Loganin alleviates sepsis-induced acute lung injury by regulating macrophage polarization and inhibiting NLRP3 inflammasome activation

Baicalin alleviates acute lung injury in vivo and in vitro

The aim of the present study was to evaluate the effects and mechanisms of Baicalin (BA) on acute lung injury (ALI). ALI model was established by lipopolysaccharide (LPS) and proteomics, immunoprecipitation and F-box/WD repeat containing protein 7 （FBXW7） knockout (KO) mice and FBXW7 silence mouse lung epithelial (MLE-12) cells were used to investigate the mechanisms of BA on acute lung injury ALI. The results showed that 218 differentially expressed proteins were identified in the lung tissue of ALI mice and FBXW7 was one of the changed most proteins and was significantly decreased in in the lung tissue of ALI mice. It was also found that FBXW7 had protective effects on ALI via inhibition of Absent in Melanoma 2 （AIM2） inflammasomes also found that BA mitigated ALI via FBXW7/AIM2 signal pathway. In conclusion, FBXW7 as a key marker was identified in ALI and has a protective effect on ALI and BA regulated FBXW7/AIM2 signal pathway to alleviate ALI. This study provided a new method for treating ALI.

Role and mechanisms of autophagy, ferroptosis, and pyroptosis in sepsis-induced acute lung injury

Sepsis-induced acute lung injury (ALI) is a major cause of death among patients with sepsis in intensive care units. By analyzing a model of sepsis-induced ALI using lipopolysaccharide (LPS) and cecal ligation and puncture (CLP), treatment methods and strategies to protect against ALI were discussed, which could provide an experimental basis for the clinical treatment of sepsis-induced ALI. Recent studies have found that an imbalance in autophagy, ferroptosis, and pyroptosis is a key mechanism that triggers sepsis-induced ALI, and regulating these death mechanisms can improve lung injuries caused by LPS or CLP. This article summarized and reviewed the mechanisms and regulatory networks of autophagy, ferroptosis, and pyroptosis and their important roles in the process of LPS/CLP-induced ALI in sepsis, discusses the possible targeted drugs of the above mechanisms and their effects, describes their dilemma and prospects, and provides new perspectives for the future treatment of sepsis-induced ALI.

A novel mechanism of resveratrol alleviates Toxoplasma gondii infection-induced pulmonary inflammation via inhibiting inflammasome activation

BACKGROUND

Infection by Toxoplasma gondii can lead to severe pneumonia, with current treatments being highly inadequate. The NLRP3 inflammasome is one member of the NOD-like receptor family with a pyrin domain, which is crucial in the innate immune defense against T. gondii. Research has shown that resveratrol (RSV) prevents lung damage caused by this infection by inhibiting the T. gondii-derived heat shock protein 70/TLR4/NF-κB pathway, thus reducing the macrophage-driven inflammatory response. However, it should be mentioned that the participation of NLRP3 inflammasome in the immune response to the lung injuries caused by T. gondii infections is not entirely clear.

PURPOSE

This study aims to clarify how RSV ameliorates lung damage triggered by Toxoplasma gondii infection, with a particular focus on the pathway involving TLR4, NF-κB, and the NLRP3 inflammasome.

METHODS

Both in vitro and in vivo models of infection were developed by employing the RH strain of T. gondii in BALB/c mice and RAW 264.7 macrophage cell lines. The action mechanism of RSV was explored using techniques such as molecular docking, surface plasmon resonance, ELISA, Western blot, co-immunoprecipitation, and immunofluorescence staining.

RESULTS

Findings indicate that the suppression of TLR4 or NF-κB impacts the levels of proteins associated with the NLRP3 inflammasome pathway. Additionally, a significant affinity for binding between RSV and NLRP3 was observed. Treatment with RSV led to a marked reduction in the activation and formation of the NLRP3 inflammasome within lung tissues and RAW 264.7 cells, alongside a decrease in IL-1β concentrations in the bronchoalveolar lavage fluid. These outcomes align with those seen when using the NLRP3 inhibitor CY-09. Moreover, the application of CY-09 prior to RSV negated the latter's anti-inflammatory properties.

CONCLUSION

Considering insights from previous research alongside the outcomes of the current investigation, it appears that the TLR4/NF-κB/NLRP3 signaling pathway emerges as a promising target for immunomodulation to alleviate lung injury from T. gondii infection. The evidence gathered in this study lays the groundwork for the continued exploration and potential future clinical deployment of RSV as a therapeutic agent with anti-Toxoplasma properties and the capability to modulate the inflammatory response.

Natural products act as game-changer potentially in treatment and management of sepsis-mediated inflammation: A clinical perspective

BACKGROUND

Sepsis, a life-threatening condition resulting from uncontrolled host responses to infection, poses a global health challenge with limited therapeutic options. Due to high heterogeneity, sepsis lacks specific therapeutic drugs. Additionally, there remains a significant gap in the clinical management of sepsis regarding personalized and precise medicine.

PURPOSE

This review critically examines the scientific landscape surrounding natural products in sepsis and sepsis-mediated inflammation, highlighting their clinical potential.

METHODS

Following the PRISMA guidelines, we retrieved articles from PubMed to explore potential natural products with therapeutic effects in sepsis-mediated inflammation.

RESULTS

434 relevant in vitro and in vivo studies were identified and screened. Ultimately, 55 studies were obtained as the supporting resources for the present review. We divided the 55 natural products into three categories: those influencing the synthesis of inflammatory factors, those affecting surface receptors and modulatory factors, and those influencing signaling pathways and the inflammatory cascade.

CONCLUSION

Natural products' potential as game-changers in sepsis-mediated inflammation management lies in their ability to modulate hallmarks in sepsis, including inflammation, immunity, and coagulopathy, which provides new therapeutic avenues that are readily accessible and capable of undergoing rapid clinical validation and deployment, offering a gift from nature to humanity. Innovative techniques like bioinformatics, metabolomics, and systems biology offer promising solutions to overcome these obstacles and facilitate the development of natural product-based therapeutics, holding promise for personalized and precise sepsis management and improving patient outcomes. However, standardization, bioavailability, and safety challenges arise during experimental validation and clinical trials of natural products.

Disulfiram Improves Fat Graft Retention by Modulating Macrophage Polarization With Inhibition of NLRP3 Inflammasome-Mediated Pyroptosis

BACKGROUND

Macrophage-mediated inflammatory response in the early post-grafting period restricts fat graft retention. Pyroptosis is a novel type of programmed cell death that extensively participates in inflammatory pathologies.

OBJECTIVES

This study sought to determine whether macrophage pyroptosis was activated during the inflammatory phase after fat grafting and to investigate the efficacy of a pyroptosis inhibitor, disulfiram (DSF), in fat graft retention.

METHODS

We established a C57BL/6 mice fat grafting model and then analyzed macrophage pyroptosis. DSF (50 mg/kg, every other day) was intraperitoneally injected starting 1 hour before fat grafting and continued for 14 days. An in vitro co-culture system was established in which mouse RAW264.7 macrophages were co-cultured with apoptotic adipocytes to further validate the findings of the in vivo studies and to explore the underlying mechanisms.

RESULTS

Here we reported that macrophage pyroptosis was activated in both fat grafts and in vitro co-culture models. DSF was found to be a potent pyroptosis inhibitor, promoting M2 macrophage polarization. In addition, DSF was demonstrated to enhance vascularization and graft retention.

