NG2 immunoreactivity on human brain endothelial cells

In this study, we evaluated the expression of NG2 on human brain endothelia l cells derived from temporal lobe tissue resected as a treatment for intra ctable epilepsy. Using dissociated cell cultures, we found expression of NG 2 on both proliferating and non-proliferating cells, at the mRNA level by r everse transcription-polymerase chain reaction analyses, and at the protein level by immunocytochemistry and immunoblotting. We further observed that human cerebral microvessels in nonmalignant CNS tissues immunoreacted with NG2. NG2 protein was detected using both a rabbit antibody raised against t he rodent NG2 and a monoclonal antibody raised against the human NG2 (9.2.2 7). Our findings further define the range of resident cells of the CNS that can express NG2 and indicate that expression of NG2 by endothelial cells i s not restricted to proliferating CNS endothelial cells or to endothelial c ells found in brain tumors.