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1.
Lipids Health Dis ; 23(1): 48, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38365720

RESUMEN

BACKGROUND: Genome-wide association studies (GWAS) have identified genetic variants linked to fat metabolism and related traits, but rarely pinpoint causative variants. This limitation arises from GWAS not considering functional implications of noncoding variants that can affect transcription factor binding and potentially regulate gene expression. The aim of this study is to investigate a candidate noncoding functional variant within a genetic locus flagged by a GWAS SNP associated with non-alcoholic fatty liver disease (NAFLD), a condition characterized by liver fat accumulation in non-alcohol consumers. METHODS: CRISPR-Cas9 gene editing in HepG2 cells was used to modify the regulatory element containing the candidate functional variant linked to NAFLD. Global gene expression in mutant cells was assessed through RT-qPCR and targeted transcriptomics. A phenotypic assay measured lipid droplet accumulation in the CRISPR-Cas9 mutants. RESULTS: The candidate functional variant, rs2294510, closely linked to the NAFLD-associated GWAS SNP rs11206226, resided in a regulatory element within the DIO1 gene's promoter region. Altering this element resulted in changes in transcription factor binding sites and differential expression of candidate target genes like DIO1, TMEM59, DHCR24, and LDLRAD1, potentially influencing the NAFLD phenotype. Mutant HepG2 cells exhibited increased lipid accumulation, a hallmark of NAFLD, along with reduced LDL-C, HDL-C and elevated triglycerides. CONCLUSIONS: This comprehensive approach, that combines genome editing, transcriptomics, and phenotypic assays identified the DIO1 promoter region as a potential enhancer. Its activity could regulate multiple genes involved in the NAFLD phenotype or contribute to defining a polygenic risk score for enhanced risk assessment in NAFLD patients.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Humanos , LDL-Colesterol/genética , Estudio de Asociación del Genoma Completo , Células Hep G2 , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Regiones Promotoras Genéticas/genética , Factores de Transcripción/genética , Triglicéridos/metabolismo , Yoduro Peroxidasa/genética , HDL-Colesterol/genética , HDL-Colesterol/metabolismo
2.
Hepatol Res ; 51(2): 233-238, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33119937

RESUMEN

AIM: The aim of this study was to explore the benefits of data integration from different platforms for single nucleus transcriptomics profiling to characterize cell populations in human liver. METHODS: We generated single-nucleus RNA sequencing data from Chromium 10X Genomics and Drop-seq for a human liver sample. We utilized state of the art bioinformatics tools to undertake a rigorous quality control and to integrate the data into a common space summarizing the gene expression variation from the respective platforms, while accounting for known and unknown confounding factors. RESULTS: Analysis of single nuclei transcriptomes from both 10X and Drop-seq allowed identification of the major liver cell types, while the integrated set obtained enough statistical power to separate a small population of inactive hepatic stellate cells that was not characterized in either of the platforms. CONCLUSIONS: Integration of droplet-based single nucleus transcriptomics data enabled identification of a small cluster of inactive hepatic stellate cells that highlights the potential of our approach. We suggest single-nucleus RNA sequencing integrative approaches could be utilized to design larger and cost-effective studies.

