Biomarker For Pulmonary Arterial Hypertension Research Articles

Circulating Biomarkers in Pulmonary Arterial Hypertension: An Update.

Pulmonary arterial hypertension (PAH) is a rare subtype of group 1 pulmonary hypertension (PH) diseases, characterized by high pulmonary artery pressure leading to right ventricular dysfunction and potential life-threatening consequences. PAH involves complex mechanisms: vasoconstriction, vascular remodeling, endothelial dysfunction, inflammation, oxidative stress, fibrosis, RV remodeling, cellular hypoxia, metabolic imbalance, and thrombosis. These mechanisms are mediated by several pathways, involving molecules like nitric oxide and prostacyclin. PAH diagnosis requires clinical evaluation and right heart catheterization, confirming a value of mPAP ≥ 20 mmHg at rest and often elevated pulmonary vascular resistance (PVR). Even if an early and accurate diagnosis is crucial, PAH still lacks effective biomarkers to assist in its diagnosis and prognosis. Biomarkers could contribute to arousing clinical suspicion and serve for prognosis prediction, risk stratification, and dynamic monitoring in patients with PAH. The aim of the present review is to report the main novelties on new possible biomarkers for the diagnosis, prognosis, and treatment monitoring of PAH.

Differential expression and analysis of extrachromosomal circular DNAs as serum biomarkers in pulmonary arterial hypertension

BackgroundExtrachromosomal circular DNAs (eccDNAs) have been reported to play a key role in the occurrence and development of various diseases. However, the characterization and role of eccDNAs in pulmonary arterial hypertension (PAH) remain unclear.MethodsIn the discovery cohort, we first explored eccDNA expression profiles by Circle-sequencing analysis. The candidate eccDNAs were validated by routine polymerase chain reaction (PCR), TOPO-TA cloning and Sanger sequencing. In the validation cohort, 30 patients with PAH and 10 healthy controls were recruited for qPCR amplification to detect the candidate eccDNAs. Datas at the baseline were collected, including clinical background, biochemical variables, echocardiography and hemodynamic factors. Receiver operating characteristic curve was used to investigate the diagnostic effect of the eccDNA.ResultsWe identified a total of 21,741 eccDNAs in plasma samples of 3 IPAH patients and 3 individuals in good health, and the expression frequency, GC content, length distribution, and genome distribution of the eccDNAs were thoroughly characterized and analyzed. In the validation cohort, 687 eccDNAs were differentially expressed in patients with IPAH compared with healthy controls (screening threshold: |FC|≥2 and P < 0.05). Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the specific eccDNAs in IPAH were significantly enriched in calcium channel activity, the mitogen-activated protein kinase pathway, and the wnt signaling pathway. Verification queue found that the expression of eccDNA-chr2:131208878–131,424,362 in PAH was considerably higher than that in healthy controls and exhibited a high level of accuracy in predicting PAH with a sensitivity of 86.67% and a specificity of 90%. Furthermore, correlation analysis disclosed a significant association between serum eccDNA-chr2:131208878–131,424,362 and mean pulmonary artery pressure (mPAP) (r = 0.396, P = 0.03), 6 min walking distance (6MWD) (r = -0.399, P = 0.029), N-terminal pro-B-type natriuretic peptide (NT-proBNP) (r = 0.685, P < 0.001) and cardiac index (CI) (r = − 0.419, P = 0.021).ConclusionsThis is the first study to identify and characterize eccDNAs in patients with PAH. We revealed that serum eccDNA-chr2:131208878–131,424,362 is significantly overexpressed and can be used in the diagnosis of PAH, indicating its potential as a novel non-invasive biomarker.

Identification of MACC1 as a potential biomarker for pulmonary arterial hypertension based on bioinformatics and machine learning

BackgroundPulmonary arterial hypertension (PAH) is a life-threatening disease characterized by abnormal early activation of pulmonary arterial smooth muscle cells (PASMCs), yet the underlying mechanisms remain to be elucidated. MethodsNormal and PAH gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database and analyzed using gene set enrichment analysis (GSEA) to uncover the underlying mechanisms. Weighted gene co-expression network analysis (WGCNA) and machine learning methods were deployed to further filter hub genes. A number of immune infiltration analysis methods were applied to explore the immune landscape of PAH. Enzyme-linked immunosorbent assay (ELISA) was employed to compare MACC1 levels between PAH and normal subjects. The important role of MACC1 in the progression of PAH was verified through Western blot and real-time qPCR, among others. Results39 up-regulated and 7 down-regulated genes were identified by ‘limma’ and ‘RRA’ packages. WGCNA and machine learning further narrowed down the list to 4 hub genes, with MACC1 showing strong diagnostic capacity. In vivo and in vitro experiments revealed that MACC1 was highsly associated with malignant features of PASMCs in PAH. ConclusionsThese findings suggest that targeting MACC1 may offer a promising therapeutic strategy for treating PAH, and further clinical studies are warranted to evaluate its efficacy.

