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1.
Cell Transplant ; 32: 9636897231179642, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37318185

RESUMO

High pancreatic islet sensitivity to hypoxia is an important issue in the field of pancreatic islet transplantation. A promising strategy to improve islet oxygenation in hypoxic conditions is to leverage the properties of hemoglobin as a natural carrier of oxygen. Studies using human or bovine hemoglobin have failed to demonstrate efficacy, probably due to the molecule being unstable in the absence of protective erythrocytes. Recently, marine worm hemoglobins have been shown to be more stable and to possess higher oxygen carrier potential, with 156 oxygen binding sites per molecule compared to four in humans. Previous studies have shown the beneficial effects of two marine worm hemoglobins, M101 and M201, on nonhuman pancreatic islets. However, their effects on human islets have not been tested or compared. In this study, we assessed the impact of both molecules during human islet culture in vitro under hypoxic conditions. Human islets were exposed to both molecules for 24 h in high islet density-induced hypoxia [600 islet equivalents (IEQ)/cm²]. M101 and M201 reduced the release of hypoxic (VEGF) and apoptotic (cyt c) markers in the medium after 24-h culture. Human islet function or viability was improved in vitro in the presence of these oxygen carriers. Thus, the utilization of M101 or M201 could be a safe and easy way to improve human islet oxygenation and survival in hypoxic conditions as observed during islet culture prior to transplantation or islet encapsulation.


Assuntos
Ilhotas Pancreáticas , Oxigênio , Humanos , Oxigênio/farmacologia , Hipóxia , Sítios de Ligação , Eritrócitos
2.
Nutrients ; 15(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37049569

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease mainly characterized by the hepatic accumulation of lipid inducing a deregulation of ß-oxidation. Its advanced form is non-alcoholic steatohepatitis (NASH), which, in addition to lipid accumulation, induces hepatocellular damage, oxidative stress and fibrosis that can progress to cirrhosis and to its final stage: hepatocellular carcinoma (HCC). To date, no specific therapeutic treatment exists. The implications of organ crosstalk have been highlighted in many metabolic disorders, such as diabetes, metabolic-associated liver diseases and obesity. Skeletal muscle, in addition to its role as a reservoir and consumer of energy and carbohydrate metabolism, is involved in this inter-organs' communication through different secreted products: myokines, exosomes and enzymes, for example. Interestingly, resistance exercise has been shown to have a beneficial impact on different metabolic pathways, such as lipid oxidation in different organs through their secreted products. In this review, we will mainly focus on myokines and their effects on non-alcoholic fatty liver disease, and their complication: non-alcoholic steatohepatitis and HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Fígado/metabolismo , Fibrose , Lipídeos
3.
Front Endocrinol (Lausanne) ; 13: 1035159, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36407314

RESUMO

Circular RNAs (circRNAs) are class of non-coding RNA, which are characterized by a covalently closed loop structure. Functionally they can act on cellular physiology, notably by sponging microRNAs (miR), regulating gene expression or interacting with binding protein. To date, circRNAs might represent an interesting, underexploited avenue for new target discovery for therapeutic applications, especially in the liver. The first characteristic of non-alcoholic fatty liver disease (NAFLD) is hepatic cholesterol accumulation, followed by its advanced form of the affection, nonalcoholic steatohepatitis (NASH), due to the occurrence of lobular inflammation, irreversible fibrosis, and in some cases hepatocellular carcinoma (HCC). Therefore, studies have investigated the importance of the dysregulation of circRNAs in the onset of metabolic disorders. In this review, we summarize the potential role of circRNAs in the development of metabolic diseases associated with the liver such as NAFLD or NASH, and their potential to become therapeutic strategies for these pathologies.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/epidemiologia , RNA Circular/genética , Neoplasias Hepáticas/etiologia
4.
Front Endocrinol (Lausanne) ; 13: 836344, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35185804

RESUMO

The regulation of insulin secretion is under control of a complex inter-organ/cells crosstalk involving various metabolites and/or physical connections. In this review, we try to illustrate with current knowledge how ß-cells communicate with other cell types and organs in physiological and pathological contexts. Moreover, this review will provide a better understanding of the microenvironment and of the context in which ß-cells exist and how this can influence their survival and function. Recent studies showed that ß-cell insulin secretion is regulated also by a direct and indirect inter-organ/inter-cellular communication involving various factors, illustrating the idea of "the hidden face of the iceberg". Moreover, any disruption on the physiological communication between ß-cells and other cells or organs can participate on diabetes onset. Therefore, for new anti-diabetic treatments' development, it is necessary to consider the entire network of cells and organs involved in the regulation of ß-cellular function and no longer just ß-cell or pancreatic islet alone. In this context, we discuss here the intra-islet communication, the ß-cell/skeletal muscle, ß-cell/adipose tissue and ß-cell/liver cross talk.


