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British Journal of Pharmacology Oct 2022Atopic dermatitis (AD) is one of the most common chronic inflammatory cutaneous diseases with unmet clinical needs. As a common ingredient found in several medicinal...
BACKGROUND AND PURPOSE
Atopic dermatitis (AD) is one of the most common chronic inflammatory cutaneous diseases with unmet clinical needs. As a common ingredient found in several medicinal herbs with efficacy on cutaneous inflammatory diseases, Scutellarein (Scu) has been shown to possess anti-inflammatory and anti-proliferative activities. We aimed to evaluate the therapeutic efficacy of Scu against AD and its underlying molecular mechanism.
EXPERIMENTAL APPROACH
Efficacy of Scu on AD was evaluated in 2,4-dinitrofluorobenzene (DNFB) and carvacrol-induced dermatitis mouse models. Cytokine mRNA and serum IgE levels were examined using qPCR and ELISA, respectively. Voltage clamp recordings were used to measure currents mediated by transient receptor potential (TRP) channels. In silico docking, site-direct mutagenesis, and covalent modification were used to explore the binding pocket of Scu on TRPV3.
KEY RESULTS
Subcutaneous administration of Scu efficaciously suppresses DNFB and carvacrol-induced pruritus, epidermal hyperplasia and skin inflammation in wild type mice but has no additional benefit in Trpv3 knockout mice in the carvacrol model. Scu is a potent and selective TRPV3 channel allosteric negative modulator with an apparent affinity of 1.18 μM. Molecular docking coupled with site-direct mutagenesis and covalent modification of incorporated cysteine residues demonstrate that Scu targets the cavity formed between the pore helix and transmembrane helix S6. Moreover, Scu attenuates endogenous TRPV3 activity in human keratinocytes and inhibits carvacrol-induced proliferative and proinflammatory responses.
CONCLUSION AND IMPLICATIONS
Collectively, these data demonstrate that Scu ameliorates carvacrol-induced skin inflammation by directly inhibiting TRPV3, and TRPV3 represents a viable therapeutic target for AD treatment.
Topics: Animals; Anti-Inflammatory Agents; Apigenin; Cymenes; Cysteine; Cytokines; Dermatitis, Atopic; Dinitrofluorobenzene; Humans; Immunoglobulin E; Inflammation; Mice; Mice, Knockout; Molecular Docking Simulation; RNA, Messenger; TRPV Cation Channels; Transient Receptor Potential Channels
PubMed: 35771623
DOI: 10.1111/bph.15913 -
Frontiers in Immunology 2023Major histocompatibility complex (MHC) class Ib molecules present antigens to subsets of T cells primarily involved in host defense against pathogenic microbes and...
Major histocompatibility complex (MHC) class Ib molecules present antigens to subsets of T cells primarily involved in host defense against pathogenic microbes and influence the development of immune-mediated diseases. The MHC class Ib molecule MHC-related protein 1 (MR1) functions as a platform to select MR1-restricted T cells, including mucosal-associated invariant T (MAIT) cells in the thymus, and presents ligands to them in the periphery. MAIT cells constitute an innate-like T-cell subset that recognizes microbial vitamin B metabolites and plays a defensive role against microbes. In this study, we investigated the function of MR1 in allergic contact dermatitis (ACD) by examining wild-type (WT) and MR1-deficient (MR1) mice in which ACD was induced with 2,4-dinitrofluorobenzene (DNFB). MR1 mice exhibited exaggerated ACD lesions compared with WT mice. More neutrophils were recruited in the lesions in MR1 mice than in WT mice. WT mice contained fewer MAIT cells in their skin lesions following elicitation with DNFB, and MR1 mice lacking MAIT cells exhibited a significant increase in IL-17-producing αβ and γδ T cells in the skin. Collectively, MR1 mice displayed exacerbated ACD from an early phase with an enhanced type 3 immune response, although the precise mechanism of this enhancement remains elusive.
