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Bai Q, Sun D, Zeng Y, Zhu J, Zhang C, Zhang X, Chen L, Zhou X, Ye L, Tang Y, Liu Y, Morozova-Roche LA. Effect of Proinflammatory S100A9 Protein on Migration and Proliferation of Microglial Cells. J Mol Neurosci 2023; 73:983-995. [PMID: 37947991 DOI: 10.1007/s12031-023-02168-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023]
Abstract
Alzheimer's disease (AD) is a multifactorial disease affecting aging population worldwide. Neuroinflammation became a focus of research as one of the major pathologic processes relating to the disease onset and progression. Proinflammatory S100A9 is the central culprit in the amyloid-neuroinflammatory cascade implicated in AD and other neurodegenerative diseases. We studied the effect of S100A9 on microglial BV-2 cell proliferation and migration. The responses of BV-2 cells to S100A9 stimulation were monitored in real-time using live cell microscopy, transcriptome sequencing, immunofluorescence staining, western blot analysis, and ELISA. We observed that a low dose of S100A9 promotes migration and proliferation of BV-2 cells. However, acute inflammatory condition (i.e., high S100A9 doses) causes diminished cell viability; it is uncovered that S100A9 activates TLR-4 and TLR-7 signaling pathways, leading to TNF-α and IL-6 expression, which affect BV-2 cell migration and proliferation in a concentration-dependent manner. Interestingly, the effects of S100A9 are not only inhibited by TNF-α and IL-6 antibodies. The addition of amyloid-β (Aβ) 1-40 peptide resumes the capacities of BV-2 cells to the level of low S100A9 concentrations. Based on these results, we conclude that in contrast to the beneficial effects of low S100A9 dose, high S100A9 concentration leads to impaired mobility and proliferation of immune cells, reflecting neurotoxicity at acute inflammatory conditions. However, the formation of Aβ plaques may be a natural mechanism that rescues cells from the proinflammatory and cytotoxic effects of S100A9, especially considering that inflammation is one of the primary causes of AD.
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Affiliation(s)
- Qiao Bai
- Chongqing Medical University, 1 Medical College Road, Yu Zhong District, Chongqing, China
| | - Dan Sun
- State Key Laboratory of Photon-Technology in Western China Energy, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, Shaanxi, China
| | - Yang Zeng
- State Key Laboratory of Photon-Technology in Western China Energy, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, Shaanxi, China
| | - Jie Zhu
- State Key Laboratory of Photon-Technology in Western China Energy, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, Shaanxi, China
| | - Ce Zhang
- State Key Laboratory of Photon-Technology in Western China Energy, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, Shaanxi, China
| | - Xiaoyin Zhang
- Chongqing Medical University, 1 Medical College Road, Yu Zhong District, Chongqing, China
| | - Li Chen
- Chongqing Medical University, 1 Medical College Road, Yu Zhong District, Chongqing, China
| | - Xin Zhou
- Chongqing Medical University, 1 Medical College Road, Yu Zhong District, Chongqing, China
| | - Liu Ye
- Chongqing Medical University, 1 Medical College Road, Yu Zhong District, Chongqing, China
| | - Yong Tang
- Chongqing Medical University, 1 Medical College Road, Yu Zhong District, Chongqing, China
| | - Yonggang Liu
- Chongqing Medical University, 1 Medical College Road, Yu Zhong District, Chongqing, China.
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Huang Y, Wang T, Chen Y, Lin H, Chen D. Amyloid hexapeptide prevent dental caries by antibiofilm formation. J Dent 2023; 135:104596. [PMID: 37353107 DOI: 10.1016/j.jdent.2023.104596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 06/25/2023] Open
Abstract
OBJECTIVES Biofilm formed by cariogenic microbes is the direct cause of dental caries, therefore, prevention of dental caries should be anti-biofilm-based. Previously, we found the amyloid hexapeptides efficiently inhibited biofilm formation by aggregating into amyloid fibrils agglutinating microbes. This study aimed to select the most stable amyloid hexapeptide GIDLKI (GI6) and study its anti-caries effect. METHODS Biofilms of multi-species bacteria, derived from mixed saliva, were cultured to evaluate the anti-biofilm formation effect of GI6. And then, the primary cariogenic bacterium Streptococcus mutans (S.mutans) was cultured in BHI with various pH, gradient concentrations of sucrose, glucose, and calcium ions to evaluate the anti-biofilm formation effects of GI6. Then models of human enamel block caries and twenty male SPF-SD rat caries induced by S. mutans biofilm were constructed, and confocal laser scanning microscopy, scanning electron microscopy, and micro-computed tomography were applied to investigate the anti-biofilm formation, anti-caries effects and use safety of GI6. RESULTS GI6 could inhibit the multi-species bacteria biofilm formation and remained effective in anti-biofilm activity against S. mutans in environments closely related to caries. GI6 suppressed S. mutans biofilm formation and thus prevented or alleviated the development of caries in human tooth blocks and rat teeth. GI6 did not affect the intestinal flora, serum biochemical parameters, and the pathological changes of various organs. CONCLUSIONS Amyloid hexapeptides, including but not limited to GI6, are novel effective anti-caries agents that can be used to prevent dental caries safely. CLINICAL SIGNIFICANCE This study explored the anti-biofilm formation and anti-caries effect of GI6 in vitro, highlighting the anti-biofilm formation therapy for dental caries and setting a foundation for the practical application of GI6 for the treatment of dental caries.
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Affiliation(s)
- Yiyi Huang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China
| | - Tingyu Wang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China
| | - Yucong Chen
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China
| | - Huancai Lin
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China.
| | - Dongru Chen
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China.
