• 미생물학회지
• /
• 제42권2호
• /
• pp.149-152
• /
• 2006

분열효모인 Schizosaccharomyces pombe에서 mRNA의 핵에서 세포질로의 이동에 관여할 것으로 여겨지는 spThp1 유전자의 결실돌연변이주(deletion mutant)를 제조하여 그 특성을 조사하였다. 이배체(diploid) 균주의 한 spThp1 유전자를 결실시킨 후 4분체분석(tetrad analysis)을 수행한 결과, 이 유전자는 생장에 필수적이지 않았다. 또한 결실돌연변이주는 mRNA 수송도 큰 결함을 보이지 않았다. 하지만 spThp1 는 mRNA의 운반체를 암호화하고 있는 spMex67와 합성치사(synthetic lethality)를 보였다. 이 결과는 분열효모의 spThpl도 mRNA의 핵에서 세포질로의 이동에 역할을 하고 있음을 암시한다.

• 생명과학회지
• /
• 제22권12호
• /
• pp.1637-1643
• /
• 2012

본 연구에서는 IL-$1{\beta}$ 발현에 PG의 영향을 조사하였고, 단핵세포에서 PG에 의한 IL-$1{\beta}$ 상향조절에 포함된 세포인자를 밝혔다. PG에 사람의 THP-1 세포를 노출시키면 IL-$1{\beta}$ 분비 증가뿐만 아니라 IL-$1{\beta}$ 유전자 전사를 유도하는 결과를 가져왔고, TLR-2/4의 억제제인 OxPAPC에 의해 저해되었다. U0126, SP6001250, Akti IV, rapamycin, DPI 같은 약리학적 저해제도 PG에 의한 IL-$1{\beta}$의 상향조절을 상당히 약화시켰다. 그러나 polymyxin B는 IL-$1{\beta}$ 발현에 영향을 미치지 않았다. 본 연구는 PG는 TLR-2, Akt, mTOR, MAPKs, ROS를 통하여 IL-$1{\beta}$의 발현을 상향시킴을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제36권6호
• /
• pp.481-489
• /
• 2010

Introduction: TLR-5, a member of the toll-like receptor (TLR) family, is a element of the type I transmembrane receptors, which are characterized by an intracellular signaling domain homolog to the interleukin-1 receptor. These receptors recognize microbial components, particularly bacterial flagellin. All-trans retinoic acid (atRA, tretinoin), a natural metabolite of vitamin A, acts as a growth and differentiation factor in many tissues, and is also needed for immune functions. In this study, THP-1 human macrophage-monocytes were used to examine the mechanisms by which atRA regulated the expression of TLR-5. Because the molecular mechanism underlying this regulation at the transcriptional level is also unclear, this study examined which putative transcription factors are responsible for TLR-5 expression by atRA in immune cells. Materials and Methods: This study examined whether atRA induces the expression of TLR-5 in THP-1 cells using reverse transcription-polymerase chain reaction (RT-PCR), and which transcription factors are involved in regulating the TLR-5 promoter in RAW264.7 cells using a reporter assay system. Western blot analysis was used to determine which signal pathway is involved in the expression of TLR-5 in atRA-treated THP-1 cells. Results: atRA at a concentration of 10 nM greatly induced the expression of TLR-5 in THP-1 cells. Human TLR-5 promoter contains three Sp-1/GC binding sites around -50 bp and two NF-kB binding sites at -380 bp and -160 bp from the transcriptional start site of the TLR-5 gene. Sp-1/GC is primarily responsible for the constitutive TLR-5 expression, and may also contribute to NF-kB at -160 bp to induce TLR-5 after atRA stimulation in THP-1 cells. The role of NF-kB in TLR-5 expression was further confirmed by inhibitor pyrrolidine dithiocarbamate (PDTC) experiments, which greatly reduced the TLR-5 transcription by 70-80%. Conclusion: atRA induces the expression of the human TLR-5 gene and NF-kB is a critical transcription factor for the atRA-induced expression of TLR-5. Accordingly, it is conceivable that retinoids are required for adequate innate and adaptive immune responses to agents of infectious diseases. atRA and various synthetic retinoids have been used therapeutically in human diseases, such as leukemia and other cancers due to the antiproliferative and apoptosis inducing effects of retinoids. Therefore, understanding the molecular regulatory mechanism of TLR-5 may assist in the design of alternative strategies for the treatment of infectious diseases, leukemia and cancers.

