• 동의생리병리학회지
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• 제22권6호
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• pp.1462-1469
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• 2008

The purpose of the study was to confirm what effect HRHDT treatment had on cell extinction by damage of endoplasmic reticulum induced to PC-12 cell damage by glucose deprivation. The study confirmed what effect it had on forming the condition of glucose deprivation within a culture fluid of PC-12 cell and on a nerve cell's survival rates and tested whether HRHDT could prevent extinction of PC-12 cell by glucose deprivation. Also, the study confirmed what effect HRHDT treatment had on the emitted quantity of LDH by glucose deprivation. To examine PC-12 cell's behavioral change under the condition of glucose deprivation and a protective effect of HRHDT on the change, the study observed PC-12 cell's behavioral change with a microscope. Also, the study confirmed density of calcium ion within cells followed by a culture time in the condition of glucose deprivation with FACS and confirmed what effect HRHDT treatment had on the above density of calcium ion within cells. Finally, the study carried out the western blot and confirmed what effect HRHDT treatment had on revelation of GRP 78 and CHOP protein and a segmental type of aspase 12. In this study, HRHDT rescued PC-12 cells from glucose deprivation-induced cell death. HRHDT also prevents the LDH release, Ca++ accumulation, and morphological change, which was associated with the ER stress. Furthermore, HRHDT reduced the expression of ER chaperone (Grp78 and CHOP) proteins by glucose deprivation in PC-12 cells. These results suggest that HRHDT might provide a useful therapeutic strategy in treatment of the neurodegenerative diseases caused by glucose deprivation injuries.

• Molecules and Cells
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• 제41권5호
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• pp.401-412
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• 2018

Oxymatrine (OMT) often used in treatment for chronic hepatitis B virus infection in clinic. However, OMT-induced liver injury has been reported. In this study, we aim to investigate the possible mechanism of OMT-induced hepatotoxicity in human normal liver cells (L02). Exposed cells to OMT, the cell viability was decreased and apoptosis rate increased, the intracellular markers of oxidative stress were changed. Simultaneously, OMT altered apoptotic related proteins levels, including Bcl-2, Bax and pro-caspase-8/-9/-3. In addition, OMT enhanced the protein levels of endoplasmic reticulum (ER) stress makers (GRP78/Bip, CHOP, and cleaved-Caspase-4) and phosphorylation of c-Jun N-terminal kinase (p-JNK), as well as the mRNA levels of GRP78/Bip, CHOP, caspase-4, and ER stress sensors (IREI, ATF6, and PERK). Pre-treatment with Z-VAD-fmk, JNK inhibitor SP600125 and N-acetyl-l-cysteine (NAC), a ROS scavenger, partly improved the survival rates and restored OMT-induced cellular damage, and reduced caspase-3 cleavage. SP600125 or NAC reduced OMT-induced p-JNK and NAC significantly lowered caspase-4. Furthermore, 4-PBA, the ER stress inhibitor, weakened inhibitory effect of OMT on cells, on the contrary, TM worsen. 4-PBA also reduced the levels of p-JNK and cleaved-caspase-3 proteins. Therefore, OMT-induced injury in L02 cells was related to ROS mediated p-JNK and ER stress induction. Antioxidant, by inhibition of p-JNK or ER stress, may be a feasible method to alleviate OMT-induced liver injury.

• Biomolecules & Therapeutics
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• 제30권3호
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• pp.265-273
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• 2022

