Prenatal transplantation of human amniotic fluid stem cell could improve clinical outcome of type III spinal muscular atrophy in mice

AbstractSpinal muscular atrophy (SMA) is a single gene disorder affecting motor function in uterus. Amniotic fluid is an alternative source of stem cell to ameliorate SMA. Therefore, this study aims to examine the therapeutic potential of Human amniotic fluid stem cell (hAFSC) for SMA. Our SMA model mice were generated by deletion of exon 7 of Smn gene and knock-in of human SMN2. A total of 16 SMA model mice were injected with 1 × 105 hAFSC in uterus, and the other 16 mice served as the negative control. Motor function was analyzed by three behavioral tests. Engraftment of hAFSC in organs were assessed by flow cytometry and RNA scope. Frequency of myocytes, neurons and innervated receptors were estimated by staining. With hAFSC transplantation, 15 fetuses survived (93.75% survival) and showed better performance in all motor function tests. Higher engraftment frequency were observed in muscle and liver. Besides, the muscle with hAFSC transplantation expressed much laminin α and PAX-7. Significantly higher frequency of myocytes, neurons and innervated receptors were observed. In our study, hAFSC engrafted on neuromuscular organs and improved cellular and behavioral outcomes of SMA model mice. This fetal therapy could preserve the time window and treat in the uterus.

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Prenatal Transplantation of Human Amniotic Fluid Stem Cell Could Improve Clinical Outcome of Type III Spinal Muscular Atrophy

10.21203/rs.3.rs-117839/v1 ◽

2020 ◽

Author(s):

Steven W. Shaw ◽

Shao-Yu Peng ◽

Ching-Chung Liang ◽

Tzu-Yi Lin ◽

Po-Jen Cheng ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Amniotic Fluid ◽

Spinal Muscular Atrophy ◽

Motor Function ◽

Therapeutic Potential ◽

Muscular Atrophy ◽

Human Amniotic Fluid ◽

Type Iii ◽

Amniotic Fluid Stem Cell

Abstract BackgroundType III spinal muscular atrophy (SMA) is a single gene disorder affecting motor function in uterus. Several types of stem cells were utilized to ameliorate SMA based on its capability of regeneration and differentiation. Amniotic fluid is an alternative source of stem cells and is safely sampled without ethical issues. Human amniotic fluid stem cell (hAFSC) shared common surface markers of mesenchymal stem cell. Therefore, this study aims to examine the therapeutic potential of hAFSC for SMA. MethodsOur SMA model mice were generated by deletion of exon 7 of Smn gene and knock-in of human SMN2. A total of 16 SMA model mice were injected with 1x105 hAFSC in uterus, and the other 16 mice served as the negative control. Motor function was analyzed by Rotarod maintenance test, tilting test and grasping test every two months. Twelve months after transplantation, all organs were extracted for post-mortem analysis. Engraftment of hAFSC in organs were assessed by flow cytometry and RNA scope. To observe the function of neuromuscular junction, frequency of myocytes, neurons and innervated receptors were estimated by H&E, methylene blue and immunocytochemistry staining. ResultsWith hAFSC transplantation, 15 fetuses from 5 dams survived (15 of 16, 93.75% survival) and showed better performance in all three motor function tests. Higher engraftment frequency in organs were observed in muscle and liver after hAFSC transplantation. Besides, the muscle of SMA mice with hAFSC transplantation expressed much laminin α and PAX-7. Significantly higher frequency of myocytes, neurons and innervated receptors were observed after hAFSC transplantation. ConclusionsIn our study, hAFSC engrafted on neuromuscular organs and improved cellular and behavioral outcomes of SMA model mice. This fetal therapy could preserve the time window and treat in the uterus to avoid irreversible damage.

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