• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1207-1213
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• 2006

Tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ has been implicated in skeletal diseases by promoting bone loss in inflammatory bone diseases. In the present study, we examined the effects of $TNF-{\alpha}$ on osteoblastic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). $TNF-{\alpha}$ dose-dependently promoted matrix mineralization of hBMSCs with a maximal stimulation at 2ng/ml. $TNF-{\alpha}$ increased expression of alkaline phosphatase, which plays a crucial role for the matrix deposition. The $TNF-{\alpha}-stimulated$ osteoblastic differentiation was not affected by $NF_kB$ inhibitors, BAY and SN50. However, a JNK-specific inhibitor, SP600125 completely abolished the $TNF-{\alpha}-stimulated$ matrix mineralization and expression of alkaline phosphatase. These results suggest that $TNF-{\alpha}$ enhances osteoblastic differentiation of hBMSCs through JNK-dependent pathway.

• Clinical and Experimental Pediatrics
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• v.45 no.2
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• pp.240-246
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• 2002

Purpose : It is not clear that the development of glomerular injury and aggravation by tumor necrosis factor alpha($TNF-{\alpha}$) is related to intrarenal or serum concentration of $TNF-{\alpha}$. So, we studied the relationship between the concentration of $TNF-{\alpha}$ and aggravation of glomerular damage in the Henoch-$Sch{\ddot{o}}nlein$ nephritis(HSN) and idiopathic nephrotic syndrome(INS). Methods : We collected the sera and urines of 21 patients with Henoch-$Sch{\ddot{o}}nlein$ purpura(HSP) and 22 patients with INS visited Chungbuk National University hospital from March 1998 to March 2001. The concentration of $TNF-{\alpha}$ in the sera and urines were measured by sandwich ELISA. Results : Serum $TNF-{\alpha}$ levels in the HSP patients with renal involvement were significantly higher than those without renal involvement(P=0.009). But urine $TNF-{\alpha}$ levels have no correlation with renal involvement(P=0.088). In the HSN patients, proteinuria have a significant correlation with serum $TNF-{\alpha}$ levels(P=0.004) but less correlation with urine $TNF-{\alpha}$ levels(P=0.053). Otherwise, proteinuria have no correlation with serum $TNF-{\alpha}$ levels(P=0.763) but have a significant correlation with urine $TNF-{\alpha}$ levels(P=0.007) in INS. Conclusion : These result suggest that the serum concentration of $TNF-{\alpha}$ would be important to glomerular involvement in HSP. And, it is interesting that proteinuria shows a significant relation with serum $TNF-{\alpha}$ levels in the HSN, but with urine $TNF-{\alpha}$ levels in the INS. This means the major production of $TNF-{\alpha}$ may be originated by extrarenal inflammation in the HSN and by intrarenal tubulo-interstitial damage due to proteinuria in the INS.

• Biomedical Science Letters
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• v.24 no.3
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• pp.213-220
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• 2018

Triglyceride (TG) is known to be associated with inflammatory disease including atherosclerosis. In a variety of atherosclerosis models, T lymphocytes are localized in the earliest lesions of atherosclerosis. T cell associated cytokines such as $TNF-{\alpha}$ and $IFN-{\gamma}$ have pre-dominant inflammatory effects in chronic vascular diseases. In our previous study, we found that the expression of $TNF-{\alpha}$ and its receptor, $TNF-{\alpha}R$ was increased when Jurkat T lymphocyte cell lines were exposed to TGs. Therefore, experiments were conducted to determine which cell signaling pathway are involved in the increase of $TNF-{\alpha}$ and $TNF-{\alpha}R$ expression by TGs. To identify signal transduction pathways involved in TG-induced upregulation of $TNF-{\alpha}$, we treated TG-exposed Jurkat T cells with specific inhibitors for MEK1, PI3K, $NF-{\kappa}B$ and PKC. We found that inhibition of the MEK1 pathway blocked TG-induced upregulation of $TNF-{\alpha}$. However, the expression level of $TNF-{\alpha}R$ did not change with any signal transduction inhibitor. Based on this observation, we suggest that increase of exogenous TG induces increase of $TNF-{\alpha}$ expression through MEK1 pathway in Jurkat T cells. In addition, it was confirmed that the increase of $TNF-{\alpha}$ and $TNF-{\alpha}R$ expression by TGs occurs via different pathways.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.321-326
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• 2016

