Lipopolysaccharide-induced Inflammatory Responses Research Articles

Alginate Oligosaccharide Alleviates Lipopolysaccharide-Induced Apoptosis and Inflammatory Response of Rumen Epithelial Cells through NF-κB Signaling Pathway.

AOS alleviates inflammatory responses; however, whether it exerts an effect on the rumen or regulates rumen inflammatory reaction remains unknown. In this study, firstly, the ovine ruminal epithelial cells (ORECs) were treated with 0, 200, 400, 600, and 800 µg/mL AOS, hoping to explore whether AOS hurt cell health. The results showed that compared with the AOS-0 group, the AOS-400 group could significantly increase (p < 0.05) cell viability, reduce (p < 0.05) reactive oxygen species (ROS) and interleukin (IL)-6 content, and have no adverse effect on cells. Secondly, we used LPS to construct an in vitro inflammatory model of rumen epithelial cells and then explored the protective role of AOS on rumen epithelial cells. The study was divided into three groups: the control group (CON), LPS, and LPS + AOS. The results demonstrated that the LPS + AOS group significantly increased the cell viability and reduced the ROS level in comparison with the LPS group (p < 0.05). Pretreatment with AOS also repressed (p < 0.05) the secretion of IL-1β, IL-6, IL-8, and immunoglobulin (Ig)A from ORECs in the culture medium following LPS. In terms of tight junction (TJ) proteins, AOS treatment also significantly increased (p < 0.05) the zonula occludens 1 (ZO-1) and Occludin expression. The apoptosis rate, Caspase3, Caspase9, BAD, and BCL-2/BAX were decreased (p < 0.05) after AOS treatment, and the expression of BCL-2 was increased (p < 0.05). In addition, the expressions of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) were inhibited (p < 0.05) with the addition of AOS. At the protein level, pretreatment of AOS decreased (p < 0.05) the expression of MyD88 and the phosphorylation level of inhibitor κB α (IκBα) after the LPS challenge. Taken together, our results indicated that AOS could alleviate the LPS-induced apoptosis and inflammatory response of rumen epithelial cells through the NF-κB signaling pathway, which may be a promising strategy for treating apoptosis and inflammation in sheep breeding.

Exploring the chemical diversity of sesquiterpenes from the rarely studied south China sea soft coral Sinularia tumulosa assisted by molecular networking strategy

Molecular networking strategy-based prioritization of the isolation of the rarely studied soft coral Sinularia tumulosa yielded 14 sesquiterpenes. These isolated constituents consisted of nine different types of carbon frameworks, namely asteriscane, humulane, capillosane, seco-asteriscane, guaiane, dumortane, cadinane, farnesane, and benzofarnesane. Among them, situmulosaols A–C (1, 3 and 4) were previously undescribed ones, whose structures with absolute configurations were established by the combination of extensive spectral data analyses, quantum mechanical-nuclear magnetic resonance and time-dependent density functional theory electronic circular dichroism calculations, the Snatzke's method, and the modified Mosher's method. Notably, situmulosaol C (4) was the second member of capillosane-type sesquiterpenes. The plausible biogenetic relationships of these skeletally different sesquiterpenes were proposed. All sesquiterpenoids were evaluated for their antibacterial, cytotoxic and anti-inflammatory effects. The bioassay results showed compound 14 exhibited significant antibacterial activities against a variety of fish and human pathogenic bacteria with MIC90 values ranging from 3.6 to 33.8 μg/mL. Moreover, moderate cytotoxic effects against HEL cells for components 13 and 14 and moderate inhibitory effect on lipopolysaccharide-induced inflammatory responses in RAW264.7 cells for substance 13 were also observed.

