Water Extract of Desalted Salicornia europaea Inhibits RANKL-Induced Osteoclast Differentiation and Prevents Bone Loss in Ovariectomized Mice.

Osteoporosis, which is often associated with increased osteoclast activity due to menopause or aging, was the main focus of this study. We investigated the inhibitory effects of water extract of desalted Salicornia europaea L. (WSE) on osteoclast differentiation and bone loss in ovariectomized mice. Our findings revealed that WSE effectively inhibited RANKL-induced osteoclast differentiation, as demonstrated by TRAP staining, and also suppressed bone resorption and F-actin ring formation in a dose-dependent manner. The expression levels of genes related to osteoclast differentiation, including NFATc1, ACP5, Ctsk, and DCSTAMP, were downregulated by WSE. Oral administration of WSE improved bone density and structural parameters in ovariectomized mice. Dicaffeoylquinic acids (DCQAs) and saponins were detected in WSE, with 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA being isolated and identified. All tested DCQAs, including the aforementioned types, inhibited osteoclast differentiation, bone resorption, and the expression of osteoclast-related genes. Furthermore, WSE and DCQAs reduced ROS production mediated by RANKL. These results indicate the potential of WSE and its components, DCQAs, as preventive or therapeutic agents against osteoporosis and related conditions.

Oral Administration of Lactobacillus sakei CVL-001 Improves Recovery from Dextran Sulfate Sodium-Induced Colitis in Mice by Microbiota Modulation.

Inflammatory bowel disease (IBD) is an intestinal chronic inflammatory disease, and its incidence is steadily increasing. IBD is closely related to the intestinal microbiota, and probiotics are known to be a potential therapeutic agent for IBD. In our study, we evaluated the protective effect of Lactobacillus sakei CVL-001, isolated from Baechu kimchi, on dextran sulfated sodium (DSS)-induced colitis in mice. The oral administration of L. sakei CVL-001 according to the experimental schedule alleviated weight loss and disease activity in the mice with colitis. Furthermore, the length and histopathology of the colon improved. The expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß genes decreased in the colons of mice that were administered L. sakei CVL-001, whereas that of IL-10 increased. The expressions of genes coding for E-cadherin, claudin3, occludin, and mucin were also restored. In co-housed conditions, L. sakei CVL-001 administration did not improve disease activity, colon length, and histopathology. Microbiota analysis revealed that L. sakei CVL-001 administration increased the abundance of microbiota and altered Firmicutes/Bacteroidetes ratio, and decreased Proteobacteria. In conclusion, L. sakei CVL-001 administration protects mice from DSS-induced colitis by regulating immune response and intestinal integrity via gut microbiota modulation.

The sesquiterpene lactone estafiatin exerts anti-inflammatory effects on macrophages and protects mice from sepsis induced by LPS and cecal ligation puncture.

