Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Angew Chem Int Ed Engl ; 62(13): e202217887, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36700493

RESUMO

Compared to γ-addition, the α-addition of α-branched ß,γ-unsaturated aldehydes faces larger steric hindrance and disrupts the π-π conjugation, which might be why very few examples are reported. In this article, a highly diastereo- and enantioselective α-regioselective Mannich reaction of isatin-derived ketimines with α-, ß- or γ-branched ß,γ-unsaturated aldehydes, generated in situ from Meinwald rearrangement of vinyl epoxides, is realized by using chiral N,N'-dioxide/ScIII catalysts. A series of chiral α-quaternary allyl aldehydes and homoallylic alcohols with vicinal multisubstituted stereocenters are constructed in excellent yields, good d.r. and excellent ee values. Experimental studies and DFT (density functional theory) calculations reveal that the large steric hindrance of the ligand and the Boc (tButyloxy carbonyl) protecting group of imines are critical factors for the α-regioselectivity.

2.
Immunopharmacol Immunotoxicol ; 44(2): 238-246, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35174751

RESUMO

BACKGROUND: Dioscin is reported to alleviate the dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in mice. Autophagy plays an anti-inflammatory role in UC. We herein aimed to explore the biological functions of dioscin in autophagy in UC. METHODS: To explore the effects of dioscin on UC progression, a DSS-induced mouse model of UC was established. Body weight, disease activity index and macroscopic damage index scores were recorded for seven days. Hematoxylin & Eosin (HE) staining was used to stain colon sections and an BX53 microscope was prepared to observe pathological changes. The activities of glutathione, superoxidative dismutase, and malondialdehyde were determined by commercially available kits. Western blotting was performed to measure the protein levels of p-AMPK/AMPK, p-mTOR/mTOR and autophagy-related genes. RESULTS: The DSS-induced colitis and oxidative stress in mice were ameliorated after dioscin treatment. Dioscin promoted the phosphorylation of AMPK to inhibit mTOR activation and facilitated autophagy in DSS-induced mice model of UC. CONCLUSION: Dioscin promotes autophagy by promoting the phosphorylation of AMPK to inhibit mTOR activation in ulcerative colitis.


Assuntos
Colite Ulcerativa , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Autofagia , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Colo/patologia , Sulfato de Dextrana/toxicidade , Diosgenina/análogos & derivados , Modelos Animais de Doenças , Camundongos , Serina-Treonina Quinases TOR
3.
Angew Chem Int Ed Engl ; 60(26): 14521-14527, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-33826200

RESUMO

The first catalytic asymmetric multiple vinylogous addition reactions initiated by Meinwald rearrangement of vinyl epoxides were realized by employing chiral N,N'-dioxide/ScIII complex catalysts. The vinyl epoxides, as masked ß,γ-unsaturated aldehydes, via direct vinylogous additions with isatins, 2-alkenoylpyridines or methyleneindolinones, provided a facile and efficient way for the synthesis of chiral 3-hydroxy-3-substituted oxindoles, α,ß-unsaturated aldehydes and spiro-cyclohexene indolinones, respectively with high efficiency and stereoselectivity. The control experiments and kinetic studies revealed that the Lewis acid acted as dual-tasking catalyst, controlling the initial rearrangement to match subsequent enantioselective vinylogous addition reactions. A catalytic cycle with a possible transition model was proposed to illustrate the reaction mechanism.

