1
|
Saiyed N, Yilmaz A, Vishweswariah S, Maiti AK, Ustun I, Bartolone S, Brown-Hughes T, Thorpe RJ, Osentoski T, Ruff S, Pai A, Maddens M, Imam K, Graham SF. Urinary Cytokines as Potential Biomarkers of Mild Cognitive Impairment and Alzheimer's Disease: A Pilot Study. J Alzheimers Dis Rep 2023; 7:649-657. [PMID: 37483327 PMCID: PMC10357120 DOI: 10.3233/adr-220081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 05/13/2023] [Indexed: 07/25/2023] Open
Abstract
Background Alzheimer's disease (AD) is the most common form of dementia, accounting for 80% of all cases. Mild cognitive impairment (MCI) is a transitional state between normal aging and AD. Early detection is crucial, as irreversible brain damage occurs before symptoms manifest. Objective This study aimed to identify potential biomarkers for early detection of AD by analyzing urinary cytokine concentrations. We investigated 37 cytokines in AD, MCI, and cognitively normal individuals (NC), assessing their associations with AD development. Methods Urinary cytokine concentrations were measured in AD (n = 25), MCI (n = 25), and NC (n = 26) patients. IL6ST and MMP-2 levels were compared between AD and NC, while TNFRSF8, IL6ST, and IL-19 were assessed in AD versus MCI. Diagnostic models distinguished AD from NC, and in-silico analysis explored molecular mechanisms related to AD. Results Significant perturbations in IL6ST and MMP-2 concentrations were observed in AD urine compared to NC, suggesting their potential as biomarkers. TNFRSF8, IL6ST, and IL-19 differed significantly between AD and MCI, implicating them in disease progression. Diagnostic models exhibited promising performance (AUC: 0.59-0.79, sensitivity: 0.72-0.80, specificity: 0.56-0.78) in distinguishing AD from NC. In-silico analysis revealed molecular insights, including relevant non-coding RNAs, microRNAs, and transcription factors. Conclusion This study establishes significant associations between urinary cytokine concentrations and AD and MCI. IL6ST, MMP-2, TNFRSF8, IL6ST, and IL-19 emerge as potential biomarkers for early detection of AD. In-silico analysis enhances understanding of molecular mechanisms in AD. Further validation and exploration of these biomarkers in larger cohorts are warranted to assess their clinical utility.
Collapse
Affiliation(s)
- Nazia Saiyed
- Beaumont Research Institute, Metabolomics Department, Royal Oak, MI, USA
| | - Ali Yilmaz
- Beaumont Research Institute, Metabolomics Department, Royal Oak, MI, USA
- Oakland University-William Beaumont School of Medicine, Rochester, MI, USA
| | | | - Amit K. Maiti
- Department of Genetics and Genomics, Mydnavar, Southfield, MI, USA
| | - Ilyas Ustun
- College of Computing and Digital Media, DePaul University, Chicago, IL, USA
| | - Sarah Bartolone
- Department of Urology, Beaumont Research Institute, Royal Oak, MI, USA
| | | | - Roland J. Thorpe
- Department of Health, Behavior, and Society, Program for Research on Men’s Health, Hopkins Center for Health Disparities Solutions, Johns Hopkins Alzheimer’s Disease Resource Center for Minority Aging Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Tammy Osentoski
- Department of Alzheimer’s Research, Beaumont Health, Royal Oak, MI, USA
| | - Stacey Ruff
- Beaumont Health, Geriatric Medicine, Berkley, MI, USA
| | - Amita Pai
- Beaumont Health, Geriatric Medicine, Berkley, MI, USA
| | | | - Khaled Imam
- Beaumont Health, Geriatric Medicine, Berkley, MI, USA
| | - Stewart F. Graham
- Beaumont Research Institute, Metabolomics Department, Royal Oak, MI, USA
- Oakland University-William Beaumont School of Medicine, Rochester, MI, USA
| |
Collapse
|
2
|
Ou W, Ohno Y, Yang J, Chandrashekar DV, Abdullah T, Sun J, Murphy R, Roules C, Jagadeesan N, Cribbs DH, Sumbria RK. Efficacy and Safety of a Brain-Penetrant Biologic TNF-α Inhibitor in Aged APP/PS1 Mice. Pharmaceutics 2022; 14:2200. [PMID: 36297637 PMCID: PMC9612380 DOI: 10.3390/pharmaceutics14102200] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/04/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
Tumor necrosis factor alpha (TNF-α) plays a vital role in Alzheimer's disease (AD) pathology, and TNF-α inhibitors (TNFIs) modulate AD pathology. We fused the TNF-α receptor (TNFR), a biologic TNFI that sequesters TNF-α, to a transferrin receptor antibody (TfRMAb) to deliver the TNFI into the brain across the blood-brain barrier (BBB). TfRMAb-TNFR was protective in 6-month-old transgenic APP/PS1 mice in our previous work. However, the effects and safety following delayed chronic TfRMAb-TNFR treatment are unknown. Herein, we initiated the treatment when the male APP/PS1 mice were 10.7 months old (delayed treatment). Mice were injected intraperitoneally with saline, TfRMAb-TNFR, etanercept (non-BBB-penetrating TNFI), or TfRMAb for ten weeks. Biologic TNFIs did not alter hematology indices or tissue iron homeostasis; however, TfRMAb altered hematology indices, increased splenic iron transporter expression, and increased spleen and liver iron. TfRMAb-TNFR and etanercept reduced brain insoluble-amyloid beta (Aβ) 1-42, soluble-oligomeric Aβ, and microgliosis; however, only TfRMAb-TNFR reduced Aβ peptides, Thioflavin-S-positive Aβ plaques, and insoluble-oligomeric Aβ and increased plaque-associated phagocytic microglia. Accordingly, TfRMAb-TNFR improved spatial reference memory and increased BBB-tight junction protein expression, whereas etanercept did not. Overall, despite delayed treatment, TfRMAb-TNFR resulted in a better therapeutic response than etanercept without any TfRMAb-related hematology- or iron-dysregulation in aged APP/PS1 mice.
Collapse
Affiliation(s)
- Weijun Ou
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
| | - Yuu Ohno
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, 535 Watson Dr, Claremont, CA 91711, USA
| | - Joshua Yang
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, 535 Watson Dr, Claremont, CA 91711, USA
| | - Devaraj V. Chandrashekar
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
| | - Tamara Abdullah
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
| | - Jiahong Sun
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
| | - Riley Murphy
- Crean College of Health and Behavioral Sciences, Chapman University, Irvine, CA 92618, USA
| | - Chuli Roules
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
| | - Nataraj Jagadeesan
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
| | - David H. Cribbs
- MIND Institute, University of California, Irvine, CA 92697, USA
| | - Rachita K. Sumbria
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA 92618, USA
- Department of Neurology, University of California, Irvine, CA 92868, USA
| |
Collapse
|
3
|
Ou W, Yang J, Simanauskaite J, Choi M, Castellanos DM, Chang R, Sun J, Jagadeesan N, Parfitt KD, Cribbs DH, Sumbria RK. Biologic TNF-α inhibitors reduce microgliosis, neuronal loss, and tau phosphorylation in a transgenic mouse model of tauopathy. J Neuroinflammation 2021; 18:312. [PMID: 34972522 PMCID: PMC8719395 DOI: 10.1186/s12974-021-02332-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 11/26/2021] [Indexed: 12/23/2022] Open
Abstract
Background Tumor necrosis factor-α (TNF-α) plays a central role in Alzheimer’s disease (AD) pathology, making biologic TNF-α inhibitors (TNFIs), including etanercept, viable therapeutics for AD. The protective effects of biologic TNFIs on AD hallmark pathology (Aβ deposition and tau pathology) have been demonstrated. However, the effects of biologic TNFIs on Aβ-independent tau pathology have not been reported. Existing biologic TNFIs do not cross the blood–brain barrier (BBB), therefore we engineered a BBB-penetrating biologic TNFI by fusing the extracellular domain of the type-II human TNF-α receptor (TNFR) to a transferrin receptor antibody (TfRMAb) that ferries the TNFR into the brain via receptor-mediated transcytosis. The present study aimed to investigate the effects of TfRMAb-TNFR (BBB-penetrating TNFI) and etanercept (non-BBB-penetrating TNFI) in the PS19 transgenic mouse model of tauopathy. Methods Six-month-old male and female PS19 mice were injected intraperitoneally with saline (n = 12), TfRMAb-TNFR (1.75 mg/kg, n = 10) or etanercept (0.875 mg/kg, equimolar dose of TNFR, n = 10) 3 days/week for 8 weeks. Age-matched littermate wild-type mice served as additional controls. Blood was collected at baseline and 8 weeks for a complete blood count. Locomotion hyperactivity was assessed by the open-field paradigm. Brains were examined for phosphorylated tau lesions (Ser202, Thr205), microgliosis, and neuronal health. The plasma pharmacokinetics were evaluated following a single intraperitoneal injection of 0.875 mg/kg etanercept or 1.75 mg/kg TfRMAb-TNFR or 1.75 mg/kg chronic TfRMAb-TNFR dosing for 4 weeks. Results Etanercept significantly reduced phosphorylated tau and microgliosis in the PS19 mouse brains of both sexes, while TfRMAb-TNFR significantly reduced these parameters in the female PS19 mice. Both TfRMAb-TNFR and etanercept treatment improved neuronal health by significantly increasing PSD95 expression and attenuating hippocampal neuron loss in the PS19 mice. The locomotion hyperactivity in the male PS19 mice was suppressed by chronic etanercept treatment. Equimolar dosing resulted in eightfold lower plasma exposure of the TfRMAb-TNFR compared with etanercept. The hematological profiles remained largely stable following chronic biologic TNFI dosing except for a significant increase in platelets with etanercept. Conclusion Both TfRMAb-TNFR (BBB-penetrating) and non-BBB-penetrating (etanercept) biologic TNFIs showed therapeutic effects in the PS19 mouse model of tauopathy. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02332-7.
Collapse
Affiliation(s)
- Weijun Ou
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA, 92618, USA
| | - Joshua Yang
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | | | - Matthew Choi
- Keck Science Department, Claremont McKenna College, Claremont, CA, 91711, USA
| | - Demi M Castellanos
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | - Rudy Chang
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA, 92618, USA
| | - Jiahong Sun
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA, 92618, USA
| | - Nataraj Jagadeesan
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA, 92618, USA
| | - Karen D Parfitt
- Department of Neuroscience, Pomona College, Claremont, CA, 91711, USA
| | - David H Cribbs
- MIND Institute, University of California, Irvine, CA, 92697, USA
| | - Rachita K Sumbria
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, CA, 92618, USA. .,Department of Neurology, University of California, Irvine, CA, 92868, USA.
| |
Collapse
|
4
|
Babić Leko M, Nikolac Perković M, Klepac N, Štrac DŠ, Borovečki F, Pivac N, Hof PR, Šimić G. IL-1β, IL-6, IL-10, and TNFα Single Nucleotide Polymorphisms in Human Influence the Susceptibility to Alzheimer's Disease Pathology. J Alzheimers Dis 2021; 75:1029-1047. [PMID: 32390629 DOI: 10.3233/jad-200056] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Neuroinflammation plays an important role in Alzheimer's disease (AD). During this process, activated microglia release pro-inflammatory cytokines such as interleukin (IL)-1α, IL-1β, IL-6, and tumor necrosis factor α (TNFα) that participate in neuron damage, but also anti-inflammatory cytokines (such as IL-10), which maintain homeostasis of immune response. Previous studies showed the association of IL-1α -889C/T (rs1800587), IL-1β-1473G/C (rs1143623), IL-6 -174C/G (rs1800795), IL-10 -1082G/A (rs1800896), and TNFα -308A/G (rs1800629) polymorphisms with AD. OBJECTIVE We aimed to investigate whether people with certain IL-1α, IL-1β, IL-6, IL-10, and TNFα genotypes in these polymorphisms are more prone to develop AD-related pathology, reflected by pathological levels of cerebrospinal fluid (CSF) AD biomarkers including amyloid-β1-42, total tau (t-tau), tau phosphorylated at Thr 181 (p-tau181), Ser 199 (p-tau199), and Thr 231 (p-tau231), and visinin-like protein 1 (VILIP-1). METHODS The study included 115 AD patients, 53 patients with mild cognitive impairment, and 11 healthy controls. The polymorphisms were determined using real-time polymerase chain reaction. Levels of CSF biomarkers were determined by enzyme-linked immunosorbent assay. RESULTS A significant increase in p-tau CSF levels was found in patients with the AA IL-10 -1082G/A and GG TNFα -308A/G genotypes, and in carriers of a G allele in IL-1β -1473C/G and IL-6 -174C/G polymorphisms. t-tau levels were increased in carriers of a G allele in IL-1β -1473C/G polymorphism. An increase in VILIP-1 levels was observed in patients with CG and GG IL-1β -1473C/G, GC IL-6 -174C/G, and GG TNFα -308A/G genotype. CONCLUSION These results suggest that persons carrying certain genotypes in IL10 (-1082G/A), IL1β (1473C/G), IL6 (-174C/G), and TNFIα (-308A/G) could be more vulnerable to development of neuroinflammation, and consequently of AD.
