Dihydroartemisinin alleviates doxorubicin-induced cardiotoxicity and ferroptosis by activating Nrf2 and regulating autophagy.

Although the use of Doxorubicin (Dox) is extensive in the treatment of malignant tumor, the toxic effects of Dox on the heart can cause myocardial injury. Therefore, it is necessary to find an alternative drug to alleviate the Dox-induced cardiotoxicity. Dihydroartemisinin (DHA) is a semisynthetic derivative of artemisinin, which is an active ingredient of Artemisia annua. The study investigates the effects of DHA on doxorubicin-induced cardiotoxicity and ferroptosis, which are related to the activation of Nrf2 and the regulation of autophagy. Different concentrations of DHA were administered by gavage for 4 weeks in mice. H9c2 cells were pretreated with different concentrations of DHA for 24 h in vitro. The mechanism of DHA treatment was explored through echocardiography, biochemical analysis, real-time quantitative PCR, western blotting analysis, ROS/DHE staining, immunohistochemistry, and immunofluorescence. In vivo, DHA markedly relieved Dox-induced cardiac dysfunction, attenuated oxidative stress, alleviated cardiomyocyte ferroptosis, activated Nrf2, promoted autophagy, and improved the function of lysosomes. In vitro, DHA attenuated oxidative stress and cardiomyocyte ferroptosis, activated Nrf2, promoted clearance of autophagosomes, and reduced lysosomal destruction. The changes of ferroptosis and Nrf2 depend on selective degradation of keap1 and recovery of lysosome. We found for the first time that DHA could protect the heart from the toxic effects of Dox-induced cardiotoxicity. In addition, DHA significantly alleviates Dox-induced ferroptosis through the clearance of autophagosomes, including the selective degradation of keap1 and the recovery of lysosomes.

3,4-benzo[a]pyrene aggravates myocardial infarction injury by activating NLRP3-related pyroptosis through PINK1/Parkin-mitophagy-mPTP opening axis.

BACKGROUND: Air pollution is an important and interventionable risk factor for cardiovascular disease. Air pollution exposure, even for a short-term exposure, is conspicuously relevant to increased risk of myocardial infarction (MI) mortality and clinical evidence has shown that air pollution particulate matter (PM) induces the aggravation of AMI. 3,4-benzo[a]pyrene (BaP), an extremely toxic polycyclic aromatic hydrocarbon (PAH) and a common component of PM, is listed as one of the main objects of environmental pollution monitoring. Both epidemiological and toxicological studies suggest that BaP exposure may be associated with cardiovascular disease. Since PM is significantly associated with the increased risk of MI mortality, and BaP is an important component of PM associated with cardiovascular disease, we intend to investigate the effect of BaP on MI models. METHODS: The MI mouse model and the oxygen and glucose deprivation (OGD) H9C2 cell model were used to investigate the effect of BaP in MI injury. The involvement of mitophagy and pyroptosis in regulating deterioration of cardiac function and aggravation of MI injury induced by BaP was comprehensively evaluated. RESULTS: Our study shows that BaP exacerbates MI injury in vivo and in vitro, a result based on BaP-induced NLRP3-related pyroptosis. In addition, BaP can inhibit PINK1/Parkin dependent mitophagy through the aryl hydrocarbon receptor (AhR), thus the mitochondrial permeability transition pore (mPTP) was induced to open. CONCLUSION: Our results suggest a role for the BaP from air pollution in MI injury aggravation and reveal that BaP aggravates MI injury by activating NLRP3-related pyroptosis via the PINK1/Parkin-mitophagy-mPTP opening axis.