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1.
Biomolecules ; 11(7)2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34356612

RESUMO

Vascular endothelial growth factor (VEGF) is a major therapeutic target for blood-retina barrier (BRB) breakdown in diabetic retinopathy (DR), age-related macular degeneration (AMD), and other hypoxic retinal vascular disorders. To determine whether VEGF is a direct regulator of retinal neuronal function and its potential role in altering vision during the progression of DR, we examined the immediate impact of recombinant VEGF (rVEGF) on photoreceptor function with electroretinography in C57BL6 background wild-type (WT) and Akita spontaneous diabetic mice. Shortly after intravitreal injections, rVEGF caused a significant reduction of scotopic ERG a-wave and b-wave amplitudes and photopic ERG b-wave amplitudes in a dose-dependent manner in dark-adapted 1.5-mo-old WT mice. Compared with WT controls, 5-mo-old Akita spontaneous diabetic mice demonstrated a significant reduction in scotopic ERG a-wave and b-wave amplitudes and photopic ERG b-wave amplitudes. However, the effect of rVEGF altered photoreceptor function in WT controls was diminished in 5-mo-old Akita spontaneous diabetic mice. In conclusion, our results suggest that VEGF is a direct functional regulator of photoreceptors and VEGF up-regulation in DR is a contributing factor to diabetes-induced alteration of photoreceptor function. This information is critical to the understanding of the therapeutic effect and to the care of anti-VEGF drug-treated patients for BRB breakdown in DR, AMD, and other hypoxic retinal vascular disorders.


Assuntos
Barreira Hematorretiniana/metabolismo , Diabetes Mellitus Experimental/metabolismo , Retinopatia Diabética/metabolismo , Células Fotorreceptoras de Vertebrados/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Barreira Hematorretiniana/patologia , Diabetes Mellitus Experimental/patologia , Retinopatia Diabética/patologia , Camundongos , Células Fotorreceptoras de Vertebrados/patologia , Fator A de Crescimento do Endotélio Vascular/farmacologia
2.
Life Sci ; 283: 119870, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34352258

RESUMO

OBJECTIVE: Increased renal and hepatic gluconeogenesis are important sources of fasting hyperglycemia in type 2 diabetes (T2D). The inhibitory effect of co-administration of sodium nitrite and sodium hydrosulfide (NaSH) on hepatic but not renal gluconeogenesis has been reported in rats with T2D. The present study aimed to determine the effects of co-administration of sodium nitrite and NaSH on the expression of genes involved in renal gluconeogenesis in rats with T2D. METHODS: T2D was induced by a combination of a high-fat diet and low-dose streptozotocin (30 mg/kg). Male Wistar rats were divided into 5 groups (n = 6/group): Control, T2D, T2D + nitrite, T2D + NaSH, and T2D + nitrite+NaSH. Nitrite and NaSH were administered for nine weeks at a dose of 50 mg/L (in drinking water) and 0.28 mg/kg (daily intraperitoneal injection), respectively. Serum levels of urea and creatinine, and mRNA expressions of PEPCK, G6Pase, FBPase, PC, PI3K, AKT, PGC-1α, and FoxO1 in the renal tissue, were measured at the end of the study. RESULTS: Nitrite decreased mRNA expression of PEPCK by 39%, G6Pase by 43%, FBPase by 41%, PC by 63%, PGC-1α by 45%, and FoxO1 by 27% in the renal tissue of rats with T2D; co-administration of nitrite and NaSH further decreases FoxO1, while had no additive effects on the tissue expression of the other genes. In addition, nitrite+NaSH decreased elevated serum urea levels by 58% and creatinine by 37% in rats with T2D. CONCLUSION: The inhibitory effect of nitrite on gluconeogenesis in T2D rats is at least in part due to decreased mRNA expressions of renal gluconeogenic genes. Unlike effects on hepatic gluconeogenesis, co-administration of nitrite and NaSH has no additive effects on genes involved in renal gluconeogenesis in rats with T2D.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Gluconeogênese/efeitos dos fármacos , Rim/metabolismo , Nitrito de Sódio/farmacologia , Sulfetos/farmacologia , Animais , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/patologia , Rim/patologia , Masculino , Ratos , Ratos Wistar
3.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445504

