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Rationale: Previous studies have shown that approximately 55% of patients with familial pulmonary arterial hypertension (FPAH) have BMPR2 coding sequence mutations. However, direct sequencing does not detect other types of heterozygous mutations, such as exonic deletions/duplications.Objective: To estimate the frequency of BMPR2 exonic deletions/duplications in FPAH.Methods: BMPR2 mRNA from lymphoblastoid cell lines of 30 families with PAH and 14 patients with idiopathic PAH (IPAH) was subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) and sequencing. Sequencing of genomic DNA was used to identify point mutations in splice donor/acceptor sites. Multiplex ligation-dependent probe amplification (MLPA) was used to detect exonic deletions/duplications with verification by real-time PCR.Measurements and Main Results: Eleven (37%) patients with FPAH had abnormally sized RT-PCR products. Four of the 11 patients were found to have splice-site mutations resulting in aberrant splicing, and exonic deletions/duplications were detected in the remaining seven patients. MLPA identified three deletions/duplications that were not detectable by RT-PCR. Coding sequence point mutations were identified in 11 of 30 (37%) patients. Mutations were identified in 21 of 30 (70%) patients with FPAH, with 10 of 21 mutations (48%) being exonic deletions/duplications. Two of 14 (14%) patients with IPAH exhibited BMPR2 point mutations, whereas none showed exonic deletions/duplications.Conclusions: Our study indicates that BMPR2 exonic deletions/duplications in patients with FPAH account for a significant proportion of mutations (48%) that until now have not been screened for. Because the complementary approach used in this study is rapid and cost effective, screening for BMPR2 deletions/duplications by MLPA and real-time PCR should accompany direct sequencing in all PAH testing. [ABSTRACT FROM AUTHOR]

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene cause some forms of autosomal dominant Parkinson's disease. We measured the frequency of a novel mutation (Gly2019 ser) in familial Parkinson's disease by screening genomic DNA of patients and controls. Of 767 affected individuals from 358 multiplex families, 35 (5%) individuals were either heterozygous (34) or homozygous (one) for the mutation, and had typical clinical findings of idiopathic Parkinson's disease. Thus, our results suggest that a single LRRK2 mutation causes Parkinson's disease in 5% of individuals with familial disease. Screening for this mutation should be a component of genetic testing for Parkinson's disease. [ABSTRACT FROM AUTHOR]

Background: Activation of the complement cascade is thought to play a role in scleroderma vasculopathy. We previously showed that complement factor D was elevated in patients with limited cutaneous SSc and pulmonary arterial hypertension (PAH). In this study, we sought to assess multiple relevant components of the complement cascade to determine if they are altered in SSc-PAH, as well as their potential utility as biomarkers of disease severity and progression., Methods: Complement components (n = 14) were measured using multiplex assays in 156 patients with SSc-PAH from a multi-site repository and were compared to 33 patients with SSc without PAH, and 40 healthy controls. Data were evaluated for correlations between complement levels, right heart catheterization measures, and clinical endpoints including 6-minute walk distance. To assess complement longitudinally, serum complement levels were assayed at 0, 4, 12, 24, 36 and 48 weeks in 52 SSc-PAH patients who participated in a prior clinical trial., Results: We found that factor D was significantly elevated in SSc-PAH compared to SSc without PAH (p < 0.0001) and was highly sensitive and specific for SSc-PAH (AUC=0.82, p < 0.001). In SSc-PAH patients, alterations in factor H, C4, and factor D were associated with measures of PAH disease severity including right heart catheterization measurements (cardiac output, right atrial pressure, and VO2 max), survival, and 6-minute walk distance. No significant changes in complement levels or clinical associations were seen over time or associated with treatment in the longitudinal clinical trial study., Conclusion: Our work confirms prior studies demonstrating a role for complement activation in SSc vascular disease and elevations of factor D in a large SSc-PAH population. Further, factor H and other complement factors are associated with severity of PAH including mortality. Taken together, these findings suggest that the alternative complement pathway plays a role in SSc-PAH pathogenesis and may serve as a biomarker to inform diagnosis and prognosis., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: VMH is a co-founder of Q32 Bio, has stock and has previously received sponsored research support, (Copyright © 2024 Elsevier Inc. All rights reserved.)

