Osmosensor-mediated control of Ca2+ spiking in pollen germination.

Higher plants survive terrestrial water deficiency and fluctuation by arresting cellular activities (dehydration) and resuscitating processes (rehydration). However, how plants monitor water availability during rehydration is unknown. Although increases in hypo-osmolarity-induced cytosolic Ca2+ concentration (HOSCA) have long been postulated to be the mechanism for sensing hypo-osmolarity in rehydration1,2, the molecular basis remains unknown. Because osmolarity triggers membrane tension and the osmosensing specificity of osmosensing channels can only be determined in vivo3-5, these channels have been classified as a subtype of mechanosensors. Here we identify bona fide cell surface hypo-osmosensors in Arabidopsis and find that pollen Ca2+ spiking is controlled directly by water through these hypo-osmosensors-that is, Ca2+ spiking is the second messenger for water status. We developed a functional expression screen in Escherichia coli for hypo-osmosensitive channels and identified OSCA2.1, a member of the hyperosmolarity-gated calcium-permeable channel (OSCA) family of proteins6. We screened single and high-order OSCA mutants, and observed that the osca2.1/osca2.2 double-knockout mutant was impaired in pollen germination and HOSCA. OSCA2.1 and OSCA2.2 function as hypo-osmosensitive Ca2+-permeable channels in planta and in HEK293 cells. Decreasing osmolarity of the medium enhanced pollen Ca2+ oscillations, which were mediated by OSCA2.1 and OSCA2.2 and required for germination. OSCA2.1 and OSCA2.2 convert extracellular water status into Ca2+ spiking in pollen and may serve as essential hypo-osmosensors for tracking rehydration in plants.

Single-Nucleus Transcriptomic Atlas of Human Pericoronary Epicardial Adipose Tissue in Normal and Pathological Conditions.

BACKGROUND: Pericoronary epicardial adipose tissue (EAT) is a unique visceral fat depot that surrounds the adventitia of the coronary arteries without any anatomic barrier. Clinical studies have demonstrated the association between EAT volume and increased risks for coronary artery disease (CAD). However, the cellular and molecular mechanisms underlying the association remain elusive. METHODS: We performed single-nucleus RNA sequencing on pericoronary EAT samples collected from 3 groups of subjects: patients undergoing coronary bypass surgery for severe CAD (n=8), patients with CAD with concomitant type 2 diabetes (n=8), and patients with valvular diseases but without concomitant CAD and type 2 diabetes as the control group (n=8). Comparative analyses were performed among groups, including cellular compositional analysis, cell type-resolved transcriptomic changes, gene coexpression network analysis, and intercellular communication analysis. Immunofluorescence staining was performed to confirm the presence of CAD-associated subclusters. RESULTS: Unsupervised clustering of 73 386 nuclei identified 15 clusters, encompassing all known cell types in the adipose tissue. Distinct subpopulations were identified within primary cell types, including adipocytes, adipose stem and progenitor cells, and macrophages. CD83high macrophages and FOSBhigh adipocytes were significantly expanded in CAD. In comparison to normal controls, both disease groups exhibited dysregulated pathways and altered secretome in the primary cell types. Nevertheless, minimal differences were noted between the disease groups in terms of cellular composition and transcriptome. In addition, our data highlight a potential interplay between dysregulated circadian clock and altered physiological functions in adipocytes of pericoronary EAT. ANXA1 (annexin A1) and SEMA3B (semaphorin 3B) were identified as important adipokines potentially involved in functional changes of pericoronary EAT and CAD pathogenesis. CONCLUSIONS: We built a complete single-nucleus transcriptomic atlas of human pericoronary EAT in normal and diseased conditions of CAD. Our study lays the foundation for developing novel therapeutic strategies for treating CAD by targeting and modifying pericoronary EAT functions.

Association of PLXND1 with a novel subtype of anomalous pulmonary venous return.

