Honokiol suppresses TNF-α-induced neutrophil adhesion on cerebral endothelial cells by disrupting polyubiquitination and degradation of IκBα.

Adhesion molecules expressed on cerebral endothelial cells (ECs) mediate leukocyte recruitment and play a significant role in cerebral inflammation. Increased levels of adhesion molecules on the EC surface induce leukocyte infiltration into inflammatory areas and are thus hallmarkers of inflammation. Honokiol, isolated from the Chinese medicinal herb Magnolia officinalis, has various pharmacological activities, including anti-inflammatory effects, yet the nature of honokiol targeting molecules remains to be revealed. Here, we investigated the inhibitory effect of honokiol on neutrophil adhesion and vascular cell adhesion molecule-1 (VCAM-1) expression, which underlie its molecular target, and mechanisms for inactivating nuclear factor κ enhancer binding protein (NF-κB) in mouse cerebral ECs. Honokiol inhibited tumour necrosis factor-α (TNF-α)-induced neutrophil adhesion and VCAM-1 gene expression in cerebral ECs. The inflammatory transcription factor NF-κB was downregulated by honokiol. Honokiol significantly blocked TNF-α-induced NF-κB p65 nuclear translocation and degradation of the proteasome-dependent inhibitor of NF-κB α (IκBα). From docking model prediction, honokiol directly targeted the ubiquitin-ubiquitin interface of Lys48-linked polychains. Moreover, honokiol prevented the TNF-α-induced Lys48-linked polyubiquitination, including IκBα-polyubiquitin interaction. Honokiol has protective anti-inflammatory effects on TNF-α-induced neutrophil adhesion and VCAM-1 gene expression in cerebral ECs, at least in part by directly inhibiting ubiquitination-mediated IκBα degradation and then preventing NF-κB nuclear translocation.

Expression and immunoaffinity purification of recombinant soluble human GPR56 protein for the analysis of GPR56 receptor shedding by ELISA.

GPR56 is a multi-functional adhesion-class G protein-coupled receptor involved in biological systems as diverse as brain development, male gonad development, myoblast fusion, hematopoietic stem cell maintenance, tumor growth and metastasis, and immune-regulation. Ectodomain shedding of human GPR56 receptor has been demonstrated previously, however the quantitative detection of GPR56 receptor shedding has not been investigated fully due to the lack of appropriate assays. Herein, an efficient system of expression and immune-affinity purification of the recombinant soluble extracellular domain of human GPR56 (sGPR56) protein from a stably transduced human melanoma cell line was established. The identity and functionality of the recombinant human sGPR56 protein were verified by Western blotting and mass spectrometry, and ligand-binding assays, respectively. Combined with the use of two recently generated anti-GPR56 monoclonal antibodies, a sensitive sandwich ELISA assay was successfully developed for the quantitative detection of human sGPR56 molecule. We found that GPR56 receptor shedding occurred constitutively and was further increased in activated human melanoma cells expressing endogenous GPR56. In conclusion, we report herein an efficient system for the production and purification of human sGPR56 protein for the establishment of a quantitative ELISA analysis of GPR56 receptor shedding.

Intracellular glutathione depletion by oridonin leads to apoptosis in hepatic stellate cells.

Proliferation of hepatic stellate cells (HSCs) plays a key role in the pathogenesis of liver fibrosis. Induction of HSC apoptosis by natural products is considered an effective strategy for treating liver fibrosis. Herein, the apoptotic effects of 7,20-epoxy-ent-kaurane (oridonin), a diterpenoid isolated from Rabdosia rubescens, and its underlying mechanisms were investigated in rat HSC cell line, HSC-T6. We found that oridonin inhibited cell viability of HSC-T6 in a concentration-dependent manner. Oridonin induced a reduction in mitochondrial membrane potential and increases in caspase 3 activation, subG1 phase, and DNA fragmentation. These apoptotic effects of oridonin were completely reversed by thiol antioxidants, N-acetylcysteine (NAC) and glutathione monoethyl ester. Moreover, oridonin increased production of reactive oxygen species (ROS), which was also inhibited by NAC. Significantly, oridonin reduced intracellular glutathione (GSH) level in a concentration- and time-dependent fashion. Additionally, oridonin induced phosphorylations of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK). NAC prevented the activation of MAPKs in oridonin-induced cells. However, selective inhibitors of MAPKs failed to alter oridonin-induced cell death. In summary, these results demonstrate that induction of apoptosis in HSC-T6 by oridonin is associated with a decrease in cellular GSH level and increase in ROS production.