Inhibitory effect of downregulating G protein-coupled receptor class C group 5 member A expression on lipopolysaccharide-induced inflammatory response in human gingival fibroblasts

Objective: To clarify the effect and the mechanism of G protein-coupled receptor class C group 5 member A (GPRC5A) on lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (GFs), thus to provide a foundation for delving into the role of G protein coupled receptor (GPCR) in periodontitis. Methods: Gingival tissue samples were collected from 3 individuals periodontally healthy (health group) and 3 patients with periodontitis (periodontitis group) in Shandong Stomatological Hospital from December 2022 to February 2023. The expressions of GPRC5A of the two groups were detected by immunohistochemistry staining. GFs used in this study were isolated from a portion of gingiva for the extraction of impacted teeth in School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University from December 2022 to February 2023. GFs were isolated with enzymic digestion and transfected with 30, 50 and 80 μmol/L small interfering RNA-GPRC5A (siGPRC5A) or small interfering RNA-negative control (siNC), regarded as the experimental group and the negative control one, respectively. The silencing efficiency of siGPRC5A was evaluated by real-time fluorescence quantitative PCR (RT-qPCR). Experiments were then conducted using these cells which were divided into four groups of negative control (NC), LPS, siGPRC5A+LPS and siGPRC5A. The mRNA and protein levels of GPRC5A in GFs under 1 mg/L LPS-induced GFs inflammatory state were evaluated by RT-qPCR and Western blotting analysis after GPRC5A knockdown. RT-qPCR was used to detect the gene expression levels of the inflammatory cytokines in GFs induced by LPS, namely, interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, prostaglandin endoperoxide synthase 2 (PTGS2) after GPRC5A knockdown. Western blotting analysis and immunofluorescence staining were used to further investigate the activation of nuclear factor-kappa B (NF-κB) signaling pathway. Results: Immunohistochemistry staining showed that the expression of GPRC5A in gingival tissues of periodontitis group (0.132±0.006) increased compared with that in periodontally healthy group (0.036±0.019) (t=8.24, P=0.001). Meanwhile, RT-qPCR results showed that the gene expression levels of GPRC5A at different time point (2, 6, 12, 24 h) in LPS-induced GFs (0.026±0.002, 0.042±0.005, 0.004±0.000, 0.016±0.000) were upregulated compared with those in the NC group (0.004±0.000, 0.004±0.000, 0.002±0.000, 0.007±0.000) (all P<0.001), respectively, and peaked at 6 h. The 50 μmol/L group displayed the most significant decrease in siGPRC5A expression (31.16±3.29) compared with that of the siNC group (100.00±4.88) (F=297.98, P<0.001). The results of RT-qPCR and Western blotting analysis showed that siGPRC5A (0.27±0.03, 0.71±0.00) suppressed the expressions of GPRC5A at both gene and protein levels, while LPS (1.30±0.10, 1.43±0.03) was able to promote the expressions of GPRC5A compared with those of the NC group (1.00±0.01, 1.00±0.00)(all P<0.001). The siGPRC5A+LPS group (0.39±0.03, 1.06±0.16) also inhibited the increase of GPRC5A at both gene and protein levels induced by LPS (1.30±0.10, 1.43±0.03) (F=208.38, P<0.001; F=42.04, P<0.001). RT-qPCR results showed that the expressions of IL-8, IL-1β, IL-6, TNF-α, and PTGS2 at the gene level in LPS group were highly increased compared with those in the NC group (all P<0.001). siGPRC5A significantly suppressed LPS-induced expressions of these inflammatory cytokines in GFs (all P<0.001). Western blotting analysis showed that the levels of p65 and IκBα protein phosphorylation in the LPS group were highly increased compared with those in the NC group, and siGPRC5A could effectively suppressed LPS-induced protein phosphorylation (all P<0.01). Furthermore, immunofluorescence staining showed that NF-κB p65 in the control group was mainly concentrated in the cytoplasm, and partially translocated to the nucleus under the stimulation of LPS. siGPRC5A was able to inhibit LPS-induced intranuclear translocation of p65 to a certain extent. Conclusions: GPRC5A expression was upregulated in periodontitis, and GPRC5A knockdown inhibited LPS-induced inflammation. Moreover, GPRC5A played a role in inflammation regulation by interacting with NF-κB signaling pathway.

