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1.
Life Sci ; 279: 119693, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34111464

RESUMO

Nitrosative stress plays a critical role in retinal injury in high glucose (HG) environment of eye, but the mechanisms remain poorly understood. Here we tested the hypothesis that HG induced reactive nitrogen species (RNS) production acts as a key functional mediator of antioxidant depletion, mitochondrial dysfunction, biomolecule damage, inflammation and apoptosis. Our findings illustrated that exposure of cultured RGC-5 cells to HG significantly disrupts the antioxidant defense mechanism and mitochondrial machineries by increasing the loss of mitochondrial membrane potential (ΔÑ°M) and elevating mitochondrial mass. Furthermore, we used biochemical tools to analyze the changes in metabolites, sulfur amino acids (SAAs) such as L-glutathione (GSH) and L-cysteine (Cys), in the presence of HG environment. These metabolic changes were followed by an increase in glycolytic flux that is phosphofructokinase-2 (PFK-2) activity. Moreover, HG exposure results in a significant disruption of protein carbonylation (PC) and lipid peroxidation (LPO), downregulation of OGG1 and increase in 8-OHdG accumulations in RGC-5 cells. In addition, our results demonstrated that HG environment coinciding with increased expression of inflammatory mediators, cell cycle deregulation, decreased in cell viability and expression of FoxOs, increased lysosomal content leading to apoptosis. Pre-treatment of selective inhibitors of RNS significantly reduced the HG-induced cell cycle deregulation and apoptosis in RGC-5 cells. Collectively, these results illustrated that accumulated RNS exacerbates the antioxidant depletion, mitochondrial dysfunction, biomolecule damage, inflammation and apoptosis induced by HG exposure in RGC-5 cells. Treatment of pharmacological inhibitors attenuated the HG induced in retinal cells.


Assuntos
Apoptose , Diabetes Mellitus Experimental/fisiopatologia , Hiperglicemia/complicações , Inflamação/patologia , Mitocôndrias/patologia , Estresse Oxidativo , Espécies Reativas de Nitrogênio/metabolismo , Animais , Inflamação/etiologia , Inflamação/metabolismo , Peroxidação de Lipídeos , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais
2.
Life Sci ; 278: 119534, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33933461

RESUMO

Diabetes promotes renal sympathetic hyperactivity, autonomic imbalance, and cardiovascular and renal dysfunction. Bilateral renal denervation (BRD) has emerged as a treatment for diabetes; however, the mechanisms that underlie the beneficial effects of BRD are unknown. AIMS: The present study evaluated the effects of BRD on autonomic, cardiovascular, metabolic, and renal function in streptozotocin-diabetic rats. MAIN METHODS: Wistar rats were separated into three experimental groups: control (CTR), diabetic (DM), and diabetic that underwent BRD (DM BRD). BRD was performed two weeks after STZ-diabetes induction, the experiments were performed four weeks after DM induction. This study evaluated sympathetic vasomotor nerve activity in different territories (renal, lumbar and splanchnic), arterial baroreceptor reflex, metabolic and renal function. KEY FINDINGS: BRD significantly reduced glycemia, glycosuria, albuminuria, and SGLT2 gene expression in the kidney in DM rats. Renal sympathetic nerve activity (rSNA) was significantly increased and splanchnic sympathetic nerve activity (sSNA) was significantly decreased in DM rats, without changes in lumbar sympathetic nerve activity (lSNA). BRD was able to normalize sSNA and significantly increase lSNA in DM rats compared to control rats. Additionally, cardiac baroreceptor sensitivity was impaired in DM rats, and BRD significantly improved baroreflex sensitivity. SIGNIFICANCE: Our data suggest that renal nerves play an important role in autonomic, cardiovascular, and renal dysfunction in STZ-DM rats. Thus, sympathetic renal hyperactivity should be considered a possible therapeutic target in diabetic patients.


Assuntos
Sistema Cardiovascular , Denervação , Diabetes Mellitus Experimental/metabolismo , Rim/inervação , Rim/metabolismo , Animais , Barorreflexo , Pressão Sanguínea/efeitos dos fármacos , Cateterismo , Diabetes Mellitus Experimental/fisiopatologia , Coração , Frequência Cardíaca/efeitos dos fármacos , Hematócrito , Masculino , Pressorreceptores/fisiologia , Ratos , Ratos Wistar , Transportador 2 de Glucose-Sódio/metabolismo , Estreptozocina , Sistema Nervoso Simpático/efeitos dos fármacos
3.
Int J Mol Sci ; 22(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33921053

RESUMO

Tetracycline antibiotics act by inhibiting bacterial protein translation. Given the bacterial ancestry of mitochondria, we tested the hypothesis that doxycycline-which belongs to the tetracycline class-reduces mitochondrial function, and results in cardiac contractile dysfunction in cultured H9C2 cardiomyoblasts, adult rat cardiomyocytes, in Drosophila and in mice. Ampicillin and carbenicillin were used as control antibiotics since these do not interfere with mitochondrial translation. In line with its specific inhibitory effect on mitochondrial translation, doxycycline caused a mitonuclear protein imbalance in doxycycline-treated H9C2 cells, reduced maximal mitochondrial respiration, particularly with complex I substrates, and mitochondria appeared fragmented. Flux measurements using stable isotope tracers showed a shift away from OXPHOS towards glycolysis after doxycycline exposure. Cardiac contractility measurements in adult cardiomyocytes and Drosophila melanogaster hearts showed an increased diastolic calcium concentration, and a higher arrhythmicity index. Systolic and diastolic dysfunction were observed after exposure to doxycycline. Mice treated with doxycycline showed mitochondrial complex I dysfunction, reduced OXPHOS capacity and impaired diastolic function. Doxycycline exacerbated diastolic dysfunction and reduced ejection fraction in a diabetes mouse model vulnerable for metabolic derangements. We therefore conclude that doxycycline impairs mitochondrial function and causes cardiac dysfunction.


