g(m1)-ganglioside and Parkinson-Disease

GM1 is one of the main gangliosides of the nervous system, and it exerts neurotrophic and neuroprotective properties in neurons. It is involved in many processes necessary for the correct physiology of neuronal cells. In particular, it is necessary for the activity of neuronal receptors that control processes such as differentiation, survival, and mitochondrial activity. A shortage of GM1 in the substantia nigra is potentially responsible for the neurodegeneration present in Parkinson's disease patients. In this review, I report on the role played by GM1 in neurons and how its genetic shortage may be responsible for the onset of Parkinson's disease.

Topics: Brain; G(M1) Ganglioside; Gangliosides; Humans; Neurons; Parkinson Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting millions of patients worldwide. Many therapeutics are available for treating PD symptoms but there is no disease-modifying therapeutic that has been unequivocally shown to slow or stop the progression of the disease. There are several factors contributing to the failure of many putative disease-modifying agents in clinical trials and these include the choice of patients and clinical trial designs for disease modification trials. Perhaps more important, however, is the choice of therapeutic, which for the most part, has not taken into account the multiple and complex pathogenic mechanisms and processes involved in PD. This paper discusses some of the factors contributing to the lack of success in PD disease-modification trials, which have mostly investigated therapeutics with a singular mechanism of action directed at one of the many PD pathogenic processes, and suggests that an alternative strategy for success may be to employ multi-functional therapeutics that target multiple PD-relevant pathogenic mechanisms. Evidence is presented that the multi-functional glycosphingolipid GM1 ganglioside may be just such a therapeutic.

Topics: G(M1) Ganglioside; Gangliosides; Glycosphingolipids; Humans; Parkinson Disease

GM1 is a crucial component of neuronal membrane residing both in the soma and nerve terminals. As reported in Parkinson's disease patients, the reduction of GM1 determines the failure of fundamental functional processes leading to cumulative cell distress up to neuron death. This review reports on the role of GM1 in the pathogenesis of the disease, illustrating the current data available but also hypotheses on the additional mechanisms in which GM1 could be involved and which require further study. In the manuscript we discuss these points trying to explain the role of diminished content of brain GM1, particularly in the nigro-striatal system, in Parkinson's disease etiology and progression.

Topics: Brain; G(M1) Ganglioside; Humans; Neurons; Parkinson Disease

We have endeavored in this review to summarize our findings, which point to a systemic deficiency of ganglioside GM1 in Parkinson's disease (PD) tissues. These include neuronal tissues well known to be involved in PD, such as substantia nigra of the brain and those of the peripheral nervous system, such as the colon and heart. Moreover, we included skin and fibroblasts in the study as well as peripheral blood mononuclear cells; these are tissues not directly involved in neuronal signaling. We show similar findings for ganglioside GD1a, which is the metabolic precursor to GM1. We discuss the likely causes of these GM1 deficiencies and the resultant biochemical mechanisms underlying loss of neuronal viability and normal functioning. Strong support for this hypothesis is provided by a mouse PD model involving partial GM1 deficiency based on mono-allelic disruption of the B4galnt1 gene. We point out that progressive loss of GM1/GD1a occurs in the periphery as well as the brain, thus obviating the need to speculate PD symptom transfer between these tissues. Finally, we discuss how these findings point to a potential disease-altering therapy for PD:GM1 replacement, as is strongly implicated in animal studies and clinical trials.

Topics: Animals; Disease Models, Animal; G(M1) Ganglioside; Leukocytes, Mononuclear; Mice; Parkinson Disease; Substantia Nigra

Parkinson's disease (PD) is slowly progressing neurodegenerative disorder that affects millions of patients worldwide. While effective symptomatic therapies for PD exist, there is no currently available disease modifying agent to slow or stop the progression of the disease. Many years of research from various laboratories around the world have provided evidence in favor of the potential ability of GM1 ganglioside to be a disease modifying agent for PD. In this paper, information supporting the use of GM1 as a disease modifying therapeutic for PD is reviewed along with information concerning the role that deficiencies in GM1 ganglioside (and potentially other important brain gangliosides) may play in the pathogenesis of PD.

Topics: G(M1) Ganglioside; Gangliosides; Humans; Parkinson Disease

Tremor, akinesia, rigidity and postual instability are key signs of Parkinson's disease. The most important one is akinesia, which includes decreased spontaneous locomotor activity, slowness of movement, awkwardness and freezing. On the other hand, an electrical focal lesion in the brain, neurotoxin to dopaminergic neurons such as 6-hydroxydopamine (6-OHDA) or I-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP), cholinomimetic tremorogenic agents such as oxotremorine or tremorine, monoamine depleting agents such as reserpine or tetrabenazine, or dopamine receptor antagonists such as haloperidol are applied to render animal parkinsonism. The estimation of locomotor activity can be done accurately in animal models. Tremor can be studied using the animals treated by cerebral focal lesion, neurotoxins or cholinomimetics. Skillfulness is hard to estimate in animals, however, it can be done in primates. Freezing appeared in patients with levodopa treatment over a long period. This is a specific motor sign in Parkinson's disease, and cannot be observed in animals. Supplementing dopamine by levodopa administration, retarding the metabolism of levodopa or dopamine by dopa decarboxylase inhibitor (DCI), monoamine oxidase inhibitor type B (MAO-B) inhibitor or catechol-O-methyltransferase (COMT) inhibitor, dopamine receptor agonists, anticholinergic agents, dopamine release enhancer/ uptake inhibitor, N-methyl-D-aspartate (NMDA) receptor antagonists, adenosine receptor antagonists, neurotrophic factors, GM1-ganglioside and nicotinic receptor agonists have been applied in the treatment of Parkinson's disease or are under investigation for patients. Agents to facilitate nerve growth or to inhibit the degeneration of nerves will be developed in the future.