CONCLUSIONS

Our results suggested that pyroptosis plays a crucial role in the inflammatory cascade within fat grafts. DSF, being a clinically available drug, could be translated into a clinically effective drug for improving fat graft survival by inhibiting macrophage pyroptosis, therefore inducing M2 macrophage polarization and promoting neovascularization.

Wogonin alleviates sepsis-induced acute lung injury by modulating macrophage polarization through the SIRT1-FOXO1 pathways

Sepsis-induced acute lung injury is a common and severe complication of sepsis, for which effective treatments are currently lacking. Previous studies have demonstrated the influence of wogonin in treating acute lung injury (ALI). However, its precise mechanism of action remains unclear. To delve deeper into the mechanisms underlying wogonin's impacts in sepsis-induced acute lung injury, we established a mouse sepsis model through cecal ligation and puncture and conducted further cell experiments using lipopolysaccharide-treated MH-S and MLE-12 cells to explore wogonin's potential mechanisms of action in treating ALI. Our results revealed that wogonin significantly increased the survival rate of mice, alleviated pulmonary pathological damage and inflammatory cell infiltration, and activated the SIRT1-FOXO1 pathway. Additionally, wogonin suppressed the release of pro-inflammatory factors by M1 macrophages and induced the activation of M2 anti-inflammatory factors. Further in vitro studies confirmed that wogonin effectively inhibited M1 macrophage polarization through the activation of the SIRT1-FOXO1 pathway, thereby mitigating lung pathological changes caused by ALI. In summary, our study demonstrated that wogonin regulated macrophage M1/M2 polarization through the activation of the SIRT1-FOXO1 pathway, thereby attenuating the inflammatory response and improving pulmonary pathological changes induced by sepsis-induced ALI. This discovery provided a solid mechanistic foundation for the therapeutic use of wogonin in sepsis-induced ALI, shedding new light on potential strategies for the treatment of sepsis-induced ALI.

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.

ARC@DPBNPs suppress LPS-induced acute lung injury via inhibiting macrophage pyroptosis and M1 polarization by ERK pathway in mice

AIM OF THE STUDY

Exploring the protective effect of ARC@DPBNP on lipopolysaccharides (LPS)-induced ALI and its underlying mechanism.

MATERIALS AND METHODS

ALI model was established by intransally administrating LPS (4 mg/kg) into C57BL/6 mice. The suppression effects of ALI was first compared between ARC (intragastric administrated, with doses ranging from 10 to 80 mg/kg) and ARC@BPBNPs (intratracheally administrated, with doses ranging from 1 to 4 mg/kg). Changes in lung histology post intratracheal intervention of 3 mg/kg ARC@DPBNPs were detected. The expression of pyrotosis pathway-related proteins in lungs as well as in RAW264.7 cells was detected by western blotting. The ASC expression in lung macrophages was examined using immune-fluorescent staining. The polarization of RAW264.7 cells and lung macrophages were detected by flow cytometry. The network pharmacology was constructed by Cytoscape, and the molecular docking was perfomed by AutoDock Vina.

RESULTS

Docking predicted the high affinity of ARC to MAPK1 (ERK2). HE staining showed that ARC@DPBNPs attenuated LPS-induced ALI at a remarkably lower dose than ARC. The improved histopathological changes, lung W/D weight ratio, and decreased of inflammatory factor levels in lung collectively demonstrated the alleviation effects of ARC@DPBNPs. Compared with the LPS group, ARC@DPBNPs down-regulated the ERK pathway, resulted in a suppression of the macrophage pyroptosis and M1 polarization. This suppression effects could be removed by the ERK activator Ro 67-7476.

CONCLUSION

ARC@DPBNPs attenuated ALI by suppressing LPS-induced macrophage pyroptosis and polarization, probably through down-regulation of the ERK pathway.

MicroRNA-1258 suppresses oxidative stress and inflammation in septic acute lung injury through the Pknox1-regulated TGF-β1/SMAD3 cascade

AIM

The study was to clarify the mechanism of miR-1258 targeting Prep1 (pKnox1) to control Transforming Growth Factor β1 (TGF-β1)/SMAD3 pathway in septic Acute Lung Injury (ALI)-induced oxidative stress and inflammation.

METHODS

BEAS-2B cells and C57BL/6 mice were used to make in vitro and in vivo septic ALI models, respectively. miR-1258 expression was checked by RT-qPCR. After transfection in the in vitro experimental model, inflammation, oxidative stress, viability, and apoptosis were observed through ELISA, MTT, and flow cytometry.

RESULTS

In the in vivo model after miR-1258 overexpression treatment, inflammation, oxidative stress, and lung injury were further investigated. The targeting relationship between miR-1258 and Pknox1 was tested. Low miR-1258 was expressed in septic ALI patients, LPS-treated BEAS-2B cells, and mice. Upregulated miR-1258 prevented inflammation, oxidative stress, and apoptosis but enhanced the viability of LPS-treated BEAS-2B cells. The impact of upregulated miR-1258 on LPS-treated BEAS-2B cells was mitigated by inhibiting Pknox1 expression. MiR-1258 overexpression had the alleviating effects on inflammation, oxidative stress, and lung injury of LPS-injured mice through suppressing Pknox1 expression and TGF-β1/SMAD3 cascade activation.

CONCLUSIONS

The study concludes that miR-1258 suppresses oxidative stress and inflammation in septic ALI through the Pknox1-regulated TGF-β1/SMAD3 cascade.

Mechanisms of Sepsis-Induced Acute Lung Injury and Advancements of Natural Small Molecules in Its Treatment

Sepsis-induced acute lung injury (ALI), characterized by widespread lung dysfunction, is associated with significant morbidity and mortality due to the lack of effective pharmacological treatments available clinically. Small-molecule compounds derived from natural products represent an innovative source and have demonstrated therapeutic potential against sepsis-induced ALI. These natural small molecules may provide a promising alternative treatment option for sepsis-induced ALI. This review aims to summarize the pathogenesis of sepsis and potential therapeutic targets. It assembles critical updates (from 2014 to 2024) on natural small molecules with therapeutic potential against sepsis-induced ALI, detailing their sources, structures, effects, and mechanisms of action.

Phospholipid transfer protein ameliorates sepsis-induced cardiac dysfunction through NLRP3 inflammasome inhibition

Cardiomyocyte pyroptosis is a primary contributor to sepsis-induced cardiac dysfunction (SICD). Recombinant phospholipid transfer protein (PLTP) have been demonstrated to possess anti-inflammatory and antiseptic properties. However, the effect of PLTP on SICD remains unknown. In this study, we established the in vivo and in vitro sepsis model with the recombinant PLTP treatment. The survival rates of mice, mouse cardiac function, cell viability, the protein level of proinflammatory cytokine, and lactate dehydrogenase level were evaluated. The cardiomyocyte pyroptotic changes were observed. The distribution of PLTP and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) in mouse myocardial tissue and expression of PLTP, apoptosis associated speck like protein containing a CARD (ASC), NLRP3, caspase-1, interleukin (IL)-1β, and Gasdermin D (GSDMD) were detected. PLTP ameliorated the cecal ligation and puncture-induced mouse survival rate decrease and cardiac dysfunction, inhibited the IL-1β, IL-18, and tumor necrosis factor (TNF)-α release, and blocked the NLRP3 inflammasome/GSDMD signaling pathway in septic mice. In vitro, PLTP reversed the lipopolysaccharide-induced cardiomyocyte pyroptosis, expression of IL-1β, IL-6, TNF-α, and activation of the NLRP3 inflammasome/GSDMD signal pathway. Moreover, PLTP could bind to NLRP3 and negatively regulate the activity of the NLRP3 inflammasome/GSDMD signal pathway. This study demonstrated that PLTP can ameliorate SICD by inhibiting inflammatory responses and cardiomyocyte pyroptosis by blocking the activation of the NLRP3 inflammasome/GSDMD signaling pathway.

