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Kremp M, Aberle T, Sock E, Bohl B, Hillgärtner S, Winkler J, Wegner M. Transcription factor Olig2 is a major downstream effector of histone demethylase Phf8 during oligodendroglial development. Glia 2024; 72:1435-1450. [PMID: 38613395 DOI: 10.1002/glia.24538] [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: 02/14/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/14/2024]
Abstract
The plant homeodomain finger protein Phf8 is a histone demethylase implicated by mutation in mice and humans in neural crest defects and neurodevelopmental disturbances. Considering its widespread expression in cell types of the central nervous system, we set out to determine the role of Phf8 in oligodendroglial cells to clarify whether oligodendroglial defects are a possible contributing factor to Phf8-dependent neurodevelopmental disorders. Using loss- and gain-of-function approaches in oligodendroglial cell lines and primary cell cultures, we show that Phf8 promotes the proliferation of rodent oligodendrocyte progenitor cells and impairs their differentiation to oligodendrocytes. Intriguingly, Phf8 has a strong positive impact on Olig2 expression by acting on several regulatory regions of the gene and changing their histone modification profile. Taking the influence of Olig2 levels on oligodendroglial proliferation and differentiation into account, Olig2 likely acts as an important downstream effector of Phf8 in these cells. In line with such an effector function, ectopic Olig2 expression in Phf8-deficient cells rescues the proliferation defect. Additionally, generation of human oligodendrocytes from induced pluripotent stem cells did not require PHF8 in a system that relies on forced expression of Olig2 during oligodendroglial induction. We conclude that Phf8 may impact nervous system development at least in part through its action in oligodendroglial cells.
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Affiliation(s)
- Marco Kremp
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Tim Aberle
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Elisabeth Sock
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Bettina Bohl
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Simone Hillgärtner
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jürgen Winkler
- Abteilung für Molekulare Neurologie, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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2
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Schmidt AL, Kremp M, Aratake T, Cui S, Lin Y, Zhong X, Lu QR, Zhang C, Qiu M, Aberle T, Wegner M. The myelination-associated G protein-coupled receptor 37 is regulated by Zfp488, Nkx2.2, and Sox10 during oligodendrocyte differentiation. Glia 2024; 72:1304-1318. [PMID: 38546197 DOI: 10.1002/glia.24530] [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: 10/12/2023] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 05/12/2024]
Abstract
Oligodendrocyte differentiation and myelination in the central nervous system are controlled and coordinated by a complex gene regulatory network that contains several transcription factors, including Zfp488 and Nkx2.2. Despite the proven role in oligodendrocyte differentiation little is known about the exact mode of Zfp488 and Nkx2.2 action, including their target genes. Here, we used overexpression of Zfp488 and Nkx2.2 in differentiating CG4 cells to identify aspects of the oligodendroglial expression profile that depend on these transcription factors. Although both transcription factors are primarily described as repressors, the detected changes argue for an additional function as activators. Among the genes activated by both Zfp488 and Nkx2.2 was the G protein-coupled receptor Gpr37 that is important during myelination. In agreement with a positive effect on Gpr37 expression, downregulation of the G protein-coupled receptor was observed in Zfp488- and in Nkx2.2-deficient oligodendrocytes in the mouse. We also identified several potential regulatory regions of the Gpr37 gene. Although Zfp488 and Nkx2.2 both bind to one of the regulatory regions downstream of the Gpr37 gene in vivo, none of the regulatory regions was activated by either transcription factor alone. Increased activation by Zfp488 or Nkx2.2 was only observed in the presence of Sox10, a transcription factor continuously present in oligodendroglial cells. Our results argue that both Zfp488 and Nkx2.2 also act as transcriptional activators during oligodendrocyte differentiation and cooperate with Sox10 to allow the expression of Gpr37 as a modulator of the myelination process.
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Affiliation(s)
- Antonia L Schmidt
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Marco Kremp
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Takaaki Aratake
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Siying Cui
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yifeng Lin
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xiaowen Zhong
- Brain Tumor Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio, USA
| | - Q Richard Lu
- Brain Tumor Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio, USA
| | - Chengfu Zhang
- College of Life Sciences, Zhejiang University, Hangzhou, China
- Institute of Life Sciences, Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou Normal University, Hangzhou, China
| | - Mengsheng Qiu
- College of Life Sciences, Zhejiang University, Hangzhou, China
- Institute of Life Sciences, Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou Normal University, Hangzhou, China
| | - Tim Aberle
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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Emery B, Wood TL. Regulators of Oligodendrocyte Differentiation. Cold Spring Harb Perspect Biol 2024; 16:a041358. [PMID: 38503504 PMCID: PMC11146316 DOI: 10.1101/cshperspect.a041358] [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] [Indexed: 03/21/2024]
Abstract
Myelination has evolved as a mechanism to ensure fast and efficient propagation of nerve impulses along axons. Within the central nervous system (CNS), myelination is carried out by highly specialized glial cells, oligodendrocytes. The formation of myelin is a prolonged aspect of CNS development that occurs well into adulthood in humans, continuing throughout life in response to injury or as a component of neuroplasticity. The timing of myelination is tightly tied to the generation of oligodendrocytes through the differentiation of their committed progenitors, oligodendrocyte precursor cells (OPCs), which reside throughout the developing and adult CNS. In this article, we summarize our current understanding of some of the signals and pathways that regulate the differentiation of OPCs, and thus the myelination of CNS axons.
