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1.
Diabetes Metab Res Rev ; 40(5): e3833, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38961656

RESUMEN

AIMS: Heterogeneity in the rate of ß-cell loss in newly diagnosed type 1 diabetes patients is poorly understood and creates a barrier to designing and interpreting disease-modifying clinical trials. Integrative analyses of baseline multi-omics data obtained after the diagnosis of type 1 diabetes may provide mechanistic insight into the diverse rates of disease progression after type 1 diabetes diagnosis. METHODS: We collected samples in a pan-European consortium that enabled the concerted analysis of five different omics modalities in data from 97 newly diagnosed patients. In this study, we used Multi-Omics Factor Analysis to identify molecular signatures correlating with post-diagnosis decline in ß-cell mass measured as fasting C-peptide. RESULTS: Two molecular signatures were significantly correlated with fasting C-peptide levels. One signature showed a correlation to neutrophil degranulation, cytokine signalling, lymphoid and non-lymphoid cell interactions and G-protein coupled receptor signalling events that were inversely associated with a rapid decline in ß-cell function. The second signature was related to translation and viral infection was inversely associated with change in ß-cell function. In addition, the immunomics data revealed a Natural Killer cell signature associated with rapid ß-cell decline. CONCLUSIONS: Features that differ between individuals with slow and rapid decline in ß-cell mass could be valuable in staging and prediction of the rate of disease progression and thus enable smarter (shorter and smaller) trial designs for disease modifying therapies as well as offering biomarkers of therapeutic effect.


Asunto(s)
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Humanos , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/patología , Células Secretoras de Insulina/patología , Células Secretoras de Insulina/metabolismo , Femenino , Masculino , Adulto , Progresión de la Enfermedad , Biomarcadores/análisis , Estudios de Seguimiento , Adolescente , Adulto Joven , Pronóstico , Proteómica , Péptido C/análisis , Péptido C/sangre , Niño , Persona de Mediana Edad , Genómica , Multiómica
2.
Diabetologia ; 66(11): 1983-1996, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37537394

RESUMEN

AIMS/HYPOTHESIS: There is a growing need for markers that could help indicate the decline in beta cell function and recognise the need and efficacy of intervention in type 1 diabetes. Measurements of suitably selected serum markers could potentially provide a non-invasive and easily applicable solution to this challenge. Accordingly, we evaluated a broad panel of proteins previously associated with type 1 diabetes in serum from newly diagnosed individuals during the first year from diagnosis. To uncover associations with beta cell function, comparisons were made between these targeted proteomics measurements and changes in fasting C-peptide levels. To further distinguish proteins linked with the disease status, comparisons were made with measurements of the protein targets in age- and sex-matched autoantibody-negative unaffected family members (UFMs). METHODS: Selected reaction monitoring (SRM) mass spectrometry analyses of serum, targeting 85 type 1 diabetes-associated proteins, were made. Sera from individuals diagnosed under 18 years (n=86) were drawn within 6 weeks of diagnosis and at 3, 6 and 12 months afterwards (288 samples in total). The SRM data were compared with fasting C-peptide/glucose data, which was interpreted as a measure of beta cell function. The protein data were further compared with cross-sectional SRM measurements from UFMs (n=194). RESULTS: Eleven proteins had statistically significant associations with fasting C-peptide/glucose. Of these, apolipoprotein L1 and glutathione peroxidase 3 (GPX3) displayed the strongest positive and inverse associations, respectively. Changes in GPX3 levels during the first year after diagnosis indicated future fasting C-peptide/glucose levels. In addition, differences in the levels of 13 proteins were observed between the individuals with type 1 diabetes and the matched UFMs. These included GPX3, transthyretin, prothrombin, apolipoprotein C1 and members of the IGF family. CONCLUSIONS/INTERPRETATION: The association of several targeted proteins with fasting C-peptide/glucose levels in the first year after diagnosis suggests their connection with the underlying changes accompanying alterations in beta cell function in type 1 diabetes. Moreover, the direction of change in GPX3 during the first year was indicative of subsequent fasting C-peptide/glucose levels, and supports further investigation of this and other serum protein measurements in future studies of beta cell function in type 1 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Humanos , Adolescente , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 2/metabolismo , Péptido C , Proteómica , Estudios Transversales , Ayuno , Glucosa , Insulina/metabolismo , Glucemia/metabolismo
3.
EBioMedicine ; 92: 104625, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37224769