3.
Pharmacogenomics J ; 20(6): 770-783, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32080354

RESUMEN

Angioedema in the mouth or upper airways is a feared adverse reaction to angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) treatment, which is used for hypertension, heart failure and diabetes complications. This candidate gene and genome-wide association study aimed to identify genetic variants predisposing to angioedema induced by these drugs. The discovery cohort consisted of 173 cases and 4890 controls recruited in Sweden. In the candidate gene analysis, ETV6, BDKRB2, MME, and PRKCQ were nominally associated with angioedema (p < 0.05), but did not pass Bonferroni correction for multiple testing (p < 2.89 × 10-5). In the genome-wide analysis, intronic variants in the calcium-activated potassium channel subunit alpha-1 (KCNMA1) gene on chromosome 10 were significantly associated with angioedema (p < 5 × 10-8). Whilst the top KCNMA1 hit was not significant in the replication cohort (413 cases and 599 ACEi-exposed controls from the US and Northern Europe), a meta-analysis of the replication and discovery cohorts (in total 586 cases and 1944 ACEi-exposed controls) revealed that each variant allele increased the odds of experiencing angioedema 1.62 times (95% confidence interval 1.05-2.50, p = 0.030). Associated KCNMA1 variants are not known to be functional, but are in linkage disequilibrium with variants in transcription factor binding sites active in relevant tissues. In summary, our data suggest that common variation in KCNMA1 is associated with risk of angioedema induced by ACEi or ARB treatment. Future whole exome or genome sequencing studies will show whether rare variants in KCNMA1 or other genes contribute to the risk of ACEi- and ARB-induced angioedema.


Asunto(s)
Angioedema/inducido químicamente , Angioedema/genética , Antagonistas de Receptores de Angiotensina/efectos adversos , Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Estudio de Asociación del Genoma Completo/métodos , Adulto , Anciano , Anciano de 80 o más Años , Angioedema/epidemiología , Antagonistas de Receptores de Angiotensina/administración & dosificación , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Suecia/epidemiología , Resultado del Tratamiento
4.
Hum Genomics ; 13(1): 20, 2019 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-31036066

RESUMEN

BACKGROUND: Genome-wide association studies (GWAS) of diseases and traits have found associations to gene regions but not the functional SNP or the gene mediating the effect. Difference in gene regulatory signals can be detected using chromatin immunoprecipitation and next-gen sequencing (ChIP-seq) of transcription factors or histone modifications by aligning reads to known polymorphisms in individual genomes. The aim was to identify such regulatory elements in the human liver to understand the genetics behind type 2 diabetes and metabolic diseases. METHODS: The genome of liver tissue was sequenced using 10X Genomics technology to call polymorphic positions. Using ChIP-seq for two histone modifications, H3K4me3 and H3K27ac, and the transcription factor CTCF, and our established bioinformatics pipeline, we detected sites with significant difference in signal between the alleles. RESULTS: We detected 2329 allele-specific SNPs (AS-SNPs) including 25 associated to GWAS SNPs linked to liver biology, e.g., 4 AS-SNPs at two type 2 diabetes loci. Two hundred ninety-two AS-SNPs were associated to liver gene expression in GTEx, and 134 AS-SNPs were located on 166 candidate functional motifs and most of them in EGR1-binding sites. CONCLUSIONS: This study provides a valuable collection of candidate liver regulatory elements for further experimental validation.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad , Hígado/metabolismo , Enfermedades Metabólicas/genética , Alelos , Factor de Unión a CCCTC/genética , Diabetes Mellitus Tipo 2/patología , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Regulación de la Expresión Génica/genética , Genoma Humano/genética , Estudio de Asociación del Genoma Completo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Hígado/patología , Enfermedades Metabólicas/patología , Polimorfismo de Nucleótido Simple/genética , Secuencias Reguladoras de Ácidos Nucleicos/genética
5.
Nucleic Acids Res ; 45(5): 2408-2422, 2017 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-27932482

RESUMEN

The FADS1 and FADS2 genes in the FADS cluster encode the rate-limiting enzymes in the synthesis of long-chain polyunsaturated fatty acids (LC-PUFAs). Genetic variation in this region has been associated with a large number of diseases and traits many of them correlated to differences in metabolism of PUFAs. However, the causative variants leading to these associations have not been identified. Here we find that the multiallelic rs174557 located in an AluYe5 element in intron 1 of FADS1 is functional and lies within a PATZ1 binding site. The derived allele of rs174557, which is the common variant in most populations, diminishes binding of PATZ1, a transcription factor conferring allele-specific downregulation of FADS1. The PATZ1 binding site overlaps with a SP1 site. The competitive binding between the suppressive PATZ1 and the activating complex of SP1 and SREBP1c determines the enhancer activity of this region, which regulates expression of FADS1.