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Vezenkov LT, Danalev DL, Iwanov I, Lozanov V, Atanasov A, Todorova R, Vassilev N, Karadjova V. Synthesis and biological study of new galanthamine-peptide derivatives designed for prevention and treatment of Alzheimer 's disease. Amino Acids 2022; 54:897-910. [PMID: 35562605 DOI: 10.1007/s00726-022-03167-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/23/2022] [Indexed: 11/29/2022]
Abstract
The Alzheimer's disease leads to neurodegenerative processes and affecting negatively million people worldwide. The treatment of the disease is still difficult and incomplete in practice. Galanthamine is one of the most commonly used drugs against the illness. The main aim of this work is design and synthesis of new derivatives of galanthamine comprising peptide moiety as well as study of their β-secretase inhibitory activity and the anti-aggregating effect. All new derivatives of galanthamine containing analogues of Leu-Val-Phe-Phe (Aβ17-Aβ20) were synthesized in solution using fragment and consecutive condensation approaches. The new derivatives were characterized by melting points, NMR, and HPLC/MS. They were tested in vitro for β-secretase inhibition activity by means of fluorescent method and were investigated in vitro for anti-aggregation activity on sheep platelet-rich plasma. Although the new compounds do not contain a structural element responsible for the β-secretase inhibition, five of them show high or good β-secretase inhibitory activity between 19.98 and 51.19% with IC50 between 1.95 and 5.26 nM. Four of the new molecules were able to inhibit platelet aggregation between 55.0 and 90.0% with IC50 between 0.69 and 1.36 µM. Four of the compounds were able to inhibit platelet aggregation and two of them have high anti-aggregating effects.
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Affiliation(s)
| | - Dancho L Danalev
- University of Chemical Technology and Metallurgy, Sofia, 1756, Bulgaria.
| | - Iwan Iwanov
- University of Chemical Technology and Metallurgy, Sofia, 1756, Bulgaria
| | - Valentin Lozanov
- Department of Medical Chemistry and Biochemistry, Medical University of Sofia, Sofia, 1000, Bulgaria
| | - Atanas Atanasov
- Medical Faculty, Trakia University, Stara Zagora, 6000, Bulgaria
| | - Rumyana Todorova
- Medical Faculty, Trakia University, Stara Zagora, 6000, Bulgaria
| | - Nikolay Vassilev
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, 1113, Bulgaria
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Wang Y, Xiu X, Wu S. Amyloid peptide exerts a rapid induction of Dicer1 protein in neuron via reducing phosphorylation. Neurochem Int 2021; 151:105210. [PMID: 34695450 DOI: 10.1016/j.neuint.2021.105210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/24/2021] [Accepted: 10/10/2021] [Indexed: 11/21/2022]
Abstract
A growing number of evidence suggests that altered microRNA network in the brain contributes to the risk of Alzheimer's disease(AD). Dicer1 is a type III riboendonuclease which cleaves pre-microRNA into functional microRNA. Reduction of Dicer1 or Dicer1 mutation has been involved in cancer, aging or age-related macular degeneration. Recently, we found a possible link between Dicer1 and AD. In particular, Dicer1 protein and Dicer1 mRNA is reduced in the hippocampus and the cortex of an animal model of AD and exposure to Aβ42 oligomer(AβO) longer than 6 h reduces the transcription of Dicer1 gene in neuron, via depletion of NF-E2-related factor-2. In this study, exposure to AβO at shorter time increased Dicer1 protein in neuron in a dose-dependent mode; but the mRNA level remained unaltered. Under this treatment regime,AβO reduced phosphorylation level of Dicer1 and of its binding partner, transactivation response element RNA-binding protein(TRBP). Addition of a JNK inhibitor,SP600125, or an ERK inhibitor,U0126, further increased Dicer1 protein compared to Aβo treatment alone, with simultaneaous reduction of phospho-Dicer1, but with different effects on phospho-TRBP. Finally, an inhibitor of calcineurin,FK506, further increased Dicer1 protein compared to Aβo treatment alone. Thus, phosphorylation of Dicer1 and TRBP was determined by mitogen activated protein kinases JNK,ERK, and protein phosphatase 2B(calcineurin) which together determined Dicer1 stability. In summary, reduced phosphorylation of Dicer1 accounted for the rapid induction of Dicer1 by AβO. This study highlights a novel way by which AβO regulates Dicer1.
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Saray H, Süer C, Koşar B, Tan B, Dursun N. Rho-associated kinases contribute to the regulation of tau phosphorylation and amyloid metabolism during neuronal plasticity. Pharmacol Rep 2021; 73:1303-1314. [PMID: 34060063 DOI: 10.1007/s43440-021-00279-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 05/04/2021] [Accepted: 05/12/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND Neural plasticity under physiological condition develops together with normal tau phosphorylation and amyloid precursor protein (APP) processing. Since restoration of PI3-kinase signaling has therapeutic potential in Alzheimer's disease, we investigated plasticity-related changes in tau and APP metabolism by the selective Rho-kinase inhibitor fasudil. METHODS Field potentials composed of a field excitatory post-synaptic potential (fEPSP) and a population spike (PS) were recorded from a granule cell layer of the dentate gyrus. Plasticity of synaptic strength and neuronal function was induced by strong tetanic stimulation (HFS) and low-frequency stimulation (LFS) patterns. Infusions of saline or fasudil were given for 1 h starting from the application of the induction protocols. Total and phosphorylated tau levels and soluble APPα levels were measured in the hippocampus, which was removed after at least 1 h post-induction period. RESULTS Fasudil infusion resulted in attenuation of fEPSP slope and PS amplitude in response to both HFS and LFS. Fasudil reduced total tau and phosphorylated tau at residue Thr181 in the HFS-stimulated hippocampus, while Thr231 phosphorylation was reduced by fasudil treatment in the LFS-stimulated hippocampus. Ser416 phosphorylation was increased by fasudil treatment in both HFS- and LFS-stimulated hippocampus. Fasudil significantly increased soluble APPα in LFS-stimulated hippocampus, but not in HFS-stimulated hippocampus. CONCLUSION In light of our findings, we suggest that increased activity of Rho kinase could trigger a mechanism that goes awry during synaptic plasticity which is reversed by a Rho-kinase inhibitor. Thus, Rho-kinase inhibition might be a therapeutic target in cognitive disorders.
