Elevated Insulin Secretion from Liver X Receptor-Activated Pancreatic β-Cells Involves Increased de Novo Lipid Synthesis and Triacylglyceride Turnover
Endocrinology Green et al. 150: 2637 Supplemental Data
Supplemental Data
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- Supplemental Figure 1 - Supplementary Figure 1. LXR activation increases lipogenic gene expression in human islets. Isolated human islets were cultured for three days in medium supplemented without (control) or with 10 μ M T0901317. Total RNA was isolated and mRNA expression levels were determined by real-time RT-PCR. Values are mean ± SEM, n = 3.
- Supplemental Figure 2 - Supplementary Figure 2. LXR activation increases de novo lipid synthesis in human islets. Human islets were cultured for 36 h in medium containing 11.1 or 22.2 mM without or with 5 μ M T0901317. Islet were then incubated for 12 hrs under the same conditions in the presence of 1 μ Ci 2-14Cacetic acid. Assimilation and distribution of 14C into complex lipids and fatty acids species was determined as described for Figure 2. Panel A. Incorporation of 14C into triacylglyceride, cholesterol, cholesterol esters, and free fatty acids. Panel B. Incorporation of 14C into specific fatty acids. Values are means, n = 2.
- Supplemental Figure 3 - Supplementary Figure 3. Effect of etomoxir, triacsin C or orlistat on glucose-induced insulin release from INS-1 cells cultured in 4 mM glucose with or without T0901317. INS-1 cells were incubated for 48 h in 4 mM glucose with or without T0901317 (10 μ M). Insulin release (60 min) in response to 2 or 20 mM glucose was then assessed in the presence or absence of 100 μ M etomoxir (A), 10 μ M triacsin C (B) or 50 μ M orlistat (C). Values are mean ± SEM for three to six independent experiments. *, p
- Supplemental Figure 4 - Supplementary Figure 4. Knockdown of SCD with siRNA does not inhibit insulin release from LXR-activated INS-1 cells. INS-1 cells were electrophorated in the presence of 100 nM control siRNA or siRNA against SCD1 and 2 (Dharmacon, Inc). Cells were cultured for 12 hrs in 11.1 mM glucose and then cultured for 48 h in 16.7 mM glucose with or without T0901317. After which mRNA levels, MUFA synthesis from 14C-labeled palmitate, and insulin release were assessed. Panel A. SCD siRNA blocked the ability of T0901317 to increase SCD 1 and 2 mRNA levels. SCD siRNA, however, did not affect T0901317 induction of delta 6 desaturase (D6D). n = 3. Panel B. Knockdown of SCD decreased the conversion of 14C-palmitate (16:0) to palmitoleate (16:1) or oleate (18:1). n = 3. Panel C. Knockdown of SCD failed to decrease insulin release from LXR-activated cells cultured in 16.7 mM glucose. n = 6.
- Supplemental Table 1 - Supplemental Table 1