NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA; Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA.
NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA.
Biomaterials. 2022 Oct;289:121752. doi: 10.1016/j.biomaterials.2022.121752. Epub 2022 Aug 19.
There is evidence for the involvement of human skeletal muscle (hSKM) in ALS neuromuscular junction (NMJ) dysfunction. However, the specific avenue by which the hSKM contributes to NMJ disruption is not well understood due to limited human-based studies performed to investigate the subject. Thus, hSKM and human motoneurons (hMN) generated from induced pluripotent stem cells of healthy individuals (WT) and ALS patients with two different SOD1 mutations were integrated into functional NMJ systems to investigate and compare the pathological contribution of the hSKM and hMN to ALS NMJ disruption. Morphological assessment of ALS NMJs demonstrated reduced acetylcholine receptor clustering in the post-synaptic membrane of co-cultures with ALS hSKM (hSKM-hMN and hSKM-hMN). Significantly reduced functional NMJ numbers, NMJ stability, contraction fidelity and increased fatigue index were observed in all ALS co-cultures compared to WT. However, these disease phenotypes were comparatively more severe in microphysiologic systems with hSKM-hMN or hSKM-hMN than those with hSKM-hMN co-cultures. Results from this study affirm that the inherent pathological defects in ALS hSKM, independent of motoneurons, significantly contributes to NMJ dysfunction. As such, therapeutically targeting the ALS hSKM may be just as, if not more critical than, the hMN in alleviating disease phenotypes and attenuating disease progression.
有证据表明，人类骨骼肌（hSKM）参与了肌萎缩侧索硬化症（ALS）神经肌肉接头（NMJ）功能障碍。然而，由于进行了有限的基于人类的研究来调查这一主题，因此尚不清楚 hSKM 具体通过何种途径导致 NMJ 破坏。因此，将来自健康个体（WT）和患有两种不同 SOD1 突变的 ALS 患者的诱导多能干细胞生成的 hSKM 和 hMN 整合到功能性 NMJ 系统中，以研究和比较 hSKM 和 hMN 对 ALS NMJ 破坏的病理贡献。对 ALS NMJ 的形态学评估表明，在与 ALS hSKM（hSKM-hMN 和 hSKM-hMN）共培养的突触后膜中，乙酰胆碱受体聚集减少。与 WT 相比，所有 ALS 共培养物中 NMJ 的数量、NMJ 的稳定性、收缩保真度和疲劳指数均显著降低。然而，在具有 hSKM-hMN 或 hSKM-hMN 的微生理系统中，这些疾病表型比具有 hSKM-hMN 共培养物的系统更为严重。这项研究的结果证实，ALS hSKM 的固有病理缺陷，独立于运动神经元，显著导致 NMJ 功能障碍。因此，针对 ALS hSKM 的治疗方法可能与针对 hMN 的治疗方法同样重要，甚至更为重要，以减轻疾病表型和减缓疾病进展。
