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Ni J, Liu Z, Yuan Y, Li W, Hu Y, Liu P, Hou X, Zhu X, Tang X, Liang M, Zheng S, Hou X, Du J, Tang J, Jiang H, Shen L, Tang B, Wang J. Mitochondrial genome variations are associated with amyotrophic lateral sclerosis in patients from mainland China. J Neurol 2021; 269:805-814. [PMID: 34129120 DOI: 10.1007/s00415-021-10659-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/06/2021] [Accepted: 06/10/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is a late-onset neurodegenerative disorder. Mitochondrial dysfunction is involved in the complex pathophysiology of ALS; however, the role of mitochondrial DNA (mtDNA) variants in ALS is poorly understood. We aimed to elucidate the role of mtDNA variants in the pathogenesis of ALS. METHODS The mitochondrial haplogroups of 585 ALS patients and 371 healthy controls were determined; 38 ALS patients and 42 controls underwent long-range polymerase chain reaction combined with next-generation sequencing technology to analyze whole mitochondrial genome variants. RESULTS A higher percentage of variants accumulated in ALS patients than in controls. Analysis of coding region variations that were further stratified by mtDNA genes revealed that nonsynonymous variants were more vulnerable in ALS patients than in controls, particularly in the ND4L, ND5, and ATP8 genes. Moreover, pathogenic nonsynonymous variants tended to over-represent in ALS patients. Unsurprisingly, nonsynonymous variants were not related to the phenotype. Haplogroup analysis did not found evidence of association between haplogroups with the risk of ALS, however, patients belonging to haplogroup Y and M7c were prone to develop later onset of ALS. CONCLUSIONS This is the first study to profile mtDNA variants in ALS patients from mainland China. Our results suggest that an increase in the number of nonsynonymous variants is linked to the pathogenesis of ALS. Moreover, haplogroup Y and M7c may modulate the clinical expression of ALS. Our findings provide independent, albeit limited, evidence for the role of mtDNA in the pathogenesis of ALS.
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Affiliation(s)
- Jie Ni
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Zhen Liu
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Yanchun Yuan
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Wanzhen Li
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Yiting Hu
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Pan Liu
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Xiaorong Hou
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Xiangyu Zhu
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Xuxiong Tang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Mingyu Liang
- Xiangya School of Medicine, Central South University, Changsha, Hunan, People's Republic of China
| | - Siqi Zheng
- Xiangya School of Medicine, Central South University, Changsha, Hunan, People's Republic of China
| | - Xuan Hou
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Juan Du
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China
| | - Jianguang Tang
- Department of Neurology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China.,Laboratory of Medical Genetics, Central South University, Changsha, Hunan, 410008, People's Republic of China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, People's Republic of China.,National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China
| | - Lu Shen
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China.,Laboratory of Medical Genetics, Central South University, Changsha, Hunan, 410008, People's Republic of China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, People's Republic of China.,National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China.,Laboratory of Medical Genetics, Central South University, Changsha, Hunan, 410008, People's Republic of China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, People's Republic of China.,National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China
| | - Junling Wang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, Hunan, People's Republic of China. .,Laboratory of Medical Genetics, Central South University, Changsha, Hunan, 410008, People's Republic of China. .,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, People's Republic of China. .,National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China.
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Shatunov A, Al-Chalabi A. The genetic architecture of ALS. Neurobiol Dis 2020; 147:105156. [PMID: 33130222 DOI: 10.1016/j.nbd.2020.105156] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/27/2020] [Accepted: 10/27/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
- Aleksey Shatunov
- Department of Basic & Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 9RX, UK
| | - Ammar Al-Chalabi
- Department of Basic & Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 9RX, UK; Department of Neurology, King's College Hospital, London SE5 9RS, UK.
