TLR2 Protein Levels Research Articles

High mobility group box-1 regulates expression of EGFR, VEGF, StAR and TIMP1/2 in bovine granulosa cells through a mechanism involving TLR2/NF-κB

Innate immunity is involved in ovarian activity through aseptic inflammation and tissue repair. High-mobility group box-1 (HMGB1) is related to placental inflammation and a driver of inflammation throughout pregnancy. The aim of this study was to investigate the interaction of HMGB1 with TLR2 in bovine ovarian granulosa cells, and the effects of HMGB1 on bovine ovarian granulosa cells in vitro. The viability of granulosa cells were not affected by HMGB1 with the concentration less than 5 μg/mL. The mRNA levels of TLR2, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), the steroidogenic acute regulatory protein (StAR), tissue inhibitors of matrix (TIMP1/2) of ovarian granulosa cells were upregulated by HMGB1(P < 0.05). The protein levels of TLR2, TLR1 and phosphorylation-NF-κB (p-NF-κB) p65 in ovarian granulosa cells increased in 5 μg/mL HMGB1 group (P < 0.05), and TLR2 decreased in siRNA-2 group (P < 0.05). IL-6 of ovarian granulosa cells was increased by 1 μg/mL and 5 μg/mL HMGB1 (P < 0.05). These results implicate that HMGB1 has interaction with TLR2, TLR1 and p-NF-κB p65 in ovarian granulosa cells, which lead to nuclear translocation of NF-κB p65 and the secretion of interleukin-6 (IL-6). HMGB1 regulates the expression of EGFR, VEGF, StAR, TIMP1/2 and the secretion of IL-6 in ovarian granulosa cells of dairy cows through activating the TLR2/NF-κB signaling pathway, which may be interfere with ovarian physiological activity.

Curcumin Alleviated Dextran Sulfate Sodium-Induced Colitis by Regulating M1/M2 Macrophage Polarization and TLRs Signaling Pathway.

Curcumin has shown good efficacy in mice with experimental colitis and in patients with ulcerative colitis, but the mechanism of action through the regulation of M1/M2 macrophage polarization has not been elaborated. The ulcerative colitis was modeled by dextran sulfate sodium; colitis mice were orally administrated with curcumin (10 mg/kg/day) or 5-ASA (300 mg/kg/day) for 14 consecutive days. After curcumin treatment, the body weight, colon weight and length, colonic weight index, and histopathological damage in colitis mice were effectively improved. The concentrations of proinflammatory cytokines IL-1β, IL-6, and CCL-2 in the colonic tissues of colitis mice decreased significantly, while anti-inflammatory cytokines IL-33 and IL-10 increased significantly. Importantly, macrophage activation was suppressed and M1/M2 macrophage polarization was regulated in colitis mice, and the percentage of CD11b+F4/80+ and CD11b+F4/80+TIM-1+ and CD11b+F4/80+iNOS+ decreased significantly and CD11b+F4/80+CD206+ and CD11b+F4/80+CD163+ increased significantly. Additionally, curcumin significantly downregulated CD11b+F4/80+TLR4+ macrophages and the protein levels of TLR2, TLR4, MyD88, NF-κBp65, p38MAPK, and AP-1 in colitis mice. Our study suggested that curcumin exerted therapeutic effects in colitis mice by regulating the balance of M1/M2 macrophage polarization and TLRs signaling pathway.

Clostridium butyricum Supernatant Regulates the Expression of RORγt in HCT-116 Cells by Inhibiting the TLR2/MyD88/NF-κB Signaling Pathway.

In this study, we treated HCT-116 cells with Clostridium butyricum (C. butyricum) supernatant and observed its effects on the TLR2/MyD88/NF-κB signaling pathway and RORγt, to further explore the possible immune regulatory mechanism of C. butyricum. Our results showed that C. butyricum supernatant downregulated the mRNA and protein levels of TLR2, MyD88, NF-κBp65, and RORγt in HCT-116 cells and the protein levels of phospho-NF-κBp65. Partial blockage of TLR2 by CD282 weakened the inhibitory effects of C. butyricum supernatant on the above pathway components. Those component levels were still inhibited by C. butyricum supernatant after Pam3CSK4 activation of TLR2. In summary, C. butyricum supernatant can inhibit the TLR2/MyD88/NF-κB signaling pathway and the expression of RORγt in HCT-116 cells. These effects are at least partly achieved through inhibition of TLR2.

