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/metabolismoRESUMO
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/metabolismoRESUMO
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 & dosagemRESUMO
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 TempoRESUMO
PURPOSE: Individuals with metabolic syndrome (MS) show several metabolic abnormalities including insulin resistance, dyslipidaemia, and oxidative stress (OS). Diet is one of the factors influencing the development of MS, and current nutritional advice emphasises the benefits of fruit and vegetable consumption. Here, we assessed the effects of naturally occurring antioxidants, red wine polyphenols (RWPs), on MS and OS. METHODS: Wistar rats (n = 20) weighing 200-220 g received a high-fat diet (HFD) for 2 months before they were divided into two groups that received either HFD only or HFD plus 50 mg/kg RWPs in their drinking water for an additional 2 months. A control group (n = 10) received a normal diet (ND) for 4 months. RESULTS: Rats receiving HFD increased body weight over 20 % throughout the duration of the study. They also showed increased blood levels of C-peptide, glucose, lipid peroxides, and oxidised proteins. In addition, the HFD increased OS in hepatic, pancreatic, and vascular tissues, as well as induced pancreatic islet cell hyperplasia and hepatic steatosis. Addition of RWPs to the HFD attenuated these effects on plasma and tissue OS and on islet cell hyperplasia. However, RWPs had no effect on blood glucose levels or hepatic steatosis. CONCLUSIONS: RWPs showed an antioxidant mechanism of action against MS. This result will inform future animal studies exploring the metabolic effects of RWPs in more detail. In addition, these findings support the use of antioxidants as adjunctive nutritional treatments for patients with diabetes.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Síndrome Metabólica/dietoterapia , Polifenóis/farmacologia , Vinho , Animais , Antioxidantes/farmacologia , Glicemia/metabolismo , Peptídeo C/sangue , Modelos Animais de Doenças , Peróxidos Lipídicos/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Síndrome Metabólica/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
BACKGROUND: The aim was to identify fall predictors in elderly suffering from chronic pain (CP) and to test their applicability among patients with other chronic conditions. METHODS: 1,379 non-institutionalized patients aged 65 years and older who were suffering from CP (S.AGE CP sub-cohort) were monitored every 6 months for 1 year. Socio-demographic, clinical and pain data and medication use were assessed at baseline for the association with falls in the following year. Falls were assessed retrospectively at each study visit. Logistic regression analyses were performed to identify fall predictors. The derived model was applied to two additional S.AGE sub-cohorts: atrial fibrillation (AF) (n = 1,072) and type-2 diabetes mellitus (T2DM) (n = 983). RESULTS: Four factors predicted falls in the CP sub-cohort: fall history (OR: 4.03, 95 % CI 2.79-5.82), dependency in daily activities (OR: 1.81, 95 % CI 1.27-2.59), age ≥75 (OR: 1.53, 95 % CI 1.04-2.25) and living alone (OR: 1.73, 95 % CI 1.24-2.41) (Area Under the Curve: AUC = 0.71, 95 % CI 0.67-0.75). These factors were relevant in AF (AUC = 0.71, 95 % CI 0.66-0.75) and T2DM (AUC = 0.67, 95 % CI 0.59-0.73) sub-cohorts. Fall predicted probability in CP, AF and T2DM sub-cohorts increased from 7, 7 and 6 % in patients with no risk factors to 59, 66 and 45 % respectively, in those with the four predictors. Fall history was the strongest predictor in the three sub-cohorts. CONCLUSION: Fall history, dependency in daily activities, age ≥75 and living alone are independent fall predictors in CP, AF and T2DM patients.
Assuntos
Acidentes por Quedas , Fibrilação Atrial/epidemiologia , Dor Crônica , Diabetes Mellitus Tipo 2/epidemiologia , Acidentes por Quedas/prevenção & controle , Acidentes por Quedas/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Causalidade , Dor Crônica/diagnóstico , Dor Crônica/epidemiologia , Feminino , Seguimentos , França/epidemiologia , Avaliação Geriátrica/métodos , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores de RiscoRESUMO
OBJECTIVE: Describe the consequences of dextropropoxyphene (DXP) market withdrawal on analgesic prescriptions and on the quality of therapeutic management of chronic pain. PATIENTS AND METHODS: From a cohort of non-institutionalised elderly patients with chronic pain recruited by general practitioners, we selected patients who were treated with DXP daily for at least 6 months just prior to DXP market withdrawal and who had an evaluation of pain and its impact on daily activities before and after DXP withdrawal. RESULTS: One hundred three patients took DXP daily for chronic pain. Immediately after DXP market withdrawal, 42 (40.8%), 55 (53.4%) and 3 (2.9%) patients were treated with step 1, 2 and 3 analgesics, respectively, and 3 patients (2.9%) were no longer receiving any analgesic medication. Among the 55 patients who continued on step 2 analgesics, 37 were treated with tramadol, 14 with codeine and 9 with opium. Pain intensity and the impact of pain on daily activities remained stable. CONCLUSION: DXP market withdrawal had no consequences on the intensity or impact of chronic pain in elderly patients.
