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1.
Front Pharmacol ; 10: 1318, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31787898

RESUMO

The objective of this study was to investigate whether MTNR1B gene variants influence repaglinide response in Chinese patients with newly diagnosed type 2 diabetes mellitus (T2DM). A total of 300 patients with T2DM and 200 control subjects were enrolled to identify MTNR1B rs10830963 and rs1387153 genotypes by real-time polymerase chain reaction (PCR), with subsequent high-resolution melting (HRM) analysis. Ninety-five patients with newly diagnosed T2DM were randomly selected to undergo 8 weeks of repaglinide treatment (3 mg/day). After 8-week repaglinide monotherapy, patients with at least one G allele of MTNR1B rs10830963 showed a smaller decrease in fasting plasma glucose (FPG) (P = 0.031) and a smaller increase in homeostasis model assessment for beta cell function (HOMA-B) (P = 0.002) levels than those with the CC genotype did. The T allele carriers at rs1387153 exhibited a smaller decrease in FPG (P = 0.007) and smaller increases in postprandial serum insulin (PINS) (P = 0.016) and HOMA-B (P < 0.001) levels compared to individuals with the CC genotype. These data suggest that the MTNR1B rs10830963 and rs1387153 polymorphisms are associated with repaglinide monotherapy efficacy in Chinese patients with T2DM.

2.
Acta Pharmacol Sin ; 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645661

RESUMO

Extracellular matrix (ECM) deposition following reactive oxygen species (ROS) overproduction has a key role in diabetic nephropathy (DN), thus, antioxidant therapy is considered as a promising strategy for treating DN. Here, we investigated the therapeutic effects of AB38b, a novel synthetic α, ß-unsaturated ketone compound, on the oxidative stress (OS) and ECM accumulation in type 2 diabetes mice, and tried to clarify the mechanisms underlying the effects in high glucose (HG, 30 mM)-treated mouse glomerular mesangial cells (GMCs). Type 2 diabetes model was established in mice with high-fat diet feeding combined with streptozocin intraperitoneal administration. The diabetic mice were then treated with AB38b (10, 20, 40 mg· kg-1· d-1, ig) or a positive control drug resveratrol (40 mg· kg-1· d-1, ig) for 8 weeks. We showed that administration of AB38b or resveratrol prevented the increases in malondialdehyde level, lactate dehydrogenase release, and laminin and type IV collagen deposition in the diabetic kidney. Simultaneously, AB38b or resveratrol markedly lowered the level of Keap1, accompanied by evident activation of Nrf2 signaling in the diabetic kidney. The underlying mechanisms of antioxidant effect of AB38b were explored in HG-treated mouse GMCs. AB38b (2.5-10 µM) or resveratrol (10 µM) significantly alleviated OS and ECM accumulation in HG-treated GMCs. Furthermore, AB38b or resveratrol treatment effectively activated Nrf2 signaling by inhibiting Keap1 expression without affecting the interaction between Keap1 and Nrf2. Besides, AB38b treatment effectively suppressed the ubiquitination of Nrf2. Taken together, this study demonstrates that AB38b ameliorates experimental DN through antioxidation and modulation of Keap1/Nrf2 signaling pathway.

3.
Front Oncol ; 9: 595, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31338328

RESUMO

Despite responses to initial treatment of photodynamic therapy (PDT) being promising, a recurrence rate exists. Thus, finding novel therapeutic targets to enhance PDT efficacy is an urgent need. Reports indicate that connexin (Cx) 40 plays an important role in tumor angiogenesis and growth. However, it is unknown whether Cx40-composed channels have effects on PDT efficacy. The study uniquely demonstrated that Cx40-formed channels could enhance the phototoxicity of PDT to malignant cells in vitro and in vivo. Specifically, Cx40-formed channels at high cell density could increase PDT photocytotoxicity. This action was substantially restricted when Cx40 expression was not induced or Cx40 channels were restrained. Additionally, the presence of Cx40-composed channels enhanced the phototoxicity of PDT in the tumor xenografts. The above results indicate that enhancing the function of Cx40-formed channels increases PDT efficacy. The enhancement of PDT efficacy mediated by Cx40 channels was related with intracellular pathways mediated by ROS and calcium pathways, but not the lipid peroxide-mediated pathway. This work demonstrates the capacity of Cx40-mediated channels to increase PDT efficacy and suggests that therapeutic strategies designed to maintain or enhance Cx40 expression and/or channels composed by Cx40 may increase the therapeutic efficacy of PDT.

