• BMB Reports
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• 제44권11호
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• pp.735-740
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• 2011

Tunicamycin, an endoplasmic reticulum (ER) stress inducer, specifically inhibits N-glycosylation. The cyclic AMP (cAMP) response element-binding protein H (CREBH) was previously shown to be regulated by UPR-dependent proteolytic cleavage in the liver. On the other hand, the role of CREBH in other tissues is unknown. In the present study, tunicamycin increased the level of CREBH activation (cleavage) as well as mRNA expression in osteoblast cells. Adenoviral (Ad) overexpression of CREBH suppressed BMP2-induced expression of alkaline phosphatase (ALP) and osteocalcin (OC). Interestingly, the BMP2-induced OASIS (structurally similar to CREBH, a positive regulator of osteoblast differentiation) expression was also inhibited by CREBH overexpression. In addition, inhibition of CREBH expression using siRNA reversed the tunicamycin-suppressed ALP and OC expression. These results suggest that CREBH inhibited osteoblast differentiation via suppressing BMP2-induced ALP, OC and OASIS expression in mouse calvarial derived osteoblasts.

• Animal cells and systems
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• 제15권1호
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• pp.1-8
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• 2011

Perturbation of metabolism with increased expression of lipogenic enzymes is a common characteristic of human cancers, including prostate cancer. In the present work the overexpression of stearoyl-CoA desaturase (SCD) in LNCaP cells led to increased mRNA levels of fatty acid synthase (FAS) and acetyl-CoA-carboxylase-a, whereas micro RNA-mediated silencing of SCD inhibited the expression of these lipogenic genes in LNCaP cells. Treatment with the FAS-specific inhibitor cerulenin inhibited SCD induction of LNCaP cell proliferation. In addition, a transient transfection assay revealed the capability of cerulenin to suppress SCD and dihydrotestosterone induction of androgen receptor transcriptional activity. Furthermore, overexpression of SCD in LNCaP cells produced marked resistance to ceramide-induced cell death with reduced poly(ADP-ribose) polymerase (PARP) cleavage. In contrast, silencing of SCD expression increased Bax protein in LNCaP cells. Furthermore, addition of ceramide to SCD knockdown LNCaP cells increased cell death and caspase-3 activity with drastic increase of PARP cleavage. Together, the data indicate that SCD may provide resistance of prostate cancer cells to ceramide-induced cell death.

• Asian-Australasian Journal of Animal Sciences
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• 제32권12호
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• pp.1844-1853
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• 2019

Objective: We investigated how pituitary adenylate cyclase-activating polypeptide (PACAP) affects embryonic development during pre-in vitro maturation (pre-IVM) using porcine oocytes isolated from small follicles. Methods: We divided the follicles into the experimental groups by size (SF, small follicles; MF, medium follicles) and treated with and without PACAP and cultured for 18 hours (PreSF[-]PACAP; without PACAP, Pre-SF[+]PACAP; with PACAP) before undergoing IVM. The gene expression related to extracellular matrix formation (amphiregulin, epiregulin, and hyaluronan synthase 2 [HAS2]) and apoptosis (Bcl-2-associated X [BAX], B-cell lymphoma 2, and cysteine-aspartic acid protease 3) was investigated after maturation. The impact on developmental competence was assessed by the cleavage and blastocyst rate and total cell number of blastocysts in embryos generated from parthenogenesis (PA) and in vitro fertilization (IVF). Results: Cleavage rates in the Pre-SF(+)PACAP after PA were significantly higher than SF and Pre-SF(-)PACAP (p<0.05). The cleavage rates between MF and Pre- SF(+)PACAP groups yielded no notable differences after IVF. Pre-SF(+)PACAP displayed the higher rate of blastocyst formation and greater total cell number than SF and Pre-SF(-)PACAP (p<0.05). Cumulus cells showed significant upregulation of HAS2 mRNA in the Pre-SF(+)PACAP compared to the SF (p<0.05). In comparison to other groups, the Pre-SF(+)PACAP group displayed a downregulation in mRNA expression of BAX in matured oocytes (p<0.05). Conclusion: The PACAP treatment during pre-IVM improved the developmental potential of porcine oocytes derived from SF by regulating cumulus expansion and apoptosis of oocytes.

