Rhodiola crenulata reduces ventricular arrhythmia through mitigating the activation of IL-17 and inhibiting the MAPK signaling pathway.

PURPOSE: Ventricular arrhythmia (VA) is related to inflammatory activity. Rhodiola crenulate (RC) and its main active component, salidroside, have been reported as anti-inflammatory agents. The aim of this study was to demonstrate the effect of RC and salidroside in preventing VA via the inhibition of IL-17 in an ischemic heart failure (HF) model. METHODS: Rabbit HF models were established by coronary artery ligation for 4 weeks. These rabbits were treated with RC (125, 250, 500 mg/kg) and salidroside (9.5 mg/kg) once every 2 days for 4 weeks. WBC, serum biochemistry, ECG, and the expression of CD4+ T cells were measured every 2 weeks. The mRNA and protein expressions of IL-17 were measured by real time-PCR, ELISA, and Western blotting after RC and salidroside treatment for 4 weeks. Open-chest epicardial catheter stimulation was performed for VA provocation. RESULTS: After RC and salidroside treatment in HF left ventricle, (1) the levels of WBC and CD4+ T cells decreased, (2) the expression of IL-17 and its downstream target genes, IL-6, TNF-α, IL-1ß, IL-8, and CCL20, reduced, (3) the level of NLRP3 inflammasome was decreased, (4) fibrosis and collagen production were significantly downregulated, (5) p38 MAPK and ERK1/2 phosphorylation were attenuated, (6) the inducibility of VA was decreased, and (7) the levels of Kir2.1, Nav1.5, NCX, PLB, SERCA2a and RyR were up-regulated. CONCLUSIONS: RC inhibited the expression of IL-17 and its downstream target genes that were mediated by activation of several MAPKs, which decreased the levels of fibrosis and apoptosis and suppressed VA.

Chronic Alcohol Consumption Exacerbates the Severity of Psoriasiform Dermatitis in Mice.

BACKGROUND: A relationship between alcohol consumption and psoriasis has been reported, but it is unclear whether alcohol consumption aggravates psoriasis. Here, we studied the effect of chronic ethanol (EtOH) consumption in the murine model of Aldara-induced psoriasiform dermatitis. METHODS: C57BL/6 mice received 5% EtOH in their drinking water for 10 weeks. Dermatitis was induced from weeks 9 to 10, by applying Aldara to the shaved patch of skin on the back. Inflammation was characterized by histological and transcriptomic analyses. RESULTS: EtOH consumption aggravated Aldara-induced dermatitis. The scales were more severe, epidermal thickening was more pronounced, and cutaneous expression of Th17-related cytokines was exacerbated. Control mice simply receiving EtOH displayed minimal cutaneous inflammation, characterized by epidermal infiltrates of T lymphocytes and the overexpression of IL-17A and the Th17-recruiting chemokine CCL20. In vitro studies showed that low concentrations of EtOH induce the expression of CCL20 by murine epidermal keratinocytes. CONCLUSION: Alcohol consumption leads to subliminar skin inflammation, which is revealed by the exacerbation of Aldara-induced experimental psoriasiform dermatitis, likely through Th17-type minimal skin inflammation. These results favor the systematic management of alcohol consumption in psoriatic patients.

The rheumatoid synovial environment alters fatty acid metabolism in human monocytes and enhances CCL20 secretion.

OBJECTIVES: Fatty acid oxidation (FAO) and glycolysis have been implicated in immune regulation and activation of macrophages. However, investigation of human monocyte intracellular metabolism in the context of the hypoxic and inflammatory rheumatoid arthritis (RA) synovium is lacking. We hypothesized that exposure of monocytes to the hypoxic and inflammatory RA environment would have a profound impact on their metabolic state, and potential to contribute to disease pathology. METHODS: Human monocytes were isolated from buffy coats and exposed to hypoxia. Metabolic profiling of monocytes was carried out by LC-MS metabolomics. Inflammatory mediator release after LPS or RA-synovial fluid (RA-SF) stimulation was analysed by ELISA. FAO was inhibited by etomoxir or enhanced with exogenous carnitine supplementation. Transcriptomics of RA blood monocytes and RA-SF macrophages was carried out by microarray. RESULTS: Hypoxia exacerbated monocyte-derived CCL20 and IL-1ß release in response to LPS, and increased glycolytic intermediates at the expense of carnitines. Modulation of carnitine identified a novel role for FAO in the production of CCL20 in response to LPS. Transcriptional analysis of RA blood monocytes and RA-SF macrophages revealed that fatty acid metabolism was altered and CCL20 increased when monocytes enter the synovial environment. In vitro analysis of monocytes showed that RA-SF increases carnitine abundance and CCL20 production in hypoxia, which was exacerbated by exogenous carnitine. CONCLUSION: This work has revealed a novel inflammatory mechanism in RA that links FAO to CCL20 production in human monocytes, which could subsequently contribute to RA disease pathogenesis by promoting the recruitment of Th17 cells and osteoclastogenesis.

Shikonin Inhibits Inflammatory Cytokine Production in Human Periodontal Ligament Cells.

Shikonin, which is derived from Lithospermum erythrorhizon, a herb used in traditional medicine, has long been considered to be a useful treatment for various diseases in traditional oriental medicine. Shikonin has recently been reported to have several pharmacological properties, e.g., it has anti-microbial, anti-tumor, and anti-inflammatory effects. The aim of this study was to examine whether shikonin is able to influence the production of interleukin (IL)-6, IL-8, and/or chemokine C-C motif ligand (CCL)20, which contribute to the pathogenesis of periodontal disease, in human periodontal ligament cells (HPDLC). The production levels of IL-6, IL-8, and CCL20 in HPDLC were determined using an ELISA. Western blot analysis was used to detect nuclear factor kappa B (NF-κB) pathway activation in HPDLC. Shikonin prevented IL-1ß- or tumor necrosis factor (TNF)-α-mediated IL-6, IL-8, and CCL20 production in HPDLC. Moreover, we found that shikonin suppressed the phosphorylation and degradation of inhibitor of kappa B-alpha (IκB-α) in IL-1ß- or TNF-α-stimulated HPDLC. These findings suggest that shikonin could have direct beneficial effects against periodontal disease by reducing IL-6, IL-8, and CCL20 production in periodontal lesions.