4.
Acta Pharmacol Sin ; 40(12): 1555-1567, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31235817

RESUMO

Epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells is one of the potential mechanisms of renal fibrosis, which promotes the development of diabetic nephropathy (DN). However, the molecular mechanisms of EMT remain largely unknown. Tuberous sclerosis proteins TSC1 and TSC2 are key integrators of growth factor signaling, and the loss of TSC1 or TSC2 function leads to a spectrum of diseases that underlie abnormalities in cell growth, proliferation, differentiation, and migration. In this study, we investigated the effects of TSC1 on high glucose (HG)-induced EMT of human proximal tubular epithelial HK-2 cells in vitro and renal fibrosis in TSC1-/- and db/db mice. We found that the exposure of HK-2 cells to HG (30 mM) time-dependently decreased TSC1 expression, increased the phosphorylation of mTORC1, P70S6K, and 4E-BP-1, and promoted cell migration, resulting in EMT. Transfection of the cells with TSC1 mimic significantly ameliorated HG-induced EMT of HK-2 cells. The tubules-specific TSC1 knockout mice (TSC1-/-) displayed a significant decline in renal function. TSC1-/- mice, similar to db/db mice, showed greatly activated mTORC1 signaling and EMT process in the renal cortex and exacerbated renal fibrosis. Overexpression of TSC1 through LV-TSC1 transfection significantly alleviated the progression of EMT and renal fibrosis in the renal cortex of db/db mice. Taken together, our results suggest that TSC1 plays a key role in mediating HG-induced EMT, and inhibition of TSC1-regulated mTORC1 signaling may be a potential approach to prevent renal fibrosis in DN.

5.
Exp Ther Med ; 17(1): 835-846, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30651870

RESUMO

Oxidative stress has been reported to serve an important role in the development and progression of diabetic nephropathy (DN). Epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells promotes renal fibrosis in DN, while the mechanism of reactive oxygen species (ROS)-mediated EMT is not fully understood. The aim of the present study was to investigate the effect of high glucose-induced ROS on the activation of the transforming growth factor (TGF)-ß1/phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway in a normal rat kidney tubular epithelial cell line (NRK-52E) and rats with type 1 diabetes. In vitro, high glucose-stimulated ROS production resulted in increased TGF-ß1 expression as well as an increase in the Akt and mTOR phosphorylation ratio, resulting in EMT. When cells were pre-treated with ROS inhibitors, changes in TGF-ß1, Akt and mTOR were significantly ameliorated. In vivo, diabetic rats experienced a significant decline in renal function and severe renal fibrosis compared with control rats at 8 weeks following streptozocin injection. Levels of malondialdehyde and TGF-ß1/PI3K/Akt/mTOR pathway activation were increased in the renal cortex of rats with diabetes compared with the control rats. Furthermore, renal fibrosis was further aggravated in DN compared with the control rats. The results of the present study suggest that ROS serves an important role in mediating high glucose-induced EMT and inhibits activation of the TGF-ß1/PI3K/Akt/mTOR pathway. ROS may therefore have potential as a treatment approach to prevent renal fibrosis in DN.

6.
Naunyn Schmiedebergs Arch Pharmacol ; 391(11): 1237-1245, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30062553

RESUMO

Glyoxalase 1 (Glo-1) is an ubiquitous cellular enzyme that participates in the detoxification of methylglyoxal (MG), a cytotoxic byproduct of glycolysis that induces protein modification (advanced glycation end products [AGEs]), oxidative stress, and inflammation. The concentration of MG is elevated under high-glucose conditions, such as diabetes. Therefore, Glo-1 and MG have been implicated in the pathogenesis of diabetic encephalopathy. We investigated the effect of quercetin on brain damage that was caused by diabetes in rats and the mechanisms associated with Glo-1. Streptozotocin-induced diabetic rats were treated orally with quercetin (30, 60, and 90 mg/kg) or distilled water for 14 weeks. The temporal cortex and hippocampus were harvested and analyzed for different indices assays. Quercetin, especially at a high dose, increased the levels of reduced glutathione and the activity of superoxide dismutase and decreased the levels of AGEs, the receptor for AGEs (RAGE), and malondialdehyde in the diabetic brain. Quercetin also significantly decreased the levels of inflammatory markers (cyclooxygenase-2, interleukin-1ß, and tumor necrosis factor α) in diabetic brains. Most importantly, Glo-1 activity and protein expression were increased in quercetin-treated diabetic rat brains compared with untreated diabetic brains. These results indicate that quercetin exerts beneficial effects by decreasing protein glycation, oxidative stress, and inflammation through the upregulation of Glo-1, which may ameliorate diabetic encephalopathy.


