More than a duologue: In-depth insights into epitranscriptomics and ferroptosis

Heat stress induces ferroptosis of porcine Sertoli cells by enhancing CYP2C9-Ras- JNK axis

Heat stress leads to the accumulation of lipid peroxides in Sertoli cells. Unrestricted lipid peroxidation of catalyzed polyunsaturated fatty acids by Cytochrome P450 (CYP) drive the ferroptosis. However, little is known about the role of CYP cyclooxygenase in heat stress-induced ferroptosis in Sertoli cells. In this study, we investigated the relationship between CYP cyclooxygenase and heat stress-induced ferroptosis in porcine Sertoli cells, as well as whether Ras-JNK signaling is involved in the process. The results showed that heat stress significantly increased the expression of cytochrome P450 cyclooxygenase 2C9 (CYP2C9) and the content of epoxyeicosatrienoic acids (EETs), although there are no significant effect on the expression of cytochrome P450 cyclooxygenase 2J2 (CYP2J2) and cytochrome P450 cyclooxygenase 2C8 (CYP2C8). In addition, heat stress reduced the cell viability, the protein expression level of glutathione peroxidase 4 (GPX4) and Ferritin (all P < 0.01) while increased the level of intracellular reactive oxygen species (ROS) and the protein level of Transferrin receptor 1(TFR1) (both P < 0.01), as well as activating the Ras-JNK signaling pathway. Ferrostatin-1, a ferroptosis-specific inhibitor, reduced ROS levels and the protein level of TFR1 (both P < 0.01), but elevated the cell viability, the protein level of GPX4, and Ferritin (all P < 0.01). Sulfaphenazole, a specific inhibitor of CYP2C9 or two small interfering RNAs targaring CYP2C9 enhanced the cell viability (all P < 0.01), while reduced the content of EETs (all P < 0.01) and inhibited the Ras-JNK signaling and ferroptosis under heat stress. Salirasib, a specific inhibitor of Ras, significantly elevated the cell viability, whereas reduced the level of intracellular ROS and inhibited the phosphorylation of JNK, and alleviated heat stress-induced ferroptosis in porcine Sertoli cells. Notably, there is no effect on the expression of CYP2C9 and the content of EETs. These results indicate that heat stress can induce ferroptosis in Sertoli cells by increasing the expression of CYP2C9 and the content of EETs, which in true activates the Ras-JNK signaling pathway, but there is no feedback from Ras-JNK signaling to the expression of CYP2C9. Our study finds a novel heat stress-induced cell death model of Sertoli cells as well as providing the therapeutic potential for anti-ferroptosis.

dECM restores macrophage immune homeostasis and alleviates iron overload to promote DTPI healing

Due to its highly insidious and rapid progression, deep tissue pressure injury (DTPI) is a clinical challenge. Our previous study found that DTPI may be a skeletal muscle injury dominated by macrophage immune dysfunction due to excessive iron accumulation. Decellularized extracellular matrix (dECM) hydrogel promotes skeletal muscle injury repair. However, its role in polarizing macrophages and regulating iron metabolism in DTPI remains unclear. Here, porcine dECM hydrogel was prepared, and its therapeutic function and mechanism in repairing DTPI were investigated. The stimulus of dECM hydrogel toward RAW264.7 cells resulted in a significantly higher percentage of CD206+ macrophages and notably decreased intracellular divalent iron levels. In mice DTPI model, dECM hydrogel treatment promoted M1 to M2 macrophage conversion, improved iron metabolism and reduced oxidative stress in the early stage of DTPI. In the remodeling phase, the dECM hydrogel remarkably enhanced revascularization and accelerated skeletal muscle repair. Furthermore, the immunomodulation of dECM hydrogels in vivo was mainly involved in the P13k/Akt signaling pathway, as revealed by GO and KEGG pathway analysis, which may ameliorate the iron deposition and promote the healing of DTPI. Our findings indicate that dECM hydrogel is promising in skeletal muscle repair, inflammation resolution and tissue injury healing by effectively restoring macrophage immune homeostasis and normalizing iron metabolism.

