Abstract

Glutathione (GSH) is a small antioxidant in the body and exists in large quantities compared to other antioxidants. The GSH redox state (Eh) helps developmental processes, however, when the GSH Eh is disrupted, cells may undergo significantly poor developmental pathways, possibly leading to long-lasting damages. Similarly, NADPH and Thioredoxin redox states can have a major impact on cellular function, viability, and response to both endogenous and exogenous toxicants. Subcellular, compartmentalized redox environments during normal or perturbed situations, specifically in the cytosol, mitochondria, and nucleus, are not well understood. Here, using the P19 neurogenesis model of cellular differentiation, the kinetics of subcellular H2O2 availability and GSH/GSSG and NADPH/NADP+ redox shifts were evaluated following oxidant exposure. Additionally, modified mouse embryonic fibroblasts (MEFs) were used to observe redox changes and protective mechanisms when major antioxidative pathways are inhibited, mainly those involving the GSH/GSSG and Trxred/Trxox pathways. Overall, treated undifferentiated cells showed a greater degree and duration of both H2O2 availability and GSH/GSSG and NADPH/NADP+ disruption throughout all compartments than differentiated neurons. Pretreatment with an Nrf2 inducer prevented H2O2-induced effects in all compartments of undifferentiated cells. Additionally, MEF cells without either GSH or Trx showed a greater degree and duration of GSH/GSSG and Trxred/Trxox disruption throughout the cytosol and nucleus when compared to normal functioning cells. Disruption of redox-sensitive developmental pathways is likely stage-specific, where cells that are less differentiated and/or are actively differentiating are most affected. Undifferentiated cells are more susceptible to oxidant-induced redox dysregulation but are protected through prior Nrf2 induction, which appears to preserve developmental programs and diminish the potential for poor developmental outcomes. The GSH and Trx antioxidant pathways converge to protect the cell, while cells that are missing one pathway or the other may undergo damaging developmental outcomes.

Degree

PhD

College and Department

Life Sciences

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2023-04-07

Document Type

Dissertation

Handle

http://hdl.lib.byu.edu/1877/etd13137

Keywords

roGFP, GSH, iNap, NADPH, TrxRFP1, Trx, Nrf2, D3T, H2O2, Hg, differentiation, P19, MEF

Language

english

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