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Liu E, Zhang Y, Wang JZ. Updates in Alzheimer's disease: from basic research to diagnosis and therapies. Transl Neurodegener 2024; 13:45. [PMID: 39232848 PMCID: PMC11373277 DOI: 10.1186/s40035-024-00432-x] [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: 03/12/2024] [Accepted: 07/11/2024] [Indexed: 09/06/2024] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder, characterized pathologically by extracellular deposition of β-amyloid (Aβ) into senile plaques and intracellular accumulation of hyperphosphorylated tau (pTau) as neurofibrillary tangles. Clinically, AD patients show memory deterioration with varying cognitive dysfunctions. The exact molecular mechanisms underlying AD are still not fully understood, and there are no efficient drugs to stop or reverse the disease progression. In this review, we first provide an update on how the risk factors, including APOE variants, infections and inflammation, contribute to AD; how Aβ and tau become abnormally accumulated and how this accumulation plays a role in AD neurodegeneration. Then we summarize the commonly used experimental models, diagnostic and prediction strategies, and advances in periphery biomarkers from high-risk populations for AD. Finally, we introduce current status of development of disease-modifying drugs, including the newly officially approved Aβ vaccines, as well as novel and promising strategies to target the abnormal pTau. Together, this paper was aimed to update AD research progress from fundamental mechanisms to the clinical diagnosis and therapies.
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Affiliation(s)
- Enjie Liu
- Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Yao Zhang
- Department of Endocrine, Liyuan Hospital, Key Laboratory of Ministry of Education for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430077, China
| | - Jian-Zhi Wang
- Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226000, China.
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Epremyan KK, Mamaev DV, Zvyagilskaya RA. Alzheimer's Disease: Significant Benefit from the Yeast-Based Models. Int J Mol Sci 2023; 24:9791. [PMID: 37372938 DOI: 10.3390/ijms24129791] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 06/02/2023] [Accepted: 06/04/2023] [Indexed: 06/29/2023] Open
Abstract
Alzheimer's disease (AD) is an age-related, multifaceted neurological disorder associated with accumulation of aggregated proteins (amyloid Aβ and hyperphosphorylated tau), loss of synapses and neurons, and alterations in microglia. AD was recognized by the World Health Organization as a global public health priority. The pursuit of a better understanding of AD forced researchers to pay attention to well-defined single-celled yeasts. Yeasts, despite obvious limitations in application to neuroscience, show high preservation of basic biological processes with all eukaryotic organisms and offer great advantages over other disease models due to the simplicity, high growth rates on low-cost substrates, relatively simple genetic manipulations, the large knowledge base and data collections, and availability of an unprecedented amount of genomic and proteomic toolboxes and high-throughput screening techniques, inaccessible to higher organisms. Research reviewed above clearly indicates that yeast models, together with other, more simple eukaryotic models including animal models, C. elegans and Drosophila, significantly contributed to understanding Aβ and tau biology. These models allowed high throughput screening of factors and drugs that interfere with Aβ oligomerization, aggregation and toxicity, and tau hyperphosphorylation. In the future, yeast models will remain relevant, with a focus on creating novel high throughput systems to facilitate the identification of the earliest AD biomarkers among different cellular networks in order to achieve the main goal-to develop new promising therapeutic strategies to treat or prevent the disease.
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Affiliation(s)
- Khoren K Epremyan
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33/2, 119071 Moscow, Russia
| | - Dmitry V Mamaev
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33/2, 119071 Moscow, Russia
| | - Renata A Zvyagilskaya
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33/2, 119071 Moscow, Russia
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Specific Mutations near the Amyloid Precursor Protein Cleavage Site Increase γ-Secretase Sensitivity and Modulate Amyloid-β Production. Int J Mol Sci 2023; 24:ijms24043970. [PMID: 36835396 PMCID: PMC9959964 DOI: 10.3390/ijms24043970] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/16/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Amyloid-β peptides (Aβs) are produced via cleavage of the transmembrane region of the amyloid precursor protein (APP) by γ-secretase and are responsible for Alzheimer's disease. Familial Alzheimer's disease (FAD) is associated with APP mutations that disrupt the cleavage reaction and increase the production of neurotoxic Aβs, i.e., Aβ42 and Aβ43. Study of the mutations that activate and restore the cleavage of FAD mutants is necessary to understand the mechanism of Aβ production. In this study, using a yeast reconstruction system, we revealed that one of the APP FAD mutations, T714I, severely reduced the cleavage, and identified secondary APP mutations that restored the cleavage of APP T714I. Some mutants were able to modulate Aβ production by changing the proportions of Aβ species when introduced into mammalian cells. Secondary mutations include proline and aspartate residues; proline mutations are thought to act through helical structural destabilization, while aspartate mutations are thought to promote interactions in the substrate binding pocket. Our results elucidate the APP cleavage mechanism and could facilitate drug discovery.
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PSEN2 and ABCA7 variants causing early-onset preclinical pathological changes in Alzheimer's disease: a case report and literature review. Neurol Sci 2023; 44:1987-2001. [PMID: 36701017 DOI: 10.1007/s10072-023-06602-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/04/2023] [Indexed: 01/27/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is a debilitating and highly heritable neurodegenerative disease. Early-onset AD (EOAD) was defined as AD occurring before age 65. Although it has a high genetic risk, EOAD due to PSEN2 variation is very rare. ABCA7 is an important risk gene for AD. Previously reported cases mainly carried variations in a single pathogenic or risk gene. METHODS AND RESULTS: In this study, we report a 35-year-old female carrying variants in both the PSEN2 gene (c.640G > T p.V214L) and ABCA7 gene (c.2848G > A p.V950M). Four previously reported cases carried PSEN2 V214L, and no reported cases carried ABCA7 V950M. She had a history of migraine, patent foramen ovale, spontaneous subarachnoid hemorrhage without aneurysm, and multiple cerebral microhemorrhages. Her MMSE score was 24/30, and her MoCA score was 22/30. The concentration of Aβ42 and the ratio of Aβ42 to Aβ40 in cerebral spinal fluid were obviously decreased. Published variants of PSEN2 and ABCA7 in PubMed were reviewed, and the patients' characteristics were summarized and compared to provide information for the clinical diagnosis of AD. CONCLUSIONS It is necessary to conduct genetic screening in cases with atypical manifestations.
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Tábuas-Pereira M, Guerreiro R, Kun-Rodrigues C, Almeida MR, Brás J, Santana I. Whole-exome sequencing reveals PSEN1 and ATP7B combined variants as a possible cause of early-onset Lewy body dementia: a case study of genotype-phenotype correlation. Neurogenetics 2022; 23:279-283. [PMID: 36114914 PMCID: PMC9669161 DOI: 10.1007/s10048-022-00699-0] [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: 07/02/2022] [Accepted: 09/02/2022] [Indexed: 10/14/2022]
Abstract
Dementia with Lewy bodies is a neurodegenerative disease, sharing features with Parkinson's and Alzheimer's diseases. We report a case of a patient dementia with Lewy bodies carrying combined PSEN1 and ATP7B mutations. A man developed dementia with Lewy bodies starting at the age of 60 years. CSF biomarkers were of Alzheimer's disease and DaTSCAN was abnormal. Whole-exome sequencing revealed a heterozygous p.Ile408Thr PSEN1 variant and a homozygous p.Arg616Trp ATP7B variant. This case reinstates the need of considering ATP7B mutations when evaluating a patient with parkinsonism and supports p.Ile408Thr as a pathogenic PSEN1 variant.
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Affiliation(s)
- Miguel Tábuas-Pereira
- Neurology Department, Centro Hospitalar E Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-045, Coimbra, Portugal.
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
- Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.
- Centro Académico Clínico de Coimbra, University of Coimbra, Coimbra, Portugal.
| | - Rita Guerreiro
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
- Division of Psychiatry and Behavioral Medicine, Michigan State University College of Human Medicine, Grand Rapids, MI, USA
| | - Célia Kun-Rodrigues
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - Maria Rosário Almeida
- Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - José Brás
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
- Division of Psychiatry and Behavioral Medicine, Michigan State University College of Human Medicine, Grand Rapids, MI, USA
| | - Isabel Santana
- Neurology Department, Centro Hospitalar E Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-045, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- Centro Académico Clínico de Coimbra, University of Coimbra, Coimbra, Portugal
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Genetics, Functions, and Clinical Impact of Presenilin-1 (PSEN1) Gene. Int J Mol Sci 2022; 23:ijms231810970. [PMID: 36142879 PMCID: PMC9504248 DOI: 10.3390/ijms231810970] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/09/2022] [Accepted: 09/14/2022] [Indexed: 12/29/2022] Open
Abstract
Presenilin-1 (PSEN1) has been verified as an important causative factor for early onset Alzheimer's disease (EOAD). PSEN1 is a part of γ-secretase, and in addition to amyloid precursor protein (APP) cleavage, it can also affect other processes, such as Notch signaling, β-cadherin processing, and calcium metabolism. Several motifs and residues have been identified in PSEN1, which may play a significant role in γ-secretase mechanisms, such as the WNF, GxGD, and PALP motifs. More than 300 mutations have been described in PSEN1; however, the clinical phenotypes related to these mutations may be diverse. In addition to classical EOAD, patients with PSEN1 mutations regularly present with atypical phenotypic symptoms, such as spasticity, seizures, and visual impairment. In vivo and in vitro studies were performed to verify the effect of PSEN1 mutations on EOAD. The pathogenic nature of PSEN1 mutations can be categorized according to the ACMG-AMP guidelines; however, some mutations could not be categorized because they were detected only in a single case, and their presence could not be confirmed in family members. Genetic modifiers, therefore, may play a critical role in the age of disease onset and clinical phenotypes of PSEN1 mutations. This review introduces the role of PSEN1 in γ-secretase, the clinical phenotypes related to its mutations, and possible significant residues of the protein.
