RESUMEN
Assigning function to single nucleotide polymorphisms (SNPs) to understand the mechanisms that link genetic and phenotypic variation and disease is an area of intensive research that is necessary to contribute to the continuing development of precision medicine. However, despite the apparent simplicity that is captured in the name SNP - 'single nucleotide' changes are not easy to functionally characterize. This complexity arises from multiple features of the genome including the fact that function is development and environment specific. As such, we are often fooled by our terminology and underlying assumptions that there is a single function for a SNP. Here we discuss some of what is known about SNPs, their functions and how we can go about characterizing them.
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Variación Genética/genética , Aprendizaje Automático/normas , Polimorfismo de Nucleótido Simple/genética , Medicina de Precisión/métodos , HumanosRESUMEN
Preeclampsia (PE) is a relatively common but severe pregnancy disorder (with very limited effective treatments) characterized by hypertension (HTN) and usually proteinuria (PRO) or other organ damage. Genome-wide association studies (GWAS) of PE, HTN, and PRO have mostly identified risk loci single nucleotide polymorphisms (SNPs) located in noncoding genomic regions, likely impacting the regulation of distal gene expression. The latest GWAS associated (P < 1 × 10-6) SNPs to PE (n = 25), HTN (n = 1926), and PRO (n = 170). Our algorithmic analysis (CoDeS3D) used chromatin connection data (Hi-C) derived from 70 cell lines followed by analysis of two expression quantitative trail loci (eQTL) cohorts: GTEx (838 donors, 54 tissues, totaling 15 253 samples) and DICE (91 donors, 13 blood tissue types). We identified spatially constrained eQTLs which implicate gene targets in PE (n = 16), HTN (n = 3561), and PRO (n = 335). By overlapping these target genes and their molecular pathways (protein-protein interaction networks), we identified shared functional impacts between PE and HTN, which are significantly enriched for regulatory interactions which target genes intolerant to loss-of-function mutations. While the disease-associated SNP loci mostly do not overlap, the regulatory signals (target genes and pathways) overlap, informing on PE risk mechanisms. This demonstrates a model in which genetic predisposition to HTN and PRO lays a molecular groundwork toward risk for PE pathogenesis. This overlap at the gene regulatory network level identifies possible shared therapeutic targets for future study.
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Hipertensión , Preeclampsia , Femenino , Humanos , Estudio de Asociación del Genoma Completo , Preeclampsia/genética , Sitios de Carácter Cuantitativo , Regulación de la Expresión Génica , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido SimpleRESUMEN
The latest meta-analysis of genome-wide association studies identified 90 independent variants across 78 genomic regions associated with Parkinson's disease, yet the mechanisms by which these variants influence the development of the disease remains largely elusive. To establish the functional gene regulatory networks associated with Parkinson's disease risk variants, we utilized an approach combining spatial (chromosomal conformation capture) and functional (expression quantitative trait loci) data. We identified 518 genes subject to regulation by 76 Parkinson's variants across 49 tissues, whicih encompass 36 peripheral and 13 CNS tissues. Notably, one-third of these genes were regulated via trans-acting mechanisms (distal; risk locus-gene separated by >1â Mb, or on different chromosomes). Of particular interest is the identification of a novel trans-expression quantitative trait loci-gene connection between rs10847864 and SYNJ1 in the adult brain cortex, highlighting a convergence between familial studies and Parkinson's disease genome-wide association studies loci for SYNJ1 (PARK20) for the first time. Furthermore, we identified 16 neurodevelopment-specific expression quantitative trait loci-gene regulatory connections within the foetal cortex, consistent with hypotheses suggesting a neurodevelopmental involvement in the pathogenesis of Parkinson's disease. Through utilizing Louvain clustering we extracted nine significant and highly intraconnected clusters within the entire gene regulatory network. The nine clusters are enriched for specific biological processes and pathways, some of which have not previously been associated with Parkinson's disease. Together, our results not only contribute to an overall understanding of the mechanisms and impact of specific combinations of Parkinson's disease variants, but also highlight the potential impact gene regulatory networks may have when elucidating aetiological subtypes of Parkinson's disease.
