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Schnöder L, Quan W, Yu Y, Tomic I, Luo Q, Hao W, Peng G, Li D, Fassbender K, Liu Y. Deficiency of IKKβ in neurons ameliorates Alzheimer's disease pathology in APP- and tau-transgenic mice. FASEB J 2023; 37:e22778. [PMID: 36688823 DOI: 10.1096/fj.202201512r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/21/2022] [Accepted: 01/06/2023] [Indexed: 01/24/2023]
Abstract
In Alzheimer's disease (AD) brain, inflammatory activation regulates protein levels of amyloid-β-peptide (Aβ) and phosphorylated tau (p-tau), as well as neurodegeneration; however, the regulatory mechanisms remain unclear. We constructed APP- and tau-transgenic AD mice with deletion of IKKβ specifically in neurons, and observed that IKKβ deficiency reduced cerebral Aβ and p-tau, and modified inflammatory activation in both AD mice. However, neuronal deficiency of IKKβ decreased apoptosis and maintained synaptic proteins (e.g., PSD-95 and Munc18-1) in the brain and improved cognitive function only in APP-transgenic mice, but not in tau-transgenic mice. Additionally, IKKβ deficiency decreased BACE1 protein and activity in APP-transgenic mouse brain and cultured SH-SY5Y cells. IKKβ deficiency increased expression of PP2A catalytic subunit isoform A, an enzyme dephosphorylating cerebral p-tau, in the brain of tau-transgenic mice. Interestingly, deficiency of IKKβ in neurons enhanced autophagy as indicated by the increased ratio of LC3B-II/I in brains of both APP- and tau-transgenic mice. Thus, IKKβ deficiency in neurons ameliorates AD-associated pathology in APP- and tau-transgenic mice, perhaps by decreasing Aβ production, increasing p-tau dephosphorylation, and promoting autophagy-mediated degradation of BACE1 and p-tau aggregates in the brain. However, IKKβ deficiency differently protects neurons in APP- and tau-transgenic mice. Further studies are needed, particularly in the context of interaction between Aβ and p-tau, before IKKβ/NF-κB can be targeted for AD therapies.
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Affiliation(s)
- Laura Schnöder
- Department of Neurology, Saarland University, Homburg, Germany
| | - Wenqiang Quan
- Department of Neurology, Saarland University, Homburg, Germany
- Department of Clinical Laboratory, Tongji Hospital, Tongji University Medical School, Shanghai, China
| | - Ye Yu
- Department of Neurology, Saarland University, Homburg, Germany
- Department of Neurology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Inge Tomic
- Department of Neurology, Saarland University, Homburg, Germany
| | - Qinghua Luo
- Department of Neurology, Saarland University, Homburg, Germany
| | - Wenlin Hao
- Department of Neurology, Saarland University, Homburg, Germany
| | - Guoping Peng
- Department of Neurology, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Dong Li
- Department of Clinical Laboratory, Tongji Hospital, Tongji University Medical School, Shanghai, China
| | | | - Yang Liu
- Department of Neurology, Saarland University, Homburg, Germany
- Department of Clinical Laboratory, Tongji Hospital, Tongji University Medical School, Shanghai, China
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Sato K, Takayama KI, Hashimoto M, Inoue S. Transcriptional and Post-Transcriptional Regulations of Amyloid-β Precursor Protein (APP ) mRNA. FRONTIERS IN AGING 2022; 2:721579. [PMID: 35822056 PMCID: PMC9261399 DOI: 10.3389/fragi.2021.721579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/28/2021] [Indexed: 01/01/2023]
Abstract
Alzheimer’s disease (AD) is an age-associated neurodegenerative disorder characterized by progressive impairment of memory, thinking, behavior, and dementia. Based on ample evidence showing neurotoxicity of amyloid-β (Aβ) aggregates in AD, proteolytically derived from amyloid precursor protein (APP), it has been assumed that misfolding of Aβ plays a crucial role in the AD pathogenesis. Additionally, extra copies of the APP gene caused by chromosomal duplication in patients with Down syndrome can promote AD pathogenesis, indicating the pathological involvement of the APP gene dose in AD. Furthermore, increased APP expression due to locus duplication and promoter mutation of APP has been found in familial AD. Given this background, we aimed to summarize the mechanism underlying the upregulation of APP expression levels from a cutting-edge perspective. We first reviewed the literature relevant to this issue, specifically focusing on the transcriptional regulation of APP by transcription factors that bind to the promoter/enhancer regions. APP expression is also regulated by growth factors, cytokines, and hormone, such as androgen. We further evaluated the possible involvement of post-transcriptional regulators of APP in AD pathogenesis, such as RNA splicing factors. Indeed, alternative splicing isoforms of APP are proposed to be involved in the increased production of Aβ. Moreover, non-coding RNAs, including microRNAs, post-transcriptionally regulate the APP expression. Collectively, elucidation of the novel mechanisms underlying the upregulation of APP would lead to the development of clinical diagnosis and treatment of AD.
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Affiliation(s)
- Kaoru Sato
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Ken-Ichi Takayama
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Makoto Hashimoto
- Department of Basic Technology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Satoshi Inoue
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
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3
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Chen D, Fang X, Zhu Z. Progress in the correlation of postoperative cognitive dysfunction and Alzheimer's disease and the potential therapeutic drug exploration. IBRAIN 2022; 9:446-462. [PMID: 38680509 PMCID: PMC11045201 DOI: 10.1002/ibra.12040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/27/2022] [Accepted: 05/02/2022] [Indexed: 05/01/2024]
Abstract
Postoperative cognitive dysfunction (POCD) is a decrease in mental capacity that can occur days to weeks after a medical procedure and may become permanent and rarely lasts for a longer period of time. With the continuous development of research, various viewpoints in academic circles have undergone subtle changes, and the role of anesthesia depth and anesthesia type seems to be gradually weakened; Alzheimer's disease (AD) is a latent and progressive neurodegenerative disease in the elderly. The protein hypothesis and the synaptic hypothesis are well-known reasons. These changes will also lead to the occurrence of an inflammatory cascade. The exact etiology and pathogenesis need to be studied. The reasonable biological mechanism affecting brain protein deposition, neuroinflammation, and acetylcholine-like effect has a certain relationship between AD and POCD. Whereas there is still further uncertainty about the mechanism and treatment, and it is elusive whether POCD is a link in the continuous progress of AD or a separate entity, which has doubts about the diagnosis and treatment of the disease. Therefore, this review is based on the current common clinical characteristics of AD and POCD, and pathophysiological research, to search for their common points and explore the direction and new strategies for future treatment.
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Affiliation(s)
- Dong‐Qin Chen
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
- College of AnesthesiologyZunyi Medical UniversityZunyiChina
| | - Xu Fang
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
- College of AnesthesiologyZunyi Medical UniversityZunyiChina
| | - Zhao‐Qiong Zhu
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityZunyiChina
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Yoo SM, Park J, Kim SH, Jung YK. Emerging perspectives on mitochondrial dysfunction and inflammation in Alzheimer's disease. BMB Rep 2020. [PMID: 31818363 PMCID: PMC6999830 DOI: 10.5483/bmbrep.2020.53.1.274] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Despite enduring diverse insults, mitochondria maintain normal functions through mitochondrial quality control. However, the failure of mitochondrial quality control resulting from excess damage and mechanical defects causes mitochondrial dysfunction, leading to various human diseases. Recent studies have reported that mitochondrial defects are found in Alzheimer’s disease (AD) and worsen AD symptoms. In AD pathogenesis, mitochondrial dysfunction-driven generation of reactive oxygen species (ROS) and their contribution to neuronal damage has been widely studied. In contrast, studies on mitochondrial dysfunction-associated inflammatory responses have been relatively scarce. Moreover, ROS produced upon failure of mitochondrial quality control may be linked to the inflammatory response and influence the progression of AD. Thus, this review will focus on inflammatory pathways that are associated with and initiated through defective mitochondria and will summarize recent progress on the role of mitochondria-mediated inflammation in AD. We will also discuss how reducing mitochondrial dysfunction-mediated inflammation could affect AD.
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Affiliation(s)
- Seung-Min Yoo
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Jisu Park
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Seo-Hyun Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Yong-Keun Jung
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
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Wang P, Velagapudi R, Kong C, Rodriguiz RM, Wetsel WC, Yang T, Berger M, Gelbard HA, Colton CA, Terrando N. Neurovascular and immune mechanisms that regulate postoperative delirium superimposed on dementia. Alzheimers Dement 2020; 16:734-749. [PMID: 32291962 PMCID: PMC7317948 DOI: 10.1002/alz.12064] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/04/2019] [Accepted: 01/03/2020] [Indexed: 12/14/2022]
Abstract
Objective The present work evaluates the relationship between postoperative immune and neurovascular changes and the pathogenesis of surgery‐induced delirium superimposed on dementia. Background and rationale Postoperative delirium is a common complication in many older adults and in patients with dementia including Alzheimer's disease (AD). The course of delirium can be particularly debilitating, while its pathophysiology remains poorly defined. Historical evolution As of 2019, an estimated 5.8 million people of all ages have been diagnosed with AD, 97% of whom are >65 years of age. Each year, many of these patients require surgery. However, anesthesia and surgery can increase the risk for further cognitive decline. Surgery triggers neuroinflammation both in animal models and in humans, and a failure to resolve this inflammatory state may contribute to perioperative neurocognitive disorders as well as neurodegenerative pathology. Updated hypothesis We propose an immunovascular hypothesis whereby dysregulated innate immunity negatively affects the blood‐brain interface, which triggers delirium and thereby exacerbates AD neuropathology. Early experimental data We have developed a translational model to study delirium superimposed on dementia in APPSwDI/mNos2−/− AD mice (CVN‐AD) after orthopedic surgery. At 12 months of age, CVN‐AD showed distinct neuroimmune and vascular impairments after surgery, including acute microgliosis and amyloid‐β deposition. These changes correlated with attention deficits, a core feature of delirium‐like behavior. Future experiments and validation studies Future research should determine the extent to which prevention of surgery‐induced microgliosis and/or neurovascular unit dysfunction can prevent or ameliorate postoperative memory and attention deficits in animal models. Translational human studies should evaluate perioperative indices of innate immunity and neurovascular integrity and assess their potential link to perioperative neurocognitive disorders. Major challenges for the hypothesis Understanding the complex relationships between delirium and dementia will require mechanistic studies aimed at evaluating the role of postoperative neuroinflammation and blood‐brain barrier changes in the setting of pre‐existing neurodegenerative and/or aging‐related pathology. Linkage to other major theories Non‐resolving inflammation with vascular disease that leads to cognitive impairments and dementia is increasingly important in risk stratification for AD in the aging population. The interdependence of these factors with surgery‐induced neuroinflammation and cognitive dysfunction is also becoming apparent, providing a strong platform for assessing the relationship between postoperative delirium and longer term cognitive dysfunction in older adults.
