ETS1 Ameliorates Hyperoxia-Induced Bronchopulmonary Dysplasia in Mice by Activating Nrf2/HO-1 Mediated Ferroptosis

Melatonin Activates KEAP1/NRF2/PTGS2 Pathway to Attenuate Hyperoxia-Driven Ferroptosis in Bronchopulmonary Dysplasia

Background and Purposes

Ferroptosis, a type of regulated cell death, has been confirmed to play a role in the pathogenesis of bronchopulmonary dysplasia (BPD). This study aimed to test the hypothesis that melatonin mitigates hyperoxia-induced BPD by inhibiting ferroptosis in alveolar epithelial cells, specifically through modulation of the KEAP1/NRF2/PTGS2 signaling pathway.

Methods

Hyperoxia-induced MLE-12 cells and neonatal mice were used to establish BPD models. The effects of melatonin on hyperoxia-induced ferroptosis in MLE-12 cells were assessed by administering melatonin and ferroptosis inducer erastin to these cells. Key target genes involved in melatonin's ameliorative effects on BPD were identified using bioinformatics analysis. To confirm the regulatory relationship between melatonin and the KEAP1/NRF2/PTGS2 pathway, MLE-12 cells were treated with the NRF2 inhibitor ML385 under hyperoxic conditions. Additionally, molecular docking was performed to predict interactions between melatonin and KEAP1.

Results

Melatonin (MT) treatment up-regulated the expression of glutathione peroxidase 4 (GPX4) and xCT in hyperoxia-treated alveolar epithelial cells. The anti-ferroptosis effect of MT on these cells was significantly reduced by ML385, confirming the role of the KEAP1/NRF2 pathway in MT's mechanism of action. In vivo experiments demonstrated that MT up-regulated NRF2, GPX4, and xCT levels and down-regulated KEAP1 and PTGS2 levels in hyperoxia-induced BPD models.

Conclusion

Melatonin exerts a protective effect against hyperoxia-induced BPD by inhibiting ferroptosis in alveolar epithelial cells, and this effect is mediated, at least in part, through the KEAP1/NRF2/PTGS2 axis.

ETS1 modulates ferroptosis to affect the process of myocardial ischemia-reperfusion injury via PIM3

Myocardial ischemia-reperfusion injury (MIRI) is a common complication of cardiovascular disease and its pathogenesis remains unclear. ETS1 (E26 transformation-specific sequence-1) is a transcription factor that plays an important regulatory role in vascular development and generation. Therefore, this study aims to explore the role of ETS1 in MIRI and its potential molecular mechanisms. An OGD/R-induced H9C2 cardiomyocyte model was established, and cell viability was determined by CCK8 and changes in SOD, MDA and GSH levels by ELISA; expression of ETS1, PIM3 and ferroptosis-related indices were determined by immunofluorescence, Western blot and qPCR; at the same time, a mouse MIRI model was established to assess changes in myocardial injury and changes in ferroptosis after knockdown of ETS1. In the OGD/R-induced H9C2 cell model, cell viability was significantly lower than that of the control group, and the level of intracellular ferroptosis was significantly enhanced. Further research has revealed that in the OGD/R-induced H9C2 model, the expression of ETS1 is significantly upregulated. Knockdown of ETS1 can reverse the myocardial cell injury induced by OGD/R. Mechanistically, ETS1 promotes the progression of MIRI by targeting and regulating PIM3, thereby exacerbating ferroptosis. Additionally, in a mouse MIRI model, the knockdown of ETS1 significantly enhances the expression of GPX4, SLC7A11, and FTH1 proteins, inhibits the ferroptosis process, and thereby improves MIRI in mice. The research results indicate that ETS1 promotes the MIRI process through regulating ferroptosis of cardiomyocytes mediated by PIM3. This discovery provides important scientific evidence for further elucidating the mechanisms underlying MIRI and developing therapeutic strategies.