Design and evaluation of nanostructured lipid carrier of Bergenin isolated from Pentaclethra macrophylla for anti-inflammatory effect on lipopolysaccharide-induced inflammatory responses in macrophages

Herein, we report the properties of nanostructured lipid carriers (NLCs) prepared with a gradient concentration of Bergenin (BGN) isolated from Pentaclethra macrophylla stem bark powder. A gradient concentration of BGN (BGN 0, 50, 100, 150, and 200 mg) was prepared in a 5 % lipid matrix consisting of Transcutol HP (75 %), Phospholipon 90H (15 %), and Gelucire 43/01 (10 %) to which a surfactant aqueous phase consisting of Tween 80, sorbitol, and sorbic acid was dissolved. The NLCs were evaluated by size, polydispersity index (PDI), zeta potential, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), encapsulation efficiency, and in vitro drug release. The result shows polydispersed nanoparticles with high drug encapsulation (94.26–99.50 %). The nanoparticles were mostly spherical, but those from the 50 mg BGN batch were more cuboidal than spherical. The drug release was highest from the latter to the tune of 40 % compared to the pure BGN solution, which released about 15 % BGN. The anti-inflammatory activity of the BGN-NLC and total plant extract was studied on lipopolysaccharide (LPS)-inflamed macrophages. The cell study showed that BGN and plant extract had low cytotoxicity on macrophages and exhibited a dose-dependent anti-inflammatory effect on the LPS-induced inflammatory process in macrophages.

The accessible chromatin landscape of lipopolysaccharide-induced systemic inflammatory response identifying epigenome signatures and transcription regulatory networks in chickens

Lipopolysaccharide (LPS) can induce systemic inflammatory response (SIR) in animals. Understanding the regulatory mechanism of SIR and therapies to ensure healthy growth is urgently needed. Chromatin remodeling plays a crucial role in the expression of genes involved in immune diseases. In the present study, the ATAC-seq analysis revealed 3491 differential open chromatin sites in the spleen of chicks with SIR induced by LPS challenge, and we presented the motifs on these sites and the associated transcription factors. The regulatory network was presented by combining the differential open chromatin data with the mRNAs and exploded cytokines. Interestingly, the LPS challenge could regulate the mRNA expression of 202 genes through chromatin reprogramming, including critical genes such as TLE1 and JUN, which regulate signaling pathways such as I-κB kinase/NF-κB, Toll-like receptor, and downstream cytokine genes. Furthermore, dietary daidzein could inhibit DNA topoisomerase II, which reprograms the spatial conformation of chromatin in the inflammatory response and attenuates SIR. In conclusion, we successfully identified key genes directly regulated by chromatin reprogramming in SIR and demonstrated the chromatin epigenome signatures and transcriptional regulatory network, which provides an important reference for further research on avian epigenetics. There is great potential for alleviating SIR using dietary daidzein.

Gentiopicroside ameliorates the lipopolysaccharide-induced inflammatory response and hypertrophy in chondrocytes

PurposeThis study aimed to evaluate the protective effects of gentiopicroside against lipopolysaccharide-induced chondrocyte inflammation.MethodsSW 1353 chondrosarcoma cells were stimulated with LPS (5 μg/ml) for 24 h and treated with different concentrations of gentiopicroside (GPS) for 24 h. The toxic effects of GPS on chondrocytes were determined using a CCK-8 assay and EdU staining. Western blotting, qPCR, and immunofluorescence analysis were used to examine the protective effect of GPS against the inflammatory response in chondrocytes induced by lipopolysaccharide (LPS). One-way ANOVA was used to compare the differences between the groups (significance level of 0.05).ResultsThe CCK-8 results showed that 10, 20 and 40 μM GPS had no significant toxic effects on chondrocytes; GPS effectively reduced the production of IL-1β and PGE2, reversed LPS-induced extracellular matrix degradation in cartilage by inhibiting the Stat3/Runx2 signaling pathway, and suppressed the hypertrophic transformation of SW 1353 chondrosarcoma cells.ConclusionOur study demonstrated that GPS significantly inhibited the LPS-induced inflammatory response and hypertrophic cellular degeneration in SW 1353 chondrosarcoma cells and is a valuable traditional Chinese medicine for the treatment of knee osteoarthritis.

