Abstract 380: Aging Enhances Endoplasmic Reticulum Stress-Induced Apoptosis in Murine Macrophages

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Daniel R Goldstein ◽  
Yang Song
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Stress Proteins ◽  
Fluorescent Microscopy ◽  
Annexin V ◽  
Peritoneal Macrophages ◽  
Downstream Effector ◽  
Induced Apoptosis ◽  
Dependent Interaction

Introduction and hypothesis Aging enhances atherosclerosis for unclear reasons. As macrophage apoptosis and endoplasmic reticulum (ER) stress contribute to atherosclerosis, we examined if aging sensitizes these cells to apoptosis during ER stress. Methods and Results Peritoneal macrophages were isolated from young (aged 2-4 months) and aged (aged 16-18 months) mice, exposed to the ER stress inducer tunicamycin (TM) in vitro, and apoptosis was measured by Annexin V staining via fluorescent microscopy. We found that aged macrophages exhibited significantly more apoptosis than young macrophages (see Figure). We next measured key ER stress proteins in macrophages by Western blot to determine the underlying molecular pathways impacted by aging. With aging, we found reduced activation of inositol-requiring enzyme-1 (IRE1α), a key ER stress transducer. We next examined if augmenting activated IRE1α levels in aged macrophages reduced apoptosis during ER stress. We employed siRNA to knock down x-box binding protein 1 (XBP1), a downstream effector of IRE1α, which has been shown to induce feedback activation of IRE1α in hepatocytes. siRNA to XBP1 significantly reduced tunicamycin-induced cell apoptosis in aged macrophages from 26.1±0.408% to 5.48±1.38% (p<0.05) but not in young macrophages. Conclusions Our study has uncovered a novel, age-dependent interaction by which macrophages undergo apoptosis upon ER stress, and suggests that enhancing IRE1α activation will alleviate aging-augmented ER stress and subsequent apoptosis. This novel interaction may have important implications for the pathogenesis of atherosclerosis with aging.

scholarly journals The Coronavirus Spike Protein Induces Endoplasmic Reticulum Stress and Upregulation of Intracellular Chemokine mRNA Concentrations

2007 ◽  
Vol 81 (20) ◽  
pp. 10981-10990 ◽  
Author(s):  
Gijs A. Versteeg ◽  
Paula S. van de Nes ◽  
Peter J. Bredenbeek ◽  
Willy J. M. Spaan
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Stress Proteins ◽  
Hepatitis Virus ◽  
Spike Protein ◽  
Simultaneous Increase ◽  
Mrna Transcription ◽  
Mrna Induction ◽  
Infected Cells

ABSTRACT Murine hepatitis virus (MHV) and severe acute respiratory syndrome (SARS) coronavirus (CoV) are two of the best-studied representatives of the family Coronaviridae. During CoV infection, numerous cytokines and chemokines are induced in vitro and in vivo. Human interleukin 8 and its mouse functional counterpart, CXCL2, are early-expressed chemokines. Here we show that SARS-CoV and MHV induce endoplasmic reticulum (ER) stress and Cxcl2 mRNA transcription during infection in vitro. Expression of the viral spike protein significantly induced ER stress and Cxcl2 mRNA upregulation, while expression of the other structural genes did not. Additional experiments with UV-inactivated virus, cell-cell fusion-blocking antibodies, and an MHV mutant with a defect in spike protein maturation demonstrated that spike-host interactions in the ER are responsible for the induction of ER stress and subsequent Cxcl2 mRNA transcription. Despite significant increases in levels of Cxcl2 mRNA and functional nucleus-to-cytoplasm RNA transport, no CXCL2 protein was released into the medium from MHV-infected cells. Yet Sendai virus-infected cells showed substantial Cxcl2 mRNA induction and a simultaneous increase in levels of secreted CXCL2 protein. Our results demonstrate that expression of CoV spike proteins induces ER stress, which could subsequently trigger innate immune responses. However, at that point in infection, translation of host mRNA is already severely reduced in infected cells, preventing the synthesis of CXCL2 and ER stress proteins despite their increased mRNA concentrations.

scholarly journals Flow cytometry evaluation of HeLa S3 cell death induced by gamma-radiation

