scholarly journals Mst2 Overexpression Inhibits Thyroid Carcinoma Growth and Metastasis by Disrupting Mitochondrial Fitness and Endoplasmic Reticulum Homeostasis

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Haichao Zhang ◽  
Xin Qu ◽  
Lu Han ◽  
Xu Di
Keyword(s):  
Endoplasmic Reticulum ◽  
Thyroid Carcinoma ◽  
Er Stress ◽  
Molecular Therapy ◽  
Apoptotic Pathway ◽  
Jnk Pathway ◽  
Mitochondrial Oxidative Stress ◽  
Proapoptotic Protein ◽  
Pathway Inhibition ◽  
Tumor Types

Although the incidence of thyroid carcinoma has increased over the past several decades, it has an excellent prognosis and overall 5-year survival, with a stable mortality rate, except in cases with advanced stages or rare malignant tumor types. Biomarkers have emerged as effective targets of molecular therapy against thyroid carcinoma due to their rapid and convenient detection; however, there has been little clinical application. Macrophage stimulating 2 (Mst2) is a proapoptotic protein with implications in carcinogenesis and metastasis. We found that Mst2 overexpression-induced endoplasmic reticulum (ER) stress in MDA-T32 thyroid carcinoma cells, accompanied by elevated caspase-12 activity, increased apoptotic rate, and reduced cell viability. In addition, Mst2 overexpression contributed to mitochondrial damage, as evidenced by increased mitochondrial oxidative stress and activated the mitochondrial apoptotic pathway. Inhibition of the JNK pathway abolished these effects. These results show Mst2 to be a novel tumor suppressor that induces mitochondrial dysfunction and ER stress via the JNK pathway. Thus, Mst2 could potentially serve as a biomarker for developing targeted therapy against thyroid carcinoma.

scholarly journals Ovarian steroid dependence of endoplasmic reticulum stress involvement in endometrial cell apoptosis during the human endometrial cycle

Reproduction ◽  
2018 ◽  
Vol 155 (6) ◽  
pp. 493-503 ◽  
Author(s):  
Jong Yeob Choi ◽  
Min Wha Jo ◽  
Eun Young Lee ◽  
Dong-Yun Lee ◽  
Doo Seok Choi
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Steroid Hormones ◽  
Cellular Stress Response ◽  
Apoptosis Induction ◽  
Ovarian Steroid ◽  
Secretory Phase ◽  
Apoptotic Pathway ◽  
Endometrial Cells ◽  
Chop Expression

Endoplasmic reticulum (ER) stress is a common cellular stress response that enhances apoptosis to trigger cell death. However, recent studies have shown that estrogen suppresses apoptosis by inhibiting ER stress in some cell types, suggesting that ER stress-induced apoptosis is regulated by ovarian steroid hormones. In endometrial cells, ER stress may also be controlled by ovarian steroid hormones and could be involved in apoptosis induction during the menstrual cycle. To test this hypothesis, we elucidate whether ER stress is regulated by ovarian steroid hormones in human endometrial cells and if it is involved in apoptosis induction. Specifically, we sought to determine the effects of estrogen and progesterone on the PERK/eIF2α/ATF4/CHOP pathway, a pro-apoptotic pathway mediated by ER stress. Our results show that ER stress maker GRP78 expression was increased in human endometrial Ishikawa and endometrial stromal cells (ESCs) treated with tunicamycin. Addition of estrogen decreased tunicamycin-induced GRP78 expression. In contrast, progesterone treatment increased GRP78 in estrogen-treated Ishikawa and ESCs, which significantly increased CHOP expression through phosphorylation of eIF2α and upregulation of ATF4. This upregulation was accompanied by an increased apoptosis induction. The progesterone-induced increase in apoptosis was reversed by either mifepristone (progesterone receptor modulator) or salubrinal (ER stress inhibitor). Furthermore, our in vivo results also showed that GRP78, CHOP expression and apoptosis were significantly increased in endometrial cells during the secretory phase as well as by in vitro treatment with progesterone. In conclusion, our results suggest that estrogen inhibits ER stress in human endometrial cells. This inhibition is reversed by progesterone during the secretory phase, and this is directly involved in apoptosis induction.