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Affiliation(s)
- Ping Wang
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Ravikanth Velagapudi
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Cuicui Kong
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Ramona M Rodriguiz
- Department of Psychiatry and Behavioral Sciences, Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, North Carolina, USA
| | - William C Wetsel
- Department of Psychiatry and Behavioral Sciences, Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, North Carolina, USA.,Departments of Neurobiology and Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
| | - Ting Yang
- Department of Medicine, Division of Nephrology, Duke University Medical Center, Durham, North Carolina, USA
| | - Miles Berger
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Harris A Gelbard
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York, USA
| | - Carol A Colton
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Niccolò Terrando
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
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Gu Y, Wu Z, Zeng F, Jiang M, Teeling JL, Ni J, Takahashi I. Systemic Exposure to Lipopolysaccharide from Porphyromonas gingivalis Induces Bone Loss-Correlated Alzheimer's Disease-Like Pathologies in Middle-Aged Mice. J Alzheimers Dis 2020; 78:61-74. [PMID: 32925065 DOI: 10.3233/jad-200689] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) and bone loss are clinically exacerbated. However, the mechanism of exacerbation remains understood. OBJECTIVE We tested our hypothesis that periodontitis is involved in the exacerbation, contributing to AD pathologies. METHODS The bone, memory, and inflammation in bone and brain were examined in 12-month-old mice after systemic exposure to lipopolysaccharide from Porphyromonas gingivalis (P gLPS) for 3 consecutive weeks. RESULTS Compared with control mice, bone loss in tibia (26% decrease) and memory decline (47% decrease) were induced in mice with a positive correlation after exposure to P gLPS (r = 0.7378, p = 0.0011). The IL-6 and IL-17 expression in tibia was negatively correlated with the bone volume/total tissue volume (r = -0.6619, p = 0.0052; r = -0.7129, p = 0.0019), while that in the cortex was negatively correlated with the memory test latency (r = -0.7198, p = 0.0017; p = 0.0351, r = -0.5291). Furthermore, the IL-17 expression in microglia was positively correlated with Aβ42 accumulation in neurons (r = 0.8635, p < 0.0001). In cultured MG6 microglia, the P gLPS-increased IL-6 expression was inhibited by a PI3K-specific inhibitor (68% decrease), and that of IL-17 was inhibited by IL-6 antibody (41% decrease). In cultured N2a neurons, conditioned medium from P gLPS-stimulated microglia (MCM) but not P gLPS increased the productions of AβPP, CatB, and Aβ42, which were significantly inhibited by pre-treatment with IL-17 antibody (67%, 51%, and 41% decrease). CONCLUSION These findings demonstrated that chronic systemic exposure to P gLPS simultaneously induces inflammation-dependent bone loss and AD-like pathologies by elevating IL-6 and IL-17 from middle age, suggesting that periodontal bacteria induce exacerbation of bone loss and memory decline, resulting in AD progression.
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Affiliation(s)
- Yebo Gu
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Zhou Wu
- Department of Aging Science and Pharmacology, Faculty of Dental Sciences, Kyushu University, Fukuoka, Japan
- OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Fan Zeng
- Department of Aging Science and Pharmacology, Faculty of Dental Sciences, Kyushu University, Fukuoka, Japan
| | - Muzhou Jiang
- Department of Aging Science and Pharmacology, Faculty of Dental Sciences, Kyushu University, Fukuoka, Japan
| | - Jessica L Teeling
- Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, United Kingdom
| | - Junjun Ni
- Department of Aging Science and Pharmacology, Faculty of Dental Sciences, Kyushu University, Fukuoka, Japan
- Key Laboratory of Molecular Medicine, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Ichiro Takahashi
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
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7
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Newcombe EA, Camats-Perna J, Silva ML, Valmas N, Huat TJ, Medeiros R. Inflammation: the link between comorbidities, genetics, and Alzheimer's disease. J Neuroinflammation 2018; 15:276. [PMID: 30249283 PMCID: PMC6154824 DOI: 10.1186/s12974-018-1313-3] [Citation(s) in RCA: 321] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/11/2018] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder, most cases of which lack a clear causative event. This has made the disease difficult to characterize and, thus, diagnose. Although some cases are genetically linked, there are many diseases and lifestyle factors that can lead to an increased risk of developing AD, including traumatic brain injury, diabetes, hypertension, obesity, and other metabolic syndromes, in addition to aging. Identifying common factors and trends between these conditions could enhance our understanding of AD and lead to the development of more effective treatments. Although the immune system is one of the body’s key defense mechanisms, chronic inflammation has been increasingly linked with several age-related diseases. Moreover, it is now well accepted that chronic inflammation has an important role in the onset and progression of AD. In this review, the different inflammatory signals associated with AD and its risk factors will be outlined to demonstrate how chronic inflammation may be influencing individual susceptibility to AD. Our goal is to bring attention to potential shared signals presented by the immune system during different conditions that could lead to the development of successful treatments.
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Affiliation(s)
- Estella A Newcombe
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia.
| | - Judith Camats-Perna
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia
| | - Mallone L Silva
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia
| | - Nicholas Valmas
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Tee Jong Huat
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia.,Centre for Stem Cell Ageing and Regenerative Engineering, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Rodrigo Medeiros
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia.
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Palmitic Acid-BSA enhances Amyloid-β production through GPR40-mediated dual pathways in neuronal cells: Involvement of the Akt/mTOR/HIF-1α and Akt/NF-κB pathways. Sci Rep 2017; 7:4335. [PMID: 28659580 PMCID: PMC5489526 DOI: 10.1038/s41598-017-04175-w] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 05/10/2017] [Indexed: 12/14/2022] Open
Abstract
The pathophysiological actions of fatty acids (FAs) on Alzheimer’s disease (AD), which are possibly mediated by genomic effects, are widely known; however, their non-genomic actions remain elusive. The aim of this study was to investigate the non-genomic mechanism of extra-cellular palmitic acid (PA) regulating beta-amyloid peptide (Aβ) production, which may provide a link between obesity and the occurrence of AD. In an obese mouse model, a high-fat diet (HFD) significantly increased the expression levels of APP and BACE1 as well as the AD pathology in the mouse brain. We further found that PA conjugated with bovine serum albumin (PA-BSA) increased the expression of APP and BACE1 and the production of Aβ through the G protein-coupled receptor 40 (GPR40) in SK-N-MC cells. PA-BSA coupling with GPR40 significantly induced Akt activation which is required for mTOR/p70S6K1-mediated HIF-1α expression and NF-κB phosphorylation facilitating the transcriptional activity of the APP and BACE1 genes. In addition, silencing of APP and BACE1 expression significantly decreased the production of Aβ in SK-N-MC cells treated with PA-BSA. In conclusion, these results show that extra-cellular PA coupled with GPR40 induces the expression of APP and BACE1 to facilitate Aβ production via the Akt-mTOR-HIF-1α and Akt-NF-κB pathways in SK-N-MC cells.
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9
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Kim YE, Hwang CJ, Lee HP, Kim CS, Son DJ, Ham YW, Hellström M, Han SB, Kim HS, Park EK, Hong JT. Inhibitory effect of punicalagin on lipopolysaccharide-induced neuroinflammation, oxidative stress and memory impairment via inhibition of nuclear factor-kappaB. Neuropharmacology 2017; 117:21-32. [DOI: 10.1016/j.neuropharm.2017.01.025] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 12/13/2022]
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10
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Therapeutic Strategies Under Development Targeting Inflammatory Mechanisms in Amyotrophic Lateral Sclerosis. Mol Neurobiol 2017; 55:2789-2813. [DOI: 10.1007/s12035-017-0532-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/06/2017] [Indexed: 12/11/2022]
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11
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Snow WM, Albensi BC. Neuronal Gene Targets of NF-κB and Their Dysregulation in Alzheimer's Disease. Front Mol Neurosci 2016; 9:118. [PMID: 27881951 PMCID: PMC5101203 DOI: 10.3389/fnmol.2016.00118] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/25/2016] [Indexed: 11/21/2022] Open
Abstract
Although, better known for its role in inflammation, the transcription factor nuclear factor kappa B (NF-κB) has more recently been implicated in synaptic plasticity, learning, and memory. This has been, in part, to the discovery of its localization not just in glia, cells that are integral to mediating the inflammatory process in the brain, but also neurons. Several effectors of neuronal NF-κB have been identified, including calcium, inflammatory cytokines (i.e., tumor necrosis factor alpha), and the induction of experimental paradigms thought to reflect learning and memory at the cellular level (i.e., long-term potentiation). NF-κB is also activated after learning and memory formation in vivo. In turn, activation of NF-κB can elicit either suppression or activation of other genes. Studies are only beginning to elucidate the multitude of neuronal gene targets of NF-κB in the normal brain, but research to date has confirmed targets involved in a wide array of cellular processes, including cell signaling and growth, neurotransmission, redox signaling, and gene regulation. Further, several lines of research confirm dysregulation of NF-κB in Alzheimer's disease (AD), a disorder characterized clinically by a profound deficit in the ability to form new memories. AD-related neuropathology includes the characteristic amyloid beta plaque formation and neurofibrillary tangles. Although, such neuropathological findings have been hypothesized to contribute to memory deficits in AD, research has identified perturbations at the cellular and synaptic level that occur even prior to more gross pathologies, including transcriptional dysregulation. Indeed, synaptic disturbances appear to be a significant correlate of cognitive deficits in AD. Given the more recently identified role for NF-κB in memory and synaptic transmission in the normal brain, the expansive network of gene targets of NF-κB, and its dysregulation in AD, a thorough understanding of NF-κB-related signaling in AD is warranted and may have important implications for uncovering treatments for the disease. This review aims to provide a comprehensive view of our current understanding of the gene targets of this transcription factor in neurons in the intact brain and provide an overview of studies investigating NF-κB signaling, including its downstream targets, in the AD brain as a means of uncovering the basic physiological mechanisms by which memory becomes fragile in the disease.
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Affiliation(s)
- Wanda M Snow
- Division of Neurodegenerative Disorders, St. Boniface Hospital ResearchWinnipeg, MB, Canada; Department of Pharmacology and Therapeutics, University of ManitobaWinnipeg, MB, Canada
| | - Benedict C Albensi
- Division of Neurodegenerative Disorders, St. Boniface Hospital ResearchWinnipeg, MB, Canada; Department of Pharmacology and Therapeutics, University of ManitobaWinnipeg, MB, Canada
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12
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Wilkins HM, Koppel SJ, Weidling IW, Roy N, Ryan LN, Stanford JA, Swerdlow RH. Extracellular Mitochondria and Mitochondrial Components Act as Damage-Associated Molecular Pattern Molecules in the Mouse Brain. J Neuroimmune Pharmacol 2016; 11:622-628. [PMID: 27562848 DOI: 10.1007/s11481-016-9704-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/17/2016] [Indexed: 11/26/2022]
Abstract
Mitochondria and mitochondrial debris are found in the brain's extracellular space, and extracellular mitochondrial components can act as damage associated molecular pattern (DAMP) molecules. To characterize the effects of potential mitochondrial DAMP molecules on neuroinflammation, we injected either isolated mitochondria or mitochondrial DNA (mtDNA) into hippocampi of C57BL/6 mice and seven days later measured markers of inflammation. Brains injected with whole mitochondria showed increased Tnfα and decreased Trem2 mRNA, increased GFAP protein, and increased NFκB phosphorylation. Some of these effects were also observed in brains injected with mtDNA (decreased Trem2 mRNA, increased GFAP protein, and increased NFκB phosphorylation), and mtDNA injection also caused several unique changes including increased CSF1R protein and AKT phosphorylation. To further establish the potential relevance of this response to Alzheimer's disease (AD), a brain disorder characterized by neurodegeneration, mitochondrial dysfunction, and neuroinflammation we also measured App mRNA, APP protein, and Aβ1-42 levels. We found mitochondria (but not mtDNA) injections increased these parameters. Our data show that in the mouse brain extracellular mitochondria and its components can induce neuroinflammation, extracellular mtDNA or mtDNA-associated proteins can contribute to this effect, and mitochondria derived-DAMP molecules can influence AD-associated biomarkers.
