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Munk P, Brinch C, Møller FD, Petersen TN, Hendriksen RS, Seyfarth AM, Kjeldgaard JS, Svendsen CA, van Bunnik B, Berglund F, Larsson DGJ, Koopmans M, Woolhouse M, Aarestrup FM, Gibb K, Coventry K, Collignon P, Cassar S, Allerberger F, Begum A, Hossain ZZ, Worrell C, Vandenberg O, Pieters I, Victorien DT, Gutierrez ADS, Soria F, Grujić VR, Mazalica N, Rahube TO, Tagliati CA, Rodrigues D, Oliveira G, de Souza LCR, Ivanov I, Juste BI, Oumar T, Sopheak T, Vuthy Y, Ngandjio A, Nzouankeu A, Olivier ZAAJ, Yost CK, Kumar P, Brar SK, Tabo DA, Adell AD, Paredes-Osses E, Martinez MC, Cuadros-Orellana S, Ke C, Zheng H, Baisheng L, Lau LT, Chung T, Jiao X, Yu Y, JiaYong Z, Morales JFB, Valencia MF, Donado-Godoy P, Coulibaly KJ, Hrenovic J, Jergović M, Karpíšková R, Deogratias ZN, Elsborg B, Hansen LT, Jensen PE, Abouelnaga M, Salem MF, Koolmeister M, Legesse M, Eguale T, Heikinheimo A, Le Guyader S, Schaeffer J, Villacis JE, Sanneh B, Malania L, Nitsche A, Brinkmann A, Schubert S, Hesse S, Berendonk TU, Saba CKS, Mohammed J, Feglo PK, Banu RA, Kotzamanidis C, Lytras E, Lickes SA, Kocsis B, Solymosi N, Thorsteinsdottir TR, Hatha AM, Ballal M, Bangera SR, Fani F, Alebouyeh M, Morris D, O’Connor L, Cormican M, Moran-Gilad J, Battisti A, Diaconu EL, Corno G, Di Cesare A, Alba P, Hisatsune J, Yu L, Kuroda M, Sugai M, Kayama S, Shakenova Z, Kiiyukia C, Ng’eno E, Raka L, Jamil K, Fakhraldeen SA, Alaati T, Bērziņš A, Avsejenko J, Kokina K, Streikisa M, Bartkevics V, Matar GM, Daoud Z, Pereckienė A, Butrimaite-Ambrozeviciene C, Penny C, Bastaraud A, Rasolofoarison T, Collard JM, Samison LH, Andrianarivelo MR, Banda DL, Amin A, Rajandas H, Parimannan S, Spiteri D, Haber MV, Santchurn SJ, Vujacic A, Djurovic D, Bouchrif B, Karraouan B, Vubil DC, Pal P, Schmitt H, van Passel M, Jeunen GJ, Gemmell N, Chambers ST, Mendoza FP, Huete-Pιrez J, Vilchez S, Ahmed AO, Adisa IR, Odetokun IA, Fashae K, Sørgaard AM, Wester AL, Ryrfors P, Holmstad R, Mohsin M, Hasan R, Shakoor S, Gustafson NW, Schill CH, Rojas MLZ, Velasquez JE, Magtibay BB, Catangcatang K, Sibulo R, Yauce FC, Wasyl D, Manaia C, Rocha J, Martins J, Álvaro P, Di Yoong Wen D, Shin H, Hur HG, Yoon S, Bosevska G, Kochubovski M, Cojocaru R, Burduniuc O, Hong PY, Perry MR, Gassama A, Radosavljevic V, Tay MYF, Zuniga-Montanez R, Wuertz S, Gavačová D, Pastuchová K, Truska P, Trkov M, Keddy K, Esterhuyse K, Song MJ, Quintela-Baluja M, Lopez MG, Cerdà-Cuéllar M, Perera RRDP, Bandara NKBKRGW, Premasiri HI, Pathirage S, Charlemagne K, Rutgersson C, Norrgren L, Örn S, Boss R, Van der Heijden T, Hong YP, Kumburu HH, Mdegela RH, Hounmanou YMG, Chonsin K, Suthienkul O, Thamlikitkul V, de Roda Husman AM, Bidjada B, Njanpop-Lafourcade BM, Nikiema-Pessinaba SC, Levent B, Kurekci C, Ejobi F, Kalule JB, Thomsen J, Obaidi O, Jassim LM, Moore A, Leonard A, Graham DW, Bunce JT, Zhang L, Gaze WH, Lefor B, Capone D, Sozzi E, Brown J, Meschke JS, Sobsey MD, Davis M, Beck NK, Sukapanpatharam P, Truong P, Lilienthal R, Kang S, Wittum TE, Rigamonti N, Baklayan P, Van CD, Tran DMN, Do Phuc N, Kwenda G, Larsson DGJ, Koopmans M, Woolhouse M, Aarestrup FM. Author Correction: Genomic analysis of sewage from 101 countries reveals global landscape of antimicrobial resistance. Nat Commun 2023; 14:178. [PMID: 36635285 PMCID: PMC9837105 DOI: 10.1038/s41467-023-35890-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Patrick Munk
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Christian Brinch
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Frederik Duus Møller
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Thomas N. Petersen
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Rene S. Hendriksen
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Anne Mette Seyfarth
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Jette S. Kjeldgaard
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Christina Aaby Svendsen
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Bram van Bunnik
- grid.4305.20000 0004 1936 7988Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, UK
| | - Fanny Berglund
- grid.8761.80000 0000 9919 9582Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | | | - D. G. Joakim Larsson
- grid.8761.80000 0000 9919 9582Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Marion Koopmans
- grid.5645.2000000040459992XDepartment of Viroscience, Erasmus MC, Rotterdam, The Netherlands
| | - Mark Woolhouse
- grid.4305.20000 0004 1936 7988Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, UK
| | - Frank M. Aarestrup
- grid.5170.30000 0001 2181 8870Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
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Yee A, Tsui NB, Chang YN, Au CS, Fok M, Lau LT, Chung T, Chung G, Kwan RY, Leung AY, Lau JY, Dai DL. Alzheimer's disease: insights for risk evaluation and prevention in the Chinese population and the need for a comprehensive programme in Hong Kong/China. Hong Kong Med J 2019; 24:492-500. [PMID: 30232267 DOI: 10.12809/hkmj187244] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
With the ageing of the global population, China is projected to be impacted significantly by the rising number of patients with Alzheimer's disease (AD). A cure for AD is not yet available, so society should be prepared for an increasing AD-related burden. In this review, we examine this impending problem and provide overviews on (a) the magnitude of the problem of AD in Hong Kong/China in the near future; (b) the genetic and lifestyle risk factors that contribute to AD; (c) current diagnostic approaches and the potential of newly discovered genetic biomarkers for early detection; (d) medications, non-pharmacological interventions, and possible preventive measures; and (e) the need for social and psychological care from the community. In Hong Kong, primary care and AD-related support for at-risk individuals, patients, and caregivers are inadequate. A joint effort from the medical community, government, universities, non-governmental organisations/charities, and industry should initiate the development of a long-term programme for AD. Finally, we outline recommendations for the relevant parties to consider.