Assuntos
Antibacterianos/farmacologia , Doxiciclina/farmacologia , Mitocôndrias Cardíacas/metabolismo , Contração Miocárdica/efeitos dos fármacos , Envelhecimento/metabolismo , Animais , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Respiração Celular/efeitos dos fármacos , Citosol/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/fisiopatologia , Diástole/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/fisiologia , Complexo I de Transporte de Elétrons/metabolismo , Complexo II de Transporte de Elétrons/metabolismo , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Mitocôndrias Cardíacas/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Proteínas Nucleares/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Ratos
4.
Eur J Pharmacol ; 901: 174070, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33798598

RESUMO

The aim of this study was to investigate the reaction of pancreatic and mesenteric artery to 5-hydroxytryptamine (5-HT, serotonin) and the mechanism of nitric oxide in diabetes. Diabetic mice were induced by streptozotocin through intraperitoneal injection. The vascular tension of the pancreatic, mesenteric and brain basilar arteries in diabetic and control mice were measured by myograph in the applications of angiotensin II, 5-HT, 5-HT2A receptor agonist 2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI), 5-HT1B/1D receptor agonist sumatriptan, 5-HT2B receptor agonist BW723C86, 5-HT1D receptor antagonist Palonosetron and 5-HT2 receptor antagonist Sarpogrelate. The effect of 5-HT on arteries pretreated with L-NAME and sodium nitroprusside (SNP) on arteries pretreated with norepinephrine were measured. The mRNA expressions of eNOS, 5-HT1B, 5-HT1D, 5-HT2A and 5-HT2B in pancreatic and mesenteric arteries were measured by Real-time PCR. The concentration of 5-HT in plasma and eNOS in pancreatic and mesenteric arteries were tested. Our results showed that the tension of pancreatic and mesenteric arteries in diabetic mice impaired to 5-HT, but not Ang II, and to DOI and sumatriptan, but normalized by incubation with L-NAME. Pancreatic and mesenteric arteries showed no differences to SNP after pretreated with NE between diabetic and control mice. The mRNA of eNOS and 5-HT receptors in pancreatic and mesenteric artery showed no difference between control and diabetic mice. We conclude that the effect of 5-HT on the tension of pancreatic and mesenteric arteries decrease in diabetic mice. It may due to the decreased activity of 5-HT receptors and the activation of eNOS, which causes nitric oxide to release more and makes the tension of vessels decreased.


Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Artérias Mesentéricas/fisiopatologia , Pâncreas/fisiopatologia , Serotonina/fisiologia , Anfetaminas/farmacologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NG-Nitroarginina Metil Éster/farmacologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Norepinefrina , Receptor 5-HT2A de Serotonina/efeitos dos fármacos , Agonistas do Receptor 5-HT1 de Serotonina/farmacologia , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia
5.
Molecules ; 26(5)2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33801378

RESUMO

BACKGROUND: There is a growing interest in the correlation between antioxidants and periodontal disease. In this study, we aimed to investigate the effect of oxidative stress and the impact of two antioxidants, curcumin and rutin, respectively, in the etiopathology of experimentally induced periodontitis in diabetic rats. METHODS: Fifty Wistar albino rats were randomly divided into five groups and were induced with diabetes mellitus and periodontitis: (1) (CONTROL)-control group, (2) (DPP)-experimentally induced diabetes mellitus and periodontitis, (3) (DPC)-experimentally induced diabetes mellitus and periodontitis treated with curcumin (C), (4) (DPR)-experimentally induced diabetes mellitus and periodontitis treated with rutin (R) and (5) (DPCR)-experimentally induced diabetes mellitus and periodontitis treated with C and R. We evaluated malondialdehyde (MDA) as a biomarker of oxidative stress and reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG and catalase (CAT) as biomarkers of the antioxidant capacity in blood harvested from the animals we tested. The MDA levels and CAT activities were also evaluated in the gingival tissue. RESULTS: The control group effect was statistically significantly different from any other groups, regardless of whether or not the treatment was applied. There was also a significant difference between the untreated group and the three treatment groups for variables MDA, GSH, GSSG, GSH/GSSG and CAT. There was no significant difference in the mean effect for the MDA, GSH, GSSG, GSH/GSSG and CAT variables in the treated groups of rats with curcumin, rutin and the combination of curcumin and rutin. CONCLUSIONS: The oral administration of curcumin and rutin, single or combined, could reduce the oxidative stress and enhance the antioxidant status in hyperglycemic periodontitis rats.


Assuntos
Antioxidantes/farmacologia , Biomarcadores/análise , Curcumina/farmacologia , Diabetes Mellitus Experimental/fisiopatologia , Hiperglicemia/complicações , Estresse Oxidativo/efeitos dos fármacos , Periodontite/tratamento farmacológico , Rutina/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Masculino , Periodontite/etiologia , Periodontite/patologia , Ratos , Ratos Wistar
6.
Toxicol Appl Pharmacol ; 421: 115533, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33848515

