Exploration of Berberine Against Ulcerative Colitis via TLR4/NF-κB/HIF-1α Pathway by Bioinformatics and Experimental Validation.

Purpose: This study aimed to delineate the molecular processes underlying the therapeutic effects of berberine on UC by employing network pharmacology tactics, molecular docking, and dynamic simulations supported by empirical validations both in vivo and in vitro. Patients and Methods: We systematically screened potential targets and relevant pathways affected by berberine for UC treatment from comprehensive databases, including GeneCards, DisGeNET, and GEO. Molecular docking and simulation protocols were used to assess the interaction stability between berberine and its principal targets. The predictions were validated using both a DSS-induced UC mouse model and a lipopolysaccharide (LPS)-stimulated NCM460 cellular inflammation model. Results: Network pharmacology analysis revealed the regulatory effect of the TLR4/NF-κB/HIF-1α pathway in the ameliorative action of berberine in UC. Docking and simulation studies predicted the high-affinity interactions of berberine with pivotal targets: TLR4, NF-κB, HIF-1α, and the HIF inhibitor KC7F2. Moreover, in vivo analyses demonstrated that berberine attenuates clinical severity, as reflected by decreased disease activity index (DAI) scores, reduced weight loss, and mitigated intestinal inflammation in DSS-challenged mice. These outcomes include suppression of the proinflammatory cytokines IL-6 and TNF-α and downregulation of TLR4/NF-κB/HIF-1α mRNA and protein levels. Correspondingly, in vitro findings indicate that berberine decreases cellular inflammatory injury and suppresses TLR4/NF-κB/HIF-1α signaling, with notable effectiveness similar to that of the HIF-1α inhibitor KC7F2. Conclusion: Through network pharmacology analysis and experimental substantiation, this study confirmed that berberine enhances UC treatment outcomes by inhibiting the TLR4/NF-κB/HIF-1α axis, thereby mitigating inflammatory reactions and improving colonic pathology.

Protective effects of 17-ß-estradiol on liver injury: The role of TLR4 signaling pathway and inflammatory response.

Liver injury, a major global health issue, stems from various causes such as alcohol consumption, nonalcoholic steatohepatitis, obesity, diabetes, metabolic syndrome, hepatitis, and certain medications. The liver's unique susceptibility to ischemia and hypoxia, coupled with the critical role of the gut-liver axis in inflammation, underscores the need for effective therapeutic interventions. The study highlights E2's interaction with estrogen receptors (ERs) and its modulation of the Toll-like receptor 4 (TLR4) signaling pathway as key mechanisms in mitigating liver injury. Activation of TLR4 leads to the release of pro-inflammatory cytokines and chemokines, exacerbating liver inflammation and injury. E2 down-regulates TLR4 expression, reduces oxidative stress, and inhibits pro-inflammatory cytokines, thereby protecting the liver. Both classic (ERα and ERß) and non-classic [G protein-coupled estrogen receptor (GPER)] receptors are influenced by E2. ERα is particularly crucial for liver regeneration, preventing liver failure by promoting hepatocyte proliferation. Furthermore, E2 exerts anti-inflammatory, antioxidant, and anti-apoptotic effects by inhibiting cytokines such as IL-6, IL-1ß, TNF-α, and IL-17, and by reducing lipid peroxidation and free radical damage. The article calls for further clinical research to validate these findings and to develop estrogen-based treatments for liver injuries. Overall, the research emphasizes the significant potential of E2 as a therapeutic agent for liver injuries. It advocates for extensive clinical studies to validate E2 hepatoprotective properties and develop effective estrogen-based treatments.

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.

LPS exacerbates TRPV4-mediated itch through the intracellular TLR4-PI3K signalling.

