Human Rhinovirus-induced Proinflammatory Cytokine and Interferon-β Responses in Nasal Epithelial Cells From Chronic Rhinosinusitis Patients

Purpose

Asthma exacerbation from human rhinovirus (HRV) infection is associated with deficient antiviral interferon (IFN) secretion. Although chronic rhinosinusitis (CRS), an inflammatory upper airway disease, is closely linked to asthma, IFN-β responses to HRV infections in human nasal epithelial cells (HNECs) from CRS patients remain to be studied. We evaluated inflammatory and antiviral responses to HRV infection in HNECs from CRS patients.

Methods

HNECs, isolated from turbinate tissue of 13 patients with CRS and 14 non-CRS controls, were infected with HRV16 for 4 hours. The HRV titer, LDH activity, production of proinflammatory cytokines and IFN-β proteins, and expression levels of RIG-I and MDA5 mRNA were assessed at 8, 24, and 48 hours after HRV16 infection.

Results

The reduction in viral titer was slightly delayed in the CRS group compared to the non-CRS control group. IL-6 and IL-8 were significantly increased to a similar extent in both groups after HRV infection. In the control group, IFN-β production and MDA5 mRNA expression were significantly increased at 8 and 24 hours after HRV16 infection, respectively. By contrast, in the CRS group, IFN-β was not induced by HRV infection; however, HRV-induced MDA5 mRNA expression was increased, but the increase was slightly delayed compared to the non-CRS control group. The RIG-I mRNA level was not significantly increased by HRV16 infection in either group.

Conclusions

HRV-induced secretion of proinflammatory cytokines in CRS patients was not different from that in the non-CRS controls. However, reductions in viral titer, IFN-β secretion, and MDA5 mRNA expression in response to HRV infection in CRS patients were slightly impaired compared to those in the controls, suggesting that HRV clearance in CRS patients might be slightly deficient.     

Mycoplasma genitalium-Derived Lipid-Associated Membrane Proteins Activate NF-κB through Toll-Like Receptors 1, 2, and 6 and CD14 in a MyD88-Dependent Pathway

