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1.
Prev Med ; 181: 107915, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38408649

ABSTRACT

OBJECTIVE: This study aimed to investigate the potential causal relationship between domain-specific sedentary behaviors (including television watching, computer use, and driving) and hypertension risk in European populations. METHODS: Initially, we conducted a multivariable Cox regression analysis to evaluate the associations between domain-specific sedentary behaviors and the risk of developing hypertension using data from 261,829 hypertension-free participants in the UK Biobank. To validate the findings of observational analysis, we employed two-sample univariable mendelian randomization (UVMR) analysis utilizing summary statistics from genome-wide association study conducted on European populations. We then performed multivariable mendelian randomization (MVMR) analysis to account for the influence of the risk factors for hypertension. RESULTS: In this prospective observational analysis, individuals who spent >3 h per day watching television had significantly higher risk of developing hypertension (HR = 1.24, 95% CI: 1.20-1.29, P < 0.001) compared to those who watched television for 0-1 h per day. The mendelian randomization analysis provided consistent evidence for a causal relationship between prolonged television watching time and hypertension risk (OR = 1.45, 95% CI: 1.25-1.69, P < 0.001; all PMVMR < 0.05) in both UVMR and MVMR results. No significant associations were found between computer use, driving behaviors and the risk of hypertension in either the observational or UVMR/MVMR analyses. CONCLUSIONS: These findings provide evidence for a causal effect specifically linking higher television watching time to an increased risk of hypertension and indicate the potential effectiveness of reducing television viewing time as a preventive measure to mitigate the risk of hypertension.


Subject(s)
Hypertension , Sedentary Behavior , Humans , Mendelian Randomization Analysis , Genome-Wide Association Study , Prospective Studies , Recreation , Hypertension/etiology , Hypertension/genetics , Polymorphism, Single Nucleotide
2.
Adv Sci (Weinh) ; 10(36): e2303913, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37949673

ABSTRACT

Extranodal natural killer/T-cell lymphoma (NKTCL) is an aggressive type of lymphoma associated with Epstein-Barr virus (EBV) and characterized by heterogeneous tumor behaviors. To better understand the origins of the heterogeneity, this study utilizes single-cell RNA sequencing (scRNA-seq) analysis to profile the tumor microenvironment (TME) of NKTCL at the single-cell level. Together with in vitro and in vivo models, the study identifies a subset of LMP1+ malignant NK cells contributing to the tumorigenesis and development of heterogeneous malignant cells in NKTCL. Furthermore, malignant NK cells interact with various immunocytes via chemokines and their receptors, secrete substantial DPP4 that impairs the chemotaxis of immunocytes and regulates their infiltration. They also exhibit an immunosuppressive effect on T cells, which is further boosted by LMP1. Moreover, high transcription of EBV-encoded genes and low infiltration of tumor-associated macrophages (TAMs) are favorable prognostic indicators for NKTCL in multiple patient cohorts. This study for the first time deciphers the heterogeneous composition of NKTCL TME at single-cell resolution, highlighting the crucial role of malignant NK cells with EBV-encoded LMP1 in reshaping the cellular landscape and fostering an immunosuppressive microenvironment. These findings provide insights into understanding the pathogenic mechanisms of NKTCL and developing novel therapeutic strategies against NKTCL.


Subject(s)
Epstein-Barr Virus Infections , Lymphoma, Extranodal NK-T-Cell , Humans , Herpesvirus 4, Human/genetics , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/pathology , Lymphoma, Extranodal NK-T-Cell/genetics , Lymphoma, Extranodal NK-T-Cell/pathology , Prognosis , Single-Cell Analysis , Tumor Microenvironment
3.
Ann Transl Med ; 10(15): 818, 2022 Aug.
Article in English | MEDLINE | ID: mdl-36035003

