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Lu CF, Zhou YN, Zhang J, Su S, Liu Y, Peng GH, Zang W, Cao J. The role of epigenetic methylation/demethylation in the regulation of retinal photoreceptors. Front Cell Dev Biol 2023; 11:1149132. [PMID: 37305686 PMCID: PMC10251769 DOI: 10.3389/fcell.2023.1149132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 05/09/2023] [Indexed: 06/13/2023] Open
Abstract
Photoreceptors are integral and crucial for the retina, as they convert light into electrical signals. Epigenetics plays a vital role in determining the precise expression of genetic information in space and time during the development and maturation of photoreceptors, cell differentiation, degeneration, death, and various pathological processes. Epigenetic regulation has three main manifestations: histone modification, DNA methylation, and RNA-based mechanisms, where methylation is involved in two regulatory mechanisms-histone methylation and DNA methylation. DNA methylation is the most studied form of epigenetic modification, while histone methylation is a relatively stable regulatory mechanism. Evidence suggests that normal methylation regulation is essential for the growth and development of photoreceptors and the maintenance of their functions, while abnormal methylation can lead to many pathological forms of photoreceptors. However, the role of methylation/demethylation in regulating retinal photoreceptors remains unclear. Therefore, this study aims to review the role of methylation/demethylation in regulating photoreceptors in various physiological and pathological situations and discuss the underlying mechanisms involved. Given the critical role of epigenetic regulation in gene expression and cellular differentiation, investigating the specific molecular mechanisms underlying these processes in photoreceptors may provide valuable insights into the pathogenesis of retinal diseases. Moreover, understanding these mechanisms could lead to the development of novel therapies that target the epigenetic machinery, thereby promoting the maintenance of retinal function throughout an individual's lifespan.
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Affiliation(s)
- Chao-Fan Lu
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Ya-Nan Zhou
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Jingjing Zhang
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Songxue Su
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Yupeng Liu
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Guang-Hua Peng
- Department of Pathophysiology, Basic Medical College, Zhengzhou University, Zhengzhou, China
- Laboratory of Visual Cell Differentiation and Regulation, Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Weidong Zang
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Jing Cao
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, China
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Iwagawa T, Kawabata R, Fukushima M, Kuribayashi H, Watanabe S. Setd5, but not Setd2, is indispensable for retinal cell survival and proliferation. FEBS Lett 2023; 597:427-436. [PMID: 36349512 DOI: 10.1002/1873-3468.14537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 10/17/2022] [Accepted: 10/27/2022] [Indexed: 11/10/2022]
Abstract
Trimethylation of histone H3 at lysine 36 (H3K36me3) is associated with active transcription. We used mouse retinal explant cultures and shRNA to investigate the roles of Setd2 and Setd5, which encode H3K36me3 methyltransferases, in retinal development. We found that shSetd5 caused abnormal retinal structures and reduced rods and Müller cells, whereas shSetd2 did not cause any abnormalities. The mutant SETD5 lacking the SET domain failed to reverse the phenotypes observed in the shSetd5-expressing retinas, while SETD5S1257*, which does not interact with HDAC3 and PAF1 complexes, rescued proliferation, but not apoptosis, induced by shSetd5. Taken together, we found that Setd5, but not Setd2, is essential for sustaining retinal cell survival and proliferation, and the SET domain of SETD5 is pivotal for both functions.
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Affiliation(s)
- Toshiro Iwagawa
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan.,Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Japan
| | - Ryoko Kawabata
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan.,Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Japan
| | - Masaya Fukushima
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan.,Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Japan
| | - Hiroshi Kuribayashi
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan.,Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Japan
| | - Sumiko Watanabe
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan.,Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Japan
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Zhang X, Zhang BW, Xiang L, Wu H, Sahiri Alexander SUPITA, Zhou P, Zi-Yu Dai M, Wang X, Xiong W, Zhang Y, Jin ZB, Deng LW. MLL5 is involved in retinal photoreceptor maturation through facilitating CRX-mediated photoreceptor gene transactivation. iScience 2022; 25:104058. [PMID: 35359806 PMCID: PMC8961232 DOI: 10.1016/j.isci.2022.104058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/11/2021] [Accepted: 03/07/2022] [Indexed: 11/06/2022] Open
Abstract
Histone methylation, particularly at the H3K4 position, is thought to contribute to the specification of photoreceptor cell fate; however, the mechanisms linking histone methylation with transcription factor transactivation and photoreceptor gene expression have not yet been determined. Here, we demonstrate that MLL5 is abundantly expressed in the mouse retina. Mll5 deficiency impaired electroretinogram responses, alongside attenuated expression of a number of retina genes. Mechanistic studies revealed that MLL5 interacts with the retina-specific transcription factor, CRX, contributing to its binding to photoreceptor-specific gene promoters. Moreover, depletion of MLL5 impairs H3K4 methylation and H3K79 methylation, which subsequently compromises CRX-CBP assembly and H3 acetylation on photoreceptor promoters. Our data support a scenario in which recognition of H3K4 methylation by MLL5 is required for photoreceptor-specific gene transcription through maintaining a permissive chromatin state and proper CRX-CBP recruitment at promoter sites. MLL5 is essential for the expression of critical photoreceptor genes MLL5 depletion reduces H3K4/K79 methylation at photoreceptor gene promoters MLL5 interacts with CRX via its CD4 domain Recognition of H3K4me2/3 by MLL5 is a prerequisite for CRX recruitment to chromatin
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