Eosinophils protect against pulmonary hypertension through 14-HDHA and 17-HDHA

Association of echocardiographic pulmonary hypertension with all-cause mortality in hospitalized AECOPD patients

Background

Chronic obstructive pulmonary disease (COPD) often coexists with pulmonary hypertension (PH). However, whether pulmonary artery pressure (PAP) or even suspected PH assessed by echocardiography during acute exacerbation stage predicts mortality after discharge is unclear.

Methods

We conducted an retrospective study of hospitalized patients with acute exacerbation of COPD (AECOPD). Peak tricuspid regurgitation velocity (TRV) and additional variables were used to assess PH risk.

Results

Cox regression analysis showed that echocardiographic suspected PH was the independent risk factor for the significantly increased long-term mortality (adjusted HR 1.64; 95% CI 1.06-2.53) after discharge in AECOPD patients. Logistic regression analysis revealed a negative correlation between blood eosinophil (EOS) counts at admission and the prevalence of suspected PH (adjusted OR 0.18; 95% CI 0.04-0.89). Triple therapy (adjusted HR 0.18; 95% CI 0.05-0.61), neither LABA/ICS during stable stage was associated with a significant reduction in long-term mortality in hospitalized AECOPD patients with suspected PH.

Conclusion

Echocardiographic suspected PH was associated with adverse survival in hospitalized AECOPD patients. Low EOS counts at admission emerged as a potential biomarker for elevated estimated systolic PAP. Triple therapy during stable stage was associated with a significant reduction in long-term mortality in AECOPD patients with suspected PH.

Deciphering the transcriptomic landscape of systemic lupus erythematosus-associated pulmonary arterial hypertension

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease that involves multi-organ damage. Pulmonary arterial hypertension (PAH) is one of the life-threatening complications of SLE. The underlying cause of systemic lupus erythematosus-associated pulmonary arterial hypertension has not been fully comprehended. Besides the mechanisms implicated in the development of PAH, such as damage to the endothelial cells, the aberrant activation of the immune system also plays a substantial role in the pathogenesis of SLE-PAH.

METHODS

In this study, peripheral blood samples from 100 patients with SLE-PAH and 95 patients of SLE without PAH (SLE-nonPAH) were obtained for RNA sequencing and comprehensive transcriptomic analysis. Pathway enrichment analysis was performed based on differentially expressed genes (DEGs) between SLE-PAH and SLE-nonPAH to elucidate the mechanisms potentially driving the development of PAH in SLE patients. Utilizing consensus non-negative matrix factorization (cNMF), we also conducted a detailed analysis to identify distinct subgroups within the SLE-PAH population. Meanwhile, the protein-protein interaction (PPI) analysis was performed and hub genes among the SLE-PAH subgroups were detected. Common transcription factors (TFs) of detected hub genes were also discovered to serve as potential therapeutic targets.

RESULTS

Inflammatory signaling pathways, notably those involving interferon and TNFα, were found to play an important role in the SLE-PAH. Utilizing cNMF method, three unique subgroups of SLE-PAH patients were delineated, each characterized by a distinct level of inflammatory activity. Specifically, the high inflammation subgroup, marked by the activity of Interleukin-6 (IL-6), exhibited a milder form of PAH. In contrast, the subgroup with moderate inflammation displayed the most pronounced PAH symptoms. Further disease enrichment analysis revealed that, beyond the dysregulated inflammatory pathways, patients with the most severe PAH exhibited distinct pathogenic transcriptomic profiles that disrupted vascular smooth muscle homeostasis, a critical component of vascular health. In the most severely affected subgroup, 13 hub genes were identified. Additionally, two transcription factors commonly associated with these genes, KLF1 and GATA1, were discovered, which may serve as potential therapeutic targets.

CONCLUSION

Our investigation establishes inflammation as a key driver in the development of SLE-PAH. Patients who presented with concurrent dysregulations in inflammatory responses along with PAH-specific pathogenic markers exhibited a marked increase in the severity of their PAH. The insights gleaned from our transcriptomic analysis reveal the intricate interplay between inflammatory mechanisms and the molecular substrates of PAH. This nuanced understanding paves the way for more targeted and effective therapeutic approaches for SLE-PAH.

