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TheScientificWorldJOURNAL
Volume 6 (2006), Pages 176-186
http://dx.doi.org/10.1100/tsw.2006.37
Mini-Review Article

Endothelin-2/Vasoactive Intestinal Contractor: Regulation of Expression via Reactive Oxygen Species Induced by CoCl22, and Biological Activities Including Neurite Outgrowth in PC12 Cells

1Institute for Biological Resources and Functions National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Ibaraki 305-8566, Japan
2New Energy and Industrial Technology Development Organization (NEDO), 16F, MUZA KAWASAKI Central Tower, 1310 Omiya-cho, Saiwai-ku, Kawasaki, Kanagawa 212-8554, Japan

Received 21 October 2005; Revised 16 January 2006; Accepted 18 January 2006

Academic Editor: Martin Goette

Copyright © 2006 Eiichi Kotake-Nara and Kaname Saida.

Abstract

This paper reviews the local hormone endothelin-2 (ET-2), or vasoactive intestinal contractor (VIC), a member of the vasoconstrictor ET peptide family, where ET-2 is the human orthologous peptide of the murine VIC. While ET-2/VIC gene expression has been observed in some normal tissues, ET-2 recently has been reported to act as a tumor marker and as a hypoxia-induced autocrine survival factor in tumor cells. A recently published study reported that the hypoxic mimetic agent CoCl2 at 200 µM increased expression of the ET-2/VIC gene, decreased expression of the ET-1 gene, and induced intracellular reactive oxygen species (ROS) increase and neurite outgrowth in neuronal model PC12 cells. The ROS was generated by addition of CoCl2 to the culture medium, and the CoCl2-induced effects were completely inhibited by the antioxidant N-acetyl cysteine. Furthermore, interleukin-6 (IL-6) gene expression was up-regulated upon the differentiation induced by CoCl2. These results suggest that expression of ET-2/VIC and ET-1 mediated by CoCl2-induced ROS may be associated with neuronal differentiation through the regulation of IL-6 expression. CoCl2 acts as a pro-oxidant, as do Fe(II, III) and Cu(II). However, some biological activities have been reported for CoCl2 that have not been observed for other metal salts such as FeCl3, CuSO4, and NiCl2. The characteristic actions of CoCl2 may be associated with the differentiation of PC12 cells. Further elucidation of the mechanism of neurite outgrowth and regulation of ET-2/VIC expression by CoCl2 may lead to the development of treatments for neuronal disorders.