Toll-like receptor signaling is changed in ovine lymph node during early pregnancy.

Toll-like receptors (TLRs) participate in regulation of adaptive immune responses, and lymph nodes play key roles in the initiation of immune responses. There is a tolerance to the allogenic fetus during pregnancy, but it is unclear that expression of TLR signaling is in ovine lymph node during early pregnancy. In this study, lymph nodes were sampled from day 16 of nonpregnant ewes and days 13, 16, and 25 of pregnant ewes, and the expressions of TLR family (TLR2, TLR3, TLR4, TLR5 and TLR9), adaptor proteins, including myeloid differentiation primary-response protein 88 (MyD88), tumor necrosis factor receptor associated factor 6 (TRAF6), and interleukin-1-receptor-associated kinase 1 (IRAK1), were analyzed through real-time quantitative polymerase chain reaction, Western blot, and immunohistochemistry analysis. The results showed that mRNA and protein levels of TLR2, TLR3, TLR4, TRAF6, and MyD88 were upregulated in the maternal lymph node, but TLR5, TLR9, and IRAK1 were downregulated during early pregnancy. In addition, MyD88 protein was located in the subcapsular sinus and lymph sinuses. Therefore, it is suggested that early pregnancy induces changes in TLR signaling in maternal lymph node, which may be involved in regulation of maternal immune responses in sheep.

Anti-inflammatory effects of luteolin on acute gouty arthritis rats via TLR/MyD88/NF-κB pathway.

To investigate the anti-inflammatory effect of luteolin on the acute gouty arthritis (AGA) rats and the underlying mechanisms. A total of sixty rats were chosen and randomly divided into 5 groups:A control group, a monosodium urate (MSU) group, a colchicine group, 2 luteolin groups (50 mg/kg, 150 mg/kg). The AGA model of rats was established by injecting monosodium urate (MSU) at the concentration of 25 mg/mL into the ankle joint cavity. Changes of joint swelling index at different time points and the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in serum and synovial were measured. The mRNA expression of TLR2, TLR4, and MyD88 in synovial tissue was detected by real-time PCR, and the protein expression of TLR2, TLR4, MyD88, and NF-κB in synovial tissues was determined by Western blotting. The inflammatory cells of the ankle joint and its surrounding soft tissues were observed after HE staining, and the expression of NF-κB was determined by immunohistochemistry. Compared with the MSU group, the joint swelling indexes of the luteolin group and the colchicine group were significantly decreased (P<0.05), and the levels of IL-1β, IL-6 and TNF-α were also significantly decreased (P<0.01). The mRNA levels of TLR2, TLR4, and MyD88 and the protein levels of TLR2, TLR4, MyD88, and NF-κB were significantly decreased (P<0.01). Luteolin can reduce the inflammatory response of acute gouty arthritis via down-regulating the TLR/MyD88/NF-κB pathway, and it is expected to be an effective drug for the treatment of acute gouty arthritis.

Effect of miR-223 on thrombophlebitis rats through regulating Toll-like receptor signaling pathway.

To explore the effect of the micro ribonucleic acid (miR)-223 on the thrombophlebitis rats by regulating the Toll-like receptor (TLR) signaling pathway. The rat model of thrombophlebitis was established, and miR-223 was silenced or overexpressed through lentiviral transfection. The rats were divided into miR-223 inhibitors group (Inhibitors group), miR-223 mimics group (Mimics group), and normal group (Control group). The transfection efficiency of miR-223 in venous tissues was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR), the hemorheological indexes plasma viscosity (PV) and hematocrit (HCT) were observed, and the content of the serum inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-β (TNF-β) were detected via enzyme-linked immunosorbent assay (ELISA). Moreover, the fibrinolytic indexes plasminogen activator inhibitor (PAI) and the tissue-type plasminogen activator (t-PA) were detected, the morphological changes in the venous tissues were observed via hematoxylin-eosin (HE) staining, and the gene and protein expressions of the TLR signaling pathway were detected via RT-PCR and Western blotting. The expression of miR-223 was significantly increased in the Mimics group (p<0.05) and significantly decreased in the Inhibitors group (p<0.05). The high-shear and low-shear whole blood viscosity and HCT in the Inhibitors group were significantly higher than those in the Mimics group (p<0.05). The levels of serum IL-6, IL-1β, and TNF-β in the Inhibitors group were remarkably higher than those in the Mimics group (p<0.05). The Inhibitors group had a remarkably lower level of t-PA (p<0.05) and a remarkably higher level of PAI than the Mimics group (p<0.05). Besides, the inferior vena cava wall shed and disappeared due to complete necrosis in the Inhibitors group. In the Mimics group, the vascular lumen was slightly expanded, and the vascular wall had intact contour. It was found in the gene detection that the mRNA levels of TLR2, myeloid differential protein-88 (MyD88) and c-Jun N-terminal kinase (JNK) were evidently increased in the Inhibitors group, and the significant increases in the protein levels of TLR2 and MyD88 were also observed in the protein detection. The overexpression of miR-223 can inhibit the TLR signaling pathway, thereby promoting the recovery of thrombophlebitis rats.

