Reconstitution of hepatic MTP expression in chow-fed MTPLKO mice reduces hepatosteatosis and restores CREBH processing and hepatic apoA-IV expression. MTPLKO mice were given Ad-hMTP or control Ad-LacZ by retro-orbital injection. Three days after adenoviral injection, mice were fasted overnight to induce acute steatosis. Liver and plasma were then harvested to measure hepatic TG content, CREBH processing, and apoA-IV expression, as described in the legend to Fig. 2. A, immunoblot of hepatic hMTP expression and plasma apoB protein mass; B, plasma TG concentration; C, liver TG content; D, CREBH mRNA levels normalized to MTPLKO mice given Ad-LacZ; E, immunoblot of full-length precursor CREBH (CREBH (F)) and the processed mature CREBH (CREBH (N)) in isolated microsomal and nuclear fractions (numbers above CREBH (N) identify individual mice); F, liver mRNA abundance of apoA-IV, apoC-III, apoB, and apoA-V, normalized to MTPLKO mice given Ad-LacZ. B–D and F, mean ± S.D. (error bars), n = 3/group. *, p < 0.05. Similar results were obtained in a separate experiment using different adenoviral doses.