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Sahu B, Nookala S, Floden AM, Ambhore NS, Sathish V, Klug MG, Combs CK. House dust mite-induced asthma exacerbates Alzheimer's disease changes in the brain of the App NL-G-F mouse model of disease. Brain Behav Immun 2024; 121:365-383. [PMID: 39084541 DOI: 10.1016/j.bbi.2024.07.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 07/19/2024] [Accepted: 07/28/2024] [Indexed: 08/02/2024] Open
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) plaques, neuroinflammation, and neuronal death. Besides aging, various comorbidities increase the risk of AD, including obesity, diabetes, and allergic asthma. Epidemiological studies have reported a 2.17-fold higher risk of dementia in asthmatic patients. However, the molecular mechanism(s) underlying this asthma-associated AD exacerbation is unknown. This study was designed to explore house dust mite (HDM)-induced asthma effects on AD-related brain changes using the AppNL-G-F transgenic mouse model of disease. Male and female 8-9 months old C57BL/6J wild type and AppNL-G-F mice were exposed to no treatment, saline sham, or HDM extract every alternate day for 16 weeks for comparison across genotypes and treatment. Mice were euthanized at the end of the experiment, and broncho-alveolar lavage fluid (BALF), blood, lungs, and brains were collected. BALF was used to quantify immune cell phenotype, cytokine levels, total protein content, lactate dehydrogenase (LDH) activity, and total IgE. Lungs were sectioned and stained with hematoxylin and eosin, Alcian blue, and Masson's trichrome. Serum levels of cytokines and soluble Aβ1-40/42 were quantified. Brains were sectioned and immunostained for Aβ, GFAP, CD68, and collagen IV. Finally, frozen hippocampi and temporal cortices were used to perform Aβ ELISAs and cytokine arrays, respectively. HDM exposure led to increased levels of inflammatory cells, cytokines, total protein content, LDH activity, and total IgE in the BALF, as well as increased pulmonary mucus and collagen staining in both sexes and genotypes. Levels of serum cytokines increased in all HDM-exposed groups. Serum from the AppNL-G-F HDM-induced asthma group also had significantly increased soluble Aβ1-42 levels in both sexes. In agreement with this peripheral change, hippocampi from asthma-induced male and female AppNL-G-F mice demonstrated elevated Aβ plaque load and increased soluble Aβ 1-40/42 and insoluble Aβ 1-40 levels. HDM exposure also increased astrogliosis and microgliosis in both sexes of AppNL-G-F mice, as indicated by GFAP and CD68 immunoreactivity, respectively. Additionally, HDM exposure elevated cortical levels of several cytokines in both sexes and genotypes. Finally, HDM-exposed groups also showed a disturbed blood-brain-barrier (BBB) integrity in the hippocampus of AppNL-G-F mice, as indicated by decreased collagen IV immunoreactivity. HDM exposure was responsible for an asthma-like condition in the lungs that exacerbated Aβ pathology, astrogliosis, microgliosis, and cytokine changes in the brains of male and female AppNL-G-F mice that correlated with reduced BBB integrity. Defining mechanisms of asthma effects on the brain may identify novel therapeutic targets for asthma and AD.
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Affiliation(s)
- Bijayani Sahu
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA
| | - Suba Nookala
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA
| | - Angela M Floden
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA
| | - Nilesh S Ambhore
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health and Human Sciences, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health and Human Sciences, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Marilyn G Klug
- Department of Population health, School of Medicine and Health Sciences, USA
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA.
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Kurkinen M, Fułek M, Fułek K, Beszłej JA, Kurpas D, Leszek J. The Amyloid Cascade Hypothesis in Alzheimer’s Disease: Should We Change Our Thinking? Biomolecules 2023; 13:biom13030453. [PMID: 36979388 PMCID: PMC10046826 DOI: 10.3390/biom13030453] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/15/2023] [Accepted: 02/18/2023] [Indexed: 03/05/2023] Open
Abstract
Old age increases the risk of Alzheimer’s disease (AD), the most common neurodegenerative disease, a devastating disorder of the human mind and the leading cause of dementia. Worldwide, 50 million people have the disease, and it is estimated that there will be 150 million by 2050. Today, healthcare for AD patients consumes 1% of the global economy. According to the amyloid cascade hypothesis, AD begins in the brain by accumulating and aggregating Aβ peptides and forming β-amyloid fibrils (Aβ42). However, in clinical trials, reducing Aβ peptide production and amyloid formation in the brain did not slow cognitive decline or improve daily life in AD patients. Prevention studies in cognitively unimpaired people at high risk or genetically destined to develop AD also have not slowed cognitive decline. These observations argue against the amyloid hypothesis of AD etiology, its development, and disease mechanisms. Here, we look at other avenues in the research of AD, such as the presenilin hypothesis, synaptic glutamate signaling, and the role of astrocytes and the glutamate transporter EAAT2 in the development of AD.
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Affiliation(s)
| | - Michał Fułek
- Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology, Wroclaw Medical University, 50-556 Wroclaw, Poland
| | - Katarzyna Fułek
- Department and Clinic of Otolaryngology, Head and Neck Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland
- Correspondence: (K.F.); (J.L.)
| | | | - Donata Kurpas
- Department of Family Medicine, Wroclaw Medical University, 51-141 Wroclaw, Poland
| | - Jerzy Leszek
- Department and Clinic of Psychiatry, Wroclaw Medical University, 50-367 Wroclaw, Poland
- Correspondence: (K.F.); (J.L.)
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3
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Dai L, Shen Y. Insights into T-cell dysfunction in Alzheimer's disease. Aging Cell 2021; 20:e13511. [PMID: 34725916 PMCID: PMC8672785 DOI: 10.1111/acel.13511] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/22/2021] [Accepted: 10/22/2021] [Indexed: 12/11/2022] Open
Abstract
T cells, the critical immune cells of the adaptive immune system, are often dysfunctional in Alzheimer's disease (AD) and are involved in AD pathology. Reports highlight neuroinflammation as a crucial modulator of AD pathogenesis, and aberrant T cells indirectly contribute to neuroinflammation by secreting proinflammatory mediators via direct crosstalk with glial cells infiltrating the brain. However, the mechanisms underlying T‐cell abnormalities in AD appear multifactorial. Risk factors for AD and pathological hallmarks of AD have been tightly linked with immune responses, implying the potential regulatory effects of these factors on T cells. In this review, we discuss how the risk factors for AD, particularly Apolipoprotein E (ApoE), Aβ, α‐secretase, β‐secretase, γ‐secretase, Tau, and neuroinflammation, modulate T‐cell activation and the association between T cells and pathological AD hallmarks. Understanding these associations is critical to provide a comprehensive view of appropriate therapeutic strategies for AD.
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Affiliation(s)
- Linbin Dai
- Institute on Aging and Brain Disorders The First Affiliated Hospital of USTC Division of Life Sciences and Medicine University of Sciences and Technology of China Hefei China
- Neurodegenerative Disease Research Center University of Science and Technology of China Hefei China
- Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei China
| | - Yong Shen
- Institute on Aging and Brain Disorders The First Affiliated Hospital of USTC Division of Life Sciences and Medicine University of Sciences and Technology of China Hefei China
- Neurodegenerative Disease Research Center University of Science and Technology of China Hefei China
- Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei China
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Zhang J, Yang Y, Yang X, Qin J, Wei X, Peng Y, Li Z, Zhang L, Zhang Z, Zou Y. Influence of manganese exposure on cognitive function, plasma APP and Aβ levels in older men. J Trace Elem Med Biol 2021; 67:126788. [PMID: 34015662 DOI: 10.1016/j.jtemb.2021.126788] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 04/20/2021] [Accepted: 05/10/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Elevated manganese (Mn) exposure impairs cognition in adults and children, but the association between Mn and cognitive function in elderly people is unclear. Previous studies have linked Mn neurotoxicity in AD to Aβ-dependent mechanisms. However, the association between Mn and plasma APP and Aβ in the general elderly population remains unknown. This study aimed to investigate the association between Mn exposure and cognitive function, plasma APP and plasma Aβ in older adults. METHODS Cognitive abilities in 375 men aged 60 and older in Guangxi, China were assessed using the Mini-Mental State Examination (MMSE) and cognitive impairment were identified using education-stratified cut-off points of MMSE scores. Urinary Mn levels and plasma APP, and Aβ levels were measured using ICP-MS and ELISA, respectively. RESULTS A total of 109 (29.07 %) older men were identified as having cognitive impairment. The median urinary Mn level was 0.22 μg/g creatinine. Urinary Mn levels were negatively correlated with MMSE scores (β = -1.35, 95 % CI: -2.65 to -0.06; p = 0.041). In addition, higher concentrations of urinary manganese were associated with a greater risk of cognitive impairment (OR = 2.03, 95 % CI: 1.14-3.59; comparing the highest and lowest manganese; p = 0.025). Moreover, plasma APP levels were inversely associated with urinary Mn levels (r = -0.123, p = 0.020), and positively associated with MMSE scores (r = 0.158, p = 0.002). Surprisingly, no correlations were observed between plasma Aβ42, Aβ40, Aβ40/Aβ42, or Aβ42/Aβ40 and urinary Mn levels and MMSE scores. CONCLUSION These results suggested that Mn exposure is negatively associated with older men's cognition and plasma APP levels, but not plasma Aβ levels.
