Interleukin-10 and tumor necrosis factor-alpha single nucleotide gene polymorphism frequency in paracoccidioidomycosis

Allelic variants of cytokine genes seem to be involved in mechanisms of resistance or susceptibility to several diseases. The aim of this study was to investigate the frequency of genotypes with the tumor necrosis factor-alpha TNF-alpha gene polymorphism G/A at position -308 and the IL-10 gene polymorphism G/A at position -1082, and to verify a possible association of these polymorphisms with paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. Genotyping was performed by allele-specific polymerase chain reaction (ASPCR) and restriction fragment length polymorphism (RFLP) on genomic DNA isolated of granulocytes from 54 PCM patients and 31 noninfected individuals. The analysis of SNP at position -1082 IL-10 showed a high frequency of GA genotype in both patients and controls (51% and 55%, respectively), while the allelic frequency showed 54% of G allele in the patients and 66% of A allele in the controls. The GG genotype was more frequent in patients (85%) and controls (68%) when we analyze the SNP at position -308 of TNF-alpha gene. Otherwise, 91% of PCM patients and 84% of noninfected individuals carried the G allele in -308 TNF-alpha SNP. Stimulation of cells from individuals with PCM phenotyped as A+ (GA or AA genotypes) presented elevation of TNF-alpha producing cells when compared with IL-10-producer cells. These findings reinforce the critical role of IL-10 and TNF-alpha in the paracoccidioidomycosis and can strongly suggest that the genetic screening of the -308G/A and -1082G/A polymorphisms may be a valid tool for identification of subjects needing a more appropriate therapy.     

Significant association of a single nucleotide polymorphism in the tumor necrosis factor-alpha (TNF-α) gene promoter with human narcolepsy

Narcolepsy is a sleep disorder in which multiple factors, including environmental and genetic factors, are involved. A genetic factor strongly associated with the disorder has been found in the human leukocyte antigen (HLA) class II region: the haplotype, DRB1*1501-DQB1*0602, predisposes to narcolepsy. No susceptibility genes other than the HLA-haplotype have been found. In this paper, we performed an association study of the tumor necrosis factor-alpha (TNF-alpha) gene located in the HLA class III region with human narcolepsy, in which we examined the known single-nucleotide polymorphisms (SNPs) in the promoter region in 49 narcoleptic patients, who were all positive for DRBI*1501, and 111 healthy control individuals. The results indicated that the frequency of the genotype at position -857 (-857SNP) was significantly different between the patients and controls, and the allele frequencies of 857SNP revealed that the frequency of -857T was significantly increased in the patients as compared with that in the controls (P=0.0068). In addition, haplotypes presumed from HLA-DRB1, -857SNP and HLA-B loci suggested that -857T was mainly associated with DRB1 alleles other than DRB1*1501: the significant increase in frequency of -857T in the patients was not caused by allelic association with DRB1*1501. Therefore, it is conceivable that the TNF-alpha with 857T was associated with narcolepsy independently of the strong association of DRB1*1501 with the disorder. Altogether, the data presented here lead us to propose that TNF-alpha could be a new susceptibility gene in human narcolepsy.     

肿瘤坏死因子-α（TNF-α）在肝再生中的作用

肝脏具有强大的再生能力,多种细胞因子和生长因子参与了肝再生过程的调控。其中肿瘤坏死因子-α（TNF-α）在肝细胞再生中都发挥着不可或缺的作用。本文就TNF-α在启动肝再生、促进或抑制肝细胞凋亡调控机制的研究进展作一综述。     

