• 생명과학회지
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• 제26권9호
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• pp.1027-1032
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• 2016

항원은 병원체로부터 유래한 질병인자다. 생명체는 항원에 대항하는 방어계인 면역계를 가지고 있다. 항원은 식세포작용, 항체, 보체 활성화, NK세포 혹은 MHC 분자를 통한 세포독성 T세포와 같은 방법을 통해서 처리된다. 림프절은 스트로마세포와 3차원 네트워크를 통해서 구성되어 있다. Fibroblastic reticular cells (FRC)는 림프절 T zone에서 T세포와 상호작용한다. FRC는 세포외 기질 생산과 homing 케모카인을 생산하여 감염에 대비한다. 하지만, FRC가 항원처리과정에 관련되어있다는 보고는 없다. 본 연구는 FRC의 항원처리 관련성에 대한 연구이다. 이를 위해 FRC는 대식세포, T세포, LPS, 그리고 TNFα와 같은 다양한 감염상황에 노출시켜 연구를 진행하였다. FRC가 대식세포 및 T세포와 공배양 했을 때 FRC가 형태적 변화와 FRC간 빈 공간 형성이 관찰 되었다. MMP 활성은 Y27632와 T세포에 의해 조절 되었다. 더욱이, 염증물질인 TNFα를 FRC에 처리 후 마이크로어레이를 통한 결과에서 부착분자와 MHC I antigen transporter의 발현을 조절하는 것으로 나타났다. FRC 단일층에 LPS와 대식 세포를 공배양 했을 때 NO 생성력이 크게 향상되었다. GFP antigen을 FRC와 대식세포 공배양군에 처리 했을 때 항원 흡수율이 증가되었다. 이러 결과는 FRC가 항원처리에 관여하고 있다는 것을 의미하며 이는 림프절이 항원처리과정에 연관되어 있다는 것을 제시한다.

• 생명과학회지
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• 제26권7호
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• pp.789-795
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• 2016

림프절은 이차성 면역기관중 하나이다. 림프절은 복잡한 3차원적 뼈대 구조물과 스트로마 세포로 구성되어 있다. Fibroblastic reticular cells (FRC)는 T세포와 상호작용을 위해 T zone에 주로 분포하고 있는 세포이다. FRC는 CCL21, CCL19같은 홍밍유도 케모카인을 분비하거나 감염에 대비하여 림프절 세포외기질 형성에 중요한 역할을 한다. 하지만, FRC가 직접 면역반응에 관여하는지에 대하여 많이 알려져 있지 않다. 본 연구는 면역반응에 대한 FRC의 특성 규명에 대한 것이다. 이를 위해 FRC와 대식세포의 공배양, lipopolysaccharide (LPS), TNFα 자극에 노출시켜 반응성을 조사하였다. FRC와 대식세포를 공배양 하였을 때 FRC의 형태적 변화가 유도 되었고 이로 인해 FRC가 빈 공간이 형성되는 것을 확인하였다. 용해성 ICAM-1 (sICAM-1)의 발현량이 대식세포와 ROCK 저해제, Y27632를 처리 했을 경우 증가하는 것을 단백질 수준에서 확인하였다. Matrix metalloproteinase (MMP) 활성이 LPS를 처리한 FRC에서 반응시간 의존적으로 증가하는 것을 확인하였다. 더욱이, 세포외기질에 대하여 염증물질인 TNFα를 처리 했을 경우 조절되는 것을 gene chip assay를 통해서 확인하였다. 이상의 결과는 FRC가 면역반응에 직접 관여하고 있다는 것을 의미하며 이는 림프절 스트로마도 면역반응에 관여하고 있는 것으로 사료된다.

• 생명과학회지
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• 제29권2호
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• pp.256-264
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• 2019

Lymphotoxin ${\beta}$ receptor ($LT{\beta}R$)는 TNF 계열로 림프조직의 미세구조와 기관형성에 중요한 역할을 한다. MLCK와 ROCK는 세포의 stress fiber 형성조절에 관여하는 주요 신호전달자이다. Fibroblastic reticular cell (FRC)에서 $LT{\beta}R$ 자극을 통한 이런 신호전달자들의 관련성을 알아보기 위해 ML-7 (MLCK 저해제)이 사용되었다. ML7 처리된 FRC에서 SF가 완전히 파괴되었고 anti-$LT{\beta}R$ antibody 처리 세포와 유사하게 ML7 처리 FRC에서 응축된 세포형태를 관찰 할 수 있었다. Y27632로 ROCK를 저해 했을 때 FRC의 액틴 세포골격과 세포형태 변화가 유도 되었다. FRC에서 p-MLC가 액틴과 함께 SF 구성성분을 이루었다. FRC세포 추출물로 Rho-guanosine diphosphate (GDP)/guanosine triphosphate (GTP) 교환활성을 확인했다. Agonistic anti-$LT{\beta}R$ antibody로 $LT{\beta}R$을 자극 했을 때 Rho-GDP/GTP 교환활성이 크게 감소했다. MLCK 저해처럼 $LT{\beta}R$ 자극은 MLC의 인산화를 감소시켰다. Agonistic anti-$LT{\beta}R$ antibody-treated FRC에서 세포골격 구성요소인 세포막과 세포골격 링커 역할을 하는 p-ezrin의 인산화는 감소 되었고 b- actin, 그리고 tubulin 발현도 줄었다. 이런 결과는 FRC의 $LT{\beta}R$ 신호전달을 통한 SF 조절에는 MLCK와 ROCK가 관여하고 있다는 것을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권1호
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• pp.51-57
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• 2010

