title: Restoration of the majority of the visual spectrum by using modified Volvox channelrhodopsin-1.
abstract: We previously showed that blind rats whose vision was restored by gene transfer of Chlamydomonas channelrhodopsin-2 (ChR2) could only detect wavelengths less than 540 nm because of the action spectrum of the transgene product. Volvox-derived channelrhodopsin-1, VChR1, has a broader spectrum than ChR2. However, the VChR1 protein was mainly localized in the cytoplasm and showed weak ion channel properties when the VChR1 gene was transfected into HEK293 cells. We generated modified Volvox channelrhodopsin-1 (mVChR1), which is a chimera of Volvox channelrhodopsin-1 and Chlamydomonas channelrhodopsin-1 and demonstrated increased plasma membrane integration and dramatic improvement in its channel properties. Under whole-cell patch clamp, mVChR1-expressing cells showed a photo-induced current upon stimulation at 468-640 nm. The evoked currents in mVChR1-expressing cells were ~30 times larger than those in VChR1-expressing cells. Genetically, blind rats expressing mVChR1 via an adeno-associated virus vector regained their visual responses to light with wavelengths between 468 and 640 nm and their recovered visual responses were maintained for a year. Thus, mVChR1 is a candidate gene for gene therapy for restoring vision, and gene delivery of mVChR1 may provide blind patients access to the majority of the visible light spectrum.
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan; Clinical Research, Innovation and Education Center, Tohoku University Hospital, Sendai, Miyagi, Japan. Electronic address: htomita@iwate-u.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tomita
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Sugano
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: Namie
authors.initials: N
authors.lastname: Murayama
authors.affiliation: Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Ozaki
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Nishiyama
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: Kitako
authors.initials: K
authors.lastname: Tabata
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Saito
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Tamai
mesh_terms: D000818:Animals; D001766:Blindness / Q000378:metabolism / Q000628:therapy*; D002696:Chlamydomonas / Q000235:genetics; D000229:Dependovirus / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000627:therapeutic use; D057809:HEK293 Cells; D006801:Humans; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000503:physiopathology*; D012243:Rhodopsin / Q000235:genetics / Q000378:metabolism*; D044446:Volvox / Q000235:genetics*
chemical_list: D011993:Recombinant Fusion Proteins; D012243:Rhodopsin