Tibor Vag MD, Presenter: Nothing to Disclose

Werner Alois Kaiser MD, PhD, Abstract Co-Author: Researcher, Siemens AG Researcher, Bayer AG (Berlex Inc) Researcher, General Electric Company (Amersham plc) Researcher, Suros Surgical Systems, Inc Researcher, C. R. Bard, Inc Researcher, Boston Scientific Corporation Researcher, Galil Researcher, Invivo Researcher, Confirma Researcher, CAD Sciences Researcher, Carl-Zeiss

Ingrid Hilger, Abstract Co-Author: Nothing to Disclose

The design of highly specific contrast agents for molecular imaging of angiogenesis requires the availability of adequate in vitro models. In this context, we propose a cell model consisting of senescent and proliferating endothelial cells mimicking physiological and angiogenic vasculature. We investigated its applicability using optical imaging of selected angiogenic markers.

Human umbilical vein endothelial cells were cultured using different conditions to establish a proliferating and a senescent cell line. Proliferation rate and morphology was assessed by proliferation assay and light-microscopy. The presence of the pan-endothelial marker von-Willebrand-Factor (vWF) and selected angiogenic markers CD105, VEGFR2, TEM7 on the cell surface was evaluated using flow cytometry and gene expression using reverse-transcription-PCR. Visualisation of surface ligands was performed after specific labelling with fluorophores using a near infrared fluorescence (NIRF) small animal imager.

Proliferation assay confirmed two-fold increased cell proliferation and no proliferation respectively in the two culture subsets. Light-microscopy revealed tubular alignment of the senescent cells, which was absent in proliferating cells. Flow cytometry demonstrated the presence of vWF on both culture subsets and an up-regulation of CD105 but not of VEGFR2 and TEM7 on proliferating endothelial cells. While CD105 and VEGFR2 gene expression was detectable both in proliferating and in senescent cells, TEM7 was not expressed in any of the subsets. NIRF-imaging revealed highest fluorescence signal for CD105 in proliferating endothelial cells. No relevant fluorescence signal could be observed in VEGFR2 and TEM7.

The proposed in vitro cell model mimicking physiological and angiogenic endothelial cells has been confirmed on a morphological, protein and genetic level.

The model might be useful in future angiogenesis applications, like evaluating new fluorophores and other contrast media.

Vag, T, Kaiser, W, Hilger, I, Optical Imaging of Angiogenesis Markers in an in Vitro Model Mimicking Physiological and Angiogenic Endothelial Cells.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5012974.html