Figure 6. Genetic ablation of Mrs2 exhibits higher mitochondrial PDH activity and oxygen consumption rate.

(A) Permeabilized cells were exposed to FCCP at indicted time point to asses basal mMg²⁺. (B) Normalized basal _mMg²⁺. Mean ±SEM.

(C) Representative transmission electron micrographs (TEM) of WT (left) and Mrs2 KO (right) hepatocytes.

(D and E) TEM analysis of mitochondrial length and number in WT and Mrs2 KO hepatocytes. Four images per mice. n=3 mice per group. Mean ±SEM.

(F) Western blot depicting the abundance of mitochondrial OXPHOS complex proteins in WT and Mrs2 KO hepatocytes. n = 3 mice per group.

(G) Oxygen consumption rate (OCR) of untreated WT and Mrs2 KO hepatocytes.

(H) OCR curves of WT and Mrs2 KO hepatocytes treated with 0.5 mM lactate, after basal measurements, at the indicated time point. (Bottom panels) Bar chart depicts basal, maximal, and proton leak. Mean ±SEM; n=3.

(I) OCR curves depicting hepatocytes pretreated for 24 hours with either LPS (100 μg/ml) alone or in combination with GSK2837808A (100 nM) or Oxamate (20 mM). Bar charts depict basal and maximal respiration and proton leak from the above traces. Mean ±SEM. n= 6–8.

(J) WT and Mrs2 KO hepatocytes were treated with LPS (1, 10 and 100 μg/ml) for 6 hours and immunoblotted for p-PDH E1α (S293), PDH E1α, and β-actin. Densitometric analysis shown below. n=3. Mean ±SEM.

*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. n.s. = not significant.