5th International Conference on ENT: Head and Neck Surgery

Nogah Nativ Zeltzer is a Senior Lecturer at the Tel Aviv University Gray Faculty of Medical and Health Sciences and head of the TAU Swallow Physiology Lab. Dr. Nativ Zeltzer received her Ph.D. from Northwestern University and conducted her postdoctoral training at the University of California Davis Department of Otolaryngology-Head and Neck Surgery, where she was the recipient of the Dickenson Fellowship. Dr. Nativ-Zeltzer’s research focuses on the prevention and treatment of swallowing disorders and aspiration pneumonia in individuals with dysphagia.

Aspiration pneumonia is a major cause of morbidity and mortality in adults with swallowing impairment. Exosomes derived from mesenchymal stromal cells (MSCs) have anti-inflammatory properties and may represent a potential therapeutic approach for aspiration-induced lung injury. This preliminary study evaluated whether MSC-derived exosomes mitigate pulmonary inflammation and injury in a rat model of aspiration. Seventeen adult male rats were assigned to three groups. Animals in the LPS-Exo group (n=7) underwent intratracheal instillation of lipopolysaccharide (LPS; 2.5 mg/kg) followed by intravenous administration of 40 µL MSC-derived exosomes. The LPS-only group (n=7) received LPS without exosome treatment, while sham controls (n=3) underwent intratracheal air instillation. Animals were euthanized 6 hours after instillation. Lung injury was assessed using semi-quantitative histopathologic scoring, and expression of pro- and anti-inflammatory cytokines was evaluated using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Mean composite histologic lung injury scores were 8.3 (±1.1) in the LPS-only group, 7.13 (±3.2) in the LPS-Exo group, and 3.3 (±1.1) in sham controls. One-way ANOVA demonstrated a significant group effect (p=0.02), with trend analysis showing significant linear improvement across groups (p=0.006; η²=0.43). Tnf expression was significantly lower in the LPS-Exo group than in the LPS-only group (p<0.05). No other significant between-group differences in gene expression were identified. These preliminary findings suggest that intravenous MSC-derived exosomes may reduce Tnf expression and attenuate histopathologic lung injury following acute aspiration. Further studies are warranted to confirm these findings and characterize the underlying mechanisms and therapeutic potential of MSC-derived exosomes.