title: Expression of the endothelial markers PECAM-1, vWf, and CD34 in vivo and in vitro.
abstract: EC culture models are essential to study pathological alterations of endothelial cells (ECs) in pulmonary vascular diseases under standardized conditions. Nevertheless, little is known about the spectrum of alterations of vessel-specific endothelial phenotypes in monolayer cultures. For the comparative study of endothelial markers in vivo and in vitro we investigated immunohistochemically the expression of PECAM-1, vWf, and CD34 by pulmonary ECs in vivo and in stimulated/unstimulated human umbilical vein endothelial cells (HU-VEC) and human pulmonary microvascular endothelial cells (HPMEC). In vivo, vessel type-specific expression patterns were found for vWf and CD34, while PECAM-1 was homogeneously and strongly expressed. While all HUVEC showed a marked vWf staining, about two-thirds of HPMEC exhibited a strong and the rest a moderate vWf staining. In both in vitro models all ECs were clearly PECAM-1-positive. However, only about 20% of the HUVEC and HPMEC were CD34-positive. Our results demonstrate the reduced expression of vessel type-specific endothelial phenotypes by endothelial monolayer cultures, stressing the need to improve culture conditions as well as develop cocultures and three-dimensional culture models. Moreover, the need for endothelial markers specific for single microvascular type ECs becomes obvious in order to establish cultures consisting of only one microvascular ECs subpopulation.
authors: Institute of Pathology, University-Clinic Bergmannsheil, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, Bochum, 44789 Germany. annette.mueller@ruhr-uni-bochum.de
authors: Annette M
authors: AM
authors: Müller
authors: M Iris
authors: MI
authors: Hermanns
authors: Carmen
authors: C
authors: Skrzynski
authors: Maya
authors: M
authors: Nesslinger
authors: Klaus-Michael
authors: KM
authors: Müller
authors: C James
authors: CJ
authors: Kirkpatrick
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism*; D015415:Biomarkers; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000033:anatomy & histology / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008168:Lung / Q000098:blood supply / Q000276:immunology / Q000378:metabolism; D008833:Microcirculation / Q000033:anatomy & histology / Q000276:immunology / Q000378:metabolism; D010641:Phenotype; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism*; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D014841:von Willebrand Factor