Ficolin B secreted by alveolar macrophage exosomes exacerbates bleomycin-induced lung injury via ferroptosis through the cGAS-STING signaling pathway

Calpain-1 Up-Regulation Promotes Bleomycin-Induced Pulmonary Fibrosis by Activating Ferroptosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal disease. Calpain-1 was shown to be an effective therapeutic target for vascular endothelial dysfunction and pulmonary hypertension. However, the role of calpain-1 in bleomycin (BLM)-induced IPF has not been defined. The aim of this study was to assess the targeting of calpain-1 by activating ferroptosis in BLM-treated knockout mice and murine lung epithelial-12 cells. In this study, the role of calpain-1 in the regulation of IPF was investigated using a BLM-induced IPF mouse model. The results of our study showed that increased expression of calpain-1 was accompanied by increased fibrosis, lipid peroxidation, iron ion accumulation, and YAP levels and decreased levels of p-AMPK in BLM-induced IPF. MDL-28170 (calpain-1 inhibition) treatment and calpain-1 knockdown alleviated ferroptosis and IPF induced by BLM. Overexpression of calpain-1 in murine lung epithelial-12 cells further exacerbated iron accumulation and IPF. Mechanistically, lentivirus-mediated up-regulation of calpain-1 inhibited AMPK activity and promoted the nuclear translocation of YAP, leading to high levels of acyl-CoA synthetase long-chain family 4 -and transferrin receptor protein 1 and triggering a ferroptosis response that ultimately exacerbated BLM-induced lung fibrosis. Calpain-1 inhibition reversed these results and ameliorated BLM-induced IPF. In conclusion, these findings suggest that the calpain-1-acyl-CoA synthetase long-chain family 4-transferrin receptor protein 1-ferroptosis-positive regulatory axis contributes to BLM-induced IPF, which indicates that calpain-1 has potential therapeutic value for the treatment of IPF.

Interaction between macrophages and ferroptosis: Metabolism, function, and diseases

ABSTRACT

Ferroptosis, an iron-dependent programmed cell death process driven by reactive oxygen species-mediated lipid peroxidation, is regulated by several metabolic processes, including iron metabolism, lipid metabolism, and redox system. Macrophages are a group of innate immune cells that are widely distributed throughout the body, and play pivotal roles in maintaining metabolic balance by its phagocytic and efferocytotic effects. There is a profound association between the biological functions of macrophage and ferroptosis. Therefore, this review aims to elucidate three key aspects of the unique relationship between macrophages and ferroptosis, including macrophage metabolism and their regulation of cellular ferroptosis; ferroptotic stress that modulates functions of macrophage and promotion of inflammation; and the effects of macrophage ferroptosis and its role in diseases. Finally, we also summarize the possible mechanisms of macrophages in regulating the ferroptosis process at the global and local levels, as well as the role of ferroptosis in the macrophage-mediated inflammatory process, to provide new therapeutic insights for a variety of diseases.

The Role of Ficolins in Lung Injury

BACKGROUND

Respiratory diseases seriously threaten human health worldwide, and lung injury is an important component of respiratory disease. Complement activation is an important function of the innate immune system. Complement activation helps the body defend against invasion by external microorganisms, whereas excessive complement activation can exacerbate tissue damage or lead to unwanted side effects. Ficolins are a class of immune-related proteins in the lectin pathway that play important roles in the body's immune defense. Although individual ficolins are not well understood, current information suggests that ficolins may play an important regulatory role in lung injury.

SUMMARY

Several studies have shown that ficolins are involved in the immune response in the lung, particularly in the response to infectious and inflammatory processes.

KEY MESSAGES

This review summarizes the role of ficolins in lung injury. Ficolins may influence the development and repair of lung injury by recognizing and binding pathogenic microorganisms, modulating the inflammatory response, and promoting the clearance of immune cells. In addition, ficolins are associated with the development and progression of lung diseases (such as pneumonia and ARDS) and may have an important impact on the pathophysiological processes of inflammatory diseases.

