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Kantor B, O'Donovan B, Rittiner J, Hodgson D, Lindner N, Guerrero S, Dong W, Zhang A, Chiba-Falek O. The therapeutic implications of all-in-one AAV-delivered epigenome-editing platform in neurodegenerative disorders. Nat Commun 2024; 15:7259. [PMID: 39179542 PMCID: PMC11344155 DOI: 10.1038/s41467-024-50515-6] [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: 04/09/2023] [Accepted: 07/12/2024] [Indexed: 08/26/2024] Open
Abstract
Safely and efficiently controlling gene expression is a long-standing goal of biomedical research, and CRISPR/Cas system can be harnessed to create powerful tools for epigenetic editing. Adeno-associated-viruses (AAVs) represent the delivery vehicle of choice for therapeutic platform. However, their small packaging capacity isn't suitable for large constructs including most CRISPR/dCas9-effector vectors. Thus, AAV-based CRISPR/Cas systems have been delivered via two separate viral vectors. Here we develop a compact CRISPR/dCas9-based repressor system packaged in AAV as a single optimized vector. The system comprises the small Staphylococcus aureus (Sa)dCas9 and an engineered repressor molecule, a fusion of MeCP2's transcription repression domain (TRD) and KRAB. The dSaCas9-KRAB-MeCP2(TRD) vector platform repressed robustly and sustainably the expression of multiple genes-of-interest, in vitro and in vivo, including ApoE, the strongest genetic risk factor for late onset Alzheimer's disease (LOAD). Our platform broadens the CRISPR/dCas9 toolset available for transcriptional manipulation of gene expression in research and therapeutic settings.
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Affiliation(s)
- Boris Kantor
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA.
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA.
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA.
| | - Bernadette O'Donovan
- Division of Translational Brain Sciences, Department of Neurology, Duke University School of Medicine, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC, USA
| | - Joseph Rittiner
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Dellila Hodgson
- Division of Translational Brain Sciences, Department of Neurology, Duke University School of Medicine, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC, USA
| | - Nicholas Lindner
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Sophia Guerrero
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Wendy Dong
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Austin Zhang
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University School of Medicine, Durham, NC, USA.
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC, USA.
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Kantor B, Odonovan B, Rittiner J, Hodgson D, Lindner N, Guerrero S, Dong W, Zhang A, Chiba-Falek O. All-in-one AAV-delivered epigenome-editing platform: proof-of-concept and therapeutic implications for neurodegenerative disorders. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.14.536951. [PMID: 38798630 PMCID: PMC11118458 DOI: 10.1101/2023.04.14.536951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Safely and efficiently controlling gene expression is a long-standing goal of biomedical research, and the recently discovered bacterial CRISPR/Cas system can be harnessed to create powerful tools for epigenetic editing. Current state-of-the-art systems consist of a deactivated-Cas9 nuclease (dCas9) fused to one of several epigenetic effector motifs/domains, along with a guide RNA (gRNA) which defines the genomic target. Such systems have been used to safely and effectively silence or activate a specific gene target under a variety of circumstances. Adeno-associated vectors (AAVs) are the therapeutic platform of choice for the delivery of genetic cargo; however, their small packaging capacity is not suitable for delivery of large constructs, which includes most CRISPR/dCas9-effector systems. To circumvent this, many AAV-based CRISPR/Cas tools are delivered in two pieces, from two separate viral cassettes. However, this approach requires higher viral payloads and usually is less efficient. Here we develop a compact dCas9-based repressor system packaged within a single, optimized AAV vector. The system uses a smaller dCas9 variant derived from Staphylococcus aureus ( Sa ). A novel repressor was engineered by fusing the small transcription repression domain (TRD) from MeCP2 with the KRAB repression domain. The final d Sa Cas9-KRAB-MeCP2(TRD) construct can be efficiently packaged, along with its associated gRNA, into AAV particles. Using reporter assays, we demonstrate that the platform is capable of robustly and sustainably repressing the expression of multiple genes-of-interest, both in vitro and in vivo . Moreover, we successfully reduced the expression of ApoE, the stronger genetic risk factor for late onset Alzheimer's disease (LOAD). This new platform will broaden the CRISPR/dCas9 toolset available for transcriptional manipulation of gene expression in research and therapeutic settings.
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Ramos AA, Galiano-Castillo N, Machado L. Cognitive Functioning of Unaffected First-degree Relatives of Individuals With Late-onset Alzheimer's Disease: A Systematic Literature Review and Meta-analysis. Neuropsychol Rev 2023; 33:659-674. [PMID: 36057684 PMCID: PMC10770217 DOI: 10.1007/s11065-022-09555-2] [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: 12/05/2021] [Accepted: 06/10/2022] [Indexed: 10/14/2022]
Abstract
First-degree relatives of individuals with late-onset Alzheimer's disease (LOAD) are at increased risk for developing dementia, yet the associations between family history of LOAD and cognitive dysfunction remain unclear. In this quantitative review, we provide the first meta-analysis on the cognitive profile of unaffected first-degree blood relatives of LOAD-affected individuals compared to controls without a family history of LOAD. A systematic literature search was conducted in PsycINFO, PubMed /MEDLINE, and Scopus. We fitted a three-level structural equation modeling meta-analysis to control for non-independent effect sizes. Heterogeneity and risk of publication bias were also investigated. Thirty-four studies enabled us to estimate 218 effect sizes across several cognitive domains. Overall, first-degree relatives (n = 4,086, mean age = 57.40, SD = 4.71) showed significantly inferior cognitive performance (Hedges' g = -0.16; 95% CI, -0.25 to -0.08; p < .001) compared to controls (n = 2,388, mean age = 58.43, SD = 5.69). Specifically, controls outperformed first-degree relatives in language, visuospatial and verbal long-term memory, executive functions, verbal short-term memory, and verbal IQ. Among the first-degree relatives, APOE ɛ4 carriership was associated with more significant dysfunction in cognition (g = -0.24; 95% CI, -0.38 to -0.11; p < .001) compared to non-carriers (g = -0.14; 95% CI, -0.28 to -0.01; p = .04). Cognitive test type was significantly associated with between-group differences, accounting for 65% (R23 = .6499) of the effect size heterogeneity in the fitted regression model. No evidence of publication bias was found. The current findings provide support for mild but robust cognitive dysfunction in first-degree relatives of LOAD-affected individuals that appears to be moderated by cognitive domain, cognitive test type, and APOE ɛ4.
