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Jiang K, Liu T, Kales S, Tewhey R, Kim D, Park Y, Jarvis JN. A systematic strategy for identifying causal single nucleotide polymorphisms and their target genes on Juvenile arthritis risk haplotypes. BMC Med Genomics 2024; 17:185. [PMID: 38997781 PMCID: PMC11241977 DOI: 10.1186/s12920-024-01954-z] [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: 04/15/2024] [Accepted: 06/27/2024] [Indexed: 07/14/2024] Open
Abstract
BACKGROUND Although genome-wide association studies (GWAS) have identified multiple regions conferring genetic risk for juvenile idiopathic arthritis (JIA), we are still faced with the task of identifying the single nucleotide polymorphisms (SNPs) on the disease haplotypes that exert the biological effects that confer risk. Until we identify the risk-driving variants, identifying the genes influenced by these variants, and therefore translating genetic information to improved clinical care, will remain an insurmountable task. We used a function-based approach for identifying causal variant candidates and the target genes on JIA risk haplotypes. METHODS We used a massively parallel reporter assay (MPRA) in myeloid K562 cells to query the effects of 5,226 SNPs in non-coding regions on JIA risk haplotypes for their ability to alter gene expression when compared to the common allele. The assay relies on 180 bp oligonucleotide reporters ("oligos") in which the allele of interest is flanked by its cognate genomic sequence. Barcodes were added randomly by PCR to each oligo to achieve > 20 barcodes per oligo to provide a quantitative read-out of gene expression for each allele. Assays were performed in both unstimulated K562 cells and cells stimulated overnight with interferon gamma (IFNg). As proof of concept, we then used CRISPRi to demonstrate the feasibility of identifying the genes regulated by enhancers harboring expression-altering SNPs. RESULTS We identified 553 expression-altering SNPs in unstimulated K562 cells and an additional 490 in cells stimulated with IFNg. We further filtered the SNPs to identify those plausibly situated within functional chromatin, using open chromatin and H3K27ac ChIPseq peaks in unstimulated cells and open chromatin plus H3K4me1 in stimulated cells. These procedures yielded 42 unique SNPs (total = 84) for each set. Using CRISPRi, we demonstrated that enhancers harboring MPRA-screened variants in the TRAF1 and LNPEP/ERAP2 loci regulated multiple genes, suggesting complex influences of disease-driving variants. CONCLUSION Using MPRA and CRISPRi, JIA risk haplotypes can be queried to identify plausible candidates for disease-driving variants. Once these candidate variants are identified, target genes can be identified using CRISPRi informed by the 3D chromatin structures that encompass the risk haplotypes.
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Affiliation(s)
- Kaiyu Jiang
- Department of Pediatrics, Clinical and Translational Research Center, University at Buffalo Jacobs School of Medicine School Medicine & Biomedical Sciences, 701 Ellicott St, Buffalo, NY, 14203, USA
| | - Tao Liu
- Roswell Park Cancer Institute, 665 Elm St, Buffalo, NY, 14203, USA
| | - Susan Kales
- Jackson Laboratories, 600 Main St, Bar Harbor, ME, 04609, USA
| | - Ryan Tewhey
- Jackson Laboratories, 600 Main St, Bar Harbor, ME, 04609, USA
| | - Dongkyeong Kim
- Department of Biochemistry, University at Buffalo Jacobs School of Medicine School Medicine & Biomedical Sciences, 955 Main St, Buffalo, NY, 14203, USA
| | - Yungki Park
- Department of Biochemistry, University at Buffalo Jacobs School of Medicine School Medicine & Biomedical Sciences, 955 Main St, Buffalo, NY, 14203, USA
- Genetics, Genomics, & Bioinformatics Program, University at Buffalo Jacobs School of Medicine School Medicine & Biomedical Sciences, 955 Main St, Buffalo, NY, 14203, USA
| | - James N Jarvis
- Department of Pediatrics, Clinical and Translational Research Center, University at Buffalo Jacobs School of Medicine School Medicine & Biomedical Sciences, 701 Ellicott St, Buffalo, NY, 14203, USA.