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Affiliation(s)
- A Yee
- Avalon Genomics (HK) Limited, Shatin, Hong Kong
| | - N By Tsui
- Avalon Genomics (HK) Limited, Shatin, Hong Kong.,Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hunghom, Hong Kong
| | - Y N Chang
- Avalon Genomics (HK) Limited, Shatin, Hong Kong
| | - C Sm Au
- Yan Oi Tong Clarea Au Eldergarten, Kwun Tong, Hong Kong
| | - M Fok
- Avalon Genomics (HK) Limited, Shatin, Hong Kong.,Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hunghom, Hong Kong.,Faculty of Health Sciences, Macau University of Science and Technology, Macau
| | - L T Lau
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hunghom, Hong Kong
| | - T Chung
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hunghom, Hong Kong
| | - G Chung
- Faculty of Health Sciences, Macau University of Science and Technology, Macau
| | - R Yc Kwan
- Centre for Gerontological Nursing, School of Nursing, The Hong Kong Polytechnic University, Hunghom, Hong Kong
| | - A Ym Leung
- Centre for Gerontological Nursing, School of Nursing, The Hong Kong Polytechnic University, Hunghom, Hong Kong
| | - J Yn Lau
- Avalon Genomics (HK) Limited, Shatin, Hong Kong.,Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hunghom, Hong Kong
| | - D Lk Dai
- Hong Kong Alzheimer's Disease Association, Hong Kong
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Kwan RYC, Leung AYM, Yee A, Lau LT, Xu XY, Dai DLK. Cognitive Frailty and Its Association with Nutrition and Depression in Community-Dwelling Older People. J Nutr Health Aging 2019; 23:943-948. [PMID: 31781723 DOI: 10.1007/s12603-019-1258-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Cognitive frailty is a condition where physical frailty and mild cognitive impairment (MCI) co-exist. It is associated with increased risk of dementia and dependency. Previous studies reported that malnutrition and depression are associated with physical frailty and MCI; however, their relationships with cognitive frailty remained to be explored. The aims of this study were to examine the association of nutrition and depression with cognitive frailty, in comparison to having physical frailty or MCI alone. METHODS This study employed a cross-sectional design. Data collection was conducted in the community settings on the older people without dementia. Dependent variables were cognitive frailty, physical frailty, and MCI. The independent variables were depression and nutrition. Multi-nominal regression was employed to examine the relationships between the dependent and independent variables. The associations were adjusted by four known co-variates, including age, gender, education and APOE ε4 carrier status. RESULTS A total of 185 participants were recruited from four community centres and one elderly hostel and completed the data collection. Approximately 44.9% of the older people with physical frailty and 82.5% of elderly with MCI belonged to cognitive frailty. Multi-nominal regression models showed that depression is positively associated with cognitive frailty and with physical frailty, but not associated with solely MCI. Nutrition is negatively associated with cognitive frailty, but not associated with physical frailty or MCI alone. CONCLUSION Cognitive frailty is associated with malnutrition and depression. Therapeutic interventions managing depression and malnutrition may focus the older people with cognitive frailty to improve efficacy and cost-effectiveness.
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Affiliation(s)
- R Y C Kwan
- David L.K. Dai, Hong Kong Alzheimer's Disease Association, G/F, Wang Yip House, Wang Tau Hom Estate, Hong Kong Tel: (852) 2338 1120 Fax: (852) 23380772
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Tsui NBY, Cheng G, Chung T, Lam CWK, Yee A, Chung PKC, Kwan TK, Ko E, He D, Wong WT, Lau JYN, Lau LT, Fok M. Population-Wide Genetic Risk Prediction of Complex Diseases: A Pilot Feasibility Study in Macau Population for Precision Public Healthcare Planning. Sci Rep 2018; 8:1853. [PMID: 29382849 PMCID: PMC5789865 DOI: 10.1038/s41598-017-19017-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 12/20/2017] [Indexed: 02/01/2023] Open
Abstract
The genetic bases of many common diseases have been identified through genome-wide association studies in the past decade. However, the application of this approach on public healthcare planning has not been well established. Using Macau with population of around 650,000 as a basis, we conducted a pilot study to evaluate the feasibility of population genomic research and its potential on public health decisions. By performing genome-wide SNP genotyping of over a thousand Macau individuals, we evaluated the population genetic risk profiles of 47 non-communicable diseases and traits, as well as two traits associated with influenza infection. We found that for most of the diseases, the genetic risks of Macau population were different from those of Caucasian, but with similar profile with mainland Chinese. We also identified a panel of diseases that Macau population may have a high or elevated genetic risks. This pilot study showed that (1) population genomic study is feasible in Asian regions like Macau; (2) Macau may have different profile of population-based genetic risks than Caucasians, (3) the different prevalence of genetic risk profile indicates the importance of Asian-specific studies for Asian populations; and (4) the results generated may have an impact for going forward healthcare planning.