ABSTRACT

Background: Nonalcoholic fatty liver disease (NAFLD) has been linked to gallstone disease (GSD) in observational studies; however, the relationships between certain lipid profiles and GSD remain unclear. Methods: We adopted a two-sample Mendelian randomization (MR) framework by applying different statistical methods to assess causalities between lipid profiles and GSD. We identified single-nucleotide polymorphisms (SNPs) for blood lipids and NAFLD from separate previous genome-wide association studies (GWASs). Results: We retrieved GSD SNPs attributed to 10,520 cases and 361,194 controls and validated our estimates using GWAS summary data from UK Biobank. We also performed sex-stratified analyses. Based on the summary estimates of 41, 59, 35, and 2 SNPs for low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), triglycerides (TGs), and NAFLD, respectively, we found no evidence of a causal relationship between genetically-predicted lipid profiles and GSD. The odds ratios were 0.995 for LDLC [95% confidence interval (CI): 0.994-0.998] per 0.98 mmol/L, 0.999 for HDLC (95% CI: 0.996-1.003) per 0.41 mmol/L, 0.997 for TGs (95% CI: 0.994-1.001) per 1 mmol/L, and 0.993 for NAFLD (95% CI: 0.984-1.003). No evidence of associations between lipid profile s and GSD in validation MR analyses or the sex-stratification analyses was noted. Conclusions: Genetically predicted hyperlipidemia or NAFLD is not causally associated with GSD.

4.
Clin Chim Acta ; 534: 81-92, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-35810802

ABSTRACT

BACKGROUND AND AIMS: Circulating tumor DNA (ctDNA) has been recognized as a reliable source to reflect the molecular and genetic landscape of corresponding tumors in recent years. In this study, we tested the application of a cancer genomic panel sequencing on the cerebrospinal fluid (CSF)-derived ctDNA for the less invasive detection and diagnosis of glioma. MATERIALS AND METHODS: CtDNA was extracted from 26 CSF samples and subject to a cancer genomic panel sequencing of 520 genes to analyze the mutation profiles and tumor mutation burden (TMB), which were compared with their corresponding tumor DNA samples. Associations between mutations or TMB and clinical characteristics were also evaluated. RESULTS: A high detection rate of ctDNA (24/26, 92.3%) was observed in CSF. CtDNA mutations had high concordance rates with tumor DNA, especially in non-copy number variations and in glioblastoma. CSF ctDNA TMB also exhibited a strong correlation with tumor DNA TMB (R2 = 0.879, P < 0.001), particularly in glioblastoma (R2 = 0.992, P < 0.001). Age was significantly associated with CSF ctDNA TMB in glioma patients. CONCLUSION: We established a less invasive but effective molecular diagnostic approach using a cancer genomic panel sequencing system targeting CSF ctDNA for glioma, especially in glioblastoma.


Subject(s)
Cell-Free Nucleic Acids , Circulating Tumor DNA , Glioblastoma , Glioma , Biomarkers, Tumor/genetics , Circulating Tumor DNA/genetics , DNA, Neoplasm/genetics , Genomics , Glioblastoma/cerebrospinal fluid , Glioblastoma/genetics , Glioblastoma/pathology , Glioma/diagnosis , Glioma/genetics , High-Throughput Nucleotide Sequencing , Humans , Mutation
5.
Am J Hematol ; 97(9): 1159-1169, 2022 09.
Article in English | MEDLINE | ID: mdl-35726449

