TLR4 Expression Research Articles

PSVII-16 Recombinant bovine lactoferrin expressed in Schizochytrium sp. alleviates inflammation and oxidative damage in calf intestinal epithelial cells

Abstract This study aims to generate recombinant bovine lactoferrin (rbLF) by expressing it in Schizochytrium sp. (SZ) and evaluate its effects on calf intestinal epithelial cells (CIECs) exposed to lipopolysaccharide (LPS) or hydrogen peroxide-induced damage. The bovine lactoferrin expression cassette was transfected into Schizochytrium sp. via 18s rRNA gene recombination. Primary CIECs were utilized in this investigation, and the optimal dose of rbLF was evaluated by cell counting kit-8 assay after being treated with different concentrations of rbLF for 24 h. The optimal dose of rbLF was then used as a medium supplement before or after 24 h of 80 μg/mL LPS challenge or 4 h of 400 μM of hydrogen peroxide (H2O2) challenge. Cell viability, gene expression of tumor necrosis factor (TNF) -α, toll-like receptor (TLR) -4, interleukin (IL) -17A, zonula occludens-1 (ZO-1), and claudin-1, as well as protein levels of TNF-α, IL-17A, ZO-1, and claudin-1, were assessed to elucidate the preventive and therapeutic effects of rbLF. Data analysis was performed using SAS 9.4 by F-test, The statistical significance was declared at P < 0.05. Results indicate that rbLF demonstrated no cytotoxicity within the 50 to 1,000 μg/mL range on CIECs. Treatment with 175 μg/mL rbLF for 24 h increased cell viability, expression, and protein concentrations of ZO-1 and claudin following hydrogen peroxide challenge (P < 0.05). Moreover, rbLF pretreatment for 24 hours, despite decreasing cell viability after the H2O2 challenge, increased the expression and protein concentrations of ZO-1 and claudin-1 compared with non-rbLF-treated groups (P < 0.05). When used to prevent LPS-induced inflammation, rbLF enhanced the gene expression and protein concentrations of TNF-α, ZO-1, and claudin-1 compared with controls (P < 0.05). As a treatment for LPS-induced inflammation, rbLF decreased TLR4, TNF-α, and IL-17A expression levels (P < 0.05). These findings suggest that SZ-expressed rbLF is safe for calve intestinal cells and 175 μg/mL of rbLF may mitigate inflammation-induced intestinal barrier dysfunction.

Platycodin D: A promising anti tilapia lake virus natural compound from Platycodon grandiflorus

Tilapia lake virus (TiLV) poses a significant threat to the worldwide tilapia aquaculture sector, and there currently exists no efficient method of containment for this lethal pathogen. Given the widespread utilization of herbal medicines in the treatment of various aquatic animal diseases, it becomes imperative to evaluate and identify herbs that can be used for developing effective drugs against TiLV. We evaluated the efficacy of 20 herbs to inhibit TiLV proliferation in a TiLV infection model (Oreochromis niloticus) through two rounds of screening, with Platycodon grandiflorus extract showing the strongest inhibitory effect on TiLV replication (IC50 = 72.619 mg/L), survival of TiLV-infected tilapia was also improved in individual experiments. Platycodin D (PD), the principal bioactive compound found in Platycodon grandiflorus, demonstrated a dose-dependent reduction in viral load when used for treatment and enhanced the survival rate of tilapia infected with TiLV (42.3 %). The results of serum enzyme activity showed that PD treatment at a concentration of 5 mg/kg significantly enhance the non-specific parameters in tilapia (GSH, ACP, and AKP) (**p < 0.01). Additionally, immune-related gene analysis indicated that PD up-regulated IFN-I, CC2 and other genes expression while down-regulated the expression of pro-inflammatory factors (TNF-α, IL-1β) and TLR2 in the spleen and kidney of tilapia, implying that PD could induce IFN-I expression resulting in potential antiviral effects and inhibit some pro-inflammatory factors to alleviate oxidative stress and inflammatory responses in tilapia. The aforementioned findings suggest that Platycodon grandiflorus could potentially serve as a promising candidate for the development of drugs targeting TiLV. In particular, the bioactive component PD showed a strong anti-TiLV effect, which needs to be further explored.

