Disordered gut microbiota and alterations in the serum metabolome are associated with venous thromboembolism.

INTRODUCTION: The gut microbiome plays a crucial role in various diseases, and its regulation is a potential treatment option for these conditions. However, the relationship between the gut microbiome and venous thromboembolism (VTE) remains poorly explored. METHODS: In this study, we collected feces and serum samples from 8 VTE patients and 7 healthy controls. The gut microbiota and serum metabolites were analyzed using 16S rRNA gene sequencing and liquid chromatography-mass spectrometry, respectively. Additionally, a combined analysis of microbiota and metabolome was performed. RESULTS: The alpha and beta diversity between the VTE and control groups were significantly different. Patients with VTE exhibited an overgrowth of Blautia, Roseburia, Coprococcus, and Ruminococcus. Moreover, serum metabolomics analysis revealed altered levels of choline and lithocholic acid. Pathway enrichment analysis indicated a significant upregulation of bile secretion pathways. In addition, a positive correlation was observed between the levels of serum choline and lithocholic acid and the abundance of gut flora enriched in the VTE group. CONCLUSION: This study provided novel insights into the disordered gut microbiota and serum metabolome associated with VTE, suggesting potential common pathological mechanisms between VTE and arterial thrombosis. Targeted modulation of the gut microbiome may hold promise as a preventive and therapeutic approach for VTE.

Expression of Siglec-9 in peripheral blood neutrophils was increased and associated with disease severity in patients with AECOPD.

BACKGROUND: The pathogenesis and treatment strategies for chronic obstructive pulmonary disease (COPD) require further exploration. Abnormal neutrophil inflammation and the overexpression of neutrophil extracellular traps (NETs) are closely associated with acute exacerbations of COPD (AECOPD). Siglec-9, a specific receptor expressed on neutrophils that inhibits their function, prompted us to investigate its relationship with NETs found in induced sputum and the severity of the disease. METHODS: We collected clinical data from patients with AECOPD and assessed the expression of Siglec-9 in peripheral blood neutrophils and the presence of NETs in induced sputum. We then observed the correlation between Siglec-9, the inflammatory response, and the severity of AECOPD. RESULTS: We observed an increase in the expression of Siglec-9 in the peripheral blood neutrophils of patients with AECOPD. Concurrently, these patients exhibited more severe clinical symptoms, higher systemic inflammation levels, and a reduced quality of life compared to those with induced sputum NET expression. Further subgroup analysis of AECOPD patients with high Siglec-9 expression revealed worsened quality of life and more severe inflammation, particularly in indicators such as the BODE index, CRP, peripheral blood neutrophil count, IL-6, IL-8, TNF-α expression, and others. Furthermore, we noted a significant increase in NET-specific expression in the sputum of patients with high Siglec-9 expression levels. In comparison to patients with low Siglec-9 expression, those with high expression experienced more systemic inflammatory reactions and a lower quality of life. Correlation analysis of the aforementioned indicators revealed that the expression ratio of Siglec-9 in the peripheral blood of patients correlated with lung function, quality of life, and NETs in the induced sputum of patients with AECOPD. CONCLUSION: The increased expression of Siglec-9 in peripheral blood neutrophils of AECOPD patients leads to elevated NET expression in induced sputum, exacerbating the systemic inflammatory response and worsening lung function and quality of life in these patients.

Oxidative stress in acute pulmonary embolism: emerging roles and therapeutic implications.

Oxidative stress is an imbalance between the body's reactive oxygen species and antioxidant defense mechanisms. Oxidative stress is involved in the development of several cardiovascular diseases, such as pulmonary hypertension, atherosclerosis, and diabetes mellitus. A growing number of studies have suggested the potential role of oxidative stress in the pathogenesis of pulmonary embolism. Biomarkers of oxidative stress in pulmonary embolism have also been explored, such as matrix metalloproteinases, asymmetric dimethylarginine, and neutrophil/lymphocyte ratio. Here, we comprehensively summarize some oxidative stress mechanisms and biomarkers in the development of acute pulmonary embolism and summarize related treatments based on antioxidant stress to explore effective treatment strategies for acute pulmonary embolism.

