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1.
Diabetologia ; 67(2): 333-345, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37897566

RESUMEN

AIMS/HYPOTHESIS: We aimed to investigate the association between the abundance of Dysosmobacter welbionis, a commensal gut bacterium, and metabolic health in human participants with obesity and diabetes, and the influence of metformin treatment and prebiotic intervention. METHODS: Metabolic variables were assessed and faecal samples were collected from 106 participants in a randomised controlled intervention with a prebiotic stratified by metformin treatment (Food4Gut trial). The abundance of D. welbionis was measured by quantitative PCR and correlated with metabolic markers. The in vitro effect of metformin on D. welbionis growth was evaluated and an in vivo study was performed in mice to investigate the effects of metformin and D. welbionis J115T supplementation, either alone or in combination, on metabolic variables. RESULTS: D. welbionis abundance was unaffected by prebiotic treatment but was significantly higher in metformin-treated participants. Responders to prebiotic treatment had higher baseline D. welbionis levels than non-responders. D. welbionis was negatively correlated with aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and fasting blood glucose levels in humans with obesity and type 2 diabetes. In vitro, metformin had no direct effect on D. welbionis growth. In mice, D. welbionis J115T treatment reduced body weight gain and liver weight, and improved glucose tolerance to a better level than metformin, but did not have synergistic effects with metformin. CONCLUSIONS/INTERPRETATION: D. welbionis abundance is influenced by metformin treatment and associated with prebiotic response, liver health and glucose metabolism in humans with obesity and diabetes. This study suggests that D. welbionis may play a role in metabolic health and warrants further investigation. CLINICAL TRIAL: NCT03852069.


Asunto(s)
Clostridiales , Diabetes Mellitus Tipo 2 , Metformina , Humanos , Animales , Ratones , Metformina/uso terapéutico , Metformina/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Dieta Alta en Grasa
2.
Diabetologia ; 66(8): 1544-1556, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36988639

RESUMEN

AIMS/HYPOTHESIS: TNF-α plays a role in pancreatic beta cell loss in type 1 diabetes mellitus. In clinical interventions, TNF-α inhibition preserves C-peptide levels in early type 1 diabetes. In this study we evaluated the crosstalk of TNF-α, as compared with type I IFNs, with the type 1 diabetes candidate gene PTPN2 (encoding protein tyrosine phosphatase non-receptor type 2 [PTPN2]) in human beta cells. METHODS: EndoC-ßH1 cells, dispersed human pancreatic islets or induced pluripotent stem cell (iPSC)-derived islet-like cells were transfected with siRNAs targeting various genes (siCTRL, siPTPN2, siJNK1, siJNK3 or siBIM). Cells were treated for 48 h with IFN-α (2000 U/ml) or TNF-α (1000 U/ml). Cell death was evaluated using Hoechst 33342 and propidium iodide staining. mRNA levels were assessed by quantitative reverse transcription PCR (qRT-PCR) and protein expression by immunoblot. RESULTS: PTPN2 silencing sensitised beta cells to cytotoxicity induced by IFN-α and/or TNF-α by 20-50%, depending on the human cell model utilised; there was no potentiation between the cytokines. We silenced c-Jun N-terminal kinase (JNK)1 or Bcl-2-like protein 2 (BIM), and this abolished the proapoptotic effects of IFN-α, TNF-α or the combination of both after PTPN2 inhibition. We further observed that PTPN2 silencing increased TNF-α-induced JNK1 and BIM phosphorylation and that JNK3 is necessary for beta cell resistance to IFN-α cytotoxicity. CONCLUSIONS/INTERPRETATION: We show that the type 1 diabetes candidate gene PTPN2 is a key regulator of the deleterious effects of TNF-α in human beta cells. It is conceivable that people with type 1 diabetes carrying risk-associated PTPN2 polymorphisms may particularly benefit from therapies inhibiting TNF-α.


Asunto(s)
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Humanos , Factor de Necrosis Tumoral alfa/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/farmacología , Citocinas/metabolismo , Muerte Celular , Células Secretoras de Insulina/metabolismo , Interferón-alfa/farmacología
3.
Diabetologia ; 66(3): 450-460, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36401627

