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Huang X, Fowler C, Li Y, Li QX, Sun J, Pan Y, Jin L, Perez KA, Dubois C, Lim YY, Drysdale C, Rumble RL, Chinnery HR, Rowe CC, Martins RN, Maruff P, Doecke JD, Lin Y, Belaidi AA, Barnham KJ, Masters CL, Gu BJ. Clearance and transport of amyloid β by peripheral monocytes correlate with Alzheimer's disease progression. Nat Commun 2024; 15:7998. [PMID: 39266542 PMCID: PMC11393069 DOI: 10.1038/s41467-024-52396-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 09/02/2024] [Indexed: 09/14/2024] Open
Abstract
Impaired clearance of amyloid β (Aβ) in late-onset Alzheimer's disease (AD) affects disease progression. The role of peripheral monocytes in Aβ clearance from the central nervous system (CNS) is unclear. We use a flow cytometry assay to identify Aβ-binding monocytes in blood, validated by confocal microscopy, Western blotting, and mass spectrometry. Flow cytometry immunophenotyping and correlation with AD biomarkers are studied in 150 participants from the AIBL study. We also examine monocytes in human cerebrospinal fluid (CSF) and their migration in an APP/PS1 mouse model. The assay reveals macrophage-like Aβ-binding monocytes with high phagocytic potential in both the periphery and CNS. We find lower surface Aβ levels in mild cognitive impairment (MCI) and AD-dementia patients compared to cognitively unimpaired individuals. Monocyte infiltration from blood to CSF and migration from CNS to peripheral lymph nodes and blood are observed. Here we show that Aβ-binding monocytes may play a role in CNS Aβ clearance, suggesting their potential as a biomarker for AD diagnosis and monitoring.
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Affiliation(s)
- Xin Huang
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
- The Innate Phagocytosis Laboratory, Level 11, Melbourne, Victoria, Australia
| | - Chris Fowler
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Yihan Li
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Qiao-Xin Li
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
- National Dementia Diagnostics Laboratory, The University of Melbourne, Parkville, VIC, Australia
| | - Jiaqi Sun
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Yijun Pan
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Liang Jin
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Keyla A Perez
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Céline Dubois
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Yen Y Lim
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - Candace Drysdale
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Rebecca L Rumble
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Holly R Chinnery
- Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Lions Eye Institute, Perth, Western Australia, Australia
- Optometry, School of Allied Health, The University of Western Australia, Perth, Australia
| | - Christopher C Rowe
- Department of Nuclear Medicine and Center for PET, Austin Health, Heidelberg, VIC, Australia
| | - Ralph N Martins
- Center of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia
| | - Paul Maruff
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
- Cogstate Ltd., Melbourne, VIC, Australia
| | - James D Doecke
- Health and Biosecurity, Australian E-Health Research Center, CSIRO, Brisbane, QLD, Australia
| | - Yong Lin
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Abdel A Belaidi
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Kevin J Barnham
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Colin L Masters
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia.
| | - Ben J Gu
- The Florey Institute, The University of Melbourne, Parkville, VIC, Australia.
- The Innate Phagocytosis Laboratory, Level 11, Melbourne, Victoria, Australia.
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China.
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Wang X, Xie Y, Fan X, Wu X, Wang D, Zhu L. Intermittent hypoxia training enhances Aβ endocytosis by plaque associated microglia via VPS35-dependent TREM2 recycling in murine Alzheimer's disease. Alzheimers Res Ther 2024; 16:121. [PMID: 38831312 PMCID: PMC11145795 DOI: 10.1186/s13195-024-01489-6] [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: 02/06/2024] [Accepted: 05/27/2024] [Indexed: 06/05/2024]
Abstract
BACKGROUND Beta-amyloid (Aβ) deposition in the brain parenchyma is a crucial initiating step in the amyloid cascade hypothesis of Alzheimer's disease (AD) pathology. Furthermore, dysfunction of plaque-associated microglia, also known as disease-associated microglia (DAM) has been reported to accelerate Aβ deposition and cognitive impairment. Our previous research demonstrated that intermittent hypoxia training (IHT) improved AD pathology by upregulating autophagy in DAM, thereby enhancing oligomeric Aβ (oAβ) clearance. Considering that oAβ internalization is the initial stage of oAβ clearance, this study focused on the IHT mechanism involved in upregulating Aβ uptake by DAM. METHODS IHT was administered to 8-month-old APP/PS1 mice or 6-month-old microglial vacuolar protein sorting 35 (VPS35) knockout mice in APP/PS1 background (MG VPS35 KO: APP/PS1) for 28 days. After the IHT, the spatial learning-memory capacity of the mice was assessed. Additionally, AD pathology was determined by estimating the nerve fiber and synapse density, Aβ plaque deposition, and Aβ load in the brain. A model of Aβ-exposed microglia was constructed and treated with IHT to explore the related mechanism. Finally, triggering receptor expressed on myeloid cells 2 (TREM2) intracellular recycling and Aβ internalization were measured using a fluorescence tracing technique. RESULTS Our results showed that IHT ameliorated cognitive function and Aβ pathology. In particular, IHT enhanced Aβ endocytosis by augmenting the intracellular transport function of microglial TREM2, thereby contributing to Aβ clearance. Furthermore, IHT specifically upregulated VPS35 in DAM, the primary cause for the enhanced intracellular recycling of TREM2. IHT lost ameliorative effect on Aβ pathology in MG VPS35 KO: APP/PS1 mice brain. Lastly, the IHT mechanism of VPS35 upregulation in DAM was mediated by the transcriptional regulation of VPS35 by transcription factor EB (TFEB). CONCLUSION IHT enhances Aβ endocytosis in DAM by upregulating VPS35-dependent TREM2 recycling, thereby facilitating oAβ clearance and mitigation of Aβ pathology. Moreover, the transcriptional regulation of VPS35 by TFEB demonstrates a close link between endocytosis and autophagy in microglia. Our study further elucidates the IHT mechanism in improving AD pathology and provides evidence supporting the potential application of IHT as a complementary therapy for AD.
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Affiliation(s)
- Xueting Wang
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China.
| | - Yuqi Xie
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Xiaoyang Fan
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Xiaomei Wu
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Dan Wang
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Li Zhu
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China.
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Zhang C, Tan R, Zhou X, Wang R, Wang X, Ma R, Chu F, Li Y, Yin T, Liu Z. Transcranial Magneto-Acoustic Stimulation Protects Synaptic Rehabilitation from Amyloid-Beta Plaques via Regulation of Microglial Functions. Int J Mol Sci 2024; 25:4651. [PMID: 38731870 PMCID: PMC11083601 DOI: 10.3390/ijms25094651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/03/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
Transcranial magneto-acoustic stimulation (TMAS), which is characterized by high spatiotemporal resolution and high penetrability, is a non-invasive neuromodulation technology based on the magnetic-acoustic coupling effect. To reveal the effects of TMAS treatment on amyloid-beta (Aβ) plaque and synaptic plasticity in Alzheimer's disease, we conducted a comparative analysis of TMAS and transcranial ultrasound stimulation (TUS) based on acoustic effects in 5xFAD mice and BV2 microglia cells. We found that the TMAS-TUS treatment effectively reduced amyloid plaque loads and plaque-associated neurotoxicity. Additionally, TMAS-TUS treatment ameliorated impairments in long-term memory formation and long-term potentiation. Moreover, TMAS-TUS treatment stimulated microglial proliferation and migration while enhancing the phagocytosis and clearance of Aβ. In 5xFAD mice with induced microglial exhaustion, TMAS-TUS treatment-mediated Aβ plaque reduction, synaptic rehabilitation improvement, and the increase in phospho-AKT levels were diminished. Overall, our study highlights that stimulation of hippocampal microglia by TMAS treatment can induce anti-cognitive impairment effects via PI3K-AKT signaling, providing hope for the development of new strategies for an adjuvant therapy for Alzheimer's disease.
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Affiliation(s)
- Chunlan Zhang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Ruxin Tan
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Xiaoqing Zhou
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Ruru Wang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Xin Wang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Ren Ma
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
- Tianjin Institutes of Health Science, Tianjin 301600, China
| | - Fangxuan Chu
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Ying Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Tao Yin
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
| | - Zhipeng Liu
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, 236# Baidi Road, Tianjin 300192, China; (C.Z.); (R.T.); (X.Z.); (R.W.); (X.W.); (R.M.); (F.C.); (T.Y.)
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Chen H, Zeng Y, Wang D, Li Y, Xing J, Zeng Y, Liu Z, Zhou X, Fan H. Neuroinflammation of Microglial Regulation in Alzheimer's Disease: Therapeutic Approaches. Molecules 2024; 29:1478. [PMID: 38611758 PMCID: PMC11013124 DOI: 10.3390/molecules29071478] [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: 02/04/2024] [Revised: 03/13/2024] [Accepted: 03/23/2024] [Indexed: 04/14/2024] Open
Abstract
Alzheimer's disease (AD) is a complex degenerative disease of the central nervous system that is clinically characterized by a progressive decline in memory and cognitive function. The pathogenesis of AD is intricate and not yet fully understood. Neuroinflammation, particularly microglial activation-mediated neuroinflammation, is believed to play a crucial role in increasing the risk, triggering the onset, and hastening the progression of AD. Modulating microglial activation and regulating microglial energy metabolic disorder are seen as promising strategies to intervene in AD. The application of anti-inflammatory drugs and the targeting of microglia for the prevention and treatment of AD has emerged as a new area of research interest. This article provides a comprehensive review of the role of neuroinflammation of microglial regulation in the development of AD, exploring the connection between microglial energy metabolic disorder, neuroinflammation, and AD development. Additionally, the advancements in anti-inflammatory and microglia-regulating therapies for AD are discussed.
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Affiliation(s)
- Haiyun Chen
- College of Pharmacy, Clinical Pharmacy (School of Integrative Pharmacy), Guangdong Pharmaceutical University, Guangzhou 510006, China; (H.C.)
| | - Yuhan Zeng
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangzhou 510006, China; (Y.Z.)
- Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou 510006, China
- Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Guangzhou 510006, China
- Key Unit of Modulating Liver to Treat Hyperlipemia SATCM, State Administration of Traditional Chinese Medicine, Guangzhou 510006, China
| | - Dan Wang
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangzhou 510006, China; (Y.Z.)
- Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou 510006, China
- Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Guangzhou 510006, China
- Key Unit of Modulating Liver to Treat Hyperlipemia SATCM, State Administration of Traditional Chinese Medicine, Guangzhou 510006, China
| | - Yichen Li
- Guangdong Provincial Key Laboratory of Research and Development of Natural Drugs, School of Pharmacy, Guangdong Medical University, Zhanjiang 524023, China;
| | - Jieyu Xing
- College of Pharmacy, Clinical Pharmacy (School of Integrative Pharmacy), Guangdong Pharmaceutical University, Guangzhou 510006, China; (H.C.)
| | - Yuejia Zeng
- College of Pharmacy, Clinical Pharmacy (School of Integrative Pharmacy), Guangdong Pharmaceutical University, Guangzhou 510006, China; (H.C.)
| | - Zheng Liu
- School of Medicine, Foshan University, Foshan 528000, China;
| | - Xinhua Zhou
- Guangzhou Eighth People’s Hospital, Guangzhou Medical University, Guangzhou 510000, China
| | - Hui Fan
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangzhou 510006, China; (Y.Z.)
- Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou 510006, China
- Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Guangzhou 510006, China
- Key Unit of Modulating Liver to Treat Hyperlipemia SATCM, State Administration of Traditional Chinese Medicine, Guangzhou 510006, China
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Wang X, Xie Y, Chen G, Lu Y, Wang D, Zhu L. Intermittent hypoxia therapy ameliorates beta-amyloid pathology via TFEB-mediated autophagy in murine Alzheimer's disease. J Neuroinflammation 2023; 20:240. [PMID: 37864249 PMCID: PMC10588168 DOI: 10.1186/s12974-023-02931-6] [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: 07/04/2023] [Accepted: 10/12/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder. Impaired autophagy in plaque-associated microglia (PAM) has been reported to accelerate amyloid plaque deposition and cognitive impairment in AD pathogenesis. Recent evidence suggests that the transcription factor EB (TFEB)-mediated activation of the autophagy-lysosomal pathway is a promising treatment approach for AD. Moreover, the complementary therapy of intermittent hypoxia therapy (IHT) has been shown to upregulate autophagy and impart beneficial effects in patients with AD. However, the effect of IHT on PAM remains unknown. METHODS 8-Month-old APP/PS1 mice were treated with IHT for 28 days. Spatial learning memory capacity and anxiety in mice were investigated. AD pathology was determined by the quantity of nerve fibers and synapses density, numbers of microglia and neurons, Aβ plaque deposition, pro-inflammatory factors, and the content of Aβ in the brain. TFEB-mediated autophagy was determined by western blot and qRT-PCR. Primary microglia were treated with oligomeric Aβ 1-42 (oAβ) combined with IHT for mechanism exploration. Differential genes were screened by RNA-seq. Autophagic degradation process of intracellular oAβ was traced by immunofluorescence. RESULTS In this study, we found that IHT ameliorated cognitive function by attenuating neuronal loss and axonal injury in an AD animal model (APP/PS1 mice) with beta-amyloid (Aβ) pathology. In addition, IHT-mediated neuronal protection was associated with reduced Aβ accumulation and plaque formation. Using an in vitro PAM model, we further confirmed that IHT upregulated autophagy-related proteins, thereby promoting the Aβ autophagic degradation by PAM. Mechanistically, IHT facilitated the nuclear localization of TFEB in PAM, with TFEB activity showing a positive correlation with Aβ degradation by PAM in vivo and in vitro. In addition, IHT-induced TFEB activation was associated with the inhibition of the AKT-MAPK-mTOR pathway. CONCLUSIONS These results suggest that IHT alleviates neuronal damage and neuroinflammation via the upregulation of TFEB-dependent Aβ clearance by PAM, leading to improved learning and memory in AD mice. Therefore, IHT may be a promising non-pharmacologic therapy in complementary medicine against AD.
