• 대한의생명과학회지
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• 제26권1호
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• pp.37-41
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• 2020

The hemolymph of Korean rhinoceros Allomyrina dichotoma consists of blood and lymph in which various kinds of proteins function physiologically. We have previously demonstrated that A. dichotoma hemolymph has the potential to treatment and prevent diabetes through activating transcription factor 3-gene (ATF3) regulation. In this study, we investigate the expression of Kruppel-like factor 4 (KLF4) in A. dichotoma hemolymph-treated INS-1 pancreatic β-cells. The new findings show that A. dichotoma hemolymph, which upregulates KLF4 gene expression in a dose-dependent and time-dependent manner. In addition, hemolymph combine with mild endoplasmic reticulum (ER) stress, which also differentially regulates KLF4 gene expression. These results may provide insights to KLF4 gene-related disease therapies through KLF4 gene regulation.

• Journal of Plant Biology
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• 제30권4호
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• pp.225-247
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• 1987

Meiosis and postmeiotic mitosis in Boletus rubinellus were examined ultrastructurally. Meriosis occurred at the apex of the basidium. A sausage-shaped spindle pole body(SPB) was observed along with the presence of synaptonemal complexes during pachytene and a diglobular SPB was present on late pachytene or diplotene nuclei. During metaphase I, the monoglobular SPB at the spindle pole was surrounded bya membrane and the nuclear enveloope was discontinuous. At anaphase I, the chromosomes became better defined and formed a central spindle. The nucleolus was extruded from the nucleus. During anaphase I, the SPB was excluded from the chromosomal region by a membrane and both poles were fully separated to opposite sides of the basidial wall. In meiosis II, the two nuclei divided synchronously and the spindles were parallel. The spindles were smaller than in meiosis I, while the SPB was approximately the same size as that of the similar stage in meiosis I. During anaphasetelophase II, the SPB was surrounded by a cap of endoplasmic reticulum (ER) that delimited it from the spindle. The postmeiotic interphase nuclei migrated to the mid-region of the basidium before migration to the spores. The SPB at this stage was diglobular. A postmeiotic mitosis occurred within the basidiospore, and the plane of the spindle was obique to the long axis of the spore. The spindle and SPB were smaller than at meiosis I and there were fewer nonchromosomal microtubules. At anaphase, the nucleolus was present inside the nuclear envelope but lateral to the spindle.

• 대한의생명과학회지
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• 제27권3호
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• pp.170-176
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• 2021

Thapsigargin (TG), a sarco/endoplasmic reticulum (ER) Ca²⁺-ATPase (SERCA) inhibitor, has been widely used as an agonist for platelet aggregation for decades. In this study, we investigated the effect of TG on the release of lactate dehydrogenase (LDH) for platelets and elucidated its mechanism. Platelet LDH release and platelet aggregation were increased by TG treatment; 1,000 nM of TG induced the complete lysis of platelets. Other agonists such as collagen (2.5 ㎍/mL), thrombin (0.1 U/mL), and ADP (10 mM) did not induce significant platelet LDH release despite platelet aggregation. Finally, we investigated the effects of pharmacological inhibitors on TG-induced platelet aggregation and LDH release. SP600125, a JNK inhibitor, and LY294002, a PI-3K inhibitor, inhibited TG-induced platelet LDH release but not platelet aggregation. Forskolin, an adenylyl cyclase activator, also inhibited LDH release without affecting platelet aggregation by TG. These results suggest that the TG-induced platelet aggregation was accompanied by LDH release but regulated by a different signaling pathway.

• BMB Reports
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• 제56권11호
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• pp.612-617
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• 2023

Pleiotropic regulator 1 (PLRG1), a highly conserved element in the spliceosome, can form a NineTeen Complex (NTC) with Prp19, SPF27, and CDC5L. This complex plays crucial roles in both pre-mRNA splicing and DNA repair processes. Here, we provide evidence that PLRG1 has a multifaceted impact on cancer cell proliferation. Comparing its expression levels in cancer and normal cells, we observed that PLRG1 was upregulated in various tumor tissues and cell lines. Knockdown of PLRG1 resulted in tumor-specific cell death. Depletion of PLRG1 had notable effects, including mitotic arrest, microtubule instability, endoplasmic reticulum (ER) stress, and accumulation of autophagy, ultimately culminating in apoptosis. Our results also demonstrated that PLRG1 downregulation contributed to DNA damage in cancer cells, which we confirmed through experimental validation as DNA repair impairment. Interestingly, when PLRG1 was decreased in normal cells, it induced G1 arrest as a self-protective mechanism, distinguishing it from effects observed in cancer cells. These results highlight multifaceted impacts of PLRG1 in cancer and underscore its potential as a novel anti-cancer strategy by selectively targeting cancer cells.

