megakaryocyte is the type of cell that forms the blood brain barrier.
megakaryocyte is the type of cell that forms the blood brain barrier.
which type of cell forms the blood brain barrier?
megakaryocyte
cytokines are a class of proteins that regulates inflammation, cell signaling, and various cell processes such as growth and survival. chemokines are a subset of cytokines that regulate cell migration, such as attracting immune cells to a site of infection or injury. various cell types in the brain may produce cytokines and chemokines such as microglia, astrocytes, endothelial cells, and other glial cells. physiologically, chemokines and cytokines function as neuromodulators that regulate inflammation and development. in the healthy brain, cells secrete cytokines to produce a local inflammatory environment to recruit microglia and clear the infection or injury. however, in neuroinflammation, cells may have sustained release of cytokines and chemokines which may compromise the blood–brain barrier. peripheral immune cells are called to the site of injury via these cytokines and may now migrate across the compromised blood brain barrier into the brain. common cytokines produced in response to brain injury include: interleukin-6 (il-6), which is produced during astrogliosis, and interleukin-1 beta (il-1β) and tumor necrosis factor alpha (tnf-α), which can induce neuronal cytotoxicity. although the pro-inflammatory cytokines may cause cell death and secondary tissue damage, they are necessary to repair the damaged tissue. for example, tnf-α causes neurotoxicity at early stages of neuroinflammation, but contributes to tissue growth at later stages of inflammation.
neuroinflammation
drugs diffuse through capillary walls in the same manner as endogenous molecules. one of the most important examples of this is drug diffusion across the blood brain barrier. the blood brain barrier consists of a bed of continuous capillaries. typically only small hydrophobic molecules are able to diffuse across the blood brain barrier. this makes it very difficult to get drugs into the brain without invasively administering them directly into the brain. one possible solution is the utilization of nanoparticles. nanoparticles are synthesized to encapsulate a target drug. the surface of the nanoparticle, if not already hydrophobic, may have polymers attached to the surface to adjust the current polarity. ligands can also be attached to the surface of a nanoparticle to target certain receptors located within the brain. once the nanoparticle is through the blood brain barrier it releases the drug into the brain. a specific example of this solution is the delivery of anti-hiv drugs to the central nervous system by tat-conjugated nanoparticles.
surface chemistry of microvasculature