Effect of IL-17 on pulmonary artery smooth muscle cells and connective tissue disease-associated pulmonary arterial hypertension.

OBJECTIVE: To explore the role of interleukin (IL)-17 in connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) and to investigate its possible mechanism on pulmonary artery smooth muscle cells (PASMCs). METHODS: Enzyme-linked immunosorbent assay (ELISA) were used to compare levels of serum IL-17 in patients with CTD-PAH and healthy controls (HCs). After treatment for 3 months, the serum IL-17 levels were tested in CTD-PAH. ELISA and immunohistochemistry were used to compare levels of serum IL-17 and numbers of pulmonary artery IL-17+ cells, respectively, in a rat model of monocrotaline-induced PAH and untreated rats. Proliferation, migration, and inflammatory factors expression of PASMCs were assessed after stimulation with different concentrations of IL-17 for various time periods. Proteins in the mitogen-activated protein kinase (MAPK) pathway were examined by western blot. RESULTS: Levels of IL-17 were upregulated in patients with CTD-PAH compared to HCs. After 3 months of treatment, serum IL-17 levels were downregulated with pulmonary artery pressure amelioration. Moreover, serum IL-17 levels and numbers of IL-17+ cells infiltrating lung arterioles were increased in PAH model rats. IL-17 could dose- and time-dependently promote proliferation and migration of PASMCs as well as time-dependently induce IL-6 and intercellular cell adhesion molecule-1 (ICAM-1) expression. The levels of MKK6 increased after IL-17 treatment. Inhibition of MAPK decreased proliferation of PASMCs. CONCLUSION: Levels of IL-17 may increase in CTD-PAH, and IL-17 promotes proliferation, migration, and secretion of IL-6 and ICAM in PASMCs, respectively, which likely involves the p-38 MAPK pathway.

Canagliflozin inhibits PASMCs proliferation via regulating SGLT1/AMPK signaling and attenuates artery remodeling in MCT-induced pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) was a devastating disease characterized by artery remodeling, ultimately resulting in right heart failure. The aim of this study was to investigate the effects of canagliflozin (CANA), a sodium-glucose cotransporter 2 inhibitor (SGLT2i) with mild SGLT1 inhibitory effects, on rats with PAH, as well as its direct impact on pulmonary arterial smooth muscle cells (PASMCs). PAH rats were induced by injection of monocrotaline (MCT) (40 mg/kg), followed by four weeks of treatment with CANA (30 mg/kg/day) or saline alone. Pulmonary artery and right ventricular (RV) remodeling and dysfunction in PAH were alleviated with CANA, as assessed by echocardiography. Hemodynamic parameters and structural of pulmonary arteriole, including vascular wall thickness and wall area, were reduced by CANA. RV hypertrophy index, cardiomyocyte hypertrophy, and fibrosis were decreased with CANA treatment. PASMCs proliferation was inhibited by CANA under stimulation by platelet-derived growth factor (PDGF)-BB or hypoxia. Activation of AMP kinase (AMPK) was induced by CANA treatment in cultured PASMCs in a time- and concentration-dependent manner. These effects of CANA were attenuated when treatment with compound C, an AMPK inhibitor. Abundant expression of SGLT1 was observed in PASMCs and pulmonary arteries, while SGLT2 expression was undetectable. SGLT1 increased in response to PDGF-BB or hypoxia stimulation, while PASMCs proliferation was inhibited and beneficial effects of CANA were counteracted by knockdown of SGLT1. Our research demonstrated for the first time that CANA inhibited the proliferation of PASMCs by regulating SGLT1/AMPK signaling and thus exerted an anti-proliferative effect on MCT-induced PAH.

Spermidine attenuates monocrotaline-induced pulmonary arterial hypertension in rats by inhibiting purine metabolism and polyamine synthesis-associated vascular remodeling.

