The macrophage response towards LPS and its control through the p38(MAPK)-STAT3 axis

Proteoglycan 4 (Lubricin) and Regulation of Xanthine Oxidase in Synovial Macrophage as A Mechanism of Controlling Synovitis

Background

Synovial macrophages (SMs) are important effectors of joint health and disease. A novel Cx3CR1 + TREM2 + SM population expressing the tight junction protein claudin-5, was recently discovered in synovial lining. Ablation of these SMs was associated with onset of arthritis. Proteoglycan 4 (PRG4) is a mucinous glycoprotein that fulfills lubricating and homeostatic roles in the joint. The aim of this work is to study the role of PRG4 in modulating synovitis in the context of SM homeostasis and assess the contribution of xanthine oxidase (XO)-hypoxia inducible factor alpha (HIF-1α) axis to this regulation.

Methods

We used Prg4 FrlioxP/FrtloxP ;R26 FlPoER/+ , a novel transgenic mouse, where the Prg4 Frt allele normally expresses the PRG4 protein and was designed to flank the first two exons of Prg4 with a flippase recognition target and "LOXP" sites. Inducing flippase activity with tamoxifen (TAM) inactivates the Frt allele and thus creates a conditional knockout state. We studied anti-inflammatory SMs and XO by quantitative immunohistochemistry, isolated RNA and studied immune pathway activations by multiplexed assays and isolated SMs and studied PRG4 signaling dysfunction in relation to glycolytic switching due to pro-inflammatory activation. Prg4 inactivated mice were treated with oral febuxostat, a specific XO inhibitor, and quantification of Cx3CR1 + TREM2 + SMs, XO immunostaining and synovitis assessment were conducted.

Results

Prg4 inactivation induced Cx3CR1 + TREM2 + SM loss (p < 0.001) and upregulated glycolysis and innate immune pathways in the synovium. In isolated SMs, Xdh (p < 0.01) and Hif1a (p < 0.05) were upregulated. Pro-inflammatory activation of SMs was evident by enhanced glycolytic flux and XO-generated reactive oxygen species (ROS). Febuxostat reduced glycolytic flux (p < 0.001) and HIF-1α levels (p < 0.0001) in SMs. Febuxostat also reduced systemic inflammation (p < 0.001), synovial hyperplasia (p < 0.001) and preserved Cx3CR1 + TREM2 + SMs (p < 0.0001) in synovia of Prg4 inactivated mice.

Conclusions

PRG4 is a biologically significant modulator of synovial homeostasis via inhibition of XO expression and downstream HIF-1a activation. PRG4 signaling is anti-inflammatory and promotes synovial homeostasis in chronic synovitis, where direct XO inhibition is potentially therapeutic in chronic synovitis.

Enrichment of Cis-Acting Regulatory Elements in Differentially Methylated Regions Following Lipopolysaccharide Treatment of Bovine Endometrial Epithelial Cells

Endometritis is an inflammatory disease that negatively influences fertility and is common in milk-producing cows. An in vitro model for bovine endometrial inflammation was used to identify enrichment of cis-acting regulatory elements in differentially methylated regions (DMRs) in the genome of in vitro-cultured primary bovine endometrial epithelial cells (bEECs) before and after treatment with lipopolysaccharide (LPS) from E. coli, a key player in the development of endometritis. The enriched regulatory elements contain binding sites for transcription factors with established roles in inflammation and hypoxia including NFKB and Hif-1α. We further showed co-localization of certain enriched cis-acting regulatory motifs including ARNT, Hif-1α, and NRF1. Our results show an intriguing interplay between increased mRNA levels in LPS-treated bEECs of the mRNAs encoding the key transcription factors such as AHR, EGR2, and STAT1, whose binding sites were enriched in the DMRs. Our results demonstrate an extraordinary cis-regulatory complexity in these DMRs having binding sites for both inflammatory and hypoxia-dependent transcription factors. Obtained data using this in vitro model for bacterial-induced endometrial inflammation have provided valuable information regarding key transcription factors relevant for clinical endometritis in both cattle and humans.

Apoptosis-induced decline in hippocampal microglia mediates the development of depression-like behaviors in adult mice triggered by unpredictable stress during adolescence

Depression triggered by harmful stress during adolescence is a common problem that can affect mental health. To date, the mechanisms underlying this type of depression remain unclear. One mechanism for the promotion of depression by chronic stress in adulthood is the loss of hippocampal microglia. Since deleterious stress in adolescence also activates microglia, we investigated the dynamic changes of microglia in the hippocampus in mice exposed to chronic unpredictable stress (CUS) in adolescence. Our results showed that 12 days of CUS stimulation in adolescence induced typical depression-like behaviors in adult mice, which were accompanied by a significant decrease and dystrophy of microglia in the dentate gyrus of the hippocampus. Further analysis showed that this decrease in microglia was mediated by the initial response of microglia to unpredictable stress in the dentate gyrus of the hippocampus and their subsequent apoptosis. Blocking the initial response of microglia to unpredictable stress by pretreatment with minocycline was able to prevent apoptosis and microglial decline as well as the development of depression-like behaviors in adult mice induced by adolescent CUS. Moreover, administration of lipopolysaccharide (LPS) or macrophage-colony stimulatory factor (M-CSF), two drugs that reversed microglia decline in the dentate gyrus, ameliorated the depression-like behaviors induced by CUS stimulation in adolescence. These findings reveal a novel mechanism for the development of depression-like behaviors in animals triggered by deleterious stress in adolescence and suggest that reversing microglial decline in the hippocampus may be a hopeful strategy for the treatment of depression triggered by deleterious stress in adolescence.

Nrf2 Signaling Pathway: Focus on Oxidative Stress in Spinal Cord Injury

Spinal cord injury (SCI) is a serious, disabling injury to the central nervous system that can lead to motor, sensory, and autonomic dysfunction below the injury plane. SCI can be divided into primary injury and secondary injury according to its pathophysiological process. Primary injury is irreversible in most cases, while secondary injury is a dynamic regulatory process. Secondary injury involves a series of pathological events, such as ischemia, oxidative stress, inflammatory events, apoptotic pathways, and motor dysfunction. Among them, oxidative stress is an important pathological event of secondary injury. Oxidative stress causes a series of destructive events such as lipid peroxidation, DNA damage, inflammation, and cell death, which further worsens the microenvironment of the injured site and leads to neurological dysfunction. The nuclear factor erythrocyte 2-associated factor 2 (Nrf2) is considered to be a key pathway of antioxidative stress and is closely related to the pathological process of SCI. Activation of this pathway can effectively inhibit the oxidative stress process and promote the recovery of nerve function after SCI. Therefore, the Nrf2 pathway may be a potential therapeutic target for SCI. This review deeply analyzed the generation of oxidative stress in SCI, the role and mechanism of Nrf2 as the main regulator of antioxidant stress in SCI, and the influence of cross-talk between Nrf2 and related pathways that may be involved in the pathological regulation of SCI on oxidative stress, and summarized the drugs and other treatment methods based on Nrf2 pathway regulation. The objective of this paper is to provide evidence for the role of Nrf2 activation in SCI and to highlight the important role of Nrf2 in alleviating SCI by elucidating the mechanism, so as to provide a theoretical basis for targeting Nrf2 pathway as a therapy for SCI.

Macrophage plasticity: signaling pathways, tissue repair, and regeneration

Macrophages are versatile immune cells with remarkable plasticity, enabling them to adapt to diverse tissue microenvironments and perform various functions. Traditionally categorized into classically activated (M1) and alternatively activated (M2) phenotypes, recent advances have revealed a spectrum of macrophage activation states that extend beyond this dichotomy. The complex interplay of signaling pathways, transcriptional regulators, and epigenetic modifications orchestrates macrophage polarization, allowing them to respond to various stimuli dynamically. Here, we provide a comprehensive overview of the signaling cascades governing macrophage plasticity, focusing on the roles of Toll-like receptors, signal transducer and activator of transcription proteins, nuclear receptors, and microRNAs. We also discuss the emerging concepts of macrophage metabolic reprogramming and trained immunity, contributing to their functional adaptability. Macrophage plasticity plays a pivotal role in tissue repair and regeneration, with macrophages coordinating inflammation, angiogenesis, and matrix remodeling to restore tissue homeostasis. By harnessing the potential of macrophage plasticity, novel therapeutic strategies targeting macrophage polarization could be developed for various diseases, including chronic wounds, fibrotic disorders, and inflammatory conditions. Ultimately, a deeper understanding of the molecular mechanisms underpinning macrophage plasticity will pave the way for innovative regenerative medicine and tissue engineering approaches.

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.

Tofacitinib Affects M1-like and M2-like Polarization and Tissue Factor Expression in Macrophages of Healthy Donors and IBD Patients

BACKGROUND

Tofacitinib, as inhibitor of Janus kinases (JAK), interrupts the transmission of numerous pro-inflammatory cytokines involved in the pathogenesis of inflammatory bowel diseases (IBD). Therefore, tofacitinib provides a potent option to treat ulcerative colitis (UC). Besides the anti-inflammatory potential, inhibition of widespread JAKs carries the risk of side effects. Macrophages are involved in the form of different subtypes in inflammation, wound healing, and even coagulation. This study aimed to explore the balanced use of tofacitinib in M1-like as well as M2-like macrophages of healthy donors and patients with IBD.

METHODS

Monocytes of healthy donors and patients with chronic courses of IBD were obtained from blood samples. Macrophage colony-stimulating factor (M-CSF)-derived macrophages were treated with tofacitinib (1 µM, 5 µM, 10 µM) and polarized with either lipopolysaccharide and interferon (IFN)-γ towards M1-like-phenotype or with interleukin (IL)-4 towards M2-like-phenotype. ELISA and flow cytometry were used to evaluate cytokine levels and surface molecules.

