[Show abstract][Hide abstract] ABSTRACT: Qtracker(®)800 Vascular labels (Qtracker(®)800) are promising biomedical tools for high-resolution vasculature imaging; their effects on mouse and human endothelia, however, are still unknown.
Qtracker(®)800 were injected in Balb/c mice, and brain endothelium uptake was investigated by transmission electron microscopy 3-h post injection. We then investigated, in vitro, the effects of Qtracker(®)800 exposure on mouse and human endothelial cells by calcium imaging.
Transmission electron microscopy images showed nanoparticle accumulation in mouse brain endothelia. A subset of mouse and human endothelial cells generated intracellular calcium transients in response to Qtracker(®)800.
Qtracker(®)800 nanoparticles elicit endothelial functional responses, which prompts biomedical safety evaluations and may bias the interpretation of experimental studies involving vascular imaging.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the effects of supervised exercise training (SET) on cardiometabolic risk, cardiorespiratory fitness and oxidative stress status in 2 diabetes mellitus (T2DM), twenty male subjects with T2DM were randomly assigned to an intervention group, which performed SET in a hospital-based setting, and to a control group. SET consisted of a 12-month supervised aerobic, resistance and flexibility training. A reference group of ten healthy male subjects was also recruited for baseline evaluation only. Participants underwent medical examination, biochemical analyses and cardiopulmonary exercise testing. Oxidative stress markers (1-palmitoyl-2-[5-oxovaleroyl]-sn-glycero-3-phosphorylcholine [POVPC]; 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphorylcholine [PGPC]) were measured in plasma and in peripheral blood mononuclear cells. All investigations were carried out at baseline and after 12 months. SET yielded a significant modification (p < 0.05) in the following parameters: V'O2max (+14.4%), gas exchange threshold (+23.4%), waist circumference (-1.4%), total cholesterol (-14.6%), LDL cholesterol (-20.2%), fasting insulinemia (-48.5%), HOMA-IR (-52.5%), plasma POVPC (-27.9%) and PGPC (-31.6%). After 12 months, the control group presented a V'O2max and a gas exchange threshold significantly lower than the intervention group. Plasma POVC and PGPC were significantly different from healthy subjects before the intervention, but not after. In conclusion, SET was effective in improving cardiorespiratory fitness, cardiometabolic risk and oxidative stress status in T2DM.
[Show abstract][Hide abstract] ABSTRACT: Although the understanding the pathophysiology of atherogenesis and atherosclerosis progression has been one of the major goals of cardiovascular research during the last decades, the precise mechanisms underlying plaque destabilization are still unknown. The disruption of the plaque and the thrombosis in the lumen that are mostly determined by the expansion of the necrotic core (NC) are driven by various mechanisms, including accelerated macrophage apoptosis and defective phagocytic clearance (defective efferocytosis). Oxidative stress is implicated in the expansion of the NC: in fact, many oxidized compounds and processes contribute to the macrophage apoptosis; in addition, the oxidized derivatives of polyunsatured fatty acids promote defective efferocytosis, with the final result of NC expansion. In the last years the role of the endoplasmic reticulum (ER) stress is under investigation to better define its possible contribution in affecting the NC expansion. The abnormal amount of apoptotic cells in the vulnerable plaque has been demonstrated to be related both to the sustained ER stress and to the expression of survival and protective genes, such as the unfolded protein response or/and the nuclear erythroid- related factor 2. In this review the authors focus on the promising results of the oxidative and ER stress in contributing to the triggering and orchestrating the atherosclerotic plaque vulnerability.
Current Medicinal Chemistry 03/2015; 22(13). DOI:10.2174/0929867322666150311150829 · 3.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ABSTRACT Endoplasmic reticulum (ER) stress plays a role in the pathogenesis of type 2 diabetes mellitus (T2DM), with activation of the unfolded protein response (UPR) and ER- apoptosis in β cells. The study aim is investigating the role of the prolonged glycaemic, inflammatory and oxidative impairment as possible UPR and ER-apoptosis inductors in triggering the ER stress response and the protective Nrf2/ARE activation in peripheral blood mononuclear cells (PBMC) of T2DM patients without glycaemic target. Oxidative stress markers (oxidation product of phospholipid 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine, oxPAPC, and malondialdehyde, MDA), the UPR and ER apoptosis, the activation of the pro-inflammatory nuclear factor (NF)-kB with its inhibitory protein IkBα and the expression of the protective Nrf2 and heme -oxygenase-1 (HO-1) were evaluated in PBMC of 15 T2DM patients and 15 healthy controls (C). OxPAPC concentrations (in PBMC and plasma), MDA levels (in plasma), the expressions of the glucose-regulated protein 78 kDa (GRP78/BiP) as representative of UPR, and of the C/EBP homologous protein (CHOP) as representative of ER-apoptosis, were significantly higher (p<0.01) in T2DM respect to C. IkBα expression was significantly lower (p<0.01) in T2DM as well as Nrf2 and HO-1. In vitro experiments demonstrated that hyperglycaemic conditions, if prolonged, were NF-kB inductors, without a corresponding Nrf2/ARE response. In PBMC of T2DM without glycaemic target achievement there is activation of the UPR and of the ER apoptosis, that may be related to the chronic exposure to hyperglycaemia, to the augmented inflammation and to the augmented oxidative stress, without a corresponding Nrf2/ARE defence activation.
