1
|
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: 19] [Impact Index Per Article: 9.5] [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.
Collapse
|
2
|
Kalaria RN, Sepulveda-Falla D. Cerebral Small Vessel Disease in Sporadic and Familial Alzheimer Disease. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1888-1905. [PMID: 34331941 PMCID: PMC8573679 DOI: 10.1016/j.ajpath.2021.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 06/15/2021] [Accepted: 07/02/2021] [Indexed: 01/26/2023]
Abstract
Alzheimer disease (AD) is the most common cause of dementia. Biological definitions of AD are limited to the cerebral burden of amyloid β plaques, neurofibrillary pathology, and neurodegeneration. However, current evidence suggests that various features of small vessel disease (SVD) are part of and covertly modify both sporadic and familial AD. Neuroimaging studies suggest that white matter hyperintensities explained by vascular mechanisms occurs frequently in the AD spectrum. Recent advances have further emphasized that frontal periventricular and posterior white matter hyperintensities are associated with cerebral amyloid angiopathy in familial AD. Although whether SVD markers precede the classically recognized biomarkers of disease is debatable, post-mortem studies show that SVD pathology incorporating small cortical and subcortical infarcts, microinfarcts, microbleeds, perivascular spacing, and white matter attenuation is commonly found in sporadic as well as in mutation carriers with confirmed familial AD. Age-related cerebral vessel pathologies such as arteriolosclerosis and cerebral amyloid angiopathy modify progression or worsen risk by shifting the threshold for cognitive impairment and AD dementia. The incorporation of SVD as a biomarker is warranted in the biological definition of AD. Therapeutic interventions directly reducing the burden of brain amyloid β have had no major impact on the disease or delaying cognitive deterioration, but lowering the risk of vascular disease seems the only rational approach to tackle both early- and late-onset AD dementia.
Collapse
Affiliation(s)
- Rajesh N Kalaria
- Neurovascular Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom; Department of Human Anatomy, College of Health Sciences, University of Nairobi, Nairobi, Kenya.
| | - Diego Sepulveda-Falla
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
3
|
Eryilmaz IE, Bakar M, Egeli U, Cecener G, Yurdacan B, Colak DK, Tunca B. Evaluation of the Clinical Features Accompanied by the Gene Mutations: The 2 Novel PSEN1 Variants in a Turkish Early-onset Alzheimer Disease Cohort. Alzheimer Dis Assoc Disord 2021; 35:214-222. [PMID: 33769986 DOI: 10.1097/wad.0000000000000437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 01/03/2021] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Early-onset Alzheimer disease (EOAD) is an earlier Alzheimer disease form which is characterized by the mutations in the amyloid precursor protein, presenilin-1/2 (PSEN1/2), and triggering receptor expressed on myeloid cells 2 (TREM2). However, it is still necessary to report mutational screening in multiethnic groups to improve the genetic background of EOAD due to the variant classification challenge. METHODS We performed targeted sequencing for the amyloid precursor protein, PSEN1, PSEN2, and TREM2 genes in 74 patients and 1 family diagnosed with EOAD. RESULTS Among the detected variants, 8 were coding and 6 were noncoding in 15 of 74 patients. In PSEN1, 2 pathogenic coding variants (T274K and L364P) detected in 2 patients were novel and 3 coding variants (G183V, E318G, and L219P) detected in 2 patients were previously reported. We found 4 patients with the compound heterozygosity for the PSEN2 A23= and N43= and a family with the coexistence of them, and 1 patient with TREM2 Y38C. The coding variation frequency was 12.1%. In silico analysis indicated pathogenic potentials and clinical interpretations of the detected variants. CONCLUSION Our study reveals the rare gene variants including novel ones from the Turkish EOAD cohort and provides to clinicians the list of detected variants in the screened genes, which may also be useful for accurate genetic counseling.
