Modeling the differential phenotypes of spinal muscular atrophy with high-yield generation of motor neurons from human induced pluripotent stem cells
Metrics: PDF 1755 views | HTML 2775 views | ?
Xiang Lin1,*, Jin-Jing Li1,*, Wen-Jing Qian2,*, Qi-Jie Zhang1, Zhong-Feng Wang2, Ying-Qian Lu1, En-Lin Dong1, Jin He1, Ning Wang1, Li-Xiang Ma3 and Wan-Jin Chen1,4
1Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China
2Institutes of Brain Science, Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
3Department of Anatomy, Histology & Embryology, Shanghai Medical College, Fudan University, Shanghai 200032, China
4Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
*These authors have contributed equally to this work
Wan-Jin Chen, email: email@example.com
Li-Xiang Ma, email: firstname.lastname@example.org
Keywords: spinal muscular atrophy (SMA), induced pluripotent stem cells (iPSCs) derived enriched motor neurons (MNs), survival motor neuron (SMN) protein, neurite outgrowth, neuronal activity
Received: August 20, 2016 Accepted: December 27, 2016 Published: January 31, 2017
Spinal muscular atrophy (SMA) is a devastating motor neuron disease caused by mutations of the survival motor neuron 1 (SMN1) gene. SMN2, a paralogous gene to SMN1, can partially compensate for the loss of SMN1. On the basis of age at onset, highest motor function and SMN2 copy numbers, childhood-onset SMA can be divided into three types (SMA I-III). An inverse correlation was observed between SMN2 copies and the differential phenotypes of SMA. Interestingly, this correlation is not always absolute. Using SMA induced pluripotent stem cells (iPSCs), we found that the SMN was significantly decreased in both SMA III and SMA I iPSCs derived postmitotic motor neurons (pMNs) and γ-aminobutyric acid (GABA) neurons. Moreover, the significant differences of SMN expression level between SMA III (3 copies of SMN2) and SMA I (2 copies of SMN2) were observed only in pMNs culture, but not in GABA neurons or iPSCs. From these findings, we further discovered that the neurite outgrowth was suppressed in both SMA III and SMA I derived MNs. Meanwhile, the significant difference of neurite outgrowth between SMA III and SMA I group was also found in long-term cultures. However, significant hyperexcitability was showed only in SMA I derived mature MNs, but not in SMA III group. Above all, we propose that SMN protein is a major factor of phenotypic modifier. Our data may provide a new insight into recognition for differential phenotypes of SMA disease.
All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.