ABSTRACT

With lowering costs of sequencing and genetic profiling techniques, genetic drivers can now be detected readily in tumors but current prognostic models for Natural-killer/T cell lymphoma (NKTCL) have yet to fully leverage on them for prognosticating patients. Here, we used next-generation sequencing to sequence 260 NKTCL tumors, and trained a genomic prognostic model (GPM) with the genomic mutations and survival data from this retrospective cohort of patients using LASSO Cox regression. The GPM is defined by the mutational status of 13 prognostic genes and is weakly correlated with the risk-features in International Prognostic Index (IPI), Prognostic Index for Natural-Killer cell lymphoma (PINK), and PINK-Epstein-Barr virus (PINK-E). Cox-proportional hazard multivariate regression also showed that the new GPM is independent and significant for both progression-free survival (PFS, HR: 3.73, 95% CI 2.07-6.73; p < .001) and overall survival (OS, HR: 5.23, 95% CI 2.57-10.65; p = .001) with known risk-features of these indices. When we assign an additional risk-score to samples, which are mutant for the GPM, the Harrell's C-indices of GPM-augmented IPI, PINK, and PINK-E improved significantly (p < .001, χ2 test) for both PFS and OS. Thus, we report on how genomic mutational information could steer toward better prognostication of NKTCL patients.


Subject(s)
Epstein-Barr Virus Infections , Lymphoma, Extranodal NK-T-Cell , Disease-Free Survival , Genomics , Herpesvirus 4, Human , Humans , Prognosis , Retrospective Studies
6.
Diabetologia ; 64(9): 2026-2036, 2021 09.
Article in English | MEDLINE | ID: mdl-34023962

ABSTRACT

AIMS/HYPOTHESIS: The study aimed to investigate the effects of HLA class I genes on susceptibility to type 1 diabetes with different onset ages, in addition to the well-established effects of HLA class II genes. METHODS: A total of 361 patients with type 1 diabetes (192 patients with onset <18 years and 169 patients with onset ≥18 years) and 500 healthy control participants from China were enrolled and genotyped for the HLA-A, -B, -C, -DQA1, -DQB1 and -DRB1 genes using next-generation sequencing. RESULTS: The susceptible DR3 (ß = -0.09, p = 0.0009) and DR4-DQ8 (ß = -0.13, p = 0.0059) haplotypes were negatively associated with onset age, while the protective DR11 (ß = 0.21, p = 0.0314) and DR12 (ß = 0.27, p < 0.0001) haplotypes were positively associated with onset age. After adjustment for linkage disequilibrium with DR-DQ haplotypes, A*11:01:01 was positively associated with onset age (ß = 0.06, p = 0.0370), while the susceptible C*15:02:01 was negatively associated with onset age (ß = -0.21, p = 0.0050). The unit for ß was double square-root (fourth root) transformed years of change in onset age associated with per copy of the HLA haplotype/allele. In addition, B*46:01:01 was protective (OR 0.41, 0.46; pc [corrected for multiple comparisons] = 0.0044, 0.0040), whereas A*24:02:01 (OR 2.71, 2.25; pc = 0.0003, 0.0002) and B*54:01:01 (OR 3.96, 3.79; pc = 0.0018, 0.0004) were predisposing in both the <18 group and the ≥18 group compared with healthy control participants. In the context of DR4-DQ4, A*11:01:01 (61.29% vs 28.26%, pc = 0.0144) was increased while the predisposing A*24:02:01 (19.35% vs 47.83%, pc = 0.0403) was decreased in patients with onset ≥18 years when compared with patients with onset <18 years. CONCLUSIONS/INTERPRETATION: In addition to DR-DQ haplotypes, novel HLA class I alleles were detected to play a role in susceptibility to type 1 diabetes with different onset ages, which could improve the understanding of disease heterogeneity and has implications for the design of future studies.


Subject(s)
Diabetes Mellitus, Type 1 , Age of Onset , Alleles , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/genetics , Genes, MHC Class I , Genetic Predisposition to Disease/genetics , HLA-DQ Antigens/genetics , HLA-DQ beta-Chains/genetics , HLA-DRB1 Chains/genetics , Haplotypes/genetics , Humans , Insulin/genetics
7.
Nat Commun ; 12(1): 741, 2021 02 02.
Article in English | MEDLINE | ID: mdl-33531485

