Enhanced osteogenic potential of iPSC-derived mesenchymal progenitor cells following genome editing of GWAS variants in the RUNX1 gene  

作　　者：Nazir M.Khan Andrea Wilderman Jarred M.Kaiser Archana Kamalakar Steven L.Goudy Justin Cotney Hicham Drissi 

机构地区：[1]Department of Orthopaedics,Emory University School of Medicine,Atlanta,GA,USA [2]Atlanta VA Medical Center,Decatur,GA,USA [3]Department of Genetics and Genome Sciences,University of Connecticut,Farmington,CT,USA [4]Department of Otolaryngology,Emory University School of Medicine,Atlanta,GA,USA

出　　处：《Bone Research》2024年第4期994-1008,共15页骨研究(英文版)

基　　金：supported by NIH-R21 Award (R21AR071536) to HD;funds from Emory University。

摘　　要：Recent genome-wide association studies (GWAS) identified 518 significant loci associated with bone mineral density (BMD),including variants at the RUNX1 locus (rs13046645, rs2834676, and rs2834694). However, their regulatory impact on RUNX1expression and bone formation remained unclear. This study utilized human induced pluripotent stem cells (iPSCs) differentiatedinto osteoblasts to investigate these variants’ regulatory roles. CRISPR/Cas9 was employed to generate mutant (Δ) iPSC lines lackingthese loci at the RUNX1 locus. Deletion lines (Δ1 and Δ2) were created in iPSCs to assess the effects of removing regions containingthese loci. Deletion lines exhibited enhanced osteogenic potential, with increased expression of osteogenic marker genes andAlizarin Red staining. Circularized chromosome conformation capture (4C-Seq) was utilized to analyze interactions between BMDassociatedloci and the RUNX1 promoter during osteogenesis. Analysis revealed altered chromatin interactions with multiple genepromoters including RUNX1 isoform, as well as SETD4, a histone methyltransferase, indicating their regulatory influence.Interestingly, both deletion lines notably stimulated the expression of the long isoform of RUNX1, with more modest effects on theshorter isoform. Consistent upregulation of SETD4 and other predicted targets within the Δ2 deletion suggested its removalremoved a regulatory hub constraining expression of multiple genes at this locus. In vivo experiments using a bone defect model inmice demonstrated increased bone regeneration with homozygous deletion of the Δ2 region. These findings indicate that BMDassociatedvariants within the RUNX1 locus regulate multiple effector genes involved in osteoblast commitment, providing valuableinsights into genetic regulation of bone density and potential therapeutic targets.

关 键 词：RUNX1 potential utilized 

分 类 号：R580[医药卫生—内分泌]