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1.
Nat Commun ; 11(1): 5162, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33056984

RESUMO

Bioactive natural C-glycosides are rare and chemical C-glycosylation faces challenges while enzymatic C-glycosylation catalyzed by C-glycosyltransferases provides an alternative way. However, only a small number of C-glycosyltransferases have been found, and most of the discovered C-glycosyltransferases prefer to glycosylate phenols with an acyl side chain. Here, a promiscuous C-glycosyltransferase, AbCGT, which is capable of C-glycosylating scaffolds lacking acyl groups, is identified from Aloe barbadensis. Based on the substrate promiscuity of AbCGT, 16 C-glycosides with inhibitory activity against sodium-dependent glucose transporters 2 are chemo-enzymatically synthesized. The C-glycoside 46a shows hypoglycemic activity in diabetic mice and is biosynthesized with a cumulative yield on the 3.95 g L‒1 scale. In addition, the key residues involved in the catalytic selectivity of AbCGT are explored. These findings suggest that AbCGT is a powerful tool in the synthesis of lead compounds for drug discovery and an example for engineering the catalytic selectivity of C-glycosyltransferases.


Assuntos
Aloe/enzimologia , Glicosídeos/biossíntese , Glicosiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/metabolismo , Aloxano/toxicidade , Aloe/genética , Animais , Biocatálise , Glicemia/análise , Glicemia/efeitos dos fármacos , Clonagem Molecular , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/tratamento farmacológico , Descoberta de Drogas/métodos , Feminino , Glicosídeos/farmacologia , Glicosídeos/uso terapêutico , Glicosilação , Glicosiltransferases/genética , Glicosiltransferases/isolamento & purificação , Humanos , Masculino , Camundongos , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Transportador 2 de Glucose-Sódio/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Especificidade por Substrato
2.
PLoS One ; 15(9): e0238727, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941450

RESUMO

PURPOSE: Female mice have been found to be resistant to streptozotocin (STZ)-induced diabetes, and pre-clinical research related to diabetic complications commonly omits females. The purpose of this study was to develop a method to induce diabetes in female mice, and to determine if retinas of diabetic female mice develop molecular changes and histopathological abnormalities comparable to those which develop in male diabetic mice. METHODS: To induce diabetes, animals of both sexes received daily intraperitoneal (i.p.) injection of STZ for 5 consecutive days at 55 mg/kg BW (a dose that is known to induce diabetes in male mice) or for females, 75 mg/kg BW of STZ. Retinal abnormalities that have been implicated in the development of the retinopathy (superoxide generation and expression of inflammatory proteins, iNOS and ICAM-1) were evaluated at 2 months of diabetes, and retinal capillary degeneration was evaluated at 8 months of diabetes. RESULTS: Daily i.p. injection of STZ for 5 consecutive days at a concentration of 55 mg/kg BW was sufficient to induce diabetes in 100% of male mice, but only 33% of female mice. However, females did become hyperglycemic when the dose of STZ administered was increased to 75 mg/kg BW. The resulting STZ-induced hyperglycemia in female and male mice was sustained for at least 8 months. After induction of the diabetes, both sexes responded similarly with respect to the oxidative stress, expression of iNOS, and degeneration of retinal capillaries, but differed in the limited population evaluated with respect to expression of ICAM-1. CONCLUSIONS: The resistance of female mice to STZ-induced diabetes can be overcome by increasing the dose of STZ used. Female mice can, and should, be included in pre-clinical studies of diabetes and its complications.


Assuntos
Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/fisiopatologia , Retinopatia Diabética/patologia , Retinopatia Diabética/fisiopatologia , Modelos Animais de Doenças , Caracteres Sexuais , Animais , Capilares/efeitos dos fármacos , Capilares/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Leucócitos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo II/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Retina/efeitos dos fármacos , Retina/patologia , Estreptozocina/farmacologia
3.
Life Sci ; 260: 118373, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898530

RESUMO

AIMS: Endoplasmic reticulum stress (ERS) as an emerging factor is involved in insulin resistance (IR), which is the pathological basis of diabetes mellitus. Accumulation of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase is associated with IR, but the underlying mechanisms have not been elucidated. This study was to reveal the important role of ADMA in IR and determine whether endogenous ADMA accumulation contributes to hepatic IR via ERS in diabetic rats and hepatocytes. MATERIALS AND METHODS: Diabetic rat model was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg). Phosphorylation of insulin receptor substrate 1 (IRS1) and protein kinase B (Akt) was detected to evaluate IR. The protein kinase PKR-like ER kinase (PERK) and eukaryotic initiation factor 2α kinase (eIF2α) phosphorylation, x-box binding protein-1 (XBP-1) splicing, glucose-regulated protein 78 (GRP78) and C/EBP homologues protein (CHOP) expressions were measured to assess ERS. KEY FINDINGS: Endogenous ADMA content was significantly increased and positively correlated with either IR as evidenced by increased IRS1 at serine and reduced Akt phosphorylation or ERS as indicated by upregulations of PERK and eIF2α phosphorylation, XBP-1 splicing, GRP78 and CHOP expressions in the liver of diabetic rats compared with control rats. Exogenous ADMA directly caused IR and ERS in dose- and time-dependent manners in primary mouse hepatocytes. Pretreatment with ERS inhibitor 4-phenylbutyrate or ADMA antagonist L-arginine not only improved ADMA-associated or -induced hepatic IR but also attenuated ADMA-associated or -induced ERS in diabetic rats or hepatocytes. SIGNIFICANCE: These findings indicate that endogenous ADMA accumulation contributes to hepatic IR via ERS in diabetic rats.