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Affiliation(s)
- Xueting Wang
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No. 9, Seyuan Road, Chongchuan District, Nantong, 226009, Jiangsu, China.
| | - Yuqi Xie
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No. 9, Seyuan Road, Chongchuan District, Nantong, 226009, Jiangsu, China
| | - Guijuan Chen
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No. 9, Seyuan Road, Chongchuan District, Nantong, 226009, Jiangsu, China
| | - Yapeng Lu
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No. 9, Seyuan Road, Chongchuan District, Nantong, 226009, Jiangsu, China
| | - Dan Wang
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No. 9, Seyuan Road, Chongchuan District, Nantong, 226009, Jiangsu, China
| | - Li Zhu
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No. 9, Seyuan Road, Chongchuan District, Nantong, 226009, Jiangsu, China.
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Litke R, Vicari J, Huang BT, Shapiro L, Roh KH, Silver A, Talreja P, Palacios N, Yoon Y, Kellner C, Kaniskan H, Vangeti S, Jin J, Ramos-Lopez I, Mobbs C. Novel small molecules inhibit proteotoxicity and inflammation: Mechanistic and therapeutic implications for Alzheimer's Disease, healthspan and lifespan- Aging as a consequence of glycolysis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544352. [PMID: 37398396 PMCID: PMC10312632 DOI: 10.1101/2023.06.12.544352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Inflammation drives many age-related, especially neurological, diseases, and likely mediates age-related proteotoxicity. For example, dementia due to Alzheimer's Disease (AD), cerebral vascular disease, many other neurodegenerative conditions is increasingly among the most devastating burdens on the American (and world) health system and threatens to bankrupt the American health system as the population ages unless effective treatments are developed. Dementia due to either AD or cerebral vascular disease, and plausibly many other neurodegenerative and even psychiatric conditions, is driven by increased age-related inflammation, which in turn appears to mediate Abeta and related proteotoxic processes. The functional significance of inflammation during aging is also supported by the fact that Humira, which is simply an antibody to the pro-inflammatory cytokine TNF-a, is the best-selling drug in the world by revenue. These observations led us to develop parallel high-throughput screens to discover small molecules which inhibit age-related Abeta proteotoxicity in a C. elegans model of AD AND LPS-induced microglial TNF-a. In the initial screen of 2560 compounds (Microsource Spectrum library) to delay Abeta proteotoxicity, the most protective compounds were, in order, phenylbutyrate, methicillin, and quetiapine, which belong to drug classes (HDAC inhibitors, beta lactam antibiotics, and tricyclic antipsychotics, respectably) already robustly implicated as promising to protect in neurodegenerative diseases, especially AD. RNAi and chemical screens indicated that the protective effects of HDAC inhibitors to reduce Abeta proteotoxicity are mediated by inhibition of HDAC2, also implicated in human AD, dependent on the HAT Creb binding protein (Cbp), which is also required for the protective effects of both dietary restriction and the daf-2 mutation (inactivation of IGF-1 signaling) during aging. In addition to methicillin, several other beta lactam antibiotics also delayed Abeta proteotoxicity and reduced microglial TNF-a. In addition to quetiapine, several other tricyclic antipsychotic drugs also delayed age-related Abeta proteotoxicity and increased microglial TNF-a, leading to the synthesis of a novel congener, GM310, which delays Abeta as well as Huntingtin proteotoxicity, inhibits LPS-induced mouse and human microglial and monocyte TNF-a, is highly concentrated in brain after oral delivery with no apparent toxicity, increases lifespan, and produces molecular responses highly similar to those produced by dietary restriction, including induction of Cbp inhibition of inhibitors of Cbp, and genes promoting a shift away from glycolysis and toward metabolism of alternate (e.g., lipid) substrates. GM310, as well as FDA-approved tricyclic congeners, prevented functional impairments and associated increase in TNF-a in a mouse model of stroke. Robust reduction of glycolysis by GM310 was functionally corroborated by flux analysis, and the glycolytic inhibitor 2-DG inhibited microglial TNF-a and other markers of inflammation, delayed Abeta proteotoxicity, and increased lifespan. These results support the value of phenotypic screens to discover drugs to treat age-related, especially neurological and even psychiatric diseases, including AD and stroke, and to clarify novel mechanisms driving neurodegeneration (e.g., increased microglial glycolysis drives neuroinflammation and subsequent neurotoxicity) suggesting novel treatments (selective inhibitors of microglial glycolysis).
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Lee CYD, De La Rocha AJ, Inouye K, Langfelder P, Daggett A, Gu X, Jiang LL, Pamonag Z, Vaca RG, Richman J, Kawaguchi R, Gao F, Xu H, Yang XW. BAC Transgenic Expression of Human TREM2-R47H Remodels Amyloid Plaques but Unable to Reprogram Plaque-associated Microglial Reactivity in 5xFAD Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.03.551881. [PMID: 37577582 PMCID: PMC10418161 DOI: 10.1101/2023.08.03.551881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Background Genetic study of late-onset Alzheimer's disease (AD) reveals that a rare Arginine-to-Histamine mutation at amino acid residue 47 (R47H) in Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) results in increased disease risk. TREM2 plays critical roles in regulating microglial response to amyloid plaques in AD, leading to their clustering and activation surrounding the plaques. We previously showed that increasing human TREM2 gene dosage exerts neuroprotective effects against AD-related deficits in amyloid depositing mouse models of AD. However, the in vivo effects of the R47H mutation on human TREM2-mediated microglial reprogramming and neuroprotection remains poorly understood. Method Here we created a BAC transgenic mouse model expressing human TREM2 with the R47H mutation in its cognate genomic context (BAC-TREM2-R47H). Importantly, the BAC used in this study was engineered to delete critical exons of other TREM-like genes on the BAC to prevent confounding effects of overexpressing multiple TREM-like genes. We crossed BAC-TREM2- R47H mice with 5xFAD [1], an amyloid depositing mouse model of AD, to evaluate amyloid pathologies and microglial phenotypes, transcriptomics and in situ expression of key TREM2 -dosage dependent genes. We also compared the key findings in 5xFAD/BAC-TREM2-R47H to those observed in 5xFAD/BAC-TREM2 mice. Result Both BAC-TREM2 and BAC-TREM2-R47H showed proper expression of three splicing isoforms of TREM2 that are normally found in human. In 5xFAD background, elevated TREM2-R47H gene dosages significantly reduced the plaque burden, especially the filamentous type. The results were consistent with enhanced phagocytosis and altered NLRP3 inflammasome activation in BAC- TREM2-R47H microglia in vitro. However, unlike TREM2 overexpression, elevated TREM2- R47H in 5xFAD failed to ameliorate cognitive and transcriptomic deficits. In situ analysis of key TREM2 -dosage dependent genes and microglial morphology uncovered that TREM2-R47H showed a loss-of-function phenotype in reprogramming of plaque-associated microglial reactivity and gene expression in 5xFAD. Conclusion Our study demonstrated that the AD-risk variant has a previously unknown, mixture of partial and full loss of TREM2 functions in modulating microglial response in AD mouse brains. Together, our new BAC-TREM2-R47H model and prior BAC-TREM2 mice are invaluable resource to facilitate the therapeutic discovery that target human TREM2 and its R47H variant to ameliorate AD and other neurodegenerative disorders.
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Alshamrani M. Recent Trends in Active and Passive Immunotherapies of Alzheimer's Disease. Antibodies (Basel) 2023; 12:41. [PMID: 37366656 DOI: 10.3390/antib12020041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/24/2023] [Accepted: 06/01/2023] [Indexed: 06/28/2023] Open
Abstract
In the elderly, a debilitating condition known as dementia, which is a major health concern, is caused by Alzheimer's disease (AD). Despite promising advances by researchers, there is currently no way to completely cure this devastating disease. It is illustrated by the deposition of amyloid β-peptide (Aβ) plaques that are followed by neural dysfunction and cognitive decline. Responses against AD activate an immune system that contributes to and accelerates AD pathogenesis. Potential efforts in the field of pathogenesis have prompted researchers to explore novel therapies such as active and passive vaccines against Aβ proteins (Aβ immunotherapy), intravenous immunoglobulin, and tau immunotherapy, as well as targets that include microglia and several cytokines for the treatment of AD. Aims are now underway by experts to begin immunotherapies before the clinical manifestation, which is made possible by improving the sensitivity of biomarkers used for the diagnosis of AD to have better outcome measures. This review provides an overview of approved immunotherapeutic strategies for AD and those currently being investigated in clinical trials. We examine their mechanisms of action and discuss the potential perspectives and challenges associated with immunotherapies for AD.
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Affiliation(s)
- Meshal Alshamrani
- Department of Pharmaceutics, College of Pharmacy, Jazan University, Jazan 45142, Saudi Arabia
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Razi S, Yaghmoorian Khojini J, Kargarijam F, Panahi S, Tahershamsi Z, Tajbakhsh A, Gheibihayat SM. Macrophage efferocytosis in health and disease. Cell Biochem Funct 2023; 41:152-165. [PMID: 36794573 DOI: 10.1002/cbf.3780] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023]
Abstract
Creating cellular homeostasis within a defined tissue typically relates to the processes of apoptosis and efferocytosis. A great example here is cell debris that must be removed to prevent unwanted inflammatory responses and then reduce autoimmunity. In view of that, defective efferocytosis is often assumed to be responsible for the improper clearance of apoptotic cells (ACs). This predicament triggers off inflammation and even results in disease development. Any disruption of phagocytic receptors, molecules as bridging groups, or signaling routes can also inhibit macrophage efferocytosis and lead to the impaired clearance of the apoptotic body. In this line, macrophages as professional phagocytic cells take the lead in the efferocytosis process. As well, insufficiency in macrophage efferocytosis facilitates the spread of a wide variety of diseases, including neurodegenerative diseases, kidney problems, types of cancer, asthma, and the like. Establishing the functions of macrophages in this respect can be thus useful in the treatment of many diseases. Against this background, this review aimed to recapitulate the knowledge about the mechanisms related to macrophage polarization under physiological or pathological conditions, and shed light on its interaction with efferocytosis.
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Affiliation(s)
- Shokufeh Razi
- Department of Genetics, Faculty of Basic Sciences, Central Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Javad Yaghmoorian Khojini
- Department of Medical Biotechnology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Fateme Kargarijam
- Department of Biotechnology, Faculty of Sciences and Advanced Technology in Biology, University of Science and Culture, Tehran, Iran
| | - Susan Panahi
- Department of Microbiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Zahra Tahershamsi
- Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Amir Tajbakhsh
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Molecular Medicine, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyed Mohammad Gheibihayat
- Department of Medical Biotechnology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.,Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Munich, Germany
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10
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Hernandez M, Vaughan J, Gordon T, Lippmann M, Gandy S, Chen LC. World Trade Center dust induces nasal and neurological tissue injury while propagating reduced olfaction capabilities and increased anxiety behaviors. Inhal Toxicol 2022; 34:175-188. [PMID: 35533138 PMCID: PMC9728549 DOI: 10.1080/08958378.2022.2072027] [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] [Indexed: 11/05/2022]
Abstract
Objective: Previous in vitro and in vivo World Trade Center particulate matter (WTCPM) exposure studies have provided evidence of exposure-driven oxidative/nitrative stress and inflammation on respiratory tract and aortic tissues. What remains to be fully understood are secondary organ impacts due to WTCPM exposure. This study was designed to test if WTC particle-induced nasal and neurologic tissue injury may result in unforeseen functional and behavioral outcomes.Material and Methods: WTCPM was intranasally administered in mice, evaluating genotypic, histopathologic, and olfaction latency endpoints.Results: WTCPM exposure was found to incite neurologic injury and olfaction latency in intranasally (IN) exposed mice. Single high-dose and repeat low-dose nasal cavity insults from WTCPM dust resulted in significant olfaction delays and enduring olfaction deficits. Anxiety-dependent behaviors also occurred in mice experiencing olfaction loss including significant body weight loss, increased incidence and time spent in hind stretch postures, as well as increased stationary time and decreased exploratory time. Additionally, WTCPM exposure resulted in increased whole brain wet/dry ratios and wet whole brain to body mass ratios that were correlated with exposure and increased exposure dose (p<0.05).Discussion: The potential molecular drivers of WTCPM-driven tissue injury and olfaction latency may be linked to oxidative/nitrative stress and inflammatory cascades in both upper respiratory nasal and brain tissues.Conclusion: Cumulatively, these data provide evidence of WTCPM exposure in relation to tissue damage related to oxidative stress-driven inflammation identified in the nasal cavity, propagated to olfactory bulb tissues and, potentially, over extended periods, to other CNS tissues.
