Clusterin Biogenesis Is Altered during Apoptosis in the Regressing Rat Ventral Prostate*
- Johnathan Lakins‡§,
- Steffany A. L. Bennettद,
- Jia-Hua Chen¶,
- Jennifer M. Arnold¶,
- Colm Morrissey‡‖,
- Paul Wong**,
- Jacintha O’Sullivan‡‖ and
- Martin Tenniswood‡‡
- From the ‡Adirondack Biomedical Research Institute, Lake Placid, New York 12946, the ¶Institute for Neuroscience, Carleton University, Ottawa, Ontario K1S 5B6, Canada, the **Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada, and ‖University College Dublin, Belfield, Dublin 4, Ireland
Abstract
Clusterin was first characterized as an apoptosis-associated transcript after it was identified as testosterone-repressed prostate message (TRPM-2) that is expressed in the epithelial cells of the regressing rat ventral prostate. Increases in clusterin mRNA and protein have been consistently detected in apoptotic cell death paradigms, establishing clusterin gene expression as a prominent marker of apoptotic cell loss. However, enhanced protein expression has also been reported in surviving cells. This ambiguity makes it difficult to define the contribution of clusterin to apoptosis. To address this problem, a panel of polyclonal and monoclonal antibodies were raised against the clusterin α-chain, β-chain, and mixed α/β epitopes. These antibodies detect changes in the biogenesis of clusterin during apoptosis by Western analysis and immunohistochemistry. A 42-kDa glyco/isoform of clusterin appears to be up-regulated in dying epithelial cells. This glyco/isoform is apparently generated as a result of apoptosis-induced stimulation of a normal but under-utilized, synthetic pathway. These data demonstrate that clusterin synthesized by apoptotic cells can be immunologically distinguished from clusterin synthesized by surviving cells in damaged tissue.
Footnotes
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↵* This work was supported by National Institute of Health Grant CA69233-01 (to M. T.) and grants from the Alzheimer Society of Canada (to S. A. L. B.), the Medical Research Council of Canada (to J. L.), Fondation a l’Aide des Chercheurs pour la Recherche (to J. M. A.), and Fighting Blindness (to P. W.).The costs of publication of this article were defrayed in part by the payment of page charges. The 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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↵§ Both authors contributed equally to this work.
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↵‡ To whom correspondence should be addressed: Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556. Tel.: 219-631-3372; Fax: 219-631-7413; E-mail: tenniswood.1{at}nd.edu.
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↵1 Numbering of the amino acids in rat clusterin is based on the mature protein and does not include the 21 amino acids of the signal sequence.
- Abbreviations:
- PBS
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phosphate-buffered saline.
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- Received January 23, 1998.
- Revision received July 10, 1998.
- The American Society for Biochemistry and Molecular Biology, Inc.