Matrine attenuates allergic airway inflammation and eosinophil infiltration by suppressing eotaxin and Th2 cytokine production in asthmatic mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Matrine has been isolated from Sophora flavescens, and found to show anti-inflammatory effects in macrophages and anti-cachectic effects in hepatomas. The present study investigated whether matrine suppressed eosinophil infiltration and airway hyperresponsiveness (AHR) in mice, and decreased the inflammatory response of tracheal epithelial cells. MATERIALS AND METHODS: BALB/c mice were sensitized and challenged with ovalbumin to induce allergic asthma in mice. These asthmatic mice were given various doses of matrine by intraperitoneal injection. Additionally, activated human tracheal epithelial cells (BEAS-2B cells) were treated with matrine, and evaluated for levels of proinflammatory cytokines and chemokines. RESULTS: We found that matrine significantly decreased AHR, and suppressed goblet cell hyperplasia, eosinophil infiltration, and inflammatory response in the lung tissue of asthmatic mice. Matrine also reduced the levels of Th2 cytokines and chemokines in bronchoalveolar lavage fluid, and suppressed OVA-IgE production in serum. Furthermore, matrine treatment of activated BEAS-2B cells decreased production of proinflammatory cytokines and eotaxins, as well as suppressed ICAM-1 expression and thus adhesion of eosinophils to inflammatory BEAS-2B cells in vitro. CONCLUSIONS: Our findings suggest that matrine can improve allergic asthma in mice, and therefore has potential therapeutic potential in humans.

Effect of dehydroepiandrosterone on atopic dermatitis-like skin lesions induced by 1-chloro-2,4-dinitrobenzene in mouse.

BACKGROUND: Th2 cells are overexpressed in the skin and serum of atopic dermatitis (AD) patients. Previously, we found that dehydroepiandrosterone (DHEA) decreased eosinophil infiltration in asthmatic mice through the suppression of Th2-associated cytokines. Therefore, we hypothesized that DHEA might improve the symptoms of AD syndrome. OBJECTIVE: In this study, we evaluated the symptom improvement and anti-inflammatory response that result from the modulation of immunity by DHEA modulated in AD-like mice. METHODS: Female BALB/c mice were sensitized and challenged with 1-chloro-2,4-dinitrobenzene. On days 14-29 after sensitization, mice were treated with cutaneous (skin smear) or oral administration of DHEA. In addition, human keratinocyte (HaCat) cells were used to evaluate the effect of DHEA on the in vitro production of proinflammatory cytokines and chemokines. RESULTS: Both cutaneous and oral DHEA were able to decrease ear swelling and skin inflammation in AD-like mice. DHEA also attenuated eosinophil and mast cell infiltration into ear and skin tissue. Additionally, Th2-associated cytokines were inhibited in splenocyte culture, and suppressed the levels of IgE and interleukin 4 in serum. Oral and cutaneous administration of DHEA reduced the inflammatory response, as evidenced by AD-like skin lesions, in a similar manner. DHEA significantly reduced inflammatory cytokines and chemokines through the nuclear factor-κB and mitogen-activated protein kinases pathways in tumor necrosis factor-α activated HaCat cells. CONCLUSION: DHEA ameliorates AD-like mouse skin inflammation and reduces eosinophil and mast cell infiltration by reducing the production of Th2-associated cytokines and chemokines.

Proteomic analysis of plasma to reveal the impact of short-term etanercept therapy in pediatric patients with enthesitis-related arthritis: a case report.

In a variety of countries, juvenile idiopathic arthritis (JIA) is the most common cause of chronic arthritis in childhood, yet its etiology is still unknown. In recent years, etanercept, an effective inhibitor of tumor necrosis factor alpha (TNF-alpha), was used as an alternative in certain oligoarticular JIA patients resistant to conventional nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), and corticosteroid therapies, and it resulted in sustained improvement in JIA symptoms. This pilot study explores the alterations of specific panels of cytokines and protein profiles in plasma for two Taiwanese pediatric cases with diagnosed enthesitis-related arthritis (ERA), a type of JIA. The patients were studied before and after taking etanercept alone, using a high-content screening approach employing membrane-based human cytokine antibody microarray and the conventional two-dimensional gel electrophoresis (2-DE) proteomic technique. Specifically, 2-DE in combination with mass spectrometry (MALDI-MS) revealed the functional roles of plasma proteins associated with the regulation of immune responses during short-term etanercept treatment of children with ERA. Our study shows that this biotherapy improved clinical ERA manifestations through the regulation of inflammatory mediators, including several cytotoxic cellular cytokines (IL-2/IFN-g), chemokines (MCP-1), and growth factors (GRO) that affect the expression of specific acute phase proteins such as haptoglobins, immunoglobulin A, and fibrinogen-gamma chain. Meanwhile, an up-regulation of antithrombin chain I, vitamin-D binding protein (VDBP), and the various apolipoproteins was also observed after the administration of etanercept in both studied children. These results may be interpreted as the relevant predictive biomarkers of therapeutic responses to etanercept. They suggest that etanercept, which is still rarely used in Taiwan, is a viable treatment for JIA patients, without adverse health effects and increased risk of secondary infections.

Effects of Agaricus blazei Murill extract on immune responses in normal BALB/c mice.

