TLR4 and CD14 trafficking and its influence on LPS-induced pro-inflammatory signaling

LncRNA 220, a newly discovered long non-conding RNA inhibiting apoptosis and autophagy in Kupffer cells in LPS-induced endotoxemic mice through the XBP1u-PI3K-AKT pathway

Sepsis is recognized as a potentially fatal condition characterized by acute organ dysfunction resulting from an imbalanced immune response to infection. Acute liver injury (ALI) arises as an inflammatory outcome of immune response dysregulation associated with sepsis. Kupffer cells, which are liver-specific macrophages, are known to have a significant impact on ALI, although the precise regulatory mechanism remains unclear. Numerous studies have showcased the regulatory impact of long non-coding RNAs (lncRNAs) on the progression of diverse ailments, yet their precise regulatory mechanisms remain predominantly unexplored. In this study, a novel long non-coding RNA (lncRNA), referred to as lncRNA 220, was discovered using high-throughput sequencing. The expression of lncRNA 220 was found to be significantly elevated in the livers of mice with lipopolysaccharide (LPS)-induced endotoxemia, specifically during the 8-hour time period. Furthermore, in Kupffer cells treated with LPS, lncRNA 220 was observed to inhibit apoptosis and autophagy by activating the PI3K-AKT-mTORC1 pathway. This effect was achieved through the reduction of X-box protein 1 unspliced (Xbp1u) mRNA stability and suppression of its translation in the context of endoplasmic reticulum stress (ERS). Ultimately, this intervention mitigated the progression of LPS-induced ALI. To summarize, our study establishes lncRNA 220 as a newly identified regulator that suppresses apoptosis and autophagy in Kupffer cells subjected to LPS treatment, indicating its potential as a molecular target for ALI in endotoxemic mice.

Generation of Endotoxin-Specific Monoclonal Antibodies by Phage and Yeast Display for Capturing Endotoxin

Endotoxin, a synonym for lipopolysaccharide (LPS), is anchored in the outer membranes of Gram-negative bacteria. Even minute amounts of LPS entering the circulatory system can have a lethal immunoactivating effect. Since LPS is omnipresent in the environment, it poses a great risk of contaminating any surface or solution, including research products and pharmaceuticals. Therefore, monitoring LPS contamination and taking preventive or decontamination measures to ensure human safety is of the utmost importance. Nevertheless, molecules used for endotoxin detection or inhibition often suffer from interferences, low specificity, and low affinity. For this reason, the selection of new binders that are biocompatible, easy to produce, and that can be used for biopharmaceutical applications, such as endotoxin removal, is of high interest. Powerful techniques for selecting LPS-binding molecules in vitro are display technologies. In this study, we established and compared the selection and production of LPS-specific, monoclonal, human single-chain variable fragments (scFvs) through two display methods: yeast and phage display. After selection, scFvs were fused to a human constant fragment crystallizable (Fc). To evaluate the applicability of the constructs, they were conjugated to polystyrene microbeads. Here, we focused on comparing the functionalized beads and their LPS removal capacity to a polyclonal anti-lipid A bead. Summarized, five different scFvs were selected through phage and yeast display, with binding properties comparable to a commercial polyclonal antibody. Two of the conjugated scFv-Fcs outperformed the polyclonal antibody in terms of the removal of LPS in aqueous solution, resulting in 265 times less residual LPS in solution, demonstrating the potential of display methods to generate LPS-specific binding molecules.

Protective Effect of the Naringin-Chitooligosaccharide Complex on Lipopolysaccharide-Induced Systematic Inflammatory Response Syndrome Model in Mice

Naringin is one of the common flavonoids in grapefruit, which has anti-cancer, antioxidant, and anti-inflammatory activities. However, its poor solubility limits its wide application. Therefore, the aim of this study is to investigate the anti-inflammatory effect of naringin combined with chitooligosaccharides with good biocompatibility by constructing a mouse model of systemic inflammatory response syndrome (SIRS). The results showed that the naringin-chitooligosaccharide (NG-COS) complex significantly inhibited lipopolysaccharide (LPS)-induced weight loss, reduced food intake, tissue inflammatory infiltration, and proinflammatory cytokines IL-6, TNF-α, INF-γ, and IL-1β levels. The complex also significantly affected the content of malondialdehyde and the activities of MPO, SOD, and GSH in the liver, spleen, lungs, and serum of mice with systemic inflammation. In addition, NG-COS significantly inhibited the mRNA expression of inflammatory factors in the TLR4/NF-κB signaling pathway. Principal component analysis showed that the complexes could inhibit LPS-induced systemic inflammation in mice, and the effect was significantly better than that of naringin and chitooligosaccharides alone. This study explored the synergistic effects of chitosan and naringin in reducing inflammation and could contribute to the development of novel biomedical interventions.

Diterpenoid Tanshinones Can Inhibit Lung Cancer Progression by Improving the Tumor Microenvironment and Downregulation of NF-κB Expression

Diterpenoid tanshinones (DTs) are a bioactive fraction extracted from Salvia miltiorrhiza. High-performance liquid chromatography analysis revealed the presence of four compounds, namely, tanshinone IIA, tanshinone I, cryptotanshinone, and dihydrotanshinone. In this study, we aimed to propose a possible mechanism for the anti-lung cancer effect of DT. To do so, we utilized a lung cancer nude mice model and a lung cancer cell line (PC9) to investigate the effect of DT on lung cancer. We employed immunohistochemistry, enzyme-linked immunosorbent assay, hematoxylin and eosin staining, and immunofluorescence to analyze the pharmacological role of DT in the inhibition of lung cancer growth. The results showed that DT inhibited tumor growth, induced apoptosis in the nude mice model, and reduced inflammatory cell infiltration. Additionally, DT inhibited PC9 lung cancer cells, growth, proliferation, and migration. The mechanism of action of DT involves not only directly inhibiting cell proliferation and migration but also improving the tumor microenvironment. DT significantly increased the expression of important intestinal gap junction proteins, such as zonula occludens 1 (ZO-1) and occludin I. This upregulation contributes to the reinforcement of the intestinal mucosal barrier, thereby reducing the paracellular transport of lipopolysaccharides (LPS) through the intestine. Consequently, the decreased LPS levels lead to the inhibition of NF-κB expression and downregulation of macrophage polarization, as indicated by the decreased expression of CD68. In conclusion, this study has confirmed that DT has anti-lung cancer properties by improving the inflammatory tumor microenvironment via regulating macrophage polarization and inhibiting LPS-associated immune response. These results provide new insights into the mechanism of DT action against lung cancer.

Enzymatic Synthesis of Noncanonical α-Amino Acids Containing γ-Tertiary Alcohols

Noncanonical amino acids (ncAAs) containing tertiary alcohols are valuable as precursors of natural products and active pharmaceutical ingredients. However, the assembly of such ncAA scaffolds from simple material by C-C bond formation remains a challenging task due to the presence of multiple stereocenters and large steric hindrance. In this study, we present a novel solution to this problem through highly selective enzymatic decarboxylative aldol addition. This method allows for the streamlined assembly of multifunctionalized ncAAs with γ-tertiary alcohols from readily available materials, such as L -aspartatic acid and isatins, vicinal diones and keto esters. The modularity of electrophiles furnished four classes of ncAAs with decent efficiency as well as excellent site and stereocontrol. Computational modeling was employed to gain detailed insight into the catalytic mechanism and to provide a rationale for the observed selectivities. The method offers a single-step approach to producing multifunctionalized ncAAs, which can be directly utilized in peptide synthesis and bioactivity assessment.

The Role of the TLR4-MyD88 Signaling Pathway in the Immune Response of the Selected Scallop Strain "Hongmo No. 1" to Heat Stress

The innate immunity of marine bivalves is challenged upon exposure to heat stress, especially with increases in the frequency and intensity of heat waves. TLR4 serves a classical pattern recognition receptor in recognizing pathogenic microorganisms and activating immune responses. In this study, three genes, HMTLR4, HMMyD88 and HMTRAF6, were characterized as homologs of genes in the TLR4-MyD88 signaling pathway in the selected scallop strain "Hongmo No. 1". According to RT-PCR, acute heat stress (32 °C) inhibited genes in the TLR4-MyD88 signaling pathway, and LPS stimulation-induced activation of TLR4-MyD88 signal transduction was also negatively affected at 32 °C. ELISA showed LPS-induced tumor necrosis factor alpha (TNF-α) or lysozyme (LZM) activity, but this was independent of temperature. RNA interference (RNAi) confirmed that HMTLR4 silencing suppressed the expression of its downstream gene, whether at 24 °C or at 32 °C. The level of TNF-α and the activity of LZM also decreased after injection with dsRNA, indicating a negative effect on the innate immunity of scallops. Additionally, acute heat stress affected the suppression of downstream gene expression when compared with that at 24 °C, which led us to the hypothesis that heat stress directly influences the downstream targets of HMTLR4. These results enrich the knowledge of scallop immunity under heat stress and can be beneficial for the genetic improvement of new scallop strains with higher thermotolerance.

