TLR4 mRNA Expression Research Articles

Role of mechanosensitive Piezo1 receptor expressed on macrophage in Periodontitis

Abstract Objectives: The mechanosensitive Ca 2+ion channels, Piezo1, converts the mechanical stimulus into cell signals in a variety of immune cells. However, the pathophysiological property of Piezo1 in the oral polymicrobial infectious disease of periodontitis is largely unknown. This study investigated the role of Piezo1 in the inflammatory and phagocytic reactions by RAW264.7 macrophages in response to the exposures to periodontal pathogen, P.gingivalis. Experimental methods: Short hairpin RNA (shRNA) vector for Piezo1 or control scrambled sequence was transfected to RAW264.7 cells. Then, RAW264.7 cells were incubated for 24 hours in the presence or absence of whole P.gingivalis(MOI; 10) or outer membrane vesicles (OMVs, 1 μg/ml) isolated from P.gingivalis, w or w/o Yoda1 (synthetic Piezo1 activator), or shear stress. qPCR was used to monitor the mRNA expressions of Piezo1, TNF-α, TLR-2, and TLR-4, whereas TNF-α protein was detected by ELISA. RAW264.7’s phagocytic ability was evaluated by cytoplasm-internalization of pHrodo-labeled whole P.gingivalisor OMVs using a flow cytometer. Results: OMVs induced more TNF-α production and phagocytosis by RAW264.7 cells than whole P.gingivalis, both of which were further upregulated by Yoda1 as well as shear stress (p<0.05, ANOVA). Shear stress combined with OMV-stimulation upregulated the gene expression of TLR-4, while downregulating TLR-2 gene in RAW264.7 cells. The shRNA-targeting Piezo1 significantly suppressed the TNF-α production and internalization of OMVs by RAW264.7 cells compared control scramble shRNA (p<0.05, ANOVA). Conclusion: The present study indicated that mechanical stress may dysregulate the macrophage-mediated innate immune responses in periodontitis. NIH NIDCR grants, DE-027851, DE-028715 and DE-029709

Yifei Jianpi recipe improves cigarette smoke-induced inflammatory injury and mucus hypersecretion in human bronchial epithelial cells by inhibiting the TLR4/NF-κB signaling pathway

To explore the mechanism of Yifei Jianpi recipe for improving cigarette smoke- induced inflammatory injury and mucus hypersecretion in cultured human bronchial epithelial cells. Serum samples were collected from 40 SD rats treated with Yifei Jianpi recipe (n=20) or normal saline (n=20) by gavage. Cultured human bronchial epithelial 16HBE cells were stimulated with an aqueous cigarette smoke extract (CSE), followed by treatment with the collected serum at different dilutions. The optimal concentration and treatment time of CSE and the medicated serum for cell treatment were determined with CCK-8 assay. The expressions of TLR4, NF-κB, MUC5AC, MUC7, and muc8 at both the mRNA and protein levels in the treated cells were examined with RT- qPCR and Western blotting, and the effects of TLR4 gene silencing and overexpression on their expressions were assessed. The expressions of TNF-α, IL-1 β, IL-6 and IL-8 in the cells were detected using ELISA. At the optimal concentration of 20%, treatment with the medicated serum for 24 h significantly lowered the mRNA and protein expressions of TLR4, NF- κB, MUC5AC, MUC7, and MUC8 in CSE- exposed 16HBE cells, and these effects were further enhanced by TLR4 silencing in the cells. In 16HBE cells with TLR4 overexpression, the expressions of TLR4, NF-κB, MUC5AC, MUC7, and MUC8 were significantly increased after CSE exposure and were lowered following treatment with the medicated serum (P < 0.05). The medicated serum also significantly lowered the levels of TNF-α, IL-1β, IL-6 and IL-8 in CSE-exposed 16HBE cells (P < 0.05). In the 16HBE cell model of chronic obstructive pulmonary disease (COPD), treatment with Yifei Jianpi recipe-medicated serum improves inflammation and mucus hypersecretion possibly by reducing MUC secretion and inhibiting the TLR4/NF-κB signaling pathway.

