Effects of glucocorticoid on RAGE-NF-κB pathway in hyperoxia-induced lung tissues of neonatal rats / 中国当代儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the change of RAGE-NF-κB signaling pathway during the course of hyperoxia-induced lung injury in newborn rats, and the effect of glucocorticoid on this pathway.</p><p><b>METHODS</b>Twenty-four Sprague-Dawley neonatal rats were randomly divided into three groups (n=8 each) sham control (control group), hyperoxia-induced acute lung injury (model group) and glucocorticoid-treated acute lung injury (glucocorticoid group). Rats were sacrificed at 13 days after birth. RAGE and NF-κB expression levels in lung tissues were detected by reverse transcription polymerase chain reaction, Western blot and immunohistochemistry analysis. The levels of tumor necrosis factor α (TNF-α) and sRAGE in bronchoalveolar lavage fluid (BALF) and serum were measured using ELISA. Lung damage was evaluated by histological examinations.</p><p><b>RESULTS</b>RAGE and NF-κB mRNA and protein expression levels in lung tissues were significantly increased in the model and glucocorticoid groups compared with the control group (P<0.05). Serum RAGE concentrations were significantly increased but RAGE concentrations in BALF were significantly reduced in the model and glucocorticoid groups compared with the control group (P<0.05). RAGE and NF-κB expression at both mRNA and protein levels in lung tissues was significantly lower in the glucocorticoid group than in the model group (P<0.05). RAGE concentrations were significantly lower in serum (P<0.05), but were higher in BALF (P<0.05) in the glucocorticoid group than in the model group.</p><p><b>CONCLUSIONS</b>RAGE-NF-κB pathway plays an important role in hyperoxia-induced lung injury in neonatal rats, and glucocorticoid administration may play a protective role against the lung injury by down-regulating RAGE-NF-κB signaling pathway.</p>