• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.611-626
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• 1998

Cytokines are intercellular peptide mediators that regulate homeostasis and host defense reactions in living body. Of the diversity of cytokines in terms of biological accomplishment, interleukin $1-{\beta}$($IL-1{\beta}$) and tumor necrosis factor(TNF) are the most conspicuous cytokines with a wide variety of effects on cells involved in inflammatory and immune responses, and likely to be involved in the inflammatory pathogenesis of oral tissue as well. The present study was designed to explicate the role of $IL-1{\beta}$ on inflammatory revelation of oral tissues in mice biochemically. In the Induced arthritis by injection of 10${\mu}g$ LPS shown the relaese of 0.93 ${\mu}g$ $IL-1{\beta}$/joint with a peak at at 4-5 h. and diminished at 24t and the release of $TNF_{\alpha}$ of 1.25 ${\mu}g$/joint with a peak at 2-3h and diminished at 6h. After injection of th $IL-1{\beta}$ into the joint, the mumber of leucocytes proliferated with a peak at 4-5h and diminished at 36h and the loss of proteoglycan showed with maximum at 15-30h. After injection of $IL-1{\beta}$ into the oral tissue, cycloosygenase metabolites ($PGE_2$) accumulated in the oral tissue with dose dependant. These elucidated $IL-1{\beta}$ to be inflammatory mediator in the early phase of its pathogenesis. Intraoral injection of recombinant $IL-1{\beta}$ induced the proliferation of leukocytes in situ. $IL-1{\beta}$ took an pertinent part in the development of inflammation and the succession of cellular infiltration. The results exemplify that $IL-1{\beta}$ plays a significant role in mediating inflammatory response induced by LPS in oral tissue, the inflammatory response is regulated by $IL-1{\beta}$ at an acute phase of pathogenesis.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.172-183
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• 1999

Background: Nitric oxide is a short-lived effector molecule derived from L-arginine by the nitric oxide synthase(NOS). Nitric oxide plays a role in a number of physiologic and pathophysiologic functions including host defense, edema formation, and regulation of smooth muscle tone. Some kinds of cells including macrophage are known to produce large quantities of nitric oxide in response to inflammatory stimuli such as interleukin-$1\beta$(IL-$1\beta$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), interferon-$\gamma$(IFN-$\gamma$) and lipopolysaccharide(LPS). Reactive oxygen species are also known to be important in the pathogenesis of acute cell and tissue injury such as acute lung injury model Methods: Using the RA W264.7 cells, we have examined the ability of oxidant hydrogen peroxide($H_2O_2$) to stimulate nitric oxide production and inducible NOS mRNA expression. Also, we have examined the effects of NOS inhibitors and antioxidants on $H_2O_2$ induced nitric oxide production. Results: Stimulation of RAW264.7 cells with combinations of 100 ng/ml IL-$1\beta$, 100 ng/ml TNF-$\alpha$, and 100 U/ml IFN-$\gamma$ or 100 U/ml IFN-$\gamma$ and $1{\mu}g/ml$ LPS induced the synthesis of nitric oxide as measured by the oxidation products nitrite($NO_2^-$) and nitrate($NO_3^-$). Addition of $250 {\mu}M-2$ mM $H_2O_2$ to the cytokines significantly augmented the synthesis of $NO_2^-$ and $NO_3^-$(p<0.05). When cells were incubated with increasing concentrations of $H_2O_2$ in the presence of IL-$1\beta$, TNF-$\alpha$ and IFN-$\gamma$ at constant level, the synthesis of $NO_2^-$ and $NO_3^-$ was dose-dependently increased(p<0.05). $N^G$-nitro-L-arginine methyl ester(L-NAME), dose dependently, significantly inhibited the formation of $NO_2^-$ and $NO_3^-$ in cells stimulated with LPS, IFN-$\gamma$ and $H_2O_2$ at constant level(p<0.05). Catalase significantly inhibited the $H_2O_2$-induced augmentation of cytokine-induced $NO_2^-$ and $NO_3^-$ formation(p<0.05). But, boiled catalase did not produce a significant inhibition in comparison with the native enzyme. Another antioxidant 2-mercaptoethanol and orthophenanthroline dose-dependently suppressed $NO_2^-$ and $NO_3^-$ synthesis(p<0.05). Northern blotting demonstrated that H:02 synergistically stimulated the cytokine-induced iNOS mRNA expression in RA W264.7. Conclusion: These results suggest that $H_2O_2$ contributes to inflammatory process by augmenting the iNOS expression and nitric oxide synthesis induced by cytokines.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.123-132
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• 2000