Ensuring the homeostatic integrity of pulmonary artery endothelial cells (PAECs) is essential for combatting pulmonary arterial hypertension (PAH), as it equips the cells to withstand microenvironmental challenges. Spermidine (SPD), a potent facilitator of autophagy, has been identified as a significant contributor to PAECs function and survival. Despite SPD's observed benefits, a comprehensive understanding of its protective mechanisms has remained elusive. Through an integrated approach combining metabolomics and molecular biology, this study uncovers the molecular pathways employed by SPD in mitigating PAH induced by monocrotaline (MCT) in a Sprague-Dawley rat model. The study demonstrates that SPD administration (5 mg/kg/day) significantly corrects right ventricular impairment and pathological changes in pulmonary tissues following MCT exposure (60 mg/kg). Metabolomic profiling identified a purine metabolism disorder in MCT-treated rats, which SPD effectively normalized, conferring a protective effect against PAH progression. Subsequent in vitro analysis showed that SPD (0.8 mM) reduces oxidative stress and apoptosis in PAECs challenged with Dehydromonocrotaline (MCTP, 50 µM), likely by downregulating purine nucleoside phosphorylase (PNP) and modulating polyamine biosynthesis through alterations in S-adenosylmethionine decarboxylase (AMD1) expression and the subsequent production of decarboxylated S-adenosylmethionine (dcSAM). These findings advocate SPD's dual inhibitory effect on PNP and AMD1 as a novel strategy to conserve cellular ATP and alleviate oxidative injuries, thus providing a foundation for SPD's potential therapeutic application in PAH treatment.

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

Purpose: The underlying causes of pulmonary arterial hypertension (PAH) often remain obscure. Addressing PAH with effective treatments presents a formidable challenge. Studies have shown that Hydroxysafflor yellow A (HSYA) has a potential role in PAH, While the mechanism underlies its protective role is still unclear. The study was conducted to investigate the potential mechanisms of the protective effects of HSYA. Methods: Using databases such as PharmMapper and GeneCards, we identified active components of HSYA and associated PAH targets, pinpointed intersecting genes, and constructed a protein-protein interaction (PPI) network. Core targets were singled out using Cytoscape for the development of a model illustrating drug-component-target-disease interactions. Intersection targets underwent analysis for Gene Ontology (GO) functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Selected components were then modeled for target interaction using Autodock and Pymol. In vivo validation in a monocrotaline-induced PAH (MCT-PAH) animal model was utilized to substantiate the predictions made by network pharmacology. Results: We associated HSYA with 113 targets, and PAH with 1737 targets, identifying 34 mutual targets for treatment by HSYA. HSYA predominantly affects 9 core targets. Molecular docking unveiled hydrogen bond interactions between HSYA and several PAH-related proteins such as ANXA5, EGFR, SRC, PPARG, PGR, and ESR1. Conclusion: Utilizing network pharmacology and molecular docking approaches, we investigated potential targets and relevant human disease pathways implicating HSYA in PAH therapy, such as the chemical carcinogenesis receptor activation pathway and the cancer pathway. Our findings were corroborated by the efficacious use of HSYA in an MCT-induced rat PAH model, confirming its therapeutic potential.

Effect of Benidipine Alone and in Combination With Bosentan and Sildenafil in Amelioration of Pulmonary Arterial Hypertension in Experimental Model in Rats.

ABSTRACT: Pulmonary arterial hypertension (PAH) is a persistent condition affecting the pulmonary arteries' endothelium. Benidipine, a calcium channel blocker, possesses vasodilatory, anti-inflammatory activity, reduces oxidative stress, and inhibits the activity of Transforming growth factor-ß (TGF-ß) and α-smooth muscle actin (α-SMA). The present study was designed to investigate the effect of benidipine alone and in combination with bosentan and sildenafil on monocrotaline (MCT)-induced pulmonary hypertension in a rat model. PAH was induced by a single-dose administration of MCT in rats. Animals were randomized into different groups and treated with benidipine alone and in combination with bosentan or sildenafil. Various parameters such as hemodynamic parameters, Fulton's index and oxidative stress parameters were performed. Additionally, histopathology of lung and right ventricular of heart tissue, immunohistochemistry, expression of α-SMA, endothelial nitric oxide synthase (eNOS), TGF-ß, and RT-PCR, and an in vitro study using human umbilical vein endothelial cells (HUVECs) was also carried out. Treatment of benidipine and its combination exhibited better prevention in the elevated right ventricular systolic pressure, right ventricular hypertrophy, rise in oxidative stress, and increase in expression of α-SMA and TGF-ß receptor 1 compared with MCT control group rats. In HUVECs, the expression of α-SMA was increased, whereas that of eNOS decreased after TGF-ß exposure and was substantially reversed after pretreatment with benidipine. We concluded that benidipine and its combination with bosentan and sildenafil exhibit beneficial effects in MCT-induced PAH through the eNOS/TGF-ß/α-SMA signaling pathway.

In vivo pharmacokinetic study of vanillic acid in monocrotaline-induced pulmonary arterial hypertension rats and its tissue distribution.