GTS-21 attenuates ACE/ACE2 ratio and glycocalyx shedding in lipopolysaccharide-induced acute lung injury by targeting macrophage polarization derived ADAM-17

Acute lung injury (ALI) has received considerable attention in intensive care owing to its high mortality rate. It has been demonstrated that the selective alpha7 nicotinic acetylcholine receptor agonist Gainesville Tokushima scientists (GTS)-21 is promising for treating ALI caused by lipopolysaccharides (LPS). However, the precise underlying mechanism remains unknown. This study aimed to investigate the potential efficacy of GTS-21 in the treatment of ALI. We developed mouse models of ALI and alveolar epithelial type II cells (AT2s) injury following treatment with LPS and different polarized macrophage supernatants, respectively. Pathological changes, pulmonary edema, and lung compliance were assessed. Inflammatory cells count, protein content, and pro-inflammatory cytokine levels were analysed in the bronchoalveolar lavage fluid. The expression of angiotensin-converting enzyme (ACE), ACE2, syndecan-1 (SDC-1), heparan sulphate (HS), heparanase (HPA), exostosin (EXT)-1, and NF-κB were tested in lung tissues and cells. GTS-21-induced changes in macrophage polarization were verified in vivo and in vitro. Polarized macrophage supernatants with or without recombination a disintegrin and metalloproteinase-17 (ADAM-17) and small interfering (si)RNA ADAM-17 were used to verify the role of ADAM-17 in AT2 injury. By reducing pathological alterations, lung permeability, inflammatory response, ACE/ACE2 ratio, and glycocalyx shedding, as well as by downregulating the HPA and NF-κB pathways and upregulating EXT1 expression in vivo, GTS-21 significantly diminished LPS-induced ALI compared to that of the LPS group. GTS-21 significantly attenuated macrophage M1 polarization and augmented M2 polarization in vitro and in vivo. The destructive effects of M1 polarization supernatant can be inhibited by GTS-21 and siRNA ADAM-17. GTS-21 exerted a protective effect against LPS-induced ALI, which was reversed by recombinant ADAM-17. Collectively, GTS-21 alleviates LPS-induced ALI by attenuating AT2s ACE/ACE2 ratio and glycocalyx shedding through the inhibition of macrophage M1 polarization derived ADAM-17.

Veronica linariifolia subsp. dilatata ameliorates LPS-induced acute lung injury by attenuating endothelial cell barrier dysfunction via EGFR/Akt/ZO-1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The dried aerial parts of Veronica linariifolia subsp. dilatata (Nakai & Kitag.) D.Y.Hong named Shui Man Jing (SMJ) is a traditional Chinese medicine with a long history of clinical use in the treatment of chronic bronchitis and coughing up blood, however, its role on acute lung injury (ALI) has not been revealed yet.

AIM OF THE STUDY

To assess the efficiency of SMJ on ALI and to investigate whether it inhibited endothelial barrier dysfunction by regulating the EGFR/Akt/ZO-1 pathway to alleviate ALI in vivo and in vitro based on the result of network pharmacology.

MATERIALS AND METHODS

An in vivo model of ALI was established using inhalation of atomized lipopolysaccharide (LPS), and the effects of SMJ on ALI were evaluated through histopathological examination and inflammatory cytokines, lung histology and edema, vascular and alveolar barrier disruption. Network pharmacology was applied to predict the mechanism of SMJ in the treatment of ALI. The crucial targets were validated by RT-PCR, Western Blotting, molecular docking, immunohistochemistry and immunofluorescence methods in vivo and in virto.

RESULTS

Administration of SMJ protected mice against LPS-induced ALI, including ameliorating the histological alterations in the lung tissues, and decreasing lung edema, protein content of bronchoalveolar lavage fluid, infiltration of inflammatory cell and secretion of cytokines. SMJ exerted protective effects in ALI by inhibiting endothelial barrier dysfunction in mice and bEnd.3 cell. SMJ relieved endothelial barrier dysfunction induced by LPS through upregulating the EGFR expression. SMJ also increased the phosphorylation of Akt, and ZO-1 expression both in vivo and in vitro.

CONCLUSION

SMJ attenuates vascular endothelial barrier dysfunction for LPS-induced ALI via EGFR/Akt/ZO-1 pathway, and is a promising novel therapeutic candidate for ALI.

Isoegomaketone alleviates inflammatory response and oxidative stress in sepsis lung injury

BACKGROUND

Sepsis is a life-threatening condition characterized by acute organ dysfunction, which frequently leads to acute lung injury (ALI) in approximately 40% of cases. Isoegomaketone (IK) is a constituent of essential oil found in P. frutescens, known for its diverse biological properties, including anti-inflammatory and antitumor effects. However, the regulatory impact of IK on ALI in the context of sepsis remains poorly understood.

METHODS

Pathological alterations in lung tissues were assessed using hematoxylin and eosin staining. Enumeration of total leukocytes and neutrophils in bronchoalveolar lavage fluid (BALF) was performed using a hematocytometer, while the levels of interleukin (IL)-6, IL-1β, IL-10, and IL-17 in BALF were quantified using enzyme-linked immunosorbent serological assay. In addition, the levels of malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), and glutathione (GSH) in lung tissues were assessed using respective commercial kits; cell apoptosis was evaluated using the terminal deoxynucleotide transferase--mediated dUTP nick end-labeling assay, and protein expressions were determined through Western blot analysis.

RESULTS

Our findings revealed that cecal ligation and puncture (CLP) treatment in mice induced severe lung injury, characterized by increased lung injury scores, significant bleeding, neutrophil infiltration, and alveolar edema. However, treatment with IK at a dose of 10 mg/kg ameliorated CLP-induced lung injury, while IK dose of 5 mg/kg showed no significant effect. Additionally, IK treatment at 10 mg/kg reduced CLP-induced inflammation by decreasing levels of IL-6, IL-1β, IL-10, and IL-17. Furthermore, IK at 10 mg/kg attenuated CLP-induced oxidative stress by modulating levels of MDA, MPO, SOD, and GSH. Moreover, IK treatment with a dose of 10 mg/kg activated the nuclear factor erythroid 2-related factor 2-heme oxygenase-1 (Nrf2-HO-1) pathway by enhancing the protein expressions of Nrf2 and HO-1.

CONCLUSION

This study demonstrates that IK could mitigate the inflammatory response and oxidative stress associated with sepsis-induced ALI, supporting IK as a promising therapeutic agent for the treatment of sepsis-associated ALI.

Role of ATF3 triggering M2 macrophage polarization to protect against the inflammatory injury of sepsis through ILF3/NEAT1 axis

BACKGROUND

Sepsis is a systemic inflammatory response which is frequently associated with acute lung injury (ALI). Activating transcription factor 3 (ATF3) promotes M2 polarization, however, the biological effects of ATF3 on macrophage polarization in sepsis remain undefined.