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3
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Western Pacific ALS-PDC: Evidence implicating cycad genotoxins. J Neurol Sci 2020; 419:117185. [PMID: 33190068 DOI: 10.1016/j.jns.2020.117185] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 09/20/2020] [Accepted: 09/29/2020] [Indexed: 12/12/2022]
Abstract
Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex (ALS-PDC) is a disappearing neurodegenerative disorder of apparent environmental origin formerly hyperendemic among Chamorros of Guam-USA, Japanese residents of the Kii Peninsula, Honshu Island, Japan and Auyu-Jakai linguistic groups of Papua-Indonesia on the island of New Guinea. The most plausible etiology is exposure to genotoxins in seed of neurotoxic cycad plants formerly used for food and/or medicine. Primary suspicion falls on methylazoxymethanol (MAM), the aglycone of cycasin and on the non-protein amino acid β-N-methylamino-L-alanine, both of which are metabolized to formaldehyde. Human and animal studies suggest: (a) exposures occurred early in life and sometimes during late fetal brain development, (b) clinical expression of neurodegenerative disease appeared years or decades later, and (c) pathological changes in various tissues indicate the disease was not confined to the CNS. Experimental evidence points to toxic molecular mechanisms involving DNA damage, epigenetic changes, transcriptional mutagenesis, neuronal cell-cycle reactivation and perturbation of the ubiquitin-proteasome system that led to polyproteinopathy and culminated in neuronal degeneration. Lessons learned from research on ALS-PDC include: (a) familial disease may reflect common toxic exposures across generations, (b) primary disease prevention follows cessation of exposure to culpable environmental triggers; and (c) disease latency provides a prolonged period during which to intervene therapeutically. Exposure to genotoxic chemicals ("slow toxins") in the early stages of life should be considered in the search for the etiology of ALS-PDC-related neurodegenerative disorders, including sporadic forms of ALS, progressive supranuclear palsy and Alzheimer's disease.
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Yang H, Zhuang R, Li Y, Li T, Yuan X, Lei B, Xie Y, Wang M. Cold-inducible protein RBM3 mediates hypothermic neuroprotection against neurotoxin rotenone via inhibition on MAPK signalling. J Cell Mol Med 2019; 23:7010-7020. [PMID: 31436914 PMCID: PMC6787511 DOI: 10.1111/jcmm.14588] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/11/2019] [Accepted: 07/24/2019] [Indexed: 12/14/2022] Open
Abstract
Mild hypothermia and its key product, cold-inducible protein RBM3, possess robust neuroprotective effects against various neurotoxins. However, we previously showed that mild hypothermia fails to attenuate the neurotoxicity from MPP+ , one of typical neurotoxins related to the increasing risk of Parkinson disease (PD). To better understand the role of mild hypothermia and RBM3 in PD progression, another known PD-related neurotoxin, rotenone (ROT) was utilized in this study. Using immunoblotting, cell viability assays and TUNEL staining, we revealed that mild hypothermia (32°C) significantly reduced the apoptosis induced by ROT in human neuroblastoma SH-SY5Y cells, when compared to normothermia (37°C). Meanwhile, the overexpression of RBM3 in SH-SY5Y cells mimicked the neuroprotective effects of mild hypothermia on ROT-induced cytotoxicity. Upon ROT stimulation, MAPK signalling like p38, JNK and ERK, and AMPK and GSK-3β signalling were activated. When RBM3 was overexpressed, only the activation of p38, JNK and ERK signalling was inhibited, leaving AMPK and GSK-3β signalling unaffected. Similarly, mild hypothermia also inhibited the activation of MAPKs induced by ROT. Lastly, it was demonstrated that the MAPK (especially p38 and ERK) inhibition by their individual inhibitors significantly decreased the neurotoxicity of ROT in SH-SY5Y cells. In conclusion, these data demonstrate that RBM3 mediates mild hypothermia-related neuroprotection against ROT by inhibiting the MAPK signalling of p38, JNK and ERK.
