RESUMO
T cell-dependent liver injury is an important reason for the massive hepatic damage and cirrhosis. So far it is unclear whether the development of the disease could be efficiently suppressed by anti-inflammatory cytokine that modulates innate immune cells. Here we report that anti-inflammatory cytokine IL-37 could efficiently suppress the sustained hepatic expression of IFN-γ and TNF-α, two critical cytokines for inducing hepatocyte apoptosis and liver fibrosis in T cell-dependent liver injury. IL-37 could directly suppress IFN-γ/TLR4 ligand-induced M1 activation of macrophages, thus reducing the expression of pro-inflammatory cytokines TNF-α, IL-1ß, and IL-12. Moreover, IL-37 attenuated Th1 response in vivo and increased the expression of Th2 cytokines IL-4 and IL-13, which in turn promoted M2 activation of macrophages in the liver. The increase of M2 activation not only further reduced TNF-α, IL-1ß and IL-12 expression, but also increased IL-10 and IL-1Ra expression in macrophages, thus more efficiently suppressing the hepatic IFN-γ expression. By suppressing IFN-γ/TNF-α expression, IL-37 suppressed the up-regulation and activation of MLKL that drives hepatocellular necrosis in T cell-dependent liver damage. Accordingly, IL-37 efficiently reduced liver injury and hepatic inflammation after the repeated ConA challenge and the induction of autoimmune hepatitis, and also suppressed hepatic fibrosis resulting from the sustained liver damage. This study showed that the direct and indirect effect of IL-37 on macrophages could reduce the hepatic TNF-α expression, and also modulate IL-1ß/IL-12 and IL-10/IL-1Ra expression to suppress the hepatic IFN-γ expression, thus suppressing the development of T cell-dependent liver injury such as autoimmune hepatitis.
Assuntos
Anti-Inflamatórios/uso terapêutico , Hepatite Autoimune/tratamento farmacológico , Hepatócitos/fisiologia , Interleucina-1/uso terapêutico , Macrófagos/fisiologia , Linfócitos T/imunologia , Animais , Células Cultivadas , Concanavalina A , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Terapia de Imunossupressão , Interferon gama/metabolismo , Camundongos , Receptores de Interleucina-10/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Pulmonary fibrosis is an aggressive endstage disease. Transforming growth factorß1 (TGFß1) mediates lung ï¬broblast activation and is essential for the progress of pulmonary fibrosis. BML111, a lipoxinA4 (LXA4) receptor (ALX) agonist, has been reported to possess antiï¬brotic properties. The present study aimed to elucidate whether BML111 inhibits TGFß1induced mouse embryo lung ï¬broblast (NIH3T3 cell line) activation in vitro and bleomycin (BLM)induced pulmonary fibrosis in vivo. In vitro experiments demonstrated that BML111 treatment inhibits TGFß1induced NIH3T3 cell viability and the expression of smooth muscle α actin (αSMA), ï¬bronectin and total collagen. Furthermore, this suppressive effect was associated with mothers against decapentaplegic homolog (Smad)2/3, extracellular signalregulated kinase (ERK) and Akt phosphorylation interference. In vivo experiments revealed that BML111 treatment markedly improved survival rate and ameliorated the destruction of lung tissue structure. It also reduced interleukin1ß (IL1ß), tumor necrosis factorα (TNFα) and TGFß1 expression in the BLM intratracheal mouse model. In addition, the expression ofαSMA and extracellular matrix (ECM) deposition (total collagen, hydroxyproline and ï¬bronectin) were also suppressed following BML111 treatment. However, BOC2, an antagonist of ALX, partially weakened the effects of BML111. In conclusion, these results indicated that BML111 inhibits TGFß1induced ï¬broblasts activation and alleviates BLMinduced pulmonary fibrosis. Therefore, BML111 may be used as a potential therapeutic agent for pulmonary fibrosis treatment.
Assuntos
Fibroblastos/metabolismo , Ácidos Heptanoicos/farmacologia , Fibrose Pulmonar/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Linhagem Celular , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Masculino , Camundongos , Células NIH 3T3 , Prognóstico , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/patologia , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/farmacologia , Resultado do TratamentoRESUMO
Autoimmune hepatitis (AIH), a serious autoimmune liver disease, can be a lifelong illness, leading to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). So far the mechanisms for disease initiation are largely unknown. Here we report that the amplified non-AIH liver inflammation could promote the initiation of AIH due to the sustained increase of IL-6, IL-12, IL-4, and IL-25 in the liver. The liver injury resulting from virus (adenovirus) or chemicals (CCl4) could induce an amplified (stronger/long-lasting) hepatic inflammation by releasing the ligands for TLR2/TLR4. The amplified inflammation resulted in the increase of multiple cytokines and chemokines in the liver. Among them, the sustained increase of IL-6/IL-12 resulted in the activation of STAT3 and STAT4 in hepatic CD4+CD25+ Treg cells, thus suppressing Foxp3 gene expression to reduce the suppressive function of Treg cells in the liver, but not those in the spleen. The increase of IL-12 and the impairment of Treg function promoted Th1 response in presence of self-mimicking antigen (human CYP2D6). Intriguingly, the amplified inflammation resulted in the increase of IL-4 and IL-25 in the liver. The moderate increase of IL-4 was sufficient for cooperating with IL-25 to initiate Th2 response, but inefficient in suppressing Th1 response, favoring the initiation of autoimmune response. Consequently, either adenovirus/CYP2D6 or CCl4/CYP2D6 could induce the autoimmune response and AIH in the mice, leading to hepatic fibrosis. The findings in this study suggest that the amplified non-AIH inflammation in the liver could be a driving force for the initiation of autoimmune response and AIH.
