Identification of Noncoding Functional Regulatory Variants of STIM1 Gene in Idiopathic Pulmonary Arterial Hypertension.

BACKGROUND: STIM1 (stromal interaction molecule 1) regulates store-operated calcium entry and is involved in pulmonary artery vasoconstriction and pulmonary artery smooth muscle cell proliferation, leading to pulmonary arterial hypertension (PAH). METHODS: Bioinformatics analysis and a 2-stage matched case-control study were conducted to screen for noncoding variants that may potentially affect STIM1 transcriptional regulation in 242 patients with idiopathic PAH and 414 healthy controls. Luciferase reporter assay, real-time quantitative polymerase chain reaction, western blot, 5-ethynyl-2'-deoxyuridine (EdU) assay, and intracellular Ca2+ measurement were performed to study the mechanistic roles of those STIM1 noncoding variants in PAH. RESULTS: Five noncoding variants (rs3794050, rs7934581, rs3750996, rs1561876, and rs3750994) were identified and genotyped using Sanger sequencing. Rs3794050, rs7934581, and rs1561876 were associated with idiopathic PAH (recessive model, all P<0.05). Bioinformatics analysis showed that these 3 noncoding variants possibly affect the enhancer function of STIM1 or the microRNA (miRNA) binding to STIM1. Functional validation performed in HEK293 and pulmonary artery smooth muscle cells demonstrated that the noncoding variant rs1561876-G (STIM1 mutant) had significantly stronger transcriptional activity than the wild-type counterpart, rs1561876-A, by affecting the transcriptional regulatory function of both hsa-miRNA-3140-5p and hsa-miRNA-4766-5p. rs1561876-G enhanced intracellular Ca2+ signaling in human pulmonary artery smooth muscle cells secondary to calcium-sensing receptor activation and promoted proliferation of pulmonary artery smooth muscle cells under both normoxia and hypoxia conditions, suggesting a possible contribution to PAH development. CONCLUSIONS: The potential clinical implications of the 3 noncoding variants of STIM1, rs3794050, rs7934581, and rs1561876, are 2-fold, as they may help predict the risk and prognosis of idiopathic PAH and guide investigations on novel therapeutic pathway(s).

Development and external validation of a nomogram for predicting short-term prognosis in patients with acute pulmonary embolism.

BACKGROUND: Accurate assessment and timely intervention play a crucial role in ameliorating poor short-term prognosis of acute pulmonary embolism (APE) patients. The currently employed scoring models exhibit a degree of complexity, and some models may not comprehensively incorporate relevant indicators, thereby imposing limitations on the evaluative efficacy. Our study aimed to construct and externally validate a nomogram that predicts 30-day all-cause mortality risk in APE patients. METHODS: Clinical data from APE patients in Intensive Care-IV database was included as a training cohort. Additionally, we utilized our hospital's APE database as an external validation cohort. The nomogram was developed, and its predictive ability was evaluated using receiver operating characteristic (ROC) curves, calibration plots and decision curve analysis. RESULTS: A collective of 1332 patients and 336 patients were respectively enrolled as the training cohort and the validation cohort in this study. Five variables including age, malignancy, oxygen saturation, blood glucose, and the use of vasopressor, were identified based on the results of the multivariate Cox regression model. The ROC value for the nomogram in the training cohort yielded 0.765, whereas in the validation group, it reached 0.907. Notably, these values surpassed the corresponding ROC values for the Pulmonary Embolism Severity Index, which were 0.713 in the training cohort and 0.754 in the validation cohort. CONCLUSIONS: The nomogram including five indicators had a good performance in predicting short-term prognosis in patients with APE, which was easier to apply and provided better recommendations for clinical decision-making.

Clonal Hematopoiesis of Indeterminate Potential in Chronic Thromboembolic Pulmonary Hypertension: A Multicenter Study.