Vanillic acid (VA) is a bioactive chemical present in many food plants and fruits. It has been shown to have a protective effect on pulmonary tissues in monocrotaline-induced pulmonary arterial hypertension, as well as an intervention effect on right ventricular remodeling. The purpose of this study was to develop and test a reliable method for assessing VA utilizing ultra-performance liquid chromatography-high resolution mass spectrometry using caffeic acid as the internal standard. Across diverse substrates, the correlation coefficient for VA ranged from 0.9992 to 0.9995. The method's intraday precision was <13.53% (RSD), and its accuracy (RE) ranged from -9.88 to 4.35%. The precision across days was <13.69% (RSD), while the accuracy ranged from 2.16 to 10.94% (RE). The extraction recoveries ranged from 80.30 to 118.81%, with a lower limit of quantification of 20 ng/mL. The approach was successfully applied to pharmacokinetic and tissue distribution studies of VA in rat plasma after gavage administration, and the pharmacokinetic parameters of VA in the plasma of the monocrotaline-induced pulmonary arterial hypertension were significantly different from those of the control group.

Methamphetamine-associated pulmonary arterial hypertension: data from the national biological sample and data repository for pulmonary arterial hypertension (PAH Biobank).

OBJECTIVE: This study compares the clinical and haemodynamic severity of methamphetamine-associated pulmonary arterial hypertension (MA-PAH) with idiopathic pulmonary arterial hypertension (IPAH) and connective tissue-associated pulmonary arterial hypertension (CTD-PAH). It also examines sex differences in clinical and physiological parameters among those with MA-PAH. DESIGN: This is a cross-sectional study using clinically derived data from the National Biological Sample and Data Repository for Pulmonary Arterial Hypertension (PAH biobank), a US-based registry, to compare clinical and physiological characteristics between males and females with MA-PAH. POPULATION: The analysis included 1830 patients enrolled in the PAH biobank, with a diagnosis of MA-PAH (n=42), IPAH (n=1073), or CTD-PAH (n=715). MAIN OUTCOME MEASURES: The study assessed and compared the clinical and haemodynamic parameters of patients with MA-PAH, IPAH and CTD-PAH. RESULTS: Among the patients analysed, 42 had MA-PAH, with 69.1% being female. There were no statistically significant differences in functional class among patients with MA-PAH, IPAH and CTD-PAH. The per cent predicted 6-min walk distance (6MWD) was comparable between the three groups. Patients with MA-PAH had similar mean pulmonary artery pressure and pulmonary vascular resistance to patients with IPAH but higher compared with patients with CTD-PAH. Male patients with MA-PAH exhibited a worse functional class and lower per cent predicted 6MWD, but no significant differences in haemodynamic findings were observed between the sexes. CONCLUSION: There were no differences in haemodynamic between MA-PAH and IPAH but we found that MA-PAH differed from CTD-PAH. The study did not find evidence of sex differences in MA-PAH. Further research is necessary to identify risk factors and underlying mechanisms of MA-PAH, particularly considering the increasing prevalence of methamphetamine use. Such investigations will contribute to the development of effective prevention and treatment strategies for this condition.

The novel roles of YULINK in the migration, proliferation and glycolysis of pulmonary arterial smooth muscle cells: implications for pulmonary arterial hypertension.

BACKGROUND: Abnormal remodeling of the pulmonary vasculature, characterized by the proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) along with dysregulated glycolysis, is a pathognomonic feature of pulmonary arterial hypertension (PAH). YULINK (MIOS, Entrez Gene: 54468), a newly identified gene, has been recently shown to possess pleiotropic physiologic functions. This study aims to determine novel roles of YULINK in the regulation of PAH-related pathogenesis, including PASMC migration, proliferation and glycolysis. RESULTS: Our results utilized two PAH-related cell models: PASMCs treated with platelet-derived growth factor (PDGF) and PASMCs harvested from monocrotaline (MCT)-induced PAH rats (PAH-PASMCs). YULINK modulation, either by knockdown or overexpression, was found to influence PASMC migration and proliferation in both models. Additionally, YULINK was implicated in glycolytic processes, impacting glucose uptake, glucose transporter 1 (GLUT1) expression, hexokinase II (HK-2) expression, and pyruvate production in PASMCs. Notably, YULINK and GLUT1 were observed to colocalize on PASMC membranes under PAH-related pathogenic conditions. Indeed, increased YULINK expression was also detected in the pulmonary artery of human PAH specimen. Furthermore, YULINK inhibition led to the suppression of platelet-derived growth factor receptor (PDGFR) and the phosphorylation of focal adhesion kinase (FAK), phosphoinositide 3-kinase (PI3K), and protein kinase B (AKT) in both cell models. These findings suggest that the effects of YULINK are potentially mediated through the PI3K-AKT signaling pathway. CONCLUSIONS: Our findings indicate that YULINK appears to play a crucial role in the migration, proliferation, and glycolysis in PASMCs and therefore positioning it as a novel promising therapeutic target for PAH.