Effect of n-Hexane Extract from Tanacetum argenteum (Lam.) Willd. subsp. argenteum on the Secretion of Proinflammatory Cytokines in THP-1 Cell Line

Inflammation is an initial biological process that involves the activation of the immune system in response to injury, infection or exposure to toxic agents. During this process, cytokines, small proteins produced by immune cells, play a vital role in regulating the immune response. Inflammatory cytokines, including interleukins, tumor necrosis factor-α, nitric oxide, and interferon-gamma, initiate the immune response and promote inflammation. Natural products are frequently a source of potential anti-inflammatory compounds, and screening natural products can lead to the discovery of novel bioactive compounds. The present study aimed to investigate the effects of n-hexane extract from Tanacetum argenteum subsp. argenteum on the lipopolysaccharide-induced inflammatory response in human macrophages THP-1 cell. Cells were incubated with different concentrations of n-hexane extract, and the inhibitor effects of the extract exposure on various cytokine secretions were determined. The findings demonstrated that n-hexane extract dramatically decreased the levels of interleukin‑6, interleukin‑1β, and tumor necrosis factor‑α in differentiated THP-1 cells, indicating the remarkable anti-inflammatory potential of the extract. Furthermore, in silico analysis of toxicogenomic data revealed the interactions between the active component of the n-hexane extract and interleukin-6, interleukin-1β, and tumor necrosis factor.

Dihydropashanone Isolated from Lindera erythrocarpa, a Potential Natural Product for the Treatment of Neurodegenerative Diseases.

Lindera erythrocarpa, a flowering plant native to eastern Asia, has been reported to have neuroprotective activity. However, reports on the specific bioactive compounds in L. erythrocarpa are finite. The aim of this study was to investigate the anti-neuroinflammatory and neuroprotective effects of the compounds isolated from L. erythrocarpa. Dihydropashanone, a compound isolated from L. erythrocarpa extract, was found to have protected mouse hippocampus HT22 cells from glutamate-induced cell death. The antioxidant and anti-inflammatory properties of dihydropashanone in mouse microglial BV2 and HT22 cells were explored in this study. The results reveal that dihydropashanone inhibits lipopolysaccharide-induced inflammatory response and suppresses the activation of nuclear factor (NF)-κB in BV2 cells. In addition, dihydropashanone reduced the buildup of reactive oxygen species in HT22 cells and induced activation of the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase (HO)-1 signaling pathway in BV2 and HT22 cells. Our results suggest that dihydropashanone reduces neuroinflammation by decreasing NF-κB activation in microglia cells and protects neurons from oxidative stress via the activation of the Nrf2/HO-1 pathway. Thus, our data suggest that dihydropashanone offers a broad range of applications in the treatment of neurodegenerative illnesses.

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

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

Astrocyte-Derived Exosomal miR-148a-3p Suppresses Neuroinflammation and Restores Neurological Function in Traumatic Brain Injury by Regulating the Microglial Phenotype.

Interactions between astrocytes and microglia play an important role in the regeneration and repair of traumatic brain injury (TBI), and exosomes are involved in cell-cell interactions. A TBI model was constructed in rats. Brain extract (Ext) was isolated 1 d after TBI. Astrocyte-derived exosomes were obtained by coculturing Ext with primary astrocytes, and the morphology of exosomes was observed by electron microscopy. The isolated exosomes were cocultured with microglia to observe phenotypic changes in M1 and M2 markers. Aberrant RNA expression was detected in necrotic brain tissue and edematous brain tissue. The role of miR-148a-3p in regulating microglial phenotype was explored by knocking down or overexpressing miR-148a-3p. Finally, the effect of miR-148a-3p on TBI was studied in a rat TBI model. Astrocyte-derived exosomes stimulated by Ext promoted the transition of microglia from the M1 phenotype to the M2 phenotype. MiR-148a-3p was highly expressed in TBI. Transfecting miR-148a-3p promoted the transition of microglia from the M1 phenotype to the M2 phenotype and inhibited the lipopolysaccharide-induced inflammatory response in pre-microglia. In a rat TBI model, miR-148a-3p significantly improved the modified neurological severity score and attenuated brain injury, which promoted the transition of microglia from the M1 phenotype to the M2 phenotype. MiR-148a-3p alleviated TBI by inhibiting the nuclear factor κB pathway. Astrocyte-derived exosomal miR-148a-3p regulates the microglial phenotype, inhibits neuroinflammation, and restores neurological function in TBI. These results provide new potential targets for the treatment of TBI.

