• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1101-1108
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• 2008

Geldanamycin and its analogs are important anticancer agents that inhibit the newly targeted heat-shock protein (Hsp) 90, which is a chaperone protein in eukaryotic cells. To resolve which geldanamycin biosynthetic genes are responsible for particular post-polyketide synthase (PKS) processing steps and in which order the reactions occur, we individually inactivated candidate genes in Streptomyces hygroscopicus subsp. duamyceticus JCM4427 and isolated and elucidated the structures of intermediates from each mutant. The results indicated that gel7 governs at least one of the benzoquinone ring oxidation steps. The gel16 was found to be involved in double-bond formation between C-4 and C-5 of 4,5-dihydrogeldanamycin, which confirmed our previous findings that this double bond is reduced during the post-PKS modification of the polyketide assembly. In addition, pro-geldanamycin, which does not possess a double bond at C-4/5, was purified from the gel7 and gel8 double-gene-inactivated mutant.

• Biomolecules & Therapeutics
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• 제22권4호
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• pp.295-300
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• 2014

The actin cytoskeleton plays an important role in macrophage-mediated inflammatory responses by modulating the activation of Src and subsequently inducing nuclear factor (NF)-${\kappa}B$ translocation. In spite of its critical functions, few papers have examined how the actin cytoskeleton can be regulated by the activation of toll-like receptor (TLR). Therefore, in this study, we further characterized the biological value of the actin cytoskeleton in the functional activation of macrophages using an actin cytoskeleton disruptor, cytochalasin B (Cyto B), and explored the actin cytoskeleton's involvement in morphological changes, cellular attachment, and signaling events. Cyto B strongly suppressed the TLR4-mediated mRNA expression of inflammatory genes such as cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-${\alpha}$, and inducible nitric oxide (iNOS), without altering cell viability. This compound also strongly suppressed the morphological changes induced by lipopolysaccharide (LPS), a TLR4 ligand. Cyto B also remarkably suppressed NO production under non-adherent conditions but not in an adherent environment. Cyto B did not block the co-localization between surface glycoprotein myeloid differentiation protein-2 (MD2), a LPS signaling glycoprotein, and the actin cytoskeleton under LPS conditions. Interestingly, Cyto B and PP2, a Src inhibitor, enhanced the phagocytic uptake of fluorescein isothiocyanate (FITC)-dextran. Finally, it was found that Cyto B blocked the phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at 1 min and the phosphorylation of heat shock protein 27 (HSP27) at 5 min. Therefore, our data suggest that the actin cytoskeleton may be one of the key components involved in the control of TLR4-mediated inflammatory responses in macrophages.

• Parasites, Hosts and Diseases
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• 제53권6호
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• pp.789-793
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• 2015

In order to explore tick proteins as potential targets for further developing vaccine against ticks, the total proteins of unfed female Dermacentor silvarum were screened with anti-D. silvarum serum produced from rabbits. The results of western blot showed that 3 antigenic proteins of about 100, 68, and 52 kDa were detected by polyclonal antibodies, which means that they probably have immunogenicity. Then, unfed female tick proteins were separated by 12% SDS-PAGE, and target proteins (100, 68, and 52 kDa) were cut and analyzed by LC-MS/MS, respectively. The comparative results of peptide sequences showed that they might be vitellogenin (Vg), heat shock protein 60 (Hsp60), and fructose-1, 6-bisphosphate aldolase (FBA), respectively. These data will lay the foundation for the further validation of antigenic proteins to prevent infestation and diseases transmitted by D. silvarum.

• Molecules and Cells
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• 제41권6호
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• pp.562-574
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• 2018

The tazarotene-induced gene 1 (TIG1) protein is a retinoidinducible growth regulator and is considered a tumor suppressor. Here, we show that DnaJ heat shock protein family member C8 (DNAJC8) is a TIG1 target that regulates glycolysis. Ectopic DNAJC8 expression induced the translocation of pyruvate kinase M2 (PKM2) into the nucleus, subsequently inducing glucose transporter 1 (GLUT1) expression to promote glucose uptake. Silencing either DNAJC8 or PKM2 alleviated the upregulation of GLUT1 expression and glucose uptake induced by ectopic DNAJC8 expression. TIG1 interacted with DNAJC8 in the cytosol, and this interaction completely blocked DNAJC8-mediated PKM2 translocation and inhibited glucose uptake. Furthermore, increased glycose uptake was observed in cells in which TIG1 was silenced. In conclusion, TIG1 acts as a pivotal repressor of DNAJC8 to enhance glucose uptake by partially regulating PKM2 translocation.

• 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.

