조류 망막 발생 중 희소돌기아교세포에서 αB-crystallin의 특이적 발현 = Specific expression of αB-crystallin in oligodendrocytes during avian retinal development

다국어 초록 (Multilingual Abstract)

Purpose: It is well known that expression of αB-crystallin is increased in neurons, oligodendrocytes and astrocytes in the pathologic condition. However, αB-crystallin expression during normal development of the central nervous system has not been reported. This study aims to clarify that αB-crystallin is expressed in mature myelinating oligodendrocytes in the neural retina, and to verify that expression of αB-crystallin plays a part of protective roles in myelinating oligodendrocytes against oxidative stress derived from free radical during myelin formation.
Method: During retinal development, alterations of iron concentration and expression of heat shock proteins including αB-crystallin were examined using Western blot and immunohistochemistry. To identify specific expression of αB-crystallin in mature myelinating oligodendrocytes, αB-crystallin was coupled with neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP), ricinus communis agglutinin 1 (RCA1) and transferrin binding protein (TfBP), or myelin basic protein (MBP).
Result: Iron concentration of the retina was increased from E14 to E20. Expression of αB-crystallin was first observed in the E16 retina. Thereafter, it was increased until E20. Alpha B-crystallin positive (+) cells first appeared in the optic nerve at E14, in the central retina at E16, and in the peripheral retina at E18. In comparison with E18, the number of αB-crystallin+ cells at E20 was increased in the central and the peripheral retina. Alpha B-crystallin-immunoreactivity (-IR) was spatiotemporally similar to MBP-IR. But, the difference was found in which MBP-IR was observed in the myelins rather than the cell bodies of oligodendrocytes after E14. Differential immunostain demonstrated that αB-crystallin was exclusively expressed in the mature myelinating oligodendrocyte. Besides, αB-crystallin was temporally expressed in the peripapillary glial cell.
Conclusion: Alpha B-crystallin was expressed in mature myelinating oligodendrocytes of the chick retina. With progress of myelination, concentration of iron which facilitates to produce free radicals was increased, suggesting that myelination may induce oxidative stress. Together with the reports that oligodendrocytes have low level of antioxidase and αB-crystallin plays a role as a molecular chaperone. Results of this study suggest that αB-crystallin may play a part of protective roles against oxidative stress in myelinating oligodendrocytes.

Key words: αB-crystallin, oligodendrocyte, oxidative stress, retina, iron, heat shock protein

목차 (Table of Contents)

• Ⅰ. 서 론 1
• Ⅱ. 재료 및 방법 5
• 1. 실험동물 5
• 2. 철농도 측정 5
• 3. Western blot 5
• 4. 조직절편제작 7
• 5. 면역조직화학염색 7
• 6. 이중면역형광염색 8
• Ⅲ. 결 과 10
• 1. 발생 단계별 망막의 철농도 10
• 2. 발생 후기 망막에서 열충격단백질의 발현 10
• 3. 발생 망막에서 αB-crystallin 발현 11
• 4. 발생 망막에서 myelin basic protein (MBP)의 발현 13
• 5. Alpha B-crystallin 면역반응세포의 동정 14
• Ⅳ. 고 찰 34
• Ⅴ. 결 론 39
• 참 고 문 헌 41