Dataset Information

Daidzein suppresses pro-inflammatory chemokine Cxcl2 transcription in TNF-α-stimulated murine lung epithelial cells via depressing PARP-1 activity.

ABSTRACT: Daidzein (4',7-dihydroxyisoflavone) is an isoflavone exiting in many herbs that has shown anti-inflammation activity. The aim of this study was to investigate the mechanism underlying its anti-inflammatory action in murine lung epithelial cells.C57BL/6 mice were intranasally exposed to TNF-α to induce lung inflammation. The mice were injected with daidzein (400 mg/kg, ip) before TNF-α challenge, and sacrificed 12 h after TNF-α challenge, and lung tissues were collected for analyisis. In in vitro studies, murine MLE-12 epithelial cells were treated with TNF-α (20 ng/mL). The expression of pro-inflammatory chemokine Cxcl2 mRNA and NF-κB transcriptional activity were examined using real-time PCR and a dual reporter assay. Protein poly-adenosine diphosphate-ribosylation (PARylation) was detecyed using Western blotting and immunoprecipitation assays.Pretreatment of the mice with daidzein markedly attenuated TNF-α-induced lung inflammation, and inhibited Cxcl2 expression in lung tissues. Furthermore, daidzein (10 μmol/L) prevented TNF-α-induced increases in Cxcl2 expression and activity and NF-κB transcriptional activity, and markedly inhibited TNF-α-induced protein PARylation in MLE-12 cells in vitro. In MLE-12 cells co-transfected with the PARP-1 expression plasmid and NF-κB-luc (or Cxcl2-luc) reporter plasmid, TNF-α markedly increased NF-κB (or Cxcl2) activation, which were significantly attenuated in the presence of daidzein (or the protein PARylation inhibitor PJ 34). PARP-1 activity assay showed that daidzein (10 μmol/L) reduced the activity of PARP-1 by ∼75%.The anti-inflammatory action of daidzein in murine lung epithelial cells seems to be mediated via a direct interaction with PARP-1, which inhibits RelA/p65 protein PARylation required for the transcriptional modulation of pro-inflammatory chemokines such as Cxcl2.

SUBMITTER: Li HY

PROVIDER: S-EPMC4813725 | biostudies-other | 2014 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BackgroundPhosphatidylcholine (PC) is a major lipid of the gastrointestinal mucus layer. We recently showed that mucus from patients suffering from ulcerative colitis has low levels of PC. Clinical studies reveal that the therapeutic addition of PC to the colonic mucus using slow release preparations is beneficial. The positive role of PC in this disease is still unclear; however, we have recently shown that PC has an intrinsic anti-inflammatory property. It could be demonstrated that the exogenous application of PC inhibits membrane-dependent actin assembly and TNF-alpha-induced nuclear NF-kappaB activation. We investigate here in more detail the hypothesis that the exogenous application of PC has anti-inflammatory properties.MethodsPC species with different fatty acid side chains were applied to differentiated and non-differentiated Caco-2 cells treated with TNF-alpha to induce a pro-inflammatory response. We analysed TNF-alpha-induced NF-kappaB-activation via the transient expression of a NF-kappaB-luciferase reporter system. Pro-inflammatory gene transcription was detected with the help of a quantitative real time (RT)-PCR analysis. We assessed the binding of TNF-alpha to its receptor by FACS and analysed lipid rafts by isolating detergent resistant membranes (DRMs).ResultsThe exogenous addition of all PC species tested significantly inhibited TNF-alpha-induced pro-inflammatory signalling. The expression levels of IL-8, ICAM-1, IP-10, MCP-1, TNF-alpha and MMP-1 were significantly reduced after PC pre-treatment for at least two hours. The effect was comparable to the inhibition of NF-kB by the NF-kB inhibitor SN 50 and was not due to a reduced binding of TNF-alpha to its receptor or a decreased surface expression of TNF-alpha receptors. PC was also effective when applied to the apical side of polarised Caco-2 cultures if cells were stimulated from the basolateral side. PC treatment changed the compartmentation of the TNF-alpha-receptors 1 and 2 to DRMs.ConclusionPC induces a prolonged inhibition of TNF-alpha-induced pro-inflammatory signalling. This inhibition may be caused by a shift of the TNF-alpha receptors at the surface to lipid rafts. Our results may offer a potential molecular explanation for the positive role of PC seen in clinical studies for the treatment of ulcerative colitis.

Project description:PURPOSE: To investigate the modulatory effect of rat bone marrow mesenchymal stem cells (MSC) on human corneal epithelial cells (HCE-T) stimulated with pro-inflammatory cytokines interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) in an in vitro co-cultured model. METHODS: HCE-T alone and co-cultured with MSC were stimulated with IFN-γ/TNF for 24 and 48 hours or left untreated. The expression of intracellular adhesion molecule (ICAM)-1, human leukocyte antigen ABC, DR and G (HLA-ABC, HLA-DR, HLA-G) were investigated by flow cytometry. Subcellular localization of nuclear factor-kappa B (NF-κB) and expression of indoleamine 2,3-dioxygenase (IDO) were assessed by immunofluorescence staining and western blot. The concentration of transforming growth factor beta 1 (TGF-β1) in the conditioned media from different cultures was evaluated by enzyme-linked immunosorbent assay. NF-κB and TGF-β1 signaling pathway blocking experiments were performed to analyze associations between the expression of cell surface molecules and the NF-κB transcription pathway, and the expression of IDO and TGF-β1 signaling pathway. RESULTS: IFN-γ/TNF treatment significantly up-regulated expression of ICAM-1, HLA-ABC, and induced de novo expression of HLA-DR and IDO on HCE-T cultured alone, while HLA-G expression remained unaffected. Up-regulation was significantly inhibited by co-culture with MSC. Increased TGF-β1 secretion was detected in 48 h IFN-γ/TNF-stimulated MSC monocultures and HCE-T/MSC co-cultures. MSC attenuated the activation of cytokine-induced NF-κB and IDO induction. Blockade of NF-κB transcription pathway by BMS-345541 significantly reduced the up-regulation of ICAM-1, HLA-ABC, HLA-DR and IDO expression, while blockade of TGF-β1 signaling pathways reversed the modulatory effect of MSC on IDO expression. CONCLUSIONS: MSC reduced the expression of adhesion and immunoregulatory molecules on pro-inflammatory cytokine-stimulated HCE-T via the NF-κB transcription pathway. MSC attenuated expression of IDO through both NF-κB transcription and TGF-β1 signaling pathways. Co-culture of HCEC with MSC therefore provides a useful in vitro model to study the anti-inflammatory properties of MSC on corneal epithelium.