Abstract 3947: S100A8/A9-RAGE pathway and chronic airway inflammation in cigarette smoke-induced lung carcinogenesis

Abstract Background: Cigarette smoke-induced chronic airway inflammation increases the risk of lung cancer, and plays a multifaceted role in lung cancer initiation and progression, and RAGE-ligand axis (HMGB1, S100A8/A9) contributes Cigarette smoke-induced persistent and progressive inflammation. The aim of the present study was to determine the inflammatory effect on S100A8/A9-RAGE pathway in smoke-induced carcinogenesis in lung cancer. Methods: Human alveolar adenocarcinoma cells (A549) and normal bronchial epithelial cells (BEAS-2B) were co-cultured for 24 h with the PBMC and then, cells were incubated in the presence or absence of 1.5% cigarette smoke extract (CSE) for 24 h. The cells transfected with siRNA targeting S100A8/9 or RAGE. The cell viability, colony-forming ability, migration, invasion, metastasis and morphological changes were assessed. Female A/J mice were given a benzo(a)pyrene (100mg/kg) in 0.1 ml corn oil via oral gavage at once a week for 3 weeks, and administrated CSE (1.25 ul/g) via intratracheal (IT) at twice a week for 4 weeks. Tumor load was determined by averaging the total tumor volume in each group. BAL differential cells were counted to analyze inflammatory cells. Results: Cellular growth and colony-forming were promoted by exposure to CSE, and significantly inhibited by S100A8/9 and RAGE-siRNA transfection, especially in A549 cells than BEAS-2B. Cell migration, invasion, MMP-2/9 activities, and the mRNA and protein expression of TLR4, NF-κB, RAGE, S100A8/9 and HMBG1 were higher in CSE exposed A549 cells. S100A8/9 and RAGE-siRNA transfection attenuated those expression, significantly. B(a)P induced an average tumor volume 7.28 mm3 per mouse, and CSE significantly increased tumor volume (8.10 mm3) compared to the B(a)P group. The total cell number and lymphocytes in BAL fluids tended to increase after CSE administration in lung cancer mouse group. Moreover, CSE significantly induced the levels of S100A8/9 and RAGE, p38 and p-ERK, and decreased JNK in serum and tumors with adjacent lung tissues (p &amp;lt; 0.05). Conclusions: We identified cigarette smoke-induced S100A8/A9-RAGE pathway promoted airway inflammation and lung carcinogenesis in vitro and in vivo. Although S100A8/A9 protein contributes to many types of disease, this study will help us gain a better understanding of the complexities of cancer progression. Further studies are needed for therapeutic target of cigarette smoke-induced inflammation and immunosuppression in tumor microenviornment. Citation Format: Hye Seon Kang, In Kyoung Kim, Chang Dong Yeo, Jin Woo Kim, Sang Haak Lee. S100A8/A9-RAGE pathway and chronic airway inflammation in cigarette smoke-induced lung carcinogenesis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3947.

An active fraction from Spatholobus suberectus dunn inhibits the inflammatory response by regulating microglia activation, switching microglia polarization from M1 to M2 and suppressing the TLR4/MyD88/NF-κB pathway in LPS-stimulated BV2 cells

Neurodegenerative disorders are known to be associated with neuroinflammation caused by microglia. Therefore, regulation of microglia activation and polarization to inhibit neuroinflammatory reactions seems to hold promise as a therapeutic approach in neurodegenerative disorders. Spatholobus suberectus Dunn (SSD) has been utilized as a traditional Chinese medicine remedy for brain diseases for thousands of years. SSD possesses various pharmacological activities, such as circulation invigoration, neuroprotection, and anti-inflammatory. The objective of this research was to examine the anti-neuroinflammatory effects and molecular mechanisms of an active fraction from SSD (ASSD) in vitro culture BV2 cells, a type of mouse microglia cell line. The inflammatory responses in BV2 cells were induced by stimulating them with 1 μg/mL lipopolysaccharide (LPS) and the effects of ASSD on LPS-stimulated inflammation were monitored. Besides, by using the methods of Western blot, immunofluorescence, and RT-PCR, the mechanisms of ASSD on microglia activation, M1/M2 polarization, and the TLR4/MyD88/NF-κB pathway were investigated. Our findings demonstrate that the treatment doses of ASSD neither induce cytotoxicity nor promote the production of inflammatory cytokines. In addition, immunofluorescence analysis show that ASSD inhibited the expression of ionized calcium-binding adapter molecule 1(Iba1) and inducible nitricoxide synthase (iNOS), and induced arginase 1 (Arg1) expression. Moreover, Western blot analysis indicated that ASSD significantly down-regulated TLR4, MyD88, p-IκB, NF-κB p65, and NF-κB p-p65 protein expression levels. Furthermore, RT-qPCR assay show that ASSD significantly down-regulated iNOS, TLR4, MyD88, and NF-κB mRNA expression levels, and up-regulated Arg1 mRNA expression level. According to the findings, ASSD can suppress microglia-mediated inflammatory responses by modulating microglia activation, inducing a shift from M1 to M2 polarization, and inhibiting the TLR4/MyD88/NF-κB signaling pathway.

