Extended Data Fig. 4: Analysis of succinate levels in isolated brown adipocytes and effect of muscle shivering on BAT succinate accumulation.
From: Accumulation of succinate controls activation of adipose tissue thermogenesis
a, Abundance of succinate in mouse plasma comparing 29 °C to acute 4 °C exposure (n = 6). b, Comparison of succinate abundance in BAT in vivo (n = 8) versus brown adipocytes (n = 7). c–f, Full 13C-isotopologue profile of fumarate (c), malate (d), citrate (e), and aspartate (f) in brown adipocytes following extracellular addition of [13C]succinate (n = 5). g, 13C-isotopologue (m + 4) profile of TCA metabolites downstream of mitochondrial succinate oxidation in BAT following intravenous administration of 100 mg kg−1 [13C]succinate as a bolus (n = 3). h, Time course of abundance of (m + 4) [13C]succinate in plasma following 100 mg kg−1 intravenous [13C]succinate (n = 3, except 15 min, n = 4). i, Representative mouse nuchal muscle EMG traces at 29 °C and after acute cold exposure with or without curare (0.1 mg kg−1). j, Quantification of succinate in BAT at 29 °C and after acute cold exposure with or without inhibition of muscle shivering with curare (0.1 mg kg−1; n = 5). k, Effect of acute addition of cellular and mitochondrial respiratory substrates on brown adipocyte respiration. Pyruvate: vehicle, n = 7; 1 mM, n = 6; 10 mM, n = 7; glucose: vehicle, n = 7; 1 mM, n = 6; 10 mM, n = 7; glutamine: vehicle, n = 6; 1 mM, n = 6; 10 mM, n = 7; G3P: vehicle, n = 7; 1 mM, n = 6; 10 mM, n = 6; αKG: vehicle, n = 6; 1 mM, n = 6; 10 mM, n = 5; fumarate: vehicle, n = 6; 1 mM, n = 6; 10 mM, n = 5; malate: vehicle, n = 6; 1 mM, n = 6; 10 mM, n = 7. l, Effect of acute addition of palmitic acid on brown adipocyte respiration (vehicle, n = 18; palmitic acid, n = 16). Effects on respiration were determined by acute addition of oligomycin (oli) to determine leak respiration, 2,4-dinitrophenol (DNP) to determine chemically uncoupled maximal respiration, and rotenone plus antimycin (r/a) to determine non-mitochondrial respiration. In all cases basal respiration in these cells is measured in the presence of 1 mM pyruvate. One-way ANOVA (a, j); data are mean ± s.e.m. of biologically independent samples.
