Hyperglycemia-induced hemichorea-hemiballismus syndrome - a systematic review.

Nonketotic hyperglycemia may occur as a cause of chorea in patients with chronic decompensated diabetes. Because it is rare and consequently poorly studied, diagnosis and treatment can be delayed. Therefore, our objective was to summarize clinical and radiological features, as well as treatments performed, from previously reported cases to facilitate adequate management in clinical practice. We searched MEDLINE/PubMed, EMBASE, Cochrane, CINAHL, Web of Science, Scopus, and LILACS databases for studies published before April 23, 2021. We included case reports and case series of adults (aged ≥ 18 years) that described hyperglycemic chorea with measurement ofglycated hemoglobin (HbA1c) and cranial magnetic resonance imaging (MRI). Studies were excluded if participants were pregnant women, aged < 18 years, and had no description of chorea and/or physical examination. We found 121 studies that met the inclusion criteria, for a total of 214 cases. The majority of the included studies were published in Asia (67.3%). Most patients were women(65.3%) aged > 65 years (67.3%). Almost all patients had decompensated diabetes upon arrival at the emergency department (97.2%). The most common MRI finding was abnormalities of the basal ganglia (89.2%). There was no difference in patient recovery between treatment with insulin alone and in combination with other medications. Although rare, hyperglycemic chorea is a reversible cause of this syndrome; therefore, hyperglycemia should always be considered in these cases.

Hyperglycemia-induced hemichorea-hemiballismus syndrome - a systematic review

ABSTRACT Nonketotic hyperglycemia may occur as a cause of chorea in patients with chronic decompensated diabetes. Because it is rare and consequently poorly studied, diagnosis and treatment can be delayed. Therefore, our objective was to summarize clinical and radiological features, as well as treatments performed, from previously reported cases to facilitate adequate management in clinical practice. We searched MEDLINE/PubMed, EMBASE, Cochrane, CINAHL, Web of Science, Scopus, and LILACS databases for studies published before April 23, 2021. We included case reports and case series of adults (aged ≥ 18 years) that described hyperglycemic chorea with measurement of glycated hemoglobin (HbA1c) and cranial magnetic resonance imaging (MRI). Studies were excluded if participants were pregnant women, aged < 18 years, and had no description of chorea and/or physical examination. We found 121 studies that met the inclusion criteria, for a total of 214 cases. The majority of the included studies were published in Asia (67.3%). Most patients were women (65.3%) aged > 65 years (67.3%). Almost all patients had decompensated diabetes upon arrival at the emergency department (97.2%). The most common MRI finding was abnormalities of the basal ganglia (89.2%). There was no difference in patient recovery between treatment with insulin alone and in combination with other medications. Although rare, hyperglycemic chorea is a reversible cause of this syndrome; therefore, hyperglycemia should always be considered in these cases.

The power of the placebo effect in diabetes: A systematic review and meta-analysis.

This review aims to identify the magnitude of the placebo effect in people with type 2 diabetes mellitus. Literature research was conducted Medline, Embase and Virtual Health Library for studies published between the date of inception and June 2021. The eligibility criteria included randomized controlled trials, showing comparison to placebo, having participants with type 2 diabetes mellitus, and having glycated hemoglobin (HbA1c) as the primary outcome. Meta-analysis was conducted with the effect of changing HbA1c in relation to the baseline. Exploration of heterogeneity was performed.The meta-analysis showed an increase in the average of HbA1c compared to the baseline of 0.14% (95% CI: 0.07-0.21). There was a significant difference between follow-up times (p = 0.03) and between administration routes (p = 0.01), with an increase in HbA1c in the oral route [0.15% (95% CI: 0.07-0.23)]. The meta-regression of the year of publication showed a significant downward trend (p = 0.01) of the increase in HbA1c compared to the baseline.In this study, the expected placebo effect of Hba1c reduction was not found; instead, higher Hba1c levels were observed in the control groups, although this effect was reduced over the years. Registration: PROSPERO ID CRD42020172797.

Bradykinin promotes murine melanoma cell migration and invasion through endogenous production of superoxide and nitric oxide.

