Research
Discovery of microvascular miRNAs using public gene expression data: miR-145 is expressed in pericytes and is a regulator of Fli1
- † Equal contributors
1 Wallenberg Laboratory for Cardiovascular Research, Bruna Stråket 16, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
2 Institute of Biomedicine, University of Gothenburg, SE-405 30 Gothenburg, Sweden
3 Department of Medical Biochemistry and Microbiology, Uppsala University, Husargatan 3, SE-751 23 Uppsala, Sweden
4 Department of Medical Biochemistry and Biophysics, Division of Matrix Biology, Lab of Vascular Biology, Karolinska Institutet, Scheeles väg, 2 A:3-P:4, SE-171 77 Stockholm, Sweden
5 Inserm U574, Hôpital Necker-Enfants Malades, Equipe Avenir Tour Lavoisier, 6e étage, 149 rue de Sèvres, 75015 Paris, France
6 Université Paris Descartes, Hôpital Necker-Enfants Malades, Equipe Avenir Tour Lavoisier, 6e étage, 149 rue de Sèvres, 75015 Paris, France
7 Department of Medicine and Centre for Molecular Medicine, University of Cologne, Kerpener Str. 62, 50937 Köln, Germany
8 Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Kerpener Str. 62, 50937 Köln, Germany
Genome Medicine 2009, 1:108 doi:10.1186/gm108
Published: 16 November 2009Abstract
Background
A function for the microRNA (miRNA) pathway in vascular development and angiogenesis has been firmly established. miRNAs with selective expression in the vasculature are attractive as possible targets in miRNA-based therapies. However, little is known about the expression of miRNAs in microvessels in vivo. Here, we identified candidate microvascular-selective miRNAs by screening public miRNA expression datasets.
Methods
Bioinformatics predictions of microvascular-selective expression were validated with real-time quantitative reverse transcription PCR on purified microvascular fragments from mouse. Pericyte expression was shown with in situ hybridization on tissue sections. Target sites were identified with 3' UTR luciferase assays, and migration was tested in a microfluid chemotaxis chamber.
Results
miR-145, miR-126, miR-24, and miR-23a were selectively expressed in microvascular fragments isolated from a range of tissues. In situ hybridization and analysis of Pdgfb retention motif mutant mice demonstrated predominant expression of miR-145 in pericytes. We identified the Ets transcription factor Friend leukemia virus integration 1 (Fli1) as a miR-145 target, and showed that elevated levels of miR-145 reduced migration of microvascular cells in response to growth factor gradients in vitro.
Conclusions
miR-126, miR-24 and miR-23a are selectively expressed in microvascular endothelial cells in vivo, whereas miR-145 is expressed in pericytes. miR-145 targets the hematopoietic transcription factor Fli1 and blocks migration in response to growth factor gradients. Our findings have implications for vascular disease and provide necessary information for future drug design against miRNAs with selective expression in the microvasculature.
