1
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Ito T. Molecular pathology of small cell lung cancer: Overview from studies on neuroendocrine differentiation regulated by ASCL1 and Notch signaling. Pathol Int 2024; 74:239-251. [PMID: 38607250 DOI: 10.1111/pin.13426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 03/20/2024] [Accepted: 03/24/2024] [Indexed: 04/13/2024]
Abstract
Pulmonary neuroendocrine (NE) cells are rare airway epithelial cells. The balance between Achaete-scute complex homolog 1 (ASCL1) and hairy and enhancer of split 1, one of the target molecules of the Notch signaling pathway, is crucial for NE differentiation. Small cell lung cancer (SCLC) is a highly aggressive lung tumor, characterized by rapid cell proliferation, a high metastatic potential, and the acquisition of resistance to treatment. The subtypes of SCLC are defined by the expression status of NE cell-lineage transcription factors, such as ASCL1, which roles are supported by SRY-box 2, insulinoma-associated protein 1, NK2 homeobox 1, and wingless-related integration site signaling. This network reinforces NE differentiation and may induce the characteristic morphology and chemosensitivity of SCLC. Notch signaling mediates cell-fate decisions, resulting in an NE to non-NE fate switch. The suppression of NE differentiation may change the histological type of SCLC to a non-SCLC morphology. In SCLC with NE differentiation, Notch signaling is typically inactive and genetically or epigenetically regulated. However, Notch signaling may be activated after chemotherapy, and, in concert with Yes-associated protein signaling and RE1-silencing transcription factor, suppresses NE differentiation, producing intratumor heterogeneity and chemoresistance. Accumulated information on the molecular mechanisms of SCLC will contribute to further advances in the control of this recalcitrant cancer.
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Grants
- 20H03691 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 18K19489 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 16590318 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 25460439 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- Smoking Research Foundation, Japan
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Affiliation(s)
- Takaaki Ito
- Department of Medical Technology, Kumamoto Health Science University Faculty of Health Sciences, Kumamoto, Japan
- Department of Pathology and Experimental Medicine, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
- Department of Brain Morphogenesis, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
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2
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Pavlou M, Probst M, Blasdel N, Prieve AR, Reh TA. The impact of timing and injury mode on induced neurogenesis in the adult mammalian retina. Stem Cell Reports 2024; 19:239-253. [PMID: 38278154 PMCID: PMC10874861 DOI: 10.1016/j.stemcr.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/28/2024] Open
Abstract
Regeneration of neurons has important implications for human health, and the retina provides an accessible system to study the potential of replacing neurons following injury. In previous work, we generated transgenic mice in which neurogenic transcription factors were expressed in Müller glia (MG) and showed that they stimulated neurogenesis following inner retinal damage. It was unknown, however, whether the timing or mode of injury mattered in this process. Here, we explored these parameters on induced neurogenesis from MG and show that MG expressing Ascl1 will generate new bipolar neurons with similar efficiency irrespective of injury mode or timing. However, MG that express Ascl1-Atoh1 produce a new type of retinal ganglion-like cell after outer retinal damage, which is absent with inner retinal damage. Our data suggest that although cell fate is primarily dictated by neurogenic transcription factors, the inflammatory state of MG relative to injury can influence the outcome of induced neurogenesis.
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Affiliation(s)
- Marina Pavlou
- Department of Biological Structure, University of Washington, Seattle, WA, USA; Institute for Stem Cells and Regenerative Medicine, University of Washington, Seattle, WA, USA
| | - Marlene Probst
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Nicolai Blasdel
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Aric R Prieve
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, WA, USA; Institute for Stem Cells and Regenerative Medicine, University of Washington, Seattle, WA, USA.
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3
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Li Z, Li H, Yu X, Zhou J, Dong ZY, Meng X. bHLH transcription factors Hes1, Ascl1 and Oligo2 exhibit different expression patterns in the process of physiological electric fields-induced neuronal differentiation. Mol Biol Rep 2024; 51:115. [PMID: 38227267 DOI: 10.1007/s11033-023-09118-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 12/06/2023] [Indexed: 01/17/2024]
Abstract
BACKGROUND Recent studies have shown that the expression of bHLH transcription factors Hes1, Ascl1, and Oligo2 has an oscillating balance in neural stem cells (NSCs) to maintain their self-proliferation and multi-directional differentiation potential. This balance can be disrupted by exogenous stimulation. Our previous work has identified that electrical stimulation could induce neuronal differentiation of mouse NSCs. METHODS To further evaluate if physiological electric fields (EFs)-induced neuronal differentiation is related to the expression patterns of bHLH transcription factors Hes1, Ascl1, and Oligo2, mouse embryonic brain NSCs were used to investigate the expression changes of Ascl1, Hes1 and Oligo2 in mRNA and protein levels during EF-induced neuronal differentiation. RESULTS Our results showed that NSCs expressed high level of Hes1, while expression of Ascl1 and Oligo2 stayed at very low levels. When NSCs exited proliferation, the expression of Hes1 in differentiated cells began to decrease and oscillated at the low expression level. Oligo2 showed irregular changes in low expression level. EF-stimulation significantly increased the expression of Ascl1 at mRNA and protein levels accompanied by an increased percentage of neuronal differentiation. What's more, over-expression of Hes1 inhibited the neuronal differentiation induced by EFs. CONCLUSION EF-stimulation directed neuronal differentiation of NSCs by promoting the continuous accumulation of Ascl1 expression and decreasing the expression of Hes1.
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Affiliation(s)
- Zhe Li
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun, 130021, People's Republic of China
| | - Hai Li
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun, 130021, People's Republic of China
- Department of Radiology, The First Hospital, Jilin University, Changchun, 130041, People's Republic of China
| | - Xiyao Yu
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun, 130021, People's Republic of China
| | - Jiaying Zhou
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun, 130021, People's Republic of China
| | - Zhi Yong Dong
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun, 130021, People's Republic of China
| | - Xiaoting Meng
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun, 130021, People's Republic of China.
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4
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Altbürger C, Rath M, Wehrle J, Driever W. The proneural factors Ascl1a and Ascl1b contribute to the terminal differentiation of dopaminergic GABAergic dual transmitter neurons in zebrafish. Dev Biol 2024; 505:58-74. [PMID: 37931393 DOI: 10.1016/j.ydbio.2023.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 10/06/2023] [Accepted: 10/23/2023] [Indexed: 11/08/2023]
Abstract
The proneural factor Ascl1 is involved in several steps of neurogenesis, from neural progenitor maintenance to initiation of terminal differentiation and neuronal subtype specification. In neural progenitor cells, Ascl1 initiates the cell-cycle exit of progenitors, and contributes to their differentiation into mainly GABAergic neurons. Several catecholaminergic neuron groups in the forebrain of zebrafish use GABA as co-transmitter, but a potential role of the two paralogues Ascl1a and Ascl1b in their neurogenesis is not understood. Here, we show that ascl1a, ascl1b double mutant embryos develop a significantly reduced number of neurons in all GABAergic and catecholaminergic dual transmitter neuron anatomical clusters in the fore- and hindbrain, while glutamatergic catecholaminergic clusters develop normally. However, none of the affected catecholaminergic cell clusters are lost completely, suggesting an impairment in progenitor pools, or a requirement of Ascl1a/b for differentiation of a subset of neurons in each cluster. Early progenitors which are dlx2a+, fezf2 + or emx2 + are not reduced whereas late progenitors and differentiating neurons marked by the expression of dlx5a, isl1 and arxa are severely reduced in ascl1a, ascl1b double mutant embryos. This suggests that Ascl1a and Ascl1b play only a minor or no role in the maintenance of their progenitor pools, but rather contribute to the initiation of terminal differentiation of GABAergic catecholaminergic neurons.
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Affiliation(s)
- Christian Altbürger
- Department of Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University, Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany; CIBSS and BIOSS - Centres for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Meta Rath
- Department of Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University, Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany
| | - Johanna Wehrle
- Department of Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University, Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany; MeInBio Research Training Group, University of Freiburg, 79104, Freiburg, Germany
| | - Wolfgang Driever
- Department of Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University, Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany; CIBSS and BIOSS - Centres for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany.
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5
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Osipovich AB, Zhou FY, Chong JJ, Trinh LT, Cottam MA, Shrestha S, Cartailler JP, Magnuson MA. Deletion of Ascl1 in pancreatic β-cells improves insulin secretion, promotes parasympathetic innervation, and attenuates dedifferentiation during metabolic stress. Mol Metab 2023; 78:101811. [PMID: 37769990 PMCID: PMC10570713 DOI: 10.1016/j.molmet.2023.101811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/03/2023] Open
Abstract
OBJECTIVE ASCL1, a pioneer transcription factor, is essential for neural cell differentiation and function. Previous studies have shown that Ascl1 expression is increased in pancreatic β-cells lacking functional KATP channels or after feeding of a high fat diet (HFD) suggesting that it may contribute to the metabolic stress response of β-cells. METHODS We generated β-cell-specific Ascl1 knockout mice (Ascl1βKO) and assessed their glucose homeostasis, islet morphology and gene expression after feeding either a normal diet or HFD for 12 weeks, or in combination with a genetic disruption of Abcc8, an essential KATP channel component. RESULTS Ascl1 expression is increased in response to both a HFD and membrane depolarization and requires CREB-dependent Ca2+ signaling. No differences in glucose homeostasis or islet morphology were observed in Ascl1βKO mice fed a normal diet or in the absence of KATP channels. However, male Ascl1βKO mice fed a HFD exhibited decreased blood glucose levels, improved glucose tolerance, and increased β-cell proliferation. Bulk RNA-seq analysis of islets from Ascl1βKO mice from three studied conditions showed alterations in genes associated with the secretory function. HFD-fed Ascl1βKO mice showed the most extensive changes with increased expression of genes necessary for glucose sensing, insulin secretion and β-cell proliferation, and a decrease in genes associated with β-cell dysfunction, inflammation and dedifferentiation. HFD-fed Ascl1βKO mice also displayed increased expression of parasympathetic neural markers and cholinergic receptors that was accompanied by increased insulin secretion in response to acetylcholine and an increase in islet innervation. CONCLUSIONS Ascl1 expression is induced by stimuli that cause Ca2+-signaling to the nucleus and contributes in a multifactorial manner to the loss of β-cell function by promoting the expression of genes associated with cellular dedifferentiation, attenuating β-cells proliferation, suppressing acetylcholine sensitivity, and repressing parasympathetic innervation of islets. Thus, the removal of Ascl1 from β-cells improves their function in response to metabolic stress.
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Affiliation(s)
- Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Frank Y Zhou
- College of Arts and Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Judy J Chong
- College of Arts and Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Linh T Trinh
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mathew A Cottam
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Shristi Shrestha
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | | | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.
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6
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Echegaray CV. Unleashing Ascl1: Exploring Cross-Lineage Potential in Reprogramming and Regenerative Frontiers. Cell Reprogram 2023; 25:139-141. [PMID: 37590007 DOI: 10.1089/cell.2023.0080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023] Open
Abstract
In the era of stem cell research and regenerative medicine, understanding the regulatory networks that drive cellular reprogramming is fundamental. The study entitled "Cross-lineage potential of Ascl1 uncovered by comparing diverse reprogramming regulatomes" published in Stem Cell Reports sheds light on the remarkable versatility of Ascl1, a transcription factor known for its pivotal role in neurogenesis. By comparing regulatomes across multiple cell lineages, the authors have elucidated the potential of Ascl1 to facilitate the conversion of non-neural cells into various lineages beyond its canonical neural fate, suggesting its potential as a master regulator for lineage reprogramming. These observations challenge our current understanding of cell fate determination and open exciting avenues for regenerative medicine.
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Affiliation(s)
- Camila Vazquez Echegaray
- Department of Laboratory Medicine, Division of Molecular Medicine and Gene Therapy, Lund Stem Cell Centre, Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
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7
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Gong W, Dsouza N, Garry DJ. SeATAC: a tool for exploring the chromatin landscape and the role of pioneer factors. Genome Biol 2023; 24:125. [PMID: 37218013 DOI: 10.1186/s13059-023-02954-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 04/27/2023] [Indexed: 05/24/2023] Open
Abstract
Assay for Transposase-Accessible Chromatin with sequencing (ATAC-seq) reveals chromatin accessibility across the genome. Currently, no method specifically detects differential chromatin accessibility. Here, SeATAC uses a conditional variational autoencoder model to learn the latent representation of ATAC-seq V-plots and outperforms MACS2 and NucleoATAC on six separate tasks. Applying SeATAC to several pioneer factor-induced differentiation or reprogramming ATAC-seq datasets suggests that induction of these factors not only relaxes the closed chromatin but also decreases chromatin accessibility of 20% to 30% of their target sites. SeATAC is a novel tool to accurately reveal genomic regions with differential chromatin accessibility from ATAC-seq data.
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Affiliation(s)
- Wuming Gong
- Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, MN, 55455, USA.
- Lillehei Heart Institute, University of Minnesota, 2231 6Th St SE, Minneapolis, MN, 55455, USA.
| | - Nikita Dsouza
- Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Daniel J Garry
- Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, MN, 55455, USA.
- Lillehei Heart Institute, University of Minnesota, 2231 6Th St SE, Minneapolis, MN, 55455, USA.
