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Atrial natriuretic peptide (ANP), a cardiac hormone involved in the regulation of water/sodium balance and blood pressure, is also secreted by endothelial cells, where it exerts protective effects in response to stress. Autophagy is an intracellular self-renewal process involved in the degradation of dysfunctional cytoplasmic elements. ANP was recently reported to act as an extracellular regulator of cardiac autophagy. However, its role in the regulation of endothelial autophagy has never been investigated. Here, we tested the effects of ANP in the regulation of autophagy in human umbilical vein endothelial cells (HUVECs). We found that ANP rapidly increases autophagy and autophagic flux at physiological concentrations through its predominant pathway, mediated by natriuretic peptide receptor type A (NPR-A) and protein kinase G (PKG). We further observed that ANP is rapidly secreted by HUVEC under stress conditions, where it mediates stress-induced autophagy through autocrine and paracrine mechanisms. Finally, we found that the protective effects of ANP in response to high-salt loading or tumor necrosis factor (TNF)-α are blunted by concomitant inhibition of autophagy. Overall, our results suggest that ANP acts as an endogenous autophagy activator in endothelial cells. The autophagy mechanism mediates the protective endothelial effects exerted by ANP., Competing Interests: Declaration of competing interest None to disclose., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Albumin has antiplatelet and anticoagulant functions. Hypoalbuminemia, as defined by serum values of <3.5 g/dL, is associated with arterial thrombosis; its impact on venous thromboembolism (VTE) is unclear., Objectives: The objective of this meta-analysis is to assess the VTE risk in patients with hypoalbuminemia., Methods: MEDLINE and EMBASE were searched up to January 2024 for observational studies and randomized trials reporting data of interest. Primary outcome was the risk of VTE, while secondary outcomes were myocardial infarction and stroke risk in patients with hypoalbuminemia versus those without hypoalbuminemia. The risk of bias was evaluated using Newcastle-Ottawa scale and Cochrane tool. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated in a random-effects model., Results: Forty-three studies for a total of 2 531 091 patients (39 738 medical and 2 491 353 surgical) were included in primary analysis; 79.1% of the studies used 3.5 g/dL cut-off value for hypoalbuminemia definition. Follow-up duration was 30 days in 60.5% of studies. Patients with hypoalbuminemia had a higher risk of VTE (RR, 1.88; 95% CI, 1.66-2.13). RRs were similar in both medical (RR, 1.87; 95% CI, 1.53-2.27) and surgical patients (RR, 1.87; 95% CI, 1.61-2.16) and in patients with (RR, 1.86; 95% CI, 1.66-2.10) and without cancer (RR, 1.89; 95% CI, 1.47-2.44). Risk of myocardial infarction (RR, 1.88; 95% CI, 1.54-2.31) and stroke (RR, 1.77; 95% CI, 1.26-2.48) was higher in patients with hypoalbuminemia., Conclusion: Hypoalbuminemia is a risk factor for VTE in both medical and surgical patients irrespective of cancer coexistence. Serum albumin analysis may represent a simple and cheap tool to identify patients at VTE risk., Competing Interests: Declaration of competing interests There are no competing interests to disclose., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Liver cirrhosis (LC) is associated with portal venous thrombosis (PVT) in roughly 20% of cirrhotic patients but the underlying mechanism is still unclear. Low-grade endotoxemia by lipopolysaccharides (LPS), a component of outer gut microbiota membrane, is detectable in the portal circulation of LC and could predispose to PVT. LPS may translocate into systemic circulation upon microbiota dysbiosis-induced gut barrier dysfunction, that is a prerequisite for enhanced gut permeability and ensuing endotoxemia. Experimental and clinical studies provided evidence that LPS behaves a pro-thrombotic molecule so promoting clotting and platelet activation. Experiments conducted in the portal circulation of cirrhotic patients showed the existence of LPS-related enhanced thrombin generation as well as endothelial dysfunction, venous stasis, and platelet activation. The review will analyze 1) the pro-thrombotic role of endotoxemia in the context of LC 2) the biological plausibility linking endotoxemia with PVT and 3) the potentially interventional tools to lower endotoxemia and eventually hypercoagulation., (Copyright © 2022. Published by Elsevier Ltd.)