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Affiliation(s)
- Michelle Hernandez
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA
| | - Joshua Vaughan
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA
| | - Terry Gordon
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA
| | - Morton Lippmann
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA
| | - Sam Gandy
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
- James J Peter VA Medical Center, Bronx, NY, USA
| | - Lung-Chi Chen
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA
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11
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Pathophysiology of neurodegenerative diseases: An interplay among axonal transport failure, oxidative stress, and inflammation? Semin Immunol 2022; 59:101628. [PMID: 35779975 PMCID: PMC9807734 DOI: 10.1016/j.smim.2022.101628] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 04/09/2022] [Accepted: 06/13/2022] [Indexed: 01/15/2023]
Abstract
Neurodegenerative diseases (NDs) are heterogeneous neurological disorders characterized by a progressive loss of selected neuronal populations. A significant risk factor for most NDs is aging. Considering the constant increase in life expectancy, NDs represent a global public health burden. Axonal transport (AT) is a central cellular process underlying the generation and maintenance of neuronal architecture and connectivity. Deficits in AT appear to be a common thread for most, if not all, NDs. Neuroinflammation has been notoriously difficult to define in relation to NDs. Inflammation is a complex multifactorial process in the CNS, which varies depending on the disease stage. Several lines of evidence suggest that AT defect, axonopathy and neuroinflammation are tightly interlaced. However, whether these impairments play a causative role in NDs or are merely a downstream effect of neuronal degeneration remains unsettled. We still lack reliable information on the temporal relationship between these pathogenic mechanisms, although several findings suggest that they may occur early during ND pathophysiology. This article will review the latest evidence emerging on whether the interplay between AT perturbations and some aspects of CNS inflammation can participate in ND etiology, analyze their potential as therapeutic targets, and the urge to identify early surrogate biomarkers.
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12
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Uddin MS, Kabir MT, Jalouli M, Rahman MA, Jeandet P, Behl T, Alexiou A, Albadrani GM, Abdel-Daim MM, Perveen A, Ashraf GM. Neuroinflammatory Signaling in the Pathogenesis of Alzheimer's Disease. Curr Neuropharmacol 2021; 20:126-146. [PMID: 34525932 PMCID: PMC9199559 DOI: 10.2174/1570159x19666210826130210] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 04/16/2021] [Accepted: 05/10/2021] [Indexed: 11/22/2022] Open
Abstract
Alzheimer’s disease (AD) is a chronic neurodegenerative disease characterized by the formation of intracellular neurofibrillary tangles (NFTs) and extracellular amyloid plaques. Growing evidence has suggested that AD pathogenesis is not only limited to the neuronal compartment but also strongly interacts with immunological processes in the brain. On the other hand, aggregated and misfolded proteins can bind with pattern recognition receptors located on astroglia and microglia and can, in turn, induce an innate immune response, characterized by the release of inflammatory mediators, ultimately playing a role in both the severity and the progression of the disease. It has been reported by genome-wide analysis that several genes which elevate the risk for sporadic AD encode for factors controlling the inflammatory response and glial clearance of misfolded proteins. Obesity and systemic inflammation are examples of external factors which may interfere with the immunological mechanisms of the brain and can induce disease progression. In this review, we discussed the mechanisms and essential role of inflammatory signaling pathways in AD pathogenesis. Indeed, interfering with immune processes and modulation of risk factors may lead to future therapeutic or preventive AD approaches.
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Affiliation(s)
- Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka. Bangladesh
| | | | - Maroua Jalouli
- College of Science, King Saud University, P.O. Box 2455, Riyadh 11451. Saudi Arabia
| | - Md Ataur Rahman
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology, Seoul. Korea
| | - Philippe Jeandet
- Research Unit "Induced Resistance and Plant Bioprotection", EA 4707, SFR Condorcet FR CNRS 3417, Faculty of Sciences, University of Reims Champagne-Ardenne, PO Box 1039, 51687 Reims Cedex 2. France
| | - Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab. India
| | - Athanasios Alexiou
- Novel Global Community Educational Foundation, 2770 Hebersham. Australia
| | - Ghadeer M Albadrani
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11474. Saudi Arabia
| | - Mohamed M Abdel-Daim
- Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522. Egypt
| | - Asma Perveen
- Glocal School of Life Sciences, Glocal University, Saharanpur. India
| | - Ghulam Md Ashraf
- Pre-Clinical Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah. Saudi Arabia
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13
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Shaw BC, Katsumata Y, Simpson JF, Fardo DW, Estus S. Analysis of Genetic Variants Associated with Levels of Immune Modulating Proteins for Impact on Alzheimer's Disease Risk Reveal a Potential Role for SIGLEC14. Genes (Basel) 2021; 12:genes12071008. [PMID: 34208838 PMCID: PMC8303736 DOI: 10.3390/genes12071008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 01/22/2023] Open
Abstract
Genome-wide association studies (GWAS) have identified immune-related genes as risk factors for Alzheimer’s disease (AD), including TREM2 and CD33, frequently passing a stringent false-discovery rate. These genes either encode or signal through immunomodulatory tyrosine-phosphorylated inhibitory motifs (ITIMs) or activation motifs (ITAMs) and govern processes critical to AD pathology, such as inflammation and amyloid phagocytosis. To investigate whether additional ITIM and ITAM-containing family members may contribute to AD risk and be overlooked due to the stringent multiple testing in GWAS, we combined protein quantitative trait loci (pQTL) data from a recent plasma proteomics study with AD associations in a recent GWAS. We found that pQTLs for genes encoding ITIM/ITAM family members were more frequently associated with AD than those for non-ITIM/ITAM genes. Further testing of one family member, SIGLEC14 which encodes an ITAM, uncovered substantial copy number variations, identified an SNP as a proxy for gene deletion, and found that gene expression correlates significantly with gene deletion. We also found that SIGLEC14 deletion increases the expression of SIGLEC5, an ITIM. We conclude that many genes in this ITIM/ITAM family likely impact AD risk, and that complex genetics including copy number variation, opposing function of encoded proteins, and coupled gene expression may mask these AD risk associations at the genome-wide level.
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Affiliation(s)
- Benjamin C. Shaw
- Department of Physiology, University of Kentucky, Lexington, KY 40506, USA; (B.C.S.); (J.F.S.)
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, USA;
| | - Yuriko Katsumata
- Department of Biostatistics, University of Kentucky, Lexington, KY 40506, USA;
| | - James F. Simpson
- Department of Physiology, University of Kentucky, Lexington, KY 40506, USA; (B.C.S.); (J.F.S.)
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, USA;
| | - David W. Fardo
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, USA;
- Department of Biostatistics, University of Kentucky, Lexington, KY 40506, USA;
| | - Steven Estus
- Department of Physiology, University of Kentucky, Lexington, KY 40506, USA; (B.C.S.); (J.F.S.)
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, USA;
- Correspondence: ; Tel.: +1-859-218-2388
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14
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Edler MK, Mhatre-Winters I, Richardson JR. Microglia in Aging and Alzheimer's Disease: A Comparative Species Review. Cells 2021; 10:1138. [PMID: 34066847 PMCID: PMC8150617 DOI: 10.3390/cells10051138] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 12/11/2022] Open
Abstract
Microglia are the primary immune cells of the central nervous system that help nourish and support neurons, clear debris, and respond to foreign stimuli. Greatly impacted by their environment, microglia go through rapid changes in cell shape, gene expression, and functional behavior during states of infection, trauma, and neurodegeneration. Aging also has a profound effect on microglia, leading to chronic inflammation and an increase in the brain's susceptibility to neurodegenerative processes that occur in Alzheimer's disease. Despite the scientific community's growing knowledge in the field of neuroinflammation, the overall success rate of drug treatment for age-related and neurodegenerative diseases remains incredibly low. Potential reasons for the lack of translation from animal models to the clinic include the use of a single species model, an assumption of similarity in humans, and ignoring contradictory data or information from other species. To aid in the selection of validated and predictive animal models and to bridge the translational gap, this review evaluates similarities and differences among species in microglial activation and density, morphology and phenotype, cytokine expression, phagocytosis, and production of oxidative species in aging and Alzheimer's disease.
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Affiliation(s)
- Melissa K. Edler
- Department of Anthropology, School of Biomedical Sciences, Brain Health Research Institute, Kent State University, Kent, OH 44240, USA;
| | - Isha Mhatre-Winters
- School of Biomedical Sciences, College of Arts and Sciences, Kent State University, Kent, OH 44240, USA;
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL 33199, USA
| | - Jason R. Richardson
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL 33199, USA
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15
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Moelgg K, Jummun F, Humpel C. Spreading of Beta-Amyloid in Organotypic Mouse Brain Slices and Microglial Elimination and Effects on Cholinergic Neurons. Biomolecules 2021; 11:434. [PMID: 33804246 PMCID: PMC7999593 DOI: 10.3390/biom11030434] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/03/2021] [Accepted: 03/11/2021] [Indexed: 01/29/2023] Open
Abstract
The extracellular deposition of β-amyloid (Aβ) is one of the major characteristics in Alzheimer´s disease (AD). The "spreading hypothesis" suggests that a pathological protein (similar to prions) spreads over the entire brain. The aim of the present study was to use organotypic brain slices of postnatal day 8-10 mice. Using collagen hydrogels, we applied different Aβ peptides onto brain slices and analyzed spreading as well as glial reactions after eight weeks of incubation. Our data showed that from all tested Aβ peptides, human Aβ42 had the most potent activity to spread over into adjacent "target" areas. This effect was potentiated when brain slices from transgenic AD mice (APP_SweDI) were cultured. When different brain areas were connected to the "target slice" the spreading activity was more intense, originating from ventral striatum and brain stem. Reactive glial-fibrillary acidic protein (GFAP) astrogliosis increased over time, but Aβ depositions co-localized only with Iba1+ microglia but not with astrocytes. Application of human Aβ42 did not cause a degeneration of cholinergic neurons. We concluded that human Aβ42 spreads over into other "target areas", causing activation of glial cells. Most of the spread Aβ42 was taken up by microglia, and thus toxic free Aβ could not damage cholinergic neurons.
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Affiliation(s)
| | | | - Christian Humpel
- Laboratory of Psychiatry and Experimental Alzheimer’s Research, Department Psychiatry I, Medical University of Innsbruck, Anichstr 35, A-6020 Innsbruck, Austria; (K.M.); (F.J.)
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16
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Bera S, Camblor‐Perujo S, Calleja Barca E, Negrete‐Hurtado A, Racho J, De Bruyckere E, Wittich C, Ellrich N, Martins S, Adjaye J, Kononenko NL. AP-2 reduces amyloidogenesis by promoting BACE1 trafficking and degradation in neurons. EMBO Rep 2020; 21:e47954. [PMID: 32323475 PMCID: PMC7271323 DOI: 10.15252/embr.201947954] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 03/11/2020] [Accepted: 03/13/2020] [Indexed: 12/13/2022] Open
Abstract
Cleavage of amyloid precursor protein (APP) by BACE-1 (β-site APP cleaving enzyme 1) is the rate-limiting step in amyloid-β (Aβ) production and a neuropathological hallmark of Alzheimer's disease (AD). Despite decades of research, mechanisms of amyloidogenic APP processing remain highly controversial. Here, we show that in neurons, APP processing and Aβ production are controlled by the protein complex-2 (AP-2), an endocytic adaptor known to be required for APP endocytosis. Now, we find that AP-2 prevents amyloidogenesis by additionally functioning downstream of BACE1 endocytosis, regulating BACE1 endosomal trafficking and its delivery to lysosomes. AP-2 is decreased in iPSC-derived neurons from patients with late-onset AD, while conditional AP-2 knockout (KO) mice exhibit increased Aβ production, resulting from accumulation of BACE1 within late endosomes and autophagosomes. Deletion of BACE1 decreases amyloidogenesis and mitigates synapse loss in neurons lacking AP-2. Taken together, these data suggest a mechanism for BACE1 intracellular trafficking and degradation via an endocytosis-independent function of AP-2 and reveal a novel role for endocytic proteins in AD.
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Affiliation(s)
- Sujoy Bera
- CECAD Research CenterUniversity of CologneCologneGermany
- Present address:
Centre for Neuroscience and Regenerative MedicineFaculty of ScienceUniversity of Technology SydneySydneyNSWAustralia
| | | | | | | | - Julia Racho
- CECAD Research CenterUniversity of CologneCologneGermany
| | | | | | - Nina Ellrich
- CECAD Research CenterUniversity of CologneCologneGermany
| | - Soraia Martins
- Institute for Stem Cell Research and Regenerative MedicineMedical FacultyHeinrich Heine UniversityDüsseldorfGermany
| | - James Adjaye
- Institute for Stem Cell Research and Regenerative MedicineMedical FacultyHeinrich Heine UniversityDüsseldorfGermany
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17
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Dierckx T, Bogie JFJ, Hendriks JJA. The Impact of Phytosterols on the Healthy and Diseased Brain. Curr Med Chem 2020; 26:6750-6765. [PMID: 29984647 DOI: 10.2174/0929867325666180706113844] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/28/2018] [Accepted: 03/07/2018] [Indexed: 02/07/2023]
Abstract
The central nervous system (CNS) is the most cholesterol-rich organ in mammals. Cholesterol homeostasis is essential for proper brain functioning and dysregulation of cholesterol metabolism can lead to neurological problems. Multiple sclerosis (MS) and Alzheimer's disease (AD) are examples of neurological diseases that are characterized by a disturbed cholesterol metabolism. Phytosterols (PS) are plant-derived components that structurally and functionally resemble cholesterol. PS are known for their cholesterol-lowering properties. Due to their ability to reach the brain, researchers have started to investigate the physiological role of PS in the CNS. In this review, the metabolism and function of PS in the diseased and healthy CNS are discussed.
