1
|
Stipa G, Ancidoni A, Vanacore N, Bellomo G. Raw Water and ALS: A Unifying Hypothesis for the Environmental Agents Involved in ALS. Ann Neurosci 2023; 30:124-132. [PMID: 37706096 PMCID: PMC10496797 DOI: 10.1177/09727531221120358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/22/2022] [Indexed: 09/15/2023] Open
Abstract
Different studies identified the presence of several altered genes in familial and sporadic amyotrophic lateral sclerosis (ALS) forms. The experimental data, together with the epidemiological data, would seem to suggest the existence of molecular mechanisms (e.g., axonal transport) related to these genes, together with a susceptibility of the same genes to certain environmental factors that would therefore suggest an impact of the environment on the etiopathogenesis of ALS. In our review, we considered the most relevant environmental clusters around the world, collecting different hypotheses and underlining common environmental factors among the different clusters. Moreover, further epidemiological data identified a higher risk of ALS in professional athletes and, in particular, in soccer and football players. Despite this increased risk of ALS highlighted by the epidemiological evidence in aforementioned sports, the mechanisms remain unclear. At last, the use of raw water has been associated with ALS risk. The aim of the present review is to characterize a possible relationship between these clusters, to be explored in the context of the interaction between genetic and environmental factors on the etiopathogenesis of ALS.
Collapse
Affiliation(s)
- Giuseppe Stipa
- Clinical Neurophysiology Division, Neuroscience Department, S. Maria University Hospital, Terni, Italy
| | - Antonio Ancidoni
- National Center for Disease Prevention and Health Promotion, National Institute of Health (ISS), Roma, Italy
| | - Nicola Vanacore
- National Center for Disease Prevention and Health Promotion, National Institute of Health (ISS), Roma, Italy
| | - Guido Bellomo
- National Center for Disease Prevention and Health Promotion, National Institute of Health (ISS), Roma, Italy
| |
Collapse
|
2
|
Davis DA, Garamszegi SP, Banack SA, Dooley PD, Coyne TM, McLean DW, Rotstein DS, Mash DC, Cox PA. BMAA, Methylmercury, and Mechanisms of Neurodegeneration in Dolphins: A Natural Model of Toxin Exposure. Toxins (Basel) 2021; 13:toxins13100697. [PMID: 34678990 PMCID: PMC8540894 DOI: 10.3390/toxins13100697] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/19/2021] [Accepted: 09/22/2021] [Indexed: 01/15/2023] Open
Abstract
Dolphins are well-regarded sentinels for toxin exposure and can bioaccumulate a cyanotoxin called β-N-methylamino-l-alanine (BMAA) that has been linked to human neurodegenerative disease. The same dolphins also possessed hallmarks of Alzheimer’s disease (AD), suggesting a possible association between toxin exposure and neuropathology. However, the mechanisms of neurodegeneration in dolphins and the impact cyanotoxins have on these processes are unknown. Here, we evaluate BMAA exposure by investigating transcription signatures using PCR for dolphin genes homologous to those implicated in AD and related dementias: APP, PSEN1, PSEN2, MAPT, GRN, TARDBP, and C9orf72. Immunohistochemistry and Sevier Münger silver staining were used to validate neuropathology. Methylmercury (MeHg), a synergistic neurotoxicant with BMAA, was also measured using PT-GC-AFS. We report that dolphins have up to a three-fold increase in gene transcription related to Aβ+ plaques, neurofibrillary tangles, neuritic plaques, and TDP-43+ intracytoplasmic inclusions. The upregulation of gene transcription in our dolphin cohort paralleled increasing BMAA concentration. In addition, dolphins with BMAA exposures equivalent to those reported in AD patients displayed up to a 14-fold increase in AD-type neuropathology. MeHg was detected (0.16–0.41 μg/g) and toxicity associated with exposure was also observed in the brain. These results demonstrate that dolphins develop neuropathology associated with AD and exposure to BMAA and MeHg may augment these processes.
Collapse
Affiliation(s)
- David A. Davis
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.P.G.); (P.D.D.); (D.W.M.); (D.C.M.)
