• 생명과학회지
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• 제8권2호
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• pp.119-125
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• 1998

dsRNA결합인자인 RBF단백질을 정제하여 이의 단일 또는 이중선의 RNA 또는 DNA 와의 결합도를 측정하였다ㅓ. RBF단백질은 이들과 각각 반응시켜 그 결합도는 SDS-PAGE에 의하여 비교관찰하였다. RBF단백질은 dsRNA와은 강한 결합력을 나타낸 반면 기타의 핵산구조에 대해서는 이러한 결과를 나타내지 못하였다. 인산화 실험의 결과, RBF단백질은 poly(I) : poly(C)의 존재하에서 사람 도는 쥐 모두로 부터의 PKR 효소의 자가인산화를 유사한 방식으로 억제하였다. 이는 다른 종류의 진핵세포생물에서 단백질합성조절을 위한 PKR과 RBF가 유사한 경쟁적 관련성을 유지하면서 존재함을 시사하고 있다.

• Biomolecules & Therapeutics
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• 제28권3호
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• pp.272-281
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• 2020

Environmental agents, including viral and bacterial infectious agents, are involved in the alteration of physicochemical and biological parameters in the nasal epithelium. Hyaluronan (HA) has an important role in the regulation of tissue healing properties. High molecular weight HA (HMW-HA) shows greater anti-inflammatory responses than medium molecular weight HA (MMW-HA) and low molecular weight HA (LMW-HA). We investigated the effect of HMW-HA, MMW-HA and LMW-HA on the regulation of physicochemical and biological parameters in an "in vitro" model that might mimic viral infections of the nasal epithelium. Human nasal epithelial cell line RPMI2650 was stimulated with double-stranded RNA (dsRNA) Poly(I:C) for 5 days in air-liquid-interface (ALI) culture (3D model of airway tissue). dsRNA Poly(I:C) treatment significantly decreased transepithelial electrical resistance (TEER) in the stratified nasal epithelium of RPMI2650 and increased pH values, rheological parameters (elastic G' and viscous G''), and Muc5AC and Muc5B production in the apical wash of ALI culture of RPMI2650 in comparison to untreated cells. RPMI2650 treated with dsRNA Poly(I:C) in the presence of HMW-HA showed lower pH values, Muc5AC and Muc5B production, and rheological parameters, as well as increased TEER values in ALI culture, compared to cells treated with Poly(I:C) alone or pretreated with LMW-HA and MMW-HA. Our 3D "in vitro" model of epithelium suggests that HMW-HA might be a coadjuvant in the pharmacological treatment of viral infections, allowing for the control of some physicochemical and biological properties affecting the epithelial barrier of the nose during infection.

• BMB Reports
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• 제52권2호
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• pp.133-138
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• 2019

Upon viral infection, the 2', 5'-oligoadenylate synthetase (OAS)-ribonuclease L (RNaseL) system works to cleave viral RNA, thereby blocking viral replication. However, it is unclear whether OAS proteins have a role in regulating gene expression. Here, we show that OAS1 and OAS3 act as negative regulators of the expression of chemokines and interferon-responsive genes in human macrophages. Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (Cas9) technology was used to engineer human myeloid cell lines in which the OAS1 or OAS3 gene was deleted. Neither OAS1 nor OAS3 was exclusively responsible for the degradation of rRNA in macrophages stimulated with poly(I:C), a synthetic surrogate for viral double-stranded (ds)RNA. An mRNA sequencing analysis revealed that genes related to type I interferon signaling and chemokine activity were increased in $OAS1^{-/-}$ and $OAS3^{-/-}$ macrophages treated with intracellular poly(I:C). Indeed, retinoic-acid-inducible gene (RIG)-I- and interferon-induced helicase C domain-containing protein (IFIH1 or MDA5)-mediated induction of chemokines and interferon-stimulated genes was regulated by OAS3, but Toll-like receptor 3 (TLR3)- and TLR4-mediated induction of those genes was modulated by OAS1 in macrophages. However, stimulation of these cells with type I interferons had no effect on OAS1- or OAS3-mediated chemokine secretion. These data suggest that OAS1 and OAS3 negatively regulate the expression of chemokines and interferon-responsive genes in human macrophages.

