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1.
Our previous study has shown that reduced insulin resistance (IR) was one of the possible mechanisms for the therapeutic effect of silibinin on non-alcoholic fatty liver disease (NAFLD) in rats. In the present study, we investigated the pathways of silibinin in regulating hepatic glucose production and IR amelioration. Forty-five 4- to 6-week-old male Sprague Dawley rats were divided into a control group, an HFD group (high-fat diet for 6 weeks) and an HFD + silibinin group (high-fat diet + 0.5 mg kg-1·day-1 silibinin, starting at the beginning of the protocol). Both subcutaneous and visceral fat was measured. Homeostasis model assessment-IR index (HOMA-IR), intraperitoneal glucose tolerance test and insulin tolerance test (ITT) were performed. The expression of adipose triglyceride lipase (ATGL) and of genes associated with hepatic gluconeogenesis was evaluated. Silibinin intervention significantly protected liver function, down-regulated serum fat, and improved IR, as shown by decreased HOMA-IR and increased ITT slope. Silibinin markedly prevented visceral obesity by reducing visceral fat, enhanced lipolysis by up-regulating ATGL expression and inhibited gluconeogenesis by down-regulating associated genes such as Forkhead box O1, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. Silibinin was effective in ameliorating IR in NAFLD rats. Reduction of visceral obesity, enhancement of lipolysis and inhibition of gluconeogenesis might be the underlying mechanisms.  相似文献   

2.
The aim of this study was to quantify the proportion of regulatory T cells (Treg) and cytokine expression by peripheral blood mononuclear cells (PBMCs) in patients with active non-infectious uveitis, and to evaluate the effect of in-vitro treatment with infliximab, dexamethasone and cyclosporin A on Treg levels and cytokine production in PBMCs from uveitis patients and healthy subjects. We included a group of 21 patients with active non-infectious uveitis and 18 age-matched healthy subjects. The proportion of forkhead box protein 3 (FoxP3)+ Treg cells and intracellular tumour necrosis factor (TNF)-α expression in CD4+ T cells was determined by flow cytometry. PBMCs were also either rested or activated with anti-CD3/anti-CD28 and cultured in the presence or absence of dexamethasone, cyclosporin A and infliximab. Supernatants of cultured PBMCs were collected and TNF-α, interleukin (IL)-10, IL-17 and interferon (IFN)-γ levels were measured by enzyme-linked immunosorbent assay (ELISA). No significant differences were observed in nTreg levels between uveitis patients and healthy subjects. However, PBMCs from uveitis patients produced significantly higher amounts of TNF-α and lower amounts of IL-10. Dexamethasone treatment in vitro significantly reduced FoxP3+ Treg levels in PBMCs from both healthy subjects and uveitis patients, and all tested drugs significantly reduced TNF-α production in PBMCs. Dexamethasone and cyclosporin A significantly reduced IL-17 and IFN-γ production in PBMCs and dexamethasone up-regulated IL-10 production in activated PBMCs from healthy subjects. Our results suggest that PBMCs from patients with uveitis express more TNF-α and less IL-10 than healthy subjects, and this is independent of FoxP3+ Treg levels. Treatment with infliximab, dexamethasone and cyclosporin A in vitro modulates cytokine production, but does not increase the proportion of FoxP3+ Treg cells.  相似文献   

3.
Background/AimsNonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) characterized by hepatic steatosis, inflammation, hepatocellular injury, and fibrosis. We aimed to investigate the usefulness of a key biomarker, lipocalin-2 (LCN2), for the detection of NASH progression.MethodsA mouse NASH model was established using a high-fat diet and a high-sugar drinking water. Gene expression profile of the NASH model was analyzed using RNA sequencing. Moreover, 360 NAFLD patients (steatosis, 83; NASH, 277), 40 healthy individuals, and 87 patients with alcoholic fatty liver disease were recruited.ResultsInflammatory infiltration, focal necrosis in the leaflets, steatosis, and fibrosis were documented in the mouse liver. In total, 504 genes were differentially expressed in the livers of NASH mice, and showed significant functional enrichment in the inflammation-related category. Upregulated liver LCN2 was found to be significantly interactive with various interleukins and toll-like receptors. Serum LCN2 levels were significantly increased in NAFLD patients. Serum LCN2 levels were correlated with steatosis, intralobular inflammation, semiquantitative fibrosis score, and nonalcoholic fatty liver disease activity score. The area under the curve of serum LCN2 was 0.987 with a specificity of 100% and a sensitivity of 93.5% for NASH diagnosis, and 0.977 with almost the same specificity and sensitivity for steatosis.ConclusionsLCN2 might be involved in the transition from NAFL to NASH by mediating inflammation. Serum LCN2 levels might be a novel biomarker for the diagnosis of NASH.  相似文献   

