Expression and Correlation of Hypoxia-Inducible Factor-1α (HIF-1α) with Pulmonary Artery Remodeling and Right Ventricular Hypertrophy in Experimental Pulmonary Embolism

BACKGROUND: We investigated the expression of HIF-1α (hypoxia-inducible factor-1α) and its correlations with pulmonary artery remodeling and right ventricular hypertrophy in PE (pulmonary embolism) rats. MATERIAL/METHODS: After the PE rat model was established, the dynamic changes of mPAP (mean pulmonary artery pressure), PAMT (relative medial thickness of small pulmonary arteries), WA/TA (vessel wall area/total area), and RVHI (right ventricular hypertrophy index) were detected. Then, histomorphology of pulmonary vascular was observed, followed by HIF-1α mRNA and protein for pulmonary artery and right ventricle were checked via in situ hybridization and immunohistochemistry, respectively. The correlations between HIF-1α and mPAP, PAMT, WA/TA, and RVHI were analyzed. RESULTS: The mPAP level increased from the initial time to 12 weeks of PE and reached the peak at 12 weeks. After 4 weeks of PE, PAMT increased compared with the initial control group (p<0.05), and increased further after 8 weeks and 12 weeks. Changes of the vessel WA/TA were the same as PAMT. Compared with the initial control group, RVHI increased at 8 weeks (p<0.05) and 12 weeks of PE (p<0.01). HIF-1α mRNA and protein were positively correlated with mPAP, PAMT, and WA/TA in pulmonary arteries. HIF-1α mRNA and protein were positively correlated with mPAP, PAMT, WA/TA, and RVHI in right ventricles (p<0.01). CONCLUSIONS: HIF-1α mRNA and protein are expressed in the pulmonary artery and right ventricular of PE rats, and HIF-1α may correlate with pulmonary artery remodeling and right ventricular hypertrophy in rats with PE.