Background and aims The anthracycline chemotherapeutic agent doxorubicin (DOX) is widely used to treat cancer. However, DOX carries a high risk of adverse effects such as cardiovascular events. The aim of this study was to explore the role of Trim65 in DOX-induced cardiotoxicity (DIC) and its underlying mechanisms. Methods and Results Cellular studies were performed by exposing H9c2 cells (rat cardiomyocytes) to DOX. H9c2 cells were infected with lentivirus encoding negative control (LV-NC) or Trim65 (LV-Trim65). C57BL/6J mice were exposed to adeno-associated virus 9 (AAV9) containing cTnT promoter-encoded Trim65 sequence (AAV-Trim65) or AAV9 negative control sequence (AAV-NC) via tail vein injection. Furthermore, the following analysis were performed: cell viability, intracellular ROS production and lipid peroxidation. Echocardiography was used to measure the heart function of the mice. qPCR and western blotting were used to assess the expression of Trim65, p53, SLC7A11, and GPX4. According to our study, Trim65 expression was significantly downregulated in DIC. Overexpression of Trim65 exhibited considerable protection against to DIC, confirmed by both in vitro and in vivo experiments. In DOX-treated mice, mitochondria deformation was observed in the heart, as well as a high level of lipid peroxidation (signs of ferroptosis) and iron content, which were mitigated by overexpression of Trim65. Mechanistically, our study confirmed that DOX reduced the Trim65-mediated ubiquitination of p53, ultimately inhibiting the degration of p53. We also found that Trim65 mitigated DOX-induced ferroptosis via p53. Conclusion Collectively, our data demonstrated that Trim65 inhibits ferroptosis by degrading p53, thereby alleviating DIC. Therefore, Trim65 could be a promising target for the treatment of DIC.
BackgroundEndometriosis (EM) is a benign gynecological disease that shares some characteristics with malignancy, such as proliferation and invasion. So far, the pathogenesis of EM is still unclear. In this study, we investigated whether TRIM65 can play a role in the development of EM.MethodsTRIM65 expression levels in eutopic, ectopic, and normal endometrium were detected by quantitative real-time PCR and Western blot. Cell proliferation and invasion of primary endometrial stromal (EMS) cells were detected by CCK-8 and Transwell analysis. The interaction between TRIM65 and DUSP6 or C-myc was measured by coimmunoprecipitation, ubiquitylation, dual luciferase, and chromatin immunoprecipitation analysis.ResultsWe found that TRIM65 was identified as an up-regulated gene in ectopic endometrial tissues and EMS cells compared with control groups without EM. TRIM65 expression was positively correlated with the levels of p-ERK1/2, C-myc, matrix metalloproteinase-2, and integrin β1 in ectopic endometrial tissues in patients and mice. TRIM65 promoted the cell proliferation and invasion of EMS cells via the ERK1/2/C-myc pathway through ubiquitination of DUSP6. C-myc promoted TRIM65 expression through inducing TRIM65 promoter activity. Additionally, the increased expression of TRIM65, C-myc, matrix metalloproteinase-2, integrin β1, and p-ERK1/2 and the decreased expression of DUSP6 in ectopic endometrial tissues were significantly suppressed by inhibition of ERK1/2 signaling pathway in ectopic endometrial tissues in experimental mice model.ConclusionIn conclusion, TRIM65 promotes invasion of ectopic EMS cells by activating a feedback loop with the ERK1/2/C-myc signaling pathway and may be a potential therapeutic target for EM.