1
|
Padmaswari MH, Bulliard G, Agrawal S, Jia MS, Khadgi S, Murach KA, Nelson CE. Precision and efficacy of RNA-guided DNA integration in high-expressing muscle loci. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102320. [PMID: 39398225 PMCID: PMC11466678 DOI: 10.1016/j.omtn.2024.102320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 08/30/2024] [Indexed: 10/15/2024]
Abstract
Gene replacement therapies primarily rely on adeno-associated virus (AAV) vectors for transgene expression. However, episomal expression can decline over time due to vector loss or epigenetic silencing. CRISPR-based integration methods offer promise for long-term transgene insertion. While the development of transgene integration methods has made substantial progress, identifying optimal insertion loci remains challenging. Skeletal muscle is a promising tissue for gene replacement owing to low invasiveness of intramuscular injections, relative proportion of body mass, the multinucleated nature of muscle, and the potential for reduced adverse effects. Leveraging endogenous promoters in skeletal muscle, we evaluated two highly expressing loci using homology-independent targeted integration (HITI) to integrate reporter or therapeutic genes in mouse myoblasts and skeletal muscle tissue. We hijacked the muscle creatine kinase (Ckm) and myoglobin (Mb) promoters by co-delivering CRISPR-Cas9 and a donor plasmid with promoterless constructs encoding green fluorescent protein (GFP) or human Factor IX (hFIX). Additionally, we deeply profiled our genome and transcriptome outcomes from targeted integration and evaluated the safety of the proposed sites. This study introduces a proof-of-concept technology for achieving high-level therapeutic gene expression in skeletal muscle, with potential applications in targeted integration-based medicine and synthetic biology.
Collapse
Affiliation(s)
- Made Harumi Padmaswari
- Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA
- Cellular and Molecular Biology, University of Arkansas, Fayetteville, AR, USA
| | | | - Shilpi Agrawal
- Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA
| | - Mary S. Jia
- Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA
| | - Sabin Khadgi
- Exercise Science Research Center, Molecular Muscle Mass Regulation Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Kevin A. Murach
- Cellular and Molecular Biology, University of Arkansas, Fayetteville, AR, USA
- Exercise Science Research Center, Molecular Muscle Mass Regulation Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Christopher E. Nelson
- Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA
- Cellular and Molecular Biology, University of Arkansas, Fayetteville, AR, USA
| |
Collapse
|
2
|
Timalsina B, Lee S, Kaang BK. Advances in the labelling and selective manipulation of synapses. Nat Rev Neurosci 2024; 25:668-687. [PMID: 39174832 DOI: 10.1038/s41583-024-00851-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2024] [Indexed: 08/24/2024]
Abstract
Synapses are highly specialized neuronal structures that are essential for neurotransmission, and they are dynamically regulated throughout the lifetime. Although accumulating evidence indicates that these structures are crucial for information processing and storage in the brain, their precise roles beyond neurotransmission are yet to be fully appreciated. Genetically encoded fluorescent tools have deepened our understanding of synaptic structure and function, but developing an ideal methodology to selectively visualize, label and manipulate synapses remains challenging. Here, we provide an overview of currently available synapse labelling techniques and describe their extension to enable synapse manipulation. We categorize these approaches on the basis of their conceptual bases and target molecules, compare their advantages and limitations and propose potential modifications to improve their effectiveness. These methods have broad utility, particularly for investigating mechanisms of synaptic function and synaptopathy.
