scholarly journals Epigallocatechin-3-Gallate (EGCG) Promotes Autophagy-Dependent Survival via Influencing the Balance of mTOR-AMPK Pathways upon Endoplasmic Reticulum Stress

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Marianna Holczer ◽  
Boglárka Besze ◽  
Veronika Zámbó ◽  
Miklós Csala ◽  
Gábor Bánhegyi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Egcg Treatment ◽  
Life And Death ◽  
Er Stress Response ◽  
Negative Effect ◽  
External Stimuli

The maintenance of cellular homeostasis is largely dependent on the ability of cells to give an adequate response to various internal and external stimuli. We have recently proposed that the life-and-death decision in endoplasmic reticulum (ER) stress response is defined by a crosstalk between autophagy, apoptosis, and mTOR-AMPK pathways, where the transient switch from autophagy-dependent survival to apoptotic cell death is controlled by GADD34. The aim of the present study was to investigate the role of epigallocatechin-3-gallate (EGCG), the major polyphenol of green tea, in promoting autophagy-dependent survival and to verify the key role in connecting GADD34 with mTOR-AMPK pathways upon prolonged ER stress. Our findings, obtained by using HEK293T cells, revealed that EGCG treatment is able to extend cell viability by inducing autophagy. We confirmed that EGCG-induced autophagy is mTOR-dependent and PKA-independent; furthermore, it also required ULK1. We show that pretreatment of cells with EGCG diminishes the negative effect of GADD34 inhibition (by guanabenz or siGADD34 treatment) on autophagy. EGCG was able to delay apoptotic cell death by upregulating autophagy-dependent survival even in the absence of GADD34. Our data suggest a novel role for EGCG in promoting cell survival via shifting the balance of mTOR-AMPK pathways in ER stress.

scholarly journals 3 β-Hydroxysteroid-Δ 24 Reductase (DHCR24) Protects Neuronal Cells from Apoptotic Cell Death Induced by Endoplasmic Reticulum (ER) Stress

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e86753 ◽  
Author(s):  
Xiuli Lu ◽  
Yang Li ◽  
Weiqi Wang ◽  
Shuchao Chen ◽  
Ting Liu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Apoptotic Cell ◽  
Neuronal Cells ◽  
Apoptotic Cell Death

scholarly journals The long noncoding RNA of RMRP is downregulated by PERK, which induces apoptosis in hepatocellular carcinoma cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atsushi Yukimoto ◽  
Takao Watanabe ◽  
Kotaro Sunago ◽  
Yoshiko Nakamura ◽  
Takaaki Tanaka ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Transcriptome Analysis ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Chronic Liver ◽  
Mitochondrial Rna

AbstractEndoplasmic reticulum (ER) stress plays an important role in hepatocyte degeneration, especially in patients with chronic liver injury. Protein kinase R-like endoplasmic reticulum kinase (PERK) is a key molecule in ER stress. PERK may contribute to apoptotic cell death in HCC, however the details of the mechanism are not clear. In this study, we identified PERK-associated molecules using transcriptome analysis. We modulated PERK expression using a plasmid, tunicamycin and siRNA against PERK, and then confirmed the target gene expression with real-time PCR and Northern blotting. We further analyzed the apoptotic function. Transcriptome analysis revealed that expression of the RNA component of mitochondrial RNA processing endoribonuclease (RMRP), which is a long noncoding RNA, was strongly correlated with the function of PERK. The expression of RMRP was correlated with the expression of PERK in experiments with the siRNA and PERK plasmid in both HCC cell lines and human HCC tissue. Furthermore, RMRP downregulation induced apoptotic cell death. RMRP is downregulated by PERK, which induces apoptosis in HCC. RMRP could be a new therapeutic target to regulate HCC in patients with chronic liver diseases associated with ER stress.

scholarly journals Endoplasmic Reticulum Stress Contributed to Dipyridamole-Induced Impaired Autophagic Flux and Glioma Apoptosis

2022 ◽  
Vol 23 (2) ◽  
pp. 579
Author(s):  
Cheng-Yi Chang ◽  
Chih-Cheng Wu ◽  
Jiaan-Der Wang ◽  
Su-Lan Liao ◽  
Wen-Ying Chen ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Apoptotic Cell ◽  
Glioma Cells ◽  
Apoptotic Cell Death ◽  
Autophagic Flux ◽  
Intracellular Camp ◽  
Cell Proliferation Inhibition ◽  
Camp Levels