Mycoplasma genitalium is a leading pathogen of nongonoccocal chlamydia-negative urethritis, which has been implicated directly in numerous other genitourinary and extragenitourinary tract pathologies. The pathogenesis of infection is attributed in part to excessive immune responses. M. genitalium-derived lipid-associated membrane proteins (LAMPs) are a mixture of bacterial lipoproteins, exposed at the surface of mycoplasma, that are potent inducers of the host innate immune system. However, the interaction of M. genitalium-derived LAMPs as pathogenic agents with Toll-like receptors (TLRs) and the signaling pathways responsible for active inflammation and NF-κB activation have not been fully elucidated. In this study, LAMPs induced the production of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in a dose-dependent manner. Blocking assays showed that TLR2- and CD14-neutralizing antibodies reduced the expression of TNF-α and IL-6 in THP-1 cells. Furthermore, LAMP-induced NF-κB activation was increased in 293T cells transfected with TLR2 plasmid. The activity of NF-κB was synergically augmented by cotransfected TLR1, TLR6, and CD14. Additionally, LAMPs were shown to inhibit NF-κB expression by cotransfection with dominant-negative MyD88 and TLR2 plasmids. These results suggest that M. genitalium-derived LAMPs activate NF-κB via TLR1, TLR2, TLR6, and CD14 in a MyD88-dependent pathway.Mycoplasmas are the smallest of the known self-replicating parasitic microorganisms, and they lack a cell wall in cell-free medium. They are pervasive in nature, humans, and animals, but most mycoplasmas are nonpathogenic to the host (36). Lipid-associated membrane proteins (LAMPs) are a mixture of bacterial lipoproteins that are expressed on the surface, and they are the main structures of interaction with the host cells (37). They have been demonstrated to be biologically active and are the most potent initiator of inflammatory reactions in mycoplasma infection (9, 11, 34). Since Mycoplasma genitalium was first isolated from humans in 1981 (51), it has been considered an important pathogen that could emerge in sexually transmitted diseases, including acute endometritis, salpingitis, mucopurulent cervicitis, tubal factor infertility, and pelvic inflammatory disease, as well as a range of other pathologies, such as arthritis, AIDS progression, chronic fatigue, and autoimmune disorders (4, 10, 19). Recent evidence has demonstrated that M. pneumoniae-derived LAMPs can induce NF-κB activation in human acute monocytic leukemia cell lines (THP-1 cells) (42, 43).Toll-like receptors (TLRs) play an essential role in initiating the inflammatory reactions, such as NF-κB activation (2, 22, 26). To date, 13 types of human TLRs have been identified and shown to be critical for signaling transduction in response to a number of pathogen-associated molecular patterns (PAMPs) (8, 44). PAMPs are recognized by different TLRs to form heteromeric complexes, among which the family of TLRs prominently features, for the cell to distinguish successfully among different pathogens. Among TLRs, TLR2, in tandem with TLR1 or TLR6, has been identified as a receptor that is important to the innate immune response against several gram-positive bacteria and for cellular signaling by components of gram-positive bacteria, such as peptidoglycan, lipoteichoic acid, and lipoproteins. The receptors transmit signaling pathways via interleukin-1R (IL-1R)-associated signal molecules, including myeloid differentiation factor 88 (MyD88), IL-1R-activated kinase, tumor necrosis factor (TNF) receptor-associated factor 6, and mitogen-activated protein kinases, leading to the activation of NF-κB and activating protein 1 (AP-1), which in turn triggers the expression of many proinflammatory cytokines, such as TNF-α, IL-1β, IL-6, and IL-8 (1, 20, 29, 47). MyD88 serves as the essential adaptor for other IL-1/TLR family members, including IL-1R and IL-18R. The activation of the intracellular pathway through MyD88 results in the activation of NF-κB. CD14 is a glycosylphosphatidylinositol surface-anchored molecule expressed in many kinds of cells as another accessory receptor of TLR2. It lacks an intracellular segment and functions as a coreceptor for numerous bacterial products, including peptidoglycan, lipopolysaccharide (LPS), and bacterial lipoproteins, thereby facilitating signaling through other receptors (23). Several studies have suggested that TLR2 functions as a signaling receptor for LPS in the presence of CD14 (50). Recently published data support the possibility that the multifunctional B class scavenger receptor CD36 also is involved in TLR2 transmembrane signal transducing (16). However, data available also have underscored the current lack of a complete understanding of the molecular mechanisms that link M. genitalium infection to the activation of the innate immune system, which is essential to the induction of the inflammation.The LAMPs from Mycoplasma fermentans and Mycoplasma penetrans activate human immunodeficiency virus long terminal repeats through TLRs (41). To further understand how LAMPs activate the immune system of the cell, including THP-1 cells and human embryonic kidney cells (HEK293T cells), the present study was designed to investigate the interaction of M. genitalium-derived LAMPs with TLRs and CD14 and to clarify the role of MyD88 in activating the NF-κB signaling pathway.     

Bacterial Siderophores That Evade or Overwhelm Lipocalin 2 Induce Hypoxia Inducible Factor 1α and Proinflammatory Cytokine Secretion in Cultured Respiratory Epithelial Cells