Regulation of the migration of colorectal cancer stem cells via the TLR4/MyD88 signaling pathway by the novel surface marker CD14 following LPS stimulation

Cell surface markers are most widely used in the study of cancer stem cells (CSCs). However, cell surface markers that are safely and stably expressed in CSCs have yet to be identified. Colonic CSCs express leukocyte CD14. CD14 binding to the ligand lipopolysaccharide (LPS) is involved in the inflammatory response via the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signaling pathway. TLR4 and MyD88 have been reported to promote the proliferation, metastasis and tumorigenicity of colon cancer cells, which is consistent with the characteristics of CSCs. In the present study, the proposed experimental method to detect cell proliferation, metastasis and tumorigenesis was used to confirm that, under LPS stimulation, CD14 promoted the proliferation, migration and tumorigenesis of colonic CSCs via the TLR4/MyD88 signaling pathway. Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine assays were used to assess the proliferation and migration of the cells. Colony formation and nude mouse xenograft assays were used to assess the capacity of cells to form tumors. Using western blotting and reverse transcription-quantitative PCR, the mRNA and protein levels of CD14, TLR4 and MyD88 were examined. It was confirmed that CD14 promoted the proliferation, metastasis and tumorigenesis of colon CSCs in response to LPS stimulation via the TLR4/MyD88 signaling pathway, and CD14+ colon cancer cells were successfully isolated and sorted. According to the results of proliferation assay, it was determined that CD14 regulated the LPS-induced proliferation of colon CSCs. CD14, TLR4 and MyD88 protein and mRNA expression was upregulated in colon CSCs in response to LPS stimulation. This indicates a potential novel target for colon CSC-related studies.

Epigenetics in obesity: Mechanisms and advances in therapies based on natural products

Obesity is a major risk factor for morbidity and mortality because it has a close relationship to metabolic illnesses, such as diabetes, cardiovascular diseases, and some types of cancer. With no drugs available, the mainstay of obesity management remains lifestyle changes with exercise and dietary modifications. In light of the tremendous disease burden and unmet therapeutics, fresh perspectives on pathophysiology and drug discovery are needed. The development of epigenetics provides a compelling justification for how environmental, lifestyle, and other risk factors contribute to the pathogenesis of obesity. Furthermore, epigenetic dysregulations can be restored, and it has been reported that certain natural products obtained from plants, such as tea polyphenols, ellagic acid, urolithins, curcumin, genistein, isothiocyanates, and citrus isoflavonoids, were shown to inhibit weight gain. These substances have great antioxidant potential and are of great interest because they can also modify epigenetic mechanisms. Therefore, understanding epigenetic modifications to target the primary cause of obesity and the epigenetic mechanisms of anti-obesity effects with certain phytochemicals can prove rational strategies to prevent the disease and develop novel therapeutic interventions. Thus, the current review aimed to summarize the epigenetic mechanisms and advances in therapies for obesity based on natural products to provide evidence for the development of several potential anti-obesity drug targets.

Recurrent urinary tract infection genetic risk: a systematic review and gene network analysis

INTRODUCTION AND HYPOTHESIS

The development of recurrent urinary tract infections (rUTIs) is not completely understood. This review is aimed at investigating the connection between genetics and rUTIs and summarizing the results of studies that have documented variations in gene expression among individuals with rUTIs compared with healthy individuals.

METHODS

A systematic search was conducted in Cochrane, Ovid, and PubMed, limiting the results to articles published between 1 January 2000, and 5 July 2022. Only studies comparing the difference in gene expression between individuals with rUTI and healthy individuals utilizing molecular techniques to measure gene expression in blood or urine samples were included in this systematic review. Gene network and pathways analyses were performed using Cytoscape software, with input data obtained from our systematic review of differentially expressed genes in rUTIs.

RESULTS

Six studies met our criteria for inclusion. The selected studies used molecular biology methods to quantify gene expression data from blood specimens. The analysis revealed that gene expressions of CXCR1 and TLR4 decreased, whereas CXCR2, TRIF, and SIGIRR increased in patients with rUTI compared with healthy controls. The analysis demonstrated that the most significant pathways were associated with TLR receptor signaling and tolerance, I-kappa B kinase/NF-kappa B signaling, and MyD88-independent TLR signaling.

CONCLUSIONS

This systematic review uncovered gene expression variations in several candidate genes and identified a number of underlying biological pathways associated with rUTIs. These findings could shift the treatment and prevention strategies for rUTIs.

Diverse modulatory effects of bibenzyls from Dendrobium species on human immune cell responses under inflammatory conditions

Dendrobium plants are widely used in traditional Chinese medicine. Their secondary metabolites such as bibenzyls and phenanthrenes show various pharmacological benefits such as immunomodulation and inhibitory effects on cancer cell growth. However, our previous study also showed that some of these promising compounds (i.e., gigantol and cypripedin) also induced the expression of inflammatory cytokines including TNF in human monocytes, and thus raising concerns about the use of these compounds in clinical application. Furthermore, the effects of these compounds on other immune cell populations, apart from monocytes, remain to be investigated. In this study, we evaluated immunomodulatory effects of seven known bibenzyl compounds purified from Dendrobium species in human peripheral blood mononuclear cells (PBMCs) that were stimulated with lipopolysaccharide (LPS). Firstly, using flow cytometry, moscatilin (3) and crepidatin (4) showed the most promising dose-dependent immunomodulatory effects among all seven bibenzyls, determined by significant reduction of TNF expression in LPS-stimulated CD14+ monocytes. Only crepidatin at the concentration of 20 μM showed a significant cytotoxicity, i.e., an increased cell death in late apoptotic state. In addition, deep immune profiling using high-dimensional single-cell mass cytometry (CyTOF) revealed broad effects of Dendrobium compounds on diverse immune cell types. Our findings suggest that to precisely evaluate therapeutic as well as adverse effects of active natural compounds, a multi-parameter immune profiling targeting diverse immune cell population is required.

Insights into the molecular basis and mechanism of heme-triggered TLR4 signalling: The role of heme-binding motifs in TLR4 and MD2

Haemolytic disorders, such as sickle cell disease, are accompanied by the release of high amounts of labile heme into the intravascular compartment resulting in the induction of proinflammatory and prothrombotic complications in affected patients. In addition to the relevance of heme-regulated proteins from the complement and blood coagulation systems, activation of the TLR4 signalling pathway by heme was ascribed a crucial role in the progression of these pathological processes. Heme binding to the TLR4-MD2 complex has been proposed recently, however, essential mechanistic information of the processes at the molecular level, such as heme-binding kinetics, the heme-binding capacity and the respective heme-binding sites (HBMs) is still missing. We report the interaction of TLR4, MD2 and the TLR4-MD2 complex with heme and the consequences thereof by employing biochemical, spectroscopic, bioinformatic and physiologically relevant approaches. Heme binding occurs transiently through interaction with up to four HBMs in TLR4, two HBMs in MD2 and at least four HBMs in their complex. Functional studies highlight that mutations of individual HBMs in TLR4 preserve full receptor activation by heme, suggesting that heme interacts with TLR4 through different binding sites independently of MD2. Furthermore, we confirm and extend the major role of TLR4 for heme-mediated cytokine responses in human immune cells.

Mechanism of action of the bile acid receptor TGR5 in obesity

G protein-coupled receptors (GPCRs) are a large family of membrane protein receptors, and Takeda G protein-coupled receptor 5 (TGR5) is a member of this family. As a membrane receptor, TGR5 is widely distributed in different parts of the human body and plays a vital role in regulating metabolism, including the processes of energy consumption, weight loss and blood glucose homeostasis. Recent studies have shown that TGR5 plays an important role in glucose and lipid metabolism disorders such as fatty liver, obesity and diabetes. With the global obesity situation becoming more and more serious, a comprehensive explanation of the mechanism of TGR5 and filling the gaps in knowledge concerning clinical ligand drugs are urgently needed. In this review, we mainly explain the anti-obesity mechanism of TGR5 to promote the further study of this target, and show the electron microscope structure of TGR5 and review recent studies on TGR5 ligands to illustrate the specific binding between TGR5 receptor binding sites and ligands, which can effectively provide new ideas for ligand research and promote drug research.