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Affiliation(s)
- Hatice Saray
- Physiology Department of the Medical Faculty, Erciyes University, 38039, Kayseri, Turkey
| | - Cem Süer
- Physiology Department of the Medical Faculty, Erciyes University, 38039, Kayseri, Turkey.
| | - Bilal Koşar
- Physiology Department of the Medical Faculty, Erciyes University, 38039, Kayseri, Turkey
| | - Burak Tan
- Physiology Department of the Medical Faculty, Erciyes University, 38039, Kayseri, Turkey
| | - Nurcan Dursun
- Physiology Department of the Medical Faculty, Erciyes University, 38039, Kayseri, Turkey
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Wang Y, Lian M, Xiu X, Zhang Z, Song L, Wu S. Dicer1 promotes Aβ clearance via blocking B2 RNA-mediated repression of apolipoprotein E. Biochim Biophys Acta Mol Basis Dis 2020; 1867:166038. [PMID: 33285223 DOI: 10.1016/j.bbadis.2020.166038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/10/2020] [Accepted: 11/30/2020] [Indexed: 12/30/2022]
Abstract
Metabolism of β-amyloid is critical for healthy brain. Decreased clearance of β-amyloid is associated with ensued accumulation of amyloid peptide, culminating in formation of senile plaques, a neuropathological hallmark of Alzheimer's disease(AD). Apolipoprotein E (APOE), a lipoprotein for phospholipid and cholesterol metabolism, is predominantly synthesized by glia in the central nervous system, controlling Aβ aggregation and metabolism. By use of stereotactic injection and a Morris water maze, we found that delivery of Dicer1-expressing adenovirus into the hippocampus of an animal model of AD mice APPswe/PSEN1deltaE9 significantly improved spatial memory. The effect was associated with reduced amyloid peptides in the hippocampus which were analyzed with immunofluorescence and enzyme-linked immunosorbent assay. With western blot, quantitative real-time PCR, fluorescence in situ hybridization, and northern blot,Dicer1 overexpression increased apolipoprotein E (APOE) and concomitantly decreased B2 RNA in the hippocampus of the AD mice and in astrocyte cultures whereas transfection of B2 Mm2 RNA decreased APOE mRNA and protein levels in astrocyte cultures. Further, human or mouse APOE mRNA was found containing Alu RNA or its equivalent, B2 Mm2 RNA, locating downstream of its 3'-untranslated region (UTR), respectively. The 3'-UTR or 3'-UTR in conjunction with the downstream Alu/B2 RNA were cloned into a luciferase reporter; with dual-luciferase assay, we found that simultaneous transfection of Dicer1 siRNA or Alu/B2 RNA decreased the corresponding luciferase activities which suggest that Alu RNA mediated APOE mRNA degradation. Altogether, Dicer1 expression mediated amyloid peptide clearance by increasing APOE via blocking B2 RNA-mediated APOE mRNA degradation.
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Affiliation(s)
- Yan Wang
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, PR China
| | - Meiling Lian
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, PR China
| | - Xiaoyu Xiu
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, PR China
| | - Zhiwen Zhang
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, PR China
| | - Liping Song
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, PR China
| | - Shengzhou Wu
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, PR China.
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Grasso G, Lionello C, Stojceski F. Highlighting the effect of amyloid beta assemblies on the mechanical properties and conformational stability of cell membrane. J Mol Graph Model 2020; 100:107670. [PMID: 32711259 DOI: 10.1016/j.jmgm.2020.107670] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 01/05/2023]
Abstract
Alzheimer disease (AD) is the most common cause of dementia, characterized by a progressive decline in cognitive function due to the abnormal aggregation and deposition of Amyloid beta (Aβ) fibrils in the brain of patients. In this context, the molecular mechanisms of protein misfolding and aggregation that are known to induce significant biophysical alterations in cells, including destabilization of plasma membranes, remain partially unclear. Physical interaction between the Aβ assemblies and the membrane leads to the disruption of the cell membrane in multiple ways including, surface carpeting, generation of transmembrane channels and detergent-like membrane dissolution. Understanding the impact of amyloidogenic protein in different stages of aggregation with the plasma membrane, plays a crucial role to fully elucidate the pathological mechanisms of AD. Within this framework, computer simulations represent a powerful tool able to shed lights on the interactions governing the structural influence of Aβ proteins on biological membrane. In this study, molecular dynamics (MD) simulations have been performed in order to characterize how POPC bilayer conformational and mechanical properties are affected by the interaction with Aβ11-42 peptide, oligomer and fibril.
