RESUMO
Introduction: We reported that Ca2+-independent phospholipase A2ß (iPLA2ß)-derived lipids (iDLs) contribute to type 1 diabetes (T1D) onset. As CD4+ and CD8+ T cells are critical in promoting ß-cell death, we tested the hypothesis that iDL signaling from these cells participates in T1D development. Methods: CD4+ and CD8+ T cells from wild-type non-obese diabetic (NOD) and NOD.iPLA2ß+/- (NOD.HET) mice were administered in different combinations to immunodeficient NOD.scid. Results: In mice receiving only NOD T cells, T1D onset was rapid (5 weeks), incidence 100% by 20 weeks, and islets absent. In contrast, onset was delayed 1 week and incidence reduced 40%-50% in mice receiving combinations that included NOD.HET T cells. Consistently, islets from these non-diabetic mice were devoid of infiltrate and contained insulin-positive ß-cells. Reduced iPLA2ß led to decreased production of proinflammatory lipids from CD4+ T cells including prostaglandins and dihydroxyeicosatrienoic acids (DHETs), products of soluble epoxide hydrolase (sEH), and inhibition of their signaling decreased (by 82%) IFNγ+CD4+ cells abundance. However, only DHETs production was reduced from CD8+ T cells and was accompanied by decreases in sEH and granzyme B. Discussion: These findings suggest that differential select iDL signaling in CD4+ and CD8+ T cells contributes to T1D development, and that therapeutics targeting such signaling might be considered to counter T1D.
Assuntos
Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Diabetes Mellitus Tipo 1 , Camundongos Endogâmicos NOD , Transdução de Sinais , Animais , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Camundongos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/imunologia , Fosfolipases A2 do Grupo VI/metabolismo , Fosfolipases A2 do Grupo VI/genética , Metabolismo dos Lipídeos , Camundongos SCID , FemininoRESUMO
This study aimed to characterize the role of female sex in the pathogenesis of diabetic retinopathy. In the retinae of female Ins2Akita-diabetic mice (F-IA), ovariectomized female Ins2Akita-diabetic mice (F-IA/OVX), male Ins2Akita-diabetic mice (M-IA), and female STZ-diabetic mice (F-STZ), the formation of reactive metabolites and post-translational modifications, damage to the neurovascular unit, and expression of cellular stress response genes were analyzed. Compared to the male diabetic retina, the concentrations of the glycation adduct fructosyl-lysine, the Maillard product 3-deoxyglucosone, and the reactive metabolite methylglyoxal were significantly reduced in females. In females, there was also less evidence of diabetic damage to the neurovascular unit, as shown by decreased pericyte loss and reduced microglial activation. In the male diabetic retina, the expression of several members of the crystallin gene family (Cryab, Cryaa, Crybb2, Crybb1, and Cryba4) was increased. Clinical data from type 1 diabetic females showed that premenopausal women had a significantly lower prevalence of diabetic retinopathy compared to postmenopausal women stratified for disease duration and glycemic control. These data emphasize the importance of estradiol in protecting the diabetic retina and highlight the pathogenic relevance of sex in diabetic retinopathy.
Assuntos
Diabetes Mellitus Experimental , Retinopatia Diabética , Retina , Caracteres Sexuais , Animais , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Feminino , Masculino , Camundongos , Diabetes Mellitus Experimental/metabolismo , Retina/metabolismo , Retina/patologia , Humanos , Fatores Sexuais , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/patologia , Modelos Animais de DoençasRESUMO
Type 1 Diabetes (T1D) is a chronic metabolic disease resulting from insulin deficiency due to autoimmune loss of pancreatic ß cells. In addition to ß cell destruction, it is now accepted that ß cell stress and dysfunction, such as senescence, plays a crucial role in the development of the disease. Accumulation of senescent ß cells occurs during development of T1D in humans and contributes to the progression of T1D in the nonobese diabetic (NOD) mouse model. Senescent ß cells are thought to exacerbate the inflammatory response within the islets by production and secretion of senescence-associated secretory phenotype (SASP). Extracellular vesicles (EVs) from ß cells have been shown to carry protein and microRNAs (miRNAs), influencing cellular signaling and may contribute to the development of T1D but it remains to be addressed how senescence impacts ß cell EV cargo. In this minireview, we discuss emerging evidence that EV cargo proteins and miRNAs associated with senescence could contribute to the development of T1D and could suggest potential biomarkers and therapeutic targets for the regulation of SASP and elimination of senescent ß cells in T1D. Future investigation exploring the intricate relationship between ß cell senescence, EVs and miRNAs could pave the way for the development of novel diagnostic techniques and therapeutic interventions.