RESUMEN

AIMS/HYPOTHESIS: Diabetes is characterised by progressive loss of functional pancreatic beta cells. None of the therapeutic agents used to treat diabetes arrest this process; preventing beta cell loss remains a major unmet need. We have previously shown that serum from eight young healthy male participants who exercised for 8 weeks protected human islets and insulin-producing EndoC-ßH1 cells from apoptosis induced by proinflammatory cytokines or the endoplasmic reticulum (ER) stressor thapsigargin. Whether this protective effect is influenced by sex, age, training modality, ancestry or diabetes is unknown. METHODS: We enrolled 82 individuals, male or female, non-diabetic or diabetic, from different origins, in different supervised training protocols for 8-12 weeks (including training at home during the COVID-19 pandemic). EndoC-ßH1 cells were treated with 'exercised' serum or with the exerkine clusterin to ascertain cytoprotection from ER stress. RESULTS: The exercise interventions were effective and improved [Formula: see text] values in both younger and older, non-obese and obese, non-diabetic and diabetic participants. Serum obtained after training conferred significant beta cell protection (28% to 35% protection after 4 and 8 weeks of training, respectively) from severe ER stress-induced apoptosis. Cytoprotection was not affected by the type of exercise training or participant age, sex, BMI or ancestry, and persisted for up to 2 months after the end of the training programme. Serum from exercised participants with type 1 or type 2 diabetes was similarly protective. Clusterin reproduced the beneficial effects of exercised sera. CONCLUSIONS/INTERPRETATION: These data uncover the unexpected potential to preserve beta cell health by exercise training, opening a new avenue to prevent or slow diabetes progression through humoral muscle-beta cell crosstalk.


Asunto(s)
COVID-19 , Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Humanos , Masculino , Femenino , Lactante , Células Secretoras de Insulina/metabolismo , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/metabolismo , Clusterina/metabolismo , Clusterina/farmacología , Pandemias , Apoptosis/fisiología , Estrés del Retículo Endoplásmico
4.
Diabetologia ; 66(7): 1306-1321, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36995380

RESUMEN

AIMS/HYPOTHESIS: Wolfram syndrome is a rare autosomal recessive disorder caused by pathogenic variants in the WFS1 gene. It is characterised by insulin-dependent diabetes mellitus, optic nerve atrophy, diabetes insipidus, hearing loss and neurodegeneration. Considering the unmet treatment need for this orphan disease, this study aimed to evaluate the therapeutic potential of glucagon-like peptide 1 receptor (GLP-1R) agonists under wolframin (WFS1) deficiency with a particular focus on human beta cells and neurons. METHODS: The effect of the GLP-1R agonists dulaglutide and exenatide was examined in Wfs1 knockout mice and in an array of human preclinical models of Wolfram syndrome, including WFS1-deficient human beta cells, human induced pluripotent stem cell (iPSC)-derived beta-like cells and neurons from control individuals and individuals affected by Wolfram syndrome, and humanised mice. RESULTS: Our study shows that the long-lasting GLP-1R agonist dulaglutide reverses impaired glucose tolerance in WFS1-deficient mice, and that exenatide and dulaglutide improve beta cell function and prevent apoptosis in different human WFS1-deficient models including iPSC-derived beta cells from people with Wolfram syndrome. Exenatide improved mitochondrial function, reduced oxidative stress and prevented apoptosis in Wolfram syndrome iPSC-derived neural precursors and cerebellar neurons. CONCLUSIONS/INTERPRETATION: Our study provides novel evidence for the beneficial effect of GLP-1R agonists on WFS1-deficient human pancreatic beta cells and neurons, suggesting that these drugs may be considered as a treatment for individuals with Wolfram syndrome.


Asunto(s)
Células Madre Pluripotentes Inducidas , Células Secretoras de Insulina , Atrofia Óptica , Síndrome de Wolfram , Humanos , Animales , Ratones , Síndrome de Wolfram/tratamiento farmacológico , Síndrome de Wolfram/genética , Exenatida/uso terapéutico , Atrofia Óptica/patología , Células Secretoras de Insulina/patología , Ratones Noqueados
5.
J Biol Chem ; 296: 100661, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33862081