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Estudio de Asociación del Genoma Completo , Enfermedad de Parkinson , Adulto , Redes Reguladoras de Genes/genética , Predisposición Genética a la Enfermedad/genética , Genómica , Humanos , Enfermedad de Parkinson/genéticaRESUMEN
Ribosomal DNA genes (rDNA) encode the major ribosomal RNAs and in eukaryotes typically form tandem repeat arrays. Species have characteristic rDNA copy numbers, but there is substantial intra-species variation in copy number that results from frequent rDNA recombination. Copy number differences can have phenotypic consequences, however difficulties in quantifying copy number mean we lack a comprehensive understanding of how copy number evolves and the consequences. Here we present a genomic sequence read approach to estimate rDNA copy number based on modal coverage to help overcome limitations with existing mean coverage-based approaches. We validated our method using Saccharomyces cerevisiae strains with known rDNA copy numbers. Application of our pipeline to a global sample of S. cerevisiae isolates showed that different populations have different rDNA copy numbers. Our results demonstrate the utility of the modal coverage method, and highlight the high level of rDNA copy number variation within and between populations.
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Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Variaciones en el Número de Copia de ADN , ADN Ribosómico/genética , ARN Ribosómico/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genéticaRESUMEN
BACKGROUND/OBJECTIVES: Modelling genetic pre-disposition may identify children at risk of obesity. However, most polygenic scores (PGSs) have been derived in adults, and lack validation during childhood. This study compared the utility of existing large-scale adult-derived PGSs to predict common anthropometric traits (body mass index (BMI), waist circumference, and body fat) in children and adults, and examined whether childhood BMI prediction could be improved by combining PGSs and non-genetic factors (maternal and earlier child BMI). SUBJECTS/METHODS: Participants (n = 1365 children, and n = 2094 adults made up of their parents) were drawn from the Longitudinal Study of Australian Children. Children were weighed and measured every two years from 0-1 to 12-13 years, and adults were measured or self-reported measurements were obtained concurrently (average analysed). Participants were genotyped from blood or oral samples, and PGSs were derived based on published genome-wide association studies. We used linear regression to compare the relative utility of these PGSs to predict their respective traits at different ages. RESULTS: BMI PGSs explained up to 12% of child BMI z-score variance in 10-13 year olds, compared with up to 15% in adults. PGSs for waist circumference and body fat explained less variance (up to 8%). An interaction between BMI PGSs and puberty (p = 0.001-0.002) suggests the effect of some variants may differ across the life course. Individual BMI measures across childhood predicted 10-60% of the variance in BMI at 12-13 years, and maternal BMI and BMI PGS each added 1-9% above this. CONCLUSION: Adult-derived PGSs for BMI, particularly those derived by modelling between-variant interactions, may be useful for predicting BMI during adolescence with similar accuracy to that obtained in adulthood. The level of precision presented here to predict BMI during childhood may be relevant to public health, but is likely to be less useful for individual clinical purposes.
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Estudio de Asociación del Genoma Completo , Adolescente , Adulto , Australia/epidemiología , Índice de Masa Corporal , Niño , Humanos , Estudios Longitudinales , Herencia Multifactorial , Circunferencia de la CinturaRESUMEN
The beta-actin gene (ACTB) encodes a ubiquitous cytoskeletal protein, essential for embryonic development in humans. De novo heterozygous missense variants in the ACTB are implicated in causing Baraitser-Winter cerebrofrontofacial syndrome (BWCFFS; MIM#243310). ACTB pathogenic variants are rarely associated with intestinal malformations. We report on a rare case of monozygotic twins presenting with proximal small bowel atresia and hydrops in one, and apple-peel bowel atresia and laryngeal dysgenesis in the other. The twin with hydrops could not be resuscitated. Intensive and surgical care was provided to the surviving twin. Rapid trio genome sequencing identified a de novo missense variant in ACTB (NM_00101.3:c.1043C>T; p.(Ser348Leu)) that guided the care plan. The identical variant subsequently was identified in the demised twin. To characterize the functional effect, the variant was recreated as a pseudoheterozygote in a haploid wild-type S. cerevisiae strain. There was an obvious growth defect of the yACT1S348L/WT pseudoheterozygote compared to a yACT1WT/WT strain when grown at 22°C but not when grown at 30°C, consistent with the yACT1 S348L variant having a functional defect that is dominant over the wild-type allele. The functional results provide supporting evidence that the Ser348Leu variant is likely to be a pathogenic variant, including being associated with intestinal malformations in BWCFFS, and can demonstrate variable expressivity within monozygotic twins.
