Fig. 1Basal oxygen consumption rates in islets isolated from Atg7Δβ-cell and control mice (n=5 to 8 per group). Data are presented as fold changes±SE, and comparisons were performed using a Mann-Whitney U test. Atg7, autophagy-related 7. aP<0.05 compared to the control.
Fig. 2Intracellular adenosine 5'-triphosphate (ATP) content induced by glucose stimulation of islets isolated from Atg7Δβ-cell and control mice (n=3 to 10 per group). (A) ATP content under low-glucose (1.6 mM) and high-glucose (16 mM) conditions. All values were normalized relative to those of control islets under low glucose conditions. (B) Fold change in ATP content induced by high-glucose stimulation. Data are presented as fold changes±SE, and comparisons were performed using a Mann-Whitney U test. Atg7, autophagy-related 7; NS, not significant. aP<0.05 compared to control.
Fig. 3Mitochondrial respiration in islets isolated from Atg7Δβ-cell and control mice (n=9 to 10 per group). (A) Representative graphs of mitochondrial respiration using Oxygraph-2k. Red lines indicate oxygen consumption rate in response to sequential loading of mitochondrial effectors (indicated by arrows below the graphs). (B) Quantitative comparisons of oxygen consumption rate in response to effectors. Data are presented as means±SE, and comparisons were performed using repeated measures analysis of variance and Mann-Whitney U tests. G+M, glutamate and malate; ADP, adenosine diphosphate; FCCP, carbonyl-cyanide-4-(trifluoromethoxy)-phenylhydrazone; AA, antimycin A; Atg7, autophagy-related 7. aP<0.05 compared to control islets.
Fig. 4Expression of mitochondrial complex genes by quantitative real-time polymerase chain reaction (A) in Atg7Δβ-cell and control islets (n=7 to 8 per group), and (B) in β-TC6 cells transfected with siAtg7 or with siNS as a control (n=4). The expression levels were normalized to that of glyceraldehyde 3-phosphate dehydrogenase. Data are presented as means±SE, and comparisons were performed using Student t tests or Mann-Whitney U tests, depending on sample variances. P value is presented above the bar graph. Atg7, autophagy-related 7. aP<0.05 compared to control islets.
Table 1Sequences of Primers for Quantitative Real-Time Polymerase Chain Reaction