Project description:IntroductionMelioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei, is a disease endemic in many tropical countries globally. Clinical presentation is highly variable, ranging from asymptomatic to fatal septicemia, and thus the outcome of infection can depend on the host immune responses. The aims of this study were to firstly, characterize the macrophage immune response to B. pseudomallei and secondly, to determine whether the immune response was modified in the presence of novel inhibitors targeting the virulence factor, the macrophage infectivity potentiator (Mip) protein. We hypothesized that inhibition of Mip in B. pseudomallei would disarm the bacteria and result in a host beneficial immune response.MethodsMurine macrophage J774A.1 cells were infected with B. pseudomallei K96243 in the presence of small-molecule inhibitors targeting the Mip protein. RNA-sequencing was performed on infected cells four hours post-infection. Secreted cytokines and lactose dehydrogenase were measured in cell culture supernatants 24 hours post-infection. Viable, intracellular B. pseudomallei in macrophages were also enumerated 24 hours post-infection.ResultsGlobal transcriptional profiling of macrophages infected with B. pseudomallei by RNA-seq demonstrated upregulation of immune-associated genes, in particular a significant enrichment of genes in the TNF signaling pathway. Treatment of B. pseudomallei-infected macrophages with the Mip inhibitor, AN_CH_37 resulted in a 5.3-fold reduction of il1b when compared to cells treated with DMSO, which the inhibitors were solubilized in. A statistically significant reduction in IL-1β levels in culture supernatants was seen 24 hours post-infection with AN_CH_37, as well as other pro-inflammatory cytokines, namely IL-6 and TNF-α. Treatment with AN_CH_37 also reduced the survival of B. pseudomallei in macrophages after 24 hours which was accompanied by a significant reduction in B. pseudomallei-induced cytotoxicity as determined by lactate dehydrogenase release.DiscussionThese data highlight the potential to utilize Mip inhibitors in reducing potentially harmful pro-inflammatory responses resulting from B. pseudomallei infection in macrophages. This could be of significance since overstimulation of pro-inflammatory responses can result in immunopathology, tissue damage and septic shock.

Project description:We have recently shown that the toxicological potential of GaAs and InAs particulates in cells is size- and dissolution-dependent, tending to be more pronounced for nano- vs micron-sized particles. Whether the size-dependent dissolution and shedding of ionic III-V materials also apply to pulmonary exposure is unclear. While it has been demonstrated that micron-sized III-V particles, such as GaAs and InAs, are capable of inducing hazardous pulmonary effects in an occupational setting as well as in animal studies, the effect of submicron particles (e.g., the removal of asperities during processing of semiconductor wafers) is unclear. We used cytokine profiling to compare the pro-inflammatory effects of micron- and nanoscale GaAs and InAs particulates in cells as well as the murine lung 40 h and 21 days after oropharyngeal aspiration. Use of cytokine array technology in macrophage and epithelial cell cultures demonstrated a proportionally higher increase in the levels of matrix metalloproteinase inducer (EMMPRIN), macrophage migration inhibitory factor (MIF), and interleukin 1β (IL-1β) by nanosized (n) GaAs and n-InAs as well as As(III). n-GaAs and n-InAs also triggered higher neutrophil counts in the bronchoalveolar lavage fluid (BALF) of mice than micronscale particles 40 h post-aspiration, along with increased production of EMMPRIN and MIF. In contrast, in animals sacrificed 21 days after exposure, only n-InAs induced fibrotic lung changes as determined by increased lung collagen as well as increased levels of TGF-β1 and PDGF-AA in the BALF. A similar trend was seen for EMMPRIN and matrix metallopeptidase (MMP-9) levels in the BALF. Nano- and micron-GaAs had negligible subacute effects. Importantly, the difference between the 40 h and 21 days data appears to be biopersistence of n-InAs, as demonstrated by ICP-OES analysis of lung tissue. Interestingly, an ionic form of In, InCl3, also showed pro-fibrogenic effects due to the formation of insoluble In(OH)3 nanostructures. All considered, these data indicate that while nanoscale particles exhibit increased pro-inflammatory effects in the lung, most effects are transient, except for n-InAs and insoluble InCl3 species that are biopersistent and trigger pro-fibrotic effects. These results are of potential importance for the understanding the occupational health effects of III-V particulates.

Dataset Information

Daidzein suppresses pro-inflammatory chemokine Cxcl2 transcription in TNF-α-stimulated murine lung epithelial cells via depressing PARP-1 activity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets