Comparative Study on the Differentiation of Mesenchymal Stem Cells between Fetal and Postnatal Rat Spinal Cord Niche

Abstract

In a previous study, we established a prenatal surgical approach and transplanted mesenchymal stem cells (MSCs) into the fetal rat spinal column to treat neural tube defects (NTDs). We found that the transplanted MSCs survived and differentiated into neural lineage cells. Various cytokines and extracellular signaling systems in the spinal cord niche play an important role in cell differentiation. In this study, we observed the differentiation of transplanted MSCs in different spinal cord niches and further observed the expression of neurotrophic factors and growth factors in the spinal cord at different developmental stages to explore the mechanism of MSC differentiation in different spinal cord niches. The results showed that transplanted MSCs expressed markers of neural precursor cells (nestin), neurogliocytes (GFAP), and neurons (β-tubulin). The percentages of GFP(+)/nestin(+) double-positive cells in transplanted MSCs in E16, P1, and P21 rats were 18.31%, 12.18%, and 5.06%, respectively. The percentages of GFP(+)/GFAP(+) double-positive cells in E16, P1, and P21 rats were 32.01%, 15.35%, and 12.56%, respectively. The percentages of GFP(+)/β-tubulin(+) double-positive cells in E16, P1, and P21 were 11.76%, 7.62%, and 4.88%, respectively. The differentiation rates of MSCs in embryonic spinal cords were significantly higher than in postnatal spinal cords (p < 0.05). We found that the transplanted MSCs expressed synapsin-1 at different developmental stages. After MSC transplantation, we observed that neurotrophic factor-3 (NT-3), fibroblast growth factor-2 (FGF-2), FGF-8, transforming growth factor-α (TGF-α), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF) significantly increased in the MSC transplantation group compared with the blank injection group. Furthermore, FGF-2 and VEGF expression were positively correlated with the number of surviving MSCs. In addition, we found that the expression of brain-derived neurotrophic factor (BDNF), NT-3, FGF-8, TGF-β, epidermal growth factor (EGF), and insulin-like growth factor (IGF) decreased with age, and the expression of FGF-2, FGF-10, FGF-20, TGF-α, and PDGF increased with age. Our data suggest that the embryonic spinal cord niche is more conducive to MSC differentiation after transplantation.

Transamniotic mesenchymal stem cell therapy for neural tube defects preserves neural function through lesion-specific engraftment and regeneration

“…The high potential of differentiation of BMSCs into neurons and skin cells observed in our NTD model may be due to early embryos were in a rapid development stage and lacked robust immune systems, resulting in a beneficial microenvironment for the engraftment and transdifferentiation of transplanted cells 57 . Our previous study showed that the prenatal rat spinal cord microenvironment was more conducive to neural differentiation of transplanted BMSCs than the postnatal rat spinal column one 21 . In addition, the therapeutic efficacy of MSCs depends not only on their direct local differentiation but also on other mechanisms, such as their paracrine capacity.…”

Hydrogel and neural progenitor cell delivery supports organotypic fetal spinal cord development in an ex vivo model of prenatal spina bifida repair

“…Due to their potential to engraft and to support endogenous neural cells within the host through immunomodulatory and trophic factors, the utility of mesenchymal stem cells has been more thoroughly investigated and has been beneficial in some MMC models of repair. 39,[48][49][50][51][52] The second major finding from our study is the successful establishment of an organotypic model specific to the affected lumbar spinal cord in fetal MMC. Specifically, slice cultures from MMC pups demonstrated robust survival of endogenous cells within fibrin hydrogels for up to 14 days and showed evidence of continued differentiation into mature neuronal phenotypes with robust neurite outgrowth along its periphery.…”

“…Due to their potential to engraft and to support endogenous neural cells within the host through immunomodulatory and trophic factors, the utility of mesenchymal stem cells has been more thoroughly investigated and has been beneficial in some MMC models of repair. 39 , 48 – 52 …”

Intra-Amniotic Delivery of CRMP4 siRNA Improves Mesenchymal Stem Cell Therapy in a Rat Spina Bifida Model

“…In addition, neurotrophic factors reportedly have a significant effect on anti-apoptosis in neural tissue. 45 In our previous studies, the intrauterine intra-spinal BMSC transplantation promoted the secretion of neurotrophic factors, thus improving the spinal cord microenvironment, 31 which is essential for the survival and differentiation of transplanted BMSCs and nerve tissue cells. In the present study, several growth factors in the spinal cord of spina bifida fetuses were induced after CRMP4 siRNA, BMSC, or CRMP4 siRNA + BMSC injection.…”

“…29,30 Reportedly, protecting the BMSCs from the poor microenvironment at defective sites by incubation with cytokines, or natural or chemical compounds, and the application of supporting materials could improve their function. 30,31 Therefore, we hypothesized that several harmful factors may be present in the spinal cord tissue of NTD fetuses, which could not only cause neuronal injury in the spinal cord, but also lead to a low BMSC survival rate and thus reduce their effects. In our previous study, a proteomic approach was used to screen and identify the differentially expressed proteins in a rat model of spina bifida and found that collapsin response mediator protein 4 (CRMP4) was significantly upregulated in the early NTD embryos and might contribute to the pathogenesis of spina bifida by regulating neuronal apoptosis and neurite growth.…”