Fig. 3. Ca²⁺ dependent activation of CAMKK2 promotes fatty acid oxidation.

a P-AMPK and P-ACC expression after inhibition of CAMKK2 kinase activity by STO-609 (10 μM) or stimulation of CAMKK2 by the Ca²⁺ ionophore A23187 (1 μM). b Basal OCR of MYC HME cells after pre-incubation in STO-609 (10 μM). The OCR was measured in the presence of 0.10 mM palmitate; n = 5 replicates from one independent experiment. Error bars represent mean ± s.e.m.; p values were calculated using an ordinary one-way ANOVA and Tukey’s multiple comparison test. c Relative mRNA expression of PDGFRB in HME cells normalised TERT and relative to β-actin; n = 3 independent experiments. Error bars represent mean with upper and lower limits; p values were calculated using an unpaired Student’s t-test. d Fold change in intracellular [Ca²⁺] in TERT and MYC HME cells upon PDGF-BB treatment. Traces represent individual cells for each cell line. e Basal OCR of MYC HME cells in the absence (unstimulated) and presence of 25 ng/ml PDGF-BB. All OCR measurements were done in the presence of 0.10 mM palmitate; n = 5 replicates. Error bars represent mean ± s.e.m. Total oxygen consumption was calculated based on the area under the curve for each sample. The average of total oxygen consumption was compared between groups using ANOVA with post-hoc multiple comparisons. Unadjusted p values are reported. f Basal OCR of MYC HME cells after treatment with STO-609 (10 μM) or etomoxir (40 μM). All OCR measurements were done in the presence of 0.10 mM palmitate; n = 5 replicates. Error bars represent mean ± s.e.m. Total oxygen consumption was calculated based on the area under the curve for each sample. The average of total oxygen consumption was compared between groups using ANOVA with post-hoc multiple comparisons. Unadjusted p values are reported; *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, N.S. = not significant.