• Journal of Animal Science and Technology
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• 제66권1호
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• pp.204-218
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• 2024

Elsholtzia fruticosa (EF) is present in tropical regions throughout South Asian countries as well as the Himalayas. Although it has been used as a traditional medicine to treat digestive, respiratory, and inflammatory issues, its effect on preadipocyte differentiation is unknown. In this study, we examined the effects of a methanol extract prepared from EF on the differentiation of 3T3-L1 preadipocytes. Cell differentiation was assessed by microscopic observation and oil-red O staining. The expression of adipogenic and lipogenic genes, including PPARγ and C/EBPα, was measured by western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR), to provide insight into adipogenesis and lipogenesis mechanisms. The results indicated that EF promotes the differentiation of 3T3-L1 preadipocytes, with elevated lipid accumulation occurring in a concentration-dependent manner without apparent cytotoxicity. EF enhances the expression of adipogenic and lipogenic genes, including PPARγ, FABP4, adiponectin, and FAS, at the mRNA and protein levels. The effect of EF was more pronounced during the early and middle stages of 3T3-L1 cell differentiation. Treatment with EF decreased C/EBP homologous protein (CHOP) mRNA and protein levels, while increasing C/EBPα and PPARγ expression. Treatment with EF resulted in the upregulation of cyclin E and CDK2 gene expression within 24 h, followed by a decrease at 48 h, demonstrating the early-stage impact of EF. A concomitant increase in cyclin-D1 levels was observed compared with untreated cells, indicating that EF modulates lipogenic and adipogenic genes through intricate mechanisms involving CHOP and cell cycle pathways. In summary, EF induces the differentiation of 3T3-L1 preadipocytes by increasing the expression of adipogenic and lipogenic genes, possibly through CHOP and cell cycle-dependent mechanisms.

• Journal of Chest Surgery
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• 제45권1호
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• pp.1-10
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• 2012

Background: ${\alpha}$-Lipoic acid (${\alpha}$-LA) has been studied as an anticancer agent as well as a therapeutic agent for diabetes and obesity. We performed this study to evaluate the anticancer effects and mechanisms of ${\alpha}$-LA in a lung cancer cell line, A549. Materials and Methods: ${\alpha}$-LA-induced apoptosis of A549 cells was detected by fluorescence-activated cell sorting analysis and a DNA fragmentation assay. Expression of apoptosis-related genes was analyzed by western blot and reverse transcription.polymerase chain reaction analyses. Results: ${\alpha}$-LA induced apoptosis and DNA fragmentation in A549 cells in a dose- and time-dependent manner. ${\alpha}$-LA increased caspase activity and the degradation of poly (ADP-ribose) polymerase. It induced expression of endoplasmic reticulum (ER) stress-related genes, such as glucose-regulated protein 78, C/EBP-homologous protein, and the short form of X-box binding protein-1, and decreased expression of the anti-apoptotic protein, X-linked inhibitor of apoptosis protein. Reactive oxygen species (ROS) production was induced by ${\alpha}$-LA, and the antioxidant N-acetyl-L-cysteine decreased the ${\alpha}$-LA-induced increase in expression of apoptosis and ER stress-related proteins. Conclusion: ${\alpha}$-LA induced ER stress-mediated apoptosis in A549 cells via ROS. ${\alpha}$-LA may therefore be clinically useful for treating lung cancer.

• Molecules and Cells
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• 제45권9호
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• pp.622-630
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• 2022

Colorectal cancer (CRC) has a high mortality rate among cancers worldwide. To reduce this mortality rate, chemotherapy (5-fluorouracil, oxaliplatin, and irinotecan) or targeted therapy (bevacizumab, cetuximab, and panitumumab) has been used to treat CRC. However, due to various side effects and poor responses to CRC treatment, novel therapeutic targets for drug development are needed. In this study, we identified the overexpression of EHMT1 in CRC using RNA sequencing (RNA-seq) data derived from TCGA, and we observed that knocking down EHMT1 expression suppressed cell growth by inducing cell apoptosis in CRC cell lines. In Gene Ontology (GO) term analysis using RNA-seq data, apoptosis-related terms were enriched after EHMT1 knockdown. Moreover, we identified the CHOP gene as a direct target of EHMT1 using a ChIP (chromatin immunoprecipitation) assay with an anti-histone 3 lysine 9 dimethylation (H3K9me2) antibody. Finally, after cotransfection with siEHMT1 and siCHOP, we again confirmed that CHOP-mediated cell apoptosis was induced by EHMT1 knockdown. Our findings reveal that EHMT1 plays a key role in regulating CRC cell apoptosis, suggesting that EHMT1 may be a therapeutic target for the development of cancer inhibitors.

