Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease
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Case Western Reserve University School of Graduate Studies / OhioLINK
2010
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=case1286464935 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-case12864649352021-08-03T05:33:51Z Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease Sabens, Elizabeth Ann Biochemistry Cellular Biology Pharmacology Parkinson's disease apoptosis levodopa cell signaling enzyme kinetics thiol homeostasis mitogen activated protein kinase Parkinson’s disease (PD), the second most common neurodegenerative disease, is characterized by dopaminergic neuron loss, increased oxidative stress, mitochondrial dysfunction, and protein aggregation. Treatment of PD involves chronic administration of Levodopa (L-DOPA) which paradoxically induces cell death in cellular models of PD. We hypothesized that L-DOPA-induced cell death occurs due to increased oxidative stress disrupting sulfhydryl homeostasis through modification of homeostatic enzymes, glutaredoxin (Grx), GSSG reductase (GR), thioredoxin (Trx), and thioredoxin reductase (TR). Indeed, L-DOPA inhibited Grx in a dose-dependent fashion; however, its content was unaffected. GR activity was not altered. L-DOPA treatments also led to decreased activities of Trx and TR, usually concomitant with diminution of their cellular levels. Experiments involving treatment of the isolated enzymes with oxidized L-DOPA established that only Grx is inactivated in a time- and concentration-dependent fashion, corresponding to irreversible adduction of dopaquinone to the active site cysteine (Cys 22). Furthermore, selective knockdown of Grx or chemical inhibition of TR resulted in increased apoptosis, documenting the neuroblastoma cell’s dependence on both the Grx and Trx systems for survival. In order to further elucidate the mechanism(s) of L-DOPA induced cell death, our studies focused on cell fate pathways regulated by both Grx and Trx. NFκB, normally a prosurvival transcription factor, is regulated by both Grx and Trx where oxidation of various proteins within its activation pathway results in decreased function. Apoptosis signaling kinase 1 (ASK1), a pro-apoptotic MAPKKK, is activated by oxidative stress leading to phosphorylation of downstream MAPKs, p38 and JNK, and initiation of apoptosis. Consistent with this mechanism, L-DOPA treatment of SHSY5Y cells leads to increased phosphorylation of the downstream ASK1 targets, JNK and p38. Furthermore, inhibition of JNK and p38 activity is sufficient to nearly abolish L-DOPA-induced cell death. Knockdown of ASK1 conferred near complete protection from L-DOPA-induced apoptosis, implicating the ASK1 pro-apoptotic pathway as the major effector of L-DOPA-induced cell death. These results elucidate a distinct mechanism of L-DOPA-induced apoptosis and provide the ability to develop new therapeutics aimed at preventing the unwanted side effect of L-DOPA in Parkinson’s disease therapy. 2010 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1286464935 http://rave.ohiolink.edu/etdc/view?acc_num=case1286464935 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
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NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Biochemistry Cellular Biology Pharmacology Parkinson's disease apoptosis levodopa cell signaling enzyme kinetics thiol homeostasis mitogen activated protein kinase |
| spellingShingle |
Biochemistry Cellular Biology Pharmacology Parkinson's disease apoptosis levodopa cell signaling enzyme kinetics thiol homeostasis mitogen activated protein kinase Sabens, Elizabeth Ann Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease |
| author |
Sabens, Elizabeth Ann |
| author_facet |
Sabens, Elizabeth Ann |
| author_sort |
Sabens, Elizabeth Ann |
| title |
Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease |
| title_short |
Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease |
| title_full |
Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease |
| title_fullStr |
Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease |
| title_full_unstemmed |
Levodopa Drug Induced Alteration of Thiol Homeostasis in Model Neurons Activates Apoptosis Signaling Kinase 1: Implications for the Treatment of Parkinson's Disease |
| title_sort |
levodopa drug induced alteration of thiol homeostasis in model neurons activates apoptosis signaling kinase 1: implications for the treatment of parkinson's disease |
| publisher |
Case Western Reserve University School of Graduate Studies / OhioLINK |
| publishDate |
2010 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=case1286464935 |
| work_keys_str_mv |
AT sabenselizabethann levodopadruginducedalterationofthiolhomeostasisinmodelneuronsactivatesapoptosissignalingkinase1implicationsforthetreatmentofparkinsonsdisease |
| _version_ |
1719421785600950272 |