133 - Effect of Umbilical Cord Blood-Derived Large vs Small Extracellular Vesicles in Prevention of Lung Epithelial Cells Injury

Poster Number: 133
Publication Number: 133.436

Mohammed Abdulmageed, Michigan State University College of Human Medicine/Sparrow Hospital Regional Neonatal Intensive Care Unit, East Lansing, MI, United States; Hattan Arif, Michigan State University: Department of Pediatrics and Human Development, Haslett, MI, United States; Sherif Abdelfattah, Michigan State University, East Lansing, MI, United States; Hend Mohamed, Pediatrics and Human development, MSU, Lansing, MI, United States; Amal Abdul-Hafez, Michigan State University College of Human Medicine, East Lansing, MI, United States; Ranga Prasanth Thiruvenkataramani, Michigan State University College of Human Medicine, Lansing, MI, United States; Myrna Y. Gonzalez Arellano, Michigan State University College of Human Medicine, Lansing, MI, United States; Amira MA. Othman, Michigan State University College of Human Medicine, East Lansing, MI, United States; Burra V. Madhukar, Michigan State University, E. Lansing, MI, United States; Tarek Mohamed, Michigan State University College of Human Medicine, East Lansing, MI, United States; Said Omar, Michigan State University College of Human Medicine, Lansing, MI, United States

Background: Bronchopulmonary Dysplasia (BPD) is a major cause of morbidity and mortality in preterm infants. Inflammation secondary to hyperoxia, mechanical ventilation, and sepsis is a key factor in disruption of normal lung development and the development of BPD. There is no proven effective therapy for prevention or treatment of BPD. Extracellular vesicles (EVs) are secreted from all cells in the body as carriers of biological loads. EVs are categorized based on their size as large (diameter 100-1000nm) and small (diameter 30-150 nm). Umbilical cord blood (CB) is a rich source of EVs. Previous work from our lab has shown that placental small EVs are associated with anti-inflammatory and regenerative capabilities.

Objective: To determine the effect of large EVs (CB-LEVs) compared with small EVs (CB-sEVs) on A549 lung alveolar epithelial cells for apoptosis and necrosis under normoxia. Our hypothesis is that CB-LEVs and sEVs are protective against apoptosis and necrosis.

Design/Methods: CB samples were collected from healthy Full-term pregnancies after obtaining maternal consent. Plasma from CB was collected and filtered to obtain LEVs, then sEVs were obtained by ultrafiltration. Particle-size distribution was done by nanoparticle tracking analysis (NTA). The presence of the EVs surface markers Alix, flotillin-1 and CD-9 was checked by western blotting. The cultured A549 cells were incubated +/- LEVs or sEVs for 72 hours in room air with 5% CO2 condition. Then cell apoptosis and necrosis were determined by Annexin V Apoptosis and Necrosis Assays. Data was analyzed using ANOVA. 

Results: The results of NTA and western blotting are shown in Fig-1 and confirmed the size distribution, and presence of EVs surface markers in CB-EVs. Fig-2&3 shows the results of apoptosis/necrosis assays. Apoptosis of A549 was significantly reduced in cells treated with either sEVs or LEVs in comparison with untreated A549 cells (p < 0.01). Apoptosis and necrosis were significantly lower in cells treated with LEVs than cells treated with sEVs or untreated cells (p <0.01).

Conclusion(s): Our data shows that CB-LEVs prevent A549 cell apoptosis and necrosis significantly more than CB-sEVs in normoxia. Further work is underway to examine the effect of LEVs and sEVS in preventing hyperoxia and sepsis induced lung epithelial cells injury, a key factor in the development of BPD in neonates.