PP 132. Endothelial Progenitor Cells Enhance Muscle Revascularization before Islet Graft

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L. Quintane, T. Hubert, V. Gmyr, N. Delalleau, J. Kerr-Conte, N. Arrouche, G. Uzan, F. Pattou

17:36 - 17:42h at Lanchid Room

Categories: Endocrine Surgery, Poster Session

Session: Poster II (P4) - Varia

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Background
Optimization of islet vascularization is of paramount importance in the field of islet transplantation. Endothelial progenitor cells (PECs) have been shown to be able to differentiate into vessels. These cells improve the vascularization of cardiac muscle after heart attack in rats, and to improve clinical symptoms of chronic limb ischemia in humans. The aim of our study was to determine if transplantation of PECs with islets would improve islet vascularization, and improve their survival.

Material and Methods
In our minipig model of intramuscular islet autotransplantation, we explored the outcome of autologous islet transplantation with or without PECs. We used 7 females minipigs (n=7). Three hundred milliliters of blood was obtained from each animal. PECs were isolated from blood and cultured. We next performed a caudal pancreatectomy and islet isolation on each animal, and islets
were autotransplanted into the gracilius muscle using 4 different conditions: islets only, islet + PECs, islet + PECs (double dose), and PECs only. Two months later, grafts were explanted and animals were sacrificed. We used immunofluorescent staining for chromogranin A (red) to identify islets and immunofluorescence staining for von Willebrand Factor (vWF) (green) to assess the
neovascularization of the graft. We measured the ratio between the green stained surface and thegraft surface for each condition.

Result
The vascular density of the graft zone with PECs was significantly higher than the one without PECs (1.97 vs 7.37; p<0.0015).

Conclusion
These results suggest, in a clinically relevant preclinical model, that PECs can help to improve vascularization of the graft area.