RESUMO
Psoriasis is a chronic inflammatory disease whose etiology is multifactorial. The contributions of cellular metabolism to psoriasis are unclear. Here, we report that interleukin-17 (IL-17) downregulated Protein Phosphatase 6 (PP6) in psoriatic keratinocytes, causing phosphorylation and activation of the transcription factor C/EBP-ß and subsequent generation of arginase-1. Mice lacking Pp6 in keratinocytes were predisposed to psoriasis-like skin inflammation. Accumulation of arginase-1 in Pp6-deficient keratinocytes drove polyamine production from the urea cycle. Polyamines protected self-RNA released by psoriatic keratinocytes from degradation and facilitated the endocytosis of self-RNA by myeloid dendritic cells to promote toll-like receptor-7 (TLR7)-dependent RNA sensing and IL-6 production. An arginase inhibitor improved skin inflammation in murine and non-human primate models of psoriasis. Our findings suggest that urea cycle hyperreactivity and excessive polyamine generation in psoriatic keratinocytes promote self-RNA sensation and PP6 deregulation in keratinocytes is a pivotal event that amplifies the inflammatory circuits in psoriasis.
Assuntos
Células Dendríticas/imunologia , Queratinócitos/metabolismo , Fosfoproteínas Fosfatases/deficiência , Poliaminas/metabolismo , Psoríase/patologia , RNA/imunologia , Células 3T3 , Animais , Arginase/antagonistas & inibidores , Arginase/metabolismo , Arginina/metabolismo , Autoantígenos/imunologia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Células HEK293 , Células HaCaT , Humanos , Interleucina-17/metabolismo , Macaca fascicularis , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fosfoproteínas Fosfatases/genética , Fosforilação , Pele/patologia , Receptor 7 Toll-Like/imunologiaRESUMO
Micropeptides encoded by short open reading frames (sORFs) within long noncoding RNAs (lncRNAs) are beginning to be discovered and characterized as regulators of biological and pathological processes. Here, we find that lncRNA Dleu2 encodes a 17-amino-acid micropeptide, which we name Dleu2-17aa, that is abundantly expressed in T cells. Dleu2-17aa promotes inducible regulatory T (iTreg) cell generation by interacting with SMAD Family Member 3 (Smad3) and enhancing its binding to the Foxp3 conserved non-coding DNA sequence 1 (CNS1) region. Importantly, the genetic deletion of Dleu2-17aa in mice by start codon mutation impairs iTreg generation and worsens experimental autoimmune encephalomyelitis (EAE). Conversely, the exogenous supplementation of Dleu2-17aa relieves EAE. Our findings demonstrate an indispensable role of Dleu2-17aa in maintaining immune homeostasis and suggest therapeutic applications for this peptide in treating autoimmune diseases.
Assuntos
Encefalomielite Autoimune Experimental , RNA Longo não Codificante , Animais , Camundongos , Autoimunidade , Peptídeos/metabolismo , RNA Longo não Codificante/genética , Linfócitos T Reguladores/metabolismoRESUMO
Psoriasis is a common inflammatory skin disorder with no cure. Mesenchymal stem cells (MSCs) have immunomodulatory properties for psoriasis, but the therapeutic efficacies varied, and the molecular mechanisms were unknown. In this study, we improved the efficacy by enhancing the immunomodulatory effects of umbilical cord-derived MSCs (UC-MSCs). UC-MSCs stimulated by TNF-α and IFN-γ exhibited a better therapeutic effect in a mouse model of psoriasis. Single-cell RNA sequencing revealed that the stimulated UC-MSCs overrepresented a subpopulation expressing high tryptophanyl-tRNA synthetase 1 (WARS1). WARS1-overexpressed UC-MSCs treat psoriasis-like skin inflammation more efficiently than control UC-MSCs by restraining the proinflammatory macrophages. Mechanistically, WARS1 maintained a RhoA-Akt axis and governed the immunomodulatory properties of UC-MSCs. Together, we identify WARS1 as a master regulator of UC-MSCs with enhanced immunomodulatory capacities, which paves the way for the directed modification of UC-MSCs for escalated therapeutic efficacy.