Bone-Marrow-Derived Mesenchymal Stem Cells Attenuate Behavioral and Cognitive Dysfunction after Subarachnoid Hemorrhage via HMGB1-RAGE Axis Mediation.

We evaluated the therapeutic effects of bone-marrow-derived mesenchymal stem cells (BMSCs) on behavioral and cognitive function in a mouse model of mild subarachnoid hemorrhage (SAH) and explored the underlying mechanisms in conjunction with the HMGB1-RAGE axis. The SAH models were generated in a total of 126 male C57BL/6J mice via endovascular perforation and evaluated 24 h and 72 h after the intravenous administration of BMSCs (3 × 105 cells). The BMSCs were administered once, at 3 h, or twice, at 3 h and 48 h after the model induction. The therapeutic effects of the BMSCs were compared to those of the saline administration. Compared to saline-treated SAH-model mice, at 3 h, the mice with mild SAH treated with the BMSCs showed significant improvements in their neurological scores and cerebral edema. The administration of the BMSCs decreased the mRNA expression of HMGB1, RAGE, TLR4, and MyD88, as well as the protein expression of HMGB1 and phosphorylated NF-kB p65. Furthermore, the numbers of slips per walking time, impairments in short-term memory, and the recognition of novel objects were improved. There was some improvement in inflammatory-marker levels and cognitive function according to the BMSCs' administration times, but no large differences were seen. The administration of BMSCs improved behavioral and cognitive dysfunction by ameliorating HMGB1-RAGE axis-mediated neuroinflammation after SAH.

In vitro evaluation of ginsenoside Rg1 immunostimulating effect in bovine mononuclear cells

The aim of this study was to evaluate the immunomodulatory effect of ginsenoside Rg1 on mammary secretion and peripheral blood mononuclear cells (MSMC and PBMC, respectively). The mRNA expression of TLR2, TLR4 and selected cytokines were evaluated on MSMC after Rg1 treatment. Also, TLR2 and TLR4 protein expression was evaluated on MSMC and PBMC after Rg1 treatment. Phagocytic activity and capacity, ROS production and MHC-II expression were evaluated on MSMC and PBMC after Rg1 treatment and co-culture with Staphylococcus aureus strain 5011. Rg1 induced mRNA expression of TLR2, TLR4, TNF-α, IL-1β, IL-6 and IL-8 in groups treated with different concentrations and at different times in MSMC, and induced TLR2 and TLR4 protein expression in MSMC and PBMC. Rg1 increased phagocytic capacity and ROS production in MSMC and PBMC. Rg1 increased MHC-II expression by PBMC. However, Rg1 pre-treatment had no effect on cells co-cultured with S. aureus. In conclusion, Rg1 was able to stimulate several sensing and effector activities in these immune cells.

Effects of dexmedetomidine combined with sufentanil on injury and expression of high mobility group box protein B1/toll-like receptors signaling pathway in rats with pancreatitis

Pancreatitis is a common disease of digestive system, easy to deteriorate, acute onset, poor prognosis, high fatality rate. Analgesic and sedative drugs are often used to treat pancreatitis. Dexmedetomidine is an adrenergic receptor agonist, and Sufentanil is a common analgesic sedative. However, the mechanism of their combined use in the treatment of pancreatitis injury has not been fully elucidated. Wistar rat pancreatitis Model was established and randomly divided into 4 groups: Dex group, Dex+Suf group, model group and Sufentanil group. Compare and analyze heart rate, oxygen saturation, body temperature, and respiration. The onset time, duration, analgesic time and adverse reactions were recorded. Serum amylase, creatinine and alanine aminotransferase were detected. Serum IL-6 and IL-1β levels were detected, and apoptotic activity was detected by Caspase 3 activity kit. The expression of HMGB1, TLR2 and TLR4 mRNA in pancreatic tissues. Dexmedetomide alone or combined with sufentanil can improve the general indicators, sedation and analgesia time is shorter, longer duration. Serum secretion of IL-6 and IL-1β decreased, expression of HMGB1, TLR2 and TLR4 decreased, pancreatic serological serum amylase, creatinine, alanine aminotransferase activities decreased, Caspase 3 activity decreased. The curative effect of combination group was significantly higher than that of model group (p &lt; 0.01). Dexmedetomidine combined with sufentanil can affect the expression of HMGB1/TLRs, inhibit inflammation, improve sedation and analgesia, and inhibit apoptosis, so as to alleviate the injury of acute pancreatitis.