4.
Regulatory T cells (CD4+CD25+FoxP3+-Treg cells) are important regulators of tolerance induction during pregnancy. We now found that the number of CD4+CD25+FoxP3+-Treg cells decreases during normal course of pregnancy and even more so in women affected by preeclampsia. The functional activity of these CD4+CD25+-Treg cells was significantly reduced in comparison to those of healthy pregnants. Further analysis revealed two Treg subsets that differed with regard to the FoxP3 and CD25 expression. The percentage of both, CD4+CD25+FoxP3high+-Treg and CD4+CD25high+FoxP3+, was maximal in the first and second trimenon, but declined severely in the third trimenon. In preeclamptic women the population of CD4+CD25high+FoxP3+-Treg cells was particularly apparent, while the population of CD4+CD25+FoxP3high+-Treg cells was significantly decreased. We propose that CD4+CD25+FoxP3high+- and CD4+CD25high+FoxP3+-Treg cell populations represent distinct Treg cell subsets, and that disturbances in the balance of these two Treg cell subsets are associated with the presence of preeclampsia, but not HELLP-syndrome.  相似文献   

5.
Dendritic cells (DCs) regulate immunity and immune tolerance in vivo. However, the mechanisms of DC-mediated tolerance have not been fully elucidated. Here, we demonstrate that intravenous (i.v.) transfer of bone marrow-derived DCs pulsed with myelin oligodendrocyte glycoprotein (MOG) peptide blocks the development of experimental autoimmune encephalomyelitis in C57BL/6J mice. i.v. transfer of MOG-pulsed DCs leads to the down-regulation of the production of IL-17A and IFN-γ and up-regulation of IL-10 secretion. The development of regulatory T cells (Tregs) is facilitated via up-regulation of FoxP3 expression and production of IL-10. The number of suppressive CD4+IL-10+IFN-γ+ T cells is also improved. The expression of OX40, CD154, and CD28 is down-regulated, but the expression of CD152, CD80, PD-1, ICOS, and BTLA is up-regulated on CD4+ T cells after i.v. transfer of immature DCs. The expression of CCR4, CCR5, and CCR7 on CD4+ T cells is also improved. Our results suggest that immature DCs may induce tolerance via facilitating the development of CD4+FoxP3+ Tregs and suppressive CD4+IL-10+IFN-γ+ T cells in vivo.  相似文献   

6.
The HIV-1 envelope glycoprotein (gp120) is known to induce antigen-specific and non-specific CD4+ T cell anergy. We found that early T cell activation, as indicated by HLA-DP expression in the early G1 (G1A) phase of the cell cycle, and the inhibition of mitogen-mediated IL-2 production induced by gp120, required TNF-α produced by gp120-stimulated macrophages. In the presence of an antibody to TNF-α, these changes induced by gp120 were inhibited, while recombinant TNF-α induced similar abnormalities of CD4+ T cells, even in the absence of gp120. On the other hand, inhibition of the mixed lymphocyte reaction (MLR) in CD4+ T cells by gp120, which may be related to gp120-mediated down-regulation of CD4 expression on T cells and activation of protein tyrosine kinase p56lck in CD4+ T cells, was observed even in the absence of macrophage-derived TNF-α induced by gp120. These observations indicate that both TNF-α-dependent and independent events contribute to gp120-mediated CD4+ T cell anergy, and TNF-α appears to play an important role in inducing CD4+ T cell anergy in HIV-1 infection.  相似文献   

