Perindopril inhibits myocardial apoptosis in mice with acute myocardial infarction through TLR4/NF-κB pathway

Objective: To explore the anti-apoptotic effect of perindopril on myocardial cells in mice with acute myocardial infarction (AMI).

Materials and methods: A total of 48 mice were randomly divided into 4 groups before intervention, namely sham operation group (Sham group, n=12), AMI group (n=12), 1.5 mg/kg perindopril treatment group (Perindopril group, n=12), and 1.5 mg/kg perindopril treatment and Toll-like receptor-4 (TLR4) knockout group (TLR4-/-Perindopril group, n=12). Mice in the control group and AMI group were gavaged with normal saline, and those in the Perindopril group and TLR4-/-Perindopril group were gavaged with perindopril for 7 d. On the 4th day after drug administration, mice in the AMI group, Perindopril group and TLR4-/-Perindopril group were subjected to the ligation of the anterior descending coronary artery to induce AMI, and those in the Sham group underwent the same operation, but had a loose knot at the anterior descending coronary artery. At 24 h after the above operation, color echocardiography was performed on mice to observe changes in cardiac function. Then, the mice were sacrificed. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick end labeling (TUNEL) assay was carried out to determine myocardial Apoptosis. Immunohistochemistry and Western blotting technique were employed to detect the protein expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), TLR4 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p50 in infarction zones. The messenger ribonucleic acid (mRNA) expression levels of TLR4 and NF-κB p50 in infarction zones were measured via Reverse Transcription-Polymerase Chain Reaction (RT-PCR).

Results: Perindopril could significantly reduce the number of apoptotic myocardial cells after AMI. Mouse echocardiography showed that ejection fraction (EF), left ventricular fractional shortening (FS), left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD) of AMI mice in the Perindopril groups were markedly superior to those in the AMI group. AMI mice in the Perindopril group had decreased expression levels of Bax protein and TLR4 and NF-κB p50 mRNA and protein, as well as the Bax/Bcl-2 ratio. Knockout of TLR4 attenuated the effect of perindopril in alleviating myocardial Apoptosis after AMI.

Conclusions: Perindopril inhibits myocardial Apoptosis in mice with AMI through the TLR4/NF-κB pathway.