• Parasites, Hosts and Diseases
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• 제58권4호
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• pp.393-402
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• 2020

Toxoplasma gondii is an intracellular parasite that causes severe disease when the infection occurs during pregnancy. Adenosine is a purine nucleoside involved in numerous physiological processes; however, the role of adenosine receptors in T. gondii-induced trophoblast cell function has not been investigated until now. The goal of the present study was to evaluate the intracellular signaling pathways regulated by adenosine receptors using a HTR-8/SVneo trophoblast cell model of T. gondii infection. HTR8/SVneo human extravillous trophoblast cells were infected with or without T. gondii and then evaluated for cell morphology, intracellular proliferation of the parasite, adenosine receptor expression, TNF-α production and mitogen-activated protein (MAP) kinase signaling pathways triggered by adenosine A₃ receptor (A₃AR). HTR8/SVneo cells infected with T. gondii exhibited an altered cytoskeletal changes, an increased infection rate and reduced viability in an infection time-dependent manner. T. gondii significantly promoted increased TNF-α production, A₃AR protein levels and p38, ERK1/2 and JNK phosphorylation compared to those observed in uninfected control cells. Moreover, the inhibition of A₃AR by A₃AR siRNA transfection apparently suppressed the T. gondii infection-mediated upregulation of TNF-α, A₃AR production and MAPK activation. In addition, T. gondii-promoted TNF-α secretion was dramatically attenuated by pretreatment with PD098059 or SP600125. These results indicate that A₃AR-mediated activation of ERK1/2 and JNK positively regulates TNF-α secretion in T. gondii-infected HTR8/SVneo cells.

• BMB Reports
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• 제29권6호
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• pp.530-534
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• 1996

Astrocyte are the major glial cell type in the central nervous system (CNS), and analogous to macrophage, mediates the number of immune responses such as production of cytokines including tumor necrosis factor alpha ($TNF-{\alpha}$) upon activation. $TNF-{\alpha}$ has been implicated in neuroimmunological disorders through killing oligodendrocytes and thus causing demyelination. It has been previously demonstrated that mitogen-activated T cells synthesized a 26 kDa precursor form of $TNF-{\alpha}$ which is bound to the surface of a membrane, and is later secreted as a 17 kDa mature version. In order to examine whether astrocytes would produce the transmembrane form of $TNF-{\alpha}$, astrocytes were stimulated with biological stimuli and the membrane form of $TNF-{\alpha}$ was analyzed by Western blot and FACS analysis. When astrocytes are stimulated with lipopolysaccharide (LPS), $IFN-{\gamma}/LPS$, or $IFN-{\gamma}/IL-1{\beta}$, they were able to express a membrane-anchored $TNF-{\alpha}$ of approximately 26 kDa protein which was immunoreactive to an $anti-TNF-{\alpha}$ antibody, whereas unstimulated astrocytes or astrocytes treated with $IFN-{\gamma}$ or $IL-1{\beta}$ alone was not. Our FACS data were also consistent with the immunoblot analysis. Our result suggests that the membrane form of $TNF-{\alpha}$ expressed by activated astrocytes may cause local damage to oligodendrocytes by direct cell-cell contact and contribute to demyelination observed in multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE).

• 동의생리병리학회지
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• 제16권4호
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• pp.801-809
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• 2002

CSBHT is known to improve immunological response in mice and humans. In this study, CSBHT effect was examined in the context of CD4+ T cells' survival and TCR/CD3 induced activation responses. Spleen cells from 8 week BALB/c mice were cultured in CSBHT containing medium without activation for 24, 48 hr. The MTS assay and revealed that CSBHT did not stimulate spleen lymphocytes as mitogen. Spleen lymphocytes were treated with anti-CD3e/anti-CD28 antibodies for 48hr. Flow cytometry revealed that activity of T cell decreased with CSBHT concentration. CD4+ T cells were isolated and cultured ,in CSBHT containing medium for 48 hr. CSBHT did not affect survival of sorted CD4+ T cells without any involvement of APC. In order to evaluate the direct effect of CSBHT on helper T cells's proliferative capacity prior to activation, CD4+ T cells are isolated after 24hr of culture in CSBHT containing medium and activated with and without anti-CD3e/anti-CD28 activation for 48hr. A higher level of CD69 was observed in 1 ㎍/㎖ of CSBHT treatment than control using flow cytometry. But low CD69 expression was observed in 5㎍/㎖ of CSBHT treatment. Expression of mRNA for cytokines in CD4+ T cell revealed that IL-2 expression was increased in 1 ㎍/㎖. The expression of IL-2R α, INF- γ were increased with concentration. On the other hand mRNA of IL-4 was decreased in dose dependent manner. Results suggest that CSBHT may be desirable for CD4+ T cell's activity in immune responses. Further more, CSBHT may relatively activate Th1 and inactivate Th2.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1990년도 Proceedings of International Symposium on Korean Ginseng, 1990, Seoul, Korea
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• pp.79-85
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• 1990

