Vpr transgenic mice develop hepatosteatosis. (A) Increased liver mass (normalized to body weight) was present in Vpr-Tg compared to WT mice of 14 week old mice (n = 5–6 per group) and 28 week old mice (n = 4–5 per group) and sVpr- compared to vehicle-treated mice (n = 7 per group). (B) Increased liver triglyceride content was present in Vpr-Tg mice by TLC (n = 3 per group) and (C) by colorimetric assay (n = 5–6 per group). (D) Steatosis was observed in Vpr-Tg liver (hematoxylin-eosin stain). Left panel shows liver parenchyma around a centrilobular vein in WT mouse, with a pattern of microsteatosis (black arrows). Right panel shows peri-centrilobular area of liver in Vpr-Tg mouse, with both microsteatosis (black arrows) and macrosteatosis (white arrows). Scale bar = 50 μm. (E) Oil Red O–stained liver sections of 14-week Vpr-Tg show increased lipid accumulation compared to WT mice. Bar graph shows quantification of ORO-stained area. (F) Oil Red O–stained liver sections of 28-week Vpr-Tg show progressive lipid accumulation compared to WT mice. Bar graph shows quantification of ORO-stained area. Values are mean ± SE. *P < 0.05, **P < 0.01, ***P < 0.001.