1
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Eccles MK, Main N, Carlessi R, Armstrong AM, Sabale M, Roberts-Mok B, Tirnitz-Parker JEE, Agostino M, Groth D, Fraser PE, Verdile G. Quantitative comparison of presenilin protein expression reveals greater activity of PS2-γ-secretase. FASEB J 2024; 38:e23396. [PMID: 38156414 DOI: 10.1096/fj.202300954rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 12/05/2023] [Accepted: 12/15/2023] [Indexed: 12/30/2023]
Abstract
γ-secretase processing of amyloid precursor protein (APP) has long been of interest in the pathological progression of Alzheimer's disease (AD) due to its role in the generation of amyloid-β. The catalytic component of the enzyme is the presenilins of which there are two homologues, Presenilin-1 (PS1) and Presenilin-2 (PS2). The field has focussed on the PS1 form of this enzyme, as it is typically considered the more active at APP processing. However, much of this work has been completed without appropriate consideration of the specific levels of protein expression of PS1 and PS2. We propose that expression is an important factor in PS1- and PS2-γ-secretase activity, and that when this is considered, PS1 does not have greater activity than PS2. We developed and validated tools for quantitative assessment of PS1 and PS2 protein expression levels to enable the direct comparison of PS in exogenous and endogenous expression systems, in HEK-293 PS1 and/or PS2 knockout cells. We show that exogenous expression of Myc-PS1-NTF is 5.5-times higher than Myc-PS2-NTF. Quantitating endogenous PS protein levels, using a novel PS1/2 fusion standard we developed, showed similar results. When the marked difference in PS1 and PS2 protein levels is considered, we show that compared to PS1-γ-secretase, PS2-γ-secretase has equal or more activity on APP and Notch1. This study has implications for understanding the PS1- and PS2-specific contributions to substrate processing, and their potential influence in AD pathogenesis.
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Affiliation(s)
- Melissa K Eccles
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - Nathan Main
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - Rodrigo Carlessi
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - Ayeisha Milligan Armstrong
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - Miheer Sabale
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Brigid Roberts-Mok
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - Janina E E Tirnitz-Parker
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - Mark Agostino
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - David Groth
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Giuseppe Verdile
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
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2
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Effectiveness of coenzyme Q10 on learning and memory and synaptic plasticity impairment in an aged Aβ-induced rat model of Alzheimer's disease: a behavioral, biochemical, and electrophysiological study. Psychopharmacology (Berl) 2023; 240:951-967. [PMID: 36811650 DOI: 10.1007/s00213-023-06338-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/06/2023] [Indexed: 02/24/2023]
Abstract
RATIONALE Aging is the major risk factor for Alzheimer's disease (AD), and cognitive and memory impairments are common among the elderly. Interestingly, coenzyme Q10 (Q10) levels decline in the brain of aging animals. Q10 is a substantial antioxidant substance, which has an important role in the mitochondria. OBJECTIVE We assessed the possible effects of Q10 on learning and memory and synaptic plasticity in aged β-amyloid (Aβ)-induced AD rats. METHODS In this study, 40 Wistar rats (24-36 months old; 360-450 g) were randomly assigned to four groups (n = 10 rats/group)-group I: control, group II: Aβ, group III: Q10; 50 mg/kg, and group IV: Q10+Aβ. Q10 was administered orally by gavage daily for 4 weeks before the Aβ injection. The cognitive function and learning and memory of the rats were measured by the novel object recognition (NOR), Morris water maze (MWM), and passive avoidance learning (PAL) tests. Finally, malondialdehyde (MDA), total antioxidant capacity (TAC), total thiol group (TTG), and total oxidant status (TOS) were measured. RESULTS Q10 improved the Aβ-related decrease in the discrimination index in the NOR test, spatial learning and memory in the MWM test, passive avoidance learning and memory in the PAL test, and long-term potentiation (LTP) impairment in the hippocampal PP-DG pathway in aged rats. In addition, Aβ injection significantly increased serum MDA and TOS levels. Q10, however, significantly reversed these parameters and also increased TAC and TTG levels in the Aβ+Q10 group. CONCLUSIONS Our experimental findings suggest that Q10 supplementation can suppress the progression of neurodegeneration that otherwise impairs learning and memory and reduces synaptic plasticity in our experimental animals. Therefore, similar supplemental Q10 treatment given to humans with AD could possibly provide them a better quality of life.
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3
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Alexander C, Li T, Hattori Y, Chiu D, Frost GR, Jonas L, Liu C, Anderson CJ, Wong E, Park L, Iadecola C, Li YM. Hypoxia Inducible Factor-1α binds and activates γ-secretase for Aβ production under hypoxia and cerebral hypoperfusion. Mol Psychiatry 2022; 27:4264-4273. [PMID: 35764706 PMCID: PMC9722522 DOI: 10.1038/s41380-022-01676-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 06/09/2022] [Accepted: 06/15/2022] [Indexed: 02/07/2023]
Abstract
Hypoxic-ischemic injury has been linked with increased risk for developing Alzheimer's disease (AD). The underlying mechanism of this association is poorly understood. Here, we report distinct roles for hypoxia-inducible factor-1α (Hif-1α) in the regulation of BACE1 and γ-secretase activity, two proteases involved in the production of amyloid-beta (Aβ). We have demonstrated that Hif-1α upregulates both BACE1 and γ-secretase activity for Aβ production in brain hypoxia-induced either by cerebral hypoperfusion or breathing 10% O2. Hif-1α binds to γ-secretase, which elevates the amount of active γ-secretase complex without affecting the level of individual subunits in hypoxic-ischemic mouse brains. Additionally, the expression of full length Hif-1α increases BACE1 and γ-secretase activity in primary neuronal culture, whereas a transcriptionally incompetent Hif-1α variant only activates γ-secretase. These findings indicate that Hif-1α transcriptionally upregulates BACE1 and nontranscriptionally activates γ-secretase for Aβ production in hypoxic-ischemic conditions. Consequently, Hif-1α-mediated Aβ production may be an adaptive response to hypoxic-ischemic injury, subsequently leading to increased risk for AD. Preventing the interaction of Hif-1α with γ-secretase may therefore be a promising therapeutic strategy for AD treatment.
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Affiliation(s)
- Courtney Alexander
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Thomas Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Yorito Hattori
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Danica Chiu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Georgia R Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Lauren Jonas
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Chenge Liu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Corey J Anderson
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Laibaik Park
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Costantino Iadecola
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA.
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA.
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4
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Wong E, Frost GR, Li YM. γ-Secretase Modulatory Proteins: The Guiding Hand Behind the Running Scissors. Front Aging Neurosci 2020; 12:614690. [PMID: 33343338 PMCID: PMC7738330 DOI: 10.3389/fnagi.2020.614690] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/10/2020] [Indexed: 12/16/2022] Open
Abstract
Described as the "proteasome of the membrane" or the "scissors in the membrane," γ-secretase has notoriously complicated biology, and even after decades of research, the full extent of its regulatory mechanism remains unclear. γ-Secretase is an intramembrane aspartyl protease complex composed of four obligatory subunits: Nicastrin (NCT), Presenilin (PS), Presenilin Enhancer-2 (Pen-2), and Anterior pharynx-defective-1 (Aph-1). γ-Secretase cleaves numerous type 1 transmembrane substrates, with no apparent homology, and plays major roles in broad biological pathways such as development, neurogenesis, and cancer. Notch and the amyloid precursor protein (APP) and are undoubtedly the best-studied γ-secretase substrates because of their role in cancer and Alzheimer's disease (AD) and therefore became the focus of increasing studies as an attractive therapeutic target. The regulation of γ-secretase is intricate and involves the function of multiple cellular entities. Recently, γ-secretase modulatory proteins (GSMPs), which are non-essential subunits and yet modulate γ-secretase activity and specificity, have emerged as an important component in guiding γ-secretase. GSMPs are responsive to cellular and environmental changes and therefore, provide another layer of regulation of γ-secretase. This type of enzymatic regulation allows for a rapid and fine-tuning of γ-secretase activity when appropriate signals appear enabling a temporal level of regulation. In this review article, we discuss the latest developments on GSMPs and implications on the development of effective therapeutics for γ-secretase-associated diseases such as AD and cancer.
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Affiliation(s)
- Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | | | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
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5
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Hur JY, Frost GR, Wu X, Crump C, Pan SJ, Wong E, Barros M, Li T, Nie P, Zhai Y, Wang JC, TCW J, Guo L, McKenzie A, Ming C, Zhou X, Wang M, Sagi Y, Renton AE, Esposito BT, Kim Y, Sadleir KR, Trinh I, Rissman RA, Vassar R, Zhang B, Johnson DS, Masliah E, Greengard P, Goate A, Li YM. The innate immunity protein IFITM3 modulates γ-secretase in Alzheimer's disease. Nature 2020; 586:735-740. [PMID: 32879487 PMCID: PMC7919141 DOI: 10.1038/s41586-020-2681-2] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 05/29/2020] [Indexed: 01/13/2023]
Abstract
Innate immunity is associated with Alzheimer's disease1, but the influence of immune activation on the production of amyloid-β is unknown2,3. Here we identify interferon-induced transmembrane protein 3 (IFITM3) as a γ-secretase modulatory protein, and establish a mechanism by which inflammation affects the generation of amyloid-β. Inflammatory cytokines induce the expression of IFITM3 in neurons and astrocytes, which binds to γ-secretase and upregulates its activity, thereby increasing the production of amyloid-β. The expression of IFITM3 is increased with ageing and in mouse models that express familial Alzheimer's disease genes. Furthermore, knockout of IFITM3 reduces γ-secretase activity and the formation of amyloid plaques in a transgenic mouse model (5xFAD) of early amyloid deposition. IFITM3 protein is upregulated in tissue samples from a subset of patients with late-onset Alzheimer's disease that exhibit higher γ-secretase activity. The amount of IFITM3 in the γ-secretase complex has a strong and positive correlation with γ-secretase activity in samples from patients with late-onset Alzheimer's disease. These findings reveal a mechanism in which γ-secretase is modulated by neuroinflammation via IFITM3 and the risk of Alzheimer's disease is thereby increased.
