Repetitive Transcranial Magnetic Stimulation Promotes Neural Stem CellProliferation and Differentiation after Intracerebral Hemorrhage in Mice*

摘要

Repetitive transcranial magnetic stimulation (rTMS) is a physical treatment appliedduring recovery after intracerebral hemorrhage (ICH). With in vivo and in vitro assays,the present study sought to investigate how rTMS influences neural stem cells (NSCs) afterICH and the possible mechanism. Following a collagenase-induced ICH, adult male C57BL/6 Jmice were subjected to rTMS treatment every 24 h for 5 days using the followingparameters: frequency, 10 Hz; duration, 2 s; wait time, 5.5 s; 960 trains (500 µV/div, 5ms/div, default setting). Brain water content and neurobehavioral score were assessed atdays 1, 3, and 5 after ICH. The proliferation and differentiation of NSCs were observedusing immunofluorescence staining for Nestin, Ki-67, DCX, and GFAP on day 3 after ICH, andrTMS treatment with the same parameters was applied to NSCs in vitro. We found that rTMSsignificantly reduced brain edema and alleviated neural functional deficits. The mice thatunderwent ICH recovered faster after rTMS treatment, with apparent proliferation andneuronal differentiation of NSCs and attenuation of glial differentiation and GFAPaggregation. Accordingly, proliferation and neuronal differentiation of isolated NSCs werepromoted, while glial differentiation was reduced. In addition, microarray analysis,western blotting assays, and calcium imaging were applied to initially investigate thepotential mechanism. Bioinformatics showed that the positive effect of rTMS on NSCs afterICH was largely related to the MAPK signaling pathway, which might be a potential hubsignaling pathway under the complex effect exerted by rTMS. The results of the microarraydata analysis also revealed that Ca might be the connection between physicaltreatment and the MAPK signaling pathway. These predictions were further identified bywestern blotting analysis and calcium imaging. Taken together, our findings showed thatrTMS after ICH exhibited a restorative effect by enhancing the proliferation and neuronaldifferentiation of NSCs, potentially through the MAPK signaling pathway.