RESUMO

Decreased activity of AMP-activated protein kinase (AMPK) is implicated in the pathogenesis of diabetic cardiomyopathy (DCM). Recent evidence suggests a crosstalk between cinacalcet and AMPK activation. This study investigated the effects of cinacalcet on cardiac remodeling and dysfunction in type 2 diabetic rats (T2DM). High fat diet for 4 weeks combined with single intraperitoneal injection of streptozotocin (30 mg/kg) was used to induce type 2 diabetes in rats. Diabetic rats were either orally treated with vehicle, 5 or 10 mg/kg cinacalcet for 4 weeks. Control rats were fed standard chow diet and intraperitoneally injected with citrate buffer. T2DM rats showed lower body weight (BW), hyperglycemia and dyslipidemia, along with increased heart weight (HW) and HW/BW ratio. Masson's trichrome stained cardiac sections revealed massive fibrosis in T2DM rats. There were increased TGF-ß1 and hydroxyproline levels, coupled with up-regulation of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in hearts of T2DM rats. These alterations were associated with redox imbalance and impaired cardiac functions. Decreased phosphorylation of AMPK at threonine172 residue was found in T2DM hearts. Cinacalcet for 4 weeks significantly activated AMPK and alleviated cardiac remodeling and dysfunction in a dose-dependent manner, without affecting blood glucose, serum calcium and phosphorus levels. Cinacalcet increased the mitochondrial DNA content, and expressions of PGC-1α, UCP-3, beclin-1 and LC3-II/LC3-I ratio. Cinacalcet decreased the pro-apoptotic Bax, while increased the anti-apoptotic Bcl-2 in cardiac tissue of T2DM rats. These findings might highlight cinacalcet as an alternative therapy to combat the development and progression of DCM.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/efeitos dos fármacos , Cinacalcete/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Cardiomiopatias Diabéticas/prevenção & controle , Mitocôndrias Cardíacas/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/induzido quimicamente , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/fisiopatologia , Cardiomiopatias Diabéticas/enzimologia , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/fisiopatologia , Fibrose , Hemodinâmica/efeitos dos fármacos , Masculino , Mitocôndrias Cardíacas/enzimologia , Mitocôndrias Cardíacas/patologia , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Transdução de Sinais , Estreptozocina
7.
Diabetes Res Clin Pract ; 176: 108790, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33812900

RESUMO

AIMS: The pathophysiological alteration of diabetic neuropathic pain (DNP) in brain is unclear. Here we aimed to explore the metabolomic characteristics of brain in rats over the progression of DNP through metabolomic analysis. METHODS: Adult rats were randomly divided into control group and DNP group. Body weight, blood glucose and behavioral assessment of neuropathic pain were measured every week after streptozotocin (STZ) injection. Finally, the brains of 2 rats from control group and 6 rats from DNP group were removed every 4 weeks after STZ injection for metabolomics analysis. RESULTS: After 4 weeks of STZ-injection, the rats with diabetes developed DNP, which was characterized as mechanical allodynia and thermal nociception. As for metabolomic analysis, differentially expressed metabolites (DE metabolites) showed a dynamic alteration over the development of DNP and affected several KEGG pathways associated with amino acid metabolism. Furthermore, the expression of l-Threonine, l-Methionine, d-Proline, l-Lysine and N-Acetyl-l-alanine were significantly decreased at all time points of DNP group. The amino acids which were precursor of analgesic neurotransmitters were downregulated over the progression of DNP, including l-tryptophan, l-histidine and l-tyrosine. CONCLUSIONS: The impairment of amino acid metabolism in brain might contribute to the progression of DNP through decreasing analgesic neurotransmitters.


Assuntos
Aminoácidos/metabolismo , Encéfalo/metabolismo , Diabetes Mellitus Experimental/metabolismo , Neuropatias Diabéticas/etiologia , Neuralgia/etiologia , Aminoácidos/análise , Aminoácidos/fisiologia , Animais , Química Encefálica/fisiologia , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/fisiopatologia , Neuropatias Diabéticas/metabolismo , Neuropatias Diabéticas/fisiopatologia , Hiperalgesia/complicações , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatologia , Masculino , Metabolômica , Neuralgia/metabolismo , Neuralgia/patologia , Ratos , Ratos Sprague-Dawley , Estreptozocina
8.
Biomed Pharmacother ; 137: 111370, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33761597

RESUMO

Diabetic gastroparesis (DG) exhibits delayed gastric emptying (GE) due to impaired gastric non-adrenergic, non-cholinergic (NANC) relaxation. These defects are due to loss or reduction of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) that causes reduced expression and/or dimerization of neuronal nitric oxide synthase alpha (nNOSα) gene expression and function. We investigated the effect of potent Nrf2 activators (cinnamaldehyde [CNM] & curcumin [CUR]) on GE in obesity-induced diabetic female mice. We fed adult female homozygous Nfe2l2-/- (Nrf2 KO) and wild-type (WT) female mice with either a high-fat diet (HFD) or a normal diet (ND) for a period of 16 weeks. Groups of HFD mice were fed with CUR or CNM either at 6th or 10th week respectively. Our results demonstrate that supplementation of CNM or CUR restored impaired nitrergic relaxation and attenuated delayed GE in HFD fed mice. Supplementation of CNM or CUR normalized altered gastric antrum protein expression of (1) p-ERK/p-JNK/MAPK/p-GSK-3ß, (2) BH4 (Cofactor of nNOS) biosynthesis enzyme GCH-1 and the GSH/GSSG ratio, (3) nNOSα protein & dimerization and soluble guanylate cyclase (sGC), (4) AhR and ER expression, (5) inflammatory cytokines (TNF α, IL-1ß, IL-6), (6)TLR-4, as well as (7) reduced oxidative stress markers in WT but not in Nrf2 KO obesity-induced chronic diabetic female mice. Immunoprecipitation experiments revealed an interaction between nNOS and Nrf2 proteins. Our results conclude that Nrf2 activation restores nitrergic-mediated gastric motility and GE by normalizing inflammation and oxidative stress induced by obesity-induced chronic diabetes.