Particulate matters induce acute exacerbation of allergic airway inflammation via the TLR2/NF-κB/NLRP3 signaling pathway

BackgroundExposure to particulate matters (PMs) can lead to an acute exacerbation of allergic airway diseases, increasing the severity of symptoms and mortality. However, little is known about the underlying molecular mechanism. This study aimed to investigate the effects of PMs on acute exacerbation of allergic airway inflammation and seek potential therapeutic targets. MethodsNon-allergic control and ovalbumin (OVA)-allergic wide-type (WT) and Toll-like receptor 2 knockout (Tlr2-/-) mice were exposed to 100 μg of PM (diameter 5.85 μm) or saline by the oropharyngeal instillation. The responses were examined three days after exposure. In the RAW264.7 macrophage cell line, Tlr2 was knocked down by small-interfering RNA or the NF-κB inhibitor JSH-23 was used, and then the cells were stimulated with PMs for 12 h before comparison of the inflammatory responses. ResultsPM exposure led to increased inflammatory cell recruitment and airway intensity of PAS + staining in OVA-allergic WT mice, accompanied with an accumulation of inflammatory cells and elevated inflammatory cytokines, such as IL-6 and IL-18, in the bronchoalveolar lavage fluid (BALF). Furthermore, the protein levels of TLR2 and the NLRP3 inflammasome were elevated concomitantly with the airway inflammation post-OVA/PMs challenge. Tlr2 deficiency effectively inhibited the airway inflammation, including pulmonary inflammatory cell recruitment, mucus secretion, serum OVA-specific immunoglobulin E (IgE), and BALF inflammatory cytokine production. Additionally, the P-induced NLRP3 activation in the RAW 264.7 cell line was diminished by the knockdown of Tlr2 or JSH-23 treatment in vitro. ConclusionOur results indicated that PMs exacerbate the allergic airway inflammation mediated by the TLR2/ NF-κB/NLRP3 signaling pathway. Inhibition of NF-κB seems to be a possible treatment.

Abstract P2045: Genetic Disruption of Npr1 Depletes T Regulatory Cells and Provokes High Levels of Proinflammatory Cytokines and Fibrosis in the Kidneys of Female Mutant Mice

The aim of the present study was to determine the effects of gene-knockout of guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) on immunogenic responses affecting kidney function and blood pressure (BP) in Npr1 (coding for GC-A/NPRA) null mutant mice. We used female Npr1 gene-disrupted ( Npr1 -/- , 0-copy), heterozygous ( Npr1 +/- , 1-copy), wild-type ( Npr1 +/+ , 2-copy) and gene-duplicated ( Npr1 ++/++ , 4-copy) mice. Expression levels of Toll-like receptor 2/4 (TLR2/TLR4) mRNA were increased 4- to 5-fold in 1-copy mice and 6- to 10-fold in 0-copy mice; protein levels were increased 2.5- to 3-fold in 1-copy mice and 4- to 5-fold in 0-copy mice. Expression of proinflammatory cytokines and BP was significantly elevated in 1-copy and 0-copy mice compared with 2-copy and 4-copy mice. In addition, 0-copy and 1-copy mice exhibited drastic reductions in T regulatory cells (Tregs). After rapamycin treatment, Tregs were increased by 17% ( P &lt; 0.001) in 0-copy mice and 8% ( P &lt; 0.001) in 1-copy mice. Renal mRNA and protein levels of TLR2 and TLR4 were decreased by 70% in 0-copy mice and 50% in 1-copy mice. There were significantly higher levels of Tregs and very low levels of TLR2/TLR4 expression in 4-copy mice (p &lt; 0.001). These findings indicate that the disruption of Npr1 in female mice triggers renal immunogenic pathways, which transactivate the expression of proinflammatory cytokines and renal fibrosis with elevated BP in mutant animals. The data suggest that rapamycin treatment attenuates proinflammatory cytokine expression, dramatically increases anti-inflammatory cytokines, and substantially reduces BP and renal fibrosis in mutant animals.