Background & Aims: Oleuropein, a component of extra virgin olive oil (EVOO), reduces post-prandial glycemia with a mechanism counteracting oxidative stress-mediated incretin down-regulation. In this study we evaluated if the intake of an oleuropein-enriched chocolate could have positive effects on glycaemia and insulin levels in patients with type 2 diabetes mellitus (T2DM) and healthy subjects (HS)., Methods: Twenty-five consecutive T2DM patients and 20 HS were recruited. Participants were randomized to receive 40 g oleuropein-enriched chocolate by EVOO or 40 g control chocolate spread in a cross-over design. Serum glucose, insulin, glucagon-like peptide-1 (GLP1), and dipeptidyl-peptidase-4 (DPP4) were measured before and 2 h after chocolate intake., Results: In T2DM, the pairwise comparisons showed that intake of oleuropein-enriched chocolate was associated with a significantly less increase of blood glucose compared to control; GLM analysis showed a significant difference for treatments with respect to glucose (p = 0.04), GLP1 (p < 0.001) and DPP-4 activity (p = 0.01). In HS, the pairwise comparisons showed that, after oleuropein-enriched chocolate intake, blood glucose concentration and DPP4 activity did not change; conversely a significant increase was observed for insulin and GLP1. After control chocolate intake, a significant increase for blood glucose, insulin levels and DPP4 activity were observed while GLP1 did not change., Conclusion: The study shows that using EVOO as source of oleuropein administration of 40 g oleuropein-enriched chocolate is associated with a modest increase or no change of glycemia in T2DM and HS respectively, via an incretin-mediated mechanism., (Copyright © 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Background: Offspring of patients with early myocardial infarction have a higher risk to develop cardiovascular events; the underlying physiopathology is still unclear. Several lines of evidence support a role for oxidative stress in atherogenesis and NADPH oxidase-2 (NOX-2) is considered a major source of O2 - in human. Furthermore, oxidative stress regulates arachidonic acid metabolism via activation of platelet phospholipase-A2. The aim of this study was to address NOX-2 activity as well as serum thromboxane B2 (TXB2) and 8-isoPGF2-alpha in offspring of patients with premature myocardial infarction., Methods: Ninety-two consecutive subjects, including 46 offspring of patients with premature myocardial infarction and 46 healthy subjects (HS) matched for age and gender, were recruited. A cross sectional study was performed to compare serum activity of soluble NOX-2-dp (sNOX-2-dp), blood levels of isoprostanes and serum TXB2 in these two groups., Results: Compared with HS, offspring of patients with early myocardial infarction had higher values of serum TxB2, isoprostanes and sNOX-2-dp. Bivariate analysis in the overall population showed that serum sNOX-2-dp levels were significantly associated with serum isoprostanes and TXB2. A multiple linear regression analysis was performed to define the independent predictors of sNOX-2-dp. Serum isoprostanes (SE: 0.07; standardized coefficient β: 0.579; P < 0.001) and TXB2 levels (SE: 0.06; standardized coefficient β: 0.211; P < 0.001) were significantly associated to sNOX-2-dp (R2: 0.42)., Conclusion: This study shows that Nox-2 activation is a key determinant of oxidative stress and platelet activation in offspring of patients with premature myocardial infarction., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background and Aims: Lipopolysaccharides (LPS) is emerging as a novel risk factor for cardiovascular events (CVEs). Furthermore, in vitro evidence suggested that LPS may elicit proprotein convertase subtilisin/kexin 9 (PCSK9) expression, but their relationship in vivo has not been investigated., Methods: We conducted a post-hoc analysis of a prospective, single centre cohort study of 907 patients with non-valvular atrial fibrillation (AF). At baseline, PCSK9, LPS