Chemerin receptor blockade improves vascular function in diabetic obese mice via redox-sensitive and Akt-dependent pathways.

Chemerin and its G protein-coupled receptor [chemerin receptor 23 (ChemR23)] have been associated with endothelial dysfunction, inflammation, and insulin resistance. However, the role of chemerin on insulin signaling in the vasculature is still unknown. We aimed to determine whether chemerin reduces vascular insulin signaling and whether there is interplay between chemerin/ChemR23, insulin resistance, and vascular complications associated with type 2 diabetes (T2D). Molecular and vascular mechanisms were probed in mesenteric arteries and cultured vascular smooth muscle cells (VSMCs) from C57BL/6J, nondiabetic lean db/m, and diabetic obese db/db mice as well as in human microvascular endothelial cells (HMECs). Chemerin decreased insulin-induced vasodilatation in C57BL/6J mice, an effect prevented by CCX832 (ChemR23 antagonist) treatment. In VSMCs, chemerin, via oxidative stress- and ChemR23-dependent mechanisms, decreased insulin-induced Akt phosphorylation, glucose transporter 4 translocation to the membrane, and glucose uptake. In HMECs, chemerin decreased insulin-activated nitric oxide signaling. AMP-activated protein kinase phosphorylation was reduced by chemerin in both HMECs and VSMCs. CCX832 treatment of db/db mice decreased body weight, insulin, and glucose levels as well as vascular oxidative stress. CCX832 also partially restored vascular insulin responses in db/db and high-fat diet-fed mice. Our novel in vivo findings highlight chemerin/ChemR23 as a promising therapeutic target to limit insulin resistance and vascular complications associated with obesity-related diabetes. NEW & NOTEWORTHY Our novel findings show that the chemerin/chemerin receptor 23 axis plays a critical role in diabetes-associated vascular oxidative stress and altered insulin signaling. Targeting chemerin/chemerin receptor 23 may be an attractive strategy to improve insulin signaling and vascular function in obesity-associated diabetes.

Atorvastatin Attenuates Vascular Remodeling in Mice with Metabolic Syndrome. / Atorvastatina Atenua o Remodelamento Vascular em Camundongos com Síndrome Metabólica.

BACKGROUND: Metabolic syndrome is characterized by an array of comorbidities. During this syndrome, structural changes are observed in the cardiovascular system, especially vascular remodeling. One of the predisposing causes for these changes is chronic inflammation resulting from changes in the structure and composition of perivascular adipose tissue. Atorvastatin is effective in the treatment of dyslipidemias. However, its pleiotropic effects have not been completely understood. We hypothesize that metabolic syndrome may lead to vascular remodeling and that atorvastatin therapy may be able to attenuate this condition. OBJECTIVES: To assess the effects of atorvastatin therapy on vascular remodeling in an experimental model of metabolic syndrome. METHODS: Swiss mice received a control diet or a hyperglicemic diet for 18 weeks. After 14 weeks of diet, mice were treated with vehicle or atorvastatin (20mg/kg) during for 4 weeks. Nutritional and metabolic profiles were assessed by biochemical tests; moreover, a histological assessment of aorta structure was conducted, and cytokine levels were determined by the immunoenzyme assay. The acceptable level of significance for the results was set at p<0.05. RESULTS: Hyperglicemic diet promoted the development of metabolic syndrome. It indeed culminated in hypertrophic remodeling of vascular smooth muscle and perivascular adipose tissue. Furthermore, there were increases in the levels of circulating TNF-α and IL-6 and in the perivascular adipose tissue. Atorvastatin therapy significantly reduced metabolic damages, vascular remodeling, and cytokine levels. CONCLUSION: Atorvastatin attenuate metabolic damages associated with metabolic syndrome induced by hyperglycemic diet, in addition to attenuating vascular remodeling; both effects are associated with reduced levels of pro-inflammatory cytokines.

