scholarly journals Allosteric Inhibition of the IRE1α RNase Preserves Cell Viability and Function during Endoplasmic Reticulum Stress

Cell ◽  
2014 ◽  
Vol 158 (3) ◽  
pp. 534-548 ◽  
Author(s):  
Rajarshi Ghosh ◽  
Likun Wang ◽  
Eric S. Wang ◽  
B. Gayani K. Perera ◽  
Aeid Igbaria ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Allosteric Inhibition ◽  
And Function

scholarly journals Effects of endoplasmic reticulum stress on the autophagy, apoptosis, and chemotherapy resistance of human breast cancer cells by regulating the PI3K/AKT/mTOR signaling pathway

Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769756 ◽  
Author(s):  
Jia-Teng Zhong ◽  
Jian Yu ◽  
Hai-Jun Wang ◽  
Yu Shi ◽  
Tie-Suo Zhao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Human Breast Cancer ◽  
Chemotherapy Resistance ◽  
Mtor Signaling Pathway ◽  
Human Breast ◽  
Diphenyltetrazolium Bromide ◽  
Mcf 7

Nowadays, although chemotherapy is an established therapy for breast cancer, the molecular mechanisms of chemotherapy resistance in breast cancer remain poorly understood. This study aims to explore the effects of endoplasmic reticulum stress on autophagy, apoptosis, and chemotherapy resistance in human breast cancer cells by regulating PI3K/AKT/mTOR signaling pathway. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect the cell viability of six human breast cancer cell lines (MCF-7, ZR-75-30, T47D, MDA-MB-435s, MDA-MB-453, and MDA-MB-231) treated with tunicamycin (5 µM), after which MCF-7 cells were selected for further experiment. Then, MCF-7 cells were divided into the control (without any treatment), tunicamycin (8 µ), BEZ235 (5 µ), and tunicamycin + BEZ235 groups. Cell viability of each group was testified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Western blotting was applied to determine the expressions of endoplasmic reticulum stress and PI3K/AKT/mTOR pathway–related proteins and autophagy- and apoptosis-related proteins. Monodansylcadaverine and Annexin V–fluorescein isothiocyanate/propidium iodide staining were used for determination of cell autophagy and apoptosis. Furthermore, MCF-7 cells were divided into the control (without any treatment), tunicamycin (5 µM), cisplatin (16 µM), cisplatin (16 µM) + BEZ235 (5 µM), tunicamycin (5 µM) + cisplatin (16 µM), and tunicamycin (5 µM) + cisplatin (16 µM) + BEZ235 groups. Cell viability and apoptosis were also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Annexin V–fluorescein isothiocyanate/propidium iodide staining. In MCF-7 cells treated with tunicamycin, cell viability decreased significantly, but PEAK, eIF2, and CHOP were upregulated markedly and p-PI3K, p-AKT, and p-MTOR were downregulated in dose- and time-dependent manners. In the tunicamycin + BEZ235 group, the cell viability was lower and the apoptosis rate was higher than those of the control and monotherapy groups. Compared with the cisplatin group, the tunicamycin + cisplatin group showed a relatively higher growth inhibition rate; the growth inhibition rate substantially increased in the tunicamycin + cisplatin + BEZ235 group than the tunicamycin + cisplatin group. The apoptosis rate was highest in tunicamycin + cisplatin + BEZ235 group, followed by tunicamycin + cisplatin group and then cisplatin group. Our study provide evidence that endoplasmic reticulum stress activated by tunicamycin could promote breast cancer cell autophagy and apoptosis and enhance chemosensitivity of MCF-7 cells by inhibiting the PI3K/AKT/mTOR signaling pathway.

scholarly journals Endoplasmic Reticulum Stress Is Involved in Baicalin Protection on Chondrocytes From Patients With Osteoarthritis

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581881063 ◽  
Author(s):  
Jiangang Cao ◽  
Yu Zhang ◽  
Tianyi Wang ◽  
Bo Li
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Er Stress ◽  
Messenger Rna ◽  
Cell Counting ◽  
Protective Effects ◽  
Gene Expressions ◽  
Protein Levels

Osteoarthritis (OA) affects elderly population worldwide and endoplasmic reticulum (ER) stress is known to be positively correlated with OA development. Previous reports prove the cytoprotective effects of baicalin on chondrocytes, whereas the mechanisms are hardly reported. Hence, we aimed to investigate the links between OA, ER stress, and baicalin. Chondrocytes from patients with OA were subjected to H2O2 treatment with or without baicalin pretreatment, and cell viability was assessed via Cell Counting Kit-8. Messenger RNA (mRNA) amounts of apoptosis-related genes (Bax, Bcl-2, and Caspase-3), extracellular matrix (ECM)-related genes (Collange I, Collange II, Aggrecan, and Sox9) and ER stress hallmarks (binding immunoglobulin protein [BiP] C/EBP homologous protein [CHOP]) were evaluated via quantitative real-time PCR. Bax, Bcl-2, BiP, and CHOP protein levels were analyzed via Western blot. Baicalin suppressed the changes in cell viability and apoptosis-related gene expressions caused by H2O2. Reactive oxygen species and glutathione/oxidized glutathione assay showed that H2O2 enhanced oxidative stress. Baicalin suppressed H2O2-induced downregulation of mRNA expression of ECM-related genes. Moreover, baicalin reduced H2O2-stimulated increase in oxidative stress and the expression of ER stress hallmarks. Endoplasmic reticulum stress inducer abolished the protective activities, whereas ER stress inhibitor did not exhibit extra protective effects. Baicalin pretreatment protected patient-derived chondrocytes from H2O2 through ER stress inhibition.

