Endothelial cell malfunction in unruptured intracranial aneurysm lesions revealed using a 3D-casted mold

Intracranial aneurysms (IA) are major causes of devastating subarachnoid hemorrhages. They are characterized by a chronic inflammatory process in the intracranial arterial walls triggered and modified by hemodynamic force loading. Because IA lesion morphology is complex, the blood flow conditions loaded on endothelial cells in each portion of the lesion in situ vary greatly. We created a 3D-casted mold of the human unruptured IA lesion and cultured endothelial cells on this model; it was then perfused with culture media to model physiological flow conditions. Gene expression profiles of endothelial cells in each part of the IA lesion were then analyzed. Comprehensive gene expression profile analysis revealed similar gene expression patterns in endothelial cells from each part of the IA lesion but gene ontology analysis revealed endothelial cell malfunction within the IA lesion. Histopathological examination, electron microscopy, and immunohistochemical analysis indicated that endothelial cells within IA lesions are damaged and dysfunctional. Thus, our findings reveal endothelial cell malfunction in IA lesions and provided new insights into IA pathogenesis.