Collapse
Affiliation(s)
- Mirjana Babić Leko
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb Medical School, Zagreb, Croatia
| | | | - Nataša Klepac
- Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia
| | | | - Fran Borovečki
- Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Nela Pivac
- Department of Molecular Medicine, Institute Ruđer Bošković, Zagreb, Croatia
| | - Patrick R Hof
- Nash Family Department of Neuroscience, Friedman Brain Institute, and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Goran Šimić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb Medical School, Zagreb, Croatia
| |
Collapse
|
5
|
Yuan J, Amin P, Ofengeim D. Necroptosis and RIPK1-mediated neuroinflammation in CNS diseases. Nat Rev Neurosci 2019; 20:19-33. [PMID: 30467385 DOI: 10.1038/s41583-018-0093-1] [Citation(s) in RCA: 539] [Impact Index Per Article: 107.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Apoptosis is crucial for the normal development of the nervous system, whereas neurons in the adult CNS are relatively resistant to this form of cell death. However, under pathological conditions, upregulation of death receptor family ligands, such as tumour necrosis factor (TNF), can sensitize cells in the CNS to apoptosis and a form of regulated necrotic cell death known as necroptosis that is mediated by receptor-interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like protein (MLKL). Necroptosis promotes further cell death and neuroinflammation in the pathogenesis of several neurodegenerative diseases, including multiple sclerosis, amyotrophic lateral sclerosis, Parkinson disease and Alzheimer disease. In this Review, we outline the evidence implicating necroptosis in these neurological diseases and suggest that targeting RIPK1 might help to inhibit multiple cell death pathways and ameliorate neuroinflammation.
Collapse
Affiliation(s)
- Junying Yuan
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
| | - Palak Amin
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | | |
Collapse
|
6
|
Martínez-Mármol R, Mohannak N, Qian L, Wang T, Gormal RS, Ruitenberg MJ, Vanhaesebroeck B, Coulson EJ, Meunier FA. p110δ PI3-Kinase Inhibition Perturbs APP and TNFα Trafficking, Reduces Plaque Burden, Dampens Neuroinflammation, and Prevents Cognitive Decline in an Alzheimer's Disease Mouse Model. J Neurosci 2019; 39:7976-7991. [PMID: 31363064 PMCID: PMC6774409 DOI: 10.1523/jneurosci.0674-19.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/26/2019] [Accepted: 07/22/2019] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is associated with the cleavage of the amyloid precursor protein (APP) to produce the toxic amyloid-β (Aβ) peptide. Accumulation of Aβ, together with the concomitant inflammatory response, ultimately leads to neuronal death and cognitive decline. Despite AD progression being underpinned by both neuronal and immunological components, therapeutic strategies based on dual targeting of these systems remains unexplored. Here, we report that inactivation of the p110δ isoform of phosphoinositide 3-kinase (PI3K) reduces anterograde axonal trafficking of APP in hippocampal neurons and dampens secretion of the inflammatory cytokine tumor necrosis factor-alpha by microglial cells in the familial AD APPswe/PS1ΔE9 (APP/PS1) mouse model. Moreover, APP/PS1 mice with kinase-inactive PI3Kδ (δD910A) had reduced Aβ peptides levels and plaques in the brain and an abrogated inflammatory response compared with APP/PS1 littermates. Mechanistic investigations reveal that PI3Kδ inhibition decreases the axonal transport of APP by eliciting the formation of highly elongated tubular-shaped APP-containing carriers, reducing the levels of secreted Aβ peptide. Importantly, APP/PS1/δD910A mice exhibited no spatial learning or memory deficits. Our data highlight inhibition of PI3Kδ as a new approach to protect against AD pathology due to its dual action of dampening microglial-dependent neuroinflammation and reducing plaque burden by inhibition of neuronal APP trafficking and processing.SIGNIFICANCE STATEMENT During Alzheimer's disease (AD), the accumulation of the toxic amyloid-β (Aβ) peptide in plaques is associated with a chronic excessive inflammatory response. Uncovering new drug targets that simultaneously reduce both Aβ plaque load and neuroinflammation holds therapeutic promise. Using a combination of genetic and pharmacological approaches, we found that the p110δ isoform of phosphoinositide 3-kinase (PI3K) is involved in anterograde trafficking of the amyloid precursor protein in neurons and in the secretion of tumor necrosis factor-alpha from microglial cells. Genetic inactivation of PI3Kδ reduces Aβ plaque deposition and abrogates the inflammatory response, resulting in a complete rescue of the life span and spatial memory performance. We conclude that inhibiting PI3Kδ represents a novel therapeutic approach to ameliorate AD pathology by dampening plaque accumulation and microglial-dependent neuroinflammation.
Collapse
Affiliation(s)
- Ramón Martínez-Mármol
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia
| | - Nika Mohannak
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia
| | - Lei Qian
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia, and
| | - Tong Wang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia
| | - Marc J Ruitenberg
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia, and
| | - Bart Vanhaesebroeck
- Cell Signalling, University College London Cancer Institute, London WC1E 6DD, United Kingdom
| | - Elizabeth J Coulson
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia,
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia, and
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia,
| |
Collapse
|
7
|
Sundermann EE, Hussain MA, Moore DJ, Horvath S, Lin DTS, Kobor MS, Levine A. Inflammation-related genes are associated with epigenetic aging in HIV. J Neurovirol 2019; 25:853-865. [PMID: 31286441 DOI: 10.1007/s13365-019-00777-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 06/11/2019] [Accepted: 06/18/2019] [Indexed: 12/14/2022]
Abstract
Chronic inflammation is characteristic of both HIV and aging ("inflammaging") and may contribute to the accelerated aging observed in people living with HIV (PLWH). We examined whether three inflammation-related single-nucleotide polymorphisms (SNPs) were risk factors for accelerated aging and HIV-associated, non-AIDS (HANA) conditions among PLWH. We examined 155 postmortem cases with HIV (mean age = 47.3, 81% male, 68% self-reported White) from the National NeuroAIDS Tissue Consortium who had pre-mortem neurobehavioral/medical/virologic data and epigenomic data from occipital cortex tissue. Accelerated aging was measured according to the Epigenetic Clock; an aging biomarker based on DNA methylation levels. Past or current age-associated HANA conditions including cerebrovascular, liver and kidney disease, chronic obstructive pulmonary disease, cancer, and diabetes were determined via self-report. Epigenetic Aging Z-scores and likelihood of past/current HANA conditions were compared between major allele homozygotes and minor allele carriers for each SNP (IL-6 - 174G>C, IL-10 - 592C>A, TNF-α - 308 G>A) separately. Analyses were adjusted for relevant demographic/clinical factors. Epigenetic aging (e.g., higher Z-scores) was significantly greater in IL-6 C allele carriers (p = .002) and IL-10 CC homozygotes (p = .02) compared to other genotype groups. The likelihood of any past/current HANA condition did not differ by IL-10 genotype but was 3.36 times greater in IL-6 C allele carriers versus others (OR = 3.36, 95%CI = 1.09-10.34, p = .03). TNF-α genotype was not associated with epigenetic aging or HANA conditions. IL-6 and IL-10 SNPs may help to identify PLWH who are at high risk for accelerated aging. These insights into pathophysiological pathways may inform interventional approaches to treat rapid aging among PLWH.
Collapse
Affiliation(s)
- Erin E Sundermann
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA.
| | - Mariam A Hussain
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA.,San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct, San Diego, CA, 92120, USA
| | - David J Moore
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Steven Horvath
- Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.,Biostatistics, School of Public Health, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - David T S Lin
- The Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, V5Z 4H4, Canada
| | - Michael S Kobor
- The Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, V5Z 4H4, Canada
| | - Andrew Levine
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | | |
Collapse
|
8
|
Abstract
RIPK1 kinase has emerged as a promising therapeutic target for the treatment of a wide range of human neurodegenerative, autoimmune, and inflammatory diseases. This was supported by extensive studies which demonstrated that RIPK1 is a key mediator of apoptotic and necrotic cell death as well as inflammatory pathways. Furthermore, human genetic evidence has linked the dysregulation of RIPK1 to the pathogenesis of ALS as well as other inflammatory and neurodegenerative diseases. Importantly, unique allosteric small-molecule inhibitors of RIPK1 that offer high selectivity have been developed. These molecules can penetrate the blood-brain barrier, thus offering the possibility to target neuroinflammation and cell death which drive various neurologic conditions including Alzheimer's disease, ALS, and multiple sclerosis as well as acute neurological diseases such as stroke and traumatic brain injuries. We discuss the current understanding of RIPK1 regulatory mechanisms and emerging evidence for the pathological roles of RIPK1 in human diseases, especially in the context of the central nervous systems.
Collapse
Affiliation(s)
- Alexei Degterev
- Department of Developmental, Molecular and Chemical Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02445
| | - Dimitry Ofengeim
- Rare and Neurologic Disease Research Therapeutic Area, Sanofi US, Framingham, MA 01701
| | - Junying Yuan
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| |
Collapse
|
9
|
Ortí-Casañ N, Wu Y, Naudé PJW, De Deyn PP, Zuhorn IS, Eisel ULM. Targeting TNFR2 as a Novel Therapeutic Strategy for Alzheimer's Disease. Front Neurosci 2019; 13:49. [PMID: 30778285 PMCID: PMC6369349 DOI: 10.3389/fnins.2019.00049] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/18/2019] [Indexed: 12/22/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia. Accumulating experimental evidence shows the important linkage between tumor necrosis factor-α (TNF) and AD, but the exact role of TNF in AD is still not completely understood. Although TNF-inhibitors are successfully used for treating several diseases, total inhibition of TNF can cause side effects, particularly in neurological diseases. This is attributed to the opposing roles of the two TNF receptors. TNF receptor 1 (TNFR1) predominantly mediates inflammatory and pro-apoptotic signaling pathways, whereas TNF receptor 2 (TNFR2) is neuroprotective and promotes tissue regeneration. Therefore, the specific activation of TNFR2 signaling, either by directly targeting TNFR2 via TNFR2 agonists or by blocking TNFR1 signaling with TNFR1-selective antagonists, seems a promising strategy for AD therapy. This mini-review discusses the involvement of TNFR2 and its signaling pathway in AD and outlines its potential application as therapeutic target. A better understanding of the function of TNFR2 may lead to the development of a treatment for AD.