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Atresia Intestinal , Gemelos Monocigóticos , Actinas/genética , Actinas/metabolismo , Variación Biológica Poblacional , Anomalías Craneofaciales , Edema , Epilepsia , Facies , Humanos , Discapacidad Intelectual , Atresia Intestinal/diagnóstico , Atresia Intestinal/genética , Lisencefalia , Saccharomyces cerevisiae/metabolismo , Gemelos Monocigóticos/genéticaRESUMEN
BACKGROUND: The cohesin complex plays an essential role in genome organisation and cell division. A full complement of the cohesin complex and its regulators is important for normal development, since heterozygous mutations in genes encoding these components can be sufficient to produce a disease phenotype. The implication that genes encoding the cohesin subunits or cohesin regulators must be tightly controlled and resistant to variability in expression has not yet been formally tested. METHODS: Here, we identify spatial-regulatory connections with potential to regulate expression of cohesin loci (Mitotic: SMC1A, SMC3, STAG1, STAG2, RAD21/RAD21-AS; Meiotic: SMC1B, STAG3, REC8, RAD21L1), cohesin-ring support genes (NIPBL, MAU2, WAPL, PDS5A, PDS5B) and CTCF, including linking their expression to that of other genes. We searched the genome-wide association studies (GWAS) catalogue for SNPs mapped or attributed to cohesin genes by GWAS (GWAS-attributed) and the GTEx catalogue for SNPs mapped to cohesin genes by cis-regulatory variants in one or more of 44 tissues across the human body (expression quantitative trail locus-attributed). RESULTS: Connections that centre on the cohesin ring subunits provide evidence of coordinated regulation that has little tolerance for perturbation. We used the CoDeS3D SNP-gene attribution methodology to identify transcriptional changes across a set of genes coregulated with the cohesin loci that include biological pathways such as extracellular matrix production and proteasome-mediated protein degradation. Remarkably, many of the genes that are coregulated with cohesin loci are themselves intolerant to loss-of-function. CONCLUSIONS: The results highlight the importance of robust regulation of cohesin genes and implicate novel pathways that may be important in the human cohesinopathy disorders.
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Proteínas de Ciclo Celular/genética , Proteínas Cromosómicas no Histona/genética , Polimorfismo de Nucleótido Simple/genética , Transcripción Genética/genética , Expresión Génica/genética , Estudio de Asociación del Genoma Completo/métodos , Humanos , Complejo de la Endopetidasa Proteasomal/genética , Proteolisis , Transducción de Señal/genética , CohesinasRESUMEN
At zygotic genome activation (ZGA), changes in chromatin structure are associated with new transcription immediately following the maternal-to-zygotic transition (MZT). The nuclear architectural proteins cohesin and CCCTC-binding factor (CTCF) contribute to chromatin structure and gene regulation. We show here that normal cohesin function is important for ZGA in zebrafish. Depletion of the cohesin subunit Rad21 delays ZGA without affecting cell cycle progression. In contrast, CTCF depletion has little effect on ZGA, whereas complete abrogation is lethal. Genome-wide analysis of Rad21 binding reveals a change in distribution from pericentromeric satellite DNA and other locations, including the miR-430 locus (the products of which are responsible for maternal transcript degradation), to genes, as embryos progress through the MZT. After MZT, a subset of Rad21 binding overlaps the pioneer factor Pou5f3, which activates early expressed genes. Rad21 depletion disrupts the formation of nucleoli and RNA polymerase II foci, suggestive of global defects in chromosome architecture. We propose that Rad21/cohesin redistribution to active areas of the genome is key to the establishment of chromosome organization and the embryonic developmental program.
