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Congdon EE, Pan R, Jiang Y, Sandusky-Beltran LA, Dodge A, Lin Y, Liu M, Kuo MH, Kong XP, Sigurdsson EM. Single domain antibodies targeting pathological tau protein: Influence of four IgG subclasses on efficacy and toxicity. EBioMedicine 2022; 84:104249. [PMID: 36099813 PMCID: PMC9475275 DOI: 10.1016/j.ebiom.2022.104249] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/15/2022] [Accepted: 08/19/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Eleven tau immunoglobulin G (IgG) antibodies have entered clinical trials to treat tauopathies, including Alzheimer's disease, but it is unclear which IgG subclass/subtype has the ideal efficacy and safety profile. Only two subtypes, with or without effector function, have been examined in the clinic and not for the same tau antibody. The few preclinical studies on this topic have only compared two subtypes of one antibody each and have yielded conflicting results. METHODS We selected two single domain antibodies (sdAbs) derived from a llama immunized with tau proteins and utilized them to generate an array of Fc-(sdAb)2 subclasses containing identical tau binding domains but differing Fc region. Unmodified sdAbs and their IgG subclasses were tested for efficacy in primary cultures and in vivo microdialysis using JNPL3 tauopathy mice. FINDINGS Unmodified sdAbs were non-toxic, blocked tau toxicity and promoted tau clearance. However, the efficacy/safety profile of their Fc-(sdAb)2 subclasses varied greatly within and between sdAbs. For one of them, all its subtypes were non-toxic, only those with effector function cleared tau, and were more effective in vivo than unmodified sdAb. For the other sdAb, all its subtypes were toxic in tauopathy cultures but not in wild-type cells, suggesting that bivalent binding of its tau epitope stabilizes a toxic conformation of tau, with major implications for tau pathogenesis. Likewise, its subclasses were less effective than the unmodified sdAb in clearing tau in vivo. INTERPRETATION These findings indicate that tau antibodies with effector function are safe and better at clearing pathological tau than effectorless antibodies, Furthermore, tau antibodies can provide a valuable insight into tau pathogenesis, and some may aggravate it. FUNDING Funding for these studies was provided by the National Institute of Health (R01 AG032611, R01 NS077239, RF1 NS120488, R21 AG 069475, R21 AG 058282, T32AG052909), and the NYU Alzheimer's Disease Center Pilot Grant Program (via P30 AG008051).
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Affiliation(s)
- Erin E Congdon
- Department of Neuroscience and Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine, 435 East 30th Street, New York, NY 10016, USA
| | - Ruimin Pan
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Yixiang Jiang
- Department of Neuroscience and Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine, 435 East 30th Street, New York, NY 10016, USA
| | - Leslie A Sandusky-Beltran
- Department of Neuroscience and Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine, 435 East 30th Street, New York, NY 10016, USA
| | - Andie Dodge
- Department of Neuroscience and Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine, 435 East 30th Street, New York, NY 10016, USA
| | - Yan Lin
- Department of Neuroscience and Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine, 435 East 30th Street, New York, NY 10016, USA
| | - Mengyu Liu
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, Room 401, East Lansing, MI, 48824, USA
| | - Min-Hao Kuo
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, Room 401, East Lansing, MI, 48824, USA
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Einar M Sigurdsson
- Department of Neuroscience and Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine, 435 East 30th Street, New York, NY 10016, USA; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY 10016, USA.
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Shamir DB, Deng Y, Wu Q, Modak S, Congdon EE, Sigurdsson EM. Dynamics of Internalization and Intracellular Interaction of Tau Antibodies and Human Pathological Tau Protein in a Human Neuron-Like Model. Front Neurol 2020; 11:602292. [PMID: 33324339 PMCID: PMC7727311 DOI: 10.3389/fneur.2020.602292] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023] Open
Abstract
We and others have shown in various in vivo, ex vivo and cell culture models that several tau antibodies interact with pathological tau within neurons. To further clarify this interaction in a dynamic human model, we differentiated SH-SY5Y cells with retinoic acid and BDNF to create a neuron-like model. Therein, tau antibodies were primarily taken up by receptor-mediated endocytosis, and prevented toxicity of human brain-derived paired helical filament-enriched tau (PHF). Subsequently, we monitored in real-time the interaction of antibodies and PHF within endocytic cellular compartments. Cells were pre-treated with fluorescently-tagged PHF and then incubated with tau antibodies, 4E6, 6B2, or non-specific isotype control IgG1 labeled with a pH sensitive dye. The uptake and binding of the efficacious antibody, 4E6, to PHF occurred mainly within the soma, whereas the ineffective antibody, 6B2, and ineffective control IgG1, were visualized via the processes and showed limited colocalization with PHF within this period. In summary, we have developed a neuron-like model that clarifies the early intracellular dynamics of the interaction of tau antibodies with pathological tau, and identifies features associated with efficacy. Since the model is entirely human, it is suitable to verify the therapeutic potential of humanized antibodies prior to extensive clinical trials.