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Affiliation(s)
- Ari Alex Ramos
- Department of Psychology and Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
- Brain Research New Zealand, Auckland, New Zealand.
- Department of Psychology, Pontifical Catholic University of Paraná, Rua Imaculada Conceição, 1155, Curitiba, CEP 80.215-901, Brazil.
| | - Noelia Galiano-Castillo
- Department of Physical Therapy, Health Sciences Faculty, "Cuidate" from Biomedical Group (BIO277), Instituto de Investigación Biosanitaria (ibs.GRANADA), and Sport and Health Research Center (IMUDs), Granada, Spain, University of Granada, Granada, Spain
| | - Liana Machado
- Department of Psychology and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Auckland, New Zealand
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Gamache J, Gingerich D, Shwab EK, Barrera J, Garrett ME, Hume C, Crawford GE, Ashley-Koch AE, Chiba-Falek O. Integrative single-nucleus multi-omics analysis prioritizes candidate cis and trans regulatory networks and their target genes in Alzheimer's disease brains. Cell Biosci 2023; 13:185. [PMID: 37789374 PMCID: PMC10546724 DOI: 10.1186/s13578-023-01120-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/30/2023] [Indexed: 10/05/2023] Open
Abstract
BACKGROUND The genetic underpinnings of late-onset Alzheimer's disease (LOAD) are yet to be fully elucidated. Although numerous LOAD-associated loci have been discovered, the causal variants and their target genes remain largely unknown. Since the brain is composed of heterogenous cell subtypes, it is imperative to study the brain on a cell subtype specific level to explore the biological processes underlying LOAD. METHODS Here, we present the largest parallel single-nucleus (sn) multi-omics study to simultaneously profile gene expression (snRNA-seq) and chromatin accessibility (snATAC-seq) to date, using nuclei from 12 normal and 12 LOAD brains. We identified cell subtype clusters based on gene expression and chromatin accessibility profiles and characterized cell subtype-specific LOAD-associated differentially expressed genes (DEGs), differentially accessible peaks (DAPs) and cis co-accessibility networks (CCANs). RESULTS Integrative analysis defined disease-relevant CCANs in multiple cell subtypes and discovered LOAD-associated cell subtype-specific candidate cis regulatory elements (cCREs), their candidate target genes, and trans-interacting transcription factors (TFs), some of which, including ELK1, JUN, and SMAD4 in excitatory neurons, were also LOAD-DEGs. Finally, we focused on a subset of cell subtype-specific CCANs that overlap known LOAD-GWAS regions and catalogued putative functional SNPs changing the affinities of TF motifs within LOAD-cCREs linked to LOAD-DEGs, including APOE and MYO1E in a specific subtype of microglia and BIN1 in a subpopulation of oligodendrocytes. CONCLUSIONS To our knowledge, this study represents the most comprehensive systematic interrogation to date of regulatory networks and the impact of genetic variants on gene dysregulation in LOAD at a cell subtype resolution. Our findings reveal crosstalk between epigenetic, genomic, and transcriptomic determinants of LOAD pathogenesis and define catalogues of candidate genes, cCREs, and variants involved in LOAD genetic etiology and the cell subtypes in which they act to exert their pathogenic effects. Overall, these results suggest that cell subtype-specific cis-trans interactions between regulatory elements and TFs, and the genes dysregulated by these networks contribute to the development of LOAD.
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Affiliation(s)
- Julia Gamache
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, DUMC Box 2900, Durham, NC, 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, 27708, USA
| | - Daniel Gingerich
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, DUMC Box 2900, Durham, NC, 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, 27708, USA
| | - E Keats Shwab
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, DUMC Box 2900, Durham, NC, 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, 27708, USA
| | - Julio Barrera
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, DUMC Box 2900, Durham, NC, 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, 27708, USA
| | - Melanie E Garrett
- Duke Molecular Physiology Institute, Duke University Medical Center, DUMC Box 104775, Durham, NC, 27701, USA
| | - Cordelia Hume
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, DUMC Box 2900, Durham, NC, 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, 27708, USA
| | - Gregory E Crawford
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, 27708, USA.
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, DUMC Box 3382, Durham, NC, 27708, USA.
- Center for Advanced Genomic Technologies, Duke University Medical Center, Durham, NC, 27708, USA.
| | - Allison E Ashley-Koch
- Duke Molecular Physiology Institute, Duke University Medical Center, DUMC Box 104775, Durham, NC, 27701, USA.
- Department of Medicine, Duke University Medical Center, Durham, NC, 27708, USA.
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, DUMC Box 2900, Durham, NC, 27710, USA.
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, 27708, USA.
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Yu Z, Shi Z, Dan T, Dere M, Kim M, Li Q, Wu G. Uncovering Diverse Mechanistic Spreading Pathways in Disease Progression of Alzheimer's Disease. J Alzheimers Dis Rep 2023; 7:855-872. [PMID: 37662609 PMCID: PMC10473126 DOI: 10.3233/adr-230081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 09/05/2023] Open
Abstract
Background The AT[N] research framework focuses on three major biomarkers in Alzheimer's disease (AD): amyloid-β deposition (A), pathologic tau (T), and neurodegeneration [N]. Objective We hypothesize that the diverse mechanisms such as A⟶T and A⟶[N] pathways from one brain region to others, may underlie the wide variation in clinical symptoms. We aim to uncover the causal-like effect of regional AT[N] biomarkers on cognitive decline as well as the interaction with non-modifiable risk factors such as age and APOE4. Methods We apply multi-variate statistical inference to uncover all possible mechanistic spreading pathways through which the aggregation of an upstream biomarker (e.g., increased amyloid level) in a particular brain region indirectly impacts cognitive decline, via the cascade build-up of a downstream biomarker (e.g., reduced metabolism level) in another brain region. Furthermore, we investigate the survival time for each identified region-to-region pathological pathway toward the AD onset. Results We have identified a collection of critical brain regions on which the amyloid burdens exert an indirect effect on the decline in memory and executive function (EF) domain, being mediated by the reduction of metabolism level at other brain regions. APOE4 status has been found not only involved in many A⟶N mechanistic pathways but also significantly contributes to the risk of developing AD. Conclusion Our major findings include 1) the region-to-region A⟶N⟶MEM and A⟶N⟶MEM pathways exhibit distinct spatial patterns; 2) APOE4 is significantly associated with both direct and indirect effects on the cognitive decline while sex difference has not been identified in the mediation analysis.
