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Variants at the SLC30A8 locus are associated with type 2 diabetes (T2D) risk. The lead variant, rs13266634, encodes an amino acid change, Arg325Trp (R325W), at the C-terminus of the secretory granule-enriched zinc transporter, ZnT8. Although this protein-coding variant was previously thought to be the sole driver of T2D risk at this locus, recent studies have provided evidence for lowered expression of SLC30A8 mRNA in protective allele carriers. In the present study, we examined multiple variants that influence SLC30A8 allele-specific expression. Epigenomic mapping has previously identified an islet-selective enhancer cluster at the SLC30A8 locus, hosting multiple T2D risk and cASE associations, which is spatially associated with the SLC30A8 promoter and additional neighboring genes. Here, we show that deletion of variant-bearing enhancer regions using CRISPR-Cas9 in human-derived EndoC-ßH3 cells lowers the expression of SLC30A8 and several neighboring genes and improves glucose-stimulated insulin secretion. While downregulation of SLC30A8 had no effect on beta cell survival, loss of UTP23, RAD21, or MED30 markedly reduced cell viability. Although eQTL or cASE analyses in human islets did not support the association between these additional genes and diabetes risk, the transcriptional regulator JQ1 lowered the expression of multiple genes at the SLC30A8 locus and enhanced stimulated insulin secretion.
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Diabetes Mellitus Tipo 2 , Elementos de Facilitación Genéticos , Células Secretoras de Insulina , Transportador 8 de Zinc , Humanos , Transportador 8 de Zinc/genética , Transportador 8 de Zinc/metabolismo , Células Secretoras de Insulina/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Supervivencia Celular/genética , Variación Genética , Insulina/metabolismo , Línea CelularRESUMEN
Obesity represents an escalating global health burden with profound medical and economic impacts. The conventional perspective on obesity revolves around its classification as a "pure" metabolic disorder, marked by an imbalance between calorie consumption and energy expenditure. Present knowledge, however, recognizes the intricate interaction of rare or frequent genetic factors that favor the development of obesity, together with the emergence of neurodevelopmental and mental abnormalities, phenotypes that are modulated by environmental factors such as lifestyle. Thirty years of human genetic research has unveiled >20 genes, causing severe early-onset monogenic obesity and ~1000 loci associated with common polygenic obesity, most of those expressed in the brain, depicting obesity as a neurological and mental condition. Therefore, obesity's association with brain function should be better recognized. In this context, this review seeks to broaden the current perspective by elucidating the genetic determinants that contribute to both obesity and neurodevelopmental and mental dysfunctions. We conduct a detailed examination of recent genetic findings, correlating them with clinical and behavioral phenotypes associated with obesity. This includes how polygenic obesity, influenced by a myriad of genetic variants, impacts brain regions associated with addiction and reward, differentiating it from monogenic forms. The continuum between non-syndromic and syndromic monogenic obesity, with evidence from neurodevelopmental and cognitive assessments, is also addressed. Current therapeutic approaches that target these genetic mechanisms, yielding improved clinical outcomes and cognitive advantages, are discussed. To sum up, this review corroborates the genetic underpinnings of obesity, affirming its classification as a neurological disorder that may have broader implications for neurodevelopmental and mental conditions. It highlights the promising intersection of genetics, genomics, and neurobiology as a foundation for developing tailored medical approaches to treat obesity and its related neurological aspects.
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Bridging Integrator 1 (BIN1) is the second most important Alzheimer's disease (AD) risk gene, but its physiological roles in neurons and its contribution to brain pathology remain largely elusive. In this work, we show that BIN1 plays a critical role in the regulation of calcium homeostasis, electrical activity, and gene expression of glutamatergic neurons. Using single-cell RNA-sequencing on cerebral organoids generated from isogenic BIN1 wild type (WT), heterozygous (HET) and homozygous knockout (KO) human-induced pluripotent stem cells (hiPSCs), we show that BIN1 is mainly expressed by oligodendrocytes and glutamatergic neurons, like in the human brain. Both BIN1 HET and KO cerebral organoids show specific transcriptional alterations, mainly associated with ion transport and synapses in glutamatergic neurons. We then demonstrate that BIN1 cell-autonomously regulates gene expression in glutamatergic neurons by using a novel protocol to generate pure culture of hiPSC-derived induced neurons (hiNs). Using this system, we also show that BIN1 plays a key role in the regulation of neuronal calcium transients and electrical activity via its interaction with the L-type voltage-gated calcium channel Cav1.2. BIN1 KO hiNs show reduced activity-dependent internalization and higher Cav1.2 expression compared to WT hiNs. Pharmacological blocking of this channel with clinically relevant doses of nifedipine, a calcium channel blocker, partly rescues electrical and gene expression alterations in BIN1 KO glutamatergic neurons. Further, we show that transcriptional alterations in BIN1 KO hiNs that affect biological processes related to calcium homeostasis are also present in glutamatergic neurons of the human brain at late stages of AD pathology. Together, these findings suggest that BIN1-dependent alterations in neuronal properties could contribute to AD pathophysiology and that treatment with low doses of clinically approved calcium blockers should be considered as an option to slow disease-onset and progression.
