Low-grade endotoxemia, gut permeability and platelet activation in patients with impaired fasting glucose.

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.

Cytoprotective and Antioxidant Effects of Steen Solution on Human Lung Spheroids and Human Endothelial Cells.

Respiratory diseases represent a major healthcare burden worldwide. Lung transplantation (LTx) is the "gold standard" for end-stage patients, strongly limited by shortage of available/suitable donor lungs. Normothermic ex vivo lung perfusion (EVLP) has significantly increased the number of lungs suitable for transplantation. Steen solution is used for EVLP, but the mechanisms involved in its beneficial properties remain to be clarified. We investigated the effects of Steen solution in an in vitro protocol of cold starvation and normothermic recovery on human lung spheroids, named pneumospheres (PSs), containing epithelial/basal cells, and on endothelial human umbilical vein endothelial cells (HUVEC). Steen solution significantly preserved the viability of PSs, reduced reactive oxygen species (ROS) release by PSs and HUVECs, decreased NADPH-oxidase (NOX) activity in PSs, and reduced inflammatory cytokines expression levels in HUVECs. Steen solution was able to specifically reduce NADPH oxidase 2 (NOX2) isoform activation, particularly in PSs, as detected by soluble-NOX2 peptide and p47-phosphorylation. Interestingly, a specific NOX2 inhibitor could partly mimic the pro-survival effect of Steen on PSs. We provide the first evidence that Steen solution can preserve lung epithelial/progenitor cells viability partially through NOX2 downregulation, and exert antioxidant effects on parenchymal cells, with consequent ROS reduction. These results suggest that NOX2 inhibition might be an additional strategy to reduce cellular damage during LTx procedures.

Nuclear ULK1 promotes cell death in response to oxidative stress through PARP1.

Reactive oxygen species (ROS) may cause cellular damage and oxidative stress-induced cell death. Autophagy, an evolutionarily conserved intracellular catabolic process, is executed by autophagy (ATG) proteins, including the autophagy initiation kinase Unc-51-like kinase (ULK1)/ATG1. Although autophagy has been implicated to have both cytoprotective and cytotoxic roles in the response to ROS, the role of individual ATG proteins, including ULK1, remains poorly characterized. In this study, we demonstrate that ULK1 sensitizes cells to necrotic cell death induced by hydrogen peroxide (H2O2). Moreover, we demonstrate that ULK1 localizes to the nucleus and regulates the activity of the DNA damage repair protein poly (ADP-ribose) polymerase 1 (PARP1) in a kinase-dependent manner. By enhancing PARP1 activity, ULK1 contributes to ATP depletion and death of H2O2-treated cells. Our study provides the first evidence of an autophagy-independent prodeath role for nuclear ULK1 in response to ROS-induced damage. On the basis of our data, we propose that the subcellular distribution of ULK1 has an important role in deciding whether a cell lives or dies on exposure to adverse environmental or intracellular conditions.

C2238/αANP modulates apolipoprotein E through Egr-1/miR199a in vascular smooth muscle cells in vitro.

Subjects carrying the T2238C ANP gene variant have a higher risk to suffer a stroke or myocardial infarction. The mechanisms through which T2238C/αANP exerts detrimental vascular effects need to be fully clarified. In the present work we aimed at exploring the impact of C2238/αANP (mutant form) on atherosclerosis-related pathways. As a first step, an atherosclerosis gene expression macroarray analysis was performed in vascular smooth muscle cells (VSMCs) exposed to either T2238/αANP (wild type) or C2238/αANP. The major finding was that apolipoprotein E (ApoE) gene expression was significantly downregulated by C2238/αANP and it was upregulated by T2238/αANP. We subsequently found that C2238/αANP induces ApoE downregulation through type C natriuretic peptide receptor (NPR-C)-dependent mechanisms involving the upregulation of miR199a-3p and miR199a-5p and the downregulation of DNAJA4. In fact, NPR-C knockdown rescued ApoE level. Upregulation of miR199a by NPR-C was mediated by a reactive oxygen species-dependent increase of the early growth response protein-1 (Egr-1) transcription factor. In fact, Egr-1 knockdown abolished the impact of C2238/αANP on ApoE and miR199a. Of note, downregulation of ApoE by C2238/αANP was associated with a significant increase in inflammation, apoptosis and necrosis that was completely rescued by the exogenous administration of recombinant ApoE. In conclusion, our study dissected a novel mechanism of vascular damage exerted by C2238/αANP that is mediated by ApoE downregulation. We provide the first demonstration that C2238/αANP downregulates ApoE in VSMCs through NPR-C-dependent activation of Egr-1 and the consequent upregulation of miR199a. Restoring ApoE levels could represent a potential therapeutic strategy to counteract the harmful effects of C2238/αANP.

