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)

The recent molecular cloning of BDNF and CNTF based on traditional protein purification and protein sequencing and the identification and cloning of NT-3 and NT-4 by homology cloning strategies has led to a tremendous flurry of interest in the biology of these proteins and initiation of studies to assess their potential utility in neurological disorders ranging through degenerative disease, stroke and ischemia, trauma and peripheral neuropathies. Tissue culture studies have been very useful in identifying neuronal specificities of the neurotrophins and CNTF and in combination with localization studies of these growth factors and their receptors have provided the basis for in vivo studies. Initial animal studies with BDNF indicate efficacy of BDNF in models of Alzheimer's and Parkinson's disease and small fiber sensory neuropathy. Studies with CNTF have similarly progressed from in vitro findings, especially the discovery that CNTF is a growth factor for motor neurons, to in vivo findings where CNTF has been shown to be effective in slowing symptoms of motor neuron dysfunction in three genetic models. Based on these positive animal data, CNTF is currently in clinical trials for the potential treatment of motor neuron disease or amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease.
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PMID:Neurotrophic growth factors and neurodegenerative diseases: therapeutic potential of the neurotrophins and ciliary neurotrophic factor. 783 3

Parkinson's disease is a prevalent neurological disease characterized by profound and incapacitating movement disorders. A common pathology in Parkinson's patients is degeneration of substantia nigra dopaminergic neurons that innervate the striatum and a corresponding decrease in striatal dopamine content. We now report that NT-4/5 can prevent the death of rat embryonic substantia nigra dopaminergic neurons in low density, enriched, primary cultures. Furthermore, these neurons express messenger RNA encoding the trkB receptor for NT-4/5 and transcripts for NT-4/5 are present in their environment. In addition, we demonstrate that NT-4/5 protects embryonic dopaminergic neurons from the toxic effects of the neurotoxin MPP+. Thus, NT-4/5 could be a physiological survival factor for midbrain dopaminergic neurons and may be useful as a therapeutic agent for Parkinson's disease.
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PMID:Neurotrophin-4/5 is a survival factor for embryonic midbrain dopaminergic neurons in enriched cultures. 790 42

Free radical formation is considered to be a major cause of dopaminergic (DAergic) cell death in the substantia nigra leading to Parkinson's disease (PD). In this study we employed several radical donors including iron and sodium nitroprusside to induce toxic effects on DAergic neurons cultured from the embryonic rat midbrain floor. Overall cell survival was assessed by assaying LDH, and DAergic neuron survival was monitored by counting tyrosine hydroxylase-positive cells. Our data suggest that the DAergic neuron population is about fourfold more susceptible to free-radical-mediated damage than the total population of midbrain neurons. Application of the neurotrophic factors GDNF and NT-4, for which DAergic neurons have specific receptors, prior to toxin administration protected these neurons from toxin-mediated death, which, fully or in part, occurs under the signs of apoptosis. These findings underscore the importance of GDNF and NT-4 in designing future therapeutical concepts for PD.
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PMID:GDNF and NT-4 protect midbrain dopaminergic neurons from toxic damage by iron and nitric oxide. 1078 44

Transplantation of embryonic dopaminergic neurons is an experimental therapy for Parkinson's disease, but limited tissue availability and suboptimal survival of grafted dopaminergic neurons impede more widespread clinical application. Glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-4/5 (NT-4/5) exert neurotrophic effects on dopaminergic neurons via different receptor systems. In this study, we investigated possible additive or synergistic effects of combined GDNF and NT-4/5 treatment on rat embryonic (embryonic day 14) nigral explant cultures grown for 8 days. Contrary to cultures treated with GDNF alone, cultures exposed to NT-4/5 and GDNF+NT-4/5 were significantly larger than controls (1.6- and 2.0-fold, respectively) and contained significantly more protein (1.6-fold). Treatment with GDNF, NT-4/5 and GDNF+NT-4/5 significantly increased dopamine levels in the culture medium by 1.5-, 2.5- and 4.7-fold, respectively, compared to control levels, and the numbers of surviving tyrosine hydroxylase-immunoreactive neurons increased by 1.7-, 2.1-, and 3.4-fold, respectively. Tyrosine hydroxylase enzyme activity was moderately increased in all treatment groups compared to controls. Counts of nigral neurons containing the calcium-binding protein, calbindin-D28k, revealed a marked increase in these cells by combined GDNF and NT-4/5 treatment. Western blots for neuron-specific enolase suggested an enhanced neuronal content in cultures after combination treatment, whereas the expression of glial markers was unaffected. The release of lactate dehydrogenase into the culture medium was significantly reduced for GDNF+NT-4/5-treated cultures only. These results indicate that combined treatment with GDNF and NT4/5 may be beneficial for embryonic nigral donor tissue either prior to, or in conjunction with, intrastriatal transplantation in Parkinson's disease.
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PMID:Additive effect of glial cell line-derived neurotrophic factor and neurotrophin-4/5 on rat fetal nigral explant cultures. 1173 60