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Affiliation(s)
- Jie Zhang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Yiping Yang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Xiaobo Yang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Jian Qin
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Xiao Wei
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Yang Peng
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Zhiying Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Li'e Zhang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Zhiyong Zhang
- Department of Environmental Health and Occupational Medicine, School of Public Health, Guilin Medical University, Guilin, 541100, Guangxi, China.
| | - Yunfeng Zou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, Guangxi, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, Guangxi, China.
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Gosztyla ML, Brothers HM, Robinson SR. Alzheimer's Amyloid-β is an Antimicrobial Peptide: A Review of the Evidence. J Alzheimers Dis 2019; 62:1495-1506. [PMID: 29504537 DOI: 10.3233/jad-171133] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The amyloid-β (Aβ) peptide has long been considered to be the driving force behind Alzheimer's disease (AD). However, clinical trials that have successfully reduced Aβ burden in the brain have not slowed the cognitive decline, and in some instances, have resulted in adverse outcomes. While these results can be interpreted in different ways, a more nuanced picture of Aβ is emerging that takes into account the facts that the peptide is evolutionarily conserved and is present throughout life in cognitively normal individuals. Recent evidence indicates a role for Aβ as an antimicrobial peptide (AMP), a class of innate immune defense molecule that utilizes fibrillation to protect the host from a wide range of infectious agents. In humans and in animal models, infection of the brain frequently leads to increased amyloidogenic processing of the amyloid-β protein precursor (AβPP) and resultant fibrillary aggregates of Aβ. Evidence from in vitro and in vivo studies demonstrates that Aβ oligomers have potent, broad-spectrum antimicrobial properties by forming fibrils that entrap pathogens and disrupt cell membranes. Importantly, overexpression of Aβ confers increased resistance to infection from both bacteria and viruses. The antimicrobial role of Aβ may explain why increased rates of infection have been observed in some of the AD clinical trials that depleted Aβ. Perhaps progress toward a cure for AD will accelerate once treatment strategies begin to take into account the likely physiological functions of this enigmatic peptide.
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Affiliation(s)
- Maya L Gosztyla
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA
| | - Holly M Brothers
- Department of Psychology, The Ohio State University, Columbus, OH, USA
| | - Stephen R Robinson
- Discipline of Psychology, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
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Sokol DK, Maloney B, Westmark CJ, Lahiri DK. Novel Contribution of Secreted Amyloid-β Precursor Protein to White Matter Brain Enlargement in Autism Spectrum Disorder. Front Psychiatry 2019; 10:165. [PMID: 31024350 PMCID: PMC6469489 DOI: 10.3389/fpsyt.2019.00165] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/06/2019] [Indexed: 12/27/2022] Open
Abstract
The most replicated neuroanatomical finding in autism is the tendency toward brain overgrowth, especially in younger children. Research shows that both gray and white matter are enlarged. Proposed mechanisms underlying brain enlargement include abnormal inflammatory and neurotrophic signals that lead to excessive, aberrant dendritic connectivity via disrupted pruning and cell adhesion, and enlargement of white matter due to excessive gliogenesis and increased myelination. Amyloid-β protein precursor (βAPP) and its metabolites, more commonly associated with Alzheimer's disease (AD), are also dysregulated in autism plasma and brain tissue samples. This review highlights findings that demonstrate how one βAPP metabolite, secreted APPα, and the ADAM family α-secretases, may lead to increased brain matter, with emphasis on increased white matter as seen in autism. sAPPα and the ADAM family α-secretases contribute to the anabolic, non-amyloidogenic pathway, which is in contrast to the amyloid (catabolic) pathway known to contribute to Alzheimer disease. The non-amyloidogenic pathway could produce brain enlargement via genetic mechanisms affecting mRNA translation and polygenic factors that converge on molecular pathways (mitogen-activated protein kinase/MAPK and mechanistic target of rapamycin/mTOR), promoting neuroinflammation. A novel mechanism linking the non-amyloidogenic pathway to white matter enlargement is proposed: α-secretase and/or sAPPα, activated by ERK receptor signaling activates P13K/AKt/mTOR and then Rho GTPases favoring myelination via oligodendrocyte progenitor cell (OPC) activation of cofilin. Applying known pathways in AD to autism should allow further understanding and provide options for new drug targets.
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Affiliation(s)
- Deborah K. Sokol
- Pediatrics Section, Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Bryan Maloney
- Indiana Alzheimers Disease Center, Department of Psychiatry, Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Cara J. Westmark
- Department of Neurology, University of Wisconsin, Madison, WI, United States
| | - Debomoy K. Lahiri
- Indiana Alzheimers Disease Center, Department of Psychiatry, Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States
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7
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Spitzer P, Condic M, Herrmann M, Oberstein TJ, Scharin-Mehlmann M, Gilbert DF, Friedrich O, Grömer T, Kornhuber J, Lang R, Maler JM. Amyloidogenic amyloid-β-peptide variants induce microbial agglutination and exert antimicrobial activity. Sci Rep 2016; 6:32228. [PMID: 27624303 PMCID: PMC5021948 DOI: 10.1038/srep32228] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 08/04/2016] [Indexed: 11/09/2022] Open
Abstract
Amyloid-β (Aβ) peptides are the main components of the plaques found in the brains of patients with Alzheimer's disease. However, Aβ peptides are also detectable in secretory compartments and peripheral blood contains a complex mixture of more than 40 different modified and/or N- and C-terminally truncated Aβ peptides. Recently, anti-infective properties of Aβ peptides have been reported. Here, we investigated the interaction of Aβ peptides of different lengths with various bacterial strains and the yeast Candida albicans. The amyloidogenic peptides Aβ1-42, Aβ2-42, and Aβ3p-42 but not the non-amyloidogenic peptides Aβ1-40 and Aβ2-40 bound to microbial surfaces. As observed by immunocytochemistry, scanning electron microscopy and Gram staining, treatment of several bacterial strains and Candida albicans with Aβ peptide variants ending at position 42 (Aβx-42) caused the formation of large agglutinates. These aggregates were not detected after incubation with Aβx-40. Furthermore, Aβx-42 exerted an antimicrobial activity on all tested pathogens, killing up to 80% of microorganisms within 6 h. Aβ1-40 only had a moderate antimicrobial activity against C. albicans. Agglutination of Aβ1-42 was accelerated in the presence of microorganisms. These data demonstrate that the amyloidogenic Aβx-42 variants have antimicrobial activity and may therefore act as antimicrobial peptides in the immune system.
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Affiliation(s)
- Philipp Spitzer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Mateja Condic
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Martin Herrmann
- Department of Medicine III, Institute for Clinical Immunology, Friedrich-Alexander-University Erlangen-Nuremberg, Gluecksstraße 4a, D-91054 Erlangen, Germany
| | - Timo Jan Oberstein
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Marina Scharin-Mehlmann
- Electron Devices, Friedrich-Alexander-University Erlangen-Nuremberg, Cauerstraße 6, D-91058 Erlangen, Germany
| | - Daniel F Gilbert
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nuremberg, Paul-Gordan-Str. 3, D-91052 Erlangen, Germany
| | - Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nuremberg, Paul-Gordan-Str. 3, D-91052 Erlangen, Germany
| | - Teja Grömer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Roland Lang
- Institute of Clinical Microbiology, Immunology and Hygiene, Friedrich-Alexander-University Erlangen-Nuremberg, Wasserturmstr. 3/5, D-91054 Erlangen, Germany
| | - Juan Manuel Maler
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
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Miklossy J, McGeer PL. Common mechanisms involved in Alzheimer's disease and type 2 diabetes: a key role of chronic bacterial infection and inflammation. Aging (Albany NY) 2016; 8:575-88. [PMID: 26961231 PMCID: PMC4925815 DOI: 10.18632/aging.100921] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 02/20/2016] [Indexed: 12/30/2022]
Abstract
Strong epidemiologic evidence and common molecular mechanisms support an association between Alzheimer's disease (AD) and type 2-diabetes. Local inflammation and amyloidosis occur in both diseases and are associated with periodontitis and various infectious agents. This article reviews the evidence for the presence of local inflammation and bacteria in type 2 diabetes and discusses host pathogen interactions in chronic inflammatory disorders. Chlamydophyla pneumoniae, Helicobacter pylori and spirochetes are demonstrated in association with dementia and brain lesions in AD and islet lesions in type 2 diabetes. The presence of pathogens in host tissues activates immune responses through Toll-like receptor signaling pathways. Evasion of pathogens from complement-mediated attack results in persistent infection, inflammation and amyloidosis. Amyloid beta and the pancreatic amyloid called amylin bind to lipid bilayers and produce Ca(2+) influx and bacteriolysis. Similarly to AD, accumulation of amylin deposits in type 2 diabetes may result from an innate immune response to chronic bacterial infections, which are known to be associated with amyloidosis. Further research based on an infectious origin of both AD and type 2 diabetes may lead to novel treatment strategies.