ABSTRACT

The heterogeneous nature of tumour microenvironment (TME) underlying diverse treatment responses remains unclear in nasopharyngeal carcinoma (NPC). Here, we profile 176,447 cells from 10 NPC tumour-blood pairs, using single-cell transcriptome coupled with T cell receptor sequencing. Our analyses reveal 53 cell subtypes, including tumour-infiltrating CD8+ T, regulatory T (Treg), and dendritic cells (DCs), as well as malignant cells with different Epstein-Barr virus infection status. Trajectory analyses reveal exhausted CD8+ T and immune-suppressive TNFRSF4+ Treg cells in tumours might derive from peripheral CX3CR1+CD8+ T and naïve Treg cells, respectively. Moreover, we identify immune-regulatory and tolerogenic LAMP3+ DCs. Noteworthily, we observe intensive inter-cell interactions among LAMP3+ DCs, Treg, exhausted CD8+ T, and malignant cells, suggesting potential cross-talks to foster an immune-suppressive niche for the TME. Collectively, our study uncovers the heterogeneity and interacting molecules of the TME in NPC at single-cell resolution, which provide insights into the mechanisms underlying NPC progression and the development of precise therapies for NPC.


Subject(s)
Head and Neck Neoplasms/immunology , Head and Neck Neoplasms/metabolism , Nasopharyngeal Carcinoma/immunology , Nasopharyngeal Carcinoma/metabolism , Tumor Microenvironment/physiology , CD8-Positive T-Lymphocytes/enzymology , CD8-Positive T-Lymphocytes/metabolism , Cells, Cultured , Dendritic Cells/immunology , Dendritic Cells/metabolism , High-Throughput Nucleotide Sequencing , Humans , Male , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Tumor Microenvironment/immunology
8.
Genome Biol ; 21(1): 294, 2020 12 07.
Article in English | MEDLINE | ID: mdl-33287869

ABSTRACT

BACKGROUND: As core units of organ tissues, cells of various types play their harmonious rhythms to maintain the homeostasis of the human body. It is essential to identify the characteristics of cells in human organs and their regulatory networks for understanding the biological mechanisms related to health and disease. However, a systematic and comprehensive single-cell transcriptional profile across multiple organs of a normal human adult is missing. RESULTS: We perform single-cell transcriptomes of 84,363 cells derived from 15 tissue organs of one adult donor and generate an adult human cell atlas. The adult human cell atlas depicts 252 subtypes of cells, including major cell types such as T, B, myeloid, epithelial, and stromal cells, as well as novel COCH+ fibroblasts and FibSmo cells, each of which is distinguished by multiple marker genes and transcriptional profiles. These collectively contribute to the heterogeneity of major human organs. Moreover, T cell and B cell receptor repertoire comparisons and trajectory analyses reveal direct clonal sharing of T and B cells with various developmental states among different tissues. Furthermore, novel cell markers, transcription factors, and ligand-receptor pairs are identified with potential functional regulations in maintaining the homeostasis of human cells among tissues. CONCLUSIONS: The adult human cell atlas reveals the inter- and intra-organ heterogeneity of cell characteristics and provides a useful resource in uncovering key events during the development of human diseases in the context of the heterogeneity of cells and organs.


Subject(s)
Gene Expression Profiling/methods , Transcriptome , Adult , B-Lymphocytes , Fibroblasts/metabolism , Gene Expression , Genetic Heterogeneity , Genetic Markers , Humans , Male , Stromal Cells/metabolism , Transcription Factors/metabolism
9.
Discov Med ; 29(157): 129-137, 2020.
Article in English | MEDLINE | ID: mdl-33002409

