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Rashidbenam Z, Ozturk E, Pagnin M, Theotokis P, Grigoriadis N, Petratos S. How does Nogo receptor influence demyelination and remyelination in the context of multiple sclerosis? Front Cell Neurosci 2023; 17:1197492. [PMID: 37361998 PMCID: PMC10285164 DOI: 10.3389/fncel.2023.1197492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/15/2023] [Indexed: 06/28/2023] Open
Abstract
Multiple sclerosis (MS) can progress with neurodegeneration as a consequence of chronic inflammatory mechanisms that drive neural cell loss and/or neuroaxonal dystrophy in the central nervous system. Immune-mediated mechanisms can accumulate myelin debris in the disease extracellular milieu during chronic-active demyelination that can limit neurorepair/plasticity and experimental evidence suggests that potentiated removal of myelin debris can promote neurorepair in models of MS. The myelin-associated inhibitory factors (MAIFs) are integral contributors to neurodegenerative processes in models of trauma and experimental MS-like disease that can be targeted to promote neurorepair. This review highlights the molecular and cellular mechanisms that drive neurodegeneration as a consequence of chronic-active inflammation and outlines plausible therapeutic approaches to antagonize the MAIFs during the evolution of neuroinflammatory lesions. Moreover, investigative lines for translation of targeted therapies against these myelin inhibitors are defined with an emphasis on the chief MAIF, Nogo-A, that may demonstrate clinical efficacy of neurorepair during progressive MS.
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Affiliation(s)
- Zahra Rashidbenam
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Ezgi Ozturk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Maurice Pagnin
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Paschalis Theotokis
- Laboratory of Experimental Neurology and Neuroimmunology, Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Nikolaos Grigoriadis
- Laboratory of Experimental Neurology and Neuroimmunology, Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Steven Petratos
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
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2
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Jiang R, Chi XD, Jing Y, Wang B, Li S. Reduction of NgR in perforant path protects neuronal morphology and function in APP/PS1 transgenic mice. Aging (Albany NY) 2023; 15:2158-2169. [PMID: 36961417 PMCID: PMC10085588 DOI: 10.18632/aging.204605] [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: 12/16/2021] [Accepted: 03/23/2022] [Indexed: 03/25/2023]
Abstract
Neuronal loss is the central abnormality occurring in brains suffering from Alzheimer's disease (AD). The notion that AD causes the death of neurons point towards protection of neuronal morphology and function as important therapeutic strategies. The perforant path projections from the entorhinal cortex to the dentate gyrus is the most vulnerable circuit with respect to AD. It's known that the perforant path is a very important structure for synaptic plasticity and cognitive functions. NgR (Nogo receptor) is not only involved in limiting injury-induced axonal growth but also in pathological features of AD. So, the mechanism of how NgR affects the perforant path needs further investigation. In this study, the effect of NgR in the perforant path on the neuronal morphology and function in APP/PS1 transgenic mice was studied. The results showed that downregulation of NgR in perforant path ameliorate the damaged morphology and decreased number of neurons in APP/PS1 mice. Concurrently, NgR knockdown enhanced dendritic complexity and increased postsynaptic protein density in APP/PS1 mice. Furthermore, the RT-PCR results indicated that there is downregulation of M1 phenotypes of microglial gene expression in the hippocampus of TG-shNgR mice. Our study suggests that NgR plays a critical role in microglial phenotype polarization, which might account for the NgR knockdown in the perforant path initiated a decrease in neuronal death and improved synaptic function. Our study provided a better understanding of the perforant path and the role of NgR in AD pathogenesis, thus offering the potential application of hippocampal neurons in treatment of AD.
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Affiliation(s)
- Rong Jiang
- Department of Physiology, Binzhou Medical University, Yantai Campus, Yantai, China
| | - Xiao-Dong Chi
- Department of Neurology, Affiliated Dalian Friendship Hospital of Dalian Medical University, Dalian, China
| | - Yulong Jing
- Department of Traumatic Orthopedics, Yantaishan Hospital, Yantai, China
| | - Bin Wang
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Shao Li
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
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Wang J, Qin X, Sun H, He M, Lv Q, Gao C, He X, Liao H. Nogo receptor impairs the clearance of fibril amyloid-β by microglia and accelerates Alzheimer's-like disease progression. Aging Cell 2021; 20:e13515. [PMID: 34821024 PMCID: PMC8672787 DOI: 10.1111/acel.13515] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 07/21/2021] [Accepted: 10/06/2021] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by the progressive accumulation of β‐amyloid (Aβ)‐containing amyloid plaques, and microglia play a critical role in mediating Aβ clearance. Mounting evidence has confirmed that the ability of microglia in clearing Aβ decreased with aging and AD progress, but the underlying mechanisms are unclear. Previously, we have demonstrated that Nogo receptor (NgR), a receptor for three axon growth inhibitors associated with myelin, can decrease adhesion and migration of microglia to fibrils Aβ with aging. However, whether NgR expressed on microglia affect microglia phagocytosis of fibrils Aβ with aging remains unclear. Here, we found that aged but not young microglia showed increased NgR expression and decreased Aβ phagocytosis in APP/PS1 transgenic mice. NgR knockdown APP/PS1 mice showed simultaneous reduced amyloid burden and improved spatial learning and memory, which were associated with increased Aβ clearance. Importantly, Nogo‐P4, an agonist of NgR, enhanced the protein level of p‐Smad2/3, leading to a significant transcriptional inhibition of CD36 gene expression, which in turn decreased the microglial phagocytosis of Aβ. Moreover, ROCK accounted for Nogo‐P4‐induced activation of Smad2/3 signaling. Finally, the decreasing effect of NgR on microglial Aβ uptake was confirmed in a mouse model of intra‐hippocampal fAβ injection. Our findings suggest that NgR may play an important role in the regulation of Aβ homeostasis, and has potential as a therapeutic target for AD.
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Affiliation(s)
- Jianing Wang
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
| | - Xiaoying Qin
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
| | - Hao Sun
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
| | - Meijun He
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
| | - Qunyu Lv
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
| | - Congcong Gao
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
| | - Xinran He
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
| | - Hong Liao
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical University 24 Tongjiaxiang Street Nanjing 210009 China
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4
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Lao K, Zhang R, Luan J, Zhang Y, Gou X. Therapeutic Strategies Targeting Amyloid-β Receptors and Transporters in Alzheimer's Disease. J Alzheimers Dis 2021; 79:1429-1442. [PMID: 33459712 DOI: 10.3233/jad-200851] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease that has been recognized as one of the most intractable medical problems with heavy social and economic costs. Amyloid-β (Aβ) has been identified as a major factor that participates in AD progression through its neurotoxic effects. The major mechanism of Aβ-induced neurotoxicity is by interacting with membrane receptors and subsequent triggering of aberrant cellular signaling. Besides, Aβ transporters also plays an important role by affecting Aβ homeostasis. Thus, these Aβ receptors and transporters are potential targets for the development of AD therapies. Here, we summarize the reported therapeutic strategies targeting Aβ receptors and transporters to provide a molecular basis for future rational design of anti-AD agents.
