For the lab’s first decade, we focused on the role of two key ATP-dependent chromatin-remodeling complexes in vascular development: SWI/SNF and NuRD. We first reported that these complexes transcriptionally and antagonistically regulate yolk sac vascular Wnt signaling at midgestation (Griffin and Curtis et al, 2011; Curtis and Griffin, 2012). Further analysis of SWI/SNF mutants at later stages of development revealed that they had defective venous specification due to misregulated expression of the venous transcription factor COUP-TFII (Davis et al, 2013) and defective capillary integrity due to misregulated expression of the serum response factor cofactors MRTFA/B (Menendez and Ong et al, 2017). These studies are important because they were among the first to reveal the contribution of chromatin-remodeling complexes to vascular development, and they established a model for how we could glean interesting genetic and molecular information from vascular phenotypes in chromatin-remodeling complex mutants. Notably, our approach has been tractable and productive because we can frequently attribute the specific phenotypes generated in our mutants to a single misregulated gene or signaling pathway. Therefore, this unbiased approach is revealing genes for which tight transcriptional regulation or timing is essential during vascular development. See below for descriptions of how additional SWI/SNF and NuRD vascular mutants have opened up new areas of research for the lab.
Central research approach. Because chromatin-remodeling complexes modulate expression of specific target genes, we exploit these complexes to identify critical genes for vascular development and maintenance. Specifically, we genetically delete the central ATPase of these complexes (which is critical for their function) in murine vascular cells. (1) We then look for a resulting vascular phenotype, which indicates critical target genes were misregulated in our mutants. (2) Finally, we use candidate or unbiased approaches to identify the misregulated gene(s) underlying the phenotype. This tractable approach combines strengths of forward and reverse genetics and has revealed novel aspects of vascular biology to us.