Transferrin Is Up-Regulated by Microbes and Acts as a Negative Regulator of Immunity to Induce Intestinal Immunotolerance

Cross-talks (e.g., host-driven iron withdrawal and microbial iron uptake between host gastrointestinal tract and commensal microbes) regulate immunotolerance and intestinal homeostasis. However, underlying mechanisms that regulate the cross-talks remain poorly understood. Here, we show that bacterial products up-regulate iron-transporter transferrin and transferrin acts as an immunosuppressor by interacting with cluster of differentiation 14 (CD14) to inhibit pattern recognition receptor (PRR) signaling and induce host immunotolerance. Decreased intestinal transferrin is found in germ-free mice and human patients with ulcerative colitis, which are characterized by impaired intestinal immunotolerance. Intestinal transferrin and host immunotolerance are returned to normal when germ-free mice get normal microbial commensalism, suggesting an association between microbial commensalism, transferrin, and host immunotolerance. Mouse colitis models show that transferrin shortage impairs host's tolerogenic responses, while its supplementation promotes immunotolerance. Designed peptide blocking transferrin-CD14 interaction inhibits immunosuppressive effects of transferrin. In monkeys with idiopathic chronic diarrhea, transferrin shows comparable or even better therapeutic effects than hydrocortisone. Our findings reveal that by up-regulating host transferrin to silence PRR signaling, commensal bacteria counteract immune activation induced by themselves to shape host immunity and contribute for intestinal tolerance.

Virus-induced brain pathology and the neuroinflammation-inflammation continuum: the neurochemists view

Fascinatingly, an abundance of recent studies has subscribed to the importance of cytotoxic immune mechanisms that appear to increase the risk/trigger for many progressive neurodegenerative disorders, including Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis, and multiple sclerosis. Events associated with the neuroinflammatory cascades, such as ageing, immunologic dysfunction, and eventually disruption of the blood-brain barrier and the "cytokine storm", appear to be orchestrated mainly through the activation of microglial cells and communication with the neurons. The inflammatory processes prompt cellular protein dyshomeostasis. Parkinson's and Alzheimer's disease share a common feature marked by characteristic pathological hallmarks of abnormal neuronal protein accumulation. These Lewy bodies contain misfolded α-synuclein aggregates in PD or in the case of AD, they are Aβ deposits and tau-containing neurofibrillary tangles. Subsequently, these abnormal protein aggregates further elicit neurotoxic processes and events which contribute to the onset of neurodegeneration and to its progression including aggravation of neuroinflammation. However, there is a caveat for exclusively linking neuroinflammation with neurodegeneration, since it's highly unlikely that immune dysregulation is the only factor that contributes to the manifestation of many of these neurodegenerative disorders. It is unquestionably a complex interaction with other factors such as genetics, age, and environment. This endorses the "multiple hit hypothesis". Consequently, if the host has a genetic susceptibility coupled to an age-related weakened immune system, this makes them more susceptible to the virus/bacteria-related infection. This may trigger the onset of chronic cytotoxic neuroinflammatory processes leading to protein dyshomeostasis and accumulation, and finally, these events lead to neuronal destruction. Here, we differentiate "neuroinflammation" and "inflammation" with regard to the involvement of the blood-brain barrier, which seems to be intact in the case of neuroinflammation but defect in the case of inflammation. There is a neuroinflammation-inflammation continuum with regard to virus-induced brain affection. Therefore, we propose a staging of this process, which might be further developed by adding blood- and CSF parameters, their stage-dependent composition and stage-dependent severeness grade. If so, this might be suitable to optimise therapeutic strategies to fight brain neuroinflammation in its beginning and avoid inflammation at all.

Chalcone-derivative L6H21 attenuates the OVA-induced asthma by targeting MD2

Asthma represents a significant global challenge that affects individuals across all age groups and imposes substantial social and economic burden. Due to heterogeneity of the disease, not all patients obtain benefit with current treatments. The objective of this study was to explore the impact of MD2 on the progression of asthma using L6H21, a novel MD2 inhibitor, to identify potential targets and drug candidates for asthma treatment. To establish an asthma-related murine model and evaluate the effects of L6H21, ovalbumin (OVA) was used to sensitize and challenge mice. Pathological changes were examined with various staining techniques, such as H&E staining, glycogen staining, and Masson staining. Inflammatory cell infiltration and excessive cytokine secretion were evaluated by analyzing BALF cell count, RT-PCR, and ELISA. The TLR4/MD2 complex formation, as well as the activation of the MAPK and NF-кB pathways, was examined using western blot and co-IP. Treatment with L6H21 demonstrated alleviation of increased airway resistance, lung tissue injury, inflammatory cell infiltration and excessive cytokine secretion triggered by OVA. In addition, it also ameliorated mucus production and collagen deposition. In the L6H21 treatment group, inhibition of MAPK and NF-кB activation was observed, along with the disruption of TLR4/MD2 complex formation, in contrast to the model group. Thus, L6H21 effectively reduced the formation of the MD2 and TLR4 complex induced by OVA in a dose-dependent manner. This reduction resulted in the attenuation of MAPKs/NF-κB activation, enhanced suppression of inflammatory factor secretion, reduced excessive recruitment of inflammatory cells, and ultimately mitigated airway damage. MD2 emerges as a crucial target for asthma treatment, and L6H21, as an MD2 inhibitor, shows promise as a potential drug candidate for the treatment of asthma.

Dexpanthenol ameliorates lipopolysaccharide-induced cardiovascular toxicity by regulating the IL-6/HIF1α/VEGF pathway

Introduction

Lipopolysaccharide (Lps) is an essential component responsible for the virulence of gram-negative bacteria. Lps can cause damage to many organs, including the heart, kidneys, and lungs. Dexpanthenol (Dex) is an agent that exhibits anti-oxidative and anti-inflammatory effects and stimulates epithelialization. In this study, we aimed to investigate the effects of Dex on Lps-induced cardiovascular toxicity.

Methods

Rats were divided into four groups: control, Lps (5 mg/kg, intraperitoneal), Dex (500 mg/kg, intraperitoneal), and Lps + Dex. The control group received saline intraperitoneally (i.p.) once daily for three days. The Lps group received saline i.p. once daily for three days and a single dose of Lps i.p. was administered on the third day. The Dex group received Dex i.p. once daily for three days and saline on the third day. The Lps + Dex group received Dex i.p. once daily for three days and a single dose of Lps i.p. on the third day. Heart and aortic tissues were taken for biochemical, histopathological, immunohistochemical, and genetic analysis.

Results

Lps injection caused histopathological changes in both heart and aortic tissues and significantly increased total oxidant status and oxidative stress index levels. Interleukin-6, and Tumor necrosis factor-α mRNA expressions were significantly altered in heart and aorta, likely do to the anti-inflammatory and antioxidative effects of Dex. Furthermore, Dex affected Caspase-3 and Hypoxia-inducible factor 1-α staining patterns.

Conclusions

Our results show that Dex treatment has a protective effect on Lps-induced cardiac and endothelial damage in rats by reducing inflammation, oxidative stress, and apoptosis.

Anti-inflammatory effects of Mentha pulegium L. extract on human peripheral blood mononuclear cells are mediated by TLR-4 and NF-κB suppression

There is great interest in evaluating the anti-inflammatory properties of new herbal products. Thus, the effects of Mentha pulegium L. extract on gene and protein expressions of pro-inflammatory mediators and transcription factors were determined. The hydro-ethanolic extract of Mentha pulegium L. was obtained and optimal non-cytotoxic concentrations of the extract were determined by MTT assay. Then, three different concentrations of Mentha pulegium L. (10, 30, and 90 μg/mL) were used to pre-treat the lipopolysaccharide (LPS)-stimulated and non-stimulated peripheral blood mononuclear cells (PBMCs) of 10 healthy individuals. Finally, the tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, Toll-like receptor-4 (TLR-4), nuclear factor-kappa B (NF-κB) p65, activator protein-1 (AP-1), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) gene expressions and TNF-α, IL-1β, IL-6, TLR-4, prostaglandin E2 (PGE2), and COX-2 protein levels were measured. MTT results showed that there is no significant difference in cell viability among 10, 20, 40, and 80 μg/mL concentrations of Mentha pulegium L. extract at 24, 48, and 72 h (P > 0.05). The IC50 values were 236.1, 147.0, and 118.0 μg/mL after 24, 48, and 72 h respectively. TNF-α, IL-1β, IL-6, TLR-4, iNOS, and NF-κB p65 mRNA levels in the pre-treated LPS-stimulated PBMCs were concentration-dependently reduced (P < 0.01 for TNF-α, TLR-4, and NF-κB p65; P < 0.05 for IL-1β, IL-6, and iNOS). Also, the protein levels of pro-inflammatory mediators decreased and these differences were significant for TNF-α, IL-1β, and TLR-4 (P < 0.001, P < 0.01, and P < 0.001, respectively). Mentha pulegium L. extract decreased the expression and biosynthesis of pro-inflammatory mediators. These effects are mainly mediated by TLR-4 and NF-κB suppression. Thus, Mentha pulegium L. could be useful in treating or ameliorating chronic inflammatory diseases.

