Treatment of pulmonary arterial hypertension: recent progress and a look to the future

Identification of differentially expressed ER stress-related genes and their association with pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a complex and progressive illness that has a multifaceted origin, significant fatality rates, and profound effects on health. The pathogenesis of PAH is poorly defined due to the insufficient understanding of the combined impact of endoplasmic reticulum (ER) stress and immune infiltration, both of which play vital roles in PAH development. This study aims to identify potential ER stress-related biomarkers in PAH and investigate their involvement in immune infiltration.

METHODS

The GEO database was used to download gene expression profiles. Genes associated with ER stress were obtained from the MSigDB database. Weighted gene co-expression network analysis (WGCNA), GO, KEGG, and protein-protein interaction (PPI) were utilized to conduct screening of hub genes and explore potential molecular mechanisms. Furthermore, the investigation also delved into the presence of immune cells in PAH tissues and the correlation between hub genes and the immune system. Finally, we validated the diagnostic value and expression levels of the hub genes in PAH using subject-workup characterization curves and real-time quantitative PCR.

RESULTS

In the PAH and control groups, a total of 31 genes related to ER stress were found to be differentially expressed. The enrichment analysis revealed that these genes were primarily enriched in reacting to stress in the endoplasmic reticulum, dealing with unfolded proteins, transporting proteins, and processing proteins within the endoplasmic reticulum. EIF2S1, NPLOC4, SEC61B, SYVN1, and DERL1 were identified as the top 5 hub genes in the PPI network. Immune infiltration analysis revealed that these hub genes were closely related to immune cells. The receiver operating characteristic (ROC) curves revealed that the hub genes exhibited excellent diagnostic efficacy for PAH. The levels of SEC61B, NPLOC4, and EIF2S1 expression were in agreement with the findings of bioinformatics analysis in the PAH group.

CONCLUSIONS

Potential biomarkers that could be utilized are SEC61B, NPLOC4, and EIF2S1, as identified in this study. The infiltration of immune cells was crucial to the development and advancement of PAH. This study provided new potential therapeutic targets for PAH.

4-hydroxysesamin protects rat with right ventricular failure due to pulmonary hypertension by inhibiting JNK/p38 MAPK signaling

The specific mechanism of 4-hydroxysesamin (4-HS), a modification of Sesamin, on right ventricular failure due to pulmonary hypertension (PH) is ominous. By creating a rat model of PH in vivo and a model of pulmonary artery smooth muscle cell (PASMC) hypoxia and inflammation in vitro, the current work aimed to investigate in depth the molecular mechanism of the protective effect of 4-HS. In an in vitro model of hypoxia PASMC, changes in cell proliferation and inflammatory factors were detected after treatment with 4-HS, followed by changes in the JNK/p38 MAPK signaling pathway as detected by Western blot signaling pathway. The findings demonstrated that 4-HS was able to minimize PASMC cell death, block the JNK/p38 MAPK signaling pathway, and resist the promoting effect of hypoxia on PASMC cell proliferation. Following that, we found that 4-HS could both mitigate the right ventricular damage brought on by MCT and had a protective impact on rats Monocrotaline (MCT)-induced PH in in vivo investigations. The key finding of this study is that 4-HS may protect against PH by inhibiting the JNK/p38 MAPK signaling pathway.

NGF increases Connexin-43 expression and function in pulmonary arterial smooth muscle cells to induce pulmonary artery hyperreactivity

AIMS

Pulmonary hypertension (PH) is characterised by an increase in pulmonary arterial pressure, ultimately leading to right ventricular failure and death. We have previously shown that nerve growth factor (NGF) plays a critical role in PH. Our objectives here were to determine whether NGF controls Connexin-43 (Cx43) expression and function in the pulmonary arterial smooth muscle, and whether this mechanism contributes to NGF-induced pulmonary artery hyperreactivity.

METHODS AND RESULTS

NGF activates its TrkA receptor to increase Cx43 expression, phosphorylation, and localization at the plasma membrane in human pulmonary arterial smooth muscle cells, thus leading to enhanced activity of Cx43-dependent GAP junctions as shown by Lucifer Yellow dye assay transfer and fluorescence recovery after photobleaching -FRAP- experiments. Using both in vitro pharmacological and in vivo SiRNA approaches, we demonstrate that NGF-dependent increase in Cx43 expression and activity in the rat pulmonary circulation causes pulmonary artery hyperreactivity. We also show that, in a rat model of PH induced by chronic hypoxia, in vivo blockade of NGF or of its TrkA receptor significantly reduces Cx43 increased pulmonary arterial expression induced by chronic hypoxia and displays preventive effects on pulmonary arterial pressure increase and right heart hypertrophy.

CONCLUSIONS

Modulation of Cx43 by NGF in pulmonary arterial smooth muscle cells contributes to NGF-induced alterations of pulmonary artery reactivity. Since NGF and its TrkA receptor play a role in vivo in Cx43 increased expression in PH induced by chronic hypoxia, these NGF/Cx43-dependent mechanisms may therefore play a significant role in human PH pathophysiology.

Continuous heart monitoring in patients with pulmonary hypertension smartwatches and direct transmission to their electronic health records: A trial design

BACKGROUND

Pulmonary hypertension is a progressive disease for which early treatment interventions are essential. Traditionally, patients undergo periodic clinical assessments. However, recent advances in wearable technology could improve the quality and efficiency of follow-up monitoring in patients with pulmonary hypertension.