Effect of electroacupuncture on Notch/NF-κB signaling pathway in colonic mucosa of mice with ulcerative colitis

To observe the protective effect of electroacupuncture (EA) on the intestinal mucosal barrier and its relationship with the Notch/NF-κB signaling pathway in mice with ulcerative colitis (UC), so as to explore its mechanism of treating UC. Male C57BL/6J mice were randomized into control, model and EA groups, with 6 mice in each group. The UC model was established by giving the mice with 2% Dextran Sulfate Sodium (DSS) for 7 days. EA (2 Hz/15 Hz, 0.2 mA) was applied at bilateral "Zusanli" (ST36) for 30 min, once a day for 7 days. The disease activity indexes ［DAI=(body weight index score+stool score+bleeding score)/3; 0-4 points］ of mice were calculated. The morphological changes of colonic tissues of mice in each group were observed by HE staining, and serum contents of TNF-α and IL-6 were detected by ELISA. Claudin-1 protein expression in colon tissue was detected by immunofluorescence, while the protein expression levels of Muc-2, Notch-1, MMP-9 in colon tissue were detected by immunohistochemistry. The real-time PCR method was used to detect the expression levels of Notch-1, Hes-1, NF-κB, TLR-4 and AKT mRNA in colon tissues. After modeling, the DAI, serum TNF-α and IL-6 contents, Notch-1 and MMP-9 protein expression, the relative expression levels of Notch-1, Hes-1, NF-κB, TLR-4 and AKT mRNA in the colonic tissue were significantly increased (P<0.001, P<0.01) in the model group relevant to the control group. At the same time, Claudin-1 and Muc-2 protein expression were significantly reduced (P<0.01). After the EA intervention, the increased DAI score, TNF-α and IL-6 contents, Notch-1 and MMP-9 protein expression, the relative expressions of Notch-1, Hes-1, NF-κB, TLR-4 and AKT mRNA, and the decreased Claudin-1 and Muc-2 protein expression were all reversed compared with the model group (P<0.05, P<0.01, P<0.001). H.E. staining of the colonic tissue showed damage and infiltration of inflammatory cells in the model group, and those were significantly improved in the EA group. EA can promote the recovery of intestinal mucosal barrier function and reduce inflammatory reaction in UC mice, which may be associated with its effects in inhibiting the excessive activation of the Notch/NF-κB signaling pathway.

Baicalein prevents capecitabine-induced heart damage in female Wistar rats and enhances its anticancer potential in MCF-7 breast cancer cells

AimWe investigated the ability of baicalein (BAI) to enhance the anticancer potential of capecitabine (CAP) in the MCF-7 cell line and its protective effect on CAP-induced cardiotoxicity in female Wistar rats. Methods and key findingsIn vitro study involved evaluating the effect of BAI and/or CAP on cell viability, cell cycle progression, and BAX and Bcl2 gene expression in MCF-7 cells. Co-treatment of BAI with CAP significantly reduced the viability of MCF-7 cells, improved their cytotoxic effect, markedly elevated the percentage of the sub-G1 population, drastically reduced the G2/M population, and significantly altered the mRNA expression of BAX and Bcl2 genes compared with each treatment alone. In vivo study revealed that the oral administration of CAP (140 mg/kg BW) to adult female rats significantly elevated the levels of serum creatine kinase-myocardial band (CK-MB), lactate dehydrogenase (LDH), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β and cardiac TNF-α, IL-1β malondialdehyde (MDA) concentration, whereas it reduced the serum and cardiac total antioxidant capacity (TAC), level of cardiac glutathione (GSH) and activity of glutathione peroxidase (GPx) with a vast array of circulatory, inflammatory, degenerative, and necrotic alterations in the cardiac tissue. Furthermore, CAP administration significantly upregulated the mRNA expression of NF-κB, TLR4, MyD88, ATF6, CHOP, and JNK genes. Concurrent administration of BAI (200 mg/kg BW) and CAP significantly improved the biochemical alterations and cardiac oxidant/antioxidant status and architecture. In addition, it modulated the TLR4/MyD88/NF-κB pathway and endoplasmic reticulum stress. SignificanceAltogether, BAI can augment the anticancer potential of CAP and alleviate its cardiotoxic effects during cancer treatment.