• 대한의생명과학회지
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• 제23권4호
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• pp.416-420
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• 2017

Endoplasmic reticulum (ER) stress induces unfolded protein response (UPR) via inositol-requiring enzyme 1 (IRE1) activation, which sends a molecular signal for X box-binding protein 1 (XBP1) mRNA splicing in the cytosol. IRE1 endoribonuclease activity induces cleavage of XBP1 mRNA. The XBP1 mRNA is then ligated by an uncharacterized RNA ligase and translated to produce spliced XBP1 by 23 nt removed in which contains the PstI restriction enzyme site. The splicing of XBP1 mRNA can be detected by semiquantitative RT-PCR, and then splicing of XBP1 is a useful tool to measure the genetic variability in ER stress. In this study, we have estimated IRE1-dependent splicing of XBP1 mRNA under conditions of various hypothermia. The results indicated that hypothermia regulated ER stress. This study demonstrated that hypothermia is closely related to ER stress and may be useful for early diagnosis of ER-associated disease.

• BMB Reports
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• 제36권6호
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• pp.538-544
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• 2003

The hepatitis C virus (HCV) is a major causative agent of chronic hepatitis and hepatocellular carcinoma. The development of alternative antiviral therapies is warranted because current treatments for the HCV infection affect only a limited number of patients and lead to significant toxicities. The HCV genome is exclusively present in the RNA form; therefore, ribozyme strategies to target certain HCV sequences have been proposed as anti-HCV treatments. In this study, we determined which regions of the internal ribosome entry site (IRES) of HCV are accessible to ribozymes by employing an RNA mapping strategy that is based on a trans-splicing ribozyme library. We then discovered that the loop regions of the domain IIIb of HCV IRES appeared to be particularly accessible. Moreover, to verify if the target sites that were predicted to be accessible are truly the most accessible, we assessed the ribozyme activities by comparing not only the trans-splicing activities in vitro but also the trans-cleavage activities in cells of several ribozymes that targeted different sites. The ribozyme that could target the most accessible site identified by mapping studies was then the most active with high fidelity in cells as well as in vitro. These results demonstrate that the RNA mapping strategy represents an effective method to determine the accessible regions of target RNAs and have important implications for the development of various antiviral therapies which are based on RNA such as ribozyme, antisense, or siRNA.

• Molecules and Cells
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• 제25권4호
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• pp.545-552
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• 2008

A hepadnaviruses replicates its DNA genome via reverse transcription of an RNA template (pregenomic RNA or pgRNA), which has a cap structure at the 5' end and a poly(A) tail at the 3' end. We have previously shown that the 5' cap is indispensable for encapsidation of the pgRNA. A speculative extension of the above finding is that the cap contributes to encapsidation via its interaction with the poly(A) tail, possibly involving eIF4E-eIF4G-PABP interaction. To test this hypothesis, poly(A)-less pgRNAs were generated via cleavage by a cis-acting hepatitis delta virus ribozyme sequence. We found that accumulation of the poly(A)-less pgRNA was markedly diminished, mostly likely due to its reduced stability. Importantly, however, the remaining poly(A)-less pgRNAs were nonetheless encapsidated and reverse transcribed normally when the reduced stability was taken account. Our finding clearly contradicts the notion that the poly(A) tail has any function in encapsidation and viral reverse transcription.

• 대한화학회지
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• 제39권6호
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• pp.453-458
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• 1995

Pb^{2+}$을 Pseudomonas alcaligenes 5S rRNA의 구조 분석에 응용하였다. Pb^{2+}$이 5S rRNA를 절단하는 방식은 5S rRNA의 삼차구조의 조사에 이용할 수 있을 것으로 기대되는 몇 가지 특징들을 보였다. Pb^{2+}$은 안정한 나선형 줄기들에는 작용하지 않는다. 단일가닥으로된 구역들 또는 내밀린 부분들은 그들의 분자내에서의 위치에 따라 다른 민감도로 작용을 받는다. 불안정한 d 나선은 전혀 작용을 받지 않는다. 불안정한 C 줄기에서는 3'쪽의 가닥만이 작용을 받고 5'쪽의 가닥은 작용을 받지 않는다. Pb^{2+}$에 의한 절단과 Xanthomonas celebensis 5S rRNA의 구조분석의 결과들에 기초하여 우리는5S rRNA에서의 삼차상호작용에 대한 작업가설을 제안하였다.

