Pulmonary Hypertension: A Contemporary Review

Cinnamaldehyde alleviates pulmonary hypertension by affecting vascular remodeling through the TLR4/NF-kB/HIF-1a pathway

OBJECTIVE

To investigate the mechanism by which cinnamaldehyde (CA) alleviates pulmonary arterial hypertension (PAH) through the TLR4/NF-kB/HIF-1a pathway.

METHODS

PAH was induced in rats via SU5416 injection and hypoxia. Hemodynamics (RVMP, RVSP, mPAP) were measured. Histological changes were assessed by HE staining, and protein expressions of α-SMA, Col I, TLR4, p-p65, p65, and HIF-1a were detected by western blot. In vitro, hypoxia-induced HPAECs were treated with CA and TLR4 activator RS09TFA. Cell function was assessed by CCK-8, colony formation, and scratch assays, with VE-Cadherin and α-SMA expression analyzed by western blot.

RESULTS

PAH rats showed increased RVMP, RVSP, mPAP, and pulmonary artery thickening. CA significantly alleviated lung damage and reduced α-SMA and Col I expression. TLR4/NF-kB/HIF-1a activation with RS09TFA inhibited CA's effects. In vitro, CA mitigated hypoxia-induced HPAEC dysfunction, restoring VE-Cadherin and α-SMA expression, while RS09TFA blocked these effects.

CONCLUSION

CA alleviates PAH by inhibiting the TLR4/NF-kB/HIF-1a pathway and suppressing vascular remodeling, suggesting its potential as a therapeutic agent for PAH.

Targeting BMPER as a therapeutic strategy for pulmonary arterial hypertension

Pulmonary arterial hypertension is a life-threatening condition marked by pulmonary vascular remodeling, leading to increased pulmonary artery pressure and right heart hypertrophy. This chronic process involves excessive proliferation and migration of endothelial and smooth muscle cells. Our research, involving both pulmonary arterial hypertension patients and animal models, reveals reduced BMPER levels in cases of pulmonary arterial hypertension. In vitro mechanistic studies are performed using human pulmonary artery endothelial cells and smooth muscle cells. Additionally, we demonstrate BMPER function in vivo through its overexpression via an adeno-associated virus. Our findings indicate that BMPER can attenuate cell proliferation and migration in endothelial cells by inhibiting the PI3K/AKT signaling pathway. Additionally, BMPER reduces smooth muscle cell proliferation and migration by inhibiting BMP4 activity through a paracrine mechanism. Furthermore, BMPER expression is regulated by the transcription factor ERG. Notably, in vivo overexpression of BMPER significantly alleviates the progression of pulmonary arterial hypertension. In summary, our study identifies BMPER as a novel therapeutic target for pulmonary arterial hypertension and provides new insights into the underlying mechanisms of the disease.

Scutellarein ameliorates pulmonary arterial hypertension via sirtuin 1 mediated deacetylation of nicotinamide nucleotide transhydrogenase

Scutellarein (Sc), a natural flavonoid, holds potential for treating pulmonary arterial hypertension (PAH), yet its mechanisms remain unexplored. This study investigated Sc's therapeutic effects and underlying pathways in PAH. In vivo experiments demonstrated that Sc significantly attenuated right ventricular hypertension, pulmonary arterial remodeling, αSMA expression, and vascular inflammation in PAH models. In vitro, Sc suppressed hypoxia-induced proliferation, migration, inflammation, and pyroptosis in human pulmonary artery smooth muscle cells (HPASMCs). Mechanistically, Sc activated the SIRT1/NAD+ axis to restore mitochondrial homeostasis: it upregulated SIRT1 expression and elevated NAD+ levels by promoting SIRT1-mediated deacetylation of nicotinamide nucleotide transhydrogenase (NNT), thereby enhancing NNT activity. Elevated NAD+ further activated SIRT1, forming a self-reinforcing SIRT1/NNT/NAD+ feedback loop that mitigated hypoxia-induced mitochondrial dysfunction. This study identifies Sc as a novel regulator of the SIRT1-dependent NNT deacetylation pathway, which stabilizes NAD+ homeostasis to counteract HPASMCs dysregulation in PAH. These findings highlight Sc's potential as a therapeutic candidate for PAH, offering insights into targeting mitochondrial-metabolic pathways for vascular remodeling diseases.

Natural products and ferroptosis: A novel approach for heart failure management

BACKGROUND

The discovery of ferroptosis has brought a revolutionary breakthrough in heart failure treatment, and natural products, as a significant source of drug discovery, are gradually demonstrating their extraordinary potential in regulating ferroptosis and alleviating heart failure symptoms. In addition to chemically synthesized small molecule compounds, natural products have attracted attention as an important source for discovering compounds that target ferroptosis in treating heart failure.

PURPOSE

Systematically summarize and analyze the research progress on improving heart failure through natural products' modulation of the ferroptosis pathway.

METHODS

By comprehensively searching authoritative databases like PubMed, Web of Science, and China National Knowledge Infrastructure with keywords such as "heart failure", "cardiovascular disease", "heart disease", "ferroptosis", "natural products", "active compounds", "traditional Chinese medicine formulas", "traditional Chinese medicine", and "acupuncture", we aim to systematically review the mechanism of ferroptosis and its link with heart failure. We also want to explore natural small-molecule compounds, traditional Chinese medicine formulas, and acupuncture therapies that can inhibit ferroptosis to improve heart failure.

RESULTS

In this review, we not only trace the evolution of the concept of ferroptosis and clearly distinguish it from other forms of cell death but also establish a comprehensive theoretical framework encompassing core mechanisms such as iron overload and system xc-/GSH/GPX4 imbalance, along with multiple auxiliary pathways. On this basis, we innovatively link ferroptosis with various types of heart failure, covering classic heart failure types and extending our research to pre-heart failure conditions such as arrhythmia and aortic aneurysm, providing new insights for early intervention in heart failure. Importantly, this article systematically integrates multiple strategies of natural products for interfering with ferroptosis, ranging from monomeric compounds and bioactive components to crude extracts and further to traditional Chinese medicine formulae. In addition, non-pharmacological means such as acupuncture are also included.

CONCLUSION

This study fills the gap in the systematic description of the relationship between ferroptosis and heart failure and the therapeutic strategies of natural products, aiming to provide patients with more diverse treatment options and promote the development of the heart failure treatment field.

TCF7 enhances pulmonary hypertension by boosting stressed natural killer cells and their interaction with pulmonary arterial smooth muscle cells

BACKGROUND

Pulmonary hypertension (PH) is a life-threatening cardio-pulmonary disorder. Whether natural killer (NK) cells could act as participants in PH and the mechanism by which NK cells moderate pulmonary vascular remodeling has not been fully elucidated.

METHODS

Single-cell RNA sequencing data from lungs of human pulmonary arterial hypertension (PAH) patients and monocrotaline (MCT)-induced PH rat model were retrieved from GEO database or UCSC Cell Browser. Tcf7 conditional knockout mice and TCF7 overexpression following adeno-associated virus 6 (AAV6) intratracheal delivery in rats were generated. The NK92 cell line and primary human pulmonary artery smooth muscle cells (hPASMCs) were used for in vitro experiments.

RESULTS

Stressed NK cells were much higher in lungs from human PAH and MCT-induced PH compared to corresponding controls. Of note, TCF7 topped the list differentiating high-stressed from low-stressed human NK cells. TCF7-expressing NK cells displayed higher stress profile than TCF7-deficient cells. Tcf7-deficient NK cells exhibited lower Hsp90aa1 and Hsp90ab1 at transcriptional level and Hsp90 at protein level than Tcf7-expressing cells 24 h post-hypoxia. Mechanistically, TCF7-overexpressing NK cells secrete more SPP1 compared to control NK cells, thus promoting the proliferation and migration of hPASMCs 48 h post-hypoxia. TCF7 overexpression in rats aggravated PH features, while Tcf7 deficiency in mice alleviated pulmonary remodeling possibly due to the manipulation of HSP90 level in NK cells and SPP1 in the microenvironment.

CONCLUSIONS

TCF7 contributes to the immunopathology of PH possibly through upregulation of stressed NK cells. Under stress conditions, NK cells promote the proliferation and migration of hPASMC through paracrine effects, thereby further promoting vascular remodeling.