Assuntos
Senescência Celular , Diabetes Mellitus Tipo 1 , Vesículas Extracelulares , Células Secretoras de Insulina , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Humanos , Vesículas Extracelulares/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Animais , MicroRNAs/metabolismo , MicroRNAs/genética , Fenótipo Secretor Associado à SenescênciaRESUMO
Nutritional status assessment, including amino acids, carnitine, and acylcarnitine profile, is an important component of diabetes care management, influencing growth and metabolic regulation. A designed case-control research included 100 Egyptian participants (50 T1DM and 50 healthy controls) aged 6 to 18 years old. The participants' nutritional status was assessed using the Body Mass Index (BMI) Z-score. Extended metabolic screening (EMS) was performed using a high-performance liquid chromatography-electrospray ionization-mass spectroscopy system to evaluate the levels of 14 amino acids, free carnitine, and 27 carnitine esters. T1DM children had considerably lower anthropometric Z-scores than the control group, with 16% undernutrition and 32% short stature. Total aromatic amino acids, phenylalanine, phenylalanine/tyrosine ratio, proline, arginine, leucine, isoleucine, free carnitine, and carnitine esters levels were considerably lower in the diabetic group, suggesting an altered amino acid and carnitine metabolism in type 1 diabetes. BMI Z-score showed a significant positive correlation with Leucine, Isoleucine, Phenylalanine, Citrulline, Tyrosine, Arginine, Proline, free carnitine, and some carnitine esters (Acetylcarnitine, Hydroxy-Isovalerylcarnitine, Hexanoylcarnitine, Methylglutarylcarnitine, Dodecanoylcarnitine, Tetradecanoylcarnitine, and Hexadecanoylcarnitine). HbA1c% had a significant negative correlation with Total aromatic amino acids, Branched-chain amino acid/Total aromatic amino acids ratio, Glutamic Acid, Citrulline, Tyrosine, Arginine, Proline, and certain carnitine esters (Propionylcarnitine, Methylglutarylcarnitine, Decanoylcarnitine, Octadecanoylcarnitine and Octadecenoylcarnitine), suggest that dysregulated amino acid and carnitine metabolism may be negatively affect the glycaemic control in children with TIDM. In conclusion, regular nutritional assessments including EMS of T1DM patients are critical in terms of diet quality and protein content for improved growth and glycemic management.
Assuntos
Aminoácidos , Carnitina , Diabetes Mellitus Tipo 1 , Estado Nutricional , Humanos , Criança , Masculino , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Adolescente , Egito , Carnitina/análogos & derivados , Carnitina/metabolismo , Carnitina/sangue , Estudos de Casos e Controles , Aminoácidos/metabolismo , Índice de Massa CorporalRESUMO
Enhancement of Connexin43 (Cx43) and ferroptosis are respectively associated with the exacerbation of myocardial ischemia-reperfusion injury (MIRI) in diabetes. Myocardial vulnerability to ischemic insult has been shown to vary during early and later phases of diabetes in experimental settings. Whether or not Connexin43 (Cx43) and ferroptosis interplay during MIRI in diabetes is unknown. We, thus, aimed to investigate whether or not the content of myocardial Cx43 may be attributable to myocardial vulnerability to MIRI at different stages of diabetes and also to explore the potential interplay between Cx43 and ferroptosis in this pathology. Age-matched control and subgroups of Streptozotocin-induced diabetic mice were subjected to MIRI induced by 30 minutes coronary artery occlusion and 2 hours reperfusion respectively at 1, 2 and 5 weeks of diabetes. Rat cardiac H9C2 cells were exposed to high glucose (HG) for 48h in the absence or presence of Cx43 gene knockdown followed by hypoxia/reoxygenation (HR) respectively for 6 and 12 hours. Post-ischemic myocardial infarct size was reduced in 1 and 2 weeks DM mice concomitant with enhanced GPX4 and reduced cardiac Cx43 and ferroptosis as compared to control. By contrast, cardiac GPX4 was significantly reduced while Cx43 increased at DM 5 weeks (D5w) which was correspondent to significant increases in ferroptosis and myocardial infarction. Post-ischemic cardiac function was improved in 1 and 2 weeks but worsened in 5w DM mice as compared with non-diabetic control. GAP19 (Cx43 inhibitor) significantly attenuated ferroptosis and reduced myocardial infarction in D5w mice. Erastin (ferroptosis activator) reversed the cardioprotective effect of GAP19. In vitro, HR significantly reduced cell viability accompanied with reduced GPX4 but elevated Cx43 expression, MDA production and ferroptosis. Cx43 gene knockdown in H9C2 resulted in a significant increase in GPX4, reduction in MDA and ferroptosis, and subsequently reduced post-hypoxic cell viability. The beneficial effects of Cx43 gene knock-down was minified or eliminated by Erastin. It is concluded that Cx43 overexpression exacerbates MIRI under diabetic conditions via promoting ferroptosis, while its down-regulation at early state of diabetes is attributable to enhanced myocardial tolerance to MIRI.