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Affiliation(s)
- Nancy B Y Tsui
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.,Avalon Genomics (Hong Kong) Limited, Shatin, Hong Kong
| | - Gregory Cheng
- Faculty of Health Sciences, Macau University of Science and Technology, Taipa, Macau
| | - Teresa Chung
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Christopher W K Lam
- Faculty of Health Sciences, Macau University of Science and Technology, Taipa, Macau
| | - Anita Yee
- Avalon Genomics (Hong Kong) Limited, Shatin, Hong Kong
| | | | - Tsz-Ki Kwan
- Avalon Genomics (Hong Kong) Limited, Shatin, Hong Kong
| | - Elaine Ko
- Avalon Genomics (Hong Kong) Limited, Shatin, Hong Kong
| | - Daihai He
- Department of Applied Mathematics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Wing-Tak Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Johnson Y N Lau
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Lok Ting Lau
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
| | - Manson Fok
- Faculty of Health Sciences, Macau University of Science and Technology, Taipa, Macau.
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Li C, Zhao R, Gao K, Wei Z, Yin MY, Lau LT, Chui D, Yu ACH. Astrocytes: implications for neuroinflammatory pathogenesis of Alzheimer's disease. Curr Alzheimer Res 2011; 8:67-80. [PMID: 21143158 DOI: 10.2174/156720511794604543] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 10/05/2010] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease with major clinical hallmarks of memory loss, dementia, and cognitive impairment. Neuroinflammation is involved in the onset of several neurodegenerative disorders. Astrocyte is the most abundant type of glial cells in the central nervous system (CNS) and appears to be involved in the induction of neuroinflammation. Under stress and injury, astrocytes become astrogliotic leading to an upregulation of the expression of proinflammatory cytokines and chemokines, which are associated with the pathogenesis of AD. Cytokines and related molecules play roles in both neuroprotection and neurodegeneration in the CNS. During early AD pathogenesis, amyloid beta (Aβ), S100B and IL-1β could bring about a vicious cycle of Aβ generation between astrocytes and neurons leading to chronic, sustained and progressive neuroinflammation. In advanced stages of AD, TRAIL secreted from astrocytes have been shown to bind to death receptor 5 (DR5) on neurons to trigger apoptosis in a caspase-8-dependent manner. Furthermore, astrocytes could be reactivated by TGFβ1 to generate more Aβ and to undergo the aggravating astrogliosis. TGFβ2 was also observed to cooperate with Aβ to cause neuronal demise by destroying the stability of lysosomes in neurons. Inflammatory molecules can be either potential biomarkers for diagnosis or target molecules for therapeutic intervention. Understanding their roles and their relationship with activated astrocytes is particularly important for attenuating neuroinflammation in the early stage of AD. The main purpose of this review is to provide a comprehensive insight into the role of astrocytes in the neuroinflammatory pathogenesis of AD.
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Affiliation(s)
- Chuanyu Li
- Beijing Hai Kang DNA Chips Limited, Beijing Economic Development Area, Yizhuang, China
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Yang CZ, Li HL, Zhou Y, Chai RC, Zhao R, Dong Y, Xu ZY, Lau LT, Yingge Z, Teng J, Chen J, Yu ACH. A new specialization in astrocytes: Glutamate- and ammonia-induced nuclear size changes. J Neurosci Res 2011; 89:2041-51. [DOI: 10.1002/jnr.22657] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 02/23/2011] [Accepted: 03/10/2011] [Indexed: 12/18/2022]
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Lau LT, Feng XY, Lam TY, Hui HK, Yu ACH. Development of multiplex nucleic acid sequence-based amplification for detection of human respiratory tract viruses. J Virol Methods 2010; 168:251-4. [DOI: 10.1016/j.jviromet.2010.04.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Revised: 04/20/2010] [Accepted: 04/27/2010] [Indexed: 11/25/2022]
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Dong Y, Liu HD, Zhao R, Yang CZ, Chen XQ, Wang XH, Lau LT, Chen J, Yu ACH. Ischemia activates JNK/c-Jun/AP-1 pathway to up-regulate 14-3-3γ in astrocyte. J Neurochem 2009; 109 Suppl 1:182-8. [DOI: 10.1111/j.1471-4159.2009.05974.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Xu ZY, Liu HD, Lau LT, Yingge Z, Zhao R, Tong GL, Chan PH, Yu ACH. Responses of astrocyte to simultaneous glutamate and arachidonic acid treatment. Neurochem Int 2009; 55:143-50. [DOI: 10.1016/j.neuint.2009.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/17/2009] [Accepted: 02/25/2009] [Indexed: 10/21/2022]
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Zhao Y, Lu M, Lau LT, Lu J, Gao Z, Liu J, Yu ACH, Cao Q, Ye J, McNutt MA, Gu J. Neutrophils may be a vehicle for viral replication and dissemination in human H5N1 avian influenza. Clin Infect Dis 2008; 47:1575-8. [PMID: 18990065 PMCID: PMC7107848 DOI: 10.1086/593196] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The mechanism of systemic spread of H5N1 virus in patients with avian influenza is unknown. Here, H5N1 nucleoprotein and hemagglutinin were identified by immunohistochemistry in the nucleus and cytoplasm of neutrophils in the placental blood of a pregnant woman. Viral RNA was detected in neutrophils by in situ hybridization and enhanced real-time polymerase chain reaction. Therefore, neutrophils may serve as a vehicle for viral replication and transportation in avian influenza.
