• Biomolecules & Therapeutics
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• 제32권1호
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• pp.115-122
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• 2024

Heat shock protein (HSP) 90 is expressed in most living organisms, and several client proteins of HSP90 are necessary for cancer cell survival and growth. Previously, we found that HSP90 was cleaved by histone deacetylase (HDAC) inhibitors and proteasome inhibitors, and the cleavage of HSP90 contributes to their cytotoxicity in K562 leukemia cells. In this study, we first established mouse xenograft models with K562 cells expressing the wild-type or cleavage-resistant mutant HSP90β and found that the suppression of tumor growth by the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was interrupted by the mutation inhibiting the HSP90 cleavage in vivo. Next, we investigated the possible function of thioredoxin interacting protein (TXNIP) in the HSP90 cleavage induced by SAHA. TXNIP is a negative regulator for thioredoxin, an antioxidant protein. SAHA transcriptionally induced the expression of TXNIP in K562 cells. HSP90 cleavage was induced by SAHA also in the thymocytes of normal mice and suppressed by an anti-oxidant and pan-caspase inhibitor. When the thymocytes from the TXNIP knockout mice and their wild-type littermate control mice were treated with SAHA, the HSP90 cleavage was detected in the thymocytes of the littermate controls but suppressed in those of the TXNIP knockout mice suggesting the requirement of TXNIP for HSP90 cleavage. We additionally found that HSP90 cleavage was induced by actinomycin D, β-mercaptoethanol, and p38 MAPK inhibitor PD169316 suggesting its prevalence. Taken together, we suggest that HSP90 cleavage occurs also in vivo and contributes to the anti-cancer activity of various drugs in a TXNIP-dependent manner.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2953-2958
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• 2015

Although associations between thioredoxin interacting protein (TXNIP) and cancers have been recognized, the effects of TXNIP on non-small cell lung cancer (NSCLC) prognosis remained to be determined in detail. In addition, while hypoxia is a key characteristic of tumor cell growth microenvironment, the effect of hypoxia on TXNIP expression is controversial. In this study, formaldehyde fixed and paraffin embedded (FFPE) samples of 70 NSCLC patients who underwent resection between January 2010 and December 2011 were obtained. Evaluation of TXNIP and hypoxia inducible factor-$1{\alpha}$ ($HIF-1{\alpha}$) protein expression in FFPE samples was made by immunohistochemistry. By Kaplan-Meier method, patients with high TXNIP expression demonstrated a significantly shorter progression free survival (PFS) compared with those with low TXNIP expression (18.0 months, 95%CI: 11.7, 24.3 versus 23.0 months, 95%CI: 17.6, 28.4, P=0.02). High TXNIP expression level was also identified as an independent prognostic factor by Cox regression analysis (adjusted hazard ratio: 2.46; 95%CI: 1.08, 5.56; P=0.03). Furthermore, TXNIP expression was found to be significantly correlated with $HIF-1{\alpha}$ expression (Spearman correlation=0.67, P=0.000). To further confirm correlations, we established a tumor cell hypoxic culture model. Expression of TXNIP was up-regulated in all three NSCLC cell lines (A549, SPC-A1, and H1299) under hypoxic conditions. This study suggests that hypoxia induces increased TXNIP expression in NSCLC and high TXNIP expression could be a poor prognostic marker.

• Molecules and Cells
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• 제38권2호
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• pp.187-194
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• 2015

