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1.
Cell ; 185(18): 3375-3389.e21, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35998627

ABSTRACT

Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving multiple immune cells. To elucidate SLE pathogenesis, it is essential to understand the dysregulated gene expression pattern linked to various clinical statuses with a high cellular resolution. Here, we conducted a large-scale transcriptome study with 6,386 RNA sequencing data covering 27 immune cell types from 136 SLE and 89 healthy donors. We profiled two distinct cell-type-specific transcriptomic signatures: disease-state and disease-activity signatures, reflecting disease establishment and exacerbation, respectively. We then identified candidate biological processes unique to each signature. This study suggested the clinical value of disease-activity signatures, which were associated with organ involvement and therapeutic responses. However, disease-activity signatures were less enriched around SLE risk variants than disease-state signatures, suggesting that current genetic studies may not well capture clinically vital biology. Together, we identified comprehensive gene signatures of SLE, which will provide essential foundations for future genomic and genetic studies.


Subject(s)
Lupus Erythematosus, Systemic , Transcriptome , Humans , Lupus Erythematosus, Systemic/genetics , Sequence Analysis, RNA
2.
Nature ; 627(8003): 347-357, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38374256

ABSTRACT

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P < 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.


Subject(s)
Diabetes Mellitus, Type 2 , Disease Progression , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Adipocytes/metabolism , Chromatin/genetics , Chromatin/metabolism , Coronary Artery Disease/complications , Coronary Artery Disease/genetics , Diabetes Mellitus, Type 2/classification , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/pathology , Diabetes Mellitus, Type 2/physiopathology , Diabetic Nephropathies/complications , Diabetic Nephropathies/genetics , Endothelial Cells/metabolism , Enteroendocrine Cells , Epigenomics , Genetic Predisposition to Disease/genetics , Islets of Langerhans/metabolism , Multifactorial Inheritance/genetics , Peripheral Arterial Disease/complications , Peripheral Arterial Disease/genetics , Single-Cell Analysis
3.
Nature ; 628(8006): 130-138, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38448586

ABSTRACT

Genome-wide association analyses using high-throughput metabolomics platforms have led to novel insights into the biology of human metabolism1-7. This detailed knowledge of the genetic determinants of systemic metabolism has been pivotal for uncovering how genetic pathways influence biological mechanisms and complex diseases8-11. Here we present a genome-wide association study for 233 circulating metabolic traits quantified by nuclear magnetic resonance spectroscopy in up to 136,016 participants from 33 cohorts. We identify more than 400 independent loci and assign probable causal genes at two-thirds of these using manual curation of plausible biological candidates. We highlight the importance of sample and participant characteristics that can have significant effects on genetic associations. We use detailed metabolic profiling of lipoprotein- and lipid-associated variants to better characterize how known lipid loci and novel loci affect lipoprotein metabolism at a granular level. We demonstrate the translational utility of comprehensively phenotyped molecular data, characterizing the metabolic associations of intrahepatic cholestasis of pregnancy. Finally, we observe substantial genetic pleiotropy for multiple metabolic pathways and illustrate the importance of careful instrument selection in Mendelian randomization analysis, revealing a putative causal relationship between acetone and hypertension. Our publicly available results provide a foundational resource for the community to examine the role of metabolism across diverse diseases.


Subject(s)
Biomarkers , Genome-Wide Association Study , Metabolomics , Female , Humans , Pregnancy , Acetone/blood , Acetone/metabolism , Biomarkers/blood , Biomarkers/metabolism , Cholestasis, Intrahepatic/blood , Cholestasis, Intrahepatic/genetics , Cholestasis, Intrahepatic/metabolism , Cohort Studies , Genome-Wide Association Study/methods , Hypertension/blood , Hypertension/genetics , Hypertension/metabolism , Lipoproteins/genetics , Lipoproteins/metabolism , Magnetic Resonance Spectroscopy , Mendelian Randomization Analysis , Metabolic Networks and Pathways/genetics , Phenotype , Polymorphism, Single Nucleotide/genetics , Pregnancy Complications/blood , Pregnancy Complications/genetics , Pregnancy Complications/metabolism
4.
Nature ; 610(7933): 704-712, 2022 10.
Article in English | MEDLINE | ID: mdl-36224396