Effects of restrictions on maternal feed intake on the immune indexes of umbilical cord blood and liver Toll-like receptor signaling pathways in fetal goats during pregnancy

BackgroundLiver has important immune function during fetal development and after birth. However, the effect of maternal malnutrition on immune function of the fetal liver is rarely reported. In this study, twelve pregnant goats (Xiangdong black goat, at d 45 of gestation) were assigned to the control group (fed 100% of nutritional requirements) and the restriction group (fed 60% of the intake of the control group) during gestation from d 55 to 100. Fetal goats were harvested at d 100 of gestation and immune indexes and amino acid profiles of the umbilical cord blood and liver Toll-like receptors (TLRs) signaling pathways were measured.ResultsMaternal body weight in the restriction group was lower than the control group (P < 0.05). Maternal feed intake restriction decreased (P < 0.05) heart weight, heart index, alkaline phosphatase and serum amyloid protein A in the umbilical cord blood (UCB). Moreover, only histidine was decreased in the restricted group (P = 0.084), and there were no differences in other amino acids contents in the UCB between the two groups (P > 0.05). The TLR2 and TLR4 mRNA expression in the fetal liver in the restriction group was greater (P < 0.05) than that in the control group. Furthermore, the mRNA expression levels of myeloid differentiation primary response 88 (MyD88), TNF receptor associated factor 6, nuclear factor kappa B subunit 1, NFKB inhibitor alpha, IFN-β, TGF-β, TNF-α and IL-1β in the restricted group were upregulated (P < 0.05), and the expression of TLR3 (P = 0.099) tended to be higher in the restricted group. However, protein levels of TLR2, TLR4, IκBα, phosphorylated IκBα, phosphorylated IκBα/total IκBα, TRIF and MyD88 were not affected (P > 0.05) by maternal intake restriction.ConclusionsThese results revealed that the restriction of maternal feed intake influenced the development of heart and hepatic protein synthesis at the acute phase of fetal goats and upregulated the mRNA expression of genes involved in MyD88-dependent signaling pathways and of target cytokines.

Genetic disruption of Npr1 depletes regulatory T cells and provokes high levels of proinflammatory cytokines and fibrosis in the kidneys of female mutant mice.

The present study was designed to determine the effects of gene knockout of guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) on immunogenic responses affecting kidney function and blood pressure (BP) in Npr1 (coding for GC-A/NPRA)-null mutant mice. We used female Npr1 gene-disrupted (Npr1-/-, 0 copy), heterozygous (Npr1+/-, 1 copy), wild-type (Npr1+/+, 2 copy), and gene-duplicated (Npr1++/++, 4 copy) mice. Expression levels of Toll-like receptor (TLR)2/TLR4 mRNA were increased 4- to 5-fold in 1-copy mice and 6- to 10-fold in 0-copy mice; protein levels were increased 2.5- to 3-fold in 1-copy mice and 4- to 5-fold in 0-copy mice. Expression of proinflammatory cytokines and BP was significantly elevated in 1-copy and 0-copy mice compared with 2-copy and 4-copy mice. In addition, 0-copy and 1-copy mice exhibited drastic reductions in regulatory T cells (Tregs). After rapamycin treatment, Tregs were increased by 17% (P < 0.001) in 0-copy mice and 8% (P < 0.001) in 1-copy mice. Renal mRNA and protein levels of TLR2 and TLR4 were decreased by 70% in 0-copy mice and 50% in 1-copy mice. There were significantly higher levels of Tregs and very low levels of TLR2/TLR4 expression in 4-copy mice (P < 0.001). These findings indicate that the disruption of Npr1 in female mice triggers renal immunogenic pathways, which transactivate the expression of proinflammatory cytokines and renal fibrosis with elevated BP in mutant animals. The data suggest that rapamycin treatment attenuates proinflammatory cytokine expression, dramatically increases anti-inflammatory cytokines, and substantially reduces BP and renal fibrosis in mutant animals.