Histone lactylation-derived prelamin A accelerates pulmonary arterial smooth muscle cells senescence in hypoxia-induced pulmonary hypertension rats

Pulmonary hypertension (PH) is an incurable disease, pulmonary arterial smooth muscle cells (PASMCs) senescence induces PASMCs proliferation by secreting interleukin 6 (IL-6), thereby promoting vascular remodeling. Accumulation of prelamin A is an important initial event at the onset of cellular senescence. Studies have shown that prelamin A has played a crucial role in the senescence-associated cardiovascular disease. However, the role of prelamin A in PH remains to be elucidated. This study aimed to elucidate how prelamin A accelerates PASMCs senescence and its regulatory mechanisms in hypoxia-induced pulmonary hypertension (HPH). Our findings demonstrated increased vascular remodeling and PASMCs senescence in HPH rats, notably, we observed upregulation of prelamin A and histone lactylation in these rats. Inhibiting histone lactylation resulted in decreased prelamin A expression, which consequently mitigated PASMCs senescence and alleviated vascular remodeling in HPH rats. And in 2-DG-treated HPH rats, overexpression of prelamin A reversed defective PASMCs senescence and vascular remodeling. These findings suggest that prelamin A accelerates PASMCs senescence, senescent PASMCs can promote PASMCs proliferation by secreting IL-6, and its upstream regulatory mechanism involves the up-regulation of lactylation modification of histone.

Potential of Sivelestat for Pulmonary Arterial Hypertension Treatment: Network Pharmacology-Based Target Identification and Mechanistic Exploration

Background

Sivelestat is a specific neutrophil elastase inhibitor that is currently approved for the treatment of acute lung injury and acute respiratory distress syndrome. Given sivelestat's established anti-inflammatory and antioxidant properties, its efficacy in treating pulmonary arterial hypertension (PAH) remains uncertain. This study aims to investigate the potential of sivelestat as a treatment for PAH.

Methods

Sivelestat's effects on PAH were evaluated using hypoxia-induced rat models (10% O2, 4 weeks) and pulmonary arterial endothelial/smooth muscle cells (1% O2). Rats received sivelestat (20-100 mg/kg) for 2 weeks, with hemodynamic (RVSP) and vascular remodeling (%WT) assessments. In vitro, sivelestat (50-200 μM) suppressed hypoxia-driven proliferation (CCK-8, EdU), migration (Transwell), and angiogenesis. Molecular validation via qPCR/Western blot confirmed reduced expression of key targets (IGF1R, JAK1, JAK2, PDGFRB).

Results

Through predictive analysis, we identified 595 potential genes associated with sivelestat in the treatment of PAH. Notably, ERBB2, IGF1R, JAK1, JAK2, PDGFRB, and PTPN11 emerged as key hub genes. In vivo experiments demonstrated that administration of sivelestat at a dose of 100 mg/kg significantly reduced PAH and improved pulmonary vascular remodeling. In vitro experiments indicated that sivelestat effectively decreased the proliferation and migration of PAECs and PASMCs induced by hypoxia.

Conclusion

Sivelestat has the potential to treat PAH through various targets and pathways. We have initially elucidated the molecular mechanism by which sivelestat acts in the treatment of PAH and have conducted preliminary validation through molecular docking studies and experimental approaches.

Pulmonary artery denervation in pulmonary hypertension: A comprehensive meta-analysis

INTRODUCTION

Pulmonary hypertension (PH) is a serious condition characterized by increased pulmonary vascular resistance and elevated pulmonary artery pressure, leading to right heart failure and high mortality rates. Conventional treatments primarily include vasodilators, which provide symptomatic relief but do not effectively reverse the underlying vascular pathology. Pulmonary artery denervation (PADN) has emerged as a novel therapeutic approach targeting the sympathetic nervous system's role in PH.

OBJECTIVE

This meta-analysis aims to evaluate the impact of PADN on hemodynamic parameters, including mean right atrial pressure (mRAP), mean pulmonary artery pressure (mPAP), and pulmonary vascular resistance (PVR), in patients with pulmonary hypertension.

METHODS

A comprehensive literature search was conducted across PubMed, Embase, Web of Science, and the Cochrane Library, covering studies published until September 2023. The inclusion criteria focused on studies involving human subjects with PH undergoing PADN, reporting relevant hemodynamic outcomes. Data from 14 studies were analyzed using Review Manager 5.3. Continuous outcomes were pooled using mean differences (MD) with 95 % confidence intervals (CI), and the random effects model was applied where significant heterogeneity was detected.

RESULTS

The meta-analysis included data from 14 studies comprising 372 patients. PADN resulted in significant reductions in mRAP (MD -1.71 mmHg, 95 % CI -2.34 to -1.08, p < 0.00001, I2 = 15 %), mPAP (MD -10.64 mmHg, 95 % CI -14.33 to -6.95, p < 0.00001, I2 = 84 %), and PVR (MD -4.69 Wood units, 95 % CI -6.55 to -2.83, p < 0.00001, I2 = 93 %). Additionally, there was a significant increase in cardiac output (CO) (MD 0.44 L/min, 95 % CI 0.25 to 0.62, p < 0.00001, I2 = 71 %) and 6-min walk distance (6MWD) (MD 62.4 m, 95 % CI 20.99 to 103.81, p = 0.003, I2 = 94 %).

CONCLUSION

PADN shows promise as a therapeutic intervention for PH, significantly improving key hemodynamic parameters and exercise capacity. However, the substantial heterogeneity observed among studies highlights the need for standardized procedures and further high-quality, long-term randomized controlled trials to validate these findings and refine patient selection criteria. The results support the potential of PADN to enhance current treatment strategies for pulmonary hypertension.

Mechanotransductive stabilization of HIF-1α is inhibited by mitochondrial antioxidant therapy in the setting of pulmonary overcirculation

In patients with congenital heart disease, the development of pulmonary arterial hypertension (PAH) is based on vascular exposure to abnormal hemodynamic forces. In our work using a large animal model of increased pulmonary blood flow and pressure, we have previously described a pattern of alterations to vascular cell metabolism, mitochondrial function, and mitochondrial redox signaling, paralleling changes in advanced pulmonary vasculopathy states. Based on our findings and emerging literature, we believe that endothelial mitochondria play a central role in integrating and relaying pathologic mechanotransductive signals in abnormal pulmonary hemodynamics. In this manuscript, we demonstrate that exposure of the pulmonary vascular endothelium to aberrant mechanical forces increases production of mitochondrial reactive oxygen species (ROS) and stabilizes the transcription factor Hypoxia Inducible Factor-1α (HIF-1α), and that these changes are associated with impaired endothelial production of Nitric Oxide (NO). We validate that the mitochondrial antioxidant 10-(6'-ubiquinonyl)decyltriphenylphosphonium bromide (MitoQ) can reverse these alterations in vitro, and evaluate the effects of MitoQ treatment in vivo utilizing our large animal shunt model. We find that MitoQ therapy in pulmonary overcirculation decreases the production of mitochondrial ROS, diminishes the mechanically-induced stabilization of HIF-1α, and partially restores vascular reactivity by rescuing endothelial NO production. These findings raise exciting prospects concerning shared pathophysiologic mechanisms and possible common therapeutic targets amongst PAH etiologies.

The Challenge in Burden of Pulmonary Arterial Hypertension: A Perspective From the Global Burden of Disease Study

Pulmonary arterial hypertension (PAH) poses significant clinical management challenges due to gaps in understanding its global epidemiology. We analyzed PAH-related disability-adjusted life years (DALYs), deaths, and prevalence from 1990 to 2021. Age-period-cohort models and regression analyses assessed temporal trends and projected burdens to 2050. Globally, PAH-related DALYs declined by 6.6%, but increased by 13.9% in high socio-demographic index (SDI) countries. Middle SDI regions reported the highest DALYs in 1990 and 2021. Deaths rose by 48.5% worldwide, with high SDI nations experiencing a 76.6% surge. Age-standardized rates (ASRs) of DALYs and deaths decreased across SDI countries, with high-middle SDI regions showing the steepest declines. Younger age groups, especially males, had a higher proportion of global DALYs in earlier years, but the burden shifted toward older populations over time, with this trend more pronounced in high-SDI countries. Age-period-cohort analysis revealed declining DALYs in younger ages but rising rates in older cohorts. By 2050, deaths and prevalence are projected to rise, disproportionately affecting females. Significant regional disparities in PAH burden persist, necessitating targeted policies, improved healthcare access, and early detection strategies, especially in underserved areas. Addressing these disparities is critical for mitigating PAH' s global impact.

Lingguizhugan decoction inhibit pulmonary hypertension by regulating macrophage IL-6 secretion via IL-33/ST2 pathway

BACKGROUND

Lingguizhugan decoction (LGZG), a typical Chinese herbal formula, has remarkable clinical effects for treating pulmonary hypertension (PH) with unclear ingredients and mechanisms. This study aimed to evaluate the efficacy of LGZG and the mechanism of its active ingredients in treating PH.

METHODS

The PH patient phenotype was characterized by transcriptomic assay of peripheral blood mononuclear cells (PBMCs) and multiplex cytokine profiling of serum. The active ingredients of LGZG were identified by UPLC-Q-TOF-MS. The monocrotaline (MCT)-induced PH model was performed to evaluate the effects of LGZG and its active ingredients in vivo. The interleukin-33 (IL-33)-induced RAW264.7 cells and the mouse pulmonary artery smooth muscle cells (mPASMCs) were applied to explored phenotype and mechanism of the active ingredients of LGZG by immunofluorescence, western blotting and RT-qPCR in vitro.

RESULTS

Inflammatory receptor activity in PBMCs and serum interleukin-6 (IL-6) levels were elevated in PH patients. Porinic acid B, cinnamic acid, atractylenolide I and glycyrrhizin (PCAG) were characterized and combined to treat the PH, And the IL-33/Growth stimulation expressed gene 2 (ST2) pathway may be the potential mechanism by transcriptomic analysis of lung tissues. Both in vivo and in vitro experiments confirmed that PCAG inhibited the IL-33/ST2 pathway, reduced macrophage polarization, and suppressed IL-6 secretion. Moreover, ST2 overexpression in macrophages attenuated the inhibitory effect of PCAG. Using a co-culture system of macrophages and mPASMCs, we demonstrated that PCAG reduced mPASMCs phenotypic switching by suppressing macrophage-derived IL-6 secretion.

CONCLUSION

The active ingredient of LGZG, PCAG, inhibits the progression of PH by preventing macrophage polarization and IL-6 secretion through the IL-33/ST2 pathway.

Advances in management of pulmonary fibrosis

Pulmonary fibrosis care, affecting both idiopathic pulmonary fibrosis and other forms of interstitial lung disease (ILD) characterised by fibrosis, has transformed with a range of innovations that affect the diagnosis, treatment and prognosis of this condition. Pharmacotherapeutic options have expanded, with increased indications for the application of effective antifibrotic therapy in non-IPF progressive pulmonary fibrosis as a solo treatment or combined with immunosuppression, emerging evidence for immunomodulatory therapy including biologic agents and greater access to clinical trials. The diagnostic approach to unclassifiable ILD now includes transbronchial lung cryobiopsy, a less invasive method to obtain histopathology with reduced morbidity and mortality compared to surgical lung biopsy. A multidisciplinary approach optimises the care of people with ILD and includes non-pharmacological management, addressing significant comorbidities, symptom care and advanced care planning. This review will summarise recent updates in pulmonary fibrosis management.

Intranasal delivery of R8-modified circNFXL1 liposomes ameliorates Su5416-induced pulmonary arterial hypertension in C57BL/6 mice

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive, life-threatening condition characterized by increased pulmonary vascular resistance and right ventricular hypertrophy (RVH). Current treatments primarily alleviate symptoms but do not effectively target the underlying molecular mechanisms driving the disease. This study aimed to evaluate the therapeutic potential of R8-modified liposomal delivery of circNFXL1, a circular RNA, in a mouse model of PAH.

METHODS

R8-circNFXL1 liposomes were synthesized and characterized for their physicochemical properties, including encapsulation efficiency. PAH was induced in C57BL/6 mice using a combination of subcutaneous Su5416 administration and hypoxic exposure. Intranasal delivery of R8-circNFXL1 was performed, and therapeutic effects were assessed using echocardiography and hemodynamic measurements. Molecular mechanisms were explored through analysis of the miR-29b/Kcnb1 axis, a regulatory pathway in PAH.

RESULTS

The R8-circNFXL1 liposomes demonstrated optimal physicochemical properties, including high encapsulation efficiency. Treatment with R8-circNFXL1 significantly reduced RVH, improved cardiac function, and mitigated pulmonary vascular remodeling compared to untreated PAH controls. Molecular analysis revealed that R8-circNFXL1 modulated the miR-29b/Kcnb1 axis, providing insights into its mechanism of action.

CONCLUSIONS

R8-circNFXL1 liposomes offer a promising, targeted therapeutic strategy for PAH by addressing underlying molecular mechanisms. This approach has potential implications for developing alternative treatments to improve disease management and outcomes in PAH.

Non-canonical HIPPO-MST1/2 promotes hyper-proliferation of pulmonary vascular cells through CDC20

HIPPO components mammalian Ste20-like protein kinases 1 and 2 (MST1/2) are well described growth suppressors. However, in pulmonary arterial hypertension (PAH), MST1/2 switch their roles and become pro-proliferative and pro-survival molecules, supporting hyper-proliferation of pulmonary artery (PA) smooth muscle cells (PASMCs) and adventitial fibroblasts (PAAFs), remodeling of small PAs, and pulmonary hypertension. Here, we report that MST1/2 promotes hyper-proliferation and apoptosis resistance of human PAH PASMCs and PAAFs by up-regulating cell division cycle protein 20 (CDC20), establishing novel link between HIPPO-MST1/2 and cell cycle regulation in PAH.

Authors Contributions

conception and design of the work (EAG, SSP, TVK); acquisition, analysis, and interpretation of data (TD, IZ, LJ, SOO, AP, TA, DL, DG, JRG, PJW, HD, TK); drafting and editing the manuscript (EAG, SSP, TVK, JRG, PJW).

SRSF4-Associated ca-circFOXP1 Regulates Hypoxia-Induced PASMC Proliferation by the Formation of R Loop With Host Gene

BACKGROUND

Pulmonary hypertension (PH) is a rare and fatal disease, the pathological changes of which include pulmonary arterial smooth muscle cell (PASMC) proliferation, which is the pathological basis of pulmonary vascular remodeling. Studies have demonstrated that chromatin-associated circRNA can regulate a variety of biological processes. However, the role of chromatin-associated circRNA in the proliferation of PH remains largely unexplored. In this study, we aimed to identify the function and mechanism of chromatin-associated circRNA in PASMC proliferation in PH.

METHODS

The role of chromatin-associated circFOXP1 (ca-circFOXP1) was investigated in hypoxic mouse PASMCs and SuHX (Sugen5416+hypoxia) model mice through the use of antisense oligonucleotide knockdown and adeno-associated virus-mediated knockdown. Through bioinformatic sequence alignment, chromatin isolation by RNA purification, Cell Counting Kit 8, 5-ethynyl-2-deoxyuridine, Western blot, and other experiments, the function and mechanism of ca-circFOXP1 were verified.

RESULTS

The expression of ca-circFOXP1 was found to be significantly increased in SuHX model mice and hypoxic mouse PASMCs. Moreover, ca-circFOXP1 was found to regulate the level of the host protein FOXP1 (forkhead box protein 1) through the R loop, thereby influencing the phosphorylation activity of SMAD2 (SMAD family member 2) and, consequently, the proliferation of mouse PASMCs. It is noteworthy that the m6A modification was found to promote the formation of the R loop between ca-circFOXP1 and the host gene FOXP1, thereby regulating the expression of the host protein. Furthermore, we have identified that the splicing factor SRSF4 (serine/arginine rich splicing factor 4) can upregulate the expression of ca-circFOXP1 by splicing exons 6 and 9 of FOXP1 pre-mRNA.

CONCLUSIONS

The results demonstrated that the splicing factor SRSF4 upregulated the expression of ca-circFOXP1, and m6A methylation promoted R-loop formation between ca-circFOXP1 and host genes, regulated the level of host protein FOXP1, and then affected the phosphorylation activity of SMAD2, mediating PASMC proliferation, leading to pulmonary vascular remodeling. These results provide a theoretical basis for further study of the pathological mechanisms of hypoxic PH and may provide certain insights.

Pulmonary Hypertension Associated with Interstitial Lung Disease (PH-ILD): Back to the Future

Pulmonary hypertension (PH) is a progressive syndrome characterized by increased pulmonary artery pressure. PH often complicates chronic lung diseases, thus contributing to a substantial disease burden and poor prognosis. The WHO Group 3 Pulmonary Hypertension has many subcategories, including sleep-hypoventilation PH, high altitude-PH, chronic obstructive pulmonary disease (COPD)-PH, and interstitial lung disease (PH-ILD), the latter carrying the worst prognosis. ILD is a heterogeneous group of disorders characterized by cough and shortness of breath and, in progressive forms, irreversible loss of function and respiratory failure. The development of PH in patients with ILD worsens exercise capacity and exertional dyspnea and impairs quality of life. Thus, suspicion and early detection of PH following thorough cardiologic evaluation (i.e., echocardiography, pro-BNP, and right heart catheterization) is paramount for appropriate patient management. For PH secondary to chronic respiratory diseases, current guidelines recommend optimizing the treatment of the underlying respiratory condition and offering long-term oxygen therapy. In recent years, several clinical trials have failed to identify drugs beneficial for group 3 PH. Conversely, the INCREASE trial of inhaled treprostinil has recently provided hope for treating PH-ILD. In this review, we summarize and critically discuss the present and future of the pharmacological management of PH-ILD.