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Affiliation(s)
- Heather M Wilkins
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA
| | - Scott J Koppel
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA
| | - Ian W Weidling
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Nairita Roy
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Lauren N Ryan
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA
| | - John A Stanford
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Russell H Swerdlow
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA.
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA.
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA.
- University of Kansas School of Medicine, MS 2012, Landon Center on Aging, 3901 Rainbow Blvd, Kansas City, KS, 66160, USA.
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13
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Wilkins HM, Carl SM, Weber SG, Ramanujan SA, Festoff BW, Linseman DA, Swerdlow RH. Mitochondrial lysates induce inflammation and Alzheimer's disease-relevant changes in microglial and neuronal cells. J Alzheimers Dis 2016; 45:305-18. [PMID: 25537010 DOI: 10.3233/jad-142334] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neuroinflammation occurs in Alzheimer's disease (AD). While AD genetic studies implicate inflammation-relevant genes and fibrillar amyloid-β protein promotes inflammation, our understanding of AD neuroinflammation nevertheless remains incomplete. In this study we hypothesized damage-associated molecular pattern (DAMP) molecules arising from mitochondria, intracellular organelles that resemble bacteria, could contribute to AD neuroinflammation. To preliminarily test this possibility, we exposed neuronal and microglial cell lines to enriched mitochondrial lysates. BV2 microglial cells treated with mitochondrial lysates showed decreased TREM2 mRNA, increased TNFα mRNA, increased MMP-8 mRNA, increased IL-8 mRNA, redistribution of NFκB to the nucleus, and increased p38 MAPK phosphorylation. SH-SY5Y neuronal cells treated with mitochondrial lysates showed increased TNFα mRNA, increased NFκB protein, decreased IκBα protein, increased AβPP mRNA, and increased AβPP protein. Enriched mitochondrial lysates from SH-SY5Y cells lacking detectable mitochondrial DNA (ρ0 cells) failed to induce any of these changes, while mtDNA obtained directly from mitochondria (but not PCR-amplified mtDNA) increased BV2 cell TNFα mRNA. These results indicate at least one mitochondrial-derived DAMP molecule, mtDNA, can induce inflammatory changes in microglial and neuronal cell lines. Our data are consistent with the hypothesis that a mitochondrial-derived DAMP molecule or molecules could contribute to AD neuroinflammation.
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Affiliation(s)
- Heather M Wilkins
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Steven M Carl
- University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Sam G Weber
- University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Suruchi A Ramanujan
- University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Barry W Festoff
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA Department of Pharmacology, University of Kansas Medical Center, Kansas City, KS, USA Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA PHLOGISTIX Neurodiagnostics, Lenexa, KS, USA
| | | | - Russell H Swerdlow
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, USA Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
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Yun HM, Kim JA, Hwang CJ, Jin P, Baek MK, Lee JM, Hong JE, Lee SM, Han SB, Oh KW, Choi DY, Yoon DY, Hong JT. Neuroinflammatory and Amyloidogenic Activities of IL-32β in Alzheimer's Disease. Mol Neurobiol 2014; 52:341-52. [PMID: 25159479 DOI: 10.1007/s12035-014-8860-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/11/2014] [Indexed: 12/21/2022]
Abstract
Interleukin (IL)-32β can act as either pro-inflammatory or anti-inflammatory cytokines with being dependent on the status of disease development. Herein, we investigated whether IL-32β overexpression changes cytokine levels and affects amyloid-beta (Aβ)-induced pro-inflammation in the brain. IL-32β transgenic (Tg) mice and non-Tg mice were intracerebroventricularly infused with Aβ1-42 once a day for 14 days, and then cognitive function was assessed by the Morris water maze test and passive avoidance test. Our data showed that IL-32β Tg mice increased memory impairment, glia activation, amyloidogenesis, and neuroinflammation. The expression of glial fibrillary acid protein (GFAP), Iba1, and β-secretase 1 (BACE1) in the cortex and hippocampus was much higher in the Aβ1-42-infused IL-32β Tg mice brain. The activation of signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-κB) was much higher in Aβ1-42-infused IL-32β Tg mice brain. We also found that cytokines including IP-10, GM-CSF, JE, IL-13, and interferone-inducible T cell α chemoattractant (I-TAC) were elevated in Aβ1-42-infused IL-32β Tg mice brain. These results suggest that IL-32β could activate NF-κB and STAT3, and thus affect neuroinflammation as well as amyloidogenesis, leading to worsening memory impairment.
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Affiliation(s)
- Hyung-Mun Yun
- College of Pharmacy, Medical Research Center, Chungbuk National University, 12 Gaesin-dong, Heungduk-gu, Cheongju, Chungbuk, 361-763, South Korea
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15
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Chen XF, Zhang YW, Xu H, Bu G. Transcriptional regulation and its misregulation in Alzheimer's disease. Mol Brain 2013; 6:44. [PMID: 24144318 PMCID: PMC3854070 DOI: 10.1186/1756-6606-6-44] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 10/15/2013] [Indexed: 11/25/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder characterized by loss of memory and cognitive function. A key neuropathological event in AD is the accumulation of amyloid-β (Aβ) peptide. The production and clearance of Aβ in the brain are regulated by a large group of genes. The expression levels of these genes must be fine-tuned in the brain to keep Aβ at a balanced amount under physiological condition. Misregulation of AD genes has been found to either increase AD risk or accelerate the disease progression. In recent years, important progress has been made in uncovering the regulatory elements and transcriptional factors that guide the expression of these genes. In this review, we describe the mechanisms of transcriptional regulation for the known AD genes and the misregualtion that leads to AD susceptibility.
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Affiliation(s)
- Xiao-Fen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, 361102 Xiamen, Fujian, People's Republic of China.
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16
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Roles for NF-κB and gene targets of NF-κB in synaptic plasticity, memory, and navigation. Mol Neurobiol 2013; 49:757-70. [PMID: 24122352 DOI: 10.1007/s12035-013-8555-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 09/19/2013] [Indexed: 01/04/2023]
Abstract
Although traditionally associated with immune function, the transcription factor nuclear factor kappa B (NF-κB) has garnered much attention in recent years as an important regulator of memory. Specifically, research has found that NF-κB, localized in both neurons and glia, is activated during the induction of long-term potentiation (LTP), a paradigm of synaptic plasticity and correlate of memory. Further, experimental manipulation of NF-κB activation or its blockade results in altered memory and spatial navigation abilities. Genetic knockout of specific NF-κB subunits in mice results in memory alterations. Collectively, such data suggest that NF-κB may be a requirement for memory, although the direction of the response (i.e., memory enhancement or deficit) is inconsistent. A limited number of gene targets of NF-κB have been recently identified in neurons, including neurotrophic factors, calcium-regulating proteins, other transcription factors, and molecules associated with neuronal outgrowth and remodeling. In turn, several key molecules are activators of NF-κB, including protein kinase C and [Ca(++)]i. Thus, NF-κB signaling is complex and under the regulation of numerous proteins involved in activity-dependent synaptic plasticity. The purpose of this review is to highlight the literature detailing a role for NF-κB in synaptic plasticity, memory, and spatial navigation. Secondly, this review will synthesize the research evaluating gene targets of NF-κB in synaptic plasticity and memory. Although there is ample evidence to suggest a critical role for NF-κB in memory, our understanding of its gene targets in neurons is limited and only beginning to be appreciated.
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Inhibitory effect of a 2,4-bis(4-hydroxyphenyl)-2-butenal diacetate on neuro-inflammatory reactions via inhibition of STAT1 and STAT3 activation in cultured astrocytes and microglial BV-2 cells. Neuropharmacology 2013; 79:476-87. [PMID: 23891616 DOI: 10.1016/j.neuropharm.2013.06.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 06/02/2013] [Accepted: 06/19/2013] [Indexed: 11/21/2022]
Abstract
2,4-Bis(p-hydroxyphenyl)-2-butenal (Butenal), a tyrosine-fructose Maillard reaction product has been demonstrated as an effective compound for prevention of neuroinflammatory diseases. However, this compound was vulnerable to environmental factors. Our research has been continuously made to improve druggability of Butenal and identified 2,4-bis(4-hydroxyphenyl)but-2-enal diacetate (HPBD) as an alternative. Herein, to investigate potential anti-neuroinflammatory and anti-amyloidogenic effects of HPBD, we treated HPBD (0.5, 1, and 2 μg/ml) on the lipopolysaccharides (LPS) (1 μg/ml) stimulated astrocytes and microglial BV-2 cell. HPBD inhibited LPS-induced NO and ROS production, and LPS-elevated expression of iNOS, COX2, β-site APP-cleaving enzyme 1 (BACE1), C99, and Aβ1-42 levels as well as attenuation of β-secretase activities. The activation of nuclear factor-kappaB (NF-κB), signal transducer and activator of transcription1 (STAT1), and STAT3 was concomitantly inhibited by HPBD. Moreover, siRNA targeting STAT3 abolished HPBD-induced inhibitory effects on neuro-inflammation and amyloidogenesis. In addition, pull down assay and docking model showed interaction of HPBD with STAT3. These findings suggest that HPBD may be useful and potentially therapeutic choices for the treatment of neuroinflammatory diseases.
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Yang Y, Wu Y, Zhang S, Song W. High glucose promotes Aβ production by inhibiting APP degradation. PLoS One 2013; 8:e69824. [PMID: 23894546 PMCID: PMC3720941 DOI: 10.1371/journal.pone.0069824] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 06/17/2013] [Indexed: 12/21/2022] Open
Abstract
Abnormal deposition of neuriticplaques is the uniqueneuropathological hallmark of Alzheimer’s disease (AD).Amyloid β protein (Aβ), the major component of plaques, is generated from sequential cleavage of amyloidβ precursor protein (APP) by β-secretase and γ-secretase complex. Patients with diabetes mellitus (DM), characterized by chronic hyperglycemia,have increased risk of AD development.However, the role of high blood glucose in APP processing and Aβ generation remains elusive. In this study, we investigated the effect of high glucose on APP metabolism and Aβ generation in cultured human cells. We found that high glucose treatment significantly increased APP protein level in both neuronal-like and non-neuronal cells, and promoted Aβ generation. Furthermore, we found that high glucose-induced increase of APP level was not due to enhancement of APP gene transcription but resulted from inhibition of APP protein degradation. Taken together, our data indicated that hyperglycemia could promote AD pathogenesis by inhibiting APP degradation and enhancing Aβ production. More importantly, the elevation of APP level and Aβ generation by high glucose was caused by reduction of APP turnover rate.Thus,our study provides a molecular mechanism of increased risk of developing AD in patients withDMand suggests thatglycemic control might be potentially beneficial for reducing the incidence of AD in diabetic patients and delaying the AD progression.
