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Tsimpos P, Desiderio S, Cabochette P, Poelvoorde P, Kricha S, Vanhamme L, Poulard C, Bellefroid EJ. Loss of G9a does not phenocopy the requirement for Prdm12 in the development of the nociceptive neuron lineage. Neural Dev 2024; 19:1. [PMID: 38167468 PMCID: PMC10759634 DOI: 10.1186/s13064-023-00179-7] [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: 09/25/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024] Open
Abstract
Prdm12 is an epigenetic regulator expressed in developing and mature nociceptive neurons, playing a key role in their specification during neurogenesis and modulating pain sensation at adulthood. In vitro studies suggested that Prdm12 recruits the methyltransferase G9a through its zinc finger domains to regulate target gene expression, but how Prdm12 interacts with G9a and whether G9a plays a role in Prdm12's functional properties in sensory ganglia remain unknown. Here we report that Prdm12-G9a interaction is likely direct and that it involves the SET domain of G9a. We show that both proteins are largely co-expressed in dorsal root ganglia during early murine development, opening the possibility that G9a plays a role in DRG and may act as a mediator of Prdm12's function in the development of nociceptive sensory neurons. To test this hypothesis, we conditionally inactivated G9a in neural crest using a Wnt1-Cre transgenic mouse line. We found that the specific loss of G9a in the neural crest lineage does not lead to dorsal root ganglia hypoplasia due to the loss of somatic nociceptive neurons nor to the ectopic expression of the visceral determinant Phox2b as observed upon Prdm12 ablation. These findings suggest that Prdm12 function in the initiation of the nociceptive lineage does not critically involves its interaction with G9a.
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Affiliation(s)
- Panagiotis Tsimpos
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, B- 6041, Belgium
| | - Simon Desiderio
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, B- 6041, Belgium
| | - Pauline Cabochette
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, B- 6041, Belgium
| | - Philippe Poelvoorde
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Sadia Kricha
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, B- 6041, Belgium
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Coralie Poulard
- Cancer Research Cancer of Lyon, Université de Lyon, Lyon, F-69000, France
- Inserm U1052, Centre de Recherche en Cancérologie de Lyon, Lyon, F-69000, France
- CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, Lyon, F-69000, France
| | - Eric J Bellefroid
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, B- 6041, Belgium.
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D'Elia KP, Hameedy H, Goldblatt D, Frazel P, Kriese M, Zhu Y, Hamling KR, Kawakami K, Liddelow SA, Schoppik D, Dasen JS. Determinants of motor neuron functional subtypes important for locomotor speed. Cell Rep 2023; 42:113049. [PMID: 37676768 PMCID: PMC10600875 DOI: 10.1016/j.celrep.2023.113049] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/12/2023] [Accepted: 08/11/2023] [Indexed: 09/09/2023] Open
Abstract
Locomotion requires precise control of the strength and speed of muscle contraction and is achieved by recruiting functionally distinct subtypes of motor neurons (MNs). MNs are essential to movement and differentially susceptible in disease, but little is known about how MNs acquire functional subtype-specific features during development. Using single-cell RNA profiling in embryonic and larval zebrafish, we identify novel and conserved molecular signatures for MN functional subtypes and identify genes expressed in both early post-mitotic and mature MNs. Assessing MN development in genetic mutants, we define a molecular program essential for MN functional subtype specification. Two evolutionarily conserved transcription factors, Prdm16 and Mecom, are both functional subtype-specific determinants integral for fast MN development. Loss of prdm16 or mecom causes fast MNs to develop transcriptional profiles and innervation similar to slow MNs. These results reveal the molecular diversity of vertebrate axial MNs and demonstrate that functional subtypes are specified through intrinsic transcriptional codes.
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Affiliation(s)
- Kristen P D'Elia
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Hanna Hameedy
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Dena Goldblatt
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA; Center for Neural Science, New York University, New York, NY, USA
| | - Paul Frazel
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - Mercer Kriese
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Yunlu Zhu
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kyla R Hamling
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Koichi Kawakami
- Laboratory of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan
| | - Shane A Liddelow
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - David Schoppik
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA.
| | - Jeremy S Dasen
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA.