FUNDAMENTO: A síndrome metabólica é caracterizada por um conjunto de comorbidades. Durante a síndrome, observam-se alterações estruturais no sistema cardiovascular, especialmente o remodelamento vascular. Uma das causas predisponentes para essas alterações é a inflamação crônica oriunda de mudanças na estrutura e composição do tecido adiposo perivascular. Atorvastatina é eficaz no tratamento das dislipidemias. No entanto, seus efeitos pleiotrópicos não são totalmente compreendidos. Supõe-se que, durante a síndrome metabólica, ocorre remodelamento vascular e que o tratamento com atorvastatina pode ser capaz de atenuar tal condição. OBJETIVOS: Avaliar os efeitos do tratamento com atorvastatina sobre o remodelamento vascular em modelo experimental de síndrome metabólica. MÉTODOS: Camundongos Swiss receberam dieta controle ou dieta hiperglicídica por 18 semanas. Após 14 semanas de dieta, os camundongos foram tratados com veículo ou atorvastatina (20mg/kg) durante 4 semanas. Foram avaliados o perfil nutricional e metabólico por testes bioquímicos; análise estrutural da artéria aorta por histologia e dosagem de citocinas por ensaio imunoenzimático. O nível de significância aceitável para os resultados foi p <0,05. RESULTADOS: A dieta hiperglicídica promoveu o desenvolvimento de síndrome metabólica. Tal fato culminou no remodelamento hipertrófico do músculo liso vascular e tecido adiposo perivascular. Além disso, houve aumentos das citocinas TNF-α e IL-6 circulantes e no tecido adiposo perivascular. O tratamento com atorvastatina reduziu significativamente os danos metabólicos, o remodelamento vascular e os níveis de citocinas. CONCLUSÃO: Atorvastatina ameniza danos metabólicos associados à síndrome metabólica induzida por dieta hiperglicídica, além de atenuar o remodelamento vascular, sendo esses efeitos associados à redução de citocinas pró-inflamatórias.

Activation of PI3K/Akt pathway mediated by estrogen receptors accounts for estrone-induced vascular activation of cGMP signaling.

Estrone (E1) produces remarkable vascular effects, including relaxation, modulation of proliferation, apoptosis and cell adhesion. This study investigated the role of estrogen receptors and endothelial signaling pathways in the vascular relaxation promoted by E1. Aortic rings from male Wistar rats (250-300 g) were contracted with phenylephrine and stimulated with graded concentrations of E1. The concentration-dependent relaxation induced by E1 was abolished after removal of the endothelium or incubation with the estrogen receptor antagonist ICI 182,780. G protein-coupled estrogen receptor antagonism did not alter the E1 effect. Pretreatment of endothelium-intact arteries with inhibitors of nitric oxide synthase, guanylyl cyclase, calmodulin (CaM) and PI3K reduced the E1-induced vasorelaxation. Incubation with inhibitors of the MEK/ERK1/2 or p38MAPK pathways did not alter the E1 vasorelaxation. Similarly, inhibition of cyclooxygenase or blockade of potassium channels did not change the E1 effect. Western blot analysis evidenced that E1 induces phosphorylation of eNOS, PI3K and Akt in rat aorta. Our data demonstrate that E1 induces aortic vascular relaxation through classic estrogen receptors activation on the endothelium. We also identify CaM and PI3K/Akt pathways as critical mediators of the NO-cGMP signaling activation by E1. These findings contribute to the notion that this estrogen regulates arterial function and represents another link, besides 17ß-estradiol (E2), between postmenopause and vascular dysfunction.