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Hidradenitis Suppurativa: A Perspective on Genetic Factors Involved in the Disease. Biomedicines 2022; 10:biomedicines10082039. [PMID: 36009585 PMCID: PMC9406067 DOI: 10.3390/biomedicines10082039] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/22/2022] Open
Abstract
Hidradenitis Suppurativa (HS) is a chronic inflammatory skin disease of the pilosebaceous unit, clinically consisting of painful nodules, abscesses, and sinus tracts mostly in, but not limited to, intertriginous skin areas. HS can be defined as a complex skin disease with multifactorial etiologies, including—among others—genetic, immunologic, epigenetic, and environmental factors. Based on genetic heterogeneity and complexity, three different forms can be recognized and considered separately as sporadic, familial, and syndromic. To date, several genetic variants associated to disease susceptibility, disease-onset, and/or treatment response have been reported; some of these reside in genes encoding the gamma-secretase subunits whereas others involve autoinflammatory and/or keratinization genes. The aim of this perspective work is to provide an overview of the contribution of several genetic studies encompassing family linkage analyses, target candidate gene studies, and -omic studies in this field. In our viewpoint, we discuss the role of genetics in Hidradenitis suppurativa considering findings based on Sanger sequencing as well as the more recent Next Generation Sequencing (i.e., exome sequencing or RNA Sequencing) with the aim of better understanding the etio-pathogenesis of the disease as well as identifying novel therapeutic strategies.
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Hur JY. γ-Secretase in Alzheimer's disease. Exp Mol Med 2022; 54:433-446. [PMID: 35396575 PMCID: PMC9076685 DOI: 10.1038/s12276-022-00754-8] [Citation(s) in RCA: 85] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/05/2022] [Accepted: 01/20/2022] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is caused by synaptic and neuronal loss in the brain. One of the characteristic hallmarks of AD is senile plaques containing amyloid β-peptide (Aβ). Aβ is produced from amyloid precursor protein (APP) by sequential proteolytic cleavages by β-secretase and γ-secretase, and the polymerization of Aβ into amyloid plaques is thought to be a key pathogenic event in AD. Since γ-secretase mediates the final cleavage that liberates Aβ, γ-secretase has been widely studied as a potential drug target for the treatment of AD. γ-Secretase is a transmembrane protein complex containing presenilin, nicastrin, Aph-1, and Pen-2, which are sufficient for γ-secretase activity. γ-Secretase cleaves >140 substrates, including APP and Notch. Previously, γ-secretase inhibitors (GSIs) were shown to cause side effects in clinical trials due to the inhibition of Notch signaling. Therefore, more specific regulation or modulation of γ-secretase is needed. In recent years, γ-secretase modulators (GSMs) have been developed. To modulate γ-secretase and to understand its complex biology, finding the binding sites of GSIs and GSMs on γ-secretase as well as identifying transiently binding γ-secretase modulatory proteins have been of great interest. In this review, decades of findings on γ-secretase in AD are discussed.
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Affiliation(s)
- Ji-Yeun Hur
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
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Huang DX, Yu X, Yu WJ, Zhang XM, Liu C, Liu HP, Sun Y, Jiang ZP. Calcium Signaling Regulated by Cellular Membrane Systems and Calcium Homeostasis Perturbed in Alzheimer’s Disease. Front Cell Dev Biol 2022; 10:834962. [PMID: 35281104 PMCID: PMC8913592 DOI: 10.3389/fcell.2022.834962] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/31/2022] [Indexed: 12/12/2022] Open
Abstract
Although anything that changes spatiotemporally could be a signal, cells, particularly neurons, precisely manipulate calcium ion (Ca2+) to transmit information. Ca2+ homeostasis is indispensable for neuronal functions and survival. The cytosolic Ca2+ concentration ([Ca2+]CYT) is regulated by channels, pumps, and exchangers on cellular membrane systems. Under physiological conditions, both endoplasmic reticulum (ER) and mitochondria function as intracellular Ca2+ buffers. Furthermore, efficient and effective Ca2+ flux is observed at the ER-mitochondria membrane contact site (ERMCS), an intracellular membrane juxtaposition, where Ca2+ is released from the ER followed by mitochondrial Ca2+ uptake in sequence. Hence, the ER intraluminal Ca2+ concentration ([Ca2+]ER), the mitochondrial matrix Ca2+ concentration ([Ca2+]MT), and the [Ca2+]CYT are related to each other. Ca2+ signaling dysregulation and Ca2+ dyshomeostasis are associated with Alzheimer’s disease (AD), an irreversible neurodegenerative disease. The present review summarizes the cellular and molecular mechanism underlying Ca2+ signaling regulation and Ca2+ homeostasis maintenance at ER and mitochondria levels, focusing on AD. Integrating the amyloid hypothesis and the calcium hypothesis of AD may further our understanding of pathogenesis in neurodegeneration, provide therapeutic targets for chronic neurodegenerative disease in the central nervous system.
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Affiliation(s)
- Dong-Xu Huang
- Department of Hand and Foot Surgery, The First Hospital of Jilin University, Changchun, China
| | - Xin Yu
- Department of Hand and Foot Surgery, The First Hospital of Jilin University, Changchun, China
| | - Wen-Jun Yu
- Department of Hand and Foot Surgery, The First Hospital of Jilin University, Changchun, China
| | - Xin-Min Zhang
- Department of Anesthesiology, The First Hospital of Jilin University, Changchun, China
| | - Chang Liu
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Hong-Ping Liu
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Yue Sun
- Deparment of The First Operating Room, The First Hospital of Jilin University, Changchun, China
| | - Zi-Ping Jiang
- Department of Hand and Foot Surgery, The First Hospital of Jilin University, Changchun, China
- *Correspondence: Zi-Ping Jiang,
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Martinez-Banaclocha M. N-Acetyl-Cysteine: Modulating the Cysteine Redox Proteome in Neurodegenerative Diseases. Antioxidants (Basel) 2022; 11:antiox11020416. [PMID: 35204298 PMCID: PMC8869501 DOI: 10.3390/antiox11020416] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/13/2022] [Accepted: 02/16/2022] [Indexed: 12/14/2022] Open
Abstract
In the last twenty years, significant progress in understanding the pathophysiology of age-associated neurodegenerative diseases has been made. However, the prevention and treatment of these diseases remain without clinically significant therapeutic advancement. While we still hope for some potential genetic therapeutic approaches, the current reality is far from substantial progress. With this state of the issue, emphasis should be placed on early diagnosis and prompt intervention in patients with increased risk of neurodegenerative diseases to slow down their progression, poor prognosis, and decreasing quality of life. Accordingly, it is urgent to implement interventions addressing the psychosocial and biochemical disturbances we know are central in managing the evolution of these disorders. Genomic and proteomic studies have shown the high molecular intricacy in neurodegenerative diseases, involving a broad spectrum of cellular pathways underlying disease progression. Recent investigations indicate that the dysregulation of the sensitive-cysteine proteome may be a concurrent pathogenic mechanism contributing to the pathophysiology of major neurodegenerative diseases, opening new therapeutic opportunities. Considering the incidence and prevalence of these disorders and their already significant burden in Western societies, they will become a real pandemic in the following decades. Therefore, we propose large-scale investigations, in selected groups of people over 40 years of age with decreased blood glutathione levels, comorbidities, and/or mild cognitive impairment, to evaluate supplementation of the diet with low doses of N-acetyl-cysteine, a promising and well-tolerated therapeutic agent suitable for long-term use.
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Specific Mutations in Aph1 Cause γ-Secretase Activation. Int J Mol Sci 2022; 23:ijms23010507. [PMID: 35008932 PMCID: PMC8745412 DOI: 10.3390/ijms23010507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 01/25/2023] Open
Abstract
Amyloid beta peptides (Aβs) are generated from amyloid precursor protein (APP) through multiple cleavage steps mediated by γ-secretase, including endoproteolysis and carboxypeptidase-like trimming. The generation of neurotoxic Aβ42/43 species is enhanced by familial Alzheimer's disease (FAD) mutations within the catalytic subunit of γ-secretase, presenilin 1 (PS1). FAD mutations of PS1 cause partial loss-of-function and decrease the cleavage activity. Activating mutations, which have the opposite effect of FAD mutations, are important for studying Aβ production. Aph1 is a regulatory subunit of γ-secretase; it is presumed to function as a scaffold of the complex. In this study, we identified Aph1 mutations that are active in the absence of nicastrin (NCT) using a yeast γ-secretase assay. We analyzed these Aph1 mutations in the presence of NCT; we found that the L30F/T164A mutation is activating. When introduced in mouse embryonic fibroblasts, the mutation enhanced cleavage. The Aph1 mutants produced more short and long Aβs than did the wild-type Aph1, without an apparent modulatory function. The mutants did not change the amount of γ-secretase complex, suggesting that L30F/T164A enhances catalytic activity. Our results provide insights into the regulatory function of Aph1 in γ-secretase activity.