Pinocembrin attenuates susceptibility to atrial fibrillation in rats with pulmonary arterial hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a disease characterized by pulmonary vascular remodeling that triggers fibrosis and excessive myocardium apoptosis, ultimately facilitating atrial fibrillation (AF). In various rat models, Pinocembrin has anti-fibrotic and anti-apoptotic effects, reducing arrhythmia vulnerability. However, whether pinocembrin alleviates to AF in a PAH model remains unclear. The experiment aims to investigate how pinocembrin affects AF susceptibility in PAH rats and the possible mechanisms involved. METHODS: The PAH model was induced by monocrotaline (MCT; i. p. 60 mg/kg). Concurrently, rats received pinocembrin (i.p.50 mg/kg) or saline. Hemodynamics parameters, electrocardiogram parameters, lung H.E. staining, atrial electrophysiological parameters, histology, Western blot, and TUNEL assay were detected. RESULTS: Compared to the control rats, MCT-induced PAH rats possessed prominently enhancive mPAP (mean pulmonary artery pressure), pulmonary vascular remodeling, AF inducibility, HRV, right atrial myocardial fibrosis, apoptosis, atrial ERP, APD, and P-wave duration. Additionally, there were lowered protein levels of Cav1.2, Kv4.2, Kv4.3, and connexin 40 (CX40) in the MCT group in right atrial tissue. However, pinocembrin reversed the above pathologies and alleviated the activity of the Rho A/ROCKs signaling pathway, including the expression of Rho A, ROCK1, ROCK2, and its downstream MYPT-1, LIMK2, BCL-2, BAX, cleaved-caspase3 in right atrial and HL-1 cells. CONCLUSION: Present data exhibited pinocembrin attenuated atrial electrical, ion-channel, and autonomic remodeling, diminished myocardial fibrosis and apoptosis levels, thereby reducing susceptibility to AF in the MCT-induced PAH rats. Furthermore, we found that pinocembrin exerted inhibitory action on the Rho A/ROCK signaling pathway, which may be potentially associated with its anti-AF effects.

Safety and effectiveness of ambrisentan in real clinical practice in pulmonary arterial hypertension: Results from the Korean post-marketing surveillance.

PURPOSE: This regulatory post-marketing surveillance (PMS) was organized to identify the safety and effectiveness of ambrisentan in the Korean population. METHOD: This was an open-label, multi-center PMS conducted from 31 institutions in Korea for 6 years from August 2015 to 2021, to evaluate the use of ambrisentan for the treatment of pulmonary arterial hypertension (PAH). Inclusion criteria are Korean subjects with the World Health Organization functional classification (WHO Fc) II or III PAH who are new users or repeated users with ambrisentan (Volibris®) Tablet 5 or 10 mg per day (age >18 years old). RESULTS: A total of 293 cases were analyzed. The overall incidence of adverse events (AE) was 52.22% and adverse drug reactions (ADR) was 10.92%. Severe AEs occurred in 20.82% of patients. However, only 2 subjects (0.68%) reported serious ADR. The difference in AE incidence was statistically significant for concomitant medications other than PAH medications in the safety analysis and the new users (p = 0.0041 and p = 0.0299, respectively) and elderly population in the repeated users (p = 0.0319). Among the long-term 223 subjects, the WHO Fc II and III were 41.26% and 58.74% before ambrisentan, and changed after treatment to 3.09%, 66.05%, and 30.86% for Fc I/II/III, respectively. 217 of 249 subjects (87.15%) considered their symptoms to have 'improved' after the last administration. CONCLUSION: In real-world practice, ambrisentan demonstrated tolerable safety and favorable effectiveness in PAH patients in Korea. Age and concomitant drug use can affect the occurrence of AE.

Development of novel bosentan analogues as endothelin receptor antagonists for pulmonary arterial hypertension.

