microRNA-222 controls neovascularization by regulating signal transducer and activator of transcription 5A expression.
OBJECTIVE
Inflammatory stimuli released into atherosclerotic plaque microenvironment regulate vessel formation by modulating gene expression and translation. microRNAs are a class of short noncoding RNAs, acting as posttranscriptional regulators of protein-coding genes involved in various biological processes, including vascular cell biology. Among them, microRNA-221/222 (miR-221/222) seem to negatively modulate vascular remodeling by targeting different target genes. Here, we investigated their potential contribution to inflammation-mediated neovessel formation.


RESULTS
We used quantitative real-time RT-PCR amplification to analyze expression of 7 microRNAs previously linked to vascular biology, such as miR-17-5p, miR-21, miR-126, miR-210, miR-221, miR-222, and miR-296 and found high levels of expression for all of them in quiescent endothelial cells. However, miR-126, miR-221, miR-222, and miR-296 turned out to be down-modulated in endothelial cells exposed to inflammatory stimuli. Applying a gain-of-function approach, we demonstrated that, among them, only miR-222 was involved in inflammation-mediated vascular remodeling. In addition, we identified signal transducer and activator of transcription 5A (STAT5A) as a bona fide target of miR-222 and observed that miR-222 negatively correlated with STAT5A expression in human endothelial cells from advanced neovascularized atherosclerotic lesions.


CONCLUSIONS
We identified STAT5A as a novel miR-222 target, and this finding opens up new perspectives for treatment of vascular diseases.
Dentelli
Patrizia
P
Department of Internal Medicine, University of Torino, Torino, Italy.
Rosso
Arturo
A
Orso
Francesca
F
Olgasi
Cristina
C
Taverna
Daniela
D
Brizzi
Maria Felice
MF
D020413:3' Untranslated Regions; D000818:Animals; D050197:Atherosclerosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002478:Cells, Cultured; D015536:Down-Regulation; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology / Q000637:transplantation; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D018836:Inflammation Mediators / Q000378:metabolism; D007377:Interleukin-3 / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D018919:Neovascularization, Physiologic / Q000235:genetics; D034622:RNA Interference; D050799:STAT5 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
D020413:3' Untranslated Regions; D016222:Fibroblast Growth Factor 2; D018836:Inflammation Mediators; D007377:Interleukin-3; D035683:MicroRNAs; D050799:STAT5 Transcription Factor; D025521:Tumor Suppressor Proteins; C508596:IL3 protein, human; C525709:MIR221, human; C525710:MIR222, human; C494092:STAT5A protein, human