Ferroptosis and hyperoxic lung injury: insights into pathophysiology and treatment approaches

Hyperoxia therapy is a critical clinical intervention for both acute and chronic illnesses. However, prolonged exposure to high-concentration oxygen can cause lung injury. The mechanisms of hyperoxic lung injury (HLI) remain incompletely understood, and current treatment options are limited. Improving the safety of hyperoxia therapy has thus become an urgent priority. Ferroptosis, a novel form of regulated cell death characterized by iron accumulation and excessive lipid peroxidation, has been implicated in the pathogenesis of HLI, including diffuse alveolar damage, vascular endothelial injury, and bronchopulmonary dysplasia. In this review, we analyze the latest findings on ferroptosis and therapeutic strategies for HLI. Our aim is to provide new insights for the treatment of HLI and to facilitate the translation of these findings from bench to bedside.

Safety, Efficacy and Bio-Distribution Analysis of Exosomes Derived From Human Umbilical Cord Mesenchymal Stem Cells for Effective Treatment of Bronchopulmonary Dysplasia by Intranasal Administration in Mice Model

Purpose

Exosomes (Exos) derived from human umbilical cord mesenchymal stem cells (hUC-MSCs) hold great potential for treating bronchopulmonary dysplasia (BPD); however, safety concerns and effects of intranasal administration remain unexplored. This study aimed to explore the safety of hUC-MSCs and Exos and to investigate the efficacy and bio-distribution of repeated intranasal Exos administration in neonatal BPD models.

Methods

Characteristics of hUC-MSCs and Exos were analyzed. A subcutaneous tumor formation assay using a single dose of hUC-MSCs or Exos was conducted in Crl:NU-Foxn1nu mice. Vital signs, biochemical indices, pathological alterations, and 18F-FDG microPET/CT analysis were examined. Pulmonary pathology, three-dimensional reconstructions, ultrastructural structures, in vivo and ex vivo bio-distribution imaging analyses, enzyme-linked immunoassay assays, and reverse transcription-quantitative polymerase chain reaction analyses of lung tissues were all documented following intranasal Exos administration.

Results

Characteristics of hUC-MSCs and Exos satisfied specifications. Crl:NU-Foxn1nu mice did not exhibit overt toxicity or carcinogenicity following a single dose of hUC-MSCs or Exos after 60 days of observation. Repeated intranasal Exos administration effectively alleviated pathological injuries, restored pulmonary ventilation in three-dimensional reconstruction, and recovered endothelial cell layer integrity in ultrastructural analysis. Exos steadily accumulated in lung tissues from postnatal day 1 to 14. Exos also interrupted the epithelial-mesenchymal transition and inflammation reactions in BPD models.

Conclusion

As a nanoscale, non-cellular therapy, intranasal administration of Exos was an effective, noninvasive treatment for BPD. This approach was free from toxic, tumorigenic risks and repaired alveolar damage while interrupting epithelial-mesenchymal transition and inflammation in neonatal mice with BPD.

Effects of PGE1 on the ERS pathway in neonatal rats with hyperoxic lung injury

BACKGROUND

With the increase in the number of low birth weight infants, oxygen therapy is more widely used. However, chronic high-concentration oxygen environments lead to hyperoxic lung injury in children, which in turn leads to bronchopulmonary dysplasia (BPD). PGE1 is widely used in the clinic for its ability to inhibit inflammation and improve circulation. Therefore, we further investigated whether PGE-1 has a therapeutic effect on hyperoxic lung injury.

METHODS

Hyperoxic lung injury model was adopted for investigating the interventional effects and underlying mechanisms of intraperitoneal injection of prostaglandin E1 (PGE-1) on hyperoxic lung injury in newborn rats via relevant experimental techniques, such as Diff-Quick staining, lung wet dry specific gravity measurements, HE staining, TUNEL staining, ELISA, and the Western blot method.

RESULTS

Inflammatory and apoptotic cells in the PGE1-treated group were significantly lower than those in the hyperoxic lung injury group (p < 0.05); and the contents of IL-1β, IL-6 and TNF-α in the treated group were significantly lower than those in the model group (p < 0.05). Caspase-3, CHOP, GRP78 and Bcl-2/Bax protein expression in the treatment group was significantly lower than that in the model group (p < 0.05).