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Affiliation(s)
- Kejing Lao
- Institute of Basic and Translational Medicine & Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, PR China
| | - Ruisan Zhang
- Institute of Basic and Translational Medicine & Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, PR China
| | - Jing Luan
- Institute of Basic and Translational Medicine & Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, PR China
| | - Yuelin Zhang
- Institute of Basic and Translational Medicine & Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, PR China
| | - Xingchun Gou
- Institute of Basic and Translational Medicine & Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, PR China
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The Implication of Reticulons (RTNs) in Neurodegenerative Diseases: From Molecular Mechanisms to Potential Diagnostic and Therapeutic Approaches. Int J Mol Sci 2021; 22:ijms22094630. [PMID: 33924890 PMCID: PMC8125174 DOI: 10.3390/ijms22094630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 02/07/2023] Open
Abstract
Reticulons (RTNs) are crucial regulatory factors in the central nervous system (CNS) as well as immune system and play pleiotropic functions. In CNS, RTNs are transmembrane proteins mediating neuroanatomical plasticity and functional recovery after central nervous system injury or diseases. Moreover, RTNs, particularly RTN4 and RTN3, are involved in neurodegeneration and neuroinflammation processes. The crucial role of RTNs in the development of several neurodegenerative diseases, including Alzheimer's disease (AD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or other neurological conditions such as brain injury or spinal cord injury, has attracted scientific interest. Reticulons, particularly RTN-4A (Nogo-A), could provide both an understanding of early pathogenesis of neurodegenerative disorders and be potential therapeutic targets which may offer effective treatment or inhibit disease progression. This review focuses on the molecular mechanisms and functions of RTNs and their potential usefulness in clinical practice as a diagnostic tool or therapeutic strategy.
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Xie QQ, Feng X, Huang YΥ, Fang N, Yi H, Wang ZJ, Cao QΥ, Lou GF, Pan JP, Hu Y, Li FC, Zheng Q, Xiao F. Nogo‑66 promotes β‑amyloid protein secretion via NgR/ROCK‑dependent BACE1 activation. Mol Med Rep 2021; 23:188. [PMID: 33495810 PMCID: PMC7809900 DOI: 10.3892/mmr.2021.11827] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 12/02/2020] [Indexed: 01/02/2023] Open
Abstract
The generation of β-amyloid protein (Aβ) is considered a key step in the pathogenesis of Alzheimer's disease (AD) and the regulation of its production is an important therapeutic strategy. It was hypothesized in the present study that Nogo-A may be involved in AD and may regulate the generation of Aβ. Nogo-A is known to act as a major inhibitor of neuron regeneration in the adult central nervous system. A recent study indicated that Nogo-A is associated with AD; however, the underlying effect and molecular mechanisms remain largely elusive. In the present study, the potential effects of Nogo-A on AD were investigated. ELISA was used to detect the levels of Aβ, enzymatic activity detection kits were used to determine the activity of secretase enzymes in amyloid precursor protein (APP) metabolism, and western blot analysis was used to detect the expression levels of proteins associated with the APP processing and Nogo-A/Nogo-66 receptor (NgR) signaling pathways. The results revealed that Nogo-66, the major inhibitory region of Nogo-A, promoted neuronal Aβ secretion by increasing the activity of β-secretase 1 via the NgR/Rho-associated coiled-coil containing kinases pathway in a dose-dependent manner. The present data suggested that Nogo-A may facilitate the onset and development of AD by promoting Aβ secretion, providing information on a potential novel target for AD therapy.
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Affiliation(s)
- Qing-Qing Xie
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Xiao Feng
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Yi-Υun Huang
- Department of Microbiology and Biochemical Pharmacy, School of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Nian Fang
- Department of Microbiology and Biochemical Pharmacy, School of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Hua Yi
- Department of Pathology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 511436, P.R. China
| | - Zi-Jian Wang
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Qiao-Υu Cao
- Department of Microbiology and Biochemical Pharmacy, School of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Guo-Feng Lou
- Department of Clinical Molecular Biology, Akershus University Hospital, University of Oslo, 1478 Lørenskog, Norway
| | - Jun-Ping Pan
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Yang Hu
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Fang-Cheng Li
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510632, P.R. China
| | - Qing Zheng
- Department of Microbiology and Biochemical Pharmacy, School of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Fei Xiao
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
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Abstract
Folding of proteins is essential so that they can exert their functions. For proteins that transit the secretory pathway, folding occurs in the endoplasmic reticulum (ER) and various chaperone systems assist in acquiring their correct folding/subunit formation. N-glycosylation is one of the most conserved posttranslational modification for proteins, and in eukaryotes it occurs in the ER. Consequently, eukaryotic cells have developed various systems that utilize N-glycans to dictate and assist protein folding, or if they consistently fail to fold properly, to destroy proteins for quality control and the maintenance of homeostasis of proteins in the ER.
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8
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Abstract
Nogo-A is considered one of the most important inhibitors of myelin-associated axonal regeneration in the central nervous system. It is mainly expressed by oligodendrocytes. Although previous studies have found regulatory roles for Nogo-A in neurite outgrowth inhibition, neuronal homeostasis, precursor migration, plasticity, and neurodegeneration, its functions in the process of oxidative injury are largely uncharacterized. In this study, oligodendrocytes were extracted from the cerebral cortex of newborn Sprague-Dawley rats. We used hydrogen peroxide (H2O2) to induce an in vitro oligodendrocyte oxidative damage model and found that endogenously expressed Nogo-A is significantly upregulated in oligodendrocytes. After recombinant virus Ad-ZsGreen-rat Nogo-A infection of oligodendrocytes, Nogo-A expression was increased, and the infected oligodendrocytes were more susceptible to acute oxidative insults and exhibited a markedly elevated rate of cell death. Furthermore, knockdown of Nogo-A expression in oligodendrocytes by Ad-ZsGreen-shRNA-Nogo-A almost completely protected against oxidative stress induced by exogenous H2O2. Intervention with a Nogo-66 antibody, a LINGO1 blocker, or Y27632, an inhibitor in the Nogo-66-NgR/p75/LINGO-1-RhoA-ROCK pathway, did not affect the death of oligodendrocytes. Ad-ZsGreen-shRNA-Nogo-A also increased the levels of phosphorylated extracellular signal-regulated kinase 1/2 and inhibited BCL2 expression in oligodendrocytes. In conclusion, Nogo-A aggravated reactive oxygen species damage in oligodendrocytes, and phosphorylated extracellular signal-regulated kinase 1/2 and BCL2 might be involved in this process. This study was approved by the Ethics Committee of Peking University People’s Hospital, China (approval No. 2018PHC081) on December 18, 2018.
