The Emerging Roles of Ferroptosis in Pathophysiology and Treatment of Acute Lung Injury

Huperzine A protected against ferroptosis via activating PI3K/Akt signaling in lipopolysaccharide induced acute lung injury

Huperzine A (Hup A), an extract from Huperzia serrata, exerted its anti-inflammation and anti-oxidation effect to protect against neurodegenerative disorders and organ injury. Ferroptosis was indicated to involve in the development of acute lung injury (ALI) accompanying by lipid reactive oxygen species (ROS) overexpressed. However, there is little research focused on the protective effect of Hup A on ALI, and the underlying molecular mechanism remains elusive. This study aims to determine the therapeutic effect of Hup A on ALI in vivo and in vitro. Hup A attenuated lung injury and cellular damage in lipopolysaccharide-induced ALI (LPS-ALI) models, both in vivo and in vitro, accompanied by the upregulation of ferroptosis-associated proteins (SLC7A11 and GPX4). Furthermore, the pretreatment with Hup A decreased the abundance of inflammation factors (IL-6, TNF-α), MDA, lipid ROS, and Fe2+ in the LPS-ALI model, while it also promoted the secretion of SOD and GSH to antagonize peroxidation. Mechanistically, RNA sequencing and network pharmacological analysis synergistically revealed the PI3K/Akt signaling pathway as a potential target of Hup A. In vitro experiments demonstrated that Hup A effectively activated GPX4 through the PI3K/Akt signaling pathway, which was subsequently reversed by LY294002, an inhibitor of the PI3K/Akt signaling pathway. Consequently, our results revealed that Hup A inhibited ferroptosis in LPS-ALI by activating the PI3K-Akt signaling pathway which indicated the potential therapeutical effect of Hup A and further emphasized the pivotal role of ferroptosis in ALI.

Mitophagy and Ferroptosis in Sepsis-Induced ALI/ARDS: Molecular Mechanisms, Interactions and Therapeutic Prospects of Medicinal Plants

Sepsis is a common critical illness characterized by high mortality rates and a significant disease burden. In the context of sepsis-induced organ dysfunction, the lungs are among the initial organs affected, which may progress to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Recent studies have highlighted the crucial roles of mitophagy and ferroptosis in the development and progression of sepsis-induced ALI/ARDS. Identifying key convergence points in these processes may provide valuable insights for the treatment of this condition. In recent years, certain herbs and their bioactive compounds have demonstrated unique benefits in managing sepsis-induced ALI/ARDS by modulating mitophagy or ferroptosis. This review summary the mechanisms of mitophagy and ferroptosis, explores their interactions, and emphasizes their regulatory roles in the progression of sepsis-induced ALI/ARDS. Additionally, it offers a novel perspective on treatment strategies by summarizing various herbs and their bioactive compounds relevant to this condition.

The VDR/FFAR2 axis mitigates sepsis-induced lung injury by suppressing macrophage lipid peroxidation

Sepsis-induced lung injury is a common critical condition in clinical practice, characterized by the accumulation of peroxides and inflammatory damage caused by excessive macrophage activation. Currently, effective treatments for sepsis-induced lung injury are lacking. Short-chain fatty acid receptor FFAR2 serves as an anti-inflammatory biomarker, but its role and mechanism in sepsis-induced lung injury remain unclear. To elucidate the influence and mechanism of FFAR2 on macrophage lipid peroxidation levels in sepsis-induced lung injury, this study conducted bioinformatics analysis and cellular experiments using the THP-1 macrophage cell line. By dual luciferase reporter and chromatin immunoprecipitation-quantitative PCR assays, it is confirmed that the transcription factor VDR upregulates FFAR2 expression in macrophages by binding to the promoter region -1695 ∼ 1525, thereby increasing the expression of iron death negative regulatory molecules and lowering macrophage lipid peroxidation levels. Moreover, both in vitro using THP-1 cells and bone marrow-derived macrophages (BMDMs) and in vivo using an LPS-induced septic mice model experiments revealed that activating the VDR/FFAR2 axis could reduce inflammation-induced macrophage lipid peroxide accumulation and alleviate lung injury in septic mice. This finding highlights the potential of FFAR2 as an immunotherapeutic target for mitigating sepsis-related lung injury.

Ferroptosis and myocardial ischemia-reperfusion: mechanistic insights and new therapeutic perspectives

Myocardial ischemia-reperfusion injury (MIRI) is a significant factor in the development of cardiac dysfunction following a myocardial infarction. Ferroptosis, a type of regulated cell death driven by iron and marked by lipid peroxidation, has garnered growing interest for its crucial involvement in the pathogenesis of MIRI.This review comprehensively examines the mechanisms of ferroptosis, focusing on its regulation through iron metabolism, lipid peroxidation, VDAC signaling, and antioxidant system dysregulation. We also compare ferroptosis with other forms of cell death to highlight its distinct characteristics. Furthermore, the involvement of ferroptosis in MIRI is examined with a focus on recent discoveries concerning ROS generation, mitochondrial impairment, autophagic processes, ER stress, and non-coding RNA regulation. Lastly, emerging therapeutic strategies that inhibit ferroptosis to mitigate MIRI are reviewed, providing new insights into potential clinical applications.