RESUMEN

BACKGROUND: Type 1 diabetes is a complex heterogenous autoimmune disease without therapeutic interventions available to prevent or reverse the disease. This study aimed to identify transcriptional changes associated with the disease progression in patients with recent-onset type 1 diabetes. METHODS: Whole-blood samples were collected as part of the INNODIA study at baseline and 12 months after diagnosis of type 1 diabetes. We used linear mixed-effects modelling on RNA-seq data to identify genes associated with age, sex, or disease progression. Cell-type proportions were estimated from the RNA-seq data using computational deconvolution. Associations to clinical variables were estimated using Pearson's or point-biserial correlation for continuous and dichotomous variables, respectively, using only complete pairs of observations. FINDINGS: We found that genes and pathways related to innate immunity were downregulated during the first year after diagnosis. Significant associations of the gene expression changes were found with ZnT8A autoantibody positivity. Rate of change in the expression of 16 genes between baseline and 12 months was found to predict the decline in C-peptide at 24 months. Interestingly and consistent with earlier reports, increased B cell levels and decreased neutrophil levels were associated with the rapid progression. INTERPRETATION: There is considerable individual variation in the rate of progression from appearance of type 1 diabetes-specific autoantibodies to clinical disease. Patient stratification and prediction of disease progression can help in developing more personalised therapeutic strategies for different disease endotypes. FUNDING: A full list of funding bodies can be found under Acknowledgments.


Asunto(s)
Enfermedades Autoinmunes , Diabetes Mellitus Tipo 1 , Humanos , Transcriptoma , Progresión de la Enfermedad , Autoanticuerpos
4.
Trials ; 23(1): 414, 2022 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-35585600

RESUMEN

BACKGROUND: The INNODIA consortium has established a pan-European infrastructure using validated centres to prospectively evaluate clinical data from individuals with newly diagnosed type 1 diabetes combined with centralised collection of clinical samples to determine rates of decline in beta-cell function and identify novel biomarkers, which could be used for future stratification of phase 2 clinical trials. METHODS: In this context, we have developed a Master Protocol, based on the "backbone" of the INNODIA natural history study, which we believe could improve the delivery of phase 2 studies exploring the use of single or combinations of Investigational Medicinal Products (IMPs), designed to prevent or reverse declines in beta-cell function in individuals with newly diagnosed type 1 diabetes. Although many IMPs have demonstrated potential efficacy in phase 2 studies, few subsequent phase 3 studies have confirmed these benefits. Currently, phase 2 drug development for this indication is limited by poor evaluation of drug dosage and lack of mechanistic data to understand variable responses to the IMPs. Identification of biomarkers which might permit more robust stratification of participants at baseline has been slow. DISCUSSION: The Master Protocol provides (1) standardised assessment of efficacy and safety, (2) comparable collection of mechanistic data, (3) the opportunity to include adaptive designs and the use of shared control groups in the evaluation of combination therapies, and (4) benefits of greater understanding of endpoint variation to ensure more robust sample size calculations and future baseline stratification using existing and novel biomarkers.


Asunto(s)
COVID-19 , Diabetes Mellitus Tipo 1 , Adolescente , Adulto , Biomarcadores , Niño , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Humanos , SARS-CoV-2 , Resultado del Tratamiento
5.
BMJ Open ; 11(12): e053669, 2021 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-34876434