4.
Cytokine ; 106: 131-135, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29113741

RESUMO

Nonalcoholic fatty liver disease (NAFLD) commonly occurs in patients with type 2 diabetes mellitus (T2DM). C1q/TNF-related protein-3 (CTRP3) levels are decreased in type 2 diabetic patients. However, to date, it is unknown whether low CTRP3 level are correlated with the incidence of NAFLD. The aim of this study was to observe this association in Chinese patients with T2DM. Overall, 175 newly diagnosed T2DM were recruited in this study. The subjects were divided into NAFLD group (n=93) and control group (n=82). Anthropometric parameters, blood pressure, and several biochemical parameters were measured. The body composition was assessed with the bioelectrical impedance analysis (BIA) method. Insulin level was evaluated by radioimmunoassay. Levels of serum CTRP3 and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay. Our findings demonstrated that type 2 diabetic patients with NAFLD had lower levels of serum CTRP3 than did those without NAFLD (P=.002). Serum CTRP3 level was negatively correlated with body mass index (r=-0.271, P=.001), visceral fat area (r=-0.285, P<.001), glycosylated hemoglobin A1c (r=-0.270, P<.001), triglycerides (r=-0.267, P<.001), CRP (r=-0.222, P=.010), IL-6 (r=-0.212, P=.008), and HOMA-IR indices (r=-0.334, P<.001). When compared with the highest CTRP3 tertile, the odds ratio of the middle tertile for NAFLD incidence was 4.54 (95% CI, 1.53-13.47) and 5.80 (95% CI, 1.60-21.02) for the lowest tertile after adjustment for confounding factors. In summary, low serum CTRP3 is a strong predictor for the prevalence of NAFLD in Chinese patients with newly diagnosed T2DM.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/complicações , Fatores de Necrose Tumoral/sangue , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Razão de Chances
5.
Medicine (Baltimore) ; 102(37): e34368, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37713893

RESUMO

To investigate sexual dimorphism of serum pigment epithelium-derived factor (PEDF) and its influencing factors in healthy individuals. A total of 162 healthy people (69 males, 93 females) who underwent health examinations in our department were selected. Serum PEDF, estradiol and other metabolic indices were measured, and homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of ß-cell function (HOMA-ß) were calculated to evaluate insulin resistance and ß-cell function, respectively. Subjects were divided into < 50 years and ≥ 50 years groups to explore the sexual dimorphism of serum PEDF in different age groups. We found no statistically significant difference in serum PEDF levels between men and women in total. However, in the group of subjects under 50 years old, men had significantly higher PEDF levels than women (9.32 ±â€…2.07 µg/mL vs 8.24 ±â€…2.29 µg/mL, P < .05), and no sex difference was found in the ≥ 50 years group. In women, serum PEDF levels were significantly higher in subjects aged 50 years and over than in those younger than 50 years of age (9.56 ±â€…3.05 µg/mL vs 8.25 ±â€…2.30 µg/mL, P < .05). In men, there was no significant difference in serum PEDF levels between the 2 age groups. In women, correlation analysis showed that serum PEDF levels were significantly correlated with body mass index, waist circumference, diastolic blood pressure (DBP), 2-h postprandial glucose, fasting and 2-h postprandial insulin, HOMA-ß, HOMA-IR, aminotransferase, triacylglycerol, and estradiol. Elevated triacylglycerol and aminotransferase and decreased estradiol were significant predictors of increased PEDF concentrations in women. There is sexual dimorphism in circulating PEDF levels, which may be related to estrogen status.


Assuntos
Serpinas , Caracteres Sexuais , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estradiol , Proteínas do Olho , Resistência à Insulina , Serpinas/metabolismo
6.
Medicine (Baltimore) ; 102(26): e34053, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37390232

RESUMO

PURPOSE: To take a systematic bibliometric analysis and generate the knowledge mapping of diabetic foot research, basing on big data from Web of Science Core Collection (WoSCC) database. METHODS: Two authors retrieved the WoSCC independently, to obtain publications in field of diabetic foot. CiteSpace was used to detect the co-occurrence relationships of authors, keywords, institutions, and countries/regions, co-citation relationships of authors, references, and journals, and distribution of WoS category. RESULTS: A total of 10,822 documents were included, with 39,541 authors contributed to this field. "Armstrong DG," "Lavery LA," and "Lipsky BA" are the top 3 productive authors, and "Armstrong DG," "Boulton AJM," and "Lavery LA" were most commonly cited. The United States, England and China are the most productive countries, and Univ Washington, Univ Manchester and Harvard Univ published the largest quantity of articles. "Diabetes Care," "Diabetic Med," and "Diabetologia" are the most frequently cited journals, providing the greatest knowledge base. Clustering analysis of keywords co-occurrence map presented the following hotspots: #1 diabetic wound healing, #2 diabetic polyneuropathy, #3 plantar pressure, #4 diabetic foot infection, #5 endovascular treatment, and #6 hyperbaric oxygen therapy. CONCLUSION: This study performed a global overview of diabetic foot research using bibliometric and visualization methods, which would provide helpful references for researchers focusing on this area to capture the future trend.


