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 HiperbáricaRESUMEN
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.
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/metabolismoRESUMEN
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.
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 , ColesterolRESUMEN
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 adversosRESUMEN
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/métodosRESUMEN
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/metabolismoRESUMEN
Aim: To identify novel genetic variants predisposing to elevation of Alanine aminotransferase (ALT) in rheumatoid arthritis (RA) patients after initiation of methotrexate (MTX) treatment. Patients & methods: We performed genome-wide association studies in 198 RA patients starting MTX. Outcomes were maximum level of ALT and ALT >1.5-times the upper level of normal within the first 6 months of treatment. Results:RAVER2 (rs72675408) was significantly associated with maximum level of ALT (p = 4.36 × 10-8). This variant is in linkage disequilibrium with rs72675451, which is associated with differential expression of JAK1 and RAVER2. Conclusion: We found an association between ALT elevation and genetic variants that may regulate the expression of JAK1 and RAVER2. JAK1 encodes a janus kinase involved in the pathogenesis of RA.
Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Estudio de Asociación del Genoma Completo , Hígado/enzimología , Metotrexato/uso terapéutico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alanina Transaminasa/sangre , Artritis Reumatoide/enzimología , Estudios de Cohortes , Femenino , Regulación de la Expresión Génica , Ribonucleoproteínas Nucleares Heterogéneas/genética , Humanos , Janus Quinasa 1/genética , Hígado/efectos de los fármacos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Adulto JovenRESUMEN
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/fisiologíaRESUMEN
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 NucleótidosRESUMEN
A recent storm (27th-30th October 2018), named Vaia, hit most part of the Northeast of Italy affecting the geomorphic aspect of almost all mountain catchments of the area. The event triggered new instabilities such as windthrows, landslides and debris flows. At present, few studies dealt with the analysis of the impact of a Large Infrequent Disturbance at large catchment scale. This work provides a focus on the Tegnas Torrent Basin (Belluno Province) and aims at detecting how, where, and how much this storm affected the basin. Moreover, it integrates two different approaches considering both the dynamic and static aspects of the sediment, via DEM of Difference (DoD) and Index of Connectivity (IC), respectively. The Tegnas sub-basins responded contrastingly: the Bordina (volcanic origin and covered by pastures and spruce forests) was mainly affected by windthrows (7% of the sub-basin area) and landslides (0.5%), while the Angheraz (outcropping dolomite rocks), was stricken only by debris flows (1.0%). Morphological changes were clear along the entire channel network, with predominant erosion in the steepest upstream parts (over 2 m of the channel elevation), and deposition in the lower main valley floor (over 3 m of the channel elevation). The IC analysis along the instabilities highlighted that the windthrows occurred mainly in areas of high connectivity, which may be important for future management strategies. Moreover, the proposed integrated approach, based on the combination IC-DoD, permitted a detailed identification of sediment routing and a contemporary estimation of erosion and deposition volumes generated by a high magnitude low-frequency event. Based on these results, cascading processes are expected and further analysis are required to fully consider the impact of a Large Infrequent Disturbance.
RESUMEN
BACKGROUND: Phenotypically discordant monozygotic twins (PDMZTs) offer a unique opportunity to study post-zygotic genetic variation and provide insights into the linkage between genotype and phenotype. We report a comprehensive analysis of a pair of PDMZTs. METHODS: Dysmorphic features and delayed neuro-motor development were observed in the proband, whereas her twin sister was phenotypically normal. Four tissues (blood, skin, hair follicles, and buccal mucosa) from both twins were studied using four complementary methods, including whole-exome sequencing, karyotyping, array CGH, and SNP array. RESULTS: In the proband, tetrasomy 18p affecting all studied tissues except for blood was identified. Karyotyping of fibroblasts revealed isochromosome 18p [i(18p)] in all metaphases. The corresponding analysis of the phenotypically normal sister surprisingly revealed low-level mosaicism (5.4%) for i(18p) in fibroblasts. CONCLUSION: We emphasize that when mosaicism is suspected, multiple tissues should be studied and we highlight the usefulness of non-invasive sampling of hair follicles and buccal mucosa as a convenient source of non-mesoderm-derived DNA, which complements the analysis of mesoderm using blood. Moreover, low-level mosaic tetrasomy 18p is well tolerated and such low-level mosaicism, readily detected by karyotyping, can be missed by other methods. Finally, mosaicism for low-level tetrasomy 18p might be more common in the general population than it is currently recognized, due to detection limitations.
