Xiao Xiangwei, Prasadan Krishna, Guo Ping, El-Gohary Yousef, Fischbach Shane, Wiersch John, Gaffar Iljana, Shiota Chiyo, Gittes George K
Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Ave, Pittsburgh, PA, 15224, USA,
Diabetologia. 2014 May;57(5):991-1000. doi: 10.1007/s00125-014-3179-y. Epub 2014 Feb 18.
AIMS/HYPOTHESIS: Vascular endothelial growth factor (VEGF) is essential for proper pancreatic development, islet vascularisation and insulin secretion. In the adult pancreas, VEGF is thought to be predominantly secreted by beta cells. Although human duct cells have previously been shown to secrete VEGF at angiogenic levels in culture, an analysis of the kinetics of VEGF synthesis and secretion, as well as elucidation of an in vivo role for this ductal VEGF in affecting islet function and physiology, has been lacking.
We analysed purified duct cells independently prepared by flow cytometry, surgical isolation or laser-capture microdissection. We infected duct cells in vivo with Vegf (also known as Vegfa) short hairpin RNA (shRNA) in an intrapancreatic ductal infusion system and examined the effect of VEGF knockdown in duct cells in vitro and in vivo.
Pancreatic duct cells express high levels of Vegf mRNA. Compared with beta cells, duct cells had a much higher ratio of secreted to intracellular VEGF. As a bioassay, formation of tubular structures by human umbilical vein endothelial cells was essentially undetectable when cultured alone and was substantially increased when co-cultured with pancreatic duct cells but significantly reduced when co-cultured with duct cells pretreated with Vegf shRNA. Compared with islets transplanted alone, improved vascularisation and function was detected in the islets co-transplanted with duct cells but not in islets co-transplanted with duct cells pretreated with Vegf shRNA.
CONCLUSIONS/INTERPRETATION: Human islet preparations for transplantation typically contain some contaminating duct cells and our findings suggest that the presence of duct cells in the islet preparation may improve transplantation outcomes.
目的/假设：血管内皮生长因子（VEGF）对于胰腺的正常发育、胰岛血管化及胰岛素分泌至关重要。在成年胰腺中，VEGF被认为主要由β细胞分泌。尽管此前已表明人导管细胞在培养中能以促血管生成水平分泌VEGF，但缺乏对VEGF合成与分泌动力学的分析，以及对这种导管VEGF在影响胰岛功能和生理方面的体内作用的阐释。
我们分析了通过流式细胞术、手术分离或激光捕获显微切割独立制备的纯化导管细胞。我们在胰腺内导管输注系统中用Vegf（也称为Vegfa）短发夹RNA（shRNA）对体内的导管细胞进行感染，并在体外和体内检测导管细胞中VEGF敲低的效果。
胰腺导管细胞表达高水平的Vegf mRNA。与β细胞相比，导管细胞分泌型与细胞内VEGF的比例要高得多。作为一种生物测定，人脐静脉内皮细胞单独培养时基本检测不到管状结构的形成，与胰腺导管细胞共培养时显著增加，但与用Vegf shRNA预处理的导管细胞共培养时显著减少。与单独移植的胰岛相比，与导管细胞共移植的胰岛中检测到血管化和功能改善，但与用Vegf shRNA预处理的导管细胞共移植的胰岛中未检测到。
结论/解读：用于移植的人胰岛制剂通常含有一些污染的导管细胞，我们的研究结果表明胰岛制剂中导管细胞的存在可能改善移植结果。
