Pulmonary Hypertension: A Brief Guide for Clinicians

Cannabidiol Improves Antioxidant Capacity and Reduces Inflammation in the Lungs of Rats with Monocrotaline-Induced Pulmonary Hypertension

Cannabidiol (CBD) is a plant-derived compound with antioxidant and anti-inflammatory properties. Pulmonary hypertension (PH) is still an incurable disease. CBD has been suggested to ameliorate monocrotaline (MCT)-induced PH, including reduction in right ventricular systolic pressure (RVSP), a vasorelaxant effect on pulmonary arteries and a decrease in the white blood cell count. The aim of our study was to investigate the effect of chronic administration of CBD (10 mg/kg daily for 21 days) on the parameters of oxidative stress and inflammation in the lungs of rats with MCT-induced PH. In MCT-induced PH, we found a decrease in total antioxidant capacity (TAC) and glutathione level (GSH), an increase in inflammatory parameters, e.g., tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), nuclear factor kappa B (NF-κB), monocyte chemoattractant protein-1 (MCP-1), and cluster of differentiation 68 (CD68), and the overexpression of cannabinoid receptors type 1 and 2 (CB₁-Rs, CB₂-Rs). Administration of CBD increased TAC and GSH concentrations, glutathione reductase (GSR) activity, and decreased CB₁-Rs expression and levels of inflammatory mediators such as TNF-α, IL -1β, NF-κB, MCP-1 and CD68. In conclusion, CBD has antioxidant and anti-inflammatory effects in MCT-induced PH. CBD may act as an adjuvant therapy for PH, but further detailed preclinical and clinical studies are recommended to confirm our promising results.

An enhance multimodal multiobjective optimization genetic algorithm with special crowding distance for pulmonary hypertension feature selection

Multiobjective optimization assumes a one-to-one mapping between decisions and objective space, however, this is not always the case. When many variables have the same or equivalent objective value, a multimodal multiobjective issue develops in which more than one Pareto Set (PS) maps to the same Pareto Front (PF). Evolutionary computing research into multimodal multiobjective optimization issues has increased (MMOPs). This paper proposed an enhanced multimodal multiobjective genetic algorithm to crack MMOPs using a special crowding distance calculation (ESNSGA-II). This special crowding distance calculation can consider the diversity of the decision space while paying attention to the diversity of the object space. Then, a unique crossover mechanism is established by combining the simulated binary crossover (SBX) method with the capacity of Pareto solutions to generate offspring solutions. The balance between convergence and diversity in both decision space and object space can be guaranteed synchronously, and PS distribution and PF accuracy may both be enhanced. The proposed ESNSGA-II uses the CEC2020 benchmarks MMF1-MMF8 to assess its properties. Comparing the ESNSGA-II to other recently established multimodal multiobjective evolutionary techniques demonstrates that it is capable of efficiently searching numerous PSs of MMOPs. Finally, the suggested ESNSGA-II is used to address a real MMOP problem of pulmonary hypertension detection via arterial blood gas analysis. The statistical analysis reveals that the suggested ESNSGA-II algorithm outperforms other algorithms on this MMOP, and so may be considered a possible tool for pulmonary hypertension.

Diagnostic value of computed tomography-based pulmonary artery to aorta ratio measurement in chronic obstructive pulmonary disease with pulmonary hypertension: A systematic review and meta-analysis

OBJECTIVE

We conducted a meta-analysis to systematic assess the diagnostic value of computed tomography (CT)-based pulmonary artery to aorta (PA:A) ratio measurement in COPD with pulmonary hypertension (COPD-PH).

METHODS

Published studies referring to diagnostic accuracy of PA:A ratio for COPD-PH were screened out from PubMed, Embase, Web of science, China National Knowledge databases (CNKI), Wan fang databases, and VIP databases. We used bivariate random-effects model to estimate pooled sensitivity (SEN), specificity (SPE), positive and negative likelihood ratios (PLR and NLR, respectively), and diagnostic odds ratios (DOR). Summary receiver operating characteristic (SROC) curves and area under the curve (AUC) were also calculated to summarize the aggregate diagnostic performance.

RESULTS

Nine eligible studies were included and the pooled SEN was 69% (95% CI: 59 ~ 78), SPE was 85% (95% CI: 77 ~ 90), PLR was 4.5 (95% CI: 2.8 ~ 7.5), and NLR was 0.36 (95% CI: 0.26 ~ 0.51), respectively. DOR reached 13.00 (95% CI: 6.00 ~ 28.00), and value of AUC was 0.84 (95% CI: 0.81 ~ 0.87). Subgroup analysis indicated that when the value of PA:A ratio was equal or greater than one (PA/A ≥ 1), the combined SEN, SPE, AUC, and DOR was 69%, 89%, 0.90, and 19.65, respectively.