Thioredoxin (TRX) is a disulfide reductase present ubiquitously in all taxa and plays an important role as a regulator of cellular redox state. Recently, a redox-independent, chaperone function has also been reported for some thioredoxins. We previously identified nodulin-35, the subunit of soybean uricase, as an interacting target of a cytosolic soybean thioredoxin, GmTRX. Here we report the further characterization of the interaction, which turns out to be independent of the disulfide reductase function and results in the co-localization of GmTRX and nodulin-35 in peroxisomes, suggesting a possible function of GmTRX in peroxisomes. In addition, the chaperone function of GmTRX was demonstrated in in vitro molecular chaperone activity assays including the thermal denaturation assay and malate dehydrogenase aggregation assay. Our results demonstrate that the target of GmTRX is not only confined to the nodulin-35, but many other peroxisomal proteins, including catalase (AtCAT), transthyretin-like protein 1 (AtTTL1), and acyl-coenzyme A oxidase 4 (AtACX4), also interact with the GmTRX. Together with an increased uricase activity of nodulin-35 and reduced ROS accumulation observed in the presence of GmTRX in our results, especially under heat shock and oxidative stress conditions, it appears that GmTRX represents a novel thioredoxin that is co-localized to the peroxisomes, possibly providing functional integrity to peroxisomal proteins.

• Journal of Veterinary Science
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• 제24권1호
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• pp.2.1-2.14
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• 2023

Background: Hypothermia is a crucial environmental factor that elevates the risk of cardiovascular disease, but the underlying effect is unclear. Objectives: This study examined the role of cold stress (CS) in cardiac injury and its underlying mechanisms. Methods: In this study, a chronic CS-induced myocardial injury model was used; mice were subjected to chronic CS (4℃) for three hours per day for three weeks. Results: CS could result in myocardial injury by inducing the levels of heat shock proteins 70 (HSP70), enhancing the generation of creatine phosphokinase-isoenzyme (CKMB) and malondialdehyde (MDA), increasing the contents of tumor necrosis factor-α (TNF-α), high mobility group box 1 (HMGB1) interleukin1b (IL-1β), IL-18, IL-6, and triggering the depletion of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Multiple signaling pathways were activated by cold exposure, including pyroptosis-associated NOD-like receptor 3 (NLRP3)-regulated caspase-1-dependent/Gasdermin D (GSDMD), inflammation-related toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-mediated nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK), as well as oxidative stressinvolved thioredoxin-1/thioredoxin-interacting protein (Txnip) signaling pathways, which play a pivotal role in myocardial injury resulting from hypothermia. Conclusions: These findings provide new insights into the increased risk of cardiovascular disease at extremely low temperatures.

• 생명과학회지
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• 제14권1호
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• pp.26-31
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• 2004

본 연구는 redox regulator로 알려 진 Ref-1 (Redox factor-1)과 결합하는 새로운 단백질을protein-protein interaction의 원리를 이용한 방법인 yeast two-hybrid assay로 검색, 동정하고, 검색된 단백질의 in vitro, in vivo 기능을 규명하는 데 그 목적을 두고, mouse 11-day Embryo cNA library를 prey로, full length REF-1을 bait로 하여 yeast strain 인 HF7C에 cotransformatiom시킨 후 histidine, leucine, tryptophan이 결핍된 SD plate에서 키워 자란 yeast transformants를 $\beta$-galactosidaseassay하여 screening하여 분리한 세 개의 clone중 한 clone이 DNA sequencing으로 확인한 결과 mouse thioredoxin임을 확인하였다.

• Molecules and Cells
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• 제44권3호
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• pp.146-159
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• 2021

DNA methylation, and consequent down-regulation, of tumour suppressor genes occurs in response to epigenetic stimuli during cancer development. Similarly, human oncoviruses, including human papillomavirus (HPV), up-regulate and augment DNA methyltransferase (DNMT) and histone deacetylase (HDAC) activities, thereby decreasing tumour suppressor genes (TSGs) expression. Ubiquitin-like containing PHD and RING finger domain 1 (UHRF1), an epigenetic regulator of DNA methylation, is overexpressed in HPV-induced cervical cancers. Here, we investigated the role of UHRF1 in cervical cancer by knocking down its expression in HeLa cells using lentiviral-encoded short hairpin (sh)RNA and performing cDNA microarrays. We detected significantly elevated expression of thioredoxin-interacting protein (TXNIP), a known TSG, in UHRF1-knockdown cells, and this gene is hypermethylated in cervical cancer tissue and cell lines, as indicated by whole-genome methylation analysis. Up-regulation of UHRF1 and decreased TXNIP were further detected in cervical cancer by western blot and immunohistochemistry and confirmed by Oncomine database analysis. Using chromatin immunoprecipitation, we identified the inverted CCAAT domain-containing UHRF1-binding site in the TXNIP promoter and demonstrated UHRF1 knockdown decreases UHRF1 promoter binding and enhances TXNIP expression through demethylation of this region. TXNIP promoter CpG methylation was further confirmed in cervical cancer tissue by pyrosequencing and methylation-specific polymerase chain reaction. Critically, down-regulation of UHRF1 by siRNA or UHRF1 antagonist (thymoquinone) induces cell cycle arrest and apoptosis, and ubiquitin-specific protease 7 (USP7), which stabilises and promotes UHRF1 function, is increased by HPV viral protein E6/E7 overexpression. These results indicate HPV might induce carcinogenesis through UHRF1-mediated TXNIP promoter methylation, thus suggesting a possible link between CpG methylation and cervical cancer.

• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.767-782
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• 2006

이 연구의 목적은 DNA microarray 분석법을 이용하여 건강한 사람치주인대섬유모세포, 건강한 사람치은섬유모세포, 복제노화된 사람치은섬유모세포, 염증성 사람치주인대 섬유모 세포의 유전자 발현 형태를 상호비교하고자 하였다. 환자의 동의하에 충치, 치주염이 없이 교정발치된 치아의 치주인대세포를 배양하여 건강한 치주인대섬유모세포로, 만성치주염으로 발거된 치아에서 채취하여 배양한 세포를 염증성 치주인대섬유모세포로 선정하였다. 구강에서 채취한 치은결체조직에서 배양한 사람치은섬유모세포를 일차 배양한 후 계대배양을 통해 복제 노화를 유도하였다. $-198^{\circ}C$의 액화질소에 저장되어 있던 2, 4, 8, 15, 16세대 세포를 실험에 이용하였다. 위의 모든 세포들은 60 mm 배양접시에서 세포들이 80-90%의 밀생이 될 때까지 5% $CO_2$, $37^{\circ}C$, 100% 습도의 배양기에서 2일 간격으로 10% FBS가 함유된 DMEM 세포 배양액을 교체하면서 세포를 배양하였다. Trizol Reagent (Invitrogen, USA)를 이용하여 제조회사의 지시에 따라 total RNA를 추출하였다. 18S RNA와 28S RNA를 확인한 후 DNA microarray 분석을 실시하였다. 4배수 이상의 변화양상을 비교시 상호 유전자 발현의 차이를 나타내었다. 건강한 사람치은섬유모세포(2세대)와 노화된 치은섬유모세포에서 가장 높은 발현변화를 나타낸 반면 DMC1 dosage suppressor of mck1 homolog, meiosis-specific homologous recombination,은 건강한 치은섬유모세포에서 가장 높게 나타났다. 염증성 치은인대섬유모세포와 건강한 치주인대 섬유모세포를 비교시, Regucalcin은 염증성 치주인대섬유모세포에서 가장 높게 나타났고, Vascular cell adhesion molecule 1도 두 번째로 높게 나타났다. 건강한 치주인대섬유모 세포와 건강한 치은섬유모세포를 비교시, IL-11과 periostin이 치주인대섬유모세포에서 높은 발현을 나타낸 반면, Prostaglandin D2 synthase 21kDa과 Thioredoxin interacting protein은 치은섬유모세포에서 높은 발현을 나타내었다. 염증성 치주인대섬유모세포와 노화된 치은섬유모세포(15세대 이상)를 비교시 149개의 유전자가 유사한 발현 수준을 나타내었다. 이 연구는 노화, 염증, 세포 형태에 따라서 유전자 수준에서 가장 높거나 높은 수준 변화를 보이는 유전자가 다를 수 있음을 나타낸다. 향후, 치주염 환자들에서, 노염, 염증, 세포 특이성에 관한 유전자 표시지를 이용하여 진단하거나 치료에 응용하기 위해서는 더 많은 연구가 필요하리라 사료된다.