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Proteínas de Ciclo Celular/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , MicroARNs/metabolismo , Proteínas de Pez Cebra/metabolismo , Pez Cebra/embriología , Cigoto/metabolismo , Animales , Factor de Unión a CCCTC/genética , Factor de Unión a CCCTC/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas Cromosómicas no Histona/genética , Genoma/fisiología , Estudio de Asociación del Genoma Completo , MicroARNs/genética , Pez Cebra/genética , Proteínas de Pez Cebra/genética , Cigoto/citología , CohesinasRESUMEN
BACKGROUND: The first report of children born very preterm (<32 weeks of gestation) having insulin resistance was made 16 years ago. However, neonatal care has improved since. Thus, we aimed to assess whether children born very preterm still have lower insulin sensitivity than term controls. METHODS: Participants were prepubertal children aged 5 to 11 years born very preterm (<32 weeks of gestation; n = 51; 61% boys) or at term (37-41 weeks; n = 50; 62% boys). Frequently sampled intravenous glucose tolerance tests were performed, and insulin sensitivity was calculated using Bergman's minimal model. Additional clinical assessments included anthropometry, body composition using whole-body dual-energy X-ray absorptiometry scans, clinic blood pressure, and 24-hour ambulatory blood pressure monitoring. RESULTS: Children born very preterm were 0.69 standard deviation score (SDS) lighter (P < .001), 0.53 SDS shorter (P = .003), and had body mass index 0.57 SDS lower (P = .003) than children born at term. Notably, children born very preterm had insulin sensitivity that was 25% lower than term controls (9.4 vs 12.6 × 10-4 minutes-1 ·[mU/L]; P = .001). Other parameters of glucose metabolism, including fasting insulin levels, were similar in the two groups. The awake systolic blood pressure (from 24-hour monitoring) tended to be 3.1 mm Hg higher on average in children born very preterm (P = .054), while the clinic systolic blood pressure was 5.4 mm Hg higher (P = .002). CONCLUSIONS: Lower insulin sensitivity remains a feature of children born very preterm, despite improvements in neonatal intensive care. As reported in our original study, our findings suggest the defect in insulin action in prepubertal children born very pretermis primarily peripheral and not hepatic.
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Resistencia a la Insulina , Factores de Edad , Presión Sanguínea , Índice de Masa Corporal , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Edad Gestacional , Prueba de Tolerancia a la Glucosa , Humanos , Recien Nacido Extremadamente Prematuro , Recién Nacido , Masculino , Factores de RiesgoRESUMEN
Cancer cell lines often have large structural variants (SVs) that evolve over time. There are many reported differences in large scale SVs between HL-60 and HL-60/S4, two cell lines derived from the same acute myeloid leukemia sample. However, the stability and variability of inter- and intra-chromosomal structural variants between different sources of the same cell line is unknown. Here, we used Hi-C and RNA-seq to identify and compare large SVs in HL-60 and HL-60/S4 cell lines. Comparisons with previously published karyotypes identified novel SVs in both cell lines. Hi-C was used to characterize the known expansion centered on the MYC locus. The MYC expansion was integrated into known locations in HL-60/S4, and a novel location (chr4) in HL-60. The HL-60 cell line has more within-line structural variation than the HL-60/S4 derivative cell line. Collectively we demonstrate the usefulness of Hi-C and with RNA-seq data for the identification and characterization of SVs.
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Cromosomas Humanos , Variación Genética , Cromatina , Fusión Génica , Genoma Humano , Células HL-60 , Humanos , Cariotipo , Biosíntesis de Proteínas , Proteínas Proto-Oncogénicas c-myc/genética , RNA-SeqRESUMEN
The precise molecular mechanisms by which urate-associated genetic variants affect urate levels are unknown. Here, we tested for functional linkage of the maximally associated genetic variant rs1967017 at the PDZK1 locus to elevated PDZK1 expression. We performed expression quantitative trait loci (eQTL) and likelihood analyses and gene expression assays. Zebrafish were used to evaluate tissue-specific gene expression. Luciferase assays in HEK293 and HepG2 cells measured the effect of rs1967017 on transcription amplitude. Probabilistic Annotation Integrator analysis revealed rs1967017 as most likely to be causal and rs1967017 was an eQTL for PDZK1 in the intestine. The region harboring rs1967017 was capable of directly driving green fluorescent protein expression in the kidney, liver and intestine of zebrafish embryos, consistent with a conserved ability to confer tissue-specific expression. Small interfering RNA depletion of HNF4A reduced endogenous PDZK1 expression in HepG2 cells. Luciferase assays showed that the T allele of rs1967017 gains enhancer activity relative to the urate-decreasing C allele, with T allele enhancer activity abrogated by HNF4A depletion. HNF4A physically binds the rs1967017 region, suggesting direct transcriptional regulation of PDZK1 by HNF4A. Computational prediction of increased motif strength, together with our functional assays, suggests that the urate-increasing T allele of rs1967017 strengthens a binding site for the transcription factor HNF4A. Our and other data predict that the urate-raising T allele of rs1967017 enhances HNF4A binding to the PDZK1 promoter, thereby increasing PDZK1 expression. As PDZK1 is a scaffold protein for many ion channel transporters, increased expression can be predicted to increase activity of urate transporters and alter excretion of urate.