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Affiliation(s)
- Tess Dierckx
- Biomedical Research Institute, Hasselt University, Diepenbeek, Hassett, Belgium
| | - Jeroen F J Bogie
- Biomedical Research Institute, Hasselt University, Diepenbeek, Hassett, Belgium
| | - Jerome J A Hendriks
- Biomedical Research Institute, Hasselt University, Diepenbeek, Hassett, Belgium
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18
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Microglia, Lifestyle Stress, and Neurodegeneration. Immunity 2020; 52:222-240. [PMID: 31924476 DOI: 10.1016/j.immuni.2019.12.003] [Citation(s) in RCA: 177] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/26/2019] [Accepted: 12/09/2019] [Indexed: 02/06/2023]
Abstract
Recent years have witnessed a revolution in our understanding of microglia biology, including their major role in the etiology and pathogenesis of neurodegenerative diseases. Technological advances have enabled the identification of microglial signatures in health and disease, including the development of new models to investigate and manipulate human microglia in vivo in the context of disease. In parallel, genetic association studies have identified several gene risk factors associated with Alzheimer's disease that are specifically or highly expressed by microglia in the central nervous system (CNS). Here, we discuss evidence for the effect of stress, diet, sleep patterns, physical activity, and microbiota composition on microglia biology and consider how lifestyle might influence an individual's predisposition to neurodegenerative diseases. We discuss how different lifestyles and environmental factors might regulate microglia, potentially leading to increased susceptibility to neurodegenerative disease, and we highlight the need to investigate the contribution of modern environmental factors on microglia modulation in neurodegeneration.
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19
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Jürgenson M, Zharkovskaja T, Noortoots A, Morozova M, Beniashvili A, Zapolski M, Zharkovsky A. Effects of the drug combination memantine and melatonin on impaired memory and brain neuronal deficits in an amyloid-predominant mouse model of Alzheimer's disease. J Pharm Pharmacol 2019; 71:1695-1705. [DOI: 10.1111/jphp.13165] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/16/2019] [Accepted: 08/22/2019] [Indexed: 12/30/2022]
Abstract
Abstract
Objectives
Alzheimer's disease (AD) is a neurodegenerative disorder with no cure. Limited treatment options available today do not offer solutions to slow or stop any of the suspected causes. The current medications used for the symptomatic treatment of AD include memantine and acetylcholine esterase inhibitors. Some studies suggest that melatonin could also be used in AD patients due to its sleep-improving properties.
Methods
In this study, we evaluated whether a combination of memantine with melatonin, administered for 32 days in drinking water, was more effective than either drug alone with respect to Aβ aggregates, neuroinflammation and cognition in the double transgenic APP/PS1 (5xFAD) mouse model of AD.
Key findings
In this study, chronic administration of memantine with melatonin improved episodic memory in the object recognition test and reduced the number of amyloid aggregates and reactive microgliosis in the brains of 5xFAD mice. Although administration of memantine or melatonin alone also reduced the number of amyloid aggregates and inflammation in brain, this study shows a clear benefit of the drug combination, which had a significantly stronger effect in this amyloid-dominant mouse model of AD.
Conclusion
Our data suggest considerable potential for the use of memantine with melatonin in patients with AD.
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Affiliation(s)
- Monika Jürgenson
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Tamara Zharkovskaja
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Aveli Noortoots
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | | | | | - Max Zapolski
- Valentech Ltd, Skolkovo Innovation Centre, Moscow, Russia
| | - Alexander Zharkovsky
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
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20
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Elevated TREM2 Gene Dosage Reprograms Microglia Responsivity and Ameliorates Pathological Phenotypes in Alzheimer's Disease Models. Neuron 2019. [PMID: 29518357 DOI: 10.1016/j.neuron.2018.02.002] [Citation(s) in RCA: 230] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Variants of TREM2 are associated with Alzheimer's disease (AD). To study whether increasing TREM2 gene dosage could modify the disease pathogenesis, we developed BAC transgenic mice expressing human TREM2 (BAC-TREM2) in microglia. We found that elevated TREM2 expression reduced amyloid burden in the 5xFAD mouse model. Transcriptomic profiling demonstrated that increasing TREM2 levels conferred a rescuing effect, which includes dampening the expression of multiple disease-associated microglial genes and augmenting downregulated neuronal genes. Interestingly, 5xFAD/BAC-TREM2 mice showed further upregulation of several reactive microglial genes linked to phagocytosis and negative regulation of immune cell activation. Moreover, these mice showed enhanced process ramification and phagocytic marker expression in plaque-associated microglia and reduced neuritic dystrophy. Finally, elevated TREM2 gene dosage led to improved memory performance in AD models. In summary, our study shows that a genomic transgene-driven increase in TREM2 expression reprograms microglia responsivity and ameliorates neuropathological and behavioral deficits in AD mouse models.
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Yao K, Zu HB. Microglial polarization: novel therapeutic mechanism against Alzheimer's disease. Inflammopharmacology 2019; 28:95-110. [PMID: 31264132 DOI: 10.1007/s10787-019-00613-5] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/16/2019] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative disease that results in progressive dementia, and exhibits high disability and fatality rates. Recent evidence has demonstrated that neuroinflammation is critical in the pathophysiological processes of AD, which is characterized by the activation of microglia and astrocytes. Under different stimuli, microglia are usually activated into two polarized states, termed the classical 'M1' phenotype and the alternative 'M2' phenotype. M1 microglia are considered to promote inflammatory injury in AD; in contrast, M2 microglia exert neuroprotective effects. Imbalanced microglial polarization, in the form of excessive activation of M1 microglia and dysfunction of M2 microglia, markedly promotes the development of AD. Furthermore, an increasing number of studies have shown that the transition of microglia from the M1 to M2 phenotype could potently alleviate pathological damage in AD. Hence, this article reviews the current knowledge regarding the role of microglial M1/M2 polarization in the pathophysiology of AD. In addition, we summarize several approaches that protect against AD by altering the polarization states of microglia. This review aims to contribute to a better understanding of the pathogenesis of AD and, moreover, to explore the potential of novel drugs for the treatment of AD in the future.
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Affiliation(s)
- Kai Yao
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Heng-Bing Zu
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China.
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Kaieda A, Takahashi M, Fukuda H, Okamoto R, Morimoto S, Gotoh M, Miyazaki T, Hori Y, Unno S, Kawamoto T, Tanaka T, Itono S, Takagi T, Sugimoto H, Okada K, Snell G, Bertsch R, Nguyen J, Sang BC, Miwatashi S. Structure-Based Design, Synthesis, and Biological Evaluation of Imidazo[4,5-b]pyridin-2-one-Based p38 MAP Kinase Inhibitors: Part 1. ChemMedChem 2019; 14:1022-1030. [PMID: 30945818 DOI: 10.1002/cmdc.201900129] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/03/2019] [Indexed: 12/22/2022]
Abstract
We identified a lead series of p38 mitogen-activated protein kinase inhibitors using a structure-based design strategy from high-throughput screening of hit compound 1. X-ray crystallography of 1 with the kinase showed an infrequent flip of the peptide bond between Met109 and Gly110, which was considered to lead to high kinase selectivity. Our structure-based design strategy was to conduct scaffold transformation of 1 with maintenance of hydrogen bond interactions with the flipped hinge backbone of the enzyme. In accordance with this strategy, we focused on scaffold transformation to identify imidazo[4,5-b]pyridin-2-one derivatives as potent inhibitors of the p38 MAP kinase. Of the compounds evaluated, 21 was found to be a potent inhibitor of the p38 MAP kinase, lipopolysaccharide-induced tumor necrosis factor-α (TNF-α) production in human monocytic leukemia cells, and TNF-α-induced production of interleukin-8 in human whole blood cells. Herein we describe the discovery of potent and orally bioavailable imidazo[4,5-b]pyridin-2-one-based p38 MAP kinase inhibitors that suppressed cytokine production in a human whole blood cell-based assay.
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Affiliation(s)
- Akira Kaieda
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Masashi Takahashi
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Hiromi Fukuda
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Rei Okamoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Shinji Morimoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Masayuki Gotoh
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Takahiro Miyazaki
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Yuri Hori
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Satoko Unno
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Tomohiro Kawamoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Toshimasa Tanaka
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Sachiko Itono
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Terufumi Takagi
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Hiroshi Sugimoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Kengo Okada
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Gyorgy Snell
- Takeda California, 10410 Science Center Drive, San Diego, CA, 92121, USA
| | - Ryan Bertsch
- Takeda California, 10410 Science Center Drive, San Diego, CA, 92121, USA
| | - Jasmine Nguyen
- Takeda California, 10410 Science Center Drive, San Diego, CA, 92121, USA
| | - Bi-Ching Sang
- Takeda California, 10410 Science Center Drive, San Diego, CA, 92121, USA
| | - Seiji Miwatashi
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
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Wang Q, Wang Y, Liu J, Sutphen CL, Cruchaga C, Blazey T, Gordon BA, Su Y, Chen C, Shimony JS, Ances BM, Cairns NJ, Fagan AM, Morris JC, Benzinger TLS. Quantification of white matter cellularity and damage in preclinical and early symptomatic Alzheimer's disease. Neuroimage Clin 2019; 22:101767. [PMID: 30901713 PMCID: PMC6428957 DOI: 10.1016/j.nicl.2019.101767] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 02/12/2019] [Accepted: 03/10/2019] [Indexed: 02/08/2023]
Abstract
Interest in understanding the roles of white matter (WM) inflammation and damage in the pathophysiology of Alzheimer disease (AD) has been growing significantly in recent years. However, in vivo magnetic resonance imaging (MRI) techniques for imaging inflammation are still lacking. An advanced diffusion-based MRI method, neuro-inflammation imaging (NII), has been developed to clinically image and quantify WM inflammation and damage in AD. Here, we employed NII measures in conjunction with cerebrospinal fluid (CSF) biomarker classification (for β-amyloid (Aβ) and neurodegeneration) to evaluate 200 participants in an ongoing study of memory and aging. Elevated NII-derived cellular diffusivity was observed in both preclinical and early symptomatic phases of AD, while disruption of WM integrity, as detected by decreased fractional anisotropy (FA) and increased radial diffusivity (RD), was only observed in the symptomatic phase of AD. This may suggest that WM inflammation occurs earlier than WM damage following abnormal Aβ accumulation in AD. The negative correlation between NII-derived cellular diffusivity and CSF Aβ42 level (a marker of amyloidosis) may indicate that WM inflammation is associated with increasing Aβ burden. NII-derived FA also negatively correlated with CSF t-tau level (a marker of neurodegeneration), suggesting that disruption of WM integrity is associated with increasing neurodegeneration. Our findings demonstrated the capability of NII to simultaneously image and quantify WM cellularity changes and damage in preclinical and early symptomatic AD. NII may serve as a clinically feasible imaging tool to study the individual and composite roles of WM inflammation and damage in AD.
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Affiliation(s)
- Qing Wang
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA
| | - Yong Wang
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA; Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Engineering & Applied Science, St. Louis, MO 63015, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Jingxia Liu
- Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Courtney L Sutphen
- Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Carlos Cruchaga
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Tyler Blazey
- Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Brian A Gordon
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA
| | - Yi Su
- Banner Alzheimer's Institute, Phoenix, AZ 85006, USA
| | - Charlie Chen
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joshua S Shimony
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Beau M Ances
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Nigel J Cairns
- Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA; Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Anne M Fagan
- Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - John C Morris
- Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Tammie L S Benzinger
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park, Suite 101, St. Louis, MO 63108, USA; Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO 63110, USA
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Misra A, Chakrabarti SS, Gambhir IS. New genetic players in late-onset Alzheimer's disease: Findings of genome-wide association studies. Indian J Med Res 2019; 148:135-144. [PMID: 30381536 PMCID: PMC6206761 DOI: 10.4103/ijmr.ijmr_473_17] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Late-onset Alzheimer's disease (LOAD) or sporadic AD is the most common form of AD. The precise pathogenetic changes that trigger the development of AD remain largely unknown. Large-scale genome-wide association studies (GWASs) have identified single-nucleotide polymorphisms in multiple genes which are associated with AD; most notably, these are ABCA7, bridging integrator 1(B1N1), triggering receptor expressed on myeloid cells 2 (TREM2), CD33, clusterin (CLU), complement receptor 1 (CRI), ephrin type-A receptor 1 (EPHA1), membrane-spanning 4-domains, subfamily A (MS4A) and phosphatidylinositol binding clathrin assembly protein (PICALM) genes. The proteins coded by the candidate genes participate in a variety of cellular processes such as oxidative balance, protein metabolism, cholesterol metabolism and synaptic function. This review summarizes the major gene loci affecting LOAD identified by large GWASs. Tentative mechanisms have also been elaborated in various studies by which the proteins coded by these genes may exert a role in AD pathogenesis have also been elaborated. The review suggests that these may together affect LOAD pathogenesis in a complementary fashion.
