The key regulators of the cardiac and systemic response to injury are not well known, but one strategy to uncover such regulators is the identification of the genes underlying inherited forms of heart failure such as dilated cardiomyopathy (DCM). To date this approach has uncovered major roles in DCM for cytoskeletal proteins, the dystrophin-associated glycoprotein complex and for sarcomeric proteins. However mutations in these genes represent only a small proportion even of inherited DCM. Recently, distinctive forms of DCM, characterized by prominent arrhythmias and extensive fibrosis, have been mapped to unique genetic loci, and at one of these loci mutations have been discovered in an RNA binding protein RBM20. Mutations in this gene may explain 7-10% of inherited heart failure, but the mechanisms by which the RBM20 protein regulates cardiovascular function are unknown. By homology RBM20 appears to be a regulator of splicing events, and as such is likely to operate across multiple genes and in multiple tissues. Defining the mechanisms of this cardiomyopathy will require the efficient characterization of RBM20 and its regulation, identification of large numbers of genes downstream of RBM20, and systematic exploration of the effects of each of these genes on cardiac structure and function. We propose to exploit the tools of integrative genomics to rapidly define the mechanisms of RBM20-associated heart failure and relate these to existing DCM pathways in the following Specific Aims:I-Identification of the gene splicing events regulated by RBM20a) Expression profiling, using Affymetrix human splicing arrays, of RNA from the hearts and leukocytes of DCM samples from those with and without RBM 20 mutations.b) Identification of RBM20 target binding sequences using multiple complementary methodsII-Characterization of temporal and spatial nature of RBM20 splicing activity in the zebrafishIII-Identification of the RBM20 associated splicing events responsible for cardiomyopathyUsing morpholino technologies and the diverse assays for zebrafish cardiac function which we have developed, we will define the specific splicing abnormalities which lead to DCM.
|Program type||Innovative Research Grant|
|Effective start/end date||07/01/2010 → 06/30/2012|