Molecular design and systematic optimization of a halogen-bonding system between the asthma interleukin-5 receptor and its cyclic peptide ligand.

Human interleukin-5 (IL-5) functions as an important pro-inflammatory factor by binding to its specific receptor, IL-5Rα, which has been implicated in the pathogenesis of asthma. Previously, a disulfide-bonded cyclic peptide AF17121 obtained from random library screening and sequence variation was found to competitively disrupt the cognate IL-5Rα/IL-5 interaction with moderate potency. In this study, the crystal complex of IL-5Rα with AF17121 was investigated at structural and energetic levels. It is revealed that the side-chain indole moiety of the AF17121 Trp5 residue is a potential site for a stem putative halogen bond (X-bond) with IL-5Rα, which is just located within the key 3 EXXR6 motif region recognized specifically by IL-5Rα. We systematically examined four halogen substitution types at five positions of the indole moiety; QM/MM calculations theoretically unraveled that only halogenations at 5 and 6 positions can form effective X-bonds with the side-chain hydroxyl oxygen of the IL-5Rα Thr21 residue and the backbone carbonyl oxygen of Ala66 residue, respectively. Binding assays observed that I-substitution at the 5 position and Br-substitution at the 6 position can result in two potent halogenated peptides, [5I]AF17121 and [6Br]AF17121, which are improved by 1.6-fold and 3.5-fold relative to the native AF17121, respectively. 5I/6Br-double substitution, resulting in [5I/6Br]AF17121, can further enhance the peptide affinity by 7.5-fold. Structural analysis revealed that the X-bond stemming from 6Br-substitution is also involved in an orthogonal interaction system with a H-bond; they share a common backbone carbonyl oxygen acceptor of IL-5Rα Ala66 residue and exhibit a significant synergistic effect between them.

A novel defined pyroptosis-related gene signature predicts prognosis and correlates with the tumour immune microenvironment in lung adenocarcinoma.

Lung adenocarcinoma (LUAD) is one of the most common causes of cancer-related death. The role of pyroptosis in LUAD remains unclear. Our study aimed to identify a prognostic signature of pyroptosis-related genes (PRGs) and explore the connection of PRGs with the tumour microenvironment in LUAD. Gene expression and clinical information were obtained from The Cancer Genome Atlas database. Consensus clustering was applied to classify LUAD patients. The least absolute shrinkage and selection operator Cox and multivariate Cox regression models were used to generate a PRG-related prognostic signature. The correlations between PRGs and tumour-infiltrating immune cells or the tumour mutational burden were analysed by Spearman's correlation analysis. In this study, 44 PRGs significantly differed in expression between LUAD and normal tissues. Based on these genes, patients were clustered into three clusters with significantly different distributions of tumour-infiltrating immune cells and immune checkpoint regulators. A total of four PRGs (NLRP1, HMGB1, CYCS, and BAK1) were used to construct a prognostic model. Significant correlations were observed between these prognostic PRGs and immune cell infiltration or the tumour mutational burden. Predictive nomogram results showed that BAK1 could be an independent prognostic biomarker in LUAD. Additionally, the expression level of BAK1 was validated in two independent Gene Expression Omnibus cohorts. Our identified prognostic PRG signature may provide insight for future studies targeting pyroptosis and the tumour microenvironment in LUAD. Future studies are needed to verify our current findings.

Coupled folding-upon-binding of human tumor suppressor MIG6 to lung cancer EGFR kinase domain and molecular trimming/stapling of MIG6-derived ß-hairpins to target the coupling event.