- Correspondence:
| | - Susanna P. Garamszegi
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.P.G.); (P.D.D.); (D.W.M.); (D.C.M.)
| | - Sandra Anne Banack
- Brain Chemistry Labs, Institute for Ethnomedicine, Jackson, WY 83001, USA; (S.A.B.); (P.A.C.)
| | - Patrick D. Dooley
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.P.G.); (P.D.D.); (D.W.M.); (D.C.M.)
| | - Thomas M. Coyne
- Office of the District 21 Medical Examiner, Fort Myers, FL 33907, USA;
| | - Dylan W. McLean
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.P.G.); (P.D.D.); (D.W.M.); (D.C.M.)
| | | | - Deborah C. Mash
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.P.G.); (P.D.D.); (D.W.M.); (D.C.M.)
- Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Dr. Kiran C. Patel College of Allopathic Medicine, Nova Southeastern University, Davie, FL 33328, USA
| | - Paul Alan Cox
- Brain Chemistry Labs, Institute for Ethnomedicine, Jackson, WY 83001, USA; (S.A.B.); (P.A.C.)
| |
Collapse
|
3
|
Quinn AW, Phillips CR, Violi JP, Steele JR, Johnson MS, Westerhausen MT, Rodgers KJ. β-Methylamino-L-alanine-induced protein aggregation in vitro and protection by L-serine. Amino Acids 2021; 53:1351-1359. [PMID: 34283312 DOI: 10.1007/s00726-021-03049-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 07/12/2021] [Indexed: 10/20/2022]
Abstract
The cyanobacterial non-protein amino acid α-amino-β-methylaminopropionic acid, more commonly known as BMAA, was first discovered in the seeds of the ancient gymnosperm Cycad circinalis (now Cycas micronesica Hill). BMAA was linked to the high incidence of neurological disorders on the island of Guam first reported in the 1950s. BMAA still attracts interest as a possible causative factor in amyotrophic lateral sclerosis (ALS) following the identification of ALS disease clusters associated with living in proximity to lakes with regular cyanobacterial blooms. Since its discovery, BMAA toxicity has been the subject of many in vivo and in vitro studies. A number of mechanisms of toxicity have been proposed including an agonist effect at glutamate receptors, competition with cysteine for transport system xc_ and other mechanisms capable of generating cellular oxidative stress. In addition, a wide range of studies have reported effects related to disturbances in proteostasis including endoplasmic reticulum stress and activation of the unfolded protein response. In the present studies we examine the effects of BMAA on the ubiquitin-proteasome system (UPS) and on chaperone-mediated autophagy (CMA) by measuring levels of ubiquitinated proteins and lamp2a protein levels in a differentiated neuronal cell line exposed to BMAA. The BMAA induced increases in oxidised proteins and the increase in CMA activity reported could be prevented by co-administration of L-serine but not by the two antioxidants examined. These data provide further evidence of a protective role for L-serine against the deleterious effects of BMAA.
Collapse
Affiliation(s)
- Adam W Quinn
- Neurotoxin Research Group, School of Life Sciences, University of Technology Syd, ney, Faculty of Science, Building 4, Level 7, room 329. Thomas Street, Sydney, NSW, 2007, Australia
| | - Connor R Phillips
- Neurotoxin Research Group, School of Life Sciences, University of Technology Syd, ney, Faculty of Science, Building 4, Level 7, room 329. Thomas Street, Sydney, NSW, 2007, Australia
| | - Jake P Violi
- Neurotoxin Research Group, School of Life Sciences, University of Technology Syd, ney, Faculty of Science, Building 4, Level 7, room 329. Thomas Street, Sydney, NSW, 2007, Australia
| | - Joel R Steele
- Neurotoxin Research Group, School of Life Sciences, University of Technology Syd, ney, Faculty of Science, Building 4, Level 7, room 329. Thomas Street, Sydney, NSW, 2007, Australia
| | - Michael S Johnson
- Neurotoxin Research Group, School of Life Sciences, University of Technology Syd, ney, Faculty of Science, Building 4, Level 7, room 329. Thomas Street, Sydney, NSW, 2007, Australia
| | - Mika T Westerhausen
- Neurotoxin Research Group, School of Life Sciences, University of Technology Syd, ney, Faculty of Science, Building 4, Level 7, room 329. Thomas Street, Sydney, NSW, 2007, Australia
| | - Kenneth J Rodgers
- Neurotoxin Research Group, School of Life Sciences, University of Technology Syd, ney, Faculty of Science, Building 4, Level 7, room 329. Thomas Street, Sydney, NSW, 2007, Australia.