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Affiliation(s)
- Yang-Yang Wang
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Na Han
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Dao-Jun Hong
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Jun Zhang
- Department of Neurology, Peking University People's Hospital, Beijing, China
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El Bitar F, Al Sudairy N, Qadi N, Al Rajeh S, Alghamdi F, Al Amari H, Al Dawsari G, Alsubaie S, Al Sudairi M, Abdulaziz S, Al Tassan N. A Comprehensive Analysis of Unique and Recurrent Copy Number Variations in Alzheimer's Disease and its Related Disorders. Curr Alzheimer Res 2020; 17:926-938. [PMID: 33256577 DOI: 10.2174/1567205017666201130111424] [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: 04/25/2020] [Revised: 08/20/2020] [Accepted: 10/29/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Copy number variations (CNVs) play an important role in the genetic etiology of various neurological disorders, including Alzheimer's disease (AD). Type 2 diabetes mellitus (T2DM) and major depressive disorder (MDD) were shown to have share mechanisms and signaling pathways with AD. OBJECTIVE We aimed to assess CNVs regions that may harbor genes contributing to AD, T2DM, and MDD in 67 Saudi familial and sporadic AD patients, with no alterations in the known genes of AD and genotyped previously for APOE. METHODS DNA was analyzed using the CytoScan-HD array. Two layers of filtering criteria were applied. All the identified CNVs were checked in the Database of Genomic Variants (DGV). RESULTS A total of 1086 CNVs (565 gains and 521 losses) were identified in our study. We found 73 CNVs harboring genes that may be associated with AD, T2DM or MDD. Nineteen CNVs were novel. Most importantly, 42 CNVs were unique in our studied cohort existing only in one patient. Two large gains on chromosomes 1 and 13 harbored genes implicated in the studied disorders. We identified CNVs in genes that encode proteins involved in the metabolism of amyloid-β peptide (AGRN, APBA2, CR1, CR2, IGF2R, KIAA0125, MBP, RER1, RTN4R, VDR and WISPI) or Tau proteins (CACNAIC, CELF2, DUSP22, HTRA1 and SLC2A14). CONCLUSION The present work provided information on the presence of CNVs related to AD, T2DM, and MDD in Saudi Alzheimer's patients.
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Affiliation(s)
- Fadia El Bitar
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nourah Al Sudairy
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Najeeb Qadi
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | | | - Fatimah Alghamdi
- Institute of Biology and Environmental Research, National Center for Biotechnology, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Hala Al Amari
- Institute of Biology and Environmental Research, National Center for Biotechnology, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Ghadeer Al Dawsari
- Institute of Biology and Environmental Research, National Center for Genomics Technology, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Sahar Alsubaie
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mishael Al Sudairi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sara Abdulaziz
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nada Al Tassan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
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Jiang R, Wu XF, Wang B, Guan RX, Lv LM, Li AP, Lei L, Ma Y, Li N, Li QF, Ma QH, Zhao J, Li S. Reduction of NgR in perforant path decreases amyloid-β peptide production and ameliorates synaptic and cognitive deficits in APP/PS1 mice. Alzheimers Res Ther 2020; 12:47. [PMID: 32331528 PMCID: PMC7181577 DOI: 10.1186/s13195-020-00616-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 04/07/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Amyloid beta (Aβ) which is recognized as a main feature of Alzheimer's disease (AD) has been proposed to "spread" through anatomically and functionally connected brain regions. The entorhinal cortex and perforant path are the earliest affected brain regions in AD. The perforant path is the most vulnerable circuit in the cortex with respect to both aging and AD. Previous data show that the origins and terminations of the perforant path are susceptible to amyloid deposition at the younger age in AD. Nogo receptor (NgR) plays an essential role in limiting injury-induced axonal growth and experience-dependent plasticity in the adult brain. It has been suggested that NgR is involved in AD pathological features, but the results have been conflicting and the detailed mechanism needs further investigation. In this study, the effect of NgR in the perforant path on the pathological and functional phenotype of APP/PS1 transgenic mice was studied. METHODS To genetically manipulate NgR expression, adeno-associated virus (AAV) with short hairpin (shRNA) against NgR was injected into the perforant path of APP/PS1 transgenic mice, followed by an assessment of behavioral, synaptic plasticity and neuropathological phenotypes. NgR was overexpressed or knockdown in neuroblastoma N2a cells and APPswe/HEK293 cells to investigate the interaction between NgR and amyloid precursor protein (APP). RESULTS It is shown that reduction of NgR in the perforant path rescued cognitive and synaptic deficits in APP/PS1 transgenic mice. Concurrently, Aβ production in the perforant path and levels of soluble Aβ and amyloid plaques in the hippocampus were significantly decreased. There was a positive correlation between the total APP protein level and NgR expression both in transgenic mice and in cultured cells, where the α-secretase and β-secretase cleavage products both changed with APP level in parallel. Finally, NgR might inhibit APP degradation through lysosome by Rho/Rho-associated protein kinases (ROCK) signaling pathway. CONCLUSIONS Our findings demonstrate that perforant path NgR plays an important role in regulating APP/Aβ level and cognitive functions in AD transgenic mice, which might be related to the suppression of APP degradation by NgR. Our study suggests that NgR in the perforant path could be a potential target for modulating AD progression.
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Affiliation(s)
- Rong Jiang
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Xue-Fei Wu
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Bin Wang
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Rong-Xiao Guan
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Lang-Man Lv
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Ai-Ping Li
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Lei Lei
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Ye Ma
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Na Li
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Qi-Fa Li
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Quan-Hong Ma
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Jie Zhao
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Shao Li
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
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Smedfors G, Olson L, Karlsson TE. A Nogo-Like Signaling Perspective from Birth to Adulthood and in Old Age: Brain Expression Patterns of Ligands, Receptors and Modulators. Front Mol Neurosci 2018. [PMID: 29520216 PMCID: PMC5827527 DOI: 10.3389/fnmol.2018.00042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
An appropriate strength of Nogo-like signaling is important to maintain synaptic homeostasis in the CNS. Disturbances have been associated with schizophrenia, MS and other diseases. Blocking Nogo-like signaling may improve recovery after spinal cord injury, stroke and traumatic brain injury. To understand the interacting roles of an increasing number of ligands, receptors and modulators engaged in Nogo-like signaling, the transcriptional activity of these genes in the same brain areas from birth to old age in the normal brain is needed. Thus, we have quantitatively mapped the innate expression of 11 important genes engaged in Nogo-like signaling. Using in situ hybridization, we located and measured the amount of mRNA encoding Nogo-A, OMgp, NgR1, NgR2, NgR3, Lingo-1, Troy, Olfactomedin, LgI1, ADAM22, and MAG, in 18 different brain areas at six different ages (P0, 1, 2, 4, 14, and 104 weeks). We show gene- and area-specific activities and how the genes undergo dynamic regulation during postnatal development and become stable during adulthood. Hippocampal areas underwent the largest changes over time. We only found differences between individual cortical areas in Troy and MAG. Subcortical areas presented the largest inter-regional differences; lateral and basolateral amygdala had markedly higher expression than other subcortical areas. The widespread differences and unique expression patterns of the different genes involved in Nogo-like signaling suggest that the functional complexes could look vastly different in different areas.