Assuntos
Diabetes Mellitus , Pé Diabético , Neuropatias Diabéticas , Humanos , Bibliometria , Big Data , China
7.
Exp Biol Med (Maywood) ; 247(2): 174-183, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34601891

RESUMO

Hyperuricemia, which contributes to vascular endothelial damage, plays a key role in multiple cardiovascular diseases. This study was designed to investigate whether C1q/tumor necrosis factor (TNF)-related protein 3 (CTRP3) has a protective effect on endothelial damage induced by uric acid and its underlying mechanisms. Animal models of hyperuricemia were established in Sprague-Dawley (SD) rats through the consumption of 10% fructose water for 12 weeks. Then, the rats were given a single injection of Ad-CTRP3 or Ad-GFP. The animal experiments were ended two weeks later. In vitro, human umbilical vein endothelial cells (HUVECs) were first infected with Ad-CTRP3 or Ad-GFP. Then, the cells were stimulated with 10 mg/dL uric acid for 48 h after pretreatment with or without a Toll-like receptor 4 (TLR4)-specific inhibitor. Hyperuricemic rats showed disorganized intimal structures, increased endothelial apoptosis rates, increased inflammatory responses and oxidative stress, which were accompanied by reduced CTRP3 and elevated TLR4 protein levels in the thoracic aorta. In contrast, CTRP3 overexpression decreased TLR4 protein levels and ameliorated inflammatory responses and oxidative stress, thereby improving the morphology and apoptosis of the aortic endothelium in rats with hyperuricemia. Similarly, CTRP3 overexpression decreased TLR4-mediated inflammation, reduced oxidative stress, and rescued endothelial damage induced by uric acid in HUVECs. In conclusion, CTRP3 ameliorates uric acid-induced inflammation and oxidative stress, which in turn protects against endothelial injury, possibly by inhibiting TLR4-mediated inflammation and downregulating oxidative stress.


Assuntos
Adipocinas/metabolismo , Apoptose , Endotélio Vascular/lesões , Endotélio Vascular/metabolismo , Estresse Oxidativo , Ácido Úrico/metabolismo , Animais , Humanos , Inflamação/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Receptor 4 Toll-Like/metabolismo
8.
Tissue Cell ; 72: 101595, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34303283

RESUMO

OBJECTIVES: The incidence of metabolic associated fatty liver disease (MAFLD) induced by high fructose consumption is dramatically increasing in the world while lacking specifically therapeutic drugs. The present study aimed to investigate the effect of complement C1q/tumor necrosis factor-related protein-3 (CTRP3) on fructose-induced MAFLD and its potential mechanisms. METHOD: The animal models with MAFLD were built with Sprague-Dawley (SD) rats drinking 10 % fructose solution for 12 weeks. Then, specific hepatic CTRP3 overexpression was conducted by a single caudal-vein injection of CTRP3-expressing adenoviruses. Rats were sacrificed two weeks later. RESULTS: Drinking 10 % fructose solution for 12 weeks successfully built the rats models with MAFLD. Fructose feeding markedly decreased hepatic CTRP3 expression in rats. However, CTRP3 overexpression in liver alleviated hyperuricemia, dyslipidemia, liver function injury, intrahepatic triglyceride (TG) accumulation and histological changes of hepatic steatosis in rats fed with fructose. CTRP3 overexpression also inhibited hepatic XO activity in liver and improved subsequent oxidative stress, accompanied with downregulation of gene expression of sterol-regulatory element binding protein 1c (SERBP-1c) and fatty acid synthase (FAS). CONCLUSION: CTRP3 attenuates MAFLD induced by fructose, which maybe partially attribute to rescued oxidative stress related with xanthine oxidase overactivity.