Assuntos
Anti-Inflamatórios/farmacologia , Disfunção Cognitiva/metabolismo , Diabetes Mellitus Experimental/metabolismo , Hipocampo/efeitos dos fármacos , Lactoilglutationa Liase/metabolismo , Fármacos Neuroprotetores/farmacologia , Quercetina/farmacologia , Lobo Temporal/efeitos dos fármacos , Animais , Anti-Inflamatórios/uso terapêutico , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Ciclo-Oxigenase 2/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Hipocampo/metabolismo , Masculino , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Quercetina/uso terapêutico , Ratos Sprague-Dawley , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Lobo Temporal/metabolismo
7.
Naunyn Schmiedebergs Arch Pharmacol ; 391(2): 159-168, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29275517

RESUMO

The aim of this study is to investigate effects and potential mechanisms of sarsasapogenin (Sar), an active component purified from Rhizoma Anemarrhenae, on high glucose-induced amyloid-beta (Aß) peptide overproduction in HT-22 cells. HT-22 cells were divided into normal glucose; high glucose (HG); HG co-treated with low, middle, and high concentration of Sar (1, 5, 25 µmol/L); and peroxisome proliferator-activated receptor γ (PPARγ) agonist (10 µmol/L pioglitazone). After treatment for 24 h, protein expression of Aß and ß-site Aß precursor protein cleaving enzyme 1 (BACE1) and activated PPARγ level were determined by Western blot; Aß42 levels were also measured by using both immunofluorescence and ELISA methods. BACE1 activity and mRNA level were assessed by fluorospectrophotometry and quantitative PCR, respectively. Cell viability was assayed with a CCK-8 kit. Elevated Aß expression and Aß42 level were found in HG-treated HT-22 cells, accompanied by increased BACE1 protein and mRNA levels as well as enzymatic activity, which was markedly attenuated by three concentrations of Sar and pioglitazone. Moreover, HG reduced nuclear PPARγ levels, which was reversed by middle and high concentrations of Sar as well as pioglitazone. PPARγ antagonist GW9662 (20 µmol/L) pretreatment reversed the effect of Sar on BACE1 protein expression in HG-cultured HT-22 cells. Additionally, Sar suppressed HG-induced decreases in cell viability of HT-22 cells. High glucose can induce an increase in Aß levels and a decrease in cell viability in HT-22 cells, while co-treatment with Sar improves these results, which is mediated likely through activation of PPARγ and subsequent downregulation of BACE1.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/biossíntese , Medicamentos de Ervas Chinesas/farmacologia , Glucose/toxicidade , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/biossíntese , Espirostanos/farmacologia , Animais , Linhagem Celular Transformada , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Camundongos
8.
Biomed Pharmacother ; 96: 328-335, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29024899

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease globally. The progression of NAFLD is complex and associated with inflammation, oxidative stress, autophagy, endoplasmic reticulum stress, and insulin resistance. Mangiferin, a natural C-glucosyl xanthone, has been reported to show multiple biological activities. The aim of this study was to investigate the therapeutic effect of mangiferin on NAFLD and the underlying molecular mechanism. We established a mouse model of NAFLD using a high-fat diet (HFD), and injected the mice with different doses of mangiferin (15, 30, and 60mg/kg, intraperitoneal) for 12 weeks. Liver tissue was assessed to evaluate changes in inflammatory responses, autophagy, and glycolipid metabolism. We found that mangiferin decreased body weight, as well as the levels of triglycerides and total cholesterol in plasma and the liver. It also increased glucose tolerance in HFD-fed mice. In addition, mangiferin decreased inflammatory responses by inhibiting the activities of nuclear factor kappa B and c-Jun N-terminal kinase, regulated autophagy via the AMP-activated protein kinase/mechanistic target of rapamycin signaling pathway, and improved glycolipid metabolism via modulation of the insulin receptor substrate/phosphoinositide 3-kinase/protein kinase B signaling pathway. This study demonstrated that mangiferin significantly ameliorates NAFLD development in HFD-fed mice by inhibiting inflammatory responses, activating autophagy, and improving glycolipid metabolism.