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Proteínas Adaptadoras Transductoras de Señales , Enfermedad de Alzheimer , Células Madre Pluripotentes Inducidas , Neuronas , Proteínas Supresoras de Tumor , Humanos , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genética , Células Madre Pluripotentes Inducidas/metabolismo , Neuronas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Ácido Glutámico/metabolismo , Calcio/metabolismo , Canales de Calcio Tipo L/metabolismo , Canales de Calcio Tipo L/genética , Encéfalo/metabolismo , Expresión Génica/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismoRESUMEN
INTRODUCTION: Polygenic score (PGS) is a valuable method for assessing the estimated genetic liability to a given outcome or genetic variability contributing to a quantitative trait. While polygenic risk scores are widely used for complex traits, their application in uncovering shared genetic predisposition between phenotypes, i.e., when genetic variants influence more than one phenotype, remains limited. METHODS: We developed an R package, comorbidPGS, which facilitates a systematic evaluation of shared genetic effects among (cor)related phenotypes using PGSs. The comorbidPGS package takes as input a set of single nucleotide polymorphisms along with their established effects on the original phenotype (Po), referred to as Po-PGS. It generates a comprehensive summary of effect(s) of Po-PGS on target phenotype(s) (Pt) with customisable graphical features. RESULTS: We applied comorbidPGS to investigate the shared genetic predisposition between phenotypes defining elevated blood pressure (systolic blood pressure, SBP; diastolic blood pressure, DBP; pulse pressure) and several cancers (breast cancer; pancreatic cancer, PanC; kidney cancer, KidC; prostate cancer, PrC; colorectal cancer, CrC) using the European ancestry UK Biobank individuals and GWAS meta-analyses summary statistics from independent set of European ancestry individuals. We report a significant association between elevated DBP and the genetic risk of PrC (ß [SE] = 0.066 [0.017], p value = 9.64 × 10-5), as well as between CrC PGS and both, lower SBP (ß [SE] = -0.10 [0.029], p value = 3.83 × 10-4) and lower DBP (ß [SE] = -0.055 [0.017], p value = 1.05 × 10-3). Our analysis highlights two nominally significant relationships for individuals with genetic predisposition to elevated SBP leading to higher risk of KidC (OR [95% CI] = 1.04 [1.0039-1.087], p value = 2.82 × 10-2) and PrC (OR [95% CI] = 1.02 [1.003-1.041], p value = 2.22 × 10-2). CONCLUSION: Using comorbidPGS, we underscore mechanistic relationships between blood pressure regulation and susceptibility to three comorbid malignancies. This package offers valuable means to evaluate shared genetic susceptibility between (cor)related phenotypes through polygenic scores.
