Effects of AICAR, Compound C and Metformin administration in metabolic and angiogenic behavior in human microvascular endothelial cells (HMECs)

Introduction: An important feature of type 1 diabetes (T1D) is the existence of the so-called “angiogenic paradox”, a phenomenon in which the same organism presents exacerbated vascularization in certain organs (e.g. kidney) and impaired angiogenesis in others (e.g. heart). AMPK is an energy sensor that targets carbohydrate and lipid metabolism by modulating gene expression and is an insulin sensitizing molecule, rendering this kinase an ideal therapeutic target. Objectives: To study the effects of administration of AICAR, Compound C and Metformin on the angiogenic behavior of human microvascular endothelial cells (HMEC-1), as well as, to analyze the possible changes in expression of genes related with metabolism. Methodology: HMEC-1 were cultured in with two different glucose concentration: 5.5mM D-Glucose (low glucose (LG)) or 20mM D-Glucose (high glucose (HG)) and treated with AICAR, Compound C or Metformin to evaluate angiogenic behaviour by proliferation, migration and tube capillary formation assays. Alterations of genes related with metabolism and angiogenesis were verified by q RT-PCR. Results: All treatments induced a decrease in proliferation, migration and tube formation in HMEC-1 when subjected to both LG and HG. The analysis of metabolic and angiogenic gene expression showed some alterations: Kdr, Pfkfb2, Tgfb2, Timp2 and Jag1 gene expression were increased when treated with all compounds vs control group; Smad5 reduced with AICAR treatment, but increased with Compound C and Metformin in LG condition. Timp2 expression was increased with AICAR and Compound C treatment and decreased with Metformin administration when compared to LG control. Conclusion: Administration of AICAR, Compound C and Metformin alters the angiogenic behavior of HMEC-1 and can modulate the expression of important genes related to angiogenesis and cellular metabolism. These preliminary results bring new insights in the crosstalk between endothelial metabolism and angiogenic behavior and may be useful to develop new therapeutic approaches to counteract diabetic complications.