BACKGROUND:The production and release of a large amount of inflammatory factors caused by immune system inflammatory response mainly contributes to secondary spinal cord injury. OBJECTIVE:To investigate the effects of umbilical cord Wharton’s jely mesenchymal stem cel transplantation on repair of injured neurological function and expression of inflammatory factors monocyte chemoattractant protein 1 and interleukin 10 in rats with acute spinal cord injury. METHODS: Eighty-one healthy adult male Sprague-Dawley rats were randomly and equaly divided into sham operation, model and cel transplantation groups, with 27 rats per group. Rats in the latter two groups were subjected to hemisection of the spinal cord to establish acute spinal cord injury models. Rat models in the cel transplantation group received umbilical cord Wharton’s jely mesenchymal stem cel injection (1×106)via the tail vein. Rat neurological function was evaluated using the BBB score at different time points after spinal cord injury. The expression of monocyte chemoattractant protein 1 and interleukin 10 in injured spinal cord tissue was detected using ELISA assay at different time points after spinal cord injury. Migration and neuronal differentiation of umbilical cord Wharton’s jely mesenchymal stem cels in the injured spinal cord tissue were determined using immunohistochemical staining method. RESULTS AND CONCLUSION:Compared with the sham operation and model groups, rat neurological function was significantly recovered in the cel transplantation group (P < 0.05). Compared to the model group, monocyte chemoattractant protein 1 level in the serum and monocyte chemoattractant protein 1 mRNA and protein expression in the injured spinal cord tissue were significantly lower (P < 0.05), but interleukin 10 mRNA and protein expression in the injured spinal cord tissue was significantly higher (P < 0.05), in the cel transplantation group. In the cel transplantation group, umbilical cord Wharton’s jely mesenchymal stem cels could migrate to the injured region and express glial fibrilary acidic protein. These findings suggest that umbilical cord Wharton’s jely mesenchymal stem cels promote rat neurological function recovery by regulating the inflammatory response in the injured spinal cord tissue, which is likely to be one of mechanisms by which transplantation of umbilical cord Wharton’s jely mesenchymal stem cels treats spinal cord injury.