scholarly journals Combined treatment with bortezomib plus bafilomycin A1 enhances the cytocidal effect and induces endoplasmic reticulum stress in U266 myeloma cells: Crosstalk among proteasome, autophagy-lysosome and ER stress

2011 ◽  
Vol 38 (3) ◽  
Author(s):  
Miyazawa
Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4058-4058
Author(s):  
Keisuke Miyazawa ◽  
Shota Moriya ◽  
Tomohiro Kawaguchi ◽  
Tadashi Ohtomo ◽  
Xiao-Fang Che ◽  
...  

Abstract Abstract 4058 Bortezomib (BZ), a first line 26S proteasome inhibitor, has been shown to be effective for the treatment of multiple myeloma (MM). Since IκBα is a substrate of the proteasome, the initial rationale for use of BZ in MM was inhibition of NF-kB activity. However, our data revealed that BZ rather activates NF-κB activity in MM cells as recently reported by others (Hideshima T et al. Blood 2009). BZ showed the more potent cytocidal effect along with caspase activation in MM cell lines as compared with various leukemia and cancer cell lines. BZ also induces autophagy as well as ER stress in various kinds of cell lines. However, autophagy induction in response to BZ requires much longer exposure time as compared with the cells treated with other autophagy inducers such as imatinib mesylate. Several recent reports demonstrated that the selective autophagy of the ubiquitinated proteins via p62/SQSTM1and NBR1 proteins, which can simultaneously bind both ubiquitin and autophagy-specific ubiquitin-like modifier, LC3. Therefore, polyubiquitinated proteins are engulfed into autophagosomes via p62-LC3 binding and subsequently transferred to lysosome and degraded (Kirkin V et al. Mol. Cell. 2009). We therefore speculated that inhibition of autophagy as an alternative protein degradation system may increase the accumulation of misfolded proteins and ER stress. This may result in enhancement of cytocidal effect of BZ. Unexpectedly, inhibition of autophagy by using 3-methyadenine (MA), shRNA-mediated inhibition of LC3 levels or complete knockdown of atg5 using a Tet-off atg5-/- MEF system all attenuated BZ-induced cytotoxic effect. This suggests that induction of autophagy in response to BZ appears to function as leading to cell death but not for cytoprotection. However, combined treatment with BZ plus bafilomycin A1 (BAF), an inhibitor of vacuolar ATPase, showed the synergistic cytotoxicity as compared with the cells treated with either BZ or BAF alone. BAF inhibited autophagy at the late stage and induced ER stress as well as BZ. However, kinetics of CHOP (GADD153) and the chaperon BiP (GRP78) expressions in response to BAF were competently different from those by BZ; BZ induced CHOP/GRP78 within 8 hr while BAF induced these ER stress markers after more than 48 hr exposure. In order to synchronize ER stress, we pre-treated MM cell line, U266 cells with BAF for 48 hr then followed with BZ. The sequential treatment with BAF and BZ showed the further enhanced cytocidal effect as comparing with the simultaneous combination of BAZ plus BZ in U266 cells. Our data suggest that ER stress, but not inhibition of NF-kB, is involved in BZ-induced cytotoxicity in MM cells, and also suggest the tight linkage among autophagy, proteasome, and ER stress. Controlling these relations and kinetics may provide the novel strategy for enhancing the cytotocidal effect for cancer therapy including MM-treatment. Disclosures: No relevant conflicts of interest to declare.


2019 ◽  
Vol 19 (5) ◽  
pp. 665-675 ◽  
Author(s):  
Wenjiao Shi ◽  
Zhixin Guo ◽  
Ruixia Yuan

Background and Objective: This study investigated whether rapamycin has a protective effect on the testis of diabetic rats by regulating autophagy, endoplasmic reticulum stress, and oxidative stress. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups: control, diabetic, and diabetic treated with rapamycin, which received gavage of rapamycin (2mg.kg-1.d-1) after induction of diabetes. Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65mg.Kg-1). All rats were sacrificed at the termination after 8 weeks of rapamycin treatment. The testicular pathological changes were determined by hematoxylin and eosin staining. The protein or mRNA expression of autophagy-related proteins (Beclin1, microtubule-associated protein light chain 3 (LC3), p62), ER stress marked proteins (CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), caspase-12), oxidative stress-related proteins (p22phox, nuclear factor erythroid2-related factor 2 (Nrf2)) and apoptosis-related proteins (Bax, B cell lymphoma-2 (Bcl-2)) were assayed by western blot or real-time fluorescence quantitative PCR. Results: There were significant pathological changes in the testes of diabetic rats. The expression of Beclin1, LC3, Nrf2, Bcl-2 were significantly decreased and p62, CHOP, caspase12, p22phox, and Bax were notably increased in the testis of diabetic rats (P <0.05). However, rapamycin treatment for 8 weeks significantly reversed the above changes in the testis of diabetic rats (P <0.05). Conclusion: Rapamycin appears to produce a protective effect on the testes of diabetic rats by inducing the expression of autophagy and inhibiting the expression of ER-stress, oxidative stress, and apoptosis.