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Lessard CB, Rodriguez E, Ladd TB, Minter LM, Osborne BA, Miele L, Golde TE, Ran Y. γ-Secretase modulators exhibit selectivity for modulation of APP cleavage but inverse γ-secretase modulators do not. Alzheimers Res Ther 2020; 12:61. [PMID: 32430033 PMCID: PMC7236921 DOI: 10.1186/s13195-020-00622-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/27/2020] [Indexed: 12/13/2022]
Abstract
Background γ-Secretase is a multiprotein protease that cleaves amyloid protein precursor (APP) and other type I transmembrane proteins. It has two catalytic subunits, presenilins 1 and 2 (PS1 and 2). In our previous report, we observed subtle differences in PS1- and PS2-mediated cleavages of select substrates and slightly different potencies of PS1 versus PS2 inhibition for select γ-secretase inhibitors (GSIs) on various substrates. In this study, we investigated whether γ-secretase modulators (GSMs) and inverse γ-secretase modulators (iGSMs) modulate γ-secretase processivity using multiple different substrates. We next used HEK 293T cell lines in which PSEN1 or PSEN2 was selectively knocked out to investigate processivity and response to GSMs and iGSMs. Methods For cell-free γ-secretase cleavage assay, recombinant substrates were incubated with CHAPSO-solubilized CHO or HEK 293T cell membrane with GSMs or iGSMs in suitable buffer. For cell-based assay, cDNA encoding substrates were transfected into HEK 293T cells. Cells were then treated with GSMs or iGSMs, and conditioned media were collected. Aβ and Aβ-like peptide production from cell-free and cell-based assay were measured by ELISA and mass spectrometry. Result These studies demonstrated that GSMs are highly selective for effects on APP, whereas iGSMs have a more promiscuous effect on many substrates. Surprisingly, iGSMs actually appear to act as like GSIs on select substrates. The data with PSEN1 or PSEN2 knocked out HEK 293T reveal that PS1 has higher processivity and response to GSMs than PS2, but PS2 has higher response to iGSM. Conclusion Collectively, these data indicate that GSMs are likely to have limited target-based toxicity. In addition, they show that iGSMs may act as substrate-selective GSIs providing a potential new route to identify leads for substrate-selective inhibitors of certain γ-secretase-mediated signaling events. With growing concerns that long-term β-secretase inhibitor is limited by target-based toxicities, such data supports continued development of GSMs as AD prophylactics.
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Affiliation(s)
- Christian B Lessard
- Department of Neuroscience and Neurology, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, PO Box 100159, Gainesville, FL, 32610, USA
| | - Edgardo Rodriguez
- Department of Pharmacology and Therapeutics, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Thomas B Ladd
- Department of Neuroscience and Neurology, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, PO Box 100159, Gainesville, FL, 32610, USA
| | - Lisa M Minter
- Department of Veterinary and Animal Sciences, Center for Bioactive Delivery, Institute for Applied Life Sciences, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Barbara A Osborne
- Department of Veterinary and Animal Sciences, Center for Bioactive Delivery, Institute for Applied Life Sciences, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Lucio Miele
- Department of Genetics and Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Todd E Golde
- Department of Neuroscience and Neurology, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, PO Box 100159, Gainesville, FL, 32610, USA.
| | - Yong Ran
- Department of Neuroscience and Neurology, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, PO Box 100159, Gainesville, FL, 32610, USA.
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Mutter ST, Turner M, Deeth RJ, Platts JA. Molecular dynamics simulations of copper binding to amyloid-β Glu22 mutants. Heliyon 2020; 6:e03071. [PMID: 31909253 DOI: 10.1016/j.heliyon.2019.e03071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 11/25/2019] [Accepted: 12/13/2019] [Indexed: 11/21/2022] Open
Abstract
We report microsecond timescale ligand field molecular dynamics simulations of the copper complexes of three known mutants of the amyloid-β peptide, E22G, E22Q and E22K, alongside the naturally occurring sequence. We find that all three mutants lead to formation of less compact structures than the wild-type: E22Q is the most similar to the native peptide, while E22G and especially E22K are markedly different in size, shape and stability. Turn and coil structures dominate all structures studied but subtle differences in helical and β-sheet distribution are noted, especially in the C-terminal region. The origin of these changes is traced to disruption of key salt bridges: in particular, the Asp23-Lys28 bridge that is prevalent in the wild-type is absent in E22G and E22K, while Lys22 in the latter mutant forms a strong association with Asp23. We surmise that the drastically different pattern of salt bridges in the mutants lead to adoption of a different structural ensemble of the peptide backbone, and speculate that this might affect the ability of the mutant peptides to aggregate in the same manner as known for the wild-type.
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Huang H, Lou X, Hu B, Zhou Z, Chen J, Tian Y. A comprehensive study on the generation of reactive oxygen species in Cu-Aβ-catalyzed redox processes. Free Radic Biol Med 2019; 135:125-131. [PMID: 30849487 DOI: 10.1016/j.freeradbiomed.2019.02.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/22/2019] [Accepted: 02/23/2019] [Indexed: 01/28/2023]
Abstract
In the amyloid plaques, a signature of AD, abnormally high Cu2+ concentrations are found bound to Aβ. Most of previous studies reported that Cu-Aβ could contribute to oxidative stress, as H2O2 and •OH are catalytically generated by Cu-Aβ with the assistance of biological reductant, with only one recent report stated that free O2•- is also generated in the Cu-Aβ catalyzed processes, where an indirect technique was applied. To comprehensively investigate the free radicals produced during this Cu-Aβ-mediated process with a biological reductant, DNA-cleavage assay, an indirect method, and two direct methods including electron paramagnetic resonance (EPR) spectroscopy and transient absorption spectroscopy (TAS), both having qualitative and quantitative power, were employed in this work. All the experimental results obtained from the three methods demonstrated that Cu-Aβ in the biological reducing environment was not only able to catalyze the production of H2O2 and •OH, but also to generate free O2•-. The results further indicated that O2•- was the precursor of H2O2 and •OH. It is also important to note that the results obtained from EPR spectroscopy and TAS provided direct evidence for the presence of O2•- and •OH. By virtue of the direct techniques, we also found that the longest peptide fragments of Aβ16, Aβ40, and Aβ42 produced the least radicals with a lowest rate. More interestingly, the fibrillar forms of Aβ generated less O2•- and •OH compared with oligomeric and monomeric forms.