RESUMO

Although previous studies continuously report an increased risk of hearing loss in diabetes patients, the impact of the disease on the inner ear remains unexplored. Herein, we examine the pathophysiology of diabetes-associated hearing impairment and cochlear synaptopathy in a mouse model of diabetes. Male B6.BKS(D)-Leprdb/J (db/db, diabetes) and heterozygote (db/+, control) mice were assigned into each experimental group (control vs. diabetes) based on the genotype and tested for hearing sensitivity every week from 6 weeks of age. Each cochlea was collected for histological and biological assays at 14 weeks of age. The diabetic mice exerted impaired hearing and a reduction in cochlear blood flow and C-terminal-binding protein 2 (CtBP2, a presynaptic ribbon marker) expression. Ultrastructural images revealed severely damaged mitochondria from diabetic cochlea accompanied by a reduction in Cytochrome c oxidase subunit 4 (COX4) and CR6-interacting factor 1 (CRIF1). The diabetic mice presented significantly decreased levels of platelet endothelial cell adhesion molecule (PECAM-1), B-cell lymphoma 2 (BCL-2), and procaspase-9, but not procaspase-8. Importantly, significant changes were not found in necroptotic programmed cell death markers (receptor-interacting serine/threonine-protein kinase 1, RIPK1; RIPK3; and mixed lineage kinase domain-like pseudokinase, MLKL) between the groups. Taken together, diabetic hearing loss is accompanied by synaptopathy, microangiopathy, damage to the mitochondrial structure/function, and activation of the intrinsic apoptosis pathway. Our results imply that mitochondrial dysfunction is deeply involved in diabetic hearing loss, and further suggests the potential benefits of therapeutic strategies targeting mitochondria.


Assuntos
Diabetes Mellitus Experimental/complicações , Perda Auditiva/fisiopatologia , Mitocôndrias/ultraestrutura , Receptores para Leptina/genética , Animais , Apoptose , Biomarcadores/metabolismo , Cóclea/irrigação sanguínea , Cóclea/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Modelos Animais de Doenças , Regulação para Baixo , Perda Auditiva/etiologia , Perda Auditiva/genética , Perda Auditiva/metabolismo , Humanos , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Mitocôndrias/metabolismo
4.
Int J Mol Sci ; 22(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34445304

RESUMO

Dysfunctional islets of Langerhans are a hallmark of type 2 diabetes (T2D). We hypothesize that differences in islet gene expression alternative splicing which can contribute to altered protein function also participate in islet dysfunction. RNA sequencing (RNAseq) data from islets of obese diabetes-resistant and diabetes-susceptible mice were analyzed for alternative splicing and its putative genetic and epigenetic modulators. We focused on the expression levels of chromatin modifiers and SNPs in regulatory sequences. We identified alternative splicing events in islets of diabetes-susceptible mice amongst others in genes linked to insulin secretion, endocytosis or ubiquitin-mediated proteolysis pathways. The expression pattern of 54 histones and chromatin modifiers, which may modulate splicing, were markedly downregulated in islets of diabetic animals. Furthermore, diabetes-susceptible mice carry SNPs in RNA-binding protein motifs and in splice sites potentially responsible for alternative splicing events. They also exhibit a larger exon skipping rate, e.g., in the diabetes gene Abcc8, which might affect protein function. Expression of the neuronal splicing factor Srrm4 which mediates inclusion of microexons in mRNA transcripts was markedly lower in islets of diabetes-prone compared to diabetes-resistant mice, correlating with a preferential skipping of SRRM4 target exons. The repression of Srrm4 expression is presumably mediated via a higher expression of miR-326-3p and miR-3547-3p in islets of diabetic mice. Thus, our study suggests that an altered splicing pattern in islets of diabetes-susceptible mice may contribute to an elevated T2D risk.


Assuntos
Processamento Alternativo/fisiologia , Diabetes Mellitus Tipo 2/genética , Ilhotas Pancreáticas/metabolismo , Processamento Alternativo/genética , Animais , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Suscetibilidade a Doenças , Secreção de Insulina/genética , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/genética , Obesidade/metabolismo , Obesidade/patologia , Regulação para Cima/genética
5.
Molecules ; 26(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34361788

