Differences in Stem Cell Processing Lead to Distinct Secretomes Secretion—Implications for Differential Results of Previous Clinical Trials of Stem Cell Therapy for Myocardial Infarction

Stem cell therapy for acute myocardial infarction (AMI) seemed to be a promising therapy, however, large clinical trials brought differential outcome. It has been shown that paracrine effects of secretomes of stem cells rather than cell therapy might play a fundamental role. The present study seeks to compare cell processing protocols of clinical trials and investigate effects of differential cell culture conditions on chemokine secretion and functional effects. Different secretomes are compared regarding IL‐8, VEGF, MCP‐1, and TNF‐alpha secretion. Secretome mediated effects are evaluated on endothelial cell (HUVEC) tube formation and migration. Cardioprotective signaling kinases in human cardiomyocytes are determined by Western immunoblotting. Cells processed according to the REPAIR‐AMI protocol secrete significantly higher amounts of IL‐8 (487.3 ± 1231.1 vs 9.1 ± 8.2 pg mL−1; p