Phyllostachys nigra Munro var alleviates inflammatory chemokine expression and DNCB-induced atopic-like dermatitis in BALB/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllostachys nigra (PN) is an herbal medicine that originates from the inner bark of Phyllostachys nigra Munro var. henosis Stapf or Phyllostachys bambusoides Siebold et Zuccarini. It has long been used to relieve fever and to treat diarrhea and inflammation. PN has been shown to possess inhibitory effects on pneumonia, intestinal inflammation, tumors, and fatigue. However, its potential efficacy in the treatment of atopic dermatitis (AD) has not been extensively studied or reported.

AIM OF THE STUDY

The objective of this research was to investigate the impact of PN on HaCaT and HMC-1 cells, as well as its potential in an experimental model of AD induced by 1-chloro-2,4-dinitrobenzene (DNCB).

METHODS

We analyzed the anti-inflammatory efficacy of PN in HaCaT cells and HMC-1 cells using ELISA and PCR, and investigated invasion of inflammatory cell, change of dermis and epidermis, and the SCORAD index in AD-like mice model. We also measured the MAPK signaling pathway using the dorsal tissue of mice.

RESULTS

Our results show that PN reduced the expressions of TARC, GM-CSF, TNF-α, MCP-1, and IL-6 in vitro. PN also decreased the SCORAD index, thickening of epidermis and dermis, and inhibited the invasions of mast cells and eosinophils as well as CD4+ T and CD8+ T cells. Furthermore, PN suppressed the level of IgE and IL-6, and also inhibited the MAPK phosphorylation in the dorsal skin.

CONCLUSION

These results demonstrate that PN could be an effective alternative medicine for allergic inflammatory disease.

Effects of Deacetylasperulosidic Acid on Atopic Dermatitis through Modulating Immune Balance and Skin Barrier Function in HaCaT, HMC-1, and EOL-1 Cells

The medicinal plant noni (Morinda citrifolia) is widely dispersed throughout Southeast Asia, the Caribbean, and Australia. We previously reported that fermented Noni could alleviate atopic dermatitis (AD) by recovering Th1/Th2 immune balance and enhancing skin barrier function induced by 2,4-dinitrochlorobenzene. Noni has a high deacetylasperulosidic acid (DAA) content, whose concentration further increased in fermented noni as an iridoid constituent. This study aimed to determine the anti-AD effects and mechanisms of DAA on HaCaT, HMC-1, and EOL-1 cells. DAA inhibited the gene expression and secretion of AD-related cytokines and chemokines including interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-25, IL-33, thymic stromal lymphopoietin, tumor necrosis factor-alpha, monocyte chemoattractant protein-1, thymus and activation-regulated chemokine, macrophage-derived chemokine, and regulated upon activation, normal T cell expressed and secreted, in all cells, and inhibited histamine release in HMC-1 cells. DAA controlled mitogen-activated protein kinase phosphorylation levels and the translocation of nuclear factor-kappa light chain enhancer of activated B cells into the nucleus by inhibiting IκBα decomposition in all the cells. Furthermore, DAA increased the expression of proteins involved in skin barrier functions such as filaggrin and involucrin in HaCaT cells. These results confirmed that DAA could relieve AD by controlling immune balance and recovering skin barrier function.

Effect of Cone of Pinus densiflora on DNCB-Induced Allergic Contact Dermatitis-Like Skin Lesion in Balb/c Mice

Cone of Pinus densiflora (CP), or Korean red pinecone, is a cluster of Pinus densiflora fruit. CP has also been verified in several studies to have anti-oxidation, anti-fungal, anti-bacterial, and anti-melanogenic effects. However, anti-inflammatory effects have not yet been confirmed in the inflammatory responses of pinecones to allergic contact dermatitis. The purpose of this study is to prove the anti-inflammatory effect of CP on allergic contact dermatitis (ACD) in vitro and in vivo. CP inhibited the expression of TSLP, TARC, MCP-1, TNF-α, and IL-6 in TNF-α/IFN-γ-stimulated HaCaT cells and MCP-1, GM-CSF, TNF-α, IL-6, and IL-8 in PMACI (phorbol-12-myristate-13-acetate plus A23187)-stimulated HMC-1 cells. CP inhibited the phosphorylation of mitogen-activated protein kinase (MAPKs), as well as the translocation of NF-κB on TNF-α/IFN-γ stimulated in HaCaT cells. In vivo, CP decreased major symptoms of ACD, levels of IL-6 in skin lesion, thickening of the epidermis and dermis, infiltration of eosinophils and mast cells, and the infiltration of CD4⁺ T cells and CD8⁺ T cells. This result suggests that CP represents a potential alternative medicine to ACD for diseases such as chronic skin inflammation.

