Genomewide RNA expression profiling in lung identifies distinct signatures in idiopathic pulmonary arterial hypertension and secondary pulmonary hypertension

Abstract

Idiopathic pulmonary arterial hypertension (PAH) is a life-threatening condition characterized by pulmonary arteriolar remodeling. This investigation aimed to identify genes involved specifically in the pathogenesis of PAH and not other forms of pulmonary hypertension (PH). Using genomewide microarray analysis, we generated the largest data set to date of RNA expression profiles from lung tissue specimens from 1) 18 PAH subjects and 2) 8 subjects with PH secondary to idiopathic pulmonary fibrosis (IPF) and 3) 13 normal subjects. A molecular signature of 4,734 genes discriminated among these three cohorts. We identified significant novel biological changes that were likely to contribute to the pathogenesis of PAH, including regulation of actin-based motility, protein ubiquitination, and cAMP, transforming growth factor-␤, MAPK, estrogen receptor, nitric oxide, and PDGF signaling. Bone morphogenic protein receptor type II expression was downregulated, even in subjects without a mutation in this gene. Women with PAH had higher expression levels of estrogen receptor 1 than normal women. Real-time quantitative PCR confirmed differential expression of the following genes in PAH relative to both normal controls and PH secondary to IPF: a disintegrin-like and metalloprotease with thrombospondin type 1 motif 9, cell adhesion molecule with homology to L1CAM, cytochrome b558 and ␤-polypeptide, coagulation factor II receptor-like 3, A-myb myeloblastosis viral oncogene homolog 1, nuclear receptor coactivator 2, purinergic receptor P2Y, platelet factor 4, phospholamban, and tropomodulin 3. This study shows that PAH and PH secondary to IPF are characterized by distinct gene expression signatures, implying distinct pathophysiological mechanisms. bone morphogenic protein receptor type II; estrogen; idiopathic pulmonary fibrosis; microarrays; mitogen-activated protein kinase; nitric oxide; platelet-derived growth factor PULMONARY ARTERIAL HYPERTENSION (PAH) is a disease characterized by elevated mean pulmonary arterial pressures (Ն25 mmHg at rest or Ն30 mmHg during exercise) (56) and subsequent right ventricular hypertrophy and failure. Vascular remodeling, manifested by excessive proliferation of vascular endothelium, smooth muscle cells, and fibroblasts, resulting in thickening of the walls of the pulmonary arterioles and formation of plexiform lesions, is the underlying cause of the increased vascular resistance (65). The mean survival time without treatment is ϳ2.8 yr, and the ratio of affected women to men is up to 3:1 (38, 46). PAH is termed idiopathic when sporadic, and familial in the 6% of cases with a positive family history. Both forms appear to share the same pathophysiological processes (16).Bone morphogenic protein (BMP) receptor type II (BMPR2) mutations, including exon duplications and deletions and gene

A Novel Molecular Signature for Elevated Tricuspid Regurgitation Velocity in Sickle Cell Disease

“…For the latter comparison, a two-gene intersection was identified (vaccinia related kinase 2, proteasome subunit, a type 3). Although there are no prior published studies that have explored microarray expression profiles of PH or elevated TRV in SCD, comparison of the 631 dysregulated genes for an elevated TRV to published dysregulated genes in patients with PAH revealed greater than 50 common genes (17). Such a large overlap of genes provides further evidence of the genes that have surfaced from the current study for an elevated TRV and their potential for predicting PH in SCD (Table E4).…”

A Novel Genomic Signature with Translational Significance for Human Idiopathic Pulmonary Fibrosis

“…Recent genomic studies using surgical biopsies from patients with IPF support these findings, and have, in addition, demonstrated pathological gene expression changes in processes such as coagulation, angiogenesis, inflammation, apoptosis, and regeneration (11)(12)(13)(14)(15). These studies revealed a number of possible pathological pathways, and helped to identify candidate biomarkers that could be used for early diagnosis, prognosis, and disease progression monitoring (16)(17)(18)(19)(20).…”

Epigenetic mechanisms in pulmonary arterial hypertension: the need for global perspectives

“…The impact of epigenetic changes such as DNA methylation and histone modification has been better documented in the pathogenesis of other human diseases [33][34][35][36], while the application of genomic technologies in human PAH samples are relatively limited. To date, except for a few studies [37][38][39][40], the approaches employed to delineate the disease mechanisms in PAH have not provided a global perspective of the molecular network underlying the disease phenotype. To gain insight into the mechanisms leading to the development of PAH, a broad range of high-throughput techniques in genomics, proteomics and metabolomics can be employed to systematically dissect the disease-specific networks in isolated pulmonary vascular cells, peripheral blood mononuclear cells and pulmonary tissues collected from patients.…”