Assuntos
Imunomodulação , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/imunologia , Animais , Camundongos , Humanos , Transplante de Células-Tronco Mesenquimais/métodos , Triptofano-tRNA Ligase/genética , Psoríase/imunologia , Psoríase/terapia , Modelos Animais de Doenças , Análise de Célula Única , Análise de Sequência de RNA , Cordão Umbilical/citologia , Cordão Umbilical/imunologia , Camundongos Endogâmicos C57BL , Células CultivadasRESUMO
Atopic dermatitis (AD) is a common inflammatory skin disorder. Mast cells play an important role in AD because they regulate allergic reactions and inflammatory responses. However, whether and how the modulation of mast cell activity affects AD has not been determined. In this study, we aimed to determine the effects and mechanisms of 3-O-cyclohexanecarbonyl-11-keto-ß-boswellic acid (CKBA). This natural compound derivative alleviates skin inflammation by inhibiting mast cell activation and maintaining skin barrier homeostasis in AD. CKBA markedly reduced serum IgE levels and alleviated skin inflammation in calcipotriol (MC903)-induced AD mouse model. CKBA also restrained mast cell degranulation both in vitro and in vivo. RNA-seq analysis revealed that CKBA downregulated the extracellular signal-regulated kinase (ERK) signaling in BM-derived mast cells activated by anti-2,4-dinitrophenol/2,4-dinitrophenol-human serum albumin. We proved that CKBA suppressed mast cell activation via ERK signaling using the ERK activator (t-butyl hydroquinone) and inhibitor (selumetinib; AZD6244) in AD. Thus, CKBA suppressed mast cell activation in AD via the ERK signaling pathway and could be a therapeutic candidate drug for AD.
Assuntos
Dermatite Atópica , Camundongos , Humanos , Animais , Dermatite Atópica/tratamento farmacológico , Mastócitos/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Imunoglobulina E/metabolismo , Transdução de Sinais , Inflamação/metabolismo , Dinitrofenóis/metabolismo , Dinitrofenóis/farmacologia , Dinitrofenóis/uso terapêutico , Citocinas/metabolismoRESUMO
Recent evidence has revealed that small polypeptides (containing fewer than 100 amino acids) can be translated from noncoding RNAs (ncRNAs), which are usually defined as RNA molecules that do not encode proteins. However, studies on functional products translated from primary transcripts of microRNA (pri-miRNA) are quite limited. Here, we describe a peptide termed miPEP31 that is encoded by pri-miRNA-31. miPEP31 is highly expressed in Foxp3+ regulatory T cells (Tregs ) and significantly promotes the differentiation of Tregs without affecting their inhibitory ability. Our results show that miPEP31 is a cell-penetrating peptide both in vitro and in vivo. miPEP31 downregulates miR-31 expression, enhances peripheral Treg induction, and dramatically suppresses experimental autoimmune encephalomyelitis. Mechanistically, we show that miPEP31 acts as a transcriptional repressor inhibiting the expression of miRNA-31, a negative regulator of Tregs . Our results reveal an indispensable role of miPEP31 in maintaining immune homeostasis by promoting Treg differentiation and also present a potential therapeutic peptide for modulating miRNA expression and treating autoimmune diseases.
Assuntos
Encefalomielite Autoimune Experimental , MicroRNAs , Animais , Autoimunidade/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Peptídeos/genética , Peptídeos/metabolismo , Peptídeos/farmacologia , Linfócitos T Reguladores/metabolismoRESUMO
IL-17-secreting Th17 cells play an important role in the pathogenesis of various inflammatory and autoimmune diseases. IL-17-targeted biologics and small molecules are becoming promising treatments for these diseases. In this study, we report that SZB120, a derivative of the natural compound 3-acetyl-ß-boswellic acid, inhibits murine Th17 cell differentiation by interacting with the α-subunit of eukaryotic initiation factor 2 (eIF2α). We showed that SZB120 directly interacts with eIF2α and contributes to serine 51 phosphorylation of eIF2α. The suppressive effect of SZB120 on Th17 cell differentiation was reversed by GSK2606414, an inhibitor of eIF2α phosphokinase. Phosphorylation of eIF2α induced by SZB120 decreased the protein expression of IκBζ, which is important for Th17 cell differentiation. Notably, interaction with eIF2α by SZB120 also impaired glucose uptake and glycolysis in T cells. In vivo, SZB120 treatment of C57BL/6 mice significantly attenuated IL-17/Th17-mediated autoimmune disease. Our study indicates that SZB120 is a promising drug candidate for IL-17/Th17-mediated inflammatory diseases.