Atorvastatina Atenua o Remodelamento Vascular em Camundongos com Síndrome Metabólica / Atorvastatin Attenuates Vascular Remodeling in Mice with Metabolic Syndrome

Resumo Fundamento A síndrome metabólica é caracterizada por um conjunto de comorbidades. Durante a síndrome, observam-se alterações estruturais no sistema cardiovascular, especialmente o remodelamento vascular. Uma das causas predisponentes para essas alterações é a inflamação crônica oriunda de mudanças na estrutura e composição do tecido adiposo perivascular. Atorvastatina é eficaz no tratamento das dislipidemias. No entanto, seus efeitos pleiotrópicos não são totalmente compreendidos. Supõe-se que, durante a síndrome metabólica, ocorre remodelamento vascular e que o tratamento com atorvastatina pode ser capaz de atenuar tal condição. Objetivos Avaliar os efeitos do tratamento com atorvastatina sobre o remodelamento vascular em modelo experimental de síndrome metabólica. Métodos Camundongos Swiss receberam dieta controle ou dieta hiperglicídica por 18 semanas. Após 14 semanas de dieta, os camundongos foram tratados com veículo ou atorvastatina (20mg/kg) durante 4 semanas. Foram avaliados o perfil nutricional e metabólico por testes bioquímicos; análise estrutural da artéria aorta por histologia e dosagem de citocinas por ensaio imunoenzimático. O nível de significância aceitável para os resultados foi p <0,05. Resultados A dieta hiperglicídica promoveu o desenvolvimento de síndrome metabólica. Tal fato culminou no remodelamento hipertrófico do músculo liso vascular e tecido adiposo perivascular. Além disso, houve aumentos das citocinas TNF-α e IL-6 circulantes e no tecido adiposo perivascular. O tratamento com atorvastatina reduziu significativamente os danos metabólicos, o remodelamento vascular e os níveis de citocinas. Conclusão Atorvastatina ameniza danos metabólicos associados à síndrome metabólica induzida por dieta hiperglicídica, além de atenuar o remodelamento vascular, sendo esses efeitos associados à redução de citocinas pró-inflamatórias.

Abstract Background Metabolic syndrome is characterized by an array of comorbidities. During this syndrome, structural changes are observed in the cardiovascular system, especially vascular remodeling. One of the predisposing causes for these changes is chronic inflammation resulting from changes in the structure and composition of perivascular adipose tissue. Atorvastatin is effective in the treatment of dyslipidemias. However, its pleiotropic effects have not been completely understood. We hypothesize that metabolic syndrome may lead to vascular remodeling and that atorvastatin therapy may be able to attenuate this condition. Objectives To assess the effects of atorvastatin therapy on vascular remodeling in an experimental model of metabolic syndrome. Methods Swiss mice received a control diet or a hyperglicemic diet for 18 weeks. After 14 weeks of diet, mice were treated with vehicle or atorvastatin (20mg/kg) during for 4 weeks. Nutritional and metabolic profiles were assessed by biochemical tests; moreover, a histological assessment of aorta structure was conducted, and cytokine levels were determined by the immunoenzyme assay. The acceptable level of significance for the results was set at p<0.05. Results Hyperglicemic diet promoted the development of metabolic syndrome. It indeed culminated in hypertrophic remodeling of vascular smooth muscle and perivascular adipose tissue. Furthermore, there were increases in the levels of circulating TNF-α and IL-6 and in the perivascular adipose tissue. Atorvastatin therapy significantly reduced metabolic damages, vascular remodeling, and cytokine levels. Conclusion Atorvastatin attenuate metabolic damages associated with metabolic syndrome induced by hyperglycemic diet, in addition to attenuating vascular remodeling; both effects are associated with reduced levels of pro-inflammatory cytokines.

