Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Parkinson's disease (PD) is associated with increased excitatory activity within the subthalamic nucleus (STN). We sought to inhibit STN output in hemiparkinsonian macaques by transfection with adeno-associated virus (AAV) containing the gene for glutamic acid decarboxylase (GAD). In total, 13 macaques were rendered hemiparkinsonian by right intracarotid 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injection. Seven animals were injected with AAV-GAD into the right STN, and six received an AAV gene for green fluorescent protein (GFP). Videotaped motor ratings were performed in a masked fashion on a weekly basis over a 55-week period. At 56 weeks, the animals were scanned with (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Histological examination was performed at the end of the study. No adverse events were observed after STN gene therapy. We found that the clinical rating scores for the two treatment groups had different patterns of change over time (group x time interaction, P<0.001). On FDG PET, the GAD animals exhibited an increase in glucose utilization in the right motor cortex relative to GFP controls (P<0.001). Metabolism in this region correlated with clinical ratings at end point (P<0.01). Histology confirmed GAD expression in treated animals. These findings suggest that STN AAV-GAD is well tolerated and potentially effective in a primate model of PD. The changes in motor cortical glucose utilization observed after gene therapy are consistent with the modulation of metabolic brain networks associated with this disorder.
J Cereb Blood Flow Metab 2007 Mar
PMID:Subthalamic glutamic acid decarboxylase gene therapy: changes in motor function and cortical metabolism. 1683 31

To investigate the effects of bilateral subthalamic nucleus (STN) stimulation on patterns of brain activation during random number generation (RNG), a task that requires suppression of habitual counting and response selection under competition. We used H(2)(15)O positron emission tomography to investigate the changes of regional cerebral blood flow (rCBF) induced by bilateral STN stimulation during a RNG task, in six patients with Parkinson's disease. Paced RNG at 1 Hz was compared with a control counting task. Both tasks were performed off medication with deep brain stimulation on and off. Subthalamic nucleus stimulation had a negative effect on performance of fast-paced RNG, leading to reduced randomness and increased habitual counting. Subthalamic nucleus stimulation also induced a reduction of rCBF in the left dorsal frontal gyrus, inferior frontal gyrus, dorsolateral prefrontal cortex, posterior and right anterior cingulate, and an increase of rCBF in the right internal globus pallidum (GPi) during RNG. Stimulation of the STN significantly altered pallidal coupling with frontal and temporal areas compared with when the stimulators were off. In conclusion, during RNG: (i) STN stimulation activates its output neurons to the GPi; (ii) STN stimulation induces increased inhibition of a prefrontal-cingulate network. This is the first direct evidence that STN stimulation significantly alters pallidal coupling with prefrontal, cingulate, and temporal cortices during performance of a task that requires response selection under competition.
J Cereb Blood Flow Metab 2007 Jun
PMID:STN stimulation alters pallidal-frontal coupling during response selection under competition. 1711 43