Since decades, bosentan has been in use for the treatment of pulmonary arterial hypertension (PAH). However, chronic exposure to bosentan leads to the development of resistance, tolerance, and serious adverse effects that have restricted its usage in clinical practices. To surmount these limitations, some new bosentan derivatives have been synthesized and evaluated for their therapeutic efficacy in PAH. Molecular docking analyses of all the synthesized derivatives were carried out using the endothelin (ET) receptor. In addition, the inhibitory ability of synthesized derivatives was determined in in vitro assay employing an ET-1 human ELISA kit. Among the synthesized derivatives, three derivatives namely 17d, 16j, and 16h with higher docking scores and lower IC50 values were selected for determination of the magnitude of the binding force between the derivative and ET receptor using molecular dynamics (MD) simulations study. Further, these derivatives were subjected to in vivo studies using monocrotaline (MCT) induced PAH in rat model. Results of in vivo studies inferred that the derivatives exhibit impressive ability to reduce PAH. Besides, its protective role was also evidenced in hemodynamic and right ventricular hypertrophy analyses, histological analysis, cardiac biomarkers, hypoxia-inducible factor 1 alpha (HIF1α) levels, and biochemical studies. Furthermore, gene quantification by quantitative RT-PCR and Western blot analysis was also performed to examine its effect on the expression of key proteins in PAH. Notably, amongst three, derivative 16h exhibited the most encouraging results in molecular docking analysis, in vitro, in vivo, histopathological, biochemical, protein expression, and MD studies. Besides, derivative 16h also showed impressive pharmacokinetic features in ADMET analysis. In conclusion, derivative 16 h could act as a reliable ET receptor antagonist and requires further exploration to attain its therapeutic utility in PAH management.

Nobiletin attenuates monocrotaline-induced pulmonary arterial hypertension through PI3K/Akt/STAT3 pathway.

OBJECTIVES: Nobiletin is a flavonoid found in the peel of Citrus sinensis (oranges). The purpose of this study is to investigate whether Nobiletin can alleviate the monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and explore the underlying mechanisms. METHODS: The PAH rat model was replicated by subcutaneous injection of MCT. Nobiletin (1, 5 and 10 mg/kg) was administered by gavage from day 1 to day 21. After 21 days of MCT injection, the mean pulmonary artery pressure, pulmonary vascular resistance, Fulton Index, pulmonary artery remodelling, blood routine parameters, liver and kidney functions was measured. The level of inflammatory cytokines and PI3K/Akt/STAT3 were detected by qPCR, ELISA and western blot, the proliferation of pulmonary artery smooth muscle cells (PASMCs) was evaluated by CCK-8. KEY FINDINGS: Nobiletin (10 mg/kg) inhibited the MCT-induced increase in mean pulmonary artery pressure and pulmonary vascular resistance, right ventricular hypertrophy and pulmonary artery remodelling in rats. Nobiletin decreased the levels of inflammatory cytokines and phosphorylation level of PI3K/Akt/STAT3 in lungs of MCT-treated rats. Nobiletin inhibited the proliferation and lowered the inflammatory cytokines level induced by PDGF-BB in PASMCs. CONCLUSION: Nobiletin attenuates MCT-induced PAH, and the potential mechanism is to inhibit inflammation through PI3K/Akt/STAT3 pathway.

Comparative evaluation of costs and healthcare resource utilization of oral selexipag versus inhaled treprostinil or oral treprostinil in patients with pulmonary arterial hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH), a rare vasculopathy progressively leading to right heart failure and death, is associated with considerable economic burden. Oral prostacyclin pathway agents (PPAs) like selexipag and treprostinil address an underlying PAH pathway, yet are often under-utilized. Data on head-to-head cost comparison of various PPAs is lacking. METHODS: In this retrospective study using a large health claims database, we compared the per-patient-per-year (PPPY) costs and healthcare resource utilization (HRU) among PAH patients taking either oral selexipag, inhaled treprostinil or oral treprostinil in the United States between July 2015 and March 2020. Patients with ≥1 prescription for one of the drugs of interest, ≥1 in-patient pulmonary hypertension (PH) diagnosis, or ≥ 2 outpatient PH diagnoses were included in this study. Baseline differences between the three groups were adjusted using an inverse probability of treatment weighting approach. 411 patients were selected for the final study cohorts. RESULTS: All-cause hospitalization costs were highest for oral treprostinil ($39,983) compared to oral selexipag ($20,635) and inhaled treprostinil ($16,548; p = .037). Total PAH-related medical costs were 40% lower for patients on oral selexipag compared to patients on oral and inhaled treprostinil ($24,351 vs. $40,398 and $40,339, respectively; p = .006). PAH-related outpatient visits were lowest for patients on oral selexipag (14 PPPY visits) compared to oral treprostinil (16 PPPY visits) and inhaled treprostinil (22 PPPY visits; p = .001). CONCLUSIONS: Compared to oral and inhaled treprostinil, oral selexipag may incur lower medical costs and reduce PAH related outpatient visits for patients with PAH.