Anomalous pulmonary venous return (APVR) is a potentially lethal congenital heart disease. Elucidating the genetic etiology is crucial for understanding its pathogenesis and improving clinical practice, whereas its genetic basis remains largely unknown because of complex genetic etiology. We thus performed whole-exome sequencing for 144 APVR patients and 1636 healthy controls and report a comprehensive atlas of APVR-related rare genetic variants. Novel singleton, loss-of-function and deleterious missense variants (DVars) were enriched in patients, particularly for genes highly expressed in the developing human heart at the critical time point for pulmonary veins draining into the left atrium. Notably, PLXND1, encoding a receptor for semaphorins, represents a strong candidate gene of APVR (adjusted P = 1.1e-03, odds ratio: 10.9-69.3), accounting for 4.17% of APVR. We further validated this finding in an independent cohort consisting of 82 case-control pairs. In these two cohorts, eight DVars were identified in different patients, which convergently disrupt the GTPase-activating protein-related domain of PLXND1. All variant carriers displayed strikingly similar clinical features, in that all anomalous drainage of pulmonary vein(s) occurred on the right side and incorrectly connected to the right atrium, which may represent a novel subtype of APVR for molecular diagnosis. Studies in Plxnd1 knockout mice further revealed the effects of PLXND1 deficiency on severe heart and lung defects and cellular abnormalities related to APVR such as abnormal migration and vascular formation of vascular endothelial cells. These findings indicate the important role of PLXND1 in APVR pathogenesis, providing novel insights into the genetic etiology and molecular subtyping for APVR.

Visible-Light-Induced Transition-Metal-Free Redox-Neutral Carboxylation of Remote Benzylic C(sp3)-H Bonds via 1,5-Hydrogen Atom Transfer.

The direct carboxylation of the benzylic C-H bonds under mild conditions is of great importance and is quite challenging. Herein, we report an approach for the carboxylation of remote benzylic C(sp3)-H bonds by integrating the redox-neutral visible-light photoredox catalysis and the nitrogen-centered 1,5-hydrogen atom transfer. The chemical transformation progresses via consecutive single electron transfer, 1,5-hydrogen atom transfer, formation of benzylic carbanion, and nucleophilic attack on the CO2 steps, thereby enabling access to the desired carboxylation products with moderate to high yields. We also endeavor to recover the CO2 groups generated in situ intramolecularly to achieve carboxylation under a nitrogen atmosphere, resulting in moderate yields of corresponding carboxylation.

Single-cell transcriptomic landscape of cardiac neural crest cell derivatives during development.

The migratory cardiac neural crest cells (CNCCs) contribute greatly to cardiovascular development. A thorough understanding of the cell lineages, developmental chronology, and transcriptomic states of CNCC derivatives during normal development is essential for deciphering the pathogenesis of CNCC-associated congenital anomalies. Here, we perform single-cell transcriptomic sequencing of 34,131 CNCC-derived cells in mouse hearts covering eight developmental stages between E10.5 and P7. We report the presence of CNCC-derived mural cells that comprise pericytes and microvascular smooth muscle cells (mVSMCs). Furthermore, we identify the transition from the CNCC-derived pericytes to mVSMCs and the key regulators over the transition. In addition, our data support that many CNCC derivatives had already committed or differentiated to a specific lineage when migrating into the heart. We explore the spatial distribution of some critical CNCC-derived subpopulations with single-molecule fluorescence in situ hybridization. Finally, we computationally reconstruct the differentiation path and regulatory dynamics of CNCC derivatives. Our study provides novel insights into the cell lineages, developmental chronology, and regulatory dynamics of CNCC derivatives during development.

INKA2-AS1 Is a Potential Promising Prognostic-Related Biomarker and Correlated with Immune Infiltrates in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a malignancy with one of the worst prognoses. Long noncoding RNAs (lncRNAs) may be important in cancer development and may serve as new biomarkers for the diagnosis and treatment of various tumors, according to mounting research. The purpose of this study was to investigate the expression of INKA2-AS1 and clinical importance in HCC patients. The TCGA database was used to obtain the human tumor samples, while the TCGA and GTEx databases were used to gather the human normal samples. We screened differentially expressed genes (DEGs) between HCC and nontumor tissues. Investigations were made into the statistical significance and clinical significance of INKA2-AS1 expression. A single-sample gene set enrichment analysis (ssGSEA) was used to examine potential relationships between immune cell infiltration and INKA2-AS1 expression. In this investigation, we found that HCC specimens had considerably greater levels of INKA2-AS1 expression than nontumor specimens. When utilizing the TCGA datasets and the GTEx database, high INKA2-AS1 expression showed an AUC value for HCC of 0.817 (95% confidence interval: 0.779 to 0.855). Pan-cancer assays revealed that numerous tumor types had dysregulated levels of INKA2-AS1. Gender, histologic grade, and pathologic stage were all substantially correlated with high INKA2-AS1 expression. A survival study indicated that HCC patients with high INKA2-AS1 expression have shorter OS, DSS, and PFI than those with low INKA2-AS1 expression. Multivariate analysis indicated that INKA2-AS1 expression was an independent prognostic factor for OS of patients with HCC. According to immune analysis, the expression of INKA2-AS1 was favorably correlated with T helper cells, Th2 cells, macrophages, TFH, and NK CD56bright cells and negatively correlated with Th17 cells, pDC, cytotoxic cells, DC, Treg, Tgd, and Tcm. The results of this study collectively suggest that INKA2-AS1 has the potential to be a novel biomarker for predicting the prognosis of HCC patients as well as a significant immune response regulator in HCC.

