Upregulation of Tie2 receptor and enhancement of angiogenesis and arteriogenesis by gene transfer of angiopoietin-1 in rat models of acute myocardial infarction / 中国介入心脏病学杂志

ABSTRACT

Objective To investigate the possible mechanisms of enhancing angiogenesis and arteriogenesis through the oberservation of the effect of gene transfer of angiopoietin-1 (Ang1) on its receptor Tie2 in rat models of acute myocardial infarction. Methods Myocardial infarction was induced in rats by left anterior descending artery ligation. Naked plasmid DNA encoding human angiopoietin-1 (phAng1) was delivered into the ischemic area (group A) by intramyocardial injection. On day 3, 7, 14 and 28 after the injection, the mRNA expression of Tie2 and its changes with time were determined by RT-PCR. The number of vessels and arterioles was examined by immunohistochemistry. The collagen was evaluated by Masson staining. Results RT-PCR showed that mRNA expression levels of Tie2 in group A were significantly higher than those in the control group, reached the highest level on day 7 post-injection, and gradually declined to normal level 28 days later. On day 7, 14 and 28, the vessel count showed the number of blood vessels (angiogenesis and arteriogenesis) in group A was greater than that of the control group at the same timepoint and the infracted myocardium in group A was significantly less than that of the control group. Conclusion Gene transfer of phAng1 enhances angiogenesis and arteriogenesis in acute myocardial infarction and reduces the infraction area probably by upregulating the expressions of Tie2 receptor.