• Molecules and Cells
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• 제27권1호
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• pp.47-54
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• 2009

A cDNA clone for a transcript preferentially expressed during an early phase of flooding was isolated from Nicotiana tabacum. Nucleotide sequencing of the cDNA clone identified an open reading frame that has high homology to the previously reported glycine-rich RNA-binding proteins. The open reading frame consists of 157 amino acids with an N-terminal RNA-recognition motif and a C-terminal glycine-rich domain, and thus the cDNA clone was designated as Nicotiana tabaccum glycine-rich RNA-binding protein-1 (NtGRP1). Expression of NtGRP1 was upregulated under flooding stress and also increased, but at much lower levels, under conditions of cold, drought, heat, high salt content, and abscisic acid treatment. RNA homopolymer-binding assay showed that NtGRP1 binds to all the RNA homopolymers tested with a higher affinity to poly r(G) and poly r(A) than to poly r(U) and poly r(C). Nucleic acid-binding assays showed that NtGRP1 binds to ssDNA, dsDNA, and mRNA. NtGRP1 suppressed expression of the fire luciferase gene in vitro, and the suppression of luciferase gene expression could be rescued by addition of oligonucleotides. Collectively, the data suggest NtGRP1 as a negative modulator of gene expression by binding to DNA or RNA in bulk that could be advantageous for plants in a stress condition like flooding.

• BMB Reports
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• 제50권1호
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• pp.25-30
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• 2017

In the central nervous system, viral infection can induce inflammation by up-regulating pro-inflammatory mediators that contribute to enhanced infiltration of immune cells into the central nervous areas. Celastrol is known to exert various regulatory functions, including anti-microbial activities. In this study, we investigated the regulatory effects and the mechanisms of action of celastrol against astrocytes activated with polyinosinic-polycytidylic acid (poly(I:C)), a synthetic dsRNA, as a model of pro-inflammatory mediated responses. Celastrol significantly inhibited poly(I:C)-induced expression of adhesion molecules, such as ICAM-1/VCAM-1, and chemokines, such as CCL2, CXCL8, and CXCL10, in CRT-MG human astroglioma cells. In addition, celastrol significantly suppressed poly(I:C)-induced activation of JNK MAPK and STAT1 signaling pathways. Furthermore, celastrol significantly suppressed poly(I:C)-induced activation of the $NF-{\kappa}B$ signaling pathway. These results suggest that celastrol may exert its regulatory activity by inhibiting poly(I:C)-induced expression of pro-inflammatory mediators by suppressing activation of JNK MAPK-STAT1/$NF-{\kappa}B$ in astrocytes.

• Biomolecules & Therapeutics
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• 제25권6호
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• pp.641-647
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• 2017

Galangin (3,5,7-trihydroxyflavone) is a polyphenolic compound abundant in honey and medicinal herbs, such as Alpinia officinarum. In this study, we investigated the anti-inflammatory effects of galangin under in vitro and in vivo neuroinflammatory conditions caused by polyinosinic-polycytidylic acid (poly(I:C)), a viral mimic dsRNA analog. Galangin suppressed the production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in poly(I:C)-stimulated BV2 microglia. On the other hand, galangin enhanced anti-inflammatory interleukin (IL)-10 production. Galangin also suppressed the expression of pro-inflammatory markers in poly(I:C)-injected mouse brains. Further mechanistic studies showed that galangin inhibited poly(I:C)-induced nuclear factor (NF)-${\kappa}B$ activity and phosphorylation of Akt without affecting MAP kinases. Interestingly, galangin increased the expression and transcriptional activity of peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, known to play an anti-inflammatory role. To investigate whether PPAR-${\gamma}$ is involved in the anti-inflammatory function of galangin, BV2 cells were pre-treated with PPAR-${\gamma}$ antagonist before treatment of galangin. We found that PPAR-${\gamma}$ antagonist significantly blocked galangin-mediated upregulation of IL-10 and attenuated the inhibition of tumor necrosis factor (TNF)-${\alpha}$ and IL-6 in poly(I:C)-stimulated microglia. In conclusion, our data suggest that PI3K/Akt, NF-${\kappa}B$, and PPAR-${\gamma}$ play a pivotal role in mediating the anti-inflammatory effects of galangin in poly(I:C)-stimulated microglia.

