Letter Regarding Article, "MicroRNA-155 Exerts Cell-Specific Antiangiogenic but Proarteriogenic Effects During Adaptive Neovascularization".

We read with interest the article by Pankratz and colleagues1 in Circulation in which the authors identified miR-155 as a dual player in postischemic neovascularization following hindlimb ischemia in mice. Although this study elegantly describes an antiangiogenic but proarteriogenic role for miR-155 in postischemic neovascularization, it remains unclear on several other aspects.1 Using microRNA expression profiling, miR-155 was identified as one of the strongest downregulated miRs at 7 days after induction of hindlimb ischemia.1 However, in a previous study from 2010 by the same research group, Grundmann et al already used microarrays to explore microRNA expression patterns during adaptive neovascularization in the same mouse model.2 MicroRNA analyses in both studies were performed on RNA …