Melatonin attenuates LPS-induced pyroptosis in acute lung injury by inhibiting NLRP3-GSDMD pathway via activating Nrf2/HO-1 signaling axis

Tetramethylpyrazine Confers Protection Against Oxidative Stress and NLRP3-Dependent Pyroptosis in Rats with Endometriosis

Tetramethylpyrazine (TMP) has been confirmed to suppress inflammation in endometriosis (EMs). Herein, this study investigated whether and how TMP affected NLRP3 inflammasomes and oxidative stress in EMs. After establishment of an EMs rat model, rats were treated with different concentrations of TMP. The size of endometriotic lesions and the latency and frequency of torsion in rats were recorded, followed by the measurement of relevant indicators (TNF-α, IL-6, IL-2, IL-10, MDA, SOD, GSH, CAT, ROS, NLRP3, ASC, GSDMD, caspase-1, Nrf2, and HO-1). The study experimentally determined that TMP treatment markedly decreased the size of endometriotic lesions and improved torsion in rats with EMs. The levels of inflammatory proteins, oxidative stress markers, NLRP3 inflammasome, and pyroptotic proteins were elevated in rats with EMs, all of which were reversed upon TMP treatment. Additionally, the activities of SOD, GSH, and CAT were lowered in rats with EMs, which were partly abrogated by TMP treatment. Furthermore, the downregulation of Nrf2 and HO-1 was counteracted by TMP treatment. To sum up, TMP represses excessive oxidative stress, NLRP3 inflammasome activation, and pyroptosis in rats with EMs. Additionally, TMP may activate the Nrf2/HO-1 pathway.

Acidity-unlocked glucose oxidase as drug vector to boost intratumor copper homeostatic imbalance-enhanced cuproptosis for metastasis inhibition and anti-tumor immunity

As one of the key tools of biocatalysis, natural enzymes have received extensive attention due to their unique activity. However, the non-selective catalysis and early leakage induced by delivery dependency of natural enzymes can cause side effects on normal tissues. Moreover, although cuproptosis is an emerging tumor-inhibiting programmed cell death, the occurrence of cuproptosis leads to high expression of Cu-dependent lysyl oxidase-like 2 (LOXL2), which promotes tumor metastasis. Herein, in order to intelligently regulate the "OFF-to-ON" catalytic activity of glucose oxidase (a natural enzyme called GOx) and simultaneously inhibit tumor metastasis caused by Cu imbalance, an acidity-unlocked GOx system drug carrier was constructed by co-assembling Cu ions and omeprazole (OPZ) on GOx exposing sulfhydryl and hydrophobic pockets. The GOx activity is significantly inhibited due to the coordination of Cu ions with sulfhydryl groups and the interaction of hydrophobic small molecule OPZ with hydrophobic bags, which results in specificity for tumor cells and ensures the safety of GOx in blood circulation. Meanwhile, dysregulation of intracellular Cu homeostasis that impairs the Cu-dependence of LOXL2 not only inhibits critical signaling during epithelial-mesenchymal transformation (EMT) and extracellular matrix (ECM) remodelling to prevent tumor metastasis, but also exacerbates enhanced cuproptosis induced by tumor metabolic stress, thereby reversing the immunosuppressive microenvironment. This strategy of acidity-unlocked the catalytic function of natural enzymes and LOXL2 activity inhibition provides a novel option for enhancing cuproptosis to inhibit tumor metastasis and anti-tumor immunity.

Exploration of ω-9MUFAs: Mitigating effect on lipopolysaccharide-induced acute lung injury

Given the demonstrated mitigating effect of omega-9 monounsaturated fatty acids (ω-9MUFAs) on lipopolysaccharide (LPS)-induced acute lung injury (ALI), we deeply explored corresponding mechanisms. Sprague-Dawley rats experienced ALI modeling, and received ω-9 MUFAs (3 mg/kg) injection via the tail vein. Post incubation in 100 ng/mL phorbol-12-myristate-13-acetate and 100 ng/mL LPS for 24 h each, THP-1 macrophages were transfected with shHSPH1 and c-MYC overexpression plasmid. Lung injury detection depended on H&E staining. Levels of inflammation-related factors were detected by ELISA. Levels of inflammation-related factors, heat shock protein family H (Hsp110) member 1 (HSPH1), c-MYC, stimulator of interferon response CGAMP interactor 1 (STING) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) were measured by qRT-PCR. Levels of pyroptosis-related factors, HSPH1, c-MYC, STING, NLRP3, and M1 macrophage biomarkers were assayed by Western blot. Proportion of M1 macrophages and pyroptosis were detected by flow cytometry. Localization of HSPH1 and CD68 was measured by immunofluorescence assay. ω-9MUFAs reduced the inflammation, the proportion of M1 and pyroptotic macrophages and levels of HSPH1, c-MYC, STING and NLRP3 in ALI rats. The expression positions of HSPH1 and CD68 were overlapped in ALI rat lung tissue. HSPH1 silencing reversed the changes in inflammation, the proportion of M1 and pyroptotic macrophages and levels of c-MYC, STING and NLRP3 in LPS-induced THP-1 macrophages, and c-MYC overexpression offset these effects of HSPH1 silencing. Collectively, ω-9MUFAs ameliorated LPS-induced ALI by regulating HSPH1/c-MYC expression, down-regulating M1 macrophage polarization and pyroptosis.

Inhibition of histone acetyltransferase KAT8 inhibits oxidative stress and NLRP3 inflammasome activation through reducing p53 acetylation in LPS-induced acute lung injury

OBJECTIVE

Acute lung injury (ALI) remains a life-threatening condition characterized by excessive inflammation and oxidative stress. This study aimed to investigate the role of Lysine acetyltransferase 8 (KAT8) in lipopolysaccharide (LPS)-induced ALI and explore its underlying molecular mechanisms.

METHODS

Gene and protein expression were analyzed via RT-qPCR and Western blot. Molecular interactions were validated using Co-immunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP), and luciferase reporter assays. Lung histopathology was evaluated by H&E staining. Oxidative stress markers (SOD, MPO, MDA, ROS) were quantified.

RESULTS

KAT8 expression was elevated in LPS-treated cells and lung tissues. Genetic silencing of KAT8 attenuated LPS-induced inflammatory cytokine secretion, oxidative stress, and NLRP3 inflammasome activation. Mechanistically, KAT8 promoted p53 acetylation, enhancing its binding to the NLRP3 promoter and upregulating its transcription. Conversely, p53 knockdown abolished KAT8-mediated inflammatory cytokine secretion, oxidative stress, and NLRP3 inflammasome activation in LPS-induced ALI. In vivo, pharmacological inhibition of KAT8 with MG149 alleviated LPS-induced ALI as evidenced by reduced neutrophil infiltration, pulmonary edema, and oxidative damage. Concurrently, MG149 suppressed p53 acetylation and NLRP3 activation in murine lungs.

CONCLUSION

This study identifies KAT8 as a key epigenetic regulator driving LPS-induced ALI via the p53/NLRP3 axis. Targeting KAT8 with MG149 represents a promising therapeutic strategy to mitigate inflammation and oxidative injury in ALI.

Targeting alveolar macrophages: a promising intervention for pulmonary infection and acute lung injury

Pulmonary infections are common respiratory diseases caused by a variety of pathogens, some of which can lead to epidemics. When they progress to acute lung injury or acute respiratory distress syndrome, the mortality rate is high and effective treatment options are lacking. Macrophages play a crucial role in the development and progression of lung injury, and serve as core components of immune regulation in the lungs. Therefore, regulation of macrophages to intervene in the progression of infection-induced lung injury is a promising research direction. However, the existence of different macrophage subsets and their inherent heterogeneity has led to the failure of many studies to achieve effective results, thereby limiting their clinical applications. We believe that interventions targeting macrophages must consider factors, such as macrophage subsets, timing of interventions, patients' varying immune states, and clinical stages, rather than simply focusing on regulating their phenotypes. This distinction is the key to the success of macrophage-targeted therapies. In this review, we summarize the characteristics of two distinct macrophage subpopulations, lung-tissue-resident alveolar macrophages and monocyte-derived macrophages, along with intervention strategies and research progress at various time points, with the aim of providing insights and directions for future research.

Cornus officinalis loganin attenuates acute lung injury in mice via regulating the PI3K/AKT/NLRP3 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis (CO), a pharmaceutical and food product, can reduce inflammation, alleviate oxidative stress and lower blood sugar levels. In particular, CO has been used to treat severe COVID-19 patients during the pandemic, revealing its protective effects against pneumonia.

AIM

In this study, the mitigating effects of CO ethanol extract (COEE) on acute lung injury (ALI) and the molecular mechanism were investigated and the main active components of COEE were screened.

METHODS

The anti-inflammatory effects of CO on model animals assessed by evaluating the levels of proinflammatory factors and inflammasome components by H&E staining technique, ELISA, RT‒qPCR and immunofluorescence assays. Moreover, CCK8, LDH, and RT‒qPCR assays were also performed to assess the effect of CO on cell viability and its anti-inflammatory efficacy in vitro. The mRNA expression of inflammatory factors (IL-1β and TNF-α), and the protein expression of NLRP3 inflammasome members was evaluated. In addition, the molecular mechanisms and core pharmacodynamic components of CO were inferred by network pharmacology, and the relevant pathway targets were analyzed and verified by immunohistochemistry, Western blotting and RT‒qPCR. In vivo and in vitro models were also established to verify the effects of the main active ingredient Loganin (LOG) on ALI and the related molecular mechanisms.

RESULTS

COEE significantly suppressed inflammation, mitigated lung tissue damage, and inhibited NLRP3 inflammasome activation in an LPS-induced murine ALI model and an inflammatory cell model. Network pharmacology screening and experimental data revealed that the PI3K/AKT signalling pathway is the direct target of CO, as COEE administration potently inhibited the activation of the PI3K/AKT/NLRP3 signalling pathway in vitro and in vivo, whereas the PI3K/AKT pathway agonist YS-49 apparently impaired the effects of COEE. Further studies revealed that LOG, a core ingredient in CO, mediated the effects of COEE via direct targeting of AKT1, and different doses of LOG had consistent and strong protective effects on ALI model mice.

CONCLUSION

COEE exerts therapeutic effects on LPS-induced ALI model mice by inhibiting the activation of the PI3K/AKT pathway and preventing the overactivation of the NLRP3 inflammasome, and LOG is the core medicinal substance. These findings also provide supporting evidence for the development of new nutraceuticals for the prevention and treatment of ALI.