RESULTS

Tofacitinib had a modulating effect on M1-like macrophages whereby the effect on pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-12, IL-23) was less pronounced than the induction of anti-inflammatory IL-10. However, during M2-like polarization tofacitinib impaired the development of the corresponding phenotype becoming evident through decreased IL-10 levels and CD206 expression in treated macrophages. In both phenotypes, tofacitinib strongly downregulated the expression of immunostimulatory molecules (CD80, CD86, CD83, CD40). Furthermore, a dose-dependent correlation between treatment with tofacitinib and expressed tissue factor was noticed.

CONCLUSIONS

Tofacitinib influences both polarizations (M1/M2) and the expression of tissue factor in a dose-dependent manner.

Explore the underlying oral efficacy of α-, β-, γ-Cyclodextrin against the ulcerative colitis using in vitro and in vivo studies assisted by network pharmacology

The incidence of ulcerative colitis (UC) is rising worldwide. As a refractory and recurrent disease, UC could seriously affect the patients' quality of life. However, current clinical medical treatments for UC are accompanied by various side effects, especially for long-term applications. Here, the underlying efficacy of cyclodextrins (CDs) was studied. As common excipients, CDs endow proven safety for long-term applications. Results of predictive methods derived from network pharmacology prompted the potential anti-inflammatory effects of CDs by oral administration. RAW264.7 cell experiments verified that CDs could inhibit the excessive secretion of TNF-α (β-CD > α-CD ≈ γ-CD), IL-6, and NO (α-CD > β-CD ≈ γ-CD) as predicted. In mice with DSS-induced acute UC, oral administration of CDs could effectively mitigate the pathological damage of colon tissue and reduce the level of inflammatory mediators. Moreover, 16S rRNA sequencing displayed that gut microbes disturbed by DSS were significantly regulated by CDs. Conclusively, the study showed the therapeutic application prospects of CDs in UC treatment and indicated the feasibility and advantages of developing 'new' therapeutic activities of 'old' ingredients.Communicated by Ramaswamy H. Sarma.

Activation of angiogenin expression in macrophages by lipopolysaccharide via the TLR4/NF-κB pathway in colitis

Inflammatory bowel disease (IBD) is a debilitating condition that can lead to life-threatening complications. Macrophages are crucial in IBD management because they secrete various cytokines and regulate tissue repair. Macrophage-derived angiogenin (ANG) has been shown to be essential for limiting colonic inflammation, but its upstream regulatory pathway and role in macrophages remain unclear. Here we show that ANG expression is up-regulated in macrophages during colitis treatment or upon lipopolysaccharides (LPS) treatment. Mechanistically, LPS activates Toll-like receptor 4 (TLR4) to initiate NF-κB translocation from the cytoplasm to the nucleus, where it binds to the ANG promoter and enhances its transcriptional activity, leading to increased ANG expression. Interestingly, our data also reveal that the deletion of ANG in macrophages has no adverse effect on key macrophage functions, such as phagocytosis, chemotaxis, and cell survival. Our findings establish a "LPS-TLR4-NF-κB-ANG" regulatory axis in inflammatory disorders and confirm that ANG controls inflammation in a paracrine manner, highlighting the importance of ANG as a key mediator in the complex network of inflammatory processes.

VX-702 Ameliorates the Severity of Sepsis-Associated Acute Kidney Injury by Downregulating Inflammatory Factors in Macrophages

Purpose

Sepsis-associated acute kidney injury (S-AKI) contributes to high mortality, but it is lack of specific treatments. We aimed to investigate the underlying mechanism of S-AKI and to identify target drugs to alleviate AKI.

Methods

We establish a stable mouse model of S-AKI by Pseudomonas aeruginosa incision infection. Based on high-throughput sequencing and bioinformatics analysis, we investigated the underlying mechanism and selected the target drug (VX-702) for S-AKI. An in vitro model established by co-cultured of kidney tubular epithelial cell line (TCMK-1) cells with lipopolysaccharide (LPS)-induced leukemic monocyte/macrophage cells (RAW264.7), we explored the effect of VX-702 on S-AKI.

Results

The data showed interleukin (IL)-6 and IL-1β were the hub genes, and the mitogen-activated protein kinase (MAPK) signaling pathway was the main pathway involved in S-AKI. Administration of VX-702 by oral gavage decreased the elevated concentrations of IL-6, IL-1β, serum creatinine, and blood urea nitrogen in mice with S-AKI. Moreover, VX-702 reduced the number of apoptotic cells in damaged kidney tissues. Cell viability was decreased, and the number of apoptotic cells was increased in TCMK-1 cells co-cultured with LPS-induced RAW264.7 cells compared to LPS-induced TCMK-1 cells. VX-702 treatment reversed this effect. VX-702 treatment reduced the levels of phosphorylated p38 MAPK and proinflammatory cytokines in RAW264.7 cells and the supernatant. VX-702 could bind IL-6, IL-1β and MAPK, and affect the binding of IL-1β and its receptor, as demonstrated by molecular docking.

Conclusion

VX-702 ameliorated S-AKI by inhibiting the release of proinflammatory cytokines from macrophages, indicating its potential as a novel therapeutic for S-AKI treatment.

Synergistic effect of paeoniflorin combined with luteolin in alleviating Lipopolysaccharides-induced acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) is an acute multifactorial infectious disease caused by trauma, pneumonia, shock and sepsis. Paeoniae Radix Rubra (Paeonia lactiflora Pall. or Paeonia veitchii Lynch, Chishao in Chinese, CS) and Salviae Miltiorrhizae Radix et Rhizoma (Salvia miltiorrhiza Bge., Lamiaceae, Danshen in Chinese, DS) are common traditional Chinese medicines (TCMs). CS-DS herb pair has been widely used to promote blood circulation and eliminate blood stasis in Chinese clinical practice, appearing in a variety of prescriptions. However, it is still unclear for the effect and active ingredients of the herb pair on ALI.

AIM OF THE STUDY

The study investigated the effect and active ingredients of CS-DS herb pair and demonstrated the synergistic effect and mechanisms of the active ingredients.

MATERIALS AND METHODS

Lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage cells and BALB/c mice were used to establish an ALI model to investigate the effect of CS-DS herb pair on ALI. Network pharmacology and molecular docking were used to analyze the active ingredients and potential mechanisms of the herb pair. The synergistic effects and mechanisms of active ingredients on ALI were validated by in vitro and in vivo experiments.

RESULTS

CS-DS herb pair had a synergistic effect on LPS-induced ALI. Based on the network pharmacology, the compounds paeoniflorin and luteolin were screened. Both paeoniflorin and luteolin had good affinity for NF-κB and MAPK by molecular docking. LPS stimulation of RAW264.7 cells resulted in a significant increase in ROS, NO, TNF-α, IL-6 and IL-1β, while the paeoniflorin combined with luteolin significantly reduced their expressions. In the LPS-induced ALI model, the combination also reduced the expression of inflammatory factors and oxidative stress levels. Furthermore, LPS activated the NF-κB and MAPK signaling pathways, whereas the combination decreased the expression of proteins in both pathways.

CONCLUSION

CS-DS herb pair alleviated LPS-induced ALI with the active ingredients paeoniflorin and luteolin, which suppressed inflammation and oxidative stress via regulation of NF-κB and MAPK signaling pathways.

Actions of remimazolam on inhibitory transmission of rat spinal dorsal horn neurons

Remimazolam is an ultra-short benzodiazepine that acts on the benzodiazepine site of γ-aminobutyric acid (GABA) receptors in the brain and induces sedation. Although GABA receptors are found localized in the spinal dorsal horn, no previous studies have reported the analgesic effects or investigated the cellular mechanisms of remimazolam on the spinal dorsal horn. Behavioral measures, immunohistochemistry, and in vitro whole-cell patch-clamp recordings of dorsal horn neurons were used to assess synaptic transmission. Intrathecal injection of remimazolam induced behavioral analgesia in inflammatory pain-induced mechanical allodynia (six rats/dose; p < 0.05). Immunohistochemical staining revealed that remimazolam suppressed spinal phosphorylated extracellular signal-regulated kinase activation (five rats/group, p < 0.05). In vitro whole-cell patch-clamp analysis demonstrated that remimazolam increased the frequency of GABAergic miniature inhibitory post-synaptic currents, prolonged the decay time (six rats; p < 0.05), and enhanced GABA currents induced by exogenous GABA (seven rats; p < 0.01). However, remimazolam did not affect miniature excitatory post-synaptic currents or amplitude of monosynaptic excitatory post-synaptic currents evoked by Aδ- and C-fiber stimulation (seven rats; p > 0.05). This study suggests that remimazolam induces analgesia by enhancing GABAergic inhibitory transmission in the spinal dorsal horn, suggesting its potential utility as a spinal analgesic for inflammatory pain.

Sebacic acid, a royal jelly-containing fatty acid, decreases LPS-induced IL-6 mRNA expression in differentiated human THP-1 macrophage-like cells

Macrophages produce many inflammatory mediators, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), in innate immune responses. However, excess production of these mediators by activated macrophages triggers deleterious effects, leading to disorders associated with inflammation. Royal jelly (RJ), a milky-white substance secreted by worker bees, contains unique fatty acids, including 10-hydroxy-2-decenoic acid (10H2DA) and sebacic acid (SA). 10H2DA has been reported to have various biological functions, such as anti-inflammation. However, the anti-inflammatory effect of SA is not fully understood. In this study, we investigated the effects of SA on lipopolysaccharide (LPS)-induced cytokine expression using differentiated human THP-1 macrophage-like cells. SA dose-dependently decreased LPS-induced mRNA expression of IL-6, but not TNF-α and IL-1β. SA suppressed the phosphorylation of signal transducers and activators of transcription 1 (STAT1) and STAT3, but hardly affected the activation of JNK, p38, or NF-κB. In addition, SA decreased LPS-induced interferon-β (IFN-β) expression, and the addition of IFN-β restored the inhibition by SA of LPS-induced STAT activation and IL-6 expression. Furthermore, SA suppressed LPS-induced nuclear translocation of interferon regulatory factor 3 (IRF3), a transcription factor responsible for IFN-β expression. Taken together, we conclude that SA selectively decreases LPS-induced expression of IL-6 mRNA through inhibition of the IRF3/IFN-β/STAT axis.

