Effects of Sepsis Serum on the Fate of Adipose Tissue-Derived Stem Cells.

Background: Adipose tissue-derived stem cells (ADSCs), a type of mesenchymal stem cell, have been used extensively in clinical trials for the treatment of multiple conditions, including sepsis. However, increasing evidence indicates that ADSCs vanish from tissues within days of administration. Consequently, it would be desirable to establish the mechanisms underlying the fate of ADSCs following transplantation.

Methods: In this study, sepsis serum from mouse models was used to mimic microenvironmental effects. Healthy donor-derived human ADSCs were cultured in the presence of mouse serum from normal or lipopolysaccharide (LPS)-induced sepsis models for the purposes of discriminant analysis. The effects of sepsis serum on ADSC surface markers and cell differentiation were analyzed by flow cytometry, and the proliferation of ADSCs was assessed using a Cell Counting Kit-8 (CCK-8) assay. Quantitative real-time PCR (qRT-PCR) was applied to assess the degree of ADSC differentiation. The effects of sepsis serum on the cytokine release and migration of ADSCs were determined based on ELISA and Transwell assays, respectively, and ADSC senescence was assessed by β-galactosidase staining and western blotting. Furthermore, we performed metabolic profiling to determine the rates of extracellular acidification and oxidative phosphorylation and the production of adenosine triphosphate and reactive oxygen species.

Results: We found that sepsis serum enhanced the cytokine and growth factor secretion and migratory capacities of ADSCs. Moreover, the metabolic pattern of these cells was reprogrammed to a more activated oxidative phosphorylation stage, leading to an increase in osteoblastic differentiation capacity and reductions in adipogenesis and chondrogenesis.

Conclusions: Our findings in this study reveal that a septic microenvironment can regulate the fate of ADSCs.