Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicity
<p>Abstract</p> <p>Background</p> <p>Autosomal recessive juvenile parkinsonism (AR-JP) is caused by mutations in the <it>parkin </it>gene which encodes an E3 ubiquitin-protein ligase. Parkin is thought to be critical for protecting dopaminergic neurons from...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2005-12-01
|
| Series: | BMC Neuroscience |
| Online Access: | http://www.biomedcentral.com/1471-2202/6/71 |
| _version_ | 1818857187854778368 |
|---|---|
| author | Palmiter Richard D Curtis Wendy R Perez Francisco A |
| author_facet | Palmiter Richard D Curtis Wendy R Perez Francisco A |
| author_sort | Palmiter Richard D |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Autosomal recessive juvenile parkinsonism (AR-JP) is caused by mutations in the <it>parkin </it>gene which encodes an E3 ubiquitin-protein ligase. Parkin is thought to be critical for protecting dopaminergic neurons from toxic insults by targeting misfolded or oxidatively damaged proteins for proteasomal degradation. Surprisingly, mice with targeted deletions of <it>parkin </it>do not recapitulate robust behavioral or pathological signs of parkinsonism. Since Parkin is thought to protect against neurotoxic insults, we hypothesized that the reason Parkin-deficient mice do not develop parkinsonism is because they are not exposed to appropriate environmental triggers. To test this possibility, we challenged Parkin-deficient mice with neurotoxic regimens of either methamphetamine (METH) or 6-hydroxydopamine (6-OHDA). Because Parkin function has been linked to many of the pathways involved in METH and 6-OHDA toxicity, we predicted that Parkin-deficient mice would be more sensitive to the neurotoxic effects of these agents.</p> <p>Results</p> <p>We found no signs consistent with oxidative stress, ubiquitin dysfunction, or degeneration of striatal dopamine neuron terminals in aged Parkin-deficient mice. Moreover, results from behavioral, neurochemical, and immunoblot analyses indicate that Parkin-deficient mice are not more sensitive to dopaminergic neurotoxicity following treatment with METH or 6-OHDA.</p> <p>Conclusion</p> <p>Our results suggest that the absence of a robust parkinsonian phenotype in Parkin-deficient mice is not due to the lack of exposure to environmental triggers with mechanisms of action similar to METH or 6-OHDA. Nevertheless, Parkin-deficient mice could be more sensitive to other neurotoxins, such as rotenone or MPTP, which have different mechanisms of action; therefore, identifying conditions that precipitate parkinsonism specifically in Parkin-deficient mice would increase the utility of this model and could provide insight into the mechanism of AR-JP. Alternatively, it remains possible that the absence of parkinsonism in Parkin-deficient mice could reflect fundamental differences between the function of human and mouse Parkin, or the existence of a redundant E3 ubiquitin-protein ligase in mouse that is not found in humans. Therefore, additional studies are necessary to understand why Parkin-deficient mice do not display robust signs of parkinsonism.</p> |
| first_indexed | 2024-12-19T08:36:25Z |
| format | Article |
| id | doaj.art-3afce67a221147a390b68252cfff699f |
| institution | Directory Open Access Journal |
| issn | 1471-2202 |
| language | English |
| last_indexed | 2024-12-19T08:36:25Z |
| publishDate | 2005-12-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Neuroscience |
| spelling | doaj.art-3afce67a221147a390b68252cfff699f2022-12-21T20:29:02ZengBMCBMC Neuroscience1471-22022005-12-01617110.1186/1471-2202-6-71Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicityPalmiter Richard DCurtis Wendy RPerez Francisco A<p>Abstract</p> <p>Background</p> <p>Autosomal recessive juvenile parkinsonism (AR-JP) is caused by mutations in the <it>parkin </it>gene which encodes an E3 ubiquitin-protein ligase. Parkin is thought to be critical for protecting dopaminergic neurons from toxic insults by targeting misfolded or oxidatively damaged proteins for proteasomal degradation. Surprisingly, mice with targeted deletions of <it>parkin </it>do not recapitulate robust behavioral or pathological signs of parkinsonism. Since Parkin is thought to protect against neurotoxic insults, we hypothesized that the reason Parkin-deficient mice do not develop parkinsonism is because they are not exposed to appropriate environmental triggers. To test this possibility, we challenged Parkin-deficient mice with neurotoxic regimens of either methamphetamine (METH) or 6-hydroxydopamine (6-OHDA). Because Parkin function has been linked to many of the pathways involved in METH and 6-OHDA toxicity, we predicted that Parkin-deficient mice would be more sensitive to the neurotoxic effects of these agents.</p> <p>Results</p> <p>We found no signs consistent with oxidative stress, ubiquitin dysfunction, or degeneration of striatal dopamine neuron terminals in aged Parkin-deficient mice. Moreover, results from behavioral, neurochemical, and immunoblot analyses indicate that Parkin-deficient mice are not more sensitive to dopaminergic neurotoxicity following treatment with METH or 6-OHDA.</p> <p>Conclusion</p> <p>Our results suggest that the absence of a robust parkinsonian phenotype in Parkin-deficient mice is not due to the lack of exposure to environmental triggers with mechanisms of action similar to METH or 6-OHDA. Nevertheless, Parkin-deficient mice could be more sensitive to other neurotoxins, such as rotenone or MPTP, which have different mechanisms of action; therefore, identifying conditions that precipitate parkinsonism specifically in Parkin-deficient mice would increase the utility of this model and could provide insight into the mechanism of AR-JP. Alternatively, it remains possible that the absence of parkinsonism in Parkin-deficient mice could reflect fundamental differences between the function of human and mouse Parkin, or the existence of a redundant E3 ubiquitin-protein ligase in mouse that is not found in humans. Therefore, additional studies are necessary to understand why Parkin-deficient mice do not display robust signs of parkinsonism.</p>http://www.biomedcentral.com/1471-2202/6/71 |
| spellingShingle | Palmiter Richard D Curtis Wendy R Perez Francisco A Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicity BMC Neuroscience |
| title | Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicity |
| title_full | Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicity |
| title_fullStr | Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicity |
| title_full_unstemmed | Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicity |
| title_short | Parkin-deficient mice are not more sensitive to 6-hydroxydopamine or methamphetamine neurotoxicity |
| title_sort | parkin deficient mice are not more sensitive to 6 hydroxydopamine or methamphetamine neurotoxicity |
| url | http://www.biomedcentral.com/1471-2202/6/71 |
| work_keys_str_mv | AT palmiterrichardd parkindeficientmicearenotmoresensitiveto6hydroxydopamineormethamphetamineneurotoxicity AT curtiswendyr parkindeficientmicearenotmoresensitiveto6hydroxydopamineormethamphetamineneurotoxicity AT perezfranciscoa parkindeficientmicearenotmoresensitiveto6hydroxydopamineormethamphetamineneurotoxicity |