Assuntos
Diabetes Mellitus , Células Secretoras de Insulina , Ilhotas Pancreáticas , Diabetes Mellitus/metabolismo , Humanos , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo
5.
Diabetes ; 70(9): 2026-2041, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34183374

RESUMO

Most obese and insulin-resistant individuals do not develop diabetes. This is the result of the capacity of ß-cells to adapt and produce enough insulin to cover the needs of the organism. The underlying mechanism of ß-cell adaptation in obesity, however, remains unclear. Previous studies have suggested a role for STAT3 in mediating ß-cell development and human glucose homeostasis, but little is known about STAT3 in ß-cells in obesity. We observed enhanced cytoplasmic expression of STAT3 in severely obese subjects with diabetes. To address the functional role of STAT3 in adult ß-cells, we generated mice with tamoxifen-inducible partial or full deletion of STAT3 in ß-cells and fed them a high-fat diet before analysis. Interestingly, ß-cell heterozygous and homozygous STAT3-deficient mice showed glucose intolerance when fed a high-fat diet. Gene expression analysis with RNA sequencing showed that reduced expression of mitochondrial genes in STAT3 knocked down human EndoC-ß1H cells, confirmed in FACS-purified ß-cells from obese STAT3-deficient mice. Moreover, silencing of STAT3 impaired mitochondria activity in EndoC-ß1H cells and human islets, suggesting a mechanism for STAT3-modulated ß-cell function. Our study postulates STAT3 as a novel regulator of ß-cell function in obesity.


Assuntos
Intolerância à Glucose/metabolismo , Células Secretoras de Insulina/metabolismo , Mitocôndrias/metabolismo , Obesidade/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Glicemia/metabolismo , Dieta Hiperlipídica , Genes Mitocondriais , Intolerância à Glucose/genética , Humanos , Insulina/metabolismo , Camundongos , Camundongos Knockout , Mitocôndrias/genética , Obesidade/genética , Fator de Transcrição STAT3/genética
6.
Nat Commun ; 11(1): 5611, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33154349

RESUMO

Fine-tuning of insulin release from pancreatic ß-cells is essential to maintain blood glucose homeostasis. Here, we report that insulin secretion is regulated by a circular RNA containing the lariat sequence of the second intron of the insulin gene. Silencing of this intronic circular RNA in pancreatic islets leads to a decrease in the expression of key components of the secretory machinery of ß-cells, resulting in impaired glucose- or KCl-induced insulin release and calcium signaling. The effect of the circular RNA is exerted at the transcriptional level and involves an interaction with the RNA-binding protein TAR DNA-binding protein 43 kDa (TDP-43). The level of this circularized intron is reduced in the islets of rodent diabetes models and of type 2 diabetic patients, possibly explaining their impaired secretory capacity. The study of this and other circular RNAs helps understanding ß-cell dysfunction under diabetes conditions, and the etiology of this common metabolic disorder.


Assuntos
Secreção de Insulina/genética , Insulina/genética , Íntrons , RNA Circular/metabolismo , Animais , Sinalização do Cálcio , Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Regulação da Expressão Gênica , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Camundongos , RNA Circular/genética , Ratos
7.
J Biol Chem ; 295(49): 16510-16528, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-32934005