Topics: Animals; Mice; Dermatitis, Allergic Contact; Dinitrofluorobenzene; Histocompatibility Antigens Class I; Interleukin-17; Minor Histocompatibility Antigens
PubMed: 37409131
DOI: 10.3389/fimmu.2023.1215478 -
BMC Immunology Dec 2022The progression of acute-to-chronic atopic dermatitis is accompanied by multiple helper T-cell cytokine responses, but the mechanisms and relative importance of these...
BACKGROUND
The progression of acute-to-chronic atopic dermatitis is accompanied by multiple helper T-cell cytokine responses, but the mechanisms and relative importance of these changes remain unclear. There is no animal model for atopic dermatitis that recapitulates these cytokine responses.
OBJECTIVE
We sought to build a novel mouse model for atopic dermatitis (AD) that recapitulates these helper T-cell responses and some dynamic changes in cytokine responses in the progression of AD.
METHODS
Female BALB/c mice were subjected to the application of dinitrofluorobenzene (DNFB) and ovalbumin (OVA) to induce AD-like dermatitis. Skin lesions and serum were collected from mice in the acute and chronic phases to detect changes in cytokine responses and other features of AD.
RESULTS
Combined application of DNFB and OVA successfully induced AD-like dermatitis and histological changes as well as epidermal barrier dysfunction. In the acute phase of AD-like dermatitis, Th2-associated cytokines were mainly increased in serum and skin lesions. In the chronic phase of AD-like dermatitis, Th2-associated cytokines were still highly expressed, while Th1- and Th17-associated cytokines were also gradually increased. Compared with the acute phase, the JAK-STAT signaling pathway was highly expressed in the chronic phase of AD-like dermatitis.
CONCLUSION
The combined application of DNFB and OVA could be used to build a new mouse model for atopic dermatitis. This mouse model recapitulates the helper T-cell responses and some dynamic changes in cytokine responses in the progression of acute-to-chronic in human AD. The JAK-STAT signaling pathway plays a pivotal role in the chronicity of AD.
Topics: Humans; Female; Mice; Animals; Dinitrofluorobenzene; Ovalbumin; Dermatitis, Atopic; Cytokines; T-Lymphocytes, Helper-Inducer
PubMed: 36476273
DOI: 10.1186/s12865-022-00531-2 -
Oncotarget May 2023The creatine shuttle translocates the energy generated by oxidative phosphorylation to the cytoplasm via mitochondrial creatine kinase (MTCK) and creatine kinase B (CKB)...
The creatine shuttle translocates the energy generated by oxidative phosphorylation to the cytoplasm via mitochondrial creatine kinase (MTCK) and creatine kinase B (CKB) in the cytoplasm. It is not apparent how the creatine shuttle is related to cancer. Here, we analyzed the expression and function of CKB and MTCK in colorectal cancer (CRC) and investigated the role of the creatine shuttle in CRC. Compared with normal mucosa, 184 CRC tissues had higher levels of CKB and MTCK, and these levels were associated with histological grade, tumor invasion, and distant metastasis. CK inhibitor dinitrofluorobenzene (DNFB) on CRC cell lines HT29 and CT26 inhibited cell proliferation and stemness to less than 2/3 and 1/20 of their control levels, respectively. In this treatment, the production of reactive oxygen species increased, mitochondrial respiration decreased, and mitochondrial volume and membrane potential decreased. In a syngeneic BALB/c mouse model using CT26 cells pretreated with DNFB, peritoneal metastasis was suppressed to 70%. Phosphorylation of EGFR, AKT, and ERK1/2 was inhibited in DNFB-treated tumors. High ATP concentrations prevented EGFR phosphorylation in HT29 cells following DNFB treatment, CKB or MTCK knockdown, and cyclocreatine administration. Despite not being immunoprecipitated, CKB and EGFR were brought closer together by EGF stimulation. These findings imply that blocking the creatine shuttle decreases the energy supply, suppresses oxidative phosphorylation, and blocks ATP delivery to phosphorylation signals, preventing signal transduction. These findings highlight the critical role of the creatine shuttle in cancer cells and suggest a potential new cancer treatment target.
