Abstract 13179: Modeling Smooth Muscle Vascular Disease by Direct Reprogramming of Patient-specific Dermal Fibroblasts
Cellular reprogramming of somatic cells into induced pluripotent stem (iPS) cells or directly into alternative somatic cells (transdifferentiation) holds promise for regenerative medicine. While generation of iPS cells from patients with defined genetic diseases has also revealed underlying mechanisms of disease, this approach has not yet been successful for directly reprogrammed cells. Here, we report a multigeneration family with diffuse vascular smooth muscle hyperproliferative disease in which we developed and utilized direct reprogramming technology to model disease. DNA sequencing of family members revealed a heterozygous frame-shift mutation in ELASTIN (ELN) (G429X), a known human disease gene, which segregated with affected individuals. Introduction of the smooth muscle-enriched factors, Myocardin and miR-145, along with with TGF-β, was sufficient to generate induced smooth muscle-like cells (iSMCs) from patient-specific dermal fibroblasts. iSMC gene expression and functional characteristics were similar to human aortic SMCs. iSMCs derived from 4 ELN+/+ and 4 ELN+/- family members revealed decreased ELN protein levels that correlated with increased iSMC proliferation in ELN+/- individuals. Mitogen-activating protein kinase/ extracellular signal-regulated kinase (MAPK/ERK) signaling was constitutively active in ELN+/¬- iSMCs, and chemical inhibition of ERK1/2 partially rescued the hyperproliferative iSMC phenotype. Furthermore, KDM5D, a histone demethylase, was downregulated in all ELN+/- iSMCs. KDM5D physically interacted with MYOCD to promote MYOCD’s pro-differentiation/anti-proliferation effects on SMCs, suggesting an additional mechanism by which ELN heterozygosity results in disease. These findings reveal a method to generate human iSMCs and illustrate the utility of direct reprogramming for modeling human disease.
- © 2013 by American Heart Association, Inc.