Paeoniflorin alleviated experimental Sjögren's syndrome by inhibiting NLRP3 inflammasome activation of submandibular gland cells via activating Nrf2/HO-1 pathway

BACKGROUND

Total glucosides of white paeony (TGP) has been used for treatment of Sjögren's syndrome (SS) patients. Paeoniflorin (PF) is the main active ingredient of TGP and has antioxidant and anti-inflammatory effects, but its underlying mechanism on SS remains to be explored. Aberrant activation of NLRP3 inflammasome can cause injury of submandibular gland (SG) in SS. However, whether PF regulates NLRP3 inflammasome activation in SS is unknown.

OBJECTIVE

This study aims to investigate whether PF alleviated SS through suppressing NLRP3 inflammation activation and to explore the mechanism of PF in improving Sjögren-like symptoms in non-obese diabetic (NOD) mice.

METHODS

The gene expression profiles of the labial gland (LG) between SS patients and non-SS patients were analyzed by bioinformatics. Non-obese diabetic (NOD) mice were selected as SS model. Mice were divided into normal saline group and two different doses of PF-treatment groups (50 and 100 mg/kg). The SS-like symptoms and pathological changes of submandibular gland (SG) were analyzed after 4 weeks of administration. SG cells were treated with or without PF and with or without ML385 (a specific inhibitor of Nrf2) in vitro, and then lipopolysaccharide(LPS) and adenosine triphosphate (ATP) were used to induce NLRP3 inflammasome activation in SG cells. Results NLRP3 was up-regulated in LG of SS patients and SG of SS mice. PF alleviated SS-like symptoms in SS mice. Compared with control group, NLRP3 and caspase-1 in the SG, and serum IL-1β and IL-18 of NOD mice were decreased in PF group. Furthermore, we found that PF inhibited NLRP3 activation via activating the Nrf2/HO-1 pathway in SG cells. In addition, we observed the activation of Nrf2/HO-1 in the SG of mice after PF administration.

CONCLUSIONS

Our findings suggested that PF inhibited NLRP3 inflammasome activation through regulating the Nrf2/HO-1 axis in SG of SS mice, which might be the underlying mechanism for the therapeutic effects of PF on SS.

Melatonin ameliorates retinal neurovascular degeneration in Rd1 mice by inhibiting oxidativestress

Oxidative stress has been involved in the occurrence of retinal photoreceptor degeneration and retinal vascular dysfunctions. This study investigated the effects of melatonin (MLT) on neurovascular changes in rd1 mice, evaluating its therapeutic potential as an antioxidant for retinal degeneration. MLT was administered to rd1 mice at postnatal day 7 (P7), and retinal vascular alterations were assessed using retina flatmounts, while neural and functional changes were evaluated through frozen sections and electroretinography at P14. In vitro, human retinal microvascular endothelial cells (HRMECs) were treated with MLT to counteract oxidative stress induced by H2O2. Analyses included assessments of cell function, apoptosis, oxidative stress, and inflammatory markers in both in vivo and in vitro models. The results demonstrated that MLT significantly improved retinal vascular densities in the deep and superficial layers at P14 and P21, though not fully restoring them to wild-type levels. Additionally, MLT exerted protective effects against photoreceptor degeneration, oxidative stress, and inflammation, partially preserving retinal function. In vitro, MLT alleviated functional abnormalities and reduced cell death in HRMECs by decreasing reactive oxygen species levels. These findings suggest that MLT holds promise as a therapeutic approach for retinal degeneration by mitigating oxidative stress, thereby protecting photoreceptors and retinal vasculature. This underscores the importance of vascular preservation in developing therapeutic strategies for retinal degenerative diseases.

Melatonin Interplay in Physiology and Disease-The Fountain of Eternal Youth Revisited

Melatonin (N-acetyl-5-methoxytryptamine) is a hormone associated with the regulation of biological rhythms. The indoleamine is secreted by the pineal gland during the night, following a circadian rhythm. The highest plasmatic levels are reached during the night, whereas the lowest levels are achieved during the day. In addition to the pineal gland, other organs and tissues also produce melatonin, like, for example, the retina, Harderian glands, gut, ovaries, testes, skin, leukocytes, or bone marrow. The list of organs is extensive, including the cerebellum, airway epithelium, liver, kidney, adrenals, thymus, thyroid, pancreas, carotid body, placenta, and endometrium. At all these locations, the availability of melatonin is intended for local use. Interestingly, a decline of the circadian amplitude of the melatonin secretion occurs in old subjects in comparison to that found in younger subjects. Moreover, genetic and environmental factors are the primary causes of diseases, and oxidative stress is a key contributor to most pathologies. Numerous studies exist that show interesting effects of melatonin in different models of disease. Impairment in its secretion might have deleterious consequences for cellular physiology. In this regard, melatonin is a natural compound that is a carrier of a not yet completely known potential that deserves consideration. Thus, melatonin has emerged as a helpful ally that could be considered as a guard with powerful tools to orchestrate homeostasis in the body, majorly based on its antioxidant effects. In this review, we provide an overview of the widespread actions of melatonin against diseases preferentially affecting the elderly.

NLRP3 Inflammasome-mediated pyroptosis in acute lung injury: Roles of main lung cell types and therapeutic perspectives

The NLRP3 inflammasome plays a pivotal role in the pathogenesis of acute lung injury (ALI) by regulating pyroptosis, a highly inflammatory form of programmed cell death. NLRP3-mediated pyroptosis leads to alveolar epithelial cell injury, increased pulmonary microvascular endothelial permeability, excessive alveolar macrophage activation, and neutrophil dysfunction, collectively driving ALI progression. In addition to the classical NLRP3-dependent pathway, the non-canonical pyroptosis pathway (caspase-4/5/11) also contributes to ALI by inducing pyroptotic cell death in AECs and ECs, further amplifying NLRP3 activation through damage-associated molecular patterns (DAMP) release. Moreover, neutrophils (NE) pyroptosis exhibits dual roles in ALI, as it enhances pathogen clearance but also exacerbates excessive inflammation and tissue damage, highlighting the complexity of its regulation. Targeting the NLRP3 inflammasome and pyroptotic pathways has emerged as a promising therapeutic strategy for ALI. Various NLRP3 inhibitors (e.g., MCC950, CY-09, OLT1177) and pyroptosis inhibitors have demonstrated significant anti-inflammatory and tissue-protective effects in preclinical models. However, the clinical translation of NLRP3-targeted therapies remains challenging due to off-target effects, potential immunosuppression, lack of patient stratification strategies, and compensatory activation of alternative inflammasomes (e.g., AIM2, NLRC4). Future studies should focus on optimizing the selectivity of NLRP3 inhibitors, developing personalized therapeutic approaches, and exploring combination strategies to enhance their clinical applicability in ALI.

Melatonin alleviates sepsis-induced acute lung injury by inhibiting necroptosis via reducing circulating mtDNA release

BACKGROUND

Sepsis is a life-threatening condition that often leads to severe complications, including acute lung injury (ALI), which carries high morbidity and mortality in critically ill patients. Melatonin (Mel) has shown significant protective effects against sepsis-induced ALI, but its precise mechanism remains unclear.

METHODS

A cecal ligation and puncture (CLP) model was used to induce sepsis in male C57BL/6 mice, which were divided into four groups: Control, Sham, CLP, and CLP + Mel. ALI severity was evaluated via hematoxylin and eosin (H&E) staining, lung wet/dry ratio, and serum biomarkers (SP-D, sRAGE). Inflammatory cytokines (IL-1β, IL-6, TNF-α) were measured in serum and bronchoalveolar lavage fluid using ELISA. Circulating mitochondrial DNA (mtDNA) subtypes (D-loop, mt-CO1, mMito) were quantified by real-time PCR. TUNEL staining was performed to assess lung cell apoptosis. Necroptosis and STING pathway activation were analyzed via Western blot and immunofluorescence.

RESULTS

Sepsis led to increased circulating mtDNA levels and activation of necroptosis signaling pathways. Melatonin treatment alleviated sepsis-induced ALI, improving survival, reducing inflammatory cytokines and mtDNA release, and suppressing necroptosis. Intraperitoneal injection of mtDNA in mice activated necroptosis, while RIP1 inhibitor Nec-1 counteracted mtDNA-induced lung damage and necroptosis in sepsis-induced ALI. Additionally, melatonin significantly inhibited STING pathway activation. Further experiments revealed that STING modulation influenced necroptosis protein expression and mediated melatonin's protective effects in sepsis-induced ALI.

CONCLUSION

Melatonin mitigates sepsis-induced ALI by suppressing necroptosis through inhibition of STING activation and reduction of mtDNA release. These findings suggest melatonin as a potential therapeutic strategy for sepsis-induced ALI.

Mitochondrial dynamics and metabolism in macrophages for cardiovascular disease: A review

BACKGROUND

Mitochondria regulate macrophage function, affecting cardiovascular diseases like atherosclerosis and heart failure. Their dynamics interact with macrophage cell death mechanisms, including apoptosis and necroptosis.

PURPOSE

This review explores how mitochondrial dynamics and metabolism influence macrophage inflammation and cell death in CVDs, highlighting therapeutic targets for enhancing macrophage resilience and reducing CVD pathology, while examining molecular pathways and pharmacological agents involved.

STUDY DESIGN

This is a narrative review that integrates findings from various studies on mitochondrial dynamics and metabolism in macrophages, their interactions with the endoplasmic reticulum (ER) and Golgi apparatus, and their implications for CVDs. The review also considers the potential therapeutic effects of pharmacological agents on these pathways.

METHODS

The review utilizes a comprehensive literature search to identify relevant studies on mitochondrial dynamics and metabolism in macrophages, their role in CVDs, and the effects of pharmacological agents on these pathways. The selected studies are analyzed and synthesized to provide insights into the complex relationships between mitochondria, the ER, and Golgi apparatus, and their implications for macrophage function and fate.

RESULTS

The review reveals that mitochondrial metabolism intertwines with cellular architecture and function, particularly through its intricate interactions with the ER and Golgi apparatus. Mitochondrial-associated membranes (MAMs) facilitate Ca2+ transfer from the ER to mitochondria, maintaining mitochondrial homeostasis during ER stress. The Golgi apparatus transports proteins crucial for inflammatory signaling, contributing to immune responses. Inflammation-induced metabolic reprogramming in macrophages, characterized by a shift from oxidative phosphorylation to glycolysis, underscores the multifaceted role of mitochondrial metabolism in regulating immune cell polarization and inflammatory outcomes. Notably, mitochondrial dysfunction, marked by heightened reactive oxygen species generation, fuels inflammatory cascades and promotes cell death, exacerbating CVD pathology. However, pharmacological agents such as Metformin, Nitazoxanide, and Galanin emerge as potential therapeutic modulators of these pathways, offering avenues for mitigating CVD progression.

CONCLUSION

This review highlights mitochondrial dynamics and metabolism in macrophage inflammation and cell death in CVDs, suggesting therapeutic targets to improve macrophage resilience and reduce pathology, with new pharmacological agents offering treatment opportunities.

Exploring the therapeutic potential of HAPC in COVID-19-induced acute lung injury

BACKGROUND

Acute lung injury (ALI) is one of the critical complications of coronavirus disease 2019 (COVID-19), which significantly impacts the survival of patients.

PURPOSE

In this study, we screened COVID-19-related target genes and identified and optimized potential drugs targeting these genes for the treatment of COVID-19.

STUDY DESIGN

In this study, bioinformatic analyses were conducted and subsequently identified and optimized potential drugs targeting these genes for the treatment of COVID-19 were carried out.

METHODS

Firstly, we analyzed the targets gene in patients with COVID-19 using single-cell data analysis. We performed structural modifications on Chicoric acid (CA) and combined it with hyaluronic acid to enhance the targeted activity towards Cluster of differentiation 44 (CD44). Poly (sodium-p styrenesulfonate) (PSS) was used to form a PSS-coated CA+hyaluronic acid nanocomplex (HA-P). Subsequently, Lactobacillus murinus conidia cell wall (CW) was encapsulated to prepare PSS-coated CA + hyaluronic acid + Lactobacillus murinus conidia cell wall (HAPC) nanocomplexes.

RESULTS

The expression of APPL1 expression in macrophage of COVID-19 patients was up-regulation. CA was found to bind to the APPL1 protein and inhibit its ubiquitination. HAPC effectively targeted ALI through the highly efficient interaction between CD44 and Hyaluronic acid (HA). HAPC alleviated the symptoms of ALI and restored epithelial function in mice with ALI. HAPC induced the Adaptor protein containing a pH domain, PTB domain and leucine zipper motif 1 (APPL1)/ liver kinase B1 (LKB1)/ AMP-activated protein kinase (AMPK) pathway by inactivating the NOD - like receptor protein 3 (NLRP3) pathway in ALI. CA interacted with the APPL1 protein and prevented its ubiquitination. HAPC facilitated the interaction between APPL1 and LKB1 to induce the AMPK/NLRP3 pathway. It promoted the formation of LKB1 at GLU-67, ARG-72, ARG-314, ASP-316, and GLN-312 and APPL1 at ARG-106, ASP-115, LYS-124, ASN-119, and GLU-120.

CONCLUSION

Altogether, HAPC nanocomplexes exerted anti-inflammatory effects on ALI by promoting the interaction between APPL1 and LKB1 to induce the AMPK/NLRP3 pathway, and may be one new therapeutic strategie for ALI.

Melatonin-Loaded Hydrogel Modulates Circadian Rhythms and Alleviates Oxidative Stress and Inflammation to Promote Wound Healing

Circadian rhythm disruption, commonly caused by factors such as jet lag and shift work, is increasingly recognized as a critical factor impairing wound healing. Although melatonin is known to regulate circadian rhythms and has potential in wound repair, its clinical application is limited by low bioavailability. To address these challenges, we developed an alginate-based dual-network hydrogel as a delivery system for melatonin, ensuring its stable and sustained release at the wound site. This approach enhances the efficacy of melatonin in modulating the wound healing process. We investigated the effects of circadian rhythm disruption on the wound microenvironment under the influence of the melatonin-loaded hydrogel with a focus on its biocompatibility, hemostatic properties, and antioxidant response functions. Additionally, we elucidated the mechanisms by which the melatonin-loaded hydrogel system promotes wound healing. Our findings provide insights into the relationship between circadian rhythm disruption and wound healing, offering a promising strategy for the management of chronic wounds associated with circadian rhythm disorders.

Macrophage pyroptosis and its crucial role in ALI/ARDS

Acute lung injury(ALI)/acute respiratory distress syndrome(ARDS) is a severe clinical syndrome characterized by high morbidity and mortality, primarily due to lung injury. However, the pathogenesis of ALI/ARDS remains a complex issue. In recent years, the role of macrophage pyroptosis in lung injury has garnered extensive attention worldwide. This paper reviews the mechanism of macrophage pyroptosis, discusses its role in ALI/ARDS, and introduces several drugs and intervening measures that can regulate macrophage pyroptosis to influence the progression of ALI/ARDS. By doing so, we aim to enhance the understanding of the mechanism of macrophage pyroptosis in ALI/ARDS and provide novel insights for its treatment.

Extract of Nanhaia speciosa J. Compton & Schrire alleviates LPS-induced acute lung injury via the NF-κB/Nrf2/AQPs pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Nanhaia speciosas J. Compton & Schrire (the name Nanhaia speciosas J. Compton & Schrire has been accepted by the World Checklist of Vascular Plants https://www.worldfloraonline.org/taxon/wfo-0001444004) is a traditional Zhuang medicine that have been widely used for centuries. It has been used in the treatment of lung inflammation, tuberculosis, rheumatic pain, lumbar muscle strain, and various other ailments, such as chronic hepatitis, menoxenia, leukorrhea, and injuries. In addition, N. speciosa has also been used to treat acute lung injury (ALI).

AIM OF THE STUDY

The objective of this study was to conduct a comparative analysis of the effects of various constituents present in N. speciosas extract (NSE) on ALI and the related mechanisms while also elucidating the potential active monomeric components.

MATERIALS AND METHODS

NSE was extracted using an AB-8 macroporous resin column, and five fractions (Fr. 0%, 25%, 50%, 75% and 95%) were obtained. The anti-inflammatory and antioxidant capacities of the five fractions were evaluated in an A549 cell-based in vitro model, with the aim of evaluating their potential therapeutic effects. The anti-inflammatory and antioxidant capacities of NSE were assessed in a murine model of ALI induced by intratracheal injection of LPS. We utilized an in vitro model to analyse the critical molecular mechanisms through which NSE ameliorates ALI. The chemical composition of the optimal fraction was analysed and confirmed using UHPLC/MS.

RESULTS

Different fractions (especially Fr. 75%) significantly reduced inflammation and oxidative stress in A549 cells. Fr.75% abrogated LPS-induced pathological alterations and decreased the lung W/D ratio, total protein concentration in BALF, and the levels of the proinflammatory factors TNF-α, IL-6, and IL-1β. Moreover, Fr.75% reduced MPO and MDA concentrations and elevated SOD and GSH concentrations in pulmonary tissues. Additionally, it decreased the pulmonary tissue inflammation caused by LPS by downregulating the expression of p-NF-κB p65 and upregulating the expression of Nrf2, AQP1 and AQP5. Fr. 75% decreased p-NF-κB p65 protein levels; increased Keap1, Nrf2, HO-1, NQO1, AQP1 and AQP5 protein levels; and promoted the entry of Nrf2 into the nucleus. After UHPLC/MS analysis was conducted, the flavonoid Maackiain was determined to potentially play a pivotal role in this process.

CONCLUSION

Fr.75% alleviates ALI by regulating the NF-κB/Nrf2/AQPs signalling pathway. The flavonoid Maackiain may also play an important role in this process. Overall, N. speciosas may be a potential therapeutic agent for the prevention and treatment of ALI.

The Protective Effects of Annexin A1 in Acute Lung Injury Mediated by Nrf2

BACKGROUND

Acute lung injury (ALI), one of the most severe respiratory system diseases, is prevalent worldwide. Annexin A1 (AnxA1) is an important member of the annexin superfamily, known for its wide range of physiological functions. However, its potential protective effect against lipopolysaccharide (LPS)-induced ALI remains unclear.

MATERIALS AND METHODS

Mice were divided into four groups: Sham, LPS + vehicle, LPS + 0.1 μg AnxA1, and LPS + 0.5 μg AnxA1. Lung injury was assessed through histopathology, pulmonary wet-to-dry (W/D) ratio, cell counting of bronchoalveolar lavage fluid (BALF), oxidative stress analysis, and noninvasive pulmonary function testing. Gene and protein expression levels were measured using RT-PCR, ELISA, and western blot analysis.

RESULTS

AnxA1 alleviated LPS-induced ALI by protecting lung tissue from damage, reducing the lung wet/dry (W/D) weight ratio, and improving LPS-induced impaired lung function. Interestingly, administration of AnxA1 was found to repress the infiltration of inflammatory cells by decreasing the total cell count, neutrophils, and protein concentrations in bronchoalveolar lavage fluid (BALF). AnxA1 mitigated the inflammatory response in the pulmonary tissue by lowering the levels of IL-1β, IL-6, and TNF-α in BALF of ALI mice. Additionally, AnxA1 attenuated oxidative stress in lung tissues of ALI mice by restoring the activity of catalase (CAT), SOD, and glutathione (GSH) but reducing the levels of malondialdehyde (MDA). We also found that AnxA1 suppressed activation of the NLRP3 signaling pathway. Mechanistically, AnxA1 activated the Nrf2/HO-1 signaling pathway while preventing the activation of NF-κB.

CONCLUSION

Collectively, these findings suggest that AnxA1 alleviates LPS-induced ALI and might be a promising novel therapeutic agent against LPS-induced ALI.

Impact of fecal microbiota transplantation on lung function and gut microbiome in an ARDS rat model: A multi-omics analysis including 16S rRNA sequencing, metabolomics, and transcriptomics

OBJECTIVE

Acute respiratory distress syndrome (ARDS) is a severe pulmonary condition characterized by inflammation and lung damage, frequently resulting in poor clinical outcomes. Recent studies suggest that the gut-lung axis, mediated by gut microbiota, is critical in ARDS progression. This study investigates the therapeutic potential of fecal microbiota transplantation (FMT) in an ARDS rat model (n = 6).

INTRODUCTION

The pathogenesis of ARDS involves complex interactions between the lungs and gut, with microbiota playing a key role. Understanding the effects of FMT on lung function and gut microbiota may provide new therapeutic strategies for ARDS management.

METHODS

Sprague-Dawley rats were pre-treated with a broad-spectrum antibiotic cocktail to create a germ-free state and subsequently exposed to intranasal lipopolysaccharide to induce ARDS. The rats then received FMT treatment. Lung samples were analyzed using histopathology and transcriptomics. Fecal samples were analyzed using 16S rRNA sequencing and metabolomics.

RESULTS

FMT treatment significantly reduced lung injury and improved pulmonary function, as evidenced by increased partial pressure of arterial oxygen (PaO2) and decreased partial pressure of arterial carbon dioxide (PaCO2). FMT also significantly altered in gut microbiota composition by regulating the gut microbiota composition of Akkermansia and Lactobacillus, restoring the abundance of genera such as Muribaculaceae, Clostridia_UCG-014, Prevotella, and Adlercreutzia, while reducing Romboutsia. FMT restored key metabolic pathways involved in lipid metabolism, amino acid biosynthesis, and immune regulation, including the modulation of immune pathways like mTOR signaling. These alterations contribute to reduced lung injury and improved pulmonary function.