Assuntos
Antioxidantes/farmacologia , Diabetes Mellitus Experimental/fisiopatologia , Dieta Hiperlipídica , Esvaziamento Gástrico/efeitos dos fármacos , Acroleína/análogos & derivados , Acroleína/farmacologia , Animais , Curcumina/farmacologia , Diabetes Mellitus Experimental/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Óxido Nítrico/fisiologia , Óxido Nítrico Sintase Tipo I/biossíntese , Estresse Oxidativo/efeitos dos fármacos , Antro Pilórico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Ganho de Peso/efeitos dos fármacos
9.
Am J Physiol Renal Physiol ; 320(5): F761-F771, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33645318

RESUMO

Inhibitors of the main proximal tubular Na-glucose cotransporter (SGLT2) mitigate diabetic glomerular hyperfiltration and have been approved by the United States Food and Drug Administration for slowing the progression of diabetic kidney disease. It has been proposed that SGLT2 inhibitors improve hard renal outcomes by reducing glomerular capillary pressure (PGC) via a tubuloglomerular feedback (TGF) response to a decrease in proximal reabsorption (Jprox). However, the effect of SGLT2 inhibition on PGC has not been measured. Here, we studied the effects of acute SGLT2 blockade (ertugliflozin) on Jprox and glomerular hemodynamics in two-period micropuncture experiments using streptozotocin-induced diabetic rats fed high- or low-NaCl diets. PGC was measured by direct capillary puncture or computed from tubular stop-flow pressure (PSF). TGF is intact while measuring PGC directly but rendered inoperative when measuring PSF. Acute SGLT2 inhibitor reduced Jprox by ∼30%, reduced PGC by 5-8 mmHg, and reduced glomerular filtration rate (GFR) by ∼25% (all P < 0.0001) but had no effect on PSF. The decrease in PGC was larger with the low-NaCl diet (8 vs. 5 mmHg, P = 0.04) where PGC was higher to begin with (54 vs. 50 mmHg, P = 0.003). Greater decreases in PGC corresponded, unexpectedly, to lesser decreases in GFR (P = 0.04). In conclusion, these results confirm expectations that PGC would decline in response to acute SGLT2 inhibition and that a functioning TGF system is required for this. We infer a contribution of postglomerular vasorelaxation to the TGF responses where decreases in PGC were large and decreases in GFR were small.NEW & NOTEWORTHY It has been theorized that Na-glucose cotransporter (SGLT2) blockade slows progression of diabetic kidney disease by reducing physical strain on the glomerulus. This is the first direct measurement of intraglomerular pressure during SGLT2 blockade. Findings confirmed that SGLT2 blockade does reduce glomerular capillary pressure, that this is mediated through tubuloglomerular feedback, and that the tubuloglomerular feedback response to SGLT2 blockade involves preglomerular vasoconstriction and postglomerular vasorelaxation.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Hemodinâmica/efeitos dos fármacos , Glomérulos Renais/irrigação sanguínea , Circulação Renal/efeitos dos fármacos , Cloreto de Sódio na Dieta/administração & dosagem , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/fisiopatologia , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/fisiopatologia , Dieta Hipossódica , Progressão da Doença , Taxa de Filtração Glomerular/efeitos dos fármacos , Masculino , Punções , Ratos Wistar , Reabsorção Renal/efeitos dos fármacos , Cloreto de Sódio na Dieta/metabolismo , Cloreto de Sódio na Dieta/toxicidade , Estreptozocina
10.
Oxid Med Cell Longev ; 2021: 1298657, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33728017

RESUMO

Background: Gastric electrical pacing (GEP) could restore interstitial cells of Cajal in diabetic rats. M2 macrophages contribute to the repair of interstitial cells of Cajal injury though secreting heme oxygenase-1 (HO-1). The aim of the study is to investigate the effects and mechanisms of gastric electrical pacing on M2 macrophages in diabetic models. Methods: Sixty male Sprague-Dawley rats were randomized into control, diabetic (DM), diabetic with the sham GEP (DM+SGEP), diabetic with GEP1 (5.5 cpm, 100 ms, 4 mA) (DM+GEP1), diabetic with GEP2 (5.5 cpm, 300 ms, 4 mA) (DM+GEP2), and diabetic with GEP3 (5.5 cpm, 550 ms, 4 mA) (DM+GEP3) groups. The apoptosis of interstitial cells of Cajal and the expression of macrophages were detected by immunofluorescence technique. The expression levels of the Nrf2/HO-1 and NF-κB pathway were evaluated using western blot analysis or immunohistochemical method. Malonaldehyde, superoxide dismutase, and reactive oxygen species were tested to reflect the level of oxidative stress. Results: Apoptosis of interstitial cells of Cajal was increased in the DM group but significantly decreased in the DM+GEP groups. The total number of macrophages was almost the same in each group. In the DM group, M1 macrophages were increased and M2 macrophages were decreased. However, M2 macrophages were dramatically increased and M1 macrophages were reduced in the DM+GEP groups. Gastric electrical pacing improved the Nrf2/HO-1 pathway and downregulated the phosphorylation of NF-κB. In the DM group, the levels of malonaldehyde and reactive oxygen species were elevated and superoxide dismutase was lowered, while gastric electrical pacing reduced the levels of malonaldehyde and reactive oxygen species and improved superoxide dismutase. Conclusion: Gastric electrical pacing reduces apoptosis of interstitial cells of Cajal though promoting M2 macrophages polarization to play an antioxidative stress effect in diabetic rats, which associates with the activated Nrf2/HO-1 pathway and the phosphorylation of NF-κB pathway.


