陈前龙

中国医学科学院阜外医院 分子诊断科

Rare loss-of-function variants in matrisome genes are enriched in Ebstein's anomaly.

Ebstein's anomaly, a rare congenital heart disease, is distinguished by the failure of embryological delamination of the tricuspid valve leaflets from the underlying primitive right ventricle myocardium. Gaining insight into the genetic basis of Ebstein's anomaly allows a more precise definition of its pathogenesis. In this study, two distinct cohorts from the Chinese Han population were included: a case-control cohort consisting of 82 unrelated cases and 125 controls without cardiac phenotypes and a trio cohort comprising 36 parent-offspring trios. Whole-exome sequencing data from all 315 participants were utilized to identify qualifying variants, encompassing rare (minor allele frequency < 0.1% from East Asians in the gnomAD database) functional variants and high-confidence (HC) loss-of-function (LoF) variants. Various statistical models, including burden tests and variance-component models, were employed to identify rare variants, genes, and biological pathways associated with Ebstein's anomaly. Significant associations were noted between Ebstein's anomaly and rare HC LoF variants found in genes related to the matrisome, a collection of extracellular matrix (ECM) components. Specifically, 47 genes with HC LoF variants were exclusively or predominantly identified in cases, while nine genes showed such variants in the probands. Over half of unrelated cases (n = 42) and approximately one-third of probands (n = 12) were found to carry one or two LoF variants in these prioritized genes. These results highlight the role of the matrisome in the pathogenesis of Ebstein's anomaly, contributing to a better understanding of the genetic architecture underlying this condition. Our findings hold the potential to impact the genetic diagnosis and treatment approaches for Ebstein's anomaly.

4.4

HGG advances 2024

Molecular characterization and clinical investigation of patients with heritable thoracic aortic aneurysm and dissection.

OBJECTIVES:Thoracic aortic aneurysm and dissection has a genetic predisposition and a variety of clinical manifestations. This study aimed to investigate the clinical and molecular characterizations of patients with thoracic aortic aneurysm and dissection and further explore the relationship between the genotype and phenotype, as well as their postoperative outcomes.METHODS:A total of 1095 individuals with thoracic aortic aneurysm and dissection admitted to our hospital between 2013 and 2022 were included. Next-generation sequencing and multiplex ligation-dependent probe amplification were performed, and mosaicism analysis was additionally implemented to identify the genetic causes.RESULTS:A total of 376 causative variants were identified in 83.5% of patients with syndromic thoracic aortic aneurysm and dissection and 18.7% of patients with nonsyndromic thoracic aortic aneurysm and dissection, including 8 copy number variations and 2 mosaic variants. Patients in the "pathogenic" and "variant of uncertain significance" groups had younger ages of aortic events and higher aortic reintervention risks compared with genetically negative cases. In addition, patients with FBN1 haploinsufficiency variants had shorter reintervention-free survival than those with FBN1 dominant negative variants.CONCLUSIONS:Our data expanded the genetic spectrum of heritable thoracic aortic aneurysm and dissection and indicated that copy number variations and mosaic variants contributed to a small proportion of the disease-causing alterations. Moreover, positive genetic results might have a possible predictive value for aortic event severity and postoperative risk stratification.

6.0
1区

The Journal of thoracic and cardiovascular surgery 2023

Heterozygous nonsense variants in laminin subunit 3α resulting in Ebstein's anomaly.

Ebstein's anomaly is a rare congenital heart disease characterized by tricuspid valve downward displacement and is associated with additional cardiac phenotypes such as left ventricle non-compaction. The genetic basis of Ebstein's anomaly has yet to be fully elucidated, although several genes (e.g., NKX2-5, MYH7, TPM1, and FLNA) may contribute to Ebstein's anomaly. Here, in two Ebstein's anomaly families (a three-generation family and a trio), we identified independent heterozygous nonsense variants in laminin subunit 3 α (LAMA3), cosegregated with phenotypes in families with reduced penetrance. Furthermore, knocking out Lama3 in mice revealed that haploinsufficiency of Lama3 led to Ebstein's malformation of the tricuspid valve and an abnormal basement membrane structure. In conclusion, we identified a novel gene-disease association of LAMA3 implicated in Ebstein's anomaly, and the findings extended our understanding of the role of the extracellular matrix in Ebstein's anomaly etiology.

