Abstract 313: Nonionic Acid is a Target Metabolite of Diabetic Microvasculopathy
Aim: The purpose of this study is to screen the target metabolites of diabetic microangiopathy in heart by use of whole heart metabolome analysis. Methods: Diet-induced type 2 diabetic mouse were divided into two groups; control and those treated with diabetic remedy GLP-1 receptor agonist Ex-4 for 5 weeks. Mice were euthanized and analyzed at the age of 16 week-old. Results: The capillary density of the T2DM was reduced as compared to those non-diabetic counterparts, which was restored by Ex4 treatment. Changes in angiogenic signals detected by immunoblotting analysis revealed that the phosphorylation levels of eNOS and AMPK were elevated by Ex-4, but those Akt remained unchanged. Tube formation assay revealed that Ex-4 increased tube length and branch points in HUVECs. Consistently with the trend that was observed in vivo experiment, AMPK and eNOS phosphorylation levels were enhanced by Ex4 without affecting Akt phosphorylation. To screen the candidate metabolites that is responsible for the diabetic microvasculopathy in GLP-1-dependent fashion, we performed metabolome analysis by using the whole heart of each mouse. The hierarchical cluster analysis revealed that nonanoic acid (NNA) was the only metabolite that increased in type 2 diabetic mice with concomitant decline by Ex-4 treatment. We next examined the impact of nonanoic acid on in vitro angiogenesis and found that NNA suppressed tube length and branch points in HUVECs in a dose-dependent fashion. Interestingly, NNA canceled eNOS and AMPK phosphorylation that was enhanced by Ex4. Conclusion: GLP-1 ameliorated diabetic microvasculopathy via the AMPK and eNOS axis. NNA is presumably one of the novel anti-angiogenic metabolites that causes diabetic microangiopathy.