Neurosteroids and Translocator Protein (TSPO) in neuroinflammation

Neurosteroids have a crucial role in physiological intrinsic regulations of the Central Nervous System functions. They are derived from peripheral steroidogenic sources and from the de novo neurosteroidogenic capacity of brain cells. Significant alterations of neurosteroid levels have been frequently observed in neuroinflammation and neurodegenerative diseases. Such level fluctuations may be useful for both diagnosis and treatment of these pathological conditions. Beyond steroid administration, enhancing the endogenous production by Translocator Protein (TSPO) targeting has been proposed to restore these altered pathological levels. However, the neurosteroid quantification and the prediction of their final effects are often troublesome, sometimes controversial and context dependent, due to the complexity of neurosteroid biosynthetic pathway and to the low produced amounts. The aim of this review is to report recent advances, and technical limitations, in neurosteroid-related strategies against neuroinflammation.