Neuroscience 2002 Abstract
| Presentation Number: | 236.12 |
|---|---|
| Abstract Title: | Apoptosis in the Developing Retina: Gap Junctions Contribute to Bystander Cell Killing. |
| Authors: |
Cusato, K.*1,2
; Bosco, A.2,5
; Rozental, R.1
; Guimaraes, C. A.2
; Reese, B. E.3,4
; Spray, D. C.1
; Linden, R.2
1Neuroscience, AECOM, Bronx, NY 2IBCCF, UFRJ, Rio de Janeiro, Brazil 3Psychology, UCSB, Santa Barbara, CA 4NRI, UCSB, Santa Barbara, CA 5CABM, UMDNJ, Piscataway, NJ |
| Primary Theme and Topics |
Development - Development of Sensory, Motor and Limbic Systems -- Visual system |
| Secondary Theme and Topics | Synaptic Transmission and Excitability<br />- Ion Channels<br />-- Ih and connexins |
| Session: |
236. Development of sensory, motor and limbic systems: retinal development Poster |
| Presentation Time: | Monday, November 4, 2002 11:00 AM-12:00 PM |
| Location: | Hall A2-B3 B-70 |
| Keywords: | CELL DEATH, CYTOCHROME C |
Apoptotic neuronal loss in the postnatal mouse retina (P5 and P8) occurs in spatially coherent clusters (Cusato and Reese, 2000, SFN Abs. 119.12), suggesting bystander cell killing. To examine whether gap junctions contribute to the spread of cell death, we induced apoptosis in P13 rat retina by scrapeloading with Cytochrome c (Cc) in the presence of rhodamine dextran (RD, to identify Cc loaded cells). Control retinas were scrapeloaded with RD only. Retinas were maintained in vitro for 1 hour, fixed, sectioned, DAPI stained, and pyknotic cells were counted. While only 1.5% of control scrapeloaded cells showed apoptotic morphology, 97% of Cc scrapeloaded cells were pyknotic. Moreover, in Cc retinas, many cells were pyknotic that were not RD-labeled. For Cc, the bystander index (the proportion of pyknotic cells not RD labeled) was 0.67, which was significantly reduced by the gap junction inhibitors octanol, carbenoxolone, and SNAP. Because neither Cc and RD are gap junction-permeant, experiments with biotinylated Cc show colocalization of Cc and RD in cells, and the bystander effect was reduced dramatically by gap junction inhibitors, we hypothesize that Cc loading induces a gap junction-permeant apoptotic signal that mediates bystander cell death. Preliminary experiments, in which retinal cells were co-injected with Cc and a gap junction-permeant dye, indicate that bystander killing extends to coupled cells. These data may provide a mechanistic explanation for clustering of apoptotic cells seen in retinal development.
Supported by NIH (KC: HL07675, DCS: MH65495), CNPQ, FAPERJ, Pronex-MCT (RL)
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2002 Neuroscience Meeting Planner. Orlando, FL: Society for Neuroscience, 2002. Online.
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