Oxygen consumption rate (OCR)
Oxygen consumption rate (OCR) was measured using the XFe96 analyzer (Agilent Technologies). Briefly, cells (4 X 104 cells) were plated into wells of an XFe96 cell culture microplate and incubated at 37 ⁰C in a CO2 incubator for 24 hours. The assay was started after cells were equilibrated for 1 hour in XF assay medium supplemented with 10 mM glucose, 1 mM sodium pyruvate and 2 mM glutamine. OCR activity was monitored through sequential injections of 1 µM oligomycin, 0.6 μM FCCP, and 1 μM rotenone/ antimycin A to calculate basal, coupled, maximal respiration and spare respiratory capacity. Each plotted value was normalized either to cell counts. Agilent Seahorse XF Analyzer measures oxygen consumption rate (OCR) at intervals of approximately 5-8 min. OCR data were evaluated using 8 individual well values.