目的:本研究旨在通过使用全外显子组测序(WES)与非RE性癫痫(PWE)和对照病例相比,确定Rasmussen脑炎(RE)脑组织中的分子机制。RNAseq,和蛋白质组学。
方法:冷冻脑组织(年龄=2-19岁)来自对照尸检(n=14),手术PWE(n=10),和手术RE病例(n=27)。我们评估了与癫痫相关的RE中的WES变异,癫痫发作,RE,和人类白细胞抗原(HLA)。通过RNAseq(调整的p<.05)和无标记定量质谱(错误发现率<5%)评估三组中的差异表达。
结果:WES在RE中没有发现常见的致病变异,但有几种罕见且可能具有未知意义的有害变异(VUS;ANGPTL7/MTOR,SCN1A,FCGR3B,MTOR)和更常见的HLAVUS在>25%的RE病例(HLA-DRB1,HLA-DQA2),在一般人群中等位基因频率均<5%。RE与PWE中的RNAseq(1516种改变的转录本)揭示了树突状细胞和自然杀伤细胞之间串扰的显着激活(p=7.94×10-6,z=2.65),在RE与对照(7466转录本)神经炎症信号激活(p=6.31×10-13,z=5.07),在PWE与对照(945个转录本)中,吞噬体形成激活(p=2.00×10-13,z=5.61)。蛋白质组学检测到更少的改变的目标。
结论:在RE中,我们确定了激活的免疫信号通路和免疫细胞类型注释富集,提示先天和适应性免疫反应的作用,以及可能增加RE脆弱性的HLA变异。后续研究可以评估与顶级靶标相关的细胞类型密度和次区域定位,临床病史(神经病理学,疾病持续时间),以及调节树突状细胞和自然杀伤细胞之间的串扰是否可能限制疾病进展。
This study was undertaken to identify molecular mechanisms in brain tissue of Rasmussen encephalitis (RE) when compared to people with non-RE epilepsy (PWE) and control cases using whole exome sequencing (WES), RNAseq, and proteomics.
Frozen brain tissue (ages = 2-19 years) was obtained from control autopsy (n = 14), surgical PWE (n = 10), and surgical RE cases (n = 27). We evaluated WES variants in RE associated with epilepsy, seizures, RE, and human leukocyte antigens (HLAs). Differential expression was evaluated by RNAseq (adjusted p < .05) and label-free quantitative mass spectrometry (false discovery rate < 5%) in the three groups.
WES revealed no common pathogenic variants in RE, but several rare and likely deleterious variants of unknown significance (VUS; ANGPTL7/MTOR, SCN1A, FCGR3B, MTOR) and more common HLA VUS in >25% of RE cases (HLA-DRB1, HLA-DQA2), all with allele frequency < 5% in the general population. RNAseq in RE versus PWE (1516 altered transcripts) revealed significant activation of crosstalk between dendritic and natural killer cells (p = 7.94 × 10-6 , z = 2.65), in RE versus control (7466 transcripts) neuroinflammation signaling activation (p = 6.31 × 10-13 , z = 5.07), and in PWE versus control (945 transcripts) phagosome formation activation (p = 2.00 × 10-13 , z = 5.61). Proteomics detected fewer altered targets.
In RE, we identified activated immune signaling pathways and immune cell type annotation enrichment that suggest roles of the innate and adaptive immune responses, as well as HLA variants that may increase vulnerability to RE. Follow-up studies could evaluate cell type density and subregional localization associated with top targets, clinical history (neuropathology, disease duration), and whether modulating crosstalk between dendritic and natural killer cells may limit disease progression.