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Affiliation(s)
- Zhentao Yu
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - Zhuoyu Shi
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - Tingting Dan
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - Mustafa Dere
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - Minjeong Kim
- Department of Computer Science, University of North Carolina, Greensboro, NC, USA
| | - Quefeng Li
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - Guorong Wu
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Computer Science, University of North Carolina, Chapel Hill, NC, USA
- Department of Statistics and Operations Research, University of North Carolina, Chapel Hill, NC, USA
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, NC, USA
- Carolina Institute of Developmental Disabilities, University of North Carolina, Chapel Hill, NC, USA
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Gottschalk WK, Mahon S, Hodgson D, Barrera J, Hill D, Wei A, Kumar M, Dai K, Anderson L, Mihovilovic M, Lutz MW, Chiba-Falek O. The APOE-TOMM40 Humanized Mouse Model: Characterization of Age, Sex, and PolyT Variant Effects on Gene Expression. J Alzheimers Dis 2023; 94:1563-1576. [PMID: 37458041 PMCID: PMC10733864 DOI: 10.3233/jad-230451] [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] [Indexed: 07/18/2023]
Abstract
BACKGROUND The human chromosome 19q13.32 is a gene rich region and has been associated with multiple phenotypes, including late onset Alzheimer's disease (LOAD) and other age-related conditions. OBJECTIVE Here we developed the first humanized mouse model that contains the entire TOMM40 and APOE genes with all intronic and intergenic sequences including the upstream and downstream regions. Thus, the mouse model carries the human TOMM40 and APOE genes and their intact regulatory sequences. METHODS We generated the APOE-TOMM40 humanized mouse model in which the entire mouse region was replaced with the human (h)APOE-TOMM40 loci including their upstream and downstream flanking regulatory sequences using recombineering technologies. We then measured the expression of the human TOMM40 and APOE genes in the mice brain, liver, and spleen tissues using TaqMan based mRNA expression assays. RESULTS We investigated the effects of the '523' polyT genotype (S/S or VL/VL), sex, and age on the human TOMM40- and APOE-mRNAs expression levels using our new humanized mouse model. The analysis revealed tissue specific and shared effects of the '523' polyT genotype, sex, and age on the regulation of the human TOMM40 and APOE genes. Noteworthy, the regulatory effect of the '523' polyT genotype was observed for all studied organs. CONCLUSION The model offers new opportunities for basic science, translational, and preclinical drug discovery studies focused on the APOE genomic region in relation to LOAD and other conditions in adulthood.
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Affiliation(s)
- William K. Gottschalk
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Scott Mahon
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Dellila Hodgson
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Julio Barrera
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Delaney Hill
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Angela Wei
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Manish Kumar
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Kathy Dai
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Lauren Anderson
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Mirta Mihovilovic
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Michael W. Lutz
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
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Neuronal ApoE Regulates the Cell-to-Cell Transmission of α-Synuclein. Int J Mol Sci 2022; 23:ijms23158311. [PMID: 35955451 PMCID: PMC9369063 DOI: 10.3390/ijms23158311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 11/17/2022] Open
Abstract
The presence of protein inclusions, called Lewy bodies (LBs) and Lewy neurites (LNs), in the brain is the main feature of Parkinson’s disease (PD). Recent evidence that the prion-like propagation of α-synuclein (α-syn), as a major component of LBs and LNs, plays an important role in the progression of PD has gained much attention, although the molecular mechanism remains unclear. In this study, we evaluated whether neuronal ApoE regulates the cell-to-cell transmission of α-syn and explored its molecular mechanism using in vitro and in vivo model systems. We demonstrate that neuronal ApoE deficiency attenuates both α-syn uptake and release by downregulating LRP-1 and LDLR expression and enhancing chaperone-mediated autophagy activity, respectively, thereby contributing to α-syn propagation. In addition, we observed that α-syn propagation was attenuated in ApoE knockout mice injected with pre-formed mouse α-syn fibrils. This study will help our understanding of the molecular mechanisms underlying α-syn propagation.
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He L, Loika Y, Kulminski AM. Allele-specific analysis reveals exon- and cell-type-specific regulatory effects of Alzheimer's disease-associated genetic variants. Transl Psychiatry 2022; 12:163. [PMID: 35436980 PMCID: PMC9016079 DOI: 10.1038/s41398-022-01913-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 03/18/2022] [Accepted: 03/22/2022] [Indexed: 01/20/2023] Open
Abstract
Elucidating regulatory effects of Alzheimer's disease (AD)-associated genetic variants is critical for unraveling their causal pathways and understanding the pathology. However, their cell-type-specific regulatory mechanisms in the brain remain largely unclear. Here, we conducted an analysis of allele-specific expression quantitative trait loci (aseQTLs) for 33 AD-associated variants in four brain regions and seven cell types using ~3000 bulk RNA-seq samples and >0.25 million single nuclei. We first develop a flexible hierarchical Poisson mixed model (HPMM) and demonstrate its superior statistical power to a beta-binomial model achieved by unifying samples in both allelic and genotype-level expression data. Using the HPMM, we identified 24 (~73%) aseQTLs in at least one brain region, including three new eQTLs associated with CA12, CHRNE, and CASS4. Notably, the APOE ε4 variant reduces APOE expression across all regions, even in AD-unaffected controls. Our results reveal region-dependent and exon-specific effects of multiple aseQTLs, such as rs2093760 with CR1, rs7982 with CLU, and rs3865444 with CD33. In an attempt to pinpoint the cell types responsible for the observed tissue-level aseQTLs using the snRNA-seq data, we detected many aseQTLs in microglia or monocytes associated with immune-related genes, including HLA-DQB1, HLA-DQA2, CD33, FCER1G, MS4A6A, SPI1, and BIN1, highlighting the regulatory role of AD-associated variants in the immune response. These findings provide further insights into potential causal pathways and cell types mediating the effects of the AD-associated variants.