Spatial confinement and temporal regulation of signaling by nitric oxide (NO) and reactive oxygen species (ROS) occurs in cancer cells. Signaling mediated by NO and ROS was investigated in two sub clones of the murine melanoma B16F10-Nex2 cell line, Nex10C and Nex8H treated or not with bradykinin (BK). The sub clone Nex10C, similar to primary site cells, has a low capacity for colonizing the lungs, whereas the sub clone Nex8H, similar to metastatic cells, corresponds to a highly invasive melanoma. BK-treated Nex10C cells exhibited a transient increase in NO and an inhibition in basal O2- levels. Inhibition of endogenous NO production by l-NAME resulted in detectable levels of O2-. l-NAME promoted Rac1 activation and enhanced Rac1-PI3K association. l-NAME in the absence of BK resulted in Nex10C cell migration and invasion, suggesting that NO is a negative regulator of O2- mediated cell migration and cell invasion. BK-treated Nex8H cells sustained endogenous NO production through the activation of NOS3. NO activated Rac1 and promoted Rac1-PI3K association. NO stimulated cell migration and cell invasion through a signaling axis involving Ras, Rac1 and PI3K. In conclusion, a role for O2- and NO as positive regulators of Rac1-PI3K signaling associated with cell migration and cell invasion is proposed respectively for Nex10C and Nex8H murine melanoma cells.

Healthcare of pregnant women with diabetes during the COVID-19 pandemic: a Southern Brazilian cross-sectional panel data.

OBJECTIVES: To evaluate the indirect effects of the COVID-19 pandemic on the care of women with pregnancies complicated by gestational or pre-existing diabetes, and their maternal-fetal outcomes. METHODS: A cross-sectional panel data conducted in a University Hospital in Southern Brazil. Maternal-fetal outcomes and predictors of care from 235 pregnant women with type 1, type 2, or gestational diabetes were evaluated. Two time periods were compared: six months preceding the pandemic, in 2019, and the COVID-19 period from September 2020 to March 2021. Comparisons were performed using analysis of variance, Mann-Whitney U, Fisher's exact and T-tests. Risks were calculated using the Poisson regression with robust estimates. RESULTS: Maternal age was lower (32.1 ± 6.8 vs. 34.4 ± 6.6, p=0.009) and rates of depression/anxiety were higher (16.5 vs. 7.4%, p=0.046) in the group evaluated during the COVID-19. Neonatal hypoglycemia (RR 4.04; 95% CI 1.37-11.98, p=0.012), and SGA rates (RR 4.29; 95% CI 1.93-9.54, p<0.001) were higher in the group assessed before the pandemic. CONCLUSIONS: Despite economic, social and structural impacts of the pandemic, parameters of maternal care were similar; diabetes control improved, and neonatal hypoglycemia and SGA rates were lower among pregnant women with diabetes during the pandemic.

Proteostasis Response to Protein Misfolding in Controlled Hypertension.

Hypertension is the most determinant risk factor for cardiovascular diseases. Early intervention and future therapies targeting hypertension mechanisms may improve the quality of life and clinical outcomes. Hypertension has a complex multifactorial aetiology and was recently associated with protein homeostasis (proteostasis). This work aimed to characterize proteostasis in easy-to-access plasma samples from 40 individuals, 20 with controlled hypertension and 20 age- and gender-matched normotensive individuals. Proteostasis was evaluated by quantifying the levels of protein aggregates through different techniques, including fluorescent probes, slot blot immunoassays and Fourier-transform infrared spectroscopy (FTIR). No significant between-group differences were observed in the absolute levels of various protein aggregates (Proteostat or Thioflavin T-stained aggregates; prefibrillar oligomers and fibrils) or total levels of proteostasis-related proteins (Ubiquitin and Clusterin). However, significant positive associations between Endothelin 1 and protein aggregation or proteostasis biomarkers (such as fibrils and ubiquitin) were only observed in the hypertension group. The same is true for the association between the proteins involved in quality control and protein aggregates. These results suggest that proteostasis mechanisms are actively engaged in hypertension as a coping mechanism to counteract its pathological effects in proteome stability, even when individuals are chronically medicated and presenting controlled blood pressure levels.