Ellagic acid modulates the expression of oral innate immune mediators: potential role in mucosal protection.

BACKGROUND: Ellagic acid (EA) found in various fruits such as pomegranates, blackberries, raspberries, strawberries, and walnuts has different pharmacological functions including antioxidant, antitumor, antiallergic, anti-inflammatory, antibacterial, and antiviral activities. It is not known, however, if EA could enhance mucosal innate immunity. Our goal was to determine the effects of EA on the expression of innate immune mediators produced by oral epithelial cells. METHODS: Culture of primary human gingival epithelial cells (HGEs) was performed in duplicate, and after the primary HGEs had been treated with EA at a concentration ranging from 12.5 to 100 µM for 18 h the cells and supernatants were harvested. The expression of innate immune mediators including human ß-defensin 2 (hBD2), secretory leukocyte protease inhibitor (SLPI), and various cytokines and chemokines was measured at both transcriptional and translational levels by using quantitative real-time PCR, ELISA, and Luminex assay. RESULTS: In the presence of EA, the expression of hBD2-and SLPI mRNA was 3.7-folds and 2.6-folds greater than untreated controls, respectively, and consistent with their secreted protein levels. For cytokines and chemokines, increased expression of RANTES, IL-2, and IL-1ß was found in response to EA. In contrast, EA decreased the expression of IL-6, IL-8, and TNF-α. CONCLUSIONS: This study demonstrated that oral innate immunity is affected by EA found in fruits. Thus, it may play some roles in mucosal innate immunity. The potential of EA for modulating the innate immune mediators may lead to developing a new topical agent to treat and/or prevent immune-mediated oral diseases.

Effects of interleukin-1ß and tumor necrosis factor-α on macrophage inflammatory protein-3α production in synovial fibroblast-like cells from human temporomandibular joints.

BACKGROUND: Interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) are key mediators of the intracapsular pathological conditions of the temporomandibular joint (TMJ). Therefore, the gene expression profiles in synovial fibroblast-like cells (SFCs) from patients with internal derangement of the TMJ were examined after they were stimulated with IL-1ß or TNF-α to determine which genes were altered. METHODS: Ribonucleic acid was isolated from SFCs after IL-1ß or TNF-α treatment. Gene expression profiling was performed using oligonucleotide microarray analysis. On the basis of the results of this assay, we investigated the kinetics of macrophage inflammatory protein-3α (MIP-3α) gene expression using PCR, and protein production in TMJ SFCs stimulated by IL-1ß or TNF-α using an ELISA. Inhibition experiments were performed with MAPK and NFκB inhibitors. SFCs were stimulated with IL-1ß or TNF-α after treatment with inhibitors. The MIP-3α levels were measured using an ELISA. RESULTS: Macrophage inflammatory protein-3α was the gene most upregulated by IL-1ß- or TNF-α stimulation. The mRNA and protein levels of MIP-3α increased in response to IL-1ß in a time-dependent manner. In contrast, during TNF-α stimulation, the MIP-3α mRNA levels peaked at 4 h, and the protein levels peaked at 8 h. In addition, the IL-1ß- and TNF-α-stimulated MIP-3α production was potently reduced by the MAPK and NFκB signaling pathway inhibitors. CONCLUSION: Interleukin-1ß and TNF-α increased the MIP-3α production in SFCs via the MAPK and NFκB pathways. These results suggest that the production of MIP-3α from stimulation with IL-1ß or TNF-α is one factor associated with the inflammatory progression of the internal derangement of the TMJ.

Innate immune responses of airway epithelium to house dust mite are mediated through beta-glucan-dependent pathways.

BACKGROUND: House dust mite (HDM) induces allergic asthma in sensitized individuals, although the mechanisms by which HDM is sensed and recognized by the airway mucosa, leading to dendritic cell (DC) recruitment, activation, and subsequent T(H)2-mediated responses, are unknown. OBJECTIVE: We sought to define the pathways by which HDM activates respiratory epithelium to induce allergic airway responses. METHODS: Using a human airway epithelial cell line (16HBE14o-), we studied secretion of the DC chemokine CCL20 after exposure to HDM or other allergens, investigated components of the HDM responsible for the induction of chemokine release, and examined activation of signaling pathways. Central findings were also confirmed in primary human bronchial cells. RESULTS: We demonstrate that exposure of airway epithelium to HDM results in specific and rapid secretion of CCL20, a chemokine attractant for immature DCs. The induction of CCL20 secretion is dose and time dependent and quite specific to HDM because other allergens, such as ragweed pollen and cockroach antigen, fail to significantly induce CCL20 secretion. Induction of CCL20 secretion is not protease or Toll-like receptor 2/4 dependent but, interestingly, relies on beta-glucan moieties within the HDM extract, as evidenced by the ability of other beta-glucans to competitively inhibit its secretion and by the fact that disruption of these structures by treatment of HDM with beta-glucanase significantly reduces subsequent chemokine secretion. CONCLUSION: Taken together, our results describe a novel mechanism for specific pattern recognition of HDM-derived beta-glucan moieties, which initiates allergic airway inflammation and, through recruitment of DCs, might link innate pattern recognition at the airway surface with adaptive immune responses.