The Molecular Mechanism Of Capicua Regulating Dendritic Growth Of Hippocampal Neurons In Vitro

BACKGROUND:The structure of neuronal dendrites and dendritic spines is very important to the function of neurons.Numerous studies show that the structural abnormalities of dendrites and their connections can cause many neurodevelopmental disorders,such as schizophrenia,bipolar disorder,autism spectrum disorder and intellectual disorder.The abnormal structure of dendritic spines is also a prominent feature of Alzheimer’s disease,Parkinson’s disease and traumatic brain injury.Therefore,it is necessary to clarify the mechanism of dendritic and dendritic spine abnormalities in nervous system diseases.During the growth and development of neurons,the morphology of neuronal dendrites and dendritic spines is coordinated and controlled by external regulatory factors and internal genetic control program.External factors include secreted neurotrophic factors,cell adhesion molecules and activity dependent calcium signals,while internal genetic programs include transcription factors,cytoskeletal regulatory factors and motor proteins,as well as secretory membrane pathways and regulatory RNA.As an important internal genetic regulator,transcription factor can control the whole development process of neurons and respond to the changes of external environmental signals.Capicua(CIC),as a transcriptional negative regulator of HMG box family,was first found in Drosophila.In Drosophila,it can control receptor tyrosine kinase(RTK)/ Ras / ERK signaling pathway,and then affect embryonic development.Previous studies have shown that CIC is highly expressed in the central nervous system,especially in the hippocampus and cortex.Lu et al.used Emx1 CRE allele mice to specifically knock out mouse telencephalon CIC,which led to defects in dendritic branches in mouse layer 2 and 3 cortical vertebral neurons,while no difference in dendritic branch complexity was observed in layer 5 cortical vertebral neurons,indicating that transcription factor CIC has different functions in different brain regions or different neurons.At present,there is no research on CIC regulating dendritic and dendritic spines of hippocampal neurons.Expounding the function and mechanism of CIC in dendrites and dendritic spines of hippocampal neurons can provide potential targets for neurodevelopmental disorders.OBJECTIVE:To explore the expression of transcription inhibitor CIC in central nervous system;To explore the role of CIC in hippocampal neurons;To explore the molecular mechanism of regulating dendritic growth of hippocampal neurons in vitro.METHODS:1.Detect the expression distribution and specificity of Capicua in the hippocampus of the central nervous system by immunofluorescence and immunoblotting;2.Detect the effect of Capicua on the growth of hippocampal neuron dendrites by constructing over-expression and knock-down Capicua;3.By immunization Blotting,QPCR,immunofluorescence and other methods were used to detect the mechanism of Capicua regulating the growth of hippocampal neuron dendrites.RESULTS:1.Capicua is highly expressed in the central nervous system,especially the cerebral cortex and hippocampus;2.Capicua is expressed in central nervous system brain neurons,glial cells and microglia;3.Capicua is highly expressed in the vertebral body of hippocampal neurons Cells;4.Knockdown of endogenous Capicua of hippocampal neurons promotes the growth of neuronal dendritic spines;5.Overexpression of Capicua in hippocampal neurons inhibits the growth of meridian dendrites and dendritic spines;6.Inhibits hippocampus The expression of Ets factor in neurons;7.Knockdown of Ets in hippocampal neurons can reverse the effect of neuron dendritic growth caused by knocking down CIC.CONCLUSIONS:Capicua inhibits the morphogenesis of hippocampal neurons and the growth of dendritic spines through Ets in vitro.