Dynamin-related protein 1 and mitochondrial fission adapters regulate presynaptic function

动力相关蛋白 1 和线粒体裂变接头调节突触前功能

• 批准号: 10660812
• 负责人: ROBERT B RENDEN
• 金额: $ 45.02万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-18 至 2028-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10660812
• 关键词: Acute; Adaptor Signaling Protein; Adjuvant; Affect; Aging; Alzheimer' s Disease; Basic Science; Biogenesis; Biological Models; Brain; Cell Survival; Cell membrane; Cell physiology; Cells; Cellular Stress; Chronic; Collaborations; Data; Defect; Development; Disease; Disease Progression; Dissection; Dynamin; Dynamin III; Electric Capacitance; Electron Microscopy; Electrophysiology (science); Embryo; Endocytosis; Environment; Excision; Excitatory Synapse; Fluorescence; Functional disorder; Gene Transfer Techniques; Glutamates; Goals; Health; Homeostasis; Human; Huntington Disease; Impairment; Intervention; Investigation; Knowledge; Measurement; Mediating; Membrane; Mitochondria; Modeling; Morphology; Motivation; Mus; Nerve Degeneration; Nervous System; Neurodegenerative Disorders; Neurons; Organism; Outer Mitochondrial Membrane; Phenotype; Plasma; Play; Population; Preparation; Presynaptic Terminals; Process; Protein Isoforms; Proteins; Reactive Oxygen Species; Recycling; Regulation; Research; Research Personnel; Resolution; Respiration; Retrieval; Role; Route; Shapes; Site; Slice; Stress; Synapses; Synaptic Transmission; Synaptic Vesicles; Testing; Therapeutic; Time; Tissues; Viral; Work; age related; electron tomography; functional restoration; healthspan; light microscopy; loss of function; mitochondrial dysfunction; nanoscale; nervous system disorder; neurotransmission; novel strategies; postnatal; presynaptic; presynaptic neurons; reconstruction; recruit; response; stressor; synaptic function; therapeutic target

The long-term goal of this project is to ameliorate neurotransmission defects due to mitochondrial dysfunction, as a way to stop disease progression to later degenerative stages, increasing healthspan in populations increasingly subject to age-related neurological diseases. Dynamin-related protein 1 (DRP1) acts to promote mitochondrial fission and has been identified as a therapeutic target for limiting aberrant mitochondrial fragmentation in Alzheimer’s and Huntington’s disease. The goal of this project is to determine how DRP1 interaction with mitochondrial fission adapters impacts presynaptic terminal function. We propose that the need for high levels of mitochondrial respiration to support synaptic transmission makes the presynaptic terminal a high cellular stress environment. Regulated mitochondrial fission is important for cell survival in response to cellular stressors, acting through DRP1, but the adapters utilized at the neuronal presynaptic terminal are unknown. In Specific Aim 1, we will examine how loss of the mitochondrial fission adapter proteins MFF and FIS1 affect mitochondria homeostasis and synaptic transmission. In Specific Aim 2, we will examine distinct parameters of mitochondrial function and ultrastructure when DRP1 is eliminated, and attempt to rescue function by targeting DRP1 re-expression to mitochondrial outer membrane. Phenotypic differences will be corelated with those in Aim 1, to generate a complete picture of the effect of regulated mitochondrial fission on synaptic function. DRP1 may also facilitate scission of plasma membrane at the synapse, but the impact of this additional function on synaptic transmission is unresolved. In Specific Aim 3, we will test the hypothesis that DRP1 facilitates synaptic vesicle retrieval and recycling, and determine whether membrane-associated DRP1 is sufficient to facilitate SV retrieval, and restore synaptic transmission. In collaboration, the PI and two other world-class investigators have developed novel approaches to allow dissection of the isoform-specific role(s) of DRP1, using the mouse calyx of Held as a model system. Using a combination of viral-mediated transgenesis, advanced electrophysiology, and high-resolution light and electron microscopy, the ability of specific DRP1 isoforms to support mitochondrial fission versus synaptic transmission and presynaptic SV retrieval will be systematically tested. In contrast to small conventional synapses, experimental accessibility of giant ‘calyx-like’ excitatory synapses allow recordings from the presynaptic terminal, permitting manipulation of presynaptic [ATP] and tracking membrane exo/endocytosis in real time. This approach is necessary to dissect the energy-supporting roles of synaptic mitochondria from mechanisms underlying synaptic vesicle recycling. Results from this project can be used to inform, predict, and test function and dysfunction at conventional glutamatergic synapses where disease-relevant neurodegeneration first appears. Knowledge generated from this project will identify viable routes of intervention for restoring function to synapses where DRP1 function is altered, which can be leveraged therapeutically to alleviate disease-related synaptic dysfunction and neurodegeneration.

The long-term goal of this project is to ameliorate neurotransmission defects due to mitochondrial dysfunction, as a way to stop disease progression to later degenerative stages, increasing healthspan in populations increasingly subject to age-related neurological diseases. Dynamin-related protein 1 (DRP1) acts to promote mitochondrial fission and has been identified as a therapeutic target for limiting aberrant mitochondrial fragmentation in Alzheimer’s and Huntington’s disease. The goal of this project is to determine how DRP1 interaction with mitochondrial fission adapters impacts presynaptic terminal function. We propose that the need for high levels of mitochondrial respiration to support synaptic transmission makes the presynaptic terminal a high cellular stress environment. Regulated mitochondrial fission is important for cell survival in response to cellular stressors, acting through DRP1, but the adapters utilized at the neuronal presynaptic terminal are unknown. In Specific Aim 1, we will examine how loss of the mitochondrial fission adapter proteins MFF and FIS1 affect mitochondria homeostasis and synaptic transmission. In Specific Aim 2, we will examine distinct parameters of mitochondrial function and ultrastructure when DRP1 is eliminated, and attempt to rescue function by targeting DRP1 re-expression to mitochondrial outer membrane. Phenotypic differences will be corelated with those in Aim 1, to generate a complete picture of the effect of regulated mitochondrial fission on synaptic function. DRP1 may also facilitate scission of plasma membrane at the synapse, but the impact of this additional function on synaptic transmission is unresolved. In Specific Aim 3, we will test the hypothesis that DRP1 facilitates synaptic vesicle retrieval and recycling, and determine whether membrane-associated DRP1 is sufficient to facilitate SV retrieval, and restore synaptic transmission. In collaboration, the PI and two other world-class investigators have developed novel approaches to allow dissection of the isoform-specific role(s) of DRP1, using the mouse calyx of Held as a model system. Using a combination of viral-mediated transgenesis, advanced electrophysiology, and high-resolution light and electron microscopy, the ability of specific DRP1 isoforms to support mitochondrial fission versus synaptic transmission and presynaptic SV retrieval will be systematically tested. In contrast to small conventional synapses, experimental accessibility of giant ‘calyx-like’ excitatory synapses allow recordings from the presynaptic terminal, permitting manipulation of presynaptic [ATP] and tracking membrane exo/endocytosis in real time. This approach is necessary to dissect the energy-supporting roles of synaptic mitochondria from mechanisms underlying synaptic vesicle recycling. Results from this project can be used to inform, predict, and test function and dysfunction at conventional glutamatergic synapses where disease-relevant neurodegeneration first appears. Knowledge generated from this project will identify viable routes of intervention for restoring function to synapses where DRP1 function is altered, which can be leveraged therapeutically to alleviate disease-related synaptic dysfunction and neurodegeneration.