BACKGROUND: The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is multifactorial and growing evidence has indicated that hematological disorders are involved. Clonal hematopoiesis of indeterminate potential (CHIP) has recently been associated with an increased risk of both hematological malignancies and cardiovascular diseases. However, the prevalence and clinical relevance of CHIP in patients with CTEPH remains unclear. METHODS: Using stepwise calling on next-generation sequencing data from 499 patients with CTEPH referred to 3 centers between October 2006 and December 2021, CHIP mutations were identified. We associated CHIP with all-cause mortality in patients with CTEPH. To provide insights into potential mechanisms, the associations between CHIP and inflammatory markers were also determined. RESULTS: In total, 47 (9.4%) patients with CTEPH carried at least 1 CHIP mutation at a variant allele frequency of ≥2%. The most common mutations were in DNMT3A, TET2, RUNX1, and ASXL1. During follow-up (mean, 55 months), deaths occurred in 22 (46.8%) and 104 (23.0%) patients in the CHIP and non-CHIP groups, respectively (P<0.001, log-rank test). The association of CHIP with mortality remained robust in the fully adjusted model (hazard ratio, 2.190 [95% CI, 1.257-3.816]; P=0.006). Moreover, patients with CHIP mutations showed higher circulating interleukin-1ß and interleukin-6 and lower interleukin-4 and IgG galactosylation levels. CONCLUSIONS: This is the first study to show that CHIP mutations occurred in 9.4% of patients with CTEPH are associated with a severe inflammatory state and confer a poorer prognosis in long-term follow-up.

Treatment of Cancer-Associated Thrombosis: Recent Advances, Unmet Needs, and Future Direction.

Cancer-associated thrombosis, with the incidence rising over the years, is associated with significant morbidity and mortality in patients with cancer. Recent advances in the treatment of cancer-associated venous thromboembolism (VTE) include the introduction of direct oral anticoagulants (DOACs), which provide a more convenient and effective option than low-molecular-weight heparin (LMWH). Nonetheless, important unmet needs remain including an increased risk of bleeding in certain patient subgroups such as those with gastroesophageal cancer, concerns about drug-drug interactions, and management of patients with severe renal impairment. Although DOACs are more convenient than LMWH, persistence can decline over time. Factor XI inhibitors have potential safety advantages over DOACs because factor XI appears to be essential for thrombosis but not hemostasis. In phase II trials, some factor XI inhibitors were superior to enoxaparin for the prevention of VTE after knee replacement surgery without increasing the risk of bleeding. Ongoing trials are assessing the efficacy and safety of factor XI inhibitors for the treatment of cancer-associated VTE.

Awareness of venous thromboembolism among patients with cancer: Preliminary findings from a global initiative for World Thrombosis Day.

BACKGROUND: Cancer-associated venous thromboembolism (CAT) has detrimental impact on patients' clinical outcomes and quality of life. Data on CAT education, communication, and awareness among the general cancer population are scanty. METHODS: We present the preliminary results of an ongoing patient-centered survey including 27 items covering major spheres of CAT. The survey, available in 14 languages, was promoted and disseminated online through social networks, email newsletters, websites, and media. RESULTS: As of September 20, 2022, 749 participants from 27 countries completed the survey. Overall, 61.8% (n = 460) of responders were not aware of their risk of CAT. Among those who received information on CAT, 26.2% (n = 56) were informed only at the time of CAT diagnosis. Over two thirds (69.1%, n = 501) of participants received no education on signs and symptoms of venous thromboembolism (VTE); among those who were educated about the possible clinical manifestations, 58.9% (n = 119) were given instructions to seek consultation in case of VTE suspicion. Two hundred twenty-four respondents (30.9%) had a chance to discuss the potential use of primary thromboprophylaxis with health-care providers. Just over half (58.7%, n = 309) were unaware of the risks of bleeding associated with anticoagulation, despite being involved in anticoagulant-related discussions or exposed to anticoagulants. Most responders (85%, n = 612) valued receiving CAT education as highly relevant; however, 51.7% (n = 375) expressed concerns about insufficient time spent and clarity of education received. CONCLUSIONS: This ongoing survey involving cancer patients with diverse ethnic, cultural, and geographical backgrounds highlights important patient knowledge gaps. These findings warrant urgent interventions to improve education and awareness, and reduce CAT burden.

18ß-Glycyrrhetinic acid ameliorates endoplasmic reticulum stress-induced inflammation in pulmonary arterial hypertension through PERK/eIF2α/NF-κB signaling.

