Interleukin-18 enhances breast cancer cell migration via down-regulation of claudin-12 and induction of the p38 MAPK pathway.

Interleukin-18 (IL-18) was recently reported to have a pro-tumor effect in various cancers. Increased IL-18 levels in the serum of cancer patients correlated with malignancy, and IL-18 acts a crucial factor for cell migration in gastric cancer and melanoma. Claudins, which are the most important tight junction proteins, are also linked with cancer progression and metastasis. However, the relationship between claudins and IL-18 is not well-understood. Here, we show that the migratory ability of MCF-7 cells was reduced when endogenous IL-18 expression was inhibited with IL-18 siRNA. Moreover, exogenous IL-18 enhanced breast cancer cell migration and suppressed the expression of the tight junction proteins claudin-1, claudin-3, claudin-4, and claudin-12 in MCF-7 cells. Knockdown of claudin-3, claudin-4, and claudin-12, but not claudin-1, increased breast cancer migration with maximal effects observed in claudin-12 siRNA-transfected cells. To investigate whether the mitogen-activated protein kinase (MAPK) signaling pathway is involved in IL-18-induced cell migration and claudin-12 expression, cells were pretreated with SB203580 (an inhibitor of p38 MAPK) or PD98059 (an inhibitor of ERK1/2) prior to the addition of IL-18. Although pretreatment of MCF-7 cells with SB203580 blocked both the enhanced cell migration and the decreased claudin-12 expression, PD98059 only blocked cell migration and did not affect claudin-12 expression. In addition, exogenous IL-18 induced rapid phosphorylation of p38 MAPK. These results suggest that IL-18 is an important factor inducing breast cancer cell migration through down-regulation of claudin-12 and activation of the p38 MAPK pathway.

NF-κB inhibitory activity of polyoxygenated steroids from the Vietnamese soft coral Sarcophyton pauciplicatum.

Chromatographic purification of the methanolic extract from the soft coral Sarcophyton pauciplicatum led to the isolation of three polyhydroxylated steroids 1-3, including a new compound, sarcopanol A (1). Their structures were elucidated by spectroscopic analysis and by comparison of the spectroscopic data with those of similar compounds previously reported in literature. The anti-inflammatory effects of isolated compounds were evaluated using nuclear factor kappa B (NF-κB) luciferase and reverse transcription polymerase chain reaction (RT-PCR). The effect of isolated compounds on cell growth was evaluated by MTS assays. Compounds 1 and 2 significantly inhibited TNFα/INFγ-induced NF-κB transcriptional activity in human keratinocyte (HaCaT) cells in a dose-dependent manner, with EC50 values of 8.27±3.28 and 26.07±5.59 µM, respectively. Furthermore, the transcriptional inhibition of these compounds was confirmed by a decrease in cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and intercellular adhesion molecule-1 (ICAM-1) gene expression levels in HaCaT cells.

New anti-inflammatory cembranoid diterpenoids from the Vietnamese soft coral Lobophytum crassum.

Four new cembranoid diterpenes lobocrasols A-D (1-4), were isolated from the methanol extract of the soft coral Lobophytum crassum. Their structures were elucidated by spectroscopic analysis and by comparison of the spectroscopic data with those of similar compounds previously reported in literature. The anti-inflammatory effects of isolated compounds were evaluated using NF-κB luciferase and reverse transcription polymerase chain reaction (RT-PCR). Compounds 1 and 2 significantly inhibited TNFα-induced NF-κB transcriptional activity in HepG2 cells in a dose-dependent manner, with IC50 values of 6.30±0.42 and 6.63±0.11µM, respectively. Furthermore, the transcriptional inhibition of these compounds was confirmed by a decrease in cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) gene expression levels in HepG2 cells.

Sterol fatty acid esters from the mushroom Hericium erinaceum and their PPAR transactivational effects.

