The Hyaluronic Acid-HDAC3-miRNA Network in Allergic Inflammation.

We previously reported the anti-allergic effect of high molecular weight form of hyaluronic acid (HMW-HA). In doing so, HA targets CD44 and inhibits FcεRI signaling and cross-talk between epidermal growth factor receptor (EGFR) and FcεRI. We previously reported the role of histone deacetylases (HDACs) in allergic inflammation and allergic inflammation-promoted enhanced tumorigenic potential. We reported regulatory role of HA in the expression of HDAC3. In this review, we will discuss molecular mechanisms associated with anti-allergic effect of HA in relation with HDACs. The role of microRNAs (miRNAs) in allergic inflammation has been reported. We will also discuss the role of miRNAs in allergic inflammation in relation with HA-mediated anti-allergic effects.

MicroRNA-26a/-26b-COX-2-MIP-2 Loop Regulates Allergic Inflammation and Allergic Inflammation-promoted Enhanced Tumorigenic and Metastatic Potential of Cancer Cells.

Cyclooxgenase-2 (COX-2) knock-out mouse experiments showed that COX-2 was necessary for in vivo allergic inflammation, such as passive cutaneous anaphylaxis, passive systemic anaphylaxis, and triphasic cutaneous allergic reaction. TargetScan analysis predicted COX-2 as a target of miR-26a and miR-26b. miR-26a/-26b decreased luciferase activity associated with COX-2-3'-UTR. miR-26a/-26b exerted negative effects on the features of in vitro and in vivo allergic inflammation by targeting COX-2. ChIP assays showed the binding of HDAC3 and SNAIL, but not COX-2, to the promoter sequences of miR-26a and miR-26b. Cytokine array analysis showed that the induction of chemokines, such as MIP-2, in the mouse passive systemic anaphylaxis model occurred in a COX-2-dependent manner. ChIP assays showed the binding of HDAC3 and COX-2 to the promoter sequences of MIP-2. In vitro and in vivo allergic inflammation was accompanied by the increased expression of MIP-2. miR-26a/-26b negatively regulated the expression of MIP-2. Allergic inflammation enhanced the tumorigenic and metastatic potential of cancer cells and induced positive feedback involving cancer cells and stromal cells, such as mast cells, macrophages, and endothelial cells. miR-26a mimic and miR-26b mimic negatively regulated the positive feedback between cancer cells and stromal cells and the positive feedback among stromal cells. miR-26a/-26b negatively regulated the enhanced tumorigenic potential by allergic inflammation. COX-2 was necessary for the enhanced metastatic potential of cancer cells by allergic inflammation. Taken together, our results indicate that the miR26a/-26b-COX-2-MIP-2 loop regulates allergic inflammation and the feedback relationship between allergic inflammation and the enhanced tumorigenic and metastatic potential.

Transglutaminase II/microRNA-218/-181a loop regulates positive feedback relationship between allergic inflammation and tumor metastasis.

The molecular mechanism of transglutaminase II (TGaseII)-mediated allergic inflammation remains largely unknown. TGaseII, induced by antigen stimulation, showed an interaction and co-localization with FcϵRI. TGaseII was necessary for in vivo allergic inflammation, such as triphasic cutaneous reaction, passive cutaneous anaphylaxis, and passive systemic anaphylaxis. TGaseII was necessary for the enhanced metastatic potential of B16F1 melanoma cells by passive systemic anaphylaxis. TGaseII was shown to be a secreted protein. Recombinant TGaseII protein increased the histamine release and ß-hexosaminidase activity, and enhanced the metastatic potential of B16F1 mouse melanoma cells. Recombinant TGaseII protein induced the activation of EGF receptor and an interaction between EGF receptor and FcϵRI. Recombinant TGaseII protein displayed angiogenic potential accompanied by allergic inflammation. R2 peptide, an inhibitor of TGaseII, exerted negative effects on in vitro and in vivo allergic inflammation by regulating the expression of TGaseII and FcϵRI signaling. MicroRNA (miR)-218 and miR-181a, decreased during allergic inflammation, were predicted as negative regulators of TGaseII by microRNA array and TargetScan analysis. miR-218 and miR-181a formed a negative feedback loop with TGaseII and regulated the in vitro and in vivo allergic inflammation. TGaseII was necessary for the interaction between mast cells and macrophages during allergic inflammation. Mast cells and macrophages, activated during allergic inflammation, were responsible for the enhanced metastatic potential of tumor cells that are accompanied by allergic inflammation. In conclusion, the TGaseII/miR-218/-181a feedback loop can be employed for the development of anti-allergy therapeutics.

Histone deacetylase-3 mediates positive feedback relationship between anaphylaxis and tumor metastasis.

