BACKGROUND: Retinoic acid signaling pathways is very important in the formation pf nervous system, specialization of neurons and outgrowth of axons. The recent studies show that, retinoic acid plays an important role in the process of axonal regeneration, but few research reports its exact molecular mechanism.
OBJECTIVE: To analyze and summarize the mechanism underlying retinoic acid signaling pathways in the process of axonal regeneration.
METHODS: A computer-based online research was conducted among the VIP, CNKI, PubMed, BioMed Centeral, Springer, The Free Medical Journals, EBSCO and Foreign Journals Integration System between January 2000 and December 2013, with the key words of “retinoic acid, the central nervous system, nerve damage, axon regeneration, and mechanism” in Chinese and English. A total of 43 studies addressing the molecular mechanism of retinoic acid in axonal regeneration were screened. According to the supplementary documents, another five references were added. Repetitive research and atypical reports were excluded.
RESULTS AND CONCLUSION: Following acute central nervous system injury, axonal regeneration and functional recovery are extremely limited. For proper functionality following injury, axons must regrow, reinnervate their targets, and remyelinate their axons. When the central nervous system injuries occur, retinoic acid signaling pathways express transcription factor retinoic acid receptor β2 to induce axonal regeneration following injury; in dorsal root ganglion neurons, cAMP levels are greatly increased by lentiviral retinoic acid receptor β2 expression and contribute to neurite outgrowth. More recently, retinoic acid-retinoic acid receptor β2 pathways directly transcriptionally repress a member of the inhibitory Nogo receptor complex, Lingo-1, under an axonal growth inhibitory environment in vitro as well as following spinal cord injury in vivo. Through these molecular mechanisms, retinoic acid signaling pathways play its important role in the process of axonal regeneration.