Unravelling bisphenol A-induced hepatotoxicity: Insights into oxidative stress, inflammation, and energy dysregulation

Bisphenol A (BPA), a prevalent plastic monomer and endocrine disruptor, negatively impacts metabolic functions. This study examines the chronic effects of eco-relevant BPA concentrations on hepatotoxicity, focusing on redox balance, inflammatory response, cellular energy sensors, and metabolic homeostasis in male Swiss albino mice. Chronic BPA exposure resulted in reactive oxygen species (ROS) accumulation, altered hepatic antioxidant defense, lipid peroxidation, and NOX4 expression, leading to reduced cell viability. Additionally, BPA exposure significantly upregulated hepatic pro-inflammatory cytokine genes (Tnf-α, Il-1β, Il-6), NOS2, and arginase II, correlating with increased TLR4 expression, NF-κB phosphorylation, and a dose-dependent decrease in IκBα levels. BPA-induced NF-κB nuclear localization and inflammasome activation (NLRP3, cleaved caspase-1, IL-1β) established an inflammatory milieu. Perturbations in hepatic AMPKα phosphorylation, SIRT1, and PGC-1α, along with elevated p38 MAPK phosphorylation and ERα expression, indicated BPA-induced energy dysregulation. Furthermore, increased PLA2G4A, COX1, COX2, and PTGES2 expression in BPA-treated liver correlated with hyperlipidemia, hepatic FASN expression, steatosis, and visceral adiposity, likely due to disrupted energy sensors, oxidative stress, and inflammasome activation. Elevated liver enzymes (ALP, AST, ALT) and apoptotic markers indicated liver damage. Notably, N-acetylcysteine (NAC) priming reversed BPA-induced hepatocellular ROS accumulation, NF-κB-inflammasome activation, and intracellular lipid accumulation, while upregulating cellular energy sensors and attenuating ERα expression, suggesting NAC's protective effects against BPA-induced hepatotoxicity. Pharmacological inhibition of the NF-κB/NLRP3 cascade in BAY11-7082 pretreated, or NLRP3 immunodepleted hepatocytes reversed BPA's negative impact on SIRT1/p-AMPKα/PGC-1α and intracellular lipid accumulation, providing mechanistic insights into BPA-induced metabolic disruption.

Effect of nystatin on invasion of &lt;i&gt;Serratia grimesii&lt;/i&gt; and &lt;i&gt;Serratia proteamaculans&lt;/i&gt; bacteria into epithelial cells

BACKGROUND: Bacteria use various endocytic pathways during entering non-phagocytic cells. The involvement of caveolae/lipid rafts in bacterial invasion has been demonstrated for many bacterial pathogens. However, for bacteria of the genus Serratia, the involvement of membrane microdomains in the process of bacterial internalization has been poorly studied. AIM: To evaluate the involvement of caveolae/lipid rafts in the invasion of S. grimesii and S. proteamaculans bacteria into non-phagocytic epithelial Caco-2 and M-HeLa cells using nystatin. MATERIALS AND METHODS: M-HeLa and Caco-2 epithelial cells were incubated with 50 μM nystatin for 1 hour at 37 ºC, after which they were infected with the bacteria S. grimesii strain 30063 and S. proteamaculans strain 94, the multiplicity of infection was 100 bacteria per cell. The number of intracellular bacteria was assessed using gentamicin protection assay. The level of caveolin-1 in cells was visualized using confocal microscopy and Western blotting. The expression of Toll-like receptors genes were measured by real-time RT-PCR. RESULTS: Treatment of epithelial cells with nystatin reduces the internalization of S. grimesii and S. proteamaculans into M-HeLa cells by 30% and does not affect penetration into Caco-2 cells. At the same time, nystatin does not affect the redistribution / the integrity impairment of lipid rafts and does not lead to the cytoskeleton reorganization of eukaryotic cells. The addition of nystatin increases the level of caveolin-1 in M-HeLa cells (caveolin-1 is not expressed in Caco-2), which leads to a change plasma membrane fluidity. Nystatin promotes the secretion of proinflammatory cytokines interleukin-6 and interleukin-8 in both cell lines. Infection of M-HeLa cells pretreated with nystatin with the studied bacteria leads to an increase in the expression of tlr2 and tlr4 genes, but does not exceed the level of their expression in control samples. Therefore, it is impossible to speak unambiguously about the participation of Toll-like receptors in the invasion of Serratia bacteria. CONCLUSIONS: The results obtained suggest that the interaction of bacteria with eukaryotic cells induces the expression of caveolin-1, which leads to a change plasma membrane components mobility. This may be due to the fact that β1-integrin is involved in the invasion of the studied bacteria, which should be stabilized at the plasma membrane upon binding of the ligand due to the formation of a cholesterol- and sphingolipid-rich membrane microenvironment.