Collapse
Affiliation(s)
- Binod Timalsina
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Sangkyu Lee
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Bong-Kiun Kaang
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea.
| |
Collapse
|
3
|
Gao Y, Shonai D, Trn M, Zhao J, Soderblom EJ, Garcia-Moreno SA, Gersbach CA, Wetsel WC, Dawson G, Velmeshev D, Jiang YH, Sloofman LG, Buxbaum JD, Soderling SH. Proximity analysis of native proteomes reveals phenotypic modifiers in a mouse model of autism and related neurodevelopmental conditions. Nat Commun 2024; 15:6801. [PMID: 39122707 PMCID: PMC11316102 DOI: 10.1038/s41467-024-51037-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 07/23/2024] [Indexed: 08/12/2024] Open
Abstract
One of the main drivers of autism spectrum disorder is risk alleles within hundreds of genes, which may interact within shared but unknown protein complexes. Here we develop a scalable genome-editing-mediated approach to target 14 high-confidence autism risk genes within the mouse brain for proximity-based endogenous proteomics, achieving the identification of high-specificity spatial proteomes. The resulting native proximity proteomes are enriched for human genes dysregulated in the brain of autistic individuals, and reveal proximity interactions between proteins from high-confidence risk genes with those of lower-confidence that may provide new avenues to prioritize genetic risk. Importantly, the datasets are enriched for shared cellular functions and genetic interactions that may underlie the condition. We test this notion by spatial proteomics and CRISPR-based regulation of expression in two autism models, demonstrating functional interactions that modulate mechanisms of their dysregulation. Together, these results reveal native proteome networks in vivo relevant to autism, providing new inroads for understanding and manipulating the cellular drivers underpinning its etiology.
Collapse
Affiliation(s)
- Yudong Gao
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Daichi Shonai
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, USA
| | - Matthew Trn
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
| | - Jieqing Zhao
- Department of Biology, Duke University, Durham, NC, USA
| | - Erik J Soderblom
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
- Proteomics and Metabolomics Shared Resource, Duke University School of Medicine, Durham, NC, USA
| | | | - Charles A Gersbach
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University, Durham, NC, USA
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - William C Wetsel
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University School of Medicine, Durham, NC, USA
| | - Geraldine Dawson
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Dmitry Velmeshev
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Yong-Hui Jiang
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Laura G Sloofman
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Joseph D Buxbaum
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Scott H Soderling
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA.
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA.
| |
Collapse
|
4
|
Moffa JC, Bland IN, Tooley JR, Kalyanaraman V, Heitmeier M, Creed MC, Copits BA. Cell-Specific Single Viral Vector CRISPR/Cas9 Editing and Genetically Encoded Tool Delivery in the Central and Peripheral Nervous Systems. eNeuro 2024; 11:ENEURO.0438-23.2024. [PMID: 38871457 PMCID: PMC11228695 DOI: 10.1523/eneuro.0438-23.2024] [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: 10/24/2023] [Revised: 03/20/2024] [Accepted: 04/18/2024] [Indexed: 06/15/2024] Open
Abstract
CRISPR/Cas9 gene editing represents an exciting avenue to study genes of unknown function and can be combined with genetically encoded tools such as fluorescent proteins, channelrhodopsins, DREADDs, and various biosensors to more deeply probe the function of these genes in different cell types. However, current strategies to also manipulate or visualize edited cells are challenging due to the large size of Cas9 proteins and the limited packaging capacity of adeno-associated viruses (AAVs). To overcome these constraints, we developed an alternative gene editing strategy using a single AAV vector and mouse lines that express Cre-dependent Cas9 to achieve efficient cell-type specific editing across the nervous system. Expressing Cre-dependent Cas9 from a genomic locus affords space to package guide RNAs for gene editing together with Cre-dependent, genetically encoded tools to manipulate, map, or monitor neurons using a single virus. We validated this strategy with three common tools in neuroscience: ChRonos, a channelrhodopsin, for studying synaptic transmission using optogenetics, GCaMP8f for recording Ca2+ transients using photometry, and mCherry for tracing axonal projections. We tested these tools in multiple brain regions and cell types, including GABAergic neurons in the nucleus accumbens, glutamatergic neurons projecting from the ventral pallidum to the lateral habenula, dopaminergic neurons in the ventral tegmental area, and proprioceptive neurons in the periphery. This flexible approach could help identify and test the function of novel genes affecting synaptic transmission, circuit activity, or morphology with a single viral injection.