Endoplasmic reticulum stress (ERS)-induced inflammation participates in the occurrence of pulmonary arterial hypertension (PAH) by promoting pulmonary vascular remodeling, which involved in the activation of PERK/eIF2α/NF-κB signaling pathway. 18ß-Glycyrrhetinic acid (18ß-GA) has been found efficacious for attenuating PAH through its anti-remodeling effects in our previous research and it remains unclear whether 18ß-GA has an effect on the remodeling caused by ERS-induced inflammation. In this study, we made observations in monocrotaline-induced PAH rats and found improvement of hemodynamic and histopathological parameters, decreases in the right ventricular hypertrophy index, and alleviation of pulmonary vascular remodeling after 18ß-GA administration in vivo. Moreover, 18ß-GA could significantly inhibit the proliferation and DNA synthesis of human pulmonary arterial smooth muscle cells (HPASMCs) induced by platelet-derived growth factor BB. At the cellular and molecular levels, we found that 18ß-GA could significantly reduce the accumulation of misfolded protein in rat lung tissue, inhibit ERS activation, reduce the expression of GRP78, p-PERK, p-eIF2α, and p-NF-κB p65, and increase IκB protein expression. 18ß-GA could inhibit the migration of NF-κB into the nucleus, reduce the contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and monocyte chemoattractant protein-1 (MCP-1) in the culture supernatant of HPASMCs, and reduce GRP78, p-PERK, p-eIF2α, p-NF-κB p65, TNF-α, IL-6, and MCP-1 protein expression, increase IκB protein expression in HPASMCs. According to what we observed, this study indicated that 18ß-GA could treat PAH, which is related to the inhibition of PERK/eIF2α/NF-κB signaling pathway.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL): A Novel Biomarker for Prognostic Assessment and Risk Stratification of Acute Pulmonary Embolism.

BACKGROUND: Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is associated with poor prognosis in cardiovascular diseases. However, the predictive value of TRAIL for the short-term outcome and risk stratification of acute pulmonary embolism (PE) remains unknown. METHODS: This study prospectively included 151 normotensive patients with acute PE. The study outcome was a composite of 30-day adverse events, defined as PE-related death, shock, mechanical ventilation, cardiopulmonary resuscitation, and major bleeding. RESULTS: Overall, nine of 151 (6.0%) patients experienced 30-day adverse composite events. Multivariable logistic regression showed that TRAIL was an independent predictor of study outcome (OR 0.19 per SD; 95% CI 0.04-0.90). An ROC curve revealed that TRAIL's area under the curve (AUC) was 0.83 (95% CI 0.76-0.88). The optimal cut-off value for TRAIL was 18 pg/mL, with a sensitivity, specificity, negative predictive value, positive predictive value, positive likelihood ratio, and negative likelihood ratio of 89%, 69%, 99%, 15%, 2.87, and 0.16, respectively. Compared with the risk stratification algorithm outlined in the 2019 ESC guidelines, our biomarker-based risk stratification strategy (combining TRAIL and hs-cTnI) has a similar risk classification effect. CONCLUSION: Reduced plasma TRAIL levels predict short-term adverse events in normotensive patients with acute PE. The combination of the 2019 ESC algorithm and TRAIL aids risk stratification in normotensive patients with acute PE.

Plasma metabolomics in the perioperative period of defect repair in patients with pulmonary arterial hypertension associated with congenital heart disease.