Stat3 Regulates Developmental Hematopoiesis and Impacts Myeloid Cell Function via Canonical and Non-Canonical Modalities

INTRODUCTION

Signal transducer and activator of transcription (STAT) 3 is extensively involved in the development, homeostasis, and function of immune cells, with STAT3 disruption associated with human immune-related disorders. The roles ascribed to STAT3 have been assumed to be due to its canonical mode of action as an inducible transcription factor downstream of multiple cytokines, although alternative noncanonical functional modalities have also been identified. The relative involvement of each mode was further explored in relevant zebrafish models.

METHODS

Genome editing with CRISPR/Cas9 was used to generate mutants of the conserved zebrafish Stat3 protein: a loss of function knockout (KO) mutant and a mutant lacking C-terminal sequences including the transactivation domain (ΔTAD). Lines harboring these mutations were analyzed with respect to blood and immune cell development and function in comparison to wild-type zebrafish.

RESULTS

The Stat3 KO mutant showed perturbation of hematopoietic lineages throughout primitive and early definitive hematopoiesis. Neutrophil numbers did not increase in response to lipopolysaccharide (LPS) or granulocyte colony-stimulating factor (G-CSF) and their migration was significantly diminished, the latter correlating with abrogation of the Cxcl8b/Cxcr2 pathway, with macrophage responses perturbed. Intriguingly, many of these phenotypes were not shared by the Stat3 ΔTAD mutant. Indeed, only neutrophil and macrophage development were disrupted in these mutants with responsiveness to LPS and G-CSF maintained, and neutrophil migration actually increased.

CONCLUSION

This study has identified roles for zebrafish Stat3 within hematopoietic stem cells impacting multiple lineages throughout primitive and early definitive hematopoiesis, myeloid cell responses to G-CSF and LPS and neutrophil migration. Many of these roles showed conservation, but notably several involved noncanonical modalities, providing additional insights for relevant diseases.

So Shiho Tang Reduces Inflammation in Lipopolysaccharide-Induced RAW 264.7 Macrophages and Dextran Sodium Sulfate-Induced Colitis Mice

So Shiho Tang (SSHT) is a traditional herbal medicine commonly used in Asian countries. This study evaluated the anti-inflammatory effect of SSHT and the associated mechanism using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and murine dextran sodium sulfate (DSS)-induced ulcerative colitis models. Pre-treatment of RAW 264.7 macrophages with SSHT significantly reduced LPS-induced inflammation by decreasing nitrite production and regulating the mitogen-activated protein kinase pathway. Meanwhile, in mice, DSS-induced colitis symptoms, including colon shortening and body weight loss, were attenuated by SSHT. Moreover, representative compounds of SSHT, including glycyrrhizic acid, ginsenoside Rb1, baicalin, saikosaponin A, and saikosaponin B2, were quantified, and their effects on nitrite production were measured. A potential anti-inflammatory effect was detected in LPS-induced RAW 264.7 cells. Our findings suggest that SSHT is a promising anti-inflammatory agent. Its representative components, including saikosaponin B2, ginsenoside Rb1, and baicalin, may represent the key active compounds responsible for eliciting the anti-inflammatory effects and can, therefore, serve as quality control markers in SSHT preparations.

Human antigen R transfers miRNA to Syntaxin 5 to synergize miRNA export from activated macrophages

Intercellular miRNA exchange acts as a key mechanism to control gene expression post-transcriptionally in mammalian cells. Regulated export of repressive miRNAs allows the expression of inflammatory cytokines in activated macrophages. Intracellular trafficking of miRNAs from the endoplasmic reticulum to endosomes is a rate-determining step in the miRNA export process and plays an important role in controlling cellular miRNA levels and inflammatory processes in macrophages. We have identified the SNARE protein Syntaxin 5 (STX5) to show a synchronized expression pattern with miRNA activity loss in activated mammalian macrophage cells. STX5 is both necessary and sufficient for macrophage activation and clearance of the intracellular pathogen Leishmania donovani from infected macrophages. Exploring the mechanism of how STX5 acts as an immunostimulant, we have identified the de novo RNA-binding property of this SNARE protein that binds specific miRNAs and facilitates their accumulation in endosomes in a cooperative manner with human ELAVL1 protein, Human antigen R. This activity ensures the export of miRNAs and allows the expression of miRNA-repressed cytokines. Conversely, in its dual role in miRNA export, this SNARE protein prevents lysosomal targeting of endosomes by enhancing the fusion of miRNA-loaded endosomes with the plasma membrane to ensure accelerated release of extracellular vesicles and associated miRNAs.

Pirfenidone alleviates chronic pancreatitis via suppressing the activation of pancreatic stellate cells and the M1 polarization of macrophages

In the realm of fibroinflammatory conditions, chronic pancreatitis (CP) stands out as a particularly challenging ailment, lacking a dedicated, approved treatment. The potential of Pirfenidone (PFD), a drug originally used for treating idiopathic pulmonary fibrosis (IPF), in addressing CP's fibrotic aspects has sparked new interest. This investigation focused on the role of PFD in diminishing fibrosis and immune response in CP, using a mouse model induced by caerulein. The research extended to in vitro studies examining the influence of PFD on pancreatic stellate cells' (PSCs) behavior and the polarization of macrophages into M1 and M2 types. Advanced techniques like RNA sequencing and comprehensive data analyses were employed to decode the molecular interactions of PFD with PSCs. Supplementary experiments using techniques such as quantitative real-time PCR, western blotting, and immunofluorescence were also implemented. Results showed a notable reduction in pancreatic damage in PFD-treated mice, manifested through decreased acinar cell atrophy, lower collagen deposition, and a reduction in macrophage presence. Further investigation revealed PFD's capacity to hinder PSCs' migration, growth, and activation, alongside a reduction in the production and secretion of extracellular matrix proteins. This effect is primarily achieved by interfering with signaling pathways such as TGF-β/Smad, Wnt/β-catenin, and JAK/STAT. Additionally, PFD selectively hampers M1 macrophage polarization through the STAT3 pathway, without impacting M2 polarization. These outcomes highlight PFD's dual mechanism in moderating PSC activity and M1 macrophage polarization, positioning it as a promising candidate for CP therapy.

Engineered extracellular vesicles carrying let-7a-5p for alleviating inflammation in acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening respiratory condition characterized by severe inflammation and lung tissue damage, frequently causing rapid respiratory failure and long-term complications. The microRNA let-7a-5p is involved in the progression of lung injury, inflammation, and fibrosis by regulating immune cell activation and cytokine production. This study aims to use an innovative cellular electroporation platform to generate extracellular vesicles (EVs) carring let-7a-5p (EV-let-7a-5p) derived from transfected Wharton's jelly-mesenchymal stem cells (WJ-MSCs) as a potential gene therapy for ALI.

METHODS

A cellular nanoporation (CNP) method was used to induce the production and release of EV-let-7a-5p from WJ-MSCs transfected with the relevant plasmid DNA. EV-let-7a-5p in the conditioned medium were isolated using a tangential flow filtration (TFF) system. EV characterization followed the minimal consensus guidelines outlined by the International Society for Extracellular Vesicles. We conducted a thorough set of therapeutic assessments, including the antifibrotic effects using a transforming growth factor beta (TGF-β)-induced cell model, the modulation effects on macrophage polarization, and the influence of EV-let-7a-5p in a rat model of hyperoxia-induced ALI.

RESULTS

The CNP platform significantly increased EV secretion from transfected WJ-MSCs, and the encapsulated let-7a-5p in engineered EVs was markedly higher than that in untreated WJ-MSCs. These EV-let-7a-5p did not influence cell proliferation and effectively mitigated the TGF-β-induced fibrotic phenotype by downregulating SMAD2/3 phosphorylation in LL29 cells. Furthermore, EV-let-7a-5p regulated M2-like macrophage activation in an inflammatory microenvironment and significantly induced interleukin (IL)-10 secretion, demonstrating their modulatory effect on inflammation. Administering EVs from untreated WJ-MSCs slightly improved lung function and increased let-7a-5p expression in plasma in the hyperoxia-induced ALI rat model. In comparison, EV-let-7a-5p significantly reduced macrophage infiltration and collagen deposition while increasing IL-10 expression, causing a substantial improvement in lung function.

CONCLUSION

This study reveals that the use of the CNP platform to stimulate and transfect WJ-MSCs could generate an abundance of let-7a-5p-enriched EVs, which underscores the therapeutic potential in countering inflammatory responses, fibrotic activation, and hyperoxia-induced lung injury. These results provide potential avenues for developing innovative therapeutic approaches for more effective interventions in ALI.

Macrophage-derived exosomal HMGB3 regulates silica-induced pulmonary inflammation by promoting M1 macrophage polarization and recruitment

BACKGROUND

Chronic inflammation and fibrosis are characteristics of silicosis, and the inflammatory mediators involved in silicosis have not been fully elucidated. Recently, macrophage-derived exosomes have been reported to be inflammatory modulators, but their role in silicosis has not been explored. The purpose of the present study was to investigate the role of macrophage-derived exosomal high mobility group box 3 (HMGB3) in silica-induced pulmonary inflammation.

METHODS

The induction of the inflammatory response and the recruitment of monocytes/macrophages were evaluated by immunofluorescence, flow cytometry and transwell assays. The expression of inflammatory cytokines was examined by RT-PCR and ELISA, and the signalling pathways involved were examined by western blot analysis.

