PMID- 17640634
OWN - NLM
STAT- MEDLINE
DCOM- 20071109
LR  - 20091119
IS  - 0014-4835 (Print)
IS  - 0014-4835 (Linking)
VI  - 85
IP  - 3
DP  - 2007 Sep
TI  - Temporal and spatial differences in expression of TrkB isoforms in rat retina 
      during constant light exposure.
PG  - 346-55
AB  - Brain-derived neurotrophic factor (BDNF) has been reported to rescue neuroretinal 
      cells under different toxic conditions. These cells include not only those 
      expressing BDNF receptors (TrkB) but also those not expressing TrkB including 
      photoreceptors. The purpose of this study was to determine the retinal sites at 
      which BDNF and TrkB isoforms are expressed after different durations of 
      continuous light exposure, and to compare these sites with those of 
      TUNEL-positive cells in the same retina. Sprague-Dawley rats were exposed to 
      continuous light for different durations. The expressions of BDNF and TrkB 
      isoforms, TrkB-FL and TrkB-T1, were determined by Western blot analysis, 
      real-time PCR, immunohistochemistry, and in situ hybridization before and after 
      the light exposure. The number of TUNEL-positive cells reached a maximum at 48 to 
      72h after light exposure. The degree of up-regulation of the TrkB-T1 gene was 
      significantly higher than that in normal control eyes at 24h by real-time PCR. 
      Immunohistochemistry showed that TrkB-FL-positive cells were detected in all 
      retinal layers except the outer nuclear layer (ONL), photoreceptor cells, and 
      retinal pigment epithelium (RPE). The number of TrkB-FL-positive cells in the IPL 
      was transiently decreased at 6h, and was increased on the processes of the 
      Mueller cells in the ONL after 48h. TrkB-T1 was expressed in the INL, OPL, and 
      RPE, and was up-regulated on the soma of Mueller cells after 24h. In situ 
      hybridization showed that the expression of the TrkB-FL gene was up-regulated in 
      the INL after 48h when the number of TUNEL-positive cells was at its peak. The 
      TrkB-T1 gene was up-regulated before or just prior to the appearance of 
      TUNEL-positive cells. These results suggest that BDNF transduces the signals 
      using appropriate receptor isoforms that are expressed temporally and spatially 
      differentially on Mueller cells during light-induced retinal degeneration.
FAU - Asai, Nobuharu
AU  - Asai N
AD  - Division of Clinical Cell Therapy, Center for Translational and Advanced Animal 
      Research, Tohoku University, Graduate School of Medicine, 1-1 Seiryoumachi, 
      Aobaku, Sendai, Miyagi 980-8574, Japan.
FAU - Abe, Toshiaki
AU  - Abe T
FAU - Saito, Takae
AU  - Saito T
FAU - Sato, Hajime
AU  - Sato H
FAU - Ishiguro, Sei-Ichi
AU  - Ishiguro S
FAU - Nishida, Kohji
AU  - Nishida K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20070615
PL  - England
TA  - Exp Eye Res
JT  - Experimental eye research
JID - 0370707
RN  - 0 (Brain-Derived Neurotrophic Factor)
RN  - 0 (Eye Proteins)
RN  - 0 (Protein Isoforms)
RN  - EC 2.7.10.1 (Receptor, trkB)
SB  - IM
MH  - Animals
MH  - Apoptosis/radiation effects
MH  - Brain-Derived Neurotrophic Factor/genetics/metabolism
MH  - Eye Proteins/genetics/*metabolism
MH  - Gene Expression Regulation/radiation effects
MH  - Immunoenzyme Techniques
MH  - *Light
MH  - Male
MH  - Photic Stimulation/methods
MH  - Photoreceptor Cells, Vertebrate/radiation effects
MH  - Protein Isoforms/genetics/metabolism
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Receptor, trkB/genetics/*metabolism
MH  - Retina/*metabolism/*radiation effects
MH  - Reverse Transcriptase Polymerase Chain Reaction/methods
EDAT- 2007/07/21 09:00
MHDA- 2007/11/10 09:00
CRDT- 2007/07/21 09:00
PHST- 2007/02/08 00:00 [received]
PHST- 2007/05/12 00:00 [revised]
PHST- 2007/05/30 00:00 [accepted]
PHST- 2007/07/21 09:00 [pubmed]
PHST- 2007/11/10 09:00 [medline]
PHST- 2007/07/21 09:00 [entrez]
AID - S0014-4835(07)00157-1 [pii]
AID - 10.1016/j.exer.2007.05.010 [doi]
PST - ppublish
SO  - Exp Eye Res. 2007 Sep;85(3):346-55. doi: 10.1016/j.exer.2007.05.010. Epub 2007 
      Jun 15.