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Loeffler DA. Approaches for Increasing Cerebral Efflux of Amyloid-β in Experimental Systems. J Alzheimers Dis 2024:JAD240212. [PMID: 38875041 DOI: 10.3233/jad-240212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2024]
Abstract
Amyloid protein-β (Aβ) concentrations are increased in the brain in both early onset and late onset Alzheimer's disease (AD). In early onset AD, cerebral Aβ production is increased and its clearance is decreased, while increased Aβ burden in late onset AD is due to impaired clearance. Aβ has been the focus of AD therapeutics since development of the amyloid hypothesis, but efforts to slow AD progression by lowering brain Aβ failed until phase 3 trials with the monoclonal antibodies lecanemab and donanemab. In addition to promoting phagocytic clearance of Aβ, antibodies lower cerebral Aβ by efflux of Aβ-antibody complexes across the capillary endothelia, dissolving Aβ aggregates, and a "peripheral sink" mechanism. Although the blood-brain barrier is the main route by which soluble Aβ leaves the brain (facilitated by low-density lipoprotein receptor-related protein-1 and ATP-binding cassette sub-family B member 1), Aβ can also be removed via the blood-cerebrospinal fluid barrier, glymphatic drainage, and intramural periarterial drainage. This review discusses experimental approaches to increase cerebral Aβ efflux via these mechanisms, clinical applications of these approaches, and findings in clinical trials with these approaches in patients with AD or mild cognitive impairment. Based on negative findings in clinical trials with previous approaches targeting monomeric Aβ, increasing the cerebral efflux of soluble Aβ is unlikely to slow AD progression if used as monotherapy. But if used as an adjunct to treatment with lecanemab or donanemab, this approach might allow greater slowing of AD progression than treatment with either antibody alone.
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Affiliation(s)
- David A Loeffler
- Department of Neurology, Beaumont Research Institute, Corewell Health, Royal Oak, MI, USA
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2
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Ullah R, Lee EJ. Advances in Amyloid-β Clearance in the Brain and Periphery: Implications for Neurodegenerative Diseases. Exp Neurobiol 2023; 32:216-246. [PMID: 37749925 PMCID: PMC10569141 DOI: 10.5607/en23014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/25/2023] [Accepted: 08/23/2023] [Indexed: 09/27/2023] Open
Abstract
This review examines the role of impaired amyloid-β clearance in the accumulation of amyloid-β in the brain and the periphery, which is closely associated with Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). The molecular mechanism underlying amyloid-β accumulation is largely unknown, but recent evidence suggests that impaired amyloid-β clearance plays a critical role in its accumulation. The review provides an overview of recent research and proposes strategies for efficient amyloid-β clearance in both the brain and periphery. The clearance of amyloid-β can occur through enzymatic or non-enzymatic pathways in the brain, including neuronal and glial cells, blood-brain barrier, interstitial fluid bulk flow, perivascular drainage, and cerebrospinal fluid absorption-mediated pathways. In the periphery, various mechanisms, including peripheral organs, immunomodulation/immune cells, enzymes, amyloid-β-binding proteins, and amyloid-β-binding cells, are involved in amyloid-β clearance. Although recent findings have shed light on amyloid-β clearance in both regions, opportunities remain in areas where limited data is available. Therefore, future strategies that enhance amyloid-β clearance in the brain and/or periphery, either through central or peripheral clearance approaches or in combination, are highly encouraged. These strategies will provide new insight into the disease pathogenesis at the molecular level and explore new targets for inhibiting amyloid-β deposition, which is central to the pathogenesis of sporadic AD (amyloid-β in parenchyma) and CAA (amyloid-β in blood vessels).