Assuntos
Arginina/análogos & derivados , Diabetes Mellitus Experimental/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Intolerância à Glucose/patologia , Resistência à Insulina , Insulina/metabolismo , Fígado/patologia , Animais , Apoptose , Arginina/toxicidade , Diabetes Mellitus Experimental/induzido quimicamente , Intolerância à Glucose/induzido quimicamente , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
4.
Ecotoxicol Environ Saf ; 205: 111154, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32810643

RESUMO

The study focused on the toxicological effect of Di-n-butyl phthalate (DBP) on the expression of Phosphorylated signal transducer and activator of transcription 1 (pSTAT1) -regulated Forkhead box protein M1 (FoxM1), which might provide a new understanding of gestational diabetes mellitus (GDM) development and a potential target for treatment. Streptozotocin (STZ) (40 mg/kg) was introduced in maternal rats by intraperitoneal injection on gestation day 0 (GD 0) in the STZ and STZ + DBP groups. DBP was introduced in maternal rats by oral feeding in the STZ + DBP group over the following 3 days (750 mg/kg/day). The changes in fasting blood glucose level in rats were detected on GD 1 and GD 5. The insulin levels in maternal rats and PIBCs were measured on GD 18. The Oral Glucose Tolerance Test (OGTT) test was performed on GD 18 to check the stability of the GDM model. The primary islet ß cells (PIBCs) were established for in vitro experiments. We examined the FoxM1 and pSTAT1 expression in pancreas by immunohistochemistry. Real-time PCR and Western blot were used to detect the pSTAR1 and FoxM1 protein and mRNA gene expression levels in PIBCs. Cell Counting Kit-8 (CCK-8) and flow cytometric analysis was used to test the viability and apoptosis of cells. The results showed that the STZ + DBP group had higher glucose and lower insulin secretion levels than the other groups by both fasting test and OGTT. FoxM1 was significantly suppressed while pSTAT1 was highly expressed after DBP exposure. FoxM1 could be regulated by pSTAT1. DBP can influence the progression of GDM through its toxicological effect, which significantly increases the expression of pSTAT1 and suppresses FoxM1, causing a decline in ß cell viability.


Assuntos
Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Gestacional/induzido quimicamente , Dibutilftalato/toxicidade , Disruptores Endócrinos/toxicidade , Proteína Forkhead Box M1/metabolismo , Exposição Materna/efeitos adversos , Fator de Transcrição STAT1/metabolismo , Animais , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Diabetes Gestacional/metabolismo , Feminino , Proteína Forkhead Box M1/genética , Expressão Gênica/efeitos dos fármacos , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Fosforilação , Gravidez , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley , Fator de Transcrição STAT1/genética , Transdução de Sinais
5.
PLoS One ; 15(8): e0237660, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841254

RESUMO

This study evaluated the influence of type 2 diabetes mellitus on bone loss, bone repair and cytokine production in hyperglycemic rats, treated or not with metformin. The animals were distributed as follow: Non-Hyperglycemic (NH), Non Hyperglycemic with Ligature (NH-L), Treated Non Hyperglycemic (TNH), Treated Non Hyperglycemic with Ligature Treated (TNH-L), Hyperglycemic (H), Treated Hyperglycemic (TH), Hyperglycemic with Ligature (H-L), Treated Hyperglycemic with Ligature (TH-L). At 40th day after induction of hyperglycemia, the groups NH-L, TNH-L, H-L, TH-L received a ligature to induce periodontitis. On the 69th, the TNH, TNH-L, TH, TH-L groups received metformin until the end of the study. Bone repair was evaluated at histometric and the expression levels of Sox9, RunX2 and Osterix. Analysis of the ex-vivo expression of TNF-α, IFN-γ, IL-12, IL-4, TGF-ß, IL-10, IL-6 and IL-17 were also evaluated. Metformin partially reverse induced bone loss in NH and H animals. Lower OPG/RANKL, increased OCN and TRAP expression were observed in hyperglycemic animals, and treatment with metformin partially reversed hyperglycemia on the OPG/RANKL, OPN and TRAP expression in the periodontitis. The expression of SOX9 and RunX2 were also decreased by hyperglycemia and metformin treatment. Increased ex vivo levels of TNF-α, IL-6, IL-4, IL-10 and IL-17 was observed. Hyperglycemia promoted increased IL-10 levels compared to non-hyperglycemic ones. Treatment of NH with metformin was able to mediate increased levels of TNF-α, IL-10 and IL-17, whereas for H an increase of TNF-α and IL-17 was detected in the 24- or 48-hour after stimulation with LPS. Ligature was able to induce increased levels of TNF-α and IL-17 in both NH and H. This study revealed the negative impact of hyperglycemia and/or treatment with metformin in the bone repair via inhibition of transcription factors associated with osteoblastic differentiation.


