Euido Nishijima, Sari Honda, Yuta Kitamura, Kazuhiko Namekata, Atsuko Kimura, Xiaoli Guo, Yuriko Azuchi, Chikako Harada, Akira Murakami, Akira Matsuda, Tadashi Nakano, Luis F Parada, Takayuki Harada
Molecular therapy : the journal of the American Society of Gene Therapy 31(3) 810-824 2022年12月5日 査読有り筆頭著者
Activation of neurotrophic factor signaling is a promising therapy for neurodegeneration. However, the transient nature of ligand-dependent activation limits its effectiveness. In this study, we solved this problem by inventing a system that forces membrane localization of the intracellular domain of tropomyosin receptor kinase B (iTrkB), which results in constitutive activation without ligands. Our system overcomes the small size limitation of the genome packaging in adeno-associated virus (AAV) and allows high expression of the transgene. Using AAV-mediated gene therapy in the eyes, we demonstrate that iTrkB expression enhances neuroprotection in mouse models of glaucoma and stimulates robust axon regeneration after optic nerve injury. In addition, iTrkB expression in the retina was also effective in an optic tract transection model, in which the injury site is near the superior colliculus. Regenerating axons successfully formed pathways to their brain targets, resulting in partial recovery of visual behavior. Our system may also be applicable to other trophic factor signaling pathways and lead to a significant advance in the field of gene therapy for neurotrauma and neurodegenerative disorders, including glaucoma.