Considerable progress has been made in the genomics of pulmonary arterial hypertension (PAH) since the 6th World Symposium on Pulmonary Hypertension, with the identification of rare variants in several novel genes, as well as common variants that confer a modest increase in PAH risk. Gene and variant curation by an expert panel now provides a robust framework for knowing which genes to test and how to interpret variants in clinical practice. We recommend that genetic testing be offered to specific subgroups of symptomatic patients with PAH, and to children with certain types of group 3 pulmonary hypertension (PH). Testing of asymptomatic family members and the use of genetics in reproductive decision-making require the involvement of genetics experts. Large cohorts of PAH patients with biospecimens now exist and extension to non-group 1 PH has begun. However, these cohorts are largely of European origin; greater diversity will be essential to characterise the full extent of genomic variation contributing to PH risk and treatment responses. Other types of omics data are also being incorporated. Furthermore, to advance gene- and pathway-specific care and targeted therapies, gene-specific registries will be essential to support patients and their families and to lay the foundation for genetically informed clinical trials. This will require international outreach and collaboration between patients/families, clinicians and researchers. Ultimately, harmonisation of patient-derived biospecimens, clinical and omic information, and analytic approaches will advance the field., Competing Interests: Conflict of interest: E.D. Austin reports grants from NIH (R01FD007627; 1R01HL134802; T32HL160508; R01HL169859; R34HL173389; 5P01HL108800) and the Cardiovascular Medical Research Fund, payment or honoraria for lectures, presentations, manuscript writing or educational events from Acceleron, Inc., participation on a data safety monitoring board or advisory board with NIH, and leadership roles with PHA and TBX4Life. M. Alotaibi reports grants from NIH. M.A. Aldred reports grants from NHLBI and a leadership role with the International Consortium for Genetics Studies in PAH (PAH-ICON). W.C. Nichols reports grants from NIH/NHLBI. R.C. Trembath reports support for attending meetings from conference organisers. The remaining authors have no potential conflicts of interest to disclose., (Copyright ©The authors 2024.)

Background: Integrative multiomics can elucidate pulmonary arterial hypertension (PAH) pathobiology, but procuring human PAH lung samples is rare., Methods: We leveraged transcriptomic profiling and deep phenotyping of the largest multicenter PAH lung biobank to date (96 disease and 52 control) by integration with clinicopathologic data, genome-wide association studies, Bayesian regulatory networks, single-cell transcriptomics, and pharmacotranscriptomics., Results: We identified 2 potentially protective gene network modules associated with vascular cells, and we validated ASPN , coding for asporin, as a key hub gene that is upregulated as a compensatory response to counteract PAH. We found that asporin is upregulated in lungs and plasma of multiple independent PAH cohorts and correlates with reduced PAH severity. We show that asporin inhibits proliferation and transforming growth factor-β/phosphorylated SMAD2/3 signaling in pulmonary artery smooth muscle cells from PAH lungs. We demonstrate in Sugen-hypoxia rats that ASPN knockdown exacerbated PAH and recombinant asporin attenuated PAH., Conclusions: Our integrative systems biology approach to dissect the PAH lung transcriptome uncovered asporin as a novel protective target with therapeutic potential in PAH.