Assuntos
Perda do Osso Alveolar/prevenção & controle , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Hiperglicemia/complicações , Metformina/administração & dosagem , Periodontite/prevenção & controle , Perda do Osso Alveolar/etiologia , Perda do Osso Alveolar/metabolismo , Processo Alveolar/citologia , Processo Alveolar/efeitos dos fármacos , Processo Alveolar/metabolismo , Processo Alveolar/patologia , Animais , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/genética , Diferenciação Celular/efeitos dos fármacos , Citocinas/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/induzido quimicamente , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Hiperglicemia/induzido quimicamente , Hiperglicemia/tratamento farmacológico , Hiperglicemia/metabolismo , Osteoblastos/fisiologia , Periodontite/etiologia , Periodontite/metabolismo , Ratos , Estreptozocina/toxicidade , Fatores de Transcrição/metabolismo
6.
Gene ; 761: 145036, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32777525

RESUMO

Lupinus albus γ-conglutin is proposed to positively affect glucose metabolism through inhibition of hepatic glucose production and insulin-mimetic activity; however, the action mechanism is not entirely known. Besides, most studies had focused on its effect on molecular targets directly related to glucose metabolism, and few studies have investigated how γ-conglutin may affect the liver gene expression or if it plays a role in other metabolic processes. Therefore, we investigated the influence of γ-conglutin on the liver transcriptome of streptozotocin-induced diabetic rats using DNA microarrays, ontological analyses, and quantitative PCR. Of the 22,000 genes evaluated, 803 and 173 were downregulated and upregulated, respectively. The ontological analyses of the differentially expressed genes revealed that among others, the mitochondria, microtubules, cytoskeleton, and oxidoreductase activity terms were enriched, implying a possible role of γ-conglutin on autophagy. To corroborate the microarray results, we selected and quantified, by PCR, the expression of two genes associated with autophagy (Atg7 and Snx18) and found their expression augmented two and threefold, respectively; indicating a higher autophagy activity in animals treated with γ-conglutin. Although complementary studies are required, our findings indicate for the first time that the hypoglycaemic effects of γ-conglutin may involve an autophagy induction mechanism, a pivotal process for the preservation of cell physiology and glucose homeostasis.


Assuntos
Colectinas/farmacologia , Lupinus/metabolismo , Soroglobulinas/farmacologia , Transcriptoma/genética , Animais , Glicemia/metabolismo , Colectinas/metabolismo , Colectinas/fisiologia , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Insulina/metabolismo , Fígado/metabolismo , Fígado/patologia , Lupinus/genética , Masculino , Proteínas de Plantas/genética , Ratos , Ratos Wistar , Sementes/metabolismo , Soroglobulinas/metabolismo , Soroglobulinas/fisiologia
7.
Eur. j. anat ; 24(4): 263-267, jul. 2020. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-193957

RESUMO

The sphenopalatine ganglion occupies a special place in neuropathology and dental neuropathy, accompanied by such pronounced symptoms as "vegetative storm". The aim of the research was obtaining information on the external structure of the sphenopalatine ganglion, the morphometric characteristics of its neurons in norm and in experimental diabetes. The study was carried out on male Wistar rats weighing 260-300 g: with a stereoscopic biological microscope, using ophthalmic instruments, we removed almost the entire gland that was not accompanied by significant bleeding under general anesthesia. Peculiarities of the external structure of the sphenopalatine ganglion of the white rat were studied by macro-micro preparations under a binocular microscope at 50 objects pervaded with silver nitrate, according to Christen-sen


No disponible


Assuntos
Animais , Masculino , Ratos , Doenças Metabólicas/induzido quimicamente , Diabetes Mellitus Experimental/induzido quimicamente , Fossa Pterigopalatina/anatomia & histologia , Osso Esfenoide/anatomia & histologia , Ratos Wistar , Doenças Metabólicas/fisiopatologia , Modelos Animais , Fossa Pterigopalatina/metabolismo , Nitrato de Prata/efeitos adversos , Gânglio Geniculado/anatomia & histologia , Gânglio Geniculado/efeitos dos fármacos
8.
Food Chem ; 333: 127506, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679417

RESUMO

Artichoke floral stems (AFS) food waste by-products were examined for their phytochemical constituents and their in vitro and in vivo biological activities. Although that the highest total phenol content and total flavonoid content were found in ethyl acetate extract, methanol extract possessed the strongest DPPH and ABTS radical scavenging activity, and showed the highest reducing ferric antioxidant power (FRAP). The anti-acetylcholinesterase activity was higher in butanol extract, whereas the ethyl acetate extract had the highest inhibitory effect on heat-induced protein denaturation. In alloxan-induced diabetic mice, the AFS methanol extract (AFSE) rich in caffeoylquinic acids and flavones reduced blood glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, creatinine, and improved liver, and renal antioxidative status. Administration of AFSE to diabetic mice reduced total cholesterol, triglycerides, LDL-cholesterol, and the atherogenic index of plasma (AIP) suggesting its hypolipidemic action. Overall, AFS could be considered as attractive source of health-promoting ingredients.


