RESUMO
Despite the benefit of insulin, blockade of autoimmune attack and regeneration of pancreatic islets are ultimate goals for the complete cure of type 1 diabetes (T1D). Long-term consumption of ω-3 polyunsaturated fatty acids (PUFAs) is known to suppress inflammatory processes, making these fatty acids candidates for the prevention and amelioration of autoimmune diseases. Here, we explored the preventative and therapeutic effects of ω-3 PUFAs on T1D. In NOD mice, dietary intervention with ω-3 PUFAs sharply reduced the incidence of T1D, modulated the differentiation of Th cells and Tregs, and decreased the levels of IFN-γ, IL-17, IL-6, and TNF-α. ω-3 PUFAs exerted similar effects on the differentiation of CD4+ T cells isolated from human peripheral blood mononuclear cells. The regulation of CD4+ T cell differentiation was mediated at least in part through ω-3 PUFA eicosanoid derivatives and by mTOR complex 1 (mTORC1) inhibition. Importantly, therapeutic intervention in NOD mice through nutritional supplementation or lentivirus-mediated expression of an ω-3 fatty acid desaturase, mfat-1, normalized blood glucose and insulin levels for at least 182 days, blocked the development of autoimmunity, prevented lymphocyte infiltration into regenerated islets, and sharply elevated the expression of the ß cell markers pancreatic and duodenal homeobox 1 (Pdx1) and paired box 4 (Pax4). The findings suggest that ω-3 PUFAs could potentially serve as a therapeutic modality for T1D.
Assuntos
Autoimunidade/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Ácidos Graxos Ômega-3/farmacologia , Animais , Autoimunidade/genética , Glicemia/genética , Glicemia/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Caderinas/genética , Caderinas/imunologia , Citocinas/genética , Citocinas/imunologia , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/imunologia , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Endogâmicos NOD , Complexos Multiproteicos/genética , Complexos Multiproteicos/imunologia , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/imunologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/imunologia , Transativadores/genética , Transativadores/imunologiaRESUMO
CONTEXT: There is evidence that n-3 polyunsaturated fatty acids (n-3-PUFAs) can inhibit mTORC1, which should potentiate autophagy and eliminate NLRP3 inflammasome activity. OBJECTIVE: Evaluate the effect of a high-fat or high-fat/fructose diet with and without n-3-PUFAs on hepatic gene expression. MATERIALS AND METHODS: We examined the mRNA expression by RT-PCR of Mtor, Nlrp3, and other 22 genes associated with inflammation in rats livers after a 9-week diet. The dietary regimens were low-fat (control, CD), high-fat (HF), high-fat/fructose (HF-Fr), and also each of these supplemented with n-3-PUFAs (CD-n-3-PUFAs, HF-n-3-PUFAs, and HF-Fr-n-3-PUFAs). These data were processed by GeneMania and STRING databases. RESULTS: Compared to the control, the HF group showed a significant increase (between p < 0.05 and p < 0.0001) in 20 of these genes (Il1b, Il18, Rxra, Nlrp3, Casp1, Il33, Tnf, Acaca, Mtor, Eif2s1, Eif2ak4, Nfkb1, Srebf1, Hif1a, Ppara, Ppard, Pparg, Mlxipl, Fasn y Scd1), and a decrease in Sirt1 (p < 0.05). With the HF-Fr diet, a significant increase (between p < 0.05 and p < 0.005) was also found in the expression of 16 evaluated genes (Srebf1, Mlxipl, Rxra, Abca1, Il33, Nfkb1, Hif1a, Pparg, Casp1, Il1b, Il-18, Tnf, Ppard, Acaca, Fasn, Scd1), along with a decrease in the transcription of Mtor and Elovl6 (p < 0.05). Contrarily, many of the genes whose expression increased with the HF and HF-Fr diets did not significantly increase with the HF-n-3-PUFAs or HF-Fr-n-3-PUFAs diet. DISCUSSION AND CONCLUSION: We found the interrelation of the genes for the mTORC1 complex, the NLRP3 inflammasome, and other metabolically important proteins, and that these genes respond to n-3-PUFAs.