Association of interferon regulator factor 1 upregulation with pulmonary arterial hypertension

Background

Pulmonary arterial hypertension (PAH) is a complex disease that is associated with a poor prognosis. Its pathogenesis is attributed to the inflammatory immune response. Interferon regulator factor 1 (IRF1) is a key downstream regulator of inflammation and cell death. Evidence suggests that IRF1 can promote the proliferation of smooth muscle cells and inhibit lung endothelial regeneration. However, proof for this relationship is lacking, and the exact nature of the potential mechanism underlying the link between IRF1 and PAH remains largely unknown. We aimed to find out whether IRF1 is associated with the progression of PAH.

Methods

The GSE144274 and GSE243193 datasets were obtained from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between PAH and healthy samples were identified and analyzed. Enrichment analysis was performed, and a protein-protein interaction (PPI) network was constructed to identify the hub genes. The relative protein and gene levels of IRF1 were then validated in PAH animal models.

Results

A total of 271 DEGs were identified from the two data sets. ACTA2, HLA-DRA, HLA-A, PECAM1, HLA-C, IRF1, and CD74 were identified as the hub genes. In our subsequent experiments, we found that IRF1 was upregulated in both PAH rat and mouse models.

Conclusions

Our findings suggest that IRF1 might be associated with pulmonary hypertension in lung tissue and may thus serve as a therapeutic target in PAH.

Identification of potential causal genes and drug targets in pulmonary hypertension based on transcriptomic analysis and Mendelian randomization

PURPOSE

Currently, there is no definitive treatment for pulmonary hypertension (PH). This study aims to utilize the GEO database and conduct Mendelian randomization (MR) analysis to identify new genetic targets for PH and investigate their potential pathogenic pathways and therapeutic drugs.

METHODS

We identified key genes by combining the findings from MR and bioinformatics analyses of GEO datasets. We performed enrichment analysis to explore the functional roles of these key genes. Then, we constructed protein-protein interaction (PPI) and miRNA-mRNA networks to identify interacting proteins and miRNAs. Drug prediction analysis was conducted to propose potential therapeutic drugs. Finally, we validated the results through the GEO dataset, RT-PCR, and western blot experiments.

RESULTS

The joint analysis utilizing GEO databases and MR analysis identified two key genes, ITGA2B and TSPAN9 that exhibited significance across both analytical methods. The enrichment analysis indicated that the key genes were involved in critical biological functions and pathways, including cell adhesion, platelet activation, and the PI3K-Akt signaling pathway. The PPI and miRNA-mRNA networks further highlighted the significance of the key genes in PH. Drug prediction analysis revealed the potential of the key genes as therapeutic targets. The RT-PCR and western blot experiments validated the above findings.

CONCLUSION

By integrating bioinformatics and MR analysis, we found that ITGA2B and TSPAN9 have a causal relationship with PH. Our findings offer new insights into the molecular mechanism and potential treatment targets of PH, establishing a basis for future research and clinical applications.

RNA-binding proteins as a molecular link between COPD and pulmonary hypertension

Pulmonary hypertension (PH) is a vascular disease characterized by remodeling of the pulmonary arteries and right heart failure. Chronic obstructive pulmonary disease (COPD) patients often have PH, which can worsen symptoms and raise morbidity and mortality. There are several reasons for increased pulmonary vascular resistance, pulmonary vascular remodeling, and ultimately the development of PH in COPD. These factors include genetics, inflammation caused by chemicals breathed, and changes in the alveoli seen in COPD and its physiology. Genes involved in mRNA conversion, subcellular localization, splicing, and translation are all finely tuned by RBPs in their post-transcriptional regulation. Erythropoietin regulates cytokines, chemokines, proteins, growth factors, and other pro-inflammatory mediators that change the lung microenvironment. Over the past few years, we have learned more about how RBPs act in PH and COPD. Here, we discuss the existing understanding of RBPs' location in the same pathogenic pathways shared by PH and COPD in order to emphasize their potential relevance as disease determinant/biomarker and, consequently, for possible therapeutic targeting.

A novel pyridine-2-one AMPK inhibitor: Discovery, mechanism, and in vivo evaluation in a hypoxic pulmonary arterial hypertension rat model

AMP-activated protein kinase (AMPK), a heterotrimeric serine-threonine kinase, has been identified as a promising target for regulating vascular remodeling in pulmonary arterial hypertension (PAH) due to its capacity to promote proliferation, autophagy, and anti-apoptosis in pulmonary artery smooth muscle cells (PASMCs). However, research into AMPK inhibitors is very limited. Herein, a virtual screening strategy was employed to identify CHEMBL3780091 as a lead compound for a series of novel AMPK inhibitors by exploring the structure-activity relationship around a specific pyridine-2-one scaffold. Subsequently, the most promising 13a was observed to exhibit excellent AMPK inhibitory activity and favorable anti-proliferative activity against PASMCs through the inhibition of the AMPK signaling pathway in vitro. Moreover, compound 13a significantly reduced right ventricular systolic pressure, attenuated vascular remodeling, and improved right heart function in hypoxia-induced PAH rats in vivo. In conclusion, this study provides a novel and potential lead compound for the study of AMPK inhibitors and a new direction for the development of PAH drugs that focus on improving vascular remodeling.

Validation of a non-invasive filling pressure (NIFP) device for measuring cardiac pressure and assessing congestion levels in patients with heart failure

BACKGROUND

Heart failure (HF) is a high-burden clinical syndrome characterized by intravascular and extravascular congestion, impacting patients' outcomes. Current diagnostic methods for assessing intravascular congestion, including right heart catheterization (RHC), have some limitations. There is a need for accurate, stable, and widely applicable non-invasive measurement methods to improve HF diagnosis and treatment.

METHODS

We conducted non-invasive filling pressure (NIFP) measurements in 74 patients before or after RHC. The correlation between recorded factors and pulmonary arterial wedge pressure (PAWP) values was examined. We tested NIFP's performance as a predictive tool for PAWP using different thresholds. Receiver operating characteristic (ROC) curve analysis and Pearson correlation coefficient were used for data analysis.

RESULTS

NIFP measurement served as an independent impact factor and showed a definite relationship with PAWP in both univariate and multivariate regression analyses (all p < 0.05). NIFP demonstrated moderate accuracy in predicting PAWP values (all AUC > 0.75), particularly among patients without arrhythmia [AUC for Model 1 (PAWP >15): 0.80; AUC for Model 2 (PAWP >18): 0.85].

CONCLUSIONS

The NIFP device represents a promising innovation, offering non-invasive and user-friendly solution for precisely measuring pulmonary arterial wedge pressure (PAWP) and assessing the degree of congestion.

Mechanistic insights into the role of EGLN3 in pulmonary vascular remodeling and endothelial dysfunction

Endothelial dysfunction is a pivotal initiating factor in vascular remodeling in pulmonary hypertension. EGLN3, a hypoxia response factor, plays a significant role in cell proliferation and angiogenesis, which are closely related to the pathophysiological conditions of pulmonary hypertension. This study investigates the potential involvement of EGLN3 in the injury response of pulmonary vascular endothelial cells and its contribution to the development of pulmonary arterial hypertension. Research has demonstrated that in patients with pulmonary arterial hypertension and various animal models of the condition, EGLN3 expression is upregulated in the remodeled pulmonary artery endothelium. Notably, the endothelial cell-specific knockout of EGLN3 can decelerate the progression of pulmonary arterial hypertension, whereas its overexpression has the opposite effect. Mechanistic analyses reveal that under hypoxic conditions, JUN initiates the transcription of EGLN3 by binding to its promoter region. Subsequently, EGLN3 interacts with HUR to enhance the stability of EGFR mRNA, thereby activating the PI3K/AKT and MAPK signaling pathways, which ultimately results in endothelial cell damage, proliferation, and migration. These findings suggest that EGLN3 is a critical gene for maintaining endothelial function and vascular homeostasis and holds promise as a novel therapeutic target for the treatment of pulmonary hypertension.