RESUMO

Elevated levels of fasting insulin release and insufficient glucose-stimulated insulin secretion (GSIS) are hallmarks of diabetes. Studies have established cross-talk between integrin signaling and insulin activity, but more details of how integrin-dependent signaling impacts the pathophysiology of diabetes are needed. Here, we dissected integrin-dependent signaling pathways involved in the regulation of insulin secretion in ß-cells and studied their link to the still debated autocrine regulation of insulin secretion by insulin/insulin-like growth factor (IGF) 2-AKT signaling. We observed for the first time a cooperation between different AKT isoforms and focal adhesion kinase (FAK)-dependent adhesion signaling, which either controlled GSIS or prevented insulin secretion under fasting conditions. Indeed, ß-cells form integrin-containing adhesions, which provide anchorage to the pancreatic extracellular matrix and are the origin of intracellular signaling via FAK and paxillin. Under low-glucose conditions, ß-cells adopt a starved adhesion phenotype consisting of actin stress fibers and large peripheral focal adhesion. In contrast, glucose stimulation induces cell spreading, actin remodeling, and point-like adhesions that contain phospho-FAK and phosphopaxillin, located in small protrusions. Rat primary ß-cells and mouse insulinomas showed an adhesion remodeling during GSIS resulting from autocrine insulin/IGF2 and AKT1 signaling. However, under starving conditions, the maintenance of stress fibers and the large adhesion phenotype required autocrine IGF2-IGF1 receptor signaling mediated by AKT2 and elevated FAK-kinase activity and ROCK-RhoA levels but low levels of paxillin phosphorylation. This starved adhesion phenotype prevented excessive insulin granule release to maintain low insulin secretion during fasting. Thus, deregulation of the IGF2 and adhesion-mediated signaling may explain dysfunctions observed in diabetes.


Assuntos
Fator de Crescimento Insulin-Like II/metabolismo , Integrinas/metabolismo , Transdução de Sinais , Actinas/metabolismo , Animais , Comunicação Autócrina , Adesão Celular/efeitos dos fármacos , Quinase 1 de Adesão Focal/metabolismo , Glucose/farmacologia , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Camundongos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ratos , Receptor de Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tirfostinas/farmacologia , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo
8.
Hypertension ; 76(4): 1280-1288, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32862710

RESUMO

To investigate the impact of visit-to-visit systolic blood pressure variability (BPV), diastolic BPV, mean arterial pressure variability, and pulse pressure variability on cognitive decline and incident dementia in noninstitutionalized patients aged ≥65 years. A total of 3319 subjects from the S.AGES (Sujets AGÉS-Aged Subjects) cohort underwent clinical examinations every 6 months during 3 years. Variability was evaluated using standard deviation (SD), coefficient of variation, average real variability, successive variation, variation independent of mean, and residual SD. Cognition was assessed using the Mini-Mental State Examination and dementia with the Diagnostic Statistical Manual of Mental Disorders. Linear mixed models and Cox proportional hazards models were used. Higher systolic BPV was associated with poorer cognition independently of baseline SBP: adjusted 1-SD increase of coefficient of variation: ß (SE)=-0.12 (0.06), P=0.04. Similar results were observed for diastolic BPV and mean arterial pressure variability: ß (SE)=-0.20 (0.06), P<0.001 for both. Higher pulse pressure variability was no longer associated with cognitive function after adjustment for age, except with residual SD (P=0.02). Among the 3319 subjects, 93 (2.8%) developed dementia. Higher systolic BPV was associated with greater dementia risk (adjusted 1-SD increase of coefficient of variation: hazard ratios=1.23 [95% CI, 1.01-1.50], P=0.04). Similar results were found for diastolic BPV and mean arterial pressure variability (P<0.01). Pulse pressure variability was not associated with dementia risk. Beyond hypertension, higher BPV is a major clinical predictor of cognitive impairment and dementia. Further studies are needed to assess whether controlling BP instability could be a promising interventional target in preserving cognition among older adults.


Assuntos
Pressão Sanguínea/fisiologia , Cognição/fisiologia , Disfunção Cognitiva/fisiopatologia , Demência/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Determinação da Pressão Arterial , Disfunção Cognitiva/diagnóstico , Demência/diagnóstico , Demência/fisiopatologia , Progressão da Doença , Feminino , Humanos , Incidência , Masculino , Testes de Estado Mental e Demência
9.
Nutrients ; 12(7)2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32646010

RESUMO

Lifestyle interventions have been shown to reverse hyperglycemia to normoglycemia. However, these effects are not long-lasting and are accompanied with high dropout rates. As formula diets have been shown to be simple in usage and effective in improving glycemic control, we hypothesised that adding a low-carbohydrate and energy deficit formula diet to a low-intensity lifestyle intervention is superior in reversing prediabetes compared with lifestyle intervention alone. In this predefined subanalysis of an international, multicenter randomised controlled trial (Almased Concept against Overweight and Obesity and Related Health Risk (ACOORH) study (ID DRKS00006811)), 141 persons with prediabetes were randomised (1:2) into either a control group with lifestyle intervention only (CON, n = 45) or a lifestyle intervention group accompanied with a formula diet (INT, n = 96). Both groups were equipped with telemonitoring devices. INT received a low-carbohydrate formula diet substituting three meals/day (~1200 kcal/day) within the first week, two meals/day during week 2-4, and one meal/day during week 5-26 (1300-1500 kcal/day). Follow-up was performed after 52 weeks and 105 participants (75%, INT: n = 74; CON: n = 31) finished the 26-week intervention phase. Follow-up data after 52 weeks were available from 93 participants (66%, INT: n = 65; CON: n = 28). Compared with CON, significantly more INT participants converted to normoglycemia after 52 weeks (50% vs. 31%; p < 0.05). The risk reduction led to a number-needed-to-treat of 5.3 for INT. Lifestyle intervention with a low-carbohydrate formula diet reduces prediabetes prevalence stronger than lifestyle intervention alone and is effective for type 2 diabetes prevention.


