Is the expression of Gal-alpha1,3Gal on porcine pancreatic islets modified by isolation procedure?

AIM: The aim of this study was to study the Galactosyl alpha(1,3) Gal expression and the vascular tissue distribution prior to and after isolation of porcine pancreatic islets. METHODS: Biopsies of native pancreas were carried out in young (12-15 weeks; n = 4) and adult Landrace pigs (2 years old; n = 7). These pancreases were then digested (Liberase Porcine Islets [PI]) to obtain isolated pancreatic islets from each pancreas. Alpha Gal-specific biotinylated BS-1 isolectin B4 and von Willebrand's Factor (vWF) staining were performed for Galactosyl and vascular structure analysis, respectively. Quantitative Galactosyl expression as well as location of the vascular structure were determined using image analysis in pig islets of different sizes. RESULTS: Vascular structures and Galactosyl expression varied following the islet sizes but not the pig age. In large islets (>100 microm), capillaries were mainly located within the islets, whereas in small islets (<100 microm), 4-fold more vessels were situated at the periphery of the islets. Galactosyl expression followed a comparable distribution than vascular tissue in small and large islets. After isolation, a significant decrease of Gal staining (-49%) was observed, but Galactosyl expression remained positive within both small and large islets. CONCLUSIONS: Galactosyl expression is maintained within pancreatic islets after isolation procedure. Gal knock-out pigs could represent the solution to this hurdle.