Amplifying protection against acute lung injury: Targeting both inflammasome and cGAS-STING pathway by Lonicerae Japonicae Flos-Forsythiae Fructus drug pair

Objective

Acute lung injury (ALI) is characterized by inflammation and currently lacks an efficacious pharmacological intervention. The medicine combination of Lonicerae Japonicae Flos (LJF) and Forsythiae Fructus (FF) demonstrates combined properties in its anti-infective, anti-inflammatory, and therapeutic effects, particularly in alleviating respiratory symptoms. In previous studies, Chinese medicine has shown promising efficacy in lipopolysaccharides (LPS)-induced ALI. However, there have been no reports of LJF and FF pairing for lung injury. The aim of this study is to compare the efficacy of herb pair Lonicerae Japonicae Flos-Forsythiae Fructus (LF) with LJF or FF alone in the treatment of ALI, and to explore whether LJF and FF have a combined effect in the treatment of lung injury, along with the underlying mechanism involved.

Methods

A total of 36 mice were divided into six groups (control, model, LJF, FF, LF, dexamethasone) based on the treatments they received after undergoing sham-operation/LPS tracheal instillation. H&E staining and pulmonary edema indexes were used to evaluate lung injury severity. Alveolar exudate cells (AECs) were counted based on cell count in bronchoalveolar lavage fluid (BALF), and neutrophil percentage in BALF was measured using flow cytometry. Myeloperoxidase (MPO) activity in BALF was measured using enzyme-linked immunosorbent assay (ELISA), while the production of IL-1β, TNF-α, and IL-6 in the lung and secretion level of them in BALF were detected by quantitative polymerase chain reaction (qPCR) and ELISA. The effect of LJF, FF, and LF on the expression of Caspase-1 and IL-1β proteins in bone marrow derived macrophages (BMDMs) supernatant was assessed using Western blot method under various inflammasome activation conditions. In addition, the concentration of IL-1β and changes in lactatedehydrogenase (LDH) release levels in BMDMs supernatant after LJF, FF, and LF administration, respectively, were measured using ELISA. Furthermore, the effects of LJF, FF and LF on STING and IRF3 phosphorylation in BMDMs were detected by Western blot, and the mRNA changes of IFN-β, TNF-α, IL-6 and CXCL10 in BMDMs were detected by qPCR.

Results

LF significantly attenuated the damage to alveolar structures, pulmonary hemorrhage, and infiltration of inflammatory cells induced by LPS. This was evidenced by a decrease in lung index score and wet/dry weight ratio. Treatment with LF significantly reduced the total number of neutrophil infiltration by 75% as well as MPO activity by 88%. The efficacy of LF in reducing inflammatory factors IL-1β, TNF-α, and IL-6 in the lungs surpasses that of LJF or FF, approaching the effectiveness of dexamethasone. In BMDMs, the co-administration of 0.2 mg/mL of LJF and FF demonstrated superior inhibitory effects on the expression of nigericin-stimulated Caspase-1 and IL-1β, as well as the release levels of LDH, compared to individual treatments. Similarly, the combination of 0.5 mg/mL LJF and FF could better inhibit the phosphorylation levels of STING and IRF3 and the production of IFN-β, TNF-α, IL-6, and CXCL10 in response to ISD stimulation.

Conclusion

The combination of LJF and FF increases the therapeutic effect on LPS-induced ALI, which may be mechanistically related to the combined effect inhibition of cyclic-GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) and NOD-like receptor family protein 3 (NLRP3) inflammasomes pathways by LJF and FF. Our study provides new medicine candidates for the clinical treatment of ALI.

