324 - Therapeutic Potential of Human Extremely Preterm Umbilical Cord Derived Mesenchymal Stem Cell Exosomes Exposed to Extremes of Oxygen Conditions in Murine Experimental Bronchopulmonary Dysplasia

Publication Number: 324.6783

BRYSTON CHANG, University of California, Irvine, School of Medicine, Orange, CA, United States; Fayez Bany-Mohammed, UC Irvine Medical Center, Orange, CA, United States; Cherry Uy, University of California, Irvine, School of Medicine, Orange, CA, United States; Muhammad Aslam, UCI, Orange, CA, United States

Background: Bronchopulmonary Dysplasia (BPD) is a chronic debilitating disease of preterm infants resulting from oxygen toxicity (prolonged hyperoxia with periods of intermittent hypoxia), inflammation, and ventilator use leading to arrested alveolar development. Our studies using human term umbilical cord derived MSCs have shown partial efficacy in murine experimental BPD. At present, it is unclear if human preterm umbilical cord MSCs will have therapeutic efficacy in murine BPD, especially when these cells are exposed to experimental BPD conditions.

Objective: Our aims included generation of MSCs from preterm 22-24 weeks’ GA umbilical cords and growth in experimental BPD conditions followed by assessment of therapeutic efficacy in murine BPD.

Design/Methods: The umbilical cord MSCs harvested from extremely preterm 22-24 weeks’ GA cords. These MSCs were cultured for 48-hours under extremes of oxygen conditions as follows:
Group A: Control cells in Normoxia (21% O2).
Group B: Hyperoxia (90% O2).
Group C: Hypoxia (5% O2).
Group D: Hyperoxia (90% O2) with intermittent hypoxia (5% O2) for one hour every 6 hours.
The umbilical cord MSCs and their exo generated and MSC-exo content analysis performed. FVB mice placed in hyperoxia (90% O2) within 24 hours of life until day of life 14 when placed back in Normoxia (21% O2). Control animals remained in Normoxia. At day 14, animals injected with 0.1 microgram/g MSC-exo via jugular vein. At day 28, pulmonary function testing and echocardiogram performed to assess lung function and pulmonary hypertension.

Results: MSC-exo miRNA analysis demonstrated decreased cell injury and repair miRNA profile in MSC-exo exposed to extremes of oxygen conditions (Fig. 1). Group D and B MSC-exo lacked therapeutic efficacy with lung injury with lower lung inspiratory capacity and compliance in hyperoxia exposed animals when compared with group A and C (Fig. 2). Similarly, group D and B MSC-exo failed to prevent pulmonary hypertension with thickened right ventricular wall and decreased pulmonary artery acceleration time on echocardiogram analysis when compared with group A and C (Fig. 3). Group C only provided partial protection of lung injury and pulmonary hypertension when compared with group A. All these results were statistically significant.

Conclusion(s): Clinical BPD conditions (Hyperoxia as well as hyperoxia alternating with hypoxia) alter the biologic potential of human preterm umbilical cord derived MSCs with lack of protected miRNAs involved in lung injury and repair.

Figure 1
MicroRNA analysis of MSC-Exosomes

Figure 2
Lung Function Test in animals treated with MSC-Exosomes

Figure 3
Pulmonary Hypertension Assessment in animals treated with MSC-Exosomes