Quantitative CT imaging characteristics of patients with chronic obstructive pulmonary disease with different eosinophil levels: a retrospective observational study using linked data from a tertiary hospital in China

OBJECTIVE

To investigate the relationship between eosinophil (EOS) and CT imaging, we quantitatively evaluated the bronchial wall thickening, emphysema index (EI) and pulmonary vascular parameters in patients with chronic obstructive pulmonary disease (COPD) based on different EOS levels.

DESIGN

Retrospective observational study.

SETTING

A tertiary hospital in China.

PARTICIPANTS

448 patients with COPD from January 2020 to January 2023.

MAIN OUTCOME MEASURES

Laboratory data, chest CT and pulmonary function based on different EOS levels: <150/µL, ≥150/µL; <100/µL, 100-300/µL, ≥300/µL; <2%, ≥2%.

RESULTS

We evaluated the records of 448 patients diagnosed with COPD. The prevalence of eosinophilia with EOS ≥2% was 41.1% (184 cases), 33.7% (151 cases) with EOS ≥150/µL and 9.4% (42 cases) with EOS ≥300/µL. A lower EOS (EOS <2% or EOS <150/µL) was associated with chronic pulmonary heart disease. The neutrophil count and percentage were significantly higher in the relatively lower EOS group (EOS <2%, EOS <150/µL or EOS <100/µL). When the groups were divided based on the two cut-off values of 2% of EOS percentage and 150/µL of absolute EOS value, no statistical significance was observed for the entire lung, left lung, right lung, lung lobe volume, lung index (EI), and lung emphysema heterogeneity index (HI). However, compared with the 100-300/µL group, the EI of the right upper lobe of the lung was lower in the EOS ≥300/µL group (0.32 vs 0.37, p<0.05). Airway wall thickness, wall area percentage and Pi10 in the EOS ≥2%, EOS ≥150/µL and 100-300/µL groups were lower than those in the EOS <2%, EOS <150/µL and EOS <100/µL groups, respectively. Compared with the EOS <100/µL group, Pi10 in the EOS ≥300/µL group was lower. According to the different cut-off values, such as percentage and absolute value of EOS, there was no significant difference in pulmonary vascular parameters, such as in cross-sectional area less than 5 mm2 (BV5), total blood volume (TBV), BV5/TBV, network length, branchpoints and endpoints (p>0.05 for both). The per cent predicted diffusing lung capacity for carbon monoxide (DLCO%) of the EOS ≥2% group was higher than that of the EOS <2% group. Compared with patients with blood EOS <150/µL, patients with blood EOS ≥150/µL had lower residual volume and lung volume ratio and higher values for per cent predicted forced vital capacity and DLCO%. The values for per cent predicted forced expiratory volume in 1 s, maximal expiratory flow at 75%/50%/25% of lung volume (MEF75%,MEF50%, MEF25%) and DLCO% in the EOS ≥300/µL group were higher than those in the EOS <100/µL group and in the 100-300/µL group.

CONCLUSIONS

Hypereosinophilic COPD (EOS ≥2% or EOS ≥150/µL or EOS ≥300/µL) appears to have less bronchial thickening and better lung function. Notably, in patients with EOS ≥300/µL, the EI of the right upper lobe is reduced. These findings provide valuable insights into the role of EOS in COPD pathophysiology.

Differentiation of lung tissue-resident c-Kit+ cells into microvascular endothelial cells alleviates pulmonary vascular remodeling

Pulmonary vascular remodeling (PVR), encompassing microvascular loss and muscularization, contributes to multiple respiratory diseases. c-Kit+ cells exhibit differentiation potential into both endothelial cells (ECs) and smooth muscle cells. The potential role of lung c-Kit+ cell differentiation in PVR, however, remains unclear. Lung c-Kit+ cells increase in pulmonary hypertension patients and in the SU5416/hypoxia (SuHx)-induced PVR mouse model. Employing genetic lineage tracing and single-cell RNA sequencing (scRNA-seq), we elucidate that lung-resident c-Kit+ cells display an aerocyte and venular endothelial differentiation in the SuHx model. Ablation of tissue-resident c-Kit+ cells exacerbates PVR. We identify an Nr2f2-expressing c-Kit+ cell subgroup, which exhibitsvenous EC differentiation and increases during PVR. Notably, the elevation of Nr2f2 in c-Kit+ cells via AAV enhances differentiation and mitigates PVR. These findings underscore the protective role of lung tissue-resident c-Kit+ cells in PVR, achieved by differentiating into mature ECs. Targeting NR2F2 expression in c-Kit+ cells emerges as a promising strategy for reversing PVR.