Whole-genome microRNA sequencing analysis in patients with pulmonary hypertension.

Pulmonary hypertension (PH) is a pathological disorder with multiple clinical manifestations that lead to cardiovascular and respiratory diseases in most patients. Recent studies have revealed that microRNAs (miRNAs) play important roles as upstream signaling molecules in several diseases, including PH. However, miRNAs that can be used as diagnostic or prognostic biomarkers for PH have not been identified. Thus, in this study, peripheral blood samples obtained from patients with PH and healthy individuals were subjected to genome-wide miRNA sequencing and transcriptome analysis. We screened 136 differentially expressed miRNAs in patients with PH and verified that four differentially expressed miRNAs, namely, hsa-miR-1304-3p, hsa-miR-490-3p, hsa-miR-11400, and hsa-miR-31-5p, could be used as clinical diagnostic biomarkers for pulmonary arterial hypertension. Our findings provide a basis for further in-depth investigations of the specific mechanisms of miRNAs in PH.

RNA ve protein seviyelerinde temel biyobelirteçleri belirlemek için pulmoner arteriyel hipertansiyonun in silico analizi

Pulmonary arterial hypertension (PAH) is a chronic cardiopulmonary disorder marked by a raised hypertension in the pulmonary arteries. There is no remedy for PAH, existing medications can help reduce the disease’s progression. This research aimed to investigate potential protein and RNA biomarkers of PAH by bioinformatic analysis. Two PAH datasets accessed from the publicly available Gene Expression Omnibus (GEO) database were used to discover differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses for common DEGs were conducted by the DAVID tool. Cytoscape was used to create the protein-protein interaction (PPI) and pick the top 10 hub genes. The transcription factors (TFs) and microRNAs (miRNAs) that target DEGs and hub genes were investigated using the JASPAR database. Potential therapeutics that target the top hub genes have been discovered. Ten hub genes were discovered to be linked to the pathogenesis of PAH (CCL5, TLR4, TLR1, SPP1, CYBB, HGF, IGF1, SELL, CD163, and POSTN). “Positive regulation of tumor necrosis factor biosynthetic process” and a “toll-like receptor signaling pathway” are the most enriched GO term and KEGG pathway, respectively. “hsa-mir-26b-5p, hsa-mir-146a-5p, hsa-mir-335-5p” and FOXC1, YY1, GATA2 are the top TFs targeting hub genes. 21 drugs targeting ten hub genes have been discovered. Our results would help to discover the pathogenesis of PAH and hub genes, miRNAs and 10 TFs that might serve as potential therapeutic targets at protein and RNA levels for PAH patients.

Kynurenine pathway metabolism evolves with development of preclinical and scleroderma-associated pulmonary arterial hypertension.