Assuntos
Adipocinas/metabolismo , Fígado Gorduroso/enzimologia , Fígado Gorduroso/patologia , Estresse Oxidativo , Xantina Oxidase/metabolismo , Animais , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Fígado Gorduroso/sangue , Comportamento Alimentar , Frutose , Lipídeos/sangue , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Ácido Úrico/sangue
9.
J Food Prot ; 84(8): 1446-1454, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33852731

RESUMO

ABSTRACT: Pseudomonas fluorescens is a specific spoilage microorganism of refrigerated marine fish, and is highly adapted to low temperature. Cold shock proteins (CSPs) play an important role in cold adaptation of bacteria. In this study, CSP genes were identified from the genome of P. fluorescens PF08 by search of the conserved domain of CSPs with HMMER software, and the CSP physicochemical properties, structures, and functions were analyzed through bioinformatics. Five typical CSPs were identified in the P. fluorescens PF08 genome (PfCSPs). All five PfCSPs are small hydrophilic acidic proteins with a molecular mass of ca. 7.4 kDa. They are located in the cytoplasm and are nonsecretory and nontransmembrane proteins. Multiple sequence alignment analysis indicated that the CSPs are highly conserved between species, especially in DNA-binding sites and RNA-binding motifs that can bind to single-stranded DNA and RNA. The five PfCSPs clustered with CspD from Escherichia coli and Salmonella Typhimurium, which suggests a close homology and high functional similarity among the five PfCSPs and CspD. The secondary and tertiary structures of the PfCSPs are in accordance with the characteristics of the CSP family, and ligand binding sites with higher likelihood were found in PfCSPs. The five PfCSPs were predicted to interact with some of the same proteins that are involved in virulence, stress responses (including to low temperature), cell growth, ribosome assembly, and RNA degradation. The results provide further elucidation of the function of CSPs in adaptation to low temperatures by P. fluorescens.


Assuntos
Proteínas e Peptídeos de Choque Frio , Pseudomonas fluorescens , Sequência de Aminoácidos , Animais , Proteínas de Bactérias , Temperatura Baixa , Simulação por Computador , Proteínas de Choque Térmico , Pseudomonas fluorescens/genética
10.
Exp Clin Endocrinol Diabetes ; 129(4): 314-321, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31683330

RESUMO

OBJECTIVE: The present study was aimed to reveal the relationship between uric acid and fructose-induced obesity hypertension and its mechanisms. METHODS: A rat model with obesity hypertension was induced by a high-fructose diet. In the experiment I, the rats were fed with fructose for 8 wks along with allopurinol or benzbromarone at the beginning. In the experiment II, the rats were fed with fructose for 8 wks firstly. And then, these rats were treated with allopurinol or benzbromarone for additional 6 wks. RESULTS: Fructose-fed rats showed hyperuricemia, abdominal obesity hypertension and an activation in adipose renin-angiotensin system (RAS). Also, fructose-fed rats had higher levels of proinflammatory cytokines and more macrophages infiltrating in adipose tissue. In the experiment I, allopurinol and benzbromarone significantly reduced serum uric acid at 8 wk. Adipose RAS overactivation, adipose inflammatory responses and the development of obesity hypertension were all effectively prevented by hyperuricemia inhibition. In the experiment II, 6-wk treatment with allopurinol and benzbromarone significantly decreased serum uric acid, downregulated adipose RAS, abolished adipose inflammation and improved obesity hypertension. CONCLUSION: In conclusion, urate-lowering therapy protects rats against fructose-induced obesity hypertension. The mechanisms appear to be via downregulated adipose RAS and reduced inflammation in adipose tissue.


Assuntos
Tecido Adiposo , Alopurinol/farmacologia , Benzobromarona/farmacologia , Dieta da Carga de Carboidratos/efeitos adversos , Frutose/efeitos adversos , Supressores da Gota/farmacologia , Hipertensão , Hiperuricemia , Inflamação , Obesidade Abdominal , Sistema Renina-Angiotensina , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/imunologia , Alopurinol/administração & dosagem , Animais , Benzobromarona/administração & dosagem , Modelos Animais de Doenças , Frutose/administração & dosagem , Supressores da Gota/administração & dosagem , Hipertensão/etiologia , Hipertensão/prevenção & controle , Hiperuricemia/sangue , Hiperuricemia/tratamento farmacológico , Hiperuricemia/etiologia , Inflamação/sangue , Inflamação/etiologia , Inflamação/imunologia , Inflamação/prevenção & controle , Masculino , Obesidade Abdominal/induzido quimicamente , Obesidade Abdominal/complicações , Obesidade Abdominal/prevenção & controle , Ratos , Ratos Sprague-Dawley
11.
Comput Methods Programs Biomed ; 196: 105650, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32682092

