Neuroinflammation, Signaling and Neuroregeneration Group, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal.
Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal.
Int J Mol Sci. 2021 Jun 7;22(11):6128. doi: 10.3390/ijms22116128.
miRNA(miR)-124 is an important regulator of neurogenesis, but its upregulation in SOD1G93A motor neurons (mSOD1 MNs) was shown to associate with neurodegeneration and microglia activation. We used pre-miR-124 in wild-type (WT) MNs and anti-miR-124 in mSOD1 MNs to characterize the miR-124 pathological role. miR-124 overexpression in WT MNs produced a miRNA profile like that of mSOD1 MNs (high miR-125b; low miR-146a and miR-21), and similarly led to early apoptosis. Alterations in mSOD1 MNs were abrogated with anti-miR-124 and changes in their miRNAs mostly recapitulated by their secretome. Normalization of miR-124 levels in mSOD1 MNs prevented the dysregulation of neurite network, mitochondria dynamics, axonal transport, and synaptic signaling. Same alterations were observed in WT MNs after pre-miR-124 transfection. Secretome from mSOD1 MNs triggered spinal microglia activation, which was unno-ticed with that from anti-miR-124-modulated cells. Secretome from such modulated MNs, when added to SC organotypic cultures from mSOD1 mice in the early symptomatic stage, also coun-teracted the pathology associated to GFAP decrease, PSD-95 and CX3CL1-CX3CR1 signaling im-pairment, neuro-immune homeostatic imbalance, and enhanced miR-124 expression levels. Data suggest that miR-124 is implicated in MN degeneration and paracrine-mediated pathogenicity. We propose miR-124 as a new therapeutic target and a promising ALS biomarker in patient sub-populations.
miRNA(miR)-124 是神经发生的重要调节因子，但在 SOD1G93A 运动神经元（mSOD1 MNs）中的上调与神经退行性变和小胶质细胞激活有关。我们在野生型（WT）MNs 中使用 pre-miR-124，在 mSOD1 MNs 中使用 anti-miR-124，以表征 miR-124 的病理作用。WT MNs 中 miR-124 的过表达产生了类似于 mSOD1 MNs 的 miRNA 谱（高 miR-125b；低 miR-146a 和 miR-21），并同样导致早期细胞凋亡。anti-miR-124 可消除 mSOD1 MNs 的改变，并且它们的 miRNA 变化主要由其分泌组重构。mSOD1 MNs 中 miR-124 水平的正常化可防止神经突网络、线粒体动力学、轴突运输和突触信号的失调。在 pre-miR-124 转染后的 WT MNs 中观察到相同的改变。mSOD1 MNs 的分泌组可触发脊髓小胶质细胞激活，而用 anti-miR-124 调节的细胞则不会发生这种情况。从小鼠 mSOD1 的早期症状阶段的 SC 器官型培养物中添加这种调节后的 MNs 的分泌组，也可对抗与 GFAP 减少、PSD-95 和 CX3CL1-CX3CR1 信号受损、神经免疫稳态失衡以及增强的 miR-124 表达水平相关的病理。数据表明，miR-124 参与 MN 退化和旁分泌介导的致病性。我们提出 miR-124 作为新的治疗靶标和 ALS 患者亚群中的有前途的生物标志物。