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Affiliation(s)
- Hai‐Jie Yang
- School of Life Science and TechnologyXinxiang Medical UniversityXinxiangChina
- Henan Key Lab of Biological PsychiatrySecond Affiliated Hospital of Xinxiang Medical UniversityXinxiangChina
| | - Rui‐Juan Zhuang
- School of Pharmaceutical SciencesXiamen UniversityXiamenChina
| | - Yuan‐Bo Li
- School of Life Science and TechnologyXinxiang Medical UniversityXinxiangChina
| | - Tian Li
- School of Life Science and TechnologyXinxiang Medical UniversityXinxiangChina
| | - Xin Yuan
- School of Life Science and TechnologyXinxiang Medical UniversityXinxiangChina
| | - Bing‐Bing Lei
- School of Life Science and TechnologyXinxiang Medical UniversityXinxiangChina
| | - Yun‐Fei Xie
- School of Life Science and TechnologyXinxiang Medical UniversityXinxiangChina
| | - Mian Wang
- School of Life Science and TechnologyXinxiang Medical UniversityXinxiangChina
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Inhibition of store-operated calcium entry attenuates MPP(+)-induced oxidative stress via preservation of mitochondrial function in PC12 cells: involvement of Homer1a. PLoS One 2013; 8:e83638. [PMID: 24358303 PMCID: PMC3866123 DOI: 10.1371/journal.pone.0083638] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 11/05/2013] [Indexed: 12/15/2022] Open
Abstract
The process of store-operated calcium entry (SOCE), whereby the release of intracellular Ca2+ from endoplasmic reticulum (ER) activates Ca2+ influx channels in the plasma membrane, has been demonstrated to impact a diverse range of cell functions. In the present study, we investigated the potential protective effect of SOCE inhibition against 1-methyl-4-phenylpyridinium (MPP+) injury by using pharmacological antagonists or specific small interfering RNA (siRNA) in PC12 cells. The results showed that both antagonists (15 μM MRS-1845 and 50 μM ML-9) and stromal interacting molecule-1 (STIM1) targeted siRNA (Si-STIM1) significantly increased cell viability, decreased apoptotic cell death and reduced intracellular reactive oxygen species (ROS) production and lipid peroxidation in MPP+ injured PC12 cells. SOCE inhibition also prevented MPP+ induced mitochondrial dysfunction and activation of mitochondrial related apoptotic factors, while had no effect on mitochondrial biogenesis. Moreover, inhibition of SOCE by antagonists and siRNA increased the expression levels of Homer1a mRNA and protein, and knockdown of Homer1a expression by specific siRNA partly reversed the protective effects induced by SOCE inhibition in PC12 cells. All these results indicated that SOCE inhibition protected PC12 cells against MPP+ insult through upregulation of Homer1a expression, and SOCE might be an ideal target for investigating therapeutic strategy against neuronal injury in PD patients.
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Factor-Litvak P, Al-Chalabi A, Ascherio A, Bradley W, Chío A, Garruto R, Hardiman O, Kamel F, Kasarskis E, McKee A, Nakano I, Nelson LM, Eisen A. Current pathways for epidemiological research in amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener 2013; 14 Suppl 1:33-43. [PMID: 23678878 PMCID: PMC5434707 DOI: 10.3109/21678421.2013.778565] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease. The current status of the epidemiology, challenges to its study, and novel study design options are discussed in this paper. We focus on recent results from large-scale population based prospective studies, case-control studies and population based registries, risk factors, and neuropathologic findings in chronic traumatic encephalomyelopathy. We identify areas of interest for future research, including time-trends in the incidence and prevalence of ALS; the meaning of lifetime risk; the phenotypic description of ALS; the definition of familial versus sporadic ALS, syndromic aspects of ALS; specific risk factors such as military service, life style factors such as smoking, the use of statins, and the presence of β-N-methylamino-L-alanine (BMAA), an excitotoxic amino acid derivative possibly produced by cyanobacteria found in almost every terrestrial and aquatic habitat; the emergence and disappearance of an endemic ALS in areas of the Pacific; and gene-environment interactions in the etiology of ALS. To move the epidemiology forward, we suggest using well-characterized cohorts of newly diagnosed ALS patients to identify risk and prognostic factors; storing biological material for future studies; building on the National ALS Registry as a resource of future studies; working in multidisciplinary consortia; and addressing the possible early life etiology of ALS.