Cytidine 5'-diphosphocholine, CDP-choline, or citicoline is an essential intermediate in the biosynthetic pathway of structural phospholipids in cell membranes, particularly phosphatidylcholine. Following administration by both the oral and parenteral routes, citicoline releases its two main components, cytidine and choline. Absorption by the oral route is virtually complete, and bioavailability by the oral route is therefore approximately the same as by the intravenous route. Once absorbed, citicoline is widely distributed throughout the body, crosses the blood-brain barrier and reaches the central nervous system (CNS), where it is incorporated into the membrane and microsomal phospholipid fraction. Citicoline activates biosynthesis of structural phospholipids of neuronal membranes, increases brain metabolism, and acts upon the levels of different neurotransmitters. Thus, citicoline has been experimentally shown to increase norepinephrine and dopamine levels in the CNS. Owing to these pharmacological mechanisms, citicoline has a neuroprotective effect in hypoxic and ischemic conditions, decreasing the volume of ischemic lesion, and also improves learning and memory performance in animal models of brain aging. In addition, citicoline has been shown to restore the activity of mitochondrial ATPase and membrane Na+/K+ATPase, to inhibit activation of certain phospholipases, and to accelerate reabsorption of cerebral edema in various experimental models. Citicoline has also been shown to be able to inhibit mechanisms of apoptosis associated to cerebral ischemia and in certain neurodegeneration models, and to potentiate neuroplasticity mechanisms. Citicoline is a safe drug, as shown by the toxicological tests conducted, that has no significant systemic cholinergic effects and is a well tolerated product. These pharmacological characteristics and the action mechanisms of citicoline suggest that this product may be indicated for treatment of cerebral vascular disease, head trauma (HT) of varying severity, and cognitive disorders of different causes. In studies conducted in the treatment of patients with HT, citicoline was able to accelerate recovery from post-traumatic coma and neurological deficits, achieving an improved final functional outcome, and to shorten hospital stay in these patients. Citicoline also improved the mnesic and cognitive disorders seen after HT of minor severity that constitute the so-called post-concussional syndrome. In the treatment of patients with acute ischemic cerebral vascular disease, citicoline accelerates recovery of consciousness and motor deficit, achieves a better final outcome, and facilitates rehabilitation of these patients. The other major indication of citicoline is for treatment of senile cognitive impairment, either secondary to degenerative diseases (e.g. Alzheimer disease) or to chronic cerebral vascular disease. In patients with chronic cerebral ischemia, citicoline improves scores in cognitive rating scales, while in patients with senile dementia of the Alzheimer type it stops the course of disease, and neuroendocrine, neuroimmunomodulatory, and neurophysiological benefits have been reported. Citicoline has also been shown to be effective in Parkinson disease, drug addictions, and alcoholism, as well as in amblyopia and glaucoma. No serious side effects have occurred in any series of patients treated with citicoline, which attests to the safety of treatment with citicoline.
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PMID:Citicoline: pharmacological and clinical review, 2006 update. 1717 Nov 87

This is the first in vivo determination of the vesicular monoamine transporter (VMAT2) density (B(max)) and ligand-transporter affinity (K(d)(app)) in six unilaterally 6-hydroxydopamine (6-OHDA) lesioned rats using micro-positron emission tomography (PET) imaging with [(11)C]-(+)-alpha-dihydrotetrabenazine (DTBZ). A multiple ligand concentration transporter assay (MLCTA) was used to determine a B(max) value of 178+/-32 pmol/mL and a K(d)(app) of 47.7+/-9.3 pmol/mL for the non-lesioned side and 30.52+/-5.84 and 43.4+/-15.52 pmol/mL for the lesioned side, respectively. While B(max) was significantly different between the two sides, no significant difference was observed for the K(d)(app). In addition to demonstrating the feasibility of in vivo Scatchard analysis in rats, these data confirm the expectation that a 6-OHDA lesion does not affect the affinity; a much simpler binding potential (BP) measure can thus be used as a marker of lesion severity (LS) in this rat model of Parkinson's disease. A transporter occupancy curve demonstrated negligible transporter occupancy ( approximately 1%) at a specific activity (SA) of 1100 nCi/pmol (assuming an injected dose of 100 microCi/100 g), while 10% occupancy was estimated at 100 nCi/pmol. An indirect measurement indicated that the degree of occupancy as a function of SA is independent of LS. Finally, BP measurement reproducibility was assessed and found to be 11%+/-7% for the healthy and 8%+/-12% for the lesioned side. Quantitative PET results can thus be obtained even for severely lesioned animals with the striatum on one side not clearly visible provided accurate image analysis methods are used.
J Cereb Blood Flow Metab 2007 Jul
PMID:In vivo measurement of density and affinity of the monoamine vesicular transporter in a unilateral 6-hydroxydopamine rat model of PD. 1724 18