$TGF-{\beta}_1$ is a potent chemotactic factor for inflammatory cells and fibroblasts. It also stimulates the celluar source and components of extracellular matrix and the production of proteinase inhibitors. Collectively, these biologic activities lead to the accumulation and stabilization of the nascent matrix, which is vital to infection control. The objective of this study is to investigate production of $TGF-{\beta}$ in vitro fibroblast culture in the presence of Staphylococcus enterotoxin B(SEB) and/or lipopolysaccharide(LPS) and to elucidate the role of $TGF-{\beta}_1$ which may be responsible for infection control. The fibroblasts were originated from gingiva and facial dermis in 26 year-old male patient. In the presence of LPS($0.01{\mu}g$, $0.1{\mu}g$, $1.0{\mu}g$), SEB($0.01{\mu}g$, $0.l{\mu}g$, $1.0{\mu}g$) respectively, $cells(5{\times}10^3ml)$ were cultivated in vitro. At 1, 3, and 5 days after incubation, cells were counted. Also, $cells(2.5{\times}10^5ml)$ were cultivated in EMEM with LPS(0.01, 0.1 and $1.0{\mu}g$), SEB(0.01, 0.1 and $1.0{\mu}g$) respectively and $LPS(0.1{\mu}g)$ and $SEB(0.1{\mu}g)$ in combination for 24, 48, and 72 hours respectively. Culture supernatants were harvested at 1, 2, and 3 days after incubation period and triplicate culture supernatants were pooled and $TGF-{\beta}_1$ was assayed in duplicate. The results were as follows. 1. In gingival fibroblast induced with SEB and LPS respectively or in combination, the suppression of cell Proliferation occurred very significantly since 3 days after incubation, compared with the control and the production of $TGF-{\beta}_1$ occurred very significantly at 1 day after incubation, compared with the control. 2. In facial dermal fibroblast induced with SEB and LPS respectively or in combination, the suppression of cell proliferation occurred very significantly at 1 day after incubation, compared with the control. In SEB exposure, the production of $TGF-{\beta}_1$ was decreased very significantly at 1 day after incubation, compared with the control. However, in LPS, SEB and LPS exposure, the production of $TGF-{\beta}_1$ was increased very significantly at 1 day after incubation, compared with the control. In conclusion, the concentration of bacterial toxins and the incubation period correlated with cell proliferation and production of $TGF-{\beta}_1$ very significantly. The gingival and facial dermal fibroblasts have different phenotype each other The orchestrated understanding of fibroblast proliferation and $TGF-{\beta}_1$ production play an important part in host defense against the bacterial Infection and may prevent tissue necrosis such as necrotizing fasciitis and life-threatening syndrome such as multiple organ failure.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.16-22
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• 1993