Asunto(s)
Ácido Graso Desaturasas/genética , Regulación de la Expresión Génica , Factores de Transcripción de Tipo Kruppel/metabolismo , Proteínas Represoras/metabolismo , Factor de Transcripción Sp1/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Alelos , Elementos Alu , Animales , Unión Competitiva , Línea Celular , delta-5 Desaturasa de Ácido Graso , Regulación hacia Abajo , Elementos de Facilitación Genéticos , Evolución Molecular , Haplotipos , Humanos , Pan troglodytes , Polimorfismo de Nucleótido Simple
6.
Nucleic Acids Res ; 44(19): 9110-9120, 2016 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-27625394

RESUMEN

Gene transcription is regulated mainly by transcription factors (TFs). ENCODE and Roadmap Epigenomics provide global binding profiles of TFs, which can be used to identify regulatory regions. To this end we implemented a method to systematically construct cell-type and species-specific maps of regulatory regions and TF-TF interactions. We illustrated the approach by developing maps for five human cell-lines and two other species. We detected ∼144k putative regulatory regions among the human cell-lines, with the majority of them being ∼300 bp. We found ∼20k putative regulatory elements in the ENCODE heterochromatic domains suggesting a large regulatory potential in the regions presumed transcriptionally silent. Among the most significant TF interactions identified in the heterochromatic regions were CTCF and the cohesin complex, which is in agreement with previous reports. Finally, we investigated the enrichment of the obtained putative regulatory regions in the 3D chromatin domains. More than 90% of the regions were discovered in the 3D contacting domains. We found a significant enrichment of GWAS SNPs in the putative regulatory regions. These significant enrichments provide evidence that the regulatory regions play a crucial role in the genomic structural stability. Additionally, we generated maps of putative regulatory regions for prostate and colorectal cancer human cell-lines.


Asunto(s)
Genómica , Secuencias Reguladoras de Ácidos Nucleicos , Sitios de Unión , Línea Celular , Cromatina/genética , Cromatina/metabolismo , Inmunoprecipitación de Cromatina , Mapeo Cromosómico , Biología Computacional/métodos , Genoma Humano , Estudio de Asociación del Genoma Completo , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Anotación de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Unión Proteica , Mapeo de Interacción de Proteínas , Mapas de Interacción de Proteínas , Factores de Transcripción/metabolismo
7.
Hepatol Res ; 47(8): 826-830, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27577861

RESUMEN

AIM: Infection by hepatitis C virus (HCV) can result in the development of liver fibrosis and may eventually progress into cirrhosis and hepatocellular carcinoma. However, the molecular mechanisms for this process are not fully known. Several genome-wide association studies have been carried out to pinpoint causative variants in HCV-infected patient cohorts, but these variants are usually not the functional ones. The aim of this study was to identify the regulatory single nucleotide polymorphism associated with the risk of HCV-induced liver fibrosis and elucidate its molecular mechanism. METHODS: We utilized a bioinformatics approach to identify a non-coding regulatory variant, located in an intron of the MERTK gene, based on differential transcription factor binding between the alleles. We validated the results using expression reporter assays and electrophoresis mobility shift assays. RESULTS: Chromatin immunoprecipitation sequencing indicated that transcription factor(s) bind stronger to the A allele of rs6726639. Electrophoresis mobility shift assays supported these findings and suggested that the transcription factor is interferon regulatory factor 1 (IRF1). Luciferase report assays showed lower enhancer activity from the A allele and that IRF1 may act as a repressor. CONCLUSIONS: Treatment of hepatitis C with interferon-α results in increased IRF1 levels and our data suggest that this leads to an allele-specific downregulation of MERTK mediated by an allelic effect on the regulatory element containing the functional rs6726639. This variant also shows the hallmarks for being the driver of the genome-wide association studies for reduced risk of liver fibrosis and non-alcoholic fatty liver disease at MERTK.