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8.
The aim of this study was to examine the numbers of CD4+CD25forkhead box protein 3 (FoxP3)+, CD4+CD25+FoxP3+ and CD4+CXCR5+FoxP3+ T cells in patients with new-onset systemic lupus erythematosus (SLE). The numbers of CD4+CD25FoxP3+, CD4+CD25+FoxP3+ and CD4+CXCR5+FoxP3+ T cells and the concentrations of serum interleukin (IL)-10 in 23 patients and 20 healthy controls (HC) were measured. The potential correlations between CD4+FoxP3+ T cells, serum IL-10 and clinical measures in SLE patients were analysed. In comparison with that in the HC, significantly reduced numbers of CD4+CD25+FoxP3+ and CD4+CXCR5+FoxP3+ T cells, but increased numbers of CD4+CD25FoxP3+ T cells, were detected, accompanied by significantly lower levels of serum IL-10 in the patients. Stratification analysis indicated the numbers of CD4+CD25+FoxP3+ and CD4+CXCR5+FoxP3+ T cells and serum IL-10 levels in the patients with seropositive anti-dsDNA were significantly less than that in those with seronegative anti-dsDNA. Treatment with the anti-SLE therapy, particularly with prednisone, leflunomide and methotrexate, significantly improved the imbalance of these types of FoxP3+ T cells and increased the concentrations of serum IL-10 in the drug-responding patients. The numbers of CD4+CD25+FoxP3+ T cells were correlated negatively with the values of SLE disease activity index (SLEDAI), whereas the numbers of CD4+CD25FoxP3+ T cells were correlated positively with the values of SLEDAI, erythrocyte sedimentation rate (ESR) and serum C3. In addition, the concentrations of serum IL-10 were correlated positively with the numbers of CD4+CD25+FoxP3+ T cells, but negatively with the values of SLEDAI, serum C3, CRP and ESR in these patients. Our data indicate that the imbalance of different types of FoxP3+CD4+ T cells may contribute to the development of SLE in Chinese patients.  相似文献   

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10.
Non-alcoholic fatty liver disease (NAFLD) is strongly associated with obesity and the metabolic syndrome. It encompasses a clinico-pathologic spectrum of conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). The latter develops upon pro-inflammatory cell infiltration and is widely considered as the first relevant pathophysiological step in NAFLD-progression. The chemokine monocyte chemoattractant protein 1 (MCP-1) plays an important role in the progression of hepatic inflammation and fibrosis, and both increased hepatic expression and circulating serum levels have been described in NASH. Here, we aimed to investigate MCP-1 expression in simple hepatic steatosis. Upon feeding a high-fat diet mice developed hepatic steatosis in the absence of significant hepatic inflammation, but elevated hepatic MCP-1 expression compared to control mice fed a standard chow. Interestingly, high-fat diet fed mice had significantly higher MCP-1 serum levels, and MCP-1 mRNA expression was significantly increased in visceral adipose tissue. Furthermore, MCP-1 serum levels were also elevated in patients with ultrasound-diagnosed NAFLD and correlated with the body-mass index and fasting glucose. In conclusion, our data indicate both the liver and adipose tissue as cellular sources of elevated circulating MCP-1 levels already in the early phase of hepatic steatosis. Since MCP-1 derived from visceral adipose tissue reaches the liver via portal circulation at high concentrations it may significantly contribute to the progression of simple steatosis to NASH.  相似文献   

11.
Vitamin C has been found to stimulate dendritic cells (DCs) to secrete more IL-12 and thereby drive naïve CD4+ T cells to differentiate into Th1 cells. In the present study, we evaluated the effect of these vitamin C-treated DCs on CD8+ T cell differentiation both in vitro and in vivo. Mouse bone marrow-derived DCs were prepared in the presence of GM-CSF and IL-15. With vitamin C treatment, these DCs, when LPS-stimulated, secreted more IL-12p70 and IL-15 than did untreated DCs. And when co-cultured with T cells, they yielded a higher frequency of IFN-γ+ CD8+ T cells. Moreover, we found that administering vitamin C-treated and tumor lysate-loaded DCs into mice yielded a higher frequency of CD44high CD62Llow CD8+ effector and effector memory T cells, which showed an increased ex vivo killing effect of the tumor cells. These DCs also elicited enhanced protective effects against inoculated tumor cells, most probably by way of the increased cytotoxic T cells, as was revealed by the decreased growth of the inoculated tumor cells in these mice. This ex vivo vitamin C treatment effect on DCs can be considered as a strategy for boosting DC vaccination potency against tumors.  相似文献   

12.
目的:探讨脂肪酸转运酶/白细胞分化抗原36(fatty acid translocase/CD36,FAT/CD36)在高脂饮食诱导的小鼠脂肪组织炎症中的作用。方法:将6周龄雄性C57BL/6J小鼠分别随机分为普通饮食组和高脂饮食组,喂养14周后,ELISA测定血清游离脂肪酸(FFA)含量,应用荧光实时定量PCR和Western blotting检测脂肪组织中FAT/CD36及炎症/趋化因子(IL-1β、IL-6、TNF-α、MCP-1、MIP-1)mRNA和蛋白的表达,免疫组织化学染色检测脂肪组织巨噬细胞浸润,比较高脂喂养14周的野生型小鼠和CD36基因敲除小鼠的脂肪组织炎症反应情况。结果:与普通饮食组相比,高脂饮食能增强C57BL/6J小鼠脂肪组织的FAT/CD36及炎症/趋化因子的表达,促进巨噬细胞在脂肪组织的浸润。与高脂饮食喂养的野生型小鼠相比,CD36基因敲除小鼠的脂肪组织炎症因子、趋化因子表达明显降低,脂肪组织巨噬细胞浸润减少。结论:高脂饮食通过上调脂肪组织FAT/CD36的表达激活了脂肪组织炎症。  相似文献   

