Single-cell RNA analysis reveals the cell atlas of human intracranial aneurysm and rupture-related inflammation features

BackgroundIntracranial aneurysms (IA) is a common condition and may ultimately result in life-threatening hemorrhagic strokes. A precise understanding of the cellular and gene expression perturbations in human IA tissue may enlighten additional therapeutics for unruptured IA. MethodsA total of 21,332 qualified cells were obtained from four cell-sparse ruptured and unruptured human IA tissues. Detailed cell atlas and dynamics, gene expression perturbations, and inflammation features were thoroughly investigated using multiple machine learning-based algorithms. ResultsEndothelial cells, smooth muscle cells (SMCs), fibroblasts and, for the first time, pericytes have been identified in human IA tissue. A significant proportion of immune cells are also identified, with the number of monocyte/macrophages and neutrophils being notably higher in ruptured IA. By leveraging external datasets, macrophages characterized by transcriptional activation of NF-{kappa}B and HIVEP2 is most strongly associated with IA rupture. Interestingly, the recruitment and activation of macrophages and their functional characteristics in terms of TNF and chemokine production remain consistent between unruptured and ruptured IA. ConclusionsThis study provides insights into the pathophysiology and molecular underpinnings of the IA wall and may motivate novel therapeutic options for unruptured IA.