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Affiliation(s)
- Dov B Shamir
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
| | - Yan Deng
- Microscopy Core, New York University Grossman School of Medicine, New York, NY, United States
| | - Qian Wu
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
| | - Swananda Modak
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
| | - Erin E Congdon
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
| | - Einar M Sigurdsson
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States.,Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
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Kovaleva TF, Maksimova NS, Zhukov IY, Pershin VI, Mukhina IV, Gainullin MR. Cofilin: Molecular and Cellular Functions and Its Role in the Functioning of the Nervous System. NEUROCHEM J+ 2019. [DOI: 10.1134/s1819712419010124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Tanshinone IIA increases levels of NeuN, protein disulfide isomerase, and Na+/K+-ATPase and decreases evidence of microglial activation after cerebral ischemic injury. Neuroreport 2016; 27:435-44. [PMID: 26966780 DOI: 10.1097/wnr.0000000000000559] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This study was designed to clarify the neuroprotective effects of tanshinone IIA (TSA) following cerebral ischemic insult. Adult Sprague-Dawley rats were operated upon to achieve a middle cerebral artery occlusion to cause transient focal cerebral ischemia, which were then randomly divided into the sham-operated control group and cerebral ischemia/reperfusion (I/R) groups receiving a 2 h occlusion. The treatment groups received daily intraperitoneal injections of high or low doses of TSA, for 7 or 15 days. NeuN immunostaining revealed neuronal loss following I/R, which was partially prevented with subsequent TSA dosing. Protein disulfide isomerase and adenosine triphosphatase (Na(+)/K(+)-ATPase) levels were all depressed by means of I/R. TSA treatment markedly reversed the depression of all indices examined. The intensity of microglial activation, as evidenced with CD11b staining, was increased by means of cerebral artery occlusion, but this was partially reversed with subsequent TSA treatment. TSA may affect neuroprotection by way of minimizing deficits in energy metabolism and reduction of the extent of cell death within affected regions.
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Congdon EE, Lin Y, Rajamohamedsait HB, Shamir DB, Krishnaswamy S, Rajamohamedsait WJ, Rasool S, Gonzalez V, Levenga J, Gu J, Hoeffer C, Sigurdsson EM. Affinity of Tau antibodies for solubilized pathological Tau species but not their immunogen or insoluble Tau aggregates predicts in vivo and ex vivo efficacy. Mol Neurodegener 2016; 11:62. [PMID: 27578006 PMCID: PMC5006503 DOI: 10.1186/s13024-016-0126-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/04/2016] [Indexed: 11/10/2022] Open
Abstract
Background A few tau immunotherapies are now in clinical trials with several more likely to be initiated in the near future. A priori, it can be anticipated that an antibody which broadly recognizes various pathological tau aggregates with high affinity would have the ideal therapeutic properties. Tau antibodies 4E6 and 6B2, raised against the same epitope region but of varying specificity and affinity, were tested for acutely improving cognition and reducing tau pathology in transgenic tauopathy mice and neuronal cultures. Results Surprisingly, we here show that one antibody, 4E6, which has low affinity for most forms of tau acutely improved cognition and reduced soluble phospho-tau, whereas another antibody, 6B2, which has high affinity for various tau species was ineffective. Concurrently, we confirmed and clarified these efficacy differences in an ex vivo model of tauopathy. Alzheimer’s paired helical filaments (PHF) were toxic to the neurons and increased tau levels in remaining neurons. Both toxicity and tau seeding were prevented by 4E6 but not by 6B2. Furthermore, 4E6 reduced PHF spreading between neurons. Interestingly, 4E6’s efficacy relates to its high affinity binding to solubilized PHF, whereas the ineffective 6B2 binds mainly to aggregated PHF. Blocking 4E6's uptake into neurons prevented its protective effects if the antibody was administered after PHF had been internalized. When 4E6 and PHF were administered at the same time, the antibody was protective extracellularly. Conclusions Overall, these findings indicate that high antibody affinity for solubilized PHF predicts efficacy, and that acute antibody-mediated improvement in cognition relates to clearance of soluble phospho-tau. Importantly, both intra- and extracellular clearance pathways are in play. Together, these results have major implications for understanding the pathogenesis of tauopathies and for development of immunotherapies. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0126-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Erin E Congdon
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Yan Lin
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Hameetha B Rajamohamedsait
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Dov B Shamir
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Senthilkumar Krishnaswamy
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Wajitha J Rajamohamedsait
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Suhail Rasool
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Veronica Gonzalez
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Josien Levenga
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA.,Department of Integrative Physiology, Institute for Behavioral Genetics, University of Colorado, Boulder, CO, 80309, USA
| | - Jiaping Gu
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA
| | - Charles Hoeffer
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA.,Department of Integrative Physiology, Institute for Behavioral Genetics, University of Colorado, Boulder, CO, 80309, USA
| | - Einar M Sigurdsson
- Departments of Neuroscience and Physiology, New York University School of Medicine, Medical Science Building, MSB459, 550 First Avenue, New York, NY, 10016, USA. .,Departments of Psychiatry, New York University School of Medicine, New York, NY, 10016, USA.