Collapse
Affiliation(s)
- Jamie C Moffa
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110
- Washington University Medical Scientist Training Program, Washington University School of Medicine, St. Louis, Missouri 63110
| | - India N Bland
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Jessica R Tooley
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110
- Washington University Division of Biological and Behavioral Sciences, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Vani Kalyanaraman
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Monique Heitmeier
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Meaghan C Creed
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110
- Departments of Neuroscience, Psychiatry, and Biomedical Engineering, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Bryan A Copits
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110
| |
Collapse
|
5
|
Hao M, Ling X, Sun Y, Wang X, Li W, Chang L, Zeng Z, Shi X, Niu M, Chen L, Liu T. Tracking endogenous proteins based on RNA editing-mediated genetic code expansion. Nat Chem Biol 2024; 20:721-731. [PMID: 38302606 DOI: 10.1038/s41589-023-01533-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/19/2023] [Indexed: 02/03/2024]
Abstract
Protein labeling approaches are important to study proteins in living cells, and genome editing tools make it possible to tag endogenous proteins to address the concerns associated with overexpression. Here we established RNA editing-mediated noncanonical amino acids (ncAAs) protein tagging (RENAPT) to site-specifically label endogenous proteins with ncAAs in living cells. RENAPT labels protein in a temporary and nonheritable manner and is not restricted by protospacer adjacent motif sequence. Using a fluorescent ncAA or ncAA with a bio-orthogonal reaction handle for subsequent dye labeling, we demonstrated that a variety of endogenous proteins can be imaged at their specific subcellular locations. In addition, two proteins can be tagged individually and simultaneously using two different ncAAs. Furthermore, endogenous ion channels and neuron-specific proteins can be real-time labeled in primary neurons. Thus, RENAPT presents a promising platform with broad applicability for tagging endogenous proteins in living cells to study their localization and functions.
Collapse
Affiliation(s)
- Min Hao
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Xinyu Ling
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Yi Sun
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Xue Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Wenzhe Li
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Liying Chang
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Zhiying Zeng
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Xiaomeng Shi
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Mengxiao Niu
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, College of Future Technology, Peking University, Beijing, China
| | - Liangyi Chen
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, College of Future Technology, Peking University, Beijing, China
| | - Tao Liu
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China.
| |
Collapse
|
6
|
Deutz LN, Sarıkaya S, Dickinson DJ. Membrane extraction in native lipid nanodiscs reveals dynamic regulation of Cdc42 complexes during cell polarization. Biophys J 2023:S0006-3495(23)00721-X. [PMID: 38006206 DOI: 10.1016/j.bpj.2023.11.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/13/2023] [Accepted: 11/21/2023] [Indexed: 11/26/2023] Open
Abstract
Embryonic development requires the establishment of cell polarity to enable cell fate segregation and tissue morphogenesis. This process is regulated by Par complex proteins, which partition into polarized membrane domains and direct downstream polarized cell behaviors. The kinase aPKC (along with its cofactor Par6) is a key member of this network and can be recruited to the plasma membrane by either the small GTPase Cdc42 or the scaffolding protein Par3. Although in vitro interactions among these proteins are well established, much is still unknown about the complexes they form during development. Here, to enable the study of membrane-associated complexes ex vivo, we used a maleic acid copolymer to rapidly isolate membrane proteins from single C. elegans zygotes into lipid nanodiscs. We show that native lipid nanodisc formation enables detection of endogenous complexes involving Cdc42, which are undetectable when cells are lysed in detergent. We found that Cdc42 interacts more strongly with aPKC/Par6 during polarity maintenance than polarity establishment, two developmental stages that are separated by only a few minutes. We further show that Cdc42 and Par3 do not bind aPKC/Par6 simultaneously, confirming recent in vitro findings in an ex vivo context. Our findings establish a new tool for studying membrane-associated signaling complexes and reveal an unexpected mode of polarity regulation via Cdc42.