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Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Herencia Multifactorial , Fenotipo , Polimorfismo de Nucleótido Simple , Humanos , Herencia Multifactorial/genética , Polimorfismo de Nucleótido Simple/genética , Masculino , Femenino , Neoplasias/genética , Programas Informáticos , Presión Sanguínea/genéticaRESUMEN
AIMS/HYPOTHESIS: GLIS3 encodes a transcription factor involved in pancreatic beta cell development and function. Rare pathogenic, bi-allelic mutations in GLIS3 cause syndromic neonatal diabetes whereas frequent SNPs at this locus associate with common type 2 diabetes risk. Because rare, functional variants located in other susceptibility genes for type 2 diabetes have already been shown to strongly increase individual risk for common type 2 diabetes, we aimed to investigate the contribution of rare pathogenic GLIS3 variants to type 2 diabetes. METHODS: GLIS3 was sequenced in 5471 individuals from the Rare Variants Involved in Diabetes and Obesity (RaDiO) study. Variant pathogenicity was assessed following the criteria established by the American College of Medical Genetics and Genomics (ACMG). To address the pathogenic strong criterion number 3 (PS3), we conducted functional investigations of these variants using luciferase assays, focusing on capacity of GLIS family zinc finger 3 (GLIS3) to bind to and activate the INS promoter. The association between rare pathogenic or likely pathogenic (P/LP) variants and type 2 diabetes risk (and other metabolic traits) was then evaluated. A meta-analysis combining association results from RaDiO, the 52K study (43,125 individuals) and the TOPMed study (44,083 individuals) was finally performed. RESULTS: Through targeted resequencing of GLIS3, we identified 105 rare variants that were carried by 395 participants from RaDiO. Among them, 49 variants decreased the activation of the INS promoter. Following ACMG criteria, 18 rare variants were classified as P/LP, showing an enrichment in the last two exons compared with the remaining exons (p<5×10-6; OR>3.5). The burden of these P/LP variants was strongly higher in individuals with type 2 diabetes (p=3.0×10-3; OR 3.9 [95% CI 1.4, 12]), whereas adiposity, age at type 2 diabetes diagnosis and cholesterol levels were similar between variant carriers and non-carriers with type 2 diabetes. Interestingly, all carriers with type 2 diabetes were sensitive to oral sulfonylureas. A total of 7 P/LP variants were identified in both 52K and TOPMed studies. The meta-analysis of association studies obtained from RaDiO, 52K and TOPMed showed an enrichment of P/LP GLIS3 variants in individuals with type 2 diabetes (p=5.6×10-5; OR 2.1 [95% CI 1.4, 2.9]). CONCLUSIONS/INTERPRETATION: Rare P/LP GLIS3 variants do contribute to type 2 diabetes risk. The variants located in the distal part of the protein could have a direct effect on its functional activity by impacting its transactivation domain, by homology with the mouse GLIS3 protein. Furthermore, rare P/LP GLIS3 variants seem to have a direct clinical effect on beta cell function, which could be improved by increasing insulin secretion via the use of sulfonylureas.
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Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Ratones , Animales , Recién Nacido , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regulación de la Expresión Génica , Células Secretoras de Insulina/metabolismo , Mutación , Proteínas de Unión al ADN/metabolismo , Proteínas Represoras/metabolismo , Transactivadores/metabolismoRESUMEN
Gestational diabetes mellitus (GDM) is associated with increased risk of pregnancy complications and adverse perinatal outcomes. GDM often reoccurs and is associated with increased risk of subsequent diagnosis of type 2 diabetes (T2D). To improve our understanding of the aetiological factors and molecular processes driving the occurrence of GDM, including the extent to which these overlap with T2D pathophysiology, the GENetics of Diabetes In Pregnancy Consortium assembled genome-wide association studies of diverse ancestry in a total of 5485 women with GDM and 347 856 without GDM. Through multi-ancestry meta-analysis, we identified five loci with genome-wide significant association (P < 5 × 10-8) with GDM, mapping to/near MTNR1B (P = 4.3 × 10-54), TCF7L2 (P = 4.0 × 10-16), CDKAL1 (P = 1.6 × 10-14), CDKN2A-CDKN2B (P = 4.1 × 10-9) and HKDC1 (P = 2.9 × 10-8). Multiple lines of evidence pointed to the shared pathophysiology of GDM and T2D: (i) four of the five GDM loci (not HKDC1) have been previously reported at genome-wide significance for T2D; (ii) significant enrichment for associations with GDM at previously reported T2D loci; (iii) strong genetic correlation between GDM and T2D and (iv) enrichment of GDM associations mapping to genomic annotations in diabetes-relevant tissues and transcription factor binding sites. Mendelian randomization analyses demonstrated significant causal association (5% false discovery rate) of higher body mass index on increased GDM risk. Our results provide support for the hypothesis that GDM and T2D are part of the same underlying pathology but that, as exemplified by the HKDC1 locus, there are genetic determinants of GDM that are specific to glucose regulation in pregnancy.