and NADPH oxidase (sNox2-dp) were measured. PCSK9 and LPS were correlated with the incidence of CVEs., Results: Median PCSK9 and LPS were 1200 [900-1970] and 49.9 [15.0-108.2] pg/ml, respectively. LPS and PCSK9 were significantly correlated (rS 0.378, p < 0.001). Logistic regression analysis showed that LPS was associated with PCSK9 above the median (odds ratio [OR] 1.727 95% confidence interval [CI] 1.147-2.600 p = 0.009). Other factors associated with PCSK9 above the median were sNox2-dp (OR 1.759 C.I. 95% 1.167-2.650, p = 0.007), use of antiplatelet drugs (OR 0.437 95%CI 0.219-0.871 p = 0.017) and high adherence to Mediterranean diet (OR 0.737 95%CI 0.643-0.845 p = 0.001). Olive oil (OR 0.376 95%CI 0.185-0.763, p = 0.001) and wine (OR 0.460 95%CI 0.289-0.733 p = 0.007) were negatively associated with PCSK9. Patients with concomitant high PCSK9 and LPS (LPS ≥88 pg/ml and PCSK9 ≥1570 pg/ml) had an increased risk of CVEs compared to those with low levels (LPS <24.3 pg/ml and PCSK9 <1000 pg/ml, Log-Rank test, p = 0.022)., Conclusions: This study demonstrated, for the first time in vivo, that circulating levels of PCSK9 and LPS are associated with a mechanism possibly involving NADPH oxidase activation. Patients with concomitant increase of PCSK9 and LPS showed a higher risk of CVEs., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background and Aims: Antioxidant status has been shown to be associated with cardiovascular events (CVEs). The aim of the study was to develop an assay measuring serum hydrogen peroxide (H 2 O 2 ) break-down activity (HBA) of healthy subjects (HS) and to validate it in a cohort of patients with atrial fibrillation (AF)., Methods: We developed the HBA assay in 121 HS and validated it in 842 AF patients. The occurrence of CVEs was registered and correlated with HBA in AF during a median follow-up of 30.6 months (3226 patient-years). A combined endpoint of CVEs included fatal/non-fatal ischemic stroke and myocardial infarction, cardiovascular death and transient ischemic attack., Results: In HS, median HBA was 61.2% [IQR: 52.9-69.4]. AF patients disclosed lower HBA than 30 HS balanced for age and sex (48.6% [IQR: 24.7-65.1] vs. 59.4% [IQR: 49.2-66.2], p < 0.001). During a mean follow-up of 30.6 months (3226 patient-years), 168 CVEs occurred (5.2%/year). A multivariable Cox's proportional hazards regression analysis showed that age group 3 (71-80 years, HR:5.419, p = 0.020), age group 4 (>80 years, HR:9.783, p = 0.002), diabetes (HR:1.464, p = 0.049), previous cardiac events (HR:1.887, p = 0.001) and HBA (below median, HR:2.313, p < 0.001) predicted CVEs., Conclusions: We developed an easy assay to measure serum HBA, which was associated with CVEs in AF patients. This assay may represent an additional useful tool for cardiovascular risk stratification and should be validated in other high-risk populations., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Previous reports suggest that community-acquired pneumonia (CAP) is associated with an enhanced risk of myocardial infarction (MI) and that enhanced platelet activation may play a role. Aims of this study were to investigate if urinary excretion of 11-dehydro-thromboxane (Tx) B 2 , a reliable marker of platelet activation in vivo, was elevated in CAP and whether glucocorticoid administration reduced platelet activation. Three-hundred patients hospitalized for CAP were recruited and followed-up until discharge. Within the first 2 days from admission, urinary 11-dehydro-TxB 2 and serum levels of methylprednisolone and betamethasone were measured. 11-Dehydro-TxB 2 was also measured in a control group of 150 outpatients, matched for age, sex, and comorbidities. Finally, in-vitro studies were performed to assess if glucocorticoids affected platelet activation, at the same range of concentration found in the peripheral circulation of CAP patients treated with glucocorticoids. Compared to controls, CAP patients showed significantly higher levels of 11-dehydro-TxB 2 (110 [69-151] vs. 163 [130-225] pg/mg creatinine; p < 0.001). During the in-hospital stay, 31 patients experienced MI (10%). A COX regression analysis showed that 11-dehydro-TxB 2 independently predicted MI (p = .005). CAP patients treated with glucocorticoids showed significantly lower levels of 