Secretome profile of TNF-α-induced human umbilical cord mesenchymal stem cells unveils biological processes relevant to skin wound healing.

An interference or delay in normal stages of the wound healing process, particularly in the elderly population and individuals with comorbid conditions, generally results in the development of chronic wounds with uncontrolled inflammation. Innovative therapies, such as stem cells and their secreted factors (the 'secretome') are potential tools in regulating wound repair. We used an inflammatory factor to precondition human umbilical cord stem cells to generate a secretome (induced secretome) that was beneficial in response to the inflammation environment. Approximately 260 proteins were detected. Further analysis identified that unique proteins in the induced secretome are mainly related to inflammation-related biological processes. We also demonstrated that the induced secretome enhanced the wound closure rate in human keratinocyte cells, as compared with the control and naive secretome. This is likely due to the higher levels of growth factors and cytokines in the induced secretome, which play significant roles in the regulation of the wound healing process. The present findings provide useful information to better understand the role of the human umbilical cord mesenchymal stem cell secretome, especially in an inflammatory niche, as well as the proteins that are important for clinical translation in wound repair.