Shikonin improves pulmonary vascular remodeling in monocrotaline­induced pulmonary arterial hypertension via regulation of PKM2.

Pulmonary arterial hypertension (PAH), a fatal disease with an insidious onset and rapid progression, shows characteristics such as increases in pulmonary circulatory resistance and pulmonary arterial pressure, and progressive right heart failure. Shikonin can reduce right ventricular systolic pressure in chronically hypoxic mice. However, the mechanisms underlying the protective effect of shikonin against PAH pathogenesis have only been sporadically identified. The present study evaluated whether inhibiting the expression of pyruvate kinase M2 (PKM2) contributed to the improvement of pulmonary vascular remodeling in PAH rats induced by monocrotaline (MCT) treatment. Hemodynamic parameters were assessed using echocardiography and right ventricular catheterization. Right ventricular hypertrophy index analysis and hematoxylin and eosin staining were used to evaluate the degree of pulmonary vascular and right heart remodeling. Moreover, PKM2, p­PKM2, ERK, p­ERK, glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA) protein expression levels were semi­quantified using western blotting. The expression and distribution of PKM2 were assessed using immunofluorescence microscopy. The present study demonstrated that MCT treatment caused pulmonary arterial hypertension and pulmonary vascular remodeling in experimental rats. Shikonin improved hemodynamics and pulmonary vascular remodeling in MCT­induced PAH rats, decreased aerobic glycolysis and downregulated PKM2, p­PKM2, p­ERK, GLUT 1 and LDHA protein expression levels. Shikonin improved experimental pulmonary arterial hypertension hemodynamics and pulmonary vascular remodeling at least partly through the inhibition of PKM2 and the resultant suppression of aerobic glycolysis. These results provide a novel understanding of possible new treatment targets for PAH.

Tolerability, safety and survival in patients with severe pulmonary arterial hypertension treated with intravenous epoprostenol (Veletri®): a prospective, 6-months, open label, observational, non-interventional study.

BACKGROUND: Epoprostenol AS (Veletri®), a thermostable epoprostenol formulation, provides better drug stability and improved clinical use compared to previous epoprostenol formulations. This study aims to expand clinical experience in the use of Veletri®, especially regarding tolerability, safety and survival. METHODS: Pulmonary arterial hypertension (PAH) patients at high risk despite pretreatment with at least double oral combination therapy and with clinical indication for epoprostenol (Veletri®) treatment were consecutively included in this prospective, open label, observational, non-interventional study. Clinical data were assessed at baseline, after 3 and 6 months. Adverse events (AEs) and serious adverse events (SAEs) were documented. Survival from initiation of Veletri® was assessed at last patient out. RESULTS: Fifteen patients (60 ± 13.7 years, WHO functional class III (n = 10) or IV (n = 5), severely impaired right ventricular function, mean pulmonary arterial pressure 54.8 ± 8.9 mmHg, mean pulmonary vascular resistance 4.4 ± 0.7 (median 3.8) Wood Units) were enrolled and treated with a mean dosage of 7.9 ± 3.9 (median 7.5) ng/kg/min. Eleven patients completed the study (treatment withdrawal n = 1, death n = 3). After a mean follow-up of 19.1 ± 13.5 (median 18.0) months, seven patients died and three were listed for lung transplantation. Seven AEs (nausea n = 3, diarrhea n = 1, flushing n = 2, headaches n = 1) and three SAEs (catheter infection n = 2, catheter occlusion n = 1) were related to Veletri®. The 1- and 2-year survival rates were 73.3% and 52.4%, respectively. CONCLUSIONS: The study showed that safety and tolerability of epoprostenol AS (Veletri®) was comparable to previous prostacyclin formulations and was feasible for most patients. The maximum tolerable dosage was lower than dosages reported in the literature. In future applications/trials the up-titration process should be pushing for higher dosages of epoprostenol in the occurrence of side effects, as the achievement of a high and effective dosage is crucial for the clinical benefit of the patients. Survival was as expected in these prevalent severely impaired patients. Trial registration The study was registered in the EUPAS registry (EUPAS32492).

Comparative transcription profiling of mRNA and lncRNA in pulmonary arterial hypertension after C75 treatment.

