Regulation of successful optic nerve regeneration by the mevalonate/cholesterol pathway

甲羟戊酸/胆固醇途径成功调节视神经再生

• 批准号: 10500994
• 负责人: Matthew B Veldman
• 金额: $ 40.38万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10500994
• 关键词: Acute; Affect; American; Animal Model; Animals; Axon; Biological; Blindness; Brain; Cell Survival; Cells; Chemicals; Cholesterol; Coenzyme Q10; Data; Data Set; Disease model; Drug Combinations; Exhibits; Failure; Financial Hardship; Future; Gene Expression; Gene Transfer; Genes; Genetic; Genetic Transcription; Glaucoma; Goals; Growth Cones; Human; Injury; Knowledge; Lipids; Low Density Lipoprotein Receptor; Mammals; Measures; Mediating; Mediator of activation protein; Medical; Metabolic Pathway; Modeling; Mus; Natural regeneration; Neuraxis; Optic Nerve; Optic Nerve Injuries; Organism; Pathology; Pathway interactions; Patients; Pharmacology; Pre-Clinical Model; Process; Protein Import; Protein Isoprenylation; Proteins; Recovery; Recycling; Regenerative Medicine; Regulation; Reporter; Retinal Ganglion Cells; Role; SET gene; Signal Pathway; Source; Synapses; System; Testing; Time; Tissue-Specific Gene Expression; Transgenic Organisms; Translating; Ubiquinone; United States; Up-Regulation; Vision; Visual; Visual system structure; Zebrafish; antagonist; axon injury; axon regeneration; cell injury; chemical genetics; cholesterol trafficking; cost; critical period; differential expression; experimental study; extracellular; gain of function; glycosylation; improved; in vivo; in vivo Model; innovation; knock-down; laser capture microdissection; loss of function; mevalonate; mouse model; negative affect; nerve injury; neuroprotection; novel; novel therapeutics; optic nerve disorder; optic nerve regeneration; overexpression; pre-clinical; prophylactic; receptor expression; relating to nervous system; response; sight restoration; success; teleost fish; tool; transcriptome; transcriptome sequencing; transcriptomics

PROJECT SUMMARY Loss of vision due to optic neuropathies, like glaucoma, is a common cause of blindness in the United States. Unfortunately, these conditions are usually permanent because the central nervous system lacks the ability to regenerate damaged axons. Mammalian models of optic nerve (ON) injury recapitulate the pathology seen in patients making it difficult to understand what is needed for successful regeneration. In contrast, teleost fish, such as the zebrafish, can successfully regenerate damage to the ON and recover lost vision. We are using this organism to study the mechanisms of successful ON regeneration with the hopes of translating these findings into novel therapeutics to improve regeneration in mammalian disease models and patients. In a transcriptome- wide study of retinal ganglion cells (RGCs) during zebrafish ON regeneration we identified the mevalonate and cholesterol pathways as up regulated during this process. Our preliminary data suggests the master transcriptional regulator of these pathways, srebf2, is necessary for successful ON regeneration. We hypothesize that srebf2 mediates ON regeneration by activating the RGC intrinsic mevalonate and cholesterol synthesis pathway and/or inducing expression of receptors for extracellular sources of cholesterol and lipids. Using the powerful genetic and chemical tools available for the zebrafish system, we propose to identify the critical period of srebf2 activity and the downstream mediator(s) of its function. Aim 1 will determine when srebf2 function in RGCs is critical for ON regeneration and using novel reporter lines of srebf2 activity to delineate when transcriptional activity occurs. We will also test if activation of srebf2 activity is sufficient to accelerate ON regeneration. Lastly, we will use laser capture microdissection RNA-seq (LCM-seq) to identify differential gene expression under gain- and loss-of-srebf2 function in RGCs. Aim 2 proposes to identify which RGC intrinsic or extrinsic pathways downstream of srebf2 mediate its function. We will use combinations of drugs and gene knockdown to determine if intrinsic mevalonate/cholesterol synthesis and external supplies are independent, interdependent, and/or compensatory for successful ON regeneration. Depending upon the results of this study we will further examine the downstream intrinsic synthesis pathways for cholesterol, ubiquinone, protein prenylation, and protein N-glycosylation or low-density lipoprotein receptors and their downstream processing. Aim 3 will test the sufficiency of Srebf2 expression to provide neuroprotection and stimulate axon regeneration in a mouse model of acute ON injury. LCM-seq will be used to identify gene expression changes induced in mouse RGCs by Srebf2 and compared to those identified in zebrafish to suggest mechanisms for success or failure. These experiments will delineate the pathways downstream of srebf2 necessary for efficient ON regeneration and suggest paths forward to enhance mammalian regeneration.

项目总结