Cortical synaptosomal proteomics study in autistic-like mouse models with different genes knocked out

Synaptic dysfunction is thought to be an important factor in triggering autism spectrum disorder (ASD), many ASD-related genes have been found to be associated with it; however, the pathological mechanisms of how these genes affect synaptic function and trigger ASD have yet to be clearly established. Here, <i>CNTN4</i>, <i>SAPAP3</i> and <i>SHANK3</i> were selected as genes to be tested, we performed SWATH proteomics to investigate the proteomes of the cerebral cortex and cerebral cortical synaptosomes of the mice with genes knocked out, respectively. The results showed that the deletion of the genes induced autistic-like behavior in mice, and changes in the expression of numerous neuron-associated proteins, compared to the control group. The alternation of synaptic plasticity, glutamatergic synapse, GABAergic synapse and various signaling pathways were identified in the enrichment analysis. Common proteins in all three proteomics were dominated by postsynaptic-associated proteins, indicating that restricted synaptic signaling needed to be focused on, which was also verified by transmission electron microscope observations. In conclusion, our proteomics studies indicated <i>CNTN4</i>, <i>SAPAP3</i> and <i>SHANK3</i> have important effects on synaptic growth and development as well as synaptic plasticity.突触功能障碍被认为是诱发自闭症谱系障碍（Autism Spectrum Disorder, ASD）的关键致病因素之一，目前已有多项研究证实众多自闭症相关基因与该病理过程密切相关；然而，此类基因如何调控突触功能并诱发自闭症谱系障碍的具体分子病理机制仍有待进一步明确阐释。本研究选取<i>CNTN4</i>、<i>SAPAP3</i>及<i>SHANK3</i>作为待测基因，采用SWATH蛋白质组学技术，分别对基因敲除小鼠的大脑皮层及大脑皮层突触小体的蛋白质组进行分析。实验结果显示，与对照组相比，上述基因的敲除可诱导小鼠产生类自闭症行为，并导致大量神经元相关蛋白的表达水平发生显著改变。富集分析结果表明，突触可塑性、谷氨酸能突触、γ-氨基丁酸能突触及多条信号通路均出现明显异常。三个蛋白质组共有的差异蛋白均以突触后相关蛋白为主，提示我们需重点关注突触信号传递受限的过程，该结论亦通过透射电子显微镜观察得到验证。综上，本蛋白质组学研究证实，<i>CNTN4</i>、<i>SAPAP3</i>及<i>SHANK3</i>对突触的生长发育及突触可塑性均具有重要调控作用。