Collapse
Affiliation(s)
- Lars N Deutz
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
| | - Sena Sarıkaya
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
| | - Daniel J Dickinson
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas.
| |
Collapse
|
7
|
Balasubramanian H, Hobson CM, Chew TL, Aaron JS. Imagining the future of optical microscopy: everything, everywhere, all at once. Commun Biol 2023; 6:1096. [PMID: 37898673 PMCID: PMC10613274 DOI: 10.1038/s42003-023-05468-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/16/2023] [Indexed: 10/30/2023] Open
Abstract
The optical microscope has revolutionized biology since at least the 17th Century. Since then, it has progressed from a largely observational tool to a powerful bioanalytical platform. However, realizing its full potential to study live specimens is hindered by a daunting array of technical challenges. Here, we delve into the current state of live imaging to explore the barriers that must be overcome and the possibilities that lie ahead. We venture to envision a future where we can visualize and study everything, everywhere, all at once - from the intricate inner workings of a single cell to the dynamic interplay across entire organisms, and a world where scientists could access the necessary microscopy technologies anywhere.
Collapse
Affiliation(s)
| | - Chad M Hobson
- Advanced Imaging Center; Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, 20147, USA
| | - Teng-Leong Chew
- Advanced Imaging Center; Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, 20147, USA
| | - Jesse S Aaron
- Advanced Imaging Center; Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, 20147, USA.
| |
Collapse
|
8
|
Kumar S, Stainer A, Dubrulle J, Simpkins C, Cooper JA. Cas phosphorylation regulates focal adhesion assembly. eLife 2023; 12:e90234. [PMID: 37489578 PMCID: PMC10435235 DOI: 10.7554/elife.90234] [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: 06/16/2023] [Accepted: 07/19/2023] [Indexed: 07/26/2023] Open
Abstract
Integrin-mediated cell attachment rapidly induces tyrosine kinase signaling. Despite years of research, the role of this signaling in integrin activation and focal adhesion assembly is unclear. We provide evidence that the Src-family kinase (SFK) substrate Cas (Crk-associated substrate, p130Cas, BCAR1) is phosphorylated and associated with its Crk/CrkL effectors in clusters that are precursors of focal adhesions. The initial phospho-Cas clusters contain integrin β1 in its inactive, bent closed, conformation. Later, phospho-Cas and total Cas levels decrease as integrin β1 is activated and core focal adhesion proteins including vinculin, talin, kindlin, and paxillin are recruited. Cas is required for cell spreading and focal adhesion assembly in epithelial and fibroblast cells on collagen and fibronectin. Cas cluster formation requires Cas, Crk/CrkL, SFKs, and Rac1 but not vinculin. Rac1 provides positive feedback onto Cas through reactive oxygen, opposed by negative feedback from the ubiquitin proteasome system. The results suggest a two-step model for focal adhesion assembly in which clusters of phospho-Cas, effectors and inactive integrin β1 grow through positive feedback prior to integrin activation and recruitment of core focal adhesion proteins.
Collapse
Affiliation(s)
- Saurav Kumar
- Fred Hutchinson Cancer CenterSeattleUnited States
| | | | | | | | | |
Collapse
|
9
|
Shi Y, Kopparapu N, Ohler L, Dickinson DJ. Efficient and rapid fluorescent protein knock-in with universal donors in mouse embryonic stem cells. Development 2023; 150:dev201367. [PMID: 37129004 PMCID: PMC10233722 DOI: 10.1242/dev.201367] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 04/18/2023] [Indexed: 05/03/2023]
Abstract
Fluorescent protein (FP) tagging is a key method for observing protein distribution, dynamics and interaction with other proteins in living cells. However, the typical approach using overexpression of tagged proteins can perturb cell behavior and introduce localization artifacts. To preserve native expression, fluorescent proteins can be inserted directly into endogenous genes. This approach has been widely used in yeast for decades, and more recently in invertebrate model organisms with the advent of CRISPR/Cas9. However, endogenous FP tagging has not been widely used in mammalian cells due to inefficient homology-directed repair. Recently, the CRISPaint system used non-homologous end joining for efficient integration of FP tags into native loci, but it only allows C-terminal knock-ins. Here, we have enhanced the CRISPaint system by introducing new universal donors for N-terminal insertion and for multi-color tagging with orthogonal selection markers. We adapted the procedure for mouse embryonic stem cells, which can be differentiated into diverse cell types. Our protocol is rapid and efficient, enabling live imaging in less than 2 weeks post-transfection. These improvements increase the versatility and applicability of FP knock-in in mammalian cells.