Centella Asiatica (GOTU KOLA) TREATMENT ATTENUATES PRO-INFLAMMATORY MEDIATORS IN LIVER OF RATS WITH ELECTRICAL FOOT SHOCK STRESS MODEL

Background: Stress induces secretion of cathecolamines and glucocorticoids, which may produce liver injury. Followed by the production of inflammatory mediators, it causes apoptosis. Centella asiatica (CeA) has anti-inflammatory and hepatoprotective effects. The present study aims to determine the role of CeA in the attenuation of liver pro-inflammatory mediator expression in rats with electrical foot shock stress model. Materials and Methods: Twenty-four Sprague-Dawley rats were randomized into four groups consisted of six rats each: (1) Control group, (2) CeA-treated group, (3) Stress group, and (4) CeA + stress group. Reverse transcriptase PCR of inflammatory and apoptosis markers as well as Real-Time PCR of β2-adrenergic receptor were performed from liver tissues. Results: Electrical foot shock stress induced up-regulation of NFκB and TNF-α mRNA expressions as pro-inflammatory mediators, compared to control group. This alteration was followed by up-regulation of BAX and β2-adrenergic receptor, as well as the down-regulation of BCl2 compared to control. CeA treatment prevented enhancement of NFκB, TNF-α, TLR-4 and β-adrenergic receptor mRNA expressions, which was followed by down-regulation of BAX and up-regulation of BCl-2, compared to stress group. Conclusion: CeA prevents secretion of pro-inflammatory chemokines and cytokines as well as apoptotic markers in liver cells through the activation of β2-adrenergic receptor.

Luteolin Protects Against Obese Sarcopenia in Mice with High-Fat Diet-Induced Obesity by Ameliorating Inflammation and Protein Degradation in Muscles.

Although sarcopenia is mainly caused by aging, sarcopenia due to obesity has become an emerging issue given the increase in obesity among people of various ages. There are studies on obesity or sarcopenia, our understanding of obesity-mediated sarcopenia is insufficient. Luteolin (LU) has exhibited antiobesity effects, but no studies have investigated the LU effects on antisarcopenia. This study therefore investigated the effects of LU on obese sarcopenia in mice with high-fat diet (HFD)-induced obesity. To evaluate its inhibitory efficacy against obese sarcopenia, 5-week-old mice are fed an HFD supplemented with LU for 20weeks. LU exerts suppressive effects on obesity, inflammation, and protein degradation in the HFD-fed obese mice. It also inhibits lipid infiltration into the muscle and decreases p38 activity and the mRNA expression of inflammatory factors, including TNF-α, Tlr2, Tlr4, MCP1, and MMP2, in the muscle. The suppression of muscle inflammation by LU leads to the inhibition of myostatin, FoxO, atrogin, and MuRF expression. These effects of LU affect inhibition of protein degradation and improvement of muscle function. Here, it demonstrates that LU's antiobesity and antiinflammatory functionality affect inhibition of muscle protein degradation, and consequently, these interactions by LU exerts a protective effect against obese sarcopenia.

TMPRSS2 Impacts Cytokine Expression in Murine Dendritic Cells.

The transmembrane protease serine 2 (TMPRSS2) proteolytically activates the envelope proteins of several viruses for viral entry via membrane fusion and is therefore an interesting and promising target for the development of broad-spectrum antivirals. However, the use of a host protein as a target may lead to potential side effects, especially on the immune system. We examined the effect of a genetic deletion of TMPRSS2 on dendritic cells. Bone marrow cells from wild-type (WT) and TMPRSS2-deficient mice (TMPRSS2-/-) were differentiated to plasmacytoid dendritic cells (pDCs) and classical DCs (cDCs) and activated with various toll-like receptor (TLR) agonists. We analyzed the released cytokines and the mRNA expression of chemokine receptors, TLR7, TLR9, IRF7 and TCF4 stimulation. In cDCs, the lack of TMPRSS2 led to an increase in IL12 and IFNγ in TLR7/8 agonist resiquimod or TLR 9 agonist ODN 1668-activated cells. Only IL-10 was reduced in TMPRSS2-/- cells in comparison to WT cells activated with ODN 1668. In resiquimod-activated pDCs, the lack of TMPRSS2 led to a decrease in IL-6, IL-10 and INFγ. ODN 1668 activation led to a reduction in IFNα. The effect on receptor expression in pDCs and cDCs was low. The effect of TMPRSS2 on pDCS and cDCs depends on the activated TLR, and TMPRSS2 seems to affect cytokine release differently in pDCs and cDCs. In cDCs, TMPRSS2 seems to suppress cytokine release, whereas in pDCS TMPRSS2 possibly mediates cytokine release.