Viral reprogramming by nervous necrosis virus alters key metabolites and its pathways in sevenband grouper (Hyporthodus septemfasciatus) gills

Nervous necrosis virus (NNV) which mainly infects sevenband grouper (Hyporthodus Septemfasciatus) is considered a potential threat to the grouper aquaculture industry. The gills being one of the portal of entry and an active site of replication of fish viruses emphasises its role as a key region to study the metabolomic changes caused by viral reprograming and hijacking of metabolic pathways associated with immunity of the host. In the present study, liquid chromatography mass spectrometry (LC-MS) was used to detect changes of endogenous compounds of the grouper after NNV infection. A total of 75 metabolites of ten different pathways were identified. The metabolites were mainly associated with fatty acids, lipids, amino acids and nucleotides. The virus reprogramming lead to the downregulation of majority of the metabolites in their pathways. Arachidonic acid (AA), tryptophan, kynurenine and methandriol were selected as representative metabolites and challenge studies with NNV confirmed the fact that, metabolites controlled the replication of virus in a dose dependent manner. Immune gene expression studies also confirmed the effect of metabolites by upregulated expression of interleukins, cytokines and TLRs which are part of cellular immune response. This study shows the viral reprogramming of NNV in grouper gill cells resulting in alterations in basic metabolic pathways associated with normal functioning of the organism.

Minthostachys verticillata essential oil modulates cytokine synthesis and Staphylococcus aureus internalization in MAC-T cells at least through TLR4/MyD88/NFkB pathway.

The aim of this study was to evaluate the activation pathway(s) triggered by Minthostachys verticillata essential oil (EO) in bovine mammary epithelial cells (MAC-T) challenged with a strain of bovine Staphylococcus aureus. MAC-T cells were stimulated with EO, S. aureus or pre-treated with EO and then challenged with S. aureus. Cytokine's release was measured by ELISA. The mRNA for TLR2, TLR4, NOD2, MyD88 and NFκB was quantified by RT-qPCR. S. aureus adherence and internalization was also evaluated. MAC-T cells stimulated with S. aureus synthesized high levels of IL-1ß and IL-6 were kept up to 48 h, while IL-4 levels were not altered.Cells pre-treated with EO for 2 and 6h and then challenged with S. aureus showed a significant increase of IL-1β and IL-6. However, in these cells, a decrease in IL-1ß and IL-6 levels and an increase of IL-4 values was observed from 24 h. No significant increase in the expression levels of TLR2 or NOD2 was detected in all stimulated cells. However, the expression of TLR4, MyD88 and NFκB was increased in cells stimulated with S. aureus at 2 and 6 h as well as in cells pre-treated with EO between 2 and 6h and then challenged with S. aureus. The NFκB expression levels was similar to control at 24h in all stimulated cells, although pro-inflammatory cytokine levels and TLR4 and MyD88 expression levels remained high in cells stimulated with S. aureus. This results suggested the activation of other pathways independent of MyD88 by the pathogen that involucrated the activation of others transcription factors. Pre-treatment with EO during 2, 6 and 24h did not affect S. aureus adherence but decreased its internalization. In conclusion, pre-treatment with EO increased the IL-1β and IL-6 synthesis during the first hours post-challenged with S. aureus up-regulating TLR4/MyD88/NFκB pathway. Furthermore, EO increased the IL-4 levels from 6 to 24 h down-regulating the NFκB and possibly other transcription factors activated by the pathogen, which decreased its internalization into MAC-T cells.

Subgroup Analysis of TLR2, -3, -4 and -8 in Relation to the Severity of Clinical Manifestations of Cervical HPV Infection.

We present the findings of assessing the expression levels of extracellular TLR2 and TLR4 and intracellular TLR3 and TLR8 correlating with the severity of clinical manifestations of HPV infection. A total of 199 women took part in a single-center prospective comparative research study on TLR2, TLR3, TLR4 and TLR8 expression in HPV-related cervical lesions. TLRs' mRNA expression was analyzed using real-time reverse transcription polymerase chain reaction (RT-PCR). Our results indicate the potential significance of TLR3, TLR4 and TLR8 in responding to HPV infection and its progression to SILs and CC, highlighting the importance of HPV polyinfection in relation to TLR4 and TLR8.

Inclusion of sorghum (Sorghum bicolor (L). Moench) with protease and NSP-ase increases jejunal histomorphology and barrier function gene expression in broiler chickens