scholarly journals Localization and function in endoplasmic reticulum stress tolerance of ERdj3, a new member of Hsp40 family protein

2004 ◽  
Vol 9 (3) ◽  
pp. 253 ◽  
Author(s):  
Katsuya Nakanishi ◽  
Kenjiro Kamiguchi ◽  
Toshihiko Torigoe ◽  
Chika Nabeta ◽  
Yoshihiko Hirohashi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Stress Tolerance ◽  
Family Protein ◽  
And Function

scholarly journals ABCC10-Mediated Oxaliplatin Resistance in Colorectal Cancer Was Alleviated by Intense Endoplasmic Reticulum Stress (ERS) / IRE1α

2021 ◽  
Author(s):  
Xiaohui Liu ◽  
Hong Chen ◽  
Haimei Sun ◽  
Xiaoxia Guo ◽  
Bo Wu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
High Performance ◽  
Tumor Development ◽  
The Cancer Genome Atlas ◽  
Cell Counting ◽  
Promoting Effect ◽  
Knock Down

Abstract Background: Oxaliplatin resistance is a challenge in treating colorectal cancer (CRC) patients, contributory to the failure in chemotherapy. However, the mechanism of Oxaliplatin resistance has not been completely elucidated. In this study, we explored the key molecule involved in the Oxaliplatin resistance, which could be a candidate therapeutic target to attenuate chemo-resistance in CRC cells.Methods: Microarray screening, western blot and qPCR on clinic CRC samples were conducted to select the target gene ABCC10. The Oncomine Oncology Database and the Cancer Genome Atlas (TCGA) data were analyzed to figure out the correlation between the clinical manifestation and ABCC10. ABCC10 knock-down in CRC cells was conducted to identify its role in the Oxaliplatin resistance. Cell counting kit-8 (CCK-8) assay was conducted to identify the CRC cell viability and Oxaliplatin IC50. Flow cytometry was conducted to detect the cell apoptosis exposed to Oxaliplatin. The intracellular Oxaliplatin accumulation was measured by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS).Results: ABCC10 transporter was correlated with CRC relapse and metastasis, indicating a CRC-promoting effect of ABCC10. In ABCC10 knock-down CRC cells the Oxaliplatin sensitivity was significantly elevated due to an increase of intracellular Oxaliplatin accumulation resulted from the diminished drug efflux. We next explored a strategy to inhibit ABCC10 in CRC cells, paying a special interest in the endoplasmic reticulum stress (ERS) / unfolded protein response (UPR) that plays a dual role in tumor development. We found that the CRC cell viability was profoundly decreased and the pro-apoptotic factor CHOP and apoptosis were increased by the intense ERS/UPR instead of the inhibited and mild ERS/UPR. Significantly, the Oxaliplatin sensitivity of CRC cells was enhanced in response to the intense ERS, which was blocked by inhibiting IRE1α branch of UPR. Finally, we figured out that the intense ERS/UPR down-regulated ABCC10 via regulated IRE1-dependent decay (RIDD) activity. Conclusion: Oxaliplatin was a substrate of ABCC10. The intense ERS/IRE1α elicited anti-CRC effects through down-regulating ABCC10 so as to increase Oxaliplatin sensitivity, in addition to inducing CHOP. We suggested that introduction of intense ERS/UPR could be a promising strategy to restore chemo-sensitivity when used in combination with Oxaliplatin or other chemotherapeutic drugs pumped out by ABCC10.

scholarly journals CHOP Regulates Endoplasmic Reticulum Stress-Mediated Hepatoxicity Induced by Monocrotaline

2021 ◽  
Vol 12 ◽  
Author(s):  
Yazhou Guo ◽  
Chen Yang ◽  
Rong Guo ◽  
Ruijie Huang ◽  
Yongxia Su ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Liver Injury ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Er Stress ◽  
Pyrrolizidine Alkaloid ◽  
Annexin V ◽  
Rat Hepatocytes ◽  
Primary Rat Hepatocytes ◽  
Related Proteins

