Abstract
Dr. Hideo Kimura is recognized as a redox pioneer because he has published an article in the field of antioxidant and redox biology that has been cited >1000 times, and 29 articles that have been cited >100 times. Since the first description of hydrogen sulfide (H(2)S) as a toxic gas 300 years ago, most studies have been devoted to its toxicity. In 1996, Dr. Kimura demonstrated a physiological role of H(2)S as a mediator of cognitive function and cystathionine β-synthase as an H(2)S-producing enzyme. In the following year, he showed H(2)S as a vascular smooth muscle relaxant in synergy with nitric oxide and its production by cystathionine γ-lyase in vasculature. Subsequently he reported the cytoprotective effect of H(2)S on neurons against oxidative stress. Since then, studies on H(2)S have unveiled numerous physiological roles such as the regulation of inflammation, cell growth, oxygen sensing, and senescence. He also discovered polysulfides (H(2)S(n)), which have a higher number of sulfur atoms than H(2)S and are one of the active forms of H(2)S, as potent signaling molecules produced by 3-mercaptopyruvate sulfurtransferase. H(2)S(n) regulate ion channels and transcription factors to upregulate antioxidant genes, tumor suppressors, and protein kinases to, in turn, regulate blood pressure. These findings led to the re-evaluation of other persulfurated molecules such as cysteine persulfide and glutathione persulfide. Dr. Kimura is a pioneer of studies on H(2)S and H(2)S(n) as signaling molecules. It is fortunate to come across a secret of nature and pick it up. -Prof. Hideo Kimura.