Assuntos
Dieta com Restrição de Carboidratos/métodos , Estado Pré-Diabético/dietoterapia , Adulto , Glicemia , Diabetes Mellitus Tipo 2/prevenção & controle , Feminino , Alimentos Formulados , Humanos , Hiperglicemia/dietoterapia , Estilo de Vida , Masculino , Refeições , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/dietoterapia , Sobrepeso/complicações , Sobrepeso/dietoterapia , Estado Pré-Diabético/complicações , Comportamento de Redução do Risco
10.
Antioxid Redox Signal ; 32(9): 618-635, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-31931619

RESUMO

Aims: Nicotinamide adenine dinucleotide phosphate oxidases (NOX-es) produce reactive oxygen species and modulate ß-cell insulin secretion. Islets of type 2 diabetic subjects present elevated expression of NOX5. Here, we sought to characterize regulation of NOX5 expression in human islets in vitro and to uncover the relevance of NOX5 in islet function in vivo using a novel mouse model expressing NOX5 in doxycycline-inducible, ß-cell-specific manner (RIP/rtTA/NOX5 mice). Results:In situ hybridization and immunohistochemistry employed on pancreatic sections demonstrated NOX5 messenger ribonucleic acid (mRNA) and protein expressions in human islets. In cultures of dispersed islets, NOX5 protein was observed in somatostatin-positive (δ) cells in basal (2.8 mM glucose) conditions. Small interfering ribonucleic acid (siRNA)-mediated knockdown of NOX5 in human islets cultured in basal glucose concentrations resulted in diminished glucose-induced insulin secretion (GIIS) in vitro. However, when islets were preincubated in high (16.7 mM) glucose media for 12 h, NOX5 appeared also in insulin-positive (ß) cells. In vivo, mice with ß-cell NOX5 expression developed aggravated impairment of GIIS compared with control mice when challenged with 14 weeks of high-fat diet. Similarly, in vitro palmitate preincubation resulted in more severe reduction of insulin release in islets of RIP/rtTA/NOX5 mice compared with their control littermates. Decreased insulin secretion was most distinct in response to theophylline stimulation, suggesting impaired cyclic adenosine monophosphate (cAMP)-mediated signaling due to increased phosphodiesterase activation. Innovation and Conclusions: Our data provide the first insight into the complex regulation and function of NOX5 in islets implying an important role for NOX5 in δ-cell-mediated intraislet crosstalk in physiological circumstances but also identifying it as an aggravating factor in ß-cell failure in diabetic conditions.


Assuntos
Ilhotas Pancreáticas/metabolismo , NADPH Oxidase 5/genética , Animais , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Feminino , Humanos , Secreção de Insulina/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , NADPH Oxidase 5/metabolismo
11.
Exp Clin Endocrinol Diabetes ; 128(5): 311-318, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-30134475

RESUMO

AIMS: The main aim of the present work was to assess if sex influences the occurrence of major clinical events in elderly people with type 2 diabetes followed up in the primary care. METHODS: 983 subjects aged ≥65years with type 2 diabetes were included by 213 general practitioners and followed up prospectively for three years. Major clinical events were recorded every six month. The first endpoint was a composite of all-cause death and major vascular events (acute coronary syndrome, non-fatal stroke or transient ischemic attack, or revascularization for peripheral artery disease). The second endpoint was all-cause hospitalization. The occurrence of each endpoint was analyzed in order to estimate the role of sex and determine other predictors of major clinical events. RESULTS: At baseline, women were older than men but they had a lower prevalence of coexisting diseases (cardiovascular disease and cancer) and equivalent diabetes control (Glycated hemoglobin A1C: 6.9%±0.9 vs. 7.0%±1.1). Over the follow-up period, women were at lower risk to develop the composite endpoint (HR 0.60, 95% CI 0.40-0.91, p=0.016) and the hospitalization endpoint (OR 0.71, 95% CI 0.52-0.96, p=0.029). Coexisting diseases, functional ability and concomitant medications emerged as significant predictors of both endpoints. CONCLUSIONS: Elderly women with well-controlled type 2 diabetes were less likely to experience major clinical events than their male counterparts. More studies are needed to determine the reasons for the higher hospitalization rate in men.


