Characterization of Protein Expression Related to Alzheimer's Disease in the Olfactory Bulb of 5xFAD Mice
- Title
- Characterization of Protein Expression Related to Alzheimer's Disease in the Olfactory Bulb of 5xFAD Mice
- Author(s)
- Kyung Hee Kook
- DGIST Authors
- Kyung Hee Kook ; Cheil Moon ; Han Kyoung Choe
- Advisor
- 문제일
- Co-Advisor(s)
- Han Kyoung Choe
- Issued Date
- 2023
- Awarded Date
- 2023-08-01
- Type
- Thesis
- Description
- Alzheimer’s disease; olfactory dysfunction; hallmark protein of AD; olfactory bulb
- Abstract
- Alzheimer’s disease (AD) is a progressive neurodegenerative memory disorder in which, early diagnosis should be emphasized. A prevalent early symptom of AD is olfactory dysfunction. Partial damage of the olfactory system is causally related to distinct olfactory dysfunctions. Therefore, proteins related to AD pluralistically in the olfactory system are required. This study examined the expression of AD-related proteins, including amyloid beta (Aβ), tau (phosphorylated and total tau), and activated microglia, which is associated with neuroinflammation, in the olfactory bulb (OB) of 5xFAD mouse models of AD. Overall, Aβ began to be expressed in the granule cell and glomerular layer in the OB from 3 months of age in the 5xFAD mice, while the expression pattern of phosphorylated tau did not change. However, the tau dimer manifested in a specific pattern. The expression of total tau increased as AD progressed, suggesting that it was a critical biomarker associated with the disease. In addition, colocalization of Aβ with microglia in the OB and hippocampus, and phosphorylated tau with microglia in the hippocampus during the later stage indicated active inflammation. Thus, this study highlighted the importance of studying AD from a multidisciplinary perspective and suggested that the primary olfactory system may reflect the pathological mechanism of AD at the early stages.|알츠하이머병은 기억 장애를 유발하는 진행성 신경병리학적 질환으로, 초기 단계의 진단이 중요하다. 알츠하이머병의 가장 일반적으로 알려진 초기 증상 중 하나는 후각 기능 장애이다. 후각 시스템의 일부 손상은 특정한 후각 장애와 인과적으로 관련되어 있으므로, 알츠하이머와 관련된 단백질을 다원론적으로 후각 시스템에서 연구함이 필요하다. 본 논문에서는 알츠하이머의 조기 증상으로 나타나는 후각 손실과 관련된 단백질을 규명하기 위해 알츠하이머 동물 모델인 5xFAD의 후각 망울에서 알츠하이머병 관련 단백질인 아밀로이드 베타, 타우 (인산화된 타우와 total tau) 그리고 신경 염증과 관련된 활성화된 마이크로글리아를 확인하였다. 종합적으로 아밀로이드 베타는 3개월부터 후각 망울의 사구체층과 과립 세포에서 발현하기 시작했으며 인산화된 타우는 크게 변화하는 양상이 없었지만, 타우 이합체가 특이적인 패턴으로 발현하는 양상이 관찰되었다. 한편, total tau는 알츠하이머 병이 진행됨에 따라 발현이 증가하였고 이것은 병증과 관련된 또다른 중요한 조직 병리학적 바이오 마커로서 작용할 수 있음을 시사한다. 또한 질병의 중증 시기에 아밀로이드 베타와 마이크로글리아가 후각 망울에서, 인산화된 타우와 마이크로글리아가 해마에서 동일한 위치에 발현하고 있는 것이 관찰되어 염증 작용이 활발하게 일어나고 있음이 확인되었다. 따라서 이 연구는 알츠하이머는 다원론적 관점에서 연구의 중요성을 밝히며 일차 후각 신경계가 알츠하이머 병 초기 단계의 병리학적 기전을 반영할 수 있음을 제안한다.
