Expression of calcium/calAulin kinaseIIα in fragile X mental retardation 1 gene knockout brain tissues in mice

Abstract

Objective To observe the expression of calcium/calAulin kinaseⅡα (CaMKⅡα) in the brain tissues of fragile X mental retardation 1 (FMR1) gene knockout (KO) mice to investigate whether CaMKⅡα is regulated by fragile X mental retardation protein (FMRP).Methods According to the gene types of the FVB inbred mice identified by PCR,20 mice were divided into KO group and WT (wide type) group (n=10).The subcellular distribution and expression of CaMKⅡα were observed by immunohistochemical staining; the mean optical density (A) values of immunostaining signal of CaMKⅡα in various brain regions,including the motor cortex,temporal cortex,amygdala,hypothalamus and hippocampus,were determined by IBAS 2.0 image-analyzed system.Results CaMKⅡα immunoreactive cells were abundantly found in all brain subregions of KO and WT mice; especial positive signal was noted in the proximal processes of neurons,so as to those in the dendrite; week signcal was observed in the axon.No distributional difference was found between KO and WT mice.As compared with those in the WT mice,the A values were distinctly increased in each brain region of KO mice with significant differences (P＜0.05).Conclusion The increased expression of CaMKⅡα in the brain tissues of FMR1 knockout mice hints that CaMKⅡα participates in the course of the fragile X syndrome,and FMRP may negatively regulate the expression of CaMKⅡα in physiological condition. Key words: Fragile X mental retardation 1 gene; Fragile X mental retardation protein; Calcium/calAulin kinaseⅡα