Benefits of water intake on kidney function in older adults: protocol for a randomized controlled trial / Benefícios da ingestão de água na função renal de idosos: protocolo para um estudo clínico randomizado controlado

Objective: The goal of this study is to evaluate the benefits of an increase in water intake guided by a mathematical formula (per kg of body weight) on kidney function in older adults. Methods: Older adults (≥ 65 years old) cared for at the Internal Medicine Unit of a tertiary hospital will be randomized to receive or not guidance on water intake (30 mL/kg per day) after initial assessment of kidney function. After 14 days, participants will be reevaluated through clinical and laboratory examinations. Patients with uncompensated disease will be excluded. The main outcomes will be glomerular filtration rate and laboratory measures such as serum and urinary osmolality, sodium, urea, 24-h urine volume and serum creatinine, uric acid, and copeptin. The Mini Nutritional Assessment (MNA) questionnaire will be applied to participants at each visit. Categorical variables will be described as numbers of cases (%) and compared using the χ2 test whereas continuous variables will be analyzed with Student's t-test in relation to baseline measures. The Generalized Estimating Equations (GEE) method will be performed to assess differences over time and between groups. This study was approved by the Institution's Research Ethics Committee (grant number 16-0153) and is in accordance with the Declaration of Helsinki. Expected Results:By increasing water intake (ml/Kg) we expect to provide an improvement in kidney function in older population assessed by serum creatinine and cystatin-c applied to eGFR formulas. Relevance:Many conditions, both organic and behavioral, can contribute to chronic dehydration states in older adults. To mention, decreased ability to concentrate urine, reduced kidney mass, blood flow, and glomerular filtration rate (GFR) along with changes in sensitivity to hormones such as renin, vasopressin and natriuretic peptide can generate water imbalance, leading to dehydration. For being simple and inexpensive, this strategy may be broadly used and bring several health benefits to older adults.

Objetivo: O objetivo deste estudo é avaliar os benefícios de um aumento da ingestão de água guiado por uma fórmula matemática (por kg de massa corporal) na função renal de idosos. Metodologia:Idosos (≥ 65 anos) atendidos pelo Serviço de Clínica Médica de um hospital terciário foram randomizados para receber ou não orientação sobre o consumo de água (30 mL/kg por dia) após uma avaliação inicial da função renal. Após 14 dias, os participantes serão reavaliados através de exames clínicos e laboratoriais. Pacientes com doença descompensada serão excluídos. Os desfechos principais são a taxa de filtração glomerular e medidas laboratoriais como osmolaridade, sódio e ureia séricos e urinários, volume de urina de 24 horas e creatinina, ácido úrico e copeptina séricos. A Mini Avaliação Nutricional (MNA) será aplicada aos participantes a cada consulta. Variáveis categóricas serão descritas como números de casos (%) e comparadas usando o teste χ2 , enquanto variáveis contínuas serão analisadas com o teste t de Student em relação às medidas iniciais. O método de Equações de Estimativas Generalizadas (GEE) será usado para avaliar diferenças ao longo do tempo e entre grupos. Este estudo foi aprovado pelo Comitê de Ética em Pesquisa da nossa Instituição (processo número 16-0153) e está de acordo com a Declaração de Helsinki. Resultados esperados:Ao aumentar a ingestão de água (ml/Kg) esperamos proporcionar uma melhora na função renal na população idosa avaliada pela creatinina sérica e cistatina-c aplicada às fórmulas de eGFR. Relevância:Muitas condições, tanto orgânicas quanto comportamentais, podem contribuir para estados de desidratação crônica em idosos. Vale mencionar que a diminuição da capacidade de concentração da urina, redução da massa renal, fluxo sanguíneo e taxa de filtração glomerular (TFG) juntamente com alterações na sensibilidade a hormônios como renina, vasopressina e peptídeo natriurético podem gerar desequilíbrio hídrico, levando à desidratação. Por ser simples e de baixo custo, essa estratégia pode ser amplamente utilizada e trazer diversos benefícios à saúde dos idosos.