ABSTRACT

Common single-nucleotide polymorphisms (SNPs) are predicted to collectively explain 40-50% of phenotypic variation in human height, but identifying the specific variants and associated regions requires huge sample sizes1. Here, using data from a genome-wide association study of 5.4 million individuals of diverse ancestries, we show that 12,111 independent SNPs that are significantly associated with height account for nearly all of the common SNP-based heritability. These SNPs are clustered within 7,209 non-overlapping genomic segments with a mean size of around 90 kb, covering about 21% of the genome. The density of independent associations varies across the genome and the regions of increased density are enriched for biologically relevant genes. In out-of-sample estimation and prediction, the 12,111 SNPs (or all SNPs in the HapMap 3 panel2) account for 40% (45%) of phenotypic variance in populations of European ancestry but only around 10-20% (14-24%) in populations of other ancestries. Effect sizes, associated regions and gene prioritization are similar across ancestries, indicating that reduced prediction accuracy is likely to be explained by linkage disequilibrium and differences in allele frequency within associated regions. Finally, we show that the relevant biological pathways are detectable with smaller sample sizes than are needed to implicate causal genes and variants. Overall, this study provides a comprehensive map of specific genomic regions that contain the vast majority of common height-associated variants. Although this map is saturated for populations of European ancestry, further research is needed to achieve equivalent saturation in other ancestries.


Subject(s)
Body Height , Chromosome Mapping , Polymorphism, Single Nucleotide , Humans , Body Height/genetics , Gene Frequency/genetics , Genome, Human/genetics , Genome-Wide Association Study , Haplotypes/genetics , Linkage Disequilibrium/genetics , Polymorphism, Single Nucleotide/genetics , Europe/ethnology , Sample Size , Phenotype
5.
Am J Hum Genet ; 110(1): 44-57, 2023 01 05.
Article in English | MEDLINE | ID: mdl-36608684

ABSTRACT

Integrative genetic association methods have shown great promise in post-GWAS (genome-wide association study) analyses, in which one of the most challenging tasks is identifying putative causal genes and uncovering molecular mechanisms of complex traits. Recent studies suggest that prevailing computational approaches, including transcriptome-wide association studies (TWASs) and colocalization analysis, are individually imperfect, but their joint usage can yield robust and powerful inference results. This paper presents INTACT, a computational framework to integrate probabilistic evidence from these distinct types of analyses and implicate putative causal genes. This procedure is flexible and can work with a wide range of existing integrative analysis approaches. It has the unique ability to quantify the uncertainty of implicated genes, enabling rigorous control of false-positive discoveries. Taking advantage of this highly desirable feature, we further propose an efficient algorithm, INTACT-GSE, for gene set enrichment analysis based on the integrated probabilistic evidence. We examine the proposed computational methods and illustrate their improved performance over the existing approaches through simulation studies. We apply the proposed methods to analyze the multi-tissue eQTL data from the GTEx project and eight large-scale complex- and molecular-trait GWAS datasets from multiple consortia and the UK Biobank. Overall, we find that the proposed methods markedly improve the existing putative gene implication methods and are particularly advantageous in evaluating and identifying key gene sets and biological pathways underlying complex traits.