RESUMEN

Variable number of tandem repeat (VNTR) sequences in the genome can have functional consequences that contribute to human disease. This is the case for the CEL gene, which is specifically expressed in pancreatic acinar cells and encodes the digestive enzyme carboxyl ester lipase. Rare single-base deletions (DELs) within the first (DEL1) or fourth (DEL4) VNTR segment of CEL cause maturity-onset diabetes of the young, type 8 (MODY8), an inherited disorder characterized by exocrine pancreatic dysfunction and diabetes. Studies on the DEL1 variant have suggested that MODY8 is initiated by CEL protein misfolding and aggregation. However, it is unclear how the position of single-base deletions within the CEL VNTR affects pathogenic properties of the protein. Here, we investigated four naturally occurring CEL variants, arising from single-base deletions in different VNTR segments (DEL1, DEL4, DEL9, and DEL13). When the four variants were expressed in human embryonic kidney 293 cells, only DEL1 and DEL4 led to significantly reduced secretion, increased intracellular aggregation, and increased endoplasmic reticulum stress compared with normal CEL protein. The level of O-glycosylation was affected in all DEL variants. Moreover, all variants had enzymatic activity comparable with that of normal CEL. We conclude that the longest aberrant protein tails, resulting from single-base deletions in the proximal VNTR segments, have highest pathogenic potential, explaining why DEL1 and DEL4 but not DEL9 and DEL13 have been observed in patients with MODY8. These findings further support the view that CEL mutations cause pancreatic disease through protein misfolding and proteotoxicity, leading to endoplasmic reticulum stress and activation of the unfolded protein response.


Asunto(s)
Estrés del Retículo Endoplásmico , Lipasa/genética , Lipasa/metabolismo , Repeticiones de Minisatélite , Mutación , Proteostasis , Glicosilación , Células HEK293 , Humanos
6.
BMC Med ; 20(1): 110, 2022 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-35351144

RESUMEN

BACKGROUND: Dietary interventions targeting the gut microbiota have been proposed as innovative strategies to improve obesity-associated metabolic disorders. Increasing physical activity (PA) is considered as a key behavioral change for improving health. We have tested the hypothesis that changing the PA status during a nutritional intervention based on prebiotic supplementation can alter or even change the metabolic response to the prebiotic. We confirm in obese subjects and in high-fat diet fed mice that performing PA in parallel to a prebiotic supplementation is necessary to observe metabolic improvements upon inulin. METHODS: A randomized, single-blinded, multicentric, placebo-controlled trial was conducted in obese participants who received 16 g/day native inulin versus maltodextrin, coupled to dietary advice to consume inulin-rich versus -poor vegetables for 3 months, respectively, in addition to dietary caloric restriction. Primary outcomes concern the changes on the gut microbiota composition, and secondary outcomes are related to the measures of anthropometric and metabolic parameters, as well as the evaluation of PA. Among the 106 patients who completed the study, 61 patients filled a questionnaire for PA before and after intervention (placebo: n = 31, prebiotic: n = 30). Except the dietitian (who provided dietary advices and recipes book), all participants and research staff were blinded to the treatments and no advices related to PA were given to participants in order to change their habits. In parallel, a preclinical study was designed combining both inulin supplementation and voluntary exercise in a model of diet-induced obesity in mice. RESULTS: Obese subjects who increased PA during a 3 months intervention with inulin-enriched diet exhibited several clinical improvements such as reduced BMI (- 1.6 kg/m2), decreased liver enzymes and plasma cholesterol, and improved glucose tolerance. Interestingly, the regulations of Bifidobacterium, Dialister, and Catenibacterium genera by inulin were only significant when participants exercised more. In obese mice, we highlighted a greater gut fermentation of inulin and improved glucose homeostasis when PA is combined with prebiotics. CONCLUSION: We conclude that PA level is an important determinant of the success of a dietary intervention targeting the gut microbiota. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03852069 (February 22, 2019 retrospectively registered).


Asunto(s)
Inulina , Obesidad , Animales , Índice de Masa Corporal , Dieta Alta en Grasa , Ejercicio Físico , Humanos , Inulina/farmacología , Ratones , Obesidad/tratamiento farmacológico , Obesidad/metabolismo
7.
Int J Mol Sci ; 23(13)2022 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-35806437

RESUMEN

Type 2 diabetes (T2D) has been considered a relentlessly worsening disease, due to the progressive deterioration of the pancreatic beta cell functional mass. Recent evidence indicates, however, that remission of T2D may occur in variable proportions of patients after specific treatments that are associated with recovery of beta cell function. Here we review the available information on the recovery of beta cells in (a) non-diabetic individuals previously exposed to metabolic stress; (b) T2D patients following low-calorie diets, pharmacological therapies or bariatric surgery; (c) human islets isolated from non-diabetic organ donors that recover from "lipo-glucotoxic" conditions; and (d) human islets isolated from T2D organ donors and exposed to specific treatments. The improvement of insulin secretion reported by these studies and the associated molecular traits unveil the possibility to promote T2D remission by directly targeting pancreatic beta cells.


