División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, México.
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
J Cell Physiol. 2017 Oct;232(10):2610-2615. doi: 10.1002/jcp.25827. Epub 2017 Mar 27.
Amyotrophic lateral sclerosis is a fatal neurodegenerative disease and studies in vitro show that motoneuron degeneration is triggered by non-cell-autonomous mechanisms. However, whether soluble toxic factor(s) released by mutant superoxide dismutase 1 (SOD1) expressing astrocytes induces death of motoneurons and leads to motor dysfunction in vivo is not known. To directly test this, healthy adult rats were treated with conditioned media derived from primary mouse astrocytes (ACM) that express human (h) SOD1 (ACM-hG93A) via chronic osmotic pump infusion in the lumbar spinal cord. Controls included ACM derived from transgenic mice expressing hSOD1 (ACM-hWT) or non-transgenic mouse SOD1 (ACM-WT) astrocytes. Rats chronically infused with ACM-hG93A started to develop motor dysfunction at 8 days, as measured by rotarod performance. Additionally, immunohistochemical analyses at day 16 revealed reactive astrogliosis and significant loss of motoneurons in the ventral horn of the infused region. Controls did not show significant motor behavior alterations or neuronal damage. Thus, we demonstrate that factors released in vitro from astrocytes derived from ALS mice cause spinal motoneuron death and consequent neuromuscular dysfunction in vivo.
肌萎缩侧索硬化症是一种致命的神经退行性疾病，体外研究表明，运动神经元的退化是由非细胞自主机制引发的。然而，突变型超氧化物歧化酶 1（SOD1）表达的星形胶质细胞释放的可溶性毒性因子是否会诱导运动神经元死亡，并导致体内运动功能障碍尚不清楚。为了直接验证这一点，健康成年大鼠通过慢性渗透泵在腰脊髓内输注表达人 SOD1（hG93A）的原代小鼠星形胶质细胞（ACM）的条件培养基进行处理。对照组包括表达 hSOD1（hWT）或非转基因小鼠 SOD1（WT）的星形胶质细胞 ACM。用 ACM-hG93A 慢性输注的大鼠在第 8 天开始出现运动功能障碍，通过转棒性能进行测量。此外，在第 16 天的免疫组织化学分析显示，在输注区域的腹角中出现反应性星形胶质增生和运动神经元的显著丢失。对照组没有表现出明显的运动行为改变或神经元损伤。因此，我们证明了从 ALS 小鼠来源的星形胶质细胞体外释放的因子会导致脊髓运动神经元死亡，并导致体内的神经肌肉功能障碍。