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Affiliation(s)
- Judith Miklossy
- International Alzheimer Research Centre, Prevention Alzheimer International Foundation, Martigny-Croix, Switzerland
| | - Patrick L. McGeer
- Kinsmen Laboratory of Neurological Research, The University of British Columbia, Vancouver, B.C, Canada
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Condic M, Oberstein TJ, Herrmann M, Reimann MC, Kornhuber J, Maler JM, Spitzer P. N-truncation and pyroglutaminylation enhances the opsonizing capacity of Aβ-peptides and facilitates phagocytosis by macrophages and microglia. Brain Behav Immun 2014; 41:116-25. [PMID: 24876064 DOI: 10.1016/j.bbi.2014.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 04/18/2014] [Accepted: 05/03/2014] [Indexed: 10/25/2022] Open
Abstract
Abnormal accumulations of amyloid-β (Aβ)-peptides are one of the pathological hallmarks of Alzheimer's disease (AD). The precursor of the Aβ-peptides, the amyloid precursor protein (APP), is also found in peripheral blood cells, but its function in these cells remains elusive. We previously observed that mononuclear phagocytes release Aβ-peptides during activation and phagocytosis, suggesting a physiologic role in inflammatory processes. Here, we show that supplementing the media with soluble N-terminally truncated Aβ(2-40) and Aβ(2-42) as well as Aβ(1-42) induced the phagocytosis of polystyrene particles (PSPs) by primary human monocytes. If the PSPs were pre-incubated with Aβ-peptides, phagocytosis was induced by all tested Aβ-peptide species. N-terminally truncated Aβ(x-42) induced the phagocytosis of PSPs significantly more effectively than did Aβ(x-40). Similarly, the phagocytosis of Escherichia coli by GM-CSF- and M-CSF-elicited macrophages as well as microglia was particularly facilitated by pre-incubation with N-terminally truncated Aβ(x-42). The proinflammatory polarization of monocytes was indicated by the reduced MSRI expression and IL-10 secretion after phagocytosis of PSPs coated with Aβ(1-42), Aβ(2-42) and Aβ(3p-42). Polarization of the macrophages by GM-CSF reduced the phagocytic activity, but it did not affect the capabilities of Aβ-peptides to opsonize prey. Taken together, Aβ-peptides support phagocytosis as soluble factors and act as opsonins. Differential effects among the Aβ-peptide variants point to distinct mechanisms of interaction among monocytes/macrophages, prey and Aβ-peptides. A proinflammatory polarization induced by the phagocytosis of Aβ-peptide coated particles may provide a model for the chronic inflammatory reaction and sustained plaque deposition in AD.
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Affiliation(s)
- Mateja Condic
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Timo Jan Oberstein
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Martin Herrmann
- Department of Medicine III, Institute for Clinical Immunology, Friedrich-Alexander-University Erlangen-Nuremberg, Gluecksstraße 4a, D-91054 Erlangen, Germany
| | - Mareike Carola Reimann
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Juan Manuel Maler
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Philipp Spitzer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany.
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10
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Olsson B, Legros L, Guilhot F, Strömberg K, Smith J, Livesey FJ, Wilson DH, Zetterberg H, Blennow K. Imatinib treatment and Aβ42 in humans. Alzheimers Dement 2013; 10:S374-80. [PMID: 24331439 DOI: 10.1016/j.jalz.2013.08.283] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 08/16/2013] [Accepted: 08/30/2013] [Indexed: 10/25/2022]
Abstract
BACKGROUND The first-line treatment in chronic myeloid leukemia (CML), imatinib, has been shown to decrease the production of amyloid-β (Aβ) in vitro and in animal studies. However, whether imatinib has this effect in humans is not known. METHODS Plasma levels of Aβ42 were analyzed in sequential samples from CML patients treated with imatinib (n=51). The effect of imatinib on Aβ production was also investigated in human embryonic kidney 293 (HEK293) cells overexpressing the amyloid precursor protein (APP) with the Swedish mutation, in mouse primary cortical neurons and in human Down syndrome embryonic stem-cell-derived cortical neurons. RESULTS Twelve months of imatinib treatment did not lower plasma Aβ42 levels in CML patients, and imatinib treatment did not lead to less Aβ42 production in any of the in vitro models whereas β- and γ-secretase inhibitors did. CONCLUSION These data question the previously described role of imatinib in inhibiting amyloidogenic APP processing and as a drug candidate for AD.
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Affiliation(s)
- Bob Olsson
- Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden.
| | - Laurence Legros
- Service d'Hématologie Clinique, Hôpital de l'Archet, Nice, France
| | | | | | - James Smith
- Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Frederick J Livesey
- Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden; UCL Institute of Neurology, Queen Square, London, UK
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden
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Chasseigneaux S, Allinquant B. Functions of Aβ, sAPPα and sAPPβ : similarities and differences. J Neurochem 2011; 120 Suppl 1:99-108. [PMID: 22150401 DOI: 10.1111/j.1471-4159.2011.07584.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Amyloid peptide (Aβ) is derived from the cleavage of amyloid precursor protein (APP), which also generates the soluble peptide APPβ (sAPPβ). An antagonist and major APP metabolic pathway involves cleavage by alpha secretase, which releases sAPPα. Although soluble Aβ oligomers are neurotoxic, Aβ monomers share similar properties with sAPPα. These include neurotrophic and neuroprotective effects, as well as stimulation of neural-progenitor proliferation. The properties of Aβ monomers and the neurotrophic capacity of sAPPβ to stimulate axonal outgrowth suggest that Aβ production is not deleterious per se. Consequently, therapeutic strategies for Alzheimer's disease that are targeted at Aβ-cleaving enzymes should modulate rather than inhibit Aβ generation. These strategies should focus on the factors that induce the conversion of Aβ monomers into toxic soluble oligomers. Another interesting therapeutic approach is to focus on the mechanisms of the different properties of sAPPα. Indeed, increasing sAPPα levels could shift proliferating cells towards tumorigenesis. In contrast to its neuroprotective effects, sAPPα is also able to activate microglia, leading to neurotoxicity. Understanding the mechanisms that underlie the different properties of sAPPα could therefore lead to the development of therapeutic strategies against Alzheimer's disease, which could be curative as well as preventive.
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Affiliation(s)
- Stéphanie Chasseigneaux
- INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Bernadette Allinquant
- INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
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12
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Bailey AR, Hou H, Obregon DF, Tian J, Zhu Y, Zou Q, Nikolic WV, Bengtson M, Mori T, Murphy T, Tan J. Aberrant T-lymphocyte development and function in mice overexpressing human soluble amyloid precursor protein-α: implications for autism. FASEB J 2011; 26:1040-51. [PMID: 22085641 DOI: 10.1096/fj.11-195438] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Abnormalities in T-lymphocyte populations and function are observed in autism. Soluble amyloid precursor protein α (sAPP-α) is elevated in some patients with autism and is known to be produced by immune cells. In light of the well-established role of sAPP-α in proliferation, growth, and survival of neurons, we hypothesized an analogous role in the immune system. Thus, we explored whether sAPP-α could modulate immune development and function, especially aspects of the pinnacle cell of the adaptive arm of the immune system: the T cell. To do this, we generated mice overexpressing human sAPP-α and characterized elements of T-cell development, signal transduction, cytokine production, and innate/adaptive immune functions. Here, we report that transgenic sAPP-α-overexpressing (TgsAPP-α) mice displayed increased proportions of CD8(+) T cells, while effector memory T cells were decreased in the thymus. Overall apoptotic signal transduction was decreased in the thymus, an effect that correlated with dramatic elevations in Notch1 activation; while active-caspase-3/total-caspase-3 and Bax/Bcl-2 ratios were decreased. Greater levels of IFN-γ, IL-2, and IL-4 were observed after ex vivo challenge of TgsAPP-α mouse splenocytes with T-cell mitogen. Finally, after immunization, splenocytes from TgsAPP-α mice displayed decreased levels IFN-γ, IL-2, and IL-4, as well as suppressed ZAP70 activation, after recall antigen stimulation. Given elevated levels of circulating sAPP-α in some patients with autism, sAPP-α could potentially drive aspects of immune dysfunction observed in these patients, including dysregulated T-cell apoptosis, aberrant PI3K/AKT signaling, cytokine alterations, and impaired T-cell recall stimulation.
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Affiliation(s)
- Antoinette R Bailey
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Neurosciences, College of Medicine, University of South Florida, 3515 E. Fletcher Ave. Tampa, FL 33613, USA
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13
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Abstract
Chronic spirochetal infection can cause slowly progressive dementia, cortical atrophy and amyloid deposition in the atrophic form of general paresis. There is a significant association between Alzheimer disease (AD) and various types of spirochete (including the periodontal pathogen Treponemas and Borrelia burgdorferi), and other pathogens such as Chlamydophyla pneumoniae and herpes simplex virus type-1 (HSV-1). Exposure of mammalian neuronal and glial cells and organotypic cultures to spirochetes reproduces the biological and pathological hallmarks of AD. Senile-plaque-like beta amyloid (Aβ) deposits are also observed in mice following inhalation of C. pneumoniae in vivo, and Aβ accumulation and phosphorylation of tau is induced in neurons by HSV-1 in vitro and in vivo. Specific bacterial ligands, and bacterial and viral DNA and RNA all increase the expression of proinflammatory molecules, which activates the innate and adaptive immune systems. Evasion of pathogens from destruction by the host immune reactions leads to persistent infection, chronic inflammation, neuronal destruction and Aβ deposition. Aβ has been shown to be a pore-forming antimicrobial peptide, indicating that Aβ accumulation might be a response to infection. Global attention and action is needed to support this emerging field of research because dementia might be prevented by combined antibiotic, antiviral and anti-inflammatory therapy.