Collapse
Affiliation(s)
- Yu Shi
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Nitya Kopparapu
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Lauren Ohler
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Daniel J. Dickinson
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| |
Collapse
|
10
|
Cromer MK, Majeti KR, Rettig GR, Murugan K, Kurgan GL, Bode NM, Hampton JP, Vakulskas CA, Behlke MA, Porteus MH. Comparative analysis of CRISPR off-target discovery tools following ex vivo editing of CD34 + hematopoietic stem and progenitor cells. Mol Ther 2023; 31:1074-1087. [PMID: 36793210 PMCID: PMC10124080 DOI: 10.1016/j.ymthe.2023.02.011] [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: 09/13/2022] [Revised: 01/11/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
While a number of methods exist to investigate CRISPR off-target (OT) editing, few have been compared head-to-head in primary cells after clinically relevant editing processes. Therefore, we compared in silico tools (COSMID, CCTop, and Cas-OFFinder) and empirical methods (CHANGE-Seq, CIRCLE-Seq, DISCOVER-Seq, GUIDE-Seq, and SITE-Seq) after ex vivo hematopoietic stem and progenitor cell (HSPC) editing. We performed editing using 11 different gRNAs complexed with Cas9 protein (high-fidelity [HiFi] or wild-type versions), then performed targeted next-generation sequencing of nominated OT sites identified by in silico and empirical methods. We identified an average of less than one OT site per guide RNA (gRNA) and all OT sites generated using HiFi Cas9 and a 20-nt gRNA were identified by all OT detection methods with the exception of SITE-seq. This resulted in high sensitivity for the majority of OT nomination tools and COSMID, DISCOVER-Seq, and GUIDE-Seq attained the highest positive predictive value (PPV). We found that empirical methods did not identify OT sites that were not also identified by bioinformatic methods. This study supports that refined bioinformatic algorithms could be developed that maintain both high sensitivity and PPV, thereby enabling more efficient identification of potential OT sites without compromising a thorough examination for any given gRNA.
Collapse
Affiliation(s)
- M Kyle Cromer
- Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center for Regeneration Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - Kiran R Majeti
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | | | - Karthik Murugan
- Integrated DNA Technologies, Inc., Coralville, IA 52241, USA
| | - Gavin L Kurgan
- Integrated DNA Technologies, Inc., Coralville, IA 52241, USA
| | - Nicole M Bode
- Integrated DNA Technologies, Inc., Coralville, IA 52241, USA
| | - Jessica P Hampton
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | | | - Mark A Behlke
- Integrated DNA Technologies, Inc., Coralville, IA 52241, USA
| | - Matthew H Porteus
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
11
|
Droogers WJ, MacGillavry HD. Plasticity of postsynaptic nanostructure. Mol Cell Neurosci 2023; 124:103819. [PMID: 36720293 DOI: 10.1016/j.mcn.2023.103819] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
The postsynaptic density (PSD) of excitatory synapses is built from a wide variety of scaffolding proteins, receptors, and signaling molecules that collectively orchestrate synaptic transmission. Seminal work over the past decades has led to the identification and functional characterization of many PSD components. In contrast, we know far less about how these constituents are assembled within synapses, and how this organization contributes to synapse function. Notably, recent evidence from high-resolution microscopy studies and in silico models, highlights the importance of the precise subsynaptic structure of the PSD for controlling the strength of synaptic transmission. Even further, activity-driven changes in the distribution of glutamate receptors are acknowledged to contribute to long-term changes in synaptic efficacy. Thus, defining the mechanisms that drive structural changes within the PSD are important for a molecular understanding of synaptic transmission and plasticity. Here, we review the current literature on how the PSD is organized to mediate basal synaptic transmission and how synaptic activity alters the nanoscale organization of synapses to sustain changes in synaptic strength.