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Barthelson K, Dong Y, Newman M, Lardelli M. PRESENILIN 1 Mutations Causing Early-Onset Familial Alzheimer's Disease or Familial Acne Inversa Differ in Their Effects on Genes Facilitating Energy Metabolism and Signal Transduction. J Alzheimers Dis 2021; 82:327-347. [PMID: 34024832 DOI: 10.3233/jad-210128] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The most common cause of early-onset familial Alzheimer's disease (EOfAD) is mutations in PRESENILIN 1 (PSEN1) allowing production of mRNAs encoding full-length, but mutant, proteins. In contrast, a single known frameshift mutation in PSEN1 causes familial acne inversa (fAI) without EOfAD. The molecular consequences of heterozygosity for these mutation types, and how they cause completely different diseases, remains largely unexplored. OBJECTIVE To analyze brain transcriptomes of young adult zebrafish to identify similarities and differences in the effects of heterozygosity for psen1 mutations causing EOfAD or fAI. METHODS RNA sequencing was performed on mRNA isolated from the brains of a single family of 6-month-old zebrafish siblings either wild type or possessing a single, heterozygous EOfAD-like or fAI-like mutation in their endogenous psen1 gene. RESULTS Both mutations downregulate genes encoding ribosomal subunits, and upregulate genes involved in inflammation. Genes involved in energy metabolism appeared significantly affected only by the EOfAD-like mutation, while genes involved in Notch, Wnt and neurotrophin signaling pathways appeared significantly affected only by the fAI-like mutation. However, investigation of direct transcriptional targets of Notch signaling revealed possible increases in γ-secretase activity due to heterozygosity for either psen1 mutation. Transcriptional adaptation due to the fAI-like frameshift mutation was evident. CONCLUSION We observed both similar and contrasting effects on brain transcriptomes of the heterozygous EOfAD-like and fAI-like mutations. The contrasting effects may illuminate how these mutation types cause distinct diseases.
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Affiliation(s)
- Karissa Barthelson
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Yang Dong
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Morgan Newman
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Michael Lardelli
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
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Wolfe MS. Probing Mechanisms and Therapeutic Potential of γ-Secretase in Alzheimer's Disease. MOLECULES (BASEL, SWITZERLAND) 2021; 26:molecules26020388. [PMID: 33450968 PMCID: PMC7828430 DOI: 10.3390/molecules26020388] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/02/2021] [Accepted: 01/10/2021] [Indexed: 12/14/2022]
Abstract
The membrane-embedded γ-secretase complex carries out hydrolysis within the lipid bilayer in proteolyzing nearly 150 different membrane protein substrates. Among these substrates, the amyloid precursor protein (APP) has been the most studied, as generation of aggregation-prone amyloid β-protein (Aβ) is a defining feature of Alzheimer's disease (AD). Mutations in APP and in presenilin, the catalytic component of γ-secretase, cause familial AD, strong evidence for a pathogenic role of Aβ. Substrate-based chemical probes-synthetic peptides and peptidomimetics-have been critical to unraveling the complexity of γ-secretase, and small drug-like inhibitors and modulators of γ-secretase activity have been essential for exploring the potential of the protease as a therapeutic target for Alzheimer's disease. Such chemical probes and therapeutic prototypes will be reviewed here, with concluding commentary on the future directions in the study of this biologically important protease complex and the translation of basic findings into therapeutics.
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Affiliation(s)
- Michael S Wolfe
- Department of Medicinal Chemistry, University of Kansas, 1567 Irving Hill Road, GLH-2115, Lawrence, KS 66045, USA
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Bustos V, Pulina MV, Ledo J. Amyloidogenic and anti-amyloidogenic properties of presenilin 1. ADVANCES IN PHARMACOLOGY 2020; 90:239-251. [PMID: 33706935 DOI: 10.1016/bs.apha.2020.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Presenilin 1 (PS1) is an intramembrane protease, the active subunit of the γ-secretase complex. Its well-studied function is the amyloidogenic cleavage of the C-terminal fragment of the amyloid precursor protein, also known as C99, to produce the Abeta peptide. Recent findings from the Greengard laboratory suggest that PS1 also have anti-amyloidogenic activities, which reduce Abeta levels. First, it redirects APP-C99 toward autophagic degradation, lowering the amount that can be converted into Abeta. The protein kinase CK1γ2 phosphorylates PS1 at Ser367. Phosphorylated PS1 at this position interacts with Annexin A2, which, in turn, interacts with the lysosomal N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) Vamp8. Annexin A2 facilitates the binding of Vamp8 to the autophagosomal SNARE Syntaxin 17 to modulate the fusion of autophagosomes with lysosomes. Thus, PS1 phosphorylated at Ser367 has an anti-amyloidogenic function, promoting autophagosome-lysosome fusion and increasing C99 degradation. Second, it enhances the ability of microglia to phagocyte and degrade extracellular Abeta oligomer, through regulating the expression of the lysosomal master regulator TFEB. Thus, PS1 has a role in both the production and the clearance of Abeta. Drugs designed to activate CK1γ2 and increase the level of PS1 phosphorylated at Ser367 should be useful in the treatment of Alzheimer's disease.
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Affiliation(s)
- Victor Bustos
- Laboratory of Cellular and Molecular Neuroscience, Rockefeller University, New York, NY, United States.
| | - Maria V Pulina
- Laboratory of Cellular and Molecular Neuroscience, Rockefeller University, New York, NY, United States
| | - Jose Ledo
- Laboratory of Cellular and Molecular Neuroscience, Rockefeller University, New York, NY, United States
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15
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Evolutionary History of Alzheimer Disease-Causing Protein Family Presenilins with Pathological Implications. J Mol Evol 2020; 88:674-688. [DOI: 10.1007/s00239-020-09966-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 09/22/2020] [Indexed: 12/14/2022]
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16
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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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17
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Cai T, Tomita T. Structure-activity relationship of presenilin in γ-secretase-mediated intramembrane cleavage. Semin Cell Dev Biol 2020; 105:102-109. [PMID: 32171519 DOI: 10.1016/j.semcdb.2020.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 01/12/2023]
Abstract
Genetic research on familial cases of Alzheimer disease have identified presenilin (PS) as an important membrane protein in the pathomechanism of this disease. PS is the catalytic subunit of γ-secretase, which is responsible for the generation of amyloid-β peptide deposited in the brains of Alzheimer disease patients. γ-Secretase is an atypical protease composed of four membrane proteins (i.e., presenilin, nicastrin, anterior pharynx defective-1 (Aph-1), and presenilin enhancer-2 (Pen-2)) and mediates intramembrane proteolysis. Numerous investigations have been conducted toward understanding the structural features of γ-secretase components as well as the cleavage mechanism of γ-secretase. In this review, we summarize our current understanding of the structure and activity relationship of the γ-secretase complex.
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Affiliation(s)
- Tetsuo Cai
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.
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18
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Galla L, Redolfi N, Pozzan T, Pizzo P, Greotti E. Intracellular Calcium Dysregulation by the Alzheimer's Disease-Linked Protein Presenilin 2. Int J Mol Sci 2020; 21:E770. [PMID: 31991578 PMCID: PMC7037278 DOI: 10.3390/ijms21030770] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia. Even though most AD cases are sporadic, a small percentage is familial due to autosomal dominant mutations in amyloid precursor protein (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2) genes. AD mutations contribute to the generation of toxic amyloid β (Aβ) peptides and the formation of cerebral plaques, leading to the formulation of the amyloid cascade hypothesis for AD pathogenesis. Many drugs have been developed to inhibit this pathway but all these approaches currently failed, raising the need to find additional pathogenic mechanisms. Alterations in cellular calcium (Ca2+) signaling have also been reported as causative of neurodegeneration. Interestingly, Aβ peptides, mutated presenilin-1 (PS1), and presenilin-2 (PS2) variously lead to modifications in Ca2+ homeostasis. In this contribution, we focus on PS2, summarizing how AD-linked PS2 mutants alter multiple Ca2+ pathways and the functional consequences of this Ca2+ dysregulation in AD pathogenesis.
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Affiliation(s)
- Luisa Galla
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (L.G.); (N.R.); (T.P.); (E.G.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
| | - Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (L.G.); (N.R.); (T.P.); (E.G.)
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (L.G.); (N.R.); (T.P.); (E.G.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
- Venetian Institute of Molecular Medicine (VIMM), 35131 Padua, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (L.G.); (N.R.); (T.P.); (E.G.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
| | - Elisa Greotti
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (L.G.); (N.R.); (T.P.); (E.G.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
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19
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Vöglein J, Willem M, Trambauer J, Schönecker S, Dieterich M, Biskup S, Giudici C, Utz K, Oberstein T, Brendel M, Rominger A, Danek A, Steiner H, Haass C, Levin J. Identification of a rare presenilin 1 single amino acid deletion mutation (F175del) with unusual amyloid-β processing effects. Neurobiol Aging 2019; 84:241.e5-241.e11. [DOI: 10.1016/j.neurobiolaging.2019.08.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/22/2019] [Accepted: 08/31/2019] [Indexed: 10/26/2022]
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20
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Blanco JA, Alonso A, Blanco J, Rojo E, Tellería JJ, Torres MA, Uribe F. Novel presenilin 1 mutation (p.Thr-Pro116-117Ser-Thr) in a Spanish family with early-onset Alzheimer's disease. Neurobiol Aging 2019; 84:238.e19-238.e24. [PMID: 31204041 DOI: 10.1016/j.neurobiolaging.2019.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 11/26/2022]
Abstract
Presenilin 1 (PSEN1) is a γ-secretase component, which is in charge of the amyloid precursor protein (APP) cleavage. APP is believed to play a central role in the pathogenesis of Alzheimer's disease (AD). PSEN1 mutations are the most important causes of familial AD, being related to the earlier onset and rapid progression of the disease. Presenilins and APP mutations represent an extraordinary opportunity to study the pathophysiology of AD. We describe the clinical and genetic study of a 37-year-old male patient with a novel mutation in PSEN1 (p.Thr-Pro116-117Ser-Thr). We have studied the pedigree of his family with a further 9 members affected, all of them with onset in their 30s. We have also described the clinical data and results of brain biopsies in 2 of them. DNA sequencing of a tissue sample from an uncle of the patient, who died of AD in the 80s, showed the same mutation as in the patient. These data and predictive analysis indicate the pathogenicity of the mutation.
