Fig. 4.

GSH is constantly shuttled from AC to EC.

To investigate if EC take up AC-derived GSH, a stable isotope labelling approach was combined with Time-of-Flight Mass Spectrometry (TOF-MS) to specifically track AC synthesized GSH.(A) The schematic shows the experimental setup. Endogenous GSH was depleted by incubating with L-Cys/Met free media for 24h. ³⁴S¹⁵N-cysteine was employed to stimulate AC endogenous ³⁴S¹⁵N-GSH generation. Isotope-labeled AC were co-cultured with EC under different conditions for 24h then cell lysates were analyzed by TOF-MS. (B) Levels of intracellular ³⁴S¹⁵N-GSH was measured in untreated AC lysate (baseline) and after 24h isotope stimulation.(C) After co-culture, levels of labeled GSH in EC lysates were measured. *P<0.05, **P<0.01, ***P<0.001; Student’s T- test compared to baseline. Mean ± SD. n=4.