Exploring a role for regulation of TGFbeta signaling during photoreceptor regener

探索光感受器再生过程中 TGFbeta 信号传导的调节作用

• 批准号: 8254869
• 负责人: Jenny Rae Lenkowski
• 金额: $ 5.22万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8254869
• 关键词: Activins; Adult; Animals; Area; Behavior; Biological Models; Biomedical Research; Blindness; Cells; Cessation of life; Chemicals; Cicatrix; Data; Defect; Development; Event; Exhibits; Explosion; Eye; Face; Fishes; Future; Gene Expression; Gene Targeting; Genes; Genetic; Germ Cells; Heart; Hereditary Disease; Homeobox; Hour; Human; Human Genetics; Image; Injury; Lesion; Light; Microarray Analysis; Mitotic; Modeling; Molecular; Monitor; Natural regeneration; Neural Retina; Neuraxis; Neuroglia; Neurons; Nodal; Organ; Pathway interactions; Pattern; Phosphorylation; Photoreceptors; Property; Prosencephalon; Proteins; Publishing; Regenerative Medicine; Regulation; Relative (related person); Renal Tissue; Reporter; Repression; Research; Retina; Retinal; Role; Signal Transduction; Staging; Stem cells; System; Techniques; Testing; Therapeutic; Time; Tissues; Transforming Growth Factor beta; Transgenic Organisms; Vertebrates; Vision; Visual impairment; Zebrafish; adult stem cell; embryonic stem cell; functional restoration; in vivo; in vivo Model; interest; mutant; progenitor; programs; regenerative; response; retinal damage; retinal progenitor cell; retinal regeneration; stem cell therapy; systems research; teleost fish; therapeutic target; tool

DESCRIPTION (provided by applicant): With the recent explosion of interest in regenerative medicine and stem cell therapies, biologists have reinvested in the study of regeneration with modern molecular techniques that were not available in the field's early years. Conditional mutants and transgenic zebrafish, a teleost fish model research system, are useful tools to study human genetic diseases, development, and mechanisms of adult stem cell activation and regeneration. In fact, zebrafish are used in regeneration research because they have a robust capacity to regenerate the fins, portions of the heart, renal tissue, and importantly the neural retina. Genetic tools facilitate this research because signaling mechanisms controlling regeneration can be explored in the context of an in vivo model system and then be applied to biomedical research in mammalian model systems. In mammalian systems, when the retina is damaged, M|ller glial (MG) cells react to the damage by forming a glial scar and do not restore vision. In contrast, the zebrafish MG act as retinal stem cells to regenerate the lost photoreceptors and restore vision within 2 weeks after the light injury. A microarray analysis of isolated MG from regenerating retinas in the first 36 hours after light damage found similar gene expression changes in MG cells compared with previously published studies of the regenerating heart and fin, including the transcriptional co-repressors TGF2-interacting factor (tgif1) and sine oculis-related homeobox 3b (six3b). This suggests that tgif1 and six3b may be involved in a general regeneration program that is not tissue-specific. Both of these genes repress TGF2 signaling and are associated with congenital forebrain and facial defects in humans. Because tgif1 and six3b have common roles and both increase early in the MG of damaged retina, increased tgif1 and six3b expression may allow for the dedifferentiation and/or mitotic activation of MG stem cells during the early stages of retina regeneration by dynamically regulating TGF2 signaling. The proposed research will provide a comprehensive analysis of the role tgif1 and six3b have in early retina regeneration and develop a new transgenic fish line and retinal explant system to use in future studies of retinal regeneration. This research will inform studies of the mammalian MG following retinal damage by identifying genes that are necessary for induction of MG proliferation and subsequent regeneration, thus providing potential therapeutic targets for regenerative medicine. PUBLIC HEALTH RELEVANCE: The proposed research will help define what changes in gene expression are necessary in the stem cells of the retina, M|ller glia, to regenerate lost photoreceptors after damage and restore eye sight. The results of this study will help determine gene targets for developing therapeutic treatments for blindness and low vision in humans.

描述（由申请人提供）：随着最近对再生医学和干细胞疗法的兴趣激增，生物学家已经重新投资于使用该领域早期不可用的现代分子技术进行再生研究。条件突变体和转基因斑马鱼作为硬骨鱼的模式研究系统，是研究人类遗传疾病、发育和成体干细胞活化与再生机制的有用工具。事实上，斑马鱼被用于再生研究，因为它们有强大的能力再生鳍，心脏，肾组织的一部分，重要的是神经视网膜。遗传工具促进了这项研究，因为控制再生的信号机制可以在体内模型系统的背景下进行探索，然后应用于哺乳动物模型系统的生物医学研究。 在哺乳动物系统中，当视网膜受损时，M|较小的神经胶质（MG）细胞通过形成神经胶质瘢痕对损伤作出反应，并且不能恢复视力。相比之下，斑马鱼MG作为视网膜干细胞再生失去的光感受器，并在光损伤后2周内恢复视力。在光损伤后的第一个36小时内，从再生视网膜中分离的MG的微阵列分析发现，与先前发表的再生心脏和鳍的研究相比，MG细胞中的基因表达变化相似，包括转录辅抑制因子TGF 2相互作用因子（tgif 1）和sine oculis-related homeobox 3b（six 3b）。这表明tgif 1和six 3b可能参与了一个一般的再生程序，而不是组织特异性的。这两种基因都抑制TGF 2信号传导，并与人类先天性前脑和面部缺陷有关。由于tgif 1和six 3b具有共同的作用，并且在受损视网膜的MG早期均增加，因此增加的tgif 1和six 3b表达可能允许MG干细胞在视网膜再生的早期阶段通过动态调节TGF 2信号传导而去分化和/或有丝分裂活化。这项研究将全面分析tgif 1和six 3b在早期视网膜再生中的作用，并开发一种新的转基因鱼线和视网膜外植体系统，用于未来的视网膜再生研究。这项研究将通过鉴定诱导MG增殖和随后再生所必需的基因，为视网膜损伤后的哺乳动物MG研究提供信息，从而为再生医学提供潜在的治疗靶点。 公共卫生相关性：这项研究将有助于确定视网膜干细胞中基因表达的哪些变化是必要的，M| ller胶质细胞，以再生受损后失去的光感受器并恢复视力。这项研究的结果将有助于确定开发人类失明和低视力治疗方法的基因靶点。