Iron is essential for many cellular processes and is required by bacteria for replication. To acquire iron from the host, pathogenic Gram-negative bacteria secrete siderophores, including enterobactin (Ent). However, Ent is bound by the host protein lipocalin 2 (Lcn2), preventing bacterial reuptake of aferric or ferric Ent. Furthermore, the combination of Ent and Lcn2 (Ent+Lcn2) leads to enhanced secretion of interleukin-8 (IL-8) compared to that induced by either stimulus alone. Modified or structurally distinct siderophores, including yersiniabactin (Ybt) and glycosylated Ent (GlyEnt, or salmochelin), deliver iron to bacteria despite the presence of Lcn2. We hypothesized that the robust immune response to Ent and Lcn2 requires iron chelation rather than the Ent+Lcn2 complex itself and also can be stimulated by Lcn2-evasive siderophores. To test this hypothesis, cultured respiratory epithelial cells were stimulated with combinations of purified siderophores and Lcn2 and analyzed by gene expression microarrays, quantitative PCR, and cytokine immunoassays. Ent caused HIF-1α protein stabilization, induced the expression of genes regulated by hypoxia-inducible factor 1α (HIF-1α), and repressed genes involved in cell cycle and DNA replication, whereas Lcn2 induced expression of proinflammatory cytokines. Iron chelation by excess Ent or Ybt significantly increased Lcn2-induced secretion of IL-8, IL-6, and CCL20. Stabilization of HIF-1α was sufficient to enhance Lcn2-induced IL-6 secretion. These data indicate that respiratory epithelial cells can respond to bacterial siderophores that evade or overwhelm Lcn2 binding by increasing proinflammatory cytokine production.     

Stevioside Suppressed Inflammatory Cytokine Secretion by Downregulation of NF-κB and MAPK Signaling Pathways in LPS-Stimulated RAW264.7 Cells

Stevioside, a diterpene glycoside isolated from Stevia rebaudiana, has been reported to have anti-inflammatory properties. However, the underlying molecular mechanisms are not well understood. The objective of this study was to investigate the molecular mechanism of stevioside in modifying lipopolysaccharide (LPS)-induced signal pathways in RAW264.7 cells. RAW264.7 cells were stimulated with LPS in the presence or absence of stevioside. The expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction. Nuclear factor-κB (NF-κB), inhibitory kappa B (IκBα) protein, p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) were determined by western blot. The results showed that stevioside dose-dependently inhibited the expression of tumor necrosis factor-α, interleukin-6, and interleukin-1β in LPS-stimulated RAW264.7 cells. Western blot analysis showed that stevioside suppressed LPS-induced NF-κB activation, IκBa degradation, phosphorylation of ERK, JNK, and P38. Our results suggest that stevioside exerts an anti-inflammatory property by inhibiting the activation of NF-κB and mitogen-activated protein kinase signaling and the release of proinflammatory cytokines. These findings suggest that stevioside may be a therapeutic agent against inflammatory diseases.     

Thrombospondin-1 Production Regulates the Inflammatory Cytokine Secretion in THP-1 Cells Through NF-κB Signaling Pathway

Thrombospondin-1 (TSP-1) is upregulated in several inflammatory diseases. Recent data have shown that macrophages from TSP-1-deficient mice have a reduced inflammatory phenotype, suggesting that TSP-1 plays a part in macrophage activation. DNA microarray approach revealed that Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) may induce the enhanced TSP-1 expression in human monocytes, suggesting a role of TSP-1-mediated pathogenesis in periodontitis. Until recently, the function of TSP-1 has been a matter of debate. In this study, we explored the role of TSP-1 in inflammatory cytokine secretions and its putative mechanism in pathogenesis of periodontitis. We demonstrated that TSP-1 expression was significantly upregulated in gingival tissues with periodontitis and in P. gingivalis LPS-stimulated THP-1 cells. Deficiency of TSP-1 by transfecting siRNAs decreased IL-6, IL-1β, and TNF-α secretions in THP-1 cells, whereas overexpression of TSP-1 resulted in an upregulation of IL-6, IL-1β, and TNF-α productions. Additional experiments showed that Pyrrolidine dithiocarbamate (PDTC) inhibited IL-6, IL-1β, and TNF-α expression induced by overexpression of TSP-1, accompanying with downregulation of phosphorylated p65 and IκBα protein levels in response to P. gingivalis LPS. These results indicated that TSP-1 played a significant role in P. gingivalis LPS-initiated inflammatory cytokines (IL-6, IL-1β, and TNF-α) secretions of THP-1 cells, and the NF-κB signaling is involved in its induction of expression. Thus, TSP-1 effectively elevated P. gingivalis LPS-induced inflammation mediated by the NF-κB pathway and may be critical for pathology of periodontitis.     