Assuntos
Autofagia/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Xantonas/uso terapêutico , Animais , Autofagia/fisiologia , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Distribuição Aleatória , Xantonas/farmacologia
9.
Int J Nanomedicine ; 12: 6383-6398, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28919742

RESUMO

Biodegradable nanomaterials have been widely used in numerous medical fields. To further improve such efforts, this study focused on the intracellular disposition of chitosan nanoparticles (CsNPs) in macrophages, a primary cell of the mononuclear phagocyte system (MPS). Such interactions with the MPS determine the nanoparticle retention time in the body and consequently play a significant role in their own clinical safety. In this study, various dye-labeled CsNPs (about 250 nm) were prepared, and a murine macrophage cell line (RAW 264.7) was selected as a model macrophage. The results showed two mechanisms of macrophage incorporation of CsNPs, ie, a clathrin-mediated endocytosis pathway (the primary) and phagocytosis. Following internalization, the particles partly dissociated in the cells, indicating cellular digestion of the nanoparticles. It was proved that, after intracellular uptake, a large proportion of CsNPs were exocytosed within 24 h; this excretion induced a decrease in fluorescence intensity in cells by 69%, with the remaining particles possessing difficulty being cleared. Exocytosis could be inhibited by both wortmannin and vacuolin-1, indicating that CsNP uptake was mediated by lysosomal and multivesicular body pathways, and after exocytosis, the reuptake of CsNPs by neighboring cells was verified by further experiments. This study, thus, elucidated the fate of CsNPs in macrophages as well as identified cellular disposition mechanisms, providing the basis for how CsNPs are recognized by the MPS; such information is crucial to numerous medical applications of CsNPs.


Assuntos
Quitosana/farmacocinética , Exocitose/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Nanopartículas/química , Androstadienos/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Linhagem Celular , Quitosana/química , Quitosana/farmacologia , Endocitose/efeitos dos fármacos , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacocinética , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Macrófagos/metabolismo , Camundongos , Sistema Fagocitário Mononuclear/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Wortmanina
10.
J Biophotonics ; 10(12): 1586-1596, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28417552

RESUMO

In spite of the promising initial treatment responses presented by photodynamic therapy (PDT), 5-year recurrence rates remain high level. Therefore, improvement in the efficacy of PDT is needed. There are reports showing that connexin(Cx) 26-composed gap junctional intercellular communication (GJIC) enhances the intercellular propagation of "death signal", thereby increasing chemotherapeutic cytotoxicity. However, it is unclear whether Cx26-formed GJIC has an effect on PDT phototoxicity. The results in the present study showed that Cx26-composed GJ formation at high density enhances the phototoxicity of Photofrin-PDT. When the Cx26 is not expressed or Cx26 channels are blocked, the phototoxicity in high-density cultures substantially reduces, indicating that the enhanced PDT phototoxicity at high density is mediated by Cx26-composed GJIC. The GJIC-mediated increase in PDT phototoxicity was associated with ROS, calcium and lipid peroxide-mediated stress signaling pathways. The work presents the ability of Cx26-composed GJIC to enhance the sensitivity of malignant cells to PDT, and indicates that maintenance or increase of Cx26-formed GJIC may be a profitable strategy towards the enhancement of PDT therapeutic efficiency. Picture: The survival response of Photofrin-PDT in Dox-treated (Cx26 expressing, GJ-formed) and Dox-untreated cells (Cx26 non-expressing, GJ-unformed) at high-cell density condition.


Assuntos
Cálcio/metabolismo , Comunicação Celular/efeitos dos fármacos , Comunicação Celular/efeitos da radiação , Conexinas/metabolismo , Junções Comunicantes/metabolismo , Peróxidos Lipídicos/metabolismo , Fotoquimioterapia , Aldeídos/metabolismo , Ceramidas/biossíntese , Éter de Diematoporfirina/farmacologia , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Espaço Extracelular/efeitos da radiação , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/efeitos da radiação , Células HeLa , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Espaço Intracelular/efeitos da radiação
11.
Iran J Basic Med Sci ; 20(11): 1220-1226, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29299199