CONCLUSIONS

PA:A ratio is helpful for appraisal of COPD-PH, and PA/A ≥ 1 possessed prominent diagnostic accuracy.

Right Ventricular Shape Feature Quantification for Evaluation of Pulmonary Hypertension: Feasibility and Preliminary Associations With Clinical Outcome Submitted for Publication

This study aimed to demonstrate feasibility of statistical shape analysis techniques to identify distinguishing features of right ventricle (RV) shape as related to hemodynamic variables and outcome data in pulmonary hypertension (PH). Cardiovascular magnetic resonance images were acquired from 50 patients (33 PH, 17 non-PH). Contemporaneous right heart catheterization data were collected for all individuals. Outcome was defined by all-cause mortality and hospitalization for heart failure. RV endocardial borders were manually segmented, and three-dimensional surfaces reconstructed at end diastole and end systole. Registration and harmonic mapping were then used to create a quantitative correspondence between all RV surfaces. Proper orthogonal decomposition was performed to generate modes describing RV shape features. The first 15 modes captured over 98% of the total modal energy. Two shape modes, 8 (free wall expansion) and 13 (septal flattening), stood out as relating to PH state (mode 13: r = 0.424, p = 0.002; mode 8: r = 0.429, p = 0.002). Mode 13 was significantly correlated with outcome (r = 0.438, p = 0.001), more so than any hemodynamic variable. Shape analysis techniques can derive unique RV shape descriptors corresponding to specific, anatomically meaningful features. The modes quantify shape features that had been previously only qualitatively related to PH progression. Modes describing relevant RV features are shown to correlate with clinical measures of RV status, as well as outcomes. These new shape descriptors lay the groundwork for a noninvasive strategy for identification of failing RVs, beyond what is currently available to clinicians.

Melatonin Attenuates Dasatinib-Aggravated Hypoxic Pulmonary Hypertension via Inhibiting Pulmonary Vascular Remodeling

Dasatinib treatment is approved as first-line therapy for chronic myeloid leukemia. However, pulmonary hypertension (PH) is a highly morbid and often fatal side-effect of dasatinib, characterized by progressive pulmonary vascular remodeling. Melatonin exerts strong antioxidant capacity against the progression of cardiovascular system diseases. The present work aimed to investigate the effect of melatonin on dasatinib-aggravated hypoxic PH and explore its possible mechanisms. Dasatinib-aggravated rat experimental model of hypoxic PH was established by utilizing dasatinib under hypoxia. The results indicated that melatonin could attenuate dasatinib-aggravated pulmonary pressure and vascular remodeling in rats under hypoxia. Additionally, melatonin attenuated the activity of XO, the content of MDA, the expression of NOX4, and elevated the activity of CAT, GPx, and SOD, the expression of SOD2, which were caused by dasatinib under hypoxia. In vitro, dasatinib led to decreased LDH activity and production of NO in human pulmonary microvascular endothelial cells (HPMECs), moreover increased generation of ROS, and expression of NOX4 both in HPMECs and primary rat pulmonary arterial smooth muscle cells (PASMCs) under hypoxia. Dasatinib up-regulated the expression of cleaved caspase-3 and the ratio of apoptotic cells in HPMECs, and also elevated the percentage of S phase and the expression of Cyclin D1 in primary PASMCs under hypoxia. Melatonin ameliorated dasatinib-aggravated oxidative damage and apoptosis in HPMECs, meanwhile reduced oxidative stress level, proliferation, and repressed the stability of HIF1-α protein in PASMCs under hypoxia. In conclusion, melatonin significantly attenuates dasatinib-aggravated hypoxic PH by inhibiting pulmonary vascular remodeling in rats. The possible mechanisms involved protecting endothelial cells and inhibiting abnormal proliferation of smooth muscle cells. Our findings may suggest that melatonin has potential clinical value as a therapeutic approach to alleviate dasatinib-aggravated hypoxic PH.

