Chronic consequences of ischemic stroke: Profiling brain injury and inflammation in a mouse model with reperfusion

Stroke is a pervasive and debilitating global health concern, necessitating innovative therapeutic strategies, especially during recovery. While existing literature often focuses on acute interventions, our study addresses the uniqueness of brain tissue during wound healing, emphasizing the chronic phase following the commonly used middle cerebral artery (MCA) occlusion model. Using clinically relevant endpoints in male and female mice such as magnetic resonance imaging (MRI) and plasma neurofilament light (NFL) measurement, along with immunohistochemistry, we describe injury evolution. Our findings document significant alterations in edema, tissue remodeling, and gadolinium leakage through MRI. Plasma NFL concentration remained elevated at 30 days poststroke. Microglia responses are confined to the region adjacent to the injury, rather than continued widespread activation, and boron-dipyrromethene (BODIPY) staining demonstrated the persistent presence of foam cells within the infarct. Additional immunohistochemistry highlighted sustained B and T lymphocyte presence in the poststroke brain. These observations underscore potentially pivotal roles played by chronic inflammation brought on by the lipid-rich brain environment, and chronic blood-brain barrier dysfunction, in the development of secondary neurodegeneration. This study sheds light on the enduring consequences of ischemic stroke in the most used rodent stroke model and provides valuable insights for future research, clinical strategies, and therapeutic development.