Schumacher M, Guennoun R, Mercier G, Désarnaud F, Lacor P, Bénavides J, Ferzaz B, Robert F, Baulieu E E
INSERM U488, 80 rue du Général Leclerc, 94276, Le Kremlin-Bicêtre, France.
Brain Res Brain Res Rev. 2001 Nov;37(1-3):343-59. doi: 10.1016/s0165-0173(01)00139-4.
Progesterone is synthesized in the nervous system by neurons and glial cells. Because of their simple structure, plasticity and capacity of regeneration, peripheral nerves are particularly well suited for studying the biosynthesis, mechanisms of action and effects of the hormone. Schwann cells, the myelinating glial cells in the peripheral nervous system, synthesize progesterone in response to a diffusible neuronal signal. In peripheral nerves, the local synthesis of progesterone plays an important role in the formation of myelin sheaths. This has been shown in vivo, after cryolesion of the mouse sciatic nerve, and in vitro, in cocultures of Schwann cells and sensory neurons. Schwann cells also express an intracellular receptor for progesterone, which thus functions as an autocrine signalling molecule. Progesterone may promote myelination by activating the expression of genes coding for transcription factors (Krox-20) and/or for myelin proteins (P0, PMP22). Recently, it has been proposed that progesterone may indirectly regulate myelin formation by influencing gene expression in neurons. Steroid hormones also influence the proliferation of Schwann cells: estradiol becomes a potent mitogen for Schwann cells when levels of cAMP are elevated and glucocorticosteroids have been shown to increase the mitogenic effects of peptide growth factors.
孕酮由神经元和神经胶质细胞在神经系统中合成。由于其结构简单、可塑性强以及具有再生能力，外周神经特别适合用于研究该激素的生物合成、作用机制和效应。雪旺细胞是外周神经系统中的髓鞘形成神经胶质细胞，它会响应一种可扩散的神经元信号合成孕酮。在周围神经中，孕酮的局部合成在髓鞘形成过程中起着重要作用。这一点已在小鼠坐骨神经冷冻损伤后的体内实验以及雪旺细胞与感觉神经元共培养的体外实验中得到证实。雪旺细胞还表达一种孕酮细胞内受体，因此孕酮可作为一种自分泌信号分子发挥作用。孕酮可能通过激活编码转录因子（Krox - 20）和/或髓鞘蛋白（P0、PMP22）的基因表达来促进髓鞘形成。最近，有人提出孕酮可能通过影响神经元中的基因表达来间接调节髓鞘形成。类固醇激素也会影响雪旺细胞的增殖：当环磷酸腺苷（cAMP）水平升高时，雌二醇会成为雪旺细胞的一种强效促有丝分裂原，并且已表明糖皮质激素会增强肽生长因子的促有丝分裂作用。