Assuntos
Analgésicos Opioides/uso terapêutico , Dor Crônica/tratamento farmacológico , Dextropropoxifeno/uso terapêutico , Retirada de Medicamento Baseada em Segurança , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Analgésicos/uso terapêutico , Dor Crônica/fisiopatologia , Estudos de Coortes , Feminino , Humanos , Masculino , Estudos ProspectivosRESUMO
The primary objective of the S.AGES cohort is to describe the real-life therapeutic care of elderly patients. Patients and methods. This is a prospective observational cohort study of 3 700 non-institutionalized patients over the age of 65 years with either type 2 diabetes mellitus (T2DM), chronic pain or atrial fibrillation (AF) recruited by French general practitioners (GPs). Follow-up is planned for 3 years. Baseline characteristics. In the chronic pain sub-cohort, 33% of patients are treated with only grade 1 analgesics, 29% with grade 2 analgesics and 3% with grade 3 analgesics, and 22% have no pain treatment. In the T2DM sub-cohort, 61% of patients have well-controlled diabetes (Hb1c<7%) and 18% are treated with insulin. In the AF sub-cohort, 65% of patients have a CHADS2 score greater than 2, 77% are treated with oral anticoagulants, 17% with platelet inhibitors, 40% with antiarrhythmic drugs and 56% with rate slowing medications. Conclusion. The S.AGES cohort presents a unique opportunity to clarify the real-life therapeutic management of ambulatory elderly subjects and will help to identify the factors associated with the occurrence of major clinical events.
Assuntos
Assistência Ambulatorial/estatística & dados numéricos , Fibrilação Atrial/terapia , Dor Crônica/terapia , Diabetes Mellitus Tipo 2/terapia , Idoso , Idoso de 80 Anos ou mais , Assistência Ambulatorial/normas , Fibrilação Atrial/epidemiologia , Dor Crônica/epidemiologia , Estudos de Coortes , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , França/epidemiologia , Humanos , Masculino , Características de Residência/estatística & dados numéricosRESUMO
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 , LipídeosRESUMO
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 , EritrócitosRESUMO
BACKGROUND: Insulin degludec is a new basal insulin that forms soluble multihexamer assemblies after subcutaneous injection, resulting in an ultra-long action profile. This study aimed to assess efficacy and safety of insulin degludec injected once a day or three times a week compared with insulin glargine once a day in insulin-naive people with type 2 diabetes, who were inadequately controlled with oral antidiabetic drugs. METHODS: In this 16-week, randomised, open-label, parallel-group phase 2 trial, participants aged 1875 years with type 2 diabetes and glycosylated haemoglobin (HbA(1C)) of 7·011·0% were enrolled and treated at 28 clinical sites in Canada, India, South Africa, and the USA. Participants were randomly allocated in a 1:1:1:1 ratio by computer-generated block randomisation to receive insulin degludec either once a day or three times a week or insulin glargine once a day, all in combination with metformin. Investigators were masked to data until database release. The primary outcome was HbA(1C) after 16 weeks of treatment. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00611884. FINDINGS: Of 367 patients screened, 245 were eligible for inclusion. 62 participants were randomly allocated to receive insulin degludec three times a week (starting dose 20 U per injection [1 U=9 nmol]), 60 to receive insulin degludec once a day (starting dose 10 U [1 U=6 nmol]; group A), 61 to receive insulin degludec once a day (starting dose 10 U [1 U=9 nmol]; group B), and 62 to receive insulin glargine (starting dose 10 U [1 U=6 nmol]) once a day. At study end, mean HbA(1C) levels were much the same across treatment groups, at 7·3% (SD 1·1), 7·4% (1·0), 7·5% (1·1), and 7·2% (0·9), respectively. Estimated mean HbA(1C) treatment differences from insulin degludec by comparison with insulin glargine were 0·08% (95% CI 0·23 to 0·40) for the three dose per week schedule, 0·17% (0·15 to 0·48) for group A, and 0·28% (0·04 to 0·59) for group B. Few participants had hypoglycaemia and the number of adverse events was much the same across groups, with no apparent treatment-specific pattern. INTERPRETATION: Insulin degludec provides comparable glycaemic control to insulin glargine without additional adverse events and might reduce dosing frequency due to its ultra-long action profile. FUNDING: Novo Nordisk.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Insulina de Ação Prolongada/administração & dosagem , Insulina/análogos & derivados , Adolescente , Adulto , Idoso , Glicemia/análise , Diabetes Mellitus Tipo 2/sangue , Esquema de Medicação , Feminino , Hemoglobinas Glicadas/análise , Humanos , Injeções Subcutâneas , Insulina/administração & dosagem , Insulina Glargina , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
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/metabolismoRESUMO
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/etiologiaRESUMO
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/genéticaRESUMO
Chromogranin A is present in secretion granules of nerve, endocrine and immune cells and is a precursor of several peptides with antibacterial and antifungal properties at micromolar concentrations.Our aim in this prospective, double blind study, was to determine the expression of chromogranin A and its peptides at protein level in saliva of type 2 diabetic patients and thereby to obtain a new non-invasive diagnostic means for the future.Saliva was taken from 30 type 2 diabetic patients and 30 healthy individuals at the same time interval in the morning without any oral stimuli. Circadianic periodics in protein productions have been avoided. The presence of chromogranin A and its derived peptides was determined in whole saliva, after centrifugation at 40C for 12 min at 14 000 rpm, by SDS-PAGE electrophoresis and Immunoblotting (Western Blot). To ensure same protein concentrations Bradford protein quantification assay has been performed before.For the first time, we have determined an overexpression of chromogranin A in saliva of diabetic patients in 100% of the individuals. Chromogranin A, a circulating biomarker for epithelial tumours, is also overexpressed in saliva of type 2 diabetic patients. To confirm our results, more studies with a large amount of patients is necessary.
Assuntos
Cromogranina A/metabolismo , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/metabolismo , Saliva/metabolismo , Biomarcadores/metabolismo , Western Blotting , Método Duplo-Cego , Eletroforese em Gel de Poliacrilamida , Humanos , Valor Preditivo dos TestesRESUMO
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 , ViscosidadeRESUMO
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 RiscoRESUMO
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 SexuaisRESUMO
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 DemênciaRESUMO
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.