The quality of life and survival rates of patients with pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH) have been greatly improved by defect-repair surgery and personalized treatments. However, those who survive surgery may remain at risk of persistent PAH, the prognosis may be considerably worse than those unoperated. Dynamic monitoring of clinical measures during the perioperative period of shunt correction is therefore indispensable and of great value. In this study, we explored the plasma-metabolite profiling in 13 patients with CHD-PAH during the perioperative period of defect repair. Plasma was harvested at four time points: prior to cardiopulmonary bypass (CPB) after anesthesia (Pre), immediately after CPB (T0), 24 h (T24), and 48 h (T48) after defect repair. Untargeted metabolomics strategy based on UPLC Q-TOF MS was used to detect the metabolites. A total of 193 distinguishing metabolites were determined at different time points, enriched in pathways such as oxidation of branched-chain fatty acids. We found that 17 metabolite alterations were significantly correlated with the reduction in mean pulmonary arterial pressure (MPAP) at T48 versus Pre. Gradients in diastolic pulmonary arterial pressure (DPAP), bicarbonate in radial artery (aHCO3), bicarbonate in superior vena cava (svcHCO3), and the partial pressure of dissolved CO2 gas in radial artery (aPCO2) were positively correlated with MPAP gradient. Notably, these clinical-measure gradients were correlated with alterations in shunt-correction-associated metabolites. In total, 12 out of 17 identified metabolites in response to defect repair were increased at both T24 and T48 (all P < 0.05, except propionylcarnitine with P < 0.05 at T24). In contrast, galactinol dihydrate, guanosine monophosphate, and hydroxyphenylacetylglycine tended to decline at T24 and T48 (only galactinol dihydrate with P < 0.05 at T48). In conclusion, 17 metabolites that respond to shunt correction could be used as suitable noninvasive markers, and clinical measures, including DPAP, aHCO3, svcHCO3, and aPCO2, would be of great value in disease monitoring and evaluating future therapeutic interventions.

Subendocardial Involvement as an Underrecognized Cardiac MRI Phenotype in Myocarditis.

Background Subendocardial late gadolinium enhancement (LGE) detected with cardiac MRI in myocarditis represents a diagnostic dilemma, since it may resemble myocardial ischemia. Purpose To explore and compare the histopathologic characteristics and clinical features and outcomes in patients with myocarditis with and without subendocardial involvement at cardiac MRI. Materials and Methods This retrospective study evaluated 39 patients with myocarditis pathologically proven by means of either endomyocardial biopsy or explant pathologic findings between 2015 and 2020. Patients were divided into two groups according to cardiac MRI phenotype: 18 with subendocardial involvement (mean age ± standard deviation, 40 years ± 17; 10 women) and 21 with no subendocardial involvement (mean age, 35 years ± 11; six women). The median follow-up period was 784 days (interquartile range [IQR], 90-1123 days). The Student t test, Mann-Whitney U test, and univariable Cox regression were used for statistical analyses. Results In the 18 patients with subendocardial involvement, 12 (67%) had lymphocytic myocarditis and six (33%) had giant cell myocarditis. Patients with subendocardial involvement compared with those without subendocardial involvement had lower left ventricular ejection fraction (mean ± standard deviation, 27% ± 11 vs 41% ± 19; P = .004), larger LGE extent (median, 13% [IQR, 10%-22%] vs 5% [IQR, 2%-17%]; P < .001), higher rates of cardiac death or transplant (eight of 18 patients [44%] vs one of 21 patients [4.8%]; P = .006), higher probability of giant cell myocarditis (six of 18 [33%] vs one of 21 [4.8%]; P = .02), and more major adverse cardiovascular events (MACE) (15 of 18 [83%] vs seven of 21 [33%]; P = .002). In a subgroup of patients with comparable LGE extent (median, 15% vs 16%; P = .40) and left ventricular ejection fraction (median, 27% vs 31%; P = .26), the prognostic difference in terms of MACE remained (15 of 17 patients [88%] vs five of 10 [50%]; P = .02). Conclusion Subendocardial involvement detected with cardiac MRI in myocarditis indicated more severe clinical features, including a higher frequency of severe lymphocytic myocarditis or giant cell myocarditis and worse prognosis. © RSNA, 2021 See also the editorial by de Roos in this issue.

Venous thromboembolism in Asia and worldwide: Emerging insights from GARFIELD-VTE.