Understanding metabolic evolution underlying pulmonary arterial hypertension (PAH) development may clarify pathobiology and reveal disease-specific biomarkers. Patients with systemic sclerosis (SSc) are regularly surveilled for PAH, presenting an opportunity to examine metabolic change as disease develops in an at-risk cohort. We performed mass spectrometry-based metabolomics on longitudinal serum samples collected before and near SSc-PAH diagnosis, compared with time-matched SSc subjects without PAH, in a SSc surveillance cohort. We validated metabolic differences in a second cohort and determined metabolite-phenotype relationships. In parallel, we performed serial metabolomic and hemodynamic assessments as the disease developed in a preclinical model. For differentially expressed metabolites, we investigated corresponding gene expression in human and rodent PAH lungs. Kynurenine and its ratio to tryptophan (kyn/trp) increased over the surveillance period in patients with SSc who developed PAH. Higher kyn/trp measured two years before diagnostic right heart catheterization increased the odds of SSc-PAH diagnosis (OR 1.57, 95% CI 1.05-2.36, P = 0.028). The slope of kyn/trp rise during SSc surveillance predicted PAH development and mortality. In both clinical and experimental PAH, higher kynurenine pathway metabolites correlated with adverse pulmonary vascular and RV measurements. In human and rodent PAH lungs, expression of TDO2, which encodes tryptophan 2,3 dioxygenase (TDO), a protein that catalyzes tryptophan conversion to kynurenine, was significantly upregulated and tightly correlated with pulmonary hypertensive features. Upregulated kynurenine pathway metabolism occurs early in PAH, localizes to the lung, and may be modulated by TDO2. Kynurenine pathway metabolites may be candidate PAH biomarkers and TDO warrants exploration as a potential novel therapeutic target.NEW & NOTEWORTHY Our study shows an early increase in kynurenine pathway metabolism in at-risk subjects with systemic sclerosis who develop pulmonary arterial hypertension (PAH). We show that kynurenine pathway upregulation precedes clinical diagnosis and that this metabolic shift is associated with increased disease severity and shorter survival times. We also show that gene expression of TDO2, an enzyme that generates kynurenine from tryptophan, rises with PAH development.

In the Search for Biomarkers of Pulmonary Arterial Hypertension, Are Cytokines IL-2, IL-4, IL-6, IL-10, and IFN-Gamma the Right Indicators to Use?

Pulmonary arterial hypertension (PAH) is a complex disorder characterized by increased pressure in the pulmonary arteries, leading to right heart failure. While the exact mechanisms underlying PAH are not fully understood, cytokines have been implicated in the pathogenesis of the disease. Cytokines play a crucial role in regulating immune responses and inflammation. These small proteins also play a key role in shaping the immunophenotype, which refers to the specific characteristics and functional properties of immune cells, which can have a significant impact on the development of PAH. The aim of this study was to determine the immunophenotype and the concentration of selected cytokines, IL-2, IL-4, IL-6, IL-10, and IFN-gamma, in patients diagnosed with PAH (with particular emphasis on subtypes) in relation to healthy volunteers. Based on the obtained results, we can conclude that in patients with PAH, the functioning of the immune system is deregulated as a result of a decrease in the percentage of selected subpopulations of immune cells in peripheral blood and changes in the concentration of tested cytokines in relation to healthy volunteers. In addition, a detailed analysis showed that there are statistically significant differences between the PAH subtypes and the tested immunological parameters. This may indicate a significant role of the immune system in the pathogenesis of PAH.

0449 Unbiased Examination of Metabolomic Signatures in Sleep Disordered Breathing and Group 1 PAH in the (PVDOMICS) Cohort

Abstract Introduction Metabolic alterations have been identified as a novel driver of pulmonary arterial hypertension (PAH) pathogenesis. Sleep disordered breathing (SDB), characterized by intermittent hypoxemic episodes, has also been implicated in PAH, particularly when associated with more profound degrees of hypoxia, and metabolic dysfunction. We hypothesize to observe in SDB and PAH in humans a similar pattern of metabolic alterations as previously described in animal models of PAH. Methods Pulmonary Vascular Disease Phenomics (PVDOMICS,NCT02980887), a multicenter study, was designed in part to elucidate molecular signatures in PH. We analyzed data from Group 1 PAH participants who underwent home sleep apnea testing with circulating plasma metabolomic measures (Metabolon). We conducted an unbiased analysis of SDB measures: apnea-hypopnea index (AHI, 3% oxygen desaturation hypopnea definition) and % recording time&amp;lt; 90% SpO2 (TRT&amp;lt; 90%), with metabolites (954 after qc filtering) using a flexible and robust semi-parametric proportional hazards model adjusted for age, sex, body mass index (BMI), diabetes mellitus (DM), race and study site. Metabolites with False discovery rate (FDR) adjusted p-values &amp;lt; 0.1 were called significant. Closed-set testing with the Simes method and Metabolon provided annotations (90 sets) was used to test metabolite sets. Results The cohort (n=175) was 72% female, 81% White and 16% DM with (1st Quartile/Median/3rd Quartile) Age: 42/54/63 years, BMI: 24.6/29.1/34.1 kg/m2, AHI: 0.9/4.3/12.6 and TRT&amp;lt; 90%: 2.3/37/87.4. 21 metabolites showed significant association with TRT&amp;lt; 90% (8 with positive direction/13 negative) and 0 with AHI. Among metabolite sets, Pregnenolone steroids had the strongest association with TRT&amp;lt; 90% (6 members; adjusted p=0.038; True Discovery Proportion (TDP)=0.33) followed by Fatty Acid Metabolism (Acyl Choline) (7 members; adjusted p-value=0.046; TDP=0.71) and Polyamine Metabolism (7 members; adjusted p-value p=0.054; TDP=0.14). Conclusion Three primary metabolite pathways were associated with sleep-related hypoxia in Group 1 PAH. Polyamine metabolism and fatty acid metabolism changes have previously been observed in a rat PAH model, consistent with our findings. Findings specific to metabolic biomarkers in SDB and PAH are novel and may lead to insights that broaden our understanding of PAH pathobiology and potential therapeutic targets. Support (if any)