Nerve growth factor was the first identified protein with anti-apoptotic activity on neurons. This prototypic neurotrophic factor, together with the three structurally and functionally related growth factors brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT3) and neurotrophin-4/5 (NT4/5), forms the neurotrophin protein family. Target T cells for neurotrophins include many neurons affected by neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and peripheral polyneuropathies. In addition, the neurotrophins act on neurons affected by other neurological and psychiatric pathologies including ischemia, epilepsy, depression and eating disorders. Work with cell cultures and animal models provided solid support for the hypothesis that neurotrophins prevent neuronal death. While no evidence exists that a lack of neurotrophins underlies the etiology of any neurodegenerative disease, these studies have spurred on hopes that neurotrophins might be useful symptomatic-therapeutic agents. However first clinical trials led to variable results and severe side effects were observed. For future therapeutic use of the neurotrophins it is therefore crucial to expand our knowledge about their physiological functions as well as their pharmacokinetic properties. A major challenge is to develop methods for their application in effective doses and in a precisely timed and localized fashion.
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PMID:Neurotrophins. 1257 26

Human neural progenitor cells (HNPCs) can be expanded in large numbers for significant periods of time to provide a reliable source of neural cells for transplantation in neurodegenerative disorders such as Parkinson's disease (PD). In the present study, HNPCs isolated from embryonic cortex were expanded as neurospheres in cell culture for 10 months. Just prior to transplantation, a proportion of the HNPCs were treated in a "predifferentiation" protocol in combination with the neurotropic factor NT4, in order to yield significant numbers of neurons. For transplantation, either undifferentiated HNPCs, or predifferentiated HNPCs were transplanted into the substantia nigra of a rat model of Parkinson's disease. At 12 weeks, there was good survival with proliferation of transplanted HNPCs occurring after transplantation but ceasing before the animals were sacrificed. Transplants of predifferentiated cells contained a higher proportion of neurons. The presence of a lesion in the striatum had a significant influence on the migration of transplanted cells from the substantia nigra into the striatum. There was no significant behavioural recovery or effect of transplanted HNPCs on the loss of dopaminergic cells from the host brain. In conclusion, HNPCs may provide a source of cells for use in the treatment of Parkinson's disease.
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PMID:Differentiation and migration of long term expanded human neural progenitors in a partial lesion model of Parkinson's disease. 1501 Mar 33

The survival of injured adult dopaminergic substantia nigra pars compacta neurons can be promoted by various neurotrophic factors. Most neurotrophic factor receptors are activated by intracellular tyrosine phosphorylation upon ligand binding and are subsequently inactivated or dephosphorylated by protein tyrosine phosphatases. This raised the possibility that tyrosine phosphatase inhibition might improve neuronal survival. Here, we infused the stable water-soluble tyrosine phosphatase-specific inhibitor, peroxovanadium [potassium bisperoxo(1,10-phenanthroline)oxovanadate (V) (bpV(phen))], for 14 days close to the substantia nigra starting immediately after a unilateral moderate injury by injection of the neurotoxin 6-hydroxydopamine (6-OHDA) into the midbrain of adult Sprague-Dawley rats. The dopaminergic nigrostriatal neurons were identified by retrograde tracing with fluorogold 7 days prior to the injury. With infusion of 3 or 10 microm peroxovanadium, 75% of these neurons survived compared to 45% in vehicle-infused rats. Degeneration of the dopaminergic projections to the neostriatum was also reduced by 10 microm peroxovanadium. Twenty minutes after an acute injection of peroxovanadium into the substantia nigra, increased tyrosine phosphorylation in Western blots of nigral extracts was seen in the same protein bands as after injections of brain-derived neurotrophic factor (BDNF) or NT-4. This suggests that peroxovanadium enhances endogenous neurotrophic signalling resulting in improved neuronal survival. The neuroprotective effects of this small molecule protein tyrosine phosphatase inhibitor represent a proof-of-principle for a novel treatment strategy in a model for Parkinson's disease.
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PMID:Protein tyrosine phosphatase inhibition reduces degeneration of dopaminergic substantia nigra neurons and projections in 6-OHDA treated adult rats. 1742 59