Pruritus is often accompanied with bacterial infections, but the underlying mechanism is not fully understood. Although previous studies revealed that lipopolysaccharides (LPS) could directly activate TRPV4 channel and TRPV4 is involved in the generation of both acute itch and chronic itch, whether and how LPS affects TRPV4-mediated itch sensation remains unclear. Here, we showed that LPS-mediated TRPV4 sensitization exacerbated GSK101-induced scratching behaviour in mice. Moreover, this effect was compromised in TLR4-knockout mice, suggesting LPS acted through a TLR4-dependent mechanism. Mechanistically, LPS enhanced GSK101-evoked calcium influx in mouse ear skin cells and HEK293T cells transfected with TRPV4. Further, LPS sensitized TRPV4 channel through the intracellular TLR4-PI3K-AKT signalling. In summary, our study found a modulatory role of LPS in TRPV4 function and highlighted the TLR4-TRPV4 interaction in itch signal amplification.

Pig-Derived Probiotic Bacillus tequilensis YB-2 Alleviates Intestinal Inflammation and Intestinal Barrier Damage in Colitis Mice by Suppressing the TLR4/NF-κB Signaling Pathway.

The search for new probiotics has been regarded as an important approach to improving intestinal health in animals. Bacillus has many advantages, such as strong resistance to harmful external factors, wide distribution, and easy colonization of the intestine. Hence, this study aims to screen for a probiotic Bacillus strain that improves animal intestinal health and to elucidate its probiotic mechanism so as to provide probiotic resources for the development of feed-using probiotic formulations. In this research, a strain of Bacillus was isolated from adult pig feces and named B. tequilensis YB-2. In vitro probiotic experiments showed that B. tequilensis YB-2 had strong acid and bile salt resistance, indicating that this strain can customize in the intestine. To further explore the effect of B. tequilensis YB-2 upon animal intestinal health, DSS-induced murine colitis models were established, and the body weight, colonic morphology, inflammatory cytokines level, and intestinal-barrier- and TLR4/NF-κB-pathway-related protein were determined. The results showed that mice receiving drinking water with 3% DSS were found to develop colitis symptoms, including body weight loss and increased disease activity index (DAI); colon length and microvilli shedding were shortened; tight junctions were disrupted; goblet cells decreased; anti-inflammatory cytokines were inhibited; and pro-inflammatory cytokines and the TLR4/NF-κB signaling pathway were activated. Notably, orally received B. tequilensis YB-2 alleviated symptoms of DSS-induced colitis in mice. The above results indicated that B. tequilensis YB-2 was capable of improving colitis in mice by weakening inflammation and intestinal barrier damage, and its mechanism may involve the TLR4/NF-κB pathway. Overall, this research suggests that B. tequilensis YB-2 has the potential to serve as an animal feed additive to prevent intestinal inflammation.

Anti-Obesity Activity of Sanghuangporus vaninii by Inhibiting Inflammation in Mice Fed a High-Fat Diet.

Obesity is an unhealthy condition associated with various diseases characterized by excess fat accumulation. However, in China, the prevalence of obesity is 14.1%, and it remains challenging to achieve weight loss or resolve this issue through clinical interventions. Sanghuangpours vaninii (SPV) is a nutritional fungus with multiple pharmacological activities and serves as an ideal dietary intervention for combating obesity. In this study, a long-term high-fat diet (HFD) was administered to induce obesity in mice. Different doses of SPV and the positive drug simvastatin (SV) were administered to mice to explore their potential anti-obesity effects. SPV regulated weight, serum lipids, and adipocyte size while inhibiting inflammation and hepatic steatosis. Compared with the vehicle-treated HFD-fed mice, the lowest decreases in total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) were 9.72%, 9.29%, and 12.29%, respectively, and the lowest increase in high-density lipoprotein cholesterol (HDL-C) was 5.88% after treatment with different doses of SPV. With SPV treatment, the analysis of gut microbiota and serum lipids revealed a significant association between lipids and inflammation-related factors, specifically sphingomyelin. Moreover, Western blotting results showed that SPV regulated the toll-like receptor (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway in HFD-diet mice, which is related to inflammation and lipid metabolism. This research presents empirical proof of the impact of SPV therapy on obesity conditions.

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.

Effect of Early Inhibition of Toll-Like Receptor 4 on Hippocampal Plasticity in a Neonatal Rat Model of Hypoxic-Ischemic Brain Damage.