• 생명과학회지
• /
• 제32권6호
• /
• pp.421-429
• /
• 2022

본 연구에서는 죽상경화 플락에서 발견되는 펩티도글리칸이 혈관염증에서 어떠한 역할을 하는지 알아보기 위하여 염증성 사이토카인의 한 종류인 인터루킨-1 알파의 발현에 대한 영향을 조사하였다. 실험방법으로는 혈관염증을 주도하는 단핵구/대식세포인 THP-1 세포주에 펩티도글리칸을 처리하고 인터루킨-1 알파의 발현을 RT-PCR, real-time PCR, ELISA 방법으로 분석하였다. 펩티도글리칸의 처리 시간과 농도에 비례하여 단핵구/대식세포에서 인터루킨-1 알파의 전사체와 단백질 분비가 증가함을 관찰하였다. 또한 펩티도글리칸의 작용기전을 규명하기 위하여 신호전달을 차단하는 억제제를 세포에 처리하고 인터루킨-1 알파의 발현을 조사하였다. TLR2/4의 억제제인 OxPAPC 그리고 세포 kinase의 작용을 억제하는 LY294002(PI3 kinase 억제), Akti IV (Akt 억제), rapamycin (mTOR 억제), U0126 (MEK 억제), SB202190 (p38 MAPK 억제), SP6001250 (JNK 억제), DPI (NOX 억제)를 처리하는 경우 인터루킨-1 알파 전사체의 발현 그리고 단백질의 분비가 감소되었다. 반면에 LPS의 작용을 억제하는 polymyxin B는 인터루킨-1 알파의 발현에 영향을 주지 않았다. 이상의 결과는, 펩티도글리칸이 TLR2, PI3K, Akt, mTOR, MAPKs를 통하여 단핵구/대식세포의 인터루킨-1 알파 발현을 증가시키고 혈관염증에 기여한다는 것을 나타낸다.

• 미생물학회지
• /
• 제46권4호
• /
• pp.401-404
• /
• 2010

출아효모 Saccharomyces cerevisiae에서 RNA-binding 단백질인 Tho1은 mRNA가 전사되는 동안 초기 mRNA에 결합하여 mRNP 생성과 성숙한 mRNA의 핵에서 세포질로의 방출에 관여하는 것으로 여겨진다. 분열효모 Schizosaccharomyces pombe에서도 Tho1과 유사한 단백질을 암호화하는 유전자(spTho1로 명명)를 찾아 그 특성을 조사하였다. 이배체 S.pombe 균주에 하나의 spTho1 유전자만을 결실시킨 후 4분체분석을 수행한 결과, 이 유전자는 생장에 반드시 필요하지 않았다. 또한 spTho1 결실 돌연변이는 mRNA의 핵에서 세포질로의 방출도 정상적으로 보였다. 그러나 티아민에 의해 발현이 조절되는 강력한 프로모터를 이용하여 spTho1를 과발현시키면, 세포의 생장이 억제되었으며 $poly(A)^+$ RNA가 핵 안에 축적되었다. 이와 같은 결과들은 spTho1 유전자가 필수적이지는 않지만 mRNA의 핵에서 세포질로의 방출에 관여하고 있음을 시사한다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제19권3호
• /
• pp.263-268
• /
• 2015

5-Lipoxygenase (5-LO) plays a pivotal role in the progression of atherosclerosis. Therefore, this study investigated the molecular mechanisms involved in 5-LO expression on monocytes induced by LPS. Stimulation of THP-1 monocytes with LPS ($0{\sim}3{\mu}g/ml$) increased 5-LO promoter activity and 5-LO protein expression in a concentration-dependent manner. LPS-induced 5-LO expression was blocked by pharmacological inhibition of the Akt pathway, but not by inhibitors of MAPK pathways including the ERK, JNK, and p38 MAPK pathways. In line with these results, LPS increased the phosphorylation of Akt, suggesting a role for the Akt pathway in LPS-induced 5-LO expression. In a promoter activity assay conducted to identify transcription factors, both Sp1 and NF-${\kappa}B$ were found to play central roles in 5-LO expression in LPS-treated monocytes. The LPS-enhanced activities of Sp1 and NF-${\kappa}B$ were attenuated by an Akt inhibitor. Moreover, the LPS-enhanced phosphorylation of Akt was significantly attenuated in cells pretreated with an anti-TLR4 antibody. Taken together, 5-LO expression in LPS-stimulated monocytes is regulated at the transcriptional level via TLR4/Akt-mediated activations of Sp1 and NF-${\kappa}B$ pathways in monocytes.

• 생명과학회지
• /
• 제29권11호
• /
• pp.1251-1257
• /
• 2019

본 연구에서는 펩티도글리칸이 단핵세포의 $TNF-{\alpha}$ 발현에 미치는 영향을 조사하였고, 또한 펩티도글리칸에 의한 $TNF-{\alpha}$ 발현에 관련된 세포의 요소들을 연구하였다. 사람의 단핵세포주인 THP-1 세포를 펩티도글리칸에 노출시키는 경우 $TNF-{\alpha}$ 분비 증가뿐만 아니라 $TNF-{\alpha}$ 유전자 전사를 유도하는 결과를 가져왔다. TLR-2/4의 억제제인 OxPAPC은 펩티도글리칸에 의한 $TNF-{\alpha}$의 발현을 저해하였다. 그리고 U0126, SB202190, SP6001250, LY294002, Akti IV, rapamycin, NAC, DPI 같은 약리학적 저해제 또한 $TNF-{\alpha}$ 발현을 유전자/단백질 수준에서 상당히 약화시켰다. 그러나 polymyxin B는 $TNF-{\alpha}$ 발현에 영향을 주지않았다. 따라서 펩티도글리칸이 TLR-2, PI3K, Akt, mTOR, MAPKs, ROS 등을 통하여 단핵세포의 $TNF-{\alpha}$ 발현을 증가시킴을 확인하였다.