Topics: Animals; Antiparkinson Agents; Cholinergic Antagonists; Disease Models, Animal; Dopamine Agents; G(M1) Ganglioside; Nerve Growth Factors; Nerve Tissue Proteins; Nicotinic Agonists; Parkinson Disease; Purinergic P1 Receptor Antagonists; Receptors, Dopamine; Receptors, N-Methyl-D-Aspartate

A large body of experimental data suggests that neurotrophic molecules and/or substances that facilitate their action could be pharmaceutical agents for neurodegenerative pathologies. In particular, it has been demonstrated that nerve growth factor (NGF) exerts a physiological role for forebrain cholinergic neurons, while brain-derived neurotrophic factor (BDNF) seems to play a relevant role in rescuing dopaminergic neurons following damage. In addition, gangliosides are reported to potentiate neurotrophic factor effects in vitro as well as in vivo. In this study we examined the effects of the monosialoganglioside GM1 in different experimental models. The responsiveness of forebrain cholinergic neurons following NGF +/- GM1 was evaluated by assessing choline acetyltransferase (ChAT) activity in hippocampus, septal area and striatum of behaviorally impaired 24-month-old rats. NGF was intracerebroventricularly (i.c.v.) infused for 2 weeks while GM1 was given systemically for 3 weeks, starting from the beginning of NGF infusion. Moreover, the possible protective effects of GM1 were assessed following exposure of cultured cerebellar granule cells and dopaminergic mesencephalic neurons to different doses of 6-OH-DOPA, a metabolite of the dopamine pathway which has excitotoxic properties and has been hypothesized to participate in the pathology of Parkinson's disease. GM1 treatment to aged rats was seen to potentiate the NGF-induced increase of ChAT activity in the striatum ipsilateral to the NGF infusion. Moreover, in the striatum contralateral to the NGF infusion, GM1 increased ChAT activity above the control values, whereas NGF treatment alone did not affect enzymatic activity. GM1 treatment of cerebellar granule cells and mesencephalic neurons counteracted the dose- and time-dependent neurotoxicity of 6-OH-DOPA. These data support the notion that GM1 might prove useful in treating those pathological conditions where trophic factor deficits and/or excitotoxin-related toxicity play an important role.

Topics: Aging; Alzheimer Disease; Animals; Brain; Cerebral Ventricles; Choline O-Acetyltransferase; G(M1) Ganglioside; Humans; Injections, Intraventricular; Nerve Growth Factors; Organ Specificity; Parkinson Disease

GM1 ganglioside has been suggested as a treatment for Parkinson's disease (PD), potentially having symptomatic and disease modifying effects. The current pilot imaging study was performed to examine effects of GM1 on dopamine transporter binding, as a surrogate measure of disease progression, studied longitudinally.. Positron emission tomography (PET) imaging data were obtained from a subset of subjects enrolled in a delayed start clinical trial of GM1 in PD [1]: 15 Early-start (ES) subjects, 14 Delayed-start (DS) subjects, and 11 Comparison (standard-of-care) subjects. Treatment subjects were studied over a 2.5 year period while Comparison subjects were studied over 2 years. Dynamic PET scans were performed over 90 min following injection of [(11)C]methylphenidate. Regional values of binding potential (BPND) were analyzed for several striatal volumes of interest.. Clinical results for this subset of subjects were similar to those previously reported for the larger study group. ES subjects showed early symptomatic improvement and slow symptom progression over the study period. DS and Comparison subjects were initially on the same symptom progression trajectory but diverged once DS subjects received GM1 treatment. Imaging results showed significant slowing of BPND loss in several striatal regions in GM1-treated subjects and in some cases, an increased BPND in some striatal regions was detected after GM1 use.. Results of this pilot imaging study provide additional data to suggest a potential disease modifying effect of GM1 on PD. These results need to be confirmed in a larger number of subjects.

Topics: Adult; Aged; Aged, 80 and over; Antiparkinson Agents; Carbon Isotopes; Corpus Striatum; Dopamine Plasma Membrane Transport Proteins; Dopamine Uptake Inhibitors; Female; Follow-Up Studies; G(M1) Ganglioside; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Methylphenidate; Middle Aged; Parkinson Disease; Pilot Projects; Positron-Emission Tomography; Protein Binding; Time Factors

The present single center, double-blind, delayed start study was conducted to examine possible symptomatic and disease-modifying effects of GM1 ganglioside in Parkinson's disease (PD). Seventy-seven subjects with PD were randomly assigned to receive GM1 for 120 weeks (early-start group) or placebo for 24 weeks followed by GM1 for 96 weeks (delayed-start group). Washout evaluations occurred at 1 and 2 years after the end of treatment. Seventeen additional subjects who received standard-of-care were followed for comparative information about disease progression. Primary outcome was change from baseline Unified Parkinson's Disease Rating Scale (UPDRS) motor scores. At week 24, the early-start group had significant improvement in UPDRS motor scores vs. a significant worsening of scores in the delayed-start group. The early-start group also showed a sustained benefit vs. the delayed-start group at week 72 and at week 120. Both groups had significant symptom worsening during washout. This study provides evidence that GM1 use for 24 weeks was superior to placebo for improving motor symptoms and that extended GM1 use (up to 120 weeks) resulted in a lower than expected rate of symptom progression. The data from this small study suggest that GM1 may have symptomatic and potentially disease modifying effects on PD.

Topics: Analysis of Variance; Antiparkinson Agents; Disease Progression; Dopamine Agonists; Double-Blind Method; Female; Follow-Up Studies; G(M1) Ganglioside; Humans; Male; Middle Aged; Neuropsychological Tests; Parkinson Disease; Treatment Outcome

Previous work demonstrated that short-term (i.e., 16 weeks) use of GM1 ganglioside resulted in significant symptom reduction in Parkinson's disease (PD) patients. As GM1 use may have long-term benefit for PD patients, the present study was conducted to evaluate the long-term safety and efficacy of GM1 in PD patients. Twenty-six patients who concluded a previous randomized double blind placebo controlled trial of GM1 volunteered for this open-extension study. At the end of 5 years of GM1 use, patients generally had lower Unified Parkinson's Disease Rating Scale (UPDRS) motor scores (assessed during a practically defined "off" period) than at baseline prior to randomization into the original study. A similar result was found for UPDRS Activities of Daily Living scores. Performance of timed motor tests also remained mostly stable over the 5 year observation period. No consistent clinically significant changes in blood chemistry, hematologic indices or urine chemistry were noted over the course of this study. These results suggest that long-term GM1 use by PD patients is safe and may provide some clinical benefit for PD patients. Additional study is required to more completely assess the degree to which GM1 treatment may be a symptomatic and/or disease-modifying agent for treatment of PD.

Topics: Activities of Daily Living; Aged; Female; G(M1) Ganglioside; Humans; Male; Middle Aged; Motor Activity; Parkinson Disease; Regression Analysis; Severity of Illness Index; Treatment Outcome

To determine whether anti-GM1 antibodies are increased in Parkinson's disease (PD).. Serum immunoglobulin M (IgM) and IgG anti-GM1 antibodies were detected by enzyme-linked immunosorbent assay (ELISA) in 147 patients with PD and in 186 age-matched normal control subjects. Sera were assayed at initial dilution of 1:800 for IgM and 1:200 for IgG and were considered positive at absorbance values exceeding the value of 0.05 for IgM and 0.1 for IgG.. Forty patients with PD (27.2%) had sera positive for IgM anti-GM1 antibodies, whereas only five normal controls (2.7%) resulted positive (P < 0.0001). Most of patients (75%) with positive sera had a tremor-dominant form of PD. Only two patients with PD (1.4%) and none of normal controls had sera positive for IgG anti-GM1 antibodies.. A consistent portion of parkinsonians, mainly with a tremor-dominant form of PD, may have increased circulating IgM anti-GM1 antibodies.

