Characterization and Significance of Monocytes in Acute Stanford Type B Aortic Dissection
Li Lü, Yuanhao Tong, Wenwen Wang, Yayi Hou, Huan Dou, Zhao Liu
Abstract
Acute aortic dissection (AAD) is one of the most common fatal diseases noted in vascular surgery. Human monocytes circulate in dynamic equilibrium and display a considerable heterogeneity. However, the role of monocytes in AAD remains elusive. In our recent study, we firstly obtained blood samples from 22 patients with Stanford type B AAD and 44 age‐, sex‐, and comorbidity‐matched control subjects. And the monocyte proportions were evaluated by flow cytometry. Results showed that the percentage of total CD14 + monocytes in the blood samples of Stanford AAD patients was increased significantly compared with that of normal volunteers ( P < 0.0005), and the absolute numbers of CD14 bright CD16 + and CD14 bright CD16 - monocytes both increased significantly regardless of the percentage of PBMC or CD14 + cells, while CD14 dim CD16 + monocytes displayed the opposite tendency. However, the percentage of CD14 + cells and its three subsets demonstrated no correlation with D‐dimer (DD) and C‐reactive protein (CRP). Then, blood mononuclear cell (PBMC) samples were collected by Ficoll density gradient centrifugation, followed with CD14 + magnetic bead sorting. After the purity of CD14 + cells was validated over 90%, AAD‐related genes were concentrated in CD14 + monocytes. There were no significant differences observed with regard to the mRNA expression levels of MMP1 ( P = 0.0946), MMP2 ( P = 0.3941), MMP9 ( P = 0.2919), IL-6 ( P = 0.4223), and IL-10 ( P = 0.3375) of the CD14 + monocytes in Stanford type B AAD patients compared with those of normal volunteers. The expression levels of IL-17 ( P < 0.05) was higher in Stanford type B AAD patients, while the expression levels of TIMP1(P<0.05), TIMP2(P<0.01), TGF-β1 ( P < 0.01), SMAD3 ( P < 0.01), ACTA2 ( P < 0.001), and ADAMTS-1 ( P < 0.001) decreased. The data suggested that monocytes might play an important role in the development of Stanford type B AAD. Understanding of the production, differentiation, and function of monocyte subsets might dictate future therapeutic avenues for Stanford type B AAD treatment and can aid the identification of novel biomarkers or potential therapeutic targets for decreasing inflammation in AAD.