The objective of this study was to investigate the effect of sorghum with or without protease and NSP-ase on performance, jejunal histomorphology, caecal short-chain fatty acids (SCFA), and gene expression of barrier function in the broiler chickens. A total of 240 males New Lohmann strain MB 202 broiler chicks (1-day-old) were randomly placed into 12 treatments with 4 replications, 5 birds per replicate for 35 d. The diets were a factorial combination of 3 levels of sorghum (0, 10, and 20%), 2 concentrations of protease (with and without protease), and 2 concentrations of NSP-ase (with and without NSP-ase). Results showed that villus height (VH) was improved (P < 0.05) and villus to crypt ratio (VH:CD) tended (P = 0.05) to increase with inclusion of sorghum. Inclusion of sorghum upregulated (P < 0.05) expression of the gene anti-inflammatory IL-13, and downregulated (P < 0.05) gene of toll receptor (TLR) (TLR-3 and TLR-4), pro-inflammatory (IL-18, IL-6, tumor necrosis factor-alpha (TNF-α) and tight junction zona occluding-1 (ZO-1). The result further indicated a decrease (P < 0.05) in the concentration of SCFA. The birds fed diets with protease had lower (P < 0.05) expression of gene TLR-4 and TLR-3, pro-inflammatory (IL-6 and TNF-α), and anti-inflammatory IL-10. Inclusion of sorghum markedly (P < 0.05) interacted with protease, increasing the total of SCFA, acetate, and VH in the broiler. The bird offered diets with NSP-ase had higher (P < 0.05) expression genes of pro-inflammatory IL-18 and TNF-α. Inclusion of sorghum and NSP-ase significantly (P < 0.05) interacted, upregulating gene of tight junction ZO-1 and anti-inflammatory IL-13 but downregulating gene TLR-3, and pro-inflammatory IL-6, while the SCFA production was decreased. Inclusion of sorghum in the diet with or without enzymes did not affect broiler performance (P > 0.05). In conclusion, a diet with sorghum improved jejunal histomorphology without negatively affecting growth performance. Additionally, supplementation with enzymes enhanced intestinal immune responses by up-regulating anti-inflammatory, and downregulating pro-inflammatory gene expression.

Protective Effects of Tea Tree Oil on Inflammatory Injury of Porcine Intestinal Epithelial Cells Induced by Lipopolysaccharide In Vitro.

Tea tree oil (TTO) improves the intestinal mucosal immunity of weaning piglets, but its underlying mechanism is not clear. We hypothesized that TTO may alleviate inflammatory injury by regulating the function of intestinal epithelial cells. Ileum epithelial cells (IPI-2I) were chosen and an inflammatory injury cell model was generated. The cell viability, cytokine secretion, and gene expression of TLR4 and NF-κB were measured to further evaluate the effects of TTO on the inflammatory injury in immune-stressed cells. The results showed that lipopolysaccharide (LPS; content: ≥30 μg/mL; time: 3 h, 6 h, or 9 h) decreased cell viability (p < 0.01), and 50 μg/mL LPS stimulated for 6 h resulted in an increased secretion of proinflammatory cytokines and a dramatically decreased secretion of anti-inflammatory cytokines (p < 0.05) in IPI-2I cells. Concentrations of 0-0.05% of TTO improved cell viability, while the 0.03% TTO treatment resulted in the highest cell viability and alleviated LPS-induced cell death (p < 0.01). In addition, 0.03% TTO alleviated the LPS-induced increase in the gene expression of IL-1β, TNFα, and IFNγ, as well as the decrease in the expression of IL-10 in IPI-2I cells (p < 0.05). LPS also upregulated the gene expression of TLR4 and NF-κB (p < 0.05); while TTO supplementation alleviated this effect (p < 0.05), 0.03% and 0.05% TTO supplementation had greater effects (p < 0.05). In conclusion, 50 μg/mL LPS stimulated for 6 h can be used to establish an immune-stressed cell model in IPI-2I cell lines, and 0.03% TTO treatment for 6 h alleviated inflammatory injury in the intestinal epithelial cells of pigs.

Terminalia bellirica and Andrographis paniculata dietary supplementation in mitigating heat stress-induced behavioral, metabolic and genetic alterations in broiler chickens

BackgroundHeat stress (HS) is one of the most significant environmental stressors on poultry production and welfare worldwide. Identification of innovative and effective solutions is necessary. This study evaluated the effects of phytogenic feed additives (PHY) containing Terminalia bellirica and Andrographis paniculata on behavioral patterns, hematological and biochemical parameters, Oxidative stress biomarkers, and HSP70, I-FABP2, IL10, TLR4, and mTOR genes expression in different organs of broiler chickens under chronic HS conditions. A total of 208 one-day-old Avian-480 broiler chicks were randomly allocated into four treatments (4 replicate/treatment, 52 birds/treatment): Thermoneutral control treatment (TN, fed basal diet); Thermoneutral treatment (TN, fed basal diet + 1 kg/ton feed PHY); Heat stress treatment (HS, fed basal diet); Heat stress treatment (HS, fed basal diet + 1 kg/ton feed PHY).ResultsThe findings of the study indicate that HS led to a decrease in feeding, foraging, walking, and comfort behavior while increasing drinking and resting behavior, also HS increased red, and white blood cells (RBCs and WBCs) counts, and the heterophile/ lymphocyte (H/L) ratio (P < 0.05); while both mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were decreased (P < 0.05). In addition, HS negatively impacted lipid, protein, and glucose levels, liver and kidney function tests, and oxidative biomarkers by increasing malondialdehyde (MDA) levels and decreasing reduced glutathion (GSH) activity (P < 0.05). Heat stress (HS) caused the upregulation in HSP70, duodenal TLR4 gene expression, and the downregulation of I-FABP2, IL10, mTOR in all investigated tissues, and hepatic TLR4 (P < 0.05) compared with the TN treatment. Phytogenic feed additives (PHY) effectively mitigated heat stress’s negative impacts on broilers via an improvement of broilers’ behavior, hematological, biochemical, and oxidative stress biomarkers with a marked decrease in HSP70 expression levels while all tissues showed increased I-FABP2, IL10, TLR4, and mTOR (except liver) levels (P < 0.05).ConclusionPhytogenic feed additives (PHY) containing Terminalia bellirica and Andrographis paniculata have ameliorated the HS-induced oxidative stress and improved the immunity as well as the gut health and welfare of broiler chickens.