Topics: Aged; Autoantibodies; Enzyme-Linked Immunosorbent Assay; Female; G(M1) Ganglioside; Humans; Immunoglobulin G; Immunoglobulin M; Male; Middle Aged; Parkinson Disease; Reference Values; Serologic Tests; Tremor

Studies in animal models of Parkinson's disease (PD) suggest that GM1 ganglioside treatment can restore neurologic and dopaminergic function. In view of positive preclinical findings and the results of a previous open-label study demonstrating efficacy of GM1 in PD patients, this study compared effects of GM1 ganglioside and placebo on motor functions in PD patients.. Forty-five patients with mild to moderate PD were studied. The primary efficacy measure was change in the Unified Parkinson's Disease Rating Scale (UPDRS) motor score. After three independent baseline assessments, patients received IV infusion of the test drug (1,000 mg GM1 or placebo) and then self-administered either GM1 or placebo twice daily (200 mg/day, subcutaneously) for 16 weeks. Patients were examined during monthly follow-up visits.. There was a significant difference between groups in UPDRS motor scores at 16 weeks (p=0.0001). The activities of daily living portion of the UPDRS (off-period assessment) also showed a significant effect in favor of the GM1-treated patients (p=0.04). GM1-treated patients also had significantly greater mean improvements than placebo-treated patients in performance of timed motor tests including tests of arm, hand, and foot movements, and walking. GM1 was well tolerated and no serious adverse events were reported.. This study demonstrates that GM1 ganglioside treatment enhances neurologic function significantly in PD patients. Further study is warranted to evaluate long-term effects of GM1 in PD patients and to elucidate further the mechanisms underlying patient improvements.

Topics: Activities of Daily Living; Adult; Aged; Double-Blind Method; Female; G(M1) Ganglioside; Humans; Infusions, Intravenous; Male; Middle Aged; Movement; Parkinson Disease; Placebos; Prospective Studies; Psychomotor Performance; Severity of Illness Index; Walking

Since the early 1980s, numerous studies have been reported by laboratories around the world documenting the beneficial effects of GM1 ganglioside treatment on the damaged dopamine system in various animal and in vitro models. Based on the strength of these data, the first clinical studies designed to assess the efficacy and safety of chronic GM1 use in the treatment of Parkinson's disease were performed. In a double-blind placebo-controlled study, significant improvements in GM1-treated patients were demonstrated in clinical motor ratings, timed tests of motor function, activities of daily living, and some aspects of neuropsychological functioning. Patients who have elected to continue using GM1 in an open extension trial have either continued to improve over time or have shown initial functional improvements and their disease has remained stable (i.e., no symptom progression) after two years. These results suggest that long-term use of GM1 is safe and may work to partially reverse the degenerative process in established Parkinson's disease patients.

Topics: Adult; Aged; Antiparkinson Agents; Double-Blind Method; Follow-Up Studies; G(M1) Ganglioside; Humans; Middle Aged; Motor Activity; Parkinson Disease; Placebos; Time Factors

We performed an open-label study testing the effects of GM1 ganglioside on 10 Parkinson's disease (PD) patients. Patients received 1,000 mg of GM1 by IV infusion after the last of three baseline functional assessments. Patients then self-administered GM1 at a dose of 200 mg/d, by subcutaneous injection, for 18 weeks. Under these conditions, GM1 ganglioside proved to be safe and well tolerated. There were no serious adverse events and none of the patients developed elevated anti-GM1 antibody titers. Improvements on at least some functional measures were present in most patients, beginning after 4 to 8 weeks of GM1 treatment. When functional improvements occurred, they lasted for the duration of the study. These results suggest that GM1 ganglioside is well tolerated and may be a useful adjunct to the treatment of PD, and that a double-blind, placebo-controlled study is now warranted.

Topics: Activities of Daily Living; Aged; Drug Evaluation; Female; G(M1) Ganglioside; Humans; Male; Middle Aged; Motor Activity; Parkinson Disease; Pilot Projects

Topics: Dose-Response Relationship, Drug; Drug Administration Schedule; G(M1) Ganglioside; Humans; Hyperlipidemias; Iatrogenic Disease; Infusions, Parenteral; Parkinson Disease

The main purpose of this chapter is to summarize the chief findings on ganglioside changes/interactions with some of the neurodegenerative disorders. For the latter we have focused on three diseases that have seen especially intensive study in that regard: Parkinson's, Alzheimer's, and Huntington's diseases. Parkinson's disease (PD) has received the most intensive study with revelation of systemic deficiency of GM1 in brain and all peripheral tissues that have been analyzed to date; this pointed to GM1 replacement as a promising therapy which proved only partially successful when tried for reasons that are discussed. Huntington's disease resembles PD in also manifesting GM1 deficiency, which did, however, respond to GM1 replacement therapy - apparently due to GM1 being administered directly into the brain. Alzheimer's disease was more complex in relation to gangliosides, with b-series (GD1b, GT1b) apparently depressed along with a-series. GM1 administered in brain appeared to induce improvement, but in a limited number of patients. We summarize studies showing why GM1 is of critical importance in neuronal function, and we also briefly point to a few additional neurological disorders in which one or more ganglioside changes have been implicated.

Topics: Alzheimer Disease; G(M1) Ganglioside; Gangliosides; Humans; Neurodegenerative Diseases; Parkinson Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting the body and mind of millions of people in the world. As PD progresses, bradykinesia, rigidity, and tremor worsen. These motor symptoms are associated with the neurodegeneration of dopaminergic neurons in the substantia nigra. PD is also associated with non-motor symptoms, including loss of smell (hyposmia), sleep disturbances, depression, anxiety, and cognitive impairment. This broad spectrum of non-motor symptoms is in part due to olfactory and hippocampal dysfunctions. These non-motor functions are suggested to be linked with adult neurogenesis. We have reported that ganglioside GD3 is required to maintain the neural stem cell (NSC) pool in the subventricular zone (SVZ) of the lateral ventricles and the subgranular layer of the dentate gyrus (DG) in the hippocampus. In this study, we used nasal infusion of GD3 to restore impaired neurogenesis in A53T alpha-synuclein-expressing mice (A53T mice). Intriguingly, intranasal GD3 administration rescued the number of bromodeoxyuridine + (BrdU +)/Sox2 + NSCs in the SVZ. Furthermore, the administration of gangliosides GD3 and GM1 increases doublecortin (DCX)-expressing immature neurons in the olfactory bulb, and nasal ganglioside administration recovered the neuronal populations in the periglomerular layer of A53T mice. Given the relevance of decreased ganglioside on olfactory impairment, we discovered that GD3 has an essential role in olfactory functions. Our results demonstrated that intranasal GD3 infusion restored the self-renewal ability of the NSCs, and intranasal GM1 infusion promoted neurogenesis in the adult brain. Using a combination of GD3 and GM1 has the potential to slow down disease progression and rescue dysfunctional neurons in neurodegenerative brains.

