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Nitric oxide (NO) represents a crucial mediator to regulate cerebral blood flow (CBF) in the human brain both under basal conditions and in response to somatosensory stimulation. An increase in intracellular Ca2+ concentrations ([Ca2+]i) stimulates the endothelial NO synthase to produce NO in human cerebrovascular endothelial cells. Therefore, targeting the endothelial ion channel machinery could represent a promising strategy to rescue endothelial NO signalling in traumatic brain injury and neurodegenerative disorders. Allyl isothiocyanate (AITC), a major active constituent of cruciferous vegetables, was found to increase CBF in non-human preclinical models, but it is still unknown whether it stimulates NO release in human brain capillary endothelial cells. In the present investigation, we showed that AITC evoked a Ca2+-dependent NO release in the human cerebrovascular endothelial cell line, hCMEC/D3. The Ca2+ response to AITC was shaped by both intra- and extracellular Ca2+ sources, although it was insensitive to the pharmacological blockade of transient receptor potential ankyrin 1, which is regarded to be among the main molecular targets of AITC. In accord, AITC failed to induce transmembrane currents or to elicit membrane hyperpolarization, although NS309, a selective opener of the small- and intermediate-conductance Ca2+-activated K+ channels, induced a significant membrane hyperpolarization. The AITC-evoked Ca2+ signal was triggered by the production of cytosolic, but not mitochondrial, reactive oxygen species (ROS), and was supported by store-operated Ca2+ entry (SOCE). Conversely, the Ca2+ response to AITC did not require Ca2+ mobilization from the endoplasmic reticulum, lysosomes or mitochondria. However, pharmacological manipulation revealed that AITC-dependent ROS generation inhibited plasma membrane Ca2+-ATPase (PMCA) activity, thereby attenuating Ca2+ removal across the plasma membrane and resulting in a sustained increase in [Ca2+]i. In accord, the AITC-evoked NO release was driven by ROS generation and required ROS-dependent inhibition of PMCA activity. These data suggest that AITC could be exploited to restore NO signalling and restore CBF in brain disorders that feature neurovascular dysfunction.

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Introduction: Endothelial cells (ECs), being located at the interface between flowing blood and vessel wall, maintain cardiovascular homeostasis by virtue of their ability to integrate chemical and physical cues through a spatio-temporally coordinated increase in their intracellular Ca2+ concentration ([Ca2+]i). Endothelial heterogeneity suggests the existence of spatially distributed functional clusters of ECs that display different patterns of intracellular Ca2+ response to extracellular inputs. Characterizing the overall Ca2+ activity of the endothelial monolayer in situ requires the meticulous analysis of hundreds of ECs. This complex analysis consists in detecting and quantifying the true Ca2+ events associated to extracellular stimulation and classifying their intracellular Ca2+ profiles (ICPs). The injury assay technique allows exploring the Ca2+-dependent molecular mechanisms involved in angiogenesis and endothelial regeneration. However, there are true Ca2+ events of nearly undetectable magnitude that are almost comparable with inherent instrumental noise. Moreover, undesirable artifacts added to the signal by mechanical injury stimulation complicate the analysis of intracellular Ca2+ activity. In general, the study of ICPs lacks uniform criteria and reliable approaches for assessing these highly heterogeneous spatial and temporal events. Methods: Herein, we present an approach to classify ICPs that consists in three stages: 1) identification of Ca2+ candidate events through thresholding of a feature termed left-prominence; 2) identification of non-true events, known as artifacts; and 3) ICP classification based upon event temporal location. Results: The performance assessment of true-events identification showed competitive sensitivity = [0.9995, 0.9831], specificity = [0.9946, 0.7818] and accuracy = [0.9978, 0.9579] improvements of 2x and 14x, respectively, compared with other methods. The ICP classifier enhanced by artifact detection showed 0.9252 average accuracy with the ground-truth sets provided for validation. Discussion: Results indicate that our approach ensures sturdiness to experimental protocol maneuvers, besides it is effective, simple, and configurable for different studies that use unidimensional time dependent signals as data. Furthermore, our approach would also be effective to analyze the ICPs generated by other cell types, other dyes, chemical stimulation or even signals recorded at higher frequency.