4.4

HGG advances 2023

P-Selectin Glycoprotein Ligand-1 Deficiency Protects Against Aortic Aneurysm Formation Induced by DOCA Plus Salt.

PURPOSE:P-selectin glycoprotein ligand-1 (PSGL-1) acts as a crucial regulator for the inflammatory cells infiltration by mediating the adhesion of leukocytes. However, the role of PSGL-1 in aortic aneurysm remains elusive. Here, we investigated the role of PSGL-1 in aortic aneurysm (AA) development.METHODS:We first detected PSGL-1 expression in samples from aortic aneurysm patients and mouse AA models via western blotting, immunofluorescence, and flow cytometry, and then we used global PSGL-1 knockout mice and their wild type controls to establish an aortic aneurysm model induced by deoxycorticosterone acetate (DOCA) plus high salt (HS). The incidence, fatality rates, and the pathological changes of aortic aneurysm were analyzed in each group. The inflammation, adhesion molecules expression, and PSGL-1 mediated leukocyte-endothelial adhesion and their underlying mechanisms were explored further.RESULTS:Increased PSGL-1 levels were observed in human and mouse aortic aneurysm, and on leukocytes of mice treated with DOCA+HS. PSGL-1 deficiency reduced the incidence and severity of aortic aneurysm significantly, as well as decreased elastin fragmentation, collagen accumulation, and smooth muscle cells degeneration. Mechanistically, the protective effect of PSGL-1 inhibition was mediated by the reduced adhesion molecules, and the subsequently reduced leukocyte-endothelial adhesion through the NF-κB pathway, which finally led to reduced inflammatory cells infiltration and decreased inflammatory factors expression.CONCLUSION:PSGL-1 deficiency is protective against inflammatory cells migration and recruitment in the condition of AA through attenuation of leukocyte-endothelial adhesion. Inhibition of PSGL-1 may be a potential therapeutic target for the prevention and treatment of human AA.

3.4
3区

Cardiovascular drugs and therapy 2022

Patient-specific and gene-corrected induced pluripotent stem cell-derived endothelial cells elucidate single-cell phenotype of pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension characterized by the preferential remodeling of the pulmonary venules. Hereditary PVOD is caused by biallelic variants of the EIF2AK4 gene. Three PVOD patients who carried the compound heterozygous variants of EIF2AK4 and two healthy controls were recruited and induced pluripotent stem cells (iPSCs) were generated from human peripheral blood mononuclear cells (PBMCs). The EIF2AK4 c.2965C>T variant (PVOD#1), c.3460A>T variant (PVOD#2), and c.4832_4833insAAAG variant (PVOD#3) were corrected by CRISPR-Cas9 in PVOD-iPSCs to generate isogenic controls and gene-corrected-iPSCs (GC-iPSCs). PVOD-iPSC-endothelial cells (ECs) exhibited a decrease in GCN2 protein and mRNA expression when compared with control and GC-ECs. PVOD-ECs exhibited an abnormal EC phenotype featured by excessive proliferation and angiogenesis. The abnormal phenotype of PVOD-ECs was normalized by protein kinase B inhibitors AZD5363 and MK2206. These findings help elucidate the underlying molecular mechanism of PVOD in humans and to identify promising therapeutic drugs for treating the disease.

5.9
2区

Stem cell reports 2022

Metabolomic Profile Reveals That Ceramide Metabolic Disturbance Plays an Important Role in Thoracic Aortic Dissection.

AIMS:Thoracic aortic dissection (TAD) is a life-threatening disease with no effective drug therapy thus far. New therapeutic targets and indications for timely surgical intervention are urgently needed. Our aim is to investigate new pathological mechanisms and potential biomarkers of TAD through global metabolomic profiling of aortic aneurysm and dissection patients.METHODS AND RESULTS:We performed untargeted metabolomics to determine plasma metabolite concentrations in an aortic disease cohort, including 70 thoracic aortic aneurysm (TAA) and 70 TAD patients, as well as 70 healthy controls. Comparative analysis revealed that sphingolipid, especially its core metabolite C18-ceramide, was significantly distinguished in TAD patients but not in TAA patients, which was confirmed by subsequent quantitative analysis of C18-ceramide in a validation cohort. By analyzing our existing multiomics data in aortic tissue in a murine TAD model and TAD patients, we found that an enhanced ceramide de novo synthesis pathway in macrophages might contribute to the elevated ceramide. Inhibition of the ceramide de novo synthesis pathway by myriocin markedly alleviated BAPN-induced aortic inflammation and dissection in mice. In vitro studies demonstrated that exogenous C18-ceramide promoted macrophage inflammation and matrix metalloprotein (MMP) expression through the NLRP3-caspase 1 pathway. In contrast, inhibition of endogenous ceramide synthesis by myriocin attenuated lipopolysaccharide (LPS)-induced macrophage inflammation.CONCLUSIONS:Our findings demonstrated that ceramide metabolism disturbance might play a vital role in TAD development by aggravating aortic inflammation through the NLRP3 pathway, possibly providing a new target for pharmacological therapy and a potential biomarker of TAD.