METHODS

LPS-stimulated macrophages and a mouse model of cecal ligation and puncture (CLP)-induced sepsis were generated as in vitro and in vivo models, respectively. qRT-PCR and western blot were used to detect the expression of ATF3, ILF3, NEAT1 and other markers. The phenotypes of macrophages were monitored by flow cytometry, and cytokine secretion was measured by ELISA assay. The association between ILF3 and NEAT1 was validated by RIP and RNA pull-down assays. RNA stability assay was employed to assess NEAT1 stability. Bioinformatic analysis, luciferase reporter and ChIP assays were used to study the interaction between ATF3 and ILF3 promoter. Histological changes of lung tissues were assessed by H&E and IHC analysis. Apoptosis in lungs was monitored by TUNEL assay.

RESULTS

ATF3 was downregulated, but ILF3 and NEAT1 were upregulated in PBMCs of septic patients, as well as in LPS-stimulated RAW264.7 cells. Overexpression of ATF3 or silencing of ILF3 promoted M2 polarization of RAW264.7 cells via regulating NEAT1. Mechanistically, ILF3 was required for the stabilization of NEAT1 through direct interaction, and ATF3 was a transcriptional repressor of ILF3. ATF3 facilitated M2 polarization in LPS-stimulated macrophages and CLP-induced septic lung injury via ILF3/NEAT1 axis.

CONCLUSION

ATF3 triggers M2 macrophage polarization to protect against the inflammatory injury of sepsis through ILF3/NEAT1 axis.

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.

ASTRAGALOSIDE Ⅳ MODULATES GUT MACROPHAGES M1/M2 POLARIZATION BY RESHAPING GUT MICROBIOTA AND SHORT CHAIN FATTY ACIDS IN SEPSIS

ABSTRACT

M1 macrophage-mediated inflammation is critical in sepsis. We previously found the protective role of astragaloside intravenous (AS-IV) in sepsis-associated gut impairment, whose specific mechanism remains unknown. Gut microbiota modulates gut homeostatic balance to avoid excessive inflammation. Here, we aimed to investigate effects of AS-IV on gut macrophages polarization and potential roles of gut microbiota and short chain fatty acids (SCFAs) in septic gut damage. Mice were pretreated by AS-IV gavage for 7 days before cecal ligation and puncture. M1 polarization of gut lamina propria macrophages (LpMs) was promoted by cecal ligation and puncture, accompanied by abnormal cytokines release and intestinal barrier dysfunction. NLRP3 inflammasome was activated in M1 LpMs. 16S rRNA sequencing demonstrated gut microbiota imbalance. The levels of acetate, propionate, and butyrate in fecal samples decreased. Notably, AS-IV reversed LpMs M1/M2 polarization, lightened gut inflammation and barrier injury, reduced NLRP3 inflammasome expression in LpMs, restored the diversity of gut microbiome, and increased butyrate levels. Similarly, these benefits were mimicked by fecal microbiota transplantation or exogenous butyrate supplementation. In Caco-2 and THP-1 cocultured model, LPS and interferon γ caused THP-1 M1 polarization, Caco-2 barrier impairment, abnormal cytokines release, and high NLRP3 inflammasome expression in THP-1 cells, all of which were mitigated by butyrate administration. However, these protective effects of butyrate were abrogated by NLRP3 gene overexpression in THP-1. In conclusion, AS-IV can ameliorate sepsis-induced gut inflammation and barrier dysfunction by modulating M1/M2 polarization of gut macrophages, whose underlying mechanism may be restoring gut microbiome and SCFA to restrain NLRP3 inflammasome activation.

Dihydroquercetin (DHQ) ameliorates LPS-induced acute lung injury by regulating macrophage M2 polarization through IRF4/miR-132-3p/FBXW7 axis

BACKGROUND

Acute lung injury (ALI) is a common complication of sepsis. Dihydroquercetin (DHQ) has been found to attenuate lipopolysaccharide (LPS)-induced inflammation. However, the effect of DHQ on LPS-challenged ALI remains unclear.

METHODS

Pulmonary HE and TUNEL staining and lung wet/dry ratio were detected in LPS-treated Balb/c mice. IL-1β, IL-6 and TNF-α levels were determined utilizing ELISA assay. RAW264.7 cell apoptosis and macrophage markers (CD86, CD206) were tested using flow cytometry. TC-1 viability was analyzed by MTT assay. Western blot measured protein expression of macrophage markers. Interactions of miR-132-3p, IRF4 and FBXW7 were explored utilizing ChIP, RNA pull-down and dual luciferase reporter assays.

RESULTS

DHQ alleviated histopathological change, pulmonary edema and apoptosis in LPS-treated mice. DHQ affected LPS-induced M2 macrophage polarization and TC-1 cell injury-related indicators, such as decreased cell activity, decreased LDH levels, and increased apoptosis. LPS inhibited IRF4 and miR-132-3p expression, activated Notch pathway and increased FBXW7 level, which were overturned by DHQ. IRF4 transcriptionally activated miR-132-3p expression. FBXW7 was a downstream target of miR-132-3p.

CONCLUSION

DHQ alleviated LPS-induced lung injury through promoting macrophage M2 polarization via IRF4/miR-132-3p/FBXW7 axis, which provides a new therapeutic strategy for ALI.

The Distinct Properties of Polysaccharide Nanoparticles Tune Immune Responses against mRNA Antigen via Stimulator of Interferon Genes-Mediated Autophagy and Inflammasome

mRNA antigens require powerful nanocarriers for efficient delivery, as well as immunomodulators for controlling their excessive immunogenicity. While lipid nanoparticles (LNPs) used in mRNA vaccines exhibited systemic toxicity, there is an urgent need for developing potential nanoparticles with strong immunoenhancing effects for mRNA antigens. Although natural polysaccharides as adjuvants assisted various types of antigens in triggering potent immune responses, they have been rarely investigated in mRNA vaccines. Here, we constructed four polysaccharide nanoparticles with different molecular weights (MWs) to deliver and protect mRNA antigens, and boosted antigen cross-presentation, DC maturation, CD4+/CD8+T cell responses and humoral immune responses. Importantly, the immunoenhancing capacities of polysaccharide nanoparticles were highly dependent on their MW properties. CS NPs with high MW initiated stimulator of interferon genes (STING)-mediated autophagy and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome signaling, consequently possessing superior mRNA antigen-specific immune responses in vitro and in vivo. In contrast, CS NPs with low MWs induced NLRP3 signaling without STING or autophagy activation, which failed to induce robust immune responses. Therefore, it uncovered the MW-dependent immunoenhancing effects and mechanism of polysaccharide nanoparticles, providing a platform for designing potential nanosized polysaccharide immunomodulators for mRNA vaccines.

