Clarification of promoting effect on engraftment of intraportally transplanted islet cells under hepatic regeneration

目的：为了实现单一供体胰岛移植后成功的胰岛素依赖，我们在术后即刻观察了肝再生对胰岛细胞移植的影响。我们证明，肝再生促进了功能植入，改善了大鼠胰岛素分泌和移植后高血糖。本研究的目的是通过微阵列穷竭基因分析，阐明肝再生条件下胰岛细胞在门脉内移植的促进作用。方法：取单一供体胰岛，于肝部分切除(HxPIT)后立即移植给链脲佐菌素糖尿病大鼠(HxPIT)，同时移植给未行肝切除的大鼠(PIT)。移植后24小时取出受体大鼠的肝脏，从肝内移植的胰岛细胞中提取RNA。结果：HxPIT大鼠移植的胰岛体积较大，并被肥大的β细胞颗粒化。移植的胰岛和胰岛素染色的胰岛细胞的大小均大于PIT大鼠。基因芯片分析表明，HxPIT大鼠肝细胞生长因子(HGF)和血管内皮生长因子(VEGF)的表达高于PIT大鼠。未来，我们将利用显微切割技术从移植的胰岛中提取RNA，以最大限度地排除没有移植胰岛细胞的RNA。然后，我们将绿色大鼠(绿色荧光蛋白；GFP基因转移大鼠)作为胰岛移植的供体，在荧光显微镜下利用显微切割技术选择性地仅摘除胰岛细胞。

PURPOSE : To achieve successful insulin independence after single-donor islet transplantation, we had examined the impact of hepatic regeneration on engraftment of islet cells transplanted intraportally in the immediate postoperative period. We demonstrated that hepatic regeneration promotes functional engraftment and ameliorates insulin secretion and posttransplantation hyperglycemia in rat. The aim of this study was to clarify promoting effect on engraftment of intraportally transplanted islet cells under hepatic regeneration by exhaustive gene analysis using micro array.METHODS : Isolated pancreatic islets from a single-donor were intraportally transplanted to streptozotocin-diabetic rats immediately after 70% partial hepatectomy (HxPIT) and were also transplanted to the rats without hapatectomy (PIT). The livers were removed from the recipient rats after 24 hours posttransplantation, and then RNA was extracted from intrahepatic engrafted islet cells. We analyzed gene expression of the RNA using rat micro array (Rat Genome 230 2.0 Array).RESULTS : Morphologically, grafted islets from HxPIT rats were large and granulated by hypertrophic beta cells. The sizes of the grafted islets and indivisual insulin-stained islet cells were larger than those from PIT rats. The gene analysis using micro array demonstrated that the expression of hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) of the RNA extracted from HxPIT rats was statistically higher than that from PIT rats.FUTURE EVOLUTION : For the future, we will extract RNA from grafted islets using microdissection technique to exclude most surely the RNA without grafted islet cells. And then, we will use green rats (green fluorescent protein ; GFP gene transfer rats) for the donor in islet transplantation to extirpation selectively only islet cells using microdissection technique under the fluorescent microscope.