Fig. 5.

Hepatic Patt1 knockout reduces fatty acid uptake and lipid synthesis. (A, B) Among the two indicated genes participating in fatty acid uptake, CD36 was downregulated in the liver of male Patt1 LKO mice at ages 9 weeks and 31 weeks as determined by real-time PCR. n = 4–6/group. (C) Fatty acid uptake in hepatocytes of Patt1 LKO mice was attenuated as measured by ³H-palmitate incorporation. Mouse primary hepatocytes were prepared from 10- to 15-week-old mice. (D, E) Among the indicated key regulators in lipid metabolism, PPARα was downregulated in 9-week-old male Patt1 LKO mice, and PPARγ was reduced in the liver of 9- and 31-week-old male Patt1 LKO mice. n = 4–6/group. (F, G) Among the indicated enzymes responsible for fatty acid and triglyceride synthesis, ACL was decreased in the liver of 9- and 31-week-old male Patt1 LKO mice. n = 4–6/group. (H, J) Among the enzymes involved in lipid synthesis, ACL, FAS, and ELOVL6 protein levels were downregulated, and the protein level of phosphorylated ACC was upregulated in the liver of 9- and 31-week-old male Patt1 LKO mice. n = 4–6/group. (I, K) Quantification of the protein levels in (H and J). (L) The activity of ACC, the rate-limiting enzyme in lipid synthesis, was attenuated in the liver of male Patt1 LKO mice. n = 8/group. (M) Lipid synthesis in hepatocytes of Patt1 LKO mice was decreased as measured by the incorporation of ³H-glucose into lipid. Mouse primary hepatocytes were prepared from mice at ages 10–15 weeks. *P < 0.05, **P < 0.01.