Assuntos
Conexina 43 , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Ferroptose , Traumatismo por Reperfusão Miocárdica , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Animais , Ferroptose/genética , Conexina 43/metabolismo , Conexina 43/genética , Camundongos , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/genética , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Ratos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/genética , Masculino , Técnicas de Silenciamento de Genes , Humanos , Linhagem Celular , Miocárdio/patologia , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Infarto do Miocárdio/patologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismoRESUMO
The carotid body (CB) senses changes in arterial O2 partial pressure (pO2) and glucose levels; therefore, it is key for the detection of hypoxia and hypoglycemia. The CB has been suggested to detect pO2 through an increase in reactive oxygen species (ROS) in the mitochondria. However, the mechanism protecting the chemoreceptor cells and their mitochondria from ROS and hyperglycemia is poorly understood. Here we measured glutathione levels in CB mitochondria of control and in streptozotocin (STZ)-induced type 1 diabetic male Wistar rats. We found a dramatic reduction in total glutathione from 11.45 ± 1.30 µmol/mg protein in control rats to 1.45 ± 0.31 µmol/mg protein in diabetic rats. However, the ratio of reduced to oxidized glutathione, a measure of the redox index, was increased in diabetic rats compared to controls. We conclude that the mitochondria of CB chemoreceptor cells in type 1 diabetic male Wistar rats were likely under glutathione-reducing stress.
Assuntos
Corpo Carotídeo , Diabetes Mellitus Experimental , Glutationa , Mitocôndrias , Ratos Wistar , Animais , Masculino , Corpo Carotídeo/metabolismo , Ratos , Mitocôndrias/metabolismo , Glutationa/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , OxirreduçãoRESUMO
Background: Endogenous insulin supplementation is essential for individuals with type 1 diabetes (T1D). However, current treatments, including pancreas transplantation, insulin injections, and oral medications, have significant limitations. The development of engineered cells that can secrete endogenous insulin offers a promising new therapeutic strategy for type 1 diabetes (T1D). This approach could potentially circumvent autoimmune responses associated with the transplantation of differentiated ß-cells or systemic delivery of viral vectors. Methods: We utilized CRISPR/Cas9 gene editing coupled with homology-directed repair (HDR) to precisely integrate a promoter-free EMCVIRES-insulin cassette into the 3' untranslated region (UTR) of the GAPDH gene in human HEK-293T cells. Subsequently quantified insulin expression levels in these engineered cells, the viability and functionality of the engineered cells when seeded on different cell vectors (GelMA and Cytopore I) were also assessed. Finally, we investigated the therapeutic potential of EMCVIRES-based insulin secretion circuits in reversing Hyperglycaemia in T1D mice. Result: Our results demonstrate that HDR-mediated gene editing successfully integrated the IRES-insulin loop into the genome of HEK-293T cells, a non-endocrine cell line, enabling the expression of human-derived insulin. Furthermore, Cytopore I microcarriers facilitated cell attachment and proliferation during in vitro culture and enhanced cell survival post-transplantation. Transplantation of these cell-laden microcarriers into mice led to the development of a stable, fat-encapsulated structure. This structure exhibited the expression of the platelet-endothelial cell adhesion molecule CD31, and no significant immune rejection was observed throughout the experiment. Diabetic mice that received the cell carriers reversed hyperglycemia, and blood glucose fluctuations under simulated feeding stimuli were very similar to those of healthy mice. Conclusion: In summary, our study demonstrates that Cytopore I microcarriers are biocompatible and promote long-term cell survival in vivo. The promoter-free EMCVIRES-insulin loop enables non-endocrine cells to secrete mature insulin, leading to a rapid reduction in glucose levels. We have presented a novel promoter-free genetic engineering strategy for insulin secretion and proposed an efficient cell transplantation method. Our findings suggest the potential to expand the range of cell sources available for the treatment of diabetes, offering new avenues for therapeutic interventions.