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Diabetes Mellitus Tipo 2 , Diabetes Gestacional , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/genética , Diabetes Gestacional/genética , Femenino , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Glucosa , Humanos , Polimorfismo de Nucleótido Simple/genética , EmbarazoRESUMEN
AIMS: Although highly heritable, the genetic etiology of calcific aortic stenosis (AS) remains incompletely understood. The aim of this study was to discover novel genetic contributors to AS and to integrate functional, expression, and cross-phenotype data to identify mechanisms of AS. METHODS AND RESULTS: A genome-wide meta-analysis of 11.6 million variants in 10 cohorts involving 653 867 European ancestry participants (13 765 cases) was performed. Seventeen loci were associated with AS at P ≤ 5 × 10-8, of which 15 replicated in an independent cohort of 90 828 participants (7111 cases), including CELSR2-SORT1, NLRP6, and SMC2. A genetic risk score comprised of the index variants was associated with AS [odds ratio (OR) per standard deviation, 1.31; 95% confidence interval (CI), 1.26-1.35; P = 2.7 × 10-51] and aortic valve calcium (OR per standard deviation, 1.22; 95% CI, 1.08-1.37; P = 1.4 × 10-3), after adjustment for known risk factors. A phenome-wide association study indicated multiple associations with coronary artery disease, apolipoprotein B, and triglycerides. Mendelian randomization supported a causal role for apolipoprotein B-containing lipoprotein particles in AS (OR per g/L of apolipoprotein B, 3.85; 95% CI, 2.90-5.12; P = 2.1 × 10-20) and replicated previous findings of causality for lipoprotein(a) (OR per natural logarithm, 1.20; 95% CI, 1.17-1.23; P = 4.8 × 10-73) and body mass index (OR per kg/m2, 1.07; 95% CI, 1.05-1.9; P = 1.9 × 10-12). Colocalization analyses using the GTEx database identified a role for differential expression of the genes LPA, SORT1, ACTR2, NOTCH4, IL6R, and FADS. CONCLUSION: Dyslipidemia, inflammation, calcification, and adiposity play important roles in the etiology of AS, implicating novel treatments and prevention strategies.
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Estenosis de la Válvula Aórtica , Dislipidemias , Humanos , Estudio de Asociación del Genoma Completo/métodos , Adiposidad/genética , Predisposición Genética a la Enfermedad , Estenosis de la Válvula Aórtica/genética , Obesidad , Factores de Riesgo , Inflamación , Dislipidemias/complicaciones , Dislipidemias/genética , Apolipoproteínas/genética , Análisis de la Aleatorización Mendeliana , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Inflammation has been associated with renal diseases. The Interferon Regulatory Factor (IRF)-5 is a key transcription factor in the pro-inflammatory polarization of M1-like macrophages. GWAS have reported that the IRF5 locus is associated with autoimmune diseases and with the estimated glomerular filtration rate (eGFR). We study whether allelic variations in IRF5 are associated with the incidence of chronic kidney disease (CKD) in a general population. We genotyped eleven IRF5 SNPs in the French D.E.S.I.R. cohort from the general population (n = 4820). Associations of SNPs with baseline renal parameters were assessed. Data were analyzed for three endpoints during a 9-year follow-up, incidence of:at least stage 3 CKD, the KDIGO criterion "certain drop in eGFR", and incidence of micro/macro albuminuria. In the cross-sectional analysis, rs10954213 and rs10954214 were associated with eGFR and rs1874328 with urinary albumin/creatinine ratio (ACR). Rs3807306, rs11761199, rs78658945, rs1874328, rs10954213 and rs11770589 were associated with the incidence of stage 3 CKD in multi-adjusted models. Rs4731532, rs3807306, and rs11761199 were associated with the incidence of CKD defined by the KDIGO. Rs4731532, rs3807306, rs11761199 and rs79288514 were associated with the incidence of micro/macro albuminuria. Our results support the hypothesis of the importance of IRF5 mediated macrophage polarization in the etiology of CKD.
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Albuminuria , Insuficiencia Renal Crónica , Humanos , Albuminuria/complicaciones , Albuminuria/epidemiología , Factor V , Incidencia , Estudios Transversales , Interferones , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/genética , Insuficiencia Renal Crónica/complicaciones , Factores Reguladores del Interferón/genética , Factores de RiesgoRESUMEN
PURPOSE: Recessive deficiency of proopiomelanocortin (POMC) causes childhood-onset severe obesity. Cases can now benefit from the melanocortin 4 receptor agonist setmelanotide. Furthermore, a phase 3 clinical trial is evaluating setmelanotide in heterozygotes for POMC. We performed a large-scale genetic analysis to assess the effect of heterozygous, pathogenic POMC variants on obesity. METHODS: A genetic analysis was performed in a family including 2 cousins with childhood-onset obesity. We analyzed the obesity status of heterozygotes for pathogenic POMC variants in the Human Gene Mutation Database. The association between heterozygous pathogenic POMC variants and obesity risk was assessed using 190,000 exome samples from UK Biobank. RESULTS: The 2 cousins carried a compound heterozygous pathogenic variant in POMC. Six siblings were heterozygotes; only 1 of them had obesity. In Human Gene Mutation Database, we identified 60 heterozygotes for pathogenic POMC variants, of whom 14 had obesity. In UK Biobank, heterozygous pathogenic POMC variants were not associated with obesity risk, but they modestly increased body mass index levels. CONCLUSION: Heterozygous pathogenic POMC variants do not contribute to monogenic obesity, but they slightly increase body mass index. Setmelanotide use in patients with obesity, which would only be based on the presence of a heterozygous POMC variant, can be questioned.