Background: Risk assessment in pulmonary arterial hypertension (PAH) is fundamental to guiding treatment and improved outcomes. Clinical models are excellent at identifying high-risk patients, but leave uncertainty amongst moderate-risk patients., Research Question: Can a multiple blood biomarker model of PAH, using previously described biomarkers, improve risk discrimination over current models?, Study Design and Methods: Using a multiplex enzyme-linked immunosorbent assay, we measured N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP), soluble suppressor of tumorigenicity, IL-6, endostatin, galectin 3, HDGF, and insulin-like growth factor binding proteins (IGFBP1-7) in training (n = 1,623), test (n = 696), and validation (n = 237) cohorts. Clinical variables and biomarkers were evaluated by principal component analysis. NT-proBNP was not included to develop a model independent of NT-proBNP. Unsupervised k-means clustering classified participants into clusters. Transplant-free survival by cluster was examined using Kaplan-Meier and Cox proportional hazard regressions. Hazard by cluster was compared with NT-proBNP, Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL), and European Society of Cardiology (ESC) and European Respiratory Society (ERS) risk models alone and combined clinical and biomarker models., Results: The algorithm generated 5 clusters with good risk discrimination using 6 biomarkers, weight, height, and age at PAH diagnosis. In the test and validation cohorts, the biomarker model alone performed equivalent to REVEAL (area under the receiver operating characteristic curve, 0.74). Adding the biomarker model to the ESC and ERS score and REVEAL score improved the ESC and ERS score and REVEAL score. The best overall model was the biomarker model adjusted for NT-proBNP with the best C statistic, Akaike information criterion, and calibration for the adjusted model compared with either the biomarker or NT-proBNP model alone., Interpretation: A multibiomarker model alone was equivalent to current PAH clinical mortality risk prediction models and improved performance when combined and added to NT-proBNP. Clinical risk scores offer excellent predictive models, but require multiple tests; adding blood biomarkers to models can improve prediction or can enable more frequent, noninvasive monitoring of risk in PAH to support therapeutic decision-making., Competing Interests: Financial/Nonfinancial Disclosures None declared., (Copyright © 2024 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: The ubiquitin-proteasome system regulates protein degradation and the development of pulmonary arterial hypertension (PAH), but knowledge about the role of deubiquitinating enzymes in this process is limited. UCHL1 (ubiquitin carboxyl-terminal hydrolase 1), a deubiquitinase, has been shown to reduce AKT1 (AKT serine/threonine kinase 1) degradation, resulting in higher levels. Given that AKT1 is pathological in pulmonary hypertension, we hypothesized that UCHL1 deficiency attenuates PAH development by means of reductions in AKT1., Methods: Tissues from animal pulmonary hypertension models as well as human pulmonary artery endothelial cells from patients with PAH exhibited increased vascular UCHL1 staining and protein expression. Exposure to LDN57444, a UCHL1-specific inhibitor, reduced human pulmonary artery endothelial cell and smooth muscle cell proliferation. Across 3 preclinical PAH models, LDN57444-exposed animals, Uchl1 knockout rats ( Uchl1 -/- ), and conditional Uchl1 knockout mice ( Tie2Cre-Uchl1 fl/fl ) demonstrated reduced right ventricular hypertrophy, right ventricular systolic pressures, and obliterative vascular remodeling. Lungs and pulmonary artery endothelial cells isolated from Uchl1 -/- animals exhibited reduced total and activated Akt with increased ubiquitinated Akt levels. UCHL1-silenced human pulmonary artery endothelial cells displayed reduced lysine(K)63-linked and increased K48-linked AKT1 levels., Results: Supporting experimental data, we found that rs9321, a variant in a GC-enriched region of the UCHL1 gene, is associated with reduced methylation (n=5133), increased UCHL1 gene expression in lungs (n=815), and reduced cardiac index in patients (n=796). In addition, Gadd45α (an established demethylating gene) knockout mice ( Gadd45α -/- ) exhibited reduced lung vascular UCHL1 and AKT1 expression along with attenuated hypoxic pulmonary hypertension., Conclusions: Our findings suggest that UCHL1 deficiency results in PAH attenuation by means of reduced AKT1, highlighting a novel therapeutic pathway in PAH., Competing Interests: None.

Background: Abnormal remodeling of distal pulmonary arteries in patients with pulmonary arterial hypertension (PAH) leads to progressively increased pulmonary vascular resistance, followed by right ventricular hypertrophy and failure. Despite considerable advancements in PAH treatment prognosis remains poor. We aim to evaluate the potential for using the cytokine resistin as a genetic and biological marker for disease severity and survival in a large cohort of patients with PAH., Methods: Biospecimens, clinical, and genetic data for 1121 adults with PAH, including 808 with idiopathic PAH (IPAH) and 313 with scleroderma-associated PAH (SSc-PAH), were obtained from a national repository. Serum resistin levels were measured by ELISA, and associations between resistin levels, clinical variables, and single nucleotide polymorphism genotypes were examined with multivariable regression models. Machine-learning (ML) algorithms were applied to develop and compare risk models for mortality prediction., Results: Resistin levels were significantly higher in all PAH samples and PAH subtype (IPAH and SSc-PAH) samples than in controls (P < .0001) and had significant discriminative abilities (AUCs of 0.84, 0.82, and 0.91, respectively; P < .001). High resistin levels (above 4.54 ng/mL) in PAH patients were associated with older age (P = .001), shorter 6-min walk distance (P = .001), and reduced cardiac performance (cardiac index, P = .016). Interestingly, mutant carriers of either rs3219175 or rs3745367 had higher resistin levels (adjusted P = .0001). High resistin levels in PAH patients were also associated with increased risk of death (hazard ratio: 2.6; 95% CI: 1.27-5.33; P < .0087). Comparisons of ML-derived survival models confirmed satisfactory prognostic value of the random forest model (AUC = 0.70, 95% CI: 0.62-0.79) for PAH., Conclusions: This work establishes the importance of resistin in the pathobiology of human PAH. In line with its function in rodent models, serum resistin represents a novel biomarker for PAH prognostication and may indicate a new therapeutic avenue. ML-derived survival models highlighted the importance of including resistin levels to improve performance. Future studies are needed to develop multi-marker assays that improve noninvasive risk stratification., (© 2024. The Author(s).)