Defective Nature of CdSe Quantum Dots Embedded in Inorganic Matrices.

Quantum dots (QDs) embedded in inorganic matrices have been extensively studied for their potential applications in lighting, displays, and solar cells. While a significant amount of research studies focused on their experimental fabrication, the origin of their relatively low photoluminescence quantum yield has not been investigated yet, although it severely hinders practical applications. In this study, we use time-dependent density functional theory (TDDFT) to pinpoint the nature of excited states of CdSe QDs embedded in various inorganic matrices. The formation of undercoordinated Se atoms and nonbridging oxygen atoms at the QD/glass interface is responsible for the localization of a hole wave function, leading to the formation of low-energy excited states with weak oscillator strength. These states provide pathways for nonradiative processes and compete with radiative emission. The photoluminescence performance is predicted for CdSe QDs in different matrices and validated by experiments. The results of this study have significant implications for understanding the underlying photophysics of CdSe QDs embedded in inorganic matrices that would facilitate the fabrication of highly luminescent glasses.

HTAADVar: Aggregation and fully automated clinical interpretation of genetic variants in heritable thoracic aortic aneurysm and dissection.

PURPOSE: Early detection and pathogenicity interpretation of disease-associated variants are crucial but challenging in molecular diagnosis, especially for insidious and life-threatening diseases, such as heritable thoracic aortic aneurysm and dissection (HTAAD). In this study, we developed HTAADVar, an unbiased and fully automated system for the molecular diagnosis of HTAAD. METHODS: We developed HTAADVar (http://htaadvar.fwgenetics.org) under the American College of Medical Genetics and Genomics/Association for Molecular Pathology framework, with optimizations based on disease- and gene-specific knowledge, expert panel recommendations, and variant observations. HTAADVar provides variant interpretation with a self-built database through the web server and the stand-alone programs. RESULTS: We constructed an expert-reviewed database by integrating 4373 variants in HTAAD genes, with comprehensive metadata curated from 697 publications and an in-house study of 790 patients. We further developed an interpretation system to assess variants automatically. Notably, HTAADVar showed a multifold increase in performance compared with public tools, reaching a sensitivity of 92.64% and specificity of 70.83%. The molecular diagnostic yield of HTAADVar among 790 patients (42.03%) also matched the clinical data, independently demonstrating its good performance in clinical application. CONCLUSION: HTAADVar represents the first fully automated system for accurate variant interpretation for HTAAD. The framework of HTAADVar could also be generalized for the molecular diagnosis of other genetic diseases.

OSCA1 is an osmotic specific sensor: a method to distinguish Ca2+ -mediated osmotic and ionic perception.

Genetic mutants defective in stimulus-induced Ca2+ increases have been gradually isolated, allowing the identification of cell-surface sensors/receptors, such as the osmosensor OSCA1. However, determining the Ca2+ -signaling specificity to various stimuli in these mutants remains a challenge. For instance, less is known about the exact selectivity between osmotic and ionic stresses in the osca1 mutant. Here, we have developed a method to distinguish the osmotic and ionic effects by analyzing Ca2+ increases, and demonstrated that osca1 is impaired primarily in Ca2+ increases induced by the osmotic but not ionic stress. We recorded Ca2+ increases induced by sorbitol (osmotic effect, OE) and NaCl/CaCl2 (OE + ionic effect, IE) in Arabidopsis wild-type and osca1 seedlings. We assumed the NaCl/CaCl2 total effect (TE) = OE + IE, then developed procedures for Ca2+ imaging, image analysis and mathematic fitting/modeling, and found osca1 defects mainly in OE. The osmotic specificity of osca1 suggests that osmotic and ionic perceptions are independent. The precise estimation of these two stress effects is applicable not only to new Ca2+ -signaling mutants with distinct stimulus specificity but also the complex Ca2+ signaling crosstalk among multiple concurrent stresses that occur naturally, and will enable us to specifically fine tune multiple signal pathways to improve crop yields.

