白细胞介素-1对新生大鼠内耳毛细胞再生能力的影响

Effect of IL-1 on the regeneration of the inner ear hair cells in newborn rats

目的通过在新生SD大鼠毛细胞培养液中加入P27抑制剂白细胞介素-1(IL-1),观察IL-1介导的细胞周期蛋白依赖性激酶/细胞周期蛋白D(CDK4/cyclinD)复合体表达增强对毛细胞再生能力的影响。方法提取16只7 d龄SD大鼠的内耳基底膜上皮细胞层,按数字表法随机分为对照组(8只)和IL-1组(8只),离体培养。观察培养第7天、第14天细胞生长情况,通过免疫组织化学方法检测毛细胞内CDK4、cyclinD的表达。结果培养第7天,40倍光镜下3个随机视野内IL-1组毛细胞细胞球数量(139.33±13.50)个,与对照组[(69.00±12.49)个]相比明显增多,差异有统计学意义(P<0.05);培养第14天,毛细胞细胞球数量仍然有增多趋势,但与对照组相比差异无统计学意义(P>0.05)。免疫组织化学结果显示,IL-1组毛细胞内CDK4和cyclinD表达增强,与对照组相比差异均有统计学意义(P<0.05);CDK4和cyclinD阳性细胞率[分别为(48.23±8.87)%和(28.43±1.34)%]增高,与对照组[分别为(35.03±1.94)%和(17.43±2.20)%]相比差异均有统计学意义(P<0.05)。结论 IL-1可能对新生大鼠毛细胞的再生有一定的促进作用。

Objective To observe the effect of enhanced expression of CDK4/cyclinD complex on the regeneration of hair cells in newborn rats through addition of P27 inhibitor IL-1 into the culture. Methods The epithelium collected from the supporting membrane of the inner ear in the 167 day old rats were cultured in vitro and the animals were divided into 2 groups： the blank control group and the IL-1 group,each consisting of 8 rats. Cell growth was observed respectively at day 7 and day 14,and the expressions of CDK4 and cyclinD in hair cells were detected by immunohistochemistry. Results At day 7 after culture,the number of cell balls of hair cells（ 139. 33 ±13. 50） in the IL-1 group increased significantly in 3 randomized visual fields under the electron light microscope,when it was compared with that of the blank control group（ 69. 00 ± 12. 49）,and statistical significance could be noticed,when comparisons were made between them（ P〈0. 05）. At day 14 after culture,the number of cell balls of hair cells still displayed an increasing trend,but without statistical significance（ P〉0. 05）. Immunohistochemistry revealed that the expressions of CDK4 and cyclinD（ 76. 77 ± 6. 49 and 77. 04 ± 7. 89） in hair cells of the IL-1 group were enhanced,but without statistical significance（ P〉0. 05）,as compared with those of the control group（ P〉0.05）. Positive rates of CDK4 and cyclinD were respectively increased（ 48.23 ±8.87 and 28.43 ±1.34）,and statistical significance could be seen,as compared with those [（ 35. 03 ± 1. 94） % and（ 17. 43 ± 2. 20） %] of the control group,with statistical significance（ P〉0. 05）. Conclusion IL-1 might have a certain enhancing effect on the regeneration of hair cells in newborn rats.