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Affiliation(s)
| | - Lars Olson
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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12
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Zhao Y, Sivaji S, Chiang MC, Ali H, Zukowski M, Ali S, Kennedy B, Sklyar A, Cheng A, Guo Z, Reed AK, Kodali R, Borowski J, Frost G, Beukema P, Wills ZP. Amyloid Beta Peptides Block New Synapse Assembly by Nogo Receptor-Mediated Inhibition of T-Type Calcium Channels. Neuron 2017; 96:355-372.e6. [PMID: 29024660 DOI: 10.1016/j.neuron.2017.09.041] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 07/27/2017] [Accepted: 09/22/2017] [Indexed: 01/07/2023]
Abstract
Compelling evidence links amyloid beta (Aβ) peptide accumulation in the brains of Alzheimer's disease (AD) patients with the emergence of learning and memory deficits, yet a clear understanding of the events that drive this synaptic pathology are lacking. We present evidence that neurons exposed to Aβ are unable to form new synapses, resulting in learning deficits in vivo. We demonstrate the Nogo receptor family (NgR1-3) acts as Aβ receptors mediating an inhibition of synapse assembly, plasticity, and learning. Live imaging studies reveal Aβ activates NgRs on the dendritic shaft of neurons, triggering an inhibition of calcium signaling. We define T-type calcium channels as a target of Aβ-NgR signaling, mediating Aβ's inhibitory effects on calcium, synapse assembly, plasticity, and learning. These studies highlight deficits in new synapse assembly as a potential initiator of cognitive pathology in AD, and pinpoint calcium dysregulation mediated by NgRs and T-type channels as key components. VIDEO ABSTRACT.
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Affiliation(s)
- Yanjun Zhao
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Sivaprakash Sivaji
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Michael C Chiang
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Haadi Ali
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Monica Zukowski
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Sareen Ali
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Bryan Kennedy
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Alex Sklyar
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Alice Cheng
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Zihan Guo
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Alexander K Reed
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Ravindra Kodali
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jennifer Borowski
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Georgia Frost
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Patrick Beukema
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Zachary P Wills
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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13
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Andrew RJ, Kellett KAB, Thinakaran G, Hooper NM. A Greek Tragedy: The Growing Complexity of Alzheimer Amyloid Precursor Protein Proteolysis. J Biol Chem 2016; 291:19235-44. [PMID: 27474742 DOI: 10.1074/jbc.r116.746032] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Proteolysis of the amyloid precursor protein (APP) liberates various fragments including the proposed initiator of Alzheimer disease-associated dysfunctions, amyloid-β. However, recent evidence suggests that the accepted view of APP proteolysis by the canonical α-, β-, and γ-secretases is simplistic, with the discovery of a number of novel APP secretases (including δ- and η-secretases, alternative β-secretases) and additional metabolites, some of which may also cause synaptic dysfunction. Furthermore, various proteins have been identified that interact with APP and modulate its cleavage by the secretases. Here, we give an overview of the increasingly complex picture of APP proteolysis.
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Affiliation(s)
- Robert J Andrew
- From the Departments of Neurobiology, Neurology, and Pathology, The University of Chicago, Chicago, Illinois 60637 and
| | - Katherine A B Kellett
- the Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Gopal Thinakaran
- From the Departments of Neurobiology, Neurology, and Pathology, The University of Chicago, Chicago, Illinois 60637 and
| | - Nigel M Hooper
- the Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
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14
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Alzheimer disease: modeling an Aβ-centered biological network. Mol Psychiatry 2016; 21:861-71. [PMID: 27021818 DOI: 10.1038/mp.2016.38] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/16/2016] [Accepted: 02/18/2016] [Indexed: 01/15/2023]
Abstract
In genetically complex diseases, the search for missing heritability is focusing on rare variants with large effect. Thanks to next generation sequencing technologies, genome-wide characterization of these variants is now feasible in every individual. However, a lesson from current studies is that collapsing rare variants at the gene level is often insufficient to obtain a statistically significant signal in case-control studies, and that network-based analyses are an attractive complement to classical approaches. In Alzheimer disease (AD), according to the prevalent amyloid cascade hypothesis, the pathology is driven by the amyloid beta (Aβ) peptide. In past years, based on experimental studies, several hundreds of proteins have been shown to interfere with Aβ production, clearance, aggregation or toxicity. Thanks to a manual curation of the literature, we identified 335 genes/proteins involved in this biological network and classified them according to their cellular function. The complete list of genes, or its subcomponents, will be of interest in ongoing AD genetic studies.
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15
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Fang Y, Yao L, Li C, Wang J, Wang J, Chen S, Zhou XF, Liao H. The blockage of the Nogo/NgR signal pathway in microglia alleviates the formation of Aβ plaques and tau phosphorylation in APP/PS1 transgenic mice. J Neuroinflammation 2016; 13:56. [PMID: 26939570 PMCID: PMC4776389 DOI: 10.1186/s12974-016-0522-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/24/2016] [Indexed: 12/31/2022] Open
Abstract
Background Alzheimer’s disease (AD) is characterized by extracellular β-amyloid (Aβ) plaques, neurofibrillary tangles (NFTs), and microglia-dominated neuroinflammation. The Nogo/NgR signal pathway is involved in AD pathological features, but the detailed mechanism needs further investigation. Our previous studies have confirmed that the activation of NgR on microglia by Nogo promotes the expression of proinflammatory cytokines and inhibits cell adhesion and migration behaviors. In the present study, we investigated the effects of Nogo/NgR signaling pathway on the pathological features of AD and possible mechanisms. Methods After NEP1-40 (a competitive antagonist of Nogo/NgR pathway) was intracerebroventricularly administered via mini-osmotic pumps for 2 months in amyloid precursor protein (APP)/PS1 transgenic mice, plaque load, tau phosphorylation, and inflammatory responses were determined. After primary mouse neurons were exposed to the conditioned medium from BV-2 microglia stimulated by Nogo, the production of Aβ and phosphorylation of tau was quantified by ELISA and western blot. Results Inhibition of the Nogo/NgR signaling pathway ameliorated pathological features including amyloid plaques and phosphorylated levels of tau in APP/PS1 mice. In addition, after treatment with the conditioned medium from BV-2 microglia stimulated by Nogo, Aβ production and tau phosphorylation in cultured neurons were increased. The conditioned medium also increased the expression of APP, its amyloidogenic processing, and the activity of GSK3β in neurons. The conditioned medium was also proinflammatory medium, and the blockage of the Nogo/NgR pathway improved the neuroinflammatory environment in APP/PS1 mice. Conclusions Taken together, the neuroinflammation mediated by Nogo/NgR pathway in microglia could directly take part in the pathological process of AD by influencing the amyloidogenesis and tau phosphorylation. These results contribute to a better understanding of AD pathogenesis and could offer a new therapeutic option for delaying the progression of AD. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0522-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yinquan Fang
- Jiangsu Key laboratory of Drug Screening, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing, 210009, China.