Reviewing the suitability of mitochondrial transplantation as therapeutic approach for pulmonary hypertension in the era of personalised medicine

Pulmonary hypertension (PH) is a fatal disease, defined as a mean pulmonary artery pressure ≥ 25 mm Hg. It is caused, in part, by mitochondrial dysfunction. Among the various biological therapies proposed to rescue mitochondrial dysfunction, evidence going back as far as 2009, suggests that mitochondrial transplantation is an alternative. Although scant, recent PH findings and other literature supports a role for mitochondrial transplantation as a therapeutic approach in the context of PH. In experimental models of PH, it confers beneficial effects that include reduced pulmonary vasoconstriction, reduced pulmonary vascular remodelling, and improved right ventricular function. It also reduces the proliferation of pulmonary artery smooth muscle cells. However, first, we must understand that more research is needed before mitochondrial transplantation can be considered an effective therapy in the clinical setting, as many of the mechanisms or potential long-term risks are still unknown. Second, the current challenges of mitochondrial transplantation are surmountable and should not deter researchers from further investigating its effectiveness and trying to overcome these challenges in creative ways.

Signal Transduction during Metabolic and Inflammatory Reprogramming in Pulmonary Vascular Remodeling

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by (mal)adaptive remodeling of the pulmonary vasculature, which is associated with inflammation, fibrosis, thrombosis, and neovascularization. Vascular remodeling in PAH is associated with cellular metabolic and inflammatory reprogramming that induce profound endothelial and smooth muscle cell phenotypic changes. Multiple signaling pathways and regulatory loops act on metabolic and inflammatory mediators which influence cellular behavior and trigger pulmonary vascular remodeling in vivo. This review discusses the role of bioenergetic and inflammatory impairments in PAH development.

Metabolism, Mitochondrial Dysfunction, and Redox Homeostasis in Pulmonary Hypertension

Pulmonary hypertension (PH) represents a group of disorders characterized by elevated mean pulmonary artery (PA) pressure, progressive right ventricular failure, and often death. Some of the hallmarks of pulmonary hypertension include endothelial dysfunction, intimal and medial proliferation, vasoconstriction, inflammatory infiltration, and in situ thrombosis. The vascular remodeling seen in pulmonary hypertension has been previously linked to the hyperproliferation of PA smooth muscle cells. This excess proliferation of PA smooth muscle cells has recently been associated with changes in metabolism and mitochondrial biology, including changes in glycolysis, redox homeostasis, and mitochondrial quality control. In this review, we summarize the molecular mechanisms that have been reported to contribute to mitochondrial dysfunction, metabolic changes, and redox biology in PH.

Arterial partial pressure of oxygen and procalcitonin levels correlate with pulmonary artery systolic pressure in patients with active pulmonary tuberculosis

OBJECT

We aimed to study whether arterial blood gas parameters, inflammatory markers, and coagulation indicators correlate with pulmonary artery systolic pressure (PASP) values in patients with active pulmonary tuberculosis (PTB).

METHODS

A total of 121 patients with PTB who had a measurement of PASP by Doppler echocardiography in the active phase of tuberculosis were included in this study. We carried out univariate and multivariate linear regression analyses to determine factors correlated with PASP values. We excluded patients with other diseases or conditions that might lead to increased PASP.

RESULTS

Univariate linear regression analysis revealed positive correlations of age, white blood cell count, neutrophils ratio, Log procalcitonin, erythrocyte sedimentation rate, Log C-reactive protein, fibrinogen, Log D-dimer with PASP and showed an inverse correlation of arterial partial pressure of oxygen (PaO₂) and arterial oxygen saturation (SaO₂) with PASP. Multiple linear regression analysis demonstrated that PaO₂ and Log procalcitonin remained correlated with PASP values.

CONCLUSION

PaO₂ and procalcitonin were strongly correlated with PASP values in patients with active PTB. The degree of hypoxia and severity of secondary respiratory bacterial infection may influence PASP value in active PTB.

Chronic Thromboembolic Pulmonary Hypertension: An Update

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease observed in a small proportion of patients after acute pulmonary embolism (PE). CTEPH has a high morbidity and mortality rate, related to the PH severity, and a poor prognosis, which mirrors the right ventricular dysfunction involvement. Pulmonary endarterectomy (PEA) reduces pulmonary vascular resistance, making it the treatment of choice and should be offered to operable CTEPH patients, as significant symptomatic and prognostic improvement has been observed. Moreover, these patients may also benefit from the advances made in surgical techniques and pulmonary hypertension-specific medication. However, not all patients are eligible for PEA surgery, as some have either distal pulmonary vascular obstruction and/or significant comorbidities. Therefore, surgical candidates should be carefully selected by an interprofessional team in expert centers. This review aims at making an overview of the risk factors and latest developments in diagnostic tools and treatment options for CTEPH.

