Characterization of Mitochondrial Bioenergetics of Adipose‐Derived Stem Cells from Burned and Non‐burned Patients

Abstract

Prolonged hypermetabolism is a hallmark of severe burn injury (over 20% of the total body surface area) that produces cachexia and hinders the wound healing process. Topical treatment with adipose‐derived stem cells (ASCs) have been proposed as an attractive solution to hasten the recovery of burn wounds. A potentially viable source of ASC is from the subcutaneous adipose tissue of severely burned patients, which would normally be discarded during surgical debridement. While previous studies found that severe burn injury alters the metabolic profile of subcutaneous adipocytes, the effect of severe burns on ASCs from burned victims is largely unknown. The purpose of this study is to compare the metabolic activity of ASCs from burned patients to those from non‐burned abdominoplasty patients by analyzing mitochondrial respiration and glycolysis. ASCs were isolated from adipose tissues from severely burned patients (BP, n=6) and abdominoplasty patients (AP, n=6). Cells were cultured to 80% confluence and harvested at at passage 2, 4, and 6 for analysis. Flow cytometry was used to determine ASC cell surface markers CD90, CD105, and CD73 and negative for CD34, CD11, CD19 and CD45. Mitochondrial abundance and reactive oxygen species (ROS) production were determined with MitoTracker Green and MitoSOX Red, respectively. JC‐10 Mitochondrial Membrane Potential Assays were used to determine mitochondrial membrane integrity. Mitochondrial respiration and glycolysis were analyzed in technical quadruplicates by a Seahorse XFe24 Analyzer. No significant differences were found in ASC surface markers, mitochondrial abundance or membrane potential among passages or between groups. A two‐way ANOVA showed that there was a significant effect (p<0.01) of passage number on mitochondrial ROS production. Mitochondrial respiratory states Basal, Leak (uncoupled), and Non‐mitochondrial respiration was significantly higher (p<0.05) at passage 6 than passage 2 for BP, but not AP. Additionally, Basal respiration was significantly higher at passage 6 in BP than AP (63.5±3.49 vs 45.7±4.26 pmol O2/min, p<0.001). Glycolysis significantly decreased (p<0.05) from passage 4 to 6 in AP but not BP ASCs. In summary, BP ASCs showed increased mitochondrial respiration with increasing passages and basal respiration was higher than AP ASCs patients at passage 6. While all ASCs retained their stem cell properties, they also showed increased ROS production through multiple passages which may cause oxidative stress that could limit the expansion of these cells ex vivo. The elevated mitochondrial activity from ASCs of burned patients may suggest these cells are more metabolically primed than those from abdominoplasty patients, but whether this thwarts their therapeutic potential requires additional investigation. Adipose‐derived stem cells from burned injured patients remain a potential viable source for burn wound therapies. While other studies have demonstrated efficacy in healing burn wounds, this study uncovers potential limitations in expansion of these cells ex vivo to use as coverage options for burned victims.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.