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Affiliation(s)
- Rahat Ullah
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Neurology, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA
| | - Eun Jeong Lee
- Department of Brain Science, Ajou University School of Medicine, Suwon 16499, Korea
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3
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Webb AN, Spiers KM, Falkenberg G, Gu H, Dwibhashyam SS, Du Y, Zheng W, Nie LH. Distribution of Pb and Se in mouse brain following subchronic Pb exposure by using synchrotron X-ray fluorescence. Neurotoxicology 2022; 88:106-115. [PMID: 34793780 PMCID: PMC8748384 DOI: 10.1016/j.neuro.2021.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/10/2021] [Accepted: 11/12/2021] [Indexed: 02/09/2023]
Abstract
Lead (Pb) is a well-known neurotoxicant and environmental hazard. Recent experimental evidence has linked Pb exposure with neurological deterioration leading to neurodegenerative diseases, such as Alzheimer's disease. To understand brain regional distribution of Pb and its interaction with other metal ions, we used synchrotron micro-x-ray fluorescence technique (μ-XRF) to map the metal distribution pattern and to quantify metal concentrations in mouse brains. Lead-exposed mice received oral gavage of Pb acetate once daily for 4 weeks; the control mice received sodium acetate. Brain tissues were cut into slices and subjected for analysis. Synchrotron μ-XRF scans were run on the PETRA III P06 beamline (DESY). Coarse scans of the entire brain were performed to locate the cortex and hippocampus, after which scans with higher resolution were run in these areas. The results showed that: a) the total Pb intensity in Pb-exposed brain slices was significantly higher than in control brain; b) Pb typically deposited in localized particles of <10 um2 in both the Pb-exposed and control brain slices, with more of these particles in Pb-exposed samples; c) selenium (Se) was significantly correlated with Pb in these particles in the cortex and hippocampus/corpus callosum regions in the Pb-exposed samples, and the molar ratio of the Se and Pb in these particles is close to 1:1. These results indicated that Se may play a crucial role in Pb-induced neurotoxicity. Our findings call for further studies to investigate the relationship between Pb exposure and possible Se detoxification responses, and the implication in the etiology of Alzheimer's disease.
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Affiliation(s)
- Alexis N Webb
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, United States.
| | | | | | - Huiying Gu
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
| | - Sai S Dwibhashyam
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, United States.
| | - Yansheng Du
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
| | - Wei Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, United States.
| | - Linda H Nie
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, United States.
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Gu H, Territo PR, Persohn SA, Bedwell AA, Eldridge K, Speedy R, Chen Z, Zheng W, Du Y. Evaluation of chronic lead effects in the blood brain barrier system by DCE-CT. J Trace Elem Med Biol 2020; 62:126648. [PMID: 32980769 PMCID: PMC7655551 DOI: 10.1016/j.jtemb.2020.126648] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 08/20/2020] [Accepted: 09/16/2020] [Indexed: 11/26/2022]
Abstract
BACKGROUND Lead (Pb) is an environmental factor has been suspected of contributing to the dementia including Alzheimer's disease (AD). Our previous studies have shown that Pb exposure at the subtoxic dose increased brain levels of beta-amyloid (Aβ) and amyloid plaques, a pathological hallmark for AD, in amyloid precursor protein (APP) transgenic mice, and is hypothesized to inhibit Aβ clearance in the blood- cerebrospinal fluid (CSF) barrier. However, it remains unclear how different levels of Pb affect Aβ clearance in the whole blood-brain barrier system. This study was designed to investigate whether chronic exposure of Pb affected the permeability of the blood-brain barrier system by using the Dynamic Contrast-Enhanced Computerized Tomography (DCE-CT) method. METHODS DEC-CT was used to investigate whether chronic exposure of toxic Pb affected the permeability of the real-time blood brain barrier system. RESULTS Data showed that Pb exposure increased permeability surface area product, and also significantly induced brain perfusion. However, Pb exposure did not alter extracellular volumes or fractional blood volumes of mouse brain. CONCLUSION Our data suggest that Pb exposure at subtoxic and toxic levels directly targets the brain vasculature and damages the blood brain barrier system.
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Affiliation(s)
- Huiying Gu
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Paul R Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Scott A Persohn
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Amanda A Bedwell
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Kierra Eldridge
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Rachael Speedy
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Zhe Chen
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Wei Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States
| | - Yansheng Du
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States.