Asunto(s)
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Insulina/metabolismo , Secreción de Insulina , Células Secretoras de Insulina/metabolismo
8.
Brain Behav Immun ; 94: 289-298, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33515740

RESUMEN

BACKGROUND AND AIMS: Metabolic and behavioural diseases, which are often related to obesity, have been associated to alterations of the gut microbiota considered as an interesting therapeutic target. We have analyzed in a cohort of obese patients treated with prebiotic inulin versus placebo the potential link between gut microbiota changes occurring upon intervention and their effect on psychological parameters (mood and cognition). METHODS: A randomized, single-blinded, multicentric, placebo-controlled trial was conducted in 106 obese patients assigned to two groups: prebiotic versus placebo, who received respectively 16 g/d of native inulin or maltodextrin combined with dietary advice to consume inulin-rich or -poor vegetables for 3 months as well as to restrict caloric intake. Anthropometric measurements, food intake, psychological questionnaires, serum measures, and fecal microbiome sequencing were performed before and after the intervention. RESULTS: Inulin supplementation in obese subjects had moderate beneficial effect on emotional competence and cognitive flexibility. However, an exploratory analysis revealed that some patients exhibiting specific microbial signature -elevated Coprococcus levels at baseline- were more prone to benefit from prebiotic supplementation in terms of mood. Positive responders toward inulin intervention in term of mood also displayed worse metabolic and inflammatory profiles at baseline (increased levels of IL-8, insulin resistance and adiposity). CONCLUSION: This study shows that inulin intake can be helpful to improve mood in obese subjects exhibiting a specific microbial profile. The present work highlights some microbial, metabolic and inflammatory features (IL-8, insulin resistance) which can predict or mediate the beneficial effects of inulin on behaviour in obesity. Food4gut, clinicaltrial.gov: NCT03852069, https://clinicaltrials.gov/ct2/show/NCT03852069.


Asunto(s)
Microbioma Gastrointestinal , Heces , Humanos , Inulina , Obesidad/complicaciones , Prebióticos
9.
Eur J Nutr ; 60(6): 3159-3170, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33544206

RESUMEN

PURPOSE: Inulin-type fructans (ITF) are prebiotic dietary fibre (DF) that may confer beneficial health effects, by interacting with the gut microbiota. We have tested the hypothesis that a dietary intervention promoting inulin intake versus placebo influences fecal microbial-derived metabolites and markers related to gut integrity and inflammation in obese patients. METHODS: Microbiota (16S rRNA sequencing), long- and short-chain fatty acids (LCFA, SCFA), bile acids, zonulin, and calprotectin were analyzed in fecal samples obtained from obese patients included in a randomized, placebo-controlled trial. Participants received either 16 g/d native inulin (prebiotic n = 12) versus maltodextrin (placebo n = 12), coupled to dietary advice to consume inulin-rich versus inulin-poor vegetables for 3 months, in addition to dietary caloric restriction. RESULTS: Both placebo and prebiotic interventions lowered energy and protein intake. A substantial increase in Bifidobacterium was detected after ITF treatment (q = 0.049) supporting our recent data obtained in a larger cohort. Interestingly, fecal calprotectin, a marker of gut inflammation, was reduced upon ITF treatment. Both prebiotic and placebo interventions increased the ratio of tauro-conjugated/free bile acids in feces. Prebiotic treatment did not significantly modify fecal SCFA content but it increased fecal rumenic acid, a conjugated linoleic acid (cis-9, trans-11 CLA) with immunomodulatory properties, that correlated notably to the expansion of Bifidobacterium (p = 0.031; r = 0.052). CONCLUSIONS: Our study demonstrates that ITF-prebiotic intake during 3 months decreases a fecal marker of intestinal inflammation in obese patients. Our data point to a potential contribution of microbial lipid-derived metabolites in gastro-intestinal dysfunction related to obesity. CLINICALTRIALS. GOV IDENTIFIER: NCT03852069 (February 22, 2019 retrospectively, registered).


Asunto(s)
Inulina , Prebióticos , Fibras de la Dieta , Heces , Humanos , Inflamación , Obesidad , ARN Ribosómico 16S , Estudios Retrospectivos
10.
Int J Mol Sci ; 22(2)2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33419045