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Affiliation(s)
- Ji-Yeun Hur
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Georgia R. Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.,Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Xianzhong Wu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Christina Crump
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.,Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Si Jia Pan
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Marilia Barros
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Thomas Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.,Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Pengju Nie
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.,Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Yujia Zhai
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Jen Chyong Wang
- Ronald M. Loeb Center for Alzheimer’s Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Julia TCW
- Ronald M. Loeb Center for Alzheimer’s Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Lei Guo
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Andrew McKenzie
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chen Ming
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Xianxiao Zhou
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Minghui Wang
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yotam Sagi
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY, USA
| | - Alan E. Renton
- Ronald M. Loeb Center for Alzheimer’s Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bianca T. Esposito
- Ronald M. Loeb Center for Alzheimer’s Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yong Kim
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY, USA
| | | | - Ivy Trinh
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Robert A. Rissman
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Robert Vassar
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - Eliezer Masliah
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Paul Greengard
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY, USA
| | - Alison Goate
- Ronald M. Loeb Center for Alzheimer’s Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.,Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.,Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.,Correspondence to:
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6
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Escamilla-Ayala A, Wouters R, Sannerud R, Annaert W. Contribution of the Presenilins in the cell biology, structure and function of γ-secretase. Semin Cell Dev Biol 2020; 105:12-26. [DOI: 10.1016/j.semcdb.2020.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/06/2020] [Accepted: 02/17/2020] [Indexed: 01/25/2023]
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7
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Nie P, Vartak A, Li YM. γ-Secretase inhibitors and modulators: Mechanistic insights into the function and regulation of γ-Secretase. Semin Cell Dev Biol 2020; 105:43-53. [PMID: 32249070 DOI: 10.1016/j.semcdb.2020.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 02/08/2023]
Abstract
Over two decades, γ-secretase has been the target for extensive therapeutic development due to its pivotal role in pathogenesis of Alzheimer's disease and cancer. However, it has proven to be a challenging task owing to its large set of substrates and our limited understanding of the enzyme's structural and mechanistic features. The scientific community is taking bigger strides towards solving this puzzle with recent advancement in techniques like cryogenic electron microscopy (cryo-EM) and photo-affinity labelling (PAL). This review highlights the significance of the PAL technique with multiple examples of photo-probes developed from γ-secretase inhibitors and modulators. The binding of these probes into active and/or allosteric sites of the enzyme has provided crucial information on the γ-secretase complex and improved our mechanistic understanding of this protease. Combining the knowledge of function and regulation of γ-secretase will be a decisive factor in developing novel γ-secretase modulators and biological therapeutics.
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Affiliation(s)
- Pengju Nie
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Pharmacology program, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Abhishek Vartak
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Pharmacology program, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.
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8
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Krishna BM, Jana S, Singhal J, Horne D, Awasthi S, Salgia R, Singhal SS. Notch signaling in breast cancer: From pathway analysis to therapy. Cancer Lett 2019; 461:123-131. [PMID: 31326555 DOI: 10.1016/j.canlet.2019.07.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 01/15/2023]
Abstract
The Notch signaling pathway, which is highly conserved from sea urchins to humans, plays an important role in cell-differentiation, survival, proliferation, stem-cell renewal, and determining cell fate during development and morphogenesis. It is well established that signaling pathways are dysregulated in a wide-range of diseases, including human malignancies. Studies suggest that the dysregulation of the Notch pathway contributes to carcinogenesis, cancer stem cell renewal, angiogenesis, and chemo-resistance. Elevated levels of Notch receptors and ligands have been associated with cancer-progression and poor survival. Furthermore, the Notch signaling pathway regulates the transcriptional activity of key target genes through crosstalk with several other signaling pathways. Indeed, increasing evidence suggests that the Notch signaling pathway may serve as a therapeutic target for the treatment of several cancers, including breast cancer. Researchers have demonstrated the anti-tumor properties of Notch inhibitors in various cancer types. Currently, Notch inhibitors are being evaluated for anticancer efficacy in a number of clinical-trials. However, because there are multiple Notch receptors that can exhibit either oncogenic or tumor-suppressing roles in various cells, it is important that the Notch inhibitors are specific to particular receptors that are tumorigenic in nature. This review critically evaluates existing Notch inhibitory drugs and strategies and summarizes the previous discoveries, current understandings, and recent developments in support of Notch receptors as therapeutic targets in breast cancer.
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Affiliation(s)
- B Madhu Krishna
- Department of Medical Oncology, Beckman Research Institute of City of Hope, Comprehensive Cancer Center and National Medical Center, Duarte, CA, 91010, USA
| | - Samir Jana
- Department of Medical Oncology, Beckman Research Institute of City of Hope, Comprehensive Cancer Center and National Medical Center, Duarte, CA, 91010, USA
| | - Jyotsana Singhal
- Department of Medical Oncology, Beckman Research Institute of City of Hope, Comprehensive Cancer Center and National Medical Center, Duarte, CA, 91010, USA
| | - David Horne
- Department of Molecular Medicine, Beckman Research Institute of City of Hope, Comprehensive Cancer Center and National Medical Center, Duarte, CA, 91010, USA
| | - Sanjay Awasthi
- Department of Internal Medicine, Division of Hematology & Oncology, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA
| | - Ravi Salgia
- Department of Medical Oncology, Beckman Research Institute of City of Hope, Comprehensive Cancer Center and National Medical Center, Duarte, CA, 91010, USA
| | - Sharad S Singhal
- Department of Medical Oncology, Beckman Research Institute of City of Hope, Comprehensive Cancer Center and National Medical Center, Duarte, CA, 91010, USA.
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9
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Abstract
γ-Secretase cleaves multiple transmembrane proteins, but little is known about how it controls its substrate specificity. γ-Secretase activating protein (GSAP) has been reported to differentially activate γ-secretase for APP and Notch cleavages. The mechanism by which GSAP regulates γ-secretase specificity is elusive. Here, we demonstrate that GSAP directly regulates γ-secretase activity and specificity. Furthermore, GSAP functions as a switch between two forms of γ-secretase that have different activities for APP and Notch substrates, leading to different specificities. These findings open a new avenue for drug development through targeting the specificity of modifying proteins. This work also suggests that the association of GSAP with aging, Alzheimer’s disease, and Down syndrome could be attributed to the function of GSAP in the regulation of γ-secretase. The mechanism by which γ-secretase activating protein (GSAP) regulates γ-secretase activity has not yet been elucidated. Here, we show that knockout of GSAP in cultured cells directly reduces γ-secretase activity for Aβ production, but not for Notch1 cleavage, suggesting that GSAP may induce a conformational change contributing to the specificity of γ-secretase. Furthermore, using an active-site–directed photoprobe with double cross-linking moieties, we demonstrate that GSAP modifies the orientation and/or distance of the PS1 N-terminal fragment and the PS1 C-terminal fragment, a region containing the active site of γ-secretase. This work offers insight into how GSAP regulates γ-secretase specificity.
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10
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Jeon YH, Ha M, Kim SW, Kim MJ, Lee CS, Oh CK, Han ME, Oh SO, Kim YH. Evaluation of the prognostic significances of γ-secretase genes in pancreatic cancer. Oncol Lett 2019; 17:4614-4620. [PMID: 30944650 PMCID: PMC6444455 DOI: 10.3892/ol.2019.10113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 02/19/2019] [Indexed: 12/19/2022] Open
Abstract
With the growing requirement for novel prognostic biomarkers for pancreatic cancer, many studies have focused on clinical and/or genomic variables. Although many studies have been performed, carbohydrate antigen 19-9 is the only biomarker in clinical use. Therefore, the present study examined whether γ-secretase genes, including presenilin (PSEN), nicastrin (NCSTN), presenilin enhancer protein 2 (PSENEN), and anterior pharynx-defective 1 (APH1-), could serve as prognostic factors for pancreatic cancer. The cohorts selected included >100 pancreatic cancer patients. Patient data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GSE21501). The prognostic roles of the γ-secretase genes were analyzed by several survival analysis methods. Among the γ-secretase genes, the prognosis tended to be worse in the 2 cohorts with increasing expression of PSEN1, APH1A, and PSENEN, while the remaining genes were the opposite in the 2 cohorts. Notably, although the patient characteristics were quite different, APH1A was statistically significantly associated with prognosis in the 2 cohorts. The hazard ratio of APH1A for overall survival was 1.598 (TCGA) and 2.724 (GSE21501). These results contribute to the study of γ-secretase in pancreatic cancer. We believe that γ-secretase, particularly APH1A, will be a new prognostic biomarker for pancreatic cancer.