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Affiliation(s)
- Yi Yang
- Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, Graduate Program in Neuroscience, The University of British Columbia, Vancouver, Canada
| | - Yili Wu
- The Ministry of Education Key Laboratory of Child Development and Disorders, and Chongqing City Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Shuting Zhang
- Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, Graduate Program in Neuroscience, The University of British Columbia, Vancouver, Canada
| | - Weihong Song
- Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, Graduate Program in Neuroscience, The University of British Columbia, Vancouver, Canada
- The Ministry of Education Key Laboratory of Child Development and Disorders, and Chongqing City Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Children’s Hospital of Chongqing Medical University, Chongqing, China
- * E-mail:
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19
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Xie K, Liu Y, Hao W, Walter S, Penke B, Hartmann T, Schachner M, Fassbender K. Tenascin-C deficiency ameliorates Alzheimer's disease-related pathology in mice. Neurobiol Aging 2013; 34:2389-98. [PMID: 23673309 DOI: 10.1016/j.neurobiolaging.2013.04.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 04/07/2013] [Accepted: 04/14/2013] [Indexed: 11/24/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by deposits of amyloid β peptide (Aβ) and microglia-driven inflammatory activation. Tenascin-C (tnc) is an extracellular matrix protein that is upregulated in inflammation and induces further inflammatory responses. We hypothesized that tnc contributes to the inflammatory pathology in AD. Using real-time polymerase chain reaction, we observed that tnc gene transcription was upregulated in cultured microglia after Aβ challenge and in the brain of an AD mouse model that overexpresses mutated amyloid precursor protein (APP) in neural cells. By cross-breeding APP-transgenic mice and tenascin-C-deficient mice, we demonstrated using real-time polymerase chain reaction, Western blot analysis, enzyme-linked immunosorbent assay, and immunohistochemistry that tnc deficiency reduces pro- but enhances anti-inflammatory activation in the mutated APP-transgenic mouse brain, associated with a reduced cerebral Aβ load and higher levels of the postsynaptic density protein 95. Thus, our study indicates that functional inhibition of tnc exerts beneficial effects on AD pathogenesis, suggesting a potential for tnc as a new therapeutic target in AD.
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Affiliation(s)
- Kan Xie
- Department of Neurology, University of the Saarland, Homburg/Saar, Germany
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Niranjan R. Molecular Basis of Etiological Implications in Alzheimer’s Disease: Focus on Neuroinflammation. Mol Neurobiol 2013; 48:412-28. [DOI: 10.1007/s12035-013-8428-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 02/06/2013] [Indexed: 12/31/2022]
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Gu X, Sun J, Li S, Wu X, Li L. Oxidative stress induces DNA demethylation and histone acetylation in SH-SY5Y cells: potential epigenetic mechanisms in gene transcription in Aβ production. Neurobiol Aging 2012; 34:1069-79. [PMID: 23141413 DOI: 10.1016/j.neurobiolaging.2012.10.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 10/10/2012] [Accepted: 10/16/2012] [Indexed: 10/27/2022]
Abstract
Overwhelming evidence has suggested that enhanced oxidative stress is involved in the pathogenesis and/or progression of Alzheimer's disease (AD). Amyloid-β (Aβ) that composes senile plaques plays a causal role in AD, and its abnormal deposition in brains is the typical neuropathologic hallmark of AD. Recent studies have suggested that epigenetic mechanisms play an important role in the initiation and development of AD. In the present study, we investigated the epigenetic mechanisms, such as DNA methylation and histone acetylation, involved in the transcription of AD-related genes with Aβ production under oxidative stress. Human neuroblastoma SH-SY5Y cells were treated with hydrogen peroxide (H(2)O(2)) and used as the cell model. The intracellular Aβ level was significantly increased in H(2)O(2)-treated SH-SY5Y cells. The expression of amyloid-β precursor protein and β-site amyloid-β precursor protein-cleaving enzyme 1 was upregulated by demethylation in the gene promoters associated with the reduction of methyltransferases. Meanwhile, H(2)O(2) induced the upregulation of histone acetyltransferases p300/cAMP-response element binding protein (p300/CBP) and downregulation of histone deacetylases. DNA hypomethylation induced by DNA methyltransferase inhibitor could activate the DNA binding activity of transcription factor nuclear factor-κB, whereas no significant effect was observed on specific protein 1. DNA binding activities of nuclear factor-κB and specific protein 1 were activated by histone hyperacetylation induced by histone deacetylase inhibitor. These findings suggested that oxidative stress resulted in an imbalance between DNA methylation and demethylation and histone acetylation and deacetylation associated with the activation of transcription factors, leading to the AD-related gene transcription in the Aβ overproduction. This could be a potential mechanism for oxidative stress response, which might contribute to the pathogenesis and development of AD.
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Affiliation(s)
- Xinling Gu
- Department of Pathology, Key Laboratory for Neurodegenerative Disease of Education Ministry, Capital Medical University, Beijing, China
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22
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Chami L, Buggia-Prévot V, Duplan E, Delprete D, Chami M, Peyron JF, Checler F. Nuclear factor-κB regulates βAPP and β- and γ-secretases differently at physiological and supraphysiological Aβ concentrations. J Biol Chem 2012; 287:24573-84. [PMID: 22654105 PMCID: PMC3397882 DOI: 10.1074/jbc.m111.333054] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 05/14/2012] [Indexed: 11/06/2022] Open
Abstract
Anatomical lesions in Alzheimer disease-affected brains mainly consist of senile plaques, inflammation stigmata, and oxidative stress. The nuclear factor-κB (NF-κB) is a stress-activated transcription factor that is activated around senile plaques. We have assessed whether NF-κB could be differentially regulated at physiological or supraphysiological levels of amyloid β (Aβ) peptides. Under these experimental conditions, we delineated the putative NF-κB-dependent modulation of all cellular participants in Aβ production, namely its precursor βAPP (β-amyloid precursor protein) and the β- and γ-secretases, the two enzymatic machines involved in Aβ genesis. Under physiological conditions, NF-κB lowers the transcriptional activity of the promoters of βAPP, β-secretase (β-site APP-cleaving enzyme 1, BACE1), and of the four protein components (Aph-1, Pen-2, nicastrin, presenilin-1, or presenilin-2) of the γ-secretase in HEK293 cells. This was accompanied by a reduction of both protein levels and enzymatic activities, thereby ultimately yielding lower amounts of Aβ and AICD (APP intracellular domain). In stably transfected Swedish βAPP-expressing HEK293 cells triggering supraphysiological concentrations of Aβ peptides, NF-κB activates the transcription of βAPP, BACE1, and some of the γ-secretase members and increases protein expression and enzymatic activities, resulting in enhanced Aβ production. Our pharmacological approach using distinct NF-κB kinase modulators indicates that both NF-κB canonical and alternative pathways are involved in the control of Aβ production. Overall, our data demonstrate that under physiological conditions, NF-κB triggers a repressive effect on Aβ production that contributes to maintaining its homeostasis, while NF-κB participates in a degenerative cycle where Aβ would feed its own production under pathological conditions.
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Affiliation(s)
- Linda Chami
- From the Équipe Labellisée “Fondation pour la Recherche Médicale” and “Excellence Laboratory Distalz”, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNSA, 660 Route des Lucioles, 06560, Valbonne, France and
| | - Virginie Buggia-Prévot
- From the Équipe Labellisée “Fondation pour la Recherche Médicale” and “Excellence Laboratory Distalz”, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNSA, 660 Route des Lucioles, 06560, Valbonne, France and
| | - Eric Duplan
- From the Équipe Labellisée “Fondation pour la Recherche Médicale” and “Excellence Laboratory Distalz”, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNSA, 660 Route des Lucioles, 06560, Valbonne, France and
| | - Dolores Delprete
- From the Équipe Labellisée “Fondation pour la Recherche Médicale” and “Excellence Laboratory Distalz”, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNSA, 660 Route des Lucioles, 06560, Valbonne, France and
| | - Mounia Chami
- From the Équipe Labellisée “Fondation pour la Recherche Médicale” and “Excellence Laboratory Distalz”, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNSA, 660 Route des Lucioles, 06560, Valbonne, France and
| | - Jean-François Peyron
- the Centre Méditerranéen de Médecine Moléculaire, UMR INSERM U895/UNS, 151 route Saint Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex 3, France
| | - Frédéric Checler
- From the Équipe Labellisée “Fondation pour la Recherche Médicale” and “Excellence Laboratory Distalz”, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNSA, 660 Route des Lucioles, 06560, Valbonne, France and
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Ferretti MT, Allard S, Partridge V, Ducatenzeiler A, Cuello AC. Minocycline corrects early, pre-plaque neuroinflammation and inhibits BACE-1 in a transgenic model of Alzheimer's disease-like amyloid pathology. J Neuroinflammation 2012; 9:62. [PMID: 22472085 PMCID: PMC3352127 DOI: 10.1186/1742-2094-9-62] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 04/02/2012] [Indexed: 12/20/2022] Open
Abstract
Background A growing body of evidence indicates that inflammation is one of the earliest neuropathological events in Alzheimer's disease. Accordingly, we have recently shown the occurrence of an early, pro-inflammatory reaction in the hippocampus of young, three-month-old transgenic McGill-Thy1-APP mice in the absence of amyloid plaques but associated with intracellular accumulation of amyloid beta petide oligomers. The role of such a pro-inflammatory process in the progression of the pathology remained to be elucidated. Methods and results To clarify this we administered minocycline, a tetracyclic derivative with anti-inflammatory and neuroprotective properties, to young, pre-plaque McGill-Thy1-APP mice for one month. The treatment ended at the age of three months, when the mice were still devoid of plaques. Minocycline treatment corrected the up-regulation of inducible nitric oxide synthase and cyclooxygenase-2 observed in young transgenic placebo mice. Furthermore, the down-regulation of inflammatory markers correlated with a reduction in amyloid precursor protein levels and amyloid precursor protein-related products. Beta-site amyloid precursor protein cleaving enzyme 1 activity and levels were found to be up-regulated in transgenic placebo mice, while minocycline treatment restored these levels to normality. The anti-inflammatory and beta-secretase 1 effects could be partly explained by the inhibition of the nuclear factor kappa B pathway. Conclusions Our study suggests that the pharmacological modulation of neuroinflammation might represent a promising approach for preventing or delaying the development of Alzheimer's disease neuropathology at its initial, pre-clinical stages. The results open new vistas to the interplay between inflammation and amyloid pathology.