| |
Collapse
|
4
|
Transfer of the Neurotoxin β- N-methylamino-l-alanine (BMAA) in the Agro-Aqua Cycle. Mar Drugs 2020; 18:md18050244. [PMID: 32384637 PMCID: PMC7281744 DOI: 10.3390/md18050244] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/30/2022] Open
Abstract
The neurotoxic non-protein amino acid β-N-methylamino-l-alanine (BMAA) is connected to the development of neurodegenerative diseases. BMAA has been shown to accumulate in aquatic ecosystems, and filter-feeding molluscs seem particularly susceptible to BMAA accumulation. The blue mussels farmed along the Swedish coastline in the Baltic Sea are, due to their small size, exclusively used to produce feed for chicken and fish in the agro-aqua cycle. We have investigated the possible biotransfer of BMAA from mussels, via mussel-based feed, into chickens. Chickens were divided into two groups, the control and the treatment. BMAA was extracted from the muscle, liver, brain, and eye tissues in both chicken groups; a UPLC-MS/MS method was subsequently used to quantify BMAA. The results indicate detectable concentrations of BMAA in both chicken groups. However, the BMAA concentration in chicken was 5.65 times higher in the treatment group than the control group, with the highest concentration found in muscle tissue extracted from the treatment group chickens. These data suggest that there is a BMAA transfer route within the agro-aqua cycle, so further investigation is recommended before using mussel-based feed in the chicken industry.
Collapse
|
5
|
Occurrence of β-N-methylamino-l-alanine (BMAA) and Isomers in Aquatic Environments and Aquatic Food Sources for Humans. Toxins (Basel) 2018; 10:toxins10020083. [PMID: 29443939 PMCID: PMC5848184 DOI: 10.3390/toxins10020083] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/06/2018] [Accepted: 02/08/2018] [Indexed: 12/13/2022] Open
Abstract
The neurotoxin β-N-methylamino-l-alanine (BMAA), a non-protein amino acid produced by terrestrial and aquatic cyanobacteria and by micro-algae, has been suggested to play a role as an environmental factor in the neurodegenerative disease Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia complex (ALS-PDC). The ubiquitous presence of BMAA in aquatic environments and organisms along the food chain potentially makes it public health concerns. However, the BMAA-associated human health risk remains difficult to rigorously assess due to analytical challenges associated with the detection and quantification of BMAA and its natural isomers, 2,4-diamino butyric acid (DAB), β-amino-N-methyl-alanine (BAMA) and N-(2-aminoethyl) glycine (AEG). This systematic review, reporting the current knowledge on the presence of BMAA and isomers in aquatic environments and human food sources, was based on a selection and a score numbering of the scientific literature according to various qualitative and quantitative criteria concerning the chemical analytical methods used. Results from the best-graded studies show that marine bivalves are to date the matrix containing the higher amount of BMAA, far more than most fish muscles, but with an exception for shark cartilage. This review discusses the available data in terms of their use for human health risk assessment and identifies knowledge gaps requiring further investigations.
Collapse
|
6
|
Main BJ, Rodgers KJ. Assessing the Combined Toxicity of BMAA and Its Isomers 2,4-DAB and AEG In Vitro Using Human Neuroblastoma Cells. Neurotox Res 2017. [PMID: 28634653 DOI: 10.1007/s12640-017-9763-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The non-protein amino acid (NPAA) ß-methylamino-L-alanine (BMAA) is produced by a diverse range of cyanobacteria, diatoms and dinoflagellates, and is present in both aquatic and terrestrial ecosystems globally. Exposure to BMAA has been implicated in the development of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD) and Parkinson's disease (PD). BMAA is often found in nature along with its structural isomers 2,4-diaminobutyric acid (2,4-DAB) and aminoethylglycine (AEG); however, the toxicity of these NPAAs in combination has not been examined. We have previously demonstrated that BMAA induces endoplasmic reticulum (ER) stress and increases caspase and cathepsin activity in human neuroblastoma cells (SH-SY5Y), effects consistent with proteotoxic stress due to disturbances in protein synthesis, folding or turnover. The current study investigates whether 2,4-DAB and AEG share a similar mechanism of toxicity to BMAA, and if simultaneous exposure of cells to BMAA and its isomers results in increased toxicity in vitro. We show that a 48-h treatment with both 500 μM BMAA and 2,4-DAB decreases cell viability in vitro whereas AEG was not cytotoxic under the same conditions. Treatment of SH-SY5Y cells with 2,4-DAB did not increase expression of ER stress markers. Combined treatment of cells with BMAA and 2,4-DAB resulted in increased caspase activity and increased apoptosis above that of BMAA or 2,4-DAB on their own. These results suggest that 2,4-DAB does not share the same mechanism of toxicity as BMAA but the presence of 2,4-DAB increases the toxicity of BMAA to human cells in vitro.
