Spinal cord injury is one of the most complicated and serious pathological impairments affecting the central nervous system. Since the human body is unable to regenerate and repair the spinal cord after injury, there is a high likelihood of suffering permanent damage and disability.
Often compounding the issue of SCI, secondary events occurring after the initial injury to the spinal cord significantly reduce cell migration and axonal regrowth and limit repair and regeneration.
Recently, transplantation of mesenchymal stem cells (MSCs) has been shown to promote the repair of injured spinal cord tissues in animal models. However, as Qu and Zhang highlight in this review, there remain many unanswered questions that are essential for improving the effects of this MSC therapy. As such, the authors focus this review on recent information about the behavior and function of MSCs in SCI, the function of biomaterials to direct the behavior of MSCs, and the attempt to emphasize combinational strategies such as tissue engineering for functional improvements of SCI.
There are studies showing that the migratory and homing capacities of MSCs are closely related to their engraftment and regeneration ability. Considering this, the authors highlight the importance of having MSCs migrate and integrate into host spinal cord tissue. Since MSC homing toward injured tissue is not an efficient process, and to ensure a more effective stem cell therapy outcome, it is important that these transplanted cells be introduced in a way that increases the migratory potential of healthy MSCs to the site of injured tissue.
Additionally, while transplanted cells have been identified adjacent to neurons after SCI, the surviving number of grafted and differentiated neurons was too small to be considered to contribute to functional recovery after SCI. However, data suggests that the ability of MSCs to secrete soluble factors or vesicles rather than engrafting and transdifferentiating might serve an important role in SCI repair.
The authors also point to studies that indicate MSC implantation could promote a therapeutic effect and functional recovery in experimental SCI animal models. The authors believe that this is a result of MSCs ability to differentiate into specialized neuronal and glial cell lineages after transplantation. While MSC transplantation has not yet been proven to be an effective and reliable therapy for SCI, additional studies need to be done before the therapy is utilized in clinical applications.
MSCs respond to the local environment in multiple ways and represent the most promising exosomes for neuropathic applications. Qu and Zhang conclude this review by calling for more intensive studies examining the potential benefits of combining MSCs with nerve tissue-engineered scaffolds to direct cell behaviors after SCI, including growth, migration, and differentiation.
Source: “Roles of Mesenchymal Stem Cells in Spinal Cord Injury – Hindawi.” https://www.hindawi.com/journals/sci/2017/5251313/.
St. Petersburg, Florida
