Figure 7. Stable knockdown of ACSL4 mRNA and ACSL4 protein in the INS-1 832/13 cell line inhibits arachidonate ACSL enzyme activity more than palmitate ACSL enzyme activity and inhibits glucose-stimulated insulin release.

A. mRNA values are the mean ± SE of three cell preparations. Insulin release values are the mean ± SE of 12–29 replicate incubations of cells incubated in the presence of 11.1 mM glucose for 1 h. Glucose-stimulated insulin release of the HygC control cell line that contains a non-targeting shRNA sequence was 20.4 mU +/− 1.4 (mean +/− SE insulin/mg cell protein/h. ACSL enzyme activity was measured with arachidonate or palmitate as a substrate. ACSL enzyme activities of the HygC control were similar to the values of the parent INS-1 832/13 cell line shown in Table 1 with the activity with arachidonate equal to 1.8 fold that with palmitate as a substrate (N = ≥ 6 for each condition). All values are expressed relative to the HygC control values equal to 100%. ^ap < 0.05, ^bp < 0.01 and ^cp < 0.001 vs control. B. Immunoblot with 10 μg protein/lane. The density of each band is shown in percent relative to the pHygC control cell line. Actin bands show relatively equal loading of protein across lanes.