2004 ◽  
Vol 23 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Ana Niciforovic ◽  
Bozidarka Zaric ◽  
Aleksandra Dakic ◽  
Nevena Tisma ◽  
Marija Radojcic
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Radiation Dose ◽  
Gamma Radiation ◽  
Fluorescent Microscopy ◽  
Annexin V ◽  
Hela S3 ◽  
Induced Apoptosis ◽  
60Co Gamma Radiation

In this study we followed the effects of radiation on human uterin cervix HeLa S3 cells viability, morphology and DNA structure 2-96 hours after treatment with 2-10 Gy from 60Co gamma radiation source. Staining of cells with Annexin V-FITC and propidium iodide showed very low degree of radiation-induced apoptosis. The prevailing form of HeLa S3 cell death according to flow-cytometry, DNA fragmentation and fluorescent microscopy, was necrosis. The gamma-radiation dose necessary to induce 50% of necrosis (termed DD50) was twice higher compared to dose that induced 50% inhibition of cell proliferation (LD50). These in vitro data suggested, that the increase in radiation dose might eradicate tumor cells, rather than just control their proliferation and growth.

116 TAUROURSODEOXYCHOLIC ACID PREVENTS ENDOPLASMIC RETICULUM STRESS-INDUCED APOPTOSIS IN PREIMPLANTATION PIG EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 158
Author(s):  
J.-S. Kim ◽  
K.-S. Lee ◽  
B.-S. Song ◽  
J.-Y. Zhang ◽  
Y.-K. Choo ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Preimplantation Embryos ◽  
Control Group ◽  
Tauroursodeoxycholic Acid ◽  
Preimplantation Stage ◽  
Induced Apoptosis

Apoptosis is an important determinant for the normal development of preimplantation embryos in vitro. Recently, endoplasmic reticulum (ER) stress-mediated apoptosis has been extensively investigated in a wide variety of diseases. The efficient functioning of the ER is essential for most cellular activities and survival. Tauroursodeoxycholic acid (TUDCA), an endogenous bile acid, has been reported to attenuate ER stress-mediated cell death by interrupting classic pathways of apoptosis. Therefore, we explored the anti-apoptotic effect of TUDCA on ER stress-induced apoptosis in preimplantation porcine embryos. Also, TM (tunicamycin; an ER stress inducing chemical reagent) was used to investigate the effect of ER-stress on pig embryo development. After in vitro maturation and fertilization, presumptive porcine embryos were cultured in NCSU23 medium supplemented with 200 μ g mL–1 TUDCA or 1 μg mL–1 (TM) for 6 days at 39°C, 5% CO2 in air. All data were analyzed by using Duncan test of ANOVA by Statistical Analysis System (SAS). When treated with TM during culture, only 8.2% (8/97) of the embryos developed to the blastocyst stage compared with 27.4% (28/102) of the embryos in the control group (P < 0.05). We also confirmed that TM stimulates up-regulation of ER stress response genes, such as XBP-1 mRNA, and induces a high rate of apoptosis. Whereas the frequency of blastocyst formation in the TUDCA-treated group was increased compared with that in the control group (32.8%, 49/149 v. 22.2%, 32/144), P < 0.05). Furthermore, the blastocyst cell number was enhanced (30.6 v. 39.5) and apoptosis reduced (TUNEL positive nuclei number, 6.0 v. 3.2) by TUDCA treatment in pig embryos. As the result of real-time quantitative RT-PCR analysis, the expression of anti-apoptotic Bcl-xl gene was increased in the blastocyst stage by TUDCA treatment, whereas expression of pro-apoptotic Bax was decreased. In addition, we also confirmed that TUDCA decreases the rate of TM-induced apoptosis in preimplantation stage pig embryos. Our results indicate that TUDCA improves the developmental competence of porcine embryos by modulating the ER stress-induced apoptosis during preimplantation stage.

scholarly journals Prevention of glucocorticoid induced-apoptosis of osteoblasts and osteocytes by protecting against endoplasmic reticulum (ER) stress in vitro and in vivo in female mice

Bone ◽  
2015 ◽  
Vol 73 ◽  
pp. 60-68 ◽  
Author(s):  
Amy Y. Sato ◽  
Xiaolin Tu ◽  
Kevin A. McAndrews ◽  
Lilian I. Plotkin ◽  
Teresita Bellido
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Female Mice ◽  
Induced Apoptosis

