Under normal conditions, ROS play crucial roles in diverse cellular functions, including cell signaling and immune responses
Model and physiological RS 2 and RSSR substrates are, for example, bis(2-hydroxyethyl)disulfide (HEDS) 1,3,12,14,30 , l-cystine 1,3 , redox-sensitive yellow or green fluorescent protein 2 (rxYFP or roGFP2) 14,15,31,32,33,34,35 , insulin 36,37 , collapsin response mediator protein 2 38,39 , the transcription factor OxyR 40 , 3-phosphoadenosine 5-phosphosulfate reductase (PR) 41,42 , methionine sulfoxide reductase (MSR) 34,43,44 , and ribonucleotide reductase (RNR) 2,34,45,46,47
In contrast, the expression of caspase-9 was shown to be reduced in ballooned hepatocytes in NASH specimens, which was explained by increased hedgehog signaling to prevent ballooned hepatocytes from death [87]
The barrier will still be an investigational new drug application in an FDA designated disease indication (of which for many of these peptide use cases, there isn't one)