Lactobacillus acidophilus Induces Cytokine and Chemokine Production via NF-��B and p38 Mitogen-Activated Protein Kinase Signaling Pathways in Intestinal Epithelial Cells

Intestinal epithelial cells can respond to certain bacteria by producing an array of cytokines and chemokines which are associated with host immune responses. Lactobacillus acidophilus NCFM is a characterized probiotic, originally isolated from human feces. This study aimed to test the ability of L. acidophilus NCFM to stimulate cytokine and chemokine production in intestinal epithelial cells and to elucidate the mechanisms involved in their upregulation. In experiments using intestinal epithelial cell lines and mouse models, we observed that L. acidophilus NCFM could rapidly but transiently upregulate a number of effector genes encoding cytokines and chemokines such as interleukin 1α (IL-1α), IL-1β, CCL2, and CCL20 and that cytokines showed lower expression levels with L. acidophilus NCFM treatment than chemokines. Moreover, L. acidophilus NCFM could activate a pathogen-associated molecular pattern receptor, Toll-like receptor 2 (TLR2), in intestinal epithelial cell lines. The phosphorylation of NF-κB p65 and p38 mitogen-activated protein kinase (MAPK) in intestinal epithelial cell lines was also enhanced by L. acidophilus NCFM. Furthermore, inhibitors of NF-κB (pyrrolidine dithiocarbamate [PDTC]) and p38 MAPK (SB203580) significantly reduced cytokine and chemokine production in the intestinal epithelial cell lines stimulated by L. acidophilus NCFM, suggesting that both NF-κB and p38 MAPK signaling pathways were important for the production of cytokines and chemokines induced by L. acidophilus NCFM.     

Prolonged NF-κB Activation by a Macrophage Inhibitory Cytokine 1-Linked Signal in Enteropathogenic Escherichia coli-Infected Epithelial Cells

Intestinal epithelial activation of nuclear factor kappa B (NF-κB) exerts both detrimental and beneficial functions in response to various luminal insults, including ones associated with mucosa-associated pathogens. Gastrointestinal infection with enteropathogenic Escherichia coli (EPEC) causes severe injuries in epithelial integrity and leads to watery diarrhea. The present study was conducted to investigate the prolonged epithelial responses to persistent EPEC infection via NF-κB activation. EPEC infection led to sustained activation of NF-κB signal in mouse intestinal epithelial cells in vivo and in vitro, which was positively associated with a type III secretion system, whereas early NF-κB is regulated. Moreover, prolonged NF-κB activation was found to be a part of macrophage inhibitory cytokine 1 (MIC-1)-mediated signaling activation, a novel link between NF-κB signaling and infection-associated epithelial stress. EPEC infection induced gene expression of MIC-1, a member of the transforming growth factor β (TGF-β) superfamily, which then activated TGF-β-activated kinase 1 and consequently led to NF-κB activation. Functionally, both EPEC-induced MIC-1 and NF-κB signaling mediated epithelial survival by enhancing the expression of cyclin D1, a target of NF-κB. In summary, the results of the present study suggest that MIC-1 serves as a mediator of prolonged NF-κB activation, which is critical in maintaining gut epithelial integrity in response to infection-induced injuries.     

Thymol Inhibits LPS-Stimulated Inflammatory Response via Down-Regulation of NF-κB and MAPK Signaling Pathways in Mouse Mammary Epithelial Cells