Impact of the COVID-19 pandemic on mental health of pregnant women with diabetes mellitus and hypertension.

OBJECTIVE: Psychological effects of the coronavirus disease 2019 (COVID-19) pandemic on pregnant women with diabetes and hypertension are not yet studied. Besides the pregnancy, these women have additional risk factors for severe acute respiratory syndrome due to COVID-19 and are considered a particularly vulnerable, unique population. We aimed to assess their mental health during this pandemic. METHODS: This is a cross-sectional study carried out at a Brazilian tertiary hospital. Women with pregnancies complicated by hypertension and/or diabetes were evaluated. The primary outcome was anxiety, and depressive symptoms evaluated with the State-Trait Anxiety Inventory and Patient Health Questionnaire. Perception of changing habits during quarantine was evaluated as a secondary outcome. RESULTS: Seventy-nine patients were included. The prevalence of State-Trait Anxiety Inventory ≥40 was 79.7% and that of Patient Health Questionnaire ≥10 was 59.2%. Lower social support was correlated with higher scores on both scales. Time spent with electronic devices was perceived as greater by 62% of the women. CONCLUSIONS: Pregnant women with diabetes and hypertension presented high levels of anxiety and depressive symptoms during the COVID-19 pandemic. Considering that these symptoms can affect both the mother's and offspring's health, it is necessary to implement tools to improve their mental health.

Impact of the COVID-19 pandemic on mental health of pregnant women with diabetes mellitus and hypertension

SUMMARY OBJECTIVE: Psychological effects of the coronavirus disease 2019 (COVID-19) pandemic on pregnant women with diabetes and hypertension are not yet studied. Besides the pregnancy, these women have additional risk factors for severe acute respiratory syndrome due to COVID-19 and are considered a particularly vulnerable, unique population. We aimed to assess their mental health during this pandemic. METHODS: This is a cross-sectional study carried out at a Brazilian tertiary hospital. Women with pregnancies complicated by hypertension and/or diabetes were evaluated. The primary outcome was anxiety, and depressive symptoms evaluated with the State-Trait Anxiety Inventory and Patient Health Questionnaire. Perception of changing habits during quarantine was evaluated as a secondary outcome. RESULTS: Seventy-nine patients were included. The prevalence of State-Trait Anxiety Inventory ≥40 was 79.7% and that of Patient Health Questionnaire ≥10 was 59.2%. Lower social support was correlated with higher scores on both scales. Time spent with electronic devices was perceived as greater by 62% of the women. CONCLUSIONS: Pregnant women with diabetes and hypertension presented high levels of anxiety and depressive symptoms during the COVID-19 pandemic. Considering that these symptoms can affect both the mother's and offspring's health, it is necessary to implement tools to improve their mental health.

Choosing statins: a review to guide clinical practice.

Statins are among the most widely prescribed medicines in the world and have proved their value in reducing cardiovascular events and mortality. Many patients report adverse effects that lead to interruption of treatment. This review aims to individualize statin treatment, considering efficacy for reducing cardiovascular risk and safety, in the setting of specific diseases, to minimize the side effects and improve compliance. We gathered evidence that may help clinicians to choose specific statins in different clinical situations, such as the risk of new diabetes, chronic kidney disease, liver disease, human immunodeficiency virus infection, organ transplant, heart failure and elderly people. Efficacy of statins is well established in a large number of clinical conditions. Therefore, main objective is to revise statin in specific clinical settings, based on pharmacokinetics, safety, drug metabolism and interactions to provide the best choice in different clinical scenarios.

Choosing statins: a review to guide clinical practice

ABSTRACT Statins are among the most widely prescribed medicines in the world and have proved their value in reducing cardiovascular events and mortality. Many patients report adverse effects that lead to interruption of treatment. This review aims to individualize statin treatment, considering efficacy for reducing cardiovascular risk and safety, in the setting of specific diseases, to minimize the side effects and improve compliance. We gathered evidence that may help clinicians to choose specific statins in different clinical situations, such as the risk of new diabetes, chronic kidney disease, liver disease, human immunodeficiency virus infection, organ transplant, heart failure and elderly people. Efficacy of statins is well established in a large number of clinical conditions. Therefore, main objective is to revise statin in specific clinical settings, based on pharmacokinetics, safety, drug metabolism and interactions to provide the best choice in different clinical scenarios.