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Affiliation(s)
- Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Teresa L Wood
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, USA
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Elitt CM, Ross MM, Wang J, Fahrni CJ, Rosenberg PA. Developmental regulation of zinc homeostasis in differentiating oligodendrocytes. Neurosci Lett 2024; 831:137727. [PMID: 38467270 DOI: 10.1016/j.neulet.2024.137727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 03/05/2024] [Accepted: 03/08/2024] [Indexed: 03/13/2024]
Abstract
Oligodendrocytes develop through sequential stages and understanding pathways regulating their differentiation remains an important area of investigation. Zinc is required for the function of enzymes, proteins and transcription factors, including those important in myelination and mitosis. Our previous studies using the ratiometric zinc sensor chromis-1 demonstrated a reduction in intracellular free zinc concentrations in mature MBP+ oligodendrocytes compared with earlier stages (Bourassa et al., 2018). We performed a more detailed developmental study to better understand the temporal course of zinc homeostasis across the oligodendrocyte lineage. Using chromis-1, we found a transient increase in free zinc after O4+,O1- pre-oligodendrocytes were switched from proliferation medium into terminal differentiation medium. To gather other evidence for dynamic regulation of free zinc during oligodendrocyte development, qPCR was used to evaluate mRNA expression of major zinc storage proteins metallothioneins (MTs) and metal regulatory transcription factor 1 (MTF1), which controls expression of MTs. MT1, MT2 and MTF1 mRNAs were increased several fold in mature oligodendrocytes compared to oligodendrocytes in proliferation medium. To assess the depth of the zinc buffer, we assayed zinc release from intracellular stores using the oxidizing thiol reagent 2,2'-dithiodipyridine (DTDP). Exposure to DTDP resulted in ∼ 100% increase in free zinc in pre-oligodendrocytes but, paradoxically more modest ∼ 60% increase in mature oligodendrocytes despite increased expression of MTs. These results suggest that zinc homeostasis is regulated during oligodendrocyte development, that oligodendrocytes are a useful model for studying zinc homeostasis in the central nervous system, and that regulation of zinc homeostasis may be important in oligodendrocyte differentiation.
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Affiliation(s)
- Christopher M Elitt
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, United States; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, United States.
| | - Madeline M Ross
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, United States; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, United States
| | - Jianlin Wang
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, United States; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, United States
| | - Christoph J Fahrni
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, United States; Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - Paul A Rosenberg
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, United States; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, United States
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Aberle T, Walter A, Piefke S, Hillgärtner S, Wüst HM, Wegner M, Küspert M. Sox10 Activity and the Timing of Schwann Cell Differentiation Are Controlled by a Tle4-Dependent Negative Feedback Loop. Int J Mol Sci 2024; 25:5234. [PMID: 38791273 PMCID: PMC11120983 DOI: 10.3390/ijms25105234] [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: 04/17/2024] [Revised: 05/08/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
The HMG-domain containing transcription factor Sox10 plays a crucial role in regulating Schwann cell survival and differentiation and is expressed throughout the entire Schwann cell lineage. While its importance in peripheral myelination is well established, little is known about its role in the early stages of Schwann cell development. In a search for direct target genes of Sox10 in Schwann cell precursors, the transcriptional co-repressor Tle4 was identified. At least two regions upstream of the Tle4 gene appear involved in mediating the Sox10-dependent activation. Once induced, Tle4 works in tandem with the bHLH transcriptional repressor Hes1 and exerts a dual inhibitory effect on Sox10 by preventing the Sox10 protein from transcriptionally activating maturation genes and by suppressing Sox10 expression through known enhancers of the gene. This mechanism establishes a regulatory barrier that prevents premature activation of factors involved in differentiation and myelin formation by Sox10 in immature Schwann cells. The identification of Tle4 as a critical downstream target of Sox10 sheds light on the gene regulatory network in the early phases of Schwann cell development. It unravels an elaborate regulatory circuitry that fine-tunes the timing and extent of Schwann cell differentiation and myelin gene expression.