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Adil M, Kandhare AD, Ghosh P, Bodhankar SL. Sodium arsenite-induced myocardial bruise in rats: Ameliorative effect of naringin via TGF-β/Smad and Nrf/HO pathways. Chem Biol Interact 2016; 253:66-77. [DOI: 10.1016/j.cbi.2016.05.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/24/2016] [Accepted: 05/08/2016] [Indexed: 01/06/2023]
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The Functional and Molecular Properties, Physiological Functions, and Pathophysiological Roles of GluN2A in the Central Nervous System. Mol Neurobiol 2016; 54:1008-1021. [DOI: 10.1007/s12035-016-9715-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 01/11/2016] [Indexed: 11/25/2022]
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Cofilin as a Promising Therapeutic Target for Ischemic and Hemorrhagic Stroke. Transl Stroke Res 2015; 7:33-41. [PMID: 26670926 DOI: 10.1007/s12975-015-0438-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/01/2015] [Accepted: 12/03/2015] [Indexed: 01/22/2023]
Abstract
Neurovascular unit (NVU) is considered as a conceptual framework for investigating the mechanisms as well as developing therapeutic targets for ischemic and hemorrhagic stroke. From a molecular perspective, oxidative stress, excitotoxicity, inflammation, and disruption of the blood brain barrier are broad pathophysiological frameworks on the basis on which potential therapeutic candidates for ischemic and hemorrhagic stroke could be discussed. Cofilin is a potent actin-binding protein that severs and depolymerizes actin filaments in order to generate the dynamics of the actin cytoskeleton. Although studies of the molecular mechanisms of cofilin-induced reorganization of the actin cytoskeleton have been ongoing for decades, the multicellular functions of cofilin and its regulation in different molecular pathways are expanding beyond its primary role in actin cytoskeleton. This review focuses on the role of cofilin in oxidative stress, excitotoxicity, inflammation, and disruption of the blood brain barrier in the context of NVU as well as how and why cofilin could be studied further as a potential target for ischemic and hemorrhagic stroke.
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Adil M, Kandhare AD, Visnagri A, Bodhankar SL. Naringin ameliorates sodium arsenite-induced renal and hepatic toxicity in rats: decisive role of KIM-1, Caspase-3, TGF-β, and TNF-α. Ren Fail 2015; 37:1396-407. [PMID: 26337322 DOI: 10.3109/0886022x.2015.1074462] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Chronic exposure of a naturally occurring metal arsenic leads to renal and hepatic diseases. Naringin, a flavanone glycoside, possesses anti-inflammatory and anti-oxidant potential. The aim of this investigation was to evaluate the protective effect of naringin against arsenic-induced renal and hepatic toxicity in rats. Renal and hepatic toxicity was induced in rats by sodium arsenite (5 mg/kg, p.o.). Rats were treated orally with either vehicle or naringin (20, 40, and 80 mg/kg) or Coenzyme Q10 (10 mg/kg) for 28 days. Various biochemical, histological, and molecular biomarkers were assessed in kidney and liver. Treatment with naringin (40 and 80 mg/kg) significantly and dose-dependently restored (p < 0.01 and p < 0.001) altered levels of kidney (serum creatinine, urine creatinine, BUN, uric acid, and creatinine clearance) and liver function test (AST and ALT) induced by sodium arsenite. Elevated levels of oxido-nitrosative stress in renal and hepatic tissue was significantly and dose-dependently decreased (p < 0.01 and p < 0.001) by naringin (40 and 80 mg/kg) treatment. It significantly and dose-dependently down-regulated (p < 0.01 and p < 0.001) renal KIM-1, Caspase-3, TGF-β, and TNF-α mRNA expression. Histopathological alteration induced in kidney and liver by sodium arsenite was reduced by naringin (40 and 80 mg/kg) treatment. In conclusion, naringin treatment ameliorates arsenic-induced renal and hepatic damage in rats due its antioxidant and anti-inflammatory properties via down-regulation of elevated oxido-nitrosative stress, KIM-1, Caspase-3, TGF-β, and TNF-α levels.
