The Journal of Neuroscience, May 15, 2003, 23(10):4023-4028
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BRIEF COMMUNICATION
Apoptotic Death of
Cells after Optic Nerve Transection in Adult Cats
Takuji Kurimoto,1,2
Tomomitsu Miyoshi,1
Akira Suzuki,1
Toru Yakura,1
Masami Watanabe,3
Osamu Mimura,2 and
Yutaka Fukuda1
1Department of Physiology and Biosignaling, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan,
2Department of Ophthalmology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan, and
3Department of Physiology, Institute for Developmental Research, Kasugai, Aichi 480-0392, Japan
We have revealed previously that the survival rate of
cells of cat retinal ganglion cells (RGCs) rapidly decreased to 29% on day 7 after optic nerve transection, whereas that of
cells slowly decreased to 64% on day 14 (Watanabe et al., 2001). The reason that
cells die more rapidly than
cells was not clear. In the present study, we tested the possibility that the rapid death of
cells is attributable to apoptosis, as shown for some axotomized RGCs in rats. The following results were obtained. First, 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
cells. Secondly, the proportion of pyknotic cells was the highest in the area centralis (AC), in which
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
cells on day 7 was significantly enhanced, whereas no such survival-promoting effect was obtained in axotomized
cells. Taken together, these results suggest that the rapid death of axotomized
cells is attributable mainly to apoptosis, which is mediated by caspase 3.
Key words: adult cat; retinal ganglion cells;
cells; optic nerve transection; apoptosis; caspase 3 inhibitor
Received Sep. 25, 2002;
revised Mar. 3, 2003;
accepted Mar. 5, 2003.