RESULTS

HMGB3 expression was increased in exosomes derived from silica-exposed macrophages. Exosomal HMGB3 significantly upregulated the expression of inflammatory cytokines, activated the STAT3/MAPK (ERK1/2 and p38)/NF-κB pathways in monocytes/macrophages, and promoted the migration of these cells by CCR2.

CONCLUSIONS

Exosomal HMGB3 is a proinflammatory modulator of silica-induced inflammation that promotes the inflammatory response and recruitment of monocytes/macrophages by regulating the activation of the STAT3/MAPK/NF-κB/CCR2 pathways.

RHBDL4-triggered downregulation of COPII adaptor protein TMED7 suppresses TLR4-mediated inflammatory signaling

The toll-like receptor 4 (TLR4) is a central regulator of innate immunity that primarily recognizes bacterial lipopolysaccharide cell wall constituents to trigger cytokine secretion. We identify the intramembrane protease RHBDL4 as a negative regulator of TLR4 signaling. We show that RHBDL4 triggers degradation of TLR4's trafficking factor TMED7. This counteracts TLR4 transport to the cell surface. Notably, TLR4 activation mediates transcriptional upregulation of RHBDL4 thereby inducing a negative feedback loop to reduce TLR4 trafficking to the plasma membrane. This secretory cargo tuning mechanism prevents the over-activation of TLR4-dependent signaling in an in vitro Mycobacterium tuberculosis macrophage infection model and consequently alleviates septic shock in a mouse model. A hypomorphic RHBDL4 mutation linked to Kawasaki syndrome, an ill-defined inflammatory disorder in children, further supports the pathophysiological relevance of our findings. In this work, we identify an RHBDL4-mediated axis that acts as a rheostat to prevent over-activation of the TLR4 pathway.

Targeted knockdown of PGAM5 in synovial macrophages efficiently alleviates osteoarthritis

Osteoarthritis (OA) is a common degenerative disease worldwide and new therapeutics that target inflammation and the crosstalk between immunocytes and chondrocytes are being developed to prevent and treat OA. These attempts involve repolarizing pro-inflammatory M1 macrophages into the anti-inflammatory M2 phenotype in synovium. In this study, we found that phosphoglycerate mutase 5 (PGAM5) significantly increased in macrophages in OA synovium compared to controls based on histology of human samples and single-cell RNA sequencing results of mice models. To address the role of PGAM5 in macrophages in OA, we found conditional knockout of PGAM5 in macrophages greatly alleviated OA symptoms and promoted anabolic metabolism of chondrocytes in vitro and in vivo. Mechanistically, we found that PGAM5 enhanced M1 polarization via AKT-mTOR/p38/ERK pathways, whereas inhibited M2 polarization via STAT6-PPARγ pathway in murine bone marrow-derived macrophages. Furthermore, we found that PGAM5 directly dephosphorylated Dishevelled Segment Polarity Protein 2 (DVL2) which resulted in the inhibition of β-catenin and repolarization of M2 macrophages into M1 macrophages. Conditional knockout of both PGAM5 and β-catenin in macrophages significantly exacerbated osteoarthritis compared to PGAM5-deficient mice. Motivated by these findings, we successfully designed mannose modified fluoropolymers combined with siPGAM5 to inhibit PGAM5 specifically in synovial macrophages via intra-articular injection, which possessed desired targeting abilities of synovial macrophages and greatly attenuated murine osteoarthritis. Collectively, these findings defined a key role for PGAM5 in orchestrating macrophage polarization and provides insights into novel macrophage-targeted strategy for treating OA.

Identification of hypoxia- and immune-related biomarkers in patients with ischemic stroke

Background

The immune microenvironment and hypoxia play crucial roles in the pathophysiology of ischemic stroke (IS). Hence, in this study, we aimed to identify hypoxia- and immune-related biomarkers in IS.

Methods

The IS microarray dataset GSE16561 was examined to determine differentially expressed genes (DEGs) utilizing bioinformatics-based analysis. The intersection of hypoxia-related genes and DEGs was conducted to identify differentially expressed hypoxia-related genes (DEHRGs). Then, using weighted correlation network analysis (WGCNA), all of the genes in GSE16561 dataset were examined to create a co-expression network, and module-clinical trait correlations were examined for the purpose of examining the genes linked to immune cells. The immune-related DEHRGs were submitted to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. A protein-protein interaction (PPI) network was constructed by Cytoscape plugin MCODE, in order to extract hub genes. The miRNet was used to predict hub gene-related transcription factors (TFs) and miRNAs. Finally, a diagnostic model was developed by least absolute shrinkage and selection operator (LASSO) logistic regression.

Results

Between the control and IS samples, 4171 DEGs were found. Thereafter, the intersection of hypoxia-related genes and DEGs was conducted to obtain 45 DEHRGs. Ten significantly differentially infiltrated immune cells were found-namely, CD56dim natural killer cells, activated CD8 T cells, activated dendritic cells, activated B cells, central memory CD8 T cells, effector memory CD8 T cells, natural killer cells, gamma delta T cells, plasmacytoid dendritic cells, and neutrophils-between IS and control samples. Subsequently, we identified 27 immune-related DEHRGs through the intersection of DEHRGs and genes in important modules of WGCNA. The immune-related DEHRGs were primarily enriched in response to hypoxia, cellular polysaccharide metabolic process, response to decreased oxygen levels, polysaccharide metabolic process, lipid and atherosclerosis, and HIF-1 signaling pathway H. Using MCODE, FOS, DDIT3, DUSP1, and NFIL3 were found to be hub genes. In the validation cohort and training set, the AUC values of the diagnostic model were 0.9188034 and 0.9395085, respectively.

Conclusion

In brief, we identified and validated four hub genes-FOS, DDIT3, DUSP1, and NFIL3-which might be involved in the pathological development of IS, potentially providing novel perspectives for the diagnosis and treatment of IS.

Effects of lysine deacetylase inhibitor treatment on LPS responses of alveolar-like macrophages

Macrophages are key immune cells that can adapt their metabolic phenotype in response to different stimuli. Lysine deacetylases are important enzymes regulating inflammatory gene expression and lysine deacetylase inhibitors have been shown to exert anti-inflammatory effects in models of chronic obstructive pulmonary disease. We hypothesized that these anti-inflammatory effects may be associated with metabolic changes in macrophages. To validate this hypothesis, we used an unbiased and a targeted proteomic approach to investigate metabolic enzymes, as well as liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry, to quantify metabolites in combination with the measurement of functional parameters in primary murine alveolar-like macrophages after lipopolysaccharide-induced activation in the presence or absence of lysine deacetylase inhibition. We found that lysine deacetylase inhibition resulted in reduced production of inflammatory mediators such as tumor necrosis factor α and interleukin 1β. However, only minor changes in macrophage metabolism were observed, as only one of the lysine deacetylase inhibitors slightly increased mitochondrial respiration while no changes in metabolite levels were seen. However, lysine deacetylase inhibition specifically enhanced expression of proteins involved in ubiquitination, which may be a driver of the anti-inflammatory effects of lysine deacetylase inhibitors. Our data illustrate that a multiomics approach provides novel insights into how macrophages interact with cues from their environment. More detailed studies investigating ubiquitination as a potential driver of lysine deacetylase inhibition will help developing novel anti-inflammatory drugs for difficult-to-treat diseases such as chronic obstructive pulmonary disease.

Caffeic acid derivative WSY6 protects melanocytes from oxidative stress by reducing ROS production and MAPK activation

Purpose

Vitiligo is a chronic depigmentation disease caused by a loss of functioning melanocytes and melanin from the epidermis. Oxidative stress-induced damage to melanocytes is key in the pathogenesis of vitiligo. WSY6 is a caffeic acid derivative synthesized from epigallocatechin-3-gallate (EGCG). This study is to investigate whether the new chemical WSY6 protected melanocytes from H2O2-induced cell damage and to elucidate the underlying molecular mechanism.

Patients and methods

The present study compared the antioxidative potential of WSY6 with EGCG in hydrogen peroxide (H2O2)-treated PIG1 cells. Western blotting was used to study the protein expression of cyto-c, cleaved-caspase3, cleaved-caspase9, and the activation of MAPK family members, including p38, ERK1/2, JNK and their phosphorylation in melanocytes. ROS assay kit to detect intracellular reactive oxygen species production; CCK8 and lactate dehydrogenase leak assay to detect cytotoxicity.

Results

EGCG and WSY6 ameliorated H2O2-induced oxidative stress damage in PIG1 cells in a does-dependent manner, while WSY6 was much more effective. WSY6 reduced cellular ROS production, cytochrome c release, downregulated caspase-3 and caspase-9 activation. MAPK pathway signaling including phosphorylated p38, ERK and JNK were observed under oxidative stress and can be much protected by pre-treatment of WSY6.

Conclusion

These results indicated that WSY6 could be a more powerful antioxidant than EGCG and protect melanocytes against oxidative cytotoxicity.

Qingfei Formula Protects against Human Respiratory Syn cytial Virus-induced Lung Inflammatory Injury by Regulating the M APK Signaling Pathway

OBJECTIVE

Qingfei formula (QF) is an empirical formula that shows good clinical efficacy in treating human respiratory syncytial virus pneumonia (RSVP). However, the underlying mechanism remains unclear. This study explores the possible pharmacological actions of QF in RSVP treatment.

METHODS

We used a network pharmacology approach to identify the active ingredients of QF, forecast possible therapeutic targets, and analyze biological processes and pathways. Molecular docking simulation was used to evaluate the binding capability of active ingredients and therapeutic targets. Finally, in vivo experiments confirmed the reliability of network pharmacology-based prediction of underlying mechanisms.

RESULTS

The study identified 92 potential therapeutic targets and corresponding 131 active ingredients. Enrichment analysis showed that QF downregulated the MAPK signaling pathway and suppressed the inflammatory injury to the lungs induced by the RSV virus. Molecular docking simulations demonstrated that the core active ingredients of QF could stably bind to genes associated with the MAPK signaling pathway. QF had a protective effect against pneumonia in RSV-infected mice. The QF group exhibited a significant reduction in the levels of inflammatory mediators, interleukin- 6 (IL-6), interleukin-8 (CXCL8, IL-8), and P-STAT3, compared to the RSV-induced group. The QF group showed remarkably inhibited MAPK1+3(P-ERK1+2) and MAPK8(P-JNK) protein expression.

