Death commitment point is advanced by axotomy in sympathetic neurons.
Axotomized neurons have several characteristics that are different from intact neurons. Here we show that, unlike established cultures, the axotomized sympathetic neurons deprived of NGF become committed to die before caspase activation, since the same proportion of NGF-deprived neurons are rescued...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2000
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| _version_ | 1797087235780116480 |
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| author | Fletcher, G Xue, L Passingham, S Tolkovsky, A |
| author_facet | Fletcher, G Xue, L Passingham, S Tolkovsky, A |
| author_sort | Fletcher, G |
| collection | OXFORD |
| description | Axotomized neurons have several characteristics that are different from intact neurons. Here we show that, unlike established cultures, the axotomized sympathetic neurons deprived of NGF become committed to die before caspase activation, since the same proportion of NGF-deprived neurons are rescued by NGF regardless of whether caspases are inhibited by the pan-caspase inhibitor Boc-Asp(O-methyl)-CH(2)F (BAF). Despite prolonged Akt and ERK signaling induced by NGF after BAF treatment has prevented death, the neurons fail to increase protein synthesis, recover ATP levels, or grow. Within 3 d, all the mitochondria disappear without apparent removal of any other organelles or loss of membrane integrity. Although NGF does rescue intact BAF-treated 6-d cultures after NGF deprivation, rescue by NGF fails when these neurons are axotomized before NGF deprivation and BAF treatment. Moreover, cytosolic cytochrome c rapidly kills axotomized neurons. We propose that axotomy induces signals that make sympathetic neurons competent to die prematurely. NGF cannot repair these NGF-deprived, BAF-treated neurons because receptor signaling (which is normal) is uncoupled from protein renewal, and the mitochondria (which are damaged) go on to be eliminated. Hence, the order of steps underlying neuronal death commitment is mutable and open to regulation. |
| first_indexed | 2024-03-07T02:32:56Z |
| format | Journal article |
| id | oxford-uuid:a7daec9c-a4d1-4b9b-a404-76dac8617a83 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:32:56Z |
| publishDate | 2000 |
| record_format | dspace |
| spelling | oxford-uuid:a7daec9c-a4d1-4b9b-a404-76dac8617a832022-03-27T02:57:17ZDeath commitment point is advanced by axotomy in sympathetic neurons.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a7daec9c-a4d1-4b9b-a404-76dac8617a83EnglishSymplectic Elements at Oxford2000Fletcher, GXue, LPassingham, STolkovsky, AAxotomized neurons have several characteristics that are different from intact neurons. Here we show that, unlike established cultures, the axotomized sympathetic neurons deprived of NGF become committed to die before caspase activation, since the same proportion of NGF-deprived neurons are rescued by NGF regardless of whether caspases are inhibited by the pan-caspase inhibitor Boc-Asp(O-methyl)-CH(2)F (BAF). Despite prolonged Akt and ERK signaling induced by NGF after BAF treatment has prevented death, the neurons fail to increase protein synthesis, recover ATP levels, or grow. Within 3 d, all the mitochondria disappear without apparent removal of any other organelles or loss of membrane integrity. Although NGF does rescue intact BAF-treated 6-d cultures after NGF deprivation, rescue by NGF fails when these neurons are axotomized before NGF deprivation and BAF treatment. Moreover, cytosolic cytochrome c rapidly kills axotomized neurons. We propose that axotomy induces signals that make sympathetic neurons competent to die prematurely. NGF cannot repair these NGF-deprived, BAF-treated neurons because receptor signaling (which is normal) is uncoupled from protein renewal, and the mitochondria (which are damaged) go on to be eliminated. Hence, the order of steps underlying neuronal death commitment is mutable and open to regulation. |
| spellingShingle | Fletcher, G Xue, L Passingham, S Tolkovsky, A Death commitment point is advanced by axotomy in sympathetic neurons. |
| title | Death commitment point is advanced by axotomy in sympathetic neurons. |
| title_full | Death commitment point is advanced by axotomy in sympathetic neurons. |
| title_fullStr | Death commitment point is advanced by axotomy in sympathetic neurons. |
| title_full_unstemmed | Death commitment point is advanced by axotomy in sympathetic neurons. |
| title_short | Death commitment point is advanced by axotomy in sympathetic neurons. |
| title_sort | death commitment point is advanced by axotomy in sympathetic neurons |
| work_keys_str_mv | AT fletcherg deathcommitmentpointisadvancedbyaxotomyinsympatheticneurons AT xuel deathcommitmentpointisadvancedbyaxotomyinsympatheticneurons AT passinghams deathcommitmentpointisadvancedbyaxotomyinsympatheticneurons AT tolkovskya deathcommitmentpointisadvancedbyaxotomyinsympatheticneurons |