Topics: Administration, Intranasal; alpha-Synuclein; Animals; Dopaminergic Neurons; G(M1) Ganglioside; Gangliosides; Mice; Neurogenesis; Olfactory Bulb; Parkinson Disease

Fibrillary aggregated α-synuclein represents the neurologic hallmark of Parkinson's disease and is considered to play a causative role in the disease. Although the causes leading to α-synuclein aggregation are not clear, the GM1 ganglioside interaction is recognized to prevent this process. How GM1 exerts these functions is not completely clear, although a primary role of its soluble oligosaccharide (GM1-OS) is emerging. Indeed, we recently identified GM1-OS as the bioactive moiety responsible for GM1 neurotrophic and neuroprotective properties, specifically reverting the parkinsonian phenotype both in in vitro and in vivo models. Here, we report on GM1-OS efficacy against the α-synuclein aggregation and toxicity in vitro. By amyloid seeding aggregation assay and NMR spectroscopy, we demonstrated that GM1-OS was able to prevent both the spontaneous and the prion-like α-synuclein aggregation. Additionally, circular dichroism spectroscopy of recombinant monomeric α-synuclein showed that GM1-OS did not induce any change in α-synuclein secondary structure. Importantly, GM1-OS significantly increased neuronal survival and preserved neurite networks of dopaminergic neurons affected by α-synuclein oligomers, together with a reduction of microglia activation. These data further demonstrate that the ganglioside GM1 acts through its oligosaccharide also in preventing the α-synuclein pathogenic aggregation in Parkinson's disease, opening a perspective window for GM1-OS as drug candidate.

Topics: alpha-Synuclein; G(M1) Ganglioside; Humans; Oligosaccharides; Parkinson Disease

This study attempts to answer the question of whether mice with biallelic and monoallelic disruption of the St3gal5 (GM3 synthase) gene might benefit from GM1 replacement therapy. The GM3 produced by this sialyltransferase gives rise to downstream GD3 and the ganglio-series of gangliosides. The latter includes the a-series (GM1 + GD1a), which has proved most essential for neuron survival and function (especially GM1, for which GD1a provides a reserve pool). These biallelic mice serve as a model for children with this relatively rare autosomal recessive condition (ST3GAL5-/-) who suffer rapid neurological decline including motor loss, intellectual disability, visual and hearing loss, failure to thrive, and other severe conditions leading to an early death by 2-5 years of age without supportive care. Here, we studied both these mice, which serve as a model for the parents and close relatives of these children who are likely to suffer long-term disabilities due to partial deficiency of GM1, including Parkinson's disease (PD). We find that the movement and memory disorders manifested by both types of mice can be resolved with GM1 application. This suggests the potential therapeutic value of GM1 for disorders stemming from GM1 deficiency, including GM3 synthase deficiency and PD. It was noteworthy that the GM1 employed in these studies was synthetic rather than animal brain-derived, reaffirming the therapeutic efficacy of the former.

Topics: Animals; G(M1) Ganglioside; Gangliosides; Mice; Parkinson Disease; Sialyltransferases

Following our initial reports on subnormal levels of GM1 in the substantia nigra and occipital cortex of Parkinson's disease (PD) patients, we have examined additional tissues from such patients and found these are also deficient in the ganglioside. These include innervated tissues intimately involved in PD pathology such as colon, heart and others, somewhat less intimately involved, such as skin and fibroblasts. Finally, we have analyzed GM1 in peripheral blood mononuclear cells, a type of tissue apparently with no direct innervation, and found those too to be deficient in GM1. Those patients were all afflicted with the sporadic form of PD (sPD), and we therefore conclude that systemic deficiency of GM1 is a characteristic of this major type of PD. Age is one factor in GM1 decline but is not sufficient; additional GM1 suppressive factors are involved in producing sPD. We discuss these and why GM1 replacement offers promise as a disease-altering therapy.

Topics: G(M1) Ganglioside; Gangliosides; Humans; Leukocytes, Mononuclear; Parkinson Disease

Among the pathological events associated with the dopaminergic neurodegeneration characteristic of Parkinson's disease (PD) are the accumulation of toxic forms of α-synuclein and microglial activation associated with neuroinflammation. Although numerous other processes may participate in the pathogenesis of PD, the two factors mentioned above may play critical roles in the initiation and progression of dopamine neuron degeneration in PD. In this study, we employed a slowly progressing model of PD using adeno-associated virus-mediated expression of human A53T α-synuclein into the substantia nigra on one side of the brain and examined the microglial response in the striatum on the injected side compared to the non-injected (control) side. We further examined the extent to which administration of the neuroprotective ganglioside GM1 influenced α-synuclein-induced glial responses. Changes in a number of microglial morphological measures (i.e., process length, number of endpoints, fractal dimension, lacunarity, density, and cell perimeter) were indicative of the presence of activated microglial and an inflammatory response on the injected side of the brain, compared to the control side. In GM1-treated animals, no significant differences in microglial morphology were observed between the injected and control striata. Follow-up studies showed that mRNA expression for several inflammation-related genes was increased on the A53T α-synuclein injected side vs. the non-injected side in saline-treated animals and that such changes were not observed in GM1-treated animals. These data show that inhibition of microglial activation and potentially damaging neuroinflammation by GM1 ganglioside administration may be among the many factors that contribute to the neuroprotective effects of GM1 in this model and possibly in human PD.

Topics: alpha-Synuclein; Animals; Disease Models, Animal; Dopamine; G(M1) Ganglioside; Inflammation; Microglia; Parkinson Disease; Rats; Substantia Nigra

The fact that Parkinson's disease (PD) pathologies are well advanced in most PD patients by the time of clinical elucidation attests to the importance of early diagnosis. Our attempt to achieve this has capitalized on our previous finding that GM1 ganglioside is expressed at subnormal levels in virtually all tissues of sporadic PD (sPD) patients including blood cells. GM1 is present in most vertebrate cells, is especially abundant in neurons where it was shown essential for their effective functioning and long term viability. We have utilized peripheral blood mononuclear cells (PBMCs) which, despite their low GM1, we found to be significantly lower in sPD patients compared to age-matched healthy controls. To quantify GM1 (and GD1a) we used high performance thin-layer chromatography combined with cholera toxin B linked to horseradish peroxidase, followed by densitometric quantification. GM1 was also deficient in PBMCs from PD patients with mutations in the glucocerebrosidase gene (PD-GBA), apparently even lower than in sPD. Reasons are given why we believe these results obtained with patients manifesting fully developed PD will apply as well to PD patients in preclinical stages-a topic for future study. We also suggest that these findings point to a potential disease altering therapy for PD once the early diagnosis is established.