Patient-centered Management of Type 2 Diabetes Mellitus Based on Specific Clinical Scenarios: Systematic Review, Meta-analysis and Trial Sequential Analysis.

INTRODUCTION: New antihyperglycemic medications have been proven to have cardiovascular (CV) and renal benefits in type 2 diabetes mellitus (T2DM); however, an evidence-based decision tree in specific clinical scenarios is lacking. MATERIALS AND METHODS: Systematic review and meta-analysis of randomized controlled trials (RCTs), with trial sequential analysis (TSA). Randomized controlled trial inclusion criteria were patients with T2DM from 1 of these subgroups: elderly, obese, previous atherosclerotic CV disease (ASCVD), previous coronary heart disease (CHD), previous heart failure (HF), or previous chronic kidney disease (CKD). Randomized controlled trials describing those subgroups with at least 48 weeks of follow-up were included. Outcomes: 3-point major adverse cardiovascular events (MACE), CV death, hospitalization due to HF, and renal outcomes. We performed direct meta-analysis with the number of events in the intervention and control groups in each subset, and the relative risk of the events was calculated. RESULTS: Sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1 RA) were the only antihyperglycemic agents related to a reduction in CV events in different populations. For obese and elderly populations, GLP-1 RA were associated with benefits in 3-point MACE; for patients with ASCVD, both SGLT2i and GLP-1 RA had benefits in 3-point MACE, while for patients with CHD, only SGLT2i were beneficial. CONCLUSIONS: SGLT2i and GLP-1 RA reduced CV events in selected populations: SGLT2i led to a reduction in events in patients with previous CHD, ASCVD, and HF. GLP-1 RA led to a reduction in CV events in patients with ASCVD, elderly patients, and patients with obesity. Trial sequential analysis shows that these findings are conclusive. This review opens a pathway towards evidence-based, personalized treatment of T2DM. REGISTRATION: PROSPERO CRD42019132807.

Reunion overseas: introduced wild boars and cultivated orange trees interact in the Brazilian Atlantic Forest

Introduction: Little is known concerning novel interactions between species that typically interact in their native range but, as a consequence of human activity, are also interacting out of their original distribution under new ecological conditions. Objective: We investigate the interaction between the orange tree and wild boar, both of which share Asian origins and have been introduced to the Americas (i.e. the overseas). Methods: Specifically, we assessed whether i) wild boars consume orange (Citrus sinensis) fruits and seeds in orchards adjacent to a remnant of the Atlantic Forest of Brazil, ii) the orange seeds are viable after passing through boar's digestive tract and iii) whether the orange tree may naturalise in the forest remnant assisted by wild boars. Results: Our camera surveys indicated that wild boar was by far the most frequent consumer of orange fruits (40.5 % of camera trap-days). A considerable proportion of sown orange seeds extracted from fresh boar feces emerged seedlings (27.8 %, N = 386) under controlled greenhouse conditions. Further, 37.6 % of sown seeds (N = 500) in the forest remnant emerged seedlings in July 2015; however, after ~4 years (March 2019) only 9 seedlings survived (i.e. 4.8 %, N = 188). Finally, 52 sweet orange seedlings were found during surveys within the forest remnant which is intensively used by wild boars. This study indicates a high potential of boars to act as effective seed dispersers of the sweet orange. However, harsh competition with native vegetation and the incidence of lethal diseases, which quickly kill sweet orange trees under non-agricultural conditions, could seriously limit orange tree establishment in the forest. Conclusions: Our results have important implications not only because the wild boar could be a vector of potential invasive species, but also because they disperse seeds of some native species (e.g. the queen palm, Syagrus romanzofiana) in defaunated forests, where large native seed dispersers are missing; thus, wild boars could exert critical ecological functions lost due to human activity.

