A method for the isolation of glomerular and tubulointerstitial endothelial cells and a comparison of characteristics with the human umbilical vein endothelial cell model

Background: Abnormalities in the structure and function of glomerular endothelial cells play a pivotal role in the development of progressive renal disease. The vascular abnormalities observed in the renal tubulointerstitium, however, correlate more strongly with progressive renal failure. Therefore, the successful isolation and culture of human renal microvascular endothelial cells from both the glomerulus and tubulointerstitium are paramount in studying renal disease models. Methods and Results: This study describes a simple and reproducible method for the isolation of human tubulointerstitial and glomerular endothelial cells by using immunomagnetic separation with anti-platelet endothelial-cell adhesion (anti-PECAM-1) Dyna beads, followed by manual weeding of mesangial and fibroblast contamination. No significant changes in morphological or immunohistochemical characteristics were observed up to passage two of culture. The in vitro characteristics of the endothelial cells were compared to the renal cortical endothelial cells in vivo and the standard human umbilical vein endothelial cell model (HUVECs). Similar to HUVECs, both populations of renal microvascular endothelial cells had a classical cobblestone appearance, stained positively for von Willebrand Factor and PECAM-1 and negatively for antifibroblast surface antigen and anticytokeratin. Differences in the expression of von Willebrand Factor, Wiebel Palade bodies and Flk-1 staining were observed between glomerular and tubulointerstitial endothelial cells. These immunohistochemical characteristics suggested that tubulointerstital endothelial cells were more closely aligned to HUVECS than to the glomerular endothelial cells. This observation indicated that HUVECs may be a suitable model for determining the tubulointerstitial endothelial response to systemic injury. Conclusion: In conclusion, a unique and novel method for the differential isolation of both glomerular and tubulointerstitial endothelial cells has been developed. Significantly, characterization of these populations suggests a role for HUVECS in the study of renal tubulointerstitial disease.