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Affiliation(s)
- Hong Huang
- Department of Chemistry, School of Chemistry and Molecular Engineering, East China Normal University, Dongchuan Road 500, Shanghai, 200241, China; College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiahang Road 118, Jiaxing, 314001, China
| | - Xiaobing Lou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, North Zhongshan Road 3663, Shanghai, 200062, China
| | - Bingwen Hu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, North Zhongshan Road 3663, Shanghai, 200062, China
| | - Zhongneng Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, North Zhongshan Road 3663, Shanghai, 200062, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, North Zhongshan Road 3663, Shanghai, 200062, China
| | - Yang Tian
- State Key Laboratory of Precision Spectroscopy, East China Normal University, North Zhongshan Road 3663, Shanghai, 200062, China; Department of Chemistry, School of Chemistry and Molecular Engineering, East China Normal University, Dongchuan Road 500, Shanghai, 200241, China.
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Xu S, Nigam SM, Brodin L. Overexpression of SNX3 Decreases Amyloid-β Peptide Production by Reducing Internalization of Amyloid Precursor Protein. NEURODEGENER DIS 2018; 18:26-37. [PMID: 29414832 DOI: 10.1159/000486199] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 12/08/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Sorting nexins (SNXs) have diverse functions in protein sorting and membrane trafficking. Recently, single-nucleotide polymorphisms in SNX3 were found to be associated with Alzheimer disease. However, it remains unknown whether SNX3 participates in amyloid (A)β peptide production. OBJECTIVE To examine the role of SNX3 in Aβ production and APP processing. METHODS The effect of increased expression of SNX3 was studied in HEK293T cells. Aβ peptides were measured by immunoassay. Protein-protein association was analyzed by a bimolecular fluorescence complementation (BiFC) assay. APP uptake was measured with an α-bungarotoxin-binding assay, and flow cytometry was used to measure cell surface APP levels. RESULTS We found that overexpression of SNX3 in HEK293T cells decreases the levels of secreted Aβ and soluble N-terminal APP fragments (sAPPβ). The reduction correlated with a decreased association of APP with BACE1, as revealed by BiFC. This effect may, in part, be explained by a reduced internalization of APP; SNX3 overexpression reduced APP internalization as determined by an α-bungarotoxin-binding assay, and caused increased APP levels on the cell surface, as shown by flow cytometry. In addition, SNX3 overexpression increased the cellular levels of full-length APP. CONCLUSION These results provide evidence that SNX3 regulates Aβ production by influencing the internalization of APP.
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Affiliation(s)
- Shaohua Xu
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Saket M Nigam
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Lennart Brodin
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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12
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Rodriguez Camargo DC, Korshavn KJ, Jussupow A, Raltchev K, Goricanec D, Fleisch M, Sarkar R, Xue K, Aichler M, Mettenleiter G, Walch AK, Camilloni C, Hagn F, Reif B, Ramamoorthy A. Stabilization and structural analysis of a membrane-associated hIAPP aggregation intermediate. eLife 2017; 6:31226. [PMID: 29148426 PMCID: PMC5706959 DOI: 10.7554/elife.31226] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 11/14/2017] [Indexed: 12/21/2022] Open
Abstract
Membrane-assisted amyloid formation is implicated in human diseases, and many of the aggregating species accelerate amyloid formation and induce cell death. While structures of membrane-associated intermediates would provide tremendous insights into the pathology and aid in the design of compounds to potentially treat the diseases, it has not been feasible to overcome the challenges posed by the cell membrane. Here, we use NMR experimental constraints to solve the structure of a type-2 diabetes related human islet amyloid polypeptide intermediate stabilized in nanodiscs. ROSETTA and MD simulations resulted in a unique β-strand structure distinct from the conventional amyloid β-hairpin and revealed that the nucleating NFGAIL region remains flexible and accessible within this isolated intermediate, suggesting a mechanism by which membrane-associated aggregation may be propagated. The ability of nanodiscs to trap amyloid intermediates as demonstrated could become one of the most powerful approaches to dissect the complicated misfolding pathways of protein aggregation.