Emerging roles of ferroptosis in pulmonary fibrosis: current perspectives, opportunities and challenges

Pulmonary fibrosis (PF) is a chronic interstitial lung disorder characterized by abnormal myofibroblast activation, accumulation of extracellular matrix (ECM), and thickening of fibrotic alveolar walls, resulting in deteriorated lung function. PF is initiated by dysregulated wound healing processes triggered by factors such as excessive inflammation, oxidative stress, and coronavirus disease (COVID-19). Despite advancements in understanding the disease's pathogenesis, effective preventive and therapeutic interventions are currently lacking. Ferroptosis, an iron-dependent regulated cell death (RCD) mechanism involving lipid peroxidation and glutathione (GSH) depletion, exhibits unique features distinct from other RCD forms (e.g., apoptosis, necrosis, and pyroptosis). Imbalance between reactive oxygen species (ROS) production and detoxification leads to ferroptosis, causing cellular dysfunction through lipid peroxidation, protein modifications, and DNA damage. Emerging evidence points to the crucial role of ferroptosis in PF progression, driving macrophage polarization, fibroblast proliferation, and ECM deposition, ultimately contributing to alveolar cell death and lung tissue scarring. This review provides a comprehensive overview of the latest findings on the involvement and signaling mechanisms of ferroptosis in PF pathogenesis, emphasizing potential novel anti-fibrotic therapeutic approaches targeting ferroptosis for PF management.

The guardians of pulmonary harmony: alveolar macrophages orchestrating the symphony of lung inflammation and tissue homeostasis

Recent breakthroughs in single-cell sequencing, advancements in cellular and tissue imaging techniques, innovations in cell lineage tracing, and insights into the epigenome collectively illuminate the enigmatic landscape of alveolar macrophages in the lung under homeostasis and disease conditions. Our current knowledge reveals the cellular and functional diversity of alveolar macrophages within the respiratory system, emphasising their remarkable adaptability. By synthesising insights from classical cell and developmental biology studies, we provide a comprehensive perspective on alveolar macrophage functional plasticity. This includes an examination of their ontology-related features, their role in maintaining tissue homeostasis under steady-state conditions and the distinct contribution of bone marrow-derived macrophages (BMDMs) in promoting tissue regeneration and restoring respiratory system homeostasis in response to injuries. Elucidating the signalling pathways within inflammatory conditions, the impact of various triggers on tissue-resident alveolar macrophages (TR-AMs), as well as the recruitment and polarisation of macrophages originating from the bone marrow, presents an opportunity to propose innovative therapeutic approaches aimed at modulating the equilibrium between phenotypes to induce programmes associated with a pro-regenerative or homeostasis phenotype of BMDMs or TR-AMs. This, in turn, can lead to the amelioration of disease outcomes and the attenuation of detrimental inflammation. This review comprehensively addresses the pivotal role of macrophages in the orchestration of inflammation and resolution phases after lung injury, as well as ageing-related shifts and the influence of clonal haematopoiesis of indeterminate potential mutations on alveolar macrophages, exploring altered signalling pathways and transcriptional profiles, with implications for respiratory homeostasis.

A deep insight into ferroptosis in lung disease: facts and perspectives

In the last decade, ferroptosis has received much attention from the scientific research community. It differs from other modes of cell death at the morphological, biochemical, and genetic levels. Ferroptosis is mainly characterized by non-apoptotic iron-dependent cell death caused by iron-dependent lipid peroxide excess and is accompanied by abnormal iron metabolism and oxidative stress. In recent years, more and more studies have shown that ferroptosis is closely related to the occurrence and development of lung diseases. COPD, asthma, lung injury, lung fibrosis, lung cancer, lung infection and other respiratory diseases have become the third most common chronic diseases worldwide, bringing serious economic and psychological burden to people around the world. However, the exact mechanism by which ferroptosis is involved in the development and progression of lung diseases has not been fully revealed. In this manuscript, we describe the mechanism of ferroptosis, targeting of ferroptosis related signaling pathways and proteins, summarize the relationship between ferroptosis and respiratory diseases, and explore the intervention and targeted therapy of ferroptosis for respiratory diseases.

