1
|
Bartelt LC, Fakhri M, Adamek G, Trybus M, Samelak-Czajka A, Jackowiak P, Fiszer A, Lowe CB, La Spada AR, Switonski PM. Antibody-assisted selective isolation of Purkinje cell nuclei from mouse cerebellar tissue. CELL REPORTS METHODS 2024; 4:100816. [PMID: 38981474 DOI: 10.1016/j.crmeth.2024.100816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/08/2024] [Accepted: 06/17/2024] [Indexed: 07/11/2024]
Abstract
We developed a method that utilizes fluorescent labeling of nuclear envelopes alongside cytometry sorting for the selective isolation of Purkinje cell (PC) nuclei. Beginning with SUN1 reporter mice, we GFP-tagged envelopes to confirm that PC nuclei could be accurately separated from other cell types. We then developed an antibody-based protocol to make PC nuclear isolation more robust and adaptable to cerebellar tissues of any genotypic background. Immunofluorescent labeling of the nuclear membrane protein RanBP2 enabled the isolation of PC nuclei from C57BL/6 cerebellum. By analyzing the expression of PC markers, nuclear size, and nucleoli number, we confirmed that our method delivers a pure fraction of PC nuclei. To demonstrate its applicability, we isolated PC nuclei from spinocerebellar ataxia type 7 (SCA7) mice and identified transcriptional changes in known and new disease-associated genes. Access to pure PC nuclei offers insights into PC biology and pathology, including the nature of selective neuronal vulnerability.
Collapse
Affiliation(s)
- Luke C Bartelt
- University Program in Genetics & Genomics, Duke University Medical Center, Durham, NC 27710, USA; Departments of Pathology & Laboratory Medicine, Neurology, Biological Chemistry, and Neurobiology & Behavior, University of California, Irvine, Irvine, CA 92697, USA; Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Mouad Fakhri
- Department of Neuronal Cell Biology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Grazyna Adamek
- Department of Neuronal Cell Biology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Magdalena Trybus
- Laboratory of Single Cell Analyses, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Anna Samelak-Czajka
- Laboratory of Single Cell Analyses, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Paulina Jackowiak
- Laboratory of Single Cell Analyses, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Agnieszka Fiszer
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Craig B Lowe
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Albert R La Spada
- Departments of Pathology & Laboratory Medicine, Neurology, Biological Chemistry, and Neurobiology & Behavior, University of California, Irvine, Irvine, CA 92697, USA; Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA; UCI Center for Neurotherapeutics, University of California, Irvine, Irvine, CA 92697, USA.
| | - Pawel M Switonski
- Department of Neuronal Cell Biology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland.
| |
Collapse
|
2
|
Hazlett MF, Hall VL, Patel E, Halvorsen A, Calakos N, West AE. The Perineuronal Net Protein Brevican Acts in Nucleus Accumbens Parvalbumin-Expressing Interneurons of Adult Mice to Regulate Excitatory Synaptic Inputs and Motivated Behaviors. Biol Psychiatry 2024:S0006-3223(24)00080-5. [PMID: 38346480 DOI: 10.1016/j.biopsych.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/13/2024] [Accepted: 02/07/2024] [Indexed: 04/09/2024]
Abstract
BACKGROUND Experience-dependent functional adaptation of nucleus accumbens (NAc) circuitry underlies the development and expression of reward-motivated behaviors. Parvalbumin-expressing GABAergic (gamma-aminobutyric acidergic) interneurons (PVINs) within the NAc are required for this process. Perineuronal nets (PNNs) are extracellular matrix structures enriched around PVINs that arise during development and have been proposed to mediate brain circuit stability. However, their function in the adult NAc is largely unknown. Here, we studied the developmental emergence and adult regulation of PNNs in the NAc of male and female mice and examined the cellular and behavioral consequences of reducing the PNN component brevican in NAc PVINs. METHODS We characterized the expression of PNN components in mouse NAc using immunofluorescence and RNA in situ hybridization. We lowered brevican in NAc PVINs of adult mice using an intersectional viral and genetic method and quantified the effects on synaptic inputs to NAc PVINs and reward-motivated learning. RESULTS PNNs around NAc PVINs were developmentally regulated and appeared during adolescence. In the adult NAc, PVIN PNNs were also dynamically regulated by cocaine. Transcription of the gene that encodes brevican was regulated in a cell type- and isoform-specific manner in the NAc, with the membrane-tethered form of brevican being highly enriched in PVINs. Lowering brevican in NAc PVINs of adult mice decreased their excitatory inputs and enhanced both short-term novel object recognition and cocaine-induced conditioned place preference. CONCLUSIONS Regulation of brevican in NAc PVINs of adult mice modulates their excitatory synaptic drive and sets experience thresholds for the development of motivated behaviors driven by rewarding stimuli.
