Response to Letter Regarding Article, "MiR-125b Is Critical for Fibroblast-to-Myofibroblast Transition and Cardiac Fibrosis".

We appreciate Li and colleagues for their interest in our recent publication on miR-125b and cardiac fibrogenesis.1 In their letter, the authors commented that “it is not known whether miR-125b is cell specific.” In fact, miR-125b is a highly conserved microRNA throughout diverse species from nematodes to humans and is expressed in different types of organs. Notably, we have previously reported upregulation of miR-125b in cardiac endothelial-to-mesenchymal transition, demonstrating that miR-125b is indeed not fibroblast specific.2 The authors were also concerned about potential side effects of inhibition of miR-125b in cardiomyocytes. We reported that miR-125b was upregulated during cardiac fibrosis, and the primary focus of our study was to normalize the levels of …