Introducción: Se conoce relativamente poco sobre las llamadas 'interacciones noveles' entre especies que típicamente interactúan en su área de distribución nativa pero que, como consecuencia de la actividad humana, también interactúan fuera de su distribución original bajo nuevas condiciones ecológicas. Objetivo: Investigamos la interacción entre el naranjo y el jabalí, ambos con origen asiático e introducidos en las Américas (es decir, del extranjero). Métodos: Específicamente, evaluamos si i) los jabalíes consumen frutas y semillas del naranjo (Citrus sinensis) en naranjales adyacentes a un parche remanente del bosque atlántico de Brasil, ii) las semillas de naranja son viables tras pasar por el tracto digestivo del jabalí, y iii) si el naranjo puede llegar a naturalizarse en el parche de bosque gracias a los jabalíes. Resultados: Los resultados de nuestro fototrampeo indicaron que el jabalí fue, con mucho, el consumidor más frecuente de las naranjas (40.5 % cámaras trampa-días). Una proporción considerable de semillas de naranjo extraídas de heces de jabalí frescas y sembradas emergieron plántulas bajo condiciones de invernadero controladas (27.8 %, N = 386). Además, del 37.6 % de las semillas sembradas (N = 500) en el parche remanente de bosque emergieron plántulas en julio 2015; sin embargo, después de ~ 4 años (marzo 2019) solo sobrevivieron 9 plántulas (es decir, 4.8 %, N = 188). Finalmente, se encontraron 52 plántulas de naranja dulce durante varias prospecciones dentro del parche de bosque que es utilizado intensivamente por los jabalíes. Este estudio indica un alto potencial de los jabalíes para actuar como dispersores de semillas eficaces del naranjo dulce. Sin embargo, la severa competencia con la abundante vegetación nativa y la incidencia de enfermedades letales, que matan rápidamente los naranjos dulces en condiciones no agrícolas, podrían limitar seriamente el establecimiento de naranjos en el bosque. Conclusiones: Nuestros resultados tienen implicaciones importantes no solo porque el jabalí podría ser un vector de posibles especies de plantas invasoras, sino también porque dispersan semillas de algunas especies nativas (p.e., la palmera reina, Syagrus romanzofiana) en estos bosques defaunados, donde faltan dispersores nativos de semillas de gran tamaño. Por ello, los jabalíes podrían ejercer funciones ecológicas críticas que se han perdido debido a la actividad humana.

Childhood trauma and dimensions of depression: a specific association with the cognitive domain

Objective: To investigate associations between a history of childhood trauma and dimensions of depression in a sample of clinically depressed patients. Methods: A sample of 217 patients from a mood-disorder outpatient unit was investigated with the Beck Depression Inventory, the Hamilton Depression Rating Scale, the CORE Assessment of Psychomotor Change, and the Childhood Trauma Questionnaire. A previous latent model identifying six depressive dimensions was used for analysis. Path analysis and Multiple Indicators Multiple Causes (MIMIC) models were used to investigate associations between general childhood trauma and childhood maltreatment modalities (emotional, sexual, and physical abuse; emotional and physical neglect) with dimensions of depression (sexual, cognition, insomnia, appetite, non-interactiveness/retardation, and agitation). Results: The overall childhood trauma index was uniquely associated with cognitive aspects of depression, but not with any other depressive dimension. An investigation of childhood maltreatment modalities revealed that emotional abuse was consistently associated with depression severity in the cognitive dimension. Conclusion: Childhood trauma, and specifically emotional abuse, could be significant risk factors for the subsequent development of cognitive symptoms of major depression. These influences might be specific to this depressive dimension and not found in any other dimension, which might have conceptual and therapeutic implications for clinicians and researchers alike.

Childhood trauma and dimensions of depression: a specific association with the cognitive domain.