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Affiliation(s)
- Yun Ho Jeon
- Department of Pediatrics, Busan St. Mary's Hospital, Busan 48575, Republic of Korea
| | - Mihyang Ha
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan 50612, Republic of Korea
| | - Sung Won Kim
- Department of Pediatrics, Busan St. Mary's Hospital, Busan 48575, Republic of Korea
| | - Mun Ju Kim
- Department of Pediatrics, Busan St. Mary's Hospital, Busan 48575, Republic of Korea
| | - Chi-Seung Lee
- Biomedical Research Institute, Pusan National University Hospital, Busan 49241, Republic of Korea
| | - Chang-Kyu Oh
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Myoung-Eun Han
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan 50612, Republic of Korea
| | - Sae-Ock Oh
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan 50612, Republic of Korea
| | - Yun Hak Kim
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan 50612, Republic of Korea.,Biomedical Research Institute, Pusan National University Hospital, Busan 49241, Republic of Korea.,Department of Biomedical Informatics, School of Medicine, Pusan National University, Yangsan 50612, Republic of Korea
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11
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Johnson DS, Li YM, Pettersson M, St George-Hyslop PH. Structural and Chemical Biology of Presenilin Complexes. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a024067. [PMID: 28320827 PMCID: PMC5710098 DOI: 10.1101/cshperspect.a024067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The presenilin proteins are the catalytic subunits of a tetrameric complex containing presenilin 1 or 2, anterior pharynx defective 1 (APH1), nicastrin, and PEN-2. Other components such as TMP21 may exist in a subset of specialized complexes. The presenilin complex is the founding member of a unique class of aspartyl proteases that catalyze the γ, ɛ, ζ site cleavage of the transmembrane domains of Type I membrane proteins including amyloid precursor protein (APP) and Notch. Here, we detail the structural and chemical biology of this unusual enzyme. Taken together, these studies suggest that the complex exists in several conformations, and subtle long-range (allosteric) shifts in the conformation of the complex underpin substrate access to the catalytic site and the mechanism of action for allosteric inhibitors and modulators. Understanding the mechanics of these shifts will facilitate the design of γ-secretase modulator (GSM) compounds that modulate the relative efficiency of γ, ɛ, ζ site cleavage and/or substrate specificity.
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Affiliation(s)
- Douglas S. Johnson
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Martin Pettersson
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | - Peter H. St George-Hyslop
- Cambridge Institute for Medical Research, Wellcome Trust MRC Building, Addenbrookes Hospital, Cambridge CB2 0XY, United Kingdom,Tanz Centre for Research in Neurodegenerative Diseases and Departments of Medicine, Laboratory Medicine and Pathobiology, and Medical Biophysics, University of Toronto, Toronto, Ontario M5T 2S8, Canada
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12
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Crump CJ, Murrey HE, Ballard TE, am Ende CW, Wu X, Gertsik N, Johnson DS, Li YM. Development of Sulfonamide Photoaffinity Inhibitors for Probing Cellular γ-Secretase. ACS Chem Neurosci 2016; 7:1166-73. [PMID: 27253220 DOI: 10.1021/acschemneuro.6b00127] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
γ-Secretase is a multiprotein complex that catalyzes intramembrane proteolysis associated with Alzheimer's disease and cancer. Here, we have developed potent sulfonamide clickable photoaffinity probes that target γ-secretase in vitro and in cells by incorporating various photoreactive groups and walking the clickable alkyne handle to different positions around the molecule. We found that benzophenone is preferred over diazirine as a photoreactive group within the sulfonamide scaffold for labeling γ-secretase. Intriguingly, the placement of the alkyne at different positions has little effect on probe potency but has a significant impact on the efficiency of labeling of γ-secretase. Moreover, the optimized clickable photoprobe, 163-BP3, was utilized as a cellular probe to effectively assess the target engagement of inhibitors with γ-secretase in primary neuronal cells. In addition, biotinylated 163-BP3 probes were developed and used to capture the native γ-secretase complex in the 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonate (CHAPSO) solubilized state. Taken together, these next generation clickable and biotinylated sulfonamide probes offer new tools to study γ-secretase in biochemical and cellular systems. Finally, the data provide insights into structural features of the sulfonamide inhibitor binding site in relation to the active site and into the design of clickable photoaffinity probes.
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Affiliation(s)
- Christina J. Crump
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
| | - Heather E. Murrey
- Pfizer Worldwide Research and Development, Worldwide Medicinal Chemistry, Cambridge, Massachusetts 02139, United States
| | - T. Eric Ballard
- Pfizer Worldwide Research and Development, Worldwide
Medicinal Chemistry Groton, Connecticut 06340, United States
| | - Christopher W. am Ende
- Pfizer Worldwide Research and Development, Worldwide
Medicinal Chemistry Groton, Connecticut 06340, United States
| | - Xianzhong Wu
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
| | - Natalya Gertsik
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
| | - Douglas S. Johnson
- Pfizer Worldwide Research and Development, Worldwide Medicinal Chemistry, Cambridge, Massachusetts 02139, United States
| | - Yue-Ming Li
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
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13
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Carroll CM, Li YM. Physiological and pathological roles of the γ-secretase complex. Brain Res Bull 2016; 126:199-206. [PMID: 27133790 DOI: 10.1016/j.brainresbull.2016.04.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/19/2016] [Accepted: 04/27/2016] [Indexed: 12/27/2022]
Abstract
Gamma-secretase (GS) is an enzyme complex that cleaves numerous substrates, and it is best known for cleaving amyloid precursor protein (APP) to form amyloid-beta (Aβ) peptides. Aberrant cleavage of APP can lead to Alzheimer's disease, so much research has been done to better understand GS structure and function in hopes of developing therapeutics for Alzheimer's. Therefore, most of the attention in this field has been focused on developing modulators that reduce pathogenic forms of Aβ while leaving Notch and other GS substrates intact, but GS provides multiple avenues of modulation that could improve AD pathology. GS has complex regulation, through its essential subunits and other associated proteins, providing other targets for AD drugs. Therapeutics can also alter GS trafficking and thereby improve cognition, or move beyond Aβ entirely, effecting Notch and neural stem cells. GS also cleaves substrates that affect synaptic morphology and function, presenting another window by which GS modulation could improve AD pathology. Taken together, GS presents a unique cross road for neural processes and an ideal target for AD therapeutics.
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Affiliation(s)
- Courtney M Carroll
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, NY, United States; Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, NY, United States.
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, NY, United States; Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, NY, United States; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, NY, United States
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14
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Gilchrist ML, Ahn K, Li YM. Imaging and Functional Analysis of γ-Secretase and Substrate in a Proteolipobead System with an Activity-Based Probe. Anal Chem 2016; 88:1303-11. [PMID: 26699370 PMCID: PMC4911041 DOI: 10.1021/acs.analchem.5b03762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Investigation of intramembranal protease catalysis demands the generation of intact biomembrane assemblies with structural integrity and lateral mobility. Here, we report the development of a microsphere supported-biomembrane platform enabling characterization of γ-secretase and substrate within proteolipobead assemblies via microscopy and flow cytometry. The active enzyme loading levels were tracked using an activity-based probe, with the biomembranes delineated by carbocyanine lipid reporters. Proteolipobeads formed from HeLa proteoliposomes gave rise to homogeneous distributions of active γ-secretase within supported biomembranes with native-like fluidity. The substrate loading into supported biomembranes was detergent-dependent, as evidenced by even colocalization of substrate and lipid tracers in confocal 3D imaging of individual proteolipobeads. Moreover, the loading level was tunable with bulk substrate concentration. γ-Secretase substrate cleavage and its inhibition within γ-secretase proteolipobeads were observed. This platform offers a means to visualize enzyme and substrate loading, activity, and inhibition in a controllable biomembrane microenvironment.
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Affiliation(s)
- M. Lane Gilchrist
- Department of Chemical Engineering and the Department of Biomedical Engineering, The City College of the City University of New York, 140th Street and Convent Avenue, New York, New York 10031, United States
| | - Kwangwook Ahn
- Chemistry Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Yue-Ming Li
- Chemistry Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10021, United States
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15
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Li Y, Liew LSY, Li Q, Kang C. Structure of the transmembrane domain of human nicastrin-a component of γ-secretase. Sci Rep 2016; 6:19522. [PMID: 26776682 PMCID: PMC4726005 DOI: 10.1038/srep19522] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/09/2015] [Indexed: 02/04/2023] Open
Abstract
Nicastrin is the largest component of γ-secretase that is an intramembrane protease important in the development of Alzheimer's disease. Nicastrin contains a large extracellular domain, a single transmembrane (TM) domain, and a short C-terminus. Its TM domain is important for the γ-secretase complex formation. Here we report nuclear magnetic resonance (NMR) studies of the TM and C-terminal regions of human nicastrin in both sodium dodecyl sulfate (SDS) and dodecylphosphocholine (DPC) micelles. Structural study and dynamic analysis reveal that the TM domain is largely helical and stable under both SDS and DPC micelles with its N-terminal region undergoing intermediate time scale motion. The TM helix contains a hydrophilic patch that is important for TM-TM interactions. The short C-terminus is not structured in solution and a region formed by residues V697-A702 interacts with the membrane, suggesting that these residues may play a role in the γ-secretase complex formation. Our study provides structural insight into the function of the nicastrin TM domain and the C-terminus in γ-secretase complex.
