Protein disulfide isomerase-mediated transcriptional upregulation of Nox1 contributes to vascular dysfunction in hypertension.

Nox1 signaling is a causal key element in arterial hypertension. Recently, we identified protein disulfide isomerase A1 (PDI) as a novel regulatory protein that regulates Nox1 signaling in VSMCs. Spontaneously hypertensive rats (SHR) have increased levels of PDI in mesenteric resistance arteries compared with Wistar controls; however, its consequences remain unclear. Herein, we investigated the role of PDI in mediating Nox1 transcriptional upregulation and its effects on vascular dysfunction in hypertension. We demonstrate that PDI contributes to the development of hypertension via enhanced transcriptional upregulation of Nox1 in vascular smooth muscle cells (VSMCs). We show for the first time that PDI sulfenylation by hydrogen peroxide contributes to EGFR activation in hypertension via increased shedding of epidermal growth factor-like ligands. PDI also increases intracellular calcium levels, and contractile responses induced by ANG II. PDI silencing or pharmacological inhibition in VSMCs significantly decreases EGFR activation and Nox1 transcription. Overexpression of PDI in VSMCs enhances ANG II-induced EGFR activation and ATF1 translocation to the nucleus. Mechanistically, PDI increases ATF1-induced Nox1 transcription and enhances the contractile responses to ANG II. Herein we show that ATF1 binding to Nox1 transcription putative regulatory regions is augmented by PDI. Altogether, we provide evidence that HB-EGF in SHR resistance vessels promotes the nuclear translocation of ATF1, under the control of PDI, and thereby induces Nox1 gene expression and increases vascular reactivity. Thus, PDI acts as a thiol redox-dependent enhancer of vascular dysfunction in hypertension and could represent a novel therapeutic target for the treatment of this disease.

Regionalização: perspectivas, desafios e possibilidades no estado do Rio de Janeiro / Regionalization: perspectives, challenges and possibilities in the state of Rio of January

A complexidade do processo de regionalização enquanto estratégia operativa do processo de descentralização de ações e serviços no SUS, e sua importância para organização de redes de atenção à saúde regionais com resolutividade, propõem um olhar para o processo de regionalização no âmbito do estado do Rio de Janeiro, com foco nas perspectivas, desafios e possibilidades da organização de redes regionais de atenção à saúde. (AU)

Avaliação das Redes de Atenção à Saúde: um estudo sobre o atributo da coordenação assistencial / Evaluation of Health Care Networks: a study on the atribute of care coordination

O Relatório Dawson, publicado em 1920, pode ser considerado uma das bases do modelo proposto pelos sistemas nacionais de saúde, pois apresentou a organização dos serviços de saúde de forma regionalizada, a partir da necessidade de saúde da população, sob comando único de uma autoridade sanitária local. Essa ideia embasou a construção do conceito de Redes de Atenção à Saúde (RAS). Em 2008, a OPAS teceu recomendações para os sistemas de saúde na América Latina, para organização de RAS como caminho para superar a fragmentação. Foram apresentados os 13 atributos essenciais da RAS, dentre os quais se destaca a existência de mecanismos de coordenação assistencial ao longo do continuum de serviços de saúde. O presente trabalho tem por objetivo explorar abordagens e instrumentos para avaliação da coordenação assistencial em sistemas nacionais. Foi realizado um estudo de caráter exploratório, que inclui pesquisa de literatura e documental, desenvolvendo um percurso conceitual acerca dos temas redes de atenção à saúde e coordenação assistencial. Sendo a coordenação assistencial um conceito polissêmico, utilizaram-se neste trabalho as definições dadas por Terraza Núñez (2004) e Vargas (2015), que propõem a distinção de três componentes da coordenação assistencial: Coordenação Administrativa; a Gestão Clínica; e a Coordenação da Informação. Na revisão realizada, ficou evidenciado que há diferentes instrumentos com objetivos de avaliar aspectos distintos da coordenação, bem como diferentes perspectivas a serem consideradas, dependendo do nível de gestão que se considera. No processo avaliativo, a diferenciação dos componentes da coordenação é fundamental não apenas para compreender os processos estudados, como para elaborar estratégias de intervenção e identificar as diferentes responsabilidades de gestão.