Serum and Pulmonary Expression Profiles of the Activin Signaling System in Pulmonary Arterial Hypertension.

Activins are novel therapeutic targets in pulmonary arterial hypertension (PAH). We therefore studied whether key members of the activin pathway could be used as PAH biomarkers. Serum levels of activin A, activin B, α-subunit of inhibin A and B proteins, and the antagonists follistatin and follistatin-like 3 (FSTL3) were measured in controls and in patients with newly diagnosed idiopathic, heritable, or anorexigen-associated PAH (n=80) at baseline and 3 to 4 months after treatment initiation. The primary outcome was death or lung transplantation. Expression patterns of the inhibin subunits, follistatin, FSTL3, Bambi, Cripto, and the activin receptors type I (ALK), type II (ACTRII), and betaglycan were analyzed in PAH and control lung tissues. Death or lung transplantation occurred in 26 of 80 patients (32.5%) over a median follow-up of 69 (interquartile range, 50-81) months. Both baseline (hazard ratio, 1.001 [95% CI, 1.000-1.001]; P=0.037 and 1.263 [95% CI, 1.049-1.520]; P=0.014, respectively) and follow-up (hazard ratio, 1.003 [95% CI, 1.001-1.005]; P=0.001 and 1.365 [95% CI, 1.185-1.573]; P<0.001, respectively) serum levels of activin A and FSTL3 were associated with transplant-free survival in a model adjusted for age and sex. Thresholds determined by receiver operating characteristic analyses were 393 pg/mL for activin A and 16.6 ng/mL for FSTL3. When adjusted with New York Heart Association functional class, 6-minute walk distance, and N-terminal pro-B-type natriuretic peptide, the hazard ratios for transplant-free survival for baseline activin A <393 pg/mL and FSTL3 <16.6 ng/mL were, respectively, 0.14 (95% CI, 0.03-0.61; P=0.009) and 0.17 (95% CI, 0.06-0.45; P<0.001), and for follow-up measures, 0.23 (95% CI, 0.07-0.78; P=0.019) and 0.27 (95% CI, 0.09-0.78, P=0.015), respectively. Prognostic values of activin A and FSTL3 were confirmed in an independent external validation cohort. Histological analyses showed a nuclear accumulation of the phosphorylated form of Smad2/3, higher immunoreactivities for ACTRIIB, ALK2, ALK4, ALK5, ALK7, Cripto, and FSTL3 in vascular endothelial and smooth muscle layers, and lower immunostaining for inhibin-α and follistatin. These findings offer new insights into the activin signaling system in PAH and show that activin A and FSTL3 are prognostic biomarkers for PAH.

Insulin‐like growth factor binding protein‐4: The quest for the breakthrough biomarker in pulmonary arterial hypertension

Insulin‐like growth factor binding protein‐4: The quest for the breakthrough biomarker in pulmonary arterial hypertension

Plasma Connective Tissue Growth Factor as a Biomarker of Pulmonary Arterial Hypertension Associated With Congenital Heart Disease in Adults.

