(+)-Catechin attenuates CCI-induced neuropathic pain in male rats by promoting the Nrf2 antioxidant pathway to inhibit ROS/TLR4/NF-κB-mediated activation of the NLRP3 inflammasome.

The objective of this study was to investigate the potential mechanisms by which (+)-catechin alleviates neuropathic pain. Thirty-two male Sprague-Dawley rats were divided into four groups: the sham group, the chronic constriction injury (CCI)group, the CCI+ ibuprofen group, and the CCI+ (+)-catechin group. CCI surgery induces thermal hyperalgesia in rats and (+)-catechin ameliorated CCI-induced thermal hyperalgesia and repaired damaged sciatic nerve in rats. CCI decreased SOD levels in male rat spinal cord dorsal horn and promoted MDA production, induced oxidative stress by increasing NOX4 levels and decreasing antioxidant enzyme HO-1 levels, and also increased protein levels of TLR4, p-NF-κB, NLRP3 inflammasome components, and IL-1ß. In contrast, (+)-catechin reversed the above results. In i vitro experiments, (+)-catechin reduced the generation of reactive oxygen species (ROS) in GMI-R1 cells after LPS stimulation and attenuated the co-expression of IBA-1 and NLRP3. It also showed significant inhibition of the NF-κB and NLRP3 inflammatory pathways and activation of the Nrf2-mediated antioxidant system. Overall, these findings suggest that (+)-catechin inhibits the activation of the NLRP3 inflammasome through the triggering of the Nrf2-induced antioxidant system, the inhibition of the TLR4/NF-κB pathway, and the production of ROS to alleviate CCI-induced neuropathic pain in male rats.

Xiaoyaosan against depression through suppressing LPS mediated TLR4/NLRP3 signaling pathway in "microbiota-gut-brain" axis.

ETHNOPHARMACOLOGICAL RELEVANCE: Depression impairs not only central nervous system, but also peripheral systems of the host. Gut microbiota has been proved to be involved in the pathogenesis of depression. Xiaoyaosan (XYS) has a history of over a thousand years in China for treating depression, dramatically alleviating anxiety, cognitive disorders, and especially gastrointestinal dysfunctions. Yet, it still just scratches the surface of the anti-depression mechanisms of XYS. AIM OF THE STUDY: This study aims to elucidate the mechanism of action of XYS from the perspective of "microbiota-gut-brain" axis. MATERIALS AND METHODS: We firstly evaluated the effects of XYS on the macroscopic behaviors of depressed rats that induced by chronic unpredictable mild stress (CUMS). Secondly, the effects of XYS on intestinal homeostasis of depressed rats were revealed by using dysbacteriosis model. Subsequently, the underlying mechanisms were demonstrated by 16S rRNA gene sequencing technology and molecular biology methods. Finally, correlation analysis and visualization of the anti-depression effects of XYS were performed from the "microbiota - gut - brain" perspective. RESULTS: Our data indicated that XYS ameliorated the depression-like symptoms of CUMS rats, partly depending on the presence of gut microbiota. Furthermore, we illustrated that XYS reversed CUMS-induced gut dysbiosis of depressed rats in terms of decreasing Bacteroidetes/Firmicutes ratio and the abundances of Bacteroides, and Corynebacterium, while increasing the abundances of Lactobacillus and Adlercreutzia. The significant enrichment of Bacteroides and the level of lipopolysaccharides (LPS) suggested that depression damaged the immune responses and gut barrier. Mechanistically, XYS significantly down-regulated the expression levels of factors that involved in TLR4/NLRP3 signaling pathway in the colon and brain tissues of depressed rats. In addition, XYS significantly increased the levels of claudin 1 and ZO-1, showing that XYS positively maintained the integrity of gut and blood-brain barriers (BBB). CONCLUSION: Our study offers insights into the anti-depression effects of XYS through a lens of "microbiota-TLR4/NLRP3 signaling pathway-barriers", providing a foundation for enhancing clinical efficiency and enriching drug selection, and contributing to our understanding of the mechanisms of traditional Chinese medicines (TCMs) in treating depression.

TLR4/TNFR1 blockade suppresses STAT1/STAT3 expression and increases SOCS3 expression in modulation of LPS-induced macrophage responses.