Loganin alleviates myocardial ischemia-reperfusion injury through GLP-1R/NLRP3-mediated pyroptosis pathway

Myocardial ischemia-reperfusion (I/R) injury is one of main pathological manifestations of cardiovascular outcomes related to NLRP3 inflammasome-mediated pyroptosis pathway. Loganin is an iridoid glycoside extracted from traditional Chinese medicines, which has multiple activities. However, the roles and mechanism of loganin in myocardial I/R injury remain largely unknown. The models of myocardial I/R injury were established using I/R-treated rats or OGD/R-treated H9C2 cardiomyocytes. Myocardial damage was assessed by TTC and hematoxylin-eosin staining. Pyroptosis-related marker levels were detected by immunohistochemistry, immunofluorescence and western blotting assays. Cell proliferation was examined via EdU assay. Cell apoptosis was investigated by LDH release and flow cytometry. The integrity of cell membrane was analyzed via Dil staining. GLP-1R and NLRP3 levels were detected by immunofluorescence and western blotting assays. Our results showed that loganin suppressed I/R-induced myocardial damage in rats by reducing myocardial infarct, injury and pyroptosis. In addition, loganin attenuated OGD/R-induced cardiomyocyte apoptosis through increasing cell proliferation and reducing LDH release and apoptotic rate. Loganin also mitigated OGD/R-induced cardiomyocyte pyroptosis by reducing cell membrane damage and levels of cleaved caspase-1, IL-1β and IL-18. Furthermore, loganin repressed GLP-1R/NLRP3 pathway activation in OGD/R-treated H9C2 cardiomyocytes by enhancing GLP-1R expression and decreasing NLRP3 level. GLP-1R/NLRP3 activation by GLP-1R inhibition or NLRP3 overexpression reversed the suppressive effects of loganin on OGD/R-induced cardiomyocyte pyroptosis. These data indicated that loganin prevented OGD/R-induced proliferation inhibition, apoptosis and pyroptosis in OGD/R-treated cardiomyocytes by inhibiting GLP-1R/NLRP3 activity, indicating the therapeutic potential of loganin in myocardial I/R injury.

Mechanism of exosomes from adipose-derived mesenchymal stem cells on sepsis-induced acute lung injury by promoting TGF-β secretion in macrophages

OBJECTIVE

Acute lung injury (ALI) caused by sepsis is a life-threatening condition characterized by uncontrollable lung inflammation. The current study sought to investigate the mechanism of adipose-derived mesenchymal stem cell-derived exosomes (ADMSC-Exos) in attenuating sepsis-induced ALI through TGF-β secretion in macrophages.

METHODS

Adipose-derived mesenchymal stem cell-derived exosomes (ADMSC-Exos) were extracted from ADMSCs and identified. Septic ALI mouse models were established via cecal ligation and puncture (CLP), followed by administration of ADMSC-Exos or sh-TGF-β lentiviral vector. Mouse macrophages (cell line RAW 264.7) were treated with lipopolysaccharide (LPS), co-cultured with Exos and splenic T cells, and transfected with TGF-β siRNA. The lung injury of CLP mice was evaluated, and levels of inflammatory indicators and macrophage markers were measured. The localization of macrophage markers and TGF-β was determined, and the level of TGF-β in lung tissues was measured. The effect of TGF-β knockdown on sepsis-induced ALI in CLP mice was evaluated, and the percentages of CD4+CD25+Foxp3+ Tregs in mononuclear cells/macrophages and Foxp3 levels in lung tissues/co-cultured splenic T cells were examined.

RESULTS

ADMSC-Exos were found to alleviate sepsis-induced ALI, inhibit inflammatory responses, and induce macrophages to secrete TGF-β in CLP mice. TGF-β silencing reversed the alleviating effect of ADMSC-Exos on sepsis-induced ALI. ADMSC-Exos also increased the number of Tregs in the spleen of CLP mice and promoted M2 polarization and TGF-β secretion in LPS-induced macrophages. After knockdown of TGF-β in macrophages in the co-culture system, the number of Tregs decreased, suggesting that ADMSC-Exos increased the Treg number by promoting macrophages to secrete TGF-β.

CONCLUSION

Our findings suggest ADMSC-Exos can effectively alleviate sepsis-induced ALI in CLP mice by promoting TGF-β secretion in macrophages.

Natural products for treating cytokine storm-related diseases: Therapeutic effects and mechanisms

BACKGROUND

A cytokine storm (CS) is a rapidly occurring, complex, and highly lethal systemic acute inflammatory response induced by pathogens and other factors. Currently, no clinical therapeutic drugs are available with a significant effect and minimal side effects. Given the pathogenesis of CS, natural products have become important resources for bioactive agents in the discovery of anti-CS drugs.

PURPOSE

This study aimed to provide guidance for preventing and treating CS-related diseases by reviewing the natural products identified to inhibit CS in recent years.

METHODS

A comprehensive literature review was conducted on CS and natural products, utilizing databases such as PubMed and Web of Science. The quality of the studies was evaluated and summarized for further analysis.

RESULTS

This study summarized more than 30 types of natural products, including 9 classes of flavonoids, phenols, and terpenoids, among others. In vivo and in vitro experiments demonstrated that these natural products could effectively inhibit CS via nuclear factor kappa-B, mitogen-activated protein kinase, and Mammalian target of rapamycin (mTOR) signaling pathways. Moreover, the enzyme inhibition assays revealed that more than 20 chemical components had the potential to inhibit ACE2, 3CL-protease, and papain-like protease activity. The experimental results were obtained using advanced technologies such as biochips and omics.

CONCLUSIONS

Various natural compounds in traditional Chinese medicine (TCM) extracts could directly or indirectly inhibit CS occurrence, potentially serving as effective drugs for treating CS-related diseases. This study may guide further exploration of the therapeutic effects and biochemical mechanisms of natural products on CS.

Cyasterone ameliorates sepsis-related acute lung injury via AKT (Ser473)/GSK3β (Ser9)/Nrf2 pathway

BACKGROUND

Acute lung injury (ALI) is a severe disease that can lead to acute respiratory distress syndrome (ARDS), characterized by intractable hypoxemia, poor lung compliance, and respiratory failure, severely affecting patients' quality of life. The pathogenesis of ALI has not been fully elucidated yet, and sepsis is an important cause of ALI. Among the organ injuries caused by sepsis, the lungs are the earliest damaged ones. Radix cyathulae is reported to have analgesic, anti-inflammatory, and anti-aging effects. Cyasterone is extracted from Radix cyathulae. However, it is not known whether cyasterone has protective effects for ALI. This study aims to investigate the effect of cyasterone on sepsis-related ALI and its mechanism.

METHODS

We used the cecal ligation peferation (CLP) method to establish a mouse sepsis model, and cyasterone was given intraperitoneally on days 1-3 to observe its preventive effect on sepsis-related acute lung injury. Primary murine peritoneal macrophages were used to investigate the molecular mechanism of cyasterone in vitro.

RESULTS

Cyasterone pretreatment inhibits pro-inflammatory cytokine production, NLRP3 inflammasome activation, and oxidative stress in vivo and in vitro. In addition, cyasterone attenuates sepsis-induced ALI by activating nuclear factor erythroid2-related factor (Nrf2), which may be associated with AKT(Ser473)/GSK3β(Ser9) pathway activation.

CONCLUSIONS

Cyasterone defends against sepsis-induced ALI by inhibiting inflammatory responses and oxidative stress, which depends heavily on the upregulation of the Nrf2 pathway through phosphorylation of AKT(Ser473)/GSK3β(Ser9). These results suggest cyasterone may be a valuable drug candidate for preventing sepsis-related ALI.

Saikosaponin D attenuates inflammatory response and cell apoptosis of lipopolysaccharide-induced lung epithelial cells

BACKGROUND

Acute lung injury (ALI) is a prevalent complication of sepsis with high mortality rate. Saikosaponin D (SSD) is a triterpenoid saponin that has been reported to alleviate sepsis-triggered renal injury in mice. Nonetheless, the therapeutic effect of SSD on sepsis-evoked ALI is unclarified.

METHODS

Lipopolysaccharide (LPS) from Escherichia coli 055:B5 was utilized to stimulate lung epithelial cell line MLE-12. A mouse model of sepsis was established. CCK-8 assay was employed for determining cytotoxicity. ELISA was utilized for determining proinflammatory cytokine production. Flow cytometry and western blotting were implemented for evaluating cell apoptosis. Hematoxylin-eosin staining was conducted for histologic analysis of murine lung tissues.

