Single-Cell RNA-Seq Analysis Reveals Macrophage Involved in Pathogenesis of Human sporadic type A aortic dissection

Macrophages play an important role in the progression of sporadic acute type A aortic dissection (ATAAD). The aim of this study was to characterize the cellular heterogeneity of macrophages in AD tissues by scRNA-seq. Ascending aortic wall tissue from 6 ATAAD patients and 3 heart transplant donors were assessed by scRNA-seq, then analyzed and validated by various bioinformatics algo-rithms and histopathology experiments. The results revealed the proportion of macrophages in AD tissues (24.51%) was significantly higher than that in normal tissues (13.69%). Among the 6 macro-phage subclusters, pro-inflammatory macrophages accounted for 14.96% in the AD group, and 0.18% in the normal group. Chemokine and inflammation related genes (CCL2, CCL20, S100A8, and S100A9) were expressed more intensively in macrophages in AD tissue than that in the normal tissues. Ad-ditionally, intercellular communication analysis and transcription factor analysis indicated activation of inflammation and degradation of the extracellular matrix in AD tissues. Finally, immunohisto-chemistry, immunofluorescence and western blot experiments confirmed the overexpression of macrophage marker genes (CD68 and CD163) and matrix metalloproteinases (MMP9 and MMP2) in AD tissues. Collectively, our study provides a preliminary evaluation of the role of macrophages in AD and potentially aid in the development of therapeutic options in the future. Overall design: We performed scRNA sequencing to understand macrophage function in in Pathogenesis of Human sporadic type A aortic dissection. We analyzed and validated by various bioinformatics algorithms and histopathology experiments.