Assuntos
Cynara scolymus/química , Compostos Fitoquímicos/análise , Extratos Vegetais/química , Alanina Transaminase , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Bactérias/efeitos dos fármacos , Glicemia/análise , Candida albicans/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Cynara scolymus/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/patologia , Flavonoides/análise , Flores/química , Flores/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Fenóis/análise , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/farmacologia , Caules de Planta/química , Caules de Planta/metabolismo , Espectrometria de Massas por Ionização por Electrospray
9.
PLoS One ; 15(6): e0235221, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32584888

RESUMO

Ficus krishnae stem bark and leaves are used for diabetes treatment in traditional medicines. Stem bark of F. krishnae was sequentially extracted with hexane, methanol and water, and these extracts were tested for their antihyperglyceamic activity by oral glucose tolerance test (OGTT) in overnight fasted glucose loaded normal rats. Hexane extract showed significant glucose lowering activity in OGTT, and the triterpene alcohols (cycloartenol+24-methylenecycloartanol) (CA+24-MCA) were isolated together from it by activity guided isolation and characterized by NMR and mass spectroscopy. The ratio of the chemical constituents CA and 24-MCA in (CA+24-MCA) was determined as 2.27:1.00 by chemical derivatization and gas chromatographic quantification. (CA+24-MCA) in high fat diet-streptozotocin induced type II diabetic rats showed significant antidiabetes activity at 1 mg/kg and ameliorated derailed blood glucose and other serum biochemical parameters. Cytoprotective activity of (CA+24-MCA) from glucose toxicity was evaluated in cultured RIN-5F cells by MTT assay and fluorescent microscopy. (CA+24-MCA) in in vitro studies showed enhanced cell viability in RIN-5F cells and significant protection of beta cells from glucose toxicity. Both in in vivo and in vitro studies (CA+24-MCA) showed enhancement in insulin release from the beta cells. In short term toxicity studies in mice (CA+24-MCA) did not show any conspicuous toxic symptoms. The combination of the phytosterols (CA+24-MCA) obtained through activity guided isolation of the stem bark of F. krishnae showed significant activity, and therefore is a promising candidate for new generation antidiabetes drug development.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Ficus/química , Hipoglicemiantes/uso terapêutico , Fitosteróis/química , Triterpenos/química , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Ficus/metabolismo , Teste de Tolerância a Glucose , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Conformação Molecular , Fitosteróis/isolamento & purificação , Fitosteróis/uso terapêutico , Caules de Planta/química , Caules de Planta/metabolismo , Ratos , Ratos Wistar , Triterpenos/isolamento & purificação , Triterpenos/uso terapêutico
10.
Zhongguo Zhen Jiu ; 40(6): 629-34, 2020 Jun 12.
Artigo em Chinês | MEDLINE | ID: mdl-32538015

RESUMO

OBJECTIVE: To explore the effects of electroacupuncture (EA) on skeletal muscle and blood glucose in rats with diabetic amyotrophy. METHODS: Among 40 SD rats, 10 rats were randomly selected into the control group and received no treatment. The remaining 30 rats were treated with intraperitoneal injection of streptozotocin (STZ, 60 mg/kg) to establish diabetes mellitus (DM) model, and then the rats were treated with vascular ligation at right posterior limb to establish amyotrophy model. The rats with diabetic amyotrophy were randomly divided into a model group and an EA group, 10 rats in each group (10 rats were excluded due to unsuccessful model establishment and death). The rats in the EA group was treated with EA at right-side "Yishu (EX-B 3)" "Shenshu (BL 23)" "Zusanli (ST 36)" and "Sanyinjiao (SP 6)", disperse-dense wave, 2 Hz/ 15 Hz, 20 minutes each time, once a day for 3 weeks. Before and after EA treatment, the blood sample was collected from inner canthus and the "glucose oxidase-peroxidase" method was used to detect fasting blood glucose level; ELISA method was used to detect insulin content. At the end of the treatment, HE staining method was used to observe the morphology of ischemic skeletal muscle in the right hindlimb; the real-time PCR method was used to detect the mRNA expression of muscle atrophy F-box (MAFbx), muscle ring finger-1 (MuRF1) and forkhead box O3a (FOXO3a) in the ischemic skeletal muscle tissue of right hindlimb. RESULTS: Before the treatment, the body mass in the model group and EA group was lower than that in the control group (P<0.01); after the treatment, the body mass in the control group was increased, while the body mass in the model group and EA group was decreased (P<0.01). Compared with the control group, the fasting blood glucose was significantly increased and insulin content was significantly decreased in the model group (P<0.01); compared with the model group, the fasting blood glucose was significantly decreased and the insulin content was significantly increased in the EA group after treatment (P<0.01). The muscle fibers of the model group were obviously broken, the number of the nuclei decreased, and the nuclei shrinked or even dissolved; the morphology of the muscle tissue of the EA group after intervention was improved compared with the model group. Compared with the control group, the cross-sectional area of ischemic skeletal muscle cells in the right hindlimb in the model group was decreased (P<0.01); compared with the model group, the cross-sectional area of ischemic skeletal muscle cells in the right hindlimb was increased in EA group (P<0.05). Compared with the control group, the levels of MAFbx, MuRF1 and FOXO3a mRNA in the right hindlimb ischemic skeletal muscle in the model group were increased significantly (P<0.01, P<0.05); compared with the model group, the levels of MAFbx, MuRF1 and FOXO3a mRNA in the EA group were decreased significantly (P<0.05, P<0.01). CONCLUSION: EA may play a role in the treatment of diabetic amyotrophy by inducing FOXO3a to reduce the transcription of MAFbx and MuRF1.