Hypoxic reprogramming of vasculature relies on genetic, epigenetic, and metabolic circuitry, but the control points are unknown. In pulmonary arterial hypertension (PAH), a disease driven by hypoxia inducible factor (HIF)-dependent vascular dysfunction, HIF-2α promoted expression of neighboring genes, long noncoding RNA (lncRNA) histone lysine N -methyltransferase 2E-antisense 1 ( KMT2E-AS1 ) and histone lysine N-methyltransferase 2E ( KMT2E ). KMT2E-AS1 stabilized KMT2E protein to increase epigenetic histone 3 lysine 4 trimethylation (H3K4me3), driving HIF-2α-dependent metabolic and pathogenic endothelial activity. This lncRNA axis also increased HIF-2α expression across epigenetic, transcriptional, and posttranscriptional contexts, thus promoting a positive feedback loop to further augment HIF-2α activity. We identified a genetic association between rs73184087, a single-nucleotide variant (SNV) within a KMT2E intron, and disease risk in PAH discovery and replication patient cohorts and in a global meta-analysis. This SNV displayed allele (G)-specific association with HIF-2α, engaged in long-range chromatin interactions, and induced the lncRNA-KMT2E tandem in hypoxic (G/G) cells. In vivo, KMT2E-AS1 deficiency protected against PAH in mice, as did pharmacologic inhibition of histone methylation in rats. Conversely, forced lncRNA expression promoted more severe PH. Thus, the KMT2E-AS1 /KMT2E pair orchestrates across convergent multi-ome landscapes to mediate HIF-2α pathobiology and represents a key clinical target in pulmonary hypertension.

Insulin-like growth factor (IGF) binding proteins (IGFBPs) are a family of growth factor modifiers, some of which are known to be independently associated with pulmonary arterial hypertension (PAH) survival. IGF factor binding protein 7 (IGFBP7) is a unique low-affinity IGFBP that, independent of IGF, stimulates prostacyclin production. This study proposed to establish associations between IGFBP7 and PAH severity and survival, using enrollment and longitudinal samples. Serum IGFBP7 levels were significantly elevated in patients with PAH compared to controls. After adjusting for age and sex, logarithmic increases in IGFBP7 were associated with a 20 m shorter six-minute walk distance (6MWD; p  < 0.001), a 2-3 mmHg higher mean right atrial pressure ( p  < 0.001 and 0.02), and a higher likelihood of a greater REVEAL 2.0 risk category placement ( p  < 0.001). Kaplan-Meier analysis demonstrated significantly decreased survival with IGFBP7 above the median and Cox multivariable analysis adjusted for age and sex, demonstrated higher serum IGFBP7 was an independent predictor of survival. Though the exact mechanism is still unknown, given IGFBP7's role as a prostacyclin stimulant, it has potential use as a therapeutic target for disease modulation., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Portopulmonary hypertension (PoPH) is a type of pulmonary vascular disease due to portal hypertension that exhibits high morbidity and mortality. The mechanisms driving disease are unknown, and transcriptional characteristics unique to the PoPH liver remain unexplored. Here, we apply single nuclear RNA sequencing to compare cirrhotic livers from patients with and without PoPH. We identify characteristics unique to PoPH in cells surrounding the central hepatic vein, including increased growth differentiation factor signaling, enrichment of the arginine biosynthesis pathway, and differential expression of the bone morphogenic protein type II receptor and estrogen receptor type I genes. These results provide insight into the transcriptomic characteristics of the PoPH liver and mechanisms by which PoPH cellular dysfunction might contribute to pulmonary vascular remodeling., (© 2023. Springer Nature Limited.)

High-dimensional metabolomics analyses may identify convergent and divergent markers, potentially representing aligned or orthogonal disease pathways that underly conditions such as pulmonary arterial hypertension (PAH). Using a comprehensive PAH metabolomics dataset, we applied six different conventional and statistical learning techniques to identify analytes associated with key outcomes and compared the results. We found that certain conventional techniques, such as Bonferroni/FDR correction, prioritized metabolites that tended to be highly intercorrelated. Statistical learning techniques generally agreed with conventional techniques on the top-ranked metabolites, but were also more inclusive of different metabolite groups. In particular, conventional methods prioritized sterol and oxylipin metabolites in relation to idiopathic versus non-idiopathic PAH, whereas statistical learning methods tended to prioritize eicosanoid, bile acid, fatty acid, and fatty acyl ester metabolites. Our findings demonstrate how conventional and statistical learning techniques can offer both concordant or discordant results. In the case of a rare yet morbid condition, such as PAH, convergent metabolites may reflect common pathways to shared disease outcomes whereas divergent metabolites could signal either distinct etiologic mechanisms, different sub-phenotypes, or varying stages of disease progression. Notwithstanding the need to investigate the mechanisms underlying the observed results, our main findings suggest that a multi-method approach to statistical analyses of high-dimensional human metabolomics datasets could effectively broaden the scientific yield from a given study design.