RESULTS

SSD alleviated LPS-triggered inflammation and cell apoptosis of MLE-12 cells. SSD treatment ameliorated the pathological damages, inflammatory response, and cell apoptosis in the lungs of septic mice.

CONCLUSION

SSD protects against sepsis-triggered ALI by inhibiting inflammation and cell apoptosis in MLE-12 cells and septic mouse mice.

The landscape of pathophysiology guided therapeutic strategies for gout treatment

INTRODUCTION

Gout is a common autoinflammatory disease caused by hyperuricemia with acute and/or chronic inflammation as well as tissue damage. Currently, urate-lowering therapy (ULT) and anti-inflammatory therapy are used as first-line strategies for gout treatment. However, traditional drugs for gout treatment exhibit some unexpected side effects and are not suitable for certain patients due to their comorbidity with other chronic disease.

AREAS COVERED

In this review, we described the pathophysiology of hyperuricemia and monosodium urate (MSU) crystal induced inflammatory response during gout development in depth and comprehensively summarized the advances in the investigation of promising ULT drugs as well as anti-inflammatory drugs that might be safer and more effective for gout treatment.

EXPERT OPINION

New drugs that are developed based on these molecular mechanisms exhibited great efficacy on reduction of disease burden both in vitro and in vivo, implying their potential for clinical application. Moreover, hyperthermia also showed regulation effect on MSU crystals formation and the signaling pathways involved in inflammation.

Monotropein alleviates sepsis-elicited acute lung injury via the NF-κB pathway

OBJECTIVES

To address the effect and mechanism of Monotropein (Mon) on sepsis-induced acute lung injury (ALI).

METHODS

ALI model was established by lipopolysaccharide (LPS)-stimulated mouse lung epithelial cell lines (MLE-12) and cecal ligation and puncture (CLP)-treated mice, respectively. The function of Mon was examined by cell counting kit-8 (CCK-8), pathological staining, the pulmonary function examination, flow cytometry, enzyme-linked immunosorbent assay, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labellingand western blot.

RESULTS

Mon increased the LPS-reduced viability but decreased the LPS-evoked apoptosis rate in MLE-12 cells. Mon suppressed the concentrations and protein expressions of proinflammatory factors, and the expressions of fibrosis-related proteins in LPS-challenged MLE-12 cells compared with LPS treatment alone. Mechanically, Mon downregulated the levels of NF-κB pathway, which was confirmed with the application of the receptor activator of nuclear factor-κB ligand (RANKL). Correspondingly, RANKL reversed the ameliorative effect of Mon on the proliferation, apoptosis, inflammation and fibrosis. Moreover, Mon improved the pathological manifestations, apoptosis, the W/D ratio and pulmonary function indicators in CLP-treated mice. Consistently, Mon attenuated inflammation, fibrosis and NF-κB pathway in CLP-treated mice.

CONCLUSION

Mon inhibited apoptosis, inflammation and fibrosis to alleviate sepsis-evoked ALI via the NF-κB pathway.

The role of macrophages polarization in sepsis-induced acute lung injury

Sepsis presents as a severe infectious disease frequently documented in clinical settings. Characterized by its systemic inflammatory response syndrome, sepsis has the potential to trigger multi-organ dysfunction and can escalate to becoming life-threatening. A common fallout from sepsis is acute lung injury (ALI), which often progresses to acute respiratory distress syndrome (ARDS). Macrophages, due to their significant role in the immune system, are receiving increased attention in clinical studies. Macrophage polarization is a process that hinges on an intricate regulatory network influenced by a myriad of signaling molecules, transcription factors, epigenetic modifications, and metabolic reprogramming. In this review, our primary focus is on the classically activated macrophages (M1-like) and alternatively activated macrophages (M2-like) as the two paramount phenotypes instrumental in sepsis' host immune response. An imbalance between M1-like and M2-like macrophages can precipitate the onset and exacerbate the progression of sepsis. This review provides a comprehensive understanding of the interplay between macrophage polarization and sepsis-induced acute lung injury (SALI) and elaborates on the intervention strategy that centers around the crucial process of macrophage polarization.

Identification of intestinal metabolic activation of loganin generated dialdehyde reactive intermediates improves intestinal bile salt hydrolase activities

Loganin is an iridoid with potent pharmacological effects. Loganin contains a hemiacetal structure and can convert to dialdehyde intermediates after deglycosylation. We hypothesized that the metabolites of loganin with hemiacetal can generate reactive dialdehyde intermediates. This study aims to characterize the metabolic profiling of loganin and especially for the unstable dialdehyde intermediates by using ultra-performance liquid chromatograph-quadrupole orbitrap mass spectrometry. In this study, a total of 26 stable metabolites were identified in loganin-treated rats. Loganin underwent different metabolism in the intestine and liver, which was confirmed mainly by the metabolites in the hepatic portal vein. In the intestine, the major metabolic pathways were ester hydrolysis and deglycosylation, followed by methylation and dehydrogenation. The hepatic metabolism pathways were hydrogenation, hydroxylation, glucuronidation, and sulfonation. The circulating metabolites with high abundance were mainly derived from intestinal metabolism. Importantly, 11 unstable dialdehyde intermediates of loganin were identified and described for the first time. The dialdehyde intermediates were identified by their dihydropyridine conjugates with amino acids. The dialdehyde intermediates were mainly produced in the intestine. The dialdehyde intermediates enable covalent modification of intestinal proteins. Loganin can up-regulate the activity of intestinal bile salt hydrolase (BSH), catalyzing bile acid metabolism. The level of protein adducts was positively associated with BSH activity, indicating dialdehyde intermediates played a key role in the up-regulation of BSH activities. In conclusion, this study not only demonstrates the characteristic metabolic fate of loganin but also facilitates the understanding of the pharmacologic effects of dialdehyde intermediates.

Uncovering the active constituents and mechanisms of Rujin Jiedu powder for ameliorating LPS-induced acute lung injury using network pharmacology and experimental investigations

Background: Acute lung injury (ALI) is a common clinical disease with high mortality. Rujin Jiedu powder (RJJD) has been clinically utilized for the treatment of ALI in China, but the active constituents in RJJD and its protective mechanisms against ALI are still unclear. Methodology: ALI mice were established by intraperitoneal injection of LPS to test the effectiveness of RJJD in treating ALI. Histopathologic analysis was used to assess the extent of lung injury. An MPO (myeloperoxidase) activity assay was used to evaluate neutrophil infiltration. Network pharmacology was used to explore the potential targets of RJJD against ALI. Immunohistochemistry and TUNEL staining were performed to detect apoptotic cells in lung tissues. RAW264.7 and BEAS-2B cells were used to explore the protective mechanisms of RJJD and its components on ALI in vitro. The inflammatory factors (TNF-α, IL-6, IL-1β and IL-18) in serum, BALF and cell supernatant were assayed using ELISA. Western blotting was performed to detect apoptosis-related markers in lung tissues and BEAS-2B cells. Results: RJJD ameliorated pathological injury and neutrophil infiltration in the lungs of ALI mice and decreased the levels of inflammatory factors in serum and BALF. Network pharmacology investigations suggested that RJJD treated ALI via regulating apoptotic signaling pathways, with AKT1 and CASP3 as crucial targets and PI3K-AKT signaling as the main pathway. Meanwhile, baicalein, daidzein, quercetin and luteolin were identified as key constituents in RJJD targeting on the above crucial targets. Experimental investigations showed that RJJD significantly upregulated the expression of p-PI3K, p-Akt and Bcl-2, downregulated the expression of Bax, caspase-3 and caspase-9 in ALI mice, and attenuated lung tissue apoptosis. Four active constituents in RJJD (baicalein, daidzein, quercetin and luteolin) inhibited the secretion of TNF-α and IL-6 in LPS-induced RAW264.7 cells. Among these components, daidzein and luteolin activated the PI3K-AKT pathway and downregulated the expression of apoptosis-related markers induced by LPS in BEAS-2B cells. Conclusion: RJJD alleviates the inflammatory storm and prevents apoptosis in the lungs of ALI mice. The mechanism of RJJD in treating ALI is related to the activation of PI3K-AKT signaling pathway. This study provides a scientific basis for the clinical application of RJJD.

