Integrated Analysis of Single-Cell RNA Sequencing and Microarray Transcriptomics Reveals Promotion of Pulmonary Arterial Hypertension Progression by POSTN-Positive Smooth Muscle Cells

Abstract

Background: Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance, culminating in right ventricular failure and heightened mortality. Utilizing bioinformatics can aid in unraveling the underlying mechanisms of various diseases. Our study aimed to elucidate the novel pathogenic role of periostin (POSTN) in PAH through bioinformatics method. Methods: Gene expression microarray datasets and single-cell RNA sequencing (scRNA-seq) data were retrieved from the Gene Expression Omnibus. Differential expression analysis and identification of key hub genes were performed to identify crucial pathogenic genes in PAH. Functional enrichment and Gene Set Enrichment Analysis were employed to elucidate the pertinent biological functions of these key genes. A comprehensive array of bioinformatics techniques, including locus analysis, transcription factor regulation analysis, and cell interaction analysis, were further utilized to conduct an in-depth analysis of the scRNA-seq dataset. The analyses aimed to explore the association between POSTN, smooth muscle cells, and macrophages, unveiling the clinical correlation and potential pathogenic mechanisms of POSTN and PAH. Additionally, this association was validated in animal models. Results: POSTN expression was significantly elevated in PAH (p < 0.0001), and was closely associated with fibroblast infiltration (p < 0.0001). In the scRNA-seq dataset, POSTN expression was observed in fibroblasts and smooth muscle cells (SMCs), with POSTN as the most differentially expressed gene between the SMCs of PAH and donors. POSTN-positive (POSTN⁺) SMCs were notably enriched in the microenvironment of PAH. Activation of hypoxia-inducible factor 1-alpha in POSTN⁺ SMCs potentially facilitated PAH progression. Furthermore, cell-cell interactions between POSTN⁺ SMCs and regulator of G protein signaling-2 (RGS2⁺) macrophages may participate in forming an inflammatory microenvironment. Conclusions: Our study corroborated the correlation between POSTN and PAH through bioinformatics methods. It unveils that POSTN⁺ SMCs and RGS2⁺ macrophages form a mutually supportive and functionally significant interaction network, possibly playing a pivotal role in remodeling the extracellular matrix and promoting an inflammatory environment in PAH. These findings offer novel insights into PAH pathogenesis.