Proteomic analysis of patients with pulmonary arterial hypertension (PAH) has demonstrated significant abnormalities in the insulin-like growth factor axis (IGF). This study proposed to establish associations between a specific binding protein, insulin-like growth factor binding protein 4 (IGFBP4), and PAH severity as well as survival across varying study cohorts. In all cohorts studied, serum IGFBP4 levels were significantly elevated in PAH compared to controls ( p  < 0.0001). IGFBP4 concentration was also highest in the connective tissue-associated PAH (CTD-PAH) and idiopathic PAH subtypes (876 and 784 ng/mL, median, respectively). After adjustment for age and sex, IGFBP4 was significantly associated with worse PAH severity as defined by a decreased 6-min walk distance (6MWD), New York heart association functional class (NYHA-FC), REVEAL 2.0 score and higher right atrial pressures. In longitudinal analysis provided by one of the study cohorts, IGFBP4 was prospectively significantly associated with a shorter 6MWD, worse NYHA-FC classification, and decreased survival. Cox multivariable analysis demonstrated higher serum IGFBP4 as an independent predictor of survival in the overall PAHB cohort. Therefore, this study established that higher circulating IGFBP4 levels were significantly associated with worse PAH severity, decreased survival and disease progression. Dysregulation of IGF metabolism/growth axis may play a significant role in PAH cardio-pulmonary pathobiology., Competing Interests: The authors declare no conflicts of interest., (© 2023 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of the Pulmonary Vascular Research Institute.)

Rationale: Genetic studies suggest that SOX17 (SRY-related HMG-box 17) deficiency increases pulmonary arterial hypertension (PAH) risk. Objectives: On the basis of pathological roles of estrogen and HIF2α (hypoxia-inducible factor 2α) signaling in pulmonary artery endothelial cells (PAECs), we hypothesized that SOX17 is a target of estrogen signaling that promotes mitochondrial function and attenuates PAH development via HIF2α inhibition. Methods: We used metabolic (Seahorse) and promoter luciferase assays in PAECs together with the chronic hypoxia murine model to test the hypothesis. Measurements and Main Results: Sox17 expression was reduced in PAH tissues (rodent models and from patients). Chronic hypoxic pulmonary hypertension was exacerbated by mice with conditional Tie2- Sox17 ( Sox17 EC-/- ) deletion and attenuated by transgenic Tie2- Sox17 overexpression ( Sox17 Tg ). On the basis of untargeted proteomics, metabolism was the top pathway altered by SOX17 deficiency in PAECs. Mechanistically, we found that HIF2α concentrations were increased in the lungs of Sox17 EC-/- and reduced in those from Sox17 Tg mice. Increased SOX17 promoted oxidative phosphorylation and mitochondrial function in PAECs, which were partly attenuated by HIF2α overexpression. Rat lungs in males displayed higher Sox17 expression versus females, suggesting repression by estrogen signaling. Supporting 16α-hydroxyestrone (16αOHE; a pathologic estrogen metabolite)-mediated repression of SOX17 promoter activity, Sox17 Tg mice attenuated 16αOHE-mediated exacerbations of chronic hypoxic pulmonary hypertension. Finally, in adjusted analyses in patients with PAH, we report novel associations between a SOX17 risk variant, rs10103692, and reduced plasma citrate concentrations ( n  = 1,326). Conclusions: Cumulatively, SOX17 promotes mitochondrial bioenergetics and attenuates PAH, in part, via inhibition of HIF2α. 16αOHE mediates PAH development via downregulation of SOX17, linking sexual dimorphism and SOX17 genetics in PAH.

