H subtype vascular endothelial cells in human femoral head: An experimental verification

Abstract

Background: Osteonecrosis of the femoral head (ONFH) is difficult to treat, and leads to an impaired microcirculation of the femoral head and activation of a repair response. The type H vessels have been proved to mediate the growth of the bone vasculature and couple angiogenesis to osteogenesis. The aim of the study is to investigate the experimental verification of H subtype vascular endothelial cells (HSVECs) in the human femoral head. Methods: Vascular endothelial cells were isolated from femoral heads of patients who underwent hip replacement. Cells were isolated by the methods of enzymic digestion and density gradient centrifugation, purified by differential adhesion and selective medium. The HSVECs were characterized for localization of endothelial cell markers such as von Willebrand factor (vWF), vascular cell adhesion molecule-1 (VCAM-1), CD31 and Endomucin (Emcn) by immunofluorescence staining. Cell morphology was observed by microscopy. Results: The HSVECs expressing vWF, VCAM-1, CD31 and Emcn were identified by immunofluorescence. After 3–4 days of culture, adherent cells were observed evenly distributed in the culture flasks, and inconsistent in size and shape. Following 7–8 days of culture, the cells formed a monolayer after fusion, arranged in fascicular, whorled, and the growth was attachment-inhibited. Most of the cells appeared short spindle, polygon and cobblestone-like morphologic characteristics. Conclusions: Here we make an effective experimental verification of HSVECs in the human femoral heads, which will facilitate the study of ONFH, hip osteoporosis and other bone diseases in vitro.