Figure 6.

IP6K1 enhances cellular fat accumulation by diminishing AMPK mediated energy metabolism. A. IP6K1-KO MEFs accumulate less fat following oleate (OA, 24 h) treatment. B. β (OA)-oxidation is increased in IP6K1-KO MEFs following OA (24 h) treatment. However, β (PA)-oxidation is increased under basal and PA (24 h) treated conditions (n = 3; t-test). C. AICAR treated IP6K1-KO MEFs display enhanced β-oxidation (n = 3; two-way Anova). D. Complementation of IP6K1-KO MEFs with active but not inactive Myc-IP6K1 restores OA-induced fat storage. E. Catalytically active but not inactive Myc-IP6K1 complementation reduces AICAR induced β-oxidation in IP6K1-KO MEFs (n = 3; one-way Anova). F. PGC1α mRNA expression is higher in IP6K1-KO MEFs, which is further enhanced by AICAR treatment (n = 3; two-way Anova). G. PGC1α protein level is higher in OA-treated IP6K1-KO MEFs. AMPK activity on PGC1α is also enhanced whereas PGC1α acetylation is reduced. H. AMPK stimulatory phosphorylation (T172) and its activity on ACC (S79) are enhanced in OA-treated IP6K1-KO MEFs. I. TNP enhances AMPK phosphorylation and activity in glucose starved 3T3L1 preadipocytes. Glucose induction reduces AMPK phosphorylation and activity in control but not in TNP treated cells. J and K. TNP enhances OCR in starved and glucose induced 3T3L1 preadipocytes (8 replicates; t-test). L. TNP enhances AMPK phosphorylation in 3T3L1 adipocytes, under basal conditions. AICAR was used as a positive control. M. TNP, at increasing concentrations, reduces fatty acid biosynthesis in 3T3L1 adipocytes. The ACC inhibitor TOFA was used as a positive control (n = 3; one-way Anova). N. CD-KOs, at 23 °C, display higher AMPK phosphorylation and activity in the RWAT depot. O. CD-KOs, at 23 °C, are sensitive to AICAR induced reduction in blood glucose level (5–6 mice/group; two-way Anova). In all panels, data are expressed as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.