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Affiliation(s)
- Yingying Zhao
- Department of Pathology, School of Basic Medical Sciences, Peking University, Beijing, China
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Yu ACH, Liu RY, Zhang Y, Sun HR, Qin LY, Lau LT, Wu BY, Hui HK, Heung MY, Han JS. Glial cell line-derived neurotrophic factor protects astrocytes from staurosporine- and ischemia- induced apoptosis. J Neurosci Res 2007; 85:3457-64. [PMID: 17497674 DOI: 10.1002/jnr.21345] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) promotes the survival and functions of neurons. It has been shown to be a promising candidate in the treatment of ischemia and other neurodegenerative diseases. We transfected mouse astrocytes in primary cultures with a human GDNF gene and found that their conditioned medium could not only support the growth and survival of cultured dopaminergic neurons but also protect astrocytes from staurosporine- and ischemia-induced apoptosis. This indicated that these transfected astrocytes could release GDNF. A similar protective effect on astrocytes against apoptosis was evident when recombinant human GDNF was used. Moreover, GDNF reduced caspase-3 activity but not that of caspase-1 in cultured astrocytes after ischemia treatment. Thus, GDNF protects astrocytes from apoptosis by inhibiting the activation of caspase-3.
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Gu J, Xie Z, Gao Z, Liu J, Korteweg C, Ye J, Lau LT, Lu J, Gao Z, Zhang B, McNutt MA, Lu M, Anderson VM, Gong E, Yu ACH, Lipkin WI. H5N1 infection of the respiratory tract and beyond: a molecular pathology study. Lancet 2007; 370:1137-45. [PMID: 17905166 PMCID: PMC7159293 DOI: 10.1016/s0140-6736(07)61515-3] [Citation(s) in RCA: 283] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
BACKGROUND Human infection with avian influenza H5N1 is an emerging infectious disease characterised by respiratory symptoms and a high fatality rate. Previous studies have shown that the human infection with avian influenza H5N1 could also target organs apart from the lungs. METHODS We studied post-mortem tissues of two adults (one man and one pregnant woman) infected with H5N1 influenza virus, and a fetus carried by the woman. In-situ hybridisation (with sense and antisense probes to haemagglutinin and nucleoprotein) and immunohistochemistry (with monoclonal antibodies to haemagglutinin and nucleoprotein) were done on selected tissues. Reverse-transcriptase (RT) PCR, real-time RT-PCR, strand-specific RT-PCR, and nucleic acid sequence-based amplification (NASBA) detection assays were also undertaken to detect viral RNA in organ tissue samples. FINDINGS We detected viral genomic sequences and antigens in type II epithelial cells of the lungs, ciliated and non-ciliated epithelial cells of the trachea, T cells of the lymph node, neurons of the brain, and Hofbauer cells and cytotrophoblasts of the placenta. Viral genomic sequences (but no viral antigens) were detected in the intestinal mucosa. In the fetus, we found viral sequences and antigens in the lungs, circulating mononuclear cells, and macrophages of the liver. The presence of viral sequences in the organs and the fetus was also confirmed by RT-PCR, strand-specific RT-PCR, real-time RT-PCR, and NASBA. INTERPRETATION In addition to the lungs, H5N1 influenza virus infects the trachea and disseminates to other organs including the brain. The virus could also be transmitted from mother to fetus across the placenta.
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Affiliation(s)
- Jiang Gu
- Infectious Disease Centre, Peking University, Beijing, China.
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Yu ACH, Sun CX, Li Q, Liu HD, Wang CR, Zhao GP, Jin M, Lau LT, Fung YWW, Liu S. Identification of a mouse synaptic glycoprotein gene in cultured neurons. Neurochem Res 2006; 30:1289-94. [PMID: 16341590 DOI: 10.1007/s11064-005-8800-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2005] [Indexed: 12/19/2022]
Abstract
Neuronal differentiation and aging are known to involve many genes, which may also be differentially expressed during these developmental processes. From primary cultured cerebral cortical neurons, we have previously identified various differentially expressed gene transcripts from cultured cortical neurons using the technique of arbitrarily primed PCR (RAP-PCR). Among these transcripts, clone 0-2 was found to have high homology to rat and human synaptic glycoprotein. By in silico analysis using an EST database and the FACTURA software, the full-length sequence of 0-2 was assembled and the clone was named as mouse synaptic glycoprotein homolog 2 (mSC2). DNA sequencing revealed transcript size of mSC2 being smaller than the human and rat homologs. RT-PCR indicated that mSC2 was expressed differentially at various culture days. The mSC2 gene was located in various tissues with higher expression in brain, lung, and liver. Functions of mSC2 in neurons and other tissues remain elusive and will require more investigation.
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Cui SJ, Fung YWW, Lau LT, Liu WB, Wang YF, Tong GZ, Chen J, Yu ACH. Detection of Newcastle disease virus using nucleic acid sequence-based amplification. Biologicals 2006; 35:13-8. [PMID: 16500117 DOI: 10.1016/j.biologicals.2005.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 11/10/2005] [Accepted: 12/01/2005] [Indexed: 11/21/2022] Open
Abstract
Newcastle disease (ND) is a contagious and widespread avian disease affecting most species of birds. ND virus (NDV) is the only member of the avian paramyxovirus serotype 1 (APMV1) causing ND outbreak in bird flocks. The technique of nucleic acid sequence-based amplification (NASBA) is a potential method to rapidly and reliably detect NDV isolates. Here, we describe an effective and unprecedented method for detecting NDV strains of all pathotypes. A conserved region of the fusion protein gene was used for designing oligonucleotides specific to all NDV pathotypes. The dynamic range of this NDV NASBA detection method is comparable to virus culture and therefore the NDV NASBA method is a potential alternative for NDV screening and surveillance.
