RESUMO
The mitochondrial uncoupling protein 2 (UCP2) decreases reactive oxygen species (ROS) formation by mitochondria. Our group previously showed that the UCP2 -866A allele was associated with risk of diabetic retinopathy (DR), which is caused by hyperglycemia-induced oxidative stress. To date, it is still unclear if the -866A allele directly affects UCP2 expression in endothelial cells. Thus, we investigated the effect of the A allele on UCP2 promoter activity in HUVECs treated with high glucose (HG) or hydrogen peroxide (H2O2). To quantify UCP2 promoter activity, HUVECs were transfected with pGL3 plasmids containing the UCP2 promoter and the firefly luciferase coding sequence. Experimental groups were: (1) pGL3-866G-transfected cells and (2) pGL3-866A cells, both under normal (4 mM) or HG (25 mM) concentrations for 24 h and 48 h or incubated with H2O2 (0.1 mM) for 1 h. UCP2 promoter activity was monitored by Luminescent Dual-luciferase Assay. HG induced an upregulation of UCP2 promoter activity in PGL3-866G cells after 24 h of treatment (P = 0.027), but not after 48 h. Compared to pGL3-866G cells, pGL3-866A cells seems to have reduced UCP2 promoter activity following 24 h and 48 h of normal glucose treatment (P = 0.087 and P = 0.022). After HG treatment, pGL3-866A cells had more marked UCP2 downregulation (24 h: - 3.2-folds, P < 0.001; and 48 h: - 2.5-folds, P < 0.001 vs. G cells). Both pGL3-866G and pGL3-866A cells treated with H2O2 showed a â 4-fold increase in UCP2 promoter activity (both P < 0.001). The -866A allele modifies UCP2 promoter activity in HUVECs under HG treatment but not in the H2O2 condition.
Assuntos
Alelos , Genótipo , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Proteína Desacopladora 2/genética , Genes Reporter , Glucose/metabolismo , Glucose/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Estresse OxidativoRESUMO
Pancreatic islet transplantation is an established treatment to restore insulin independence in type 1 diabetic patients. Its success rates have increased lately based on improvements in immunosuppressive therapies and on islet isolation and culture. It is known that the quality and quantity of viable transplanted islets are crucial for the achievement of insulin independence and some studies have shown that a significant number of islets are lost during culture time. Thus, in an effort to improve islet yield during culture period, researchers have tested a variety of additives in culture media as well as alternative culture devices, such as scaffolds. However, due to the use of different categories of additives or devices, it is difficult to draw a conclusion on the benefits of these strategies. Therefore, the aim of this systematic review was to summarize the results of studies that described the use of medium additives, scaffolds or extracellular matrix (ECM) components during human pancreatic islets culture. PubMed and Embase repositories were searched. Of 5083 articles retrieved, a total of 37 articles fulfilled the eligibility criteria and were included in the review. After data extraction, articles were grouped as follows: 1) "antiapoptotic/anti-inflammatory/antioxidant," 2) "hormone," 3) "sulphonylureas," 4) "serum supplements," and 5) "scaffolds or ECM components." The effects of the reviewed additives, ECM or scaffolds on islet viability, apoptosis and function (glucose-stimulated insulin secretion - GSIS) were heterogeneous, making any major conclusion hard to sustain. Overall, some "antiapoptotic/anti-inflammatory/antioxidant" additives decreased apoptosis and improved GSIS. Moreover, islet culture with ECM components or scaffolds increased GSIS. More studies are needed to define the real impact of these strategies in improving islet transplantation outcomes.