ABSTRACT

Sepsis is a life-threatening clinical condition demanding accurate and rapid diagnosis of the culprit pathogen, thereby to improve prognosis. Pathogen determination through blood culture is the gold standard for diagnosis but has limitations due to low sensitivity. Recently, circulating DNAs derived from pathogenic organisms were found in the plasma of patients with sepsis and were further proved to be more sensitive biomarkers for the diagnosis of the pathogen origin in sepsis. However, the fundamental molecular characteristics of circulating DNA in patients with sepsis remain unclear. Here, we used specific PCR and Sanger sequencing to verify the microbiology culture results via the corresponding plasma circulating DNA. We analyzed the composition and molecular characteristics of circulating DNA in septic patients using next-generation sequencing technology. We showed the presence of pathogen-derived circulating DNA in the plasma of patients with sepsis. The sizes of circulating DNA fragments derived from pathogenic bacteria showed a skewed unimodal distribution, while those derived from host cells showed a normal unimodal distribution. Lengths of fragments at peak concentration for both origins ranged from 150 bp to 200 bp, and reads mapping to pathogenic bacteria genome distributed uniformly on the reference. Our findings have improved our understanding of microbial circulating DNA in patients with sepsis as a potential methodology for the accurate diagnosis of sepsis, especially in light of an urgent need for such a diagnosis associated with the COVID-19 infection.


Subject(s)
Bacterial Infections/microbiology , Cell-Free Nucleic Acids/blood , DNA, Bacterial/blood , Sepsis/microbiology , Adult , Aged , Bacterial Infections/complications , Bacterial Infections/diagnosis , Betacoronavirus , COVID-19 , COVID-19 Testing , Cell-Free Nucleic Acids/analysis , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Culture Techniques , DNA, Bacterial/analysis , Female , High-Throughput Nucleotide Sequencing , Humans , Male , Middle Aged , Neoplasms/complications , Pandemics , Pneumonia, Viral , Polymerase Chain Reaction , SARS-CoV-2 , Sepsis/complications , Sepsis/diagnosis , Sequence Analysis, DNA
10.
Adv Sci (Weinh) ; 7(10): 1903727, 2020 May.
Article in English | MEDLINE | ID: mdl-32440486

ABSTRACT

Germline polymorphisms are linked with differential survival outcomes in cancers but are not well studied in nasopharyngeal carcinoma (NPC). Here, a two-phase association study is conducted to discover germline polymorphisms that are associated with the prognosis of NPC. The discovery phase includes two consecutive hospital cohorts of patients with NPC from Southern China. Exome-wide genotypes at 246 173 single nucleotide polymorphisms (SNPs) are determined, followed by survival analysis for each SNP under Cox proportional hazard regression model. Candidate SNP is replicated in another two independent cohorts from Southern China and Singapore. Meta-analysis of all samples (n = 5553) confirms that the presence of rs1131636-T, located in the 3'-UTR of RPA1, confers an inferior overall survival (HR = 1.33, 95% CI = 1.20-1.47, P = 6.31 × 10-8). Bioinformatics and biological assays show that rs1131636 has regulatory effects on upstream RPA1. Functional studies further demonstrate that RPA1 promotes the growth, invasion, migration, and radioresistance of NPC cells. Additionally, miR-1253 is identified as a suppressor for RPA1 expression, likely through regulation of its binding affinity to rs1131636 locus. Collectively, these findings provide a promising biomarker aiding in stratifying patients with poor survival, as well as a potential drug target for NPC.