Disulfiram attenuates hypoxia-induced pulmonary hypertension by inhibiting GSDMD cleavage and pyroptosis in HPASMCs

BACKGROUND

Pulmonary hypertension (PH) is characterized by progressive pulmonary arterial remodelling, associated with different severities of inflammation and altered immune processes. Disulfiram eliminates the formation of N-gasdermin D (GSDMD) plasma membrane pores to prevent pyroptosis. Pyroptosis is a form of lytic cell death characterized by inflammasome activation and proinflammatory cytokine release that acts in the development of PH. We sought to investigate whether disulfiram could alleviate hypoxia-induced PH by inhibiting pyroptosis.

METHODS

To investigate whether disulfiram alleviates the progression of pulmonary hypertension, rodents were exposed to chronic hypoxia (10% oxygen, 4 weeks) to induce PH. The severity of PH was assessed by measuring right ventricular systolic pressure, mean pulmonary artery pressure, and the degree of right ventricular hypertrophy. Western blotting was used to measure proteins associated with the pyroptosis pathway, and ELISA was performed to measure the secretion of IL-18 and IL-1β, both of which are the primary methods for assessing pyroptosis.

RESULTS

IL-18 and IL-1β concentrations were higher in patients with PH than in normal controls. Disulfiram suppressed the progression of PH in mice and rats through the alleviation of pulmonary arterial remodelling. Pyroptosis-related proteins and the inflammasome were activated in rodent models of PH. Disulfiram inhibited the processing of GSDMD into N-GSDMD and attenuated the secretion of IL-1β and IL18. In vivo experiments showed that disulfiram also inhibited lytic death in HPASMCs.

CONCLUSIONS

Disulfiram treatment reduces PH progression through suppressing vascular remodelling by inhibiting GSDMD cleavage and pyroptosis. It might become a novel therapeutic option for the treatment of PH.

Novel Prognostic Predictor for Primary Pulmonary Hypertension: Focus on Blood Urea Nitrogen

Background: Primary pulmonary hypertension (PPH) is a life-threatening disease associated with increased mortality. The urea cycle pathway plays a major role in PPH severity and treatment response. Little is known about the association of the blood urea nitrogen (BUN) and PPH prognosis.

Methods: Clinical data were extracted from the Medical Information Mart for Intensive Care III (MIMIC-III) database. Adult patients (≥18 years) patients with primary pulmonary hypertension (PPH) in the database were enrolled. Spearman correlation was used to analyze the association of BUN with length of hospital and intensive care unit (ICU) stays. The chi-square test was used to analyze the association of BUN with mortality rate. Survival curves were estimated using the Kaplan-Meier method and compared by the log-rank test. Multivariable logistic regression was used to identify the BUN as an independent prognostic factor of mortality. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to analyze the sensitivity and specificity for mortality.

Results: In total, 263 patients who met the selection criteria were enrolled. BUN was significantly positively associated with length of hospital stay and ICU stay (hospital stay: ρ = 0.282, ICU stay: ρ = 0.276; all P < 0.001). Higher hospital, 90-day and 4-year mortality rates were observed in the higher BUN quartile of PPH patients (hospital: P = 0.002; 90-day: P = 0.025; 4-year: P < 0.001). The Kaplan-Meier survival curves showed that patients in higher BUN quartile tended to have lower 4-year survival (Q1:7.65%, Q2: 10.71%; Q3: 14.80%, Q4: 16.84%; P < 0.0001). Logistic regression analyses found a significant association of BUN and mortality (hospital: OR = 1.05, 95% CI = 1.02–1.08, P = 0.001; 90-day: OR = 1.02, 95% CI = 1.00–1.05, P = 0.027; 4-year: OR = 1.05, 95% CI = 1.02–1.08, P = 0.001). Results of ROC and AUC showed that the diagnostic performance of BUN for mortality was moderately good.

Conclusion: BUN was positively correlated with the length of hospital stay and ICU stay of PPH patients. Higher BUN was associated with higher hospital, 90-day and 4-year mortality and lower 4-year survival of PPH patients. These findings indicate that BUN can be a novel potential prognostic predictor for PPH.

Identification of a Novel Gene Correlated With Vascular Smooth Muscle Cells Proliferation and Migration in Chronic Thromboembolic Pulmonary Hypertension

