Pulmonary arterial hypertension (PAH) is a serious disease characterized by elevated pulmonary artery pressure, inflammatory cell infiltration and pulmonary vascular remodeling. However, little is known about the pathogenic mechanisms underlying the disease onset and progression. RNA sequencing (RNA-seq) was used to identify the transcriptional profiling in control and rats injected with monocrotaline (MCT) for 1, 2, 3 and 4 weeks. A total of 23200 transcripts and 280, 1342, 908 and 3155 differentially expressed genes (DEGs) were identified at the end of week 1, 2, 3 and 4, of which Svop was the common top 10 DEGs over the course of PAH progression. Functional enrichment analysis of DEGs showed inflammatory/immune response occurred in the early stage of PAH development. KEGG pathway enrichment analysis of DEGs showed that cytokine-cytokine receptor interaction and neuroactive ligand-receptor interaction were in the initiation and progression of PAH. Further analysis revealed impaired expression of cholinergic receptors, adrenergic receptors including alpha1, beta1 and beta2 receptor, and dysregulated expression of γ-aminobutyric acid receptors. In summary, the dysregulated inflammation/immunity and neuroactive ligand receptor signaling pathways may be involved in the onset and progression of PAH.

Metal responsive transcription factor 1 (MTF-1) is a zinc-dependent transcription factor involved in the development of pulmonary arterial hypertension (PAH), which is a life-threatening disease characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling. However, little is known about the role and regulatory signaling of MTF-1 in PAH. This study aimed to investigate the effect and mechanism of MTF-1 on the proliferation of pulmonary arterial smooth muscle cells (PASMCs). Several techniques including intracellular-free zinc detected by fluorescent indicator-fluozinc-3-AM, western blot, luciferase reporter, and cell proliferation assay were conducted to perform a comprehensive analysis of MTF-1 in proliferation of PASMCs in PAH. Increased cytosolic zinc was shown in monocrotaline (MCT)-PASMCs and ZnSO₄-treated PASMCs, which led to overexpression and overactivation of MTF-1, followed by the up-regulation of placental growth factor (PlGF). Elevated MTF-1 and PlGF were observed in western blot, and high transcriptional activity of MTF-1 was confirmed by luciferase reporter in ZnSO₄-treated cells. Further investigation of cell proliferation revealed a favorable impact of zinc ions on PASMCs proliferation, with the deletion of Mtf-1/Plgf attenuating ZnSO₄-induced proliferation. Flow cytometry analysis showed that blockade of PKC signaling inhibited the cell cycle of MCT-PASMCs and ZnSO4-treated PASMCs. The Zinc/PKC/MTF-1/PlGF pathway is involved in the up-regulatory effect on the PASMCs proliferation in the process of PAH. This study provided novel insight into zinc homeostasis in the pathogenesis of PAHs, and the regulation of MTF-1 might be a potential target for therapeutic intervention in PAH.

Recent studies have demonstrated the benefits of osteocalcin (OCN) on glucose homeostasis and metabolic dysregulation. However, its role in body composition and vascular function remains unknown. This study was designed to examine changes in metabolic parameters and body composition as well as arterial stiffness after OCN treatment in type 2 diabetic rats. Adult male Sprague Dawley (SD) rats were fed chow or high fat diet (HFD) for 8 weeks, and then diabetes was induced with an injection of low-dose streptozotocin (STZ) and treated daily with intraperitoneal injections of OCN for 12 weeks. Our data showed that OCN treatment improved glucose homeostasis and lipid metabolism. Further analysis revealed that OCN treatment resulted in increased insulin sensitivity. In addition, untreated diabetic rats experienced significant weight loss, whereas OCN-treated rats better maintained body weight (300.75±38.14 g vs. 335.50±23.70, p=0.005). OCN also changed body composition, as evidenced by reduced body fat mass, specifically abdominal fat mass. OCN-treated diabetic rats also demonstrated decreased pulse-wave velocity, indicating of improved arterial stiffness. Taken together, our findings in the current study revealed that OCN therapy prevents arteriosclerosis in an induced diabetic rat model by exerting beneficial effects on glucose levels, insulin sensitivity, lipid metabolites, and body composition changes.

