Studies (Glutathione and Parkinson's Disease)

J Dermatol Sci. 2007 Aug;47(2):141-9. Epub 2007 May 4.

1. Glutathione prevented dopamine-induced apoptosis of melanocytes and its signaling.

Park ES, Kim SY, Na JI, Ryu HS, Youn SW, Kim DS, Yun HY, Park KC.

Department of Dermatology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-744, Republic of Korea.

BACKGROUND: Dopamine (DA), a monoamine neurotransmitter, is a well-known neurotoxin and plays an etiologic role in neurodegenerative disorders such as Parkinson's disease. DA exerts its toxic effect by generation of reactive oxygen species and quinone product. Vitiligo, a depigmentary disorder of the skin and hair characterized by selective destruction of melanocytes, has been reported to show increased levels of DA with onset and progression of the disease. OBJECTIVE: The aim of this study is to investigate the cytotoxic effect of DA on melanocytes and to search for protective antioxidants against DA-induced toxicity. In addition, molecular mechanism of cell death was also investigated. METHODS: Cells were treated with DA and cell viabilities were measured by crystal violet staining method. To investigate the cytoprotective activity of various antioxidants, vitamin C, vitamin E, Trolox, quercetin, N-acetylcysteine (NAC) and l-glutathione (GSH) were used. To study cytoprotective effects of NAC and GSH, Mel-Ab cells and cultured normal human melanocytes were pretreated with NAC or GSH, then DA solution was added. DA-induced apoptosis and activation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) were also observed by flow cytometric analysis and Western blotting. RESULTS: The viability of DA-treated Mel-Ab cells significantly decreased in a dose-dependent manner while keratinocytes were much more resistant to DA-toxicity, which was a consistent finding with the selective melanocyte loss observed in vitiligo. Among various antioxidants used in this study, only thiol-containing antioxidants such as NAC or GSH inhibited both JNK and p38 MAPK activation and apoptosis, indicating the unique protective capacity of thiol compounds. Cultured normal human melanocytes were also susceptible to DA and thiol compounds were very efficiently protective against DA-induced cytotoxicity. CONCLUSION: DA-induced apoptosis and cytoprotective effect of thiol compounds shown in this study could be a clue to understand pathogenesis of viltigo and provide a new therapeutic strategy.

PMID: 17481858 [PubMed - in process]

Nutrition. 2007 Jul-Aug;23(7-8):589-97. Epub 2007 Jun 18.

2. Antioxidative and anti-inflammatory effects of four cysteine-containing agents in striatum of MPTP-treated mice.

Chen CM, Yin MC, Hsu CC, Liu TC.

Department of Neurology, Chung Shan Medical University Hospital, Taichung City, Taiwan.

OBJECTIVES: Mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used to examine the neuroprotective effects of n-acetyl cysteine (NAC), s-ethyl cysteine (SEC), s-methyl cysteine (SMC), and s-propyl cysteine (SPC). METHODS: Each agent at 1 g/L was directly added to the drinking water for 3 wk. Mice were treated by subcutaneous injection of MPTP (24 mg/kg body weight) for 6 consecutive days. The brain from each mouse was quickly removed and the striatum was collected for analyses. RESULTS: The MPTP treatment significantly depleted striatal glutathione content, reduced the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase, increased malondialdehyde level, and elevated interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) levels in striatum (P < 0.05). The pre-intake of NAC, SEC, SMC, and SPC significantly attenuated MPTP-induced glutathione loss, retained the activity of GPX and SOD, diminished oxidative stress, and suppressed MPTP-induced elevation of IL-6 and TNF-alpha (P < 0.05). MPTP treatment significantly suppressed GPX mRNA expression and enhanced TNF-alpha mRNA expression (P < 0.05). Compared with MPTP treatment alone, the pre-intake of NAC, SEC, SMC, and SPC significantly elevated GPX mRNA expression and diminished TNF-alpha mRNA expression (P < 0.05), in which SPC showed the greatest suppressive effect against MPTP-induced TNF-alpha mRNA expression (P < 0.05). Dopamine and 3,4-dihydroxyphenylacetic acid contents in the striatum were significantly decreased by MPTP treatment (P < 0.05). The pre-intake of four test agents significantly improved MPTP-induced dopamine depletion and increased dopamine/3,4-dihydroxyphenylacetic acid content (P < 0.05). CONCLUSION: These results suggest that these cysteine-containing compounds could provide antioxidative and anti-inflammatory protection for the striatum against the development of Parkinson's disease.