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5
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Early-life Pb exposure as a potential risk factor for Alzheimer’s disease: are there hazards for the Mexican population? J Biol Inorg Chem 2019; 24:1285-1303. [DOI: 10.1007/s00775-019-01739-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 10/25/2019] [Indexed: 12/30/2022]
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6
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Association between blood lead level and subsequent Alzheimer's disease mortality. Environ Epidemiol 2019; 3:e045. [PMID: 31342005 PMCID: PMC6582444 DOI: 10.1097/ee9.0000000000000045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 03/13/2019] [Indexed: 02/01/2023] Open
Abstract
Background: Previous studies suggest that cumulative lead exposure is associated with cognitive decline, but its relation with Alzheimer’s disease (AD) remains unclear. Therefore, this study investigated the longitudinal association between blood lead level (BLL) and AD mortality. Methods: This study included 8,080 elders (60 years or older) with BLL data from the 1999 to 2008 US National Health and Nutrition Examination Survey. Mortality was determined from linked 1999–2014 National Death Index data. A causal diagram presented causal assumptions and identified a sufficient set of confounders: age, sex, poverty, race/ethnicity, and smoking. Cox proportional hazard models were used to determine the association between BLL and subsequent AD mortality. Impacts of competing risks and design effect were also assessed. Adjusted hazard rate ratio (HRR) and 95% confidence interval (CI) were reported. Results: Follow-up ranged from <1 to 152 months (median, 74). Eighty-one participants died from AD over 632,075 total person-months at risk. An increase in BLL was associated with an increase in AD mortality after adjusting for identified confounders. We estimated that those with BLL of 1.5 and 5 μg/dl had 1.2 (95% CI = 0.70, 2.1) and 1.4 (95% CI = 0.54, 3.8) times the rate of AD mortality compared to those with BLL of 0.3 μg/dl, respectively, after accounting for competing risks. Adjusted HRRs were 1.5 (95% CI = 0.81, 2.9) and 2.1 (95% CI = 0.70, 6.3), respectively, after considering design effect. Conclusions: This longitudinal study demonstrated a positive, albeit not statistically significant, association between BLL and AD mortality after adjustment for competing risks or design effect.
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Diabetes and Alzheimer's Disease: A Link not as Simple as it Seems. Neurochem Res 2018; 44:1271-1278. [PMID: 30523576 DOI: 10.1007/s11064-018-2690-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/11/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023]
Abstract
Type 2 diabetes mellitus is associated with an increased risk to develop Alzheimer disease, however, the underlying mechanisms for this association are still unclear. In this review we will provide a critical overview of the major findings coming from clinical studies and animal models.
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Ueno M. Elucidation of mechanism of blood-brain barrier damage for prevention and treatment of vascular dementia. Rinsho Shinkeigaku 2017; 57:95-109. [PMID: 28228623 DOI: 10.5692/clinicalneurol.cn-001004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
It is well-known that the blood-brain barrier (BBB) plays significant roles in transporting intravascular substances into the brain. The BBB in cerebral capillaries essentially impedes the influx of intravascular compounds from the blood to the brain, while nutritive substances, such as glucose, can be selectively transported through several types of influx transporters in endothelial cells. In the choroid plexus, intravascular substances can invade the parenchyma as fenestrations exist in endothelial cells of capillaries. However, the substances cannot invade the ventricles easily as there are tight junctions between epithelial cells in the choroid plexus. This restricted movement of the substances across the cytoplasm of the epithelial cells constitutes a blood-cerebrospinal fluid barrier (BCSFB). In the brain, there are circumventricular organs, in which the barrier function is imperfect in capillaries. Accordingly, it is reasonable to consider that intravascular substances can move in and around the parenchyma of the organs. Actually, it was reported in mice that intravascular substances moved in the corpus callosum, medial portions of the hippocampus, and periventricular areas via the subfornical organs or the choroid plexus. Regarding pathways of intracerebral interstitial and cerebrospinal fluids to the outside of the brain, two representative drainage pathways, or perivascular drainage and glymphatic pathways, are being established. The first is the pathway in a retrograde direction to the blood flow through the basement membrane in walls of cerebral capillaries, the tunica media of arteries, and the vessels walls of the internal carotid artery. The second is in an anterograde direction to blood flow through the para-arterial routes, aquaporin 4-dependent transport through the astroglial cytoplasm, and para-venous routes, and then the fluids drain into the subarachnoid CSF. These fluids are finally considered to drain into the cervical lymph nodes or veins. These clearance pathways may play a role in maintenance of the barrier in the entire brain. Obstruction of the passage of fluids through the perivascular drainage and glymphatic pathways as well as damage of the BBB and BCSFB may induce several kinds of brain disorders, such as vascular dementia. In this review, we focus on the relationship between damage of the barriers and the pathogenesis of vascular dementia and introduce recent findings including our experimental data using animal models.