Vibriocidal efficacy of Bifidobacterium bifidum and Lactobacillus acidophilus cell-free supernatants encapsulated in chitosan nanoparticles against multi-drug resistant Vibrio cholerae O1 El Tor

BackgroundCholera is a diarrheal disease recognized for being caused by toxin-producing Vibrio (V.) cholerae. This study aims to assess the vibriocidal and immunomodulatory properties of derived cell-free supernatants (CFSs) of Bifidobacterium (B.) bifidum and Lactobacillus (L.) acidophilus encapsulated in chitosan nanoparticles (CFSb-CsNPs and CFSa-CsNPs) against clinical multi-drug resistance (MDR) isolates of V. cholerae O1 El Tor.MethodsWe synthesized CFSb-CsNPs and CFSa-CsNPs using the ionic gelation technique. The newly nanostructures were characterized for size, surface zeta potential, morphology, encapsulation efficacy (EE), stability in different pH values and temperatures, release profile, and in vitro cytotoxicity. The antimicrobial and antibiofilm effects of the obtained nanocomposites on clinical MDR isolates (N = 5) of V. cholerae E1 Tor O1 were investigated by microbroth dilution assay and crystal violet staining, respectively. We conducted quantitative real-time PCR (qRT-PCR) to analyze the relative gene expressions of Bap, Rbmc, CTXAB, and TCP in response to CFSb-CsNPs and CFSa-CsNPs. Additionally, the immunomodulatory effects of formulated structures on the expression of TLR2 and TLR4 genes in human colorectal adenocarcinoma cells (Caco-2) were studied.ResultsNano-characterization analyses indicated that CFSb-CsNPs and CFSa-CsNPs exhibit spherical shapes under scanning electron microscopy (SEM) imaging, with mean diameters of 98.16 ± 0.763 nm and 83.90 ± 0.854 nm, respectively. Both types of nanoparticles possess positive surface charges. The EE% of CFSb-CsNPs was 77 ± 4.28%, whereas that of CFSa-CsNPs was 62.5 ± 7.33%. Chitosan (Cs) encapsulation leads to increased stability of CFSs in simulated pH conditions of the gastrointestinal tract in which the release rates for CFSb-CsNPs and CFSa-CsNPs were reached at 58.00 ± 1.24% and 55.01 ± 1.73%, respectively at pH = 7.4. The synergistic vibriocidal effects observed from the co-administration of both CFSb-CsNPs and CFSa-CsNPs, as evidenced by a fractional inhibitory concentration (FIC) index of 0.57, resulting in a significantly lower MIC of 2.5 ± 0.05 mg/mL (p < 0.0001) compare to individual administration. The combined antibacterial effect of CFSb-CsNPs and CFSa-CsNPs on Bap (0.14 ± 0.05), Rbmc (0.24 ± 0.01), CTXAB (0.30 ± 0.09), and TCP (0.38 ± 0.01) gene expression was significant (p < 0.001). Furthermore, co-administration of CFSb-CsNPs and CFSa-CsNPs also demonstrated the potency of suppressing TLR 2/4 (0.20 ± 0.01 and 0.12 ± 0.02, respectively) gene expression (p = 0.0019) and reduced Caco-2 cells attached bacteria to 526,000 ± 51,46 colony-forming units/mL (11.19%) (p < 0.0001).ConclusionOur study revealed that encapsulating CFSs within CsNPs enhances their vibriocidal activity by improving stability and enabling a controlled release mechanism at the site of interaction between the host and bacteria. Additionally, the simultaneous use of CFSb-CsNPs and CFSa-CsNPs exhibited superior vibriocidal potency against MDR V. cholerae O1 El Tor strains, indicating these combinations as a potential new approach against MDR bacteria.

Multifunctional natamycin modified chondroitin sulfate eye drops with anti-inflammatory, antifungal and tissue repair functions possess therapeutic effects on fungal keratitis in mice.