Hippocampal plasticity is closely related to physiological brain functions such as learning and memory. However, the effect of toll-like receptor 4 (TLR4) activation on hippocampal plasticity after neonatal hypoxic-ischaemic brain damage (HIBD) remains unclear. In our study, seven-day-old rat pups were randomly categorised into three groups: control, hypoxic-ischemia (HI), and HI + TAK-242 (TAK-242). The pups were ligated in the left common carotid artery and then subjected to hypoxia to establish the neonatal HIBD model.The expression of the TLR4 in the left hippocampus of the HI group was increased compared to the control group, while TAK-242 reduced the expression level at 3 days after HIBD. Additionally, TAK-242 reversed the increased Zea-Longa score, increased the left/right hippocampal weight ratio, and increased the number of Nissl-positive neurons in the hippocampal CA1 region compared to HI group at 3 days after HIBD. Pre-injection of TAK-242 alleviated the decrease in PSD95, Aggrecan and NR1, BDNF, CREB, and pCREB expression in the hippocampus at 24 h after HIBD. It also alleviated the decrease in PSD95, BDNF, and NR2A/NR1 expression in the hippocampus at 7 days after HIBD. Furthermore, Pre-injection of TAK-242 alleviated the decrease in NR2A/NR1 expression at 21 days after HIBD. Finally,TAK-242 increased the percentage of third-grade dendritic mushroom spines processes in the basal and apical segments of neurons in the hippocampal CA1 region at 21 days after HIBD.Therefore, we conclude that preinhibition of TLR4 prior to neonatal HIBD improved the plasticity of the hippocampus.

Surgery induces neurocognitive disorder via neuroinflammation and glymphatic dysfunction in middle-aged mice with brain lymphatic drainage impairment.

Background: Brain lymphatic drainage impairment is a prevalent characteristic in both aging and neurodegeneration. Surgery is more likely to induce excessive neuroinflammation and postoperative neurocognitive disorder (PND) among patients with aging and neurodegeneration. We hypothesized that surgical trauma may aggravate PND through preexisting cerebral lymphatic drainage impairment. However, there remains limited understanding about the role of surgery in changes of neurocognitive function in the populations with preoperative brain lymphatic drainage impairment. This study aims to expand our insight into surgery-induced glymphatic dysfunction, neuroinflammation and PND in middle-aged mice with preoperative brain lymphatic drainage impairment. Materials and methods: Deep cervical lymph nodes ligation (LdcLNs) was performed on middle-aged mice to establish preoperative brain lymphatic drainage impairment. A month later, laparotomy was performed on these mice with or without LdcLNs followed by analysis of brain neuroinflammation, glymphatic function, neuronal damage, and behavioral test. Results: LdcLNs disrupted meningeal lymphatic drainage. In middle-aged mice with LdcLNs, surgery exacerbated more serious glymphatic dysfunction accompanied by aggravation of A1 astrocytes activation and AQP4 depolarization. Furthermore, surgery caused neuronal damage via reducing expression of neuronal nuclei (NeuN), post-synaptic density protein 95 (PSD95) and synaptophysin (SYP), as well as impairment in exploratory behavior and spatial working memory in middle-aged mice with LdcLNs. Additionally, surgery induced neuroinflammation with elevated microglia activation and increased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6, as well as activated more expression of HMGB1/TLR-4/NF-κB pathway in middle-aged mice with LdcLNs. Conclusion: Surgery exacerbates neuroinflammation and glymphatic dysfunction, ultimately resulting in neuronal damage and neurocognitive disorder in middle-aged mice with preoperative brain lymphatic drainage impairment. These results suggest that brain lymphatic drainage impairment may be a deteriorating factor in the progression of PND, and restoring its function may serve as a potential strategy against PND.

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.

Immunomodulatory of sesquiterpenoids and sesquiterpenoid dimers-based toll-like receptor 4 (TLR4) from Dysoxylum parasiticum stem bark.