Free Radical Research 12/2014; 49(3):1-23. DOI:10.3109/10715762.2014.997229 · 2.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The importance of focused cardiac ultrasound (FCU) in Internal Medicine care has been recognized by the American Society of Echocardiography. The aim of this study was to test what realistic skill targets could be achieved in FCU, with a relatively short training (theoretical and practical) of 9 h offered to Internal Medicine certification board attending students, and if the addition of further 9 h of training could significantly improve the level of competence. Kappa statistic was used to calculate the inter-observer agreement (trainees/tutor). The agreement between the trainees (who completed the entire training) and the tutor was, respectively, “substantial” (k = 0.71) for the identification of pericardial effusion, “moderate” (k = 0.56–0.54) for the identification of marked right ventricular and left ventricular enlargement, “substantial” (k = 0.77) for the assessment of global cardiac systolic function by visual inspection and “fair” (k = 0.35) for the assessment of size and respiratory change in the diameter of the inferior cave vein (IVC). 18 h training in FCU provided proficiency in obtaining adequate images from the parasternal window without providing the ability to correctly master the apical and subcostal windows. As concerns the interpretative skills, only pericardial effusion and visual estimation of global systolic function could be correctly identified, while ventricular enlargement and IVC prove to be more difficult to evaluate. This study supports incorporating FCU into Internal Medicine fellowship training programs, and should facilitate the design of other similar training courses.
Internal and Emergency Medicine 12/2014; 10(1). DOI:10.1007/s11739-014-1167-3 · 2.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Eight obese female patients were studied over a period of 15 days whilst on 300 kcal diet. Serum levels of thyroxine and free throxine index were not altered significantly by semistarvation. A TRH test performed before and after the diet showed no appreciable change. Weight loss was intially rapid but later slowed despite good patients compliance. Serum concentrations of T 3 and reverse T 3 (rT3) early decreased (p less than 0.01) and increased (p less than 0.05) respectively, but returned towards control levels even before discontinuation of semistarvation. There was a positive correlation between the percentage decrease in body weight and the percentage increase in serum rT 3 (p less than 0.001), and a negative correlation between decrease in body weight and decrease in serum T 3 (p less than 0.001). Our results do not suggest that the variations in serum triiodothyronines limit the weight loss; it is probable, on the contrary, that the weight loss promotes the observed variations in thyroid hormones by as yet unknown adaptive metabolic forces.
[Show abstract][Hide abstract] ABSTRACT: Macrophage apoptosis is involved in atherosclerotic plaque development. The aim of this study was to evaluate the interrelationship between macrophage apoptosis and the endoplasmic reticulum (ER)-stress in the tissue around the necrotic core (TANC) and in the periphery (P) of the same carotid plaques derived from patients undergoing carotid endarterectomy. Apoptosis was significantly higher in TANC than in P (p<0.001). mRNA and protein expression of protein kinase-like ER kinase (Perk), and of the nuclear erythroid related factor 2 (Nrf2)-related survival genes were significantly higher in P than in TANC (p<0.01), while CCAAT/-enhancer binding protein homologous protein (Chop) and the apoptosis-related genes were higher in TANC than in P (p<0.01). TANC extract was characterized by significantly higher concentrations of oxidized derivatives of polyunsaturated fatty acids (PUFAs) than P extract (p<0.01). When THP-1 cells were incubated with P or TANC extracts there was a dose-dependent increase of Perk and Nrf2 or of Chop and of the apoptosis-related genes respectively (p<0.01). Our observations lead to the hypothesis that ER-stress induced by oxidized derivatives of PUFAs may promote macrophage apoptosis in TANC and favour the expansion of the necrotic core of the plaques, a major feature responsible for its disruption and acute luminal thrombosis.