肿瘤坏死因子 α抑制剂对妊娠的影响

 肿瘤坏死因子 α（TNF-α）是类风湿关节炎（RA）发病和维持关节慢性滑膜炎症反应的最重要的致炎性细胞因子之一，它在 T 细胞依赖的炎症性肠病（IBD）发病机制中也起着十分重要的致炎作用。大量临床研究证实，TNF-α抑制剂（TNFAI）可改善 RA 患者关节功能，减少 RA临床活动性，并延缓关节损坏的进展^[1]。各种 TNFAI 也逐渐用于治疗其他风湿性疾病，如银屑病、幼年特发性关节炎、强直性脊柱炎等。某些 TNFAI 被证明对难治性 IBD 有效。目前经美国 FDA 批准上市的 TNFAI 类药物共有 3 种，它们是依那西普（Etanercept，商品名Enbrel），英利西单抗（Infliximab，商品名 Remicade）和阿达木单抗（Adalimumab，商品名Humira）。依那西普是 II 型TNF受体（TNFR-II）与 IgG1-Fc 的融合蛋白，用药方式为皮下注射。英利西单抗是由人 IgG1-Fc 和鼠 Ig 可变区组成的嵌合体 TNF-α 单抗，阿达木单抗是人源 IgG1 型 TNF-α 单抗，这2 种药物均经静脉注射给药[1]。TNFAI的主要不良反应有注射部位反应、感染、肿瘤、淋巴增殖性疾病、神经脱髓鞘病变以及狼疮样综合征^[1]。由于风湿性疾病多累及生育年龄女性，同时以 TNFAI 为代表的生物制剂应用越来越广泛，TNFAI 对妊娠是否有影响日益受到临床关注。我们复习了2007 年 2 月1日以前 PubMed 中关于上述 3 种 TNFAI对妊娠影响的临床观察文献，现综述如下。......     

Tumor necrosis factor-alpha single nucleotide polymorphisms in juvenile systemic lupus erythematosus

BackgroundJuvenile systemic lupus erythematosus (JSLE) is a multi-system autoimmune disorder of unknown origin. Given the importance of the contribution of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), towards the pathogenesis of JSLE, this study was performed to assess TNFA gene polymorphisms in a case-control study.MethodsFifty nine patients with JSLE were enrolled in this study as case group and compared with healthy control subjects. The frequency of alleles, genotypes, and haplotypes of TNFA single-nucleotide polymorphisms (SNPs) at positions −308 and −238 were evaluated, using polymerase chain reaction with sequence-specific primers method.ResultsThe G allele at position −238 in TNFA promoter region was significantly more frequent in patients with JSLE than in the healthy controls (P value < 0.001), while the frequency of A allele at the same position was significantly lower than controls. Furthermore, a significant positive association for G/G genotype at the same position was detected in patients’ group compared with control subjects (P value < 0.001). The GA haplotype of TNFA (positions −308, −238) was significantly less frequent in case group than in controls (P value < 0.001), while GG was the most frequent haplotype for TNFA in the patient group, compared to controls (P value < 0.01).ConclusionsPro-inflammatory cytokine gene polymorphisms may influence susceptibility to JSLE. Particular TNFA gene variants are associated with JSLE and could be used as a genetic marker for susceptibility to JSLE.     

DNA甲基化、单核苷酸多态性与肿瘤

DNA甲基化是表观遗传修饰的重要部分,基因异常甲基化在肿瘤发生、发展中扮演重要角色.众多研究结果表明单核苷酸多态性(single nucleotide polymorphism,SNP)与DNA甲基化之间存在密切联系,可能通过改变甲基化位点或对DNA甲基化相关酶类产生影响,继而影响到相关基因的甲基化状态,改变表达水平,...     

Increased expression of tumor necrosis factor-alpha in diabetic macrovasculopathy.

Large vessel disease, a common feature of diabetes mellitus, appears to run an aggressive course, but its cellular and molecular aspects remain partially elucidated. Although in common atherosclerosis and especially in other forms of accelerated vasculopathy, immunoinflammatory mechanisms participate in the disease process, it is unclear whether this is present in diabetic vasculopathy. We hypothesized that diabetic macrovasculopathy, compared with classical atherosclerosis, is associated with increased immunoinflammatory features and matrix accumulation. In this study, vessel segments obtained after lower-limb amputation for advanced atherosclerotic disease, from type 2 diabetic patients (n = 20; 68.9+/-10.9 years) and nondiabetic patients (n = 16; 67.1+/-14.6 years) were analyzed. Histological characteristics (extent of intimal proliferation, cellularity, and fibrosis) were semiquantitatively graded in the two lesion types. Using immunohistochemistry, the presence of T cells and macrophages, accumulation of fibronectin, and expression of tumor necrosis factor-alpha was also assessed. Histological features of these advanced atherosclerotic lesions were similar in the two lesions examined. By immunohistochemistry, a similar pattern of T-cell and macrophage infiltration and fibronectin accumulation was observed. Nevertheless, increased expression of tumor necrosis factor-alpha was observed in diabetic lesions (13/19 patients had positive staining), whereas only 2 of 16 lesions from nondiabetic patients had positive staining (p < 0.003), with an odds ratio of 15.17 (confidence interval 2.12-139.5). These data suggest that increased expression of tumor necrosis factor-alpha observed in the diabetic lesions may reflect an enhanced inflammatory activity associated with the development of vascular lesions in type 2 diabetic patients.     