Collapse
Affiliation(s)
- W J Droogers
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, The Netherlands
| | - H D MacGillavry
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, The Netherlands.
| |
Collapse
|
12
|
Giandomenico SL, Schuman EM. Genetic manipulation and targeted protein degradation in mammalian systems: practical considerations, tips and tricks for discovery research. FEBS Open Bio 2023. [PMID: 36815235 DOI: 10.1002/2211-5463.13581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 01/13/2023] [Accepted: 02/21/2023] [Indexed: 02/24/2023] Open
Abstract
Gaining a mechanistic understanding of the molecular pathways underpinning cellular and organismal physiology invariably relies on the perturbation of an experimental system to infer causality. This can be achieved either by genetic manipulation or by pharmacological treatment. Generally, the former approach is applicable to a wider range of targets, is more precise, and can address more nuanced functional aspects. Despite such apparent advantages, genetic manipulation (i.e., knock-down, knock-out, mutation, and tagging) in mammalian systems can be challenging due to problems with delivery, low rates of homologous recombination, and epigenetic silencing. The advent of CRISPR-Cas9 in combination with the development of robust differentiation protocols that can efficiently generate a variety of different cell types in vitro has accelerated our ability to probe gene function in a more physiological setting. Often, the main obstacle in this path of enquiry is to achieve the desired genetic modification. In this short review, we will focus on gene perturbation in mammalian cells and how editing and differentiation of pluripotent stem cells can complement more traditional approaches. Additionally, we introduce novel targeted protein degradation approaches as an alternative to DNA/RNA-based manipulation. Our aim is to present a broad overview of recent approaches and in vitro systems to study mammalian cell biology. Due to space limitations, we limit ourselves to providing the inexperienced reader with a conceptual framework on how to use these tools, and for more in-depth information, we will provide specific references throughout.
Collapse
Affiliation(s)
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| |
Collapse
|
13
|
Droogers WJ, Willems J, MacGillavry HD, de Jong APH. Duplex Labeling and Manipulation of Neuronal Proteins Using Sequential CRISPR/Cas9 Gene Editing. eNeuro 2022; 9:ENEURO.0056-22.2022. [PMID: 35851300 PMCID: PMC9333357 DOI: 10.1523/eneuro.0056-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 04/20/2022] [Accepted: 04/28/2022] [Indexed: 11/21/2022] Open
Abstract
CRISPR/Cas9-mediated knock-in methods enable the labeling of individual endogenous proteins to faithfully determine their spatiotemporal distribution in cells. However, reliable multiplexing of knock-in events in neurons remains challenging because of cross talk between editing events. To overcome this, we developed conditional activation of knock-in expression (CAKE), allowing efficient, flexible, and accurate multiplex genome editing in rat neurons. To diminish cross talk, CAKE is based on sequential, recombinase-driven guide RNA (gRNA) expression to control the timing of genomic integration of each donor sequence. We show that CAKE is broadly applicable to co-label various endogenous proteins, including cytoskeletal proteins, synaptic scaffolds, ion channels and neurotransmitter receptor subunits. To take full advantage of CAKE, we resolved the nanoscale co-distribution of endogenous synaptic proteins using super-resolution microscopy, demonstrating that their co-organization depends on synapse size. Finally, we introduced inducible dimerization modules, providing acute control over synaptic receptor dynamics in living neurons. These experiments highlight the potential of CAKE to reveal new biological insight. Altogether, CAKE is a versatile method for multiplex protein labeling that enables the detection, localization, and manipulation of endogenous proteins in neurons.Significance StatementAccurate localization and manipulation of endogenous proteins is essential to unravel neuronal function. While labeling of individual proteins is achievable with existing gene editing techniques, methods to label multiple proteins in neurons are limiting. We introduce a new CRISPR/Cas9 strategy, CAKE, achieving faithful duplex protein labeling using sequential editing of genes. We use CAKE to visualize the co-localization of essential neuronal proteins, including cytoskeleton components, ion channels and synaptic scaffolds. Using super-resolution microscopy, we demonstrate that the co-organization of synaptic scaffolds and neurotransmitter receptors scales with synapse size. Finally, we acutely modulate the dynamics of synaptic receptors using labeling with inducible dimerization domains. Thus, CAKE mediates accurate duplex endogenous protein labeling and manipulation to address biological questions in neurons.