In recent decades, the interest in natural products with immunomodulatory properties has increased due to their therapeutic potential. These products have a wider range of pharmacological activities and demonstrate lower toxicity levels when compared to their synthetic counterparts. Therefore, this study aimed to investigate the immunomodulatory effects of sesquiterpenoids (SQs) and sesquiterpenoid dimers (SQDs) isolated from Dysoxylum parasiticum (Osbeck) Kosterm. stem bark on human and murine cells, particularly focusing on toll-like receptor 4 (TLR4). Utilizing the secreted alkaline phosphatase (SEAP) assay on engineered human and murine TLR4 of HEK-Blue cells, antagonist TLR4 compounds were identified, including SQs 6, 9, and 10, as well as SQDs 17 and 22. The results showed that 10-hydroxyl-15-oxo-α-cadinol (9) had a potent ability to reduce TLR4 activation induced by LPS stimulation, with minimal toxicity observed in both human and murine cells. The SEAP assay also revealed diverse immune regulatory effects for the same ligand. For instance, SQs 12, 14, and 16 transitioned from antagonism on human to murine TLR4. The SQs (4, 7, 11, and 15) and SQDs (18-20) offered partial antagonist effect exclusively on murine TLR4. Furthermore, these selected SQs and SQDs were assessed for their influence on the production of proinflammatory cytokines TNF-α, IL-1α, IL-1ß, and IL-6 of the NF-κB signaling pathway in human and murine macrophage cell lines, showing a dose-dependent manner. Additionally, a brief discussion on the structure-activity relationship was presented.

Xiaowugui decoction alleviates experimental rheumatoid arthritis by suppressing Rab5a-mediated TLR4 internalization in macrophages.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by exacerbated synovial inflammation and joint destruction. Recent studies suggest toll-like receptor 4 (TLR4) internalization facilitate inflammatory response of macrophage. The role of TLR4 internalization in the pathogenesis of RA is unknown. PURPOSE: To investigate the role and mechanism of TLR4 internalization in macrophage inflammatory response of RA and explore whether TLR4 internalization mediates the anti-arthritic effect of Xiaowugui (XWG) decoction, a patented herbal formula used in China. METHODS: The co-expression of TLR4 and the internalization marker, early endosome antigen 1 (EEA1), in the synovial samples of RA patients and joint tissue of collagen-induced arthritis (CIA) mice, were evaluated using immunofluorescence. The effect of Rab5a-mediated early internalization of TLR4 on the activation induced by lipopolysaccharide (LPS) in RAW264.7 cells was investigated using small interfering RNAs that act against Rab5a. CIA was induced in Rab5a-/- mice to evaluate the role of Rab5a in vivo. The disease progression and expression of Rab5a and TLR4 in the joint tissue were evaluated in CIA mice treated with XWG. Inflammatory factors production, TLR4 internalization, and activation of downstream signaling pathways were examined in RAW264.7 cells treated with XWG in vitro. RESULTS: The co-expression and co-localization of TLR4 and EEA1 were elevated in the synovial samples of RA patients and joint tissue of CIA mice. Pharmaceutical inhibition of TLR4 internalization reduced macrophages inflammatory responses induced by LPS. The co-expression and co-localization of Rab5a and TLR4 were significantly increased in macrophages treated with LPS. Silencing Rab5a reduced LPS-induced TLR4 internalization, inflammatory factors production, and phosphorylation of Jun N-terminal kinases (JNK) and p65. Genetic deletion of Rab5a inhibited TLR4 internalization and the development of arthritis in vivo. The co-expression of TLR4 and Rab5a was also elevated in the synovial samples of RA patients. XWG treatment of mice with CIA alleviated arthritis and reduced the co-expression of Rab5a and TLR4 in the joint tissue. XWG treatment of macrophage inhibited LPS-induced IL-6 and TNF-α production, co-expression of Rab5a and TLR4, and phosphorylation of JNK and p65. CONCLUSIONS: Our findings highlight the pathogenic role of TLR4 internalization in patients with RA and identify a novel Rab5a-dependent internalization pathway that promotes macrophage inflammatory response. XWG treatment demonstrated outstanding therapeutic effects in experimental arthritis, and targeting the Rab5a-mediated internalization of TLR4 may be the main underlying mechanism.