Maternal quercetin supplementation improved lipopolysaccharide-induced cognitive deficits and inflammatory response in a rat model of maternal immune activation

BackgroundThere is strong evidence that prenatal infection during a specific period of brain development increases the risk of neurodevelopmental disorders, partly through immune-inflammatory pathways. This suggests that anti-inflammatory agents could prevent these disorders by targeting the maternal inflammatory response. In the present study, we used a rat model of maternal immune activation (MIA) to examine whether maternal quercetin (QE) supplementation can alleviate behavioral deficits and inflammatory mediators in the prefrontal cortex (PFC) and hippocampus of adult male offspring. MethodsPregnant rats were supplemented with QE (50 mg/kg) or vehicle throughout pregnancy and injected with either lipopolysaccharide (0.5 mg/kg) or saline on gestational days 15/16. At postnatal day 60, we evaluated the offspring's behavior, hippocampal and prefrontal cortex glial density, pro-inflammatory gene expression, and neuronal survival. ResultsOur data showed that maternal QE supplementation can prevent working and recognition memory impairments in adult MIA offspring. This behavioral improvement correlates with the decrease in MIA-induced expression of pro-inflammatory genes, microglia, and astrocyte densities, without affecting neuronal survival, in both PFC and CA1 hippocampus areas. ConclusionTherefore, our study supports the potential preventive effect of QE on MIA-induced behavioral dysfunctions, at least in part, by suppressing the glial-mediated inflammatory response.

The in vitro anti-inflammatory mechanism of Porphyra haitanensis oligosaccharides on lipopolysaccharide-induced injury in IEC-6 cells

Porphyra haitanensis, with its rich nutritional value and distinctive flavour, has become a research hotspot in food field. P. haitanensis oligosaccharides (PHO) are oligosaccharides with potential anti-inflammatory properties that ameliorate lipopolysaccharide-induced inflammatory responses in the in vitro IEC-6 cell line model. Here, the structure of PHO was investigated, and LPS–induced injury mechanisms in IEC-6 were determined by cellular, molecular, and transcriptome analyses. After PHO exposure, LPS-induced IEC-6 cells showed reduced apoptosis, decreased oxidative stress levels, improved cell membrane integrity, and paracellular permeability. This study shows that PHO attenuates injury in the IEC-6 cell line by increasing the expression of tight junctions. PHO also inhibited the TLR4/NF-κB pathway and caused downregulation of intracellular pro-inflammatory cytokines, which attenuates LPS-induced injury in an in vitro model, and further offers the possibility of restoring the intestinal barrier. This study provides insight into the role of PHO in alleviating the intestinal epithelial barrier damage.

BitterDB database analysis plus cell stiffness screening identify flufenamic acid as the most potent TAS2R14-based relaxant of airway smooth muscle cells for therapeutic bronchodilation.