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Affiliation(s)
- Yan Li
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - Lynette Sin Yee Liew
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - Qingxin Li
- Institute of Chemical &Engineering Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - CongBao Kang
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
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16
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Teranishi Y, Inoue M, Yamamoto NG, Kihara T, Wiehager B, Ishikawa T, Winblad B, Schedin-Weiss S, Frykman S, Tjernberg LO. Proton myo-inositol cotransporter is a novel γ-secretase associated protein that regulates Aβ production without affecting Notch cleavage. FEBS J 2015; 282:3438-51. [DOI: 10.1111/febs.13353] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 06/01/2015] [Accepted: 06/16/2015] [Indexed: 01/09/2023]
Affiliation(s)
- Yasuhiro Teranishi
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
- Dainippon Sumitomo Pharma Co., Ltd; Drug Development Research Laboratories; Osaka Japan
| | - Mitsuhiro Inoue
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
- Dainippon Sumitomo Pharma Co., Ltd; Drug Development Research Laboratories; Osaka Japan
| | - Natsuko Goto Yamamoto
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
- Dainippon Sumitomo Pharma Co., Ltd; Drug Development Research Laboratories; Osaka Japan
| | - Takahiro Kihara
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
- Dainippon-Sumitomo Pharma Co., Ltd; Genomic Science Laboratories; Osaka Japan
| | - Birgitta Wiehager
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
| | - Taizo Ishikawa
- Dainippon Sumitomo Pharma Co., Ltd; Innovative Drug Discovery Research Laboratories; Osaka Japan
| | - Bengt Winblad
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
| | - Sophia Schedin-Weiss
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
| | - Susanne Frykman
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
| | - Lars O. Tjernberg
- Division for Neurogeriatrics; Department of NVS; Center for Alzheimer Research; Karolinska Institutet; Huddinge Sweden
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17
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Gertsik N, Chiu D, Li YM. Complex regulation of γ-secretase: from obligatory to modulatory subunits. Front Aging Neurosci 2015; 6:342. [PMID: 25610395 PMCID: PMC4285130 DOI: 10.3389/fnagi.2014.00342] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 12/09/2014] [Indexed: 11/29/2022] Open
Abstract
γ-Secretase is a four subunit, 19-pass transmembrane enzyme that cleaves amyloid precursor protein (APP), catalyzing the formation of amyloid beta (Aβ) peptides that form amyloid plaques, which contribute to Alzheimer’s disease (AD) pathogenesis. γ-Secretase also cleaves Notch, among many other type I transmembrane substrates. Despite its seemingly promiscuous enzymatic capacity, γ-secretase activity is tightly regulated. This regulation is a function of many cellular entities, including but not limited to the essential γ-secretase subunits, nonessential (modulatory) subunits, and γ-secretase substrates. Regulation is also accomplished by an array of cellular events, such as presenilin (active subunit of γ-secretase) endoproteolysis and hypoxia. In this review we discuss how γ-secretase is regulated with the hope that an advanced understanding of these mechanisms will aid in the development of effective therapeutics for γ-secretase-associated diseases like AD and Notch-addicted cancer.
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Affiliation(s)
- Natalya Gertsik
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center New York, NY, USA ; Biochemistry and Molecular Biology Program, Weill Graduate School of Medical Sciences of Cornell University New York, NY, USA
| | - Danica Chiu
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center New York, NY, USA ; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University New York, NY, USA
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center New York, NY, USA ; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University New York, NY, USA
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18
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Villa JC, Chiu D, Brandes AH, Escorcia FE, Villa CH, Maguire WF, Hu CJ, de Stanchina E, Simon MC, Sisodia SS, Scheinberg DA, Li YM. Nontranscriptional role of Hif-1α in activation of γ-secretase and notch signaling in breast cancer. Cell Rep 2014; 8:1077-92. [PMID: 25131208 DOI: 10.1016/j.celrep.2014.07.028] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 03/04/2014] [Accepted: 07/16/2014] [Indexed: 12/11/2022] Open
Abstract
γ-Secretase is composed of four proteins that are obligatory for protease activity: presenilin, nicastrin, Aph1, and Pen-2. Despite the progress toward understanding the function of these individual subunits, there is no information available pertaining to the modulation of γ-secretase in response to environmental changes in cells. Here, we show that hypoxia upregulates γ-secretase activity through a direct interaction with Hif-1α, revealing an unconventional function for Hif-1α as an enzyme subunit, which is distinct from its canonical role as a transcription factor. Moreover, hypoxia-induced cell invasion and metastasis are alleviated by either γ-secretase inhibitors or a dominant-negative Notch coactivator, indicating that γ-secretase/Notch signaling plays an essential role in controlling these cellular processes. The present study reveals a mechanism in which γ-secretase can achieve temporal control through conditional interactions with regulatory proteins, such as Hif-1α, under select physiological and pathological conditions.
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Affiliation(s)
- Jennifer C Villa
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Danica Chiu
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Alissa H Brandes
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Freddy E Escorcia
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Carlos H Villa
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - William F Maguire
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Cheng-Jun Hu
- Molecular Biology Graduate Program, School of Dental Medicine, University of Colorado, Aurora, CO 80045, USA
| | - Elisa de Stanchina
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Sangram S Sisodia
- The Center for Molecular Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - David A Scheinberg
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.
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19
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Treadmill exercise represses neuronal cell death and inflammation during Aβ-induced ER stress by regulating unfolded protein response in aged presenilin 2 mutant mice. Apoptosis 2014; 18:1332-1347. [PMID: 23907580 DOI: 10.1007/s10495-013-0884-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Alzheimer's disease (AD) is characterized by the deposition of aggregated amyloid-beta (Aβ), which triggers a cellular stress response called the unfolded protein response (UPR). The UPR signaling pathway is a cellular defense system for dealing with the accumulation of misfolded proteins but switches to apoptosis when endoplasmic reticulum (ER) stress is prolonged. ER stress is involved in neurodegenerative diseases including AD, but the molecular mechanisms of neuronal apoptosis and inflammation by Aβ-induced ER stress to exercise training are not fully understood. Here, we demonstrated that treadmill exercise (TE) prevented PS2 mutation-induced memory impairment and reduced Aβ-42 deposition through the inhibition of β-secretase (BACE-1) and its product, C-99 in cortex and/or hippocampus of aged PS2 mutant mice. We also found that TE down-regulated the expression of GRP78/Bip and PDI proteins and inhibited activation of PERK, eIF2α, ATF6α, sXBP1 and JNK-p38 MAPK as well as activation of CHOP, caspase-12 and caspase-3. Moreover, TE up-regulated the expression of Bcl-2 and down-regulated the expressions of Bax in the hippocampus of aged PS2 mutant mice. Finally, the generation of TNFα and IL-1α and the number of TUNEL-positive cells in the hippocampus of aged PS2 mutant mice was also prevented or decreased by TE. These results showed that TE suppressed the activation of UPR signaling pathways as well as inhibited the apoptotic pathways of the UPR and inflammatory response following Aβ-induced ER stress. Thus, therapeutic strategies that modulate Aβ-induced ER stress through TE could represent a promising approach for the prevention or treatment of AD.
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20
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Ballard TE, Murrey HE, Geoghegan KF, am Ende CW, Johnson DS. Investigating γ-secretase protein interactions in live cells using active site-directed clickable dual-photoaffinity probes. MEDCHEMCOMM 2014. [DOI: 10.1039/c3md00283g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Clickable γ-secretase active site-directed dual-photoaffinity probes specifically label components of the γ-secretase complex and form crosslinks between PS1-NTF and PS1-CTF.
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Affiliation(s)
- T. Eric Ballard
- Neuroscience Medicinal Chemistry and Chemical Biology
- Pfizer Worldwide Research and Development
- Cambridge
- USA
- Neuroscience Medicinal Chemistry
| | - Heather E. Murrey
- Neuroscience Medicinal Chemistry and Chemical Biology
- Pfizer Worldwide Research and Development
- Cambridge
- USA
| | - Kieran F. Geoghegan
- Structural Biology and Biophysics
- Pfizer Worldwide Research and Development
- Groton
- USA
| | | | - Douglas S. Johnson
- Neuroscience Medicinal Chemistry and Chemical Biology
- Pfizer Worldwide Research and Development
- Cambridge
- USA
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21
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Wang P, Su C, Li R, Wang H, Ren Y, Sun H, Yang J, Sun J, Shi J, Tian J, Jiang S. Mechanisms and effects of curcumin on spatial learning and memory improvement in APPswe/PS1dE9 mice. J Neurosci Res 2013; 92:218-31. [PMID: 24273069 DOI: 10.1002/jnr.23322] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 09/10/2013] [Accepted: 10/10/2013] [Indexed: 12/11/2022]
Abstract
Evidence suggests that curcumin, the phytochemical agent in the spice turmeric, might be a potential therapy for Alzheimer's disease (AD). Its antioxidant, anti-inflammatory properties have been investigated extensively. Studies have also shown that curcumin can reduce amyloid pathology in AD. The underlying mechanism, however, is complex and is still being explored. In this study, we used the APPswe/PS1dE9 double transgenic mice, an AD model, to investigate the effects and mechanisms of curcumin in the prevention and treatment of AD. The water maze test indicated that curcumin can improve spatial learning and memory ability in mice. Immunohistochemical staining and Western blot analysis were used to test major proteins in β-amyloid aggregation, β-amyloid production, and β-amyloid clearance. Data showed that, 3 months after administration, curcumin treatment reduced Aβ40 , Aβ42 , and aggregation of Aβ-derived diffusible ligands in the mouse hippocampal CA1 area; reduced the expression of the γ-secretase component presenilin-2; and increased the expression of β-amyloid-degrading enzymes, including insulin-degrading enzymes and neprilysin. This evidence suggests that curcumin, as a potential AD therapeutic method, can reduce β-amyloid pathological aggregation, possibly through mechanisms that prevent its production by inhibiting presenilin-2 and/or by accelerating its clearance by increasing degrading enzymes such as insulin-degrading enzyme and neprilysin.