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Affiliation(s)
- Mohammad Adil
- a Department of Pharmacology , Poona College of Pharmacy, Bharati Vidyapeeth Deemed University , Pune , Maharashtra , India
| | - Amit D Kandhare
- a Department of Pharmacology , Poona College of Pharmacy, Bharati Vidyapeeth Deemed University , Pune , Maharashtra , India
| | - Asjad Visnagri
- a Department of Pharmacology , Poona College of Pharmacy, Bharati Vidyapeeth Deemed University , Pune , Maharashtra , India
| | - Subhash L Bodhankar
- a Department of Pharmacology , Poona College of Pharmacy, Bharati Vidyapeeth Deemed University , Pune , Maharashtra , India
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Li JB, Cheng RD, Zhou L, Wen WS, Zhu GY, Tian L, Ye XM. What drives progressive motor deficits in patients with acute pontine infarction? Neural Regen Res 2015; 10:501-4. [PMID: 25878603 PMCID: PMC4396117 DOI: 10.4103/1673-5374.153703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2014] [Indexed: 11/16/2022] Open
Abstract
Progressive motor deficits are relatively common in acute pontine infarction and frequently associated with increased functional disability. However, the factors that affect the progression of clinical motor weakness are largely unknown. Previous studies have suggested that pontine infarctions are caused mainly by basilar artery stenosis and penetrating artery disease. Recently, lower pons lesions in patients with acute pontine infarctions have been reported to be related to progressive motor deficits, and ensuing that damage to the corticospinal tracts may be responsible for the worsening of neurological symptoms. Here, we review studies on motor weakness progression in pontine infarction and discuss the mechanisms that may underlie the neurologic worsening.
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Affiliation(s)
- Jue-Bao Li
- Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang Province, China
| | - Rui-Dong Cheng
- Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang Province, China
| | - Liang Zhou
- Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang Province, China
| | - Wan-Shun Wen
- Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang Province, China
| | - Gen-Ying Zhu
- Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang Province, China
| | - Liang Tian
- Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang Province, China
| | - Xiang-Ming Ye
- Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang Province, China
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Harriott AM, Dueker N, Cheng YC, Ryan KA, O'Connell JR, Stine OC, McArdle PF, Wozniak MA, Stern BJ, Mitchell BD, Kittner SJ, Cole JW. Polymorphisms in migraine-associated gene, atp1a2, and ischemic stroke risk in a biracial population: the genetics of early onset stroke study. SPRINGERPLUS 2013; 2:46. [PMID: 23459313 PMCID: PMC3582818 DOI: 10.1186/2193-1801-2-46] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 01/29/2013] [Indexed: 11/10/2022]
Abstract
In a recent meta-analysis migraine was associated with a two-fold increase in stroke risk. While the mechanism driving this association is unknown, one intriguing hypothesis is that migraineurs are genetically predisposed to developing ischemic stroke. Mutations in the ATP1A2 gene are implicated in familial hemiplegic migraine type II and increase the severity of ischemic brain injury in animal models. To further explore these observations, we assessed the association between ATP1A2 polymorphisms, migraine, and the risk of ischemic stroke in participants of the Genetics of Early-Onset Stroke Study, a population-based case-control study of ischemic stroke among men and women aged 15-49. Using responses to a headache symptoms questionnaire, subjects were classified as having no migraine, or migraine with or without visual aura. Evaluating a total of 134 ATP1A2 polymorphisms genotyped using a combination of Illumina platforms (Cardiovascular Gene-centric 50 K SNP Array and HumanOmni1-Quad_v1-0_B Bead Chip), only one polymorphism (rs2070704) demonstrated a nominally significant association with stroke in an age-, gender-, ethnicity-adjusted model (OR = 0.83, 95% CI = 0.71-0.98, p = 0.025) and in a vascular risk factor model adjusting for age, gender, ethnicity, hypertension, diabetes, smoking, and myocardial infarction (OR = 0.74, 95% CI = 0.63-0.89, p = 0.001). Ethnicity-stratified analyses demonstrated a significant association for rs2070704 among African-Americans (OR = 0.68, 95% CI = 0.53-0.90, p = 0.005) but not Caucasians (OR = 0.82, 95% CI = 0.64-1.04, p = 0.107). These associations were unchanged when migraine subtypes were included as co-variates. We did not observe an association between ATP1A2 polymorphisms and migraine. While our results do not demonstrate a strong relationship between ATP1A2 polymorphisms and migraine associated stroke risk, the results are hypothesis generating and indicate that an association between ATP1A2 polymorphisms and stroke risk may exist. Additional studies are required.