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, 55455, USA.
- Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota, Minneapolis, MN, 55455, USA.
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8
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Matsuyama K, Takai S, Shigemura N, Nakatomi M, Kawamoto T, Kataoka S, Toyono T, Seta Y. Ascl1-expressing cell differentiation in initially developed taste buds and taste organoids. Cell Tissue Res 2023:10.1007/s00441-023-03756-8. [PMID: 36781481 DOI: 10.1007/s00441-023-03756-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/30/2023] [Indexed: 02/15/2023]
Abstract
Mammalian taste bud cells are composed of several distinct cell types and differentiated from surrounding tongue epithelial cells. However, the detailed mechanisms underlying their differentiation have yet to be elucidated. In the present study, we examined an Ascl1-expressing cell lineage using circumvallate papillae (CVP) of newborn mice and taste organoids (three-dimensional self-organized tissue cultures), which allow studying the differentiation of taste bud cells in fine detail ex vivo. Using lineage-tracing analysis, we observed that Ascl1 lineage cells expressed type II and III taste cell markers both CVP of newborn mice and taste organoids. However, the coexpression rate in type II cells was lower than that in type III cells. Furthermore, we found that the generation of the cells which express type II and III cell markers was suppressed in taste organoids lacking Ascl1-expressing cells. These findings suggest that Ascl1-expressing precursor cells can differentiate into both type III and a subset of type II taste cells.
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Affiliation(s)
- Kae Matsuyama
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan.
| | - Shingo Takai
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Noriatsu Shigemura
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.,Research and Development Center for Five-Sense Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Mitsushiro Nakatomi
- Department of Human, Information and Life Sciences, School of Health Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Tatsuo Kawamoto
- Division of Orofacial Functions and Orthodontics, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
| | - Shinji Kataoka
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
| | - Takashi Toyono
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
| | - Yuji Seta
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
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9
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Centonze G, Maisonneuve P, Simbolo M, Lagano V, Grillo F, Prinzi N, Pusceddu S, Missiato L, Colantuono M, Sabella G, Bercich L, Mangogna A, Rolli L, Grisanti S, Benvenuti MR, Pastorino U, Roz L, Scarpa A, Berruti A, Capella C, Milione M. Ascl1 and OTP tumour expressions are associated with disease-free survival in lung atypical carcinoids. Histopathology 2023; 82:870-884. [PMID: 36720841 DOI: 10.1111/his.14873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/11/2023] [Accepted: 01/28/2023] [Indexed: 02/02/2023]
Abstract
According to World Health Organization guidelines, atypical carcinoids (ACs) are well-differentiated lung neuroendocrine tumours with 2-10 mitoses/2 mm2 and/or foci of necrosis (usually punctate). Besides morphological criteria, no further tools in predicting AC clinical outcomes are proposed. The aim of this work was to identify novel factors able to predict AC disease aggressiveness and progression. METHODS AND RESULTS: Three hundred-seventy lung carcinoids were collected and centrally reviewed by two expert pathologists. Morphology and immunohistochemical markers (Ki-67, TTF-1, CD44, OTP, SSTR2A, Ascl1, p53, and Rb1) were studied and correlated with disease-free survival (DFS) and overall survival (OS). Fifty-eight of 370 tumours were defined as AC. Survival analysis showed that patients with Ascl1 + ACs and those with OTP-ACs had a significantly worse DFS than patients with Ascl1-ACs and OTP + ACs, respectively. Combining Ascl1 and OTP expressions, groups were formed reflecting the aggressiveness of disease (P = 0.0005). Ki-67 ≥10% patients had a significantly worse DFS than patients with Ki-67 <10%. At multivariable analysis, Ascl1 (present versus absent, hazard ratio [HR] = 3.42, 95% confidence interval [CI] 1.35-8.65, P = 0.009) and OTP (present versus absent, HR = 0.26, 95% CI 0.10-0.68, P = 0.006) were independently associated with DFS. The prognosis of patients with Ki-67 ≥10% tended to be worse compared to that with Ki-67 <10%. On the contrary, OTP (present versus absent, HR = 0.28, 95% CI 0.09-0.89, P = 0.03), tumour stage (III-IV versus I-II, HR = 4.25, 95% CI 1.42-12.73, P = 0.01) and increasing age (10-year increase, HR = 1.67, 95% CI 1.04-2.68, P = 0.03) were independently associated with OS. CONCLUSION: This retrospective analysis of lung ACs showed that Ascl1 and OTP could be the main prognostic drivers of postoperative recurrence.
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Affiliation(s)
- Giovanni Centonze
- 1st Pathology Division, Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Tumor Genomics Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Patrick Maisonneuve
- Division of Epidemiology and Biostatistics, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Michele Simbolo
- Department of Diagnostics and Public Health, Section of Pathology, University of Verona, Verona, Italy
| | - Vincenzo Lagano
- 1st Pathology Division, Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Federica Grillo
- Unit of Pathology, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa and Ospedale Policlinico San Martino, Genoa, Italy
| | - Natalie Prinzi
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Sara Pusceddu
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Loretta Missiato
- 1st Pathology Division, Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Marilena Colantuono
- 1st Pathology Division, Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Giovanna Sabella
- 1st Pathology Division, Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Luisa Bercich
- Department of Pathology, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Alessandro Mangogna
- Institute for Maternal and Child Health, IRCCS Burlo Garofalo, Trieste, Italy
| | - Luigi Rolli
- Thoracic Surgery Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - Salvatore Grisanti
- Medical Oncology Unit, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, ASST Spedali Civili, Brescia, Italy
| | - Mauro Roberto Benvenuti
- Thoracic Surgery Unit, Department of Medical and Surgical Specialties Radiological Sciences and Public Health, Medical Oncology, University of Brescia, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Ugo Pastorino
- Thoracic Surgery Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - Luca Roz
- Tumor Genomics Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Aldo Scarpa
- Department of Diagnostics and Public Health, Section of Pathology, University of Verona, Verona, Italy.,ARC-NET Research Center for Applied Research on Cancer, and Department of Diagnostics and Public Health, Section of Pathology, University of Verona, Verona, Italy
| | - Alfredo Berruti
- Medical Oncology Unit, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, ASST Spedali Civili, Brescia, Italy
| | - Carlo Capella
- Unit of Pathology, Department of Medicine and Surgery, University of Insubria, Varese, Italy
| | - Massimo Milione
- 1st Pathology Division, Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
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10
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Galante C, Marichal N, Scarante FF, Ghayad LM, Shi Y, Schuurmans C, Berninger B, Péron S. Corrigendum: Enhanced proliferation of oligodendrocyte progenitor cells following retrovirus mediated Achaete-scute complex-like 1 overexpression in the postnatal cerebral cortex in vivo. Front Neurosci 2023; 17:1198640. [PMID: 37168927 PMCID: PMC10166108 DOI: 10.3389/fnins.2023.1198640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 04/03/2023] [Indexed: 05/13/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fnins.2022.919462.].
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Affiliation(s)
- Chiara Galante
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg University, Mainz, Germany
| | - Nicolás Marichal
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Franciele Franco Scarante
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Litsa Maria Ghayad
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Youran Shi
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
- The Francis Crick Institute, London, United Kingdom
| | - Carol Schuurmans
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Benedikt Berninger
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg University, Mainz, Germany
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
- The Francis Crick Institute, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
- Focus Program Translational Neuroscience, Johannes Gutenberg University, Mainz, Germany
- Benedikt Berninger
| | - Sophie Péron
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg University, Mainz, Germany
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
- *Correspondence: Sophie Péron
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11
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Janas JA, Zhang L, Luu JH, Demeter J, Meng L, Marro SG, Mall M, Mooney NA, Schaukowitch K, Ng YH, Yang N, Huang Y, Neumayer G, Gozani O, Elias JE, Jackson PK, Wernig M. Tip60-mediated H2A.Z acetylation promotes neuronal fate specification and bivalent gene activation. Mol Cell 2022; 82:4627-4646.e14. [PMID: 36417913 PMCID: PMC9779922 DOI: 10.1016/j.molcel.2022.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 08/28/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
Cell lineage specification is accomplished by a concerted action of chromatin remodeling and tissue-specific transcription factors. However, the mechanisms that induce and maintain appropriate lineage-specific gene expression remain elusive. Here, we used an unbiased proteomics approach to characterize chromatin regulators that mediate the induction of neuronal cell fate. We found that Tip60 acetyltransferase is essential to establish neuronal cell identity partly via acetylation of the histone variant H2A.Z. Despite its tight correlation with gene expression and active chromatin, loss of H2A.Z acetylation had little effect on chromatin accessibility or transcription. Instead, loss of Tip60 and acetyl-H2A.Z interfered with H3K4me3 deposition and activation of a unique subset of silent, lineage-restricted genes characterized by a bivalent chromatin configuration at their promoters. Altogether, our results illuminate the mechanisms underlying bivalent chromatin activation and reveal that H2A.Z acetylation regulates neuronal fate specification by establishing epigenetic competence for bivalent gene activation and cell lineage transition.
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Affiliation(s)
- Justyna A Janas
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lichao Zhang
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jacklyn H Luu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Janos Demeter
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lingjun Meng
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Samuele G Marro
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Moritz Mall
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nancie A Mooney
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Katie Schaukowitch
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yi Han Ng
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nan Yang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yuhao Huang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gernot Neumayer
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Or Gozani
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Joshua E Elias
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peter K Jackson
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marius Wernig
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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12
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Galante C, Marichal N, Scarante FF, Ghayad LM, Shi Y, Schuurmans C, Berninger B, Péron S. Enhanced proliferation of oligodendrocyte progenitor cells following retrovirus mediated Achaete-scute complex-like 1 overexpression in the postnatal cerebral cortex in vivo. Front Neurosci 2022; 16:919462. [PMID: 36532282 PMCID: PMC9755855 DOI: 10.3389/fnins.2022.919462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 11/09/2022] [Indexed: 12/03/2022] Open
Abstract
The proneural transcription factor Achaete-scute complex-like 1 (Ascl1) is a major regulator of neural fate decisions, implicated both in neurogenesis and oligodendrogliogenesis. Focusing on its neurogenic activity, Ascl1 has been widely used to reprogram non-neuronal cells into induced neurons. In vitro, Ascl1 induces efficient reprogramming of proliferative astroglia from the early postnatal cerebral cortex into interneuron-like cells. Here, we examined whether Ascl1 can similarly induce neuronal reprogramming of glia undergoing proliferation in the postnatal mouse cerebral cortex in vivo. Toward this goal, we targeted cortical glia during the peak of proliferative expansion (i.e., postnatal day 5) by injecting a retrovirus encoding for Ascl1 into the mouse cerebral cortex. In contrast to the efficient reprogramming observed in vitro, in vivo Ascl1-transduced glial cells were converted into doublecortin-immunoreactive neurons only with very low efficiency. However, we noted a drastic shift in the relative number of retrovirus-transduced Sox10-positive oligodendrocyte progenitor cells (OPCs) as compared to glial fibrillary acidic protein (GFAP)-positive astrocytes. Genetic fate mapping demonstrated that this increase in OPCs was not due to Ascl1-mediated astrocyte-to-OPC fate conversion. Rather, EdU incorporation experiments revealed that Ascl1 caused a selective increase in proliferative activity of OPCs, but not astrocytes. Our data indicate that rather than inducing neuronal reprogramming of glia in the early postnatal cortex, Ascl1 is a selective enhancer of OPC proliferation.
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Affiliation(s)
- Chiara Galante
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg University, Mainz, Germany
| | - Nicolás Marichal
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Franciele Franco Scarante
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom,Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Litsa Maria Ghayad
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Youran Shi
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom,The Francis Crick Institute, London, United Kingdom
| | - Carol Schuurmans
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada,Department of Biochemistry, University of Toronto, Toronto, ON, Canada,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Benedikt Berninger
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg University, Mainz, Germany,Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom,The Francis Crick Institute, London, United Kingdom,MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom,Focus Program Translational Neuroscience, Johannes Gutenberg University, Mainz, Germany,Benedikt Berninger,
| | - Sophie Péron
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg University, Mainz, Germany,Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom,*Correspondence: Sophie Péron,
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13
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Wang H, Keepers B, Qian Y, Xie Y, Colon M, Liu J, Qian L. Cross-lineage potential of Ascl1 uncovered by comparing diverse reprogramming regulatomes. Cell Stem Cell 2022; 29:1491-1504.e9. [PMID: 36206732 PMCID: PMC9557912 DOI: 10.1016/j.stem.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 08/10/2022] [Accepted: 09/15/2022] [Indexed: 11/22/2022]
Abstract
Direct reprogramming has revolutionized the fields of stem cell biology and regenerative medicine. However, the common mechanisms governing how reprogramming cells undergo transcriptome and epigenome remodeling (i.e., regulatome remodeling) have not been investigated. Here, by characterizing early changes in the regulatome of three different types of direct reprogramming, we identify lineage-specific features as well as common regulatory transcription factors. Of particular interest, we discover that the neuronal factor Ascl1 possesses cross-lineage potential; together with Mef2c, it drives efficient cardiac reprogramming toward a mature and induced cardiomyocyte phenotype. Through ChIP-seq and RNA-seq, we find that MEF2C drives the shift in ASCL1 binding away from neuronal genes toward cardiac genes, guiding their co-operative epigenetic and transcription activities. Together, these findings demonstrate the existence of common regulators of different direct reprogramming and argue against the premise that transcription factors possess only lineage-specific capabilities for altering cell fate - the basic premise used to develop direct reprogramming approaches.