RESUMO

This research investigated a UPLC-QTOF/ESI-MS-based phytochemical profiling of Combretum indicum leaf extract (CILEx), and explored its in vitro antioxidant and in vivo antidiabetic effects in a Long-Evans rat model. After a one-week intervention, the animals' blood glucose, lipid profile, and pancreatic architectures were evaluated. UPLC-QTOF/ESI-MS fragmentation of CILEx and its eight docking-guided compounds were further dissected to evaluate their roles using bioinformatics-based network pharmacological tools. Results showed a very promising antioxidative effect of CILEx. Both doses of CILEx were found to significantly (p < 0.05) reduce blood glucose, low-density lipoprotein (LDL), and total cholesterol (TC), and increase high-density lipoprotein (HDL). Pancreatic tissue architectures were much improved compared to the diabetic control group. A computational approach revealed that schizonepetoside E, melianol, leucodelphinidin, and arbutin were highly suitable for further therapeutic assessment. Arbutin, in a Gene Ontology and PPI network study, evolved as the most prospective constituent for 203 target proteins of 48 KEGG pathways regulating immune modulation and insulin secretion to control diabetes. The fragmentation mechanisms of the compounds are consistent with the obtained effects for CILEx. Results show that the natural compounds from CILEx could exert potential antidiabetic effects through in vivo and computational study.


Assuntos
Antioxidantes/farmacologia , Combretum/química , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Arbutina/química , Arbutina/isolamento & purificação , Sítios de Ligação , Glicemia/efeitos dos fármacos , HDL-Colesterol/agonistas , HDL-Colesterol/sangue , LDL-Colesterol/antagonistas & inibidores , LDL-Colesterol/sangue , Biologia Computacional/métodos , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Flavonoides/química , Flavonoides/isolamento & purificação , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Insulina/agonistas , Insulina/metabolismo , Masculino , Modelos Moleculares , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Pâncreas/patologia , Extratos Vegetais/química , Folhas de Planta/química , Ligação Proteica , Conformação Proteica , Ratos , Ratos Long-Evans , Triterpenos/química , Triterpenos/isolamento & purificação
6.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360548

RESUMO

Keratin (K) 7 is an intermediate filament protein expressed in ducts and glands of simple epithelial organs and in urothelial tissues. In the pancreas, K7 is expressed in exocrine ducts, and apico-laterally in acinar cells. Here, we report K7 expression with K8 and K18 in the endocrine islets of Langerhans in mice. K7 filament formation in islet and MIN6 ß-cells is dependent on the presence and levels of K18. K18-knockout (K18‒/‒) mice have undetectable islet K7 and K8 proteins, while K7 and K18 are downregulated in K8‒/‒ islets. K7, akin to F-actin, is concentrated at the apical vertex of ß-cells in wild-type mice and along the lateral membrane, in addition to forming a fine cytoplasmic network. In K8‒/‒ ß-cells, apical K7 remains, but lateral keratin bundles are displaced and cytoplasmic filaments are scarce. Islet K7, rather than K8, is increased in K18 over-expressing mice and the K18-R90C mutation disrupts K7 filaments in mouse ß-cells and in MIN6 cells. Notably, islet K7 filament networks significantly increase and expand in the perinuclear regions when examined in the streptozotocin diabetes model. Hence, K7 represents a significant component of the murine islet keratin network and becomes markedly upregulated during experimental diabetes.


Assuntos
Diabetes Mellitus Experimental/patologia , Células Secretoras de Insulina/patologia , Queratina-18/metabolismo , Queratina-7/metabolismo , Queratina-8/metabolismo , Animais , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Regulação da Expressão Gênica , Células Secretoras de Insulina/metabolismo , Queratina-18/genética , Queratina-7/genética , Queratina-8/genética , Camundongos , Camundongos Knockout , Regulação para Cima
7.
Nutrients ; 13(7)2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371877

RESUMO

Pathological mechanisms underlining diabetic bone defects include oxidative damage and insulin/IGF-1 imbalance. Morin is a bioflavonoid with antioxidant and anti-diabetic effects. This study evaluates morin's protective effects against altered bone histomorphometry in diabetic rats through assessing insulin/IGF-1 pathway as a potential mechanism. Diabetic animals were administered two morin doses (15 and 30 mg/kg) for 5 weeks. Different serum hepatic and renal functions tests were assessed. Bone density and histomorphometry in cortical and trabecular tissues were evaluated histologically. The expressions of insulin, c-peptide and IGF-1 were estimated. In addition, the enzymatic activities of the major antioxidant enzymes were determined. Diabetic-associated alterations in serum glucose, aminotransferases, urea and creatinine were attenuated by morin. Diabetic bone cortical and trabecular histomorphometry were impaired with increased fibrosis, osteoclastic functions, osteoid formation and reduced mineralization, which was reversed by morin; particularly the 30 mg/kg dose. Insulin/IGF-1 levels were diminished in diabetic animals, while morin treatment enhanced their levels significantly. Diabetes also triggered systemic oxidative stress noticeably. The higher dose (30 mg/kg) of morin corrected the endogenous antioxidant enzymatic activities in diabetic rats. Findings indicate the potential value of morin supplementation against hyperglycemia-induced skeletal impairments. Activation of insulin/IGF-1 signaling could be the underlining mechanism behind these effects.