Pulmonary hypertension (PH) is associated with significant morbidity and mortality. RASA3 is a GTPase activating protein integral to angiogenesis and endothelial barrier function. In this study, we explore the association of RASA3 genetic variation with PH risk in patients with sickle cell disease (SCD)-associated PH and pulmonary arterial hypertension (PAH).  Cis -expression quantitative trait loci (eQTL) were queried for RASA3 using whole genome genotype arrays and gene expression profiles derived from peripheral blood mononuclear cells (PBMC) of three SCD cohorts. Genome-wide single nucleotide polymorphisms (SNPs) near or in the RASA3 gene that may associate with lung RASA3 expression were identified, reduced to 9 tagging SNPs for RASA3 and associated with markers of PH. Associations between the top RASA3 SNP and PAH severity were corroborated using data from the PAH Biobank and analyzed based on European or African ancestry (EA, AA). We found that PBMC RASA3 expression was lower in patients with SCD-associated PH as defined by echocardiography and right heart catheterization and was associated with higher mortality. One eQTL for RASA3 (rs9525228) was identified, with the risk allele correlating with PH risk, higher tricuspid regurgitant jet velocity and higher pulmonary vascular resistance in patients with SCD-associated PH. rs9525228 associated with markers of precapillary PH and decreased survival in individuals of EA but not AA. In conclusion, RASA3 is a novel candidate gene in SCD-associated PH and PAH, with RASA3 expression appearing to be protective. Further studies are ongoing to delineate the role of RASA3 in PH., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Background: The prognosis and therapeutic responses are worse for pulmonary arterial hypertension associated with systemic sclerosis (SSc-PAH) compared with idiopathic pulmonary arterial hypertension (IPAH). This discrepancy could be driven by divergence in underlying metabolic determinants of disease., Research Question: Are circulating bioactive metabolites differentially altered in SSc-PAH vs IPAH, and can this alteration explain clinical disparity between these PAH subgroups?, Study Design and Methods: Plasma biosamples from 400 patients with SSc-PAH and 1,082 patients with IPAH were included in the study. Another cohort of 100 patients with scleroderma with no PH and 44 patients with scleroderma with PH was included for external validation. More than 700 bioactive lipid metabolites, representing a range of vasoactive and immune-inflammatory pathways, were assayed in plasma samples from independent discovery and validation cohorts using liquid chromatography/high-resolution mass spectrometry-based approaches. Regression analyses were used to identify metabolites that exhibited differential levels between SSc-PAH and IPAH and associated with disease severity., Results: From hundreds of circulating bioactive lipid molecules, five metabolites were found to distinguish between SSc-PAH and IPAH, as well as associate with markers of disease severity. Relative to IPAH, patients with SSc-PAH carried increased levels of fatty acid metabolites, including lignoceric acid and nervonic acid, as well as eicosanoids/oxylipins and sex hormone metabolites., Interpretation: Patients with SSc-PAH are characterized by an unfavorable bioactive metabolic profile that may explain the poor and limited response to therapy. These data provide important metabolic insights into the molecular heterogeneity underlying differences between subgroups of PAH., (Copyright © 2022 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Variation around the COL18A1 gene, which encodes the angiostatic peptide endostatin, may influence disease heterogeneity in pulmonary arterial hypertension https://bit.ly/3shXrNR., Competing Interests: Conflict of interest: C.E. Simpson reports support for the present manuscript received from NIH/NHLBI grants. Conflict of interest: M. Griffiths reports support for the present manuscript received from NIH/NHLBI grants. Conflict of interest: J. Yang has nothing to disclose. Conflict of interest: M.K. Nies has nothing to disclose. Conflict of interest: D. Vaidya reports receiving grants or contacts outside the submitted work from National Institutes of Health. Conflict of interest: S. Brandal has nothing to disclose. Conflict of interest: L.J. Martin reports support for the present manuscript received from NIH/NHLBI grants. Conflict of interest: M.W. Pauciulo has nothing to disclose. Conflict of interest: K.A. Lutz has nothing to disclose. Conflict of interest: A.W. Coleman has nothing to disclose. Conflict of interest: E.D. Austin reports support for the present manuscript received from NIH/NHLBI grants; and grants or contracts received from CMREF, outside the submitted work. Conflict of interest: D.D. Ivy reports support for the present manuscript received from NIH/NHLBI grants; and consulting fees received from The University of Colorado contracts with Actelion, Altavant, Bayer, and Gossamer Bio, outside the submitted work. Conflict of interest: W.C. Nichols reports support for the present manuscript received from NIH/NHLBI grants. Conflict of interest: A.D. Everett reports support for the present manuscript received from NIH/NHLBI grants. Conflict of interest: P.M. Hassoun reports receiving grants or contacts outside the submitted work from NIH/NHLBI; and he serves on a scientific Advisory Board for MSD, unrelated to the current work. Conflict of interest: R.L. Damico reports support for the present manuscript received from NIH/NHLBI grants., (Copyright ©The authors 2022.)