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Affiliation(s)
- Haofei Wang
- The McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Benjamin Keepers
- The McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Yunzhe Qian
- The McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yifang Xie
- The McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Marazzano Colon
- The McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jiandong Liu
- The McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Li Qian
- The McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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14
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Hermans BCM, Derks JL, Hillen LM, van der Baan I, van den Broek EC, von der Thüsen JH, van Suylen R, Atmodimedjo PN, den Toom TD, Coumans‐Stallinga C, Timens W, Dinjens WNM, Dubbink HJ, Speel EM, Dingemans AC. In-depth molecular analysis of combined and co-primary pulmonary large cell neuroendocrine carcinoma and adenocarcinoma. Int J Cancer 2022; 150:802-815. [PMID: 34674268 PMCID: PMC9298697 DOI: 10.1002/ijc.33853] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/22/2021] [Accepted: 09/20/2021] [Indexed: 01/09/2023]
Abstract
Up to 14% of large cell neuroendocrine carcinomas (LCNECs) are diagnosed in continuity with nonsmall cell lung carcinoma. In addition to these combined lesions, 1% to 7% of lung tumors present as co-primary tumors with multiple synchronous lesions. We evaluated molecular and clinicopathological characteristics of combined and co-primary LCNEC-adenocarcinoma (ADC) tumors. Ten patients with LCNEC-ADC (combined) and five patients with multiple synchronous ipsilateral LCNEC and ADC tumors (co-primary) were included. DNA was isolated from distinct tumor parts, and 65 cancer genes were analyzed by next generation sequencing. Immunohistochemistry was performed including neuroendocrine markers, pRb, Ascl1 and Rest. Pure ADC (N = 37) and LCNEC (N = 17) cases were used for reference. At least 1 shared mutation, indicating tumor clonality, was found in LCNEC- and ADC-parts of 10/10 combined tumors but only in 1/5 co-primary tumors. A range of identical mutations was observed in both parts of combined tumors: 8/10 contained ADC-related (EGFR/KRAS/STK11 and/or KEAP1), 4/10 RB1 and 9/10 TP53 mutations. Loss of pRb IHC was observed in 6/10 LCNEC- and 4/10 ADC-parts. The number and intensity of expression of Ascl1 and neuroendocrine markers increased from pure ADC (low) to combined ADC (intermediate) and combined and pure LCNEC (high). The opposite was true for Rest expression. In conclusion, all combined LCNEC-ADC tumors were clonally related indicating a common origin. A relatively high frequency of pRb inactivation was observed in both LCNEC- and ADC-parts, suggesting an underlying role in LCNEC-ADC development. Furthermore, neuroendocrine differentiation might be modulated by Ascl1(+) and Rest(-) expression.
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Affiliation(s)
- Bregtje C. M. Hermans
- Department of Pulmonary DiseasesMaastricht University Medical Centre+MaastrichtThe Netherlands,GROW—School for Oncology & Developmental BiologyMaastricht UniversityMaastrichtThe Netherlands
| | - Jules L. Derks
- Department of Pulmonary DiseasesMaastricht University Medical Centre+MaastrichtThe Netherlands,GROW—School for Oncology & Developmental BiologyMaastricht UniversityMaastrichtThe Netherlands
| | - Lisa M. Hillen
- GROW—School for Oncology & Developmental BiologyMaastricht UniversityMaastrichtThe Netherlands,Department of PathologyMaastricht University Medical Centre+MaastrichtThe Netherlands
| | - Irene van der Baan
- GROW—School for Oncology & Developmental BiologyMaastricht UniversityMaastrichtThe Netherlands,Department of PathologyMaastricht University Medical Centre+MaastrichtThe Netherlands
| | | | - Jan H. von der Thüsen
- Department of PathologyErasmus MC Cancer Institute, University Medical Center RotterdamRotterdamThe Netherlands
| | | | - Peggy N. Atmodimedjo
- Department of PathologyErasmus MC Cancer Institute, University Medical Center RotterdamRotterdamThe Netherlands
| | - T. Dorine den Toom
- Department of PathologyErasmus MC Cancer Institute, University Medical Center RotterdamRotterdamThe Netherlands
| | - Cecile Coumans‐Stallinga
- GROW—School for Oncology & Developmental BiologyMaastricht UniversityMaastrichtThe Netherlands,Department of PathologyMaastricht University Medical Centre+MaastrichtThe Netherlands
| | - Wim Timens
- Department of Pathology and Medical BiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Winand N. M. Dinjens
- Department of PathologyErasmus MC Cancer Institute, University Medical Center RotterdamRotterdamThe Netherlands
| | - Hendrikus J. Dubbink
- Department of PathologyErasmus MC Cancer Institute, University Medical Center RotterdamRotterdamThe Netherlands
| | - Ernst‐Jan M. Speel
- GROW—School for Oncology & Developmental BiologyMaastricht UniversityMaastrichtThe Netherlands,Department of PathologyMaastricht University Medical Centre+MaastrichtThe Netherlands
| | - Anne‐Marie C. Dingemans
- Department of Pulmonary DiseasesMaastricht University Medical Centre+MaastrichtThe Netherlands,GROW—School for Oncology & Developmental BiologyMaastricht UniversityMaastrichtThe Netherlands,Department of PulmonologyErasmus MC Cancer Institute, University Medical Center RotterdamRotterdamThe Netherlands
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15
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Javed K, Jullien J, Agarwal G, Lawrence N, Butler R, Ioannou PS, Nazir F, Gurdon JB. DNA-induced spatial entrapment of general transcription machinery can stabilize gene expression in a nondividing cell. Proc Natl Acad Sci U S A 2022; 119:e2116091119. [PMID: 35074915 DOI: 10.1073/pnas.2116091119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2021] [Indexed: 12/03/2022] Open
Abstract
How differentiated cells such as muscle or nerve maintain their gene expression for prolonged times is currently elusive. Here, using Xenopus oocyte, we have shown that the stability of gene expression in nondividing cells may arise due to the local entrapment of transcriptional machinery to specific gene transcription start sites. We found that within the same nucleus active versus inactive versions of the same gene are spatially segregated through liquid–liquid phase separation. We further observe that silent genes are associated with RNA-Pol-II phosphorylated on Ser5 but fails to attract RNA-Pol-II elongation factors. We propose that liquid–liquid phase separation mediated entrapment of limiting transcriptional machinery factors maintain stable expression of some genes in nondividing cells. An important characteristic of cell differentiation is its stability. Only rarely do cells or their stem cell progenitors change their differentiation pathway. If they do, it is often accompanied by a malfunction such as cancer. A mechanistic understanding of the stability of differentiated states would allow better prospects of alleviating the malfunctioning. However, such complete information is yet elusive. Earlier experiments performed in Xenopus oocytes to address this question suggest that a cell may maintain its gene expression by prolonged binding of cell type–specific transcription factors. Here, using DNA competition experiments, we show that the stability of gene expression in a nondividing cell could be caused by the local entrapment of part of the general transcription machinery in transcriptionally active regions. Strikingly, we found that transcriptionally active and silent forms of the same DNA template can stably coexist within the same nucleus. Both DNA templates are associated with the gene-specific transcription factor Ascl1, the core factor TBP2, and the polymerase II (Pol-II) ser5 C-terminal domain (CTD) phosphorylated form, while Pol-II ser2 CTD phosphorylation is restricted to the transcriptionally dominant template. We discover that the active and silent DNA forms are physically separated in the oocyte nucleus through partition into liquid–liquid phase-separated condensates. Altogether, our study proposes a mechanism of transcriptional regulation involving a spatial entrapment of general transcription machinery components to stabilize the active form of a gene in a nondividing cell.
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16
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Kaise T, Fukui M, Sueda R, Piao W, Yamada M, Kobayashi T, Imayoshi I, Kageyama R. Functional rejuvenation of aged neural stem cells by Plagl2 and anti-Dyrk1a activity. Genes Dev 2021. [PMID: 34916302 DOI: 10.1101/gad.349000.121] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 11/29/2021] [Indexed: 11/27/2022]
Abstract
Here, Kaise et al. searched for a gene combination that can rejuvenate NSCs in the aged mouse brain from nuclear factors differentially expressed between embryonic and adult NSCs and their modulators. They found that a combination of inducing the zinc finger transcription factor gene Plagl2 and inhibiting Dyrk1a, a gene associated with Down syndrome, rejuvenated aged hippocampal NSCs, and they conclude that aging of NSCs can be reversed to induce functional neurogenesis continuously. The regenerative potential of neural stem cells (NSCs) declines during aging, leading to cognitive dysfunctions. This decline involves up-regulation of senescence-associated genes, but inactivation of such genes failed to reverse aging of hippocampal NSCs. Because many genes are up-regulated or down-regulated during aging, manipulation of single genes would be insufficient to reverse aging. Here we searched for a gene combination that can rejuvenate NSCs in the aged mouse brain from nuclear factors differentially expressed between embryonic and adult NSCs and their modulators. We found that a combination of inducing the zinc finger transcription factor gene Plagl2 and inhibiting Dyrk1a, a gene associated with Down syndrome (a genetic disorder known to accelerate aging), rejuvenated aged hippocampal NSCs, which already lost proliferative and neurogenic potential. Such rejuvenated NSCs proliferated and produced new neurons continuously at the level observed in juvenile hippocampi, leading to improved cognition. Epigenome, transcriptome, and live-imaging analyses indicated that this gene combination induces up-regulation of embryo-associated genes and down-regulation of age-associated genes by changing their chromatin accessibility, thereby rejuvenating aged dormant NSCs to function like juvenile active NSCs. Thus, aging of NSCs can be reversed to induce functional neurogenesis continuously, offering a way to treat age-related neurological disorders.
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17
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Sahu A, Devi S, Jui J, Goldman D. Notch signaling via Hey1 and Id2b regulates Müller glia's regenerative response to retinal injury. Glia 2021; 69:2882-2898. [PMID: 34415582 DOI: 10.1002/glia.24075] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/02/2021] [Accepted: 08/05/2021] [Indexed: 02/01/2023]
Abstract
Zebrafish Müller glia (MG) respond to retinal injury by suppressing Notch signaling and producing progenitors for retinal repair. A certain threshold of injury-derived signal must be exceeded in order to engage MG in a regenerative response (MG's injury-response threshold). Pan-retinal Notch inhibition expands the zone of injury-responsive MG at the site of focal injury, suggesting that Notch signaling regulates MG's injury-response threshold. We found that Notch signaling enhanced chromatin accessibility and gene expression at a subset of regeneration-associated genes in the uninjured retina. Two Notch effector genes, hey1 and id2b, were identified that reflect bifurcation of the Notch signaling pathway, and differentially regulate MG's injury-response threshold and proliferation of MG-derived progenitors. Furthermore, Notch signaling component gene repression in the injured retina suggests a role for Dll4, Dlb, and Notch3 in regulating Notch signaling in MG and epistasis experiments confirm that the Dll4/Dlb-Notch3-Hey1/Id2b signaling pathway regulates MG's injury-response threshold and proliferation.
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Affiliation(s)
- Aresh Sahu
- Michigan Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Sulochana Devi
- Michigan Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Jonathan Jui
- Michigan Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Daniel Goldman
- Michigan Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
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18
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Kempf J, Knelles K, Hersbach BA, Petrik D, Riedemann T, Bednarova V, Janjic A, Simon-Ebert T, Enard W, Smialowski P, Götz M, Masserdotti G. Heterogeneity of neurons reprogrammed from spinal cord astrocytes by the proneural factors Ascl1 and Neurogenin2. Cell Rep 2021; 36:109409. [PMID: 34289357 PMCID: PMC8316252 DOI: 10.1016/j.celrep.2021.109409] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/14/2021] [Accepted: 06/24/2021] [Indexed: 01/21/2023] Open
Abstract
Astrocytes are a viable source for generating new neurons via direct conversion. However, little is known about the neurogenic cascades triggered in astrocytes from different regions of the CNS. Here, we examine the transcriptome induced by the proneural factors Ascl1 and Neurog2 in spinal cord-derived astrocytes in vitro. Each factor initially elicits different neurogenic programs that later converge to a V2 interneuron-like state. Intriguingly, patch sequencing (patch-seq) shows no overall correlation between functional properties and the transcriptome of the heterogenous induced neurons, except for K-channels. For example, some neurons with fully mature electrophysiological properties still express astrocyte genes, thus calling for careful molecular and functional analysis. Comparing the transcriptomes of spinal cord- and cerebral-cortex-derived astrocytes reveals profound differences, including developmental patterning cues maintained in vitro. These relate to the distinct neuronal identity elicited by Ascl1 and Neurog2 reflecting their developmental functions in subtype specification of the respective CNS region.