The Dawson Report, published in 1920, can be considered one of the bases of the model proposed by the national health systems, as it presented the organization of health services in a regionalized way, based on the health needs of the population, under a single command of an authority. local sanitary. This idea was the basis for the construction of the concept of Health Care Networks (RAS). In 2008, PAHO made recommendations for health systems in Latin America to organize RAS as a way to overcome fragmentation. The 13 essential attributes of RAS were presented, among which the existence of assistance coordination mechanisms along the continuum of health services stands out. The present work aims to explore approaches and instruments for evaluating care coordination in chosen national systems. An exploratory study was carried out, which includes literature and document research, a conceptual course on the themes of health care networks and care coordination. As care coordination is a polysemic concept, the definitions presented by Terraza Núñez (2004) and Vargas (2015) were used in this work, which propose the distinction of three components of care coordination: Administrative Coordination; Clinical Management; and Information Coordination. In the review carried out, it became evident that there are different instruments with the objective of evaluating different aspects of coordination, as well as different perspectives to be considered in the evaluation, depending on the management level considered. In the evaluation process, the differentiation of the coordination components is fundamental not only to understand the studied processes, but also to make up intervention strategies and identify the different management responsibilities.

Amblyomma sculptum Salivary Protease Inhibitors as Potential Anti-Tick Vaccines.

Amblyomma sculptum is the main tick associated with human bites in Brazil and the main vector of Rickettsia rickettsii, the causative agent of the most severe form of Brazilian spotted fever. Molecules produced in the salivary glands are directly related to feeding success and vector competence. In the present study, we identified sequences of A. sculptum salivary proteins that may be involved in hematophagy and selected three proteins that underwent functional characterization and evaluation as vaccine antigens. Among the three proteins selected, one contained a Kunitz_bovine pancreatic trypsin inhibitor domain (named AsKunitz) and the other two belonged to the 8.9 kDa and basic tail families of tick salivary proteins (named As8.9kDa and AsBasicTail). Expression of the messenger RNA (mRNA) encoding all three proteins was detected in the larvae, nymphs, and females at basal levels in unfed ticks and the expression levels increased after the start of feeding. Recombinant proteins rAs8.9kDa and rAsBasicTail inhibited the enzymatic activity of factor Xa, thrombin, and trypsin, whereas rAsKunitz inhibited only thrombin activity. All three recombinant proteins inhibited the hemolysis of both the classical and alternative pathways; this is the first description of tick members of the Kunitz and 8.9kDa families being inhibitors of the classical complement pathway. Mice immunization with recombinant proteins caused efficacies against A. sculptum females from 59.4% with rAsBasicTail immunization to more than 85% by immunization with rAsKunitz and rAs8.9kDa. The mortality of nymphs fed on immunized mice reached 70-100%. Therefore, all three proteins are potential antigens with the possibility of becoming a new tool in the control of A. sculptum.

Uso de metformina no tratamento da diabetes mellitus durante a gestação: revisão bibliográfica / Use of metformin in the treatment of diabetes mellitus during pregnancy: a literature review