BACKGROUND: Previously, we found that the water extract of Artermisia scoparia Waldst. & Kit suppressed the cytokine production of lipopolysaccharide (LPS)-stimulated macrophages and alleviated carrageenan-induced acute inflammation in mice. Artemisia contains various sesquiterpene lactones and most of them exert immunomodulatory activity. PURPOSE: In the present study, we investigated the immunomodulatory effect of estafiatin (EST), a sesquiterpene lactone derived from A. scoparia, on LPS-induced inflammation in macrophages and mouse sepsis model. STUDY DESIGN AND METHODS: Murine bone marrow-derived macrophages (BMDMs) and THP-1 cells, a human monocytic leukemia cell line, were pretreated with different doses of EST for 2 h, followed by LPS treatment. The gene and protein expression of pro-inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and inducible nitric oxide synthase (iNOS) were measured by quantitative real-time polymerase chain reaction (qPCR) and Western blot analysis. The activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) was also evaluated at the level of phosphorylation. The effect of EST on inflammatory cytokine production, lung histopathology, and survival rate was assessed in an LPS-induced mice model of septic shock. The effect of EST on the production of cytokines in LPS-stimulated peritoneal macrophages was evaluated by in vitro and ex vivo experiments and protective effect of EST on cecal ligation and puncture (CLP) mice was also assessed. RESULTS: The LPS-induced expression of IL-6, TNF-α, and iNOS was suppressed at the mRNA and protein levels in BMDMs and THP-1 cells, respectively, by pretreatment with EST. The half-maximal inhibitory concentration (IC50) of EST on IL-6 and TNF-α production were determined as 3.2 µM and 3.1 µM in BMDMs, 3 µM and 3.4 µM in THP1 cells, respectively. In addition, pretreatment with EST significantly reduced the LPS-induced phosphorylation p65, p38, JNK, and ERK in both cell types. In the LPS-induced mice model of septic shock, serum levels of IL-6, TNF-α, IL-1ß, CXCL1, and CXCL2 were lower in EST-treated mice than in the control animals. Histopathology analysis revealed that EST treatment ameliorated LPS-induced lung damage. Moreover, while 1 of 7 control mice given lethal dose of LPS survived, 3 of 7 EST-treated (1.25 mg/kg) mice and 5 of 7 EST-treated (2.5 mg/kg) mice were survived. Pretreatment of EST dose-dependently suppressed the LPS-induced production of IL-6, TNF-α and CXCL1 in peritoneal macrophages. In CLP-induced mice sepsis model, while all 6 control mice was dead at 48 h, 1 of 6 EST-treated (1.25 mg/kg) mice and 3 of 6 EST-treated (2.5 mg/kg) mice survived for 96 h. CONCLUSION: These results demonstrated that EST exerts anti-inflammatory effects on LPS-stimulated macrophages and protects mice from sepsis. Our study suggests that EST could be developed as a new therapeutic agent for sepsis and various inflammatory diseases.

Receptor-interacting protein kinase 2 contributes to host innate immune responses against Fusobacterium nucleatum in macrophages and decidual stromal cells.

PROBLEM: Chorioamnionitis is caused by a bacterial infection that ascends from the vagina and can cause adverse pregnancy outcomes (APOs). Fusobacterium nucleatum (F. nucleatum) is a periodontal pathogen associated with the occurrence of APOs. In this study, we evaluated whether receptor-interacting protein kinase 2 (Ripk2), an adaptor protein of the cytosolic receptors nucleotide-binding oligomerization domain (NOD)1 and NOD2, in macrophages and human decidual stromal cells (hDSCs) contributes to immune responses against F. nucleatum. METHOD OF STUDY: Bone marrow-derived macrophages (BMDMs) isolated from wild-type (WT) and Ripk2-deficient mice and hDSCs were cultured with F. nucleatum (MOI 1, 10, 100). BMDMs and hDSCs were assessed using enzyme-linked immunosorbent assay, Western blot analysis, real-time PCR, and nitrite assay. RESULTS: Fusobacterium nucleatum-induced production of IL-6, but not of TNF-α and IL-10, was lower in Ripk2-deficient BMDMs than in WT cells. Western blotting revealed a decrease in F. nucleatum-induced p65 phosphorylation in Ripk2-deficient macrophages, whereas mitogen-activated protein kinases activation was comparable between WT and Ripk2-deficient cells. The production of nitric oxide (NO) in response to F. nucleatum and the gene and protein expression of inducible NO synthase was impaired in Ripk2-deficient BMDMs. In hDSCs, F. nucleatum upregulated the gene and protein expression of NOD1, NOD2, and Ripk2 in a time-dependent manner. F. nucleatum also increased the production of IL-6, CXCL8, and CCL2, whereas this production was decreased by the Ripk2 inhibitors SB203580 and PP2. CONCLUSIONS: In conclusion, Ripk2 signaling appears to contribute to the F. nucleatum-induced immune response and can be a preventive and therapeutic target against APOs.

Potentiation of natural killer (NK) cell activity by methanol extract of cultured cambial meristematic cells of wild ginseng and its mechanism.