Associations between omega-3 fatty acid-derived lipid mediators and markers of inflammation in older subjects with low-grade chronic inflammation

Cardiovascular disease (CVD), the leading cause of death in the United States and globally, is a chronic inflammatory disease likely caused by an impaired ability to resolve inflammation. Pre-clinical studies have provided strong evidence of the activating role of specialized pro-resolving lipid mediators (SPMs) derived from the omega-3 fatty acids eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) on the resolution of inflammation. However, there is a dearth of information on the role of SPMs on inflammation in humans. Therefore, the aim of this study was to assess whether plasma concentrations of omega-3 fatty acids and their derived SPMs are associated with inflammatory markers in subjects with low-grade chronic inflammation (C-reactive protein >2 µg/mL). The plasma phospholipid content of omega-3 fatty acids, a marker of dietary intake, plasma concentrations of SPMs, and serum concentrations of inflammatory markers were measured in 21 older men and postmenopausal women (age 53-73 y) at the end of a four-week placebo phase (3 g/day high oleic acid sunflower oil). The phospholipid DHA content was inversely related to interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and IL-10 concentrations. Moreover, MCP-1 was inversely associated with the DHA-derived 14-HDHA and 4-HDHA, and IL-10 was inversely associated with EPA-derived 18-HEPE, 12-HEPE and 5-HEPE, DPA-derived Rv5DPA, and DHA-derived 4-HDHA. These findings support the anti-inflammatory effect of dietary omega-3 fatty and suggest that lipid mediators derived from EPA, DPA, and DHA participate in the regulation of inflammation in subjects with chronic inflammation.

Ellagic acid-enhanced biocompatibility and bioactivity in multilayer core-shell gold nanoparticles for ameliorating myocardial infarction injury

BACKGROUND

Myocardial infarction (MI) is the main contributor to most cardiovascular diseases (CVDs), and the available post-treatment clinical therapeutic options are limited. The development of nanoscale drug delivery systems carrying natural small molecules provides biotherapies that could potentially offer new treatments for reactive oxygen species (ROS)-induced damage in MI. Considering the stability and reduced toxicity of gold-phenolic core-shell nanoparticles, this study aims to develop ellagic acid-functionalized gold nanoparticles (EA-AuNPs) to overcome these limitations.

RESULTS

We have successfully synthesized EA-AuNPs with enhanced biocompatibility and bioactivity. These core-shell gold nanoparticles exhibit excellent ROS-scavenging activity and high dispersion. The results from a label-free imaging method on optically transparent zebrafish larvae models and micro-CT imaging in mice indicated that EA-AuNPs enable a favorable excretion-based metabolism without overburdening other organs. EA-AuNPs were subsequently applied in cellular oxidative stress models and MI mouse models. We found that they effectively inhibit the expression of apoptosis-related proteins and the elevation of cardiac enzyme activities, thereby ameliorating oxidative stress injuries in MI mice. Further investigations of oxylipin profiles indicated that EA-AuNPs might alleviate myocardial injury by inhibiting ROS-induced oxylipin level alterations, restoring the perturbed anti-inflammatory oxylipins.

CONCLUSIONS

These findings collectively emphasized the protective role of EA-AuNPs in myocardial injury, which contributes to the development of innovative gold-phenolic nanoparticles and further advances their potential medical applications.

Identification of fatty acid metabolism signature genes in patients with pulmonary arterial hypertension using WGCNA and machine learning

OBJECTIVE

To investigate the signature genes of fatty acid metabolism and their association with immune cells in pulmonary arterial hypertension (PAH).

METHODS

Fatty acid metabolism-related genes were obtained from the GeneCards database. In this retrospective study, a PAH-related dataset was downloaded from the Gene Expression Omnibus database and analyzed to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) and machine learning algorithms, including least absolute shrinkage and selection operator (LASSO) and random forest, were used to identify the signature genes. Diagnostic efficiency was assessed by receiver operating characteristic (ROC) curve analysis and a nomogram. Immune cell infiltration was subsequently classified using CIBERSORT.