13.
Sally A Huber 《Immunology》2009,127(4):567-576
Coxsackievirus B3 (CVB3) causes severe myocarditis in BALB/c mice which depends upon CD4+ T helper type 1 [Th1; i.e. interferon-γ+ (IFN-γ+)] and γδ+ cells. Depleting γδ+ cells using anti-γδ antibody suppresses myocarditis and CD4+ IFN-γ+ cell numbers in the spleen and heart of infected mice while increasing CD4+ FoxP3+ cells. Mice deficient in γδ+ cells have increased numbers of naïve (CD44lo CD62Lhi) and fewer effector (CD44hi CD62lo) memory CD4+ cells than infected γδ+-cell-sufficient mice. Virus neutralizing antibody titres are not significantly different between γδ+ T-cell-sufficient and -deficient animals. To confirm that the memory cell response differs in acutely infected mice lacking γδ+ cells, CD4+ cells were purified and adoptively transferred into naïve recipients, which were rested for 4 weeks then infected with CVB3. Recipients given either 0·5 × 106 or 1·0 × 106 CD4+ from infected donors developed over twice the severity myocarditis and 10-fold less cardiac virus titre compared with recipients given equivalent numbers of CD4+ cells from infected and γδ+-cell-depleted donor animals. Additionally, to show that more functionally active T regulatory cells are present in γδ+ T-cell-depleted mice, CD4+ CD25+ and CD4+ CD25 cells were isolated and adoptively transferred into infected recipients. Mice receiving CD4+ CD25+ cells from γδ+ T-cell-depleted donors developed significantly less myocarditis and CD4+ Th1 cell responses compared with mice receiving equal numbers of CD4+ CD25+ cells from infected γδ+ T-cell-sufficient animals. This study shows that γδ+ cells promote CD4+ IFN-γ+ acute and memory responses by limiting FoxP3+ T regulatory cell activation.  相似文献   

14.
Concomitantly to the obesity epidemic, nonalcoholic fatty liver disease (NAFLD) has become the leading cause of liver disease in children. NAFLD encompasses a spectrum of histological damage ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), with possible progression to cirrhosis. There is growing evidence that the immune system plays a pivotal role in the initiation and progression to NASH but the cellular nature of the hepatic inflammation is still unknown. The present study includes 34 children with biopsy-proven NAFLD. Liver damage was evaluated by the NAFLD activity score (NAS), and the inflammatory infiltrate was characterized by immunohistochemistry for CD45, CD3 and CD163 which are markers of leukocytes, T cells and activated Kupffer cells/macrophages, respectively. Our results have shown that CD45+ (P<0.0001) and CD163+ (P<0.0001) cells were markedly increased in children with severe histological activity (NAS≥5) compared to children with lower activity (NAS<5), whereas CD3+ cells were significantly lower (P<0.01) in children with severe histological activity. There was a significant association between the numbers of CD45+, CD3+ and CD163+ cells, regarding both the portal tract and liver lobule, and the severity of steatosis, ballooning and fibrosis (P<0.01). These data suggest that the severity and composition of the inflammatory infiltrate correlate with steatosis and the severity of disease in children with NAFLD. Moreover, a decrease in CD3+ cells may be involved in the pathogenesis of liver damage. Future studies should evaluate whether it can predict the progression of liver disease independently of established histological scores.  相似文献   

15.
The vitamin A metabolite retinoic acid is important for the function of the adaptive immune system, but the mechanism is not completely understood. Here we show that vitamin A is essential for the generation of Notch‐dependent CD8? dendritic cells (DCs) in the spleen. We observed that CD8?CD4? (double negative (DN)) and CD4+ DCs, but not CD8+ DCs, express vitamin A regulated genes. To determine whether vitamin A levels influence splenic DC development, we generated mice that were fed a vitamin A‐deficient diet. We detected a specific reduction of CD4+ and DN DCs in the spleens of mice fed a vitamin A‐deficient diet, while pre‐DC numbers in both spleen and bone marrow were not affected. Vitamin A was specifically necessary for the development of RelBhigh, Notch‐dependent CD4+, and DN DCs. In addition, DN DCs showed reduced proliferation during vitamin A deficiency. In contrast, mice that had received a diet with increased amounts of retinoic acid showed a significant expansion of Notch‐dependent DN DCs. These data demonstrate that vitamin A stimulates the development of Notch‐dependent splenic DCs and indicate that inefficient generation of DCs may contribute to the immune deficits observed during vitamin A deficiency.  相似文献   

