BACKGROUND: Lung ischemia/reperfusion injury (LIRI) is a medical problem featuring pulmonary dysfunction and damage. The present study aimed to investigate the protective effects of erythropoietin (EPO), which has been reported to be an anti-inflammatory agent, on LIRI through inhibiting the TLR-4/NF-κB signaling pathway.

MATERIAL AND METHODS: All rats were randomly divided into 3 groups (n=8): a control group, a vehicle+LIRI group, and an EPO+LIRI group. LIRI included 90-min ischemia and 120-min reperfusion, while RhEpo was administered (3 kU/kg) intraperitoneally 2 h before the operation. Levels of pulmonary inflammatory responses were examined by analyzing pulmonary permeability index (PPI), oxygenation index, histology, and expressions of inflammatory cytokines.

RESULTS: Pretreatment with EPO significantly decreased lung W/D ratio, BALF leukocytes count and percentage, and PPI but increased oxygenation index compared with the LIRI group (P<0.05). More importantly, with EPO pretreatment there was less pathological damage compared with the vehicle group. Expressions of inflammatory cytokines (TNF-α, IL-6, and IL-1β) in the serum were significantly lower in the EPO group than in the LIRI group (P<0.05). In addition, gene expression and protein expression of TLR-4 and NF-κB were significantly inhibited with EPO pretreatment compared with the LIRI group (P<0.05).

CONCLUSIONS: Our study id the first to report that EPO protects lung injuries after LIRI through inhibiting the TLR4-NF-κB signaling pathway, which provides solid evidence for the use of EPO as a therapeutic agent for treating LIRI in the future.

Keywords: Erythropoietin