• Molecules and Cells
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• 제27권5호
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• pp.577-582
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• 2009

The development of a high-throughput functional genomic screening provides a novel and expeditious approach in identifying critical genes involved in specific biological processes. Here we describe a cell-based cDNA screening system to identify the transcription activators of BiP, an endoplasmic reticulum (ER) chaperone protein. BiP promoter contains the ER stress element which is commonly present in the genes involved in unfolded protein response (UPR) that regulates protein secretion in cells. Therefore, the positive regulators of BiP may also be utilized to improve the recombinant protein production through modulation of UPR. Four BiP activators, including human UDP-glucose:glycoprotein glucosyltransferase 1 (HUGT1), are identified by the cDNA screening. Overexpression of HUGT1 leads to a significant increase in the production of recombinant erythropoietin, interferon ${\gamma}$, and monoclonal antibody in HEK293 cells. Our results demonstrate that the cDNA screening for BiP activators may be effective to identify the novel BiP regulators and HUGT1 may serve as an ideal target gene for improving the recombinant protein production in mammalian cells.

• 농업과학연구
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• 제43권4호
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• pp.575-580
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• 2016

This study was performed to determine whether supplementation of tauroursodeoxycholic acid (TUDCA), an endoplasmic reticulum (ER) stress inhibitor, during vitrified cryopreservation enhances the development of frozen mouse embryos. Mouse 8-cell stage embryos were collected and exposed to a cryoprotectant solution containing TUDCA or TM (tunicamycin, an ER stress inhibitor) at room temperature and stored in liquid nitrogen following vitrification. The final concentration of TUDCA or TM was $50{\mu}M$. The survival and development rates of mouse 8-cell stage embryos exposed to TUDCA- or TM-containing solutions at room temperature or stored in liquid nitrogen following vitrification were measured. There were no significant differences in survival rate and blastocyst formation rate among control, TUDCA, and TM groups after embryos were exposed to vitrification solutions at RT. When mouse 8-cell stage embryos were treated with TUDCA or TM and then stored in liquid nitrogen, the survival rates of control and TUDCA groups were significantly higher than for the TM group. Blastocyst formation rate of the TUDCA group following in vitro culture was significantly higher than that in control or TM groups. The TM group showed a lower (p < 0.05) blastocyst formation rate than the other two groups. Our results indicate that TUDCA supplementation during cryopreservation of mouse embryos could enhance their development capacity.

• Applied Microscopy
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• 제33권3호
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• pp.205-214
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• 2003

본 연구의 목적은 스쿠알렌이 납 중독에 대해 효과가 있는 지를 관찰하고자 하였다. 건강한 ICR계 생쥐를 사용하였다. 납을 복강 투여한 후 SOD와 간 조직의 미세구조를 관찰하였다. 실험군은 다음과 같다. Group 1은 납을 복강 투여한 후 스쿠알렌을 처치하지 않은 대조군, Group 2는 납을 복강 투여한 후 스쿠알렌을 처치한 군으로 각 실험군당 생쥐 10마리를 사용하였다. 실험 결과는 다음과 같다. SOD 측정 결과 대조군은 정상군에 비해 수치가 훨씬 낮게 나타났지만, 스쿠알렌을 처치한 군에서는 정상군에 비해 낮지만, 대조군 보다 수치가 높게 나타남을 관찰할 수 있었다(P<0.05). 간 조직의 미세구조에의 경우 납 단독 처치군의 경우사립체의 팽대와 rER은 팽대 및 절단된 상태가 관찰되었으나, 스쿠알렌을 처치한 군에서는 납 단독 처치군에 비해 손상 정도가 덜하였다. 본 연구를 통해 스쿠알렌이 납 중독에 의한 간장 조직의 손상 회복에 대해 효과가 있는 것으로 생각되어진다.