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Miklossy J. Alzheimer's disease - a neurospirochetosis. Analysis of the evidence following Koch's and Hill's criteria. J Neuroinflammation 2011; 8:90. [PMID: 21816039 PMCID: PMC3171359 DOI: 10.1186/1742-2094-8-90] [Citation(s) in RCA: 217] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 08/04/2011] [Indexed: 12/14/2022] Open
Abstract
It is established that chronic spirochetal infection can cause slowly progressive dementia, brain atrophy and amyloid deposition in late neurosyphilis. Recently it has been suggested that various types of spirochetes, in an analogous way to Treponema pallidum, could cause dementia and may be involved in the pathogenesis of Alzheimer's disease (AD). Here, we review all data available in the literature on the detection of spirochetes in AD and critically analyze the association and causal relationship between spirochetes and AD following established criteria of Koch and Hill. The results show a statistically significant association between spirochetes and AD (P = 1.5 × 10-17, OR = 20, 95% CI = 8-60, N = 247). When neutral techniques recognizing all types of spirochetes were used, or the highly prevalent periodontal pathogen Treponemas were analyzed, spirochetes were observed in the brain in more than 90% of AD cases. Borrelia burgdorferi was detected in the brain in 25.3% of AD cases analyzed and was 13 times more frequent in AD compared to controls. Periodontal pathogen Treponemas (T. pectinovorum, T. amylovorum, T. lecithinolyticum, T. maltophilum, T. medium, T. socranskii) and Borrelia burgdorferi were detected using species specific PCR and antibodies. Importantly, co-infection with several spirochetes occurs in AD. The pathological and biological hallmarks of AD were reproduced in vitro by exposure of mammalian cells to spirochetes. The analysis of reviewed data following Koch's and Hill's postulates shows a probable causal relationship between neurospirochetosis and AD. Persisting inflammation and amyloid deposition initiated and sustained by chronic spirochetal infection form together with the various hypotheses suggested to play a role in the pathogenesis of AD a comprehensive entity. As suggested by Hill, once the probability of a causal relationship is established prompt action is needed. Support and attention should be given to this field of AD research. Spirochetal infection occurs years or decades before the manifestation of dementia. As adequate antibiotic and anti-inflammatory therapies are available, as in syphilis, one might prevent and eradicate dementia.
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Affiliation(s)
- Judith Miklossy
- International Alzheimer Research Center, Prevention Alzheimer Foundation, Martigny-Combe, Switzerland.
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15
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Smirnov A, Trupp A, Henkel A, Bloch E, Reulbach U, Lewczuk P, Riggert J, Kornhuber J, Wiltfang J. Differential processing and secretion of Aβ peptides and sAPPα in human platelets is regulated by thrombin and prostaglandine 2. Neurobiol Aging 2009; 30:1552-62. [DOI: 10.1016/j.neurobiolaging.2007.12.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 12/06/2007] [Accepted: 12/11/2007] [Indexed: 10/22/2022]
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16
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Laky K, Annaert W, Fowlkes BJ. Amyloid precursor family proteins are expressed by thymic and lymph node stromal cells but are not required for lymphocyte development. Int Immunol 2009; 21:1163-74. [PMID: 19710207 PMCID: PMC2750246 DOI: 10.1093/intimm/dxp083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pharmacological inhibitors that block amyloid precursor protein (APP) cleavage and the formation of senile plaques are under development for the treatment of familial Alzheimer's disease. Unfortunately, many inhibitors that block γ-secretase-mediated cleavage of APP also have immunosuppressive side effects. In addition to APP, numerous other proteins undergo γ-secretase-mediated cleavage. In order to develop safer inhibitors, it is necessary to determine which of the γ-secretase substrates contribute to the immunosuppressive effects. Because APP family members are widely expressed and are reported to influence calcium flux, transcription and apoptosis, they could be important for normal lymphocyte maturation. We find that APP and amyloid precursor-like protein 2 are expressed by stromal cells of thymus and lymph nodes, but not by lymphocytes. Although signals provided by thymic stromal cells are critical for normal T cell differentiation, lymphocyte development proceeds unperturbed in mice deficient for these APP family members.
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Affiliation(s)
- Karen Laky
- Laboratory of Cellular and Molecular Immunology, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892-0420, USA
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17
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Lee YH, Tharp WG, Maple RL, Nair S, Permana PA, Pratley RE. Amyloid precursor protein expression is upregulated in adipocytes in obesity. Obesity (Silver Spring) 2008; 16:1493-500. [PMID: 18483477 DOI: 10.1038/oby.2008.267] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The aim of this study was to determine whether amyloid precursor protein (APP) is expressed in human adipose tissue, dysregulated in obesity, and related to insulin resistance and inflammation. APP expression was examined by microarray expression profiling of subcutaneous abdominal adipocytes (SAC) and cultured preadipocytes from obese and nonobese subjects. Quantitative real-time PCR (QPCR) was performed to confirm differences in APP expression in SAC and to compare APP expression levels in adipose tissue, adipocytes, and stromal vascular cells (SVCs) from subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) specimens. Adipose tissue samples were also examined by western blot and immunofluorescence confocal microscopy. Microarray studies demonstrated that APP mRNA expression levels were higher in SAC (approximately 2.5-fold) and preadipocytes (approximately 1.4) from obese subjects. Real-time PCR confirmed increased APP expression in SAC in a separate group of obese compared with nonobese subjects (P=0.02). APP expression correlated to in vivo indices of insulin resistance independently of BMI and with the expression of proinflammatory genes, such as monocyte chemoattractant protein-1 (MCP-1) (R=0.62, P=0.004), macrophage inflammatory protein-1alpha (MIP-1alpha) (R=0.60, P=0.005), and interleukin-6 (IL-6) (R=0.71, P=0.0005). Full-length APP protein was detected in adipocytes by western blotting and APP and its cleavage peptides, Abeta40 and Abeta42, were observed in SAT and VAT by immunofluorescence confocal microscopy. In summary, APP is highly expressed in adipose tissue, upregulated in obesity, and expression levels correlate with insulin resistance and adipocyte cytokine expression levels. These data suggest a possible role for APP and/or Abeta in the development of obesity-related insulin resistance and adipose tissue inflammation.
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Affiliation(s)
- Yong-Ho Lee
- Diabetes and Metabolism Translational Medicine Unit, University of Vermont College of Medicine, Burlington, Vermont, USA
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18
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Greenberg SA. Comment on 'Interrelation of inflammation and APP in sIBM: IL-1 induces accumulation of -amyloid in skeletal muscle'. Brain 2008; 132:e106; author reply e107. [DOI: 10.1093/brain/awn163] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Maesako Y, Uchiyama T, Ohno H. Comparison of gene expression profiles of lymphoma cell lines from transformed follicular lymphoma, Burkitt's lymphoma and de novo diffuse large B-cell lymphoma. Cancer Sci 2003; 94:774-81. [PMID: 12967475 PMCID: PMC11160262 DOI: 10.1111/j.1349-7006.2003.tb01518.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2003] [Revised: 06/26/2003] [Accepted: 07/07/2003] [Indexed: 11/28/2022] Open
Abstract
To determine the specific gene expression in B-cell lymphoma subtypes, we compared expression profiles of cell lines from transformed follicular lymphoma (tFL), Epstein-Barr virus-negative (EBV(-)) Burkitt's lymphoma (BL) and EBV(+)BL. Complementary DNAs were synthesized from these cell lines and hybridized with the Atlas Human 1.2 Array membrane. Hierarchical clustering analysis based upon the levels of 43 genes highlighted characteristic expression patterns of the 3 lymphoma subtypes. Genes expressed at higher levels in tFL than EBV(-)BL and EBV(+)BL included calcium/calmodulin-dependent protein kinase I (CAMK1) and mitogen-activated protein kinase 10 (MAPK10). EBV(-)BL was characterized by high-level expression of amyloid beta precursor protein (APP), heat shock 27 kD protein 1 (HSPB1) and mothers against decapentaplegic homolog 1 (MADH1). Gardner-Rasheed feline sarcoma viral oncogene homolog (FGR) was the most significant gene to delineate EBV(+)BL. A subtype prediction algorithm using 34 genes correctly classified 22 (92%) of 24 lymphomas into FL/tFL, EBV(-)BL or EBV(+)BL. By comparison with normal reference B-cell materials, the expression patterns of the selected genes were characteristic of lymphomas. We extended the clustering analysis to cell lines from de novo diffuse large B-cell lymphoma (DLBCL). The DLBCL cell lines were either separated from the former 3 lymphoma subtypes or segregated with EBV(+)BL, possibly reflecting variable genetic abnormalities. The associations of CAMK1 with tFL, APP and MADH1 with EBV(-)BL, FGR with EBV(+)BL, and BCL2 with tFL and DLBCL were confirmed by real-time quantitative reverse transcriptase-mediated polymerase chain reaction assays. This study has provided new molecular markers, expressions of which are closely associated with B-cell lymphoma subtypes.