CONCLUSION

These findings indicate that FMT may exert its beneficial effects in ARDS by modulating the gut microbiota and enhancing metabolic and immune responses. However, given that this study remains in the preclinical stage, further validation in clinical studies is necessary before considering clinical application.

Antioxidant and Anti-Inflammatory Properties of Melatonin in Secondary Traumatic Brain Injury

Traumatic brain injury (TBI) is a disease resulting from external physical forces acting against the head, leading to transient or chronic damage to brain tissue. Primary brain injury is an immediate and, therefore, rather irreversible effect of trauma, while secondary brain injury results from a complex cascade of pathological processes, among which oxidative stress and neuroinflammation are the most prominent. As TBI is a significant cause of mortality and chronic disability, with high social costs all over the world, any form of therapy that may mitigate trauma-evoked brain damage is desirable. Melatonin, a sleep-wake-cycle-regulating neurohormone, exerts strong antioxidant and anti-inflammatory effects and is well tolerated when used as a drug. Due to these properties, it is very reasonable to consider melatonin as a potential therapeutic molecule for TBI treatment. This review summarizes data from in vitro studies, animal models, and clinical trials that focus on the usage of melatonin in TBI.

Macrophage-derived exosomal miR-2137 regulates pyroptosis in LPS-induced acute lung injury

BACKGROUND

Alveolar macrophages (AMs) play a predominant role in acute lung injury (ALI). However, the role of macrophage-derived exosomal miRNAs in lipopolysaccharide (LPS)-induced ALI has not been determined.

METHODS

We previously reported that exosomes in the bronchoalveolar lavage fluid (BALF) of mice with ALI were derived predominantly from macrophages. Exosomal small RNA sequencing was conducted to identify the miRNA profiles. Exosomes derived from LPS-induced macrophages (LPS-exos) were intravenously administered to C57BL/6J mice, after which lung injury and pyroptosis were assessed. LPS-exos were cultured with alveolar epithelial cells (AECs) to further validate the results of the animal studies.

RESULTS

LPS-exos promoted lung inflammation and pyroptosis in vivo and in vitro. MiR-2137 was significantly upregulated in both LPS-exos and in MLE-12 cells. LPS-exos reduced cell viability, promoted the expression of LDH and inflammatory cytokines, and exacerbated vacuolization in MLE-12 cells. The administration of miR-2137 mimics and LPS-treated exosomes further strengthened these effects and enhanced pyroptosis mediated by NLRP3, Caspase1, ASC, and GSDMD. MiR-2137 mediated the effects of LPS-exos by targeting Wnt9a in AECs. In addition, the miR-2137 inhibitor markedly decreased the severity of LPS-exo-induced histological lesions, inflammation and pyroptosis in the lung.

CONCLUSION

Exosomal miR-2137 derived from AMs contributes to LPS-induced ALI by inducing AEC pyroptosis through the targeting of Wnt9a to activate the Wnt signaling pathway. This study revealed that AMs and AECs interact in ALI, providing novel strategies for ALI treatment.

The Detoxification Effects of Melatonin on Aflatoxin-Caused Toxic Effects and Underlying Molecular Mechanisms

Aflatoxins (AFTs) are a form of mycotoxins mainly produced by Aspergillus flavus and Aspergillus parasiticus, which are common contaminants in various agricultural sources such as feed, milk, food, and grain crops. Aflatoxin B1 (AFB1) is the most toxic one among all AFTs. AFB1 undergoes bioactivation into AFB1-8,9-epoxide, then leads to diverse harmful effects such as neurotoxicity, carcinogenicity, hepatotoxicity, reproductive toxicity, nephrotoxicity, and immunotoxicity, with specific molecular mechanisms varying in different pathologies. The detoxification of AFB1 is of great importance for safeguarding the health of animals and humans and has increasingly attracted global attention. Recent research has shown that melatonin supplementation can effectively mitigate AFB1-induced multiple toxic effects. The protection mechanisms of melatonin involve the inhibition of oxidative stress, the upregulation of antioxidant enzyme activity, the reduction of mitochondrial dysfunction, the inactivation of the mitochondrial apoptotic pathway, the blockade of inflammatory responses, and the attenuation of cytochrome P450 enzymes' expression and activities. In summary, this review sheds new light on the potential role of melatonin as a potential detoxifying agent against AFB1. Further exploration of the precise molecular mechanisms and clinical efficacy of this promising treatment is urgently needed.

Bay-117082 treats sepsis by inhibiting neutrophil extracellular traps (NETs) formation through down-regulating NLRP3/N-GSDMD

During the inflammatory storm of sepsis, a significant quantity of neutrophil extracellular traps (NETs) are generated, which act as a double-edged sword and not only impede the invasion of foreign microorganisms but also exacerbate organ damage. This study provides evidence that NETs can cause damage to alveolar epithelial cells in vitro. The sepsis model developed in this study showed a significant increase in NETs in the bronchoalveolar lavage fluid (BALF). The development of NETs has been shown to increase the lung inflammatory response and aggravate injury to alveolar epithelial cells. Bay-117082, a well-known NF-κB suppressor, is used to modulate inflammation. This analysis revealed that Bay-117082 efficiently reduced total protein concentration, myeloperoxidase activity, and inflammatory cytokines in BALF. Moreover, Bay-117082 inhibited the formation of NETs, which in turn prevented the activation of the pore-forming protein gasdermin D (GSDMD). In summary, these results indicated that excessive NET production during sepsis exacerbated the onset and progression of acute lung injury (ALI). Therefore, Bay-117082 could serve as a novel therapeutic approach for ameliorating sepsis-associated ALI.

Embryo-Derived Cathepsin B Promotes Implantation and Decidualization by Activating Pyroptosis

Embryo implantation and decidualization are crucial for a successful pregnancy. How the inflammatory response is regulated during these processes is undefined. Pyroptosis is an inflammatory form of cell death mediated by gasdermin D (GSDMD). Through in vivo, cultured epithelial cells and organoids, it is shown that pyroptosis occurs in epithelial cells at the implantation site. Compared with those on day 4 of pseudopregnancy and delayed implantation, pyroptosis-related protein levels are significantly increased on day 4 of pregnancy and activated implantation, suggesting that blastocysts are involved in regulating pyroptosis. Blastocyst-derived cathepsin B (CTSB) is stimulated by preimplantation estradiol-17β and induces pyroptosis in epithelial cells. Pyroptosis-induced IL-18 secretion from epithelial cells activates a disintegrin and metalloprotease 12 (ADAM12) to process the epiregulin precursor into mature epiregulin. Epiregulin (EREG) enhances in vitro decidualization in mice. Pyroptosis-related proteins are detected in the mid-secretory human endometrium and are elevated in the recurrent implantation failure endometrium. Lipopolysaccharide treatment in pregnant mice causes implantation failure and increases pyroptosis-related protein levels. Therefore, the data suggest that modest pyroptosis is beneficial for embryo implantation and decidualization. Excessive pyroptosis can be harmful and lead to pregnancy failure.

Phillyrin prevents sepsis-induced acute lung injury through inhibiting the NLRP3/caspase-1/GSDMD-dependent pyroptosis signaling pathway

Acute lung injury (ALI) is a severe pulmonary disorder of sepsis with high clinical incidence and mortality. Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3)-cysteinyl aspartate specific proteinase 1-gasdermin D (GSDMD)-dependent pyroptosis of alveolar epithelial cells (AECs) has emerged as a crucial contributor to ALI during sepsis. Phillyrin (PHI), a natural lignan isolated from the traditional Chinese herbal medicine Forsythia suspensa, has been shown to have anti-inflammatory, antioxidant and antiviral properties. However, little is known about the protective role and potential mechanism of PHI in sepsis-induced ALI, and it is uncertain whether the protective effect of PHI in sepsis-induced ALI is connected to pyroptosis. This study aims to examine the preventive effects of PHI on sepsis-induced ALI via the inhibition of NLRP3/caspase-1/GSDMD-mediated pyroptosis in AECs. Our findings demonstrate that preadministration of PHI successfully reduces sepsis-induced pulmonary edema, systemic/pulmonary inflammation, and pulmonary histological damage in lung tissues, bronchoalveolar lavage fluid, and the serum of septic mice. Intriguingly, PHI preadministration suppresses sepsis-induced protein expressions of pyroptosis-specific markers, especially their active forms. In vitro assays show that PHI pretreatment also protects type II AECs (MLE-12) from lipopolysaccharide-induced pyroptosis by preventing the activation of the pyroptosis signaling pathway. The results from molecular docking and surface plasmon resonance reveal that PHI has a significant affinity for direct binding to the GSDMD protein, suggesting that GSDMD is a potential pharmacological target for PHI. In conclusion, PHI can prevent sepsis-triggered ALI by effectively suppressing the activation of the canonical pyroptosis signaling pathway and pyroptosis of AECs.

Inhibition of GBP1 alleviates pyroptosis of human pulmonary microvascular endothelial cells through STAT1/NLRP3/GSDMD pathway

Restoring and maintaining the function of endothelial cells is critical for acute respiratory distress syndrome (ARDS). Guanylate binding protein 1(GBP1) is proved to elevated in ARDS patients, but its role and mechanism remains unclear. The objective of this study is to investigate the internal mechanism of GBP1 in lung injury. Our study showed that when the LPS and IFN-γ induced human Pulmonary Microvascular Endothelial Cells (HPMECs) injury model was established, cell viability was significantly reduced, and the levels of GBP1 levels and inflammatory factors were significantly increased. When transfection with si-GBP1, low expression of GBP1 promoted cell proliferation and migration, and decreased the expression of downstream inflammatory factors. Furthermore, the inhibition of GBP1 significantly reduced the occurrence of cell pyroptosis and the expression of NLRP3 and STAT1. Our study indicated that GBP1 alleviates endothelial pyroptosis and inflammation through STAT1 / NLRP3/GSDMD signaling pathway, and GBP1 may be a new target in the treatment of lung injury in the future.

Role of Lipopolysaccharides in the Inflammation and Pyroptosis of Alveolar Epithelial Cells in Acute Lung Injury and Acute Respiratory Distress Syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a spectrum of common critical respiratory conditions characterized by damage and death of alveolar epithelial cells (AECs). Pyroptosis is a form of programmed cell death with inflammatory characteristics, and activation of pyroptosis markers has been observed in AECs of patients with ALI/ARDS. Lipopolysaccharides (LPS) possess strong pro-inflammatory effects and are a crucial pathological factor leading to ALI in patients and animals. In LPS-induced ALI models, AECs undergo pyroptosis. However, physiologically and pathologically relevant concentrations of LPS lead to minor effects on AEC cell viability and minimal induction of cytokine release in vitro and do not induce classical pyroptosis. Nevertheless, LPS can enter the cytoplasm directly and induce non-classical pyroptosis in AECs when assisted by extracellular vesicles from bacteria, HMGB1, and pathogens. In this review, we have explored the effects of LPS on AECs concerning inflammation, cell viability, and pyroptosis, analyzing key factors that influence LPS actions. Notably, we highlight the intricate response of AECs to LPS within the framework of ALI and ARDS, emphasizing the variable induction of pyroptosis. Despite the minimal effects of LPS on AEC viability and cytokine release in vitro, LPS can induce non-classical pyroptosis under specific conditions, presenting potential pathways for therapeutic intervention. Collectively, understanding these mechanisms is crucial for the development of targeted treatments that mitigate the inflammatory responses in ALI/ARDS, thereby enhancing patient outcomes in these severe respiratory conditions.