Collapse
Affiliation(s)
- Natalia Ortí-Casañ
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, Groningen, Netherlands
| | - Yingying Wu
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, Groningen, Netherlands
| | - Petrus J W Naudé
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, Groningen, Netherlands.,Department of Neurology and Alzheimer Center, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Peter P De Deyn
- Department of Neurology and Alzheimer Center, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Inge S Zuhorn
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Ulrich L M Eisel
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, Groningen, Netherlands
| |
Collapse
|
10
|
Rea IM, Gibson DS, McGilligan V, McNerlan SE, Alexander HD, Ross OA. Age and Age-Related Diseases: Role of Inflammation Triggers and Cytokines. Front Immunol 2018; 9:586. [PMID: 29686666 PMCID: PMC5900450 DOI: 10.3389/fimmu.2018.00586] [Citation(s) in RCA: 707] [Impact Index Per Article: 117.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 03/08/2018] [Indexed: 12/11/2022] Open
Abstract
Cytokine dysregulation is believed to play a key role in the remodeling of the immune system at older age, with evidence pointing to an inability to fine-control systemic inflammation, which seems to be a marker of unsuccessful aging. This reshaping of cytokine expression pattern, with a progressive tendency toward a pro-inflammatory phenotype has been called "inflamm-aging." Despite research there is no clear understanding about the causes of "inflamm-aging" that underpin most major age-related diseases, including atherosclerosis, diabetes, Alzheimer's disease, rheumatoid arthritis, cancer, and aging itself. While inflammation is part of the normal repair response for healing, and essential in keeping us safe from bacterial and viral infections and noxious environmental agents, not all inflammation is good. When inflammation becomes prolonged and persists, it can become damaging and destructive. Several common molecular pathways have been identified that are associated with both aging and low-grade inflammation. The age-related change in redox balance, the increase in age-related senescent cells, the senescence-associated secretory phenotype (SASP) and the decline in effective autophagy that can trigger the inflammasome, suggest that it may be possible to delay age-related diseases and aging itself by suppressing pro-inflammatory molecular mechanisms or improving the timely resolution of inflammation. Conversely there may be learning from molecular or genetic pathways from long-lived cohorts who exemplify good quality aging. Here, we will discuss some of the current ideas and highlight molecular pathways that appear to contribute to the immune imbalance and the cytokine dysregulation, which is associated with "inflammageing" or parainflammation. Evidence of these findings will be drawn from research in cardiovascular disease, cancer, neurological inflammation and rheumatoid arthritis.
Collapse
Affiliation(s)
- Irene Maeve Rea
- School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, United Kingdom
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, University of Ulster, C-TRIC Building, Altnagelvin Area Hospital, Londonderry, United Kingdom
- Care of Elderly Medicine, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - David S. Gibson
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, University of Ulster, C-TRIC Building, Altnagelvin Area Hospital, Londonderry, United Kingdom
| | - Victoria McGilligan
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, University of Ulster, C-TRIC Building, Altnagelvin Area Hospital, Londonderry, United Kingdom
| | - Susan E. McNerlan
- Regional Genetics Service, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - H. Denis Alexander
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, University of Ulster, C-TRIC Building, Altnagelvin Area Hospital, Londonderry, United Kingdom
| | - Owen A. Ross
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, United States
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, United States
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| |
Collapse
|
11
|
Environmental Enrichment Potently Prevents Microglia-Mediated Neuroinflammation by Human Amyloid β-Protein Oligomers. J Neurosci 2017; 36:9041-56. [PMID: 27581448 DOI: 10.1523/jneurosci.1023-16.2016] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 07/06/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Microglial dysfunction is increasingly recognized as a key contributor to the pathogenesis of Alzheimer's disease (AD). Environmental enrichment (EE) is well documented to enhance neuronal form and function, but almost nothing is known about whether and how it alters the brain's innate immune system. Here we found that prolonged exposure of naive wild-type mice to EE significantly altered microglial density and branching complexity in the dentate gyrus of hippocampus. In wild-type mice injected intraventricularly with soluble Aβ oligomers (oAβ) from hAPP-expressing cultured cells, EE prevented several morphological features of microglial inflammation and consistently prevented oAβ-mediated mRNA changes in multiple inflammatory genes both in vivo and in primary microglia cultured from the mice. Microdialysis in behaving mice confirmed that EE normalized increases in the extracellular levels of the key cytokines (CCL3, CCL4, TNFα) identified by the mRNA analysis. Moreover, EE prevented the changes in microglial gene expression caused by ventricular injection of oAβ extracted directly from AD cerebral cortex. We conclude that EE potently alters the form and function of microglia in a way that prevents their inflammatory response to human oAβ, suggesting that prolonged environmental enrichment could protect against AD by modulating the brain's innate immune system. SIGNIFICANCE STATEMENT Environmental enrichment (EE) is a potential therapy to delay Alzheimer's disease (AD). Microglial inflammation is associated with the progression of AD, but the influence of EE on microglial inflammation is unclear. Here we systematically applied in vivo methods to show that EE alters microglia in the dentate gyrus under physiological conditions and robustly prevents microglial inflammation induced by human Aβ oligomers, as shown by neutralized microglial inflammatory morphology, mRNA changes, and brain interstitial fluid cytokine levels. Our findings suggest that EE alters the innate immune system and could serve as a therapeutic approach to AD and provide new targets for drug discovery. Further, we propose that the therapeutic benefits of EE could extend to other neurodegenerative diseases involving microglial inflammation.
Collapse
|
12
|
Emerging Link between Alzheimer's Disease and Homeostatic Synaptic Plasticity. Neural Plast 2016; 2016:7969272. [PMID: 27019755 PMCID: PMC4785275 DOI: 10.1155/2016/7969272] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/31/2016] [Indexed: 01/14/2023] Open
Abstract
Alzheimer's disease (AD) is an irreversible brain disorder characterized by progressive cognitive decline and neurodegeneration of brain regions that are crucial for learning and memory. Although intracellular neurofibrillary tangles and extracellular senile plaques, composed of insoluble amyloid-β (Aβ) peptides, have been the hallmarks of postmortem AD brains, memory impairment in early AD correlates better with pathological accumulation of soluble Aβ oligomers and persistent weakening of excitatory synaptic strength, which is demonstrated by inhibition of long-term potentiation, enhancement of long-term depression, and loss of synapses. However, current, approved interventions aiming to reduce Aβ levels have failed to retard disease progression; this has led to a pressing need to identify and target alternative pathogenic mechanisms of AD. Recently, it has been suggested that the disruption of Hebbian synaptic plasticity in AD is due to aberrant metaplasticity, which is a form of homeostatic plasticity that tunes the magnitude and direction of future synaptic plasticity based on previous neuronal or synaptic activity. This review examines emerging evidence for aberrant metaplasticity in AD. Putative mechanisms underlying aberrant metaplasticity in AD will also be discussed. We hope this review inspires future studies to test the extent to which these mechanisms contribute to the etiology of AD and offer therapeutic targets.
Collapse
|
13
|
Rezazadeh M, Khorrami A, Yeghaneh T, Talebi M, Kiani SJ, Heshmati Y, Gharesouran J. Genetic Factors Affecting Late-Onset Alzheimer's Disease Susceptibility. Neuromolecular Med 2015; 18:37-49. [PMID: 26553058 DOI: 10.1007/s12017-015-8376-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 10/19/2015] [Indexed: 11/29/2022]
Abstract
Alzheimer's disease is considered a progressive brain disease in the older population. Late-onset Alzheimer's disease (LOAD) as a multifactorial dementia has a polygenic inheritance. Age, environment, and lifestyle along with a growing number of genetic factors have been reported as risk factors for LOAD. Our aim was to present results of LOAD association studies that have been done in northwestern Iran, and we also explored possible interactions with apolipoprotein E (APOE) status. We re-evaluated the association of these markers in dominant, recessive, and additive models. In all, 160 LOAD and 163 healthy control subjects of Azeri Turkish ethnicity were studied. The Chi-square test with Yates' correction and Fisher's exact test were used for statistical analysis. A Bonferroni-corrected p value, based on the number of statistical tests, was considered significant. Our results confirmed that chemokine receptor type 2 (CCR2), estrogen receptor 1 (ESR1), toll-like receptor 2 (TLR2), tumor necrosis factor alpha (TNF α), APOE, bridging integrator 1 (BIN1), and phosphatidylinositol-binding clathrin assembly protein (PICALM) are LOAD susceptibility loci in Azeri Turk ancestry populations. Among them, variants of CCR2, ESR1, TNF α, and APOE revealed associations in three different genetic models. After adjusting for APOE, the association (both allelic and genotypic) with CCR2, BIN1, and ESRα (PvuII) was evident only among subjects without the APOE ε4, whereas the association with CCR5, without Bonferroni correction, was significant only among subjects carrying the APOE ε4 allele. This result is an evidence of a synergistic and antagonistic effect of APOE on variant associations with LOAD.
Collapse
Affiliation(s)
- Maryam Rezazadeh
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Aziz Khorrami
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Tarlan Yeghaneh
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahnaz Talebi
- Neuroscience Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Seyed Jalal Kiani
- Virology Department, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Yaser Heshmati
- Department of Medicine, Huddinge, H7, Karolinska Institutet, Stockholm, Sweden
| | - Jalal Gharesouran
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| |
Collapse
|
14
|
Wang T. TNF-alpha G308A polymorphism and the susceptibility to Alzheimer's disease: an updated meta-analysis. Arch Med Res 2015; 46:24-30.e1. [PMID: 25735998 DOI: 10.1016/j.arcmed.2014.12.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 12/18/2014] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIMS Tumor necrosis factor (TNF)-alpha G308A polymorphism has been reported in the association with susceptibility to Alzheimer's disease (AD); however, results have been contradictory. We conducted an updated meta-analysis to evaluate the role of TNF-alpha G308A in the occurrence of AD. METHODS Relevant articles were retrieved from online databases. The combined odds ratio, odds ratio in different genetic models, and the related 95% confidence intervals were calculated. Publication bias and homogeneity among individual studies were estimated. Subgroup analyses and sensitivity analyses were also performed. RESULTS In overall analyses, no risk of AD was associated with TNF-alpha G308A under different genetic models. However, in the subgroup analyses, a significant association between TNF-alpha G308A and AD risk was observed in Chinese. In addition, a significant protective effect of TNF-alpha -308A was found in the occurrence of AD among North European populations under a dominant model. CONCLUSIONS The result of this meta-analysis suggests that TNF-alpha G308A polymorphism may be associated with the increased risk of AD in Chinese and decreased risk of AD in northern European populations.
Collapse
Affiliation(s)
- Tengfei Wang
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee.
| |
Collapse
|
15
|
Gaur S, Agnihotri R. Alzheimer's disease and chronic periodontitis: is there an association? Geriatr Gerontol Int 2014; 15:391-404. [PMID: 25511390 DOI: 10.1111/ggi.12425] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2014] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease, an affliction of old age, is one of the leading causes for dementia worldwide. Various risk factors including family history, genetics and infections have been implicated in its pathogenesis. The cognitive decline in this condition is mainly a result of the formation of amyloid deposits that provoke neuroinflammation, ultimately resulting in cell death. Recently, an association between peripheral inflammation and Alzheimer's disease was hypothesized. It was suggested that chronic systemic inflammation worsened the inflammatory processes in the brain. This was mainly attributed to increased levels of pro-inflammatory mediators, such as interleukin-1, interleukin -6 and tumor necrosis factor-α in the plasma. As chronic periodontitis is a widespread peripheral immunoinflammatory condition, it has been proposed to play a significant role in the aggravation of Alzheimer's disease. With this background, the current review focuses on the relationship between Alzheimer's disease and chronic periodontitis, and its therapeutic implications.