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Affiliation(s)
- Jose Antonio Blanco
- Psychiatry Service, Clinical University Hospital of Valladolid, Valladolid, Spain; School of Medicine, University of Valladolid, Valladolid, Spain.
| | - Adrian Alonso
- Psychiatry Service, Clinical University Hospital of Valladolid, Valladolid, Spain
| | - Jorge Blanco
- Psychiatry Service, Basurto Hospital of Bilbao, Bilbao, Spain
| | - Esther Rojo
- Neurology Service, Clinical University Hospital of Valladolid, Valladolid, Spain
| | | | - Maria Angeles Torres
- Histopathology Service, Rio Hortega University Hospital of Valladolid, Valladolid, Spain
| | - Fernando Uribe
- Psychiatry Service, Clinical University Hospital of Valladolid, Valladolid, Spain
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21
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Yuksel M, Tacal O. Trafficking and proteolytic processing of amyloid precursor protein and secretases in Alzheimer's disease development: An up-to-date review. Eur J Pharmacol 2019; 856:172415. [PMID: 31132354 DOI: 10.1016/j.ejphar.2019.172415] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 04/26/2019] [Accepted: 05/23/2019] [Indexed: 12/25/2022]
Abstract
Alzheimer's disease (AD), which is predicted to affect 1 in 85 persons worldwide by 2050, results in progressive loss of neuronal functions, leading to impairments in memory and cognitive abilities. As being one of the major neuropathological hallmarks of AD, senile plaques mainly consist of amyloid-β (Aβ) peptides, which are derived from amyloid precursor protein (APP) via the sequential cleavage by β- and γ-secretases. Although the overproduction and accumulation of Aβ peptides are at the center of AD research, the new discoveries point out to the complexity of the disease development. In this respect, it is crucial to understand the processing and the trafficking of APP, the enzymes involved in its processing, the cleavage products and their therapeutic potentials. This review summarizes the salient features of APP processing focusing on APP, the canonical secretases as well as the novel secretases and the cleavage products with an update of the recent developments. We also discussed the intracellular trafficking of APP and secretases in addition to their potential in AD therapy.
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Affiliation(s)
- Melike Yuksel
- Department of Biochemistry, School of Pharmacy, Hacettepe University, 06100, Ankara, Turkey.
| | - Ozden Tacal
- Department of Biochemistry, School of Pharmacy, Hacettepe University, 06100, Ankara, Turkey.
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22
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Banerjee R, Rudloff Z, Naylor C, Yu MC, Gunawardena S. The presenilin loop region is essential for glycogen synthase kinase 3 β (GSK3β) mediated functions on motor proteins during axonal transport. Hum Mol Genet 2019; 27:2986-3001. [PMID: 29790963 DOI: 10.1093/hmg/ddy190] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/10/2018] [Indexed: 01/05/2023] Open
Abstract
Neurons require intracellular transport of essential components for function and viability and defects in transport has been implicated in many neurodegenerative diseases including Alzheimer's disease (AD). One possible mechanism by which transport defects could occur is by improper regulation of molecular motors. Previous work showed that reduction of presenilin (PS) or glycogen synthase kinase 3 beta (GSK3β) stimulated amyloid precursor protein vesicle motility. Excess GSK3β caused transport defects and increased motor binding to membranes, while reduction of PS decreased active GSK3β and motor binding to membranes. Here, we report that functional PS and the catalytic loop region of PS is essential for the rescue of GSK3β-mediated axonal transport defects. Disruption of PS loop (PSΔE9) or expression of the non-functional PS variant, PSD447A, failed to rescue axonal blockages in vivo. Further, active GSK3β associated with and phosphorylated kinesin-1 in vitro. Our observations together with previous work that showed that the loop region of PS interacts with GSK3β propose a scaffolding mechanism for PS in which the loop region sequesters GSK3β away from motors for the proper regulation of motor function. These findings are important to uncouple the complex regulatory mechanisms that likely exist for motor activity during axonal transport in vivo.
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Affiliation(s)
- Rupkatha Banerjee
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY 14260, USA
| | - Zoe Rudloff
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY 14260, USA
| | - Crystal Naylor
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY 14260, USA
| | - Michael C Yu
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY 14260, USA
| | - Shermali Gunawardena
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY 14260, USA
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23
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Imai S, Cai T, Yoshida C, Tomita T, Futai E. Specific mutations in presenilin 1 cause conformational changes in γ-secretase to modulate amyloid β trimming. J Biochem 2018; 165:37-46. [DOI: 10.1093/jb/mvy081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/04/2018] [Indexed: 01/08/2023] Open
Affiliation(s)
- So Imai
- Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramakiazaaoba, Aobaku, Sendai, Miyagi, Japan
| | - Tetsuo Cai
- Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Chika Yoshida
- Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramakiazaaoba, Aobaku, Sendai, Miyagi, Japan
| | - Taisuke Tomita
- Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Eugene Futai
- Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramakiazaaoba, Aobaku, Sendai, Miyagi, Japan
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24
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Stenovec M, Trkov Bobnar S, Smolič T, Kreft M, Parpura V, Zorec R. Presenilin PS1∆E9 disrupts mobility of secretory organelles in rat astrocytes. Acta Physiol (Oxf) 2018; 223:e13046. [PMID: 29392878 DOI: 10.1111/apha.13046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 01/17/2018] [Accepted: 01/25/2018] [Indexed: 12/14/2022]
Abstract
AIM Alzheimer's disease (AD) is largely considered a neuron-derived insult, but also involves failure of astroglia. A recent study indicated that mutated presenilin 1 (PS1M146V), a putative endoplasmic reticulum (ER) Ca2+ channel with decreased Ca2+ conductance, impairs the traffic of astroglial peptidergic vesicles. Whether other pathogenically relevant PS1 mutants, such as PS1ΔE9, which code for ER channel with putative increased Ca2+ conductance, similarly affect vesicle traffic, is unknown. METHODS Here, we cotransfected rat astrocytes with plasmids encoding mutant PS1ΔE9 and atrial natriuretic peptide or vesicular glutamate transporter 1 tagged with fluorescent proteins (pANP.emd or pVGLUT1-EGFP respectively), to microscopically examine whether alterations in vesicle mobility and Ca2+ -regulated release of gliosignalling molecules manifest as a general vesicle-based defect; control cells were transfected to co-express exogenous or native wild-type PS1 and pANP.emd or pVGLUT1-EGFP. The vesicle mobility was analysed at rest and after ATP stimulation that increased intracellular calcium activity. RESULTS In PS1ΔE9 astrocytes, spontaneous mobility of both vesicle types was reduced (P < .001) when compared to controls. Post-stimulatory recovery of fast vesicle mobility was hampered in PS1ΔE9 astrocytes. The ATP-evoked peptide release was less efficient in PS1ΔE9 astrocytes than in the controls (P < .05), as was the pre-stimulatory mobility of these vesicles. CONCLUSION Although the PS1 mutants PS1M146V and PS1ΔE9 differently affect ER Ca2+ conductance, our results revealed a common, vesicle-type indiscriminate trafficking defect in PS1ΔE9 astrocytes, indicating that reduced secretory vesicle-based signalling is a general deficit in AD astrocytes.
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Affiliation(s)
- M. Stenovec
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - S. Trkov Bobnar
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - T. Smolič
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - M. Kreft
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
- Biotechnical Faculty; CPAE; Department of Biology; University of Ljubljana; Ljubljana Slovenia
| | - V. Parpura
- Department of Neurobiology; Civitan International Research Center and Center for Glial Biology in Medicine; Evelyn F. McKnight Brain Institute; Atomic Force Microscopy & Nanotechnology Laboratories; University of Alabama at Birmingham; Birmingham AL USA
| | - R. Zorec
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
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25
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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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26
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Somavarapu AK, Kepp KP. Membrane Dynamics of γ-Secretase Provides a Molecular Basis for β-Amyloid Binding and Processing. ACS Chem Neurosci 2017; 8:2424-2436. [PMID: 28841371 DOI: 10.1021/acschemneuro.7b00208] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
γ-Secretase produces β-amyloid (Aβ) within its presenilin (PS1) subunit, mutations in which cause Alzheimer's disease, and current therapies thus seek to modulate its activity. While the general structure is known from recent electron microscopy studies, direct loop and membrane interactions and explicit dynamics relevant to substrate processing remain unknown. We report a modeled structure utilizing the optimal multitemplate information available, including loops and missing side chains, account of maturation cleavage, and explicit all-atom molecular dynamics in the membrane. We observe three distinct conformations of γ-secretase (open, semiopen, and closed) that remarkably differ by tilting of helices 2 and 3 of PS1, directly controlling active site availability. The large hydrophilic loop of PS1 where maturation occurs reveals a new helix segment that parallels the likely helix character of other substrates. The semiopen conformation consistently shows the best fit of Aβ peptides, that is, longer residence before release and by inference more trimming. In contrast, the closed, hydrophobic conformation is largely inactive and the open conformation is active but provides fewer optimal interactions and induces shorter residence time and by inference releases Aβ peptides of longer lengths. Our simulations thus provide a molecular basis for substrate processing and changes in the Aβ42/Aβ40 ratio. Accordingly, selective binding to protect the semiopen "innocent" conformation provides a molecular recipe for effective γ-secretase modulators; we provide the full atomic structures for these states that may play a key role in developing selective γ-secretase modulators for treatment of Alzheimer's disease.