Mast Cell and Basophil Cell Lines: A Compendium

Mast cells and basophils play a crucial role during type I hypersensitivity reactions. However, despite efforts to elucidate their role in the pathogenesis of allergy and inflammation, our understanding of MC and basophil biology is still relatively scarce. The practical difficulty in obtaining a sufficient number of purified primary cells from biological samples has slowed down the process of reaching a full understanding of the physiological role of these functionally similar cell types. The establishment of several immortalized cell lines has been a useful tool to establish and perform sophisticated laboratory protocols that are impractical using primary cells. Continuous cell lines have been extensively used to investigate allergen/IgE-mediated cell activation, to elucidate the degranulation dynamics, to investigate structural and functional properties of the high-affinity receptor (FcεRI), and to test cell-stabilizing compounds. In this chapter, we review the most widely used and better-characterized MC and basophil cell lines, highlighting their advantages and drawbacks. It must be pointed out, however, that while cell lines represent a useful in vitro tool due to their easy manipulability and reduced culture costs, they often show aberrant characteristics which are not fully representative of primary cell physiology; results obtained with such cells therefore must be interpreted with due care.

Geraniol suppresses proinflammatory mediators in phorbol 12-myristate 13-acetate with A23187-induced HMC-1 cells

Background

Geraniol is a monoterpene alcohol that has anti-fungal, anti-cancer and anti-nociceptive properties, but its anti-allergic rhinitis (AR) property is unclear.

Methods

In this study, the anti-inflammatory role and its possible mechanisms of geraniol in human mast cell line (HMC-1) cells stimulated by inflammatory trigger phorbol 12-myristate 13-acetate plus A23187 (PMACI), as well as in ovalbumin (OVA)-induced AR mice models were investigated.

Results

PMACI results in a significant increase in the production of proinflammatory cytokines, such as TNF-α, IL-1β, MCP-1, IL-6 and as well as histamine. Geraniol was found to inhibit both TNF-α, IL-1β and IL-6 protein and mRNA expressions at concentrations of 40, 80, 160 μM. In OVA-induced AR models, geraniol treatment was able to suppress AR biomarkers (OVA-specific IgE and IL-1β as well as histamine) and nasal rub scores. Interestingly, p38, a member of the mitogen-activated protein kinase (MAPK) signaling family, was found to be increasingly hypophosphorylated as geraniol dose was increased. Similar decreases in the nuclear level of p65, a member of the nuclear factor kappa B (NF-κB) signaling pathway, were also observed.

Conclusion

Our data highlights that the anti-inflammatory properties of geraniol on AR-related markers in activated HCM-1 cells and OVA-induced AR models may be mediated through the regulation of the MAPK/NF-κB signaling pathway.

Silencing of H4R inhibits the production of IL-1β through SAPK/JNK signaling in human mast cells

CONTEXT

Mast cell (MC) activation through H4R releases various inflammatory mediators which are associated with allergic asthma.

OBJECTIVES

To investigate the siRNA-mediated gene silencing effect of H4R on human mast cells (HMCs) functions and the activation of stress-activated protein kinases (SAPK)/jun amino-terminal kinases (JNK) signaling pathways for the release of ineterleukin-1β (IL-1β) in HMCs.

MATERIALS AND METHODS

H4R expression was analyzed by RT-PCR and western blotting in human mast cell line-1 (HMC-1) cells and H4RsiRNA transfected cells. The effect of H4RsiRNA and H4R-antagonist on H4R mediated MC functions such as intracellular Ca²⁺ release, degranulation, IL-6 and IL-1β release, and the activation SAPK/JNK signaling pathways were studied. HMC-1 cells were stimulated with 10 μM of histamine (His) and 4-methylhistamine (4-MH) and pretreated individually with H4R-antagonist JNJ7777120 (JNJ), histamine H1 receptor (H1R)-antagonist mepyramine, and signaling molecule inhibitors SP600125 (SP) and Bay117082.

