Author + information
to investigate the mechanisms by which Qanqi pills (DQP) promote angiogenesis in ischemic heart tissues. Key molecules in prolyl hydroxylase-2/hypoxia inducible factor-1 α (PHD2/HIF-1α) angiogenic pathway were detected.
Myocardial ischemia model of rat was induced by left anterior descending coronary artery ligation. 20 Sprague-Dawley Rats were randomly divided into four groups: sham-operated group, model group, DQP-treated group and control drug fosinopril-treated group. Seven days after operation, heart functions were evaluated by echocardiography. Rats were sacrificed and heart tissues in infarct border zone were preserved for immumohistochemical staining or western blotting analysis. Expressions of cluster of differentiation 31 (CD31), HIF-1α and Vascular endothelial growth factor (VEGF) were detected by immunohistochemical staining. Protein expressions of PHD2 and HIF-1α were quantified by western blotting analysis.
Ejection fraction (EF) and fraction shortening (FS) of rats in model group were significantly lower than those in sham-operated group, whereas treatments with DQP improved both EF and FS at 7 days after operation, indicating that DQP exerts cardio-protective effects under ischemic conditions. Expressions of CD31, a protein marker for the presence of endothelial cells, were lower in model group than those in sham-operated group. In DQP-treated group, expressions of CD31 were higher than those in model group, indicating that DQP promotes angiogenesis around ligation areas. Expressions of HIF-1α and VEGF in DQP-treated group were higher than those in model group. Notably, expressions of PHD2, an inhibitor of HIF-1α, were down-regulated in DQP-treated group as shown by western blotting analysis.
Our results showed that DQP treatment could improve cardiac functions and promote angiogenesis under conditions of myocardial ischemia. The pro-angiogenic effect of DQP is possibly mediated by inhibiting PHD2 at the early stage of myocardial ischemia. [This work was supported by a grant from Beijing University of Chinese medicine (No. 2015-JYB-QNJSZX001) to Qiyan Wang].