Bingxiang Wang

Since the molecule of Ca2+-activated Cl- channels (CaCC) had been identified as ANO1, major progresses have been made in recent studies on its roles in vascular functions. ANO1 has been confirmed to represent the CaCC channels in vascular smooth myocytes (VSMCs). Generally, ANO1 expresses more in resistance-size small arteries. When activated, it functions to control the VSMC membrane potentials by depolarization. As a result, the voltage-dependent Ca2+ channel is opened, leading to Ca2+ entry and VSMC contraction. Thus, the function of ANO1 is important for maintenance of normal blood pressure. Under influence of agonists, e.g., angiotensin II, ANO1 also participates in VSMC differentiation and remodeling which are mediated by KLF5, myocardin and SRF. The factors regulate the transcription of the ANO1 gene and other genes for VSMC differentiation and proliferation.

7, 8-dihydroxyflavone (7, 8-DHF), a selective agonist for TrkB receptors, has been well studied for its neurotrophic functions. However, its roles outside the neural tissues have scarcely been studied as yet. In this study, we investigated the protecting roles of 7, 8-DHF in EA.hy926 cells, a human umbilic vein endothelial cell line which was exposed to hydrogen peroxide (H₂O₂). We found that 7, 8-DHF significantly protected the cells from being damaged by H₂O₂ through suppression of apoptosis, attenuation of inflammatory factor releasing and inhibition of reactive oxygen species generation. The potent biological effects of 7, 8-DHF were probably executed via its binding to TrkB receptors because the receptor specific antagonist ANA-12 significantly blocked its protecting effects. The protecting roles of 7, 8-DHF in EA.hy926 cells suggest that it will be a promising compound to be developed into a health product that definitely benefits endothelial functions and prevents cardiovascular diseases.