Thanks for the poster- very nice. Have you looked at the levels of GSH and GSSG, the total amount of each, and also the ratio of these under the different O2 partial pressures. Do these vary with the pO2 ?
Dear Prof. Michael Davies,
Thank you for your question. It is an interesting question.
I did not measure the amount of each (GSH and GSSH) separately. I only detected the reduced GSH level under different O2 level using the fluorescent probe (o-phthalaldehyde, OPA).
While previous studies mentioned that the ratio of GSH: GSSH is often used as a marker of cellular redox state. In a resting cell, the molar GSH: GSSG ratio exceeds 100:1, while in various models of oxidative stress, this ratio has been demonstrated to decrease to values of 10:1 and even 1:1 (Ref. Shelly C. Lu. Biochim Biophys Acta. 2013.; Ondrej Zitka. Oncology Letters. 2012.).
As we have shown that the antioxidant enzymes and Nrf2-targeted protein expression were at different levels under 18, 5 and 1kPa, indicating that HCASMCs were at a different redox state. Perhaps the ratio of GSH: GSSH varies with the pO2.
Meanwhile, the two steps of GSH synthesis requires coupled ATP hydrolysis. According to our results, ATP level was lower under 1kPa compared to 18 and 5kPa, which may contribute to the ratio of GSH: GSSH varies as well.
You must be logged in to post a comment.