RESUMEN

The global rise in type 2 diabetes results from a combination of genetic predisposition with environmental assaults that negatively affect insulin action in peripheral tissues and impair pancreatic ß-cell function and survival. Nongenetic heritability of metabolic traits may be an important contributor to the diabetes epidemic. Transfer RNAs (tRNAs) are noncoding RNA molecules that play a crucial role in protein synthesis. tRNAs also have noncanonical functions through which they control a variety of biological processes. Genetic and environmental effects on tRNAs have emerged as novel contributors to the pathogenesis of diabetes. Indeed, altered tRNA aminoacylation, modification, and fragmentation are associated with ß-cell failure, obesity, and insulin resistance. Moreover, diet-induced tRNA fragments have been linked with intergenerational inheritance of metabolic traits. Here, we provide a comprehensive review of how perturbations in tRNA biology play a role in the pathogenesis of monogenic and type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad/genética , Biosíntesis de Proteínas/genética , ARN de Transferencia/genética , Aminoacilación de ARN de Transferencia/genética , Animales , Diabetes Mellitus Tipo 2/metabolismo , Interacción Gen-Ambiente , Humanos , Células Secretoras de Insulina/metabolismo , Procesamiento Postranscripcional del ARN/genética , ARN de Transferencia/metabolismo
11.
Gut ; 69(11): 1975-1987, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32041744

RESUMEN

OBJECTIVE: The gut microbiota has been proposed as an interesting therapeutic target for metabolic disorders. Inulin as a prebiotic has been shown to lessen obesity and related diseases. The aim of the current study was to investigate whether preintervention gut microbiota characteristics determine the physiological response to inulin. DESIGN: The stools from four obese donors differing by microbial diversity and composition were sampled before the dietary intervention and inoculated to antibiotic-pretreated mice (hum-ob mice; humanised obese mice). Hum-ob mice were fed with a high-fat diet and treated with inulin. Metabolic and microbiota changes on inulin treatment in hum-ob mice were compared with those obtained in a cohort of obese individuals supplemented with inulin for 3 months. RESULTS: We show that hum-ob mice colonised with the faecal microbiota from different obese individuals differentially respond to inulin supplementation on a high-fat diet. Among several bacterial genera, Barnesiella, Bilophila, Butyricimonas, Victivallis, Clostridium XIVa, Akkermansia, Raoultella and Blautia correlated with the observed metabolic outcomes (decrease in adiposity and hepatic steatosis) in hum-ob mice. In addition, in obese individuals, the preintervention levels of Anaerostipes, Akkermansia and Butyricicoccus drive the decrease of body mass index in response to inulin. CONCLUSION: These findings support that characterising the gut microbiota prior to nutritional intervention with prebiotics is important to increase the positive outcome in the context of obesity and metabolic disorders.


Asunto(s)
Suplementos Dietéticos , Microbioma Gastrointestinal/efectos de los fármacos , Inulina/uso terapéutico , Obesidad/microbiología , Obesidad/terapia , Prebióticos , Animales , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Método Simple Ciego
12.
Diabetologia ; 63(2): 395-409, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31796987

RESUMEN

AIMS/HYPOTHESIS: During the onset of type 2 diabetes, excessive dietary intake of saturated NEFA and fructose lead to impaired insulin production and secretion by insulin-producing pancreatic beta cells. The majority of data on the deleterious effects of lipids on functional beta cell mass were obtained either in vivo in rodent models or in vitro using rodent islets and beta cell lines. Translating data from rodent to human beta cells remains challenging. Here, we used the human beta cell line EndoC-ßH1 and analysed its sensitivity to a lipotoxic and glucolipotoxic (high palmitate with or without high glucose) insult, as a way to model human beta cells in a type 2 diabetes environment. METHODS: EndoC-ßH1 cells were exposed to palmitate after knockdown of genes related to saturated NEFA metabolism. We analysed whether and how palmitate induces apoptosis, stress and inflammation and modulates beta cell identity. RESULTS: EndoC-ßH1 cells were insensitive to the deleterious effects of saturated NEFA (palmitate and stearate) unless stearoyl CoA desaturase (SCD) was silenced. SCD was abundantly expressed in EndoC-ßH1 cells, as well as in human islets and human induced pluripotent stem cell-derived beta cells. SCD silencing induced markers of inflammation and endoplasmic reticulum stress and also IAPP mRNA. Treatment with the SCD products oleate or palmitoleate reversed inflammation and endoplasmic reticulum stress. Upon SCD knockdown, palmitate induced expression of dedifferentiation markers such as SOX9, MYC and HES1. Interestingly, SCD knockdown by itself disrupted beta cell identity with a decrease in mature beta cell markers INS, MAFA and SLC30A8 and decreased insulin content and glucose-stimulated insulin secretion. CONCLUSIONS/INTERPRETATION: The present study delineates an important role for SCD in the protection against lipotoxicity and in the maintenance of human beta cell identity. DATA AVAILABILITY: Microarray data and all experimental details that support the findings of this study have been deposited in in the GEO database with the GSE130208 accession code.