GDF11 OVEREXPRESSION ALLEVIATES SEPSIS-INDUCED LUNG MICROVASCULAR ENDOTHELIAL BARRIER DAMAGE BY ACTIVATING SIRT1/NOX4 SIGNALING TO INHIBIT FERROPTOSIS

ABSTRACT

Sepsis is a lethal clinical syndrome, and acute lung injury (ALI) is the earliest and most serious complication. We aimed to explore the role of growth differentiation factor 11 (GDF11) in sepsis-induced dysfunction of lung microvascular endothelial barrier in vivo and in vitro to elucidate its potential mechanism related to sirtuin 1 (SIRT1)/NADPH oxidase 4 (NOX4) signaling. Cecal ligation and puncture (CLP)-induced sepsis mice and lipopolysaccharide (LPS)-induced pulmonary microvascular endothelial cells (PMECs) were used in this study. Histopathological changes in lung tissues were tested by hematoxylin-eosin staining. Lung wet-to-dry weight ratio and inflammatory factors contents in bronchoalveolar lavage fluid were assessed. Evens blue index, trans-epithelial electrical resistance, and expression of zona occludens 1 (ZO-1), occludin-1, and claudin-1 were used to evaluate alveolar barrier integrity. Reactive oxygen species, lipid peroxidation, and ferroptosis markers were analyzed. Iron deposition in the lung tissues was assessed using Prussian blue staining. Intracellular Fe 2+ level was detected using FerroOrange staining. Additionally, expression of GDF11, SIRT1, and NOX4 was estimated with western blot. Then, EX527, a SIRT1 inhibitor, was employed to treat GDF11-overexpressed PMECs with LPS stimulation to clarify the regulatory mechanism. Results showed that GDF11 overexpression attenuated sepsis-induced pathological changes and inflammation and maintained alveolar barrier integrity. Moreover, GDF11 overexpression inhibited ferroptosis, upregulated SIRT1 expression and downregulated NOX4 expression. Additionally, EX527 treatment relieved the impacts of GDF11 overexpression on ferroptosis and destruction of integrity of human pulmonary microvascular endothelial cells exposed to LPS. Taken together, GDF11 overexpression could alleviate sepsis-induced lung microvascular endothelial barrier damage by activating SIRT1/NOX4 signaling to inhibit ferroptosis. Our findings potentially provide new molecular target for clinical therapy of ALI.

3-methyladenine ameliorates acute lung injury by inhibiting oxidative damage and apoptosis

Background

Acute lung injury (ALI) is a condition characterized by inflammation and oxidative damage. 3-methyladenine (3-MA) has great potential for regulating apoptosis, but its regulatory role in ALI is unknown.

Methods

Lipopolysaccharide (LPS)-treated mice and tert-butyl hydroperoxide (TBHP)-treated bronchial epithelial cells were used to simulate in vivo and in vitro ALI models, respectively. In vivo, lung injury was assessed by histopathological analysis and lung injury scoring. The total cell count, protein content, and inflammatory factors in bronchoalveolar lavage fluid (BALF) were examined. The level of apoptosis in lung tissue was assessed through TUNEL staining. In the vitro ALI model, cell viability and levels of reactive oxygen species and apoptosis were assessed.

Results

3-MA pretreatment ameliorated lung injury, including intra-alveolar hemorrhage and inflammatory cell accumulation, both in vitro and in vivo. 3-MA pretreatment also decreased inflammatory factor levels in the BALF. 3-MA pretreatment alleviated oxidative damage, decreased reactive oxygen species levels, and attenuated morphological changes. TUNEL and Annexin V-FITC/PI staining revealed that pretreatment with 3-MA reduced the level of apoptosis. 3-MA pretreatment significantly decreased the expression of caspase-3 and Bax but increased the expression of Bcl-2 in ALI. Mechanistically, 3-MA pretreatment also affected the PKCα/NOX4 and Nrf2 pathways, which decreased the level of apoptosis in ALI.

Conclusions

3-MA pretreatment inhibited inflammation and oxidative damage in ALI and inhibited apoptosis to mitigate ALI in part by inhibiting the PKCα/NOX4 pathway and activating the Nrf2 pathway. Based on these results, 3-MA might be a viable medication to treat with ALI.