Assuntos
Gorduras na Dieta/farmacologia , Ácidos Graxos Ômega-3/farmacologia , Frutose/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamassomos/imunologia , Fígado/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , RNA Mensageiro/imunologia , Serina-Treonina Quinases TOR/imunologia , Animais , Regulação da Expressão Gênica/imunologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/imunologia , Ratos , Ratos Sprague-DawleyRESUMO
In this work we characterize the interaction of pomegranate hydrolyzable tannins (HT) with hen egg-white lysozyme (HEL) and determine the effects of non-covalent tannin-protein complexes on macrophage endocytosis, processing and presentation of antigen. We isolated HT from pomegranate and complex to HEL, the resulting non-covalent tannin-protein complex was characterized by gel electrophoresis and MALDI-TOF MS. Finally, cell culture studies and confocal microscopy imaging were conducted on the non-covalent pomegranate HT-HEL protein complexes to evaluate its effect on macrophage antigen uptake, processing and presentation to T-cell hybridomas. Our results indicate that non-covalent pomegranate HT-HEL protein complexes modulate uptake, processing and antigen presentation by mouse peritoneal macrophages. After 4 h of pre-incubation, only trace amounts of IL-2 were detected in the co-cultures treated with HEL alone, whereas a non-covalent pomegranate HT-HEL complex had already reached maximum IL-2 expression. Pomegranate HT may increase rate of endocytose of HEL and subsequent expression of IL-2 by the T-cell hybridomas.
Assuntos
Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/imunologia , Lythraceae/química , Lythraceae/imunologia , Muramidase/química , Muramidase/imunologia , Animais , Apresentação de Antígeno , Técnicas de Cocultura , Suplementos Nutricionais/análise , Proteínas do Ovo/química , Proteínas do Ovo/imunologia , Alimento Funcional/análise , Humanos , Hibridomas/imunologia , Macrófagos Peritoneais/imunologia , Camundongos , Complexos Multiproteicos/química , Complexos Multiproteicos/imunologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Linfócitos T/imunologiaRESUMO
Dried litchi pulp has been used in traditional remedies in China for many years to treat various diseases, and the therapeutic activity has been, at least partly, attributed to the presence of bioactive polysaccharides. Polysaccharide-protein complexes from vacuum freeze-(VF), vacuum microwave-(VM) and heat pump (HP) dried litchi pulp, which were coded as LP-VF, LP-VM and LP-HP, were comparatively studied on the physicochemical and immunomodulatory properties. LP-HP had a predominance of galactose, while glucose was the major sugar component in LP-VF and LP-VM. Compared with LP-VF and LP-VM, LP-HP contained more aspartate and glutamic in binding protein. LP-HP also exhibited a stronger stimulatory effect on splenocyte proliferation at 200 µg/mL and triggered higher NO, TNF-α and IL-6 secretion from RAW264.7 macrophages. Different drying methods caused the difference in physicochemical properties of polysaccharide-protein complexes from dried litchi pulp, which resulted in significantly different immunomodulatory activity. HP drying appears to be the best method for preparing litchi pulp to improve its immunomodulatory properties.
Assuntos
Proliferação de Células/efeitos dos fármacos , Complexos Multiproteicos/química , Polissacarídeos/química , Baço/citologia , Animais , Antioxidantes/química , Antioxidantes/farmacologia , China , Frutas/química , Humanos , Imunomodulação/efeitos dos fármacos , Litchi/química , Camundongos , Complexos Multiproteicos/imunologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/imunologiaRESUMO
CD18 integrins are adhesion molecules expressed on the cell surface of leukocytes and play a central role in the molecular mechanisms supporting leukocyte migration to zones of inflammation. Recently, it was discovered that CD11a/CD18 is shed from the leukocyte surface in models of inflammation. In this study, we show that shedding of human CD11/CD18 complexes is a part of synovial inflammation in rheumatoid arthritis and spondyloarthritis but not in osteoarthritis. In vivo and in vitro data suggest that the shedding is driven by TNF-α, which links the process to central events in the inflammatory response. The shed complexes contain multiple heterodimers of CD11/CD18, are variable in size, and differ according to the type of synovial inflammation. Furthermore, the differential structures determine the avidity of binding of the complexes to the ICAM-1. With the estimated concentrations of CD11/CD18 in plasma and synovial fluid a significant coverage of binding sites in ICAM-1 for CD18 integrins is expected. Based on cell adhesion experiments in vitro, we hypothesize that the large soluble complexes of CD11/CD18 act in vivo to buffer leukocyte adhesion by competing with the membrane-bound receptors for ICAM-1 binding sites. As reported here for synovial inflammation changes in the concentration or structure of these complexes should be considered as likely contributors to disease activity.