OBJECTIVE: To investigate associations between a history of childhood trauma and dimensions of depression in a sample of clinically depressed patients. METHODS: A sample of 217 patients from a mood-disorder outpatient unit was investigated with the Beck Depression Inventory, the Hamilton Depression Rating Scale, the CORE Assessment of Psychomotor Change, and the Childhood Trauma Questionnaire. A previous latent model identifying six depressive dimensions was used for analysis. Path analysis and Multiple Indicators Multiple Causes (MIMIC) models were used to investigate associations between general childhood trauma and childhood maltreatment modalities (emotional, sexual, and physical abuse; emotional and physical neglect) with dimensions of depression (sexual, cognition, insomnia, appetite, non-interactiveness/retardation, and agitation). RESULTS: The overall childhood trauma index was uniquely associated with cognitive aspects of depression, but not with any other depressive dimension. An investigation of childhood maltreatment modalities revealed that emotional abuse was consistently associated with depression severity in the cognitive dimension. CONCLUSION: Childhood trauma, and specifically emotional abuse, could be significant risk factors for the subsequent development of cognitive symptoms of major depression. These influences might be specific to this depressive dimension and not found in any other dimension, which might have conceptual and therapeutic implications for clinicians and researchers alike.

Ras, Rac1, and phosphatidylinositol-3-kinase (PI3K) signaling in nitric oxide induced endothelial cell migration.

The small GTP-binding proteins Ras and Rac1 are molecular switches exchanging GDP for GTP and converting external signals in response to a variety of stimuli. Ras and Rac1 play an important role in cell proliferation, cell differentiation, and cell migration. Rac1 is directly involved in the reorganization and changes in the cytoskeleton during cell motility. Nitric oxide (NO) stimulates the Ras - ERK1/2 MAP kinases signaling pathway and is involved in the interaction between Ras and the phosphatidyl-inositol-3 Kinase (PI3K) signaling pathway and cell migration. This study utilizes bradykinin (BK), which promotes endogenous production of NO, in an investigation of the role of NO in the activation of Rac1 in rabbit aortic endothelial cells (RAEC). NO-derived from BK stimulation of RAEC and incubation of the cells with the s-nitrosothiol S-nitrosoglutathione (GSNO) activated Rac1. NO-derived from BK stimulation promoted RAEC migration over a period of 12 h. The use of RAEC permanently transfected with the dominant negative mutant of Ras (Ras(N17)) or with the non-nitrosatable mutant of Ras (Ras(C118S)); and the use of specific inhibitors of: Ras, PI3K, and Rac1 resulted in inhibition of NO-mediated Rac1 activation. BK-stimulated s-nitrosylation of Ras in RAEC mediates Rac1 activation and cell migration. Inhibition of NO-mediated Rac1 activation resulted in inhibition of endothelial cell migration. In conclusion, the NO indirect activation of Rac1 involves the direct participation of Ras and PI3K in the migration of endothelial cells stimulated with BK.

Endothelium-derived nitric oxide (NO) activates the NO-epidermal growth factor receptor-mediated signaling pathway in bradykinin-stimulated angiogenesis.

Nitric oxide (NO) is involved in angiogenesis and stimulates the EGF-R signaling pathway. Stimulation of different endothelial cell lines with bradykinin (BK) activates the endothelial NO synthase (eNOS) and promotes EGF-R tyrosine phosphorylation. Increase in NO production correlated with enhanced phosphorylation of tyrosine residues and S-nitrosylation of the EGF-R. NO-mediated stimulatory effects on tyrosine phosphorylation of the EGF-R, where cGMP independent. Inhibition of soluble guanylyl cyclase followed by BK stimulation of human umbilical vein endothelial cells (HUVECs) did not change tyrosine phosphorylation levels of EGF-R. BK-stimulation of HUVEC promoted S-nitrosylation of the phosphatase SHP-1 and of p21Ras. Phosphorylation and activation of the ERK1/2 MAP kinases mediated by BK was dependent on the activation of the B2 receptor, of the EGF-R, and of p21 Ras. Inhibition of BK-stimulated S-nitrosylation prevented the activation of the ERK1/2 MAP kinases. Furthermore, activated ERK1/2 MAP kinases inhibited internalization of EGF-R by phosphorylating specific Thr residues of its cytoplasmic domain. BK-induced proliferation of endothelial cells was partially inhibited by the NOS inhibitor (L-NAME) and by the MEK inhibitor (PD98059). BK stimulated the expression of vascular endothelial growth factor (VEGF). VEGF expression was dependent on the activation of the EGF-R, the B2 receptor, p21Ras, and on NO generation. A Matrigel®-based in vitro assay for angiogenesis showed that BK induced the formation of capillary-like structures in HUVEC, but not in those cells expressing a mutant of the EGF-R lacking tyrosine kinase activity. Additionally, pre-treatment of BK-stimulated HUVEC with L-NAME, PD98059, and with SU5416, a specific inhibitor of VEGFR resulted in inhibition of in vitro angiogenesis. Our findings indicate that BK-mediated angiogenesis in endothelial cells involves the induction of the expression of VEGF associated with the activation of the NO/EGF-R/p21Ras/ERK1/2 MAP kinases signaling pathway.