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Affiliation(s)
- Maria Teresa Ferretti
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, Montreal, QC H3G 1Y6, Canada
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Lee YJ, Choi DY, Choi IS, Kim KH, Kim YH, Kim HM, Lee K, Cho WG, Jung JK, Han SB, Han JY, Nam SY, Yun YW, Jeong JH, Oh KW, Hong JT. Inhibitory effect of 4-O-methylhonokiol on lipopolysaccharide-induced neuroinflammation, amyloidogenesis and memory impairment via inhibition of nuclear factor-kappaB in vitro and in vivo models. J Neuroinflammation 2012; 9:35. [PMID: 22339795 PMCID: PMC3323460 DOI: 10.1186/1742-2094-9-35] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 02/19/2012] [Indexed: 12/26/2022] Open
Abstract
Background Neuroinflammation is important in the pathogenesis and progression of Alzheimer disease (AD). Previously, we demonstrated that lipopolysaccharide (LPS)-induced neuroinflammation caused memory impairments. In the present study, we investigated the possible preventive effects of 4-O-methylhonokiol, a constituent of Magnolia officinalis, on memory deficiency caused by LPS, along with the underlying mechanisms. Methods We investigated whether 4-O-methylhonokiol (0.5 and 1 mg/kg in 0.05% ethanol) prevents memory dysfunction and amyloidogenesis on AD model mice by intraperitoneal LPS (250 μg/kg daily 7 times) injection. In addition, LPS-treated cultured astrocytes and microglial BV-2 cells were investigated for anti-neuroinflammatory and anti-amyloidogenic effect of 4-O-methylhonkiol (0.5, 1 and 2 μM). Results Oral administration of 4-O-methylhonokiol ameliorated LPS-induced memory impairment in a dose-dependent manner. In addition, 4-O-methylhonokiol prevented the LPS-induced expression of inflammatory proteins; inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as activation of astrocytes (expression of glial fibrillary acidic protein; GFAP) in the brain. In in vitro study, we also found that 4-O-methylhonokiol suppressed the expression of iNOS and COX-2 as well as the production of reactive oxygen species, nitric oxide, prostaglandin E2, tumor necrosis factor-α, and interleukin-1β in the LPS-stimulated cultured astrocytes. 4-O-methylhonokiol also inhibited transcriptional and DNA binding activity of NF-κB via inhibition of IκB degradation as well as p50 and p65 translocation into nucleus of the brain and cultured astrocytes. Consistent with the inhibitory effect on neuroinflammation, 4-O-methylhonokiol inhibited LPS-induced Aβ1-42 generation, β- and γ-secretase activities, and expression of amyloid precursor protein (APP), BACE1 and C99 as well as activation of astrocytes and neuronal cell death in the brain, in cultured astrocytes and in microglial BV-2 cells. Conclusion These results suggest that 4-O-methylhonokiol inhibits LPS-induced amyloidogenesis via anti-inflammatory mechanisms. Thus, 4-O-methylhonokiol can be a useful agent against neuroinflammation-associated development or the progression of AD.
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Affiliation(s)
- Young-Jung Lee
- College of Pharmacy, Chungbuk National University, 12, Gaeshin-dong, Heungduk-gu, Cheongju, Chungbuk 361-763, Korea
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25
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Lee YJ, Choi DY, Choi IS, Han JY, Jeong HS, Han SB, Oh KW, Hong JT. Inhibitory effect of a tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl)-2-butenal on amyloid-β generation and inflammatory reactions via inhibition of NF-κB and STAT3 activation in cultured astrocytes and microglial BV-2 cells. J Neuroinflammation 2011; 8:132. [PMID: 21982455 PMCID: PMC3207974 DOI: 10.1186/1742-2094-8-132] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Accepted: 10/07/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Amyloidogenesis is linked to neuroinflammation. The tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl)-2-butenal, possesses anti-inflammatory properties in cultured macrophages, and in an arthritis animal model. Because astrocytes and microglia are responsible for amyloidogenesis and inflammatory reactions in the brain, we investigated the anti-inflammatory and anti-amyloidogenic effects of 2,4-bis(p-hydroxyphenyl)-2-butenal in lipopolysaccharide (LPS)-stimulated astrocytes and microglial BV-2 cells. METHODS Cultured astrocytes and microglial BV-2 cells were treated with LPS (1 μg/ml) for 24 h, in the presence (1, 2, 5 μM) or absence of 2,4-bis(p-hydroxyphenyl)-2-butenal, and harvested. We performed molecular biological analyses to determine the levels of inflammatory and amyloid-related proteins and molecules, cytokines, Aβ, and secretases activity. Nuclear factor-kappa B (NF-κB) DNA binding activity was determined using gel mobility shift assays. RESULTS We found that 2,4-bis(p-hydroxyphenyl)-2-butenal (1, 2, 5 μM) suppresses the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as the production of nitric oxide (NO), reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in LPS (1 μg/ml)-stimulated astrocytes and microglial BV-2 cells. Further, 2,4-bis(p-hydroxyphenyl)-2-butenal inhibited the transcriptional and DNA binding activity of NF-κB--a transcription factor that regulates genes involved in neuroinflammation and amyloidogenesis via inhibition of IκB degradation as well as nuclear translocation of p50 and p65. Consistent with the inhibitory effect on inflammatory reactions, 2,4-bis(p-hydroxyphenyl)-2-butenal inhibited LPS-elevated Aβ42 levels through attenuation of β- and γ-secretase activities. Moreover, studies using signal transducer and activator of transcription 3 (STAT3) siRNA and a pharmacological inhibitor showed that 2,4-bis(p-hydroxyphenyl)-2-butenal inhibits LPS-induced activation of STAT3. CONCLUSIONS These results indicate that 2,4-bis(p-hydroxyphenyl)-2-butenal inhibits neuroinflammatory reactions and amyloidogenesis through inhibition of NF-κB and STAT3 activation, and suggest that 2,4-bis(p-hydroxyphenyl)-2-butenal may be useful for the treatment of neuroinflammatory diseases like Alzheimer's disease.
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Affiliation(s)
- Young-Jung Lee
- College of Pharmacy, Chungbuk National University, 12 Gaesin-dong, Heungduk-gu, Cheongju, Chungbuk 361-763, Korea
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The Alzheimer's amyloid β-peptide (Aβ) binds a specific DNA Aβ-interacting domain (AβID) in the APP, BACE1, and APOE promoters in a sequence-specific manner: characterizing a new regulatory motif. Gene 2011; 488:1-12. [PMID: 21699964 DOI: 10.1016/j.gene.2011.06.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 06/01/2011] [Accepted: 06/06/2011] [Indexed: 11/23/2022]
Abstract
Deposition of extracellular plaques, primarily consisting of amyloid β peptide (Aβ), in the brain is the confirmatory diagnostic of Alzheimer's disease (AD); however, the physiological and pathological role of Aβ is not fully understood. Herein, we demonstrate novel Aβ activity as a putative transcription factor upon AD-associated genes. We used oligomers from 5'-flanking regions of the apolipoprotein E (APOE), Aβ-precursor protein (APP) and β-amyloid site cleaving enzyme-1 (BACE1) genes for electrophoretic mobility shift assay (EMSA) with different fragments of the Aβ peptide. Our results suggest that Aβ bound to an Aβ-interacting domain (AβID) with a consensus of "KGGRKTGGGG". This peptide-DNA interaction was sequence specific, and mutation of the first "G" of the decamer's terminal "GGGG" eliminated peptide-DNA interaction. Furthermore, the cytotoxic Aβ25-35 fragment had greatest DNA affinity. Such specificity of binding suggests that the AβID is worth of further investigation as a site wherein the Aβ peptide may act as a transcription factor.
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Hao W, Liu Y, Liu S, Walter S, Grimm MO, Kiliaan AJ, Penke B, Hartmann T, Rübe CE, Menger MD, Fassbender K. Myeloid differentiation factor 88-deficient bone marrow cells improve Alzheimer's disease-related symptoms and pathology. ACTA ACUST UNITED AC 2010; 134:278-92. [PMID: 21115468 DOI: 10.1093/brain/awq325] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Alzheimer's disease is characterized by extracellular deposits of amyloid β peptide in the brain. Increasing evidence suggests that amyloid β peptide injures neurons both directly and indirectly by triggering neurotoxic innate immune responses. Myeloid differentiation factor 88 is the key signalling molecule downstream to most innate immune receptors crucial in inflammatory activation. For this reason, we investigated the effects of myeloid differentiation factor 88-deficient bone marrow cells on Alzheimer's disease-related symptoms and pathology by establishing bone marrow chimeric amyloid β peptide precursor transgenic mice, in which bone marrow cells differentiate into microglia and are recruited to amyloid β peptide deposits. We observed that myeloid differentiation factor 88-deficient bone marrow reconstruction reduced both inflammatory activation and amyloid β peptide burden in the brain. In addition, synaptophysin, a marker of neuronal integrity, was preserved and the expression of neuronal plasticity-related genes, ARC and NMDA-R1, was increased. Thus, myeloid differentiation factor 88-deficient microglia significantly improved the cognitive function of amyloid β peptide precursor protein transgenic mice. Myeloid differentiation factor 88-deficiency enhanced amyloid β peptide phagocytosis by microglia/macrophages and blunted toxic inflammatory activation. Both the expression of amyloid β peptide precursor protein and amyloid β peptide degrading enzymes and also the efflux of amyloid β peptide from brain parenchyma were unaffected by myeloid differentiation factor 88-deficient microglia. By contrast, the activity of β-secretase was increased. β-Secretase is expressed primarily in neurons, with relatively little expression in astrocytes and microglia. Therefore, microglial replenishment with myeloid differentiation factor 88-deficient bone marrow cells might improve cognitive functions in Alzheimer's disease mouse models by enhancing amyloid β peptide phagocytosis and reducing inflammatory activation. These results could offer a new therapeutic option that might delay the progression of Alzheimer's disease.
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Affiliation(s)
- Wenlin Hao
- Department of Neurology, University of the Saarland, 66421 Homburg/Saar, Germany
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Golubov A, Yao Y, Maheshwari P, Bilichak A, Boyko A, Belzile F, Kovalchuk I. Microsatellite instability in Arabidopsis increases with plant development. PLANT PHYSIOLOGY 2010; 154:1415-27. [PMID: 20817752 PMCID: PMC2971617 DOI: 10.1104/pp.110.162933] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 08/24/2010] [Indexed: 05/23/2023]
Abstract
Plant development consists of the initial phase of intensive cell division followed by continuous genome endoreduplication, cell growth, and elongation. The maintenance of genome stability under these conditions is the main task performed by DNA repair and genome surveillance mechanisms. Our previous work showed that the rate of homologous recombination repair in older plants decreases. We hypothesized that this age-dependent decrease in the recombination rate is paralleled with other changes in DNA repair capacity. Here, we analyzed microsatellite stability using transgenic Arabidopsis (Arabidopsis thaliana) plants that carry the nonfunctional β-glucuronidase gene disrupted by microsatellite repeats. We found that microsatellite instability increased dramatically with plant age. We analyzed the contribution of various mechanisms to microsatellite instability, including replication errors and mistakes of DNA repair mechanisms such as mismatch repair, excision repair, and strand break repair. Analysis of total DNA polymerase activity using partially purified protein extracts showed an age-dependent decrease in activity and an increase in fidelity. Analysis of the steady-state RNA level of DNA replicative polymerases α, δ, Pol I-like A, and Pol I-like B and the expression of mutS homolog 2 (Msh2) and Msh6 showed an age-dependent decrease. An in vitro repair assay showed lower efficiency of nonhomologous end joining in older plants, paralleled by an increase in Ku70 gene expression. Thus, we assume that the more frequent involvement of nonhomologous end joining in strand break repair and the less efficient end-joining repair together with lower levels of mismatch repair activities may be the main contributors to the observed age-dependent increase in microsatellite instability.