CONCLUSION

The current study showed that QF downregulated the MAPK signaling pathway, which inhibited pulmonary inflammation triggered by RSV infection. This study recommends the appropriate use of QF in the clinical management of RSVP.

The Potential Role of Probiotics in the Management of Osteoarthritis Pain: Current Status and Future Prospects

PURPOSE OF REVIEW

This narrative review article comprehensively explains the pathophysiology of osteoarthritis (OA) pain perception, how the gut microbiota is correlated with it, possible molecular pathways involved in probiotics-mediated OA pain reduction, limitations in the current research approaches, and future perspectives.

RECENT FINDINGS

The initiation and progression of OA, including the development of chronic pain, is intricately associated with activation of the innate immune system and subsequent inflammatory responses. Trauma, lifestyle (e.g., obesity and metabolic disease), and chronic antibiotic treatment can disrupt commensal homeostasis of the human microbiome, thereby affecting intestinal integrity and promoting leakage of bacterial endotoxins and metabolites such as lipopolysaccharides (LPS) into circulation. Increased level of LPS is associated with knee osteophyte severity and joint pain. Both preclinical and clinical studies strongly suggest that probiotics may benefit patients with OA pain through positive gut microbiota modulation and attenuating low-grade inflammation via multiple pathways. Patent data also suggests increased interest in the development of new innovations that involve probiotic use for reducing OA and joint pain. Recent data suggest that probiotics are attracting more and more attention for OA pain management. The advancement of knowledge in this area may pave the way for developing different probiotic strains that can be used to support joint health, improve treatment outcomes in OA, and reduce the huge impact of the disease on healthcare systems worldwide.

Remodeling periodontal osteoimmune microenvironment through MAPK/NFκB phosphorylation pathway of macrophage via intelligent ROS scavenging

Periodontitis is an inflammatory disorder which leads to the defect of tooth-supporting tissue, especially in alveolar bone. During this process, the polarization behavior of macrophages affects immune inflammation and bone regeneration in which reactive oxygen species (ROS) play an essential role. ROS level should be regulated to the physiological level to protect stem cells from the inflammatory immune microenvironment. Our previous study constructed a ROS-responsive nanoplatform (Pssl-NAC), which possessed ROS-responsive antioxidative effect and could be potentially applied in periodontitis. However, the connection among bone regeneration, inflammation and oxidative stress remained in osteoimmune regulation is not clear. To further investigate the mechanism of the way how Pssl-NAC works in the treatment of periodontitis would be meaningful. Here, we investigated the effect of PssL-NAC in the regulation of the osteoimmune microenvironment through macrophage polarization. Results show PssL-NAC regulated the macrophage polarization direction in an inflammatory environment by maintaining an appropriate level of intracellular ROS, in which the MAPK/NFκB phosphorylation pathway is particularly important. In the macrophage-human periodontal ligament stem cells (hPDLSCs) co-culture system, PssL-NAC treatment significantly enhanced the osteogenic differentiation of hPDLSCs. In vivo experiment further confirmed the M2-like macrophages increased in the periodontal tissue of rats, and the expression of iNOS and p65 decreased after PssL-NAC treatment. In conclusion, PssL-NAC regulates the osteoimmune microenvironment and protects stem cells from oxidative stress injury for bone regeneration, which provides a strategy for the treatment of periodontitis.

Inhibition of STAT-mediated cytokine responses to chemically-induced colitis prevents inflammation-associated neurobehavioral impairments

Depression can be associated with chronic systemic inflammation, and production of peripheral proinflammatory cytokines and upregulation of the kynurenine pathway have been implicated in pathogenesis of depression. However, the mechanistic bases for these comorbidities are not yet well understood. As tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO), which convert tryptophan to kynurenine, are rate-limiting enzymes of the kynurenine pathway, we screened TDO or IDO inhibitors for effects on the production of proinflammatory cytokines in a mouse macrophage cell line. The TDO inhibitor 680C91 attenuated LPS-induced pro-inflammatory cytokines including IL-1β and IL-6. Surprisingly, this effect was TDO-independent, as it occurred even in peritoneal macrophages from TDO knockout mice. Instead, the anti-inflammatory effects of 680C91 were mediated through the suppression of signal transducer and activator of transcription(STAT) signaling. Furthermore, 680C91 suppressed production of proinflammatory cytokines and STAT signaling in an animal model of inflammatory bowel disease. Specifically, 680C91 effectively attenuated acute phase colon cytokine responses in male mice subjected to dextran sulfate sodium (DSS)-induced colitis. Interestingly, this treatment also prevented the development of anxiodepressive-like neurobehaviors in DSS-treated mice during the recovery phase. The ability of 680C91 to prevent anxiodepressive-like behavior in response to chemically-induced colitis appeared to be due to rescue of attenuated dopamine responses in the nucleus accumbens. Thus, inhibition of STAT-mediated, but TDO-independent proinflammatory cytokines in macrophages can prevent inflammation-associated anxiety and depression. Identification of molecular mechanisms involved may facilitate the development of new treatments for gastrointestinal-neuropsychiatric comorbidity.

Do macrophages play a role in the adverse effects of endocrine disrupting chemicals (EDCs) on testicular functions?

During the past decades, several endocrine disrupting chemicals (EDCs) have been confirmed to affect male reproductive function and fertility in animal studies. EDCs are suspected to exert similar effects in humans, based on strong associations between levels of antiandrogenic EDCs in pregnant women and adverse reproductive effects in infants. Testicular macrophages (tMΦ) play a vital role in modulating immunological privilege and maintaining normal testicular homeostasis as well as fetal development. Although tMΦ were not historically studied in the context of endocrine disruption, they have emerged as potential targets to consider due to their critical role in regulating cells such as spermatogonial stem cells (SSCs) and Leydig cells. Few studies have examined the impact of EDCs on the ability of testicular cells to communicate and regulate each other's functions. In this review, we recapitulate what is known about tMΦ functions and interactions with other cell types in the testis that support spermatogenesis and steroidogenesis. We also surveyed the literature for reports on the effects of the EDCs genistein and DEHP on tMΦ, SSCs, Sertoli and Leydig cells. Our goal is to explore the possibility that EDC disruption of tMΦ interactions with other cell types may play a role in their adverse effects on testicular developmental programming and functions. This approach will highlight gaps of knowledge, which, once resolved, should improve the risk assessment of EDC exposure and the development of safeguards to protect male reproductive functions.

Protein tyrosine phosphatase non-receptor type 2 as the therapeutic target of atherosclerotic diseases: past, present and future

Tyrosine-protein phosphatase non-receptor type 2(PTPN2), an important member of the protein tyrosine phosphatase family, can regulate various signaling pathways and biological processes by dephosphorylating receptor protein tyrosine kinases. Accumulating evidence has demonstrated that PTPN2 is involved in the occurrence and development of atherosclerotic cardiovascular disease. Recently, it has been reported that PTPN2 exerts an anti-atherosclerotic effect by regulating vascular endothelial injury, monocyte proliferation and migration, macrophage polarization, T cell polarization, autophagy, pyroptosis, and insulin resistance. In this review, we summarize the latest findings on the role of PTPN2 in the pathogenesis of atherosclerosis to provide a rationale for better future research and therapeutic interventions.

Paired single-cell host profiling with multiplex-tagged bacterial mutants reveals intracellular virulence-immune networks

Encounters between host cells and intracellular bacterial pathogens lead to complex phenotypes that determine the outcome of infection. Single-cell RNA sequencing (scRNA-seq) is increasingly used to study the host factors underlying diverse cellular phenotypes but has limited capacity to analyze the role of bacterial factors. Here, we developed scPAIR-seq, a single-cell approach to analyze infection with a pooled library of multiplex-tagged, barcoded bacterial mutants. Infected host cells and barcodes of intracellular bacterial mutants are both captured by scRNA-seq to functionally analyze mutant-dependent changes in host transcriptomes. We applied scPAIR-seq to macrophages infected with a library of Salmonella Typhimurium secretion system effector mutants. We analyzed redundancy between effectors and mutant-specific unique fingerprints and mapped the global virulence network of each individual effector by its impact on host immune pathways. ScPAIR-seq is a powerful tool to untangle bacterial virulence strategies and their complex interplay with host defense strategies that drive infection outcome.

System Biology Investigation Revealed Lipopolysaccharide and Alcohol-Induced Hepatocellular Carcinoma Resembled Hepatitis B Virus Immunobiology and Pathogenesis

Hepatitis B infection caused by the hepatitis B virus is a life-threatening cause of liver fibrosis, cirrhosis, and hepatocellular carcinoma. Researchers have produced multiple in vivo models for hepatitis B virus (HBV) and, currently, there are no specific laboratory animal models available to study HBV pathogenesis or immune response; nonetheless, their limitations prevent them from being used to study HBV pathogenesis, immune response, or therapeutic methods because HBV can only infect humans and chimpanzees. The current study is the first of its kind to identify a suitable chemically induced liver cirrhosis/HCC model that parallels HBV pathophysiology. Initially, data from the peer-reviewed literature and the GeneCards database were compiled to identify the genes that HBV and seven drugs (acetaminophen, isoniazid, alcohol, D-galactosamine, lipopolysaccharide, thioacetamide, and rifampicin) regulate. Functional enrichment analysis was performed in the STRING server. The network HBV/Chemical, genes, and pathways were constructed by Cytoscape 3.6.1. About 1546 genes were modulated by HBV, of which 25.2% and 17.6% of the genes were common for alcohol and lipopolysaccharide-induced hepatitis. In accordance with the enrichment analysis, HBV activates the signaling pathways for apoptosis, cell cycle, PI3K-Akt, TNF, JAK-STAT, MAPK, chemokines, NF-kappa B, and TGF-beta. In addition, alcohol and lipopolysaccharide significantly activated these pathways more than other chemicals, with higher gene counts and lower FDR scores. In conclusion, alcohol-induced hepatitis could be a suitable model to study chronic HBV infection and lipopolysaccharide-induced hepatitis for an acute inflammatory response to HBV.