It was hypothesized that NaF induces calcium sensitization in $Ca^{2+}$-controlled solution in permeabilized rat mesenteric arteries. Rat mesenteric arteries were permeabilized with $\beta$-escin and subjected to tension measurement. NaF potentiated the concentration-response curves to $Ca^{2+}$ (decreased $EC_{50}$ and increased $E_{max}$). Cumulative addition of NaF (4.0, 8.0 and 16 mM) also increased vascular tension in $Ca^{2+}$-controlled solution at pCa 7.0 or pCa 6.5, but not at pCa 8.0. NaF-induced vasocontraction and $GTP{\gamma}S$-induced vasocontraction were not additive. NaF-induced vasocontraction at pCa 7.0 was inhibited by pretreatment with Rho kinase inhibitors H1152 or Y27632 but not with a MLCK inhibitor ML-7 or a PKC inhibitor Ro31-8220. NaF induces calcium sensitization in a $Ca^{2+}$ dependent manner in $\beta$-escin-permeabilized rat mesenteric arteries. These results suggest that NaF is an activator of the Rho kinase signaling pathway during vascular contraction.

• Biomolecules & Therapeutics
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• 제25권4호
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• pp.354-361
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• 2017

Transcriptional co-activator with a PDZ-binding motif (TAZ) is an important factor in lysophosphatidic acid (LPA)-induced promotion of migration and proliferation of human mesenchymal stem cells (MSCs). The expression of TAZ significantly increased at 6 h after LPA treatment, and TAZ knockdown inhibited the LPA-induced migration and proliferation of MSCs. In addition, embryonic fibroblasts from TAZ knockout mice exhibited the reduction in LPA-induced migration and proliferation. The LPA1 receptor inhibitor Ki16425 blocked LPA responses in MSCs. Although TAZ knockdown or knockout did not reduce LPA-induced phosphorylation of ERK and AKT, the MEK inhibitor U0126 or the ROCK inhibitor Y27632 blocked LPA-induced TAZ expression along with the reduction in the proliferation and migration of MSCs. Our data suggest that TAZ is an important mediator of LPA signaling in MSCs in the downstream of MEK and ROCK signaling.

• 한국식품영양학회지
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• 제29권3호
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• pp.341-346
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• 2016

Phagocytosis is a primary and an essential step of host defense, and is triggered by the interaction of particles with specific receptor of macrophages. In this study, we investigated the effect of extracts of Rudbeckia laciniata (RLE) on the phagocytic activity of macrophage, by monitoring the phagocytosis-associated signal transduction. RLE markedly increased phagocytosis of serum-opsonized zymosan particles (SOZ), while phagocytosis of IgG-opsonized zymosan particles (IOZ) or none-opsonized zymosan particles (NOZ) remained unaffected. However, RLE did not affect the binding of opsonized zymosan particles (OZ) with the cell surface of macrophage. This suggests that RLE may regulate SOZ-induced intracellular signaling during phagocytosis of macrophage. To confirm this hypothesis, we investigated whether RLE was involved in the RhoA-mediated signal transduction during phagocytosis of SOZ. Inhibitors of the RhoA-mediated signaling pathway, such as Y-27632 (for ROCK), ML-7 (for MLCK), and Tat-C3 (for RhoA), totally blocked phagocytosis of SOZ enhanced by RLE, as well as phagocytosis of SOZ. Additionally, RhoA activity was markedly increased when cells were treated with RLE, suggesting that RLE could increase the phagocytic activity of macrophage via RhoA-ROCK/MLCK signal pathway. Thus, RLE may be used to develop functional foods for immunity.

• The Korean Journal of Physiology and Pharmacology
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• 제19권5호
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• pp.473-478
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• 2015

To see the inhibitory mechanism of gentamicin in response to electrical field stimulation (EFS) using the rat bladder smooth muscle, atropine or guanethidine was treated but had no effect. Methylsergide, a non-selective 5-$HT_1$, 5-$HT_2$ receptor antagonist was also treated but had on effect. Kinase inhibitors, such as chelerythrine (PKC inhibitor), ML-9 (MLCK inhibitor), or Y27632 (rho kinase inhibitor) were pretreated before gentamicin treatment, but did not have effect. For U73122, a phospholipase C (PLC) inhibitor however, the inhibitory effect to gentamicin was significantly attenuated in all frequencies given by the EFS. Therefore gentamicin induced inhibitory effect on EFS response in rat bladder smooth muscle was not mediated by the activation of adrenergic, cholinergic, or serotonergic receptor. The inhibition of gentamicin might be mediated through the PLC dependent pathway, but not through the PKC, MLCK or rho kinase dependent pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제17권2호
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• pp.139-147
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• 2013

