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Query: UMLS:C0030567 (
Parkinson's disease
)
63,064
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Recent studies have demonstrated that activated microglia play an important role in dopamine (DA) neuronal degeneration in
Parkinson disease
(PD) by generating NADPH-oxidase (NADPHO)-derived superoxide. However, the molecular mechanisms that underlie microglial activation in DA cell death are still disputed. We report here that matrix metalloproteinase-3 (MMP-3) was newly induced and activated in stressed DA cells, and the active form of MMP-3 (actMMP-3) was released into the medium. The released actMMP-3, as well as catalytically active recombinant MMP-3 (cMMP-3) led to microglial activation and superoxide generation in microglia and enhanced DA cell death. cMMP-3 caused DA cell death in mesencephalic neuron-glia mixed culture of wild-type (WT) mice, but this was attenuated in the culture of NADPHO subunit null mice (gp91(phox-/-)), suggesting that NADPHO mediated the cMMP-3-induced microglial production of superoxide and DA cell death. Furthermore, in the N-methyl-
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP)-injected animal model of PD, nigrostriatal DA neuronal degeneration, microglial activation, and superoxide generation were largely attenuated in MMP-3-/- mice. These results indicate that actMMP-3 released from stressed DA neurons is responsible for microglial activation and generation of NADPHO-derived superoxide and eventually enhances nigrostriatal DA neuronal degeneration. Our results could lead to a novel therapeutic approach to PD.
...
PMID:A pivotal role of matrix metalloproteinase-3 activity in dopaminergic neuronal degeneration via microglial activation. 1711 47
The neuropeptide melanocyte-inhibiting factor (MIF) or L-propyl-L-leucyl-glycinamide (PLG) has been reported in some studies to improve the motor signs of
Parkinson's disease
(PD) and in rodent models of PD. In this study of oral and intravenous MIF in N-methyl-
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP)-lesioned marmosets, a wide range of doses of MIF administered alone (0.25, 1, 2, 5, 10, 20 mg/kg orally) did not increase locomotor activity, relieve motor disability, or induce dyskinesias. When MIF (1.0 and 5.0 mg/kg orally or 10 and 20 mg/kg intravenously) was administered concomitantly with levodopa/benserazide, no significant differences in motor function or dyskinesias were observed compared with levodopa/benserazide alone. The results of this first study of MIF in the marmoset MPTP model provide no encouragement for the reinvestigation of MIF in the clinical management of the motor signs of PD.
...
PMID:Antiparkinsonian activity of L-propyl-L-leucyl-glycinamide or melanocyte-inhibiting factor in MPTP-treated common marmosets. 1737 23
Central adenosine A(2A) receptor is a promising target for drugs to treat
Parkinson's disease
(PD), and the central blockade of adenosine A(1) receptor improves cognitive function. In the present study, we investigated the effect of a novel adenosine A(1) and A(2A) dual antagonist, 5-[5-amino-3-(4-fluorophenyl) pyrazin-2-yl]-1-isopropylpyridine-2(1H)-one (ASP5854), in animal models of PD and cognition. The binding affinities of ASP5854 for human A(1) and A(2A) receptors were 9.03 and 1.76 nM, respectively, with higher specificity and no species differences. ASP5854 also showed antagonistic action on A(1) and A(2A) agonist-induced increases of intracellular Ca(2+) concentration. ASP5854 ameliorated A(2A) agonist 2-[p-(2-carboxyethyl) phenethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680)- and haloperidol-induced catalepsy in mice, with the minimum effective doses of 0.32 and 0.1 mg/kg, respectively, and it also improved haloperidol-induced catalepsy in rats at doses higher than 0.1 mg/kg. In unilateral 6-hydroxydopamine-lesioned rats, ASP5854 significantly potentiated l-dihydroxyphenylalanine (L-DOPA)-induced rotational behavior at doses higher than 0.032 mg/kg. ASP5854 also significantly restored the striatal dopamine content reduced by 1-metyl-
4-phenyl-1,2,3,6-tetrahydropyridine
treatment in mice at doses higher than 0.1 mg/kg. Furthermore, in the rat passive avoidance test, ASP5854 significantly reversed the scopolamine-induced memory deficits, whereas the specific adenosine A(2A) antagonist 8-((E)-2-(3,4-dimethoxyphenyl)ethenyl)-1,3-diethyl-7-methyl-3,7-dihydro-1H-purine-2,6-dione (KW-6002; istradefylline) did not. Scopolamine- or 5H-dibenzo[a,d]cyclohepten-5,10-imine (dizocilpine maleate) (MK-801)-induced impairment of spontaneous alternation in the mouse Y-maze test was ameliorated by ASP5854, whereas KW-6002 did not exert improvement at therapeutically relevant dosages. These results demonstrate that the novel, selective, and orally active dual adenosine A(1) and A(2A) receptors antagonist ASP5854 improves motor impairments, is neuroprotective via A(2A) antagonism, and also enhances cognitive function through A(1) antagonism.