[Show abstract][Hide abstract] ABSTRACT: In vitro 3T3-L1 mouse cells represent a reliable model to investigate the inflammatory phenotype of adipocytes activated by bacteria-derived lipopolysaccharide (LPS). In this study we have evaluated the differential expression of adipokines in response to increasing doses of LPS and various incubation times.
3T3-L1 mouse adipocytes were treated with E. coli LPS (from 0 to 10 μg/ml) for a time course ranging from 4 to 24 h, 4 h each. A time point at 2 h was also included to highlight early activation by LPS. mRNA expression by RT-PCR on cell lysates and ELISA assays on cell culture supernatants were performed.
Cells activated by increasing doses of LPS upregulated TNF-α expression in the first 2 h, but this expression slowed down within 6-8 h, while IL-6 expression was increasing. This reduction was also observed for CXCL12/SDF1α. Unlike IL-10, IL-6 expression was constantly upregulated by prolonging incubation with LPS. TNF-α and CXCL12 gene expression occurred early in the time-course and exhibited a second increase following the first 4-6 h of incubation with LPS. Optimal expression of most adipokines needed 6-8 h of a prolonged treatment with LPS at 37 °C. The chemokines MIP-1α/CCL3 and MIP-1β/CCL4 were maximally expressed within the first 8 h, then significantly reduced in the following times. IL-10 expression was upregulated by low doses of LPS and downregulated by prolonging time with the bacterial endotoxin. ELISA analysis of released products generally confirmed the result from gene expression experiments.
These data, while assessing previously reported results, highlighted new evidence about the time-dependency in LPS-mediated adipokine production, thus contributing to the comprehension of the inflammatory response of adipocyte.
Agents and Actions 02/2014; 63(6). DOI:10.1007/s00011-014-0721-9 · 2.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Endoplasmic reticulum (ER) stress is involved in the pathophysiology of atherosclerosis. Insults interfering with endoplasmic reticulum (ER) function, lead to accumulation of unfolded and misfolded proteins in ER that initiates the unfolded protein response (UPR). When the UPR fails to control the level of unfolded and misfolded proteins, ER-initiated apoptotic signaling is induced. We evaluated: 1) the UPR and ER-initiated apoptotic signaling in peripheral blood mononuclear cells (PBMC) of stable coronary artery disease patients (CAD); 2) PBMC content of oxidation products of phospholipid 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (oxPAPC); 3) the possible origin of oxPAPC in PBMC; 4) the expression of nuclear erytroid-related factor 2 (Nrf2)/antioxidant related element (ARE), a cellular defence mechanism. 29 CAD and 28 matched controls were enrolled. Expression of glucose-regulated protein 78kDa (GRP78/BiP) as representative of UPR, and of C/EBP homologous protein (CHOP) as representative of ER-apoptosis, were significantly higher in CAD than in controls (p<0.01). Concentrations of oxPAPC in PBMC, in plasma and in low density lipoprotein (LDL) resulted significantly higher in CAD than in controls (p<0.01). The oxPAPC in PBMC may derive from circulating ox-LDL. Nrf2/ARE gene expression and circulating and cellular glutathione (GSH) were significantly lower in CAD than in controls (p<0.01). In in vitro studies, increasing amounts of oxPAPC induced a dose-dependent increase of CHOP and apoptosis-related protein expression (p<0.01) and a progressive decrease of Nrf2/ARE gene expression (p<0.01). In PBMC of CAD patients there is an activation of UPR and of ER-initiated apoptotic signaling, possibly related to abnormal concentration of oxPAPC in PBMC.
Free Radical Biology and Medicine 12/2013; 68. DOI:10.1016/j.freeradbiomed.2013.12.017 · 5.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although cigarette smoking has been associated with carotid intima-media thickness (CIMT) the mechanisms are yet not completely known. Lysophosphatidylcholine (lysoPC), a main product of lipoprotein-associated phospholipase A2 (Lp-PLA2) activity, appears to be a major determinant of the pro-atherogenic properties of oxidized LDL (oxLDL) and to induce proteoglycan synthesis, a main player in intimal thickening. In this study we assessed whether cigarette smoking-induced oxidative stress may influence plasma Lp-PLA2 and lysoPC and Lp-PLA2 expression in peripheral blood mononuclear cells (PBMC), as well as the relationship between lysoPC and CIMT.