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Affiliation(s)
- Shang-Jin Cui
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, CAAS, No. 427 Maduan Street, Harbin 150001, China
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15
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Li HL, Li Z, Qin LY, Liu S, Lau LT, Han JS, Yu ACH. The novel neurotrophin-regulated neuronal development-associated protein, NDAP, mediates apoptosis. FEBS Lett 2006; 580:1723-8. [PMID: 16516892 DOI: 10.1016/j.febslet.2006.02.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Revised: 02/03/2006] [Accepted: 02/10/2006] [Indexed: 11/22/2022]
Abstract
We identified a novel gene and named it, "neuronal development-associated protein (NDAP)". We detected NDAP mRNA presence in most tissues including the brain where it was present in the area from the external granular layer to the multiform layer in the cerebral cortex, and in CA1, CA2, CA3 and the dentate gyrus in the hippocampus. Its expression increased transiently in primary cultures of 2-4 day neurons and 1-2 week astrocytes and was significantly reduced in older cultures. Treatment by the neurotrophin, NT-3, significantly attenuated the decline of NDAP in neurons from days 2 to 10, whereas growth factors such as GDNF and insulin, and high potassium levels did not. To elucidate the effects of neurotrophins, we treated day 5 neurons with NT-3, BDNF or NGF for 48 h. NT-3 and BDNF both inhibited downregulation of NDAP mRNA levels but NGF slightly enhanced the already present downregulation; this effect of NGF was significant when examined in day 3 neurons. To investigate the potential function of NDAP, we over-expressed an NDAP-EGFP fusion protein in 4-week-old astrocytes. The newly expressed NDAP gradually aggregated into membrane-bound structures and eventually led to cell death through apoptosis by 24 h. Significant levels of cell death were also observed in NDAP-EGFP transfected HEK293 cells. Thus maintenance of high NDAP levels may cause apoptosis. The different regulations of NDAP expression by neurotrophins indicate that the expression of NDAP might be a checkpoint for apoptosis during neuronal development.
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Affiliation(s)
- Hui Li Li
- Neuroscience Research Institute, Peking University, Key Laboratory of Neuroscience (PKU), Ministry of Education and Department of Neurobiology, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100083, China
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16
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Lau LT, Fung YWW, Yu ACH. Detection of animal viruses using nucleic acid sequence-based amplification (NASBA). Dev Biol (Basel) 2006; 126:7-15; discussion 323. [PMID: 17058476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
As seen in recent avian influenza outbreaks in Asia, prevention is the key to fighting infectious disease successfully. Efficient disease surveillance systems on the basis of molecular diagnostics will help monitor the emergence of viruses in the early stage and thus prompt containment measures can be in place to minimize disease spread. Here we describe and review molecular diagnostics focusing on nucleic acid sequence-based amplification (NASBA) technology in detecting viruses causing animal diseases, such as avian influenza, foot-and-mouth disease, and Newcastle disease. NASBA offers high sensitivity, specificity, accuracy, and speed of availability of results, and NASBA would be the most applicable molecular diagnostics for disease surveillance and control.
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Affiliation(s)
- L T Lau
- Hong Kong DNA Chips Ltd, Hang Tung Resources Centre, Shau Kei Wan, China
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17
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Abstract
Retinal neurodegenerative disease involves an inflammatory response in the retina characterized by an increase in inflammatory cytokines and activation of microglia. The degree of microglia activation may influence the extent of retinal injury following an inflammatory stimulus. Cytokines released by activated microglia regulate the influx of inflammatory cells to the damaged area. Thus, a therapeutic strategy to reduce cytokine expression in microglia would be neuroprotective. Minocycline, a semisynthetic tetracycline derivative, is known to protect rodent brain from ischemia and to inhibit microglial activation. In this study, we activated retinal microglia in culture with lipopolysaccharide (LPS) and attempted to determine whether minocycline could reduce the production of cytokines from activated microglia at both gene and protein levels. Changes in inflammatory cytokines, TNF-alpha and IL-1beta, were measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) in the presence or absence of LPS. We also measured the levels of nitric oxide (NO) by the nitrate reductase method under similar conditions. LPS treatment induced a significant upregulation of the mRNA and release of TNF-alpha, IL-1beta, and NO from retinal microglia. Minocycline inhibited these releases. Thus, minocycline might exert its antiinflammatory effect on microglia by inhibiting the expression and release of TNF-alpha, IL-1beta, and NO.
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Affiliation(s)
- Ai Ling Wang
- Peking University Eye Center, Peking University Third Hospital, Peking University, Beijing 100083, China.
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18
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Abstract
Neuroglobin (Ngb), a recently discovered intracellular respiratory globin in neurons, may play a crucial role in oxygen homeostasis in the brain. We report preliminary findings indicating the presence of functional neuroglobin in primary cultures of cerebral cortical astrocytes. Reverse transcription real-time polymerase chain reaction (RRT-PCR) and immunostaining confirmed such presence in cultured astrocytes isolated from newborn mouse brain. Ngb antisense treatment increased apoptosis in ischemic astrocytes. The discovery of Ngb in astrocytes may provide some insight into how oxygen homeostasis is regulated in the brain.
