Abstract 19641: Novel Microprinted Elisa Platform for High Throughput Screening of Protein Secretion Reveals a Comprehensive Strategy to Prevent Ischemia Reperfusion Induced Apoptosis

Introduction: A major challenge in using stem cells to treat myocardial infarction (MI) is the massive cell death post transplant. Many progenitor cell types limit disrepair post MI without significant cardiac differentiation, possibly by anti-apoptotic signals in their secretions. The signature of these secretions is however not well known. Methods: We created a novel high throughput microELISA platform by combining microprinting and microfluidics to precisely estimate secretions of a small population of cells over time. Screening the secretions in many stem cell types used previously to treat MI, i.e. BMSCs (Bone marrow derived stem cells), CDCs (Cardiosphere derived cells), and iPSC-CMs (induced pluripotent stem cell derived cardiomyocytes), we found a common preserved secretory signature of growth factors. Results: Using a high throughput screen of pro-apoptotic factors that prevent CDCs from peroxide induced cell death, we surprisingly found that these factors were identical to the preserved secretory signature. Using the constituents of the anti-apoptotic secretory signature in combination with ischemic and mechanical preconditioning in myocardium mimicking rigidity, we created a comprehensive cytoprotective cocktail to prevent CDCs from ischemia induced cell death. We tested the cocktail in a rat model of ischemia reperfusion, and found a stark reduction in CDC retention post injection. Figures: (A) MicroELISA schematic. Secretions from cells in left are detected by rows of microprinted capture antibodies; photograph in (C-D). Bioluminescence imaging of CDCs treated with comprehensive cocktail show significantly high cell retention vs untreated CDCs.