Topics: Aged; Biomarkers; Blood Chemical Analysis; Case-Control Studies; Early Diagnosis; Female; G(M1) Ganglioside; Gangliosides; Glucosylceramidase; Humans; Leukocytes, Mononuclear; Male; Middle Aged; Mutation; Parkinson Disease; ROC Curve

Parkinson's disease (PD) is characterized by Lewy bodies (composed predominantly of alpha-synuclein [aSyn]) and loss of pigmented midbrain dopaminergic neurons comprising the nigrostriatal pathway. Most PD patients show significant deficiency of gangliosides, including GM1, in the brain, and GM1 ganglioside appears to keep dopaminergic neurons functioning properly. Thus, supplementation of GM1 could potentially provide some rescuing effects. In this study, we demonstrate that intranasal infusion of GD3 and GM1 gangliosides reduces intracellular aSyn levels. GM1 also significantly enhances expression of tyrosine hydroxylase (TH) in the substantia nigra pars compacta of the A53T aSyn overexpressing mouse, following restored nuclear expression of nuclear receptor related 1 (Nurr1, also known as NR4A2), an essential transcription factor for differentiation, maturation, and maintenance of midbrain dopaminergic neurons. GM1 induces epigenetic activation of the TH gene, including augmentation of acetylated histones and recruitment of Nurr1 to the TH promoter region. Our data indicate that intranasal administration of gangliosides could reduce neurotoxic proteins and restore functional neurons via modulating chromatin status by nuclear gangliosides.

Topics: Administration, Intranasal; alpha-Synuclein; Animals; Cell Line; Disease Models, Animal; Down-Regulation; Epigenesis, Genetic; G(M1) Ganglioside; Gangliosides; Gene Expression Regulation; Humans; Male; Mice; Parkinson Disease; Substantia Nigra; Tyrosine 3-Monooxygenase

Parkinson's disease (PD) is a major neurodegenerative disorder characterized by a variety of non-motor symptoms in addition to the well-recognized motor dysfunctions that have commanded primary interest. We previously described a new PD mouse model based on heterozygous disruption of the B4galnt1 gene leading to partial deficiency of the GM1 family of gangliosides that manifested several nigrostriatal neuropathological features of PD as well as movement impairment. We now show this mouse also suffers three non-motor symptoms characteristic of PD involving the gastrointestinal, sympathetic cardiac, and cerebral cognitive systems. Treatment of these animals with a synthetic form of GM1 ganglioside, produced by transfected E. coli, proved ameliorative of these symptoms as well as the motor defect. These findings further suggest subnormal GM1 to be a systemic defect constituting a major risk factor in sporadic PD and indicate the B4galnt1(+/-) (HT) mouse to be a true neuropathological model that recapitulates both motor and non-motor lesions of this condition.

Topics: Animals; Disease Models, Animal; Female; G(M1) Ganglioside; Gastrointestinal Diseases; Male; Memory Disorders; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Motor Skills Disorders; N-Acetylgalactosaminyltransferases; Parkinson Disease

While GM1 may interact with α-synuclein in vitro to inhibit aggregation, the ability of GM1 to protect against α-synuclein toxicity in vivo has not been investigated. We used targeted adeno-associated viral vector (AAV) overexpression of human mutant α-synuclein (A53T) in the rat substantia nigra (SN) to produce degeneration of SN dopamine neurons, loss of striatal dopamine levels, and behavioral impairment. Some animals received daily GM1 ganglioside administration for 6 weeks, beginning 24 hours after AAV-A53T administration or delayed start GM1 administration for 5 weeks beginning 3 weeks after AAV-A53T administration. Both types of GM1 administration protected against loss of SN dopamine neurons and striatal dopamine levels, reduced α-synuclein aggregation, and delayed start administration of GM1 reversed early appearing behavioral deficits. These results extend prior positive results in MPTP models, are consistent with the results of a small clinical study of GM1 in PD patients that showed slowing of symptom progression with chronic use, and argue for the continued refinement and development of GM1 as a potential disease modifying therapy for PD.

Topics: alpha-Synuclein; Animals; Behavior, Animal; Corpus Striatum; Dependovirus; Disease Models, Animal; Dopamine; Dopaminergic Neurons; G(M1) Ganglioside; Gene Expression Regulation; Genetic Vectors; Humans; Neuroprotective Agents; Parkinson Disease; Rats; Substantia Nigra

To observe the effects of GM1 on apomorphine (APO)-induced rotational behavior and the expression of inflammatory factors in 6-hydroxydopamine-induced Parkinson's disease (PD) rat models.. Mature and healthy Wistar rats of either sex with body weight of 150-200 g were randomly divided into control group, PD+APO group and PD+APO+GM1 group (10 mg/kg of GM1, intraperitoneally, once a day, for 14 days; each group with 15 rats). PD rat models were prepared by injecting 6-hydroxydopamine into rat's right striatum, and then rotational behavior was induced by intraperitoneal injection of APO 7 days after operation. Rat rotational behavior was observed, and mRNA and protein levels of interleukin-1β (IL-1β) and interleukin-1Ra (IL-1Ra) were determined, respectively, by RT-PCR and Western blot.. Compared with PD+APO group, the rotational behavior was significantly relieved in PD+APO+GM1 group (p < 0.05). Compared with control group, mRNA and protein expressions of IL-1β in the striatum significantly increased in PD+APO group (p < 0.05). However, mRNA and protein expressions of IL-1β significantly decreased in PD+APO+GM1 group compared with PD+APO group (p < 0.05), but mRNA and protein expressions of IL-1β were also higher in PD+APO+GM1 group than in control group (p < 0.05). mRNA and protein expressions of IL-1Ra in the striatum were significantly higher in PD+APO+GM1 group than in PD+APO group (p < 0.05).. GM1 can inhibit inflammatory reaction through decreasing mRNA and protein expressions of IL-1β and increasing mRNA and protein expressions of IL-1Ra with the therapeutic effects on PD.

