Figure 8.

Deletion of the Mitochondrial Pyruvate Carrier Alleviates ER stress

(A and B) The NADPH/NADP+ ratio (A) and the GSSG/GSH ratio (B) were measured as mentioned earlier in parental wild-type and Mpc1^−/− C2C12 myoblasts.

(C) Expression of UPR markers BiP, CHOP, phosphorylated eIF2α, and MPC1 was analyzed by immunoblot in wild-type and Mpc1^−/− C2C12 myocytes treated with 100 ng/mL TM, 1 μg/mL TM, or 100 nM thapsigargin (TG). Loading control was actin. Hairlines are for visual aid only.

(D) Relative mRNA expression of UPR markers from cells treated similarly to (C) was quantified by qRT-PCR.

(E) Primary hepatocytes from Mpc2^fl/fl and Mpc2^LKO mice were treated with 250 ng/mL TM, and gene expression was measured by qRT-PCR.

(F) Splicing of Xbp1 in TM-treated hepatocytes from Mpc2^fl/fl or Mpc2^LKO mice was assessed by conventional RT-PCR. The ordering of the second and third groups was rearranged by cut/paste to remain consistent with the rest of the data in the article, but the image was otherwise unmodified.

(G) Xbp1 splicing was quantified from 8 independent samples (4 from cells taken from a male mouse, 4 from cells taken from a female mouse).

(H) Model for how TCA cycle activity is linked to ER homeostasis.