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Zuliani G, Marsillach J, Trentini A, Rosta V, Cervellati C. Lipoprotein-Associated Phospholipase A2 Activity as Potential Biomarker of Vascular Dementia. Antioxidants (Basel) 2023; 12:597. [PMID: 36978845 PMCID: PMC10045550 DOI: 10.3390/antiox12030597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 03/04/2023] Open
Abstract
A wealth of evidence suggests that Lipoprotein-associated phospholipase A2 (Lp-PLA2) plays a relevant role in atherogenesis and inflammation, which in turn are associated with the risk of developing dementia. The aim of this study was to evaluate whether serum Lp-PLA2 activity might be an early and/or late biomarker for different forms of dementia. Serum Lp-PLA2 activity was assessed in older patients with mild cognitive impairment (MCI, n = 166; median clinical follow-up = 29 months), Late-Onset Alzheimer's disease (LOAD, n = 176), vascular dementia (VAD, n = 43), dementia characterized by an overlap between LOAD and VAD (AD-VAD MIXED dementia) (n = 136), other dementia subtypes (n = 45), and cognitively normal controls (n = 151). We found a significant trend towards higher levels of Lp-PLA2 activity in VAD compared with the other groups (ANOVA, p = 0.028). Similarly, Lp-PLA2 activity was greater in MCI converting to VAD compared with those that did not or did convert to the other types of dementia (ANOVA, p = 0.011). After adjusting for potential confounders, high levels of Lp-PLA2 activity were associated with the diagnosis of VAD (O.R. = 2.38, 95% C.I. = 1.06-5.10), but not with other types of dementia. Our data suggest that increased serum Lp-PLA2 activity may represent a potential biomarker for the diagnosis of VAD.
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Affiliation(s)
- Giovanni Zuliani
- Department of Translational Medicine and for Romagna, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Judit Marsillach
- Department of Environmental & Occupational Health Sciences, University of Washington, 4225 NE Roosevelt Way, Seattle, WA 98105, USA
| | - Alessandro Trentini
- Department of Environmental and Prevention Sciences, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Valentina Rosta
- Department of Translational Medicine and for Romagna, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Carlo Cervellati
- Department of Translational Medicine and for Romagna, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
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Malone JE, Elkasaby MI, Lerner AJ. Effects of Hypertension on Alzheimer's Disease and Related Disorders. Curr Hypertens Rep 2022; 24:615-625. [PMID: 36125695 DOI: 10.1007/s11906-022-01221-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2022] [Indexed: 01/31/2023]
Abstract
PURPOSE OF REVIEW To review the pathophysiology of hypertension in Alzheimer's disease and related dementias and explore the current landscape of clinical trials involving treatment of hypertension to improve cognition. RECENT FINDINGS Hypertension is increasingly recognized as a contributor to cognitive impairment. Clinical trials that explore blood pressure reductions with cognitive outcomes have been promising. Various antihypertensives have been evaluated in clinical trials, with growing interest in those agents that impact the renin-angiotensin-aldosterone system due to its own association with cognitive impairment. No antihypertensive agent has been found to be superior to others in reducing cognitive impairment risk or conferring neuroprotective benefits. In this review, the pathophysiology of and clinical trial data involving hypertension and dementia will be explored. Hypertension is a significant risk factor for the development of neurodegenerative dementias, and clinical trials have been overall favorable in improving cognition by reductions in blood pressure using antihypertensive agents.
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Affiliation(s)
- Joseph E Malone
- Department of Neurology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Mohamed I Elkasaby
- Department of Neurology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Alan J Lerner
- Department of Neurology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.
- Case Western Reserve University School of Medicine, Cleveland, OH, USA.
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Taylor HA, Simmons KJ, Clavane EM, Trevelyan CJ, Brown JM, Przemyłska L, Watt NT, Matthews LC, Meakin PJ. PTPRD and DCC Are Novel BACE1 Substrates Differentially Expressed in Alzheimer's Disease: A Data Mining and Bioinformatics Study. Int J Mol Sci 2022; 23:ijms23094568. [PMID: 35562959 PMCID: PMC9103286 DOI: 10.3390/ijms23094568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/15/2022] [Accepted: 04/18/2022] [Indexed: 02/04/2023] Open
Abstract
The β-site Amyloid precursor protein Cleaving Enzyme 1 (BACE1) is an extensively studied therapeutic target for Alzheimer's disease (AD), owing to its role in the production of neurotoxic amyloid beta (Aβ) peptides. However, despite numerous BACE1 inhibitors entering clinical trials, none have successfully improved AD pathogenesis, despite effectively lowering Aβ concentrations. This can, in part, be attributed to an incomplete understanding of BACE1, including its physiological functions and substrate specificity. We propose that BACE1 has additional important physiological functions, mediated through substrates still to be identified. Thus, to address this, we computationally analysed a list of 533 BACE1 dependent proteins, identified from the literature, for potential BACE1 substrates, and compared them against proteins differentially expressed in AD. We identified 15 novel BACE1 substrates that were specifically altered in AD. To confirm our analysis, we validated Protein tyrosine phosphatase receptor type D (PTPRD) and Netrin receptor DCC (DCC) using Western blotting. These findings shed light on the BACE1 inhibitor failings and could enable the design of substrate-specific inhibitors to target alternative BACE1 substrates. Furthermore, it gives us a greater understanding of the roles of BACE1 and its dysfunction in AD.
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Affiliation(s)
- Hannah A. Taylor
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
| | - Katie J. Simmons
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
| | - Eva M. Clavane
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
| | - Christopher J. Trevelyan
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
| | - Jane M. Brown
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
| | - Lena Przemyłska
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
| | - Nicole T. Watt
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
| | - Laura C. Matthews
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK;
| | - Paul J. Meakin
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK; (H.A.T.); (K.J.S.); (E.M.C.); (C.J.T.); (J.M.B.); (L.P.); (N.T.W.)