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Affiliation(s)
- Pam Factor-Litvak
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
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Kihira T, Okamoto K, Yoshida S, Kondo T, Iwai K, Wada S, Kajimoto Y, Kondo T, Kokubo Y, Kuzuhara S. Environmental characteristics and oxidative stress of inhabitants and patients with amyotrophic lateral sclerosis in a high-incidence area on the Kii Peninsula, Japan. Intern Med 2013; 52:1479-86. [PMID: 23812195 DOI: 10.2169/internalmedicine.52.9521] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE Although Oshima, in the Kii Peninsula of Japan, is located within a high incidence area of amyotrophic lateral sclerosis (ALS) (Koza/Kozagawa/Kushimoto area, K area), no patients with ALS were detected between 1960 and 1999. However, the incidence recently increased between 2000 and 2009. On Oshima, the source of drinking water was changed from a regional river/wells to the Kozagawa River in the K area in 1975. We speculate that this change in water source may have played a role in the recent increase in the incidence of ALS. The aim of this study is to find contributing factors that may have triggered the locally high incidence of ALS. METHODS We investigated a possible association between the mineral content of drinking water and serum and oxidative stress markers among patients with ALS in the K area (K-ALS), residents of Oshima and controls. RESULTS We found that the levels of Ca and Zn in the recent drinking water in Oshima are low and that the serum levels of Ca and Zn in the Oshima residents and patients with K-ALS were significantly lower, while the oxidative stress markers were significantly higher, than those of the controls. The serum Zn and urinary 8-OHdG/creatinine levels explained 60% and 58% of the variations among the three groups, respectively. The serum Zn levels were negatively correlated with the serum Cu levels in the patients with K-ALS, and the serum Cu levels exhibited a tendency to be positively correlated with the 8-OHdG/creatinine levels in both the patients with K-ALS (r: 0.64) and the residents free from K-ALS (r: 0.32, p<0.01). CONCLUSION Taken together, we suggest that the low levels of Ca and Zn in the drinking water are possibly associated with an imbalance of metal metabolism in Oshima residents and an increase in oxidative stress markers in patients with K-ALS, although the causative relationship is not clear. This is a cross-sectional study, and a prospective study is needed in the future.
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Affiliation(s)
- Tameko Kihira
- Department of Health Sciences, Kansai University of Health Sciences, Japan.
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Vilar MG, Chan CW, Santos DR, Lynch D, Spathis R, Garruto RM, Lum JK. The origins and genetic distinctiveness of the Chamorros of the Marianas Islands: an mtDNA perspective. Am J Hum Biol 2012. [PMID: 23180676 DOI: 10.1002/ajhb.22349] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Archaeological and linguistic evidence suggests the Marianas Islands were settled around 3,600 years before present (ybp) from Island Southeast Asia (ISEA). Around 1,000 ybp latte stone pillars and the first evidence of rice cultivation appear in the Marianas. Both traditions are absent in the rest of prehistoric Oceania. OBJECTIVE To examine the genetic origins and postsettlement gene flow of Chamorros of the Marianas Islands. METHODS To infer the origins of the Chamorros we analyzed ∼360 base pairs of the hypervariable-region 1 (HVS1) of mitochondrial DNA from 105 Chamorros from Guam, Rota, and Saipan, and the complete mitochondrial genome of 32 Guamanian Chamorros, and compared them to lineages from ISEA and neighboring Pacific archipelagoes from the database. RESULTS Results reveal that 92% of Chamorros belong to haplogroup E, also found in ISEA but rare in Oceania. The two most numerous E lineages were identical to lineages currently found in Indonesia, while the remaining E lineages differed by only one or two mutations and all were unique to the Marianas. Seven percent of the lineages belonged to a single Chamorro-specific lineage within haplogroup B4, common to ISEA as well as Micronesia and Polynesia. CONCLUSIONS These patterns suggest a small founding population had reached and settled the Marianas from ISEA by 4,000 ybp, and developed unique mutations in isolation. A second migration from ISEA may have arrived around 1,000 ybp, introducing the latte pillars, rice agriculture and the homogeneous minority B4 lineage.
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Affiliation(s)
- Miguel G Vilar
- Department of Anthropology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA.