OBJECTIVES: To investigate mRNA and long non-coding RNA (lncRNA) expression profiles in monocrotaline (MCT)- mice. MATERIALS AND METHODS: Lung tissues (Control-Vehicle, MCT-Vehicle, and MCT-C75) were examined by high-throughput sequencing (HTS). Aberrantly expressed mRNAs and lncRNAs were analyzed by bioinformatics. Cell proliferation and cell cycle analysis were performed to detect the potential protective effects of C75, an inhibitor of fatty acid synthase. The signaling pathways associated with inflammatory responses were verified by real time-PCR. RESULTS: RNA sequencing data reveals 285 differentially expressed genes (DEGs) and 147 lncRNAs in the MCT-Vehicle group compared to the control. After five-week of C75 treatment, 514 DEGs and 84 lncRNAs are aberrant compared to the MCT-Vehicle group. Analysis of DEGs and lncRNA target genes reveals that they were enriched in pathways related to cell cycle, cell division, and vascular smooth muscle contraction that contributes to the PAH pathological process. Subsequently, the expression of eight DEGs and three lncRNAs is verified using RT-PCR. Differentially expressed lncRNAs (ENSMUSG00000110393.2, Gm38850, ENSMUSG00000100465.1, ENSMUSG00000110399.1) may associate in PAH pathogenesis as suggested by co-expression network analysis. C75 can protect against MCT-induced PAH through its anti-inflammatory and anti-proliferation. CONCLUSIONS: These DEGs and lncRNAs can be considered as novel candidate regulators of PAH pathogenesis. We propose that C75 treatment can partially reverse PAH pathogenesis through modulating cell cycle, cell proliferation, and anti-inflammatory.

Curcumol suppresses endothelial-to-mesenchymal transition via inhibiting the AKT/GSK3ß signaling pathway and alleviates pulmonary arterial hypertension in rats.

Endothelial dysfunction is essential in pulmonary arterial hypertension (PAH) pathogenesis and is considered to be a therapeutic target of PAH. Curcumol is a bioactive sesquiterpenoid with pharmacological properties including restoring endothelial cells damage. This study aimed to evaluate the effect of curcumol on PAH rats and investigate its possible mechanisms. PAH was induced by subcutaneous injection of 60 mg/kg monocrotaline (MCT) in male Sprague Dawley rats. Curcumol (12.5, 25, and 50 mg/kg/day) were administered by intragastric administration for 3 weeks. The results demonstrated that curcumol dose-dependently alleviated MCT-induced right ventricular hypertrophy and pulmonary arterial wall thickness. In addition, endothelial-to-mesenchymal transition (EndMT) in the pulmonary arteries of MCT-challenged rats was inhibited after curcumol treatment, as evidenced by the restored expressions of endothelial and myofibroblast markers. The possible pharmacological mechanisms of curcumol were analyzed using network pharmacology. After screening the common therapeutic targets of PAH and curcumol by searching related databases and comparison, pathway enrichment was performed and AKT/GSK3ß was screened out as a possible signaling pathway which was relevant to the therapeutic mechanism of curcumol on PAH. Western blot analysis verified this in lung tissues. Moreover, combination of TNF-α, TGF-ß1 and IL-1ß-induced EndMT in primary rat pulmonary arterial endothelial cells were blocked by curcumol, and this effect was resembled by PI3K/AKT inhibitor LY294002. Above all, our study suggested that curcumol inhibited EndMT via inhibiting the AKT/GSK3ß signaling pathway, which may contribute to its alleviated effect on PAH. Curcumol may be developed as a therapeutic for PAH in the future.

Obstructive sleep apnea-increased DEC1 regulates systemic inflammation and oxidative stress that promotes development of pulmonary arterial hypertension.

Obstructive sleep apnea (OSA), characterized by chronic intermittent hypoxia (CIH), is a common risk factor for pulmonary arterial hypertension (PAH). As a hypoxia-induced transcription factor, differentially expressed in chondrocytes (DEC1) negatively regulates the transcription of peroxisome proliferative activated receptor-γ (PPARγ), a recognized protective factor of PAH. However, whether and how DEC1 is associated with PAH pathogenesis remains unclear. In the present study, we found that DEC1 was increased in lungs and pulmonary arterial smooth muscle cells (PASMCs) of rat models of OSA-associated PAH. Oxidative indicators and inflammatory cytokines were also elevated in the blood of the rats. Similarly, hypoxia-treated PASMCs displayed enhanced DEC1 expression and reduced PPARγ expression in vitro. Functionally, DEC1 overexpression exacerbated reactive oxygen species (ROS) production and the expression of pro-inflammatory cytokines (such as TNFα, IL-1ß, IL-6, and MCP-1) in PASMCs. Conversely, shRNA knockdown of Dec1 increased PPARγ expression but attenuated hypoxia-induced oxidative stress and inflammatory responses in PASMCs. Additionally, DEC1 overexpression promoted PASMC proliferation, which was drastically attenuated by a PPARγ agonist rosiglitazone. Collectively, these results suggest that hypoxia-induced DEC1 inhibits PPARγ, and that this is a predominant mechanism underpinning oxidative stress and inflammatory responses in PASMCs during PAH. DEC1 could be used as a potential target to treat PAH.