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Proteínas Portadoras/genética , Factor Nuclear 4 del Hepatocito/genética , Sitios de Carácter Cuantitativo/genética , Ácido Úrico/sangre , Animales , Sitios de Unión , Regulación de la Expresión Génica/genética , Células HEK293 , Células Hep G2 , Humanos , Riñón/metabolismo , Riñón/patología , Hígado/metabolismo , Hígado/patología , Proteínas de la Membrana , Especificidad de Órganos , Polimorfismo de Nucleótido Simple/genética , Regiones Promotoras Genéticas , Unión Proteica , ARN Interferente Pequeño/genética , Pez Cebra/genética , Pez Cebra/metabolismoRESUMEN
Gut microbiome transfer (GMT; also referred to as faecal microbiota transplantation or FMT) has been propelled from fringe therapy to mainstream science as a highly effective treatment for recurrent Clostridioides difficile infection. As a result, there has been great interest in the potential efficacy and safety of GMT in treating other medical conditions, for example inflammatory bowel disease, and more recently as a novel therapy for obesity and metabolic diseases. For these chronic conditions, the results from clinical trials have been mixed. Further, specifically in obesity and metabolic diseases, there are limited available data, with only a few published studies with a small number of participants and short duration of follow-up. Therefore, this review aims to explore the human, microbial and formulation factors that may affect the success of GMT. This includes various aspects in the preparation and administration of GMT, such as stool processing, modes of delivery, pretreatment with antibiotics and/or bowel lavage, frequency of GMT and possible use of precision bacteriotherapy. In addition, we examine the potential use of GMT in obesity, type 2 diabetes and metabolic diseases based on current available literature, highlighting some recent advances in GMT research in this area, as well as potential adverse effects after GMT therapy.
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Infecciones por Clostridium , Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Trasplante de Microbiota Fecal , Heces , HumanosRESUMEN
BACKGROUND: GBA mutations are numerically the most significant genetic risk factor for Parkinson's disease (PD), yet these mutations have low penetrance, suggesting additional mechanisms. OBJECTIVES: The objective of this study was to determine if the penetrance of GBA in PD can be explained by regulatory effects on GBA and modifier genes. METHODS: Genetic variants associated with the regulation of GBA were identified by screening 128 common single nucleotide polymorphisms (SNPs) in the GBA locus for spatial cis-expression quantitative trail locus (supported by chromatin interactions). RESULTS: We identified common noncoding SNPs within GBA that (1) regulate GBA expression in peripheral tissues, some of which display α-synuclein pathology and (2) coregulate potential modifier genes in the central nervous system and/or peripheral tissues. Haplotypes based on 3 of these SNPs delay disease onset by 5 years. In addition, SNPs on 6 separate chromosomes coregulate GBA expression specifically in either the substantia nigra or cortex, and their combined effect potentially modulates motor and cognitive symptoms, respectively. CONCLUSIONS: This work provides a new perspective on the haplotype-specific effects of GBA and the genetic etiology of PD, expanding the role of GBA from the gene encoding the ß-glucocerebrosidase (GCase) to that of a central regulator and modifier of PD onset, with GBA expression itself subject to distant regulation. Some idiopathic patients might possess insufficient GBA-encoded GCase activity in the substantia nigra as the result of distant regulatory variants and therefore might benefit from GBA-targeting therapeutics. The SNPs' regulatory impacts provide a plausible explanation for the variable phenotypes also observed in GBA-centric Gaucher's disease and dementia with Lewy bodies. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, LLC on behalf of International Parkinson and Movement Disorder Society.
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Enfermedad de Gaucher , Enfermedad de Parkinson , Enfermedad de Gaucher/genética , Genes Modificadores , Glucosilceramidasa/genética , Humanos , Cuerpos de Lewy , Mutación , Enfermedad de Parkinson/genéticaRESUMEN
Amino acids (AAs) and one-carbon (1-C) metabolism compounds are involved in a range of key metabolic pathways, and mediate numerous health and disease processes in the human body. Previous assays have quantified a limited selection of these compounds and typically require extensive manual handling. Here, we describe the robotic automation of an analytical method for the simultaneous quantification of 37 1-C metabolites, amino acids, and precursors using reversed-phase ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry (UHPLC/MS-MS). Compound extraction from human plasma was tested manually before being robotically automated. The final automated analytical panel was validated on human plasma samples. Our automated and multiplexed method holds promise for application to large cohort studies.