Six new (erinarols A-F, 1-6) and five known (7-11) ergostane-type sterol fatty acid esters were isolated from the methanol extract of the dried fruiting bodies of Hericium erinaceum. Their chemical structures were elucidated using chemical and physical methods as well as through comparison of NMR and mass spectral data with those reported previously. This is the first comprehensive investigation on ergostane-type sterol fatty acid esters from H. erinaceum. The isolated compounds were evaluated for their PPAR transactivational effects using a luciferase reporter system. Compounds 1 and 2 significantly activated the transcriptional activity of PPARs in a dose-dependent manner, with EC50 values of 8.2 and 6.4 µM, respectively. Moreover, compounds 1 and 2 also activated PPARα and PPARγ transcriptional activity, with stimulation from 1.3- to 3.9-fold at 20 µM concentrations.

Phenolic components from the stem of Acanthopanax koreanum and their inhibitory effects on NF-kappa B.

Two novel phenolic glucosides (1-2), as well as seven known compounds (3-9), were isolated from the stem of Acanthopanax koreanum; their chemical structures were determined by chemical and spectroscopic methods and subsequently compared with previously reported data. Their inhibition of nuclear factor kappa B (NF-κB) was measured in human embryonic kidney (293T) cells by using an NF-κB luciferase assay.

NF-κB inhibitory activities of glycosides and alkaloids from Zanthoxylum schinifolium stems.

Zanthoxylum schinifolium is an aromatic shrub, the pericarp and leaves of which are widely used in culinary applications in East Asian countries. In the present study, one new neolignan glycoside, zanthoxyloside A (1) together with 16 known glycosides (2-12) and alkaloids (13-17), were isolated from methanol extract of the stems of Z. schinifolium. The absolute configuration of one known monoterpenoid glycoside (2) was determined. The structures of the isolated compounds were established by one dimensional (1D), 2D NMR and mass spectrometry. The nuclear factor-κB (NF-κB) inhibitory activities of the isolated compounds stimulated with tumor necrosis factor alpha (TNFα) were measured using a luciferase reporter system. Compounds 1, 5, 16, and 17 exhibited significant inhibition of NF-κB activation in a dose-dependent manner. Furthermore, compounds 1, 5, 16, and 17 inhibited TNFα-induced expression of inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1) mRNA and dose-dependent inhibition of iNOS promoter activity.

Cembranoid diterpenes from the soft coral Lobophytum crassum and their anti-inflammatory activities.

Nine cembranoid diterpenes 1-9, including four new compounds, crassumols D-G (1-4), were isolated from the methanol extract of the Vietnamese soft coral Lobophytum crassum. Spectroscopic methods were used to elucidate the structures of these compounds. Compound 5 exhibited a potent inhibitory effect on tumor necrosis factor-alpha (TNFα)-induced nuclear factor-kappa B (NF-κB) transcriptional activation in HepG2 cells and significantly inhibited the mRNA expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in a dose-dependent manner.

Anti-inflammatory and PPAR transactivational effects of secondary metabolites from the roots of Asarum sieboldii.

Phytochemical study on the roots of Asarum sieboldii resulted in the isolation of one new compound, (1R,2S,5R,6R)-5'-O-methylpluviatilol (1) and 12 known compounds (2-13). Their structures were determined by extensive spectroscopic methods, including 1D and 2D NMR, and MS spectra. The absolute configuration of compound 1 was established using CD spectrum. Compounds 4, 5, and 12/13 significantly inhibited TNFα-induced NF-κB transcriptional activity in HepG2 cells in a dose-dependent manner, with IC(50) values ranging from 6.4 to 9.4 µM. Furthermore, the transcriptional inhibitory function of these compounds was confirmed based on decreases in COX-2 and iNOS gene expression in HepG2 cells. Compounds 1-3, 6,7, 10, and 11 significantly activated the transcriptional activity of PPARs in a dose-dependent manner, with EC(50) values ranging from 1.7 to 20.9 µM. Compounds 7, 10, and 11 exhibited significant dose-dependent PPARα transactivational activity, with EC(50) values of 19.5, 15.7, and 4.0 µM, respectively. Compounds 1, 6, 7, 10, and 11 activated PPARγ transcriptional activity, with EC(50) values ranging from 3.6 to 22.6 µM, whereas compounds 10 and 11 significantly increased PPARß(δ) transactivational activity, with EC(50) values of 22.6 and 4.9 µM, respectively. These results provide a scientific support for the use of the roots of A. sieboldii and warrant further studies to develop new agents for the prevention and treatment of the inflammatory and metabolic diseases.