Potential Antioxidant and Anti-Inflammatory Properties of Polyphenolic Compounds from Cirsium japonicum Extract

Cirsium japonicum is a medicinal plant that has been used due to its beneficial properties. However, extensive information regarding its therapeutic potential is scarce in the scientific literature. The antioxidant and anti-inflammatory potential of polyphenols derived from the Cirsium japonicum extracts (CJE) was systematically analyzed. High-performance liquid chromatography (HPLC) with mass spectrometry (MS) was used to examine the compounds in CJE. A total of six peaks of polyphenol compounds were identified in the extract, and their MS data were also confirmed. These bioactive compounds were subjected to ultrafiltration with LC analysis to assess their potential for targeting cyclooxygenase-2 (COX2) and DPPH. The outcomes showed which primary compounds had the highest affinity for binding both COX2 and DPPH. This suggests that components that showed excellent binding ability to DPPH and COX2 can be considered significant active substances. Additionally, in vitro analysis of CJE was carried out in macrophage cells after inducing inflammation with lipopolysaccharide (LPS). As a result, it downregulated the expression of two critical pro-inflammatory cytokines, COX2 and inducible nitric oxide synthase (iNOS). In addition, we found a solid binding ability through the molecular docking analysis of the selected compounds with inflammatory mediators. In conclusion, we identified polyphenolic compounds in CJE extract and confirmed their potential antioxidant and anti-inflammatory effects. These results may provide primary data for the application of CJE in the food and pharmaceutical industries with further analysis.

Design and synthesis of pterostilbene derivatives bearing triazole moiety that might treat DSS-induced colitis in mice through modulation of NF-κB/MAPK signaling pathways

In this study, a series of novel anti-inflammatory compounds with high activity and low toxicity were designed and synthesized based on the natural product pterostilbene skeleton. According to the strategy of pharmacophore combination, we introduced thiazole moiety into pterostilbene skeleton to design and synthesize a novel series of pterostilbene derivatives (a total of 41 compounds), and lipopolysaccharide (LPS)-treated RAW 264.7 cells were screened for anti-inflammatory activity and cytotoxicity. Among them, compound 8 was found to be the most active (against NO: IC50 = 0.6 μM) compared with pterostilbene and indomethacin. Anti-inflammatory mechanism studies revealed that compound 8 inhibited pro-inflammatory cytokines by blocking the NF-κB/MAPK signaling pathway in LPS-treated RAW 264.7 cells. In vivo experiments showed that compound 8 had a good relieving effect on DSS-induced acute colitis in mice, and also demonstrated a good safety in acute toxicity experiments. In conclusion, compound 8 may be a promising anti-inflammatory lead compound in the treatment of acute colitis.

Knocking out Fkbp51 decreases CCl4-induced liver injury through enhancement of mitochondrial function and Parkin activity

BACKGROUND AND AIMS

Previously, we found that FK506 binding protein 51 (Fkbp51) knockout (KO) mice resist high fat diet-induced fatty liver and alcohol-induced liver injury. The aim of this research is to identify the mechanism of Fkbp51 in liver injury.

METHODS

Carbon tetrachloride (CCl4)-induced liver injury was compared between Fkbp51 KO and wild type (WT) mice. Step-wise and in-depth analyses were applied, including liver histology, biochemistry, RNA-Seq, mitochondrial respiration, electron microscopy, and molecular assessments. The selective FKBP51 inhibitor (SAFit2) was tested as a potential treatment to ameliorate liver injury.

RESULTS

Fkbp51 knockout mice exhibited protection against liver injury, as evidenced by liver histology, reduced fibrosis-associated markers and lower serum liver enzyme levels. RNA-seq identified differentially expressed genes and involved pathways, such as fibrogenesis, inflammation, mitochondria, and oxidative metabolism pathways and predicted the interaction of FKBP51, Parkin, and HSP90. Cellular studies supported co-localization of Parkin and FKBP51 in the mitochondrial network, and Parkin was shown to be expressed higher in the liver of KO mice at baseline and after liver injury relative to WT. Further functional analysis identified that KO mice exhibited increased ATP production and enhanced mitochondrial respiration. KO mice have increased mitochondrial size, increased autophagy/mitophagy and mitochondrial-derived vesicles (MDV), and reduced reactive oxygen species (ROS) production, which supports enhancement of mitochondrial quality control (MQC). Application of SAFit2, an FKBP51 inhibitor, reduced the effects of CCl4-induced liver injury and was associated with increased Parkin, pAKT, and ATP production.

CONCLUSIONS

Downregulation of FKBP51 represents a promising therapeutic target for liver disease treatment.

Isoquercitrin alleviates lipopolysaccharide-induced intestinal mucosal barrier damage in mice by regulating TLR4/MyD88/NF-κB signaling pathway and intestinal flora

Intestinal mucosal barrier damage is closely associated with the development of several intestinal inflammatory diseases. Isoquercitrin (IQ) is a natural flavonoid compound derived from plants, which exhibits high antioxidant and anti-inflammatory activity with minimal side effects in humans. Therefore, it shows great potential for preventing and treating intestinal mucosal barrier damage. This study aims to investigate the ameliorative effect and mechanism of IQ on lipopolysaccharide (LPS)-induced intestinal mucosal barrier damage in mice. The mice were treated with IQ for 7 days and then injected with LPS to induce intestinal mucosal barrier damage. The results revealed that IQ treatment alleviated LPS-induced intestinal mucosal barrier damage in mice, which can be evidenced by the improvements in intestinal morphology and the promotion of expression in intestinal tight junctions (ZO-1, Claudin-1, and Occludin), as well as MUC2 mucin. IQ also attenuated intestinal inflammatory responses by inhibiting the TLR4/MyD88/NF-κB signaling pathway and reducing the expression and plasma levels of IL-6, IL-1β, and TNF-α. Furthermore, IQ significantly increased the relative abundance of beneficial bacteria, including Dubosiella, Akkermansia muciniphila and Faecalibaculum rodentium, while suppressing the growth of harmful bacteria such as Mucispirillum schaedleri in the intestinal flora of mice. Consequently, IQ can alleviate the LPS-induced intestinal mucosal barrier damage in mice by inhibiting the TLR4/MyD88/NF-κB signaling pathway and modulating the intestinal flora.

Flavonoid diversity and roles in the lipopolysaccharide-mediated inflammatory response of monocytes and macrophages

Targeting lipopolysaccharide (LPS)/toll-like receptor 4 signaling in mononuclear phagocytes has been explored for the treatment of inflammation and inflammation-related disorders. However, only a few key targets have been translated into clinical applications. Flavonoids, a class of ubiquitous plant secondary metabolites, possess a privileged scaffold which serves as a valuable template for designing pharmacologically active compounds directed against diseases with inflammatory components. This perspective provides a general overview of the diversity of flavonoids and their multifaceted mechanisms that interfere with LPS-induced signaling in monocytes and macrophages. Focus is placed on flavonoids targeting MD-2, IκB kinases, c-Jun N-terminal kinases, extracellular signal-regulated kinase, p38 MAPK and PI3K/Akt or modulating LPS-related gene expression.

Clavulanic Acid and its Potential Therapeutic Effects on the Central Nervous System

Clavulanic acid (CLAV) is a non-antibiotic β-lactam that has been used since the late 1970s as a β-lactamase inhibitor in combination with amoxicillin, another ß-lactam with antibiotic activity. Its long-observed adverse reaction profile allows it to say that CLAV is a well-tolerated drug with mainly mild adverse reactions. Interestingly, in 2005, it was discovered that β-lactams enhance the astrocytic expression of GLT-1, a glutamate transporter essential for maintaining synaptic glutamate homeostasis involved in several pathologies of the central nervous system (CNS). This finding, along with a favorable pharmacokinetic profile, prompted the appearance of several studies that intended to evaluate the effect of CLAV in preclinical disease models. Studies have revealed that CLAV can increase GLT-1 expression in the nucleus accumbens (NAcc), medial prefrontal cortex (PFC), and spinal cord of rodents, to affect glutamate and dopaminergic neurotransmission, and exert an anti-inflammatory effect by modulating the levels of the cytokines TNF-α and interleukin 10 (IL-10). CLAV has been tested with positive results in preclinical models of epilepsy, addiction, stroke, neuropathic and inflammatory pain, dementia, Parkinson's disease, and sexual and anxiety behavior. These properties make CLAV a potential therapeutic drug if repurposed. Therefore, this review aims to gather information on CLAV's effect on preclinical neurological disease models and to give some perspectives on its potential therapeutic use in some diseases of the CNS.