Collapse
Affiliation(s)
| | - Mustafa Bakar
- Neurology Department, Bursa Uludag University, Faculty of Medicine, Gorukle, Bursa
| | | | | | | | | | | |
Collapse
|
4
|
Kabir MT, Uddin MS, Setu JR, Ashraf GM, Bin-Jumah MN, Abdel-Daim MM. Exploring the Role of PSEN Mutations in the Pathogenesis of Alzheimer's Disease. Neurotox Res 2020; 38:833-849. [PMID: 32556937 DOI: 10.1007/s12640-020-00232-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/24/2020] [Accepted: 05/28/2020] [Indexed: 12/25/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia. Mutations of presenilin (PSEN) genes that encode presenilin proteins have been found as the vital causal factors for early-onset familial AD (FAD). AD pathological features such as memory loss, synaptic dysfunction, and formation of plaques have been successfully mimicked in the transgenic mouse models that coexpress FAD-related presenilin and amyloid precursor protein (APP) variants. γ-Secretase (GS) is an enzyme that plays roles in catalyzing intramembranous APP proteolysis to release pathogenic amyloid beta (Aβ). It has been found that presenilins can play a role as the GS's catalytic subunit. FAD-related mutations in presenilins can modify the site of GS cleavage in a way that can elevate the production of longer and highly fibrillogenic Aβ. Presenilins can interact with β-catenin to generate presenilin complexes. Aforesaid interactions have also been studied to observe the mutational and physiological activities in the catenin signal transduction pathway. Along with APP, GS can catalyze intramembrane proteolysis of various substrates that play a vital role in synaptic function. PSEN mutations can cause FAD with autosomal dominant inheritance and early onset of the disease. In this article, we have reviewed the current progress in the analysis of PSENs and the correlation of PSEN mutations and AD pathogenesis.
Collapse
Affiliation(s)
| | - Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh. .,Pharmakon Neuroscience Research Network, Dhaka, Bangladesh.
| | | | - Ghulam Md Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - May N Bin-Jumah
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, 11474, Saudi Arabia
| | - Mohamed M Abdel-Daim
- Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.,Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt
| |
Collapse
|
5
|
Nikolac Perkovic M, Pivac N. Genetic Markers of Alzheimer's Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1192:27-52. [PMID: 31705489 DOI: 10.1007/978-981-32-9721-0_3] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease is a complex and heterogeneous, severe neurodegenerative disorder and the predominant form of dementia, characterized by cognitive disturbances, behavioral and psychotic symptoms, progressive cognitive decline, disorientation, behavioral changes, and death. Genetic background of Alzheimer's disease differs between early-onset familial Alzheimer's disease, other cases of early-onset Alzheimer's disease, and late-onset Alzheimer's disease. Rare cases of early-onset familial Alzheimer's diseases are caused by high-penetrant mutations in genes coding for amyloid precursor protein, presenilin 1, and presenilin 2. Late-onset Alzheimer's disease is multifactorial and associated with many different genetic risk loci (>20), with the apolipoprotein E ε4 allele being a major genetic risk factor for late-onset Alzheimer's disease. Genetic and genomic studies offer insight into many additional genetic risk loci involved in the genetically complex nature of late-onset Alzheimer's disease. This review highlights the contributions of individual loci to the pathogenesis of Alzheimer's disease and suggests that their exact contribution is still not clear. Therefore, the use of genetic markers of Alzheimer's disease, for monitoring development, time course, treatment response, and prognosis of Alzheimer's disease, is still far away from the clinical application, because the contribution of genetic variations to the relative risk of developing Alzheimer's disease is limited. In the light of prediction and prevention of Alzheimer's disease, a novel approach could be found in the form of additive genetic risk scores, which combine additive effects of numerous susceptibility loci.
Collapse
Affiliation(s)
- Matea Nikolac Perkovic
- Division of Molecular Medicine, Rudjer Boskovic Institute, Bijenicka 54, Zagreb, 10000, Croatia
| | - Nela Pivac
- Division of Molecular Medicine, Rudjer Boskovic Institute, Bijenicka 54, Zagreb, 10000, Croatia.