Insulin represses transcription of the thyroid stimulating hormone beta-subunit gene through increased recruitment of nuclear factor I.

Although the regulation of thyroid stimulating hormone ß-subunit gene (TSHß) has been intensively studied, the functions of transcription factors involved are not fully understood. The authors found that the -615/-516 promoter region of the TSHß interacts specifically with nuclear proteins derived from pituitary tissue or from cultured thyrotroph cells. The actual binding site at the nucleotide level, as revealed by DNase I protection assay, includes the consensus sequence for nuclear factor I (NFI). RT-PCR analysis indicated that NFI-B expression is restricted to thyrotroph cells in the anterior pituitary. EMSA and ChIP analysis showed that NFI-B binds most efficiently to the -588/-560 region of TSHß promoter. The forced expressions of NFI-B markedly reduced TSHß promoter activity and its mRNA expression. Furthermore, it was also shown that the -588/-560 region is involved in the insulin-mediated repression of the TSHß. It was of particular interest to observe that NFI-B was recruited to the -588/-560 region of the TSHß promoter in an insulin-dependent manner. Taken together, this study provides new insights of the delicate regulations of energy metabolism and hormonal homeostasis.

Erythroid differentiation regulator 1 (Erdr1) is a proapototic factor in human keratinocytes.

Skin is constantly exposed to physical and chemical stressors. The exposure of keratinocytes to ultraviolet B (UVB) irradiation causes epidermal damage via induction of apoptosis. Erythroid differentiation regulator 1 (Erdr1) modulates growth and survival of cells under various stressful conditions, but the function of Erdr1 in human keratinocyte apoptosis has not been investigated so far. Here, we investigated the effect of Erdr1 on UVB-induced apoptosis in human keratinocytes and also examined the underlying regulatory mechanism. First, Erdr1 expression was detected in human primary keratinocytes and normal human skin tissues. Expression of Erdr1 was enhanced in human keratinocytes following UVB irradiation. Knock-down of Erdr1 led to resistance to UVB-induced apoptosis. Also, Erdr1 overexpression increased UVB-induced apoptosis and induced caspase-3 activation. Furthermore, the extracellular signal-regulated kinase (ERK) inhibitor PD98059 and the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 significantly reduced Erdr1 expression following UVB irradiation. These results indicate that UVB induces Erdr1 via a MAPK-dependent mechanism. Taken together, these findings suggest that Erdr1 has a role as a proapoptotic factor in human keratinocytes and acts via ERK and p38 MAPK pathways. Therefore, Erdr1 may be a potential therapeutic target to reduce apoptosis in keratinocytes in conditions such as psoriasis and skin cancer.

Oleanane-type triterpene saponins from the bark of Aralia elata and their NF-κB inhibition and PPAR activation signal pathway.

Two new oleanane-type triterpene saponins, tarasaponin IV (1) and elatoside L (2), and four known; stipuleanoside R(2) (3), kalopanax-saponin F (4), kalopanax-saponin F methylester (5), and elatoside D (6) were isolated from the bark of Aralia elata. Kalopanax-saponin F methyl ester was isolated from nature for the first time. Their chemical structures were elucidated using the chemical and physical methods as well as good agreement with those of reported in the literature. Oleanane-type triterpene saponins are the main component of A. elata. All compounds were investigated the anti-inflammatory activity. We measured their inhibition of NF-κB and activation of PPARs activities in HepG2 cells using luciferase reporter system. As results, compounds 2 and 4 were found to inhibit NF-κB activation stimulated by TNFα in a dose-dependent manner with IC(50) values of 4.1 and 9.5 µM, respectively, when compared with that of positive control, sulfasalazine (0.9 µM). Compounds 2 and 4 also inhibited TNFα-induced expression of iNOS and COX-2 mRNA. Furthermore, compounds 1-6 were evaluated PPAR activity using PPAR subtype transactivation assays. Among of them, compounds 4-6 significantly increased PPARγ transactivation. However, compounds 4-6 did not activate in any other PPAR subtypes.