...
PMID:Pharmacological characterization of a novel, potent adenosine A1 and A2A receptor dual antagonist, 5-[5-amino-3-(4-fluorophenyl)pyrazin-2-yl]-1-isopropylpyridine-2(1H)-one (ASP5854), in models of Parkinson's disease and cognition. 1768 18
The nervous system-specific leucine-rich repeat Ig-containing protein LINGO-1 is associated with the Nogo-66 receptor complex and is endowed with a canonical EGF receptor (EGFR)-like tyrosine phosphorylation site. Our studies indicate that LINGO-1 expression is elevated in the substantia nigra of
Parkinson's disease
(PD) patients compared with age-matched controls and in animal models of PD after neurotoxic lesions. LINGO-1 expression is present in midbrain dopaminergic (DA) neurons in the human and rodent brain. Therefore, the role of LINGO-1 in cell damage responses of DA neurons was examined in vitro and in experimental models of PD induced by either oxidative (6-hydroxydopamine) or mitochondrial (N-methyl-
4-phenyl-1,2,3,6-tetrahydropyridine
) toxicity. In LINGO-1 knockout mice, DA neuron survival was increased and behavioral abnormalities were reduced compared with WT. This neuroprotection was accompanied by increased Akt phosphorylation (p-Akt). Similar neuroprotective in vivo effects on midbrain DA neurons were obtained in WT mice by blocking LINGO-1 activity using LINGO-1-Fc protein. Neuroprotection and enhanced neurite growth were also demonstrated for midbrain DA neurons in vitro. LINGO-1 antagonists (LINGO-1-Fc, dominant negative LINGO-1, and anti-LINGO-1 antibody) improved DA neuron survival in response to MPP+ in part by mechanisms that involve activation of the EGFR/Akt signaling pathway through a direct inhibition of LINGO-1's binding to EGFR. These results show that inhibitory agents of LINGO-1 activity can protect DA neurons against degeneration and indicate a role for the leucine-rich repeat protein LINGO-1 and related classes of proteins in the pathophysiological responses of midbrain DA neurons in PD.
...
PMID:Inhibition of the leucine-rich repeat protein LINGO-1 enhances survival, structure, and function of dopaminergic neurons in Parkinson's disease models. 1772 13
Most cases of
Parkinson's disease
(PD) are sporadic, suggesting an environmental influence on individuals affected by this neurodegenerative disorder. Environmental stresses often lead to changes in the regulation of splicing of pre-mRNA transcripts and this may lead to the pathogenesis of the disease. A 1-methyl-
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP)/probenecid mouse model was used to examine the changes in the splicing of the fosB and rgs9 transcripts. The ratio of DeltafosB/fosB transcript was decreased in the substantia nigra and unchanged in the striatum after acute MPTP treatment. The DeltafosB/fosB transcript ratio decreased initially and then increased in the striatum of chronically MPTP-treated animals due to different degrees of reduction for the splice variants over time, whereas the ratio was unchanged in the substantia nigra. The ratio of rgs9-2/rgs9-1 transcript decreased in the substantia nigra of mice after acute MPTP treatment and increased temporarily in the striatum after chronic MPTP treatment. There was an increase in the DeltaFosB/FosB and RGS9-2/RGS9-1 protein ratios 3 weeks and 3 days post-treatment, respectively, in chronically treated mice. The data indicate that the pattern of splice isoforms of fosB and rgs9 reflects the brain's immediate and long-term responses to the physiological stress associated with Parkinsonism.