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Affiliation(s)
- Liang He
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA.
| | - Yury Loika
- grid.26009.3d0000 0004 1936 7961Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC USA
| | - Alexander M. Kulminski
- grid.26009.3d0000 0004 1936 7961Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC USA
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Qiu S, Palavicini JP, Wang J, Gonzalez NS, He S, Dustin E, Zou C, Ding L, Bhattacharjee A, Van Skike CE, Galvan V, Dupree JL, Han X. Adult-onset CNS myelin sulfatide deficiency is sufficient to cause Alzheimer's disease-like neuroinflammation and cognitive impairment. Mol Neurodegener 2021; 16:64. [PMID: 34526055 PMCID: PMC8442347 DOI: 10.1186/s13024-021-00488-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/26/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Human genetic association studies point to immune response and lipid metabolism, in addition to amyloid-beta (Aβ) and tau, as major pathways in Alzheimer's disease (AD) etiology. Accumulating evidence suggests that chronic neuroinflammation, mainly mediated by microglia and astrocytes, plays a causative role in neurodegeneration in AD. Our group and others have reported early and dramatic losses of brain sulfatide in AD cases and animal models that are mediated by ApoE in an isoform-dependent manner and accelerated by Aβ accumulation. To date, it remains unclear if changes in specific brain lipids are sufficient to drive AD-related pathology. METHODS To study the consequences of CNS sulfatide deficiency and gain insights into the underlying mechanisms, we developed a novel mouse model of adult-onset myelin sulfatide deficiency, i.e., tamoxifen-inducible myelinating glia-specific cerebroside sulfotransferase (CST) conditional knockout mice (CSTfl/fl/Plp1-CreERT), took advantage of constitutive CST knockout mice (CST-/-), and generated CST/ApoE double knockout mice (CST-/-/ApoE-/-), and assessed these mice using a broad range of methodologies including lipidomics, RNA profiling, behavioral testing, PLX3397-mediated microglia depletion, mass spectrometry (MS) imaging, immunofluorescence, electron microscopy, and Western blot. RESULTS We found that mild central nervous system (CNS) sulfatide losses within myelinating cells are sufficient to activate disease-associated microglia and astrocytes, and to increase the expression of AD risk genes (e.g., Apoe, Trem2, Cd33, and Mmp12), as well as previously established causal regulators of the immune/microglia network in late-onset AD (e.g., Tyrobp, Dock, and Fcerg1), leading to chronic AD-like neuroinflammation and mild cognitive impairment. Notably, neuroinflammation and mild cognitive impairment showed gender differences, being more pronounced in females than males. Subsequent mechanistic studies demonstrated that although CNS sulfatide losses led to ApoE upregulation, genetically-induced myelin sulfatide deficiency led to neuroinflammation independently of ApoE. These results, together with our previous studies (sulfatide deficiency in the context of AD is mediated by ApoE and accelerated by Aβ accumulation) placed both Aβ and ApoE upstream of sulfatide deficiency-induced neuroinflammation, and suggested a positive feedback loop where sulfatide losses may be amplified by increased ApoE expression. We also demonstrated that CNS sulfatide deficiency-induced astrogliosis and ApoE upregulation are not secondary to microgliosis, and that astrogliosis and microgliosis seem to be driven by activation of STAT3 and PU.1/Spi1 transcription factors, respectively. CONCLUSION Our results strongly suggest that sulfatide deficiency is an important contributor and driver of neuroinflammation and mild cognitive impairment in AD pathology.
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Affiliation(s)
- Shulan Qiu
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Juan Pablo Palavicini
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Jianing Wang
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Present Address: State Key Lab. of Environmental & Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hongkong, China
| | - Nancy S Gonzalez
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Sijia He
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Elizabeth Dustin
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia, 23284, USA
| | - Cheng Zou
- BRC Bioinformatics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, 14853, USA
| | - Lin Ding
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, China
| | - Anindita Bhattacharjee
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Candice E Van Skike
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Veronica Galvan
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Jeffrey L Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia, 23284, USA
- Research Division, McGuire Veterans Affairs Medical Center, Richmond, Virginia, 23249, USA
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA.
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
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10
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Kiris I, Basar MK, Sahin B, Gurel B, Coskun J, Mroczek T, Baykal AT. Evaluation of the Therapeutic Effect of Lycoramine on Alzheimer's Disease in Mouse Model. Curr Med Chem 2021; 28:3449-3473. [PMID: 33200692 DOI: 10.2174/0929867327999201116193126] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Alzheimer's disease is one of the leading health problems characterized by the accumulation of Aβ and hyperphosphorylated tau that account for the senile plaque formations causing extensive cognitive decline. Many of the clinical diagnoses of Alzheimer's disease are made in the late stages, when the pathological changes have already progressed. OBJECTIVE The objective of this study is to evaluate the promising therapeutic effects of a natural compound, lycoramine, which has been shown to have therapeutic potential in several studies and to understand its mechanism of action on the molecular level via differential protein expression analyses. METHODS Lycoramine and galantamine, an FDA approved drug used in the treatment of mild to moderate AD, were administered to 12 month-old 5xFAD mice. Effects of the compounds were investigated by Morris water maze, immunohistochemistry and label- free differential protein expression analyses. RESULTS Here we demonstrated the reversal of cognitive decline via behavioral testing and the clearance of Aβ plaques. Proteomics analysis provided in-depth information on the statistically significant protein perturbations in the cortex, hippocampus and cerebellum sections to hypothesize the possible clearance mechanisms of the plaque formation and the molecular mechanism of the reversal of cognitive decline in a transgenic mouse model. Bioinformatics analyses showed altered molecular pathways that can be linked with the reversal of cognitive decline observed after lycoramine administration but not with galantamine. CONCLUSION Lycoramine shows therapeutic potential to halt and reverse cognitive decline at the late stages of disease progression, and holds great promise for the treatment of Alzheimer's disease.