Topics: Mice; Animals; Creatine; Creatine Kinase; Dinitrofluorobenzene; Creatine Kinase, Mitochondrial Form; Oxidative Phosphorylation; Adenosine Triphosphate; Colorectal Neoplasms; ErbB Receptors
PubMed: 37204253
DOI: 10.18632/oncotarget.28436 -
Allergology International : Official... Jul 2017Alternatively activated macrophages (M2 macrophages) play key roles in the suppression of Th1 cell responses and the orchestration of tissue repair. However, recent... (Review)
Review
Alternatively activated macrophages (M2 macrophages) play key roles in the suppression of Th1 cell responses and the orchestration of tissue repair. However, recent studies have shown that M2 macrophages have potentials to produce high levels of proinflammatory cytokines such as IL-1β, IL-6, and TNF-α, suggesting that M2 macrophages may exacerbate inflammation in some settings. In this regard, we have recently shown that large numbers of M2 macrophages accumulate in the sites of hapten-induced contact hypersensitivity (CHS), an animal model of allergic contact dermatitis, and that M2 macrophages exacerbate hapten-induced CHS by producing matrix metalloproteinase 12 (MMP12). We have also shown that suppressor of cytokine signaling-3 (SOCS3), a member of SOCS family proteins that are cytokine-inducible negative regulators of the JAK/STAT signaling pathways, is highly and preferentially expressed in M2 macrophages in hapten-induced CHS and that SOCS3 expressed in M2 macrophages is involved in the attenuation of CHS by suppressing MMP12 production. These findings underscore the importance of M2 macrophage-derived MMP12 in the development of CHS, and suggest that inhibition of M2 macrophages or MMP12 could be a potential therapeutic strategy for the treatment of allergic contact dermatitis.
Topics: Animals; Chronic Disease; Cytokines; Dermatitis, Allergic Contact; Dinitrofluorobenzene; Gene Expression Regulation; Humans; Inflammation Mediators; Macrophage Activation; Macrophages; Matrix Metalloproteinase 12; Suppressor of Cytokine Signaling 3 Protein
PubMed: 28320580
DOI: 10.1016/j.alit.2017.02.015 -
Frontiers in Physiology 2022Atopic dermatitis (AD) is a chronic inflammatory skin disease with a high prevalence worldwide. Increasing evidence suggests that the gut microbiota plays an important...
Atopic dermatitis (AD) is a chronic inflammatory skin disease with a high prevalence worldwide. Increasing evidence suggests that the gut microbiota plays an important role in the pathogenesis of AD. In this study, we sought to verify the effect of polysaccharides (DCP) on AD induced by 2,4-Dinitrofluorobenzene (DNFB) in Balb/c mice regarding its impact on the intestinal microbiome. We found that 2-week oral administration of DCP improved AD-like symptoms and histological damage of skin, reduced mast cell infiltration, down-regulated the level of serum total IgE and the expression of pro-inflammatory cytokines such as TNF-α, IFN-γ, IL-4 and IL-6, and increased the expression level of anti-inflammatory cytokine IL-10. The beneficial effect of DCP was attributed to the restoration of the intestinal microbiome composition and the unbalance of the intestinal homeostasis. Our results indicated that DCP might be used as a promising novel microbiota-modulating agent for the treatment of AD.
PubMed: 36160845
DOI: 10.3389/fphys.2022.976421 -
International Journal of Molecular... Jan 2022Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with excessive inflammation and defective skin barrier function. Activated protein C (APC) is a...
Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with excessive inflammation and defective skin barrier function. Activated protein C (APC) is a natural anticoagulant with anti-inflammatory and barrier protective functions. However, the effect of APC on AD and its engagement with protease activated receptor (PAR)1 and PAR2 are unknown. Contact hypersensitivity (CHS), a model for human AD, was induced in PAR1 knockout (KO), PAR2KO and matched wild type (WT) mice using 2,4-dinitrofluorobenzene (DNFB). Recombinant human APC was administered into these mice as preventative or therapeutic treatment. The effect of APC and PAR1KO or PARKO on CHS was assessed via measurement of ear thickness, skin histologic changes, inflammatory cytokine levels, Th cell phenotypes and keratinocyte function. Compared to WT, PAR2KO but not PAR1KO mice displayed less severe CHS when assessed by ear thickness; PAR1KO CHS skin had less mast cells, lower levels of IFN-γ, IL-4, IL-17 and IL-22, and higher levels of IL-1β, IL-6 and TGF-β1, whereas PAR2KO CHS skin only contained lower levels of IL-22 and IgE. Both PAR1KO and PAR2KO spleen cells had less Th1/Th17/Th22/Treg cells. In normal skin, PAR1 was present at the stratum granulosum and spinosum, whereas PAR2 at the upper layers of the epidermis. In CHS, however, the expression of PAR1 and PAR2 were increased and spread to the whole epidermis. In vitro, compared to WT cells, PAR1KO keratinocytes grew much slower, had a lower survival rate and higher para permeability, while PAR2KO cells grew faster, were resistant to apoptosis and para permeability. APC inhibited CHS as a therapeutic but not as a preventative treatment only in WT and PAR1KO mice. APC therapy reduced skin inflammation, suppressed epidermal PAR2 expression, promoted keratinocyte growth, survival, and barrier function in both WT and PAR1KO cells, but not in PAR2KO cells. APC therapy can mitigate CHS. Although APC acts through both PAR1 and PAR2 to regulate Th and mast cells, suppression of clinical disease in mice is achieved mainly via inhibition of PAR2 alone. Thus, APC may confer broad therapeutic benefits as a disease-modifying treatment for AD.
Topics: Animals; Dermatitis, Contact; Dinitrofluorobenzene; Female; Gene Expression Regulation; Humans; Inflammation; Mice; Mice, Knockout; Protein C; Receptor, PAR-1; Receptor, PAR-2; Skin
PubMed: 35008942
DOI: 10.3390/ijms23010516 -
Nutrients Sep 2023Atopic dermatitis (AD) is a chronic inflammatory disease characterized by dry and itchy skin. Recently, it has been reported that oxidative stress is involved in skin...
Atopic dermatitis (AD) is a chronic inflammatory disease characterized by dry and itchy skin. Recently, it has been reported that oxidative stress is involved in skin diseases, possibly including AD. Vitamin C, also referred to as ascorbic acid, is a vital water-soluble compound that functions as an essential nutrient. It plays a significant role as both an antioxidant and an additive in various pharmaceutical and food products. Despite the fact that vitamin C is easily oxidized, we have developed NXP081, a single-stranded DNA aptamer that selectively binds to vitamin C, thereby inhibiting its oxidation. The objective of the current research was to examine the impact of NXP081, an animal model of AD induced by 2,4-dinitrofluorobenzene (DNFB). The experimental drug NXP081, when taken orally, showed promising results in reducing inflammation and improving the skin conditions caused by DNFB. The administration of NXP081 resulted in a significant reduction in ear swelling and a noticeable improvement in the appearance of skin lesions. In addition, the administration of NXP081 resulted in a significant decrease in the migration of mast cells in the skin lesions induced by DNFB. Moreover, NXP081 inhibited the production of interferon-gamma (IFN-γ) in CD4 T cells that were activated and derived from the lymph nodes. Our findings provide useful information about the anti-inflammatory effect of NXP081 on AD.