Chloroquine Restores eNOS Signaling in Shunt Endothelial Cells via Inhibiting eNOS Uncoupling

Pulmonary arterial hypertension (PAH) is characterized by increased lung vascular stiffness and impaired vessel relaxation, primarily due to reduced nitric oxide (NO) production in endothelial cells. Recent studies indicate that chloroquine, an autophagy inhibitor, may help lower pulmonary arterial pressure and enhance lung vascular function. This study investigates the mechanisms underlying the chloroquine-mediated restoration of NO bioavailability in endothelial cells derived from aortopulmonary shunt lambs, a relevant model for congenital heart defect (CHD)-associated PAH. We found that NO production was significantly reduced in shunt pulmonary artery endothelial cells (PAECs), attributable to decreased levels of tetrahydrobiopterin (BH4) and diminished expression of GTP cyclohydrolase 1 (GCH1), despite a slight increase in endothelial nitric oxide synthase (eNOS) levels. Chloroquine robustly restored endothelial NO production, which correlated with increased BH4 levels and restored GCH1 expression. The mechanistically upregulated carboxyl terminus of Hsp70-interacting protein (CHIP) in shunt PAECs is responsible for heightened GCH1 degradation, and chloroquine disrupted the assembly of the GCH1-HSP70-CHIP complex to preserve cellular GCH1. Similarly, another autophagy inhibitor, bafilomycin A1, demonstrated comparable effects. These findings suggest that autophagy inhibition can effectively enhance NO synthesis in endothelial cells experiencing depleted NO bioavailability, presenting a potential therapeutic strategy for managing PAH.

MMP8-mediated vascular remodeling in pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a vascular remodeling disease that impacts the cardiopulmonary system. Due to the currently limited understanding of vascular remodeling, a cure for PAH remains elusive. This study highlights the critical role of the STAT1 (signal transducer and activator of transcription 1)/MMP8 (matrix metallopeptidase 8)/DRP1 (dynamin-related protein 1) axis in vascular remodeling and the pathogenesis of pulmonary hypertension. Notably, MMP8 is significantly elevated in pulmonary arterial endothelial cells and its levels correlate with the severity of the disease. MMP8 binds to and activates DRP1, inducing mitochondrial fragmentation and promoting a malignant phenotype of endothelial cells under hypoxic conditions. Moreover, MMP8 is tightly regulated by STAT1. The knockout of MMP8 attenuates chronic pulmonary vascular remodeling, and drugs targeting MMP8 alleviate pulmonary hypertension and enhance cardiac function. This study offers fresh insights into hypoxia-induced vascular remodeling, laying a theoretical foundation for countering vascular remodeling by directly regulating the STAT1/MMP8/DRP1 axis.

Noncoding RNA Lipotherapeutics: A Promising Breakthrough in Pulmonary Hypertension Treatment

Pulmonary Hypertension (PH) is a complex cardiovascular disorder characterized by elevated blood pressure in the pulmonary arteries. Current therapeutic approaches for PH have limitations in addressing the underlying molecular mechanisms. This article explores the potential of noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), delivered through Lipid-Based Nanoparticles (LNPs) as a novel treatment strategy. These ncRNAs play critical roles in regulating vascular function and are implicated in PH pathogenesis. LNPs provide a promising method for the efficient and targeted delivery of ncRNAs. Advances in LNP technology, including the incorporation of R8 peptide modification, have shown promise in enhancing the delivery and efficacy of ncRNAs in PH models. Challenges such as biocompatibility, toxicity, and precise targeting must be addressed as these therapies move toward clinical application. The potential of personalized medicine and the integration of artificial intelligence in LNP design are discussed as prospects. In conclusion, ncRNA lipotherapeutics delivered via LNPs offer a transformative approach to treating PH, potentially leading to more effective management and improved patient outcomes in the future. However, continued research and clinical trials are necessary to fully realize their therapeutic potential in the field of PH treatment.

Liver Kinase B1 Protects Against Hypoxia-Induced Pulmonary Arterial Endothelial Cell Dysfunction via the AMP-Activated Protein Kinase Pathway

Pulmonary hypertension (PH) is a progressive disease characterized by vascular reHypoxiaing, endothelial cell dysfunction, and inflammation. Liver Kinase B1 (LKB1, also known as STK11) is a central regulator of cell polarity and energy homeostasis. However, its specific role and mechanism of action in PH remain unclear. Human pulmonary arterial endothelial cells (hPAECs) were cultured in vitro to establish PH cell Hypoxias under normoxic and hypoxic conditions. The expression of LKB1 was detected by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and western blotting, and its effect on hPAECs function was investigated by overexpression and inhibition of LKB1. Furthermore, cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, apoptosis was measured by flow cytometry, inflammatory cytokine secretion was evaluated using enzyme-linked immunosorbent assay (ELISA), and the expression of AMP-activated protein kinase (AMPK) signaling pathway-related proteins was analyzed by western blotting. LKB1 expression was significantly reduced in hypoxia-treated hPAECs compared with that in normoxic controls, and LKB1 overexpression significantly ameliorated the hypoxia-induced decrease in cell proliferation and increase in apoptosis as well as inflammatory factor secretion. The AMPK agonist (GSK621) reversed the dysfunction caused by LKB1 inhibition, indicating that LKB1 regulates hPAECs function through the AMPK signaling pathway. LKB1 plays a protective role in PH by inhibiting hPAECs dysfunction via activation of the AMPK pathway.

SGLT2 inhibitors as a potential therapeutic option for pulmonary hypertension: mechanisms and clinical perspectives

Pulmonary arterial hypertension (PAH), one subtype of pulmonary hypertension (PH), is a life-threatening condition characterized by pulmonary arterial remodeling, elevated pulmonary vascular resistance, and blood pressure in the pulmonary arteries, leading to right heart failure and increased mortality. The disease is marked by endothelial dysfunction, vasoconstriction, and vascular remodeling. The role of Sodium-Glucose Co-Transporter-2 (SGLT2) inhibitors, a class of medications originally developed for diabetes management, is increasingly being explored in the context of cardiovascular diseases, including PAH, due to their potential to modulate these pathophysiological processes. In this review, we systematically examine the burgeoning evidence from both basic and clinical studies that describe the effects of SGLT2 inhibitors on cardiovascular health, with a special emphasis on PAH. By delving into the complex interactions between these drugs and the potential pathobiology that underpins PH, this study seeks to uncover the mechanistic underpinnings that could justify the use of SGLT2 inhibitors as a novel therapeutic approach for PAH. We collate findings that illustrate how SGLT2 inhibitors may influence the normal function of pulmonary arteries, possibly alleviating the pathological hallmarks of PAH such as inflammation, oxidative stress, aberrant cellular proliferation, and so on. Our review thereby outlines a potential paradigm shift in PAH management, suggesting that these inhibitors could play a crucial role in modulating the disease's progression by targeting the potential dysfunctions that drive it. This comprehensive synthesis of existing research underscores the imperative need for further clinical trials to validate the efficacy of SGLT2 inhibitors in PAH and to integrate them into the therapeutic agents used against this challenging disease.

A new perspective on targeting pulmonary arterial hypertension: Programmed cell death pathways (Autophagy, Pyroptosis, Ferroptosis)

Pulmonary arterial hypertension (PAH) is a severe cardiovascular disease characterized by elevated pulmonary vascular resistance, progressive increases in pulmonary artery pressures, ultimately leading to right-sided heart failure, and potentially mortality. Pulmonary vascular remodeling is pivotal in PAH onset and progression. While targeted drug therapies have notably ameliorated PAH prognosis, current medications primarily focus on vascular vasodilation, with limited ability to reverse pulmonary vascular remodeling fundamentally, resulting in suboptimal patient prognoses. Cellular death in pulmonary vasculature, once thought to be confined to apoptosis and necrosis, has evolved with the identification of pyroptosis, autophagy, and ferroptosis, revealing their association with vascular injury in PAH. These novel forms of regulated cellular death impact reactive oxygen species (ROS) generation, calcium stress, and inflammatory cascades, leading to pulmonary vascular cell loss, exacerbating vascular injury, and mediating adverse remodeling, inflammation, immune anomalies, and current emerging mechanisms (such as endothelial-mesenchymal transition, abnormal energy metabolism, and epigenetic regulation) in the pathogenesis of PAH. This review comprehensively delineates the roles of autophagy, pyroptosis, and ferroptosis in PAH, elucidating recent advances in their involvement and regulation of vascular injury. It juxtaposes their distinct functions in PAH and discusses the interplay of these programmed cell deaths in pulmonary vascular injury, highlighting the benefits of combined targeted therapies in mitigating pulmonary arterial hypertension-induced vascular injury, providing novel insights into targeted treatments for pulmonary arterial hypertension.