Collapse
Affiliation(s)
- Sumit Gaur
- Department of Pedodontics and Preventive Dentistry, Manipal College of Dental Sciences, Manipal University, Manipal, Karnataka, India
| | | |
Collapse
|
16
|
Bhaskar K, Maphis N, Xu G, Varvel NH, Kokiko-Cochran ON, Weick JP, Staugaitis SM, Cardona A, Ransohoff RM, Herrup K, Lamb BT. Microglial derived tumor necrosis factor-α drives Alzheimer's disease-related neuronal cell cycle events. Neurobiol Dis 2013; 62:273-85. [PMID: 24141019 DOI: 10.1016/j.nbd.2013.10.007] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 10/01/2013] [Accepted: 10/06/2013] [Indexed: 01/06/2023] Open
Abstract
Massive neuronal loss is a key pathological hallmark of Alzheimer's disease (AD). However, the mechanisms are still unclear. Here we demonstrate that neuroinflammation, cell autonomous to microglia, is capable of inducing neuronal cell cycle events (CCEs), which are toxic for terminally differentiated neurons. First, oligomeric amyloid-beta peptide (AβO)-mediated microglial activation induced neuronal CCEs via the tumor-necrosis factor-α (TNFα) and the c-Jun Kinase (JNK) signaling pathway. Second, adoptive transfer of CD11b+ microglia from AD transgenic mice (R1.40) induced neuronal cyclin D1 expression via TNFα signaling pathway. Third, genetic deficiency of TNFα in R1.40 mice (R1.40-Tnfα(-/-)) failed to induce neuronal CCEs. Finally, the mitotically active neurons spatially co-exist with F4/80+ activated microglia in the human AD brain and that a portion of these neurons are apoptotic. Together our data suggest a cell-autonomous role of microglia, and identify TNFα as the responsible cytokine, in promoting neuronal CCEs in the pathogenesis of AD.
Collapse
Affiliation(s)
- Kiran Bhaskar
- Department of Molecular Genetics and Microbiology, University of New Mexico, MSC08 4660, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - Nicole Maphis
- Department of Molecular Genetics and Microbiology, University of New Mexico, MSC08 4660, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - Guixiang Xu
- Department of Neurosciences, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | - Nicholas H Varvel
- Department of Cellular Neurology, University of Tübingen, Hertie Institute for Clinical Brain Research, Otfried-Müller-Straße 27, 72076 Tübingen, Germany.
| | - Olga N Kokiko-Cochran
- Department of Neurosciences, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | - Jason P Weick
- Department of Neurosciences, University of New Mexico, MSC08 4740, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - Susan M Staugaitis
- Department of Neurosciences, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | - Astrid Cardona
- Department of Biology, University of Texas San Antonio, West Campus/Tobin lab MBT 1.216, San Antonio, TX 78249, USA.
| | - Richard M Ransohoff
- Department of Neurosciences, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | - Karl Herrup
- Department of Cell Biology and Neuroscience, Rutgers University, Nelson Hall, Busch Campus, Piscataway, NJ 08855, USA.
| | - Bruce T Lamb
- Department of Neurosciences, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| |
Collapse
|
17
|
Michaud M, Balardy L, Moulis G, Gaudin C, Peyrot C, Vellas B, Cesari M, Nourhashemi F. Proinflammatory cytokines, aging, and age-related diseases. J Am Med Dir Assoc 2013; 14:877-82. [PMID: 23792036 DOI: 10.1016/j.jamda.2013.05.009] [Citation(s) in RCA: 700] [Impact Index Per Article: 63.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 05/08/2013] [Indexed: 12/18/2022]
Abstract
Inflammation is a physiological process that repairs tissues in response to endogenous or exogenous aggressions. Nevertheless, a chronic state of inflammation may have detrimental consequences. Aging is associated with increased levels of circulating cytokines and proinflammatory markers. Aged-related changes in the immune system, known as immunosenescence, and increased secretion of cytokines by adipose tissue, represent the major causes of chronic inflammation. This phenomenon is known as "inflamm-aging." High levels of interleukin (IL)-6, IL-1, tumor necrosis factor-α, and C-reactive protein are associated in the older subject with increased risk of morbidity and mortality. In particular, cohort studies have indicated TNF-α and IL-6 levels as markers of frailty. The low-grade inflammation characterizing the aging process notably concurs at the pathophysiological mechanisms underlying sarcopenia. In addition, proinflammatory cytokines (through a variety of mechanisms, such as platelet activation and endothelial activation) may play a major role in the risk of cardiovascular events. Dysregulation of the inflammatory pathway may also affect the central nervous system and be involved in the pathophysiological mechanisms of neurodegenerative disorders (eg, Alzheimer disease).The aim of the present review was to summarize different targets of the activity of proinflammatory cytokines implicated in the risk of pathological aging.
Collapse
Affiliation(s)
- Martin Michaud
- Department of Geriatric Medicine, Gérontopôle de Toulouse, Toulouse University Hospital, Toulouse, France.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Montgomery SL, Narrow WC, Mastrangelo MA, Olschowka JA, O'Banion MK, Bowers WJ. Chronic neuron- and age-selective down-regulation of TNF receptor expression in triple-transgenic Alzheimer disease mice leads to significant modulation of amyloid- and Tau-related pathologies. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:2285-97. [PMID: 23567638 DOI: 10.1016/j.ajpath.2013.02.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/16/2013] [Accepted: 02/21/2013] [Indexed: 12/16/2022]
Abstract
Neuroinflammation, through production of proinflammatory molecules and activated glial cells, is implicated in Alzheimer's disease (AD) pathogenesis. One such proinflammatory mediator is tumor necrosis factor α (TNF-α), a multifunctional cytokine produced in excess and associated with amyloid β-driven inflammation and cognitive decline. Long-term global inhibition of TNF receptor type I (TNF-RI) and TNF-RII signaling without cell or stage specificity in triple-transgenic AD mice exacerbates hallmark amyloid and neurofibrillary tangle pathology. These observations revealed that long-term pan anti-TNF-α inhibition accelerates disease, cautions against long-term use of anti-TNF-α therapeutics for AD, and urges more selective regulation of TNF signaling. We used adeno-associated virus vector-delivered siRNAs to selectively knock down neuronal TNF-R signaling. We demonstrate divergent roles for neuronal TNF-RI and TNF-RII where loss of opposing TNF-RII leads to TNF-RI-mediated exacerbation of amyloid β and Tau pathology in aged triple-transgenic AD mice. Dampening of TNF-RII or TNF-RI+RII leads to a stage-independent increase in Iba-1-positive microglial staining, implying that neuronal TNF-RII may act nonautonomously on the microglial cell population. These results reveal that TNF-R signaling is complex, and it is unlikely that all cells and both receptors will respond positively to broad anti-TNF-α treatments at various stages of disease. In aggregate, these data further support the development of cell-, stage-, and/or receptor-specific anti-TNF-α therapeutics for AD.
Collapse
MESH Headings
- Adenoviridae/genetics
- Aging/metabolism
- Alzheimer Disease/genetics
- Alzheimer Disease/metabolism
- Alzheimer Disease/pathology
- Amyloid beta-Peptides/metabolism
- Animals
- Brain/pathology
- Disease Progression
- Down-Regulation/physiology
- Gene Knockdown Techniques
- Genetic Vectors
- Male
- Mice
- Mice, Transgenic
- Microglia/metabolism
- Neurons/metabolism
- Plaque, Amyloid/metabolism
- RNA, Small Interfering/genetics
- Receptors, Tumor Necrosis Factor/biosynthesis
- Receptors, Tumor Necrosis Factor/deficiency
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor, Type I/biosynthesis
- Receptors, Tumor Necrosis Factor, Type I/deficiency
- Receptors, Tumor Necrosis Factor, Type I/genetics
- Receptors, Tumor Necrosis Factor, Type II/biosynthesis
- Receptors, Tumor Necrosis Factor, Type II/deficiency
- Receptors, Tumor Necrosis Factor, Type II/genetics
- Signal Transduction/physiology
Collapse
Affiliation(s)
- Sara L Montgomery
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York 14642, USA
| | | | | | | | | | | |
Collapse
|
19
|
Abstract
Alzheimer's disease (AD) is the most common cause of dementia in the elderly, and is typically characterized by memory loss. In addition, during the disease progression, most patients develop behavioural and psychiatric symptoms of dementia (BPSD). Frontotemporal Lobar Degeneration (FTLD) is the most frequent neurodegenerative disorder with a presenile onset. It is characterized mainly by behavioural disturbances, whereas memory is conserved. The two major neuropathologic hallmarks of AD are extracellular Amyloid beta (Ab) plaques and intracellular neurofibrillary tangles (NFTs). Conversely, in FTLD the deposition of tau has been observed in a number of cases, but in several brains there is no deposition of tau but instead a positivity for ubiquitin. In some families these diseases are inherited in an autosomal dominant fashion. Genes responsible for familial AD include the Amyloid Precursor Protein (b-APP), Presenilin 1 (PS1)and Presenilin 2 (PS2). The majority of mutations in these genes are often associated with a very early onset (40–50 years of age). Regarding FTLD, the first mutations described are located in the Microtubule Associated Protein Tau gene(MAPT). Tau is a component of microtubules, which represent the internal support structures for the transport of nutrients, vesicles, mitochondria and chromosomes within the cell. Mutations in MAPT are associated with an early onset of the disease (40–50 years), and the clinical phenotype is consistent with Frontotemporal Dementia (FTD). Recently, mutations in a second gene, named progranulin(GRN), have been identified in some families with FTLD. The pathology associated with these mutations is most frequently characterized by the immunostaining of TAR DNA Binding Protein 43 (TDP-43), which is a transcription factor. The clinical phenotype associated with GRN mutations is highly heterogeneous,including FTD, Progressive Aphasia, Corticobasal Syndrome, and AD. Age at disease onset is variable, ranging from 45 to 85 years of age. The majority of cases of AD and FTLD are however sporadic, and likely several genetic and environmental factors contribute to their development. Concerning AD, it is known that the presence of the e4 allele of the Apolipoprotein E gene is a susceptibility factor,increasing the risk of about 4 fold. A number of additional genetic factors,including cytokines, chemokines, Nitric Oxide Synthases, contribute to the susceptibility for the disease. Some of them also influence the risk to develop FTLD.Variability in serotonin transporter gene could influence the development of BPSD. In this chapter, current knowledge on molecular mechanisms at the basis of AD and FTLD, as well as the role of genetics, will be presented and discussed.
Collapse
|
20
|
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.
Collapse
|
21
|
Ma SL, Lam LCW. Panel of Genetic Variations as a Potential Non-invasive Biomarker for Early Diagnosis of Alzheimer's Disease. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2011; 9:54-66. [PMID: 23429712 PMCID: PMC3569084 DOI: 10.9758/cpn.2011.9.2.54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/06/2011] [Accepted: 05/23/2011] [Indexed: 01/05/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia. Biomarkers such as levels of amyloid beta (Aβ) in cerebrospinal fluid and ApoE genotyping were suggested for the diagnosis of AD, however, the result is either non-conclusive or with invasive procedure. Genome-wide association studies (GWASs) for AD suggested single nucleotide polymorphisms (SNPs) in many genes are associated with the risk of AD, but each only contributed with small effect to the disease. By incorporating a panel of established genetic susceptibility factors, the risk of an individual in getting AD could be better estimated. Further research will be required to reveal if adding to the current well-developed clinical diagnosis protocol, the accuracy and specificity of diagnosis of AD would be greatly improved and if this might also be beneficial in identifying pre-symptomatic AD patients for early diagnosis and intervention of the disease.
Collapse
Affiliation(s)
- Suk Ling Ma
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA. ; Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | | |
Collapse
|
22
|
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.
Collapse
Affiliation(s)
- Judith Miklossy
- International Alzheimer Research Center, Prevention Alzheimer Foundation, Martigny-Combe, Switzerland.
| |
Collapse
|
23
|
Janelsins MC, Kohli S, Mohile SG, Usuki K, Ahles TA, Morrow GR. An update on cancer- and chemotherapy-related cognitive dysfunction: current status. Semin Oncol 2011; 38:431-8. [PMID: 21600374 DOI: 10.1053/j.seminoncol.2011.03.014] [Citation(s) in RCA: 218] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of this review is to summarize the current literature on the effects of cancer treatment-related cognitive difficulties, with a focus on the effects of chemotherapy. Numerous patients have cognitive difficulties during and after cancer treatments and, for some, these effects last years after treatment. We do not yet fully understand which factors increase susceptibility to cognitive difficulties during treatment and which cause persistent problems. We review possible contributors, including genetic and biological factors. Mostly we focus is on cognitive effects of adjuvant chemotherapy for breast cancer; however, cognitive effects of chemotherapy on the elderly and brain tumor patients are also discussed.