Mechanism of Action and Therapeutic Implications of Nrf2/HO-1 in Inflammatory Bowel Disease

Oxidative stress (OS) is a key factor in the generation of various pathophysiological conditions. Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) is a major transcriptional regulator of antioxidant reactions. Heme oxygenase-1 (HO-1), a gene regulated by Nrf2, is one of the most critical cytoprotective molecules. In recent years, Nrf2/HO-1 has received widespread attention as a major regulatory pathway for intracellular defense against oxidative stress. It is considered as a potential target for the treatment of inflammatory bowel disease (IBD). This review highlights the mechanism of action and therapeutic significance of Nrf2/HO-1 in IBD and IBD complications (intestinal fibrosis and colorectal cancer (CRC)), as well as the potential of phytochemicals targeting Nrf2/HO-1 in the treatment of IBD. The results suggest that the therapeutic effects of Nrf2/HO-1 on IBD mainly involve the following aspects: (1) Controlling of oxidative stress to reduce intestinal inflammation and injury; (2) Regulation of intestinal flora to repair the intestinal mucosal barrier; and (3) Prevention of ferroptosis in intestinal epithelial cells. However, due to the complex role of Nrf2/HO-1, a more nuanced understanding of the exact mechanisms involved in Nrf2/HO-1 is the way forward for the treatment of IBD in the future.

Aquaporin 1 aggravates lipopolysaccharide-induced macrophage polarization and pyroptosis

Acute respiratory infections (ARIs) are associated with high mortality and morbidity. Acute lung injury (ALI) is caused by the activation of immune cells during ARIs caused by viruses such as SARS-CoV-2. Aquaporin 1 (AQP1) is distributed in a variety of immune cells and is related to the occurrence of ALI, but the mechanism is not clear. A reference map of human single cells was used to identify macrophages in COVID-19 patients at the single-cell level. "FindMarkers" was used to analyze differentially expressed genes (DEGs), and "clusterProfiler" was used to analyze the functions of the DEGs. An M1 macrophage polarization model was established with lipopolysaccharide (LPS) in vitro, and the relationships among AQP1, pyroptosis and M1 polarization were examined by using an AQP1 inhibitor. Transcriptome sequencing and RT-qPCR were used to examine the molecular mechanism by which AQP1 regulates macrophage polarization and pyroptosis. Antigen presentation, M1 polarization, migration and phagocytosis are abnormal in SARS-CoV-2-infected macrophages, which is related to the high expression of AQP1. An M1 polarization model of macrophages was constructed in vitro, and an AQP1 inhibitor was used to examine whether AQP1 could promote M1 polarization and pyroptosis in response to LPS. Transcriptome and cell experiments showed that this effect was related to a decrease in chemokines caused by AQP1 deficiency. AQP1 participates in M1 polarization and pyroptosis in macrophages by increasing the levels of chemokines induced by LPS, which provides new insights for the diagnosis and treatment of ALI.

Targeting ferroptosis using Chinese herbal compounds to treat respiratory diseases

BACKGROUND

Respiratory diseases pose a grave threat to human life. Therefore, understanding their pathogenesis and therapeutic strategy is important. Ferroptosis is a novel type of iron-dependent programmed cell death, distinct from apoptosis, necroptosis, and autophagy, characterised by iron, reactive oxygen species, and lipid peroxide accumulation, as well as glutathione (GSH) depletion and GSH peroxidase 4 (GPX4) inactivation. A close association between ferroptosis and the onset and progression of respiratory diseases, including chronic obstructive pulmonary disease, acute lung injury, bronchial asthma, pulmonary fibrosis, and lung cancer, has been reported. Recent studies have shown that traditional Chinese medicine (TCM) compounds exhibit unique advantages in the treatment of respiratory diseases owing to their natural properties and potential efficacy. These compounds can effectively regulate ferroptosis by modulating several key signalling pathways such as system Xc- -GSH-GPX4, NCOA4-mediated ferritinophagy, Nrf2-GPX4, and Nrf2/HO-1, thus playing a positive role in improving respiratory diseases.

PURPOSE

This comprehensive review systematically outlines the regulatory role of ferroptosis in the onset and progression of respiratory diseases and provides evidence for treating respiratory diseases by targeting ferroptosis with TCM compounds. These insights aim to offer potential remedies for the clinical prevention and treatment of respiratory diseases.

STUDY DESIGN AND METHODS

We searched scientific databases PubMed, Web of Science, Scopus, and CNKI using keywords such as "ferroptosis","respiratory diseases","chronic obstructive pulmonary disease","bronchial asthma","acute lung injury","pulmonary fibrosis","lung cancer","traditional Chinese medicine","traditional Chinese medicine compound","monomer", and "natural product" to retrieve studies on the therapeutic potential of TCM compounds in ameliorating respiratory diseases by targeting ferroptosis. The retrieved data followed PRISMA criteria (preferred reporting items for systematic review).

RESULTS

TCM compounds possess unique advantages in treating respiratory diseases, stemming from their natural origins and proven clinical effectiveness. TCM compounds can exert therapeutic effects on respiratory diseases by regulating ferroptosis, which mainly involves modulation of pathways such as system Xc- -GSH-GPX4,NCOA4-mediated ferritinophagy, Nrf2-GPX4, and Nrf2/HO-1.

CONCLUSION

TCM compounds have demonstrated promising potential in improving respiratory diseases through the regulation of ferroptosis. The identification of specific TCM-related inducers and inhibitors of ferroptosis holds great significance in developing more effective strategies. However, current research remains confined to animal and cellular studies, emphasizing the imperative for further verifications through high-quality clinical data.

β-Hydroxybutyrate and melatonin suppress maladaptive UPR, excessive autophagy and pyroptosis in Aβ 1-42 and LPS-Induced SH-SY5Y cells

BACKGROUND

Alzheimer's disease is a neurological disease characterized by the build-up of amyloid beta peptide (Aβ) and lipopolysaccharide (LPS), which causes synapse dysfunction, cell death, and neuro-inflammation. A maladaptive unfolded protein response (UPR), excessive autophagy, and pyroptosis aggravate the disease. Melatonin (MEL) and hydroxybutyrate (BHB) have both shown promise in terms of decreasing Aβ pathology. The goal of this study was to see how BHB and MEL affected the UPR, autophagy, and pyroptosis pathways in Aβ1-42 and LPS-induced SH-SY5Y cells.

MATERIALS AND METHODS

Human neuroblastoma SH-SY5Y cells were treated with BHB, MEL, or a combination of the two after being exposed to A β1-42 and LPS. Cell viability was determined using the MTT test, and gene expression levels of UPR (ATF6, PERK, and CHOP), autophagy (Beclin-1, LC3II, P62, and Atg5), and pyroptosis-related markers (NLRP3, TXNIP, IL-1β, and NFκB1) were determined using quantitative Real-Time PCR (qRT-PCR). For statistical analysis, one-way ANOVA was employed, followed by Tukey's post hoc test.

RESULTS

BHB and MEL significantly increased SH-SY5Y cell viability in the presence of A β1-42 and LPS. Both compounds inhibited the expression of maladaptive UPR and autophagy-related genes, as well as inflammatory and pyroptotic markers caused by Aβ1-42 and LPS-induced SH-SY5Y cells.

CONCLUSION

BHB and MEL rescue neurons in A β1-42 and LPS-induced SH-SY5Y cells by reducing maladaptive UPR, excessive autophagy, and pyroptosis. More research is needed to fully comprehend the processes behind their beneficial effects and to discover their practical applications in the treatment of neurodegenerative disorders.

Acute Lung Injury and the NLRP3 Inflammasome

Acute lung injury (ALI) manifests through harm to the capillary endothelium and alveolar epithelial cells, arising from a multitude of factors, leading to scattered interstitial alterations, pulmonary edema, and subsequent acute hypoxic respiratory insufficiency. Acute lung injury (ALI), along with its more serious counterpart, acute respiratory distress syndrome (ARDS), carry a fatality rate that hovers around 30-40%. Its principal pathological characteristic lies in the unchecked inflammatory reaction. Currently, the main strategies for treating ALI are alleviation of inflammation and prevention of respiratory failure. Concerning the etiology of ALI, NLRP3 Inflammasome is essential to the body's innate immune response. The composition of this inflammasome complex includes NLRP3, the pyroptosis mediator ASC, and pro-caspase-1. Recent research has reported that the inflammatory response centered on NLRP3 inflammasomes plays a key part in inflammation in ALI, and may hence be a prospective candidate for therapeutic intervention. In the review, we present an overview of the ailment characteristics of acute lung injury along with the constitution and operation of the NLRP3 inflammasome within this framework. We also explore therapeutic strategies targeting the NLRP3 inflammasome to combat acute lung injury.

R. Almalki N, Asfour HZ, Al-Rabia MW, Alzain AA, Mohamed GA, Ibrahim SR. Protective effect of kaempferol glucoside against lipopolysaccharide-caused acute lung injury via targeting Nrf2/NF-κB/NLRP3/GSDMD: Integrating experimental and computational studies

The current study explored the protective potential of kaempferol 3-sophoroside-7-glucoside (KSG) against acute lung injury (ALI). Pre-treatment with KSG effectively secured mice from ALI and showed similar efficaciousness to dexamethasone. KSG markedly increased the survival rate and alleviated lung pathological lesions induced by lipopolysaccharide (LPS). Furthermore, KSG attenuated differential and total cell counts in BALF (bronchoalveolar lavage fluid) and MPO (myeloperoxidase) activity. KSG counteracted the NF-κB (nuclear factor-κB) activation and significantly ameliorated the downstream inflammatory cytokine, TNF-α (tumor necrosis factor-α). Simultaneously, KSG suppressed the over-expression of NLRP3 (NOD-like receptor protein 3), caspase-1, and pro-inflammatory cytokine interleukin IL-1β (interleukine-1β) and prohibited the elevation of the pyroptotic parameter GSDMD-N (N-terminal domain of gasdermin D) induced by LPS challenge. In addition, KSG significantly enhanced Nrf2 (nuclear-factor erythroid-2-related factor) and HO-1 (heme-oxygenase-1) expression. Meanwhile, KSG mitigated lipid peroxidative markers (malondialdehyde, protein carbonyl and 4-hydroxynonenal) and boosted endogenous antioxidants (superoxide dismutase/reduced glutathione/catalase) in lung tissue. In silico analyses revealed that KSG disrupts Keap1-Nrf2 protein-protein interactions by binding to the KEAP1 domain, consequently activating Nrf2. Specifically, molecular docking demonstrated superior binding affinity of KSG to KEAP1 compared to the reference inhibitor, with docking scores of -9.576 and -6.633 Kcal/mol, respectively. Additionally, the MM-GBSA binding free energy of KSG (-67.25 Kcal/mol) surpassed that of the reference inhibitor (-56.36 Kcal/mol). Furthermore, MD simulation analysis revealed that the KSG-KEAP1 complex exhibits substantial and stable binding interactions with various amino acids over a duration of 100 ns. These findings showed the protective anti-inflammatory and anti-oxidative modulatory efficiencies of KSG that effectively counteracted LPS-induced ALI and encouraged future research and clinical applications of KSG as a protective strategy for ALI.

