Retracted: Tanshinone IIA prevents left ventricular remodelling via the TLR4/MyD88/NF‐κB signalling pathway in rats with myocardial infarction

Abstract

In this study, we aim to investigate the role of tanshinone IIA in myocardial infarction (MI), especially in left ventricular remodelling (VR) and the underlying mechanism involving the TLR4/MyD88/NF‐κB signalling pathway. Sprague‐Dawley (SD) rats (n = 96) were selected, and 12 of them underwent sham surgery. The remaining 84 rats were subjected to MI modelling. HE and MT staining were carried out to estimate infract size, histopathological changes and fibrosis degree. Macrophage infiltration and cardiomyocyte apoptosis were evaluated by immunohistochemistry and TUNEL staining. Reverse transcription quantitative polymerase chain reaction (RT‐qPCR) and Western blotting were used to determine the expression levels of TLR4, MyD88 and NF‐κB. Serum levels of IL‐2, IL‐6, IL‐8, TNF‐a, procollagen I Cpropeptide (PICP), and procollagen III N‐propeptide (PIIINP) were measured using enzyme‐linked immunosorbent assay (ELISA). The heart weight/body weight, mean arterial pressure (MAP), left ventricular end‐systolic pressure (LVESP), +dP/dt and −dP/dt increased while the ventricular function and the left ventricular end‐diastole pressure (LVEDP) decreased in MI rats. Compared with the rats undergoing sham surgery, MI rats showed larger infarct size, severer fibrosis, higher expression levels of TLR4, NF‐κB‐P65, MyD88, IL‐2, IL‐6, IL‐8, TNF‐a, PICP and PIIINP as well as enhanced macrophage infiltration, cardiomyocyte apoptosis. After treatment with tanshinone IIA combined with LPS for 4 weeks, the rats showed better condition than those treated with only LPS. These results indicate that tanshinone IIA attenuates MI and prevents left VR. Importantly, inhibition of TLR4/MyD88/NF‐κB signalling pathway is a key step in this process.

Qiliqiangxin Capsule Improves Cardiac Function and Attenuates Cardiac Remodeling by Upregulating miR-133a after Myocardial Infarction in Rats

“…In addition, the Ginsenoside Rg3, one of the principal constituents in Panax ginseng, could significantly increase the left ventricular fractional shortening and improve the left ventricular ejection fraction in rats [19]. The recent study demonstrated that tanshinone IIA, the main component of salvia miltiorrhiza, increased the ejection fraction and ±dp/dt max in rats with MI [20]. In fact, the cardiac remodeling process induces the abnormal hemodynamics and further stress upon the left ventricular wall, inciting a vicious cycle of stress and remodeling [21].…”

Epigenetic Down-Regulation of Sirt 1 via DNA Methylation and Oxidative Stress Signaling Contributes to the Gestational Diabetes Mellitus-Induced Fetal Programming of Heart Ischemia-Sensitive Phenotype in Late Life

“…At the age of 6 weeks-old, the offspring rats were subjected to induce heart ischemia procedure in vivo as described previously 30. Briefly, rats were anesthetized with isoflurane (5% for induction, 3% for maintenance) (Vet ONE, USA) by inhalation and placed on the RoVent Jr. Small Animal Ventilator (Kent Scientific).…”

Oxidized cholesterol exacerbates toll-like receptor 4 expression and activity in the hearts of rats with myocardial infarction

“…29 Other studies demonstrated that inhibition of TLR4/MyD88/NFκB signaling pathway could improve the severity of MI and prevent cardiac remodeling. 31 We have recently reported that cardiac function in animals fed with high cholesterol and oxidized cholesterol diets before MI induction by isoproterenol considerably suppressed. In summary, our findings improve knowledge about the molecular mechanism of cardiac TLR4 receptors and the implication of dietary OxLDL in inflammatory and immune signaling.…”