title: TrkB-T1 receptors on Muller cells play critical role in brain-derived neurotrophic factor-mediated photoreceptor protection against phototoxicity.
abstract: OBJECTIVE
  To determine how brain-derived neurotrophic factor (BDNF) protects photoreceptors against phototoxicity.
  
  
  METHODS
  Iris pigment epithelial cells (IPE) that were transduced with different concentrations of adeno-associated virus (AAV) mediated BDNF (AAV-BDNF-IPE) were transplanted into the subretinal space of rats. We also injected small interfering RNAs (siRNAs) for TrkB, a BDNF receptor. The rats were exposed to continuous light to induce phototoxicity. We examined the expression of TrkB in the retina by Western blot and immunohistochemistry.
  
  
  RESULTS
  Significant photoreceptor protection was detected when more than 1 x 10(7) capsids/ml AAV-BDNF was transplanted. An intravitreal injection of siRNAs showed that the photoreceptor protection by AAV-BDNF-IPE was reduced by injecting the siRNA of TrkB-T1, one of the TrkB isoforms. TrkB-T1 was slightly upregulated by Western blot, and one of the cells that upregulated TrkB-T1 was Muller cells by immunohistochemistry.
  
  
  CONCLUSIONS
  We conclude that Muller cells are one of the cells responsible for the expression of TrkBs, and TrkB-T1 may play a role in the protection of photoreceptors against phototoxicity.
authors.affiliation: Division of Clinical Cell Therapy, Center for Translational and Advanced Animal Research, Miyagi, Japan.
authors.forename: Takae
authors.initials: T
authors.lastname: Saito
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Abe
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Wakusawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Sato
authors.forename: Harunobu
authors.initials: H
authors.lastname: Asai
authors.forename: Yumi
authors.initials: Y
authors.lastname: Tokita-Ishikawa
authors.forename: Kohji
authors.initials: K
authors.lastname: Nishida
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000502:physiology*; D017690:Cell Transplantation; D000229:Dependovirus / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors; D007150:Immunohistochemistry; D007498:Iris / Q000166:cytology; D008027:Light / Q000009:adverse effects; D009457:Neuroglia / Q000378:metabolism*; D020419:Photoreceptor Cells, Vertebrate / Q000528:radiation effects*; D010857:Pigment Epithelium of Eye / Q000378:metabolism / Q000637:transplantation; D034741:RNA, Small Interfering / Q000502:physiology; D011833:Radiation Injuries, Experimental / Q000209:etiology / Q000517:prevention & control*; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000502:physiology*; D012162:Retinal Degeneration / Q000209:etiology / Q000517:prevention & control*; D014162:Transfection
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D034741:RNA, Small Interfering; D020813:Receptor, trkB