Abstract 11378: Dynamic Secretion Analysis by Novel Microfluidic Platform mFLISA Reveal Contextual and Precise Paracrine Signatures Preventing Cardiac Injury
It is now increasingly recognized that a variety of stem cells offer therapeutic benefit to injured tissues via paracrine signaling. Paracrine signaling via secreted ligands is an important mediator of cell function. It has been a challenge to precisely measure cellular secretions in relevant physiological contexts. Here we introduce a high throughput platform combining protein microprinting and microfluidics, μFLISA, to directly measure cellular secretion and estimate the kinetics for the detected secretome (Fig. 1A). μFLISA design allows for precise evaluation of the diffusion of secreted molecules, as well as retroactive determination of the dynamics of secretion without time course measurements (Fig. 1B). Furthermore, its unique architecture facilitates precise control over measurement timings in response to arbitrary biological stimuli. Using μFLISA we estimated the secretion dynamics for different constituents of the secretome for bone marrow derived stem cells (BMSCs), reported to provide benefit in response to myocardial injury. We found that secretory kinetics are highly contextual and are regulated in response to individual factors present in myocardial infarction, e.g. hypoxia (Fig. 1B). Using an in vitro model of ischemia reperfusion with human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs), we estimated the absolute concentration of BMSC secretome in response to reperfusion insult (Fig. 1C). We provide strong evidence for the hypothesis that secretion by stem cells is contextual, is regulated by injury signals from myocardium, and that both the absolute concentration and dynamics of paracrine signaling determines cardioprotection. Precise estimation of concentration and kinetics of BMSC secretome will facilitate our understanding of the molecular mechanisms involved in stem cell mediated cardioprotection, as well as pave the way towards a cell-less therapy by mimicking the paracrine signaling by stem cells.
Author Disclosures: K. Kshitiz: None. D.D. Ellison: None. Y. Suhail: None. J. Afzal: None. L. Woo: None. A. Levchenko: None.
- © 2016 by American Heart Association, Inc.