Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which l...Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which leads to intellectual disability and social impairment. γ-aminobutyric acid （GABA） is the major inhibitory neuro- transmitter of the mammalian central nervous system, and its metabotropic GABAB receptor has been implicated in various mental disorders. The GABAB receptor agonist baclofen has been shown to improve FXS symptoms in a mouse model and in human patients, suggesting the role of GABAB receptor on FMRP regulation. Here we investi- gated the signaling events linking the GABAB receptor and FMRP. Methods Western blot was used in this study to detect protein expression and kinase phosphorylation in cerebellar granule neurons. For key molecules in signal- ling pathway, RNAi was used in MEFs to confirm the results in neurons. Results GABAB receptor activation up- regulated cAMP response element binding protein-dependent Fmrp expression in cultured mouse cerebellar granule neurons via two distinct mechanisms： the transactivation of insulin-like growth factor-1 receptor and activation of protein kinase C. In addition, a positive allosteric modulator of the GABAB receptor, CGP7930, stimulated Fmrp expression in neurons. Conclusion These results suggest a role for GABAB receptor in Fmrp regulation and a po- tential interest of GABAB receptor signaling in FXS improvement.展开更多
目的利用FMR1基因敲除小鼠,研究FMR1基因缺失对雌性小鼠生殖功能的影响,并对其影响机制进行探讨。方法将成年的KO纯合子、KO杂合子、WT雌鼠分别和成年的WT雄鼠合笼,观察合笼时间及产仔数;随机取10周的上述3种基因型雌鼠,HE染色观察卵巢...目的利用FMR1基因敲除小鼠,研究FMR1基因缺失对雌性小鼠生殖功能的影响,并对其影响机制进行探讨。方法将成年的KO纯合子、KO杂合子、WT雌鼠分别和成年的WT雄鼠合笼,观察合笼时间及产仔数;随机取10周的上述3种基因型雌鼠,HE染色观察卵巢形态;免疫组化测定NPY和GABA在下丘脑的分布,Image Pro Plus 6.0分析平均光密度值;ELISA测定血清NPY水平。结果 3组小鼠中,KO纯合子雌鼠的产仔数少于WT雌鼠(6.39±2.30)、(7.60±2.69)和(8.00±1.88);KO纯合子雌鼠的卵泡总数少于WT雌鼠(36.00±5)、(39.33±7.87)和(45.45±7.85);KO纯合子雌鼠下丘脑NPY的表达弱于WT雌鼠(0.27±0.016)、(0.29±0.04)和(0.31±0.041);血清NPY及下丘脑GABA的表达三组间差异均无显著性(P>0.05)。结论FMR1基因敲除可导致雌鼠生育功能下降,FMR1基因可能是通过下调NPY的表达来降低其生殖功能的。展开更多
文摘Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which leads to intellectual disability and social impairment. γ-aminobutyric acid （GABA） is the major inhibitory neuro- transmitter of the mammalian central nervous system, and its metabotropic GABAB receptor has been implicated in various mental disorders. The GABAB receptor agonist baclofen has been shown to improve FXS symptoms in a mouse model and in human patients, suggesting the role of GABAB receptor on FMRP regulation. Here we investi- gated the signaling events linking the GABAB receptor and FMRP. Methods Western blot was used in this study to detect protein expression and kinase phosphorylation in cerebellar granule neurons. For key molecules in signal- ling pathway, RNAi was used in MEFs to confirm the results in neurons. Results GABAB receptor activation up- regulated cAMP response element binding protein-dependent Fmrp expression in cultured mouse cerebellar granule neurons via two distinct mechanisms： the transactivation of insulin-like growth factor-1 receptor and activation of protein kinase C. In addition, a positive allosteric modulator of the GABAB receptor, CGP7930, stimulated Fmrp expression in neurons. Conclusion These results suggest a role for GABAB receptor in Fmrp regulation and a po- tential interest of GABAB receptor signaling in FXS improvement.
文摘目的利用FMR1基因敲除小鼠,研究FMR1基因缺失对雌性小鼠生殖功能的影响,并对其影响机制进行探讨。方法将成年的KO纯合子、KO杂合子、WT雌鼠分别和成年的WT雄鼠合笼,观察合笼时间及产仔数;随机取10周的上述3种基因型雌鼠,HE染色观察卵巢形态;免疫组化测定NPY和GABA在下丘脑的分布,Image Pro Plus 6.0分析平均光密度值;ELISA测定血清NPY水平。结果 3组小鼠中,KO纯合子雌鼠的产仔数少于WT雌鼠(6.39±2.30)、(7.60±2.69)和(8.00±1.88);KO纯合子雌鼠的卵泡总数少于WT雌鼠(36.00±5)、(39.33±7.87)和(45.45±7.85);KO纯合子雌鼠下丘脑NPY的表达弱于WT雌鼠(0.27±0.016)、(0.29±0.04)和(0.31±0.041);血清NPY及下丘脑GABA的表达三组间差异均无显著性(P>0.05)。结论FMR1基因敲除可导致雌鼠生育功能下降,FMR1基因可能是通过下调NPY的表达来降低其生殖功能的。