Ferroptosis: the emerging player in remodeling triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly heterogeneous breast tumor type that is highly malignant, invasive, and highly recurrent. Ferroptosis is a unique mode of programmed cell death (PCD) at the morphological, physiological, and molecular levels, mainly characterized by cell death induced by iron-dependent accumulation of lipid peroxides, which plays a substantial role in a variety of diseases, including tumors and inflammatory diseases. TNBC cells have been reported to display a peculiar equilibrium metabolic profile of iron and glutathione, which may increase the sensitivity of TNBC to ferroptosis. TNBC possesses a higher sensitivity to ferroptosis than other breast cancer types. Ferroptosis also occurred between immune cells and tumor cells, suggesting that regulating ferroptosis may remodel TNBC by modulating the immune response. Many ferroptosis-related genes or molecules have characteristic expression patterns and are expected to be diagnostic targets for TNBC. Besides, therapeutic strategies based on ferroptosis, including the isolation and extraction of natural drugs and the use of ferroptosis inducers, are urgent for TNBC personalized treatment. Thus, this review will explore the contribution of ferroptosis in TNBC progression, diagnosis, and treatment, to provide novel perspectives and therapeutic strategies for TNBC management.

Regulation of m6A modification on ferroptosis and its potential significance in radiosensitization

Radiotherapy is often used to treat various types of cancers, but radioresistance greatly limits the clinical efficiency. Recent studies have shown that radiotherapy can lead to ferroptotic cancer cell deaths. Ferroptosis is a new type of programmed cell death caused by excessive lipid peroxidation. The induction of ferroptosis provides a potential therapeutic strategy for radioresistance. As the most common post-transcriptional modification of mRNA, m6A methylation is widely involved in the regulation of various physiopathological processes by regulating RNA function. Dynamic m6A modification controlled by m6A regulatory factors also affects the susceptibility of cells to ferroptosis, thereby determining the radiosensitivity of tumor cells to radiotherapy. In this review, we summarize the mechanism and significance of radiotherapy induced ferroptosis, analyze the regulatory characteristics of m6A modification on ferroptosis, and discuss the possibility of radiosensitization by enhancing m6A-mediated ferroptosis. Clarifying the regulation of m6A modification on ferroptosis and its significance in the response of tumor cells to radiotherapy will help us identify novel targets to improve the efficacy of radiotherapy and reduce or overcome radioresistance.

Effects of DNA, RNA, and Protein Methylation on the Regulation of Ferroptosis

Ferroptosis is a form of programmed cell death characterized by elevated intracellular ferrous ion levels and increased lipid peroxidation. Since its discovery and characterization in 2012, considerable progress has been made in understanding the regulatory mechanisms and pathophysiological functions of ferroptosis. Recent findings suggest that numerous organ injuries (e.g., ischemia/reperfusion injury) and degenerative pathologies (e.g., aortic dissection and neurodegenerative disease) are driven by ferroptosis. Conversely, insufficient ferroptosis has been linked to tumorigenesis. Furthermore, a recent study revealed the effect of ferroptosis on hematopoietic stem cells under physiological conditions. The regulatory mechanisms of ferroptosis identified to date include mainly iron metabolism, such as iron transport and ferritinophagy, and redox systems, such as glutathione peroxidase 4 (GPX4)-glutathione (GSH), ferroptosis-suppressor-protein 1 (FSP1)-CoQ10, FSP1-vitamin K (VK), dihydroorotate dehydrogenase (DHODH)-CoQ, and GTP cyclohydrolase 1 (GCH1)-tetrahydrobiopterin (BH4). Recently, an increasing number of studies have demonstrated the important regulatory role played by epigenetic mechanisms, especially DNA, RNA, and protein methylation, in ferroptosis. In this review, we provide a critical analysis of the molecular mechanisms and regulatory networks of ferroptosis identified to date, with a focus on the regulatory role of DNA, RNA, and protein methylation. Furthermore, we discuss some debated findings and unanswered questions that should be the foci of future research in this field.