Objective: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by thrombofibrotic obstruction of the proximal pulmonary arteries, which result in vascular remodeling of the distal pulmonary artery. While the cellular and molecular mechanisms underlying CTEPH pathogenesis remain incompletely understood, recent evidence implicates vascular remodeling. Here, we identify the molecular mechanisms that contribute to vascular remodeling in CTEPH. Methods: Microarray data (GSE130391) for patients with CTEPH and healthy controls were downloaded from the Gene Expression Omnibus (GEO) and screened for differentially expressed genes (DEGs). DEGs were functionally annotated using Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. A protein-protein interaction (PPI) network was constructed to identify hub genes. Finally, pulmonary artery samples were harvested from patients with CTEPH (n = 10) and from controls (n = 10) and primary vascular smooth muscle cells (VSMCs) were cultured. Effects of the proto-oncogene FOS on VSMC proliferation and migration were assessed using expression and knockdown studies. Results: We detected a total of 292 DEGs, including 151 upregulated and 141 downregulated genes. GO analysis revealed enrichment of DEGs in biological processes of signal transduction, response to lipopolysaccharide, signal transduction, and myeloid dendritic cell differentiation. Molecular function analysis revealed enrichment in tumor necrosis factor (TNF)-activated receptor activity, transcriptional activator activity, and protein homodimerization activity. The expression of TNF-α and its receptor (sTNFR1 and sTNFR2) were significantly higher in CTEPH group, compared with control group. KEGG pathway analysis revealed enrichment in salmonella infection, pathways in cancer, osteoclast differentiation, and cytokine-cytokine receptor interaction. Hub genes in the PPI included FOS, suggesting an important role for this gene in vascular remodeling in CTEPH. Primary VSMCs derived from patients with CTEPH showed increased FOS expression and high proliferation and migration, which was attenuated by FOS inhibition. In control VSMCs, TNF-α treatment increased proliferation and migration, which FOS inhibition likewise attenuated. Conclusion: TNF-α drives CTEPH pathogenesis by promoting VSMC proliferation and migration via increased FOS expression. These results advance our understanding of the molecular mechanisms of vascular remodeling in CTEPH, and may inform the development of new therapeutic targets.

Perioperative Management of Pulmonary Hypertension. a Review

Pulmonary hypertension is a rare and progressive pathology defined by abnormally high pulmonary artery pressure mediated by a diverse range of aetiologies. It affects up to twenty-six individuals per one million patients currently living in the United Kingdom (UK), with a median life expectancy of 2.8 years in idiopathic pulmonary hypertension. The diagnosis of pulmonary hypertension is often delayed due to the presentation of non-specific symptoms, leading to a delay in referral to specialists services. The complexity of treatment necessitates a multidisciplinary approach, underpinned by a diverse disease aetiology from managing the underlying disease process to novel specialist treatments. This has led to the formation of dedicated specialist treatment centres within centralised UK cities. The article aimed to provide a concise overview of pulmonary hypertension’s clinical perioperative management, including key definitions, epidemiology, pathophysiology, and risk stratification.

[Chronic exposure to altitude. Clinical characteristics and diagnosis]

La exposición crónica a la altitud se ha asociado a hipoxia hipobárica en quienes la experimentan. Dos entidades se han asociado a la hipoxia hipobárica: la hipertensión pulmonar de la alta altitud y el mal de montaña crónico. Se describen sus características fisiológicas y de la circulación pulmonar, así como su perfil clínico y el diagnóstico.

An Overview of miRNAs Involved in PASMC Phenotypic Switching in Pulmonary Hypertension

Pulmonary hypertension (PH) is occult, with no distinctive clinical manifestations and a poor prognosis. Pulmonary vascular remodelling is an important pathological feature in which pulmonary artery smooth muscle cells (PASMCs) phenotypic switching plays a crucial role. MicroRNAs (miRNAs) are a class of evolutionarily highly conserved single-stranded small noncoding RNAs. An increasing number of studies have shown that miRNAs play an important role in the occurrence and development of PH by regulating PASMCs phenotypic switching, which is expected to be a potential target for the prevention and treatment of PH. miRNAs such as miR-221, miR-15b, miR-96, miR-24, miR-23a, miR-9, miR-214, and miR-20a can promote PASMCs phenotypic switching, while such as miR-21, miR-132, miR-449, miR-206, miR-124, miR-30c, miR-140, and the miR-17~92 cluster can inhibit it. The article reviews the research progress on growth factor-related miRNAs and hypoxia-related miRNAs that mediate PASMCs phenotypic switching in PH.

Pulmonary artery pressure is associated with mid-term major adverse cardiovascular events and postprocedure pericardial effusion in atrial fibrillation patients undergoing left atrial appendage occlusion

Background

Patients with nonvalvular atrial fibrillation (NVAF) undergoing left atrial appendage occlusion (LAAO) are at high risk of stroke or bleeding. However, risk factors for their adverse cardiovascular events remain largely unknown. Pulmonary hypertension has been shown to be related to poor prognosis in many heart diseases. In this study, we determined whether elevated pulmonary artery systolic pressure (PASP) is associated with postprocedure adverse events and major adverse cardiovascular events (MACE) in these patients.

