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Neurosteroids: The StAR Protein in the Brain
Author(s) -
Sierra A.
Publication year - 2004
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/j.1365-2826.2004.01226.x
Subject(s) - steroidogenic acute regulatory protein , neuroactive steroid , cholesterol side chain cleavage enzyme , medicine , endocrinology , neurogenesis , biology , hormone , mitochondrion , sterol , microbiology and biotechnology , cholesterol , cytochrome p450 , biochemistry , messenger rna , receptor , metabolism , gene , gabaa receptor
The nervous system is a well‐known target for steroid hormones, as these hormones regulate brain functions that include neuronal survival and differentiation, myelination, neurogenesis, plasticity and repair after injury. Furthermore, the brain is also a steroidogenic tissue because it possesses the enzymes required to metabolize the common precursor, cholesterol, into steroids, named ‘neurosteroids’. The rate‐limiting step in the synthesis of steroid hormones is the access of cholesterol, accumulated in the outer mitochondrial membrane, to the first steroidogenic enzyme, P450scc (cholesterol side‐chain cleavage enzyme), located in the inner mitochondrial membrane. In the ovary and the adrenal gland, which comprise classic steroidogenic tissues, this process requires the steroidogenic acute regulatory protein (StAR) to facilitate the shuttle of cholesterol through the intermembrane space. The mechanism used by the brain to regulate the first stage of steroidogenesis remains unknown. Recently, several groups have investigated the potential presence of StAR in the nervous tissue and have concluded that StAR is widely expressed throughout the brain, although restricted to specific cell populations. New results concerning localization, regulation and possible functions of StAR in the brain are discussed.