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Affiliation(s)
- Anamika Misra
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | | | - Indrajeet Singh Gambhir
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
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25
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Fan Y, Ma Y, Huang W, Cheng X, Gao N, Li G, Tian S. Up-regulation of TREM2 accelerates the reduction of amyloid deposits and promotes neuronal regeneration in the hippocampus of amyloid beta1-42 injected mice. J Chem Neuroanat 2019; 97:71-79. [PMID: 30790627 DOI: 10.1016/j.jchemneu.2019.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 02/17/2019] [Accepted: 02/17/2019] [Indexed: 01/25/2023]
Abstract
Alzheimer's disease (AD) is characterized by a robust inflammatory response elicited by the accumulation and subsequently deposition of amyloid beta (Aβ) within the brain. The immune cells of brain migrate to and invest their processes within Aβ plaques and clear plaques from the brain. Previous studies have shown that treatment of myeloid cell with nuclear factor inhibitor increases expression of phagocytesis-related genes, such as triggering receptor expressed on myeloid cells 2 (TREM2). In myeloid cells, TREM2 has been involved in the regulation of phagocytosis, cell proliferation as well as inflammatory response in vitro. The purpose of this study was to further investigate microglial proliferation, phagocytosis and the expression of brain derived neurotrophic factor (BDNF) induced by up-regulation of TREM2 in Aβ1-42 injected mice. We first singly injected Aβ1-42 into the hippocampus of mice to build the model of AD-like symptoms. Subsequently, ammonium pyrrolidinedithiocarbamate (PDTC) was injected into the lateral ventricle of mice. Various immunohistochemical techniques and Western blot analyses were applied to examine expressions of TREM2, microglia, Aβ, Neuronal migration protein doublecortin (DCX) and BDNF in the hippocampus of mice. In the present study, we found the plaques-associated microglia lowly expressed TREM2 and BDNF in Aβ1-42 intra-hippocampal injected mice. Treatment of the models with a nuclear factor inhibitor, PDTC, further induced the expression of TREM2 and enhanced microglial phagocytosis, coincident with the rapid reduction in plaque burden. The expression of BDNF was up-regulated and the expression of DCX was partly restored. This means that up-regulation of TREM2 might induce the microglia to express the BDNF. These findings further indicate that the level of TREM2 may affect the microglia response to pathological process induced by Aβ.
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Affiliation(s)
- Yubao Fan
- Department of Anatomy, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Yuxin Ma
- Department of Anatomy, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Weiling Huang
- Department of Anatomy, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Xiaohui Cheng
- Department of Anatomy, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Ningxin Gao
- Department of Anatomy, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Guoying Li
- Department of Anatomy, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Sumin Tian
- Department of Physiology, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
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26
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Edler MK, Sherwood CC, Meindl RS, Munger E, Hopkins WD, Ely JJ, Erwin JM, Perl DP, Mufson EJ, Hof PR, Raghanti MA. Microglia changes associated to Alzheimer's disease pathology in aged chimpanzees. J Comp Neurol 2018; 526:2921-2936. [PMID: 30069930 PMCID: PMC6283685 DOI: 10.1002/cne.24484] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 05/11/2018] [Accepted: 05/16/2018] [Indexed: 01/01/2023]
Abstract
In Alzheimer's disease (AD), the brain's primary immune cells, microglia, become activated and are found in close apposition to amyloid beta (Aβ) protein plaques and neurofibrillary tangles (NFT). The present study evaluated microglia density and morphology in a large group of aged chimpanzees (n = 20, ages 37-62 years) with varying degrees of AD-like pathology. Using immunohistochemical and stereological techniques, we quantified the density of activated microglia and morphological variants (ramified, intermediate, and amoeboid) in postmortem chimpanzee brain samples from prefrontal cortex, middle temporal gyrus, and hippocampus, areas that show a high degree of AD pathology in humans. Microglia measurements were compared to pathological markers of AD in these cases. Activated microglia were consistently present across brain areas. In the hippocampus, CA3 displayed a higher density than CA1. Aβ42 plaque volume was positively correlated with higher microglial activation and with an intermediate morphology in the hippocampus. Aβ42-positive vessel volume was associated with increased hippocampal microglial activation. Activated microglia density and morphology were not associated with age, sex, pretangle density, NFT density, or tau neuritic cluster density. Aged chimpanzees displayed comparable patterns of activated microglia phenotypes as well as an association of increased microglial activation and morphological changes with Aβ deposition similar to AD patients. In contrast to human AD brains, activated microglia density was not significantly correlated with tau lesions. This evidence suggests that the chimpanzee brain may be relatively preserved during normal aging processes but not entirely protected from neurodegeneration as previously assumed.
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Affiliation(s)
- Melissa K. Edler
- School of Biomedical Sciences, Kent State University, Kent, OH 44242
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH 44272
| | - Chet C. Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052
| | | | - Emily Munger
- School of Biomedical Sciences, Kent State University, Kent, OH 44242
| | - William D. Hopkins
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322
- Neuroscience Institute, Georgia State University, Atlanta, GA 30302
| | | | - Joseph M. Erwin
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052
| | - Daniel P. Perl
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - Elliott J. Mufson
- Departments of Neurobiology and Neurology, Barrow Neurological Institute, Phoenix, AZ 85013
| | - Patrick R. Hof
- Fishberg Department of Neuroscience, Ronald M. Loeb Center for Alzheimer’s Disease, and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- New York Consortium for Evolutionary Primatology, New York, NY 10468
| | - Mary Ann Raghanti
- School of Biomedical Sciences, Kent State University, Kent, OH 44242
- Department of Anthropology, Kent State University, Kent, OH 44242
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27
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Zhang X, Fu Z, Meng L, He M, Zhang Z. The Early Events That Initiate β-Amyloid Aggregation in Alzheimer's Disease. Front Aging Neurosci 2018; 10:359. [PMID: 30542277 PMCID: PMC6277872 DOI: 10.3389/fnagi.2018.00359] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 10/22/2018] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by the development of amyloid plaques and neurofibrillary tangles (NFTs) consisting of aggregated β-amyloid (Aβ) and tau, respectively. The amyloid hypothesis has been the predominant framework for research in AD for over two decades. According to this hypothesis, the accumulation of Aβ in the brain is the primary factor initiating the pathogenesis of AD. However, it remains elusive what factors initiate Aβ aggregation. Studies demonstrate that AD has multiple causes, including genetic and environmental factors. Furthermore, genetic factors, many age-related events and pathological conditions such as diabetes, traumatic brain injury (TBI) and aberrant microbiota also affect the aggregation of Aβ. Here we provide an overview of the age-related early events and other pathological processes that precede Aβ aggregation.
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Affiliation(s)
- Xingyu Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhihui Fu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Mingyang He
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
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28
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Bisht K, Sharma K, Tremblay MÈ. Chronic stress as a risk factor for Alzheimer's disease: Roles of microglia-mediated synaptic remodeling, inflammation, and oxidative stress. Neurobiol Stress 2018; 9:9-21. [PMID: 29992181 PMCID: PMC6035903 DOI: 10.1016/j.ynstr.2018.05.003] [Citation(s) in RCA: 223] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/23/2018] [Accepted: 05/14/2018] [Indexed: 02/07/2023] Open
Abstract
Microglia are the predominant immune cells of the central nervous system (CNS) that exert key physiological roles required for maintaining CNS homeostasis, notably in response to chronic stress, as well as mediating synaptic plasticity, learning and memory. The repeated exposure to stress confers a higher risk of developing neurodegenerative diseases including sporadic Alzheimer's disease (AD). While microglia have been causally linked to amyloid beta (Aβ) accumulation, tau pathology, neurodegeneration, and synaptic loss in AD, they were also attributed beneficial roles, notably in the phagocytic elimination of Aβ. In this review, we discuss the interactions between chronic stress and AD pathology, overview the roles played by microglia in AD, especially focusing on chronic stress as an environmental risk factor modulating their function, and present recently-described microglial phenotypes associated with neuroprotection in AD. These microglial phenotypes observed under both chronic stress and AD pathology may provide novel opportunities for the development of better-targeted therapeutic interventions.
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Key Words
- ABCA7, ATP-binding cassette transporter A7
- AD, Alzheimer's disease
- APOE, Apolipoprotein E
- APP, amyloid precursor protein
- Alzheimer's disease
- Aβ, Amyloid beta
- BDNF, brain derived neurotrophic factor
- CD11b, cluster of differentiation molecule 11B
- CD33, cluster of differentiation 33
- CNS, central nervous system
- CR, complement receptor
- CRF, corticotropin releasing factor
- DAM, disease associated microglia
- DAP12, DNAX-activation protein 12
- Dark microglia
- FAD, Familial Alzheimer's disease
- FCRLS, Fc receptor-like S scavenger receptor
- GR, glucocorticoid receptor
- HPA axis, hypothalamic pituitary adrenocortical axis
- IBA1, ionized calcium-binding adapter molecule 1
- IL, interleukin
- LTP, long-term potentiation
- MGnD, microglia with a neurodegenerative phenotype
- MR, mineralocorticoid receptor
- Microglia
- Microglial phenotypes
- NADPH, nicotinamide adenine dinucleotide phosphate
- NFT, neurofibrillary tangles
- Neurodegeneration
- Neuroinflammation
- PS, presenilin
- ROS, reactive oxygen species
- Stress
- Synaptic remodeling
- TGFβ, transforming growth factor β
- TLR, Toll-like receptors
- TMEM119, transmembrane protein 119
- TNFα, tumor necrosis factor-α
- TREM2, triggering receptor expressed in myeloid cells 2
- TYROBP, TYRO protein tyrosine kinase binding protein
- mPFC, medial prefrontal cortex
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Affiliation(s)
- Kanchan Bisht
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Kaushik Sharma
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec, QC, Canada
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29
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Alghamdi BSA. Possible prophylactic anti-excitotoxic and anti-oxidant effects of virgin coconut oil on aluminium chloride-induced Alzheimer’s in rat models. J Integr Neurosci 2018; 17:593-607. [DOI: 10.3233/jin-180089] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Badrah Saeed Ali Alghamdi
- Department of Physiology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
- Neuroscience Unit, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
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30
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Sarasija S, Norman KR. Role of Presenilin in Mitochondrial Oxidative Stress and Neurodegeneration in Caenorhabditis elegans. Antioxidants (Basel) 2018; 7:antiox7090111. [PMID: 30149498 PMCID: PMC6162450 DOI: 10.3390/antiox7090111] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/14/2018] [Accepted: 08/20/2018] [Indexed: 12/31/2022] Open
Abstract
Neurodegenerative diseases like Alzheimer’s disease (AD) are poised to become a global health crisis, and therefore understanding the mechanisms underlying the pathogenesis is critical for the development of therapeutic strategies. Mutations in genes encoding presenilin (PSEN) occur in most familial Alzheimer’s disease but the role of PSEN in AD is not fully understood. In this review, the potential modes of pathogenesis of AD are discussed, focusing on calcium homeostasis and mitochondrial function. Moreover, research using Caenorhabditis elegans to explore the effects of calcium dysregulation due to presenilin mutations on mitochondrial function, oxidative stress and neurodegeneration is explored.
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Affiliation(s)
- Shaarika Sarasija
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY 12208, USA.
| | - Kenneth R Norman
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY 12208, USA.
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31
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Iashchishyn IA, Gruden MA, Moskalenko RA, Davydova TV, Wang C, Sewell RDE, Morozova-Roche LA. Intranasally Administered S100A9 Amyloids Induced Cellular Stress, Amyloid Seeding, and Behavioral Impairment in Aged Mice. ACS Chem Neurosci 2018; 9:1338-1348. [PMID: 29618200 DOI: 10.1021/acschemneuro.7b00512] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Amyloid formation and neuroinflammation are major features of Alzheimer's disease pathology. Proinflammatory mediator S100A9 was shown to act as a link between the amyloid and neuroinflammatory cascades in Alzheimer's disease, leading together with Aβ to plaque formation, neuronal loss and memory impairment. In order to examine if S100A9 alone in its native and amyloid states can induce neuronal stress and memory impairment, we have administered S100A9 species intranasally to aged mice. Single and sequential immunohistochemistry and passive avoidance behavioral test were conducted to evaluate the consequences. Administered S100A9 species induced widespread cellular stress responses in cerebral structures, including frontal lobe, hippocampus and cerebellum. These were manifested by increased levels of S100A9, Bax, and to a lesser extent activated caspase-3 immunopositive cells. Upon administration of S100A9 fibrils, the amyloid oligomerization was observed in the brain tissues, which can further exacerbate cellular stress. The cellular stress responses correlated with significantly increased training and decreased retention latencies measured in the passive avoidance test for the S100A9 treated animal groups. Remarkably, the effect size in the behavioral tests was moderate already in the group treated with native S100A9, while the effect sizes were large in the groups administered S100A9 amyloid oligomers or fibrils. The findings demonstrate the brain susceptibility to neurotoxic damage of S100A9 species leading to behavioral and memory impairments. Intranasal administration of S100A9 species proved to be an effective method to study amyloid induced brain dysfunctions, and S100A9 itself may be postulated as a target to allay early stage neurodegenerative and neuroinflammatory processes.