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Affiliation(s)
- Diana C Rodriguez Camargo
- Institute for Advanced Study, Technische Universität München, Garching, Germany.,Program in Biophysics, Department of Chemistry, University of Michigan, Ann Arbor, United States.,Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Garching, Germany
| | - Kyle J Korshavn
- Program in Biophysics, Department of Chemistry, University of Michigan, Ann Arbor, United States
| | - Alexander Jussupow
- Institute for Advanced Study, Technische Universität München, Garching, Germany
| | - Kolio Raltchev
- Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Garching, Germany
| | - David Goricanec
- Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Garching, Germany
| | | | - Riddhiman Sarkar
- Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Garching, Germany
| | - Kai Xue
- Helmholtz Zentrum München, Neuherberg, Germany
| | | | | | | | - Carlo Camilloni
- Institute for Advanced Study, Technische Universität München, Garching, Germany
| | - Franz Hagn
- Institute for Advanced Study, Technische Universität München, Garching, Germany.,Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Garching, Germany.,Helmholtz Zentrum München, Neuherberg, Germany
| | - Bernd Reif
- Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Garching, Germany.,Helmholtz Zentrum München, Neuherberg, Germany
| | - Ayyalusamy Ramamoorthy
- Institute for Advanced Study, Technische Universität München, Garching, Germany.,Program in Biophysics, Department of Chemistry, University of Michigan, Ann Arbor, United States
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13
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Xu S, Zhang L, Brodin L. Overexpression of SNX7 reduces Aβ production by enhancing lysosomal degradation of APP. Biochem Biophys Res Commun 2017; 495:12-19. [PMID: 29080748 DOI: 10.1016/j.bbrc.2017.10.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 10/23/2017] [Indexed: 01/01/2023]
Abstract
Abnormal production of amyloid-β peptides (Aβ) by proteolytic processing of amyloid precursor protein (APP) is thought to be central to the pathogenesis of Alzheimer's disease (AD). Although many efforts have been made to investigate mechanisms that regulate APP processing, many details remain incompletely understood. Sorting nexins (SNXs) are a family of proteins which are involved in many intracellular trafficking events. Several SNXs have been implicated in APP processing and Aβ production. In this study, we extended the investigation to SNX7. We found that overexpression of SNX7 in HEK293T cells reduces the levels of secreted Aβ and β-cleaved N-terminal APP fragments (sAPPβ). Moreover, SNX7 overexpression caused a significant reduction of the steady-state levels of APP as well as of the cell surface APP levels. By using NH4Cl and Bafilomycin A1 to inhibit the lysosomal degradative pathway, we found that the reduction of APP induced by SNX7 overexpression was prevented by such inhibition. No change in the cell surface distribution or steady-state levels of BACE1 was detected after overexpression of SNX7. Taken together, these results suggest that SNX7 regulates Aβ production by directing APP for degradation.
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Affiliation(s)
- Shaohua Xu
- Department of Neuroscience, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Lu Zhang
- Department of Medicine, Karolinska Institutet, SE-171 76, Stockholm, Sweden
| | - Lennart Brodin
- Department of Neuroscience, Karolinska Institutet, SE-171 77, Stockholm, Sweden.
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14
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Ahmad I, Mozhi A, Yang L, Han Q, Liang X, Li C, Yang R, Wang C. Graphene oxide-iron oxide nanocomposite as an inhibitor of Aβ 42 amyloid peptide aggregation. Colloids Surf B Biointerfaces 2017; 159:540-545. [PMID: 28846964 DOI: 10.1016/j.colsurfb.2017.08.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 08/03/2017] [Accepted: 08/13/2017] [Indexed: 10/19/2022]
Abstract
Inhibiting amyloid β (Aβ) aggregation has drawn much attention because it is one of the main reasons for the cause of Alzheimer's disease (AD). Here we have synthesized a nanocomposite of graphene oxide-iron oxide (GOIO) and demonstrated its ability of modulating Aβ aggregation. The inhibition effects of the GOIO nanocomposite on Aβ aggregates was studied by Thioflavin T fluorescence assay, circular dichroism and transmission electron microscopy, respectively. Furthermore, the cell viability study revealed that the GOIO nanocomposite can reduce the toxicity of Aβ fibrils to neuroblastoma cells. Our results demonstrated that the combination of GO and IO as a nanocomposite material has a potential use for the design new therapeutic agents for the treatment of Alzheimer's disease.
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Affiliation(s)
- Israr Ahmad
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Anbu Mozhi
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Lin Yang
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Qiusen Han
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Xingjie Liang
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Chan Li
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Rong Yang
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 100190, PR China.
| | - Chen Wang
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100190, PR China.
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15
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Abstract
Protein misfolding and aggregation have been associated with the onset of neurodegenerative disorders. Recent studies demonstrate that the aggregation process can result in a high diversity of protein conformational states, however the identity of the specific species responsible for the cellular damage is still unclear. Here, we use yeast as a model to systematically analyse the intracellular effect of expressing 21 variants of the amyloid-ß-peptide, engineered to cover a continuous range of intrinsic aggregation propensities. We demonstrate the existence of a striking negative correlation between the aggregation propensity of a given variant and the oxidative stress it elicits. Interestingly, each variant generates a specific distribution of protein assemblies in the cell. This allowed us to identify the aggregated species that remain diffusely distributed in the cytosol and are unable to coalesce into large protein inclusions as those causing the highest levels of oxidative damage. Overall, our results indicate that the formation of large insoluble aggregates may act as a protective mechanism to avoid cellular oxidative stress.