Cytotoxic and PPARs transcriptional activities of sterols from the Vietnamese soft coral Lobophytum laevigatum.

A new unusual sterol, named lobophytosterol (1), and five known metabolites (2-6) were isolated from the methanol extract of the soft coral Lobophytum laevigatum. Their chemical structures were elucidated by extensive spectroscopic analysis and comparison with those reported in the literature. The absolute stereochemistry of 1 was determined using a modified Mosher's method. Compounds 1-3 showed cytotoxic activity against HCT-116 cells with IC(50) values of 3.2, 6.9 and 18.1 µM, respectively. Compound 1 additionally displayed cytotoxic effects on A549 and HL-60 cells with IC(50) values of 4.5 and 5.6 µM, respectively. Treatment of these cells with compound 1 resulted in an induction of apoptosis evident by chromatin condensation in treated cells. Besides, compounds 2, 4, and 6 significantly upregulated PPARs transcriptional activity dose-dependently in Hep-G2 cells. Taken together, these data suggest that compound 1 might inhibit the growth of the cancer cells by the induction of apoptosis, and compounds 2, 4, and 6 might act as specific agonists for PPARα, PPARδ, and PPARγ and may therefore regulate cellular glucose, lipid, and cholesterol metabolism.

Cytotoxic and anti-inflammatory cembranoids from the Vietnamese soft coral Lobophytum laevigatum.

Four new cembranoids, namely laevigatol A-D (1-4), and six known metabolites (5-10), were isolated from the Vietnamese soft coral Lobophytum laevigatum. The structures of these compounds were elucidated by extensive spectroscopic analyses, and the absolute stereochemistry of 1 was determined using the modified Mosher's method. Compounds 5, and 7-10 exhibited cytotoxic activity against selected human cancer cell lines. Compounds 1, 2, 8, and 9 showed dose-dependent inhibitory effects on the TNFα-induced NF-κB transcriptional activity in Hep-G2 cells. Moreover, compounds 1, 2, 8, and 9 significantly inhibited the induction of COX-2 and iNOS mRNA dose-dependently, indicating that these compounds attenuated the synthesis of these transcripts at the transcriptional level.

Dammarane triterpenes and phytosterols from Dysoxylum tpongense Pierre and their anti-inflammatory activity against liver X receptors and NF-κB activation.

Dysoxylum tpongense Pierre (local name 'Huynh Dan Bap') belonging to family Meliaceae, is a tree (3-10 m height), distributed in the mountainous areas (ca. 1000 m a.s.l.) in North Vietnam. From the dichloromethane fraction of the methanol extract of the leaves and stems of this plant, six dammarane triterpenes, one furanoid diterpene together with three sterols were isolated. Evaluation of biological activities of isolated compounds showed that cabraleahydroxylactone (5), cabraleahydroxylactone 3-acetate (6), and stigmast-4-en-3-one (10) possessed an anti-inflammatory effect against Liver X receptor (LXR) activation in HepG2 cell line model with IC50 values of 20.29 ± 3.69, 24.32 ± 2.99, and 7.09 ± 0.97 (µM), respectively. While three other triterpenoid compounds aglinin C 3- acetate (1), aglinin C (2), and 24-epi-cabraleadiol (4) presented the most significant inhibitory effect against TNF-α induced NF-κB activation in HepG2 cell line in a dose-dependent manner with IC50 values of 12.45 ± 2.37, 23.32 ± 3.25, and 13.95 ± 1.57 µM, respectively. As stigmast-4-en-3-one (10), with structure closely similar to cholesterol, acted selectively on LXRs but not on NF-kB activation pathway, this suggests that stigmast-4-en-3-one (10) can be potentially applied as an agonist on LXR signaling pathway. Pathways LXRs-NF-κB-iNOS expression have a close relationship and play a crucial role in proceeding metabolic abnormalities like atherosclerosis, obesity, inflammation, etc. Thus, the findings showed that dammarane-type triterpenoids from D. tpongense are worthy of further investigation for potential LXR agonists and potent anti-atherogenic agents against atherosclerotic lesion progression.