Caryocar brasiliense induces vasorelaxation through endothelial Ca2+/calmodulin and PI3K/Akt/eNOS-dependent signaling pathways in rats

ABSTRACT Caryocar brasiliense Cambess., Caryocaraceae (pequi) is a typical Brazilian Cerrado tree. A previous study showed that the butanolic fraction of pequi leaves promotes endothelium-dependent relaxation mediated by nitric oxide and that it causes reversible hypotension in rats. In the present study, we investigated the cell signaling pathways associated with the butanolic fraction-induced nitric oxide release, and we characterized the chemical composition of its fraction. Vascular reactivity tests, a western blotting analysis, and a chemiluminescence assay were used to investigate the signaling pathways involved in the vasorelaxant effect of the butanolic fraction. Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry was used to characterize the butanolic fraction chemical composition. Vasorelaxation was mediated through the activation of the calmodulin and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways, leading to subsequent endothelial nitric oxide synthase phosphorylation and nitric oxide production, as evidenced by western blotting and chemiluminescence assays, respectively. The chemical characterization of the butanolic fraction revealed the presence of 72 oxygenated compounds, whose molecular formulae are compatible with phenolic compounds, suggesting a potential contribution of these compounds for the butanolic fraction vasorelaxant effect. These findings show that the calmodulin and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways are involved in the butanolic fraction-induced endothelial nitric oxide synthase activation and are promoted by polyphenol compounds present in the C. brasiliense leaves.

Prevalência de uropatógenos e perfil de sensibilidade aos antimicrobianos em pacientes ambulatoriais de Jataí-GO / Prevalence of uropathogens and antimicrobial susceptibility profile in outpatient from Jataí-GO

Introduction: Urinary tract infections (UTIs) affect people worldwide. Escherichia coli is the main agent of UTI, however the etiology may vary according to the age and sex of the patient. Regional variations in the prevalence and antimicrobial resistance should be considered for therapy choice. Objectives: This study aimed to conduct a survey on the main agents of UTI, and assess the resistance of these microorganisms, during the period of March 2010 to June 2012 in the city of Jataí-GO. Method: A retrospective cross-sectional study were performed, collecting data on the prevalence of uropathogens and their sensitivity profiles which were evaluated by disk diffusion method. Results: During this period, 2,181 urine cultures were evaluated, of which 510 (23.4%) were positive, predominantly female (81.4%) and aged between 21 and 64 years old (59.7%). The most frequently isolated microorganism was E. coli (61%), followed by Staphylococcus saprophyticus (9.4%), and Proteus (9.4%). The prevalence of these bacteria according to the patient sex has suffered a statistically significant change (p < 0.05). It was possible to detect high resistance rate of E. coli to some antibiotics of choice for UTI treatment, such as ampicillin (57.9 %), pipemidic acid (50.5 %), nalidixic acid (48.6 %), and trimethoprim-sulfamethoxazole (44.8%). Conclusion: These data demonstrate the need to know the reality of each region in order to establish an appropriate empirical therapy, when it is not possible to perform culture and antimicrobial susceptibility testing...

Introdução: Infecções do trato urinário (ITU) afetam pessoas em todo o mundo. Escherichia coli é o principal agente de ITU, no entanto a etiologia pode variar de acordo com o sexo e a idade do paciente. Variações regionais quanto à prevalência e à resistência aos antimicrobianos devem ser consideradas para a escolha terapêutica. Objetivos: Este trabalho teve por objetivo realizar um levantamento sobre os principais agentes de ITU e avaliar o perfil de resistência desses microrganismos no período de março de 2010 a junho de 2012, na cidade de Jataí-GO. Método: Estudo retrospectivo de corte transversal realizado por meio de coleta de dados sobre a prevalência de uropatógenos e seus perfis de sensibilidade avaliados pelo método da difusão. Resultados: Neste período, foram realizadas 2.181 uroculturas, das quais 510 (23,4%) apresentaram resultado positivo, sendo predominantemente do sexo feminino (81,4%) e com idade entre 21 e 64 anos de idade (59,7%). O microrganismo mais frequentemente isolado foi E. coli (61%), seguido de Staphylococcus saprophyticus (9,4%) e Proteus (9,4%). A prevalência dessas bactérias, de acordo com o sexo do paciente, sofreu variação estatisticamente significativa (p < 0,05). Foi possível constatar elevada taxa de resistência de E. coli para alguns antimicrobianos de primeira escolha para tratamento de ITU, como ampicilina (57,9%), ácido pipemídico (50,5%), ácido nalidíxico (48,6%) e sulfazotrim (44,8%). Conclusão: Esses dados demonstram a necessidade de se conhecer a realidade de cada região a fim de se estabelecer uma terapia empírica adequada, quando não for possível a realização da cultura e do antibiograma...

