Abstract 14: The Anti-atherosclerosis ABCA1 Agonist CS6253 Confer Glucose Control by Improved Pancreas Beta-cell Insulin Secretion and Enhanced Peripheral Insulin Utility
Background: Type 2 Diabetes Mellitus (T2DM) is associated with high cardiovascular disease (CVD) risk. Addressing the underlying atherogenesis and diabetes causing CVD in T2DM is important. CS6253 is an ABCA1 agonist peptide derived from the C-terminal of apoE that has shown macrophage specific reverse cholesterol transport, anti-atherosclerosis and anti-diabetic properties. Further studies were carried out to characterize metabolic effects. Methods: CS6253 was incubated with a) INS-1 823/13 cells to assess effects on insulin secretion and b) with L6-Glut4myc rat myoblasts to assess glucose uptake properties. Diet Induced Obesity (DIO) mice, i.e. C57BL/6 mice that had been fed 60% high-fat diet for 6 weeks, were treated with CS6253 and Glucose Tolerance Tests (GTT) performed after overnights fasting administering glucose 1g/kg ip. Results: CS6253 1mg/mL incubated for 2 hours under standard conditions with 3mM glucose showed a 3-fold increase in insulin secretion compared to control, i.e. 232(32) vs. 79(7) ng/M cells, p<0.001. 3 H-glucose uptake by CS6253 peptide in L6-Glut4myc rat myoblasts increased insulin’s glucose uptake capacity from 3800 to 4619 DPM/well, p<0.001 . CS6253 alone had no effect on 3 H-glucose uptake compared to control. DIO mice were treated with CS6253 30mg/kg sc alternate days or PBS control for 16 weeks. GTTs were performed after 2, 6 and 15 weeks treatment showing 39%, 45% and 57% reductions in the glucose-AUC compared to control, respectively, p<0.01 for all time points. Insulin response to GTT after 5 weeks treatment showed a strong improvement of the insulin-curve by CS6253, p<0.05 vs. placebo. CS6253 treated DIO mice showed a non-significant body weight decrease and a 17% reduction in liver weight, 5.28g vs. 4.36g, p<0.01. Discussion: CS6253 shows potent, sustained and increased anti-diabetic actions over the 16 weeks treatment period in DIO mice. In vivo and in vitro studies show improved pancreas β-cell function with increased glucose-mediated insulin secretion and also insulin sensitizing properties. CS6253’s combined anti-diabetic and anti-atherosclerosis properties suggest utility in the treatment of CVD and T2DM.