| | - Lemeng Yao
- Jiangsu Key laboratory of Drug Screening, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing, 210009, China.
| | - Chenhui Li
- Jiangsu Key laboratory of Drug Screening, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing, 210009, China.
| | - Jing Wang
- Jiangsu Key laboratory of Drug Screening, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing, 210009, China.
| | - Jianing Wang
- Jiangsu Key laboratory of Drug Screening, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing, 210009, China.
| | - Shujian Chen
- Jiangsu Key laboratory of Drug Screening, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing, 210009, China.
| | - Xin-Fu Zhou
- School of Pharmacology and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia.
| | - Hong Liao
- Jiangsu Key laboratory of Drug Screening, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing, 210009, China.
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16
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APP Receptor? To Be or Not To Be. Trends Pharmacol Sci 2016; 37:390-411. [PMID: 26837733 DOI: 10.1016/j.tips.2016.01.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/07/2016] [Accepted: 01/11/2016] [Indexed: 11/22/2022]
Abstract
Amyloid precursor protein (APP) and its metabolites play a key role in Alzheimer's disease pathogenesis. The idea that APP may function as a receptor has gained momentum based on its structural similarities to type I transmembrane receptors and the identification of putative APP ligands. We review the recent experimental evidence in support of this notion and discuss how this concept is viewed in the field. Specifically, we focus on the structural and functional characteristics of APP as a cell surface receptor, and on its interaction with adaptors and signaling proteins. We also address the importance of APP function as a receptor in Alzheimer's disease etiology and discuss how this function might be potentially important for the development of novel therapeutic approaches.
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17
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Eckharter C, Junker N, Winter L, Fischer I, Fogli B, Kistner S, Pfaller K, Zheng B, Wiche G, Klimaschewski L, Schweigreiter R. Schwann Cell Expressed Nogo-B Modulates Axonal Branching of Adult Sensory Neurons Through the Nogo-B Receptor NgBR. Front Cell Neurosci 2015; 9:454. [PMID: 26635533 PMCID: PMC4655273 DOI: 10.3389/fncel.2015.00454] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/05/2015] [Indexed: 11/13/2022] Open
Abstract
In contrast to the central nervous system (CNS) nerve fibers do regenerate in the peripheral nervous system (PNS) although in a clinically unsatisfying manner. A major problem is excessive sprouting of regenerating axons which results in aberrant reinnervation of target tissue and impaired functional recovery. In the CNS, the reticulon protein Nogo-A has been identified as a prominent oligodendrocyte expressed inhibitor of long-distance growth of regenerating axons. We show here that the related isoform Nogo-B is abundantly expressed in Schwann cells in the PNS. Other than Nogo-A in oligodendrocytes, Nogo-B does not localize to the myelin sheath but is detected in the ER and the plasma membrane of Schwann cells. Adult sensory neurons that are cultured on nogo-a/b deficient Schwann cells form significantly fewer axonal branches vs. those on wildtype Schwann cells, while their maximal axonal extension is unaffected. We demonstrate that this effect of Nogo-B on neuronal morphology is restricted to undifferentiated Schwann cells and is mediated by direct physical contact between these two cell types. Moreover, we show that blocking the Nogo-B specific receptor NgBR, which we find expressed on sensory neurons and to interact with Schwann cell expressed Nogo-B, produces the same branching phenotype as observed after deletion of Nogo-B. These data provide evidence for a novel function of the nogo gene that is implemented by the Nogo-B isoform. The remarkably specific effects of Nogo-B/NgBR on axonal branching, while leaving axonal extension unaffected, are of potential clinical relevance in the context of excessive axonal sprouting after peripheral nerve injury.
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Affiliation(s)
- Christoph Eckharter
- Division of Neurobiochemistry, Biocenter, Innsbruck Medical University Innsbruck, Austria
| | - Nina Junker
- Division of Neurobiochemistry, Biocenter, Innsbruck Medical University Innsbruck, Austria
| | - Lilli Winter
- Max F. Perutz Laboratories, Department of Biochemistry and Cell Biology, University of Vienna Vienna, Austria
| | - Irmgard Fischer
- Max F. Perutz Laboratories, Department of Biochemistry and Cell Biology, University of Vienna Vienna, Austria
| | - Barbara Fogli
- Department of Anatomy, Histology and Embryology, Division of Neuroanatomy, Innsbruck Medical University Innsbruck, Austria
| | - Steffen Kistner
- Division of Neurobiochemistry, Biocenter, Innsbruck Medical University Innsbruck, Austria
| | - Kristian Pfaller
- Department of Anatomy, Histology and Embryology, Division of Histology and Embryology, Innsbruck Medical University Innsbruck, Austria
| | - Binhai Zheng
- Department of Neurosciences and Biomedical Sciences Graduate Program, School of Medicine, University of California, San Diego La Jolla, CA, USA
| | - Gerhard Wiche
- Max F. Perutz Laboratories, Department of Biochemistry and Cell Biology, University of Vienna Vienna, Austria
| | - Lars Klimaschewski
- Department of Anatomy, Histology and Embryology, Division of Neuroanatomy, Innsbruck Medical University Innsbruck, Austria
| | - Rüdiger Schweigreiter
- Division of Neurobiochemistry, Biocenter, Innsbruck Medical University Innsbruck, Austria
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18
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Sui YP, Zhang XX, Lu JL, Sui F. New Insights into the Roles of Nogo-A in CNS Biology and Diseases. Neurochem Res 2015; 40:1767-85. [PMID: 26266872 DOI: 10.1007/s11064-015-1671-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/15/2015] [Accepted: 07/17/2015] [Indexed: 12/22/2022]
Abstract
Nogos have become a hot topic for its well-known number Nogo-A's big role in clinical matters. It has been recognized that the expression of Nogo-A and the receptor NgR1 inhibit the neuron's growth after CNS injuries or the onset of the MS. The piling evidence supports the notion that the Nogo-A is also involved in the synaptic plasticity, which was shown to negatively regulate the strength of synaptic transmission. The occurrence of significant schizophrenia-like behavioral phenotypes in Nogo-A KO rats also added strong proof to this conclusion. This review mainly focuses on the structure of Nogo-A and its corresponding receptor-NgR1, its intra- and extra-cellular signaling, together with its major physiological functions such as regulation of migration and distribution and its related diseases like stroke, AD, ALS and so on.