Fungal keratitis (FK) is recognized as a stubborn ocular condition, caused by intense fungal invasiveness and heightened immune reaction. The glycosaminoglycan chondroitin sulfate exhibits properties of immunomodulation and tissue regeneration. In prior investigations, oxidized chondroitin sulfate (OCS) ameliorated the prognosis of FK in murine models. To further improve the curative efficacy, we used the antifungal drug natamycin to functionalize OCS and prepared oxidized chondroitin sulfate-natamycin (ON) eye drops. The structure of ON was characterized by FTIR, UV–vis, and XPS, revealing that the amino group of natamycin combined with the aldehyde group in OCS through Schiff base reaction. Antifungal experiments revealed that ON inhibited fungal growth and disrupted the mycelium structure. ON exhibited exceptional biocompatibility and promoted the proliferation of corneal epithelial cells. Pharmacokinetic analysis indicated that ON enhanced drug utilization by extending the mean residence time in tears. In murine FK, ON treatment reduced the clinical score and corneal fungal load, restored corneal stroma conformation, and facilitated epithelial repair. ON effectively inhibited neutrophil infiltration and decreased the expression of TLR-4, LOX-1, IL-1β, and TNF-α. Our research demonstrated that ON eye drops achieved multifunctional treatment for FK, including inhibiting fungal growth, promoting corneal repair, enhancing drug bioavailability, and controlling inflammatory reactions.

TLR10 (CD290) Is a Regulator of Immune Responses in Human Plasmacytoid Dendritic Cells.

TLRs are the most thoroughly studied group of pattern-recognition receptors that play a central role in innate immunity. Among them, TLR10 (CD290) remains the only TLR family member without a known ligand and clearly defined functions. One major impediment to studying TLR10 is its absence in mice. A recent study on TLR10 knock-in mice demonstrated its intrinsic inhibitory role in B cells, indicating that TLR10 is a potential drug target in autoimmune diseases. In this study, we interrogated the expression and function of TLR10 in human plasmacytoid dendritic cells (pDCs). We have seen that primary human pDCs, B cells, and monocytes constitutively express TLR10. Upon preincubation with an anti-TLR10 Ab, production of cytokines in pDCs was downregulated in response to stimulation with DNA and RNA viruses. Upon further investigation into the possible mechanism, we documented phosphorylation of STAT3 upon Ab-mediated engagement of TLR10. This leads to the induction of inhibitory molecule suppressor of cytokine signaling 3 (SOCS3) expression. We have also documented the inhibition of nuclear translocation of transcription factor IFN regulatory factor 7 (IRF7) in pDCs following TLR10 engagement. Our data provide the (to our knowledge) first evidence that TLR10 is constitutively expressed on the surface of human pDCs and works as a regulator of their innate response. Our findings indicate the potential of harnessing the function of pDCs by Ab-mediated targeting of TLR10 that may open a new therapeutic avenue for autoimmune disorders.

Proanthocyanidins alleviate Henoch-Schönlein purpura by mitigating inflammation and oxidative stress through regulation of the TLR4/MyD88/NF-κB pathway.

Investigate Proanthocyanidins (PCs) efficacy and mechanisms in treating Henoch-Schönlein purpura (HSP)-like rat models, focusing on inflammatory and oxidative stress (OS) responses. An HSP-like rat model was established using ovalbumin (OVA) injection, leading to symptoms mimicking HSP. The study measured inflammatory markers (IL-4, IL-17, TNF-α), OS markers (MDA, SOD, CAT), and assessed the TLR4/MyD88/NF-κB signaling pathway's involvement via histopathological and immunofluorescence analyses. PCs treatment significantly improved HSP-like symptoms, reduced inflammatory cell infiltration, and decreased IgA deposition in renal mesangial areas. Serum analyses revealed that PCs effectively lowered IL-4, IL-17, TNF-α, and MDA levels while increasing SOD and CAT levels (p<0.05). Crucially, PCs also downregulated TLR4, MyD88, and NF-κB expressions, highlighting the blockage of the TLR4-mediated signaling pathway as a key mechanism. PCs show promising therapeutic effects in HSP-like rats by mitigating inflammatory responses and oxidative damage, primarily through inhibiting the TLR4/MyD88/NF-κB pathway. These findings suggest PCs as a potential treatment avenue for HSP, warranting further investigation.

Anti-inflammatory Effect of Novel 2-Phenylphthalazin-2-ium Bromides on LPS-induced RAW264.7 Cells and their Mechanism