Background: The Microbicidal and cytotoxic activities of neutrophils are to a large extent dependent on a burst of oxidative metabolism which generates superoxide anion, hydrogen peroxide, and other reactive products of oxygen. The respiratory burst of PMN is initiated by intracellular calcium mobilization that follows immune or particular stimulation and is very sensitive to modulation by c-AMP or adenosine. Despite its antagonism against adenosine, earlier study has demonstrated potent theophylline inhibition of the PMN respiratory burst at variable ranges of blood concentrations of theophylline in the healthy normal volunteers and in the septic animals pretreated or early post-treated with aminophylline (AMPH) or pentoxifylline. However it is unclear whether theophylline inhibits the superoxide generation or not in the established human sepsis caused by acute pneumonia, as taking into consideration of the fact that full activation of neutrophils have occurred within minutes after the septic insult in the animal experiments. Methods: We measured the $O_2$ generation of peripheral arterial neutrophils obtained from 11 human septic subjects caused by acute pneumonia before and 1 hour after completion of continuous AMPH infusion. Patients were identified and studied within 48 hour of admission. All subjects were administered an intravenous loading and maintenance dose of AMPH. The generation of $O_2$ was measured at a discrete time point (60 min) by the reduction of ferricytochrome c.PMA (10 ${\mu}g/ml$) was used as a stimulating agent. PMNs were isolated at a concentration of $2{\times}10^6$ cells/ml. The arterial oxygen tension, blood pressure and heart rates were also checked to evaluate the systemic effects of AMPH in the acute pneumonia. Results: The mean serum concentration of AMPH at 60 minutes was $8.8{\pm}0.6{\mu}g/ml$. Sixty minutes after AMPH infusion the generatition of $O_2$ was decreased from $0.076{\pm}0.034$ to $0.013{\pm}0.004$(OD) (p<0.05) and from $0.177{\pm}0.044$ to $0.095{\pm}0.042$(OD) (p<0.01) in the resting and stimulated PMNs respectively. $PaO_2$ was not changed after AMPH infusion. Conclusion: AMPH may compromise host defense by significant inhibition of neutrophil release of superoxide anion and it had no effect on improving $PaO_2$ in the acute pneumonia.

• Tuberculosis and Respiratory Diseases
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• v.51 no.4
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• pp.315-324
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• 2001

Background : IL-8 is a potent chemotactic cytokine that plays an important role in the host defense mechanism against M. tuberculosis by recruiting inflammatory cells to the site of the infection. Lung epithelial cells, as well as alveolar macrophages are known to produce IL-8 in response to M. tuberculosis. IL-8 gene expression is mainly regulated on the level of transcription by NF-${\kappa}B$. This study investigated whether or not A549 cells produce IL-8 in NF-${\kappa}B$ dependent mechanism in response to macrophages phagocytosing M. tuberculosis. Methods : Peripheral blood monocytes that were obtained from healthy donors were cultured for 24 h with M. tuberculosis and a conditioned medium(CoMTB) was obtained. As a negative control, the conditioned medium without M. tuberculosis (CoMCont) was used. A549 cells were stimulated with M. tuberculosis, CoMCont and CoMTB and the IL-8 concentration in the culture media was measured by ELISA. The CoMTB induced IL-8 mRNA expression in the A549 cells was evaluated using RT-PCR, and CoMTB induced $I{\kappa}B{\alpha}$ degradation was measured using western blot analysis. CoMTB induced nuclear translocation and DNA binding of NF-${\kappa}B$ was also examined using an electrophoretic mobility shift assay(EMSA), and the CoMTB induced NF-${\kappa}B$ dependent IL-8 transcriptional activity was measured using a luciferase reporter gene assay. Results : CoMTB induced IL-8 production by A549 cells($46.8{\pm}4.8\;ng/ml$) was higher than with direct stimulation with M. tuberculosis ($6.8{\pm}2.9\;ng/ml$). CoMTB induced IL-8 mRNA expression increased after 2 h of stimulation and was sustained for 24 h. $I{\kappa}B{\alpha}$ was degraded after 10 min of CoMTB stimulation and reappeared by 60 min. CoMTB stimulated the nuclear translocation and DNA binding of NF-${\kappa}B$. The CoMTB induced NF-${\kappa}B$ dependent IL-8 transcriptional activity($13.6{\pm}4.3$ times control) was higher than either CoMCont($2.0{\pm}0.6$ times control) or M. tuberculosis ($1.4{\pm}0.6$ times control). Conclusion : A conditioned medium of peripheral blood monocytes phagocytosing M. tuberculosis stimulates NF-${\kappa}B$ dependent IL-8 production by the lung epithelial cells.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.36-44
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• 1998

