Development and Validation of a Flow-Dependent Endothelialized 3D Model of Intracranial Atherosclerotic Disease

Area of Science:

• Neuroscience
• Vascular Biology
• Biomedical Engineering

Background:

• Intracranial atherosclerotic disease (ICAD) is a significant global cause of stroke.
• Limited availability of animal models hinders the study of ICAD-specific mechanisms.
• Existing research often presumes shared mechanisms with atherosclerosis in other vascular regions.

Purpose of the Study:

• To develop a patient-specific in vitro model of the middle cerebral artery (MCA) for studying ICAD.
• To investigate flow dynamics and endothelial cell responses in ICAD using patient-derived models.
• To identify novel molecular pathways and therapeutic targets for ICAD-related stroke.

Main Methods:

• Developed a workflow to create patient-specific MCA models from neuroimaging (e.g., CT angiography).
• Endothelialized models with human endothelial cells and subjected them to controlled flow forces.
• Validated the model using imaging data from the SAMMPRIS clinical trial.
• Employed computational fluid dynamics (CFD) for flow velocity analysis.
• Utilized single-cell RNA sequencing (scRNA-seq) to analyze endothelial gene expression.
• Applied confocal microscopy to assess endothelial cell morphology and proliferation.

Main Results:

• Demonstrated strong correlation between CFD flow velocities and particle-derived flow, irrespective of stenosis degree.
• Observed varying degrees of post-stenotic flow disruption correlating with stenosis severity.
• Identified flow-dependent endothelial gene expression and distinct endothelial subclusters in diseased MCA segments via scRNA-seq.
• Discovered upregulated genes associated with atherosclerosis in diseased MCA segments.
• Revealed flow-dependent alterations in endothelial cell proliferation and morphology using confocal microscopy.

Conclusions:

• The developed patient-specific MCA model provides a reproducible platform for studying ICAD.
• This model enables detailed investigation of ICAD lesions and underlying molecular pathways.
• Findings highlight the critical role of flow dynamics in ICAD pathogenesis.
• The platform is crucial for developing targeted therapies for ICAD-related stroke, addressing a significant unmet clinical need.