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Obesidad Infantil , Proopiomelanocortina , Niño , Humanos , Índice de Masa Corporal , Heterocigoto , Mutación , Obesidad/genética , Obesidad Infantil/genética , Proopiomelanocortina/genética , Receptor de Melanocortina Tipo 4/genética , Receptor de Melanocortina Tipo 4/agonistas , Fármacos Antiobesidad/uso terapéuticoRESUMEN
AIM: To determine the kinase activity profiles of human pancreatic beta cells downstream of glucagon-like peptide-1 receptor (GLP-1R) balanced versus biased agonist stimulations. MATERIALS AND METHODS: This study analysed the kinomic profiles of human EndoC-ßh1 cells following vehicle and GLP-1R stimulation with the pharmacological agonist exendin-4, as well as exendin-4-based biased derivatives exendin-phe1 and exendin-asp3 for acute (10-minute) versus sustained (120-minute) responses, using PamChip protein tyrosine kinase and serine/threonine kinase assays. The raw data were filtered and normalized using BioNavigator. The kinase analyses were conducted with R, mainly including kinase-substrate mapping and Kyoto Encyclopedia of Genes and Genomes pathway analysis. RESULTS: The present analysis reveals that kinomic responses are distinct for acute versus sustained GLP-1R agonist exposure, with individual responses associated with agonists presenting specific bias profiles. According to pathway analysis, several kinases, including JNKs, PKCs, INSR and LKB1, are important GLP-1R signalling mediators, constituting potential targets for further research on biased GLP-1R downstream signalling. CONCLUSION: The results from this study suggest that differentially biased exendin-phe1 and exendin-asp3 can modulate distinct kinase interaction networks. Further understanding of these mechanisms will have important implications for the selection of appropriate anti-type 2 diabetes therapies with optimized downstream kinomic profiles.
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Receptor del Péptido 1 Similar al Glucagón , Células Secretoras de Insulina , Humanos , Exenatida/farmacología , Receptor del Péptido 1 Similar al Glucagón/agonistas , Células Secretoras de Insulina/metabolismo , Transducción de SeñalRESUMEN
BACKGROUND: Nephrolithiasis (NL) is a complex multifactorial disease affecting up to 10%-20% of the human population and causing a significant burden on public health systems worldwide. It results from a combination of environmental and genetic factors. Hyperoxaluria is a major risk factor for NL. METHODS: We used a whole exome-based approach in a patient with calcium oxalate NL. The effects of the mutation were characterised using cell culture and in silico analyses. RESULTS: We identified a rare heterozygous missense mutation (c.1519C>T/p.R507W) in the SLC26A6 gene that encodes a secretory oxalate transporter. This mutation cosegregated with hyperoxaluria in the family. In vitro characterisation of mutant SLC26A6 demonstrated that Cl--dependent oxalate transport was dramatically reduced because the mutation affects both SLC26A6 transport activity and membrane surface expression. Cotransfection studies demonstrated strong dominant-negative effects of the mutant on the wild-type protein indicating that the phenotype of patients heterozygous for this mutation may be more severe than predicted by haploinsufficiency alone. CONCLUSION: Our study is in line with previous observations made in the mouse showing that SLC26A6 inactivation can cause inherited enteric hyperoxaluria with calcium oxalate NL. Consistent with an enteric form of hyperoxaluria, we observed a beneficial effect of increasing calcium in the patient's diet to reduce urinary oxalate excretion.