| |
Collapse
|
6
|
Zhang S, Lei C, Liu P, Zhang M, Tao W, Liu H, Liu M. Association between variant amyloid deposits and motor deficits in FAD-associated presenilin-1 mutations: A systematic review. Neurosci Biobehav Rev 2015; 56:180-92. [DOI: 10.1016/j.neubiorev.2015.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 06/20/2015] [Accepted: 07/06/2015] [Indexed: 01/16/2023]
|
7
|
Abstract
Alzheimer’s disease (AD) is a complex and heterogeneous neurodegenerative disorder, classified as either early onset (under 65 years of age), or late onset (over 65 years of age). Three main genes are involved in early onset AD: amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2). The apolipoprotein E (APOE) E4 allele has been found to be a main risk factor for late-onset Alzheimer’s disease. Additionally, genome-wide association studies (GWASs) have identified several genes that might be potential risk factors for AD, including clusterin (CLU), complement receptor 1 (CR1), phosphatidylinositol binding clathrin assembly protein (PICALM), and sortilin-related receptor (SORL1). Recent studies have discovered additional novel genes that might be involved in late-onset AD, such as triggering receptor expressed on myeloid cells 2 (TREM2) and cluster of differentiation 33 (CD33). Identification of new AD-related genes is important for better understanding of the pathomechanisms leading to neurodegeneration. Since the differential diagnoses of neurodegenerative disorders are difficult, especially in the early stages, genetic testing is essential for diagnostic processes. Next-generation sequencing studies have been successfully used for detecting mutations, monitoring the epigenetic changes, and analyzing transcriptomes. These studies may be a promising approach toward understanding the complete genetic mechanisms of diverse genetic disorders such as AD.
Collapse
Affiliation(s)
- Eva Bagyinszky
- Department of BioNano Technology Gachon University, Gyeonggi-do, South Korea
| | - Young Chul Youn
- Department of Neurology, Chung-Ang University College of Medicine, Seoul, South Korea
| | - Seong Soo A An
- Department of BioNano Technology Gachon University, Gyeonggi-do, South Korea
| | - SangYun Kim
- Department of Neurology, Seoul National University Budang Hospital, Gyeonggi-do, South Korea
| |
Collapse
|
8
|
Jeppesen B, Costello L, Fung A, Stanley E, McDonald J, Lambert A, Johnson B, Gentile L. Structure nor stability of the transmembrane spanning 6/7 domain of presenilin I correlates with pathogenicity. Biochem Biophys Res Commun 2007; 355:820-4. [PMID: 17320044 PMCID: PMC1855212 DOI: 10.1016/j.bbrc.2007.02.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2007] [Accepted: 02/08/2007] [Indexed: 11/30/2022]
Abstract
Since its cloning in 1995, missense point mutations in presenilin I (PS-I) have been shown to be responsible for greater than 70% of the cases of early onset familial Alzheimer's disease (EOFAD), which can affect individuals as early as age 18. PS-I is known to be a component of gamma-secretase, the enzyme responsible for cleavage of the amyloid precursor protein (APP) into 42 amino acid peptides that aggregate to form the plaques surrounding neurons of Alzheimer's patients. It has recently been hypothesized that wild-type (wt) PS-I contains an autoinhibitory module that prevents gamma-secretase cleavage of the APP, while pathogenic PS-I point mutants lack a structure necessary for this inhibition. In this work, spectroscopic data is presented that does not correlate structure or stability of the proposed PS-I autoinhibitory module with pathogenicity.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Lisa Gentile
- *Corresponding author: Lisa Gentile, Department of Chemistry, University of Richmond, 28 Westhampton Way, Richmond, VA 23173; tel: 804-484-1578; FAX: 804-287-1897;
| |
Collapse
|
9
|
Papassotiropoulos A, Fountoulakis M, Dunckley T, Stephan DA, Reiman EM. Genetics, transcriptomics, and proteomics of Alzheimer's disease. J Clin Psychiatry 2006; 67:652-70. [PMID: 16669732 PMCID: PMC2259384 DOI: 10.4088/jcp.v67n0418] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To provide an updated overview of the methods used in genetic, transcriptomic, and proteomic studies in Alzheimer's disease and to demonstrate the importance of those methods for the improvement of the current diagnostic and therapeutic possibilities. DATA SOURCES MEDLINE-based search of 233 peer-reviewed articles published between 1975 and 2006. DATA SYNTHESIS Alzheimer's disease is a genetically heterogeneous disorder. Rare mutations in the amyloid precursor protein, presenilin 1, and presenilin 2 genes have shown the importance of the amyloid metabolism for its development. In addition, converging evidence from population-based genetic studies, gene expression studies, and protein profile studies in the brain and in the cerebrospinal fluid suggest the existence of several pathogenetic pathways such as amyloid precursor protein processing, beta-amyloid degradation, tau phosphorylation, proteolysis, protein misfolding, neuroinflammation, oxidative stress, and lipid metabolism. CONCLUSIONS The development of high-throughput genotyping methods and of elaborated statistical analyses will contribute to the identification of genetic risk profiles related to the development and course of this devastating disease. The integration of knowledge derived from genetic, transcriptomic, and proteomic studies will greatly advance our understanding of the causes of Alzheimer's disease, improve our capability of establishing an early diagnosis, help define disease subgroups, and ultimately help to pave the road toward improved and tailored treatments.
