Shank2 is an excitatory postsynaptic scaffolding protein strongly implicated in autism spectrum disorders (ASDs). Shank2-mutant mice with a homozygous deletion of exons 6 and 7 (Shank2-KO mice) show decreased NMDA receptor (NMDAR) function and autistic-like behaviors at juvenile [∼postnatal day (P21)] and adult (>P56) stages that are rescued by NMDAR activation. However, at ∼P14, these mice show the opposite change – increased NMDAR function; moreover, suppression of NMDAR activity with early, chronic memantine treatment during P7–21 prevents NMDAR hypofunction and autistic-like behaviors at later (∼P21 and >P56) stages. To better understand the mechanisms underlying this rescue, we performed RNA-Seq gene-set enrichment analysis of forebrain transcriptomes from wild-type (WT) and Shank2-KO juvenile (P25) mice treated early and chronically (P7–21) with vehicle or memantine. Vehicle-treated Shank2-KO mice showed upregulation of synapse-related genes and downregulation of ribosome- and mitochondria-related genes compared with vehicle-treated WT mice. They also showed a transcriptomic pattern largely opposite that observed in ASD (reverse-ASD pattern), based on ASD-related/risk genes and cell-type–specific genes. In memantine-treated Shank2-KO mice, chromatin-related genes were upregulated; mitochondria, extracellular matrix (ECM), and actin-related genes were downregulated; and the reverse-ASD pattern was weakened compared with that in vehicle-treated Shank2-KO mice. In WT mice, memantine treatment, which does not alter NMDAR function, upregulated synaptic genes and downregulated ECM genes; memantine-treated WT mice also exhibited a reverse-ASD pattern. Therefore, early chronic treatment of Shank2-KO mice with memantine alters expression of chromatin, mitochondria, ECM, actin, and ASD-related genes.

Shank2 是一种兴奋性突触后支架蛋白，与自闭症谱系障碍 (ASD) 密切相关。 柄 2-外显子 6 和 7 纯合缺失的突变小鼠（柄 2-KO 小鼠）显示出降低的 NMDA 受体 (NMDAR) 功能和自闭症样行为，在通过 NMDAR 激活挽救的幼年 [∼产后 (P21)] 和成年 (>P56) 阶段。然而，在~P14，这些小鼠表现出相反的变化——NMDAR 功能增加；此外，在 P7-21 期间用早期、慢性美金刚治疗抑制 NMDAR 活性可防止 NMDAR 功能减退和后期（~P21 和 >P56）阶段的自闭症样行为。为了更好地理解这种拯救的机制，我们对野生型 (WT) 和前脑转录组进行了 RNA-Seq 基因集富集分析。柄 2-KO 幼年 (P25) 小鼠用载体或美金刚进行早期和长期 (P7-21) 治疗。车辆处理柄 2与载体处理的 WT 小鼠相比，-KO 小鼠表现出突触相关基因的上调和核糖体和线粒体相关基因的下调。基于 ASD 相关/风险基因和细胞类型特异性基因，他们还显示出与 ASD（反向 ASD 模式）大体相反的转录组模式。在美金刚处理柄 2-KO小鼠，染色质相关基因上调；线粒体、细胞外基质 (ECM) 和肌动蛋白相关基因被下调；与载体治疗相比，反向 ASD 模式减弱柄 2-KO 老鼠。在 WT 小鼠中，美金刚治疗不会改变 NMDAR 功能，上调突触基因和下调 ECM 基因；美金刚处理的 WT 小鼠也表现出反向 ASD 模式。因此，早期慢性治疗柄 2- 使用美金刚胺的 KO 小鼠会改变染色质、线粒体、ECM、肌动蛋白和 ASD 相关基因的表达。