Micro-positron emission tomography imaging studies were conducted to characterize modulation of metabotropic glutamate subtype-5 receptor (mGluR5) function in a 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson's disease using four analogical PET ligands: 2-[(11)C]methyl-6-(2-phenylethynyl) pyridine ([(11)C]MPEP), 2-(2-(3-[(11)C]methoxyphenyl)ethynyl)pyridine ([(11)C]M-MPEP), 2-(2-(5-[(11)C]methoxypyridin-3-yl)ethynyl)pyridine ([(11)C]M-PEPy), and 3-[(2-[(18)F]methyl-1,3-thiazol-4-yl)ethynyl]pyridine ([(18)F]M-TEP). A total of 45 positron emission tomography (PET) imaging studies were conducted on nine male Sprague-Dawley rats within 4 to 6 weeks after unilateral 6-OHDA lesioning into the right medial forebrain bundle. The severity of the lesion was determined with [(11)C]CFT ([(11)C]2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane), a specific and sensitive ligand for imaging dopamine transporter function. The binding potential (BP) images were processed on pixel-by-pixel basis by using a method of the distribution volume ratio with cerebellum as a reference tissue. The values for BP were determined on striatum, hippocampus, and cortex. [(11)C]CFT binding was decreased on the lesioned (right) striatum by 35.4%+/-13.4% compared with the intact left striatum, indicating corresponding loss of presynaptic dopamine terminals. On the same areas of the lesioned striatum, three of the four tested mGluR5 ligands showed enhanced binding characteristics. The average differences between the right and left striatum were 4.4%+/-6.5% (P<0.05) with [(11)C]MPEP, -0.1%+/-1.7% (P>0.05) with [(11)C]M-MPEP, 3.9%+/-4.6% (P<0.05) with [(11)C]M-PEPy, and 6.6%+/-2.7% (P>0.05) with [(18)F]M-TEP. The enhanced binding was also observed in the right hippocampus and cortex. These studies showed that glutamatergic neurotransmission might have a complementary role in dopaminergic degeneration, which can be evaluated by in vivo PET imaging.
J Cereb Blood Flow Metab 2007 Sep
PMID:Evaluation of four pyridine analogs to characterize 6-OHDA-induced modulation of mGluR5 function in rat brain using microPET studies. 1729 51

Reactive oxygen species (ROS) is massively produced in the brain after cerebral ischemia and reperfusion. It reacts strongly with cellular components, which has detrimental effects and leads to neuronal cell death. DJ-1, which was found to be the causative gene of familial Parkinson's disease PARK7, is a multifunction protein, which plays a key role in transcriptional regulation, and a molecular chaperone. In this study, we investigated the neuroprotective effect of DJ-1 against neurodegeneration caused by ischemia/reperfusion injury. Cerebral ischemia was induced in rats by 120 mins of middle cerebral artery occlusion (MCAO) using an intraluminal introduction method. The intrastriatal injection of recombinant glutathione S-transferase-tagged human DJ-1 (GST-DJ-1) markedly reduced infarct size in 2,3,5-triphenyltetrazolium chloride staining at 3 days after MCAO. In addition, we performed a noninvasive evaluation of ischemic size using magnetic resonance imaging and found a significant reduction of infarct size with the administration of GST-DJ-1. In GST-DJ-1-treated rats, behavioral dysfunction and nitrotyrosine formation were significantly inhibited. Furthermore, GST-DJ-1 markedly inhibited H(2)O(2)-mediated ROS production in SH-SY5Y cells. These results indicate that GST-DJ-1 exerts a neuroprotective effect by reducing ROS-mediated neuronal injury, suggesting that DJ-1 may be a useful therapeutic target for ischemic neurodegeneration.
J Cereb Blood Flow Metab 2008 Mar
PMID:DJ-1 protects against neurodegeneration caused by focal cerebral ischemia and reperfusion in rats. 1788 63

Postmortem data indicate loss of serotoninergic neurons in Parkinson's disease (PD). We used the serotonin transporter (SERT) radioligand 3-amino-4-(2-dimethylaminomethyl-phenylsulfaryl)-benzonitril (DASB) and positron emission tomography to examine SERT distribution and changes in early PD subjects. We studied five PD subjects (H&Y 1 to 2.5) and eight normal controls. There is reduced SERT binding in PD. The magnitude of DASB binding reductions was greater in the forebrain than in the brainstem regions. There was no asymmetry of diminished SERT binding. DASB binding in the medulla was relatively spared, inconsistent with the description of early prominent pathologic study in these caudal brainstem nuclei.
J Cereb Blood Flow Metab 2008 Mar
PMID:Spared caudal brainstem SERT binding in early Parkinson's disease. 1807 72

