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

Steven W. Shaw,Hao-Yu Chuang,Shao-Yu Peng,Po-Jen Cheng,Tzu-Yi Lin,Paolo De Coppi,Anna L. David,Ching-Chung Liang,T’sang-T’ang Hsieh

doi:10.1038/s41598-021-88559-z

Abstract

Spinal 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.

Highlights

Spinal muscular atrophy (SMA) affects about 8.5 to 10.3 of 100,000 n ewborns[1]
Amniotic fluid was sampled by amniocentesis from pregnant women during 15th to 20th gestational week
Stem cells expressing MSC markers were isolated from amniotic fluid and cultured in an amniotic medium

Summary

Introduction

Spinal muscular atrophy (SMA) affects about 8.5 to 10.3 of 100,000 n ewborns[1]. This is a life-threatening neurodegenerative disease with autosomal recessive inheritance. Type III SMA merely contributed to difficulty in climbing stairs and getting up from the floor, but the limitation of motion would progressively grow and require a wheelchair. Embryonic stem cells demonstrated their potential of forming neuromuscular junction and differentiation into neuron to repair a musculocutaneous nerve in SMA r at[7]. Induced pluripotent stem cells were proved to delay the atrophy of muscle and retain neuromuscular function in SMA murine m odel[8]. These stem cells had the common potential of neural differentiation for treating neuromuscular diseases. The objective of this study was to investigate the therapeutic effectiveness of hAFSC transplantation for SMA

Objectives

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Results

Conclusion