Collapse
Affiliation(s)
- Mariah F Hazlett
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina
| | - Victoria L Hall
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina
| | - Esha Patel
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina
| | - Aaron Halvorsen
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina
| | - Nicole Calakos
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina; Department of Neurology, Duke University Medical Center, Durham, North Carolina; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina; Duke Institute for Brain Sciences, Duke University Medical Center, Durham, North Carolina
| | - Anne E West
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina.
| |
Collapse
|
3
|
Phillips RA, Wan E, Tuscher JJ, Reid D, Drake OR, Ianov L, Day JJ. Temporally specific gene expression and chromatin remodeling programs regulate a conserved Pdyn enhancer. eLife 2023; 12:RP89993. [PMID: 37938195 PMCID: PMC10631760 DOI: 10.7554/elife.89993] [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: 11/09/2023] Open
Abstract
Neuronal and behavioral adaptations to novel stimuli are regulated by temporally dynamic waves of transcriptional activity, which shape neuronal function and guide enduring plasticity. Neuronal activation promotes expression of an immediate early gene (IEG) program comprised primarily of activity-dependent transcription factors, which are thought to regulate a second set of late response genes (LRGs). However, while the mechanisms governing IEG activation have been well studied, the molecular interplay between IEGs and LRGs remain poorly characterized. Here, we used transcriptomic and chromatin accessibility profiling to define activity-driven responses in rat striatal neurons. As expected, neuronal depolarization generated robust changes in gene expression, with early changes (1 hr) enriched for inducible transcription factors and later changes (4 hr) enriched for neuropeptides, synaptic proteins, and ion channels. Remarkably, while depolarization did not induce chromatin remodeling after 1 hr, we found broad increases in chromatin accessibility at thousands of sites in the genome at 4 hr after neuronal stimulation. These putative regulatory elements were found almost exclusively at non-coding regions of the genome, and harbored consensus motifs for numerous activity-dependent transcription factors such as AP-1. Furthermore, blocking protein synthesis prevented activity-dependent chromatin remodeling, suggesting that IEG proteins are required for this process. Targeted analysis of LRG loci identified a putative enhancer upstream of Pdyn (prodynorphin), a gene encoding an opioid neuropeptide implicated in motivated behavior and neuropsychiatric disease states. CRISPR-based functional assays demonstrated that this enhancer is both necessary and sufficient for Pdyn transcription. This regulatory element is also conserved at the human PDYN locus, where its activation is sufficient to drive PDYN transcription in human cells. These results suggest that IEGs participate in chromatin remodeling at enhancers and identify a conserved enhancer that may act as a therapeutic target for brain disorders involving dysregulation of Pdyn.
Collapse
Affiliation(s)
- Robert A Phillips
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Ethan Wan
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Jennifer J Tuscher
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - David Reid
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Olivia R Drake
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Lara Ianov
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
- Civitan International Research Center, University of Alabama at BirminghamBirminghamUnited States
| | - Jeremy J Day
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| |
Collapse
|
4
|
Green MV, Gallegos DA, Boua JV, Bartelt LC, Narayanan A, West AE. Single-Nucleus Transcriptional Profiling of GAD2-Positive Neurons From Mouse Lateral Habenula Reveals Distinct Expression of Neurotransmission- and Depression-Related Genes. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2023; 3:686-697. [PMID: 37881543 PMCID: PMC10593960 DOI: 10.1016/j.bpsgos.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 10/27/2023] Open
Abstract
Background Glutamatergic projection neurons of the lateral habenula (LHb) drive behavioral state modulation by regulating the activity of midbrain monoaminergic neurons. Identifying circuit mechanisms that modulate LHb output is of interest for understanding control of motivated behaviors. Methods A small population of neurons within the medial subnucleus of the mouse LHb express the GABAergic (gamma-aminobutyric acidergic)-synthesizing enzyme GAD2, and they can inhibit nearby LHb projection neurons; however, these neurons lack markers of classic inhibitory interneurons, and they coexpress the vesicular glutamate transporter VGLUT2. To determine the molecular phenotype of these neurons, we genetically tagged the nuclei of GAD2-positive cells and used fluorescence-activated nuclear sorting to isolate and enrich these nuclei for single-nucleus RNA sequencing. Results Our data confirm that GAD2+/VGLUT2+ neurons intrinsic to the LHb coexpress markers of both glutamatergic and GABAergic transmission and that they are transcriptionally distinct from either GABAergic interneurons or habenular glutamatergic neurons. We identify gene expression programs within these cells that show sex-specific differences in expression and that are implicated in major depressive disorder, which has been linked to LHb hyperactivity. Finally, we identify the Ntng2 gene encoding the cell adhesion protein netrin-G2 as a marker of LHb GAD2+/VGLUT2+ neurons and a gene product that may contribute to their target projections. Conclusions These data show the value of using genetic enrichment of rare cell types for transcriptome studies, and they advance understanding of the molecular composition of a functionally important class of GAD2+ neurons in the LHb.
