Effect of acute lung injury on ?-defensin-2 gene expression in rat lung / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of acute lung injury (ALI) on ?-defensin-2 (RBD-2) gene expression in rat lung. Methods Sixty SD male rats weighing 250-300g were randomly divided into two groups of 30 animals each control group and ALI group. Animals were anesthetized with intraperitoneal 5% phenobarbital 120mg?kg-1 . In ALI group acute lung injury was induced with LPS 200 ?g?kg-1 iv. Lungs were harvested before (0h) and 6h, 18h, 1d, 3d and 5d after LPS stimulation. Total RNA was extracted from pulmonary tissue and RBD-2 mRNA was measured by reverse transcription polymerase chain reaction(RT-PCR). GAPDH was used as internal standard. DNA sequencing was used to confirm the specificity of RBD-2 cDNA fragment. Results Acute lung injury induced by intravenous LPS was confirmed by microscopic pathological examination. The level of RBD-2 mRNA in rat lung was 0.77?0.14 in control group. There were no significant changes in pulmonary RBD-2 mRNA expression at different time intervals in control group. In ALI group the RBD-2 mRNA expression at 6h after LPS stimulation was not significantly different from that in control group, whereas a marked increase in pulmonary RBD-2 mRNA was found at 12h and on 1d, 3d and 5d after LPS stimulation as compared with that in control group.Conclusions ?-defensin-2 gene expression shows a constitutive expression pattern. ALI can upregulate the ?-defensin-2 gene expression. The upregulation of ?-defensin-2 gene expression may be involved in the pathogenesis of ALI