Lysolipids such as LPA, S1P and SPC have diverse biological activities including cell proliferation, differentiation, and migration. We investigated signaling pathways of LPA-induced contraction in feline esophageal smooth muscle cells. We used freshly isolated smooth muscle cells and permeabilized cells from cat esophagus to measure the length of cells. Maximal contraction occurred at $10^{-6}M$ and the response peaked at 30s. To identify LPA receptor subtypes in cells, western blot analysis was performed with antibodies to LPA receptor subtypes. LPA1 and LPA3 receptor were detected at 50 kDa and 44 kDa. LPA-induced contraction was almost completely blocked by LPA receptor (1/3) antagonist KI16425. Pertussis toxin (PTX) inhibited the contraction induced by LPA, suggesting that the contraction is mediated by a PTX-sensitive G protein. Phospholipase C (PLC) inhibitors U73122 and neomycin, and protein kinase C (PKC) inhibitor GF109203X also reduced the contraction. The PKC-mediated contraction may be isozyme-specific since only $PKC{\varepsilon}$ antibody inhibited the contraction. MEK inhibitor PD98059 and JNK inhibitor SP600125 blocked the contraction. However, there is no synergistic effect of PKC and MAPK on the LPA-induced contraction. In addition, RhoA inhibitor C3 exoenzyme and ROCK inhibitor Y27632 significantly, but not completely, reduced the contraction. The present study demonstrated that LPA-induced contraction seems to be mediated by LPA receptors (1/3), coupled to PTX-sensitive G protein, resulting in activation of PLC, PKC-${\varepsilon}$ pathway, which subsequently mediates activation of ERK and JNK. The data also suggest that RhoA/ROCK are involved in the LPA-induced contraction.

• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.101-108
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• 2016

Previously we observed that human adipose-derived stem cells (hADSCs) could form aggregation during culture in the presence of human serum (HS). In the present study, we have examined if the aggregation might result from the cell migration and analyzed the difference of cell adhesivity after culture in various conditions. When cells were cultured in fetal bovine serum (FBS) alone, there was no morphological change. Similarly, cells pretreated with FBS for 1 day or cultured in a mixture of FBS and HS showed little change. In contrast, cells cultured in HS alone exhibited formation of cell-free area (spacing) and/or cell aggregation. When cells cultured in FBS or pretreated with FBS were treated with 0.06% trypsin, almost cells remained attached to the dish surfaces. In contrast, when cells cultured in HS alone were examined, most cells detached from the dish by the same treatment. Treatment of cells with forskolin, isobutylmethyl xanthine (IBMX) or LY294002 inhibited the formation of spacing whereas H89 or Y27632 showed little effect. When these cells were treated with 0.06% trypsin after culture, most cells detached from the dishes as cells cultured in HS alone did. However, cells treated with IBMX exhibited weaker adhesivity than HS alone. Based on these observations, it is suggested that HS treatment might decrease the adhesivity and induce three-dimensional migration of hADSCs, in the latter of which cAMP signaling could be involved.

• 동의생리병리학회지
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• 제17권2호
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• pp.461-466
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• 2003

The primary mechanism of smooth muscle contraction is phosphorylation of the 20 kDa myosin light chains(LC20) by a myosin light chain kinase(MLCK). Relaxation, then, is generally the result of dephosphorylation of LC20 by myosin phosphatase(MP). Changes in MP activity is one of the important mechanisms in the regulation of Ca2+-sensitivity. Inhibition of MP activity is linked to an increase in phosphorylated myosin light chain(MLC) without an increase in [Ca/sup 2+/]i-levels. It is now generally accepted that Rho-kinase phosphorylates 130 kDa regulatory and myosin binding subunits(M130, MYPT) of MP, which results in an inhibition of MP activity. In addition Rho-kinase can also directly phosphorylate MLC. In the present study, LC20 phosphorylation and MP subunits translocation to the cell membrane were investigated in freshly isolated ferret portal vein smooth muscle single cells treated with PGF2α. We also examined the effect of Y27632(10-5mol/L), Rho-kinase inhibitor, in the MP subunits localization to compare with butanol fraction of Fructus Crataegi in its effect. Butanol fraction of Fructus Crataegi(BFFC; 1㎎/㎖) was more effective in PGF2α induced contraction than those of phenylephrine in its vasodilation effect. It significantly(P<0.05) dephosphorylated the LC20 at time indicated. In addition, the dissociation of subunits are inhibited by BFCF treatment. The results indicate that, in the smooth muscle cells, the relaxation effect of BFFC is associated with increase of MP activity based on inhibition of dissociation of the catalytic and targeting subunits of the phosphatase, and thus decrease the sensitivity of LC20 phosphorylation for Ca/sup 2+/.