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Wnt/β-catenin signalling is required for pole-specific chromatin remodeling during planarian regeneration. Nat Commun 2023; 14:298. [PMID: 36653403 PMCID: PMC9849279 DOI: 10.1038/s41467-023-35937-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/09/2023] [Indexed: 01/19/2023] Open
Abstract
For successful regeneration, the identity of the missing tissue must be specified according to the pre-existing tissue. Planarians are ideal for the study of the mechanisms underlying this process; the same field of cells can regrow a head or a tail according to the missing body part. After amputation, the differential activation of the Wnt/β-catenin signal specifies anterior versus posterior identity. Initially, both wnt1 and notum (Wnt inhibitor) are expressed in all wounds, but 48 hours later they are restricted to posterior or anterior facing wounds, respectively, by an unknown mechanism. Here we show that 12 hours after amputation, the chromatin accessibility of cells in the wound region changes according to the polarity of the pre-existing tissue in a Wnt/β-catenin-dependent manner. Genomic analyses suggest that homeobox transcription factors and chromatin-remodeling proteins are direct Wnt/β-catenin targets, which trigger the expression of posterior effectors. Finally, we identify FoxG as a wnt1 up-stream regulator, probably via binding to its first intron enhancer region.
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Akter S, Shimba A, Ikuta K, Mahmud MRA, Yamada S, Sasanuma H, Tsuda M, Sone M, Ago Y, Murai K, Tanaka H, Takeda S. Physiological concentrations of glucocorticoids induce pathological DNA double-strand breaks. Genes Cells 2023; 28:53-67. [PMID: 36415926 DOI: 10.1111/gtc.12993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/15/2022] [Accepted: 11/15/2022] [Indexed: 11/24/2022]
Abstract
Steroid hormones induce the transcription of target genes by activating nuclear receptors. Early transcriptional response to various stimuli, including hormones, involves the active catalysis of topoisomerase II (TOP2) at transcription regulatory sequences. TOP2 untangles DNAs by transiently generating double-strand breaks (DSBs), where TOP2 covalently binds to DSB ends. When TOP2 fails to rejoin, called "abortive" catalysis, the resulting DSBs are repaired by tyrosyl-DNA phosphodiesterase 2 (TDP2) and non-homologous end-joining (NHEJ). A steroid, cortisol, is the most important glucocorticoid, and dexamethasone (Dex), a synthetic glucocorticoid, is widely used for suppressing inflammation in clinics. We here revealed that clinically relevant concentrations of Dex and physiological concentrations of cortisol efficiently induce DSBs in G1 phase cells deficient in TDP2 and NHEJ. The DSB induction depends on glucocorticoid receptor (GR) and TOP2. Considering the specific role of TDP2 in removing TOP2 adducts from DSB ends, induced DSBs most likely represent stalled TOP2-DSB complexes. Inhibition of RNA polymerase II suppressed the DSBs formation only modestly in the G1 phase. We propose that cortisol and Dex frequently generate DSBs through the abortive catalysis of TOP2 at transcriptional regulatory sequences, including promoters or enhancers, where active TOP2 catalysis occurs during early transcriptional response.