Li-Hong Tang alleviates dextran sodium sulfate-induced colitis by regulating NRF2/HO-1 signaling pathway and gut microbiota

Introduction

Ulcerative colitis (UC) is marked by recurring inflammation. Existing treatments are ineffective and may have toxic side effects. Thus, new therapeutic agents are urgently needed. We studied the botanical formula "Li-Hong Tang (LHT)", which contains two main ingredients, Salvia plebeia R. Br and Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba. In this study, we aimed to identify the effects of LHT on UC and explore its potential mechanism.

Methods

LHT was analyzed using a mass spectrometer (MS). DSS at a dose of 2.5% was utilized to develop UC in mice. The administered groups received low, medium, and high dosages (0.32 g/kg, 0.64 g/kg, and 1.28 g/kg) of LHT and the positive medication, sulfasalazine (0.2 g/kg), respectively. Body weight, disease activity index (DAI) score, colon length, spleen index, serum myeloperoxidase (MPO), nitric oxide (NO), superoxide dismutase (SOD) and inflammatory factor concentrations were monitored. The expression of NRF2 and HO-1 in colonic tissues was evaluated by immunohistochemistry. 16S rDNA sequencing was employed to investigate alterations in the gut microbiota of the mice, aiming to elucidate the extent of LHT's impact.

Results

LHT may ameliorate DSS-induced colitis in mice by lowering inflammation, reducing oxidative stress, restoring the intestinal barrier, and influencing the NRF2/HO-1 pathway. Moreover, LHT treatment exhibited a regulatory effect on the gut microbiota, characterized by elevated levels of Patescibacteria, Verrucomicrobiota, Candidatus_Saccharimonas, Lactobacillus, and Ligilactobacillus levels while decreasing Oscillibacter and Colidextribacter levels. Further study indicated that MPO, NO, and inflammatory factors were positively correlated with Oscillibacter, Colidextribacter, Escherichia-Shigella, Anaerostines, and negatively with Lactobacillus, Clostridiales_unclassified, Candidatus_Saccharimonas, and Patescibacteria. Furthermore, colony network analysis revealed that Lactobacillus was negatively associated with Oscillibacter and Colidextribacter, whereas Oscillibacter was positively related to Colidextribacter.

Conclusion

LHT protects against DSS-induced mice by inhibiting the inflammatory response, oxidative stress, and mucosal injury. The protective role may involve regulating the NRF2/HO-1 signaling pathway and gut microbiota.

Melatonin alleviates septic ARDS by inhibiting NCOA4-mediated ferritinophagy in alveolar macrophages

Ferroptosis is a novel form of programmed cell death which can exacerbate lung injury in septic acute respiratory distress syndrome (ARDS). Alveolar macrophages, crucial innate immune cells, play a pivotal role in the pathogenesis of ARDS. Ferritinophagy is a process of ferritin degradation mediated by nuclear receptor coactivator 4 (NCOA4) which releases large amounts of iron ions thus promoting ferroptosis. Recent evidence revealed that inhibiting macrophage ferroptosis can effectively attenuate pulmonary inflammatory injury. Melatonin (MT), an endogenous neurohormone, has antioxidant and anti-inflammatory effects and can reduce septic ARDS. However, it is not clear whether MT's pulmonary protective effect is related to the inhibition of macrophage ferritinophagy. Our in vitro experiments demonstrated that MT decreased intracellular malondialdehyde (MDA), Fe2+, and lipid peroxidation levels, increased glutathione (GSH) levels and cell proliferation, and upregulated glutathione peroxidase 4 (GPX4) and ferritin heavy chain 1 (FTH1) protein levels in LPS-treated macrophages. Mechanistically, the antiferroptotic effect of MT on LPS-treated macrophages was significantly compromised by the overexpression of NCOA4. Our in vivo experiments revealed that MT alleviated the protein expression of NCOA4 and FTH1 in the alveolar macrophages of septic mice. Furthermore, MT improved lipid peroxidation and mitigated damage in alveolar macrophages and lung tissue, ultimately increasing the survival rates of septic mice. These findings indicate that MT can inhibit ferroptosis in an NCOA4-mediated ferritinophagy manner, thereby ameliorating septic ARDS.

miRNA-206-3p alleviates LPS-induced acute lung injury via inhibiting inflammation and pyroptosis through modulating TLR4/NF-κB/NLRP3 pathway

Acute lung injury (ALI) is life-threatening. MicroRNAs (miRNAs) are often abnormally expressed in inflammatory diseases and are closely associated with ALI. This study investigates whether miRNA-206-3p attenuates pyroptosis in ALI and elucidates the underlying molecular mechanisms. ALI mouse and cell models were established through lipopolysaccharide (LPS) treatment for 24 h. Subsequently, the models were evaluated based on ultrasonography, the lung tissue wet/dry (W/D) ratio, pathological section assessment, electron microscopy, and western blotting. Pyroptosis in RAW264.7 cells was then assessed via electron microscopy, immunofluorescence, and western blotting. Additionally, the regulatory relationship between miRNA-206-3p and the Toll-like receptor (TLR)4/nuclear factor (NF)-κB/Nod-like receptor protein-3 (NLRP3) pathway was verified. Finally, luciferase reporter gene and RNA pull-down assays were used to verify the targeting relationship between miRNA-206-3p and TLR4. miRNA206-3p levels are significantly decreased in the LPS-induced ALI model. Overexpression of miRNA-206-3p improves ALI, manifested as improved lung ultrasound, improved pathological changes of lung tissue, reduced W/D ratio of lung tissue, release of inflammatory factors in lung tissue, and reduced pyroptosis. Furthermore, overexpression of miRNA-206-3p contributed to reversing the ALI-promoting effect of LPS by hindering TLR4, myeloid differentiation primary response 88 (MyD88), NF-κB, and NLRP3 expression. In fact, miRNA-206-3p binds directly to TLR4. In conclusion, miRNA-206-3p alleviates LPS-induced ALI by inhibiting inflammation and pyroptosis via TLR4/NF-κB/NLRP3 pathway modulation.

Exposure to atrazine stimulates progesterone secretion and induces oxidative stress, inflammation, and apoptosis in the ovary of pseudopregnant rats

Atrazine (ATR) is one of the most commonly used herbicides worldwide. As an endocrine disruptor, it causes ovarian dysfunction, but the mechanism is unclear. We hypothesized that ATR could affect ovarian steroidogenesis, oxidative stress, inflammation, and apoptosis. In the current study, rats aged 28 days were treated with PMSG and HCG to obtain amounts of corpora lutea. Then, rats were injected with ATR (50 mg/kg/day) or saline (0.9%) for 7 days. Sera were collected to detect biochemical indices and progesterone (P4) level, ovaries were collected for antioxidant status, HE, qPCR, and WB analysis. Results showed that ATR exposure affected growth performance as well as serum TP, GLB, and ALB levels, increased serum P4 level and ovarian mRNA and protein levels of StAR, CYP11A1, and HSD3B. ATR treatment increased ovarian mRNA and protein levels of CREB but not PKA expression. ATR treatment increased ovarian mRNA abundances of Nrf-2 and Nqo1, MDA level, and decreased SOD, GST, and T-AOC levels. ATR exposure increased the mRNA abundances of pro-inflammatory cytokines including Tnf-α, Il-1β, Il-6, Il-18, and Inos. ATR exposure increased the mRNA and protein level of Caspase 3 and the ratio of BAX/BCL-2. In conclusion, NRF-2/NQO1 signaling pathway and CREB might be involved in the regulation of ATR in luteal steroidogenesis, oxidative stress, inflammation, and apoptosis in rat ovary.

Cuproptosis-Related Biomarkers and Characterization of Immune Infiltration in Sepsis

Introduction

Sepsis is a worldwide epidemic, with high morbidity and mortality. Cuproptosis is a form of cell death that is associated with a wide range of diseases. This study aimed to explore genes associated with cuproptosis in sepsis, construct predictive models and screen for potential targets.

Methods

The LASSO algorithm and SVM-RFE model has been analysed the expression of cuproptosis-related genes in sepsis and immune infiltration characteristics and identified the marker genes under a diagnostic model. Gene-drug networks, mRNA-miRNA networks and PPI networks were constructed to screen for potential biological targets. The expression of marker genes was validated based on the GSE57065 dataset. Consensus clustering method was used to classify sepsis samples.

Results

We found 381 genes associated with the development of sepsis and discovered significantly differentially expressed cuproptosis-related genes of 16 cell types in sepsis and immune infiltration with CD8/CD4 T cells being lower. NFE2L2, NLRP3, SLC31A1, DLD, DLAT, PDHB, MTF1, CDKN2A and DLST were identified as marker genes by the LASSO algorithm and the SVM-RFE model. AUC > 0.9 was constructed for PDHB and MTF1 alone respectively. The validation group data for PDHB (P=0.00099) and MTF1 (P=7.2e-14) were statistically significant. Consistent clustering analysis confirmed two subtypes. The C1 subtype may be more relevant to cellular metabolism and the C2 subtype has some relevance to immune molecules.The results of animal experiments showed that the gene expression was consistent with the bioinformatics analysis.

Discussion

Our study systematically explored the relationship between sepsis and cuproptosis and constructed a diagnostic model. And, several cuproptosis-related genes may interfere with the progression of sepsis through immune cell infiltration.