- Correspondence:
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Mao M, Yang L, Jin Z, Li LX, Wang YR, Li TT, Zhao YJ, Ai J. Impact of intrauterine hypoxia on adolescent and adult cognitive function in rat offspring: sexual differences and the effects of spermidine intervention. Acta Pharmacol Sin 2021; 42:361-369. [PMID: 32694754 PMCID: PMC8027377 DOI: 10.1038/s41401-020-0437-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/09/2020] [Indexed: 12/21/2022] Open
Abstract
Intrauterine hypoxia (IUH) affects the growth and development of offspring. It remains unclear that how long the impact of IUH on cognitive function lasts and whether sexual differences exist. Spermidine (SPD) has shown to improve cognition, but its effect on the cognitive function of IUH offspring remains unknown. In the present study we investigated the influence of IUH on body weight and neurological, motor and cognitive function and the expression of APP, BACE1 and Tau5 proteins in brain tissues in 2- and 4-month-old IUH rat offspring, as well as the effects of SPD intervention on these parameters. IUH rat model was established by treating pregnant rats with intermittent hypoxia on gestational days 15-21, meanwhile pregnant rats were administered SPD (5 mg·kg-1·d-1;ip) for 7 days. Neurological deficits were assessed in the Longa scoring test; motor and cognitive functions were evaluated in coat hanger test and active avoidance test, respectively. We found that IUH decreased the body weight of rats in both sexes but merely impaired motor and cognitive function in female rats without changing neurological function in the rat offspring of either sex at 2 months of age. For 4-month-old offspring, IUH decreased body weight in males and impaired neurological function and increased cognitive function in both sexes. IUH did not affect APP, BACE1 or Tau5 protein expression in either the hippocampus or cortex of all offspring; however, it increased the cortical Tau5 level in 2-month-old female offspring. Surprisingly, SPD intervention prevented weight loss. SPD intervention reversed the motor and cognitive decline caused by IUH in 2-month-old female rat offspring. Taken together, IUH-induced cognitive decline in rat offspring is sex-dependent during puberty and can be recovered in adult rats. SPD intervention improves IUH-induced cognitive and neural function decline.
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Affiliation(s)
- Meng Mao
- Department of Pharmacology, College of Pharmacy of Harbin Medical University (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, 150086, China
| | - Lin Yang
- Department of Pharmacology, College of Pharmacy of Harbin Medical University (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, 150086, China
| | - Zhuo Jin
- Department of Pharmacology, College of Pharmacy of Harbin Medical University (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, 150086, China
| | - Ling-Xu Li
- Department of Pathophysiology, Harbin Medical University, Harbin, 150086, China
| | - Yan-Ru Wang
- Department of Pharmacology, College of Pharmacy of Harbin Medical University (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, 150086, China
| | - Ting-Ting Li
- Department of Pharmacology, College of Pharmacy of Harbin Medical University (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, 150086, China
| | - Ya-Jun Zhao
- Department of Pathophysiology, Harbin Medical University, Harbin, 150086, China.
| | - Jing Ai
- Department of Pharmacology, College of Pharmacy of Harbin Medical University (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin, 150086, China.
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Xu Y, Zhang S, Sun Q, Wang XQ, Chai YN, Mishra C, Chandra SR, Ai J. Cholinergic Dysfunction Involvement in Chronic Cerebral Hypoperfusion-Induced Impairment of Medial Septum-dCA1 Neurocircuit in Rats. Front Cell Neurosci 2020; 14:586591. [PMID: 33132852 PMCID: PMC7550820 DOI: 10.3389/fncel.2020.586591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 08/31/2020] [Indexed: 11/13/2022] Open
Abstract
Chronic cerebral hypoperfusion (CCH) is considered a preclinical condition of mild cognitive impairment and thought to precede dementia. However, as the principal cholinergic source of hippocampus, whether the septo-hippocampal neurocircuit was impaired after CCH is still unknown. In this study, we established the CCH rat model by bilateral common carotid artery occlusion (2VO). Under anesthesia, the medial septum (MS) of rats was stimulated to evoke the field excitatory post-synaptic potential (fEPSP) in the pyramidal cell layer of dCA1. Consequently, we observed decreased amplitude of fEPSP and increased paired-pulse ratio (PPR) after 8-week CCH. After tail pinch, we also found decreased peak frequency and shortened duration of hippocampal theta rhythm in 2VO rats, indicating the dysfunction of septo-hippocampal neurocircuit. Besides, by intracerebroventricularly injecting GABAergic inhibitor (bicuculline) and cholinergic inhibitors (scopolamine and mecamylamine), we found that CCH impaired both the pre-synaptic cholinergic release and the post-synaptic nAChR function in MS-dCA1 circuits. These results gave an insight into the role of CCH in the impairment of cholinergic MS-dCA1 neurocircuits. These findings may provide a new idea about the CCH-induced neurodegenerative changes.
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Affiliation(s)
- Yi Xu
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
| | - Shuai Zhang
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
| | - Qiang Sun
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
| | - Xu-Qiao Wang
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
| | - Ya-Ni Chai
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
| | - Chandan Mishra
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
| | - Shah Ram Chandra
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
| | - Jing Ai
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin, China
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Increased blood BACE1 activity as a potential common pathogenic factor of vascular dementia and late onset Alzheimer's disease. Sci Rep 2020; 10:14980. [PMID: 32917964 PMCID: PMC7486910 DOI: 10.1038/s41598-020-72168-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/27/2020] [Indexed: 11/08/2022] Open
Abstract
Late onset Alzheimer disease (LOAD) is traditionally considered as a separate disease from vascular dementia (VAD). However, growing evidence suggests that β-amyloid (Aβ) accumulation, that initiates LOAD-related neurodegeneration, is preceded by vascular events. Previous in vitro studies showed that β-secretase 1 (BACE1), the key-enzyme of amyloidogenesis, is upregulated by cerebrovascular insult; moreover, its activity is increased both in brain and serum of LOAD patients. We aimed to investigate whether BACE1 serum activity is altered also in dementias related, or not, to cerebrovascular disease. Thus, we evaluated serum BACE1 activity in a sample of individuals, including patients with LOAD (n. 175), VAD (n. 40), MIXED (LOAD/VAD) dementia (n. 123), other types of dementia (n. 56), and healthy Controls (n. 204). We found that BACE1 was significantly higher not only in LOAD (+ 30%), but also in VAD (+ 35%) and MIXED dementia (+ 22%) (p < 0.001 for all), but not in the other types of dementia (+ 10%). Diagnostic accuracy was 77% for LOAD, 83% for VAD, and 77% for MIXED dementia. In conclusion, we showed for the first time that the increase in peripheral BACE1 activity is a common feature of LOAD and VAD, thus underlying a further pathogenic link between these two forms of dementia.
