Title | Activation of MAP2K signaling by genetic engineering or HF-rTMS promotes corticospinal axon sprouting and functional regeneration. |
Publication Type | Journal Article |
Year of Publication | 2023 |
Authors | Boato F, Guan X, Zhu Y, Ryu Y, Voutounou M, Rynne C, Freschlin CR, Zumbo P, Betel D, Matho K, Makarov SN, Wu Z, Son Y-J, Nummenmaa A, Huang JZ, Edwards DJ, Zhong J |
Journal | Sci Transl Med |
Volume | 15 |
Issue | 677 |
Pagination | eabq6885 |
Date Published | 2023 Jan 04 |
ISSN | 1946-6242 |
Keywords | Animals, Axons, Genetic Engineering, Mice, Nerve Regeneration, Proto-Oncogene Proteins B-raf, Pyramidal Tracts, Recovery of Function, Spinal Cord Injuries, Transcranial Magnetic Stimulation, Transcription Factors, Zebrafish |
Abstract | Facilitating axon regeneration in the injured central nervous system remains a challenging task. RAF-MAP2K signaling plays a key role in axon elongation during nervous system development. Here, we show that conditional expression of a constitutively kinase-activated BRAF in mature corticospinal neurons elicited the expression of a set of transcription factors previously implicated in the regeneration of zebrafish retinal ganglion cell axons and promoted regeneration and sprouting of corticospinal tract (CST) axons after spinal cord injury in mice. Newly sprouting axon collaterals formed synaptic connections with spinal interneurons, resulting in improved recovery of motor function. Noninvasive suprathreshold high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) activated the BRAF canonical downstream effectors MAP2K1/2 and modulated the expression of a set of regeneration-related transcription factors in a pattern consistent with that induced by BRAF activation. HF-rTMS enabled CST axon regeneration and sprouting, which was abolished in MAP2K1/2 conditional null mice. These data collectively demonstrate a central role of MAP2K signaling in augmenting the growth capacity of mature corticospinal neurons and suggest that HF-rTMS might have potential for treating spinal cord injury by modulating MAP2K signaling. |
DOI | 10.1126/scitranslmed.abq6885 |
Alternate Journal | Sci Transl Med |
PubMed ID | 36599003 |
Grant List | R01 NS099568 / NS / NINDS NIH HHS / United States R01 MH111829 / MH / NIMH NIH HHS / United States R00 EB015445 / EB / NIBIB NIH HHS / United States P41 EB030006 / EB / NIBIB NIH HHS / United States |