Due to the urgent need to create appropriate treatment techniques, which are currently unavailable, LPS-induced sepsis has become a serious concern on a global scale. The primary active component in the pathophysiology of inflammatory diseases such as sepsis is the Gram-negative bacterial lipopolysaccharide (LPS). LPS interacts with cell surface TLR4 in macrophages, causing the formation of reactive oxygen species (ROS), TNF-α, IL-1ß and oxidative stress. It also significantly activates the MAPKs and NF-κB pathway. Excessive production of pro-inflammatory cytokines is one of the primary characteristic features in the onset and progression of inflammation. Cytokines mainly signal through the JAK/STAT pathway. We hypothesize that blocking of TLR4 along with TNFR1 might be beneficial in suppressing the effects of STAT1/STAT3 due to the stimulation of SOCS3 proteins. Prior to the LPS challenge, the macrophages were treated with antibodies against TLR4 and TNFR1 either individually or in combination. On analysis of the macrophage populations by flowcytometry, it was seen that receptor blockade facilitated the phenotypic shift of the M1 macrophages towards M2 resulting in lowered oxidative stress. Blocking of TLR4/TNFR1 upregulated the SOCS3 and mTOR expressions that enabled the transition of inflammatory M1 macrophages towards the anti-inflammatory M2 phenotype, which might be crucial in curbing the inflammatory responses. Also the reduction in the production of inflammatory cytokines such as IL-6, IL-1ß due to the reduction in the activation of the STAT1 and STAT3 molecules was observed in our combination treatment group. All these results indicated that neutralization of both TLR4 and TNFR1 might provide new insights in establishing an alternative therapeutic strategy for LPS-sepsis.

Temporal Dissociation of COX-2-Dependent Arachidonic Acid and 2-Arachidonoylglycerol Metabolism in RAW264.7 Macrophages.

Cyclooxygenase-2 converts arachidonic acid (AA) to prostaglandins (PGs) and the endocannabinoid, 2-arachidonoylglycerol (2-AG), to PG glyceryl esters (PG-Gs). The physiological function of PG biosynthesis has been extensively studied, but the importance of the more recently discovered PG-G synthetic pathway remains incompletely defined. This disparity is due in part to a lack of knowledge of the physiological conditions under which PG-G biosynthesis occurs. We have discovered that RAW264.7 macrophages stimulated with Kdo2-lipid A (KLA) produce primarily PGs within the first 12 h followed by robust PG-G synthesis between 12 h and 24 h. We suggest that the amount of PG-Gs quantified is less than actually synthesized, because PG-Gs are subject to a significant level of hydrolysis during the time course of synthesis. Inhibition of cytosolic phospholipase A2 (cPLA2) by giripladib does not accelerate PG-G synthesis, suggesting the differential time course of PG and PG-G synthesis is not due to competition between AA and 2-AG. The late-phase PG-G formation is accompanied by an increase in the level of 2-AG and a concomitant decrease in 18:0-20:4 diacylglycerol (DAG). Inhibition of DAG lipases by KT-172 decreases the levels of 2-AG and PG-Gs, indicating that the DAG-lipase pathway is involved in delayed 2-AG metabolism/PG-G synthesis. These results demonstrate that physiologically significant levels of PG-Gs are produced by activated RAW264.7 macrophages well after the production of PGs plateaus.

Pterostilbene Alleviates Dextran Sodium Sulfate (DSS)-Induced Intestinal Barrier Dysfunction Involving Suppression of a S100A8-TLR-4-NF-κB Signaling Cascade.

Intestinal barrier hemostasis is the key to health. As a resveratrol analogue, pterostilbene (PT) has been reported to prevent dextran sodium sulfate (DSS)-induced intestinal barrier dysfunction mainly associated with the intestinal NF-κB signaling pathway. However, the exact underlying mechanisms are not yet well-defined yet. In this study, we performed RNA-sequencing analysis and unexpectedly found that alarmin S100A8 sensitively responded to DSS-induced intestinal injury. Accordingly, histologic assessments suggested that the high expression of S100A8 was accompanied by increased intestinal infiltration of macrophages, upregulated intestinal epithelial Toll-like receptor 4 (TLR-4), and activated NF-κB signaling pathway. Interestingly, the above phenomena were effectively counteracted upon the addition of PT. Furthermore, by using a coculture system of macrophage THP-1 cells and HT-29 colon cells, we identified macrophage-secreted S100A8 activated intestinal epithelial NF-κB signaling pathway through TLR-4. Taken together, these findings suggested that PT ameliorated DSS-induced intestinal barrier injury through suppression of the macrophage S100A8-intestinal epithelial TLR-4-NF-κB signaling cascade.

Artemvulactone E isolated from Artemisia vulgaris L. ameliorates lipopolysaccharide-induced inflammation in both RAW264.7 and zebrafish model.