BACKGROUND: Although epidemiological studies report a lower risk of venous thromboembolism (VTE) than in the Western world, VTE rates in Asia may be underestimated. Furthermore, it is uncertain whether VTE outcomes differ in Asia and the rest of the world (ROW). METHODS: GARFIELD-VTE is a global, prospective, non-interventional study of real-world treatment practices. In this study, we compared baseline characteristics, treatment patterns, and 12-month outcomes in Asia and ROW. RESULTS: Of the 10,684 enrolled patients, 1822 (17.1%) were Asian (China n = 420, Hong Kong n = 98, Japan n = 148, Malaysia n = 244, South Korea n = 343, Taiwan n = 232, Thailand n = 337). Compared with ROW patients, those from Asia were more often female (57.4% vs. 48.0%), non-smokers (74.0% vs. 58.9%) and had a lower BMI (24.8 kg/m2 vs. 29.1 kg/m2). Asian patients were more likely to be managed in the hospital (86.9% vs. 70.4%) and to have active cancer (19.8% vs. 8.1%) or a history of cancer (19.1% vs. 12.0%). Asian patients received no anticoagulation more frequently than ROW patients (6.5% vs. 2.1%). Over 12-months follow-up, the rate of all-cause mortality (per 100 person-years [95% confidence interval]) was higher in Asians (15.2 [13.4-17.3] vs. 5.9 [5.4-6.5]). Adjusted hazard ratios indicated a higher risk of all-cause mortality in Asian patients than the ROW (1.32 [1.08-1.62]). The frequencies of major bleeding and recurrent VTE were similar. CONCLUSION: Asian patients have different risk profiles, treatment patterns and a higher risk of mortality compared with the ROW.

Protective effects of isorhamnetin on pulmonary arterial hypertension: in vivo and in vitro studies.

Pulmonary arterial hypertension (PAH) is a malignant disease with high mortality and closely involves the bone morphogenetic protein (BMP) pathway. Mutations in BMPR2 caused proliferation of pulmonary artery smooth muscle cells (PASMCs) leading to PAH. Isorhamnetin, one of the main naturally occurring flavonoids extracted from Hippophae rhamnoides L, shows antiinflammatory and anti-proliferative properties. Nevertheless, the effects of isorhamnetin on PAH remain unclear. This study aimed to investigate whether isorhamnetin has protective effects against PAH and explore possible mechanisms. An in vivo model of PAH induced by monocrotaline (MCT) was employed, and sildenafil and isorhamnetin were orally administered for 21 consecutive days. An in vitro model induced by TNF-α was employed, and cell proliferation of HPASMCs was detected. Results indicated that isorhamnetin significantly improved hemodynamic, histopathological, and echocardiographic changes in MCT-induced PAH in rats. In vitro, isorhamnetin suppressed TNF-α-induced HPASMCs proliferation. Furthermore, isorhamnetin improved protein expression of BMPR2 and suppressed protein expression of TNF-α and IL-6 in rat lungs. Isorhamnetin improved protein expression of BMPR2 and p-smad1/5 and mRNA expression of Id1 and Id3 in HPASMCs. Isorhamnetin ameliorated MCT-induced PAH in rats and inhibited TNF-α-induced HPASMCs proliferation by a mechanism likely involving the regulation of the BMP signaling pathway.

Association Between High FSH, Low Progesterone, and Idiopathic Pulmonary Arterial Hypertension in Women of Reproductive Age.

BACKGROUND: While sex differences characterize susceptibility and severity of idiopathic pulmonary arterial hypertension (IPAH), our understanding of the relationship between levels of gonadotropins and sex hormones in fertile women and the disease is limited. We aimed to investigate whether gonadotropin and sex hormone levels in women of reproductive age were associated with risk and mortality of IPAH. METHODS: We did a matched case-control study. Cases were reproductive female patients with idiopathic pulmonary arterial hypertension admitted in Shanghai Pulmonary Hospital (Tongji University School of Medicine, Shanghai, China) during 2008-2014. Healthy controls were matched on age and body mass index. We also did a prospective cohort study to assess the effects of hormone levels on mortality in IPAH fertile female patients. RESULTS: One hundred sixty-four cases and 133 controls were included. After adjustment for age and body mass index, the odds ratios of having IPAH for follicle-stimulating hormone, testosterone, and progesterone as expressed on natural log scale were 1.51 (95% confidence interval: 1.06, 2.16), 0.42 (0.31-0.57), and 0.52 (0.43-0.63), respectively. In the cohort study with a median follow-up of 77 months, the hazard ratios for dying after adjustment for baseline characteristics and treatments among IPAH patients were 2.01 (95% confidence interval: 1.22-3.30) and 0.78 (95% confidence interval: 0.62-0.98) for follicle-stimulating hormone and progesterone in natural log scale, respectively. CONCLUSIONS: In reproductive women with IPAH, high follicle-stimulating hormone and low progesterone tended to be associated with high risk of IPAH and mortality among patients.