Assuntos
Produtos Biológicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Fator de Iniciação 2 em Eucariotos/metabolismo , Fatores Imunológicos/farmacologia , Células Th17/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Células Cultivadas , Feminino , Interleucina-17/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação/efeitos dos fármacos , Células Th17/metabolismoRESUMO
MicroRNA-31 (miR-31) is an evolutionarily conserved microRNA, and its biological function in colorectal cancer and other cancers is controversial. In this study, we identified the host gene of mouse miR-31 and found that miR-31 was over-expressed in both human colorectal cancer and mouse colon cancer models. We here developed a miR-31 conditional knockout mouse model that allows for colon epithelium specific deletion of miR-31 to investigate its functionality in colon cancer development. We demonstrated that mice with miR-31 conditional deletion resulted in more severe colitis-associated cancer than wild-type, and we further identified Wdr5 as an important target of miR-31.
Assuntos
Colite/complicações , Colite/genética , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/genética , MicroRNAs/genética , Animais , Colite/patologia , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Regulação para Cima/genéticaRESUMO
Psoriasis is a chronic recurrent inflammatory skin disorder characterized by the dysregulated cross-talk between epidermal keratinocytes and immune cells, leading to keratinocyte hyperproliferation. Several studies demonstrated that Wnt pathway genes were differentially expressed in psoriatic plaques and likely were involved in the pathophysiology of disease. However, the molecular mechanisms underlying Wnt signaling regulation in epidermal hyperplasia in psoriasis remain largely unknown. We report that the expression of secreted frizzled-related protein (SFRP) 4, a negative regulator of the Wnt signaling pathway, was diminished in lesional skin of mouse models and patients with psoriasis. SFRP4 directly inhibited excessive keratinocyte proliferation evoked by proinflammatory cytokines in vitro. Pharmacological inhibition of Wnt signaling or intradermal injection of SFRP4 decreased the severity of the psoriasiform skin phenotype in vivo, including decreased acanthosis and reduced leukocyte infiltration. Mechanistically, we identified that aberrant promoter methylation resulted in epigenetic downregulation of SFRP4 in inflamed skin of patients with psoriasis and in the IL-23-induced mouse model. Our findings suggest that this epigenetic event is critically involved in the pathogenesis of psoriasis, and the downregulation of SFRP4 by CpG island methylation is one possible mechanism contributing to the hyperplasia of epidermis in the disease.
Assuntos
Regulação para Baixo/genética , Epiderme/patologia , Epigênese Genética/genética , Hiperplasia/genética , Proteínas Proto-Oncogênicas/genética , Psoríase/genética , Adulto , Animais , Metilação de DNA , Feminino , Humanos , Hiperplasia/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas/genética , Psoríase/patologia , Via de Sinalização WntRESUMO
Mesenchymal stem cells (MSCs) have demonstrated promising therapeutic potential for a variety of diseases including autoimmune disorders. A fundamental requirement for MSC-mediated in vivo immunosuppression is their effective trafficking. However the mechanism underlying MSC trafficking remains elusive. Here we report that skin-derived MSCs (S-MSCs) secrete high levels of interleukin-6 (IL-6) in inflammatory conditions. Disruption of the il6 or its signaling transducer gp130 blocks voltage-gated calcium (Ca(2+) ) channels (VGCC) critically required for cell contraction involved in the sequential adhesion and de-adhesion events during S-MSC migration. Deletion of il6 gene leads to a severe defect in S-MSC's trafficking and immunosuppressive function in vivo. Thus, this unexpected requirement of autocrine IL-6 for activating Ca(2+) channels uncovers a previously unrecognized link between the IL-6 signaling and the VGCC and provides novel mechanistic insights for the trafficking and immunomodulatory activities of S-MSCs.