RESUMEN

INTRODUCTION: Type 1 diabetes (T1D) is a chronic autoimmune disease, characterised by progressive destruction of the insulin-producing ß cells of the pancreas. One immunosuppressive agent that has recently shown promise in the treatment of new-onset T1D subjects aged 12-45 years is antithymocyte globulin (ATG), Thymoglobuline, encouraging further exploration in lower age groups. METHODS AND ANALYSIS: Minimal effective low dose (MELD)-ATG is a phase 2, multicentre, randomised, double-blind, placebo-controlled, multiarm parallel-group trial in participants 5-25 years diagnosed with T1D within 3-9 weeks of planned treatment day 1. A total of 114 participants will be recruited sequentially into seven different cohorts with the first cohort of 30 participants being randomised to placebo, 2.5 mg/kg, 1.5 mg/kg, 0.5 mg/kg and 0.1 mg/kg ATG total dose in a 1:1:1:1:1 allocation ratio. The next six cohorts of 12-15 participants will be randomised to placebo, 2.5 mg/kg, and one or two selected middle ATG total doses in a 1:1:1:1 or 1:1:1 allocation ratio, as dependent on the number of middle doses, given intravenously over two consecutive days. The primary objective will be to determine the changes in stimulated C-peptide response over the first 2 hours of a mixed meal tolerance test at 12 months for 2.5 mg/kg ATG arm vs the placebo. Conditional on finding a significant difference at 2.5 mg/kg, a minimally effective dose will be sought. Secondary objectives include the determination of the effects of a particular ATG treatment dose on (1) stimulated C-peptide, (2) glycated haemoglobin, (3) daily insulin dose, (4) time in range by intermittent continuous glucose monitoring measures, (5) fasting and stimulated dry blood spot (DBS) C-peptide measurements. ETHICS AND DISSEMINATION: MELD-ATG received first regulatory and ethical approvals in Belgium in September 2020 and from the German and UK regulators as of February 2021. The publication policy is set in the INNODIA (An innovative approach towards understanding and arresting Type 1 diabetes consortium) grant agreement (www.innodia.eu). TRIAL REGISTRATION NUMBER: NCT03936634; Pre-results.


Asunto(s)
Diabetes Mellitus Tipo 1 , Adolescente , Adulto , Suero Antilinfocítico/uso terapéutico , Glucemia , Automonitorización de la Glucosa Sanguínea , Niño , Ensayos Clínicos Fase II como Asunto , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Humanos , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Timocitos , Resultado del Tratamiento , Adulto Joven
6.
Nat Metab ; 3(7): 1017-1031, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34183850

RESUMEN

Most research on human pancreatic islets is conducted on samples obtained from normoglycaemic or diseased brain-dead donors and thus cannot accurately describe the molecular changes of pancreatic islet beta cells as they progress towards a state of deficient insulin secretion in type 2 diabetes (T2D). Here, we conduct a comprehensive multi-omics analysis of pancreatic islets obtained from metabolically profiled pancreatectomized living human donors stratified along the glycemic continuum, from normoglycemia to T2D. We find that islet pools isolated from surgical samples by laser-capture microdissection display remarkably more heterogeneous transcriptomic and proteomic profiles in patients with diabetes than in non-diabetic controls. The differential regulation of islet gene expression is already observed in prediabetic individuals with impaired glucose tolerance. Our findings demonstrate a progressive, but disharmonic, remodelling of mature beta cells, challenging current hypotheses of linear trajectories toward precursor or transdifferentiation stages in T2D. Furthermore, through integration of islet transcriptomics with preoperative blood plasma lipidomics, we define the relative importance of gene coexpression modules and lipids that are positively or negatively associated with HbA1c levels, pointing to potential prognostic markers.


Asunto(s)
Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Biomarcadores , Glucemia , Susceptibilidad a Enfermedades , Metabolismo Energético , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Insulina/metabolismo , Donadores Vivos , Metabolómica , Proteómica
8.
Cell Rep ; 34(5): 108703, 2021 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-33535042

RESUMEN

Using chromatin conformation capture, we show that an enhancer cluster in the STARD10 type 2 diabetes (T2D) locus forms a defined 3-dimensional (3D) chromatin domain. A 4.1-kb region within this locus, carrying 5 T2D-associated variants, physically interacts with CTCF-binding regions and with an enhancer possessing strong transcriptional activity. Analysis of human islet 3D chromatin interaction maps identifies the FCHSD2 gene as an additional target of the enhancer cluster. CRISPR-Cas9-mediated deletion of the variant region, or of the associated enhancer, from human pancreas-derived EndoC-ßH1 cells impairs glucose-stimulated insulin secretion. Expression of both STARD10 and FCHSD2 is reduced in cells harboring CRISPR deletions, and lower expression of STARD10 and FCHSD2 is associated, the latter nominally, with the possession of risk variant alleles in human islets. Finally, CRISPR-Cas9-mediated loss of STARD10 or FCHSD2, but not ARAP1, impairs regulated insulin secretion. Thus, multiple genes at the STARD10 locus influence ß cell function.


