<italic>In situ</italic> neuroregeneration: frontiers and therapeutic prospects

Neuroregeneration in the adult mammalian central nervous system (CNS) is a long unresolved problem over the past centuries. Previous stem cell research has shown some promise in neural regeneration, but also encountered many challenges. In situ neuroregeneration technology is a newly emerged technology that takes advantage of widespread endogenous glial cells to regenerate new neurons in injured areas with neuronal loss. By overexpressing neural transcription factors or knocking down certain factors, glial cells can be directly converted into functional neurons in situ, avoiding transplantation of external cell. This review article summarizes current progress and potential applications of in situ glia-to-neuron conversion technology in the treatment of stroke, Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, retinal disease, and spinal cord injury. Although still in its infant stage with certain limitations, we have already demonstrated the feasibility of in situ neuroregeneration in a non-human primate model, paving a potential way toward future clinical trials.