Exome-Based Case-Control Analysis Highlights the Pathogenic Role of Ciliary Genes in Transposition of the Great Arteries.

RATIONALE: Transposition of the great arteries (TGA) is one of the most severe types of congenital heart diseases. Understanding the clinical characteristics and pathogenesis of TGA is, therefore, urgently needed for patient management of this severe disease. However, the clinical characteristics and genetic cause underlying TGA remain largely unexplored. OBJECTIVE: We sought to systematically examine the clinical characteristics and genetic cause for isolated nonsyndromic TGA. METHODS AND RESULTS: We recruited 249 patients with TGA (66 family trios) and performed whole-exome sequencing. The incidence of patent ductus arteriosus in dextro-TGA (52.7%) and dextrocardia/mesocardia in congenitally corrected TGA (32.8%) were significantly higher than that in other subtypes. A high prevalence of bicuspid pulmonic valve (9.6%) was observed in patients with TGA. Similar results were observed in a replication group of TGA (n=132). Through a series of bioinformatics filtering steps, we obtained 82 candidate genes harboring potentially damaging de novo, loss of function, compound heterozygous, or X-linked recessive variants. Established congenital heart disease-causing genes, such as FOXH1, were found among the list of candidate genes. A total of 19 ciliary genes harboring rare potentially damaging variants were also found; for example, DYNC2LI1 with a de novo putatively damaging variant. The enrichment of ciliary genes supports the roles of cilia in the pathogenesis of TGA. In total, 33% of the TGA probands had >1 candidate gene hit by putatively deleterious variants, suggesting that a portion of the TGA cases were probably affected by oligogenic or polygenic inheritance. CONCLUSIONS: The findings of clinical characteristic analyses have important implications for TGA patient stratification. The results of genetic analyses highlight the pathogenic role of ciliary genes and a complex genetic architecture underlying TGA.

Gene expression in human umbilical vein endothelial cells exposed to fine particulate matter: RNA sequencing analysis.

Exposure to airborne particulate matter (PM2.5) is associated with cardiovascular diseases. In order to investigate the molecular mechanisms of air pollution-induced CVDs toxicity, human umbilical vein endothelial cells (HUVECs) were exposed to PM2.5 collected from January, 2016 winter in Beijing, China. We performed RNA sequencing to elucidate key molecular mechanism of PM 2.5-mediated toxicity in HUVECs. A total of 1753 genes, 864 up-regulated and 889 down-regulated, were observed to be differentially expressed genes (DEGs). Among these, genes involved in metabolic response, oxidative stress, inflammatory response, and vascular dysfunction were significantly differentially expressed (log2 FC > 4). The results were validated by quantitative real-time PCR (qPCR) and Western blot for CYP1B1, HMOX1, IL8, and GJA4. Pathway analysis revealed that DEGs were involved in the biological processes related to metabolism, inflammation, and host defense against environmental insults. This research is providing a further understanding of the mechanisms underlying PM2.5-induced cardiovascular diseases (CVDs).

Ab Initio Molecular Dynamics of CdSe Quantum-Dot-Doped Glasses.

We have probed the local atomic structure of the interface between a CdSe quantum dot (QD) and a sodium silicate glass matrix. Using ab initio molecular dynamics simulations, we determined the structural properties and bond lengths, in excellent agreement with previous experimental observations. On the basis of an analysis of radial distribution functions, coordination environment, and ring structures, we demonstrate that an important structural reconstruction occurs at the interface between the CdSe QD and the glass matrix. The incorporation of the CdSe QD disrupts the Na-O bonds, while stronger SiO4 tetrahedra are reformed. The existence of the glass matrix breaks the stable 4-membered (4MR) and 6-membered (6MR) Cd-Se rings, and we observe a disassociated Cd atom migrated in the glass matrix. Besides, the formation of Se-Na and Cd-O linkages is observed at the CdSe QD/glass interface. These results significantly extend our understanding of the interfacial structure of CdSe QD-doped glasses and provide physical and chemical insight into the possible defect structure origin of CdSe QD, of interest to the fabrication of the highly luminescent CdSe QD-doped glasses.