Causal associations between telomere length and pulmonary arterial hypertension: A two-sample Mendelian randomization study

Pulmonary arterial hypertension (PAH) is a life-threatening condition characterized by elevated pulmonary artery pressure, leading to right heart failure, and mortality. The role of telomere length, a marker of biological aging, in PAH remains unclear. We utilized summary-level data from genome-wide association studies for various measures of telomere length and PAH. Single nucleotide polymorphisms associated with telomere length at a genome-wide significance level were used as instrumental variables. The inverse variance weighted method was the primary analysis, with sensitivity analyses including the weighted median and Mendelian randomization-Egger regression. The odds ratios and 95% confidence intervals (CI) were calculated to estimate the causal effect of telomere length on PAH risk. The Mendelian randomization analyses revealed no significant causal association between overall telomere length and PAH (odds ratios per standard deviation increase = 1.229, 95% CI: 0.469-3.222, P = .676). Similar null findings were observed for granulocyte, lymphocyte, naive T-cell, memory T-cell, B-cell, and natural killer-cell telomere lengths. Sensitivity analyses confirmed the robustness of the results, with no evidence of horizontal pleiotropy or significant influence of individual single nucleotide polymorphisms on the overall estimates. This Mendelian randomization study didn't support a causal association between telomere length and PAH.

Cardiac MRI in Rheumatic Disease

Immune-mediated systemic inflammatory disorders present a latent threat for cardiovascular disease. Early involvement may be associated with constitutional symptoms, while clinical evidence of disease may manifest later in an insidious manner. Multimodality imaging is crucial to detect myocardial involvement, with transthoracic echocardiogram as a first-line imaging modality; however, cardiac MRI (CMRI) has the potential to significantly impact our diagnostic and therapeutic approaches through high-fidelity chamber quantification and parametric mapping techniques. Novel imaging techniques are currently under investigation, including stress CMRI, feature tracking CMR, late gadolinium enhancement (LGE) entropy, and 4 dimensional flow CMRI.

Dihydromyricetin treats pulmonary hypertension by modulating CKLF1/CCR5 axis-induced pulmonary vascular cell pyroptosis

Pulmonary hypertension (PH) is a progressive cardiopulmonary disease characterized by elevated pulmonary artery pressure and vascular remodeling, resulting in poor prognosis and increased mortality rates. Chemokine-like factor 1 (CKLF1) plays a significant role in inducing inflammation and cell proliferation, both of which are critical processes in the pathogenesis of various diseases. Dihydromyricetin (DMY) has garnered attention for its potent anti-inflammatory properties. This study evaluated the protective effects of DMY against PH, demonstrating that DMY treatment can mitigate pyroptosis in pulmonary artery endothelial cells (PAECs) and pulmonary artery smooth muscle cells (PASMCs) in vivo via the CKLF1/CCR5 axis. Results indicated significant improvements in hemodynamics, inflammatory responses, fibrosis, vascular remodeling, and right ventricular hypertrophy in PH rats following DMY treatment. Furthermore, the interaction between CKLF1 and CCR5 was investigated in CKLF1-/- rats after PH induction. DMY was found to downregulate CKLF1 expression and the inflammatory response in the lungs, with its therapeutic efficacy diminished following CKLF1 knockdown. This study underscores the therapeutic potential of DMY in the management of PH and lays a foundation for future research and clinical applications.

Arginine methylation and respiratory disease

Arginine methylation, a vital post-translational modification, plays a pivotal role in numerous cellular functions such as signal transduction, DNA damage response and repair, regulation of gene transcription, mRNA splicing, and protein interactions. Central to this modification is the role of protein arginine methyltransferases (PRMTs), which have been increasingly recognized for their involvement in the pathogenesis of various respiratory diseases. This review begins with an exploration of the biochemical underpinnings of arginine methylation, shedding light on the intricate molecular regulatory mechanisms governed by PRMTs. It then delves into the impact of arginine methylation and the dysregulation of arginine methyltransferases in diverse pulmonary disorders. Concluding with a focus on the therapeutic potential and recent advancements in PRMT inhibitors, this article aims to offer novel perspectives and therapeutic avenues for the management and treatment of respiratory diseases.

miR-135b: An emerging player in cardio-cerebrovascular diseases

miR-135 is a highly conserved miRNA in mammals and includes miR-135a and miR-135b. Recent studies have shown that miR-135b is a key regulatory factor in cardio-cerebrovascular diseases. It is involved in regulating the pathological process of myocardial infarction, myocardial ischemia/reperfusion injury, cardiac hypertrophy, atrial fibrillation, diabetic cardiomyopathy, atherosclerosis, pulmonary hypertension, cerebral ischemia/reperfusion injury, Parkinson's disease, and Alzheimer's disease. Obviously, miR-135b is an emerging player in cardio-cerebrovascular diseases and is expected to be an important target for the treatment of cardio-cerebrovascular diseases. However, the crucial role of miR-135b in cardio-cerebrovascular diseases and its underlying mechanism of action has not been reviewed. Therefore, in this review, we aimed to comprehensively summarize the role of miR-135b and the signaling pathway mediated by miR-135b in cardio-cerebrovascular diseases. Drugs targeting miR-135b for the treatment of diseases and related patents, highlighting the importance of this target and its utility as a therapeutic target for cardio-cerebrovascular diseases, have been discussed.

Advances in the potential of nebulized inhalation for the treatment of pulmonary arterial hypertension

Pulmonary hypertension is a pathophysiologic manifestation of a heterogeneous group of diseases, with the main pathophysiologic mechanisms being persistent pulmonary vasoconstriction and irreversible vascular remodeling. The impact significantly affects the prognosis of patients with pulmonary hypertension. If it is not treated and intervened in time, it may lead to right ventricular failure and further endanger the patient's life. Within the past decade or so, nebulized inhalation therapy is considered to have advantages in the treatment of pulmonary hypertension as a safe, limited, and rapid therapy, for example, inhaled vasodilators (prostate analogs, nitroglycerin, carbon monoxide analogs sildenafil, and nitroprusside), inhaled anti-inflammatory and antiproliferative agents (simvastatin, and selatinib), and inhaled peroxides (levocetirizine) have been recognized as emerging therapeutic approaches in the treatment of pulmonary hypertension as emerging therapeutic approaches. Therefore, this article provides a brief review of recent advances in the potential of nebulized inhaled vasodilators, anti-inflammatory and antiproliferative agents, and anti-peroxides for the treatment of pulmonary hypertension, with the aim of providing different therapeutic options for the treatment of pulmonary hypertension, enhancing the quality of survival, alleviating symptoms, and improving the prognosis of patients with this condition.

A comprehensive analysis of genes associated with hypoxia and cuproptosis in pulmonary arterial hypertension using machine learning methods and immune infiltration analysis: AHR is a key gene in the cuproptosis process

Background

Pulmonary arterial hypertension (PAH) is a serious condition characterized by elevated pulmonary artery pressure, leading to right heart failure and increased mortality. This study investigates the link between PAH and genes associated with hypoxia and cuproptosis.

Methods

We utilized expression profiles and single-cell RNA-seq data of PAH from the GEO database and genecad. Genes related to cuproptosis and hypoxia were identified. After normalizing the data, differential gene expression was analyzed between PAH and control groups. We performed clustering analyses on cuproptosis-related genes and constructed a weighted gene co-expression network (WGCNA) to identify key genes linked to cuproptosis subtype scores. KEGG, GO, and DO enrichment analyses were conducted for hypoxia-related genes, and a protein-protein interaction (PPI) network was created using STRING. Immune cell composition differences were examined between groups. SingleR and Seurat were used for scRNA-seq data analysis, with PCA and t-SNE for dimensionality reduction. We analyzed hub gene expression across single-cell clusters and built a diagnostic model using LASSO and random forest, optimizing parameters with 10-fold cross-validation. A total of 113 combinations of 12 machine learning algorithms were employed to evaluate model accuracy. GSEA was utilized for pathway enrichment analysis of AHR and FAS, and a Nomogram was created to assess risk impact. We also analyzed the correlation between key genes and immune cell types using Spearman correlation.

Results

We identified several diagnostic genes for PAH linked to hypoxia and cuproptosis. PPI networks illustrated relationships among these hub genes, with immune infiltration analysis highlighting associations with monocytes, macrophages, and CD8 T cells. The genes AHR, FAS, and FGF2 emerged as key markers, forming a robust diagnostic model (NaiveBayes) with an AUC of 0.9.