RESULTS

We found that the HMC-1 cells expressed H4R and H4RsiRNA treatment down regulated the H4R expression in HMC-1 cells. Both His and 4-MH induced the intracellular Ca²⁺ release and degranulation whereas; H4R siRNA and JNJ inhibited the effect. Furthermore, the activation of H4R caused the phosphorylation of SAPK/JNK pathways. H4R gene silencing and pretreatment with SP and JNJ decreased His and 4-MH induced phosphorylation of SAPK/JNK. We found that the activation of H4R caused the release of IL-1β (124.22 pg/ml) and IL-6 (122.50 pg/ml) on HMC-1 cells. Whereas, SAPK/JNK inhibitor (68.36 pg/ml) inhibited the H4R mediated IL-1β release.

CONCLUSIONS

Taken together, the silencing of H4R inhibited the H4R mediated MC functions and SAPK/JNK phosphorylation. Furthermore, the H4R activation utilized SAPK/JNK signaling pathway for IL-1β release in HMC-1 cells.

Spiroketones and a Biphenyl Analog from Stems and Leaves of Larrea nitida and Their Inhibitory Activity against IL-6 Production

Bioactivity-guided fractionation for the stems of leaves of Larrea nitida Cav., using interleukin-6 (IL-6) inhibitory assay in human mast cells (HMC-1), led to the isolation of three new compounds with an unprecedented skeleton in nature (1–3) and three known compounds (4–6). Their structures were elucidated through extensive spectroscopic analysis. The three new compounds were elucidated as two new spiroketones, nitidaones A (1), and B (2) and one new biphenyl analog, nitidaol (3). The known compounds were identified as nordihydroguaiaretic acid (4), 7,3′,4′-tri-O-methylquercetin (5) and ayanin (6). All the isolates were tested for their inhibitory activity against IL-6 production in HMC-1 cells. Of them, compounds 1, 3–6 showed potent anti-inflammatory activity, with IC₅₀ values of 12.8, 17.5, 14.9, 22.9, and 17.8 µM, respectively.

Exosomes purified from a single cell type have diverse morphology

Extracellular vesicles (EVs) are produced by all known organisms and are important for cell communication and physiology. Great morphological diversity has been described regarding EVs found in body fluids such as blood plasma, breast milk, and ejaculate. However, a detailed morphological analysis has never been performed on exosomes when purified from a single cell type. In this study we analysed and quantified, via multiple electron microscopy techniques, the morphology of exosomes purified from the human mast cell line HMC-1. The results revealed a wide diversity in exosome morphology, suggesting that subpopulations of exosomes with different and specific functions may exist. Our findings imply that a new, more efficient way of defining exosome subpopulations is necessary. A system was proposed where exosomes were classified into nine different categories according to their size and shape. Three additional morphological features were also found in exosomes regardless of their morphological classification. These findings show that exosomes purified from a single cell line are also morphologically diverse, similar to previous observations for EVs in body fluids. This knowledge can help to improve the interpretation of experimental results and widen our general understanding of the biological functions of exosomes.

C-kit mutations determine dasatinib mechanism of action in HMC-1 neoplastic mast cells: dasatinib differently regulates PKCδ translocation in HMC-1(560) and HMC-1(560,816) cell lines

PURPOSE

The second generation of tyrosine kinase inhibitors is a group of compounds that inhibit c-kit receptor activity and therefore widely used in the treatment of mastocytosis. In this research, the relationship between the mechanism of action of tyrosine kinase inhibitors and protein kinase C is investigated in HMC-1(560) or HMC-1(560,816) cell lines.

RESULTS

From all the tyrosine kinase inhibitors tested, nilotinib is the compound that has the highest cytotoxic effect against HMC-1(560) mast cell line, while midostaurin is the most potent in HMC-1(560,816). Moreover, an increase on histamine release is observed after protein kinase C activation either in HMC-1(560) or HMC-1(560,816) cells. Furthermore, dasatinib increases histamine release in both mast cell lines, which could be related with the secondary reactions previously described in dasatinib-treated patients. Dasatinib also induces Ca(2+)-dependent protein kinase C isoforms translocation from the cytosol to the membrane, whereas protein kinase Cδ is translocated from the cytosol to the nucleus in the HMC-1(560,816) cell line, but not in HMC-1(560) cells.