Subject(s)
Genome-Wide Association Study , Transcriptome , Humans , Transcriptome/genetics , Genome-Wide Association Study/methods , Multifactorial Inheritance/genetics , Quantitative Trait Loci/genetics , Computer Simulation , Polymorphism, Single Nucleotide/genetics , Genetic Predisposition to Disease
6.
Am J Hum Genet ; 110(2): 284-299, 2023 02 02.
Article in English | MEDLINE | ID: mdl-36693378

ABSTRACT

Insulin secretion is critical for glucose homeostasis, and increased levels of the precursor proinsulin relative to insulin indicate pancreatic islet beta-cell stress and insufficient insulin secretory capacity in the setting of insulin resistance. We conducted meta-analyses of genome-wide association results for fasting proinsulin from 16 European-ancestry studies in 45,861 individuals. We found 36 independent signals at 30 loci (p value < 5 × 10-8), which validated 12 previously reported loci for proinsulin and ten additional loci previously identified for another glycemic trait. Half of the alleles associated with higher proinsulin showed higher rather than lower effects on glucose levels, corresponding to different mechanisms. Proinsulin loci included genes that affect prohormone convertases, beta-cell dysfunction, vesicle trafficking, beta-cell transcriptional regulation, and lysosomes/autophagy processes. We colocalized 11 proinsulin signals with islet expression quantitative trait locus (eQTL) data, suggesting candidate genes, including ARSG, WIPI1, SLC7A14, and SIX3. The NKX6-3/ANK1 proinsulin signal colocalized with a T2D signal and an adipose ANK1 eQTL signal but not the islet NKX6-3 eQTL. Signals were enriched for islet enhancers, and we showed a plausible islet regulatory mechanism for the lead signal in the MADD locus. These results show how detailed genetic studies of an intermediate phenotype can elucidate mechanisms that may predispose one to disease.


Subject(s)
Diabetes Mellitus, Type 2 , Proinsulin , Humans , Proinsulin/genetics , Proinsulin/metabolism , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Genome-Wide Association Study/methods , Insulin/genetics , Insulin/metabolism , Glucose , Transcription Factors/genetics , Homeodomain Proteins/genetics
7.
Am J Hum Genet ; 109(10): 1727-1741, 2022 10 06.
Article in English | MEDLINE | ID: mdl-36055244

ABSTRACT

Transcriptomics data have been integrated with genome-wide association studies (GWASs) to help understand disease/trait molecular mechanisms. The utility of metabolomics, integrated with transcriptomics and disease GWASs, to understand molecular mechanisms for metabolite levels or diseases has not been thoroughly evaluated. We performed probabilistic transcriptome-wide association and locus-level colocalization analyses to integrate transcriptomics results for 49 tissues in 706 individuals from the GTEx project, metabolomics results for 1,391 plasma metabolites in 6,136 Finnish men from the METSIM study, and GWAS results for 2,861 disease traits in 260,405 Finnish individuals from the FinnGen study. We found that genetic variants that regulate metabolite levels were more likely to influence gene expression and disease risk compared to the ones that do not. Integrating transcriptomics with metabolomics results prioritized 397 genes for 521 metabolites, including 496 previously identified gene-metabolite pairs with strong functional connections and suggested 33.3% of such gene-metabolite pairs shared the same causal variants with genetic associations of gene expression. Integrating transcriptomics and metabolomics individually with FinnGen GWAS results identified 1,597 genes for 790 disease traits. Integrating transcriptomics and metabolomics jointly with FinnGen GWAS results helped pinpoint metabolic pathways from genes to diseases. We identified putative causal effects of UGT1A1/UGT1A4 expression on gallbladder disorders through regulating plasma (E,E)-bilirubin levels, of SLC22A5 expression on nasal polyps and plasma carnitine levels through distinct pathways, and of LIPC expression on age-related macular degeneration through glycerophospholipid metabolic pathways. Our study highlights the power of integrating multiple sets of molecular traits and GWAS results to deepen understanding of disease pathophysiology.