...
PMID:MPTP administration in mice changes the ratio of splice isoforms of fosB and rgs9. 1793 34
Epidemiological evidence revealed that cigarette smokers and coffee drinkers have lower risk of
Parkinson's disease
(PD). Nicotine inhibits monoamine oxidase activity, and induces expression of neurotrophic factors and nicotinic acetylcholinergic receptors. However, caffeine is capable of antagonizing adenosine A(2A) receptor. Toxicant responsive enzymes and vesicular monoamine transporter-2 (VMAT-2) play critical roles in chemically induced PD. Despite some known functions, the effects of nicotine and caffeine on the expression and activity of toxicant responsive genes and on VMAT-2 are still not known. The study was therefore undertaken to investigate the effect of nicotine and caffeine on the expression and activity of toxicant responsive genes, i.e., CYP1A1, CYP2E1, GST-ya, GST-yc, GSTA4-4 and VMAT-2 in the striatum of control and MPTP-induced PD phenotype in mouse. The animals were treated intraperitoneally daily with nicotine (1 mg/kg) or caffeine (20 mg/kg) for 8 weeks, followed by 1-methyl
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP; 20 mg/kg)+nicotine or caffeine for 4 weeks. MPTP significantly attenuated CYP1A1 and VMAT-2, and augmented CYP2E1, GST-ya, GST-yc and GSTA4-4 expression/activity. Nicotine or caffeine-treated animals showed significant restoration against most of the MPTP-induced alterations. The results obtained thus suggest that nicotine and caffeine modulate MPTP-induced alterations in CYP1A1, CYP2E1, GST-ya, GST-yc, GSTA4-4 and VMAT-2 expression/activity.
...
PMID:Nicotine and caffeine-mediated modulation in the expression of toxicant responsive genes and vesicular monoamine transporter-2 in 1-methyl 4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease phenotype in mouse. 1837 8
Two cardinal features of
Parkinson's disease
(PD) pathophysiology are a loss of glutamatergic synapses paradoxically accompanied by an increased glutamatergic transmission to the striatum. The exact substrate of this increased glutamatergic drive remains unclear. The striatum receives glutamatergic inputs from the thalamus and the cerebral cortex. Using vesicular glutamate transporters (vGluTs) 1 and 2 as markers of the corticostriatal and thalamostriatal afferents, respectively, we examined changes in the synaptology and relative prevalence of striatal glutamatergic inputs in methyl-
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP)-treated monkeys using electron microscopic immunoperoxidase and confocal immunofluorescence methods. Our findings demonstrate that the prevalence of vGluT1-containing terminals is significantly increased in the striatum of MPTP-treated monkeys (51.9 +/- 3.5% to 66.5 +/- 3.4% total glutamatergic boutons), without any significant change in the pattern of synaptic connectivity; more than 95% of vGluT1-immunolabeled terminals formed axo-spinous synapses in both conditions. In contrast, the prevalence of vGluT2-immunoreactive terminals did not change after MPTP treatment (21.7 +/- 1.3% vs. 21.6 +/- 1.2% total glutamatergic boutons). However, a substantial increase in the ratio of axo-spinous to axo-dendritic synapses formed by vGluT2-immunoreactive terminals was found in the pre-caudate and post-putamen striatal regions of MPTP-treated monkeys, suggesting a certain degree of synaptic reorganization of the thalamostriatal system in parkinsonism. About 20% of putative glutamatergic terminals did not show immunoreactivity in striatal tissue immunostained for both vGluT1 and vGluT2, suggesting the expression of another vGluT in these boutons. These findings provide striking evidence that suggests a differential degree of plasticity of the corticostriatal and thalamostriatal system in PD.
...