Introduction: Natural plants are valuable resources for exploring new bioactive compounds. Artemisia vulgaris L. is a traditional Chinese medicinal herb that has been historically used for treating multiple diseases. Active compounds isolated and extracted from A. vulgaris L. typically possess immunomodulatory and anti-inflammatory properties. Artemvulactone E (AE) is a new sesquiterpene lactone isolated and extracted from A. vulgaris L. with unclear biological activities. Methods: The immunoregulatory effects of AE on macrophages were assessed by ELISA, RT-qPCR, immunofluorescence, and western blot assay. The effect of AE on lipopolysaccharide (LPS) -relates signaling pathways was examined by western blot assay. In zebrafish models, the larvae were yolk-microinjected with LPS to establish inflammation model and the effect of AE was evaluated by determining the survival rate, heart rate, yolk sac edema size, neutrophils and macrophages infiltration of zebrafish. The interaction between AE and Toll-like receptor 4 (TLR4) was examined by molecular docking and dynamic stimulation. Results: AE reduced the expression and secretion of pro-inflammatory cytokines (TNF-α and IL-6), inflammatory mediators iNOS and COX-2, as well as decreases the production of intracellular NO and ROS in LPS-stimulated macrophages. In addition, AE exerted its anti-inflammatory effect synergistically by inhibiting MAPK/JAK/STAT3-NF-κB signaling pathways. Furthermore, AE enhanced the survival rate and attenuated inflammatory response in zebrafish embryos treated with LPS. Finally, the molecular dynamics results indicate that AE forms stable complexes with LPS receptor TLR4 through the Ser127 residue, thus completely impairing the subsequent activation of MAPK-NF-κB signaling. Conclusion: AE exhibits notable anti-inflammatory activity and represents as a potential agent for treating inflammation-associated diseases.

An arabinoxylan (AOP70-1) isolated from Alpinia oxyphylla alleviates neuroinflammation and neurotoxicity by TLR4/MyD88/NF-κB pathway.

Alpinia oxyphylla is famous for its neuroprotective and memory-improving effects. A crude polysaccharide AO70 from A. oxyphylla remarkably ameliorated neuroinflammation and cognitive dysfunction in Alzheimer's disease mice. This study aimed to explore the bioactive component of AO70 and its mechanism of action. A homogeneous polysaccharide (AOP70-1) rich in arabinose and xylose was purified from AO70, which was consisted of α-L-Araf-(1→, →5)-α-L-Araf-(1→, ß-D-Xylp-(1→,→2,4)-ß-D-Xylp-(1→, →2,3,4)-ß-D-Xylp-(1→, α-L-Rhap-(1→, α-D-Manp-(1→, →4)-α-D-Glcp-(1→, →4)-α-D-GlcpA-(1→, ß-D-Galp-(1→, →2)-α-D-Galp-(1→, →6)-α-D-Galp-(1 → and →3,6)-α-D-Manp-(1→. AOP70-1 (2.5, 5, 10 µM) significantly suppressed NO, IL-1ß, and TNF-α production in a concentration-dependent manner and inhibited the migration of BV2 microglia to normal levels. AOP70-1 inhibited LPS-mediated activation of Toll-like receptor 4 (TLR4), myeloid differentiation primary response protein (MyD88), and nuclear factor kappa B (NF-κB). Moreover, AOP70-1 exerted neuroprotection on SH-SY5Y cells and primary neurons by reducing neuronal apoptosis (72 %, 44 %), alleviating ROS accumulation (63 %, 55 %), and improving mitochondrial membrane potential (63 %, 77 %). Overall, AOP70-1 is one of the major bioactive components in AO70 from A. oxyphylla, which has great potential in the prevention and treatment of neuroinflammation.

Melatonin modulates TLR4/MyD88/NF-κB signaling pathway to ameliorate cognitive impairment in sleep-deprived rats.