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Decourtye L, McCallum-Loudeac JA, Zellhuber-McMillan S, Young E, Sircombe KJ, Wilson MJ. Characterization of a novel Lbx1 mouse loss of function strain. Differentiation 2021; 123:30-41. [PMID: 34906895 DOI: 10.1016/j.diff.2021.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/01/2021] [Accepted: 12/06/2021] [Indexed: 12/13/2022]
Abstract
Adolescent Idiopathic Scoliosis (AIS) is the most common type of spine deformity affecting 2-3% of the population worldwide. The etiology of this disease is still poorly understood. Several GWAS studies have identified single nucleotide polymorphisms (SNPs) located near the gene LBX1 that is significantly correlated with AIS risk. LBX1 is a transcription factor with roles in myocyte precursor migration, cardiac neural crest specification, and neuronal fate determination in the neural tube. Here, we further investigated the role of LBX1 in the developing spinal cord of mouse embryos using a CRISPR-generated mouse model expressing a truncated version of LBX1 (Lbx1Δ). Homozygous mice died at birth, likely due to cardiac abnormalities. To further study the neural tube phenotype, we used RNA-sequencing to identify 410 genes differentially expressed between the neural tubes of E12.5 wildtype and Lbx1Δ/Δ embryos. Genes with increased expression in the deletion line were involved in neurogenesis and those with broad roles in embryonic development. Many of these genes have also been associated with scoliotic phenotypes. In comparison, genes with decreased expression were primarily involved in skeletal development. Subsequent skeletal and immunohistochemistry analysis further confirmed these results. This study aids in understanding the significance of links between LBX1 function and AIS susceptibility.
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Affiliation(s)
- Lyvianne Decourtye
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 9054, Dunedin, New Zealand
| | - Jeremy A McCallum-Loudeac
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 9054, Dunedin, New Zealand
| | - Sylvia Zellhuber-McMillan
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 9054, Dunedin, New Zealand
| | - Emma Young
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 9054, Dunedin, New Zealand
| | - Kathleen J Sircombe
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 9054, Dunedin, New Zealand
| | - Megan J Wilson
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 9054, Dunedin, New Zealand.
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Rienzo M, Di Zazzo E, Casamassimi A, Gazzerro P, Perini G, Bifulco M, Abbondanza C. PRDM12 in Health and Diseases. Int J Mol Sci 2021; 22:ijms222112030. [PMID: 34769459 PMCID: PMC8585061 DOI: 10.3390/ijms222112030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 11/18/2022] Open
Abstract
PRDM12 is a member of the PRDI-BF1 (positive regulatory domain I-binding factor 1) homologous domain (PRDM)-containing protein family, a subfamily of Kruppel-like zinc finger proteins, controlling key processes in the development of cancer. PRDM12 is expressed in a spatio-temporal manner in neuronal systems where it exerts multiple functions. PRDM12 is essential for the neurogenesis initiation and activation of a cascade of downstream pro-neuronal transcription factors in the nociceptive lineage. PRDM12 inactivation, indeed, results in a complete absence of the nociceptive lineage, which is essential for pain perception. Additionally, PRDM12 contributes to the early establishment of anorexigenic neuron identity and the maintenance of high expression levels of pro-opiomelanocortin, which impacts on the program bodyweight homeostasis. PRDMs are commonly involved in cancer, where they act as oncogenes/tumor suppressors in a “Yin and Yang” manner. PRDM12 is not usually expressed in adult normal tissues but its expression is re-activated in several cancer types. However, little information is currently available on PRDM12 expression in cancers and its mechanism of action has not been thoroughly described. In this review, we summarize the recent findings regarding PRDM12 by focusing on four main biological processes: neurogenesis, pain perception, oncogenesis and cell metabolism. Moreover, we wish to highlight the importance of future studies focusing on the PRDM12 signaling pathway(s) and its role in cancer onset and progression.