The life span of short-lived plasma cells is partly determined by a block on activation of apoptotic caspases acting in combination with endoplasmic reticulum stress

Blood ◽  
2010 ◽  
Vol 116 (18) ◽  
pp. 3445-3455 ◽  
Author(s):  
Holger W. Auner ◽  
Christine Beham-Schmid ◽  
Niall Dillon ◽  
Pierangela Sabbattini
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Caspase 3 ◽  
Plasma Cells ◽  
Myeloma Cell ◽  
Immunoglobulin Secretion ◽  
Effector Caspase ◽  
Induced Apoptosis

Abstract Apoptosis of short-lived plasma cells after a few days of intense immunoglobulin secretion is critical for maintaining a controlled humoral immune response. The mechanisms that regulate this process are poorly understood. Here we report that the key apoptotic caspases, caspase-3 and caspase-9, become resistant to activation by apoptotic stimuli when B cells differentiate into short-lived plasma cells. As a consequence, apoptosis of most short-lived plasma cells in vitro and in vivo is effector caspase-independent. We also show that a triaspartic acid repeat that normally prevents activation of caspase-3 becomes stabilized in short-lived plasma cells and myeloma cell lines. The block on caspase activation occurs before the accumulation of intracellular immunoglobulins and a progressive rise in secretory stress in the endoplasmic reticulum (ER). Plasma cells show increased susceptibility to ER stress–induced apoptosis and activate the ER-associated caspase-12, which is required specifically for nuclear apoptotic events. In nonlymphoid cells that cannot activate effector caspases, programmed cell death is delayed in response to ER stress. These observations suggest that the block on activation of key apoptotic caspases has evolved in short-lived plasma cells to prolong survival under conditions of ER stress resulting from high-level immunoglobulin secretion.

scholarly journals Tauroursodeoxycholic acid prevents Burkholderia pseudomallei-induced endoplasmic reticulum stress and is protective during melioidosis in mice

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Siqi Yuan ◽  
Yao Fang ◽  
Mengling Tang ◽  
Zhiqiang Hu ◽  
Chenglong Rao ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Burkholderia Pseudomallei ◽  
Treatment Strategies ◽  
Effective Vaccine ◽  
Tauroursodeoxycholic Acid ◽  
Raw264.7 Macrophages ◽  
Induced Apoptosis

Abstract Background Burkholderia pseudomallei, a facultative intracellular bacterium, is the aetiological agent of melioidosis that is responsible for up to 40% sepsis-related mortality in epidemic areas. However, no effective vaccine is available currently, and the drug resistance is also a major problem in the treatment of melioidosis. Therefore, finding new clinical treatment strategies in melioidosis is extremely urgent. Results We demonstrated that tauroursodeoxycholic acid (TUDCA), a clinically available endoplasmic reticulum (ER) stress inhibitor, can promote B. pseudomallei clearance both in vivo and in vitro. In this study, we investigated the effects of TUDCA on the survival of melioidosis mice, and found that treatment with TUDCA significantly decreased intracellular survival of B. pseudomallei. Mechanistically, we found that B. pseudomallei induced apoptosis and activated IRE1 and PERK signaling ways of ER stress in RAW264.7 macrophages. TUDCA treatment could reduce B. pseudomallei-induced ER stress in vitro, and TUDCA is protective in vivo. Conclusion Taken together, our study has demonstrated that B. pseudomallei infection results in ER stress-induced apoptosis, and TUDCA enhances the clearance of B. pseudomallei by inhibiting ER stress-induced apoptosis both in vivo and in vitro, suggesting that TUDCA could be used as a potentially alternative treatment for melioidosis.

scholarly journals Gambogenic Acid Induces Endoplasmic Reticulum Stress in Colorectal Cancer via the Aurora A Pathway

2021 ◽  
Vol 9 ◽  
Author(s):  
Cheng Liu ◽  
Jiaxin Xu ◽  
Chenxu Guo ◽  
Xugang Chen ◽  
Chunmei Qian ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Aurora A ◽  
Eukaryotic Translation ◽  
Induced Apoptosis

