Mitochondrial membrane potential changes (ΔMMP) were assessed using the JC-1 MitoScreen Kit (BD Biosciences Systems, San Jose, CA, USA) as described previously.25 (link) Sample of cells at 106 cells/mL was suspended in a buffer mixture and JC-1 dye provided by the kit manufacturer. Then the cells were incubated for 15 mins at 37 °C, washed, and re-suspended in buffer. Samples prepared in this way were subjected to cytometric analysis using a cytometer BD FACSCanto II and FACSDiva software (both from BD Biosciences Systems, San Jose, CA, USA).