ADAMTS4 and atrial fibrillation: Although no significant differences were detected in the expression of a disintegrin and metalloproteinase with thrombospondin type 1 motif 4 (Adamts4) or tissue inhibitor of metallopeptidase 1 (Timp1), mRNA levels of matrix metallopeptidase 3 (Mmp3) were increased in AF cells following acute exposure to CTS at 0.1 Hz (significantly increased at 2 hours compared to unloaded controls; fold change = 1.6 ± 0.16) (Figure 6B).