Figure 4. Loss of Mrs2 enhances mitochondrial bioenergetics in hepatocytes from mice fed a Western diet.

(A and B) Quantification of hepatocyte lipid droplet size and comparison of occupancy by mitochondria (red) and lipid droplet (black) areas in 1 year diet fed mice. n = 3–4 mice.

(C) Representative confocal images of hepatocytes were acquired after staining with lipid/fatty acid marker BODIPY-488 and ${\text{ΔΨ}}_{\text{m}}$ indicator TMRE. n = 3 isolations.

(D) Spatial overlap and intensity profiles of mitochondrial colocalization of BODIPY and TMRE signals. n = 3 isolations.

(E) Western analysis of mitochondrial carnitine palmitoyltransferase 1A and MCU complex, MCU and MICU1 protein abundance in liver tissues harvested fromWT and Mrs2^−/− mice. n = 4 mice.

(F–H) Assessment of MCU-mediated _mCa²⁺ uptake (F), retention capacity (G), ${\text{ΔΨ}}_{\text{m}}$ (H). n = 4 mice.

(I) OCR measurement of hepatocytes from WT and Mrs2^−/− normalized to total protein content. n = 3 mice.

(J) Basal and maximal respiration and proton leak from (I). Data represent individual wells from three different hepatocyte isolations in each group. All data shown as mean ±SEM; ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05, n.s. = not significant.