Assuntos
Matriz Extracelular/metabolismo , Ilhotas Pancreáticas/citologia , Técnicas de Cultura de Tecidos , Alicerces Teciduais , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/terapia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/imunologia , Humanos , Hipoglicemiantes/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Transplante das Ilhotas Pancreáticas/efeitos adversos , Transplante das Ilhotas Pancreáticas/imunologia , Transplante das Ilhotas Pancreáticas/tendências , Compostos de Sulfonilureia/farmacologia , Técnicas de Cultura de Tecidos/tendênciasRESUMO
The maintenance of viable and functional pancreatic islets is crucial for successful islet transplantation from brain-dead donors. To overcome islet quality loss during culture, some studies have co-cultured islets with mesenchymal stem/stromal cells (MSC). However, it is still uncertain if MSC-secreted factors are enough to improve islet quality or if a physical contact between MSCs and islets is needed. Therefore, we performed a systematic review and meta-analysis to clarify the effect of different culture contact systems of islets with MSCs on viability and insulin secretion outcomes. Pubmed and Embase were searched. Twenty studies fulfilled the eligibility criteria and were included in the qualitative synthesis and/or meta-analysis. For both outcomes, pooled weighted mean differences (WMD) between islet cultured alone (control group) and the co-culture condition were calculated. Viability mean was higher in islets co-cultured with MSCs compared with islet cultured alone [WMD = 18.08 (95% CI 12.59-23.57)]. The improvement in viability was higher in islets co-cultured in indirect or mixed contact with MSCs than in direct physical contact (P <0.001). Moreover, the mean of insulin stimulation index (ISI) was higher in islets from co-culture condition compared with islet cultured alone [WMD = 0.83 (95% CI 0.54-1.13)], independently of contact system. Results from the studies that were analyzed only qualitatively are in accordance with meta-analysis data. Co-culture of islets with MSCs has the potential for protecting islets from injury during culture period. Moreover, culture time appears to influence the beneficial effect of different methods of co-culture on viability and function of islets.
Assuntos
Técnicas de Cocultura , Insulina/metabolismo , Ilhotas Pancreáticas/citologia , Células-Tronco Mesenquimais/citologia , Animais , Humanos , Secreção de Insulina , Ilhotas Pancreáticas/metabolismoRESUMO
INTRODUCTION: Uncoupling protein 2 (UCP2) reduces production of reactive oxygen species (ROS) by mitochondria. ROS overproduction is one of the major contributors to the pathogenesis of chronic diabetic complications, such as diabetic kidney disease (DKD). Thus, deleterious polymorphisms in the UCP2 gene are candidate risk factors for DKD. In this study, we investigated whether UCP2 -866G/A, Ala55Val and Ins/Del polymorphisms were associated with DKD in patients with type 2 diabetes mellitus (T2DM), and whether they had an effect on UCP2 gene expression in human kidney tissue biopsies. MATERIALS AND METHODS: In a case-control study, frequencies of the UCP2 -866G/A, Ala55Val and Ins/Del polymorphisms as well as frequencies of the haplotypes constituted by them were analyzed in 287 T2DM patients with DKD and 281 T2DM patients without this complication. In a cross-sectional study, UCP2 gene expression was evaluated in 42 kidney biopsy samples stratified according to the presence of the UCP2 mutated -866A/55Val/Ins haplotype. RESULTS: In the T2DM group, multivariate logistic regression analysis showed that the -866A/55Val/Ins haplotype was an independent risk factor for DKD (OR = 2.136, 95% CI 1.036-4.404), although neither genotype nor allele frequencies of the individual polymorphisms differed between case and control groups. Interestingly, T2DM patients carrying the mutated haplotype showed decreased estimated glomerular filtration rate (eGFR) when compared to subjects with the reference haplotype (adjusted P= 0.035). In kidney biopsy samples, UCP2 expression was significantly decreased in UCP2 mutated haplotype carriers when compared to kidneys from patients with the reference haplotype (0.32 ± 1.20 vs. 1.85 ± 1.16 n fold change; adjusted P< 0.000001). DISCUSSION: Data reported here suggest that the UCP2 -866A/55Val/Ins haplotype is associated with an increased risk for DKD and with a lower eGFR in T2DM patients. Furthermore, this mutated haplotype was associated with decreased UCP2 gene expression in human kidneys.