Methods

From June 2017 and December 2019, 530 consecutive patients with NAVF at high risk of stroke or bleeding who undergone LAAO were retrospectively enrolled in our study. The preprocecure PASP was obtained by transthoracic echocardiography using the simplified Bernoulli's equation. Patients were followed-up through clinic visits or over the phone at discharge at 1-3 months, 6 months, and annually thereafter. The median follow-up time was 12 months, and clinical data were analyzed. MACE was defined as myocardial infarction, definite heart failure, stroke, or all-cause death. The outcome of postprocedure pericardial effusion included in-hospital pericardial effusion and pericardial effusion detected after discharge.

Results

Univariate analyses indicated that patients who had MACE tended to have elevated PASP (P=0.005). After dividing the cohort according to the cut-off value of PASP, Kaplan-Meier curves indicated that patients with PASP ≥39.5 mmHg had a higher risk of MACE (P=0.007) and heart failure hospitalization (P=0.005) compared to patients whose PASP <39.5 mmHg. Cox regression analysis showed that PASP was a predominant risk factor of MACE (HR =2.337, 95% CI, 1.207-4.526, P=0.012) and heart failure hospitalization (HR =3.701, 95% CI, 1.118-12.251, P=0.032). Furthermore, the PASP cut-off added incremental discriminatory capacity to the MACE risk model of this cohort. In addition, logistic regression showed that PASP had as a significant association with postprocedure pericardial effusion (OR =1.061, P=0.032).

Conclusions

Elevated PASP was associated with postprocedure pericardial effusion and mid-term MACEs in patients with atrial fibrillation (AF) undergoing LAAO.

Cannabinoids-A New Perspective in Adjuvant Therapy for Pulmonary Hypertension

Currently, no treatment can completely cure pulmonary hypertension (PH), which can lead to right ventricular failure and, consequently, death. Therefore, searching for new therapies remains important. Increased resistance in pulmonary circulation is mainly caused by the excessive contraction and proliferation of small pulmonary arteries. Cannabinoids, a group of lipophilic compounds that all interact with cannabinoid receptors, exert a pulmonary vasodilatory effect through several different mechanisms, including mechanisms that depend on vascular endothelium and/or receptor-based mechanisms, and may also have anti-proliferative and anti-inflammatory properties. The vasodilatory effect is important in regulating pulmonary resistance, which can improve patients’ quality of life. Moreover, experimental studies on the effects of cannabidiol (plant-derived, non-psychoactive cannabinoid) in animal PH models have shown that cannabidiol reduces right ventricular systolic pressure and excessive remodelling and decreases pulmonary vascular hypertrophy and pulmonary vascular resistance. Due to the potentially beneficial effects of cannabinoids on pulmonary circulation and PH, in this work, we review whether cannabinoids can be used as an adjunctive therapy for PH. However, clinical trials are still needed to recommend the use of cannabinoids in the treatment of PH.

RNA Methylations in Cardiovascular Diseases, Molecular Structure, Biological Functions and Regulatory Roles in Cardiovascular Diseases

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality in the world. Despite considerable progress in the diagnosis, treatment and prognosis of CVDs, new diagnostic biomarkers and new therapeutic measures are urgently needed to reduce the mortality of CVDs and improve the therapeutic effect. RNA methylations regulate almost all aspects of RNA processing, such as RNA nuclear export, translation, splicing and non-coding RNA processing. In view of the importance of RNA methylations in the pathogenesis of diseases, this work reviews the molecular structures, biological functions of five kinds of RNA methylations (m6A, m5C, m1a, m6am and m7G) and their effects on CVDs, including pulmonary hypertension, hypertension, vascular calcification, cardiac hypertrophy, heart failure. In CVDs, m6A “writers” catalyze the installation of m6A on RNAs, while “erasers” remove these modifications. Finally, the “readers” of m6A further influence the mRNA splicing, nuclear export, translation and degradation. M5C, m1A, m6Am and m7G are new types of RNA methylations, their roles in CVDs need to be further explored. RNA methylations have become a new research hotspot and the roles in CVDs is gradually emerging, the review of the molecular characteristics, biological functions and effects of RNA methylation on CVDs will contribute to the elucidation of the pathological mechanisms of CVDs and the discovery of new diagnostic markers and therapeutic targets of CVDs.

