The target miRNAs for PLOD1 were selected by TargetScan (http://www.targetscan.org/vert_72/), based on the context++ score (22 (link)). The plasmids of the wildtype p3'-UTR-PLOD1 and the mutant p3'-UTR-PLOD1-mut were generated. For the dual-luciferase reporter assay, plasmids were co-transfected into AMSCs using LipofectamineTM 2000 system (Invitrogen, USA).