11.
Lancet Oncol ; 21(2): 306-316, 2020 02.
Article in English | MEDLINE | ID: mdl-31879220

ABSTRACT

BACKGROUND: Extranodal natural killer T-cell lymphoma (NKTCL; nasal type) is an aggressive malignancy with a particularly high prevalence in Asian and Latin American populations. Epstein-Barr virus infection has a role in the pathogenesis of NKTCL, and HLA-DPB1 variants are risk factors for the disease. We aimed to identify additional novel genetic variants affecting risk of NKTCL. METHODS: We did a genome-wide association study of NKTCL in multiple populations from east Asia. We recruited a discovery cohort of 700 cases with NKTCL and 7752 controls without NKTCL of Han Chinese ancestry from 19 centres in southern, central, and northern regions of China, and four independent replication samples including 717 cases and 12 650 controls. Three of these independent samples (451 cases and 5301 controls) were from eight centres in the same regions of southern, central, and northern China, and the fourth (266 cases and 7349 controls) was from 11 centres in Hong Kong, Taiwan, Singapore, and South Korea. All cases had primary NKTCL that was confirmed histopathologically, and matching with controls was based on geographical region and self-reported ancestry. Logistic regression analysis was done independently by geographical regions, followed by fixed-effect meta-analyses, to identify susceptibility loci. Bioinformatic approaches, including expression quantitative trait loci, binding motif and transcriptome analyses, and biological experiments were done to fine-map and explore the functional relevance of genome-wide association loci to the development of NKTCL. FINDINGS: Genetic data were gathered between Jan 1, 2008, and Jan 23, 2019. Meta-analysis of all samples (a total of 1417 cases and 20 402 controls) identified two novel loci significantly associated with NKTCL: IL18RAP on 2q12.1 (rs13015714; p=2·83 × 10-16; odds ratio 1·39 [95% CI 1·28-1·50]) and HLA-DRB1 on 6p21.3 (rs9271588; 9·35 × 10-26 1·53 [1·41-1·65]). Fine-mapping and experimental analyses showed that rs1420106 at the promoter of IL18RAP was highly correlated with rs13015714, and the rs1420106-A risk variant had an upregulatory effect on IL18RAP expression. Cell growth assays in two NKTCL cell lines (YT and SNK-6 cells) showed that knockdown of IL18RAP inhibited cell proliferation by cell cycle arrest in NKTCL cells. Haplotype association analysis showed that haplotype 47F-67I was associated with reduced risk of NKTCL, whereas 47Y-67L was associated with increased risk of NKTCL. These two positions are component parts of the peptide-binding pocket 7 (P7) of the HLA-DR heterodimer, suggesting that these alterations might account for the association at HLA-DRB1, independent of the previously reported HLA-DPB1 variants. INTERPRETATION: Our findings provide new insights into the development of NKTCL by showing the importance of inflammation and immune regulation through the IL18-IL18RAP axis and antigen presentation involving HLA-DRB1, which might help to identify potential therapeutic targets. Taken in combination with additional genetic and other risk factors, our results could potentially be used to stratify people at high risk of NKTCL for targeted prevention. FUNDING: Guangdong Innovative and Entrepreneurial Research Team Program, National Natural Science Foundation of China, National Program for Support of Top-Notch Young Professionals, Chang Jiang Scholars Program, Singapore Ministry of Health's National Medical Research Council, Tanoto Foundation, National Research Foundation Singapore, Chang Gung Memorial Hospital, Recruitment Program for Young Professionals of China, First Affiliated Hospital and Army Medical University, US National Institutes of Health, and US National Cancer Institute.


Subject(s)
Biomarkers, Tumor/genetics , Cell Proliferation , Interleukin-18 Receptor beta Subunit/genetics , Lymphoma, Extranodal NK-T-Cell/genetics , Natural Killer T-Cells/pathology , Asia , Biomarkers, Tumor/metabolism , Case-Control Studies , Cell Line, Tumor , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Interleukin-18/metabolism , Interleukin-18 Receptor beta Subunit/metabolism , Linkage Disequilibrium , Lymphoma, Extranodal NK-T-Cell/immunology , Lymphoma, Extranodal NK-T-Cell/metabolism , Lymphoma, Extranodal NK-T-Cell/pathology , Natural Killer T-Cells/immunology , Natural Killer T-Cells/metabolism , Phenotype , Prognosis , Quantitative Trait Loci , Risk Assessment , Risk Factors , Signal Transduction , Transcriptome
12.
Biochim Biophys Acta Mol Basis Dis ; 1863(6): 1492-1499, 2017 06.
Article in English | MEDLINE | ID: mdl-28433711