Allergic inflammation has been known to enhance the metastatic potential of tumor cells. The role of histone deacetylase-3 (HDAC3) in allergic skin inflammation was reported. We investigated HDAC3 involvement in the allergic inflammation-promotion of metastatic potential of tumor cells. Passive systemic anaphylaxis (PSA) induced HDAC3 expression and FcεRI signaling in BALB/c mice. PSA enhanced the tumorigenic and metastatic potential of mouse melanoma cells in HDAC3- and monocyte chemoattractant protein 1-(MCP1)-dependent manner. The PSA-mediated enhancement of metastatic potential involved the induction of HDAC3, MCP1, and CD11b (a macrophage marker) expression in the lung tumor tissues. We examined an interaction between anaphylaxis and tumor growth and metastasis at the molecular level. Conditioned medium from antigen-stimulated bone marrow-derived mouse mast cell cultures induced the expression of HDAC3, MCP1, and CCR2, a receptor for MCP1, in B16F1 mouse melanoma cells and enhanced migration and invasion potential of B16F1 cells. The conditioned medium from B16F10 cultures induced the activation of FcεRI signaling in lung mast cells in an HDAC3-dependent manner. FcεRI signaling was observed in lung tumors derived from B16F10 cells. Target scan analysis predicted HDAC3 to be as a target of miR-384, and miR-384 and HDAC3 were found to form a feedback regulatory loop. miR-384, which is decreased by PSA, negatively regulated HDAC3 expression, allergic inflammation, and the positive feedback regulatory loop between anaphylaxis and tumor metastasis. We show the miR-384/HDAC3 feedback loop to be a novel regulator of the positive feedback relationship between anaphylaxis and tumor metastasis.

Integrin α(5) interacts with EGFR, is necessary for FcɛRI signaling and is necessary for allergic inflammation in relation with angiogenesis.

Recent reports have suggested role for epidermal growth factor receptor (EGFR) in asthma and skin inflammation. Integrin(s) are known to be necessary for the transactivation of EGFR. The roles of EGFR and integrin(s) in allergic inflammation were investigated. Antigen stimulation induced activation of EGFR and interaction between EGFR and integrin α(5) in Rat Basophilic Leukemia (RBL2H3) cells and bone marrow-derived mouse mast cells (BMMCs). Flow cytometry revealed increased phosphorylation of EGFR on cell surfaces. Antigen stimulation induced interaction between EGFR and FcɛRI in both RBL2H3 cells and BMMCs. Blocking of EGFR or integrin α exerted negative effects on rac1 activity and secretion of ß-hexosaminidase in both RBL2H3 cells and BMMCs. EGFR and integrin α(5) were found to be necessary for IgE-dependent cutaneous anaphylaxis. FAK (focal adhesion kinase), interacted with EGFR and with FcɛRI upon antigen stimulation, and it was necessary for the increased secretion of ß-hexosaminidase in both RBL2H3 cells and BMMCs. EGFR and integrin α(5) were necessary for interactions between activated RBL2H3 cells, BMMCs and rat aortic endothelial cells (RAECs). Conditioned medium of antigen-stimulated RBL2H3 cells promoted RAECs tube formation, rat aortic ring formation and blood vessel formation. Conditioned medium of antigen-stimulated BMMCs also had the same effects on RAECs. This enhanced angiogenic potential of RAECs was dependent on EGFR and integrin α(5). In conclusion, EGFR, via interaction with FcɛRI and integrin α(5), is necessary for allergic inflammation associated with cellular interaction.

Transglutaminase II interacts with rac1, regulates production of reactive oxygen species, expression of snail, secretion of Th2 cytokines and mediates in vitro and in vivo allergic inflammation.

Transglutaminase II (TGase II) is a protein cross-linking enzyme with diverse biological functions. Here we report the role of TGase II in allergic inflammation. Antigen stimulation induced expression and activity of TGase II by activation of NF-kappaB in rat basophilic leukemia (RBL2H3) cells. This induction of TGase II was dependent on FcepsilonRI and EGFR. Interaction between TGase II and rac1 was induced following antigen stimulation. TGase II was responsible for the increased production of reactive oxygen species, expression of prostaglandin E2 synthase (PGE2 synthase) and was responsible for increased secretion of prostaglandin E2. ChIP assay showed that TGase II, through interaction with NF-kappaB, was responsible for the induction of histone deacetylase-3 (HDAC3) and snail by direct binding to promoter sequences. HDAC3 and snail induced by TGase II, exerted transcriptional repression on E-cadherin. Snail exerted negative effect on expression of MMP-2, and secretion of Th2 cytokines. Inhibition of matrix metalloproteinase-2 (MMP-2) inhibited secretion of Th2 cytokines. In vivo induction of TGase II was observed in Balb/c mouse model of IgE antibody-induced passive cutaneous anaphylaxis. Chemical inhibition of TGase II exerted negative effect on IgE-dependent passive cutaneous anaphylaxis. Chemical inhibition of TGase II by cystamine exerted negative effect on Balb/c mouse model of phorbol myristate acetate (PMA)-induced atopic dermatitis. These results suggest novel role of TGase II in allergic inflammation and TGase II can be developed as target for the development of allergy therapeutics.