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Principal Investigator: Mei Wan
Organization: JOHNS HOPKINS UNIVERSITY
Fiscal Year: 2024
Award: $409,375
Funding agency: National Eye Institute
Summary
To date, targeting the genes regulating intrinsic axon growth ability have produced by far the most promising
results in optic nerve regeneration. Recent studies, including ours, have provided strong evidence that neuronal
aging might be a key converging process underlying the loss of intrinsic axon growth ability of CNS neurons.
Indeed, many genes that act to regulate axon regeneration are also hallmark genes of aging (genomic instability,
telomere attrition, epigenetic alteration, and nutrient sensing, etc.). First, recent studies and our preliminary
results showed that c-Myc and p53, two well-known genes involved in DNA repair and genomic instability during
aging, act to support optic nerve regeneration. Second, our preliminary study showed that telomerase reverse
transcriptase (TERT) was necessary for sensory axon regeneration in vivo. Third, aging is often associated with
decreased methylation of histone 3 at lysine 27 (H3K27) and increased methylation of H3K4, resulting in reduced
amount of heterochromatin. In support, the level of H3K27 demethylase UTX increases during aging and
knocking out UTX in c. elegans promotes longevity. Our unpublished study showed that knocking out UTX and
its targeted gene, Magi3, in RGCs drastically promoted optic nerve regeneration. Fourth, the insulin and IGF-1
signaling (IIS) pathways, the key regulators of nutrient sensing, are the most conserved aging controlling
pathway in evolution. IGF-1 and many IIS downstream targets, such as Pten/PI3K, Akt, and mTor, are all
important regulators of optic nerve regeneration. Our published study and a recent study have shown that Sirt1
and LKB1, two important nutrient sensors, function to regulate sensory axon and spinal cord regeneration,
respectively. Foxo3, another key target of Akt signaling, has recently been shown to promote vascular cell
regeneration through Sirt1. Lastly, recent findings indicated that cellular reprogramming process can reverse
aging and rejuvenate the cells. Importantly, manipulations of several reprogramming factors, such as KLF4 and
Lin28, have been shown to promote optic nerve regeneration. Therefore, we hypothesize that aging regulatory
genes/pathways can be manipulated to promote optic nerve regeneration through rejuvenation of mature CNS
neurons. In Aim 1, we will determine if manipulation of miR-138/Sirt1, TERT, and Foxo3 in RGCs can promote
optic nerve regeneration. In Aim 2, we will first determine if combination of these aging genes with myosin II
knockout or enhanced neural activity would have synergistic effects on regeneration. We will then use RNA-seq
and ATAC-seq of purified RGCs to explore how these aging genes regulate optic nerve regeneration. In Aim 3, by
performing RNA-seq and ATAC-seq of purified RGCs at different developing, maturation, and aging stages, we
will first use advanced integrative bioinformatics analyses to identify top candidate aging genes and their
associated transcription factors, both of which act to orchestrate RGCs aging. We will then perform functional
screening experiments to determine their roles in regulation of axon growth and optic nerve regeneration.
Terms: <1-Phosphatidylinositol 3-Kinase><ATAC sequencing><ATAC-seq><ATACseq><Aging><Antioncogene Protein p53><Assay for Transposase-Accessible Chromatin using sequencing><Axon><Basal Transcription Factor><Basal transcription factor genes><Bio-Informatics><Bioinformatics><Biomedical Research><Blood Vessels><Brain><Brain Nervous System><Brain Trauma><C elegans><C. elegans><C.elegans><CNS Nervous System><Caenorhabditis elegans><Catalytic Core><Catalytic Domain><Catalytic Region><Catalytic Site><Catalytic Subunit><Cell Aging><Cell Body><Cell Communication and Signaling><Cell Reprogramming><Cell Senescence><Cell Signaling><Cells><Cellular Aging><Cellular Matrix><Cellular Senescence><Cellular Tumor Antigen P53><Central Nervous System><Chromatin><Chromosomal Fragility><Chromosome Fragility><Consensus><Corticospinal Tracts><Cranial Nerve II><Cranial Nerve II Injuries><Cytoskeletal System><Cytoskeleton><DNA Damage Repair><DNA Repair><DREADDs><Data><Degenerative Neurologic Disorders><Development><EC 2.7.7.49><Encephalon><Enzyme Gene><Enzymes><Epigenetic><Epigenetic Change><Epigenetic Mechanism><Epigenetic Process><Evolution><FK506 Binding Protein 12-Rapamycin Associated Protein 1><FKBP12 Rapamycin Complex Associated Protein 1><FKHR-Like 1><FKHRL1><FOXO3><FOXO3A><FOXO3A gene><FRAP1><FRAP1 gene><FRAP2><Failure><Forkhead Box O3A><Forkhead in Rhabdomyosarcoma-Like 1><Gene Down-Regulation><Gene Transcription><General Transcription Factor Gene><General