Circular RNAs (circRNAs) are generated by head-to-tail splicing and are ubiquitously expressed in all multicellular organisms. Their important biological functions are increasingly recognized. Cerebral ischemia reperfusion injury-induced brain microvascular endothelial cell dysfunction is an initial stage of blood-brain barrier disruption. The expression profile and potential function of circRNAs in brain microvascular endothelial cells is unknown. Rat brain microvascular endothelial cells were extracted and cultured in glucose-free medium for 4 hours with 5% CO₂ and 95% N₂, and the medium was then replaced with complete growth medium for 6 hours. The RNA in these cells was then extracted. The circRNA was identified by Find_circ and CIRI2 software. Functional and pathway enrichment analysis of genes that were common to differentially expressed mRNAs and circRNA host genes was performed by the Database for Annotation, Visualization and Integrated Discovery Functional Annotation Tool. Miranda software was used to predict microRNAs that were potentially spong-ed by circRNAs. Furthermore, cytoscape depicted the circR-NA-microRNA interaction network. The results showed that there were 1288 circRNAs in normal and oxygen-glucose deprived/recovered primary brain microvascular endothelial cells. There are 211 upregulated and 326 downregulated differentially expressed circRNAs. The host genes of these differentially expressed circRNAs overlapped with those of differentially expressed mRNAs. The shared genes were further studied by functional enrichment analyses, which revealed that circRNAs may contribute to calcium ion function and the cyclic guanosine 3′,5′-monophosphate (CAMP) dependent protein kinase (PKα) signaling pathway. Next, quantitative reverse transcription polymerase chain reaction assays were performed to detect circRNA levels transcribed from the overlapping host genes. Eight out of the ten circRNAs with the highest fold-change identified by sequencing were successfully verified. Subsequently, the circRNA-microRNA interaction networks of these eight circRNAs were explored by bioinformatic analysis. These results demonstrate that altered circRNAs may be important in the pathogenesis of cerebral ischemia reperfusion injury and consequently may also be potential therapeutic targets for cerebral ischemia diseases. All animal experiments were approved by the Chongqing Medical University Committee on Animal Research, China (approval No. CQMU20180086) on March 22, 2018.

Background: Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure, with complex etiology, difficult treatment and poor prognosis. The objective of this study was to investigate the potential biomarkers for PAH based on bioinformatics analysis. Methods: The GSE117261 datasets were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified by screening PAH patients and controls. Then the DEGs were analyzed using a Weighted Gene Co-expression Network Analysis (WGCNA) and the key modules were determined, and to further explore their potential biological functions via Gene Ontology analysis (GO), Kyoto Encyclopedia of Genes and Genomes Pathway analysis (KEGG), and Gene Set Enrichment Analysis (GSEA). Moreover, Protein–protein interaction (PPI) networks were constructed to identify hub gene candidates in the key modules. Finally, real-time quantitative polymerase chain reaction was supplied to detect the expressions of hub genes in human pulmonary arterial smooth cells treated with cobalt chloride (COCl₂) which was used to mimic hypoxia. Results: There were 2299 DEGs identified. WGCNA indicated that yellow module was the key one correlated with PAH. GO and KEGG analysis demonstrated that genes in the yellow module were mainly enriched in ‘Pathways in cancer’. GSEA revealed that ‘HALLMARK_MYC_TARGETS_V1’ was remarkably enriched in PAH. Based on the PPI network, vascular endothelial growth factor A, proto-oncogene receptor tyrosine kinase (KIT), PNN interacting serine and arginine rich protein (PNISR) and heterogeneous nuclear ribonucleoprotein H1 (HNRNPH1) were identified as the hub genes. Additionally, the PCR indicated that the elevated expressions of PNISR and HNRNPH1 were in line with the bioinformatics analysis. ROC analysis determined that PNISR and HNRNPH1 may be potential biomarkers to provide better diagnosis of PAH. Conclusion: PNISR and HNRNPH1 were potential biomarkers to diagnosis PAH. In summary, the identified DEGs, modules, pathways, and hub genes provide clues and shed light on the potential molecular mechanisms of PAH.

Pulmonary hypertension (PH) is characterized by pulmonary vascular remodeling and excessive proliferation of pulmonary artery smooth muscle cells (PASMCs). Glycolysis plays a crucial role in PH pathogenesis, but the epigenetic mechanisms linking glycolysis to PASMCs proliferation remain unclear. Histone lactylation, a novel post-translational modification derived from glycolytic lactate, may regulate PASMCs proliferation. Primary rat PASMCs were cultured under hypoxia and treated with sodium L-lactate (NaLa) to assess glycolytic activity and histone lactylation. RNA sequencing, RT-qPCR, and Western blotting identified differentially expressed genes (DEGs), while ChIP-qPCR evaluated histone lactylation enrichment at gene promoters. In vivo, a hypoxia-induced PH rat model was used to examine the effect of glycolysis inhibition using oxamate. Mendelian randomization (MR) analysis assessed the causal relationship between placental growth factor (PGF) and PH. Hypoxia and NaLa treatment significantly increased glycolytic activity, lactate production, and histone lactylation, promoting PASMCs proliferation. Transcriptomic analysis identified 157 DEGs, with five key genes (Gbe1, Pgf, Mt2A, Ythdf2 and Gys1) upregulated in response to histone lactylation. ChIP-qPCR confirmed H3K18la enrichment at their promoters. Glycolysis inhibition with oxamate effectively reduced histone lactylation, PASMCs proliferation, and vascular remodeling in hypoxic PH rats. MR analysis identified PGF as a causal factor contributing to PH risk, suggesting a potential therapeutic target. This study reveals that glycolysis-induced histone lactylation drives PASMCs proliferation and vascular remodeling in PH. Targeting lactate metabolism and histone lactylation may provide a novel therapeutic approach.