Human epidermal growth factor receptor (EGFR) is involved in strong association with malignant proliferation, which has been shown to play a central role in the development and progression of non-small cell lung cancer and other solid tumors. The tumor-suppressor protein MIG6 is a negative regulator of EGFR kinase activity by binding at the activation interface of asymmetric dimer of EGFR kinase domain to disrupt EGFR dimerization and then inactivate the kinase. The protein adopts two discrete fragments 1 and 2 to directly interact with EGFR. It is revealed that the MIG6 fragment 2 is intrinsically disordered in free unbound state, but would fold into a well-structured ß-hairpin when binding to EGFR, thus characterized by a so-called coupled folding-upon-binding process, which can be regarded as a compromise between favorable direct readout and unfavorable indirect readout. Here, a 23-mer F2P peptide was derived from MIG6 fragment 2, trimmed into a 17-mer tF2P peptide that contains the binding hotspot region of the fragment 2, and then constrained with an ordered hairpin conformation in free unbound state by disulfide stapling, finally resulting in a rationally stapled/trimmed stF2P peptide that largely minimizes the unfavorable indirect readout effect upon its binding to EGFR kinase domain, with affinity improved considerably upon the trimming and stapling/trimming. These rationally designed ß-hairpin peptides may be further exploited as potent anti-lung cancer agents to target the activation event of EGFR dimerization.

Circular RNAs Regulate Vascular Remodelling in Pulmonary Hypertension.

Circular RNAs (circRNAs) are a newly identified type of noncoding RNA molecule with a unique closed-loop structure. circRNAs are widely expressed in different tissues and developmental stages of many species, participating in many important pathophysiological processes and playing an important role in the occurrence and development of diseases. This article reviews the discovery, characteristics, formation, and biological function of circRNAs. The relationship between circRNAs and vascular remodelling, as well as the current status of research and potential application value in pulmonary hypertension (PH), is discussed to promote a better understanding of the role of circRNAs in PH. circRNAs are closely related to the remodelling of vascular endothelial cells and vascular smooth muscle cells. circRNAs have potential application prospects for in-depth research on the possible pathogenesis and mechanism of PH. Future research on the role of circRNAs in the pathogenesis and mechanism of PH will provide new insights and promote screening, diagnosis, prevention, and treatment of this disease.

Wogonin attenuates neutrophilic inflammation and airway smooth muscle proliferation through inducing caspase-dependent apoptosis and inhibiting MAPK/Akt signaling in allergic airways.

BACKGROUND: Severe neutrophilic asthma is often characterized by persistent airway inflammation and irreversible airway remodeling, which are overstimulated by the high-mobility group box protein 1 (HMGB1). Although wogonin, an O-methylated flavone, has been widely used to treat inflammatory and allergic diseases, its therapeutic effects and potential mechanisms on severe neutrophilic asthma remain elusive. OBJECTIVE: To evaluate whether wogonin alleviates airway neutrophilia through inducing neutrophil apoptosis and attenuates airway smooth muscle cells (ASMCs) proliferation and migration. METHODS: The effect of wogonin on reducing neutrophilic airway inflammation, including neutrophil infiltration and inflammatory mediators, was examined in a mouse model of severe neutrophilic asthma sensitized with ovalbumin and lipopolysaccharide. Also, the effect of wogonin on inducing human neutrophil apoptosis was manifested using cellular morphology, flow cytometry, and caspase inhibition assays. Furthermore, the effect of wogonin on inhibiting HMGB1-mediated ASMCs proliferation and migration was determined. RESULTS: Wogonin reduced the frequency of neutrophils and inhibited the production of multiple inflammatory mediators, including ovalbumin-specific IgE, tumor necrosis factor-α, interleukin-6, and HMGB1, in bronchoalveolar lavage fluid and lung tissues of the neutrophilic asthmatic mouse model. These data strongly support a significantly suppressed neutrophilic airway inflammation, functionally consistent to the relieved airway hyperresponsiveness by wogonin in vivo. Wogonin induced human neutrophil apoptosis in a dose-dependent manner by activating caspase-8 and caspase-3 in vitro. Wogonin pretreatment abolished HMGB1-induced ASMCs proliferation and migration, which can be explained by the inhibition of phosphorylation in the mitogen-activated protein kinase (MAPK) /Akt singling pathways. CONCLUSION: Our findings demonstrate that wogonin augments caspase-dependent apoptosis in neutrophils to alleviate neutrophilic inflammatory responses and regulates intracellular signaling to inhibit HMGB1-mediated ASMCs activation, providing a promising therapeutic agent for severe neutrophilic asthma.