Assuntos
Diabetes Mellitus Tipo 1 , Edição de Genes , Hiperglicemia , Células Secretoras de Insulina , Insulina , Humanos , Animais , Hiperglicemia/terapia , Hiperglicemia/metabolismo , Camundongos , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Insulina/genética , Células HEK293 , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/genética , Edição de Genes/métodos , Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/genética , Sítios Internos de Entrada Ribossomal/genética , Regiões Promotoras Genéticas , Sistemas CRISPR-CasRESUMO
The aim of the current study was to investigate the tear proteome in children and adolescents with type 1 diabetes (T1D) compared to healthy controls, and to identify differences in the tear proteome of children with T1D depending on different characteristics of the disease. Fifty-six children with T1D at least one year after diagnosis, aged 6-17 years old, and fifty-six healthy age- and sex-matched controls were enrolled in this cross-sectional study. The proteomic analysis was based on liquid chromatography tandem mass spectrometry (LC-MS/MS) enabling the identification and quantification of the protein content via Data-Independent Acquisition by Neural Networks (DIA-NN). Data are available via ProteomeXchange with the identifier PXD052994. In total, 3302 proteins were identified from tear samples. Two hundred thirty-nine tear proteins were differentially expressed in children with T1D compared to healthy controls. Most of them were involved in the immune response, tissue homeostasis and inflammation. The presence of diabetic ketoacidosis at diagnosis and the level of glycemic control of children with T1D influenced the tear proteome. Tear proteomics analysis revealed a different proteome pattern in children with T1D compared to healthy controls offering insights on deregulated biological processes underlying the pathogenesis of T1D. Differences within the T1D group could unravel biomarkers for early detection of long-term complications of T1D.
Assuntos
Biomarcadores , Diabetes Mellitus Tipo 1 , Proteômica , Lágrimas , Humanos , Diabetes Mellitus Tipo 1/metabolismo , Criança , Adolescente , Masculino , Feminino , Biomarcadores/metabolismo , Lágrimas/metabolismo , Proteômica/métodos , Estudos Transversais , Espectrometria de Massas em Tandem , Proteoma/análise , Proteoma/metabolismo , Cromatografia Líquida , Estudos de Casos e Controles , Proteínas do Olho/metabolismoRESUMO
Diabetic cardiomyopathy is a major etiological factor in heart failure in diabetic patients, characterized by mitochondrial oxidative metabolism dysfunction, myocardial fibrosis, and marked glycogen elevation. The aim of the present study is to evaluate the effect of endurance training and prebiotic xylooligosaccharide (XOS) on the activity of key oxidative enzymes, myocardial collagen, and glycogen distribution as well as some serum biochemical risk markers in streptozotocin-induced type 1 diabetic rats. Male Wistar rats (n = 36) were divided into four diabetic groups (n = 9): sedentary diabetic rats on a normal diet (SDN), trained diabetic rats on a normal diet (TDN), trained diabetic rats on a normal diet with an XOS supplement (TD-XOS), and sedentary diabetic rats with an XOS supplement (SD-XOS). The results show that aerobic training managed to increase the enzyme activity of respiratory Complex I and II and the lactate dehydrogenase in the cardiomyocytes of the diabetic rats. Furthermore, the combination of exercise and XOS significantly decreased the collagen and glycogen content. No significant effects on blood pressure, heart rate or markers of inflammation were detected. These results demonstrate the beneficial effects of exercise, alone or in combination with XOS, on the cardiac mitochondrial enzymology and histopathology of diabetic rats.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Treino Aeróbico , Glucuronatos , Oligossacarídeos , Condicionamento Físico Animal , Prebióticos , Ratos Wistar , Animais , Ratos , Masculino , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/complicações , Glucuronatos/farmacologia , Prebióticos/administração & dosagem , Treino Aeróbico/métodos , Glicogênio/metabolismo , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/prevenção & controle , Cardiomiopatias Diabéticas/metabolismo , Cardiomiopatias Diabéticas/etiologiaRESUMO
Autoimmune attack toward pancreatic ß cells causes permanent loss of glucose homeostasis in type 1 diabetes (T1D). Insulin secretory granules store and secrete insulin but are also thought to be tissue messengers for T1D. Here, we show that the crinophagic granules (crinosome), a minor set of vesicles formed by fusing lysosomes with the conventional insulin dense-core granules (DCG), are pathogenic in T1D development in mouse models. Pharmacological inhibition of crinosome formation in ß cells delays T1D progression without affecting the dominant DCGs. Mechanistically, crinophagy inhibition diminishes the epitope repertoire in pancreatic islets, including cryptic, modified and disease-relevant epitopes derived from insulin. These unconventional insulin epitopes are largely undetectable in the MHC-II epitope repertoire of the thymus, where only canonical insulin epitopes are presented. CD4+ T cells targeting unconventional insulin epitopes display autoreactive phenotypes, unlike tolerized T cells recognizing epitopes presented in the thymus. Thus, the crinophagic pathway emerges as a tissue-intrinsic mechanism that transforms insulin from a signature thymic self-protein to a critical autoantigen by creating a peripheral-thymic mismatch in the epitope repertoire.