Topics: Adrenergic Agents; Animals; Antiparkinson Agents; Apomorphine; Corpus Striatum; Disease Models, Animal; Dopamine Agonists; Female; G(M1) Ganglioside; Gene Expression Regulation; Interleukin 1 Receptor Antagonist Protein; Interleukin-1beta; Male; Oxidopamine; Parkinson Disease; Rats; Rats, Wistar; RNA, Messenger; Stereotyped Behavior

The validity of α-synuclein (α-Syn) as a biomarker for Parkinson's disease (PD) is still under investigation. Conventional methods for capture and quantitation of α-Syn protein in human samples are primarily based on anti-α-Syn antibodies. Specific and competent antibodies were raised against α-Syn. However, capture by anti-α-Syn antibodies may be limited to specific epitope recognition, attributed to protein structure or post-translational modifications. Hence, antibody-based methods for α-Syn capture raise a concern regarding their efficacy to detect the intracellular, unfolded α-Syn pool. An alternative is α-Syn capture by membrane lipids, i.e., to utilize the biochemical property of α-Syn to specifically bind membrane lipids and acquire a characteristic structure following binding. We determined α-Syn levels in human samples using immobilized lipids for α-Syn capture. The lipids used for α-Syn capture consist of phosphatidyl inositol (PI), phosphatidyl serine (PS), and phosphatidyl ethanolamine (PE). Addition of mono-sialoganglioside, GM1 ganglioside, to the immobilized lipids significantly improved α-Syn detection. Following capture, the lipid-bound α-Syn was detected using an anti-α-Syn antibody. Total α-Syn levels in whole blood cells (WBC), cerebrospinal fluid (CSF), and saliva were determined by the lipid-ELISA method.

Topics: Adult; alpha-Synuclein; Antibodies; Blood Cells; Enzyme-Linked Immunosorbent Assay; Female; G(M1) Ganglioside; Healthy Volunteers; Humans; Male; Middle Aged; Parkinson Disease; Phosphatidylethanolamines; Phosphatidylinositols; Phosphatidylserines; Phospholipids; Protein Binding; Protein Conformation; Protein Folding; Saliva

Exosomes are small vesicles released from cells into extracellular space. We have isolated exosomes from neuroblastoma cells and investigated their influence on the aggregation of α-synuclein, a protein associated with Parkinson disease pathology. Using cryo-transmission electron microscopy of exosomes, we found spherical unilamellar vesicles with a significant protein content, and Western blot analysis revealed that they contain, as expected, the proteins Flotillin-1 and Alix. Using thioflavin T fluorescence to monitor aggregation kinetics, we found that exosomes catalyze the process in a similar manner as a low concentration of preformed α-synuclein fibrils. The exosomes reduce the lag time indicating that they provide catalytic environments for nucleation. The catalytic effects of exosomes derived from naive cells and cells that overexpress α-synuclein do not differ. Vesicles prepared from extracted exosome lipids accelerate aggregation, suggesting that the lipids in exosomes are sufficient for the catalytic effect to arise. Using mass spectrometry, we found several phospholipid classes in the exosomes, including phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, and the gangliosides GM2 and GM3. Within each class, several species with different acyl chains were identified. We then prepared vesicles from corresponding pure lipids or defined mixtures, most of which were found to retard α-synuclein aggregation. As a striking exception, vesicles containing ganglioside lipids GM1 or GM3 accelerate the process. Understanding how α-synuclein interacts with biological membranes to promote neurological disease might lead to the identification of novel therapeutic targets.

Topics: alpha-Synuclein; Exosomes; G(M1) Ganglioside; G(M2) Ganglioside; G(M3) Ganglioside; Humans; Parkinson Disease; Phospholipids; Unilamellar Liposomes

GDNF is indispensible for adult catecholaminergic neuron survival, and failure of GDNF signaling has been linked to loss of dopaminergic neurons in Parkinson's disease (PD). This study demonstrates attenuated GDNF signaling in neurons deficient in ganglio-series gangliosides, and restoration of such signaling with LIGA20, a membrane permeable analog of GM1. GM1 is shown to associate in situ with GFRα1 and RET, the protein components of the GDNF receptor, this being necessary for assembly of the tripartite receptor complex. Mice wholly or partially deficient in GM1 due to disruption of the B4galnt1 gene developed PD symptoms based on behavioral and neuropathological criteria which were largely ameliorated by gene therapy with AAV2-GDNF and also with LIGA20 treatment. The nigral neurons of PD subjects that were severely deficient in GM1 showed subnormal levels of tyrosine phosphorylated RET. Also in PD brain, GM1 levels in the occipital cortex, a region of limited PD pathology, were significantly below age-matched controls, suggesting the possibility of systemic GM1 deficiency as a risk factor in PD. This would accord with our finding that mice with partial GM1 deficiency represent a faithful recapitulation of the human disease. Together with the previously demonstrated age-related decline of GM1 in human brain, this points to gradual development of subthreshold levels of GM1 in the brain of PD subjects below that required for effective GDNF signaling. This hypothesis offers a dramatically different explanation for the etiology of sporadic PD as a manifestation of acquired resistance to GDNF.

Topics: Animals; Cell Line; Disease Models, Animal; G(M1) Ganglioside; Gangliosides; Gene Knockdown Techniques; Glial Cell Line-Derived Neurotrophic Factor; Humans; Immunoblotting; Immunohistochemistry; Mice; Parkinson Disease; Signal Transduction; Sphingosine

Preclinical and clinical studies have previously shown that systemic administration of GM1 ganglioside has neuroprotective and neurorestorative properties in Parkinson's disease (PD) models and in PD patients. However, the clinical development of GM1 for PD has been hampered by its animal origin (GM1 used in previous studies was extracted from bovine brains), limited bioavailability, and limited blood brain barrier penetrance following systemic administration.. To assess an alternative therapeutic approach to systemic administration of brain-derived GM1 to enhance GM1 levels in the brain via enzymatic conversion of polysialogangliosides into GM1 and to assess the neuroprotective potential of this approach.. We used sialidase from Vibrio cholerae (VCS) to convert GD1a, GD1b and GT1b gangliosides to GM1. VCS was infused by osmotic minipump into the dorsal third ventricle in mice over a 4-week period. After the first week of infusion, animals received MPTP injections (20 mg/kg, s.c., twice daily, 4 hours apart, for 5 consecutive days) and were euthanized 2 weeks after the last injection.. VCS infusion resulted in the expected change in ganglioside expression with a significant increase in GM1 levels. VCS-treated animals showed significant sparing of striatal dopamine (DA) levels and substantia nigra DA neurons following MPTP administration, with the extent of sparing of DA neurons similar to that achieved with systemic GM1 administration.. The results suggest that enzymatic conversion of polysialogangliosides to GM1 may be a viable treatment strategy for increasing GM1 levels in the brain and exerting a neuroprotective effect on the damaged nigrostriatal DA system.