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Affiliation(s)
- Yun-Peng Sui
- Institute of Chinese Material Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
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19
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Gautam V, D'Avanzo C, Berezovska O, Tanzi RE, Kovacs DM. Synaptotagmins interact with APP and promote Aβ generation. Mol Neurodegener 2015. [PMID: 26202512 PMCID: PMC4511450 DOI: 10.1186/s13024-015-0028-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Background Accumulation of the β-amyloid peptide (Aβ) is a major pathological hallmark of Alzheimer’s disease (AD). Recent studies have shown that synaptic Aβ toxicity may directly impair synaptic function. However, proteins regulating Aβ generation at the synapse have not been characterized. Here, we sought to identify synaptic proteins that interact with the extracellular domain of APP and regulate Aβ generation. Results Affinity purification-coupled mass spectrometry identified members of the Synaptotagmin (Syt) family as novel interacting proteins with the APP ectodomain in mouse brains. Syt-1, −2 and −9 interacted with APP in cells and in mouse brains in vivo. Using a GST pull-down approach, we have further demonstrated that the Syt interaction site lies in the 108 amino acids linker region between the E1 and KPI domains of APP. Stable overexpression of Syt-1 or Syt-9 with APP in CHO and rat pheochromocytoma cells (PC12) significantly increased APP-CTF and sAPP levels, with a 2 to 3 fold increase in secreted Aβ levels in PC12 cells. Moreover, using a stable knockdown approach to reduce the expression of endogenous Syt-1 in PC12 cells, we have observed a ~ 50 % reduction in secreted Aβ generation. APP processing also decreased in these cells, shown by lower CTF levels. Lentiviral-mediated knock down of endogenous Syt-1 in mouse primary neurons also led to a significant reduction in both Aβ40 and Aβ42 generation. As secreted sAPPβ levels were significantly reduced in PC12 cells lacking Syt-1 expression, our results suggest that Syt-1 regulates Aβ generation by modulating BACE1-mediated cleavage of APP. Conclusion Altogether, our data identify the synaptic vesicle proteins Syt-1 and 9 as novel APP-interacting proteins that promote Aβ generation and thus may play an important role in the pathogenesis of AD. Electronic supplementary material The online version of this article (doi:10.1186/s13024-015-0028-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vivek Gautam
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Carla D'Avanzo
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Oksana Berezovska
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Dora M Kovacs
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
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20
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Dai X, Sun Z, Liang R, Li Y, Luo H, Huang Y, Chen M, Su Z, Xiao F. Recombinant Nogo-66 via soluble expression with SUMO fusion in Escherichia coli inhibits neurite outgrowth in vitro. Appl Microbiol Biotechnol 2015; 99:5997-6007. [PMID: 25758955 DOI: 10.1007/s00253-015-6477-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 11/28/2022]
Abstract
Nogo-66, a hydrophilic loop of 66 amino acids flank two hydrophobic domains of the Nogo-A C terminus, interacts with the Nogo-66 receptor (NgR) to exert numerous functions in the central nervous system (CNS). Nogo-66 has important roles in aspects of neuronal development, including cell migration, axon guidance, fasciculation, and dendritic branching, and in aspects of CNS plasticity, including oligodendrocyte differentiation and myelination. Here, the small ubiquitin-related modifier (SUMO) was fused to the target gene, Nogo-66, and the construct was expressed in Escherichia coli (E. coli). Under the optimal fermentation conditions, the soluble expression level of the fusion protein was 33 % of the total supernatant protein. After cleaving the fusion proteins with SUMO protease and purifying them by Ni-NTA affinity chromatography, the yield and purity of recombinant Nogo-66 obtained by 10-L scale fermentation were 23 ± 1.5 mg/L and greater than 93 %, respectively. The authenticity of the recombinant Nogo-66 was confirmed by an electrospray ionization-mass spectrometry analysis. The functional analyses indicated that the recombinant Nogo-66 was capable of binding the NgR specifically. The immunofluorescence results showed that the recombinant Nogo-66 could significantly inhibit neurite outgrowth of rat pheochromocytoma (PC12) cells stimulated by nerve growth factor and cerebellar granule cells (CGCs). Furthermore, Nogo-66 inhibited neurite outgrowth by increasing the level of phosphorylated Rho-associated coiled-coil-containing protein kinase 2 (ROCK2), collapsin response mediator protein 2 (CRMP2), and myosin light chain (MLC). This study provided a feasible and convenient production method for generating sufficient recombinant Nogo-66 for experimental and clinical applications.
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Affiliation(s)
- Xiaoyong Dai
- Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou, 510632, People's Republic of China
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21
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Xu YQ, Sun ZQ, Wang YT, Xiao F, Chen MW. Function of Nogo-A/Nogo-A receptor in Alzheimer's disease. CNS Neurosci Ther 2015; 21:479-85. [PMID: 25732725 DOI: 10.1111/cns.12387] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/01/2015] [Accepted: 01/02/2015] [Indexed: 12/11/2022] Open
Abstract
Nogo-A is a protein inhibiting axonal regeneration, which is considered a major obstacle to nerve regeneration after injury in mammals. Rapid progress has been achieved in new physiopathological function of Nogo-A in Alzheimer's disease in the past decade. Recent research shows that through binding to Nogo-A receptor, Nogo-A plays an important role in Alzheimer's disease (AD) pathogenesis. Particularly, Nogo-A/Nogo-A receptors modulate the generation of amyloid β-protein (Aβ), which is thought to be a major cause of AD. This review describes the recent development of Nogo-A, Nogo-A receptor, and downstream signaling involved in AD and pharmacological basis of therapeutic drugs. We concluded the Nogo-A/Nogo-A receptor provide new insight into potential mechanisms and promising therapy strategies in AD.