Assuntos
Autoimunidade/imunologia , Hepatite Autoimune/imunologia , Inflamação/imunologia , Fígado/imunologia , Receptor 2 Toll-Like/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Feminino , Interleucinas/imunologia , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores/imunologiaRESUMO
BACKGROUND: Estrogen as well as CD4(+)Foxp3(+) regulatory T cells were shown to have a protective role not only in maintaining maternal-fetal tolerance but also against autoimmune diseases. We aimed to investigate whether the pregnancy levels of estrogen are enough to induce transplant tolerance as to maintain fetal-maternal tolerance. METHODS: We established H-Y skin graft transplantation in C57BL/6 ovariectomized mice that reconstituted with estrogen. Subsequently, consecutive daily estrogen injection was administrated. Tregs and the cytokines in the peripheral blood were detected by flow cytometry and ELISA pre- and post-transplant. RESULTS: The results indicated that pregnancy levels of estrogen could promote Tregs in secondary lymphoid organs and peripheral blood (P < 0.05) but not thymus (P > 0.05). The estrogen-treated recipients accepted H-Y skin grafts for more than 35 days (median survival time (MST): (44.0 ± 1.2) days) compared with estrogen-untreated mice (MST: (23.0 ± 1.6) days) (P < 0.05). It was also observed that estrogen up-regulated the expression of Foxp3, but did not affect CD3(+)CD8(+) effector T-cells in non-transplant mice. While in the presence of H-Y antigens, the expression of Foxp3 was more significant and CD3(+)CD8(+) effector T cells were decreased significantly (P < 0.05). Meanwhile, the up-regulated IL-10 and IL-4, and down-regulated IFN-γ could be observed (P < 0.05). CONCLUSIONS: Pregnancy levels of estrogen may promote the conversion of peripheral Tregs in secondary lymphoid organs, but show no effect on the natural Tregs production, differentiation and maturity in central lymphoid organs. Furthermore, pregnancy levels of estrogen could significantly prolong the survivals of H-Y skin grafts by the expansion of Tregs, suppression of CD3(+)CD8(+) effector T-cells and immune shift towards Th2 cytokines.
Assuntos
Citocinas/metabolismo , Sobrevivência de Enxerto/efeitos dos fármacos , Antígeno H-Y/imunologia , Transplante de Pele/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Fatores de Transcrição Forkhead/metabolismo , Antígeno H-Y/metabolismo , Imuno-Histoquímica , Interferon gama/metabolismo , Interleucina-10/metabolismo , Interleucina-4/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Ovariectomia , GravidezRESUMO
Two dodecapeptide amines: (WPRK)(3)NH(2)[WR-12] and (YPRK)(3)NH(2)[YR-12], and a 30-mer polypeptide amide (SP-30) were synthesized by solid-phase peptide methodology. DNase I footprinting studies on a 117-mer DNA showed that WR-12 and YR-12 bind selectively to DNA sequences in a manner similar to SP-30 which has a repeating SPK(R)K sequence. The most distinctive blockages seen with all three peptides occur at positions 26-30, 21-24 and 38-45 around sequences 5'-GAATT-3', 5'-TAAT-3' and 5'-AAAACGAC-3', respectively. However, it appears that YR-12 is better able to extend its recognition site to include CG pairs than is SP-30. At low concentrations YR-12 was able to induce enhanced rates of DNase I cleavage at regions surrounding some of its binding sites. To obtain further quantitative data supplementary to the footprinting work, equilibrium binding experiments were performed in which the binding of the two peptides to six decanucleotide duplexes was compared. Scatchard analyses indicated that WR-12 may be more selective for oligomers containing runs of consecutive purines or pyrimidines. On the other hand, YR-12 binds better to d(CTTAGACGTC)- d(GACGTCTAAG) than to the other oligomer duplexes, denoting selectivity for evenly distributed C/G and A/T sequences.