Bardoxolone methyl attenuates doxorubicin-induced cardiotoxicity by inhibiting the TXNIP-NLRP3 pathway through Nrf2 activation

Bardoxolone methyl, which triggers nuclear factor erythroid 2-related factor (Nrf2), has therapeutic effects against myocardial infarction, heart failure, and other diseases. Nrf2 can inhibit the activation of the thioredoxin-interacting protein (TXNIP)/NLR family pyrin domain-containing protein 3 (NLRP3) pathway. Doxorubicin is an anthracycline chemotherapeutic drug associated with cardiotoxicity, limiting its clinical use. In this study, we explored the specific mechanism of the Nrf2-TXNIP-NLRP3 pathway in doxorubicin-induced cardiotoxicity using bardoxolone methyl in animal and cell models. Using in vivo and in vitro experiments, we show that doxorubicin can induce oxidative stress and pyroptosis in the heart. Western blot and co-immunoprecipitation experimental results found that doxorubicin can reduce the interaction between TXNIP and TRX, increase the interaction between TXNIP and NLRP3, and activate the pyroptosis process. Bardoxolone methyl reduces the accumulation of reactive oxygen species in cardiomyocytes through the Nrf2 pathway, inhibits the interaction between TXNIP and NLRP3, and alleviates the progression of myocardial damage and cardiac fibrosis. Bardoxolone methyl lost its therapeutic effect when the expression of Nrf2 was decreased. Additionally, repressing the expression of TXNIP can inhibit the activation of NLRP3 and alleviate myocardial damage caused by doxorubicin. Collectively, our findings confirm that bardoxolone methyl alleviates doxorubicin-induced cardiotoxicity by activating Nrf2 and inhibiting the TXNIP-NLRP3 pathway.

Effect fraction of Bletilla striata (Thunb.) Reichb.f. alleviates LPS-induced acute lung injury by inhibiting p47phox/NOX2 and promoting the Nrf2/HO-1 signaling pathway

BACKGROUND & AIMS

The effect fraction of Bletilla striata (Thunb.) Reichb.f. (EFBS), a phenolic-rich extract, has significant protective effects on lipopolysaccharide (LPS)-induced acute lung injury (ALI), but its composition and molecular mechanisms are unclear. This study elucidated its chemical composition and possible protective mechanisms against LPS-induced ALI from an antioxidant perspective.

METHODS

EFBS was prepared by ethanol extraction, enriched by polyamide column chromatography, and characterized using ultra-performance liquid chromatography/time-of-flight mass spectrometry. The LPS-induced ALI model and the RAW264.7 model were used to evaluate the regulatory effects of EFBS on oxidative stress, and transcriptome analysis was performed to explore its possible molecular mechanism. Then, the pathway by which EFBS regulates oxidative stress was validated through inhibitor intervention, flow cytometry, quantitative PCR, western blotting, and immunofluorescence techniques.

RESULTS

A total of 22 compounds in EFBS were identified. The transcriptome analyses of RAW264.7 cells indicated that EFBS might reduce reactive oxygen species (ROS) production by inhibiting the p47phox/NADPH oxidase 2 (NOX2) pathway and upregulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. Both in vitro and in vivo data confirmed that EFBS significantly inhibited the expression and phosphorylation of p47phox protein, thereby weakening the p47phox/NOX2 pathway and reducing ROS production. EFBS significantly increased the expression of Nrf2 in primary peritoneal macrophages and lung tissue and promoted its nuclear translocation, dose-dependent increase in HO-1 levels, and enhancement of antioxidant activity. In vitro, both Nrf2 and HO-1 inhibitors significantly reduced the scavenging effects of EFBS on ROS, further confirming that EFBS exerts antioxidant effects at least partially by upregulating the Nrf2/HO-1 pathway.

CONCLUSIONS

EFBS contains abundant phenanthrenes and dibenzyl polyphenols, which can reduce ROS production by inhibiting the p47phox/NOX2 pathway and enhance ROS clearance activity by upregulating the Nrf2/HO-1 pathway, thereby exerting regulatory effects on oxidative stress and improving LPS-induced ALI.

LL-37 improves sepsis-induced acute lung injury by suppressing pyroptosis in alveolar epithelial cells

BACKGROUND

LL-37 (also known as murine CRAMP) is a human antimicrobial peptide that plays a crucial role in innate immune defence against sepsis through various mechanisms. However, its involvement in sepsis-induced lung injury remains unclear.

OBJECTIVES

This work investigates the impact of LL-37 on pyroptosis generated by LPS in alveolar epithelial cells. The research utilizes both in vivo and in vitro sepsis-associated acute lung injury (ALI) models to understand the underlying molecular pathways.

METHODS

In vivo, an acute lung injury model induced by sepsis was established by intratracheal administration of LPS in C57BL/6J mice, which were subsequently treated with low-dose CRAMP (recombinant murine cathelicidin, 2.5 mg.kg-1) and high-dose CRAMP (5.0 mg.kg-1). In vitro, pyroptosis was induced in a human alveolar epithelial cell line (A549) by stimulation with LPS and ATP. Treatment was carried out with recombinant human LL-37, or LL-37 was knocked out in A549 cells using small interfering RNA (siRNA). Subsequently, haematoxylin and eosin staining was performed to observe the histopathological changes in lung tissues in the control group and sepsis-induced lung injury group. TUNEL and PI staining were used to observe DNA fragmentation and pyroptosis in mouse lung tissues and cells in the different groups. An lactate dehydrogenase (LDH) assay was performed to measure the cell death rate. The expression levels of NLRP3, caspase1, caspase 1 p20, GSDMD, NT-GSDMD, and CRAMP were detected in mice and cells using Western blotting, qPCR, and immunohistochemistry. ELISA was used to assess the levels of interleukin (IL)-1β and IL-18 in mouse serum, bronchoalveolar lavage fluid (BALF) and lung tissue and cell culture supernatants.

RESULTS

The expression of NLRP3, caspase1 p20, NT-GSDMD, IL 18 and IL1β in the lung tissue of mice with septic lung injury was increased, which indicated activation of the canonical pyroptosis pathway and coincided with an increase in CRAMP expression. Treatment with recombinant CRAMP improved pyroptosis in mice with lung injury. In vitro, treatment with LPS and ATP upregulated these classic pyroptosis molecules, LL-37 knockdown exacerbated pyroptosis, and recombinant human LL-37 treatment alleviated pyroptosis in alveolar epithelial cells.

CONCLUSION

These findings indicate that LL-37 protects against septic lung injury by modulating the expression of classic pyroptotic pathway components, including NLRP3, caspase1, and GSDMD and downstream inflammatory factors in alveolar epithelial cells.

S100A9-/- alleviates LPS-induced acute lung injury by regulating M1 macrophage polarization and inhibiting pyroptosis via the TLR4/MyD88/NFκB signaling axis

Acute lung injury (ALI) is characterized by pulmonary diffusion abnormalities that may progress to multiple-organ failure in severe cases. There are limited effective treatments for ALI, which makes the search for new therapeutic avenues critically important. Macrophages play a pivotal role in the pathogenesis of ALI. The degree of macrophage polarization is closely related to the severity and prognosis of ALI, and S100A9 promotes M1 polarization of macrophages. The present study assessed the effects of S100A9-gene deficiency on macrophage polarization and acute lung injury. Our cohort study showed that plasma S100A8/A9 levels had significant diagnostic value for pediatric pneumonia and primarily correlated with monocyte-macrophages and neutrophils. We established a lipopolysaccharide (LPS)-induced mouse model of acute lung injury and demonstrated that knockout of the S100A9 gene mitigated inflammation by suppressing the secretion of pro-inflammatory cytokines, reducing the number of inflammatory cells in the bronchoalveolar lavage fluid, and inhibiting cell apoptosis, which ameliorated acute lung injury in mice. The in vitro and in vivo mechanistic studies demonstrated that S100A9-gene deficiency inhibited macrophage M1 polarization and reduced the levels of pulmonary macrophage chemotactic factors and inflammatory cytokines by suppressing the TLR4/MyD88/NF-κB signaling pathway and reversing the expression of the NLRP3 pyroptosis pathway, which reduced cell death. In conclusion, S100A9-gene deficiency alleviated LPS-induced acute lung injury by inhibiting macrophage M1 polarization and pyroptosis via the TLR4/MyD88/NFκB pathway, which suggests a potential therapeutic strategy for the treatment of ALI.

Melatonin improves the viability and ultrastructure of bovine oocyte-granulosa complexes of in vitro cultured early antral follicles

This study aims to investigate the effects of melatonin on follicular growth, viability and ultrastructure, as well as on the levels of mRNA for antioxidant enzymes, reactive oxygen species (ROS) and meiotic progression in oocytes from in vitro cultured bovine early antral follicles. To this end, isolated early antral follicles (500-600 μm) were cultured in TCM-199+ alone or supplemented with 10-6 , 10-7 or 10-8  M melatonin at 38.5°C with 5% CO2 for 8 days. Follicle diameters were evaluated at days 0, 4 and 8 of culture. At the end of culture, ultrastructure, chromatin configuration, viability (calcein-AM and ethidium homodimer-1 staining), and the levels of ROS and mRNA for catalase (CAT), superoxide dismutase (SOD) and peroxiredoxin 6 (PRDX6) and glutathione peroxidase (GPx) were investigated in oocyte-granulosa cell complexes (OGCs). The results showed that early antral follicles cultured with 10-6 and 10-8  M melatonin had a progressive and significant increase in their diameters throughout the culture period (p < .05). Additionally, oocytes from follicles cultured with 10-7 or 10-8  M melatonin had increased fluorescence for calcein-AM, while those cultured with 10-6 or 10-7  M had reduced fluorescence for ethidium homodimer-1. Different from follicles cultured in other treatments, those cultured with 10-8  M melatonin had well-preserved ultrastructure of oocyte and granulosa cells. Melatonin, however, did not influence the levels of ROS, the mitochondrial activity, oocyte meiotic resumption and expression mRNA for SOD, CAT, GPX1 and PRDX6. In conclusion, the presence of 10-8  M melatonin in culture medium improves viability and preserves the ultrastructure of oocyte and granulosa cells of early antral follicles cultured in vitro.

Netrin-1 mitigates acute lung injury by preventing the activation of the Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling

Acute lung injury (ALI) is one of the most common high-risk diseases associated with a high mortality rate and is still a challenge to treat effectively. Netrin-1 (NT-1) is a novel peptide with a wide range of biological functions, however, its effects on ALI have not been reported before. In this study, an ALI model was constructed using lipopolysaccharide (LPS) and treated with NT-1. Pulmonary function and lung wet to dry weight ratio (W/D) were detected. The expressions of pro-inflammatory cytokines and chemokines interleukin-8 (IL-8), interleukin-1β (IL-1β), and chemokine (C-X-C motif) ligand 2 (CXCL2) were measured using real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). We found that the levels of NT-1 were reduced in the LPS-induced ALI mice model. Administration of NT-1 improved histopathological changes of lung tissues and lung function in LPS-challenged ALI mice. We also report that NT-1 decreased Myeloperoxidase (MPO) activity and ameliorated pulmonary edema. Additionally, treatment with NT-1 reduced the levels of pro-inflammatory cytokines and chemokines such as IL-8, IL-1β, and CXCL2 in lung tissues of LPS-challenged ALI mice. Importantly, NT-1 reduced cell count in BALF and mitigated oxidative stress (OS) by reducing the levels of MDA and increasing the levels of GSH. Mechanistically, it is shown that NT-1 reduced the levels of Toll-like receptor 4 (TLR4) and prevented nuclear translocation of nuclear factor-κB (NF-κB) p65. Our findings indicate that NT-1 is a promising agent for the treatment of ALI through inhibiting TLR4/NF-κB signaling.