Agaricus blazei Murill (ABM) has shown particularly strong results in treating and preventing cancer and has also traditionally been used as a food source in Brazil. However, the exact immune responses regarding the phagocytosis of macrophage and, the activity of natural killer (NK) cells in normal mice after exposure to ABM extract was unclear. The goal of this study was to investigate whether or not ABM extract can promote immune responses in normal BALB/c mice. BALB/c mice were treated with different doses of ABM extract for different time periods. The results indicated that ABM extract significantly promoted the proliferation of splenocytes both in vitro and in vivo. ABM extract promoted the levels of interleukein-6 (IL-6) and, interferon-gamma (IFN-gamma) but reduced the levels of IL-4 in vitro and in vivo. The percentage of macrophages with phagocytosis after ABM extract treatment increased and these effects were of dose-dependent manners, both in vitro and in vivo. YAC-1 target cells were killed by NK cells from the mice after treatment with ABM extract at 3 and 6 mg/kg/day for up to 14 days at target cell ratios of 25:1 and 50:1. Taken together, these results show that ABM extract promoted immunomodulations in normal BALB/c mice in vitro and in vivo.

Characterization of plasma protein profiles from patients with neurofibromatosis I.

BACKGROUND: Neurofibromatosis type I (NF1) is a common autosomal dominant disorder, affecting approximately one in every 3500 individuals. Early diagnosis of NF1 can be ambiguous, and clinical symptoms are diverse. We compared plasma protein profiles between normal controls and NF1 patients for yielding important insights into the mechanisms underlying NF1 related tumor formation and diagnostic biomarkers to classify the diverse clinical symptoms. METHODS: MALDI-TOF mass spectrometry was used to identify plasma proteins. Prior to that, a micro-solution isoelectric focusing (microsol-IEF) pre-fractionation combined with two-dimensional gel electrophoresis (2-DE) using the narrow pH range strip was applied to enhance the resolution and sensitivity. RESULTS: There was a significant increase in fibrinogen level in patients with NF1. This increase in fibrinogen expression was subsequently confirmed by Western blotting assay. Furthermore, the effect of fibrinogen on cell growth was tested on PC12 cells. CONCLUSION: Fibrinogen is the central protein associated with angiogenesis; a process which modulates tumor growth, the up-regulation of fibrinogen may help explain the development of neurofibromas in NF1 patients.

Regulation of fibronectin by thyroid hormone receptors.

Thyroid hormones regulate growth, development, differentiation, and metabolic processes by interacting with and activating thyroid hormone receptors and associated pathways. We investigated the triiodothyronine (T3) modulation of gene expression, in human hepatocellular carcinoma cell lines, via a PCR-based cDNA subtraction method. Here we present further data on one of the T3-upregulated genes, fibronectin (FN). We demonstrate that the induction of FN protein expression by T3 in TRalpha1 and TRbeta1 over-expressing cells was time and dose-dependent at the mRNA and protein levels. Blockade of protein synthesis by cycloheximide almost completely inhibited the concomitant induction of FN mRNA by T3, indicating that T3 indirectly regulates FN. Furthermore, nuclear-run on and FN promoter assay clearly can specifically increase the number of FN transcriptional demonstrated that the presence of T3 initiations. In addition, we further confirmed that the up-regulation of FN by T3 was mediated, at least in part, by transforming growth factor-beta (TGF-beta), because the induction of FN was blocked in a dose-dependent manner by the addition of TGF-beta neutralizing antibody. In an effort to elucidate the we demonstrated the involvement of the signaling pathways involved in the activation of FN by T3, mitogen activated protein kinase/c-Jun N-terminal kinase/p38 MAPK (MAPK/JNK/p38) pathway. Although T3 induces the expression of TGF-beta, neither wild-type nor dominant-negative Smad3 or Smad4 over-expression affected the activation of FN by T3. Thus, we demonstrate that T3 regulates FN gene expression indirectly at the transcriptional level, with the participation of the MAPK/JNK/p38 pathway and the TGF-beta signaling pathway but independent of Smad3/4.

P53 is a regulator of the metastasis suppressor gene Nm23-H1.

p53, a tumor suppressor gene involved in the G1 cell cycle checkpoint, is also the most frequently mutated gene in human cancer. In addition, p53 modifies the ability of tumor cells to metastasize. The metastasis-associated gene Nm23-H1, which encodes an 18-kDa nucleoside diphosphate kinase, was previously identified in cells with low metastatic potential. Although p53 and Nm23-H1 proteins play an important part in regulating the progression of cancer, any functional relationship between these two proteins is currently unknown. Here we report an association between p53 levels and expression of the Nm23-H1 gene. Our data indicate that wild-type (wt) p53 upregulated the expression of Nm23-H1 at protein and mRNA levels in MCF-7 and J7B cells. This capacity of wt p53 to regulate expression of Nm23-H1 was not only dependent on the endogenous but also the exogenous origin of p53, and could not be reproduced with mutant p53. Subsequently, the invasive ability of MCF-7 and J7B cells was suppressed upon induction of the Nm23-H1 protein by p53. In contrast, increased levels of p53 downregulated the expression of Nm23-H1 at the protein and mRNA levels in RKO and H1299 cells and, as a consequence, increased the invasive ability of both cell types. Thus, our results implicated the differential regulation of Nm23-H1 by p53 in different cell types as an important component in the molecular mechanisms of tumor metastasis.