Assuntos
Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Regulação da Expressão Gênica , Taxa de Filtração Glomerular/genética , Canais Iônicos , Rim/metabolismo , Proteínas Mitocondriais , Mutação de Sentido Incorreto , Adulto , Substituição de Aminoácidos , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Feminino , Humanos , Canais Iônicos/biossíntese , Canais Iônicos/genética , Rim/patologia , Masculino , Proteínas Mitocondriais/biossíntese , Proteínas Mitocondriais/genética , Proteína Desacopladora 2RESUMO
Type 1 diabetes mellitus (T1DM) is a chronic, progressive autoimmune disease characterized by metabolic decompensation often leading to dehydration and ketoacidosis. Viral agents seem to play an important role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, the enterovirus family has been consistently associated with the onset of T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The Toll-like receptor 3 (TLR3) gene codes for an endoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, plays an important role in the innate immune response triggered by viral infection. Binding of dsRNA to the TLR3 triggers the release of proinflammatory cytokines, such as interferons, which exhibit potent antiviral action; thus, protecting uninfected cells and inducing apoptosis of infected ones. Therefore, the TLR3 gene is a good candidate for the development of T1DM. Within this context, the objective of the present review was to address the role of the TLR3 gene in the development of T1DM.
Assuntos
Diabetes Mellitus Tipo 1/genética , RNA de Cadeia Dupla/metabolismo , Receptor 3 Toll-Like/genética , Animais , Citocinas/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/virologia , Enterovirus/imunologia , Enterovirus/fisiologia , Humanos , Imunidade Inata/fisiologia , Inflamação/metabolismo , Células Secretoras de Insulina/metabolismo , Transdução de Sinais/fisiologia , Receptor 3 Toll-Like/metabolismo , Replicação Viral/genética , Replicação Viral/imunologiaRESUMO
Type 1 diabetes mellitus (T1DM) is a chronic, progressive autoimmune disease characterized by metabolic decompensation often leading to dehydration and ketoacidosis. Viral agents seem to play an important role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, the enterovirus family has been consistently associated with the onset of T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The Toll-like receptor 3 (TLR3) gene codes for an endoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, plays an important role in the innate immune response triggered by viral infection. Binding of dsRNA to the TLR3 triggers the release of proinflammatory cytokines, such as interferons, which exhibit potent antiviral action; thus, protecting uninfected cells and inducing apoptosis of infected ones. Therefore, the TLR3 gene is a good candidate for the development of T1DM. Within this context, the objective of the present review was to address the role of the TLR3 gene in the development of T1DM. Arch Endocrinol Metab. 2015;59(1):4-12.
Assuntos
Animais , Humanos , Diabetes Mellitus Tipo 1/genética , RNA de Cadeia Dupla/metabolismo , /genética , Citocinas/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/virologia , Enterovirus/imunologia , Enterovirus/fisiologia , Imunidade Inata/fisiologia , Inflamação/metabolismo , Células Secretoras de Insulina/metabolismo , Transdução de Sinais/fisiologia , /metabolismo , Replicação Viral/genética , Replicação Viral/imunologiaRESUMO
This paper describes a case-control study and a meta-analysis performed to evaluate if the following polymorphisms are associated with presence of obesity: -3826A/G (UCP1); -866G/A, Ala55Val and Ins/Del (UCP2) and -55C/T (UCP3). The case-control study enrolled 282 obese and 483 non-obese patients with type 2 diabetes. A literature search was made to identify all studies that evaluated associations between UCP1-3 polymorphisms and obesity. In the case-control study the distributions of the UCP variants did not differ between obese and non-obese groups (P > 0.05). Forty-seven studies were eligible for the meta-analysis and the results showed that the UCP2 -866G/A and UCP3 -55C/T polymorphisms were associated with protection to obesity in Europeans (OR = 0.89, 95% CI 0.82-0.97 and OR = 0.88, 95% CI 0.80-0.97, respectively). The UCP2 Ala55 val polymorphism was associated with obesity in Asians (OR = 1.61, 95% CI 1.13-2.30). The UCP2 Ins/Del polymorphism was associated with obesity mainly in Europeans (OR = 1.19, 95% CI 1.00-1.42). There was no significant association of the UCP1 -3826A/G polymorphism with obesity. In our case-control study we were not able to demonstrate any association between UCP polymorphisms and obesity in T2DM patients; however, in the meta-analysis we detected a significant association of UCP2 -866G/A, Ins/Del, Ala55Val and UCP3 -55C/T polymorphisms with obesity.