The expression and localization of Toll-like receptors 2, 4, 5 and 9 in the epididymis and vas deferens of a adult tom cats

Toll-like receptors (TLRs) are important molecules, which provide protection against infections of the reproductive tract. This study demonstrates for the first time the expression and localization patterns of TLRs in the caput, corpus and cauda segments of the epididymal duct (ED) and the vas deferens (VD) of adult domestic cats using immunohistochemistry and western blotting. While immunoblot analyses revealed relatively similar protein levels for TLRs 2, 4, 5, and 9 in three segments of the ED, the protein levels of TLR2 and TLR4 in the VD were found to be significantly higher than those measured in the ED segments (P < 0.05). On the other hand, immunostaining showed that TLRs exhibited regional- and cell-specific localization patterns. TLR2 and TLR5 were immunolocalized to the nucleus and cytoplasm of the principal cells in all ducts. TLR4 was restricted to the stereocilia, and TLR9 was located in the cytoplasm of the principal cells. Narrow cells displayed positive immunoreactions for TLR4 and TLR5. The basal cells of the different ED segments were positive for all four TLRs. TLR2, TLR5 and TLR9 were detected in the cytoplasmic droplets of the spermatozoa. TLR4 and TLR9 were detected along the entire length of the sperm tail, whilst TLR2 and TLR5 were absent in the midpiece. TLR2 and TLR5 were also detected in the equatorial segment of the sperm head. These results suggest that TLR2, TLR4, TLR5 and TLR9 are important not only for the protection of the ED, VD and spermatozoa but also for the maturation and storage of spermatozoa in the ED and VD, respectively.

Regular Practice of Moderate Physical Activity by Older Adults Ameliorates Their Anti-Inflammatory Status.

A chronic inflammatory state is a major characteristic of the aging process, and physical activity is proposed as a key component for healthy aging. Our aim was to evaluate the body composition, hypertension, lipid profile, and inflammatory status of older adults, and these factors’ association with physical activity. A total of 116 elderly volunteers were categorized into terciles of quantitative metabolic equivalents of task (MET). Subjects in the first and third terciles were defined as sedentary and active subjects, respectively. Anthropometric and biochemical parameters, hemograms, and inflammatory markers were measured in plasma or peripheral mononuclear blood cells (PBMCs). The active groups exercised more than their sedentary counterparts. The practice of physical activity was accompanied by lower weight, fat mass, body mass index, and diastolic blood pressure when compared to a more sedentary life-style. Physical activity also lowered the haematocrit and total leukocyte, neutrophil, and lymphocyte counts. The practice of exercise induced a decrease in the IL-6 circulating levels and the TLR2 protein levels in PBMCs, while the expression of the anti-inflammatory IL-10 was activated in active subjects. The regular practice of physical activity exerts beneficial effects on body composition and the anti-inflammatory status of old people.

Molecular Mechanism of the Protective Effect of Zerumbone on Lipopolysaccharide-Induced Inflammation of THP-1 Cell-Derived Macrophages

Unregulated inflammatory responses lead to massive production of macrophages-activating inflammatory cytokines and chemokines, which may induce diabetes, cancer, and atherosclerosis. Macrophages differentiated from human monocyte (THP-1) have been extensively used in in vitro inflammation models in recent studies. Zerumbone is a major component of the essential oil of Zingiber zerumbet Smith, a type of wild ginger. In this study, we investigated the effects of zerumbone on the secretion of pro-inflammatory cytokines and its underlying mechanistic regulation in lipopolysaccharide (LPS)-activated inflammation of THP-1 cell-derived macrophages. Nuclear factor (NF)-κB and toll-like receptors (TLRs) are known to play important roles in inflammation and immunity. If pathogens enter the host, TLRs recognize the pathogens and signal for the activation of NF-κB to induce inflammatory gene products, such as cytokines. We demonstrated that zerumbone inhibits the secretion of pro-inflammatory cytokines and the induction of NF-κB p65 in LPS-activated inflammation of THP-1 cell-derived macrophages. In addition, zerumbone significantly inhibited mRNA and protein levels of TLR-2/4, and the expression of myeloid differentiation factor 88 (MyD88) adaptor proteins in the LPS-activated inflammation of THP-1 cell-derived macrophages. Moreover, we showed that zerumbone (1-10 μM) regulated histone deacetylase (HDAC) activity and the expression of HDAC genes. H3K9ac, H3K27ac, and H3K4me2 are inducible histone marks that activate gene expression. Treatment with LPS upregulated H3K9ac, H3K27ac, and H3K4me2 in THP-1 cell-derived macrophages; however, this upregulation was decreased by zerumbone treatment. Therefore, these results provide evidence that zerumbone may have therapeutic benefits for chronic inflammatory diseases.

