Figure 4. PGC1α alters mitochondrial fuel preference in podocytes.

(A) Oxygen consumption rate (OCR) of podocytes measured by Seahorse XF. Podocytes were cultured in various energy substrates (Seahorse XF Base Medium supplemented with glucose, palmitate, or glutamine). OCRs were measured at baseline, following 1 μM oligomycin, 3 μM FCCP, and 1 μM antimycin/rotenone (n = 5 per group). (B) ATP concentration in control and 2-deoxyglucose–treated podocytes (n = 10). Box-and-whisker plots show the median (line within box), upper and lower quartiles (bounds of box), and minimum and maximum values (whiskers). (C) Expression of genes involved in glycolysis in control and PGC1α-expressing podocytes. Glucose transporter 1 (Slc2a1), Slc2a4, hexokinase 1 (Hk1), Hk2, pyruvate kinase isozymes M1/M2 (Pkm), lactate dehydrogenase A (Ldha), and pyruvate dehydrogenase kinase 4 (Pdk4) were evaluated. (D and E) OCR in glucose/UK5099–treated podocytes (n = 20 per group). (F) Expression of genes involved in fatty acid oxidation in control and PGC1α-expressing podocytes. Acyl-CoA oxidase 1 (Acox1), Acox2, Acox3, lipoprotein lipase (Lpl), acyl-CoA dehydrogenase long chain (Acadl), acyl-CoA dehydrogenase very long chain (Acadvl), carnitine palmitoyltransferase I (Cpt1), and Cpt2 were evaluated. (G and H) OCR in palmitate/etomoxir–treated podocytes (n = 20 per group). (I) Expression of amino acid transporter in control and PGC1α-expressing podocytes. Neutral amino acid transporter B (Slc1a5), glutaminase (Gls), glutamate dehydrogenase 1 (Glud1), glutamic-oxaloacetic transaminase 1 (Got1), and Got2 were evaluated. (J and K) OCR in glutamine/BPTES–treated podocytes (n = 20 per group). *P ≤ 0.05, **P ≤ 0.01 by unpaired t test with Bonferroni correction or 1-way ANOVA with post-hoc analysis. ns, not significant; Ade, adenovirus; BPTES, bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide; FCCP, p-trifluoromethoxy carbonyl cyanide phenyl hydrazone; PGC1α, peroxisome proliferator-activated receptor γ coactivator-1α.