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Affiliation(s)
- Anita Carija
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Susanna Navarro
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Natalia Sanchez de Groot
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Salvador Ventura
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
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16
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Badhwar A, Brown R, Stanimirovic DB, Haqqani AS, Hamel E. Proteomic differences in brain vessels of Alzheimer's disease mice: Normalization by PPARγ agonist pioglitazone. J Cereb Blood Flow Metab 2017; 37:1120-1136. [PMID: 27339263 PMCID: PMC5363486 DOI: 10.1177/0271678x16655172] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cerebrovascular insufficiency appears years prior to clinical symptoms in Alzheimer's disease. The soluble, highly toxic amyloid-β species, generated from the amyloidogenic processing of amyloid precursor protein, are known instigators of the chronic cerebrovascular insufficiency observed in both Alzheimer's disease patients and transgenic mouse models. We have previously demonstrated that pioglitazone potently reverses cerebrovascular impairments in a mouse model of Alzheimer's disease overexpressing amyloid-β. In this study, we sought to characterize the effects of amyloid-β overproduction on the cerebrovascular proteome; determine how pioglitazone treatment affected the altered proteome; and analyze the relationship between normalized protein levels and recovery of cerebrovascular function. Three-month-old wildtype and amyloid precursor protein mice were treated with pioglitazone- (20 mg/kg/day, 14 weeks) or control-diet. Cerebral arteries were surgically isolated, and extracted proteins analyzed by gel-free and gel-based mass spectrometry. 193 cerebrovascular proteins were abnormally expressed in amyloid precursor protein mice. Pioglitazone treatment rescued a third of these proteins, mainly those associated with oxidative stress, promotion of cerebrovascular vasocontractile tone, and vascular compliance. Our results demonstrate that amyloid-β overproduction perturbs the cerebrovascular proteome. Recovery of cerebrovascular function with pioglitazone is associated with normalized levels of key proteins in brain vessel function, suggesting that pioglitazone-responsive cerebrovascular proteins could be early biomarkers of Alzheimer's disease.
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Affiliation(s)
- AmanPreet Badhwar
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
| | - Rebecca Brown
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Danica B Stanimirovic
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Arsalan S Haqqani
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Edith Hamel
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
- Edith Hamel, Laboratory of Cerebrovascular research, Montreal Neurological Institute, 3801 University St., Montréal, QC, H3A 2B4, Canada.
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17
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Shu L, Sun W, Li L, Xu Z, Lin L, Xie P, Shen H, Huang L, Xu Q, Jin P, Li X. Genome-wide alteration of 5-hydroxymenthylcytosine in a mouse model of Alzheimer's disease. BMC Genomics 2016; 17:381. [PMID: 27207465 PMCID: PMC4875608 DOI: 10.1186/s12864-016-2731-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 05/12/2016] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common form of neurodegenerative disorder that leads to a decline in cognitive function. In AD, aggregates of amyloid β peptide precede the accumulation of neurofibrillary tangles, both of which are hallmarks of the disease. The great majority (>90 %) of the AD cases are not originated from genetic defects, therefore supporting the central roles of epigenetic modifications that are acquired progressively during the life span. Strong evidences have indicated the implication of epigenetic modifications, including histone modification and DNA methylation, in AD. Recent studies revealed that 5-hydroxymethylcytosine (5hmC) is dynamically regulated during neurodevelopment and aging. RESULTS We show that amyloid peptide 1-42 (Aβ1-42) could significantly reduce the overall level of 5hmC in vitro. We found that the level of 5hmC displayed differential response to the pathogenesis in different brain regions, including the cortex, cerebellum, and hippocampus of APP-PSEN1 double transgenic (DTg) mice. We observed a significant decrease of overall 5hmC in hippocampus, but not in cortex and cerebellum, as the DTg mice aged. Genome-wide profiling identified differential hydroxymethylation regions (DhMRs) in DTg mice, which are highly enriched in introns, exons and intergenic regions. Gene ontology analyses indicated that DhMR-associated genes are highly enriched in multiple signaling pathways involving neuronal development/differentiation and neuronal function/survival. CONCLUSIONS 5hmC-mediated epigenetic regulation could potentially be involved in the pathogenesis of AD.
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Affiliation(s)
- Liqi Shu
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30022, USA
| | - Wenjia Sun
- Institute of Genetics, College of Life Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Liping Li
- The Children's Hospital, School of Medicine, Zhejiang University, 310052, Hangzhou, China
- Institute of Translational Medicine, School of Medicine, Zhejiang University, 310029, Hangzhou, China
| | - Zihui Xu
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30022, USA
- Department of Endocrinology, Wuhan Central Hospital, 430014, Wuhan, China
| | - Li Lin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30022, USA
| | - Pei Xie
- The Children's Hospital, School of Medicine, Zhejiang University, 310052, Hangzhou, China
- Institute of Translational Medicine, School of Medicine, Zhejiang University, 310029, Hangzhou, China
| | - Hui Shen
- The Children's Hospital, School of Medicine, Zhejiang University, 310052, Hangzhou, China
- Institute of Translational Medicine, School of Medicine, Zhejiang University, 310029, Hangzhou, China
| | - Luoxiu Huang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30022, USA
| | - Qi Xu
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, 100005, Beijing, China
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30022, USA.
| | - Xuekun Li
- The Children's Hospital, School of Medicine, Zhejiang University, 310052, Hangzhou, China.
- Institute of Translational Medicine, School of Medicine, Zhejiang University, 310029, Hangzhou, China.