Topics: Mice; Animals; Dermatitis, Atopic; Dinitrofluorobenzene; Mice, Inbred BALB C; Aptamers, Nucleotide; Ascorbic Acid; CD4-Positive T-Lymphocytes; Skin Diseases; Vitamins; Skin; Cytokines
PubMed: 37836456
DOI: 10.3390/nu15194172 -
Biological & Pharmaceutical Bulletin 2018Interleukin (IL)-19 is a member of the IL-10 family of interleukins and is an immuno-modulatory cytokine produced by the main macrophages. The gastrointestinal tissues...
Interleukin (IL)-19 is a member of the IL-10 family of interleukins and is an immuno-modulatory cytokine produced by the main macrophages. The gastrointestinal tissues of IL-19 knockout mice show exacerbated experimental colitis mediated by the innate immune system and T cells. There is an increasing focus on the interaction and relationship of IL-19 with the function of T cells. Contact hypersensitivity (CHS) is T cell-mediated cutaneous inflammation. Therefore, we asked whether IL-19 causes CHS. We investigated the immunological role of IL-19 in CHS induced by 1-fluoro-2,4-dinitrofluorobenzene as a hapten. IL-19 was highly expressed in skin exposed to the hapten, and ear swelling was increased in IL-19 knockout mice. The exacerbation of the CHS response in IL-19 knockout mice correlated with increased levels of IL-17 and IL-6, but no alterations were noted in the production of interferon (IFN)γ and IL-4 in the T cells of the lymph nodes. In addition to the effect on T cell response, IL-19 knockout mice increased production of inflammatory cytokines. These results show that IL-19 suppressed hapten-dependent skin inflammation in the elicitation phase of CHS.
Topics: Animals; Cells, Cultured; Dermatitis, Contact; Dinitrofluorobenzene; Ear; Gene Expression Regulation; Haptens; Immunity, Innate; Immunohistochemistry; Interleukin-10; Interleukin-17; Interleukin-6; Interleukins; Lymph Nodes; Mice, Inbred BALB C; Mice, Knockout; RNA, Messenger; Skin; Spleen; T-Lymphocytes; Th1 Cells
PubMed: 29386478
DOI: 10.1248/bpb.b17-00594 -
The Journal of Biological Chemistry Feb 20222, 4-dinitrofluorobenzene (DNFB) and 2, 4-dinitrochlorobenzene (DNCB) are well known as skin sensitizers that can cause dermatitis. DNFB has shown to more potently...
2, 4-dinitrofluorobenzene (DNFB) and 2, 4-dinitrochlorobenzene (DNCB) are well known as skin sensitizers that can cause dermatitis. DNFB has shown to more potently sensitize skin; however, how DNFB and DNCB cause skin inflammation at a molecular level and why this difference in their sensitization ability is observed remain unknown. In this study, we aimed to identify the molecular targets and mechanisms on which DNFB and DNCB act. We used a fluorescent calcium imaging plate reader in an initial screening assay before patch-clamp recordings for validation. Molecular docking in combination with site-directed mutagenesis was then carried out to investigate DNFB and DNCB binding sites in the TRPA1 ion channel that may be selectively activated by these tow sensitizers. We found that DNFB and DNCB selectively activated TRPA1 channel with EC values of 2.3 ± 0.7 μM and 42.4 ± 20.9 μM, respectively. Single-channel recordings revealed that DNFB and DNCB increase the probability of channel opening and act on three residues (C621, E625, and Y658) critical for TRPA1 activation. Our findings may not only help explain the molecular mechanism underlying the dermatitis and pruritus caused by chemicals such as DNFB and DNCB, but also provide a molecular tool 7.5-fold more potent than the current TRPA1 activator allyl isothiocyanate (AITC) used for investigating TRPA1 channel pharmacology and pathology.
Topics: Dermatitis; Dinitrochlorobenzene; Dinitrofluorobenzene; Humans; Molecular Docking Simulation; Skin; TRPA1 Cation Channel
PubMed: 34973335
DOI: 10.1016/j.jbc.2021.101555