scholarly journals Caspase-mediated cleavage of IRE1 controls apoptotic cell commitment during endoplasmic reticulum stress

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Anna Shemorry ◽  
Jonathan M Harnoss ◽  
Ofer Guttman ◽  
Scot A Marsters ◽  
László G Kőműves ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Apoptotic Cell ◽  
Leukemia Cell ◽  
Unfolded Protein ◽  
Proapoptotic Protein ◽  
Stress Sensing ◽  
The Unfolded Protein Response ◽  
Cell Commitment ◽  
Protein Response

Upon detecting endoplasmic reticulum (ER) stress, the unfolded protein response (UPR) orchestrates adaptive cellular changes to reestablish homeostasis. If stress resolution fails, the UPR commits the cell to apoptotic death. Here we show that in hematopoietic cells, including multiple myeloma (MM), lymphoma, and leukemia cell lines, ER stress leads to caspase-mediated cleavage of the key UPR sensor IRE1 within its cytoplasmic linker region, generating a stable IRE1 fragment comprising the ER-lumenal domain and transmembrane segment (LDTM). This cleavage uncouples the stress-sensing and signaling domains of IRE1, attenuating its activation upon ER perturbation. Surprisingly, LDTM exerts negative feedback over apoptotic signaling by inhibiting recruitment of the key proapoptotic protein BAX to mitochondria. Furthermore, ectopic LDTM expression enhances xenograft growth of MM tumors in mice. These results uncover an unexpected mechanism of cross-regulation between the apoptotic caspase machinery and the UPR, which has biologically significant consequences for cell survival under ER stress.

scholarly journals Sec62 Regulates Endoplasmic Reticulum Stress and Autophagy Balance to Affect Foot-and-Mouth Disease Virus Replication

2021 ◽  
Vol 11 ◽  
Author(s):  
Jin’en Wu ◽  
Zhihui Zhang ◽  
Zhidong Teng ◽  
Sahibzada Waheed Abdullah ◽  
Shiqi Sun ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Jnk Pathway ◽  
Fmdv Infection ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Fmdv Replication

Endoplasmic reticulum (ER) stress-induced autophagy is closely associated with viral infection and propagation. However, the intrinsic link between ER stress, autophagy, and viral replication during foot-and-mouth disease virus (FMDV) infection is not fully elucidated. Our previous studies demonstrated that FMDV infection activated the ER stress-associated UPR of the PERK-eIF2a and ATF6 signaling pathway, whereas the IRE1a signaling was suppressed. We found that the activated-ATF6 pathway participated in FMDV-induced autophagy and FMDV replication, while the IRE1α pathway only affected FMDV replication. Further studies indicated that Sec62 was greatly reduced in the later stages of FMDV infection and blocked the activation of the autophagy-related IRE1α-JNK pathway. Moreover, it was also found that Sec62 promoted IRE1a phosphorylation and negatively regulated FMDV proliferation. Importantly, Sec62 may interact with LC3 to regulate ER stress and autophagy balance and eventually contribute to FMDV clearance via fusing with lysosomes. Altogether, these results suggest that Sec62 is a critical molecule in maintaining and recovering ER homeostasis by activating the IRE1α-JNK pathway and delivering autophagosome into the lysosome, thus providing new insights on FMDV-host interactions and novel antiviral therapies.

scholarly journals The Interplay of Mitochondrial Oxidative Stress and Endoplasmic Reticulum Stress in Cardiovascular Fibrosis in Obese Rats

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1274
Author(s):  
Francisco V. Souza-Neto ◽  
Sara Jiménez-González ◽  
Beatriz Delgado-Valero ◽  
Raquel Jurado-López ◽  
Marie Genty ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Control Diet ◽  
Ang Ii ◽  
Mitochondrial Oxidative Stress ◽  
Relevant Role ◽  
Male Wistar Rats ◽  
Cardiovascular Fibrosis ◽  
Stress Activation