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Aminoácidos/sangre , Automatización de Laboratorios/instrumentación , Cromatografía Líquida de Alta Presión/instrumentación , Robótica , Espectrometría de Masas en Tándem/instrumentación , HumanosRESUMEN
The hepatocyte nuclear factor-1ß (Hnf1b) transcription factor is a key regulator of kidney tubule formation and is associated with a syndrome of renal cysts and early onset diabetes. To further our understanding of Hnf1b in the developing zebrafish kidney, we performed RNA sequencing analysis of proximal tubules from hnf1b-deficient larvae. This analysis revealed an enrichment of gene transcripts encoding transporters of the solute carrier (SLC) superfamily, including multiple members of slc2 and slc5 glucose transporters. An investigation of expression of slc2a1a, slc2a2, and slc5a2 as well as a poorly studied glucose/mannose transporter encoded by slc5a9 revealed that these genes undergo dynamic spatiotemporal changes during tubule formation and maturation. A comparative analysis of zebrafish SLC genes with those expressed in mouse proximal tubules showed a substantial overlap at the level of gene families, indicating a high degree of functional conservation between zebrafish and mammalian proximal tubules. Taken together, our findings are consistent with a role for Hnf1b as a critical determinant of proximal tubule transport function by acting upstream of a large number of SLC genes and validate the zebrafish as a physiologically relevant model of the mammalian proximal tubule.
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Perfilación de la Expresión Génica , Factor Nuclear 1-beta del Hepatocito/genética , Factor Nuclear 1-beta del Hepatocito/fisiología , Túbulos Renales Proximales/metabolismo , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/fisiología , Pez Cebra/genética , Animales , Animales Modificados Genéticamente , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Regulación del Desarrollo de la Expresión Génica , Larva , Ratones , ARN/biosíntesis , ARN/genética , Especificidad de la EspecieRESUMEN
BACKGROUND: Gestation is a crucial timepoint in human development. Deviation from a term gestational age correlates with both acute and long-term adverse health effects for the child. Both being born preterm and post-term, that is, having short and long gestational ages, are heritable and influenced by the prenatal and perinatal environment. Despite the obvious heritable component, specific genetic influences underlying differences in gestational age are poorly understood. METHODS: We investigated the genetic architecture of gestational age in 9141 individuals, including 1167 born post-term, across two Northern Finland cohorts born in 1966 or 1986. RESULTS: Here we identify one globally significant intronic genetic variant within the ADAMTS13 gene that is associated with prolonged gestation (p=4.85×10-8). Additional variants that reached suggestive levels of significance were identified within introns at the ARGHAP42 and TKT genes, and in the upstream (5') intergenic regions of the B3GALT5 and SSBP2 genes. The variants near the ADAMTS13, B3GALT5, SSBP2 and TKT loci are linked to alterations in gene expression levels (cis-eQTLs). Luciferase assays confirmed the allele specific enhancer activity for the BGALT5 and TKT loci. CONCLUSIONS: Our findings provide the first evidence of a specific genetic influence associated with prolonged gestation. This study forms a foundation for a better understanding of the genetic and long-term health risks faced by induced and post-term individuals. The long-term risks for induced individuals who have a previously overlooked post-term potential may be a major issue for current health providers.