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Affiliation(s)
| | | | | | | | | | | | - Melanie Küspert
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Fahrstrasse 17, 91054 Erlangen, Germany; (T.A.)
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Lu Z, Zhang M, Lee J, Sziraki A, Anderson S, Zhang Z, Xu Z, Jiang W, Ge S, Nelson PT, Zhou W, Cao J. Tracking cell-type-specific temporal dynamics in human and mouse brains. Cell 2023; 186:4345-4364.e24. [PMID: 37774676 PMCID: PMC10545416 DOI: 10.1016/j.cell.2023.08.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 05/28/2023] [Accepted: 08/30/2023] [Indexed: 10/01/2023]
Abstract
Progenitor cells are critical in preserving organismal homeostasis, yet their diversity and dynamics in the aged brain remain underexplored. We introduced TrackerSci, a single-cell genomic method that combines newborn cell labeling and combinatorial indexing to characterize the transcriptome and chromatin landscape of proliferating progenitor cells in vivo. Using TrackerSci, we investigated the dynamics of newborn cells in mouse brains across various ages and in a mouse model of Alzheimer's disease. Our dataset revealed diverse progenitor cell types in the brain and their epigenetic signatures. We further quantified aging-associated shifts in cell-type-specific proliferation and differentiation and deciphered the associated molecular programs. Extending our study to the progenitor cells in the aged human brain, we identified conserved genetic signatures across species and pinpointed region-specific cellular dynamics, such as the reduced oligodendrogenesis in the cerebellum. We anticipate that TrackerSci will be broadly applicable to unveil cell-type-specific temporal dynamics in diverse systems.
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Affiliation(s)
- Ziyu Lu
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA; The David Rockefeller Graduate Program in Bioscience, The Rockefeller University, New York, NY, USA
| | - Melissa Zhang
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA
| | - Jasper Lee
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA
| | - Andras Sziraki
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA; The David Rockefeller Graduate Program in Bioscience, The Rockefeller University, New York, NY, USA
| | - Sonya Anderson
- Department of Pathology and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Zehao Zhang
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA; The David Rockefeller Graduate Program in Bioscience, The Rockefeller University, New York, NY, USA
| | - Zihan Xu
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA; The David Rockefeller Graduate Program in Bioscience, The Rockefeller University, New York, NY, USA
| | - Weirong Jiang
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA
| | - Shaoyu Ge
- Department of Neurobiology & Behavior, SUNY at Stony Brook, Stony Brook, NY, USA
| | - Peter T Nelson
- Department of Pathology and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Wei Zhou
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA.
| | - Junyue Cao
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA.
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Elitt CM, Ross MM, Wang J, Fahrni CJ, Rosenberg PA. Developmental regulation of zinc homeostasis in differentiating oligodendrocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.26.550230. [PMID: 37546881 PMCID: PMC10402100 DOI: 10.1101/2023.07.26.550230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Oligodendrocytes develop through well characterized stages and understanding pathways regulating their differentiation remains an active area of investigation. Zinc is required for the function of many enzymes, proteins and transcription factors, including those important in myelination and mitosis. Our previous studies using the ratiometric zinc sensor chromis-1 demonstrated a reduction in intracellular free zinc concentrations in mature oligodendrocytes compared with earlier stages (Bourassa et al., 2018). We performed a more detailed developmental study to better understand the temporal course of zinc homeostasis across the oligodendrocyte lineage. Using chromis-1, we found a transient increase in free zinc after developing oligodendrocytes were switched into differentiation medium. To gather other evidence for dynamic regulation of free zinc during oligodendrocyte development, qPCR was used to evaluate mRNA expression of the major zinc storage proteins metallothioneins (MTs), and metal regulatory transcription factor 1 (MTF-1) which controls expression of MTs. MT-1, MT-2 and MTF1 mRNAs were all increased several fold in mature oligodendrocytes compared to developing oligodendrocytes. To assess the depth of the zinc buffer, we assayed zinc release from intracellular stores using the oxidizing thiol reagent 2,2'-dithiodipyridine (DTDP). Exposure to DTDP resulted in a ∼100% increase in free zinc in developing oligodendrocytes but, paradoxically more modest ∼60% increase in mature oligodendrocytes despite the increased expression of MTs. These results suggest that zinc homeostasis is regulated during oligodendrocyte development, that oligodendrocytes are a useful model for studying zinc homeostasis in the central nervous system, and that regulation of zinc homeostasis may be important in oligodendrocyte differentiation.
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