Enhancement of Axonal Penetration through Cross-Facial Nerve Grafts

通过跨面神经移植增强轴突穿透

• 批准号: 9760987
• 负责人: Suresh Mohan
• 金额: $ 6.64万
• 依托单位: MASSACHUSETTS EYE AND EAR INFIRMARY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9760987
• 关键词: Animal Model; Apoptosis; Apoptotic; Autologous Transplantation; Axon; Axotomy; Behavior; Bioinformatics; Cell Nucleus; Clinical; Communication; Data; Denervation; Distal; Esthetics; Face; Facial motor nucleus; Facial nerve structure; Facial paralysis; Failure; Gene Delivery; Genes; Genetic Transcription; Goals; Gold; Harvest; Heterogeneity; Human; Implant; Injury; Isogenic transplantation; JUN gene; K-Series Research Career Programs; Knowledge; Lip structure; Mediating; Microsurgery; Modeling; Molecular; Motor Neurons; Mus; Muscle; Natural regeneration; Nerve; Nerve Regeneration; Nerve Transfer; Neurons; Operative Surgical Procedures; Organ Transplantation; Outcome; Paralysed; Pathway interactions; Penetration; Phenotype; Population; Procedures; Research; Rodent; Route; Schwann Cells; Side; Smiling; Surgical Models; Techniques; Time; Transplantation; Work; axon growth; axon regeneration; clinical translation; expectation; fluorescence imaging; improved; in vivo; nerve autograft; new therapeutic target; next generation sequencing; novel; operation; peripheral nerve regeneration; regenerative; repaired; response; response to injury; restoration; sciatic nerve; senescence; skills; small molecule; spatiotemporal; subcutaneous; success; therapeutic target; transcriptome; transcriptome sequencing; transdifferentiation

Proposal Summary Facial palsy (FP) is a vexing clinical condition with massive functional, aesthetic, and communication sequelae. The gold-standard clinical approach to smile reanimation in FP involves placing a nerve autograft across the upper lip that routes axons from a healthy-side facial nerve donor branch to the paralyzed side. In a subsequent surgery, free muscle is transplanted into the paralyzed side and neurotized by the cross-facial nerve graft (CFNG). The operation carries a 30% failure rate for incompletely understood reasons. Emerging evidence suggests Schwann cells (SCs) in distal portions of long grafts become less supportive of axonal regeneration following prolonged periods without axonal contact. Axonal growth arrest across long grafts results in suboptimal neurotization of distal targets and procedural failure. The molecular mechanisms underlying SC response to long-term denervation remain incompletely understood. Prolonging the pro- regenerative SC state within nerve grafts is a promising therapeutic target for enhancing clinical outcomes in smile reanimation. The goal of the proposed research is to characterize the transcriptional responses of CFNG SCs and facial motor neurons (FMNs) following axotomy and coaptation to freshly harvested as compared to long-term denervated nerve grafts. While prior work has employed quantitative PCR and bulk RNA sequencing to study peripheral nerve regeneration, such an approach assumes SCs and neurons are homogeneous populations. Herein, we hypothesize that transcriptional heterogeneity exists among nerve graft SCs following injury, and that differences exist between transcriptomes of FMNs whose axons are coapted to freshly harvested as opposed to long-term denervated nerve grafts. A novel mouse surgical model of prolonged nerve graft denervation simulating long nerve grafts in humans will be developed, and relationships between SC and FMN expression assessed using DroNc-seq, a novel massively parallel single nucleus RNA-sequencing technique. New knowledge will be gained regarding the molecular mechanisms underlying SC and FMN transcriptional changes following injury and nerve grafting. Such knowledge could inform therapeutic targets to prolong the SC repair state, mitigate apoptosis, and enhance clinical outcomes in nerve regeneration and smile reanimation.

提案摘要 面神经麻痹（FP）是一种令人烦恼的临床状况，具有大量的功能，美学和交流后遗症。 FP微笑复苏的金标准临床方法包括将自体神经移植物穿过 将轴突从健康侧的面神经供体分支引导到瘫痪侧的上唇。中 随后的手术中，将游离肌肉移植到瘫痪的一侧，并通过跨面部神经化， 神经移植物（CFNG）。由于不完全理解的原因，该操作有30%的失败率。新兴 有证据表明，长移植物远端部分的雪旺细胞（SC）对轴突的支持性降低， 在没有轴突接触的情况下长时间再生。长移植物轴突生长阻滞 导致远端目标的次优神经化和手术失败。的分子机制 潜在的SC对长期去神经支配的反应仍然不完全清楚。延长亲- 神经移植物内的再生SC状态是一种有前途的治疗靶点，用于增强神经移植物的临床结果。 微笑复苏。 这项研究的目的是描述CFNG SC和面部神经元的转录反应。 运动神经元（FMNs）后轴突切断和接合新鲜收获相比，长期 去神经移植物虽然先前的工作已经采用定量PCR和批量RNA测序来研究 对于外周神经再生，这种方法假设SC和神经元是同质群体。 在此，我们假设损伤后神经移植物SC之间存在转录异质性， 不同的转录组之间存在的FMNs的轴突接合到新鲜收获， 而不是长期的去神经移植。一种新的小鼠神经移植延长模型 将开发模拟人类长神经移植物的去神经，以及SC和FMN之间的关系。 使用DroNc-seq评估表达，DroNc-seq是一种新型的大规模平行单核RNA测序技术。 新的知识将获得有关的分子机制SC和FMN转录 损伤和神经移植后的变化。这些知识可以为治疗靶点提供信息， SC修复状态，减轻凋亡，并增强神经再生和微笑的临床结果 复活