CONCLUSION

PGE-1 has a therapeutic effect on hyperoxic lung injury in neonatal rats.

IMPACT

PGE1 treatment reduces levels of inflammatory cells and pro-inflammatory cytokines and decreases apoptosis. PGE1 has a therapeutic effect on BPD through the endoplasmic reticulum stress pathway. This study offers the possibility of PGE1 for the treatment of BPD.

A novel dual fixation method for improving the reliable assessment of pulmonary vascular morphology in pulmonary hypertension rats

This study introduced a novel dual fixation method for the pulmonary vasculature and lung tissue in pulmonary hypertension (PH) rats, addressing the limitations of traditional fixation methods that failed to accurately preserve the in vivo status of pulmonary vascular morphology. The modified method involved a dual fixation process, combining individualized ventilation support and vascular perfusion to simulate the respiratory motion, pulmonary artery pressure and right ventricular output of the rat under in vivo conditions. Utilizing a monocrotaline-induced PH rat model, this study compared the dual fixation with the traditional immersion fixation, focusing on the quantitative assessment of alveolar expansion degree, capillary patency, endothelial cell quantity and wall thickness of pulmonary vein and artery. The results demonstrated that the dual fixation is superior in maintaining the authenticity and integrity of lung tissue and more sensitive in the evaluation of pulmonary artery hypertrophy, providing a more reliable representation of pulmonary vascular remodeling associated with PH.

Pedunculoside inhibits cardiomyocyte inflammatory biomarkers via Nrf2/HO-1 pathway in high glucose-induced H9c2 cells and diabetic cardiomyopathy model rats

IntroductionDiabetic cardiomyopathy (DCM) is a complication of diabetes mellitus (DM) that can lead to heart failure and increase the risk of mortality. Pedunculoside (PE), a novel triterpenoid saponin, exhibits anti-inflammatory and anti-oxidative stress (OS) properties. However, its role in DCM remains unexplored.MethodsDCM models were established and treated with PE or the Nrf2 inhibitor (ML385). In vitro, cell function was evaluated using CCK-8, flow cytometry, qRT-PCR, and ELISA. In vivo, fasting blood glucose and insulin levels in rats were measured. The effects of PE on DCM were assessed using HE staining, TUNEL staining, and corresponding kits. Additionally, Nrf2/HO-1 pathway proteins were analyzed by western blot.ResultsLow doses of PE (2.5, 5, 10, and 20 μM) did not affect the viability of H9c2 cells. PE (10 and 20 μM) improved cell viability and prevented apoptosis, inflammation, and OS in high glucose (HG)-stimulated H9c2 cells. PE also upregulated Nrf2 in the nucleus and enhanced HO-1 and NQO1 expression in HG-treated H9c2 cells. Furthermore, the Nrf2 inhibitor (ML385) reversed PE's protective effects on HG-induced cell injury. In vivo, PE reduced blood glucose, increased insulin, alleviated myocardial injury, inhibited apoptosis, decreased levels of inflammatory factors and OS, and upregulated Nrf2, HO-1, and NQO1 in DCM model rats.DiscussionPE alleviates DCM injury by activating the Nrf2/HO-1 pathway. These findings support the potential therapeutic application of PE in DCM.