Abnormal cerebral energy metabolism owing to dysfunction of mitochondrial electron transport has been implicated in the pathogenesis of Parkinson's disease (PD). However, in vivo data of mitochondrial dysfunction have been inconsistent. We directly investigated mitochondrial oxidative metabolism in vivo in 12 patients with early, never-medicated PD and 12 age-matched normal controls by combined measurements of the cerebral metabolic rate of oxygen (CMRO(2)) and the cerebral metabolic rate of glucose (CMRglc) with positron emission tomography. The primary analysis showed a statistically significant 24% increase in bihemispheric CMRO(2) and no change in CMRO(2)/CMRglc. These findings are inconsistent with a defect in mitochondrial oxidative phosphorylation owing to reduced activity of the mitochondrial electron transport system (ETS). Because PD symptoms were already manifest, deficient energy production owing to a reduced activity of the mitochondrial ETS cannot be a primary mechanism of neuronal death in early PD. Alternatively, this general increase in CMRO(2) could be due not to an increased metabolic demand but to an uncoupling of ATP production from oxidation in the terminal stage of oxidative phosphorylation. Whether this is the case in early PD and whether it is important in the pathogenesis of PD will require further study.
J Cereb Blood Flow Metab 2008 Oct
PMID:Cerebral mitochondrial metabolism in early Parkinson's disease. 1857 58

Continuous stimulation of the globus pallidus (GP) has been shown to be an effective treatment for Parkinson's disease (PD). We used the fact that the implanted quadripolar leads contain electrodes within the GPi and GPe to investigate the clinical effects of acute high-frequency stimulation applied in these nuclei and changes in regional cerebral blood flow (rCBF) as an index of synaptic activity. In five patients treated by chronic GP stimulation, we compared the effects on PD symptoms and the changes in rCBF at rest and during paced right-hand movements, with and without left GPe or GPi stimulation. Although improving contralateral rigidity and akinesia, left GPe stimulation decreased rCBF in the left cerebellum and lateral premotor cortex at rest and significantly increased it in the left primary sensorimotor cortex (SM1) during movement. In contrast, left ventral GPi stimulation, which improved rigidity and worsened akinesia, decreased rCBF in the left SM1, premotor area, anterior cingulum, and supplementary motor area but did not modify the movement-related activation. GPe stimulation seems to result in a reduced activity of motor-related areas and the facilitation of motor cortex activation during movement, the latter component being absent during GPi stimulation, and this may explain the observed worsening of akinesia.
J Cereb Blood Flow Metab 2009 Feb
PMID:Contrasting changes in cortical activation induced by acute high-frequency stimulation within the globus pallidus in Parkinson's disease. 1878 Nov 62

High-frequency stimulation of around 130 Hz delivered to the subthalamic nucleus (STN-DBS [deep brain stimulation]) is an effective treatment of Parkinson's disease (PD), but the mechanisms of its therapeutic effect remain obscure. Recently, it has been shown in anaesthetized rats that STN-DBS antidromically activates cortical neurons with coincident reduction of the cortical slow wave oscillations that occur in this preparation. Here we extend this work; recording the effect of STN-DBS upon cortical EEG and akinesia, in unanesthetized rats rendered cataleptic by acute dopaminergic blockade. STN-DBS-like stimulation resulted in a short latency, presumed antidromic, evoked potential in the cortex. In cataleptic animals, there was a significant increase in the power of beta oscillations in the electroencephalography which was reversed by stimulation that evoked the cortical response. We also observed a significant rescue of motor function, with the level of akinesia (bar test score) being inversely correlated to the amplitude of the evoked potential (R2 = 0.84). These data confirm that (probably antidromic) short latency cortical responses occur in the awake animal and that these are associated with reductions in abnormal cortical oscillations characteristic of PD and with improvements in akinesia. Our results raise the possibility that STN-DBS reduces PD oscillations and symptoms through antidromic cortical activation.
Cereb Cortex 2009 May
PMID:Cortical effects of subthalamic stimulation correlate with behavioral recovery from dopamine antagonist induced akinesia. 1878 34


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