Identification of potential biomarkers and pathogenesis in neutrophil-predominant severe asthma: A comprehensive bioinformatics analysis.

BACKGROUND: Airway neutrophilia has been associated with asthma severity and asthma exacerbations. This study attempted to identify biomarkers, pathogenesis, and therapeutic molecular targets for severe asthma in neutrophils using bioinformatics analysis. METHODS: Fifteen healthy controls and 3 patients with neutrophilic severe asthma were screened from the Gene Expression Omnibus (GEO) database. Based on the analysis of differentially expressed genes (DEGs), functional and pathway enrichment analyses, gene set enrichment analysis, protein-protein interaction network construction, and analysis were performed. Moreover, small-molecule drug candidates have also been identified. RESULTS: Three hundred and three upregulated and 59 downregulated genes were identified. Gene ontology function enrichment analyses were primarily related to inflammatory response, immune response, leukocyte migration, neutrophil chemotaxis, mitogen-activated protein kinase cascade, Jun N-terminal kinase cascade, I-kappaB kinase/nuclear factor-κB, and MyD88-dependent toll-like receptor signaling pathway. Pathway enrichment analyses and gene set enrichment analysis were mainly involved in cytokine-cytokine receptor interaction, the TNF signaling pathway, leukocyte transendothelial migration, and the NOD-like receptor signaling pathway. Furthermore, 1 important module and 10 hub genes (CXCL8, TLR2, CXCL1, ICAM1, CXCR4, FPR2, SELL, PTEN, TREM1, and LEP) were identified in the protein-protein interaction network. Moreover, indoprofen, mimosine, STOCK1N-35874, trapidil, iloprost, aminoglutethimide, ajmaline, levobunolol, ethionamide, cefaclor, dimenhydrinate, and bethanechol are potential drugs for the treatment of neutrophil-predominant severe asthma. CONCLUSION: This study identified potential biomarkers, pathogenesis, and therapeutic molecular targets for neutrophil-predominant severe asthma.

Research advances in Dieulafoy's disease of the bronchus (Review).

Dieulafoy's disease is characterized by abnormal submucosal arteries and results in acute luminal hemorrhage. Dieulafoy's lesions can also be found in the submucosa of the bronchus. Due to its low incidence rate and non-specific clinical symptoms, Dieulafoy's disease is easy to overlook, but can lead to massive bleeding and high rates of mortality. Therefore, improvements in the understanding of the disease are necessary. The awareness of the disease and associated diagnostic and treatment techniques have continued to improve, and thus, an increasing number of cases of Dieulafoy's disease of the bronchus have been reported. In the present review, 74 cases of Dieulafoy's disease are summarized. New technologies such as endobronchial ultrasound, narrow-band imaging, angiography and argon plasma treatment have been found to be increasingly applied to diagnose and treat Dieulafoy's disease of the bronchus. Therefore, the primary focus of this systematic review is to highlight advances in the diagnosis and treatment of bronchial Dieulafoy's disease.

Efficacy of Liuzijue Qigong in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis.