Sleep deprivation (SD) is commonplace in today's fast-paced society. SD is a severe public health problem globally since it may cause cognitive decline and even neurodegenerative disorders like Alzheimer's disease. Melatonin (MT) is a natural chemical secreted by the pineal gland with neuroprotective effects. The purpose of this study was to investigate the protective effect and mechanism of MT on chronic sleep deprivation-induced cognitive impairment. A 3-week modified multi-platform method was used to create the SD rat model. The Morris water maze test (MWM), Tissue staining (including Hematoxylin and Eosin (H & E) staining, Nissl staining, and immunofluorescence), Western blot, Enzyme-linked immunosorbent assay (ELISA), and Quantitative real-time polymerase chain reaction (qPCR) were used to investigate the protective effect and mechanism of MT in ameliorating cognitive impairment in SD rats. The results showed that MT (50 and 100 mg/kg) significantly improved cognitive function in rats, as evidenced by a shortening of escape latency and increased time of crossing the platform and time spent in the quadrant. Additionally, MT therapy alleviated hippocampus neurodegeneration and neuronal loss while lowering levels of pathogenic factors (LPS) and inflammatory indicators (IL-1ß, IL-6, TNF-α, iNOS, and COX2). Furthermore, MT treatment reversed the high expression of Aß42 and Iba1 as well as the low expression of ZO-1 and occludin, and inhibited the SD-induced TLR4/MyD88/NF-κB signaling pathway. In summary, MT ameliorated spatial recognition and learning memory dysfunction in SD rats by reducing neuroinflammation and increasing neuroprotection while inhibiting the TLR4/MyD88/NF-κB signaling pathway. Our study supports the use of MT as an alternate treatment for SD with cognitive impairment.

The protective effect of dulcitol on lipopolysaccharide-induced intestinal injury in piglets: mechanistic insights.

This study investigated the protective effect of dulcitol on LPS-induced intestinal injury in piglets and explored the underlying molecular mechanisms. A total of 108 piglets were divided into three groups: CON, LPS, and DUL. The CON and LPS groups were fed a basal diet, the DUL group was fed a diet supplementation with 500 mg/kg dulcitol. On day 29, 6 piglets in the LPS and DUL groups were injected with 100 µg/kg BW of LPS. At 4 h post-challenge, all pigs were slaughtered, and colonic samples were collected. Results showed that dulcitol supplementation boosted intestinal barrier function in LPS-challenged piglets by enhancing intestinal morphology and integrity, and increasing the gene expression of zonula occludens-1, claudin-1, and occludin in the colonic mucosa (P <0.05). Metabolomics showed DUL supplementation mainly increased (P <0.05) the metabolites related to steroid and vitamin metabolism (Cholesterol and Vitamin C). Proteomics showed that dulcitol supplementation altered the protein expression involved in maintaining barrier integrity (FN1, CADM1, and PARD3), inhibiting inflammatory response (SLP1, SFN, and IRF3), and apoptosis (including FAS, ING1, BTK, MTHFR, NOX, and P53BP2) in LPS-challenged piglets (P <0.05). Additionally, dulcitol addition also suppressed the TLR4/NF-κB signaling pathway and apoptosis in mRNA and protein levels. Dulcitol increased the abundance of short-chain fatty acid-producing bacteria (Lactobacillus, Blautia, and Faecalibacterium) at the genus level, but decreased the relative abundance of Proteobacteria at the phylum level and Pseudomonas and Delftia at the genus level in piglets (P < 0.05). In conclusion, these results suggested that the addition of dulcitol alleviated LPS-induced intestinal barrier injury in piglets, probably by maintaining its integrity, inhibiting the TLR4/NF-κB signaling pathways and apoptosis, and modulating the gut microbiota. Therefore, dulcitol can be considered a potential dietary additive for improving intestinal health in pig models.

RNF149 negatively regulates LPS/TLR4 signal transduction by ubiquitination-mediated CD63 degradation.

This study aims to investigate the role of RNF149 and tetraspanin CD63 in lipopolysaccharide/Toll-like receptor 4 (LPS/TLR4) signal transduction. TNF-α was assessed using enzyme-linked immunosorbent assay. The distribution of TLR4 was examined through flow cytometry after CD63 knockdown. Real-time polymerase chain reaction was used to analyze the expression of the target genes RNF149 and CD63 under different conditions. Western blotting was employed to detect gene expression, while immunoprecipitation and confocal microscopy were used to evaluate protein interactions. Transcriptome array data from stimulated monocytes (GSE7547) was obtained from GEO and subjected to bioinformatic analysis. It is suggested that CD63 may serve as a substrate of RNF149, with RNF149 capable of directly interacting with CD63. RNF149 degrades CD63 through covalent modification of CD63 at lysine 29 of the ubiquitin monomer, leading to the formation of a multiubiquitin chain. Both RNF149 and CD63 interact with TLR4, with CD63 promoting LPS/TLR4 signaling and RNF149 inhibits it. CD63 does not impact the distribution of TLR4 on the cell surface and does not directly interact with TIRAP, IRAK4, or TRAF6, but does interact with Myd88.RNF149 plays a negative regulatory role in LPS/TLR4 signal transduction by mediating ubiquitination-induced CD63 degradation.

Interaction of toll-like receptors and ACE-2 with different variants of SARS-CoV-2: A computational analysis.