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Affiliation(s)
- J Kempf
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany
| | - K Knelles
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany
| | - B A Hersbach
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried 82152, Germany
| | - D Petrik
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; School of Biosciences, The Sir Martin Evans Building, Cardiff University, CF10 3AX Cardiff, UK
| | - T Riedemann
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany
| | - V Bednarova
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany
| | - A Janjic
- Anthropology and Human Genomics, Faculty of Biology, LMU Munich, Planegg-Martinsried 82152, Germany
| | - T Simon-Ebert
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany
| | - W Enard
- Biomedical Center Munich, Bioinformatic Core Facility, LMU Munich, Planegg-Martinsried 82152, Germany
| | - P Smialowski
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; School of Biosciences, The Sir Martin Evans Building, Cardiff University, CF10 3AX Cardiff, UK
| | - M Götz
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Excellence Cluster of Systems Neurology (SYNERGY), Munich, Germany.
| | - G Masserdotti
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany.
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19
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Soares MAF, Soares DS, Teixeira V, Heskol A, Bressan RB, Pollard SM, Oliveira RA, Castro DS. Hierarchical reactivation of transcription during mitosis-to-G1 transition by Brn2 and Ascl1 in neural stem cells. Genes Dev 2021; 35:1020-1034. [PMID: 34168041 PMCID: PMC8247608 DOI: 10.1101/gad.348174.120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/19/2021] [Indexed: 12/19/2022]
Abstract
During mitosis, chromatin condensation is accompanied by a global arrest of transcription. Recent studies suggest transcriptional reactivation upon mitotic exit occurs in temporally coordinated waves, but the underlying regulatory principles have yet to be elucidated. In particular, the contribution of sequence-specific transcription factors (TFs) remains poorly understood. Here we report that Brn2, an important regulator of neural stem cell identity, associates with condensed chromatin throughout cell division, as assessed by live-cell imaging of proliferating neural stem cells. In contrast, the neuronal fate determinant Ascl1 dissociates from mitotic chromosomes. ChIP-seq analysis reveals that Brn2 mitotic chromosome binding does not result in sequence-specific interactions prior to mitotic exit, relying mostly on electrostatic forces. Nevertheless, surveying active transcription using single-molecule RNA-FISH against immature transcripts reveals differential reactivation kinetics for key targets of Brn2 and Ascl1, with transcription onset detected in early (anaphase) versus late (early G1) phases, respectively. Moreover, by using a mitotic-specific dominant-negative approach, we show that competing with Brn2 binding during mitotic exit reduces the transcription of its target gene Nestin Our study shows an important role for differential binding of TFs to mitotic chromosomes, governed by their electrostatic properties, in defining the temporal order of transcriptional reactivation during mitosis-to-G1 transition.
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Affiliation(s)
- Mário A F Soares
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Diogo S Soares
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Vera Teixeira
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - Abeer Heskol
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Raul Bardini Bressan
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Steven M Pollard
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | | | - Diogo S Castro
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
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20
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Sueda R, Kageyama R. Oscillatory expression of Ascl1 in oligodendrogenesis. Gene Expr Patterns 2021; 41:119198. [PMID: 34175456 DOI: 10.1016/j.gep.2021.119198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/15/2021] [Accepted: 06/20/2021] [Indexed: 11/29/2022]
Abstract
The proneural gene Ascl1 promotes formation of both neurons and oligodendrocytes from neural stem cells (NSCs), but it remains to be analyzed how its different functions are coordinated. It was previously shown that Ascl1 enhances proliferation of NSCs when its expression oscillates but induces differentiation into transit-amplifying precursor cells and neurons when its expression is up-regulated and sustained. By time-lapse imaging and immunohistological analyses, we found that Ascl1 expression oscillated in proliferating oligodendrocyte precursor cells (OPCs) at lower levels than in transit-amplifying precursor cells and was repressed when OPCs differentiated into mature oligodendrocytes. Induction of sustained overexpression of Ascl1 reduced oligodendrocyte differentiation and promoted neuronal differentiation. These results suggest that oscillatory expression of Ascl1 plays an important role in proliferating OPCs during oligodendrocyte formation.
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Affiliation(s)
- Risa Sueda
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, 606-8507, Japan; Kyoto University Graduate School of Biostudies, Kyoto, 606-8501, Japan
| | - Ryoichiro Kageyama
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, 606-8507, Japan; Kyoto University Graduate School of Biostudies, Kyoto, 606-8501, Japan; Kyoto University Graduate School of Medicine, Kyoto, 606-8507, Japan; Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto, 606-8501, Japan; RIKEN Center for Brain Science, Wako, 351-0198, Japan.
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21
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Kaufman ML, Goodson NB, Park KU, Schwanke M, Office E, Schneider SR, Abraham J, Hensley A, Jones KL, Brzezinski JA. Initiation of Otx2 expression in the developing mouse retina requires a unique enhancer and either Ascl1 or Neurog2 activity. Development 2021; 148:dev199399. [PMID: 34143204 PMCID: PMC8254865 DOI: 10.1242/dev.199399] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/10/2021] [Indexed: 11/20/2022]
Abstract
During retinal development, a large subset of progenitors upregulates the transcription factor Otx2, which is required for photoreceptor and bipolar cell formation. How these retinal progenitor cells initially activate Otx2 expression is unclear. To address this, we investigated the cis-regulatory network that controls Otx2 expression in mice. We identified a minimal enhancer element, DHS-4D, that drove expression in newly formed OTX2+ cells. CRISPR/Cas9-mediated deletion of DHS-4D reduced OTX2 expression, but this effect was diminished in postnatal development. Systematic mutagenesis of the enhancer revealed that three basic helix-loop-helix (bHLH) transcription factor-binding sites were required for its activity. Single cell RNA-sequencing of nascent Otx2+ cells identified the bHLH factors Ascl1 and Neurog2 as candidate regulators. CRISPR/Cas9 targeting of these factors showed that only the simultaneous loss of Ascl1 and Neurog2 prevented OTX2 expression. Our findings suggest that Ascl1 and Neurog2 act either redundantly or in a compensatory fashion to activate the DHS-4D enhancer and Otx2 expression. We observed redundancy or compensation at both the transcriptional and enhancer utilization levels, suggesting that the mechanisms governing Otx2 regulation in the retina are flexible and robust.
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Affiliation(s)
- Michael L. Kaufman
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Noah B. Goodson
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ko Uoon Park
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Michael Schwanke
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Emma Office
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Sophia R. Schneider
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Joy Abraham
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Austin Hensley
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Kenneth L. Jones
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Joseph A. Brzezinski
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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22
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Wang X, Pei Z, Hossain A, Bai Y, Chen G. Transcription factor-based gene therapy to treat glioblastoma through direct neuronal conversion. Cancer Biol Med 2021; 18:j.issn.2095-3941.2020.0499. [PMID: 33755378 PMCID: PMC8330525 DOI: 10.20892/j.issn.2095-3941.2020.0499] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 12/30/2020] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Glioblastoma (GBM) is the most prevalent and aggressive adult primary cancer in the central nervous system. Therapeutic approaches for GBM treatment are under intense investigation, including the use of emerging immunotherapies. Here, we propose an alternative approach to treat GBM through reprogramming proliferative GBM cells into non-proliferative neurons. METHODS Retroviruses were used to target highly proliferative human GBM cells through overexpression of neural transcription factors. Immunostaining, electrophysiological recording, and bulk RNA-seq were performed to investigate the mechanisms underlying the neuronal conversion of human GBM cells. An in vivo intracranial xenograft mouse model was used to examine the neuronal conversion of human GBM cells. RESULTS We report efficient neuronal conversion from human GBM cells by overexpressing single neural transcription factor Neurogenic differentiation 1 (NeuroD1), Neurogenin-2 (Neurog2), or Achaete-scute homolog 1 (Ascl1). Subtype characterization showed that the majority of Neurog2- and NeuroD1-converted neurons were glutamatergic, while Ascl1 favored GABAergic neuron generation. The GBM cell-converted neurons not only showed pan-neuronal markers but also exhibited neuron-specific electrophysiological activities. Transcriptome analyses revealed that neuronal genes were activated in glioma cells after overexpression of neural transcription factors, and different signaling pathways were activated by different neural transcription factors. Importantly, the neuronal conversion of GBM cells was accompanied by significant inhibition of GBM cell proliferation in both in vitro and in vivo models. CONCLUSIONS These results suggest that GBM cells can be reprogrammed into different subtypes of neurons, leading to a potential alternative approach to treat brain tumors using in vivo cell conversion technology.
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Affiliation(s)
- Xin Wang
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Zifei Pei
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Aasma Hossain
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Yuting Bai
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Gong Chen
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
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23
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Oproescu AM, Han S, Schuurmans C. New Insights Into the Intricacies of Proneural Gene Regulation in the Embryonic and Adult Cerebral Cortex. Front Mol Neurosci 2021; 14:642016. [PMID: 33658912 PMCID: PMC7917194 DOI: 10.3389/fnmol.2021.642016] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/26/2021] [Indexed: 12/21/2022] Open
Abstract
Historically, the mammalian brain was thought to lack stem cells as no new neurons were found to be made in adulthood. That dogma changed ∼25 years ago with the identification of neural stem cells (NSCs) in the adult rodent forebrain. However, unlike rapidly self-renewing mature tissues (e.g., blood, intestinal crypts, skin), the majority of adult NSCs are quiescent, and those that become 'activated' are restricted to a few neurogenic zones that repopulate specific brain regions. Conversely, embryonic NSCs are actively proliferating and neurogenic. Investigations into the molecular control of the quiescence-to-proliferation-to-differentiation continuum in the embryonic and adult brain have identified proneural genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs) as critical regulators. These bHLH TFs initiate genetic programs that remove NSCs from quiescence and drive daughter neural progenitor cells (NPCs) to differentiate into specific neural cell subtypes, thereby contributing to the enormous cellular diversity of the adult brain. However, new insights have revealed that proneural gene activities are context-dependent and tightly regulated. Here we review how proneural bHLH TFs are regulated, with a focus on the murine cerebral cortex, drawing parallels where appropriate to other organisms and neural tissues. We discuss upstream regulatory events, post-translational modifications (phosphorylation, ubiquitinylation), protein-protein interactions, epigenetic and metabolic mechanisms that govern bHLH TF expression, stability, localization, and consequent transactivation of downstream target genes. These tight regulatory controls help to explain paradoxical findings of changes to bHLH activity in different cellular contexts.
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Affiliation(s)
- Ana-Maria Oproescu
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Sisu Han
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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24
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Harris L, Rigo P, Stiehl T, Gaber ZB, Austin SHL, Masdeu MDM, Edwards A, Urbán N, Marciniak-Czochra A, Guillemot F. Coordinated changes in cellular behavior ensure the lifelong maintenance of the hippocampal stem cell population. Cell Stem Cell 2021; 28:863-876.e6. [PMID: 33581058 PMCID: PMC8110946 DOI: 10.1016/j.stem.2021.01.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 10/09/2020] [Accepted: 01/07/2021] [Indexed: 12/12/2022]
Abstract
Neural stem cell numbers fall rapidly in the hippocampus of juvenile mice but stabilize during adulthood, ensuring lifelong hippocampal neurogenesis. We show that this stabilization of stem cell numbers in young adults is the result of coordinated changes in stem cell behavior. Although proliferating neural stem cells in juveniles differentiate rapidly, they increasingly return to a resting state of shallow quiescence and progress through additional self-renewing divisions in adulthood. Single-cell transcriptomics, modeling, and label retention analyses indicate that resting cells have a higher activation rate and greater contribution to neurogenesis than dormant cells, which have not left quiescence. These changes in stem cell behavior result from a progressive reduction in expression of the pro-activation protein ASCL1 because of increased post-translational degradation. These cellular mechanisms help reconcile current contradictory models of hippocampal neural stem cell (NSC) dynamics and may contribute to the different rates of decline of hippocampal neurogenesis in mammalian species, including humans. More proliferating hippocampal stem cells return to shallow quiescence with age Dormant stem cells enter deeper quiescence with age These changes drive the transition from developmental to adult neurogenesis Increasing degradation of ASCL1 protein by HUWE1 coordinates these changes
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Affiliation(s)
- Lachlan Harris
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Piero Rigo
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Thomas Stiehl
- Institute of Applied Mathematics, Heidelberg University, 69120 Heidelberg, Germany; Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, 69120 Heidelberg, Germany; Bioquant Center, Heidelberg University, 69120 Heidelberg, Germany
| | - Zachary B Gaber
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Sophie H L Austin
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Maria Del Mar Masdeu
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Amelia Edwards
- Advanced Sequencing Facility, The Francis Crick Institute, London NW1 1AT, UK
| | - Noelia Urbán
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Anna Marciniak-Czochra
- Institute of Applied Mathematics, Heidelberg University, 69120 Heidelberg, Germany; Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, 69120 Heidelberg, Germany; Bioquant Center, Heidelberg University, 69120 Heidelberg, Germany
| | - François Guillemot
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
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25
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Wang J, He Q, Zhang K, Sun H, Zhang G, Liang H, Guo J, Hao L, Ke J, Chen S. Quick Commitment and Efficient Reprogramming Route of Direct Induction of Retinal Ganglion Cell-like Neurons. Stem Cell Reports 2020; 15:1095-1110. [PMID: 33096050 PMCID: PMC7663790 DOI: 10.1016/j.stemcr.2020.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 09/22/2020] [Accepted: 09/22/2020] [Indexed: 01/16/2023] Open
Abstract
Direct reprogramming has been widely explored to generate various types of neurons for neurobiological research and translational medicine applications, but there is still no efficient reprogramming method to generate retinal ganglion cell (RGC)-like neurons, which are the sole projection neurons in the retina. Here, we show that three transcription factors, Ascl1, Brn3b, and Isl1, efficiently convert fibroblasts into RGC-like neurons (iRGCs). Furthermore, we show that the competence of cells to enter iRGC reprogramming route is determined by the cell-cycle status at a very early stage of the process. The iRGC reprogramming route involves intermediate states that are characterized by a transient inflammatory-like response followed by active epigenomic and transcriptional modifications. Our study provides an efficient method to generate iRGCs, which would be a valuable cell source for potential glaucoma cell replacement therapy and drug screening studies, and reveals the key cellular events that govern successful neuronal fate reprogramming.
