Plasma level of sRAGE is down-regulated in chronic hyperglycemia; among its ligands, S100A12 protein, but not CML, appears to be associated with this effect.

A high intake of the omega-3 fatty acid docosahexaenoate [docosahexaenoic acid (DHA)] has been associated with systemic antiinflammatory effects and cardiovascular protection. Cyclooxygenase (COX)-2 is responsible for the overproduction of prostaglandins (PG) at inflammatory sites, and its expression is increased in atheroma. We studied the effects of DHA on COX-2 expression and activity in human saphenous vein endothelial cells challenged with proinflammatory stimuli. A ≥24-h exposure to DHA reduced COX-2 expression and activity induced by IL-1, without affecting COX-1 expression. DHA effect depended on the NF-κB-binding site in the COX-2 promoter. EMSAs confirmed that DHA attenuated NF-κB activation. Because MAPK, PKC, and NAD(P)H oxidase all participate in IL-1-mediated COX-2 expression, we also tested whether these enzymes were involved in DHA effects. Western blots showed that DHA blocked nuclear p65 NF-κB subunit translocation by decreasing cytokine-stimulated reactive oxygen species and ERK1/2 activation by effects on both NAD(P)H oxidase and PKCε activities. Finally, to address the question whether DHA itself or DHA-derived products were responsible for these effects, we inhibited the most important enzymes involved in polyunsaturated fatty acid metabolism, showing that 15-lipoxygenase-1 products mediate part of DHA effects. These studies provide a mechanistic basis for antiinflammatory and possibly plaque-stabilizing effects of DHA

Objective-The interaction of advanced glycation end products (AGEs) with their main receptor RAGE in endothelial cells induces intracellular generation of reactive oxygen species (ROS) and the expression of vascular cell adhesion molecule (VCAM)-1. We investigated the role of distinct sources of ROS, including the mitochondrial electron transport chain, NAD(P)H oxidase, xanthine oxidase, and arachidonic acid metabolism, in AGE-induced VCAM-1 expression. Methods and Results-The induction of ROS and VCAM-1 by AGEs in cultured human umbilical vein endothelial cells was specifically blocked by an anti-RAGE antibody. The inhibition of NAD(P)H oxidase by apocynin and diphenylene iodonium, and of the mitochondrial electron transport system at complex II by thenoyltrifluoroacetone (TTFA), significantly inhibited both AGE-induced ROS production and VCAM-1 expression, whereas these effects were potentiated by rotenone and antimycin A, specific inhibitors of mitochondrial complex I and III, respectively. The inhibition of Cu/Zn superoxide dismutase inhibited both ROS and VCAM-1 induction, indicating that H 2 O 2 by this source is involved as a mediator of VCAM-1 expression by AGEs. Conclusions-Altogether, these results demonstrate that ROS generated by both NAD(P)H-oxidase and the mitochondrial electron transport system are involved in AGE signaling through RAGE, and indicate potential targets for the inhibition of the atherogenic signals triggered by AGE-RAGE interaction. Key Words: diabetes mellitus Ⅲ endothelium Ⅲ reactive oxygen species Ⅲ signal transduction Ⅲ superoxide Ⅲ vascular biology Ⅲ VCAM-1 Ⅲ adhesion molecules T he formation and accumulation of advanced glycation end products (AGEs) induce vascular cellular activation and inflammation mainly through interaction of AGEs with specific receptors. The main pathological consequence of AGE interaction with the main endothelial surface receptor for AGEs (RAGE) is the induction of intracellular reactive oxygen species (ROS). 1 ROS would in turn activate the redox-sensitive transcription nuclear factor NF-B, a pleiotropic regulator of many "response-to-injury" genes, such as vascular cell adhesion molecule-1 (VCAM-1). 2,3 Several reports have linked ROS with p21ras, MAP kinases, cdc42/rac, and extracellular signal regulated kinase (ERK)-1 and -2 in the signal transduction from RAGE to NF-B-induced inflammatory molecules. 1,4 -8 Each of these pathways is closely linked to AGE binding to RAGE, because blockade of the receptor with either anti-RAGE IgG or excess soluble (s)RAGE prevents their activation. 9 The tethering of AGEs to the cell surface by RAGE is not enough to generate ROS and cellular activation, because the RAGE carboxy-terminal cytosolic tail, containing known signaling phosphorylation sites, kinase domains, and other activation sites, is critical for RAGE-dependent cellular activation. In fact, a truncated form of RAGE, lacking only the cytosolic tail and expressed in cells, retains the binding to various ligands identically as wildtype RAGE, but does n...