Ameliorative Effects and Mechanism of Buyang Huanwu Decoction on Pulmonary Vascular Remodeling: Network and Experimental Analyses

Pulmonary hypertension (PH) is a severe and progressive cardiovascular disease. Its pathological mechanism is complex, and the common pathological feature is pulmonary vascular remodeling. The efficacy of existing therapeutic agents is limited. Traditional Chinese medicine (TCM) has its unique advantages in the prevention and treatment of complex diseases. In this study, the approaches of network pharmacology combined with biological verification are employed to explore the role of Buyang huanwu decoction (BYHWD) in the treatment of PH. The active ingredients in BYHWD were first screened based on the ADME properties of the compounds. In turn, the mean of data mining was utilized to analyze the potential targets of BYHWD for the treatment of PH. On this basis, a series of interaction networks were constructed for searching the core targets. The genes including AKT1, MMP9, NOS3/eNOS, and EGFR were found to be possible key targets in BYHWD. The results of enrichment analysis showed that the targets of BYHWD focused on smooth muscle cell proliferation, migration, and apoptosis, which are classic biological processes involved in pulmonary vascular remodeling and are closely related to the PI3K-Akt-eNOS pathway. The methods of biological experiments were adopted to verify the above results. The present study elucidated the mechanism of BYHWD in the treatment of PH and provided new ideas for the clinical use of TCM in the treatment of PH.

Pulmonary arterial hypertension (PAH) from autopsy study: T-cells, B-cells and mastocytes detection as morphological evidence of immunologically mediated pathogenesis

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by severe vascular remodelling, resulting in increased pulmonary vascular resistance with cardiac hypertrophy and heart failure. However, the diagnosis of PAH is often inaccurate. Many cases of PAH are incorrectly diagnosed or missed, and they are often associated with death. The aim of this study was to verify the morphological and histological criteria of fatal cases of PAH and evaluate the lymphocytic populations associated to lesions with reactive neo-angiogenesis.

METHODS

Pulmonary lung sections from 10 cases of sudden unexpected death (SUD) in the absence of previously diagnosed diseases and in an apparent state of well-being, with final histological post autopsy diagnosis of PAH were collected. The pathological findings were compared using ten controls from non-pathological lung from deaths from other causes. The autopsies included 4 males (40%) and 6 females (60%) with an average age of 52.1 ± 10.1 years. Sections stained with hematoxylin and eosin (H&E) were revised for a morphological diagnosis. Subsequently, serial sections were performed and stained with immunohistochemistry for anti-CD20 (B-lymphocytes), anti-CD3 (T-lymphocytes), anti-CD4 (T-helper lumphocytes), anti-CD8 (T-cytotoxic lymphocytes) and anti-CD117/C-Kit (mast cells/MCs) to detect inflammatory infiltrate and different ratios of cell-type. Statistical analysis was conducted using a paired t-test looking at 100 cells in 3 different tissue samples representative of vascular lesion and 3 different random normal lung parenchyma fields without lesion (from 10 normal control lungs), to identify specific lymphocyte subpopulations in inflammatory infiltrates.

RESULTS

There was a significant percentage increase of CD20 (p < 0.001), CD8 (p = 0.002), CD4 (p < 0.001), and CD117/C-Kit positive (C-Kit+; p < 0.001) cells mainly detected around wall vessels; while increased MCs positivity and C-Kit+ were observed especially in alveolar septa. In addition, reactive angiomatosis was observed.

CONCLUSIONS

The inflammatory infiltrate should be included for a correct diagnosis of PAH besides the vascular remodelling. The inflammatory infiltrate seems to be implicated as a main factor in the pathogenesis. This finding is important to rule out secondary pulmonary hypertension, to identify SUDs of unknown causes and to add new elements to the literature that can explain the immunologically related pathogenesis of PAH.

Characterization of Contractile Machinery of Vascular Smooth Muscles in Hypertension

Hypertension is a key risk factor for cardiovascular disease and it is a growing public health problem worldwide. The pathophysiological mechanisms of vascular smooth muscle (VSM) contraction contribute to the development of hypertension. Calcium (Ca²⁺)-dependent and -independent signaling mechanisms regulate the balance of the myosin light chain kinase and myosin light chain phosphatase to induce myosin phosphorylation, which activates VSM contraction to control blood pressure (BP). Here, we discuss the mechanism of the contractile machinery in VSM, especially RhoA/Rho kinase and PKC/CPI-17 of Ca²⁺ sensitization pathway in hypertension. The two signaling pathways affect BP in physiological and pathophysiological conditions and are highlighted in pulmonary, pregnancy, and salt-sensitive hypertension.