Loganin attenuates neuroinflammation after ischemic stroke and fracture by regulating α7nAChR-mediated microglial polarization

Fracture in acute stage of ischemic stroke can increase inflammatory response and enhance stroke injury. Loganin alleviates the symptoms of many inflammatory diseases through its anti-inflammatory effect, but its role in ischemic stroke and fracture remains to be explored. Here, mice were handled with permanent middle cerebral artery occlusion (pMCAO) followed by tibial fracture 1 day later to establish a pMCAO+fracture model. Loganin or Methyllycaconitine (MLA, a specific a7nAchR inhibitor) were intragastrically administered 2 or 0.5 h before pMCAO, respectively. And mouse motor function and infarct volume were evaluated 3 days after pMCAO. We found that loganin alleviated the neurological deficit, cerebral infarction volume, and neuronal apoptosis (NeuN⁺ TUNEL⁺ ) in mice with pMCAO+fracture. And loganin suppressed pMCAO+fracture-induced neuroinflammation by promoting M2 microglia polarization (Iba1⁺ CD206⁺ ) and inhibiting M1 microglia polarization (Iba1⁺ CD11b⁺ ). While administration with MLA reversed the protective effect of loganin on pMCAO+fracture-induced neurological deficit and neuroinflammation. Next, LPS was used to stimulate BV2 microglia to simulate pMCAO+fracture-induced inflammatory microenvironment in vitro. Loganin facilitated the transformation of LPS-stimulated BV2 cells from M1 pro-inflammatory state (CD11b⁺ ) to M2 anti-inflammatory state (CD206⁺ ), which was antagonized by treatment with MLA. And loganin induced autophagy activation in LPS-stimulated BV2 cells by activating a7nAchR. Moreover, treatment with rapamycin (an autophagy activator) neutralized the inhibitory effect of MLA on loganin induced transformation of BV2 cells to M2 phenotype. Furthermore, BV2 cells were treated with LPS, LPS + loganin, LPS + loganin+MLA, or LPS + loganin+MLA+ rapamycin to obtain conditioned medium (CM) for stimulating primary neurons. Loganin reduced the damage of primary neurons caused by LPS-stimulated BV2 microglia through activating a7nAchR and inducing autophagy activation. In conclusion, loganin played anti-inflammatory and neuroprotective roles in pMCAO + fracture mice by activating a7nAchR, enhancing autophagy and promoting M2 polarization of microglia.

Natural Plant Extract - Loganin: A Hypothesis for Psoriasis Treatment Through Inhibiting Oxidative Stress and Equilibrating Immunity via Regulation of Macrophage Polarization

Psoriasis, a chronic immune-mediated inflammatory skin disease, influences approximately 2-3% of the world's population. At present, the etiology of psoriasis remains unclear and there is still no causal treatment available. Recent studies indicate that oxidative stress (OS) and T cells dysregulation may participate in the pathogenesis of psoriasis, among which M1-dominant macrophage polarization is a crucial contributor. Macrophages mainly polarize into two different subsets, ie, classically activated macrophage (M1) and alternatively activated macrophage (M2). M1 polarization tends to exacerbate psoriasis via producing substantial reactive oxygen species (ROS) and inflammatory mediators, to encourage OS invasion and T cells dysregulation. Thus, targeting M1 polarization can be a possible therapeutic alternative for psoriasis. Loganin, belonging to iridoid glycosides, is a pharmaceutically active ingredient originated from Cornus officinalis, exerting multiple biological activities, eg, immunomodulation, antioxidation, anti-inflammation, etc. More importantly, it could effectively suppress M1 polarization, thereby arresting OS aggression and T cells' dysregulation. Numerous studies have confirmed that loganin is quite reliable for diseases treatment via suppressing M1 polarization. Nevertheless, reports about loganin treating psoriasis have seldom appeared so far. Accordingly, we hold a hypothesis that loganin would availably manage psoriasis through preventing M1 polarization. Data from previous studies guarantee the potential of loganin in control of psoriasis.

Natural Monoterpenes as Potential Therapeutic Agents against Atherosclerosis

Traditional herbal medicines based on natural products play a pivotal role in preventing and managing atherosclerotic diseases, which are among the leading causes of death globally. Monoterpenes are a large class of naturally occurring compounds commonly found in many aromatic and medicinal plants. Emerging evidence has shown that monoterpenes have many biological properties, including cardioprotective effects. Remarkably, an increasing number of studies have demonstrated the therapeutic potential of natural monoterpenes to protect against the pathogenesis of atherosclerosis. These findings shed light on developing novel effective antiatherogenic drugs from these compounds. Herein, we provide an overview of natural monoterpenes' effects on atherogenesis and the underlying mechanisms. Monoterpenes have pleiotropic and multitargeted pharmacological properties by interacting with various cell types and intracellular molecular pathways involved in atherogenesis. These properties confer remarkable advantages in managing atherosclerosis, which has been recognized as a multifaceted vascular disease. We also discuss limitations in the potential clinical application of monoterpenes as therapeutic agents against atherosclerosis. We propose perspectives to give new insights into future preclinical research and clinical practice regarding natural monoterpenes.

Extracellular vesicles in the pathogenesis and treatment of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common life-threatening lung diseases associated with acute and severe inflammation. Both have high mortality rates, and despite decades of research on clinical ALI/ARDS, there are no effective therapeutic strategies. Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury. Recently, studies on the role of extracellular vesicles (EVs) in regulating normal and pathophysiologic cell activities, including inflammation and injury responses, have attracted attention. Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes, which can be used to diagnose and predict the development of ALI/ARDS. EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function, and thereby promote cell proliferation and tissue regeneration. This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation, particularly ALI/ARDS.

Glycyrrhizic Acid Protects Experimental Sepsis Rats against Acute Lung Injury and Inflammation

Background

The incidence of acute lung injury/acute respiratory distress (ALI/ARDS) is high in sepsis aggravating morbidity and mortality. Glycyrrhizic acid (GA) has pharmacological activities in the treatment of inflammation and antiviral.

Materials and Methods

Sepsis rats were constructed by the cecal ligation and puncture (CLP) surgery. After GA (25 and 50 mg/kg) injection, the survival rate, blood oxygen, biochemical indexes, myeloperoxidase (MPO) activity, and wet/dry weight ratio of the lung were observed. The bronchoalveolar lavage fluid was collected to count the cells and measure the level of TNF-α, IL-1β, IL-10, and high mobility group box-1 protein (HMGB1). Lung tissue sections were taken to observe the levels of histopathological injury and apoptosis by HE and TUNEL staining. The levels of HMGB1, TLR4, p-38 MAPK, NF-κB, and ERK1/2 proteins were observed by immunohistochemistry and Western blot.

