RESUMEN
Glucocorticoids remain a mainstay of modern medicine due to their ability to broadly suppress immune activation. However, they cause severe adverse effects that warrant urgent development of a safer alternative. The glucocorticoid-induced leucine zipper (GILZ) gene, TSC22D3, is one of the most highly upregulated genes in response to glucocorticoid treatment, and reduced GILZ mRNA and protein levels are associated with increased severity of inflammation in systemic lupus erythematosus (SLE), Ulcerative Colitis, Psoriasis, and other autoimmune/autoinflammatory diseases. Here, we demonstrate that low GILZ permits expression of a type I interferon (IFN) signature, which is exacerbated in response to TLR7 and TLR9 stimulation. Conversely, overexpression of GILZ prevents IFN-stimulated gene (ISG) up-regulation in response to IFNα. Moreover, GILZ directly binds STAT1 and prevents its nuclear translocation, thereby negatively regulating IFN-induced gene expression and the auto-amplification loop of the IFN response. Thus, GILZ powerfully regulates both the expression and action of type I IFN, suggesting restoration of GILZ as an attractive therapeutic strategy for reducing reliance on glucocorticoids.
Asunto(s)
Interferón Tipo I , Lupus Eritematoso Sistémico , Psoriasis , Regulación de la Expresión Génica , Glucocorticoides/metabolismo , Glucocorticoides/farmacología , Glucocorticoides/uso terapéutico , Humanos , Interferón Tipo I/genética , Interferón Tipo I/metabolismo , Lupus Eritematoso Sistémico/metabolismo , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/metabolismoRESUMEN
Studies have highlighted a critical role for autophagy in the regulation of multiple cytokines. Autophagy inhibits the release of interleukin (IL)-1 family cytokines, including IL-1α, IL-1ß and IL-18, by myeloid cells. This, in turn, impacts the release of other cytokines by myeloid cells, as well as other cells of the immune system, including IL-22, IL-23, IL-17 and interferon-γ. Here, we assessed the impact of genetic depletion of the autophagy gene Atg7 in myeloid cells on acute and chronic inflammation. In a model of acute lipopolysaccharide-induced endotoxemia, loss of autophagy in myeloid cells resulted in increased release of proinflammatory cytokines, both locally and systemically. By contrast, loss of Atg7 in myeloid cells in the Lyn-/- model of lupus-like autoimmunity resulted in reduced systemic release of IL-6 and IL-10, with no effects on other cytokines observed. In addition, Lyn-/- mice with autophagy-deficient myeloid cells showed reduced expression of autoantibodies relevant to systemic lupus erythematosus, including anti-histone and anti-Smith protein. In vitro, loss of autophagy, through pharmacological inhibition or small interfering RNA against Becn1, inhibited IL-10 release by human and mouse myeloid cells. This effect was evident at the level of Il10 messenger RNA expression. Our data highlight potentially important differences in the role of myeloid cell autophagy in acute and chronic inflammation and demonstrate a direct role for autophagy in the production and release of IL-10 by macrophages.
Asunto(s)
Inflamación , Interleucina-10 , Animales , Autofagia , Citocinas/metabolismo , Humanos , Interleucina-10/genética , Ratones , Células MieloidesRESUMEN
Glucocorticoid-induced leucine zipper (GILZ) mimics many of the anti-inflammatory effects of glucocorticoids, suggesting it as a point of therapeutic intervention that could bypass GC adverse effects. We previously reported that GILZ down-regulation is a feature of human SLE, and loss of GILZ permits the development of autoantibodies and lupus-like autoimmunity in mice. To further query the contribution of GILZ to protection against autoimmune inflammation, we studied the development of the lupus phenotype in Lyn-deficient (Lyn-/-) mice in which GILZ expression was genetically ablated. In Lyn-/- mice, splenomegaly, glomerulonephritis, anti-dsDNA antibody titres and cytokine expression were exacerbated by GILZ deficiency, while other autoantibody titres and glomerular immune complex deposition were unaffected. Likewise, in patients with SLE, GILZ was inversely correlated with IL23A, and in SLE patients not taking glucocorticoids, GILZ was also inversely correlated with BAFF and IL18. This suggests that at the onset of autoimmunity, GILZ protects against tissue injury by modulating pro-inflammatory pathways, downstream of antibodies, to regulate the cycle of inflammation in SLE.
