Ecdysterone-sensitive smooth muscle cell proliferation stimulated by conditioned medium of endothelial cells cultured with bloody cerebrospinal fluid

Abstract

The concept that vascular cell proliferation plays an important role in the pathogenesis of cerebral vasospasm is based mainly on animal models and remains controversial. The objective of this study was to test the hypothesis that injured endothelial cells could stimulate the proliferation of vascular smooth muscle cells (VSMCs) and ecdysterone, a main active component of some traditional Chinese herbs, could play an inhibitory role in the process. Rabbit brain microvessel endothelial cells (BMVECs) were cultured with media containing bloody cerebrospinal fluid (BCSF), with or without ecdysterone at 5 × 10-5 mol/l. The resulting conditioned media (CM) were collected and the content of nitric oxide (NO) and endothelin (ET-1) were determined by Griess reaction and radioimmunoassay, respectively. The proliferative effect of the conditioned media on rabbit vascular smooth muscle cells was evaluated by 3H-thymidine incorporation and flow cytometry analysis. Conditioned medium from bloody cerebrospinal fluid treatment stimulated more proliferation of vascular smooth muscle cells than the untreated medium as well as the conditioned medium from bloody CSF and ecdysterone co-treatment. This increased proliferation correlated with a decreased concentration of NO and an elevated concentration of ET-1 in the conditioned media. In conclusion, we observed that the medium from brain microvessel endothelial cells cultured with bloody cerebrospinal fluid activated vascular smooth muscle cell proliferation in vitro and the proliferative effect could be reduced by ecdysterone. © 2008 Springer-Verlag.