- Genetics, Genomics, & Bioinformatics Program, University at Buffalo Jacobs School of Medicine School Medicine & Biomedical Sciences, 955 Main St, Buffalo, NY, 14203, USA.
- University of Washington Rheumatology Research, 750 Republican St., E520, Seattle, WA, 98109, USA.
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Fan C, An H, Kim D, Park Y. Uncovering oligodendrocyte enhancers that control Cnp expression. Hum Mol Genet 2023; 32:3225-3236. [PMID: 37642363 PMCID: PMC10656706 DOI: 10.1093/hmg/ddad141] [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: 06/01/2023] [Revised: 08/05/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Oligodendrocytes (OLs) produce myelin sheaths around axons in the central nervous system (CNS). Myelin accelerates the propagation of action potentials along axons and supports the integrity of axons. Impaired myelination has been linked to neurological and neuropsychiatric disorders. As a major component of CNS myelin, 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) plays an indispensable role in the axon-supportive function of myelin. Notably, this function requires a high-level expression of CNP in OLs, as evidenced by downregulated expression of CNP in mental disorders and animal models. Little is known about how CNP expression is regulated in OLs. Especially, OL enhancers that govern CNP remain elusive. We have recently developed a powerful method that links OL enhancers to target genes in a principled manner. Here, we applied it to Cnp, uncovering two OL enhancers for it (termed Cnp-E1 and Cnp-E2). Epigenome editing analysis revealed that Cnp-E1 and Cnp-E2 are dedicated to Cnp. ATAC-seq and ChIP-seq data show that Cnp-E1 and Cnp-E2 are conserved OL-specific enhancers. Single cell multi-omics data that jointly profile gene expression and chromatin accessibility suggest that Cnp-E2 plays an important role in Cnp expression in the early stage of OL differentiation while Cnp-E1 sustains it in mature OLs.
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Affiliation(s)
- Chuandong Fan
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
| | - Hongjoo An
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
| | - Dongkyeong Kim
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Yungki Park
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, NY 14203, United States
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Fan C, Kim D, An H, Park Y. Identifying an oligodendrocyte enhancer that regulates Olig2 expression. Hum Mol Genet 2023; 32:835-846. [PMID: 36193754 PMCID: PMC9941837 DOI: 10.1093/hmg/ddac249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 09/26/2022] [Accepted: 09/30/2022] [Indexed: 11/14/2022] Open
Abstract
Olig2 is a basic helix-loop-helix transcription factor that plays a critical role in the central nervous system. It directs the specification of motor neurons and oligodendrocyte precursor cells (OPCs) from neural progenitors and the subsequent maturation of OPCs into myelin-forming oligodendrocytes (OLs). It is also required for the development of astrocytes. Despite a decade-long search, enhancers that regulate the expression of Olig2 remain elusive. We have recently developed an innovative method that maps promoter-distal enhancers to genes in a principled manner. Here, we applied it to Olig2 in the context of OL lineage cells, uncovering an OL enhancer for it (termed Olig2-E1). Silencing Olig2-E1 by CRISPRi epigenome editing significantly downregulated Olig2 expression. Luciferase assay and ATAC-seq and ChIP-seq data show that Olig2-E1 is an OL-specific enhancer that is conserved across human, mouse and rat. Hi-C data reveal that Olig2-E1 physically interacts with OLIG2 and suggest that this interaction is specific to OL lineage cells. In sum, Olig2-E1 is an evolutionarily conserved OL-specific enhancer that drives the expression of Olig2.
