A variety of mild stresses upregulate stanniocalcin-1 (STC-1) and induce mitohormesis in neural crest-derived cells

We induced upregulation of stanniocalcin-1 (STC-1) by various mild and long lasting stresses and assayed its influence on mitochondrial membrane potential (MMP) in the neural crest-derived cell line Paju. The obtained data showed that starvation (24–96 h), exposure to 10 nM TPA, and low concentrations (0.05–1 μM) of As2O3 significantly (3–5 times) upregulated Paju cell STC-1 RNA and stabilized the mitochondrial membrane potential (MMP). However, high concentrations of As2O3 (2.5–5.0 μM) increased intracellular ROS and free calcium levels and, consequently, suppressed STC-1 and MMP. The results show that cells preconditioned by various mild stresses expressed more STC-1 and their MMP were more resistant to a secondary exposure to As2O3 (2.5–5 μM, 96 h) demonstrating mitohormesis. We suggest that MMP deviation from control levels, to an extent innocuous to cell viability, is a general signal for STC-1-induction and MMP-protection. Our findings of Paju cell MMP-regulation may be of great importance for inventing new ways to prevent neurodegenerative diseases and unravel the mechanisms behind drug resistance.