Assuntos
Comunicação Autócrina , Canais de Cálcio/metabolismo , Movimento Celular , Interleucina-6/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Pele/citologia , Animais , Separação Celular , Derme/citologia , Humanos , Imunofenotipagem , Terapia de Imunossupressão , Inflamação/patologia , Camundongos Endogâmicos C57BL , Transdução de SinaisRESUMO
BACKGROUND AND PURPOSE: Psoriasis vulgaris is a refractory skin inflammatory disorder with 80% of the cases belonging to the mild-to-moderate type, which can be controlled by topical treatment. Nevertheless, the drugs for external use have not been upgraded for decades. We modified acetyl-11-keto-beta-boswellic acid (ABKA), a natural compound shown to treat psoriasis animal models, to improve efficacy and solubility for topical use. EXPERIMENTAL APPROACH: Eleven compounds were synthesized using AKBA as a lead compound, and their effects on Th17 cell differentiation were screened. 3-O-cyclohexanecarbonyl-11-keto-ß-boswellic acid (CKBA) potently inhibited Th17 cell differentiation. Its efficacy in a mouse model of psoriasis was assessed along with its pharmacology and safety profile when topically or systemically delivered to several animal species. KEY RESULTS: CKBA inhibited mouse and human Th17 cell differentiation with an IC50 of 3.28 and 3.61 µM, respectively, and directly targeted acetyl-CoA carboxylase 1 (ACC1). Safety evaluation and toxicity tests suggested that systemically delivered high-dose CKBA for 14 days had no dose-associated adverse effects on the CNS, haematopoietic, cardiovascular, respiratory and digestive systems of cynomolgus monkeys. CKBA ointment permeated the skin and did not irritate or sensitize intact skin. CKBA ointment mediated dose-dependent suppression of imiquimod-induced psoriasis-like skin inflammation with slow absorption and limited bioavailability (<10% in rats and <1% in minipigs). CONCLUSIONS AND IMPLICATIONS: CKBA is safe when topically or systemically delivered to animals. The beneficial effects of CKBA ointment in a mouse model of psoriasis indicate that this is a promising drug candidate for further development as a treatment for psoriasis.
Assuntos
Dermatite , Psoríase , Triterpenos , Ratos , Camundongos , Animais , Humanos , Suínos , Pomadas/efeitos adversos , Porco Miniatura , Psoríase/tratamento farmacológico , Psoríase/induzido quimicamente , Pele , Triterpenos/farmacologia , Triterpenos/uso terapêuticoRESUMO
Dermal fibroblasts and cutaneous nerves are important players in skin diseases, while their reciprocal roles during skin inflammation have not been characterized. Here we identify an inflammation-induced subset of papillary fibroblasts that promotes aberrant neurite outgrowth and psoriasiform skin inflammation by secreting the extracellular matrix protein tenascin-C (TNC). Single-cell analysis of fibroblast lineages reveals a Tnc+ papillary fibroblast subset with pro-axonogenesis and neuro-regulation transcriptomic hallmarks. TNC overexpression in fibroblasts boosts neurite outgrowth in co-cultured neurons, while fibroblast-specific TNC ablation suppresses hyperinnervation and alleviates skin inflammation in male mice modeling psoriasis. Dermal γδT cells, the main producers of type 17 pathogenic cytokines, frequently contact nerve fibers in mouse psoriasiform lesions and are likely modulated by postsynaptic signals. Overall, our results highlight the role of an inflammation-responsive fibroblast subset in facilitating neuro-immune synapse formation and suggest potential avenues for future therapeutic research.
Assuntos
Psoríase , Tenascina , Masculino , Camundongos , Animais , Tenascina/genética , Tenascina/metabolismo , Neuroimunomodulação , Proteínas da Matriz Extracelular/metabolismo , Modelos Animais de Doenças , Psoríase/metabolismo , Fibroblastos/metabolismo , Inflamação/patologiaRESUMO
Regulatory T (Treg) cells constitute a dynamic population that is critical in autoimmunity. Treg cell therapies for autoimmune diseases are mainly focused on enhancing their suppressive activities. However, recent studies demonstrated that certain inflammatory conditions induce Treg cell instability with diminished FoxP3 expression and convert them into pathogenic effector cells. Therefore, the identification of novel targets crucial to both Treg cell function and plasticity is of vital importance to the development of therapeutic approaches in autoimmunity. In this study, we found that conditional Pp6 knockout (cKO) in Treg cells led to spontaneous autoinflammation, immune cell activation, and diminished levels of FoxP3 in CD4+ T cells in mice. Loss of Pp6 in Treg cells exacerbated two classical mouse models of Treg-related autoinflammation. Mechanistically, Pp6 deficiency increased CpG motif methylation of the FoxP3 locus by dephosphorylating Dnmt1 and enhancing Akt phosphorylation at Ser473/Thr308, leading to impaired FoxP3 expression in Treg cells. In summary, our study proposes Pp6 as a critical positive regulator of FoxP3 that acts by decreasing DNA methylation of the FoxP3 gene enhancer and inhibiting Akt signaling, thus maintaining Treg cell stability and preventing autoimmune diseases.
