Studies On The Molecular Mechanism Of Toxicity Of Clioquinol In Saccharomyces Cerevisiae Based On Proteomic Technology

Clioquinol(CQ)is a commonly used antibiotic.Recent studies have shown that CQ has a therapeutic effect on neurodegenerative diseases and tumors.However,its cellular mechanism remains unclear.This investigation aims to use proteomic technology to identify the target protein or target signal pathway of CQ and further study its molecular mechanism of action in model organisms Saccharomyces cerevisiae.In our study,the growth of Saccharomyces cerevisiae was inhibited by CQ.It did not kill cells,but shortened G1 phase and arrested cell cycle at G2/M phase.By using two-dimensional electrophoresis based proteomic approach,six proteins were found to be significantly affected by CQ.Among them,four(PDC1,ADH1,TDH3,IPP1)were up-regulated and the other two(TDH1 and PGK1)were down-regulated.According to the Saccharomyces Genome Database(SGD),these proteins were involved in various biological processes including glycolytic fermentation,gluconeogenesis,glycolytic process,amino acid catabolism,redox reaction and reactive oxygen species metabolic process.TDH1 and TDH3 are GAPDH isoenzymes.It is noted that there is a link between TDH3 and cell cycle.RT-PCR analysis showed that the mRNA levels of CLN3 and CDC28,critical genes for passage through G1 phase,were up-regulated after the treatment of CQ.It demonstrates that CQ arrests cell cycle at G2/M phasethrough up-regulating the expression of CLN3 and CDC28 induced by TDH3..For another,CQ increased the content of ROS and MDA in yeast cells and inhibited the oxidative damage caused by GSH,SOD and CAT activities,which may be one of the reasons leading to the promotion of autophagy.Of important note is that TDH3 also participates in the reactive oxygen species metabolic process.Therefore,TDH3 may be one of the target molecule of CQ to inhibit the growth of yeast.Also,our data showed that CQ could upregulate the expression of GAPDH in human neuroblastoma cells.The conservatism of its mechanism in human cells needs to be studied in the future.This study provides new research clues and ideas for the cellular mechanism of CQ.Also it provides basic data for this compound in neurodegenerative diseases and cancer treatment.