• Biomolecules & Therapeutics
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• 제30권2호
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• pp.170-178
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• 2022

The airway epithelium is equipped with the ability to resist respiratory disease development and airway damage, including the migration of airway epithelial cells and the activation of TLR3, which recognizes double-stranded (ds) RNA. Primary cilia on airway epithelial cells are involved in the cell cycle and cell differentiation and repair. In this study, we used Beas-2B human bronchial epithelial cells to investigate the effects of the TLR3 agonist polyinosinic:polycytidylic acid [Poly(I:C)] on airway cell migration and primary cilia (PC) formation. PC formation increased in cells incubated under serum deprivation. Migration was faster in Beas-2B cells pretreated with Poly(I:C) than in control cells, as judged by a wound healing assay, single-cell path tracking, and a Transwell migration assay. No changes in cell migration were observed when the cells were incubated in conditioned medium from Poly(I:C)-treated cells. PC formation was enhanced by Poly(I:C) treatment, but was reduced when the cells were exposed to the ciliogenesis inhibitor ciliobrevin A (CilioA). The inhibition of Beas-2B cell migration by CilioA was also assessed and a slight decrease in ciliogenesis was detected in SARS-CoV-2 spike protein (SP)-treated Beas-2B cells overexpressing ACE2 compared to control cells. Cell migration was decreased by SP but restored by Poly(I:C) treatment. Taken together, our results demonstrate that impaired migration by SP-treated cells can be attenuated by Poly(I:C) treatment, thus increasing airway cell migration through the regulation of ciliogenesis.

• The Korean Journal of Physiology and Pharmacology
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• 제14권4호
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• pp.235-240
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• 2010

Toll-like receptors (TLRs) functionally expressed in salivary epithelial cells, but their roles remain elusive. Among TLRs family, TLR3 is activated by dsRNA, a byproduct of viral infection. The aim of this study was to investigate the role of TLR3 in the inflammatory immune responses using HSG cells. Reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR and ELISA were performed to identify expression of TLRs and TLR3-mediated chemokine inductions. The chemotaxis assay of activated T lymphocytes was also performed. Treatment of HSG cells with polyinosinic: polycytidylic acid (poly(I:C)) significantly increased interferon-$\gamma$-inducible protein 10 (IP-10), interferoninducible T-cell $\alpha$ chemoattractant (I-TAC), and regulated on activation, normal T-cells expressed and secreted (RANTES) gene expressions in a concentration-dependent manner. Anti-TLR3 antibody blocked the increases of IP-10 and I-TAC genes. Poly(I:C)-induced increases of IP-10 and I-TAC were also confirmed at protein levels from cell lysates, but their release into extracellular medium was detected only in IP-10. We found that the culture media from HSG cells stimulated with poly(I:C) significantly increases T lymphocyte migration. Our results suggest that TLR3 plays an important role in chemokine induction, particularly IP-10, in salivary epithelial cells.

• 한국동물학회지
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• 제27권2호
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• pp.103-116
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• 1984

유전자 구조 및 유전정보 흐름의 차이로 인하여 고등생물의 유전자를 미생물에 직접 cloning하면 원하는 유전자 산물을 얻지 못하는 경우가 많다. 이것을 극복하기 위해서는 화학적인 방법으로 유전자를 합성하든지, 또는 역제효소를 사용하여 고등생물의 mRNA로부터 유전자를 합성하여 cloning하는 방법을 사용한다. 본 연구에서는 oligo(dT)-cellulose column 방법으로 순수분리한 plasmid pBR322의 Pst I site에 cloning하였다. 우선 AMV reverse transcriptase로 primary cDNA를 합성하고, 알칼리를 처리하여 주형 RNA를 제거했다. 이번에는 이 primary cDNA를 주형으로 Klenow enzyme과 reverse transcriptase를 차례로 처리하여 double stranded DNA를 합성하고, 이 때 5' end 근처에 형성되는 hairpin loop을 Sl nuclease로 제거했다. Terminal deoxynucleotidyl transferase를 사용하여, 합성된 dsDNA에는 poly(dC) track을, Pst I endonuclease를 처리한 plasmid DNA에서는 poly(dG) track을 각각 붙인다음 이들을 서로 annealing시키고 E. coli에 transformation시켜서 크기가 큰 plasmid를 갖는 clone을 cracking 방법으로 일처 선별하였다. 이렇게 선별된 clone을 in 냐셔 hybridization 방법으로 조사하여 globin DNA가 들어간 colony를 이차 선별하고 여러 restriction enzyme으로 잘라보아 globin DNA가 cloning된 것을 확인하였다. 토끼 hemoglobin으로 immunize한 rat (Wistar)에서 뽑은 제일차 혈청과 염소에서 뽑은 제이차 혈청의 antibody를 사용한 radioimmunoassay방법으로, cloning된 globin gene이 대장균내에서 발현되는 지의 여부를 살펴 보았는데, 박테리아의 $\\beta$-lactamase와 토끼의 globin이 결합된 chimeric protein이 대장균 내에서 다량 합성되며, 이 단백질은 토끼 hemoglobin의 antigenic determinant를 가지고 있음을 알 수 있었다.