LAUSR

Background: AMR-001, an autologous CD34+ cell product derived from mini-marrow harvest, is currently undergoing Phase II trials to treat acute myocardial infarction (AMI). At the time of AMR-001 infusion, it is believed that the infarct-region stromal derived factor-1 (SDF-1) levels are peaked. It was found that improvement in cardiac perfusion and infarct size correlated with the mobility potential of CD34+ cells, as mediated by a SDF-1 gradient. We have initiated a study to identify potential microRNAs (miRNAs) and proteins that may be used as biomarkers that correlate to CD34+ cell migratory potential. Methods: In vitro transwell migratory assays were performed on purified CD34+ cells derived from bone marrow of healthy donors. After 4 hours at 37 C, CD34+ cells that migrated into the lower chamber in the presence of SDF-1, the non-mobilized cells in the upper chamber, and untreated cells were harvested. The miRNA expression profile was analyzed (Sistemic, Ltd) using microarray slides (Agilent). A biotin label-based antibody array (RayBiotech) was used for the detection of 1000 proteins. Results: Hierarchical clustering analysis of the miRNA data showed that mobilized cells grouped separately from the non-mobilized/untreated cells. Sixty-three miRNAs were upregulated in the mobilized samples compared to non-mobilized/untreated samples, including two miRNAs which have a reported pro-angiogenic role in migratory cells. Twenty-six proteins had higher expression in mobilized cells compared to non-mobilized cells. Several of the identified proteins have a role in migration or angiogenesis. Conclusion: Analysis of the miRNA and protein profiles of the CD34+ cells identified a number of miRNAs/proteins that represent possible markers for a migratory phenotype. qPCR and ELISA assays will be performed to verify the specific miRNAs and proteins identified. This approach will enable the development of a biomarker assay for migratory potential of AMR-001.