Subject(s)
Genome-Wide Association Study , Transcriptome , Bilirubin , Carnitine , Glycerophospholipids , Humans , Male , Metabolomics , Quantitative Trait Loci/genetics , Solute Carrier Family 22 Member 5/genetics , Transcriptome/genetics
9.
Nature ; 572(7769): 323-328, 2019 08.
Article in English | MEDLINE | ID: mdl-31367044

ABSTRACT

Exome-sequencing studies have generally been underpowered to identify deleterious alleles with a large effect on complex traits as such alleles are mostly rare. Because the population of northern and eastern Finland has expanded considerably and in isolation following a series of bottlenecks, individuals of these populations have numerous deleterious alleles at a relatively high frequency. Here, using exome sequencing of nearly 20,000 individuals from these regions, we investigate the role of rare coding variants in clinically relevant quantitative cardiometabolic traits. Exome-wide association studies for 64 quantitative traits identified 26 newly associated deleterious alleles. Of these 26 alleles, 19 are either unique to or more than 20 times more frequent in Finnish individuals than in other Europeans and show geographical clustering comparable to Mendelian disease mutations that are characteristic of the Finnish population. We estimate that sequencing studies of populations without this unique history would require hundreds of thousands to millions of participants to achieve comparable association power.


Subject(s)
Exome Sequencing , Genetic Association Studies/methods , Genetic Predisposition to Disease/genetics , Genetic Variation/genetics , Quantitative Trait Loci/genetics , Alleles , Cholesterol, HDL/genetics , Cluster Analysis , Endpoint Determination , Finland , Geographic Mapping , Humans , Multifactorial Inheritance/genetics , Reproducibility of Results
10.
Diabetologia ; 66(8): 1472-1480, 2023 08.
Article in English | MEDLINE | ID: mdl-37280435

ABSTRACT

AIMS/HYPOTHESIS: Determining how high BMI at different time points influences the risk of developing type 2 diabetes and affects insulin secretion and insulin sensitivity is critical. METHODS: By estimating childhood BMI in 441,761 individuals in the UK Biobank, we identified which genetic variants had larger effects on adulthood BMI than on childhood BMI, and vice versa. All genome-wide significant genetic variants were then used to separate the independent genetic effects of high childhood BMI from those of high adulthood BMI on the risk of type 2 diabetes and insulin-related phenotypes using Mendelian randomisation. We performed two-sample MR using external studies of type 2 diabetes, and oral and intravenous measures of insulin secretion and sensitivity. RESULTS: We found that a childhood BMI that was one standard deviation (1.97 kg/m2) higher than the mean, corrected for the independent genetic liability to adulthood BMI, was associated with a protective effect for seven measures of insulin sensitivity and secretion, including increased insulin sensitivity index (ß=0.15; 95% CI 0.067, 0.225; p=2.79×10-4) and reduced fasting glucose levels (ß=-0.053; 95% CI -0.089, -0.017; p=4.31×10-3). However, there was little to no evidence of a direct protective effect on type 2 diabetes (OR 0.94; 95% CI 0.85, 1.04; p=0.228) independently of genetic liability to adulthood BMI. CONCLUSIONS/INTERPRETATION: Our results provide evidence of the protective effect of higher childhood BMI on insulin secretion and sensitivity, which are crucial intermediate diabetes traits. However, we stress that our results should not currently lead to any change in public health or clinical practice, given the uncertainty regarding the biological pathway of these effects and the limitations of this type of study.


Subject(s)
Diabetes Mellitus, Type 2 , Insulin Resistance , Humans , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Insulin Resistance/genetics , Body Mass Index , Phenotype , Insulin/genetics , Mendelian Randomization Analysis , Genome-Wide Association Study , Polymorphism, Single Nucleotide
11.
J Neurol Neurosurg Psychiatry ; 94(7): 526-531, 2023 07.
Article in English | MEDLINE | ID: mdl-36732044