The aim of this study was to evaluate the association between TNF polymorphism and generalized aggressive periodontitis (GAP) in Korean subjects. The study population consisted of 60 subjects with GAP and 81 reference group. Genomic DNA was extracted from the buccal swabs and the polymorphisms of $TNF-{\alpha}-308$, -238 promoter genes, $TNF-{\beta}+252$ and TNFR 2+587 were determined by PCR-RFLP using restriction enzymes. The genotype distribution in the GAP were 3.2%, 38.7%, and 82.35% for A/A, A/G and G/G genotypes of $TNF-{\alpha}-308$. At the position of $TNF-{\alpha}-238$, the genotype distribution in the GAP were 25.5% and 74.5% for A/G and G/G genotypes. Allele A frequency of $TNF-{\alpha}-238$ were 67.6% in GAP and 72.2% in reference group. According to these findings, the polymorphism at $TNF-{\alpha}-308$ and -238 may be associated with GAP in Korean.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.225-231
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• 1998

Purpose : To determine whether TNF-$\alpha$ increases the antitumor effect of radiotherapy in murine syngeneic tumor system. Materials and Methods : Syngeneic murine tumors of MCa-K or MCa-4 (mammary carcinoma), OCa-I (ovarian carcinoma), or HCa-I(hepatocarcinoma were grown in hind legs of C3Hf/HeJ mice. When tumors were grown to 6 mm in mean diameter mice were treated with TNF-$\alpha$, radiation, or combination of the both. Gamma-radiation was given as a single dose of 30 Gy for HCa-I and 15 Gy for other tumors using Cobalt-60 teletherapy unit. A novel TNF-$\alpha$ mutein developed in Korea, was intraperitoneally administered daily at a dose of 10 ug per mouse for 7 days. In combination of radiation and TNF-$\alpha$, the drug was started 1 hour after radiation. Tumor growth delay assay was used to measure the tumor response to the treatment. Results : Among 4 tested tumors, TNF-$\alpha$ alone showed significant antitumor activity in MCa-K and OCa-I tumors, which showed absolute growth delay (AGD) of 5.0 days and 6.5 days, respectively. In combination with radiation, TNF-$\alpha$ showed significant delay of AGD (41.1 days) in OCA-I compared to AGDs of TNF-$\alpha$ alone and radiation, i.e., 6.5 days and 26.9 days, respectively(p<0.05). Enhancement factor was 1.29 in OCa-I, which showed supraadditive effect. TNF-$\alpha$ did not show significant delay of AGDs in the remaining 3 tumors compared to AGDs of TNF-$\alpha$ alone and radiation. Conclusions: TNF-$\alpha$ alone showed antitumor effects in MCa-K and OCa-I. In combination with radiation, TNF-$\alpha$ acted in supraadditive way in OCa-I only. The results of this study imply that the combination of TNF-$\alpha$ and radiation has different therapeutic potential depending on tumor model and further study is advocated.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.209-219
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• 1997

Previous studies have demonstrated that oxidative stress involving generation of reactive oxygen species (ROS) is responsible for the cytotoxic action of $TNF{\alpha}$. Protective effect of small heat shock proteins (small HSP) against diverse oxidative stress conditions has been suggeted. Although overexpression of small hsp was shown to provide an enhanced survival of $TNF{\alpha}$-sensitive cells when challenged with $TNF{\alpha}$, neither the nature of $TNF{\alpha}$-induced cytotoxicity nor the protective mechanism of small HSP has not been completely understood. In this study, we have attempted to determine whether $TNF{\alpha}$ induces oxidative DNA damage in $TNF{\alpha}$-sensitive L929 cells. We chose to measure the level of 8-hydroxy-2'-deoxyguanosine (8 ohdG), which has been increasingly recognized as one of the most sensitive markers of oxidative DNA damage. Our results clearly demonstrated that the level of 8 ohdG increased in L929 cells in a $TNF{\alpha}$ dose-dependent manner. Subsequently, we asked whether small HSP has a protective effect on $TNF{\alpha}$-induced oxidative DNA damage. To accomplish this goal, we have stably transfected L929 cells with mouse small hsp cDNA (hsp25) since these cells are devoid of endogenous small hsps. We found that $TNF{\alpha}$-induced 8 ohdG was decreased in cells overexpressing exogenous small hsp. We also found that the cell killing activity of $TNF{\alpha}$ was decreased in these cells as measured by clonogenic survival. Taken together, results from the current study show that cytotoxic mechanism of $TNF{\alpha}$ involves oxidative damage of DNA and that overexpression of the small hsp reduces this oxidative damage. We suggest that the reduction of oxidative DNA damage is one of the most important protective mechanisms of small HSP against $TNF{\alpha}$.

• Biomedical Science Letters
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• v.10 no.2
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• pp.65-73
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• 2004

I report that single-stranded antisense as a part of large circular (LC-) genomic DNA of recombinant M13 phage exhibits enhanced stability, sequence specific antisense activity, and no need for target site search. A cDNA fragment (708 bp) of rat TNF-$\alpha$ was inserted into a phagemid vector, and TNF-$\alpha$ antisense molecules (TNF$\alpha$-LCAS) were produced as single-stranded circular DNA. When introduced into a rat monocyte/macrophage cell line, WRT7/P2, TNF$\alpha$-LCAS was able to ablate LPS-induced TNF-$\alpha$ mRNA to completion. The antisense effect of TNF$\alpha$-LCAS was shown to be sequence-specific because expressions of three control genes ($\beta$-actin, GAPDH and IL-1$\beta$) were not significantly altered by the antisense treatment. Further, TNF$\alpha$-LCAS was found to be highly efficacious as only 0.1 $\mu$g (0.24 nM) of TNF$\alpha$-LCAS was sufficient to block TNF-$\alpha$ expression in 1$\times10^5$ WRT7/P2 cells. I have also observed specific antisense activity in reduction of NF-$\kappa$B gene expression. The results suggest that an antisense sequence as a part of single-stranded circular genomic DNA has a specific antisense activity.

• Journal of Food Hygiene and Safety
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• v.21 no.3
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• pp.181-188
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• 2006

Tumor necrosis factor-alpha $(TNF-{\alpha})$ plays a variety of biological functions such as apoptosis, inflammation and immunity. PTEN also has various cellular function including cell growth, proliferation, migration and differentiation. Thus, possible relationships between two molecules are suggested. $(TNF-{\alpha})$has been known to downregulate PTEN via nuclear factor-kappa $B(NF-{\kappa}B)$ pathway in the human colon cell line, HT-29. However, here we show the opposite finding that $(TNF-{\alpha})$ upregulates PTEN via activation of $NF-{\kappa}B$ in HL-60 cells. $TNF-{\alpha}$ increased PTEN expression at HL-60 cells in a time- and dose-dependent manner, but the response was abolished by disruption of $NF-{\kappa}B$ with p65 anisense oligonucleotide or pyrrolidine dithiocarbamate (PDTC). We found that $TNF-{\alpha}$ activated the $NF-{\kappa}B$ pathways, evidenced by the translocation of p65 to the nucleus in $TNF-{\alpha}-treated$ cells. We conclude that $TNF-{\alpha}$ induces upregulation of PTEN expression through $NF-{\kappa}B$ activation in HL-60 cells.

• Biomolecules & Therapeutics
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• v.6 no.1
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• pp.31-36
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• 1998

Capsular polysaccharides (CPs) from Streeptococcus pneumoniae were examined for the ability to induce secretory responses in a pure population of peritoneal macrophages. The highly purified CPs were able to affect the macrophage, ie, secretion of tumor necrosis factor-alpha (TNF-$\alpha$) and nitrite. As after stimulation with CPs, secretion of TNF-u induced by these CPs reached its maximum within the first few hours of the interaction, while secretion of nitrite was increased with time. In addition, production of TNF-$\alpha$ and nitrite was increased in a dose-dependent manner. In the presence of indomethacin, CP-stimulated TNF-$\alpha$ production was not altered. In contrast, LPS with indomethacin stimulated 24.5% more TNF-$\alpha$ than LPS alone, suggesting that the intracellular signaling processes for TNF production are differentially stimulated by CP and LPS. The results demonstrate that CPs are potent inducer of macrophage secretory activities.

• 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.