Grant: $87,000 - National Institutes of Health - Aug. 1, 2009
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Award Description: Communication between platelet SERT and plasma 5HT: For the first time, we demonstrate that chronically elevating plasma 5HT in vivo by osmotic minipump in normal C57BL/6J mice results in a loss of surface SERT in platelets and a corresponding increase in platelet aggregation. Based on these findings we hypothesize that high plasma 5HT limits its own uptake in platelets by down-regulating SERT on the plasma membrane, resulting in a loss of intracellular 5HT but increased plasma concentrations of the amine. Then, our proteomic and biochemical analysis identified that platelet vimentin and Rab4 associated with SERT in a 5HT-dependent manner. Currently, we are investigating the link between elevated plasma 5HT and loss of surface SERT by focusing on the intracellular tethering of SERT by Rab4, and the 5HT-mediated phosphorylation of vimentin that promotes SERT internalization in platelets. However, the impact of high plasma 5HT level on platelet proteins cannot be limited to Rab4 and vimentin. There should be other proteins which are involved in cytosolic movement of SERT and affected by alteration in the plasma 5HT concentration. This Administrative Supplement project is designed to identify the impact of high plasma 5HT level on the expression patterns of genes in isolated megakaryocytes from the bone marrow of 5HT-infused and saline-infused mice by microarray assay and confirm our findings with RT-PCR and biochemical assays. Evaluating the impact of plasma 5HT on genome-wide gene expression in megakaryocyte will accelerate the pace of our understanding in the communication link between plasma 5HT and platelet SERT.
Project Description: Currently we are working on the marrow cells to grow for further experimental procedures as stated in our grant proposal. As described in our parent proposal, adult C57BL/6J mice will be implanted with osmotic minipumps that infuse equal volumes of either saline or 5HT (1.66 ?g/kg/hr) dissolved in saline for 24 hr. A third group of mice will not be implanted with osmotic minipumps ('no treatment group). After 24 hours, we will first collect the blood by cardiac puncture in anesthetized mice to study the proposed experiments in our parent grant; then the right and left femur will be dissected from the mice.
Infrastructure Description: n/a
Jobs Summary: n/a (Total jobs reported: 0)
Project Status: Less Than 50% Completed
This award's data was last updated on Aug. 1, 2009. Help expand these official descriptions using the wiki below.