Nasopharyngeal epithelial cells from patients with coronavirus disease 2019 express abnormal levels of Toll-like receptors

ABSTRACT Aberrant activation of the immune system has been attributed with etiology and pathogenesis of coronavirus disease 2019 (COVID-19). Here, the transcript levels of toll-like receptors (TLRs) were measured in the nasopharyngeal epithelial cells obtained from COVID-19 patients to assess the involvement of these molecules in the clinical outcome of COVID-19 patients. Nasopharyngeal swab samples were used to obtain epithelial cells from 120 COVID-19 patients and 100 healthy controls. COVID-19 cases were classified into those having clinical symptoms/needing for hospitalization, having clinical symptoms/not needing for hospitalization, and those without clinical symptoms‌. The mRNA expression levels of TLRs were measured in the nasopharyngeal epithelial cells. Overall, mRNA expression of TLR1, TLR2, TLR4, and TLR6 was significantly higher in COVID-19 cases compared to controls. The mRNA expression of TLRs were all higher significantly in the samples from COVID-19 patients having clinical symptoms and needing hospitalization as well as in those with clinical symptoms/not needing for hospitalization in comparison to controls. TLR expression was significantly higher in those with clinical symptoms/needing for hospitalization and those with clinical symptoms/not needing for hospitalization compared to COVID-19 cases without clinical symptoms. In cases with clinical symptoms/needing for hospitalization and those with clinical symptoms/not needing for hospitalization, there was a correlation between TLR expression and clinicopathological findings. In conclusion, aberrant expression of TLRs in the nasopharyngeal epithelial cells from COVID-19 cases may predict the severity of the diseases and necessity for supportive cares in the hospital.

Scavenger receptor BI attenuates oxidized phospholipid-induced pulmonary inflammation

Damage associated molecular patterns (DAMPs) are molecules released from dead/dying cells following toxicant and/or environmental exposures that activate the immune response through binding of pattern recognition receptors (PRRs). Excessive production of DAMPs or failed clearance leads to chronic inflammation and delayed inflammation resolution. One category of DAMPs are oxidized phospholipids (oxPLs) produced upon exposure to high levels of oxidative stress, such as following ozone (O3) induced inflammation. OxPLs are bound by multiple classes of PRRs that include scavenger receptors (SRs) such as SR class B-1 (SR-BI) and toll-like receptors (TLRs). Interactions between oxPLs and PRRs appear to regulate inflammation; however, the role of SR-BI in oxPL-induced lung inflammation has not been defined. Therefore, we hypothesize that SR-BI is critical in protecting the lung from oxPL-induced pulmonary inflammation/injury. To test this hypothesis, C57BL/6J (WT) female mice were dosed with oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine (oxPAPC) by oropharyngeal aspiration which increased pulmonary SR-BI expression. Following oxPAPC exposure, SR-BI deficient (SR-BI−/−) mice exhibited increased lung pathology and inflammatory cytokine/chemokine production. Lipidomic analysis revealed that SR-BI−/− mice had an altered pulmonary lipidome prior to and following oxPAPC exposure, which correlated with increased oxidized phosphatidylcholines (PCs). Finally, we characterized TLR4-mediated activation of NF-κB following oxPAPC exposure and discovered that SR-BI−/− mice had increased TLR4 mRNA expression in lung tissue and macrophages, increased nuclear p65, and decreased cytoplasmic IκBα. Overall, we conclude that SR-BI is required for limiting oxPAPC-induced lung pathology by maintaining lipid homeostasis, reducing oxidized PCs, and attenuating TLR4-NF-κB activation, thereby preventing excessive and persistent inflammation.

Apple peel polyphenol alleviates antibiotic-induced intestinal dysbiosis by modulating tight junction proteins, the TLR4/NF-κB pathway and intestinal flora.