Connective tissue growth factor (CTGF) has diagnostic value for pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD) in children; however, its value in adult patients remains unclear. This study evaluated CTGF as a biomarker in adult PAH-CHD patients.Methods and Results: Based on mean pulmonary artery pressure (mPAP), 56 CHD patients were divided into 3 groups: without PAH (W; mPAP <25 mmHg; n=28); mild PAH (M; mPAP 25-35 mmHg; n=18); and moderate and severe PAH (H; mPAP ≥35 mmHg; n=10). The control group consisted of 28 healthy adults. Plasma CTGF and B-type natriuretic peptide (BNP) concentrations were determined. Plasma CTGF concentrations were higher in the H and M groups than in the W and control groups, and were higher in the H than M group. Plasma CTGF concentrations were positively correlated with pulmonary artery systolic pressure (PASP), mPAP, and pulmonary vascular resistance, and negatively correlated with mixed venous oxygen saturation. CTGF, BNP, red blood cell distribution width, and World Health Organization Class III/IV were risk factors for PAH in CHD patients, and CTGF was an independent risk factor for PAH-CHD. The efficacy of CTGF in the diagnosis of PAH was not inferior to that of BNP. CTGF is a biomarker of PAH associated with CHD. It can be used for early diagnosis and severity assessment in adult patients with CHD-PAH.

Hemosiderin-laden macrophages in bronchoalveolar lavage samples of children with bronchopulmonary dysplasia.

To evaluate the prevalence of hemosiderin-laden macrophages in children with bronchopulmonary dysplasia (BPD) and assess for an association between hemosiderin-laden macrophages and pulmonary arterial hypertension. Retrospective case-control study of infants and children with and without BPD who underwent bronchoscopy with bronchoalveolar lavage (BAL) the at Children's Hospital of Philadelphia between 2012 and2021. BAL from 205 children with BPD and 106 controls without BPD matched for tracheostomy, infection, and age were reviewed for hemosiderin-laden macrophages. Seventy-one individuals (34.6%) with BPD had a BAL with 10% or more hemosiderin-laden macrophages compared with 3 (2.8%) controls (P<.0001; OR, 18.19; 95% CI, 5.57-59.41). Patients with pulmonary hypertension by echocardiogram (P=.04; OR, 3.69; 95% CI, 1.05-12.96) or an elevated mean pulmonary artery pressure during cardiac catheterization, rs (14)=0.56, P=.04, were more likely to have elevated hemosiderin-laden macrophages on BAL samples less than 60days from bronchoscopy. After adjusting for birth weight, gestational age, BPD grade, and age at the time of bronchoscopy using logistic regression, pulmonary hypertension was associated with a higher odds of hemosiderin-laden macrophages of 10% or more (P=.02; OR, 6.37; 95% CI, 1.28-31.87). No association was observed between hemosiderin-laden macrophages and sex, race, gestational age, birth weight, tracheostomy, or infectious studies. This retrospective study revealed increased hemosiderin-laden macrophages in BAL samples from patients with BPD and a significant association with pulmonary arterial hypertension. It is unclear whether elevated hemosiderin-laden macrophages within BPD contributes to the pathogenesis of lung and pulmonary vascular disease or is simply a biomarker of pulmonary arterial hypertension.

Multi-Task Learning for Pulmonary Arterial Hypertension Prognosis Prediction Via Memory Drift and Prior Prompt Learning on 3D Chest CT.

Pulmonary arterial hypertension (PAH) prognosis prediction on 3D non-contrast CT images is one of the most important tasks for PAH treatment. It will help clinicians stratify patients into different groups for early diagnosis and timely intervention via automatically extracting the potential biomarkers of PAH to predict mortality. However, it is still a task of great challenges due to the large volume and low-contrast regions of interest in 3D chest CT images. In this paper, we propose the first multi-task learning-based PAH prognosis prediction framework, P 2-Net, which effectively optimizes the model and powerfully represents task-dependent features via our Memory Drift (MD) and Prior Prompt Learning (PPL) strategies. 1) Our MD maintains a large memory bank to provide a dense sampling of the deep biomarkers' distribution. Therefore, although the batch size is very small caused by our large volume, a reliable (negative log partial) likelihood loss is still able to be calculated on a representative probability distribution for robust optimization. 2) Our PPL simultaneously learns an additional manual biomarkers prediction task to embed clinical prior knowledge into our deep prognosis prediction task in hidden and explicit ways. Therefore, it will prompt the prediction of deep biomarkers and improve the perception of task-dependent features in our low-contrast regions. Our P 2-Net achieves a high prognostic correlation of the prediction and great generalization with the highest 70.19% C-index and 2.14 HR. Extensive experiments with promising results on our PAH prognosis prediction reveal powerful prognosis performance and great clinical significance in PAH treatment. All of our code will be made publicly available online Opened source: https://github.com/YutingHe-list/P2-Net.