RESULTS

In total, 817 DEGs were screened from the GSE33463 dataset. The data were clustered into six modules via WGCNA, and the MEdarkred module was significantly related to PAH. The LASSO and random forest algorithms identified five signature genes: ARV1, KCNJ2, PEX11B, PITPNC1, and SCO1. The areas under the ROC curves of these signature genes were 0.917, 0.934, 0.947, 0.963, and 0.940, respectively. CIBERSORT suggested these signature genes may participate in immune cell infiltration.

CONCLUSIONS

ARV1, KCNJ2, PEX11B, PITPNC1, and SCO1 show remarkable diagnostic performance in PAH and are involved in immune cell infiltration.

CC chemokines Modulate Immune responses in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) represents a progressive condition characterized by the remodeling of pulmonary arteries, ultimately culminating in right heart failure and increased mortality rates. Substantial evidence has elucidated the pivotal role of perivascular inflammatory factors and immune dysregulation in the pathogenesis of PH. Chemokines, a class of small secreted proteins, exert precise control over immune cell recruitment and functionality, particularly with respect to their migration to sites of inflammation. Consequently, chemokines emerge as critical drivers facilitating immune cell infiltration into the pulmonary tissue during inflammatory responses. This review comprehensively examines the significant contributions of CC chemokines in the maintenance of immune cell homeostasis and their pivotal role in regulating inflammatory responses. The central focus of this discussion is directed towards elucidating the precise immunoregulatory actions of CC chemokines concerning various immune cell types, including neutrophils, monocytes, macrophages, lymphocytes, dendritic cells, mast cells, eosinophils, and basophils, particularly in the context of pH processes. Furthermore, this paper delves into an exploration of the underlying pathogenic mechanisms that underpin the development of PH. Specifically, it investigates processes such as cellular pyroptosis, examines the intricate crosstalk between bone morphogenetic protein receptor type 2 (BMPR2) mutations and the immune response, and sheds light on key signaling pathways involved in the inflammatory response. These aspects are deemed critical in enhancing our understanding of the complex pathophysiology of PH. Moreover, this review provides a comprehensive synthesis of findings from experimental investigations targeting immune cells and CC chemokines.

AIM OF REVIEW

In summary, the inquiry into the inflammatory responses mediated by CC chemokines and their corresponding receptors, and their potential in modulating immune reactions, holds promise as a prospective avenue for addressing PH. The potential inhibition of CC chemokines and their receptors stands as a viable strategy to attenuate the inflammatory cascade and ameliorate the pathological manifestations of PH. Nonetheless, it is essential to acknowledge the current state of clinical trials and the ensuing progress, which regrettably appears to be less than encouraging. Substantial hurdles exist in the successful translation of research findings into clinical applications. The intention is that such emphasis could potentially foster the advancement of potent therapeutic agents presently in the process of clinical evaluation. This, in turn, may further bolster the potential for effective management of PH.

Oxylipin profile of human milk and human milk-derived extracellular vesicles

BACKGROUND

Small Extracellular Vesicles (sEVs) are nano-sized vesicles that are present in all biofluids including human milk (HM) playing a crucial role in cell-to-cell communication and the stimulation of the neonatal immune system. Oxylipins, which are bioactive lipids formed from polyunsaturated fatty acids, have gained considerable attention due to their potential role in mitigating disease progression and modulating the inflammatory status of breastfed infants. This study aims at an in-depth characterization of the oxylipin profiles of HM and, for the first time, of HM-derived sEVs (HMEVs) employing an ad-hoc developed and validated ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method.

RESULTS

The UPLC-MS/MS method covered a panel of 13 oxylipins for quantitation and 93 oxylipins for semi-quantitation. In 200 μL of HM and HMEV isolates of 15 individuals, 42 out of 106 oxylipins were detected in either HM or HMEVs, with 38 oxylipins being detected in both matrices. Oxylipins presented distinct profiles in HM and HMEVs, suggesting specific mechanisms responsible for the encapsulation of target molecules in HMEVs. Ten and eight oxylipins were quantified with ranges between 0.03 - 73 nM and 0.30 pM-0.07 nM in HM and HMEVs, respectively. The most abundant oxylipins found in HMEVs were docosahexaenoic acid derivatives (17-HDHA and 14-HDHA) with known anti-inflammatory properties, and linoleic acid derivatives (9-10-DiHOME and 12,13-DiHOME) in HM samples.