The Effects and Mechanisms of AM1241 in Alleviating Cerebral Ischemia-Reperfusion Injury.

OBJECTIVE: Research has shown that cerebral ischemia-reperfusion injury (CIRI) involves a series of physiological and pathological mechanisms, including inflammation, oxidative stress, and cell apoptosis. The cannabinoid receptor 2 agonist AM1241 has been found to have anti-inflammatory and anti-oxidative stress effects. However, it is unclear whether AM1241 has a protective effect against brain ischemia-reperfusion injury, and its underlying mechanisms are not yet known. METHODS: In this study, we investigated the anti-inflammatory, anti-oxidative stress, and anti-apoptotic effects of AM1241 and its mechanisms in BV2 cells stimulated with H2O2 and in a C57BL/6 mouse model of CIRI in vitro and in vivo, respectively. RESULTS: In vitro, AM1241 significantly inhibited the release of pro-inflammatory cytokines TNF-α and IL-6, reactive oxygen species (ROS), and the increase in Toll-like receptor 4/myeloid differentiation protein 2 (MD2/TLR4) complex induced by H2O2. Under H2O2 stimulation, MD2 overexpression resulted in increased levels of MD2/TLR4 complex, TNF-α, IL-6, NOX2, BAX, and Cleaved-Caspase3 (C-Caspase3), as well as the activation of the MAPK pathway and NF-κB, which were reversed by AM1241. In addition, molecular docking experiments showed that AM1241 directly interacted with MD2. Surface Plasmon Resonance (SPR) experiments further confirmed the binding of AM1241 to MD2. In vivo, AM1241 significantly attenuated neurofunctional impairment, brain edema, increased infarct volume, oxidative stress levels, and neuronal apoptosis in CIRI mice overexpressing MD2. CONCLUSION: Our study demonstrates for the first time that AM1241 alleviates mouse CIRI by inhibiting the MD2/TLR4 complex, exerting anti-inflammatory, anti-oxidative stress and anti-apoptotic effects.

Kinin B1 receptor and TLR4 interaction in inflammatory response.

OBJECTIVE: We aimed to broaden our understanding of a potential interaction between B1R and TLR4, considering earlier studies suggesting that lipopolysaccharide (LPS) may trigger B1R stimulation. METHODS: We assessed the impact of DBK and LPS on the membrane potential of thoracic aortas from C57BL/6, B1R, or TLR4 knockout mice. Additionally, we examined the staining patterns of these receptors in the thoracic aortas of C57BL/6 and in endothelial cells (HBMEC). RESULTS: DBK does not affect the resting membrane potential of aortic rings in C57BL/6 mice, but it hyperpolarizes preparations in B1KO and TLR4KO mice. The hyperpolarization mechanism in B1KO mice involves B2R, and the TLR4KO response is independent of cytoplasmic calcium influx but relies on potassium channels. Conversely, LPS hyperpolarizes thoracic aorta rings in both C57BL/6 and B1KO mice, with the response unaffected by a B1R antagonist. Interestingly, the absence of B1R alters the LPS response to potassium channels. These activities are independent of nitric oxide synthase (NOS). While exposure to DBK and LPS does not alter B1R and TLR4 mRNA expression, treatment with these agonists increases B1R staining in endothelial cells of thoracic aortic rings and modifies the staining pattern of B1R and TLR4 in endothelial cells. Proximity ligation assay suggests a interaction between the receptors. CONCLUSION: Our findings provide additional support for a putative connection between B1R and TLR4 signaling. Given the involvement of these receptors and their agonists in inflammation, it suggests that drugs and therapies targeting their effects could be promising therapeutic avenues worth exploring.

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.