2021 ◽  
Vol 22 (9) ◽  
pp. 4538
Author(s):  
Helena Kratochvílová ◽  
Miloš Mráz ◽  
Barbora J. Kasperová ◽  
Daniel Hlaváček ◽  
Jakub Mahrík ◽  
...  

The aim of our study was to analyze mitochondrial and endoplasmic reticulum (ER) gene expression profiles in subcutaneous (SAT) and epicardial (EAT) adipose tissue, skeletal muscle, and myocardium in patients with and without CAD undergoing elective cardiac surgery. Thirty-eight patients, 27 with (CAD group) and 11 without CAD (noCAD group), undergoing coronary artery bypass grafting and/or valvular surgery were included in the study. EAT, SAT, intercostal skeletal muscle, and right atrium tissue and blood samples were collected at the start and end of surgery; mRNA expression of selected mitochondrial and ER stress genes was assessed using qRT-PCR. The presence of CAD was associated with decreased mRNA expression of most of the investigated mitochondrial respiratory chain genes in EAT, while no such changes were seen in SAT or other tissues. In contrast, the expression of ER stress genes did not differ between the CAD and noCAD groups in almost any tissue. Cardiac surgery further augmented mitochondrial dysfunction in EAT. In our study, CAD was associated with decreased expression of mitochondrial, but not endoplasmic reticulum stress genes in EAT. These changes may contribute to the acceleration of coronary atherosclerosis.


2021 ◽  
Author(s):  
Viorica Liebe Lastun ◽  
Matthew Freeman

In metazoans, the architecture of the endoplasmic reticulum (ER) differs between cell types, and undergoes major changes through the cell cycle and according to physiological needs. Although much is known about how the different ER morphologies are generated and maintained, especially the ER tubules, how context dependent changes in ER shape and distribution are regulated and the factors involved are less characterized. Here, we show that RHBDL4, an ER-resident rhomboid protease, modulates the shape and distribution of the ER, especially under conditions that require rapid changes in the ER sheet distribution, including ER stress. RHBDL4 interacts with CLIMP-63, a protein involved in ER sheet stabilisation, and with the cytoskeleton. Mice lacking RHBDL4 are sensitive to ER stress and develop liver steatosis, a phenotype associated with unresolved ER stress. Our data introduce a new physiological role of RHBDL4 and also imply that this function does not require its enzymatic activity.


mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Oanh H. Pham ◽  
Bokyung Lee ◽  
Jasmine Labuda ◽  
A. Marijke Keestra-Gounder ◽  
Mariana X. Byndloss ◽  
...  

ABSTRACT The inflammatory response to Chlamydia infection is likely to be multifactorial and involve a variety of ligand-dependent and -independent recognition pathways. We previously reported the presence of NOD1/NOD2-dependent endoplasmic reticulum (ER) stress-induced inflammation during Chlamydia muridarum infection in vitro, but the relevance of this finding to an in vivo context is unclear. Here, we examined the ER stress response to in vivo Chlamydia infection. The induction of interleukin 6 (IL-6) production after systemic Chlamydia infection correlated with expression of ER stress response genes. Furthermore, when tauroursodeoxycholate (TUDCA) was used to inhibit the ER stress response, an increased bacterial burden was detected, suggesting that ER stress-driven inflammation can contribute to systemic bacterial clearance. Mice lacking both NOD1 and NOD2 or RIP2 exhibited slightly higher systemic bacterial burdens after infection with Chlamydia. Overall, these data suggest a model where RIP2 and NOD1/NOD2 proteins link ER stress responses with the induction of Chlamydia-specific inflammatory responses. IMPORTANCE Understanding the initiation of the inflammatory response during Chlamydia infection is of public health importance given the impact of this disease on young women in the United States. Many young women are chronically infected with Chlamydia but are asymptomatic and therefore do not seek treatment, leaving them at risk of long-term reproductive harm due to inflammation in response to infection. Our manuscript explores the role of the endoplasmic reticulum stress response pathway initiated by an innate receptor in the development of this inflammation.


2019 ◽  
Vol 54 (5) ◽  
pp. 465-471 ◽  
Author(s):  
Sheng Wang ◽  
Jiajie Luan ◽  
Xiongwen Lv

ICR mice received ethanol (5 g/kg) by intragastric administration, showing an increase in hepatosomatic index and ALT. These effects were accompanied by increased expression of ER stress-related proteins and exosomal miR-122, PBA intervention can attenuate these changes induced by ethanol provides a potential therapy strategy for acute alcoholic liver injury.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Wen-Shan Xu ◽  
Yuan-Ye Dang ◽  
Jia-Jie Guo ◽  
Guo-Sheng Wu ◽  
Jin-Jian Lu ◽  
...  