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Affiliation(s)
- Igor A. Iashchishyn
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå SE-90187, Sweden
- Department of General Chemistry, Sumy State University, Sumy 40007, Ukraine
| | - Marina A. Gruden
- Department of Functional Neurochemistry, P. K. Anokhin Research Institute of Normal Physiology, Moscow 125315, Russia
| | - Roman A. Moskalenko
- Department of Pathology, Sumy State University, Sumy 40007, Ukraine
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå SE-90187, Sweden
| | - Tatiana V. Davydova
- Department of Neuroimmunopathology, Research Institute of General Pathology and Pathophysiology, Moscow 125315, Russia
| | - Chao Wang
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå SE-90187, Sweden
| | - Robert D. E. Sewell
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, United Kingdom
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32
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Haure-Mirande JV, Audrain M, Fanutza T, Kim SH, Klein WL, Glabe C, Readhead B, Dudley JT, Blitzer RD, Wang M, Zhang B, Schadt EE, Gandy S, Ehrlich ME. Deficiency of TYROBP, an adapter protein for TREM2 and CR3 receptors, is neuroprotective in a mouse model of early Alzheimer's pathology. Acta Neuropathol 2017; 134:769-788. [PMID: 28612290 PMCID: PMC5645450 DOI: 10.1007/s00401-017-1737-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/21/2017] [Accepted: 06/02/2017] [Indexed: 01/28/2023]
Abstract
Conventional genetic approaches and computational strategies have converged on immune-inflammatory pathways as key events in the pathogenesis of late onset sporadic Alzheimer’s disease (LOAD). Mutations and/or differential expression of microglial specific receptors such as TREM2, CD33, and CR3 have been associated with strong increased risk for developing Alzheimer’s disease (AD). DAP12 (DNAX-activating protein 12)/TYROBP, a molecule localized to microglia, is a direct partner/adapter for TREM2, CD33, and CR3. We and others have previously shown that TYROBP expression is increased in AD patients and in mouse models. Moreover, missense mutations in the coding region of TYROBP have recently been identified in some AD patients. These lines of evidence, along with computational analysis of LOAD brain gene expression, point to DAP12/TYROBP as a potential hub or driver protein in the pathogenesis of AD. Using a comprehensive panel of biochemical, physiological, behavioral, and transcriptomic assays, we evaluated in a mouse model the role of TYROBP in early stage AD. We crossed an Alzheimer’s model mutant APPKM670/671NL/PSEN1Δexon9(APP/PSEN1) mouse model with Tyrobp−/− mice to generate AD model mice deficient or null for TYROBP (APP/PSEN1; Tyrobp+/− or APP/PSEN1; Tyrobp−/−). While we observed relatively minor effects of TYROBP deficiency on steady-state levels of amyloid-β peptides, there was an effect of Tyrobp deficiency on the morphology of amyloid deposits resembling that reported by others for Trem2−/− mice. We identified modulatory effects of TYROBP deficiency on the level of phosphorylation of TAU that was accompanied by a reduction in the severity of neuritic dystrophy. TYROBP deficiency also altered the expression of several AD related genes, including Cd33. Electrophysiological abnormalities and learning behavior deficits associated with APP/PSEN1 transgenes were greatly attenuated on a Tyrobp-null background. Some modulatory effects of TYROBP on Alzheimer’s-related genes were only apparent on a background of mice with cerebral amyloidosis due to overexpression of mutant APP/PSEN1. These results suggest that reduction of TYROBP gene expression and/or protein levels could represent an immune-inflammatory therapeutic opportunity for modulating early stage LOAD, potentially leading to slowing or arresting the progression to full-blown clinical and pathological LOAD.
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Affiliation(s)
| | - Mickael Audrain
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Tomas Fanutza
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Soong Ho Kim
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - William L Klein
- Department of Biochemistry, Northwestern University, Chicago, IL, 60611, USA
| | - Charles Glabe
- Department of Biochemistry and Molecular Biology, University of California at Irvine, Irvine, CA, 92697, USA
| | - Ben Readhead
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Joel T Dudley
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Robert D Blitzer
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Minghui Wang
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Eric E Schadt
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Sam Gandy
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Department of Psychiatry and Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| | - Michelle E Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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33
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Efthymiou AG, Goate AM. Late onset Alzheimer's disease genetics implicates microglial pathways in disease risk. Mol Neurodegener 2017; 12:43. [PMID: 28549481 PMCID: PMC5446752 DOI: 10.1186/s13024-017-0184-x] [Citation(s) in RCA: 360] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/17/2017] [Indexed: 12/15/2022] Open
Abstract
Alzheimer's disease (AD) is a highly heritable complex disease with no current effective prevention or treatment. The majority of drugs developed for AD focus on the amyloid cascade hypothesis, which implicates Aß plaques as a causal factor in the disease. However, it is possible that other underexplored disease-associated pathways may be more fruitful targets for drug development. Findings from gene network analyses implicate immune networks as being enriched in AD; many of the genes in these networks fall within genomic regions that contain common and rare variants that are associated with increased risk of developing AD. Of these genes, several (including CR1, SPI1, the MS4As, TREM2, ABCA7, CD33, and INPP5D) are expressed by microglia, the resident immune cells of the brain. We summarize the gene network and genetics findings that implicate that these microglial genes are involved in AD, as well as several studies that have looked at the expression and function of these genes in microglia and in the context of AD. We propose that these genes are contributing to AD in a non-Aß-dependent fashion.
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Affiliation(s)
- Anastasia G. Efthymiou
- Department of Neuroscience, Ronald M. Loeb Center for Alzheimer’s disease, Icahn School of Medicine at Mount Sinai, 1425 Madison Ave, New York, NY 10029 USA
| | - Alison M. Goate
- Department of Neuroscience, Ronald M. Loeb Center for Alzheimer’s disease, Icahn School of Medicine at Mount Sinai, 1425 Madison Ave, New York, NY 10029 USA
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34
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Pandya H, Shen MJ, Ichikawa DM, Sedlock AB, Choi Y, Johnson KR, Kim G, Brown MA, Elkahloun AG, Maric D, Sweeney CL, Gossa S, Malech HL, McGavern DB, Park JK. Differentiation of human and murine induced pluripotent stem cells to microglia-like cells. Nat Neurosci 2017; 20:753-759. [PMID: 28253233 PMCID: PMC5404968 DOI: 10.1038/nn.4534] [Citation(s) in RCA: 264] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 02/23/2017] [Indexed: 12/11/2022]
Abstract
Microglia are resident inflammatory cells of the CNS and have important roles in development, homeostasis and a variety of neurologic and psychiatric diseases. Difficulties in procuring human microglia have limited their study and hampered the clinical translation of microglia-based treatments shown to be effective in animal disease models. Here we report the differentiation of human induced pluripotent stem cells (iPSC) into microglia-like cells by exposure to defined factors and co-culture with astrocytes. These iPSC-derived microglia have the phenotype, gene expression profile and functional properties of brain-isolated microglia. Murine iPSC-derived microglia generated using a similar protocol have equivalent efficacy to primary brain-isolated microglia in treatment of murine syngeneic intracranial malignant gliomas. The ability to generate human microglia facilitates the further study of this important CNS cell type and raises the possibility of their use in personalized medicine applications.
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Affiliation(s)
- Hetal Pandya
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Michael J Shen
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - David M Ichikawa
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Andrea B Sedlock
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Yong Choi
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Kory R Johnson
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Gloria Kim
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Mason A Brown
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Abdel G Elkahloun
- National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Dragan Maric
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Colin L Sweeney
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Selamawit Gossa
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Harry L Malech
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Dorian B McGavern
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - John K Park
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA.,Santa Barbara Neuroscience Institute, Santa Barbara, California, USA
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35
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Psychosocial stress on neuroinflammation and cognitive dysfunctions in Alzheimer's disease: the emerging role for microglia? Neurosci Biobehav Rev 2017; 77:148-164. [PMID: 28185874 DOI: 10.1016/j.neubiorev.2017.01.046] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/20/2017] [Accepted: 01/31/2017] [Indexed: 01/22/2023]
Abstract
Chronic psychosocial stress is increasingly recognized as a risk factor for late-onset Alzheimer's disease (LOAD) and associated cognitive deficits. Chronic stress also primes microglia and induces inflammatory responses in the adult brain, thereby compromising synapse-supportive roles of microglia and deteriorating cognitive functions during aging. Substantial evidence demonstrates that failure of microglia to clear abnormally accumulating amyloid-beta (Aβ) peptide contributes to neuroinflammation and neurodegeneration in AD. Moreover, genome-wide association studies have linked variants in several immune genes, such as TREM2 and CD33, the expression of which in the brain is restricted to microglia, with cognitive dysfunctions in LOAD. Thus, inflammation-promoting chronic stress may create a vicious cycle of aggravated microglial dysfunction accompanied by increased Aβ accumulation, collectively exacerbating neurodegeneration. Surprisingly, however, little is known about whether and how chronic stress contributes to microglia-mediated neuroinflammation that may underlie cognitive impairments in AD. This review aims to summarize the currently available clinical and preclinical data and outline potential molecular mechanisms linking stress, microglia and neurodegeneration, to foster future research in this field.
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36
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Daria A, Colombo A, Llovera G, Hampel H, Willem M, Liesz A, Haass C, Tahirovic S. Young microglia restore amyloid plaque clearance of aged microglia. EMBO J 2016; 36:583-603. [PMID: 28007893 DOI: 10.15252/embj.201694591] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 11/24/2016] [Accepted: 11/28/2016] [Indexed: 11/09/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by deposition of amyloid plaques, neurofibrillary tangles, and neuroinflammation. In order to study microglial contribution to amyloid plaque phagocytosis, we developed a novel ex vivo model by co-culturing organotypic brain slices from up to 20-month-old, amyloid-bearing AD mouse model (APPPS1) and young, neonatal wild-type (WT) mice. Surprisingly, co-culturing resulted in proliferation, recruitment, and clustering of old microglial cells around amyloid plaques and clearance of the plaque halo. Depletion of either old or young microglial cells prevented amyloid plaque clearance, indicating a synergistic effect of both populations. Exposing old microglial cells to conditioned media of young microglia or addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) was sufficient to induce microglial proliferation and reduce amyloid plaque size. Our data suggest that microglial dysfunction in AD may be reversible and their phagocytic ability can be modulated to limit amyloid accumulation. This novel ex vivo model provides a valuable system for identification, screening, and testing of compounds aimed to therapeutically reinforce microglial phagocytosis.
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Affiliation(s)
- Anna Daria
- Biomedical Center (BMC), Ludwig-Maximilians Universität München, Munich, Germany
| | - Alessio Colombo
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Gemma Llovera
- Institute for Stroke and dementia research (ISD), Ludwig-Maximilians Universität München, Munich, Germany
| | - Heike Hampel
- Biomedical Center (BMC), Ludwig-Maximilians Universität München, Munich, Germany
| | - Michael Willem
- Biomedical Center (BMC), Ludwig-Maximilians Universität München, Munich, Germany
| | - Arthur Liesz
- Institute for Stroke and dementia research (ISD), Ludwig-Maximilians Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Haass
- Biomedical Center (BMC), Ludwig-Maximilians Universität München, Munich, Germany .,German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
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37
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Bronzuoli MR, Iacomino A, Steardo L, Scuderi C. Targeting neuroinflammation in Alzheimer's disease. J Inflamm Res 2016; 9:199-208. [PMID: 27843334 PMCID: PMC5098782 DOI: 10.2147/jir.s86958] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Almost 47 million people suffer from dementia worldwide, with an estimated new case diagnosed every 3.2 seconds. Alzheimer’s disease (AD) accounts for approximately 60%–80% of all dementia cases. Given this evidence, it is clear dementia represents one of the greatest global public health challenges. Currently used drugs alleviate the symptoms of AD but do not treat the underlying causes of dementia. Hence, a worldwide quest is under way to find new treatments to stop, slow, or even prevent AD. Besides the classic targets of the oldest therapies, represented by cholinergic and glutamatergic systems, β-amyloid (Aβ) plaques, and tau tangles, new therapeutic approaches have other targets. One of the newest and most promising strategies is the control of reactive gliosis, a multicellular response to brain injury. This phenomenon occurs as a consequence of a persistent glial activation, which leads to cellular dysfunctions and neuroinflammation. Reactive gliosis is now considered a key abnormality in the AD brain. It has been demonstrated that reactive astrocytes surround both Aβ plaques and tau tangles. In this condition, glial cells lose some of their homeostatic functions and acquire a proinflammatory phenotype amplifying neuronal damage. So, molecules that are able to restore their physiological functions and control the neuroinflammatory process offer new therapeutic opportunities for this devastating disease. In this review, we describe the role of neuroinflammation in the AD pathogenesis and progression and then provide an overview of the recent research with the aim of developing new therapies to treat this disorder.
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Affiliation(s)
- Maria Rosanna Bronzuoli
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy
| | - Aniello Iacomino
- Faculty of Psychology, University of Rome "G. Marconi", Rome, Italy
| | - Luca Steardo
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy
| | - Caterina Scuderi
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy
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38
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Corrigan F, Arulsamy A, Teng J, Collins-Praino LE. Pumping the Brakes: Neurotrophic Factors for the Prevention of Cognitive Impairment and Dementia after Traumatic Brain Injury. J Neurotrauma 2016; 34:971-986. [PMID: 27630018 DOI: 10.1089/neu.2016.4589] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) is the leading cause of disability and death worldwide, affecting as many as 54,000,000-60,000,000 people annually. TBI is associated with significant impairments in brain function, impacting cognitive, emotional, behavioral, and physical functioning. Although much previous research has focused on the impairment immediately following injury, TBI may have much longer-lasting consequences, including neuropsychiatric disorders and cognitive impairment. TBI, even mild brain injury, has also been recognized as a significant risk factor for the later development of dementia and Alzheimer's disease. Although the link between TBI and dementia is currently unknown, several proposed mechanisms have been put forward, including alterations in glucose metabolism, excitotoxicity, calcium influx, mitochondrial dysfunction, oxidative stress, and neuroinflammation. A treatment for the devastating long-term consequences of TBI is desperately needed. Unfortunately, however, no such treatment is currently available, making this a major area of unmet medical need. Increasing the level of neurotrophic factor expression in key brain areas may be one potential therapeutic strategy. Of the neurotrophic factors, granulocyte-colony stimulating factor (G-CSF) may be particularly effective for preventing the emergence of long-term complications of TBI, including dementia, because of its ability to reduce apoptosis, stimulate neurogenesis, and increase neuroplasticity.