The effect of ethanol extracts of Loulu flower on LPS-induced acute lung injury in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: In Mongolian medicine, Loulu flower (LLF), the dried inflorescence of Rhaponticum uniflorum (L.) DC. from the Compositae family, has been used to clear heat and relieve toxicity for millennia, particularly in the treatment of pneumonia. AIM OF THIS STUDY: To reveal the effects of LLF on mice with lipopolysaccharide (LPS)-stimulated acute lung injury (ALI) and elucidate the underlying mechanisms. MATERIALS AND METHODS: ALI was established in BALB/c mice via nasal drops administration of LPS (5 mg/kg). The mice were then orally administrated with various doses of LLF extracts and the positive drug dexamethasone (DEX, 5 mg/kg), once daily for seven consecutive days. Last day, after being stimulated with LPS for 6h, the mice were closed dislocation of cervical vertebra, the serum, bronchus alveolar lavage fluid (BALF) and lung tissue were put into the EP tube and stored at -80 °C for further analysis. The changes of histopathology were tested by hematoxylin and eosin stain (H&E), the levels of, IL-1ß, IL-18, TNF-α and IL-4 in BALF and serum were measured by ELISA. The pathways related to the treatment of ALI were predicted by network pharmacology. The expression levels of TLR4/NF-κB and NLRP3 signaling pathway-associated proteins, COX-2 and ERK were tested by western blotting. The levels of P65 and NLRP3 in lung tissues were determined by immunofluorescence analysis. RESULTS: LLF total extract and the extract parts could alleviate the inflammatory cell infiltration, thicken the alveolar walls in lung tissues, reduce the levels of IL-18, IL-1ß in BALF, the TNF-α in both BALF and serum, meantime enhance the level of IL-4 in BALF and serum in mice with LPS-induced ALI. Our network pharmacology and comprehensive gene ontology analyses revealed the active constituents of LLF and the pathways, including TLR4/NF-κB, NLRP3 and MAPK signaling pathways, which play significant roles in ALI. Furthermore, both the total extract and its extraction portions suppressed the expressions of proteins related with the COX-2, p-ERK and TLR4/NF-κB signaling pathway (TLR4, p-IκB, p-p65), as well as the NLRP3 signaling pathway (NLRP3, cleaved caspase-1, caspase-1, IL-1ß). CONCLUSION: LLF could improve the pathological changes and reducing inflammatory reactions in mice induced by LPS. The mechanism may be related to the modulation of the TLR4/NLRP3 signaling pathways.

BECC-engineered live-attenuated Shigella vaccine candidates display reduced endotoxicity with robust immunogenicity in mice.

Shigella spp. infection contributes significantly to the global disease burden, primarily affecting young children in developing countries. Currently, there are no FDA-approved vaccines against Shigella, and the prevalence of antibiotic resistance is increasing, making therapeutic options limited. Live-attenuated vaccine strains WRSs2 (S. sonnei) and WRSf2G12 (S. flexneri 2a) are highly immunogenic, making them promising vaccine candidates, but possess an inflammatory lipid A structure on their lipopolysaccharide (LPS; also known as endotoxin). Here, we utilized bacterial enzymatic combinatorial chemistry (BECC) to ectopically express lipid A modifying enzymes in WRSs2 and WRSf2G12, as well as their respective wild-type strains, generating targeted lipid A modifications across the Shigella backgrounds. Dephosphorylation of lipid A, rather than deacylation, reduced LPS-induced TLR4 signaling in vitro and dampened endotoxic effects in vivo. These BECC-modified vaccine strains retained the phenotypic traits of their parental strains, such as invasion of epithelial cells and immunogenicity in mice without adverse endotoxicity. Overall, our observations suggest that BECC-engineered live attenuated vaccines are a promising approach to safe and effective Shigella vaccines.

The role of HMGB1 on SiC NPs-induced inflammation response in lung epithelial-macrophage co-culture system.