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Affiliation(s)
- Pengwen Wang
- Key Laboratory of Chinese Internal Medicine, Ministry of Education, Beijing University of Chinese Medicine (BUCM), China; Key Laboratory of Pharmacology of Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, China
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22
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Peltonen HM, Haapasalo A, Hiltunen M, Kataja V, Kosma VM, Mannermaa A. Γ-secretase components as predictors of breast cancer outcome. PLoS One 2013; 8:e79249. [PMID: 24223915 PMCID: PMC3815159 DOI: 10.1371/journal.pone.0079249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/19/2013] [Indexed: 12/26/2022] Open
Abstract
γ-secretase is a large ubiquitously expressed protease complex composed of four core subunits: presenilin, Aph1, PEN-2, and nicastrin. The function of γ-secretase in the cells is to proteolytically cleave various proteins within their transmembrane domains. Presenilin and Aph1 occur as alternative variants belonging to mutually exclusive γ-secretase complexes and providing the complexes with heterogeneous biochemical and physiological properties. γ-secretase is proposed to have a role in the development and progression of cancer and γ-secretase inhibitors are intensively studied for their probable anti-tumor effects in various types of cancer models. Here, we for the first time determined mRNA expression levels of presenilin-1, presenilin-2, Aph1a, Aph1b, PEN-2, and nicastrin in a set of breast cancer tissue samples (N = 55) by quantitative real-time PCR in order to clarify the clinical significance of the expression of different γ-secretase complex components in breast cancer. We found a high positive correlation between the subunit expression levels implying a common regulation of transcription. Our univariate Kaplan-Meier survival analyses established low expression level of γ-secretase complex as a risk factor for breast cancer specific mortality. The tumors expressing low levels of γ-secretase complex were characterized by high histopathological tumor grade, low or no expression of estrogen and progesterone receptors and consequently high probability to fall into the class of triple negative breast cancer tumors. These results may provide novel tools to further categorize breast cancer tumors, especially the highly aggressive and poorly treatable breast cancer type of triple negative cases, and suggest a significant role for γ-secretase in breast cancer.
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Affiliation(s)
- Hanna M. Peltonen
- Institute of Clinical Medicine, Pathology and Forensic Medicine, University of Eastern Finland, Kuopio, Finland
- Biocenter Kuopio and Cancer Center of Eastern Finland, University of Eastern Finland, Kuopio, Finland
- Imaging Center, Clinical Pathology, Kuopio University Hospital, Kuopio, Finland
- * E-mail:
| | - Annakaisa Haapasalo
- Institute of Clinical Medicine – Neurology, University of Eastern Finland, Kuopio, Finland
| | - Mikko Hiltunen
- Institute of Clinical Medicine – Neurology, University of Eastern Finland, Kuopio, Finland
| | - Vesa Kataja
- Institute of Clinical Medicine, Oncology, University of Eastern Finland, Kuopio, Finland
- Cancer Center, Kuopio University Hospital, Kuopio, Finland
| | - Veli-Matti Kosma
- Institute of Clinical Medicine, Pathology and Forensic Medicine, University of Eastern Finland, Kuopio, Finland
- Biocenter Kuopio and Cancer Center of Eastern Finland, University of Eastern Finland, Kuopio, Finland
- Imaging Center, Clinical Pathology, Kuopio University Hospital, Kuopio, Finland
| | - Arto Mannermaa
- Institute of Clinical Medicine, Pathology and Forensic Medicine, University of Eastern Finland, Kuopio, Finland
- Biocenter Kuopio and Cancer Center of Eastern Finland, University of Eastern Finland, Kuopio, Finland
- Imaging Center, Clinical Pathology, Kuopio University Hospital, Kuopio, Finland
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23
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Crump CJ, Johnson DS, Li YM. Development and mechanism of γ-secretase modulators for Alzheimer's disease. Biochemistry 2013; 52:3197-216. [PMID: 23614767 DOI: 10.1021/bi400377p] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
γ-Secretase is an aspartyl intramembranal protease composed of presenilin, Nicastrin, Aph1, and Pen2 with 19 transmembrane domains. γ-Secretase cleaves the amyloid precursor proteins (APP) to release Aβ peptides that likely play a causative role in the pathogenesis of Alzheimer's disease (AD). In addition, γ-secretase cleaves Notch and other type I membrane proteins. γ-Secretase inhibitors (GSIs) have been developed and used for clinical studies. However, clinical trials have shown adverse effects of GSIs that are potentially linked with nondiscriminatory inhibition of Notch signaling, overall APP processing, and other substrate cleavages. Therefore, these findings call for the development of disease-modifying agents that target γ-secretase activity to lower levels of Aβ42 production without blocking the overall processing of γ-secretase substrates. γ-Secretase modulators (GSMs) originally derived from nonsteroidal anti-inflammatory drugs (NSAIDs) display such characteristics and are the focus of this review. However, first-generation GSMs have limited potential because of the low potency and undesired neuropharmacokinetic properties. This generation of GSMs has been suggested to interact with the APP substrate, γ-secretase, or both. To improve the potency and brain availability, second-generation GSMs, including NSAID-derived carboxylic acid and non-NSAID-derived heterocyclic chemotypes, as well as natural product-derived GSMs have been developed. Animal studies of this generation of GSMs have shown encouraging preclinical profiles. Moreover, using potent GSM photoaffinity probes, multiple studies unambiguously have showed that both carboxylic acid and heterocyclic GSMs specifically target presenilin, the catalytic subunit of γ-secretase. In addition, two types of GSMs have distinct binding sites within the γ-secretase complex and exhibit different Aβ profiles. GSMs induce a conformational change of γ-secretase to achieve modulation. Various models are proposed and discussed. Despite the progress of GSM research, many outstanding issues remain to be investigated to achieve the ultimate goal of developing GSMs as effective AD therapies.
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Affiliation(s)
- Christina J Crump
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center , 1275 York Avenue, New York, New York 10065, United States
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A patient with posterior cortical atrophy possesses a novel mutation in the presenilin 1 gene. PLoS One 2013; 8:e61074. [PMID: 23593396 PMCID: PMC3625161 DOI: 10.1371/journal.pone.0061074] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 03/05/2013] [Indexed: 12/17/2022] Open
Abstract
Posterior cortical atrophy is a dementia syndrome with symptoms of cortical visual dysfunction, associated with amyloid plaques and neurofibrillary tangles predominantly affecting visual association cortex. Most patients diagnosed with posterior cortical atrophy will finally develop a typical Alzheimer's disease. However, there are a variety of neuropathological processes, which could lead towards a clinical presentation of posterior cortical atrophy. Mutations in the presenilin 1 gene, affecting the function of γ-secretase, are the most common genetic cause of familial, early-onset Alzheimer's disease. Here we present a patient with a clinical diagnosis of posterior cortical atrophy who harbors a novel Presenilin 1 mutation (I211M). In silico analysis predicts that the mutation could influence the interaction between presenilin 1 and presenilin1 enhancer-2 protein, a protein partner within the γ-secretase complex. These findings along with published literature support the inclusion of posterior cortical atrophy on the Alzheimer's disease spectrum.
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25
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Park HJ, Shabashvili D, Nekorchuk MD, Shyqyriu E, Jung JI, Ladd TB, Moore BD, Felsenstein KM, Golde TE, Kim SH. Retention in endoplasmic reticulum 1 (RER1) modulates amyloid-β (Aβ) production by altering trafficking of γ-secretase and amyloid precursor protein (APP). J Biol Chem 2012; 287:40629-40. [PMID: 23043097 PMCID: PMC3504776 DOI: 10.1074/jbc.m112.418442] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 10/05/2012] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Aβ production is influenced by intracellular trafficking of secretases and amyloid precursor protein (APP). RESULTS Retention in endoplasmic reticulum 1 (RER1) regulates the trafficking of γ-secretase and APP, thereby influences Aβ production. CONCLUSION RER1, an ER retention/retrieval factor for γ-secretase and APP, modulates Aβ production. SIGNIFICANCE RER1 and its influence on γ-secretase and APP may be implicated for a safe strategy to target Aβ production. The presence of neuritic plaques containing aggregated amyloid-β (Aβ) peptides in the brain parenchyma is a pathological hallmark of Alzheimer disease (AD). Aβ is generated by sequential cleavage of the amyloid β precursor protein (APP) by β- and γ-secretase, respectively. As APP processing to Aβ requires transport through the secretory pathway, trafficking of the substrate and access to the secretases are key factors that can influence Aβ production (Thinakaran, G., and Koo, E. H. (2008) Amyloid precursor protein trafficking, processing, and function. J. Biol. Chem. 283, 29615-29619). Here, we report that retention in endoplasmic reticulum 1 (RER1) associates with γ-secretase in early secretory compartments and regulates the intracellular trafficking of γ-secretase. RER1 overexpression decreases both γ-secretase localization on the cell surface and Aβ secretion and conversely RER1 knockdown increases the level of cell surface γ-secretase and increases Aβ secretion. Furthermore, we find that increased RER1 levels decrease mature APP and increase immature APP, resulting in less surface accumulation of APP. These data show that RER1 influences the trafficking and localization of both γ-secretase and APP, thereby regulating the production and secretion of Aβ peptides.