AIMS: As an alternative strategy to obtain large amounts of ginseng extract with high yield of ginsenosides, we have utilized culture of cambial meristematic cells (CMCs) from wild ginseng. The anti-tumor effects of methanol extract of ginseng CMCs (MEGC) and their action mechanisms were investigated. MAIN METHODS: Mice were intraperitoneally administered with MEGC, and we explored NK cell activity, suppression of in vivo growth of tumor cells and relevant molecule expression. KEY FINDINGS: MEGC significantly potentiated NK cell activity and suppressed in vivo growth of B16 melanoma cells. However, we observed no increase in NK cell number and unaltered expression of NK cell-activating (NKG2D) and inhibitory (Ly49, CD94/NKG2A) receptors as well as NK cell activation markers (CD25, CD69, CD119, and CD212) in MEGC-treated group compared to the controls. Instead, MEGC significantly enhanced IL-2 responsiveness in the early effector phase and the constitutive expression of granzyme B. SIGNIFICANCE: Our data indicate that culture of CMCs is an attractive alternative method for sustainable production of ginseng extracts and clinical use. In addition, we have unraveled a novel mechanism underlying the potentiation of NK cell activity and antitumor effect of ginseng extract, in which it upregulates the constitutive expression of cytotoxic mediator(s) and IL-2 responsiveness.

Helicobacter pylori induces vascular endothelial growth factor production in gastric epithelial cells through hypoxia-inducible factor-1α-dependent pathway.

BACKGROUND: Although Helicobacter pylori have been known to induce vascular endothelial growth factor (VEGF) production in gastric epithelial cells, the precise mechanism for cellular signaling is incompletely understood. In this study, we investigated the role of bacterial virulence factor and host cellular signaling in VEGF production of H. pylori-infected gastric epithelial cells. MATERIALS AND METHODS: We evaluated production of VEGF, activation of nuclear factor nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinases (MAPKs) and hypoxia-inducible factor-1α (HIF-1α) stabilization in gastric epithelial cells infected with H. pylori WT or isogenic mutants deficient in type IV secretion system (T4SS). RESULTS: H. pylori induced VEGF production in gastric epithelial cells via both T4SS-dependent and T4SS-independent pathways, although T4SS-independent pathway seems to be the dominant signaling. The inhibitor assay implicated that activation of NF-κB and MAPKs is dispensable for H. pylori-induced VEGF production in gastric epithelial cells. H. pylori led to HIF-1α stabilization in gastric epithelial cells independently of T4SS, NF-κB, and MAPKs, which was essential for VEGF production in these cells. N-acetyl-cysteine (NAC), a reactive oxygen species (ROS) inhibitor, treatment impaired H. pylori-induced HIF-1α stabilization and VEGF production in gastric epithelial cells. CONCLUSION: We defined the important role of ROS-HIF-1α axis in VEGF production of H. pylori-infected gastric epithelial cells, and bacterial T4SS has a minor role in H. pylori-induced VEGF production of gastric epithelial cells.

Effect of Epigallocatechin-3-Gallate on PMA-Induced MUC5B Expression in Human Airway Epithelial Cells.

OBJECTIVES: Among the inflammatory mediators, phorbol 12-myristate 13-acetate (PMA) is associated with the regulation of MUC5B expression in the airway epithelial cells. Epigallocatechin-3-gallate (EGCG) is the major component of green tea extract. The biological activity of EGCG includes reduction of cholesterol and antioxidant activity, as well as anti-inflammatory effect. However, the precise action mechanism of anti-inflammatory effect of EGCG in the airway epithelial cells has not been fully defined. This study investigates the effect and the brief signaling pathway of EGCG on PMA-induced MUC5B expression in the airway epithelial cells. METHODS: In NCI-H292 airway epithelial cells, the effect and signaling pathway of EGCG on MUC5B expression were investigated using real-time polymerase chain reaction analysis, enzyme immunoassay, immunohistochemical analysis, gelatin zymography assay, and immunoblot analysis. RESULTS: In NCI-H292 airway epithelial cells, PMA induced MUC5B expression, phosphorylation of p38 mitogen-activated protein kinase (MAPK), and matrix metalloproteinase-9 (MMP-9) expression and protein activity. EGCG significantly decreased PMA-induced MUC5B expression, phosphorylation of p38 MAPK, and MMP-9 expression and protein activity. SB203580 (p38 MAPK inhibitor) significantly decreased PMA-induced MMP-9 expression. In addition, SB203580 and MMP-9 I (MMP-9 inhibitor) significantly decreased PMA-induced MUC5B expression. CONCLUSION: These results suggest that EGCG down-regulates PMA-induced MUC5B expression through the p38 MAPK dependent MMP-9 signaling pathway in human airway epithelial cells.