Exhaled Air Metabolome Analysis for Pulmonary Arterial Hypertension Fingerprints Identification—The Preliminary Study

Pulmonary arterial hypertension (PAH) is a rare disease with a serious prognosis. The aim of this study was to identify biomarkers for PAH in the breath phase and to prepare an automatic classification method to determine the changing metabolome trends and molecular mapping. A group of 37 patients (F/M: 8/29 women, mean age 60.4 ± 10.9 years, BMI 27.6 ± 6.0 kg/m2) with diagnosed PAH were enrolled in the study. The breath phase of all the patients was collected on a highly porous septic material using a special patented holder PL230578, OHIM 002890789-0001. The collected air was then examined with gas chromatography coupled with mass spectrometry (GC/MS). The algorithms of Spectral Clustering, KMeans, DBSCAN, and hierarchical clustering methods were used to perform the cluster analysis. The identification of the changes in the ratio of the whole spectra of biomarkers allowed us to obtain a multidimensional pathway for PAH characteristics and showed the metabolome differences in the four subgroups divided by the cluster analysis. The use of GC/MS, supported with novel porous polymeric materials, for the breath phase analysis seems to be a useful tool in selecting bio-fingerprints in patients with PAH. The four metabolome classes which were obtained constitute novel data in the PAH population.

Cytokines as prognostic biomarkers in pulmonary arterial hypertension.

Risk stratification and assessment of disease progression in patients with pulmonary arterial hypertension (PAH) are challenged by the lack of accurate disease-specific and prognostic biomarkers. To date, brain natriuretic peptide (BNP) and/or its N-terminal fragment (NT-proBNP) are the only markers for right ventricular dysfunction used in clinical practice, in association with echocardiographic and invasive haemodynamic variables to predict outcome in patients with PAH. This study was designed to identify an easily measurable biomarker panel in the serum of 80 well-phenotyped PAH patients with idiopathic, heritable or drug-induced PAH at baseline and at first follow-up. The prognostic value of identified cytokines of interest was secondly analysed in an external validation cohort of 125 PAH patients. Among the 20 biomarkers studied with the multiplex Ella platform, we identified a three-biomarker panel composed of β-NGF, CXCL9 and TRAIL that were independently associated with prognosis both at the time of PAH diagnosis and at the first follow-up after initiation of PAH therapy. β-NGF and CXCL9 were predictors of death or transplantation, whereas high levels of TRAIL were associated with a better prognosis. Furthermore, the prognostic value of the three cytokines was more powerful for predicting survival than usual non-invasive variables (New York Heart Association Functional Class, 6-min walk distance and BNP/NT-proBNP). The results were validated in a fully independent external validation cohort. The monitoring of β-NGF, CXCL9 and TRAIL levels in serum should be considered in the management and treatment of patients with PAH to objectively guide therapeutic options.

Identification of JPX-RABEP1 Pair as an Immune-Related Biomarker and Therapeutic Target in Pulmonary Arterial Hypertension by Bioinformatics and Experimental Analyses

Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease characterized by pulmonary vascular remodeling and right heart enlargement the pathogenesis of PAH is complicated; no biologic-based therapy is available for the treatment of PAH, but recent studies suggest that inflammatory response and abnormal proliferation of pulmonary artery smooth muscle cells are the main pathogenic mechanism, while the role of immune-related long non-coding RNAs (lncRNAs) remains unclear. The aim of this study was to systematically analyze immune-related lncRNAs in PAH. Here, we downloaded a publicly available microarray data from PAH and control patients (GSE113439). A total of 243 up-regulated and 203 down-regulated differentially expressed genes (DEGs) were screened, and immune-related DEGs were further obtained from ImmPort. The immune-related lncRNAs were obtained by co-expression analysis of immune-related mRNAs. Then, immune-related lncRNAs-mRNAs network including 2 lncRNAs and 6 mRNAs was constructed which share regulatory miRNAs and have significant correlation. Among the lncRNA-mRNA pairs, one pair (JPX-RABEP1) was verified in the validating dataset GSE53408 and PAH mouse model. Furthermore, the immune cell infiltration analysis of the GSE113439 dataset revealed that the JPX-RABEP1 pair may participate in the occurrence and development of PAH through immune cell infiltration. Together, our findings reveal that the lncRNA-mRNA pair JPX-RABEP1 may be a novel biomarker and therapeutic target for PAH.

