ABSTRACT
Several studies have reported the effects of vitamin C (L-ascorbic acid, AA) on ultraviolet B (UVB)-induced cell damage using cultured keratinocytes. However, the epidermis consists of multiple cell layers, and the effect of AA on UVB-induced damage to the human epidermis remains unclear. Therefore, we investigated the effect of AA on UVB-induced skin damage using reconstituted human epidermis. The reconstituted human epidermal surface was treated with 100 and 500 mM AA and cultured for 3 h before (pre-AA treatment) or after (post-AA treatment) 120 mJ/cm2 UVB irradiation. Pre- and post-AA treatments of the epidermal surface suppressed UVB-induced cell death, apoptosis, DNA damage, reactive oxygen species (ROS) production, and the inflammatory response by downregulating tumour necrosis factor-α (TNF-α) expression and release. Moreover, the pre-AA treatment was more effective at preventing UVB-induced skin damage than the post-AA treatment. In summary, pre- and post-AA treatments of the epidermis prevent UVB-induced damage.
Subject(s)
Ascorbic Acid/pharmacology , Keratinocytes/drug effects , Radiation Injuries/drug therapy , Skin/drug effects , Apoptosis/drug effects , Apoptosis/radiation effects , Ascorbic Acid/metabolism , Cell Culture Techniques , DNA Damage/drug effects , DNA Damage/radiation effects , Epidermis/drug effects , Epidermis/metabolism , Epidermis/pathology , Epidermis/radiation effects , Gene Expression Regulation/drug effects , Humans , Keratinocytes/metabolism , Keratinocytes/pathology , Keratinocytes/radiation effects , Radiation Injuries/metabolism , Reactive Oxygen Species/metabolism , Skin/injuries , Skin/radiation effects , Tumor Necrosis Factor-alpha/genetics , Ultraviolet Rays/adverse effectsABSTRACT
Peptidylarginine deiminases (PADs) are posttranslational modification enzymes that citrullinate (deiminate) protein arginine residues in a calcium-dependent manner, yielding citrulline residues. Enzymatic citrullination abolishes positive charges of native protein molecules, inevitably causing significant alterations in their structure and function. Previously, we reported the abnormal accumulation of citrullinated proteins and an increase of PAD2 content in hippocampi of patients with Alzheimer disease. In this study, we investigated PAD expression by using dibutyryl cAMP (dbcAMP) in human astrocytoma U-251MG cells. Under normal culture conditions, PAD2 and PAD3 mRNA expression is detectable with quantitative PCR in U-251MG cells. The addition of dbcAMP in a dose-dependent manner significantly increased this mRNA expression and protein levels. Moreover, PAD enzyme activity also increased significantly and dose-dependently. Furthermore, the expression of PAD2 and PAD3 mRNA was inhibited by the cAMP-dependent PKA inhibitor KT5720, suggesting that such expression of dbcAMP-induced PAD2 and PAD3 mRNA is mediated by the cAMP-PKA signaling pathway in U-251MG cells. This is the first report to document the PAD2 and PAD3 mRNA expression induced by dbcAMP and to attribute the induction of these genes to mediation by the cAMP-PKA signaling pathway in U-251MG cells. © 2016 Wiley Periodicals, Inc.
Subject(s)
Astrocytoma/enzymology , Cyclic AMP-Dependent Protein Kinases/biosynthesis , Cyclic CMP/analogs & derivatives , Protein-Arginine Deiminases/biosynthesis , Signal Transduction/physiology , Cell Line, Tumor , Cyclic CMP/pharmacology , Dose-Response Relationship, Drug , Enzyme Induction/physiology , Humans , Protein Kinase Inhibitors/pharmacology , Protein-Arginine Deiminase Type 2 , Protein-Arginine Deiminase Type 3 , Protein-Arginine Deiminases/antagonists & inhibitors , Signal Transduction/drug effectsABSTRACT
Dendritic cells (DCs) play critical roles in determining the fate of CD4⺠T cells. Among DC sub-populations, monocyte-derived inflammatory DCs (iDCs) have been shown to play an important role in the induction of adaptive immune responses under inflammatory conditions. Although previous studies have shown that DCs have an indispensable role in the induction of allergic airway inflammation and airway hyperreactivity (AHR) in murine asthma models, the precise roles of iDCs in the asthmatic responses remain largely unknown. We show here that T(h)2 cell-mediated inflammation in murine asthma models induces the expression of some markers of alternatively activated macrophage such as arginase 1 and resistin-like molecule-α in iDCs by a mechanism depending on the intrinsic expression of STAT6. In contrast, T(h)1 cell-mediated inflammation induces iDCs to express TNF-α and inducible nitric oxide synthase (iNOS), markers of TNF-α- and iNOS-producing DCs. Moreover, we show that iDCs under a T(h)2 environment play an important role in the induction of AHR, independently of allergic airway inflammation. Our results thus indicate the importance of iDCs in the induction of AHR as downstream effector cells in T(h)2 cell-mediated asthmatic responses.