Nucleotide-binding oligomerization domain 2 (Nod2) is dispensable for the innate immune responses of macrophages against Yersinia enterocolitica.

Nucleotide-binding oligomerization domain 2 (Nod2) is a cytosolic sensor for muramyl dipeptide, a component of bacterial peptidoglycan. In this study, we have examined whether Nod2 mediates the immune response of macrophages against Yersinia enterocolitica. Bone-marrow-derived macrophages (BMDMs) were isolated from WT and Nod2-deficient mice and were infected with various strains of Y. enterocolitica. ELISA showed that the production of IL-6 and TNF-α in BMDMs infected with Y. enterocolitica was not affected by the Nod2 deficiency. iNOS mRNA expression was induced in both WT and Nod2-deficienct BMDMs in response to Y. enterocolitica, beginning 2 h after infection. Nitric oxide (NO) production by Y. enterocolitica did not differ between WT and Nod2-deficient BMDMs. Western blot analysis revealed that Y. enterocolitica induces activation of NF-κB, p38, and ERK MAPK through a Nod2-independent pathway. Neither LDH release by Y. enterocolitica nor the phagocytic activity of the macrophages was altered by Nod2 deficiency. An in vivo experiment showed that bacterial clearance ability and production of IL-6 and KC in serum were comparable in WT and Nod2-deficient mice infected with Y. enterocolitica. These findings suggest that Nod2 may not be critical for initiating the innate immune response of macrophages against Yersinia infection.

Activation of Nod1 and Nod2 induces innate immune responses of prostate epithelial cells.

BACKGROUND: Nod1 and Nod2 are cytosolic receptors which are responsible for sensing bacterial peptidoglycan derivatives. In this study, we determined whether Nod1 and Nod2 are involved in the innate immune responses of prostate epithelial cells. METHODS: The expression of Nod1 and Nod2 was examined by RT-PCR and immunohistochemistry. ELISA was performed to determine the production of cytokines/chemokines. Activation of NF-κB and MAPK was examined using western blot analysis. RESULTS: The Nod1 gene was distinctly expressed in all tested cells including DU145, PC3, and TRAMP-C2 cells, whereas Nod2 expression was weak. Both Nod1 and Nod2 proteins were expressed in normal mouse prostate epithelia with difference of expression levels. Tri-DAP (Nod1 agonist), but not MDP (Nod2), increased the production of IL-8 (or KC) and IL-6 in prostate epithelial cells. Tri-DAP and MDP could upregulate the gene expression of COX-2 and activate NF-κB and MAPK. In addition, Tri-DAP and MDP synergized with TLR agonists to induce the production of IL-8/KC or IL-6 in PC3 and TRAMP-C2 cells. We finally showed that Nod1 and Nod2 were also expressed in a wide range of prostate lesions including prostate intraepithelial neoplasm (PIN), phyllodes-like tumor, and adenocarcinoma in TRAMP (transgenic adenocarcinoma of the mouse prostate) mice, even though the expression level of Nod1 and Nod2 was different. CONCLUSION: These results indicate that Nod1 and Nod2 may play important roles in the innate immune response of prostate epithelial cells and the development and progression of prostate cancer.

Flagellin promotes the proliferation of gastric cancer cells via the Toll-like receptor 5.

