Mitochondrial Transplantation Strategies to Promote Recovery after Spinal Cord Injury

促进脊髓损伤后恢复的线粒体移植策略

• 批准号: 9093232
• 负责人: Alexander George Rabchevsky
• 金额: $ 22.58万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9093232
• 关键词: Acute; Allogenic; Animals; Antibodies; Area; Astrocytes; Autologous; Behavioral; Bioenergetics; Cell Culture Techniques; Cells; Chronic; Complement; Confocal Microscopy; Contusions; Data; Dose; Endothelial Cells; Fixatives; Fostering; Frequencies; Functional disorder; Future; Goals; Hindlimb; Histological Techniques; Histology; Homeostasis; Image; Immunohistochemistry; Inflammation; Injury; Investigation; Knowledge; Label; Leg; Limb structure; Locomotion; Locomotor Recovery; Measures; Mediating; Microglia; Mission; Mitochondria; Modeling; Multienzyme Complexes; Muscle; Nervous System Trauma; Neurons; Oligodendroglia; Outer Mitochondrial Membrane; Oxidative Stress; Oxygen Consumption; PC12 Cells; Process; Rattus; Recovery; Recovery of Function; Research; Research Proposals; Respiration; Rodent; Seminal; Series; Site; Soleus Muscle; Source; Spinal; Spinal Cord; Spinal cord injury; Subcellular Fractions; Techniques; Testing; Therapeutic; Time; Tissues; Transplantation; Traumatic injury; base; cell type; clinically relevant; design; dosage; gait examination; improved; inflammatory marker; injured; innovation; insight; muscle transplantation; nano; neuroprotection; novel therapeutic intervention; novel therapeutics; prevent; public health relevance; research study; response; stem; targeted treatment; tissue fixing; trend

 DESCRIPTION (provided by applicant): The current proposal is designed to develop of a new research area that is aimed at transplanting mitochondria into the injured rodent spinal cord as a therapeutic strategy following traumatic spinal cord injury (SCI). We and others have found that maintaining normal mitochondrial bioenergetics after contusion SCI fosters both neuroprotection and functional recovery. However, no studies have examined the effects of transplanting exogenous mitochondria into spinal cord tissue after injury in an attempt to normalize overall cellular bioenergetics and spare adjacent host tissues. Accordingly, this new line of investigations will test, ultimately, whether transplanting exogenous healthy mitochondria into the injured spinal cord promotes functional neuroprotection. Using a rat model of contusion SCI, we have preliminary data showing that allogeneic transgenically-labeled (turboGFP) mitochondria derived from PC12 cells microinjected around the injury site maintain overall cellular bioenergetics assessed 24 hrs later. Moreover, using confocal microscopy to evaluate specific antibodies to both inner and outer mitochondrial membranes, we have preliminary evidence that grafted turboGFP mitochondria integrate within naïve and injured spinal cord tissues. Based on these seminal findings, we propose to conduct a series of transplantation strategies to deliver mitochondria around the injury sites. The ultimate goal is to identify a potential autologous cell source of mitochondria (i.e., leg muscle) to prevent secondary tissue injury that is mediated, in large part, by mitochondrial loss and dysfunction. In summary, Aim 1a will comparatively employ a dose-response approach to assess whether transplanted MitoTracker Red-labeled mitochondria isolated from muscles are equally effective as allogeneic turboGFP mitochondria on cellular bioenergetics and the extent of inflammation following acute contusion SCI. Aim 1b will then assess comparatively the frequency and distribution of labeled mitochondria incorporated into host cells over the first week post-injury. Finally, Aim 2 will establish whether transplantation of muscle-derived mitochondria increases long-term tissue sparing and recovery of hindlimb locomotion following SCI. This project has translational potential wherein mitochondria, notably autologous, can be transplanted around the injury site to spare penumbral tissues. Based on the collective expertise of the PI in cellular transplantation into injured spinal cord tissue and both Co-Is in bioenergetic assessments and mitochondrial-targeted therapeutics for neurotrauma, along with our preliminary feasibility data, there are no foreseen technical obstacles to successfully carry out this project. Notably, future experiments stemming from the results of the current proposal will be designed to test delayed grafting paradigms to extend a more clinically relevant therapeutic time window for transplantation of mitochondria to promote functional recovery in more chronic SCI models.

 描述（由申请人提供）：当前的提案旨在开发一个新的研究领域，旨在将线粒体移植到受伤的啮齿动物脊髓中，作为创伤性脊髓损伤（SCI）后的治疗策略。脊髓损伤后维持正常的线粒体生物能可促进神经保护和功能恢复。然而，尚无研究探讨在损伤后将外源线粒体移植到脊髓组织中以试图使整体细胞生物能正常化和恢复的效果。因此，这一新的研究系列将最终测试将外源健康线粒体移植到受损的脊髓中是否可以促进功能性神经保护，使用挫伤性脊髓损伤的大鼠模型，我们获得的初步数据表明同种异体转基因标记（turboGFP）。 ）来自在损伤部位周围进行显微注射的 PC12 细胞的线粒体在 24 小时后仍保持评估的整体细胞生物能学，此外，使用共聚焦显微镜来评估针对内部和外部的特异性抗体。线粒体膜，我们有初步证据表明移植的涡轮绿色荧光蛋白线粒体整合在幼稚和受伤的脊髓组织中，基于这些开创性的发现，我们建议进行一系列移植策略以将线粒体递送到损伤部位周围。线粒体（即腿部肌肉）的潜在自体细胞来源，以防止在很大程度上由线粒体损失和功能障碍介导的继发性组织损伤。 总之，目标 1a 将相对采用剂量反应方法来评估。从肌肉分离的移植 MitoTracker 红色标记线粒体是否与同种异体 TurboGFP 线粒体在细胞生物能量学上同样有效，以及急性挫伤 SCI 后的炎症程度，然后将比较评估首次掺入宿主细胞中的标记线粒体的频率和分布。最后，目标 2 将确定肌肉来源的线粒体移植是否会增加 SCI 后后肢运动的长期保护和恢复。潜在的线粒体，尤其是自体线粒体，可以移植到损伤部位周围，以保护半影组织。基于 PI 在细胞移植到受损脊髓组织方面的集体专业知识，以及 Co-Is 在生物能评估和线粒体靶向神经创伤治疗方面的专业知识，根据我们的初步可行性数据，成功实施该项目不存在可预见的技术障碍。值得注意的是，根据当前提案的结果进行的未来实验将旨在测试延迟嫁接范式，以扩展更多。线粒体移植的临床相关治疗时间窗可促进慢性 SCI 模型的功能恢复。