Purkinje neurons with loss of STIM1 exhibit age-dependent changes in gene expression and synaptic components

The Stromal interaction molecule 1 (STIM1) is an ER-Ca2+ sensor and an essential component of ER-Ca2+ store operated Ca2+entry (SOCE). Loss of STIM1 affects metabotropic Glutamate Receptor 1 (mGluR1) mediated synaptic transmission, neuronal Ca2+ homeostasis and intrinsic plasticity in Purkinje Neurons (PNs). Long-term changes of intracellular Ca2+ signaling in PNs lead to neurodegenerative conditions, as evident in individuals with mutations of the ER-Ca2+ channel, the Inositol, 1,4,5-triphosphate receptor (IP3R). Moreover, Changes in gene expression upon reduced SOCE in non-excitable immune cells, the developing mouse brain, Drosophila pupal neurons and human neural precursor cells have been reported. Gene expression profiles of mature differentiated neurons with loss of STIM1/nSOC have not been published to date. The study evaluated the differential gene expression in STIM1 knockout purkinje neurons compared to wild type purkinje neurons from 1 year old mice. Analysis of gene expression profiles demonstrated that STIM1 dependent Ca2+ homeostasis and signaling helps to maintain the expression of multiple key components of synaptic architecture and function in ageing animals. Our findings are significant in the context of finding new therapeutic means of alleviating the neurodegenerative changes associated with human SCAs. RNA isolated from the microdissected purkinje neuronal layer and molecular layer followed by RNA sequencing using Illumina Hiseq 2500 platform. Three biological replicates each of wild type and STIM1 knockout purkinje neurons of 1 year old mice was used for the experiment.基质相互作用分子1（Stromal interaction molecule 1, STIM1）是内质网钙离子感受器（ER-Ca²⁺ sensor），同时也是内质网钙池操控性钙内流（ER-Ca²⁺ store operated Ca²⁺ entry, SOCE）的必需组成成分。STIM1的缺失会影响代谢型谷氨酸受体1（metabotropic Glutamate Receptor 1, mGluR1）介导的突触传递、神经元钙离子稳态以及浦肯野神经元（Purkinje Neurons, PNs）的内在可塑性。浦肯野神经元内细胞内钙离子信号的长期改变会引发神经退行性病变，这在内质网钙离子通道——肌醇1,4,5-三磷酸受体（Inositol 1,4,5-triphosphate receptor, IP3R）突变的个体中已有明确佐证。此外，已有研究报道了非兴奋性免疫细胞、发育中小鼠脑、果蝇蛹神经元以及人类神经前体细胞中SOCE降低后的基因表达变化情况。截至目前，尚未有关于STIM1/nSOC缺失的成熟分化神经元的基因表达谱相关研究发表。本研究对比分析了1岁小鼠STIM1敲除浦肯野神经元与野生型浦肯野神经元的差异基因表达情况。基因表达谱分析结果显示，STIM1依赖的钙离子稳态与信号通路，可维持衰老动物体内突触结构与功能的多个关键组分的表达水平。本研究结果对于发掘缓解人类SCAs相关神经退行性改变的新型治疗策略具有重要价值。实验过程为：从显微切割获取的浦肯野神经元层与分子层中分离总RNA，随后采用Illumina HiSeq 2500平台进行RNA测序。本实验共设置3组生物学重复，每组分别对应1岁小鼠的野生型与STIM1敲除浦肯野神经元。