Signaling of the Toll-like receptor (TLR) is closely associated with tumor development and progression processes including cell proliferation, angiogenesis, metastasis, and immunosuppression. In this study, we examined the expression of TLR5 in gastric cancer cells and its function in cell proliferation. RT-PCR revealed that the TLR5 gene was expressed in all gastric cancer cell lines examined, SNU638, SNU601, SNU216, and AGS. The TLR5 agonist, flagellin, induced IL-8 production and NF-κB activation in the gastric cancer cell lines. In addition, flagellin enhanced the proliferation of all gastric cancer cells examined, whereas LPS did not affect that of SNU638 cells. Blockade of TLR5 using an antibody, restored the proliferation of SNU638 cells enhanced by flagellin, indicating that TLR5 is essential for cell proliferation by flagellin. Flagellin also led to phosphorylation of ERK in SNU638 cells. The ERK inhibitor, PD98059, restored the proliferation ability of SNU638 cells enhanced by flagellin, suggesting that ERK may play an important role in the proliferation of gastric cancer cells. These findings suggest that TLR5 may play an important role in tumor progression of gastric cancer via the regulation of cell proliferation.

Therapeutic target validation of protein kinase C(PKC)-zeta for asthma using a mouse model.

Protein kinase C (PKC) is a complex family consisting of many types of isoenzymes, of which PKC-zeta, an atypical isoform, has been reportedly implicated in the regulation of apoptosis and NF-kappaB, as well as control of T-dependent responses. Based on the recent report that PKC-zeta controls TH2 response, the current study was aimed to evaluate PKC-zeta as a potential therapeutic target for asthma using a mouse model. Mouse allergic asthma was induced by repeated sensitization followed by intranasal challenge with OVA and PKC-zeta pseudosubstrate inhibitor (PPI) was intratracheally instilled before each OVA challenge. Airway hyperreactivity (AHR) was measured by beta-methacoline-induced airflow obstruction. Cellular and cytokine profile in bronchoalveolar lavage fluid (BALF) and level of serum IgE as well as cytokine production by draining lymph node cells were compared. AHR and numbers of eosinophils in BALF were significantly lowered by PPI, indicating that blocking of PKC-zeta activation alleviates asthmatic manifestations. Additionally, PPI instillation decreased IL-5 and IL-13 levels in BALF to approximately 20% of controls, but not IFN-gamma level. Instillation of PPI also caused a marked fall in the level of TNF-alpha, another NF-kappaB-dependent, proinflammatory cytokine. Serum OVA-specific IgE level and ex vivo IL-4, IL-5 and IL-13, but not IFN-gamma, production by peribronchial lymph node cells was also considerably lower in PPI-treated mice. In conclusion, blockade of PKC-zeta signals by intratracheal instillation of PPI alleviates allergen-specific TH2 response as well as asthmatic manifestations and hence PKC-zeta is a promising target for treatment of asthma.

Oral administration of aqueous extract of Carthami Flos induces macrophage activation and preferentially potentiates type 1 helper T-cell response in vivo.

In vivo immunomodulatory activity of aqueous extract of Carthami Flos (AECF) was investigated using a mouse model immunized with keyhole limpet hemocyanin. Serum level of Ag-specific IgG2a was significantly elevated by oral administration of AECF but not IgG1. However, no selective B-cell proliferation by AECF was observed in vivo. Ag-specific proliferation and IFN-gamma and IL-5 production of draining lymph node T cells also was higher in AECF-treated mice when compared with water-treated control mice. However, AECF failed to enhance nonspecific T-cell response under CD3 stimulation. These results led us to hypothesize that AECF potentiates Ag-specific T-cell response, possibly through activation of antigen presenting cells (APC) other than B cells. Functional assessment of splenic macrophages showed that AECF administration significantly enhances IL-12 production as well as APC activity for IFN-gamma production and STAT-4 activation by T cells. Collectively, these data strongly support that AECF preferentially potentiates immune response polarized toward TH1 and for which increased activation of macrophages is most likely to be responsible. The present data implicate a possible application of AECF to potentiate cellular immunity and, we hope, prevent intracellular infections.