Collapse
|
10
|
Larner AJ, Doran M. Clinical phenotypic heterogeneity of Alzheimer's disease associated with mutations of the presenilin-1 gene. J Neurol 2005; 253:139-58. [PMID: 16267640 DOI: 10.1007/s00415-005-0019-5] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Revised: 05/31/2005] [Accepted: 06/13/2005] [Indexed: 10/25/2022]
Abstract
It is now 10 years since the first report of mutations in the presenilin genes that were deterministic for familial autosomal dominant Alzheimer's disease. The most common of these mutations occurs in the presenilin-1 gene (PSEN1) located on chromosome 14. In the ensuing decade, more than 100 PSEN1 mutations have been described. The emphasis of these reports has largely been on the novelty of the mutations and their potential pathogenic consequences rather than detailed clinical, neuropsychological, neuroimaging and neuropathological accounts of patients with the mutation. This article reviews the clinical phenotypes of reported PSEN1 mutations, emphasizing their heterogeneity, and suggesting that other factors, both genetic and epigenetic,must contribute to disease phenotype.
Collapse
Affiliation(s)
- A J Larner
- Cognitive Function Clinic, Walton Centre for Neurology and Neurosurgery Fazakerley, Liverpool, UK.
| | | |
Collapse
|
11
|
Culvenor JG, Ilaya NT, Ryan MT, Canterford L, Hoke DE, Williamson NA, McLean CA, Masters CL, Evin G. Characterization of presenilin complexes from mouse and human brain using Blue Native gel electrophoresis reveals high expression in embryonic brain and minimal change in complex mobility with pathogenic presenilin mutations. ACTA ACUST UNITED AC 2004; 271:375-85. [PMID: 14717705 DOI: 10.1046/j.1432-1033.2003.03936.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The presenilin proteins are required for intramembrane cleavage of a subset of type 1 membrane proteins including the Alzheimer's disease amyloid precursor protein. Previous studies indicate presenilin proteins form enzymatically active high molecular mass complexes consisting of heterodimers of N- and C-terminal fragments in association with nicastrin, presenilin enhancer-2 and anterior pharynx defective-1 proteins. Using Blue Native gel electrophoresis (BN/PAGE) we have studied endogenous presenilin 1 complex mass, stability and association with nicastrin, presenilin enhancer-2 and anterior pharynx defective-1. Solubilization of mouse or human brain membranes with dodecyl-d-maltoside produced a 360-kDa species reactive with antibodies to presenilin 1. Presenilin 1 complex levels were high in embryonic brain. Complex integrity was sensitive to Triton X-100 and SDS, but stable to reducing agent. Addition of 5 M urea caused complex dissolution and nicastrin to migrate as a subcomplex. Nicastrin and presenilin enhancer-2 were detected in the presenilin 1 complex following BN/PAGE, electroelution and second-dimension analysis. Anterior pharynx defective-1 was detected as an 18-kDa form and 9-kDa C-terminal fragment by standard SDS/PAGE of mouse tissues, and as a predominant 36-kDa band after presenilin 1 complex second-dimension analysis. Membranes from brain cortex of Alzheimer's disease patients, or from cases with presenilin 1 missense mutations, indicated no change in presenilin 1 complex mobility. Higher molecular mass presenilin 1-reactive species were detected in brain containing presenilin 1 exon 9 deletion mutation. This abnormality was confirmed using cells transfected with the same presenilin deletion mutation.