Assuntos
Doenças Cardiovasculares/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Medicina Geral/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Atenção Primária à Saúde/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/mortalidade , Transtornos Cerebrovasculares/epidemiologia , Comorbidade , Feminino , Seguimentos , França/epidemiologia , Humanos , Masculino , Caracteres Sexuais , Fatores Sexuais
12.
Acta Biomater ; 102: 259-272, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31811957

RESUMO

Islet transplantation is one of the most efficient cell therapies used in clinics and could treat a large proportion of patients with diabetes. However, it is limited by the high requirement of pancreas necessary to provide the sufficient surviving islet mass in the hepatic tissue and restore normoglycaemia. Reduction in organ procurement requirements could be achieved by extrahepatic transplantation using a biomaterial that enhances islet survival and function. We report a plasma-supplemented hydroxypropyl methylcellulose (HPMC) hydrogel, engineered specifically using a newly developed technique for intra-omental islet infusion, known as hOMING (h-Omental Matrix Islet filliNG). The HPMC hydrogel delivered islets with better performance than that of the classical intrahepatic infusion. After the validation of the HPMC suitability for islets in vivo and in vitro, plasma supplementation modified the rheological properties of HPMC without affecting its applicability with hOMING. The biomaterial association was proven to be more efficient both in vitro and in vivo, with better islet viability and function than that of the current clinical intrahepatic delivery technique. Indeed, when the islet mass was decreased by 25% or 35%, glycaemia control was observed in the group of plasma-supplemented hydrogels, whereas no regulation was observed in the hepatic group. Plasma gelation, observed immediately post infusion, decreased anoïkis and promoted vascularisation. To conclude, the threshold mass for islet transplantation could be decreased using HPMC-Plasma combined with the hOMING technique. The simplicity of the hOMING technique and the already validated use of its components could facilitate its transfer to clinics. STATEMENT OF SIGNIFICANCE: One of the major limitations for the broad deployment of current cell therapy for brittle type 1 diabetes is the islets' destruction during the transplantation process. Retrieved from their natural environment, the islets are grafted into a foreign tissue, which triggers massive cell loss. It is mandatory to provide the islets with an 3D environment specifically designed for promoting isletimplantation to improve cell therapy outcomes. For this aim, we combined HPMC and plasma. HPMC provides suitable rheological properties to the plasma to be injectable and be maintained in the omentum. Afterwards, the plasma polymerises around the graft in vivo, thereby allowing their optimal integration into their transplantation site. As a result, the islet mass required to obtain glycaemic control was reduced by 35%.


Assuntos
Diabetes Mellitus Experimental/cirurgia , Excipientes/farmacologia , Controle Glicêmico/métodos , Hidrogéis/farmacologia , Derivados da Hipromelose/farmacologia , Transplante das Ilhotas Pancreáticas , Animais , Difusão , Excipientes/química , Hidrogéis/química , Derivados da Hipromelose/química , Ilhotas Pancreáticas/citologia , Masculino , Omento/cirurgia , Oxigênio/química , Oxigênio/metabolismo , Ratos Endogâmicos Lew , Ratos Wistar , Viscosidade
13.
J Cell Mol Med ; 23(12): 8025-8034, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31602751

RESUMO

Ischaemia impairs organ quality during preservation in a time-dependent manner, due to a lack of oxygen supply. Its impact on pancreas and islet transplantation outcome has been demonstrated by a correlation between cold ischaemia time and poor islet isolation efficiency. Our goal in the present study was to improve pancreas and islet quality using a novel natural oxygen carrier (M101, 2 g/L), which has been proven safe and efficient in other clinical applications, including kidney transplantation, and for several pre-clinical transplantation models. When M101 was added to the preservation solution of rat pancreas during ischaemia, a decrease in oxidative stress (ROS), necrosis (HMGB1), and cellular stress pathway (p38 MAPK)activity was observed. Freshly isolated islets had improved function when M101 was injected in the pancreas. Additionally, human pancreases exposed to M101 for 3 hours had an increase in complex 1 mitochondrial activity, as well as activation of AKT activity, a cell survival marker. Insulin secretion was also up-regulated for isolated islets. In summary, these results demonstrate a positive effect of the oxygen carrier M101 on rat and human pancreas during preservation, with an overall improvement in post-isolation islet quality.


