Figure 3: MICU1 modulates ΔΨ_m responses and apoptosis in OvCa cells.

(a,b) In siCTL-/siMICU1-CP20 cells (a) and siCTL-/siMICU1-OV90 cells (b), loaded with the fluorescent mitochondrial membrane potential (ΔΨ_m) indicator TMRE, cisplatin caused significant membrane depolarization in MICU1 silenced cells compared to respective siCTL cells receiving similar treatment values are represented as mean±s.d. FCCP was used as a negative control. (c) siCTL/siMICU1-OV90 treated or untreated with cisplatin were immuno-probed for apoptotic markers (cleaved PARP, cleaved caspase-3 and cleaved caspase-9). GAPDH was used as a loading control. (d) Quantification of apoptotic cell number in CP20 and OV90 cells upon cisplatin treatment (10 μM). Silencing MICU1 sensitized cells to cisplatin-induced apoptosis and values are mean±s.d. (e) siCTL-/siMICU1-CP20 cells grown on coverslips were incubated with mtROS detecting agent MitoSOX (5 μM) and then imaged. (f) mtROS contributes to cisplatin sensitization in MICU1 silenced cells. Cisplatin (10 μM) treatment in CP20 cells in presence of mtROS scavenger MitoTempo (10 μM) failed significantly to induce apoptosis in siCTL- or siMICU1-CP20 cells and values are represented as mean±s.d. *P<0.05 when compared to siCTL (a,b) or vehicle (d,f). Two-sided Student’s t-test was used for statistical analysis with unequal variances. Statistical significance was set at P<0.05. All the experiments were repeated independently at least three times and in triplicate.