Assuntos
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Insulina , Animais , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Camundongos , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Insulina/imunologia , Epitopos/imunologia , Linfócitos T CD4-Positivos/imunologia , Vesículas Secretórias/metabolismo , Vesículas Secretórias/imunologia , Camundongos Endogâmicos NOD , Autoantígenos/imunologia , Autoantígenos/metabolismo , Feminino , Modelos Animais de Doenças , Timo/imunologia , Humanos , Lisossomos/metabolismo , Lisossomos/imunologiaRESUMO
Processing of proglucagon into glucagon-like peptide-1 (GLP-1) and GLP-2 in intestinal L cells is mediated by the prohormone convertase 1/3 (PC1/3) while PC2 is responsible for the synthesis of glucagon in pancreatic alpha cells. While GLP-1 is also produced by alpha cells, the identity of the convertase involved in its synthesis is still unsettled. It also remains to be determined whether all alpha cells produce the incretin. The aims of this study were first, to elucidate the identity of the proconvertase responsible for GLP-1 production in human alpha cells, and second, to ascertain whether the number of glucagon cells expressing GLP-1 increase during diabetes. To answer these questions, sections of pancreas from donors' non-diabetic controls, type 1 and type 2 diabetes were processed for double-labelled immunostaining of glucagon and GLP-1 and of each hormone and either PC1 or PC2. Stained sections were examined by confocal microscopy. It was found that all alpha cells of islets from those three groups expressed GLP-1 and PC2 but not PC1/3. This observation supports the view that PC2 is the convertase involved in GLP-1 synthesis in all human glucagon cells and suggests that the regulation of its activity may have important clinical application in diabetes.
Assuntos
Peptídeo 1 Semelhante ao Glucagon , Células Secretoras de Glucagon , Pró-Proteína Convertase 1 , Pró-Proteína Convertase 2 , Humanos , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Células Secretoras de Glucagon/metabolismo , Pró-Proteína Convertase 1/metabolismo , Pró-Proteína Convertase 1/genética , Pró-Proteína Convertase 2/metabolismo , Pró-Proteína Convertase 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Glucagon/metabolismo , Adulto , Masculino , Pessoa de Meia-Idade , FemininoRESUMO
Apart from insulin, physical exercise is a crucial component of therapy in patients with type 1 diabetes mellitus (T1DM). The benefits of physical activity in such patients include improved insulin sensitivity, lowered blood glucose, reduced body fat and improved cardiovascular function and physical performance. Hypoglycemia is a crucial issue in the peri-training period in insulin-treated patients. Proper preparation for exercise is the key to reducing the risk of hypoglycemia. The selection of the training type and the patient's knowledge of the effect of such training on glycemia are also significant. Physical exercise under normobaric hypoxia in the training rooms is also available commercially and is becoming increasingly popular. Under such conditions, the air consists of 15.4% oxygen and 84.5% nitrogen, which corresponds to the conditions at an altitude of approximately 2,500 meters above sea level. Hypoxia induces the production of the hypoxia-inducible factor (HIF-1), which regulates the expression of over 100 genes. It modulates key metabolic pathways to optimize glucose utilization by increasing cell sensitivity to insulin, more efficient glucose uptake from the blood and activating effect on glycolytic enzymes. Additionally, HIF-1 shows beneficial effects on the lipid profile, vascular endothelium and performance as measured by the maximal oxygen uptake (VO2max). The aim of this paper was to review and summarize the most recent studies on the effects of exercise on glycemic control and physical performance under normoxia and normobaric hypoxia in patients with T1DM.
Assuntos
Diabetes Mellitus Tipo 1 , Hipóxia , Humanos , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/complicações , Exercício Físico/fisiologia , Glicemia/metabolismo , Terapia por Exercício/métodos , HipoglicemiaRESUMO
Diabetes mellitus is known as the "epidemic of the century" due to its global prevalence. Several pre-clinical and clinical studies have shown that male germ cell toxicity is one of the major consequences of diabetes mellitus. Although ß-aminoisobutyric acid (BAIBA) has been shown to be advantageous in the diabetic nephropathy and cardiomyopathy, its specific role in the diabetes-induced testicular toxicity remains unknown. In this study, an attempt was made to elucidate the molecular mechanisms of BAIBA-mediated germ cell protection in diabetic rats. Adult male Sprague-dawley rats were subjected to either no treatment (control) or BAIBA (100â¯mg/kg; BAIBA control) or Streptozotocin (50â¯mg/kg; diabetic control) or low (25â¯mg/kg), medium (50â¯mg/kg) and high (100â¯mg/kg) doses of BAIBA in diabetic conditions. Significant alterations in sperm related parameters, oxidative stress and apoptotic biomarkers, pancreatic and testicular histology, DNA damage and changes in expression of proteins in testes were found in the diabetic rats. 100â¯mg/kg of BAIBA significantly reduced the elevated blood glucose levels (P ≤ 0.05), increased body weight (P ≤ 0.01 in the 4th week), lowered malondialdehyde (P ≤ 0.05) and nitrite levels (P ≤ 0.01), elevated testosterone (P ≤ 0.05) and FSH levels (P ≤ 0.05), increased sperm count and motility (P ≤ 0.01), decreased testicular DNA damage (P ≤ 0.001), improved histological features of pancreas and testes, decreased TUNEL positive cells (P ≤ 0.01), decreased RAGE (P ≤ 0.01) and Bax (P ≤ 0.05) expressions and increased SIRT1 (P ≤ 0.05) and Atg 12 (P ≤ 0.05) expressions in the testes. 50â¯mg/kg of BAIBA partially restored the above-mentioned parameters whereas 25â¯mg/kg of BAIBA was found to be insignificant in counteracting the toxicity. It is interesting to note that BAIBA protects male germ cell damage in diabetic rats by regulating the IGF-1/AMPK/SIRT-1 signaling pathway.
