Genetics and Genomics of SOST: Functional Analysis of Variants and Genomic Regulation in Osteoblasts

International Journal of Molecular Sciences

Núria Martínez-Gil¹  Mónica Cozar¹  Neus Roca-Ayats¹  Daniel Grinberg¹  Susanna Balcells¹  Natàlia Garcia-Giralt²  Xavier Nogués²  Diana Ovejero² 

[1] Department of Genetics, Microbiology and Statistics, Faculty of Biology, CIBERER, IBUB, IRSJD, Universitat de Barcelona, 08028 Barcelona, Spain;Musculoskeletal Research Group, Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable (CIBERFES), ISCIII, IMIM (Hospital del Mar Medical Research Institute), 08003 Barcelona, Spain;

关键词: sclerostin;    bone;    4C-seq;    luciferase reporter assay;    HBM;   

DOI  :  10.3390/ijms22020489

来源: DOAJ

【 摘 要 】

SOST encodes the sclerostin protein, which acts as a key extracellular inhibitor of the canonical Wnt pathway in bone, playing a crucial role in skeletal development and bone homeostasis. The objective of this work was to assess the functionality of two variants previously identified (the rare variant rs570754792 and the missense variant p.Val10Ile) and to investigate the physical interactors of the SOST proximal promoter region in bone cells. Through a promoter luciferase reporter assay we show that the minor allele of rs570754792, a variant located in the extended TATA box motif, displays a significant decrease in promoter activity. Likewise, through western blot studies of extracellular and intracellular sclerostin, we observe a reduced expression of the p.Val10Ile mutant protein. Finally, using a circular chromosome conformation capture assay (4C-seq) in 3 bone cell types (MSC, hFOB, Saos-2), we have detected physical interactions between the SOST proximal promoter and the ECR5 enhancer, several additional enhancers located between EVT4 and MEOX1 and a distant region containing exon 18 of DHX8. In conclusion, SOST presents functional regulatory and missense variants that affect its expression and displays physical contacts with far reaching genomic sequences, which may play a role in its regulation within bone cells.

【 授权许可】

Unknown