Assuntos
Canais Iônicos/genética , Proteínas Mitocondriais/genética , Obesidade/genética , Polimorfismo de Nucleotídeo Único , Idoso , Povo Asiático/genética , Índice de Massa Corporal , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/genética , Feminino , Predisposição Genética para Doença , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Proteína Desacopladora 1 , Proteína Desacopladora 2 , Proteína Desacopladora 3 , População Branca/genéticaRESUMO
Type 1 diabetes mellitus (T1DM) is a chronic, progressive, autoimmune disease characterized by metabolic decompensation frequently leading to dehydration and ketoacidosis. Viral pathogens seem to play a major role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, enteroviruses have been consistently associated with T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The IFIH1 gene encodes a cytoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, playing a role in the innate immune response triggered by viral infection. Binding of dsRNA to this PRR triggers the release of proinflammatory cytokines, such as interferons (IFNs), which exhibit potent antiviral activity, protecting uninfected cells and inducing apoptosis of infected cells. The IFIH1 gene appears to play a major role in the development of some autoimmune diseases, and it is, therefore, a candidate gene for T1DM. Within this context, the objective of the present review was to address the role of IFIH1 in the development of T1DM.
O diabetes melito tipo 1 (T1DM) é uma doença autoimune crônica e progressiva caracterizada por descompensações metabólicas frequentemente acompanhadas por desidratação e cetoacidose. Os agentes virais parecem ter um papel importante no desencadeamento da destruição autoimune que leva ao desenvolvimento do T1DM. Entre as cepas virais estudadas até agora, a família dos enterovírus foi consistentemente associada ao surgimento da doença em humanos. Um dos mediadores do dano viral é o RNA fita dupla (RNAfd) gerado durante a replicação e transcrição de RNA e DNA viral. O gene IFIH1 codifica um receptor citoplasmático pertencente à família dos pattern-recognition receptors (PRRs) que reconhece o RNAfd, tendo um papel importante na resposta imune inata desencadeada por infecção viral. A ligação do RNAfd a essa PRR desencadeia a liberação de citocinas pró-inflamatórias como interferons (IFNs), os quais exibem uma potente ação antiviral e têm como objetivo proteger as células não infectadas e induzir apoptose naquelas já contaminadas. O gene IFIH1 parece ter uma participação importante no desenvolvimento de algumas doenças autoimunes. Por isso, esse gene é um candidato ao desenvolvimento do T1DM. Dentro desse contexto, o objetivo da presente revisão foi abordar o papel do IFIH1 no desenvolvimento do T1DM.
Assuntos
Humanos , RNA Helicases DEAD-box/fisiologia , Diabetes Mellitus Tipo 1/genética , Imunidade Inata/genética , RNA Helicases DEAD-box/imunologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/virologia , Predisposição Genética para Doença , Polimorfismo Genético , Fatores de RiscoRESUMO
Type 1 diabetes mellitus (T1DM) is a chronic, progressive, autoimmune disease characterized by metabolic decompensation frequently leading to dehydration and ketoacidosis. Viral pathogens seem to play a major role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, enteroviruses have been consistently associated with T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The IFIH1 gene encodes a cytoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, playing a role in the innate immune response triggered by viral infection. Binding of dsRNA to this PRR triggers the release of proinflammatory cytokines, such as interferons (IFNs), which exhibit potent antiviral activity, protecting uninfected cells and inducing apoptosis of infected cells. The IFIH1 gene appears to play a major role in the development of some autoimmune diseases, and it is, therefore, a candidate gene for T1DM. Within this context, the objective of the present review was to address the role of IFIH1 in the development of T1DM.