In vitro models to study the blood brain barrier

Area of Science:

• Neuroscience
• Physiology
• Biochemistry

Background:

• The blood-brain barrier (BBB) regulates chemical transport into and out of the brain.
• It comprises brain capillaries with tight junctions (physical barrier) and efflux transporters (chemical barrier).
• BBB permeability is compensated by nutrient transporters crucial for brain function.

Purpose of the Study:

• To compare the utility of cell culture models and isolated microvessels for studying the BBB.
• To propose an integrated approach for studying BBB transport mechanisms.

Main Methods:

• Utilized cell culture models with brain endothelial cells (rat, pig, cow), sometimes co-cultured with astrocytes.
• Employed isolated brain microvessels directly from the brain.
• Proposed a sequential approach: verify transport in microvessels, then study mechanisms in cell culture.

Main Results:

• Cell culture models are easier and cheaper but do not fully replicate the in vivo BBB's tight barrier or all transporters.
• Isolated microvessels express all in vivo transporters but are laborious, require animals, and have a shorter lifespan.
• The proposed approach combines the strengths of both methods.

Conclusions:

• Neither cell culture models nor isolated microvessels perfectly replicate the in vivo blood-brain barrier.
• An integrated approach using both methods can provide a more comprehensive understanding of BBB transport.
• This strategy allows initial verification in a more representative system (microvessels) followed by detailed mechanistic studies (cell culture).