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MESH Headings
- B-Lymphocytes/physiology
- Biomarkers, Tumor/analysis
- Cell Line, Transformed/virology
- Cells, Cultured
- DNA, Complementary/genetics
- Epstein-Barr Virus Infections/virology
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
- Herpesvirus 4, Human/pathogenicity
- Humans
- Lymphoma, B-Cell/genetics
- Lymphoma, Follicular/genetics
- Lymphoma, Large B-Cell, Diffuse/genetics
- Oligonucleotide Array Sequence Analysis
- RNA, Messenger/analysis
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Affiliation(s)
- Yoshitomo Maesako
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
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20
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Noonan CW, Reif JS, Burch JB, Ichinose TY, Yost MG, Magnusson K. Relationship between amyloid beta protein and melatonin metabolite in a study of electric utility workers. J Occup Environ Med 2002; 44:769-75. [PMID: 12185798 DOI: 10.1097/00043764-200208000-00012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This study assessed the relationship between occupational magnetic field exposure, the urinary melatonin metabolite 6-hydroxymelatonin sulfate (6-OHMS), and concentrations of blood-borne soluble amyloid beta (A beta), a protein associated with the hallmark lesions of Alzheimer's disease (AD). Blood and urine samples were obtained from male electric utility workers (n = 60) to quantify two lengths of the protein in plasma, A beta (amino acids 1-40) and A beta (1-42), and the urinary concentrations of 6-OHMS. Average A beta levels were positively associated with categories of magnetic field exposure, but this relationship was weak and did not achieve statistical significance. The melatonin metabolite was inversely correlated with A beta (1-42) and the ratio of A beta (1-42) to A beta (1-40). This observation is consistent with recent in vitro data and provides a plausible mechanism for the association between magnetic field exposure and AD that has been observed in some studies.
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Affiliation(s)
- Curtis W Noonan
- Department of Environmental Health, Colorado State University, Fort Collins, Colorado, USA.
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21
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Walter J, Schindzielorz A, Hartung B, Haass C. Phosphorylation of the beta-amyloid precursor protein at the cell surface by ectocasein kinases 1 and 2. J Biol Chem 2000; 275:23523-9. [PMID: 10806211 DOI: 10.1074/jbc.m002850200] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The beta-amyloid precursor protein (betaAPP) is one of the rare proteins known to be phosphorylated within its ectodomain. We have shown previously that betaAPP can be phosphorylated within secretory vesicles and at the cell surface (Walter, J., Capell, A., Hung, A. Y. , Langen, H., Schnölzer, M., Thinakaran, G., Sisodia, S. S., Selkoe, D. J., and Haass, C. (1997) J. Biol. Chem. 272, 1896-1903). We have now specifically characterized the phosphorylation of cell surface-located betaAPP and identified two ectoprotein kinases that phosphorylate betaAPP at the outer face of the plasma membrane. By using selective protein kinase inhibitors and by investigating the usage of ATP and GTP as cosubstrates, we demonstrate that membrane-bound betaAPP as well as secreted forms of betaAPP can be phosphorylated by casein kinase (CK) 1- and CK2-like ectoprotein kinases. The ectodomain of betaAPP was also phosphorylated by purified CK1 and CK2 in vitro, but not by protein kinases A and C. Phosphorylation of betaAPP by ectoprotein kinases and by purified CK1 and CK2 occurred within an acidic domain in the N-terminal half of the protein. Heparin strongly inhibited the phosphorylation of cell-surface betaAPP by ecto-CK1 and ecto-CK2, indicating a regulatory role of this extracellular matrix component in betaAPP phosphorylation.
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Affiliation(s)
- J Walter
- Adolf-Butenandt-Institut, Department of Biochemistry, Laboratory for Alzheimer's Disease Research, Ludwig-Maximilians-Universät München, Schillerstrasse 44, D-80336 Munich, Germany.
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22
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Kimura A, Kakinuma K, Yonezawa S, Takahashi T. Expression of β-Amyloid Precursor Protein in the Porcine Ovary. Zoolog Sci 2000. [DOI: 10.2108/zsj.17.769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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23
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Marx F, Blasko I, Zisterer K, Grubeck-Loebenstein B. Transfected human B cells: a new model to study the functional and immunostimulatory consequences of APP production. Exp Gerontol 1999; 34:783-95. [PMID: 10579638 DOI: 10.1016/s0531-5565(99)00049-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The ubiquitously expressed Alzheimer amyloid precursor protein (APP) has raised wide interest in view of its connection with Alzheimer's disease. We now provide a novel extraneuronal cell model in which human Epstein-Barr virus transformed B cells that constitutively hardly produce APP are transfected with wild-type or mutated APP695, harboring the Swedish mutation APPsw, or a dilysine endoplasmic reticulum retrieval motif--APP(ER). This leads to the generation of three types of cells, one with a high secretion of soluble APPs but low levels of intracellular APP, another with a high intracellular APP retention but a low APP secretion, and a third in which APP maturation and secretion are strongly impaired. The suitability of our cell model for various purposes is proven by its usage in different systems. We demonstrate that it is a useful tool for studies on the physiology of APPs and represents a good model system to analyze the cellular mechanisms of Abeta-directed autoimmune reactivity.
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Affiliation(s)
- F Marx
- Institute for Biomedical Aging Research of the Austrian Academy of Sciences, Innsbruck
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24
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Schulze P, Thal D, Bettag M, Schober R. Brain tissue damage and regeneration monitored by ?-amyloid precursor protein in experimental laser-induced interstitial thermotherapy. Neuropathology 1998. [DOI: 10.1111/j.1440-1789.1998.tb00078.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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25
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Johnston JA, Lannfelt L, Wiehager B, O'Neill C, Cowburn RF. Amyloid precursor protein heat shock response in lymphoblastoid cell lines bearing presenilin-1 mutations. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1362:183-92. [PMID: 9540849 DOI: 10.1016/s0925-4439(97)00074-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The amyloid precursor protein (APP) gene promoter contains a heat shock element. An abnormal APP heat shock response could increase accumulation of A beta, the APP metabolite found in Alzheimer's disease amyloid plaques. Since A beta production is affected by presenilin-1 (PS-1) mutations, we investigated whether basal APP levels or response to heat shock were altered in lymphoblastoid cell lines from 8 PS-1 mutation-bearers and 9 control members of Alzheimer's disease families. Lymphoblastoid cell lines were incubated at 42 degrees C for 35 min and allowed to recover at 37 degrees C for 1, 3, 8, 24 and 48 h. APP mRNA levels, quantified using RNA-RNA solution hybridisation, increased significantly at 1 and 3 h post-heat shock to between 123% and 163% of pre-heat shock (0 h) levels and returned to normal by 8 h. Semi-quantitative Western immunoblotting of cell lysates using the 22C11 antibody detected two major bands, migrating at approximately 145 and approximately 120 kDa. Band optical densities increased significantly at 3 h to approximately 155% of 0 h levels, following the increase in APP mRNA levels and showing a similar reversibility. APP mRNA and protein responses were comparable in the PS-1 mutation-bearing and control cell lines. This study shows that both APP mRNA and protein are induced in lymphoblastoid cell lines following heat shock and that this response is not affected by PS-1 mutations which are pathogenic for Alzheimer's disease.
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Affiliation(s)
- J A Johnston
- Karolinska Institute, Department of Clinical Neuroscience and Family Medicine, Novum KFC, Huddinge, Sweden.
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26
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Schubert W, Agha-Amiri K, Mayboroda O, Rethfeldt C. Dipeptidyl peptidase IV (CD26) and Alzheimer amyloid protein precursor (APP) in polymyositis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 421:273-7. [PMID: 9330708 DOI: 10.1007/978-1-4757-9613-1_36] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- W Schubert
- Otto-von-Guericke-University of Magdeburg, Institute of Medical Neurobiology, Medical Faculty, Germany
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27
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Suh YH, Choi W, Kim SH, Kim JS, Rhi BY, Chong YH, Woo JI, Lee KW. Expression of Alzheimer's amyloid precursor protein in human lymphocyte. Arch Gerontol Geriatr 1997; 24:1-7. [PMID: 15374130 DOI: 10.1016/s0167-4943(96)00721-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/1996] [Revised: 05/29/1996] [Accepted: 06/06/1996] [Indexed: 10/18/2022]
Abstract
Beta-amyloid precursor protein (betaAPP) has been shown to be involved in cell growth regulation. In spleen, the majority of cells showing betaAPP like immunoreactivity was found in the T cell-dependent zone. In Northern blot, the expression of betaAPP was increased to reach the peak at 72 h after the treatment of phytohemagglutinin (PHA). But, in cytofluorometry, almost all CD4(+) T helper/inducer cells and the majority of CD(8+) T suppressor/cytotoxic cells show betaAPP immunoreactivity which remained constant during the stimulation with PHA. These results suggest that betaAPP is a surface molecule of T lymphocyte and the turnover or release of APP might be increased with the treatment of T cell mitogen.