Assuntos
Isquemia Fria , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas , Preservação de Órgãos/métodos , Estresse Oxidativo/efeitos dos fármacos , Pâncreas , Animais , Sobrevivência Celular/efeitos dos fármacos , Complexo I de Transporte de Elétrons/metabolismo , Proteína HMGB1/metabolismo , Humanos , Secreção de Insulina/efeitos dos fármacos , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/efeitos dos fármacos , Masculino , Necrose/prevenção & controle , Soluções para Preservação de Órgãos , Oxigênio/metabolismo , Pâncreas/citologia , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Front Physiol ; 10: 1024, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31440170

RESUMO

Skeletal muscle is a main target of insulin action that plays a pivotal role in postprandial glucose disposal. Importantly, skeletal muscle insulin sensitivity relates inversely with pancreatic insulin secretion, which prompted the hypothesis of the existence of a skeletal muscle-pancreas crosstalk mediated through an endocrine factor. The observation that changes in skeletal muscle glucose metabolism are accompanied by altered insulin secretion supports this hypothesis. Meanwhile, a muscle-derived circulating factor affecting in vivo insulin secretion remains elusive. This factor may correspond to peptides/proteins (so called myokines), exosomes and their cargo, and metabolites. We hereby review the most remarkable evidence encouraging the possibility of such inter-organ communication, with special focus on muscle-derived factors that may potentially mediate such skeletal muscle-pancreas crosstalk.

15.
Nat Commun ; 10(1): 3312, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31346174

RESUMO

Compromised function of insulin-secreting pancreatic ß cells is central to the development and progression of Type 2 Diabetes (T2D). However, the mechanisms underlying ß cell failure remain incompletely understood. Here, we report that metabolic stress markedly enhances macroautophagy-independent lysosomal degradation of nascent insulin granules. In different model systems of diabetes including of human origin, stress-induced nascent granule degradation (SINGD) contributes to loss of insulin along with mammalian/mechanistic Target of Rapamycin (mTOR)-dependent suppression of macroautophagy. Expression of Protein Kinase D (PKD), a negative regulator of SINGD, is reduced in diabetic ß cells. Pharmacological activation of PKD counters SINGD and delays the onset of T2D. Conversely, inhibition of PKD exacerbates SINGD, mitigates insulin secretion and accelerates diabetes. Finally, reduced levels of lysosomal tetraspanin CD63 prevent SINGD, leading to increased insulin secretion. Overall, our findings implicate aberrant SINGD in the pathogenesis of diabetes and suggest new therapeutic strategies to prevent ß cell failure.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Lisossomos/metabolismo , Animais , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Humanos , Insulina/química , Secreção de Insulina , Células Secretoras de Insulina/citologia , Macroautofagia , Masculino , Camundongos Endogâmicos C57BL , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
16.
J Vis Exp ; (145)2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-30933067

RESUMO

Regenerative medicine based on cell therapy represents a new hope for curing disease. Current obstacles include proper in vivo validation of the efficiency of the therapy. For transfer to the recipient body, cells often need to be combined with biomaterials, especially hydrogels. However, validation of the efficacy of such a graft requires the right environment, the right hydrogel, and the right recipient site. The omentum might be such a site. Based on the example of islet transplantation, we developed the hOMING (h-Omental Matrix Islet filliNG) technique, which consists of the injection of the graft inside the tissue, in between the omental layers, to improve islet implantation and survival. To achieve this, islets have to be embedded in a hydrogel with a viscosity that enables its injection using an atraumatic needle. Syringes are loaded with a combination of hydrogel and islets. Several injections are performed inside the omental tissue at different entry points, and the deposition of the islet/hydrogel mixture is made along a line. We tested the feasibility of this innovative approach using dextran beads. The beads were well spread throughout the omental tissue, in close proximity to blood vessels. To test the efficacy of the graft, we transplanted islets into diabetic rats and perform a metabolic follow-up over two months. The transplanted islets exhibited a high rate of re-vascularization around and inside islets, and reversed diabetes. The hOMING technique could be applicable for other types of hydrogel or cell therapy, for cells with high metabolic activity.


