微管相关蛋白1B在Fmr1基因敲除小鼠脑组织内的表达变化(英文)

目的探讨脆性X智能低下蛋白(fragile X mental retardation protein,FMRP)对微管相关蛋白1B(microtubuleassociated protein 1B,MAP1B)是否具有调控作用。方法应用免疫组化、免疫印记和原位杂交的方法,对1周龄和6周龄的Fmr1基因敲除型(KO)和同龄野生型(WT)小鼠脑组织MAP1B及MAP1B mRNA进行分析。结果免疫组化的结果显示 :6周龄KO小鼠各个脑区MAP1B的平均光密度值(MOD)值均显著低于同龄WT小鼠(P < 0.05),1周龄KO小鼠仅在小脑和海马显著降低(P < 0.01) ;各脑区MAP1B的MOD值在6周龄小鼠均比同基因型的1周龄小鼠显著降低(P < 0.05)。免疫印记和原位杂交结果分别显示MAP1B及MAP1B mRNA在KO小鼠的海马组织均显著降低(P <0.05)。结论MAP1B和MAP1B mRNA在Fmr1基因敲除小鼠脑组织的表达均显著减少,提示FMRP 可能正性调节MAP1B的表达。

Expression changes of microtubule associated protein 1B in the brain of Fmr1 knockout mice

Objective To explore the regulatory effect of fragile X mental retardation protein (FMRP) on the translation of microtubule associated protein 1B (MAP1B). Methods The expressions of MAP1B protein and MAP1B mRNA in the brains of 1-week and 6-week old fragile X mental retardation-1 (Fmr1) knockout (KO) mice were investigated by immunohistochemistry, Western blot, and in situ hybridization, with the age-matched wild type mice (WT) as controls. Results The mean optical density (MOD) of MAP1B was significantly decreased in each brain region in KO6W compared with WT6W, whereas in KO1W, this decrease was only found in the hippocampus and cerebellum. MAP1B in 6-week mice was much less than that in 1-week mice of the same genotype. The results of Western blot and in situ hybridization showed that MAP1B protein and MAP1B mRNA were significantly decreased in the hippocampus of both KO1W and KO6W. Conclusion The decreased MAP1B protein and MAP1B mRNA in the Fmr1 knockout mice indicate that FMRP may positively regulate the expression of MAP1B.