A1511 Identification of CERB as a master transcription factor in monocrotaline–induced pulmonary arterial hypertension

Abstract

Objectives: A large number of differential expressed genes have been identified in the pathogenesis of pulmonary arterial hypertension (PAH) by microarray/transcriptome sequencing (RNA-seq), several transcription factors might be responsible for transcription of these differential expressed genes. The purpose of this study was to identify master regulator transcription factors in the pathogenesis of PAH. Methods: RNA-seq was performed on rats subjected to 1, 2, 3 and 4 weeks of monocrotaline (MCT) treatment. Differentially expressed genes were identified by a stand of |MCT vs Ctr log2Fold Change|≥1 and p≤0.05, master regulator transcription factors were enrichment by HOMER analysis and CREB target genes were identified by CREB target gene database. Phospho-CREB and CREB protein in rat lungs and isolated pulmonary arterial smooth muscle cells (PASMCs) were determined by western blot. Results: Differential expression of 280, 1342, 1649 and 3155 genes were identified by RNA-seq on week 1, 2, 3 and 4, respectively. HOMER analysis identified CREB as the most significant enrichment transcription factor in a cluster of sustained upregulated genes (Fig.1A). In addition, CRE-containing genes were selectively differential expressed on week 4 in rat induced by MCT (Fig.1B). In subsequent validation experiment, a sustained increase in phospho-CREB and CREB expression was observed in both total PAH lung homogenates and isolated rat PAH PASMCs by western blot. Conclusion: CREB was a master transcription factor in the pathogenesis of PAH induced by MCT.