In recent years, carbonized silicon nanoparticles (SiC NPs) have found widespread scientific and engineering applications, raising concerns about potential human health risks. SiC NPs may induce pulmonary damage through sustained inflammatory responses and oxidative stress, with unclear toxicity mechanisms. This study uses an in vitro co-culture model of alveolar macrophages (NR8383) and alveolar epithelial cells (RLE-6TN) to simulate the interaction between airway epithelial cells and immune cells, providing initial insights into SiC NP-triggered inflammatory responses. The research reveals that increasing SiC NP exposure prompts NR8383 cells to release high mobility group box 1 protein (HMGB1), which migrates into RLE-6TN cells and activates the receptor for advanced glycation end-products (RAGE) and Toll-like receptor 4 (TLR4). RAGE and TLR4 synergistically activate the MyD88/NF-κB inflammatory pathway, ultimately inducing inflammatory responses and oxidative stress in RLE-6TN cells, characterized by excessive ROS generation and altered cytokine levels. Pretreatment with RAGE and TLR4 inhibitors attenuates SiC-induced HMGB1 expression and downstream pathway proteins, reducing inflammatory responses and oxidative damage. This highlights the pivotal role of RAGE-TLR4 crosstalk in SiC NP-induced pulmonary inflammation, providing insights into SiC NP cytotoxicity and nanomaterial safety guidelines.

The Role of Natural Products from Herbal Medicine in TLR4 Signaling for Colorectal Cancer Treatment.

The toll-like receptor 4 (TLR4) signaling pathway constitutes an intricate network of protein interactions primarily involved in inflammation and cancer. This pathway triggers intracellular signaling cascades, modulating transcription factors that regulate gene expression related to immunity and malignancy. Previous studies showed that colon cancer patients with low TLR4 expression exhibit extended survival times and the TLR4 signaling pathway holds a significant role in CRC pathogenesis. In recent years, traditional Chinese medicines (TCMs) have garnered substantial attention as an alternative therapeutic modality for CRC, primarily due to their multifaceted composition and ability to target multiple pathways. Emerging evidence indicates that specific TCM products, such as andrographolide, rosmarinic acid, baicalin, etc., have the potential to impede CRC development through the TLR4 signaling pathway. Here, we review the role and biochemical processes of the TLR4 signaling pathway in CRC, and natural products from TCMs affecting the TLR4 pathway. This review sheds light on potential treatment strategies utilizing natural TLR4 inhibitors for CRC, which contributes to the advancement of research and accelerates their clinical integration into CRC treatment.

Puerarin suppresses macrophage M1 polarization to alleviate renal inflammatory injury through antagonizing TLR4/MyD88-mediated NF-κB p65 and JNK/FoxO1 activation.

BACKGROUND: Acute kidney injury (AKI) is a clinically common and serious renal dysfunction, characterized by inflammation and damage to tubular epithelial cells. Puerarin, an isoflavone derivative isolated from Pueraria lobata, has been proven to possess exceptional effectiveness in reducing inflammation. However, the effects and underlying mechanisms of puerarin on AKI remain uncertain. PURPOSE: This study investigated the possible therapeutic effects of puerarin on AKI and explored its underlying mechanism. STUDY DESIGN AND METHODS: The effects of puerarin on AKI and macrophage polarization were investigated in lipopolysaccharide (LPS)-induced or unilateral ureteral obstruction (UUO)-induced mouse models in vivo and LPS-treated macrophages (Raw264.7) in vitro. Additionally, the effects of puerarin on inflammation-related signaling pathways were analyzed. RESULTS: Administration of puerarin effectively alleviated kidney dysfunction and reduced inflammatory response in LPS-induced and UUO-induced AKI. In vitro, puerarin treatment inhibited the polarization of M1 macrophages and the release of inflammatory factors in Raw264.7 cells stimulated by LPS. Mechanistically, puerarin downregulated the activities of NF-κB p65 and JNK/FoxO1 signaling pathways. The application of SRT1460 to activate FoxO1 or anisomycin to activate JNK eliminated puerarin-mediated inhibition of JNK/FoxO1 signaling, leading to suppression of macrophage M1 polarization and reduction of inflammatory factors. Further studies showed that puerarin bound to Toll/interleukin-1 receptor (TIR) domain of MyD88 protein, hindering its binding with TLR4, ultimately resulting in downstream NF-κB p65 and JNK/FoxO1 signaling inactivation. CONCLUSIONS: Puerarin antagonizes NF-κB p65 and JNK/FoxO1 activation via TLR4/MyD88 pathway, thereby suppressing macrophage polarization towards M1 phenotype and alleviating renal inflammatory damage.