Assuntos
Transplante das Ilhotas Pancreáticas/métodos , Omento/cirurgia , Animais , Diabetes Mellitus Experimental/terapia , Hidrogéis/farmacologia , Omento/irrigação sanguínea , Ratos
17.
Surg Innov ; 26(3): 280-292, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30920898

RESUMO

PURPOSE: Targeted embolization of gastrointestinal (GI) arteries can modify hormonal production. We aimed to evaluate the impact of the embolization of the gastroduodenal artery (GDA) on the activity of foregut mucosa. METHODS: The GDA's duodenal branch was embolized in 12 Yucatan pigs using 100-300 µm (group A; n = 4) or 300-500 µm (group B; n = 4) microspheres, followed by coiling of the branch. In 4 animals (sham), only saline was injected. The levels of GI hormones (ghrelin, glucose-dependent insulinotropic peptide [GIP], glucagon-like peptide-1 [GLP-1], insulin, peptide YY [PYY], leptin) and the gene expression of sodium-glucose-linked transporter-1 (SGLT-1) and glucose transporter-2 (GLUT-2) were assessed before (T0), 1 hour (T1), 1 month (T2), 3 months (T3), and 6 months (T4) after embolization. RESULTS: In group A, a segmental duodenal stenosis occurred in all cases, which required balloon dilatation. There was a significant drop in the baseline glycemia in group A at T1 and T4 versus sham. Ghrelin was reduced in group A versus baseline and versus group B at T2 and T3 and versus sham at T1 and T3. Insulin was significantly lower in group A versus B at T1 and at T4 but not versus sham. SGLT-1 expression increased in B and sham at T4, while it remained stable in group A. GLUT-2 expression increased in sham at T4 but not in A or B. CONCLUSIONS: GDA embolization induced a decrease in ghrelin production and influenced expression of glucose carriers in the foregut mucosa.


Assuntos
Duodeno , Embolização Terapêutica , Hormônios Gastrointestinais , Síndrome Metabólica , Animais , Masculino , Angiografia Digital , Meios de Contraste/administração & dosagem , Modelos Animais de Doenças , Duodeno/irrigação sanguínea , Duodeno/diagnóstico por imagem , Embolização Terapêutica/métodos , Hormônios Gastrointestinais/metabolismo , Mucosa Intestinal/metabolismo , Síndrome Metabólica/metabolismo , Síndrome Metabólica/prevenção & controle , Suínos , Ácidos Tri-Iodobenzoicos/administração & dosagem
18.
Cell Metab ; 29(2): 348-361.e6, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30318337

RESUMO

Type 1 diabetes is an autoimmune disease initiated by the invasion of pancreatic islets by immune cells that selectively kill the ß cells. We found that rodent and human T lymphocytes release exosomes containing the microRNAs (miRNAs) miR-142-3p, miR-142-5p, and miR-155, which can be transferred in active form to ß cells favoring apoptosis. Inactivation of these miRNAs in recipient ß cells prevents exosome-mediated apoptosis and protects non-obese diabetic (NOD) mice from diabetes development. Islets from protected NOD mice display higher insulin levels, lower insulitis scores, and reduced inflammation. Looking at the mechanisms underlying exosome action, we found that T lymphocyte exosomes trigger apoptosis and the expression of genes involved in chemokine signaling, including Ccl2, Ccl7, and Cxcl10, exclusively in ß cells. The induction of these genes may promote the recruitment of immune cells and exacerbate ß cell death during the autoimmune attack. Our data point to exosomal-miRNA transfer as a communication mode between immune and insulin-secreting cells.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Exossomos/metabolismo , Células Secretoras de Insulina/imunologia , MicroRNAs/fisiologia , Linfócitos T/imunologia , Adulto , Animais , Feminino , Humanos , Células Secretoras de Insulina/citologia , Células Jurkat , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Pessoa de Meia-Idade , Ratos , Ratos Wistar , Linfócitos T/citologia
19.
Oxid Med Cell Longev ; 2018: 7019573, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30363947