Subject(s)
Asthma/immunology , Bronchial Hyperreactivity/immunology , Dendritic Cells/immunology , Macrophages/immunology , Th2 Cells/immunology , Animals , Arginase/metabolism , Cells, Cultured , Cellular Microenvironment , Complement Pathway, Alternative , Disease Models, Animal , Humans , Intercellular Signaling Peptides and Proteins/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Pneumonia/immunology , STAT6 Transcription Factor/genetics , STAT6 Transcription Factor/metabolismABSTRACT
BACKGROUND: Recent studies have shown that prolonged Th2-type immune inflammation in the lung induces pulmonary arterial remodeling, in part through the induction of resistin-like molecule α (RELMα) expression. However, the role of interleukin-25 (IL-25; which promotes this inflammation) in the development of the pulmonary arterial remodeling remains unknown. METHODS: Ovalbumin (OVA)-sensitized C57BL/6 mice were challenged with OVA inhalation 3 times a week for 3 weeks. The effects of neutralizing anti-IL-25 antibody on OVA-induced pulmonary arterial remodeling and RELMα expression in the lung were examined. The pulmonary arterial remodeling and RELMα expression in the lung were examined in lung-specific IL-25 transgenic mice (CC10 IL-25 mice) and CC10 IL-25 mice in a natural killer T (NKT) cell-deficient background (CC10 IL-25 NKT(-/-) mice). RESULTS: Repeated OVA inhalation induced pulmonary arterial wall thickening and the expression of IL-25 and RELMα mRNA in the lung in OVA-sensitized mice. Injection of neutralizing anti-IL-25 antibody inhibited OVA-induced pulmonary arterial wall thickening and RELMα expression in the lung. CC10 IL-25 mice, but not CC10 IL-25 NKT(-/-) mice, spontaneously developed pulmonary arterial wall thickening and RELMα expression in the lung at 6 months of age. CONCLUSIONS: Prolonged expression of IL-25 in the lung induces pulmonary arterial wall thickening by NKT cell-dependent mechanisms.
Subject(s)
Interleukin-17/immunology , Natural Killer T-Cells/immunology , Pulmonary Artery/immunology , Pulmonary Artery/pathology , Animals , Antigens/immunology , Female , Interleukin-17/genetics , Mice , Mice, Transgenic , Natural Killer T-Cells/metabolism , Ovalbumin/immunology , Pulmonary Artery/metabolism , Uteroglobin/genetics , Uteroglobin/immunologyABSTRACT
Although innate immune responses are necessary for the initiation of acquired immune responses and the subsequent successful elimination of pathogens, excessive responses occasionally result in lethal endotoxic shock accompanied by a cytokine storm. B and T lymphocyte attenuator (BTLA), a coinhibitory receptor with similarities to cytotoxic T-lymphocyte antigen (CTLA)-4 and programmed death (PD)-1, is expressed in not only B and T cells but also dendritic cells (DCs) and macrophages (MÏs). Recently, several studies have reported that BTLA-deficient (BTLA(-/-)) mice show enhanced pathogen clearance compared with WT mice in early phase of infections. However, the roles of BTLA expressed on innate cells in overwhelming and uncontrolled immune responses remain unclear. Here, we found that BTLA(-/-) mice were highly susceptible to LPS-induced endotoxic shock. LPS-induced TNF-α and IL-12 production in DCs and MÏs was significantly enhanced in BTLA(-/-) mice. BTLA(-/-) DCs also produced high levels of TNF-α on stimulation with Pam3CSK4 but not poly(I:C) or CpG, suggesting that BTLA functions as an inhibitory molecule on Toll-like receptor signaling at cell surface but not endosome. Moreover, BTLA(-/-) DCs showed enhanced MyD88- and toll/IL-1R domain-containing adaptor inducing IFN (TRIF)-dependent signaling on LPS stimulation, which is associated with impaired accumulation of Src homology 2-containing protein tyrosine phosphatase in lipid rafts. Finally, we found that an agonistic anti-BTLA antibody rescued mice from LPS-induced endotoxic shock, even if the antibody was given to mice that had developed a sign of endotoxic shock. These results suggest that BTLA directly inhibits LPS responses in DCs and MÏs and that agonistic agents for BTLA might have therapeutic potential for LPS-induced endotoxic shock.