Claudin-1 expression is induced by tumor necrosis factor-alpha in human pancreatic cancer cells

Claudin-1 is a membrane protein with four transmembrane domains, that is exclusively localized at cellular tight junctions. Recent studies have reported that claudin-1 plays an important role in cancer invasion and metastasis. However, the significance of claudin-1 in pancreatic cancer is still unknown. In the present study, we investigated the role of claudin-1 expression in pancreatic cancer growth using the PANC-1 human pancreatic cancer cell line. Treatment with tumor necrosis factor-alpha (TNF-alpha), an inflammatory cytokine, resulted in increased detection of 89 kDa products of poly-(ADP-ribose) polymerase (PARP), a marker of apoptosis, and decreased PANC-1 cell proliferation by 23%. Expression of claudin-1 was up-regulated by TNF-alpha in a concentration-dependent manner in PANC-1 cells. PANC-1 cells treated with TNF-alpha and siRNA against claudin-1 showed a 15% increase in proliferation; i.e. the cells transfected with siRNA against claudin-1 showed resistance to TNF-alpha-induced apoptosis. These results suggest that claudin-1 expression is responsible for TNF-alpha-dependent growth signals and the proliferation of pancreatic cancer cells.     

Effect of retinoids on the release and gene expression of tumor necrosis factor-alpha in human peripheral blood monocytes

The effect of retinoic acid (RA) and retinol (ROH) on the release of tumor necrosis factor (TNF) by human peripheral blood monocytes (HPBM) was determined. HPBM were cultured for various periods of time in either 5% complete (cAB) or delipidized (DLS) AB serum. TNF release (L929 cytolytic assay) in the presence of cAB occurred during the first 3 days of in vitro culture. Delipidization of AB serum completely inhibited the lipopolysaccharide (LPS)-induced release of TNF by HPBM. Addition of RA (0.5 microM) to DLS restored LPS-induced TNF release by HPBM, and supplementation with ROH (1.0 microM) resulted in release of TNF-like activity, but only after 3 days of in vitro culture. The maintenance of TNF release by the addition of exogenous RA after 3 days of in vitro culture suggested that depletion of endogenous RA was partially responsible for loss of TNF-like activity. The levels of endogenous TNF protein and mRNA were not influenced by delipidization of serum and were found to be similar to those of HPBM cultured in the presence of AB serum. TNF protein and mRNA were undetectable in HPBM ROH-treated cell lysates, although cytolytic activity was observed in culture supernatants. These results suggest that retinoids are required for the release of cytolytic factors from HPBM and that non-TNF cytolytic factors may be released by these cells at different stages of maturation.     

Tumor necrosis factor-alpha gene expression in human whole blood

Tumor necrosis factor-alpha (TNF) is recognized as a principal mediator of a variety of pathophysiologic and immunologic events. Lipopolysaccharide (LPS) challenge, either in vitro or in vivo, results in significant TNF production. In this study we present data demonstrating LPS-induced TNF mRNA expression and bioactivity using an in vitro tissue system of whole blood (WB). The kinetics of LPS-induced TNF production by WB was significantly accelerated as compared to isolated cultured peripheral blood monocytes (PBM). At post-LPS challenge, plasma from WB demonstrated a rapid rise in TNF bioactivity, peaking by 4 hr (1,021 units/ml/10(6) cells), plateauing between 4 and 8 hr, and then decreasing over the next 16 hr. In contrast, the highest measured TNF bioactivity from PBM did not occur until the 24-hr time-point (175 units/ml/10(6) cells). Whole blood buffy-coat TNF mRNA was assessed by Northern blot analysis, and demonstrated significant TNF mRNA accumulation at 1 hr and a peak 2 hr post-LPS challenge. By 8 hr TNF mRNA was undetectable. Concomitant administration of LPS with either prostaglandin E2 (10(-6)M) or Dexamethasone (10(-6)M) resulted in significant suppression of LPS-induced TNF production. This data supports WB as a useful in vitro medium for the molecular and cellular analysis of TNF. As specialized connective tissue, WB may provide an important environment to study the pharmacologic manipulation of TNF mRNA and bioactivity.     

