Role of Stress Granule Protein Aggregation in Axon Regeneration

应激颗粒蛋白聚集在轴突再生中的作用

• 批准号: 10647839
• 负责人: JEFFERY L TWISS
• 金额: $ 53.42万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10647839
• 关键词: Acceleration; Acute; Address; Adult; Affect; Attenuated; Automobile Driving; Axon; Axotomy; Binding; Biological; Cells; Central Nervous System; Chronic; Clinical; Communities; Complex; Cytoplasmic Granules; Data; FRAP1 gene; G3BP1 gene; Growth; Growth Associated Protein 43; Hour; Human; Importins; In Vitro; Individual; Injury; Knowledge; Lesion; Literature; Messenger RNA; Molecular; Motor; Natural regeneration; Nerve; Nerve Regeneration; Neurons; Neurosciences; Pathway interactions; Peptides; Peripheral Nerves; Peripheral Nervous System; Peripheral nerve injury; Permeability; Phosphorylation; Phosphorylation Inhibition; Phosphotransferases; Physiological; Population; Protein Biosynthesis; Proteins; Publishing; RNA; RNA, Messenger, Stored; Regenerative capacity; Regulation; Reporting; Research; Role; Sensory; Signal Transduction; Solid; Specificity; Spinal Cord; Spinal cord injury; Tertiary Protein Structure; Testing; Therapeutic; Time; Tissues; Translating; Translational Activation; Translations; Viral; Work; axon growth; axon injury; axon regeneration; calreticulin; casein kinase; clinically relevant; cohort; in vivo; injured; injury and repair; insight; knock-down; mRNA Translation; nerve injury; neural repair; neuromechanism; novel therapeutic intervention; overexpression; permissiveness; programs; protein aggregation; recruit; reinnervation; repaired; response to injury; stress granule; tool

Peripheral nerves spontaneously regenerate but the axon growth rate is abysmally slow, such that complete functional reinnervation of targets is rarely achieved in humans. Axon regeneration in the central nervous system is even worse, such that individuals with spinal cord injury (SCI) almost invariably have permanent lose of sensory and motor functions below the level of the lesion. There is a pressing need to accelerate axon regeneration in the peripheral nervous system and increase axon regeneration in the central nervous system. Our research program focuses on axon intrinsic mechanisms of regeneration. Intra-axonally synthesized proteins support axon growth in developing neurons. We have shown that PNS neurons retain the capacity to synthesize proteins in their axons and these proteins support growth of injured axons. Axons of cultured neurons contain thousands of mRNAs – and several lines of evidence point to complex populations of mRNAs in CNS axons in vivo and spinal cord axons contain mRNAs and translational machinery when encouraged to regenerate with permissive substrates. Despite remarkable advances since the early 2000’s, the molecular mechanisms that determine when and where a specific mRNA is translated in axons remain largely unknown. This level of regulation is critical for regulating axon growth capacity. We have shown that mRNAs are stored in PNS axons in RNA-protein aggregates that contain the stress granule protein G3BP1. G3BP1 protein can drive stress granule aggregation, and G3BP1 phosphorylation blocks stress granule assembly. Unlike the classically defined stress granule, axonal G3PB1 protein shows aggregation in uninjured/functioning PNS axons. These axonal G3BP1 aggregates rapidly increase after axotomy, but decrease to below basal levels shortly thereafter with a corresponding increase in phosphorylated G3BP1. G3BP1 binds to mRNAs in axons and attenuates their translation. We have discovered exogenous agents and endogenous signals that trigger disassembly of axonal G3BP1 aggregates. The exogenous agents specifically increase axonal protein synthesis and accelerate axon growth rates in vitro and in vivo. These observations have led us to hypothesize that physiological aggregation of stress granule proteins in axons attenuates axon growth in the injured PNS and CNS by blocking translation of an axonal mRNA cohort. We will test this hypothesis with the following specific aims: Aim 1 – Promotion of axon growth by inhibition of G3BP1 function. Aim 2 – Endogenous mechanisms for axonal G3BP1 aggregate disassembly. Aim 3 – Mechanisms driving axon growth upon disassembly of axonal G3BP1 aggregates. Functional roles for axonal translation have now come to light and we have solid in vivo evidence that this mechanism can be targeted to accelerate axon growth after acute peripheral nerve injury. Completion of the proposed research will bring new insight into mechanisms for temporal regulation of axonal mRNA translation in axon injury & regeneration and uncover new therapeutic strategies for neural repair.