Uric acid up-regulates renin-angiotensin system via TLR2 inflammatory signaling pathway in adipocytes

Objective To study the underlying mechanisms through which uric acid upregulates local renin-angiotensin system in adipocytes. Methods The primary cultured rat adipocytes were administered with 0, 1, 5, 10, and 15 mg/dl uric acid for 0, 12, 24, 48, and 72 h. Some of the pre-adipocytes were infected with siRNA-TLR2 or its negative control before differentiation. Then infected mature adipocytes were treated with 10 mg/dl uric acid for 48 h. After that procedure, mRNA levels of TLR2, TNF-α, IL-6, MCP-1, AGT, ACE1, AT1R, and AT2R were detected with real-time PCR method. The protein levels of TLR2 and NF-κB were detected by Western blotting. The concentrations of angiotensinⅡ(Ang Ⅱ) in the conditioned medium or cell lysate were measured using ELISA method. Results The mRNA levels mRNA of TLR2 increased in parallel with uric acid concentration. Moreover, it also increased with the time. By contrast, TLR2 mRNA expression decreased at 72 h. Uric acid increased levels of TNF-α, IL-6, and MCP-1 in adipocytes. It was also found that uric acid upregulated RAS components, including AGT, ACE1, AT1R, AT2R, and AngⅡ. However, siRNA-TLR2 infection significantly reduced the levels of TLR2 and NF-κB. As a result, both inflammatory cytokines and RAS components were significantly decreased in adipocytes. Conclusion Uric acid up-regulates RAS expression partially via TLR2 inflammatory signaling pathway in adipocytes. (Chin J Endocrinol Metab, 2018, 34: 684-689) Key words: Uric acid; Toll-like receptor 2; Inflammation; Adipocyte; Renin-angiotensin system

α-Synuclein activates innate immunity but suppresses interferon-γ expression in murine astrocytes.

Glial activation and neuroinflammation contribute to pathogenesis of neurodegenerative diseases, linked to neuron loss and dysfunction. α-Synuclein (α-syn), as a metabolite of neuron, can induce microglia activation to trigger innate immune response. However, whether α-syn, as well as its mutants (A53T, A30P, and E46K), induces astrocyte activation and inflammatory response is not fully elucidated. In this study, we used A53T mutant and wild-type α-syns to stimulate primary astrocytes in dose- and time-dependent manners (0.5, 2, 8, and 20μg/ml for 24hr or 3, 12, 24, and 48hr at 2μg/ml), and evaluated activation of several canonical inflammatory pathway components. The results showed that A53T mutant or wild-type α-syn significantly upregulated mRNA expression of toll-like receptor (TLR)2, TLR3, nuclear factor-κB and interleukin (IL)-1β, displaying a pattern of positive dose-effect correlation or negative time-effect correlation. Such upregulation was confirmed at protein levels of TLR2 (at 20μg/ml), TLR3 (at most doses), and IL-1β (at 3hr) by western blotting. Blockage of TLR2 other than TLR4 inhibited TLR3 and IL-1β mRNA expressions. By contrast, interferon (IFN)-γ was significantly downregulated at mRNA, protein, and protein release levels, especially at high concentrations of α-syns or early time-points. These findings indicate that α-syn was a TLRs-mediated immunogenic agent (A53T mutant stronger than wild-type α-syn). The stimulation patterns suggest that persistent release and accumulation of α-syn is required for the maintenance of innate immunity activation, and IFN-γ expression inhibition by α-syn suggests a novel immune molecule interaction mechanism underlying pathogenesis of neurodegenerative diseases.