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Affiliation(s)
- Xiao Qian Chen
- Neuroscience Research Institute, Peking University, Key Laboratory of Neuroscience, Ministry of Education, Department of Neurobiology, Peking University Health Science Center, Beijing, People's Republic of China
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19
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Chen XQ, Lau LT, Fung YWW, Yu ACH. Inactivation of bad by site-specific phosphorylation: The checkpoint for ischemic astrocytes to initiate or resist apoptosis. J Neurosci Res 2005; 79:798-808. [PMID: 15672442 DOI: 10.1002/jnr.20396] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Bcl-2-associated death protein (Bad), a member of the Bcl family, directs astrocytes in primary cultures to enter or resist apoptosis during ischemia in vitro. Under ischemia, Bad was the only Bcl family member whose expression was upregulated significantly during the early stages of an ischemic insult. Increased endogenous Bad was translocated from the cytoplasm to mitochondria to induce apoptosis in astrocytes. Concurrently, ischemia also induced Bad phosphorylation specifically on Ser112 to promote survival. This site-specific phosphorylation of Bad was mediated by an early activation of the mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/ERK) intracellular signaling pathway. This study demonstrates that ischemia-induced Bad plays a dual role in determining whether astrocytes enter or resist apoptosis after an ischemic insult.
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Affiliation(s)
- Xiao Qian Chen
- Neuroscience Research Institute, Peking University, Beijing, China
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20
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Abstract
Astrogliosis is an inevitable and rapid response of astrocytes to physical, chemical and pathological injuries. To study astrogliosis, we developed a reproducible in vitro model in which low temperature injury to cultured astrocytes could be induced by placing the culture dish onto a copper pipe pre-cooled by liquid nitrogen. Using this model, the relationship between the temperature decline and the severity of cellular damage was analyzed. An increase in the expression of some known injury-related proteins, such as glial fibrillary acidic protein (GFAP), immediate early response genes (IEGs), and heat shock proteins 70 (HSP70), was demonstrated in astrocytes after low temperature trauma. With the use of this low temperature trauma model, the flexibility in the temperature control and injury area may allow researchers to evaluate cryotherapy and cryosurgery, which could be applicable to future development of quality health care.
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Affiliation(s)
- Albert Cheung Hoi Yu
- Key Laboratory of Neuroscience, Neuroscience Research Institute, Peking University, Beijing, China.
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21
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Fung YWW, Lau LT, Wong FPF, Choi KW, Chau TN, Lai ST, Wang CG, Dillon N, Yu ACH. Use of Clinical Criteria and Molecular Diagnosis to More Effectively Monitor Patients Recovering after Severe Acute Respiratory Syndrome Coronavirus Infection. Clin Infect Dis 2004; 39:604-6. [PMID: 15356838 PMCID: PMC7204107 DOI: 10.1086/422887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Yin-Wan Wendy Fung
- Neuroscience Research Institute, Key Laboratory of Neuroscience, Peking University and Department of Neurobiology, Peking University Health Science Center, Ministry of Education, Beijing
- Hong Kong DNA Chips, Hong Kong Special Administrative Region, China
| | - Lok Ting Lau
- Neuroscience Research Institute, Key Laboratory of Neuroscience, Peking University and Department of Neurobiology, Peking University Health Science Center, Ministry of Education, Beijing
- Hong Kong DNA Chips, Hong Kong Special Administrative Region, China
| | | | - Kin-Wing Choi
- Princess Margaret Hospital, Kowloon, Hong Kong Special Administrative Region, China
| | - Tai-Nin Chau
- Princess Margaret Hospital, Kowloon, Hong Kong Special Administrative Region, China
| | - Sik-To Lai
- Princess Margaret Hospital, Kowloon, Hong Kong Special Administrative Region, China
| | - Chen G Wang
- National Emergency Action on SARS Research (Beijing Group), Beijing
| | - Natalie Dillon
- Hong Kong DNA Chips, Hong Kong Special Administrative Region, China
| | - Albert Cheung-Hoi Yu
- Neuroscience Research Institute, Key Laboratory of Neuroscience, Peking University and Department of Neurobiology, Peking University Health Science Center, Ministry of Education, Beijing
- National Emergency Action on SARS Research (Beijing Group), Beijing
- Hong Kong DNA Chips, Hong Kong Special Administrative Region, China
- Reprints or correspondence: Dr. Albert Cheung-Hoi Yu, Neuroscience Research Institute, Key Laboratory of Neuroscience, Peking University and Dept. of Neurobiology, Peking University Health Science Ctr., Ministry of Education, 38 Xue Yuan Rd., Beijing 100083, China ()
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22
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Lau LT, Fung YWW, Wong FPF, Lin SSW, Wang CR, Li HL, Dillon N, Collins RA, Tam JSL, Chan PK, Wang CG, Yu ACH. A real-time PCR for SARS-coronavirus incorporating target gene pre-amplification. Biochem Biophys Res Commun 2004; 312:1290-6. [PMID: 14652014 PMCID: PMC7111096 DOI: 10.1016/j.bbrc.2003.11.064] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An enhanced polymerase chain reaction (PCR) assay to detect the coronavirus associated with severe acute respiratory syndrome (SARS-CoV) was developed in which a target gene pre-amplification step preceded TaqMan real-time fluorescent PCR. Clinical samples were collected from 120 patients diagnosed as suspected or probable SARS cases and analyzed by conventional PCR followed by agarose gel electrophoresis, conventional TaqMan real-time PCR, and our enhanced TaqMan real-time PCR assays. An amplicon of the size expected from SARS-CoV was obtained from 28/120 samples using the enhanced real-time PCR method. Conventional PCR and real-time PCR alone identified fewer SARS-CoV positive cases. Results were confirmed by viral culture in 3/28 cases. The limit of detection of the enhanced real-time PCR method was 10(2)-fold higher than the standard real-time PCR assay and 10(7)-fold higher than conventional PCR methods. The increased sensitivity of the assay may help control the spread of the disease during future SARS outbreaks.