Subject(s)
Dendritic Cells/immunology , Immunity, Innate/drug effects , Lipopolysaccharides/toxicity , Macrophages/immunology , Receptors, Immunologic/immunology , Shock, Septic/immunology , Signal Transduction/drug effects , Toll-Like Receptor 4/immunology , Adaptor Proteins, Vesicular Transport/genetics , Adaptor Proteins, Vesicular Transport/immunology , Animals , Dendritic Cells/pathology , Endosomes/genetics , Endosomes/immunology , Endosomes/pathology , Immunity, Innate/genetics , Immunity, Innate/immunology , Interferon Inducers/pharmacology , Interleukin-12/genetics , Interleukin-12/immunology , Lipopeptides/pharmacology , Macrophages/pathology , Membrane Microdomains/genetics , Membrane Microdomains/immunology , Mice , Mice, Knockout , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/immunology , Poly I-C/pharmacology , Receptors, Immunologic/genetics , Shock, Septic/chemically induced , Shock, Septic/genetics , Shock, Septic/pathology , Signal Transduction/genetics , Signal Transduction/immunology , Toll-Like Receptor 4/genetics , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunologyABSTRACT
A number of studies have suggested a correlation between a decreased incidence in infectious diseases and an increased incidence of allergic diseases, including asthma. Although several pathogen-derived products have been shown to possess therapeutic potential for allergic diseases, it remains largely unknown whether ß-glucan, a cell wall component of a variety of fungi, yeasts, and bacteria, has a regulatory potential for allergic diseases. In this study, we examined the effect of curdlan, a linear ß-(1-3)-glucan, on the development of allergic airway inflammation. We found that i.p. injection of curdlan significantly inhibited Ag-induced eosinophil recruitment and Th2 cytokine production in the airways. The activation of CD4(+) T cells in the presence of curdlan induced IL-10-producing CD4(+) T cells with high levels of c-Maf expression. Curdlan-induced development of IL-10-producing CD4(+) T cells required the presence of APCs and ICOS/ICOS ligand interaction. Curdlan-induced development of IL-10-producing CD4(+) T cells also required intrinsic expression of STAT6. Furthermore, the transfer of Ag-specific CD4(+) T cells that were stimulated in the presence of curdlan inhibited Ag-induced eosinophil recruitment into the airways. Taken together, these results suggest that curdlan is capable of inducing IL-10-producing CD4(+) T cells and inhibiting the development of eosinohilic airway inflammation, underscoring the therapeutic potential of curdlan for allergic diseases.
Subject(s)
Bronchial Hyperreactivity/prevention & control , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Inflammation Mediators/administration & dosage , Interleukin-10/biosynthesis , Respiratory Hypersensitivity/prevention & control , beta-Glucans/administration & dosage , Animals , Bronchial Hyperreactivity/chemically induced , Bronchial Hyperreactivity/pathology , Cells, Cultured , Eosinophilia/immunology , Eosinophilia/pathology , Eosinophilia/prevention & control , Inflammation Mediators/therapeutic use , Injections, Intraperitoneal , Interleukin-10/physiology , Mice , Mice, Inbred BALB C , Mice, Transgenic , Respiratory Hypersensitivity/immunology , Respiratory Hypersensitivity/pathology , beta-Glucans/therapeutic useABSTRACT
BACKGROUND: Lacrimal gland enlargement (LGE) is one of the characteristics of Mikulicz's disease (MD). Recently, marked serum immunoglobulin (Ig)G4 elevation and infiltration of IgG4-positive plasma cells in the enlarged exocrine glands have been reported in MD patients. Moreover, we have reported that in patients with LGE and elevated serum IgG4 levels (IgG4-related LGE), T helper type 2 (Th2) cell-mediated immune responses are enhanced. Although prostaglandin D2 (PGD2) and its receptor CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells) have been shown to be involved in Th2 cell-related diseases such as bronchial asthma, their roles in IgG4-related diseases remain unknown. AIM: The aim of this study is to address the role of CD4+ T cells expressing CRTH2 (CRTH2+ CD4+ T cells) in IgG4-related LGE. METHODS: We examined the expression of CCR4, CXCR3 and CRTH2 on peripheral blood CD4+ T cells in patients with IgG4-related LGE, in patients with bronchial asthma and in healthy controls. RESULTS: The ratio of CCR4+ to CXCR3+ in CD45RO+ CD4+ T cells was increased in patients with IgG4-related LGE when compared to that in healthy controls, confirming that Th2 cells are predominant in patients with IgG4-related LGE. In addition, the frequency of CRTH2+ cells in CD4+ T cells was significantly increased in these patients, compared to healthy controls. Furthermore, although not statistically significant, the frequency of CRTH2+ cells in CD4+ T cells tended to correlate with the levels of serum IgE and the number of blood eosinophils in patients with IgG4-related LGE. CONCLUSION: CRTH2+ CD4+ T cells may be involved in the pathogenesis of IgG4-related LGE.