Resistance to chemotherapeutic drugs is a significant problem in the treatment of colorectal cancer, resulting in low response rates and decreased survival. Recent studies have shown that shikonin, a naphthoquinone derivative, promotes apoptosis in colon cancer cells and cisplatin-resistant ovarian cells, raising the possibility that this compound may be effective in drug-resistant colorectal cancer. The aim of this study was to characterize the molecular mechanisms underpinning shikonin-induced apoptosis, with a focus on endoplasmic reticulum (ER) stress, in a 5-fluorouracil-resistant colorectal cancer cell line, SNU-C5/5-FUR. Our results showed that shikonin significantly increased the proportion of sub-G₁ cells and DNA fragmentation and that shikonin-induced apoptosis is mediated by mitochondrial Ca²⁺ accumulation. Shikonin treatment also increased the expression of ER-related proteins, such as glucose regulatory protein 78 (GRP78), phospho-protein kinase RNA-like ER kinase (PERK), phospho-eukaryotic initiation factor 2 (eIF2α), phospho-phosphoinositol-requiring protein-1 (IRE1), spliced X-box-binding protein-1 (XBP-1), cleaved caspase-12, and C/EBP-homologous protein (CHOP). In addition, siRNA-mediated knockdown of CHOP attenuated shikonin-induced apoptosis, as did the ER stress inhibitor TUDCA. These data suggest that ER stress is a key factor mediating the cytotoxic effect of shikonin in SNU-C5/5-FUR cells. Our findings provide an evidence for a mechanism in which ER stress leads to apoptosis in shikonin-treated SNU-C5/5-FUR cells. Our study provides evidence to support further investigations on shikonin as a therapeutic option for 5-fluorouracil-resistant colorectal cancer.

• 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.

• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.83-94
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• 2010

Chinese fir (Latin name: Cunninghaimia lanceolata) is one of the major commercial coniferous trees. Most of Chinese fir forests are managed in successive rotation sites, which lead productivity to decline. Autotoxicity is the important reason for soil degradation of Chinese fir plantation, especially, phenolic acids are considered as the major allelopathic toxins which induce autotoxicity in Chinese fir rotation stands. We performed here proteomic approach to investigate the response of proteins in Chinese fir leaves to salicylic acid. The tube plantlets of Chinese fir clone were treated with 120 mg/L salicylic acid for 1, 3 and 5th day. 2-DE, coupled with MALDI-TOF-TOF/MS, was used to separate and identify the responsive proteins. We found 12, 7, and 12 candidate protein spots that were up- or down-regulated by at least 2.5 fold after 1, 3, and 5th day of the stress, respectively. Of these protein spots, 16 spots were identified successfully. According to the putative physiological functions, these proteins were categorized into five classes (1) the proteins involved in protein stability and folding, including 26S proteome, Grp78, Hsp70, Hsp90 and PPIase; (2) the protein involved in photosynthesis and respiration, including OEC 33 kDa subunit, GAPDH; (3) the protein related to cell endurance to acid, F-ATPase; (4) the protein related to cytoskeleton, tubulin; (5) the protein related to protein translation: prolyl-tRNA synthetase. These results give new insights into autotoxic substance stress response in Chinese fir leaves and provide preliminary footprints for further studies on the molecular signal mechanisms induced by the stress.

• 생명과학회지
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• 제25권8호
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• pp.947-952
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• 2015

Par-4는 종양 억제 유전자로 암세포 선택적으로 세포사멸을 증진하는 기능을 가진다. Par-4 유전자는 nuclear localization sequences (NLS), leucine zipper (LZ), nuclear export sequence (NES), selective for apoptosis in cancer cells (SAC)의 네 가지 도메인을 가지고 있다. 이 중에서도 SAC 도메인이 Par-4에 의한 세포사멸에 중요한 역할을 하며, 이러한 Par-4의 활성화는 세포 내 경로와 세포 외 경로로 나누어진다. 세포질 내의 Par-4는 핵 내로 이동하여 NF-κB 매개의 세포 성장 경로를 억제하고 세포 밖으로 분비된 Par-4는 세포 표면에 존재하는 수용체인 GRP78과 결합하여 세포 사멸을 유도한다. 따라서 Par-4의 발현을 증가시키는 물질에 의한 세포 사멸뿐만 아니라 암세포에서 발현이 낮은 Par-4의 과발현을 통하여 세포사멸 민감화가 증진된다. 따라서 Par-4는 암 치료의 강력한 표적으로의 가능성을 가지고 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4249-4254
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• 2013