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7
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An Overview of Non-coding RNAs and Cardiovascular System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1229:3-45. [PMID: 32285403 DOI: 10.1007/978-981-15-1671-9_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cardiovascular disease management and timely diagnosis remain a major dilemma. Delineating molecular mechanisms of cardiovascular diseases is opening horizon in the field of molecular medicines and in the development of early diagnostic markers. Non-coding RNAs are the highly functional and vibrant nucleic acids and are known to be involved in the regulation of endothelial cells, vascular and smooth muscles cells, cardiac metabolism, ischemia, inflammation and many processes in cardiovascular system. This chapter is comprehensively focusing on the overview of the non-coding RNAs including their discovery, generation, classification and functional regulation. In addition, overview regarding different non-coding RNAs as long non-coding, siRNAs and miRNAs involvement in the cardiovascular diseases is also addressed. Detailed functional analysis of this vast group of highly regulatory molecules will be promising for shaping future drug discoveries.
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Abstract
SIGNIFICANCE To maintain homeostasis, gene expression has to be tightly regulated by complex and multiple mechanisms occurring at the epigenetic, transcriptional, and post-transcriptional levels. One crucial regulatory component is represented by long noncoding RNAs (lncRNAs), nonprotein-coding RNA species implicated in all of these levels. Thus, lncRNAs have been associated with any given process or pathway of interest in a variety of systems, including the heart. Recent Advances: Mounting evidence implicates lncRNAs in cardiovascular diseases (CVD) and progression and their presence in the blood of heart disease patients indicates that they are attractive potential biomarkers. CRITICAL ISSUES Our understanding of the regulation and molecular mechanisms of action of most lncRNAs remains rudimentary. A challenge is represented by their often low evolutionary sequence conservation that limits the use of animal models for preclinical studies. Nevertheless, a growing number of lncRNAs with an impact on heart function is rapidly accumulating. In this study, we will discuss (i) lncRNAs that control heart homeostasis and disease; (ii) concepts, approaches, and methodologies necessary to study lncRNAs in the heart; and (iii) challenges posed and opportunities presented by lncRNAs as potential therapeutic targets and biomarkers. FUTURE DIRECTIONS A deeper knowledge of the molecular mechanisms underpinning CVDs is necessary to develop more effective treatments. Further studies are needed to clarify the regulation and function of lncRNAs in the heart before they can be considered as therapeutic targets and disease biomarkers. Antioxid. Redox Signal. 29, 880-901.
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Affiliation(s)
- Simona Greco
- 1 Molecular Cardiology Laboratory, IRCCS Policlinico San Donato , Milan, Italy
| | - Antonio Salgado Somoza
- 2 Cardiovascular Research Unit, Luxembourg Institute of Health (LIH) , Luxembourg, Luxembourg
| | - Yvan Devaux
- 2 Cardiovascular Research Unit, Luxembourg Institute of Health (LIH) , Luxembourg, Luxembourg
| | - Fabio Martelli
- 1 Molecular Cardiology Laboratory, IRCCS Policlinico San Donato , Milan, Italy
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Qin X, Wang Y, Paudel HK. Inhibition of Early Growth Response 1 in the Hippocampus Alleviates Neuropathology and Improves Cognition in an Alzheimer Model with Plaques and Tangles. THE AMERICAN JOURNAL OF PATHOLOGY 2017. [PMID: 28641077 DOI: 10.1016/j.ajpath.2017.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A sporadic form of Alzheimer disease (AD) and vascular dementia share many risk factors, and their pathogenic mechanisms are suggested to be related. Transcription factor early growth response 1 (Egr-1) regulates various vascular pathologies and is up-regulated in both AD brains and AD mouse models; however, its role in AD pathogenesis is unclear. Herein, we report that silencing of Egr-1 in the hippocampus by shRNA reduces tau phosphorylation, lowers amyloid-β (Aβ) pathology, and improves cognition in the 3xTg-AD mouse model. Egr-1 silencing does not affect levels of cyclin-dependent protein kinase 5 (Cdk5), glycogen synthase kinase 3β, protein phosphatase 1, or protein phosphatase 2A, but reduces p35 subunit of Cdk5. Egr-1 silencing also reduces levels of β-secretase 1 (BACE-1) and BACE-1-cleaved amyloid precursor protein (APP) metabolites (secreted APPβ, C99, Aβ40, and Aβ42) but has no effect on presenilin 1 and presenilin 2. In hippocampal primary neurons, Egr-1 binds to BACE-1 and p35 promoters, enhances tau phosphorylation, activates Cdk5 and BACE-1, and accelerates amyloidogenic APP processing. Blocking Cdk5 action blocks Egr-1-induced tau phosphorylation but has no effect on BACE-1 activation and amyloidogenic APP processing. Blocking BACE-1 action, on the other hand, blocks Egr-1-induced amyloidogenic APP processing but does not affect tau phosphorylation. Egr-1 regulates tau phosphorylation and Aβ synthesis in the brain by respectively controlling activities of Cdk5 and BACE-1, suggesting that Egr-1 is a potential therapeutic candidate for the treatment of AD.
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Affiliation(s)
- Xike Qin
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Yunling Wang
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Hemant K Paudel
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec, Canada.
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Muche A, Arendt T, Schliebs R. Oxidative stress affects processing of amyloid precursor protein in vascular endothelial cells. PLoS One 2017; 12:e0178127. [PMID: 28617802 PMCID: PMC5472258 DOI: 10.1371/journal.pone.0178127] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/09/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Oxidative stress is thought to be a key player in the pathogenesis of neurodegenerative dementia, including Alzheimer's disease (AD). It has been assumed that oxidative stress contributes to the ß-amyloid deposition in cerebral blood vessels. METHODS In order to prove this hypothesis, we examined the effect of oxidative stress on the processing of amyloid precursor protein (APP) in primary endothelial cells (EC) derived from cerebral cortical tissue of transgenic Tg2576 mice. Following exposure of EC by 1 μM hydrogen peroxide for up to 48 hours, formation and secretion of APP cleavage products sAPPα and sAPPß into the culture medium as well as the expression of endothelial APP were assessed. RESULTS Oxidative stress resulted in enhanced secretion of sAPPß into the culture medium as compared to controls (absence of hydrogen peroxide), which was accompanied by an increased APP expression, induction of VEGF synthesis, nitric oxide and oxygen free radicals productions, and differential changes of endothelial phospo-p42/44 MAPK expression. CONCLUSION The data suggest that oxidative stress may represent a major risk factor in causing Aß deposition in the brain vascular system by initiating the amyloidogenic route of endothelial APP processing. The enhanced β-secretase activity following oxidative stress exposure, possibly promoted by phosphorylation of p42/44 MAPK.