• Parasites, Hosts and Diseases
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• 제62권3호
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• pp.351-364
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• 2024

The gut microbiome plays an essential role in host immune responses, including allergic reactions. However, commensal gut microbiota is extremely sensitive to antibiotics and excessive usage can cause microbial dysbiosis. Herein, we investigated how changes in the gut microbiome induced by ampicillin affected the production of IgG1 and IgG2a antibodies in mice subsequently exposed to Anisakis pegreffii antigens. Ampicillin treatment caused a notable change in the gut microbiome as shown by changes in both alpha and beta diversity indexes. In a 1-dimensional immunoblot using Anisakis-specific anti-mouse IgG1, a 56-kDa band corresponding to an unnamed Anisakis protein was detected using mass spectrometry analysis only in ampicillin-treated mice. In the Anisakis-specific anti-mouse IgG2a-probed immunoblot, a 70-kDa band corresponding to heat shock protein 70 (HSP70) was only detected in ampicillin-treated and Anisakis-immunized mice. A 2-dimensional immunoblot against Anisakis extract with immunized mouse sera demonstrated altered spot patterns in both groups. Our results showed that ampicillin treatment altered the gut microbiome composition in mice, changing the immunization response to antigens from A. pegreffii. This research could serve as a basis for developing vaccines or allergy immunotherapies against parasitic infections.

• 한국가금학회지
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• 제44권1호
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• pp.1-9
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• 2017

본 연구는 한국재래계(KNC)와 백색레그혼(WLH)에서 lipopolysaccharide(LPS)감염 스트레스가 닭의 품종간 스트레스 연관 유전자들의 발현에 미치는 영향을 비교 분석하고자 실시되었다. 공시계를 대상으로 생리식염수(대조구)와 LPS(처리구)를 복강에 투여한 후, 시간(0, 48 hr) 및 처리별 각 개체로부터 간 조직을 취하고, microarray 및 quantitative RT-PCR(qRT-PCR) 분석을 하였다. 처리에 따른 유전자 발현차이를 보면, KNC(대조구)와 KNC에 LPS를 처리한 경우(KNC-LPS)를 비교한 결과, 대조구 대비 2배 이상 유전자의 발현이 증가한 유전자의 수는 1,044개, 발현이 감소한 유전자의 수는 1,000개였다. WLH(대조구)를 WLH-LPS와 비교한 경우, 유전자의 발현이 증가한 유전자의 수는 1,193개, 발현이 감소한 유전자의 수는 1,072개였다. LPS 처리에 따른 스트레스 연관 유전자들의 microarray 발현에서 스트레스연관 유전자들의 발현은 두 품종 모두에서 감소하였으며, 품종 간 차이는 없는 것으로 나타났다. Microarray의 결과를 바탕으로 HSP90, HMGCR, ATF4, SREBP1, XBP1 등의 유전자 발현을 qRT-PCR을 이용하여 검증한 결과, 대조구와 LPS 감염구 간에 유의적 차이를 나타내었다(P<0.05). 세포 수준의 스트레스(ER 스트레스)에서 ATF4, XBP1, SREBP1은 화이트레그혼에서 microarray와 qRT-PCR에서와 같이 이들 유전자들의 발현이 억제되는 것을 보여주었다. 그러나 한국 재래계에서는 ATF4를 제외한 유전자들은 LPS에 의해 영향을 받지 않거나(XBP1), 오히려 증가(SREBP)하는 양상을 보였다. ER-stress 연관 유전자들의 발현 양상으로 볼 때, KNC이 WLH에 비하여 LPS 감염에 더 민감하게 반응하는 것으로 보인다. HMGCR은 두 품종간에 LPS에 의한 상호작용이 없는 것으로 보아, HMGCR 발현에 의한 감염 차이점을 찾을 수 없었다. 한국재래계에서 HSP70은 LPS 처리 후에 대조구에 비하여 약 2.5배 이상 높은 발현을 보였으나, 백색 레그혼에서는 낮은 발현 양상을 나타내었다. 스트레스 지표 유전자들의 종류뿐만 아니라, 스트레스 종류(예: 환경스트레스, 감염스트레스)에 따라 유전자들의 발현 반응에 차이가 있음을 보여주었다. LPS 감염스트레스에 따른 스트레스연관 유전자 발현연구는 닭의 품종별 질병 저항성 및 동물복지 관련 지표의 탐색에 기여할 것으로 사료된다.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1126-1141
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• 2021