Introduction: Computational studies were performed to investigate the unknown status of endosomal and cell surface receptors in SARS-CoV-2 infection. The interactions between Toll-like receptors (TLRs)- 4/7/8/9 or ACE2 receptor and different SARS-CoV-2 variants were investigated. Methods: The RNA motifs for TLR7, TLR8 and a CpG motif for TLR9 were analyzed in different variants. Molecular docking and molecular dynamics (MD) simulations were performed to investigate receptor-ligand interactions. Results: The number of motifs recognized by TLR7/8/9 in the Alpha, Delta and Iranian variants was lower than in the wild type (WT). Docking analysis revealed that the Alpha, Delta and some Iranian spike variants had a higher affinity for ACE2 and TLR4 than the WT, which may account for their higher transmission rate. The MD simulation also showed differences in stability and structure size between the variants and the WT, indicating potential variations in viral load. Conclusion: It appears that Alpha and some Iranian isolates are the variants of concern due to their higher transmissibility and rapid spread. The Delta mutant is also a variant of concern, not only because of its closer interaction with ACE2, but also with TLR4. Our results emphasize the importance of ACE2 and TLR4, rather than endosomal TLRs, in mediating the effects of different viral mutations and suggest their potential therapeutic applications.

Intranasal administration of a synthetic TLR4 agonist INI-2004 significantly reduces allergy symptoms following therapeutic administration in a murine model of allergic sensitization.

Introduction: Atopic diseases have been steadily increasing over the past decades and effective disease-modifying treatment options are urgently needed. These studies introduce a novel synthetic Toll-like receptor 4 (TLR4) agonist, INI-2004, with remarkable efficacy as a therapeutic intranasal treatment for seasonal allergic rhinitis. Methods: Using a murine airway allergic sensitization model, the impact of INI-2004 on allergic responses was assessed. Results: One or two intranasal doses of INI-2004 significantly reduced airway resistance, eosinophil influx, and Th2 cytokine production - providing strong evidence of allergic desensitization. Further investigations revealed that a liposomal formulation of INI-2004 exhibited better safety and efficacy profiles compared to aqueous formulations. Importantly, the liposomal formulation demonstrated a 1000-fold increase in the maximum tolerated intravenous dose in pigs. Pre-clinical GLP toxicology studies in rats and pigs confirmed the safety of liposomal INI-2004, supporting its selection for human clinical trials. Discussion: These findings lay the groundwork for the ongoing clinical evaluation of INI-2004 in allergic rhinitis as a stand-alone therapy for individuals poly-sensitized to multiple seasonal allergens. The study underscores the significance of innovative immunotherapy approaches in reshaping the landscape of allergic rhinitis management.

Lipopolysaccharide-induced bacterial infection model: microRNA-370-3p participates in the anti-infection response by targeting the macrophage TLR4-NLRP3 caspase-1 cellular pyroptosis pathway.

OBJECTIVE: To explore the effect of miR-370-3p on LPS triggering, in particular its involvement in disease progression by targeting the TLR4-NLRP3-caspase-1 cellular pyroptosis pathway in macrophages. METHODS: Human macrophage RAW264.7 was divided into 6 groups: control, LPS, LPS + inhibitor-NC, LPS + miR-370-3p inhibitor, LPS + mimics-NC and LPS + miR-370-3p mimics. RT-qPCR was used to detect the expression level of miR-370-3p and analyzed comparatively. CCK-8 and flow cytometry assays were used to detect cell viability and apoptosis. ELISA assay was used to detect the levels of IL-1ß and TNF-α in the supernatant of the cells. The WB assay was used to detect TLR4, NLRP3, Caspase-1 and GSDMD levels. RESULTS: After LPS induction, macrophage miR-370-3p levels decreased, cell viability decreased, and apoptosis increased. At the same time, the levels of TLR4, NLRP3, Caspase-1 and GSDMD increased in the cells, and the levels of IL-1ß and TNF-α increased in the cell supernatant. Compared with the LPS group, the significantly higher expression level of miR-370-3p in the cells of the LPS + miR-370-3p mimics group was accompanied by significantly higher cell viability, significantly lower apoptosis rate, significantly lower levels of TLR4, NLRP3, Caspase-1, and GSDMD in the cells, and significantly lower levels of IL-1ß and TNF-α in the cell supernatant. CONCLUSION: MiR-370-3p may be involved in anti-infective immune responses by targeting and inhibiting the macrophage TLR4-NLRP3-caspase-1 cellular pyroptosis pathway.

Rutin mitigates acetic acid-induced ulcerative colitis: novel coloprotective mechanism.