Asunto(s)
Discapacidades del Desarrollo/genética , Mosaicismo , Fenotipo , Gemelos Monocigóticos/genética , Aneuploidia , Células Cultivadas , Preescolar , Cromosomas Humanos Par 18/genética , Discapacidades del Desarrollo/diagnóstico , Femenino , Fibroblastos/citología , Humanos , CariotipoRESUMEN
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.
RESUMEN
Chilean territory is recurrently affected by severe wildfires, which drastically reduce the forest cover and promote runoff, soil erosion and slope instabilities. To understand how the geomorphic system responds to wildfires in terms of sediment dynamics, the assessment of sediment connectivity, i.e. the property describing the relationships between compartments of a geomorphic system, is crucial. This study aims to quantify the spatial linkages between fire severity and sediment connectivity to identify common patterns and driving factors. The compound use of field data and open-source satellite imagery helped to apply the Relative differenced Normalized Burn Ratio (RdNBR) and the Index of Connectivity (IC) in the context of two consecutive wildfires, occurred in 2002 and 2015, in the Rio Toro catchment (Chile). The fire severity assessment showed that the 2002 event affected 90% of the catchment, with high severity areas representing around 70%. The 2015 wildfire instead, affected 76% of the catchment with moderate severity around 42%. Accordingly, as result of the sudden reduction in forest cover in severely affected areas, the IC changed after both wildfires with an overall increase of 1.07 and 0.54, respectively. However, only for the second disturbance, it was possible to observe a clear relationship between the RdNBR and the IC variations. The different degree of vegetation cover heterogeneity between the two pre-wildfire scenarios contributed to different fire severity and IC variability between the two disturbances. The use of open-source satellite data and the development of a weighting factor (W), to be used in IC and able to capture the land cover change driven by the wildfires, could make the application of this approach straightforward, promoting its reproducibility in other catchments for land management and risk mitigation purposes.
RESUMEN
Alteration of various metabolites has been linked to type 2 diabetes (T2D) and insulin resistance. However, identifying significant associations between metabolites and tissue-specific phenotypes requires a multi-omics approach. In a cohort of 42 subjects with different levels of glucose tolerance (normal, prediabetes and T2D) matched for age and body mass index, we calculated associations between parameters of whole-body positron emission tomography (PET)/magnetic resonance imaging (MRI) during hyperinsulinemic euglycemic clamp and non-targeted metabolomics profiling for subcutaneous adipose tissue (SAT) and plasma. Plasma metabolomics profiling revealed that hepatic fat content was positively associated with tyrosine, and negatively associated with lysoPC(P-16:0). Visceral adipose tissue (VAT) and SAT insulin sensitivity (Ki), were positively associated with several lysophospholipids, while the opposite applied to branched-chain amino acids. The adipose tissue metabolomics revealed a positive association between non-esterified fatty acids and, VAT and liver Ki. Bile acids and carnitines in adipose tissue were inversely associated with VAT Ki. Furthermore, we detected several metabolites that were significantly higher in T2D than normal/prediabetes. In this study we present novel associations between several metabolites from SAT and plasma with the fat fraction, volume and insulin sensitivity of various tissues throughout the body, demonstrating the benefit of an integrative multi-omics approach.