Collapse
Affiliation(s)
- Michelle C Janelsins
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | | | | | | | | | | |
Collapse
|
24
|
Montgomery SL, Bowers WJ. Tumor necrosis factor-alpha and the roles it plays in homeostatic and degenerative processes within the central nervous system. J Neuroimmune Pharmacol 2011; 7:42-59. [PMID: 21728035 DOI: 10.1007/s11481-011-9287-2] [Citation(s) in RCA: 242] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 06/20/2011] [Indexed: 12/12/2022]
Abstract
Tumor Necrosis Factor-alpha (TNF-α) is a prototypic pro-inflammatory cytokine involved in the innate immune response. TNF-α ligation and downstream signaling with one of its cognate receptors, TNF-RI or TNF-RII, modulates fundamental processes in the brain including synapse formation and regulation, neurogenesis, regeneration, and general maintenance of the central nervous system (CNS). During states of chronic neuroinflammation, extensive experimental evidence implicates TNF-α as a key mediator in disease progression, gliosis, demyelination, inflammation, blood-brain-barrier deterioration, and cell death. This review explores the complex roles of TNF-α in the CNS under normal physiologic conditions and during neurodegeneration. We focus our discussion on Multiple Sclerosis, Parkinson's disease, and Alzheimer's disease, relaying the outcomes of preclinical and clinical testing of TNF-α directed therapeutic strategies, and arguing that despite the wealth of functions attributed to this central cytokine, surprisingly little is known about the cell type- and stage-specific roles of TNF-α in these debilitating disorders.
Collapse
Affiliation(s)
- Sara L Montgomery
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | | |
Collapse
|
25
|
Chakrabarty P, Herring A, Ceballos-Diaz C, Das P, Golde TE. Hippocampal expression of murine TNFα results in attenuation of amyloid deposition in vivo. Mol Neurodegener 2011; 6:16. [PMID: 21324189 PMCID: PMC3050766 DOI: 10.1186/1750-1326-6-16] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 02/16/2011] [Indexed: 12/01/2022] Open
Abstract
Fibrillar amyloid β (fAβ) peptide is the major component of Aβ plaques in the brains of Alzheimer's disease (AD) patients. Inflammatory mediators have previously been proposed to be drivers of Aβ pathology in AD patients by increasing amyloidogenic processing of APP and promoting Aβ accumulation, but recent data have shown that expression of various inflammatory cytokines attenuates Aβ pathology in mouse models. In an effort to further study the role of different inflammatory cytokines on Aβ pathology in vivo, we explored the effect of murine Tumor Necrosis Factor α (mTNFα) in regulating Aβ accumulation. Recombinant adeno-associated virus serotype 1 (AAV2/1) mediated expression of mTNFα in the hippocampus of 4 month old APP transgenic TgCRND8 mice resulted in significant reduction in hippocampal Aβ burden. No changes in APP levels or APP processing were observed in either mTNFα expressing APP transgenic mice or in non-transgenic littermates. Analysis of Aβ plaque burden in mTNFα expressing mice showed that even after substantial reduction compared to EGFP expressing age-matched controls, the Aβ plaque burden levels of the former do not decrease to the levels of 4 month old unmanipulated mice. Taken together, our data suggests that proinflammatory cytokine expression induced robust glial activation can attenuate plaque deposition. Whether such an enhanced microglial response actually clears preexisting deposits without causing bystander neurotoxicity remains an open question.
Collapse
Affiliation(s)
- Paramita Chakrabarty
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, 1275 Center Drive, Gainesville, PO Box #100159, FL-32610, USA.
| | | | | | | | | |
Collapse
|
26
|
Wu X, Lu Y, Dong Y, Zhang G, Zhang Y, Xu Z, Culley DJ, Crosby G, Marcantonio ER, Tanzi RE, Xie Z. The inhalation anesthetic isoflurane increases levels of proinflammatory TNF-α, IL-6, and IL-1β. Neurobiol Aging 2010; 33:1364-78. [PMID: 21190757 DOI: 10.1016/j.neurobiolaging.2010.11.002] [Citation(s) in RCA: 197] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 10/29/2010] [Accepted: 11/02/2010] [Indexed: 11/19/2022]
Abstract
Anesthetics have been reported to promote Alzheimer's disease (AD) neuropathogenesis by inducing β-amyloid protein accumulation and apoptosis. Neuroinflammation is associated with the emergence of AD. We therefore set out to determine the effects of the common anesthetic isoflurane on the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, the proinflammatory cytokines, in vitro and in vivo, employing Western blot, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and reverse transcriptase polymerase chain reaction (RT-PCR). Here, we show that a clinically relevant isoflurane anesthesia increased the protein and messenger ribonucleic acid (mRNA) levels of TNF-α, IL-6, and IL-1β in the brain tissues of mice. The isoflurane anesthesia increased the amounts of TNF-α immunostaining positive cells in the brain tissues of mice, the majority of which were neurons. Furthermore, isoflurane increased TNF-α levels in primary neurons, but not microglia cells, of mice. Finally, isoflurane induced a greater degree of TNF-α increase in the AD transgenic mice than in the wild-type mice. These results suggest that isoflurane may increase the levels of proinflammatory cytokines, which may cause neuroinflammation, leading to promotion of AD neuropathogenesis.
Collapse
Affiliation(s)
- Xu Wu
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129-2060, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Hensley K. Neuroinflammation in Alzheimer's disease: mechanisms, pathologic consequences, and potential for therapeutic manipulation. J Alzheimers Dis 2010; 21:1-14. [PMID: 20182045 DOI: 10.3233/jad-2010-1414] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The concept of neuroinflammation has evolved over the past two decades from an initially controversial viewpoint to its present status as a generally accepted idea whose mechanisms and consequences are still actively under research and debate, particularly with regard to Alzheimer's disease (AD). This review summarizes the current status of neuroinflammation research as it specifically relates to AD. Neuroinflammation is discussed mechanistically with emphasis on the role of redox signal transduction linked to the activation of central nervous system-relevant innate immune pathways. Redox signaling is presented both as a causal factor and a consequence of sustained neuroinflammation. Functional relationships are discussed that connect distinct neuroinflammatory components such as cytokines, eicosanoids, classic AD pathology (amyloid plaques and neurofibrillary tangles), and the recently emergent notion of "damage-associated molecular patterns". The interaction of these paracrine factors likely can produce positive as well as negative effects on the AD brain, ranging from plaque clearance by microglia in the short term to glial dysfunction and neuronal compromise if the neuroinflammation is chronically sustained and unmitigated. Recent disappointments in AD clinical trials of anti-inflammatory drugs are discussed with reference to possible explanations and potential avenues for future pharmacological approaches to the disease.
Collapse
Affiliation(s)
- Kenneth Hensley
- Department of Pathology, University of Toledo Health Sciences Center, Toledo, OH 43614-2598, USA.
| |
Collapse
|
28
|
Cercy SP, Bronson B. Putative mechanisms of cognitive dysfunction in chemotherapy-naïve diffuse large B-cell lymphoma: a case report and review of the literature. ACTA ACUST UNITED AC 2010; 17:223-33. [PMID: 20799114 DOI: 10.1080/09084282.2010.499809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cognitive impairment is now recognized as a frequent consequence of treatments for cancers localized outside the central nervous system (CNS). In contrast, little attention has been given to the potentially deleterious cognitive effects from non-CNS cancers themselves. The present case study proposes that cognitive deficits occur in a subset of treatment-naive patients with diffuse large B-cell lymphoma in whom no gross evidence of lymphoma-related CNS involvement is apparent. Evidence is presented from a case study and elaborate putative mechanisms centering on deleterious effects of B-cell-mediated inflammatory cytokine secretion on neurons. Moreover, this case study speculates that genetic variability involving apolipoprotein E or other factors may mediate cognitive variability among these patients.
Collapse
Affiliation(s)
- Steven P Cercy
- Mental Health Service, Veterans Affairs New York Harbor Healthcare System, 423 East 23rd Street, New York, NY 10010, USA.
| | | |
Collapse
|
29
|
Njie EG, Boelen E, Stassen FR, Steinbusch HWM, Borchelt DR, Streit WJ. Ex vivo cultures of microglia from young and aged rodent brain reveal age-related changes in microglial function. Neurobiol Aging 2010; 33:195.e1-12. [PMID: 20580465 DOI: 10.1016/j.neurobiolaging.2010.05.008] [Citation(s) in RCA: 226] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 05/01/2010] [Accepted: 05/10/2010] [Indexed: 11/26/2022]
Abstract
To understand how microglial cell function may change with aging, various protocols have been developed to isolate microglia from the young and aged central nervous system (CNS). Here we report modification of an existing protocol that is marked by less debris contamination and improved yields and demonstrate that microglial functions are varied and dependent on age. Specifically, we found that microglia from aged mice constitutively secrete greater amounts of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) relative to microglia from younger mice and are less responsive to stimulation. Also, microglia from aged mice have reduced glutathione levels and internalize less amyloid beta peptide (Aβ) while microglia from mice of all ages do not retain the amyloid beta peptide for a significant length of time. These studies offer further support for the idea that microglial cell function changes with aging. They suggest that microglial Aβ phagocytosis results in Aβ redistribution rather than biophysical degradation in vivo and thereby provide mechanistic insight to the lack of amyloid burden elimination by parenchymal microglia in aged adults and those suffering from Alzheimer's disease.
Collapse
Affiliation(s)
- Emalick G Njie
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610-0244, United States.
| | | | | | | | | | | |
Collapse
|
30
|
Olgiati P, Politis A, Malitas P, Albani D, Dusi S, Polito L, De Mauro S, Zisaki A, Piperi C, Stamouli E, Mailis A, Batelli S, Forloni G, De Ronchi D, Kalofoutis A, Liappas I, Serretti A. APOE epsilon-4 allele and cytokine production in Alzheimer's disease. Int J Geriatr Psychiatry 2010; 25:338-44. [PMID: 19618379 DOI: 10.1002/gps.2344] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE The APOE epsilon-4 allele has consistently emerged as a susceptibility factor for Alzheimer's disease (AD). Pro-inflammatory cytokines are detectable at abnormal levels in AD, and are thought to play a pathophysiological role. Animal studies have shown dose-dependent correlations between the number of APOE epsilon-4 alleles and the levels of pro-inflammatory cytokines. The aims of this study were to investigate the influence of APOE genotypes on TNF-alpha, IL-6, and IL-1beta secreted by peripheral blood mononuclear cells (PBMC) from human patients with AD and to analyze the correlation between cytokine production and AD clinical features. METHODS Outpatients with AD (n = 40) were clinically evaluated for cognitive decline (MMSE) and psychiatric symptoms (Cornell Scale for Depression in Dementia; Neuropsychiatric Inventory) and genotyped for APOE variants. PBMCs were isolated from the donors and used to assess spontaneous and PMA-stimulated secretion of TNF-alpha, IL-6, and IL-1beta. Cytokine production was determined by immuno-enzymatic assays (ELISA). RESULTS In comparison with their counterparts without APOE4, patients with at least one copy of the APOE epsilon-4 allele showed higher spontaneous (p = 0.037) and PMA-induced (p = 0.039) production of IL-1beta after controlling for clinical variables. Significant correlations were reported between NPI scores (psychotic symptoms) and IL-6 production. CONCLUSION These preliminary findings suggest the involvement of inflammatory response in the pathogenic effect of the APOE epsilon-4 allele in AD, although their replication in larger samples is mandatory. The modest correlations between pro-inflammatory cytokines released at peripheral level and AD features emphasizes the need for further research to elucidate the role of neuroinflammation in pathophysiology of AD.