Assuntos
Artrite/metabolismo , Antígenos CD11/metabolismo , Antígenos CD18/metabolismo , Leucócitos/metabolismo , Membrana Sinovial/imunologia , Adulto , Artrite/imunologia , Artrite/patologia , Antígenos CD11/imunologia , Antígenos CD18/imunologia , Adesão Celular/imunologia , Membrana Celular/imunologia , Membrana Celular/metabolismo , Separação Celular , Epitopos/imunologia , Feminino , Citometria de Fluxo , Imunofluorescência , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Molécula 1 de Adesão Intercelular/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Leucócitos/imunologia , Masculino , Pessoa de Meia-Idade , Complexos Multiproteicos/imunologia , Complexos Multiproteicos/metabolismo , Membrana Sinovial/metabolismo , Membrana Sinovial/patologiaRESUMO
Because IL-1beta plays an important role in inflammation in human and murine arthritis, we investigated the contribution of the inflammasome components ASC, NALP-3, IPAF, and caspase-1 to inflammatory arthritis. We first studied the phenotype of ASC-deficient and wild-type mice during Ag-induced arthritis (AIA). ASC(-/-) mice showed reduced severity of AIA, decreased levels of synovial IL-1beta, and diminished serum amyloid A levels. In contrast, mice deficient in NALP-3, IPAF, or caspase-1 did not show any alteration of joint inflammation, thus indicating that ASC associated effects on AIA are independent of the classical NALP-3 or IPAF inflammasomes. Because ASC is a ubiquitous cytoplasmic protein that has been implicated in multiple cellular processes, we explored other pathways through which ASC may modulate inflammation. Ag-specific proliferation of lymph node and spleen cells from ASC-deficient mice was significantly decreased in vitro, as was the production of IFN-gamma, whereas IL-10 production was enhanced. TCR ligation by anti-CD3 Abs in the presence or absence of anti-CD28 Abs induced a reduction in T cell proliferation in ASC(-/-) T cells compared with wild-type ones. In vivo lymph node cell proliferation was also significantly decreased in ASC(-/-) mice, but no effects on apoptosis were observed either in vitro or in vivo in these mice. In conclusion, these results strongly suggest that ASC modulates joint inflammation in AIA through its effects on cell-mediated immune responses but not via its implication in inflammasome formation.
Assuntos
Proteínas Reguladoras de Apoptose/deficiência , Artrite Experimental/etiologia , Proteínas de Ligação ao Cálcio/deficiência , Proteínas de Transporte/genética , Caspase 1/deficiência , Proteínas do Citoesqueleto/fisiologia , Inflamação/etiologia , Animais , Antígenos/toxicidade , Artrite Experimental/patologia , Proteínas Adaptadoras de Sinalização CARD , Proliferação de Células , Artropatias/patologia , Linfonodos/patologia , Camundongos , Camundongos Knockout , Complexos Multiproteicos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR , Baço/patologiaRESUMO
Antibromelain polyclonal antibodies against stem bromelain were raised in male albino rabbits and the Fab monomers isolated from the IgG of the immune sera as reported in our earlier communication (Gupta, P., Khan, R. H., and Saleemuddin, M. (2003) Biochim. Biophys. Acta, 1646, 131-135). Further, as evident from that communication bromelain:Fab complex has 1 : 1 stoichiometry. The stability of bromelain:Fab complex (1 : 1 stoichiometry) was investigated by far and near-UV CD and fluorescence measurements. Addition of up to 1.8 M NaCl caused no significant changes in fluorescence signals and near-UV CD peak pattern. However, the spectral studies together with gel filtration studies suggest dissociation of the complex beyond 5% (v/v) methanol. These results show that hydrophobic interactions play a pronounced role in the binding of Fab to bromelain while electrostatic interactions may be less crucial.