11-dehydro-TxB 2 compared to untreated ones (147 [120-201] vs. 176 [143-250] pg/mg creatinine; p < 0.001). In vitro, glucocorticoids-treated platelets showed a dose-dependent decrease of ADP-induced platelet aggregation, TxB 2 production, cPLA 2 phosphorylation and arachidonic acid release from the platelet membrane. In conclusion, platelet TxB 2 is overproduced in CAP patients and may be implicated in MI occurrence. Glucocorticoids reduce platelet release of TxB 2 in vitro and urinary excretion of 11-dehydro-TxB 2 in vivo and may be a novel tool to decrease platelet activation in this setting., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background & Aims: Patients with cirrhosis display enhanced blood levels of factor VIII, which may result in harmful activation of the clotting system; however, the underlying mechanism is unknown., Methods: We performed a cross-sectional study in patients with cirrhosis (n=61) and matched controls (n=61) comparing blood levels of factor VIII, von Willebrand factor (vWf), lipopolysaccharide (LPS) and positivity for Escherichia coli DNA. Furthermore, we performed an in vitro study to investigate if LPS, in a concentration range similar to that found in the peripheral circulation of cirrhotic patients, was able to elicit factor VIII secretion from human umbilical vein endothelial cells (HUVEC)., Results: Patients with cirrhosis displayed higher serum levels of LPS (55.8 [42.2-79.9] vs. 23.0 [7.0-34.0]pg/ml, p<0.001), factor VIII (172.0 [130.0-278.0] vs. 39.0 [26.0-47.0]U/dl, p<0.0001), vWf (265.0 [185.0-366.0] vs. 57.0 [48.0-65.0]U/dl, p<0.001) and positivity for Escherichia coli DNA (88% vs. 3%, p<0.001, n=34) compared to controls. Serum LPS correlated significantly with factor VIII (r=0.80, p<0.001) and vWf (r=0.63, p<0.001). Only LPS (beta-coefficient=0.70, p<0.0001) independently predicted factor VIII levels. The in vitro study showed that LPS provoked factor VIII and vWf release from HUVEC via formation and secretion of Weibel-Palade bodies, a phenomenon blunted by pre-treating HUVEC with an inhibitor of Toll-like receptor 4., Conclusions: The study provides the first evidence that LPS derived from gut microbiota increases the systemic levels of factor VIII via stimulating its release by endothelial cells. Lay summary: Cirrhosis is associated with thrombosis in portal and systemic circulation. Enhanced levels of factor VIII have been suggested to play a role but the underlying mechanism is still unclear. Here we show that patients with cirrhosis display a concomitant increase of factor VIII and lipopolysaccharide (LPS) from Escherichia coli and suggest that LPS contributes to the release of factor VIII from endothelial cells., (Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background and Aim: Impaired fasting glucose (IFG) is associated with an increased risk of cardiovascular disease but the underlying mechanisms are still unclear. Aim of the study was to investigate the interplay between platelet activation, lipopolysaccharides (LPS) and markers of oxidative stress in patients with IFG and control subjects., Methods and Results: We performed a cross-sectional study including 35 patients with IFG and 35 control subjects who were well comparable for age, sex, body mass index and smoking history. Serum levels of LPS, zonulin (a marker of gut permeability), oxidized LDL and plasma levels of soluble P-selectin, were measured. Patients with IFG had significantly higher levels of sP-selectin, LPS, zonulin and oxLDL compared to control subjects. The IFG status (beta coefficient: 0.518, p < 0.001), higher LPS (beta coefficient: 0.352, p = 0.001) and female sex (beta coefficient: 0.179, p = 0.042) were independently associated with higher sP-selectin; in addition, oxLDL was positively associated with sP-selectin (r = 0.530, p < 0.001) and LPS (r = 0.529, p = 0.001). In IFG patients, we found a significant association between LPS and zonulin (r = 0.521, p = 0.001); this association was confirmed at multivariable analysis (beta coefficient: 0.512, p = 0.007)., Conclusion: Our study provides evidence that patients with IFG have increased platelet activation, and suggests LPS as a potential trigger for in vivo platelet activation in this patient population., (Copyright © 2017. Published by Elsevier B.V.)