Thrombin-reduced miR-27b attenuates platelet angiogenic activities via enhancing platelet de novo synthesis of anti-angiogenic thrombospondin-1

To identify if platelet activation would result in altered platelet miRNA profile, not only in total RNA sample, also in AGO2-immunoprecipitation(AGO2-IP) products. To determinate if altered platelet miRNAs could regulate de novo protein synthesis of angiogenic factors in activated platelets, and even more importantly, if miRNA-regulated platelet angiogenic factor synthesis could result in changes of platelet angiogenic activities. Platelets samples stimulated with thrombin or vehicle, and followed by AGO2-immunoprecipitation (AGO2-IP) or total RNA extraction. Then, we performed miRNA expression profiling using a microarray approach. Significant differentially expressed miRNAs among groups were identified using SAM analysis. To validate the results of SAM, the expression levels of selected miRNAs were evaluated using qRT-PCR.