RESUMO

Objectives: Increasing evidence suggests that regular physical exercise improves type 2 diabetes mellitus (T2DM). However, the potential beneficial effects of swimming on insulin resistance and lipid disorder in T2DM, and its underlying mechanisms remain unclear. Materials and Methods: Rats were fed with high fat diet and given a low dosage of Streptozotocin (STZ) to induce T2DM model, and subsequently treated with or without swimming exercise. An 8-week swimming program (30, 60 or 120 min per day, 5 days per week) decreased body weight, fasting blood glucose and fasting insulin. Results: Swimming ameliorated lipid disorder, improved muscular atrophy and revealed a reduced glycogen deposit in skeletal muscles of diabetic rats. Furthermore, swimming also inhibited the activation of Wnt3a/ß-catenin signaling pathway, decreased Wnt3a mRNA and protein level, upregulated GSK3ß phosphorylation activity and reduced the expression of ß-catenin phosphorylation in diabetic rats. Conclusion: The trend of the result suggests that swimming exercise proved to be a potent ameliorator of insulin resistancein T2DM through the modulation of Wnt3a/ß-catenin pathway and therefore, could present a promising therapeutic measure towards the treatment of diabetes and its relatives.

12.
Pain ; 158(1): 130-139, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27749604

RESUMO

Accumulating evidence has demonstrated that epigenetic modification-mediated changes in pain-related gene expressions play an important role in the development and maintenance of neuropathic pain. Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase, is involved in the development of chronic pain. Moreover, SIRT1 may be a novel therapeutic target for the prevention of type 2 diabetes mellitus (T2DM). But the role of SIRT1 in T2DM-induced neuropathic pain remains unknown. In this study, we found that spinal SIRT1 expression and activity were downregulated significantly in high-fat-fed/low-dose streptozotocin-induced neuropathic pain rats. SIRT1 localized in spinal neurons but not in astrocytes or microglia. Furthermore, the expressions of metabotropic glutamate receptor (mGluR1) and mGluR5, which play a key role in central sensitization and neuropathic pain, and H3 acetylation levels at Grm1/5 (encoding mGluR1/5) promoter regions were increased in diabetic neuropathic pain rats. SIRT1 activator SRT1720 reversed thermal hyperalgesia and mechanical allodynia and spinal neuronal activation in diabetic neuropathic pain rats. Concurrently, increased expressions of mGluR1/5 and H3 acetylation levels at Grm1/5 promoter regions were reversed by SIRT1 activation. In addition, knockdown of SIRT1 by Ad-SIRT1-shRNA induced pain behaviors and spinal neuronal activation in normal rats, which was accompanied by the increased expressions of mGluR1/5 and H3 acetylation levels at Grm1/5 promoter regions. Therefore, we concluded that SIRT1-mediated epigenetic regulation of mGluR1/5 expressions was involved in the development of neuropathic pain in type 2 diabetic rats.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Regulação da Expressão Gênica/genética , Neuralgia/etiologia , Neuralgia/patologia , Receptor de Glutamato Metabotrópico 5/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Sirtuína 1/metabolismo , Animais , Astrócitos/metabolismo , Diabetes Mellitus Tipo 2/etiologia , Dieta Hiperlipídica/efeitos adversos , Regulação da Expressão Gênica/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Hiperalgesia/diagnóstico , Hiperalgesia/etiologia , Hiperglicemia/etiologia , Hiperglicemia/fisiopatologia , Masculino , Neuralgia/tratamento farmacológico , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor de Glutamato Metabotrópico 5/genética , Receptores de Glutamato Metabotrópico/genética , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/genética , Medula Espinal/metabolismo , Medula Espinal/patologia , Estreptozocina/toxicidade
13.
Mol Neurobiol ; 54(6): 4060-4070, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27318675

RESUMO

Mangiferin, a natural C-glucoside xanthone, has anti-inflammatory, anti-oxidative, neuroprotective actions. Our previous study showed that mangiferin could attenuate diabetes-associated cognitive impairment of rats by enhancing the function of glyoxalase 1 (Glo-1) in brain. The aim of this study was to investigate whether Glo-1 upregulation by mangiferin in central neurons exposed to chronic high glucose may be related to activation of Nrf2/ARE pathway. Compared with normal glucose (25 mmol/L) culture, Glo-1 protein, mRNA, and activity levels were markedly decreased in primary hippocampal and cerebral cortical neurons cultured with high glucose (50 mmol/L) for 72 h, accompanied by the declined Nrf2 nuclear translocation and protein expression of Nrf2 in cell nucleus, as well as protein expression and mRNA level of γ-glutamylcysteine synthetase (γ-GCS) and superoxide dismutase activity, target genes of Nrf2/ARE signaling. Nonetheless, high glucose cotreating with mangiferin or sulforaphane, a typical inducer of Nrf2 activation, attenuated the above changes in both central neurons. In addition, mangiferin and sulforaphane significantly prevented the formation of advanced glycation end-products (AGEs) reflecting Glo-1 activity, while elevated the level of glutathione, a cofactor of Glo-1 activity and production of γ-GCS, in high glucose cultured central neurons. These findings demonstrated that Glo-1 was greatly downregulated in central neurons exposed to chronic high glucose, which is expected to lead the formation of AGEs and oxidative stress damages. We also proved that mangiferin enhanced the function of Glo-1 under high glucose condition by inducing activation of Nrf2/ARE signaling pathway.