Protein tyrosine phosphatase alpha regulates cell detachment and cell death profiles induced by nitric oxide donors in the A431 human carcinoma cell line.

We investigated the role of protein tyrosine phosphatase-alpha (PTPα) expression in the cell death profile of the A431 human carcinoma cell line that was induced by cytotoxic concentrations of the nitric oxide (NO) donors sodium nitroprusside (SNP) and 3,3-bis-(aminoethyl)-1-hydroxy-2-oxo-1-triazene (NOC-18). Both NO donors promoted extensive cell detachment in A431 parental cells as compared to the detachment observed for A431 cells that ectopically expressed PTPα (A431 (A27B(PTPα)) cells). The NO-induced cell death characteristics for both cell lines were examined. After incubation for 10 hours with 2.0 mM SNP, attached or detached A431 cells underwent apoptosis. Cells were highly positive for Annexin-V, featured increased cleavage of procaspase-8, activation of downstream caspase-3, and activation of poly-ADP-ribose polymerase 1 (PARP-1). In contrast, exposure of A431 (A27B(PTPα)) cells to 2.0 mM SNP produced an increase in the release of lactate dehydrogenase and enhanced incorporation of propidium iodide. In addition, A431 (A27B(PTPα)) cells showed partial inhibition of the activities of caspase-8, caspase-3, and PARP-1 upon detachment and cell death induced by SNP treatment. Results indicate that necrotic cell damage was induced, characterized by cellular swelling and lysis. We conclude from these results that PTPα regulates the A431 tumor cell death profile mediated by NO donors. Expression of PTPα or its absence may determine the occurrence of NO-induced cell death with necrotic or apoptotic features, respectively.

Regulatory effects of nitric oxide on Src kinase, FAK, p130Cas, and receptor protein tyrosine phosphatase alpha (PTP-alpha): a role for the cellular redox environment.

The role of NO in regulating the focal adhesion proteins, Src, FAK, p130 Cas, and PTP-alpha, was investigated. Fibroblasts expressing PTP-alpha (PTP-alpha(WT) cells), fibroblasts "knockout" for PTP-alpha (PTP-alpha(-/-) cells), and "rescued" "knockout" fibroblasts (PTP-alpha A5/3 cells) were stimulated with either S-nitroso-N-acetylpenicillamine (SNAP) or fetal bovine serum (FBS). FBS increased inducible NO synthase in both cell lines. Activation of Src mediated either by SNAP or by FBS occurred independent of dephosphorylation of Tyr527 in PTP-alpha(-/-) cells. Both stimuli promoted dephosphorylation of Tyr527 and activation of Src kinase in PTP-alpha(WT) cells. NO-mediated activation of Src kinase affected the activities of FAK and p130Cas and was dependent on the expression of PTP-alpha. Analogous to tyrosine phosphorylation, SNAP and FBS stimulated differential generation of NO and S-nitrosylation of Src kinase in both cell lines. Incubation with SNAP resulted in higher levels of NO and S-nitrosylation of immunoprecipitated Src in PTP-alpha(-/-) cells (oxidizing redox environment) as compared with the levels of NO and S-nitrosylated Src in PTP-alpha(WT) cells (reducing redox environment). SNAP differentially stimulated cell proliferation of both cell lines is dependent on the intracellular redox environment, Src activity, and PTP-alpha expression. This dependence also is observed with FBS-stimulated cell migration.