Prevotella copri promotes vascular calcification via lipopolysaccharide through activation of NF-κB signaling pathway

Emerging evidence indicates that alteration of gut microbiota plays an important role in chronic kidney disease (CKD)-related vascular calcification (VC). We aimed to investigate the specific gut microbiota and the underlying mechanism involved in CKD-VC. We identified an increased abundance of Prevotella copri (P. copri) in the feces of CKD rats (induced by using 5/6 nephrectomy followed by a high calcium and phosphate diet) with aortic calcification via amplicon sequencing of 16S rRNA genes. In patients with CKD, we further confirmed a positive correlation between abundance of P. copri and aortic calcification scores. Moreover, oral administration of live P. copri aggravated CKD-related VC and osteogenic differentiation of vascular smooth muscle cells in vivo, accompanied by intestinal destruction, enhanced expression of Toll-like receptor-4 (TLR4), and elevated lipopolysaccharide (LPS) levels. In vitro and ex vivo experiments consistently demonstrated that P. copri-derived LPS (Pc-LPS) accelerated high phosphate-induced VC and VSMC osteogenic differentiation. Mechanistically, Pc-LPS bound to TLR4, then activated the nuclear factor κB (NF-κB) and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome signals during VC. Inhibition of NF-κB reduced NLRP3 inflammasome and attenuated Pc-LPS-induced VSMC calcification. Our study clarifies a novel role of P. copri in CKD-related VC, by the mechanisms involving increased inflammation-regulating metabolites including Pc-LPS, and activation of the NF-κB/NLRP3 signaling pathway. These findings highlight P. copri and its-derived LPS as potential therapeutic targets for VC in CKD.

Protective Role of MAVS Signaling for Murine Lipopolysaccharide-Induced Acute Kidney Injury

Despite treatment advances, acute kidney injury (AKI)-related mortality rates are still high in hospitalized adults, often due to sepsis. Sepsis and AKI could synergistically worsen the outcomes of critically ill patients. TLR4 signaling and mitochondrial antiviral signaling protein (MAVS) signaling are innate immune responses essential in kidney diseases, but their involvement in sepsis-associated AKI (SA-AKI) remains unclear. We studied the role of MAVS in kidney injury related to the TLR4 signaling pathway using a murine LPS-induced AKI model in wild-type and MAVS-knockout mice. We confirmed the importance of M1 macrophage in SA-AKI through in vivo assessment of inflammatory responses. The TLR4 signaling pathway was upregulated in activated bone marrow-derived macrophages, in which MAVS helped maintain the LPS-suppressed TLR4 mRNA level. MAVS regulated redox homeostasis via NADPH oxidase Nox2 and mitochondrial reverse electron transport in macrophages to alleviate the TLR4 signaling response to LPS. Hypoxia-inducible factor 1α (HIF-1α) and AP-1 were key regulators of TLR4 transcription and connected MAVS-dependent reactive oxygen species signaling with the TLR4 pathway. Inhibition of succinate dehydrogenase could partly reduce inflammation in LPS-treated bone marrow-derived macrophages without MAVS. These findings highlight the renoprotective role of MAVS in LPS-induced AKI by regulating reactive oxygen species generation-related genes and maintaining redox balance. Controlling redox homeostasis through MAVS signaling may be a promising therapy for SA-AKI.

Glomerular-tubular crosstalk via cold shock Y-box binding protein-1 in the kidney

Glomerular-tubular crosstalk within the kidney has been proposed, but the paracrine signals enabling this remain largely unknown. The cold-shock protein Y-box binding protein 1 (YBX1) is known to regulate inflammation and kidney diseases but its role in podocytes remains undetermined. Therefore, we analyzed mice with podocyte specific Ybx1 deletion (Ybx1ΔPod). Albuminuria was increased in unchallenged Ybx1ΔPod mice, which surprisingly was associated with reduced glomerular, but enhanced tubular damage. Tubular toll-like receptor 4 (TLR4) expression, node-like receptor protein 3 (NLRP3) inflammasome activation and kidney inflammatory cell infiltrates were all increased in Ybx1ΔPod mice. In vitro, extracellular YBX1 inhibited NLRP3 inflammasome activation in tubular cells. Co-immunoprecipitation, immunohistochemical analyses, microscale cell-free thermophoresis assays, and blunting of the YBX1-mediated TLR4-inhibition by a unique YBX1-derived decapeptide suggests a direct interaction of YBX1 and TLR4. Since YBX1 can be secreted upon post-translational acetylation, we hypothesized that YBX1 secreted from podocytes can inhibit TLR4 signaling in tubular cells. Indeed, mice expressing a non-secreted YBX1 variant specifically in podocytes (Ybx1PodK2A mice) phenocopied Ybx1ΔPod mice, demonstrating a tubular-protective effect of YBX1 secreted from podocytes. Lipopolysaccharide-induced tubular injury was aggravated in Ybx1ΔPod and Ybx1PodK2A mice, indicating a pathophysiological relevance of this glomerular-tubular crosstalk. Thus, our data show that YBX1 is physiologically secreted from podocytes, thereby negatively modulating sterile inflammation in the tubular compartment, apparently by binding to and inhibiting tubular TLR4 signaling. Hence, we have uncovered an YBX1-dependent molecular mechanism of glomerular-tubular crosstalk.

The Therapeutic Potential of (+)-Afzelechin for Alleviating Sepsis-Associated Pulmonary Injury

Sepsis-induced acute lung injury (ALI) poses a common and formidable challenge in clinical practice, currently lacking efficacious therapeutic approaches. This study delves into the evaluation of (+)-afzelechin (AZC), a natural compound derived from Bergenia ligulata with a diverse array of properties, encompassing antioxidant, anticancer, antimicrobial, and cardiovascular effects to ascertain its effectiveness and underlying mechanisms in mitigating sepsis-induced ALI through animal experimentation. An ALI mouse model induced by sepsis was established through lipopolysaccharide (LPS) administration, and various analytical techniques, including quantitative real-time polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay were employed to gauge inflammatory cytokine levels, lung injury, and associated signaling pathways. The animal experiments revealed that AZC offered safeguards against lung injury induced by LPS while reducing inflammatory cytokine levels in both blood serum and lung tissue. Western blotting experiments revealed AZC's downregulation of the toll-like receptor (TLR)4/NF-κB pathway and the upregulation of PI3K/Akt, coupled with inhibition of the Hippo and Rho signaling pathways. These findings underscore AZC's efficacy in ameliorating sepsis-induced ALI by modulating cytokine storms and curtailing inflammation via the regulation of TLR4/NF-κB, PI3K/Akt, Hippo, and Rho signaling pathways. This work serves as a foundation for additional exploration into AZC's mechanisms and its potential as a therapy for sepsis-induced ALI. Animals in accordance with Kyungpook National University (IRB No. KNU 2022-174).

Variant rs4986790 of toll-like receptor 4 affects the signaling and induces cell dysfunction in patients with severe COVID-19

OBJECTIVES

We investigated the expression of toll-like receptor (TLR)-4 on the cell surface of innate and adaptive cells from patients with COVID-19 carrying the rs4986790 GG genotype in the TLR4 gene and the functional profile of these cells.

METHODS

We included 1169 hospitalized patients with COVID-19. The rs4986790 in TLR4 was identified by real-time polymerase chain reaction. Peripheral blood mononuclear cells were isolated and cultured to evaluate TLR-4 expression on immune cells. Supernatants recovered culture assays were stored, and we measured cytokines and cytotoxic molecules.

RESULTS

We showed that the rs4986790 (GG) was significantly associated (P = 0.0310) with severe COVID-19. Cells of patients with COVID-19 carrying the GG genotype have increased the frequency of monocytes and activated naïve and non-switched B cells positive to TLR-4 when cells are stimulated with lipopolysaccharide and with spike protein of SARS-CoV-2. Also, cells from patients with GG COVID-19 cannot produce pro-inflammatory cytokines after lipopolysaccharide stimulus, but they are high producers of cytotoxic molecules at baseline.

CONCLUSIONS

The rs4986790 GG genotype of the TLR4 is associated with the risk of COVID-19 and acute respiratory distress syndrome. Peripheral blood mononuclear cells of patients carrying the rs4986790 (TLR4) GG genotype had a limited delivery of pro-inflammatory cytokines compared to the AA and AG genotypes in which TLR-4 stimulation induces IL-10, IL-6, tumor necrosis factor-α, and Fas ligand production.

Bacopaside I alleviates depressive-like behaviors by modulating the gut microbiome and host metabolism in CUMS-induced mice

Bacopaside I (BSI) is a natural compound that is difficult to absorb orally but has been shown to have antidepressant effects. The microbiota-gut-brain axis is involved in the development of depression through the peripheral nervous system, endocrine system, and immune system and may be a key factor in the effect of BSI. Therefore, this study aimed to investigate the potential mechanism of BSI in the treatment of depression via the microbiota-gut-brain axis and to validate it in a fecal microbiota transplantation model. The antidepressant effect of BSI was established in CUMS-induced mice using behavioral tests and measurement of changes in hypothalamicpituitaryadrenal (HPA) axis-related hormones. The improvement of stress-induced gut-brain axis damage by BSI was observed by histopathological sections and enzyme-linked immunosorbent assay (ELISA). 16 S rDNA sequencing analysis indicated that BSI could modulate the abundance of gut microbiota and increase the abundance of probiotic bacteria. We also observed an increase in short-chain fatty acids, particularly acetic acid. In addition, BSI could modulate the disruption of lipid metabolism induced by CUMS. Fecal microbiota transplantation further confirmed that disruption of the microbiota-gut-brain axis is closely associated with the development of depression, and that the microbiota regulated by BSI exerts a partial antidepressant effect. In conclusion, BSI exerts antidepressant effects by remodeling gut microbiota, specifically through the Lactobacillus and Streptococcus-acetic acid-neurotrophin signaling pathways. Furthermore, BSI can repair damage to the gut-brain axis, regulate HPA axis dysfunction, and maintain immune homeostasis.