Asunto(s)
Proteínas Portadoras/metabolismo , Cromatina/metabolismo , Células Secretoras de Insulina/metabolismo , Proteínas de la Membrana/metabolismo , Fosfoproteínas/metabolismo , Humanos
9.
Cell Rep ; 33(9): 108466, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33264613

RESUMEN

Pancreatic ß cell failure is key to type 2 diabetes (T2D) onset and progression. Here, we assess whether human ß cell dysfunction induced by metabolic stress is reversible, evaluate the molecular pathways underlying persistent or transient damage, and explore the relationships with T2D islet traits. Twenty-six islet preparations are exposed to several lipotoxic/glucotoxic conditions, some of which impair insulin release, depending on stressor type, concentration, and combination. The reversal of dysfunction occurs after washout for some, although not all, of the lipoglucotoxic insults. Islet transcriptomes assessed by RNA sequencing and expression quantitative trait loci (eQTL) analysis identify specific pathways underlying ß cell failure and recovery. Comparison of a large number of human T2D islet transcriptomes with those of persistent or reversible ß cell lipoglucotoxicity show shared gene expression signatures. The identification of mechanisms associated with human ß cell dysfunction and recovery and their overlap with T2D islet traits provide insights into T2D pathogenesis, fostering the development of improved ß cell-targeted therapeutic strategies.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Expresión Génica/genética , Células Secretoras de Insulina/metabolismo , Estrés Fisiológico/genética , Diabetes Mellitus Tipo 2/patología , Humanos
10.
Mol Metab ; 27S: S1-S6, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31500820

RESUMEN

BACKGROUND: The availability of human pancreatic islets with characteristics closely resembling those present in vivo is instrumental for ex vivo studies in diabetes research. SCOPE OF REVIEW: In this review we propose metabolically phenotyped surgical patients as a novel source of pancreatic tissue for islet research. Laser Capture Microdissection from snap frozen surgical specimens is a relatively simple, reproducible and scalable method to isolate islets of highest purity for many types of "omics" analyses. Fresh pancreatic tissue slices enable the functional characterization of living islet cells in situ through dynamic experiments. Access to complete medical history and laboratory values for each donor offers the opportunity of direct correlations with different "omics" data and detailed metabolic profiling prior to pancreas surgery. Peripheral blood samples complete the picture of each patient and represent a platform for pursuit of biomarkers with uniquely comprehensive background information in regard to the donor's islet cells. MAJOR CONCLUSIONS: Living donors provide the scientific community with a steady and abundant supply of excellent material to study islets closest to their in situ environment, thus advancing our understanding of their physiology in health and diseases.


Asunto(s)
Diabetes Mellitus/metabolismo , Diabetes Mellitus/cirugía , Células Secretoras de Insulina/metabolismo , Pancreatectomía , Humanos , Donadores Vivos , Fenotipo
12.
Mol Metab ; 24: 98-107, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30956117

