The process of wound healing requires the transportation of substrates needed for the rebuilding of tissue through vessel formation from pre-existing vessels, i.e., angiogenesis. Adipose tissue extract is often used to facilitate the wound healing process, which is attributed to its potent angiogenic properties. Most angiogenic processes are regulated through growth factors such as vascular endothelial growth factor, angiopoietin, fibroblast growth factor, and leptin. Leptin is predominantly synthesized and secreted by adipocytes; therefore, it was hypothesized that mature adipocytes augment angiogenic processes in dispersed adipose tissue, which is attributed to leptin. Subcutaneous adipose tissue was collected from 4 prepubertal female pigs (gilts) at 148 +/- 12 days of age weighing 80 +/- 6 kg and enzymatically dispersed (collagenase type II). Cells were separated into 2 groups 1) mature lipid-filled adipocytes (MA) and 2) all other cell types (AOC; vascular endothelial cells (VEC), preadipocytes, fibroblasts). The AOC was incubated for 24 hr in cell culture media with 10% fetal bovine serum (FBS) to promote attachment, which conditions the environment to promote the morphological changes required for vessel tube formation. After the AOC attachment period, media was removed and replaced with MA in culture media with or without leptin (10-11 M) or rabbit polyclonal leptin antibody (1:100 dilution) and incubated for an additional 24 hrs. The MIXED procedure of SAS was utilized to determine the effect of treatment on angiogenic cellular processes in-vitro. The addition of MA stimulates (P<0.05) the progression in each stage of angiogenesis; however, leptin antibody mitigated the effect of MA on vessel tube formation. Although exogenous leptin did not augment morphological progression of vessel tube formation, leptin antibody suppressed VEC elongation and vessel tube formation (P<0.05). Mature adipocytes stimulate VEC angiogenic progression, which is attributed, in part, to endogenous adipocyte leptin production.
Faculty mentor: Dr. Michelle Garcia
Department of Animal Science and Veterinary Technology