Acute lung injury: a view from the perspective of necroptosis

BACKGROUND

ALI/ARDS is a syndrome of acute onset characterized by progressive hypoxemia and noncardiogenic pulmonary edema as the primary clinical manifestations. Necroptosis is a form of programmed cell necrosis that is precisely regulated by molecular signals. This process is characterized by organelle swelling and membrane rupture, is highly immunogenic, involves extensive crosstalk with various cellular stress mechanisms, and is significantly implicated in the onset and progression of ALI/ARDS.

METHODS

The current body of literature on necroptosis and ALI/ARDS was thoroughly reviewed. Initially, an overview of the molecular mechanism of necroptosis was provided, followed by an examination of its interactions with apoptosis, pyroptosis, autophagy, ferroptosis, PANOptosis, and NETosis. Subsequently, the involvement of necroptosis in various stages of ALI/ARDS progression was delineated. Lastly, drugs targeting necroptosis, biomarkers, and current obstacles were presented.

CONCLUSION

Necroptosis plays an important role in the progression of ALI/ARDS. However, since ALI/ARDS is a clinical syndrome caused by a variety of mechanisms, we emphasize that while focusing on necroptosis, it may be more beneficial to treat ALI/ARDS by collaborating with other mechanisms.

Monochasma savatieri Franch. protects against acute lung injury via α7nAChR-TLR4/NF-κB p65 signaling pathway based on integrated pharmacology analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) is a life-threatening condition with high morbidity and mortality, underscoring the urgent need for novel treatments. Monochasma savatieri Franch. (LRC) is commonly used clinically to treat wind-heat cold, bronchitis, acute pneumonia and acute gastroenteritis. However, its role in the treatment of ALI and its mechanism of action are still unclear.

AIM OF THE STUDY

This study aimed to demonstrate the pharmacological effects and underlying mechanisms of LRC extract, and provide important therapeutic strategies and theoretical basis for ALI.

MATERIALS AND METHODS

In this study, a research paradigm of integrated pharmacology combining histopathological analysis, network pharmacology, metabolomics, and biochemical assays was used to elucidate the mechanisms underlaying the effects of LRC extract on LPS-induced ALI in BALB/c mice.

RESULTS

The research findings demonstrated that LRC extract significantly alleviated pathological damage in lung tissues and inhibited apoptosis in alveolar epithelial cells, and the main active components were luteolin, isoacteoside, and aucubin. Lung tissue metabolomic and immunohistochemical methods confirmed that LRC extract could restore metabolic disorders in ALI mice by correcting energy metabolism imbalance, activating cholinergic anti-inflammatory pathway (CAP), and inhibiting TLR4/NF-κB signaling pathway.

CONCLUSIONS

This study showed that LRC extract inhibited the occurrence and development of ALI inflammation by promoting the synthesis of antioxidant metabolites, balancing energy metabolism, activating CAP and suppressing the α7nAChR-TLR4/NF-κB p65 signaling pathway. In addition, our study provided an innovative research model for exploring the effective ingredients and mechanisms of traditional Chinese medicine. To the best of our knowledge, this is the first report describing the protective effects of LRC extract in LPS-induced ALI mice.

Identification of cuproptosis-related gene clusters and immune cell infiltration in major burns based on machine learning models and experimental validation

Introduction

Burns are a global public health problem. Major burns can stimulate the body to enter a stress state, thereby increasing the risk of infection and adversely affecting the patient's prognosis. Recently, it has been discovered that cuproptosis, a form of cell death, is associated with various diseases. Our research aims to explore the molecular clusters associated with cuproptosis in major burns and construct predictive models.

Methods

We analyzed the expression and immune infiltration characteristics of cuproptosis-related factors in major burn based on the GSE37069 dataset. Using 553 samples from major burn patients, we explored the molecular clusters based on cuproptosis-related genes and their associated immune cell infiltrates. The WGCNA was utilized to identify cluster-specific genes. Subsequently, the performance of different machine learning models was compared to select the optimal model. The effectiveness of the predictive model was validated using Nomogram, calibration curves, decision curves, and an external dataset. Finally, five core genes related to cuproptosis and major burn have been was validated using RT-qPCR.

Results

In both major burn and normal samples, we determined the cuproptosis-related genes associated with major burns through WGCNA analysis. Through immune infiltrate profiling analysis, we found significant immune differences between different clusters. When K=2, the clustering number is the most stable. GSVA analysis shows that specific genes in cluster 2 are closely associated with various functions. After identifying the cross-core genes, machine learning models indicate that generalized linear models have better accuracy. Ultimately, a generalized linear model for five highly correlated genes was constructed, and validation with an external dataset showed an AUC of 0.982. The accuracy of the model was further verified through calibration curves, decision curves, and modal graphs. Further analysis of clinical relevance revealed that these correlated genes were closely related to time of injury.

Conclusion

This study has revealed the intricate relationship between cuproptosis and major burns. Research has identified 15 cuproptosis-related genes that are associated with major burn. Through a machine learning model, five core genes related to cuproptosis and major burn have been selected and validated.