Assuntos
Apoptose , Polaridade Celular , Diabetes Mellitus Experimental/fisiopatologia , Fenômenos Eletrofisiológicos , Células Intersticiais de Cajal/patologia , Macrófagos/patologia , Estresse Oxidativo , Estômago/fisiopatologia , Animais , Diabetes Mellitus Experimental/patologia , Eletroacupuntura , Heme Oxigenase-1/metabolismo , Masculino , Malondialdeído/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-kit/metabolismo , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Fator de Células-Tronco/metabolismo , Estômago/patologia , Superóxido Dismutase/metabolismo
11.
Life Sci ; 273: 119308, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33667520

RESUMO

AIMS: Brain-derived neurotrophic factor (BDNF) is vital in the pathogenesis of mechanical allodynia with a paucity of reports available regarding diabetic neuropathy pain (DNP). Herein we identified the involvement of BDNF in driving mechanical allodynia in DNP rats via the activation of transient receptor potential canonical 6 (TRPC6) channel. MATERIALS AND METHODS: The DNP rat model was established via streptozotocin (STZ) injection, and allodynia was assessed by paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL). The expression profiles of BDNF and TRPC6 in dorsal root ganglia (DRG) and spinal cord were illustrated by immunofluorescence and Western blotting. Intrathecal administration of K252a or TrkB-Fc was performed to inhibit BNDF/TrkB expression, and respective injection of GsMTX-4, BTP2 and TRPC6 antisense oligodeoxynucleotides (TRPC6-AS) was likewise conducted to inhibit TRPC6 expression in DNP rats. Calcium influx in DRG was monitored by calcium imaging. KEY FINDINGS: The time-dependent increase of BDNF and TRPC6 expression in DRG and spinal cord was observed since the 7th post-STZ day, correlated with the development of mechanical allodynia in DNP rats. Intrathecal administration of K252a, TrkB-Fc, GsMTX-4 and BTP2 prevented mechanical allodynia in DNP rats. Pre-treatment of TRPC6-AS reversed the BDNF-induced pain-like responses in DNP rats rather than the naïve rats. In addition, the TRPC6-AS reversed BDNF-induced increase of calcium influx in DRG neurons in DNP rats. SIGNIFICANCE: The intrathecal inhibition of TRPC6 alleviated the BDNF-induced mechanical allodynia in DNP rat model. This finding may validate the application of TRPC6 antagonists as interesting strategy for DNP management.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Neuropatias Diabéticas/complicações , Modelos Animais de Doenças , Hiperalgesia/etiologia , Neuralgia/complicações , Canais de Cátion TRPC/metabolismo , Animais , Comportamento Animal , Fator Neurotrófico Derivado do Encéfalo/administração & dosagem , Hiperalgesia/metabolismo , Hiperalgesia/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Canais de Cátion TRPC/genética
12.
Neurosci Lett ; 751: 135808, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33705936

RESUMO

Diabetes has been demonstrated to be one of the strongest predictors of risk for postoperative delirium and functional decline in older patients undergoing surgery. Exercise is often prescribed as a treatment for diabetic patients and regular physical activity is hypothesized to decrease the risk of postoperative cognitive impairments. Prior studies suggest that anesthetic emergence trajectories and recovery are predictive of risk for later postoperative cognitive impairments. Therapeutic strategies aimed at improving emergence and recovery from anesthesia may therefore be beneficial for diabetic patients. Wistar (n = 32) and Goto-Kakizaki (GK) type 2 diabetic (n = 32) rats between 3-4 months old underwent treadmill exercise for 30 min/day for ten days or remained inactive. Pre-anesthesia spontaneous alternation behavior was recorded with a Y-maze. Rats then received a 2-h exposure to 1.5-2 % isoflurane or oxygen only. The time to reach anesthetic emergence and post-anesthesia recovery behaviors was recorded for each rat. Postsynaptic density protein-95 (PSD-95), an important scaffolding protein required for synaptic plasticity, protein levels were quantified from hippocampus using western blot. Spontaneous alternation behavior (p = 0.044) and arm entries (p < 0.001) were decreased in GK rats. There was no difference between groups in emergence times from isoflurane, but exercise hastened the recovery time (p = 0.008) for both Wistar and GK rats. Following 10 days of exercise, both Wistar and GK rats show increased levels of PSD-95 in the hippocampus. Prehabilitation with moderate intensity exercise, even on a short timescale, is beneficial for recovery from isoflurane in rats, regardless of metabolic disease status.


Assuntos
Anestésicos Inalatórios/efeitos adversos , Recuperação Demorada da Anestesia/prevenção & controle , Diabetes Mellitus Experimental/fisiopatologia , Isoflurano/efeitos adversos , Condicionamento Físico Animal/métodos , Animais , Diabetes Mellitus Experimental/metabolismo , Proteína 4 Homóloga a Disks-Large/metabolismo , Hipocampo/metabolismo , Masculino , Exercício Pré-Operatório , Ratos , Ratos Wistar
13.
Mol Med Rep ; 23(4)2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33576435

RESUMO

Insulin resistance is one of important factors causing type 2 diabetes; therefore, regulating insulin sensitivity is considered a beneficial therapeutic approach against type 2 diabetes. The present study aimed to determine the effects of N1­methylnicotinamide (MNAM) on insulin resistance (IR) in skeletal muscle from a mouse model of type 2 diabetes mellitus (T2DM), and to investigate the regulatory mechanisms of the sirtuin 1 (SIRT1)/peroxisome proliferator­activated receptor γ coactivator­1α (PGC­1α) signaling pathway. C57BL/6 mice were fed a normal diet with or without 1% MNAM and ob/ob mice were also fed a normal diet with or without 0.3 or 1% MNAM. Blood glucose, insulin levels, insulin resistance (IR), sensitivity indices and triglyceride (TG) content were detected using ELISAs. The expression of gluconeogenesis­related, insulin signaling­related and SIRT1/PGC­1α pathway­related proteins was analyzed using reverse transcription­quantitative PCR (RT­qPCR) and western blotting. In vitro, C2C12 cells were used to establish an IR muscle cell model by 0.75 mM palmitic acid (PA) treatment (PA group). The IR cell model was subsequently supplemented with 1 mM MNAM (PM group) or 1 mM MNAM + 30 µM SIRT1 inhibitor, EX527 (PME group). After treatment the glucose levels and insulin signaling­related proteins were detected by ELISAs and western blotting, respectively. Furthermore, the expression levels of SIRT1/PGC­1α signaling pathway­related mRNA and proteins under MNAM treatment were detected by RT­qPCR and western blotting. MNAM reduced body weight gain in T2DM mice, decreased fasting blood glucose and fasting insulin levels, and inhibited IR. MNAM also regulated insulin signal transduction and promoted glucose utilization in skeletal muscle, and reduced lipid deposition. Thus, MNAM improved IR in the skeletal muscle of T2DM mice. Following application of a SIRT1 inhibitor, the effects of MNAM on the increased glucose utilization in insulin­resistant myocytes and the insulin signaling pathway were suppressed. The mechanism of action was associated with activation of the SIRT1/PGC­1α signaling pathway, which promoted the activation of the insulin receptor substrate IRS1/PI3K/AKT pathway.


Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Resistência à Insulina , Músculo Esquelético/efeitos dos fármacos , Niacinamida/análogos & derivados , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Sirtuína 1/metabolismo , Animais , Linhagem Celular , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Mioblastos/citologia , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , Niacinamida/farmacologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Sirtuína 1/genética
14.
Chem Biol Interact ; 338: 109427, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33639173

RESUMO

Oxidative stress and inflammation are implicated in the occurrence and progression of diabetic nephropathy (DN). Diphenyl diselenide (DPDS) is a stable and simple diaryl diselenide with anti-hyperglycemic, anti-inflammatory, and antioxidant activities. However, the effects of DPDS on DN are still unclear to date. Herein, we aimed to explore whether DPDS could improve renal dysfunction in streptozotocin (STZ)-induced diabetic rats and its underlying mechanisms. STZ-induced DN rats were administered with DPDS (5 or 15 mg/kg) or metformin (200 mg/kg) once daily by intragastric gavage for 12 weeks. DPDS supplementation significantly improved hyperglycemia, glucose intolerance, dyslipidemia, and the renal pathological abnormalities, concurrent with significantly reduced serum levels of creatinine, urea nitrogen, urine volume, and urinary levels of micro-albumin, ß2-microglobulin and N-acetyl-glucosaminidase activities. Moreover, DPDS effectively promoted the activities of antioxidant enzymes, and reduced the levels of MDA and pro-inflammatory factors in serum and the kidney. Furthermore, DPDS supplementation activated the renal Nrf2/Keap1 signaling pathway, but attenuated the high phosphorylation levels of NFκB, JNK, p38 and ERK1/2. Altogether, the current study indicated for the first time that DPDS ameliorated STZ-induced renal dysfunction in rats, and its mechanism of action may be attributable to suppressing oxidative stress via activating the renal Nrf2/Keap1 signaling pathway and mitigating inflammation by suppressing the renal NFκB/MAPK signaling pathways, suggesting a potential therapeutic approach for DN.


Assuntos
Derivados de Benzeno/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/patologia , Nefropatias Diabéticas/tratamento farmacológico , Inflamação/tratamento farmacológico , Compostos Organosselênicos/uso terapêutico , Estresse Oxidativo , Animais , Antioxidantes/metabolismo , Derivados de Benzeno/farmacologia , Citocinas/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/fisiopatologia , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/patologia , Nefropatias Diabéticas/fisiopatologia , Dislipidemias/complicações , Dislipidemias/tratamento farmacológico , Dislipidemias/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Inflamação/complicações , Inflamação/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Rim/patologia , Rim/fisiopatologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Modelos Biológicos , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Compostos Organosselênicos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Estreptozocina
15.
Am J Physiol Heart Circ Physiol ; 320(4): H1738-H1748, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33635166

RESUMO

Emerging evidence suggests the exercise pressor reflex is exaggerated in early stage type 1 diabetes mellitus (T1DM). Piezo channels may play a role in this exaggeration, as blocking these channels attenuates the exaggerated pressor response to tendon stretch in T1DM rats. However, tendon stretch constitutes a different mechanical and physiological stimuli than that occurring during muscle contraction. Therefore, the purpose of this study was to determine the contribution of Piezo channels in evoking the pressor reflex during an intermittent muscle contraction in T1DM. In unanesthetized decerebrate rats, we compared the pressor and cardioaccelerator responses to intermittent muscle contraction before and after locally injecting grammostola spatulata mechanotoxin 4 (GsMTx-4, 0.25 µM) into the hindlimb vasculature. Although GsMTx-4 has a high potency for Piezo channels, it has also been suggested to block transient receptor potential cation (TRPC) channels. We, therefore, performed additional experiments to control for this possibility by also injecting SKF 96365 (10 µM), a TRPC channel blocker. We found that local injection of GsMTx-4, but not SKF 96365, attenuated the exaggerated peak pressor (ΔMAP before: 33 ± 3 mmHg, after: 22 ± 3 mmHg, P = 0.007) and pressor index (ΔBPi before: 668 ± 91 mmHg·s, after: 418 ± 81 mmHg·s, P = 0.021) response in streptozotocin (STZ) rats (n = 8). GsMTx-4 attenuated the exaggerated early onset pressor and the pressor response over time, which eliminated peak differences as well as those over time between T1DM and healthy controls. These data suggest that Piezo channels are an effective target to normalize the exercise pressor reflex in T1DM.NEW & NOTEWORTHY This is the first study to demonstrate that blocking Piezo channels is effective in ameliorating the exaggerated exercise pressor reflex evoked by intermittent muscle contraction, commonly occurring during physical activity, in T1DM. Thus, these findings suggest Piezo channels may serve as an effective therapeutic target to reduce the acute and prolonged cardiovascular strain that may occur during dynamic exercise in T1DM.


