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Abstract #9734 Published in IGR 5-3
Apoptotic death of β cells after optic nerve transection in adult cats
Kurimoto T; Miyoshi T; Suzuki A; Yakura T; Watanabe M; Mimura O; Fukuda YJournal of Neuroscience 2003; 23: 4023-4028
The authors have previously revealed that the survival rate of β cells of cat retinal ganglion cells (RGCs) rapidly decreased to 29% on day 7 after optic nerve transection, whereas that of α cells slowly decreased to 64% on day 14. The reason that β cells die more rapidly than α cells was not clear. In the present study, they tested the possibility that the rapid death of β cells is attributable to apoptosis, as shown for some axotomized RGCs in rats. The following results were obtained. Firstly, the proportion of pyknotic cells in Nissl-stained cat retinas started to increase sharply starting on day 4 and reached a peak on day 6 after optic nerve transection. The time course of occurrence of pyknotic cells corresponded well with that of the rapid death of axotomized β cells. Secondly, the proportion of pyknotic cells was the highest in the area centralis (AC), in which β cells are densely distributed. The preferential death of axotomized RGCs in the AC was also confirmed by terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling staining in cross-sections. Thirdly, after the intravitreal injection of caspase 3 inhibitor (z-DEVD-cmk), the survival of axotomized β cells on day 7 was significantly enhanced, whereas no such survival-promoting effect was obtained in axotomized α cells. Taken together, these results suggest that the rapid death of axotomized β cells is mainly attributable to apoptosis, which is mediated by caspase 3.
Dr. T. Miyoshi, Department of Physiology and Biosignaling, Graduate School of Medicine, Osaka University, AS, 2-2 Yamadaoka, Suita City, Osaka 565-0871, Japan
Classification:
5 Experimental glaucoma; animal models
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
3.6 Cellular biology (Part of: 3 Laboratory methods)