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Affiliation(s)
- Abebe Muche
- Department of Human Anatomy, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
- * E-mail:
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Reinhard Schliebs
- Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
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Chen X, Jiang XM, Zhao LJ, Sun LL, Yan ML, Tian Y, Zhang S, Duan MJ, Zhao HM, Li WR, Hao YY, Wang LB, Xiong QJ, Ai J. MicroRNA-195 prevents dendritic degeneration and neuron death in rats following chronic brain hypoperfusion. Cell Death Dis 2017; 8:e2850. [PMID: 28569780 PMCID: PMC5520902 DOI: 10.1038/cddis.2017.243] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/16/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023]
Abstract
Impaired synaptic plasticity and neuron loss are hallmarks of Alzheimer’s disease and vascular dementia. Here, we found that chronic brain hypoperfusion (CBH) by bilateral common carotid artery occlusion (2VO) decreased the total length, numbers and crossings of dendrites and caused neuron death in rat hippocampi and cortices. It also led to increase in N-terminalβ-amyloid precursor protein (N-APP) and death receptor-6 (DR6) protein levels and in the activation of caspase-3 and caspase-6. Further study showed that DR6 protein was downregulated bymiR-195overexpression, upregulated bymiR-195inhibition, and unchanged by binding-site mutation and miR-masks. Knockdown of endogenousmiR-195by lentiviral vector-mediated overexpression of its antisense molecule (lenti-pre-AMO-miR-195) decreased the total length, numbers and crossings of dendrites and neuron death, upregulated N-APP and DR6 levels, and elevated cleaved caspase-3 and caspase-6 levels. Overexpression ofmiR-195using lenti-pre-miR-195prevented these changes triggered by 2VO. We conclude thatmiR-195is involved in CBH-induced dendritic degeneration and neuron death through activation of the N-APP/DR6/caspase pathway.
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Affiliation(s)
- Xin Chen
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China.,Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, China
| | - Xue-Mei Jiang
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Lin-Jing Zhao
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Lin-Lin Sun
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Mei-Ling Yan
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - You Tian
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Shuai Zhang
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Ming-Jing Duan
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Hong-Mei Zhao
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Wen-Rui Li
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Yang-Yang Hao
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Li-Bo Wang
- Department of Medicinal Chemistry and Natural Medicine Chemistry, College of Pharmacy of Harbin Medical University, Harbin 150086, China
| | - Qiao-Jie Xiong
- Department of Neurobiology and Behavior, SUNY at Stony Brook, Stony Brook, NY 1794, USA
| | - Jing Ai
- Department of Pharmacology, The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, College of Pharmacy of Harbin Medical University, Harbin 150086, China
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Greco S, Zaccagnini G, Fuschi P, Voellenkle C, Carrara M, Sadeghi I, Bearzi C, Maimone B, Castelvecchio S, Stellos K, Gaetano C, Menicanti L, Martelli F. Increased BACE1-AS long noncoding RNA and β-amyloid levels in heart failure. Cardiovasc Res 2017; 113:453-463. [DOI: 10.1093/cvr/cvx013] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 01/25/2017] [Indexed: 01/18/2023] Open
Affiliation(s)
- Simona Greco
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
| | - Germana Zaccagnini
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
| | - Paola Fuschi
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
| | - Christine Voellenkle
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
| | - Matteo Carrara
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
| | - Iman Sadeghi
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
| | - Claudia Bearzi
- Institute of Cell Biology and Neurobiology (IBCN), National Research Council of Italy (CNR), Monterotondo Scalo, Rome, Italy
| | - Biagina Maimone
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
| | | | - Konstantinos Stellos
- Laboratory of RNA Metabolism and Vascular Inflammation, Institute of Cardiovascular Regeneration, Centre of Molecular Medicine, Goethe University Frankfurt, Frankfurt/Main, Germany
| | - Carlo Gaetano
- Division of Cardiovascular Epigenetics, Department of Cardiology and Internal Medicine Clinic III, Department of Cardiology, Goethe University, Frankfurt/Main, Germany
| | - Lorenzo Menicanti
- Department of Cardiac Surgery, IRCCS Policlinico San Donato, Milan, Italy
| | - Fabio Martelli
- Molecular Cardiology Laboratory, IRCCS Policlinico San Donato, Via Morandi, 30 20097 San Donato, Milanese, Milan, Italy
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Zhao HY, Wu HJ, He JL, Zhuang JH, Liu ZY, Huang LQ, Zhao ZX. Chronic Sleep Restriction Induces Cognitive Deficits and Cortical Beta-Amyloid Deposition in Mice via BACE1-Antisense Activation. CNS Neurosci Ther 2017; 23:233-240. [PMID: 28145081 DOI: 10.1111/cns.12667] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 11/27/2016] [Accepted: 11/29/2016] [Indexed: 12/11/2022] Open
Abstract
AIMS To clarify the correlation between chronic sleep restriction (CSR) and sporadic Alzheimer disease (AD), we determined in wild-type mice the impact of CSR, on cognitive performance, beta-amyloid (Aβ) peptides, and its feed-forward regulators regarding AD pathogenesis. METHODS Sixteen nine-month-old C57BL/6 male mice were equally divided into the CSR and control groups. CSR was achieved by application of a slowly rotating drum for 2 months. The Morris water maze test was used to assess cognitive impairment. The concentrations of Aβ peptides, amyloid precursor protein (APP) and β-secretase 1 (BACE1), and the mRNA levels of BACE1 and BACE1-antisense (BACE1-AS) were measured. RESULTS Following CSR, impairments of spatial learning and memory consolidation were observed in the mice, accompanied by Aβ plaque deposition and an increased Aβ concentration in the prefrontal and temporal lobe cortex. CSR also upregulated the β-secretase-induced cleavage of APP by increasing the protein and mRNA levels of BACE1, particularly the BACE1-AS. CONCLUSIONS This study shows that a CSR accelerates AD pathogenesis in wild-type mice. An upregulation of the BACE1 pathway appears to participate in both cortical Aβ plaque deposition and memory impairment caused by CSR. BACE1-AS is likely activated to initiate a cascade of events that lead to AD pathogenesis. Our study provides, therefore, a molecular mechanism that links CSR to sporadic AD.