45 healthy smokers and 45 age and sex-matched subjects participated in this study. Smokers, compared to non-smokers, showed increased plasma concentrations of oxLDL, Lp-PLA2 and lysoPC together with up-regulation of Lp-PLA2 (mRNA and protein) expression in PBMC (P<0.001). Plasma Lp-PLA2 positively correlated with both lysoPC (r=0.639, P<0.001) and PBMC mRNA Lp-PLA2 (r=0.484, P<0.001) in all subjects. Moreover CIMT that was higher in smokers (P<0.001), positively correlated with lysoPC (r=0.55, P<0.001). Then in in vitro study we demonstrated that both oxLDL (at concentrations similar to those found in smoker's serum) and oxidized phospholipids contained in oxLDL, were able to up-regulate mRNA Lp-PLA2 in PBMC. This effect was likely due, at least in part, to the enrichment in oxidized phospholipids found in PBMC after exposure to oxLDL. Our results also showed that in human aortic smooth muscle cells lysoPC, at concentrations similar to those found in smokers, increased the expression of biglycan and versican, two main proteoglycans.
In smokers a further effect of raised oxidative stress is the up-regulation of Lp-PLA2 expression in PBMC with subsequent increase of plasma Lp-PLA2 and lysoPC. Moreover the correlation between lysoPC and CIMT together with the finding that lysoPC up-regulates proteoglycan synthesis suggests that lysoPC may be a link between smoking and intimal thickening.
PLoS ONE 12/2013; 8(12):e83092. DOI:10.1371/journal.pone.0083092 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: This study evaluated the incremental value and cost-effectiveness ratio of introducing coronary angiography (CA) with multidetector computed tomography (MDCT-CA) in the diagnostic management of patients with suspected coronary artery disease (CAD) compared with the traditional diagnostic workup. MATERIAL AND METHODS: Five hundred and fifty consecutive patients who underwent MDCT-CA between January 2009 and June 2011 were considered. Patients with atypical chest pain and suspected obstructive CAD were directed to one of two diagnostic pathways: the traditional protocol (examination, stress test, CA) and the current protocol (examination, stress test, MDCT-CA, and CA, if necessary). The costs of each protocol and for the individual method were calculated. Based on the results, the cost-effectiveness ratio of the two diagnostic pathways was compared. A third, modified, diagnostic pathway has been proposed with its relative cost-effectiveness ratio (examination, MDCT-CA, stress test, and CA, if necessary). RESULTS: Stress test vs. MDCT-CA had an accuracy of 66%, a sensitivity and specificity of 21% and 87%, respectively, and a positive (PPV) and negative (NPV) predictive value of 40% and 70%, respectively. Comparison between conventional CA (CCA) and MDCT-CA showed a sensitivity and specificity of 92% and 89%, respectively, a PPV and NPV of 89%, and an accuracy of 92%. The traditional protocol has higher costs than the second protocol: 1,645 euro against 322 euro (mean), but it shows a better cost-effectiveness ratio. The new proposed protocol has lower costs, mean 261 euro, with a better costeffectiveness ratio than the traditional protocol. CONCLUSIONS: The diagnostic protocol for patients with suspected CAD has been modified by the introduction of MDCT-CA. Our study confirms the greater diagnostic performance of MDCT-CA compared with stress test and its similar accuracy to CCA. The use of MDCT-CA to select patients for CCA has a favourable cost-effectiveness profile.
La radiologia medica 05/2013; 118(8). DOI:10.1007/s11547-013-0933-z · 1.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In recent years, evidence has emerged indicating that insulin resistance and diabetes mellitus type 2 are associated with inflammation of adipose tissue (AT). Interest has been focused on epicardial AT (EAT) because of its possible involvement with atherosclerosis and cardiovascular diseases. The aim of this study was to characterize adipocyte size and inflammatory profile in subcutaneous (SAT) and EAT among subjects with or without diabetes. Biopsies were collected from SAT and EAT in 34 men undergoing elective cardiac surgery. Weight, height, body mass index, waist circumference, as well as serum levels of glucose, insulin, lipids, adiponectin, and leptin were determined in all subjects. Adiponectin, MCP-1, and CD68 mRNA levels present within cells from AT biopsies were determined by real-time polymerase chain reaction. Adipocyte size was determined by optic microscopy and morphometry. Regarding the experimental group as a whole, gene-expression levels within EAT were significantly lower for adiponectin and higher, albeit not significantly, for MCP-1, when compared with that of SAT. In addition, adipocytes in EAT were significantly smaller than those in SAT. Subjects with diabetes showed lower adiponectin gene-expression levels in both SAT and EAT when compared with subjects without diabetes. By contrast, MCP-1 and CD68 gene-expression levels were higher in both tissue types of diabetic subjects. Adipocyte size in EAT was significantly larger in diabetic subjects than in nondiabetic subjects. Our data revealed a predominantly inflammatory profile in both SAT and EAT in subjects with diabetes in comparison with those without diabetes.
