Felix Fleißner1, Virginija Jazbutyte1, Jan Fiedler1, Shashi Kumar Gupta1, Xiaoke Yin1, Qingbo Xu1, Paolo Galuppo1, Susanne Kneitz1, Manuel Mayr1, Georg Ertl1, Johann Bauersachs1, Thomas Thum1
1From the Institute of Molecular and Translational Therapeutic Strategies (F.F., V.J., J.F., S.K.G., T.T.) and the Department of Cardiology and Angiology (F.F., T.T.), Hannover Medical School, Hannover, Germany; King’s College London School of Medicine (X.Y., Q.X., M.M.), Cardiovascular Division, London, United Kingdom; the Department of Medicine I/Cardiology (P.G., G.E., J.B.), Julius-Maximilians-University, Würzburg, Germany; and Microarray Core Facility (S.K.), Interdisciplinary Collaborative...
Tóm tắt
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.