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Affiliation(s)
- Hong-Yi Zhao
- Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Hui-Juan Wu
- Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Jia-Lin He
- Academy of Clinical Medicine, Second Military Medical University, Shanghai, China
| | - Jian-Hua Zhuang
- Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Zhen-Yu Liu
- Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Liu-Qing Huang
- Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Zhong-Xin Zhao
- Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai, China
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Knockdown of microRNA-195 contributes to protein phosphatase-2A inactivation in rats with chronic brain hypoperfusion. Neurobiol Aging 2016; 45:76-87. [DOI: 10.1016/j.neurobiolaging.2016.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/25/2016] [Accepted: 05/10/2016] [Indexed: 12/26/2022]
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Qin X, Wang Y, Paudel HK. Early Growth Response 1 (Egr-1) Is a Transcriptional Activator of β-Secretase 1 (BACE-1) in the Brain. J Biol Chem 2016; 291:22276-22287. [PMID: 27576688 DOI: 10.1074/jbc.m116.738849] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Indexed: 11/06/2022] Open
Abstract
Accumulation of amyloid-β peptide (Aβ) in the brain is regarded as central to Alzheimer's disease (AD) pathogenesis. Aβ is generated by a sequential cleavage of amyloid precursor protein (APP) by β-secretase 1 (BACE-1) followed by γ-secretase. BACE-1 cleavage of APP is the committed step in Aβ synthesis. Understanding the mechanism by which BACE-1 is activated leading to Aβ synthesis in the brain can provide better understanding of AD pathology and help to develop novel therapies. In this study, we found that the levels of Aβ and BACE-1 are significantly reduced in the brains of mice lacking transcription factor early growth response 1 (Egr-1) when compared with the WT. We demonstrate that in COS-7 cells, Egr-1 binds to the BACE-1 promoter and activates BACE-1 transcription. In rat hippocampal primary neurons, overexpression of Egr-1 induces BACE-1 expression, activates BACE-1, promotes amyloidogenic APP processing, and enhances Aβ synthesis. In mouse hippocampal primary neurons, knockdown of BACE-1 almost completely blocks Egr-1-induced amyloidogenic APP processing and Aβ synthesis. Our data indicate that Egr-1 promotes Aβ synthesis via transcriptional activation of BACE-1 and suggest that Egr-1 plays role in activation of BACE-1 and acceleration of Aβ synthesis in AD brain. Egr-1 is a potential therapeutic target for AD.
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Affiliation(s)
- Xike Qin
- From the Lady Davis Institute for Medical Research, Jewish General Hospital, and
| | - Yunling Wang
- From the Lady Davis Institute for Medical Research, Jewish General Hospital, and
| | - Hemant K Paudel
- From the Lady Davis Institute for Medical Research, Jewish General Hospital, and the Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec H4H 1R3, Canada
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16
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Sun LH, Ban T, Liu CD, Chen QX, Wang X, Yan ML, Hu XL, Su XL, Bao YN, Sun LL, Zhao LJ, Pei SC, Jiang XM, Zong DK, Ai J. Activation of Cdk5/p25 and tau phosphorylation following chronic brain hypoperfusion in rats involves microRNA-195 down-regulation. J Neurochem 2015; 134:1139-51. [PMID: 26118667 DOI: 10.1111/jnc.13212] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 11/27/2022]
Abstract
Chronic brain hypoperfusion (CBH) is a common clinical feature of Alzheimer's disease and vascular dementia, but the underlying molecular mechanism is unclear. Our previous study reported that the down-regulation of microRNA-195 (miR-195) promotes amyloidogenesis via regulation of amyloid precursor protein and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) expression at the post-transcriptional level in CBH rats with bilateral common carotid artery occlusion (2VO). CBH owing to unilateral common carotid artery occlusion (UCCAO) increases tau phosphorylation levels at multiple phosphorylation sites in the brain, but the molecular mechanism is poorly understood. The purpose of this study was to investigate whether miR-195 could both deregulate amyloid metabolism and indirectly deregulate tau phosphorylation in CBH. We observed that 2VO leads to tau hyperphosphorylation at Ser202/Thr205, Ser262, Thr231, and Ser422 and to the conversion from cyclin-dependent kinase 5 (Cdk5)/p35 to Cdk5/p25 in rat hippocampi. Endogenous miR-195 was knocked down using over-expression of its antisense molecule (pre-AMO-miR-195) via a lentivirus (lenti-pre-AMO-miR-195); this knockdown increased the tau phosphorylation at Ser202/Thr205, Ser262, Thr231, Ser422, and the Cdk5/p25 activation, but over-expression of miR-195 using lenti-pre-miR-195 decreased the tau phosphorylation and Cdk5/p25 activation. Further in vitro studies demonstrated that miR-195 over-expression prevented tau hyperphosphorylation and Cdk5/p35 activity, which were increased by miR-195 inhibition. A dual luciferase reporter assay showed that miR-195 bound to the Cdk5r1 gene, which encodes p35 protein, in the 3'UTR and inhibited p35 expression. We concluded that tau hyperphosphorylation involves the down-regulation of miR-195, which is mediated by Cdk5/p25 activation in 2VO rats. Our findings demonstrated that down-regulation of miR-195 led to increased vulnerability via the regulation of multiple targets. Schematic diagram of miR-195 mediated Aβ aggregation and tau hyperphosphorylation in chronic brain hypoperfusion (CBH). First, CBH results in the elevation of nuclear factor-κB (NF-κB), which binds with the promoter sequences of miR-195 and negatively regulates the expression of miR-195. Second, down-regulated miR-195 induces up-regulation of APP and BACE1 and leads to an increase in Aβ levels. Third, some of the elevated Aβ then enter the intracellular space and activate calpain, which promotes the conversion of Cdk5/p35 to Cdk5/p25 and catalyzes the degradation of IκB; IκB is an inhibitor of NF-κB, which activates NF-κB. Cdk5/p25 directly phosphorylates Tau. Fourth, down-regulated miR-195 induces an up-regulation of p35, which provides the active substrates of p25. Our findings demonstrated that the down-regulation of miR-195 plays a key role in the increased vulnerability to dementia via the regulation of multiple targets following CBH.