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Affiliation(s)
- Lok Ting Lau
- Key Laboratory of Neuroscience, Neuroscience Research Institute, Peking University and Department of Neurobiology, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100083, China
- Hong Kong DNA Chips Ltd, 1/F, Cosmos Centre, 108 Soy Street, Kowloon, Hong Kong SAR, China
| | - Yin-Wan Wendy Fung
- Hong Kong DNA Chips Ltd, 1/F, Cosmos Centre, 108 Soy Street, Kowloon, Hong Kong SAR, China
| | - Freda Pui-Fan Wong
- Hong Kong DNA Chips Ltd, 1/F, Cosmos Centre, 108 Soy Street, Kowloon, Hong Kong SAR, China
| | - Selma Sau-Wah Lin
- Hong Kong DNA Chips Ltd, 1/F, Cosmos Centre, 108 Soy Street, Kowloon, Hong Kong SAR, China
| | - Chen Ran Wang
- Key Laboratory of Neuroscience, Neuroscience Research Institute, Peking University and Department of Neurobiology, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100083, China
| | - Hui Li Li
- Key Laboratory of Neuroscience, Neuroscience Research Institute, Peking University and Department of Neurobiology, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100083, China
| | - Natalie Dillon
- Hong Kong DNA Chips Ltd, 1/F, Cosmos Centre, 108 Soy Street, Kowloon, Hong Kong SAR, China
| | - Richard A Collins
- Hong Kong DNA Chips Ltd, 1/F, Cosmos Centre, 108 Soy Street, Kowloon, Hong Kong SAR, China
| | - John Siu-Lun Tam
- Department of Microbiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Paul K.S Chan
- Department of Microbiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chen G Wang
- National Emergency Action on SARS Research (Beijing Group), Beijing, China
| | - Albert Cheung-Hoi Yu
- Key Laboratory of Neuroscience, Neuroscience Research Institute, Peking University and Department of Neurobiology, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100083, China
- Hong Kong DNA Chips Ltd, 1/F, Cosmos Centre, 108 Soy Street, Kowloon, Hong Kong SAR, China
- National Emergency Action on SARS Research (Beijing Group), Beijing, China
- Corresponding author. Fax: +852-2111-9762
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23
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Yu ACH, Yung HW, Hui MHK, Lau LT, Chen XQ, Collins RA. Cycloheximide and actinomycin D delay death and affect bcl-2, bax, and Ice gene expression in astrocytes under in vitro ischemia. J Neurosci Res 2003; 74:318-25. [PMID: 14515361 DOI: 10.1002/jnr.10742] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
An in vitro ischemia model was established and the effect of the metabolic inhibitors cycloheximide (CHX) and actinomycin D (ActD) on apoptosis in astrocytes under ischemia studied. CHX decreased by 75% the number of cells dying after 6 hr of ischemia compared with control cultures. TdT-mediated dUTP nick end labelling (TUNEL) staining of comparable cultures was reduced by 40%. ActD decreased cell death by 60% compared with controls. The number of TUNEL-positive cells was reduced by 38%. The nuclear shrinkage in TUNEL-positive astrocytes in control cultures did not occur in ActD-treated astrocytes, indicating that nuclear shrinkage and DNA fragmentation during apoptosis are two unrelated processes. Expression of bcl-2 (alpha and beta), bax, and Ice in astrocytes under similar ischemic conditions, as measured by quantitative reverse transcription-polymerase chain reaction, indicated that ischemia down-regulated bcl-2 (alpha and beta) and bax. Ice was initially down-regulated from 0 to 4 hr, before returning to control levels after 8 hr of ischemia. ActD decreased the expression of these genes. CHX reduced the expression of bcl-2 (alpha and beta) but increased bax and Ice expression. It is hypothesized that the balance of proapoptotic (Bad, Bax) and antiapoptotic (Bcl-2, Bcl-Xl) proteins determines apoptosis. The data suggest that the ratio of Bcl-2/Bad in astrocytes following ActD and CHX treatment does not decrease as much in untreated cells during ischemia. Our data indicate that it is the ratio of Bcl-2 family members that plays a critical role in determining ischemia-induced apoptosis. It is also important to note that ischemia-induced apoptosis involves the regulation of RNA and protein synthesis.
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Affiliation(s)
- Albert Cheung Hoi Yu
- Neuroscience Research Institute, Peking University and Department of Neurobiology, Peking University Health Science Center, Beijing, People's Republic of China.
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24
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Abstract
Nucleic acid sequence-based amplification (NASBA) allows the rapid amplification of specific regions of nucleic acid obtained from a diverse range of sources. It is especially suitable for amplifying RNA sequences. A NASBA technique was developed that allows the detection of avian influenza A subtype H5 from allantoic fluid harvested from inoculated chick embryos. The amplified viral RNA is detected by electrochemiluminescence. The described NASBA technique is a specific, rapid, and sensitive method of detection of influenza A subtype H5 viruses. More importantly, it can be used to distinguish high- and low-pathogenicity strains of the H5 subtype.
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Affiliation(s)
- R A Collins
- Hong Kong DNA Chips Ltd., 1805-6, 18F, Lu Plaza, 2 Wing Yip Street, Kowloon, Hong Kong SAR, China
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25
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Abstract
A very large body of evidence from in vivo studies has been accumulated on a link between the change of energy and cell survival/apoptosis. Using an in vitro ischemia model, we have previously shown that ischemia could induce apoptosis in astrocytes. In this study, we utilized the same in vitro model to investigate changes in ATP and ADP levels in cultured astrocytes and attempted to demonstrate an energy-cell death linkage. Astrocytes remained unaltered after 2 hr of ischemia but were moderately or severely damaged after 4 or 6-8 hr, respectively. The astrocytes that survived various lengths of in vitro ischemic incubation retained their ability to produce ATP after ischemia. Both ATP and ADP levels were increased in astrocytes that remained alive under in vitro ischemia for over 6 hr. The largest decline in the percent of viable astrocytes during ischemia corresponded well to the reduction in ATP and ADP levels in these cultures.