Rationale: Bitter taste receptors (TAS2Rs) are abundantly expressed in airway smooth muscle cells (ASMCs), which have been recognized as promising targets for bitter agonists to initiate relaxation and thereby prevent excessive airway constriction as the main characteristic of asthma. However, due to the current lack of tested safe and potent agonists functioning at low effective concentrations, there has been no clinically approved TAS2R-based drug for bronchodilation in asthma therapy. This study thus aimed at exploring TAS2R agonists with bronchodilator potential by BitterDB database analysis and cell stiffness screening. Methods: Bitter compounds in the BitterDB database were retrieved and analyzed for their working subtype of TAS2R and effective concentration. Compounds activating TAS2R5, 10, and 14 at < 100 μM effective concentration were identified and subsequently screened by cell stiffness assay using optical magnetic twisting cytometry (OMTC) to identify the most potent to relax ASMCs. Then the compound identified was further characterized for efficacy on various aspects related to relaxation of ASMCs, incl. but not limited to traction force by Fourier transform traction force microscopy (FTTFM), [Ca2+]i signaling by Fluo-4/AM intensity, cell migration by scratch wound healing, mRNA expression by qPCR, and protein expressing by ELISA. The compound identified was also compared to conventional β-agonist (isoproterenol and salbutamol) for efficacy in reducing cell stiffness of cultured ASMCs and airway resistance of ovalbumin-treated mice. Results: BitterDB analysis found 18 compounds activating TAS2R5, 10, and 14 at < 100 μM effective concentration. Cell stiffness screening of these compounds eventually identified flufenamic acid (FFA) as the most potent compound to rapidly reduce cell stiffness at 1 μM. The efficacy of FFA to relax ASMCs in vitro and abrogate airway resistance in vivo was equivalent to that of conventional β-agonists. The FFA-induced effect on ASMCs was mediated by TAS2R14 activation, endoplasmic reticulum Ca2+ release, and large-conductance Ca2+-activated K+ (BKCa) channel opening. FFA also attenuated lipopolysaccharide-induced inflammatory response in cultured ASMCs. Conclusions: FFA as a potent TAS2R14 agonist to relax ASMCs while suppressing cytokine release might be a favorite drug agent for further development of TAS2R-based novel dual functional medication for bronchodilation and anti-inflammation in asthma therapy.

MicroRNA-181b attenuates lipopolysaccharide-induced inflammatory responses in pulpitis via the PLAU/AKT/NF-κB axis

ObjectiveThis study aimed to investigate the role and underlying mechanisms of microRNA (miRNA)-181b in the inflammatory response in pulpitis. MethodsQuantitative reverse-transcription polymerase chain reaction (qRT-PCR), fluorescence in situ hybridization (FISH), and immunofluorescence techniques were used to determine the miRNA-181b and urokinase-type plasminogen activator (PLAU) expression levels in inflamed human dental pulp tissues (HDPTs) and lipopolysaccharide (LPS)-stimulated human dental pulp cells (hDPCs). The targets of miRNA-181b were identified and confirmed using a bioinformatics analysis, RNA sequencing, and dual-luciferase gene reporter assays. The effect of miRNA-181b or PLAU on proinflammatory cytokine expression in hDPCs was examined using qRT-PCR and western blotting. RNA sequencing was conducted to examine the signaling pathways implicated in miRNA-181b-mediated pulpitis. Western blotting and qRT-PCR were used to determine the miRNA-181b /PLAU/AKT/NF-κB signaling axis in pulpitis. A rat pulpitis model was created to observe the histopathological changes in the dental pulp tissue after the topical application of miRNA-181b agomir. ResultsA significant decrease in miRNA-181b and an increase in PLAU were observed in HDPTs compared to the healthy controls, and these two factors showed a negative correlation. MiRNA-181b directly targeted PLAU. The miRNA-181b inhibitor resulted in a significant upregulation of IL-1β, IL-6 and TNF-α, whereas the knockdown of PLAU reversed this proinflammatory effect. Conversely, PLAU overexpression prevented the anti-inflammatory effects of the miRNA-181b mimics. Mechanistically, miRNA-181b inhibited the AKT/NF-κB pathway by targeting PLAU. In vivo application of the miRNA-181b agomir to inflamed pulp tissue alleviated inflammation. ConclusionMiRNA-181b targets PLAU, negatively regulating pro-inflammatory cytokine expression via the AKT/NF-κB signaling pathway.

Mutanolysin-Digested Peptidoglycan of Lactobacillus reuteri Promotes the Inhibition of Porphyromonas gingivalis Lipopolysaccharide-Induced Inflammatory Responses through the Regulation of Signaling Cascades via TLR4 Suppression.