Clinical characteristics and survival of Chinese patients diagnosed with pulmonary arterial hypertension who carry BMPR2 or EIF2KAK4 variants.

BACKGROUND: Variants in the gene encoding bone morphogenetic protein receptor type II (BMPR2) are the most common genetic cause of pulmonary arterial hypertension (PAH), whereas biallelic variants in the eukaryotic translation initiation factor 2 alpha kinase 4 gene (EIF2AK4) are described in pulmonary veno-occlusive disease/pulmonary capillary haemangiomatosis (PVOD/PCH). Racial background may influence the clinical characteristics of patients diagnosed with PAH or PVOD/PCH. Here, we compared the clinical characteristics and survival between patients with BMPR2 variants or EIF2AK4 variants in a Chinese population. METHODS: Heterozygous variants in BMPR2 and homozygous or compound heterozygous biallelic EIF2AK4 variants predicted to be deleterious were identified as potentially causal. Clinical and radiological data were collected and analysed. The primary outcomes were death or lung transplantation. Hazard ratios (HRs) for death or transplantation associated with the presence of BMPR2 or biallelic EIF2AK4 variants were calculated using Cox proportional hazards models to analyse patient survival. RESULTS: Two hundred thirty-two patients with PAH were enrolled for genetic testing, and PAH patients with associated conditions were excluded from the study. Forty-five patients with BMPR2 variants and 11 patients with biallelic EIF2AK4 variants were recruited. PAH patients with BMPR2 or biallelic EIF2AK4 variants presented symptoms at the ages of 25.57 ± 10.17 years and 31.6 ± 9.38 years, respectively. The whole group of patients showed female dominance either with BMPR2 variants or biallelic EIF2AK4 variants. Specific radiological abnormalities are more prominent in EIF2AK4 variant carriers but can also be found in some patients with BMPR2 variants. Biallelic EIF2AK4 variant carriers had worse survival than BMPR2 variant carriers (p < 0.0001). CONCLUSIONS: Clinical pictures of PAH patients with BMPR2 and biallelic EIF2AK4 variants in the Chinese population differ from other populations by a younger age at diagnosis and demonstrate female dominance in the whole patient group. High-resolution chest CT can help assist in differentiating PAH with PVOD/PCH. BMPR2 variants and biallelic EIF2AK4 variants are associated with adverse outcomes, but the survival of patients with biallelic EIF2AK4 variants is dismal.

The co-segregation of the MYL2 R58Q mutation in Chinese hypertrophic cardiomyopathy family and its pathological effect on cardiomyopathy disarray.

Hypertrophic cardiomyopathy (HCM), a major cause of sudden death in youth, is largely affected by genetic factors. The R58Q mutation in the MYL2 gene was identified in some HCM patients and was considered as a deleterious HCM mutation. However, the passing of R58Q between generations along with HCM symptoms was observed only in small families with only two or three members; thus, whether R58Q is as deleterious as previously claimed remains questionable. Here, we reported a large four-generation Chinese family, and found that R58Q existed in all six members with HCM and two healthy juveniles who had not yet developed HCM yet, and presumably in three deceased members who suffered from sudden death. In addition, we also found that compared with other mutations, R58Q had a more severe effect on the cellular level. Therefore, we confirmed that R58Q could be passed from generation to generation along with HCM symptoms and that it was indeed a deleterious mutation for HCM. However, further study is needed to identify additional factors that may determine the various symptoms shown in different family members within the same family.

Two common mutations within CYP2C19 affected platelet aggregation in Chinese patients undergoing PCI: a one-year follow-up study.

