Title:The Stroke-Induced Blood-Brain Barrier Disruption: Current Progress of Inspection Technique, Mechanism, and Therapeutic Target
Volume: 18
Issue: 12
Author(s): Takeshi Okada, Hidenori Suzuki, Zachary D. Travis and John H. Zhang*
Affiliation:
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA 92354,United States
Keywords:
Blood-brain barrier, macrophage, microglia, neuroinflammation, programmed cell death, stroke, tight junction.
Abstract: Stroke is one of the leading causes of mortality and morbidity worldwide. The bloodbrain
barrier (BBB) is a characteristic structure of microvessel within the brain. Under normal
physiological conditions, the BBB plays a role in the prevention of harmful substances entering into
the brain parenchyma within the central nervous system. However, stroke stimuli induce the breakdown
of BBB leading to the influx of cytotoxic substances, vasogenic brain edema, and hemorrhagic
transformation. Therefore, BBB disruption is a major complication, which needs to be addressed
in order to improve clinical outcomes in stroke. In this review, we first discuss the structure
and function of the BBB. Next, we discuss the progress of the techniques utilized to study BBB
breakdown in in-vitro and in-vivo studies, along with biomarkers and imaging techniques in clinical
settings. Lastly, we highlight the mechanisms of stroke-induced neuroinflammation and apoptotic
process of endothelial cells causing BBB breakdown, and the potential therapeutic targets to protect
BBB integrity after stroke. Secondary products arising from stroke-induced tissue damage provide
transformation of myeloid cells such as microglia and macrophages to pro-inflammatory phenotype
followed by further BBB disruption via neuroinflammation and apoptosis of endothelial cells. In
contrast, these myeloid cells are also polarized to anti-inflammatory phenotype, repairing compromised
BBB. Therefore, therapeutic strategies to induce anti-inflammatory phenotypes of the myeloid
cells may protect BBB in order to improve clinical outcomes of stroke patients.