Background: IFN-$\gamma$ is known to activate mononuclear phagocytes and to mediate host defense mechanism against some intracellular microorganisms, but little is known about anti-mycobacterial activity and mechanism of IFN-$\gamma$ in human. In this study, we investigated the role of IFN-$\gamma$ in the pathogenesis of tuberculosis by observing the effect of IFN-$\gamma$ on the phagocytosis of M.tuberculosis(MTB) and on the production of TNF-$\alpha$ by human pulmonary alveolar macrophage. Method: Pulmonary alveolar macrophage(PAM) were prepared with adhesion purification method from bronchoalveolar lavage fluid obtained from 8 persorn without active lung lesion and cultured($1{\times}10^6cells/ml$) with MTB($3{\times}10^7$ bacteria/ml) with or without IFN-$\gamma$(300U/ml), LPS(0.5ug/ml) and autologous serum(10%). After 2 hours, the percentage of PAM-phagocytosed MTB was counted after AFB staining(modified Kynion method). TNF-$\alpha$ production by PAM stimulated by IFN-$\gamma$(300U/ml), MTB($1{\times}10^6bacteria/ml$) and LPS(0.5ug/ml) for 24hours was measured in culture supernatant using ELISA method. The degree of phagocytosis of MTB by PAM stimulated with IFN-$\gamma$(300U/ml) and LPS(0.5ug/ml) for 24hours was also investigated. Results: IFN-$\gamma$ did not influence the phagocytosis of MTB by PAM(percentage of PAM-phagocytosed MTB: control: $22.1{\pm}4.9$, IFN-$\gamma$: $20.3{\pm}5.3$) and did not increase TNF-$\alpha$ production by PAM (control: $21{\pm}38pg/ml$, IFN-$\gamma$: $87{\pm}106pg/ml$), and the degree of phagocytosis of MTB by PAM pre-stimulated with IFN-$\gamma$ for 24 hours, was not increased (control: $24.5{\pm}9.5$, IFN-$\gamma$: $23.4{\pm}10.1$). Conclusion: IFN-$\gamma$ does not influence on the phagocytosis of MTB and TNF-$\alpha$ production by PAM.

• Journal of Life Science
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• v.24 no.6
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• pp.664-670
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• 2014

In the present study, we investigate the role of V. vulnificus in promoting the inflammation of mouse ileal ephitelium and its related signaling pathways. ICR mice were infected orally with V. vulnificus ($1{\times}10^9CFU$) for 16 h as a representative model of food-borne infection. To find the major portal of entry of V. vulnificus in mouse intestine, we have measured the levels of bacterial colonization in small intestine, colon, spleen, and liver. V. vulnificus appeared to colonize in intestine and colon in the order of ileum >> jejunum> colon, but lack in the duodenum, spleen, and liver. V. vulnificus in ileum caused severe necrotizing enteritis and showed shortened villi heights accompanied by an expanded width and inflammation, compared with the control mice. V. vulnificus induced ileal epithelium inflammation by activating phosphorylation of PKC and membrane translocation of $PKC{\alpha}$. V. vulnificus induced the phosphorylation of ERK and JNK, but did not affect p38 MAPK phosphorylation. Notably, V. vulnificus stimulated the I-${\kappa}B$-dependent phosphorylation of NF-${\kappa}B$ in mouse ileal epithelium. Finally, the ileal infection of V. vulnificus resulted in a significant increase in expression of proinflammatory cytokines and Toll-like receptors, respectively, compared to the control. Collectively, our results indicate that V. vulnificus induces ileal epithelium inflammation by increasing NF-${\kappa}B$ phosphorylation via activation of PKC, ERK, and JNK, which is critical for host defense mechanism in food-borne infection by V. vulnificus.

• Molecules and Cells
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• v.45 no.12
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• pp.896-910
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• 2022

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and potentially fatal virus. So far, most comprehensive analyses encompassing clinical and transcriptional manifestation have concentrated on the lungs. Here, we confirmed evident signs of viral infection in the lungs and spleen of SARS-CoV-2-infected K18-hACE2 mice, which replicate the phenotype and infection symptoms in hospitalized humans. Seven days post viral detection in organs, infected mice showed decreased vital signs, leading to death. Bronchopneumonia due to infiltration of leukocytes in the lungs and reduction in the spleen lymphocyte region were observed. Transcriptome profiling implicated the meticulous regulation of distress and recovery from cytokine-mediated immunity by distinct immune cell types in a time-dependent manner. In lungs, the chemokine-driven response to viral invasion was highly elevated at 2 days post infection (dpi). In late infection, diseased lungs, post the innate immune process, showed recovery signs. The spleen established an even more immediate line of defense than the lungs, and the cytokine expression profile dropped at 7 dpi. At 5 dpi, spleen samples diverged into two distinct groups with different transcriptome profile and pathophysiology. Inhibition of consecutive host cell viral entry and massive immunoglobulin production and proteolysis inhibition seemed that one group endeavored to survive, while the other group struggled with developmental regeneration against consistent viral intrusion through the replication cycle. Our results may contribute to improved understanding of the longitudinal response to viral infection and development of potential therapeutics for hospitalized patients affected by SARS-CoV-2.