Thymol is a natural monoterpene phenol primarily found in thyme, oregano, and tangerine peel. It has been shown to possess anti-inflammatory property both in vivo and in vitro. In the present paper, we studied the anti-inflammatory effect of thymol in lipopolysaccharide (LPS)-stimulated mouse mammary epithelial cells (mMECs). The mMECs were stimulated with LPS in the presence or absence of thymol (10, 20, 40 μg/mL). The concentrations of tumor necrosis factor α (TNF-α), interleukin (IL)-6, and IL-1β in the supernatants of culture were determined using enzyme-linked immunosorbent assay. Cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), nuclear factor-κB (NF-κB), and inhibitor protein of NF-κB (IκBα) were measured using western blot. The results showed that thymol markedly inhibited the production of TNF-α and IL-6 in LPS-stimulated mMECs. The expression of iNOS and COX-2 was also suppressed by thymol in a dose-dependent manner. Furthermore, thymol blocked the phosphorylation of IκBα, NF-κB p65, ERK, JNK, and p38 mitogen-activated protein kinases (MAPKs) in LPS-stimulated mMECs. These results indicate that thymol exerted anti-inflammatory property in LPS-stimulated mMECs by interfering the activation of NF-κB and MAPK signaling pathways. Thereby, thymol may be a potential therapeutic agent against mastitis.     

Saturated Fatty Acids Up-regulate COX-2 Expression in Prostate Epithelial Cells via Toll-like Receptor 4/NF-κB Signaling

Cyclooxygenase-2 (COX-2) has been implicated in prostate carcinogenesis, and recently it has been confirmed to be a molecular target of saturated fatty acids (SFAs). In the present study, we investigated the effect of stearic acid (SA) and palmitic acid (PA), two of the most abundant SFAs contained in dietary fat, on COX-2 expression in prostate epithelial cells and the signaling transduction pathway involved. First, we demonstrated that both SA and PA increased the mRNA and protein expression of COX-2, and consistently induced the activation of NF-κB in RWPE-1, BPH-1 and PC-3 prostate epithelial cell lines. The effect of SA and PA on COX-2 over-expression and NF-κB activation was in a dose-dependent manner, and PA was more potent than SA at the same concentration. Then, we demonstrated inhibition of NF-κB using its specific inhibitor strikingly attenuated PA-induced COX-2 expression. Toll-like receptor 4 (TLR4) was revealed to be expressed on RWPE-1, BPH-1 and PC-3 cell lines by PCR and immunofluorescence staining, and blocking its signaling significantly inhibited PA induced COX-2 over-expression and NF-κB activation. Taken together, we demonstrated that SFAs can up-regulate COX-2 expression in prostate epithelial cells, and this effect was mediated mainly through the TLR4/NF-κB signaling pathway.     

Magnolol Inhibits Tumor Necrosis Factor-α-Induced ICAM-1 Expression via Suppressing NF-κB And MAPK Signaling Pathways in Human Lung Epithelial Cells

Magnolol is a traditional Chinese medicine from the root and bark of Magnolia officinalis. It has long been used to treat anxiety, cough, headache and allergies, as well as a variety of inflammations. Lung inflammation is a key event in the pathogenesis of asthma and chronic obstructive pulmonary disease. The present study sought to examine the effects of magnolol on tumor necrosis factor (TNF)-α-induced upregulation of intercellular adhesion molecule-1 (ICAM-1), activation of the nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathway in cultured human pulmonary epithelial cells, and adhesion of human macrophage-like U937 cells to A549 cells. A549 cells were incubated with magnolol at 25 and 50 μmol/l. Then, 20 ng/ml TNF-α was used to activate the cells. Magnolol inhibited the growth of human pulmonary epithelial A549 cells in a dose- and time-dependent manner. Magnolol suppressed the adhesion of U937 cells to TNF-α-induced A549 cells. In cultured human pulmonary epithelial A549 cells, magnolol decreased TNF-α-induced upregulation of ICAM-1. Magnolol repressed TNF-α-induced activation of NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways in A549 cells by inhibiting phosphorylation of NF-κB, p38, extracellular signal-regulated kinase (ERK) 1/2, and stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK). These findings support the hypothesis that magnolol inhibits the inflammatory process in lung epithelial A549 cells by suppressing the ICAM-1 and NF-κB and MAPK signaling pathways. Taken together, these results indicate that magnolol offers significant potential as a therapeutic treatment for inflammatory diseases of the lungs including asthma, sepsis, and chronic obstructive pulmonary disease.     

