Human Umbilical Cord Mesenchymal Stem Cells-Secreted TSG-6 Is Anti-Inflammatory and Promote Tissue Repair After Spinal Cord Injury

Spinal cord injury (SCI) causes patients paralysis and hard to recover. The therapeutic effects of current clinical drugs are accompanied by side effects. In recent years, stem cell therapy has attracted the attention of researchers. Human umbilical cord mesenchymal stem cells (hucMSCs) have been widely used in various diseases due to their excellent paracrine function. TNF-stimulated gene 6 (TSG-6), a secretion factor of stem cells, may play an important role in hucMSCs in the treatment of SCI. So we conducted an experiment to explore its effect. We first observed that the expression of TSG-6 increased in SCI rats after injected with hucMSCs. Then, we used siRNA to knowdown the expression of TSG-6. We treated SCI rats with TSG-6-knockdown hucMSCs. Without TSG-6 expression, hucMSCs treatment made the tissue recovery worse and the number of Nissl bodies less. Meanwhile, neutrophils infiltrated more in the damaged parts. Our research also proved that TSG-6 may help demyelination recovering and alleviate astrocytes gathering in the injury sites. Our study revealed that hucMSCs secreted TSG-6 may decrease the degeneration of myelin sheath, reduce inflammation, decrease neuron loss and promote tissue repair. These results provided a new therapeutic factor for the treatment of SCI.