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Antiportadores , Hiperoxaluria , Nefrolitiasis , Transportadores de Sulfato , Humanos , Antiportadores/genética , Calcio/metabolismo , Oxalato de Calcio/metabolismo , Hiperoxaluria/complicaciones , Hiperoxaluria/genética , Mutación , Nefrolitiasis/genética , Nefrolitiasis/complicaciones , Nefrolitiasis/metabolismo , Oxalatos/metabolismo , Transportadores de Sulfato/genéticaRESUMEN
Integration of genomic and other data has begun to stratify type 2 diabetes in prognostically meaningful ways, but this has yet to impact on mainstream diabetes practice. The subgroup of diabetes caused by single gene defects thus provides the best example to date of the vision of 'precision diabetes'. Monogenic diabetes may be divided into primary pancreatic beta cell failure, and primary insulin resistance. In both groups, clear examples of genotype-selective responses to therapy have been advanced. The benign trajectory of diabetes due to pathogenic GCK mutations, and the sulfonylurea-hyperresponsiveness conferred by activating KCNJ11 or ABCC8 mutations, or loss-of-function HNF1A or HNF4A mutations, often decisively guide clinical management. In monogenic insulin-resistant diabetes, subcutaneous leptin therapy is beneficial in some severe lipodystrophy. Increasing evidence also supports use of 'obesity therapies' in lipodystrophic people even without obesity. In beta cell diabetes the main challenge is now implementation of the precision diabetes vision at scale. In monogenic insulin-resistant diabetes genotype-specific benefits are proven in far fewer patients to date, although further genotype-targeted therapies are being evaluated. The conceptual paradigm established by the insulin-resistant subgroup with 'adipose failure' may have a wider influence on precision therapy for common type 2 diabetes, however. For all forms of monogenic diabetes, population-wide genome sequencing is currently forcing reappraisal of the importance assigned to pathogenic mutations when gene sequencing is uncoupled from prior suspicion of monogenic diabetes.
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Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/genética , Humanos , Insulina/uso terapéutico , Resistencia a la Insulina/genética , Leptina/uso terapéutico , Mutación/genética , ObesidadRESUMEN
Unveiling the key pathways underlying postnatal beta-cell proliferation can be instrumental to decipher the mechanisms of beta-cell mass plasticity to increased physiological demand of insulin during weight gain and pregnancy. Using transcriptome and global Serine Threonine Kinase activity (STK) analyses of islets from newborn (10 days old) and adult rats, we found that highly proliferative neonatal rat islet cells display a substantially elevated activity of the mitogen activated protein 3 kinase 12, also called dual leucine zipper-bearing kinase (Dlk). As a key upstream component of the c-Jun amino terminal kinase (Jnk) pathway, Dlk overexpression was associated with increased Jnk3 activity and was mainly localized in the beta-cell cytoplasm. We provide the evidence that Dlk associates with and activates Jnk3, and that this cascade stimulates the expression of Ccnd1 and Ccnd2, two essential cyclins controlling postnatal beta-cell replication. Silencing of Dlk or of Jnk3 in neonatal islet cells dramatically hampered primary beta-cell replication and the expression of the two cyclins. Moreover, the expression of Dlk, Jnk3, Ccnd1 and Ccnd2 was induced in high replicative islet beta cells from ob/ob mice during weight gain, and from pregnant female rats. In human islets from non-diabetic obese individuals, DLK expression was also cytoplasmic and the rise of the mRNA level was associated with an increase of JNK3, CCND1 and CCND2 mRNA levels, when compared to islets from lean and obese patients with diabetes. In conclusion, we find that activation of Jnk3 signalling by Dlk could be a key mechanism for adapting islet beta-cell mass during postnatal development and weight gain.
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Células Secretoras de Insulina/metabolismo , Quinasas Quinasa Quinasa PAM/metabolismo , Proteína Quinasa 10 Activada por Mitógenos/metabolismo , Transducción de Señal , Animales , Proliferación Celular/efectos de los fármacos , Ciclina D1/genética , Ciclina D1/metabolismo , Ciclina D2/genética , Ciclina D2/metabolismo , Femenino , Glucosa/farmacología , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/citología , Quinasas Quinasa Quinasa PAM/antagonistas & inhibidores , Quinasas Quinasa Quinasa PAM/genética , Ratones , Ratones Endogámicos C57BL , Proteína Quinasa 10 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 10 Activada por Mitógenos/genética , Obesidad/metabolismo , Obesidad/patología , Páncreas/crecimiento & desarrollo , Páncreas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacosRESUMEN
Excessive fetal growth is associated with DNA methylation alterations in human hematopoietic stem and progenitor cells (HSPC), but their functional impact remains elusive. We implemented an integrative analysis combining single-cell epigenomics, single-cell transcriptomics, and in vitro analyses to functionally link DNA methylation changes to putative alterations of HSPC functions. We showed in hematopoietic stem cells (HSC) from large for gestational age neonates that both DNA hypermethylation and chromatin rearrangements target a specific network of transcription factors known to sustain stem cell quiescence. In parallel, we found a decreased expression of key genes regulating HSC differentiation including EGR1, KLF2, SOCS3, and JUNB. Our functional analyses showed that this epigenetic programming was associated with a decreased ability for HSCs to remain quiescent. Taken together, our multimodal approach using single-cell (epi)genomics showed that human fetal overgrowth affects hematopoietic stem cells' quiescence signaling via epigenetic programming.