Paris saponin VII promotes ferroptosis to inhibit breast cancer via Nrf2/GPX4 axis

Breast cancer (BC) is one of the malignancies threatening the woman's health. Our study aims to explore the underlying mechanism behind the anti-tumor function of Paris saponin VII (PS VII) in BC. Xenografting experiment was conducted to monitor the tumor growth. The Ki67 and 4-HNE expression were analyzed via immunohistochemical assay. After different treatments, the cell viability, proliferation, invasion, and migration capacity of BC cells were measured by the CCK-8, colony formation, transwell, and wound healing assays, respectively. The ratio of GSH/GSSG was measured by the GSH/GSSG ratio detection assay kit. The lipid ROS and Fe2+ levels were quantified by flow cytometry analysis. The expressions of TFR1, ACSL4, Nrf2, and GPX4 were measured via western blotting. Compared with the Ctrl group, the tumor volumes, and Ki67 expression were markedly reduced in PS VII groups, and the BC cell viability was decreased by PS VII treatment in a dose-dependent manner. The colony numbers, invasive cells, and migration rates were also significantly decreased by PS VII treatment. Then, the Nrf2 as well as GPX4 expressions were decreased and TFR1 expression was increased by PS VII treatment in vitro and in vivo, while there was no difference in ACSL4 expression between Ctrl and PS VII groups. Moreover, the above effects of PS VII could not be observed in GPX4 knockdown cells. PS VII can promote ferroptosis to inhibit BC via the Nrf2/GPX4 axis, which innovatively suggests the pro-ferroptosis effect and therapeutic potential of PS VII in BC.

Ferroptosis in organ fibrosis: From mechanisms to therapeutic medicines

Fibrosis occurs in many organs, and its sustained progress can lead to organ destruction and malfunction. Although numerous studies on organ fibrosis have been carried out, its underlying mechanism is largely unknown, and no ideal treatment is currently available. Ferroptosis is an iron-dependent process of programmed cell death that is characterized by lipid peroxidation. In the past decade, a growing body of evidence demonstrated the association between ferroptosis and fibrotic diseases, while targeting ferroptosis may serve as a potential therapeutic strategy. This review highlights recent advances in the crosstalk between ferroptosis and organ fibrosis, and discusses ferroptosis-targeted therapeutic approaches against fibrosis that are currently being explored.

Modified Qing-Zao-Jiu-Fei decoction attenuated pulmonary fibrosis induced by bleomycin in rats via modulating Nrf2/NF-κB and MAPKs pathways

BACKGROUND

Qing-Zao-Jiu-Fei Decoction (QZJFD) is a famous herbal formula commonly prescribed for the treatment of lung-related diseases in the ancient and modern times. Trichosanthis Fructus (TF) and Fritillariae Thunbergii Bulbus (FTB) are widely used for treatment of cough and pulmonary disease. In order to identify a more effective formula for treatment of pulmonary fibrosis, we intend to add TF and FTB in QZJFD to form a modified QZJFD (MQZJFD). In this study, we aims to explore MQZJFD as an innovative therapeutic agent for pulmonary fibrosis using bleomycin (BLM)-treated rats and to unravel the underlying molecular mechanisms.

METHODS

BLM was given to SD rats by intra-tracheal administration of a single dose of BLM (5 mg/kg). QZJFD (3 g/kg) and MQZJFD (1, 2 and 4 g/kg) was given intragastrically daily to rats for 14 days (from day 15 to 28) after BLM administration for 14 consecutive days.

RESULTS

MQZJFD was found to contain 0.29% of amygdalin, 0.020% of lutin, 0.077% of glycyrrhizic acid and 0.047% of chlorogenic acid. BLM treatment could induce collagen deposition in the lung tissues of rats, indicating that the pulmonary fibrosis rat model had been successfully established. MQZJFD have better effects than the original QZJFD in reducing the pulmonary structure damage and collagen deposition of rat lung fibrosis induced by BLM. MQZJFD could reduce the hydroxyproline content in lung tissues of BLM-treated rats. The biomarkers of fibrosis such as matrix metalloproteinase 9 (MMP9), collagen I and α-smooth muscle actin (α-SMA) were remarkably reduced after treatment with MQZJFD. MQZJFD also have anti-oxidant stress effects by inhibiting the level of malondialdehyde (MDA), but enhancing the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the level of glutathione (GSH) in the lung tissues of BLM-treated rats. Moreover, the MQZJFD markedly suppressed the over expressions of p-p65/p65 and p-IκBα/IκBα, but upregulated the Nrf2. MQZJFD also suppressed the protein expressions of p-ERK1/2/ERK1/2, p-p38/p38 and p-JNK/JNK in the lung tissues of BLM-treated rats.