SIGNIFICANCE AND NOVELTY

This is the first time a selective, relative enrichment of anti-inflammatory oxylipins in HMEVs has been described. Future studies will focus on the anti-inflammatory and pro-healing capacity of oxylipins encapsulated in HMEVs, with potential clinical applications in the field of preterm infant care, specifically the prevention of severe intestinal complications including necrotizing enterocolitis.

The small-molecule formyl peptide receptor biased agonist, compound 17b, is a vasodilator and anti-inflammatory in mouse precision-cut lung slices

BACKGROUND AND PURPOSE

Pulmonary arterial hypertension (PAH), a rare fatal disorder characterised by inflammation, vascular remodelling and vasoconstriction. Current vasodilator therapies reduce pulmonary arterial pressure but not mortality. The G-protein coupled formyl peptide receptors (FPRs) mediates vasodilatation and resolution of inflammation, actions possibly beneficial in PAH. We investigated dilator and anti-inflammatory effects of the FPR biased agonist compound 17b in pulmonary vasculature using mouse precision-cut lung slices (PCLS).

EXPERIMENTAL APPROACH

PCLS from 8-week-old male and female C57BL/6 mice, intrapulmonary arteries were pre-contracted with 5-HT for concentration-response curves to compound 17b and 43, and standard-of-care drugs, sildenafil, iloprost and riociguat. Compound 17b-mediated relaxation was assessed with FPR antagonists or inhibitors and in PCLS treated with TNF-α or LPS. Cytokine release from TNF-α- or LPS-treated PCLS ± compound 17b was measured.

KEY RESULTS

Compound 17b elicited concentration-dependent vasodilation, with potencies of iloprost > compound 17b = riociguat > compound 43 = sildenafil. Compound 17b was inhibited by the FPR1 antagonist cyclosporin H but not by soluble guanylate cyclase, nitric oxide synthase or cyclooxygenase inhibitors. Under inflammatory conditions, the efficacy and potency of compound 17b were maintained, while iloprost and sildenafil were less effective. Additionally, compound 17b inhibited secretion of PAH-relevant cytokines via FPR2.

CONCLUSIONS AND IMPLICATIONS

Vasodilation to compound 17b but not standard-of-care vasodilators, is maintained under inflammatory conditions, with additional inhibition of PAH-relevant cytokine release. This provides the first evidence that targeting FPR, with biased agonist, simultaneously targets vascular function and inflammation, supporting the development of FPR-based pharmacotherapy to treat PAH.

LINKED ARTICLES

This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.

TRPC4 aggravates hypoxic pulmonary hypertension by promoting pulmonary endothelial cell apoptosis

Pulmonary hypertension (PH) is a devastating disease that lacks effective treatment options and is characterized by severe pulmonary vascular remodeling. Pulmonary arterial endothelial cell (PAEC) dysfunction drives the initiation and pathogenesis of pulmonary arterial hypertension. Canonical transient receptor potential (TRPC) channels, a family of Ca2+-permeable channels, play an important role in various diseases. However, the effect and mechanism of TRPCs on PH development have not been fully elucidated. Among the TRPC family members, TRPC4 expression was markedly upregulated in PAECs from hypoxia combined with SU5416 (HySu)-induced PH mice and monocrotaline (MCT)-treated PH rats, as well as in hypoxia-exposed PAECs, suggesting that TRPC4 in PAECs may participate in the occurrence and development of PH. In this study, we aimed to investigate whether TRPC4 in PAECs has an aggravating effect on PH and elucidate the molecular mechanisms. We observed that hypoxia treatment promoted PAEC apoptosis through a caspase-12/endoplasmic reticulum stress (ERS)-dependent pathway. Knockdown of TRPC4 attenuated hypoxia-induced apoptosis and caspase-3/caspase-12 activity in PAECs. Accordingly, adeno-associated virus (AAV) serotype 6-mediated pulmonary endothelial TRPC4 silencing (AAV6-Tie-shRNA-TRPC4) or TRPC4 antagonist suppressed PH progression as evidenced by reduced right ventricular systolic pressure (RVSP), pulmonary vascular remodeling, PAEC apoptosis and reactive oxygen species (ROS) production. Mechanistically, unbiased RNA sequencing (RNA-seq) suggested that TRPC4 deficiency suppressed the expression of the proapoptotic protein sushi domain containing 2 (Susd2) in hypoxia-exposed mouse PAECs. Moreover, TRPC4 activated hypoxia-induced PAEC apoptosis by promoting Susd2 expression. Therefore, inhibiting TRPC4 ameliorated PAEC apoptosis and hypoxic PH in animals by repressing Susd2 signaling, which may serve as a therapeutic target for the management of PH.