Collapse
Affiliation(s)
- Brendan J Main
- School of Life Sciences, University of Technology Sydney, Broadway, Ultimo, NSW, 2007, Australia
| | - Kenneth J Rodgers
- School of Life Sciences, University of Technology Sydney, Broadway, Ultimo, NSW, 2007, Australia.
| |
Collapse
|
7
|
Caller T, Henegan P, Stommel E. The Potential Role of BMAA in Neurodegeneration. Neurotox Res 2017; 33:222-226. [PMID: 28612294 DOI: 10.1007/s12640-017-9752-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/09/2017] [Accepted: 05/12/2017] [Indexed: 01/09/2023]
Abstract
Neurodegenerative diseases are a major public health issue throughout the world with devastating effects on patients and families. Sporadic forms of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis are generally thought to develop as a consequence of genetic susceptibility and environmental influences. A number of environmental triggers have been identified in association with amyotrophic lateral sclerosis and Parkinson's disease. We discuss the role of β-methylamino-L-alanine in the development of neurodegeneration and the potential importance of this neurotoxin as a risk for neurodegeneration.
Collapse
Affiliation(s)
- Tracie Caller
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, 03756, USA. .,Cheyenne Regional Medical Group, Cheyenne, WY, 82001, USA. .,Institute for Ethnomedicine, PO Box 3464, Jackson, WY, 83001, USA.
| | - Patricia Henegan
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, 03756, USA
| | - Elijah Stommel
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, 03756, USA
| |
Collapse
|
8
|
Cloutier F, Marrero A, O'Connell C, Morin P. MicroRNAs as potential circulating biomarkers for amyotrophic lateral sclerosis. J Mol Neurosci 2014; 56:102-12. [PMID: 25433762 DOI: 10.1007/s12031-014-0471-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 01/04/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a condition primarily characterized by the selective loss of upper and lower motor neurons. Motor neuron loss gives rise to muscle tissue malfunctions, including weakness, spasticity, atrophy, and ultimately paralysis, with death typically due to respiratory failure within 2 to 5 years of symptoms' onset. The mean delay in time from presentation to diagnosis remains at over 1 year. Biomarkers are urgently needed to facilitate ALS diagnosis and prognosis as well as to act as indicators of therapeutic response in clinical trials. MicroRNAs (miRNAs) are small molecules that can influence posttranscriptional gene expression of a variety of transcript targets. Interestingly, miRNAs can be released into the circulation by pathologically affected tissues. This review presents therapeutic and diagnostic challenges associated with ALS, highlights the potential role of miRNAs in ALS, and discusses the diagnostic potential of these molecules in identifying ALS-specific miRNAs or in distinguishing between the various genotypic and phenotypic forms of ALS.
Collapse
Affiliation(s)
- Frank Cloutier
- Institut de l'Atlantique en Neurosciences Atlantic Institute, Vitalité Health Network, Centre Hospitalier Universitaire Dr Georges-L.-Dumont/Dr. Georges-L.-Dumont University Hospital Centre, Moncton, NB, Canada,
| | | | | | | |
Collapse
|
9
|
Andersson M, Karlsson O, Bergström U, Brittebo EB, Brandt I. Maternal transfer of the cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) via milk to suckling offspring. PLoS One 2013; 8:e78133. [PMID: 24194910 PMCID: PMC3806833 DOI: 10.1371/journal.pone.0078133] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 09/17/2013] [Indexed: 12/14/2022] Open
Abstract
The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) has been implicated in the etiology of neurodegenerative disease and proposed to be biomagnified in terrestrial and aquatic food chains. We have previously shown that the neonatal period in rats, which in humans corresponds to the last trimester of pregnancy and the first few years of age, is a particularly sensitive period for exposure to BMAA. The present study aimed to examine the secretion of 14C-labeled L- and D-BMAA into milk in lactating mice and the subsequent transfer of BMAA into the developing brain. The results suggest that secretion into milk is an important elimination pathway of BMAA in lactating mothers and an efficient exposure route predominantly for L-BMAA but also for D-BMAA in suckling mice. Following secretion of [14C]L-BMAA into milk, the levels of [14C]L-BMAA in the brains of the suckling neonatal mice significantly exceeded the levels in the maternal brains. In vitro studies using the mouse mammary epithelial HC11 cell line confirmed a more efficient influx and efflux of L-BMAA than of D-BMAA in cells, suggesting enantiomer-selective transport. Competition experiments with other amino acids and a low sodium dependency of the influx suggests that the amino acid transporters LAT1 and LAT2 are involved in the transport of L-BMAA into milk. Given the persistent neurodevelopmental toxicity following injection of L-BMAA to neonatal rodent pups, the current results highlight the need to determine whether BMAA is enriched mother's and cow's milk.
