Skip to main content
. 2021 Aug 9;24(9):102963. doi: 10.1016/j.isci.2021.102963

Figure 4.

Figure 4

Effects of medium-chain fatty acids on long-chain fatty acid-induced CCK secretion and increase in [Ca2+]i through GPR120 and GPR40

(A) CCK concentration in STC-1 cell supernatant after addition of control (DMSO, 0.1%), C18:3 (20-100μM), C8:0 (100μM) and C10:0 (100μM). White circles and gray circles indicate control and C18:3, respectively. The black circles indicate C8:0 and C10:0. The experiment was performed in triplicate twice, and representative data are presented. Data indicate the mean ± SEM. Statistical significance was calculated by One-way ANOVA with Tukey’s test using SPSS statistics. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001 vs. control.

(B) CCK concentration in STC-1 cell supernatant after addition of C18:3 (50 μM), C18:3 (50 μM) + C8:0 (100 μM), and C18:3 (50 μM) + C10:0 (100 μM). Gray circles indicate C18:3, and black circles indicate C18:3 + C8:0 and C18:3 + C10:0. The experiment was performed in triplicate twice, and representative data are presented. Data indicate the mean ± SEM. Statistical significance was calculated by One-way ANOVA with Tukey’s test using SPSS statistics. ∗∗∗P < 0.001 vs. C18:3.

(C and D) Relative [Ca2+]I in T-REx GPR120 cells and T-REx GPR40 cells after addition of C18:3, C18:1, C8:0, or C10:0. Blue circles, purple circles, orange circles, and yellow circles indicate C18:3, C18:1, C8:0, and C10:0, respectively. The experiment was performed in duplicate four times, and representative data are presented. Data indicate the mean ± SEM. Statistical significance was calculated by One-way ANOVA with Tukey’s test using SPSS statistics. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001 vs. after 1.56 × 10−6 M each fatty acid loading.

(E and F) Relative [Ca2+]i in T-REx GPR120 cells and T-REx GPR40 cells after addition of C18:3 (100 μM) + C8:0 or C10:0. Red circles indicate C18:3 + C8:0, and yellow circles indicate C18:3 + C10:0. The experiment was performed in duplicate four times, and representative data are presented. Data indicate the mean ± SEM. Statistical significance was calculated by One-way ANOVA with Tukey’s test using SPSS statistics. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001 vs. C18:3 (100 μM) alone.

(G) (Left) GPR120 mRNA expression in STC-1 cells after GPR120 knockdown. The experiment was performed in triplicate twice, and representative data are presented. Data indicate the mean ± SEM. Statistical significance was calculated by Student’s t-test. ∗∗∗P < 0.001 vs. negative siRNA. (Right) CCK concentration in STC-1 cell supernatant at 1 hr after each fatty acid loading following GPR120 knockdown. The experiment was performed in triplicate twice, and representative data are presented. Data indicate the mean ± SEM. Statistical significance was calculated by One-way ANOVA with Tukey’s test using SPSS statistics. #P < 0.05 vs negative siRNA.

(H) (Left) GPR40 mRNA expression in STC-1 cells after GPR40 knockdown. Data indicate the mean ± SEM. The experiment was performed in triplicate twice, and representative data are presented. Statistical significance was calculated by Student’s t-test. ∗∗∗P < 0.001 vs. control. (Right) CCK concentration in STC-1 cell supernatant at 1 hr after each fatty acid loading following GPR40 knockdown. The experiment was performed in triplicate twice, and representative data are presented. Data indicate the mean ± SEM. Statistical significance was calculated by One-way ANOVA with Tukey’s test using SPSS statistics. #P < 0.05 vs negative siRNA. ∗∗P < 0.01 vs. C18:3 GPR40 siRNA.