Do Bacterial Outer Membrane Vesicles Contribute to Chronic Inflammation in Parkinson's Disease?

Parkinson's disease (PD) is an increasingly common neurodegenerative disease. It has been suggested that the etiology of idiopathic PD is complex and multifactorial involving environmental contributions, such as viral or bacterial infections and microbial dysbiosis, in genetically predisposed individuals. With advances in our understanding of the gut-brain axis, there is increasing evidence that the intestinal microbiota and the mammalian immune system functionally interact. Recent findings suggest that a shift in the gut microbiome to a pro-inflammatory phenotype may play a role in PD onset and progression. While there are links between gut bacteria, inflammation, and PD, the bacterial products involved and how they traverse the gut lumen and distribute systemically to trigger inflammation are ill-defined. Mechanisms emerging in other research fields point to a role for small, inherently stable vesicles released by Gram-negative bacteria, called outer membrane vesicles in disease pathogenesis. These vesicles facilitate communication between bacteria and the host and can shuttle bacterial toxins and virulence factors around the body to elicit an immune response in local and distant organs. In this perspective article, we hypothesize a role for bacterial outer membrane vesicles in PD pathogenesis. We present evidence suggesting that these outer membrane vesicles specifically from Gram-negative bacteria could potentially contribute to PD by traversing the gut lumen to trigger local, systemic, and neuroinflammation. This perspective aims to facilitate a discussion on outer membrane vesicles in PD and encourage research in the area, with the goal of developing strategies for the prevention and treatment of the disease.

The Role of Gasdermin-D-Mediated Pryoptosis in Organ Injury and Its Therapeutic Implications

Gasdermin-D (GSDMD) belongs to the Gasdermin family (GSDM), which are pore-forming effector proteins that facilitate inflammatory cell death, also known as pyroptosis. This type of programmed cell death is dependent on inflammatory caspase activation, which cleaves gasdermin-D (GSDMD) to form membrane pores and initiates the release of pro-inflammatory cytokines. Pyroptosis plays an important role in achieving immune regulation and homeostasis within various organ systems. The role of GSDMD in pyroptosis has been extensively studied in recent years. In this review, we summarize the role of GSDMD in cellular and organ injury mediated by pyroptosis. We will also provide an outlook on GSDMD therapeutic targets in various organ systems.

RNF115/BCA2 deficiency alleviated acute liver injury in mice by promoting autophagy and inhibiting inflammatory response

The E3 ubiquitin ligase RING finger protein 115 (RNF115), also known as breast cancer-associated gene 2 (BCA2), has been linked with the growth of some cancers and immune regulation, which is negatively correlated with prognosis. Here, it is demonstrated that the RNF115 deletion can protect mice from acute liver injury (ALI) induced by the treatment of lipopolysaccharide (LPS)/D-galactosamine (D-GalN), as evidenced by decreased levels of alanine aminotransaminase, aspartate transaminase, inflammatory cytokines (e.g., tumor necrosis factor α and interleukin-6), chemokines (e.g., MCP1/CCL2) and inflammatory cell (e.g., monocytes and neutrophils) infiltration. Moreover, it was found that the autophagy activity in Rnf115-/- livers was increased, which resulted in the removal of damaged mitochondria and hepatocyte apoptosis. However, the administration of adeno-associated virus Rnf115 or autophagy inhibitor 3-MA impaired autophagy and aggravated liver injury in Rnf115-/- mice with ALI. Further experiments proved that RNF115 interacts with LC3B, downregulates LC3B protein levels and cell autophagy. Additionally, Rnf115 deletion inhibited M1 type macrophage activation via NF-κB and Jnk signaling pathways. Elimination of macrophages narrowed the difference in liver damage between Rnf115+/+ and Rnf115-/- mice, indicating that macrophages were linked in the ALI induced by LPS/D-GalN. Collectively, for the first time, we have proved that Rnf115 inactivation ameliorated LPS/D-GalN-induced ALI in mice by promoting autophagy and attenuating inflammatory responses. This study provides new evidence for the involvement of autophagy mechanisms in the protection against acute liver injury.

Quercetin inhibits the activity and function of dendritic cells through the TLR4/IRAK4/NF-κB signalling pathway

Introduction

To investigate the inhibitory effect of quercetin (QUE) on dendritic cells (DCs) through the toll-like receptor 4/interleukin-1 receptor-associated kinase 4/nuclear factor kappa-B (TLR4/IRAK4/NF-κB) signalling pathway.

Material and methods

CCK-8 and apoptosis assays were performed to determine the optimal concentration and action time of QUE to inhibit DCs. Protein extracts from treated DCs were used for Western blotting experiments to determine the relative expression levels of TLR4, IRAK4, and NF-κB p65 proteins. Changes in the ratio of CD86 and CD11c positive cells on the DCs surface were detected using flow cytometry. The molecular docking technique was used to analyse the binding site and free energy of QUE and IRAK4.

Results

CCK-8 and apoptosis assays suggested that QUE inhibited the activity and function of DCs in a time-dose-dependent manner. The results of Western blotting suggested that the relative expression levels of TLR4, IRAK4, and NF-κB p65 proteins were increased in the lipopolysaccharide (LPS) group compared with the normal control group, and the relative expression of the above proteins was decreased after treatment with QUE and IRAK4-IN-4. The results of flow cytometry suggested that LPS increased the expression of CD86 and CD11c on the surface of DCs, and QUE and IRAK4-IN-4 decreased the expression of CD86 and CD11c induced by LPS. Molecular docking results showed that the binding sites of QUE and IRAK4 were stable, with the minimum binding energies comparable to that of IRAK4-IN-4.

Conclusions

Quercetin may inhibit the activity and function of DCs through the TLR4/IRAK4/NF-κB signalling pathway, and IRAK4 may be its target.

From the Sun to the Cell: Examining Obesity through the Lens of Vitamin D and Inflammation

Obesity affects more than one billion people worldwide and often leads to cardiometabolic chronic comorbidities. It induces senescence-related alterations in adipose tissue, and senescence is closely linked to obesity. Fully elucidating the pathways through which vitamin D exerts anti-inflammatory effects may improve our understanding of local adipose tissue inflammation and the pathogenesis of metabolic disorders. In this narrative review, we compiled and analyzed the literature from diverse academic sources, focusing on recent developments to provide a comprehensive overview of the effect of vitamin D on inflammation associated with obesity and senescence. The article reveals that the activation of the NF-κB (nuclear factor kappa B subunit 1) and NLRP3 inflammasome (nucleotide-binding domain, leucine-rich-containing, pyrin domain-containing-3) pathways through the toll-like receptors, which increases oxidative stress and cytokine release, is a common mechanism underlying inflammation associated with obesity and senescence, and it discusses the potential beneficial effect of vitamin D in alleviating the development of subclinical inflammation. Investigating the main target cells and pathways of vitamin D action in adipose tissue could help uncover complex mechanisms of obesity and cellular senescence. This review summarizes significant findings related to opportunities for improving metabolic health.

TRAM deletion attenuates monocyte exhaustion and alleviates sepsis severity

Monocyte exhaustion characterized by immune-suppressive features can develop during sepsis and contribute to adverse patient outcomes. However, molecular mechanisms responsible for the establishment of immune-suppressive monocytes with reduced expression of immune-enhancing mediators such as CD86 during sepsis are not well understood. In this study, we identified that the TLR4 intracellular adaptor TRAM plays a key role in mediating the sustained reduction of CD86 expression on exhausted monocytes and generating an immune-suppressive monocyte state. TRAM contributes to the prolonged suppression of CD86 through inducing TAX1BP1 as well as SARM1, collectively inhibiting Akt and NFκB. TRAM deficient mice are protected from cecal slurry-induced experimental sepsis and retain immune-competent monocytes with CD86 expression. Our data reveal a key molecular circuitry responsible for monocyte exhaustion and provide a viable target for rejuvenating functional monocytes and treating sepsis.