RESUMO

BACKGROUND AND OBJECTIVE: In flicker-based steady-state visual evoked potentials (SSVEP) brain-computer interface (BCI), the system performance decreases due to prolonged repeated visual stimulation. To reduce the performance decrease due to visual fatigue, the zoom motion based steady-state motion visual evoked potentials (SSMVEPs) paradigm had been proposed. In this study, the stimulation parameters of the paradigm are optimised to mitigate the decrease in detection accuracy for SSMVEP due to visual fatigue. METHODS: Eight zoom motion-based SSMVEP paradigms with different stimulation parameters were compared. The graph size, luminance, colour, and shape, as well as the frequency range and interval of the stimulation and refresh rate of the screen was changed to determine the optimal paradigm with high recognition accuracy and reduced fatigue effects. The signal-to-noise ratio (SNR) of SSMVEP was also calculated for four fatigue levels. Moreover, the power spectral density of electroencephalograph (EEG) alpha and theta bands during ongoing activity was calculated for the stimulation experiment to evaluate fatigue at the start and end of the stimulation task. RESULTS: All stimulation SSMVEP paradigms exhibited high accuracies. Changes in luminance, colour, and shape did not impact the recognition accuracy, nor did a higher stimulation frequency or lower frequency interval of each stimulation block. However, the paradigm with smaller stimulus achieved the highest average target selection accuracy of 97.2%, compared to 94.9% for the standard paradigm. Furthermore, it exhibited almost zero reduction in recognition accuracy due to fatigue. From fatigue level 1 to level 4, the smaller zoom motion-based SSMVEP exhibited a lower decrease in the SNR of SSMVEP and a lower alpha/theta ratio decrease during ongoing stimulation activity compared to the standard paradigm. CONCLUSIONS: For a zoom motion-based SSMVEP paradigm, changing multiple stimulation parameters can lead to the same high performance as the standard paradigm. Moreover, using a smaller stimulus can reduce the accuracy decrease caused by fatigue because the SNR decrease in the evoked SSMVEP state was negligible and the alpha/theta index decrease during ongoing activity was lower than that for the standard paradigm.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia , Potenciais Evocados Visuais , Movimento (Física) , Estimulação Luminosa
12.
Org Lett ; 22(1): 93-97, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31833774

RESUMO

A highly enantioselective 1,3-dipolar cycloaddition of meso-diaziridines with chalcones was realized by utilizing the ScIII-N,N'-dioxide complex as the catalyst. In this transformation, the 1,3-dipole intermediates generated from the C-N bond cleavage of diaziridine were trapped by chiral N,N'-dioxide/scandium(III) complex activated chalcones to undergo enantioselective 1,3-dipolar cycloaddition. A range of chiral 1,5-diazabicylo[3.3.0]octane derivatives were readily synthesized in good yields with high diastereo- and enantioselectivities.

13.
Ann Transl Med ; 8(22): 1526, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33313271

RESUMO

Tumor immunotherapy, especially that involving programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) immunosuppressive checkpoint inhibitors, has become an important part of tumor treatment strategy in the past decade. Blocking PD-1/PD-L1 signaling pathway can reduce the inhibitory effect of PD-1 pathway on T cells, promote the anti-tumor activity of activated T cells, and prolong the remission period of tumor. While PD-1/PD-L1 immunotherapy is effective in the treatment of solid malignant tumors, it also has shortcomings, due to the complexity of the tumor microenvironment (TME). Regulatory T cells (Tregs) and T helper 17 (Th17) cells play an important role in the TME and are closely related to the occurrence and development of tumors. Tregs can inhibit the anti-tumor immune effect, while Th17 cells play a dual role in tumor immunity, which not only promotes tumorigenesis but also promotes anti-tumor immunity. In the occurrence and development of tumor, PD-1/PD-L1 pathway, Tregs and Th17 cells are interrelated. However, the complicated relationship between the PD-1/PD-L1 pathway, Tregs, and Th17 cells has not been fully clarified. Here, we summarize the immunoregulation mechanisms and discuss the crosstalk between the PD-1/PD-L1 pathway, Tregs, and Th17 cells, with the aim of providing novel insights for future cancer treatment.