ABSTRACT

BACKGROUND: There are currently no specific biomarkers for multiple sclerosis (MS). Identifying robust biomarkers for MS is crucial to improve disease diagnosis and management. METHODS: This study first used six Mendelian randomisation methods to assess causal relationship of 174 metabolites with MS, incorporating data from European-ancestry metabolomics (n=8569-86 507) and MS (n=14 802 MS cases, 26 703 controls) genomewide association studies. Genetic scores for identified causal metabolite(s) were then computed to predict MS disability progression in an independent longitudinal cohort (AusLong study) of 203 MS cases with up to 15-year follow-up. RESULTS: We found a novel genetic causal effect of serine on MS onset (OR=1.67, 95% CI 1.51 to 1.84, p=1.73×10-20), such that individuals whose serine level is 1 SD above the population mean will have 1.67 times the risk of developing MS. This is robust across all sensitivity methods (OR ranges from 1.49 to 1.67). In an independent longitudinal MS cohort, we then constructed time-dynamic and time-fixed genetic scores based on serine genetic instrument single-nucleotide polymorphisms, where higher scores for raised serum serine level were associated with increased risk of disability worsening, especially in the time-dynamic model (RR=1.25, 95% CI 1.10 to 1.42, p=7.52×10-4). CONCLUSIONS: These findings support investigating serine as an important candidate biomarker for MS onset and disability progression.


Subject(s)
Disabled Persons , Multiple Sclerosis , Humans , Multiple Sclerosis/diagnosis , Multiple Sclerosis/genetics , Causality , Metabolomics , Biomarkers , Disease Progression
12.
Ann Rheum Dis ; 2022 May 24.
Article in English | MEDLINE | ID: mdl-35609976

ABSTRACT

OBJECTIVE: Genome-wide association studies (GWAS) have identified >100 risk loci for systemic lupus erythematosus (SLE), but the disease genes at most loci remain unclear, hampering translation of these genetic discoveries. We aimed to prioritise genes underlying the 110 SLE loci that were identified in the latest East Asian GWAS meta-analysis. METHODS: We built gene expression predictive models in blood B cells, CD4+ and CD8+ T cells, monocytes, natural killer cells and peripheral blood cells of 105 Japanese individuals. We performed a transcriptome-wide association study (TWAS) using data from the latest genome-wide association meta-analysis of 208 370 East Asians and searched for candidate genes using TWAS and three data-driven computational approaches. RESULTS: TWAS identified 171 genes for SLE (p<1.0×10-5); 114 (66.7%) showed significance only in a single cell type; 127 (74.3%) were in SLE GWAS loci. TWAS identified a strong association between CD83 and SLE (p<7.7×10-8). Meta-analysis of genetic associations in the existing 208 370 East Asian and additional 1498 cases and 3330 controls found a novel single-variant association at rs72836542 (OR=1.11, p=4.5×10-9) around CD83. For the 110 SLE loci, we identified 276 gene candidates, including 104 genes at recently-identified SLE novel loci. We demonstrated in vitro that putative causal variant rs61759532 exhibited an allele-specific regulatory effect on ACAP1, and that presence of the SLE risk allele decreased ACAP1 expression. CONCLUSIONS: Cell-level TWAS in six types of immune cells complemented SLE gene discovery and guided the identification of novel genetic associations. The gene findings shed biological insights into SLE genetic associations.

13.
Ann Rheum Dis ; 80(5): 632-640, 2021 05.
Article in English | MEDLINE | ID: mdl-33272962

ABSTRACT

OBJECTIVE: Systemic lupus erythematosus (SLE), an autoimmune disorder, has been associated with nearly 100 susceptibility loci. Nevertheless, these loci only partially explain SLE heritability and their putative causal variants are rarely prioritised, which make challenging to elucidate disease biology. To detect new SLE loci and causal variants, we performed the largest genome-wide meta-analysis for SLE in East Asian populations. METHODS: We newly genotyped 10 029 SLE cases and 180 167 controls and subsequently meta-analysed them jointly with 3348 SLE cases and 14 826 controls from published studies in East Asians. We further applied a Bayesian statistical approach to localise the putative causal variants for SLE associations. RESULTS: We identified 113 genetic regions including 46 novel loci at genome-wide significance (p<5×10-8). Conditional analysis detected 233 association signals within these loci, which suggest widespread allelic heterogeneity. We detected genome-wide associations at six new missense variants. Bayesian statistical fine-mapping analysis prioritised the putative causal variants to a small set of variants (95% credible set size ≤10) for 28 association signals. We identified 110 putative causal variants with posterior probabilities ≥0.1 for 57 SLE loci, among which we prioritised 10 most likely putative causal variants (posterior probability ≥0.8). Linkage disequilibrium score regression detected genetic correlations for SLE with albumin/globulin ratio (rg=-0.242) and non-albumin protein (rg=0.238). CONCLUSION: This study reiterates the power of large-scale genome-wide meta-analysis for novel genetic discovery. These findings shed light on genetic and biological understandings of SLE.