Topics: Animals; Disease Models, Animal; Dopamine; G(M1) Ganglioside; Gene Expression Regulation; Infusions, Intraventricular; Male; Mice; Mice, Inbred C57BL; Neuraminidase; Neurons; Neuroprotective Agents; Parkinson Disease; Pars Compacta; Vibrio cholerae

Several studies have successfully employed GM1 ganglioside to treat animal models of Parkinson's disease (PD), suggesting involvement of this ganglioside in PD etiology. We recently demonstrated that genetically engineered mice (B4galnt1(-/-) ) devoid of GM1 acquire characteristic symptoms of this disorder, including motor impairment, depletion of striatal dopamine, selective loss of tyrosine hydroxylase-expressing neurons, and aggregation of α-synuclein. The present study demonstrates similar symptoms in heterozygous mice (HTs) that express only partial GM1 deficiency. Symptoms were alleviated by administration of L-dopa or LIGA-20, a membrane-permeable analog of GM1 that penetrates the blood-brain barrier and accesses intracellular compartments. Immunohistochemical analysis of paraffin sections from PD patients revealed significant GM1 deficiency in nigral dopaminergic neurons compared with age-matched controls. This was comparable to the GM1 deficiency of HT mice and suggests that GM1 deficiency may be a contributing factor to idiopathic PD. We propose that HT mice with partial GM1 deficiency constitute an especially useful model for PD, reflecting the actual pathophysiology of this disorder. The results point to membrane-permeable analogs of GM1 as holding promise as a form of GM1 replacement therapy.

Topics: 3,4-Dihydroxyphenylacetic Acid; Aged; Aged, 80 and over; Aging; Animals; Antiparkinson Agents; Blotting, Western; Cell Count; Dopamine; Dopaminergic Neurons; Female; G(M1) Ganglioside; Gangliosides; Humans; Immunohistochemistry; Levodopa; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; N-Acetylgalactosaminyltransferases; Parkinson Disease; Polypeptide N-acetylgalactosaminyltransferase; Synucleins; Tyrosine 3-Monooxygenase

Alpha-synuclein (alpha-syn) is an amyloidogenic protein that plays a key role in the pathogenesis of Parkinson's disease (PD). The ability of alpha-syn oligomers to form ionic channels is postulated as a channelopathy mechanism in human brain. Here we identified a ganglioside-binding domain in alpha-syn (fragment 34-50), which includes the mutation site 46 linked to a familial form of PD (E46K). We show that this fragment is structurally related to the common glycosphingolipid-binding domain (GBD) shared by various microbial and amyloid proteins, including Alzheimer's beta-amyloid peptide. alpha-Syn GBD interacts with several glycosphingolipids but has a marked preference for GM3, a minor brain ganglioside whose expression increases with aging. The alpha-syn mutant E46K has a stronger affinity for GM3 than the wild-type protein, and the interaction is inhibited by 3'-sialyllactose (the glycone part of GM3). Alanine substitutions of Lys34 and Tyr39 in synthetic GBD peptides resulted in limited interaction with GM3, demonstrating the critical role of these residues in GM3 recognition. When incubated with reconstituted phosphatidylcholine bilayers, the E46K protein formed channels that are five times less conductive than those formed by wild-type alpha-syn, exhibit a higher selectivity for cations, and present an asymmetrical response to voltage and nonstop single-channel activity. This E46K-associated channelopathy was no longer observed when GM3 was present in phosphatidylcholine bilayers. This corrective effect was highly specific for GM3, since it was not obtained with the major brain ganglioside GM1 but was still detected in bilayer membranes containing both GM3 and GM1. Moreover, synthetic GBD peptides prevented the interaction of alpha-syn proteins with GM3, thus abolishing the regulatory effects of GM3 on alpha-syn-mediated channel formation. Overall, these data show that GM3 can specifically regulate alpha-syn-induced channel formation and raise the intriguing possibility that this minor brain ganglioside could play a key protective role in the pathogenesis of PD.

Topics: alpha-Synuclein; Amino Acid Sequence; Amino Acid Substitution; G(M1) Ganglioside; G(M3) Ganglioside; Humans; Hydrogen Bonding; Ion Channels; Micelles; Models, Molecular; Molecular Sequence Data; Mutant Proteins; Parkinson Disease; Protein Structure, Secondary; Protein Structure, Tertiary

ALpha-synuclein (alpha-syn) has been known to be a key player of the pathogenesis of Parkinson's disease and has recently been detected in extracellular biological fluids and shown to be rapidly secreted from cells. The penetration of alpha-syn into cells has also been observed. In this study, we observed that dl-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol, a glucosyltransferase inhibitor, and proteinase K inhibited the internalization of extracellular monomeric alpha-syn into BV-2 cells, and the addition of monosialoganglioside GM1 ameliorated the inhibition of alpha-syn internalization in dl-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol-treated BV-2 cells. Furthermore, inhibition of clathrin-, caveolae-, and dynamin-dependent endocytosis did not prevent the internalization of alpha-syn, but disruption of lipid raft inhibited it. Inhibition of macropinocytosis and disruption of actin and microtubule structures also did not inhibit the internalization of alpha-syn. In addition, we further confirmed these observations by co-culture system of BV-2 cells and alpha-syn-over-expressing SH-SY5Y cells. These findings suggest that extracellular alpha-syn is internalized into microglia via GM1 as well as hitherto-unknown protein receptors in clathrin-, caveolae-, and dynamin-independent, but lipid raft-dependent manner. Elucidation of the mechanism involved in internalization of alpha-syn should be greatly helpful in the development of new treatments of alpha-syn-related neurodegenerative diseases.

Topics: alpha-Synuclein; Animals; Caveolins; Cell Line; Cell Line, Tumor; Clathrin; Coculture Techniques; Dynamins; Encephalitis; Endocytosis; Endopeptidase K; Enzyme Inhibitors; Extracellular Space; G(M1) Ganglioside; Glucosyltransferases; Humans; Membrane Microdomains; Mice; Microglia; Neurodegenerative Diseases; Parkinson Disease; Protein Transport

We report the case of a patient with Parkinson's disease who developed rapidly progressive weakness of the four limbs due to an acute motor axonal neuropathy (AMAN). This occurred days after a neuroleptic malignant syndrome (NMS). Serologic evidence of a preceding Campylobacter jejuni infection was detected and treatment with intravenous immunoglobulins proved effective. This case suggests that the rarely described neuropathies occurring with NMS may have a postinfectious immune basis and respond to immunomodulatory therapy.