RESUMO
Protein Phosphatase 6 down-regulation in keratinocytes is a pivotal event that amplifies the inflammatory circuits in psoriasis, indicating that restoration of protein phosphatase 6 can be a rational strategy for psoriasis treatment. Through the phenotypic screen, we here identify L-menthol that ameliorates psoriasis-like skin inflammation by increasing protein phosphatase 6 in keratinocytes. Target identification approaches reveal an indispensable role for the transcription factor hairy and enhancer of split 1 in governing the protein phosphatase 6-upregulating function of L-menthol in keratinocytes. The transcription factor hairy and enhancer of split 1 is diminished in the epidermis of psoriasis patients and imiquimod-induced mouse model, while L-menthol upregulates the transcription factor hairy and enhancer of split 1 by preventing its proteasomal degradation. Mechanistically, the transcription factor hairy and enhancer of split 1 transcriptionally activates the expression of immunoglobulin-binding protein 1 which promotes protein phosphatase 6 expression and inhibits its ubiquitination. Collectively, we discover a therapeutic compound, L-menthol, for psoriasis, and uncover the dysfunctional the transcription factor hairy and enhancer of split 1- immunoglobulin-binding protein 1- protein phosphatase 6 axis that contributes to psoriasis pathology by using L-menthol as a probe.
Assuntos
Mentol , Psoríase , Animais , Camundongos , Psoríase/metabolismo , Queratinócitos/metabolismo , Fatores de Transcrição/metabolismo , Imunoglobulinas/metabolismo , Modelos Animais de Doenças , Fatores de Transcrição HES-1/metabolismoRESUMO
Psoriasis is a chronic immune-mediated skin disorder with the nervous system contributing to its pathology. The neurogenic mediators of psoriasis are elusive, and whether the intervention of the cutaneous nervous system can treat psoriasis remains to be determined. In this study, we conducted a pilot study using an epidural injection of lidocaine to treat patients with psoriasis. Lidocaine treatment markedly reduced patients' clinical scores and improved an imiquimod-induced rat model of psoriasis as competent as systemic delivery of a TNF-α antibody. Imiquimod application elicited aberrant cutaneous nerve outgrowth and excessive generation of neuropeptide calcitonin gene-related peptide from dorsal root ganglion neurons, both of which were inhibited by epidural lidocaine treatment. Single-cell RNA sequencing unveiled the overrepresentation of calcitonin gene-related peptide receptors in dermal dendritic cell populations of patients with psoriasis. Through disturbing calcitonin gene-related peptide signaling, lidocaine inhibited IL-23 production by dendritic cells cocultured with dorsal root ganglion neurons. Thus, epidural nerve block with lidocaine demonstrates an effective therapy for psoriasis, which suppresses both inordinate sensory nerve growth in the inflamed skin and calcitonin gene-related peptide-mediated IL-23 production from psoriatic dendritic cells.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Células Dendríticas , Lidocaína , Psoríase , Células Receptoras Sensoriais , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Comunicação Celular , Imiquimode/efeitos adversos , Interleucina-23 , Lidocaína/uso terapêutico , Projetos Piloto , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , RatosRESUMO
Psoriasis is an incurable chronic inflammatory skin disorder. The imiquimod (IMQ)-induced mouse model of psoriasis is the most widely used model for drug discovery and pre-clinical studies of psoriasis. The inflamed and thickened skin frequently compromises the quality of single-cell suspensions generated from IMQ-induced skin lesions, which has an impact on subsequent analyses by flow cytometry. This protocol details the complete procedure for the establishment of a mouse model of psoriasis and flow cytometric detection of immune cells in the inflamed epidermis and dermis. For complete details on the use and execution of this protocol, please refer to Lou et al. (2020).