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18
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Nalivaeva NN, Belyaev ND, Turner AJ. New Insights into Epigenetic and Pharmacological Regulation of Amyloid-Degrading Enzymes. Neurochem Res 2016; 41:620-30. [PMID: 26376806 DOI: 10.1007/s11064-015-1703-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/12/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
Abstract
Currently, deficit of amyloid β-peptide (Aβ) clearance from the brain is considered as one of the possible causes of amyloid accumulation and neuronal death in the sporadic form of Alzheimer's disease (AD). Aβ clearance can involve either specific proteases present in the brain or Aβ-binding/transport proteins. Among amyloid-degrading enzymes the most intensively studied are neprilysin (NEP) and insulin-degrading enzyme (IDE). Since ageing and development of brain pathologies is often accompanied by a deficit in the levels of expression and activity of these enzymes in the brain, there is an urgent need to understand the mechanisms involved in their regulation. We have recently reported that NEP and also an Aβ-transport protein, transthyretin are epigenetically co-regulated by the APP intracellular domain (AICD) and this regulation depends on the cell type and APP695 isoform expression in a process that can be regulated by the tyrosine kinase inhibitor, Gleevec. We have now extended our work and shown that, unlike NEP, another amyloid-degrading enzyme, IDE, is not related to over-expression of APP695 in neuroblastoma SH-SY5Y cells but is up-regulated by APP751 and APP770 isoforms independently of AICD but correlating with reduced HDAC1 binding to its promoter. Studying the effect of the nuclear retinoid X receptor agonist, bexarotene, on NEP and IDE expression, we have found that both enzymes can be up-regulated by this compound but this mechanism is not APP-isoform specific and does not involve AICD but, on the contrary, affects HDAC1 occupancy on the NEP gene promoter. These new insights into the mechanisms of NEP and IDE regulation suggest possible pharmacological targets in developing AD therapies.
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19
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Grouleff J, Irudayam SJ, Skeby KK, Schiøtt B. The influence of cholesterol on membrane protein structure, function, and dynamics studied by molecular dynamics simulations. Biochim Biophys Acta 2015; 1848:1783-95. [PMID: 25839353 DOI: 10.1016/j.bbamem.2015.03.029] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 12/12/2022]
Abstract
The plasma membrane, which encapsulates human cells, is composed of a complex mixture of lipids and embedded proteins. Emerging knowledge points towards the lipids as having a regulating role in protein function. Furthermore, insight from protein crystallography has revealed several different types of lipids intimately bound to membrane proteins and peptides, hereby possibly pointing to a site of action for the observed regulation. Cholesterol is among the lipid membrane constituents most often observed to be co-crystallized with membrane proteins, and the cholesterol levels in cell membranes have been found to play an essential role in health and disease. Remarkably little is known about the mechanism of lipid regulation of membrane protein function in health as well as in disease. Herein, we review molecular dynamics simulation studies aimed at investigating the effect of cholesterol on membrane protein and peptide properties. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Julie Grouleff
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Sheeba Jem Irudayam
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Katrine K Skeby
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Birgit Schiøtt
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.
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20
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Kong MY, Chen QY, Yao L, Wang YB. Spectroscopic study on the interaction of Aβ42 with di(picolyl)amine derivatives and the toxicity to SH-S5Y5 cells. Spectrochim Acta A Mol Biomol Spectrosc 2015; 138:225-228. [PMID: 25498817 DOI: 10.1016/j.saa.2014.11.062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/21/2014] [Accepted: 11/20/2014] [Indexed: 06/04/2023]
Abstract
In order to confirm the neurotoxicity of bifunctional chelators containing hydrophobic groups and metal chelating moiety, the interaction of di(picolyl)amine (dpa) derivatives toward Aβ42 peptide was investigated. Fluorescence titration reveals that a hydrophobic chelator (such as BODIPY) shows high binding affinity to amyloid Aβ42. Circular dichroism (CD) spectra confirm that the hydrophobic bifunctional chelator can decrease α-helix fraction and increase the β-sheet fraction of amyloid Aβ42. In particular, experimental results indicate that a bifunctional chelator can assemble with Cu(II)-Aβ42 forming chelator-Cu(II)-Aβ42 nanospheres, which are toxic to SH-S5Y5 cells. The hydrophobic interaction between the chelator and the amyloid peptide (Aβ42) has great contribution to the formation of neurotoxic chelator-Cu(II)-Aβ42 nanospheres. This work gives a general guide to the development of low cytotoxic inhibitors of Aβ42 aggregation.
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Affiliation(s)
- Meng-Yun Kong
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China
| | - Qiu-Yun Chen
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
| | - Ling Yao
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China
| | - Yin-Bing Wang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China
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21
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Villar-Piqué A, Ventura S. Protein aggregation propensity is a crucial determinant of intracellular inclusion formation and quality control degradation. Biochim Biophys Acta 2013; 1833:2714-2724. [PMID: 23856334 DOI: 10.1016/j.bbamcr.2013.06.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/21/2013] [Accepted: 06/24/2013] [Indexed: 01/13/2023]
Abstract
Protein aggregation is linked to many pathological conditions, including several neurodegenerative diseases. The aggregation propensities of proteins are thought to be controlled to a large extent by the physicochemical properties encoded in the primary sequence. We have previously exploited a set of amyloid β peptide (Aβ42) variants exhibiting a continuous gradient of intrinsic aggregation propensities to demonstrate that this rule applies in vivo in bacteria. In the present work we have characterized the behavior of these Aβ42 mutants when expressed in yeast. In contrast to bacteria, the intrinsic aggregation propensity is gated by yeast, in such a way that this property correlates with the formation of intracellular inclusions only above a specific aggregation threshold. Proteins displaying solubility levels above this threshold escape the inclusion formation pathway. In addition, the most aggregation-prone variants are selectively cleared by the yeast quality control degradation machinery. Thus, both inclusion formation and proteolysis target the same aggregation-prone variants and cooperate to minimize the presence of these potentially dangerous species in the cytosol. The demonstration that sorting to these pathways in eukaryotes is strongly influenced by protein primary sequence should facilitate the development of rational approaches to predict and hopefully prevent in vivo protein deposition.
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Affiliation(s)
- Anna Villar-Piqué
- Departament de Bioquímica i Biologia Molecular, Facultat de Biociències, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain; Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Salvador Ventura
- Departament de Bioquímica i Biologia Molecular, Facultat de Biociències, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain; Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain.
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