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Type 2 Diabetes Mellitus (T2DM) is a rapidly rising disease with cardiovascular complications constituting the most common cause of death among diabetic patients. Chronic hyperglycemia can induce vascular dysfunction through damage of the components of the vascular wall, such as vascular smooth muscle cells (VSMCs), which regulate vascular tone and contribute to vascular repair and remodeling. These functions are dependent on intracellular Ca2+ changes. The mechanisms by which T2DM affects Ca2+ handling in VSMCs still remain poorly understood. Therefore, the objective of this study was to determine whether and how T2DM affects Ca2+ homeostasis in VSMCs. We evaluated intracellular Ca2+ signaling in VSMCs from Zucker Diabetic Fatty rats using Ca2+ imaging with Fura-2/AM. Our results indicate that T2DM decreases Ca2+ release from the sarcoplasmic reticulum (SR) and increases the activity of store-operated channels (SOCs). Moreover, we were able to identify an enhancement of the activity of the main Ca2+ extrusion mechanisms (SERCA, PMCA and NCX) during the early stage of the decay of the ATP-induced Ca2+ transient. In addition, we found an increase in Ca2+ entry through the reverse mode of NCX and a decrease in SERCA and PMCA activity during the late stage of the signal decay. These effects were appreciated as a shortening of ATP-induced Ca2+ transient during the early stage of the decay, as well as an increase in the amplitude of the following plateau. Enhanced cytosolic Ca2+ activity in VSMCs could contribute to vascular dysfunction associated with T2DM.

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BACKGROUND: Patients with systemic lupus erythematosus (SLE) have an increased cardiovascular (CV) risk. Insulin resistance (IR), which is higher in patients with SLE, adversely impacts left ventricular (LV) remodeling and function. The aims were to determine LV dysfunction and evaluate the influence of potential risk factors on subclinical LV dysfunction in women with SLE, including IR. METHODS: This cross-sectional study included adult women with SLE without diabetes mellitus (DM), hypertension or severe obesity. Diastolic dysfunction (DD) was verified according to current guidelines. Insulin resistance was estimated using the Quantose score. RESULTS: We included 77 women. The frequency of IR was 65%. All participants had a normal ejection fraction (EF), and 11 (15.7%) had abnormal LV global longitudinal strain (GLS). Twenty-three (32.8%) had DD. The GLS% and global circumferential strain (GCS)% did not differ in patients with and without IR (-20.8 ± 3.1 vs -20.5 ± 2.1; p = 0.61 and -27.9 ± 4.4 vs -27.4 ± 3.7; p = 0.57, respectively). The prevalence of DD was 38.1% in patients with IR versus 25% in those without (p = 0.30). E/e' and E/A ratios did not differ between groups (6.6 ± 1.9 vs 6.6 ± 1.5; p = 0.98 and 1.3 ± 0.3 vs 1.3 ± 0.2; p = 0.27). Higher BMI (OR: 1.2, 95% CI 1.1-1.5) and disease duration (OR: 1.2, 95% CI 1.1-1.4) were associated with DD. CONCLUSIONS: Patients with overweight/obesity may be at higher risk of LV dysfunction. Although IR was high in our patients with SLE was not associated with systolic dysfunction or DD. Body mass index and disease duration were associated with an increased risk of DD.

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OBJECTIVE: Cardiovascular (CV) morbidity is a well-established problem in systemic lupus erythematosus (SLE). Antimalarial (AM) therapy has been seen as a potential atheroprotective agent. The aim was to assess the impact of AM therapy on traditional and novel atherosclerosis (AT) biomarkers in patients with SLE. METHODS: A search of MEDLINE, EMbase, and Cochrane library for studies evaluating the impact of AM on AT biomarkers in SLE was conducted. Data extraction included serum, functional and structural traditional and novel biomarkers. A narrative synthesis of the findings and a meta-analysis with random effects was conducted estimating mean differences (MD), OR, HR and 95% CIs. RESULTS: The search strategy produced 148 articles, of which 64 were extracted for analysis. The MD in VLDL-cholesterol (-10.29, 95% CI -15.35, 5.24), triglycerides (-15.68, 95% CI -27.51, -3.86), and diastolic BP (-3.42, 95% CI -5.62, -1.23) differed significantly in patients on AM therapy compared with those without AM therapy. Patients on AM had a lower prevalence and incidence of diabetes mellitus than patients not on AM (HR: 0.39, 95% CI 0.17, 0.88). HCQ use was associated with lower blood pressure (BP) variability. Structural markers like carotid intima-media thickness (IMT), carotid plaque (CP) and coronary artery calcification (CAC) were not influenced by AM. For functional markers like endothelial and arterial stiffness the benefit was unclear. The GRADE approach showed a very low-to-low quality of evidence (QoE) per outcome. CONCLUSIONS: There is some evidence on the associations between AM therapy and some AT markers. However, the data on which this conclusion was based was of low to very low evidence.