Subject(s)
Asian People/genetics , Genetic Loci/genetics , Genetic Predisposition to Disease/ethnology , Lupus Erythematosus, Systemic/ethnology , Lupus Erythematosus, Systemic/genetics , Adult , Bayes Theorem , Case-Control Studies , China/epidemiology , China/ethnology , Asia, Eastern/ethnology , Female , Genetic Predisposition to Disease/epidemiology , Genetic Variation , Genome-Wide Association Study , Genotype , Humans , Japan/epidemiology , Japan/ethnology , Lupus Erythematosus, Systemic/epidemiology , Male , Middle Aged , Prevalence , Republic of Korea/epidemiology , Republic of Korea/ethnology
14.
Hum Mol Genet ; 27(9): 1664-1674, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29481666

ABSTRACT

Comprehensive metabolite profiling captures many highly heritable traits, including amino acid levels, which are potentially sensitive biomarkers for disease pathogenesis. To better understand the contribution of genetic variation to amino acid levels, we performed single variant and gene-based tests of association between nine serum amino acids (alanine, glutamine, glycine, histidine, isoleucine, leucine, phenylalanine, tyrosine, and valine) and 16.6 million genotyped and imputed variants in 8545 non-diabetic Finnish men from the METabolic Syndrome In Men (METSIM) study with replication in Northern Finland Birth Cohort (NFBC1966). We identified five novel loci associated with amino acid levels (P = < 5×10-8): LOC157273/PPP1R3B with glycine (rs9987289, P = 2.3×10-26); ZFHX3 (chr16:73326579, minor allele frequency (MAF) = 0.42%, P = 3.6×10-9), LIPC (rs10468017, P = 1.5×10-8), and WWOX (rs9937914, P = 3.8×10-8) with alanine; and TRIB1 with tyrosine (rs28601761, P = 8×10-9). Gene-based tests identified two novel genes harboring missense variants of MAF <1% that show aggregate association with amino acid levels: PYCR1 with glycine (Pgene = 1.5×10-6) and BCAT2 with valine (Pgene = 7.4×10-7); neither gene was implicated by single variant association tests. These findings are among the first applications of gene-based tests to identify new loci for amino acid levels. In addition to the seven novel gene associations, we identified five independent signals at established amino acid loci, including two rare variant signals at GLDC (rs138640017, MAF=0.95%, Pconditional = 5.8×10-40) with glycine levels and HAL (rs141635447, MAF = 0.46%, Pconditional = 9.4×10-11) with histidine levels. Examination of all single variant association results in our data revealed a strong inverse relationship between effect size and MAF (Ptrend<0.001). These novel signals provide further insight into the molecular mechanisms of amino acid metabolism and potentially, their perturbations in disease.


Subject(s)
Amino Acids/metabolism , Genome-Wide Association Study/methods , Finland , Gene Frequency/genetics , Genotype , Humans , Male , Middle Aged
16.
Exp Cell Res ; 365(1): 138-144, 2018 04 01.
Article in English | MEDLINE | ID: mdl-29501569