Background: Ulcerative colitis, an inflammatory bowel disease, is characterized by a status of oxidative stress and inflammation. Rutin is a natural flavonoid with many pharmacological activities and its role in acetic acid-induced ulcerative colitis through the high mobility group B1 (HMGB1)/ toll-like receptor-4 (TLR4)/ myeloid differentiation primary response protein 88 (MYD88)/ nuclear factor-kB (NF-kB) signaling pathway needs to be explored. Methods: Four experimental groups were divided into control group, rutin group: treated with 100 mg/kg/day rutin orally for 10 days, acetic acid (AA) group: given intracolonic instillation of AA to induce ulcerative colitis, and acetic acid with rutin treatment (AA/Rutin) group. Results: Acetic acid caused a marked increase in the colon weight/length ratio and induced colonic histopathological changes, leading to a marked rise in the colonic histopathological scores. Acetic acid exhibited a significant rise in LDH and CRP serum levels as well as TOS colonic levels, accompanied by a marked decline in TAS colonic contents compared to the control group. Moreover, AA-induced activation of the HMGB1/TLR4/MYD88/NF-kB signaling pathway. Rutin demonstrated a significant decrease in the colon weight/length ratio, ameliorated the colonic histopathological changes induced by AA, and exhibited a marked decline in the colonic histopathological scores. Rutin showed a significant decrease in serum LDH, and CRP levels as well as colonic TOS contents when compared with the AA group. Rutin suppressed the colonic activation of the HMGB1/TLR4/MYD88/NF-kB signaling pathway. Conclusion: Rutin could be a promising coloprotective agent against AA-induced ulcerative colitis by targeting the HMGB1/TLR4/MYD88/NF-kB signaling pathway.

The activation of TLR4-MyD88 signaling promotes hepatic dysfunction and fibrotic changes in SD rats resulting from prolonged exposure to sodium arsenite.

Arsenic, a poisonous metalloid element, is linked to liver diseases, but the exactmechanisms for this process are not yet to be completely elucidated. Toll like receptor 4 (TLR4), acting as a pathogenic pattern recognition receptor, plays a pivotal role in various inflammatory diseases via the myeloid differentiation factor 88 (MyD88) pathway. This study aims to investigate the involvement of the TLR4-MyD88 signaling pathway in liver injury induced by prolonged exposure to sodium arsenite (NaAsO2) in Sprague-Dawley rats. Our research findings demonstratethe activation of TLR4-MyD88 signaling pathway in long-term NaAsO2-exposed rat liver tissues, leading to a significant release of inflammatory factors, which suggests its potential involvement in the pathogenesis of NaAsO2-induced liver injury. We further administered lipopolysaccharide (LPS), a natural ligand of TLR4, and TAK-242, a specific inhibitor of TLR4, to rats in order to validate the specific involvement of the TLR4-MyD88 signaling pathway in NaAsO2-induced liver injury. The results showed that, 1 mg/kg.bw LPS treatment significantly activated TLR4-MyD88 signalling pathway and its mediated pro-inflammatory factors, leading to up-regulation of activation indicators in hepatic stellate cells (HSCs) as well as increased secretion levels of extracellular matrix (ECM) in the liver, and ultimately induced liver fibrosis and dysfunction in rats. Relevantly, subsequent administration of 0.5 mg/kg.bw TAK-242 significantly attenuated the expression levels of TLR4 and its associated proteins, mitigated collagen deposition, and partially improved liver fibrosis and dysfunction caused by NaAsO2 in rats. Our study fully confirms the pivotal role of the TLR4-MyD88 signaling in promoting liver injury induced by NaAsO2, thereby providing a novel molecular target for preventing and treating patients with arsenic poisoning-related liver injury.

Targeted Liposomal Co-delivery of an Immunogenic Cell Death Inducer and a Toll-Like Receptor 4 Agonist for Enhanced Cancer Chemo-immunotherapy.

Anticancer chemo-immunotherapy has gained considerable attention across various scientific domains as a prospective approach for the comprehensive eradication of malignant tumors. Recent research has particularly been focused on traditional anthracycline chemo drugs, such as doxorubicin and mitoxantrone. These compounds trigger apoptosis in tumor cells and evoke immunogenic cell death (ICD). ICD is a pivotal initiator of the cancer-immunity cycle by facilitating the release of damage-associated molecular patterns (DAMPs). The resultant DAMPs released from cancer cells effectively activate the immune system, resulting in an increase in tumor-infiltrating T cells. In this study, we have innovated a co-delivery strategy involving folate-modified liposomes to deliver doxorubicin and monophosphoryl lipid A (MPLA) simultaneously to tumor tissue. The engineered liposomes exploit the overexpression of folate receptors within the tumor tissues. Delivered doxorubicin initiates ICD at the tumor cells, further enhancing the immunogenic stimulus. Additionally, MPLA helps T cell priming by activating antigen-presenting cells. This intricate interplay culminates in a synergistic effect, ultimately resulting in an augmented and potentiated anticancer chemo-immunotherapeutic liposomal treatment.

