What regulates the activity of the platelet integrin?
NLRP3 regulates platelet integrin αIIbβ3 outside-in signaling by decreasing thrombin-induced phosphorylation of Src/Syk/PLCγ2 .
What is the role of integrins in platelet aggregation?
Heterodimeric receptors of the beta1 and beta3 integrin families mediate platelet adhesion and aggregation in hemostasis and thrombosis. In resting platelets, integrins are expressed in a low-affinity state but they shift to a high-affinity state and efficiently bind their ligands in response to cellular activation.
Are integrins alpha helices?
The α and β integrin chains are both class-I transmembrane proteins: they pass the plasma membrane as single transmembrane alpha-helices.
Why is clot retraction important?
Clot retraction is a physiologically important mechanism allowing: (1) the close contact of platelets in primary hemostasis, easing platelet aggregation and intercellular communication, (2) the reduction of wound size, (3) the compaction of red blood cells to a polyhedrocyte infection-barrier, and (4) reperfusion in …
Do platelets express CD41?
Quiescent platelets express a large number of surface proteins, including CD9 (tetraspanin), CD29 (integrin β1), CD31 (platelet endothelial cell adhesion molecule [PECAM-1]), CD36 (GPIV), CD41 (integrin αIIb), CD42a (GPIX), CD42b (GPIbα), CD61 (integrin β3) and GPVI2,3. Surface levels of some of these molecules (e.
What does thromboxane A2 do?
Thromboxane-A Synthase Thromboxane A2 induces platelet aggregation as well as vascular and respiratory smooth muscle contraction. Its actions are completely opposite to those of prostacyclin I2.
Do platelets have integrins?
Platelets contain five integrins, three beta1 integrins that mediate platelet adhesion to the matrix proteins collagen, fibronectin and laminin, and the beta3 integrins alphavbeta3 and alphaIIbbeta3  [J Clin Invest, 2005; 115: 3363].
Does aspirin inhibit platelet aggregation?
It seems that resistance to aspirin may be associated with an increase of arterial thrombotic events in spite of chronic intake. In ex vivo assays using aggregometry, with sodium arachidonate as agonist, aspirin inhibits platelet aggregation irreversibly in most people.