Lipocalin-2 Predicts Long-Term Outcome of Normotensive Patients with Acute Pulmonary Embolism.

Normotensive patients with acute pulmonary embolism (APE) are accompanied by heterogeneously adverse events. Responding to tissue injury, lipocalin-2 (LCN-2) is elevated in experimental APE model and associated with short-term prognosis. However, the prognostic value of LCN-2 in normotensive patients with APE for long-term major adverse events (MAEs) remains unknown. We evaluated the association of plasma LCN-2 levels with the median 467-day outcome in 170 normotensive patients with APE. We also assessed whether LCN-2 could improve risk stratification. MAEs consisted of mortality or recurrence of venous thromboembolism. During follow-up, 17 (10%) patients suffered from MAEs. These patients had higher LCN-2 levels compared with patients without MAEs (median: 13.97 vs. 8.55 ng/ml, P = 0.01). The proportion of MAEs in the intermediate-low-risk group (14.0%) was higher than that in the intermediate-high-risk group (5.3%). LCN-2 levels independently had prognostic value for MAEs in overall (HR = 3.40, 95% CI 1.46-7.90) and intermediate-risk group (HR = 3.88, 95% CI 1.63-9.23). LCN-2 also showed incremental value in overall (ΔC-index: 0.13, 95% CI 0.02-0.24; category-based NRI = 0.25, 95% CI 0.07-0.42) and intermediate-risk patients (ΔC-index: 0.13, 95% CI 0.05-0.31; category-based NRI = 0.44, 95% CI 0.24-0.65). Adding LCN-2 (cut-off value = 11 ng/ml) to the current risk algorithm improved MAEs of intermediate-risk reclassification (intermediate-high vs. intermediate-low = 25.6% vs. 6.0%, P = 0.002). Elevated plasma LCN-2 levels predict long-term MAEs among normotensive patients with APE. LCN-2 might be a useful biomarker for risk stratification in the intermediate-risk group.

Adventitial Cell Atlas of wt (Wild Type) and ApoE (Apolipoprotein E)-Deficient Mice Defined by Single-Cell RNA Sequencing.

Objective- Vascular adventitia encompasses progenitors and is getting recognized as the major site of inflammation in early stage of atherosclerosis. However, the cellular atlas of the heterogeneous adventitial cells, the intercellular communication, the cellular response of adventitia to hyperlipidemia, and its contribution to atherosclerosis have been elusive. Approach and Results- Single-cell RNA sequencing was applied to wt (wild type) and ApoE (apolipoprotein E)-deficient aortic adventitia from 12-week-old C57BL/6J mice fed on normal laboratory diet with early stage of atherosclerosis. Unbiased clustering analysis revealed that the landscape of adventitial cells encompassed adventitial mesenchyme cells, immune cells (macrophages, T cells, and B cells), and some types of rare cells, for example, neuron, lymphatic endothelial cells, and innate lymphoid cells. Seurat clustering analysis singled out 6 nonimmune clusters with distinct transcriptomic profiles, in which there predominantly were stem/progenitor cell-like and proinflammatory population (Mesen II). In ApoE-deficient adventitia, resident macrophages were activated and related to increased myeloid cell infiltration in the adventitia. Cell communication analysis further elucidated enhanced interaction between a mesenchyme cluster and inflammatory macrophages in ApoE-deficient adventitia. In vitro transwell assay confirmed the proinflammatory role of SCA1+ (stem cell antigen 1 positive) Mesen II population with increased CCL2 (chemokine [C-C motif] ligand 2) secretion and thus increased capacity to attract immune cells in ApoE-deficient adventitia. Conclusions- Cell atlas defined by single-cell RNA sequencing depicted the heterogeneous cellular landscape of the adventitia and uncovered several types of cell populations. Furthermore, resident cell interaction with immune cells appears crucial at the early stage of atherosclerosis.

Characteristics of cardiopulmonary exercise testing of patients with borderline mean pulmonary artery pressure.