Anadenanthera colubrina regulated LPS-induced inflammation by suppressing NF-κB and p38-MAPK signaling pathways.

We aimed to determine the chemical profile and unveil Anadenanthera colubrina (Vell.) Brenan standardized extract effects on inflammatory cytokines expression and key proteins from immunoregulating signaling pathways on LPS-induced THP-1 monocyte. Using the RT-PCR and Luminex Assays, we planned to show the gene expression and the levels of IL-8, IL-1ß, and IL-10 inflammatory cytokines. Key proteins of NF-κB and MAPK transduction signaling pathways (NF-κB, p-38, p-NF-κB, and p-p38) were detected by Simple Western. Using HPLC-ESI-MSn (High-Performance Liquid-Chromatography) and HPLC-HRESIMS, we showed the profile of the extract that includes an opus of flavonoids, including the catechins, quercetin, kaempferol, and the proanthocyanidins. Cell viability was unaffected up to 250 µg/mL of the extract (LD50 = 978.7 µg/mL). Thereafter, the extract's impact on the cytokine became clear. Upon LPS stimuli, in the presence of the extract, gene expression of IL-1ß and IL-10 were downregulated and the cytokines expression of IL-1ß and IL-10 were down an upregulated respectively. The extract is involved in TLR-4-related NF-κB/MAPK pathways; it ignited phosphorylation of p38 and NF-κB, orchestrating a reduced signal intensity. Therefore, Anadenanthera colubrina's showed low cytotoxicity and profound influence as a protector against the inflammation, modulating IL-1ß and IL-10 inflammatory cytokines gene expression and secretion by regulating intracellular NF-κB and p38-MAPK signaling pathways.

Polygala tenuifolia willd. Extract alleviates LPS-induced acute lung injury in rats via TLR4/NF-κB pathway and NLRP3 inflammasome suppression.

BACKGROUND: Acute lung injury (ALI) has received considerable attention in the field of critical care as it can lead to high mortality rates. Polygala tenuifolia, a traditional Chinese medicine with strong expectorant properties, can be used to treat pneumonia. Owing to the complexity of its composition, the main active ingredient is not yet known. Thus, there is a need to identify its constituent compounds and mechanism of action in the treatment of ALI using advanced technological means. PURPOSE: We investigated the anti-inflammatory mechanism and constituent compounds with regard to the effect of P. tenuifolia Willd. extract (EPT) in lipopolysaccharide (LPS)-induced ALI in vivo and in vitro. METHODS: The UHPLC-Q-Exactive Orbitrap MS technology was used to investigate the chemical profile of EPT. Network pharmacology was used to predict the targets and pathways of action of EPT in ALI, and molecular docking was used to validate the binding of polygalacic acid to Toll-like receptor (TLR) 4. The main compounds were determined using LC-MS. A rat model of LPS-induced ALI was established, and THP-1 cells were stimulated with LPS and adenosine triphosphate (ATP) to construct an in vitro model. Pathological changes were observed using hematoxylin and eosin staining, Wright-Giemsa staining, and immunohistochemistry. The expression of inflammatory factors (NE, MPO, Ly-6 G, TNF-α, IL-1ß, IL-6, and iNOS) was determined using enzyme-linked immunosorbent assay, real-time fluorescence quantitative polymerase chain reaction, and western blotting. The LPS + ATP-induced inflammation model in THP-1 cells was used to verify the in vivo experimental results. RESULTS: Ninety-nine compounds were identified or tentatively deduced from EPT. Using network pharmacology, we found that TLR4/NF-κB may be a relevant pathway for the prevention and treatment of ALI by EPT. Polygalacic acid in EPT may be a potential active ingredient. EPT could alleviate LPS-induced histopathological lung damage and reduce the wet/dry lung weight ratio in the rat model of ALI. Moreover, EPT decreased the white blood cell and neutrophil counts in the bronchoalveolar lavage fluid and decreased the expression of genes and proteins of relevant inflammatory factors (NE, MPO, Ly-6 G, TNF-α, IL-1ß, IL-6, and iNOS) in lung tissues. It also increased the expression of endothelial-type nitric oxide synthase expression. Western blotting confirmed that EPT may affect TLR4/NF-κB and NLRP3 signaling pathways in vivo. Similar results were obtained in THP-1 cells. CONCLUSION: EPT reduced the release of inflammatory factors by affecting TLR4/NF-κB and NLRP3 signaling pathways, thereby attenuating the inflammatory response of ALI. Polygalacic acid is the likely compounds responsible for these effects.

