Crosstalk Between Different Signaling Systems

The stimulus-response mechanisms in platelets are complex and involve foe variety of substances that stimulate different effector-systems in foe platelets, foe autocrine stimulation in response to platelet activation by a primary agonist as well as by cross-tall between signal transduction pathways. Cross-talk can happen at several stages of foe signal transduction pathway. The most studied are foe competition between stimulatory and inhibitory pathways, and examples are foe action of thrombin via G and PGIj via G, 

9 COMMUNICATION BETWEEN PLATELETS AND OTEffiR BLOOD CELLS 

Platelets communicates not only internally by different signaling pathways, but also with other blood cells in the circulation and the endothelium, to interact in hemostasis and inflammation. 

Hemostasis and inflammation involves adhesion of cells in the flowing blood to the vessel wall. Three main families of receptors are involved. 

Firstly, the Immunoglobulin Sxq)erfamily (IgSF) which is the most abundant family of cell surface molecules, and includes receptors for growth factors, receptors for the Fc region of Ig (where the FcRU-type is specifle for platelets) and adhesion molecules. An important 

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The ethiology of chronic inflammatory diseases differs from acute inflammation and is still poorly understood. One example is the chronic rheumatoid arthritis (RA), which is characterized by a chronic destructive arthropathy. In RA and other inflammatory bone diseases there is intense crosstalk between the skeleton and the immune system by the use of common cytokines and transcriptional pathways. A newly established research area - osteoimmunology - attempts to unravel this skeletal/immunological axis and several signaling pathways involved in inflammatory bone loss have been identified (Wagner and Eferl, 2005). One pathway... 

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