8.
Genomics ; 107(6): 248-54, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27126307

RESUMEN

Genome-wide association studies (GWAS) point to regions with associated genetic variants but rarely to a specific gene and therefore detailed knowledge regarding the genes contributing to complex traits and diseases remains elusive. The functional role of GWAS-SNPs is also affected by linkage disequilibrium with many variants on the same haplotype and sometimes in the same regulatory element almost equally likely to mediate the effect. Using ChIP-seq data on many transcription factors, we pinpointed genetic variants in HepG2 and HeLa-S3 cell lines which show a genome-wide significant difference in binding between alleles. We identified a collection of 3713 candidate functional regulatory variants many of which are likely drivers of GWAS signals or genetic difference in expression. A recent study investigated many variants before finding the functional ones at the GALNT2 locus, which we found in our genome-wide screen in HepG2. This illustrates the efficiency of our approach.


Asunto(s)
Genes Reguladores/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Factores de Transcripción/genética , Alelos , Cuello del Útero/metabolismo , Femenino , Expresión Génica/genética , Genoma Humano , Haplotipos , Células HeLa , Células Hep G2 , Humanos , Desequilibrio de Ligamiento , Hígado/metabolismo , N-Acetilgalactosaminiltransferasas/biosíntesis , N-Acetilgalactosaminiltransferasas/genética , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo/genética , Factores de Transcripción/biosíntesis , Polipéptido N-Acetilgalactosaminiltransferasa
9.
Hum Mutat ; 37(9): 904-13, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27174533

RESUMEN

Somatic mutations drive cancer and there are established ways to study those in coding sequences. It has been shown that some regulatory mutations are over-represented in cancer. We develop a new strategy to find putative regulatory mutations based on experimentally established motifs for transcription factors (TFs). In total, we find 1,552 candidate regulatory mutations predicted to significantly reduce binding affinity of many TFs in hepatocellular carcinoma and affecting binding of CTCF also in esophagus, gastric, and pancreatic cancers. Near mutated motifs, there is a significant enrichment of (1) genes mutated in cancer, (2) tumor-suppressor genes, (3) genes in KEGG cancer pathways, and (4) sets of genes previously associated to cancer. Experimental and functional validations support the findings. The strategy can be applied to identify regulatory mutations in any cell type with established TF motifs and will aid identifications of genes contributing to cancer.


Asunto(s)
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Mutación , Factores de Transcripción/genética , Sitios de Unión , Bases de Datos Genéticas , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Predisposición Genética a la Enfermedad , Células Hep G2 , Humanos , Unión Proteica , Análisis de Secuencia de ADN , Factores de Transcripción/metabolismo
10.
Hum Genet ; 135(5): 485-497, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26993500

RESUMEN

Genome-wide association studies (GWAS) have identified a large number of disease-associated SNPs, but in few cases the functional variant and the gene it controls have been identified. To systematically identify candidate regulatory variants, we sequenced ENCODE cell lines and used public ChIP-seq data to look for transcription factors binding preferentially to one allele. We found 9962 candidate regulatory SNPs, of which 16 % were rare and showed evidence of larger functional effect than common ones. Functionally rare variants may explain divergent GWAS results between populations and are candidates for a partial explanation of the missing heritability. The majority of allele-specific variants (96 %) were specific to a cell type. Furthermore, by examining GWAS loci we found >400 allele-specific candidate SNPs, 141 of which were highly relevant in our cell types. Functionally validated SNPs support identification of an SNP in SYNGR1 which may expose to the risk of rheumatoid arthritis and primary biliary cirrhosis, as well as an SNP in the last intron of COG6 exposing to the risk of psoriasis. We propose that by repeating the ChIP-seq experiments of 20 selected transcription factors in three to ten people, the most common polymorphisms can be interrogated for allele-specific binding. Our strategy may help to remove the current bottleneck in functional annotation of the genome.