Asunto(s)
Citocinas/genética , Regulación de la Expresión Génica , Mediadores de Inflamación/metabolismo , Factores de Transcripción/metabolismo , Animales , Complejo Antígeno-Anticuerpo/efectos adversos , Complejo Antígeno-Anticuerpo/inmunología , Autoanticuerpos/inmunología , Biomarcadores , Citocinas/metabolismo , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Inmunohistoquímica , Lupus Eritematoso Sistémico/etiología , Lupus Eritematoso Sistémico/metabolismo , Lupus Eritematoso Sistémico/patología , Nefritis Lúpica/etiología , Nefritis Lúpica/metabolismo , Nefritis Lúpica/patología , Ratones , Ratones Noqueados , Especificidad de ÓrganosRESUMEN
Inflammatory bowel disease (IBD) is an inflammatory disorder caused by hyperactivation of effector immune cells that produce high levels of proinflammatory cytokines. The aims of our study were to determine whether orally administered blueberry extract (BE) could attenuate or prevent the development of experimental colitis in mice and to elucidate the mechanism of action. Female Balb/C mice (n=7) were randomized into groups differing in treatment conditions (prevention and treatment) and dose of BE (50 mg/kg body weight). Acute ulcerative colitis was induced by oral administration of 3% dextran sodium sulfate for 7 days in drinking water. Colonic mucosal injury was assessed by clinical, macroscopic, biochemical and histopathological examinations. BE significantly decreased disease activity index and improved the macroscopic and histological score of colons when compared to the colitis group (P<.05). BE markedly attenuated myeloperoxidase accumulation (colitis group 54.97±2.78 nmol/mg, treatment group 30.78±1.33 nmol/mg) and malondialdehyde in colon and prostaglandin E2 level in serum while increasing the levels of superoxide dismutase and catalase (colitis group 11.94±1.16 U/ml, BE treatment group 16.49±0.39 U/ml) compared with the colitis group (P<.05). mRNA levels of the cyclooxygenase (COX)-2, interferon-γ, interleukin (IL)-1ß and inducible nitric oxide synthase cytokines were determined by reverse transcriptase polymerase chain reaction. Immunohistochemical analysis showed that BE attenuates the expression of COX-2 and IL-1ß in colonic tissue. Moreover, BE reduced the nuclear translocation of nuclear transcription factor kappa B (NF-κB) by immunofluorescence analysis. Thus, the anti-inflammatory effect of BE at colorectal sites is a result of a number of mechanisms: antioxidation, down-regulation of the expression of inflammatory mediators and inhibition of the nuclear translocation of NF-κB.
Asunto(s)
Antioxidantes/metabolismo , Arándanos Azules (Planta)/química , Colitis Ulcerosa/prevención & control , Sulfato de Dextran/toxicidad , Mediadores de Inflamación/metabolismo , Extractos Vegetales/uso terapéutico , Animales , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/metabolismo , Femenino , RatonesRESUMEN
Apigenin, a nonmutagenic flavonoid, has been found to have antitumor properties and is therefore particularly relevant for the development of chemotherapeutic agents for cancers. In this study, time- and dose-dependent cell viability and cytotoxicity were assessed to determine the effects of apigenin on A2058 and A375 melanoma cells. Melanoma cells were pretreated with different concentrations of apigenin and analyzed for morphological changes, anoikis induction, cell migration, and levels of proteins associated with apoptosis. Apigenin reduced integrin protein levels and inhibited the phosphorylation of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK1/2), which induce anoikis in human cutaneous melanoma cells. Apigenin exhibited dose-dependent inhibition of melanoma cell migration, unlike untreated controls. Furthermore, apigenin treatment increased apoptotic factors such as caspase-3 and cleaved poly(ADP-ribose) polymerase in a dose-dependent manner, demonstrating the metastasis of melanoma cells. Our results provide a new insight into the mechanisms by which apigenin prevents melanoma metastasis by sensitizing anoikis induced by the loss of integrin proteins in the FAK/ERK1/2 signaling pathway. These findings elucidate the related mechanisms and suggest the potential of apigenin in developing clinical treatment strategies against malignant melanoma.