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Affiliation(s)
- Albert Cheung Hoi Yu
- Neuroscience Research Institute and Department of Neurobiology, Peking University, Beijing, China.
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26
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Collins RA, Ko LS, So KL, Ellis T, Lau LT, Yu ACH. Detection of highly pathogenic and low pathogenic avian influenza subtype H5 (Eurasian lineage) using NASBA. J Virol Methods 2002; 103:213-25. [PMID: 12008015 DOI: 10.1016/s0166-0934(02)00034-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nucleic acid sequence-based amplification (NASBA) is a technique that allows the rapid amplification of specific regions of nucleic acid obtained from a diverse range of sources. It is especially suitable for amplifying RNA sequences. A NASBA technique has been developed that allows the detection of avian influenza A subtype H5 from allantoic fluid harvested from inoculated chick embryos. The amplified viral RNA is detected by electrochemiluminescence. The NASBA technique described below is rapid and specific for the identification of influenza A subtype H5 viruses of the Eurasian lineage. More importantly, it can be used to distinguish highly pathogenic and low pathogenic strains of the H5 subtype.
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Affiliation(s)
- Richard A Collins
- Hong Kong DNA Chips Ltd, 1805-6, 18/F, Lu Plaza, 2 Wing Yip Street, Hong Kong SAR, Kowloon, China
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27
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Abstract
Astrocytes participate in a wide variety of important physiological processes and pathological insults, including ischemia. Information on the mechanism of astroglial injury and death during ischemic insult, however, is scarce. In this study, we investigated the mode of astrocytic cell death using an in vitro ischemic model. Cultured astrocytes exhibited several distinct morphological and biochemical features of apoptosis under ischemia. At 4 h of ischemia, Annexin V staining demonstrated an early commitment of some astrocytes to apoptosis. Condensed nuclei became visible from 4 h and the number increased with ischemic incubation time. Electron microscopy showed compacted and segregated chromatin along the edges of nuclear membranes. The number of TUNEL-positive nuclei and the degree of DNA laddering increased with ischemic incubation. Caspase-3, but not caspase-1, activity was increased in ischemia-injured astrocytes. Swollen mitochondria and vacuoles found in some cells with chromatin condensation indicated that these apoptotic-like cells might die of necrosis. The results imply that astrocytes are capable of undergoing apoptosis without the presence of other cell types, such as neurons. Ischemia can induce apoptosis in astrocytes contributing to the pathogenesis of ischemic injury in the CNS.
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Affiliation(s)
- A C Yu
- Neuroscience Research Institute, Peking University, Beijing, China.
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28
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Lau LT, Yu AC. Astrocytes produce and release interleukin-1, interleukin-6, tumor necrosis factor alpha and interferon-gamma following traumatic and metabolic injury. J Neurotrauma 2001; 18:351-9. [PMID: 11284554 DOI: 10.1089/08977150151071035] [Citation(s) in RCA: 232] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The brain is no longer considered immune-privileged due to its capability of producing cytokines in response to neurotrauma; however, the cellular sources of cytokines have not been defined. This study focused on the production of four inflammatory cytokines, interleukin-1 (IL-1alpha), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha), and interferon gamma (IFN-gamma) in primary culture of astrocytes under two different injury models which simulated in vivo mechanical trauma (scratch injury) and ischemia. Results demonstrated that astrocytes after scratch injury were positively immunostained with IL-1alpha, IL-6, and TNFalpha. A slot-blot study of culture media showed that the release of IL-1alpha, IL-6, TNFalpha, and IFN-gamma by astrocytes subsequent to scratch and ischemic injury reached approximately twice the control values. The temporal expression of these cytokines was different for the two models. All four cytokines began to increase 1 h postscratch and remained at high levels throughout the experiment. In the ischemic model, however, the increase of cytokine expression was delayed until 4-8 h of ischemia, when sharp increases were seen in all four cytokines. In this culture system, the exogenous influence of blood-borne factors and leukocytes, which occur with in vivo trauma and ischemia, was eliminated. Accordingly, the cytokines detected in the culture media were derived from astrocytes. This study provides the first evidence that astrocytes, without the influence from other cell types, can produce and release cytokines following mechanical and ischemic injury.
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Affiliation(s)
- L T Lau
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, China
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29
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Abstract
Astrocytes form an integral part of the blood brain barrier and are the first cell type in the central nervous system to encounter insult if there is an ischemic attack. The immunologic reaction of astrocytes to an ischemic insult would be affective to the subsequent responses of other nerve cells. We previously showed that ischemia caused an increase in the levels of interleukin 1alpha (IL-1alpha), tumor necrosis factor alpha (TNF alpha), and interleukin 6 (IL-6) in the culture medium of mouse cerebral cortical astrocyte. We did not have evidence on the source of these cytokines. This study aimed to investigate the expressions of these cytokine mRNAs in the astrocytes under ischemia. Results demonstrated that ischemia could induce necrosis and apoptosis in astrocytes. By using the RT-PCR method, we demonstrated for the first time that the mRNA levels of IL-1alpha, TNF alpha and IL-6 in normal astrocyte was very low, but their expressions could be induced quickly under ischemia. These cytokines might be interactive as indicated by the difference in time course of their expressions, with IL-1alpha being the earliest and IL-6 being the latest. The result provided some understanding of the induction and progression of these immunologic responses in astrocytes under ischemia. It also supported our previous findings that astrocytes contributed to the cytokines released under ischemia.
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Affiliation(s)
- A C Yu
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon.
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