• 환경생물
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• 제26권3호
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• pp.214-219
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• 2008

Changes in stress-associated biomolecules can be used as an important criterion for assessing the levels of environmental pollution because living organisms demonstrate contamination-stimulated stress responses. This study was conducted to determine the environmental status of Masan-Jinhae Bay, Korea, and its effects on marine organisms by investigating the endoplasmic reticulum (ER) dysfunction in the organs of the flat fish, Limanda yokohamae. ER dysfunction was evaluated via Western blot analysis of the ER stress proteins, immunoglobulin heavy chain binding protein (BiP) and C/EBP-homologous protein (CHOP), and the ER stress-associated protein caspase-12. The results showed that the amount of BiP and CHOP immunoreactivity in the flat fish from the bay area was much greater than that from the Gangneung, as a reference site. Similar to the ER stress proteins, the immunoreactivity of caspase-12 was also found to be elevated in the bay area when compared with that of Gangneung. These data suggest that the environmental status of Masan-Jinhae Bay induces the ER stress response, which is able to lead to phenotypic changes in marine organisms including fish.

• 대한한의학방제학회지
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• 제26권4호
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• pp.307-318
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• 2018

Objectives : Endoplasmic reticulum (ER) stress designates cellular responses to the accumulation of misfolded and unfolded proteins in ER, which is related to a variety of liver diseases. Present study investigated the inhibitory effects of Litsea japonica flesh water extract (LJE) aganist ER stress. Methods : After HepG2 cells were pretreated with LJE and subsequently exposed to tunicamycin (Tm) or thapsigargin (Tg), expression of C/EBP homologous protein (CHOP), glucose regulated protein 78 kDa (GRP78), asparagine synthetase (ASNS), and endoplasmic reticulum DnaJ homologue 4 (ERDJ4) were determined by immunoblot and real-time PCR analysis. Three canonical signaling pathways in response to ER stress were examined to explore molecular mechanisms involved. Results : Pretreatment of 1 mg/mL LJE inhibited Tm- or Tg-induced CHOP expression, while L. japonica fruit water extract did not. In addition, LJE decreased the levels of GRP78, ASNS, and ERDJ4 mRNA by Tm. Moreover, phosphorylations of eukaryotic translation initiation factor $2{\alpha}$ and inositol-requiring enzyme 1, expression of nuclear form of activating transcription factor $6{\alpha}$, and transactivation of ER stress response element- and unfolded protein response element-harboring luciferase activities were inhibited by LJE pretreatment. Conclusions : Present results suggest that LJE would be a candidate to prevent or treat ER stress-mediated liver injuries.

• 디지털융복합연구
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• 제17권8호
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• pp.265-270
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• 2019

성장하는 증거는 소포체 (ER) 스트레스의 매개 세포 사멸이 알츠하이머병을 포함한 신경 퇴행성 질환의 병리학적 발달에 중요한 역할을 한다. 로디올라 사크라(ERS)의 에탄올 추출물은 ER 스트레스 유도제인 호모시스테인(Hcy)세포 사멸과 ER 스트레스의 신경 neuro -2A 세포를 보호할 수 있는지를 조사한다. 뉴런 세포에서 Hcy는 MTT 분석에 의해 확인된 바와 같이 세포 생존 가능성은 현저히 감소시켰고, Annexin V 양성 세포의 사멸을 유도했다. ERS로 전처리한 Hcy세포 생존력 및 세포 사멸 손실은 약화되었으며, Hcy는 C/EBP 상 동성 단백질과 78-kDa 포도당 조절 단백질의 발현 및 X-box 결합 단백질 -1 (xbp1) mRNA의 접합에 스트레스를 유도했다. ESR은 Hcy에 의해 유도된 xbp-1 mRNA 접합, GRP78 및 CHOP 세포를 감소시켜 Hcy-induced ER 스트레스 및 세포 사멸에 대한 보호를 나타내며, Western blotting 분석에 heme oxygenase-1의 발현 및 HO-1 효소 활성 억제는 hemin에 의한 세포 사멸을 감소시키는 등 신경 퇴행성 질환에 치료적 가치를 보여준다.

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.345-351
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• 2011

High glucose leads to physio/pathological alterations in diabetes patients. We investigated collagen production in human gingival cells that were cultured in high concentrations of glucose. Collagen synthesis and secretion were increased when the cells were exposed to high concentrations of glucose. We examined endoplasmic reticulum (ER) stress response because glucose metabolism is related to ER functional status. An ER stress response including the expression of glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), inositol requiring enzyme alpha (IRE-$1{\alpha}$) and phosphoreukaryotic initiation factor alpha (p-eIF-$2{\alpha}$) was activated in the presence of high glucose. Activating transcription factor 4 (ATF-4), a downstream protein of p-eIF-$2{\alpha}$ as well as a transcription factor for collagen, was also phosphorylated and translocalized into the nucleus. The chemical chaperone 4-PBA inhibited the ER stress response and ATF-4 phosphorylation as well as nuclear translocation. Our results suggest that high concentrations of glucose-induced collagen are linked to ER stress and the associated phosphorylation and nuclear translocation of ATF-4.

• Genomics & Informatics
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• 제11권4호
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• pp.245-253
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• 2013

A radioresistant cell line was established by fractionated ionizing radiation (IR) and assessed by a clonogenic assay, flow cytometry, and Western blot analysis, as well as zymography and a wound healing assay. Microarray was performed to profile global expression and to search for differentially expressed genes (DEGs) in response to IR. H460R cells demonstrated increased cell scattering and acidic vesicular organelles compared with parental cells. Concomitantly, H460R cells showed characteristics of increased migration and matrix metalloproteinase activity. In addition, H460R cells were resistant to IR, exhibiting reduced expression levels of ionizing responsive proteins (p-p53 and ${\gamma}$-H2AX); apoptosis-related molecules, such as cleaved poly(ADP ribose) polymerase; and endoplasmic reticulum stress-related molecules, such as glucose-regulated protein (GRP78) and C/EBP-homologous protein compared with parental cells, whereas the expression of anti-apoptotic X-linked inhibitor of apoptosis protein was increased. Among DEGs, syntrophin beta 2 (SNTB2) significantly increased in H460R cells in response to IR. Knockdown of SNTB2 by siRNA was more sensitive than the control after IR exposure in H460, H460R, and H1299 cells. Our study suggests that H460R cells have differential properties, including cell morphology, potential for metastasis, and resistance to IR, compared with parental cells. In addition, SNTB2 may play an important role in radioresistance. H460R cells could be helpful in in vitro systems for elucidating the molecular mechanisms of and discovering drugs to overcome radioresistance in lung cancer therapy.

• Molecules and Cells
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• 제42권3호
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• pp.252-261
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• 2019

The omega-3 fatty acid docosahexaenoic acid (DHA) is known to induce apoptosis and cell cycle arrest via the induction of reactive oxygen species (ROS) production and endoplasmic reticulum (ER) stress in many types of cancers. However, the roles of DHA in drug-resistant cancer cells have not been elucidated. In this study, we investigated the effects of DHA in cisplatin-resistant gastric cancer SNU-601/cis2 cells. DHA was found to induce ROS-dependent apoptosis in these cells. The inositol 1,4,5-triphosphate receptor ($IP_3R$) blocker 2-aminoethyl diphenylboninate (2-APB) reduced DHA-induced ROS production, consequently reducing apoptosis. We also found that G-protein-coupled receptor 120 (GPR120), a receptor of long-chain fatty acids, is expressed in SNU-601/cis2 cells, and the knockdown of GPR120 using specific shRNAs alleviated DHA-mediated ROS production and apoptosis. GPR120 knockdown reduced the expression of ER stress response genes, similar to the case for the pre-treatment of the cells with N-acetyl-L-cysteine (NAC), an ROS scavenger, or 2-APB. Indeed, the knockdown of C/EBP homologous protein (CHOP), a transcription factor that functions under ER stress conditions, markedly reduced DHA-mediated apoptosis, indicating that CHOP plays an essential role in the anti-cancer activity of DHA. These results suggest that GPR120 mediates DHA-induced apoptosis by regulating $IP_3R$, ROS, and ER stress levels in cisplatin-resistant cancer cells, and that GPR120 is an effective chemotherapeutic target for cisplatin resistance.

• Nutrition Research and Practice
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• 제11권6호
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• pp.445-451
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• 2017

BACKGROUND/OBJECTIVES: Endoplasmic reticulum (ER) stress is positively associated with atherosclerosis via elevating macrophage cell death and plaque formation, in which oxidative stress plays a pivotal role. Antioxidative, lipid-lowering, and anti-atherogenic effects of kimchi, a Korean fermented vegetable, have been established, wherein capsaicin, ascorbic acid, quercetin, 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid, and lactic acids were identified. In this study, mechanisms of action of kimchi methanol extracts (KME) on fatty streak formation via suppression of ER stress and apoptosis in aorta were examined in low-density lipoprotein receptor knockout mice. MATERIALS AND METHODS: Mice fed a high cholesterol diet with an oral administration of KME (KME group, $200 mg{\cdot}kg-bw^{-1}{\cdot}day^{-1}$) or distilled water (control group) for 8 weeks (n = 20 for group). Plasma lipid and oxidative stress levels were evaluated. Protein expression was measured by western blot assay. Fatty streak lesion size and the degree of apoptosis were examined in the aorta. RESULTS: Compared to the control group, in the KME group, plasma lipids levels were decreased and oxidative stress was alleviated (P < 0.05). Protein expression levels of nuclear factor (erythroid-derived 2)-like 2-mediated antioxidants in aorta were increased whereas those for ER stress markers, glucose regulated protein 78, phospho-protein kinase RNA-like ER kinase, phospho-eukaryotic initiation factor 2 subunit ${\alpha}$, X-box binding protein 1, and C/EBP homologous protein were decreased in the KME group (P < 0.05). Moreover, apoptosis was suppressed via downregulation of phospho-c-Jun N-terminal kinase, bcl-2-associated X protein, caspases-9, and -3 with a concomitant upregulation of anti-apoptotic protein, B-cell lymphoma 2 (P < 0.05). Fatty streak lesion size was reduced and the degree of apoptosis was less severe in the KME group (P < 0.05). CONCLUSIONS: In conclusion, antioxidant activity of KME might prevent fatty streak formation through, in part, inhibition of ER stress and apoptosis in aortic sinus where macrophages are harbored.