Asunto(s)
Anoicis/efectos de los fármacos , Apigenina/farmacología , Movimiento Celular/efectos de los fármacos , Proteína-Tirosina Quinasas de Adhesión Focal/antagonistas & inhibidores , Integrinas/antagonistas & inhibidores , Melanoma/patología , Apoptosis/efectos de los fármacos , Western Blotting , Proliferación Celular/efectos de los fármacos , Proteína-Tirosina Quinasas de Adhesión Focal/genética , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Humanos , Integrinas/genética , Integrinas/metabolismo , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales CultivadasRESUMEN
Ganoderma lucidum is a popular medicinal mushroom with anti-inflammatory potential. In the present study, the aim was to determine the anti-inflammatory effect and mode of action of G. lucidum grown on germinated brown rice (GLBR) in a mouse model of colitis. It was shown that GLBR suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-stimulated macrophages and decreased the expression of COX-2, TNF-α, iNOS, IL-1ß, IL-6, and IL-10 mRNAs. GLBR also inhibited activation of p38, ERK, JNK, MAPKs, and nuclear factor kappa-B (NF-κB). In a mouse model of colitis, colonic mucosal injury was evaluated using macroscopic, biochemical, and histopathological testing. Disease activity index (DAI), macroscopic score, and histological score significantly decreased upon GLBR treatment. Moreover, immunofluorescence studies indicated that DSS activates nuclear translocation of NF-κB in colon tissue, which is attenuated by GLBR extract. These findings suggest that GLBR is protective against colitis via inhibition of MAPK phosphorylation and NF-κB activation.
Asunto(s)
Antiinflamatorios/farmacología , Oryza/microbiología , Reishi/química , Animales , Ciclooxigenasa 2/metabolismo , Dinoprostona/metabolismo , Modelos Animales de Enfermedad , Interleucina-10 , Interleucina-1beta/inmunología , Interleucina-6/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Masculino , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Óxido Nítrico/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
We aimed to investigate the antioxidant and acetylcholinesterase inhibitory activities of the anthocyanin rich extract of grape skin. Grape skin anthocyanin (GSA) neutralized free radicals in different test systems, such as 2,-2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, to form complexes with Fe2+ preventing 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced erythrocyte hemolysis and oxidative DNA damage. Moreover, GSA decreased reactive oxygen species (ROS) generation in isolated mitochondria thus inhibiting 2',-7'-dichlorofluorescin (DCFH) oxidation. In an in vivo study, female BALB/c mice were administered GSA, at 12.5, 25, and 50 mg per kg per day orally for 30 consecutive days. Herein, we demonstrate that GSA administration significantly elevated the level of antioxidant enzymes in mice sera, livers, and brains. Furthermore, GSA inhibited acetylcholinesterase (AChE) in the in vitro assay with an IC50 value of 363.61 µg/mL. Therefore, GSA could be an excellent source of antioxidants and its inhibition of cholinesterase is of interest with regard to neurodegenerative disorders such as Alzheimer's disease.
Asunto(s)
Acetilcolinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Depuradores de Radicales Libres/farmacología , Extractos Vegetales/farmacología , Vitis/química , Animales , Benzotiazoles/química , Compuestos de Bifenilo/química , Inhibidores de la Colinesterasa/química , Daño del ADN , Evaluación Preclínica de Medicamentos , Eritrocitos/efectos de los fármacos , Eritrocitos/fisiología , Femenino , Depuradores de Radicales Libres/química , Frutas/química , Hemólisis , Concentración 50 Inhibidora , Ratones Endogámicos BALB C , Mitocondrias Hepáticas/efectos de los fármacos , Mitocondrias Hepáticas/metabolismo , Oxidación-Reducción , Estrés Oxidativo , Picratos/química , Extractos Vegetales/química , Ácidos Sulfónicos/químicaRESUMEN
In this study, the acetylcholinesterase inhibition and in vitro and in vivo antioxidant activities of Ganoderma lucidum grown on germinated brown rice (GLBR) were evaluated. In antioxidant assays in vitro, GLBR was found to have strong metal chelating activity, DPPH, ABTS, hydroxyl and superoxide radical scavenging activity. Cell-based antioxidant methods were used, including lipid peroxidation on brain homogenate and AAPH-induced erythrocyte haemolysis. In antioxidant assays in vivo, mice were administered with GLBR and this significantly enhanced the activities of antioxidant enzymes in the mice sera, livers and brains. The amount of total phenolic and flavonoid compounds were 43.14 mg GAE/g and 13.36 mg CE/g dry mass, respectively. GLBR also exhibited acetylcholinesterase inhibitory activity. In addition, HPLC analyses of GLBR extract revealed the presence of different phenolic compounds. These findings demonstrate the remarkable potential of GLBR extract as valuable source of antioxidants which exhibit interesting acetylcholinesterase inhibitory activity.