BACKGROUND: Pulmonary hypertension patients with mean pulmonary artery pressure (mPAP) ≥ 25 mm Hg had impaired cardiopulmonary exercise testing (CPET). Borderline mean pulmonary pressures (boPAP; 21-24 mm Hg) represent early pulmonary vasculopathy. The CPET characteristics of boPAP are a matter of discussion. We aimed to determine the CPET profile of such borderline hemodynamics. METHODS: A matched case-control study was conducted on consecutive boPAP patients at the Shanghai Pulmonary Hospital between Jan 2012 and Jan 2017. Hemodynamics, echocardiography, the pulmonary function test (PFT) and CPET parameters were compared between boPAP patients and normal mPAP patients which were matched 1:1 by sex and age. Conditional logistic regression analysis was performed to determine the efficacy of CPET in detecting boPAP. RESULTS: A total of 48 patients underwent RHC and CPET (24 Normal, 24 boPAP). There were no differences in the demographics, echocardiography and PFT. BoPAP patients had significantly decreased VO2 at the anaerobic threshold and peak VO2 /kg (858.4 ± 246.5 mL/min vs 727.9 ± 228.0 mL/min, P = 0.037; 21.1 ± 6.4 mL/min/kg vs. 15.5 ± 5.6 mL/min/kg, P = 0.001, respectively). Significant differences were not observed in ventilation efficiency. A trend of impaired oxygen pulse and submaximal exercise tolerance were observed in boPAP patients. Conditional logistical regression analysis revealed the risk of boPAP increased by 2.493 (95% confident interval: 1.388 to 4.476, P = 0.002) with every 5 mL/min/kg decrease in peak VO2 /kg. CONCLUSIONS: Patients with boPAP have a greater prevalence of exercise intolerance, a trend of impaired oxygen pulse and submaximal exercise tolerance.

Spermine on Endothelial Extracellular Vesicles Mediates Smoking-Induced Pulmonary Hypertension Partially Through Calcium-Sensing Receptor.

Objective- This study aims to determine whether and how the enriched metabolites of endothelial extracellular vesicles (eEVs) are critical for cigarette smoke-induced direct injury of endothelial cells and the development of pulmonary hypertension, rarely explored in contrast to long-investigated mechanisms secondary to chronic hypoxemia. Approach and Results- Metabonomic screen of eEVs from cigarette-smoking human subjects reveals prominent elevation of spermine-a polyamine metabolite with potent agonist activity for the extracellular CaSR (calcium-sensing receptor). CaSR inhibition with the negative allosteric modulator Calhex231 or CaSR knockdown attenuates cigarette smoke-induced pulmonary hypertension in rats without emphysematous changes in lungs or chronic hypoxemia. Cigarette smoke exposure increases the generation of spermine-positive eEVs and their spermine content. Immunocytochemical staining and immunogold electron microscopy recognize the spermine enrichment not only within the cytosol but also on the outer surface of eEV membrane. The repression of spermine synthesis, the inhibitory analog of spermine, N1-dansyl-spermine, Calhex231, or CaSR knockdown profoundly suppresses eEV exposure-mobilized cytosolic calcium signaling, pulmonary artery constriction, and smooth muscle cell proliferation. Confocal imaging of immunohistochemical staining demonstrates the migration of spermine-positive eEVs from endothelium into smooth muscle cells in pulmonary arteries of cigarette smoke-exposed rats. The repression of spermine synthesis or CaSR knockout results in attenuated development of pulmonary hypertension induced by an intravascular administration of eEVs. Conclusions- Cigarette smoke enhances eEV generation with spermine enrichment at their outer surface and cytosol, which activates CaSR and subsequently causes smooth muscle cell constriction and proliferation, therefore, directly leading to the development of pulmonary hypertension.

3-Bromopyruvate Attenuates Experimental Pulmonary Hypertension via Inhibition of Glycolysis.