Assuntos
Elementos de Resposta Antioxidante/genética , Glucose/toxicidade , Lactoilglutationa Liase/genética , Fator 2 Relacionado a NF-E2/metabolismo , Neurônios/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Xantonas/farmacologia , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Células Cultivadas , Glutamato-Cisteína Ligase/metabolismo , Glutationa/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Lactoilglutationa Liase/metabolismo , Neurônios/efeitos dos fármacos , Pressão Osmótica , Pressão , Transporte Proteico/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Solventes , Superóxido Dismutase/metabolismo
14.
Mol Med Rep ; 13(6): 5326-34, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27109015

RESUMO

Ibuprofen, a commonly administered nonsteroidal anti­inflammatory therapeutic agent, is also a partial agonist of peroxisome proliferator­activated receptor Î³ (PPARγ). The present study investigated the effects of ibuprofen on type 1 diabetic nephropathy (DN) in rats, and the potential mechanisms associated with the activation of PPARγ. Diabetic rats were induced through a single intraperitoneal injection of streptozotocin before oral treatment with ibuprofen or pioglitazone for 8 weeks. The 24­h urine collection was performed for measurement of total protein content. The kidney was fixed in 10% formalin for periodic acid­Schiff and Masson's trichrome staining. Blood and residual kidney tissue samples were collected to measure the associated biochemical parameters. Chronic ibuprofen treatment decreased urinary protein excretion, blood urea nitrogen, glomerular basement membrane thickening and renal fibrosis, which were accompanied by increases in PPARγ protein expression, glutathione (GSH) level, and superoxide dismutase (SOD) activity, decreases in cyclooxygenase 2 and inducible nitric oxide synthase protein expressions, as well as a decreased interleukin 1ß (IL­1ß) level in the renal cortex of DN rats. Furthermore, the reduced IL­1ß level, increased GSH quantities and stronger SOD activity in the rat serum were evaluated in ibuprofen­treated diabetic rats and were compared with untreated diabetic rats. Regarding GSH and IL­1ß levels, ibuprofen was identified to be superior to the positive control, pioglitazone, while levels of the other indices were identified to be similar. Thus, ibuprofen was observed to prevent the development of DN, caused by type 1 diabetes, by anti­inflammatory and anti­oxidative action, potentially via PPARγ activation.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Ibuprofeno/farmacologia , Rim/metabolismo , Animais , Ciclo-Oxigenase 2/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Glutationa/metabolismo , Interleucina-1beta/metabolismo , Rim/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo
15.
Mol Neurobiol ; 53(7): 4972-80, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26374551

RESUMO

Acetylcholinesterase (AChE) is impaired in brain of diabetic animals, which may be one of the reasons for diabetes-associated cognitive decline. However, the mechanism is still unknown. The present study was designed to investigate whether the increased expression of AChE in central neurons under high glucose (HG) condition was due to activation of mammalian target of rapamycin (mTOR) signaling. It was found that more production of reactive oxygen species, and higher levels of phospho-Akt, phospho-mTOR, phospho-p70S6K, and AChE were detected in HT-22 cells in HG group than normal glucose group after culture for 24 h, which were all attenuated by an antioxidant N-acetyl-L-cysteine. A PI3K inhibitor LY294002 significantly decreased the levels of phospho-Akt, phospho-mTOR, phospho-p70S6K, and AChE protein expression in HG-cultured HT-22 cells, and an mTOR inhibitor rapamycin markedly reduced the levels of phospho-mTOR, phospho-p70S6K, and AChE expression. Furthermore, compared with normal rats, diabetic rats showed remarkable increases in levels of AChE activity and expression, malondialdehyde, phospho-mTOR, phospho-p70S6K, and a significant decrease in total superoxide dismutase activity in both hippocampus and cerebral cortex. However, much lower levels of phospho-mTOR, phospho-p70S6K, and AChE expression occurred in both brain regions of diabetic rats treated with rapamycin when compared with untreated ones. These results indicated that mTOR signaling was activated through the activation of PI3K/Akt pathway mediated by oxidative stress in HG-cultured HT-22 cells and diabetic rat brains, which contributed to the elevated protein expression of AChE in central neurons under the condition of HG.


