Genetic analysis among patients with dilated cardiomyopathy (DCM) is becoming an important part of clinical assessment, as it is in hypertrophic cardiomyopathy (HCM). The genetics of DCM is complex and therefore next-generation sequencing strategies are essential when providing genetic diagnostics. To achieve maximum yield, the diagnostic approach should include comprehensive clinical phenotyping combined with high-quality, high-coverage deep sequencing of DCM-associated genes and clinical variant classification as a basis for defining true yield in genetic testing. Our study has combined a novel sequencing strategy and clinical interpretation to analyse the yield and genotype–phenotype correlations among well-phenotyped Finnish DCM patients.

Occlusive vasculopathy with intimal hyperplasia and plexogenic arteriopathy are severe histopathological changes characteristic of pulmonary arterial hypertension (PAH). Although a phenotypic switch in pulmonary endothelial cells (ECs) has been suggested to play a critical role in the formation of occlusive lesions, the pathobiology of this process is poorly understood. The goal of this study was to identify novel molecular mechanisms associated with EC dysfunction and PAH-associated bone morphogenetic protein receptor 2 (BMPR2) deficiency during PAH pathogenesis. A bioinfomatics approach, patient samples, and in vitro experiments were used. By combining a metaanalysis of human idiopathic PAH (iPAH)-associated gene-expression microarrays and a unique gene expression-profiling technique in rat endothelium, our bioinformatics approach revealed a PAH-associated dysregulation of genes involving chromatin organization, DNA metabolism, and repair. Our hypothesis that altered DNA repair and loss of genomic stability play a role in PAH was supported by in vitro assays where pulmonary ECs from patients with iPAH and BMPR2-deficient ECs were highly susceptible to DNA damage. Furthermore, we showed that BMPR2 expression is tightly linked to DNA damage control because excessive DNA damage leads to rapid down-regulation of BMPR2 expression. Moreover, we identified breast cancer 1 (BRCA1) as a novel target for BMPR2 signaling and a novel modulator of pulmonary EC homeostasis. We show here that BMPR2 signaling plays a critical role in the regulation of genomic integrity in pulmonary ECs via genes such as BRCA1. We propose that iPAH-associated EC dysfunction and genomic instability are mediated through BMPR2 deficiency-associated loss of DNA damage control.

Aberrant ovarian granulosa cell proliferation and apoptosis may lead to granulosa cell tumors (GCT), the pathogenesis of which involves transcription factors GATA4, FOXL2, and SMAD3. FOXL2 gene harbors a point mutation (C134W) in a vast majority of GCTs. GATA4 is abundantly expressed in GCTs and its expression correlates with poor prognosis. The TGF-β mediator SMAD3 promotes GCT cell survival through NF-κB activation, and interacts with FOXL2. Here, we find that the expression patterns of these factors overlap in the normal human ovary and 90 GCTs, and positively correlate with each other and with their mutual target gene CCND2, which is a key factor for granulosa cell proliferation. We have explored the molecular interactions of FOXL2, GATA4, and SMAD3 and their roles in the regulation of CCND2 using co-immunoprecipitation, promoter transactivation, and cell viability assays in human GCT cells. We found that not only SMAD3, but also GATA4 physically interact with both wild type and C134W-mutated FOXL2. GATA4 and SMAD3 synergistically induce a 8-fold increase in CCND2 promoter transactivation, which is 50% reduced by both FOXL2 types. We confirmed that wild type FOXL2 significantly decreases cell viability. Interestingly, GATA4 and SMAD3 caused a marked reduction of GCT cell apoptosis induced by wild type FOXL2. Thus, the effects of GATA4 and SMAD3 on both cell viability and apoptosis are distinct from those of wild type FOXL2; a perturbation of this balance due to the oncogenic FOXL2 mutation is likely to contribute to GCT pathogenesis.