Background: Inspired by natural anti-inflammatory quaternary benzo[C]phenanthridine alkaloids, novel 2-phenylphthalazin-2-ium bromides were previously designed and synthesized. Objective: The anti-inflammatory effect of 2-phenylphthalazin-2-ium bromides was evaluated based on inflammatory cytokines, and their possible mechanism was explored through the NF-κB, TLR4 and MAPK signaling pathways. Methods: The tested concentrations of two compounds were assessed using MTT assay in vitro. Griess assay was used to determine the changes in nitric oxide (NO) in the cell culture supernatant. qRT‒PCR was used to detect the mRNA levels of inflammatory cytokines, such as IL-6, IL-1ß, IL-10, TNF-α, TLR4 and iNOS. The secretion levels of TNF-α and IL-1β were detected by ELISA. Western blot test was used to detect the protein expression of IL-6, IL-10, TLR4, iNOS, NF-κB, p-P38/P38, p- ERK/ERK and p-JNK/JNK. Results: 2-(3,5-Dichlorophenyl)phthalazin-2-ium bromide (2) with a concentration below 1 μg/mL showed no significant effect on the growth inhibition of RAW264.7 cells, so the concentrations of compound 2 used for experiments were set to 0, 0.25, 0.5 and 1 μg/mL. Compared with the blank control group, the model group showed increased release of NO, transcription levels of IL-6, IL-1ß, IL-10, TNF-α, TLR4 and iNOS (p&lt; 0.05), and ratios of p-P38/P38, p-ERK/ERK, p-JNK/JNK (p&lt; 0.05). Compared with the model group, the sample groups displayed decreased NO release and reduced transcriptional levels of IL-6, IL-1ß, IL-10, TNF-α, TLR4, and iNOS and reduced protein expression ratios of IL-6, IL-1ß, IL-10, TNF-α, NF-κB, TLR4, iNOS, p-P38/P38, p-ERK/ERK and p- JNK/JNK (p&lt; 0.05). Conclusion: This study showed that 2-phenylphthalazin-2-ium bromides partially protected macrophages from the LPS-induced inflammatory response by suppressing TLR4-NF-κB/MAPK signaling and reducing NO production.

Human inborn errors of long-chain fatty acid oxidation show impaired inflammatory responses to TLR4-ligand LPS.

Stimulation of mammalian cells with inflammatory inducers such as lipopolysaccharide (LPS) leads to alterations in activity of central cellular metabolic pathways. Interestingly, these metabolic changes seem to be important for subsequent release of pro-inflammatory cytokines. This has become particularly clear for enzymes of tricarboxylic acid (TCA) cycle such as succinate dehydrogenase (SDH). LPS leads to inhibition of SDH activity and accumulation of succinate to enhance the LPS-induced formation of IL-1β. If enzymes involved in beta-oxidation of fatty acids are important for sufficient responses to LPS is currently not clear. Using cells from various patients with inborn long-chain fatty acid oxidation disorders (lcFAOD), we report that disease-causing deleterious variants of Electron Transfer Flavoprotein Dehydrogenase (ETFDH) and of Very Long Chain Acyl-CoA Dehydrogenase (ACADVL), both cause insufficient inflammatory responses to stimulation with LPS. The insufficiencies included reduced TLR4 expression levels, impaired TLR4 signaling, and reduced or absent induction of pro-inflammatory cytokines such as IL-6. The insufficient responses to LPS were reproduced in cells from healthy controls by targeted loss-of-function of either ETFDH or ACADVL, supporting that the deleterious ETFDH and ACADVL variants cause the attenuated responses to LPS. ETFDH and ACADVL encode two distinct enzymes both involved in fatty acid beta-oxidation, and patients with these deficiencies cannot sufficiently metabolize long-chain fatty acids. We report that genes important for beta-oxidation of long-chain fatty acids are also important for inflammatory responses to an acute immunogen trigger like LPS, which may have important implications for understanding infection and other metabolic stress induced disease pathology in lcFAODs.

HIV1 gp120 activates microglia via TLR2-NF-κB signaling to up-regulate inflammatory cytokine expression and induce neuropathic pain

HIV associated neuropathic pain (HANP) is a common complication of AIDS. Intrathecal injection of recombinant HIV-1 gp120 in mice is a well-known model. Previous RNA sequencing revealed spinal TLR2 acts as a differentially expressed gene in HANP mice. The spinal TLR2 is involved in HANP, but its role and underlying mechanism remains unclear. In this study the transcription, expression and distribution characteristics of TLR2 in the spinal cord of HANP male mice have been analyzed by qRT-PCR, Western blotting, and immunofluorescent staining. We found that TLR2 expression was upregulated in the spinal dorsal horn and mainly distributed in microglial cells, and blocking TLR2 relieved pain of HANP mice. Following stimulation by gp120 microglial cells upregulate TLR2 expression and become activated. The activation stimulates their differentiation into the M1 type, increasing IL-1β and TNF-α expression while inhibiting IL-10 expression. Silencing the Tlr2 gene slows down the activation, polarization, and secretion of pro-inflammatory factors in microglial cells induced by gp120, and enhances the expression of anti-inflammatory factors. Further analysis of the impact of gp120 on downstream signaling pathways of TLR2 in microglial cells, including NF-κB, MAPK (p38MAPK, ERK, and JNK) and PI3K/AKT, revealed that TLR2-NF-κB signaling plays a crucial role in the activation and polarization of microglial cells by gp120. Activation of NF-κB signaling aggravates pain in HANP mice, while blocking it lightens pain. This data indicates that gp120, through the TLR2-NF-κB signaling, activates spinal microglial cells, promotes the secretion of inflammatory cytokines, leading to HANP. This provides new targets to develop drugs for HANP.