We have evaluated the role of mitochondrial oxidative stress and its association with endoplasmic reticulum (ER) stress activation in the progression of obesity-related cardiovascular fibrosis. MitoQ (200 µM) was orally administered for 7 weeks to male Wistar rats that were fed a high-fat diet (HFD, 35% fat) or a control diet (CT, 3.5% fat). Obese animals presented cardiovascular fibrosis accompanied by increased levels of extracellular matrix proteins and profibrotic mediators. These alterations were associated with ER stress activation characterized by enhanced levels (in heart and aorta vs. CT group, respectively) of immunoglobulin binding protein (BiP; 2.1-and 2.6-fold, respectively), protein disulfide-isomerase A6 (PDIA6; 1.9-fold) and CCAAT-enhancer-binding homologous protein (CHOP; 1.5- and 1.8-fold, respectively). MitoQ treatment was able to prevent (p < 0.05) these modifications at cardiac and aortic levels. MitoQ (5 nM) and the ER stress inhibitor, 4-phenyl butyric acid (4 µM), were able to block the prooxidant and profibrotic effects of angiotensin II (Ang II, 10−6 M) in cardiac and vascular cells. Therefore, the data show a crosstalk between mitochondrial oxidative stress and ER stress activation, which mediates the development of cardiovascular fibrosis in the context of obesity and in which Ang II can play a relevant role.

scholarly journals A novel endoplasmic stress mediator, Kelch domain containing 7B (KLHDC7B), increased Harakiri (HRK) in the SubAB-induced apoptosis signaling pathway

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kinnosuke Yahiro ◽  
Kohei Ogura ◽  
Hiroyasu Tsutsuki ◽  
Sunao Iyoda ◽  
Makoto Ohnishi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Signaling Pathway ◽  
Gastrointestinal Symptoms ◽  
Parp Cleavage ◽  
Rna Seq ◽  
Gene Encoding ◽  
Apoptotic Pathway ◽  
Kelch Domain ◽  
Induced Apoptosis

AbstractLocus for Enterocyte Effacement (LEE)-positive Shiga-toxigenic Escherichia coli (STEC) contributes to many global foodborne diseases, with infection characterized by severe gastrointestinal symptoms, including bloody diarrhea. The incidence of LEE-negative STEC-mediated disease is also increasing globally. Subtilase cytotoxin (SubAB) is released by some LEE-negative STEC strains. It cleaves BiP, which is a chaperone protein located in the endoplasmic reticulum (ER), thereby causing apoptosis induced by ER stress. To date, the apoptotic signaling pathway mediated by SubAB has not been identified. In the current study, RNA-seq analysis showed that SubAB significantly induced the expression of Kelch domain containing 7B (KLHDC7B). We explored the role of KLHDC7B in the SubAB-induced apoptotic pathway. SubAB-induced KLHDC7B mRNA expression was increased after 12 h of incubation of toxin with HeLa cells. KLHDC7B expression was downregulated by knockdown of PKR-like endoplasmic reticulum kinase (PERK), CEBP homologous protein (CHOP), activating transcription factor 4 (ATF4), and CEBP β (CEBPB). KLHDC7B knockdown suppressed SubAB-stimulated CHOP expression, poly(ADP-ribose) polymerase (PARP) cleavage, and cytotoxicity. The over-expressed KLHDC7B was localized to the nucleus and cytosolic fractions. Next, we used RNA-seq to analyze the effect of KLHDC7B knockdown on apoptosis induced by SubAB, and found that the gene encoding for the pro-apoptotic Bcl-2 family protein, Harakiri (HRK), was upregulated in SubAB-treated control cells. However, this effect was not observed in SubAB-treated KLHDC7B-knockdown cells. Therefore, we identified the pathway through which SubAB-induced KLHDC7B regulates HRK expression, which is essential for apoptosis in toxin-mediated ER stress.

Curcumin induces cell death of human papillary thyroid carcinoma BCPAP cells through endoplasmic reticulum stress

RSC Advances ◽  
2016 ◽  
Vol 6 (58) ◽  
pp. 52905-52912 ◽  
Author(s):  
Lixi Zhang ◽  
Li Zhang ◽  
Xian Cheng ◽  
Yanyan Gao ◽  
Jiandong Bao ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Papillary Thyroid Carcinoma ◽  
Endoplasmic Reticulum Stress ◽  
Thyroid Carcinoma ◽  
Er Stress ◽  
Signaling Pathway ◽  
Papillary Thyroid

Curcumin induced cell death of BCPAP cells via ER stress with activation of the ATF6/XBP-1 signaling pathway and Ca2+ release.