Assuntos
Glicemia , Neuropatias Diabéticas/terapia , Eletroacupuntura , Músculo Esquelético/fisiologia , Pontos de Acupuntura , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/terapia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
11.
Vascul Pharmacol ; 131: 106761, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32585189

RESUMO

AIMS: Diabetes-induced retinal vascular cell death aggravates diabetic retinopathy (DR) to the proliferative stage and blindness. Pericytes play a crucial role in retinal capillaries survival, stability, and angiogenesis. Ephrin-B2 is a tyrosine kinase that regulates pericytes/endothelial cells communication during angiogenesis; yet, its role in DR is still unclear. We hypothesize that diabetes increases Ephrin-B2 signaling in pericytes, which contributes to inflammation and retinal vascular cell death. METHODS: Selective inhibition of the Ephrin-B2 expression in the retinal pericytes was achieved using an intraocular injection of adeno-associated virus (AAV) with a specific pericyte promotor. Vascular death was determined by retinal trypsin digest. Pathological angiogenesis was assessed using the oxygen-induced retinopathy model in pericyte-Ephrin-B2 knockout mice, wild type, and wild type injected with AAV. Angiogenic properties, inflammatory, and apoptotic markers were measured in human retinal pericytes (HRP) grown under diabetic conditions. KEY FINDING: Diabetes significantly increased the expression of Ephrin-B2, inflammatory, and apoptotic markers in the diabetic retinas and HRP. These effects were prevented by silencing Ephrin-B2 in HRP. Moreover, Ephrin-B2 silencing in retinal pericytes decreased pathological angiogenesis and acellular capillaries formation in diabetic retinas. SIGNIFICANCE: Increased Ephrin-B2 expression in the pericytes contributed to diabetes-induced retinal inflammation and vascular death. These results identify pericytes-Ephrin-B2 as a therapeutic target for DR.


Assuntos
Apoptose , Retinopatia Diabética/metabolismo , Efrina-B2/metabolismo , Pericitos/metabolismo , Neovascularização Retiniana/metabolismo , Vasos Retinianos/metabolismo , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Retinopatia Diabética/etiologia , Retinopatia Diabética/genética , Retinopatia Diabética/patologia , Efrina-B2/deficiência , Efrina-B2/genética , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pericitos/patologia , Ratos Wistar , Neovascularização Retiniana/etiologia , Neovascularização Retiniana/genética , Neovascularização Retiniana/patologia , Vasos Retinianos/patologia , Transdução de Sinais , Estreptozocina
12.
J Med Chem ; 63(11): 6134-6143, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32406685

RESUMO

Native insulin is susceptible to biophysical aggregation and fibril formation, promoted by manual agitation and elevated temperatures. The safety of the drug and its application to alternative forms of administration could be enhanced through the identification of chemical modifications that strengthen its physical stability without compromising its biological properties. Complex polysialic acids (PSAs) exist naturally and provide a means to enhance the physical properties of peptide therapeutics. A set of insulin analogues site-specifically derivatized with sialic acid were prepared in an overall yield of 50-60%. Addition of a single or multiple sialic acids conferred remarkable enhancement to the biophysical stability of human insulin while maintaining its potency. The time to the onset of fibrillation was extended by more than 10-fold relative to that of the native hormone. These results demonstrate that simplified sialic acid conjugates represent a viable alternative to complex natural PSAs in increasing the stability of therapeutic peptides.


Assuntos
Insulina/análogos & derivados , Ácido N-Acetilneuramínico/química , Animais , Glicemia/análise , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Células HEK293 , Humanos , Insulina/farmacocinética , Insulina/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oligopeptídeos/síntese química , Oligopeptídeos/química , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Ácidos Siálicos/química , Equivalência Terapêutica
13.
Acta Cir Bras ; 35(1): e202000106, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236320