RESUMEN

OBJECTIVE: Genome wide association studies (GWAS) for type 2 diabetes (T2D) have identified genetic loci that often localise in non-coding regions of the genome, suggesting gene regulation effects. We combined genetic and transcriptomic analysis from human islets obtained from brain-dead organ donors or surgical patients to detect expression quantitative trait loci (eQTLs) and shed light into the regulatory mechanisms of these genes. METHODS: Pancreatic islets were isolated either by laser capture microdissection (LCM) from surgical specimens of 103 metabolically phenotyped pancreatectomized patients (PPP) or by collagenase digestion of pancreas from 100 brain-dead organ donors (OD). Genotyping (> 8.7 million single nucleotide polymorphisms) and expression (> 47,000 transcripts and splice variants) analyses were combined to generate cis-eQTLs. RESULTS: After applying genome-wide false discovery rate significance thresholds, we identified 1,173 and 1,021 eQTLs in samples of OD and PPP, respectively. Among the strongest eQTLs shared between OD and PPP were CHURC1 (OD p-value=1.71 × 10-24; PPP p-value = 3.64 × 10-24) and PSPH (OD p-value = 3.92 × 10-26; PPP p-value = 3.64 × 10-24). We identified eQTLs in linkage-disequilibrium with GWAS loci T2D and associated traits, including TTLL6, MLX and KIF9 loci, which do not implicate the nearest gene. We found in the PPP datasets 11 eQTL genes, which were differentially expressed in T2D and two genes (CYP4V2 and TSEN2) associated with HbA1c but none in the OD samples. CONCLUSIONS: eQTL analysis of LCM islets from PPP led us to identify novel genes which had not been previously linked to islet biology and T2D. The understanding gained from eQTL approaches, especially using surgical samples of living patients, provides a more accurate 3-dimensional representation than those from genetic studies alone.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Islotes Pancreáticos/metabolismo , Sitios de Carácter Cuantitativo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Familia 4 del Citocromo P450/genética , Diabetes Mellitus Tipo 2/patología , Humanos , Cinesinas/genética , Captura por Microdisección con Láser , Proteínas de la Membrana/genética , Péptido Sintasas/genética , Polimorfismo de Nucleótido Simple
13.
J Clin Endocrinol Metab ; 103(12): 4373-4383, 2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-30202879

RESUMEN

Context: Reduced ß-cell mass, impaired islet function, and dedifferentiation are considered causal to development of hyperglycemia and type 2 diabetes. In human cohort studies, changes of islet cell-specific expression patterns have been associated with diabetes but not directly with in vivo insulin secretion. Objective: This study investigates alterations of islet gene expression and corresponding gene variants in the context of in vivo glycemic traits from the same patients. Methods: Fasting blood was collected before surgery, and pancreatic tissue was frozen after resection from 18 patients undergoing pancreatectomy. Islet tissue was isolated by laser capture microdissection. Islet transcriptome was analyzed using microarray and quantitative RT-PCR. Proteins were examined by immunohistochemistry and western blotting. The association of gene variants with insulin secretion was investigated with oral glucose tolerance test (OGTT)-derived insulin secretion measured in a large cohort of subjects at increased risk of type 2 diabetes and with hyperglycemic clamp in a subset. Results: Differential gene expression between islets from normoglycemic and hyperglycemic patients was prominent for the glycolytic enzyme ALDOB and the obesity-associated gene FAIM2. The mRNA levels of both genes correlated negatively with insulin secretion and positively with HbA1c. Islets of hyperglycemic patients displayed increased ALDOB immunoreactivity in insulin-positive cells, whereas α- and δ-cells were negative. Exposure of isolated islets to hyperglycemia augmented ALDOB expression. The minor allele of the ALDOB variant rs550915 associated with significantly higher levels of C-peptide and insulin during OGTT and hyperglycemic clamp, respectively. Conclusion: Our analyses suggest that increased ALDOB expression in human islets is associated with lower insulin secretion.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Fructosa-Bifosfato Aldolasa/metabolismo , Hiperglucemia/metabolismo , Secreción de Insulina/fisiología , Islotes Pancreáticos/metabolismo , Glucemia , Células Cultivadas , Estudios Transversales , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/genética , Fructosa-Bifosfato Aldolasa/genética , Perfilación de la Expresión Génica , Técnica de Clampeo de la Glucosa , Prueba de Tolerancia a la Glucosa , Hemoglobina Glucada/análisis , Voluntarios Sanos , Humanos , Hiperglucemia/sangre , Hiperglucemia/genética , Insulina/sangre , Captura por Microdisección con Láser , Pancreatectomía , Neoplasias Pancreáticas/cirugía , Polimorfismo de Nucleótido Simple , Cultivo Primario de Células
14.
Diabetologia ; 61(3): 641-657, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29185012