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Spitzer P, Herrmann M, Klafki HW, Smirnov A, Lewczuk P, Kornhuber J, Wiltfang J, Maler JM. Phagocytosis and LPS alter the maturation state of β-amyloid precursor protein and induce different Aβ peptide release signatures in human mononuclear phagocytes. J Neuroinflammation 2010; 7:59. [PMID: 20929546 PMCID: PMC2958903 DOI: 10.1186/1742-2094-7-59] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 10/07/2010] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The classic neuritic β-amyloid plaque of Alzheimer's disease (AD) is typically associated with activated microglia and neuroinflammation. Similarly, cerebrovascular β-amyloid (Aβ) deposits are surrounded by perivascular macrophages. Both observations indicate a contribution of the mononuclear phagocyte system to the development of β-amyloid. METHODS Human CD14-positive mononuclear phagocytes were isolated from EDTA-anticoagulated blood by magnetic activated cell sorting. After a cultivation period of 72 hours in serum-free medium we assessed the protein levels of amyloid precursor protein (APP) as well as the patterns and the amounts of released Aβ peptides by ELISA or one-dimensional and two-dimensional urea-based SDS-PAGE followed by western immunoblotting. RESULTS We observed strong and significant increases in Aβ peptide release upon phagocytosis of acetylated low density lipoprotein (acLDL) or polystyrene beads and also after activation of the CD14/TLR4 pathway by stimulation with LPS. The proportion of released N-terminally truncated Aβ variants was increased after stimulation with polystyrene beads and acLDL but not after stimulation with LPS. Furthermore, strong shifts in the proportions of single Aβ1-40 and Aβ2-40 variants were detected resulting in a stimulus-specific Aβ signature. The increased release of Aβ peptides was accompanied by elevated levels of full length APP in the cells. The maturation state of APP was correlated with the release of N-terminally truncated Aβ peptides. CONCLUSIONS These findings indicate that mononuclear phagocytes potentially contribute to the various N-truncated Aβ variants found in AD β-amyloid plaques, especially under neuroinflammatory conditions.
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Affiliation(s)
- Philipp Spitzer
- Department of Psychiatry and Psychotherapy, University of Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
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Hjorth E, Frenkel D, Weiner H, Schultzberg M. Effects of immunomodulatory substances on phagocytosis of abeta(1-42) by human microglia. Int J Alzheimers Dis 2010; 2010. [PMID: 20798889 PMCID: PMC2925296 DOI: 10.4061/2010/798424] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 02/24/2010] [Indexed: 01/24/2023] Open
Abstract
Glial activation and increased inflammation characterize neuropathology in Alzheimer's disease (AD). The aim was to develop a model for studying phagocytosis of beta-amyloid (Abeta) peptide by human microglia and to test effects thereupon by immunomodulatory substances. Human CHME3 microglia showed intracellular Abeta(1-42) colocalized with lysosome-associated membrane protein-2, indicating phagocytosis. This was increased by interferon-gamma, and to a lesser degree with Protollin, a proteosome-based adjuvant. Secretion of brain-derived neurotrophic factor (BDNF) was decreased by Abeta(1-42) and by interferon-gamma and interleukin-1beta. These cytokines, but not Abeta(1-42), stimulated interleukin-6 release. Microglia which phagocytosed Abeta(1-42) exhibited a higher degree of expression of interleukin-1 receptor type I and inducible nitric oxide synthase. In conclusion, we show that human microglia are able to phagocytose Abeta(1-42) and that this is associated with expression of inflammatory markers. Abeta(1-42) and interferon-gamma decreased BDNF secretion suggesting a new neuropathological role for Abeta(1-42) and the inflammation accompanying AD.
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Affiliation(s)
- Erik Hjorth
- Division of Neurodegeneration, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
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31
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Cardoso S, Oliveira C. Inhibition of NF-kB Renders Cells more Vulnerable to Apoptosis Induced by Amyloid ß Peptides. Free Radic Res 2009; 37:967-973. [DOI: 10.1080/10715760310001595757] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Sastre M, Walter J, Gentleman SM. Interactions between APP secretases and inflammatory mediators. J Neuroinflammation 2008; 5:25. [PMID: 18564425 PMCID: PMC2442055 DOI: 10.1186/1742-2094-5-25] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 06/18/2008] [Indexed: 02/08/2023] Open
Abstract
There is now a large body of evidence linking inflammation to Alzheimer's disease (AD). This association manifests itself neuropathologically in the presence of activated microglia and astrocytes around neuritic plaques and increased levels of inflammatory mediators in the brains of AD patients. It is considered that amyloid-β peptide (Aβ), which is derived from the processing of the longer amyloid precursor protein (APP), could be the most important stimulator of this response, and therefore determining the role of the different secretases involved in its generation is essential for a better understanding of the regulation of inflammation in AD. The finding that certain non-steroidal anti-inflammatory drugs (NSAIDs) can affect the processing of APP by inhibiting β- and γ-secretases, together with recent revelations that these enzymes may be regulated by inflammation, suggest that they could be an interesting target for anti-inflammatory drugs. In this review we will discuss some of these issues and the role of the secretases in inflammation, independent of their effect on Aβ formation.
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Affiliation(s)
- Magdalena Sastre
- Division of Neuroscience and Mental Health, Imperial College London, The Hammersmith Hospital, Du cane Road, London W12 0NN, UK.
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Jiang Q, Heneka M, Landreth GE. The role of peroxisome proliferator-activated receptor-gamma (PPARgamma) in Alzheimer's disease: therapeutic implications. CNS Drugs 2008; 22:1-14. [PMID: 18072811 DOI: 10.2165/00023210-200822010-00001] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease is a complex neurodegenerative disorder, with aging, genetic and environmental factors contributing to its development and progression. The complexity of Alzheimer's disease presents substantial challenges for the development of new therapeutic agents. Alzheimer's disease is typified by pathological depositions of beta-amyloid peptides and neurofibrillary tangles within the diseased brain. It has also been demonstrated to be associated with a significant microglia-mediated inflammatory component, dysregulated lipid homeostasis and regional deficits in glucose metabolism within the brain. The peroxisome proliferator-activated receptor-gamma (PPARgamma) is a prototypical ligand-activated nuclear receptor that coordinates lipid, glucose and energy metabolism, and is found in elevated levels in the brains of individuals with Alzheimer's disease. A recently appreciated physiological function of this type of receptor is its ability to modulate inflammatory responses. In animal models of Alzheimer's disease, PPARgamma agonist treatment results in the reduction of amyloid plaque burden, reduced inflammation and reversal of disease-related behavioural impairment. In a recent phase II clinical trial, the use of the PPARgamma agonist rosiglitazone was associated with improved cognition and memory in patients with mild to moderate Alzheimer's disease. Thus, PPARgamma may act to modulate multiple pathophysiological mechanisms that contribute to Alzheimer's disease, and represents an attractive therapeutic target for the treatment of the disease.
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Affiliation(s)
- Qingguang Jiang
- Department of Neurosciences, Alzheimer Research Laboratory, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Fisher L, Samuelsson M, Jiang Y, Ramberg V, Figueroa R, Hallberg E, Langel U, Iverfeldt K. Targeting cytokine expression in glial cells by cellular delivery of an NF-kappaB decoy. J Mol Neurosci 2008; 31:209-19. [PMID: 17726227 DOI: 10.1385/jmn:31:03:209] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 10/18/2006] [Accepted: 11/30/1999] [Indexed: 11/11/2022]
Abstract
Inhibition of nuclear factor (NF)-kappaB has emerged as an important strategy for design of anti-inflammatory therapies. In neurodegenerative disorders like Alzheimer's disease, inflammatory reactions mediated by glial cells are believed to promote disease progression. Here, we report that uptake of a double-stranded oligonucleotide NF-kappaB decoy in rat primary glial cells is clearly facilitated by noncovalent binding to a cell-penetrating peptide, transportan 10, via a complementary peptide nucleic acid (PNA) sequence. Fluorescently labeled oligonucleotide decoy was detected in the cells within 1 h only when cells were incubated with the decoy in the presence of cell-penetrating peptide. Cellular delivery of the decoy also inhibited effects induced by a neurotoxic fragment of the Alzheimer beta-amyloid peptide in the presence of the inflammatory cytokine interleukin (IL)-1beta. Pretreatment of the cells with the complex formed by the decoy and the cell-penetrating peptide-PNA resulted in 80% and 50% inhibition of the NF-kappaB binding activity and IL-6 mRNA expression, respectively.
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Affiliation(s)
- Linda Fisher
- Department of Neurochemistry, Stockholm University, SE10691 Stockholm, Sweden
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Abstract
Sporadic inclusion-body myositis (sIBM) is the most common acquired muscle disease in Caucasians over the age of 50 years. Pathologically it is marked by inflammatory, degenerative, and mitochondrial changes that interact in a yet-unknown way to cause progressive muscle degeneration and weakness. The cause of the disease is unknown, but it is thought to involve a complex interplay between environmental factors, genetic susceptibility, and aging. The strongest evidence for genetic susceptibility comes from studies of the major histocompatibility complex (MHC), where different combinations of alleles have been associated with sIBM in different ethnic groups. The rare occurrence of familial cases of inclusion-body myositis (fIBM) adds additional evidence for genetic susceptibility. Other candidate genes such as those encoding some of the proteins accumulating in muscle fibers have been investigated, with negative results. The increased understanding of related disorders, the hereditary inclusion-body myopathies (hIBM), may also provide clues to the underlying pathogenesis of sIBM, but to date there is no indication that the genes responsible for these conditions are involved in sIBM. This review summarizes current understanding of the contribution of genetic susceptibility factors to the development of sIBM.
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Affiliation(s)
- M Needham
- Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Level 4, A Block, Queen Elizabeth II Medical Centre, Nedlands, Western Australia 6009, Australia.
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Camandola S, Mattson MP. NF-kappa B as a therapeutic target in neurodegenerative diseases. Expert Opin Ther Targets 2007; 11:123-32. [PMID: 17227229 DOI: 10.1517/14728222.11.2.123] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
NF-kappaB is a transcription factor that regulates numerous physiological functions, and that is involved in the pathogenesis of various diseases. In the nervous system there is evidence supporting a dual role of NF-kappaB in neurodegenerative diseases; activation of NF-kappaB in neurons promotes their survival, whereas activation in glial and immune cells mediates pathological inflammatory processes. The reason for such a dichotomy lies in the complexity of the NF-kappaB system. Emerging research has begun to dissect the pathways leading to the activation of the different NF-kappaB proteins, and the gene targets of NF-kappaB, in cells of the nervous system. In this article the authors discuss recent findings concerning the roles of NF-kappaB in the pathogenesis of several neurodegenerative disorders, and its potential as a pharmaceutical target for these disorders.
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Affiliation(s)
- Simonetta Camandola
- Laboratory of Neurosciences, National Institute onAging, Intramural Research Program, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA.
