The brain is the most complex organ in the human body. Neurons transmit information to nerve cells, muscles, and glands which control and coordinate every systemic function within the body. The brain is essentially a control system for a person’s sense of thought, touch, smell, taste, sight, movement, and memory along with so much more. This complex organ is also extremely fragile and requires its own defense system which is called the Blood Brain Barrier.
The Blood Brain Barrier is the term used to describe the thick lining of cerebral microvasculature which protects the brain from harm. The vessels and Blood Brain Barrier endothelial cells can tightly regulate the movement of molecules, ions, and cells through the barrier from blood and the central nervous system. The heavily restrictive barrier is responsible for keeping the Central Nervous System in homeostasis. This ensures proper neuronal function and allows for protection from toxins, pathogens, inflammation, injury, and disease. The main function of the Blood Brain Barrier is to protect the most complex and important organ in the body, the brain. The barrier protects the brain by blocking the circulating toxins and pathogens while, at the same time, allowing essential nutrients to pass through.
Although this defense system may seem ideal, there can be caveats in any mechanism. Neurological disorders such as Parkinson’s Disease and Huntington’s Disease are linked to defective blood brain barriers. In these cases, the barrier is doing too much and keeping out the crucial nutrients that are needed for healthy brain activity.
About Blood Brain Barrier Models
A working Blood Brain Barrier model is dependent on development of the barrier membrane. It must be made of specialized endothelial cells that can modulate impermeability, are immune transporters, and control immune cell trafficking. In vitro models allow scientists to study the mechanisms on human and animal tissue. Most models are conducted by isolating and culturing primary brain endothelial cells or using an immortalized version of the cell line. Primary cells are beneficial because they produce high TEER and low permeability, but primary human brain endothelial cells are difficult to obtain and must be collected from a living patient to provide such TEER values. Immortalized cell lines are beneficial for their ease of use, dependability, and expression of tight junctions but these cells do not typically result in suitable TEER and may not form the strongest barrier.
A newer method uses human induced Pluripotent Stem Cells (iPSC) which when derived into induced Brain Endothelial Cells allow for high TEER values, functional transporters, tight junctions, and low permeability when used as a Blood Brain Barrier. The use of iPSC’s allows for less invasive procedures for collection, the cells can be vastly expanded, and genetic alterations to these cells can allow for study of gene function and disease mutations.
Researchers in Visikol’s Pharmacology and Drug Discovery division are skilled in toxicity assessment and screening in two dimensional and three dimensional cellular based assays. If you are interested in learning more about this technique or any of the other many new research opportunities at Visikol, please reach out to our team. We are always interested in working together with our clients as a team to develop customized assays to best suit their needs.
Resources
Erickson, M. A., Wilson, M. L., & Banks, W. A. (2020, March 30). In vitro modeling of blood–brain barrier and interface functions in neuroimmune communication – fluids and barriers of the CNS. BioMed Central. Retrieved April 4, 2022, from https://fluidsbarrierscns.biomedcentral.com/articles/10.1186/s12987-020-00187-3#:~:text=The%205%20axes%20are%3A%20(1,BBB%20secretions%20of%20immunoactive%20substances.
Holek, I. M. (n.d.). What is the blood-brain barrier & why is it so important? Cbchealth. Retrieved April 4, 2022, from https://cbchealth.de/en/blood-brain-barrier-importance/