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Affiliation(s)
- Ying-Qi Xu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Zhong-Qing Sun
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, China
| | - Yi-Tao Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Fei Xiao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.,Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, China
| | - Mei-Wan Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
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22
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Fujita Y, Yamashita T. Axon growth inhibition by RhoA/ROCK in the central nervous system. Front Neurosci 2014; 8:338. [PMID: 25374504 PMCID: PMC4205828 DOI: 10.3389/fnins.2014.00338] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 10/06/2014] [Indexed: 12/31/2022] Open
Abstract
Rho kinase (ROCK) is a serine/threonine kinase and a downstream target of the small GTPase Rho. The RhoA/ROCK pathway is associated with various neuronal functions such as migration, dendrite development, and axonal extension. Evidence from animal studies reveals that RhoA/ROCK signaling is involved in various central nervous system (CNS) diseases, including optic nerve and spinal cord injuries, stroke, and neurodegenerative diseases. Given that RhoA/ROCK plays a critical role in the pathophysiology of CNS diseases, the development of therapeutic agents targeting this pathway is expected to contribute to the treatment of CNS diseases. The RhoA/ROCK pathway mediates the effects of myelin-associated axon growth inhibitors—Nogo, myelin-associated glycoprotein (MAG), oligodendrocyte-myelin glycoprotein (OMgp), and repulsive guidance molecule (RGM). Blocking RhoA/ROCK signaling can reverse the inhibitory effects of these molecules on axon outgrowth, and promotes axonal sprouting and functional recovery in animal models of CNS injury. To date, several RhoA/ROCK inhibitors have been under development or in clinical trials as therapeutic agents for neurological disorders. In this review, we focus on the RhoA/ROCK signaling pathway in neurological disorders. We also discuss the potential therapeutic approaches of RhoA/ROCK inhibitors for various neurological disorders.
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Affiliation(s)
- Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University Osaka, Japan ; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology Tokyo, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University Osaka, Japan ; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology Tokyo, Japan
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23
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Borrie SC, Sartori SB, Lehmann J, Sah A, Singewald N, Bandtlow CE. Loss of Nogo receptor homolog NgR2 alters spine morphology of CA1 neurons and emotionality in adult mice. Front Behav Neurosci 2014; 8:175. [PMID: 24860456 PMCID: PMC4030173 DOI: 10.3389/fnbeh.2014.00175] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 04/25/2014] [Indexed: 01/08/2023] Open
Abstract
Molecular mechanisms which stabilize dendrites and dendritic spines are essential for regulation of neuronal plasticity in development and adulthood. The class of Nogo receptor proteins, which are critical for restricting neurite outgrowth inhibition signaling, have been shown to have roles in developmental, experience and activity induced plasticity. Here we investigated the role of the Nogo receptor homolog NgR2 in structural plasticity in a transgenic null mutant for NgR2. Using Golgi-Cox staining to analyze morphology, we show that loss of NgR2 alters spine morphology in adult CA1 pyramidal neurons of the hippocampus, significantly increasing mushroom-type spines, without altering dendritic tree complexity. Furthermore, this shift is specific to apical dendrites in distal CA1 stratum radiatum (SR). Behavioral alterations in NgR2(-/-) mice were investigated using a battery of standardized tests and showed that whilst there were no alterations in learning and memory in NgR2(-/-) mice compared to littermate controls, NgR2(-/-) displayed reduced fear expression in the contextual conditioned fear test, and exhibited reduced anxiety- and depression-related behaviors. This suggests that the loss of NgR2 results in a specific phenotype of reduced emotionality. We conclude that NgR2 has role in maintenance of mature spines and may also regulate fear and anxiety-like behaviors.
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Affiliation(s)
- Sarah C Borrie
- Division of Neurobiochemistry, Biocenter, Innsbruck Medical University Innsbruck, Austria
| | - Simone B Sartori
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Centre for Molecular Biosciences Innsbruck, University of Innsbruck Innsbruck, Austria
| | - Julian Lehmann
- Division of Neurobiochemistry, Biocenter, Innsbruck Medical University Innsbruck, Austria
| | - Anupam Sah
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Centre for Molecular Biosciences Innsbruck, University of Innsbruck Innsbruck, Austria
| | - Nicolas Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Centre for Molecular Biosciences Innsbruck, University of Innsbruck Innsbruck, Austria
| | - Christine E Bandtlow
- Division of Neurobiochemistry, Biocenter, Innsbruck Medical University Innsbruck, Austria
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24
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Jiang S, Li Y, Zhang X, Bu G, Xu H, Zhang YW. Trafficking regulation of proteins in Alzheimer's disease. Mol Neurodegener 2014; 9:6. [PMID: 24410826 PMCID: PMC3891995 DOI: 10.1186/1750-1326-9-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 12/15/2013] [Indexed: 12/12/2022] Open
Abstract
The β-amyloid (Aβ) peptide has been postulated to be a key determinant in the pathogenesis of Alzheimer’s disease (AD). Aβ is produced through sequential cleavage of the β-amyloid precursor protein (APP) by β- and γ-secretases. APP and relevant secretases are transmembrane proteins and traffic through the secretory pathway in a highly regulated fashion. Perturbation of their intracellular trafficking may affect dynamic interactions among these proteins, thus altering Aβ generation and accelerating disease pathogenesis. Herein, we review recent progress elucidating the regulation of intracellular trafficking of these essential protein components in AD.
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Affiliation(s)
| | | | | | | | | | - Yun-wu Zhang
- Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China.
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Cacabelos R, Cacabelos P, Torrellas C, Tellado I, Carril JC. Pharmacogenomics of Alzheimer's disease: novel therapeutic strategies for drug development. Methods Mol Biol 2014; 1175:323-556. [PMID: 25150875 DOI: 10.1007/978-1-4939-0956-8_13] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is a major problem of health and disability, with a relevant economic impact on our society. Despite important advances in pathogenesis, diagnosis, and treatment, its primary causes still remain elusive, accurate biomarkers are not well characterized, and the available pharmacological treatments are not cost-effective. As a complex disorder, AD is a polygenic and multifactorial clinical entity in which hundreds of defective genes distributed across the human genome may contribute to its pathogenesis. Diverse environmental factors, cerebrovascular dysfunction, and epigenetic phenomena, together with structural and functional genomic dysfunctions, lead to amyloid deposition, neurofibrillary tangle formation, and premature neuronal death, the major neuropathological hallmarks of AD. Future perspectives for the global management of AD predict that genomics and proteomics may help in the search for reliable biomarkers. In practical terms, the therapeutic response to conventional drugs (cholinesterase inhibitors, multifactorial strategies) is genotype-specific. Genomic factors potentially involved in AD pharmacogenomics include at least five categories of gene clusters: (1) genes associated with disease pathogenesis; (2) genes associated with the mechanism of action of drugs; (3) genes associated with drug metabolism (phase I and II reactions); (4) genes associated with drug transporters; and (5) pleiotropic genes involved in multifaceted cascades and metabolic reactions. The implementation of pharmacogenomic strategies will contribute to optimize drug development and therapeutics in AD and related disorders.