ABSTRACT

OBJECTIVE: This study was aimed to explore the effect of Bach2 on B cells in systemic lupus erythematosus (SLE), as well as the underlying mechanisms. METHODS: Expression of Bach2, phosphorylated-Bach2 (p-Bach2), Akt, p-Akt and BCR-ABL (p210) in B cells isolated from SLE patients and the healthy persons were assessed by Western blot. Immunofluorescence staining was performed to assess the localization of Bach2 in B cells. Enzyme-linked immunosorbent assay (ELISA) was employed to detect IgG produced by B cells. Cell counting kit-8 (CCK-8) and Annexin-V FITC/PI double staining assay were adopted to evaluate cell proliferation and apoptosis in B cells, respectively. RESULTS: Compared to the healthy controls, Bach2, p-Akt and p210 were significantly decreased, while nuclear translocation of Bach2, IgG, CD40 and CD86 obviously up-regulated in B cells from SLE patients. Bach2 significantly inhibited the proliferation, promoted apoptosis of B cells from SLE patients, whereas BCR-ABL dramatically reversed cell changes induced by Bach2. Besides, BCR-ABL also inhibited nuclear translocation of Bach2 in B cells from SLE patients. Further, LY294002 treatment had no effect on decreased expression of Bach2 induced by BCR-ABL, but significantly eliminated BCR-ABL-induced phosphorylation of Bach2 and restored reduced nuclear translocation of Bach2 induced by BCR-ABL in B cells from SLE. CONCLUSIONS: Bach2 may play a suppressive role in B cells from SLE, and BCR-ABL may inhibit the nuclear translocation of Bach2 via serine phosphorylation through the PI3K pathway.


Subject(s)
B-Lymphocytes/metabolism , Basic-Leucine Zipper Transcription Factors/metabolism , Fusion Proteins, bcr-abl/metabolism , Lupus Erythematosus, Systemic/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-bcr/metabolism , Annexin A5/metabolism , Apoptosis/drug effects , B-Lymphocytes/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Chromones/pharmacology , Humans , Immunoglobulin G/metabolism , Morpholines/pharmacology , Phosphorylation/drug effects , Signal Transduction/drug effects , Up-Regulation/drug effects
17.
Hum Genet ; 137(6-7): 431-436, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29855708

ABSTRACT

Genotype imputation is now routinely performed in genomic analysis. Reference panel size, that is, the number of haplotypes in the reference panel, has been well established to be one major driving factor of imputation accuracy. For that reason, huge efforts have been made worldwide to provide large reference panels, with the Haplotype Reference Consortium (HRC) being currently the largest available in the public domain. The imputation performance of HRC, whose major samples are Europeans, has been mainly evaluated in Europeans. We conducted whole-genome genotype imputation on two independent genome-wide genotyping datasets, one with 1000 European samples and the other with 1000 Han Chinese samples. We compared the results obtained using HRC with those using Phase III of the 1000 Genomes Project (1000G) reference panel. For the European dataset, using HRC improved imputation quality, especially for rare variants with minor allele-frequency (MAF) < 0.1%. However, 1000G demonstrates better performance in the Han Chinese dataset, in both imputation quality and number of well-imputed variants. We validated the performance of 1000G reference panel in a second, independent cohort of Han Chinese (N = 2402). Our study showcases the limitations of HRC for Han Chinese populations, strongly suggesting the necessity of building population-specific reference panels.


Subject(s)
Genetics, Population , Genome, Human/genetics , Genotype , Haplotypes/genetics , Asian People/genetics , China/epidemiology , Gene Frequency , Human Genome Project , Humans , Reference Standards
18.
Ann Rheum Dis ; 77(3): 417, 2018 03.
Article in English | MEDLINE | ID: mdl-29233832

