Validity of a patient-derived system of tissue-specific human endothelial cells: interleukin-6 as a surrogate marker in the coronary system

The aim of our study was to evaluate the relevance of tissue- and species-specific endothelial cells (EC) to study EC-dependent mechanisms in inflammatory-mediated tissue injury. We established an isolation protocol for highly purified EC (pEC) preparations of different origin and compared EC-specific inflammatory responses. Fluorescence-activated cell separation was used to obtain pEC cultures from different human arterial ( coronary artery, internal thoracic artery) and venous ( umbilical vein, saphenous vein) vessels. All pEC were analyzed for growth kinetics, morphology, release of cytokines/chemokines, and expression of E-selectin. For all different EC cultures, purities of >= 99% were reproducibly achieved. The EC isolation did not affect EC growth, morphology, and function. However, characterization of pEC from different vessel materials revealed an intrinsic, tissue- specific functional heterogeneity of EC cultures. Despite an arterial and venous difference in the secretion of IL-8 and monocyte chemoattractant protein-1, especially EC from coronary arteries produced significantly more IL-6 compared with other EC types, independent of age, gender, and disease of the cell donors. In contrast, the expression of E-selectin was not affected. We conclude that the proposed isolation protocol allows the generation of a pEC bank, enabling us to study tissue- specific aspects at the level of the endothelium.