A Novel Transwell Blood Brain Barrier Model Using Primary Human Cells

Area of Science:

• Neuroscience
• Biomedical Engineering
• Cell Biology

Background:

• Blood-brain barrier (BBB) structural alterations and breakdown are common in diseases, leading to brain edema and unwanted substance transport.
• Effective in vitro models are crucial for studying BBB physiology, drug screening, and permeability in clinically relevant research.
• Existing models often lack the complexity of the in vivo neurovascular unit.

Purpose of the Study:

• To develop and validate a novel four-cell in vitro model of the human blood-brain barrier (BBB).
• To investigate the role of neurons in BBB integrity and response to ischemic conditions.
• To compare the efficacy of the four-cell model against simpler models for drug screening and permeability studies.

Main Methods:

• Development of a four-cell BBB model using primary human astrocytes, pericytes, brain microvascular endothelial cells (HBMECs), and neurons.
• Utilized a 3.0 μM membrane pore size for improved cell connectivity.
• Assessed BBB integrity and cell damage markers following oxygen-glucose deprivation (OGD).
• Evaluated the response to dexamethasone for barrier tightening effects.

Main Results:

• A larger membrane pore size (3.0 μM) facilitated better connections between endothelial cells, astrocytes, and pericytes.
• The four-cell model demonstrated increased permeability and cell damage markers upon OGD compared to two- and three-cell models.
• The four-cell model exhibited a faster response to dexamethasone-induced barrier tightening than simpler models.
• Neurons were shown to play a significant role in BBB maintenance and breakdown, particularly in response to ischemia.

Conclusions:

• The novel four-cell BBB model, incorporating neurons, offers a more representative in vitro system of the neurovascular unit.
• This model enhances the study of BBB physiology, response to ischemia, and drug permeability.
• The findings underscore the critical role of neurons in BBB integrity and disease pathogenesis.