Collapse
Affiliation(s)
- Wouter J Droogers
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Jelmer Willems
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Harold D MacGillavry
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Arthur P H de Jong
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
14
|
Wilson EA, Mao T, Zhong H. Labeling Endogenous Proteins Using CRISPR-mediated Insertion of Exon (CRISPIE). Bio Protoc 2022; 12:e4343. [PMID: 35592602 PMCID: PMC8918219 DOI: 10.21769/bioprotoc.4343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 10/11/2021] [Accepted: 01/13/2022] [Indexed: 12/29/2022] Open
Abstract
The CRISPR/Cas9 technology has transformed our ability to edit eukaryotic genomes. Despite this breakthrough, it remains challenging to precisely knock-in large DNA sequences, such as those encoding a fluorescent protein, for labeling or modifying a target protein in post-mitotic cells. Previous efforts focusing on sequence insertion to the protein coding sequence often suffer from insertions/deletions (INDELs) resulting from the efficient non-homologous end joining pathway (NHEJ). To overcome this limitation, we have developed CRISPR-mediated insertion of exon (CRISPIE). CRISPIE circumvents INDELs and other editing errors by inserting a designer exon flanked by adjacent intron sequences into an appropriate intronic location of the targeted gene. Because INDELs at the insertion junction can be spliced out, "CRISPIEd" genes produce precisely edited mRNA transcripts that are virtually error-free. In part due to the elimination of INDELs, high-efficiency labeling can be achieved in vivo. CRISPIE is compatible with both N- and C-terminal labels, and with all common transfection methods. Importantly, CRISPIE allows for later removal of the protein modification by including exogenous single-guide RNA (sgRNA) sites in the intronic region of the donor module. This protocol provides the detailed CRISPIE methodology, using endogenous labeling of β-actin in human U-2 OS cells with enhanced green fluorescent protein (EGFP) as an example. When combined with the appropriate gene delivery methods, the same methodology can be applied to label post-mitotic neurons in culture and in vivo. This methodology can also be readily adapted for use in other gene editing contexts.