PMID: 17574387 [PubMed - in process]

Neurochem Res. 2007 Jun 6; [Epub ahead of print]

3. Lipid Peroxidation Scavengers Prevent the Carbonylation of Cytoskeletal Brain Proteins Induced by Glutathione Depletion.

Bizzozero OA, Reyes S, Ziegler J, Smerjac S.

Department of Cell Biology and Physiology, University of New Mexico—Health Sciences Center, Basic Medical Sciences Building, Room #151, 914 Camino de Salud, Albuquerque, NM, 87131-5218, USA,

In this study, we investigated the possible link between lipid peroxidation (LPO) and the formation of protein carbonyls (PCOs) during depletion of brain glutathione (GSH). To this end, rat brain slices were incubated with the GSH depletor diethyl maleate (DEM) in the absence or presence of classical LPO scavengers: trolox, caffeic acid phenethyl ester (CAPE), and butylated hydroxytoluene (BHT). All three scavengers reduced DEM-induced lipid oxidation and protein carbonylation, suggesting that intermediates/products of the LPO pathway such as lipid hydroperoxides, 4-hydroxynonenal and/or malondialdehyde are involved in the process. Additional in vitro experiments revealed that, among these products, lipid hydroperoxides are most likely responsible for protein oxidation. Interestingly, BHT prevented the carbonylation of cytoskeletal proteins but not that of soluble proteins, suggesting the existence of different mechanisms of PCO formation during GSH depletion. In pull-down experiments, beta-actin and alpha/beta-tubulin were identified as major carbonylation targets during GSH depletion, although other cytoskeletal proteins such as neurofilament proteins and glial fibrillary acidic protein were also carbonylated. These findings may be important in the context of neurological disorders that exhibit decreased GSH levels and increased protein carbonylation such as Parkinson's disease, Alzheimer's disease, and multiple sclerosis.

PMID: 17551832 [PubMed - as supplied by publisher]

J Neurosci. 2007 Apr 18;27(16):4326-33.

4. An orally active catalytic metalloporphyrin protects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity in vivo.

Liang LP, Huang J, Fulton R, Day BJ, Patel M.

Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.

Parkinson's disease (PD) is an age-related neurodegenerative disease in which the role of reactive oxygen species (ROS) is strongly implicated. The presence of oxidative stress has been detected in human and experimental PD using both direct and indirect indices. Scavenging ROS is, therefore, an important therapeutic avenue for the treatment of PD. Manganic porphyrins are catalytic antioxidants that scavenge a wide range of ROS. In this study, we tested the therapeutic effects of a compound [5,15-bis(methoxycarbonyl)-10,20-bis-trifluoromethyl-porphyrinato manganese (III) chloride (AEOL11207)] belonging to a new generation of lipophilic manganic porphyrins for neuroprotection and oral bioavailability in the mouse 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of parkinsonism. Groups of adult C57BL/6 mice were administered MPTP with varying subcutaneous or oral dosing regimens of AEOL11207. Neurotoxicity was assessed by measurement of striatal dopamine levels and quantification of tyrosine hydroxylase-positive neurons in the substantial nigra pars compacta one week after the first dose of MPTP. Glutathione depletion, lipid peroxidation, and 3-nitrotyrosine (3-NT) formation were measured as indicators of oxidative stress in the ventral midbrain in vivo. AEOL11207 administered either by subcutaneous or oral routes protected against MPTP-induced dopamine depletion in the striatum as well as dopaminergic neuronal loss, glutathione depletion, lipid peroxidation, and 3-NT formation in the ventral midbrain. Neuroprotection correlated with brain metalloporphyrin concentrations. This is the first demonstration of neuroprotection by an orally active catalytic antioxidant in the MPTP mouse model and suggests its potential clinical utility for the treatment of chronic neurodegenerative diseases such as PD.

PMID: 17442816 [PubMed - indexed for MEDLINE]

J Biol Chem. 2007 Feb 16;282(7):4364-72. Epub 2006 Dec 8.