Circ-ECH1 May Compete With miR-708-5p to Regulate Ntrk2 in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) affects patients' quality of life. Circular RNAs participated in BPD. However, circ-ECH1's role in BPD has not been reported yet. This study aimed to explore the role and mechanism of circ-ECH1 in BPD. Hyperoxia-treated type II alveolar epithelial cells (L2 cells) were used as the in vitro BPD model. CCK-8, flow cytometry, and reactive oxygen species (ROS) were used to evaluate cell viability. Fluorescence in situ hybridization confirmed the subcellular localization. Circ-ECH1 overexpression (or inhibited) and miR-708-5p mimics were used to investigate the roles of circ-ECH1 and miR-708-5p in BPD. Quantitative reverse-transcription polymerase reaction (qRT-PCR) detected the expressions of circ-ECH1, miR-708-5p, and neurotrophic receptor tyrosine kinase 2 (Ntrk2). Ntrk2 expression was evaluated by Western blot analysis. Changes in lung tissues were evaluated by hematoxylin and eosin staining. Pulmonary fibrosis was examined by Mason staining. TUNEL staining was performed to evaluate cell apoptosis in lung tissues. RNA sequencing was performed in the lung tissues of BPD rats. The binding between circ-ECH1 and miR-708-5p was confirmed through dual luciferase activity. Hyperoxia reduced cell viability and increased cell apoptosis and ROS accumulation. In addition, hyperoxia decreased the expression levels of circ-ECH1, which is mainly located in the cytoplasm. Circ-ECH1 overexpression increased cell viability but reduced cell apoptosis and ROS accumulation. On the contrary, interference with circ-ECH1 further promoted cell apoptosis and reduced cell activity. Furthermore, circ-ECH1 overexpression reduced the incidence of pulmonary fibrosis and lung cell apoptosis. RNA sequencing, followed by qRT-PCR, confirmed that the expressions of Ntrk2 and miR-708-5p were affected by circ-ECH1. miR-708-5p mimics reversed the role of circ-ECH1 in the BPD. Mechanistically, circ-ECH1 may bind with miR-708-5p to regulate Ntrk2 expression. Circ-ECH1 may compet with miR-708-5p to regulate Ntrk2 expression in BPD. The findings provided a new target for BPD treatment.

Hyperoxia exposure induces ferroptosis and apoptosis by downregulating PLAGL2 and repressing HIF-1α/VEGF signaling pathway in newborn alveolar typeII epithelial cell

BACKGROUD

Bronchopulmonary dysplasia (BPD) is one of the most important complications plaguing neonates and can lead to a variety of sequelae. the ability of the HIF-1α/VEGF signaling pathway to promote angiogenesis has an important role in neonatal lung development.

METHOD

Newborn rats were exposed to 85% oxygen. The effects of hyperoxia exposure on Pleomorphic Adenoma Gene like-2 (PLAGL2) and the HIF-1α/VEGF pathway in rats lung tissue were assessed through immunofluorescence and Western Blot analysis. In cell experiments, PLAGL2 was upregulated, and the effects of hyperoxia and PLAGL2 on cell viability were evaluated using scratch assays, CCK-8 assays, and EDU staining. The role of upregulated PLAGL2 in the HIF-1α/VEGF pathway was determined by Western Blot and RT-PCR. Apoptosis and ferroptosis effects were determined through flow cytometry and viability assays.

RESULTS

Compared with the control group, the expression levels of PLAGL2, HIF-1α, VEGF, and SPC in lung tissues after 3, 7, and 14 days of hyperoxia exposure were all decreased. Furthermore, hyperoxia also inhibited the proliferation and motility of type II alveolar epithelial cells (AECII) and induced apoptosis in AECII. Upregulation of PLAGL2 restored the proliferation and motility of AECII and suppressed cell apoptosis and ferroptosis, while the HIF-1α/VEGF signaling pathway was also revived.

CONCLUSIONS

We confirmed the positive role of PLAGL2 and HIF-1α/VEGF signaling pathway in promoting BPD in hyperoxia conditions, and provided a promising therapeutic targets.

CHAC1: a master regulator of oxidative stress and ferroptosis in human diseases and cancers

CHAC1, an essential regulator of oxidative stress and ferroptosis, is increasingly recognized for its significant roles in these cellular processes and its impact on various human diseases and cancers. This review aims to provide a comprehensive overview of CHAC1's molecular functions, regulatory mechanisms, and effects in different pathological contexts. Specifically, the study objectives are to elucidate the biochemical pathways involving CHAC1, explore its regulatory network, and discuss its implications in disease progression and potential therapeutic strategies. As a γ-glutamyl cyclotransferase, CHAC1 degrades glutathione, affecting calcium signaling and mitochondrial function. Its regulation involves transcription factors like ATF4 and ATF3, which control CHAC1 mRNA expression. CHAC1 is crucial for maintaining redox balance and regulating cell death pathways in cancer. Its elevated levels are associated with poor prognosis in many cancers, indicating its potential as a biomarker and therapeutic target. Additionally, CHAC1 influences non-cancerous diseases such as neurodegenerative and cardiovascular disorders. Therapeutically, targeting CHAC1 could increase cancer cell sensitivity to ferroptosis, aiding in overcoming resistance to standard treatments. This review compiles current knowledge and recent discoveries, emphasizing CHAC1's vital role in human diseases and its potential in diagnostic and therapeutic applications.