Involvement of endoplasmic reticulum and histone proteins in immunomodulation by TLR4-interacting SPA4 peptide against Escherichia coli

Pulmonary host defense is critical for the control of lung infection and inflammation. An increased expression and activity of Toll-like receptor 4 (TLR4) induce phagocytic uptake/clearance and inflammation against Gram-negative bacteria. In this study, we addressed the mechanistic aspect of the immunomodulatory activity of the TLR4-interacting SPA4 peptide (amino acid sequence GDFRYSDGTPVNYTNWYRGE) against Escherichia coli. Binding of the SPA4 peptide to bacteria and direct anti-bacterial effects were investigated using flow cytometric, microscopic, and bacteriological methods. The bacterial uptake and inflammatory cytokine response were studied in dendritic cells expressing endogenous basal level of TLR4 or overexpressing TLR4. The subcellular distribution and co-localization of TLR4 and bacteria were investigated by immunocytochemistry. Furthermore, we studied the cellular expression and co-localization of endoplasmic reticulum (ER) molecules (calnexin and ER membrane protein complex subunit 1; EMC1) with lysosomal-associated membrane protein 1 (LAMP1) in cells infected with E. coli and treated with the SPA4 peptide. Simultaneously, the expression of histone H2A protein was quantitated by immunoblotting. Our results demonstrate no binding or direct killing of the bacteria by SPA4 peptide. Instead, it induces the uptake and localization of E. coli in the phagolysosomes for lysis and simultaneously suppresses the secreted levels of TNF-α. Overexpression of TLR4 further augments the pro-phagocytic and anti-inflammatory activity of SPA4 peptide. A time-dependent change in subcellular distribution of TLR4 and an increased co-localization of TLR4 with E. coli in SPA4 peptide-treated cells suggest an enhanced recognition and internalization of bacteria in conjugation with TLR4. Furthermore, an increased co-localization of calnexin and EMC1 with LAMP1 indicates the involvement of ER in pro-phagocytic activity of SPA4 peptide. Simultaneous reduction in secreted amounts of TNF-α coincides with suppressed histone H2A protein expression in the SPA4 peptide-treated cells. These results provide initial insights into the plausible role of ER and histones in the TLR4-immunomodulatory activity of SPA4 peptide against Gram-negative bacteria.

Comprehensive proteomic analysis reveals omega-3 fatty acids to counteract endotoxin-stimulated metabolic dysregulation in porcine enterocytes

Omega-3 polyunsaturated fatty acids (n-3 PUFA), such as the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are reported to beneficially affect the intestinal immunity. The biological pathways modulated by n-3 PUFA during an infection, at the level of intestinal epithelial barrier remain elusive. To address this gap, we investigated the proteomic changes induced by n-3 PUFA in porcine enterocyte cell line (IPEC-J2), in the presence and absence of lipopolysaccharide (LPS) stress conditions using shotgun proteomics analysis integrated with RNA-sequencing technology. A total of 33, 85, and 88 differentially abundant proteins (DAPs) were identified in cells exposed to n-3 PUFA (DHA:EPA), LPS, and n-3 PUFA treatment followed by LPS stimulation, respectively. Functional annotation and pathway analysis of DAPs revealed the modulation of central carbon metabolism, including the glycolysis/gluconeogenesis, pentose phosphate pathway, and oxidative phosphorylation processes. Specifically, LPS caused metabolic dysregulation in enterocytes, which was abated upon prior treatment with n-3 PUFA. Besides, n-3 PUFA supplementation facilitated enterocyte development and lipid homeostasis. Altogether, this work for the first time comprehensively described the biological pathways regulated by n-3 PUFA in enterocytes, particularly during endotoxin-stimulated metabolic dysregulation. Additionally, this study may provide nutritional biomarkers in monitoring the intestinal health of human and animals on n-3 PUFA-based diets.

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

Anti-TLR4 biological response to titanium nitride-coated dental implants: anti-inflammatory response and extracellular matrix synthesis

Osteointegration is a key process during dental implant placement and is related to titanium surface topography. Implant coating and surface modification methods ameliorate the bone production and the osteogenic process. The current work aimed at evaluating the biological outcomes of two different surfaces of dental implants, machined and titanium nitride (TiN) coated, at an inflammation level using an in vitro model of human periodontal ligament stem cells. The TLR4/MyD88/NF-κB p65/NLRP3 pathway induced by the Porphyromonas gingivalis lipopolysaccharide was studied by means of gene- and protein-level expression. Moreover, the expression of vimentin, vinculin, and fibronectin was evaluated to investigate their effects on the cell adhesion and extracellular matrix deposition. The results of the present study suggest that TiN-coated titanium disks may modulate inflammation by the suppression of the TLR4/MyD88/NF-κB p65/NLRP3 pathway and accelerate extracellular matrix apposition.

Investigation of Correlation between Resistance to Diazepam and Expression of Inflammatory Markers in The Peripheral Blood of Patients with Status Epilepticus

OBJECTIVE

This study investigated several inflammatory markers' gene and protein expression in status epilepticus (SE) and their correlation with diazepam resistance.

MATERIALS AND METHODS

Peripheral blood samples were collected from 18 adult patients with SE in Cipto Mangunkusumo Central Hospital, consisting of 12 diazepam-responsive and six diazepam-resistant samples, within 72 hours of the onset of the seizure. We collected baseline demographic and clinical data from each subject. Peripheral blood mononuclear cells (PBMCs) were isolated, cultured, stimulated with lipopolysaccharide (LPS) 1 mg/ml, and harvested for RNA isolation. The RNA was used to determine the expression of Human Mobility Group Box 1 (HMGB1), Interleukin- 6 (IL-6), IL-10, Toll-like Receptor 4 (TLR4), and Glial fibrillary acidic protein (GFAP). In addition, we performed serum protein assay of HMGB1, IL-6, IL-10, TLR4, and GFAP to compare with gene expression.

RESULTS

We found a significant difference between the responsive and resistant groups for serum HMGB1 and IL-6 concentration. The mRNA expression of HMGB1 and IL-6 was significantly higher in LPS-stimulated samples in the responsive but not in the resistant groups. The ratio of IL-6 to IL-10 showed a significant difference between LPS and control in the responsive group. Diazepam response was significantly correlated with seizure duration and serum protein concentration of HMGB1.

CONCLUSION

HMGB1 was highly expressed in the resistant group and strongly correlated with diazepam response, and there was a significant increase in HMGB1 mRNA expression in response to LPS stimulation. These findings suggest that targeting HMGB1 may be a promising therapeutic strategy and that HMGB1 levels could be a valuable biomarker for predicting diazepam resistance in SE.

Recent advances in anti-inflammatory active components and action mechanisms of natural medicines

Inflammation is a series of reactions caused by the body's resistance to external biological stimuli. Inflammation affects the occurrence and development of many diseases. Anti-inflammatory drugs have been used widely to treat inflammatory diseases, but long-term use can cause toxic side-effects and affect human functions. As immunomodulators with long-term conditioning effects and no drug residues, natural products are being investigated increasingly for the treatment of inflammatory diseases. In this review, we focus on the inflammatory process and cellular mechanisms in the development of diseases such as inflammatory bowel disease, atherosclerosis, and coronavirus disease-2019. Also, we focus on three signaling pathways (Nuclear factor-kappa B, p38 mitogen-activated protein kinase, Janus kinase/signal transducer and activator of transcription-3) to explain the anti-inflammatory effect of natural products. In addition, we also classified common natural products based on secondary metabolites and explained the association between current bidirectional prediction progress of natural product targets and inflammatory diseases.

Sodium alginate combined with oxymatrine ameliorates CCl4-induced chemical hepatic fibrosis in mice

Hepatic fibrosis (HF) is a challenging clinical problem. Both sodium alginate (SA) and oxymatrine (OM) can be used to treat HF; however, the influence of viscosity on the therapeutic efficacy of sodium alginate is currently unknown. This study used a CCl4-induced HF mouse model to screen the specifications and doses of SA and investigate its therapeutic effects on HF in combination with OM. Sodium alginate of different viscosities ameliorated HF in mice, with 232 mPa·s SA delivered at a dose of 100 mg/kg showing remarkable therapeutic effect, characterized by reduced aspartate transaminase/alanine transaminase levels, reduced expression of α-SMA, collagen I, and other related genes, and increased abundance of beneficial intestinal probiotics such as Lactococcus and Blautia. The combination treatment further improved other related indices and increased the abundance of Phascolarctobacterium and Oscillospiraceae. These results suggest that the oral administration of SA may improve HF via the "gut-liver axis" based on the gut microbiota and has potential clinical applications.

Deciphering the interplay between LPS/TLR4 pathways, neurotransmitter, and deltamethrin-induced depressive-like behavior: Perspectives from the gut-brain axis

The improper use of deltamethrin (DM) can result in its accumulation in soil, water, food, and even the human body, which is associated with an elevated risk of neurotoxicity and behavioral abnormalities; however, the underlying mechanisms remain insufficiently investigated. Emerging evidence underscores the significance of the gut-brain axis in central nervous system (CNS) dysfunctions. Accordingly, this study investigates the role of the gut-brain axis in DM-induced behavioral anomalies in mice. The results showed that DM exposure induced depressive-like behavior, and the hippocampus, the region that is responsible for the modulation of emotional behavior, showed structural integrity disrupted (neuronal nuclear shrinkage and decreased tight junction protein expression). In addition, DM exposure led to compromised gut barrier integrity (disruptions on crypt surfaces and decreased tight junction protein expression), which might contribute to the gut bacterial-derived lipopolysaccharide (LPS) leakage into the bloodstream and reaching the brain, triggering LPS/toll-like receptor (TLR) 4 -mediated increases in brain pro-inflammatory cytokines. Subsequently, we observed a disturbance in neurotransmitter metabolic pathways following DM exposure, which inhibited the production of 5-hydroxytryptamine (5-HT). Additionally, DM exposure resulted in gut microbiota dysbiosis. Characteristic bacteria, such as Alistipes, Bifidobacterium, Gram-negative bacterium cTPY-13, and Odoribacter exhibited significant correlations with behavior, tight junction proteins, inflammatory response, and neurotransmitters. Further fecal microbiota transplantation (FMT) experiments suggested that DM-induced gut microbiota dysbiosis might contribute to depressive-like behavior. These results provide a new perspective on the toxicity mechanism of DM, indicating that its neurotoxicity may be partially regulated by the microbiota-gut-brain axis.