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Affiliation(s)
- Masaki Ueno
- Inflammation Pathology, Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University
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Ueno M, Chiba Y, Murakami R, Matsumoto K, Kawauchi M, Fujihara R. Blood-brain barrier and blood-cerebrospinal fluid barrier in normal and pathological conditions. Brain Tumor Pathol 2016; 33:89-96. [PMID: 26920424 DOI: 10.1007/s10014-016-0255-7] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 02/16/2016] [Indexed: 01/13/2023]
Abstract
Blood-borne substances can invade into the extracellular spaces of the brain via endothelial cells in sites without the blood-brain barrier (BBB), and can travel through the interstitial fluid (ISF) of the brain parenchyma adjacent to non-BBB sites. It has been shown that cerebrospinal fluid (CSF) drains directly into the blood via the arachnoid villi and also into lymph nodes via the subarachnoid spaces of the brain, while ISF drains into the cervical lymph nodes through perivascular drainage pathways. In addition, the glymphatic pathway of fluids, characterized by para-arterial pathways, aquaporin4-dependent passage through astroglial cytoplasm, interstitial spaces, and paravenous routes, has been established. Meningeal lymphatic vessels along the superior sagittal sinus were very recently discovered. It is known that, in mice, blood-borne substances can be transferred to areas with intact BBB function, such as the medial regions of the hippocampus, presumably through leaky vessels in non-BBB sites. In the present paper, we review the clearance mechanisms of interstitial substances, such as amyloid-β peptides, as well as summarize models of BBB deterioration in response to different types of insults, including acute ischemia followed by reperfusion, hypertension, and chronic hypoperfusion. Lastly, we discuss the relationship between perivascular clearance and brain disorders.
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Affiliation(s)
- Masaki Ueno
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan.
| | - Yoichi Chiba
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan
| | - Ryuta Murakami
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan
| | - Koichi Matsumoto
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan
| | - Machi Kawauchi
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan
| | - Ryuji Fujihara
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan
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10
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Immunohistochemical analysis of transporters related to clearance of amyloid-β peptides through blood–cerebrospinal fluid barrier in human brain. Histochem Cell Biol 2015; 144:597-611. [DOI: 10.1007/s00418-015-1366-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2015] [Indexed: 01/25/2023]
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11
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Gu H, Zhong Z, Jiang W, Du E, Dodel R, Farlow MR, Zheng W, Du Y. The role of choroid plexus in IVIG-induced beta-amyloid clearance. Neuroscience 2014; 270:168-176. [PMID: 24747018 DOI: 10.1016/j.neuroscience.2014.04.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 03/26/2014] [Accepted: 04/07/2014] [Indexed: 12/20/2022]
Abstract
We have shown that intravenous immunoglobulin (IVIG) contains anti-Aβ autoantibodies and IVIG could induce beta amyloid (Aβ) efflux from cerebrospinal fluid (CSF) to blood in both Multiple Sclerosis (MS) and Alzheimer disease (AD) patients. However, the molecular mechanism underlying IVIG-induced Aβ efflux remains unclear. In this study, we used amyloid precursor protein (AβPP) transgenic mice to investigate if the IVIG could induce efflux of Aβ from the brain and whether low-density lipoprotein receptor-related protein-1 (LRP1), a hypothetic Aβ transporter in blood-CSF barrier (BCB); could mediate this clearance process. We currently provide strong evidence to demonstrate that IVIG could reduce brain Aβ levels by pulling Aβ into the blood system in AβPP transgenic mice. In the mechanistic study, IVIG could induce Aβ efflux through the in vitro BCB membrane formed by cultured BCB epithelial cells. Both receptor-associated protein (RAP; a functional inhibitor of LRP1), and LRP1 siRNA were able to significantly inhibit the Aβ efflux. Should Aβ prove to be the underlying cause of AD, our results strongly suggest that IVIG could be beneficial in the therapy for AD by inducing efflux of Aβ from the brain through the LRP1 in the BCB.
