Abstract 195: Dose-Dependent Induction of Nitric Oxide Production in Human Induced Pluripotent Stem Cell-Derived Endothelial Cells by Poloxamer 188

Abstract

Background: Poloxamer 188 (P188), a triblock copolymer, protects against ischemia/reperfusion injury. The precise mechanisms remain incompletely understood. Human induced pluripotent stem cells (hiPSCs) constitute a unique model system, allowing the parallel generation of different cell types from individual patients to study drug-specific effects in human tissue. Here, we aimed to investigate the potential of P188 to induce nitric oxide (NO) production in hiPSC-derived endothelial cells (ECs) and its effect on cell viability during hypoxia-reoxygenation. Methods: hiPSC-ECs were cultured in phenol red-free endothelial Cell Growth Medium-2 and subjected to hypoxia (1% oxygen) at 37°C for 36 hours. At the end of hypoxia, the cell culture medium was supplemented with NO-sensitive fluorescent dye DAF-FM diacetate (1:5000 dilution, final concentration 1 uM, 30 min). Hypoxic medium was removed, and P188 at different concentrations (0.1 nM to 100 nM) was added for 8 hours. DAF fluorescence and cell viability were assessed at the end of reoxygenation. One-Way ANOVA & Dunn's post hoc test was utilized for statistical analysis (* P < 0.05 vs. untreated control group). Results: P188 dose-dependently increased hiPSC-ECs viability (control group: 53±2%, 0.01 nM P188: 59±2%, 100 nM P188: 64±5%). Interestingly, DAF fluorescence increased dose-dependently as well (control group: 182±9%, 0.1 nM P188: 199±11%, 100 nM P188: 264±4%, data expressed as percent of normoxic cells, n=3 / treatment). Conclusion: This suggests that P188 protects hiPSC-ECs with increased NO production, shedding new light on the underlying mechanisms of its cardioprotective effects.