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Affiliation(s)
- Hyo-Jin Park
- From the Department of Pharmacology and Therapeutics, and
- the Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610
| | | | | | - Eva Shyqyriu
- From the Department of Pharmacology and Therapeutics, and
| | - Joo In Jung
- the Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610
| | - Thomas B. Ladd
- the Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610
| | - Brenda D. Moore
- the Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610
| | - Kevin M. Felsenstein
- the Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610
| | - Todd E. Golde
- the Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610
| | - Seong-Hun Kim
- From the Department of Pharmacology and Therapeutics, and
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26
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Nishimura M, Nakamura SI, Kimura N, Liu L, Suzuki T, Tooyama I. Age-related modulation of γ-secretase activity in non-human primate brains. J Neurochem 2012; 123:21-8. [DOI: 10.1111/j.1471-4159.2012.07884.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Chau DM, Crump CJ, Villa JC, Scheinberg DA, Li YM. Familial Alzheimer disease presenilin-1 mutations alter the active site conformation of γ-secretase. J Biol Chem 2012; 287:17288-17296. [PMID: 22461631 DOI: 10.1074/jbc.m111.300483] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Presenilin-1 (PS1) is the catalytic subunit of γ-secretase, and mutations in this protein cause familial Alzheimer Disease (FAD). However, little is known about how these mutations affect the active site of γ-secretase. Here, we show that PS1 mutations alter the S2 subsite within the active site of γ-secretase using a multiple photoaffinity probe approach called "photophore walking." Moreover, we developed a unique in vitro assay with a biotinylated recombinant Notch1 substrate and demonstrated that PS1 FAD mutations directly and significantly reduced γ-secretase activity for Notch1 cleavage. Substitution of the Notch Cys-1752 residue, which interacts with the S2 subsite, with Val, Met, or Ile has little effect on wild-type PS1 but leads to more efficient substrates for mutant PS1s. This study indicates that alteration of this S2 subsite plays an important role in determining the activity and specificity of γ-secretase for APP and Notch1 processing, which provides structural basis and insights on how certain PS1 FAD mutations lead to AD pathogenesis.
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Affiliation(s)
- De-Ming Chau
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021
| | - Christina J Crump
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021
| | - Jennifer C Villa
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021
| | - David A Scheinberg
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021.
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28
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Crump CJ, Fish BA, Castro SV, Chau DM, Gertsik N, Ahn K, Stiff C, Pozdnyakov N, Bales KR, Johnson DS, Li YM. Piperidine acetic acid based γ-secretase modulators directly bind to Presenilin-1. ACS Chem Neurosci 2011; 2:705-710. [PMID: 22229075 DOI: 10.1021/cn200098p] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Aβ42 is believed to play a causative role in Alzheimer's disease (AD) pathogenesis. γ-Secretase modulators (GSMs) are actively being pursued as potential AD therapeutics because they selectively alter the cleavage site of the amyloid precursor protein (APP) to reduce the formation of Aβ42. However, the binding partner of acid based GSMs was unresolved until now. We have developed clickable photoaffinity probes based on piperidine acetic acid GSM-1 and identified PS1 as the target within the γ-secretase complex. Furthermore, we provide evidence that allosteric interaction of GSMs with PS1 results in a conformational change in the active site of the γ-secretase complex leading to the observed modulation of γ-secretase activity.
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Affiliation(s)
- Christina J. Crump
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Benjamin A. Fish
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Suita V. Castro
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - De-Ming Chau
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Natalya Gertsik
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Kwangwook Ahn
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Cory Stiff
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Nikolay Pozdnyakov
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Kelly R. Bales
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Douglas S. Johnson
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Yue-Ming Li
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
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29
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Li T, Li YM, Ahn K, Price DL, Sisodia SS, Wong PC. Increased expression of PS1 is sufficient to elevate the level and activity of γ-secretase in vivo. PLoS One 2011; 6:e28179. [PMID: 22140537 PMCID: PMC3226664 DOI: 10.1371/journal.pone.0028179] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 11/02/2011] [Indexed: 11/18/2022] Open
Abstract
Increase in the generation and deposition of amyloid-β (Aβ) plays a central role in the development of Alzheimer's Disease (AD). Elevation of the activity of γ-secretase, a key enzyme required for the generation for Aβ, can thus be a potential risk factor in AD. However, it is not known whether γ-secretase can be upregulated in vivo. While in vitro studies showed that expression of all four components of γ-secretase (Nicastrin, Presenilin, Pen-2 and Aph-1) are required for upregulation of γ-secretase, it remains to be established as to whether this is true in vivo. To investigate whether overexpressing a single component of the γ-secretase complex is sufficient to elevate its level and activity in the brain, we analyzed transgenic mice expressing either wild type or familial AD (fAD) associated mutant PS1. In contrast to cell culture studies, overexpression of either wild type or mutant PS1 is sufficient to increase levels of Nicastrin and Pen-2, and elevate the level of active γ-secretase complex, enzymatic activity of γ-secretase and the deposition of Aβ in brains of mice. Importantly, γ-secretase comprised of mutant PS1 is less active than that of wild type PS1-containing γ-secretase; however, γ-secretase comprised of mutant PS1 cleaves at the Aβ42 site of APP-CTFs more efficiently than at the Aβ40 site, resulting in greater accumulation of Aβ deposits in the brain. Our data suggest that whereas fAD-linked PS1 mutants cause early onset disease, upregulation of PS1/γ-secretase activity may be a risk factor for late onset sporadic AD.
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Affiliation(s)
- Tong Li
- Department of Pathology, The Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America.
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30
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Renzi F, Zhang X, Rice WJ, Torres-Arancivia C, Gomez-Llorente Y, Diaz R, Ahn K, Yu C, Li YM, Sisodia SS, Ubarretxena-Belandia I. Structure of gamma-secretase and its trimeric pre-activation intermediate by single-particle electron microscopy. J Biol Chem 2011; 286:21440-9. [PMID: 21454611 PMCID: PMC3122203 DOI: 10.1074/jbc.m110.193326] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 03/09/2011] [Indexed: 11/06/2022] Open
Abstract
The γ-secretase membrane protein complex is responsible for proteolytic maturation of signaling precursors and catalyzes the final step in the production of the amyloid β-peptides implicated in the pathogenesis of Alzheimer disease. The incorporation of PEN-2 (presenilin enhancer 2) into a pre-activation intermediate, composed of the catalytic subunit presenilin and the accessory proteins APH-1 (anterior pharynx-defective 1) and nicastrin, triggers the endoproteolysis of presenilin and results in an active tetrameric γ-secretase. We have determined the three-dimensional reconstruction of a mature and catalytically active γ-secretase using single-particle cryo-electron microscopy. γ-Secretase has a cup-like shape with a lateral belt of ∼40-50 Å in height that encloses a water-accessible internal chamber. Active site labeling with a gold-coupled transition state analog inhibitor suggested that the γ-secretase active site faces this chamber. Comparison with the structure of a trimeric pre-activation intermediate suggested that the incorporation of PEN-2 might contribute to the maturation of the active site architecture.
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Affiliation(s)
- Fabiana Renzi
- From the Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York 10029
- the Universita' di Roma “La Sapienza” 2, Rome 00185, Italy
| | - Xulun Zhang
- the Department of Neurobiology, The University of Chicago, Chicago, Illinois 60637
| | - William J. Rice
- the New York Structural Biology Center, New York, New York 10027
| | - Celia Torres-Arancivia
- From the Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York 10029
- the Graduate Center, City University of New York, New York, New York 10016
| | - Yacob Gomez-Llorente
- From the Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York 10029
| | - Ruben Diaz
- the New York Structural Biology Center, New York, New York 10027
| | - Kwangwook Ahn
- the Memorial Sloan-Kettering Cancer Center, New York, New York 10065, and
| | - Chunjiang Yu
- the Department of Anatomy and Cell Biology, the University of Illinois, Chicago, Illinois 60612
| | - Yue-Ming Li
- the Memorial Sloan-Kettering Cancer Center, New York, New York 10065, and
| | - Sangram S. Sisodia
- the Department of Neurobiology, The University of Chicago, Chicago, Illinois 60637
| | - Iban Ubarretxena-Belandia
- From the Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York 10029
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31
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Teranishi Y, Hur JY, Welander H, Frånberg J, Aoki M, Winblad B, Frykman S, Tjernberg LO. Affinity pulldown of γ-secretase and associated proteins from human and rat brain. J Cell Mol Med 2011; 14:2675-86. [PMID: 19754663 PMCID: PMC4373488 DOI: 10.1111/j.1582-4934.2009.00907.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
γ-Secretase is a transmembrane protease complex responsible for the processing of a multitude of type 1 transmembrane proteins, including amyloid precursor protein (APP) and Notch. A functional complex is dependent on the assembly of four proteins: presenilin (PS), nicastrin, Aph-1 and Pen-2. Little is known about how the substrates are selected by γ-secretase, but it has been suggested that γ-secretase associated proteins (GSAPs) could be of importance. For instance, it was recently reported from studies in cell lines that TMP21, a transmembrane protein involved in trafficking, binds to γ-secretase and regulates the processing of APP-derived substrates without affecting Notch cleavage. Here, we present an efficient and selective method for purification and analysis of γ-secretase and GSAPs. Microsomal membranes were prepared from rat or human brain and incubated with a γ-secretase inhibitor coupled to biotin via a long linker and a S-S bridge. After pulldown using streptavidin beads, bound proteins were eluted under reducing conditions and digested by trypsin. The tryptic peptides were subjected to LC-MS/MS analysis, and proteins were identified by sequence data from MS/MS spectra. All of the known γ-secretase components were identified. Interestingly, TMP21 and the PS associated protein syntaxin1 were associated to γ-secretase in rat brain. We suggest that the present method can be used for further studies on the composition of the γ-secretase complex.