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Estudio de Asociación del Genoma Completo , Nacimiento a Término/genética , Alelos , Estudios de Cohortes , Elementos de Facilitación Genéticos/genética , Femenino , Finlandia , Regulación de la Expresión Génica , Variación Genética , Humanos , Recién Nacido , Luciferasas/metabolismo , Polimorfismo de Nucleótido Simple/genética , Embarazo , Sitios de Carácter Cuantitativo/genética , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Mammalian cells are flexible and can rapidly change shape when they contract, adhere, or migrate. The nucleus must be stiff enough to withstand cytoskeletal forces, but flexible enough to remodel as the cell changes shape. This is particularly important for cells migrating through confined spaces, where the nuclear shape must change in order to fit through a constriction. This occurs many times in the life cycle of a neutrophil, which must protect its chromatin from damage and disruption associated with migration. Here we characterized the effects of constricted migration in neutrophil-like cells. RESULTS: Total RNA sequencing identified that migration of neutrophil-like cells through 5- or 14-µm pores was associated with changes in the transcript levels of inflammation and chemotaxis-related genes when compared to unmigrated cells. Differentially expressed transcripts specific to migration with constriction were enriched for groups of genes associated with cytoskeletal remodeling. Hi-C was used to capture the genome organization in control and migrated cells. Limited switching was observed between the active (A) and inactive (B) compartments after migration. However, global depletion of short-range contacts was observed following migration with constriction compared to migration without constriction. Regions with disrupted contacts, TADs, and compartments were enriched for inactive chromatin. CONCLUSION: Short-range genome organization is preferentially altered in inactive chromatin, possibly protecting transcriptionally active contacts from the disruptive effects of migration with constriction. This is consistent with current hypotheses implicating heterochromatin as the mechanoresponsive form of chromatin. Further investigation concerning the contribution of heterochromatin to stiffness, flexibility, and protection of nuclear function will be important for understanding cell migration in relation to human health and disease.
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Núcleo Celular/química , Cromatina/química , Neutrófilos/química , Células HL-60 , HumanosRESUMEN
The loss of muscle size, strength, and quality with aging is a major determinant of morbidity and mortality in the elderly. The regulatory pathways that impact the muscle phenotype include the translational regulation maintained by microRNAs (miRNA). Yet the miRNAs that are expressed in human skeletal muscle and relationship to muscle size, strength, and quality are unknown. Using next-generation sequencing, we selected the 50 most abundantly expressed miRNAs and then analyzed them in vastus lateralis muscle, obtained by biopsy from middle-aged males ( n = 48; 50.0 ± 4.3 yr). Isokinetic strength testing and midthigh computed tomography was undertaken for muscle phenotype analysis. Muscle attenuation was measured by computerized tomography and is inversely proportional to myofiber lipid content. miR-486-5p accounted for 21% of total miR sequence reads, with miR-10b-5p, miR-133a-3p, and miR-22-3p accounting for a further 15, 12, and 10%, respectively. Isokinetic knee extension strength and muscle cross-sectional area were positively correlated with miR-100-5p, miR-99b-5p, and miR-191-5p expression. Muscle attenuation was negatively correlated to let-7f-5p, miR-30d-5p, and miR-125b-5p expression. In silico analysis implicates miRNAs related to strength and muscle size in the regulation of mammalian target of rapamycin, while miRNAs related to muscle attenuation may have potential roles regulating the transforming growth factor-ß/SMAD3 pathway.
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Secuenciación de Nucleótidos de Alto Rendimiento/métodos , MicroARNs/genética , Músculo Esquelético/metabolismo , Regulación de la Expresión Génica , Humanos , Masculino , MicroARNs/metabolismo , Persona de Mediana Edad , Fuerza Muscular/genética , Cadenas Pesadas de Miosina/genética , Cadenas Pesadas de Miosina/metabolismo , Fenotipo , Análisis de Componente Principal , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los ResultadosRESUMEN
Meta-analysis of genome-wide association studies has resulted in the identification of hundreds of genetic variants associated with growth and stature. Determining how these genetic variants influence growth is important, but most are non-coding, and there is little understanding of how these variants contribute to adult height. To determine the mechanisms by which human variation contributes to growth, we combined spatial genomic connectivity (high-throughput conformation capture) with functional (gene expression, expression Quantitative Trait Loci) data to determine how non-genic loci associated with infant length, pubertal and adult height and contribute to gene regulatory networks. This approach identified intergenic single-nucleotide polymorphisms (SNPs) â¼85 kb upstream of FBXW11 that spatially connect with distant loci. These regulatory connections are reinforced by evidence of SNP-enhancer effects and altered expression in genes influencing the action of human growth hormone. Functional assays provided evidence for enhancer activity of the intergenic region near FBXW11 that harbors SNP rs12153391, which is associated with an expression Quantitative Trait Loci. Our results suggest that variants in this locus have genome-wide effects as key modifiers of growth (both overgrowth and short stature) acting through a regulatory network. We believe that the genes and pathways connected with this regulatory network are potential targets that could be investigated for diagnostic, prenatal and carrier testing for growth disorders. Finally, the regulatory networks we generated illustrate the power of using existing datasets to interrogate the contribution of intergenic SNPs to common syndromes/diseases.