RESUMO

PURPOSE: To explore the role of all-trans retinoic acid (ATRA) in renal ischemia/reperfusion injury of diabetic rats. METHODS: Sixty adult male rats were randomly divided into 6 groups, including sham group (S group), ischemia-reperfusion group (I/R group), ischemia-reperfusion+ATRA group (A group), diabetic group (D group), diabetic ischemia-reperfusion group (DI/R group), diabetic ischemia-reperfusion +ATRA group (DA group). The levels of creatinine (Cr), cystatin C (Cys-C) and ß2-microglobulin (ß2-MG) were measured. Morphology of renal tissue was observed under light microscope. RESULTS: DJ-1, Nrf2, HO-1 and caspase-3 were detected by western blot. DJ-1, Nrf2, HO-1 and caspase-3 in I/R group, D group and DI/R group was higher than that in S group. Compared with I/R group, Nrf2 and HO-1 in A group was decreased, but caspase-3 was increased. However, Nrf2 in DA group was higher than that in DI/R group, HO-1 and caspase-3 in DA group were lower than that in DI/R group. Compared with group S, Cr, Cys-C and ß2-MG in I/R group, A group, D group, and DI/R group were higher. Whereas the levels of Cr, Cys-C, ß2-MG and renal injury score in DA group were lower than those in DI/R group. CONCLUSION: ATRA has a protective effect on renal ischemia-reperfusion injury in diabetic rats, maybe relating to DJ/Nrf2 pathway.


Assuntos
Diabetes Mellitus Experimental/induzido quimicamente , Rim/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/uso terapêutico , Traumatismo por Reperfusão/prevenção & controle , Tretinoína/uso terapêutico , Animais , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Rim/patologia , Masculino , Fator 2 Relacionado a NF-E2/farmacologia , Ratos , Traumatismo por Reperfusão/patologia , Estreptozocina , Tretinoína/farmacologia
14.
Plast Reconstr Surg ; 145(5): 942e-950e, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32332536

RESUMO

BACKGROUND: Chronic inflammation associated with delayed diabetic wound healing is induced by disturbed polarization of macrophages derived mainly from predisposed progenitor cells in bone marrow. Docosahexaenoic acid plays a critical role in regulating the function of macrophage progenitor cells. The authors evaluated whether docosahexaenoic acid accelerates diabetic wound healing in rats. METHODS: Streptozotocin-induced diabetic rats divided into control and docosahexaenoic acid-treated groups (n = 10) were subjected to paired dorsal skin wounds. Docosahexaenoic acid (100 mg/kg per day) was orally supplemented 2 weeks before wounding until termination. The wound healing process was recorded 0, 7, and 14 days after wounding. At day 7, blood perfusion was measured by laser Doppler perfusion imaging; angiogenesis was compared using immunofluorescent CD31 and α-smooth muscle actin staining; macrophage polarization was detected using immunofluorescence for CD68, CD206, and inducible nitric oxide synthase. Hematoxylin and eosin staining was used to examine wound healing at day 14. Activation status of macrophages derived from bone marrow cells in normal, diabetic, and docosahexaenoic acid-treated diabetic rats was determined in vitro using Western blotting and enzyme-linked immunosorbent assay. RESULTS: Docosahexaenoic acid significantly accelerated wound healing 7 and 14 days (p < 0.01) after wounding. Increased vessel densities (1.96-fold; p < 0.001) and blood perfusion (2.56-fold; p < 0.001) were observed in docosahexaenoic acid-treated wounds. Immunofluorescence revealed more CD206 and fewer inducible nitric oxide synthase-positive macrophages (p < 0.001) in treated wounds. Furthermore, macrophages derived from diabetic rats expressed higher levels of inducible nitric oxide synthase and tumor necrosis factor-α and lower arginase-1 and interleukin-10 (p < 0.05). CONCLUSION: Docosahexaenoic acid accelerates diabetic wound healing at least in part by restoring impaired plasticity of macrophage progenitor cells.


Assuntos
Diabetes Mellitus Experimental/complicações , Ácidos Docosa-Hexaenoicos/administração & dosagem , Macrófagos/imunologia , Células-Tronco/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Administração Oral , Animais , Plasticidade Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Humanos , Masculino , Ratos , Pele/lesões , Células-Tronco/fisiologia , Estreptozocina/toxicidade , Fatores de Tempo , Cicatrização/imunologia
15.
Microvasc Res ; 130: 104009, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32333940

RESUMO

AIMS: The purpose of the present study was to investigate the possible role of TIPE2 on acute lung injury (ALI) induced by myocardial ischemia/reperfusion (MIR) in diabetic rats. METHODS: Sprague-Dawley (SD) rats were randomly separated into four groups: control+sham (C + sham); control+MIR (C + MIR); diabetes+sham (D + sham); diabetes+MIR (D + MIR). Diabetes was induced using streptozotocin. Eight weeks after diabetes induction, MIR was conducted. At 2 h after MIR, myocardial injury indices were assessed; arterial blood, bronchoalveolar lavage fluid (BALF) and lung tissues were collected for corresponding detection. RESULTS: Rats subjected to MIR showed serious ALI (estimated via pathological changes, lung injury score and Wet/Dry weight ratio), lung inflammation and pulmonary cell apoptosis compared with sham groups, especially in D + MIR group. Evaluation of protein expression in lung tissues showed that p-JNK and nuclear NF-κB p65 protein levels were higher in D + MIR group as compared with C + MIR group. Besides, either hyperglycemia or MIR can significantly upregulate TIPE2 protein levels. CONCLUSIONS: In conclusion, diabetic lungs are more susceptible to MIR. TIPE2 may involve in this pathological process, possibly through regulation of inflammation, oxidative stress and apoptosis.


