Pulmonary arterial hypertension and associated conditions

The Emerging Therapeutic Role of Prostaglandin E2 Signaling in Pulmonary Hypertension

Mild-to-moderate pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD). It is characterized by narrowing and thickening of the pulmonary arteries, resulting in increased pulmonary vascular resistance (PVR) and ultimately leading to right ventricular dysfunction. Pulmonary vascular remodeling in COPD is the main reason for the increase of pulmonary artery pressure (PAP). The pathogenesis of PH in COPD is complex and multifactorial, involving chronic inflammation, hypoxia, and oxidative stress. To date, prostacyclin and its analogues are widely used to prevent PH progression in clinical. These drugs have potent anti-proliferative, anti-inflammatory, and stimulating endothelial regeneration properties, bringing therapeutic benefits to the slowing, stabilization, and even some reversal of vascular remodeling. As another well-known and extensively researched prostaglandins, prostaglandin E2 (PGE2) and its downstream signaling have been found to play an important role in various biological processes. Emerging evidence has revealed that PGE2 and its receptors (i.e., EP1-4) are involved in the regulation of pulmonary vascular homeostasis and remodeling. This review focuses on the research progress of the PGE2 signaling pathway in PH and discusses the possibility of treating PH based on the PGE2 signaling pathway.

Screening of key biomarkers and immune infiltration in Pulmonary Arterial Hypertension via integrated bioinformatics analysis

This study aimed to screen key biomarkers and investigate immune infiltration in pulmonary arterial hypertension (PAH) based on integrated bioinformatics analysis. The Gene Expression Omnibus (GEO) database was used to download three mRNA expression profiles comprising 91 PAH lung specimens and 49 normal lung specimens. Three mRNA expression datasets were combined, and differentially expressed genes (DEGs) were obtained. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses and the protein-protein interaction (PPI) network of DEGs were performed using the STRING and DAVID databases, respectively. The diagnostic value of hub gene expression in PAH was also analyzed. Finally, the infiltration of immune cells in PAH was analyzed using the CIBERSORT algorithm. Total 182 DEGs (117 upregulated and 65 downregulated) were identified, and 15 hub genes were screened. These 15 hub genes were significantly associated with immune system functions such as myeloid leukocyte migration, neutrophil migration, cell chemotaxis, Toll-like receptor signaling pathway, and NF-κB signaling pathway. A 7-gene-based model was constructed and had a better diagnostic value in identifying PAH tissues compared with normal controls. The immune infiltration profiles of the PAH and normal control samples were significantly different. High proportions of resting NK cells, activated mast cells, monocytes, and neutrophils were found in PAH samples, while high proportions of resting T cells CD4 memory and Macrophages M1 cell were found in normal control samples. Functional enrichment of DEGs and immune infiltration analysis between PAH and normal control samples might help to understand the pathogenesis of PAH.

Histone methylation and vascular biology

The vasculature not only transports oxygenated blood, metabolites, and waste products but also serves as a conduit for hormonal communication between distant tissues. Therefore, it is important to maintain homeostasis within the vasculature. Recent studies have greatly expanded our understanding of the regulation of vasculature development and vascular-related diseases at the epigenetic level, including by protein posttranslational modifications, DNA methylation, and noncoding RNAs. Integrating epigenetic mechanisms into the pathophysiologic conceptualization of complex and multifactorial vascular-related diseases may provide promising therapeutic approaches. Several reviews have presented detailed discussions of epigenetic mechanisms not including histone methylation in vascular biology. In this review, we primarily discuss histone methylation in vascular development and maturity, and in vascular diseases.

Trimethoxystilbene Reduces Nuclear Factor Kappa B, Interleukin-6, and Tumor Necrosis Factor-α Levels in Rats with Pulmonary Artery Hypertension

Pulmonary artery hypertension is a refractory disease that severely affects cardiopulmonary function, mainly resulting in irreversible pulmonary vascular remodeling. Current surgical treatment of this disease is not very effective and drug treatment is targeted at relieving symptoms, improving the quality of life of patients, and preventing disease progression. The purpose of this present study was to reveal the regulatory effects of trimethoxystilbene on the serum levels of nuclear factor kappa B, interleukin-6, and tumor necrosis factor-α in a rat model of pulmonary artery hypertension and to explore the possible underlying mechanisms. Healthy Sprague Dawley rats were randomly assigned to experimental groups and treated with monocrotaline to establish the model, and we found a significant difference in the expression levels of nuclear factor kappa B, interleukin-6, and tumor necrosis factor-α between the experimental and control groups. These results suggest that trimethoxystilbene significantly reduced the inflammatory factor levels in pulmonary hypertensive rats, providing us with new potential strategies for elucidating the mechanisms of action of trimethoxystilbene in the treatment of pulmonary artery hypertension.

Validity and reliability of the Turkish version of the EmPHasis-10 questionnaire in patients with pulmonary hypertension

RATIONALE, AIMS, AND OBJECTIVES

The aim of the study was to evaluate the reliability and validity of the Turkish version of the EmPHasis-10 questionnaire to ensure cultural adaptation.

METHODS

This study involved translation, back translation, and cross-cultural adaptation. One hundred and one patients who were diagnosed as having pulmonary hypertension (PH) for at least 6 months were evaluated using the Turkish version of EmPHasis-10. Turkish version of the Minnesota Living with Heart Failure Questionnaire (MLHFQ) was used as gold standard to assess the validation of the Turkish version of the EmPHasis-10 questionnaire. Relationship between MLHFQ and EmPHasis-10 was analysed using Spearman correlation analysis to assess the validation. Cronbach alpha (internal consistency) and exploratory factor analyses were used to assess the questionnaire's reliability.

RESULTS

The statistical analysis showed that the EmPHasis-10 questionnaire showed a high validity with MLHFQ (r = 0.85) (P = 0.001). Reliability analysis showed that EmPHasis-10 had a high level of Cronbach alpha (α = 0.98) and internal consistency (ICC = 0.97).

CONCLUSIONS

The Turkish version of EmPHasis-10 is a quality of life questionnaire specific to PH. It has a high-level validity and reliability questionnaire that can be used by researchers and physicians.

Insights on the epigenetic mechanisms underlying pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH), characterized by localized increased arterial blood pressure in the lungs, is a slow developing long-term disease that can be fatal. PAH is characterized by inflammation, vascular tone imbalance, pathological pulmonary vascular remodeling, and right-sided heart failure. Current treatments for PAH are palliative and development of new therapies is necessary. Recent and relevant studies have demonstrated that epigenetic processes may exert key influences on the pathogenesis of PAH and may be promising therapeutic targets in the prevention and/or cure of this condition. The aim of the present mini-review is to summarize the occurrence of epigenetic-based mechanisms in the context of PAH physiopathology, focusing on the roles of DNA methylation, histone post-translational modifications and non-coding RNAs. We also discuss the potential of epigenetic-based therapies for PAH.