Biomarkers in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a severe medical condition characterized by elevated pulmonary vascular resistance (PVR), right ventricular (RV) failure, and death in the absence of appropriate treatment. The progression and prognosis are strictly related to the etiology, biochemical parameters, and treatment response. The gold-standard test remains right-sided heart catheterization, but dynamic monitoring of systolic pressure in the pulmonary artery is performed using echocardiography. However, simple and easily accessible non-invasive assays are also required in order to monitor this pathology. In addition, research in this area is in continuous development. In recent years, more and more biomarkers have been studied and included in clinical guidelines. These biomarkers can be categorized based on their associations with inflammation, endothelial cell dysfunction, cardiac fibrosis, oxidative stress, and metabolic disorders. Moreover, biomarkers can be easily detected in blood and urine and correlated with disease severity, playing an important role in diagnosis, prognosis, and disease progression.

Retracted: Prognostic Role of Biomarkers for Pulmonary Arterial Hypertension Associated with Bronchopulmonary Dysplasia in Extremely Premature Infants.

[This retracts the article DOI: 10.1155/2022/3914818.].

Abstract 15564: Transcriptional Profiling Unveils New Molecular Subgroups of Adaptive and Maladaptive Right Ventricular Remodeling in Pulmonary Hypertension

The right ventricle (RV) function plays a crucial role in the prognosis and functional outcome of PAH (Pulmonary Arterial Hypertension) patients. However, RV remodeling and its underlying mechanisms in PAH, and the molecular phenotype of RV in different disease conditions are poorly understood. Therefore, we designed this study to deeply investigate molecular changes underlying right ventricular remodeling and dysfunction in PAH. To this aim, we generated RNA-seq data from 40 patients' RV tissues, clinically classified in adaptive versus maladaptive RV hypertrophy. Using an unsupervised clustering-based analysis, we identified “early” and “late” subgroups in both diseased RV states, associated with patients’ hemodynamic profiles. We then demonstrated that the compensated RV is characterized by an upregulation of cell cycle-associated genes and mitochondrial respiration, whereas excessive levels of extracellular matrix components were central in the decompensation phase. However, dysregulation of fatty acid β-oxidation characterized the early decompensation phase. Furthermore, a comparative analysis from 30 RV samples of monocrotaline (MCT)-induced rat model largely confirmed the stage-specific molecular phenotypes, along with subgroups identification. Finally, we assessed the circulating levels of several dysregulated proteins in two independent cohorts of PAH patients and introduced a panel of five ECM-related proteins that had a significant alteration in patients with compensated vs. decompensated RV in both cohorts. Among those, NID1, C1QTNF1, and CRTAC1 demonstrated higher importance in predicting the development of maladaptive RV hypertrophy in both cohorts, while the correlation of their expression with cardiac functions confirmed their potential biomarker capacity in the prognosis of PAH-associated RV hypertrophy and failure. In conclusion, this comprehensive transcriptome study revealed new subgroups of human RV hypertrophy beyond the clinical measurements, while combination with proteome analysis proposed a panel of potential PAH biomarkers related to patients' RV function. Furthermore, our comparative analysis of two species supports the relevance of current animal models to explore new targets.

Biomarker-based approach to determine etiology and severity of pulmonary hypertension: Focus on microRNA.

Pulmonary arterial hypertension (PAH) is characterized by remodeling of the pulmonary arteries, and defined by elevated pulmonary arterial pressure, measured during right heart catheterization. There are three main challenges to the diagnostic and therapeutic process of patients with PAH. First, it is difficult to differentiate particular PAH etiology. Second, invasive diagnostic is required to precisely determine the severity of PAH, and thus to qualify patients for an appropriate treatment. Third, the results of treatment of PAH are unpredictable and remain unsatisfactory. MicroRNAs (miRNAs) are small non-coding RNAs that regulate post transcriptional gene-expression. Their role as a prognostic, and diagnostic biomarkers in many different diseases have been studied in recent years. MiRNAs are promising novel biomarkers in PAH due to their activity in various molecular pathways and processes underlying PAH. Lack of biomarkers to differentiate between particular PAH etiology and evaluate the severity of PAH, as well as paucity of therapeutic targets in PAH open a new field for the possibility to use miRNAs in these applications. In our article, we discuss the potential of miRNAs use as diagnostic tools, prognostic biomarkers and therapeutic targets in PAH.