Elevation of intracellular cAMP levels has been implicated in glioma cell proliferation inhibition, differentiation, and apoptosis. Inhibition of phosphodiesterase is a way to elevate intracellular cAMP levels. The present study aimed to investigate the anti-glioma potential of dipyridamole, an inhibitor of phosphodiesterase. Upon treatment with dipyridamole, human U87 glioma cells decreased cell viability, clonogenic colonization, migration, and invasion, along with Noxa upregulation, Endoplasmic Reticulum (ER) stress, impaired autophagic flux, Yes-associated Protein 1 (YAP1) phosphorylation, and YAP1 reduction. Pharmacological and genetic studies revealed the ability of dipyridamole to initiate Noxa-guided apoptosis through ER stress. Additionally, the current study further identified the biochemical role of YAP1 in communicating with ER stress and autophagy under situations of dipyridamole treatment. YAP1 promoted autophagy and protected glioma cells from dipyridamole-induced apoptotic cell death. Dipyridamole impaired autophagic flux and rendered glioma cells more vulnerable to apoptotic cell death through ER stress-inhibitable YAP1/autophagy axis. The overall cellular changes caused by dipyridamole appeared to ensure a successful completion of apoptosis. Dipyridamole also duplicated the biochemical changes and apoptosis in glioma T98G cells. Since dipyridamole has additional biochemical and pharmacological properties, further research centered on the anti-glioma mechanisms of dipyridamole is still needed.

scholarly journals Saturated fatty acids induce endoplasmic reticulum stress in primary cardiomyocytes

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Taha Haffar ◽  
Félix-Antoine Bérubé-Simard ◽  
Jean-Claude Tardif ◽  
Nicolas Bousette
Keyword(s):  
Fatty Acids ◽  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Lipid Accumulation ◽  
Apoptotic Cell ◽  
Saturated Fatty Acids ◽  
Fatty Acid Uptake ◽  
Apoptotic Cell Death ◽  
Acid Uptake

AbstractAbstract: Introduction: Diabetes is a major contributor to cardiovascular disease. There is a growing body of evidence pointing towards intra-myocellular lipid accumulation as an integral etiological factor. Here we aimed to determine the effect of two common fatty acids on lipid accumulation and cellular stress in primary cardiomyocytes.Methods: We evaluated lipid accumulation biochemically (by triacylglyceride assay and radiolabeled fatty acid uptake assay) as well as histologically (by BODIPY 493/503 staining) in mouse and rat neonatal cardiomyocytes treated with saturated (palmitate) or mono-unsaturated (oleate) fatty acids. Endoplasmic reticulum (ER) stress was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. Cell viability was assessed by propidium iodide staining.Results: We found that both oleate and palmitate led to significant increases in intracellular lipid in cardiomyocytes; however there were distinct differences in the qualitative nature of BODIPY staining between oleate and palmitate treated cardiomyocytes. We also show that palmitate caused significant apoptotic cell death and this was associated with ER stress. Interestingly, co-administration of oleate with palmitate abolished cell death, and ER stress. Finally, palmitate treatment caused a significant increase in ubiquitination of Grp78, a key compensatory ER chaperone.Conclusion: Palmitate causes ER stress and apoptotic cell death in primary cardiomyocytes and this is associated with apparent differences in BODIPY staining compared to oleate treated cardiomyocytes. Importantly, the lipotoxic effects of palmitate are abolished with the co-administration of oleate.

scholarly journals Neuroprotective Effects of Exercise Postconditioning After Stroke via SIRT1-Mediated Suppression of Endoplasmic Reticulum (ER) Stress

2021 ◽  
Vol 15 ◽  
Author(s):  
Fengwu Li ◽  
Xiaokun Geng ◽  
Hangil Lee ◽  
Melissa Wills ◽  
Yuchuan Ding
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Ros Production ◽  
Post Stroke ◽  
Caspase 12 ◽  
Stress Pathway

While it is well-known that pre-stroke exercise conditioning reduces the incidence of stroke and the development of comorbidities, it is unclear whether post-stroke exercise conditioning is also neuroprotective. The present study investigated whether exercise postconditioning (PostE) induced neuroprotection and elucidated the involvement of SIRT1 regulation on the ROS/ER stress pathway. Adult rats were subjected to middle cerebral artery occlusion (MCAO) followed by either: (1) resting; (2) mild exercise postconditioning (MPostE); or (3) intense exercise postconditioning (IPostE). PostE was initiated 24 h after reperfusion and performed on a treadmill. At 1 and 3 days thereafter, we determined infarct volumes, neurological defects, brain edema, apoptotic cell death through measuring pro- (BAX and Caspase-3) and anti-apoptotic (Bcl-2) proteins, and ER stress through the measurement of glucose-regulated protein 78 (GRP78), inositol-requiring 1α (IRE1α), protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), Caspase-12, and SIRT1. Proteins were measured by Western blot. ROS production was detected by flow cytometry.Compared to resting rats, both MPostE and IPostE significantly decreased brain infarct volumes and edema, neurological deficits, ROS production, and apoptotic cell death. MPostE further increased Bcl-2 expression and Bcl-2/BAX ratio as well as BAX and Caspase-3 expressions and ROS production (*p < 0.05). Both PostE groups saw decreases in ER stress proteins, while MPostE demonstrated a further reduction in GRP78 (***p < 0.001) and Caspase-12 (*p < 0.05) expressions at 1 day and IRE1α (**p < 0.01) and CHOP (*p < 0.05) expressions at 3 days. Additionally, both PostE groups saw significant increases in SIRT1 expression.In this study, both mild and intense PostE levels induced neuroprotection after stroke through SIRT1 and ROS/ER stress pathway. Additionally, the results may provide a base for our future study regarding the regulation of SIRT1 on the ROS/ER stress pathway in the biochemical processes underlying post-stroke neuroprotection. The results suggest that mild exercise postconditioning might play a similar neuroprotective role as intensive exercise and could be an effective exercise strategy as well.