The aqueous extract of fresh ginseng (Panax ginseng C.A. Meyer) contains a macromolecular fraction that showed mitogenic and comitogenic activities in human peripheral blood Iymphocytes. Purification of the crude extract by size (ultrafiltration, Sephadex G-200) and charge (DEAE-cellulose. DEAE-Sepharose) yielded a semi-purified fraction (DS-3). This fraction contains at least three subgroups of anionic macromolecules with apparent molecular weight greater than 600 kilodaltons. It is a glycoprotein with a large amount of glucuronic acid. It acts as a mitogen in both T and B cells of human peripheral blood lymphocytes. It could also potentiate the mitogenic action of Concanavalin A in Iymphocyte T cells. Such potentiation is not due to increased binding of Concanavalin A to the cell surface. Its mitogenic and co-mitogenic effects do depend on the presence of extracellular Ca2+.

• 대한의생명과학회지
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• 제2권1호
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• pp.21-30
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• 1996

Mitogen-activated protein (MAP) kinase는 여러 세포증식 촉진인자들에 의하여 자신이 인산화됨으로써 활성화되어 다른 protein kinase를 인산화시키는 역할을 하는 세포내 신호전달의 중요한 효소이다. 본 연구에서는 P388 murine leukemia 세포 파쇄액에서 SP sephadex C-50, phenyl superose, Mono Q column을 통하여 MAP kinase를 분리한 결과, 44 kD와 66kD의 isoform을 확인할 수 있었다. 면역 T 세포의 $p56^{kk}$의 N-terminal로부터 유전자 재조합 방법을 통하여 glutathion-s-transferase(GST) fusion protein을 얻은 후 분리한 MAP kinase의 기질로 사용하여 본 결과, wild type과 mutant간에 인산화 정도의 차이를 확인할 수 있어 MAP kinase의 또 다른 기질로 이용할 수 있는 가능성을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권8호
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• pp.1179-1187
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• 2001

In fish both humoral and cell mediated immune responses have been reported whereas antibodies recognizing specific cellular populations have not yet been developed except for ones recognizing surface Ig molecules on B lymphocytes. Our aim was to develop and characterize monoclonal antibodies (Mabs) specific for the immune-related cells. Mabs were produced by fusion of myeloma cells (SP2/0) with Balb/c mouse spleen cells previously sensitized against Israeli carp (I. carp) kidney mononuclear cells. We obtained 44 Mabs positively reacting with I. carp kidney mononuclear cells and partially characterized 7 Mabs in the morphological and mitogen-based proliferative aspects. Fluorescence-activated cell sorter (FACS) analysis against I. carp kidney cells by using 7 different Mabs showed 80.3% for ICK 17-4, 65.1% for ICK 2-3, 64.1% for ICK 25-1, 67.5% for lCK 22-1, 70.8% for ICK 16-2, 76.8% for ICK 13-2, 79.7% for ICK II-I. Panning method was used for the isolation of Mabs specific mononuclear carp spleen cells followed by Wright's stain. The stained cell populations were identified as monocytes (ICK 17-4, ICK 2-3, ICK 25-1, ICK 22-1 and ICK 16-2), lymphocytes (ICK 11-1), and a mixed cell population of monocytes and lymphocytes (ICK 13-2). In cell proliferation assay, monocytes purified by ICK 17-4, 2-3 and 22-1 efficiently responded to Con A and PHA, while ones separated by ICK 25-1 did not react with any mitogens. Lymphocytes isolated by ICK 11-1, though it is not known whether they are T or B cells, were more responsive to Con A than PHA or LPS, suggesting that fish immune cells are somewhat different from mammalian cells in responding to mammalian T or B cell mitogens.

• Journal of Ginseng Research
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• 제41권4호
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• pp.608-614
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• 2017

Background: Ginsenoside Rg1 belongs to protopanaxatriol-type ginsenosides and has diverse pharmacological activities. In this report, we investigated whether Rg1 could upregulate muscular stem cell differentiation and muscle growth. Methods: C2C12 myoblasts, MyoD-transfected 10T1/2 embryonic fibroblasts, and HEK293T cells were treated with Rg1 and differentiated for 2 d, subjected to immunoblotting, immunocytochemistry, or immunoprecipitation. Results: Rg1 activated promyogenic kinases, p38MAPK (mitogen-activated protein kinase) and Akt signaling, that in turn promote the heterodimerization with MyoD and E proteins, resulting in enhancing myogenic differentiation. Through the activation of Akt/mammalian target of rapamycin pathway, Rg1 induced myotube growth and prevented dexamethasone-induced myotube atrophy. Furthermore, Rg1 increased MyoD-dependent myogenic conversion of fibroblast. Conclusion: Rg1 upregulates promyogenic kinases, especially Akt, resulting in improvement of myoblast differentiation and myotube growth.