Collapse
Affiliation(s)
- Evan A. Wilson
- Vollum Institute, Oregon Health & Sciences University, Portland, OR, USA
| | - Tianyi Mao
- Vollum Institute, Oregon Health & Sciences University, Portland, OR, USA
| | - Haining Zhong
- Vollum Institute, Oregon Health & Sciences University, Portland, OR, USA,
*For correspondence:
| |
Collapse
|
15
|
Melander JB, Nayebi A, Jongbloets BC, Fortin DA, Qin M, Ganguli S, Mao T, Zhong H. Distinct in vivo dynamics of excitatory synapses onto cortical pyramidal neurons and parvalbumin-positive interneurons. Cell Rep 2021; 37:109972. [PMID: 34758304 PMCID: PMC8631347 DOI: 10.1016/j.celrep.2021.109972] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/03/2021] [Accepted: 10/19/2021] [Indexed: 11/18/2022] Open
Abstract
Cortical function relies on the balanced activation of excitatory and inhibitory neurons. However, little is known about the organization and dynamics of shaft excitatory synapses onto cortical inhibitory interneurons. Here, we use the excitatory postsynaptic marker PSD-95, fluorescently labeled at endogenous levels, as a proxy for excitatory synapses onto layer 2/3 pyramidal neurons and parvalbumin-positive (PV+) interneurons in the barrel cortex of adult mice. Longitudinal in vivo imaging under baseline conditions reveals that, although synaptic weights in both neuronal types are log-normally distributed, synapses onto PV+ neurons are less heterogeneous and more stable. Markov model analyses suggest that the synaptic weight distribution is set intrinsically by ongoing cell-type-specific dynamics, and substantial changes are due to accumulated gradual changes. Synaptic weight dynamics are multiplicative, i.e., changes scale with weights, although PV+ synapses also exhibit an additive component. These results reveal that cell-type-specific processes govern cortical synaptic strengths and dynamics. Melander et al. use a genetic strategy to visualize excitatory neuronal connections that cannot be inferred from morphology, and they monitor how the connections change over weeks in mice. They find distinct characteristics between synapses onto cells that “suppress” brain activity and those onto cells that “excite” brain activity.
Collapse
Affiliation(s)
- Joshua B Melander
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA; Neurosciences PhD Program, Stanford University, Stanford, CA 94305, USA
| | - Aran Nayebi
- Neurosciences PhD Program, Stanford University, Stanford, CA 94305, USA
| | - Bart C Jongbloets
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Dale A Fortin
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Maozhen Qin
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Surya Ganguli
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA.
| | - Tianyi Mao
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Haining Zhong
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA.
| |
Collapse
|
16
|
Levic DS, Yamaguchi N, Wang S, Knaut H, Bagnat M. Knock-in tagging in zebrafish facilitated by insertion into non-coding regions. Development 2021; 148:dev199994. [PMID: 34495314 PMCID: PMC8513609 DOI: 10.1242/dev.199994] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 08/27/2021] [Indexed: 11/20/2022]
Abstract
Zebrafish provide an excellent model for in vivo cell biology studies because of their amenability to live imaging. Protein visualization in zebrafish has traditionally relied on overexpression of fluorescently tagged proteins from heterologous promoters, making it difficult to recapitulate endogenous expression patterns and protein function. One way to circumvent this problem is to tag the proteins by modifying their endogenous genomic loci. Such an approach is not widely available to zebrafish researchers because of inefficient homologous recombination and the error-prone nature of targeted integration in zebrafish. Here, we report a simple approach for tagging proteins in zebrafish on their N or C termini with fluorescent proteins by inserting PCR-generated donor amplicons into non-coding regions of the corresponding genes. Using this approach, we generated endogenously tagged alleles for several genes that are crucial for epithelial biology and organ development, including the tight junction components ZO-1 and Cldn15la, the trafficking effector Rab11a, the apical polarity protein aPKC and the ECM receptor Integrin β1b. Our approach facilitates the generation of knock-in lines in zebrafish, opening the way for accurate quantitative imaging studies.
Collapse
Affiliation(s)
- Daniel S. Levic
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Naoya Yamaguchi
- Skirball Institute of Biomolecular Medicine, New York University Grossman School of Medicine, Department of Cell Biology, New York, NY 10016, USA
| | - Siyao Wang
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Holger Knaut
- Skirball Institute of Biomolecular Medicine, New York University Grossman School of Medicine, Department of Cell Biology, New York, NY 10016, USA
| | - Michel Bagnat
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| |
Collapse
|
17
|
OUP accepted manuscript. Microscopy (Oxf) 2021; 71:i72-i80. [DOI: 10.1093/jmicro/dfab048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/18/2021] [Accepted: 01/24/2022] [Indexed: 11/14/2022] Open
|