Transcription Factors><Genes><Genetic Technics><Genetic Techniques><Genetic Transcription><Genome Instability><Genomic Instability><Heterochromatin><Histones><Humulin R><IGF-1><IGF-1 Signaling Pathway><IGF-I><IGF-I-SmC><Insulin><Insulin-Like Growth Factor 1><Insulin-Like Growth Factor I><Insulin-Like Somatomedin Peptide I><Intracellular Communication and Signaling><Knock-out><Knockout><L-Lysine><LKB1><LKB1/STK11 Gene><Length of Life><Longevity><Lysine><Mechanistic Target of Rapamycin><Mediating><Methylation><Molecular><Molecular Target><Myosin A><Myosin II><Myosin IIA><Myosin Type II><Natural regeneration><Nerve Cells><Nerve Regeneration><Nerve Unit><Nervous System Degenerative Diseases><Neural Cell><Neural Degenerative Diseases><Neural degenerative Disorders><Neuraxis><Neuro-regeneration><Neurocyte><Neurodegenerative Diseases><Neurodegenerative Disorders><Neurologic Degenerative Conditions><Neurons><Neuroregeneration><Noise><Non-Muscle Myosin Type IIA><Nonmuscle Myosin Type IIA><Novolin R><Nutrient><Oncoprotein p53><Optic Nerve><Optic Nerve Injuries><Optic Nerve Trauma><P53><PI-3 Kinase><PI3-Kinase><PI3CG><PI3KGamma><PI3k><PIK3><PIK3CG><PIK3CG gene><Pathway interactions><Phosphatidylinositol 3-Kinase><Phosphatidylinositol-3-OH Kinase><Phosphoinositide 3-Hydroxykinase><Phosphoprotein P53><Phosphoprotein pp53><Process><Production><Protein TP53><Protocol><Protocols documentation><PtdIns 3-Kinase><Publishing><RAFT1><RNA Expression><RNA Seq><RNA Transcriptase><RNA sequencing><RNA-Dependent DNA Polymerase><RNA-Directed DNA Polymerase><RNAseq><Regeneration><Regenerative capacity><Regular Insulin><Regulation><Regulator Genes><Regulatory Pathway><Rejuvenation><Replicative Senescence><Retinal Ganglion Cells><Reverse Transcriptase><Revertase><Role><SIRT1><SIRT1 gene><SOX11><SOX11 gene><SRY-Box 11><SRY-Related HMG-Box Gene 11><STK11><STK11 gene><Second Cranial Nerve><Second Cranial Nerve Injuries><Second Cranial Nerve Trauma><Sensory><Signal Transduction><Signal Transduction Systems><Signaling><Sirtuin 1><Somatomedin C><Spinal Cord Trauma><Spinal Trauma><Spinal cord injured><Spinal cord injury><TP53><TP53 gene><TRP53><Telomerase><Telomere Shortening><Transcription><Transcription Factor Proto-Oncogene><Transcription Repression><Transcription factor genes><Transcriptional Regulatory Elements><Transcriptional Repression><Traumatic Brain Injury><Traumatic Myelopathy><Traumatic Optic Neuropathy><Tumor Protein p53><Tumor Protein p53 Gene><Type I Phosphatidylinositol Kinase><Type III Phosphoinositide 3-Kinase><Unscheduled DNA Synthesis><age associated effects><age effect><age related effects><aging associated><aging associated mechanism><aging effect><aging gene><aging mechanism><aging pathway><aging related><aging related mechanism><aging reversal><assay for transposase accessible chromatin followed by sequencing><assay for transposase accessible chromatin seq><assay for transposase accessible chromatin sequencing><assay for transposase-accessible chromatin with sequencing><axon damage><axon growth><axon injury><axon regeneration><axonal damage><axonal growth><axonal injury><axonal regeneration><biological mechanism of age><biological pathways of age><biological signal transduction><c myc><c-myc Genes><cell regeneration><cellular regeneration><cellular reprogramming><cmyc><degenerative diseases of motor and sensory neurons><degenerative neurological diseases><designer receptors exclusively activated by designer drugs><detection of nutrient><developmental><epigenetically><experiment><experimental research><experimental study><experiments><gene manipulation><gene repression><genetic manipulation><genetically manipulate><genetically perturb><hallmarks of aging><histone methylation><human disease><iPS><iPSC><iPSCs><impact of age><in vivo regeneration><induced pluripotent cell><induced pluripotent stem cell><inducible pluripotent stem cell><influence of age><inhibitor><innovate><innovation><innovative><insight><intracellular skeleton><liver kinase B1><mTOR><mammalian target of rapamycin><nervous system regeneration><neural><neural regeneration><neurodegenerative illness><neuronal><neuroregenerative><novel><nutrient sensing><optic nerve regeneration><overexpress><overexpression><p53 Antigen><p53 Genes><p53 Tumor Suppressor><pathway><perception of nutrients><pillars of aging><protein p53><regenerate><regenerated nerve><regeneration ability><regeneration capacity><regulatory gene><retinal ganglion><reverse aging><reverse aging effects><reversible aging><screening><screenings><sensor><social role><spinal cord regeneration><telomere attrition><trans acting element><transcription factor><transcriptome sequencing><transcriptomic sequencing><transcriptomics><traumatic brain damage><v-myc Avian Myelocytomatosis Viral Oncogene Cellular Homolog><vascular>