Detailed metabolite profiling and in vitro studies of Urospermum picroides as a potential functional food

Wild edible plants (WEP) are part of the Mediterranean culinary culture and can be used as famine foods in times of severe food shortages. Urospermum picroides is a WEP that grows under harsh conditions and represents an opportunity to expand and diversify the global food supply. However, little is known about its chemical profile. In this study, liquid chromatography coupled to HRESIMS allowed the identification of 77 metabolites in U. picroides extract, among which 12 sesquiterpene-amino acid conjugates are reported here for the first time. Due to the novelty of these conjugates, GNPS molecular networking was used to provide information on their fragmentation pathway. Further, the sesquiterpene enriched U. picroides extract showed a moderate anti-inflammatory effect in LPS-stimulated THP1-macrophages by increasing IL-10 secretion while decreasing pro-inflammatory IL-6 secretion at 50 µg/mL. Our study provides evidence for the potential use of U. picroides as an anti-inflammatory functional food and nutraceutical agent.

Network pharmacology and bioinformatics analysis identifies potential therapeutic targets of Naringenin against COVID-19/LUSC

Background

Coronavirus disease 2019 (COVID-19) is a highly contagious respiratory disease that has posed a serious threat to people's daily lives and caused an unprecedented challenge to public health and people's health worldwide. Lung squamous cell carcinoma (LUSC) is a common type of lung malignancy with a highly aggressive nature and poor prognosis. Patients with LUSC could be at risk for COVID-19, We conducted this study to examine the potential for naringenin to develop into an ideal medicine and investigate the underlying action mechanisms of naringenin in COVID-19 and LUSC due to the anti-viral, anti-tumor, and anti-inflammatory activities of naringenin.

Methods

LUSC related genes were obtained from TCGA, PharmGKB, TTD,GeneCards and NCBI, and then the transcriptome data for COVID-19 was downloaded from GEO, DisGeNET, CTD, DrugBank, PubChem, TTD, NCBI Gene, OMIM. The drug targets of Naringenin were revealed through CTD, BATMAN, TCMIP, SymMap, Chemical Association Networks, SwissTargetPrediction, PharmMapper, ECTM, and DGIdb. The genes related to susceptibility to COVID-19 in LUSC patients were obtained through differential analysis. The interaction of COVID-19/LUSC related genes was evaluated and demonstrated using STRING to develop a a COX risk regression model to screen and evaluate the association of genes with clinical characteristics. To investigate the related functional and pathway analysis of the common targets of COVID-19/LUSC and Naringenin, KEGG and GO enrichment analysis were employed to perform the functional analysis of the target genes. Finally, The Hub Gene was screened and visualized using Cytoscape, and molecular docking between the drug and the target was performed using Autodock.

Results

We discovered numerous COVID-19/LUSC target genes and examined their prognostic value in LUSC patients utilizing a variety of bioinformatics and network pharmacology methods. Furthermore, a risk score model with strong predictive performance was developed based on these target genes to assess the prognosis of LUSC patients with COVID-19. We intersected the therapeutic target genes of naringenin with the LUSC, COVID-19-related targets, and identified 354 common targets, which could be used as potential target genes for naringenin to treat COVID-19/LUSC. The treatment of COVID-19/LUSC with naringenin may involve oxidative stress, anti-inflammatory, antiviral, antiviral, apoptosis, immunological, and multiple pathways containing PI3K-Akt, HIF-1, and VEGF, according to the results of the GO and KEGG enrichment analysis of these 354 common targets. By constructing a PPI network, we ascertained AKT1, TP53, SRC, MAPK1, MAPK3, and HSP90AA1 as possible hub targets of naringenin for the treatment of COVID-19/LUSC. Last but not least, molecular docking investigations showed that naringenin has strong binding activity in COVID-19/LUSC.

Conclusion

We revealed for the first time the pharmacological targets and potential molecular processes of naringenin for the treatment of COVID-19/LUSC. However, these results need to be confirmed by additional research and validation in real LUSC patients with COVID-19.

Transient Receptor Vanilloid Subtype 4-Mediated Ca2+ Influx Promotes Glomerular Endothelial Inflammation in Sepsis-Associated Acute Kidney Injury

Sepsis-associated acute kidney injury (S-AKI) is a frequent complication in patients who are critically ill, which is often initiated by glomerular endothelial cell dysfunction. Although transient receptor vanilloid subtype 4 (TRPV4) ion channels are known to be permeable to Ca2+ and are widely expressed in the kidneys, the role of TRPV4 on glomerular endothelial inflammation in sepsis remains elusive. In the present study, we found that TRPV4 expression in mouse glomerular endothelial cells (MGECs) increased after lipopolysaccharide (LPS) stimulation or cecal ligation and puncture challenge, which increased intracellular Ca2+ in MGECs. Furthermore, the inhibition or knockdown of TRPV4 suppressed LPS-induced phosphorylation and translocation of inflammatory transcription factors NF-κB and IRF-3 in MGECs. Clamping intracellular Ca2+ mimicked LPS-induced responses observed in the absence of TRPV4. In vivo experiments showed that the pharmacologic blockade or knockdown of TRPV4 reduced glomerular endothelial inflammatory responses, increased survival rate, and improved renal function in cecal ligation and puncture-induced sepsis without altering renal cortical blood perfusion. Taken together, our results suggest that TRPV4 promotes glomerular endothelial inflammation in S-AKI and that its inhibition or knockdown alleviates glomerular endothelial inflammation by reducing Ca2+ overload and NF-κB/IRF-3 activation. These findings provide insights that may aid in the development of novel pharmacologic strategies for the treatment of S-AKI.

Magnoflorine Ameliorates Collagen-Induced Arthritis by Suppressing the Inflammation Response via the NF-κB/MAPK Signaling Pathways

Objective

Magnoflorine (Mag) has been reported to have anxiolytics, anti-cancer, and anti-inflammatory properties. In this study, we aim to investigate the effects of Mag on the rheumatoid arthritis (RA) and explore the underlying mechanism using a collagen-induced arthritis (CIA) mouse model and a lipopolysaccharide (LPS)-stimulated macrophage inflammation model.

Methods

The in vivo effects of Mag on CIA were studied by inducing CIA in a mouse model using DBA/1J mice followed by treatment with vehicle, methotrexate (MTX, 1 mg/kg/d), and Mag (5 mg/kg/d, 10 mg/kg/d, and 20 mg/kg/d), and the in vitro effects of Mag on macrophages were examined by stimulation of RAW264.7 cells line and peritoneal macrophages (PMs) by LPS in the presence of different concentrations of Mag. Network pharmacology and molecular docking was then performed to predict the the binding ability between Mag and its targets. Inflammatory mediators were assayed by quantitative real-time PCR and enzyme linked immunosorbent assay (ELISA). Signaling pathway changes were subsequently determined by Western blotting and immunohistochemistry (IHC).

Results

In vivo experiments demonstrated that Mag decreased arthritis severity scores, joints destruction, and macrophages infiltration into the synovial tissues of the CIA mice. Network pharmacology analysis revealed that Mag interacted with TNF-α, IL-6, IL-1β, and MCP-1. Consistent with this, analysis of the serum, synovial tissue of the CIA mice, and the supernatant of the cultured RAW264.7 cells and PMs showed that Mag suppressed the expression of TNF-α, IL-6, IL-1β, MCP-1, iNOS, and IFN-β. Furthermore, Mag attenuated the phosphorylation of p65, IκBα, ERK, JNK, and p38 MAPKs in the synovial tissues of the CIA mice and LPS-stimulated RAW 264.7 cells.

Conclusion

Mag may exert anti-arthritic and anti-inflammatory effects by inhibiting the activation of NF-κB and MAPK signaling pathways.

Protective Effect of Glycomacropeptide on the Inflammatory Response of U937 Macrophages

Macrophages play crucial roles in inflammation and oxidative stress associated with noncommunicable diseases, such as cardiovascular diseases, diabetes, and cancer. Glycomacropeptide (GMP) is a bioactive peptide derived from milk κ-casein that contains abundant sialic acid and has shown anti-inflammatory, antioxidative, anti-obesity, and anti-diabetic properties when is orally administered. The aim of this study was to evaluate the effect of GMP on the regulation of the inflammatory response in human macrophages and the participation of sialic acid in this activity. GMP pretreatment decreased by 35%, 35%, and 49% the production of nitrites, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α, respectively, in activated human macrophages U937. The same effect was obtained when cells were pretreated with asialo GMP, and no change on the gene expression of the lectins associated with the recognition of sialic acids, SIGLEC5, 7, and 9, was induced by GMP on macrophages, which suggests that sialic acid might not be involved in this immunoregulatory effect. Interestingly, GMP increased 8.9- and 3.5-fold the gene expression of the canonical anti-inflammatory protein SOCS3 and the antioxidant enzyme HMOX1, respectively, in U937 cells. Thus, GMP exerts anti-inflammatory and antioxidative activities on activated macrophages in a sialic acid-independent manner, which might be related to its in vivo reported bioactivity.