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Affiliation(s)
- Jing Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Qinghai He
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Ke Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Hui Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Gong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Huilin Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Jingyi Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Lili Hao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Jiangbin Ke
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China
| | - Shuyi Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510623, China.
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26
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Aslanpour S, Rosin JM, Balakrishnan A, Klenin N, Blot F, Gradwohl G, Schuurmans C, Kurrasch DM. Ascl1 is required to specify a subset of ventromedial hypothalamic neurons. Development 2020; 147:dev180067. [PMID: 32253239 DOI: 10.1242/dev.180067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 03/23/2020] [Indexed: 03/01/2024]
Abstract
Despite clear physiological roles, the ventromedial hypothalamus (VMH) developmental programs are poorly understood. Here, we asked whether the proneural gene achaete-scute homolog 1 (Ascl1) contributes to VMH development. Ascl1 transcripts were detected in embryonic day (E) 10.5 to postnatal day 0 VMH neural progenitors. The elimination of Ascl1 reduced the number of VMH neurons at E12.5 and E15.5, particularly within the VMH-central (VMHC) and -dorsomedial (VMHDM) subdomains, and resulted in a VMH cell fate change from glutamatergic to GABAergic. We observed a loss of Neurog3 expression in Ascl1-/- hypothalamic progenitors and an upregulation of Neurog3 when Ascl1 was overexpressed. We also demonstrated a glutamatergic to GABAergic fate switch in Neurog3-null mutant mice, suggesting that Ascl1 might act via Neurog3 to drive VMH cell fate decisions. We also showed a concomitant increase in expression of the central GABAergic fate determinant Dlx1/2 in the Ascl1-null hypothalamus. However, Ascl1 was not sufficient to induce an ectopic VMH fate when overexpressed outside the normal window of competency. Combined, Ascl1 is required but not sufficient to specify the neurotransmitter identity of VMH neurons, acting in a transcriptional cascade with Neurog3.
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Affiliation(s)
- Shaghayegh Aslanpour
- Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jessica M Rosin
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Anjali Balakrishnan
- Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, ON M4N 3M5, Canada
| | - Natalia Klenin
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Florence Blot
- Department of Development and Stem Cells, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM, Universite de Strasbourg, Illkirch 67400, France
| | - Gerard Gradwohl
- Department of Development and Stem Cells, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM, Universite de Strasbourg, Illkirch 67400, France
| | - Carol Schuurmans
- Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, ON M4N 3M5, Canada
| | - Deborah M Kurrasch
- Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
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27
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Jorstad NL, Wilken MS, Todd L, Finkbeiner C, Nakamura P, Radulovich N, Hooper MJ, Chitsazan A, Wilkerson BA, Rieke F, Reh TA. STAT Signaling Modifies Ascl1 Chromatin Binding and Limits Neural Regeneration from Muller Glia in Adult Mouse Retina. Cell Rep 2020; 30:2195-2208.e5. [PMID: 32075759 PMCID: PMC7148114 DOI: 10.1016/j.celrep.2020.01.075] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 12/09/2019] [Accepted: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
Müller glia (MG) serve as sources for retinal regeneration in non-mammalian vertebrates. We find that this process can be induced in mouse MG, after injury, by transgenic expression of the proneural transcription factor Ascl1 and the HDAC inhibitor TSA. However, new neurons are generated only from a subset of MG. Identifying factors that limit Ascl1-mediated MG reprogramming could make this process more efficient. In this study, we test whether injury-induced STAT activation hampers the ability of Ascl1 to reprogram MG into retinal neurons. Single-cell RNA-seq shows that progenitor-like cells derived from Ascl1-expressing MG have a higher level of STAT signaling than do those cells that become neurons. Ascl1-ChIPseq and ATAC-seq show that STAT potentially directs Ascl1 to developmentally inappropriate targets. Using a STAT inhibitor, in combination with our previously described reprogramming paradigm, we found a large increase in the ability of MG to generate neurons.
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Affiliation(s)
- Nikolas L Jorstad
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA; Department of Pathology, Molecular Medicine and Mechanisms of Disease Program, University of Washington, Seattle, WA 98195, USA
| | - Matthew S Wilken
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Levi Todd
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Connor Finkbeiner
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Paul Nakamura
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Nicholas Radulovich
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Marcus J Hooper
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Alex Chitsazan
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Brent A Wilkerson
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA.
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28
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Wohl SG, Hooper MJ, Reh TA. MicroRNAs miR-25, let-7 and miR-124 regulate the neurogenic potential of Müller glia in mice. Development 2019; 146:dev179556. [PMID: 31383796 PMCID: PMC6765125 DOI: 10.1242/dev.179556] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/24/2019] [Indexed: 12/21/2022]
Abstract
Müller glial cells (MG) generate retinal progenitor (RPC)-like cells after injury in non-mammalian species, although this does not occur in the mammalian retina. Studies have profiled gene expression in these cells to define genes that may be relevant to their differences in neurogenic potential. However, less is known about differences in micro-RNA (miRNA) expression. In this study, we compared miRNAs from RPCs and MG to identify miRNAs more highly expressed in RPCs, and others more highly expressed in MG. To determine whether these miRNAs are relevant to the difference in neurogenic potential between these two cell types, we tested them in dissociated cultures of MG using either mimics or antagomiRs to increase or reduce expression, respectively. Among the miRNAs tested, miR-25 and miR-124 overexpression, or let-7 antagonism, induced Ascl1 expression and conversion of ∼40% of mature MG into a neuronal/RPC phenotype. Our results suggest that the differences in miRNA expression between MG and RPCs contribute to their difference in neurogenic potential, and that manipulations in miRNAs provide a new tool with which to reprogram MG for retinal regeneration.
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Affiliation(s)
- Stefanie G Wohl
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, WA 98195, USA
- Department of Biological and Vision Sciences, The State University of New York, College of Optometry, New York, NY 10036, USA
| | - Marcus J Hooper
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, WA 98195, USA
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, WA 98195, USA
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29
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Raina A, Mahajani S, Bähr M, Kügler S. Neuronal Trans-differentiation by Transcription Factors Ascl1 and Nurr1: Induction of a Dopaminergic Neurotransmitter Phenotype in Cortical GABAergic Neurons. Mol Neurobiol 2019; 57:249-260. [PMID: 31317490 DOI: 10.1007/s12035-019-01701-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 07/09/2019] [Indexed: 12/17/2022]
Abstract
Neurons with a desired neurotransmitter phenotype can be differentiated from induced pluripotent stem cells or from somatic cells only through tedious protocols with relatively low yield. Readily available cortical neurons isolated from embryonic rat brain, which have already undergone a complete neuronal differentiation process, might serve as alternative template source. These cultures consist of 85% glutamatergic and 15% GABAergic neurons, and we attempted to trans-differentiate them into dopaminergic neurons. Transcription factors Nurr1, Lmx1A and Pitx3, essential determinants of a dopaminergic cell fate during CNS development, were not sufficient to induce tyrosine hydroxylase expression in a significant number of cells. Combining Nurr1 with the generic neuronal differentiator and re-programming factor Ascl1, however, resulted in generation of neurons which express dopaminergic markers TH, AADC, VMAT2 and DAT. Only neurons of GABAergic phenotype could be trans-differentiated towards a dopaminergic neurotransmitter phenotype, while for glutamatergic neurons, this process proved to be neurotoxic. Intriguingly, GABAergic neurons isolated from embryonal midbrain could not be trans-differentiated into dopaminergic neurons by Ascl1 and Nurr1. Thus, in principle, post-mitotic embryonal neurons can serve as templates for neurons with a desired neurotransmitter phenotype. However, neurotransmitter phenotype plasticity critically depends on the differentiation history of the template neurons, which can result in relatively low yields of dopaminergic neurons.
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Affiliation(s)
- Anupam Raina
- Department of Neurology, University Medicine Göttingen, Waldweg 33, 37073, Göttingen, Germany.,Center Nanoscale Microscopy and Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Sameehan Mahajani
- Department of Neurology, University Medicine Göttingen, Waldweg 33, 37073, Göttingen, Germany.,Center Nanoscale Microscopy and Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medicine Göttingen, Waldweg 33, 37073, Göttingen, Germany.,Center Nanoscale Microscopy and Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Sebastian Kügler
- Department of Neurology, University Medicine Göttingen, Waldweg 33, 37073, Göttingen, Germany. .,Center Nanoscale Microscopy and Physiology of the Brain (CNMPB), Göttingen, Germany.
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30
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Abstract
Adult neural stem cells are mostly quiescent and only rarely enter the cell cycle to self-renew and generate neuronal or glial progenies. The Notch signaling pathway is essential for both the quiescent and proliferative states of neural stem cells. However, these are mutually exclusive cellular states; thus, how Notch promotes both of these programs within adult neural stem cells has remained unclear. In this issue of Genes & Development, Sueda and colleagues (pp. 511-523) use an extensive repertoire of mouse genetic tools and techniques to demonstrate that it is the levels and dynamic expression of the Notch transcriptional effector Hairy and Enhancer of Split 1 that enables this dual role.
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Affiliation(s)
- Lachlan Harris
- The Francis Crick Institute, London NW1 1AT, United Kingdom
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31
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Fernandez Garcia M, Moore CD, Schulz KN, Alberto O, Donague G, Harrison MM, Zhu H, Zaret KS. Structural Features of Transcription Factors Associating with Nucleosome Binding. Mol Cell 2019; 75:921-932.e6. [PMID: 31303471 DOI: 10.1016/j.molcel.2019.06.009] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/01/2019] [Accepted: 06/07/2019] [Indexed: 10/26/2022]
Abstract
Fate-changing transcription factors (TFs) scan chromatin to initiate new genetic programs during cell differentiation and reprogramming. Yet the protein structure domains that allow TFs to target nucleosomal DNA remain unexplored. We screened diverse TFs for binding to nucleosomes containing motif-enriched sequences targeted by pioneer factors in vivo. FOXA1, OCT4, ASCL1/E12α, PU1, CEBPα, and ZELDA display a range of nucleosome binding affinities that correlate with their cell reprogramming potential. We further screened 593 full-length human TFs on protein microarrays against different nucleosome sequences, followed by confirmation in solution, to distinguish among factors that bound nucleosomes, such as the neuronal AP-2α/β/γ, versus factors that only bound free DNA. Structural comparisons of DNA binding domains revealed that efficient nucleosome binders use short anchoring α helices to bind DNA, whereas weak nucleosome binders use unstructured regions and/or β sheets. Thus, specific modes of DNA interaction allow nucleosome scanning that confers pioneer activity to transcription factors.
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Affiliation(s)
- Meilin Fernandez Garcia
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-5157, USA
| | - Cedric D Moore
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Katharine N Schulz
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI 53706, USA
| | - Oscar Alberto
- Institute for Regenerative Medicine, Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-5157, USA
| | - Greg Donague
- Institute for Regenerative Medicine, Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-5157, USA
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI 53706, USA
| | - Heng Zhu
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kenneth S Zaret
- Institute for Regenerative Medicine, Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-5157, USA.
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32
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Sueda R, Imayoshi I, Harima Y, Kageyama R. High Hes1 expression and resultant Ascl1 suppression regulate quiescent vs. active neural stem cells in the adult mouse brain. Genes Dev 2019; 33:511-523. [PMID: 30862661 PMCID: PMC6499325 DOI: 10.1101/gad.323196.118] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/26/2019] [Indexed: 01/03/2023]
Abstract
Sueda et al. show that in quiescent neural stem cells, Hes1 levels are oscillatory, although the peaks and troughs are higher than those in active neural stem cells, causing Ascl1 expression to be continuously suppressed. Somatic stem/progenitor cells are active in embryonic tissues but quiescent in many adult tissues. The detailed mechanisms that regulate active versus quiescent stem cell states are largely unknown. In active neural stem cells, Hes1 expression oscillates and drives cyclic expression of the proneural gene Ascl1, which activates cell proliferation. Here, we found that in quiescent neural stem cells in the adult mouse brain, Hes1 levels are oscillatory, although the peaks and troughs are higher than those in active neural stem cells, causing Ascl1 expression to be continuously suppressed. Inactivation of Hes1 and its related genes up-regulates Ascl1 expression and increases neurogenesis. This causes rapid depletion of neural stem cells and premature termination of neurogenesis. Conversely, sustained Hes1 expression represses Ascl1, inhibits neurogenesis, and maintains quiescent neural stem cells. In contrast, induction of Ascl1 oscillations activates neural stem cells and increases neurogenesis in the adult mouse brain. Thus, Ascl1 oscillations, which normally depend on Hes1 oscillations, regulate the active state, while high Hes1 expression and resultant Ascl1 suppression promote quiescence in neural stem cells.