Results

GA treatment improved the survival rate, blood oxygen, ALT, AST, BUN, and Scr of CLP rats. It could advance the MPO activity, the wet/dry weight ratio, histopathological injury, apoptosis, and the IL-10 level in the lung. After GA injection, the number of total cells, neutrophils, and macrophages in the CLP rats was reduced and the levels of TNF-α, IL-1β, HMGB1, TLR4, p-38 MAPK, and ERK1/2 in the CLP rat were also repressed.

Conclusions

GA treatment may improve the sepsis-induced ALI/ARDS and inflammation by inhibiting HMBG1. This study provided an experimental basis for the prevention and treatment of ALI/ARDS caused by sepsis.

ACT001 suppressing M1 polarization against inflammation via NF-κB and STAT1 signaling pathways alleviates acute lung injury in mice

ACT001 has been shown to exhibit excellent antitumor and anti-fibrosis activities. However, the role of ACT001 in acute lung injury (ALI) and the underlying mechanism remains largely unclear. The present study aimed to investigate the protective effects of ACT001 on ALI and explore the potential mechanisms. Herein, we firstly established the ALI mouse model induced by intratracheal instillation of lipopolysaccharide (LPS). ACT001 treatment significantly alleviated histopathological changes of lung tissues with lower infiltration of pulmonary M1 macrophages in ALI mice. Then, we performed in vitro experiment and found that ACT001 treatment effectively inhibited the M1 phenotype of RAW264.7 and THP-1.. Next, we performed pull-down and mass spectrometry analysis to screen the interacting proteins of ACT001, identifying IKKβ and STAT1 as the critical target proteins of ACT001. And ACT001 treatment significantly suppressed the NF-κB and STAT1 pathways, thereby inhibiting the M1 polarization against inflammation in vivo and in vitro. Finally, we used IMD 0354 (IMD) and Fludarabine (Flud) to specifically block the activity of IKKβ and STAT1, and stimulated macrophages through IKKβ and STAT1 overexpression. Our data clearly showed that ACT001-induced decrease of the M1 polarization was blocked by IMD and Flud treatment, and reversed by IKKβ and STAT1 overexpression in RAW264.7 cells. In conclusion, we discovered that ACT001 significantly alleviates inflammation and limits M1 phenotype of pulmonary macrophages via suppressing NF-κB and STAT1 signaling pathways, providing new insights for the development of drugs to treat ALI/ARDS.

Phytochemistry, synthesis, analytical methods, pharmacological activity, and pharmacokinetics of loganin: A comprehensive review

Iridoid glycosides (IGs) are found in many medicinal and edible plants, such as Gardenia jasminoides, Cistanche tubulosa, Eucommia ulmoides, Rehmanniae Radix, Lonicera japonica, and Cornus officinalis. Loganin, an IG, is one of the main active ingredient of Cornus officinalis Sieb. et Zucc., which approved as a medicinal and edible plant in China. Loganin has been widely concerned due to its extensive pharmacological effects, including anti-diabetic, antiinflammatory, neuroprotective, and anti-tumor activities, etc. Studies have shown that these underlying mechanisms include anti-oxidation, antiinflammation and anti-apoptosis by regulating a variety of signaling pathways, such as STAT3/NF-κB, JAK/STAT3, TLR4/NF-κB, PI3K/Akt, MCP-1/CCR2, and RAGE/Nox4/p65 NF-κB signaling pathways. In order to better understand the research status of loganin and promote its application in human health, this paper systematically summarized the phytochemistry, analysis methods, synthesis, pharmacological properties and related mechanisms, and pharmacokinetics based on the research in the past decades.

The Effect of Shionone on Sepsis-Induced Acute Lung Injury by the ECM1/STAT5/NF-κB Pathway

Purpose: The purpose of the present study was to estimate the effect of shionone (SHI) on sepsis-induced acute lung injury (ALI).

Methods: The cecal ligation and puncture (CLP) surgery was performed to induce sepsis in mice. Pulmonary hematoxylin and eosin staining, the wet/dry ratio, myeloperoxidase (MPO) activity, and the survival rate were detected. The RAW264.7 cells were treated with SHI and stimulated with lipopolysaccharide (LPS). The cells were also overexpressed by extracellular mechanism protein 1 (ECM1) adenovirus. The relative levels of granulocyte–macrophage colony-stimulating factor, IL-6, IL-1β, TNF-α, IL-10, and TGF-β in the serum and supernatant were measured by ELISA. The protein expressions of ECM1, p-STAT5, signal transducer and activator of transcription 5 (STAT5), p-NF-κB, nuclear factor kappa-B (NF-κB), Arg1, CD206, CD16/32, and iNOS in the CLP-induced lung tissues and LPS-induced cells were detected by western blot. The cell counts of Ly6G, F4/80, CD16/32, and CD206 were evaluated by flow cytometry. The ECM1 expression was also observed by immunohistochemistry and immunofluorescence staining.

Results: As a result, the histopathological change, pulmonary edema, and the MPO activity were relieved by SHI. SHI treatment increased the percentage of neutrophil and macrophage in the bronchoalveolar lavage fluid. Besides, SHI administration inhibited pro-inflammatory cytokines and M1 phenotype indices, as well as augmented the anti-inflammatory cytokines and M2 phenotype indices. SHI also attenuated the ECM1/STAT5/NF-κB pathway both in vivo and in vitro. The overexpression of ECM1 confirmed that the regulated effect of SHI was due to ECM1 signaling.

Conclusion: In conclusion, the present study suggests that SHI ameliorated sepsis-induced ALI by screwing M1 phenotype to M2 phenotype macrophage via the ECM1/STAT5/NF-κB pathway.

Protective effect of cynaroside on sepsis-induced multiple organ injury through Nrf2/HO-1-dependent macrophage polarization

Cynaroside is the primary flavonoid component of honeysuckle which has been widely used as Chinese traditional medicine given its anti-inflammation properties. Overactive systemic inflammatory response and multi-organ injury are the leading causes of life-threatening sepsis. Regulation of macrophage polarization balance may act as a promising strategy for its treatment. In the present study, we aimed to investigate whether cynaroside exerted protective effects against sepsis and its potential mechanism. Building upon a sepsis mouse model, we observed cynaroside alleviated serum levels of inflammatory factors including IL-1β and TNF-α at 5 and 10 mg/kg. The pathological injury of heart, kidney and lung was remarkedly attenuated as the levels of blood urea nitrogen, creatinine, creatine kinase-MB and lactate dehydrogenase were reduced nearly 2.8-, 2.7-, 2.4-, and 2.5-fold as compared with the sepsis mice, respectively. We further demonstrated cynaroside suppressed the biomarker of pro-inflammatory macrophage M1 phenotype (iNOS+) and promotes the anti-inflammatory M2 polarization (CD206+) in the injury organs of septic mice. Mechanistic research verified cynaroside inhibited LPS-induced polarization of macrophage into M1 phenotype, which can be highly blocked by Nrf2 inhibitor. Expectedly, Nrf2 and its downstream (Heme oxygenase-1 (HO-1)) was upregulated in injury organs after treating with cynaroside, indicating the involvement of Nrf2 signaling. Taken together, the data claims cynaroside ameliorated systematic inflammation and multi-organ injury dependent on Nrf2/HO-1 pathway in septic mice.