FIGURE 5.

Fumarate mediates HIF-1α mRNA expression through non-canonical NF-κB signaling. A, phospho-TBK Ser¹⁷² (p-TBK S¹⁷²) and total TBK expression was examined in DKO (IKKα and IKKβ) MEFs treated with increasing concentrations of DEF in serum-free media for 6 h. B, phospho-TBK Ser¹⁷² and total TBK expression was assessed in RCC4 cells treated with increasing concentrations of DEF (upper panel) and DMF (lower panel) for 8 h in serum-free media. C, RCC4 cells were transiently transfected with siFH or scrambled control and total protein was analyzed for phospho-TBK Ser¹⁷², and total TBK. Actin was used as loading control. D, total TBK and phospho-TBK Ser¹⁷² expression was assessed in wild-type (WT), FH-deficient (FH^−/−), or FH-deficient with FH stably added back (FH^−/− + FH) MEFs.