The effect of dual antiplatelet therapy, clopidogrel combined with aspirin, was influenced by CYP2C19 gene mutation and heterogeneity of population. Related studies remained controversial and limited, especially in Chinese. Total 3295 unrelated ACS Chinese patients undergoing percutaneous coronary intervention (PCI) were recruited and followed up to 1 year. Meanwhile, baseline and clinical data were retrieved. CYP2C19*2 and *3 were genotyped by sequencing. Associations of variants and metabolic types with platelet reactivity (PR) were analyzed by a logistic regression model. And, a Cox proportional hazards model was utilized to analyze survival data. Confounders included gender, age, smoking status, dosage of aspirin and clopidogrel, and BMI. It was found that patients with allele A in CYP2C19*2 and *3 were susceptibility to high PR (OR, 95%CI and P values were 1.34, 1.20-1.50, <0.0001 and 1.42, 1.13-1.79, 0.0029, respectively) after taking clopidogrel. The PR increased along with the number of loss of function (LOF) allele increased and did in order of haplotype*1, *2, and *3. This research suggested that LOF alleles and risk haplotypes in CYP2C19 could significantly attenuate the response to clopidogrel, which resulted in platelet aggregation.

Secondary findings in 421 whole exome-sequenced Chinese children.

BACKGROUND: Variants with known or possible pathogenicity located in genes that are unrelated to primary disease conditions are defined as secondary findings. Secondary findings are not the primary targets of whole exome and genome sequencing (WES/WGS) assay but can be of great practical value in early disease prevention and intervention. The driving force for this study was to investigate the impact of racial difference and disease background on secondary findings. Here, we analyzed secondary findings frequencies in 421 whole exome-sequenced Chinese children who are phenotypically normal or bear congenital heart diseases/juvenile obesity. In total, 421 WES datasets were processed for potential deleterious variant screening. A reference gene list was defined according to the American College of Medical Genetics and Genomics (ACMG) recommendations for reporting secondary findings v2.0 (ACMG SF v2.0). The variant classification was performed according to the evidence-based guidelines recommended by the joint consensus of the ACMG and the Association for Molecular Pathology (AMP). RESULTS: Among the 421 WES datasets, we identified 11 known/expected pathogenic variants in 12 individuals, accounting for 2.85% of our samples, which is much higher than the reported frequency in a Caucasian population. In conclusion, secondary findings are not so rare in Chinese children, which means that we should pay more attention to the clinical interpretation of sequencing results.

Mitochondrial dysfunction in endothelial cells induced by airborne fine particulate matter (<2.5 µm).

Exposure to ambient fine particulate matter (<2.5 µm; PM2.5 ) increases the risk of the physiopathology of vascular diseases. However, the underlying mechanism, particularly the mitochondrial damage mechanism, of PM2.5 -induced vascular dysfunction is still unclear. In this study, we examined PM2.5 -induced alterations of mitochondrial morphology, and further demonstrated the adverse effects on mitochondrial dynamics and function in vascular endothelial cells. Consequently, cultured EA.hy926 cells were subjected to PM2.5 collected from Beijing. A Cell Counting Assay Kit-8 demonstrated that PM2.5 exposure decreased the proliferation of EA.hy926 cells in a dose-dependent manner. The exposure caused an increment of abnormal mitochondria coupled with the decrease of fusion protein MFN2 and the increase of fission protein FIS1, suggesting that PM2.5 inhibits mitochondrial fusion. Further analyses revealed PM2.5 decreased the mitochondrial membrane potential (ΔΨm) and increased the mitochondrial permeability transport pore opening, eventually resulting in impairments in adenosine triphosphate synthesis. Therefore, it is clearly shown that PM2.5 triggered endothelial toxicity through mitochondria as the target, including the damage of mitochondrial homeostasis.