Monocrotaline (MCT), a pyrrolizidine alkaloid, is the major toxin in Crotalaria, which causes cell apoptosis in humans and animals. It has been reported that the liver is a vulnerable target of MCT. However, the exact molecular mechanism of the interaction between endoplasmic reticulum (ER) stress and liver injury induced by MCT is still unclear. In this study, the cytotoxicity of MCT on primary rat hepatocytes was analyzed by a CCK-8 assay and Annexin V-FITC/PI assay. Protein expression was detected by western blotting and immunofluorescence staining. As a result, MCT significantly decreased the cell viability and mediated the apoptosis of primary rat hepatocytes. Meanwhile, MCT could also induce ER stress in hepatocytes, indicated by the expression of ER stress-related proteins, including GRP78, p-IRE1α, ATF6, p-eIF2α, ATF4, and CHOP. Pretreatment with 4-PBA, an inhibitor of ER stress, or knockdown of CHOP by siRNA could partly enhance cell viability and relieve the apoptosis. Our findings indicate that ER stress is involved in the hepatotoxicity induced by MCT, and CHOP plays an important role in this process.

scholarly journals Human Genetic Disorders Resulting in Systemic Selenoprotein Deficiency

2021 ◽  
Vol 22 (23) ◽  
pp. 12927
Author(s):  
Erik Schoenmakers ◽  
Krishna Chatterjee
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Genetic Disorders ◽  
Cerebral Atrophy ◽  
Serum Selenium ◽  
Neurological Phenotype ◽  
Serum Selenium Levels ◽  
Ongoing Surveillance ◽  
And Function ◽  
Human Genetic Disorders

Selenium, a trace element fundamental to human health, is incorporated as the amino acid selenocysteine (Sec) into more than 25 proteins, referred to as selenoproteins. Human mutations in SECISBP2, SEPSECS and TRU-TCA1-1, three genes essential in the selenocysteine incorporation pathway, affect the expression of most if not all selenoproteins. Systemic selenoprotein deficiency results in a complex, multifactorial disorder, reflecting loss of selenoprotein function in specific tissues and/or long-term impaired selenoenzyme-mediated defence against oxidative and endoplasmic reticulum stress. SEPSECS mutations are associated with a predominantly neurological phenotype with progressive cerebello-cerebral atrophy. Selenoprotein deficiency due to SECISBP2 and TRU-TCA1-1 defects are characterized by abnormal circulating thyroid hormones due to lack of Sec-containing deiodinases, low serum selenium levels (low SELENOP, GPX3), with additional features (myopathy due to low SELENON; photosensitivity, hearing loss, increased adipose mass and function due to reduced antioxidant and endoplasmic reticulum stress defence) in SECISBP2 cases. Antioxidant therapy ameliorates oxidative damage in cells and tissues of patients, but its longer term benefits remain undefined. Ongoing surveillance of patients enables ascertainment of additional phenotypes which may provide further insights into the role of selenoproteins in human biological processes.

scholarly journals Inhibitory effect of quercetin on titanium particle induced endoplasmic reticulum stress related apoptosis and in vivo osteolysis

2017 ◽  
Vol 37 (4) ◽  
Author(s):  
Laibo Zhang ◽  
Zhoubin Tian ◽  
Wei Li ◽  
Xianquan Wang ◽  
Zhentao Man ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Inflammatory Cytokines ◽  
Orthopedic Implants ◽  
Osteoclast Formation ◽  
Raw264.7 Cells ◽  
Tartrate Resistant Acid Phosphatase ◽  
Raw264.7 Macrophages

Wear particle induced periprosthetic osteolysis is the main cause of aseptic loosening of orthopedic implants. The aim of the present study is to determine the protective effect of quercetin (QUE) against titanium (Ti) particle induced endoplasmic reticulum stress (ERS) related apoptosis and osteolysis. In the present study, RAW264.7 cells were pretreated with different concentrations (40, 80, and 160 μmol/l) of QUE for 30 min and then treated with Ti particle (5 mg/ml) for 24 h. Cell viability and apoptosis were determined using MTT assay and Annexin V-FITC Apoptosis Detection Kit, respectively. Protein and mRNA expressions of ERS-related genes were examined by Western blot and real-time PCR, respectively. The release of inflammatory cytokines was detected by ELISA. Then, a mouse calvarial osteolysis model was established. Histological sections of calvaria were stained with Hematoxylin-Eosin (H&E) or tartrate-resistant acid phosphatase (TRAP). The results showed that Ti particle reduced cell viability and induced apoptosis in RAW264.7 macrophages. The cytotoxic effects of Ti particle were dramatically inhibited by QUE pretreatment. Interestingly, we found that QUE also significantly reduced Ti particle induced up-regulation of the expression levels of protein kinase RNA-like ER kinase (PERK), inositol-requiring enzyme-1 (IRE1), glucose-regulated protein (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, and caspase-3 and enhanced the down-regulation of Bcl-2. In addition, QUE decreased Ti particle-induced inflammatory cytokines release from RAW264.7 cells. Moreover, treatment with QUE markedly decreased osteoclast number. In a mouse calvarial osteolysis model, QUE inhibited Ti particle induced osteolysis in vivo by inhibiting osteoclast formation and expressions of ERS-related genes. In conclusion, QUE can protect RAW264.7 cells from Ti particle induced ERS-related apoptosis and suppress calvarial osteolysis in vivo.

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