Collapse
|
12
|
Kwok JBJ, Halliday GM, Brooks WS, Dolios G, Laudon H, Murayama O, Hallupp M, Badenhop RF, Vickers J, Wang R, Naslund J, Takashima A, Gandy SE, Schofield PR. Presenilin-1 mutation L271V results in altered exon 8 splicing and Alzheimer's disease with non-cored plaques and no neuritic dystrophy. J Biol Chem 2003; 278:6748-54. [PMID: 12493737 DOI: 10.1074/jbc.m211827200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mutation L271V in exon 8 of the presenilin-1 (PS-1) gene was detected in an Alzheimer's disease pedigree. Neuropathological examination of affected individuals identified variant, large, non-cored plaques without neuritic dystrophy, reminiscent of cotton wool plaques. Biochemical analysis of L271V mutation showed that it increased secretion of the 42-amino acid amyloid-beta peptide, suggesting a pathogenic mutation. Analysis of PS-1 transcripts from the brains of two mutation carriers revealed a 17-50% increase in PS-1 transcripts with deletion of exon 8 (PS-1deltaexon8) compared with unrelated Alzheimer's disease brains. Exon trapping analysis confirmed that L271V mutation enhanced the deletion of exon 8. Western blots of brain lysates indicated that PS-1deltaexon8 was overexpressed in an affected individual. Biochemical analysis of PS-1deltaexon8 in COS and BD8 cells indicate the splice isoform is not intrinsically active but interacts with wild-type PS-1 to generate amyloid-beta. Western blots of cell lysates immunoprecipitated with anti-Tau or anti-GSK-3beta antibodies indicated that PS-1deltaexon8, unlike wild-type PS-1, does not interact directly with Tau or GSK-3beta, potential modifiers of neuritic dystrophy. We postulate that variant plaques observed in this family are due in part to the effects of PS-1deltaexon8 and that interaction between PS-1 and various protein complexes are necessary for neuritic plaque formation.
Collapse
Affiliation(s)
- John B J Kwok
- Garvan Institute of Medical Research, Darlinghurst, Sydney 2010, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Tammer AH, Coia G, Cappai R, Fuller S, Masters CL, Hudson P, Underwood JR. Generation of a recombinant Fab antibody reactive with the Alzheimer's disease-related Abeta peptide. Clin Exp Immunol 2002; 129:453-63. [PMID: 12197886 PMCID: PMC1906481 DOI: 10.1046/j.1365-2249.2002.01905.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2002] [Indexed: 12/31/2022] Open
Abstract
A recombinant Fab antibody, designated 1E8-4b, which reacts with the Alzheimer's disease (AD)-related Abeta peptides, Abeta[1-40], Abeta[1-42] and Abeta[1-43] has been developed. The 1E8-4b Fab was constructed by cloning the V(H)C(H1) and V(L)C(L) domains from the parent hybridoma 1E8 antibody, reported previously to recognize these Abeta peptides. Briefly, a C-terminal Flag tag sequence was incorporated into this construct, which was ligated into the vector pHFA2 and expressed in Escherichia coli. Following purification on an M2 anti-Flag affinity column, the 1E8-4b recombinant Fab antibody was shown to bind plaques within sections of brain tissue from CERAD-defined AD patients by immunohistochemistry. ELISA, epitope mapping and immunoblotting confirmed the recognition of the Abeta1-40/42/43] peptides by the 1E8-4b Fab. The 1E8-4b Fab did not recognize APP695 or APP770 which contain the Abeta sequence. The Abeta specificity of the recombinant 1E8-4b Fab antibody was identical to the parent 1E8 monoclonal antibody.
