Figure 7. Hepatic LPAAT Activity of Wild-Type and Adiponutrin-Deficient Mice.

Five hours postfeeding, male wild-type (WT) and Adpn-KO mice fed a chow diet or HSD were sacrificed, and the liver was excised.

(A) Relative liver Adpn mRNA expression as determined by RT-qPCR was normalized to β-actin as a reference gene and compared to WT mice fed chow diet, n = 6.

(B) LPAAT activity was determined in liver tissue homogenates (20 μg total protein), n = 5.

(C) LD-associated LPAAT activity was determined in freshly prepared liver LDs (10 μg LD protein). Data are representative of three independent diet studies, n = 4 or 5. Data are shown as mean ± SD. Statistical significance was determined by a two-tailed student’s t test, **p < 0.01, ***p < 0.001.

(D) Phosphatidic acid (PA) to lysophosphatidic acid (LPA) ratio in WT and Adpn-KO mice liver lipid extracts. Liver samples were collected from chow diet- and HSD-fed WT and Adpn-KO mice after 2 min organ perfusion with Krebs-Henseleit Buffer 2. For the determination of LPA and PA concentrations, hepatic glycerophospholipids were extracted using a modified Bligh and Dyer method (Bligh and Dyer, 1959). Lipids were quantified by LC/MS/MS (details described in the Supplemental Experimental Procedures), n = 6. Data are shown as mean ± SEM. Statistical significance was determined by post hoc analysis, ***p < 0.001.