周围神经自发再生，但轴突生长速度极其缓慢，因此 人类很少能实现目标的完全功能性神经再支配。轴突再生 中枢神经系统更糟，例如患有脊髓损伤（SCI）的人 几乎总是在病变水平以下永久丧失感觉和运动功能。 迫切需要加速周围神经系统的轴突再生 增加中枢神经系统的轴突再生。我们的研究计划侧重于轴突 再生的内在机制。轴突内合成的蛋白质支持轴突生长 发育中的神经元。我们已经证明 PNS 神经元保留了合成蛋白质的能力 它们的轴突和这些蛋白质支持受损轴突的生长。培养神经元的轴突含有 数以千计的 mRNA——以及多条证据表明中枢神经系统中存在复杂的 mRNA 群体 当鼓励时，体内轴突和脊髓轴突含有 mRNA 和翻译机制 用允许的基质再生。尽管 自 2000 年代初以来，决定何时何地的分子机制取得了显着进展 轴突中翻译的特定 mRNA 仍然很大程度上未知。这一级别的监管是 对于调节轴突生长能力至关重要。我们已经证明 mRNA 储存在 PNS 轴突中 含有应激颗粒蛋白 G3BP1 的 RNA 蛋白聚集体。 G3BP1蛋白可以驱动 应激颗粒聚集，G3​​BP1 磷酸化阻止应激颗粒组装。与 经典定义的应激颗粒，轴突 G3PB1 蛋白显示未受伤/功能状态下的聚集 PNS 轴突。这些轴突 G3BP1 聚集体在轴突切除后迅速增加，但减少到低于 此后不久基础水平下降，磷酸化 G3BP1 相应增加。 G3BP1 结合 轴突中的 mRNA 并减弱其翻译。我们发现了外源性因素 触发轴突 G3BP1 聚集体分解的内源信号。外源性因素 在体外和体内特异性地增加轴突蛋白质合成并加速轴突生长速率 体内。这些观察使我们假设压力的生理聚集 轴突中的颗粒蛋白通过阻断翻译来减弱受伤的三七和中枢神经系统的轴突生长 轴突 mRNA 队列。我们将通过以下具体目标来检验这一假设： 目标 1 – 通过抑制 G3BP1 功能促进轴突生长。 目标 2 – 轴突 G3BP1 聚集体分解的内源机制。 目标 3 – 轴突 G3BP1 聚集体分解后驱动轴突生长的机制。 轴突翻译的功能作用现已揭示，我们有可靠的体内证据 该机制可以有针对性地加速急性周围神经损伤后的轴突生长。 完成拟议的研究将为时间调节机制带来新的见解 轴突损伤和再生中轴突 mRNA 翻译的研究，并揭示新的治疗策略 神经修复。

项目成果

Profiling Locally Translated mRNAs in Regenerating Axons.

分析再生轴突中局部翻译的 mRNA。

• DOI: 10.1007/978-1-0716-3012-9_8
• 发表时间: 2023
• 期刊: Methods in molecular biology (Clifton, N.J.)
• 作者: Sahoo,PabitraK;Twiss,JefferyL
• 通讯作者: Twiss,JefferyL

PTBP1 regulates injury responses and sensory pathways in adult peripheral neurons.

• DOI: 10.1126/sciadv.adi0286
• 发表时间: 2023-07-28
• 期刊: SCIENCE ADVANCES
• 影响因子: 13.6
• 作者: Alber, Stefanie;Di Matteo, Pierluigi;Zdradzinski, Matthew D.;Dalla Costa, Irene;Medzihradszky, Katalin F.;Kawaguchi, Riki;Di Pizio, Agostina;Freund, Philip;Panayotis, Nicolas;Marvaldi, Letizia;Doron-Mandel, Ella;Okladnikov, Nataliya;Rishal, Ida;Nevo, Reinat;Coppola, Giovanni;Lee, Seung Joon;Sahoo, Pabitra K.;Burlingame, Alma L.;Twiss, Jeffery L.;Fainzilber, Mike
• 通讯作者: Fainzilber, Mike

Neurobiology: Resetting the axon's batteries.

神经生物学：重置轴突的电池。

• DOI: 10.1016/j.cub.2021.06.014
• 发表时间: 2021
• 期刊: Current biology : CB
• 作者: Twiss,JefferyL;Kalinski,AshleyL;Sahoo,PabitraK;Costa,IreneDalla;Giger,RomanJ
• 通讯作者: Giger,RomanJ

The glycine arginine-rich domain of the RNA-binding protein nucleolin regulates its subcellular localization.

• DOI: 10.15252/embj.2020107158
• 发表时间: 2021-10-18
• 期刊: The EMBO journal
• 作者: Doron-Mandel E;Koppel I;Abraham O;Rishal I;Smith TP;Buchanan CN;Sahoo PK;Kadlec J;Oses-Prieto JA;Kawaguchi R;Alber S;Zahavi EE;Di Matteo P;Di Pizio A;Song DA;Okladnikov N;Gordon D;Ben-Dor S;Haffner-Krausz R;Coppola G;Burlingame AL;Jungwirth P;Twiss JL;Fainzilber M
• 通讯作者: Fainzilber M

The functional organization of axonal mRNA transport and translation.

• DOI: 10.1038/s41583-020-00407-7
• 发表时间: 2021-03
• 期刊: Nature reviews. Neuroscience
• 作者: Dalla Costa I;Buchanan CN;Zdradzinski MD;Sahoo PK;Smith TP;Thames E;Kar AN;Twiss JL
• 通讯作者: Twiss JL