Stabilization and translocation of p53 to mitochondria is linked to Bax translocation to mitochondria in simvastatin-induced apoptosis.

Statins are cholesterol-lowing drugs with pleiotropic effects including cytotoxicity to cancer cells. In this study, we investigated the signaling pathways leading to apoptosis by simvastatin. Simvastatin induced cardinal features of apoptosis including increased DNA fragmentation, disruption of mitochondrial membrane potential (MMP), and increased caspase-3 activity by depleting isoprenoids in MethA fibrosarcoma cells. Interestingly, the simvastatin-induced apoptosis was accompanied by p53 stabilization involving Mdm2 degradation. The apoptosis was ameliorated in p53 knockdown clones of MethA cells as well as p53(-/-) HCT116 cells. The stabilized p53 protein translocated to mitochondria with Bax, and cytochrome c was released into cytosol. Moreover, knockdown or deficiency of p53 expression reduced both Bax translocation to mitochondria and MMP disruption in simvastatin-induced apoptosis. Taken together, these all indicate that stabilization and translocation of p53 to mitochondria is involved in Bax translocation to mitochondria in simvastatin-induced apoptosis.

Botulinum toxin enhances the implantation effect of adipocytes in C57/BL6 mice.

BACKGROUND: Recently, many plastic surgeons have been using adipogenic-differentiated cell implantation for remodeling scars in patients. However, this technique is not a long-term solution because implanted cells disappear gradually. Therefore, we investigated a method to increase the grafted cell preservation rate by using an effective adjuvant, botulinum toxin. METHODS: The adipogenic-differentiated cells were subcutaneously injected in the dorsal area of C57/BL6 mice with or without botulinum toxin. Two and six weeks later we analyzed the residual volume and confirmed the characteristics of the implanted cells by real-time RT-PCR and immunohistochemistry. RESULTS: Two and six weeks after transplantation we found that the residual volume of the transplantation site was higher in the botulinum toxin-treated group than in the untreated group. We also confirmed that the residual transplanted area has characteristics of adipogenic tissue by histological analysis. Next, to determine the mechanism related to the enhanced preservation rate of grafted cells via treatment with botulinum toxin, we performed immunohistochemical staining for the angiogenesis-related marker CD31. We found that CD31 expression was higher in the botulinum toxin-treated group than in the untreated group. CONCLUSION: We have shown that in vivo grafted adipocyte cell preservation can be enhanced by treatment with botulinum toxin as an adjuvant. We suggest that botulinum toxin further increases this graft preservation rate by enhancing angiogenesis.

Sphingosine kinase inhibitor suppresses IL-18-induced interferon-gamma production through inhibition of p38 MAPK activation in human NK cells.

Natural killer (NK) cells play an important role in the innate immune response. Interleukin-18 (IL-18) is a well-known interferon-gamma (IFN-gamma inducing factor, which stimulates immune response in NK and T cells. Sphingosine kinase (SPHK) catalyzes the formation of sphingosine 1-phosphate (S1P), which acts as a second messenger to function as an anti-apoptotic factor and proliferation stimulator of immune cells. In this study, to elucidate whether SPHK is involved in IL-18-induced IFN-gamma production, we measured IL-18-induced IFN-gamma production after pre-treatment with SPHK inhibitor (SKI) in NK-92MI cells. We found that IL-18-induced IFN-gamma expression was blocked by SKI pre-treatment in both mRNA and protein levels. In addition, the increased IFN-gamma production by stimulation with IL-18 is mediated through both SPHK and p38 MAPK. To determine the upstream signals of SKI and p38 MAPK in IL-18-induced IFN-gamma production, phosphorylation levels of p38 MAPK was measured after SKI pre-treatment. As a result, inhibition of SPHK by SKI blocked phosphorylation of p38 MAPK, showing that SPHK activation by IL-18 is an upstream signal of p38 MAPK activation. Inhibition of SPHK by SKI also inhibited IL-18-induced IFN-gamma production in human primary NK cells. In conclusion, SPHK activation is an essential factor for IL-18-induced IFN-gamma production via p38 MAPK.