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Affiliation(s)
| | - Kasper P. Kepp
- Technical University of Denmark, DTU Chemistry, DK-2800 Kongens Lyngby, Denmark
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27
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Oliveira J, Costa M, de Almeida MSC, da Cruz e Silva OA, Henriques AG. Protein Phosphorylation is a Key Mechanism in Alzheimer’s Disease. J Alzheimers Dis 2017; 58:953-978. [DOI: 10.3233/jad-170176] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Joana Oliveira
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Márcio Costa
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | | | - Odete A.B. da Cruz e Silva
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ana Gabriela Henriques
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
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28
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Grigorenko AP, Moliaka YK, Plotnikova OV, Smirnov A, Nikishina VA, Goltsov AY, Gusev F, Andreeva TV, Nelson O, Bezprozvanny I, Rogaev EI. Mutational re-modeling of di-aspartyl intramembrane proteases: uncoupling physiologically-relevant activities from those associated with Alzheimer's disease. Oncotarget 2017; 8:82006-82026. [PMID: 29137240 PMCID: PMC5669866 DOI: 10.18632/oncotarget.18299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 04/28/2017] [Indexed: 12/18/2022] Open
Abstract
The intramembrane proteolytic activities of presenilins (PSEN1/PS1 and PSEN2/PS2) underlie production of β-amyloid, the key process in Alzheimer’s disease (AD). Dysregulation of presenilin-mediated signaling is linked to cancers. Inhibition of the γ-cleavage activities of PSENs that produce Aβ, but not the ε-like cleavage activity that release physiologically essential transcription activators, is a potential approach for the development of rational therapies for AD. In order to identify whether different activities of PSEN1 can be dissociated, we designed multiple mutations in the evolutionary conserved sites of PSEN1. We tested them in vitro and in vivo assays and compared their activities with mutant isoforms of presenilin-related intramembrane di-aspartyl protease (IMPAS1 (IMP1)/signal peptide peptidase (SPP)). PSEN1 auto-cleavage was more resistant to the mutation remodeling than the ε-like proteolysis. PSEN1 with a G382A or a P433A mutation in evolutionary invariant sites retains functionally important APP ε- and Notch S3- cleavage activities, but G382A inhibits APP γ-cleavage and Aβ production and a P433A elevates Aβ. The G382A variant cannot restore the normal cellular ER Ca2+ leak in PSEN1/PSEN2 double knockout cells, but efficiently rescues the loss-of-function (Egl) phenotype of presenilin in C. elegans. We found that, unlike in PSEN1 knockout cells, endoplasmic reticulum (ER) Ca2+ leak is not changed in the absence of IMP1/SPP. IMP1/SPP with the analogous mutations retained efficiency in cleavage of transmembrane substrates and rescued the lethality of Ce-imp-2 knockouts. In summary, our data show that mutations near the active catalytic sites of intramembrane di-aspartyl proteases have different consequences on proteolytic and signaling functions.
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Affiliation(s)
- Anastasia P Grigorenko
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA.,Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Youri K Moliaka
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Olga V Plotnikova
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Alexander Smirnov
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Vera A Nikishina
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Andrey Y Goltsov
- Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Fedor Gusev
- Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Tatiana V Andreeva
- Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Omar Nelson
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9040, USA
| | - Ilya Bezprozvanny
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9040, USA
| | - Evgeny I Rogaev
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA.,Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.,Center for Genetics and Genetic Technologies, Faculty of Biology, Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119234, Russia
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29
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Lou F, Luo X, Li M, Ren Y, He Z. Very early–onset sporadic Alzheimer's disease with a de novo mutation in the PSEN1 gene. Neurobiol Aging 2017; 53:193.e1-193.e5. [DOI: 10.1016/j.neurobiolaging.2016.12.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/11/2016] [Accepted: 12/27/2016] [Indexed: 12/31/2022]
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30
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Dynamic Nature of presenilin1/γ-Secretase: Implication for Alzheimer's Disease Pathogenesis. Mol Neurobiol 2017; 55:2275-2284. [PMID: 28332150 DOI: 10.1007/s12035-017-0487-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/12/2017] [Indexed: 12/27/2022]
Abstract
Presenilin 1 (PS1) is a catalytic component of the γ-secretase complex, responsible for the intramembraneous cleavage of more than 90 type I transmembrane proteins, including Alzheimer's disease (AD)-related amyloid precursor protein (APP). The γ-secretase-mediated cleavage of the APP C-terminal membrane stub leads to the production of various amyloid β (Aβ) species. The assembly of Aβ into neurotoxic oligomers, which causes synaptic dysfunction and neurodegeneration, is influenced by the relative ratio of the longer (Aβ42/43) to shorter Aβ (Aβ40) peptides. The ratio of Aβ42 to Aβ40 depends on the conformation and activity of the PS1/γ-secretase enzymatic complex. The latter exists in a dynamic equilibrium of the so called "closed" and "open" conformational states, as determined by the Förster resonance energy transfer (FRET)-based PS1 conformation assay. Here we review several factors that can allosterically influence conformational status of the enzyme, and hence the production of Aβ peptides. These include genetic variations in PS1, APP and other γ-secretase components, environmental stressors implicated in AD pathogenesis and pharmacological agents. Since "closed" PS1 conformation is the common outcome of many AD-related insults, the novel assays monitoring PS1 conformation in live/intact cells in vivo and in vitro might be utilized for diagnostic purposes and for validation of the potential therapeutic approaches.
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Cerebrospinal fluid Presenilin-1 increases at asymptomatic stage in genetically determined Alzheimer's disease. Mol Neurodegener 2016; 11:66. [PMID: 27686161 PMCID: PMC5043603 DOI: 10.1186/s13024-016-0131-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 09/22/2016] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Presenilin-1 (PS1), the active component of the intramembrane γ-secretase complex, can be detected as soluble heteromeric aggregates in cerebrospinal fluid (CSF). The aim of this study was to examine the different soluble PS1 complexes in the lumbar CSF (CSF-PS1) of individuals with Alzheimer's disease (AD), particularly in both symptomatic and asymptomatic genetically determined AD, in order to evaluate their potential as early biomarkers. METHODS Western blotting, differential centrifugation and co-immunoprecipitation served to determine and characterize CSF-PS1 complexes. We also monitored the assembly of soluble PS1 into complexes in a cell model, and the participation of Aβ in the dynamics and robustness of the stable PS1 complexes. RESULTS There was an age-dependent increase in CSF-PS1 levels in cognitively normal controls, the different complexes represented in similar proportions. The total levels of CSF-PS1, and in particular the proportion of the stable 100-150 kDa complexes, increased in subjects with autosomal dominant AD that carried PSEN1 mutations (eight symptomatic and six asymptomatic ADAD) and in Down syndrome individuals (ten demented and ten non-demented DS), compared with age-matched controls (n = 23), even prior to the appearance of symptoms of dementia. The proportion of stable CSF-PS1 complexes also increased in sporadic AD (n = 13) and mild-cognitive impaired subjects (n = 12), relative to age-matched controls (n = 17). Co-immunoprecipitation demonstrated the association of Aβ oligomers with soluble PS1 complexes, particularly the stable complexes. CONCLUSIONS Our data suggest that CSF-PS1 complexes may be useful as an early biomarker for AD, reflecting the pathology at asymptomatic state.
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Kepp KP. Alzheimer's disease due to loss of function: A new synthesis of the available data. Prog Neurobiol 2016; 143:36-60. [PMID: 27327400 DOI: 10.1016/j.pneurobio.2016.06.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/10/2016] [Accepted: 06/11/2016] [Indexed: 12/11/2022]
Abstract
Alzheimer's Disease (AD) is a highly complex disease involving a broad range of clinical, cellular, and biochemical manifestations that are currently not understood in combination. This has led to many views of AD, e.g. the amyloid, tau, presenilin, oxidative stress, and metal hypotheses. The amyloid hypothesis has dominated the field with its assumption that buildup of pathogenic β-amyloid (Aβ) peptide causes disease. This paradigm has been criticized, yet most data suggest that Aβ plays a key role in the disease. Here, a new loss-of-function hypothesis is synthesized that accounts for the anomalies of the amyloid hypothesis, e.g. the curious pathogenicity of the Aβ42/Aβ40 ratio, the loss of Aβ caused by presenilin mutation, the mixed phenotypes of APP mutations, the poor clinical-biochemical correlations for genetic variant carriers, and the failure of Aβ reducing drugs. The amyloid-loss view accounts for recent findings on the structure and chemical features of Aβ variants and their coupling to human patient data. The lost normal function of APP/Aβ is argued to be metal transport across neuronal membranes, a view with no apparent anomalies and substantially more explanatory power than the gain-of-function amyloid hypothesis. In the loss-of-function scenario, the central event of Aβ aggregation is interpreted as a loss of soluble, functional monomer Aβ rather than toxic overload of oligomers. Accordingly, new research models and treatment strategies should focus on remediation of the functional amyloid balance, rather than strict containment of Aβ, which, for reasons rationalized in this review, has failed clinically.
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Affiliation(s)
- Kasper P Kepp
- Technical University of Denmark, DTU Chemistry, DK-2800 Kongens Lyngby, Denmark.