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Diabetes Gestacional , Transcriptoma , Diabetes Gestacional/metabolismo , Epigénesis Genética , Epigenómica , Femenino , Macrosomía Fetal/genética , Edad Gestacional , Hematopoyesis/genética , Células Madre Hematopoyéticas/metabolismo , Humanos , Recién Nacido , EmbarazoRESUMEN
SUMMARY: The NanoStringTM nCounter® is a platform for the targeted quantification of expression data in biofluids and tissues. While software by the manufacturer is available in addition to third parties packages, they do not provide a complete quality control (QC) pipeline. Here, we present NACHO ('NAnostring quality Control dasHbOard'), a comprehensive QC R-package. The package consists of three subsequent steps: summarize, visualize and normalize. The summarize function collects all the relevant data and stores it in a tidy format, the visualize function initiates a dashboard with plots of the relevant QC outcomes. It contains QC metrics that are measured by default by the manufacturer, but also calculates other insightful measures, including the scaling factors that are needed in the normalization step. In this normalization step, different normalization methods can be chosen to optimally preprocess data. Together, NACHO is a comprehensive method that optimizes insight and preprocessing of nCounter® data. AVAILABILITY AND IMPLEMENTATION: NACHO is available as an R-package on CRAN and the development version on GitHub https://github.com/mcanouil/NACHO. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Programas Informáticos , Control de CalidadRESUMEN
BACKGROUND: Genome-wide association studies (GWAS) have identified more than 250 loci associated with body mass index (BMI) and obesity. However, post-GWAS functional genomic investigations have been inadequate for understanding how these genetic loci physiologically impact disease development. METHODS: We performed a PCR-free expression assay targeting genes located nearby the GWAS-identified SNPs associated with BMI/obesity in a large panel of human tissues. Furthermore, we analyzed several genetic risk scores (GRS) summing GWAS-identified alleles associated with increased BMI in 4236 individuals. RESULTS: We found that the expression of BMI/obesity susceptibility genes was strongly enriched in the brain, especially in the insula (p = 4.7 × 10-9) and substantia nigra (p = 6.8 × 10-7), which are two brain regions involved in addiction and reward. Inversely, we found that top obesity/BMI-associated loci, including FTO, showed the strongest gene expression enrichment in the two brain regions. CONCLUSIONS: Our data suggest for the first time that the susceptibility genes for common obesity may have an effect on eating addiction and reward behaviors through their high expression in substantia nigra and insula, i.e., a different pattern from monogenic obesity genes that act in the hypothalamus and cause hyperphagia. Further epidemiological studies with relevant food behavior phenotypes are necessary to confirm these findings.
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Conducta Adictiva/genética , Corteza Cerebral/metabolismo , Obesidad , Recompensa , Sustancia Negra/metabolismo , Adulto , Índice de Masa Corporal , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Humanos , Hiperfagia , Persona de Mediana Edad , Obesidad/genética , Obesidad/metabolismo , Polimorfismo de Nucleótido SimpleRESUMEN
Background Growing evidence reports an association between inflammatory markers, obesity and blood pressure (BP). Specifically, the intergenic single nucleotide polymorphism (SNP) rs7556897T > C (MAF = 0.34) located between SLC19A3 and the CCL20 was shown to be associated with chronic inflammatory diseases. In addition, CCL20 expression was found increased in pancreatic islets of obese rodents and human pancreatic ß cells under the influence of inflammation. In this study, we hypothesized that SNP rs7556897 could affect BP levels, thus providing a link between inflammation, BP and obesity. Methods BP was measured under supine position with a manual sphygmomanometer; values reported were the means of three readings. We analyzed rs7556897 in 577 normal weight and 689 obese French children. Using real-time polymerase chain reaction (PCR), we quantified CCL20 and SLC19A3 expression in adipose tissue and peripheral blood mononuclear cells (PBMCs) of normal weight and overweight children. Results The rs7556897C allele was negatively associated with diastolic BP in normal weight children (ß = -0.012 ± 0.004, p = 0.006) but positively associated in obese children (ß = 2.178 ± 0.71, p = 0.002). A significant interaction between rs7556897T > C and the obesity status (obese or normal weight) was detected (ß = 3.49, p = 9.79 × 10-5) for BP in a combined population analysis. CCL20 mRNA was only expressed in the adipose tissue of overweight children, and its expression levels were 10.7× higher in PBMCs of overweight children than normal weight children. Finally, CCL20 mRNA levels were positively associated with rs7556897T > C in PBMCs of 58 normal weight children (ß = 0.43, p = 0.002). SLC19A3 was not expressed in PBMCs, and in adipose tissue, it showed same levels of expression in normal weight and overweight children. The gene expression results may highlight a specific involvement of CCL20 via communicating obesity/inflammation pathways that regulate BP. Conclusions Childhood obesity reverses the effect of rs7556897T > C on diastolic BP, possibly via the modulation of CCL20 expression levels.