N6-Methyladenosine and Reader Protein YTHDF2 Enhance the Innate Immune Response by Mediating DUSP1 mRNA Degradation and Activating Mitogen-Activated Protein Kinases during Bacterial and Viral Infections

Mitogen-activated protein kinases (MAPKs) play critical roles in the induction of numerous cytokines, chemokines, and inflammatory mediators that mobilize the immune system to counter pathogenic infections. Dual-specificity phosphatase 1 (DUSP1) is a member of the dual-specificity phosphatases that inactivates MAPKs through a negative-feedback mechanism. Here, we report that in response to viral and bacterial infections, not only the DUSP1 transcript but also its N6-methyladenosine (m6A) levels rapidly increase together with that of the m6A reader protein YTHDF2, resulting in enhanced YTHDF2-mediated DUSP1 transcript degradation. The knockdown of DUSP1 promotes p38 and Jun N-terminal kinase (JNK) phosphorylation and activation, thus increasing the expression of innate immune response genes, including the interleukin-1β (IL-1β), colony-stimulating factor 3 (CSF3), transglutaminase 2 (TGM2), and proto-oncogene tyrosine-protein kinase Src (SRC) genes. Similarly, the knockdown of the m6A eraser ALKBH5 increases the DUSP1 transcript m6A level, resulting in accelerated transcript degradation, the activation of p38 and JNK, and the enhanced expression of IL-1β, CSF3, TGM2, and SRC. These results demonstrate that m6A and the reader protein YTHDF2 orchestrate optimal innate immune responses during viral and bacterial infections by downregulating the expression of a negative regulator, DUSP1, of the p38 and JNK pathways that are central to innate immune responses against pathogenic infections. IMPORTANCE Innate immunity is central to controlling pathogenic infections and maintaining the homeostasis of the host. In this study, we have revealed a novel mechanism regulating innate immune responses during viral and bacterial infections. We have found that N6-methyladenosine (m6A) and the reader protein YTHDF2 regulate dual-specificity phosphatase 1, a negative regulator of the mitogen-activated protein kinases p38 and JNK, to maximize innate immune responses during viral and bacterial infections. These results provide novel insights into the mechanism regulating innate immunity, which could help in the development of novel approaches for controlling pathogenic infections.

Advances in the role of STAT3 in macrophage polarization

The physiological processes of cell growth, proliferation, differentiation, and apoptosis are closely related to STAT3, and it has been demonstrated that aberrant STAT3 expression has an impact on the onset and progression of a number of inflammatory immunological disorders, fibrotic diseases, and malignancies. In order to produce the necessary biological effects, macrophages (M0) can be polarized into pro-inflammatory (M1) and anti-inflammatory (M2) types in response to various microenvironmental stimuli. STAT3 signaling is involved in macrophage polarization, and the research of the effect of STAT3 on macrophage polarization has gained attention in recent years. In order to provide references for the treatment and investigation of disorders related to macrophage polarization, this review compiles the pertinent signaling pathways associated with STAT3 and macrophage polarization from many fundamental studies.

Ntrk1 promotes mesangial cell proliferation and inflammation in rat glomerulonephritis model by activating the STAT3 and p38/ERK MAPK signaling pathways

BACKGROUND

Mesangial proliferative glomerulonephritis (MsPGN) accounts for a main cause of chronic kidney disease (CKD), chronic renal failure and uremia. This paper aimed to examine the effect of Ntrk1 on MsPGN development, so as to identify a novel therapeutic target for MsPGN.

METHODS

The MsPGN rat model was constructed by single injection of Thy1.1 monoclonal antibody via the tail vein. Additionally, the Ntrk1 knockdown rat model was established by injection of Ntrk1-RNAi lentivirus via the tail vein. Periodic acid-schiff staining and immunohistochemistry (IHC) were performed on kidney tissues. Moreover, the rat urinary protein was detected. Mesangial cells were transfected and treated with p38 inhibitor (SB202190) and ERK inhibitor (PD98059). Meanwhile, the viability and proliferation of mesangial cells were analyzed by cell counting kit-8 (CCK-8) and 5-Ethynyl-2'-deoxyuridine assays. Gene expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western-blot (WB) assays.

RESULTS

The proliferation of mesangial cells was enhanced in glomerulus and Ki67 expression was up-regulated in renal tubule of MsPGN rats. The urine protein level increased in MsPGN rats. Pro-inflammatory factors and Ntrk1 expression were up-regulated in glomerulus of MsPGN rats. Ntrk1 up-regulation promoted the viability, proliferation, expression of pro-inflammatory factors and activation of the STAT3, p38 and ERK signaling pathways in mesangial cells. Ntrk1 knockdown reduced mesangial cell proliferation, urine protein, pro-inflammatory factors, activation of STAT3, p38 and ERK signaling pathways in glomerulus, and decreased Ki67 expression in renal tubule of MsPGN rats. Treatment with SB202190 and PD98059 reversed the effect of Ntrk1 on promoting the viability, proliferation and inflammatory response of mesangial cells.

CONCLUSION

Ntrk1 promoted mesangial cell proliferation and inflammation in MsPGN rats by activating the STAT3 and p38/ERK MAPK signaling pathways.

Multi-Omics Integration to Reveal the Mechanism of Sericin Inhibiting LPS-Induced Inflammation

Sericin is a natural protein with high application potential, but the research on its efficacy is very limited. In this study, the anti-inflammatory mechanism of sericin protein was investigated. Firstly, the protein composition of sericin extracts was determined by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). This was then combined with Enzyme-linked Immunosorbent Assay (ELISA) and Quantitative Real-time PCR (qRT-PCR), and it was confirmed that the anti-inflammation ability of sericin was positively correlated with the purity of sericin 1 protein. Finally, RNA-seq was performed to quantify the inhibitory capacity of sericin sample SS2 in LPS-stimulated macrophages. The gene functional annotation showed that SS2 suppressed almost all PRRs signaling pathways activated by lipopolysaccharides (LPS), such as the Toll-like receptors (TLRs) and NOD-like receptors (NLRs) signaling pathways. The expression level of adaptor gene MyD88 and receptor gene NOD1 was significantly down-regulated after SS2 treatment. SS2 also reduced the phosphorylation levels of NF-κB P65, P38, and JNK, thereby reducing the expressions of IL-1β, IL-6, INOS, and other inflammatory cytokines. It was confirmed that sericin inhibited LPS-induced inflammation through MyD88/NF-κB pathway. This finding provides necessary theoretical support for sericin development and application.

The Patatin-Like Phospholipase Domain Containing Protein 7 Regulates Macrophage Classical Activation through SIRT1/NF-κB and p38 MAPK Pathways

Lysophosphatidylcholine (LPC) is a bioactive lipid that modulates macrophage polarization during immune responses, inflammation, and tissue remodeling. Patatin-like phospholipase domain containing protein 7 (PNPLA7) is a lysophospholipase with a preference for LPC. However, the role of PNPLA7 in macrophage polarization as an LPC hydrolase has not been explored. In the current study, we found that PNPLA7 is highly expressed in naïve macrophages and downregulated upon lipopolysaccharide (LPS)-induced polarization towards the classically activated (M1) phenotype. Consistently, overexpression of PNPLA7 suppressed the expression of proinflammatory M1 marker genes, including interleukin 1β (IL-1β), IL-6, inducible nitric oxide synthase (iNOS), and tumor necrosis factor α (TNF-α), whereas knockdown of PNPLA7 augmented the inflammatory gene expression in LPS-challenged macrophages. PNPLA7 overexpression and knockdown increased and decreased Sirtuin1 (SIRT1) mRNA and protein levels, respectively, and affected the acetylation of the nuclear factor-kappa B (NF-κB) p65 subunit, a key transcription factor in M1 polarization. In addition, the levels of phosphorylated p38 mitogen-activated protein kinase (MAPK) were suppressed and enhanced by PNPLA7 overexpression and knockdown, respectively. Taken together, these findings suggest that PNPLA7 suppresses M1 polarization of LPS-challenged macrophages by modulating SIRT1/NF-κB- and p38 MAPK-dependent pathways.

Involvement of the p38 MAPK-NLRC4-Caspase-1 Pathway in Ionizing Radiation-Enhanced Macrophage IL-1β Production

Macrophages are abundant immune cells in the tumor microenvironment and are crucial in regulating tumor malignancy. We previously reported that ionizing radiation (IR) increases the production of interleukin (IL)-1β in lipopolysaccharide (LPS)-treated macrophages, contributing to the malignancy of colorectal cancer cells; however, the mechanism remained unclear. Here, we show that IR increases the activity of cysteine-aspartate-specific protease 1 (caspase-1), which is regulated by the inflammasome, and cleaves premature IL-1β to mature IL-1β in RAW264.7 macrophages. Irradiated RAW264.7 cells showed increased expression of NLRC4 inflammasome, which controls the activity of caspase-1 and IL-1β production. Silencing of NLRC4 using RNA interference inhibited the IR-induced increase in IL-1β production. Activation of the inflammasome can be regulated by mitogen-activated protein kinase (MAPK)s in macrophages. In RAW264.7 cells, IR increased the phosphorylation of p38 MAPK but not extracellular signal-regulated kinase and c-Jun N-terminal kinase. Moreover, a selective inhibitor of p38 MAPK inhibited LPS-induced IL-1β production and NLRC4 inflammasome expression in irradiated RAW264.7 macrophages. Our results indicate that IR-induced activation of the p38 MAPK-NLRC4-caspase-1 activation pathway in macrophages increases IL-1β production in response to LPS.

Anti‑inflammatory effects of Nypa fruticans Wurmb via NF‑κB and MAPK signaling pathways in macrophages

The inflammatory defense response of macrophages is a natural protective reaction in the immune system. Antioxidant and anti-inflammatory activities are closely related. In addition, the cell signaling pathway regulating inflammation is associated with MAPK and NF-κB signaling pathway phosphorylation. The present study aimed to evaluate whether the ethyl acetate fraction from N. fruticans (ENF) has a modulatory role in the MAPK signaling pathway and inhibition of the IκB/NF-κB signaling pathways, including translocation of NF-κB p65. Antioxidant and anti-inflammatory activities are closely related. In addition, the cell signaling pathway regulating inflammation is associated with MAPK and NF-κB signaling pathway phosphorylation. The results revealed that ENF exhibited antioxidant capacity, attenuated the cytokine levels and blocked nitric oxide production. ENF downregulated cyclooxygenase-2 and inducible nitric oxide synthase expression. We hypothesized that ENF treatment alleviated the various proinflammatory mediators via IκB phosphorylation and transcription of NF-κB compared with the untreated control. In conclusion, the present study demonstrated that the inhibitory effect of ENF treatment was attributed to the inhibition of MAPK and Akt/IκB/NF-κB signaling pathways.

