Immunohistochemical studies on vascular endothelial growth factor and platelet endothelial cell adhesion molecule-1/CD-31 in islet transplantation

H. Watanabe et al., Immunohistochemical studies on vascular endothelial growth factor and platelet endothelial cell adhesion molecule-1/CD-31 in islet transplantation, PANCREAS, 21(2), 2000, pp. 165-173
Citations number
Categorie Soggetti
da verificare
Journal title
ISSN journal
0885-3177 → ACNP
Year of publication
165 - 173
SICI code
Neovascularization may be necessary for better and longer function of trans planted islets. Vascular endothelial growth factor (VEGF) is known to be on e of the most important factors of angiogenesis. Recently, VEGF was reporte d to be expressed in islets of normal pancreas. We studied the expression o f VEGF and neovascularization related peptides in transplanted islets. To d etermine the angiogenic microcapillary, immunochemical staining was perform ed for Factor VIII-related antigen (von Willebrand factor [VWF]) and platel et endothelial cell adhesion molecule-1/CD31 (PECAM-1), both of which are k nown as markers of the angiogenic microvessel. Transplantable islets were i solated from Lewis rats (8-10 weeks of age) by discontinuous dextran gradie nt after collagenase digestion. Seven to twelve hundred islets were injecte d into the portal vein (IPV group, n = 7) or transplanted into subnephrocap sular cavity (SNC, n = 12) of the same descent rats. In the IPV group, the liver was resected 1 hour, 1 week, or 4 weeks after transplantation (Tx). I n the SNC group, the kidney was resected 1, 3, 7, or 28 days after Tx. Each tissue was fixed in formaldehyde and embedded in paraffin. Serial 4-mu m s lices were immunostained for insulin, VEGF, PECAM-1, or vWF using specific antibodies. In IPV group, insulin-positive cells were VEGF positive as were in the normal pancreas at all time points. Islets of 1 hour after Tx were barely PECAM-1 positive as were in normal pancreas, but islets became weakl y stained at 7 and 28 days after Tx. In vWF staining, transplanted islets s howed stronger staining than those in the normal pancreas. In SNC group, VE GF was also stained in insulin-positive cells at 1, 3, 7, and 28 days. In P ECAM-1 staining, islets of 1 day after Tx were barely stained as were in no rmal pancreas. However, the staining was increasingly enhanced from 3 to 7 days and then appeared weakened at 28 days after Tx. In VWF staining, islet s were always vWF positive, as was seen in IPV group. This study revealed t hat PECAM-1 appeared in islets after islet Tx, suggesting that neovasculari zation occurs within the islet grafts. On the other hand, VEGF of transplan ted islet did not obviously vary with time. Enhancement of the neovasculari zation may lead to better results of islet Tx.