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Presión Sanguínea/genética , Quimiocina CCL20/genética , Proteínas de Transporte de Membrana/genética , Obesidad/genética , Tejido Adiposo/metabolismo , Adolescente , Quimiocina CCL20/metabolismo , Niño , ADN Intergénico , Femenino , Francia , Expresión Génica , Humanos , Leucocitos Mononucleares/metabolismo , Masculino , Polimorfismo de Nucleótido Simple , Población BlancaRESUMEN
Many solid cancers are hierarchically organized with a small number of cancer stem cells (CSCs) able to regrow a tumor, while their progeny lacks this feature. Breast CSC is known to contribute to therapy resistance. The study of those cells is usually based on their cell-surface markers like CD44high /CD24low/neg or their aldehyde dehydrogenase (ALDH) activity. However, these markers cannot be used to track the dynamics of CSC. Here, a transcriptomic analysis is performed to identify segregating gene expression in CSCs and non-CSCs, sorted by Aldefluor assay. It is observed that among ALDH-associated genes, only ALDH1A1 isoform is increased in CSCs. A CSC reporter system is then developed by using a far red-fluorescent protein (mNeptune) under the control of ALDH1A1 promoter. mNeptune-positive cells exhibit higher sphere-forming capacity, tumor formation, and increased resistance to anticancer therapies. These results indicate that the reporter identifies cells with stemness characteristics. Moreover, live tracking of cells in a microfluidic system reveals a higher extravasation potential of CSCs. Live tracking of non-CSCs under irradiation treatment show, for the first time, live reprogramming of non-CSCs into CSCs. Therefore, the reporter will allow for cell tracking to better understand the implication of CSCs in breast cancer development and recurrence.
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Familia de Aldehído Deshidrogenasa 1/genética , Neoplasias de la Mama/genética , Rastreo Celular , Perfilación de la Expresión Génica , Genes Reporteros , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Retinal-Deshidrogenasa/genética , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Línea Celular Tumoral , Reprogramación Celular/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Genoma Humano , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Ratones Endogámicos NOD , Ratones SCID , Células Madre Neoplásicas/efectos de los fármacos , Regiones Promotoras Genéticas/genética , Reproducibilidad de los ResultadosRESUMEN
PURPOSE OF REVIEW: Non-autoimmune monogenic diabetes (MD) in young people shows a broad spectrum of clinical presentations, which is largely explained by multiple genetic etiologies. This review discusses how the application of state-of-the-art genomics research to precision diagnosis of MD, particularly the various subtypes of maturity-onset diabetes of the young (MODY), has increasingly informed diabetes precision medicine and patient care throughout life. RECENT FINDINGS: Due to extended genetic and clinical heterogeneity of MODY, diagnosis approaches based on next-generation sequencing have been worthwhile to better ascribe a specific subtype to each patient with young-onset diabetes. This guides the best appropriate treatment and clinical follow-up. Early etiological diagnosis of MD and individualized treatment are essential for achieving metabolic targets and avoiding long-term diabetes complications, as well as for drastically decreasing the financial and societal burden of diabetes-related healthcare. Genomic medicine-based practices help to optimize long-term clinical follow-up and patient care management.
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Diabetes Mellitus Tipo 2/genética , Adolescente , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación , Medicina de Precisión/métodosRESUMEN
[This corrects the article DOI: 10.1371/journal.pgen.1005378.].