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BACKGROUND AND AIMS: Non-invasive surrogates of cardiovascular (CV) disease such as endothelial dysfunction (ED) and peripheral arterial stiffness (AS) have been evaluated in systemic lupus erythematosus (SLE) patients. The aim of this study was to systematically review and meta-analyze reports of cardiovascular disease (CVD) in SLE patients, as measured by ED and AS. METHODS: Studies analyzing the relationship of SLE with ED (flow-mediated dilatation [FMD], nitroglycerin-mediated dilatation [NMD] and peripheral arterial tonometry [PAT]) and AS (augmentation index [AIx], pulse wave velocity [PWV]) were systematically searched for in PubMed, Cochrane library, EMBASE, VHL, SciELO and Web of Science databases. Inclusion criteria included peer-review and English language. Mean differences (MD) and 95% confidence intervals (CIs) were estimated using the random effect model. The study was registered with PROSPERO, number CRD42019121068. RESULTS: The meta-analysis included 49 studies. FMD data from 18 studies including 943 SLE subjects (mean age = 38.71 [95%CI 36.21, 41.21] years) and 644 unaffected controls (mean age = 38.63 [95%CI 36.11, 41.15] years) were included. When compared with unaffected controls, FMD in SLE subjects was decreased by 4.3% (95%CI: -6.13%, -2.47%): p < 0.001). However, NMD did not significantly differ between SLE patients and controls (MD = - 2.68%; 95% CI -6.00, 0.62; p = 0.11). A significantly increased AS between SLE patients and controls according to overall PWV (MD = 1.12 m/s; 95% CI 0.72-1.52; p < 0.001) was observed, but not for the brachial-ankle PWV. AIx was also increased in SLE patients compared with healthy controls (MD = 4.55%; 95% CI 1.48-7.63; p = 0.003). CONCLUSIONS: Overall, SLE patients showed impaired FMD, an independent predictor of CV events. There was a higher degree of AS in SLE patients compared with controls. ED and AS in SLE should be considered when planning preventive strategies and therapies.

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The neuromodulator histamine is able to vasorelax in human cerebral, meningeal and temporal arteries via endothelial histamine 1 receptors (H1 Rs) which result in the downstream production of nitric oxide (NO), the most powerful vasodilator transmitter in the brain. Although endothelial Ca 2+ signals drive histamine-induced NO release throughout the peripheral circulation, the mechanism by which histamine evokes NO production in human cerebrovascular endothelial cells is still unknown. Herein, we exploited the human cerebral microvascular endothelial cell line, hCMEC/D3, to assess the role of intracellular Ca 2+ signaling in histamine-induced NO release. To achieve this goal, hCMEC/D3 cells were loaded with the Ca 2+ - and NO-sensitive dyes, Fura-2/AM and DAF-FM/AM, respectively. Histamine elicited repetitive oscillations in intracellular Ca 2+ concentration in hCMEC/D3 cells throughout a concentration range spanning from 1 pM up to 300 µM. The oscillatory Ca 2+ response was suppressed by the inhibition of H 1 Rs with pyrilamine, whereas H 1 R was abundantly expressed at the protein level. We further found that histamine-induced intracellular Ca 2+ oscillations were initiated by endogenous Ca 2+ mobilization through inositol-1,4,5-trisphosphate- and nicotinic acid dinucleotide phosphate-sensitive channels and maintained over time by store-operated Ca 2+ entry. In addition, histamine evoked robust NO release that was prevented by interfering with the accompanying intracellular Ca 2+ oscillations, thereby confirming that the endothelial NO synthase is recruited by Ca 2+ spikes also in hCMEC/D3 cells. These data provide the first evidence that histamine evokes NO production from human cerebrovascular endothelial cells through intracellular Ca 2+ oscillations, thereby shedding novel light on the mechanisms by which this neuromodulator controls cerebral blood flow.

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OBJECTIVE: A protective function of vitamin D in metabolic syndrome (MetS) has been described. The objective of the present study was to examine the relationship between serum 25-hydroxyvitamin D (25(OH)D) concentrations and MetS in non-diabetic systemic lupus erythematosus (SLE) women. METHODS: Cross-sectional analyses of the relationship between concentrations of 25(OH)D, MetS, and its components were made in 160 non-diabetic SLE women. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III criteria. Serum 25(OH)D was measured by chemiluminescent immunoassay. Serum 25(OH)D concentrations were categorized into quartiles (<16.6, 16.6-21.1, 21.2-26.3, ≥26.4 ng/mL). RESULTS: A total of 79 (49.3%) SLE women had MetS. Without adjusting for body mass index (BMI) or smoking, the odds of having MetS decreased according to increasing quartiles of 25(OH)D concentrations (P for trend = .03). The odds ratio (OR) of having MetS was 0.4 (95% confidence interval: 0.2-0.9, P = .04) for the highest vs the lowest quartile of 25(OH)D concentrations when adjusted by age. The crude OR of having elevated hypertriglyceridemia decreased according to increasing quartiles of 25(OH)D concentrations (P for trend = .036). However, further adjustments for BMI and smoking removed the inverse association between 25(OH)D concentrations and MetS and its individual components. CONCLUSION: In non-diabetic SLE women with mild activity, 25(OH)D concentrations are not associated with MetS and its components.

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