Abstract 4637: Activation of toll-like receptor-2 promotes proliferation in human lung adenocarcinoma cells

Abstract Objective: Toll-like receptors (TLR) have been implicated in tumor progression by affecting the immune response in the tumor microenvironment. Toll like receptors have been described to be present in human cancer cells but the presence and the role of these receptors in the growth and proliferation of human lung cancer cells is not known. We analyzed human lung cancer cells for the presence of TLR-2 receptors and evaluated the proliferation response to a specific TLR-2 agonist. Methods: Human non-small cell cancer cell (NSCLC) lines A549, (adenocarcinoma) H125 adenosquamous, and H1650 adenocarcinoma (American Type Culture Collection), were cultured using standard techniques. Cells were treated with Pam3CSK4, a specific agonist of TLR2, at doses of 0ug/ml, 5ug/ml, and 10ug/ml for 72 hours. Baseline protein levels of TLR2 were assessed using standard western blotting techniques. Proliferation assays were completed using the MTS assay in response to treatment with the agonist Results: Protein analysis demonstrated varying but consistently detectable levels of TLR2 protein in each cell line. After treatment with Pam3CSK4 we found that proliferation was significantly promoted in the human lung adenocarcinoma cell lines (p=.03), but not in the adenosquamous cell line (p=0.001). Conclusion: Toll-like receptor -2 is consistently present and detectable on human lung adenocarcinoma cells. Toll Like receptor -2 activation results in increased proliferation in human lung adenocarcinoma cells and this effect appears to be specific to adenocarcinoma cells. Further study is necessary to elucidate the downstream pathways responsible for the increased proliferation we see in these human lung adenocarcinoma cells, however these findings may suggest TLR-2 to be a possible therapeutic target in human lung cancer. Citation Format: Patrick Kohtz. Activation of toll-like receptor-2 promotes proliferation in human lung adenocarcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4637. doi:10.1158/1538-7445.AM2017-4637

Hepatitis B Surface Antigen Promotes the Invasion of Hepatitis B Virus-Related Hepatocellular Carcinoma Cells by Upregulation of Toll-Like Receptor 2.

Hepatitis B virus (HBV) infection is one of the major risk factors leading to the development of hepatocellular carcinoma (HCC). Hepatitis B surface antigen (HBsAg) plays a pivotal role in HBV-related HCC pathogenesis, and Toll-like receptor (TLR) 2 is also considered to mediate tumor progression. However, the interaction between HBsAg and TLR2 in HCC progression remains unclear. Thus, the aim of the study was to explore the effect of HBsAg-TLR2 pathway on growth and invasion of HBV-related HCC cells and examine the potential mechanisms been involved. The expression of TLR2 was measured in two different HCC cell lines (HepG2 and HepG2.2.15) with or without recombinant HBsAg by real-time reverse polymerase chain reaction and Western blot. Cellular proliferation, invasion, cytokine productions, and downstream signaling pathways were also measured in TLR2-silencing HepG2.2.15 cells in response to HBsAg stimulation. The mRNA and protein levels of TLR2 were significantly elevated in HepG2.2.15 cells than those in HepG2 cells. HBsAg simulation increased proinflammatory cytokine production and invasion of HepG2.2.15 cells, while this process was inhibited by TLR2 silence. However, TLR2 siRNA transfection alone did not affect the bioactivities of tumor cells. Moreover, HBsAg increased expression of MyD88 and phosphorylation of NF-κB p50 and p38MAPK. Downregulation of TLR2 inhibited HBsAg-induced MyD88 and p-NF-κB, but not p-p38MAPK in HepG2.2.15 cells. In conclusion, HBsAg stimulation promotes the invasion of HBV-related HCC cells. TLR2/MyD88/NF-κB signaling pathway may be involved in this procession by upregulation of cytokine production. The interaction between TLR2 and HBsAg may contribute to the poor prognosis of HBV-related HCC.

Chitin-Induced Airway Epithelial Cell Innate Immune Responses Are Inhibited by Carvacrol/Thymol.