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Affiliation(s)
- Yasuhiro Teranishi
- The Karolinska Institutet (KI) Dainippon Sumitomo Pharma Alzheimer Center (KASPAC), KI-Alzheimer's Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Novum, Huddinge, Sweden
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32
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Obulesu M, Somashekhar R, Venu R. Genetics of Alzheimer's Disease: An Insight Into Presenilins and Apolipoprotein E Instigated Neurodegeneration. Int J Neurosci 2011; 121:229-36. [DOI: 10.3109/00207454.2010.551432] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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33
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Frånberg J, Svensson AI, Winblad B, Karlström H, Frykman S. Minor contribution of presenilin 2 for γ-secretase activity in mouse embryonic fibroblasts and adult mouse brain. Biochem Biophys Res Commun 2011; 404:564-8. [DOI: 10.1016/j.bbrc.2010.12.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 12/04/2010] [Indexed: 10/18/2022]
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34
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Jayadev S, Case A, Eastman AJ, Nguyen H, Pollak J, Wiley JC, Möller T, Morrison RS, Garden GA. Presenilin 2 is the predominant γ-secretase in microglia and modulates cytokine release. PLoS One 2010; 5:e15743. [PMID: 21206757 PMCID: PMC3012089 DOI: 10.1371/journal.pone.0015743] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 11/23/2010] [Indexed: 01/09/2023] Open
Abstract
Presenilin 1 (PS1) and Presenilin 2 (PS2) are the enzymatic component of the γ-secretase complex that cleaves amyloid precursor protein (APP) to release amyloid beta (Aβ) peptide. PS deficiency in mice results in neuroinflammation and neurodegeneration in the absence of accumulated Aβ. We hypothesize that PS influences neuroinflammation through its γ-secretase action in CNS innate immune cells. We exposed primary murine microglia to a pharmacological γ-secretase inhibitor which resulted in exaggerated release of TNFα and IL-6 in response to lipopolysaccharide. To determine if this response was mediated by PS1, PS2 or both we used shRNA to knockdown each PS in a murine microglia cell line. Knockdown of PS1 did not lead to decreased γ-secretase activity while PS2 knockdown caused markedly decreased γ-secretase activity. Augmented proinflammatory cytokine release was observed after knockdown of PS2 but not PS1. Proinflammatory stimuli increased microglial PS2 gene transcription and protein in vitro. This is the first demonstration that PS2 regulates CNS innate immunity. Taken together, our findings suggest that PS2 is the predominant γ-secretase in microglia and modulates release of proinflammatory cytokines. We propose PS2 may participate in a negative feedback loop regulating inflammatory behavior in microglia.
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Affiliation(s)
- Suman Jayadev
- Department of Neurology, University of Washington, Seattle, Washington, United States of America.
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35
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Gamma-secretase activating protein is a therapeutic target for Alzheimer's disease. Nature 2010; 467:95-8. [PMID: 20811458 PMCID: PMC2936959 DOI: 10.1038/nature09325] [Citation(s) in RCA: 238] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Accepted: 07/05/2010] [Indexed: 12/19/2022]
Abstract
Accumulation of neurotoxic βamyloid (Aβ) is a major hallmark of Alzheimer's disease (AD)1. Formation of Aβ is catalyzed by γsecretase, a protease with numerous substrates2,3. Little is known about the molecular mechanisms that confer substrate specificity on this potentially promiscuous enzyme. Knowledge of the mechanisms underlying its selectivity is critical for the development of clinically effective γ-secretase inhibitors that can reduce Aβ formation without impairing cleavage of other γ-secretase substrates, especially Notch, which is essential for normal biological functions3,4. Here we report the discovery of a novel γ-secretase activating protein (gSAP), which dramatically and selectively increases Aβ production through a mechanism involving its interactions with both γsecretase and its substrate, the amyloid precursor protein C-terminal fragment (APP-CTF). gSAP does not interact with Notch nor does it affect its cleavage. Recombinant gSAP stimulates Aβ production in vitro. Reducing gSAP levels in cell lines decreases Aβ levels. Knockdown of gSAP in a mouse model of Alzheimers disease reduces levels of Aβ and plaque development. gSAP represents a new type of γ-secretase regulator that directs enzyme specificity by interacting with a specific substrate. We demonstrate that imatinib, an anti-cancer drug previously found to inhibit Aβ formation without affecting Notch cleavage5, achieves its Aβ-lowering effect by preventing gSAP interaction with the γ-secretase substrate, APP-CTF. Thus, gSAP can serve as an Aβ-lowering therapeutic target without affecting other key functions of γ-secretase.
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36
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Kounnas MZ, Danks AM, Cheng S, Tyree C, Ackerman E, Zhang X, Ahn K, Nguyen P, Comer D, Mao L, Yu C, Pleynet D, Digregorio PJ, Velicelebi G, Stauderman KA, Comer WT, Mobley WC, Li YM, Sisodia SS, Tanzi RE, Wagner SL. Modulation of gamma-secretase reduces beta-amyloid deposition in a transgenic mouse model of Alzheimer's disease. Neuron 2010; 67:769-80. [PMID: 20826309 PMCID: PMC2947312 DOI: 10.1016/j.neuron.2010.08.018] [Citation(s) in RCA: 194] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2010] [Indexed: 12/25/2022]
Abstract
Alzheimer's disease (AD) is characterized pathologically by the abundance of senile plaques and neurofibrillary tangles in the brain. We synthesized over 1200 novel gamma-secretase modulator (GSM) compounds that reduced Abeta(42) levels without inhibiting epsilon-site cleavage of APP and Notch, the generation of the APP and Notch intracellular domains, respectively. These compounds also reduced Abeta(40) levels while concomitantly elevating levels of Abeta(38) and Abeta(37). Immobilization of a potent GSM onto an agarose matrix quantitatively recovered Pen-2 and to a lesser degree PS-1 NTFs from cellular extracts. Moreover, oral administration (once daily) of another potent GSM to Tg 2576 transgenic AD mice displayed dose-responsive lowering of plasma and brain Abeta(42); chronic daily administration led to significant reductions in both diffuse and neuritic plaques. These effects were observed in the absence of Notch-related changes (e.g., intestinal proliferation of goblet cells), which are commonly associated with repeated exposure to functional gamma-secretase inhibitors (GSIs).
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Affiliation(s)
| | | | - Soan Cheng
- TorreyPines Therapeutics, Inc., La Jolla, CA 92037
| | - Curtis Tyree
- TorreyPines Therapeutics, Inc., La Jolla, CA 92037
| | | | - Xulun Zhang
- The Center for Molecular Neurobiology, University of Chicago, Chicago, IL 60637
| | - Kwangwook Ahn
- Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | | | - Dan Comer
- TorreyPines Therapeutics, Inc., La Jolla, CA 92037
| | - Long Mao
- TorreyPines Therapeutics, Inc., La Jolla, CA 92037
| | - Chengzhi Yu
- TorreyPines Therapeutics, Inc., La Jolla, CA 92037
| | | | | | | | | | | | | | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Sangram S. Sisodia
- The Center for Molecular Neurobiology, University of Chicago, Chicago, IL 60637
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, Massachusetts General Hospital, Dept. of Neurology, Charlestown, MA 02129
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37
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Placanica L, Chien JW, Li YM. Characterization of an atypical gamma-secretase complex from hematopoietic origin. Biochemistry 2010; 49:2796-804. [PMID: 20178366 DOI: 10.1021/bi901388t] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Gamma-secretase is a widely expressed multisubunit enzyme complex which is involved in the pathogenesis of Alzheimer disease and hematopoietic malignancies through its aberrant processing of the amyloid precursor protein (APP) and Notch1, respectively. While gamma-secretase has been extensively studied, there is a dearth of information surrounding the activity, composition, and function of gamma-secretase expressed in distinct cellular populations. Here we show that endogenous gamma-secretase complexes of hematopoietic origin are distinct from epithelial derived gamma-secretase complexes. Hematopoietic gamma-secretase has reduced activity for APP and Notch1 processing compared to epithelial gamma-secretase. Characterization of the active complexes with small molecule affinity probes reveals that hematopoietic gamma-secretase has an atypical subunit composition with significantly altered subunit stoichiometry. Furthermore, we demonstrate that these discrete complexes exhibit cell-line specific substrate selectivity suggesting a possible mechanism of substrate regulation. These data underscore the need for studying endogenous gamma-secretase to fully understand of the biology of gamma-secretase and its complexity as a molecular target for the development of disease therapeutics.
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Affiliation(s)
- Lisa Placanica
- Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
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Frånberg J, Karlström H, Winblad B, Tjernberg LO, Frykman S. gamma-Secretase dependent production of intracellular domains is reduced in adult compared to embryonic rat brain membranes. PLoS One 2010; 5:e9772. [PMID: 20333303 PMCID: PMC2841641 DOI: 10.1371/journal.pone.0009772] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 02/25/2010] [Indexed: 12/20/2022] Open
Abstract
Background γ-Secretase is an intramembrane aspartyl protease whose cleavage of the amyloid precursor protein (APP) generates the amyloid β-peptide (Aβ) and the APP intracellular domain. Aβ is widely believed to have a causative role in Alzheimer's disease pathogenesis, and therefore modulation of γ-secretase activity has become a therapeutic goal. Besides APP, more than 50 substrates of γ-secretase with different cellular functions during embryogenesis as well as adulthood have been revealed. Prior to γ-secretase cleavage, substrates are ectodomain shedded, producing membrane bound C-terminal fragments (CTFs). Principal Findings Here, we investigated γ-secretase cleavage of five substrates; APP, Notch1, N-cadherin, ephrinB and p75 neurotrophin receptor (p75-NTR) in membranes isolated from embryonic, young or old adult rat brain by analyzing the release of the corresponding intracellular domains (ICDs) or Aβ40 by western blot analysis and ELISA respectively. The highest levels of all ICDs and Aβ were produced by embryonic membranes. In adult rat brain only cleavage of APP and Notch1 could be detected and the Aβ40 and ICD production from these substrates was similar in young and old adult rat brain. The CTF levels of Notch1, N-cadherin, ephrinB and p75-NTR were also clearly decreased in the adult brain compared to embryonic brain, whereas the APP CTF levels were only slightly decreased. Conclusions In summary our data suggests that γ-secretase dependent ICD production is down-regulated in the adult brain compared to embryonic brain. In addition, the present approach may be useful for evaluating the specificity of γ-secretase inhibitors.