Assuntos
Sistema Nervoso Autônomo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Sistema Cardiovascular/inervação , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Moduladores de Transporte de Membrana/farmacologia , Contração Muscular , Músculo Esquelético/inervação , Reflexo Anormal/efeitos dos fármacos , Venenos de Aranha/farmacologia , Animais , Sistema Nervoso Autônomo/metabolismo , Sistema Nervoso Autônomo/fisiopatologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/fisiopatologia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/metabolismo , Masculino , Condicionamento Físico Animal , Ratos Sprague-Dawley , Fatores de Tempo
16.
Life Sci ; 272: 119250, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33631174

RESUMO

AIM: Despite CXC chemokine ligand 16 (CXCL16) contributes to the pathogenesis of many inflammatory disorders, the mechanism by which CXCL16 is involved in T1DM remains unclear. In this study, we examined the role of the CXCL16/NF-κΒ p65 signaling pathway in the progression of this disease and the possible protective effect of resveratrol (RES) on streptozotocin (STZ)-induced T1DM. MAIN METHODS: Mice were classified into four groups of 10 animals each. The control group received citrate buffer. The RES group received 50 mg/kg i.p. RES for 12 days beginning on day 4 of citrate buffer. The STZ group received 55 mg/kg i.p. STZ once a day for 5 consecutive days. The fourth group injected with RES (50 mg/kg) for 12 days starting on day 4 of STZ injection. Biochemical, physical and oxidative stress parameters were measured in all groups. Moreover, expression of CXCL16 and CD45 was measured in pancreatic islets and spleen. Additionally, NF-κΒ p65 was investigated in isolated islets. KEY FINDINGS: Our results showed a significant elevation of CXCL16, NF-κΒ p65 and CD45 in islets of diabetic (DM) mice. Intriguingly, RES significantly restored distorted biochemical, physical and oxidative stress parameters after STZ treatment as well as inhibited the expression of CXCL16/NF-κΒ p65 in pancreatic islets. Moreover, RES normalized CXCL16 and CD45 expression in islets and spleen. SIGNIFICANCE: This study demonstrates first evidence that CXCL16/NF-κΒ p65 signaling pathway is associated with macrophage infiltration to pancreatic islet in T1DM and that RES successfully improved T1DM may be at least via inhibiting this pathway.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Ilhotas Pancreáticas/metabolismo , Resveratrol/farmacologia , Animais , Quimiocina CXCL16/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/fisiopatologia , Modelos Animais de Doenças , Ilhotas Pancreáticas/efeitos dos fármacos , Macrófagos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estresse Oxidativo , Resveratrol/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estreptozocina/farmacologia , Fator de Transcrição RelA/metabolismo
17.
Biomed Pharmacother ; 137: 111297, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33493968

RESUMO

Patients with diabetes commonly experience hyposalivation, which induces discomfort in eating, swallowing, dryness, smell, and speaking, as well as increases the incidence of periodontal disease. Dipeptidyl peptidase-4 (DPP4) inhibitors are frequently used as antidiabetic drugs that lower glucose levels by utilizing similar mechanisms; however, additional protective functions of each gliptin have been discovered. In this study, the protective roles of gemigliptin, a DPP4 inhibitor, against salivary dysfunction under diabetic conditions were investigated. Streptozotocin-induced diabetic rats received gemigliptin 10 mg/kg or 100 mg/kg via oral gavage for 3 weeks. The weights of salivary gland tissues, saliva secretion, and antioxidant capacity in salivary glands were reduced after diabetes induction, but were significantly preserved following gemigliptin treatment. In salivary gland analysis, expression of apoptotic proteins, as well as amylase and aquaporin-5 (AQP5) protein expression, were increased following gemigliptin treatment. Furthermore, the number of TUNEL-positive cells decreased after gemigliptin treatment. Therefore, gemigliptin has protective roles against salivary dysfunction observed in diabetes, mediated via antioxidant, anti-apoptotic, and salivary secretion mechanisms. These results may help in selecting a suitable drug for patients with diabetes experiencing salivary dysfunction.


Assuntos
Antioxidantes/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/farmacologia , Piperidonas/farmacologia , Pirimidinas/farmacologia , Doenças das Glândulas Salivares/prevenção & controle , Glândulas Salivares/efeitos dos fármacos , Salivação/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/fisiopatologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Doenças das Glândulas Salivares/etiologia , Doenças das Glândulas Salivares/fisiopatologia , Glândulas Salivares/metabolismo , Glândulas Salivares/fisiopatologia , Estreptozocina
18.
Life Sci ; 268: 119003, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33417957

RESUMO

AIMS: This study attempts to elicit whether the level of hyperglycemia in an early stage of diabetic nephropathy changes the renal expression of claudins-2 and -5 and to determine the involvement of glucose-induced oxidative stress. MAIN METHODS: Streptozotocin-induced type-1 and type-2 diabetic (DM1, DM2)-rat models were used. At 14-week old, the rats were placed in metabolic cages to evaluate proteinuria, creatinine clearance, and electrolyte excretion. Proximal tubules and glomeruli were isolated and analyzed by Western blot and immunofluorescence. Renal oxidative stress and metalloproteinase activities were evaluated. KEY FINDINGS: We found that claudin-5 expression in glomeruli and claudin-2 expression in proximal tubules were significantly reduced in DM1 versus DM2 model, paralleling with higher proteinuria and loss of sodium and potassium reabsorption, increased malondialdehyde levels, but lower antioxidant capacity in both models. Enzymatic activity of MMP-2 and-9 was increased in both diabetic groups versus control being higher in DM1 than DM2, suggesting higher claudin's degradation. SIGNIFICANCE: The level of hyperglycemia determines the time-dependent progression to diabetic nephropathy; hyperglycemia-induced oxidative stress parallels an increase in metalloproteinases (MMPs) activities consequently affecting the integrity of claudin-2 and -5 in glomerulus and proximal tubule. Our results suggest that chronic high-glycemia levels in early stages of diabetic nephropathy decrease expression of claudins-2 and -5, increase oxidative stress, and induce MMP-activity faster than chronic middle-glycemia levels.