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Affiliation(s)
- Y H Suh
- Department of Pharmacology, College of Medicine, Neuroscience Research Institute, Seoul National University, 28 Yongon-dong, Chongno-gu, Seoul 110-799, South Korea
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28
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Pallister C, Jung SS, Shaw I, Nalbantoglu J, Gauthier S, Cashman NR. Lymphocyte content of amyloid precursor protein is increased in Down's syndrome and aging. Neurobiol Aging 1997; 18:97-103. [PMID: 8983037 DOI: 10.1016/s0197-4580(96)00207-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We quantified cellular amyloid precursor protein (APP) in ethanol-permeabilized peripheral lymphocytes from 13 subjects with Alzheimer's disease (AD), 11 subjects with Down's syndrome (DS), and 13 healthy elderly and 31 healthy young controls. APP content was analyzed by indirect immunofluorescence and flow cytometry, using the 22C11 monoclonal antibody (mAb) directed against an N-terminal domain of APP. Authenticity of 22C11 APP signal was confirmed by immunoblotting and flow cytometry studies with the mAb 6E10, directed against the A beta domain of APP. Consistent with gene dosage, patients with DS had 1.51-fold higher lymphocyte APP signal than age-matched normal young subjects (corrected p < 0.05). Both AD patients and elderly control groups had significantly increased lymphocyte APP signal compared to young controls (either comparison corrected p < 0.01). Indeed, increasing age in non-DS subjects was significantly correlated with lymphocyte APP (r = 0.508, p < 0.0001), such that APP immunoreactivity more than doubled from 20 to 80 years. Lymphocyte APP was nonsignificantly higher in AD vs. aged controls in this small sample. Increased cellular APP content in DS and aging may correspond to generalized alterations in expression or processing of this molecule, and suggests a novel determinant for the timing of AD onset.
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Affiliation(s)
- C Pallister
- Department of Microbiology and Immunology, McGill Centre for Studies in Aging, McGill University, Montréal, Canada
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29
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Bullido MJ, Muñoz-Fernandez MA, Recuero M, Fresno M, Valdivieso F. Alzheimer's amyloid precursor protein is expressed on the surface of hematopoietic cells upon activation. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1313:54-62. [PMID: 8781550 DOI: 10.1016/0167-4889(96)00015-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A4-amyloid is the major component of senile plaques and neurofibrillary tangles found in the brain of patients suffering Alzheimer's disease. This 39-42 amino acid peptide is derived from a larger precursor protein (APP). Since APP gene encodes for a putative membrane protein, the study of APP expression at the cell surface may provide useful data for understanding its physiological function. In this report, we present data on APP expression, that was detected by APP specific mAbs in cells of the hematopoietic system. APP was weakly expressed on the cell surface of resting human lymphocytes and monocytes, but it could be induced to the surface of those cells upon stimulation. The cell activators capable of inducing APP membrane expression comprehended mitogenic lectins, calcium ionophores, phosphatase inhibitors, and anti mu-chain or anti-CD3 antibodies in B and T cells, respectively. Interestingly, phorbol esters were able to induce APP membrane expression in monocytic, but not in lymphoid cells. In contrast to lymphocytes and monocytes, granulocytes never expressed cell surface or cytoplasmic APP, even after the activation. The induction of membrane APP in response to lymphocyte activation signals, including antibodies to the antigen receptor of B and T cells, raises the possibility that APP might play the role of a cell surface receptor in the immune system.
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Affiliation(s)
- M J Bullido
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Spain
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30
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Vostrov AA, Quitschke WW, Vidal F, Schwarzman AL, Goldgaber D. USF binds to the APB alpha sequence in the promoter of the amyloid beta-protein precursor gene. Nucleic Acids Res 1995; 23:2734-41. [PMID: 7651835 PMCID: PMC307099 DOI: 10.1093/nar/23.14.2734] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The APB alpha domain in the amyloid beta-protein precursor (APP) promoter contains a nuclear factor binding domain with the core recognition sequence TCAGCT-GAC. Proteins in nuclear extracts from brain and numerous cell lines bind to this domain and it contributes approximately 10-30% to the basal APP promoter activity. Included in this domain is the CANNTG motif, which is recognized by basic helix-loop-helix transcription factors. The same motif is also present in the CDEI element of the yeast centromere and in the adenovirus major late promoter (AdMLP). Here we present evidence based on thermostability, relative binding affinity, eletrophoretic mobility and antibody recognition that the cellular proteins that bind to the APB alpha and CDEI motifs are USF. However, the relative binding affinity for the motifs is different. The affinity of USF for AdMLP is approximately 20-fold higher than for the APB alpha sequence and 5-fold higher than for the CDEI sequence. Mutational analysis suggested that the primary determinant for USF binding affinity resides within the octamer CAGCTGAC, which is composed of the E-box consensus sequence CANNTG followed by the dinucleotide AC. The human homolog of the mouse CDEI binding protein did not bind to either the CDEI sequence or APB alpha.
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Affiliation(s)
- A A Vostrov
- Department of Psychiatry and Behavioral Science, State University of New York at Stony Brook 11794-8101, USA
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31
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Ledoux S, Bergeron C, Nalbantoglu J, Gauthier S, Cashman NR. Polymerase chain reaction quantification of lymphoid amyloid precursor protein mRNAs in Alzheimer's disease and Down's syndrome. Neurosci Lett 1995; 193:137-9. [PMID: 7478160 DOI: 10.1016/0304-3940(95)11681-l] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Amyloid beta-protein, the major constituent of Alzheimer's disease (AD) brain amyloid deposits, is encoded by several alternatively spliced amyloid precursor protein (APP) mRNAs. The well-established associated in Down's syndrome (DS) between APP overproduction and premature development of AD, as well as the recent demonstration of an increase in APP transcripts from lymphoblastoid cells of familial AD cases, suggest aberrant transcriptional regulation of some genes in AD. We assayed steady-state expression of the APP gene transcripts in peripheral blood mononuclear cells (PBMC) of AD and DS patients using quantitative polymerase chain reaction of reverse-transcribed mRNAs, and we compared their levels of PBMC APP expression with those of young and age-matched healthy controls. Results indicate APP mRNAs were of comparable abundance in PBMC obtained from 9 AD patients, 7 young controls and 12 age-matched controls. These data suggest regulation of APP mRNAs is normal in AD and DS PBMC.
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Affiliation(s)
- S Ledoux
- Neuroscience Research Unit, Hôpital Saint-Luc, University of Montreal, Quebec, Canada
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32
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Vasilakos JP, Carroll RT, Emmerling MR, Doyle PD, Davis RE, Kim KS, Shivers BD. Interleukin-1 beta dissociates beta-amyloid precursor protein and beta-amyloid peptide secretion. FEBS Lett 1994; 354:289-92. [PMID: 7957941 DOI: 10.1016/0014-5793(94)01142-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A heightened production of interleukin 1 beta (IL-1 beta) has been reported in microglial-associated amyloid deposits in Alzheimer's disease (AD) brains. These plaques are composed predominantly of beta/A4 peptide derived from beta-amyloid precursor protein (beta APP). We demonstrate that short-term (1 h) IL-1 beta-treatment increases beta APPs secretion and concomitantly decreases cell-associated beta APP in human H4 neuroglioma cells. Long-term (5 h) IL-1 beta treatment did not alter secreted or cell-associated beta APP content. In contrast, the secretion of beta/A4-containing epitope was not affected by short-term IL-1 beta stimulation; however, long-term IL-1 beta treatment decreased the amount of beta/A4-containing epitope secreted from the cells. These results show that IL-1 beta modifies the processing and secretion of beta APP to exacerbate perhaps the neuropathology of AD.
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Affiliation(s)
- J P Vasilakos
- Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Co., Ann Arbor, MI 48105
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33
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Fukuyama R, Murakawa Y, Rapoport SI. Induction of gene expression of amyloid precursor protein (APP) in activated human lymphoblastoid cells and lymphocytes. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1994; 23:93-101. [PMID: 7702710 DOI: 10.1007/bf02815403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To understand the possible role of amyloid precursor protein (APP) in human lymphocytes, and the regulation of APP gene expression in this cell type, we determined levels of cellular APP protein and of mRNA in human T-cell-derived Jurkat cells that were treated with lectin, phorbol ester, and calcium ionophore. We also related these levels to cell aggregation and adhesion. Cell-cell aggregation and cell-plastic adhesion were observed over a 24-h period after incubating cells for 2 h with phytohemagglutinin or phorbol myristate acetate. Cells treated with a calcium ionophore showed no aggregation or adhesion. Western blots indicated no obvious alteration in the level of cellular APP with different treatments. Northern blots showed a significant transient increase of APP mRNA after incubation with the calcium ionophore, whereas phorbol ester treatment showed a slight increase of APP mRNA. We analyzed the level of APP mRNA in human peripheral T cells which had been separated from peripheral lymphocytes. The level increased transiently by up to threefold after treatment with calcium ionophore plus phorbol esters. These data suggest that cell-cell aggregation and cell-matrix adhesion by human lymphocytes are not associated with an increased level of cellular APP protein or of mRNA.