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Affiliation(s)
- Monica Rienzo
- Department of Environmental, Biological, and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, 81100 Caserta, Italy;
| | - Erika Di Zazzo
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy;
| | - Amelia Casamassimi
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Via L. De Crecchio, 80138 Naples, Italy;
- Correspondence:
| | - Patrizia Gazzerro
- Department of Pharmacy, University of Salerno, 84084 Fisciano, Salerno, Italy;
| | - Giovanni Perini
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy;
| | - Maurizio Bifulco
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, 80131 Naples, Italy;
| | - Ciro Abbondanza
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Via L. De Crecchio, 80138 Naples, Italy;
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Meserve JH, Nelson JC, Marsden KC, Hsu J, Echeverry FA, Jain RA, Wolman MA, Pereda AE, Granato M. A forward genetic screen identifies Dolk as a regulator of startle magnitude through the potassium channel subunit Kv1.1. PLoS Genet 2021; 17:e1008943. [PMID: 34061829 PMCID: PMC8195410 DOI: 10.1371/journal.pgen.1008943] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 06/11/2021] [Accepted: 05/04/2021] [Indexed: 11/19/2022] Open
Abstract
The acoustic startle response is an evolutionarily conserved avoidance behavior. Disruptions in startle behavior, particularly startle magnitude, are a hallmark of several human neurological disorders. While the neural circuitry underlying startle behavior has been studied extensively, the repertoire of genes and genetic pathways that regulate this locomotor behavior has not been explored using an unbiased genetic approach. To identify such genes, we took advantage of the stereotypic startle behavior in zebrafish larvae and performed a forward genetic screen coupled with whole genome analysis. We uncovered mutations in eight genes critical for startle behavior, including two genes encoding proteins associated with human neurological disorders, Dolichol kinase (Dolk), a broadly expressed regulator of the glycoprotein biosynthesis pathway, and the potassium Shaker-like channel subunit Kv1.1. We demonstrate that Kv1.1 and Dolk play critical roles in the spinal cord to regulate movement magnitude during the startle response and spontaneous swim movements. Moreover, we show that Kv1.1 protein is mislocalized in dolk mutants, suggesting they act in a common genetic pathway. Combined, our results identify a diverse set of eight genes, all associated with human disorders, that regulate zebrafish startle behavior and reveal a previously unappreciated role for Dolk and Kv1.1 in regulating movement magnitude via a common genetic pathway.
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Affiliation(s)
- Joy H. Meserve
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jessica C. Nelson
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kurt C. Marsden
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jerry Hsu
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Fabio A. Echeverry
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Roshan A. Jain
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Marc A. Wolman
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alberto E. Pereda
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Michael Granato
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Scott K, O'Rourke R, Gillen A, Appel B. Prdm8 regulates pMN progenitor specification for motor neuron and oligodendrocyte fates by modulating the Shh signaling response. Development 2020; 147:dev.191023. [PMID: 32680935 DOI: 10.1242/dev.191023] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022]
Abstract
Spinal cord pMN progenitors sequentially produce motor neurons and oligodendrocyte precursor cells (OPCs). Some OPCs differentiate rapidly as myelinating oligodendrocytes, whereas others remain into adulthood. How pMN progenitors switch from producing motor neurons to OPCs with distinct fates is poorly understood. pMN progenitors express prdm8, which encodes a transcriptional repressor, during motor neuron and OPC formation. To determine whether prdm8 controls pMN cell fate specification, we used zebrafish as a model system to investigate prdm8 function. Our analysis revealed that prdm8 mutant embryos have fewer motor neurons resulting from a premature switch from motor neuron to OPC production. Additionally, prdm8 mutant larvae have excess oligodendrocytes and a concomitant deficit of OPCs. Notably, pMN cells of mutant embryos have elevated Shh signaling, coincident with the motor neuron to OPC switch. Inhibition of Shh signaling restored the number of motor neurons to normal but did not rescue the proportion of oligodendrocytes. These data suggest that Prdm8 regulates the motor neuron-OPC switch by controlling the level of Shh activity in pMN progenitors, and also regulates the allocation of oligodendrocyte lineage cell fates.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Kayt Scott
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado 40045, USA
| | - Rebecca O'Rourke
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado 40045, USA
| | - Austin Gillen
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 40045, USA.,Division of Hematology, University of Colorado School of Medicine, Aurora, Colorado 40045, USA
| | - Bruce Appel
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado 40045, USA
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Yildiz O, Downes GB, Sagerström CG. Zebrafish prdm12b acts independently of nkx6.1 repression to promote eng1b expression in the neural tube p1 domain. Neural Dev 2019; 14:5. [PMID: 30813944 PMCID: PMC6391800 DOI: 10.1186/s13064-019-0129-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 02/14/2019] [Indexed: 12/12/2022] Open