ABSTRACT

Voltage-gated sodium channel α-subunit type I (NaV1.1, encoded by SCN1A gene) plays a critical role in the excitability of brain. Downregulation of SCN1A expression is associated with epilepsy, a common neurological disorder characterized by recurrent seizures. Here we reveal a novel role of malate dehydrogenase 2 (MDH2) in the posttranscriptional regulation of SCN1A expression under seizure condition. We identified that MDH2 was an RNA binding protein that could bind two of the four conserved regions in the 3' UTRs of SCN1A. We further showed that knockdown of MDH2 or inactivation of MDH2 activity in HEK-293 cells increased the reporter gene expression through the 3' UTR of SCN1A, and MDH2 overexpression decreased gene expression by affecting mRNA stability. In the hippocampus of seizure mice, the upregulation of MDH2 expression contributed to the decrease of the NaV1.1 levels at posttranscriptional level. In addition, we showed that the H2O2 levels increased in the hippocampus of the seizure mice, and H2O2 could promote the binding of MDH2 to the binding sites of Scn1a gene, whereas ß-mercaptoethanol decreased the binding capability, indicating an important effect of the seizure-induced oxidation on the MDH2-mediated downregulation of Scn1a expression. Taken together, these data suggest that MDH2, functioning as an RNA-binding protein, is involved in the posttranscriptional downregulation of SCN1A expression under seizure condition.


Subject(s)
3' Untranslated Regions , Down-Regulation , Malate Dehydrogenase/metabolism , NAV1.1 Voltage-Gated Sodium Channel/biosynthesis , RNA-Binding Proteins/metabolism , Seizures/metabolism , Animals , HEK293 Cells , Hippocampus/metabolism , Hippocampus/pathology , Humans , Malate Dehydrogenase/genetics , Mice , NAV1.1 Voltage-Gated Sodium Channel/genetics , RNA-Binding Proteins/genetics , Seizures/genetics , Seizures/pathology
13.
Mol Neurobiol ; 54(4): 2831-2842, 2017 05.
Article in English | MEDLINE | ID: mdl-27013471

ABSTRACT

Upregulation of sodium channel SCN3A expression in epileptic tissues is known to contribute to enhancing neuronal excitability and the development of epilepsy. Therefore, certain strategies to reduce SCN3A expression may be helpful for seizure control. Here, we reveal a novel role of valproate (VPA) in the epigenetic downregulation of Scn3a expression. We found that VPA, instead of carbamazepine (CBZ) and lamotrigine (LTG), could significantly downregulate Scn3a expression in mouse Neuro-2a cells. Luciferase assays and CpG methylation analyses showed that VPA induced the methylation at the -39C site in Scn3a promoter which decreased the promoter activity. We further showed that VPA downregulated the expression of methyl-CpG-binding domain protein 2 (MBD2) at the posttranscriptional level and knockdown of MBD2 increased Scn3a expression. In addition, we found that VPA induced the expression of fat mass and obesity-associated (FTO) protein and FTO knockdown abolished the repressive effects of VPA on MBD2 and Nav1.3 expressions. Furthermore, VPA, instead of other two anticonvulsant drugs, induced the expressions of Scn3a and Mbd2 and reduced Fto expression in the hippocampus of VPA-treated seizure mice. Taken together, this study suggests an epigenetic pathway for the VPA-induced downregulation of Scn3a expression, which provides a possible role of this pathway in the anticonvulsant action of VPA.


Subject(s)
Anticonvulsants/pharmacology , Down-Regulation/genetics , Epigenesis, Genetic/drug effects , NAV1.3 Voltage-Gated Sodium Channel/genetics , Valproic Acid/pharmacology , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism , Animals , Anticonvulsants/therapeutic use , Cell Line, Tumor , CpG Islands/genetics , DNA Methylation/drug effects , DNA Methylation/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Down-Regulation/drug effects , Genes, Reporter , Hippocampus/metabolism , Male , Mice , Models, Biological , NAV1.3 Voltage-Gated Sodium Channel/metabolism , Promoter Regions, Genetic , RNA, Messenger/genetics , RNA, Messenger/metabolism , Seizures/drug therapy , Seizures/genetics , Transcription, Genetic/drug effects , Valproic Acid/therapeutic use
14.
Neuropharmacology ; 113(Pt A): 480-489, 2017 02.
Article in English | MEDLINE | ID: mdl-27816501