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Affiliation(s)
- Irem Kiris
- Department of Medical Biochemistry, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Merve Karayel Basar
- Department of Medical Biochemistry, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Betul Sahin
- Acibadem Labmed Clinical Laboratories, R&D Center, Istanbul, Turkey
| | - Busra Gurel
- Department of Medical Biochemistry, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Julide Coskun
- Acibadem Labmed Clinical Laboratories, R&D Center, Istanbul, Turkey
| | - Tomasz Mroczek
- Department of Pharmacognosy, Medical University of Lublin, Lublin, Poland
| | - Ahmet Tarik Baykal
- Department of Medical Biochemistry, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
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11
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MacDougall G, Brown LY, Kantor B, Chiba-Falek O. The Path to Progress Preclinical Studies of Age-Related Neurodegenerative Diseases: A Perspective on Rodent and hiPSC-Derived Models. Mol Ther 2021; 29:949-972. [PMID: 33429080 PMCID: PMC7934639 DOI: 10.1016/j.ymthe.2021.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/03/2020] [Accepted: 01/01/2021] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most prevalent age-related neurodegenerative diseases, and currently no effective clinical treatments exist for either, despite decades of clinical trials. The failure to translate preclinical findings into effective treatments is indicative of a problem in the current evaluation pipeline for potential therapeutics. At present, there are no useful animal models for AD and PD research that reflect the entire biology of the diseases, specifically, the more common non-Mendelian forms. Whereas the field continues to seek suitable rodent models for investigating potential therapeutics for these diseases, rodent models have still been used primarily for preclinical studies. Here, we advocate for a paradigm shift toward the application of human-induced pluripotent stem cell (hiPSC)-derived systems for PD and AD modeling and the development of improved human-based models in a dish for drug discovery and preclinical assessment of therapeutic targets.
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Affiliation(s)
- Gabriella MacDougall
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA; Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Logan Y Brown
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Center for Advanced Genomic Technologies, Duke University Medical Center, Durham, NC 27710, USA; Viral Vector Core, Duke University Medical Center, Durham, NC 27710, USA
| | - Boris Kantor
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Center for Advanced Genomic Technologies, Duke University Medical Center, Durham, NC 27710, USA; Viral Vector Core, Duke University Medical Center, Durham, NC 27710, USA.
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA; Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27710, USA.
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12
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Husain MA, Laurent B, Plourde M. APOE and Alzheimer's Disease: From Lipid Transport to Physiopathology and Therapeutics. Front Neurosci 2021; 15:630502. [PMID: 33679311 PMCID: PMC7925634 DOI: 10.3389/fnins.2021.630502] [Citation(s) in RCA: 141] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/20/2021] [Indexed: 12/23/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder characterized by extracellular amyloid β (Aβ) and intraneuronal tau protein aggregations. One risk factor for developing AD is the APOE gene coding for the apolipoprotein E protein (apoE). Humans have three versions of APOE gene: ε2, ε3, and ε4 allele. Carrying the ε4 allele is an AD risk factor while carrying the ε2 allele is protective. ApoE is a component of lipoprotein particles in the plasma at the periphery, as well as in the cerebrospinal fluid (CSF) and in the interstitial fluid (ISF) of brain parenchyma in the central nervous system (CNS). ApoE is a major lipid transporter that plays a pivotal role in the development, maintenance, and repair of the CNS, and that regulates multiple important signaling pathways. This review will focus on the critical role of apoE in AD pathogenesis and some of the currently apoE-based therapeutics developed in the treatment of AD.
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Affiliation(s)
- Mohammed Amir Husain
- Centre de Recherche Sur le Vieillissement, Centre Intégré Universitaire de Santé et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada.,Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Benoit Laurent
- Centre de Recherche Sur le Vieillissement, Centre Intégré Universitaire de Santé et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada.,Département de Biochimie et Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Mélanie Plourde
- Centre de Recherche Sur le Vieillissement, Centre Intégré Universitaire de Santé et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada.,Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
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13
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Yang A, Kantor B, Chiba-Falek O. APOE: The New Frontier in the Development of a Therapeutic Target towards Precision Medicine in Late-Onset Alzheimer's. Int J Mol Sci 2021; 22:1244. [PMID: 33513969 PMCID: PMC7865856 DOI: 10.3390/ijms22031244] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) has a critical unmet medical need. The consensus around the amyloid cascade hypothesis has been guiding pre-clinical and clinical research to focus mainly on targeting beta-amyloid for treating AD. Nevertheless, the vast majority of the clinical trials have repeatedly failed, prompting the urgent need to refocus on other targets and shifting the paradigm of AD drug development towards precision medicine. One such emerging target is apolipoprotein E (APOE), identified nearly 30 years ago as one of the strongest and most reproduceable genetic risk factor for late-onset Alzheimer's disease (LOAD). An exploration of APOE as a new therapeutic culprit has produced some very encouraging results, proving that the protein holds promise in the context of LOAD therapies. Here, we review the strategies to target APOE based on state-of-the-art technologies such as antisense oligonucleotides, monoclonal antibodies, and gene/base editing. We discuss the potential of these initiatives in advancing the development of novel precision medicine therapies to LOAD.
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Affiliation(s)
- Anna Yang
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA;
| | - Boris Kantor
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA;
- Viral Vector Core, Duke University Medical Center, Durham, NC 27710, USA
- Duke Center for Advanced Genomic Technologies, Durham, NC 27708, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA;
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27708, USA
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14
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Bou Sleiman M, Jha P, Houtkooper R, Williams RW, Wang X, Auwerx J. The Gene-Regulatory Footprint of Aging Highlights Conserved Central Regulators. Cell Rep 2020; 32:108203. [PMID: 32997995 PMCID: PMC7527782 DOI: 10.1016/j.celrep.2020.108203] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/31/2020] [Accepted: 09/04/2020] [Indexed: 12/13/2022] Open
Abstract
Many genes and pathways have been linked to aging, yet our understanding of underlying molecular mechanisms is still lacking. Here, we measure changes in the transcriptome, histone modifications, and DNA methylome in three metabolic tissues of adult and aged mice. Transcriptome and methylome changes dominate the liver aging footprint, whereas heart and muscle globally increase chromatin accessibility, especially in aging pathways. In mouse and human data from multiple tissues and regulatory layers, age-related transcription factor expression changes and binding site enrichment converge on putative aging modulators, including ZIC1, CXXC1, HMGA1, MECP2, SREBF1, SREBF2, ETS2, ZBTB7A, and ZNF518B. Using Mendelian randomization, we establish possible epidemiological links between expression of some of these transcription factors or their targets, including CXXC1, ZNF518B, and BBC3, and longevity. We conclude that conserved modulators are at the core of the molecular footprint of aging, and variation in tissue-specific expression of some may affect human longevity.
