H 2 O 2 signaling leads to the release of Nrf2 from complexes with Kelch-like ECH-associated protein 1 (Keap1) and ubiquitin ligase Cullin 3 and into the nucleus, where it binds to antioxidant response elements (ARE) and activates the expression of its target gene GPX8, which in turn regulates the expression of ER calcium by regulating SERCA ( 2 O 2 signaling and inhibiting Nrf2 translocation to the nucleus, resulting in a decrease in GPX8, resulting in increased ER calcium content and signaling ( via GPX8, in the same study, after silencing Nrf2 in HeLa cells, GPX8 mRNA and protein levels also decreased, resulting in elevated ER and cytosolic calcium levels at rest and increased histamine-induced ER calcium release (Tokuda et al., 2019)
Aged fibroblasts in culture, for example display a threefold reduction in population doubling time [34], with older cells reported to have an increased G0/G1 phase proportion due to repression of cell cycle progression genes [35]
Triple, quadruple and quintuple agonists are now in development, as is an expanded range of oral formulations
Doran AC, Yurdagul A, Tabas I
Preclinical studies using T4 (including the RGN-259 ophthalmic clinical trials) have not identified significant adverse events at therapeutic doses