of RANKL/OPG signaling system are related to bone mineral density and in vivo gene expression

作者：Takacs Istvan^*; Lazary Aron; Kosa Janos P; Kiss Janos; Balla Bernadett; Nagy Zsolt; Bacsi Krisztian; Speer Gabor; Lakatos Peter

来源：European Journal of Endocrinology, 2010, 162(2): 423-431.

DOI：10.1530/EJE-09-0617

Objective: Receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) signaling system plays a crucial role in the regulation of bone resorption. Polymorphic variations in the genes may have an influence on gene expression and bone metabolism. In the present study, we aimed to investigate the influence of RANKL/OPG allelic variations on the in vivo human gene expression of five genes, bone mineral density (BMD), and fracture incidence in Hungarian postmenopausal women.
Methods: Three hundred and sixty postmenopausal women (61.6+/-7.9 years) were genotyped. All together, five single nucleotide polymorphisms (SNPs) in the two genes have been investigated. In addition, bone samples from 17 examined subjects were acquired for gene expression studies. Bone densities and fracture data have also been collected.
Results: All two SNPs in OPG gene and three SNPs in RANKL gene showed correlation with BMD. Haplotype analysis of these genes gave similar results. The 'CCT' haplotype of RANKL promoter region, which was associated with decreased BMD, exhibited a significantly upregulated expression of RANKL mRNA, while the other haplotypes of RANKL or OPG 15 genes did not. No correlation between genetic variations and fracture data was found.
Conclusion: We have demonstrated associations between RANKL and OPG haplotypes and BMD as well as between RANKL haplotypes and in vivo RANKL expression in a Hungarian postmenopausal population. Moreover, we have found a new RANKL haplotype associating with reduced BMD and increased in vivo RANKL expression in human bone tissue.

• 出版日期2010-2