Fig. 1.

Effects of hypoxia and reoxygenation on thioredoxin proteins in MIN6 cells. Each panel shows a representative western blot, the respective densitometric quantification data on the left, and the respective ELISA data on the right. (A) Intracellular Trx1, (B) Trx2, (C) TrxR1, (D) TrxR2, (E) extracellular Trx1, and (F) Txnip were analyzed in MIN6 cells cultured at 1% or 2% O₂ for 12 h with (+) or without (−) reoxygenation (reox.) for another 12 h. Normoxic cells cultured at 20% O₂ for 12 or 24 h were used as controls. Extracellular concentrations of Trx1 were determined in the supernatant of the cultivated cells. Actin or tubulin were not detected in these samples excluding the presence of cell lysis as potential source of extracellular Trx1. Images and densitometric quantifications are representative of n = 3–5 independent experiments. All ELISA data are normalized to 20 μg of protein lysate per well and given in ng/ml (n = 5). ^ap<0.05 vs. 2% O₂ +; ^bp < 0.0001 vs. 20% O₂ 12 h; , ^cp < 0.0001 vs. 20% O₂ 24 h; ^dp < 0.01 vs. 2% O₂ +; ^ep < 0.001 vs. 20% O₂ 12 h; ^fp < 0.001 vs. 20% O₂ 24 h; ^gp < 0.01 vs. 20% O₂ 12 h; ^hp < 0.01 vs. 20% O₂ 24 h; ⁱp < 0.001 vs. 1% O₂ +; ^jp < 0.05 vs. 20% O₂ 12 h, ^kp < 0.05 vs. 20% O₂ 24 h; ^lp < 0.01 vs. 2% O₂ -; ^mp < 0.05 vs. 2% O₂ -; ⁿp < 0.0001 vs. 2% O₂ +; ^op < 0.0001 vs. 1% O₂ +; ^pp < 0.0001 vs. 2% O₂ –; ^qp < 0.001 vs. 2% O₂ +.