Next Generation Sequencing of Wild Type and CMG2-/- Rat Lung Transcriptomes

Purpose:Pulmonary arterial hypertension secondary to congenital heart disease (CHD-PAH) with systemic-to-pulmonary shunt is characterized by proliferative vascular remodeling. Capillary morphogenesis gene-2 (CMG2) exhibits roles in cell proliferation and apoptosis. The purpose of this study was to determine the possible roles of CMG2 in the pathogenesis of systemic-to-pulmonary shunt induced PAH. Methods Lung tissue sections from CHD-PAH patients, systemic-to-pulmonary shunt induced PAH rat model, CMG2-/- rats, and PASMCs were used. Immunohistochemistry, real time polymerase chain reaction, Western blot, proliferation, apoptosis, and next generation sequencing (NGS) were performed in this study. Results CMG2 expression was reduced in lung tissues and pulmonary arterioles from Eisenmenger's syndrome patient and rats with systemic-to-pulmonary shunt induced PAH. CMG2-/- rats exhibited heavier PAH and pulmonary vascular remodeling following exposure to systemic-to-pulmonary shunt for 8 weeks. Over-expression of CMG2 in cultured human PASMCs inhibited cell proliferation and promoted apoptosis, while knockdown of CMG2 promoted cell proliferation and inhibited apoptosis. A total of 1319 genes were found to be dysregulated in CMG2-/- rat lungs as detected by NGS. Biological processes influenced by these differentially expressed genes include regulation of blood vessel diameter, vasoconstriction, regulation of blood vessel size, vascular process in circulatory system, etc., and the most prominent pathway regulated is PI3K-Akt signaling pathway. Conclusion Our work identifies a novel role for CMG2 in systemic-to-pulmonary shunt induced PAH based on the findings that CMG2 deficiency could exacerbate systemic-to- pulmonary shunt induced vascular remodeling in the development of PAH. CMG2 may be a potential target for CHD-PAH treatment. Overall design: Lung mRNA profiles of 8-week old wild type (WT) and CMG2-/- rats were generated by deep sequencing, in sextuplicate, using Illuminna Novaseq.