ABSTRACT

OBJECTIVES: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of considerable genetic predisposition. Genome-wide association studies have identified tens of common variants for SLE. However, the majority of them reside in non-coding sequences. The contributions of coding variants have not yet been systematically evaluated. METHODS: We performed a large-scale exome-wide study in 5004 SLE cases and 8179 healthy controls in a Han Chinese population using a custom exome array, and then genotyped 32 variants with suggestive evidence in an independent cohort of 13 246 samples. We further explored the regulatory effect of one novel non-coding single nucleotide polymorphism (SNP) in ex vivo experiments. RESULTS: We discovered four novel SLE gene regions (LCT, TPCN2, AHNAK2 and TNFRSF13B) encompassing three novel missense variants (XP_016859577.1:p.Asn1639Ser, XP_016859577.1:p.Val219Phe and XP_005267356.1:p.Thr4664Ala) and two non-coding variants (rs10750836 and rs4792801) with genome-wide significance (pmeta <5.00×10-8). These variants are enriched in several chromatin states of primary B cells. The novel intergenic variant rs10750836 exhibited an expression quantitative trait locus effect on the TPCN2 gene in immune cells. Clones containing this novel SNP exhibited gene promoter activity for TPCN2 (P=1.38×10-3) whose expression level was reduced significantly in patients with SLE (P<2.53×10-2) and was suggested to be further modulated by rs10750836 in CD19+ B cells (P=7.57×10-5) in ex vivo experiments. CONCLUSIONS: This study identified three novel coding variants and four new susceptibility gene regions for SLE. The results provide insights into the biological mechanism of SLE.


Subject(s)
Asian People/genetics , Lupus Erythematosus, Systemic/genetics , Adult , Exome , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Genotype , Humans , Lupus Erythematosus, Systemic/ethnology , Male , Middle Aged , Mutation , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Real-Time Polymerase Chain Reaction
20.
Cell Immunol ; 331: 16-21, 2018 09.
Article in English | MEDLINE | ID: mdl-29748001

ABSTRACT

This study was aimed to investigate whether NFKB1 participates in the pathogenesis of psoriasis by mediating Th1/Th17 cells. In this study, expression of NFKB1 was assessed in skin tissues from psoriasis patients and the healthy controls through Western blot and Immunohistochemistry. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the serum levels of IFN-γ, IL-17 (IL-17A) and IL-17RA. The imiquimod-induced psoriasis mouse model was employed to examine the role of NFKB1 in psoriasis via the assessment of psoriasis area and severity index (PASI), including erythema, thickness and scales. The effects of NFKB1 on Th1/Th17 cells in were examined by flow cytometry. In vitro co-culture of Th1/Th17 cells isolated from different mice with HaCat cells was conducted to elucidate the effect of Th1/Th17 cells-mediated by NFKB1 on HaCat cells by MTT, wound healing and transwell invasion assay, respectively. The results showed that NF-κB p105/p50 expression in skin tissues was significantly increased in psoriasis (n = 21) compared to the healthy controls (n = 16), as well as levels of serum INF-γ and IL-17. Additionally, NF-κB p105/p50 expression in lesional skin tissues was much higher than that in non-lesional skin tissues of the same patients. In the psoriasis mouse model, NFKB1 overexpression significantly elevated the scores of erythema, thickness and scales. Besides, NFKB1 up-regulated the level of NF-κB p105/p50, INF-γ, T-bet, IL-17 and RORγt, as well as Th1/Th17 cells in skin tissues of psoriasis mice. Finally, in vitro assay confirmed that the activation of Th1 and Th17 mediated by NFKB1 in psoriasis promoted the proliferation, migration and invasion of keratinocytes. These findings suggest a critical role for NFKB1 in the regulation of Th1 and Th17 in psoriasis.


Subject(s)
Interleukin-17/immunology , NF-kappa B p50 Subunit/immunology , Psoriasis/immunology , Th1 Cells/immunology , Adult , Animals , Cell Line , Cells, Cultured , Cytokines/blood , Cytokines/immunology , Cytokines/metabolism , Female , Humans , Imiquimod , Interleukin-17/metabolism , Male , Mice, Inbred BALB C , Middle Aged , NF-kappa B p50 Subunit/genetics , NF-kappa B p50 Subunit/metabolism , Psoriasis/chemically induced , Psoriasis/metabolism , Skin/immunology , Skin/metabolism , Skin/pathology , Th1 Cells/metabolism , Young Adult
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