Rationale: Pulmonary arterial hypertension (PAH) is characterized by structural remodeling of pulmonary arteries and arterioles. Underlying biological processes are likely reflected in a perturbation of circulating proteins. Objectives: To quantify and analyze the plasma proteome of patients with PAH using inherited genetic variation to inform on underlying molecular drivers. Methods: An aptamer-based assay was used to measure plasma proteins in 357 patients with idiopathic or heritable PAH, 103 healthy volunteers, and 23 relatives of patients with PAH. In discovery and replication subgroups, the plasma proteomes of PAH and healthy individuals were compared, and the relationship to transplantation-free survival in PAH was determined. To examine causal relationships to PAH, protein quantitative trait loci (pQTL) that influenced protein levels in the patient population were used as instruments for Mendelian randomization (MR) analysis. Measurements and Main Results: From 4,152 annotated plasma proteins, levels of 208 differed between patients with PAH and healthy subjects, and 49 predicted long-term survival. MR based on cis -pQTL located in proximity to the encoding gene for proteins that were prognostic and distinguished PAH from health estimated an adverse effect for higher levels of netrin-4 (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.16-2.08) and a protective effect for higher levels of thrombospondin-2 (OR, 0.83; 95% CI, 0.74-0.94) on PAH. Both proteins tracked the development of PAH in previously healthy relatives and changes in thrombospondin-2 associated with pulmonary arterial pressure at disease onset. Conclusions: Integrated analysis of the plasma proteome and genome implicates two secreted matrix-binding proteins, netrin-4 and thrombospondin-2, in the pathobiology of PAH.

Background: Inflammation and dysregulated immunity are important in the development of pulmonary arterial hypertension (PAH). Compelling preclinical data supports the therapeutic blockade of interleukin-6 (IL-6) signalling., Methods: We conducted a phase 2 open-label study of intravenous tocilizumab (8 mg·kg -1 ) over 6 months in patients with group 1 PAH. Co-primary end-points were safety, defined by incidence and severity of adverse events, and change in pulmonary vascular resistance. Separately, a mendelian randomisation study was undertaken on 11 744 individuals with European ancestry including 2085 patients with idiopathic/heritable disease for the IL-6 receptor ( IL6R ) variant (rs7529229), known to associate with circulating IL-6R levels., Results: We recruited 29 patients (male/female 10/19; mean±sd age 54.9±11.4 years). Of these, 19 had heritable/idiopathic PAH and 10 had connective tissue disease-associated PAH. Six were withdrawn prior to drug administration; 23 patients received at least one dose of tocilizumab. Tocilizumab was discontinued in four patients owing to serious adverse events. There were no deaths. Despite evidence of target engagement in plasma IL-6 and C-reactive protein levels, both intention-to-treat and modified intention-to-treat analyses demonstrated no change in pulmonary vascular resistance. Inflammatory markers did not predict treatment response. Mendelian randomisation did not support an effect of the lead IL6R variant on risk of PAH (OR 0.99, p=0.88)., Conclusion: Adverse events were consistent with the known safety profile of tocilizumab. Tocilizumab did not show any consistent treatment effect., Competing Interests: Conflict of interest: M. Toshner reports grants and personal fees from Bayer and Actelion, and personal fees from MSD and GSK, during the conduct of the study, and serves on the advisory board for MorphogenIX. Conflict of interest: C. Church has received travel grants and speaker fees from GSK, Actelion and Bayer. Conflict of interest: L. Harbaum has nothing to disclose. Conflict of interest: C. Rhodes reports personal fees for advisory board work from Actelion and United Therapeutics, outside the submitted work. Conflict of interest: S.S. Villar Moreschi has nothing to disclose. Conflict of interest: J. Liley has nothing to disclose. Conflict of interest: R. Jones has nothing to disclose. Conflict of interest: A. Arora has nothing to disclose. Conflict of interest: K. Batai has nothing to disclose. Conflict of interest: A.A. Desai has nothing to disclose. Conflict of interest: J.G. Coghlan reports research support, consultancy fees and speaker honoraria from Actelion. Conflict of interest: J.S.R. Gibbs reports personal fees from Acceleron, Arena, Bayer, Bellepheron, Complexa, Pfizer and United Therapeutics, grants and personal fees from Actelion, and personal fees and non-financial support from GSK, outside the submitted work. Conflict of interest: D. Gor was an employee of Roche, during the conduct of the study. Conflict of interest: S. Gräf has nothing to disclose. Conflict of interest: L. Harlow has nothing to disclose. Conflict of interest: J. Hernandez-Sanchez is an employee of Roche but was not at the time of trial conduct. Conflict of interest: L.S. Howard has received personal fees and institutional grants/research support from Bayer and personal fees from MSD, Daichii Sayo and Pfizer. Conflict of interest: M. Humbert has received personal fees from Actelion, Merck and United Therapeutics, and grants and personal fees from Bayer and GSK. Conflict of interest: J. Karnes has nothing to disclose. Conflict of interest: D.G. Kiely reports grants and personal fees from Bayer and Actelion, and personal fees from GSK and MSD, during the conduct of the study. Conflict of interest: R. Kittles has nothing to disclose. Conflict of interest: E. Knightbridge has nothing to disclose. Conflict of interest: B. Lam has nothing to disclose. Conflict of interest: K.A. Lutz has nothing to disclose. Conflict of interest: W.C. Nichols has nothing to disclose. Conflict of interest: M.W. Pauciulo has nothing to disclose. Conflict of interest: J. Pepke-Zaba has served on advisory boards of and received personal fees and institutional grant/research support from Actelion, Bayer, MSD and GSK. Conflict of interest: J. Suntharalingam has nothing to disclose. Conflict of interest: F. Soubrier has nothing to disclose. Conflict of interest: R.C. Trembath has nothing to disclose. Conflict of interest: T-H.L. Schwantes-An has nothing to disclose. Conflict of interest: S.J. Wort reports grants and personal fees from Actelion and Bayer, and personal fees from GSK and MSD, outside the submitted work. Conflict of interest: M.R. Wilkins has nothing to disclose. Conflict of interest: S. Gaine has received honoraria from Actelion and United Therapeutics; has received travel grants from Actelion, Novartis and Menerini; and has performed drug safety board monitoring for United Therapeutics, GSK and Novartis. Conflict of interest: N.W. Morrell reports personal fees from MorphogenIX, during the conduct of the study. Conflict of interest: P.A. Corris has served on speakers’ bureau and advisory boards of Actelion, Bayer and MSD, and received institutional grant/research support from Actelion and Bayer., (Copyright ©The authors 2022.)