Periodontitis is an oral infectious disease caused by various pathogenic bacteria, such as Porphyromonas gingivalis. Although probiotics and their cellular components have demonstrated positive effects on periodontitis, the beneficial impact of peptidoglycan (PGN) from probiotic Lactobacillus remains unclear. Therefore, our study sought to investigate the inhibitory effect of PGN isolated from L. reuteri (LrPGN) on P. gingivalis-induced inflammatory responses. Pretreatment with LrPGN significantly inhibited the production of interleukin (IL)-1β, IL-6, and CCL20 in RAW 264.7 cells induced by P. gingivalis lipopolysaccharide (LPS). LrPGN reduced the phosphorylation of PI3K/Akt and MAPKs, as well as NF-κB activation, which were induced by P. gingivalis LPS. Furthermore, LrPGN dose-dependently reduced the expression of Toll-like receptor 4 (TLR4), indicating that LrPGN inhibits periodontal inflammation by regulating cellular signaling cascades through TLR4 suppression. Notably, LrPGN exhibited stronger inhibition of P. gingivalis LPS-induced production of inflammatory mediators compared to insoluble LrPGN and proteinase K-treated LrPGN. Moreover, MDP, a minimal bioactive PGN motif, also dose-dependently inhibited P. gingivalis LPS-induced inflammatory mediators, suggesting that MDP-like molecules present in the LrPGN structure may play a crucial role in the inhibition of inflammatory responses. Collectively, these findings suggest that LrPGN can mitigate periodontal inflammation and could be a useful agent for the prevention and treatment of periodontitis.

MiR-4763-3p accelerates lipopolysaccharide-induced cardiomyocyte apoptosis and inflammatory response by targeting IL10RA.

In order to investigate miR-4763-3p and associated genes' roles in myocarditis, AC16 cell line was divided into LPS + miR-4763-3p inhibitor, LPS + NC inhibitor, LPS + miR-4763-3p inhibitor + si-IL10RA and NC groups, and Q-PCR was used to find out whether miR-4763-3p was expressed; Targetscan, Genecards, and MiRDB were used to estimate the miR-4763-3p target; Targetscan was used to display binding sites. Western blot assay was undertaken to detect Bax, Bcl-2, and IL10RA expression. Proliferation and apoptosis were processed using CCK8 and the flow cytometry assay, respectively. Migration and invasion were confirmed utilizing Transwell test. ELISA assay was processed to show the content of IL-6, IL-1ß, IL-10 and TGF-ß in the cell culture supernatant. After being exposed to LPS, cardiomyocyte cells expressed more miR-4763-3p. MiR-4763-3p inhibitor accelerated proliferation, migration and invasion behavior, while it also decreased apoptosis rate in LPS-treated cardiomyocyte cells. MiR-4763-3p inhibitor attenuated the inflammatory response by up-regulating Bax expression and down-regulating Bcl-2 level in LPS-treated cardiomyocyte cells. In cardiomyocyte cells treated with LPS, MiR-4763-3p expression was elevated. si-IL10RA The miR-4763-3p inhibitor restored its effects. MiR-4763-3p accelerates lipopolysaccharide-induced cardiomyocyte apoptosis and inflammatory response by targeting IL10RA, which might be a potential target for myocarditis.

The Protective Action of Hsp70 and Hydrogen Sulfide Donors in THP-1 Macrophages in the Lipopolysaccharide-Induced Inflammatory Response by Modulating Endocytosis

—Hsp70 and hydrogen sulfide donors reduce inflammatory processes in human and animal cells. The biological action mediated by Hsp70 and H2S donors (GYY4137 and sodium thiosulfate) depends on their protection kinetics from cell activation by lipopolysaccharides. However, the molecular mechanisms of action of Hsp70 and H2S are not well understood. We studied the effect of human recombinant Hsp70 and H2S donors on the formation of reactive oxygen species and tumor necrosis factor-alpha induced in human cells (THP-1) by lipopolysaccharides. Transcriptomic changes occurring in these cells after LPS administration in combination with GYY4137 pretreatment were investigated. The results we obtained showed that Hsp70 and hydrogen sulfide donors reduce inflammatory processes in cells activated by the action of LPS. Hsp70 and H2S donors differed in the kinetics of the protective action, while hydrogen sulfide donors turned out to be more effective. The role of endocytosis in the mechanisms of protection of cells by H2S and Hsp70 donors from the action of LPS was studied. It has been found that GYY4137 pretreatment of LPS-exposed cells reduces the LPS-induced induction of various pro-inflammatory genes and affects the expression of genes of various intracellular signaling pathways.