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Affiliation(s)
- Li-Hua Sun
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Tao Ban
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Cheng-Di Liu
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Qing-Xin Chen
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xu Wang
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Mei-Ling Yan
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xue-Ling Hu
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xiao-Lin Su
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Ya-Nan Bao
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Lin-Lin Sun
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Lin-Jing Zhao
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Shuang-Chao Pei
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xue-Mei Jiang
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - De-Kang Zong
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Jing Ai
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
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Icariin, a major constituent of flavonoids from Epimedium brevicornum, protects against cognitive deficits induced by chronic brain hypoperfusion via its anti-amyloidogenic effect in rats. Pharmacol Biochem Behav 2015; 138:40-8. [DOI: 10.1016/j.pbb.2015.09.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 09/02/2015] [Accepted: 09/04/2015] [Indexed: 11/20/2022]
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18
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Sood S, Jain K, Gowthamarajan K. Intranasal therapeutic strategies for management of Alzheimer's disease. J Drug Target 2014; 22:279-94. [PMID: 24404923 DOI: 10.3109/1061186x.2013.876644] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is a chronic and progressive age-related irreversible neurodegenerative disorder that represents 70% of all dementia with 35 million cases worldwide. Successful treatment strategies for AD have so far been limited, and present therapy is based on cholinergic replacement therapy and inhibiting glutamate excitotoxicity. In this context, role of neuroprotective drugs has generated considerable interest in management of AD. Recently, direct intranasal (IN) delivery of drug moieties to the central nervous system (CNS) has emerged as a therapeutically viable alternative to oral and parenteral routes. IN delivery bypasses the blood-brain barrier by delivering and targeting drugs to the CNS along the olfactory and trigeminal neural pathways which are in direct contact with both the environment and the CNS. In an attempt to understand how neurotherapeutics/nanoparticulate delivery systems can be transported from the nose to the CNS, the present review sets out to discuss the mechanism of transport from nose to brain. The aim of this review is to discuss and summarize the latest findings of some of the major studies on IN drug delivery in AD models, with a focus on the potential efficacy of neuroprotective treatments.
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Affiliation(s)
- Sumeet Sood
- Department of Pharmaceutics, J.S.S. College of Pharmacy , Udhagamandalam, Tamil Nadu , India
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19
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Muche A, Bürger S, Arendt T, Schliebs R. Hypoxic stress, brain vascular system, and β-amyloid: A primary cell culture study. Nutr Neurosci 2013; 18:1-11. [DOI: 10.1179/1476830513z.000000000112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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20
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Ai J, Sun LH, Che H, Zhang R, Zhang TZ, Wu WC, Su XL, Chen X, Yang G, Li K, Wang N, Ban T, Bao YN, Guo F, Niu HF, Zhu YL, Zhu XY, Zhao SG, Yang BF. MicroRNA-195 protects against dementia induced by chronic brain hypoperfusion via its anti-amyloidogenic effect in rats. J Neurosci 2013; 33:3989-4001. [PMID: 23447608 PMCID: PMC6619292 DOI: 10.1523/jneurosci.1997-12.2013] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 01/12/2013] [Accepted: 01/15/2013] [Indexed: 11/21/2022] Open
Abstract
Previous studies have demonstrated that chronic brain hypoperfusion (CBH) causes Aβ aggregation by upregulating expression of amyloid precursor protein (APP) and β-site APP cleaving enzyme 1 (BACE1) protein, which is accompanied by cognitive impairment, but the mechanisms are not fully understood. In this study, we evaluated the effect of microRNA on memory impairment in rats induced by CBH. We show here that CBH generated by bilateral common carotid artery occlusion (2VO) significantly decreased the learning and memory ability in rats, as assessed by Morris water maze, and upregulated expression of APP and BACE1 proteins in the hippocampus and cortex of rats, as evaluated by Western blot and immunofluorescence. In reciprocal, qRT-PCR analysis showed that microRNA-195 (miR-195) was downregulated in both the hippocampus and cortex of rats following CBH, and in the plasma of dementia patients. APP and BACE1 proteins were downregulated by miR-195 overexpression, upregulated by miR-195 inhibition, and unchanged by binding-site mutation or miR-masks, indicating that APP and BACE1 are two potential targets for miR-195. Knockdown of endogenous miR-195 by lentiviral vector-mediated overexpression of its antisense molecule (lenti-pre-AMO-miR-195) elicited dementia in rats, whereas overexpression of miR-195 using lenti-pre-miR-195 reduced dementia vulnerability triggered by 2VO. Additionally, chromatin immunoprecipitation analysis showed that NFκB was bound to the promoter region of miR-195 and inhibited its expression. We conclude that miR-195 may play a key role in determining dementia susceptibility in 2VO rats by regulating APP and BACE1 expression at the post-transcriptional level, and exogenous complement of miR-195 may be a potentially valuable anti-dementia approach.
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Affiliation(s)
- Jing Ai
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Li-Hua Sun
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Hui Che
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Rong Zhang
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Tian-Zhu Zhang
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Wan-Chen Wu
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Xiao-Lin Su
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Xin Chen
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
- Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China,150001
| | - Guang Yang
- Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China,150001
| | - Kang Li
- The Department of Biostatistics, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081; and
| | - Ning Wang
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Tao Ban
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Ya-Nan Bao
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Fei Guo
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | - Hui-Fang Niu
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
| | | | - Xiu-Ying Zhu
- Department of Gerontology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150086
| | - Shi-Guang Zhao
- Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China,150001
| | - Bao-Feng Yang
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China, 150081
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Nural-Guvener HF, Mutlu N, Gaballa MA. BACE1 levels are elevated in congestive heart failure. Neurosci Lett 2012; 532:7-11. [PMID: 23127855 DOI: 10.1016/j.neulet.2012.10.051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 09/11/2012] [Accepted: 10/17/2012] [Indexed: 11/28/2022]
Abstract
Cardiovascular (CV) diseases are known to have a negative impact on the brain and neurocognition, and contribute to the development of vascular dementia and neurodegenerative diseases such as Alzheimer's disease (AD). Among CV diseases, congestive heart failure (CHF) after myocardial infarction (MI) is a condition where the ability of the left ventricle to eject blood to the circulation is impaired. As a consequence, CHF triggers inflammation and results in reduced cerebral blood flow which are considered among the risk factors for development of AD. However, biochemical alterations in the brain following MI and CHF remain unknown. To address this issue, we investigated microglia activation; levels of BACE1, the key rate-limiting enzyme involved in the pathogenesis of AD; and VEGF levels in the hippocampus and cortex following MI. We created MI by the ligation of the left anterior descending coronary artery in Sprague-Dawley male rats and collected brains either 3 days after MI (AMI) or 21 days after MI (CHF). We investigated microglia activation in AMI and CHF brains by immunohistochemistry and immunoblotting using macrophage/microglia marker Ionized calcium binding adaptor molecule 1 (Iba-1), and observed activated morphology of microglia in the cortex of rats in both AMI and CHF. We also showed the levels of BACE1 were increased in the cortex and hippocampus of CHF rats. To determine whether hypoxia occurs in the CHF brain, we assessed levels of VEGF in the hippocampus and cortex. Western blotting analysis showed up-regulation of VEGF in the hippocampus of CHF brains. These results suggest that neuroinflammation takes place secondary to myocardial infarction. In addition, CHF-induced hypoxia might play a role in the elevation of BACE1 and VEGF levels.