Abstract
Background Functioning of the adult nervous system depends on the establishment of neural circuits during embryogenesis. In vertebrates, neurons that make up motor circuits form in distinct domains along the dorsoventral axis of the neural tube. Each domain is characterized by a unique combination of transcription factors (TFs) that promote a specific fate, while repressing fates of adjacent domains. The prdm12 TF is required for the expression of eng1b and the generation of V1 interneurons in the p1 domain, but the details of its function remain unclear. Methods We used CRISPR/Cas9 to generate the first germline mutants for prdm12 and employed this resource, together with classical luciferase reporter assays and co-immunoprecipitation experiments, to study prdm12b function in zebrafish. We also generated germline mutants for bhlhe22 and nkx6.1 to examine how these TFs act with prdm12b to control p1 formation. Results We find that prdm12b mutants lack eng1b expression in the p1 domain and also possess an abnormal touch-evoked escape response. Using luciferase reporter assays, we demonstrate that Prdm12b acts as a transcriptional repressor. We also show that the Bhlhe22 TF binds via the Prdm12b zinc finger domain to form a complex. However, bhlhe22 mutants display normal eng1b expression in the p1 domain. While prdm12 has been proposed to promote p1 fates by repressing expression of the nkx6.1 TF, we do not observe an expansion of the nkx6.1 domain upon loss of prdm12b function, nor is eng1b expression restored upon simultaneous loss of prdm12b and nkx6.1. Conclusions We conclude that prdm12b germline mutations produce a phenotype that is indistinguishable from that of morpholino-mediated loss of prdm12 function. In terms of prdm12b function, our results indicate that Prdm12b acts as transcriptional repressor and interacts with both EHMT2/G9a and Bhlhe22. However, bhlhe22 function is not required for eng1b expression in vivo, perhaps indicating that other bhlh genes can compensate during embryogenesis. Lastly, we do not find evidence for nkx6.1 and prdm12b acting as a repressive pair in formation of the p1 domain – suggesting that prdm12b is not solely required to repress non-p1 fates, but is specifically needed to promote p1 fates. Electronic supplementary material The online version of this article (10.1186/s13064-019-0129-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ozge Yildiz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, 364 Plantation St/LRB815, Worcester, MA, 01605, USA
| | - Gerald B Downes
- Department of Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Charles G Sagerström
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, 364 Plantation St/LRB815, Worcester, MA, 01605, USA.
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Rolev K, O'Donovan DG, Georgiou C, Rajan MS, Chittka A. Identification of Prdm genes in human corneal endothelium. Exp Eye Res 2017; 159:114-122. [PMID: 28228349 PMCID: PMC5451076 DOI: 10.1016/j.exer.2017.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 02/01/2017] [Accepted: 02/16/2017] [Indexed: 12/12/2022]
Abstract
Corneal endothelial cells (CECs) are essential for maintaining corneal stromal hydration and ensuring its transparency, which is necessary for normal vision. Dysfunction of CECs leads to stromal decompensation, loss of transparency and corneal blindness. Corneal endothelium has low proliferative potential compared to surface epithelial cells leading to poor regeneration of CEC following injury. Additionally, the tissue exhibits age related decline in endothelial cell density with re-organisation of the cell layer, but no regeneration. The mechanisms which control proliferation and differentiation of neural crest derived CEC progenitors are yet to be clearly elucidated. Prdm (Positive regulatory domain) family of transcriptional regulators and chromatin modifiers are important for driving differentiation of a variety of cellular types. Many Prdm proteins are expressed in specific precursor cell populations and are necessary for their progression to a fully differentiated phenotype. In the present work, we sought to identify members of the Prdm gene family which are specifically expressed in human (h) CECs with a view to begin addressing their potential roles in CEC biology, focussing especially on Prdm 4 and 5 genes. By performing semi-quantitative reverse transcription coupled to PCR amplification we found that in addition to Prdm4 and Prdm5, Prdm2 and Prdm10 genes are expressed in hCECs. We further found that cultured primary hCECs or immortalised HCEC-12 cells express all of the Prdm genes found in CECs, but also express additional Prdm transcripts. This difference is most pronounced between Prdm gene expression patterns of CECs isolated from healthy human corneas and immortalised HCEC-12 cells. We further investigated Prdm 4 and Prdm 5 protein expression in cultured primary hCECs and HCEC-12 cells as well as in a human cadaveric whole cornea. Both Prdm 4 and Prdm 5 are expressed in human corneal endothelium, primary hCECs and in HCECs-12 cells, characterised by expression of the Na+/K+-ATPase. We observed that both proteins exhibit cytosolic (intracellular, but non-nuclear and distinct from extracellular fluid) as well as nuclear localisation within the endothelial layer, with Prdm 5 being more concentrated in the nuclei of the endothelial cells than Prdm 4. Thus, our work identifies novel Prdm genes specifically expressed in corneal endothelial cells which may be important in the control of CEC differentiation and proliferation.