Assuntos
Antioxidantes/farmacologia , Glicemia/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Fêmur/efeitos dos fármacos , Flavonoides/farmacologia , Hipoglicemiantes/farmacologia , Fator de Crescimento Insulin-Like I/metabolismo , Insulina/sangue , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/patologia , Fêmur/metabolismo , Fêmur/patologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Transdução de Sinais , Estreptozocina
8.
Aging (Albany NY) ; 13(13): 17536-17547, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34233296

RESUMO

Pathological manifestations in either heart or kidney impact the function of the other and form the basis for the development of cardiorenal syndrome. However, the mechanism or factors involved in such scenario are not completely elucidated. In our study, to find the correlation between late fetal gene expression in diabetic hearts and their influence on diabetic nephropathy, we created a rat model with cardiac specific overexpression of IGF-IIRα, which is an alternative splicing variant of IGFIIR, expressed in pathological hearts. In this study, transgenic rats over expressing cardiac specific IGF-IIRα and non-transgenic animal models established in SD rats were administered with single dose of streptozotocin (STZ, 55 mg/Kg) to induce Type I diabetes. The correlation between IGF-IIRα and kidney damages were further determined based on their intensity of damage in the kidneys. The results show that cardiac specific overexpression of IGF-IIRα elevates the diabetes associated inflammation and morphological changes in the kidneys. The diabetic transgenic rats showed advancement in the pathological features such a renal tubular damage, collagen accumulation and enhancement in STAT3 associated mechanism of renal fibrosis. The results therefore show that that IGF-IIRα expression in the heart during pathological condition may worsen symptoms of diabetic nephropathy in rats.


Assuntos
Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Cardiomiopatias Diabéticas/genética , Cardiomiopatias Diabéticas/patologia , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/patologia , Receptor IGF Tipo 2/genética , Animais , Apoptose/genética , Colágeno/metabolismo , Fibrose , Regulação da Expressão Gênica , Rim/patologia , Túbulos Renais/patologia , Masculino , Miocárdio/patologia , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos , Fator de Transcrição STAT3/genética
9.
Int J Mol Sci ; 22(14)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34298949

RESUMO

Sodium glucose cotransporter-2 (SGLT2) inhibitors inhibit the development of diabetic nephropathy (DN). We determined whether changes in perirenal fat (PRAT) by a SGLT2 inhibitor ipragliflozin (Ipra) contribute to the suppression of DN development. High-fat diet (HFD)-fed mice were used as a DN model and were treated with or without Ipra for 6 weeks. Ipra treatment reduced urinary albumin excretion (UAE) and glomerular hypertrophy in HFD-fed mice. In the PRAT of Ipra-treated mice, adipocyte size was increased, and inflammation, fibrosis, and adipocyte death were suppressed. In conditioned medium made from PRAT (PRAT-CM) of Ipra-treated mice, the concentration of leptin was significantly lower than PRAT-CM of mice without Ipra treatment. Serum leptin concentration in renal vein positively correlated with UAE. PRAT-CM from HFD-fed mice showed greater cell proliferation signaling in mouse glomerular endothelial cells (GECs) than PRAT-CM from standard diet-fed mice via p38MAPK and leptin-dependent pathways, whose effects were significantly attenuated in PRAT-CM from Ipra-treated mice. These findings suggest that Ipra-induced PRAT expansion may play an important role in the improvement of DN in HFD-fed mice. In vitro experiments suggest that reduced PRAT-derived leptin by Ipra could inhibit GECs proliferation, possibly contributing to the suppression of DN development.