• Plant Biotechnology Reports
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• 제3권2호
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• pp.111-126
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• 2009

MicroRNAs (miRNAs) are endogenous, non-coding, small RNA molecules consisting of 21-24 nucleotides (nts) that regulate target genes at the posttranscriptional level in plants and animals. In plants, miRNAs negatively regulate target mRNAs containing a highly complementary sequence by either mRNA cleavage or translational repression. MiRNAs are processed from single-stranded precursors containing stem-loop structures by a Dicer-like enzyme and are loaded into silencing complexes, where they act on target mRNAs. Although plant miRNAs were first reported in Arabidopsis 10 years later than animal miRNAs, numerous miRNAs have since been identified from various land plants ranging from mosses to flowering plants, and their roles in diverse aspects of plant developmental processes have been characterized. Furthermore, most of the annotated plant miRNAs are evolutionarily conserved in various plants. In particular, recent functional studies using Arabidopsis mutants have contributed a great deal of information towards establishing a framework for understanding miRNA biogenesis and functional roles. Extensive appraisal of miRNA-directed regulation during a wide array of plant development and plant responses to environmental conditions has confirmed the versatile roles of miRNAs as a key component of plant molecular biology.

• 대한약침학회지
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• 제15권3호
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• pp.31-38
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• 2012

Sophorae Radix (SR) plays a role in a number of physiologic and pharmacologic functions in many organs. Objective: The aim of this study was to clarify the potential role for transient receptor potential melastatin 7 (TRPM7) channels in SR-inhibited growth and survival of AGS and MCF-7 cells, the most common human gastric and breast adenocarcinoma cell lines. Methods: The AGS and the MCF-7 cells were treated with varying concentrations of SR. Analyses of the caspase-3 and - 9 activity, the mitochondrial depolarization and the poly (ADPribose) polymerase (PARP) cleavage were conducted to determine if AGS and MCF-7 cell death occured by apoptosis. TRPM7 channel blockers ($Gd^{3+}$ or 2-APB) and small interfering RNA (siRNA) were used in this study to confirm the role of TRPM7 channels. Furthermore, TRPM7 channels were overexpressed in human embryonic kidney (HEK) 293 cells to identify the role of TRPM7 channels in AGS and MCF-7 cell growth and survival. Results: The addition of SR to a culture medium inhibited AGS and MCF-7 cell growth and survival. Experimental results showed that the caspase-3 and -9 activity, the mitochondrial depolarization, and the degree of PARP cleavage was increased. TRPM7 channel blockade, either by $Gd^{3+}$ or 2-APB or by suppressing TRPM7 expression with small interfering RNA, blocked the SR-induced inhibition of cell growth and survival. Furthermore, TRPM7 channel overexpression in HEK 293 cells exacerbated SR-induced cell death. Conclusions: These findings indicate that SR inhibits the growth and survival of gastric and breast cancer cells due to a blockade of the TRPM7 channel activity. Therefore, TRPM7 channels may play an important role in the survival of patients with gastric and breast cancer.

• 대한화학회지
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• 제43권3호
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• pp.307-314
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• 1999

대장균의 RNase P의 RNA 성분인 M1 RNA는 대장균 rnpB 유전자의 주요한 일차전사물인 선구-M1 RNA로부터 3'가공으로 생성된다. 이 가공 활성을 가지고 있는 효소 분획을 부분 정제하고 그 특성을 조사하였다. 이 활성 분획을 높은 염농도에 노출시키면 가공 활성이 불활성화하는 것으로 보아, 가공효소는 여러 효소로 이루어진 효소 복합체인 것으로 추정된다. 이 효소 분획은 화학적 핵산 가수분해효소인 납(II) 이온으로 처리하면 효소 활성을 잃지만, 효소 분획 자체에서 추출한 RNA를 가하면 효소 활성을 되찾는다. 이 결과는 효소 활성에는 RNA 분자가 필요하다는 것을 시사한다. 부분 정제한 효소로 형성되는 절단자리들의 분석 결과도, 3'가공과정이 여러 효소에 의하여 일어나고, 적어도 두 가지 다른 경로로 일어난다는 것을 암시한다.