Asunto(s)
Perfilación de la Expresión Génica , Predisposición Genética a la Enfermedad , Neuroblastoma/genética , Neuroblastoma/metabolismo , Polimorfismo de Nucleótido Simple/genética , Factores de Transcripción/metabolismo , Alelos , Biomarcadores , Genotipo , Humanos , Células K562 , Unión Proteica , Células Tumorales Cultivadas
11.
Lipids Health Dis ; 15: 18, 2016 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-26817450

RESUMEN

BACKGROUND: Plasma levels of high-density lipoprotein cholesterol (HDL-C) have been associated to cardiovascular disease. The high heritability of HDL-C plasma levels has been an incentive for several genome wide association studies (GWASs) which identified, among others, variants in the first intron of the GALNT2 gene strongly associated to HDL-C levels. However, the lead GWAS SNP associated to HDL-C levels in this genomic region, rs4846914, is located outside of transcription factor (TF) binding sites defined by chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq) experiments in the ENCODE project and is therefore unlikely to be functional. In this study we apply a bioinformatics approach which rely on the premise that ChIP-seq reads can identify allele specific binding of a TF at cell specific regulatory elements harboring allele specific SNPs (AS-SNPs). EMSA and luciferase assays were used to validate the allele specific binding and to test the enhancer activity of the regulatory element harboring the AS-SNP rs4846913 as well as the neighboring rs2144300 which are in high LD with rs4846914. FINDINGS: Using luciferase assays we found that rs4846913 and the neighboring rs2144300 displayed allele specific enhancer activity. We propose that an inhibitor binds preferentially to the rs4846913-C allele with an inhibitory boost from the synergistic binding of other TFs at the neighboring SNP rs2144300. These events influence the transcription level of GALNT2. CONCLUSIONS: The results suggest that rs4846913 and rs2144300 drive the association to HDL-C plasma levels through an inhibitory regulation of GALNT2 rather than the reported lead GWAS SNP rs4846914.


Asunto(s)
Alelos , HDL-Colesterol/sangre , Estudio de Asociación del Genoma Completo , N-Acetilgalactosaminiltransferasas/genética , Factores de Transcripción/metabolismo , Células Hep G2 , Humanos , Desequilibrio de Ligamiento/genética , Polimorfismo de Nucleótido Simple/genética , Unión Proteica , Polipéptido N-Acetilgalactosaminiltransferasa
12.
NPJ Vaccines ; 9(1): 42, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38388530

RESUMEN

Type I interferons act as gatekeepers against viral infection, and autoantibodies that neutralize these signaling molecules have been associated with COVID-19 severity and adverse reactions to the live-attenuated yellow fever vaccine. On this background, we sought to examine whether autoantibodies against type I interferons were associated with adverse events following COVID-19 vaccination. Our nationwide analysis suggests that type I interferon autoantibodies were not associated with adverse events after mRNA or viral-vector COVID-19 vaccines.

13.
Biomolecules ; 14(4)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38672497

RESUMEN

BACKGROUND: In military flight operations, during flights, fighter pilots constantly work under hyperoxic breathing conditions with supplemental oxygen in varying hypobaric environments. These conditions are suspected to cause oxidative stress to neuronal organ tissues. For civilian flight operations, the Federal Aviation Administration (FAA) also recommends supplemental oxygen for flying under hypobaric conditions equivalent to higher than 3048 m altitude, and has made it mandatory for conditions equivalent to more than 3657 m altitude. AIM: We hypothesized that hypobaric-hyperoxic civilian commercial and private flight conditions with supplemental oxygen in a flight simulation in a hypobaric chamber at 2500 m and 4500 m equivalent altitude would cause significant oxidative stress in healthy individuals. METHODS: Twelve healthy, COVID-19-vaccinated (third portion of vaccination 15 months before study onset) subjects (six male, six female, mean age 35.7 years) from a larger cohort were selected to perform a 3 h flight simulation in a hypobaric chamber with increasing supplemental oxygen levels (35%, 50%, 60%, and 100% fraction of inspired oxygen, FiO2, via venturi valve-equipped face mask), switching back and forth between simulated altitudes of 2500 m and 4500 m. Arterial blood pressure and oxygen saturation were constantly measured via radial catheter and blood samples for blood gases taken from the catheter at each altitude and oxygen level. Additional blood samples from the arterial catheter at baseline and 60% oxygen at both altitudes were centrifuged inside the chamber and the serum was frozen instantly at -21 °C for later analysis of the oxidative stress markers malondialdehyde low-density lipoprotein (M-LDL) and glutathione-peroxidase 1 (GPX1) via the ELISA test. RESULTS: Eleven subjects finished the study without adverse events. Whereas the partial pressure of oxygen (PO2) levels increased in the mean with increasing oxygen levels from baseline 96.2 mm mercury (mmHg) to 160.9 mmHg at 2500 m altitude and 60% FiO2 and 113.2 mmHg at 4500 m altitude and 60% FiO2, there was no significant increase in both oxidative markers from baseline to 60% FiO2 at these simulated altitudes. Some individuals had a slight increase, whereas some showed no increase at all or even a slight decrease. A moderate correlation (Pearson correlation coefficient 0.55) existed between subject age and glutathione peroxidase levels at 60% FiO2 at 4500 m altitude. CONCLUSION: Supplemental oxygen of 60% FiO2 in a flight simulation, compared to flying in cabin pressure levels equivalent to 2500 m-4500 m altitude, does not lead to a significant increase or decrease in the oxidative stress markers M-LDL and GPX1 in the serum of arterial blood.