16.
《Mucosal immunology》2009,2(2):156-165
Steady-state dendritic cells (DCs) migrating in the lymph from the intestine induce tolerance to harmless intestinal antigens, preventing inflammatory responses. To determine if such DCs are inherently tolerogenic we collected intestinal lymph DCs (L-DCs) by cannulation of the thoracic duct of rats after mesenteric lymphadenectomy, and examined their capacity to activate naive CD4+ lymphocytes in an allogeneic mixed leucocyte reaction. L-DCs stimulated strong proliferative responses, induced secretion of inflammatory cytokines including interferon-γ, and induced FoxP3-positive lymphocytes to divide. To determine if the activated CD4+ T cells had been tolerized, they were rested and restimulated with irradiated splenocytes. The restimulated CD4+ T cells again proliferated and secreted inflammatory cytokines. These data demonstrate that the DCs, which migrate from the intestine in the steady state, are paradoxically able to induce strong inflammatory responses from naive T cells, despite their role in the maintenance of oral tolerance.  相似文献   

17.
Adult human mesenchymal stromal or stem cells (MSC) can differentiate into a variety of cell types and are candidate cellular therapeutics in regenerative medicine. Surprisingly, these cells also display multiple potent immunomodulatory capabilities, including allosuppression, making allogeneic cell therapy a possibility. The exact mechanisms involved in regulatory T cell induction by allogeneic human MSC was examined, using purified CD4+ populations and well‐characterized bone marrow‐derived adult human MSC. Allogeneic MSC were shown to induce forkhead box P3 (FoxP3)+ and CD25+ mRNA and protein expression in CD4+ T cells. This phenomenon required direct contact between MSC and purified T cells, although cell contact was not required for MSC induction of FoxP3 expression in an unseparated mononuclear cell population. In addition, through use of antagonists and neutralizing antibodies, MSC‐derived prostaglandins and transforming growth factor (TGF)‐β1 were shown to have a non‐redundant role in the induction of CD4+CD25+FoxP3+ T cells. Purified CD4+CD25+ T cells induced by MSC co‐culture expressed TGF‐β1 and were able to suppress alloantigen‐driven proliferative responses in mixed lymphocyte reaction. These data clarify the mechanisms of human MSC‐mediated allosuppression, supporting a sequential process of regulatory T cell induction involving direct MSC contact with CD4+ cells followed by both prostaglandin E2 and TGF‐β1 expression. Overall, this study provides a rational basis for ongoing clinical studies involving allogeneic MSC.  相似文献   

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The peripheral chemokine receptors chemokine receptor 3 (CXCR3) and CC chemokine receptor 5 (CCR5) have been reported to be associated with allograft rejection. The impact of the expression of immunosuppressive drugs on peripherally circulating CD4+ T cell subsets after renal transplantion is unknown. Expression of CXCR3 and CCR5 was investigated by flow cytometry in 20 renal allograft recipients participating in a prospective, randomized trial (NCT00514514). Initial immunosuppression consisted of basiliximab, cyclosporin A (CsA), mycophenolate sodium and corticosteroids. After 3 months, patients were treated either with CsA, mycophenolate sodium (MPA) plus corticosteroids (n = 6), CsA and everolimus plus corticosteroids (n = 8) or CsA-free (CsAfree) receiving everolimus, MPA and corticosteroids (n = 6). After initial reduction of CD4+forkhead box protein 3 (FoxP3)+ and CD4+CD25hiFoxP3+ regulatory T cells (Tregs) (P < 0·05; P < 0·01), 3-month post-transplant percentages of Tregs were reconstituted in CsAfree and CsAlo arms compared to CsAreg 12 months post transplant. Expression of CCR5 and CXCR3 on CD4+FoxP3+ and CD4+FoxP3- T cells 12 months post transplant was increased in CsAfreeversus CsAreg. Increase in CCR5+CXCR3+ co-expressing CD4+FoxP3- cells between 3 and 12 months correlated negatively with the glomerular filtration rate (GFR) slope/year [modification of diet in renal disease (MDRD); r = −0·59, P < 0·01]. CsA, but not everolimus, inhibits both Treg development and expression of CXCR3 and CCR5 on CD4+ T cell subsets. Increase in CCR5+CXCR3+ co-expressing CD4+FoxP3- T cells is associated with early loss in allograft function.  相似文献   

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