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Affiliation(s)
- Hikmet F Nural-Guvener
- Center for Cardiovascular Research at Banner Sun Health Research Institute, Sun City, AZ, USA
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22
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Saxena S, Caroni P. Selective neuronal vulnerability in neurodegenerative diseases: from stressor thresholds to degeneration. Neuron 2011; 71:35-48. [PMID: 21745636 DOI: 10.1016/j.neuron.2011.06.031] [Citation(s) in RCA: 389] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2011] [Indexed: 12/12/2022]
Abstract
Neurodegenerative diseases selectively target subpopulations of neurons, leading to the progressive failure of defined brain systems, but the basis of such selective neuronal vulnerability has remained elusive. Here, we discuss how a stressor-threshold model of how particular neurons and circuits are selectively vulnerable to disease may underly the etiology of familial and sporadic forms of diseases such as Alzheimer's, Parkinson's, Huntington's, and ALS. According to this model, the intrinsic vulnerabilities of neuronal subpopulations to stressors and specific disease-related misfolding proteins determine neuronal morbidity. Neurodegenerative diseases then involve specific combinations of genetic predispositions and environmental stressors, triggering increasing age-related stress and proteostasis dysfunction in affected vulnerable neurons. Damage to vasculature, immune system, and local glial cells mediates environmental stress, which could drive disease at all stages.
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Affiliation(s)
- Smita Saxena
- Friedrich Miescher Institut, Novartis Research Foundation, CH-4058 Basel, Switzerland
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23
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Roher AE, Garami Z, Tyas SL, Maarouf CL, Kokjohn TA, Belohlavek M, Vedders LJ, Connor D, Sabbagh MN, Beach TG, Emmerling MR. Transcranial doppler ultrasound blood flow velocity and pulsatility index as systemic indicators for Alzheimer's disease. Alzheimers Dement 2011; 7:445-55. [PMID: 21388892 DOI: 10.1016/j.jalz.2010.09.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 06/30/2010] [Accepted: 09/21/2010] [Indexed: 12/17/2022]
Abstract
BACKGROUND Multiple lines of evidence suggest that cardiovascular co-morbidities hasten the onset of Alzheimer's disease (AD) or accelerate its course. METHODS To evaluate the utility of cerebral vascular physical function and/or condition parameters as potential systemic indicators of AD, transcranial Doppler (TCD) ultrasound was used to assess cerebral blood flow and vascular resistance of the 16 arterial segments comprising the circle of Willis and its major tributaries. RESULTS Our study showed that decreased arterial mean flow velocity and increased pulsatility index are associated with a clinical diagnosis of presumptive AD. Cerebral blood flow impairment shown by these parameters reflects the global hemodynamic and structural consequences of a multifaceted disease process yielding diffuse congestive microvascular pathology, increased arterial rigidity, and decreased arterial compliance, combined with putative age-associated cardiovascular output declines. CONCLUSIONS TCD evaluation offers direct physical confirmation of brain perfusion impairment and might ultimately provide a convenient and a noninvasive means to assess the efficacy of medical interventions on cerebral blood flow or reveal incipient AD. In the near term, TCD-based direct assessments of brain perfusion might offer the prospect of preventing or mitigating AD simply by revealing patients who would benefit from interventions to improve circulatory system function.
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Affiliation(s)
- Alex E Roher
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, AZ, USA.
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24
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Cai Y, Xiong K, Zhang XM, Cai H, Luo XG, Feng JC, Clough RW, Struble RG, Patrylo PR, Chu Y, Kordower JH, Yan XX. β-Secretase-1 elevation in aged monkey and Alzheimer's disease human cerebral cortex occurs around the vasculature in partnership with multisystem axon terminal pathogenesis and β-amyloid accumulation. Eur J Neurosci 2010; 32:1223-38. [PMID: 20726888 DOI: 10.1111/j.1460-9568.2010.07376.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is the most common dementia-causing disorder in the elderly; it may be related to multiple risk factors, and is characterized pathologically by cerebral hypometabolism, paravascular β-amyloid peptide (Aβ) plaques, neuritic dystrophy, and intra-neuronal aggregation of phosphorylated tau. To explore potential pathogenic links among some of these lesions, we examined β-secretase-1 (BACE1) alterations relative to Aβ deposition, neuritic pathology and vascular organization in aged monkey and AD human cerebral cortex. Western blot analyses detected increased levels of BACE1 protein and β-site-cleavage amyloid precursor protein C-terminal fragments in plaque-bearing human and monkey cortex relative to controls. In immunohistochemistry, locally elevated BACE1 immunoreactivity (IR) occurred in AD but not in control human cortex, with a trend for increased overall density among cases with greater plaque pathology. In double-labeling preparations, BACE1 IR colocalized with immunolabeling for Aβ but not for phosphorylated tau. In perfusion-fixed monkey cortex, locally increased BACE1 IR co-existed with intra-axonal and extracellular Aβ IR among virtually all neuritic plaques, ranging from primitive to typical cored forms. This BACE1 labeling localized to swollen/sprouting axon terminals that might co-express one or another neuronal phenotype markers (GABAergic, glutamatergic, cholinergic, or catecholaminergic). Importantly, these BACE1-labeled dystrophic axons resided near to or in direct contact with blood vessels. These findings suggest that plaque formation in AD or normal aged primates relates to a multisystem axonal pathogenesis that occurs in partnership with a potential vascular or metabolic deficit. The data provide a mechanistic explanation for why senile plaques are present preferentially near the cerebral vasculature.
