Abstract 20841: Micrornas Markedly Increased Expression of Angiogenic Suppressor Micro-rnas -92a, 16 and 21 in Lin-/cd34+ Cells From Human Cad Patients.
Introduction: Bone marrow (BM) EPCs contribute to vascular repair and regeneration and defects in number and/or function of EPCs may contribute to atherosclerosis and coronary artery disease (CAD). Autologous stem cell therapy for CAD requires functionally competent EPCs in the host BM. We hypothesized that dysregulated expression of micro-RNAs causes functional defects in bone marrow EPCs that promote CAD progression and impair autologous stem cell therapy.
Objective: Compare mRNA and miR profiles of CD34+/Lin- EPCs from CAD, non-CAD and healthy volunteers and functionally validate the effects of target miRs on angiogenic potential.
Methods: BM was collected from 5 CAD, 4 non-CAD and 2 healthy volunteers, CD34+/Lin- cells were isolated and subjected to microarray and micro-RNA profiling. HUVECs were transfected with pre and anti-miRs of miRs-92a, -21, -16, -1 (control), individually and in combination. HUVEC tube formation, VEGF-mediated migration and proliferation were quantified. Protein and RNA were quantified by western blot and RT-PCR.
Results: Micro-RNA analysis revealed 14 miRs that were profoundly increased selectively in CAD samples including miRs-92a, -21, and −16. All pre-miRs except miR-1 significantly inhibited tube formation (p<0.01); the greatest inhibition was seen when all 3 miRs were combined. VEGF-mediated migration was significantly blocked by all 3 pre-miRs (p<0.05). Western blotting showed reductions of ITGα5, MKK4, Enos, Bcl2 and Akt by mir-92a, and CCND1, CCNE1, and BCL2 by mir16.
Conclusions: The expression of miRs-92a, 16 and 21 is markedly increased in CD34+ EPCs from patients with CAD. These miRs repress angiogenesis and may drive disease progression. Neutralization of these miRs is predicted to improve stem cell therapy for CAD patients.
- © 2010 by American Heart Association, Inc.