Introdução: A Diabetes Mellitus engloba um conjunto de distúrbios metabólicos que levam a hiperglicemia e consequente deficiência insulínica. A incidência de Diabetes Mellitus Gestacional vem aumentando em conjunto com o aumento de casos de Diabetes Mellitus, constituindo um relevante problema de saúde atual. Dentre os principais fatores de risco para Diabetes Mellitus Gestacional aparecem a idade materna ≥ 35 anos, sobrepeso/ obesidade, história familiar de Diabetes Mellitus, entre outros, que levam muitas vezes à desfechos perinatais desfavoráveis como a macrossomia fetal e hipoglicemia neonatal. Como medida de tratamento inicial indica-se a mudança de estilo de vida, evoluindo para os tratamentos farmacológicos caso haja falha de tratamento inicial. Estes incluem a insulinoterapia (o padrão-ouro de tratamento) ou hipoglicemiantes orais, notadamente a metformina. Esta última desponta recentemente como uma alternativa de tratamento. Método: Trabalho elaborado através de revisão de literatura, com pesquisa realizada nas bases de dados Pubmed, LILACS e Cochrane. Foram selecionados artigos sobre diabetes gestacional contendo resultados sobre o uso de metformina e insulina, tanto no quesito de desfecho materno como perinatal, analisando os dados concordantes, discordantes ou indiferentes. Discussão: Alguns fatores têm sido comparados com relação ao uso das medicações disponíveis (metformina x insulina), a fim de constatar quais seriam as vantagens e desvantagens de cada método e seus desfechos perinatais. Os principais fatores estudados foram o ganho de peso materno, desenvolvimento de pré-eclampsia, prematuridade, necessidade de internação em UTI neonatal, Apgar de primeiro e quinto minuto, hipoglicemia neonatal, controle da glicemia materna, efeitos colaterais das medicações, peso de nascimento do recém nascido (RN) e seguimento do RN a longo prazo. Conclusão: Apesar de a insulinoterapia ainda ser padrão ouro no tratamento de diabetes mellitus gestacional, a metformina vem se mostrando método seguro e eficaz no controle da mesma, sem grandes diferenças nos resultados maternos e perinatais a curto e longo prazo.

The role of insulin at brain-liver axis in the control of glucose production.

Glucose is an essential metabolic substrate for all mammalian cells, and its availability in the circulation is carefully controlled to avoid wide variations. Different mechanisms are involved in the glucose disposal, such as an adequate pancreatic and hepatic function. Insulin is the main hormone in glycemic control, and its action occurs directly in the cells, as well as in the liver, in an indirect way, to ultimately control the glycemia. Insulin has also an important action within the central nervous system, more precisely in the hypothalamus that projects directly to preautonomic nuclei in the brain stem to control hepatic glucose production. The central action of insulin relies on autonomic outflow through the vagal innervation of the liver, where insulin is able to modulate the production of glucose at this organ level. In this way, responses generated in the CNS reach the effector organs by autonomic efferent pathways as part of an important brain-organ axis in the control of glycemia. The purpose of this minireview is to shed light on the brain-liver axis in the control of hepatic glucose by central action of insulin via the autonomic nervous system.

Subdiaphragmatic vagus nerve activity and hepatic venous glucose are differentially regulated by the central actions of insulin in Wistar and SHR.

Glucose is the most important energy substrate for the maintenance of tissues function. The liver plays an essential role in the control of glucose production, since it is able to synthesize, store, and release glucose into the circulation under different situations. Hormones like insulin and catecholamines influence hepatic glucose production (HGP), but little is known about the role of the central actions of physiological doses of insulin in modulating HGP via the autonomic nervous system in nonanesthetized rats especially in SHR where we see a high degree of insulin resistance and metabolic dysfunction. Wistar and SHR received ICV injection of insulin (100 nU/µL) and hepatic venous glucose concentration (HVGC) was monitored for 30 min, as an indirect measure of HGP. At 10 min after insulin injection, HVGC decreased by 27% in Wistar rats, with a negligible change (3%) in SHR. Pretreatment with atropine totally blocked the reduction in HVGC, while pretreatment with propranolol and phentolamine induced a decrease of 8% in HVGC after ICV insulin injection in Wistar. Intracarotid infusion of insulin caused a significant increase in subdiaphragmatic vagus nerve (SVN) activity in Wistar (12 ± 2%), with negligible effects on the lumbar splanchnic sympathetic nerve (LSSN) activity (-6 ± 3%). No change was observed in SVN (-2 ± 2%) and LSSN activities (2 ± 3%) in SHR after ICA insulin infusion. Taken together, these results show, in nonanesthetized animals, the importance of the parasympathetic nervous system in controlling HVGC, and subdiaphragmatic nerve activity following central administration of insulin; a mechanism that is impaired in the SHR.

