induction-myocardial-infarction-myocardial-ischemia-reperfusion

Induction of Myocardial Infarction and Myocardial Ischemia-Reperfusion Injury in Mice

Acute myocardial infarction is a common cardiovascular disease with high mortality. Myocardial reperfusion injury can counteract the beneficial effects of ...

Huazhong University of Science and Technology

Thymic stromal lymphopoietin (TSLP) has been shown to be expressed in various inflammatory tissues, such as human atherosclerotic plaques. Many types of myeloid cells involved in atherosclerosis, including mast cells, lymphocytes, dendritic cells and monocytes/macrophages, present TSLP receptors (TSLPR). However, it is unknown whether platelets, which also play important roles in atherothrombosis, express TSLPR.

Human platelets express functional thymic stromal lymphopoietin receptors: a potential role in platelet activation in acute coronary syndrome.

We generated thymic stromal lymphopoietin R-chain deficient apolipoprotein E-double knockout (ApoE-TSLPR DKO) mice to directly explore the role of thymic stromal lymphopoietin (TSLP) in atherogenesis.

TSLPR deficiency attenuates atherosclerotic lesion development associated with the inhibition of TH17 cells and the promotion of regulator T cells in ApoE-deficient mice.

Abnormal expression of thymic stromal lymphopoietin (TSLP) and its receptor (TSLPR) was found in patients with acute coronary syndrome. Ticagrelor, an oral platelet ADP P2Y12 receptor antagonist, is widely used in these patients. The aim of this study was to verify whether different doses of ticagrelor regulated plaque progression and platelet activity by modulating TSLP/TSLPR. Seventy-five ApoE-/- mice were randomly divided into five groups: (1) high-cholesterol diet (HCD, n = 15); (2) HCD plus ticagrelor 25 mg/kg/d (T1, n = 15); (3) HCD plus ticagrelor 50 mg/kg/d (T2, n = 15); (4) HCD plus ticagrelor 100 mg/kg/d (T3, n = 15); and (5) a normal diet group (ND, n = 15). At day 0 and at week 16, blood lipids and serum TSLP levels, expression of TSLPR, CD62, and CD63, platelet aggregation, platelet ATP release, PI3K/Akt signaling pathway, and plaque morphology were assessed. HCD increased TSLPR expression and atherosclerosis progression but high-dose ticagrelor (100 mg/kg) moderated this trend. TSLPR was positively correlated with Akt1, platelet aggregation, corrected plaque area, and vulnerability index in the T3 group (P<0.01). In conclusion, low-dose ticagrelor only inhibited platelet activity. Besides this inhibition, high-dose ticagrelor modulated platelet activity and atherosclerosis mediated by TSLPR, potentially through the PI3K/Akt signal pathway.

A Potential Mechanism of High-Dose Ticagrelor in Modulating Platelet Activity and Atherosclerosis Mediated by Thymic Stromal Lymphopoietin Receptor.

Recently, studies have shown that interleukin-37 (IL-37) is involved in atherosclerosis-related diseases. However, the regulatory mechanisms of IL-37 in atherosclerosis remain unknown. This study aims to determine the role of IL-37 in atherosclerosis and to investigate the underlying mechanisms involved.

Transgenic Overexpression of IL-37 Protects Against Atherosclerosis and Strengthens Plaque Stability.

Regulatory T cells (Tregs) have been shown to attenuate the development and progression of atherosclerosis; however, the exact mechanism is still unclear. In our study, Tregs were adoptively transferred into ApoE mice, and type 2 innate lymphoid cells (ILC2s) were expanded by the IL-2/Jes6-1 complex or depleted by anti-CD90.2 mAb in ApoERag1 mice to study their effects on atherosclerosis. Then, Tregs were cocultured with ILC2s in vitro to analyze ILC2s number and IL-13 production. In vivo, ApoERag1 mice were treated with activated Tregs with or without anti-CD90.2 mAb to explore whether Tregs reduced atherosclerosis through ILC2s. Finally, neutralizing antibodies and Transwell assay were used to investigate how Tregs regulate ILC2s. Our results show that both Tregs and ILC2s reduce atherosclerosis lesions and macrophage infiltration. Moreover, Tregs effectively expanded the number of ILC2s and increased their production of IL-13 in vivo and in vitro. Furthermore, the reductions in plaque size and macrophage infiltration by Tregs were partly reversed by anti-CD90.2 mAb. Mechanistically, our data reveal that IL-10, TGF-β and cell-cell contacts are required for Tregs-ILC2s regulation. These results show that Tregs may play a partial protective role against atherosclerosis by expanding the number of ILC2s and consequently increasing IL-13 production.

Type 2 innate lymphoid cells regulation by regulatory T cells attenuates atherosclerosis.

Bortezomib is a classical proteasome inhibitor and previous researches have reported its roles of anti-oxidation and anti-inflammatory functions in various diseases. However, the role of Bortezomib in myocardial ischemia reperfusion injury (MIRI) is unclear. Thus, our research seeks to reveal the protective effects of Bortezomib pretreatment in the mice model of MIRI. First, by the optimization of Bortezomib concentration and pretreatment timepoints, we found that 0.5 mg/kg Bortezomib pretreatment 2 h before MIRI significantly attenuated pathological damage and neutrophil infiltration. Then we found that pretreatment with Bortezomib obviously increased myocardial systolic function ((left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS)) and decreased infarct size, as well as serum Troponin T levels. Meanwhile, Bortezomib pretreatment also remarkably augmented oxidative stress related protein levels of Superoxide dismutase [Cu-Zn] (SOD1), Catalase (CAT) and Glutathione (GSH), while reactive oxygen species (ROS) contents and Malonaldehyde (MDA) protein level were significantly reduced. Mechanistically, Bortezomib pretreatment significantly promoted nuclear translocation of transcriptional factor nuclear factor erythroid 2-related factor 2(Nrf2) and Heme Oxygenase 1(HO-1) expression. Interestingly, co-treatment with ML-385, a new type and selective Nrf2 inhibitor, counteracted antioxidative effects induced by Bortezomib pretreatment. In conclusion, Bortezomib pretreatment mitigates MIRI by inhibiting oxidative damage which is regulated by Nrf2/HO-1 signaling pathway.

Boyuan Wang

Department of Cardiology,
Union Hospital,
Tongji Medical College,
Department of Cardiology, Union Hospital, Tongji Medical College

Huazhong University of Science and Technology

Induction of Myocardial Infarction and Myocardial Ischemia-Reperfusion Injury in Mice

Boyuan Wang

Department of Cardiology,Union Hospital,Tongji Medical College,Department of Cardiology, Union Hospital, Tongji Medical College

Huazhong University of Science and Technology

Induction of Myocardial Infarction and Myocardial Ischemia-Reperfusion Injury in Mice

Department of Cardiology,
Union Hospital,
Tongji Medical College,
Department of Cardiology, Union Hospital, Tongji Medical College