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Affiliation(s)
- Risa Sueda
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Itaru Imayoshi
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.,Research Center for Dynamic Living Systems, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan.,Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501, Japan
| | - Yukiko Harima
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Ryoichiro Kageyama
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.,Research Center for Dynamic Living Systems, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.,Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501, Japan.,Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
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33
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Rajakulendran N, Rowland KJ, Selvadurai HJ, Ahmadi M, Park NI, Naumenko S, Dolma S, Ward RJ, So M, Lee L, MacLeod G, Pasiliao C, Brandon C, Clarke ID, Cusimano MD, Bernstein M, Batada N, Angers S, Dirks PB. Wnt and Notch signaling govern self-renewal and differentiation in a subset of human glioblastoma stem cells. Genes Dev 2019; 33:498-510. [PMID: 30842215 PMCID: PMC6499328 DOI: 10.1101/gad.321968.118] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/19/2019] [Indexed: 01/10/2023]
Abstract
In this study, Rajakulendran et al. investigated the role of Wnt/βcatenin signaling in GBM stem cell renewal and fate decisions. They identify new contexts for Wnt modulation for targeting stem cell differentiation and self-renewal in GBM heterogeneity. Developmental signal transduction pathways act diversely, with context-dependent roles across systems and disease types. Glioblastomas (GBMs), which are the poorest prognosis primary brain cancers, strongly resemble developmental systems, but these growth processes have not been exploited therapeutically, likely in part due to the extreme cellular and genetic heterogeneity observed in these tumors. The role of Wnt/βcatenin signaling in GBM stem cell (GSC) renewal and fate decisions remains controversial. Here, we report context-specific actions of Wnt/βcatenin signaling in directing cellular fate specification and renewal. A subset of primary GBM-derived stem cells requires Wnt proteins for self-renewal, and this subset specifically relies on Wnt/βcatenin signaling for enhanced tumor burden in xenograft models. In an orthotopic Wnt reporter model, Wnthi GBM cells (which exhibit high levels of βcatenin signaling) are a faster-cycling, highly self-renewing stem cell pool. In contrast, Wntlo cells (with low levels of signaling) are slower cycling and have decreased self-renewing potential. Dual inhibition of Wnt/βcatenin and Notch signaling in GSCs that express high levels of the proneural transcription factor ASCL1 leads to robust neuronal differentiation and inhibits clonogenic potential. Our work identifies new contexts for Wnt modulation for targeting stem cell differentiation and self-renewal in GBM heterogeneity, which deserve further exploration therapeutically.
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Affiliation(s)
- Nishani Rajakulendran
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Katherine J Rowland
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Hayden J Selvadurai
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Moloud Ahmadi
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Nicole I Park
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Faculty of Medicine, Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 0A4, Canada
| | - Sergey Naumenko
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada
| | - Sonam Dolma
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Ryan J Ward
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Milly So
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Lilian Lee
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Graham MacLeod
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Clarissa Pasiliao
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Faculty of Medicine, Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 0A4, Canada
| | - Caroline Brandon
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Ian D Clarke
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Michael D Cusimano
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada
| | - Mark Bernstein
- Toronto Western Hospital, Toronto, Ontario M5T 2S8, Canada
| | - Nizar Batada
- Institute of Genetics and Molecular Medicine, Edinburgh EH4 2XU, United Kingdom
| | - Stephane Angers
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada.,Faculty of Medicine, Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Peter B Dirks
- Developmental and Stem Cell Biology Program, Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Faculty of Medicine, Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 0A4, Canada.,Faculty of Medicine, Department of Surgery, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Division of Neurosurgery The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
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34
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Dong ZY, Pei Z, Wang YL, Li Z, Khan A, Meng XT. Ascl1 Regulates Electric Field-Induced Neuronal Differentiation Through PI3K/Akt Pathway. Neuroscience 2019; 404:141-152. [PMID: 30771509 DOI: 10.1016/j.neuroscience.2019.02.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 12/14/2022]
Abstract
Directing differentiation of neural stem/progenitor cells (NSCs/NPCs) to produce functional neurons is one of the greatest challenges in regenerative medicine. Our previous paper has confirmed that electrical stimulation has a high efficiency of triggering neuronal differentiation by using isolated filum terminale (FT)-derived NPCs. To further clarify the intrinsic molecular mechanisms, protein-protein interaction (PPI) network analysis was applied to pinpoints novel hubs in electric field (EF)-induced neuronal differentiation. In this study, siRNA transfection of Achaete-scute homolog 1 (Ascl1) in NPCs or NPCs was followed by direct current stimulation at 150 mV/mm. Neuronal differentiation rate and protein expression level were analyzed after 7 or 14 days of electrical stimulation. The data showed that the expression level of Ascl1 was enhanced by electrical stimulation and positively correlated to EF strength. Moreover, we identified that the expression of Ascl1 positively regulated neuronal differentiation of NPCs and can be up-regulated by EF-stimulation through the activation of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway. Therefore, this study provides new insights into the role of Ascl1 and its relevant PI3K/Akt pathway in regulating of EF-induced neuronal differentiation and pointed out that continuous expression of Ascl1 in NPCs is required for EF-induced neuronal differentiation.
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Affiliation(s)
- Zhi-Yong Dong
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun 130021, PR China.
| | - Zhe Pei
- Department of Neuroscience and Pediatric, GSRB1 Duke University, Durham 27710, USA
| | - Yan-Ling Wang
- Laboratory Teaching Center of Basic Medicine, College of Basic Medical Sciences, Jilin University, Changchun 130021, PR China.
| | - Zhe Li
- Laboratory Teaching Center of Basic Medicine, College of Basic Medical Sciences, Jilin University, Changchun 130021, PR China.
| | - Amber Khan
- The Graduate Center and CUNY School of Medicine, CUNY, 85 St Nicholas Terrace, New York, NY 10027, USA.
| | - Xiao-Ting Meng
- Department of Histology & Embryology, College of Basic Medical Sciences, Jilin University, Changchun 130021, PR China.
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35
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Abstract
Differentiation of human fibroblasts into functional neurons depends on the introduction of viral-mediated transcription factors, which present risks of viral gene integration and tumorigenicity. In recent years, although some studies have been successful in directly inducing neurons through sustained expression of small molecule compounds, they have only been shown to be effective on mouse-derived cells. Thus, herein we delivered vectors containing Epstein-Barr virus-derived oriP/Epstein-Barr nuclear antigen 1 encoding the neuronal transcription factor, Ascl1, the neuron-specific microRNA, miR124, and a small hairpin directed against p53, into human fibroblasts. Cells were incubated in a neuron-inducing culture medium. Immunofluorescence staining was used to detect Tuj-1, microtubule-associated protein 2, neuron-specific nucleoprotein NeuN and nerve cell adhesion molecules in the induced cells. The proportion of Tuj1-positive cells was up to 36.7% after induction for 11 days. From day 21, these induced neurons showed neuron-specific expression patterns of microtubule-associated protein 2, NeuN and neural cell adhesion molecule. Our approach is a simple, plasmid-based process that enables direct reprogramming of human fibroblasts into neurons, and provides alternative avenues for disease modeling and neurodegenerative medicine.
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Affiliation(s)
- Shao-Bing Dai
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Ting Shen
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Ting-Ting Zheng
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jia-Li Pu
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Xin-Zhong Chen
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
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36
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Gotoh H, Wood WM, Patel KD, Factor DC, Boshans LL, Nomura T, Tesar PJ, Ono K, Nishiyama A. NG2 expression in NG2 glia is regulated by binding of SoxE and bHLH transcription factors to a Cspg4 intronic enhancer. Glia 2018; 66:2684-2699. [PMID: 30306660 PMCID: PMC6309483 DOI: 10.1002/glia.23521] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 07/27/2018] [Accepted: 08/03/2018] [Indexed: 11/08/2022]
Abstract
NG2 is a type 1 integral membrane glycoprotein encoded by the Cspg4 gene. It is expressed on glial progenitor cells known as NG2 glial cells or oligodendrocyte precursor cells that exist widely throughout the developing and mature central nervous system and vascular mural cells but not on mature oligodendrocytes, astrocytes, microglia, neurons, or neural stem cells. Hence NG2 is widely used as a marker for NG2 glia in the rodent and human. The regulatory elements of the mouse Cspg4 gene and its flanking sequences have been used successfully to target reporter and Cre recombinase to NG2 glia in transgenic mice when used in a large 200 kb bacterial artificial chromosome cassette containing the 38 kb Cspg4 gene in the center. Despite the tightly regulated cell type- and stage-specific expression of NG2 in the brain and spinal cord, the mechanisms that regulate its transcription have remained unknown. Here, we describe a 1.45 kb intronic enhancer of the mouse Cspg4 gene that directed transcription of EGFP reporter to NG2 glia but not to pericytes in vitro and in transgenic mice. The 1.45 kb enhancer contained binding sites for SoxE and basic helix-loop-helix transcription factors, and its enhancer activity was augmented cooperatively by these factors, whose respective binding elements were found in close proximity to each other. Mutations in these binding elements abrogated the enhancer activity when tested in the postnatal mouse brain.
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Affiliation(s)
- Hitoshi Gotoh
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269-3156, USA
- Department of Biology, Kyoto Prefectural University of Medicine, Kyoto, 606-0823, Japan
| | - William M. Wood
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269-3156, USA
| | - Kiran D. Patel
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269-3156, USA
| | - Daniel C. Factor
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland OH, 44106, USA
| | - Linda L. Boshans
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269-3156, USA
| | - Tadashi Nomura
- Department of Biology, Kyoto Prefectural University of Medicine, Kyoto, 606-0823, Japan
| | - Paul J. Tesar
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland OH, 44106, USA
- Department of Neurosciences, Case Western Reserve University School of Medicine
| | - Katsuhiko Ono
- Department of Biology, Kyoto Prefectural University of Medicine, Kyoto, 606-0823, Japan
| | - Akiko Nishiyama
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269-3156, USA
- Institute of Systems Genomics, University of Connecticut
- Institute of Brain and Cognitive Science, University of Connecticut
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37
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Guimarães RPDM, Landeira BS, Coelho DM, Golbert DCF, Silveira MS, Linden R, de Melo Reis RA, Costa MR. Evidence of Müller Glia Conversion Into Retina Ganglion Cells Using Neurogenin2. Front Cell Neurosci 2018; 12:410. [PMID: 30483060 PMCID: PMC6240664 DOI: 10.3389/fncel.2018.00410] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 10/22/2018] [Indexed: 01/09/2023] Open
Abstract
Degenerative retinopathies are the leading causes of irreversible visual impairment in the elderly, affecting hundreds of millions of patients. Müller glia cells (MGC), the main type of glia found in the vertebrate retina, can resume proliferation in the rodent adult injured retina but contribute weakly to tissue repair when compared to zebrafish retina. However, postnatal and adult mouse MGC can be genetically reprogrammed through the expression of the transcription factor (TF) Achaete-scute homolog 1 (ASCL1) into induced neurons (iNs), displaying key hallmarks of photoreceptors, bipolar and amacrine cells, which may contribute to regenerate the damaged retina. Here, we show that the TF neurogenin 2 (NEUROG2) is also sufficient to lineage-reprogram postnatal mouse MGC into iNs. The efficiency of MGC lineage conversion by NEUROG2 is similar to that observed after expression of ASCL1 and both TFs induce the generation of functionally active iNs. Treatment of MGC cultures with EGF and FGF2 prior to Neurog2 or Ascl1 expression enhances reprogramming efficiencies, what can be at least partially explained by an increase in the frequency of MGCs expressing sex determining region Y (SRY)-box 2 (SOX2). Transduction of either Neurog2 or Ascl1 led to the upregulation of key retina neuronal genes in MGC-derived iNs, but only NEUROG2 induced a consistent increase in the expression of putative retinal ganglion cell (RGC) genes. Moreover, in vivo electroporation of Neurog2 in late progenitors from the neonatal rat retina, which are transcriptionally similar to MGCs, also induced a shift in the generation of retinal cell subtypes, favoring neuronal differentiation at the expense of MGCs and resuming the generation of RGCs. Altogether, our data indicate that NEUROG2 induces lineage conversion of postnatal rodent MGCs into RGC-like iNs in vitro and resumes the generation of this neuronal type from late progenitors of the retina in vivo.