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Affiliation(s)
- Frances Corrigan
- Translational Neuropathology Lab, Discipline of Anatomy and Pathology, School of Medicine, University of Adelaide , Adelaide, Australia
| | - Alina Arulsamy
- Translational Neuropathology Lab, Discipline of Anatomy and Pathology, School of Medicine, University of Adelaide , Adelaide, Australia
| | - Jason Teng
- Translational Neuropathology Lab, Discipline of Anatomy and Pathology, School of Medicine, University of Adelaide , Adelaide, Australia
| | - Lyndsey E Collins-Praino
- Translational Neuropathology Lab, Discipline of Anatomy and Pathology, School of Medicine, University of Adelaide , Adelaide, Australia
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39
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Ali R, Goubran M, Choudhri O, Zeineh MM. Seven-Tesla MRI and neuroimaging biomarkers for Alzheimer's disease. Neurosurg Focus 2016; 39:E4. [PMID: 26646928 DOI: 10.3171/2015.9.focus15326] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The goal of this paper was to review the effectiveness of using 7-T MRI to study neuroimaging biomarkers for Alzheimer's disease (AD). The authors reviewed the literature for articles published to date on the use of 7-T MRI to study AD. Thus far, there are 3 neuroimaging biomarkers for AD that have been studied using 7-T MRI in AD tissue: 1) neuroanatomical atrophy; 2) molecular characterization of hypointensities; and 3) microinfarcts. Seven-Tesla MRI has had mixed results when used to study the 3 aforementioned neuroimaging biomarkers for AD. First, in the detection of neuroanatomical atrophy, 7-T MRI has exciting potential. Historically, noninvasive imaging of neuroanatomical atrophy during AD has been limited by suboptimal resolution. However, now there is compelling evidence that the high resolution of 7-T MRI may help overcome this hurdle. Second, in detecting the characterization of hypointensities, 7-T MRI has had varied success. PET scans will most likely continue to lead in the noninvasive imaging of amyloid plaques; however, there is emerging evidence that 7-T MRI can accurately detect iron deposits within activated microglia, which may help shed light on the role of the immune system in AD pathogenesis. Finally, in the detection of microinfarcts, 7-T MRI may also play a promising role, which may help further elucidate the relationship between cerebrovascular health and AD progression.
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Affiliation(s)
| | - Maged Goubran
- Radiology, Stanford University School of Medicine, Stanford, California
| | | | - Michael M Zeineh
- Radiology, Stanford University School of Medicine, Stanford, California
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40
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Readhead B, Haure-Mirande JV, Zhang B, Haroutunian V, Gandy S, Schadt EE, Dudley JT, Ehrlich ME. Molecular systems evaluation of oligomerogenic APP(E693Q) and fibrillogenic APP(KM670/671NL)/PSEN1(Δexon9) mouse models identifies shared features with human Alzheimer's brain molecular pathology. Mol Psychiatry 2016; 21:1099-111. [PMID: 26552589 PMCID: PMC4862938 DOI: 10.1038/mp.2015.167] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/25/2015] [Accepted: 09/17/2015] [Indexed: 12/20/2022]
Abstract
Identification and characterization of molecular mechanisms that connect genetic risk factors to initiation and evolution of disease pathophysiology represent major goals and opportunities for improving therapeutic and diagnostic outcomes in Alzheimer's disease (AD). Integrative genomic analysis of the human AD brain transcriptome holds potential for revealing novel mechanisms of dysfunction that underlie the onset and/or progression of the disease. We performed an integrative genomic analysis of brain tissue-derived transcriptomes measured from two lines of mice expressing distinct mutant AD-related proteins. The first line expresses oligomerogenic mutant APP(E693Q) inside neurons, leading to the accumulation of amyloid beta (Aβ) oligomers and behavioral impairment, but never develops parenchymal fibrillar amyloid deposits. The second line expresses APP(KM670/671NL)/PSEN1(Δexon9) in neurons and accumulates fibrillar Aβ amyloid and amyloid plaques accompanied by neuritic dystrophy and behavioral impairment. We performed RNA sequencing analyses of the dentate gyrus and entorhinal cortex from each line and from wild-type mice. We then performed an integrative genomic analysis to identify dysregulated molecules and pathways, comparing transgenic mice with wild-type controls as well as to each other. We also compared these results with datasets derived from human AD brain. Differential gene and exon expression analysis revealed pervasive alterations in APP/Aβ metabolism, epigenetic control of neurogenesis, cytoskeletal organization and extracellular matrix (ECM) regulation. Comparative molecular analysis converged on FMR1 (Fragile X Mental Retardation 1), an important negative regulator of APP translation and oligomerogenesis in the post-synaptic space. Integration of these transcriptomic results with human postmortem AD gene networks, differential expression and differential splicing signatures identified significant similarities in pathway dysregulation, including ECM regulation and neurogenesis, as well as strong overlap with AD-associated co-expression network structures. The strong overlap in molecular systems features supports the relevance of these findings from the AD mouse models to human AD.
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Affiliation(s)
- B Readhead
- Department of Genetics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - J-V Haure-Mirande
- Department of Neurology, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - B Zhang
- Department of Genetics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - V Haroutunian
- Department of Psychiatry, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- James J. Peters VA Medical Center, New York, NY, USA
| | - S Gandy
- Department of Neurology, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- James J. Peters VA Medical Center, New York, NY, USA
- Center for Cognitive Health and NFL Neurological Care, Department of Neurology, New York, NY, USA
| | - E E Schadt
- Department of Genetics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - J T Dudley
- Department of Genetics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - M E Ehrlich
- Department of Genetics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neurology, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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41
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Das A, Kim SH, Arifuzzaman S, Yoon T, Chai JC, Lee YS, Park KS, Jung KH, Chai YG. Transcriptome sequencing reveals that LPS-triggered transcriptional responses in established microglia BV2 cell lines are poorly representative of primary microglia. J Neuroinflammation 2016; 13:182. [PMID: 27400875 PMCID: PMC4940985 DOI: 10.1186/s12974-016-0644-1] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 06/27/2016] [Indexed: 12/22/2022] Open
Abstract
Background Microglia are resident myeloid cells in the CNS that are activated by infection, neuronal injury, and inflammation. Established BV2 microglial cell lines have been the primary in vitro models used to study neuroinflammation for more than a decade because they reduce the requirement of continuously maintaining cell preparations and animal experimentation models. However, doubt has recently been raised regarding the value of BV2 cell lines as a model system. Methods We used triplicate RNA sequencing (RNA-seq) to investigate the molecular signature of primary and BV2 microglial cell lines using two transcriptomic techniques: global transcriptomic biological triplicate RNA-seq and quantitative real-time PCR. We analyzed differentially expressed genes (DEGs) to identify transcription factor (TF) motifs (−950 to +50 bp of the 5′ upstream promoters) and epigenetic mechanisms. Results Sequencing assessment and quality evaluation revealed that primary microglia have a distinct transcriptomic signature and express a unique cluster of transcripts in response to lipopolysaccharide. This microglial signature was not observed in BV2 microglial cell lines. Importantly, we observed that previously unidentified TFs (i.e., IRF2, IRF5, IRF8, STAT1, STAT2, and STAT5A) and the epigenetic regulators KDM1A, NSD3, and SETDB2 were significantly and selectively expressed in primary microglia (PM). Although transcriptomic alterations known to occur in BV2 microglial cell lines were identified in PM, we also observed several novel transcriptomic alterations in PM that are not frequently observed in BV2 microglial cell lines. Conclusions Collectively, these unprecedented findings demonstrate that established BV2 microglial cell lines are probably a poor representation of PM, and we establish a resource for future studies of neuroinflammation. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0644-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Amitabh Das
- Institute of Natural Science and Technology, Hanyang University, Ansan, 15588, Republic of Korea
| | - Sun Hwa Kim
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Sarder Arifuzzaman
- Department of Bionanotechnology, Hanyang University, Seoul, 04673, Republic of Korea
| | - Taeho Yoon
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Jin Choul Chai
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Young Seek Lee
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Kyoung Sun Park
- Institute of Natural Science and Technology, Hanyang University, Ansan, 15588, Republic of Korea
| | - Kyoung Hwa Jung
- Institute of Natural Science and Technology, Hanyang University, Ansan, 15588, Republic of Korea.
| | - Young Gyu Chai
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea. .,Department of Bionanotechnology, Hanyang University, Seoul, 04673, Republic of Korea.
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42
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Alam JJ. Selective Brain-Targeted Antagonism of p38 MAPKα Reduces Hippocampal IL-1β Levels and Improves Morris Water Maze Performance in Aged Rats. J Alzheimers Dis 2016; 48:219-27. [PMID: 26401942 PMCID: PMC4923728 DOI: 10.3233/jad-150277] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background: P38 mitogen activated protein kinase (MAPK) α modulates microglia-mediated inflammatory responses and a number of neuronal physiological processes. Objective: To evaluate pre-clinically the pharmacological effects in the brain of p38 MAPKα inhibition with a brain-penetrant specific chemical antagonist. Methods: VX-745, a blood-brain barrier penetrant, highly selective p38 MAPKα inhibitor, and clinical stage investigational drug, was utilized. Initially, a pilot study in 26-month-old Tg2576 mice was conducted. Subsequently, a definitive dose-response study was conducted in aged (20–22 months) rats with identified cognitive deficits; n = 15 per group: vehicle, 0.5, 1.5, and 4.5 mg/kg VX-745 by oral gavage twice daily for 3 weeks. Assessments in aged rats included IL-1β, PSD-95, TNFα protein levels in hippocampus; and Morris water maze (MWM) test for cognitive performance. Results: Drug effect could not be assessed in Tg2576 mice, as little inflammation was evident. In cognitively-impaired aged rats, VX-745 led to significantly improved performance in the MWM and significant reduction in hippocampal IL-1β protein levels, though the effects were dissociated as the MWM effect was evident at a lower dose level than that required to lower IL-1β. Drug concentration-effect relationships and predicted human doses were determined. Conclusions: Selective inhibition of p38 MAPKα with VX-745 in aged rats reduces hippocampal IL-1β levels and improves performance in the MWM. As the two effects occur at different dose levels, the behavioral effect appears to be via a mechanism that is independent of reducing cytokine production. The predicted human doses should minimize risks of systemic toxicity.
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Affiliation(s)
- John J. Alam
- Correspondence to: John J. Alam, MD, EIP Pharma, LLC, 11 Channing Street, Cambridge, MA 02138, USA. Tel.: +1 617 909 5737;
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43
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Freudenberg-Hua Y, Li W, Abhyankar A, Vacic V, Cortes V, Ben-Avraham D, Koppel J, Greenwald B, Germer S, Darnell RB, Barzilai N, Freudenberg J, Atzmon G, Davies P. Differential burden of rare protein truncating variants in Alzheimer's disease patients compared to centenarians. Hum Mol Genet 2016; 25:3096-3105. [PMID: 27260402 DOI: 10.1093/hmg/ddw150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 05/06/2016] [Accepted: 05/13/2016] [Indexed: 12/31/2022] Open
Abstract
We compared coding region variants of 53 cognitively healthy centenarians and 45 patients with Alzheimer's disease (AD), all of Ashkenazi Jewish (AJ) ancestry. Despite the small sample size, the known AD risk variant APOE4 reached genome-wide significance, indicating the advantage of utilizing 'super-controls'. We restricted our subsequent analysis to rare variants observed at most once in the 1000 Genomes database and having a minor allele frequency below 2% in our AJ sample. We compared the burden of predicted protein altering variants between cases and controls as normalized by the level of rare synonymous variants. We observed an increased burden among AD subjects for predicted loss-of-function (LoFs) variants defined as stop-gain, frame shift, initiation codon (INIT) and splice site mutations (n = 930, OR = 1.3, P = 1.5×E-5). There was no enrichment across all rare protein altering variants defined as missense plus LoFs, in frame indels and stop-loss variants (n = 13 014, OR = 0.97, P = 0.47). Among LoFs, the strongest burden was observed for INIT (OR = 2.16, P = 0.0097) and premature stop variants predicted to cause non-sense-mediated decay in the majority of transcripts (NMD) (OR = 1.98, P = 0.02). Notably, this increased burden of NMD, INIT and splice variants was more pronounced in a set of 1397 innate immune genes (OR = 4.55, P = 0.0043). Further comparison to additional exomes indicates that the difference in LoF burden originated both from the AD and centenarian sample. In summary, we observed an overall increased burden of rare LoFs in AD subjects as compared to centenarians, and this enrichment is more pronounced for innate immune genes.