Assuntos
Claudina-2/metabolismo , Claudina-5/metabolismo , Nefropatias Diabéticas/metabolismo , Hiperglicemia/metabolismo , Rim/metabolismo , Animais , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Nefropatias Diabéticas/patologia , Rim/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Estresse Oxidativo , Ratos Wistar , Transportador 2 de Glucose-Sódio/metabolismo , Estreptozocina
19.
Life Sci ; 268: 118989, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33417962

RESUMO

AIMS: The imbalance of M1/M2 macrophage ratio promotes the occurrence of diabetic cardiomyopathy (DCM), but the precise mechanisms are not fully understood. The aim of this study was to investigate whether miR-471-3p/silent information regulator 1 (SIRT1) pathway is involved in the macrophage polarization during the development of DCM. METHODS: Immunohistochemical staining was used to detect M1 and M2 macrophages infiltration in the heart tissue. Flow cytometry was used to detect the proportion of M1 and M2 macrophages. Expression of miR-471-3p was quantified by real time quantitative-PCR. Transfection of miRNA inhibitor into RAW264.7 cells was performed to investigate the underlying mechanisms. Bioinformatics methods and western blotting were used to explore the target gene of miR-471-3p and further confirmed by dual luciferase reporter assay. KEY FINDINGS: We observed that M1 macrophages infiltration in the heart of tissue in DCM while M2 type was decreased. M1/M2 ratio was increased significantly in bone marrow-derived macrophages (BMDMs) from db/db mice and in RAW264.7 cells treated with advanced glycation end products (AGEs). Meanwhile, miR-471-3p was significantly upregulated in RAW264.7 cells induced by AGEs and inhibition of miR-471-3p could reduce the inflammatory polarization of macrophages. Bioinformatics analysis identified SIRT1 as a target of miR-471-3p. Both dual luciferase reporter assay and western blotting verified that miR-471-3p negatively regulated SIRT1 expression. SIRT1 agonist resveratrol could downregulate the increased proportion of M1 macrophages induced by AGEs. CONCLUSION: Our results indicated that the development of DCM was related to AGEs-induced macrophage polarized to M1 type through a mechanism involving the miR-471-3p/SIRT1 pathway.


Assuntos
Cardiomiopatias Diabéticas/genética , Cardiomiopatias Diabéticas/patologia , Macrófagos/patologia , MicroRNAs/genética , Animais , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Fibrose , Regulação da Expressão Gênica , Produtos Finais de Glicação Avançada/toxicidade , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/patologia , Células RAW 264.7 , Sirtuína 1/genética , Sirtuína 1/metabolismo
20.
Am J Physiol Heart Circ Physiol ; 320(3): H1089-H1101, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33449847

RESUMO

The pathological involvement of anion channels in vascular dysfunction that occurs during type 2 diabetes (T2D) is unclear. Here, we tested the hypothesis that TMEM16A, a calcium-activated chloride (Cl-) channel, contributes to modifications in arterial contractility during T2D. Our data indicate that T2D increased TMEM16A mRNA in arterial smooth muscle cells and total and surface TMEM16A protein in resistance-size cerebral and hindlimb arteries of mice. To examine vascular cell types in which TMEM16A protein increased and the functional consequences of TMEM16A upregulation during T2D, we generated tamoxifen-inducible, smooth muscle cell-specific TMEM16A knockout (TMEM16A smKO) mice. T2D increased both TMEM16A protein and Cl- current density in arterial smooth muscle cells of control (TMEM16Afl/fl) mice. In contrast, T2D did not alter arterial TMEM16A protein or Cl- current density in smooth muscle cells of TMEM16A smKO mice. Intravascular pressure stimulated greater vasoconstriction (myogenic tone) in the arteries of T2D TMEM16Afl/fl mice than in the arteries of nondiabetic TMEM16Afl/fl mice. This elevation in myogenic tone in response to T2D was abolished in the arteries of T2D TMEM16A smKO mice. T2D also reduced Akt2 protein and activity in the arteries of T2D mice. siRNA-mediated knockdown of Akt2, but not Akt1, increased arterial TMEM16A protein in nondiabetic mice. In summary, data indicate that T2D is associated with an increase in TMEM16A expression and currents in arterial smooth muscle cells that produces vasoconstriction. Data also suggest that a reduction in Akt2 function drives these pathological alterations during T2D.NEW & NOTEWORTHY We investigated the involvement of TMEM16A channels in vascular dysfunction during type 2 diabetes (T2D). TMEM16A message, protein, and currents were higher in smooth muscle cells of resistance-size arteries during T2D. Pressure stimulated greater vasoconstriction in the arteries of T2D mice that was abolished in the arteries of TMEM16A smKO mice. Akt2 protein and activity were both lower in T2D arteries, and Akt2 knockdown elevated TMEM16A protein. We propose that a decrease in Akt2 function stimulates TMEM16A expression in arterial smooth muscle cells, leading to vasoconstriction during T2D.


Assuntos
Anoctamina-1/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Angiopatias Diabéticas/metabolismo , Membro Posterior/irrigação sanguínea , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Vasoconstrição , Animais , Anoctamina-1/deficiência , Anoctamina-1/genética , Artérias/metabolismo , Artérias/fisiopatologia , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/induzido quimicamente , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/genética , Angiopatias Diabéticas/fisiopatologia , Células HEK293 , Humanos , Resistência à Insulina , Masculino , Potenciais da Membrana , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/fisiopatologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Estreptozocina , Regulação para Cima
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