Furanodiene (FUR) is a natural terpenoid isolated fromCurcumae Rhizoma, a well-known Chinese medicinal herb that presents antiproliferation activities in several cancer cell lines. In this study, we demonstrated that FUR concentration dependently inhibits the cell proliferation of A549, NIH-H1299, and 95-D lung cancer cells.β-elemene, another terpenoid isolated fromCurcumae Rhizoma, exhibited weaker antiproliferative effects in A549 and NIH-H1299 cells and activities similar to FUR in 95-D cells. FUR significantly inhibited colony formation in A549 and 95-D cells and upregulated both the mRNA and protein expression levels of binding immunoglobulin protein (BIP) and C/EBP homologous protein (CHOP), indicating that endoplasmic reticulum (ER) stress is induced. FUR treatment led to the accumulation of CHOP in the nucleus, which further confirms induction of ER stress. Furthermore, combined treatment of FUR with paclitaxel showed significant synergetic activities in NIH-H1299 and 95-D cells, suggesting its potential roles in combination therapy. These findings provide a basis for the further study of the anticancer effectsin vivoand the internal mechanisms of FUR.


2018 ◽  
Vol 40 (2) ◽  
pp. 175-188 ◽  
Author(s):  
Michael J. Hylin ◽  
Ryan C. Holden ◽  
Aidan C. Smith ◽  
Aric F. Logsdon ◽  
Rabia Qaiser ◽  
...  

The leading cause of death in the juvenile population is trauma, and in particular neurotrauma. The juvenile brain response to neurotrauma is not completely understood. Endoplasmic reticulum (ER) stress has been shown to contribute to injury expansion and behavioral deficits in adult rodents and furthermore has been seen in adult postmortem human brains diagnosed with chronic traumatic encephalopathy. Whether endoplasmic reticulum stress is increased in juveniles with traumatic brain injury (TBI) is poorly delineated. We investigated this important topic using a juvenile rat controlled cortical impact (CCI) model. We proposed that ER stress would be significantly increased in juvenile rats following TBI and that this would correlate with behavioral deficits using a juvenile rat model. A juvenile rat (postnatal day 28) CCI model was used. Binding immunoglobulin protein (BiP) and C/EBP homologous protein (CHOP) were measured at 4 h in the ipsilateral pericontusion cortex. Hypoxia-inducible factor (HIF)-1α was measured at 48 h and tau kinase measured at 1 week and 30 days. At 4 h following injury, BiP and CHOP (markers of ER stress) were significantly elevated in rats exposed to TBI. We also found that HIF-1α was significantly upregulated 48 h following TBI showing delayed hypoxia. The early ER stress activation was additionally asso­ciated with the activation of a known tau kinase, glycogen synthase kinase-3β (GSK-3β), by 1 week. Tau oligomers measured by R23 were significantly increased by 30 days following TBI. The biochemical changes following TBI were associated with increased impulsive-like or anti-anxiety behavior measured with the elevated plus maze, deficits in short-term memory measured with novel object recognition, and deficits in spatial memory measured with the Morris water maze in juvenile rats exposed to TBI. These results show that ER stress was increased early in juvenile rats exposed to TBI, that these rats developed tau oligomers over the course of 30 days, and that they had significant short-term and spatial memory deficits following injury.


2016 ◽  
Vol 28 (2) ◽  
pp. 187
Author(s):  
C. Ahn ◽  
D. Lee ◽  
K. P. Kim ◽  
M. H. Lee ◽  
E.-B. Jeung

Endoplasmic reticulum (ER) regulates calcium ion concentration as a reservoir in the cell. ER stress is a cellular stress response related to the endoplasmic reticulum. At the initial stage of ER stress, ER tries to restore normal function by halting protein translation, degrading misfolded proteins, and increasing production of chaperones involved in protein folding. If ER fails to restore ER stress, ER stress can lead cells to apoptosis. To study the signaling between ER stress and calcium channels under ER-stressed circumstances, we designed a hypoxia-induced diabetic model. Nine-week-old male mice were chosen, maintained under hypoxic condition under 10% O2, 5% CO2 for 10 days, and the expression of ER stress markers and calcium channel gene expression were examined by real-time PCR. By maintaining hypoxic condition, the mice showed high glucose levels. Under this diabetic condition, in pancreatic beta cells, ER stress markers were elevated. This tendency showed an increase in calbindin-D9k KO mice. Chaperones such as calreticulin and calnexin were decreased, but in calbindin-D9k KO mice chaperone calnexin was not decreased. Interestingly, the calbindin-D9k KO normoxia mice showed increased glucose level compared with wild-type normoxia mice. Also, calnexin expression of pancreas was decreased in calbindin-D9k KO normoxia mice. This result indicates that pancreas cells were under endoplasmic reticulum stress. Taken together, calbindin may play an important role in endoplasmic reticulum stress in pancreas. This work was supported by the National Research Foundation of Korea (NRF) grant of Korean government (MEST) (No. 2013-010514).


Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581881063 ◽  
Author(s):  
Jiangang Cao ◽  
Yu Zhang ◽  
Tianyi Wang ◽  
Bo Li

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.


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