Assuntos
Citometria de Fluxo/métodos , Psoríase/imunologia , Psoríase/patologia , Aminoquinolinas/efeitos adversos , Animais , Citocinas/efeitos adversos , Derme/patologia , Modelos Animais de Doenças , Células Epidérmicas/patologia , Epiderme/patologia , Imiquimode/efeitos adversos , Inflamação/patologia , Infiltração Leucêmica/imunologia , Camundongos , Psoríase/induzido quimicamente , Pele/imunologia , Pele/patologiaRESUMO
Melanoma is a life-threatening cancer with limited treatments. Retinoic acid-inducible gene I (RIG-I) is a cytosolic pattern recognition receptor (PRR) crucial to RNA virus sensing, interferon production, and tumor suppression. Quercetin, a natural flavonoid, has particularly therapeutic interests to prevent and treat cancer, for its pharmacological effects against oxidant, inflammation, and angiogenesis. Quercetin was investigated for its anti-melanoma activity and potential mechanisms in this study. We found that quercetin inhibited mouse melanoma growth in vivo, and suppressed proliferation and promoted apoptosis of both B16 and A375 cells in vitro. Quercetin upregulated IFN-α and IFN-ß expression through activating RIG-I promoter in B16 cells. The induction of IFN-α and IFN-ß, which could be severely impaired by silencing RIG-I induced interferon stimulated genes (ISGs). Moreover, RIG-I likely amplifies antitumor effects by activating signal transduction and activator of transcription 1 (STAT1) in the IFN-JAK-STAT pathway in an autocrine and paracrine manner. Our study provided novel insights regarding biological and anti-proliferative activities of quercetin against melanoma, and we identified RIG-I as a potential target in anti-tumor therapies.
Assuntos
Proteína DEAD-box 58/metabolismo , Interferon Tipo I/metabolismo , Melanoma/metabolismo , Quercetina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Apoptose/genética , Linhagem Celular Tumoral , Proteína DEAD-box 58/genética , Modelos Animais de Doenças , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/tratamento farmacológico , Melanoma/etiologia , Melanoma/patologia , Melanoma Experimental , Camundongos , Regiões Promotoras Genéticas , Receptores Imunológicos , Ativação TranscricionalRESUMO
Many annotated long noncoding RNAs (lncRNAs) harbor predicted short open reading frames (sORFs), but the coding capacities of these sORFs and the functions of the resulting micropeptides remain elusive. Here, we report that human lncRNA MIR155HG encodes a 17-amino acid micropeptide, which we termed miPEP155 (P155). MIR155HG is highly expressed by inflamed antigen-presenting cells, leading to the discovery that P155 interacts with the adenosine 5'-triphosphate binding domain of heat shock cognate protein 70 (HSC70), a chaperone required for antigen trafficking and presentation in dendritic cells (DCs). P155 modulates major histocompatibility complex class II-mediated antigen presentation and T cell priming by disrupting the HSC70-HSP90 machinery. Exogenously injected P155 improves two classical mouse models of DC-driven auto inflammation. Collectively, we demonstrate the endogenous existence of a micropeptide encoded by a transcript annotated as "non-protein coding" and characterize a micropeptide as a regulator of antigen presentation and a suppressor of inflammatory diseases.
Assuntos
RNA Longo não Codificante , Animais , Apresentação de Antígeno , Proteínas de Choque Térmico HSP70/genética , Humanos , Inflamação/genética , Camundongos , Fases de Leitura Aberta , RNA Longo não Codificante/genéticaRESUMO
BACKGROUND: Psoriasis is a common chronic inflammatory skin disease which lacks effective strategies for the treatment. Natural compounds with biological activities are good tools to identify new targets with therapeutic potentials. Acetyl-11-keto-ß-boswellic acid (AKBA) is the most bioactive ingredient of boswellic acids, a group of compounds with anti-inflammatory and anti-cancer properties. Target identification of AKBA and metabolomics analysis of psoriasis helped to elucidate the molecular mechanism underlying its effect, and provide new target(s) to treat the disease. METHODS: To explore the targets and molecular mechanism of AKBA, we performed affinity purification, metabolomics analysis of HaCaT cells treated with AKBA, and epidermis of imiquimod (IMQ) induced mouse model of psoriasis and psoriasis patients. FINDINGS: AKBA directly interacts with methionine adenosyltransferase 2A (MAT2A), inhibited its enzyme activity, decreased level of S-adenosylmethionine (SAM) and SAM/SAH ratio, and reprogrammed onecarbon metabolism in HaCaT cells. Untargeted metabolomics of epidermis showed onecarbon metabolism was activated in psoriasis patients. Topical use of AKBA improved inflammatory phenotype of IMQ induced psoriasis-like mouse model. Molecular docking and site-directed mutagenesis revealed AKBA bound to an allosteric site at the interface of MAT2A dimer. INTERPRETATION: Our study extends the molecular mechanism of AKBA by revealing a new interacting protein MAT2A. And this leads us to find out the dysregulated onecarbon metabolism in psoriasis, which indicates the therapeutic potential of AKBA in psoriasis. FUND: The National Natural Science Foundation, the National Program on Key Basic Research Project, the Shanghai Municipal Commission, the Leading Academic Discipline Project of the Shanghai Municipal Education Commission.