BACKGROUND: Liuzijue is a traditional Qigong exercise that is commonly performed in China. However, the treatment effects of Liuzijue Qigong are controversial. The aim of this systematic review was to evaluate the efficacy of Liuzijue Qigong in patients with chronic obstructive pulmonary disease (COPD). METHODS: Randomised controlled trials were identified by searching several English and Chinese databases from inception to August 8, 2020. Study selection and data extraction were independently performed by two investigators. Data synthesis and analysis were carried out with Review Manager software 5.2. Quality assessment for each study was based on the modified Jadad scale. RESULTS: Forty studies with 3137 participants were included. Significant improvements were observed in the following outcomes (mean difference, 95% confidence interval): forced expiratory volume in 1 s (0.17, 0.09-0.25) and its percent predicted normal value (6.04, 3.43-8.65), forced expiratory volume in 1 s to forced volume capacity ratio (6.95, 3.06-10.83), 6-min walking distance (33.06, 23.73-42.38), 30-s sit-to-stand test (2.65, 0.98-4.32), COPD assessment test score (- 2.04, - 2.77 to - 1.30), modified Medical Research Council dyspnea scale (- 0.34, - 0.48 to - 0.20), Medical Research Council dyspnea scale (- 0.37, - 0.57 to - 0.18), Traditional Chinese Medicine syndrome score (- 1.85, - 2.86 to - 0.85), Hamilton Anxiety Scale (- 2.31, - 3.04 to - 1.59), Hamilton Depression Scale (- 2.08, - 2.45 to - 1.71) and St. George's Respiratory Questionnaire (- 6.94, - 9.20 to - 4.67). CONCLUSIONS: Liuzijue Qigong may be an effective adjuvant therapy for the improvement of lung function, exercise capacity, health status, mental status and quality of life in patients with COPD.

Remotely monitored Baduanjin exercise in moderate-to-severe chronic obstructive pulmonary disease patients (BROCADE): A study protocol.

BACKGROUND: Baduanjin is a traditional Chinese exercise regimen used to treat various chronic illnesses and is associated with both psychological and physical benefits. However, its benefits for patients suffering from chronic obstructive pulmonary disease (COPD) are unclear. This study aims to assess the efficacy, safety, and underlying mechanisms of Baduanjin exercise in patients with moderate-to-severe COPD (BROCADE) by remote monitoring. METHODS: This study protocol describes a multicenter, open-label, prospective randomized computed tomography. A total of 150 individuals who meet the inclusion criteria after the screening and consent processes will take part in the study. All participants will be provided routine medication and lifestyle interventions. They will be randomly assigned to a control group, a classical pulmonary rehabilitation group, or a Baduanjin group, which will undergo remotely monitored Baduanjin exercises for a cumulative duration of 1 hour per day, three times per week for 12 weeks. The participants will be followed for 24 weeks. The primary outcomes will be a 6-minutes walking distance and St. George's Respiratory Questionnaire index. The secondary outcomes will be lung function, cross-sectional area of the pectoralis major and subcutaneous fat, modified Medical Research Council score, COPD assessment test questionnaire results, extremity muscle strength, and quality of life. Any adverse events that may occur will be monitored and recorded. RESULTS: This study is ongoing and will be submitted to a peer-reviewed journal for publication once completed. CONCLUSION: A novel neutrophil-related inflammatory mechanism will potentially be identified. In addition, the study results will provide a safe, effective, simple and operational Baduanjin exercise protocol for moderate-to-severe COPD patients aimed at improving prognosis and quality of life.

Impact of renal function on the prognosis of acute pulmonary embolism patients: a systematic review and meta-analysis.