• Biomolecules & Therapeutics
• /
• 제19권3호
• /
• pp.302-307
• /
• 2011

Peptidoglycan (PGN) is detected in inflammatory cell-rich regions of human atheromatous plaques. The present study investigated the effects of PGN on CC chemokine ligand 3 (CCL3) expression, which is elevated in the atherosclerotic arteries, and determined cellular factors involved in PGN-mediated CCL3 up-regulation in mononuclear cells, with the goal of understanding the molecular mechanisms of inflammatory responses to bacterial pathogen-associated molecular patterns in diseased arteries. Exposure of human monocytic leukemia THP-1 cells to PGN resulted in enhanced secretion of CCL3 and profound induction of the CCL3 gene transcript. Both events were abrogated by oxidized 1-palmitoyl-2-arachidonosyl-sn-phosphatidylcholine, an inhibitor of Toll-like receptors 2/4. Pharmacological inhibitors such as U0126, SP6001250, Akt inhibitor IV, rapamycin, RO318220, diphenyleneiodonium chloride, and N-acetylcysteine also significantly attenuated PGN-mediated CCL3 up-regulation. However, polymyxin B, LY294002, and SB202190 did not influence CCL3 expression. We propose that PGN contributes to enhanced CCL3 expression in atherosclerotic plaques and that Toll-like receptors (TLR2), Akt, mTOR, mitogen-activated protein kinase, and reactive oxygen species are involved in that process.

• The Korean Journal of Physiology and Pharmacology
• /
• 제17권2호
• /
• pp.133-137
• /
• 2013

Vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), P- and E-selectin play a pivotal role for initiation of atherosclerosis. Ginsenoside, a class of steroid glycosides, is abundant in Panax ginseng root, which has been used for prevention of illness in Korea. In this study, we investigated the mechanism(s) by which ginsenoside Rg2 may inhibit VCAM-1 and ICAM-1 expressions stimulated with lipopolysaccharide (LPS) in human umbilical vein endothelial cell (HUVEC). LPS increased VCAM-1 and ICAM-1 expression. Ginsenoside Rg2 prevented LPS-mediated increase of VCAM-1 and ICAM-1 expression. On the other hand, JSH, a nuclear factor kappa B (NF-${\kappa}B$) inhibitor, reduced both VCAM-1 and ICAM-1 expression stimulated with LPS. SB202190, inhibitor of p38 mitogen-activated protein kinase (p38 MAPK), and wortmannin, phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, reduced LPS-mediated VCAM-1 but not ICAM-1 expression. PD98059, inhibitor of mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) did not affect VCAM-1 and ICAM-1 expression stimulated with LPS. SP600125, inhibitor of c-Jun N-terminal kinase (JNK), reduced LPS-mediated ICAM-1 but not VCAM-1 expression. LPS reduced IkappaB${\alpha}$ ($I{\kappa}B{\alpha}$) expression, in a time-dependent manner within 1 hr. Ginsenoside Rg2 prevented the decrease of $I{\kappa}B{\alpha}$ expression stimulated with LPS. Moreover, ginsenoside Rg2 reduced LPS-mediated THP-1 monocyte adhesion to HUVEC, in a concentration-dependent manner. These data provide a novel mechanism where the ginsenoside Rg2 may provide direct vascular benefits with inhibition of leukocyte adhesion into vascular wall thereby providing protection against vascular inflammatory disease.

• Biomolecules & Therapeutics
• /
• 제21권1호
• /
• pp.42-48
• /
• 2013

Nystatin, a polyene antifungal antibiotic, is a cholesterol sequestering agent. The antifungal agent alters composition of the plasma membrane of eukaryotic cells, whereas its effects on cells are poorly investigated. In the current study, we investigated the question of whether nystatin was able to induce expression of macrophage inflammatory protein-1 (MIP-1). THP-1 cells rarely express MIP-$1{\alpha}$ and MIP-$1{\beta}$, however, upon exposure to nystatin, significantly elevated expression of MIP-$1{\alpha}$ and MIP-$1{\beta}$ was observed in a dose-dependent fashion at the messenger and protein levels. Cellular factors activated by nystatin as well as involved in nystatin-induced expression of MIP-1 proteins were identified in order to understand the molecular mechanisms of action of the anti-fungal agent. Treatment with nystatin resulted in enhanced phosphorylation of Akt, ERK, p38 MAPK, and JNK. Abrogation or significant attenuation of nystatin-induced expression of MIP-$1{\alpha}$ and MIP-$1{\beta}$ was observed by treatment with Akt inhibitor IV, LY294002, and SP6001250. Inhibition of ERK or p38MAPK using U0126 and SB202190 did not lead to attenuation of MIP-1 expression. In addition, inhibitors of protein kinase C, such as GF109203X and Ro-318220, also attenuated expression of MIP-1. These results indicate that nystatin is able to activate multiple cellular kinases and, among them, Akt and JNK play primary roles in nystatin-induced expression of MIP-1 proteins.