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Inherited and somatic mitochondrial DNA mutations in Guam amyotrophic lateral sclerosis and parkinsonism-dementia. Neurol Sci 2011; 32:883-92. [PMID: 21822691 DOI: 10.1007/s10072-011-0735-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 07/21/2011] [Indexed: 02/04/2023]
Abstract
There is increasing evidence for mitochondrial dysfunction in neurodegenerative disorders, although the exact role of mitochondrial DNA (mtDNA) mutations in this process is unresolved. We investigated inherited and somatic mtDNA substitutions and deletions in Guam amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD). Hypervariable segment 1 sequences of Chamorro mtDNA revealed that the odds ratio of a PD or ALS diagnosis was increased for individuals in the E1 haplogroup while individuals in the E2 haplogroup had decreased odds of an ALS or PD diagnosis. Once the disorders were examined separately, it became evident that PD was responsible for these results. When the entire mitochondrial genome was sequenced for a subset of individuals, the nonsynonymous mutation at nucleotide position 9080, shared by all E2 individuals, resulted in a significantly low odds ratio for a diagnosis of ALS or PD. Private polymorphisms found in transfer and ribosomal RNA regions were found only in ALS and PD patients in the E1 haplogroup. Somatic mtDNA deletions in the entire mtDNA genome were not associated with either ALS or PD. We conclude that mtDNA haplogroup effects may result in mitochondrial dysfunction in Guam PD and reflect Guam population history. Thus it is reasonable to consider Guam ALS and PD as complex disorders with both environmental prerequisites and small genetic effects.
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Metabotropic glutamate receptor 1 mediates the electrophysiological and toxic actions of the cycad derivative beta-N-Methylamino-L-alanine on substantia nigra pars compacta DAergic neurons. J Neurosci 2010; 30:5176-88. [PMID: 20392940 DOI: 10.1523/jneurosci.5351-09.2010] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Amyotrophic lateral sclerosis-Parkinson dementia complex (ALS-PDC) is a neurodegenerative disease with ALS, parkinsonism, and Alzheimer's symptoms that is prevalent in the Guam population. beta-N-Methylamino alanine (BMAA) has been proposed as the toxic agent damaging several neuronal types in ALS-PDC, including substantia nigra pars compacta dopaminergic (SNpc DAergic) neurons. BMAA is a mixed glutamate receptor agonist, but the specific pathways activated in DAergic neurons are not yet known. We combined electrophysiology, microfluorometry, and confocal microscopy analysis to monitor membrane potential/current, cytosolic calcium concentration ([Ca(2+)](i)) changes, cytochrome-c (cyt-c) immunoreactivity, and reactive oxygen species (ROS) production induced by BMAA. Rapid toxin applications caused reversible membrane depolarization/inward current and increase of firing rate and [Ca(2+)](i) in DAergic neurons. The inward current (I(BMAA)) was mainly mediated by activation of metabotropic glutamate receptor 1 (mGluR1), coupled to transient receptor potential (TRP) channels, and to a lesser extent, AMPA receptors. Indeed, mGluR1 (CPCCOEt) and TRP channels (SKF 96365; Ruthenium Red) antagonists reduced I(BMAA), and a small component of I(BMAA) was reduced by the AMPA receptor antagonist CNQX. Calcium accumulation was mediated by mGluR1 but not by AMPA receptors. Application of a low concentration of NMDA potentiated the BMAA-mediated calcium increase. Prolonged exposure to BMAA caused significant modifications of membrane properties, calcium overload, cell shrinkage, massive cyt-c release into the cytosol and ROS production. In SNpc GABAergic neurons, BMAA activated only AMPA receptors. Our study identifies the mGluR1-activated mechanism induced by BMAA that may cause the neuronal degeneration and parkinsonian symptoms seen in ALS-PDC. Moreover, environmental exposure to BMAA might possibly also contribute to idiopathic PD.
