ET-1/NO: a controversial target for myocardial ischemia-reperfusion injury

Molecular mechanisms of endothelial remodeling under doxorubicin treatment

Doxorubicin (DOX) is an effective antineoplastic agent used to treat various types of cancers. However, its use is limited by the development of cardiotoxicity, which may result in heart failure. The exact mechanisms underlying DOX-induced cardiotoxicity are not fully understood, but recent studies have shown that endothelial-mesenchymal transition (EndMT) and endothelial damage play a crucial role in this process. EndMT is a biological process in which endothelial cells lose their characteristics and transform into mesenchymal cells, which have a fibroblast-like phenotype. This process has been shown to contribute to tissue fibrosis and remodeling in various diseases, including cancer and cardiovascular diseases. DOX-induced cardiotoxicity has been demonstrated to increase the expression of EndMT markers, suggesting that EndMT may play a critical role in the development of this condition. Furthermore, DOX-induced cardiotoxicity has been shown to cause endothelial damage, leading to the disruption of the endothelial barrier function and increased vascular permeability. This can result in the leakage of plasma proteins, leading to tissue edema and inflammation. Moreover, DOX can impair the production of nitric oxide, endothelin-1, neuregulin, thrombomodulin, thromboxane B2 etc. by endothelial cells, leading to vasoconstriction, thrombosis and further impairing cardiac function. In this regard, this review is devoted to the generalization and structuring of information about the known molecular mechanisms of endothelial remodeling under the action of DOX.

Shuxuening injection protects against myocardial ischemia-reperfusion injury through reducing oxidative stress, inflammation and thrombosis

Background

Shuxuening injection (SXNI) has a good effect on cardiovascular and cerebrovascular diseases. Here, our study aims to investigate whether SXNI have the protective effect on myocardial ischemia-reperfusion injury (MIRI) and elucidate the mechanism of SXNI's cardiac protection.

Methods

In this experiment, the coronary arteries of Sprague-Dawley (SD) rats were ligated for the induction of a MIRI model. TTC staining and haematoxylin-eosin (HE), as well as troponin I (TnI), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK) and CK-MB levels, were used to detect the protective effect of SXNI. In rat cardiac tissue, superoxide dismutase, catalase, glutathione and malondialdehyde (MDA) activities and glucose-regulated protein 78 (GRP78), calreticulin (CRT), CCAAT/enhancer binding protein homologous protein (CHOP) and caspase-12 expression levels were detected. In rat serum, the levels of inflammatory factors, including high-sensitivity C-reactive protein, monocyte chemoattractant protein-1, tumour necrosis factor-α, interleukin-6 (IL-6) and IL-1β, were measured by Elisa. In the rat arterial tissue, Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) expression was measured by western blot. In the rat plasma, ELISA was used to assay the levels of coagulation and plasmin system indicators, including platelet activating factor, endothelin, tissue factor (TF), plasminogen inhibitor, thromboxane B2, plasma fibrinogen.

Results

The results showed that SXNI can reduce the infarct size of myocardial tissue, decrease the myocardial enzyme and TnI levels and decrease the degree of myocardial damage compared with the model group. Additionally, SXNI can increase the activity of antioxidant enzymes, reduce the MDA level and decrease the GRP78, CRT, CHOP and caspase-12 expression levels. SXNI also decreased the levels of inflammatory cytokines in rat serum, lowered the level of procoagulant molecules in plasma and reduced the TLR4/NF-κB expression.

Conclusions

SXNI has protective effect on MIRI mainly by inhibiting oxidative stress and endoplasmic reticulum stress (ERS), thereby regulating TLR4/NF-κB pathway to reduce inflammation, and lowing procoagulant-related factors levels to reduce the risk of thrombosis.