RESUMEN

AIMS/HYPOTHESIS: Pancreatic islet beta cell failure causes type 2 diabetes in humans. To identify transcriptomic changes in type 2 diabetic islets, the Innovative Medicines Initiative for Diabetes: Improving beta-cell function and identification of diagnostic biomarkers for treatment monitoring in Diabetes (IMIDIA) consortium ( www.imidia.org ) established a comprehensive, unique multicentre biobank of human islets and pancreas tissues from organ donors and metabolically phenotyped pancreatectomised patients (PPP). METHODS: Affymetrix microarrays were used to assess the islet transcriptome of islets isolated either by enzymatic digestion from 103 organ donors (OD), including 84 non-diabetic and 19 type 2 diabetic individuals, or by laser capture microdissection (LCM) from surgical specimens of 103 PPP, including 32 non-diabetic, 36 with type 2 diabetes, 15 with impaired glucose tolerance (IGT) and 20 with recent-onset diabetes (<1 year), conceivably secondary to the pancreatic disorder leading to surgery (type 3c diabetes). Bioinformatics tools were used to (1) compare the islet transcriptome of type 2 diabetic vs non-diabetic OD and PPP as well as vs IGT and type 3c diabetes within the PPP group; and (2) identify transcription factors driving gene co-expression modules correlated with insulin secretion ex vivo and glucose tolerance in vivo. Selected genes of interest were validated for their expression and function in beta cells. RESULTS: Comparative transcriptomic analysis identified 19 genes differentially expressed (false discovery rate ≤0.05, fold change ≥1.5) in type 2 diabetic vs non-diabetic islets from OD and PPP. Nine out of these 19 dysregulated genes were not previously reported to be dysregulated in type 2 diabetic islets. Signature genes included TMEM37, which inhibited Ca2+-influx and insulin secretion in beta cells, and ARG2 and PPP1R1A, which promoted insulin secretion. Systems biology approaches identified HNF1A, PDX1 and REST as drivers of gene co-expression modules correlated with impaired insulin secretion or glucose tolerance, and 14 out of 19 differentially expressed type 2 diabetic islet signature genes were enriched in these modules. None of these signature genes was significantly dysregulated in islets of PPP with impaired glucose tolerance or type 3c diabetes. CONCLUSIONS/INTERPRETATION: These studies enabled the stringent definition of a novel transcriptomic signature of type 2 diabetic islets, regardless of islet source and isolation procedure. Lack of this signature in islets from PPP with IGT or type 3c diabetes indicates differences possibly due to peculiarities of these hyperglycaemic conditions and/or a role for duration and severity of hyperglycaemia. Alternatively, these transcriptomic changes capture, but may not precede, beta cell failure.


Asunto(s)
Bancos de Muestras Biológicas , Diabetes Mellitus Tipo 2/metabolismo , Biología de Sistemas/métodos , Donantes de Tejidos , Transcriptoma/genética , Anciano , Anciano de 80 o más Años , Biología Computacional , Femenino , Humanos , Masculino , Pancreatectomía
15.
Cell Rep ; 18(9): 2269-2279, 2017 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-28249170

RESUMEN

Plasma metabolite concentrations reflect the activity of tissue metabolic pathways and their quantitative determination may be informative about pathogenic conditions. We searched for plasma lipid species whose concentrations correlate with various parameters of glucose homeostasis and susceptibility to type 2 diabetes (T2D). Shotgun lipidomic analysis of the plasma of mice from different genetic backgrounds, which develop a pre-diabetic state at different rates when metabolically stressed, led to the identification of a group of sphingolipids correlated with glucose tolerance and insulin secretion. Quantitative analysis of these and closely related lipids in the plasma of individuals from two population-based prospective cohorts revealed that specific long-chain fatty-acid-containing dihydroceramides were significantly elevated in the plasma of individuals who will progress to diabetes up to 9 years before disease onset. These lipids may serve as early biomarkers of, and help identify, metabolic deregulation in the pathogenesis of T2D.