• Applied Microscopy
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• 제36권2호
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• pp.57-72
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• 2006

본 연구는 급성 납 독성에 대한 활성탄의 방어효과를 알아보기 위하여 시도되었다. 30g 내외의 생쥐를 대상으로 대조군, 납(60mg/kg)투여군, 납 투여후 활성탄(40mg/kg)투여군으로 구분하여 구강투여 한 후 신장 손상억제 효과를 알아보기 위하여 생화학적 및 조직학적 실험을 실시하였다. 혈액 중 blood urea nitrogen(BUN) 그리고 creatinine (Cre)의 활성도는 활성탄 투여군이 납 투여군보다 감소되었다. 전자현미경적 관찰 결과, 신장의 근위세뇨관에서 납 투여군은 미세융모의 소실이 나타나고, 핵이 함입되어 불규칙해졌으며, 미토콘드리아는 팽대되고, 그 수가 감소하였다. rER의 수조가 확장되고 공포화 현상이 관찰되었으며 리보솜의 탈락이 관찰되었다. 활성탄 투여군은 핵은 거의 원형의 상태이고, 다수의 미토콘드리아가 관찰되었으며, rER은 리보솜이 부착된 상태로 관찰되었다. 이상과 같은 결과, 활성탄이 납 중독된 생쥐에서 납을 흡착시킴으로서 손상된 신장에 보호 효과가 있는 것으로 사료된다.

• BMB Reports
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• 제51권10호
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• pp.538-543
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• 2018

Pancreatic beta cell destruction and dysfunction induced by cytokines is a major cause of type 1 diabetes. Paraoxonase 1 (PON1), an arylesterase with antioxidant activity, has been shown to play an important role in preventing the development of diabetes in transgenic mice. However, no studies have examined the anti-diabetic effect of PON1 delivered to beta cells using protein transduction. In this study, we expressed the cell-permeable PON1 fused with PEP-1 protein transduction domain (PEP-1-PON1) to investigate whether transduced PEP-1-PON1 protects beta cells against cytokine-induced cytotoxicity. PEP-1-PON1 was effectively delivered to INS-1 cells and prevented cytokine-induced cell destruction in a dose-dependent manner. Transduced PEP-1-PON1 significantly reduced the levels of reactive oxygen species (ROS) and nitric oxide (NO), DNA fragmentation, and expression of inflammatory mediators, endoplasmic reticulum (ER) stress proteins, and apoptosis-related proteins in cytokine-treated cells. Moreover, transduced PEP-1-PON1 restored the decrease in basal and glucose-stimulated insulin secretion induced by cytokines. These data indicate that PEP-1-PON1 protects beta cells from cytokine-induced cytotoxicity by alleviating oxidative/nitrosative stress, ER stress, and inflammation. Thus, PEP-1-mediated PON1 transduction might be an effective method to reduce the extent of destruction and dysfunction of pancreatic beta cells in autoimmune diabetes.

• Molecules and Cells
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• 제38권5호
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• pp.457-465
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• 2015

The 15-kDa selenoprotein (Sep15) is a selenoprotein residing in the lumen of the endoplasmic reticulum (ER) and implicated in quality control of protein folding. Herein, we established an inducible RNAi cell line that targets Sep15 mRNA in Chang liver cells. RNAi-induced Sep15 deficiency led to inhibition of cell proliferation, whereas cell growth was resumed after removal of the knockdown inducer. Sep15-deficient cells were arrested at the G1 phase by upregulating p21 and p27, and these cells were also characterized by ER stress. In addition, Sep15 deficiency led to the relocation of focal adhesions to the periphery of the cell basement and to the decrease of the migratory and invasive ability. All these changes were reversible depending on Sep15 status. Rescuing the knockdown state by expressing a silent mutant Sep15 mRNA that is resistant to siRNA also reversed the phenotypic changes. Our results suggest that SEP15 plays important roles in the regulation of the G1 phase during the cell cycle as well as in cell motility in Chang liver cells, and that this selenoprotein offers a novel functional link between the cell cycle and cell motility.