Protein disulfide isomerase expression increases in resistance arteries during hypertension development. Effects on Nox1 NADPH oxidase signaling.

NADPH oxidases derived reactive oxygen species (ROS) play an important role in vascular function and remodeling in hypertension through redox signaling processes. Previous studies demonstrated that protein disulfide isomerase (PDI) regulates Nox1 expression and ROS generation in cultured vascular smooth muscle cells. However, the role of PDI in conductance and resistance arteries during hypertension development remains unknown. The aim of the present study was to investigate PDI expression and NADPH oxidase dependent ROS generation during hypertension development. Mesenteric resistance arteries (MRA) and thoracic aorta were isolated from 6, 8, and 12 week-old spontaneously hypertensive (SHR) and Wistar rats. ROS production (dihydroethidium fluorescence), PDI (WB, imunofluorescence), Nox1 and NOX4 (RT-PCR) expression were evaluated. Results show a progressive increase in ROS generation in MRA and aorta from 8 to 12 week-old SHR. This effect was associated with a concomitant increase in PDI and Nox1 expression only in MRA. Therefore, suggesting a positive correlation between PDI and Nox1 expression during the development of hypertension in MRA. In order to investigate if this effect was due to an increase in arterial blood pressure, pre hypertensive SHR were treated with losartan (20 mg/kg/day for 30 days), an AT1 receptor antagonist. Losartan decreased blood pressure and ROS generation in both vascular beds. However, only in SHR MRA losartan treatment lowered PDI and Nox1 expression to control levels. In MRA PDI inhibition (bacitracin, 0.5 mM) decreased Ang II redox signaling (p-ERK 1/2). Altogether, our results suggest that PDI plays a role in triggering oxidative stress and vascular dysfunction in resistance but not in conductance arteries, increasing Nox1 expression and activity. Therefore, PDI could be a new player in oxidative stress and functional alterations in resistance arteries during the establishment of hypertension.

Regulatory phosphorylation of FXYD2 by PKC and cross interactions between FXYD2, plasmalemmal Ca-ATPase and Na,K-ATPase.

FXYD2 is a regulatory peptide associated with the α-subunit of the kidney Na,K-ATPase. FXYD2 can be phosphorylated by PKA, and its phosphorylation activates Na,K-ATPase. Here we show that FXYD2 is phosphorylated by PKC (PKC-FXYD2-P), by PKA (PKA-FXYD2-P) or by PKA and PKC simultaneously (FXYD2-P(2)) modulating both the erythrocyte Na,K-ATPase and the plasma membrane Ca(2+)-ATPase (PMCA). In erythrocyte ghosts, the addition of PKA-FXYD2-P activated Na,K-ATPase by 80%, while non-phosphorylated FXYD2 (np) activated only 55%. The addition of np FXYD2 did not affect PMCA basal activity, but FXYD2-P(2) increased the basal PMCA activity by up to 200%. Calmodulin-activated PMCA activity was increased by np FXYD2 (3-fold) or FXYD2-P(2) (2.5-fold). However, PKC-FXYD2-P increased PMCA activity only by 50%. In contrast, when PMCA was treated with PKA-FXYD2-P, the ATPase activity was inhibited by 50%. The effect of all forms of FXYD2-P on calcium uptake from PMCA resembled the pattern observed in ATP hydrolysis. Our results suggest that the FXYD2 anchoring site could be conserved among the P-ATPase family permitting cross regulation. The effects of FXYD2 on calcium uptake and calcium-stimulated ATP hydrolysis suggest a novel role for FXYD2 on PMCA.