Management of hypertension and stroke prevention: results of the Italian cardiologist survey.

OBJECTIVE: To provide an overview of current habits, priorities, perceptions and knowledge of cardiologists with regard to hypertension and stroke prevention in outpatient practice. METHODS: A sample of 203 cardiologists operating in outpatient clinics and randomly selected amongst members of the largest Italian Outpatient Cardiologist Association were interviewed by e-mail, in April-May 2007. RESULTS: The interviewed cardiologists reported that hypertensive outpatients represent a large percentage of their practice population, in which the clinical priority was blood pressure (BP) reduction. Stroke was identified as the most important event to prevent and it was also perceived as the most preventable hypertension-related cardiovascular event. A remarkably high rate of achieved BP control was reported, to a degree that it is inconsistent with current epidemiological reports and with the relatively low percentage use of combination therapies declared by cardiologists. Additional risk factors, organ damage, diabetes mellitus and atrial fibrillation were consistently reported in hypertensive patients. Among antihypertensive drug classes, a preference for angiotensin-converting enzyme inhibitors has been expressed by the majority of physicians; this choice was generally justified by evidence derived from international trials or by the antihypertensive efficacy of this drug class. CONCLUSIONS: The results confirm the presence of weaknesses in the current services for patients with hypertension, even when being managed by cardiologists. Discrepancies between perceptions and reality, or clinical practice and guideline recommendations are also highlighted. An analysis of these aspects may help to identify current areas of potential improvement for stroke prevention in the clinical management of hypertension in cardiology practice.

A protective role of a cholesteryl ester transfer protein gene variant towards ischaemic stroke in Sardinians.

OBJECTIVES: Cholesteryl ester transfer protein (CETP) plays a key role in the metabolism of high-density lipoprotein (HDL), a strong, inverse, independent risk factor for cardiovascular disease. We sought to investigate the relationship between a common variant of CETP gene, the Taq1 B polymorphism, that has been previously associated with CETP blood concentrations, and the risk of ischaemic stroke in a genetically homogenous population from the Sardinia island, Italy. This population has been previously shown to be a highly conservative sample. DESIGN: A total of 215 cases of ischaemic stroke and 236 controls were selected and characterized for the CETP Taq1 B polymorphism. Allele and genotype frequencies were compared amongst cases and controls. RESULTS: Age, hypertension and hypercholesterolaemia were independent risk factors for stroke in this cohort. We found that presence of the CETP Taq1 B2 allele was associated with a significantly decreased risk of ischaemic stroke when assuming a recessive mode of inheritance (OR 0.55, 95% CI = 0.34-0.90, P = 0.017). This result was confirmed by multivariate analysis, after adjustment for age, presence of hypertension and hypercholesterolaemia (OR 0.53, 95% CI = 0.32-0.88, P = 0.014). By performing separate analysis for gender we found that the effect was present in females but not in males, with a significant sex-CETP gene variant interaction for both recessive (P = 0.005) and additive (P = 0.029) modes of inheritance. CONCLUSIONS: Our data suggest that the Taq1 B2 allelic variant of the CETP gene may be associated, as a protective factor, with occurrence of ischaemic stroke. Further studies are needed to further elucidate the clinical implications of our finding.