Adipose-derived stem cells secrete pro- and anti-inflammatory cytokines after major burn injury

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells derived from adipose tissue which is an abundant and easily obtainable resource. ADSCs have an important role in orchestrating the immune response to injury. Few studies have evaluated the role of paracrine factors from stem cells in burn wounds. The objective of this research was to examine the paracrine factors secreted from ADSCs in patients with major burn injury.

Adipose tissue was collected from patients with full-thickness burn injuries at their index operation and non-burn adipose tissue was obtained from elective breast surgery patients. ADSCs were extracted from the adipose tissue specimens. Fluorescence-activated single-cell sorting (FACS) confirmed the presence of ADSCs. ADSCs were grown under standard tissue culture techniques, and the supernatant was extracted for analysis. A ten-analyte cytokine multiplex analysis was performed. Histology staining of the adipose tissue was also performed to identify the presence of immune cells. Univariable analyses were performed using the Wilcoxon rank-sum test and multivariable analyses were conducted using Tobit regression, RESULTS: A total of 38 patients were included in the study with 17 burn patients and 21 non-burn patients. FACS demonstrated ADSCs with the expression of CD 90, CD 105, and CD 73 antibodies. Levels of IL-8 were all significantly higher in the burn cohort (p < 0.05). Histologic staining revealed a higher number of lymphocytes and macrophages in the burn fat compared to the non-burn fat.

This was the first study to demonstrate that ADSCs extracted from burn adipose tissue have a predominant pro-inflammatory response. Future studies are needed to investigate the potential role of paracrine factors from ADSCs to improve wound healing in major burns.