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McKnight AJ, Currie D, Maxwell AP. Unravelling the genetic basis of renal diseases; from single gene to multifactorial disorders. J Pathol 2010; 220:198-216. [PMID: 19882676 DOI: 10.1002/path.2639] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chronic kidney disease is common with up to 5% of the adult population reported to have an estimated glomerular filtration rate of < 60 ml/min/1.73 m(2). A large number of pathogenic mutations have been identified that are responsible for 'single gene' renal disorders, such as autosomal dominant polycystic kidney disease and X-linked Alport syndrome. These single gene disorders account for < 15% of the burden of end-stage renal disease that requires dialysis or kidney transplantation. It has proved more difficult to identify the genetic susceptibility underlying common, complex, multifactorial kidney conditions, such as diabetic nephropathy and hypertensive nephrosclerosis. This review describes success to date and explores strategies currently employed in defining the genetic basis for a number of renal disorders. The complementary use of linkage studies, candidate gene and genome-wide association analyses are described and a collation of renal genetic resources highlighted.
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Affiliation(s)
- Amy J McKnight
- Nephrology Research Group, Queen's University of Belfast, Belfast BT9 7AB, Northern Ireland, UK
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Sieh W, Choi Y, Chapman NH, Craig UK, Steinbart EJ, Rothstein JH, Oyanagi K, Garruto RM, Bird TD, Galasko DR, Schellenberg GD, Wijsman EM. Identification of novel susceptibility loci for Guam neurodegenerative disease: challenges of genome scans in genetic isolates. Hum Mol Genet 2009; 18:3725-38. [PMID: 19567404 PMCID: PMC2742398 DOI: 10.1093/hmg/ddp300] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 06/17/2009] [Accepted: 06/25/2009] [Indexed: 12/17/2022] Open
Abstract
Amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) is a fatal neurodegenerative disease found in the Chamorro people of Guam and other Pacific Island populations. The etiology is unknown, although both genetic and environmental factors appear important. To identify loci for ALS/PDC, we conducted both genome-wide linkage and association analyses, using approximately 400 microsatellite markers, in the largest sample assembled to date, comprising a nearly complete sample of all living and previously sampled deceased cases. A single, large, complex pedigree was ascertained from a village on Guam, with smaller families and a case-control sample ascertained from the rest of Guam by population-based neurological screening and archival review. We found significant evidence for two regions with novel ALS/PDC loci on chromosome 12 and supportive evidence for the involvement of the MAPT region on chromosome 17. D12S1617 on 12p gave the strongest evidence of linkage (maximum LOD score, Z(max) = 4.03) in our initial scan, with additional support in the complete case-control sample in the form of evidence of allelic association at this marker and another nearby marker. D12S79 on 12q also provided significant evidence of linkage (Z(max) = 3.14) with support from flanking markers. Our results suggest that ALS/PDC may be influenced by as many as three loci, while illustrating challenges that are intrinsic in genetic analyses of isolated populations, as well as analytical strategies that are useful in this context. Elucidation of the genetic basis of ALS/PDC should improve our understanding of related neurodegenerative disorders including Alzheimer disease, Parkinson disease, frontotemporal dementia and ALS.
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Affiliation(s)
- Weiva Sieh
- Division of Medical Genetics, Department of Medicine
- Division of Epidemiology, Department of Health Research and Policy, Stanford University, Stanford, CA 94305, USA
| | | | | | - Ulla-Katrina Craig
- Micronesian Health and Aging Study, University of Guam, Mangilao, Guam 96923, USA
| | - Ellen J. Steinbart
- Department of Neurology
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | | | - Kiyomitsu Oyanagi
- Department of Neuropathology, Tokyo Metropolitan Institute for Neuroscience, Tokyo, Japan
| | - Ralph M. Garruto
- Laboratory of Biomedical Anthropology and Neurosciences, Department of Anthropology, Binghamton University, Binghamton, NY 13902, USA
| | - Thomas D. Bird
- Division of Medical Genetics, Department of Medicine
- Department of Neurology
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Douglas R. Galasko
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA and
| | - Gerard D. Schellenberg
- Department of Neurology
- Division of Gerontology and Geriatric Medicine, Department of Medicine