Collapse
Affiliation(s)
- Marie Andersson
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
| | - Oskar Karlsson
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Ulrika Bergström
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
| | - Eva B. Brittebo
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Ingvar Brandt
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
- * E-mail:
| |
Collapse
|
10
|
Spencer PS, Palmer VS. Interrelationships of undernutrition and neurotoxicity: food for thought and research attention. Neurotoxicology 2012; 33:605-16. [PMID: 22394483 PMCID: PMC3437940 DOI: 10.1016/j.neuro.2012.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 02/13/2012] [Accepted: 02/13/2012] [Indexed: 12/25/2022]
Abstract
The neurotoxic actions of chemical agents on humans and animals are usually studied with little consideration of the subject's nutritional status. States of protein-calorie, vitamin and/or mineral undernutrition are associated with a range of neurodevelopmental, neurological and psychiatric disorders, commonly with involvement of both the central and the peripheral nervous system. Undernutrition can modify risk for certain chemical-induced neurologic diseases, and in some cases undernutrition may be a prerequisite for neurotoxicity to surface. In addition, neurologic disease associated with undernutrition or neurotoxicity may show similarities in clinical and neuropathological expression, especially in the peripheral nervous system. The combined effects of undernutrition and chemical neurotoxicity are most relevant to people with low incomes who experience chronic hunger, parasitism and infectious disease, monotonous diets of plants with neurotoxic potential (notably cassava), environmental pollution from rapid industrial development, chronic alcohol abuse, or prolonged treatment with certain therapeutic drugs. Undernutrition alone or in combination with chemical exposure is also important in high-income societies in the setting of drug and alcohol abuse, old age, food faddism, post-bariatric surgery, and drug treatment for certain medical conditions, including cancer and tuberculosis. The nutritional demands of pregnancy and lactation increase the risk of fetal and infant undernutrition and chemical interactions therewith.
Collapse
Affiliation(s)
- Peter S Spencer
- Global Health Center, Center for Research on Occupational and Environmental Toxicology, and Department of Neurology, School of Medicine, Oregon Health & Science University, Portland, OR 97239, United States.
| | | |
Collapse
|
11
|
Is neurodegenerative disease a long-latency response to early-life genotoxin exposure? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2011; 8:3889-921. [PMID: 22073019 PMCID: PMC3210588 DOI: 10.3390/ijerph8103889] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 09/09/2011] [Accepted: 09/15/2011] [Indexed: 01/03/2023]
Abstract
Western Pacific amyotrophic lateral sclerosis and parkinsonism-dementia complex, a disappearing neurodegenerative disease linked to use of the neurotoxic cycad plant for food and/or medicine, is intensively studied because the neuropathology (tauopathy) is similar to that of Alzheimer's disease. Cycads contain neurotoxic and genotoxic principles, notably cycasin and methylazoxymethanol, the latter sharing chemical relations with nitrosamines, which are derived from nitrates and nitrites in preserved meats and fertilizers, and also used in the rubber and leather industries. This review includes new data that influence understanding of the neurobiological actions of cycad and related genotoxins and the putative mechanisms by which they might trigger neurodegenerative disease.