OBJECTIVES: We conduct a study to explore the influence of impaired renal function on prognosis in Acute pulmonary embolism (APE) patients. METHODS: A meta-analysis was performed using the EMBASE and PubMed databases for relevant publications reporting the impact of impaired renal function on the clinical outcomes in patients with APE. RESULTS: Eventually, 17 articles were included in our analysis. The results suggested that renal insufficiency (RI) is a predictor of poor prognosis in APE patients(short-term mortality: pooled OR = 2.83, 95%CI: 2.20-3.63; long-term mortality: pooled OR = 2.30, 95%CI: 1.72-3.08; adverse outcomes: pooled OR = 3.02, 95%CI: 2.60-3.51). The short-term and long-term mortality rates of APE patients with RI were both higher than those in patients without RI. In addition, acute kidney injury(AKI) could serve as a predictive factor of poor prognosis (pooled OR = 2.75, 95%CI: 2.45-3.08), and it doubles the overall mortality rate in APE patients. However, chronic kidney disease (CKD) did not predict poor prognosis in APE patients (pooled OR = 1.94, 95%CI: 0.99-3.81), although it could slightly increase the overall mortality rate in APE patients. CONCLUSIONS: RI and AKI could be included in the prognosis evaluation for APE, but the impact of CKD in APE patients has yet to be determined.

Bioinformatics analyses of the pathogenesis and new biomarkers of chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is one of the major cause of global death. The purpose of our analysis was to detect a more reliable biomarker and small-molecule drug candidates and to identify the precise mechanisms involved in COPD. METHODS: Three data sets were downloaded from the Gene Expression Omnibus database and analysed by Gene Expression Omnibus 2R. Functional enrichment analyses were performed by Metascape. We use the STRING data to build a protein-protein interaction network. The targets of differentially expressed microRNA (DE miRNA) were predicted by the miRWalk database. Small-molecule drugs were predicted on connectivity map. RESULTS: A total of 181 differentially expressed genes and 35 DE miRNAs were confirmed. The protein-protein interaction network including all integrated differentially expressed genes was constructed, and 4 modules were filtrated. The module genes were relative to immune, inflammatory and oxidative stress functions according to a pathway analysis. The top 20 key genes were screened. Among the DE miRNAs found to be regulating key genes, miR-194-3p, MiR-502-5p, MiR-5088-5p, MiR-3127-5p, and miR-23a-5p might be the most significant due to their high number of connecting nodes in COPD. In addition, cephaeline, emetine, gabapentin, and amrinone were found to be potential drugs to treat COPD patients. CONCLUSION: Our study suggests that miR-194-3p, miR-502-5p, and miR-23a-5p might participate in the nosogenesis of COPD. In addition, 4 potential small-molecule drugs were considered potentially useful for treating COPD patients.

Construction and analysis of the abnormal lncRNA-miRNA-mRNA network in hypoxic pulmonary hypertension.

The incidence of hypoxic pulmonary hypertension (HPH) is increasing. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) play an important role in HPH, but the functions and mechanism have yet to be fully elucidated. In the present study, we established a HPH rat model with 8 h of hypoxia exposure (10% O2) per day for 21 days. High-throughput sequencing identified 60 differentially expressed (DE) lncRNAs, 20 DE miRNAs and 695 DE mRNAs in rat lung tissue. qRT-PCR verified the accuracy of the results. The DE mRNAs were significantly enriched in immune response, inflammatory response, leukocyte migration, cell cycle, cellular response to interleukin-1, IL-17 signalling pathway, cytokine-cytokine receptor interaction and Toll-like receptor signalling pathway. According to the theory of competing endogenous RNA (ceRNA) networks, lncRNA-miRNA-mRNA network was constructed by Cytoscape software, 16 miRNAs and 144 mRNAs. The results suggested that seven DE lncRNAs (Ly6l, AABR07038849.2, AABR07069008.2, AABR07064873.1, AABR07001382.1, AABR07068161.1 and AABR07060341.2) may serve as molecular sponges of the corresponding miRNAs and play a major role in HPH.

Sialic acid-binding immunoglobulin-like lectin 9 as a potential therapeutic target for chronic obstructive pulmonary disease.