Colorectal cancer (CRC) is one of the most common malignancies in the world and has a poor prognosis. In the present research, gambogenic acid (GNA), isolated from the traditional Chinese medicine gamboge, markedly induced apoptosis and inhibited the proliferation of CRC in vitro and in vivo. Furthermore, GNA triggered endoplasmic reticulum (ER) stress, which subsequently activated inositol-requiring enzyme (IRE) 1α and the eukaryotic translation initiation factor (eIF) 2α pathway. Pretreatment with salubrinal (an eIF2α inhibitor) rescued GNA-induced cell death. Furthermore, GNA downregulated the expression of Aurora A. The Aurora A inhibitor alisertib decreased ER stress. In human colorectal adenocarcinoma tissue, Aurora A was upregulated compared to normal colorectal epithelial nuclei. Furthermore, GNA ameliorated mouse colitis-associated cancer models. Our findings demonstrated that GNA significantly inhibited the proliferation of CRC through activation of ER stress by regulating Aurora A, which indicates the potential of GNA for preventing the progression of CRC.

Melatonin alleviates deoxynivalenol-induced apoptosis of human granulosa cells by reducing mutually accentuated FOXO1 and ER stress

2021 ◽  
Author(s):  
Rufeng Xue ◽  
Shuhang Li ◽  
Huijuan Zou ◽  
Dongmei Ji ◽  
Mingrong Lv ◽  
...  
Keyword(s):  
Er Stress ◽  
Granulosa Cells ◽  
Protective Effects ◽  
Human Granulosa Cells ◽  
Downstream Effector ◽  
Ros Accumulation ◽  
Additional Protection ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

Abstract Deoxynivalenol (DON) is one of the most prevalent Fusarium mycotoxins which cause detrimental effects on human and animal reproductive systems by inducing oxidative stress. Increasing evidence has suggested the potential roles of melatonin in protecting granulosa cells from oxidative injury, but the underlying mechanisms remain largely elusive. Here, we demonstrated that suppression of FOXO1 and endoplasmic reticulum (ER) stress was engaged in melatonin-mediated protection against oxidative damage in human granulosa cells upon DON exposure in vitro. DON induced excess reactive oxygen species (ROS) accumulation, cells viability loss, reduced estradiol-17β and progesterone production in human granulosa cells, whereas melatonin ameliorated these phenotypes. Next, we found that the protective effect of melatonin against apoptosis was via reducing ER stress because inhibition of ER stress displayed similar protective effects during DON treatment. Moreover, melatonin provided no additional protection when ER stress was inhibited. We further found that FOXO1 is a pivotal downstream effector of melatonin and ER stress in regulating DON-induced apoptosis in human granulosa cells. Blocking of FOXO1 reduced DON-induced cells death and FOXO1 activation could be suppressed by melatonin or ER stress inhibitor. However, melatonin failed to further restore cells viability in the presence of FOXO1 inhibitor. Collectively, our results reveal a new mechanism of melatonin in protecting against DON-induced apoptosis and dysfunction by suppressing ER stress and FOXO1 in human granulosa cells.

scholarly journals High Glucose-Induced Podocyte Injury Involves Activation of Mammalian Target of Rapamycin (mTOR)-Induced Endoplasmic Reticulum (ER) Stress

2018 ◽  
Vol 45 (6) ◽  
pp. 2431-2443 ◽  
Author(s):  
Jie Lei ◽  
Lei Zhao ◽  
Yujing Zhang ◽  
Yanfeng Wu ◽  
Yanbo Liu
Keyword(s):  
Endoplasmic Reticulum ◽  
Energy Consumption ◽  
Cytochrome C ◽  
Er Stress ◽  
High Glucose ◽  
Mammalian Target Of Rapamycin ◽  
Annexin V ◽  
Normal Glucose ◽  
Cellular Apoptosis ◽  
Induced Apoptosis