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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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Somavarapu AK, Kepp KP. The dynamic mechanism of presenilin-1 function: Sensitive gate dynamics and loop unplugging control protein access. Neurobiol Dis 2016; 89:147-56. [PMID: 26852951 DOI: 10.1016/j.nbd.2016.02.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 02/02/2016] [Accepted: 02/03/2016] [Indexed: 12/20/2022] Open
Abstract
There is no molecular explanation for the many presenilin 1 (PSEN1) mutations causing Alzheimer's disease, but both gain of function relating to amyloid production and loss of isolated PSEN1 function have been implied. We report here the first detailed dynamic all-atom model of mature PSEN1 from molecular dynamics in an explicit membrane with particular account of the as yet unexplored loop dynamics. We find that mature PSEN1 contains multiple distinct conformational states whereas non-mature PSEN1 is a typical one-state protein. We confirm a previously suggested gating mechanism, and find that the 106-131 loop acts as a "hinge" for the TM2 and TM6 "doors". More importantly, we identify an unplugging mechanism of the Exon 9 loop associated only with mature PSEN1. Proper opening of both the "gate" and "plug" in the membrane produces channel-like morphologies and access to the catalytic aspartates. Dynamically, these features seem linked. The long-range sensitivity of this gate-plug system to subtle conformational changes can explain why so many PSEN1 mutants cause disease. Reduced access and imprecise substrate cleavage associated with impaired gate-plug dynamics is directly illustrated by the effect of maturation in our work and could explain the overall reduction in Aβ levels upon PSEN1 mutation and the increase in the Aβ 42/40 ratio. Yet, our PSEN1-only dynamics are particularly insightful in revealing PSEN1-only dynamics relating to e.g. its role as membrane channel. Thus, our identified gate-plug mechanism is relevant for designing PSEN1 modulating therapies for treatment of Alzheimer's disease within both the amyloid/γ-secretase hypothesis and within the PSEN1 loss of function paradigm.
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Affiliation(s)
| | - Kasper P Kepp
- Technical University of Denmark, DTU Chemistry, DK-2800 Kongens Lyngby, Denmark.
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Structural biology of intramembrane proteases: mechanistic insights from rhomboid and S2P to γ-secretase. Curr Opin Struct Biol 2016; 37:97-107. [PMID: 26811996 DOI: 10.1016/j.sbi.2015.12.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/14/2015] [Accepted: 12/28/2015] [Indexed: 12/21/2022]
Abstract
Intramembrane proteases catalyze hydrolysis of peptide bond within the lipid bilayer and play a key role in a variety of cellular processes. These membrane-embedded enzymes comprise four major classes: rhomboid serine proteases, site-2 metalloproteases, Rce1-type glutamyl proteases, and aspartyl proteases exemplified by signal peptide peptidase and γ-secretase. In the past several years, three-dimensional structures of representative members of these four classes of intramembrane protease have been reported at atomic resolutions, which reveal distinct protein folds and active site configurations. These structures, together with structure-guided biochemical analyses, shed light on the working mechanisms of water access and substrate entry. In this review, we discuss the shared as well as unique features of these intramembrane proteases, with a focus on presenilin-the catalytic component of γ-secretase.
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36
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Futai E, Osawa S, Cai T, Fujisawa T, Ishiura S, Tomita T. Suppressor Mutations for Presenilin 1 Familial Alzheimer Disease Mutants Modulate γ-Secretase Activities. J Biol Chem 2016; 291:435-46. [PMID: 26559975 PMCID: PMC4697183 DOI: 10.1074/jbc.m114.629287] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 11/07/2015] [Indexed: 12/27/2022] Open
Abstract
γ-Secretase is a multisubunit membrane protein complex containing presenilin (PS1) as a catalytic subunit. Familial Alzheimer disease (FAD) mutations within PS1 were analyzed in yeast cells artificially expressing membrane-bound substrate, amyloid precursor protein, or Notch fused to Gal4 transcriptional activator. The FAD mutations, L166P and G384A (Leu-166 to Pro and Gly-384 to Ala substitution, respectively), were loss-of-function in yeast. We identified five amino acid substitutions that suppress the FAD mutations. The cleavage of amyloid precursor protein or Notch was recovered by the secondary mutations. We also found that secondary mutations alone activated the γ-secretase activity. FAD mutants with suppressor mutations, L432M or S438P within TMD9 together with a missense mutation in the second or sixth loops, regained γ-secretase activity when introduced into presenilin null mouse fibroblasts. Notably, the cells with suppressor mutants produced a decreased amount of Aβ42, which is responsible for Alzheimer disease. These results indicate that the yeast system is useful to screen for mutations and chemicals that modulate γ-secretase activity.
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Affiliation(s)
- Eugene Futai
- From the Department of Molecular and Cell Biology, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Miyagi 981-8555, the Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902,
| | - Satoko Osawa
- the Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences and
| | - Tetsuo Cai
- the Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences and Laboratory of Neuropathology and Neuroscience, Faculty of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomoya Fujisawa
- From the Department of Molecular and Cell Biology, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Miyagi 981-8555
| | - Shoichi Ishiura
- the Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902
| | - Taisuke Tomita
- the Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences and Laboratory of Neuropathology and Neuroscience, Faculty of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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Chang X, Cao G, Wang K, Zhang X, Dou F. Application of intra-molecular fluorescence complementation in the topology examination of polytopic proteins in living cells. Acta Biochim Biophys Sin (Shanghai) 2015; 47:654-6. [PMID: 26058581 DOI: 10.1093/abbs/gmv048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Xingya Chang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing 100875, China Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China
| | - Guang Cao
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing 100875, China Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China
| | - Kun Wang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing 100875, China Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China
| | - Xiaoyan Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing 100875, China Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China
| | - Fei Dou
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing 100875, China Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China
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38
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Midde K, Rich R, Saxena A, Gryczynski I, Borejdo J, Das HK. Membrane topology of human presenilin-1 in SK-N-SH cells determined by fluorescence correlation spectroscopy and fluorescent energy transfer. Cell Biochem Biophys 2015; 70:923-32. [PMID: 24839116 DOI: 10.1007/s12013-014-9999-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Presenilin-1 (PS1) protein acts as passive ER Ca(2+) leak channels that facilitate passive Ca(2+) leak across ER membrane. Mutations in the gene encoding PS1 protein cause neurodegeneration in the brains of patients with familial Alzheimer's disease (FAD). FADPS1 mutations abrogate the function of ER Ca(2+) leak channel activity in human neuroblastoma SK-N-SH cells in vitro (Das et al., J Neurochem 122(3):487-500, 2012) and in mouse embryonic fibroblasts. Consequently, genetic deletion or mutations of the PS1 gene cause calcium (Ca(2+)) signaling abnormalities leading to neurodegeneration in FAD patients. By analogy with other known ion channels it has been proposed that the functional PS1 channels in ER may be multimers of several PS1 subunits. To test this hypothesis, we conjugated the human PS1 protein with an NH2-terminal YFP-tag and a COOH-terminal CFP-tag. As expected YFP-PS1, and PS1-CFP were found to be expressed on the plasma membranes by TIRF microscopy, and both these fusion proteins increased ER Ca(2+) leak channel activity similar to PS1 (WT) in SK-N-SH cells, as determined by functional calcium imaging. PS1-CFP was either expressed alone or together with YFP-PS1 into SK-N-SH cell line and the interaction between YFP-PS1 and PS1-CFP was determined by Förster resonance energy transfer analysis. Our results suggest interaction between YFP-PS1 and PS1-CFP confirming the presence of a dimeric or multimeric form of PS1 in SK-N-SH cells. Lateral diffusion of PS1-CFP and YFP-PS1 in the plasma membrane of SK-N-SH cells was measured in the absence or in the presence of glycerol by fluorescence correlation spectroscopy to show that both COOH-terminal and NH2-terminal of human PS1 are located on the cytoplasmic side of the plasma membrane. Therefore, we conclude that both COOH-terminal and NH2-terminal of human PS1 may also be oriented on the cytosolic side of ER membrane.
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Affiliation(s)
- Krishna Midde
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, UNT Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
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Efimova SS, Zakharov VV, Ostroumova OS. Effects of dipole modifiers on channel-forming activity of amyloid and amyloid-like peptides in lipid bilayers. ACTA ACUST UNITED AC 2015. [DOI: 10.1134/s1990519x15030049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Lopez-Font I, Cuchillo-Ibañez I, Sogorb-Esteve A, García-Ayllón MS, Sáez-Valero J. Transmembrane Amyloid-Related Proteins in CSF as Potential Biomarkers for Alzheimer's Disease. Front Neurol 2015; 6:125. [PMID: 26082753 PMCID: PMC4451586 DOI: 10.3389/fneur.2015.00125] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 05/17/2015] [Indexed: 02/04/2023] Open
Abstract
In the continuing search for new cerebrospinal fluid (CSF) biomarkers for Alzheimer’s disease (AD), reasonable candidates are the secretase enzymes involved in the processing of the amyloid precursor protein (APP), as well as the large proteolytic cleavage fragments sAPPα and sAPPβ. The enzymatic activities of some of these secretases, such as BACE1 and TACE, have been investigated as potential AD biomarkers, and it has been assumed that these activities present in human CSF result from the soluble truncated forms of the membrane-bound enzymes. However, we and others recently identified soluble forms of BACE1 and APP in CSF containing the intracellular domains, as well as the multi-pass transmembrane presenilin-1 (PS1) and other subunits of γ-secretase. We also review recent findings that suggest that most of these soluble transmembrane proteins could display self-association properties based on hydrophobic and/or ionic interactions leading to the formation of heteromeric complexes. The oligomerization state of these potential new biomarkers needs to be taken into consideration for assessing their real potential as CSF biomarkers for AD by adequate molecular tools.