Collapse
|
12
|
The cyanobacteria derived toxin Beta-N-methylamino-L-alanine and amyotrophic lateral sclerosis. Toxins (Basel) 2010; 2:2837-50. [PMID: 22069578 PMCID: PMC3153186 DOI: 10.3390/toxins2122837] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 12/17/2010] [Accepted: 12/17/2010] [Indexed: 12/14/2022] Open
Abstract
There is mounting evidence to suggest that environmental factors play a major role in the development of neurodegenerative diseases like ALS (Amyotrophic Lateral Sclerosis). The non-protein amino acid beta-N-methylamino-L-alanine (BMAA) was first associated with the high incidence of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia Complex (ALS/PDC) in Guam, and has been implicated as a potential environmental factor in ALS, Alzheimer’s disease, and other neurodegenerative diseases. BMAA has a number of toxic effects on motor neurons including direct agonist action on NMDA and AMPA receptors, induction of oxidative stress, and depletion of glutathione. As a non-protein amino acid, there is also the strong possibility that BMAA could cause intraneuronal protein misfolding, the hallmark of neurodegeneration. While an animal model for BMAA-induced ALS is lacking, there is substantial evidence to support a link between this toxin and ALS. The ramifications of discovering an environmental trigger for ALS are enormous. In this article, we discuss the history, ecology, pharmacology and clinical ramifications of this ubiquitous, cyanobacteria-derived toxin.
Collapse
|
13
|
Tasker RA, Adams-Marriott AL, Shaw CA. New animal models of progressive neurodegeneration: tools for identifying targets in predictive diagnostics and presymptomatic treatment. EPMA J 2010. [PMID: 23199060 PMCID: PMC3405326 DOI: 10.1007/s13167-010-0019-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mental and neurological disorders are increasingly prevalent and constitute a major societal and economic burden worldwide. Many of these diseases and disorders are characterized by progressive deterioration over time, that ultimately results in identifiable symptoms that in turn dictate therapy. Disease-specific symptoms, however, often occur late in the degenerative process. A better understanding of presymptomatic events could allow for the development of new diagnostics and earlier interventions that could slow or stop the disease process. Such studies of progressive neurodegeneration require the use of animal models that are characterized by delayed or slowly developing disease phenotype(s). This brief review describes several examples of such animal models that have recently been developed with relevance to various neurological diseases and disorders, and delineates the potential of such models to aid in predictive diagnosis, early intervention and disease prevention.
Collapse
Affiliation(s)
- R Andrew Tasker
- Department of Biomedical Sciences, University of Prince Edward Island, 550 University Avenue, Charlottetown, PEI, Canada C1A4P3
| | | | | |
Collapse
|
14
|
Abstract
The nonphosphorylated neurofilament marker SMI-32 stains motor neurons in spinal cord slices and stains a subset of cultured spinal neurons ["large SMI-32(+) neurons"], which have a morphology consistent with motor neurons identified in vitro: large cell body, long axon, and extensive dendritic arborization. They are found preferentially in ventral spinal cord cultures, providing further evidence that large SMI-32(+) neurons are indeed motor neurons, and SMI-32 staining often colocalizes with established motor neuron markers (including acetylcholine, calcitonin gene-related peptide, and peripherin). Additionally, choline acetyltransferase activity (a frequently used index of the motor neuron population) and peripherin(+) neurons share with large SMI-32(+) neurons an unusual vulnerability to AMPA/kainate receptor-mediated injury. Kainate-induced loss of these motor neuron markers is Ca2+-dependent, which supports a critical role of Ca2+ ions in this injury. Raising extracellular Ca2+ exacerbates injury, whereas removal of extracellular Ca2+ is protective. A basis for this vulnerability is provided by the observation that most peripherin(+) neurons, like large SMI-32(+) neurons, are subject to kainate-stimulated Co2+ uptake, a histochemical stain that identifies neurons possessing Ca2+-permeable AMPA/kainate receptor-gated channels. Finally, of possibly greater relevance to the slow motor neuronal degeneration in diseases, both large SMI-32(+) neurons and peripherin(+) neurons are selectively damaged by prolonged (24 hr) low-level exposures to kainate (10 microM) or to the glutamate reuptake blocker L-trans-pyrrolidine-2,4-dicarboxylic acid (100 microM). During these low-level kainate exposures, large SMI-32(+) neurons showed higher intracellular Ca2+ concentrations than most spinal neurons, suggesting that Ca2+ ions are also important in this more slowly evolving injury.
Collapse
|