Human hemoglobin shares bioactivities ascribed to human tumor necrosis factor-alpha

Hemoglobin mediated cytotoxicity and apoptosis has been evaluated in Tumor necrosis factor-alpha (TNF-alpha) sensitive cell line, U937 and compared with TNF-alpha. Both species of hemoglobin, Hemoglobin A2 and Hemoglobin A0 induced apoptosis and cytotoxicity in U937 cell as measured by flow cytometry and 3-(4,5-dihydro-6-(4-(3,4-dimethoxybenzooyl)-1-piperazinyl)-2(1H)-quinoline (MTT) assay respectively. Different concentration of Hemoglobin A0 (4 ng/mL to 4000 ng/mL) induced apoptosis ranging from 9% to 16% in U937 cells. 4000 ng/mL hemoglobin A0 showed maximal apoptotic cells. TNF-alpha showed 87% apoptotic U937 cells at concentration of 1 pg/mL. HbA0 displayed cytotoxicity in U937 cell line at higher concentration in comparison to TNF-alpha. 4000 ng/mL of hemoglobin A0 showed optimal cytotoxic response in U937 cells. A dose response curve was also observed with varying doses of hemoglobin A0. U937 cells pretreated with serum activated LPS for 1 hr and incubated with different concentration of hemoglobin or human TNF-alpha for 24 h reduced the cytotoxic effect on U937. Dexamethasone treatment of U937 cells helped in protecting the HbA0 and HbA2 mediated cytotoxicity and anti-TNF-alpha antibody neutralized the hemoglobin mediated apoptosis and cytotoxicity. It is therefore apparent that human hemoglobin shares some of the bioactivities previously ascribed to TNF-alpha. Sharing of bioactivities of TNF-alpha by hemoglobin is interesting and suggests that cell free hemoglobin can mimic TNF-alpha functionally.     

Cytotoxicity of tumor necrosis factor-alpha for human umbilical vein endothelial cells

Human umbilical vein endothelial cells were examined for sensitivity to killing by human recombinant tumor necrosis factor-alpha (TNF-alpha). Treatment of the cells with concentrations of TNF-alpha up to 50 ng/ml for 18 hours did not produce evidence of cytotoxicity. However, a marked cytotoxic effect was found when TNF-alpha pretreated cells were incubated in Hanks' balanced salt solution for a further 4 hours. Exposure of the cells to heat-inactivated or antibody-neutralized TNF-alpha did not result in cytotoxicity. Human recombinant interleukin-1 also lysed endothelial cells under the same conditions, whereas human recombinant macrophage-colony stimulating factor did not. Inclusion of superoxide dismutase, catalase, or soybean trypsin inhibitor in the culture medium during the time of endothelial cell exposure to TNF-alpha had no protective effects. Likewise, allopurinol (a xanthine oxidase inhibitor) and nordihydro-guaiaretic acid (a lipoxygenase inhibitor) were not protective under the same conditions. In contrast, the ferric iron chelator deferoxamine mesylate and three different cyclooxygenase inhibitors provided significant protection against TNF-alpha induced cytotoxicity. When human dermal fibroblasts and human squamous epithelial cells were used in place of the umbilical vein endothelial cells, these cells were resistant to TNF-alpha mediated killing. These findings demonstrate that under the experimental conditions employed, TNF-alpha is cytotoxic for human umbilical vein endothelial cells. This may have implications in a number of in vivo situations in which TNF-alpha is thought to play a role.     

Liposome-encapsulated tumor necrosis factor-alpha enhances the effects of radiation against human colon tumor xenografts.