Background: Parafibromin is a protein encoded by the HRPT2 (hyperparathyroidism 2) oncosuppressor gene and its down-regulated expression is involved in pathogenesis of parathyroid, breast, gastric and colorectal carcinomas. This study aimed to clarify the effects of parafibromin expression on the phenotypes and relevant mechanisms of DLD-1 colon carcinoma cells. Methods: DLD-1 cells transfected with a parafibromin-expressing plasmid were subjected to examination of phenotype, including proliferation, differentiation, apoptosis, migration and invasion. Phenotype-related proteins were measured by Western blot. Parafibromin and ki-67 expression was detected by immunohistochemistry on tissue microarrays. Results: The transfectants showed higher proliferation by CCK-8, better differentiation by electron microscopy and ALP activity and more apoptotic resistance to cisplatin by DNA fragmentation than controls. There was no difference in early apoptosis by annexin V, capase-3 activity, migration and invasion between DLD-1 cells and their transfectants. Ectopic parafibromin expression resulted in down-regulated expression of smad4, MEKK, GRP94, GRP78, $GSK3{\beta}$-ser9, and Caspase-9. However, no difference was detectable in caspase-12 and -8 expression. A positive relationship was noted between parafibromin and ki-67 expression in colorectal carcinoma. Conclusions: Parafibromin overexpression could promote cell proliferation, apoptotic resistance, and differentiation of DLD-1 cells.

• BMB Reports
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• 제51권8호
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• pp.400-405
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• 2018

Chronic stress induces neuronal cell death, which can cause nervous system disorders including Parkinson's disease and Alzheimer's disease. In this study, we evaluated the neuroprotective effects of Clematis terniflora extract (CTE) against corticosterone-induced apoptosis in rat pheochromocytoma (PC12) cells, and also investigated the underlying molecular mechanisms. At concentrations of 300 and $500{\mu}g/ml$, CTE significantly decreased apoptotic cell death and mitochondrial damage induced by $200{\mu}M$ corticosterone. CTE decreased the expression levels of endoplasmic reticulum (ER) stress proteins GRP78, GADD153, and mitochondrial damage-related protein BAD, suggesting that it downregulates ER stress evoked by corticosterone. Furthermore, our results suggested that these protective effects were mediated by the upregulation of p-AKT and p-ERK1/2, which are involved in cell survival signaling. Collectively, our results indicate that CTE can lessen neural damage caused by chronic stress.

• BMB Reports
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• 제42권11호
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• pp.719-724
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• 2009

Recent studies have revealed that endoplasmic reticulum (ER) disturbance is involved in the pathophysiology of neurodegenerative disorders, contributing to the activation of the ER stress-mediated apoptotic pathway. Therefore, we investigated here the molecular mechanisms underlying the ER-mitochondria axis, focusing on calcium as a potential mediator of cell death signals. Using NT2 cells treated with brefeldin A or tunicamycin, we observed that ER stress induces changes in the mitochondrial function, impairing mitochondrial membrane potential and distressing mitochondrial respiratory chain complex Moreover, stress stimuli at ER level evoked calcium fluxes between ER and mitochondria. Under these conditions, ER stress activated the unfolded protein response by an overexpression of GRP78, and also caspase-4 and-2, both involved upstream of caspase-9. Our findings show that ER and mitochondria interconnection plays a prominent role in the induction of neuronal cell death under particular stress circumstances.

• Molecules and Cells
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• 제25권1호
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• pp.43-49
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• 2008

Cancer Osaka thyroid, also known as Tpl-2 (Cot) is a member of the MAP3K kinase family and plays a key role in the regulation of the immune response to pro-inflammatory stimuli such as lipopolysaccharide (LPS) and tumour necrosis $factor-{\alpha}$ ($TNF-{\alpha}$). A series of Cot constructs with an N-terminal 6xHis tag were transiently expressed in HEK293 cells: $Cot_{130-399}$ (kinase domain), $Cot_{1-388}$ (N-terminal and kinase do-mains), $Cot_{1-413}$, $Cot_{1-438}$ (containing a putative PEST sequence), $Cot_{1-457}$ (containing both PEST and degron sequences) and $Cot_{1-467}$ (full-length protein). These Cot proteins were pulled down using an anti-6xHis antibody and separated by 2D electrophoresis. The gels were silver-stained and 21 proteins were detected that did not appear, or had substantially reduced intensity, in the control sample. Three of these were identified by MS and MS/MS analysis as Hsp90, Hsp70 and Grp78. Hsp90 appeared to bind to the kinase domain of Cot and this interaction was further investigated using co-immuno-precipitation with both overexpressed Cot in HEK293 cells and endogenous Cot in Hela cells.