Assuntos
Tecido Adiposo/metabolismo , Diabetes Mellitus Experimental , Nefropatias Diabéticas , Glucosídeos/metabolismo , Glomérulos Renais/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Tiofenos/metabolismo , Tecido Adiposo/patologia , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Glomérulos Renais/patologia , Masculino , Camundongos
10.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209800

RESUMO

Diabetes mellitus (DM) is a chronic metabolic disease characterised by insulin deficiency, resulting in hyperglycaemia, a characteristic symptom of type 2 diabetes mellitus (DM2). DM substantially affects numerous metabolic pathways, resulting in ß-cell dysfunction, insulin resistance, abnormal blood glucose levels, impaired lipid metabolism, inflammatory processes, and excessive oxidative stress. Oxidative stress can affect the body's normal physiological function and cause numerous cellular and molecular changes, such as mitochondrial dysfunction. Animal models are useful for exploring the cellular and molecular mechanisms of DM and improving novel therapeutics for their safe use in human beings. Due to their health benefits, there is significant interest in a wide range of natural compounds that can act as naturally occurring anti-diabetic compounds. Due to rodent models' relatively similar physiology to humans and ease of handling and housing, they are widely used as pre-clinical models for studying several metabolic disorders. In this review, we analyse the currently available rodent animal models of DM and their advantages and disadvantages and highlight the potential anti-oxidative effects of natural compounds and their mechanisms of action.


Assuntos
Produtos Biológicos/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Produtos Biológicos/farmacologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Humanos , Estresse Oxidativo/fisiologia , Roedores
11.
Int J Mol Sci ; 22(13)2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34281287

RESUMO

Diabetic retinopathy (DR) is a common complication of diabetes that causes severe visual impairment globally. The pathogenesis of DR is related to oxidative stress and chronic inflammation. The fibroblast growth factor type 1 (FGF-1) mitogen plays crucial roles in cell function, development, and metabolism. FGF-1 is involved in blood sugar regulation and exerts beneficial antioxidative and anti-inflammatory effects on various organ systems. This study investigated the antioxidative and anti-inflammatory neuroprotective effects of FGF-1 on high-glucose-induced retinal damage. The results revealed that FGF-1 treatment significantly reversed the harmful effects of oxidative stress and inflammatory mediators in retinal tissue in a streptozotocin-induced diabetic rat model. These protective effects were also observed in the in vitro model of retinal ARPE-19 cells exposed to a high-glucose condition. We demonstrated that FGF-1 attenuated p38 mitogen-activated protein kinase and nuclear factor-κB pathway activation under the high-glucose condition. Our results indicated that FGF-1 could effectively prevent retinal injury in diabetes. The findings of this study could be used to develop novel treatments for DR that aim to reduce the cascade of oxidative stress and inflammatory signals in neuroretinal tissue.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Retinopatia Diabética/prevenção & controle , Fator 1 de Crescimento de Fibroblastos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Glicemia/metabolismo , Linhagem Celular , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Fator 1 de Crescimento de Fibroblastos/deficiência , Glucose/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Masculino , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
12.
Int J Mol Sci ; 22(11)2021 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-34072974

RESUMO

This study investigates whether reduced optic atrophy 1 (Opa1) level promotes apoptosis and retinal vascular lesions associated with diabetic retinopathy (DR). Four groups of mice: wild type (WT) control mice, streptozotocin (STZ)-induced diabetic mice, Opa1+/- mice, and diabetic Opa1+/- mice were used in this study. 16 weeks after diabetes onset, retinas were assessed for Opa1 and Bax levels by Western blot analysis, and retinal networks were examined for acellular capillaries (AC) and pericyte loss (PL). Apoptotic cells were detected in retinal capillaries using TUNEL assay, and caspase-3 activity was assessed using fluorometric analysis. Opa1 expression was significantly downregulated in retinas of diabetic and Opa1+/- mice compared with those of WT mice. Inducing diabetes further decreased Opa1 expression in retinas of Opa1+/- mice. Increased cytochrome c release concomitant with increased level of pro-apoptotic Bax and elevated caspase-3 activity were observed in retinas of diabetic and Opa1+/- mice; the number of TUNEL-positive cells and AC/PL was also significantly increased. An additional decrease in the Opa1 level in retinas of diabetic Opa1+/- mice exacerbated the development of apoptotic cells and AC/PL compared with those of diabetic mice. Diabetes-induced Opa1 downregulation contributes, at least in part, to the development of retinal vascular lesions characteristic of DR.


