Institute of Human Genetics, University of Cologne, 50931 Cologne, Germany.
Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany.
Int J Mol Sci. 2023 Feb 20;24(4):4198. doi: 10.3390/ijms24044198.
For SMA patients with only two copies, available therapies might be insufficient to counteract lifelong motor neuron (MN) dysfunction. Therefore, additional SMN-independent compounds, supporting SMN-dependent therapies, might be beneficial. Neurocalcin delta (NCALD) reduction, an SMA protective genetic modifier, ameliorates SMA across species. In a low-dose -ASO-treated severe SMA mouse model, presymptomatic intracerebroventricular (i.c.v.) injection of -ASO at postnatal day 2 (PND2) significantly ameliorates histological and electrophysiological SMA hallmarks at PND21. However, contrary to -ASOs, -ASOs show a shorter duration of action limiting a long-term benefit. Here, we investigated the longer-term effect of -ASOs by additional i.c.v. bolus injection at PND28. Two weeks after injection of 500 µg -ASO in wild-type mice, NCALD was significantly reduced in the brain and spinal cord and well tolerated. Next, we performed a double-blinded preclinical study combining low-dose -ASO (PND1) with 2× i.c.v. -ASO or CTRL-ASO (100 µg at PND2, 500 µg at PND28). -ASO re-injection significantly ameliorated electrophysiological defects and NMJ denervation at 2 months. Moreover, we developed and identified a non-toxic and highly efficient human -ASO that significantly reduced NCALD in hiPSC-derived MNs. This improved both neuronal activity and growth cone maturation of SMA MNs, emphasizing the additional protective effect of -ASO treatment.
对于只有两个拷贝的 SMA 患者，可用的治疗方法可能不足以抵消终生运动神经元 (MN) 功能障碍。因此，支持 SMN 依赖性治疗的额外 SMN 非依赖性化合物可能是有益的。神经钙蛋白 delta (NCALD) 减少是一种 SMA 保护性遗传修饰因子，可改善多种物种的 SMA。在低剂量 ASO 治疗的严重 SMA 小鼠模型中，在出生后第 2 天 (PND2) 进行预防性脑室内 (i.c.v.) ASO 注射可显著改善 PND21 时的组织学和电生理学 SMA 特征。然而，与 ASO 相反，ASO 的作用持续时间较短，限制了长期获益。在这里，我们通过在 PND28 时进行额外的 i.c.v. 推注来研究 ASO 的长期效果。在野生型小鼠中注射 500µg ASO 两周后，NCALD 在大脑和脊髓中的表达显著降低，且耐受性良好。接下来，我们进行了一项双盲临床前研究，将低剂量 ASO（PND1）与 2×i.c.v. ASO 或对照 ASO（PND2 时 100µg，PND28 时 500µg）联合使用。ASO 再注射可显著改善 2 个月时的电生理缺陷和 NMJ 去神经支配。此外，我们开发并鉴定了一种非毒性且高效的人 ASO，可显著降低 hiPSC 衍生 MN 中的 NCALD。这既改善了 SMA MN 的神经元活性，又改善了生长锥成熟，强调了 ASO 治疗的额外保护作用。
