Live-cell imaging Unveils stimulus-specific dynamics of Nrf2 activation in UV-exposed melanoma cells: Implications for antioxidant compound screening

• Published in: Free radical biology & medicine 2024-02, Vol.211, p.1-11
• Main Authors: Htut, Nilar Win, Onkoksoong, Tasanee, Saelim, Malinee, Kueanjinda, Patipark, Sampattavanich, Somponnat, Panich, Uraiwan
• Format: Article
• Language: English
• Subjects: Antioxidant Response Elements - genetics; Antioxidants - pharmacology; Humans; Living cell-based biosensor; Melanoma - genetics; NF-E2-Related Factor 2 - genetics; NF-E2-Related Factor 2 - metabolism; Nuclear factor erythroid 2-related factor 2 (Nrf2); Oxidative Stress; phytochemicals; Ultraviolet (UV) radiation
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2023.12.007

The transcription factor Nuclear factor e2-related factor 2 (Nrf2) is pivotal in orchestrating cellular antioxidant defense mechanisms, particularly in skin cells exposed to ultraviolet (UV) radiation and electrophilic phytochemicals. To comprehensively investigate Nrf2's role in maintaining cellular redox equilibrium following UV-induced stress, we engineered a novel Nrf2 fusion-based reporter system for real-time, live-cell quantification of Nrf2 activity in human melanoma cells. Utilizing live quantitative imaging, we dissected the kinetic profiles of Nrf2 activation in response to an array of stimuli, including UVA and UVB radiation, as well as a broad spectrum of phytochemicals including ferulic acid, gallic acid, hispidulin, p-coumaric acid, quercetin, resveratrol, tannic acid, and vanillic acid as well as well-known Nrf2 inducers, tert-butylhydroquinone (tBHQ) and sulforaphane (SFN). Intriguingly, we observed distinct dynamical patterns of Nrf2 activity contingent on the specific stimuli applied. Sustained activation of Nrf2 was empirically correlated with the increased antioxidant response element (ARE) activity. Our findings demonstrate the nuanced impact of different phenolic compounds on Nrf2 activity and the utility of our Nrf2-CTΔ16-YFP reporter in characterizing the dynamics of Nrf2 translocation in response to diverse stimuli. In summary, our innovative reporter system not only revealed compounds capable of modulating UVA-induced Nrf2 activity but also showcased its utility as a robust tool for future antioxidant compound screening efforts. [Display omitted] •Nrf2-CTΔ16-YFP reporter can monitor the ability of various phytochemicals to modulate UVA-induced changes in Nrf2 activity.•Nrf2 biosensor can reveal the complex dynamics of Nrf2 activity in response to various stimuli.•Our Nrf2 biosensor can be used as a robust tool for antioxidant compound screening.