Assuntos
Capilares , Diabetes Mellitus Experimental/metabolismo , Retinopatia Diabética/metabolismo , GTP Fosfo-Hidrolases/fisiologia , Vasos Retinianos , Animais , Apoptose , Capilares/metabolismo , Capilares/patologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Retinopatia Diabética/etiologia , Retinopatia Diabética/patologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Vasos Retinianos/metabolismo , Vasos Retinianos/patologia
13.
Chem Biol Interact ; 345: 109562, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34153226

RESUMO

Advanced glycation end products (AGEs) are associated with the pathogenesis of diabetic vascular complications. Induction of the endothelial-to-mesenchymal transition (EndMT) is associated with the pathogenesis of fibrotic diseases. The roles of AGEs in islet EndMT induction and diabetes-related islet microvasculopathy and fibrosis remain unclear. This study investigated the pathological roles of AGEs in islet EndMT induction and fibrosis in vitro and in vivo. Non-cytotoxic concentrations of AGEs upregulated the protein expression of fibronectin, vimentin, and α-smooth muscle actin (α-SMA) (mesenchymal/myofibroblast markers) and downregulated the protein expression of vascular endothelial (VE)-cadherin and cluster of differentiation (CD) 31 (endothelial cell markers) in cultured mouse pancreatic islet endothelial cells, which was prevented by the AGE cross-link breaker alagebrium chloride. In streptozotocin-induced diabetic mice, the average islet area and islet immunoreactivities for insulin and CD31 were decreased and the islet immunoreactivities for AGEs and α-SMA and fibrosis were increased, which were prevented by the AGE inhibitor aminoguanidine. Immunofluorescence double staining showed that α-SMA-positive staining co-localized with CD31-positive staining in the diabetic islets, which was effectively prevented by aminoguanidine. These results demonstrate that AGEs can induce EndMT in islet endothelial cells and islet fibrosis in diabetic mice, suggesting that AGE-induced EndMT may contribute to islet fibrosis in diabetes.


Assuntos
Diabetes Mellitus Experimental/patologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Produtos Finais de Glicação Avançada/farmacologia , Ilhotas Pancreáticas/patologia , Mesoderma/patologia , Animais , Diferenciação Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Insulina/metabolismo , Mesoderma/efeitos dos fármacos , Camundongos , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo
14.
Am J Physiol Cell Physiol ; 321(3): C489-C503, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34191626

RESUMO

Mitochondrial transplantation is emerging as a novel cellular biotherapy to alleviate mitochondrial damage and dysfunction. Mitochondria play a crucial role in establishing cellular homeostasis and providing cell with the energy necessary to accomplish its function. Owing to its endosymbiotic origin, mitochondria share many features with their bacterial ancestors. Unlike the nuclear DNA, which is packaged into nucleosomes and protected from adverse environmental effects, mitochondrial DNA are more prone to harsh environmental effects, in particular that of the reactive oxygen species. Mitochondrial damage and dysfunction are implicated in many diseases ranging from metabolic diseases to cardiovascular and neurodegenerative diseases, among others. While it was once thought that transplantation of mitochondria would not be possible due to their semiautonomous nature and reliance on the nucleus, recent advances have shown that it is possible to transplant viable functional intact mitochondria from autologous, allogenic, and xenogeneic sources into different cell types. Moreover, current research suggests that the transplantation could positively modulate bioenergetics and improve disease outcome. Mitochondrial transplantation techniques and consequences of transplantation in cardiomyocytes are the theme of this review. We outline the different mitochondrial isolation and transfer techniques. Finally, we detail the consequences of mitochondrial transplantation in the cardiovascular system, more specifically in the context of cardiomyopathies and ischemia.


Assuntos
Cardiomiopatias/terapia , Diabetes Mellitus Experimental/terapia , Mitocôndrias Cardíacas/transplante , Infarto do Miocárdio/terapia , Traumatismo por Reperfusão Miocárdica/terapia , Miócitos Cardíacos/metabolismo , Animais , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Fracionamento Celular/métodos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Modelos Animais de Doenças , Humanos , Injeções Intralesionais , Mitocôndrias Cardíacas/fisiologia , Mitocôndrias Cardíacas/ultraestrutura , Dinâmica Mitocondrial/fisiologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/patologia , Fosforilação Oxidativa , Coelhos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Suínos
15.
J Photochem Photobiol B ; 221: 112248, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34192628