Collapse
Affiliation(s)
- A H Tammer
- Department of Pathology, Melbourne University, Parkville, Victoria, Australia
| | | | | | | | | | | | | |
Collapse
|
14
|
Verkkoniemi A, Kalimo H, Paetau A, Somer M, Iwatsubo T, Hardy J, Haltia M. Variant Alzheimer disease with spastic paraparesis: neuropathological phenotype. J Neuropathol Exp Neurol 2001; 60:483-92. [PMID: 11379823 DOI: 10.1093/jnen/60.5.483] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Variant Alzheimer disease (varAD) is clinically characterized by the combination of presenile dementia with spastic paraparesis and is caused by certain mutations of the presenilin 1 (PS-1) gene. We now present the unusual neuropathological phenotype of varAD as seen in 5 affected members of the original Finnish family with a genomic deletion encompassing exon 9 of the PS-1 gene. Their primary and association cortices and hippocampus showed a profusion of eosinophilic, roundish structures with distinct borders termed "cotton wool" plaques (CWPs). The CWPs were immunoreactive for Abeta42/43 but weakly or not at all for Abeta40 isoforms of the amyloid beta peptide (Abeta). They were devoid of a congophilic core, and fibrillar amyloid could not be identified within them by electron microscopy. Confocal microscopy showed reduced density of axons within individual CWPs and only few CWP-related PHF-tau-positive dystrophic neurites. CWPs were particularly numerous in the medial motor cortex representing the lower extremities, and degeneration of the lateral corticospinal tracts was observed at the level of the medulla oblongata and the spinal cord. In addition to the predominant CWPs, variable numbers of diffuse and cored plaques were found in the cerebral cortex. Diffuse and non-neuritic cored amyloid plaques but no CWPs occurred in the cerebellum. In conclusion, varAD in this Finnish family is distinct from classic AD because of the degeneration of lateral corticospinal tracts, predominance of CWPs devoid of fibrillar amyloid cores in the cerebral cortex, and presence of non-neuritic amyloid plaques in the cerebellum.
Collapse
Affiliation(s)
- A Verkkoniemi
- Department of Pathology, University of Helsinki and Helsinki University Central Hospital, Finland
| | | | | | | | | | | | | |
Collapse
|
15
|
Yakubovskaya MG, Neschastnova AA, Humphrey KE, Babon JJ, Popenko VI, Smith MJ, Lambrinakos A, Lipatova ZV, Dobrovolskaia MA, Cappai R, Masters CL, Belitsky GA, Cotton RG. Interaction of linear homologous DNA duplexes via Holliday junction formation. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:7-14. [PMID: 11121096 DOI: 10.1046/j.1432-1327.2001.01861.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Interaction of linear homologous DNA duplexes by formation of Holliday junctions was revealed by electrophoresis and confirmed by electron microscopy. The phenomenon was demonstrated using a model of five purified PCR products of different size and sequence. The double-stranded structure of interacting DNA fragments was confirmed using several consecutive purifications, S1-nuclease analysis, and electron microscopy. Formation of Holliday junctions depends on DNA concentration. A thermodynamic equilibrium between duplexes and Holliday junctions was shown. We propose that homologous duplex interaction is initiated by nucleation of several dissociated terminal base pairs of two fragments. This process is followed by branch migration creating a population of Holliday junctions with the branch point at different sites. Finally, Holliday junctions are resolved via branch migration to new or previously existing duplexes. The phenomenon is a new property of DNA. This type of DNA-DNA interaction may contribute to the process of Holliday junction formation in vivo controlled by DNA conformation and DNA-protein interactions. It is of practical significance for optimization of different PCR-based methods of gene analysis, especially those involving heteroduplex formation.
Collapse
Affiliation(s)
- M G Yakubovskaya
- Carcinogenesis Institute, Cancer Research Centre, Russian Academy of Medical Sciences, Moscow, Russia.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Fraser PE, Yang DS, Yu G, Lévesque L, Nishimura M, Arawaka S, Serpell LC, Rogaeva E, St George-Hyslop P. Presenilin structure, function and role in Alzheimer disease. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1502:1-15. [PMID: 10899427 DOI: 10.1016/s0925-4439(00)00028-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Numerous missense mutations in the presenilins are associated with the autosomal dominant form of familial Alzheimer disease. Presenilin genes encode polytopic transmembrane proteins, which are processed by proteolytic cleavage and form high-molecular-weight complexes under physiological conditions. The presenilins have been suggested to be functionally involved in developmental morphogenesis, unfolded protein responses and processing of selected proteins including the beta-amyloid precursor protein. Although the underlying mechanism by which presenilin mutations lead to development of Alzheimer disease remains elusive, one consistent mutational effect is an overproduction of long-tailed amyloid beta-peptides. Furthermore, presenilins interact with beta-catenin to form presenilin complexes, and the physiological and mutational effects are also observed in the catenin signal transduction pathway.
Collapse
Affiliation(s)
- P E Fraser
- Centre for Research in Neurodegenerative Diseases, University of Toronto, Ont, Canada.
| | | | | | | | | | | | | | | | | |
Collapse
|