CONCLUSION

Results obtained demonstrate that dasatinib induces an important cytotoxic effect in both HMC-1 cell lines and differently regulates protein kinase Cδ in HMC-1(560) and HMC-1(560,816) cells. Finally, our results confirm that PKCδ is an essential target for dasatinib.

Different role of cAMP pathway on the human mast cells HMC-1(560) and HMC-1(560,816) activation

HMC-1 are inflammatory cells that release vasoactive substances such as histamine. These cells have the c-kit receptor permanently activated in the membrane due to mutations in the proto-oncogene c-kit: Val-560 → Gly and Asp-816 → Val. Thus, there are two known cellular lines: HMC-1(560) and HMC-1(560,816) . These mutations are involved in a disease called mastocitosys. In the present paper both lines were used to study the influence of cAMP/PKA/PDEs pathway on the histamine release and Ca(2+) signaling since this pathway is often involved in these process. For this, the cells were preincubated with cAMP/PKA/PDEs modulators such as dibutyryl cAMP (dbcAMP), forskolin, H89, rolipram, IBMX, or imidazole and then stimulated with ionomycin. When cells were stimulated with agents that increase cAMP levels, the histamine release was not modified in HMC-1(560) but decreased in HMC-1(560,816) cells. The same happened when PKA was blocked. Furthermore, PDEs role on histamine release was independent of cAMP in HMC-1(560) cells and possibly also in HMC-1(560,816) cells. By contrast, the modulation of PKA and PDEs together changed the response in both cellular lines, therefore a relationship between them was suggested. All these modulatory effects on histamine release are Ca(2+) -independent. On the other hand, the effect of c-kit modulation on the cAMP/PKA/PDEs pathway was also checked. This receptor was blocked with STI571 (imatinib) and BMS-354825 (dasatinib), but only the last one caused a decrease in the cellular response to ionomycin. This article demonstrates for the first time than the cAMP/PKA/PDEs pathway is involved in the activation of HMC-1(560) and HMC-1(560,816) cells.

PKC potentiates tyrosine kinase inhibitors STI571 and dasatinib cytotoxic effect

AIM

The aim of the present study was to determine the relationship between the tyrosine kinase inhibitors, STI571 and dasatinib effects and protein kinase C (PKC) status in HMC-1(560) and HMC-1(560,816) cell lines.

MATERIAL AND METHODS

Viability results were obtained by two different methods: MTT and a flow cytometry with Annexin V-FITC/PI double-staining protocol. The lipid-based transfection method was used to silence PKC.

RESULTS

Long-term PKC activation induces apoptosis in both HMC-1 cell lines. Moreover, PKC activation potentiates STI571 and dasatinib cytotoxic effects in HMC-1(560) and HMC-1(560,816) cells, respectively, by increasing necrotic populations. To investigate this PKC effect, the role of PKCδ, an isoform intimately related with apoptotic cell death, was studied. The results obtained evidence that either STI571 or dasatinib apoptotic cell death are PKCδ-dependent. Particularly, STI571 showed less dependence to PKCδ than dasatinib.

CONCLUSION

PKCδ modulation is essential and determines mastocytosis treatment effectiveness, since STI571 and dasatinib effects are PKCδ-dependent.

Mast cell adenosine receptors function: a focus on the a3 adenosine receptor and inflammation

Adenosine is a metabolite, which has long been implicated in a variety of inflammatory processes. Inhaled adenosine provokes bronchoconstriction in asthmatics or chronic obstructive pulmonary disease patients, but not in non-asthmatics. This hyper responsiveness to adenosine appears to be mediated by mast cell activation. These observations have marked the receptor that mediates the bronchoconstrictor effect of adenosine on mast cells (MCs), as an attractive drug candidate. Four subtypes (A1, A2a, A2b, and A3) of adenosine receptors have been cloned and shown to display distinct tissue distributions and functions. Animal models have firmly established the ultimate role of the A3 adenosine receptor (A3R) in mediating hyper responsiveness to adenosine in MCs, although the influence of the A2b adenosine receptor was confirmed as well. In contrast, studies of the A3R in humans have been controversial. In this review, we summarize data on the role of different adenosine receptors in mast cell regulation of inflammation and pathology, with a focus on the common and distinct functions of the A3R in rodent and human MCs. The relevance of mouse studies to the human is discussed.