The intestine and its flora have established a strong link with each other and co-evolved to become a micro-ecological system that plays an important role in human health. Plant polyphenols have attracted a great deal of attention as potential interventions to regulate the intestinal microecology. In this study, we investigated the effects of apple peel polyphenol (APP) on the intestinal ecology by establishing an intestinal ecological dysregulation model using lincomycin hydrochloride-induced Balb/c mice. The results showed that APP enhanced the mechanical barrier function of mice by upregulating the expression of the tight junction proteins at the transcriptional and translational levels. In terms of the immune barrier, APP downregulated the protein and mRNA expression of TLR4 and NF-κB. As for the biological barrier, APP promoted the growth of beneficial bacteria as well as increasing the diversity of intestinal flora. In addition, APP treatment significantly increased the contents of short-chain fatty acids in mice. In conclusion, APP can alleviate intestinal inflammation and epithelial damage as well as inducing potentially beneficial changes in the intestinal microbiota, which helps to reveal the potential mechanisms of host-microbial interactions and polyphenol regulation of intestinal ecology.

Toll-Like Receptor 7 a Novel Non-Invasive Inflammatory Genetic Sensor for Ulcerative Colitis Remission Monitoring.

Ulcerative colitis (UC) and Crohn's disease (CD) are two major types of inflammatory bowel diseases (IBDs). Toll-like receptors (TLRs) are expressed in the innate immune system compartments, in charge of identifying a wide range of microorganisms. The aim of the present study was to evaluate the expression of TLR-2, -7, and -8 in peripheral blood mononuclear cells (PBMC) of UC patients as a novel non-invasive primary inflammation sensor for monitoring the clinical course of UC candidates. In this cross-sectional study, total RNA was extracted from the PBMC of 42 UC patients along with 20 healthy donors. The mRNA levels of TLR-2, -7, and -8 were assessed using the quantitative real-time polymerase chain (qRT-PCR) reaction. The present research study demonstrated no significant changes in TLR-2 mRNA expression in UC patients in comparison with the control group (P = 0.1264), whereas significant elevation (P = 0.0008) was distinguished in the TLR-7 expression of UC participants specifically during the remission course compared with healthy donors and flareup patients (P = 0.0004 and P = 0.0063, respectively). The last selected TLR, TLR-8 was not shown remarkable changes either between UC patients and the control group or between clinical courses of the disease. Here, among three nominated TLRs for predicting UC patients, TLR-7 was potentially selected according to the significant difference in mRNA expression in flareup UC patients and control donors. TLR-7 could be used as a novel non-invasive biomarker for monitoring UC patients in the active course of the disease.

Cyclosporine Ameliorates Silica-Induced Autoimmune Hepatitis in Rat Model by Altering the Expression of Toll-Like Receptor-4, Interleukin-2, and Tumor Necrosis Factor-α.

Autoimmune hepatitis (AIH) is an inflammatory liver disease that is characterized histologically by interface hepatitis, biochemically by elevated transaminase levels, and serologically by the presence of autoantibodies. Toll-like receptor (TLR)-4 is a TLR family member that, upon activation in hepatocytes, initiates a cascade of events. Interleukin-2 (IL-2) and tumour necrosis factor α (TNF-α) are potent inflammatory cytokines secreted in AIH, playing an important role in the early development of inflammation and hepatocyte damage. This study examined the role of cyclosporine in AIH and illustrated its actions on altered hepatic function in the silica-induced AIH model. AIH was induced in Wistar rats using sodium silicate. The rats were divided into four groups: the control group, silica-AIH group, cyclosporine-treated group, and prevention group. TLR-4 and IL-2 mRNA expressions in liver tissues were tested by RTPCR. AIH was associated with up-regulation of liver enzymes, IL-2 and TLR-4 gene expression, while cyclosporine significantly down-regulated the expression of both. The relative quantity of TLR-4 mRNA was 1±0, 13.57±1.91, 4±0.38, and 2±0 in control, AIH, cyclosporine, and prevention groups, respectively (p<0.001). Also, the relative quantity of IL-2 mRNA was 1±0, 14.79±1.42, 7.07±0.96, and 3.4±0.55 in control, AIH, cyclosporine, and prevention groups, respectively (p<0.001). Additionally, immunohistochemical staining for TNF-α in liver sections was increased in the silica-AIH group but was found to decrease in the cyclosporine-treated and prevention groups. This study advocates the therapeutic role of cyclosporine in treating immune-mediated hepatic diseases. Cyclosporine improves histological alterations in the liver and inhibits the production of proinflammatory cytokines.

A Novel TLR4-SYK Interaction Axis Plays an Essential Role in the Innate Immunity Response in Bovine Mammary Epithelial Cells.