14.
Front Neurosci ; 14: 886, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982674

RESUMO

Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by deficits in communication, impaired social interaction, and repetitive or restricted interests and behaviors. We have recently shown that neuronal nitric oxide synthase (nNOS) expression was reduced in the basolateral amygdala of mice after postnatal valproic acid exposure. However, the specific role of nNOS downregulation in mice remains to be elucidated. Herein, we investigated the behavioral alternations of naive mice with a recombinant adeno-associated virus (rAAV)-mediated knockdown of nNOS in a comprehensive test battery, including the social interaction, marble burying, self-grooming, and open field tests. Further, the electrophysiological and surface expression changes induced by nNOS deficiency of the basolateral amygdala in these animals were examined. Our results show that nNOS knockdown displayed typical symptoms of ASD-like behaviors, such as reduced social interaction and communication, elevated stereotypes, and anxiety in mice. Surprisingly, we found that nNOS knockdown exhibited greatly reduced excitatory synaptic transmission concomitant with the lower surface expression of GluN2B-containing N-methyl-D-aspartate receptors and postsynaptic density protein 95 in mice. These findings support a notion that dysregulation of nNOS might contribute to ASD-associated phenotypes, with disease pathogenesis most likely resulting from deficits in excitatory synaptic transmission.

15.
Biochimie ; 162: 125-133, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31002842

RESUMO

Both hyperuricemia and adipose tissue renin-angiotensin system (RAS) are closely associated with multiple metabolic and cardiovascular diseases. We previously reported that uric acid could upregulate tissue RAS in adipocytes. In the present study, we aimed to reveal the involvement of toll-like receptors (TLRs) in uric acid-induced RAS activation in adipose tissue. A hyperuricemia rat model fed with a high-fructose diet and rat primary adipocytes were used in this study. Here, we inhibited TLR2 and TLR4 expression in adipose tissue and cultured adipocytes using small interfering RNA (siRNA). We found that high fructose-fed rats had hyperuricemia, higher body weight and greater adipose tissue content. We also found that hyperuricemia rats had raising blood pressure, higher expression levels of inflammatory cytokines and RAS components in adipose tissue, which could be prevented by TLR2/4-siRNA infection. In vitro study, uric acid caused a dose- and time-dependent increase in the mRNA expression of TLR2 and TLR4 in rat adipocytes. Uric acid could increase inflammatory cytokines and upregulate tissue RAS in rat adipocytes, which were both blocked with TLR2/4-siRNA infection. TNF-α and IL-6 could also result in an activation of tissue RAS expression in adipocytes. In conclusion, TLR2/4 mediated adipose inflammation plays a key role in RAS activation induced by uric acid in adipose tissue.


Assuntos
Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Hiperuricemia/metabolismo , Sistema Renina-Angiotensina , Receptor 2 Toll-Like/fisiologia , Receptor 4 Toll-Like/fisiologia , Adipócitos/citologia , Tecido Adiposo/citologia , Animais , Dieta da Carga de Carboidratos , Modelos Animais de Doenças , Frutose/metabolismo , Interleucina-6/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismo , Ácido Úrico/metabolismo
16.
Toxicol Lett ; 305: 51-57, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30710622