5. Proteasome inhibition induces glutathione synthesis and protects cells from oxidative stress: relevance to Parkinson disease.

Yamamoto N, Sawada H, Izumi Y, Kume T, Katsuki H, Shimohama S, Akaike A.

Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.

The cause of selective dopaminergic neuronal degeneration in Parkinson disease has still not been resolved, but it has been hypothesized that oxidative stress and the ubiquitin-proteasome system are important in the pathogenesis. In this report, we investigated the effect of proteasome inhibition on oxidative stress-induced cytotoxicity in PC12 cells, an in vitro model of Parkinson disease. Treatment with proteasome inhibitors provided significant protection against toxicity by 6-hydroxydopamine and H(2)O(2) in a concentration-dependent manner. The measurement of intracellular reactive oxygen species using 2',7'-dichlorofluorescein diacetate demonstrated that lactacystin, a proteasome inhibitor, significantly reduced 6-hydroxydopamineand H(2)O(2)-induced reactive oxygen species production. Proteasome inhibitors elevated the amount of glutathione and phosphorylated p38 mitogen-activated protein kinase (MAPK) prior to glutathione elevation. The treatment with lactacystin induced the nuclear translocation of NF-E2-related factor 2 (Nrf2) and increased the level of mRNA for gamma-glutamylcysteine synthetase, a rate-limiting enzyme in glutathione synthesis. Furthermore, SB203580, an inhibitor of p38 MAPK, abolished glutathione elevation and cytoprotection by lactacystin. These data suggest that proteasome inhibition afforded cytoprotection against oxidative stress by the elevation of glutathione content, and its elevation was mediated by p38 MAPK phosphorylation.

PMID: 17158454 [PubMed - indexed for MEDLINE]

Exp Neurol. 2007 Feb;203(2):512-20. Epub 2006 Oct 17.

6. Characterization of intracellular elevation of glutathione (GSH) with glutathione monoethyl ester and GSH in brain and neuronal cultures: relevance to Parkinson's disease.

Zeevalk GD, Manzino L, Sonsalla PK, Bernard LP.

Department of Neurology, UMDNJ-Robert Wood Johnson Medical School, Building UBHC, Rm. 405D, 675 Hoes Lane, Piscataway, NJ 08854, USA.

Parkinson's disease (PD) is associated with loss of total glutathione (GSH) which may contribute to progressive cell death. Peripheral GSH administration has been used clinically with reported benefits. Despite this, there is little specific information to characterize its cellular uptake or clearance, brain elevation with peripheral delivery or neuroprotective efficacy in PD models. The current study was carried out to provide this information using in vitro and in vivo approaches. In rat mesencephalic culture, the monoethyl ester of GSH (GEE), but not GSH (1-10 mM, 24 h) produced a dose-dependent elevation in GSH. The half-life for clearance was 10.14 h and was not different in cells depleted of GSH prior to loading. Elevation of GSH with GEE protected neurons from oxidative stress with H2O2 or metabolic stress with the complex I and II inhibitors MPP+ and malonate, respectively. To determine if peripheral administration of GEE could elevate brain GSH levels, rats were administered 0.1-50 mg/kg/day GEE via osmotic minipump either subcutaneously (sc) or via a cannula placed into the left cerebral ventricle (icv) for 28 days. Only central delivery of GEE resulted in significant elevations of brain GSH. Elevation of brain GSH by icv infusion of GEE was examined for its neuroprotective effects against chronic central delivery of MPP+. Infusion of 0.142 mg/kg/day MPP+ for 28 days caused a selective ipsilateral loss of striatal dopamine. Co-infusion of MPP+ with 10 mg/kg/day GEE significantly protected against striatal dopamine loss. These findings show that the ethyl ester of GSH but not GSH per se can elevate intracellular GSH, that brain elevation of GSH requires central delivery of the ethyl ester and that this elevation provides neuroprotection against oxidative stress or chronic mitochondrial impairment.

PMID: 17049515 [PubMed - indexed for MEDLINE]

Free Radic Biol Med. 2006 Nov 1;41(9):1442-8. Epub 2006 Aug 7.