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Affiliation(s)
- Andrea M Harriott
- School of Medicine, University of Maryland, Baltimore, 655 W. Baltimore St, Baltimore, MD 21201 USA
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Cao N, Yao ZX. Oligodendrocyte N-methyl-D-aspartate receptor signaling: insights into its functions. Mol Neurobiol 2013; 47:845-56. [PMID: 23345133 DOI: 10.1007/s12035-013-8408-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 01/13/2013] [Indexed: 12/21/2022]
Abstract
Myelination by oligodendrocytes facilitates rapid nerve conduction. Loss of oligodendrocytes and failure of myelination lead to nerve degeneration and numerous demyelinating white matter diseases. N-methyl-D-aspartate (NMDA) receptors, which are key regulators on neuron survival and functions, have been recently identified to express in oligodendrocytes, especially in the myelin sheath. NMDA receptor signaling in oligodendrocytes plays crucial roles in energy metabolism and myelination. In the present review, we highlight the subcellular location-specific impairment of excessive NMDA receptor signaling on oligodendrocyte energy metabolism in soma and myelin, and the mechanisms including Ca(2+) overload, acidotoxicity, mitochondria dysfunction, and impairment of respiratory chains. Conversely, physiological NMDA receptor signaling regulates differentiation and migration of oligodendrocytes. How can we use above knowledge to treat excitotoxic oligodendrocyte loss, congenital myelination deficiency, or postnatal demyelination? A thorough understanding of NMDA receptor signaling-mediated cellular events in oligodendrocytes at the pathophysiological level will no doubt aid in exploring effective therapeutic strategies for demyelinating white matter diseases.
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Affiliation(s)
- Nian Cao
- Department of Physiology, Third Military Medical University, Chongqing 400038, China
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Bhattacharya A, Dhar P, Mehra RD. Preliminary morphological and biochemical changes in rat liver following postnatal exposure to sodium arsenite. Anat Cell Biol 2012; 45:229-40. [PMID: 23301191 PMCID: PMC3531587 DOI: 10.5115/acb.2012.45.4.229] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 09/15/2012] [Accepted: 10/25/2012] [Indexed: 12/13/2022] Open
Abstract
The effects of sodium arsenite exposure on the hepatic maturation period of cellular and functional reorganization in developing rat livers were evaluated. Animals received intraperitoneal injections of sodium arsenite (1.5 mg/kg body weight) or distilled water on days 9 to 28 after birth. On day 29, the animals were sacrificed either by cervical dislocation or by perfusion fixation. The perfusion fixed liver tissue was processed for paraffin embedding, sectioning and hematoxylin and eosin staining. The fresh liver tissue was processed for cryo-sectioning followed by Sudan Black B staining and for biochemical estimation of reduced glutathione. Microscopic observation revealed comparable preserved hepatic lobular patterns and distributions of uninucleate and binucleate hepatocytes in the control and the experimental groups. The mean nuclear area and diameter of the hepatocytes was increased in the experimental group. Lipid droplet distribution pattern in Sudan Black B stained sections revealed higher staining intensity towards the centrilobular area in both groups. Semiquantitative estimation of staining intensity showed lower mean gray values in zone 3 than in zones 2 and 1 (suggestive of the setting in of the adult pattern) in both groups. The reduced glutathione levels in the liver tissue and the altered nuclear size of the hepatocytes in the experimental group suggested the impairment of morphological and biochemical processes induced by arsenic exposure during the postnatal period.
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Affiliation(s)
- Arnab Bhattacharya
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
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