Mammary gland epithelium, as the first line of defense for bovine mammary gland immunity, is crucial in the process of mammary glands' innate immunity, especially that of bovine mammary epithelial cells (bMECs). Our previous studies successfully marked SYK as an important candidate gene for mastitis traits via GWAS and preliminarily confirmed that SYK expression is down-regulated in bMECs with LPS (E.&amp;nbsp;coli) stimulation, but its work mechanism is still unclear. In this study, for the first time, in vivo, TLR4 and SYK were colocalized and had a high correlation in mastitis mammary epithelium; protein-protein interaction results also confirmed that there was a direct interaction between them in mastitis tissue, suggesting that SYK participates in the immune regulation of the TLR4 cascade for bovine mastitis. In vitro, TLR4 also interacts with SYK in LPS (E.&amp;nbsp;coli)-stimulated or GBS (S.&amp;nbsp;agalactiae)-infected bMECs, respectively. Moreover, TLR4 mRNA expression and protein levels were little affected in bMECsSYK- with LPS stimulation or GBS infection, indicating that SYK is an important downstream element of the TLR4 cascade in bMECs. Interestingly, IL-1β, IL-8, NF-κB and NLRP3 expression in LPS-stimulated or GBS-infected bMECsSYK- were significantly higher than in the control group, while AKT1 expression was down-regulated, implying that SYK could inhibit the IL-1β, IL-8, NF-κB and NLRP3 expression and alleviate inflammation in bMECs with LPS and GBS. Taken together, our solid evidence supports that TLR4/SYK/NF-κB signal axis in bMECs regulates the innate immunity response to LPS or GBS.

In Vitro Anti-Influenza A Virus H1N1 Effect of Sesquiterpene-Rich Extracts of Carpesium abrotanoides

Due to a high content of sesquiterpenes, Carpesium abrotanoides has been investigated to fully explore its health-promoting properties. Therefore, this work aimed to assess, for the first time, the anti-influenza A virus H1N1 potential of sesquiterpene-targeted fractions of the herb derived from C. abrotanoides. Five compounds, including four sesquiterpenes and one aldehyde, were isolated and identified from the sesquiterpene-rich extracts of C. abrotanoides (SECA), and the contents of three main sesquiterpenes in the SECA were determined. Furthermore, SECA showed a significant protective effect in the MDCK cells infected with influenza A virus (H1N1) in three different conditions: premixed administration, prophylactic administration, and therapeutic administration. SECA can significantly decrease the mRNA expressions of TLR4, MyD88, NF-κB, TNF-α, and IL-6, as well as the protein expressions of TLR4, MyD88, and NF-κB. This result suggests that SECA can resist the influenza A virus H1N1 through the TLR4/MyD88/NF-κB signal pathway.

Deficiency in TLR4 impairs regulatory B cells production induced by Schistosome soluble egg antigen

Regulatory B cells (Bregs) producing IL-10 have negative regulatory function. Several studies have shown the important roles for Toll-like receptor 2 (TLR2), TLR4, and TLR9 ligation in the development of Bregs. We have reported that Schistosome soluble egg antigen (SEA) induced the production of Bregs. However, it remains unclear whether such activation is via the TLR pathway. The present study showed that IL-10 and TLR4 mRNA expression in spleen B cells of significantly increased in C57BL/10 J mice spleen B cells following SEA stimulation. The level of secreted IL-10 and IL-10+ B cell proportion decreased in spleen B cells derived from TLR4-deficient C57BL/10ScNJ (TLR4-/-) mice following SEA or LPS stimulation compared with C57BL/10 J mice. The CD1dhiCD5+ B cells proportion decreased in spleen B cells of TLR4-/- mice following SEA stimulation compared with control mice. NF-κB, ERK, p38MAPK and JNK signal transduction inhibitors significantly suppressed IL-10 secretion in CD1dhiCD5+ B cells induced by SEA or LPS. The phosphorylation levels of IκBα, p65, ERK, JNK and p38 were increased in CD1dhiCD5+ B cell of C57BL/10 J mice treated with LPS or SEA. In conclusion, this study suggests that TLR4 plays a critical role in Bregs activation induced by SEA. And the TLR4-triggered NF-κB and MAPK pathways activation in CD1dhiCD5+ B cells stimulated with SEA. The findings elucidated the mechanism of SEA induction of CD1dhiCD5+ B cells and helped us to understand the immune regulation during Schistosoma japonicum infection.