Collapse
Affiliation(s)
- Paolo Olgiati
- Institute of Psychiatry, University of Bologna, Bologna, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Johnstone D, Milward EA. Molecular genetic approaches to understanding the roles and regulation of iron in brain health and disease. J Neurochem 2010; 113:1387-402. [PMID: 20345752 DOI: 10.1111/j.1471-4159.2010.06697.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Iron is essential in the brain, yet too much iron can be toxic. Tight regulation of iron in the brain may involve intrinsic mechanisms that control internal homeostasis independent of systemic iron status. Iron abnormalities occur in various neurological disorders, usually with symptoms or neuropathology associated with movement impairment or behavioral disturbances rather than cognitive impairment or dementia. Consistent with this, polymorphisms in the HFE gene, associated with the iron overload disorder hemochromatosis, show stronger associations with the movement disorder amyotrophic lateral sclerosis (motor neuron disease) than with cognitive impairment. Such associations may arise because certain brain regions involved in movement or executive control are particularly iron-rich, notably the basal ganglia, and may be highly reliant on iron. Various mechanisms, including iron redistribution causing functional iron deficiency, lysosomal and mitochondrial abnormalities or oxidative damage, could underlie iron-related neuropathogenesis. Clarifying how iron contributes causatively to neurodegeneration may improve treatment options in a range of neurodegenerative disorders. This review considers how modern molecular genetic approaches can be applied to resolve the complex molecular systems and pathways by which brain iron homeostasis is regulated and the molecular changes that occur with iron dyshomeostasis and neuropathogenesis.
Collapse
Affiliation(s)
- Daniel Johnstone
- School of Biomedical Sciences and Pharmacy and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia
| | | |
Collapse
|
32
|
Dato S, Krabbe KS, Thinggaard M, Pedersen BK, Christensen K, Bruunsgaard H, Christiansen L. Commonly studied polymorphisms in inflammatory cytokine genes show only minor effects on mortality and related risk factors in nonagenarians. J Gerontol A Biol Sci Med Sci 2010; 65:225-35. [PMID: 20083555 DOI: 10.1093/gerona/glp210] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Systemic low-grade inflammation is consistently associated with functional status, cognitive functioning, multimorbidity, and survival in oldest olds. If inflammation is either a cause or a consequence of age-related pathology, genetic determinants of late-life survival can reside in cytokine genes polymorphisms, regulating inflammatory responses. The aim of this study was to test associations between commonly studied polymorphisms in interleukin (IL)6, IL10, IL15, and IL18, and tumor necrosis factor-alpha genes and late-life survival in a longitudinal cohort of nonagenarians: the Danish 1905 cohort. Additionally, associations were investigated between inflammatory markers and major predictors of mortality as cognitive and functional status. Modest sex-specific associations were found with survival, cognitive functioning, and handgrip strength. Evaluation of combined genotypes indicated that, in nonagenarian men, the balance of pro- and anti-inflammatory activity at IL18 and IL10 loci is protective against cognitive decline. In conclusion, in this large study with virtually complete follow-up, commonly studied polymorphisms in cytokine genes do not have a major impact on late-life survival or associated risk phenotypes.
Collapse
Affiliation(s)
- Serena Dato
- The Danish Aging Research Center, Epidemiology Unit, Institute of Public Health, University of Southern Denmark, J.B. Winsløws Vej 9, DK-5000 Odense, Denmark.
| | | | | | | | | | | | | |
Collapse
|
33
|
Systematic review by meta-analyses on the possible role of TNF-alpha polymorphisms in association with Alzheimer's disease. ACTA ACUST UNITED AC 2009; 61:60-8. [PMID: 19445962 DOI: 10.1016/j.brainresrev.2009.05.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 04/30/2009] [Accepted: 05/02/2009] [Indexed: 12/18/2022]
Abstract
It has been hypothesized that polymorphisms of Tumor Necrosis Factor (TNF)-alpha gene affect the risk of developing Alzheimer's disease (AD). However, results of different studies are often inconsistent. Our aim was to investigate by meta-analysis the association of the common polymorphisms comprehensively defining the genetic variability of the TNF-alpha gene with AD risk. Hence, the results being stated are of a meta-analysis across studies, and that this meta-analysis does not invalidate the results of the individual studies previously performed. Seventeen studies that investigated the association between 5 TNF-alpha polymorphisms (-850, -308, -863, -238, and -1031) and AD were retrieved and analyzed. The model-free approach was applied to meta-analyze these case-control genetic association studies. Available data suggested a significant association between -850 polymorphism and AD risk (TT vs. TC+CC: pooled odds ratio [OR], 1.61; 95% confidence interval [CI], 1.08-2.29; p=0.02) with no evidence of between-study heterogeneity (chi(2), p>0.1). Subgroup analysis suggested that the possession of T allele significantly increased the risk of AD associated with carriage of the apolipoprotein E epsilon 4 allele in Caucasian Australians and Northern Europeans (TT+TC vs. CC: OR, 1.95; 95% CI, 1.45-2.62; p=0.00001; p>0.1; chi(2) for heterogeneity, p>0.1). No significant difference in genotype distribution of -308 polymorphism in AD was found, with a high degree of between-study heterogeneity. For the -863 and -1031 polymorphisms we did not find an association with AD, but significant between-study heterogeneity discouraged genotype data pooling. Only four studies investigated the -238 variant and the results were not significant. Current findings support an association between -850 C>T polymorphism and the risk of developing AD; hence, they strengthen the suggestion of a potential role for anti-TNF therapy to maintain physiologic levels of TNF-alpha.
Collapse
|
34
|
McAlpine FE, Lee JK, Harms AS, Ruhn KA, Blurton-Jones M, Hong J, Das P, Golde TE, LaFerla FM, Oddo S, Blesch A, Tansey MG. Inhibition of soluble TNF signaling in a mouse model of Alzheimer's disease prevents pre-plaque amyloid-associated neuropathology. Neurobiol Dis 2009; 34:163-77. [PMID: 19320056 DOI: 10.1016/j.nbd.2009.01.006] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Microglial activation and overproduction of inflammatory mediators in the central nervous system (CNS) have been implicated in Alzheimer's disease (AD). Elevated levels of the pro-inflammatory cytokine tumor necrosis factor (TNF) have been reported in serum and post-mortem brains of patients with AD, but its role in progression of AD is unclear. Using novel engineered dominant negative TNF inhibitors (DN-TNFs) selective for soluble TNF (solTNF), we investigated whether blocking TNF signaling with chronic infusion of the recombinant DN-TNF XENP345 or a single injection of a lentivirus encoding DN-TNF prevented the acceleration of AD-like pathology induced by chronic systemic inflammation in 3xTgAD mice. We found that chronic inhibition of solTNF signaling with either approach decreased the LPS-induced accumulation of 6E10-immunoreactive protein in hippocampus, cortex, and amygdala. Immunohistological and biochemical approaches using a C-terminal APP antibody indicated that a major fraction of the accumulated protein was likely to be C-terminal APP fragments (beta-CTF) while a minor fraction consisted of Av40 and 42. Genetic inactivation of TNFR1-mediated TNF signaling in 3xTgAD mice yielded similar results. Taken together, our studies indicate that soluble TNF is a critical mediator of the effects of neuroinflammation on early (pre-plaque) pathology in 3xTgAD mice. Targeted inhibition of solTNF in the CNS may slow the appearance of amyloid-associated pathology, cognitive deficits, and potentially the progressive loss of neurons in AD.
Collapse
Affiliation(s)
- Fiona E McAlpine
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9040, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Effects of TNFalpha-converting enzyme inhibition on amyloid beta production and APP processing in vitro and in vivo. J Neurosci 2009; 28:12052-61. [PMID: 19005070 DOI: 10.1523/jneurosci.2913-08.2008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Tumor necrosis factor-alpha (TNFalpha) is a proinflammatory cytokine that is elevated in Alzheimer's disease (AD) brains. Because TNFalpha is released from cell membranes by the TNFalpha-converting enzyme (TACE), inhibition of TACE has the potential to mitigate TNFalpha effects in AD brain. TACE also cleaves amyloid precursor protein (APP) and generates sAPPalpha, precluding the formation of potentially harmful amyloid beta (Abeta) peptides by beta-site APP cleaving enzymes (BACE). Hence, the anti-inflammatory benefits of TACE inhibition might be offset by an increase in Abeta. We have examined the effects of the highly selective TACE inhibitor, BMS-561392, on APP processing in vitro and in vivo. In Chinese hamster ovary cells expressing APP, BMS-561392 significantly reduced secretion of sAPPalpha without a corresponding increase in Abeta production. Conversely, a BACE inhibitor decreased sAPPbeta and Abeta peptides with no change in the secretion of sAPPalpha. These data indicate an absence of TACE and BACE competition for the APP substrate. Despite this, we observed competition for APP when TACE activity was enhanced via phorbol ester treatment or if APP was modified such that it was retained within the trans-Golgi network (TGN). These results suggest that BACE and TACE share a common TGN localization, but under normal conditions do not compete for APP. To confirm this finding in vivo, BMS-561392 was infused into the brains of Tg2576 and wild-type mice. Although decreased brain sAPPalpha levels were observed, steady-state Abeta levels were not significantly changed. Accordingly, it is possible that TACE inhibitors could reduce TNFalpha levels without increasing Abeta levels within the AD brain.
Collapse
|
36
|
McAlpine FE, Tansey MG. Neuroinflammation and tumor necrosis factor signaling in the pathophysiology of Alzheimer's disease. J Inflamm Res 2008; 1:29-39. [PMID: 22096345 PMCID: PMC3218716 DOI: 10.2147/jir.s4397] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects nearly one in two individuals over 90 years of age. Its neuropathological hallmarks are accumulation of extraneuronal plaques of amyloid-beta (Aβ), the presence of neurofibrillary tangles formed by aberrantly hyperphosphorylated tau, progressive synaptic loss, and neurodegeneration which eventually results in decline of memory and cognitive faculties. Although the etiology of sporadic AD in humans is unknown, mutations in amyloid precursor protein or components of its processing machinery (β-secretase and γ-secretase) result in overproduction of Aβ1-40 and 1-42 peptides and are sufficient to cause disease. In this review, we highlight the experimental and clinical evidence that suggests a close association between neuro-inflammation and AD pathogenesis. Overproduction of inflammatory mediators in the brain occurs when microglia, which are often found in close physical association with amyloid plaques in AD brains, become chronically activated. It has been proposed that elevated levels of pro-inflammatory cytokines, including tumor necrosis factor (TNF), may inhibit phagocytosis of Aβ in AD brains thereby hindering efficient plaque removal by resident microglia. In support of this idea, the bacterial endotoxin lipopolysaccharide, a potent trigger of inflammation that elicits production of TNF and many other cytokines, can accelerate the appearance and severity of AD pathology in several animal models of AD. We review the evidence implicating TNF signaling in AD pathology and discuss how TNF-dependent processes may contribute to cognitive dysfunction and accelerated progression of AD. We conclude by reviewing the observations that provide compelling rationale to investigate the extent to which new therapeutic approaches that selectively target the TNF pathway modify progression of neuropathology in pre-clinical models of AD as well as the promising findings with the use of nonsteroidal anti-inflammatory drugs and recent clinical trials with Aβ immunotherapy.