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Affiliation(s)
- Ramón Cacabelos
- Chair of Genomic Medicine, Camilo José Cela University, 28692, Villanueva de la Cañada, Madrid, Spain,
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Nordgren M, Karlsson T, Svensson M, Koczy J, Josephson A, Olson L, Tingström A, Brené S. Orchestrated regulation of Nogo receptors, LOTUS, AMPA receptors and BDNF in an ECT model suggests opening and closure of a window of synaptic plasticity. PLoS One 2013; 8:e78778. [PMID: 24244357 PMCID: PMC3828303 DOI: 10.1371/journal.pone.0078778] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/18/2013] [Indexed: 01/16/2023] Open
Abstract
Electroconvulsive therapy (ECT) is an efficient and relatively fast acting treatment for depression. However, one severe side effect of the treatment is retrograde amnesia, which in certain cases can be long-term. The mechanisms behind the antidepressant effect and the amnesia are not well understood. We hypothesized that ECT causes transient downregulation of key molecules needed to stabilize synaptic structure and to prevent Ca2+ influx, and a simultaneous increase in neurotrophic factors, thus providing a short time window of increased structural synaptic plasticity. Here we followed regulation of NgR1, NgR3, LOTUS, BDNF, and AMPA subunits GluR1 and GluR2 flip and flop mRNA levels in hippocampus at 2, 4, 12, 24, and 72 hours after a single episode of induced electroconvulsive seizures (ECS) in rats. NgR1 and LOTUS mRNA levels were transiently downregulated in the dentate gyrus 2, 4, 12 and 4, 12, 24 h after ECS treatment, respectively. GluR2 flip, flop and GluR1 flop were downregulated at 4 h. GluR2 flip remained downregulated at 12 h. In contrast, BDNF, NgR3 and GluR1 flip mRNA levels were upregulated. Thus, ECS treatment induces a transient regulation of factors important for neuronal plasticity. Our data provide correlations between ECS treatment and molecular events compatible with the hypothesis that both effects and side effects of ECT may be caused by structural synaptic rearrangements.
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Affiliation(s)
- Max Nordgren
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Tobias Karlsson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Maria Svensson
- Psychiatric Neuromodulation Unit, Wallenberg Neuroscience Center, University Hospital, Lund, Sweden
| | - Josefin Koczy
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Anna Josephson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Lars Olson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Anders Tingström
- Psychiatric Neuromodulation Unit, Wallenberg Neuroscience Center, University Hospital, Lund, Sweden
| | - Stefan Brené
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
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Mironova YA, Giger RJ. Where no synapses go: gatekeepers of circuit remodeling and synaptic strength. Trends Neurosci 2013; 36:363-73. [PMID: 23642707 DOI: 10.1016/j.tins.2013.04.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/01/2013] [Accepted: 04/01/2013] [Indexed: 02/07/2023]
Abstract
Growth inhibitory molecules in the adult mammalian central nervous system (CNS) have been implicated in the blocking of axonal sprouting and regeneration following injury. Prominent CNS regeneration inhibitors include Nogo-A, oligodendrocyte myelin glycoprotein (OMgp), and chondroitin sulfate proteoglycans (CSPGs), and a key question concerns their physiological role in the naïve CNS. Emerging evidence suggests novel functions in dendrites and at synapses of glutamatergic neurons. CNS regeneration inhibitors target the neuronal actin cytoskeleton to regulate dendritic spine maturation, long-term synapse stability, and Hebbian forms of synaptic plasticity. This is accomplished in part by antagonizing plasticity-promoting signaling pathways activated by neurotrophic factors. Altered function of CNS regeneration inhibitors is associated with mental illness and loss of long-lasting memory, suggesting unexpected and novel physiological roles for these molecules in brain health.
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Affiliation(s)
- Yevgeniya A Mironova
- Department of Cell and Developmental Biology, University of Michigan School of Medicine, 3065 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA
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The Nogo-66 receptor family in the intact and diseased CNS. Cell Tissue Res 2012; 349:105-17. [PMID: 22311207 DOI: 10.1007/s00441-012-1332-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 01/16/2012] [Indexed: 10/14/2022]
Abstract
The Nogo-66 receptor family (NgR) consists in three glycophosphatidylinositol (GPI)-anchored receptors (NgR1, NgR2 and NgR3), which are primarily expressed by neurons in the central and peripheral mammalian nervous system. NgR1 was identified as serving as a high affinity binding protein for the three classical myelin-associated inhibitors (MAIs) Nogo-A, myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMgp), which limit axon regeneration and sprouting in the injured brain. Recent studies suggest that NgR signaling may also play an essential role in the intact adult CNS in restricting axonal and synaptic plasticity and are involved in neurodegenerative diseases, particularly in Alzheimer's disease pathology through modulation of β-secretase cleavage. Here, we outline the biochemical properties of NgRs and their functional roles in the intact and diseased CNS.
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Kern F, Sarg B, Stasyk T, Hess D, Lindner H. The Nogo receptor 2 is a novel substrate of Fbs1. Biochem Biophys Res Commun 2012; 417:977-81. [PMID: 22206664 PMCID: PMC3269754 DOI: 10.1016/j.bbrc.2011.12.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 12/13/2011] [Indexed: 11/15/2022]
Abstract
Members of the Nogo66 receptor family (NgR) are closely associated with nerve growth inhibition and plasticity in the CNS. All three members, NgR1, NgR2 and NgR3, are GPI anchored and highly glycosylated proteins. The binding and signaling properties of NgR1 are well described, but largely unknown for NgR2. At present the only known ligands are myelin associated glycoprotein (MAG) and amyloid beta precursor protein (APP). Despite the requirement of co-receptors for signaling no other binding partner has been uncovered. To learn more about the interactome of NgR2 we performed pull down experiments and were able to identify F-box protein that recognizes sugar chain 1 (Fbs1) as binding partner. We confirmed this finding with co-immunoprecipitations and in vitro binding assays and showed that the binding is mediated by the substrate recognition domain of Fbs1. As a substrate recognition protein of the SCF complex, Fbs1 binding leads to polyubiquitination and finally degradation of its substrates. This is the first time a member of the Nogo receptor family has been connected with an intracellular degradation pathway, which has not only implications for its production, but also for amyloid deposition in Alzheimer’s disease.
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Affiliation(s)
- Florian Kern
- Neurobiochemistry - Biocenter, Innsbruck Medical University, Austria.
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