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Transcriptional and translational regulation of BACE1 expression--implications for Alzheimer's disease. Prog Neurobiol 2006; 79:95-111. [PMID: 16904810 DOI: 10.1016/j.pneurobio.2006.06.001] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 06/08/2006] [Accepted: 06/09/2006] [Indexed: 01/07/2023]
Abstract
The proteolytical processing of the amyloid precursor protein (APP) gives rise to beta-amyloid peptides, which accumulate in brains of Alzheimer's disease (AD) patients. Different soluble or insoluble higher molecular weight forms of beta-amyloid peptides have been postulated to trigger a complex pathological cascade that may cause synaptic dysfunction, inflammatory processes, neuronal loss, cognitive impairment, and finally the onset of the disease. The generation of beta-amyloid peptides requires the proteolytical cleavage of APP by an aspartyl protease named beta-site APP-cleaving enzyme 1 (BACE1). The expression and enzymatic activity of BACE1 are increased in brains of AD patients. Here we discuss the importance of a number of recently identified transcription factors as well as post-transcriptional modifications and activation of intracellular signaling molecules for the regulation of BACE1 expression in brain. Importantly, some of these factors are known to be involved in the inflammatory and chronic stress responses of the brain, which are compromised during aging. Moreover, recent evidence indicates that beneficial effects of non-steriodal anti-inflammatory drugs on the progression of AD are mediated--at least in part--by effects on the peroxisome proliferator-activated receptor-gamma response element present in the BACE1 promoter. The identification of the cell type-specific expression and activation of NF-kappaB, Sp1 and YY1 transcription factors may provide a basis to specifically interfere with BACE1 expression and, thereby, to lower the concentrations of beta-amyloid peptides, which may prevent neuronal cell loss and cognitive decline in AD patients.
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Theuns J, Brouwers N, Engelborghs S, Sleegers K, Bogaerts V, Corsmit E, De Pooter T, van Duijn CM, De Deyn PP, Van Broeckhoven C. Promoter mutations that increase amyloid precursor-protein expression are associated with Alzheimer disease. Am J Hum Genet 2006; 78:936-46. [PMID: 16685645 PMCID: PMC1474091 DOI: 10.1086/504044] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 03/08/2006] [Indexed: 11/03/2022] Open
Abstract
Genetic variations in promoter sequences that alter gene expression play a prominent role in increasing susceptibility to complex diseases. Also, expression levels of APP are essentially regulated by its core promoter and 5' upstream regulatory region and correlate with amyloid beta levels in Alzheimer disease (AD) brains. Here, we systematically sequenced the proximal promoter (-766/+204) and two functional distal regions (-2634/-2159 and -2096/-1563) of APP in two independent AD series with onset ages < or =70 years (Belgian sample, n=180; Dutch sample, n=111) and identified eight novel sequence variants. Three mutations (-118C-->A, -369C-->G, and -534G-->A) identified only in patients with AD showed, in vitro, a nearly twofold neuron-specific increase in APP transcriptional activity, similar to what is expected from triplication of APP in Down syndrome. These mutations either abolished (AP-2 and HES-1) or created (Oct1) transcription-factor binding sites involved in the development and differentiation of neuronal systems. Also, two of these clustered in the 200-bp region (-540/-340) of the APP promoter that showed the highest degree of species conservation. The present study provides evidence that APP-promoter mutations that significantly increase APP expression levels are associated with AD.
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Affiliation(s)
- Jessie Theuns
- Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, University of Antwerp, Antwerpen, Belgium
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Kaltschmidt B, Widera D, Kaltschmidt C. Signaling via NF-κB in the nervous system. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1745:287-99. [PMID: 15993497 DOI: 10.1016/j.bbamcr.2005.05.009] [Citation(s) in RCA: 221] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 05/20/2005] [Accepted: 05/23/2005] [Indexed: 12/12/2022]
Abstract
Nuclear factor kappa B (NF-kappaB) is an inducible transcription factor present in neurons and glia. Recent genetic models identified a role for NF-kappaB in neuroprotection against various neurotoxins. Furthermore, genetic evidence for a role in learning and memory is now emerging. This review highlights our current understanding of neuronal NF-kappaB in response to synaptic transmission and summarizes potential physiological functions of NF-kappaB in the nervous system. This article contains a listing of NF-kappaB activators and inhibitors in the nervous system, furthermore specific target genes are discussed. Synaptic NF-kappaB activated by glutamate and Ca2+ will be presented in the context of retrograde signaling. A controversial role of NF-kappaB in neurodegenerative diseases will be discussed. A model is proposed explaining this paradox as deregulated physiological NF-kappaB activity, where novel results are integrated, showing that p65 could be turned from an activator to a repressor of anti-apoptotic genes.
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Affiliation(s)
- Barbara Kaltschmidt
- Institut für Neurobiochemie Universität Witten/Herdecke, Stockumer Street 10, D-58448 Witten, Germany
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Abstract
Members of the nuclear factor kappaB (NF-kappaB) family of transcription factors are activated within the CNS in pathological settings of apoptosis and neurological disease. Recent work using several model systems provides accumulating evidence that these transcription factors also participate in the regulation of neuronal activity-dependent transcription and behavior under physiological conditions. This review highlights advances in our understanding of the mechanisms of Ca(2+)-responsive activation and synaptic signaling to the nucleus by NF-kappaB transcription factors within the CNS, and the relevance of this transcription factor family for learning and memory.
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Affiliation(s)
- Mollie K Meffert
- Division of Biology, MC204-31 California Institute of Technology, Pasadena, CA 91125, USA.
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Clarimón J, Andrés AM, Bertranpetit J, Comas D. Comparative analysis of Alu insertion sequences in the APP 5' flanking region in humans and other primates. J Mol Evol 2004; 58:722-31. [PMID: 15461429 DOI: 10.1007/s00239-004-2594-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Overexpression of the amyloid precursor protein gene (APP) may play a role in the neuropathology of Alzheimer's disease. Therefore, elucidating the mechanisms involved in APP gene regulation is of primary importance, and various cis-acting regulatory elements located in 5' distal regions are known to play a main role. Some of them lie within Alu elements, one of which (Alu1) is only found in humans and apes while the other (Alu2) has a much older history and is also found in rhesus. These Alu insertions harbor sequence motifs that may act as cis-regulatory elements, which may cause differences in APP regulation among primate species and whose functionality may be ascertained through their conservation in a comparative analysis. We have performed a comparative analysis of the region comprising the two Alu elements of the APP promoter in several primates, including humans. We have found a significant decrease in nucleotide diversity in the Alu2 element (inserted in all the species analyzed) compared to the Alu1 (inserted only in apes). This finding can be interpreted as a constriction in the Alu2 sequence variation as a consequence of a functional role of this element in the APP expression. The present results suggest a wider extension of the regulatory elements than the known short consensus regulatory sequences. Moreover, the different conservation of two highly similar and neighboring sequences suggests that, besides the importance of the sequence motifs, their position in relation to the gene suggests that they have played a role in being recruited as regulatory elements.
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Affiliation(s)
- Jordi Clarimón
- Unitat de Biologia Evolutiva, Facultat de Ciències de la Salut i de la Vida, Universitat Pompeu Fabra, C/ Doctor Aiguader 80, Barcelona, 08003, Catalonia, Spain
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Rebelo S, Henriques AG, da Cruz e Silva EF, da Cruz e Silva OAB. Effect of cell density on intracellular levels of the Alzheimer's amyloid precursor protein. J Neurosci Res 2004; 76:406-14. [PMID: 15079870 DOI: 10.1002/jnr.20091] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The precise function of APP (Alzheimer's amyloid precursor protein) remains to be fully elucidated, but various lines of evidence suggest that it may be involved in cell adhesion processes. Because APP is a transmembrane glycoprotein, variations in its expression level may have direct bearing on its putative role in cell adhesion. Our results revealed that although APP levels did not change markedly with increasing cell density (ICD), there was a small but reproducible increase in APP expression at subconfluent conditions. Higher expression APP levels led to corresponding increases in the amount of APP processed and secreted APP (sAPP) released into the cell media. Given that phorbol esters stimulate the non-amyloidogenic pathway at the expense of reducing production of Abeta (the peptide found deposited as neuritic plaques in the brains of patients with Alzheimer's disease), thus providing an interesting therapeutic focus, we tested the effect of the phorbol 12-myristate 13-acetate (PMA) on APP processing at ICD. PMA not only stimulated sAPP release at all densities tested, but also produced a corresponding decrease in the intracellular levels of APP. Further experimentation revealed that increased APP expression with ICD was dependent on factors present in conditioned medium. Interestingly, exposing cells to the Abeta peptide itself could mimic these results, thus providing evidence for a potential positive feedback mechanism between Abeta production and intracellular APP levels.
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Affiliation(s)
- Sandra Rebelo
- Centro de Biologia Celular, Universidade de Aveiro, Aveiro, Portugal
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Adlerz L, Beckman M, Holback S, Tehranian R, Cortés Toro V, Iverfeldt K. Accumulation of the amyloid precursor-like protein APLP2 and reduction of APLP1 in retinoic acid-differentiated human neuroblastoma cells upon curcumin-induced neurite retraction. ACTA ACUST UNITED AC 2003; 119:62-72. [PMID: 14597230 DOI: 10.1016/j.molbrainres.2003.08.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Amyloid precursor protein (APP) belongs to a conserved gene family, also including the amyloid precursor-like proteins, APLP1 and APLP2. The function of these three proteins is not yet fully understood. One of the proposed roles of APP is to promote neurite outgrowth. The aim of this study was to investigate the regulation of the expression levels of APP family members during neurite outgrowth. We observed that retinoic acid (RA)-induced neuronal differentiation of human SH-SY5Y cells resulted in increased expression of APP, APLP1 and APLP2. We also examined the effect of the NFkappaB, AP-1 and c-Jun N-terminal kinase inhibitor curcumin (diferuloylmethane) on the RA-induced expression levels of these proteins. We found that treatment with curcumin counteracted the RA-induced mRNA expression of all APP family members. In addition, we observed that curcumin treatment resulted in neurite retraction without any effect on cell viability. Surprisingly, curcumin had differential effects on the APLP protein levels in RA-differentiated cells. RA-induced APLP1 protein expression was blocked by curcumin, while the APLP2 protein levels were further increased. APP protein levels were not affected by curcumin treatment. We propose that the sustained levels of APP and the elevated levels of APLP2, in spite of the reduced mRNA expression, are due to altered proteolytic processing of these proteins. Furthermore, our results suggest that APLP1 does not undergo the same type of regulated processing as APP and APLP2.