7. Reversible inhibition of mitochondrial complex I activity following chronic dopaminergic glutathione depletion in vitro: implications for Parkinson's disease.

Chinta SJ, Andersen JK.

Buck Institute for Age Research, 8001 Redwood Boulevard, Novato, CA 94945, USA.

The pathogenesis underlying the selective degeneration of nigral dopaminergic neurons in Parkinson's disease is not fully understood but several lines of evidence implicate the role of oxidative stress and mitochondrial dysfunction. Depletion in levels of the thiol reducing agent glutathione (GSH + GSSG) is the earliest reported biochemical event to occur in the Parkinsonian substantia nigra prior to selective loss of complex I (CI) activity associated with the disease believed to contribute to subsequent dopaminergic cell death. Recent studies from our laboratory have demonstrated that acute reduction in both cellular and mitochondrial glutathione levels results in increased oxidative stress and a decrease in mitochondrial function linked to a selective decrease in CI activity through an NO-mediated mechanism (Jha, N.; Jurma, O.; Lalli, G.; Liu, Y.; Pettus, E. H.; Greenamyre, J. T.; Liu, R. M.; Forman, H. J.; Andersen, J. K. Glutathione depletion in PC12 results in selective inhibition of mitochondrial complex I activity. Implications for Parkinson's disease J. Biol. Chem. 275: 26096-26101; 2000. Hsu, M.; Srinivas, B.; Kumar, J.; Subramanian, R.; Andersen, J. Glutathione depletion resulting in selective mitochondrial complex I inhibition in dopaminergic cells is via an NO-mediated pathway not involving peroxynitrite: implications for Parkinson's disease J. Neurochem. 92: 1091-1103.2005.). However, the effect of prolonged glutathione depletion on dopaminergic cells is not known. In this present study, using low concentrations of buthionine-S-sulfoximine, a chemical inhibitor of the de novo glutathione synthesizing enzyme glutamate cysteine ligase, we developed a chronic model in which glutathione depletion in dopaminergic N27 cells for a 7-day period was found to lead to inhibition of CI activity via a peroxynitrite-mediated event which is reversible by the thiol reducing agent, dithiothreitol, and coincides with increased S-nitrosation of mitochondrial proteins.

PMID: 17023271 [PubMed - indexed for MEDLINE]

Neurosci Lett. 2006 Jul 10;402(1-2):137-41. Epub 2006 Apr 27.

8. In vitro and in vivo neuroprotection by gamma-glutamylcysteine ethyl ester against MPTP: relevance to the role of glutathione in Parkinson's disease.

Chinta SJ, Rajagopalan S, Butterfield DA, Andersen JK. Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, United States.

Glutathione is an abundant intracellular thiol antioxidant whose levels are reduced both in Parkinson's disease itself and in a widely used animal model of the disorder, systemic MPTP administration. Previous in vitro work from our laboratory has suggested that glutathione depletion may be directly responsible for mitochondrial dysfunction, which ultimately leads to dopaminergic cell death associated with the disease. Here, we demonstrate the ability of gamma-glutamylcysteine ethyl ester, a lipid permeable derivative of the major substrate for scavenger glutathione synthesis, to counteract glutathione loss and neurodegeneration associated with in vitro and in vivo administration of MPTP or its derivatives. This data suggests that prevention of glutathione depletion is a likely therapeutic target for the disease.

PMID: 16644116 [PubMed - indexed for MEDLINE]

Antioxid Redox Signal. 2005 Jul-Aug;7(7-8):900-10.

9. Glutathione depletion in a midbrain-derived immortalized dopaminergic cell line results in limited tyrosine nitration of mitochondrial complex I subunits: implications for Parkinson's disease.

Bharath S, Andersen JK.

Buck Institute for Age Research, Novato, CA 94945, USA.