Background/Aims: The mechanisms by which high glucose (HG) results in podocyte damage remains unclear. We investigated the potential role of endoplasmic reticulum (ER) stress and mTOR signaling in HG injured podocyte. Methods: In cultured mouse podocytes, cellular apoptosis was assessed using FITC-Annexin V and propidium iodide staining followed by flow cytometry analysis. Apoptosis-related proteins as well as the ER stress and the mTOR signals were evaluated using immunoblot assay. Results: Compared to normal glucose (NG) and osmotic mannitol (MN) control, the percentage of apoptotic cells was increased significantly in HG-treated podocytes. The levels of CHOP, Grp78, phospho-PERKThr982, and caspase-12 were increased significantly following HG treatment. The downstream effects of ER stress were obtained in HG-treated podocytes, showing upregulation of Bax, Bak and cytochrome c, and downregulation of Bcl-2. HG-induced increase of cytochrome c, Bax and active caspase-3 was prevented by both ER inhibitor sodium 4-phenylbultyrate (PBA) and CHOP siRNA (siCHOP). PBA and CHOP knockdown remarkably decreased HG-induced apoptosis. In addition, the levels of phospho-mTORSer2448 and phospho- p70S6kThr389 as well as phospho-AMPKα (a sensor of energy consumption) were increased significantly in HG-treated cells. Moreover, the Erk inhibitor U0126 prevented HG-induced mTOR activation. Increased phospho-AMPKα, CHOP and Grp78 as well as cellular apoptosis were prevented by mTOR inhibitor rapamycin in HG-treated podocytes. Conclusion: Our data demonstrate that the activated mTOR by Erk1/2 results in energy consumption, which in turn leads to ER stress signaling and thus induces apoptosis in HG-treated podocytes.

scholarly journals Inhibition of Renal Tubular Epithelial Mesenchymal Transition and Endoplasmic Reticulum Stress-Induced Apoptosis with Shenkang Injection Attenuates Diabetic Tubulopathy

2021 ◽  
Vol 12 ◽  
Author(s):  
Wen-Wen Wang ◽  
Ying-Lu Liu ◽  
Mei-Zi Wang ◽  
Huan Li ◽  
Bu-Hui Liu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Kidney Disease ◽  
Er Stress ◽  
Renal Injury ◽  
Mesenchymal Transition ◽  
Renal Tubular ◽  
Induced Apoptosis ◽  
Diabetic Tubulopathy

Background: The proximal renal tubule plays a critical role in diabetic kidney disease (DKD) progression. Early glomerular disease in DKD triggers a cascade of injuries resulting in renal tubulointerstitial disease. These pathophysiological responses are collectively described as diabetic tubulopathy (DT). Thus, therapeutic strategies targeting DT hold significant promise for early DKD treatment. Shenkang injection (SKI) has been widely used to treat renal tubulointerstitial fibrosis in patients with chronic kidney disease in China. However, it is still unknown whether SKI can alleviate DT. We designed a series of experiments to investigate the beneficial effects of SKI in DT and the mechanisms that are responsible for its effect on epithelial-to-mesenchymal transition (EMT) and endoplasmic reticulum (ER) stress-induced apoptosis in DT.Methods: The modified DKD rat models were induced by uni-nephrectomy, streptozotocin intraperitoneal injection, and a high-fat diet. Following the induction of renal injury, these animals received either SKI, rosiglitazone (ROS), or vehicle, for 42 days. For in vitro research, we exposed NRK-52E cells to high glucose (HG) and 4-phenylbutyric acid (4-PBA) with or without SKI or ROS. Changes in parameters related to renal tubular injury and EMT were analyzed in vivo. Changes in the proportion of apoptotic renal tubular cells and ER stress, and the signaling pathways involved in these changes, were analyzed both in vivo and in vitro.Results: SKI and ROS improved the general condition, the renal morphological appearance and the key biochemical parameters, and attenuated renal injury and EMT in the rat model of DKD. In addition, SKI and ROS alleviated apoptosis, inhibited ER stress, and suppressed PERK-eIF2α-ATF4-CHOP signaling pathway activation both in vivo and in vitro. Notably, our data showed that the regulatory in vitro effects of SKI on PERK-eIF2α-ATF4-CHOP signaling were similar to those of 4-PBA, a specific inhibitor of ER stress.Conclusion: This study confirmed that SKI can alleviate DT in a similar manner as ROS, and SKI achieves this effect by inhibiting EMT and ER stress-induced apoptosis. Our findings thereby provide novel information relating to the clinical value of SKI in the treatment of DT.

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