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Affiliation(s)
- Chuandong Fan
- Institute for Myelin and Glia Exploration, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Dongkyeong Kim
- Institute for Myelin and Glia Exploration, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA.,Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | - Yungki Park
- Institute for Myelin and Glia Exploration, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
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Kim D, An H, Fan C, Park Y. Identifying oligodendrocyte enhancers governing Plp1 expression. Hum Mol Genet 2021; 30:2225-2239. [PMID: 34230963 PMCID: PMC8600034 DOI: 10.1093/hmg/ddab184] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 11/13/2022] Open
Abstract
Oligodendrocytes (OLs) produce myelin in the central nervous system (CNS), which accelerates the propagation of action potentials and supports axonal integrity. As a major component of CNS myelin, proteolipid protein 1 (Plp1) is indispensable for the axon-supportive function of myelin. Notably, this function requires the continuous high-level expression of Plp1 in OLs. Equally important is the controlled expression of Plp1, as illustrated by Pelizaeus-Merzbacher disease for which the most common cause is PLP1 overexpression. Despite a decade-long search, promoter-distal OL enhancers that govern Plp1 remain elusive. We have recently developed an innovative method that maps promoter-distal enhancers to genes in a principled manner. Here, we applied it to Plp1, uncovering two OL enhancers for it (termed Plp1-E1 and Plp1-E2). Remarkably, clustered regularly interspaced short palindromic repeats (CRISPR) interference epigenome editing showed that Plp1-E1 and Plp1-E2 do not regulate two genes in their vicinity, highlighting their exquisite specificity to Plp1. Assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq) data show that Plp1-E1 and Plp1-E2 are OL-specific enhancers that are conserved among human, mouse and rat. Hi-C data reveal that the physical interactions between Plp1-E1/2 and PLP1 are among the strongest in OLs and specific to OLs. We also show that Myrf, a master regulator of OL development, acts on Plp1-E1 and Plp1-E2 to promote Plp1 expression.
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Affiliation(s)
- Dongkyeong Kim
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Hongjoo An
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Chuandong Fan
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Yungki Park
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
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Guo Z, Chen M, Chao Y, Cai C, Liu L, Zhao L, Li L, Bai QR, Xu Y, Niu W, Shi L, Bi Y, Ren D, Yuan F, Shi S, Zeng Q, Han K, Shi Y, Bian S, He G. RGCC balances self-renewal and neuronal differentiation of neural stem cells in the developing mammalian neocortex. EMBO Rep 2021; 22:e51781. [PMID: 34323349 DOI: 10.15252/embr.202051781] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 06/14/2021] [Accepted: 06/16/2021] [Indexed: 11/09/2022] Open
Abstract
During neocortical development, neural stem cells (NSCs) divide symmetrically to self-renew at the early stage and then divide asymmetrically to generate post-mitotic neurons. The molecular mechanisms regulating the balance between NSC self-renewal and neurogenesis are not fully understood. Using mouse in utero electroporation (IUE) technique and in vitro human NSC differentiation models including cerebral organoids (hCOs), we show here that regulator of cell cycle (RGCC) modulates NSC self-renewal and neuronal differentiation by affecting cell cycle regulation and spindle orientation. RGCC deficiency hampers normal cell cycle process and dysregulates the mitotic spindle, thus driving more cells to divide asymmetrically. These modulations diminish the NSC population and cause NSC pre-differentiation that eventually leads to brain developmental malformation in hCOs. We further show that RGCC might regulate NSC spindle orientation by affecting the organization of centrosome and microtubules. Our results demonstrate that RGCC is essential to maintain the NSC pool during cortical development and suggest that RGCC defects could have etiological roles in human brain malformations.
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Affiliation(s)
- Zhenming Guo
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Mengxia Chen
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yiming Chao
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Chunhai Cai
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Liangjie Liu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Li Zhao
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Linbo Li
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Qing-Ran Bai
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yanxin Xu
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Weibo Niu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Lei Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Yan Bi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Decheng Ren
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Fan Yuan
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Shuyue Shi
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Qian Zeng
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ke Han
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Yi Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Shan Bian
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Guang He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
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