ABSTRACT

Abnormal expressions of sodium channel SCN1A and SCN3A genes alter neural excitability that are believed to contribute to the pathogenesis of epilepsy, a long-term risk of recurrent seizures. Ketogenic diet (KD), a high-fat and low-carbohydrate treatment for difficult-to-control (refractory) epilepsy in children, has been suggested to reverse gene expression patterns. Here, we reveal a novel role of GAPDH on the posttranscriptional regulation of mouse Scn1a and Scn3a expressions under seizure and KD conditions. We show that GAPDH binds to a conserved region in the 3' UTRs of human and mouse SCN1A and SCN3A genes, which decreases and increases genes' expressions by affecting mRNA stability through SCN1A 3' UTR and SCN3A 3' UTR, respectively. In seizure mice, the upregulation and phosphorylation of GAPDH enhance its binding to the 3' UTR, which lead to downregulation of Scn1a and upregulation of Scn3a. Furthermore, administration of KD generates ß-hydroxybutyric acid which rescues the abnormal expressions of Scn1a and Scn3a by weakening the GAPDH's binding to the element. Taken together, these data suggest that GAPDH-mediated expression regulation of sodium channel genes may be associated with epilepsy and the anticonvulsant action of KD.


Subject(s)
Diet, Ketogenic , Glyceraldehyde-3-Phosphate Dehydrogenases/physiology , NAV1.1 Voltage-Gated Sodium Channel/genetics , NAV1.3 Voltage-Gated Sodium Channel/genetics , Seizures/diet therapy , Seizures/genetics , Sodium Channels/genetics , Animals , Cell Line, Tumor , Diet, Ketogenic/methods , HEK293 Cells , Humans , Male , Mice , NAV1.1 Voltage-Gated Sodium Channel/biosynthesis , NAV1.3 Voltage-Gated Sodium Channel/biosynthesis , Protein Binding/physiology , RNA Processing, Post-Transcriptional/physiology , Seizures/metabolism , Sodium Channels/biosynthesis
15.
Hum Mutat ; 36(6): 573-80, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25754450

ABSTRACT

Mutations in the SCN1A gene have been identified in epilepsy patients with widely variable phenotypes and modes of inheritance and in asymptomatic carriers. This raises challenges in evaluating the pathogenicity of SCN1A mutations. We systematically reviewed all SCN1A mutations and established a database containing information on functional alterations. In total, 1,257 mutations have been identified, of which 81.8% were not recurrent. There was a negative correlation between phenotype severity and missense mutation frequency. Further analyses suggested close relationships among genotype, functional alteration, and phenotype. Missense mutations located in different sodium channel regions were associated with distinct functional changes. Missense mutations in the pore region were characterized by the complete loss of function, similar to haploinsufficiency. Mutations with severe phenotypes were more frequently located in the pore region, suggesting that functional alterations are critical in evaluating pathogenicity and can be applied to patient management. A negative correlation was found between phenotype severity and familial incidence, and incomplete penetrance was associated with missense and splice site mutations, but not truncations or genomic rearrangements, suggesting clinical genetic counseling applications. Mosaic mutations with a load of 12.5-25.0% were potentially pathogenic with low penetrance, suggesting the need for future studies on less pathogenic genomic variations.


Subject(s)
Databases, Genetic , Mutation , NAV1.1 Voltage-Gated Sodium Channel/genetics , Epilepsy/genetics , Family , Genetic Association Studies/methods , Genotype , Humans , Inheritance Patterns , Mosaicism , Mutation, Missense , Phenotype
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