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Affiliation(s)
- Maroun Bou Sleiman
- Laboratory of Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Pooja Jha
- Laboratory of Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Riekelt Houtkooper
- Laboratory of Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Robert W Williams
- Department of Genetics, Genomics and Informatics, University of Tennessee, Memphis, TN 38163, USA
| | - Xu Wang
- Laboratory of Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland.
| | - Johan Auwerx
- Laboratory of Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland.
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15
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Zhu Y, Ji J, Lin W, Li M, Liu L, Zhu H, Xue F, Li X, Zhou X, Yuan Z. MCC-SP: a powerful integration method for identification of causal pathways from genetic variants to complex disease. BMC Genet 2020; 21:90. [PMID: 32847502 PMCID: PMC7477886 DOI: 10.1186/s12863-020-00899-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/13/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Genome-wide association studies (GWAS) have successfully identified genetic susceptible variants for complex diseases. However, the underlying mechanism of such association remains largely unknown. Most disease-associated genetic variants have been shown to reside in noncoding regions, leading to the hypothesis that regulation of gene expression may be the primary biological mechanism. Current methods to characterize gene expression mediating the effect of genetic variant on diseases, often analyzed one gene at a time and ignored the network structure. The impact of genetic variant can propagate to other genes along the links in the network, then to the final disease. There could be multiple pathways from the genetic variant to the final disease, with each having the chain structure since the first node is one specific SNP (Single Nucleotide Polymorphism) variant and the end is disease outcome. One key but inadequately addressed question is how to measure the between-node connection strength and rank the effects of such chain-type pathways, which can provide statistical evidence to give the priority of some pathways for potential drug development in a cost-effective manner. RESULTS We first introduce the maximal correlation coefficient (MCC) to represent the between-node connection, and then integrate MCC with K shortest paths algorithm to rank and identify the potential pathways from genetic variant to disease. The pathway importance score (PIS) was further provided to quantify the importance of each pathway. We termed this method as "MCC-SP". Various simulations are conducted to illustrate MCC is a better measurement of the between-node connection strength than other quantities including Pearson correlation, Spearman correlation, distance correlation, mutual information, and maximal information coefficient. Finally, we applied MCC-SP to analyze one real dataset from the Religious Orders Study and the Memory and Aging Project, and successfully detected 2 typical pathways from APOE genotype to Alzheimer's disease (AD) through gene expression enriched in Alzheimer's disease pathway. CONCLUSIONS MCC-SP has powerful and robust performance in identifying the pathway(s) from the genetic variant to the disease. The source code of MCC-SP is freely available at GitHub ( https://github.com/zhuyuchen95/ADnet ).
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Affiliation(s)
- Yuchen Zhu
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong China
| | - Jiadong Ji
- Department of Data Science, School of Statistics, Shandong University of Finance and Economics, Jinan, 250014 China
| | - Weiqiang Lin
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong China
| | - Mingzhuo Li
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong China
| | - Lu Liu
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong China
| | - Huanhuan Zhu
- Department of Biostatistics, University of Michigan, Ann Arbor, MI 48109 USA
- Center for Statistical Genetics, University of Michigan, Ann Arbor, MI 48109 USA
| | - Fuzhong Xue
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong China
| | - Xiujun Li
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong China
| | - Xiang Zhou
- Department of Biostatistics, University of Michigan, Ann Arbor, MI 48109 USA
- Center for Statistical Genetics, University of Michigan, Ann Arbor, MI 48109 USA
| | - Zhongshang Yuan
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong China
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16
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Rittiner JE, Moncalvo M, Chiba-Falek O, Kantor B. Gene-Editing Technologies Paired With Viral Vectors for Translational Research Into Neurodegenerative Diseases. Front Mol Neurosci 2020; 13:148. [PMID: 32903507 PMCID: PMC7437156 DOI: 10.3389/fnmol.2020.00148] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 07/16/2020] [Indexed: 12/20/2022] Open
Abstract
Diseases of the central nervous system (CNS) have historically been among the most difficult to treat using conventional pharmacological approaches. This is due to a confluence of factors, including the limited regenerative capacity and overall complexity of the brain, problems associated with repeated drug administration, and difficulties delivering drugs across the blood-brain barrier (BBB). Viral-mediated gene transfer represents an attractive alternative for the delivery of therapeutic cargo to the nervous system. Crucially, it usually requires only a single injection, whether that be a gene replacement strategy for an inherited disorder or the delivery of a genome- or epigenome-modifying construct for treatment of CNS diseases and disorders. It is thus understandable that considerable effort has been put towards the development of improved vector systems for gene transfer into the CNS. Different viral vectors are of course tailored to their specific applications, but they generally should share several key properties. The ideal viral vector incorporates a high-packaging capacity, efficient gene transfer paired with robust and sustained expression, lack of oncogenicity, toxicity and pathogenicity, and scalable manufacturing for clinical applications. In this review, we will devote attention to viral vectors derived from human immunodeficiency virus type 1 (lentiviral vectors; LVs) and adeno-associated virus (AAVs). The high interest in these viral delivery systems vectors is due to: (i) robust delivery and long-lasting expression; (ii) efficient transduction into postmitotic cells, including the brain; (iii) low immunogenicity and toxicity; and (iv) compatibility with advanced manufacturing techniques. Here, we will outline basic aspects of LV and AAV biology, particularly focusing on approaches and techniques aiming to enhance viral safety. We will also allocate a significant portion of this review to the development and use of LVs and AAVs for delivery into the CNS, with a focus on the genome and epigenome-editing tools based on clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas 9) and the development of novel strategies for the treatment of neurodegenerative diseases (NDDs).
