Abstract 231: Bone Marrow-Derived Mesenchymal Stem Cells from Amputated Limbs of Patients with Critical Limb Ischemia Provide Stromal Support for Endothelial Cells

Abstract

Critical limb ischemia (CLI) often results in amputation, but autologous cellular therapy using bone marrow-derived mesenchymal stem cells (MSCs) may be able to prevent this outcome. However, the quality of MSCs in the CLI population is not clear. Amputated CLI limbs contain reservoirs of MSCs that can be used to characterize their stromal capacity. We hypothesize that MSC stromal capacity is relatively preserved in ischemic limbs compared to ones from healthy donors. Methods Healthy donor MSCs (hdMSCs, n=2) and ischemic MSCs (iMSCs, n=3) from amputated limbs of non-diabetic CLI patients were cultured. Human microdermal ECs were commercially obtained. Co-culture pellets (1:1 ratio) of hdMSC:EC, iMSC:EC, and EC alone were formed and cultured in 3-D fibrin hydrogels in EC growth media. Images of the pellets and invasion areas were captured up to 5 days. The invasion area was quantified as the difference between the total and pellet area normalized to initial pellet area. Experiments were performed in quadruplicates and co-culture experiments were duplicated. Results iMSC:EC co-culture provided similar stromal support as the healthy donor cohort. Both MSC groups were significantly greater than the ECs alone following day 2 (see figure, *P<0.0005, ANOVA). Both MSC groups also exhibited significant increase in invasion area with time (P<0.01) while the ECs did not (P>0.5). Conclusion This is the first study to demonstrate that iMSCs provide similar stromal support to ECs as healthy hdMSCs, thus iMSCs may be of sufficient quality for use in autologous therapy. We are currently quantifying secretome expressions of the iMSCs to provide insights into mechanisms of the stromal support.