雏鸡听毛细胞损伤后c-myc mRNA及其产物表达的研究

Study on c-myc mRNA and its product expression during hair cell regeneration in the chick basilar papilla

探讨ｃ－ｍｙｃ基因表达在雏鸡基底乳头（ｂａｓｉｌａｒ ｐａｐｉｌｌａ， ＢＰ）庆大霉素损伤后听毛细胞再生过程中的意义。方法：应用原位杂交和免疫组化技术检测庆大霉素停药后第 １，３，７，１４，２１和 ２８ ｄ时ＢＰ损伤区域ｃ－ｍｙｃ ｍＲＮＡ和 ｃ－ｍｙｃ蛋白表达情况。结果：ＢＰ修复过程中ｃ－ｍｙｃ ｍＲＮＡ和 ｃ－ｍｙｃ蛋白表达水平明显升高，修复 ７ｄ时表达水平达高峰，修复 １４ ｄ后ＢＰ中ｃ－ｍｙｃ基因表达水平开始下降。结论：提示ｃ－ｍｙｃ基因表达是毛细胞再生过程中的一个重要分子事件，可能与前体细胞增殖有关。

Objective:To study the effect of c-myc gene expression during hair cell (HC) regeneration in the chick basilar papilla (BP) following getamicin ototoxicity. Method: c-myc mRNA and its product (c-myc protein ) expression in the damaged region was histologicolly analyzed by in situ hybridization and immunohistochemistry. Thirty-six animals received one subcutaneous injection of gentamicin sulfate (5 0 mg /kg ) daily for ten days. The animals were allowed to survive 1, 3, 7, 14, 21 or 28 days (n=6 in each group) before sacrifice and preparation for both in situ hybridization and immunohistochemistry. Twelve animals were sacrificed as control for each groups (n=2). Result:The results showed that the supporting cells and cells in the lumenal nuclear layer within the damaged region were strongly labeled for c-myc transcripts and its protein. Seven days after last injection, the highest level of c-myc mRNA and c-myc protein expression was observed in the injured sensory epithelium. C-myc gene expression began to decline from fourteen days post injection. High level expression of c-myc gene was discussed in relation to the time and location of HC regeneration. Conclusion: The results indicate that c-mys gene expression may be an important molecular event in HC regeneration and may play a role in regulating progenitor cells proliferation.