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Affiliation(s)
- Yun Freudenberg-Hua
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA .,Division of Geriatric Psychiatry, Zucker Hillside Hospital, Northwell Health, Glen Oaks, NY 11004, USA
| | - Wentian Li
- Robert S Boas Center for Genomics and Human Genetics, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA
| | | | | | - Vanessa Cortes
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA
| | - Danny Ben-Avraham
- Institute for Aging Research and the Diabetes Research Center, Department of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jeremy Koppel
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA
| | - Blaine Greenwald
- Division of Geriatric Psychiatry, Zucker Hillside Hospital, Northwell Health, Glen Oaks, NY 11004, USA
| | | | | | | | - Nir Barzilai
- Institute for Aging Research and the Diabetes Research Center, Department of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jan Freudenberg
- Robert S Boas Center for Genomics and Human Genetics, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA.,The Regeneron Genetics Center, Tarrytown, NY 10591, USA and
| | - Gil Atzmon
- Institute for Aging Research and the Diabetes Research Center, Department of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.,Faculty of Natural Sciences, University of Haifa, Haifa 31905, Israel
| | - Peter Davies
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA
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44
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Yerbury J, Bean D, Favrin G. Network Approaches to the Understanding of Alzheimer's Disease: From Model Organisms to Humans. Methods Mol Biol 2016; 1303:447-458. [PMID: 26235084 DOI: 10.1007/978-1-4939-2627-5_27] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
It is becoming increasingly evident that Alzheimer's disease cannot be considered as the outcome of a single pathway, but rather we should view it as a system, that is, a network of interactions between large numbers of different protein molecules. In the last few years, probably because of the inherent limitations of traditional methods and because of the great increase in availability of sequencing data, this type of approach is being used more and more. In the following, we will discuss what constitutes a "network approach," what are its pros and cons, a number of recent case studies and finally what are the future perspectives of this type of analysis.
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Affiliation(s)
- Justin Yerbury
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia
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45
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Ghosh S, Geahlen RL. Stress Granules Modulate SYK to Cause Microglial Cell Dysfunction in Alzheimer's Disease. EBioMedicine 2015; 2:1785-98. [PMID: 26870803 PMCID: PMC4740304 DOI: 10.1016/j.ebiom.2015.09.053] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/21/2015] [Accepted: 09/30/2015] [Indexed: 12/13/2022] Open
Abstract
Microglial cells in the brains of Alzheimer's patients are known to be recruited to amyloid-beta (Aβ) plaques where they exhibit an activated phenotype, but are defective for plaque removal by phagocytosis. In this study, we show that microglia stressed by exposure to sodium arsenite or Aβ(1–42) peptides or fibrils form extensive stress granules (SGs) to which the tyrosine kinase, SYK, is recruited. SYK enhances the formation of SGs, is active within the resulting SGs and stimulates the production of reactive oxygen and nitrogen species that are toxic to neuronal cells. This sequestration of SYK inhibits the ability of microglial cells to phagocytose Escherichia coli or Aβ fibrils. We find that aged microglial cells are more susceptible to the formation of SGs; and SGs containing SYK and phosphotyrosine are prevalent in the brains of patients with severe Alzheimer's disease. Phagocytic activity can be restored to stressed microglial cells by treatment with IgG, suggesting a mechanism to explain the therapeutic efficacy of intravenous IgG. These studies describe a mechanism by which stress, including exposure to Aβ, compromises the function of microglial cells in Alzheimer's disease and suggest approaches to restore activity to dysfunctional microglial cells. Chronic stress promotes the formation of large, persistent stress granules in microglial cells. SYK is recruited to stress granules, which promotes inflammatory responses and inhibits phagocytosis. Phagocytic activity of stressed cells can be recovered by treatment with IgG.
Microglial cells in the brains of patients with Alzheimer's disease are activated, but are defective at phagocytosis of amyloid plaques. Activation and phagocytosis require the SYK tyrosine kinase. Chronic exposure to amyloid-beta promotes the formation of persistent stress granules to which active SYK binds and these are found in the brains of patients with severe Alzheimer's disease. This activation and sequestration of SYK promotes inflammation and inhibits phagocytosis. Phagocytic activity can be recovered by treatment with IgG, which causes a redistribution of SYK within the cell, suggesting potential therapeutic approaches to restoring microglial cell function to diseased or aged brains.
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Affiliation(s)
- Soumitra Ghosh
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA
| | - Robert L Geahlen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA
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46
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Xiong JY, Li SC, Sun YX, Zhang XS, Dong ZZ, Zhong P, Sun XR. Long-term treadmill exercise improves spatial memory of male APPswe/PS1dE9 mice by regulation of BDNF expression and microglia activation. Biol Sport 2015; 32:295-300. [PMID: 26681831 PMCID: PMC4672160 DOI: 10.5604/20831862.1163692] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 01/30/2015] [Accepted: 05/22/2015] [Indexed: 12/28/2022] Open
Abstract
Increasing evidence suggests that physical activity could delay or attenuate the symptoms of Alzheimer's disease (AD). But the underlying mechanisms are still not fully understood. To investigate the effect of long-term treadmill exercise on the spatial memory of AD mice and the possible role of β-amyloid, brain-derived neurotrophic factor (BDNF) and microglia in the effect, male APPswe/PS1dE9 AD mice aged 4 months were subjected to treadmill exercise for 5 months with 6 sessions per week and gradually increased load. A Morris water maze was used to evaluate the spatial memory. Expression levels of β-amyloid, BDNF and Iba-1 (a microglia marker) in brain tissue were detected by immunohistochemistry. Sedentary AD mice and wildtype C57BL/6J mice served as controls. The results showed that 5-month treadmill exercise significantly decreased the escape latencies (P < 0.01 on the 4th day) and improved the spatial memory of the AD mice in the water maze test. Meanwhile, treadmill exercise significantly increased the number of BDNF-positive cells and decreased the ratios of activated microglia in both the cerebral cortex and the hippocampus. However, treadmill exercise did not significantly alleviate the accumulation of β-amyloid in either the cerebral cortex or the hippocampus of the AD mice (P > 0.05). The study suggested that long-term treadmill exercise could improve the spatial memory of the male APPswe/PS1dE9 AD mice. The increase in BDNF-positive cells and decrease in activated microglia might underpin the beneficial effect.
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Affiliation(s)
- J Y Xiong
- School of Physical Education, Lingnan Normal University, Zhanjiang 524048, China ; Equal contribution
| | - S C Li
- School of Physical Education, Lingnan Normal University, Zhanjiang 524048, China ; Equal contribution
| | - Y X Sun
- Library of Mudanjiang Medical University, Mudanjiang 157011, China ; Equal contribution
| | - X S Zhang
- School of Physical Education, Lingnan Normal University, Zhanjiang 524048, China ; Equal contribution
| | - Z Z Dong
- The Second Affiliated Hospital, Wenzhou Medical University, Wenzhou 325200, China
| | - P Zhong
- Laboratory of Physiological Science, Guangdong Medical University, Dongguan 523808, China
| | - X R Sun
- Key Laboratory for Medical Molecular Diagnostics of Guangdong Province, Guangdong Medical University, Dongguan 523808, China ; Institute of Aging Research, Dongguan Scientific Center, Guangdong Medical University, Dongguan 523808, China
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47
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Abstract
The past two decades of research into the pathogenesis of Alzheimer disease (AD) have been driven largely by the amyloid hypothesis; the neuroinflammation that is associated with AD has been assumed to be merely a response to pathophysiological events. However, new data from preclinical and clinical studies have established that immune system-mediated actions in fact contribute to and drive AD pathogenesis. These insights have suggested both novel and well-defined potential therapeutic targets for AD, including microglia and several cytokines. In addition, as inflammation in AD primarily concerns the innate immune system - unlike in 'typical' neuroinflammatory diseases such as multiple sclerosis and encephalitides - the concept of neuroinflammation in AD may need refinement.
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48
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Luo W, Liu W, Hu X, Hanna M, Caravaca A, Paul SM. Microglial internalization and degradation of pathological tau is enhanced by an anti-tau monoclonal antibody. Sci Rep 2015; 5:11161. [PMID: 26057852 PMCID: PMC4460904 DOI: 10.1038/srep11161] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 05/18/2015] [Indexed: 12/31/2022] Open
Abstract
Microglia have been shown to contribute to the clearance of brain amyloid β peptides (Aβ), the major component of amyloid plaques, in Alzheimer's disease (AD). However, it is not known whether microglia play a similar role in the clearance of tau, the major component of neurofibrillary tangles (NFTs). We now report that murine microglia rapidly internalize and degrade hyperphosphorylated pathological tau isolated from AD brain tissue in a time-dependent manner in vitro. We further demonstrate that microglia readily degrade human tau species released from AD brain sections and eliminate NFTs from brain sections of P301S tauopathy mice. The anti-tau monoclonal antibody MC1 enhances microglia-mediated tau degradation in an Fc-dependent manner. Our data identify a potential role for microglia in the degradation and clearance of pathological tau species in brain and provide a mechanism explaining the potential therapeutic actions of passively administered anti-tau monoclonal antibodies.
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Affiliation(s)
- Wenjie Luo
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, 413 East 69th Street, New York, NY10021
| | - Wencheng Liu
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, 413 East 69th Street, New York, NY10021
| | - Xiaoyan Hu
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, 413 East 69th Street, New York, NY10021
| | - Mary Hanna
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, 413 East 69th Street, New York, NY10021
| | - April Caravaca
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, 413 East 69th Street, New York, NY10021
| | - Steven M Paul
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, 413 East 69th Street, New York, NY10021
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49
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Zeineh MM, Chen Y, Kitzler HH, Hammond R, Vogel H, Rutt BK. Activated iron-containing microglia in the human hippocampus identified by magnetic resonance imaging in Alzheimer disease. Neurobiol Aging 2015; 36:2483-500. [PMID: 26190634 DOI: 10.1016/j.neurobiolaging.2015.05.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 05/27/2015] [Accepted: 05/30/2015] [Indexed: 01/02/2023]
Abstract
Although amyloid plaques and neurofibrillary pathology play important roles in Alzheimer disease (AD), our understanding of AD is incomplete, and the contribution of microglia and iron to neurodegeneration is unknown. High-field magnetic resonance imaging (MRI) is exquisitely sensitive to microscopic iron. To explore iron-associated neuroinflammatory AD pathology, we studied AD and control human brain specimens by (1) performing ultra-high resolution ex vivo 7 Tesla MRI, (2) coregistering the MRI with successive histologic staining for iron, microglia, amyloid beta, and tau, and (3) quantifying the relationship between magnetic resonance signal intensity and histological staining. In AD, we identified numerous small MR hypointensities primarily within the subiculum that were best explained by the combination of microscopic iron and activated microglia (p = 0.025), in contradistinction to the relatively lesser contribution of tau or amyloid. Neuropathologically, this suggests that microglial-mediated neurodegeneration may occur in the hippocampal formation in AD and is detectable by ultra-high resolution MRI.
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Affiliation(s)
- Michael M Zeineh
- Department of Radiology, Lucas Center for Imaging, Stanford University, Stanford, CA, USA.
| | - Yuanxin Chen
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada
| | - Hagen H Kitzler
- Department of Neuroradiology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Robert Hammond
- Department of Pathology and Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Hannes Vogel
- Department of Pathology, Stanford University, Stanford, CA, USA
| | - Brian K Rutt
- Department of Radiology, Lucas Center for Imaging, Stanford University, Stanford, CA, USA
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50
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Thal DR, Walter J, Saido TC, Fändrich M. Neuropathology and biochemistry of Aβ and its aggregates in Alzheimer's disease. Acta Neuropathol 2015; 129:167-82. [PMID: 25534025 DOI: 10.1007/s00401-014-1375-y] [Citation(s) in RCA: 194] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 12/09/2014] [Accepted: 12/13/2014] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is characterized by β-amyloid plaques and intraneuronal τ aggregation usually associated with cerebral amyloid angiopathy (CAA). Both β-amyloid plaques and CAA deposits contain fibrillar aggregates of the amyloid β-peptide (Aβ). Aβ plaques and CAA develop first in neocortical areas of preclinical AD patients and, then, expand in a characteristic sequence into further brain regions with end-stage pathology in symptomatic AD patients. Aβ aggregates are not restricted to amyloid plaques and CAA. Soluble and several types of insoluble non-plaque- and non-CAA-associated Aβ aggregates have been described. Amyloid fibrils are products of a complex self-assembly process that involves different types of transient intermediates. Amongst these intermediate species are protofibrils and oligomers. Different variants of Aβ peptides may result from alternative processing or from mutations that lead to rare forms of familial AD. These variants can exhibit different self-assembly and aggregation properties. In addition, several post-translational modifications of Aβ have been described that result, for example, in the production of N-terminal truncated Aβ with pyroglutamate modification at position 3 (AβN3pE) or of Aβ phosphorylated at serine 8 (pSer8Aβ). Both AβN3pE and pSer8Aβ show enhanced aggregation into oligomers and fibrils. However, the earliest detectable soluble and insoluble Aβ aggregates in the human brain exhibit non-modified Aβ, whereas AβN3pE and pSer8Aβ are detected in later stages. This finding indicates the existence of different biochemical stages of Aβ aggregate maturation with pSer8Aβ being related mainly to cases with symptomatic AD. The conversion from preclinical to symptomatic AD could thereby be related to combined effects of increased Aβ concentration, maturation of aggregates and spread of deposits into additional brain regions. Thus, the inhibition of Aβ aggregation and maturation before entering the symptomatic stage of the disease as indicated by the accumulation of pSer8Aβ may represent an attractive treatment strategy for preventing disease progression.
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