Wu et al13 have revealed that the MAPK signaling pathway is related to acute MI. Therefore, in the present study, we corroborated the changes in the MAPK signaling pathway in acute MI rats. Meanwhile, the protein expressions of p-MMK3/6 and MKK3/6 in myocardial cells in both model group and sham operation group were analyzed (Figures 4A and 4B). The results discovered that no significant changes were observed in the protein levels of MKK3/6 in the model group, while p-MKK3/6 was remarkably elevated. These results suggested that TGF-β1 activated MKK3/6 in the MAPK signaling pathway.