scholarly journals Autocrine Growth Hormone (GH)-Mediated Triptolide Resistance Overcame by Metformin Co-Treatment in MDA-MB231 Breast Cancer Cells Through ER Stress Pathway

Proceedings ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 9
Author(s):  
Amani Abdulmunem ◽  
Pınar Obakan-Yerlikaya ◽  
Elif-Damla Arisan ◽  
Ajda Coker-Gurkan
Keyword(s):  
Breast Cancer ◽  
Growth Hormone ◽  
Cell Death ◽  
Er Stress ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Autocrine Growth ◽  
Common Cancer

Breast cancer is the most common cancer in women worldwide and the second most common cancer overall. Autocrine growth hormone (GH) expression induced cell proliferation, growth, invasion-metastasis in vitro and in vivo breast cancer models. Moreover, forced GH signaling acts as a drug resistance profile in breast cancer cell lines against chemotherapeutic drugs such as tamoxifen, mitomycin C, doxorubicin and curcumin. Triptolide, an active plant extract from Tripterygium wilfordii, has been shown to induce apoptotic cell death in various cancer cells such a prostate, colon, breast cancer. Metformin, a common therapeutic agent for type II Diabetes mellitus, has been shown to induce autophagy, endoplasmic reticulum (ER) stress and apoptotic cell death in cancer cells. Our aim is to demonstrate the potential effect of metformin on triptolide-mediated drug resistance in autocrine GH expressing MDA-MB-231 breast cancer cells through Endoplasmic reticulum (ER) stress. Autocrine GH-mediated triptolide (20 nM) resistance overcame by metformin (2 mM) co-teatment in MDA-MB231 breast cancer cells through accelerating cell viability loss, growth inhibition compared to alone triptolide treatment. Combined treatment increased apoptotic cell death via CHOP activation, IRE1α upregulation. Consequently, we suggest that triptolide can be more effective with metformin combination in MDA-MB-231 GH+ drug resistant breast cancer cells.

Bufalin Induces Apoptotic Cell Death in Human Nasopharyngeal Carcinoma Cells through Mitochondrial ROS and TRAIL Pathways

2019 ◽  
Vol 47 (01) ◽  
pp. 237-257 ◽  
Author(s):  
En-Yun Su ◽  
Yung-Lin Chu ◽  
Fu-Shin Chueh ◽  
Yi-Shih Ma ◽  
Shu-Fen Peng ◽  
...  
Keyword(s):  
Cell Death ◽  
Nasopharyngeal Carcinoma ◽  
Er Stress ◽  
Apoptotic Cell ◽  
Morphological Changes ◽  
Chromatin Condensation ◽  
Apoptotic Cell Death ◽  
Dapi Staining ◽  
Human Nasopharyngeal Carcinoma ◽  
Associated Proteins

The aim of this study was to investigate the effects of bufalin on human nasopharyngeal carcinoma NPC-TW 076 cells in vitro. Bufalin is a cardiotonic steroid and a key active ingredient of the Chinese medicine ChanSu. The extracts of Chansu are used for various cancer treatments in China. In the present study, bufalin induced cell morphological changes, decreased total cell viability and induced G2/M phase arrest of cell cycle in NPC-TW 076 cells. Results also indicated that bufalin induced chromatin condensation (cell apoptosis) and DNA damage by DAPI staining and comet assay, respectively. The induced apoptotic cell death was further confirmed by annexin-V/PI staining assay. In addition, bufalin also increased ROS and Ca[Formula: see text] production and decreased the levels of [Formula: see text]. Furthermore, the alterations of ROS, ER stress and apoptosis associated protein expressions were investigated by Western blotting. Results demonstrated that bufalin increased the expressions of ROS associated proteins, including SOD (Cu/Zn), SOD2 (Mn) and GST but decreased that of catalase. Bufalin increased ER stress associated proteins (GRP78, IRE-1[Formula: see text], IRE-1[Formula: see text], caspase-4, ATF-6[Formula: see text], Calpain 1, and GADD153). Bufalin increased the pro-apoptotic proteins Bax, and apoptotic associated proteins (cytochrome c, caspase-3, -8 and -9, AIF and Endo G) but reduced anti-apoptotic protein Bcl-2 in NPC-TW 076 cells. Furthermore, bufalin elevated the expressions of TRAIL-pathway associated proteins (TRAIL, DR4, DR5, and FADD). Based on these findings, we suggest bufalin induced apoptotic cell death via caspase-dependent, mitochondria-dependent and TRAIL pathways in human nasopharyngeal carcinoma NPC-TW 076 cells.

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