Asunto(s)
Diabetes Mellitus Tipo 2/diagnóstico , Resistencia a la Insulina , Insulina/metabolismo , Estado Prediabético/diagnóstico , Imagen de Cuerpo Entero/métodos , Anciano , Aminoácidos de Cadena Ramificada/metabolismo , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Fluorodesoxiglucosa F18/administración & dosificación , Fluorodesoxiglucosa F18/metabolismo , Técnica de Clampeo de la Glucosa , Humanos , Grasa Intraabdominal/metabolismo , Metabolismo de los Lípidos , Hígado/metabolismo , Lisofosfolípidos/metabolismo , Imagen por Resonancia Magnética/métodos , Masculino , Metabolómica , Persona de Mediana Edad , Imagen Multimodal/métodos , Tomografía de Emisión de Positrones/métodos , Estado Prediabético/sangre , Estado Prediabético/metabolismo , Grasa Subcutánea/metabolismoRESUMEN
The liver is the largest solid organ and a primary metabolic hub. In recent years, intact cell nuclei were used to perform single-nuclei RNA-seq (snRNA-seq) for tissues difficult to dissociate and for flash-frozen archived tissue samples to discover unknown and rare cell subpopulations. In this study, we performed snRNA-seq of a liver sample to identify subpopulations of cells based on nuclear transcriptomics. In 4282 single nuclei, we detected, on average, 1377 active genes and we identified seven major cell types. We integrated data from 94,286 distal interactions (p < 0.05) for 7682 promoters from a targeted chromosome conformation capture technique (HiCap) and mass spectrometry proteomics for the same liver sample. We observed a reasonable correlation between proteomics and in silico bulk snRNA-seq (r = 0.47) using tissue-independent gene-specific protein abundancy estimation factors. We specifically looked at genes of medical importance. The DPYD gene is involved in the pharmacogenetics of fluoropyrimidine toxicity and some of its variants are analyzed for clinical purposes. We identified a new putative polymorphic regulatory element, which may contribute to variation in toxicity. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and we investigated all known risk genes. We identified a complex regulatory landscape for the SLC2A2 gene with 16 candidate enhancers. Three of them harbor somatic motif breaking and other mutations in HCC in the Pan Cancer Analysis of Whole Genomes dataset and are candidates to contribute to malignancy. Our results highlight the potential of a multi-omics approach in the study of human diseases.
Asunto(s)
Carcinoma Hepatocelular/genética , Núcleo Celular/genética , Biología Computacional/métodos , Neoplasias Hepáticas/genética , Hígado/metabolismo , Transcriptoma , Linfocitos B/citología , Linfocitos B/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Núcleo Celular/metabolismo , Células Endoteliales/citología , Células Endoteliales/metabolismo , Regulación de la Expresión Génica , Células Estrelladas Hepáticas/citología , Células Estrelladas Hepáticas/metabolismo , Hepatocitos/citología , Hepatocitos/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Células Asesinas Naturales/citología , Células Asesinas Naturales/metabolismo , Macrófagos del Hígado/citología , Macrófagos del Hígado/metabolismo , Hígado/citología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Análisis de la Célula Individual/métodos , Linfocitos T/citología , Linfocitos T/metabolismoRESUMEN
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 TratamientoRESUMEN
Long-chain polyunsaturated fatty acids (LC-PUFAs) influence human health in several areas, including cardiovascular disease, diabetes, fatty liver disease, and cancer. ELOVL2 encodes one of the key enzymes in the in vivo synthesis of LC-PUFAs from their precursors. Variants near ELOVL2 have repeatedly been associated with levels of LC-PUFA-derived metabolites in genome-wide association studies (GWAS), but the mechanisms behind these observations remain poorly defined. In this study, we found that rs953413, located in the first intron of ELOVL2, lies within a functional FOXA and HNF4α cooperative binding site. The G allele of rs953413 increases binding of FOXA1/FOXA2 and HNF4α to an evolutionarily conserved enhancer element, conferring allele-specific upregulation of the rs953413-associated gene ELOVL2. The expression of ELOVL2 was significantly downregulated by both FOXA1 and HNF4α knockdown and CRISPR/Cas9-mediated direct mutation to the enhancer element. Our results suggest that rs953413 regulates LC-PUFAs metabolism by altering ELOVL2 expression through FOXA1/FOXA2 and HNF4α cooperation.
RESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.