Asunto(s)
Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Ácido Palmítico/farmacología , Estearoil-CoA Desaturasa/metabolismo , Apoptosis/efectos de los fármacos , Células Cultivadas , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Células Madre Pluripotentes Inducidas/metabolismo , Secreción de Insulina/efectos de los fármacos , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factor de Transcripción SOX9/metabolismo , Factor de Transcripción HES-1/metabolismo
13.
BMC Genomics ; 21(1): 590, 2020 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-32847508

RESUMEN

BACKGROUND: Prolonged exposure to elevated free fatty acids induces ß-cell failure (lipotoxicity) and contributes to the pathogenesis of type 2 diabetes. In vitro exposure of ß-cells to the saturated free fatty acid palmitate is a valuable model of lipotoxicity, reproducing features of ß-cell failure observed in type 2 diabetes. In order to map the ß-cell response to lipotoxicity, we combined RNA-sequencing of palmitate-treated human islets with iTRAQ proteomics of insulin-secreting INS-1E cells following a time course exposure to palmitate. RESULTS: Crossing transcriptome and proteome of palmitate-treated ß-cells revealed 85 upregulated and 122 downregulated genes at both transcript and protein level. Pathway analysis identified lipid metabolism, oxidative stress, amino-acid metabolism and cell cycle pathways among the most enriched palmitate-modified pathways. Palmitate induced gene expression changes compatible with increased free fatty acid mitochondrial import and ß-oxidation, decreased lipogenesis and modified cholesterol transport. Palmitate modified genes regulating endoplasmic reticulum (ER) function, ER-to-Golgi transport and ER stress pathways. Furthermore, palmitate modulated cAMP/protein kinase A (PKA) signaling, inhibiting expression of PKA anchoring proteins and downregulating the GLP-1 receptor. SLC7 family amino-acid transporters were upregulated in response to palmitate but this induction did not contribute to ß-cell demise. To unravel critical mediators of lipotoxicity upstream of the palmitate-modified genes, we identified overrepresented transcription factor binding sites and performed network inference analysis. These identified LXR, PPARα, FOXO1 and BACH1 as key transcription factors orchestrating the metabolic and oxidative stress responses to palmitate. CONCLUSIONS: This is the first study to combine transcriptomic and sensitive time course proteomic profiling of palmitate-exposed ß-cells. Our results provide comprehensive insight into gene and protein expression changes, corroborating and expanding beyond previous findings. The identification of critical drivers and pathways of the ß-cell lipotoxic response points to novel therapeutic targets for type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Apoptosis , Humanos , Palmitatos/toxicidad , Proteoma , Proteómica , Transcriptoma
14.
Nucleic Acids Res ; 46(19): 10302-10318, 2018 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-30247717

RESUMEN

Transfer RNAs (tRNAs) are non-coding RNA molecules essential for protein synthesis. Post-transcriptionally they are heavily modified to improve their function, folding and stability. Intronic polymorphisms in CDKAL1, a tRNA methylthiotransferase, are associated with increased type 2 diabetes risk. Loss-of-function mutations in TRMT10A, a tRNA methyltransferase, are a monogenic cause of early onset diabetes and microcephaly. Here we confirm the role of TRMT10A as a guanosine 9 tRNA methyltransferase, and identify tRNAGln and tRNAiMeth as two of its targets. Using RNA interference and induced pluripotent stem cell-derived pancreatic ß-like cells from healthy controls and TRMT10A-deficient patients we demonstrate that TRMT10A deficiency induces oxidative stress and triggers the intrinsic pathway of apoptosis in ß-cells. We show that tRNA guanosine 9 hypomethylation leads to tRNAGln fragmentation and that 5'-tRNAGln fragments mediate TRMT10A deficiency-induced ß-cell death. This study unmasks tRNA hypomethylation and fragmentation as a hitherto unknown mechanism of pancreatic ß-cell demise relevant to monogenic and polygenic forms of diabetes.


Asunto(s)
Metilación de ADN , Diabetes Mellitus/genética , Células Secretoras de Insulina/metabolismo , Metiltransferasas/genética , ARN de Transferencia/metabolismo , Anciano , Animales , Apoptosis/genética , Muerte Celular/genética , Diferenciación Celular/genética , Células Cultivadas , Fragmentación del ADN , Diabetes Mellitus/metabolismo , Ligamiento Genético , Humanos , Células Madre Pluripotentes Inducidas/fisiología , Células Secretoras de Insulina/fisiología , Metiltransferasas/deficiencia , Metiltransferasas/metabolismo , Persona de Mediana Edad , Mutación , Ratas
15.
FASEB J ; 32(3): 1524-1536, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29133342