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Affiliation(s)
- Huiying Gu
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202
| | - Zhaohui Zhong
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202
- Department of General Surgery, Peking University People's Hospital, Beijing 100044, China
| | - Wendy Jiang
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907
| | - Eileen Du
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202
| | - Richard Dodel
- Department of Neurology, Philipps University Marburg, Marburg, Germary
| | - Martin R Farlow
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202
| | - Wei Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907
| | - Yansheng Du
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, 46202
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907
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Charton J, Gauriot M, Guo Q, Hennuyer N, Marechal X, Dumont J, Hamdane M, Pottiez V, Landry V, Sperandio O, Flipo M, Buee L, Staels B, Leroux F, Tang WJ, Deprez B, Deprez-Poulain R. Imidazole-derived 2-[N-carbamoylmethyl-alkylamino]acetic acids, substrate-dependent modulators of insulin-degrading enzyme in amyloid-β hydrolysis. Eur J Med Chem 2014; 79:184-93. [PMID: 24735644 DOI: 10.1016/j.ejmech.2014.04.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 03/31/2014] [Accepted: 04/04/2014] [Indexed: 11/28/2022]
Abstract
Insulin degrading enzyme (IDE) is a highly conserved zinc metalloprotease that is involved in the clearance of various physiologically peptides like amyloid-beta and insulin. This enzyme has been involved in the physiopathology of diabetes and Alzheimer's disease. We describe here a series of small molecules discovered by screening. Co-crystallization of the compounds with IDE revealed a binding both at the permanent exosite and at the discontinuous, conformational catalytic site. Preliminary structure-activity relationships are described. Selective inhibition of amyloid-beta degradation over insulin hydrolysis was possible. Neuroblastoma cells treated with the optimized compound display a dose-dependent increase in amyloid-beta levels.
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Affiliation(s)
- Julie Charton
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Marion Gauriot
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Qing Guo
- Ben-May Institute for Cancer Research, The University of Chicago, W421 Chicago, IL, USA
| | - Nathalie Hennuyer
- Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; INSERM U1011 Nuclear Receptors, Cardiovascular Diseases and Diabetes, Lille F-59000, France; European Genomic Institute for Diabetes (EGID), FR 3508, Lille F-59000, France
| | - Xavier Marechal
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Julie Dumont
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Malika Hamdane
- Univ Lille Nord de France, Lille F-59000, France; INSERM U837 Neurodegenerative Diseases and Neuronal Death, Lille F-59000, France; CHRU, Lille F-59000, France
| | - Virginie Pottiez
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Valerie Landry
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Olivier Sperandio
- CDithem Platform/IGM, Paris, France; Inserm UMR-S 973/MTi, University Paris Diderot, Paris, France
| | - Marion Flipo
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Luc Buee
- Univ Lille Nord de France, Lille F-59000, France; INSERM U837 Neurodegenerative Diseases and Neuronal Death, Lille F-59000, France; CHRU, Lille F-59000, France
| | - Bart Staels
- Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; INSERM U1011 Nuclear Receptors, Cardiovascular Diseases and Diabetes, Lille F-59000, France; European Genomic Institute for Diabetes (EGID), FR 3508, Lille F-59000, France
| | - Florence Leroux
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France
| | - Wei-Jen Tang
- Ben-May Institute for Cancer Research, The University of Chicago, W421 Chicago, IL, USA
| | - Benoit Deprez
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France.
| | - Rebecca Deprez-Poulain
- INSERM U761 Biostructures and Drug Discovery, Lille, France; Univ Lille Nord de France, Lille F-59000, France; Institut Pasteur de Lille, IFR 142, Lille F-59000, France; PRIM, Lille F-59000, France; CDithem Platform/IGM, Paris, France.