NF-κB Decoy Oligonucleotides Suppress RANTES Expression and Monocyte Chemotactic Activity via NF-κB Inactivation in Stromal Cells of Ectopic Endometrium

Background  The nuclear factor kappa B (NF-κB) pathway is a critical mediator of regulated on activation, normal T cell expressed and secreted (RANTES) gene regulation and therefore represents a potential target for therapy of endometriosis-associated symptoms. Objective  The objective of this study was to investigate the effect of NF-κB decoy oligonucleotides (ODNs) on NF-κB activation, RANTES expression, and monocyte chemotactic activity in ectopic endometrial stromal cells in vitro. Methods  A specific sandwich enzyme-linked immunosorbent assay (ELISA) was used to quantify RANTES expression in ectopic and normal endometrial stromal cells stimulated by interleukin (IL)-1β. Four hours after transfection of NF-κB decoy ODNs, 10 ng/ml IL-1β was added to induce the ectopic endometrial stromal cells to secrete RANTES. The NF-κB activation, RANTES expression, and monocyte chemotactic activity in ectopic endometrial stromal cells were respectively evaluated by electrophoretic mobility shift assay, ELISA, and Boyden chambers. Results  IL-1β induced significantly higher levels (P < 0.05) of RANTES expression in a time-dependent manner in ectopic endometrial stromal cells compared with IL-1β-untreated ectopic and normal endometrial stromal cells. The RANTES accounts for the majority (68%) of the monocyte chemotactic activity in conditioned media of ectopic endometrial stromal cells. In vitro transfection of NF-κB decoy ODNs dramatically decreased (P < 0.05) the NF-κB activation, RANTES expression, and monocyte chemotactic activity in IL-1β-induced ectopic endometrial stromal cells. Conclusions  NF-κB decoy ODNs may exert anti-inflammatory effects in ectopic endometrial stromal cells via the suppression of NF-κB activation, RANTES expression, and monocyte chemotactic activity.     

Toll-Like Receptors Expression and NF-κB Activation in Peritoneal Leukocytes in Morphine-Mediated Impairment of Zymosan-Induced Peritonitis in Swiss Mice

Zymosan-induced peritonitis represents a well-described model of acute inflammation. The binding of zymosan with its specific Toll-like receptors (TLR2 and TLR6) on leukocytes initiates activation and phosphorylation of nuclear factor (NF)-κB, which leads to accumulation of NF-κB p65 subunits in the nucleus and subsequently up-regulation of the proinflammatory cytokine genes expression. Intraperitoneal co-administration of zymosan and morphine significantly inhibits peritonitis in several strains of mice by decreasing the influx of exudatory cells; however, mechanisms of this action still remain unclear. We aimed to verify the effects of morphine on NF-κB and TLRs expression at messenger RNA and protein levels during the early stages of zymosan-induced peritonitis. Peritonitis was induced by a single injection of zymosan A or zymosan supplemented with morphine in Swiss mice. At selected time points, after stimulation, peritoneal leukocytes were harvested. The TLRs and NF-κB expression was assessed by real-time PCR and flow cytometry. In comparison with the mice injected with zymosan only, morphine co-injection significantly decreased the expression of phospho-NF-κB and TLR2 in all investigated immunocompetent cells as well as up-regulated the levels of nitric oxide (NO) in peritoneal fluid. Moreover, supplementation of zymosan with morphine altered the TLR, NF-κB and some proinflammatory cytokines (keratinocyte-derived chemokine, tumor necrosis factor-α) gene expression during ongoing inflammation. We may postulate that after morphine stimulation peritoneal leukocytes recognize less effectively zymosan antigens because of impaired TLRs expression. The lower TLR expression attenuates TLR-mediated signal transduction, which prevents NF-κB activation. Additionally, during zymosan-induced peritonitis, morphine may modulate the NF-κB expression, at least partially, by an up-regulated release of NO, as suggested by others.     