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Affiliation(s)
- Roberta Pereira de Melo Guimarães
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil.,Lab Neurogenesis, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Lab Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Diego Marques Coelho
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil.,Bioinformatics Multidisciplinary Environment, IMD, Federal University of Rio Grande do Norte, Rio de Janeiro, Brazil
| | | | - Mariana S Silveira
- Lab Neurogenesis, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael Linden
- Lab Neurogenesis, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ricardo A de Melo Reis
- Lab Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcos R Costa
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
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38
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Abstract
From the relatively simple nervous system of Drosophila to the elaborate mammalian cortex, neurogenesis requires exceptional spatial and temporal precision to co-ordinate progenitor cell proliferation and subsequent differentiation to a diverse range of neurons and glia. A limited number of transiently expressed proneural basic-helix-loop-helix (bHLH) transcription factors, for example achaete-scute-complex (as-c) and atonal (ato) in Drosophila and the vertebrate homologues Ascl1 and Neurogenin2 (Ngn2), are able to orchestrate the onset of neuronal determination, context-dependent subtype selection and even influence later aspects of neuronal migration and maturation. Within the last decade, two models have emerged to explain how the temporal activity of proneural determination factors is regulated by phosphorylation at distinct sites. One model describes how cell-cycle associated phosphorylation on multiple sites in the N and C termini of vertebrate proneural proteins limits neuronal differentiation in cycling progenitor cells. A second model describes phosphorylation on a single site in the bHLH domain of Drosophila atonal that acts as a binary switch, where phosphorylation terminates proneural activity. Here we combine activating mutations of phosphorylation sites in the N- and C- termini with an inhibitory phospho-mimetic mutation in the bHLH domain of Ascl1 and Ngn2 proteins, and test their functions in vivo using Xenopus embryos to determine which mode of phospho-regulation dominates. Enhancing activity by preventing N- and C terminal phosphorylation cannot overcome the inhibitory effect of mimicking phosphorylation of the bHLH domain. Thus we have established a hierarchy between these two modes of proneural protein control and suggest a model of temporal regulation for proneural protein activity.
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Affiliation(s)
- Laura J.A. Hardwick
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
- Department of Oncology, University of Cambridge, Cambridge, CB2 0XZ, UK
- Peterhouse, University of Cambridge, Cambridge, CB2 1RD, UK
| | - Anna Philpott
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
- Department of Oncology, University of Cambridge, Cambridge, CB2 0XZ, UK
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39
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Abstract
The proneural basic-helix-loop-helix (bHLH) transcription factor Ascl1 is a master regulator of neurogenesis in both central and peripheral nervous systems in vivo, and is a central driver of neuronal reprogramming in vitro. Over the last three decades, assaying primary neuron formation in Xenopus embryos in response to transcription factor overexpression has contributed to our understanding of the roles and regulation of proneural proteins like Ascl1, with homologues from different species usually exhibiting similar functional effects. Here we demonstrate that the mouse Ascl1 protein is twice as active as the Xenopus protein in inducing neural-β-tubulin expression in Xenopus embryos, despite there being little difference in protein accumulation or ability to undergo phosphorylation, two properties known to influence Ascl1 function. This superior activity of the mouse compared to the Xenopus protein is dependent on the presence of the non-conserved N terminal region of the protein, and indicates species-specific regulation that may necessitate care when interpreting results in cross-species experiments.
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Affiliation(s)
- Laura J.A. Hardwick
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
- Department of Oncology, University of Cambridge, Cambridge, CB2 0XZ, UK
- Peterhouse, University of Cambridge, Cambridge, CB2 1RD, UK
| | - Anna Philpott
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
- Department of Oncology, University of Cambridge, Cambridge, CB2 0XZ, UK
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Wapinski OL, Lee QY, Chen AC, Li R, Corces MR, Ang CE, Treutlein B, Xiang C, Baubet V, Suchy FP, Sankar V, Sim S, Quake SR, Dahmane N, Wernig M, Chang HY. Rapid Chromatin Switch in the Direct Reprogramming of Fibroblasts to Neurons. Cell Rep 2017; 20:3236-47. [PMID: 28954238 DOI: 10.1016/j.celrep.2017.09.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 07/18/2017] [Accepted: 09/03/2017] [Indexed: 12/16/2022] Open
Abstract
How transcription factors (TFs) reprogram one cell lineage to another remains unclear. Here, we define chromatin accessibility changes induced by the proneural TF Ascl1 throughout conversion of fibroblasts into induced neuronal (iN) cells. Thousands of genomic loci are affected as early as 12 hr after Ascl1 induction. Surprisingly, over 80% of the accessibility changes occur between days 2 and 5 of the 3-week reprogramming process. This chromatin switch coincides with robust activation of endogenous neuronal TFs and nucleosome phasing of neuronal promoters and enhancers. Subsequent morphological and functional maturation of iN cells is accomplished with relatively little chromatin reconfiguration. By integrating chromatin accessibility and transcriptome changes, we built a network model of dynamic TF regulation during iN cell reprogramming and identified Zfp238, Sox8, and Dlx3 as key TFs downstream of Ascl1. These results reveal a singular, coordinated epigenomic switch during direct reprogramming, in contrast to stepwise cell fate transitions in development.
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41
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Lisi V, Singh B, Giroux M, Guzman E, Painter MW, Cheng YC, Huebner E, Coppola G, Costigan M, Woolf CJ, Kosik KS. Enhanced Neuronal Regeneration in the CAST/Ei Mouse Strain Is Linked to Expression of Differentiation Markers after Injury. Cell Rep 2018; 20:1136-1147. [PMID: 28768198 DOI: 10.1016/j.celrep.2017.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/19/2017] [Accepted: 07/06/2017] [Indexed: 12/21/2022] Open
Abstract
Peripheral nerve regeneration after injury requires a broad program of transcriptional changes. We investigated the basis for the enhanced nerve regenerative capacity of the CAST/Ei mouse strain relative to C57BL/6 mice. RNA sequencing of dorsal root ganglia (DRG) showed a CAST/Ei-specific upregulation of Ascl1 after injury. Ascl1 overexpression in DRG neurons of C57BL/6 mice enhanced their neurite outgrowth. Ascl1 is regulated by miR-7048-3p, which is downregulated in CAST/Ei mice. Inhibition of miR-7048-3p enhances neurite outgrowth. Following injury, CAST/Ei neurons largely retained their mature neuronal profile as determined by single-cell RNA- seq, whereas the C57BL/6 neurons acquired an immature profile. These findings suggest that one facet of the enhanced regenerative phenotype is preservation of neuronal identity in response to injury.
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Affiliation(s)
- Véronique Lisi
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Bhagat Singh
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Michel Giroux
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Elmer Guzman
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Michio W Painter
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Yung-Chih Cheng
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Eric Huebner
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Giovanni Coppola
- Departments of Psychiatry and Neurology, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael Costigan
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; Anaesthesia Department, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Kenneth S Kosik
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
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42
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Chouchane M, Costa MR. Instructing neuronal identity during CNS development and astroglial-lineage reprogramming: Roles of NEUROG2 and ASCL1. Brain Res 2018; 1705:66-74. [PMID: 29510143 DOI: 10.1016/j.brainres.2018.02.045] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/16/2018] [Accepted: 02/27/2018] [Indexed: 01/02/2023]
Abstract
The adult mammalian brain contains an enormous variety of neuronal types, which are generally categorized in large groups, based on their neurochemical identity, hodological properties and molecular markers. This broad classification has allowed the correlation between individual neural progenitor populations and their neuronal progeny, thus contributing to probe the cellular and molecular mechanisms involved in neuronal identity determination during central nervous system (CNS) development. In this review, we discuss the contribution of the proneural genes Neurogenin2 (Neurog2) and Achaete-scute homolog 1 (Ascl1) for the specification of neuronal phenotypes in the developing neocortex, cerebellum and retina. Then, we revise recent data on astroglia cell lineage reprogramming into induced neurons using the same proneural proteins to compare the neuronal phenotypes obtained from astroglial cells originated in those CNS regions. We conclude that Ascl1 and Neurog2 have different contributions to determine neuronal fates, depending on the neural progenitor or astroglial population expressing those proneural factors. Finally, we discuss some possible explanations for these seemingly conflicting effects of Ascl1 and Neurog2 and propose future approaches to further dissect the molecular mechanisms of neuronal identity specification.
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Affiliation(s)
- Malek Chouchane
- Brain Institute, Federal University of Rio Grande do Norte, Natal 59072-970, Brazil; Neurological Surgery Department, University of California, San Francisco 94158, USA
| | - Marcos R Costa
- Brain Institute, Federal University of Rio Grande do Norte, Natal 59072-970, Brazil.
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43
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Chen C, Breslin MB, Lan MS. Sonic hedgehog signaling pathway promotes INSM1 transcription factor in neuroendocrine lung cancer. Cell Signal 2018; 46:83-91. [PMID: 29501727 DOI: 10.1016/j.cellsig.2018.02.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/23/2018] [Accepted: 02/28/2018] [Indexed: 12/21/2022]
Abstract
Neuroendocrine (NE) lung tumors account for 20% of total lung cancer cases and represent a subset of aggressive tumors with metastatic potential. High-risk NE lung cancer patients display disseminated disease, N-myc expression/amplification, and poorly differentiated tumors. In this study, we investigate the molecular mechanisms underlying a zinc-finger transcription factor, INSM1 in NE lung cancer. Our study revealed that INSM1 crosstalk with the Shh-PI3K/AKT-N-myc/Ascl1-MEK/ERK1/2 transcriptional network in NE lung cancer. The INSM1 expression pattern and functional data demonstrated that INSM1 is not only critical for NE differentiation, but also served as a NE tumor-specific marker in small cell lung carcinoma (SCLC). The Shh signaling pathway activates INSM1 expression through N-myc and Ascl1 in aggressive SCLC. The E2-box in the INSM1 promoter is the direct target recognized by N-myc and Ascl1 transcription factors. N-myc or Ascl1 activates endogenous INSM1 expression in lung cancer cells. INSM1 functions as a key player in NE lung cancer via Shh signaling that crosstalk with PI3K/AKT and MEK/ERK1/2 pathway to enhance N-myc stability in NE lung cancer. We investigate the negative effects of Shh inhibitor and knockdown of INSM1 in NE lung cancer cells. The combination of different Shh signaling pathway inhibitors targeting INSM1 and N-myc inhibits lung cancer cell growth and could be used as a new treatment option for SCLC.
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Affiliation(s)
- Chiachen Chen
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Mary B Breslin
- Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Michael S Lan
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
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44
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Elsaeidi F, Macpherson P, Mills EA, Jui J, Flannery JG, Goldman D. Notch Suppression Collaborates with Ascl1 and Lin28 to Unleash a Regenerative Response in Fish Retina, But Not in Mice. J Neurosci 2018; 38:2246-61. [PMID: 29378863 DOI: 10.1523/JNEUROSCI.2126-17.2018] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 01/15/2018] [Accepted: 01/19/2018] [Indexed: 11/21/2022] Open
Abstract
Müller glial (MG) cells in the zebrafish retina respond to injury by acquiring retinal stem-cell characteristics. Thousands of gene expression changes are associated with this event. Key among these changes is the induction of Ascl1a and Lin28a, two reprogramming factors whose expression is necessary for retina regeneration. Whether these factors are sufficient to drive MG proliferation and subsequent neuronal-fate specification remains unknown. To test this, we conditionally expressed Ascl1a and Lin28a in the uninjured retina of male and female fish. We found that together, their forced expression only stimulates sparse MG proliferation. However, in combination with Notch signaling inhibition, widespread MG proliferation and neuron regeneration ensued. Remarkably, Ascl1 and Lin28a expression in the retina of male and female mice also stimulated sparse MG proliferation, although this was not enhanced when combined with inhibitors of Notch signaling. Lineage tracing in both fish and mice suggested that the proliferating MG generated multipotent progenitors; however, this process was much more efficient in fish than mice. Overall, our studies suggest that the overexpression of Ascl1a and Lin28a in zebrafish, in combination with inhibition of Notch signaling, can phenocopy the effects of retinal injury in Müller glia. Interestingly, Ascl1 and Lin28a seem to have similar effects in fish and mice, whereas Notch signaling may differ. Understanding the different consequences of Notch signaling inhibition in fish and mice, may suggest additional strategies for enhancing retina regeneration in mammals.SIGNIFICANCE STATEMENT Mechanisms underlying retina regeneration in fish may suggest strategies for stimulating this process in mammals. Here we report that forced expression of Ascl1 and Lin28a can stimulate sparse MG proliferation in fish and mice; however, only in fish does Notch signaling inhibition collaborate with Ascl1a and Lin28a to stimulate widespread MG proliferation in the uninjured retina. Discerning differences in Notch signaling between fish and mice MG may reveal strategies for stimulating retina regeneration in mammals.