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13
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Fu X, Zeng A, Zheng W, Du Y. Upregulation of zinc transporter 2 in the blood-CSF barrier following lead exposure. Exp Biol Med (Maywood) 2014; 239:202-12. [PMID: 24311739 PMCID: PMC3928640 DOI: 10.1177/1535370213509213] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Zinc (Zn) is an essential element for normal brain function; an abnormal Zn homeostasis in brain and the cerebrospinal fluid (CSF) has been implied in the etiology of Alzheimer's disease (AD). However, the mechanisms that regulate Zn transport in the blood-brain interface remain unknown. This study was designed to investigate Zn transport by the blood-CSF barrier (BCB) in the choroid plexus, with a particular focus on Zn transporter-2 (ZnT2), and to understand if lead (Pb) accumulation in the choroid plexus disturbed the Zn regulatory function in the BCB. Confocal microscopy, quantitative PCR and western blot demonstrated the presence of ZnT2 in the choroidal epithelia; ZnT2 was primarily in cytosol in freshly isolated plexus tissues but more toward the peripheral membrane in established choroidal Z310 cells. Exposure of rats to Pb (single ip injection of 50 mg Pb acetate/kg) for 24 h increased ZnT2 fluorescent signals in plexus tissues by confocal imaging and protein expression by western blot. Similar results were obtained by in vitro experiments using Z310 cells. Further studies using cultured cells and a two-chamber Transwell device showed that Pb treatment significantly reduced the cellular Zn concentration and led to an increased transport of Zn across the BCB, the effect that may be due to the increased ZnT2 by Pb exposure. Taken together, these results indicate that ZnT2 is present in the BCB; Pb exposure increases the ZnT2 expression in choroidal epithelial cells by a yet unknown mechanism and as a result, more Zn ions may be deposited into the intracellular Zn pool, leading to a relative Zn deficiency state in the cytoplasm at the BCB.
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Affiliation(s)
- Xue Fu
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Andrew Zeng
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Wei Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Yansheng Du
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
- School of Medicine, Indiana University, Indianapolis, IN 46202, USA
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Hu HH, Bian YC, Liu Y, Sheng R, Jiang HD, Yu LS, Hu YZ, Zeng S. Evaluation of blood–brain barrier and blood–cerebrospinal fluid barrier permeability of 2-phenoxy-indan-1-one derivatives using in vitro cell models. Int J Pharm 2014; 460:101-7. [DOI: 10.1016/j.ijpharm.2013.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 10/29/2013] [Accepted: 11/08/2013] [Indexed: 01/13/2023]
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15
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Chen KC, Chang SS, Tsai FJ, Chen CYC. Han ethnicity-specific type 2 diabetic treatment from traditional Chinese medicine? J Biomol Struct Dyn 2012; 31:1219-35. [PMID: 23146021 DOI: 10.1080/07391102.2012.732340] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Insulin-degrading enzyme (IDE) gene is one of the type 2 diabetes mellitus susceptibility genes specific to the Han Chinese population. IDE, a zinc-metalloendopeptidase, is a potential target for controlling insulin degradation. Potential lead compounds for IDE inhibition were identified from traditional Chinese medicine (TCM) through virtual screening and evaluation of their pharmacokinetic properties of absorption, distribution, metabolism, excretion, and toxicity. Molecular dynamics (MD) simulation was performed to validate the stability of complexes from docking simulation. The top three TCM compounds, dihydrocaffeic acid, isopraeroside IV, and scopolin, formed stable H-bond interactions with key residue Asn139, and were linked to active pocket residues His108, His112, and Glu189 through zinc. Torsion angle trajectories also indicated some stable interactions for each ligand with IDE. Molecular level analysis revealed that the TCM candidates might affect IDE through competitive binding to the active site and steric hindrance. Structural feature analysis reveals that high amounts of hydroxyl groups and carboxylic moieties contribute to anchor the ligand within the complex. Hence, we suggest the top three TCM compounds as potential inhibitor leads against IDE protein to control insulin degradation for type 2 diabetes mellitus. An animated interactive 3D complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:29.