Assuntos
Ácidos Aminoisobutíricos , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Fator de Crescimento Insulin-Like I , Estresse Oxidativo , Ratos Sprague-Dawley , Transdução de Sinais , Sirtuína 1 , Testículo , Animais , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/metabolismo , Sirtuína 1/genética , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Testículo/efeitos dos fármacos , Testículo/metabolismo , Testículo/patologia , Ácidos Aminoisobutíricos/farmacologia , Fator de Crescimento Insulin-Like I/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Dano ao DNA/efeitos dos fármacosRESUMO
GLP-1 receptor agonists, which were initially intended to treat type 2 diabetes patients, have demonstrated promise as an adjuvant therapy for type 1 diabetes (T1D). These medications can manage T1D by improving ß-cell function, reducing glucose fluctuation, and providing cardioprotective effects. Recent research suggests that boosting cell proliferation and lowering apoptosis can help maintain the bulk of ß-cells. Furthermore, GLP-1 receptor agonists have potent anti-inflammatory characteristics, improving immunological control and lowering systemic inflammation, both of which are critical for reducing autoimmune damage in T1D. Beyond glucose control, these agonists have neuroprotective qualities and aid in weight management. Combining these medications with insulin could significantly change how T1D is managed. The clinical data and biological mechanisms discussed in this review support the potential use of GLP-1 receptor agonists in T1D.
Assuntos
Diabetes Mellitus Tipo 1 , Receptor do Peptídeo Semelhante ao Glucagon 1 , Hipoglicemiantes , Humanos , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Hipoglicemiantes/uso terapêutico , Hipoglicemiantes/farmacologia , Animais , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Insulina/uso terapêutico , Agonistas do Receptor do Peptídeo 1 Semelhante ao GlucagonRESUMO
BACKGROUND: Islet or ß-cell transplantation is a therapeutical approach to substitute the insulin-producing cells which are abolished in type 1 diabetes mellitus. The shortage of human islets as well as the complicated and costly isolation process limit the application of these techniques in daily clinical practice. EndoC-ßH is a human ß-cell line that readily forms aggregates termed pseudoislets, providing an alternative to primary human islets or ß-cells. METHODS: EndoC-ßH3 cells were seeded and incubated to form pseudoislets. Their insulin secretion was analyzed by ELISA and compared with cell monolayers. Pseudoislets were transplanted into streptozotocin-treated NMRi nu/nu mice. Blood glucose was monitored before and after transplantation and compared with wild types. Grafts were analyzed by immunohistology. RESULTS: This study shows that EndoC-ßH cells are able to form pseudoislets by aggregation, leading to an enhanced glucose stimulated insulin secretion in vitro. These pseudoislets were then successfully transplanted into the livers of diabetic mice and produced insulin in vitro. Blood glucose levels of the streptozocin-treated recipient mice were significantly decreased when compared to pre-transplantation and matched the levels found in control mice. CONCLUSION: We suggest pseudoislets aggregated from EndoC-ßH cells as a valuable and promising model for islet transplantation research.
Assuntos
Glicemia , Diabetes Mellitus Experimental , Células Secretoras de Insulina , Insulina , Transplante das Ilhotas Pancreáticas , Animais , Diabetes Mellitus Experimental/terapia , Camundongos , Transplante das Ilhotas Pancreáticas/métodos , Humanos , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Glicemia/metabolismo , Secreção de Insulina , Linhagem Celular , Camundongos Nus , Masculino , Agregação Celular , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/cirurgia , Diabetes Mellitus Tipo 1/metabolismoRESUMO
The level of ROS (fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate) and lipid content (fluorescent lipophilic dye Nile Red) in the peripheral blood monocyte fraction from patients with type 1 diabetes mellitus and healthy volunteers were assessed by flow cytofluorimetry. The number of CD36+ monocytes was assessed using specific antibodies. In patients with type 1 diabetes mellitus, the levels of ROS and intracellular lipids in monocytes and the number of cells expressing CD36 fatty acid translocase were elevated. These results indicate metabolic changes in the peripheral blood cells of patients with carbohydrate metabolism disorders and can be considered as possible prognostic markers for the development of type 1 diabetes mellitus complications.