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Affiliation(s)
- Joseph Edward Rittiner
- Department of Neurobiology, Duke University Medical Center, Durham, NC, United States
- Viral Vector Core, Duke University Medical Center, Durham, NC, United States
- Duke Center for Advanced Genomic Technologies, Durham, NC, United States
| | - Malik Moncalvo
- Department of Neurobiology, Duke University Medical Center, Durham, NC, United States
- Viral Vector Core, Duke University Medical Center, Durham, NC, United States
- Duke Center for Advanced Genomic Technologies, Durham, NC, United States
| | - Ornit Chiba-Falek
- Department of Neurology, Division of Translational Brain Sciences, Duke University Medical Center, Durham, NC, United States
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, United States
| | - Boris Kantor
- Department of Neurobiology, Duke University Medical Center, Durham, NC, United States
- Viral Vector Core, Duke University Medical Center, Durham, NC, United States
- Duke Center for Advanced Genomic Technologies, Durham, NC, United States
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17
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Dagan H, Flashner-Abramson E, Vasudevan S, Jubran MR, Cohen E, Kravchenko-Balasha N. Exploring Alzheimer's Disease Molecular Variability via Calculation of Personalized Transcriptional Signatures. Biomolecules 2020; 10:biom10040503. [PMID: 32225014 PMCID: PMC7226317 DOI: 10.3390/biom10040503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 12/27/2022] Open
Abstract
Despite huge investments and major efforts to develop remedies for Alzheimer’s disease (AD) in the past decades, AD remains incurable. While evidence for molecular and phenotypic variability in AD have been accumulating, AD research still heavily relies on the search for AD-specific genetic/protein biomarkers that are expected to exhibit repetitive patterns throughout all patients. Thus, the classification of AD patients to different categories is expected to set the basis for the development of therapies that will be beneficial for subpopulations of patients. Here we explore the molecular heterogeneity among a large cohort of AD and non-demented brain samples, aiming to address the question whether AD-specific molecular biomarkers can progress our understanding of the disease and advance the development of anti-AD therapeutics. We studied 951 brain samples, obtained from up to 17 brain regions of 85 AD patients and 22 non-demented subjects. Utilizing an information-theoretic approach, we deciphered the brain sample-specific structures of altered transcriptional networks. Our in-depth analysis revealed that 7 subnetworks were repetitive in the 737 diseased and 214 non-demented brain samples. Each sample was characterized by a subset consisting of ~1–3 subnetworks out of 7, generating 52 distinct altered transcriptional signatures that characterized the 951 samples. We show that 30 different altered transcriptional signatures characterized solely AD samples and were not found in any of the non-demented samples. In contrast, the rest of the signatures characterized different subsets of sample types, demonstrating the high molecular variability and complexity of gene expression in AD. Importantly, different AD patients exhibiting similar expression levels of AD biomarkers harbored distinct altered transcriptional networks. Our results emphasize the need to expand the biomarker-based stratification to patient-specific transcriptional signature identification for improved AD diagnosis and for the development of subclass-specific future treatment.
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Affiliation(s)
- Hila Dagan
- The Rachel and Selim Benin School of Computer Science and Engineering, Hebrew University, Jerusalem 9190416, Israel;
| | - Efrat Flashner-Abramson
- Department for Bio-Medical Research, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel; (E.F.-A.); (S.V.); (M.R.J.)
| | - Swetha Vasudevan
- Department for Bio-Medical Research, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel; (E.F.-A.); (S.V.); (M.R.J.)
| | - Maria R. Jubran
- Department for Bio-Medical Research, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel; (E.F.-A.); (S.V.); (M.R.J.)
| | - Ehud Cohen
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel—Canada, The Hebrew University School of Medicine, Jerusalem 9112102, Israel;
| | - Nataly Kravchenko-Balasha
- Department for Bio-Medical Research, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel; (E.F.-A.); (S.V.); (M.R.J.)
- Correspondence:
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18
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Lee EG, Tulloch J, Chen S, Leong L, Saxton AD, Kraemer B, Darvas M, Keene CD, Shutes-David A, Todd K, Millard S, Yu CE. Redefining transcriptional regulation of the APOE gene and its association with Alzheimer's disease. PLoS One 2020; 15:e0227667. [PMID: 31978088 PMCID: PMC6980611 DOI: 10.1371/journal.pone.0227667] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/24/2019] [Indexed: 01/09/2023] Open
Abstract
The apolipoprotein E gene (APOE) is the strongest genetic risk factor for late-onset Alzheimer's disease (AD), yet the expression of APOE is not clearly understood. For example, it is unclear whether AD patients have elevated or decreased APOE expression or why the correlation levels of APOE RNA and the ApoE protein differ across studies. Likewise, APOE has a single CpG island (CGI) that overlaps with its 3'-exon, and this CGI's effect is unknown. We previously reported that the APOE CGI is highly methylated in human postmortem brain (PMB) and that this methylation is altered in AD frontal lobe. In this study, we comprehensively characterized APOE RNA transcripts and correlated levels of RNA expression with DNA methylation levels across the APOE CGI. We discovered the presence of APOE circular RNA (circRNA) and found that circRNA and full-length mRNA each constitute approximately one third of the total APOE RNA, with truncated mRNAs likely constituting some of the missing fraction. All APOE RNA species demonstrated significantly higher expression in AD frontal lobe than in control frontal lobe. Furthermore, we observed a negative correlation between the levels of total APOE RNA and DNA methylation at the APOE CGI in the frontal lobe. When stratified by disease status, this correlation was strengthened in controls but not in AD. Our findings suggest a possible modified mechanism of gene action for APOE in AD that involves not only the protein isoforms but also an epigenetically regulated transcriptional program driven by DNA methylation in the APOE CGI.
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Affiliation(s)
- Eun-Gyung Lee
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Jessica Tulloch
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Sunny Chen
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Lesley Leong
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Aleen D. Saxton
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Brian Kraemer
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
- Department of Medicine, University of Washington, Seattle, WA, United States of America
| | - Martin Darvas
- Department of Pathology, University of Washington, Seattle, WA, United States of America
| | - C. Dirk Keene
- Department of Pathology, University of Washington, Seattle, WA, United States of America
| | - Andrew Shutes-David
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Kaitlin Todd
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Steve Millard
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Chang-En Yu
- Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States of America
- Department of Medicine, University of Washington, Seattle, WA, United States of America
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19
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Volkman R, Ben-Zur T, Kahana A, Garty BZ, Offen D. Myeloperoxidase Deficiency Inhibits Cognitive Decline in the 5XFAD Mouse Model of Alzheimer's Disease. Front Neurosci 2019; 13:990. [PMID: 31611761 PMCID: PMC6769081 DOI: 10.3389/fnins.2019.00990] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 09/03/2019] [Indexed: 12/21/2022] Open
Abstract
Myeloperoxidase (MPO) is an enzyme expressed mostly by neutrophils and is a primary mediator of neutrophils oxidative stress response. While a profound body of evidence associates neutrophil-derived MPO in the pathogenesis of Alzheimer’s disease (AD), this role has not been assessed in an animal model of AD. Here, we produced hematologic chimerism in the 5XFAD mouse model of AD, with MPO deficient mice, resulting in 5XFAD with hematologic MPO deficiency (5XFAD-MPO KO). Behavioral examinations of 5XFAD-MPO KO showed significant superior performance in spatial learning and memory, associative learning, and anxiety/risk assessment behavior, as compared to 5XFAD mice transplanted with WT cells (5XFAD-WT). Hippocampal immunohistochemical and mRNA expression analyses showed significantly reduced levels of inflammatory mediators in 5XFAD-MPO KO mice with no apparent differences in the numbers of amyloid-β plaques. In addition, immunoblotting and mRNA analyses showed significantly reduced levels of APOE in 5XFAD-MPO KO. Together, these results indicate a substantial involvement of neutrophil-derived MPO in the pathology of 5XFAD model of AD and suggest MPO as a potential therapeutic target in AD.