Collapse
Affiliation(s)
| | - Malú G Tansey
- Correspondence: Malú G Tansey, Department of Physiology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA, Tel +1 214 645 6037, Fax +1 214 645 6049, Email
| |
Collapse
|
37
|
McCoy MK, Tansey MG. TNF signaling inhibition in the CNS: implications for normal brain function and neurodegenerative disease. J Neuroinflammation 2008; 5:45. [PMID: 18925972 PMCID: PMC2577641 DOI: 10.1186/1742-2094-5-45] [Citation(s) in RCA: 624] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Accepted: 10/17/2008] [Indexed: 12/31/2022] Open
Abstract
The role of tumor necrosis factor (TNF) as an immune mediator has long been appreciated but its function in the brain is still unclear. TNF receptor 1 (TNFR1) is expressed in most cell types, and can be activated by binding of either soluble TNF (solTNF) or transmembrane TNF (tmTNF), with a preference for solTNF; whereas TNFR2 is expressed primarily by microglia and endothelial cells and is preferentially activated by tmTNF. Elevation of solTNF is a hallmark of acute and chronic neuroinflammation as well as a number of neurodegenerative conditions including ischemic stroke, Alzheimer's (AD), Parkinson's (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). The presence of this potent inflammatory factor at sites of injury implicates it as a mediator of neuronal damage and disease pathogenesis, making TNF an attractive target for therapeutic development to treat acute and chronic neurodegenerative conditions. However, new and old observations from animal models and clinical trials reviewed here suggest solTNF and tmTNF exert different functions under normal and pathological conditions in the CNS. A potential role for TNF in synaptic scaling and hippocampal neurogenesis demonstrated by recent studies suggest additional in-depth mechanistic studies are warranted to delineate the distinct functions of the two TNF ligands in different parts of the brain prior to large-scale development of anti-TNF therapies in the CNS. If inactivation of TNF-dependent inflammation in the brain is warranted by additional pre-clinical studies, selective targeting of TNFR1-mediated signaling while sparing TNFR2 activation may lessen adverse effects of anti-TNF therapies in the CNS.
Collapse
Affiliation(s)
- Melissa K McCoy
- Department of Physiology, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9040, USA.
| | | |
Collapse
|
38
|
Gnjec A, D'Costa KJ, Laws SM, Hedley R, Balakrishnan K, Taddei K, Martins G, Paton A, Verdile G, Gandy SE, Broe GA, Brooks WS, Bennett H, Piguet O, Price P, Miklossy J, Hallmayer J, McGeer PL, Martins RN. Association of alleles carried at TNFA -850 and BAT1 -22 with Alzheimer's disease. J Neuroinflammation 2008; 5:36. [PMID: 18715507 PMCID: PMC2538517 DOI: 10.1186/1742-2094-5-36] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Accepted: 08/20/2008] [Indexed: 12/02/2022] Open
Abstract
Background Inflammatory changes are a prominent feature of brains affected by Alzheimer's disease (AD). Activated glial cells release inflammatory cytokines which modulate the neurodegenerative process. These cytokines are encoded by genes representing several interleukins and TNFA, which are associated with AD. The gene coding for HLA-B associated transcript 1 (BAT1) lies adjacent to TNFA in the central major histocompatibility complex (MHC). BAT1, a member of the DEAD-box family of RNA helicases, appears to regulate the production of inflammatory cytokines associated with AD pathology. In the current study TNFA and BAT1 promoter polymorphisms were analysed in AD and control cases and BAT1 mRNA levels were investigated in brain tissue from AD and control cases. Methods Genotyping was performed for polymorphisms at positions -850 and -308 in the proximal promoter of TNFA and position -22 in the promoter of BAT1. These were investigated singly or in haplotypic association in a cohort of Australian AD patients with AD stratified on the basis of their APOE ε4 genotype. Semi-quantitative RT-PCR was also performed for BAT1 from RNA isolated from brain tissue from AD and control cases. Results APOE ε4 was associated with an independent increase in risk for AD in individuals with TNFA -850*2, while carriage of BAT1 -22*2 reduced the risk for AD, independent of APOE ε4 genotype. Semi-quantitative mRNA analysis in human brain tissue showed elevated levels of BAT1 mRNA in frontal cortex of AD cases. Conclusion These findings lend support to the application of TNFA and BAT1 polymorphisms in early diagnosis or risk assessment strategies for AD and suggest a potential role for BAT1 in the regulation of inflammatory reactions in AD pathology.
Collapse
Affiliation(s)
- Anastazija Gnjec
- Centre of Excellence for Alzheimer's Disease Research and Care, Faculty of Computing, Health and Science, School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, 6027, WA, Australia.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Elahi MM, Gilmour A, Matata BM, Mastana SS. A variant of position -308 of the Tumour necrosis factor alpha gene promoter and the risk of coronary heart disease. Heart Lung Circ 2007; 17:14-8. [PMID: 17581788 DOI: 10.1016/j.hlc.2007.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 05/02/2007] [Accepted: 05/07/2007] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of this study was to investigate whether the variability between individuals with coronary heart disease (CHD) is related to the prevalence of TNF-alpha gene promoter -308 variant in un-matched British Caucasian population from East Midlands. PROCEDURES Genotypes and allele frequencies were determined using restriction fragment length polymorphism analysis of polymerase chain reaction (PCR) products. Genomic DNA prepared from peripheral blood leukocytes of patients (n=97) and healthy controls (n=95) demonstrated two alleles TNF*1 (G) and TNF*2 (A). FINDINGS The genotype distribution in patients was GG, n=59; GA, n=36; and AA, n=2 and in controls was GG, n=41; GA, n=40; and AA, n=14 (P=0.014). The association analysis demonstrated that TNF*1 allele in patients appears to be associated with greater incidences of CHD (OR 2.15; CI, 1.36-3.39; P=0.001). CONCLUSIONS Our results suggest that TNF*1 allele (TNF-alpha -308 GG or GA) has a high prevalence among British Caucasian population that correlates with an increased CHD risk.
Collapse
Affiliation(s)
- Maqsood M Elahi
- Department of Human Sciences, Loughborough University, Loughborough LE11 3TU, United Kingdom
| | | | | | | |
Collapse
|
40
|
von Bernhardi R, Ramírez G, Toro R, Eugenín J. Pro-inflammatory conditions promote neuronal damage mediated by Amyloid Precursor Protein and decrease its phagocytosis and degradation by microglial cells in culture. Neurobiol Dis 2007; 26:153-64. [PMID: 17240154 DOI: 10.1016/j.nbd.2006.12.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 12/05/2006] [Accepted: 12/10/2006] [Indexed: 10/23/2022] Open
Abstract
Aberrant handling of Amyloid Precursor Protein (APP) and beta-amyloid (Abeta), glial activation and inflammation are key events in Alzheimer's disease. We set out to determine the role of inflammation on microglial reactivity against APP. We studied microglia-mediated neurotoxicity, uptake and degradation of a biotinylated APP construct (biotin-APP-C-244). APP, in contrast to Abeta, only induced mild activation of glial cells. However, under pro-inflammatory conditions, APP induced microglial-mediated cytotoxicity. Biotin-APP-C-244 or lipopolysaccharide and interferon-gamma (LPS+IFNgamma), administered separately, did not change reduction metabolism of microglia. However, biotin-APP-C-244+(LPS+IFNgamma) increased microglial reactivity and decreased reduction metabolism by 75% (P<0.001). Biotin-APP-C-244 was readily taken up by microglial cells; 80% was phagocytosed at 2 h. In the presence of LPS+IFNgamma, phagocytosis of biotin-APP-C-244 was reduced at 2 h; and cell damage was evident after 4 h. Our results support our hypothesis that, in neuroinflammation, microglial scavenger function is impaired and reactivity against APP enhanced as an initial step for neurodegeneration.
Collapse
Affiliation(s)
- Rommy von Bernhardi
- Department of Neurology, Faculty of Medicine, Pontificia Universidad Católica de Chile Marcoleta 391, Santiago, Chile.
| | | | | | | |
Collapse
|
41
|
Sriram K, O'Callaghan JP. Divergent roles for tumor necrosis factor-alpha in the brain. J Neuroimmune Pharmacol 2007; 2:140-53. [PMID: 18040839 DOI: 10.1007/s11481-007-9070-6] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 03/01/2007] [Indexed: 01/05/2023]
Abstract
Proinflammatory cytokines and chemokines have been implicated in the pathogenesis of several neurological and neurodegenerative disorders. Prominent among such factors is the pleiotropic cytokine, tumor necrosis factor (TNF)-alpha. Under normal physiological conditions, TNF-alpha orchestrates a diverse array of functions involved in immune surveillance and defense, cellular homeostasis, and protection against certain neurological insults. However, paradoxical effects of this cytokine have been observed. TNF-alpha is elicited in the brain following injury (ischemia, trauma), infection (HIV, meningitis), neurodegeneration (Alzheimer's, Parkinson's), and chemically induced neurotoxicity. The multifarious identity for this cytokine appears to be influenced by several mechanisms. Among the most prominent are the regulation of TNFalpha-induced NF-kappaB activation by adapter proteins such as TRADD and TRAF, and second, the heterogeneity of microglia and their distribution pattern across brain regions. Here, we review the differential role of TNF-alpha in response to brain injury, with emphasis on neurodegeneration, and discuss the possible mechanisms for such diverse and region-specific effects.
Collapse
Affiliation(s)
- Krishnan Sriram
- National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, CDC-NIOSH, 1095 Willowdale Road, Morgantown, WV 26505, USA
| | | |
Collapse
|
42
|
Ma SL, Tang NLS, Zhang YP, Ji LD, Tam CWC, Lui VWC, Chiu HFK, Lam LCW. Association of prostaglandin-endoperoxide synthase 2 (PTGS2) polymorphisms and Alzheimer's disease in Chinese. Neurobiol Aging 2007; 29:856-60. [PMID: 17234302 DOI: 10.1016/j.neurobiolaging.2006.12.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2006] [Revised: 11/19/2006] [Accepted: 12/17/2006] [Indexed: 11/28/2022]
Abstract
Cyclooxygenase-2 (COX-2, encoded by the gene prostaglandin-endoperoxide synthase 2, PTGS2) is a key enzyme in the conversion of arachidonic acid to prostaglandins. The prostaglandins produced by COX-2 are involved in inflammation and pain response in different tissues in the body. Enhanced COX-2 expression had been found in regions of brains from patients with Alzheimer's disease (AD). Here, we proceeded to test the hypothesis that polymorphisms of the PTGS2 gene predispose to AD. IVS5-275 T>G and Ex10+837 T>C in addition to three tagging SNPs from HapMap database, which provided a comprehensive coverage of genetic variations in the PTGS2 gene in Chinese were genotyped among 257 AD patients and 244 age-matched healthy Chinese subjects. Genetic associations were analyzed by chi(2)-test and haplotypes analysis. Although the previously reported protective polymorphism (rs20417, -765 G/C) for AD in PTGS2 gene was not polymorphic in the Chinese population, SNPs in both the promoter (-2319 G>T) and 3' region (Ex10+837 T>C) of PTGS2 were associated with the risk of AD (p=0.01 and 0.03, respectively). Carriers of Ex10+837 T allele had a 1.5-fold increase in the risk of AD. This study suggested that PTGS2 gene was a predisposition gene and arachidonic acid metabolism might be involved in the pathogenesis of AD. It provided further evidence to support a role of inflammation in the development and progression of AD.
Collapse
Affiliation(s)
- Suk Ling Ma
- Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Lehmann DJ, Barnardo MCNM, Fuggle S, Quiroga I, Sutherland A, Warden DR, Barnetson L, Horton R, Beck S, Smith AD. Replication of the association of HLA-B7 with Alzheimer's disease: a role for homozygosity? J Neuroinflammation 2006; 3:33. [PMID: 17176470 PMCID: PMC1764414 DOI: 10.1186/1742-2094-3-33] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 12/18/2006] [Indexed: 11/17/2022] Open
Abstract
Background There are reasons to expect an association with Alzheimer's disease (AD) within the HLA region. The HLA-B & C genes have, however, been relatively understudied. A geographically specific association with HLA-B7 & HLA-Cw*0702 had been suggested by our previous, small study. Methods We studied the HLA-B & C alleles in 196 cases of 'definite' or 'probable' AD and 199 elderly controls of the OPTIMA cohort, the largest full study of these alleles in AD to date. Results We replicated the association of HLA-B7 with AD (overall, adjusted odds ratio = 2.3, 95% confidence interval = 1.4–3.7, p = 0.001), but not the previously suggested interaction with the ε4 allele of apolipoprotein E. Results for HLA-Cw*0702, which is in tight linkage disequilibrium with HLA-B7, were consistent with those for the latter. Homozygotes of both alleles appeared to be at particularly high risk of AD. Conclusion HLA-B7 and HLA-Cw*0702 are associated with AD in the Oxford population. Because of the contradictions between cohorts in our previous study, we suggest that these results may be geographically specific. This might be because of differences between populations in the structure of linkage disequilibrium or in interactions with environmental, genetic or epigenetic factors. A much larger study will be needed to clarify the role of homozygosity of HLA alleles in AD risk.