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Affiliation(s)
- Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC , Sant Joan d'Alacant , Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Sant Joan d'Alacant , Spain
| | - Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC , Sant Joan d'Alacant , Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Sant Joan d'Alacant , Spain
| | - Aitana Sogorb-Esteve
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC , Sant Joan d'Alacant , Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Sant Joan d'Alacant , Spain
| | - María-Salud García-Ayllón
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC , Sant Joan d'Alacant , Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Sant Joan d'Alacant , Spain ; Unidad de Investigación, Fundación para el Fomento de la Investigación Sanitaria Biomédica de la Comunidad Valenciana (FISABIO), Hospital General Universitario de Elche , Elche , Spain
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC , Sant Joan d'Alacant , Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Sant Joan d'Alacant , Spain
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Dewji NN, Singer SJ, Masliah E, Rockenstein E, Kim M, Harber M, Horwood T. Peptides of presenilin-1 bind the amyloid precursor protein ectodomain and offer a novel and specific therapeutic approach to reduce ß-amyloid in Alzheimer's disease. PLoS One 2015; 10:e0122451. [PMID: 25923432 PMCID: PMC4414571 DOI: 10.1371/journal.pone.0122451] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 02/12/2015] [Indexed: 12/19/2022] Open
Abstract
β-Amyloid (Aβ) accumulation in the brain is widely accepted to be critical to the development of Alzheimer's disease (AD). Current efforts at reducing toxic Aβ40 or 42 have largely focused on modulating γ-secretase activity to produce shorter, less toxic Aβ, while attempting to spare other secretase functions. In this paper we provide data that offer the potential for a new approach for the treatment of AD. The method is based on our previous findings that the production of Aβ from the interaction between the β-amyloid precursor protein (APP) and Presenilin (PS), as part of the γ-secretase complex, in cell culture is largely inhibited if the entire water-soluble NH2-terminal domain of PS is first added to the culture. Here we demonstrate that two small, non-overlapping water-soluble peptides from the PS-1 NH2-terminal domain can substantially and specifically inhibit the production of total Aβ as well as Aβ40 and 42 in vitro and in vivo in the brains of APP transgenic mice. These results suggest that the inhibitory activity of the entire amino terminal domain of PS-1 on Aβ production is largely focused in a few smaller sequences within that domain. Using biolayer interferometry and confocal microscopy we provide evidence that peptides effective in reducing Aβ give a strong, specific and biologically relevant binding with the purified ectodomain of APP 695. Finally, we demonstrate that the reduction of Aβ by the peptides does not affect the catalytic activities of β- or γ-secretase, or the level of APP. P4 and P8 are the first reported protein site-specific small peptides to reduce Aβ production in model systems of AD. These peptides and their derivatives offer new potential drug candidates for the treatment of AD.
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Affiliation(s)
- Nazneen N. Dewji
- Department of Medicine, University of California San Diego, La Jolla, CA, 92093, United States of America
- Cenna Biosciences Incorporated, 505 Coast Boulevard, Suite 302, La Jolla, CA, 92037, United States of America
- * E-mail:
| | - S. Jonathan Singer
- Department of Biology, University of California San Diego, La Jolla, CA, 92093, United States of America
- Cenna Biosciences Incorporated, 505 Coast Boulevard, Suite 302, La Jolla, CA, 92037, United States of America
| | - Eliezer Masliah
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, United States of America
- Department of Pathology, University of California San Diego, La Jolla, CA, 92093, United States of America
| | - Edward Rockenstein
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, United States of America
| | - Mihyun Kim
- Department of Medicine, University of California San Diego, La Jolla, CA, 92093, United States of America
- Cenna Biosciences Incorporated, 505 Coast Boulevard, Suite 302, La Jolla, CA, 92037, United States of America
| | - Martha Harber
- FortéBio, Pall Corporation, 1360 Willow Rd, Suite 201, Menlo Park, CA, 94025, United States of America
| | - Taylor Horwood
- Department of Neuroscience Imaging Core, University of California San Diego, La Jolla, CA, 92093, United States of America
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Hyun SI, Maruri-Avidal L, Moss B. Topology of Endoplasmic Reticulum-Associated Cellular and Viral Proteins Determined with Split-GFP. Traffic 2015; 16:787-95. [PMID: 25761760 DOI: 10.1111/tra.12281] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/04/2015] [Accepted: 03/09/2015] [Indexed: 12/01/2022]
Abstract
The split green fluorescent protein (GFP) system was adapted for investigation of the topology of ER-associated proteins. A 215-amino acid fragment of GFP (S1-10) was expressed in the cytoplasm as a free protein or fused to the N-terminus of calnexin and in the ER as an intraluminal protein or fused to the C-terminus of calnexin. A 16-amino acid fragment of GFP (S11) was fused to the N- or C-terminus of the target protein. Fluorescence occurred when both GFP fragments were in the same intracellular compartment. After validation with the cellular proteins PDI and tapasin, we investigated two vaccinia virus proteins (L2 and A30.5) of unknown topology that localize to the ER and are required for assembly of the viral membrane. Our results indicated that the N- and C-termini of L2 faced the cytoplasmic and luminal sides of the ER, respectively. In contrast both the N- and C-termini of A30.5 faced the cytoplasm. The system offers advantages for quickly determining the topology of intracellular proteins: the S11 tag is similar in length to commonly used epitope tags; multiple options are available for detecting fluorescence in live or fixed cells; transfection protocols are adaptable to numerous expression systems and can enable high throughput applications.
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Affiliation(s)
- Seong-In Hyun
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Liliana Maruri-Avidal
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Bernard Moss
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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Matz A, Halamoda-Kenzaoui B, Hamelin R, Mosser S, Alattia JR, Dimitrov M, Moniatte M, Fraering PC. Identification of new Presenilin-1 phosphosites: implication for γ-secretase activity and Aβ production. J Neurochem 2015; 133:409-21. [PMID: 25458374 DOI: 10.1111/jnc.12996] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 11/02/2014] [Accepted: 11/10/2014] [Indexed: 02/02/2023]
Abstract
An important pathological hallmark of Alzheimer's disease (AD) is the deposition of amyloid-beta (Aβ) peptides in the brain parenchyma, leading to neuronal death and impaired learning and memory. The protease γ-secretase is responsible for the intramembrane proteolysis of the amyloid-β precursor protein (APP), which leads to the production of the toxic Aβ peptides. Thus, an attractive therapeutic strategy to treat AD is the modulation of the γ-secretase activity, to reduce Aβ42 production. Because phosphorylation of proteins is a post-translational modification known to modulate the activity of many different enzymes, we used electrospray (LC-MS/MS) mass spectrometry to identify new phosphosites on highly purified human γ-secretase. We identified 11 new single or double phosphosites in two well-defined domains of Presenilin-1 (PS1), the catalytic subunit of the γ-secretase complex. Next, mutagenesis and biochemical approaches were used to investigate the role of each phosphosite in the maturation and activity of γ-secretase. Together, our results suggest that the newly identified phosphorylation sites in PS1 do not modulate γ-secretase activity and the production of the Alzheimer's Aβ peptides. Individual PS1 phosphosites shall probably not be considered therapeutic targets for reducing cerebral Aβ plaque formation in AD. In this study, we identified 11 new phosphosites in Presenilin-1 (PS1), the catalytic subunit of the Alzheimer's γ-secretase complex. By combining a mutagenesis approach with cell-based and cell-free γ-secretase assays, we demonstrate that the new phosphosites do not modulate the maturation and activity of γ-secretase. Individual PS1 phosphosites shall thus not be considered therapeutic targets for reducing cerebral Aβ plaque formation in Alzheimer's Disease. Aβ, amyloid beta.
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Affiliation(s)
- Alexandre Matz
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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Marinangeli C, Tasiaux B, Opsomer R, Hage S, Sodero AO, Dewachter I, Octave JN, Smith SO, Constantinescu SN, Kienlen-Campard P. Presenilin transmembrane domain 8 conserved AXXXAXXXG motifs are required for the activity of the γ-secretase complex. J Biol Chem 2015; 290:7169-84. [PMID: 25614624 DOI: 10.1074/jbc.m114.601286] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Understanding the molecular mechanisms controlling the physiological and pathological activity of γ-secretase represents a challenging task in Alzheimer disease research. The assembly and proteolytic activity of this enzyme require the correct interaction of the 19 transmembrane domains (TMDs) present in its four subunits, including presenilin (PS1 or PS2), the γ-secretase catalytic core. GXXXG and GXXXG-like motifs are critical for TMDs interactions as well as for protein folding and assembly. The GXXXG motifs on γ-secretase subunits (e.g. APH-1) or on γ-secretase substrates (e.g. APP) are known to be involved in γ-secretase assembly and in Aβ peptide production, respectively. We identified on PS1 and PS2 TMD8 two highly conserved AXXXAXXXG motifs. The presence of a mutation causing an inherited form of Alzheimer disease (familial Alzheimer disease) in the PS1 motif suggested their involvement in the physiopathological configuration of the γ-secretase complex. In this study, we targeted the role of these motifs on TMD8 of PSs, focusing on their role in PS assembly and catalytic activity. Each motif was mutated, and the impact on complex assembly, activity, and substrate docking was monitored. Different amino acid substitutions on the same motif resulted in opposite effects on γ-secretase activity, without affecting the assembly or significantly impairing the maturation of the complex. Our data suggest that AXXXAXXXG motifs in PS TMD8 are key determinants for the conformation of the mature γ-secretase complex, participating in the switch between the physiological and pathological functional conformations of the γ-secretase.