An integrated network pharmacology approach reveals that Ampelopsis grossedentata improves alcoholic liver disease via TLR4/NF-κB/MLKL pathway.

BACKGROUND: Alcohol-related liver damage is the most prevalent chronic liver disease, which creates a heavy public health burden worldwide. The leaves of Ampelopsis grossedentata have been considered a popular tea and traditional herbal medicine in China for more than one thousand years, and possess anti-inflammatory, antioxidative, hepatoprotective, and antiviral activities. PURPOSE: We explored the protective effects of Ampelopsis grossedentata extract (AGE) against chronic alcohol-induced hepatic injury (alcoholic liver disease, ALD), aiming to elucidate its underlying mechanisms. METHODS: Firstly, UPLC-Q/TOF-MS analysis and network pharmacology were used to identify the constituents and elucidate the potential mechanisms of AGE against ALD. Secondly, C57BL/6 mice were pair-fed the Lieber-DeCarli diet containing either isocaloric maltodextrin or ethanol, AGE (150 and 300 mg/kg/d) and silymarin (200 mg/kg) were administered to chronic ethanol-fed mice for 7 weeks to evaluate the hepatoprotective effects. Serum biochemical parameters were determined, hepatic and ileum sections were used for histologic examination, and levels of inflammatory cytokines and oxidative stress in the liver were examined. The potential molecular mechanisms of AGE in improving ALD were demonstrated by RNA-seq, Western blotting analysis, and immunofluorescence staining. RESULTS: Ten main constituents of AGE were identified using UPLC-Q/TOF-MS and 274 potential ALD-related targets were identified. The enriched KEGG pathways included Toll-like receptor signaling pathway, NF-κB signaling pathway, and necroptosis. Moreover, in vivo experimental studies demonstrated that AGE significantly reduced serum aminotransferase levels and improved pathological abnormalities after chronic ethanol intake. Meanwhile, AGE improved ALD in mice by down-regulating oxidative stress and inflammatory cytokines. Furthermore, AGE notably repaired damaged intestinal epithelial barrier and suppressed the production of gut-derived lipopolysaccharide by elevating intestinal tight junction protein expression. Subsequent RNA-seq and experimental validation indicated that AGE inhibited NF-κB nuclear translocation, suppressed IκB-α, RIPK3 and MLKL phosphorylation and alleviated hepatic necroptosis in mice. CONCLUSION: In this study, we have demonstrated for the first time that AGE protects against alcoholic liver disease by regulating the gut-liver axis and inhibiting the TLR4/NF-κB/MLKL-mediated necroptosis pathway. Therefore, our present work provides important experimental evidence for AGE as a promising candidate for protection against ALD.

Potential effects of Resatorvid and alpha lipoic acid on gentamicin-induced nephrotoxicity in rats.

Gentamicin is an aminoglycoside antibiotic with a rapid bactericidal effect on the treatment of many infections. However, its use at high concentrations for more than 7 days causes nephrotoxic side effects. This study investigated the potential of Resatorvid and alpha lipoic acid (ALA) in mitigating gentamicin-induced nephrotoxicity in rats, considering biochemical, histopathological, and molecular parameters. This study randomly distributed 34 Wistar albino rats into four groups: healthy control (n = 6), Gentamicin (80 mg/kg, n = 7), Gentamicin + Sham (%10 hydroalcoholic solution, n = 7), Gentamicin + Resatorvid (5 mg/kg, n = 7), and Gentamicin + ALA (100 mg/kg, n = 7). Resatorvid treatment led to a statistically significant decrease in urinary IL-18, KIM-1, and NGAL levels, whereas ALA treatment significantly reduced KIM-1 levels compared to the gentamicin-only group. Both Resatorvid and ALA showed partial reductions in urine creatinine levels. Moreover, treatments with Resatorvid and ALA resulted in statistically significant decreases in NRF-2, CAS-3, and NR4A2 expressions. However, only Resatorvid demonstrated a statistically significant decrease in NF-B expression. These findings highlight the potential of Resatorvid in ameliorating gentamicin-induced nephrotoxicity, thereby expanding the therapeutic utility of gentamicin and enhancing its efficacy against infections.