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45
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Vasconcelos FF, Sessa A, Laranjeira C, Raposo AASF, Teixeira V, Hagey DW, Tomaz DM, Muhr J, Broccoli V, Castro DS. MyT1 Counteracts the Neural Progenitor Program to Promote Vertebrate Neurogenesis. Cell Rep 2017; 17:469-483. [PMID: 27705795 PMCID: PMC5067283 DOI: 10.1016/j.celrep.2016.09.024] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 07/12/2016] [Accepted: 09/09/2016] [Indexed: 11/30/2022] Open
Abstract
The generation of neurons from neural stem cells requires large-scale changes in gene expression that are controlled to a large extent by proneural transcription factors, such as Ascl1. While recent studies have characterized the differentiation genes activated by proneural factors, less is known on the mechanisms that suppress progenitor cell identity. Here, we show that Ascl1 induces the transcription factor MyT1 while promoting neuronal differentiation. We combined functional studies of MyT1 during neurogenesis with the characterization of its transcriptional program. MyT1 binding is associated with repression of gene transcription in neural progenitor cells. It promotes neuronal differentiation by counteracting the inhibitory activity of Notch signaling at multiple levels, targeting the Notch1 receptor and many of its downstream targets. These include regulators of the neural progenitor program, such as Hes1, Sox2, Id3, and Olig1. Thus, Ascl1 suppresses Notch signaling cell-autonomously via MyT1, coupling neuronal differentiation with repression of the progenitor fate. MyT1 promotes neurogenesis downstream Ascl1 MyT1 represses Notch1 receptor and many of its downstream target genes MyT1 represses Hes1 expression by direct DNA binding and competition with RBPJ Ascl1 suppresses Notch signaling cell-autonomously while promoting differentiation
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Affiliation(s)
| | - Alessandro Sessa
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | | | | | - Vera Teixeira
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - Daniel W Hagey
- Department of Cell and Molecular Biology, Ludwig Institute for Cancer Research, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Diogo M Tomaz
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - Jonas Muhr
- Department of Cell and Molecular Biology, Ludwig Institute for Cancer Research, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Vania Broccoli
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Diogo S Castro
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal.
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46
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Hao L, Xu Z, Sun H, Luo W, Yan Y, Wang J, Guo J, Liu Y, Chen S. Direct induction of functional neuronal cells from fibroblast-like cells derived from adult human retina. Stem Cell Res 2017; 23:61-72. [PMID: 28697461 DOI: 10.1016/j.scr.2017.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 06/16/2017] [Accepted: 06/23/2017] [Indexed: 12/21/2022] Open
Abstract
Obtaining and manipulating neuronal cells are critical for neural biology basic mechanism studies and translational applications. Recent advances in protocol development and mechanism dissections have made direct induction of neuronal cells from other somatic cells (iN) a promising strategy for such purposes. In this study, we established a protocol to expand a population of fibroblast-like cells from adult human retinal tissues, which can be reprogrammed into iNs by forced expression of neurogenic transcription factors. Interestingly, the combination of Ascl1, Brn2, Myt1l, and NeuroD1 transcription factors, which has been demonstrated to be sufficient to reprogram human embryonic and dermal fibroblasts into iNs, failed to reprogram the fibroblast-like cells from human retinas into iNs. Instead, supplementing Ascl1 with Pax6 sufficed to convert the cells into iNs, which exhibited a typical neuronal morphology, expressed neural marker genes, displayed active and passive neuronal membrane activities, and made synaptic communications with other neurons. Moreover, iNs converted from retina-derived fibroblast-like cells contained high ratios of γ-Aminobutyric acid- (GABA-) and tyrosine hydroxylase- (TH-) positive neurons. Thus, the present study proposes a protocol that makes use of discarded retinal tissues from eye banks for iN generation, and suggests that different sources of somatic cells require different iN induction recipes and may also affect the iN subtype outputs. Our study may also facilitate the future development of methods to convert resident cells in situ into retinal neurons for treating retinal degeneration disease purpose.
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Affiliation(s)
- Lili Hao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhen Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Hui Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wu Luo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Youchen Yan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jing Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jingyi Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Shuyi Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
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47
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Lee B, Yoon J, Tri Lam D, Yoon J, Baek K, Jeong Y. Identification of a conserved cis-regulatory element controlling mid-diencephalic expression of mouse Six3. Genesis 2017; 55. [PMID: 28093895 DOI: 10.1002/dvg.23017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/15/2016] [Accepted: 01/11/2017] [Indexed: 11/08/2022]
Abstract
The sine oculis homeobox protein Six3 plays pivotal roles in the development of the brain and craniofacial structures. In humans, SIX3 haploinsufficiency results in holoprosencephaly, a defect in anterior midline formation. Although much is known about the evolutionarily conserved functions of Six3, the regulatory mechanism responsible for the expression pattern of Six3 remains relatively unexplored. To understand how the transcription of Six3 is controlled during embryogenesis, we screened ∼300 kb of genomic DNA encompassing the Six3 locus for cis-acting regulatory elements capable of directing reporter gene expression to sites of Six3 transcription in transgenic mouse embryos. We identified a novel enhancer element, whose activity recapitulates endogenous Six3 expression in the ventral midbrain, pretectum, and thalamus. Cross-species comparisons revealed that this Six3 brain enhancer is functionally conserved in other vertebrates. We also showed that normal Six3 transcription in the ventral midbrain and pretectum is dependent on Ascl1, a basic helix-loop-helix proneural factor. Moreover, loss of Ascl1 resulted in downregulation of the Six3 brain enhancer activity, emphasizing its unique role in regulating Six3 expression in the developing brain.
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Affiliation(s)
- Bumwhee Lee
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, 446-701, Republic of Korea
| | - Jiyeon Yoon
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, 446-701, Republic of Korea
| | - Duc Tri Lam
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, 446-701, Republic of Korea
| | - Jaeseung Yoon
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, 446-701, Republic of Korea
| | - Kwanghee Baek
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, 446-701, Republic of Korea
| | - Yongsu Jeong
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, 446-701, Republic of Korea
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48
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Ware M, Hamdi-Rozé H, Le Friec J, David V, Dupé V. Regulation of downstream neuronal genes by proneural transcription factors during initial neurogenesis in the vertebrate brain. Neural Dev 2016; 11:22. [PMID: 27923395 PMCID: PMC5142277 DOI: 10.1186/s13064-016-0077-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/29/2016] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Neurons arise in very specific regions of the neural tube, controlled by components of the Notch signalling pathway, proneural genes, and other bHLH transcription factors. How these specific neuronal areas in the brain are generated during development is just beginning to be elucidated. Notably, the critical role of proneural genes during differentiation of the neuronal populations that give rise to the early axon scaffold in the developing brain is not understood. The regulation of their downstream effectors remains poorly defined. RESULTS This study provides the first overview of the spatiotemporal expression of proneural genes in the neuronal populations of the early axon scaffold in both chick and mouse. Overexpression studies and mutant mice have identified a number of specific neuronal genes that are targets of proneural transcription factors in these neuronal populations. CONCLUSION Together, these results improve our understanding of the molecular mechanisms involved in differentiation of the first neuronal populations in the brain.
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Affiliation(s)
- Michelle Ware
- Institut de Génétique et Développement de Rennes, Faculté de Médecine, CNRS UMR6290, Université de Rennes 1, IFR140 GFAS, 2 Avenue du Pr. Léon Bernard, 35043, Rennes Cedex, France.,Present address: Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, CB2 3DY, Cambridge, UK
| | - Houda Hamdi-Rozé
- Institut de Génétique et Développement de Rennes, Faculté de Médecine, CNRS UMR6290, Université de Rennes 1, IFR140 GFAS, 2 Avenue du Pr. Léon Bernard, 35043, Rennes Cedex, France.,Laboratoire de Génétique Moléculaire, CHU Pontchaillou, Rennes Cedex, France
| | - Julien Le Friec
- Institut de Génétique et Développement de Rennes, Faculté de Médecine, CNRS UMR6290, Université de Rennes 1, IFR140 GFAS, 2 Avenue du Pr. Léon Bernard, 35043, Rennes Cedex, France
| | - Véronique David
- Institut de Génétique et Développement de Rennes, Faculté de Médecine, CNRS UMR6290, Université de Rennes 1, IFR140 GFAS, 2 Avenue du Pr. Léon Bernard, 35043, Rennes Cedex, France.,Laboratoire de Génétique Moléculaire, CHU Pontchaillou, Rennes Cedex, France
| | - Valérie Dupé
- Institut de Génétique et Développement de Rennes, Faculté de Médecine, CNRS UMR6290, Université de Rennes 1, IFR140 GFAS, 2 Avenue du Pr. Léon Bernard, 35043, Rennes Cedex, France.
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49
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Marsters CM, Rosin JM, Thornton HF, Aslanpour S, Klenin N, Wilkinson G, Schuurmans C, Pittman QJ, Kurrasch DM. Oligodendrocyte development in the embryonic tuberal hypothalamus and the influence of Ascl1. Neural Dev 2016; 11:20. [PMID: 27863528 PMCID: PMC5116181 DOI: 10.1186/s13064-016-0075-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 11/08/2016] [Indexed: 01/28/2023] Open
Abstract
Background Although the vast majority of cells in our brains are glia, we are only beginning to understand programs governing their development, especially within the embryonic hypothalamus. In mice, gliogenesis is a protracted process that begins during embryonic stages and continues into the early postnatal period, with glial progenitors first producing oligodendrocyte precursor cells, which then differentiate into pro-oligodendrocytes, pro-myelinating oligodendrocytes, and finally, mature myelinating oligodendrocytes. The exact timing of the transition from neurogenesis to gliogenesis and the subsequent differentiation of glial lineages remains unknown for most of the Central Nervous System (CNS), and is especially true for the hypothalamus. Methods Here we used mouse embryonic brain samples to determine the onset of gliogenesis and expansion of glial populations in the tuberal hypothalamus using glial markers Sox9, Sox10, Olig2, PdgfRα, Aldh1L1, and MBP. We further employed Ascl1 and Neurog2 mutant mice to probe the influence of these proneual genes on developing embryonic gliogenic populations. Results Using marker analyses for glial precursors, we found that gliogenesis commences just prior to E13.5 in the tuberal hypothalamus, beginning with the detection of glioblast and oligodendrocyte precursor cell markers in a restricted domain adjacent to the third ventricle. Sox9+ and Olig2+ glioblasts are also observed in the mantle region from E13.5 onwards, many of which are Ki67+ proliferating cells, and peaks at E17.5. Using Ascl1 and Neurog2 mutant mice to investigate the influence of these bHLH transcription factors on the progression of gliogenesis in the tuberal hypothalamus, we found that the elimination of Ascl1 resulted in an increase in oligodendrocyte cells throughout the expansive period of oligodendrogenesis. Conclusion Our results are the first to define the timing of gliogenesis in the tuberal hypothalamus and indicate that Ascl1 is required to repress oligodendrocyte differentiation within this brain region. Electronic supplementary material The online version of this article (doi:10.1186/s13064-016-0075-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Candace M Marsters
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Department of Pharmacology & Physiology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Jessica M Rosin
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Hayley F Thornton
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Shaghayegh Aslanpour
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Natasha Klenin
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Grey Wilkinson
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Carol Schuurmans
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Quentin J Pittman
- Department of Pharmacology & Physiology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Deborah M Kurrasch
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada. .,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.
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Min Z, Lin H, Zhu X, Gao L, Khand AA, Tao Q. Ascl1 represses the mesendoderm induction in Xenopus. Acta Biochim Biophys Sin (Shanghai) 2016; 48:1006-1015. [PMID: 27624953 DOI: 10.1093/abbs/gmw092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/15/2016] [Indexed: 11/13/2022] Open
Abstract
Ascl1 is a multi-functional regulator of neural development in invertebrates and vertebrates. Ectopic expression of Ascl1 can generate functional neurons from non-neural somatic cells. The abnormal expression of ASCL1 has been reported in several types of carcinomas. We have previously identified Ascl1 as a crucial maternal regulator of the germ layer pattern formation in Xenopus Functional studies have indicated that the maternally-supplied Ascl1 renders embryonic cells a propensity to adopt neural fates on one hand, and represses the mesendoderm formation on the other. However, it remains unclear how Ascl1 achieves its repressor function during the activation of mesendoderm genes by VegT. Here, we performed series of gain- and loss-of-function experiments and found that: (i) VegT, the maternal mesendoderm determinant in Xenopus, is required for the deposition of H3K27ac and H3K9ac at its target gene loci during mesendoderm induction; (ii) Ascl1 and VegT antagonistically modulate the deposition of acetylated histone marks at mesendoderm gene loci; (iii) Ascl1 overexpression reduces the VegT-occupancy at mesendoderm gene loci; (iv) Ascl1 but not Neurog2 possesses a repressive activity during mesendoderm induction. These findings reveal a novel repressive function for Ascl1 in inhibiting non-neural fates during early Xenopus embryogenesis.
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Affiliation(s)
- Zheying Min
- MOE Key Laboratory of Protein Sciences, Tsinghua University School of Life Sciences, Beijing 100084, China
| | - Hao Lin
- MOE Key Laboratory of Protein Sciences, Tsinghua University School of Life Sciences, Beijing 100084, China
| | - Xuechen Zhu
- MOE Key Laboratory of Protein Sciences, Tsinghua University School of Life Sciences, Beijing 100084, China
| | - Li Gao
- MOE Key Laboratory of Protein Sciences, Tsinghua University School of Life Sciences, Beijing 100084, China
| | - Aftab A Khand
- MOE Key Laboratory of Protein Sciences, Tsinghua University School of Life Sciences, Beijing 100084, China
| | - Qinghua Tao
- MOE Key Laboratory of Protein Sciences, Tsinghua University School of Life Sciences, Beijing 100084, China
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