RESUMO

AIMS: Oxidative stress (OS) plays a major role in type 2 diabetes and its vascular and hepatic complications, and novel therapeutic approaches include natural antioxidants. Our previous chemical and biological studies demonstrated the antioxidant activities of red cabbage (RC), and here, we aimed to determine the in vivo effects of 2-month long RC consumption using a high-fat/high-fructose model of diabetic rats. RESULTS: This vegetable, associated with lifestyle measurement, was shown to decrease OS and increase vascular endothelial NO synthase expression, ensuring vascular homeostasis. In the liver, RC consumption decreased OS by inhibiting p22phox expression and Nrf2 degradation and increasing catalase activity. It inhibited the activation of SREBP (1c, 2), ChREBP, NF-κB, ERK1/2, PPARγ, and GS and SIRT1 decrease, as observed in diabetic rats. CONCLUSION/INNOVATION: RC consumption led to metabolic profile improvement, together with hepatic function improvements. Although lifestyle changes are not sufficient to prevent diabetic complications, enrichment with RC avoids progression hepatic complications. This antioxidant strategy using RC does not only able to increase antioxidant defense, such as classical antioxidant, but also able to assure a metabolic and energetic balance to reverse complications. Whereas traditional medical therapy failed to reverse NASH in diabetic patients, consumption of RC should be a natural therapy to treat it.


Assuntos
Antioxidantes/uso terapêutico , Brassica/química , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Animais , Disponibilidade Biológica , Biomarcadores/metabolismo , Vasos Sanguíneos/fisiopatologia , Peso Corporal , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Dieta Hiperlipídica , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Jejum/sangue , Frutose , Glucose/metabolismo , Inflamação/patologia , Metabolismo dos Lipídeos , Fígado/metabolismo , Fígado/patologia , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Estresse Oxidativo , Ratos Wistar
20.
Cardiovasc Diabetol ; 17(1): 104, 2018 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-30029691

RESUMO

BACKGROUND: Oxidative stress (OS) plays an important role in type 2 diabetes (T2D) pathogenesis and its complications. New therapies target natural antioxidants as an alternative and/or supplemental strategy to prevent and control them. Our previous chemical and biological studies highlighted the important antioxidant activities of cherries, among other fruits and vegetables, thus we aimed to determine in vivo effects of 2-month long cherry consumption using a high-fat/high-fructose (HFHF) model of diabetic-rats (Lozano et al. in Nutr Metab 13:15, 2016). METHODS: After 2 months of HFHF, male Wistar rats were divided into: HFHF and HFHF enriched in cherry (nutritional approach) or standard diet ND (lifestyle measures) and ND plus cherry during 2 months. Metabolic, lipidic, oxidative parameters were quantified. Tissues (liver, pancreas and vessels) OS were assessed and hepatic (steatosis, fibrosis, inflammation) and vascular (endothelial dysfunction) complications were characterized. RESULTS: T2D was induced after 2 months of HFHF diet, characterized by systemic hyperglycaemia, hyperinsulinemia, glucose intolerance, dyslipidaemia, hyperleptinemia, and oxidative stress associated with endothelial dysfunction and hepatic complications. Cherry consumption for 2 months, in addition to lifestyle measures, in T2D-rats decreased and normalized the systemic disturbances, including oxidative stress complications. Moreover, in the vessel, cherry consumption decreased oxidative stress and increased endothelial nitric oxide (NO) synthase levels, thus increasing NO bioavailability, ensuring vascular homeostasis. In the liver, cherry consumption decreased oxidative stress by inhibiting NADPH oxidase subunit p22phox expression, nuclear factor erythroid-2 related factor 2 (Nrf2) degradation and the formation of reactive oxygen species. It inhibited the activation of sterol regulatory element-binding proteins (1c and 2) and carbohydrate-responsive element-binding protein, and thus decreased steatosis as observed in T2D rats. This led to the improvement of metabolic profiles, together with endothelial and hepatic function improvements. CONCLUSION: Cherry consumption normalized vascular function and controlled hepatic complications, thus reduced the risk of diabetic metabolic disorders. These results demonstrate that a nutritional intervention with a focus on OS could prevent and/or delay the onset of vascular and hepatic complications related to T2D.


Assuntos
Diabetes Mellitus Experimental/dietoterapia , Diabetes Mellitus Tipo 2/dietoterapia , Angiopatias Diabéticas/prevenção & controle , Endotélio Vascular/metabolismo , Metabolismo Energético , Frutas , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Prunus avium , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/etiologia , Angiopatias Diabéticas/sangue , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/fisiopatologia , Dieta Hiperlipídica , Endotélio Vascular/fisiopatologia , Frutose , Insulina/sangue , Leptina/sangue , Lipídeos/sangue , Fígado/patologia , Masculino , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Estresse Oxidativo , Pâncreas/metabolismo , Ratos Wistar , Transdução de Sinais , Fatores de Tempo
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