전신성 뇌 허혈 후 해마에서 유발되는 활성산소 생성과 지연성 신경세포사멸에서 철 (iron)의 역할
Role of Iron in Oxidative Stress and Delayed Neuronal Death in the Hippocampus following Transient Forebrain Ischemia
- 주제(키워드) Iron , Free radicals , Antioxidant , CA1 neurons , Transient forebrain ischemia , Transferrin receptor , Blood-brain-barrier
- 발행기관 아주대학교
- 지도교수 곽병주
- 발행년도 2008
- 학위수여년월 2008. 8
- 학위명 박사
- 학과 및 전공 일반대학원 신경과학기술과정
- 본문언어 영어
초록/요약
Evidence has accumulated suggesting that an altered iron metabolism may play an important role in neuronal injury under pathological conditions. The present study was undertaken to evaluate the possibility that iron mediates oxidative stress and delayed neuronal death in the hippocampal CA1 layer following transient forebrain ischemia for 10 minutes. Mitochondrial free radicals were generated in a biphasic pattern in the CA1 pyramidal neurons at 0.5 - 8 hours and 48 - 60 hours after reperfusion. The late free radical production was accompanied by iron accumulation and blocked by administration of deferoxamine, an iron chelator, or Neu2000, a potent antioxidant derived from aspirin and sulfasalazine. The neuroprotective effect of Neu2000 occurred even when it was delivered 24 hours after reperfusion. The iron accumulation was attributable to upregulation of transferrin receptors in the CA1 neurons and increased iron uptake from the blood. The iron accumulation was not observed in rats with leukopenia following peripheral body x-irradiation excluding the brain. Transient forebrain ischemia also induced an increase in permeability of the blood-brain-barrier and the infiltration of blood inflammatory cells. These present findings suggest that iron transport and deposit mediate the delayed free radical production and neuronal death following transient forebrain ischemia.
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ABSTRACT = i
TABLE OF CONTENTS = iii
LIST OF FIGURES = vi
LIST OF TABLES = viii
ABBREVIATION = ix
I. INTRODUCTION = 1
A. Overview = 1
B. Proposed mechanisms of CA1 neuronal death following TFI = 3
C. Role of iron = 6
D. Aims of study = 10
II. MATERIALS AND METHODS = 11
A. MATERIALS = 11
1. Animals = 11
2. Drugs = 11
3. Reagents = 11
4. Antibodies = 12
B. METHODS = 13
1. Transient forebrain ischemia and drug treatment = 13
2. Apoptotic neuronal death induction by intraventricular injection of colchicine in vivo = 14
3. Tissue preparation for histology = 14
4. Analysis of neuronal injury and quantification for survival cell number of CA1 = 15
5. In situ detection and analysis of intracellular free radical generation = 15
6. Immunohistochemistry = 16
7. Analysis of BBB permeability = 17
8. Iron histochemistry = 17
9. Zinc staining = 18
10. X - ray irradiation = 19
11. Blood chemistry for iron and transferrin of serum = 19
12. Primary cortical cell cultures = 19
13. LDH assay = 20
14. Statistical analysis = 20
III. RESULTS = 21
1. Necrosis of the CA1 neurons after TFI = 21
2. ROS production in the CA1 neurons following TFI = 23
3. Oxidative damage in the CA1 neurons following TFI = 26
4. Antioxidants attenuate ROS production and DND following TFI = 28
5. Iron accumulation in the CA1 neurons following TFI = 32
6. Upregulation of transferrin receptor and ferritin following TFI = 34
7. Deferoxamine prevents ROS production and DND after TFI = 37
8. The effect of deferoxamine is selective to iron neurotoxicity = 41
9. Increased BBB permeability following TFI = 44
10. Iron transport into the brain from the blood following TFI = 46
11. The reduction of iron uptake by x - irradiation = 49
IV. DISCUSSION = 53
V. CONCLUSION = 59
REFERENCES = 61
