Fig. 6: Long-term glucagon treatment promoted mitochondrial dysfunction.
From: Prolonged glucagon exposure rewires lipid oxidation and drives diabetic kidney disease progression
a ATP/ADP ratio in HK2 cells treated with 100 nM glucagon for varying durations. b Fatty acid oxidation of NRK-52E cells: NRK-52E cells were pretreated with 100 nM glucagon for 24 h or 1 h before the assay, and then, palmitate substrate was added to the wells just before measuring the OCR. Where indicated, etomoxir (4 μM, inhibitor of CPT1), oligomycin (2.5 μM, inhibitor of ATP synthase), FCCP (2 μM, uncoupler of oxidative phosphorylation) and antimycin/rotenone (0.5 μM, inhibitors of respiratory complex) were added. c Basal respiration, maximal respiration, ATP production and respiration capacity were calculated from the OCR in NRK-52E cells. d Images of live mitochondria stained with PKMO in NRK-52E cells. Scale bar: 2 μm. e Mitochondrial superoxide (MitoSOX, red) staining of HK2 cells treated with 100 nM glucagon and 50 μM PA for the indicated period. Scale bar: 100 μm. f–h Representative western blot and quantification of fibronectin and phosphorylated and total S6 in HK2 cells treated with high glucose (30 mM) or 100 nM glucagon with or without the PKA inhibitor H89 (10 μM). i–k Representative western blot and quantification of fibronectin and phosphorylated and total S6 in HK2 cells treated with high glucose (30 mM) or 100 nM glucagon with or without the mTOR inhibitor rapamycin (30 nM). The error bars represent the SEMs; n  = 3-8 biologically independent cells (a‒k). OCR, oxygen consumption rate; FN1, fibronectin.
