Protective Effects of Neurotrophic Factors on Tumor Necrosis Factor-related Apoptosis-inducing Ligand (TRAIL)-mediated Apoptosis of Murine Adrenal Chromaffin Cell Line tsAM5D*
- Department of Analytical Neurobiology, Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468-8503, Japan
- 1 To whom correspondence should be addressed. Tel.: 81-52-832-1781 (ext. 330); Fax: 81-52-834-8090; E-mail: nkaneda{at}ccmfs.meijo-u.ac.jp.
Abstract
We previously established the murine adrenal chromaffin cell line tsAM5D, which was immortalized with the temperature-sensitive simian virus 40 large T-antigen. tsAM5D cells have the capacity to differentiate into neuron-like cells in response to neurotrophic factors when the culture temperature is shifted from 33 to 39 °C. In this model system, the temperature shift in the absence of neurotrophic factors led to cell death. Hoechst staining analysis revealed that typical apoptotic nuclei appeared in a time-dependent manner after the temperature shift. Upon shifting to 39 °C, the degradation of T-antigen was accompanied by the transcriptional activation of p53 protein. Among the p53 target genes, death receptor 5 (DR5), which is the receptor for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), showed the highest level of induction. Interestingly, TRAIL-neutralizing antibody protected tsAM5D cells from the temperature shift-induced apoptotic cell death by blocking the activation of caspase-8 and -3, indicating the involvement of TRAIL-mediated death signaling in the temperature shift-induced apoptosis. Glial cell line-derived neurotrophic factor (GDNF) inhibited the TRAIL-mediated activation of caspase-8 in tsAM5D cells exposed to 39 °C and cooperated with basic fibroblast growth factor and ciliary neurotrophic factor. Interestingly, the temperature shift induced oligomerization of DR5, which is the earliest process necessary for transduction of the death signal. This oligomerization was inhibited by treatment with GDNF plus ciliary neurotrophic factor but not by that with GDNF alone or GDNF plus basic fibroblast growth factor. These results are discussed with respect to the intracellular mechanism underlying the protective function of neurotrophic factors against TRAIL-mediated death signaling.
Footnotes
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↵2 The abbreviations used are: tsSV40T, temperature-sensitive tsA58 mutant of SV40T; DR5, death receptor 5; TRAIL, tumor necrosis factor-related apoptosis-inducing ligand; GDNF, glial cell line-derived neurotrophic factor; bFGF, basic fibroblast growth factor; CNTF, ciliary neurotrophic factor; SV40T, simian virus 40 large T-antigen; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; PI3K, phosphatidylinositol 3-kinase; DISC, death-inducing signaling complex; Z, benzyloxycarbonyl; fmk, fluoromethyl ketone; PBS, phosphate-buffered saline; RT, reverse transcription; TNF, tumor necrosis factor; MTS tetrazolium, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2(4-sulfophenyl)-2H-tetrazolium.
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↵3 T. Murata, M. Tsuboi, K. Hikita, and N. Kaneda, unpublished data.
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↵* This work was supported in part by Scientific Research Grants 15790055 and High-Tech Research Center Project from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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The on-line version of this article (available at http://www.jbc.org) contains Videos 1–7.
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- Received March 20, 2006.
- Revision received June 12, 2006.
- The American Society for Biochemistry and Molecular Biology, Inc.