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Affiliation(s)
- R Fukuyama
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892
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34
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Zaidi S, Malter J. Amyloid precursor protein mRNA stability is controlled by a 29-base element in the 3'-untranslated region. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)51039-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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35
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Zaidi S, Denman R, Malter J. Multiple proteins interact at a unique cis-element in the 3'-untranslated region of amyloid precursor protein mRNA. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)51038-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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36
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Quitschke W. Two nuclear factor binding domains activate expression from the human amyloid beta-protein precursor promoter. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)31952-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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37
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Perlmutter LS. Microvascular pathology and vascular basement membrane components in Alzheimer's disease. Mol Neurobiol 1994; 9:33-40. [PMID: 7888105 DOI: 10.1007/bf02816103] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Several factors have highlighted the vasculature in Alzheimer's disease (AD): Cerebral amyloid angiopathy (CAA) is common, amyloid fibrils emanate from the vascular basement membrane (VBM), and similar forms of beta-amyloid are found in vascular and parenchymal amyloid accumulations. The present article discusses the presence of microvascular pathology in AD. Microangiopathy, in addition to neurofibrillary tangles, senile plaques, and CAA, is a common pathologic hallmark of AD. VBM components are associated with amyloid plaques, and nonamyloidotic alterations of the VBM occur in brain regions susceptible to AD lesions. Also, intra-VBM perivascular cells (traditionally called pericytes), a subset of which share the immunophenotype of microglia and other mononuclear phagocytic system (MPS) cells, have been implicated in vascular alterations and cerebrovascular amyloid deposition. Perivascular and parenchymal MPS cells have access to several sources of the beta-amyloid protein precursor, including platelets, circulating white cells, and neurons. MPS cells would thus be ideally situated to uptake and process the precursor, and deposit beta-amyloid in a fashion analogous to that seen in other forms of systemic and cerebral amyloidoses.
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Affiliation(s)
- L S Perlmutter
- Department of Neurology, University of Southern California School of Medicine, Los Angeles 90033
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38
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Perlmutter LS, Myers MA, Barrón E. Vascular basement membrane components and the lesions of Alzheimer's disease: light and electron microscopic analyses. Microsc Res Tech 1994; 28:204-15. [PMID: 8068983 DOI: 10.1002/jemt.1070280305] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Alzheimer's disease (AD) is one of several systemic and cerebral diseases that involve the abnormal deposition of fibrillar proteins called amyloids. All amyloids share conformational and staining characteristics, as well as an association with resident tissue macrophages and two extracellular matrix components [heparan sulfate proteoglycan (HSPG) and amyloid P component]. Vascular, glomerular, and Schwann cell basement membrane pathologies have been documented in many forms of amyloidosis, and often amyloid fibrils fuse to and project from the basement membrane in these diseases. The present report demonstrates the vascular basement membrane (VBM) alterations in AD autopsy samples, and details the methodologies used. Electron microscopy reveals the fusion of amyloid fibrils with the VBM and the alteration of the VBM in the absence of amyloid accumulation. Double-labelling and pre-embed immuno-electron microscopy techniques demonstrate the colocalization of amyloid P component and VBM components with amyloid, and also reveal that amyloid P component is not localized to the cerebral VBM. Finally, a novel correlative light/electron microscopy technique demonstrates the association between amyloid P component and cerebral resident tissue macrophages, the microglia. Taken together, these data suggest that the physicochemical processes of amyloid formation, rather than amyloid deposition, may be responsible for VBM pathology.
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Affiliation(s)
- L S Perlmutter
- Department of Neurology, University of Southern California School of Medicine, Los Angeles 90033
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39
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Savage MJ, Iqbal M, Loh T, Trusko SP, Scott R, Siman R. Cathepsin G: localization in human cerebral cortex and generation of amyloidogenic fragments from the beta-amyloid precursor protein. Neuroscience 1994; 60:607-19. [PMID: 7936190 DOI: 10.1016/0306-4522(94)90490-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Amyloid deposits in Alzheimer's disease, Down's syndrome and aged brain are composed largely of A beta protein, which is generated by proteolytic processing of beta-amyloid precursor protein. Proteases responsible for liberating the A beta protein from the precursor have not yet been identified. Here, we examined the ability of cathepsin G, a chymotrypsin-like protease, to cleave two protease substrates: (i) a fluorogenic hexapeptide, whose sequence spans the cleavage site in the precursor for generating the A beta NH2-terminus, and (ii) recombinant human beta-amyloid precursor protein purified from a baculovirus expression system. Unlike two other members of the chymotrypsin family, cathepsin G readily degraded the hexapeptide. Furthermore, cathepsin G cleaved the beta-amyloid precursor protein to generate several breakdown products, including a prominent 11,500 mol. wt fragment immunoreactive with antibodies directed against the COOH-terminus of the protein. This COOH-terminal fragment co-migrated using two-dimensional isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis with C-100, a recombinant COOH-terminal segment of the beta-amyloid precursor, whose NH2-terminus is one residue upstream of the NH2-terminus of the A beta domain. We also examined the localization of cathepsin G in human brain. The distribution of cathepsin G-containing cells was examined by immunohistochemistry in the temporal cortex of both Alzheimer's and aged control samples. Cathepsin G-like immunoreactivity was contained specifically within neutrophils. As visualized by double-labeling with antibodies to cathepsin G and Factor VIII, neutrophils were most frequently found within meningeal or cortical blood vessels. In addition, occasional neutrophils could be identified without an apparent vascular surround, in the brain parenchyma. By simultaneous labeling with antibodies to cathepsin G and A beta protein, neutrophils were also sometimes found associated with both parenchymal and vessel amyloid deposits; however, these associations were rare. These findings indicate that cathepsin G is capable of cleaving the beta-amyloid precursor protein to liberate the free NH2-terminus of the A beta protein and may have access to areas where this material is deposited in Alzheimer's disease. However, since there is no physical association between neutrophils and deposited amyloid and no increase in the number of neutrophils in an Alzheimer's brain, cathepsin G seems to be an unlikely mediator of amyloid deposition in this disease.
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40
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Meier-Ruge W, Iwangoff P, Bertoni-Freddari C. What is primary and what secondary for amyloid deposition in Alzheimer's disease. Ann N Y Acad Sci 1994; 719:230-7. [PMID: 8010595 DOI: 10.1111/j.1749-6632.1994.tb56831.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The fact that physiologically beta-amyloid precursor proteins are synthesized by all cells of the body without any amyloid deposition in other organs raises a question about an isolated deposition of amyloid in the brain. One of the most important mechanisms in the pathogenesis of senile dementia of the Alzheimer type is the marked decrease of the cerebral glucose metabolism, a cholinergic deficit, by a disturbed acetyl-CoA synthesis and a critically lowered oxidative phosphorylation. Remembering that aging is the most important predisposing factor in the development of Alzheimer's disease, it is argued that a decrease of the oxidative energy metabolism in senile dementia and the resulting ATP deficit may change protein degradation, synaptic transmission and ion homeostasis. Therefore, a more than 50% decline of oxidative energy turnover could be a trigger for an accumulation of beta-amyloid in the brain, because the degradation of beta-amyloid precursor protein could be directly or indirectly disturbed by an ATP deficit. Amyloidosis and a cholinergic deficit in SDAT would then be a secondary phenomenon of the decreased glucose metabolism in the brain.
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Affiliation(s)
- W Meier-Ruge
- Department of Pathology, University Medical School Basel, Switzerland
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41
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Mönning U, Sandbrink R, Banati RB, Masters CL, Beyreuther K. Transforming growth factor beta mediates increase of mature transmembrane amyloid precursor protein in microglial cells. FEBS Lett 1994; 342:267-72. [PMID: 8150082 DOI: 10.1016/0014-5793(94)80514-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
By using the immortalized microglial cell line BV-2, we show that the high expression of the beta A4 amyloid precursor protein (APP), its biogenesis and metabolism is modulated by TGF beta, a cytokine with immunosuppressive activity, and by the microglia-stimulating agent LPS. TGF beta induces accumulation of cellular mature APP, the putative precursor of the amyloid subunit of Alzheimer's disease. LPS leads to an increase in cellular immature, non-amyloidogenic APP and secretion of also non-amyloidogenic APP fragments. We also demonstrate a functional involvement of ECM molecules in the regulation of microglial APP expression at mRNA and protein level by TGF beta and LPS.
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Affiliation(s)
- U Mönning
- Center for Molecular Biology Heidelberg, University of Heidelberg, Germany
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42
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Nordstedt C, Näslund J, Thyberg J, Messamore E, Gandy S, Terenius L. Human neutrophil phagocytic granules contain a truncated soluble form of the Alzheimer beta/A4 amyloid precursor protein (APP). J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36954-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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43
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Maness LM, Banks WA, Podlisny MB, Selkoe DJ, Kastin AJ. Passage of human amyloid beta-protein 1-40 across the murine blood-brain barrier. Life Sci 1994; 55:1643-50. [PMID: 7968239 DOI: 10.1016/0024-3205(94)00331-9] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Previous studies have suggested that the amyloid beta-protein present in the brains of patients with Alzheimer's disease may be derived in part from peripheral blood. We determined that after IV injection of synthetic amyloid beta-protein 1-40 (A beta), labeled with radioactive 125I (I-A beta), radioactivity accumulated in the brains of mice by a nonsaturable mechanism. Radioactivity also accumulated in the brain after the i.v. injection of radioiodinated reverse amyloid beta-protein 40-1 (I-rA beta). Capillary depletion techniques, however, showed I-A beta to have a much greater degree of association with brain capillaries than I-rA beta. Acid precipitation of radioactivity in CSF samples and recovery from cortical homogenates suggested the presence of intact I-A beta within the CNS after peripheral administration. HPLC analysis of cortical homogenates confirmed the presence of intact I-A beta. Gel electrophoresis of the CSF acid precipitates and of the HPLC fractions further verified the presence of intact blood-derived I-A beta peptide in CNS. These results suggest that endogenous bloodborne A beta can enter the CNS after associating with the capillary endothelium to accumulate intact within the parenchymal and CSF spaces of the brain.