Assuntos
Acetilcolinesterase/biossíntese , Diabetes Mellitus Experimental/metabolismo , Regulação Enzimológica da Expressão Gênica , Glucose/toxicidade , Serina-Treonina Quinases TOR/metabolismo , Acetilcolinesterase/genética , Animais , Linhagem Celular Transformada , Células Cultivadas , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Cromonas/farmacologia , Diabetes Mellitus Experimental/genética , Glucose/administração & dosagem , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Camundongos , Morfolinas/farmacologia , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Sirolimo/farmacologia
16.
Mass Spectrom Rev ; 35(5): 574-600, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-25284160

RESUMO

Hydrophilic interaction chromatography (HILIC) is an emerging separation mode of liquid chromatography (LC). Using highly hydrophilic stationary phases capable of retaining polar/ionic metabolites, and accompany with high organic content mobile phase that offer readily compatibility with mass spectrometry (MS) has made HILIC an attractive complementary tool to the widely used reverse-phase (RP) chromatographic separations in metabolomic studies. The combination of HILIC and RPLC coupled with an MS detector expands the number of detected analytes and provides more comprehensive metabolite coverage than use of only RP chromatography. This review describes the recent applications of HILIC-MS/MS in metabolomic studies, ranging from amino acids, lipids, nucleotides, organic acids, pharmaceuticals, and metabolites of specific nature. The biological systems investigated include microbials, cultured cell line, plants, herbal medicine, urine, and serum as well as tissues from animals and humans. Owing to its unique capability to measure more-polar biomolecules, the HILIC separation technique would no doubt enhance the comprehensiveness of metabolite detection, and add significant value for metabolomic investigations. © 2014 Wiley Periodicals, Inc. Mass Spec Rev 35:574-600, 2016.


Assuntos
Cromatografia Líquida , Interações Hidrofóbicas e Hidrofílicas , Metabolômica , Animais , Cromatografia de Fase Reversa , Humanos , Espectrometria de Massas em Tandem
17.
Phytomedicine ; 22(12): 1071-8, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26547529

RESUMO

BACKGROUND: Recently, extract of Ginkgo biloba leaves (GbE) have become widely known phytomedicines and have shown various pharmacological activities, including improvement of blood circulation, protection of oxidative cell damage, prevention of Alzheimer's disease, treatment of cardiovascular disease and diabetes complications. This study was designed to investigate the effects of an ethanolic GbE on renal fibrosis in diabetic nephropathy (DN) and to clarify the possible mechanism by which GbE prevents renal fibrosis. STUDY DESIGN: We investigated the protective effects of GbE on renal fibrosis in STZ-induced diabetic rats. Rats were randomized into six groups termed normal control, diabetes mellitus, low dose of GbE (50 mg/kg/d), intermediate dose of GbE (100 mg/kg/d), high dose of GbE (200 mg/kg/d) and rapamycin (1 mg/kg/d). METHODS: After 12 weeks, the rats were sacrificed and then fasting blood glucose (FBG), creatinine (Cr), blood urea nitrogen (BUN), urine protein, relative kidney weight, glycogen and collagen accumulation, and collagen IV and laminin expression were measured by different methods. The amounts of E-cadherin, α-SMA and snail, as well as the phosphorylation of Akt, mTOR and p70S6K in the renal cortex of rats, were examined by western blotting. RESULTS: Compared with diabetic rats, the levels of Cr, BUN, urine protein, relative kidney weight, accumulation of glycogen and collagen, and expression of collagen IV and laminin in the renal cortex were all decreased in GbE treated rats. In addition, GbE reduced the expression of E-cadherin, α-SMA, snail and the phosphorylation of Akt, mTOR and p70S6K in diabetic renal cortex. CONCLUSION: GbE can prevent renal fibrosis in rats with diabetic nephropathy, which is most likely to be associated with its abilities to inhibit the Akt/mTOR signaling pathway.


Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Ginkgo biloba/química , Nefropatias/prevenção & controle , Extratos Vegetais/farmacologia , Transdução de Sinais , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Fibrose/prevenção & controle , Rim/efeitos dos fármacos , Rim/patologia , Masculino , Fitoterapia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Serina-Treonina Quinases TOR/metabolismo
18.
Pharmacol Res ; 99: 237-47, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26151815

RESUMO

Quercetin is a classic flavonoid that inhibits the epithelial-mesenchymal transition (EMT) of tumor cells. However, the effects of quercetin on the EMT of renal tubular epithelial cells, a potential mechanism of renal fibrosis and important characteristic of diabetic nephropathy (DN), remain largely unknown. In the present study, we investigated the effects of quercetin on the EMT of two lines of renal tubular proximal epithelial cells (HK-2 and NRK-52E) induced with high glucose and renal fibrosis resulting from type 1 diabetes and tried to clarify the specific mechanisms underlying these effects. The in vitro results showed that the EMT of HK-2 and NRK-52E cells was induced by high glucose, and mTORC1/p70S6K was highly activated in these two cell lines cultured under high glucose. Quercetin effectively ameliorated the high glucose-induced EMT of HK-2 and NRK-52E cells and inhibited the activation of mTORC1/p70S6K. In vivo, diabetic rats showed a significant decline in renal function and severe renal fibrosis at 14 weeks after STZ injection. Furthermore, mTORC1/p70S6K was activated in the renal cortex of diabetic rats. Treatment with quercetin alleviated the decline in renal function, and the progression of renal fibrosis and inhibited mTORC1/p70S6K activation in the diabetic renal cortex. In addition, we examined the protein and mRNA levels of four transcriptional factors (snail, slug, twist and ZEB-1), which regulate E-cadherin expression at the transcriptional level both in vivo and in vitro. The results revealed that the elevated expression of snail and twist in HK-2 and NRK-52E cells cultured under high glucose and in the renal cortex of diabetic rats was inhibited by quercetin. These results demonstrated that quercetin ameliorates the EMT of HK-2 and NRK-52E cells induced by high glucose and renal fibrosis induced by diabetes, and these effects have been associated with the inhibition of the two transcriptional factors (snail and twist) and the activation of mTORC1/p70S6K.


Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Túbulos Renais Proximais/efeitos dos fármacos , Complexos Multiproteicos/metabolismo , Quercetina/farmacologia , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Animais , Caderinas/metabolismo , Linhagem Celular , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Fibrose/tratamento farmacológico , Fibrose/metabolismo , Glucose/metabolismo , Humanos , Túbulos Renais Proximais/metabolismo , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-26113453

RESUMO

The mesangial cell (MC) cultured with high glucose has been used to observe the protective effect of Ginkgo biloba extract (GBE) against diabetic nephropathy (DN), but the compounds interacting with cell are still unknown, which may be potential bioactive components. Based on this, the determination of GBE in MC lysates was proposed by high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) in this study. The MC was cultured with normal or high glucose with GBE for 4, 8, 12, 16, 24 and 48h. The harvested cell was extracted with 40% acetic acid in water and further analyzed by LC-MS/MS. All the validation data including linearity, intra-day and inter-day precision, limit of detection and quantification, matrix effect, and stability were within the required limits. The validated method was successfully applied to quantify 11 compounds of GBE in cell lysates. The results showed that high glucose prolonged the peak time of all observed 11 compounds and peak concentrations of bilobalide, ginkgolide C, ginkgolide B, quercetin, luteolin, kaempferol, isorhamnetin and genkwanin in cell lysates, which hinted that these compounds may be the potential bioactive components of GBE with preventive effect against DN.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ginkgo biloba/química , Células Mesangiais/metabolismo , Extratos Vegetais/análise , Extratos Vegetais/metabolismo , Espectrometria de Massas em Tandem/métodos , Técnicas de Cultura de Células , Nefropatias Diabéticas , Glucose/metabolismo , Humanos , Reprodutibilidade dos Testes
20.
Chem Commun (Camb) ; 51(42): 8880-3, 2015 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-25925958

RESUMO

A sensitive and selective strategy for the colorimetric visualization of the total monomeric Aß down to 40 pg mL(-1) based on dual-functionalized gold nanoplasmonic particles (GNPs) is developed and applied to evaluate Aß levels in the AD cerebral system.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/análise , Encéfalo/metabolismo , Colorimetria , Ouro/química , Nanopartículas Metálicas/química , Peptídeos beta-Amiloides/metabolismo , Animais , Nanopartículas Metálicas/análise , Estrutura Molecular , Tamanho da Partícula , Ratos , Propriedades de Superfície
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