RESUMEN

Prolonged exercise has positive metabolic effects in obese or diabetic individuals. These effects are usually ascribed to improvements in insulin sensitivity. We evaluated whether exercise also generates circulating signals that protect human and rodent ß cells against endoplasmic reticulum (ER) stress and apoptosis. For this purpose, we obtained serum from humans or mice before and after an 8 wk training period. Exposure of human islets or mouse or rat ß cells to human or rodent sera, respectively, obtained from trained individuals reduced cytokine (IL-1ß+IFN-γ)- or chemical ER stressor-induced ß-cell ER stress and apoptosis, at least in part via activation of the transcription factor STAT3. These findings indicate that exercise training improves human and rodent ß-cell survival under diabetogenic conditions and support lifestyle interventions as a protective approach for both type 1 and 2 diabetes.-Paula, F. M. M., Leite, N. C., Borck, P. C., Freitas-Dias, R., Cnop, M., Chacon-Mikahil, M. P. T., Cavaglieri, C. R., Marchetti, P., Boschero, A. C., Zoppi, C. C., Eizirik, D. L. Exercise training protects human and rodent ß cells against endoplasmic reticulum stress and apoptosis.


Asunto(s)
Apoptosis/fisiología , Estrés del Retículo Endoplásmico/fisiología , Ejercicio Físico/fisiología , Células Secretoras de Insulina/metabolismo , Condicionamiento Físico Animal/fisiología , Animales , Femenino , Humanos , Células Secretoras de Insulina/citología , Masculino , Ratones , Ratas , Ratas Wistar
16.
Genomics ; 110(2): 98-111, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28911974

RESUMEN

The GLIS family zinc finger 3 isoform (GLIS3) is a risk gene for Type 1 and Type 2 diabetes, glaucoma and Alzheimer's disease endophenotype. We identified GLIS3 binding sites in insulin secreting cells (INS1) (FDR q<0.05; enrichment range 1.40-9.11 fold) sharing the motif wrGTTCCCArTAGs, which were enriched in genes involved in neuronal function and autophagy and in risk genes for metabolic and neuro-behavioural diseases. We confirmed experimentally Glis3-mediated regulation of the expression of genes involved in autophagy and neuron function in INS1 and neuronal PC12 cells. Naturally-occurring coding polymorphisms in Glis3 in the Goto-Kakizaki rat model of type 2 diabetes were associated with increased insulin production in vitro and in vivo, suggestive alteration of autophagy in PC12 and INS1 and abnormal neurogenesis in hippocampus neurons. Our results support biological pleiotropy of GLIS3 in pathologies affecting ß-cells and neurons and underline the existence of trans­nosology pathways in diabetes and its co-morbidities.


Asunto(s)
Células Secretoras de Insulina/metabolismo , Neuronas/metabolismo , Factores de Transcripción/metabolismo , Animales , Autofagia , Sitios de Unión , Línea Celular Tumoral , Células Cultivadas , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Hipocampo/citología , Masculino , Neurogénesis , Neuronas/citología , Células PC12 , Polimorfismo Genético , Unión Proteica , Ratas , Ratas Sprague-Dawley , Factores de Transcripción/química , Factores de Transcripción/genética
17.
Diabetologia ; 61(12): 2516-2519, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30284016

RESUMEN

In this issue of Diabetologia, Alavi and Werner ( https://doi.org/10.1007/s00125-018-4676-1 ) criticise the attempts to use positron emission tomography (PET) for in vivo imaging of pancreatic beta cells, which they consider as 'futile'. In support of this strong statement, they point out the limitations of PET imaging, which they believe render beta cell mass impossible to estimate using this method. In our view, the Alavi and Werner presentation of the technical limitations of PET imaging does not reflect the current state of the art, which leads them to questionable conclusions towards the feasibility of beta cell imaging using this approach. Here, we put forward arguments in favour of continuing the development of innovative technologies enabling in vivo imaging of pancreatic beta cells and concisely present the current state of the art regarding putative technical limitations of PET imaging. Indeed, far from being a 'futile' effort, we demonstrate that beta cell imaging is now closer than ever to becoming a long-awaited clinical reality.