Recent reports have shown that tumor necrosis factor-alpha (TNF-alpha) can augment the effects of radiation against certain tumor types. However, the high concentrations of intravenous infusion of TNF-alpha needed to cause tumor regression can induce many systemic side effects. The aims of this study were to determine if TNF-alpha encapsulated in sterically stabilized (Stealth, ALZA Corporation, Mountain View, CA), PEGylated liposomes (SL) augments the antitumor effects of radiation and to compare its efficacy and possible toxicity with free TNF-alpha in the LS174T human colon tumor xenograft model. Nude mice were injected subcutaneously (s.c.) with LS174T cells and treated intravenously (i.v.) with Stealth-liposomal TNF-alpha (SL-TNF-alpha) with and without radiation or TNF-alpha with or without radiation when tumor size was approximately 200 mm(3). In phase 1, a significant decrease (p = 0.047) in tumor growth was observed with radiation at day 21 but not with SL-TNF-alpha or free TNF-alpha alone. By the end of phase 1 (day 27) with continued treatments, the SL-TNF-alpha plus radiation group had significantly smaller tumors (p = 0.044) than those in the free TNF-alpha plus radiation group. In phase 2, where a similar tumor growth reduction pattern was observed, the addition of TNF-alpha to radiation, either as free protein or within SL, increased lymphocyte activation and natural killer (NK) cell numbers in both blood and spleen. The effect was generally more pronounced with SL-TNF-alpha. Systemic toxicity, based on hematologic analyses and body weight, was absent or minimal. Collectively, the data show that pretreatment with SL-TNF-alpha can enhance more effectively, and possibly more safely, the effects of radiation against human colon tumor xenografts than can free TNF-alpha and that the increased antitumor action may involve upregulation of lymphocytes.     

Modulation of human peripheral blood eosinophil function by tumor necrosis factor-alpha

Eosinophils are important effectors in helminthic parasitic infection. Tumor necrosis factor (TNF-alpha) has been implicated as a mediator in the host response to parasitic infection and enhances eosinophil-mediated helminthotoxicity. We have examined the direct effects of recombinant human (rh) TNF on eosinophil functions of degranulation and oxidative metabolism. This report describes the minimal effects of rhTNF-alpha on eosinophil superoxide anion generation and enzyme secretion, which do not satisfactorily explain the observed increases in helminthotoxicity. In contrast to other cell types, eosinophils are unique in their differential responses to interleukin-1 beta and TNF.     

Interleukin-4 differentially regulates tumor necrosis factor-alpha gene expression by human T lymphocytes and monocytes.

Tumor necrosis factor-alpha (TNF-alpha), a product of both mononuclear phagocytes and T lymphocytes, is an important proximal mediator of a number of acute and chronic inflammatory disease states. In this investigation we examine the regulatory effects of the lymphocyte product interleukin-4 (IL-4) on the gene expression of TNF-alpha from stimulated human peripheral blood monocytes (PBM) and T lymphocytes. We demonstrated the dose-dependent suppression of TNF-alpha mRNA and protein synthesis from lipopolysaccharide-treated PBM by IL-4. The suppressive effects of IL-4 appear to be dependent upon de novo protein synthesis, as cycloheximide abrogated the IL-4-induced reduction in TNF-alpha mRNA levels from PBM. In contrast to the suppressive effects of IL-4 on PBM-derived cytokine expression, IL-4 did not alter TNF-alpha mRNA expression from alpha-Cd3 or PMA + alpha-CD-28-treated T lymphocytes. Moreover, IL-2 mRNA expression from similarly treated T lymphocytes was unaltered by IL-4. Our findings demonstrate that disparity exists in the regulation of TNF-alpha gene expression from different immune cell populations which may have important implications in the evolution of acute and chronic inflammatory responses.     

Linkage of human tumor necrosis factor-alpha to human osteoporosis by sib pair analysis

Osteoporosis as well as osteopenia are common human conditions considered to result from the interplay of multiple genetic and environmental factors. Twin and family studies have yielded strong correlation between measures of bone mass and a number of genetic factors. Certain genes (e.g., cytokines such as interleukin-1, interleukin-6, or tumor necrosis factor-alpha) are capable of regulating metabolism, formation, and resorption of bone; all processes that determine bone mass. We tested 192 sib-pairs of adult Japanese women from 136 families for genetic linkage between osteoporosis and osteopenia phenotypes and allelic variants at the tumor necrosis factor-alpha (TNFA) locus, using a dinucleotide-repeat polymorphism located near the gene. The TNFA locus showed evidence for linkage to osteoporosis, with mean allele sharing of 0.478 (P = 0.30) in discordant pairs and 0.637 (P = 0.001) in concordant affected pairs. Linkage with osteopenia was also significant in concordant affected pairs (P = 0.017). Analyses limited to the post-menopausal women in our cohort showed similar or even stronger linkage for both phenotypes. The results provide evidence that genetic variations within the TNFA locus or adjacent genes affect regulation of mineral metabolism in bone and some of them confer risk for osteoporosis in adult women.