Neurotrophic factors comprise a broad family of secreted proteins that have growth promoting, survival promoting and differentiation inducing activities. Disruption of neurotrophic factor signalling is a characteristic of many central and peripheral nervous system disorders, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, stroke, and peripheral neuropathy and pain. It follows that treating patients with neurotrophic factors might be beneficial in a range of neurological diseases. However, the promising results seen in animal models of disease have not translated well into clinical trials due to the poor pharmacokinetics associated with the intact proteins, in particular, their short in vivo half-life, low blood brain barrier permeability, limited diffusion, and undesirable effects through multiple receptor interactions. This has been the main motivation for the design of small molecule modulators of the neurotrophic factor pathways. The review gives a brief survey of the various strategies to design mimetics that have been reported in the literature with special emphasis on the tandem repeat peptide agonist approach for BDNF/NT-4/5 and N-cadherin mimetics.
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PMID:Tandem repeat peptide strategy for the design of neurotrophic factor mimetics. 1828 37

Many neurodegenerative disorders share a common susceptibility to oxidative stress, including Alzheimer's, Parkinson Disease, Huntington Disease and Friedreich's ataxia. In a previous work, we proved that stem cell-conditioned medium increased the survival of cells isolated from Friedreich's ataxia patients, when submitted to oxidative stress. The aim of the present work is to confirm this same effect in dorsal root ganglia cells isolated from YG8 mice, a mouse model of Friedreich's ataxia. In this disorder, the neurons of the dorsal root ganglia are the first to degenerate. Also, in this work we cultured mesenchymal stem cells isolated from YG8 mice, in order to compare them with their wildtype counterpart. To this end, dorsal root ganglia primary cultures isolated from YG8 mice were exposed to oxidative stress and cultured with conditioned medium from either wildtype or YG8 stem cells. As a result, the conditioned medium increased the survival of the dorsal root ganglia cells. This coincided with an increase in oxidative stress-related markers and frataxin expression levels. BDNF, NT3 and NT4 trophic factors were detected in the conditioned medium of both wild-type and YG8 stem cells, all which bind to the various neuronal cell types present in the dorsal root ganglia. No differences were observed in the stem cells isolated from wildtype and YG8 mice. The results presented confirm the possibility that autologous stem cell transplantation may be a viable therapeutic approach in protecting dorsal root ganglia neurons of Friedreich's ataxia patients.
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PMID:Stem cells from wildtype and Friedreich's ataxia mice present similar neuroprotective properties in dorsal root ganglia cells. 2367 37

Experimental evidence has revealed the role of mitochondria in various aspects of neuronal physiology. Mitochondrial failure results in alterations that underlie the pathogeneses of many neurodegenerative disorders, such as Parkinson's disease, Alzheimer's disease, Huntington's disease (HD) and amyotrophic lateral sclerosis. The mitochondrial toxin 3-nitropropionic acid (3-NP) has been used to model failure; for example, systemic administration of 3-NP imitates the striatal degeneration that is exhibited in the postmortem tissue of patients afflicted with HD. We have demonstrated that low, sub-chronic doses of 3-NP are sufficient to initiate the damage to striatal neurons that is associated with changes in neurotrophin expression levels. However, the mechanisms underlying the alterations in neuronal activity and neurotransmission due to 3-NP-induced mitochondrial dysfunction remain to be elucidated. In this paper, we focus on how corticostriatal transmission and its modulation by neurotrophins are altered in vivo after 5 days of mitochondrial inhibition with 3-NP. Recordings of population spikes and a paired pulse (PP) stimulation protocol were used to document changes in corticostriatal synapses in 3-NP-treated brain slices. The corticostriatal synapses were modulated by neurotrophins but displayed differential amplitude increases in the presence of brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), or neurotrophin-4/5 (NT-4/5) under control conditions. Neurotrophin-mediated synaptic modulation was decreased in slices from 3-NP-treated mice. The protein and mRNA levels of neurotrophins and their receptors were also modified in the 3-NP-treated tissue. Neuronal structural evaluation demonstrated that synaptic length and density were reduced in the 3-NP-treated mice, which partially explained the changes in the amplitudes of the synaptic field responses. Our results demonstrate that corticostriatal synapses are differentially modulated by neurotrophins and that this modulation is altered by mitochondrial failure. Mitochondrial dysfunction also affects neurotransmitter release in corticostriatal synapses, neurotrophin availability, dendritic arborization and the lengths of the striatal medium spiny neurons (MSNs).
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PMID:In vivo mitochondrial inhibition alters corticostriatal synaptic function and the modulatory effects of neurotrophins. 2524 Oct 69


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