NO inhibits the hKv1.5 current by a cGMP-dependent mechanism and by the S-nitrosylation of the hKv1.5 protein, an effect that contributes to shaping the human atrial action potentials.
Our aim was to analyze the plasma proteome in aspirin (acetylsalicylic acid [ASA])-sensitive and ASA-resistant coronary ischemic patients. Plasma from 19 ASA-sensitive and 19 ASA-resistant patients was
analyzed. For the proteomic study, two-dimensional electrophoresis was performed. The expression
of one isotype of the fibrinogen γ chain and three isotypes of haptoglobin was increased in ASA-resistant patients. Three vitamin D binding protein isotypes were increased in ASA-resistant patients.
In vitro incubation of vitamin D binding protein (DBP) with blood from healthy volunteers reduced the
inhibitory effect of ASA on thromboxane A2 production. DBP may be a new regulator of the inhibitory
effect of ASA on platelets.
Keywords: Aspirin (acetylsalicylic acid [ASA]) · plasma proteome · platelets · thromboxane A2
Proteomics is a technology to detect and identify several proteins and their isoforms in a single sample. We used proteomics to analyze modifications in the protein map of plasma after simvastatin treatment of moderate hypercholesterolemic patients. Plasma from hypercholesterolemic patients (n = 9) was compared before and after 12 weeks of simvastatin treatment (40 mg/day). Patients with similar cardiovascular risk factors were used as controls (CR group). By using two-dimensional electrophoresis and mass spectrometry, we identified the different protein isoforms. The plasma expression of three fibrinogen gamma chain isoforms (FGG) was enhanced, whereas the expression of two isoforms of the fibrinogen beta chain (FGB) was reduced in the hypercholesterolemic patients compared with the CR group. The expression of apolipoprotein A-IV and three haptoglobin isoforms was higher in hypercholesterolemic patients. Simvastatin treatment modified the plasma expression of FGG chain isoform 1, FGB chain isoforms 1 and 2, vitamin D binding protein isoform 3, apo A-IV, and haptoglobin isoform 2. The modification of FGG chain isoform 1 and FGB chain isoforms 1 and 2 was positively correlated with total plasma cholesterol level. Proteomic analysis of plasma may help to know more in depth the molecular mechanism modified by simvastatin treatment.
1 Inflammation and platelet activation are critical phenomena in the setting of acute coronary syndromes. Platelets may contribute to increase ischemic injury by enhancing the inflammatory response of leukocytes and endothelial myocardial cells. Pharmacological inhibition of platelet activation prevents ischemic complications in patients with coronary diseases. Agents directed against the integrin glycoprotein IIb/IIIa (GP IIb/IIIa) receptor not only inhibit platelet aggregation but also have been demonstrated to limit the inflammatory response in acute coronary syndromes. The question then raised is if the inhibition of platelet activation by other mechanisms than the blockade of GP IIb/IIIa may also exert anti-inflammatory effects. The aim of the present study was to analyze if clopidogrel may exert anti-inflammatory effects during the acute phase of myocardial infarction. 2 A ligature was placed around the left anterior descending coronary artery of New Zealand White rabbits. After 15 min of ischemia, the myocardium was reperfused and the ischemic coronary artery was isolated 24 h after the ischemia. A group of ischemic rabbits was given a single oral dose of clopidogrel (20 mg kg À1 ) just after the arterial occlusion and the animal was recovered. Sham-operated animals served as control. 3 P-selectin expression was significantly increased in infarcted rabbits with respect to control rabbits. Clopidogrel administration reduced P-selectin expression with respect to untreated infarcted rabbits. CD40 ligand and tissue factor expression was increased in the ischemic coronary artery and reduced after clopidogrel administration. Clopidogrel also protected endothelial nitric oxide synthase protein expression in the ischemic coronary artery, a protein that has been found downregulated under inflammatory conditions. 4 In conclusion, inhibition of platelet activation by clopidogrel exerted anti-inflammatory effects on the ischemic coronary artery.
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