Candidúria em adultos e crianças: prevalência e suscetibilidade a antifúngicos em pacientes ambulatoriais de Jataí-GO / Candiduria in adults and children: prevalence and antifungal susceptibility in outpatient of Jataí-GO

Introduction: The term candiduria refers to the presence of yeast in urine and Candida albicans is the most common agent. In general, routine laboratories do not perform identification and cultivation of yeast. Objectives: To determine the prevalence of Candida species and to evaluate the antifungal susceptibility of the species isolated in urine of outpatients Jataí-GO, between January-October 2013. Material and method: Urine samples containing fungal structures were plated out on Sabouraud agar with chloramphenicol. Differentiation was taken with the urease test, nitrogen and carbon sources assimilation, germ tube test, morphology on cornmeal agar and chromogenic agar cultivation. Susceptibility was evaluated at antifungal itraconazole, fluconazole, amphotericin B and ketoconazole. Results: 1,215 urine tests were performed, and 64 had fungal structures (5.3%). Two samples were lost, thus here we considered 62 isolates. From this total, 43 were identified as C. albicans (67.2 %), eight C. glabrata (12.5 %), five C. krusei (7.8%), three C. tropicalis (4.7%), and three could not determine the species (4.7%). Amphotericin B and ketoconazole inhibited 94.9% of the isolates. On the other hand, 55.9% and 54.2 % were resistant to itraconazole and fluconazole, respectively. The resistance rates of both fluconazole and itraconazole for C. glabrata and C. albicans, as fluconazole for C. albicans and C. krusei, showed significant differences (p < 0.05). Conclusion: These data demonstrate the importance of conducting a full identification and susceptibility to antifungal agents in samples with yeast infection...

Introdução: O termo candidúria designa a presença de leveduras na urina e Candida albicans é o agente mais comum. Em geral, os laboratórios de rotina não realizam o cultivo e a identificação da levedura. Objetivos: Determinar a prevalência de espécies de Candida e avaliar o perfil de sensibilidade aos antifúngicos das espécies isoladas em urina de pacientes ambulatoriais do município de Jataí-GO, entre janeiro e outubro de 2013. Material e método: Amostras de urina que continham estruturas fúngicas foram semeadas em ágar Sabouraud com cloranfenicol. A diferenciação foi feita com provas da urease, assimilação de fontes de nitrogênio e carbono, tubo germinativo, morfologia em ágar fubá e cultivo em ágar cromogênico. Foi avaliada a sensibilidade aos antifúngicos itraconazol, fluconazol, anfotericina B e cetoconazol. Resultados: Foram realizados 1.215 exames de urina, sendo que 64 apresentaram estruturas fúngicas (5,3%). Houve perda de duas amostras, assim, considerou-se 62 isolados. Desse total, 43 foram identificadas como C. albicans (67,2%); oito, C. glabrata (12,5%); cinco, C. krusei (7,8%); três, C. tropicalis (4,7%); e em três não foi possível determinar a espécie (4,7%). Anfotericina B e cetoconazol inibiram 94,9% dos isolados. Por outro lado, 55,9% e 54,2%, respectivamente, apresentaram resistência a itraconazol e fluconazol. As taxas de resistência a itraconazol e fluconazol de C. glabrata e C. albicans e também do fluconazol entre C. albicans e C. krusei apresentaram diferenças significativas (p < 0,05). Conclusão: Os dados demonstram a importância de se realizar a identificação completa e também o antifungigrama para amostras que apresentam infecção por leveduras...