Nuclear Factor Kappa B Activation and Peroxisome Proliferator-activated Receptor Transactivational Effects of Chemical Components of the Roots of Polygonum multiflorum.

BACKGROUND: Polygonum multiflorum is well-known as "Heshouwu" in traditional Chinese herbal medicine. In Northeast Asia, it is often used as a tonic to prevent premature aging of the kidney and liver, tendons, and bones and strengthening of the lower back and knees. OBJECTIVE: To research the anti-inflammatory activities of components from P. multiflorum. MATERIALS AND METHODS: The compounds were isolated by a combination of silica gel and YMC R-18 column chromatography, and their structures were identified by analysis of spectroscopic data (1D, 2D-nuclear magnetic resonance, and mass spectrometry). The anti-inflammatory activities of the isolated compounds 1-15 were evaluated by luciferase reporter gene assays. RESULTS: Fifteen compounds (1-15) were isolated from the roots of P. multiflorum. Compounds 1-5 and 14-15 significantly inhibited tumor necrosis factor-α-induced nuclear factor kappa B-luciferase activity, with IC50 values of 24.16-37.56 µM. Compounds 1-5 also greatly enhanced peroxisome proliferator-activated receptors transcriptional activity with EC50 values of 18.26-31.45 µM. CONCLUSION: The anthraquinone derivatives were the active components from the roots of P. multiflorum as an inhibitor on inflammation-related factors in human hepatoma cells. Therefore, we suggest that the roots of P. multiflorum can be used to treat natural inflammatory diseases. SUMMARY: This study presented that fifteen compounds (1-15) isolated from the roots of Polygonum multiflrum exert signifiant anti inflmmatory effects by inhibiting TNF α induced NF κB activation and PPARs transcription. Abbreviation used: NF κB: Nuclear factor kappa B, PPARs: Peroxisome proliferator activated receptors, PPREs: Peroxisome proliferator response elements, TNF α: Tumor necrosis factor α, ESI-MS: Electrospray ionization mass spectrometry, HepG2: Human hepatoma cells.

A new phenolic derivative with soluble epoxide hydrolase and nuclear factor-kappaB inhibitory activity from the aqueous extract of Acacia catechu.

One novel phenolic compound, (4S,5R)-4-(3,4-dihydroxyphenyl)-5-(3-oxobutyl)dihydrofuran-2(3H)-one (1), as well as 12 known compounds (2-13) was obtained from the aqueous extract of Acacia catechu and their chemical structures were determined by spectroscopic analysis. Compounds 8 and 9 exhibited significant soluble epoxide hydrolase (sEH) inhibitory activities with IC50 values of 26.6 ± 0.5 and 24.4 ± 5.6 µM, respectively. Compounds 7-10 showed significant inhibitory effects on TNFα-induced nuclear factor kappa B (NF-κB) transcriptional activity in a dose-dependent manner, with IC50 values ranging from 11.15 to 19.45 µM.

Peroxisome proliferator-activated receptor transactivational effects in HepG2 cells of cembranoids from the soft coral Lobophytum crassum Von Marenzeller.

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that regulate the expression of multiple genes involved in metabolic, anti-inflammatory, and developmental processes. This study evaluated the PPARs transactivational effects of thirteen cembranoid diterpenoids 1-13 from the soft coral Lobophytum crassum, using PPAR-responsive elements-luciferase reporter and GAL4-PPAR chimera assays. All isolated compounds activated the transcription of PPARs in a dose-dependent manner, with EC50 values ranging from 2.07 ± 1.73 to 130.20 ± 1.85 µM. Moreover, compounds 6-9 affected the transactivation of all three PPAR types, PPARα, γ, ß(δ), in a dose-dependent manner, with EC50 values in a ranging from 11.92 ± 1.23 to 122.50 ± 2.12 µM. These results provide a scientific rationale for further studies on the soft coral L. crassum and its diterpenoid constituents to develop medicinal products against inflammatory and metabolic diseases.