Self-Destructive Copper Carriers Induce Pyroptosis and Cuproptosis for Efficient Tumor Immunotherapy Against Dormant and Recurrent Tumors

Activating the strong immune system is a key initiative to counteract dormant tumors and prevent recurrence. Herein, self-destructive and multienzymatically active copper-quinone-GOx nanoparticles (abbreviated as CQG NPs) have been designed to induce harmonious and balanced pyroptosis and cuproptosis using the "Tai Chi mindset" to awaken the immune response for suppressing dormant and recurrent tumors. This cleverly designed material can disrupt the antioxidant defense mechanism of tumor cells by inhibiting the nuclear factor-erythroid 2-related factor 2 (NRF2)-quinone oxidoreductase 1 (NQO1) signaling pathway. Furthermore, combined with its excellent multienzyme activity, it activates NOD-like receptor protein 3 (NLRP3)-mediated pyroptosis. Meanwhile, cuproptosis can be triggered by copper ions released from the self-destructive disintegration of CQG NPs and the sensitivity of cancer cells to cuproptosis is enhanced through the depletion of endogenous copper chelators via the Michael addition reaction between glutathione (GSH) and quinone ligand, oxygen production from catalase-like reaction, and starvation-induced glucose deficiency. More importantly, CQG NPs-induced pyroptosis and cuproptosis can promote immunosuppressive tumor microenvironment (TME) remodeling, enhance the infiltration of immune cells into the tumor, and activate robust systemic immunity. Collectively, this study provides a new strategy to resist tumor dormancy, prevent tumor recurrence, and improve the clinical prognosis of tumors.

Bletilla striata polysaccharides protect against ARDS by modulating the NLRP3/caspase1/GSDMD and HMGB1/TLR4 signaling pathways to improve pulmonary alveolar macrophage pyroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Bletilla striata polysaccharides (BSP) extracted from the B. striata tuber, have been demonstrated to possess anti-inflammatory properties. However, their potential protective effect against ARDS and their role in regulating cell pyroptosis remained unexplored.

AIM OF THE STUDY

The aim of this study was to investigate the therapeutic effect of BSP in the alleviation of lipopolysaccharide (LPS)-induced ARDS, and to explore its mechanism of action.

METHODS

The effect of BSP was assessed by LPS injection into the intraperitoneal cavity in vivo; pathological changes of ARDS mice were gauged by immunohistochemical, hematoxylin and eosin staining, and immunofluorescence assays. MH-S cells were used to model the pyroptosis in vitro. Finally, the pyroptosis of alveolar macrophage was detected by western blots, qPCR, and flow cytometry for NLRP3/caspase1/GSDMD and HMGB1/TLR4 pathway-associated proteins and mRNA.

RESULTS

BSP could significantly increase the weight and survival rate of mice with ARDS, alleviate the cytokine storm in the lungs, and reduce lung damage in vivo. BSP inhibited the inflammation caused by LPS/Nigericin significantly in vitro. Compared with the control group, there was a remarkable surge in the incidence of pyroptosis observed in ARDS lung tissue and alveolar macrophages, whereas BSP significantly diminished the pyroptosis ratio. Besides, BSP reduced NLRP3/caspase1/GSDMD and HMGB1/TLR4 levels in ARDS lung tissue and MH-S cells.

CONCLUSIONS

These findings proved that BSP could improve LPS-induced ARDS via inhibiting pyroptosis, and this effect was mediated by NLRP3/caspase1/GSDMD and HMGB1/TLR4, suggesting a therapeutic potential of BSP as an anti-inflammatory agent for ARDS treatment.

Comprehensive analysis of m6A modification in lipopolysaccharide-induced acute lung injury in mice

BACKGROUND

N6-Methyladenosine (m6A) methylation is the most prevalent post-transcriptional modification in mRNA, and plays significant roles in various diseases. Nevertheless, the precise functions of m6A modification in the formation of ALI remain unclear. In this study we explore the transcriptome distribution of m6A methylation and its probable roles of in ALI.

METHODS

Lipopolysaccharide (LPS) was utilized to establish an ALI mouse model. Real-time qPCR, Western blotting and m6A dot blot were utilized to assess m6A methylation level and the expression of m6A methylation enzymes. MeRIP-Seq and RNA-seq were utilized to explore differential m6A modifications and differentially expressed genes in ALI mice. The hub genes and enriched pathways were assessed by Real-time qPCR and Western blotting.

RESULTS

Our findings showed that overall m6A methylation level was increased in ALI mice lung tissues, accompanied by lower levels of METTL3 and FTO. Notably, the protein expression of these methylases were different in various cells. There were 772 differently expressed m6A peaks in ALI as compared to the control group, with 316 being hypermethylated and 456 being hypomethylated. GO and KEGG analyses demonstrated these differentially methylated genes were associated with the calcium signaling pathway and cAMP signaling pathway. Furthermore, we identified 50 genes with distinct m6A peaks and mRNA expressions by combined analysis of MeRIP-Seq and RNA-Seq. KEGG analysis also demonstrated that these overlapped genes were closely associated with the calcium signaling pathway, cGMP-PKG signaling pathway, etc. Besides, Western blotting results demonstrated that the protein expression of Fibronectin leucine-rich transmembrane protein 3 (Flrt3) as well as the calcium signaling pathway and cGMP-PKG signaling pathway, increased significantly after ALI.

CONCLUSIONS

m6A modification was paramount in the pathogenesis of ALI, and provided a foundation for the further investigation in the prevention and treatment of ALI.

Signaling pathways and potential therapeutic targets in acute respiratory distress syndrome (ARDS)

Acute respiratory distress syndrome (ARDS) is a common condition associated with critically ill patients, characterized by bilateral chest radiographical opacities with refractory hypoxemia due to noncardiogenic pulmonary edema. Despite significant advances, the mortality of ARDS remains unacceptably high, and there are still no effective targeted pharmacotherapeutic agents. With the outbreak of coronavirus disease 19 worldwide, the mortality of ARDS has increased correspondingly. Comprehending the pathophysiology and the underlying molecular mechanisms of ARDS may thus be essential to developing effective therapeutic strategies and reducing mortality. To facilitate further understanding of its pathogenesis and exploring novel therapeutics, this review provides comprehensive information of ARDS from pathophysiology to molecular mechanisms and presents targeted therapeutics. We first describe the pathogenesis and pathophysiology of ARDS that involve dysregulated inflammation, alveolar-capillary barrier dysfunction, impaired alveolar fluid clearance and oxidative stress. Next, we summarize the molecular mechanisms and signaling pathways related to the above four aspects of ARDS pathophysiology, along with the latest research progress. Finally, we discuss the emerging therapeutic strategies that show exciting promise in ARDS, including several pharmacologic therapies, microRNA-based therapies and mesenchymal stromal cell therapies, highlighting the pathophysiological basis and the influences on signal transduction pathways for their use.

Advances on adaptive immune responses affected by infectious bursal disease virus in chicken

Infectious bursal disease (IBD) is an acute, highly infectious, and immunosuppressive disease caused by the infectious bursal disease virus (IBDV), which interferes with the immune system, causes hypoimmunity and seriously threatens the healthy development of the poultry industry. Adaptive immune response, an important defense line of host resistance to pathogen infection, is the host-specific immune response mainly mediated by T and B lymphocytes. As an important immunosuppressive pathogen in poultry, IBDV infection is closely related to the injury of the adaptive immune system. In this review, we focus on recent advances in adaptive immune response influenced by IBDV infection, especially the damage on immune organs, as well as the effect on humoral immune response and cellular immune response, hoping to provide a theoretical basis for further exploration of the molecular mechanism of immunosuppression induced by IBDV infection and the establishment of novel prevention and control measures for IBD.

PVB exerts anti-inflammatory effects by inhibiting the activation of MAPK and NF-κB signaling pathways and ROS generation in neutrophils

Pinaverium bromide (PVB) has been shown to protect mice against sepsis, which is predominantly attributed to PVB-mediated anti-inflammatory effects by inhibiting primed neutrophils to produce proinflammatory cytokines. However, the underlying mechanism(s) by which PVB affects neutrophils remains unknown. In this study, we report that treatment with PVB either before or after LPS stimulation attenuated IL-1β and TNF-α expression at both mRNA and protein levels in LPS-activated murine neutrophils. Further experiments revealed that PVB inhibited the phosphorylation of ERK, JNK, and IκBα in LPS-stimulated murine neutrophils. Moreover, PVB reduced reactive oxygen species (ROS) levels via regulating NADPH oxidase 2 (NOX2) activity, as represented by inhibiting p47phox translocation from the cytoplasm to the cellular membrane. Importantly, PVB significantly attenuated IL-1β, TNF-α, IL-6, CXCL1 production in both LPS-stimulated low density neutrophils (LDNs) and normal density neutrophils (NDNs) isolated from septic patients. Collectively, we demonstrated that PVB exerts anti-inflammatory effect by attenuating ROS generation and suppressing the activation of MAPK and NF-κB signaling pathways, suggesting that PVB may act as a potential therapeutic agent for sepsis by inhibiting neutrophil priming and activation.

Pyroptosis in septic lung injury: Interactions with other types of cell death

Sepsis is a life-threatening systemic inflammatory response syndrome caused by the host imbalanced response to infection. Lung injury is the most common complication of sepsis and one of the leading causes of patient death. Pyroptosis is a specific programmed cell death characterized by the release of inflammatory cytokines. Appropriate pyroptosis can reduce tissue damage and exert a protective effect against infection during sepsis. However, overactivated pyroptosis results in massive cell death, leading to septic shock, multiple organ dysfunction syndrome, and even an increased risk of secondary infection. Recent studies suggest that pyroptosis can interact with and cross-regulate other types of cell death programs to establish a complex network of cell death, which participates in the occurrence and development of septic lung injury. This review will focus on the interactions between pyroptosis and other types of cell death, including apoptosis, necroptosis, PANoptosis, NETosis, autophagy, and ferroptosis, to summarize the role of pyroptosis in sepsis-induced lung injury, and will discuss the potential therapeutic strategies of targeting pyroptosis during sepsis treatment.