• 한국식품과학회지
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• 제45권4호
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• pp.508-514
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• 2013

본 연구에서는 오리나무유래 HST의 T 세포 비활성화 효능을 확인하고 그 기전을 탐색하여 새로운 항아토피 천연소재로의 개발 가능성을 제시하고자 하였다. HST는 T 세포 mitogen으로서 anti-CD3 mAb가 처리 된 마우스 비장에서 Th 사이토카인(IL-2, IFN-${\gamma}$, IL-4, IL-5, IL-10)의 발현을 효과적으로 억제하였으며, T 세포 early activation marker인 CD25 유전자 발현이 INCA-6에서 매우 효과적으로 억제되는 것으로 보아, NFAT inactivator-유사 NFAT 탈인산화 억제 기전을 가지는 것으로 예측되었다. 또한 세포주기조절 단백질인 p21과 p27의 유전자도 HST에 의해 upregulation이 되어 효과적인 T 세포 증식 및 분화를 억제할 것으로 생각되었다. 이러한 세포주기조절 효과는 AD를 악화시키는 세균인 S. aureus 성장억제 실험에서 확인되어 향후 항박테리아 효능을 갖는 우수한 항아토피피부염 천연소재로서 HST의 활용 가치가 높을 것으로 판단된다.

• IMMUNE NETWORK
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• 제16권4호
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• pp.242-248
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• 2016

Thymic atrophy is a complication that results from exposure to many environmental stressors, disease treatments, and microbial challenges. Such acute stress-associated thymic loss can have a dramatic impact on the host's ability to replenish the necessary naïve T cell output to reconstitute the peripheral T cell numbers and repertoire to respond to new antigenic challenges. We have previously reported that treatment with the orexigenic hormone ghrelin results in an increase in the number and proliferation of thymocytes after dexamethasone challenge, suggesting a role for ghrelin in restraint stress-induced thymic involution and cell apoptosis and its potential use as a thymostimulatory agent. In an effort to understand how ghrelin suppresses thymic T cell apoptosis, we have examined the various signaling pathways induced by receptor-specific ghrelin stimulation using a restraint stress mouse model. In this model, stress-induced apoptosis in thymocytes was effectively blocked by ghrelin. Western blot analysis demonstrated that ghrelin prevents the cleavage of pro-apoptotic proteins such as Bim, Caspase-3, and PARP. In addition, ghrelin stimulation activates the Akt and Mitogen-activated protein kinases (MAPK) signaling pathways in a time/dose-dependent manner. Moreover, we also revealed the involvement of the FoxO3a pathway in the phosphorylation of Akt and ERK1/2. Together, these findings suggest that ghrelin inhibits apoptosis by modulating the stress-induced apoptotic signal pathway in the restraint-induced thymic apoptosis.

• 대한통합의학회지
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• 제12권1호
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• pp.1-10
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• 2024

Purpose: Lycopene is abundantly contained in Tomatoes and is known for diverse biological activities such as antioxidant, anti-inflammatory, and anticancer effects. In this study, the antioxidative potential of lycopene was investigated through the induction of hemeoxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor2 (Nrf2) and upstream signaling molecules, mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Aktin RAW 264.7 cells. Methods: The antioxidative potential of lycopene against oxidative stress and its molecular mechanisms were determined by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results: Lycopene treatment significantly attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS formation in a dose-dependent manner without any cytotoxicity. In addition, 50 µM of lycopene for 6 h treatment induced potent HO-1 expression and its transcription factor, Nrf2. MAPK and PI3K/Aktwere also analyzed due to their critical roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, phosphorylation of extracellular regulated kinase (ERK) was significantly induced by lycopene treatment while the activated status of c-Jun NH2-terminal kinase (JNK), p38, and Akt, were not given any effect. To confirm the antioxidative mechanism of HO-1 mediated by ERK activation, each selective inhibitor was employed in a protection assay, in which oxidative damage occurred by t-BHP. Lycopene, SnPP, and CoPP treatments reflected accelerated HO-1 expression could be a protective role against oxidative damage-initiated cell death. A selective inhibitor for ERK significantly inhibited the lycopene-induced cytoprotective effect but selective inhibitors for other signaling molecules did not attenuate the rate of t-BHP-induced cell death. Conclusion: In conclusion, lycopene potently scavenged intracellular ROS formation and enhanced the HO-1 mediated antioxidative potential through the modulation of Nrf2, MAPK signaling pathway in RAW 264.7 cells.