RESUMO

Melatonin is mainly secreted by the pineal gland, and it is also produced by various ocular structures such as the lens. It has been recently demonstrated that melatonin ocular synthesis can be induced by blocking the blue component of white light by means of filters. Melatonin exhibits antioxidant properties that can be useful to face light-induced oxidative stress as well as oxidative events associated to ocular pathologies like cataracts. Moreover, as oxidative stress is a main event in cataract development, changes in melatonin levels could happen and be relevant in the progression of this pathology, a subject that remains uncertain. The goal of this work was to analyze the ability of a short wavelength light blocking (yellow) filter to modulate endogenous melatonin concentration and the antioxidant and cytoprotective actions induced by yellow filter's use in lens. Furthermore, we evaluated the potential changes in aqueous humor melatonin concentration from patients with cataracts. In human lens epithelial cells, white light-emitting diode (LED) light challenge reduced melatonin secretion, protein levels of the enzymes involved in melatonin synthesis (hydroxyindole-O-methyltransferase and unphosphorylated and phosphorylated forms of arylalkylamine N-acetyltransferase) and cell viability whereas increased reactive oxygen species production. Yellow filter exposure precluded melatonin secretion reduction and protected cells from oxidative damage. Consistent with cataract patient's results, significantly lower levels of melatonin were observed in aqueous humor of alloxan-induced diabetic cataract rabbits as compared to those of control rabbits. In contrast, aqueous humor melatonin levels of diabetic cataract animals maintaining in cages covered with a yellow filter resembled control values. This recovery seems to be mediated by the induction of melatonin biosynthetic enzymes protein expression. Yellow filter also preserved Nrf2 lens protein expression and superoxide dismutase protein levels and activity in diabetic animals. Modulation of endogenous ocular melatonin concentration using blocking filters might be a promising approach to prevent premature lens opacification.


Assuntos
Humor Aquoso/metabolismo , Melatonina/metabolismo , Substâncias Protetoras/metabolismo , Idoso , Animais , Catarata/metabolismo , Catarata/patologia , Sobrevivência Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Células Epiteliais/efeitos da radiação , Feminino , Humanos , Cristalino/citologia , Luz , Masculino , Melatonina/farmacologia , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Coelhos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Regulação para Cima/efeitos dos fármacos
16.
J Leukoc Biol ; 110(3): 497-510, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34085308

RESUMO

Diabetes is emerging as a severe global health problem that threatens health and increases socioeconomic burden. Periodontal impairment is one of its well-recognized complications. The destruction of the periodontal defense barrier makes it easier for periodontal pathogens to invade in, triggering a greater inflammatory response, and causing secondary impairment. Macrophages are the major immune cells in periodontium, forming the frontier line of local innate immune barrier. Here, we explored the periodontal impairments and functional changes of macrophages under the diabetic and aging conditions. Besides, we further explored the molecular mechanism of how hyperglycemia and aging contribute to this pathogenesis. To test this, we used young and aged mice to build diabetic mice, and metformin treatment was applied to a group of them. We demonstrated that under hyperglycemia conditions, macrophage functions, such as inflammatory cytokines secretion, phagocytosis, chemotaxis, and immune response, were disturbed. Simultaneously, this condition elevated the local senescent cell burden and induced secretion of senescence-associated secretory phenotype. Meanwhile, we found that expressions of Gasdermin D (GSDMD) and caspase-1 were up-regulated in diabetic conditions, suggesting that the local senescent burden and systemic proinflammatory state during diabetes were accompanied by the initiation of pyroptosis. Furthermore, we found that the changes in aged condition were similar to those in diabetes, suggesting a hyperglycemia-induced pre-aging state. In addition, we show that metformin treatment alleviated and remarkably reversed these functional abnormalities. Our data demonstrated that diabetes initiated macrophage pyroptosis, which further triggered macrophage function impairments and gingival destructions. This pathogenesis could be reversed by metformin.


Assuntos
Citoplasma/metabolismo , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Diabetes Mellitus Experimental/patologia , Macrófagos/patologia , Piroptose , Envelhecimento/patologia , Animais , Apresentação do Antígeno/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Citocinas/metabolismo , Glucose/toxicidade , Hiperglicemia/complicações , Mediadores da Inflamação/metabolismo , Macrófagos/efeitos dos fármacos , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Periodonto/patologia , Fagocitose/efeitos dos fármacos , Piroptose/efeitos dos fármacos , Células RAW 264.7
17.
Nat Commun ; 12(1): 3363, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099651

RESUMO

Impaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL-HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.


