Abstract 14416: The Redox Effect of Stem-Cell Derived Extracellular Vesicles on Normal and Diabetic Human Coronary Artery Endothelial Cells

Abstract

Introduction: Cardiovascular disease continues to be the leading cause of death globally, necessitating the study of novel therapeutic modalities. Following the lack of success with stem-cell based therapies, their extracellular vesicles (EVs) have emerged as a promising strategy. Hypothesis: We hypothesized that EVs will reduce oxidative stress in normal and diabetic human coronary artery endothelial cells (HCAEC). Methods: Human bone marrow-derived stem cells (HBMSC) were grown to passage 7 and subject to 24 hours of preconditioning by serum starvation media. EVs were then isolated via ultracentrifugation and submitted for LC-MS/MS for proteomics. Normal HCAEC and diabetic HCAEC (DM-HCAEC) were starved for 12 hours then treated with vehicle (1% DMSO in PBS) or EVs (1x108 particles/ml) for 6 hours. Following treatment, mitochondrial (mito) ROS using mitosox, total ROS using DCF-DA, and protein expression using Western blots were analyzed by 2-way ANOVA with Bonferroni multiple-comparisons correction. Results: A total of 473 EV proteins were identified, among which were antioxidants catalase, thioredoxin, peroxiredoxins, SOD1, and ferritin. EV-treatment reduced mito-ROS levels significantly in HCAEC, but not in DM-HCAEC. Basal (ambient) levels of total ROS in DM-HCAEC were significantly higher compared to HCAEC (p=0.0393), however, EV treatment reduced total ROS in both cell types significantly (p=0.002). Western blot analysis revealed that EV increased mitochondrial antioxidant MnSOD (SOD2) levels in HCAEC but not in DM-HCAEC. Catalase expression was unaffected by EV treatment in both cell types. Conclusions: EVs displayed differential effects on the mito-ROS, but reduced total ROS in both HCAEC and DM-HCAEC. EV-induced reduction in mito-ROS in non-diabetic HCAEC plausibly resulted from corresponding increase in MnSOD expression. Data from our ongoing studies will be presented at the meeting demonstrating whether the above changes in redox states by EVs correspond to differential proliferation, migration and angiogenesis in HCAEC vs. DM-HCAEC.