Host: The Japanese Society of Toxicology
Name : The 47th Annual Meeting of the Japanese Society of Toxicology
Date : 2020 -
Recently, it has been clarified that polysulfides have an antioxidant activity and are involved in intracellular protein functions by techniques such as analysis utilizing mass spectrometry and development of fluorescent probes. Additionally, when sulfide was added to serum in vitro system, it bound to serum proteins and was not observed as a sulfide, suggesting that the serum proteins have a sulfur metabolism mechanism. However, the presence of polysulfides in serum and other biological fluids has almost not reported because of lacks a method for quantifying oxidized polysulfides. Therefore, to develop a comprehensive understanding of oxidized polysulfide in serum, we developed a novel assay for measuring oxidized polysulfide and clarified its physiological functions. This assay revealed that polysulfides were present in biological fluids such as serum and semen, and that human serum albumin (HSA) maintained high concentrations of oxidized polysulfides in human blood. Interestingly, HSA could convert oxidized polysulfide to reduced polysulfide by the stimulation of oxidative stress, and has a reaction mechanism that temporarily increases antioxidant activity. This oxidative stress response was also observed in clinical serum samples from diabetic nephropathy and acute renal impairment, which are oxidative stress-related diseases. These findings will lead to the elucidation of the function control of serum proteins with sulfur metabolism mechanisms and the development of markers for prevention and diagnosis of oxidative stress diseases. In this symposium, we would like to introduce about the latest findings on biological fluids other than the polysulfide pool in blood described above.