Collapse
Affiliation(s)
- Donald J Lehmann
- The Oxford Project to Investigate Memory and Ageing (OPTIMA), University Department of Pharmacology & Radcliffe Infirmary, Oxford, UK
- Oxford Centre for Gene Function, University Department of Physiology, Anatomy & Genetics, Parks Rd, Oxford OX1 3PT, UK
| | - Martin CNM Barnardo
- Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Transplant Centre, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Susan Fuggle
- Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Transplant Centre, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Isabel Quiroga
- Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Transplant Centre, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Andrew Sutherland
- Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Transplant Centre, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Donald R Warden
- The Oxford Project to Investigate Memory and Ageing (OPTIMA), University Department of Pharmacology & Radcliffe Infirmary, Oxford, UK
- Oxford Centre for Gene Function, University Department of Physiology, Anatomy & Genetics, Parks Rd, Oxford OX1 3PT, UK
| | - Lin Barnetson
- The Oxford Project to Investigate Memory and Ageing (OPTIMA), University Department of Pharmacology & Radcliffe Infirmary, Oxford, UK
| | - Roger Horton
- Immunogenomics Laboratory, Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Stephan Beck
- Immunogenomics Laboratory, Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - A David Smith
- The Oxford Project to Investigate Memory and Ageing (OPTIMA), University Department of Pharmacology & Radcliffe Infirmary, Oxford, UK
- Oxford Centre for Gene Function, University Department of Physiology, Anatomy & Genetics, Parks Rd, Oxford OX1 3PT, UK
| |
Collapse
|
44
|
Abstract
Based on experimental and neuropathologic studies, inflammation is postulated to play a central role in processes leading to neurodegeneration as well as vascular injury. To better understand the role of inflammation in cognitive disorders (CD), identify potential biomarkers for CD, and select individuals who may have a genetic susceptibility to CD, several different measures of inflammation have been employed in epidemiologic studies of CD, which are reviewed here. An inverse association of non-steroidal anti-inflammatory medications has been consistently reported. More variable are reports on the associations of various serum markers of cytokines to CD. There are few epidemiologic studies that have examined the association of CD and single nucleotide polymorphisms (SNP) regulating cytokines, although these have been examined in clinical case-control series. Data are summarized on the association of interleukin-1 SNPs from the Honolulu Asia Aging Study. There are many outstanding questions about the role of inflammation in CD and how best to measure it in the context of population-based studies.
Collapse
Affiliation(s)
- R Peila
- Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | | |
Collapse
|
45
|
Laws SM, Perneczky R, Wagenpfeil S, Müller U, Förstl H, Martins RN, Kurz A, Riemenschneider M. TNF polymorphisms in Alzheimer disease and functional implications on CSF beta-amyloid levels. Hum Mutat 2006; 26:29-35. [PMID: 15895461 DOI: 10.1002/humu.20180] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Alzheimer disease (AD), vascular dementia, and stroke are all associated with inflammation though their respective initiating factors differ. Recently a polymorphism in the proinflammatory cytokine tumor necrosis factor (TNF), in association with apolipoprotein E (APOE), was reported to increase AD risk. Two SNPs, rs1799724 (-850C>T; NT_007592.14:g.22400733C>T) and rs1800629 (-308G>A; [NT_007592.14:g.22401282G>A]), and the APOE polymorphism were genotyped in 506 patients with sporadic AD and in 277 cognitively healthy controls. In a subset of 90 individuals we also investigated whether these SNPs exerted any functional effects on cerebrospinal fluid (CSF) beta-amyloid (Abeta) levels. The frequency of the rs1799724 genotypes and the rs1799724-T allele were significantly different in AD individuals (P=0.009; odds ratio [OR], 1.63; 95% confidence interval [CI], 1.13-2.34), while the rs1800629 SNP was not associated with AD. Significant interaction was observed between the rs1799724-T and APOE epsilon4 alleles in that the rs1799724-T allele significantly modified risk associated with possession of the epsilon4 allele only (epsilon4 in absence of rs1799724-T: OR, 2.92; 95% CI, 2.00-4.27; epsilon4 in presence of rs1799724-T: OR, 6.65; 95% CI, 3.26-13.55; P=0.03). Haplotyping analysis revealed a significant overrepresentation of an rs1799724-T/rs1800629-G haplotype in AD (P=0.012; OR, 1.60; 95% CI, 1.11-2.29), although to a lesser degree than rs1799724-T alone. Further, the rs1799724-T allele was found to be associated with lower levels of CSF Abeta42 (P=0.023), thus corroborating the genetic findings. Inheritance of the rs1799724-T allele appears to synergistically increase the risk of AD in APOEepsilon4 carriers and is associated with altered CSF Abeta42 levels. Further investigations are warranted to assess the significance of these novel findings.
Collapse
Affiliation(s)
- Simon M Laws
- Alzheimer's and Aging, School of Biomedical and Sports Science, Edith Cowan University, Joondalup, Australia
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Chapuis J, Tian J, Shi J, Bensemain F, Cottel D, Lendon C, Amouyel P, Mann D, Lambert JC. Association study of the vascular endothelial growth factor gene with the risk of developing Alzheimer's disease. Neurobiol Aging 2006; 27:1212-5. [PMID: 16154235 DOI: 10.1016/j.neurobiolaging.2005.07.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Revised: 07/19/2005] [Accepted: 07/20/2005] [Indexed: 11/15/2022]
Abstract
Numerous observations indicate that cerebrovascular dysfunction contributes to cognitive decline and neurodegeneration in AD. Converging evidence points to a pivotal role for vascular endothelial growth factor (VEGF) in neuronal protection, and the lack of activity of this in neurodegenerative disorders. The VEGF gene is located at 6p21.3, a site several studies have shown to have significant linkage with AD, and a functional polymorphism within the VEGF promoter may alter the risk of developing AD. We assessed the potential impact of this polymorphism on the risk of developing AD in a large French case-control population, and investigated its association with the severity of brain vascular lesions (arteriosclerosis, white matter loss and cerebral amyloid angiopathy) in several brain regions (frontal, temporal, parietal and occipital cortex) in AD. No association of the VEGF promoter polymorphism with the risk of developing AD was observed. No relationship between this polymorphism and vascular pathological changes in AD was detected. Our data indicate that although this polymorphism is functional, it does not confer greater risk for AD, nor modulate the extent of vascular pathology.
Collapse
Affiliation(s)
- Julien Chapuis
- Unité INSERM 508, Institut Pasteur de Lille, 1 rue du Professeur Calmette, BP 245, 59019 Lille Cédex, France
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Sarkar D, Fisher PB. Molecular mechanisms of aging-associated inflammation. Cancer Lett 2006; 236:13-23. [PMID: 15978720 DOI: 10.1016/j.canlet.2005.04.009] [Citation(s) in RCA: 243] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2005] [Accepted: 04/12/2005] [Indexed: 10/25/2022]
Abstract
A direct relationship exists between aging and increasing incidences of chronic diseases. In fact, with most age-associated diseases individuals manifest an underlying chronic inflammatory state as evidenced by local infiltration of inflammatory cells, such as macrophages, and higher circulatory levels of pro-inflammatory cytokines, complement components and adhesion molecules. Consequently, treatment with anti-inflammatory agents provide symptomatic relief to several aging-associated diseases, even as remote as Alzheimer's or Parkinson's disease, indicating that chronic inflammation may play a substantial role in the pathogenesis of these disease states. The molecular mechanisms underlying this chronic inflammatory condition during cellular senescence is presently unclear. Cellular damage by oxygen free radicals is a primary driving force for aging and increased activation of redox-regulated transcription factors, such as NF-kappaB that regulate the expression of pro-inflammatory molecules, has been documented in aged animals/individuals versus their young counterparts. Human polynucleotide phosphorylase (hPNPase(old-35)), a RNA degradation enzyme shown to be upregulated during differentiation and cellular senescence, may represent a molecular link between aging and its associated inflammation. hPNPase(old-35) promotes reactive oxygen species (ROS) production, activates the NF-kappaB pathway and initiates the production of pro-inflammatory cytokines, such as IL-6 and IL-8. In these contexts, inhibition of hPNPase(old-35) may represent a novel molecular target for intervening in aging-associated chronic diseases.
Collapse
Affiliation(s)
- Devanand Sarkar
- Department of Pathology, Herbert Irving Comprehensive Cancer Center, College of Physicians & Surgeons, Columbia University Medical Center, New York, NY 10032, USA
| | | |
Collapse
|
48
|
Abstract
Dissecting the genetics of Alzheimer's disease (AD) and Parkinson's disease (PD) has contributed significantly to our understanding of the pathogenesis of neurodegeneration in these two complex disorders. For AD, three highly penetrant genes (amyloid precursor protein (APP, PSEN1 and PSEN2) and one susceptibility gene (APOE) have been identified. For PD, seven genes (SNCA, Parkin, UCHL1, NR4A2, DJ1, PINK1 and LRRK2) have been found. These genes explain only a small proportion of AD and PD patients and are mostly associated with an early onset presentation of the disease. APOE remains the only common gene, which increases the risk of both rare early and late onset AD. The ongoing challenge is to unravel the genetics of the most frequent forms of these complex disorders. In the present paper, we briefly review the state of the art in the genetics of AD and PD. We also discuss the prospects of finding new genes associated with common forms of these diseases in light of two hypotheses concerning the genetic variation of complex diseases: common disease/common variants and common disease/rare variants.
Collapse
Affiliation(s)
- Luba M Pardo
- Genetic Epidemiology Unit, Department of Epidemiology & Biostatistics, Erasmus Medical Center Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands
| | | |
Collapse
|
49
|
Genetics of Alzheimer's disease. NEURODEGENER DIS 2005. [DOI: 10.1017/cbo9780511544873.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
50
|
Nishimura M, Sakamoto T, Kaji R, Kawakami H. Influence of polymorphisms in the genes for cytokines and glutathione S-transferase omega on sporadic Alzheimer's disease. Neurosci Lett 2004; 368:140-3. [PMID: 15351436 DOI: 10.1016/j.neulet.2004.06.076] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Revised: 06/18/2004] [Accepted: 06/29/2004] [Indexed: 11/17/2022]
Abstract
We studied promoter region polymorphisms in the interleukin (IL)-1alpha, IL-1beta, IL-6, IL-10, tumor necrosis factor, and transforming growth factor (TGF)-beta1 genes in Japanese patients with Alzheimer's disease (AD) (n = 172) and normal controls (n = 163). We also examined an association of a polymorphism located in the glutathione S-transferase omega 1 (GSTO-1) gene region with AD patients. None of these genotypes or allele frequencies showed a significant difference between AD patients and controls. We also failed to detect any difference in the disease onset between each genotype of the seven polymorphisms. Although AD patients carrying high producer alleles of TGF-beta1 and IL-1beta or TGF-beta1 and IL-6 showed a tendency for an early onset of the disease, neither of these combined effects reached a significant level after multiple comparisons. Our findings suggest that genetic polymorphisms in the cytokines and GSTO do not play a major role in Japanese AD patients.
Collapse
|