LMP1 decreases mitochondrial respiration.

A) Schematic of mitochondrial stress test. Oxygen consumption rate (OCR) comparing B) LMP1+ vs LMP1- cells and C) LMP1+ untreated cells vs LMP+ cells treated with olaparib. D) Individual parameters for basal respiration (left), maximal respiration (middle) and ATP synthase-linked ATP synthesis (right). DG75 cells were pre-treated with 2.5 μM olaparib for 48 hrs and were then seeded to 300,000 cells/well and incubated for 1 h in XF base medium. Oxygen consumption rate was measured in XF base medium supplemented with glutamine (2 mM), glucose (10 mM), sodium pyruvate (1 mM) under basal conditions followed by the sequential addition of oligomycin (2 μM), FCCP (1 μM), and rotenone & antimycin A (2 μM), as indicated. Each data point represents an OCR measurement. Data are expressed as means ± SD, n = 6 technical replicates. The graphs are representative of four biological replicates. P values for significant differences (Student’s t-test) are summarized by three asterisks (p<0.001) and groups are compared to LMP1+ untreated samples.