Abstract
(−)-Deprenyl and structurally related propargylamines increase neuronal survival independently of monoamine oxidase B (MAO-B) inhibition, in part by decreasing apoptosis. We found that deprenyl and two other propargylamines, one of which does not inhibit monoamine oxidase B, increased survival in trophically withdrawn 6-day nerve growth factor (NGF)- and 9-day NGF-differentiated PC-12 cells but not in NGF naive or 3-day NGF-differentiated PC-12 cells. Four days of prior NGF exposure were required for the propargylamine-mediated antiapoptosis. Studies using actinomycin D, cycloheximide, and camptothecin revealed that the maintenance of both transcription and translation, particularly between 2 and 6 h after trophic withdrawal, was required for propargylamine-mediated antiapoptosis. Metabolic labeling of newly synthesized proteins for two-dimensional protein gel autoradiography and scintillation counting showed that the propargylamines either increased or reduced the levels of new synthesis or induced de novo synthesis of a number of different proteins, most notably proteins in the mitochondrial and nuclear subfractions. Western blotting for whole cell or subcellular fraction lysates showed that the timing of new protein synthesis changes or subcellular redistribution of apoptosis-related proteins induced by the propargylamines were appropriate to antiapoptosis. The apoptosis-related proteins included superoxide dismutases (SOD1 and SOD2), glutathione peroxidase, c-JUN, and glyceraldehyde-3-phosphate dehydrogenase. Most notable were the prevention of apoptotic decreases in BCL-2 levels and increases in mitochondrial BAX levels. In general, (−)-deprenyl-related propargylamines appear to reduce apoptosis by altering the levels or subcellular localization of proteins that affect mitochondrial membrane permeability, scavenge oxidative radicals, or participate in specific apoptosis signaling pathways.
Footnotes
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This research was supported by a grant from the Lowenstein Foundation and U.S. Army Grant PSA280. Novartis Pharmaceuticals provided CGP 3466, and RetinaPharma International provided (−)-desmethyldeprenyl.
- Abbreviations:
- DEP
- (−)-deprenyl
- ΔΨM
- mitochondrial membrane potential
- DES
- (−)-desmethyldeprenyl
- DRP
- (−)-deprenyl-related propargylamine
- GAPDH
- glyceraldehyde-3-phosphate dehydrogenase
- HBSS
- Hanks' balanced salt solution
- JNK
- c-Jun N-terminal kinase
- MAO-B
- monoamine oxidase B
- MAP-2
- microtubule-associated protein 2
- NGF
- nerve growth factor
- MEM
- minimum essential medium
- mfMEM
- methionine-free MEM
- M/O
- MEM only
- MPTP
- 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
- M/S
- MEM with serum only
- M/S+N
- MEM with serum and NGF
- MPP+
- 1-methyl-4-phenylpyridinium ion
- PBS
- phosphate-buffered saline
- acetyl-DEVD aldehyde
- Ac-Asp-Glu-Val-Asp-CH
- SOD1
- anti-CuZn superoxide dismutase
- SOD2
- Mn superoxide dismutase
- zVAD-fmk
- N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone
- 2D
- two-dimensional
- MOPS
- 4-morpholinepropanesulfonic acid
- Received April 19, 2001.
- Accepted January 24, 2002.
- The American Society for Pharmacology and Experimental Therapeutics
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