Calcitonin gene‑related peptide alleviates hyperoxia‑induced human alveolar cell injury via the CGRPR/TRPV1/Ca2+ axis

Although exogenous calcitonin gene‑related peptide (CGRP) protects against hyperoxia‑induced lung injury (HILI), the underlying mechanisms remain unclear. The present study attempted to elucidate the molecular mechanism by which CGRP protects against hyperoxia‑induced alveolar cell injury. Human alveolar A549 cells were treated with 95% hyperoxia to establish a hyperoxic cell injury model. ELISA was performed to detect the CGRP secretion. Immunofluorescence, quantitative (q)PCR, and western blotting were used to detect the expression and localization of CGRP receptor (CGRPR) and transient receptor potential vanilloid 1 (TRPV1). Cell counting kit‑8 and flow cytometry were used to examine the proliferation and apoptosis of treated cells. Digital calcium imaging and patch clamp were used to analyze the changes in intracellular Ca2+ signaling and membrane currents induced by CGRP in A549 cells. The mRNA and protein expression levels of Cyclin D1, proliferating cell nuclear antigen (PCNA), Bcl‑2 and Bax were detected by qPCR and western blotting. The expression levels of CGRPR and TRPV1 in A549 cells were significantly downregulated by hyperoxic treatment, but there was no significant difference in CGRP release between cells cultured under normal air and hyperoxic conditions. CGRP promoted cell proliferation and inhibited apoptosis in hyperoxia, but selective inhibitors of CGRPR and TRPV1 channels could effectively attenuate these effects; TRPV1 knockdown also attenuated this effect. CGRP induced Ca2+ entry via the TRPV1 channels and enhanced the membrane non‑selective currents through TRPV1 channels. The CGRP‑induced increase in intracellular Ca2+ was reduced by inhibiting the phospholipase C (PLC)/protein kinase C (PKC) pathway. Moreover, PLC and PKC inhibitors attenuated the effects of CGRP in promoting cell proliferation and inhibiting apoptosis. In conclusion, exogenous CGRP acted by inversely regulating the function of TRPV1 channels in alveolar cells. Importantly, CGRP protected alveolar cells from hyperoxia‑induced injury via the CGRPR/TRPV1/Ca2+ axis, which may be a potential target for the prevention and treatment of the HILI.

Identification of ferroptosis-related genes in acute phase of temporal lobe epilepsy based on bioinformatic analysis

BACKGROUND

Epilepsy is a prevalent neurological disorder, and while its precise mechanism remains elusive, a connection to ferroptosis has been established. This study investigates the potential clinical diagnostic significance of ferroptosis-related genes (FRGs) during the acute phase of temporal lobe epilepsy.

METHODS

To identify differentially expressed genes (DEGs), we accessed data from the GEO database and performed an intersection analysis with the FerrDB database to pinpoint FRGs. A protein-protein interaction (PPI) network was constructed. To assess the diagnostic utility of the discovered feature genes for the disease, ROC curve analysis was conducted. Subsequently, qRT-PCR was employed to validate the expression levels of these feature genes.

RESULTS

This study identified a total of 25 FRGs. PPI network analysis revealed six feature genes: IL6, PTGS2, HMOX1, NFE2L2, TLR4, and JUN. ROC curve analysis demonstrated that the combination of these six feature genes exhibited the highest diagnostic potential. qRT-PCR validation confirmed the expression of these feature genes.

CONCLUSION

We have identified six feature genes (IL6, PTGS2, HMOX1, NFE2L2, TLR4, and JUN) strongly associated with ferroptosis in epilepsy, suggesting their potential as biomarkers for the diagnosis of temporal lobe epilepsy.