BACKGROUND: The shift of metabolism from mitochondrial oxidative phosphorylation to glycolysis and mitochondria binding partner of hexokinase are features common to cancer. These have been seen in pulmonary hypertension (PH) as well. An inhibitor of hexokinase 2 (HK 2), the small molecule 3-bromopyruvate (3-BrPA) is an incredibly powerful and swift-acting anticancer agent. However, whether it could be of potential benefit to PH has still been unknown. METHODS: Sprague-Dawley rats with monocrotaline (MCT)-induced PH were administered 2 oral doses of 3-BrPA (15 and 30 mg/kg/day, respectively) for 14 days. Hemodynamic parameters were obtained by right heart catheterization. Histopathology, immunohistochemistry, transmission electron microscopy, flow cytometry, and assessments of relative protein expressions were conducted. RESULTS: Compared with MCT treatment, 3-BrPA decreased mean pulmonary arterial pressure and pulmonary vascular resistance, and increased cardiac output. 3-BrPA significantly suppressed proliferation in addition to enhancing apoptosis of pulmonary artery smooth muscle cells, attenuating small pulmonary artery remodeling and right ventricular hypertrophy. Treatment with 3-BrPA markedly reduced the mitochondrial membrane potential and restored mitochondrial structure. Furthermore, 3-BrPA significantly inhibited HK 2 expression but not HK 1. The expression of both pyruvate dehydrogenase kinase and lactate dehydrogenase was decreased whereas that of pyruvate dehydrogenase and cytosolic cytochrome c was upregulated with 3-BrPA administration. CONCLUSION: This study demonstrates the reversal of PH by 3-BrPA is related to alteration in glycolysis and improved mitochondria function, indicating the "metabolic targeting" as a rational therapeutic strategy for PH.

Inhibition of CRTH2-mediated Th2 activation attenuates pulmonary hypertension in mice.

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by progressive pulmonary artery (PA) remodeling. T helper 2 cell (Th2) immune response is involved in PA remodeling during PAH progression. Here, we found that CRTH2 (chemoattractant receptor homologous molecule expressed on Th2 cell) expression was up-regulated in circulating CD3+CD4+ T cells in patients with idiopathic PAH and in rodent PAH models. CRTH2 disruption dramatically ameliorated PA remodeling and pulmonary hypertension in different PAH mouse models. CRTH2 deficiency suppressed Th2 activation, including IL-4 and IL-13 secretion. Both CRTH2+/+ bone marrow reconstitution and CRTH2+/+ CD4+ T cell adoptive transfer deteriorated hypoxia + ovalbumin-induced PAH in CRTH2-/- mice, which was reversed by dual neutralization of IL-4 and IL-13. CRTH2 inhibition alleviated established PAH in mice by repressing Th2 activity. In culture, CRTH2 activation in Th2 cells promoted pulmonary arterial smooth muscle cell proliferation through activation of STAT6. These results demonstrate the critical role of CRTH2-mediated Th2 response in PAH pathogenesis and highlight the CRTH2 receptor as a potential therapeutic target for PAH.

Impact of Pituitary-Gonadal Axis Hormones on Pulmonary Arterial Hypertension in Men.

The association of sex hormone (estradiol, testosterone, and progesterone) with cardiopulmonary disease has already attracted great attention, especially in pulmonary arterial hypertension (PAH). However, the impact of sex hormones and their pituitary stimulators (follicle-stimulating hormone and luteinizing hormone) on PAH in men remains unclear. We conducted a prospective cohort study recruiting 95 patients with idiopathic PAH from 2008 to 2014 and following up for a median of 65 months for death. Compared with control, abnormal plasma levels of sex hormones were more common in patients with PAH. Higher estradiol and estradiol/testosterone levels were associated with risk of PAH diagnosis (odds ratio per ln estradiol, 3.55; P<0.001; odds ratio per ln estradiol/testosterone, 4.30; P<0.001), whereas higher testosterone and progesterone were associated with a reduced risk (odds ratio per ln testosterone, 0.48; P=0.003; odds ratio per ln progesterone, 0.09; P<0.001). Fifty patients died during follow-up. Men with higher estradiol had increased mortality (hazard ratio per ln estradiol, 2.02; P=0.007), even after adjustment for baseline characteristics and PAH treatment. According to receiver operating characteristic analysis, patients with PAH with higher estradiol level (≥145.55 pmol/L) had worse 5-year survival rate compared with those with lower estradiol (38.6% versus 68.2%; log-rank test P=0.001). Therefore, our data show higher estradiol, estradiol/testosterone ratio, lower testosterone, and progesterone were associated with increased risk of PAH. Meanwhile, higher estradiol was independently associated with higher mortality in men with PAH. Further studies are needed to explain the origin of these hormonal derangements and their potential pathophysiological implications in PAH.