Asunto(s)
Altitud , Estrés Oxidativo , Oxígeno , Humanos , Masculino , Femenino , Adulto , Oxígeno/metabolismo , COVID-19 , Hiperoxia/sangre , Aeronaves , Oxigenoterapia Hiperbárica
14.
Sci Total Environ ; 903: 166103, 2023 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-37558069

RESUMEN

River widening, defined as a lateral expansion of the channel, is a critical process that maintains fluvial ecosystems and is part of the regular functioning of rivers. However, in areas with high population density, channel widening can cause damage during floods. Therefore, for effective flood risk management it is essential to identify river reaches where abrupt channel widening may occur. Despite numerous efforts to predict channel widening, most studies have been limited to single rivers and single flood events, which may not be representative of other conditions. Moreover, a multi-catchment scale approach that covers various settings and flood magnitudes has been lacking. In this study, we fill this gap by compiling a large database comprising 1564 river reaches in several mountain regions in Europe affected by floods of varying magnitudes in the last six decades. By applying a meta-analysis, we aimed to identify the types of floods responsible for more extensive widening, the river reach types where intense widening is more likely to occur, and the hydraulic and morphological variables that explain widening and can aid in predicting widening. Our analysis revealed seven groups of reaches with significantly different responses to floods regarding width ratios (i.e., the ratio between channel width after and before a flood). Among these groups, the river reaches located in the Mediterranean region and affected by extreme floods triggered by short and intense precipitation events showed significantly larger widening than other river reaches in other regions. Additionally, the meta-analysis confirmed valley confinement as a critical morphological variable that controls channel widening but showed that it is not the only controlling factor. We proposed new statistical models to identify river reaches prone to widening, estimate potential channel width after a flood, and compute upper bound width ratios. These findings can inform flood hazard evaluations and the design of mitigation measures.

15.
Sci Rep ; 12(1): 5772, 2022 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-35388090

RESUMEN

DNA methylation is a central epigenetic mark that has diverse roles in gene regulation, development, and maintenance of genome integrity. 5 methyl cytosine (5mC) can be interrogated at base resolution in single cells by using bisulfite sequencing (scWGBS). Several different scWGBS strategies have been described in recent years to study DNA methylation in single cells. However, there remain limitations with respect to cost-efficiency and yield. Herein, we present a new development in the field of scWGBS library preparation; single cell Splinted Ligation Adapter Tagging (scSPLAT). scSPLAT employs a pooling strategy to facilitate sample preparation at a higher scale and throughput than previously possible. We demonstrate the accuracy and robustness of the method by generating data from 225 single K562 cells and from 309 single liver nuclei and compare scSPLAT against other scWGBS methods.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Sulfitos , Metilación de ADN , Biblioteca de Genes , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Oligonucleótidos , Análisis de Secuencia de ADN/métodos
16.
Pharmacogenomics ; 23(15): 813-820, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36070248