Effect of Immune Cell Infiltration on Occurrence of Pulmonary Hypertension in Pulmonary Fibrosis Patients Based on Gene Expression Profiles

Pulmonary hypertension (PH) is a frequent complication in patients with pulmonary fibrosis (PF), whereas the mechanism was not well-understood. This study aimed to explore the influence of immune cell infiltration on PH status based on the genomic expression profiles. Microarray data of GSE24988 were downloaded from the GEO database, including 116 lung tissue samples derived from PF patients with various PH status. Proportion of infiltrated immune cells was evaluated using CIBERSORT, a gene expression-based de-convolution algorithm. A random forest classifier was constructed and out of bag (OOB) cross-validation was carried out for PH prediction. The proportions of immune infiltration cells varied differently in PH samples except T regulatory cells (p-value = 0). Compared with non-PH samples, increased number of naive B cells and plasma cells were identified in PH samples, whereas activated dendritic cells and M2 macrophages were relatively lower (p < 0.05). In the random forest model, these four types of immune cells obtained a higher variable importance score than other cells, including mean decreased accuracy and mean decreased gini evaluation. We ran the OOB cross-validation in each sample of datasets (training set and testing set) and obtained 79 and 69% accuracy, respectively. Abnormal proportions of four types of immune cells were identified in PH samples compared with non-PH samples, suggesting their involvement in PH development. In summary, the immune cell infiltration in PF patients is associated with the PH status of patients, which deserves further investigation in the future.

SOX17 Loss-of-Function Mutation Underlying Familial Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) refers to a rare, progressive disorder that is characterized by occlusive pulmonary vascular remodeling, resulting in increased pulmonary arterial pressure, right-sided heart failure, and eventual death. Emerging evidence from genetic investigations of pediatric-onset PAH highlights the strong genetic basis underpinning PAH, and deleterious variants in multiple genes have been found to cause PAH. Nevertheless, PAH is of substantial genetic heterogeneity, and the genetic defects underlying PAH in the overwhelming majority of cases remain elusive. In this investigation, a consanguineous family suffering from PAH transmitted as an autosomal-dominant trait was identified. Through whole-exome sequencing and bioinformatic analyses as well as Sanger sequencing analyses of the PAH family, a novel heterozygous SOX17 mutation, NM_022454.4: c.379C>T; p. (Gln127*), was found to co-segregate with the disease in the family, with complete penetrance. The nonsense mutation was neither observed in 612 unrelated healthy volunteers nor retrieved in the population genetic databases encompassing the Genome Aggregation Database, the Exome Aggregation Consortium database, and the Single Nucleotide Polymorphism database. Biological analyses using a dual-luciferase reporter assay system revealed that the Gln127*-mutant SOX17 protein lost the ability to transcriptionally activate its target gene NOTCH1. Moreover, the Gln127*-mutant SOX17 protein exhibited no inhibitory effect on the function of CTNNB1-encode β-catenin, which is a key player in vascular morphogenesis. This research firstly links SOX17 loss-of-function mutation to familial PAH, which provides novel insight into the molecular pathogenesis of PAH, suggesting potential implications for genetic and prognostic risk evaluation as well as personalized prophylaxis of the family members affected with PAH.

EnRank: An Ensemble Method to Detect Pulmonary Hypertension Biomarkers Based on Feature Selection and Machine Learning Models

Pulmonary hypertension (PH) is a common disease that affects the normal functioning of the human pulmonary arteries. The peripheral blood mononuclear cells (PMBCs) served as an ideal source for a minimally invasive disease diagnosis. This study hypothesized that the transcriptional fluctuations in the PMBCs exposed to the PH arteries may stably reflect the disease. However, the dimension of a human transcriptome is much higher than the number of samples in all the existing datasets. So, an ensemble feature selection algorithm, EnRank, was proposed to integrate the ranking information of four popular feature selection algorithms, i.e., T-test (Ttest), Chi-squared test (Chi2), ridge regression (Ridge), and Least Absolute Shrinkage and Selection Operator (Lasso). Our results suggested that the EnRank-detected biomarkers provided useful information from these four feature selection algorithms and achieved very good prediction accuracy in predicting the PH patients. Many of the EnRank-detected biomarkers were also supported by the literature.

A Simplified Diagnostic and Therapeutic Approach to Pulmonary Hypertension

Pulmonary hypertension remains a common but complex disorder that physicians face in their daily practice. Pulmonary hypertension has been classified by the World Health Organization into five major categories according to etiology, pathophysiology, and hemodynamic properties. The clinical course and overall prognosis varies by etiology, therefore making the correct diagnosis is paramount to avoid delay in treatment and improve outcomes. This review aims to provide clinicians with a simplified diagnostic approach to pulmonary hypertension. We also provide a guide to risk stratification and when to refer patient to a pulmonary hypertension expert center.