Direct immunoactivation by chemotherapeutic drugs in cancer treatment

The immune system plays a crucial role in recognizing and eliminating pathogenic substances and malignant cells in the body. For cancer treatment, immunotherapy is becoming the standard treatment for many types of cancer and is often combined with chemotherapy. Although chemotherapeutic agents are often reported to have adverse effects, including immunosuppression, they can also play a positive role in immunotherapy by directly stimulating the immune system. This has been demonstrated in preclinical and clinical studies in the past decades. Chemotherapeutics can activate immune cells through different immune receptors and signaling pathways depending on their chemical structure and formulation. In this review, we summarize and discuss the direct immunoactivation effects of chemotherapeutics and possible mechanisms behind these effects. Finally, we prospect chemo-immunotherapeutic combinations for the more effective and safer treatment of cancer.

Regulation of toll-like receptor (TLR) signaling pathways in atherosclerosis: from mechanisms to targeted therapeutics

Atherosclerosis, one of the life-threatening cardiovascular diseases (CVDs), has been demonstrated to be a chronic inflammatory disease, and inflammatory and immune processes are involved in the origin and development of the disease. Toll-like receptors (TLRs), a class of pattern recognition receptors that trigger innate immune responses by identifying pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs), regulate numerous acute and chronic inflammatory diseases. Recent studies reveal that TLRs have a vital role in the occurrence and development of atherosclerosis, including the initiation of endothelial dysfunction, interaction of various immune cells, and activation of a number of other inflammatory pathways. We herein summarize some other inflammatory signaling pathways, protein molecules, and cellular responses associated with TLRs, such as NLRP3, Nrf2, PCSK9, autophagy, pyroptosis and necroptosis, which are also involved in the development of AS. Targeting TLRs and their regulated inflammatory events could be a promising new strategy for the treatment of atherosclerotic CVDs. Novel drugs that exert therapeutic effects on AS through TLRs and their related pathways are increasingly being developed. In this article, we comprehensively review the current knowledge of TLR signaling pathways in atherosclerosis and actively seek potential therapeutic strategies using TLRs as a breakthrough point in the prevention and therapy of atherosclerosis.

Prediction of the mechanisms of action of Qutan Huoxue decoction in non-alcoholic steatohepatitis (NASH): a network pharmacology study and experimental validation

CONTEXT

Qutan Huoxue decoction (QTHX) is used to treat non-alcoholic steatohepatitis (NASH) with good efficacy in the clinic. However, the mechanism is not clear yet.

OBJECTIVE

This study investigates the mechanism of QTHX in the treatment of NASH.

MATERIALS AND METHODS

Potential pathways of QTHX were predicted by network pharmacology. Fourty Sprague Dawley (SD) rats (half normal diet, half high-fat diet) were fed six to eight weeks, primary hepatocytes and Kupffer cells were extracted and co-cultured by the 0.4-micron trans well culture system. Then, the normal co-cultured cells were treated by normal serum, the NASH co-cultured cells were treated with various concentrations of QTHX-containing serum (0, 5, 7.5 or 10 μg/mL) for 24 h. The expression of targets were measured with Activity Fluorometric Assay, Western blot and PCR assay.

RESULTS

Network pharmacology indicated that liver-protective effect of QTHX was associated with its anti-inflammation response, oxidative stress, and lipid receptor signalling. 10 μg/mL QTHX significantly reduced the inflammation response and lipid levels in primary hepatocytes (ALT: 46.43 ± 2.76 U/L, AST: 13.96 ± 1.08 U/L, TG: 0.25 ± 0.01 mmol/L, TC: 0.14 ± 0.05 mmol/L), comparing with 0 μg/mL NASH group (ALT: 148 ± 9.22 U/L, AST: 53.02 ± 2.30 U/L, TG: 0.74 ± 0.07 mmol/L, TC: 0.91 ± 0.07 mmol/L) (p < 0.01). Meanwhile, QTHX increased expression of SOCS1 and decreased expression of TLR4, Myd88, NF-κB.

CONCLUSIONS

The study suggested that QTHX treats NASH in rats by activating the SCOS1/NF-κB/TLR4 pathway, suggesting QTHX could be further developed as a potential liver-protecting agent.

Modulating intestinal barrier function by sphingosine-1-phosphate receptor 1 specific agonist SEW2871 attenuated ANIT-induced cholestatic hepatitis via the gut-liver axis

Bile acid (BA) homeostasis throughout the enterohepatic circulation system is a guarantee of liver physiological functions. BA circulation disorders is one of the characteristic clinical manifestations of cholestasis, and have a closely relationship with intestinal barrier function, especially ileum. Here, our in vivo and in vitro studies showed that intestinal tight junctions (TJs) were disrupted by α-naphthylisothiocyanate (ANIT), which also down-regulated the protein expression of sphingosine-1-phosphate receptor 1 (S1PR1) in the top of villus of mice ileum. Activating S1PR1 by specific agonist SEW2871 could improve TJs via inhibiting ERK1/2/LKB1/AMPK signaling pathway in the ileum of ANIT-treated mice and ANIT-cultured Caco-2 cells. SEW2871 not only regained ileum TJs by activating S1PR1 in the epithelial cells of ileum mucosa, but also recovered ileum barrier function, which was further verified by the recovered BA homeostasis in mice ileum (content and tissue) by using of high-performance liquid chromatographytandem mass spectrometry (LC-MS/MS). Subsequently, the improved intestinal injury and inflammation further strengthened that SEW2871 modulated intestinal barrier function in ANIT-treated mice. Finally, our data revealed that along with the down-regulated levels of serum lipopolysaccharides (LPS), SEW2871 improved liver function and relieved hepatitis via blocking TLR4/MyD88/NF-kB signaling pathway in ANIT-treated mice. In conclusion, these results demonstrated that activating intestinal S1PR1 by SEW2871 could modulate intestinal barrier function, leading to the improvement of cholestatic hepatitis in ANIT-treated mice via the "gut-liver" axis.

Gut microbiota-mediated IL-22 alleviates metabolic inflammation

Low-grade chronic inflammation, also known as metabolic inflammation, promotes the development of metabolic diseases. Increasing evidence suggests that changes in gut microbes and metabolites disrupt the integrity of the gut barrier and exert significant effects on the metabolism of various tissues, including the liver and adipose tissue, thereby contributing to metabolic inflammation. We observed that IL-22 is a key signaling molecule that serves as a bridge between intestinal microbes and the host, effectively alleviating metabolic inflammation by modulating the host immunomodulatory network. Here, we focused on elucidating the underlying mechanisms by which the gut microbiota and their metabolites reduce inflammation via IL-22, highlighting the favorable impact of IL-22 on metabolic inflammation. Furthermore, we discuss the potential of IL-22 as a therapeutic target for the management of metabolic inflammation and related diseases.

Genomic annotation for vaccine target identification and immunoinformatics-guided multi-epitope-based vaccine design against Songling virus through screening its whole genome encoded proteins

Songling virus (SGLV), a newly discovered tick-borne orthonairovirus, was recently identified in human spleen tissue. It exhibits cytopathic effects in human hepatoma cells and is associated with clinical symptoms including headache, fever, depression, fatigue, and dizziness, but no treatments or vaccines exist for this pathogenic virus. In the current study, immunoinformatics techniques were employed to identify potential vaccine targets within SGLV by comprehensively analyzing SGLV proteins. Four proteins were chosen based on specific thresholds to identify B-cell and T-cell epitopes, validated through IFN-γ epitopes. Six overlap MHC-I, MHC-II, and B cell epitopes were chosen to design a comprehensive vaccine candidate, ensuring 100% global coverage. These structures were paired with different adjuvants for broader protection against international strains. Vaccine constructions' 3D models were high-quality and validated by structural analysis. After molecular docking, SGLV-V4 was selected for further research due to its lowest binding energy (-66.26 kcal/mol) and its suitable immunological and physiochemical properties. The vaccine gene is expressed significantly in E. coli bacteria through in silico cloning. Immunological research and MD simulations supported its molecular stability and robust immune response within the host cell. These findings can potentially be used in designing safer and more effective experimental SGLV-V4 vaccines.