RESUMEN

Aim: A follow-up genome-wide association study (GWAS) in an extended cohort of rheumatoid arthritis (RA) patients starting low-dose methotrexate (MTX) treatment was performed to identify further genetic variants associated with alanine aminotransferase (ALT) elevation. Patients & methods: A GWAS was performed on 346 RA patients. Two outcomes within the first 6 months of MTX treatment were assessed: ALT >1.5-times the upper level of normal (ULN) and maximum level of ALT. Results: SPATA9 (rs72783407) was significantly associated with maximum level of ALT (p = 2.58 × 10-8) and PLCG2 (rs60427389) was tentatively associated with ALT >1.5 × ULN. Conclusion: Associations with SNPs in genes related to male fertility (SPATA9) and inflammatory processes (PLCG2) were identified.


Asunto(s)
Antirreumáticos , Artritis Reumatoide , Humanos , Masculino , Metotrexato/efectos adversos , Estudio de Asociación del Genoma Completo , Alanina Transaminasa , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/genética , Hígado , Antirreumáticos/efectos adversos
17.
Cell Rep Med ; 3(10): 100763, 2022 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-36198307

RESUMEN

Environmental and genetic factors cause defects in pancreatic islets driving type 2 diabetes (T2D) together with the progression of multi-tissue insulin resistance. Mass spectrometry proteomics on samples from five key metabolic tissues of a cross-sectional cohort of 43 multi-organ donors provides deep coverage of their proteomes. Enrichment analysis of Gene Ontology terms provides a tissue-specific map of altered biological processes across healthy, prediabetes (PD), and T2D subjects. We find widespread alterations in several relevant biological pathways, including increase in hemostasis in pancreatic islets of PD, increase in the complement cascade in liver and pancreatic islets of PD, and elevation in cholesterol biosynthesis in liver of T2D. Our findings point to inflammatory, immune, and vascular alterations in pancreatic islets in PD that are hypotheses to be tested for potential contributions to hormonal perturbations such as impaired insulin and increased glucagon production. This multi-tissue proteomic map suggests tissue-specific metabolic dysregulations in T2D.


Asunto(s)
Diabetes Mellitus Tipo 2 , Estado Prediabético , Humanos , Diabetes Mellitus Tipo 2/diagnóstico , Estado Prediabético/diagnóstico , Proteómica , Glucagón/metabolismo , Proteoma/metabolismo , Estudios Transversales , Insulina/genética , Redes y Vías Metabólicas/genética , Colesterol
18.
Biochim Biophys Acta Gene Regul Mech ; 1864(8): 194724, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34171462

RESUMEN

The stearoyl-CoA desaturase 1 (SCD1) gene at 10q24.31 encodes the rate limiting enzyme SCD1 that catalyzes the biosynthesis of monounsaturated fatty acids (MUFAs) from saturated fatty acids (SFAs). Dysregulated SCD1 activity has been observed in many human diseases including non-alcoholic fatty liver disease (NAFLD), obesity, hypertension, hyperlipidemia, metabolic syndrome and several types of cancer. HNF4A is a central regulator of glucose and lipid metabolism and previous studies suggested that it is deeply involved in regulating the SCD1 activity in the liver. However, the underlying mechanisms on whether and how SCD1 is regulated by HNF4A have not been explored in detail. In this study, we found that HNF4A regulates SCD1 expression by directly binding to the key regulatory regions in the SCD1 locus. Knocking down of HNF4A significantly downregulated the expression of SCD1. Variants rs55710213 and rs56334587 in intron 5 of SCD1 directly reside in a canonical HNF4A binding site. The GG haplotype of rs55710213 and rs56334587 is associated with decreased SCD1 activity by disrupting the binding of HNF4A, which further decreased the enhancer activity and SCD1 expression. In conclusion, our study demonstrated that SCD1 is directly regulated by HNF4A, which may be helpful in the understanding of the altered metabolic pathways in many diseases associated with dysregulated SCD1 or HNF4A or both.