To elucidate the bleeding tendency that follows the administration of ticlopidine, we investigated the skin bleeding time and some ex vivo functions of platelets obtained from eight healthy volunteers before and 1 wk after daily administration of 500 mg of ticlopidine. We found the following: ticlopidine significantly (P < 0.001) prolonged the skin bleeding time and impaired the binding of radiolabeled fibrinogen and von Willebrand Factor, the clot retraction and the aggregation of platelets in response to ADP, epinephrine, thrombin, ionophore A23187, collagen, or arachidonic acid. In contrast, the administration of this drug did not affect intraplatelet levels of cAMP, agglutination and binding of von Willebrand Factor in response to ristocetin, shape change in response to ADP, collagen, thrombin, or arachidonic acid, or binding of prostaglandin El to resting platelets. Secretion of ATP in response to ADP or epinephrine was completely inhibited, whereas secretion as well as thromboxane synthesis in response to high concentrations of collagen, arachidonic acid, calcium ionophore A23187, or thrombin was unaffected. Studies with monoclonal antibodies showed that the glycoprotein IIb-IIIa complex (the putative receptor for fibrinogen and von Willebrand Factor on the surface of platelets exposed to naturally occurring aggregating agents) was quantitatively unaffected by ticlopidine. This observation was further confirmed by densitometric scannings of Periodic Acid-Schiff-stained gels of platelet suspensions. The onset, as well as the cessation of the inhibitory effect of ticlopidine on platelets was very slow, and reached a maximum after a 3-5-d administration. In addition, ticlopidine appeared to be a much more potent inhibitor when administered to subjects than when added in vitro to platelets. Finally, abnormalities comparable to those found in volunteers taking ticlopidine were observed when platelets from untreated subjects were incubated in the plasma of ticlopidine-treated subjects.We conclude that ticlopidine induces a thrombasthenic state in normal platelets without affecting the glycoprotein IlbIIIa complex quantitatively. Furthermore, our data suggest that one or more active metabolites rather than the native drug Portions of this work were presented at a symposium ("Ticlopidine: Quo vadis?") in Montpellier, France, 1983, and were published in abstract form in the proceedings of that symposium.Address reprint requests to Dr. Di Minno.

A Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) has become a pandemic disease named Coronavirus Disease-19 (COVID-19) of epochal dimension. The clinical spectrum of COVID-19 is wide, ranging from asymptomatic forms to severe pneumonia, sepsis and multiple organ dysfunction syndromes resulting in poor outcomes. Among the various consequences of severe COVID-19, cardiovascular (CV) collapse appears the most serious and potentially lethal. On the other hand, pre-existent CV comorbidities are also associated with higher mortality. The most reliable hypothetical pathogenetic mechanism for CV complications and cardiac injury in severe COVID-19 patients appears to be a sustained endothelial dysfunction, caused by the interplay of inflammation and coagulation. In this review, we survey papers addressing issues related to severe COVID-19, characterized by enhanced lung microvascular loss, hypercytokinemia, hypoxemia and thrombosis. We discuss about how the virus-induced downregulation of the angiotensin converting enzyme-2 (ACE2) receptor, used to enter the host cell, could affect the renin-angiotensin system, attempting to clarify the doubts about the use of ACE inhibitors and Angiotensin-II receptor blockers in COVID-19 patients. Finally, we point out how the delicate and physiological homeostatic function of the endothelium, which turns into a disastrous battlefield of the complex interaction between “cytokine and coagulative storms”, can be irreparably compromised and result in systemic inflammatory complications.

Current evidence suggests that most significant risk factors for heart disease have been identified. Although age, sex, and genetics are important unmodifiable risk factors, most new cases of acute myocardial infarctions today can be predicted by the presence and level of 9 risk (or cardioprotective) factors that can easily be assessed and, most importantly, modified. These risk factors are the same in almost every geographic region and in every racial/ethnic group worldwide and are consistent in men and women. Eight of these 9 risk factors are influenced by diet, and most act by promoting atherogenesis, which is the most important background condition for cardiovascular disease. Dietary interventions mostly affect atherogenesis by modulating, at the cellular level, proinflammatory processes that initiate and perpetuate endothelial dysfunction, plaque formation, and, eventually, plaque rupture. For example, there is now enough evidence, both epidemiologic and clinical, of the beneficial effects of n-3 fatty acids. Either as part of a normal low-fat diet or as supplements, these fatty acids are now recommended to prevent cardiovascular disease. This review will summarize the mechanisms by which diet may influence atherogenesis through the early inception, progression, and clinical emergence of atherosclerosis, with a special focus on n-3 fatty acids.

Age-related cognitive impairment and dementia are an increasing societal burden. Epidemiological studies indicate that lifestyle factors, e.g. physical, cognitive and social activities, correlate with reduced dementia risk; moreover, positive effects on cognition of physical/cognitive training have been found in cognitively unimpaired elders. Less is known about effectiveness and action mechanisms of physical/cognitive training in elders already suffering from Mild Cognitive Impairment (MCI), a population at high risk for dementia. We assessed in 113 MCI subjects aged 65–89 years, the efficacy of combined physical-cognitive training on cognitive decline, Gray Matter (GM) volume loss and Cerebral Blood Flow (CBF) in hippocampus and parahippocampal areas, and on brain-blood-oxygenation-level-dependent (BOLD) activity elicited by a cognitive task, measured by ADAS-Cog scale, Magnetic Resonance Imaging (MRI), Arterial Spin Labeling (ASL) and fMRI, respectively, before and after 7 months of training vs. usual life. Cognitive status significantly decreased in MCI-no training and significantly increased in MCI-training subjects; training increased parahippocampal CBF, but no effect on GM volume loss was evident; BOLD activity increase, indicative of neural efficiency decline, was found only in MCI-no training subjects. These results show that a non pharmacological, multicomponent intervention improves cognitive status and indicators of brain health in MCI subjects.

No abstract