Chitin is produced in large amounts by fungi, insects, and other organisms and has been implicated in the pathogenesis of asthma. Airway epithelial cells are in direct contact with environmental particles and serve as the first line of defense against inhaled allergens and pathogens. The potential contributions of airway epithelial cells to chitin-induced asthma remain poorly understood. We hypothesized that chitin directly stimulates airway epithelial cells to release cytokines that promote type 2 immune responses and to induce expression of molecules which are important in innate immune responses. We found that chitin exposure rapidly induced the expression of three key type 2-promoting cytokines, IL-25, IL-33 and TSLP, in BEAS-2B transformed human bronchial epithelial cells and in A549 and H292 lung carcinoma cells. Chitin also induced the expression of the key pattern recognition receptors TLR2 and TLR4. Chitin induced the expression of miR-155, miR-146a and miR-21, each of which is known to up-regulate the expression of pro-inflammatory cytokines. Also the expression of SOCS1 and SHIP1 which are known targets of miR-155 was repressed by chitin treatment. The monoterpene phenol carvacrol (Car) and its isomer thymol (Thy) are found in herbal essential oils and have been shown to inhibit allergic inflammation in asthma models. We found that Car/Thy inhibited the effects of chitin on type 2-promoting cytokine release and on the expression of TLRs, SOCS1, SHIP1, and miRNAs. Car/Thy could also efficiently reduce the protein levels of TLR4, inhibit the increase in TLR2 protein levels in chitin plus Car/Thy-treated cells and increase the protein levels of SHIP1 and SOCS1, which are negative regulators of TLR-mediated inflammatory responses. We conclude that direct effects of chitin on airway epithelial cells are likely to contribute to allergic airway diseases like asthma, and that Car/Thy directly inhibits epithelial cell pro-inflammatory responses to chitin.

Toll-like receptor (TLR)-2/4 expression in retinal ganglion cells in a high-glucose environment and its implications.

Diabetic retinopathy (DR), a major complication of diabetes mellitus, is the leading cause of adult blindness. The Toll-like receptor (TLR) family is believed to be involved in the pathogenesis and progression of DR. Here, we investigated the expression profiles of TLR-2 and TLR-4 in retinal ganglion cells (RGCs), in an attempt to elucidate the role of these molecules in the etiology of DR. In vitro cultured RGCs were divided into control and high-glucose groups. The mRNA and protein levels of TLR-2, TLR-4, and nuclear factor (NF)-κB were detected by real-time PCR and western blotting. RGCs were further transfected with specific siRNA targeting TLR2/TLR4; the proliferation of transfected RGCs and their tumor necrosis factor (TNF)-α and interleukin (IL)-8 secretory capacity were analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and enzyme-linked immunosorbent assays (ELISA), respectively. In a high-glucose environment, TLR-2/4 expression was significantly upregulated in RGCs (while their viability decreased); additionally, NF-κB expression and secretion of TNF-α and IL-8 were significantly increased. Co-silencing of the TLR-2 and TLR-4 genes inhibited NF- κB expression and TNF-α/IL-8 secretion, while increasing the survival rate of RGCs. Therefore, a high-glucose environment can potentiate the expression of TLR-2 and TLR-4 in RGCs, activate the downstream signaling pathway, and increase the secretion of pro-inflammatory factors, thereby aggravating DR.

Blockade of Toll-Like Receptors (TLR2, TLR4) Attenuates Pain and Potentiates Buprenorphine Analgesia in a Rat Neuropathic Pain Model.

Accumulating evidence indicates that microglial TLR2 and TLR4 play a significant role in nociception. Experiments were conducted to evaluate the contribution of TLR2 and TLR4 and their adaptor molecules to neuropathy and their ability to amplify opioid effectiveness. Behavioral tests (von Frey's and cold plate) and biochemical (Western blot and qRT-PCR) analysis of spinal cord and DRG tissue were conducted after chronic constriction injury (CCI) to the sciatic nerve. Repeated intrathecal administration of LPS-RS (TLR2 and TLR4 antagonist) and LPS-RS Ultrapure (TLR4 antagonist) attenuated allodynia and hyperalgesia. Biochemical analysis revealed time-dependent upregulation of mRNA and/or protein levels of TLR2 and TLR4 and MyD88 and TRIF adaptor molecules, which was paralleled by an increase in IBA-1/CD40-positive cells under neuropathy. LPS-RS and LPS-RS Ultrapure similarly influenced opioid analgesia by enhancing the effectiveness of buprenorphine but not morphine. Summing up, in light of their upregulation over the course of pain, both TLR2 and TLR4 may indeed play a significant role in neuropathy, which could be linked to the observed activation of IBA-1/CD40-positive cells. Blockade of TLR2 and TLR4 produced analgesia and enhanced buprenorphine's effectiveness, which suggests that they may be a putative target for future pharmacological pain relief tools, especially for opioid rotation, when the effect of morphine is tolerated.