RESUMO

Apelin-13, a novel adipocytokine, is found to be a powerful antioxidant. Our previous work reported that uric acid could induce oxidative stress via an activation of renin-angiotensin system (RAS) in 3T3-L1 adipocytes. In the present study, we tried to observe the effect of apelin-13 on uric acid-induced oxidative stress. We also tried to reveal the potential mechanisms. In vivo, the rats were fed with 60% fructose diet for 8 weeks to produce hyperuricemia. Then, the hyperuricemia rats were intraperitoneally injected with apelin-13 for 2 weeks or 12 weeks. In vitro, 3T3-L1 adipocytes were treated with apelin-13 in the presence of 600 µmol/L uric acid for 48 h. When injected with apelin-13 for 12 weeks, the hyperuricemia rats had ameliorated oxidative stress, downregulated RAS components and upregulated angiotensin type 1 receptor related protein (APJ) expression in adipose tissue. Serum uric acid levels were also decreased after treatment. However, 2-week apelin-13 treatment had no obvious effect on the rats with hyperuricemia. Consistent with the findings in vivo, in vitro study, apelin-13 could ameliorate oxidative stress, decrease tissue RAS components, and increase APJ expression in 3T3-L1 adipocytes stimulated by uric acid. In conclusion, apelin-13 reduces uric acid-induced oxidative stress in adipose tissue, maybe through the inhibition of adipose RAS expression.


Assuntos
Hiperuricemia/induzido quimicamente , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Sistema Renina-Angiotensina/efeitos dos fármacos , Ácido Úrico/sangue , Ácido Úrico/urina , Células 3T3-L1 , Tecido Adiposo , Animais , Carboidratos da Dieta/administração & dosagem , Carboidratos da Dieta/efeitos adversos , Regulação para Baixo/efeitos dos fármacos , Frutose/administração & dosagem , Frutose/efeitos adversos , Masculino , Camundongos , Ratos , Ratos Sprague-Dawley
17.
Org Lett ; 21(6): 1632-1636, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30830792

RESUMO

An efficient asymmetric vinylogous Michael-aldol domino reaction between α-arylidene pyrazolinones and ß,γ-unsaturated-α-ketoesters catalyzed by a chiral N, N'-dioxide-ScIII complex in aqueous media has been established. A variety of spirocyclohexene pyrazolones with three stereocenters including vicinal tetrasubstituted stereocenters were obtained in excellent yields with good diastereoselectivities and enantioselectivities. A retro-aldol process was observed, which led to epimerization at the spirocyclic quaternary carbon center.

18.
Org Lett ; 20(18): 5601-5605, 2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30183317

RESUMO

A catalytic asymmetric nucleophilic addition of tertiary carbon nucleophiles to 2 H-azirines was established in the presence of the chiral N,N'-dioxide/CuII complex. Various chiral aziridines with vicinal tetrasubstituted stereocenters were obtained in high yields with excellent diastereoselectivities and enantioselectivities. Moreover, on the basis of the control experiments, X-ray structures of the products, and catalyst, a possible transition state was proposed to explain the stereoselectivity.

19.
Chem Commun (Camb) ; 54(88): 12511-12514, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30345434

RESUMO

The catalytic asymmetric ene-type reactions of vinylogous hydrazone were accomplished by using chiral N,N'-dioxide-metal salt complexes as catalysts. A wide range of electrophiles, including isatins, α-ketoester, imines, and aldehydes reacted with (E)-2-methyl-N-(piperidin-1-yl)prop-2-en-1-imine efficiently, affording the corresponding homoallylic alcohols and amines in high yields (up to 99%) with excellent ee values (up to 99%). The methodology provided a convenient way to synthesize bioactive chiral α-methylene-γ-butyrolactone derivatives.

20.
Ann Clin Lab Sci ; 47(1): 29-35, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28249913

RESUMO

Subclinical hypothyroidism (SH) is associated with hypercoagulability and hypofibrinolysis. The objective of this study was to assess the effect of L-thyroxine (L-T4) treatment and to evaluate changes in the hemostatic abnormalities of patients with varying severities of SH. We measured tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), D-dimer (DDI), fibrinogen (FIB), platelet counts (PLT), mean platelet volume (MPV), platelet distribution width (PDW), activated partial thromboplastin time (APTT), and prothrombin time (PT) in 149 female subjects. The prospective study included 54 patients in the control group, 53 patients with 4.2 µIU/mL

Assuntos
Hemostasia , Hipotireoidismo/sangue , Hipotireoidismo/tratamento farmacológico , Tiroxina/uso terapêutico , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Tireotropina/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA