• Title/Summary/Keyword: TNF-a gene

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Tumor Necrosis Factor Alpha -308 G/A Single Nucleotide Polymorphism and Susceptibility to Hepatocellular Carcinoma Via Hepatitis B Infection

  • Azar, Saleh Shahbazi;Mansoori, Maryam;Attar, Marzieh;Shahbazi, Majid
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3381-3384
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    • 2016
  • Background: Hepatitis B virus (HBV) is a key factor for hepatocellular carcinoma (HCC). About 350 million people are affected by chronic infection which is related to the rapid development of liver diseases as well as hepatitis, cirrhosis and hepatocellular carcinoma. Expression of tumor necrosis factor alpha (TNF-${\alpha}$) in the liver demonstrates a major genetic polymorphism which is involved in resistance or susceptibility to chronic HBV infection. Materials and Methods: In this study, two populations were studied by the sequence specific primer-polymerase chain reaction (SSP-PCR) method: HBV cases (n=409), who were HBS-Ag+, and healthy controls (n=483). Results: The results shown that the frequency of TNF-${\alpha}$ -308 G/G genotype in healthy controls (47.2%) was significantly higher than in HBV infected patients (28%) (CI = 1.29-2.61, OR = 1.83, P = 0.0004). Also TNF-${\alpha}$ -308 A/A and A/G genotype frequencies in the healthy controls were 4.6% and 48.2% and in patient group were 19.5% and 52.5% (CI = 2.23-7.12, p: 0.0001, OR: 3.94) respectively. Conclusions: We found that among Iranian people TNF-${\alpha}$ -308A allele not only has the highest genotype frequency but also it has the highest frequency in the world population. In addition, TNF-${\alpha}$-308 G/G polymorphism was associated with HBV resistance, whereas TNF-${\alpha}$-308A (A/A or A/G) polymorphism appeared to associated with chronic HBV infection. These data suggested that among the Iranian population, the -308 G/G polymorphism of TNF-${\alpha}$ gene promoter region has the potential to influence the susceptibility to HBV infection and it may be responsible for viral antigen clearance.

The Regulation of Chemerin and CMKLR1 Genes Expression by TNF-α, Adiponectin, and Chemerin Analog in Bovine Differentiated Adipocytes

  • Suzuki, Y.;Hong, Y.H.;Song, S.H.;Ardiyanti, A.;Kato, D.;So, K.H.;Katoh, K.;Roh, Sang-Gun
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.9
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    • pp.1316-1321
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    • 2012
  • Adipokines, adipocyte-derived protein, have important roles in various kinds of physiology including energy homeostasis. Chemerin, one of adipocyte-derived adipokines, is highly expressed in differentiated adipocytes and is known to induce macrophage chemotaxis and glucose intolerance. The objective of the present study was to investigate the changes of chemerin and the chemokine-like-receptor 1 (CMKLR1) gene expression levels during differentiation of the bovine adipocyte and in differentiated adipocytes treated with tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), adiponectin, leptin, and chemerin (peptide analog). The expression levels of the chemerin gene increased at d 6 and 12 of the differentiation period accompanied by increased cytoplasm lipid droplets. From d 6 onward, peroxisome proliferator-activated receptor-${\gamma}2$ (PPAR-${\gamma}2$) gene expression levels were significantly higher than that of d 0 and 3. In contrast, CMKLR1 expression levels decreased at the end of the differentiation period. In fully differentiated adipocytes (i.e. at d 12), the treatment of TNF-${\alpha}$ and adiponectin upregulated both chemerin and CMKLR1 gene expression levels, although leptin did not show such effects. Moreover, chemerin analog treatment was shown to upregulate chemerin gene expression levels regardless of doses. These results suggest that the expression of chemerin in bovine adipocyte might be regulated by chemerin itself and other adipokines, which indicates its possible role in modulating the adipokine secretions in adipose tissues.

Down-regulation of inducible nitric oxide synthase and tumor necrosis factor-a expression by Bisphenol A via nuclear factor-kB inactivation in macrophages

  • Kim, Ji-Young;Jeong, Hye-Gwang
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.293.2-293.2
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    • 2002
  • Bisphenol A [BPA. 2.2-bis(4-hydroxyphenyl)propane] is reported to have estrogenic activity: however. its influence on cytokine production or immune system function remains unclear. In this study. we investigated the effects of BPA on the production of nitric oxide (NO) and tumor necrosis factor-a (TNF-a), and on the level of inducible nitric oxide synthase (iNOS) and TNF-a gene expression in mouse macrophages. BPA alone did not affect NO or TNF-a production. (omitted)

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Altered Gene Expression of Inflammatory Cytokines in Adipose Tissue of Streptozotocin-induced Diabetic C57BL/6 Mice (Streptozotocin으로 당뇨가 유도된 C57BL/6 생쥐 지방조직에서의 염증성 사이토카인 유전자의 이상발현)

  • Lee, Yong-Ho;Kim, Jong Bong
    • Journal of Life Science
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    • v.23 no.6
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    • pp.825-831
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    • 2013
  • The aim of this study was to investigate the effects of induced diabetes by streptozotocin (STZ) administration on gene expression of proinflammatory cytokines in adipose tissue of C57/BL6 mice fed either a normal diet (ND) or a high-fat diet (HFD). Four diabetic mice groups (16- or 26-week-old mice fed either ND or HFD) and four control groups of age and diet matched non-diabetic mice were used. By real-time PCR, gene expression levels of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and monocyte chemoattractant protein-1 (MCP-1) were examined in adipose tissue. The results demonstrated that gene expression of TNF-${\alpha}$ was significantly or marginally increased in STZ induced diabetic mice groups compared with non-diabetic groups. On the other hand, MCP-1 gene expression tended to be decreased in diabetic mice compared with non-diabetic controls. Especially, MCP-1 expression level in 16w diabetic mice on HFD was about 26% of that in age and diet matched non-diabetic controls (p<0.001). In addition, MCP-1 gene expression in adipose tissue was correlated with plasma insulin levels (p=0.0002). These results suggest that gene expression of proinflammatory cytokines in adipose tissue is differentially regulated in mouse models of diabetes. The basic data in this study will be useful for elucidating basic mechanisms of inflammatory state and increased expression of proinflammatory cytokines in adipose tissue in obesity, insulin resistance, and diabetes.

TNFα-induced Down-Regulation of Estrogen Receptor α in MCF-7 Breast Cancer Cells

  • Lee, Sang-Han;Nam, Hae-Seon
    • Molecules and Cells
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    • v.26 no.3
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    • pp.285-290
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    • 2008
  • Estrogen-induced proliferation in estrogen receptor (ER)-positive breast cancer cells is primarily mediated through two distinct intracellular receptors, $ER{\alpha}$ and $ER{\beta}$. Although tumor necrosis factor alpha ($TNF{\alpha}$) and $E2/ER{\alpha}$ are known to exert opposing effects on cell proliferation in MCF-7 cells, the mechanism by which $TNF{\alpha}$ antagonizes $E2/ER{\alpha}$-mediated cell proliferation is not well understood. The present study suggests that reduced cell survival in response to $TNF{\alpha}$ treatment in MCF-7 cells may be associated with the down-regulation of $ER{\alpha}$ protein. The decrease in $ER{\alpha}$ protein level was accompanied by an inhibition of $ER{\alpha}$ gene transcription. Cell viability was decreased synergistically by the combined treatment with $ER{\alpha}$-siRNA and $TNF{\alpha}$. Furthermore, pretreatment of cells with the PI3-kinase (PI3K)/ Akt inhibitor, LY294002, markedly enhanced $TNF{\alpha}$-induced down-regulation of the $ER{\alpha}$ protein, suggesting that the PI3K/Akt pathway might be involved in control of the $ER{\alpha}$ level. Moreover, down-regulation of $ER{\alpha}$ by $TNF{\alpha}$ was not inhibited in cells that were pretreated with the proteasome inhibitors, MG132 and MG152, which suggests that proteasome-dependent proteolysis does not significantly influence $TNF{\alpha}$-induced down-regulation of $ER{\alpha}$ protein. In contrast, the effect of the PI3K/Akt inhibitor on $ER{\alpha}$ was blocked in cells that were treated with LY294002 in the presence of the proteasome inhibitors. Collectively, our findings show that the $TNF{\alpha}$ may partly regulate the growth of MCF-7 breast cancer cells through the down-regulation of $ER{\alpha}$ expression, which is primarily mediated by a PI3K/Akt signaling.

Potentiation of Innate Immunity by β-Glucans

  • Seong, Su-Kyoung;Kim, Ha-Won
    • Mycobiology
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    • v.38 no.2
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    • pp.144-148
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    • 2010
  • $\beta$-Glucans have been known to exhibit antitumor activities by potentiating host immunity by an unknown mechanism. The C-type lectin dectin-1, a $\beta$-glucan receptor, is found on the macrophage and can recognize various $\beta$-glucans. Previously, we demonstrated the presence of $\beta$-glucan receptor, dectin-1, on the Raw 264.7 cells as well as on murine mucosal organs, such as the thymus, the lung, and the spleen. In order to investigate immunopotentiation of innate immunity by $\beta$-glucan, we stimulated a murine macrophage Raw 264.7 cell line with $\beta$-glucans from Pleurotus ostreatus, Saccharomyces cerevisiae, and Laminaria digitata. Then, we analyzed cytokines such as tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-6 by reverse transcription-polymerase chain reaction (RT-PCR). In addition we analyzed gene expression patterns in $\beta$-glucan-treated Raw 264.7 cells by applying total mRNA to cDNA microarray to investigate the expression of 7,000 known genes. When stimulated with $\beta$-glucans, the macrophage cells increased TNF-$\alpha$ expression. When co-stimulation of the cells with $\beta$-glucan and lipopolysaccharide (LPS), a synergy effect was observed by increased TNF-$\alpha$ expression. In IL-6 expression, any of the $\beta$-glucans tested could not induce IL-6 expression by itself. However, when co-stimulation occurred with $\beta$-glucan and LPS, the cells showed strong synergistic effects by increased IL-6 expression. Chip analysis showed that $\beta$-glucan of P. ostreatus increased gene expressions of immunomodulating gene families such as kinases, lectin associated genes and TNF-related genes in the macrophage cell line. Induction of TNF receptor expression by FACS analysis was synergized only when co-stimulated with $\beta$-glucan and LPS, not with $\beta$-glucan alone. From these data, $\beta$-glucan increased expressions of immunomodulating genes and showed synergistic effect with LPS.

Hepatitis C Virus Nonstructural 5A Protein (HCV-NS5A) Inhibits Hepatocyte Apoptosis through the NF-κb/miR-503/bcl-2 Pathway

  • Xie, Zhengyuan;Xiao, Zhihua;Wang, Fenfen
    • Molecules and Cells
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    • v.40 no.3
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    • pp.202-210
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    • 2017
  • The nonstructural protein 5A (NS5A) encoded by the human hepatitis C virus (HCV) RNA genome is a multifunctional phosphoprotein. To analyse the influence of NS5A on apoptosis, we established an Hep-NS5A cell line (HepG2 cells that stably express NS5A) and induced apoptosis using tumour necrosis factor $(TNF)-{\alpha}$. We utilised the MTT assay to detect cell viability, real-time quantitative polymerase chain reaction and Western blot to analyse gene and protein expression, and a luciferase reporter gene experiment to investigate the targeted regulatory relationship. Chromatin immunoprecipitation was used to identify the combination of $NF-{\kappa}B$ and miR-503. We found that overexpression of NS5A inhibited $TNF-{\alpha}$-induced hepatocellular apoptosis via regulating miR-503 expression. The cell viability of the $TNF-{\alpha}$ induced Hep-mock cells was significantly less than the viability of the $TNF-{\alpha}$ induced Hep-NS5A cells, which demonstrates that NS5A inhibited $TNF-{\alpha}$-induced HepG2 cell apoptosis. Under $TNF-{\alpha}$ treatment, miR-503 expression was decreased and cell viability and B-cell lymphoma 2 (bcl-2) expression were increased in the Hep-NS5A cells. Moreover, the luciferase reporter gene experiment verified that bcl-2 was a direct target of miR-503, NS5A inhibited $TNF{\alpha}$-induced $NF-{\kappa}B$ activation and $NF-{\kappa}B$ regulated miR-503 transcription by combining with the miR-503 promoter. After the Hep-NS5A cells were transfected with miR-503 mimics, the data indicated that the mimics could reverse $TNF-{\alpha}$-induced cell apoptosis and blc-2 expression. Collectively, our findings suggest a possible molecular mechanism that may contribute to HCV treatment in which NS5A inhibits $NF-{\kappa}B$ activation to decrease miR-503 expression and increase bcl-2 expression, which leads to a decrease in hepatocellular apoptosis.

Inhibitory effects of flavonoids on TNF-α-induced IL-8 gene expression in HEK 293 cells

  • Lee, Soo-Hyoung;Kim, Young-Jin;Kwon, Sang-Hoon;Lee, Young-Hee;Choi, Soo-Young;Park, Jin-Seu;Kwon, Hyung-Joo
    • BMB Reports
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    • v.42 no.5
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    • pp.265-270
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    • 2009
  • Due to their multiple biological activities, flavonoids have gained attention as potentially useful therapeutics for a variety of diseases including cancer, cardiovascular diseases, and autoimmune diseases. In this study, we demonstrated that several flavonoids, including kaempferol, quercetin, fisetin, and chrysin block TNF-$\alpha$ induced IL-8 promoter activation and gene expression in HEK 293 cells. In addition, phosphorylation and degradation of $I{\kappa}B{\alpha}$ and translocation of NF-${\kappa}B$ p65 were inhibited by these flavonoids in TNF-$\alpha$-stimulated HEK 293 cells. Furthermore, generation of reactive oxygen species (ROS) in response to TNF-$\alpha$ was reduced by the flavonoids. Moreover, although pretreatment with fisetin, quercetin, or chrysin decreased cell viability, kaempferol did not. Taken together, these findings suggest that kaempferol would be useful for the treatment of TNF-$\alpha$-induced inflammatory diseases.

Polymorphisms in the TNF-α Gene and Extended HLA and TNF-α Haplotypes in Koreans (한국인에서의 TNF-α 유전자 다형성과 HLA/TNF-α 일배체형의 분포)

  • Park, Yoon June;Park, Hye Jin;Park, Myoung Hee
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.242-247
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    • 2002
  • Background: Tumor necrosis factor-alpha (TNF-$\alpha$) is known to play an important role in various conditions such as inflammation, autoimmunity, apoptosis, insulin resistance and sleep induction. Five single nucleotide polymorphisms (SNPs) have been known to affect the transcriptional activities of TNF-$\alpha$: -1,031T/C, -863C/A, -857C/T, -308G/A and -238G/A. Methods: We have investigated 5 SNPs of the promoter region of TNF-$\alpha$ gene, the distribution of 5-locus TNF-$\alpha$ haplotypes, and their haplotypic associations with previously typed HLA-A, -B and -DRB1 loci in 107 healthy unrelated Koreans. TNF-$\alpha$ SNPs were typed using PCR-single-strand conformation polymorphism (SSCP) and PCR-restriction fragment length polymorphism (RFLP) methods. Results: The allele frequencies of -1,031C, -863A, -857T, -308A, and-238A, which are known as the high-producer-type, were 19.3%, 15.9%, 14.0%, 5.9%, and 2.9%, respectively. The frequency of -308A allele, known to be associated with autoimmune diseases, was 5.9% in Koreans which was lower than Caucasians (14~17%) and somewhat higher than Japanese (1.7%). Five most common TNF-$\alpha$ haplotypes (-1,031/-863/-857/-308/-238) comprised over 95% of total haplotypes: TCCGG (58.4%), CACGG (14.8%), TCTGG (13.7%), TCCAG (5.3%), and CCCGA (3.1%). Strong positive associations (P<0.001) were observed between TCCGG and B62; between CACGG and B51, $DRB1^*0901$; between TCTGG and B35, B54, B59, $DRB1^*1201$; and between TCCAG and A33, B58, $DRB1^*0301$, $DRB1^*1302$. Five most common extended haplotypes (>3%) comprised around 16% of total haplotypes: A33-B58-TCCAG-$DRB1^*1302$, A24-B52-TCCGG-$DRB1^*1502$, A33-B44-TCCGG-$DRB1^*1302$, A24-B7-TCCGG-$DRB1^*0101$, and A11-B62-TCCGG-$DRB1^*0406$. The distribution of extended HLA and TNF-$\alpha$ haplotypes showed that most of HLA haplotypes were almost exclusively associated with particular TNF-$\alpha$ haplotypes. Conclusion: The results obtained in this study would be useful as basic data for anthropologic studies and disease association studies in Koreans.

The Effect of Tumor Necrosis Factor-Alpha on Glomerular Epithelial Cells in Glomerular Permeability ($TNF-{\alpha}$가 토리 상피세포의 투과성에 미치는 영향)

  • Cho Min-Hyun;Lee Ji-Hye;Koo Ja-Hoon;Ko Cheol-Woo
    • Childhood Kidney Diseases
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    • v.8 no.1
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    • pp.1-9
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    • 2004
  • Purpose : Minimal Change Disease (MCD) is the most common primary nephrotic syndrome in children. Some suggested that tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) are involved in the pathogenesis of MCD. Methods : This study was done to see the changes of plasma and urinary $TNF-{\alpha}$, and its effect on the determination of permeability of the glomerular basement membrane (BM) contributed by heparan sulfate proteoglycan (HSPG). Study patients consisted of 19 biopsy-proven MCD children aged 2-15 years old. Both plasma and urinary $TNF-{\alpha}$ were measured. Employing the Millicell system, $TNF-{\alpha}$ was screened for the permeability factors. We examined whether $TNF-{\alpha}$ regulated BM HSPG gene expression and HS synthesis in the glomerular epithelial cells (GECs). Results : Urinary $TNF-{\alpha}$ during relapse was significantly increased when compared with that of during remission or controls ($364.4{\pm}51.2$ vs $155.3{\pm}20.8,\;36.0{\pm}4.5$ ng/mg cr) (P<0.05). However, negative results were obtained in the permeability assay using the Millicell system. No difference was seen in the BM HSPG gene expression and HS synthesis in the GECs. Conclusion : It seems that $TNF-{\alpha}$ may not play a disease-specific role in the pathogenesis of MCD.

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