- Department of Pharmacology and
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ellen M. Wijsman
- Division of Medical Genetics, Department of Medicine
- Department of Biostatistics
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
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Altered functional properties of a TRPM2 variant in Guamanian ALS and PD. Proc Natl Acad Sci U S A 2008; 105:18029-34. [PMID: 19004782 DOI: 10.1073/pnas.0808218105] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two related neurodegenerative disorders, Western Pacific amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD), originally occurred at a high incidence on Guam, in the Kii peninsula of Japan, and in southern West New Guinea more than 50 years ago. These three foci shared a unique mineral environment characterized by the presence of severely low levels of Ca(2+) and Mg(2+), coupled with high levels of bioavailable transition metals in the soil and drinking water. Epidemiological studies suggest that genetic factors also contribute to the etiology of these disorders. Here, we report that a variant of the transient receptor potential melastatin 2 (TRPM2) gene may confer susceptibility to these diseases. TRPM2 encodes a calcium-permeable cation channel highly expressed in the brain that has been implicated in mediating cell death induced by oxidants. We found a heterozygous variant of TRPM2 in a subset of Guamanian ALS (ALS-G) and PD (PD-G) cases. This variant, TRPM2(P1018L), produces a missense change in the channel protein whereby proline 1018 (Pro(1018)) is replaced by leucine (Leu(1018)). Functional studies revealed that, unlike WT TRPM2, P1018L channels inactivate. Our results suggest that the ability of TRPM2 to maintain sustained ion influx is a physiologically important function and that its disruption may, under certain conditions, contribute to disease states.
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Vilar MG, Kaneko A, Hombhanje FW, Tsukahara T, Hwaihwanje I, Lum JK. Reconstructing the origin of the Lapita Cultural Complex: mtDNA analyses of East Sepik Province, PNG. J Hum Genet 2008; 53:698-708. [PMID: 18498001 DOI: 10.1007/s10038-008-0301-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 04/29/2008] [Indexed: 10/22/2022]
Abstract
The colonization of Oceania occurred in two waves. By 32,000 BP, humans had reached New Guinea and settled all intervisible islands east to the Solomon Islands. Around 3,500 BP, a distinct intrusive group from Southeast Asia reached coastal New Guinea, integrated their components with indigenous resources, and gave rise to the Lapita Cultural Complex. Within 2,500 years, Lapita and its descendant cultures colonized the Pacific. To uncover the origin of the Lapita Cultural Complex, we analyzed the hypervariable region I of the mitochondrial deoxyribonucleic acid (mtDNA) in 219 individuals from eight East Sepik Province villages: two villages in each of four environmental zones. Same-zone villages spoke different languages: one Austronesian and three Papuan (Arapesh, Abelam, and Boiken). Our analysis examined whether language or geography better predicted gene flow. In general, language better predicted genetic affinities. Boiken villages across all four zones showed no significant genetic difference (F(ST) P value > 0.05). In contrast, the Austronesian village was significantly different to most other villages (P < 0.05). Only the mountains and coast showed zonal gene flow (P > 0.05). We interpret the data to reflect limited gene flow inland by Austronesians overshadowed by a regional displacement by inland Boiken speakers migrating seaward. These results are consistent with oral histories and ethnographic accounts.
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Affiliation(s)
- Miguel G Vilar
- Laboratory of Evolutionary Anthropology and Health, Binghamton University, Binghamton, NY, USA. .,Department of Anthropology, Binghamton University, Binghamton, NY, 13902-6000, USA.
| | - Akira Kaneko
- Malaria Research Unit, Unit for Infectious Diseases, Department of Medicine, Karolinska University Hospital, Stockholm, Sweden.,Department of International Affairs and Tropical Medicine, Tokyo's Women's Medical University, Tokyo, Japan
| | - Francis W Hombhanje
- Faculty of Health Sciences, Divine Word University, Madang, Papua New Guinea
| | - Takahiro Tsukahara
- Department of International Affairs and Tropical Medicine, Tokyo's Women's Medical University, Tokyo, Japan
| | | | - J Koji Lum
- Laboratory of Evolutionary Anthropology and Health, Binghamton University, Binghamton, NY, USA.,Department of Anthropology, Binghamton University, Binghamton, NY, 13902-6000, USA.,Department of Biological Sciences, Binghamton University, Binghamton, NY, USA
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