Canine bone marrow stromal cells promote functional recovery in mice with spinal cord injury

Can Paraplegia by Disruption of the Spinal Cord Tissue Be Reversed? The Signs of a New Perspective

Central nervous system (CNS) trauma is often related to tissue loss, leading to partial or complete disruption of spinal cord function due to neuronal death. Although generally irreversible, traditional therapeutic efforts, such as physical therapy exercises, are generally recommended, but with a poor or reduced improvement of the microenvironment, which in turn stimulates neuroplasticity and neuroregeneration. Mesenchymal stem cells (MSCs) have paracrine, immunomodulatory, and anti-inflammatory effects. Here we use stem cells to see if they can promote not only physical but also the functional regeneration of neuronal tissue in dogs with CNS traumas. Two dogs, one with chronic spinal cord injury and one with subacute spinal cord injury, underwent infusion of autologous MSCs in association with physiotherapy. The two treatments in combination were able to partially or completely recover the dog's walking movement again. The treatment of MSCs in association with physical therapy improved the microenvironment, which could be evidence of a paradigm shift that the CNS is not capable of functional regeneration after aggressive traumas. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1812-1820, 2020. © 2019 American Association for Anatomy.

Mesenchymal stem cells transplanted into spinal cord injury adopt immune cell-like characteristics

Background

Mesenchymal stem cells (MSCs) and their cellular response to various stimuli have been characterized in great detail in culture conditions. In contrast, the cellular response of MSCs in an in vivo setting is still uncharted territory. In this study, we investigated the cellular response of MSCs following transplantation into spinal cord injury (SCI).

Methods

Mouse bone marrow-derived MSCs were transplanted 24 h following severe contusion SCI in mice. As controls, MSCs transplanted to the uninjured spinal cord and non-transplanted MSCs were used. At 7 days post transplantation, the MSCs were isolated from the SCI, and their global transcriptional changes, survival, differentiation, proliferation, apoptosis, and phenotypes were investigated using RNA sequencing, immunohistochemistry, and flow cytometry.

Results

MSCs transplanted into SCI downregulated genes related to cell-cycle regulation/progression, DNA metabolic/biosynthetic process, and DNA repair and upregulated genes related to immune system response, cytokine production/response, response to stress/stimuli, signal transduction and signaling pathways, apoptosis, and phagocytosis/endocytosis. MSCs maintained their surface expression of Sca1 and CD29 but upregulated expression of CD45 following transplantation. Transplanted MSCs maintained their surface expression of MHC-I but upregulated surface expression of MHC-II. Transplanted MSCs survived and proliferated to a low extent, did not express Caspase-3, and did not differentiate into neurons or astrocytes.

Conclusion

MSCs transplanted into SCI upregulate expression of CD45 and MHC-II and expression of genes related to cytokine production, phagocytosis/endocytosis, and immune cells/response and thereby adopt immune cell-like characteristics within the recipient.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1218-9) contains supplementary material, which is available to authorized users.

Icariside II promotes the osteogenic differentiation of canine bone marrow mesenchymal stem cells via the PI3K/AKT/mTOR/S6K1 signaling pathways

The aim of the present study was to investigate the osteogenic effects of icariside II (ICSII) on canine bone marrow mesenchymal stem cells (BMSCs) and the pathways by which these effects were induced. BMSCs were cultured and expanded to the fourth passage. The proliferative effects of ICSII were assessed using the cell counting kit-8 (CCK-8) assay. The osteogenic response to ICSII in BMSCs in vitro was examined by alkaline phosphatase (ALP) activity assays and Alizarin red staining. Using Western blot assays and real-time PCR (RT-PCR), we examined the expression of osteogenetic proteins/genes. We also evaluated changes in Akt and S6K1 phosphorylation levels, along with changes in the expression of osteogenesis proteins/genes after pretreatment with wortmannin (an inhibitor of phosphatidylinositol 3-kinase; PI3K) or rapamycin [a specific inhibitor of mammalian target of rapamycin (mTOR)] in the presence or absence of ICSII. Our results show that ICSII promotes the proliferation of BMSCs, while inhibiting ALP activity. We also found that calcium nodules form after BMSCs are treated with ICSII and osteogenetic medium for 21 days. ICSII significantly increased the expression of osteogenesis proteins/genes and elevated the phosphorylation levels of Akt and S6K1. Treatment with wortmannin or rapamycin attenuated the expression of p-Akt, p-S6K1, and osteogenesis proteins/genes. These results suggest that ICSII promotes the osteogenic differentiation of canine BMSCs via the PI3K/AKT/mTOR/S6K1 signaling pathways.