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Conference Paper: Knock-down of uncoupling protein-5 (UCP5) in neuronal cells reduces mitochondrial membrane depolarization and increases oxidative stress induced by MPP+.

TitleKnock-down of uncoupling protein-5 (UCP5) in neuronal cells reduces mitochondrial membrane depolarization and increases oxidative stress induced by MPP+.
Authors
Issue Date2006
PublisherJohn Wiley & Sons, Inc. The Journal's web site is located at http://www3.interscience.wiley.com/cgi-bin/jhome/76507419
Citation
The 1st World Parkinson Congress (WPC 2006), Washington, DC., 22-26 February 2006. In Moving Disorders, 2006, v. 21 suppl. S13, p. S67, abstract no. P54 How to Cite?
AbstractOBJECTIVE: We explored UCP5 and its link to oxidative stress, mitochondrial membrane potential (MMP), ATP levels and cell viability under normal conditions and in MPP+-induced toxicity. BACKGROUND: Oxidative stress associated with mitochondrial dysfunction are found in Parkinson’s disease. Uncoupling proteins (UCPs) uncouple oxidative phosphorylation from ATP synthesis by dissipating MMP across mitochondrial inner membrane. Five isoforms (UCP1-5) have been identified. The role of neuronal specific UCP5 in mitochondrial dysfunction is unknown. METHODS: SH-SY5Y neuronal cells were transfected with UCP5 RNAi before MPP+ exposure 24 hrs later. At 48 hrs, cell viability, oxidative stress and ATP levels, and MMP were determined under normal conditions and in MPP+-induced toxicity. Cell viability and ATP level were measured using MTT assay and luciferin-luciferase bioluminescene assay, respectively. MMP and oxidative stress were determined by JC-1 and dihydroethidium (DHE) staining in flow cytometry, respectively. Western and real-time RT-PCR analyses were used to determine UCP expression. RESULTS: UCP5 protein expression knockdown by 56% (p_0.01) was associated with decreased (21%; p<0.01) cell viability compared with controls transfected with scrambled siRNA. UCP2 and UCP4 mRNA levels did not change after UCP5 knockdown. UCP5 knockdown before MPP+ exposure further decreased cell viability (14%) but did not modify ATP levels. MPP+ increased oxidative stress by three-fold and mitochondrial membrane depolarization by 15-fold. Oxidative stress levels did not alter after UCP5 knockdown under normal conditions but was elevated (40%; p<0.01) in MPP+-induced toxicity compared to controls without knockdown. Similarly, MMP did not change under normal conditions after UCP5 knockdown but it was reduced in MPP+-induced depolarization (57%; p<0.01). CONCLUSION: UCP5 knockdown did not affect basal levels of ATP, oxidative free radicals or mitochondrial membrane potential. Under MPP+-induced oxidative stress, UCP5 knockdown reduced the depolarizing effects of MPP+ and further increased oxidative stress, indicating that UCP5 might be neuroprotective in reducing MPP+-induced cytotoxicity. The lack of change in UCP2 and UCP4 expression indicated that there were no compensatory effects from these isoforms after UCP knockdown.
DescriptionPoster Sessions: Basic Science - Mitochondria, oxidative stress, Inflammation, and other pathogeneses
Persistent Identifierhttp://hdl.handle.net/10722/101698
ISSN
2015 Impact Factor: 6.01
2015 SCImago Journal Rankings: 2.733

 

DC FieldValueLanguage
dc.contributor.authorHo, PWLen_HK
dc.contributor.authorChu, ACYen_HK
dc.contributor.authorKwok, KHHen_HK
dc.contributor.authorKung, MHWen_HK
dc.contributor.authorRamsden, DBen_HK
dc.date.accessioned2010-09-25T20:00:13Z-
dc.date.available2010-09-25T20:00:13Z-
dc.date.issued2006en_HK
dc.identifier.citationThe 1st World Parkinson Congress (WPC 2006), Washington, DC., 22-26 February 2006. In Moving Disorders, 2006, v. 21 suppl. S13, p. S67, abstract no. P54en_HK
dc.identifier.issn0885-3185-
dc.identifier.urihttp://hdl.handle.net/10722/101698-
dc.descriptionPoster Sessions: Basic Science - Mitochondria, oxidative stress, Inflammation, and other pathogeneses-
dc.description.abstractOBJECTIVE: We explored UCP5 and its link to oxidative stress, mitochondrial membrane potential (MMP), ATP levels and cell viability under normal conditions and in MPP+-induced toxicity. BACKGROUND: Oxidative stress associated with mitochondrial dysfunction are found in Parkinson’s disease. Uncoupling proteins (UCPs) uncouple oxidative phosphorylation from ATP synthesis by dissipating MMP across mitochondrial inner membrane. Five isoforms (UCP1-5) have been identified. The role of neuronal specific UCP5 in mitochondrial dysfunction is unknown. METHODS: SH-SY5Y neuronal cells were transfected with UCP5 RNAi before MPP+ exposure 24 hrs later. At 48 hrs, cell viability, oxidative stress and ATP levels, and MMP were determined under normal conditions and in MPP+-induced toxicity. Cell viability and ATP level were measured using MTT assay and luciferin-luciferase bioluminescene assay, respectively. MMP and oxidative stress were determined by JC-1 and dihydroethidium (DHE) staining in flow cytometry, respectively. Western and real-time RT-PCR analyses were used to determine UCP expression. RESULTS: UCP5 protein expression knockdown by 56% (p_0.01) was associated with decreased (21%; p<0.01) cell viability compared with controls transfected with scrambled siRNA. UCP2 and UCP4 mRNA levels did not change after UCP5 knockdown. UCP5 knockdown before MPP+ exposure further decreased cell viability (14%) but did not modify ATP levels. MPP+ increased oxidative stress by three-fold and mitochondrial membrane depolarization by 15-fold. Oxidative stress levels did not alter after UCP5 knockdown under normal conditions but was elevated (40%; p<0.01) in MPP+-induced toxicity compared to controls without knockdown. Similarly, MMP did not change under normal conditions after UCP5 knockdown but it was reduced in MPP+-induced depolarization (57%; p<0.01). CONCLUSION: UCP5 knockdown did not affect basal levels of ATP, oxidative free radicals or mitochondrial membrane potential. Under MPP+-induced oxidative stress, UCP5 knockdown reduced the depolarizing effects of MPP+ and further increased oxidative stress, indicating that UCP5 might be neuroprotective in reducing MPP+-induced cytotoxicity. The lack of change in UCP2 and UCP4 expression indicated that there were no compensatory effects from these isoforms after UCP knockdown.-
dc.languageengen_HK
dc.publisherJohn Wiley & Sons, Inc. The Journal's web site is located at http://www3.interscience.wiley.com/cgi-bin/jhome/76507419-
dc.relation.ispartofMoving Disordersen_HK
dc.rightsMovement Disorders. Copyright © John Wiley & Sons, Inc.-
dc.titleKnock-down of uncoupling protein-5 (UCP5) in neuronal cells reduces mitochondrial membrane depolarization and increases oxidative stress induced by MPP+.en_HK
dc.typeConference_Paperen_HK
dc.identifier.emailChu, ACY: bcccy@hkucc.hku.hken_HK
dc.identifier.authorityChu, ACY=rp00505en_HK
dc.identifier.doi10.1002/mds.20869-
dc.identifier.hkuros119566en_HK
dc.identifier.volume21en_HK
dc.identifier.issuesuppl. S13-
dc.identifier.spageS67, abstract no. P54en_HK
dc.identifier.epageS67, abstract no. P54-
dc.publisher.placeUnited States-

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