Causal effects between gut microbiota and pulmonary arterial hypertension: A bidirectional Mendelian randomization study

BACKGROUND

Multiple studies have highlighted a potential link between gut microbes and the onset of Pulmonary Arterial Hypertension (PAH). Nonetheless, the precise cause-and-effect relationship remains uncertain.

OBJECTIVES

In this investigation, we utilized a two-sample Mendelian randomization (TSMR) approach to probe the presence of a causal connection between gut microbiota and PAH.

METHODS

Genome-wide association (GWAS) data for gut microbiota and PAH were sourced from MiBioGen and FinnGen research, respectively. Inverse variance weighting (IVW) was used as the primary method to explore the causal effect between gut flora and PAH, supplemented by MR-Egger, weighted median (WM). Sensitivity analyses examined the robustness of the MR results. Reverse MR analysis was used to rule out the effect of reverse causality on the results.

RESULTS

The results indicate that Genus Ruminococcaceae UCG004 (OR = 0.407, P = 0.031) and Family Alcaligenaceae (OR = 0.244, P = 0.014) were protective factors for PAH. Meanwhile Genus Lactobacillus (OR = 2.446, P = 0.013), Class Melainabacteria (OR = 2.061, P = 0.034), Phylum Actinobacteria (OR = 3.406, P = 0.010), Genus Victivallis (OR = 1.980, P = 0.010), Genus Dorea (OR = 3.834, P = 0.024) and Genus Slackia (OR = 2.622, P = 0.039) were associated with an increased Prevalence of PAH. Heterogeneity and pleiotropy were not detected by sensitivity analyses, while there was no reverse causality for these nine specific gut microorganisms.

CONCLUSIONS

This study explores the causal effects of eight gut microbial taxa on PAH and provides new ideas for early prevention of PAH.

Emerging mechanisms of obesity-associated immune dysfunction

Obesity is associated with a wide range of complications, including type 2 diabetes mellitus, cardiovascular disease, hypertension and nonalcoholic fatty liver disease. Obesity also increases the incidence and progression of cancers, autoimmunity and infections, as well as lowering vaccine responsiveness. A unifying concept across these differing diseases is dysregulated immunity, particularly inflammation, in response to metabolic overload. Herein, we review emerging mechanisms by which obesity drives inflammation and autoimmunity, as well as impairing tumour immunosurveillance and the response to infections. Among these mechanisms are obesity-associated changes in the hormones that regulate immune cell metabolism and function and drive inflammation. The cargo of extracellular vesicles derived from adipose tissue, which controls cytokine secretion from immune cells, is also dysregulated in obesity, in addition to impairments in fatty acid metabolism related to inflammation. Furthermore, an imbalance exists in obesity in the biosynthesis and levels of polyunsaturated fatty acid-derived oxylipins, which control a range of outcomes related to inflammation, such as immune cell chemotaxis and cytokine production. Finally, there is a need to investigate how obesity influences immunity using innovative model systems that account for the heterogeneous nature of obesity in the human population.

Two cases of pulmonary arterial hypertension with specific vascular Мalformations and unique eosinophilic inflammation in carriers of the RNF213 p. Arg4810Lys variant: Case series

RNF213 p.Arg4810Lys is linked to various vascular diseases, including pulmonary arterial hypertension (PAH); however, its pathogenesis remains unclear. Here, we report the unique features of two cases of severe PAH with this variant: one is the first reported case with stenosis of the thoracic and abdominal aorta, femoral arteries, and subclavian veins. Coexistence of severe and continuous eosinophilic inflammation, which has been suspected to be implicated in the pathogenesis of PAH in previous fundamental studies, was also present in both cases. Further studies are needed to clarify the pathogenetic mechanisms in vascular lesions with this variant.