Fig. 7: Pioglitazone, a CISD1 inhibitor, inhibits IP3R activity and restores the defective ER calcium release caused by Parkin deficiency.
From: PINK1 and Parkin regulate IP3R-mediated ER calcium release
a HEK293T cells were transfected as indicated and treated with pioglitazone. Anti-Myc immunoprecipitates were analyzed for the association of IP3R1 using immunoblot analyses. The binding of IP3R and CISD1 was inhibited by a dose-dependent treatment of pioglitazone (100, 200, and 500 µM) for 30 min. Three independent experiments were done to quantitate the interaction between CISD1 and IP3R1 (bar graphs in right). b Measurement of the IP3R activity in HEK293 cells treated with 200 µM pioglitazone. The magnitude of the change during IP3 treatment was shown in bar graphs (right). n = 75–81 cells. c, d Analyses of ER and cytosol calcium modulations in Parkin KO cells when treated with pioglitazone. Measurement of ER (c) and cytosol (d) calcium modulations in WT (black) and Parkin KO (red) cells when treated with indicated concentrations of pioglitazone (blue, green, and purple). The right side bar graphs indicate the quantification of the normalized calcium traces using AUC of calcium release during ATP treatment. n = 85–127 cells. e, f Measurement of ER (e) and cytosol (f) calcium modulations in control (mef2>+, black) and Parkin null mutant flies (park1, red) when treated without or with 1 mM pioglitazone (blue and green). The right side bar graphs indicate the quantification of the normalized calcium traces using AUC of calcium release during ATP treatment. n = 12 flies (e). n = 10 flies (f). Two-tailed unpaired Student’s t test was used (b), and one-way ANOVA with Tukey’s multiple comparisons test was used (a and c–f). ****p < 0.0001. ***p < 0.001. **p < 0.01. *p < 0.05. ns represents not significant. Source data, the exact p values, and n number of each experiment are included within the Source Data file. All data are presented as mean ± SD.