Assuntos
Diabetes Mellitus Tipo 1 , Monócitos , Espécies Reativas de Oxigênio , Humanos , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/metabolismo , Monócitos/metabolismo , Masculino , Adulto , Feminino , Espécies Reativas de Oxigênio/metabolismo , Antígenos CD36/metabolismo , Antígenos CD36/sangue , Estudos de Casos e Controles , Citometria de Fluxo , Adulto Jovem , Metabolismo dos LipídeosRESUMO
Well-controlled type 1 diabetes (T1DM) is characterized by inflammation and endothelial dysfunction, thus constituting a suitable model of subclinical cardiovascular disease (CVD). miR-199b-5p overexpression in murine CVD has shown proatherosclerotic effects. We hypothesized that miR-199b-5p would be overexpressed in subclinical CVD yet downregulated following metformin therapy. Inflammatory and vascular markers were measured in 29 individuals with T1DM and 20 matched healthy controls (HCs). miR-199b-5p expression in CFU-Hill's colonies was analyzed from each study group, and correlations with inflammatory/vascular health indices were evaluated. Significant upregulation of miR-199b-5p was observed in T1DM, which was significantly downregulated by metformin. miR-199b-5p correlated positively with vascular endothelial growth factor-D and c-reactive protein (CRP: nonsignificant). ROC analysis determined miR-199b-5p to define subclinical CVD by discriminating between HCs and T1DM individuals. ROC analyses of HbA1c and CRP showed that the upregulation of miR-199b-5p in T1DM individuals defined subclinical CVD at HbA1c > 44.25 mmol and CRP > 4.35 × 106 pg/mL. Ingenuity pathway analysis predicted miR-199b-5p to inhibit the target genes SIRT1, ETS1, and JAG1. Metformin was predicted to downregulate miR-199b-5p via NFATC2 and STAT3 and reverse its downstream effects. This study validated the antiangiogenic properties of miR-199b-5p and substantiated miR-199b-5p overexpression as a biomarker of subclinical CVD. The downregulation of miR-199b-5p by metformin confirmed its cardio-protective effect.
Assuntos
Doenças Cardiovasculares , Metformina , MicroRNAs , MicroRNAs/genética , MicroRNAs/metabolismo , Metformina/farmacologia , Metformina/uso terapêutico , Humanos , Masculino , Feminino , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Adulto , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Inflamação/genética , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Sirtuína 1/metabolismo , Sirtuína 1/genética , Proteína C-Reativa/metabolismo , Proteína C-Reativa/genética , Pessoa de Meia-Idade , Regulação da Expressão Gênica/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Proteína Jagged-1/metabolismo , Proteína Jagged-1/genética , Biomarcadores , Estudos de Casos e ControlesRESUMO
Multicenter international clinical trials demonstrated the clinical safety and efficacy by using stem cell educator therapy to treat type 1 diabetes (T1D) and other autoimmune diseases. Previous studies characterized the peripheral blood insulin-producing cells (PB-IPC) from healthy donors with high potential to give rise to insulin-producing cells. PB-IPC displayed the molecular marker glucose transporter 2 (GLUT2), contributing to the glucose transport and sensing. To improve the clinical efficacy of stem cell educator therapy in the restoration of islet ß-cell function, we explored the GLUT2 expression on PB-IPC in recent onset and longstanding T1D patients. In the Food and Drug Administration (FDA)-approved phase 2 clinical studies, patients received one treatment with the stem cell educator therapy. Peripheral blood mononuclear cells (PBMC) were isolated for flow cytometry analysis of PB-IPC and other immune markers before and after the treatment with stem cell educator therapy. Flow cytometry revealed that both recent onset and longstanding T1D patients displayed very low levels of GLUT2 on PB-IPC. After the treatment with stem cell educator therapy, the percentages of GLUT2+CD45RO+ PB-IPC were markedly increased in these T1D subjects. Notably, we found that T1D patients shared common clinical features with patients with other autoimmune and inflammation-associated diseases, such as displaying low or no expression of GLUT2 on PB-IPC at baseline and exhibiting a high profile of the inflammatory cytokine interleukin (IL)-1ß. Flow cytometry demonstrated that their GLUT2 expressions on PB-IPC were also markedly upregulated, and the levels of IL-1ß-positive cells were significantly downregulated after the treatment with stem cell educator therapy. Stem cell educator therapy could upregulate the GLUT2 expression on PB-IPC and restore their function in T1D patients, leading to the improvement of clinical outcomes. The clinical data advances current understanding about the molecular mechanisms underlying the stem cell educator therapy, which can be expanded to treat patients with other autoimmune and inflammation-associated diseases.