3.6
3区

Frontiers in cardiovascular medicine 2022

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.

8.8
1区

Genetics in medicine : official journal of the American College of Medical Genetics 2022

Novel LTBP3 mutations associated with thoracic aortic aneurysms and dissections.

BACKGROUND:Thoracic aortic aneurysm and dissection (TAAD) is a hidden-onset but life-threatening disorder with high clinical variability and genetic heterogeneity. In recent years, an increasing number of genes have been identified to be related to TAAD. However, some genes remain uncertain because of limited case reports and/or functional studies. LTBP3 was such an ambiguous gene that was previously known for dental and skeletal dysplasia and then noted to be associated with TAAD. More research on individuals or families harboring variants in this gene would be helpful to obtain full knowledge of the disease and clarify its association with TAAD.METHODS:A total of 266 TAAD probands with no causative mutations in known genes had been performed wholeexome sequencing (WES) to identify potentially pathogenic variants. In this study, rare LTBP3 variants were the focus of analysis.RESULTS:Two compound heterozygous mutations, c.625dup (p.Leu209fs) and c.1965del (p.Arg656fs), in LTBP3 were identified in a TAAD patient along with short stature and dental problems, which was the first TAAD case with biallelic LTBP3 null mutations in an Asian population. Additionally, several rare heterozygous LTBP3 variants were also detected in other sporadic TAAD patients.CONCLUSION:The identification of LTBP3 mutations in TAAD patients in our study provided more clinical evidence to support its association with TAAD, which broadens the gene spectrum of LTBP3. LTBP3 should be considered to be incorporated into the routine genetic analysis of heritable aortopathy, which might help to fully understand its phenotypic spectrum and improve the diagnostic rate of TAAD.

3.7
2区

Orphanet journal of rare diseases 2021

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.

3.1
3区

BMC pulmonary medicine 2020

Transcriptome analysis and functional identification of adipose-derived mesenchymal stem cells in secondary lymphedema.

BACKGROUND:Secondary lymphedema is a common condition that affects patients with malignant tumors. Conservative treatments fail to provide lasting relief because they do not address the underlying pathological accumulation of excessive fat. Our aim is to clarify the molecular mechanisms of abnormal adipogenic differentiation in lymphedema adipose tissue.METHODS:We compared the proliferation and adipogenesis potential of adipose-derived mesenchymal stem cells (ASCs) from the lymphedema adipose tissue from liposuction specimens of 10 patients with extremity lymphedema with that of ASCs from adipose tissue from the normal upper abdomen of the same patients. Transcriptome analysis were performed to identify the differences between the two kinds of ASCs. Cyclin-dependent kinase 1 (CDK1) inhibitors were used to treat the abnormal ASCs in lymphedema adipose tissue.RESULTS:Our results demonstrate that significant functional and transcriptomic differences exist between the two kinds of ASCs. Up-regulated genes were mainly involved in cell proliferation and division while down-regulated genes were mainly associated with immune responses and inflammatory as well as osteogenic and myogenic differentiation. Furthermore, we find that the excessive proliferation and adipogenesis of ASCs from lymphedema adipose tissue returned to the normal phenotype by CDK1 inhibitors. ASCs from lymphedema adipose tissues have higher immunosuppressive effect and the cytokines related to immunosuppressive was significantly up-regulated.CONCLUSIONS:In conclusion, lymphedema-associated ASCs had more rapid proliferation and a higher adipogenic differentiation capacity. CDK1 may be a key driver of proliferation and adipogenic differentiation in these cells, which might expound the accumulation of adipose tissue extensively observed in secondary lymphedema. ASCs from lymphedema adipose tissues showed immunomodulation dysfunction and immunomodulation may play an important role in the pathogenesis of lymphedema.

1.8
3区

Gland surgery 2020