Assuntos
Lesão Pulmonar Aguda/etiologia , Diabetes Mellitus Experimental/complicações , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Pulmão/metabolismo , Traumatismo por Reperfusão Miocárdica/complicações , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Apoptose , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Mediadores da Inflamação/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Pulmão/patologia , Masculino , Traumatismo por Reperfusão Miocárdica/metabolismo , Estresse Oxidativo , Fosforilação , Ratos Sprague-Dawley , Transdução de Sinais , Estreptozocina , Fator de Transcrição RelA/metabolismo
16.
Diabetes ; 69(6): 1264-1278, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32312869

RESUMO

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a neurotrophic factor widely expressed in mammalian tissues, and it exerts critical protective effects on neurons and other cell types in various disease models, such as those for diabetes. However, to date, the expression and roles of MANF in the cornea, with or without diabetic keratopathy (DK), remain unclear. Here, we demonstrate that MANF is abundantly expressed in normal corneal epithelial cells; however, MANF expression was significantly reduced in both unwounded and wounded corneal epithelium in streptozotocin-induced type 1 diabetic C57BL/6 mice. Recombinant human MANF significantly promoted normal and diabetic corneal epithelial wound healing and nerve regeneration. Furthermore, MANF inhibited hyperglycemia-induced endoplasmic reticulum (ER) stress and ER stress-mediated apoptosis. Attenuation of ER stress with 4-phenylbutyric acid (4-PBA) also ameliorated corneal epithelial closure and nerve regeneration. However, the beneficial effects of MANF and 4-PBA were abolished by an Akt inhibitor and Akt-specific small interfering RNA (siRNA). Finally, we reveal that the subconjunctival injection of MANF-specific siRNA prevents corneal epithelial wound healing and nerve regeneration. Our results provide important evidence that hyperglycemia-suppressed MANF expression may contribute to delayed corneal epithelial wound healing and impaired nerve regeneration by increasing ER stress, and MANF may be a useful therapeutic modality for treating DK.


Assuntos
Lesões da Córnea/patologia , Diabetes Mellitus Experimental/complicações , Fatores de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/farmacologia , Regeneração Nervosa/fisiologia , Cicatrização/fisiologia , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Estresse do Retículo Endoplasmático , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Humanos , Hiperglicemia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Crescimento Neural/administração & dosagem , Fatores de Crescimento Neural/genética , RNA Bacteriano , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacologia
17.
PLoS One ; 15(3): e0223461, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32182246

RESUMO

Monitoring of blood glucose is an invasive, painful and costly practice in diabetes. Consequently, the search for a more cost-effective (reagent-free), non-invasive and specific diabetes monitoring method is of great interest. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been used in diagnosis of several diseases, however, applications in the monitoring of diabetic treatment are just beginning to emerge. Here, we used ATR-FTIR spectroscopy to evaluate saliva of non-diabetic (ND), diabetic (D) and insulin-treated diabetic (D+I) rats to identify potential salivary biomarkers related to glucose monitoring. The spectrum of saliva of ND, D and D+I rats displayed several unique vibrational modes and from these, two vibrational modes were pre-validated as potential diagnostic biomarkers by ROC curve analysis with significant correlation with glycemia. Compared to the ND and D+I rats, classification of D rats was achieved with a sensitivity of 100%, and an average specificity of 93.33% and 100% using bands 1452 cm-1 and 836 cm-1, respectively. Moreover, 1452 cm-1 and 836 cm-1 spectral bands proved to be robust spectral biomarkers and highly correlated with glycemia (R2 of 0.801 and 0.788, P < 0.01, respectively). Both PCA-LDA and HCA classifications achieved an accuracy of 95.2%. Spectral salivary biomarkers discovered using univariate and multivariate analysis may provide a novel robust alternative for diabetes monitoring using a non-invasive and green technology.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Glucose/análise , Insulinas/uso terapêutico , Monitorização Fisiológica/métodos , Saliva/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Animais , Biomarcadores , Análise Custo-Benefício , Confiabilidade dos Dados , Diabetes Mellitus Experimental/induzido quimicamente , Análise Discriminante , Masculino , Análise de Componente Principal , Curva ROC , Ratos , Ratos Wistar , Sensibilidade e Especificidade , Estreptozocina/farmacologia
18.
Am J Physiol Renal Physiol ; 318(4): F1017-F1029, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32116017

RESUMO

Diabetic kidney disease is a worldwide epidemic, and therapies are incomplete. Clinical data suggest that improved renal outcomes by Na+-glucose cotransporter 2 inhibitor (SGLT2i) are partly beyond their antihyperglycemic effects; however, the mechanisms are still elusive. Here, we investigated the effect of the SGLT2i dapagliflozin (DAPA) in the prevention of elevated O-GlcNAcylation and tubular hypoxia as contributors of renal fibrosis. Type 1 diabetes was induced by streptozotocin in adult male Wistar rats. After the onset of diabetes, rats were treated for 6 wk with DAPA or DAPA combined with losartan (LOS). The effect of hyperglycemia was tested in HK-2 cells kept under normal or high glucose conditions. To test the effect of hypoxia, cells were kept in 1% O2 for 2 h. Cells were treated with DAPA or DAPA combined with LOS. DAPA slowed the loss of renal function, mitigated renal tubular injury markers (kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin), and reduced tubulointerstitial fibrosis. DAPA diminished high glucose-induced protein O-GlcNAcylation and moderated the tubular response to hypoxia through the hypoxia-inducible factor pathway. DAPA alone was as effective as combined treatment with LOS in all outcome parameters. These data highlight the role of ameliorated O-GlcNAcylation and diminished tubular hypoxia as important benefits of SGLT2i treatment. Our results support the link between glucose toxicity, tubular hypoxia, and fibrosis, a vicious trio that could be targeted by SGLT2i in kidney diseases of other origins as well.