Diallyl Disulfide Suppresses the Inflammation and Apoptosis Resistance Induced by DCA Through ROS and the NF-κB Signaling Pathway in Human Barrett’s Epithelial Cells

Barrett’s esophagus (BE) is generally accepted as the only precursor to esophageal adenocarcinoma (EAC). Deoxycholic acid (DCA)-induced inflammation and apoptotic resistance play an important role in the carcinogenesis and progression from BE to EAC. Diallyl disulfide (DADS) is a garlic-derived natural organosulfur compound. This study investigated whether DADS has chemopreventive effects against BE and the potentially related signaling pathway. BAR-T cells were treated with DCA in the presence or absence of DADS. An MTT assay was used to detect the viability of the cells. The apoptosis rate of the cells was measured by light microscopy and flow cytometry. ROS levels were determined by fluorescence microscopy and flow cytometry. Real-time PCR and ELISA were used to detect mRNA and protein levels, respectively. The levels of target proteins were also determined by western blot analysis. DADS did not inhibit cell viability in a certain concentration range. DADS, similar to the NF-κB inhibitor PDTC, inhibited the DCA-induced ROS production, inflammatory factors, IκBα phosphorylation, and expression of p50 in the nucleus in a dose-dependent manner. DADS also increased the cell apoptosis rate through down-regulating the level of Bcl-2. DADS has low cytotoxicity in BAR-T cells. It has an anti-inflammatory effect in BAR-T cells through inhibiting ROS and the NF-κB signaling pathway. Further, it abolishes the apoptotic resistance induced by DCA in an NF-κB/Bcl-2 dependent manner. DADS may be a good candidate for BE and EAC chemical prevention and therapy.     

Mycoplasma bovis-derived lipid-associated membrane proteins activate IL-1β production through the NF-κB pathway via toll-like receptor 2 and MyD88

Mycoplasma bovis causes pneumonia, otitis media, and arthritis in young calves, resulting in economic losses to the cattle industry worldwide. M. bovis pathogenesis results in part from excessive immune responses. Lipid-associated membrane proteins (LAMPs) can potently induce host innate immunity. However, interactions between M. bovis-derived LAMPs and Toll-like receptors (TLRs), or signaling pathways eliciting active inflammation and NF-κB activation, are incompletely understood. Here, we found that IL-1β expression was induced in embryonic bovine lung (EBL) cells stimulated with M. bovis-derived LAMPs. Subcellular-localization analysis revealed nuclear p65 translocation following EBL cell stimulation with M. bovis-derived LAMPs. An NF-κB inhibitor reversed M. bovis-derived LAMP-induced IL-1β expression. TLR2 and myeloid differentiation primary response gene 88 (MyD88) overexpression increased LAMP-dependent IL-1β induction. TLR2-neutralizing antibodies reduced IL-1β expression during LAMP stimulation. LAMPs also inhibited IL-1β expression following overexpression of a dominant-negative MyD88 protein. These results suggested that M. bovis-derived LAMPs activate IL-1β production through the NF-κB pathway via TLR2 and MyD88.     

Plantamajoside Inhibits Lipopolysaccharide-Induced MUC5AC Expression and Inflammation through Suppressing the PI3K/Akt and NF-κB Signaling Pathways in Human Airway Epithelial Cells

It has been reported that plantamajoside (PMS), a major natural compound isolated from Plantago asiatica, has anti-inflammatory activities. However, the effect of PMS on respiratory inflammatory diseases has not yet been studied. The present study aimed to evaluate the effect of PMS on lipopolysaccharide (LPS)-induced airway inflammation and the underlying mechanism. The results showed that PMS did not affect the cell viability of 16-HBE cells. PMS (20 and 40 μg/ml) decreased the expression levels of MUC5AC, IL-6, and IL-1β, which were induced by LPS treatment. PMS inhibited the LPS-induced phosphorylation of Akt and p65. In addition, inhibitors of the PI3K/Akt and NF-κB pathways attenuated the effect of LPS on 16-HBE cells. In conclusion, PMS inhibits LPS-induced MUC5AC expression and inflammation through suppressing the PI3K/Akt and NF-κB signaling pathways, indicating that PMS may be a potential therapy for the treatment of respiratory inflammatory diseases.