Assuntos
Complexos de Coordenação/farmacologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Complexos de Coordenação/química , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/patologia , Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Irídio/química , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligação Proteica/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Cicatrização/genética
18.
Commun Biol ; 4(1): 594, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-34012065

RESUMO

Type 2 diabetes is characterized by ß and α cell dysfunction. We used phasor-FLIM (Fluorescence Lifetime Imaging Microscopy) to monitor oxidative phosphorylation and glycolysis in living islet cells before and after glucose stimulation. In healthy cells, glucose enhanced oxidative phosphorylation in ß cells and suppressed oxidative phosphorylation in α cells. In Type 2 diabetes, glucose increased glycolysis in ß cells, and only partially suppressed oxidative phosphorylation in α cells. FLIM uncovers key perturbations in glucose induced metabolism in living islet cells and provides a sensitive tool for drug discovery in diabetes.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Glucagon/metabolismo , Glucose/farmacologia , Células Secretoras de Insulina/metabolismo , Imagem Molecular/métodos , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/patologia , Células Secretoras de Glucagon/efeitos dos fármacos , Glicólise , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Microscopia de Fluorescência , Fosforilação Oxidativa , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos
19.
Biomed Pharmacother ; 140: 111760, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34052566

RESUMO

The global prevalence of diabetes mellitus is rapidly increasing. This disease is associated with many complications including male reproductive dysfunctions and infertility. Seahorse ( Hippocampus kuda) is a marine teleost fish well known for its beneficial effects on the reproductive system in traditional Chinese medicine books. Recently, several studies have been shown that the enzymatic hydrolysate of seahorse has multiple pharmacological activities. This study aimed to investigate the seahorse peptide hydrolysate (SH) ameliorative effects on the diabetic-induced male reproductive dysfunction in rat models. The in vivo studies were carried out with three different doses of SH (4, 8, and 20 mg/kg) and the diabetes condition was induced by administrating with streptozotocin (35 mg/kg) and fed a 40% high-fat diet. Seahorse hydrolysate (20 mg/kg) inhibited lipid peroxidation, increased antioxidant enzyme activity, and restored seminiferous tubules morphology in testis. Moreover, it improved reproductive dysfunction by increasing the level of testosterone, follicle-stimulating hormone, luteinizing hormone, sperm count, and motility. According to these results, we suggested that SH exhibited amelioration effects on the reproductive dysfunction.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Proteínas de Peixes , Hidrolisados de Proteína/uso terapêutico , Reprodução/efeitos dos fármacos , Smegmamorpha , Animais , Glicemia/efeitos dos fármacos , Glicemia/imunologia , Citocinas/imunologia , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/patologia , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Masculino , Estresse Oxidativo/efeitos dos fármacos , Hidrolisados de Proteína/farmacologia , Ratos Sprague-Dawley , Contagem de Espermatozoides , Motilidade Espermática/efeitos dos fármacos , Espermatozoides/anormalidades , Espermatozoides/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/patologia , Testosterona/sangue
20.
J Biol Chem ; 297(1): 100818, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34029592

RESUMO

The cleavage of the insulin receptor by ß-secretase 1 (BACE1) in the liver increases during diabetes, which contributes to reduce insulin receptor levels and impair insulin signaling. However, the precise signaling events that lead to this increased cleavage are unclear. We showed that BACE1 cleaves the insulin receptor in the early secretory pathway. Indeed, coimmunoprecipitation experiments reveal the interaction of the proforms of the two proteins. Moreover, fragments of insulin receptor are detected in the early secretory pathway and a mutated form of BACE1 that retains its prodomain cleaves an early secretory pathway-resident form of the insulin receptor. We showed that BACE1 proform levels are regulated by proteasome and/or lysosome-dependent degradation systems whose efficiencies are dependent on the O-GlcNacylation process. Our results showed that enhanced O-GlcNacylation reduces the efficiency of intracellular protein degradation systems, leading to the accumulation of the proform of BACE1 in the early secretory pathway where it cleaves the precursor of the insulin receptor. All these dysregulations are found in the livers of diabetic mice. In addition, we performed a screen of molecules according to their ability to increase levels of the insulin receptor at the surface of BACE1-overexpressing cells. This approach identified the aminosterol Claramine, which accelerated intracellular trafficking of the proform of BACE1 and increased autophagy. Both of these effects likely contribute to the reduced amount of the proform of BACE1 in the early secretory pathway, thereby reducing insulin receptor cleavage. These newly described properties of Claramine are consistent with its insulin sensitizing effect.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Colestanos/farmacologia , Receptor de Insulina/metabolismo , Espermina/análogos & derivados , Animais , Diabetes Mellitus Experimental/patologia , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Glicosilação/efeitos dos fármacos , Células HEK293 , Células Hep G2 , Humanos , Fígado/patologia , Modelos Biológicos , Ligação Proteica/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Proteostase/efeitos dos fármacos , Via Secretória/efeitos dos fármacos , Espermina/farmacologia , Ubiquitina/metabolismo , Ubiquitinação/efeitos dos fármacos
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