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Affiliation(s)
- Salma Akter
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akihiro Shimba
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Koichi Ikuta
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Md Rasel Al Mahmud
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shintaro Yamada
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Sasanuma
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masakatsu Sone
- Department of Metabolic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Division of Metabolism and Endocrinology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Yukio Ago
- Department of Cellular and Molecular Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kenichi Murai
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Hisashi Tanaka
- Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Shenzhen University School of Medicine, Shenzhen University, Shenzhen, Guangdong, China
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Liu S, Miyaji M, Hosoya O, Matsuo T. Effect of NK-5962 on Gene Expression Profiling of Retina in a Rat Model of Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms222413276. [PMID: 34948073 PMCID: PMC8703378 DOI: 10.3390/ijms222413276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/18/2022] Open
Abstract
Purpose: NK-5962 is a key component of photoelectric dye-coupled polyethylene film, designated Okayama University type-retinal prosthesis (OUReP™). Previously, we found that NK-5962 solution could reduce the number of apoptotic photoreceptors in the eyes of the Royal College of Surgeons (RCS) rats by intravitreal injection under a 12 h light/dark cycle. This study aimed to explore possible molecular mechanisms underlying the anti-apoptotic effect of NK-5962 in the retina of RCS rats. Methods: RCS rats received intravitreal injections of NK-5962 solution in the left eye at the age of 3 and 4 weeks, before the age of 5 weeks when the speed in the apoptotic degeneration of photoreceptors reaches its peak. The vehicle-treated right eyes served as controls. All rats were housed under a 12 h light/dark cycle, and the retinas were dissected out at the age of 5 weeks for RNA sequence (RNA-seq) analysis. For the functional annotation of differentially expressed genes (DEGs), the Metascape and DAVID databases were used. Results: In total, 55 up-regulated DEGs, and one down-regulated gene (LYVE1) were found to be common among samples treated with NK-5962. These DEGs were analyzed using Gene Ontology (GO) term enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway analyses. We focused on the up-regulated DEGs that were enriched in extracellular matrix organization, extracellular exosome, and PI3K–Akt signaling pathways. These terms and pathways may relate to mechanisms to protect photoreceptor cells. Moreover, our analyses suggest that SERPINF1, which encodes pigment epithelium-derived factor (PEDF), is one of the key regulatory genes involved in the anti-apoptotic effect of NK-5962 in RCS rat retinas. Conclusions: Our findings suggest that photoelectric dye NK-5962 may delay apoptotic death of photoreceptor cells in RCS rats by up-regulating genes related to extracellular matrix organization, extracellular exosome, and PI3K–Akt signaling pathways. Overall, our RNA-seq and bioinformatics analyses provide insights in the transcriptome responses in the dystrophic RCS rat retinas that were induced by NK-5962 intravitreal injection and offer potential target genes for developing new therapeutic strategies for patients with retinitis pigmentosa.
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Affiliation(s)
- Shihui Liu
- Department of Ophthalmology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama City 700-8558, Japan;
| | - Mary Miyaji
- Department of Medical Neurobiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama City 700-8558, Japan; (M.M.); (O.H.)
| | - Osamu Hosoya
- Department of Medical Neurobiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama City 700-8558, Japan; (M.M.); (O.H.)
| | - Toshihiko Matsuo
- Department of Ophthalmology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama City 700-8558, Japan;
- Correspondence:
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Liu S, Matsuo T, Miyaji M, Hosoya O. The Effect of Cyanine Dye NK-4 on Photoreceptor Degeneration in a Rat Model of Early-Stage Retinitis Pigmentosa. Pharmaceuticals (Basel) 2021; 14:694. [PMID: 34358120 PMCID: PMC8308753 DOI: 10.3390/ph14070694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 12/16/2022] Open
Abstract
The present study aimed to evaluate the effects of NK-4 on the apoptosis of photoreceptors in a rat model of retinitis pigmentosa and explore the mechanism underlying anti-apoptosis activity. The Royal College of Surgeons (RCS) rats received an intravitreous injection of NK-4 solution in the left eye and vehicle control in the right eye. Apoptosis was detected by TUNEL method in frozen sections of the eyes. The retinal tissues of the rats were dissected for RNA-seq analysis. Functional and pathway enrichment analyses of differentially expressed genes (DEGs) were performed by using Metascape and DAVID software. The expression levels of DEGs were confirmed by real-time quantitative PCR (RT-qPCR). The number of apoptotic cells decreased in the outer nuclear layer (ONL) and the thickness of the ONL was significantly thicker in the retina of NK-4-injected eyes, compared with control eyes. Five DEGs were identified by RNA-seq analysis, and Hmox1, Mt1, Atf5, Slc7a11, and Bdh2 were confirmed to be up-regulated by RT-qPCR. Functional and pathway enrichment analysis of the up-regulated genes showed that anti-apoptosis effects of NK-4 in the retina of RCS rats may be related to the pathways of metal ion homeostasis, negative regulation of neuron death, response to toxic substance, and pigment metabolic process. We found a potential mechanism of NK-4, providing a new viewpoint for the development of more therapeutic uses of NK-4 in the future.
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Affiliation(s)
- Shihui Liu
- Department of Ophthalmology, Okayama University Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama City 700-8558, Japan;
| | - Toshihiko Matsuo
- Department of Ophthalmology, Okayama University Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama City 700-8558, Japan;
| | - Mary Miyaji
- Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama City 700-8558, Japan; (M.M.); (O.H.)
| | - Osamu Hosoya
- Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama City 700-8558, Japan; (M.M.); (O.H.)
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