Isobavachin, a main bioavailable compound in Psoralea corylifolia, alleviates lipopolysaccharide-induced inflammatory responses in macrophages and zebrafish by suppressing the MAPK and NF-κB signaling pathways

Ethnopharmacological relevancePsoralea corylifolia L. (PC) is widely used in traditional medicines to treat inflammatory and infectious diseases. Isobavachin (IBC) is a bioavailable prenylated flavonoid derived from PC that has various biological properties. However, little information is available on its anti-inflammatory effects and mechanisms of action. Aim of the studyIn this study, we aimed to determine the anti-inflammatory effects of IBC in vitro and in vivo by conducting a mechanistic study using murine macrophages. Materials and methodsWe evaluated the modulatory effects of IBC on the production of pro-inflammatory cytokines and mediators in murine macrophages. In addition, we examined whether IBC inhibits lipopolysaccharide (LPS)-induced inflammatory responses in a zebrafish model. Alterations in inflammatory response-associated genes and proteins were determined using quantitative reverse transcriptional polymerase chain reaction (RT-qPCR) and Western blotting analysis. ResultsIBC markedly reduced the overproduction of inflammatory mediators, pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear translocation of nuclear factor-kappa B (NF-κB) in macrophages induced by lipopolysaccharides (LPS). In addition, excessive NO, ROS, and neutrophil level induced by LPS, were suppressed by IBC treatment in a zebrafish inflammation model. ConclusionsCollectively, bioavailable IBC inhibited on the inflammatory responses by LPS via MAPK and NF-κB signaling pathways in vitro and in vivo, suggesting that it may be a potential modulatory agent against inflammatory disorders.

Study on the Alleviating Effect and Potential Mechanism of Ethanolic Extract of Limonium aureum (L.) Hill. on Lipopolysaccharide-Induced Inflammatory Responses in Macrophages.

Inflammation is the host response of immune cells during infection and traumatic tissue injury. An uncontrolled inflammatory response leads to inflammatory cascade, which in turn triggers a variety of diseases threatening human and animal health. The use of existing inflammatory therapeutic drugs is constrained by their high cost and susceptibility to systemic side effects, and therefore new therapeutic candidates for inflammatory diseases need to be urgently developed. Natural products are characterized by wide sources and rich pharmacological activities, which are valuable resources for the development of new drugs. This study aimed to uncover the alleviating effect and potential mechanism of natural product Limonium aureum (LAH) on LPS-induced inflammatory responses in macrophages. The experimental results showed that the optimized conditions for LAH ultrasound-assisted extraction via response surface methodology were an ethanol concentration of 72%, a material-to-solvent ratio of 1:37 g/mL, an extraction temperature of 73 °C, and an extraction power of 70 W, and the average extraction rate of LAH total flavonoids was 0.3776%. Then, data of 1666 components in LAH ethanol extracts were obtained through quasi-targeted metabolomics analysis. The ELISA showed that LAH significantly inhibited the production of pro-inflammatory cytokines while promoting the secretion of anti-inflammatory cytokines. Finally, combined with the results of network pharmacology analysis and protein expression validation of hub genes, it was speculated that LAH may alleviate LPS-induced inflammatory responses of macrophages through the AKT1/RELA/PTGS2 signaling pathway and the MAPK3/JUN signaling pathway. This study preliminarily revealed the anti-inflammatory activity of LAH and the molecular mechanism of its anti-inflammatory action, and provided a theoretical basis for the development of LAH as a new natural anti-inflammatory drug.

Protective Action of HSP70 and Hydrogen Sulfide Donors in THP-1 Macrophages at Lipopolysaccharide-Induced Inflammatory Response by Modulating Endocytosis

Protective Action of HSP70 and Hydrogen Sulfide Donors in THP-1 Macrophages at Lipopolysaccharide-Induced Inflammatory Response by Modulating Endocytosis