Asunto(s)
Células Secretoras de Insulina , Inutilidad Médica , Páncreas , Tomografía de Emisión de Positrones
18.
J Biol Chem ; 292(36): 14977-14988, 2017 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-28698383

RESUMEN

Cytokine-induced endoplasmic reticulum (ER) stress is one of the molecular mechanisms underlying pancreatic ß-cell demise in type 1 diabetes. Thrombospondin 1 (THBS1) was recently shown to promote ß-cell survival during lipotoxic stress. Here we show that ER-localized THBS1 is cytoprotective to rat, mouse, and human ß-cells exposed to cytokines or thapsigargin-induced ER stress. THBS1 confers cytoprotection by maintaining expression of mesencephalic astrocyte-derived neutrotrophic factor (MANF) in ß-cells and thereby prevents the BH3-only protein BIM (BCL2-interacting mediator of cell death)-dependent triggering of the mitochondrial pathway of apoptosis. Prolonged exposure of ß-cells to cytokines or thapsigargin leads to THBS1 and MANF degradation and loss of this prosurvival mechanism. Approaches that sustain intracellular THBS1 and MANF expression in ß-cells should be explored as a cytoprotective strategy in type 1 diabetes.


Asunto(s)
Inflamación/metabolismo , Células Secretoras de Insulina/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Trombospondina 1/metabolismo , Animales , Células Cultivadas , Citocinas/metabolismo , Retículo Endoplásmico/metabolismo , Humanos , Células Secretoras de Insulina/efectos de los fármacos , Ratones , Factores de Crecimiento Nervioso/antagonistas & inhibidores , Estrés Oxidativo , Tapsigargina/farmacología
19.
Crit Care ; 22(1): 182, 2018 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-30071851

RESUMEN

There is considerable physiological and clinical evidence of harm and increased risk of death associated with dysglycemia in critical care. However, glycemic control (GC) currently leads to increased hypoglycemia, independently associated with a greater risk of death. Indeed, recent evidence suggests GC is difficult to safely and effectively achieve for all patients. In this review, leading experts in the field discuss this evidence and relevant data in diabetology, including the artificial pancreas, and suggest how safe, effective GC can be achieved in critically ill patients in ways seeking to mimic normal islet cell function. The review is structured around the specific clinical hurdles of: understanding the patient's metabolic state; designing GC to fit clinical practice, safety, efficacy, and workload; and the need for standardized metrics. These aspects are addressed by reviewing relevant recent advances in science and technology. Finally, we provide a set of concise recommendations to advance the safety, quality, consistency, and clinical uptake of GC in critical care. This review thus presents a roadmap toward better, more personalized metabolic care and improved patient outcomes.


Asunto(s)
Carga Glucémica/fisiología , Islotes Pancreáticos/metabolismo , Enfermedad Crítica/rehabilitación , Carga Glucémica/efectos de los fármacos , Humanos , Hiperglucemia/metabolismo , Hipoglucemia/metabolismo , Metabolismo/fisiología
20.
Hum Mol Genet ; 24(8): 2274-86, 2015 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-25552656

RESUMEN

Friedreich's ataxia (FRDA) is a neurodegenerative disorder associated with cardiomyopathy and diabetes. Effective therapies for FRDA are an urgent unmet need; there are currently no options to prevent or treat this orphan disease. FRDA is caused by reduced expression of the mitochondrial protein frataxin. We have previously demonstrated that pancreatic ß-cell dysfunction and death cause diabetes in FRDA. This is secondary to mitochondrial dysfunction and apoptosis but the underlying molecular mechanisms are not known. Here we show that ß-cell demise in frataxin deficiency is the consequence of oxidative stress-mediated activation of the intrinsic pathway of apoptosis. The pro-apoptotic Bcl-2 family members Bad, DP5 and Bim are the key mediators of frataxin deficiency-induced ß-cell death. Importantly, the intrinsic pathway of apoptosis is also activated in FRDA patients' induced pluripotent stem cell-derived neurons. Interestingly, cAMP induction normalizes mitochondrial oxidative status and fully prevents activation of the intrinsic pathway of apoptosis in frataxin-deficient ß-cells and neurons. This preclinical study suggests that incretin analogs hold potential to prevent/delay both diabetes and neurodegeneration in FRDA.


Asunto(s)
Apoptosis , Ataxia de Friedreich/fisiopatología , Células Secretoras de Insulina/citología , Neuronas/citología , Animales , Línea Celular , Diabetes Mellitus/etiología , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatología , Femenino , Ataxia de Friedreich/complicaciones , Ataxia de Friedreich/genética , Ataxia de Friedreich/metabolismo , Humanos , Células Secretoras de Insulina/metabolismo , Proteínas de Unión a Hierro/genética , Proteínas de Unión a Hierro/metabolismo , Masculino , Persona de Mediana Edad , Neuronas/metabolismo , Estrés Oxidativo , Ratas , Ratas Wistar , Frataxina
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