- Table Of Contents
-
I. INTRODUCTION 1
1.1 Introduction to Alzheimer's Disease (AD) 1
1.2 Histological hallmark based on AT(N) classification of Alzheimer’s disease 1
1.3 Olfactory dysfunction in Alzheimer’s disease as an early marker 5
1.4 Olfactory bulb (OB) in olfactory processing 6
1.5 Biomarkers in the olfactory system of Alzheimer’s disease 9
1.6 5xFAD mouse model 9
1.7 Rationale 10
1.8 Research hypothesis 12
II. MATERIALS & METHODS 13
2.1 Materials 13
2.1.1 Experimental animals 13
2.1.2 Antibodies & Reagents 13
2.2 Methods 14
2.2.1 Genotyping of 5xFAD 14
2.2.2 Tissue preparation 15
2.2.3 Western blot 16
2.2.4 Immunoprecipitation 16
2.2.5 Immunohistochemistry 17
2.2.6 Thioflavin-S staining 17
III. RESULTS 18
3.1 Validation of 5xFAD mice 18
3.1.1 Genotyping of 5xFAD mice 18
3.1.2 Full-length Amyloid Precursor Protein (APP) expression in the olfactory bulb and hippocampus of wild-type and 5xFAD mice 18
3.1.3 Comparison of the expression level of the Amyloid beta (Aβ) monomer in the olfactory bulb and hippocampus of wild-type and 5xFAD mice 21
3.1.4 Expression pattern of Amyloid beta (Aβ) in the olfactory bulb of 5xFAD mice 22
3.2 Tau expression in wild-type and 5xFAD mice 24
3.2.1 pT231 expression in the olfactory bulb and hippocampus of wild-type and 5xFAD mice 24
3.2.2 Verification of the tau dimer in wild-type and 5xFAD mice 26
3.2.3 Total tau expression in the olfactory bulb and hippocampus of wild-type and 5xFAD mice 28
3.3 Co-labeled pT231 and total tau expression in the olfactory bulb of wild-type and 5xFAD mice 30
3.4 Ionized calcium-binding adapter molecule 1 (Iba1) expression in wild-type and 5xFAD mice 32
3.4.1 Ionized calcium-binding adapter molecule 1 (Iba1) expression in the olfactory bulb and hippocampus of wild-type and 5xFAD mice 32
3.4.2 Co-labeled Amyloid beta (Aβ) and Ionized calcium-binding adapter molecule 1 (Iba1) expressions in the olfactory bulb of wild-type and 5xFAD mice 34
3.4.3 Co-labeled pT231 and Ionized calcium-binding adapter molecule 1 (Iba1) expressions in the olfactory bulb of wild-type and 5xFAD mice 37
3.5. Hallmark protein expression level and pattern in 10-month-old female mice 40
3.5.1 Expression of full-length APP in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 41
3.5.2 Amyloid beta (Aβ) expression in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 42
3.5.3 pT231 and tau dimer expression in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 45
3.5.4 Total tau expression in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 48
3.5.5 Co-labeled pT231 and total tau in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 49
3.5.6 Ionized calcium-binding adapter molecule 1 (Iba1) expression in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 52
3.5.7 Co-labeled Amyloid beta (Aβ) and Ionized calcium-binding adapter molecule 1 (Iba1) in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 53
3.5.8 Co-labeled pT231 and Ionized calcium-binding adapter molecule 1 (Iba1) in the olfactory bulb and hippocampus of 10-month-old wild-type and 5xFAD mice 55
IV. DISCUSSION 58
4.1 Summary and interpretation of results 58
4.1.1 Amyloid beta (Aβ) 58
4.1.2 pT231, dimer, and total tau 59
4.1.3 Ionized calcium-binding adapter molecule 1 (Iba1) 61
4.1.4 Colocalization of hallmark proteins 61
4.2 5xFAD: A mouse model of Alzheimer’s disease 62
4.3 Future research direction 63
V. CONCLUSION 65
REFERENCES 66
- URI
-
http://hdl.handle.net/20.500.11750/46418
http://dgist.dcollection.net/common/orgView/200000686267
- Degree
- Master
- Department
- Department of Brain Sciences
- Publisher
- DGIST
- Related Researcher
-
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Moon, Cheil
- Research Interests Brain convergent science based on chemical senses; olfaction; 감각신경계 기반 뇌융합과학; 후각 신경계
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- Department of Brain Sciences Theses Master
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