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Affiliation(s)
- Kostadin Rolev
- Anglia Ruskin University, Department of Biomedical and Forensic Sciences and the Vision & Eye Research Unit, Cambridge CB1 1PT, United Kingdom.
| | - Dominic G O'Donovan
- Dept. of Histopathology, Cambridge University Hospitals, Hills Road, Cambridge, Cambridgeshire CB2 0QQ, United Kingdom.
| | - Christiana Georgiou
- The Wolfson Institute for Biomedical Research, Division of Medicine, UCL, Gower St, London WC1E 6BT, United Kingdom.
| | - Madhavan S Rajan
- Anglia Ruskin University, Department of Biomedical and Forensic Sciences and the Vision & Eye Research Unit, Cambridge CB1 1PT, United Kingdom; Department of Ophthalmology, Cambridge University Hospitals, Hills Road, Cambridge, Cambridgeshire CB2 0QQ, United Kingdom.
| | - Alexandra Chittka
- The Wolfson Institute for Biomedical Research, Division of Medicine, UCL, Gower St, London WC1E 6BT, United Kingdom.
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Gunnar E, Bivik C, Starkenberg A, Thor S. sequoia controls the type I>0 daughter proliferation switch in the developing Drosophila nervous system. Development 2016; 143:3774-3784. [PMID: 27578794 DOI: 10.1242/dev.139998] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/22/2016] [Indexed: 01/16/2023]
Abstract
Neural progenitors typically divide asymmetrically to renew themselves, while producing daughters with more limited potential. In the Drosophila embryonic ventral nerve cord, neuroblasts initially produce daughters that divide once to generate two neurons/glia (type I proliferation mode). Subsequently, many neuroblasts switch to generating daughters that differentiate directly (type 0). This programmed type I>0 switch is controlled by Notch signaling, triggered at a distinct point of lineage progression in each neuroblast. However, how Notch signaling onset is gated was unclear. We recently identified Sequoia (Seq), a C2H2 zinc-finger transcription factor with homology to Drosophila Tramtrack (Ttk) and the positive regulatory domain (PRDM) family, as important for lineage progression. Here, we find that seq mutants fail to execute the type I>0 daughter proliferation switch and also display increased neuroblast proliferation. Genetic interaction studies reveal that seq interacts with the Notch pathway, and seq furthermore affects expression of a Notch pathway reporter. These findings suggest that seq may act as a context-dependent regulator of Notch signaling, and underscore the growing connection between Seq, Ttk, the PRDM family and Notch signaling.
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Affiliation(s)
- Erika Gunnar
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping SE-58185, Sweden
| | - Caroline Bivik
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping SE-58185, Sweden
| | - Annika Starkenberg
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping SE-58185, Sweden
| | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping SE-58185, Sweden
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Tunbak H, Georgiou C, Guan C, Richardson WD, Chittka A. Zinc fingers 1, 2, 5 and 6 of transcriptional regulator, PRDM4, are required for its nuclear localisation. Biochem Biophys Res Commun 2016; 474:388-394. [PMID: 27125459 DOI: 10.1016/j.bbrc.2016.04.128] [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: 04/11/2016] [Accepted: 04/24/2016] [Indexed: 11/17/2022]
Abstract
PRDM4 is a member of the PRDM family of transcriptional regulators which control various aspects of cellular differentiation and proliferation. PRDM proteins exert their biological functions both in the cytosol and the nucleus of cells. All PRDM proteins are characterised by the presence of two distinct structural motifs, the PR/SET domain and the zinc finger (ZF) motifs. We previously observed that deletion of all six zinc fingers found in PRDM4 leads to its accumulation in the cytosol, whereas overexpressed full length PRDM4 is found predominantly in the nucleus. Here, we investigated the requirements for single zinc fingers in the nuclear localisation of PRDM4. We demonstrate that ZF's 1, 2, 5 and 6 contribute to the accumulation of PRDM4 in the nucleus. Their effect is additive as deleting either ZF1-2 or ZF 5-6 redistributes PRDM4 protein from being almost exclusively nuclear to cytosolic and nuclear. We investigated the potential mechanism of nuclear shuttling of PRDM4 via the importin α/β-mediated pathway and find that PRDM4 nuclear targeting is independent of α/β-mediated nuclear import.
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Affiliation(s)
- Hale Tunbak
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK.
| | - Christiana Georgiou
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK.
| | - Cui Guan
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| | - William David Richardson
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK.
| | - Alexandra Chittka
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK.
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