TYROBP serve as potential immune-related signature genes in the acute phase of intracerebral hemorrhage

The development of intracerebral hemorrhage (ICH) is a dynamic process and intervention during the acute phase of ICH is critical for subsequent recovery. Therefore, it is crucial to screen potential signature genes and therapeutic target genes in the acute phase of ICH. In this study, based on the results of mRNA sequencing in mouse ICH and mRNA sequencing of human ICH from online databases, top five potential signature genes after ICH, Tyrobp, Itgb2, Tlr2, Ptprc and Itgam, were screened. Quantitative PCR results showed higher mRNA expression of Tyrobp, Itgb2, Tlr2, Ptprc, and Itgam in the 1-, 3- and 5-day mouse ICH groups compared to the sham-operated group. Immune infiltration correlation analysis shows that the top-ranked signature gene, Tyrobp, is negatively correlated with M2 macrophages and plasma cells, and Western blot analysis shows higher expression of the Tyrobp protein in the 1-, 3-, and 5-day mouse ICH groups compared to the sham-operated group. Furthermore, immunohistochemistry revealed that TYROBP protein expression was significantly higher in human ICH tissues than in normal brain tissues. Our results suggest that Tyrobp is a signature gene in the acute phase of ICH and may be a potential target for the treatment of the acute phase of ICH.

Dihydromyricetin Nanoparticles Alleviate Lipopolysaccharide-Induced Acute Kidney Injury by Decreasing Inflammation and Cell Apoptosis via the TLR4/NF-κB Pathway.

Acute kidney injury (AKI) is the most severe and fatal complication of sepsis resulting from infectious trauma. Currently, effective treatment options are still lacking. Dihydromyricetin is the main component extracted from Vine tea (Ampelopsis megalophylla Diels et Gilg). In our previous research, chitosan-tripolyphosphate-encapsulated nanoparticles of dihydromyricetin (CS-DMY-NPs) have been proven to have potential protective effects against cisplatin-induced AKI. Here, we investigated the protective effects and mechanisms of DMY and its nano-formulations against LPS-induced AKI by assessing pathological and inflammatory changes in mice. In mice with LPS-AKI treated with 300 mg/kg CS-DMY-NPs, the levels of creatinine (Cr), blood urea nitrogen (BUN), and KIM-1 were significantly reduced by 56%, 49%, and 88%, respectively. CS-DMY-NPs can upregulate the levels of GSH, SOD, and CAT by 47%, 7%, and 14%, respectively, to inhibit LPS-induced oxidative stress. Moreover, CS-DMY-NPs decreased the levels of IL-6, IL-1β, and MCP-1 by 31%, 49%, and 35%, respectively, to alleviate the inflammatory response. TUNEL and immunohistochemistry showed that CS-DMY-NPs reduced the number of apoptotic cells, increased the Bcl-2/Bax ratio by 30%, and attenuated renal cell apoptosis. Western blot analysis of renal tissue indicated that CS-DMY-NPs inhibited TLR4 expression and downregulated the phosphorylation of NF-κB p65 and IκBα. In summary, DMY prevented LPS-induced AKI by increasing antioxidant capacity, reducing inflammatory responses, and blocking apoptosis, and DMY nanoparticles were shown to have a better protective effect for future applications.

Protective effect of Acanthus ilicifolius extracts against acute alcoholic liver injury via suppressing TLR4/NF-κB signal pathway and modulating intestinal microbiota in mice

Excessive alcohol consumption is leading to increased rates of liver injury and disease. A new research strategy focuses on manipulating gut microbiota to lessen alcohol-induced harm. This study examined the hepatoprotective effects of extracts from Acanthus ilicifolius (EAI) on acute alcoholic liver injury by inhibiting the TLR4/NF-κB signalling pathway and modulating intestinal microbiota in mice. The results showed that EAI dose-dependently reduced alcohol-induced elevations of AST, ALT, and ALP levels. EAI showed significant inhibitory effects on the expressions of TLR4, NF-κB, and pNF-κB proteins. Furthermore, EAI caused a notable reduction in hepatic levels of IL-1β, IL-6, and TNF-α. Supplementation with EAI could ameliorate alcohol-induced dysbiosis of intestinal bacteria. The levels of ALT, AST, and ALP levels were negatively correlated with Ligilactobacillus, Lactobacillus, and Alistipes, but positively correlated with Helicobacter and Bacteroides. Overall, EAI alleviated alcoholic liver injury in mice by inhibiting the TLR4/NF-κB signalling pathway and modulating intestinal bacteria.