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Affiliation(s)
| | | | | | - Salim Hage
- the Louvain Drug Research Institute, and
| | | | | | | | - Steven O Smith
- the Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794-5215
| | - Stefan N Constantinescu
- the de Duve Institute and Ludwig Institute for Cancer Research, Université Catholique de Louvain, Brussels 1200, Belgium and
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Li Y, Bohm C, Dodd R, Chen F, Qamar S, Schmitt-Ulms G, Fraser PE, St George-Hyslop PH. Structural biology of presenilin 1 complexes. Mol Neurodegener 2014; 9:59. [PMID: 25523933 PMCID: PMC4326451 DOI: 10.1186/1750-1326-9-59] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 12/12/2014] [Indexed: 11/17/2022] Open
Abstract
The presenilin genes were first identified as the site of missense mutations causing early onset autosomal dominant familial Alzheimer's disease. Subsequent work has shown that the presenilin proteins are the catalytic subunits of a hetero-tetrameric complex containing APH1, nicastrin and PEN-2. This complex (variously termed presenilin complex or gamma-secretase complex) performs an unusual type of proteolysis in which the transmembrane domains of Type I proteins are cleaved within the hydrophobic compartment of the membrane. This review describes some of the molecular and structural biology of this unusual enzyme complex. The presenilin complex is a bilobed structure. The head domain contains the ectodomain of nicastrin. The base domain contains a central cavity with a lateral cleft that likely provides the route for access of the substrate to the catalytic cavity within the centre of the base domain. There are reciprocal allosteric interactions between various sites in the complex that affect its function. For instance, binding of Compound E, a peptidomimetic inhibitor to the PS1 N-terminus, induces significant conformational changes that reduces substrate binding at the initial substrate docking site, and thus inhibits substrate cleavage. However, there is a reciprocal allosteric interaction between these sites such that prior binding of the substrate to the initial docking site paradoxically increases the binding of the Compound E peptidomimetic inhibitor. Such reciprocal interactions are likely to form the basis of a gating mechanism that underlies access of substrate to the catalytic site. An increasingly detailed understanding of the structural biology of the presenilin complex is an essential step towards rational design of substrate- and/or cleavage site-specific modulators of presenilin complex function.
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Affiliation(s)
| | | | | | | | | | | | | | - Peter H St George-Hyslop
- Cambridge Institute for Medical Research, Wellcome Trust MRC Building, Addenbrookes Hospital, Hills Road, Cambridge CB2 0XY, UK.
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Zhang X, Li Y, Xu H, Zhang YW. The γ-secretase complex: from structure to function. Front Cell Neurosci 2014; 8:427. [PMID: 25565961 PMCID: PMC4263104 DOI: 10.3389/fncel.2014.00427] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 11/27/2014] [Indexed: 12/21/2022] Open
Abstract
One of the most critical pathological features of Alzheimer’s disease (AD) is the accumulation of β-amyloid (Aβ) peptides that form extracellular senile plaques in the brain. Aβ is derived from β-amyloid precursor protein (APP) through sequential cleavage by β- and γ-secretases. γ-secretase is a high molecular weight complex minimally composed of four components: presenilins (PS), nicastrin, anterior pharynx defective 1 (APH-1), and presenilin enhancer 2 (PEN-2). In addition to APP, γ-secretase also cleaves many other type I transmembrane (TM) protein substrates. As a crucial enzyme for Aβ production, γ-secretase is an appealing therapeutic target for AD. Here, we summarize current knowledge on the structure and function of γ-secretase, as well as recent progress in developing γ-secretase targeting drugs for AD treatment.
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Affiliation(s)
- Xian Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China
| | - Yanfang Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China ; Degenerative Disease Research Program, Sanford-Burnham Medical Research Institute La Jolla, CA, USA
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China
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Ma F, Liu D. 17β-trenbolone, an anabolic-androgenic steroid as well as an environmental hormone, contributes to neurodegeneration. Toxicol Appl Pharmacol 2014; 282:68-76. [PMID: 25461682 DOI: 10.1016/j.taap.2014.11.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 11/12/2014] [Accepted: 11/17/2014] [Indexed: 01/17/2023]
Abstract
Both genetic and environmental factors contribute to neurodegenerative disorders. In a large number of neurodegenerative diseases (for example, Alzheimer's disease (AD)), patients do not carry the mutant genes. Other risk factors, for example the environmental factors, should be evaluated. 17β-trenbolone is a kind of environmental hormone as well as an anabolic-androgenic steroid. 17β-trenbolone is used as a growth promoter for livestock in the USA. Also, a large portion of recreational exercisers inject 17β-trenbolone in large doses and for very long time to increase muscle and strength. 17β-trenbolone is stable in the environment after being excreted. In the present study, 17β-trenbolone was administered to adult and pregnant rats and the primary hippocampal neurons. 17β-trenbolone's distribution and its effects on serum hormone levels and Aβ42 accumulation in vivo and its effects on AD related parameters in vitro were assessed. 17β-trenbolone accumulated in adult rat brain, especially in the hippocampus, and in the fetus brain. It altered Aβ42 accumulation. 17β-trenbolone induced apoptosis of primary hippocampal neurons in vitro and resisted neuroprotective function of testosterone. Presenilin-1 protein expression was down-regulated while β-amyloid peptide 42 (Aβ42) production and caspase-3 activities were increased. Both androgen and estrogen receptors mediated the processes. 17β-trenbolone played critical roles in neurodegeneration. Exercisers who inject large doses of trenbolone and common people who are exposed to 17β-trenbolone by various ways are all influenced chronically and continually. Identification of such environmental risk factors will help us take early prevention measure to slow down the onset of neurodegenerative disorders.
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Affiliation(s)
- Fucui Ma
- Wenzhou Institute of Biomaterials and Engineering, No. 16 Xinshan Road, Hi-tech Industry Park, Wenzhou, PR China; Key Laboratory of Animal Resistance, College of Life Science, Shandong Normal University, 88 East Wenhua Road, Jinan 250014, PR China.
| | - Daicheng Liu
- Key Laboratory of Animal Resistance, College of Life Science, Shandong Normal University, 88 East Wenhua Road, Jinan 250014, PR China.
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Wang X, Huang T, Zhao Y, Zheng Q, Thompson RC, Bu G, Zhang YW, Hong W, Xu H. Sorting nexin 27 regulates Aβ production through modulating γ-secretase activity. Cell Rep 2014; 9:1023-33. [PMID: 25437557 DOI: 10.1016/j.celrep.2014.09.037] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 08/04/2014] [Accepted: 09/18/2014] [Indexed: 12/14/2022] Open
Abstract
Patients with Down syndrome (DS) invariably develop Alzheimer's disease (AD) pathology in their 40s. We have recently found that overexpression of a chromosome 21-encoded microRNA-155 results in decreased levels of the membrane trafficking component, SNX27, diminishing glutamate receptor recycling and thereby impairing synaptic functions in DS. Here, we report a function of SNX27 in regulating β-amyloid (Aβ) generation by modulating γ-secretase activity. Downregulation of SNX27 using RNAi increased Aβ production, whereas overexpression of full-length SNX27, but not SNX27ΔPDZ, reversed the RNAi-mediated Aβ elevation. Moreover, genetic deletion of Snx27 promoted Aβ production and neuronal loss, whereas overexpression of SNX27 using an adeno-associated viral (AAV) vector reduced hippocampal Aβ levels in a transgenic AD mouse model. SNX27 associates with the γ-secretase complex subunit presenilin 1; this interaction dissociates the γ-secretase complex, thus decreasing its proteolytic activity. Our study establishes a molecular mechanism for Aβ-dependent pathogenesis in both DS and AD.
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Affiliation(s)
- Xin Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361005, China; Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Timothy Huang
- Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Yingjun Zhao
- Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Qiuyang Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361005, China; Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Robert C Thompson
- Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Guojun Bu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361005, China
| | - Yun-wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361005, China; Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Wanjin Hong
- Institute for Biomedical Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen 361005, China; Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673, Singapore
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361005, China; Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA.
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Jiao B, Tang B, Liu X, Xu J, Wang Y, Zhou L, Zhang F, Yan X, Zhou Y, Shen L. Mutational analysis in early-onset familial Alzheimer's disease in Mainland China. Neurobiol Aging 2014; 35:1957.e1-6. [DOI: 10.1016/j.neurobiolaging.2014.02.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 02/07/2014] [Accepted: 02/16/2014] [Indexed: 11/29/2022]
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Reddy A, Cho J, Ling S, Reddy V, Shlykov M, Saier MH. Reliability of nine programs of topological predictions and their application to integral membrane channel and carrier proteins. J Mol Microbiol Biotechnol 2014; 24:161-90. [PMID: 24992992 DOI: 10.1159/000363506] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We evaluated topological predictions for nine different programs, HMMTOP, TMHMM, SVMTOP, DAS, SOSUI, TOPCONS, PHOBIUS, MEMSAT-SVM (hereinafter referred to as MEMSAT), and SPOCTOPUS. These programs were first evaluated using four large topologically well-defined families of secondary transporters, and the three best programs were further evaluated using topologically more diverse families of channels and carriers. In the initial studies, the order of accuracy was: SPOCTOPUS > MEMSAT > HMMTOP > TOPCONS > PHOBIUS > TMHMM > SVMTOP > DAS > SOSUI. Some families, such as the Sugar Porter Family (2.A.1.1) of the Major Facilitator Superfamily (MFS; TC #2.A.1) and the Amino Acid/Polyamine/Organocation (APC) Family (TC #2.A.3), were correctly predicted with high accuracy while others, such as the Mitochondrial Carrier (MC) (TC #2.A.29) and the K(+) transporter (Trk) families (TC #2.A.38), were predicted with much lower accuracy. For small, topologically homogeneous families, SPOCTOPUS and MEMSAT were generally most reliable, while with large, more diverse superfamilies, HMMTOP often proved to have the greatest prediction accuracy. We next developed a novel program, TM-STATS, that tabulates HMMTOP, SPOCTOPUS or MEMSAT-based topological predictions for any subdivision (class, subclass, superfamily, family, subfamily, or any combination of these) of the Transporter Classification Database (TCDB; www.tcdb.org) and examined the following subclasses: α-type channel proteins (TC subclasses 1.A and 1.E), secreted pore-forming toxins (TC subclass 1.C) and secondary carriers (subclass 2.A). Histograms were generated for each of these subclasses, and the results were analyzed according to subclass, family and protein. The results provide an update of topological predictions for integral membrane transport proteins as well as guides for the development of more reliable topological prediction programs, taking family-specific characteristics into account.
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Affiliation(s)
- Abhinay Reddy
- Department of Molecular Biology, University of California at San Diego, La Jolla, Calif., USA
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