Genetic analyses in a cohort of 191 pulmonary arterial hypertension patients.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive and fatal disorder associated with high pulmonary artery pressure. Genetic testing enables early diagnosis and offers an opportunity for family screening. To identify genetic mutations and help make a precise diagnosis, we performed genetic testing in 191 probands with PAH and tried to analyze the genotype-phenotype correlation. METHODS: Initially, PAH samples (n = 119) were submitted to BMPR2 screening using Sanger sequencing. Later, we developed a PAH panel test to identify causal mutations in 13 genes related to PAH and tried to call BMPR2 copy number variations (CNVs) with the panel data. Multiplex ligation-dependent probe amplification (MLPA) was used to search for CNVs in BMPR2, ACVRL1 and ENG. Notably, EIF2AK4 gene was also involved in the panel, which allowed to distinguish pulmonary veno-occlusive disease (PVOD)/pulmonary capillary hemangiomatosis (PCH) patients from idiopathic PAH (IPAH). Characteristics of patients were compared using t test for continuous variables. RESULTS: Pathogenic BMPR2 mutations were detected most frequently in 32 (17.9%) IPAH and 5 (41.7%) heritable PAH (HPAH) patients by sequencing, and 12 BMPR2 CNVs called from the panel data were all successfully confirmed by MLPA analysis. In addition, homozygous or compound heterozygous EIF2AK4 mutations were identified in 6 patients, who should be corrected to a diagnosis of PVOD/PCH. Genotype-phenotype correlation analysis revealed that PAH patients with BMPR2 mutations were younger at diagnosis (27.2y vs. 31.6y, p = 0.0003) and exhibited more severe pulmonary hemodynamic impairment and a worse cardiac index compared with those without BMPR2 mutations. CONCLUSIONS: The panel assay represented a highly valuable tool in PAH genetic testing, not only for the detection of small sequence alterations, but also for an indication of BMPR2 CNVs, which had implications for the specific samples to perform further MLPA assay. Analyses of PAH causal genes have a great help to clinical diagnosis and deep implications in disease treatment.

Thrombin Stimulated Platelet-Derived Exosomes Inhibit Platelet-Derived Growth Factor Receptor-Beta Expression in Vascular Smooth Muscle Cells.

BACKGROUND/AIMS: It is difficult to predict acute thrombotic cardiovascular events in the clinic. Few studies have reported the presence of plasma exosomes containing microRNAs (miRNAs) in cardiovascular events. Therefore, we aimed to investigate the levels of miR-223, miR-339 and miR-21 in plasma exosomes before thrombosis in mouse models of carotid tandem stenosis, as well as the mechanisms underlying the origin and function of these exosomal miRNAs. METHODS: Plasma samples were collected from the carotid tandem stenosis and sham control groups of our successfully developed atherothrombosis mouse models before thrombosis. Platelets from healthy volunteers and mice were purified to obtain thrombin stimulated platelet-derived exosomes. Exosomes were isolated via differential ultracentrifugation, and western blotting and transmission electron microscopy were used for their identification. The total RNA was extracted, and quantitative real-time PCR was performed to determine the expression levels of miR-223, miR-339 and miR-21. DAVID Tools were used to analyze the pathways that were enriched among the miRNA target genes. Immuno-fluorescence staining was performed to identify the protein expression levels of platelet-derived exosome target genes in vascular smooth muscle cells (SMCs) in vitro and in vivo. RESULTS: The levels of miR-223, miR-339 and miR-21, which are associated with platelet activation, were elevated in pooled mouse plasma exosomes before thrombosis and enriched in thrombin-stimulated platelet-derived exosomes in vitro. Platelet-derived growth factor receptor-beta (PDGFRß) was a target of these miRNAs, and PDGFRß expression in vascular smooth muscle cells (SMCs) was inhibited following incubation with platelet-derived exosomes. Platelet-derived exosomes could also inhibit PDGF-stimulated SMC proliferation. Furthermore, a decrease in PDGFRß expression was observed in vascular SMCs around thrombotic areas in vivo. CONCLUSIONS: Our data indicate that activated platelet-derived exosomes containing miR-223, miR-339 and miR-21 could be transferred into SMCs and inhibit PDGFRß expression; these exosomal miRNAs may be a biomarker for predicting atherothrombosis.

Lewis Acid-Catalyzed Formal [2π+2σ] Cycloaddition of Bicyclobutanes with Quinoxalin-2(1H)-ones: Access to Quinoxaline-Fused Aza-Bicyclo[2.1.1]hexanes.

An efficient synthesis of quinoxaline-fused aza-bicyclo[2.1.1]hexanes bearing multiple quaternary carbon centers via the intermolecular [2π+2σ] cycloaddition of bicyclo[1.1.0]butanes and quinoxalin-2(1H)-ones, facilitated by Lewis acid catalysis, is presented. This reaction is carried out under mild conditions and exhibits a broad substrate scope and excellent functional group tolerance.