Pediatric Population Pharmacokinetic Modeling and Exposure-Response Analysis of Ambrisentan in Pulmonary Arterial Hypertension and Comparison With Adult Data.

This study aimed to develop a population pharmacokinetic (PK) model of ambrisentan in pediatric patients (8 to <18 years) with pulmonary arterial hypertension (PAH) and compare pediatric ambrisentan systemic exposure with previously reported adult data. Association of ambrisentan exposure with efficacy (6-minute walking distance) and safety (adverse events) were exploratory analyses. A population PK model was developed using pediatric PK data. Steady-state systemic exposure metrics were estimated for the pediatric population and compared with previously reported data in adult patients with PAH and healthy subjects. No covariates had a significant effect on PK parameters; therefore, the final covariate model was the same as the base model. The pediatric population PK model was a 2-compartment model including the effect of body weight (allometric scaling), first-order absorption and elimination, and absorption lag time. Steady-state ambrisentan exposure was similar between the pediatric and adult population when accounting for body weight differences. Geometric mean area under the concentration-time curve at steady state in pediatric patients receiving ambrisentan low dose was 3% lower than in the adult population (and similar in both populations receiving high dose). Geometric mean maximum plasma concentration at steady state in pediatric patients receiving low and high doses was 11% and 18% higher, respectively, than in the adult population. There was no apparent association in the pediatric or adult population between ambrisentan exposure and change in 6-minute walking distance or incidence of ambrisentan-related adverse events in pediatric patients. The similar ambrisentan exposure and exposure-response profiles observed in pediatric and adult populations with PAH suggests appropriateness of body-weight-based dosing in the pediatric population with PAH.

A study of the efficacy of sacubitril/valsartan plus dapagliflozin combination treatment in pulmonary arterial hypertension due to left heart disease.

OBJECTIVE: To determine the efficacy of sacubitril/valsartan plus dapagliflozin in the treatment of patients with pulmonary arterial hypertension (PAH) due to left heart disease and to explore new treatment regimen for PAH due to left heart disease. METHODS: This study is a randomized controlled trial (RCT) study of 120 patients with PAH due to left heart disease admitted to the cardiovascular department of our hospital from Dec. 2019 to Dec. 2021. The patients were randomized 1:1 to the study group and control group. All patients were given baseline treatments targeting left heart disease and symptoms of PAH. In addition to the baseline treatments, patients in the control group were given sacubitril/valsartan tablets, while patients in the study group were given sacubitril/valsartan tablets plus dapagliflozin tablets. After 6 months of treatment, parameters including left heart function and exercise tolerance, Hemodynamics (left ventricular end systolic diameter [LVSED], left ventricular end diastolic diameter [LVEDD], left ventricular ejection fraction [LVEF], 6 min walk distance (6MWD), mean pulmonary artery pressure (mPAP) and pulmonary artery systolic pressure (PASP)), vascular endothelial function (plasma endothelin (ET) -1 and nitric oxide [NO]), heart failure markers (plasma N-terminal pro-brain natriuretic peptide (NT-proBNP)], inflammatory factors (serum C reactive protein [CRP], interleukin (IL)-6, and tumor necrosis factor (TNF)-α], and adverse drug reactions (ADRs) were assessed in both groups. RESULTS: Both groups had reduced LVESD and LVEDD, increased LVEF, and extended 6MWD after 6 months of treatment. The improvements in these parameters were significantly greater in the study group than in the control group (all P < 0.05). In addition, both the mPAP and PASP showed a decrease, and the mPAP and PASP in the study group were lower than those in the control group (p<0.05). Furthermore, both groups had decreased plasma ET-1 and NT-proBNP but increased plasma NO after 6 months of treatment. The improvements in these parameters were significantly greater in the study group than in the control group (all P < 0.05). Serum CRP, IL-6 and TNF-α levels were decreased in both groups after 6 months of treatment, and were significantly lower in the study group than in the control group (all P < 0.05). There was no significant difference in the overall incidence of ADRs between the two groups (P > 0.05). CONCLUSION: Sacubitril/valsartan plus dapagliflozin in the treatment with PAH due to left heart disease can improve left heart function of patients by improving vascular endothelial functions and alleviating inflammation, which helps to reduce the PAH process. Therefore, this combination treatment is safe and effective in PAH due to left heart disease.