IL-5 overexpression attenuates aortic dissection by reducing inflammation and smooth muscle cell apoptosis

Abstract Background As an inflammation-related cytokine, interleukin (IL)-5 has been reported to be involved in the development of cardiovascular diseases, such as chronic heart failure and atherosclerosis. However, the role of IL-5 in acute aortic dissection (AAD) has barely been explored. Methods Aortic tissue samples from normal donors and patients with AAD were collected, and the expression and localization of IL-5 in aortic tissue were analyzed. In addition, a mouse AAD model was established by administering angiotensin II (Ang II) to β-aminopropionitrile (BAPN)-treated mice. Morphological examinations and histopathologic analyses were performed to evaluate the effects of IL-5 overexpression on the occurrence of AAD. Results IL-5 expression was significantly decreased in aorta samples from AAD patients compared to those from donors, and macrophages were the main source of IL-5. In addition, IL-5 expression was decreased in plasma and aortic tissue samples from AAD mice. IL-5 overexpression markedly attenuated the occurrence of AAD in mice and produced corresponding decreases in the inflammatory response and cell apoptosis. In cocultures of macrophages and smooth muscle cells (SMCs), IL-5 overexpression in the macrophages significantly reduced Ang II-induced SMC apoptosis. Conclusion IL-5 overexpression suppresses the development of AAD by reducing inflammation and SMC apoptosis. These results suggest that IL-5 is a potential therapeutic target in AAD.