Stromal vascular fraction promotes fibroblast migration and cellular viability in a hyperglycemic microenvironment through up-regulation of wound healing cytokines

Diabetic wounds have impaired healing and a propensity for further morbidity, which may result in amputations. Stromal vascular fraction (SW) is an autologous source of heterogeneous cell population obtained from adipose tissue, which is rich in stem cells and presents little immunogenicity to the host. In this study, we hypothesized that murine fibroblasts subjected to hyperglycemic conditions co-treated with SW exhibit greater functional activity through the colorimetric MTT assay and a cell-monolayer in-vitro scratch assay. We sought to establish the underlying mechanism of action via the utility of an ELISA chemiluminescence array on the supernatant medium of the cells. Our results demonstrate that the mean percentage gap closure at 24 h in the hyperglycemia + SW group was significantly greater at 41.1% 1.6% compared to the hyperglycemia alone group 16.6% +/- 1.5% (post-hoc Bonferroni test p < 0.001, n = 3) although there was no difference between the SW and normoglycemia group. Further, this SW group exhibited a significantly greater 2.4 fold increase in fibroblastic cell viability as compared to the hyperglycemia alone group (p = 0.001, n = 3). The supernatant medium of the cells upon testing with ELISA indicated that early phase wound healing cytokines including platelet-derived growth factor (p = 0.012, n = 3), interleukin-1 (p = 0.003, n = 3), basic fibroblast growth factor (p = 0.003, n = 3) and interleukin-10 (p = 0.009, n = 3) were expressed in significantly greater relative luminescent units in SW as compared to hyperglycemia alone groups (Student t-test). Taken together and for the first time, our study shows that SW is a promising therapeutic agent for up-regulating fibroblastic activity in a hyperglycemic microenvironment, and this result can be explained in part by the stimulation of wound-healing cytokines.