Topics: Antibodies, Bacterial; Antiparkinson Agents; Campylobacter Infections; Campylobacter jejuni; Electromyography; Fever; G(M1) Ganglioside; Guillain-Barre Syndrome; Humans; Immunoglobulin G; Immunoglobulin M; Immunoglobulins, Intravenous; Lipopolysaccharides; Male; Middle Aged; Molecular Mimicry; Neural Conduction; Neuroleptic Malignant Syndrome; Parkinson Disease; Quadriplegia; Unconsciousness

Topics: Acute Disease; Animals; Antiparkinson Agents; Brain Ischemia; Drugs, Investigational; G(M1) Ganglioside; Humans; Neuroprotective Agents; Parkinson Disease; Stroke

GM1 ganglioside has been shown to stimulate recovery of the damaged dopamine system under a number of different circumstances. In addition to rescue of damaged dopamine neurons, the present study assessed the ability of GM1 to enhance the synthesis of dopamine in remaining nigrostriatal neurons following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) exposure. There was a significantly greater accumulation of L-dopa 30 min after aromatic amino acid decarboxylase inhibition with NSD-1015 (100 mg/kg) and an increase in the ratio of L-dopa to dopamine in MPTP+GM1-treated mice than in mice that received only MPTP. This effect of GM1 on dopamine synthesis was dependent upon the degree of initial damage to the nigrostriatal dopamine system. That is, the GM1 effect on dopamine synthesis could not be demonstrated in mice with greater than 95% striatal dopamine loss and 75% substantia nigra dopamine neuron loss. These results suggest that in addition to previously reported effects of GM1 on rescue and repair of dopaminergic neurons, GM1 may also have the ability to enhance dopamine synthesis in residual dopaminergic neurons. Direct effects on dopamine neurochemistry may contribute to functional improvement seen after GM1 treatment in various models of parkinsonism.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Corpus Striatum; Disease Models, Animal; Dopamine; G(M1) Ganglioside; Levodopa; Mice; Mice, Inbred C57BL; Neurons; Parkinson Disease; Substantia Nigra

Topics: Alzheimer Disease; Bone Regeneration; Brain Tissue Transplantation; Coronary Circulation; G(M1) Ganglioside; Humans; Hyaluronic Acid; Models, Cardiovascular; Parkinson Disease; Publishing; Research; Sweden

The semisynthetic glycosphingolipid derivative II3Neu5-AcGgOse4-2-d-erythro-1,3-dihydroxy-2-chloro-acetamid e-4-trans- octadacene (LIGA20) attenuated injury induced by the excitotoxic L-dopa metabolite 2,4,5-trihydroxyphenylalanine (TOPA) in cultures of rat cerebellar granule cells when presented simultaneously with TOPA (EC50; 9 microM LIGA20). The natural glycosphingolipid ganglioside GM1 up to 200 microM was not neuroprotective as cotreatment, although pretreatment of cells for 2 h was efficacious. This greater potency and speed of LIGA20 action extended to limiting TOPA-induced death of cultured mesencephalic dopaminergic neurons. These data suggest that LIGA20 may have therapeutic potential for the treatment of disorders associated with excitotoxic processes.

Topics: Animals; Cells, Cultured; Cerebellum; Dihydroxyphenylalanine; G(M1) Ganglioside; Glycosphingolipids; Neurons; Parkinson Disease; Rats; Sphingosine

The neurotoxic properties of 2,4,5-trihydroxyphenylalanine (TOPA; the 6-hydroxylated derivative of dopa) was investigated in cultures of central neurons. Application of solutions of TOPA to cerebellar granule cells resulted in a concentration- and time-dependent neuronal death, with prolonged (24 hr) exposure producing a clear left-handed shift in the dose-response relationship from the one observed with a 60-min exposure (LD50: 4 and 29 microM, respectively). This toxicity was largely blocked by the non-N-methyl-D-aspartate antagonist 6-cyano-7-nitroquinoxaline-2,3-dione. Solutions of TOPA were also toxic to mesencephalic neurons after acute or chronic exposure, displaying the same leftward shift in LD50. This latter preparation contained a minor population of dopaminergic, tyrosine hydroxylase immunopositive cells which were likewise sensitive to the excitotoxic effects of TOPA. Neurotoxic activity of TOPA appeared to depend upon its oxidation in solution, as judged using chemical analysis and reducing agents. The monosialoganglioside GM1 was effective in protecting against neurodegeneration induced by brief or prolonged exposure to solutions of TOPA. These results suggest that an abnormal production or accumulation of TOPA or its oxidation product(s) might be involved in excitotoxicity directed to areas of the brain with dopaminergic innervation, and in other brain areas in Parkinson's disease patients on long-term dopa therapy. The selective action of gangliosides in disrupting the pathological consequences of glutamate receptor activation proposes their use as chemoprophylactic agents for preventing or arresting the neuronal losses accompanying such situations.

Topics: 6-Cyano-7-nitroquinoxaline-2,3-dione; Animals; Cells, Cultured; Cerebellum; Dihydroxyphenylalanine; G(M1) Ganglioside; Mesencephalon; MPTP Poisoning; Oxidation-Reduction; Parkinson Disease; Quinoxalines; Rats; Rats, Sprague-Dawley

We investigated the effect of GM1 gangliosides on a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model of Parkinson disease. Five groups of mice (saline, GM1 (30 mg/kg), MPTP, MPTP + GM1 (15 mg/kg), MPTP + GM1 (30 mg/kg] were compared. GM1 was given daily via intraperitoneal injection before and during 13 daily doses of MPTP (30 mg/kg). Mice were tested for locomotion (1) within 2 h of an MPTP dose (to measure reduced motor activity), and (2) within 24 h of an MPTP dose (after animals had recovered and exhibited hyperactivity). We found that mice given GM1 gangliosides exhibited significantly less MPTP-induced behavior. This effect was most evident with the 15 mg/kg GM1 dose. GM1 also appeared to attenuate MPTP-induced neurochemical changes. GM1 effects indicating enhancement of DA turnover and preservation of DA, DOPAC and HVA concentrations in the striatum were found after the 8th MPTP dose. These latter neurochemical changes, however, were transient and not present after the 13th MPTP dose. Our data would suggest that gangliosides may reduce acute MPTP-induced neurotoxicity in mice either through an increase in DA neuron survival and/or the augmentation of striatal DA activity.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; 3,4-Dihydroxyphenylacetic Acid; Animals; Behavior, Animal; Corpus Striatum; Dopamine; G(M1) Ganglioside; Homovanillic Acid; Male; Mice; Mice, Inbred Strains; Movement; Parkinson Disease; Parkinson Disease, Secondary