Subject(s)
CD4-Positive T-Lymphocytes/immunology , Immunoglobulin G/immunology , Lacrimal Apparatus Diseases/immunology , Receptors, Immunologic/immunology , Receptors, Prostaglandin/immunology , Adult , Aged , Asthma/immunology , Female , Humans , Male , Middle Aged , Receptors, CCR4/immunology , Receptors, CXCR3/immunologyABSTRACT
BACKGROUND: IL-22 functions as both a proinflammatory cytokine and an anti-inflammatory cytokine in various inflammations, depending on the cellular and cytokine milieu. However, the roles of IL-22 in the regulation of allergic airway inflammation are still largely unknown. OBJECTIVE: We sought to determine whether IL-22 is involved in the regulation of allergic airway inflammation. METHODS: We examined IL-22 production and its cellular source at the site of antigen-induced airway inflammation in mice. We also examined the effect of IL-22 neutralization, as well as IL-22 administration, on antigen-induced airway inflammation. We finally examined the effect of IL-22 on IL-25 production from a lung epithelial cell line (MLE-15 cells). RESULTS: Antigen inhalation induced IL-22 production in the airways of sensitized mice. CD4(+) T cells, but not other lymphocytes or innate cells, infiltrating in the airways produced IL-22, and one third of IL-22-producing CD4(+) T cells also produced IL-17A. The neutralization of IL-22 by anti-IL-22 antibody enhanced antigen-induced IL-13 production, eosinophil recruitment, and goblet cell hyperplasia in the airways. On the other hand, intranasal administration of recombinant IL-22 attenuated antigen-induced eosinophil recruitment into the airways. Moreover, anti-IL-22 antibody enhanced antigen-induced IL-25 production in the airways, and anti-IL-25 antibody reversed the enhancing effect of anti-IL-22 antibody on antigen-induced eosinophil recruitment into the airways. Finally, IL-22 inhibited IL-13-mediated enhancement of IL-25 expression in IL-1ß- or LPS-stimulated MLE-15 cells. CONCLUSION: IL-22 attenuates antigen-induced airway inflammation, possibly by inhibiting IL-25 production by lung epithelial cells.
Subject(s)
Asthma/immunology , Eosinophilia/immunology , Epithelial Cells/immunology , Interleukins/immunology , Pneumonia/immunology , Respiratory Mucosa/immunology , Animals , Asthma/metabolism , Blotting, Western , Bronchoalveolar Lavage Fluid/immunology , Disease Models, Animal , Eosinophilia/metabolism , Epithelial Cells/metabolism , Immunohistochemistry , Interleukins/biosynthesis , Interleukins/metabolism , Mice , Mice, Inbred BALB C , Pneumonia/metabolism , Real-Time Polymerase Chain Reaction , Respiratory Mucosa/metabolism , Interleukin-22ABSTRACT
Although B and T lymphocyte attenuator (BTLA) was originally identified as an inhibitory coreceptor selectively expressed on Th1 cells and B cells, recent studies have revealed that BTLA is expressed on a variety of cells, including macrophages, dendritic cells, and NK cells, and modulates their functions. However, the role of BTLA in the regulation of NKT cell function remains unknown. In this study, we found that BTLA was expressed on NKT cells at the levels similar to those on T cells and that BTLA-deficient (BTLA(-/-)) NKT cells produced larger amounts of IL-4 and IFN-gamma upon alpha-glactosylceramide stimulation as compared with wild-type (WT) NKT cells. In vivo, BTLA(-/-) mice produced larger amounts of IL-4 and IFN-gamma upon Con A injection and were more susceptible to Con A-induced hepatitis than WT mice. In addition, the augmentation of Con A-induced hepatitis in BTLA(-/-) mice was not observed in BTLA/NKT-double deficient mice. Moreover, NKT(-/-) mice reconstituted with BTLA(-/-) NKT cells were significantly more susceptible to Con A-induced hepatitis as compared with NKT (-/-) mice reconstituted with WT NKT cells. These results suggest that BTLA functions as the inhibitory coreceptor of NKT cells and plays a critical role in the prevention of NKT cell-mediated liver injury.