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Affiliation(s)
- Linda Adlerz
- Department of Neurochemistry and Neurotoxicology, Stockholm University, SE-10691 Stockholm, Sweden
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Lange-Dohna C, Zeitschel U, Gaunitz F, Perez-Polo JR, Bigl V, Rossner S. Cloning and expression of the rat BACE1 promoter. J Neurosci Res 2003; 73:73-80. [PMID: 12815710 DOI: 10.1002/jnr.10639] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The pathogenic processing of the amyloid precursor protein (APP) into beta-amyloid peptides, which give rise to beta-amyloid plaques in the brains of Alzheimer's disease patients, requires the enzymatic activity of the beta-site APP-cleaving enzyme 1 (BACE1). We report the cloning and sequence of a 1.5-kb DNA fragment upstream of the coding sequence of the rat BACE1 gene and the construction of a BACE1 promoter/luciferase reporter construct. The basal activity of this promoter construct was highest in neuronal cell lines such as BE(2)-C and PC12 and in the pancreatic cell line AR42J, somewhat lower in rat primary neurons, and astrocytic and microglial cultures, very low in hepatocytes, and almost absent in fibroblasts and in the monocyte-macrophage cell line RAW264.7. The first 600 bp of this promoter are highly conserved among rat, mouse, and human, suggesting that this region contains regulatory elements that modulate BACE1 transcription. Indeed, this fragment contains several putative transcription factor binding sites such as MZF1, Sp1, four GATA-1 sites, and one YY1 site. Directed mutagenesis of GATA-1 elements led to altered luciferase expression, indicating that these sites are involved in the regulation of BACE1 transcription. Additionally, the analysis of promoter activities of deletion mutants suggests the presence of activators of BACE1 transcription between bases -514 to -753 and of suppressor elements between bases -754 and -1541. The BACE1 promoter sequence data and the constructs described here will be useful to identify factors that influence the expression of BACE1 in experimental paradigms in vitro.
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Chen Y, Liu W, Naumovski L, Neve RL. ASPP2 inhibits APP-BP1-mediated NEDD8 conjugation to cullin-1 and decreases APP-BP1-induced cell proliferation and neuronal apoptosis. J Neurochem 2003; 85:801-9. [PMID: 12694406 DOI: 10.1046/j.1471-4159.2003.01727.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
APP-BP1, first identified as a protein that interacts with the carboxyl (C) terminus of the amyloid precursor protein (APP), is one-half of the bipartite activating enzyme for the ubiquitin-like protein NEDD8. We report here that APP-BP1 also specifically interacts with apoptosis stimulating protein of p53 ASPP2 in non-transfected cells through the functional predominant N-terminal domain ASPP2(332-483). ASPP2 inhibits the ability of APP-BP1 to rescue the ts41 cell cycle mutation and inhibits APP-BP1 induced apoptosis in primary neurons. ASPP2 reduces the ability of NEDD8 to conjugate to Cullin-1, inhibits APP-BP1-dependent ts41 cell proliferation, and blocks the ability of APP-BP1 to cause apoptosis and to cause DNA synthesis in neurons. We also show that ASPP2 activates nuclear factor-kappaB (NF-kappaB) transcriptional activity, which seems to be inhibited by the neddylation pathway since the dominant negative NEDD8 activating enzyme causes enhanced NF-kappaB activity. Our data provide the first in vivo evidence that ASPP2 is a negative regulator of the neddylation pathway through specific interaction with APP-BP1 and suggest that dysfunction of the APP-BP1 interaction with APP may be one cause of Alzheimer's disease.
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Affiliation(s)
- Yuzhi Chen
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, Massachusetts, USA.
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Fiorentini C, Guerra N, Facchetti M, Finardi A, Tiberio L, Schiaffonati L, Spano P, Missale C. Nerve growth factor regulates dopamine D(2) receptor expression in prolactinoma cell lines via p75(NGFR)-mediated activation of nuclear factor-kappaB. Mol Endocrinol 2002; 16:353-66. [PMID: 11818506 DOI: 10.1210/mend.16.2.0773] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Two groups of prolactinoma cell lines were identified. One group (responder) expresses both D(2) dopamine receptors and an autocrine loop mediated by nerve growth factor (NGF) and one group (nonresponder) lacks both D(2) receptors and NGF production. D(2) receptor expression in these cell lines is dependent on NGF. Indeed, NGF inactivation in responder cells decreases D(2) receptor density, while NGF treatment induces D(2) receptor expression in nonresponders. Here we show that inactivation of p75(NGFR), but not of trkA, resulted in D(2) receptor loss in responder cells and prevented D(2) receptor expression induced by NGF in the nonresponder. Analysis of nuclear factor-kappaB (NF-kappaB) nuclear accumulation and binding to corresponding DNA consensus sequences indicated that in NGF-secreting responder cells, but not in nonresponders, NF-kappaB is constitutively activated. Moreover, NGF treatment of nonresponder cells induced both nuclear translocation and DNA binding activity of NF-kappaB complexes containing p50, p65/RelA, and cRel subunits, an effect prevented by anti-p75(NGFR) antibodies. Disruption of NF-kappaB nuclear translocation by SN50 remarkably impaired D(2) receptor expression in responder cells and prevented D(2) gene expression induced by NGF in nonresponders. These data indicate that in prolactinoma cells the effect of NGF on D(2) receptor expression is mediated by p75(NGFR) in a trkA-independent way and that NGF stimulation of p75(NGFR) activates NF-kappaB, which is required for D(2) gene expression. We thus suggest that NF-kappaB is a key transcriptional regulator of the D(2) gene and that this mechanism may not be confined to pituitary tumors, but could also extend to other dopaminergic systems.
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Affiliation(s)
- Chiara Fiorentini
- Division of Pharmacology, Department of Biomedical Sciences and Biotechnology, University of Brescia, 25123 Brescia, Italy
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Ravati A, Ahlemeyer B, Becker A, Klumpp S, Krieglstein J. Preconditioning-induced neuroprotection is mediated by reactive oxygen species and activation of the transcription factor nuclear factor-kappaB. J Neurochem 2001; 78:909-19. [PMID: 11520911 DOI: 10.1046/j.1471-4159.2001.00463.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Preconditioning by a sublethal stimulus induces tolerance to a subsequent, otherwise lethal insult and it has been suggested that reactive oxygen species (ROS) are involved in this phenomenon. In the present study, we determined whether preconditioning activates the transcription factor nuclear factor-kappaB (NF-kappaB) and how this activation contributes to preconditioning-induced inhibition of neuronal apoptosis. Preconditioning was performed by incubating mixed cultures of neurons and astrocytes from neonatal rat hippocampus with xanthine/xanthine oxidase or FeSO4 for 15 min followed by 24 h of recovery which protected the neurons against subsequent staurosporine-induced (200 nM, 24 h) apoptosis. The cellular ROS content increased during preconditioning, but returned to basal levels after removal of xanthine/xanthine oxidase or FeSO4. We detected a transient activation of NF-kappaB 4 h after preconditioning as shown by immunocytochemistry, by a decrease in the protein level of IkappaBalpha as well as by electrophoretic mobility shift assay. Preconditioning-mediated neuroprotection was abolished by antioxidants, inhibitors of NF-kappaB activation and cycloheximide suggesting the involvement of ROS, an activation of NF-kappaB and de novo protein synthesis in preconditioning-mediated rescue pathways. Furthermore, preconditioning increased the protein level of Mn-superoxide dismutase which could be blocked by antioxidants, cycloheximide and kappaB decoy DNA. Our data suggest that inhibition of staurosporine-induced neuronal apoptosis by preconditioning with xanthine/xanthine oxidase or FeSO4 involves an activation of NF-kappaB and an increase in the protein level of Mn-superoxide dismutase.
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Affiliation(s)
- A Ravati
- Institut für Pharmakologie und Toxikologie, Fachbereich Pharmazie der Philipps-Universität Marburg, Marburg, Germany
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Abstract
The amyloid precursor protein (APP) gene and its protein products have multiple functions in the central nervous system and fulfil criteria as neuractive peptides: presence, release and identity of action. There is increased understanding of the role of secretases (proteases) in the metabolism of APP and the production of its peptide fragments. The APP gene and its products have physiological roles in synaptic action, development of the brain, and in the response to stress and injury. These functions reveal the strategic importance of APP in the workings of the brain and point to its evolutionary significance.
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Affiliation(s)
- P K Panegyres
- Department of Neuropathology, Royal Perth Hospital, Western Australia.
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Denk A, Wirth T, Baumann B. NF-kappaB transcription factors: critical regulators of hematopoiesis and neuronal survival. Cytokine Growth Factor Rev 2000; 11:303-20. [PMID: 10959078 DOI: 10.1016/s1359-6101(00)00009-5] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Rel/NF-kappaB family of transcription factors has been implicated in the regulation of genes involved in immune and inflammatory responses, and of processes such as cell survival, apoptosis, development, differentiation, cell growth and neoplastic transformation. In this report we will summarize recent findings which highlight critical roles of NF-kappaB in different processes in hematopoietic and neuronal cells.
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Affiliation(s)
- A Denk
- Department of Physiological Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
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Lahiri DK, Nall C, Ge YW. Promoter activity of the beta-amyloid precursor protein gene is negatively modulated by an upstream regulatory element. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1999; 71:32-41. [PMID: 10407184 DOI: 10.1016/s0169-328x(99)00150-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Alzheimer's disease (AD) is characterized by the aggregation of the amyloid beta-peptide (Abeta) which is generated from a larger beta-amyloid precursor protein (betaAPP). An overexpression of the betaAPP gene in certain areas of the AD brain has been suggested to be an important factor in the neuropathology of AD. Here we have further characterized an upstream regulatory element (URE) located between -2257 and -2234 of the human betaAPP promoter. In addition to its location in the promoter, BLAST search reveals that URE is present in several introns of the betaAPP gene and is also detected in many other genes. For functional studies, two promoter regions were cloned upstream of the reporter gene, chloramphenicol acetyl transferase (CAT): (i) phbetaE-B - the plasmid that contains the human (h) promoter region (-2832 to +101) including URE, and (ii) prhbetaE-B - the plasmid that contains the rhesus (rh) promoter region excluding URE as it lacks a 270 bp region of the hbetaAPP promoter (-2435 to -2165). Transient transfection studies indicate that phbetaE-B displayed significantly less CAT-promoter activity than prhbetaE-B in C6, PC12 and SK-N-SH cells. To determine the role of URE in a heterologous promoter, a pbetaURE construct was made by subcloning URE in an enhancerless promoter vector pCATP. The pbetaURE-CAT construct displayed threefold to fourfold less promoter activity than pCATP when different cell lines were transfected with the plasmids. URE interacts with a novel protein(s) as determined by the electrophoretic mobility shift assay (EMSA). Although the core DNA region of URE resembles with the NF-kB element, URE-binding protein is not related to the NF-kB transcription factor. When EMSA was performed with specific competitors in different cell lines, the labeled URE probe was not competed by the oligonucleotides specific for either the AP3, NF-1 or NF-kB transcription factor. The migration of the URE-protein complex was different from the NF-kB-protein complex in the EMSA gel. A distinct URE-specific nuclear factor was also detected in frontal cortex of a normal human brain. These results suggest that the URE region acts as a repressor element, that the URE-binding protein is not related to the known transcription factors tested, and that the protein is present in astrocytic, neuroblastoma, PC12 cells and in the human brain.
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Affiliation(s)
- D K Lahiri
- Laboratory of Molecular Neurogenetics, Institute of Psychiatric Research, Department of Psychiatry and of Medical and Molecular Genetics, Room No. PR-313, 791 Union Drive, Indiana University School of Medicine, Indianapolis, IN 46202-488.
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