Asunto(s)
Regulación Enzimológica de la Expresión Génica , Factor Nuclear 4 del Hepatocito/metabolismo , Polimorfismo de Nucleótido Simple , Estearoil-CoA Desaturasa/genética , Sitios de Unión , Elementos de Facilitación Genéticos , Haplotipos , Células Hep G2 , Humanos , Desequilibrio de Ligamiento , Motivos de Nucleótidos
19.
Life Sci Alliance ; 4(7)2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34099540

RESUMEN

Recent studies suggested that dysregulated YY1 plays a pivotal role in many liver diseases. To obtain a detailed view of genes and pathways regulated by YY1 in the liver, we carried out RNA sequencing in HepG2 cells after YY1 knockdown. A rigid set of 2,081 differentially expressed genes was identified by comparing the YY1-knockdown samples (n = 8) with the control samples (n = 14). YY1 knockdown significantly decreased the expression of several key transcription factors and their coactivators in lipid metabolism. This is illustrated by YY1 regulating PPARA expression through binding to its promoter and enhancer regions. Our study further suggest that down-regulation of the key transcription factors together with YY1 knockdown significantly decreased the cooperation between YY1 and these transcription factors at various regulatory regions, which are important in regulating the expression of genes in hepatic lipid metabolism. This was supported by the finding that the expression of SCD and ELOVL6, encoding key enzymes in lipogenesis, were regulated by the cooperation between YY1 and PPARA/RXRA complex over their promoters.


Asunto(s)
Metabolismo de los Lípidos/genética , Hígado/metabolismo , Factor de Transcripción YY1/metabolismo , Secuencia de Bases , Elongasas de Ácidos Grasos , Células Hep G2 , Humanos , Metabolismo de los Lípidos/fisiología , PPAR alfa/genética , Regiones Promotoras Genéticas/genética , Receptor alfa X Retinoide , Estearoil-CoA Desaturasa , Factores de Transcripción/genética , Factor de Transcripción YY1/genética , Factor de Transcripción YY1/fisiología
20.
OMICS ; 25(10): 652-659, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34520261

RESUMEN

Type 2 diabetes (T2D) is characterized by pathophysiological alterations in lipid metabolism. One strategy to understand the molecular mechanisms behind these abnormalities is to identify cis-regulatory elements (CREs) located in chromatin-accessible regions of the genome that regulate key genes. In this study we integrated assay for transposase-accessible chromatin followed by sequencing (ATAC-seq) data, widely used to decode chromatin accessibility, with multi-omics data and publicly available CRE databases to identify candidate CREs associated with T2D for further experimental validations. We performed high-sensitive ATAC-seq in nine human liver samples from normal and T2D donors, and identified a set of differentially accessible regions (DARs). We identified seven DARs including a candidate enhancer for the ACOT1 gene that regulates the balance of acyl-CoA and free fatty acids (FFAs) in the cytoplasm. The relevance of ACOT1 regulation in T2D was supported by the analysis of transcriptomics and proteomics data in liver tissue. Long-chain acyl-CoA thioesterases (ACOTs) are a group of enzymes that hydrolyze acyl-CoA esters to FFAs and coenzyme A. ACOTs have been associated with regulation of triglyceride levels, fatty acid oxidation, mitochondrial function, and insulin signaling, linking their regulation to the pathogenesis of T2D. Our strategy integrating chromatin accessibility with DNA binding and other types of omics provides novel insights on the role of genetic regulation in T2D and is extendable to other complex multifactorial diseases.


Asunto(s)
Diabetes Mellitus Tipo 2 , Metabolismo de los Lípidos , Cromatina/metabolismo , Secuenciación de Inmunoprecipitación de Cromatina , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Metabolismo de los Lípidos/genética , Hígado/metabolismo , Tioléster Hidrolasas/genética , Tioléster Hidrolasas/metabolismo
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