PMID:Differential synaptic plasticity of the corticostriatal and thalamostriatal systems in an MPTP-treated monkey model of parkinsonism. 1838 Jun 66
Striatal mitochondrial proteins were investigated using proteomics in the 1-methyl
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP) mouse model of
Parkinson's disease
. Four proteins, 19S proteasome ATPase Rpt6 (19S Rpt6), Lectin-related nature killer cell receptor LY 49S, Zinc finger A20 domain containing 1, and the sodium channel-associated protein 1 isoform 2, were significantly decreased while alpha-synuclein was increased in MPTP-treated mice. The altered levels of 19S Rpt6 and alpha-synuclein were further verified by Western blot. Experiments using small interfering RNA (siRNA) showed that alpha-synuclein was increased by 50% in cultured striatal neurons when 19S Rpt6 was knocked down. Taken together, our results imply that a deficiency in 19S Rpt6 may be partially related to the MPTP-induced increase in alpha-synuclein in the striatum.
...
PMID:Striatal 19S Rpt6 deficit is related to alpha-synuclein accumulation in MPTP-treated mice. 1878 62
Deep brain stimulation (DBS), a surgical therapy for advanced
Parkinson's disease
(PD), is known to change neuronal activity patterns in the pallidothalamic circuit. Whether these effects translate to the motor cortex and, if so, how they might modulate the functional responses of individual neurons in primary motor cortex remains uncertain. A 1-methyl-
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP)-treated monkey was implanted with a DBS lead spanning internal and external segments of globus pallidus. During therapeutic stimulation (135 Hz) for rigidity and bradykinesia, neurons in primary motor cortex (M1) exhibited an inhibitory phase-locking (2-5 ms) to the stimulus, an overall decrease in mean discharge rate, and an increase in response specificity to passive limb movement. Sub-therapeutic DBS (30 Hz) still produced entrainment to the stimulation, but the mean discharge rate and specificity to movement were not changed. Lower stimulation intensities (at 135 Hz), which no longer improved motor symptoms, had little effect on M1 activity. These findings suggest that DBS improves parkinsonian motor symptoms by inducing global changes in firing pattern and rate along the pallido-thalamocortical sensorimotor circuit.
...
PMID:Pallidal stimulation that improves parkinsonian motor symptoms also modulates neuronal firing patterns in primary motor cortex in the MPTP-treated monkey. 1940 95
Aberrant mitochondrial function appears to play a central role in dopaminergic neuronal loss in
Parkinson's disease
(PD). 1-methyl-4-phenylpyridinium iodide (MPP(+)), the active metabolite of N-methyl-
4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP), is a selective inhibitor of mitochondrial complex I and is widely used in rodent and cell models to elicit neurochemical alterations associated with PD. Recent findings suggest that Glycogen Synthase Kinase-3beta (GSK-3beta), a critical activator of neuronal apoptosis, is involved in the dopaminergic cell death. In this study, the role of GSK-3beta in modulating MPP(+)-induced mitochondrial dysfunction and neuronal death was examined in vivo, and in two neuronal cell models namely primary cultured and immortalized neurons. In both cell models, MPTP/MPP(+) treatment caused cell death associated with time- and concentration-dependent activation of GSK-3beta, evidenced by the increased level of the active form of the kinase, i.e. GSK-3beta phosphorylated at tyrosine 216 residue. Using immunocytochemistry and subcellular fractionation techniques, we showed that GSK-3beta partially localized within mitochondria in both neuronal cell models. Moreover, MPP(+) treatment induced a significant decrease of the specific phospho-Tyr216-GSK-3beta labeling in mitochondria concomitantly with an increase into the cytosol. Using two distinct fluorescent probes, we showed that MPP(+) induced cell death through the depolarization of mitochondrial membrane potential. Inhibition of GSK-3beta activity using well-characterized inhibitors, LiCl and kenpaullone, and RNA interference, prevented MPP(+)-induced cell death by blocking mitochondrial membrane potential changes and subsequent caspase-9 and -3 activation. These results indicate that GSK-3beta is a critical mediator of MPTP/MPP(+)-induced neurotoxicity through its ability to regulate mitochondrial functions. Inhibition of GSK-3beta activity might provide protection against mitochondrial stress-induced cell death.
...
PMID:Involvment of cytosolic and mitochondrial GSK-3beta in mitochondrial dysfunction and neuronal cell death of MPTP/MPP-treated neurons. 1943 May 25
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