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Affiliation(s)
- Kuan-Chung Chen
- a Graduate Institute of Pharmaceutical Chemistry, China Medical University , Taichung , 40402 , Taiwan
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16
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Gu H, Robison G, Hong L, Barrea R, Wei X, Farlow MR, Pushkar YN, Du Y, Zheng W. Increased β-amyloid deposition in Tg-SWDI transgenic mouse brain following in vivo lead exposure. Toxicol Lett 2012; 213:211-9. [PMID: 22796588 DOI: 10.1016/j.toxlet.2012.07.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 06/30/2012] [Accepted: 07/03/2012] [Indexed: 12/01/2022]
Abstract
Previous studies in humans and animals have suggested a possible association between lead (Pb) exposure and the etiology of Alzheimer's disease (AD). Animals acutely exposed to Pb display an over-expressed amyloid precursor protein (APP) and the ensuing accumulation of beta-amyloid (Aβ) in brain extracellular spaces. This study was designed to examine whether in vivo Pb exposure increased brain concentrations of Aβ, resulting in amyloid plaque deposition in brain tissues. Human Tg-SWDI APP transgenic mice, which genetically over-express amyloid plaques at age of 2-3 months, received oral gavages of 50mg/kg Pb acetate once daily for 6 weeks; a control group of the same mouse strain received the same molar concentration of Na acetate. ELISA results revealed a significant increase of Aβ in the CSF, brain cortex and hippocampus. Immunohistochemistry displayed a detectable increase of amyloid plaques in brains of Pb-exposed animals. Neurobehavioral test using Morris water maze showed an impaired spatial learning ability in Pb-treated mice, but not in C57BL/6 wild type mice with the same age. In vitro studies further uncovered that Pb facilitated Aβ fibril formation. Moreover, the synchrotron X-ray fluorescent studies demonstrated a high level of Pb present in amyloid plaques in mice exposed to Pb in vivo. Taken together, these data indicate that Pb exposure with ensuing elevated Aβ level in mouse brains appears to be associated with the amyloid plaques formation. Pb apparently facilitates Aβ fibril formation and participates in deposition of amyloid plaques.
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Affiliation(s)
- Huiying Gu
- Department of Neurology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States.
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17
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Genome-wide expression and methylation profiling in the aged rodent brain due to early-life Pb exposure and its relevance to aging. Mech Ageing Dev 2012; 133:435-43. [PMID: 22613225 DOI: 10.1016/j.mad.2012.05.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 04/28/2012] [Accepted: 05/05/2012] [Indexed: 11/23/2022]
Abstract
In this study, we assessed global gene expression patterns in adolescent mice exposed to lead (Pb) as infants and their aged siblings to identify reprogrammed genes. Global expression on postnatal day 20 and 700 was analyzed and genes that were down- and up-regulated (≥2 fold) were identified, clustered and analyzed for their relationship to DNA methylation. About 150 genes were differentially expressed in old age. In normal aging, we observed an up-regulation of genes related to the immune response, metal-binding, metabolism and transcription/transduction coupling. Prior exposure to Pb revealed a repression in these genes suggesting that disturbances in developmental stages of the brain compromise the ability to defend against age-related stressors, thus promoting the neurodegenerative process. Overexpression and repression of genes corresponded with their DNA methylation profile.
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18
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Loef M, Mendoza LF, Walach H. Lead (Pb) and the Risk of Alzheimer’s disease or cognitive decline: A systematic review. TOXIN REV 2011. [DOI: 10.3109/15569543.2011.624664] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Glebov K, Schütze S, Walter J. Functional relevance of a novel SlyX motif in non-conventional secretion of insulin-degrading enzyme. J Biol Chem 2011; 286:22711-5. [PMID: 21576244 DOI: 10.1074/jbc.c110.217893] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin-degrading enzyme (IDE) is a Zn(2+) metalloprotease with a characteristic inverted catalytic motif. IDE is ubiquitously expressed and degrades peptide substrates including insulin, endorphin, and the amyloid-β peptide. Although IDE is mainly expressed in the cytosol, it can also be found on the cell surface and in secreted form in extracellular fluids. As IDE lacks a characteristic signal sequence that targets the protein to the classical secretory pathway, release of the enzyme involves non-conventional mechanisms. However, functional domains of IDE involved in its secretion remain elusive. By bioinformatical, biochemical, and cell biological methods, we identified a novel amino acid motif ((853)EKPPHY(858)) close to the C terminus of IDE and characterized its function in the non-conventional secretion of the protein. Because of its close homology to an amino acid sequence found in bacterial proteins belonging to the SlyX family, we propose to call it the SlyX motif. Mutagenesis revealed that deletion of this motif strongly decreased the release of IDE, whereas deletion of a potential microbody-targeting signal at the extreme C terminus had little effect on secretion. The combined data indicate that the non-conventional secretion of IDE is regulated by the newly identified SlyX motif.
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