TRIAL DESIGN

To our knowledge, this is the first study describing direct data transmission from a smartwatch to patients' electronic health records. It implements a novel update and customised program to continuously and automatically transmit data from a smartwatch to the patient's electronic healthcare records. It will evaluate continuous monitoring in patients with pulmonary hypertension and monitor their physical activity time, heart rate variability, and heart rate at rest and during physical activity via a smartwatch. It will also evaluate the data transmission method, and its data will be assessed by the treating physicians supplemental to clinical practice. Smartwatch integration promises numerous advantages: comprehensive cardiovascular monitoring and improved patient experience. Our continuous smartwatch monitoring approach offers a solution for earlier detection of clinical worsening and could be included as a combined endpoint in future clinical trials. It could improve patient empowerment, enhance precision medicine, and reduce hospitalisations. The user-friendly smartwatch is designed to minimise disruption in daily life.

CONCLUSION

The ability to transfer real-time data from wearable devices to electronic health records could help to transform the treatment of patients with pulmonary hypertension and their follow-up monitoring outside a clinical setting, enhancing the efficiency of healthcare delivery.

Sarcoidosis-Associated Pulmonary Hypertension

Sarcoidosis-associated pulmonary hypertension (SAPH) is a very severe complication of the disease, largely impacting its morbidity and being one of its strongest predictors of mortality. With the recent modifications of the hemodynamic definition of pulmonary hypertension (mean arterial pulmonary pressure >20 instead of <25 mmHg,) its prevalence is presently not precisely known, but it affects from 3 to 20% of sarcoid patients; mostly, although not exclusively, those with an advanced, fibrotic pulmonary disease. Its gold-standard diagnostic tool remains right heart catheterization (RHC). The decision to perform it relies on an expert decision after a non-invasive work-up, in which echocardiography remains the screening tool of choice. The mechanisms underlying SAPH, very often entangled, are crucial to define, as appropriate and personalized therapeutic strategies will aim at targeting the most significant ones. There are no recommendations so far as to the indications and modalities of the medical treatment of SAPH, which is based upon the opinion of a multidisciplinary team of sarcoidosis, pulmonary hypertension and sometimes lung transplant experts.

Hydroxy-Safflower Yellow A Mitigates Vascular Remodeling in Rat Pulmonary Arterial Hypertension

Purpose

The underlying causes of pulmonary arterial hypertension (PAH) often remain obscure. Addressing PAH with effective treatments presents a formidable challenge. Studies have shown that Hydroxysafflor yellow A (HSYA) has a potential role in PAH, While the mechanism underlies its protective role is still unclear. The study was conducted to investigate the potential mechanisms of the protective effects of HSYA.

Methods

Using databases such as PharmMapper and GeneCards, we identified active components of HSYA and associated PAH targets, pinpointed intersecting genes, and constructed a protein-protein interaction (PPI) network. Core targets were singled out using Cytoscape for the development of a model illustrating drug-component-target-disease interactions. Intersection targets underwent analysis for Gene Ontology (GO) functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Selected components were then modeled for target interaction using Autodock and Pymol. In vivo validation in a monocrotaline-induced PAH (MCT-PAH) animal model was utilized to substantiate the predictions made by network pharmacology.

Results

We associated HSYA with 113 targets, and PAH with 1737 targets, identifying 34 mutual targets for treatment by HSYA. HSYA predominantly affects 9 core targets. Molecular docking unveiled hydrogen bond interactions between HSYA and several PAH-related proteins such as ANXA5, EGFR, SRC, PPARG, PGR, and ESR1.

Conclusion

Utilizing network pharmacology and molecular docking approaches, we investigated potential targets and relevant human disease pathways implicating HSYA in PAH therapy, such as the chemical carcinogenesis receptor activation pathway and the cancer pathway. Our findings were corroborated by the efficacious use of HSYA in an MCT-induced rat PAH model, confirming its therapeutic potential.

Contribution of pressure and flow changes to resistance reduction after pulmonary arterial hypertension treatment: a meta-analysis of 3898 patients

Background

Pulmonary arterial hypertension (PAH)-targeted therapies exert significant haemodynamic changes; however, systematic synthesis is currently lacking.

Methods

We searched PubMed, CENTRAL and Web of Science for studies evaluating mean pulmonary artery pressure (mPAP), cardiac index/cardiac output (CI/CO) and pulmonary vascular resistance (PVR) of PAH-targeted therapies either in monotherapy or combinations as assessed by right heart catheterisation in treatment-naïve PAH patients. We performed a random-effects meta-analysis with meta-regression.

Results

We included 68 studies (90 treatment groups) with 3898 patients (age 47.4±13.2 years, 74% women). In studies with small PVR reduction (<4 WU), CI/CO increase (R2=62%) and not mPAP reduction (R2=24%) was decisive for the PVR reduction (p<0.001 and p=0.36, respectively, in the multivariable meta-regression model); however, in studies with large PVR reduction (>4 WU), both CI/CO increase (R2=72%) and mPAP reduction (R2=35%) contributed significantly to the PVR reduction (p<0.001 and p=0.01, respectively). PVR reduction as a percentage of the pre-treatment value was more pronounced in the oral+prostanoid intravenous/subcutaneous combination therapy (mean difference -50.0%, 95% CI -60.8- -39.2%), compared to oral combination therapy (-41.7%, -47.6- -35.8%), prostanoid i.v./s.c. monotherapy (-31.8%, -37.6- -25.9%) and oral monotherapy (-21.6%, -25.4- -17.8%). Changes in haemodynamic parameters were significantly associated with changes in functional capacity of patients with PAH as expressed by the 6-min walking distance.

Conclusion

Combination therapies, especially with the inclusion of parenteral prostanoids, lead to remarkable haemodynamic improvement in treatment-naïve PAH patients and may unmask the contribution of mPAP reduction to the overall PVR reduction in addition to the increase in CO.