Effects of Ribonuclease Inhibitor on the Rat Glial Cell Line C6 Injured by H_2O_2
Pan Dong · Zhongguo shengwu huaxue yu fenzi shengwu xuebao · 2002
Ribonuclease inhibitor (RI) is an acidic cytosolic glycoprotein which molecular mass was estimated to be 50 kD.RI inhibits the activities of ribonuclease A (RNase A) and angiogenin by forming a very tight complex with a stoichiometry of 1∶1.RI contains 30 cysteine residues.In this sense,RI is a good candidate to be controlled in vivo by thiol\|disulfide exchange reaction in response to change in cellular redox status.Effects of RI on the rat glial cell line C6 injured with H\-2O\-2 were studied by the comparison between the transfected C6 cells with RI cDNA in which RI was overexpressed and the control C6 cells.The transfected C6 cells had higher viability,less LDH leakage and MDA contents,but more GSH contents.This result showed that RI had antioxidant activity and it was able to protect cells from peroxidative injuries.The antioxidant mechanism of RI was not only due to its multithiol group in a molecule,but also the transfected C6 cells showing more catalase and glutathione S\|transferase activities.Catalase activities in transfected C6 cells increased by 0 73 time than in the control C6 cells,and glutathione S\|transferase activities increased by 2 72 times.It is possible that RI may be as an antioxidant in tissues to inhibit the formation of tumor.The work may be a useful base for gene therapy of RI and others.