Major pathways involved in macrophage polarization in cancer

Macrophages play an important role in tissue homeostasis, tissue remodeling, immune response, and progression of cancer. Consequently, macrophages exhibit significant plasticity and change their transcriptional profile and function in response to environmental, tissue, and inflammatory stimuli resulting in pro- and anti-tumor effects. Furthermore, the categorization of tissue macrophages in inflammatory situations remains difficult; however, there is an agreement that macrophages are predominantly polarized into two different subtypes with pro- and anti-inflammatory properties, the so-called M1-like and M2-like macrophages, respectively. These two macrophage classes can be considered as the extreme borders of a continuum of many intermediate subsets. On one end, M1 are pro-inflammatory macrophages that initiate an immunological response, damage tissue integrity, and dampen tumor progression by fostering robust T and natural killer (NK) cell anti-tumoral responses. On the other end, M2 are anti-inflammatory macrophages involved in tissue remodeling and tumor growth, that promote cancer cell proliferation, invasion, tumor metastasis, angiogenesis and that participate to immune suppression. These decisive roles in tumor progression occur through the secretion of cytokines, chemokines, growth factors, and matrix metalloproteases, as well as by the expression of immune checkpoint receptors in the case of M2 macrophages. Moreover, macrophage plasticity is supported by stimuli from the Tumor Microenvironment (TME) that are relayed to the nucleus through membrane receptors and signaling pathways that result in gene expression reprogramming in macrophages, thus giving rise to different macrophage polarization outcomes. In this review, we will focus on the main signaling pathways involved in macrophage polarization that are activated upon ligand-receptor recognition and in the presence of other immunomodulatory molecules in cancer.

YTHDF2 Regulates Macrophage Polarization through NF-κB and MAPK Signaling Pathway Inhibition or p53 Degradation

Macrophages are heterogeneous cells that can be polarized into M1 or M2 phenotype. m⁶A “reader” YTH domain family protein 2 (YTHDF2) has been the m⁶A binding protein with the highest activity, which can recognize and disturb m⁶A-containing mRNA in processing bodies to reduce mRNA stability. YTHDF2 is recently identified as an effective RNA binding protein that modulates inflammatory gene levels within inflammatory responses. However, the role of YTHDF2 in M1/M2 macrophage polarization has not been reported. We established a M1/M2 macrophage polarization model using bone-marrow-derived macrophages and found that the expression levels of YTHDF2 in M1/M2 macrophages were both elevated. YTHDF2-knockdown macrophage polarization model was then established, and through qPCR, ELISA, and FACS, we discovered that suppressing YTHDF2 encouraged M1 polarization but restrained M2 polarization. In M1 macrophages, YTHDF2 silencing had no significant effect on p53 expression; however, in YTHDF2 knockdown, M2 macrophage p53 expression was remarkably upregulated. p53 inhibitor PFT-α was then applied and revealed that suppressing p53 simultaneously promoted YTHDF2-silenced M1 polarization and facilitated M2 macrophage polarization. Actinomycin D assays were further utilized to examine the mRNA degradation level of different cytokines, and p53 mRNA degradation in YTHDF2-depleted M2 cells was discovered impeded. Western Blot analysis also implied that a deficit in YTHDF2 expression may activate MAPK and NF-κB pathways. In this study, YTHDF2 induces M2 macrophage polarization by promoting the degradation of p53 mRNA. YTHDF2 suppresses M1 macrophage polarization by inhibiting NF-κB, p38, and JNK signaling pathways, yet p53 remains unaffected in YTHDF2-silenced M1 macrophages.

Network pharmacology study to reveal active compounds of Qinggan Yin formula against pulmonary inflammation by inhibiting MAPK activation

ETHNOPHARMACOLOGICAL RELEVANCE

Pneumonia is common and frequently-occurred disease caused by pathogens which predisposes to lung parenchymal inflammation leading pulmonary dysfunction. To prevent and alleviate the symptoms of pneumonia, Qinggan Yin formula (QGY) was composed based on clinical experience and four classical traditional Chinese medicine prescriptions which frequently applied to treat infectious diseases.

AIM OF THE STUDY

Traditional Chinese medicine is a complex mixture and it is difficult to distinguish the effective component molecules. The aim of this study is to identify the compounds of QGY with anti-inflammatory effects and investigate the molecular mechanism.

MATERIALS AND METHODS

The high-resolution mass spectrometry and molecular networking were performed for comprehensive chemical profiling of QGY. Network pharmacology was used to generate "herbal-target-pathway" network for target predictions. The anti-inflammation effects of QGY were evaluated in mice model of lipopolysaccharide (LPS) induced acute inflammation. Tail transected zebrafish was also employed to validate macrophage migration reversed effect of QGY. Based on the molecular enrichment analysis, the active substances of QGY with anti-inflammatory effects were further identified in cellular model of macrophage activation. The mechanisms of active substances were investigated by testing their effects on the expression of correlated proteins by Western blot.

RESULTS

In total, 71 compounds are identified as major substances of QGY. According to the results of network pharmacology, QGY shows moderate anti-inflammatory effects and inhibit pulmonary injury. MAPK signaling pathway was predicted as the most related pathway regulated by QGY. Moreover, QGY significantly inhibit LPS-induced pulmonary inflammation in mice, and reversed macrophage migration toward the injury site in zebrafish. We also validate that some major compounds in QGY significantly attenuated the release of IL-1β, IL-6 and TNF-α in LPS-stimulated macrophage. Those active substances including acacetin and arctiin can inhibit the phosphorylation of ERK/JNK and down-regulated the protein expression of BCL-2.

CONCLUSION

Collectively, QGY possessed pronounced anti-inflammation effects. The integration of network pharmacology and experimental results indicated arctiin, iridin, acacetin, liquiritin, and arctigenin are major active substances of QGY with anti-inflammatory effects. The underlying mechanism of QGY involves MAPK signaling pathway and oxidative stress pathway.

Comparison of the in vitro Anti-Inflammatory Effect of Cannabidiol to Dexamethasone

Background

Cannabidiol (CBD) is a non-psychoactive phytocannabinoid constituent of Cannabis sativa with pain-relieving and anti-inflammatory properties. With the emphasis on natural ingredients in cosmetics, CBD has become a new cosmetic ingredient due to its ability to alleviate inflammation. However, in-depth studies that directly compare the effective mechanism and the therapeutic potential of CBD are still needed.

Purpose

The aim of the present study was to investigate the anti-inflammatory effect of CBD in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and compare it to dexamethasone (DEX).

Methods

RAW264.7 macrophages in the logarithmic growth phase were incubated in the presence or absence of LPS. After that, the production of nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were measured. A luciferase reporter assay for nuclear factor kappa B (NF-κB) was performed, and the phosphorylation levels of the mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways were measured.

Results

The present study indicated that CBD had a similar anti-inflammatory effect to DEX by attenuating the LPS-induced production of NO, IL-6, and TNF-α. However, only CBD attenuated JNK phosphorylation levels, and only DEX attenuated IKK phosphorylation levels.

Conclusion

These results suggested that CBD and DEX exhibit similar anti-inflammatory effects on LPS-induced RAW264.7 macrophages mainly through suppressing the MAPK and NF-κB signaling pathways, but with different intracellular mechanisms. These findings suggested that CBD may be considered a natural anti-inflammatory agent for protecting skin from immune disorders.

The exploration of the potential mechanism of oxymatrine-mediated antipruritic effect based on network pharmacology and weighted gene co-expression network analysis

The treatment of chronic itch is considered to be a challenge for its non-histamine dependence and the search for alternative medicine is still striving. The pathology of the chronic itch is closely related to immune system regulation and inflammatory response. Oxymatrine (OMT) is a traditional Chinese medicine ingredient extracted from the roots of Sophora flavescens Aiton with significant antitumor, analgesic, and anti-inflammatory effects. However, the underlying mechanism of OMT on chronic itch is obscure, which limits clinical application. Hence, this study is aimed to clarify the pruritus alleviation mechanism of OMT by combining network pharmacology analysis, weighted gene co-expression analysis (WGCNA), and molecular docking. We screened 125 common targets of OMT regulating inflammation and pruritus with pharmacology technology, the GO enrichment function analysis and KEGG signaling pathway analysis to demonstrate the close relation to the signaling pathways regulating inflammation such as MAPK signaling pathway and PI3K-AKT signaling pathway. We adopted the most relevant templates for pruritus diseases, combined with network pharmacology to preliminarily screen out 3 OMT functions and regulatory targets, exerting a good connection and correlation with the target at the screened disease targets. Further experiments were conducted to explore the potential mechanism of OMT using the LPS-induced RAW264.7 cell inflammation model. The results showed that pretreatment with different concentrations of OMT (25 μM, 50 μM, and 100 μM) for 24 h, inhibited expression of IL-6, iNOS TLR4 and TGFR-1 as well as apoptosis of Raw264.7 cells induced by LPS. Moreover, OMT effectively inhibited LPS-induced MAPK pathway activation and the expression of related sites MAP2K1, MAPK8 MAP2K4, and MAPKAP-K2 in RAW 264.7 cells. The OMT also reduced the phosphorylation of p-38, associated with site in the activation of MAPK signaling pathway. These results could contribute to a better understanding of the mechanisms underlying how OMT alleviates inflammation to treat chronic pruritic diseases and provide a potential drug for the treatment of chronic itch.