Hepatoma-derived growth factor (HDGF) was previously shown to be associated with increased mortality in a small study of idiopathic and connective tissue disease-associated pulmonary arterial hypertension (PAH). In this study, we measured serum HDGF levels in a large multicenter cohort (total 2017 adult PAH-Biobank enrollees), we analyzed the associations between HDGF levels and various clinical measures using linear or logistic regression models. Higher HDGF levels were found to be significantly associated with worse pulmonary hemodynamics, prostacyclin treatment; among PAH subtypes, higher HDGF levels were most associated with portopulmonary hypertension (beta = 0.469, p  < 0.0001). Both Kaplan-Meier curve and Cox proportional hazard regression demonstrated that higher HDGF levels are associated with a higher risk of mortality (COX hazard ratio 1.31, p  < 0.0001). Further, in the Sugen hypoxia (SuHx) rat model, the highest HDGF levels were post-pulmonary circulation, and HDGF levels significantly increased with the development of PAH. In pulmonary arteries, immunohistochemistry staining showed that HDGF was highly expressed in pulmonary smooth muscle cells in both PAH patients and SuHx rats. In conclusion, we found that higher serum HDGF was linked with increased mortality, and associated with disease severity in a large multi-center adult PAH cohort ( n  = 2017). In the SuHX PAH models, circulating HDGF levels are pulmonary in origin and increase with PAH progression. HDGF may be actively involved in vascular remodeling in PAH., Competing Interests: The authors declare that there are no conflict of interests., (© 2021 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Objective: This study was undertaken to compare the rate of change in cognition between glucocerebrosidase (GBA) mutation carriers and noncarriers with and without subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson disease., Methods: Clinical and genetic data from 12 datasets were examined. Global cognition was assessed using the Mattis Dementia Rating Scale (MDRS). Subjects were examined for mutations in GBA and categorized as GBA carriers with or without DBS (GBA+DBS+, GBA+DBS-), and noncarriers with or without DBS (GBA-DBS+, GBA-DBS-). GBA mutation carriers were subcategorized according to mutation severity (risk variant, mild, severe). Linear mixed modeling was used to compare rate of change in MDRS scores over time among the groups according to GBA and DBS status and then according to GBA severity and DBS status., Results: Data were available for 366 subjects (58 GBA+DBS+, 82 GBA+DBS-, 98 GBA-DBS+, and 128 GBA-DBS- subjects), who were longitudinally followed (range = 36-60 months after surgery). Using the MDRS, GBA+DBS+ subjects declined on average 2.02 points/yr more than GBA-DBS- subjects (95% confidence interval [CI] = -2.35 to -1.69), 1.71 points/yr more than GBA+DBS- subjects (95% CI = -2.14 to -1.28), and 1.49 points/yr more than GBA-DBS+ subjects (95% CI = -1.80 to -1.18)., Interpretation: Although not randomized, this composite analysis suggests that the combined effects of GBA mutations and STN-DBS negatively impact cognition. We advise that DBS candidates be screened for GBA mutations as part of the presurgical decision-making process. We advise that GBA mutation carriers be counseled regarding potential risks associated with STN-DBS so that alternative options may be considered. ANN NEUROL 2022;91:424-435., (© 2022 American Neurological Association.)