Asunto(s)
Biomarcadores/sangre , Ceramidas/sangre , Diabetes Mellitus Tipo 2/sangre , Susceptibilidad a Enfermedades/sangre , Adulto , Anciano , Animales , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Intolerancia a la Glucosa/sangre , Intolerancia a la Glucosa/metabolismo , Prueba de Tolerancia a la Glucosa/métodos , Humanos , Insulina/sangre , Resistencia a la Insulina/fisiología , Lípidos/sangre , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Persona de Mediana Edad , Estudios Prospectivos , Esfingolípidos/sangre
17.
Am J Hum Genet ; 100(2): 238-256, 2017 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-28132686

RESUMEN

Genetic variants near ARAP1 (CENTD2) and STARD10 influence type 2 diabetes (T2D) risk. The risk alleles impair glucose-induced insulin secretion and, paradoxically but characteristically, are associated with decreased proinsulin:insulin ratios, indicating improved proinsulin conversion. Neither the identity of the causal variants nor the gene(s) through which risk is conferred have been firmly established. Whereas ARAP1 encodes a GTPase activating protein, STARD10 is a member of the steroidogenic acute regulatory protein (StAR)-related lipid transfer protein family. By integrating genetic fine-mapping and epigenomic annotation data and performing promoter-reporter and chromatin conformational capture (3C) studies in ß cell lines, we localize the causal variant(s) at this locus to a 5 kb region that overlaps a stretch-enhancer active in islets. This region contains several highly correlated T2D-risk variants, including the rs140130268 indel. Expression QTL analysis of islet transcriptomes from three independent subject groups demonstrated that T2D-risk allele carriers displayed reduced levels of STARD10 mRNA, with no concomitant change in ARAP1 mRNA levels. Correspondingly, ß-cell-selective deletion of StarD10 in mice led to impaired glucose-stimulated Ca2+ dynamics and insulin secretion and recapitulated the pattern of improved proinsulin processing observed at the human GWAS signal. Conversely, overexpression of StarD10 in the adult ß cell improved glucose tolerance in high fat-fed animals. In contrast, manipulation of Arap1 in ß cells had no impact on insulin secretion or proinsulin conversion in mice. This convergence of human and murine data provides compelling evidence that the T2D risk associated with variation at this locus is mediated through reduction in STARD10 expression in the ß cell.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Insulina/metabolismo , Fosfoproteínas/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Alelos , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Clonación Molecular , Diabetes Mellitus Tipo 2/sangre , Proteínas Activadoras de GTPasa/genética , Proteínas Activadoras de GTPasa/metabolismo , Regulación de la Expresión Génica , Variación Genética , Homeostasis , Humanos , Insulina/sangre , Secreción de Insulina , Células Secretoras de Insulina/metabolismo , Hígado/metabolismo , Ratones , Proinsulina/sangre , Proinsulina/metabolismo , Sitios de Carácter Cuantitativo , Transcriptoma
18.
Nat Commun ; 7: 13250, 2016 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-27841257

RESUMEN

Insulin-secreting beta cells play an essential role in maintaining physiological blood glucose levels, and their dysfunction leads to the development of diabetes. To elucidate the signalling events regulating insulin secretion, we applied a recently developed phosphoproteomics workflow. We quantified the time-resolved phosphoproteome of murine pancreatic cells following their exposure to glucose and in combination with small molecule compounds that promote insulin secretion. The quantitative phosphoproteome of 30,000 sites clustered into three main groups in concordance with the modulation of the three key kinases: PKA, PKC and CK2A. A high-resolution time course revealed key novel regulatory sites, revealing the importance of methyltransferase DNMT3A phosphorylation in the glucose response. Remarkably a significant proportion of these novel regulatory sites is significantly downregulated in diabetic islets. Control of insulin secretion is embedded in an unexpectedly broad and complex range of cellular functions, which are perturbed by drugs in multiple ways.