Recent evidence has shown that methionine (Met) supplementation can improve milk protein synthesis under hyperthermia (which reduces milk production). To explore the mechanism by which milk protein synthesis is affected by Met supplementation under hyperthermia, mammary alveolar (MAC-T) cells were incubated at a hyperthermic temperature of 42℃ for 6 h in media with different concentrations of Met. While the control group (CON) contained a normal amino acid concentration profile (60 ㎍/mL of Met), the three treatment groups were supplemented with Met at concentrations of 10 ㎍/mL (MET70, 70 ㎍/mL of Met), 20 ㎍/mL (MET80, 80 ㎍/mL of Met), and 30 ㎍/mL (MET90,90 ㎍/mL of Met). Our results show that additional Met supplementation increases the mRNA and protein levels of BCL2 (B-cell lymphoma-2, an anti-apoptosis agent), and decreases the mRNA and protein levels of BAX (Bcl-2-associated X protein, a pro-apoptosis agent), especially at an additional supplementary concentration of 20 ㎍/mL (group Met80). Supplementation with higher concentrations of Met decreased the mRNA levels of Caspase-3 and Caspase-9, and increased protein levels of heat shock protein (HSP70). The total protein levels of the mechanistic target of rapamycin (mTOR) and the mTOR signalling pathway-related proteins, AKT, ribosomal protein S6 kinase B1 (RPS6KB1), and ribosomal protein S6 (RPS6), increased with increasing Met supplementation, and peaked at 80 ㎍/mL Met (group Met80). In addition, we also found that additional Met supplementation upregulated the gene expression of αS1-casein (CSN1S1), β-casein (CSN2), and the amino acid transporter genes SLC38A2, SLC38A3 which are known to be mTOR targets. Additional Met supplementation, however, had no effect on the gene expression of κ-casein (CSN3) and solute carrier family 34 member 2 (SLC34A2). Our results suggest that additional Met supplementation with 20 ㎍/mL may promote the synthesis of milk proteins in bovine mammary epithelial cells under hyperthermia by inhibiting apoptosis, activating the AKT-mTOR-RPS6KB1 signalling pathway, and regulating the entry of amino acids into these cells.

• 한국가금학회지
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• 제47권2호
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• pp.95-105
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• 2020

본 연구는 한국토종닭 5품종 (재래황갈종, 토착로드종, 토착레그혼종, 토착코니시종 및 한국오계)에 대한 생산 특성 및 생리적 특성을 제시하고자 이들의 생산능력, 강건성 및 스트레스 반응 정도를 살펴보았다. 분석 대상으로 총 493수를 공시하고, 생산능력의 평가를 위해 생존율, 체중, 초산일령, 산란율 및 난중을 조사하였고, 강건성 및 스트레스 반응정도를 측정하기 위하여 텔로미어 함유율, heterophil-lymphocyte 비율, HSP-70, HSP-90α 및 HSP-90β 유전자 발현율을 분석하였다. 실험 결과, 생존율은 토착로드종이 99%로 가장 높았고, 한국오계가 91%로 가장 낮았다. 발생시부터 50주령까지의 체중은 토착코니시종, 토착로드종, 한국재래닭, 한국오계, 토착레그혼종의 순으로 변동없이 높게 나타났다. 22주령부터 50주령까지의 평균일계산란율은 토착레그혼종이 75%로 가장 높았고, 토착코니시종이 10%로 가장 낮게 나타났다. 생리적 지표 분석 결과, 텔로미어 함유율은 토착로드종이 가장 높았으며, 토착코니시종이 가장 낮았다. Heterophil-lymphocyte 비율 및 HSP-90β 유전자 발현율은 공히 토착코니시종이 가장 높았으며, 토착로드종이 가장 낮게 나타났다. 이러한 결과들은 토착로드종이 스트레스에 저항성이 높고, 토착코니시종이 스트레스에 가장 민감하게 반응함을 의미한다. 이상의 결과들을 종합할 때, 토착코니시종은 한국형 토종 육용 품종으로 개량함이 바람직하고, 토착레그혼종은 한국형 토종 난용 품종으로 개량하는 것이 바람직할 것으로 사료된다. 더불어 토착로드종은 양호한 생산능력과 뛰어난 강건성을 기반으로 한국형 토종닭 종계 모계통으로 활용하는 것이 바람직하리라 생각되고, 재래황갈종은 우수한 육질을 바탕으로 차별화 된 고급육질형 토종닭 품종으로 개량하는 것이 바람직하리라 사료된다.

• 생명과학회지
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• 제18권6호
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• pp.796-803
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• 2008

알츠하이머 질환은 신경퇴행성질환으로 노령인구에서 뿐만 아니라 $30{\sim}60$세 사이에서도 상염색체성우성형으로 발생하여 사회문제로 대두되고 있으며 발병기전도 명확하게 규명되지 않은 상태이다. 따라서 이 연구에서는 hAPP695sw 돌연변이를 neuron-specific enolase (NSE) 유전자의 프로모터 조절 하에 연결시킨 융합 유전자(pNSE/APP695sw fusion gene)를 과 발현시킨 알츠하이머 질환 모델생쥐를 대상으로 16주간 지구성 운동에 따른 알츠하이머 질환 모델생쥐의 인지능력의 변화와 주병변인 $A{\beta}-42$ 단백질과 함께 GLUT-1, BDNF, HSP-70 단백질의 발현량을 분석하였다. 그 결과 지구성 운동은 APPsw 알츠하이머 질환 모델생쥐의 인지능력을 개선시키는데 긍정적인 영향을 미친 것으로 나타났으며 이러한 인지능력의 개선은 알츠하이머 질환의 주 병변인 뇌의 $A{\beta}-42$ 감소뿐만 아니라 BDNF, GLUT-1과 HSP-70 단백질의 발현 증가와 관련이 있음을 확인하였다. 따라서 지구성 운동은 약물 처치 이외에 알츠하이머 질환을 예방하거나 지연시킬 수 있는 전략적인 방법으로 활용할 수 있음을 알 수 있다.