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Affiliation(s)
- Rotem Volkman
- Department of Human Genetics and Biochemistry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tali Ben-Zur
- Department of Human Genetics and Biochemistry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | | | - Daniel Offen
- Department of Human Genetics and Biochemistry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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20
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Govindarajulu M, Pinky PD, Bloemer J, Ghanei N, Suppiramaniam V, Amin R. Signaling Mechanisms of Selective PPAR γ Modulators in Alzheimer's Disease. PPAR Res 2018; 2018:2010675. [PMID: 30420872 PMCID: PMC6215547 DOI: 10.1155/2018/2010675] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/31/2018] [Accepted: 09/13/2018] [Indexed: 01/22/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease characterized by abnormal protein accumulation, synaptic dysfunction, and cognitive impairment. The continuous increase in the incidence of AD with the aged population and mortality rate indicates the urgent need for establishing novel molecular targets for therapeutic potential. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists such as rosiglitazone and pioglitazone reduce amyloid and tau pathologies, inhibit neuroinflammation, and improve memory impairments in several rodent models and in humans with mild-to-moderate AD. However, these agonists display poor blood brain barrier permeability resulting in inadequate bioavailability in the brain and thus requiring high dosing with chronic time frames. Furthermore, these dosing levels are associated with several adverse effects including increased incidence of weight gain, liver abnormalities, and heart failure. Therefore, there is a need for identifying novel compounds which target PPARγ more selectively in the brain and could provide therapeutic benefits without a high incidence of adverse effects. This review focuses on how PPARγ agonists influence various pathologies in AD with emphasis on development of novel selective PPARγ modulators.
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Affiliation(s)
- Manoj Govindarajulu
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Priyanka D. Pinky
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Jenna Bloemer
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Nila Ghanei
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Vishnu Suppiramaniam
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
- Center for Neuroscience, Auburn University, Auburn, AL, USA
| | - Rajesh Amin
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
- Center for Neuroscience, Auburn University, Auburn, AL, USA
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Chiba-Falek O, Lutz MW. Towards precision medicine in Alzheimer's disease: deciphering genetic data to establish informative biomarkers. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2017; 2:47-55. [PMID: 28944295 DOI: 10.1080/23808993.2017.1286227] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Developing biomarker tools for identification of individuals at high-risk for late-onset Alzheimer's disease (LOAD) is important for prognosis and early treatment. This review focuses on genetic factors and their potential role for precision medicine in LOAD. AREAS COVERED APOEe4 is the strongest genetic risk factor for non-Mendelian LOAD, and the APOE-linkage disequilibrium (LD) region has produced the most significant association signal in multi-center genome-wide-association-studies (GWAS). Consideration of extended haplotypes in the APOE-LD region and specifically, non-coding variants in putative enhancer elements, such as the TOMM40-polyT, in-addition to the coding variants that comprise the APOE-genotypes, may be useful for predicting subjects at high-risk of developing LOAD and estimating age-of-onset of early disease-stage symptoms. A genetic-biomarker based on APOE-TOMM40-polyT haplotypes, and age is currently applied in a clinical trial for prevention/delay of LOAD onset. Additionally, we discuss LOAD-GWAS discoveries and the development of new genetic risk scores based on LOAD-GWAS findings other than the APOE-LD region. EXPERT COMMENTARY Deciphering the precise causal genetic-variants within LOAD-GWAS regions will advance the development of genetic-biomarkers to complement and refine the APOE-LD region based prediction model. Collectively, the genetic-biomarkers will be translational for early diagnosis and enrichment of clinical trials with subjects at high-risk.
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Affiliation(s)
- Ornit Chiba-Falek
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA.,Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael W Lutz
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
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The effects of PPARγ on the regulation of the TOMM40-APOE-C1 genes cluster. Biochim Biophys Acta Mol Basis Dis 2017; 1863:810-816. [PMID: 28065845 DOI: 10.1016/j.bbadis.2017.01.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 12/12/2016] [Accepted: 01/04/2017] [Indexed: 11/24/2022]
Abstract
Chromosome 19q13.32 is a gene rich region, and has been implicated in multiple human phenotypes in adulthood including lipids traits, Alzheimer's disease, and longevity. Peroxisome Proliferator Activated Receptor Gamma (PPARγ) is a ligand-activated nuclear transcription factor that plays a role in human complex traits that are also genetically associated with the chromosome 19q13.32 region. Here, we study the effects of PPARγ on the regional expression regulation of the genes clustered within chromosome 19q13.32, specifically TOMM40, APOE, and APOC1, applying two complementary approaches. Using the short hairpin RNA (shRNA) method in the HepG2 cell-line we knocked down PPARγ expression and measured the effect on mRNA expression. We discovered PPARγ knock down increased the levels of TOMM40-, APOE-, and APOC1-mRNAs, with the highest increase in expression observed for APOE-mRNA. To complement the PPARγ knockdown findings we also examined the effects of low doses of PPARγ agonists (nM range) on mRNA expression of these genes. Low (nM) concentrations of pioglitazone (Pio) decreased transcription of TOMM40, APOE, and APOC1 genes, with the lowest mRNA levels for each gene observed at 1.5nM. Similar to the effect of PPARγ knockdown, the strongest response to pioglitazone was also observed for APOE-mRNA, and rosiglitazone (Rosi), another PPARγ agonist, produced results that were consistent with these. In conclusion, our results further established a role for PPARγ in regional transcriptional regulation of chr19q13.32, underpinning the association between PPARγ, the chr19q13.32 genes cluster, and human complex traits and disease.
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