• IMMUNE NETWORK
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• v.24 no.2
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• pp.7.1-7.19
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• 2024

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×10⁵ plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×10² PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×10² PFU-virus-infected lungs from 2 dpi, but not in 1×10⁵ PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×10⁵ PFU; however, 1×1² PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1236-1251
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• 1998

Background : TNF-$\alpha$ appears to be a central mediator of the host response to sepsis. While TNF-$\alpha$ is mainly considered a proinflammatory cytokine, it can also act as a direct cytotoxic cytokine. However, there are not so many studies about the relationship bet ween TNF-$\alpha$ level and lung injury severity in ALI, particularly regarding the case of ALI caused by direct lung injury such as diffuse pulmonary infection. Recently, a natural defense mechanism, known as the stress response or the heat shock response, has been reported in cellular or tissue injury reaction. There are a number of reports examining the protective role of pre-induced heat stress proteins on subsequent LPS-induced TNF-$\alpha$ release from monocyte or macrophage and also on subsequent LPS-induced ALI in animals. However it is not well established whether the stress protein synthesis such as HSP can be induced from rat alveolar macrophages by in vitro or in vivo LPS stimulation. Methods : We measured the level of TNF-$\alpha$, the percentage of inflammatory cells in bronchoalveolar lavage fluid, protein synthesis in alveolar macrophages isolated from rats at 1, 2, 3, 4, 6, 12, and 24 hours after intratracheal LPS instillation. We performed histologic examination and also obtained histologic lung injury index score in lungs from other rats at 1, 2, 3, 4, 6, 12, 24 h after intratracheal LPS instillation. Isolated non-stimulated macrophages were incubated for 2 h with different concentration of LPS (0, 1, 10, 100 ng/ml, 1, or 10 ${\mu}g/ml$). Other non-stimulated macrophages were exposed at $43^{\circ}C$ for 15 min, then returned to at $37^{\circ}C$ in 5% CO2-95% for 1 hour, and then incubated for 2 h with LPS (0, 1, 10, 100ng/ml, 1, or 10 ${\mu}g/ml$). Results : TNF-$\alpha$ levels began to increase significantly at 1 h, reached a peak at 3 h (P<0.0001), began to decrease at 6 h, and returned to control level at 12 h after LPS instillation. The percentage of inflammatory cells (neutrophils and alveolar macrophages) began to change significantly at 2 h, reached a peak at 6 h, began to recover but still showed significant change at 12 h, and showed insignificant change at 24 h after LPS instillation compared with the normal control. After LPS instillation, the score of histologic lung injury index reached a maximum value at 6 h and remained steady for 24 hours. 35 kDa protein band was newly synthesized in alveolar macrophage from 1 hour on for 24 hours after LPS instillation. Inducible heat stress protein 72 was not found in any alveolar macrophages obtained from rats after LPS instillation. TNF-$\alpha$ levels in supernatants of LPS-stimulated macro phages were significantly higher than those of non-stimulated macrophages(p<0.05). Following LPS stimulation, TNF-$\alpha$ levels in supernatants were significantly lower after heat treatment than in those without heat treatment (p<0.05). The inducible heat stress protein 72 was not found at any concentrations of LPS stimulation. Whereas the 35 kDa protein band was exclusively found at dose of LPS of 10 ${\mu}g/ml$. Conclusion : TNF-$\alpha$ has a direct or indirect close relationship with lung injury severity in acute lung injury or acute respiratory distress syndrome. In vivo and in vitro LPS stimulation dose not induce heat stress protein 72 in alveolar macrophages. It is likely that 35 kDa protein, synthesized by alveolar macrophage after LPS instillation, does not have a defense role in acute lung injury.