Conclusion

AHR, FAS, and FGF2 were identified as potential biomarkers for PAH, influencing cell proliferation and inflammatory responses, thereby offering new insights for PAH prevention and treatment.

PAI-1 deficiency drives pulmonary vascular smooth muscle remodeling and pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by vasoconstriction and remodeling of small pulmonary arteries (PAs). Central to the remodeling process is a switch of pulmonary vascular cells to a proliferative, apoptosis-resistant phenotype. Plasminogen activator inhibitors-1 and -2 (PAI-1 and PAI-2) are the primary physiological inhibitors of urokinase-type and tissue-type plasminogen activators (uPA and tPA), but their roles in PAH are unsettled. Here, we report that: 1) PAI-1, but not PAI-2, is deficient in remodeled small PAs and in early-passage PA smooth muscle and endothelial cells (PASMCs and PAECs) from subjects with PAH compared with controls; 2) PAI-1-/- mice spontaneously develop pulmonary vascular remodeling associated with upregulation of mTORC1 signaling, pulmonary hypertension (PH), and right ventricle (RV) hypertrophy; and 3) pharmacological inhibition of uPA in human PAH PASMCs suppresses proproliferative mTORC1 and SMAD3 signaling, restores PAI-1 levels, reduces proliferation, and induces apoptosis in vitro, and prevents the development of SU5416/hypoxia-induced PH and RV hypertrophy in vivo in mice. These data strongly suggest that downregulation of PAI-1 in small PAs promotes vascular remodeling and PH due to unopposed activation of uPA and consequent upregulation of mTOR and transforming growth factor-β (TGF-β) signaling in PASMCs, and call for further studies to determine the potential benefits of targeting the PAI-1/uPA imbalance to attenuate and/or reverse pulmonary vascular remodeling and PH.NEW & NOTEWORTHY This study identifies a novel role for the deficiency of plasminogen activator inhibitor (PAI)-1 and resultant unrestricted uPA activity in PASMC remodeling and PH in vitro and in vivo, provides novel mechanistic link from PAI-1 loss through uPA-induced Akt/mTOR and TGFβ-Smad3 upregulation to pulmonary vascular remodeling in PH, and suggests that inhibition of uPA to rebalance the uPA-PAI-1 tandem might provide a novel approach to complement current therapies used to mitigate this pulmonary vascular disease.

Effects of malnutrition on disease severity and adverse outcomes in idiopathic pulmonary arterial hypertension: a retrospective cohort study

BACKGROUND

Malnutrition is common in patients with chronic cardiovascular disease and is associated with significantly higher all-cause mortality. Approximately one-third of patients with heart failure are malnourished. However, the relationship between malnutrition and idiopathic pulmonary arterial hypertension (IPAH) remains unclear. This study aimed to clarify the prognostic value of malnutrition in patients with IPAH.

METHODS

A total of 432 consecutive participants with IPAH were included in this study between March 2013 and August 2021. Three common malnutrition assessment tools, including the geriatric nutritional risk index (GNRI), prognostic nutritional index (PNI), and controlling nutritional status (CONUT) score, were used to evaluate the nutritional status of patients with IPAH. The relationships between the malnutrition tools and long-term adverse outcomes were determined using restricted cubic splines and multivariate Cox regression models.

RESULTS

During a mean follow-up of 3.1 years, 158 participants experienced clinical worsening or all-cause death. Patients were stratified into the low-, intermediate- and high-risk groups based on the European Society of Cardiology (ESC) risk stratification, and the PNI (55.9 ± 5.7 vs. 54.4 ± 7.2 vs. 51.1 ± 7.1, P = 0.005) and CONUT score (2.1 ± 0.9 vs. 2.5 ± 1.2 vs. 3.3 ± 1.1, P < 0.001) identified these patient groups better than the GNRI. All three malnutrition tools were associated with well-validated variables that reflected IPAH severity, such as the World Health Organization functional class, 6-min walk distance, and N-terminal pro-brain natriuretic peptide level. The CONUT score exhibited better predictive ability than both the GNRI (ΔAUC = 0.059, P < 0.001) and PNI (ΔAUC = 0.095, P < 0.001) for adverse outcomes and significantly improved reclassification and discrimination beyond the ESC risk score. Multivariable Cox regression analysis indicated that only the CONUT score (hazard ratio = 1.363, 95% confidence interval 1.147, 1.619 per 1.0-standard deviation increment, P < 0.001) independently predicted adverse outcomes.

CONCLUSIONS

The malnutrition status was associated with disease severity in patients with IPAH. The CONUT score provided additional information regarding the risk of clinically worsening events, making it a meaningful risk stratification tool for these patients.

Decoding ferroptosis: Revealing the hidden assassin behind cardiovascular diseases

The discovery of regulatory cell death processes has driven innovation in cardiovascular disease (CVD) therapeutic strategies. Over the past decade, ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation, has been shown to drive the development of multiple CVDs. This review provides insights into the evolution of the concept of ferroptosis, the similarities and differences with traditional modes of programmed cell death (e.g., apoptosis, autophagy, and necrosis), as well as the core regulatory mechanisms of ferroptosis (including cystine/glutamate transporter blockade, imbalance of iron metabolism, and lipid peroxidation). In addition, it provides not only a detailed review of the role of ferroptosis and its therapeutic potential in widely studied CVDs such as coronary atherosclerotic heart disease, myocardial infarction, myocardial ischemia/reperfusion injury, heart failure, cardiomyopathy, and aortic aneurysm but also an overview of the phenomenon and therapeutic perspectives of ferroptosis in lesser-addressed CVDs such as cardiac valvulopathy, pulmonary hypertension, and sickle cell disease. This article aims to integrate this knowledge to provide a comprehensive view of ferroptosis in a wide range of CVDs and to drive innovation and progress in therapeutic strategies in this field.

Therapeutic potential of natural flavonoids in pulmonary arterial hypertension: A review

BACKGROUND

Pulmonary arterial hypertension (PAH) is a fatal disease caused by pulmonary vascular remodeling, with a high incidence and mortality. At present, many clinical drugs for treating PAH mainly exert effects by relaxing the pulmonary artery, with limited therapeutic effects, so the search for viable therapeutic agents continues uninterrupted. In recent years, natural flavonoids have shown promising potential in the treatment of cardiovascular diseases. It is necessary to comprehensively elucidate the potential of natural flavonoids to combat PAH.

PURPOSE

To evaluate the potential of natural flavonoids to hinder or slow down the occurrence and development of PAH, and to identify promising drug discovery candidates.

METHODS

Literature was collected from PubMed, Science Direct, Web of science, CNKI databases and Google scholar. The search terms used included "pulmonary arterial hypertension", "pulmonary hypertension", "natural products", "natural flavonoids", "traditional chinese medicine", etc., and several combinations of these keywords.

RESULTS

The resources, structural characteristics, mechanisms, potential and prospect strategies of natural flavonoids for treating PAH were summarized. Natural flavonoids offer different solutions as possible treatments for PAH. These mechanisms may involve various pathways and molecular targets related to the pathogenesis of PAH, such as inflammation, oxidative stress, vascular remodeling, genetic, ion channels, cell proliferation and autophagy. In addition, prospect strategies of natural flavonoids for anti-PAH including structural modification and nanomaterial delivery systems have been explored. This review suggests that the potential of natural flavonoids as alternative therapeutic agents in the prevention and treatment of PAH holds promise for future research and clinical applications.

CONCLUSION

Despite displaying the enormous potential of flavonoids in PAH, some limitations need to be further explored. Firstly, using advanced drug discovery tools, including computer-aided design and high-throughput screening, to further investigate the safety, biological activity, and precise mechanism of action of flavonoids. Secondly, exploring the structural modifications of these compounds is expected to optimize their efficacy. Lastly, it is necessary to conduct well controlled clinical trials and a comprehensive evaluation of potential side effects to determine their effectiveness and safety.

Genetically determined gut microbiota associates with pulmonary arterial hypertension: a Mendelian randomization study

BACKGROUND

Emerging evidences have demonstrated that gut microbiota composition is associated with pulmonary arterial hypertension (PAH). However, the underlying causality between intestinal dysbiosis and PAH remains unresolved.