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Affiliation(s)
- Jenny Frånberg
- Karolinska Institutet Alzheimer's Disease Research Center (KI-ADRC), Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden.
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Yang T, Arslanova D, Xu X, Li YM, Xia W. In vivo manifestation of Notch related phenotypes in zebrafish treated with Alzheimer's amyloid reducing gamma-secretase inhibitors. J Neurochem 2010; 113:1200-9. [PMID: 20345767 DOI: 10.1111/j.1471-4159.2010.06681.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Gamma-secretase is responsible for the final cleavage of amyloid precursor protein to generate the amyloid-beta protein, the major component of plaques in the brains of Alzheimer's disease patients. gamma-Secretase inhibitors (GSI) have been explored for therapeutic inhibition of amyloid beta protein generation, but mechanistic toxicity has been documented because of its blockage of gamma-secretase cleavage of several dozens of substrates including Notch. This becomes the primary obstacle for most inhibitors during the pre-clinical development and the main concern for several compounds in the clinical trials. To predict potential side effects related to Notch signaling, we examined global effect of GSIs in vertebrate animal zebrafish. We have used two potent GSIs (GSI A and GSI 18) with a sub-microM effective concentration for 50% amyloid beta protein inhibition (EC(50)). Zebrafish embryos were treated with GSI A, 18 or a well characterized GSI N-[N-(3,5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT), and transparent animals were examined for up to 7 days. GSI A had less abnormal phenotype in zebrafish, compared to GSI 18-treated embryos that displayed curved tails, a loss of pigmentation, and reduced swim bladder and heart rate. To understand mechanistic effect at the molecular level, we examined Notch signaling in these GSI-treated zebrafish. Notch phenotypes were observed in embryos treated with 50 and 10 microM GSI 18, but not with 10 microM GSI A. In accordance, in situ hybridization with a probe against Notch target gene her6 showed a weaker staining in embryos treated with 10 microM GSI 18 than those treated with 10 microM GSI A. In conclusion, phenotypic profile in whole animals offers important information on Notch related pathways and provides prediction of safe compounds during early development stages of therapeutic GSIs.
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Affiliation(s)
- Ting Yang
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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Groth C, Alvord WG, Quiñones OA, Fortini ME. Pharmacological analysis of Drosophila melanogaster gamma-secretase with respect to differential proteolysis of Notch and APP. Mol Pharmacol 2010; 77:567-74. [PMID: 20064975 DOI: 10.1124/mol.109.062471] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The gamma-secretase aspartyl protease is responsible for the cleavage of numerous type I integral membrane proteins, including amyloid precursor protein (APP) and Notch. APP cleavage contributes to the generation of toxic amyloid beta peptides in Alzheimer's disease, whereas cleavage of the Notch receptor is required for normal physiological signaling between differentiating cells. Mutagenesis studies as well as in vivo analyses of Notch and APP activity in the presence of pharmacological inhibitors indicate that these substrates can be differentially modulated by inhibition of mammalian gamma-secretase, although some biochemical studies instead show nearly identical dose-response inhibitor effects on Notch and APP cleavages. Here, we examine the dose-response effects of several inhibitors on Notch and APP in Drosophila melanogaster cells, which possess a homogeneous form of gamma-secretase. Four different inhibitors that target different domains of gamma-secretase exhibit similar dose-response effects for both substrates, including rank order of inhibitor potencies and effective concentration ranges. For two inhibitors, modest differences in inhibitor dose responses toward Notch and APP were detected, suggesting that inhibitors might be identified that possess some discrimination in their ability to target alternative gamma-secretase substrates. These findings also indicate that despite an overall conservation in inhibitor potencies toward different gamma-secretase substrates, quantitative differences might exist that could be relevant for the development of therapeutically valuable substrate-specific inhibitors.
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Affiliation(s)
- Casper Groth
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Bluemle Life Sciences Building 830A, 233 South 10 Street, Philadelphia, PA 19107, USA
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Krishnaswamy S, Verdile G, Groth D, Kanyenda L, Martins RN. The structure and function of Alzheimer’s gamma secretase enzyme complex. Crit Rev Clin Lab Sci 2009; 46:282-301. [DOI: 10.3109/10408360903335821] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Modulation of gamma-secretase specificity using small molecule allosteric inhibitors. Proc Natl Acad Sci U S A 2009; 106:20228-33. [PMID: 19906985 DOI: 10.1073/pnas.0910757106] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
gamma-Secretase cleaves multiple substrates within the transmembrane domain that include the amyloid precursor protein as well as the Notch family of receptors. These substrates are associated with Alzheimer disease and cancer. Despite extensive investigation of this protease, little is known regarding the regulation of gamma-secretase specificity. To discover selective inhibitors for drug development and for probing the mechanisms of gamma-secretase specificity, we screened chemical libraries and consequently developed a di-coumarin family of inhibitors that preferentially inhibit gamma-secretase-mediated production of Abeta42 over other cleavage activities. These coumarin dimer-based compounds interact with gamma-secretase by binding to an allosteric site. By developing a multiple photo-affinity probe approach, we demonstrate that this allosteric binding causes a conformational change within the active site of gamma-secretase at the S2 and S1 sub-sites that leads to selective inhibition of Abeta42. In conclusion, by using these di-coumarin compounds, we reveal a mechanism by which gamma-secretase specificity is regulated and provide insights into the molecular basis by which familial presenilin mutations may affect the active site and specificity of gamma-secretase. Furthermore, this class of selective inhibitors provides the basis for development of Alzheimer disease therapeutic agents.
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Placanica L, Zhu L, Li YM. Gender- and age-dependent gamma-secretase activity in mouse brain and its implication in sporadic Alzheimer disease. PLoS One 2009; 4:e5088. [PMID: 19352431 PMCID: PMC2661375 DOI: 10.1371/journal.pone.0005088] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Accepted: 02/26/2009] [Indexed: 12/12/2022] Open
Abstract
Alzheimer disease (AD) is an age-related disorder. Aging and female gender are two important risk factors associated with sporadic AD. However, the mechanism by which aging and gender contribute to the pathogenesis of sporadic AD is unclear. It is well known that genetic mutations in γ-secretase result in rare forms of early onset AD due to the aberrant production of Aβ42 peptides, which are the major constituents of senile plaques. However, the effect of age and gender on γ-secretase has not been fully investigated. Here, using normal wild-type mice, we show mouse brain γ-secretase exhibits gender- and age-dependent activity. Both male and female mice exhibit increased Aβ42∶Aβ40 ratios in aged brain, which mimics the effect of familial mutations of Presenilin-1, Presenlin-2, and the amyloid precursor protein on Aβ production. Additionally, female mice exhibit much higher γ-secretase activity in aged brain compared to male mice. Furthermore, both male and female mice exhibit a steady decline in Notch1 γ-secretase activity with aging. Using a small molecule affinity probe we demonstrate that male mice have less active γ-secretase complexes than female mice, which may account for the gender-associated differences in activity in aged brain. These findings demonstrate that aging can affect γ-secretase activity and specificity, suggesting a role for γ-secretase in sporadic AD. Furthermore, the increased APP γ-secretase activity seen in aged females may contribute to the increased incidence of sporadic AD in women and the aggressive Aβ plaque pathology seen in female mouse models of AD. In addition, deceased Notch γ-secretase activity may also contribute to neurodegeneration. Therefore, this study implicates altered γ-secretase activity and specificity as a possible mechanism of sporadic AD during aging.
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Affiliation(s)
- Lisa Placanica
- Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- Department of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York, United States of America
| | - Lei Zhu
- Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- Department of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York, United States of America
- * E-mail:
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Brunello L, Zampese E, Florean C, Pozzan T, Pizzo P, Fasolato C. Presenilin-2 dampens intracellular Ca2+ stores by increasing Ca2+ leakage and reducing Ca2+ uptake. J Cell Mol Med 2009; 13:3358-69. [PMID: 19382908 PMCID: PMC4516491 DOI: 10.1111/j.1582-4934.2009.00755.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have previously shown that familial Alzheimer’s disease mutants of presenilin-2 (PS2) and, to a lesser extent, of presenilin-1 (PS1) lower the Ca2+ concentration of intracellular stores. We here examined the mechanism by which wild-type and mutant PS2 affect store Ca2+ handling. By using HeLa, SH-SY5Y and MEFs as model cells, and recombinant aequorins as Ca2+ probes, we show evidence that transient expression of either wild-type or mutant PS2 increases the passive Ca2+ leakage: both ryanodine- and IP3-receptors contribute to Ca2+ exit out of the ER, whereas the ribosome translocon complex is not involved. In SH-SY5Y cells and MEFs, wild-type and mutant PS2 potently reduce the uptake of Ca2+ inside the stores, an effect that can be counteracted by over-expression of SERCA-2B. On this line, in wild-type MEFs, lowering the endogenous level of PS2 by RNA interference, increases the Ca2+-loading capability of intracellular stores. Furthermore, we show that in PS double knockout MEFs, reduction of Ca2+ stores is mimicked by the expression of PS2-D366A, a loss-of-function mutant, uncleaved because also devoid of presenilinase activity but not by co-expression of the two catalytic active fragments of PS2. In summary, both physiological and increased levels of wild-type and mutant PS2 reduce the Ca2+ uptake by intracellular stores. To exert this newly described function, PS2 needs to be in its full-length form, even if it can subsequently be cleaved.
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Affiliation(s)
- Lucia Brunello
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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