Assuntos
Carbono/metabolismo , Metabolômica/métodos , Metionina Adenosiltransferase/antagonistas & inibidores , Psoríase/tratamento farmacológico , Triterpenos/administração & dosagem , Administração Tópica , Sítio Alostérico/efeitos dos fármacos , Animais , Linhagem Celular , Regulação para Baixo , Humanos , Imiquimode/efeitos adversos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Masculino , Metionina Adenosiltransferase/química , Camundongos , Modelos Moleculares , Simulação de Acoplamento Molecular , Conformação Proteica , Psoríase/induzido quimicamente , Psoríase/metabolismo , Triterpenos/farmacologiaRESUMO
Retinoic acid inducible-gene I (RIG-I) functions as one of the major sensors of RNA viruses. DDX58, which encodes the RIG-I protein, has been newly identified as a susceptibility gene in psoriasis. Here, we show that the activation of RIG-I by 5'ppp-dsRNA, its synthetic ligand, directly causes the production of IL-23 and triggers psoriasis-like skin disease in mice. Repeated injections of IL-23 to the ears failed to induce IL-23 production and a full psoriasis-like skin phenotype, in either germ-free or RIG-I-deficient mice. RIG-I is also critical for a full development of skin inflammation in imiquimod (IMQ)-induced psoriasis-like mouse model. Furthermore, RIG-I-mediated endogenous IL-23 production was mainly confined to the CD11c+ dendritic cells (DCs) via nuclear factor-kappa B (NF-κB) signaling, and stimulated RIG-I expression in an auto-regulatory feedback loop. Thus, our data suggest that the dysregulation in the antiviral immune responses of hosts through the innate pattern recognition receptors may trigger the skin inflammatory conditions in the pathophysiology of psoriasis.
Assuntos
Proteína DEAD-box 58/imunologia , Interleucina-23/imunologia , Psoríase/imunologia , Transdução de Sinais , Dermatopatias/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Células Dendríticas/imunologia , Células Dendríticas/patologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , NF-kappa B/imunologia , Psoríase/patologia , Infecções por Vírus de RNA/imunologia , Vírus de RNA/imunologia , Receptores Imunológicos , Pele/imunologia , Pele/patologia , Dermatopatias/patologia , Adulto JovemRESUMO
T helper 17 (Th17) cells play an important role in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Th17 cell differentiation from naïve T cells can be induced in vitro by the cytokines transforming growth factor ß1 and interleukin-6. However, it remains unclear whether other regulatory factors control the differentiation of Th17 cells. Mesenchymal stem cells (MSCs) have emerged as a promising candidate for inhibiting Th17 cell differentiation and autoimmune diseases. Despite the fact that several molecules have been linked to the immunomodulatory function of MSCs, many other key MSC-secreted regulators that are involved in inhibiting Th17 cell polarization are ill-defined. In this study, we demonstrated that the intraperitoneal administration of skin-derived MSCs (S-MSCs) substantially ameliorated the development of EAE in mice. We found that the proinflammatory cytokine tumor necrosis factor (TNF)-α, a key mediator in the pathophysiology of MS and EAE, was capable of promoting Th17 cell differentiation. Moreover, under inflammatory conditions, we demonstrated that S-MSCs produced high amounts of soluble TNF receptor 1 (sTNFR1), which binds TNF-α and antagonizes its function. Knockdown of sTNFR1 in S-MSCs decreased their inhibitory effect on Th17 cell differentiation ex vivo and in vivo. Thus, our data identified sTNFR1 and its target TNF-α as critical regulators for Th17 cell differentiation, suggesting a previously unrecognized mechanism for MSC therapy in Th17-mediated autoimmune diseases.