Assuntos
Diabetes Mellitus Tipo 1 , Transportador de Glucose Tipo 2 , Células Secretoras de Insulina , Insulina , Humanos , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/sangue , Transportador de Glucose Tipo 2/metabolismo , Transportador de Glucose Tipo 2/genética , Células Secretoras de Insulina/metabolismo , Masculino , Feminino , Insulina/metabolismo , Adulto , Leucócitos Mononucleares/metabolismo , Pessoa de Meia-Idade , Transplante de Células-TroncoRESUMO
BACKGROUND: We aimed to investigate whether alpha-galactosylceramide (α-GalCer)-producing Bacteroides fragilis could induce natural killer T (NKT) cells in nonobese diabetic (NOD) mice and reduce their diabetes incidence. METHODS: Five-week-old female NOD mice were treated orally with B. fragilis, and islet pathology and diabetes onset were monitored. Immune responses were analyzed by flow cytometry and multiplex technology. Effects of ultraviolet (UV)-killed α-GalCer-producing B. fragilis and their culture medium on invariant NKT (iNKT) cells were tested ex vivo on murine splenocytes, and the immunosuppressive capacity of splenocytes from B. fragilis-treated NOD mice were tested by adoptive transfer to nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. RESULTS: B. fragilis reduced the diabetes incidence from 69% to 33% and the percent of islets with insulitis from 40% to 7%, which doubled the serum insulin level compared with the vehicle-treated control mice. Furthermore, the early treatment reduced proinflammatory mediators in the serum, whereas the proportion of CD4+ NKT cell population was increased by 33%. B. fragilis growth media stimulated iNKT cells and anti-inflammatory M2 macrophages ex vivo in contrast to UV-killed bacteria, which had no effect, strongly indicating an α-GalCer-mediated effect. Adoptive transfer of splenocytes from B. fragilis-treated NOD mice induced a similar diabetes incidence as splenocytes from untreated NOD mice. CONCLUSIONS: B. fragilis induced iNKT cells and M2 macrophages and reduced type 1 diabetes in NOD mice. The protective effect seemed to be more centered on gut-pancreas interactions rather than a systemic immunosuppression. B. fragilis should be considered for probiotic use in individuals at risk of developing type 1 diabetes.
Assuntos
Bacteroides fragilis , Galactosilceramidas , Camundongos Endogâmicos NOD , Células T Matadoras Naturais , Probióticos , Animais , Feminino , Galactosilceramidas/farmacologia , Probióticos/uso terapêutico , Probióticos/farmacologia , Camundongos , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Diabetes Mellitus Tipo 1/prevenção & controle , Diabetes Mellitus Tipo 1/metabolismo , Incidência , Camundongos SCIDRESUMO
Background: The functional changes in alpha cells in patients with type 1 diabetes (T1D) with different residual beta cell functions remain poorly elucidated. The study aimed to investigate the relationship between glucagon secretion and C-peptide levels and to explore the relationship between glucagon response and glucose increment in respond to a secretagogue in a steamed bread meal tolerance test (BMTT) in T1D. Methods: The study enrolled 43 adult patients with T1D and 24 healthy control subjects. Patients with T1D who underwent BMTT were divided into two groups based on peak C-peptide levels: C peptide low (CPL; C-peptide < 200 pmol/L; n=14) and high (CPH; C peptide ≥ 200 pmol/L; n=29). Plasma glucose, C-peptide, glucagon levels at 0, 30, 60, 120, and 180 min were measured. The glucagon response to the BMTT was defined by areas under the curve (AUC) as early (AUC0-30), late (AUC30-180), or total (AUC0-180) glucagon. Results: Compared to healthy individuals, fasting plasma glucagon was lower and postprandial plasma glucagon level was increased in patients with T1D. Glucagon levels after BMTT between the CPL and CPH group showed significant group by time interaction. Peak glucagon and glucagon at 60-180 min, total and late glucagon response were higher in CPL than CPH group, while fasting glucagon and early glucagon response adjusted for glucose were comparable between CPL and CPH group. The higher late glucagon response and late glucagon response adjusted for glucose were associated with lower peak C-peptide in T1D. The higher late glucagon response and lower peak C-peptide were associated with the higher value of âµglucose at 180 min. Conclusion: Stimulated C-peptide levels affect the paradoxical increase in postprandial glucagon secretion in patients with T1D, especially late glucagon response. The exaggerated postprandial glucagon secretion further stimulates the elevation of postprandial glucose in patients with T1D.