Gene expression profile of lung tissues in rats with high altitude pulmonary edema

Objective To analyze the differential expressed genes (DEGs) in the lung tissues of rat model of high altitude pulmonary edema (HAPE) by using microarray analysis in order to provide new clues for molecular mechanism of HAPE. Methods Healthy male SD rats (8 weeks old, weighing 200±20 g) were randomized into normoxia control (NC) group, lipopolysaccharide (LPS) group, hypoxia group and hypoxia +low-dose LPS (HL) group. The rats of the LPS group and HL group were injected with 0.1 mL 0.05% LPS per 100 g body weight, and those of the NC group and the hypoxia group were administered with an equivalent volume of normal saline. The rats of the hypoxia group and the HL group were housed in a hypobaric chamber simulating an altitude of 5 000 m, and those of the NC group and the LPS group were raised simultaneously outside of the chamber. The wet/dry mass ratio (WDR) of lung tissue and total protein content in bronchoalveolar lavage fluid (BALF) were measured, and the histopathological changes of lung tissue was observed using HE staining. The total RNA was extracted from the lung tissues, and the mRNA expression profile was obtained with Affymetrix microarray followed by Gene Ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis with Metascape (http://metascape.org). Results The rats of the HL group showed significant congestion, edema, and widened alveolar septa. Compared with the NC group, the HL group had significantly increased lung WDR (P