Fig. 4.

P2Y1 and P2X4 receptors activate mitochondria in response to TCR/CD28 stimulation. a Jurkat cells expressing the mitochondrial Ca²⁺ indicator mito-CAR-GECO1 were pretreated for 10 min with specific antagonists of P2X4 (5-BDBD, 10 μM) or P2Y1 (MRS2279, 10 μM) receptors or with the general P2 receptor antagonist suramin (100 μM). Then, cells were stimulated by TCR/CD28 cross-linking, and changes in mitochondrial Ca²⁺ uptake were recorded over time using fluorescence microscopy. Traces of individual cells are shown in gray, and the averages of all cells acquired (n = 30–80) are shown in red. Data shown are representative of independent experiments (n ≥ 3). b Averaged mean fluorescence values (+ SEM) of cells (n = 30-80) from different experiments (n ≥ 3 experiments). c Peak mitochondrial Ca²⁺ levels following TCR/CD28 stimulation; mean ± SEM; *p < 0.05 vs. control, one-way ANOVA