Short Communication: Asymmetric Dimethylarginine Impairs Angiogenic Progenitor Cell Function in Patients With Coronary Artery Disease Through a MicroRNA-21–Dependent Mechanism

Abstract

Rationale: The endogenous nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA) is increased in patients with coronary artery disease and may regulate function of circulating angiogenic progenitor cells (APCs) by small regulatory RNAs. Objectives: To study the role of microRNAs in ADMA-mediated impairment of APCs. Methods and Results: By using microarray analyses, we established microRNA expression profiles of human APCs.We used ADMA to induce APC dysfunction and found 16 deregulated microRNAs. We focused on miR-21, which was 3-fold upregulated by ADMA treatment. Overexpression of miR-21 in human APCs impaired migratory capacity. To identify regulated miR-21 targets, we used proteome analysis, using difference in-gel electrophoresis followed by mass spectrometric analysis of regulated proteins. We found that transfection of miR-21 precursors significantly repressed superoxide dismutase 2 in APCs, which resulted in increased intracellular reactive oxygen species concentration and impaired nitric oxide bioavailability. MiR-21 further repressed sprouty-2, leading to Erk Map kinase-dependent reactive oxygen species formation and APC migratory defects. Small interference RNA-mediated superoxide dismutase 2 or sprouty-2 reduction also increased reactive oxygen species formation and impaired APC migratory capacity. ADMA-mediated reactive oxygen species formation and APC dysfunction was rescued by miR-21 blockade. APCs from patients with coronary artery disease and high ADMA plasma levels displayed >4-fold elevated miR-21 levels, low superoxide dismutase 2 expression, and impaired migratory capacity, which could be normalized by miR-21 antagonism. Conclusions: We identified a novel miR-21-dependent mechanism of ADMA-mediated APC dysfunction. MiR-21 antagonism therefore emerges as an interesting strategy to improve dysfunctional APCs in patients with coronary artery disease. (Circ Res. 2010;107:138-143.)Key Words: endothelial progenitor cells Ⅲ microRNAs Ⅲ ADMA Ⅲ coronary artery disease Ⅲ oxidative stress T he endogenous nitric oxide synthase (NOS) inhibitor asymmetrical dimethylarginine (ADMA) is a major risk factor in patients with coronary artery disease (CAD). [1][2][3] Functionally, ADMA induces dysfunction of circulating angiogenic progenitor cells (APCs) (early outgrowth endothelial progenitor cells or circulating angiogenic cells) 4 and impairs neovascularization 5 by direct inhibition of the endothelial NOS. 6 NO plays a crucial role in mobilization, differentiation, and function of APCs, 7,8 whereas oxidative stress impairs APC function. 9,10 MicroRNAs (miRNAs) are a class of highly conserved, noncoding short RNA molecules that regulate a large portion of the genome. MiRNAs play a crucial role in cardiac biology, and miRNA dysregulation is often found in cardiovascular diseases. 11 Knockdown of the miRNA-processing enzyme Dicer in endothelial cells reduces the formation of capillary-like structures by profound dysregulation of angiogenesis-related genes, 12 and Dicer-deficient mice die from imp...

MicroRNAs and Stem Cells

“…6 However, cardiovascular risk factors and aging were shown to impair the functions of this endogenous pool of proangiogenic cells. 84,85 The functional impairment of these cells in patients with coronary artery disease was associated with an increased expression of miR-21 86 and a dysregulation of other vascular miRs. 87 Interestingly, antagonizing miR-21 led to an improved functionality of proangiogenic cells from patients with coronary artery disease who otherwise experienced oxidative stress mediated by an upregulation of miR-21 in this disease state.…”

Clinical significance and expression of microRNA in diabetic patients with erectile dysfunction

“…Villeneuve et al (38,39) found that miR-125b may increase the expression of inflammatory genes in vascular endothelial cells to cause endothelial dysfunction. Weber et al (40) and Fleissner et al (41) also found that miR-21 was able to reduce the rate of apoptosis in vascular endothelial cells and promote the release of nitric oxide to protect the vascular endothelium. Caporali et al (42) reported that inhibition of miR-15 improved endothelial function in culture conditions mimicking diabetes mellitus (high D-glucose), and CCNE1 and CDC25A were direct miR-15 targets.…”

Current Status of Cell-Based Therapy for Heart Failure

“…[36] Together with other studies, which show an impairment of migration and angiogenic capacity of adult bone marrow-derived mononuclear cells, [66,67] this might contribute to the limited capacity of BM-MNCs in clinical trials to effectively impact on cardiac function. In this respect a phase I trial was recently published using allogeneic bone marrow derived cells [68] from healthy donors as an off-the-shelf product, that may circumvene impairment of autologous cell function in patients with cardiovascular disease.…”