Heart and Vessels 01/2013; DOI:10.1007/s00380-012-0315-9 · 2.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although oxidative stress plays a major role in endothelial dysfunction (ED), the role of glutathione (GSH), of nuclear erythroid-related factor 2 (Nrf2) and of related antioxidant genes (ARE) are yet unknown. In this study we combined an in vivo with an in vitro model to assess whether cigarette smoking affects flow-mediated vasodilation (FMD), GSH concentrations and the Nrf2/ARE pathway in human umbilical vein endothelial cells (HUVECs).
52 healthy subjects (26 non-smokers and 26 heavy smokers) were enrolled in this study. In smokers we demonstrated increased oxidative stress, i.e., reduced concentrations of GSH and increased concentrations of oxidation products of the phospholipid 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (oxPAPC) in serum and in peripheral blood mononuclear cells (PBMC), used as in vivo surrogates of endothelial cells. Moreover we showed impairment of FMD in smokers and a positive correlation with the concentration of GSH in PBMC of all subjects. In HUVECs exposed to smokers' serum but not to non-smokers' serum we found that oxidative stress increased, whereas nitric oxide and GSH concentrations decreased; interestingly the expression of Nrf2, of heme oxygenase-1 (HO-1) and of glutamate-cysteine ligase catalytic (GCLC) subunit, the rate-limiting step of synthesis of GSH, was decreased. To test the hypothesis that the increased oxidative stress in smokers may have a causal role in the repression of Nrf2/ARE pathway, we exposed HUVECs to increasing concentrations of oxPAPC and found that at the highest concentration (similar to that found in smokers' serum) the expression of Nrf2/ARE pathway was reduced. The knockdown of Nrf2 was associated to a significant reduction of HO-1 and GCLC expression induced by oxPAPC in ECs.
In young smokers with ED a novel further consequence of increased oxidative stress is a repression of Nrf2/ARE pathway leading to GSH depletion.
PLoS ONE 01/2012; 7(1):e30291. DOI:10.1371/journal.pone.0030291 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cigarette smoking is an important risk factor for atherosclerosis, a chronic inflammatory disease. However the underlying factors of this effect are unclear. It has been hypothesized that water-soluble components of cigarette smoke can directly promote oxidative stress in vasculature and blood cells. Aim of this study was to study the relationship between oxidative stress and inflammation in a group of young smokers. To do this we evaluated: 1) the oxidation products of phospholipids (oxPAPC) in peripheral blood mononuclear cells (PBMC); 2) their role in causing PBMC reactive oxygen species (ROS) generation and changes in GSH; 3) the expression of the transcription factor NF-E2-related factor 2 (Nrf2) and of related antioxidant genes (ARE); 4) the activation of NF-kB and C-reactive protein (CRP) values. We studied 90 healthy volunteers: 32 non-smokers, 32 moderate smokers (5-10 cigarettes/day) and 26 heavy smokers (25-40 cigarettes/day). OxPAPC and p47phox expression, that reasonably reflects NADPH oxidase activity, were higher in moderate smokers and heavy smokers than in non-smokers (p<0.01), the highest values being in heavy smokers (p<0.01). In in vitro studies oxPAPC increased ROS generation via NADPH oxidase activation. GSH in PBMC and plasma was lower in moderate smokers and heavy smokers than in non-smokers (p<0.01), the lowest values being in heavy smokers (p<0.01). Nrf2 expression in PBMC was higher in moderate smokers than in non-smokers (p<0.01), but not in heavy smokers, who had the highest levels of NF-kB and CRP (p<0.01). In in vitro studies oxPAPC dose-dependently increased NF-kB activation, whereas at the highest concentrations Nrf2 expression was repressed. The small interference (si) RNA-mediated knockdown of NF-kappaB/p65 increased about three times the expression of Nrf2 stimulated with oxPAPC. Cigarette smoke promotes oxPAPC formation and oxidative stress in PBMC. This may cause the activation of NF-kB that in turn may participate in the negative regulation of Nrf2/ARE pathway favouring inflammation.
PLoS ONE 12/2009; 4(12):e8225. DOI:10.1371/journal.pone.0008225 · 3.23 Impact Factor