CONCLUSIONS

MQZJFD could improve the pulmonary fibrosis induced by BLM in rats via inhibiting the fibrosis and oxidative stress via suppressing the activation of NF-κB/Nrf2 and MAPKs pathways.

Recent progress in biomaterials-driven ferroptosis for cancer therapy

Ferroptosis, first suggested in 2012, is a type of non-apoptotic programmed cell death caused by the buildup of lipid peroxidation and marked by an overabundance of oxidized poly unsaturated fatty acids. During the last decade, researchers have uncovered the formation of ferroptosis and created multiple drugs aimed at it, but due to poor selectivity and pharmacokinetics, clinical application has been hindered. In recent years, biomedical discoveries and developments in nanotechnology have spurred the investigation of ferroptosis nanomaterials, providing new opportunities for the ferroptosis driven tumours treatment. Additionally, hydrogels have been widely studied in ferroptosis because of their unique 3D structure and excellent controllability. By using these biomaterials, it is possible to achieve controlled release and targeted delivery of drugs, thus increasing the potency of the drugs and minimizing adverse effects. Therefore, summarizing the biomedical nanomaterials, including hydrogels, used in ferroptosis for cancer therapy is a must. This article provides an overview of ferroptosis, detailing its properties and underlying mechanisms. It also categorizes and reviews the use of various nanomaterials in ferroptosis, along with relevant explanations and illustrations. In addition, we discuss the opportunities and challenges facing the application of nanomaterials in ferroptosis. Finally, the development prospects of this field are prospected. This review is intended to provide a foundation for the development and application of biomedical nanomaterials in ferroptosis.

Improving cancer immunotherapy by preventing cancer stem cell and immune cell linking in the tumor microenvironment

Cancer stem cells are the key link between malignant tumor progression and drug resistance. This cell population has special properties that are different from those of conventional tumor cells, and the role of cancer stem cell-related exosomes in progression of tumor malignancy is becoming increasingly clear. Cancer stem cell-derived exosomes carry a variety of functional molecules involved in regulation of the microenvironment, especially with regard to immune cells, but how these exosomes exert their functions and the specific mechanisms need to be further clarified. Here, we summarize the role of cancer stem cell exosomes in regulating immune cells in detail, aiming to provide new insights for subsequent targeted drug development and clinical strategy formulation.

The role of cGAS-STING signaling in pulmonary fibrosis and its therapeutic potential

Pulmonary fibrosis is a progressive and ultimately fatal lung disease, exhibiting the excessive production of extracellular matrix and aberrant activation of fibroblast. While Pirfenidone and Nintedanib are FDA-approved drugs that can slow down the progression of pulmonary fibrosis, they are unable to reverse the disease. Therefore, there is an urgent demand to develop more efficient therapeutic approaches for pulmonary fibrosis. The intracellular DNA sensor called cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) plays a crucial role in detecting DNA and generating cGAMP, a second messenger. Subsequently, cGAMP triggers the activation of stimulator of interferon genes (STING), initiating a signaling cascade that leads to the stimulation of type I interferons and other signaling molecules involved in immune responses. Recent studies have highlighted the involvement of aberrant activation of cGAS-STING contributes to fibrotic lung diseases. This review aims to provide a comprehensive summary of the current knowledge regarding the role of cGAS-STING pathway in pulmonary fibrosis. Moreover, we discuss the potential therapeutic implications of targeting the cGAS-STING pathway, including the utilization of inhibitors of cGAS and STING.