FIGURE 8.

Effects of GDE4 interference on intracellular lyso-PC metabolism. 3T3-L1 adipocytes were transfected with control siRNA (siCont) or GDE4 siRNA (siGDE4). A, 24 h after transfection, total RNAs were extracted and subjected to quantitative PCR analyses to examine expression levels of GDE4 mRNA. The level of β-actin transcript was used as a control. B, 48 h after transfection, whole cell lysates were obtained, and total protein extracts (10 μg/lane) were subjected to SDS-PAGE followed by Western blotting using an anti-GDE4 antibody. The filter was stained with Coomassie Brilliant Blue (CBB) as a control of protein loading. C, 48 h after transfection, intracellular lyso-PC (16:0), phosphocholine, and choline levels were measured as described under “Experimental Procedures.” Data are means of triplicate experiments (mean ± S.E.). Statistical significance was determined by unpaired Student's t test. *, p < 0.05; **, p < 0.01.