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Dying Neurons Conduct Repair Processes in the Injured Brain through Osteopontin Expression in Cooperation with Infiltrated Blood Monocytes
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Eun-Hye Joe | - |
| dc.contributor.author | AN JIAWEI | - |
| dc.date.accessioned | 2022-11-29T02:33:05Z | - |
| dc.date.available | 2022-11-29T02:33:05Z | - |
| dc.date.issued | 2022-02 | - |
| dc.identifier.other | 31681 | - |
| dc.identifier.uri | https://dspace.ajou.ac.kr/handle/2018.oak/20574 | - |
| dc.description | 학위논문(박사)--아주대학교 일반대학원 :의생명과학과,2022. 2 | - |
| dc.description.tableofcontents | I. Introduction 1 A. Roles of non-neural cells in the intact brain 1 1. Astrocyte 1 2. Microglia 2 B. Repair of the injured brain of wild type mice 3 1. Repair processes of injured brain 3 2. Diverse factors that mediate repair of the injured brain 4 2.1 Intrinsic factors 4 2.2 Extrinsic factors 6 3. Cells that are involved in the injured brain 7 3.1 Neuron 7 3.2 Astrocyte 8 3.3 Microglia 9 3.4 Monocyte 10 4. Extracellular vesicles 12 C. Neurodegenerative disease and repair of brain injury 15 1. Parkinson's disease and Parkinson's disease-related genes 15 2. Parkinson's disease and brain repair 16 3. LRRK2 G2019S 18 4. LRRK2 G2019S and brain repair 19 D. Aims of the study 23 II. Materials and Methods 24 A. Animals 24 B. Stereotaxic injection 24 C. Magnetic resonance imaging (MRI) 25 D. Skin wound injury 26 E. Tissue preparation 26 F. Immunostaining and image analysis 27 G. Preparation and analysis of exosome fractions 32 H. Electron microscopy 34 I. Fluorescence-activated cell sorting (FACS) 34 J. Cultures of neurons, astrocytes, microglia and macrophages 35 K. Neurite outgrowth assay 37 L. Organotypic cortical slice culture 37 M. LDH assay 37 N. Western blot analysis 38 O. Quantitative real-time PCR 39 P. Transfection and drug treatment 40 Q. Statistical analysis 40 III. Results 42 A. Brain injury and repair in wild type mice 42 1. Damaged neurons in the injured brain express OPN and become fragmented into extracellular particles 42 2. Infiltrated monocytes engulf and fragment neuronal cell bodies 53 3. Fragmented neuronal cell bodies guide the growth of neurites and astrocyte processes toward the injury core 58 4. Exosomes prepared from the injured brain enhance neurite outgrowth 65 B. Brain injury and repair in LRRK2 G2019S mice 70 1. LRRK2 G2019S attenuates the repair processes after injury 70 2. LRRK2 G2019S reduces the number of extracellular vesicles and their OPN levels 76 3. LRRK2 G2019S alters monocyte pyroptosis but not infiltration after brain injury 88 4. Insufficient OPN-positive particles hamper elongation of neurites and astrocyte processes in LRRK2 G2019S mice 99 5. Exosomes containing OPN restore neurite outgrowth in LRRK2 G2019S neurons 103 IV. Discussion 107 A. Brain injury and repair in wild type mice 107 B. Brain injury and repair in LRRK2 G2019S mice 116 V. Conclusion 123 Reference 125 | - |
| dc.language.iso | eng | - |
| dc.publisher | The Graduate School, Ajou University | - |
| dc.rights | 아주대학교 논문은 저작권에 의해 보호받습니다. | - |
| dc.title | Dying Neurons Conduct Repair Processes in the Injured Brain through Osteopontin Expression in Cooperation with Infiltrated Blood Monocytes | - |
| dc.type | Thesis | - |
| dc.contributor.affiliation | 아주대학교 일반대학원 | - |
| dc.contributor.department | 일반대학원 의생명과학과 | - |
| dc.date.awarded | 2022. 2 | - |
| dc.description.degree | Doctoral | - |
| dc.identifier.localId | T000000031681 | - |
| dc.identifier.uci | I804:41038-000000031681 | - |
| dc.identifier.url | https://dcoll.ajou.ac.kr/dcollection/common/orgView/000000031681 | - |
| dc.subject.keyword | LRRK2 G2019S | - |
| dc.subject.keyword | brain repair | - |
| dc.subject.keyword | exosome | - |
| dc.subject.keyword | monocyte | - |
| dc.subject.keyword | osteopontin | - |
| dc.description.alternativeAbstract | The brain has an intrinsic capacity to repair injury, but its specific mechanisms are largely unknown. In the first part of the study, I found that, in wild type mice, despite their incipient death, damaged neurons play a key role in the repair of the damaged brain lesion with the help of monocytes infiltrated from blood. Monocytes phagocytosed damaged and/or dying neurons expressing osteopontin (OPN), then, possibly activated their inflammasome pathway, resulting in pyroptosis. During this process, monocytes released CD63-positive exosome-like vesicles containing OPN. Importantly, following the released exosome-like vesicles, the processes of the neuron and astrocyte were elongated toward the injury core. In addition, the exosomes prepared from the injured brain contained OPN and enhanced neurite outgrowth of cultured neurons in an OPNdependent manner. Thus, the results prove the concept that, in wild type (WT) mice, neurons in the injured brain that are destined to die, perceive the stressful condition and begin the regeneration processes through induction of OPN, ultimately executing the repair process with the help of monocytes recruited from the circulation. In the second part of the study, I examined the roles of brain cells for the repair of the injured brain in an animal model of Parkinson’s disease, LRRK2 G2019S mutant mice. LRRK2 G2019S mutation leads to a reduction in neuron process length and complexity in vitro. I found that in vivo LRRK2 G2019S brains also showed impaired regeneration capacities after injury. Notably, the number of regeneration-related OPN-positive exosomal particles was reduced, consequentially the OPN-related cellular behaviors were also attenuated in the injured LRRK2 G2019S brains. Inflammasome activation and pyroptosis of the infiltrated monocytes were clearly associated with the release of OPN-positive exosomal particles in the injured brains. Monocyte infiltration in the LRRK2 G2019S brains was almost identical to that in the WT brains. In LRRK2 G2019S mice, however, inflammasome activation and pyroptosis of the monocytes were reduced in vivo and in vitro. Moreover, exosomes containing OPN or recombinant OPN could rescue defects of neurite outgrowth in LRRK2 G2019S neurons. Thus, these findings clearly prove that reduction of OPN-containing exosomes results in the defect of repairing capacities in injured LRRK2 G2019S brains, which could be caused by attenuation of inflammasome activation and subsequent pyroptosis in the infiltrated monocytes. | - |
| dc.title.subtitle | Impaired by LRRK2 G2019S Mutation | - |
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- Graduate School of Ajou University > Department of Biomedical Sciences > 4. Theses(Ph.D)
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