Asunto(s)
Glucosa/farmacología , Células Secretoras de Insulina/efectos de los fármacos , Insulina/metabolismo , Fosfoproteínas/metabolismo , Proteoma/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Línea Celular Tumoral , Análisis por Conglomerados , Diabetes Mellitus Tipo 1/metabolismo , Secreción de Insulina , Células Secretoras de Insulina/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Fosfoproteínas/clasificación , Fosforilación/efectos de los fármacos , Proteómica/métodos
19.
Biomaterials ; 75: 1-12, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26474038

RESUMEN

The monitoring of diabetes mellitus, as it develops and becomes clinically evident, remains a major challenge for diagnostic imaging in clinical practice. Here we present a novel approach to beta-cell imaging by targeting the sulphonylurea receptor subtype 1 (SUR1), using multivalent derivatives of the anti-diabetic drug glibenclamide. Since glibenclamide has a high affinity for SUR1 but does not contain a suitable functional group to be linked to an imaging probe, we have synthesized 11 glibenclamide derivatives and evaluated their affinity to SUR1 in MIN6 cells. The most promising compound has been used to obtain multivalent glibenclamide-polyamidoamine (PAMAM) derivatives, containing up to 15 sulphonylurea moieties per dendrimer. The remaining functional groups on the dendrimers can consecutively be used for labeling with reporter groups for different imaging modalities, thus allowing for multifunctional imaging, and for the modification of pharmacokinetic properties. We synthesized fluorochrome-labeled multivalent probes, that demonstrate in cellular assays affinities to SUR1 in the nanomolar range, superior to native glibenclamide. The probes specifically label MIN6 cells, but not HeLa or PANC-1 cells which do not express SUR1. A very low cytotoxicity of the multivalent probes is demonstrated by the persistent release of insulin from MIN6 cells exposed to high glucose concentrations. Furthermore, the probes display positive labeling of beta-cells of primary mouse and human islet-cells ex vivo and of islets of Langerhans in vivo. The data document that multivalent probes based on glibenclamide derivatives provide a suitable platform for further developments of cell-specific probes, and can be adapted for multiple imaging modalities, including those that are now used in the clinics.


Asunto(s)
Diagnóstico por Imagen , Gliburida/farmacología , Islotes Pancreáticos/metabolismo , Sondas Moleculares/química , Animales , Muerte Celular/efectos de los fármacos , Dendrímeros/química , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/química , Gliburida/síntesis química , Gliburida/química , Células HeLa , Humanos , Islotes Pancreáticos/efectos de los fármacos , Ligandos , Ratones , Microscopía Confocal , Especificidad de Órganos/efectos de los fármacos , Receptores de Sulfonilureas/metabolismo
20.
World J Cardiol ; 7(1): 31-42, 2015 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-25632317

RESUMEN

AIM: To compare the therapeutic efficacy of SAR407899 with the current standard treatment for hypertension [an angiotensin converting enzyme (ACE)-inhibitor and a calcium channel blocker] and compare the frequency and severity of the hypertension-related end-organ damage. METHODS: Long-term pharmacological characte-rization of SAR407899 has been performed in two animal models of hypertension, of which one is sensitive to ACE-inhibition (LNAME) and the other is insensitive [deoxycorticosterone acetate (DOCA)]. SAR407899 efficiently lowered high blood pressure and significantly reduced late-stage end organ damage as indicated by improved heart, kidney and endothelial function and reduced heart and kidney fibrosis in both models of chronic hypertension. RESULTS: Long term treatment with SAR407899 has been well tolerated and dose-dependently reduced elevated blood pressure in both models with no signs of tachyphylaxia. Blood pressure lowering effects and protective effects on hypertension related end organ damage of SAR407899 were superior to ramipril and amlodipine in the DOCA rat. Typical end-organ damage was significantly reduced in the SAR407899-treated animals. Chronic administration of SAR407899 significantly reduced albuminuria in both models. The beneficial effect of SAR407899 was associated with a reduction in leukocyte/macrophage tissue infiltration. The overall protective effect of SAR407899 was superior or comparable to that of ACE-inhibition or calcium channel blockade. Chronic application of SAR407899 protects against hypertension and hypertension-induced end organ damage, regardless of the pathophysiological mechanism of hypertension. CONCLUSION: Rho-kinases-inhibition by the SAR407899 represents a new therapeutic option for the treatment of hypertension and its complications.

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