Effect of retinoic acid on the neurovascular unit: A review.

Retinoic acid is a metabolic product derived from vitamin A, acting at a nuclear level to maintain the proper transcriptional activity. Moreover, this molecule contributes to the development and maturation of the cerebral vascular system, playing a pivotal role in development and maintenance of neurovascular unit integrity. This physiological structure is comprised of glial cells, vascular cells, and neurons, ensuring the correct function of the blood-brain barrier and, at last instance, the homeostasis of the central nervous system. Therefore, retinoic acid ensures the physiological structure integrity of the neurovascular unit, decreasing the development of neurological disorders. Furthermore, retinoic acid can modulate the physiological function of the neurovascular unit cells, which is crucial to the maintenance of this physiological structure. The deletion of this molecule leads to the development of neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, Parkinson's disease. In addition, impaired signaling of this molecule contributes to a worse prognosis in the recovery after ischemic stroke. This review characterizes the cellular components that constitute the neurovascular unit and analyzes the effect of retinoic acid on these cellular components that, in a coordinated manner, are responsible for homeostasis of the central nervous system. Through this description, it seems apparent that retinoic acid administration might be an essential pharmacological tool in the near future.