Collapse
Affiliation(s)
- Matthew V. Green
- Department of Neurobiology, Duke University, Durham, North Carolina
| | | | | | - Luke C. Bartelt
- Department of Neurobiology, Duke University, Durham, North Carolina
| | - Arthy Narayanan
- Department of Neurobiology, Duke University, Durham, North Carolina
| | - Anne E. West
- Department of Neurobiology, Duke University, Durham, North Carolina
| |
Collapse
|
5
|
Bhatia P, Yang L, Luo JXJ, Xu M, Renthal W. Epigenomic profiling of mouse nucleus accumbens at single-cell resolution. Mol Cell Neurosci 2023; 126:103857. [PMID: 37137383 PMCID: PMC10525004 DOI: 10.1016/j.mcn.2023.103857] [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: 01/15/2023] [Revised: 04/21/2023] [Accepted: 04/26/2023] [Indexed: 05/05/2023] Open
Abstract
The nucleus accumbens (NAc) is a key brain region involved in reward processing and is linked to multiple neuropsychiatric conditions such as substance use disorder, depression, and chronic pain. Recent studies have begun to investigate NAc gene expression at a single-cell resolution, however, our understanding of the cellular heterogeneity of the NAc epigenomic landscape remains limited. In this study, we utilize single-nucleus assay for transposase-accessible chromatin using sequencing (snATAC-seq) to map cell-type-specific differences in chromatin accessibility in the NAc. Our findings not only reveal the transcription factors and putative gene regulatory elements that may contribute to these cell-type-specific epigenomic differences but also provide a valuable resource for future studies investigating epigenomic changes that occur in neuropsychiatric disorders.
Collapse
Affiliation(s)
- Parth Bhatia
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, USA
| | - Lite Yang
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, USA
| | - Jay X J Luo
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, USA
| | - Mengyi Xu
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, USA
| | - William Renthal
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, USA.
| |
Collapse
|
6
|
Chehimi SN, Crist RC, Reiner BC. Unraveling Psychiatric Disorders through Neural Single-Cell Transcriptomics Approaches. Genes (Basel) 2023; 14:genes14030771. [PMID: 36981041 PMCID: PMC10047992 DOI: 10.3390/genes14030771] [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: 02/18/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
The development of single-cell and single-nucleus transcriptome technologies is enabling the unraveling of the molecular and cellular heterogeneity of psychiatric disorders. The complexity of the brain and the relationships between different brain regions can be better understood through the classification of individual cell populations based on their molecular markers and transcriptomic features. Analysis of these unique cell types can explain their involvement in the pathology of psychiatric disorders. Recent studies in both human and animal models have emphasized the importance of transcriptome analysis of neuronal cells in psychiatric disorders but also revealed critical roles for non-neuronal cells, such as oligodendrocytes and microglia. In this review, we update current findings on the brain transcriptome and explore molecular studies addressing transcriptomic alterations identified in human and animal models in depression and stress, neurodegenerative disorders (Parkinson's and Alzheimer's disease), schizophrenia, opioid use disorder, and alcohol and psychostimulant abuse. We also comment on potential future directions in single-cell and single-nucleus studies.
Collapse
Affiliation(s)
- Samar N Chehimi
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Richard C Crist
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Benjamin C Reiner
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
7
|
Green MV, Gallegos DA, Boua JV, Bartelt LC, Narayanan A, West AE. Single-nucleus transcriptional profiling of GAD2-positive neurons from mouse lateral habenula reveals distinct expression of neurotransmission- and depression-related genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.09.523312. [PMID: 36711842 PMCID: PMC9882053 DOI: 10.1101/2023.01.09.523312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Glutamatergic projection neurons of the lateral habenula (LHb) drive behavioral state modulation by regulating the activity of midbrain monoaminergic neurons. Identifying circuit mechanisms that modulate LHb output is of interest for understanding control of motivated behaviors. A small population of neurons within the medial subnucleus of the mouse LHb express the GABAergic synthesizing enzyme GAD2, and they can inhibit nearby LHb projection neurons; however, these neurons lack markers of classic inhibitory interneurons and they co-express the vesicular glutamate transporter VGLUT2. To determine the molecular phenotype of these neurons, we genetically tagged the nuclei of GAD2-positive cells and used fluorescence-activated nuclear sorting to isolate and enrich these nuclei for single nuclear RNA sequencing (FANS-snRNAseq). Our data confirm that GAD2+/VGLUT2+ neurons intrinsic to the LHb co-express markers of both glutamatergic and GABAergic transmission and that they are transcriptionally distinct from either GABAergic interneurons or habenular glutamatergic neurons. We identify gene expression programs within these cells that show sex-specific differences in expression and that are implicated in major depressive disorder (MDD), which has been linked to LHb hyperactivity. Finally, we identify the Ntng2 gene encoding the cell adhesion protein Netrin-G2 as a marker of LHb GAD2+/VGLUT+ neurons and a gene product that may contribute to their target projections. These data show the value of using genetic enrichment of rare cell types for transcriptome studies, and they advance understanding of the molecular composition of a functionally important class of GAD2+ neurons in the LHb.
Collapse
Affiliation(s)
- Matthew V Green
- Department of Neurobiology, Duke University, Durham NC 27710
| | | | | | - Luke C Bartelt
- Department of Neurobiology, Duke University, Durham NC 27710
| | - Arthy Narayanan
- Department of Neurobiology, Duke University, Durham NC 27710
| | - Anne E West
- Department of Neurobiology, Duke University, Durham NC 27710
| |
Collapse
|