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Affiliation(s)
- Yan Cai
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan, China
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Bürger S, Yafai Y, Bigl M, Wiedemann P, Schliebs R. Effect of VEGF and its receptor antagonist SU-5416, an inhibitor of angiogenesis, on processing of the β-amyloid precursor protein in primary neuronal cells derived from brain tissue of Tg2576 mice. Int J Dev Neurosci 2010; 28:597-604. [PMID: 20656006 DOI: 10.1016/j.ijdevneu.2010.07.231] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 07/12/2010] [Indexed: 10/19/2022] Open
Abstract
A large number of Alzheimer patients demonstrate cerebrovascular pathology, which has been assumed to be related to β-amyloid (Aβ) deposition. Aβ peptides have been described to inhibit angiogenesis both in vitro and in vivo, and deregulation of angiogenic factors may contribute to various neurological disorders including neurodegeneration. One of the key angiogenic factor is the vascular endothelial growth factor (VEGF). Increased levels of VEGF have been observed in brains of Alzheimer patients, while the functional significance of VEGF up-regulation in the pathogenesis and progression of AD is still a matter of debate. To test whether VEGF may affect neuronal APP processing, primary neuronal cells derived from brain tissue of E16 embryos of Tg2576 mice were exposed with 1 ng/ml VEGF for 6, 12, and 24h, followed by monitoring formation and secretion of soluble Aβ peptides, release of the human APP cleavage products, sAPPβswe and sAPPα, into the culture medium as well as the activities of α- and β-secretases in neuronal cell extracts. Exposure of primary neuronal cells by VEGF for 24h led to slightly reduced sAPPβ release, accompanied by decreased β-secretase activity 12h after VEGF exposure. Incubation of neurons by the VEGF receptor antagonist and angiogenesis inhibitor SU-5416 for 24h resulted in increased release of sAPPβswe, and strikingly enhanced secretion of Aβ peptides into the culture medium, which was accompanied by a significant increase in β-secretase activity, as compared to control incubations. The SU-5416-induced effects on APP processing could not be suppressed by the additional presence of VEGF, suggesting that SU-5416 affects pathways that are apparently independent of VEGF receptor signaling. The data obtained indicate that VEGF-driven mechanisms may affect APP processing, suggesting a link of angiogenesis and pathogenesis of Alzheimer's disease.
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Affiliation(s)
- Susanne Bürger
- Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Germany
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Bürger S, Noack M, Kirazov LP, Kirazov EP, Naydenov CL, Kouznetsova E, Yafai Y, Schliebs R. Vascular endothelial growth factor (VEGF) affects processing of amyloid precursor protein and beta-amyloidogenesis in brain slice cultures derived from transgenic Tg2576 mouse brain. Int J Dev Neurosci 2009; 27:517-23. [PMID: 19589380 DOI: 10.1016/j.ijdevneu.2009.06.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 06/12/2009] [Accepted: 06/30/2009] [Indexed: 12/13/2022] Open
Abstract
The up-regulation of the angiogenic vascular endothelial growth factor (VEGF) in brains of Alzheimer patients in close relationship to beta-amyloid (Abeta) plaques, suggests a link of VEGF action and processing of the amyloid precursor protein (APP). To reveal whether VEGF may affect APP processing, brain slices derived from 17-month-old transgenic Tg2576 mice were exposed with 1ng/ml VEGF for 6, 24, and 72h, followed by assessing cytosolic and membrane-bound APP expression, level of both soluble and fibrillar Abeta-peptides, as well as activities of alpha- and beta-secretases in brain slice tissue preparations. Treatment of brain slices with VEGF did not significantly affect the expression level of APP, regardless of the exposure time studied. In contrast, VEGF exposure of brain slices for 6h reduced the formation of soluble, SDS extractable Abeta(1-40) and Abeta(1-42) as compared to brain slice cultures incubated in the absence of any drug, while the fibrillar Abeta peptides did not change significantly. This effect was less pronounced 24h after VEGF exposure, but was no longer detectable when brain slices were exposed by VEGF for 72h, which indicates an adaptive response to chronic VEGF exposure. The VEGF-mediated reduction in Abeta formation was accompanied by a transient decrease in beta-secretase activity peaking 6h after VEGF exposure. To reveal whether the VEGF-induced changes in soluble Abeta-level may be due to actions of VEGF on Abeta fibrillogenesis, the fibrillar status of Abeta was examined using the thioflavin-T binding assay. Incubation of Abeta preparations obtained from Tg2576 mouse brain cortex, in the presence of VEGF slightly decreased the fibrillar content with increasing incubation time up to 72h. The data demonstrate that VEGF may affect APP processing, at least in vitro, suggesting a role of VEGF in the pathogenesis of Alzheimer's disease.
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Affiliation(s)
- Susanne Bürger
- Paul Flechsig Institute for Brain Research, University of Leipzig, Germany
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O'Connor T, Sadleir KR, Maus E, Velliquette RA, Zhao J, Cole SL, Eimer WA, Hitt B, Bembinster LA, Lammich S, Lichtenthaler SF, Hébert SS, De Strooper B, Haass C, Bennett DA, Vassar R. Phosphorylation of the translation initiation factor eIF2alpha increases BACE1 levels and promotes amyloidogenesis. Neuron 2009; 60:988-1009. [PMID: 19109907 DOI: 10.1016/j.neuron.2008.10.047] [Citation(s) in RCA: 327] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 09/16/2008] [Accepted: 10/17/2008] [Indexed: 10/21/2022]
Abstract
beta-site APP cleaving enzyme-1 (BACE1), the rate-limiting enzyme for beta-amyloid (Abeta) production, is elevated in Alzheimer's disease (AD). Here, we show that energy deprivation induces phosphorylation of the translation initiation factor eIF2alpha (eIF2alpha-P), which increases the translation of BACE1. Salubrinal, an inhibitor of eIF2alpha-P phosphatase PP1c, directly increases BACE1 and elevates Abeta production in primary neurons. Preventing eIF2alpha phosphorylation by transfection with constitutively active PP1c regulatory subunit, dominant-negative eIF2alpha kinase PERK, or PERK inhibitor P58(IPK) blocks the energy-deprivation-induced BACE1 increase. Furthermore, chronic treatment of aged Tg2576 mice with energy inhibitors increases levels of eIF2alpha-P, BACE1, Abeta, and amyloid plaques. Importantly, eIF2alpha-P and BACE1 are elevated in aggressive plaque-forming 5XFAD transgenic mice, and BACE1, eIF2alpha-P, and amyloid load are correlated in humans with AD. These results strongly suggest that eIF2alpha phosphorylation increases BACE1 levels and causes Abeta overproduction, which could be an early, initiating molecular mechanism in sporadic AD.
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Affiliation(s)
- Tracy O'Connor
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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