TLR7 activation in epilepsy of tuberous sclerosis complex
TLR7 activation in epilepsy of tuberous sclerosis complex
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DOI：
10.1007/s00011-019-01283-3
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发表时间：
2019-12-01
影响因子：
6.7
通讯作者：
Chugani, Diane C.
中科院分区：
文献类型：
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作者：
Dombkowski, Alan A.;Cukovic, Daniela;Chugani, Diane C.
背景神经炎症和先天性免疫系统的Toll样受体(TLR)与癫痫有关。我们先前报道了在治疗儿童结节性硬化症(TSC)顽固性癫痫切除的致痫脑组织中高水平的microRNAs miR-142-3p和miR-223-3p。由于miR-142-3p最近被报道是TLR7的配体和激活剂，TLR7是外源性和内源性单链RNA的检测器，我们评估了TLR7在手术切除的TSC脑组织中的表达和下游IL23A的激活。方法对药物耐药癫痫患儿手术切除的皮质组织进行基因表达分析。纳米串计数法检测TLR2、TLR4和TLR7的表达。实时定量聚合酶链式反应证实TLR7的表达，并比较IL-23A和miR-142-3p水平所指示的TLR7的激活。使用我们现有的TSC组织定量蛋白质组学数据集的数据来评估TLR7激活的蛋白质标志物特征。用毛细管电泳法和免疫印迹法检测TLR7蛋白在部分样本中的表达。结果TLR7在TSC组织中均有转录表达。TLR7蛋白在各样品膜组分中均检测到信号转导活性形式。在临床神经影像显示神经炎症升高的致痫灶中，发现TLR7的下游激活。TLR7活性与组织miR-142-3p水平显著相关。结论TLR7的激活可能参与了TSC癫痫的神经炎症级联反应。对这一机制的进一步表征可能使神经成像和TLR7抑制剂的联合使用成为治疗难治性癫痫的个性化方法。
Background Neuroinflammation and toll-like receptors (TLR) of the innate immune system have been implicated in epilepsy. We previously reported high levels of microRNAs miR-142-3p and miR-223-3p in epileptogenic brain tissue resected for the treatment of intractable epilepsy in children with tuberous sclerosis complex (TSC). As miR-142-3p has recently been reported to be a ligand and activator of TLR7, a detector of exogenous and endogenous single-stranded RNA, we evaluated TLR7 expression and downstream IL23A activation in surgically resected TSC brain tissue. Methods Gene expression analysis was performed on cortical tissue obtained from surgery of TSC children with pharmacoresistent epilepsy. Expression of TLRs 2, 4 and 7 was measured using NanoString nCounter assays. Real-time quantitative PCR was used to confirm TLR7 expression and compare TLR7 activation, indicated by IL-23A levels, to levels of miR-142-3p. Protein markers characteristic for TLR7 activation were assessed using data from our existing quantitative proteomics dataset of TSC tissue. Capillary electrophoresis Western blots were used to confirm TLR7 protein expression in a subset of samples. Results TLR7 transcript expression was present in all TSC specimens. The signaling competent form of TLR7 protein was detected in the membrane fraction of each sample tested. Downstream activation of TLR7 was found in epileptogenic lesions having elevated neuroinflammation indicated by clinical neuroimaging. TLR7 activity was significantly associated with tissue levels of miR-142-3p. Conclusion TLR7 activation by microRNAs may contribute to the neuroinflammatory cascade in epilepsy in TSC. Further characterization of this mechanism may enable the combined of use of neuroimaging and TLR7 inhibitors in a personalized approach towards the treatment of intractable epilepsy.