Oxidative stress and mitochondrial dysfunction signify two important biochemical events associated with the loss of dopaminergic neurons in Parkinson's disease (PD). Studies using in vitro and in vivo PD models and in affected tissues from the disease itself have demonstrated a selective inhibition of mitochondrial complex I activity that appears to affect normal mitochondrial physiology leading to neuronal cell death. Earlier experiments from our laboratory have demonstrated that induced depletion of glutathione (GSH + GSSG) in cultured dopaminergic cells resulted in increased oxidative stress and a decrease in mitochondrial function. Furthermore, this dysfunction was linked to a selective decrease in mitochondrial complex I activity that appears to be due to oxidation of this complex. Glutathione depletion is the earliest detectable biochemical event during PD progression and occurs prior to complex I inhibition. Recent observations have also indicated that oxidative damage to complex I via naturally occurring free radicals such as peroxynitrite leads to modification of tyrosine and/or cysteine residues resulting in complex I inhibition. Using the sucrose gradient method, we detected in complex I-enriched fractions from a glutathione-depleted dopaminergic cell line two bands corresponding to approximately 25-kDa and approximately 30-kDa polypeptides that demonstrate anti-nitrotyrosine immunoreactivity, suggesting the possible involvement of protein nitration by peroxynitrite in glutathione depletion-mediated complex I inhibition.

PMID: 15998245 [PubMed - indexed for MEDLINE]

J Neurochem. 2005 Mar;92(5):1091-103.

10. Glutathione depletion resulting in selective mitochondrial complex I inhibition in dopaminergic cells is via an NO-mediated pathway not involving peroxynitrite: implications for Parkinson's disease.

Hsu M, Srinivas B, Kumar J, Subramanian R, Andersen J.

Department of Molecular Biology, University of Southern California, Los Angeles, California, USA.

An early biochemical change in the Parkinsonian substantia nigra (SN) is reduction in total glutathione (GSH + GSSG) levels in affected dopaminergic neurons prior to depletion in mitochondrial complex I activity, dopamine loss, and cell death. We have demonstrated using dopaminergic PC12 cell lines genetically engineered to inducibly down-regulate glutathione synthesis that total glutathione depletion in these cells results in selective complex I inhibition via a reversible thiol oxidation event. Here, we demonstrate that inhibition of complex I may occur either by direct nitric oxide (NO) but not peroxinitrite-mediated inhibition of complex I or through H2O2-mediated inhibition of the tricarboxylic acid (TCA) cycle enzyme alpha-ketoglutarate dehydrogenase (KGDH) which supplies NADH as substrate to the complex; activity of both enzymes are reduced in PD. While glutathione depletion causes a reduction in spare KGDH enzymatic capacity, it produces a complete collapse of complex I reserves and significant effects on mitochondrial function. Our data suggest that NO is likely the primary agent involved in preferential complex I inhibition following acute glutathione depletion in dopaminergic cells. This may have major implications in terms of understanding mechanisms of dopamine cell death associated with PD especially as they relate to complex I inhibition.

PMID: 15715660 [PubMed - indexed for MEDLINE]

Indian J Med Res. 2005 Feb;121(2):111-5.

11. Erythrocyte antioxidant enzymes in Parkinson's disease.

Abraham S, Soundararajan CC, Vivekanandhan S, Behari M.

Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.

BACKGROUND & OBJECTIVES: Oxidative stress is incriminated to play a central role in the pathogenesis of Parkinson's disease (PD). Oxidative stress, to which neurons are highly susceptible, is also known to induce oxidative changes in human red blood cells (RBCs), in vivo and in vitro. Earlier studies on oxidative stress in RBCs in patients with PD have yielded controversial results claiming unaltered activity to reduced activity. Using RBC as a model, we have undertaken this study to ascertain the possibility of oxidative damage to the RBCs in PD by measuring the cytosolic antioxidant enzymes viz., superoxide dismutase (SOD), catalase (CAT) glutathione peroxidase (G-Px) and glucose-6-phosphate dehydrogenase (G6PD). METHODS: Activities of antioxidant enzymes were measured in erythrocytes of 115 PD patients and 37 normal age-matched healthy persons as controls. Enzymes activities were correlated with age of patients, age of onset of disease, duration of disease, United Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr stage. RESULTS: The SOD, CAT, G-Px and G6PD activities were significantly lower in patients with PD compared to the control. A significant (P<0.05) negative correlation of enzyme activities with Hoehn and Yahr stage of the disease and also with UPDRS score was found. INTERPRETATION & CONCLUSION: Results of the present study showed involvement of oxidative stress as one of the risk factors, which can initiate and/or promote neurodegeneration in PD and was correlated to the severity of the disease.