METHOD

An analysis using the two-sample Mendelian randomization (MR) approach was conducted to examine the potential causal relationship between gut microbiota and PAH. To assess exposure data, genetic variants associated with 196 bacterial traits were extracted from the MiBioGen consortium, which included a sample size of 18,340 individuals. As for the outcomes, summary statistics for PAH were obtained from the NHGRI-EBI GWAS Catalog, which conducted a meta-analysis of four independent studies comprising a total of 11,744 samples. Causal effects were estimated employing various methods, including inverse variance weighted (IVW), MR-Egger, weighted median, weight mode and simple mode, with sensitivity analyses also being implemented with Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and funnel plots.

RESULTS

Following false discovery rate (FDR) correction, the genetically predicted genus Eubacterium fissicatena group (odds ratio (OR) 1.471, 95% confidence interval (CI) 1.178-1.837, q = 0.076) exhibited a causal association with PAH. In addition, the genus LachnospiraceaeUCG004 (OR 1.511, 95% CI 1.048-2.177) and genus RuminococcaceaeUCG002 (OR 1.407, 95% CI 1.040-1.905) showed a suggestive increased risk of PAH, while genus Eubacterium eligens group (OR 0.563, 95% CI 0.344-0.922), genus Phascolarctobacterium (OR 0.692, 95% CI 0.487-0.982), genus Erysipelatoclostridium (OR 0.757, 95% CI 0.579-0.989) and genus T-yzzerella3 (OR 0.768, 95% CI 0.624-0.945) were found to have nominal protective effect against PAH.

CONCLUSION

The findings from our MR study have revealed a potential causal relationship between gut microbiota and PAH. Specifically, we have identified four types of gut microbiota that exhibit a protective effect on PAH, as well as three types that have a detrimental impact on PAH, thereby offering valuable insights for future mechanistic and clinical investigations in the field of PAH.

Promising dawn in the management of pulmonary hypertension: The mystery veil of gut microbiota

The gut microbiota is a complex community of microorganisms inhabiting the intestinal tract, which plays a vital role in human health. It is intricately involved in the metabolism, and it also affects diverse physiological processes. The gut-lung axis is a bidirectional pathway between the gastrointestinal tract and the lungs. Recent research has shown that the gut microbiome plays a crucial role in immune response regulation in the lungs and the development of lung diseases. In this review, we present the interrelated factors concerning gut microbiota and the associated metabolites in pulmonary hypertension (PH), a lethal disease characterized by elevated pulmonary vascular pressure and resistance. Our research team explored the role of gut-microbiota-derived metabolites in cardiovascular diseases and established the correlation between metabolites such as putrescine, succinate, trimethylamine N-oxide (TMAO), and N, N, N-trimethyl-5-aminovaleric acid with the diseases. Furthermore, we found that specific metabolites, such as TMAO and betaine, have significant clinical value in PH, suggesting their potential as biomarkers in disease management. In detailing the interplay between the gut microbiota, their metabolites, and PH, we underscored the potential therapeutic approaches modulating this microbiota. Ultimately, we endeavor to alleviate the substantial socioeconomic burden associated with this disease. This review presents a unique exploratory analysis of the link between gut microbiota and PH, intending to propel further investigations in the gut-lung axis.

Effect of Pulmonary Hypertension on Survival Outcomes in Patients With Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to determine the effect of pulmonary hypertension (PH) on survival in patients undergoing transcatheter aortic valve replacement (TAVR). The present study was conducted according to the guidelines of Preferred Reporting of Systematic Review and Meta-Analysis (PRISMA). We conducted a comprehensive search of electronic databases including PubMed/MEDLINE, Embase, Cochrane Library, and Web of Science from January 1, 2015, to March 10, 2024. Outcomes assessed in this meta-analysis included early and late all-cause mortality and cardiovascular mortality. Total 15 studies were integrated into the pooled analysis to assess the impact of PH on outcomes among patients undergoing TAVR, comprising a total sample size of 35,732 individuals. The pooled prevalence of PH stood at 52.57% (n=18,767). Predominantly, the studies were conducted in the United States (n=6), followed by Germany (n=3), with one study each from Japan, Italy, Switzerland, Brazil, Poland, and Australia. Pooled analysis showed that risk of short-term mortality was greater in patients with PH compared to patients without PH (risk ratio (RR): 1.46, 95% CI: 1.19 to 1.80). Risk of long-term mortality was greater in patients with PH (RR: 1.42, 95% CI: 1.29 to 1.55). Risk of cardiovascular mortality was also greater in patients with PH compared to patients without PH (RR: 1.66, 95% CI: 1.36 to 2.02). We advocate for further research to address gaps in understanding different types of PH and their impacts on mortality and cardiovascular outcomes.

A perfectly imperfect engine: Utilizing the digital twin paradigm in pulmonary hypertension

Pulmonary hypertension (PH) is a severe medical condition with a number of treatment options, the majority of which are introduced without consideration of the underlying mechanisms driving it within an individual and thus a lack of tailored approach to treatment. The one exception is a patient presenting with apparent pulmonary arterial hypertension and shown to have vaso-responsive disease, whose clinical course and prognosis is significantly improved by high dose calcium channel blockers. PH is however characterized by a relative abundance of available data from patient cohorts, ranging from molecular data characterizing gene and protein expression in different tissues to physiological data at the organ level and clinical information. Integrating available data with mechanistic information at the different scales into computational models suggests an approach to a more personalized treatment of the disease using model-based optimization of interventions for individual patients. That is, constructing digital twins of the disease, customized to a patient, promises to be a key technology for personalized medicine, with the aim of optimizing use of existing treatments and developing novel interventions, such as new drugs. This article presents a perspective on this approach in the context of a review of existing computational models for different aspects of the disease, and it lays out a roadmap for a path to realizing it.

The role of immune cells and inflammation in pulmonary hypertension: mechanisms and implications

Pulmonary hypertension (PH) is a malignant disease with progressive increase of pulmonary vascular pressure, which eventually leads to right heart failure. More and more evidences show that immune cells and inflammation play an important role in the occurrence and development of PH. In the context of pulmonary vascular diseases, immune cells migrate into the walls of the pulmonary vascular system. This leads to an increase in the levels of cytokines and chemokines in both the bloodstream and the surrounding tissues of the pulmonary vessels. As a result, new approaches such as immunotherapy and anti-inflammatory treatments are being considered as potential strategies to halt or potentially reverse the progression of PH. We reviewed the potential mechanisms of immune cells, cytokines and chemokines in PH development. The potential relationship of vascular cells or bone morphogenetic protein receptor 2 (BMPR2) in immune regulation was also expounded. The clinical application and future prospect of immunotherapy were further discussed.

Extrapulmonary manifestations of pulmonary arterial hypertension

INTRODUCTION

Extrapulmonary manifestations of pulmonary arterial hypertension (PAH) may play a critical pathobiological role and a deeper understanding will advance insight into mechanisms and novel therapeutic targets. This manuscript reviews our understanding of extrapulmonary manifestations of PAH.

AREAS COVERED

A group of experts was assembled and a complimentary PubMed search performed (October 2023 - March 2024). Inflammation is observed throughout the central nervous system and attempts at manipulation are an encouraging step toward novel therapeutics. Retinal vascular imaging holds promise as a noninvasive method of detecting early disease and monitoring treatment responses. PAH patients have gut flora alterations and dysbiosis likely plays a role in systemic inflammation. Despite inconsistent observations, the roles of obesity, insulin resistance and dysregulated metabolism may be illuminated by deep phenotyping of body composition. Skeletal muscle dysfunction is perpetuated by metabolic dysfunction, inflammation, and hypoperfusion, but exercise training shows benefit. Renal, hepatic, and bone marrow abnormalities are observed in PAH and may represent both end-organ damage and disease modifiers.

EXPERT OPINION

Insights into systemic manifestations of PAH will illuminate disease mechanisms and novel therapeutic targets. Additional study is needed to understand whether extrapulmonary manifestations are a cause or effect of PAH and how manipulation may affect outcomes.

Cancer Therapy-Associated Pulmonary Hypertension and Right Ventricular Dysfunction: Etiologies and Prognostic Implications

Advances in cancer therapies have improved oncologic outcomes but can potentially expose patients to risk of cardiovascular toxicity. While left ventricular (LV) dysfunction is a well-known cardiotoxicity of cancer therapy. Pulmonary hypertension (PH) and right ventricular (RV) dysfunction are seen with several cancer therapies, including alkylating agents, tyrosine kinase inhibitors (TKIs), and immunotherapy, and are associated with significant morbidity and mortality. Awareness and recognition of cancer therapy-associated PH and RV dysfunction is critical to identify underlying etiologies and institute the appropriate therapy. However, gaps exist in the current literature on the epidemiology of PH and RV dysfunction in cancer, underlying pathophysiology and optimal management strategies.