Assuntos
Compostos Benzidrílicos/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Glucosídeos/farmacologia , Glicosilação/efeitos dos fármacos , Túbulos Renais Proximais/efeitos dos fármacos , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Hipóxia Celular , Linhagem Celular , Colágeno/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/metabolismo , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Fibronectinas/metabolismo , Fibrose , Humanos , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Masculino , Ratos Wistar , Estreptozocina
19.
Proc Natl Acad Sci U S A ; 117(14): 7990-8000, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32198206

RESUMO

Atrial fibrillation (AF) is prevalent in diabetes mellitus (DM); however, the basis for this is unknown. This study investigated AF susceptibility and atrial electrophysiology in type 1 diabetic Akita mice using in vivo intracardiac electrophysiology, high-resolution optical mapping in atrial preparations, and patch clamping in isolated atrial myocytes. qPCR and western blotting were used to assess ion channel expression. Akita mice were highly susceptible to AF in association with increased P-wave duration and slowed atrial conduction velocity. In a second model of type 1 DM, mice treated with streptozotocin (STZ) showed a similar increase in susceptibility to AF. Chronic insulin treatment reduced susceptibility and duration of AF and shortened P-wave duration in Akita mice. Atrial action potential (AP) morphology was altered in Akita mice due to a reduction in upstroke velocity and increases in AP duration. In Akita mice, atrial Na+ current (INa) and repolarizing K+ current (IK) carried by voltage gated K+ (Kv1.5) channels were reduced. The reduction in INa occurred in association with reduced expression of SCN5a and voltage gated Na+ (NaV1.5) channels as well as a shift in INa activation kinetics. Insulin potently and selectively increased INa in Akita mice without affecting IK Chronic insulin treatment increased INa in association with increased expression of NaV1.5. Acute insulin also increased INa, although to a smaller extent, due to enhanced insulin signaling via phosphatidylinositol 3,4,5-triphosphate (PIP3). Our study reveals a critical, selective role for insulin in regulating atrial INa, which impacts susceptibility to AF in type 1 DM.


Assuntos
Fibrilação Atrial/metabolismo , Remodelamento Atrial/fisiologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 1/complicações , Insulina/metabolismo , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Remodelamento Atrial/imunologia , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Modelos Animais de Doenças , Ecocardiografia , Eletrocardiografia , Átrios do Coração/citologia , Átrios do Coração/metabolismo , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Humanos , Insulina/administração & dosagem , Insulina/genética , Canal de Potássio Kv1.5/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Miócitos Cardíacos/fisiologia , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Técnicas de Patch-Clamp , Potássio/metabolismo , Cultura Primária de Células , Sódio/metabolismo , Estreptozocina/toxicidade
20.
Diabetes ; 69(5): 1042-1051, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139594

RESUMO

Diabetic keratopathy occurs in ∼70% of all people with diabetes. This study was designed to examine the effects of vitamin D receptor knockout (VDR-/-) and vitamin D deficiency (VDD) on corneal epithelial wound healing and nerve density in diabetic mice. Diabetes was induced using the low-dose streptozotocin method. Corneal epithelial wounds were created using an Algerbrush, and wound healing was monitored over time. Corneal nerve density was measured in unwounded mice. VDR-/- and VDD diabetic mice (diabetic for 8 and 20 weeks, respectively) had slower healing ratios than wild-type diabetic mice. VDR-/- and VDD diabetic mice also showed significantly decreased nerve density. Reduced wound healing ratios and nerve densities were not fully rescued by a supplemental diet rich in calcium, lactose, and phosphate. We conclude that VDR-/- and VDD significantly reduce both corneal epithelial wound healing and nerve density in diabetic mice. Because the supplemental diet did not rescue wound healing or nerve density, these effects are likely not specifically related to hypocalcemia. This work supports the hypothesis that low vitamin D levels can exacerbate preexisting ophthalmic conditions, such as diabetes.


Assuntos
Córnea/inervação , Diabetes Mellitus Experimental/metabolismo , Epitélio Anterior/patologia , Receptores de Calcitriol/genética , Deficiência de Vitamina D , Animais , Córnea/patologia , Lesões da Córnea , Diabetes Mellitus Experimental/induzido quimicamente , Feminino , Masculino , Camundongos , Camundongos Knockout , Receptores de Calcitriol/metabolismo , Vitamina D/análogos & derivados , Vitamina D/sangue , Cicatrização
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