ABSTRACT: Chronic obstructive pulmonary disease (COPD) has become the third-leading cause of death worldwide, which is a severe economic burden to the healthcare system. Chronic bronchitis is the most common condition that contributes to COPD, both locally and systemically. Neutrophilic inflammation predominates in the COPD airway wall and lumen. Logically, repression of neutrophilia is an essential fashion to COPD treatment. However, currently available anti-neutrophilic therapies provide little benefit in COPD patients and may have serious side effects. Thus, there is an urgent need to explore an effective and safe anti-neutrophilic approach that might delay progression of the disease. Sialic acid-binding immunoglobulin-like lectin (Siglec)-9 is a member of the Siglec cell surface immunoglobulin family. It is noteworthy that Siglec-9 is highly expressed on human neutrophils and monocytes. Ligation of Siglec-9 by chemical compounds or synthetic ligands induced apoptosis and autophagic-like cell death in human neutrophils. Furthermore, administration of antibody to Siglec-E, mouse functional ortholog of Siglec-9, restrained recruitment and activation of neutrophils in mouse models of airway inflammation in vivo. Given the critical role that neutrophils play in chronic bronchitis and emphysema, targeting Siglec-9 could be beneficial for the treatment of COPD, asthma, fibrosis, and related chronic inflammatory lung diseases.

Regulation of circular RNAs act as ceRNA in a hypoxic pulmonary hypertension rat model.

To explore potential critical genes and identify circular RNAs (circRNAs) that act as the competitive endogenous RNA (ceRNA) in a hypoxic pulmonary hypertension (HPH) rat model. Constructed rat model, and a bioinformatics method was used to analyse differentially expressed (DE) genes and construct a circRNA-miRNA-mRNA ceRNA regulatory network. Then, qRT-PCR was used to verify. The significant DEcircRNAs/DEmiRNAs/DEmRNAs was showed, and a ceRNA network with 8 DEcircRNAs, 9 DEmiRNAs and 46 DEmRNAs were constructed. The functional enrichment suggested the inflammatory response, NF-κB signalling, MAPK cascade and Toll-like receptor were associated with HPH. Further assessment confirmed that circ_002723, circ_008021, circ_016925 and circ_020581 could have a potential ceRNA mechanism by sponging miR-23a or miR-21 to control downstream target gene and be involved in the pathophysiology of HPH. The qRT-PCR validation results were consistent with the RNA-Seq results. This study revealed potentially important genes, pathways and ceRNA regulatory networks in HPH.

PDGF mediates pulmonary arterial smooth muscle cell proliferation and migration by regulating NFATc2.

The reconstruction of pulmonary vascular structure caused by the proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) is the central link in the formation of pulmonary arterial hypertension (PAH). Platelet­derived growth factor (PDGF) can regulate the proliferation and migration of PASMCs. At the same time, nuclear factor of activated T cells (NFATs) plays an important role in the development of PAH. To the best of our knowledge, there are no reports yet regarding whether PDGF regulates NFATc2 to increase the proliferation of PASMCs. The present study aimed to investigate whether PDGF affects the proliferation and migration of PASMCs by regulating NFAT, and to study the pathogenesis of PAH. PASMCs were treated with recombinant PDGF; Cell Counting Kit­8 and clone formation experiments showed that PDGF enhanced the cell viability and proliferation of PASMCs. Cell cycle distribution and molecular markers related to cell proliferation (cyclin D1, CDK4 and Proliferating Cell Nuclear Antigen) were detected by flow cytometry, and the results indicated that PDGF promoted the division of PAMSCs. The scratch migration and Transwell migration assays showed that the migratory ability of PASMCs was enhanced following PDGF treatment. Changes in NFATs (NFATc1­5) after PDGF treatment were evaluated by reverse transcription­quantitative PCR and western blotting; NFATc2 showed the most significant results. Finally, PDGF­treated cells were treated with an NFAT pathway inhibitor, cyclosporin A, or a small interfering RNA targeting NFATc2, and changes in cell proliferation and migration were evaluated to assess the role of NFATc2 in PDGF­induced cell proliferation and migration. In conclusion, PDGF may regulate PASMC proliferation and migration by regulating the expression of NFAT, further leading to the occurrence of PAH. It is proposed that NFATc2 could be used as a potential target for PAH treatment.