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Affiliation(s)
- L M Maness
- Department of Neuroscience, Tulane University School of Medicine, New Orleans, Louisiana
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44
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Banati RB, Gehrmann J, Czech C, Mönning U, Jones LL, König G, Beyreuther K, Kreutzberg GW. Early and rapid de novo synthesis of Alzheimer beta A4-amyloid precursor protein (APP) in activated microglia. Glia 1993; 9:199-210. [PMID: 7507467 DOI: 10.1002/glia.440090305] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Upon acute activation, microglia, the immuneffector cells of the brain parenchyma, express the amyloid precursor protein (APP) that is otherwise prominent in pathological structures related to Alzheimer's disease. In this disease complex amyloid-bearing neuritic plaques contain beta A4-amyloid protein, the APP, and numerous inflammatory proteins. The accompanying activation of microglia has mostly been viewed as a secondary reaction to amyloid deposits. Activation of microglia was performed in a graded fashion. Transection of peripheral nerves such as the facial or sciatic nerve causes a microglial reaction within hours in the nucleus of origin or in projection areas of the CNS. A predominantly glial up-regulation of APP mRNA and protein could be detected as early as 6 h post lesion not only at the site of affected neuronal cell bodies but also in corresponding projection areas. Its time course suggests rapid transneuronal signalling to glial cells in the projection area. Light and electron microscopy demonstrate that microglia, which are cells of mononuclear phagocyte lineage and comprise up to 20% of all glial cells, are the dominant source for non-neuronal APP expression. Ultrastructurally, brain perivascular cells within the basal lamina constitutively express APP and thus are a possible source of vascular amyloid. Additionally, microglia express leukocyte-derived (L)-APP mRNA and protein that have recently been described in mononuclear cells of the immune system. Increased L-APP expression may serve as a potential marker for glial/microglial activation. Such immune-mediated amyloidogenesis initiated by microglia might have implications for the treatment of neurodegenerative diseases.
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Affiliation(s)
- R B Banati
- Department of Neuromorphology, Max-Planck-Institute of Psychiatry, Martinsried, Germany
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45
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Abstract
beta A4, the principal constituent of the brain amyloid collections in Alzheimer's disease, is derived from a much larger precursor, the amyloid protein precursor (APP). APP exists in the blood as full-length, potentially amyloidogenic forms in platelets, and as an attenuated species in plasma and T-lymphocytes. Studies of circulating APP facilitate the elaboration of the function of this protein, as well as the elucidation of its processing in health and disease.
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Affiliation(s)
- A I Bush
- Department of Pathology, University of Melbourne, Victoria Australia
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46
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Hoyer S. Brain oxidative energy and related metabolism, neuronal stress, and Alzheimer's disease: a speculative synthesis. J Geriatr Psychiatry Neurol 1993; 6:3-13. [PMID: 8422269 DOI: 10.1177/002383099300600101] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A reduction in the cerebral metabolic rate of glucose is one of the most predominant abnormalities generally found in the Alzheimer brain, whereas the cerebral metabolic rate of oxygen is diminished only slightly or not at all at the beginning of this dementive disorder. From the cerebral metabolic rates of oxidized glucose and oxygen, the cerebral adenosine triphosphate (ATP) formation rate was calculated in incipient early-onset, incipient late-onset, and stable advanced dementia of the Alzheimer type (DAT). A reduction in ATP formation by various amounts was found, ranging from at least 7% in incipient early-onset DAT, from around 20% in incipient late-onset DAT, and from 35% up to more than 50% in stable advanced dementia. The cerebral diminution in energy availability, along with a loss of functionally important amino acids, ammonia toxicity, supposed membrane damage, dysregulation of Ca2+ homeostasis, and glycogen accumulation in the incipient stages of DAT are assumed to be stress-related abnormalities capable of inducing the formation of heat shock proteins. These events may lead to an enhanced generation of amyloid precursor protein in earlier states of DAT. If abnormally cleaved, amyloid A4 protein may be produced in increased amounts. From the results discussed in this article it is deduced as a speculative synthesis that perturbations in brain oxidative energy and related metabolism may precede the generation of amyloid precursor protein and the formation of plaques in the brain affected by incipient DAT.
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Affiliation(s)
- S Hoyer
- Department of Pathochemistry and General Neurochemistry, Universität of Heidelberg, FRG
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47
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Buxbaum JD, Oishi M, Chen HI, Pinkas-Kramarski R, Jaffe EA, Gandy SE, Greengard P. Cholinergic agonists and interleukin 1 regulate processing and secretion of the Alzheimer beta/A4 amyloid protein precursor. Proc Natl Acad Sci U S A 1992; 89:10075-8. [PMID: 1359534 PMCID: PMC50280 DOI: 10.1073/pnas.89.21.10075] [Citation(s) in RCA: 406] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Activation of protein kinase C by phorbol esters is known to accelerate the processing and secretion of the beta/A4 amyloid protein precursor. We have now examined various first messengers that increase protein kinase C activity of target cells for their ability to affect beta/A4 amyloid protein precursor metabolism. Acetylcholine and interleukin 1, which are altered in Alzheimer disease, were shown to increase processing of the beta/A4 amyloid protein precursor via the secretory cleavage pathway. Cholinergic agonists stimulated secretion in human glioma and neuroblastoma cells as well as in PC12 cells transfected with the M1 receptor, while interleukin 1 stimulated secretion in human endothelial and glioma cells.
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Affiliation(s)
- J D Buxbaum
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY 10021
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48
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Perlmutter LS, Scott SA, Barrón E, Chui HC. MHC class II-positive microglia in human brain: association with Alzheimer lesions. J Neurosci Res 1992; 33:549-58. [PMID: 1484388 DOI: 10.1002/jnr.490330407] [Citation(s) in RCA: 168] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cells of the mononuclear phagocytic system (MPS) present foreign antigen on their cell surfaces bound to major histocompatibility complex (MHC) class II molecules. Previous studies of normal human brain samples reported MHC class II expression primarily by perivascular MPS cells and white matter microglial cells. Marked increases in MHC class II-expressing microglia have been shown in many neuropathologic disorders, including Alzheimer's disease (AD). A close morphologic association between these cells and Alzheimer senile plaque beta-amyloid has been demonstrated. The present study used a mixed aldehyde fixative to enhance the localization of MHC class II-expressing MPS cells in non-AD and AD brain. Two antibodies against MHC class II (HLA-DR; LN3), as well as the lectin Ricinus communis agglutinin (which recognizes both ramified and activated microglia) were used for light and electron microscopic analyses. We now report that MHC class II-expressing ramified microglia are distributed in a uniform reticular array throughout the grey, as well as the white matter in non-AD cases. In AD cases, immunolabelled cells had the morphology of activated microglia, with darkly stained plump somata and short, thick processes. Microglia clustered around senile plaque amyloid and neurofibrillary tangles (NFT), rather than forming the uniform array characteristic of control tissue. Finally, we report that perivascular MPS cells are found in a morphologic relationship with vascular amyloid identical to that seen between microglial cells and senile plaque beta-amyloid. These data suggest that MHC class II-expressing cells may be involved in the degradation of NFT-laden neurons and the posttranslational modification of extracellular-NFT epitopes. In addition, both parenchymal and perivascular MPS cells are ideally situated to uptake and process the beta-amyloid protein precursor and deposit beta-amyloid on senile plaques, NFT, and the cerebrovasculature.
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Affiliation(s)
- L S Perlmutter
- Department of Neurology, University of Southern California School of Medicine, Los Angeles 90033
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49
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Mönning U, König G, Banati R, Mechler H, Czech C, Gehrmann J, Schreiter-Gasser U, Masters C, Beyreuther K. Alzheimer beta A4-amyloid protein precursor in immunocompetent cells. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)35929-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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50
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Mizuguchi M, Ikeda K, Kim SU. Differential distribution of cellular forms of beta-amyloid precursor protein in murine glial cell cultures. Brain Res 1992; 584:219-25. [PMID: 1515940 DOI: 10.1016/0006-8993(92)90898-j] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The production and localization of cell-associated forms of beta-amyloid precursor protein (APP) of Alzheimer's disease was investigated in primary cultures of mouse glial cells. In both oligodendrocytes and astrocytes, immunofluorescence staining with an antibody against the carboxy terminus of APP revealed an intense cytoplasmic immunoreactivity. Immunoblotting of the cell extracts detected differences in the composition of APP between oligodendrocytes and astrocytes, notably the abundance of 107 kDa subtype in oligodendrocytes. Differences in immunoblot patterns were also noted between two buffer-insoluble, membrane-rich subcellular fractions of the glial cells, nuclear-mitochondrial and microsomal; the 119 kDa APP was enriched in the former, whereas the 73 and 115 kDa APPs in the latter. The results suggest that each APP subspecies may play a distinct functional role in different cell types and subcellular fractions.
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Affiliation(s)
- M Mizuguchi
- Department of Medicine, University of British Columbia, Vancouver, Canada
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