The Nitric Oxide Pathway-A Potential Target for Precision Medicine in Pulmonary Arterial Hypertension

Impact of nitrate therapy on the expression of caveolin-1 and its phosphorylated isoform in lungs in the model of monocrotaline induced pulmonary hypertension

Aim: Nitric oxide signalling pathway showed to be one of the crucial factors in the treatment and pathogenesis of pulmonary arterial hypertension. The aim of this study was to determine the effect of administration of inorganic nitrate, NaNO3, on the expression of caveolin-1 and its phosphorylated isoform (pTyr14Cav-1) in lungs in the experimental model of monocrotaline induced pulmonary hypertension.

Methods: 10 weeks old male Wistar rats were subcutaneously injected with 60 mg/kg dose of monocrotaline (MCT) or vehicle (CON). Twelve days after the injection, part of the MCT group was receiving 0.3 mM NaNO3 (MCT+N0.3) daily in the drinking water and rest was receiving 0.08% NaCl solution. Four weeks after MCT administration, the rats were sacrificed in CO2. Protein expression in lungs was determined by western blot.

Results: We observed a significant decrease in the caveolin-1 expression and a significant shift towards the expression of pTyr14Cav-1 in the group treated with nitrate (p < 0.05).

Conclusion: NaNO3 administration affected the expression of caveolin-1 and the ratio of its active (phosphorylated) isoform increased.

Characteristics of circular RNA expression in lung tissues from mice with hypoxia‑induced pulmonary hypertension

Pulmonary hypertension (PH) is a life-threatening lung disease, characterized by an increase in pulmonary arterial pressure caused by vasoconstriction and vascular remodeling. The pathogenesis of PH is not fully understood, and there is a lack of potential biomarkers for the diagnosis and treatment of patients with PH. Non-coding RNAs with a characteristic covalently closed loop structure, termed circular RNAs (circRNAs), are present in a number of pulmonary diseases. To the best of our knowledge, the present study is the first to use microarray analysis to determine the expression profile of circRNAs in lung tissues from mice with hypoxia-induced PH. In total, 23 significantly upregulated and 41 significantly down-regulated circRNAs were identified. Of these, 12 differentially expressed circRNAs were selected for further validation using reverse transcription-quantitative polymerase chain reaction. Putative microRNAs (miRNAs) that bind to the dysregulated circRNAs were predicted. Subsequently, bioinformatics tools were used to construct circRNA-miRNA-mRNA networks for the two most promising circRNAs, namely mmu_circRNA_004592 and mmu_circRNA_018351. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses of target genes of the dysregulated circRNAs revealed that these dysregulated circRNAs may serve an important role in the pathogenesis of hypoxia-induced PH. Therefore, these dysregulated circRNAs are candidate diagnostic biomarkers and potential therapeutic targets for PH.