scholarly journals Protective role of Gipie, a Girdin family protein, in endoplasmic reticulum stress responses in endothelial cells

2011 ◽  
Vol 22 (6) ◽  
pp. 736-747 ◽  
Author(s):  
Etsushi Matsushita ◽  
Naoya Asai ◽  
Atsushi Enomoto ◽  
Yoshiyuki Kawamoto ◽  
Takuya Kato ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Stress Responses ◽  
Protective Role ◽  
Jnk Pathway ◽  
Interacting Protein ◽  
Family Protein ◽  
Induced Apoptosis ◽  
The Unfolded Protein Response

Continued exposure of endothelial cells to mechanical/shear stress elicits the unfolded protein response (UPR), which enhances intracellular homeostasis and protect cells against the accumulation of improperly folded proteins. Cells commit to apoptosis when subjected to continuous and high endoplasmic reticulum (ER) stress unless homeostasis is maintained. It is unknown how endothelial cells differentially regulate the UPR. Here we show that a novel Girdin family protein, Gipie (78 kDa glucose-regulated protein [GRP78]-interacting protein induced by ER stress), is expressed in endothelial cells, where it interacts with GRP78, a master regulator of the UPR. Gipie stabilizes the interaction between GRP78 and the ER stress sensor inositol-requiring protein 1 (IRE1) at the ER, leading to the attenuation of IRE1-induced c-Jun N-terminal kinase (JNK) activation. Gipie expression is induced upon ER stress and suppresses the IRE1-JNK pathway and ER stress-induced apoptosis. Furthermore we found that Gipie expression is up-regulated in the neointima of carotid arteries after balloon injury in a rat model that is known to result in the induction of the UPR. Thus our data indicate that Gipie/GRP78 interaction controls the IRE1-JNK signaling pathway. That interaction appears to protect endothelial cells against ER stress-induced apoptosis in pathological contexts such as atherosclerosis and vascular endothelial dysfunction.

Cortistatin Improves Cardiac Function After Acute Myocardial Infarction in Rats by Suppressing Myocardial Apoptosis and Endoplasmic Reticulum Stress

2016 ◽  
Vol 22 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Zhi-Yu Shi ◽  
Yue Liu ◽  
Li Dong ◽  
Bo Zhang ◽  
Meng Zhao ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Endoplasmic Reticulum ◽  
Cardiac Function ◽  
Er Stress ◽  
Rat Model ◽  
Caspase 3 ◽  
Apoptotic Pathway ◽  
Myocardial Apoptosis ◽  
Glucose Regulated Protein

Objectives: The endoplasmic reticulum (ER) stress-induced apoptotic pathway is associated with the development of acute myocardial infarction (AMI). Cortistatin (CST) is a novel bioactive peptide that inhibits apoptosis-related injury. Therefore, we investigated the cardioprotective effects and potential mechanisms of CST in a rat model of AMI. Methods: Male Wistar rats were randomly divided into sham, AMI, and AMI + CST groups. Cardiac function and the degree of infarction were evaluated by echocardiography, cardiac troponin I activity, and 2,3,5-triphenyl-2H-tetrazolium chloride staining after 7 days. The expression of CST, ER stress markers, and apoptotic markers was examined using immunohistochemistry and Western blotting. Results: Compared to the AMI group, the AMI + CST group exhibited markedly better cardiac function and a lower degree of infarction. Electron microscopy and terminal deoxynucleotidyl transferase dUTP nick end labeling confirmed that myocardial apoptosis occurred after AMI. Cortistatin treatment reduced the expression of caspase 3, cleaved caspase 3, and Bax (proapoptotic proteins) and promoted the expression of Bcl-2 (antiapoptotic protein). In addition, the reduced expression of glucose-regulated protein 94 (GRP94), glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding proteins homologous protein, and caspase 12 indicated that ER stress and the apoptotic pathway associated with ER stress were suppressed. Conclusions: Exogenous CST has a notable cardioprotective effect after AMI in a rat model in that it improves cardiac function by suppressing ER stress and myocardial apoptosis.

scholarly journals Hyperglycemia Induces Endoplasmic Reticulum Stress in Atrial Cardiomyocytes, and Mitofusin-2 Downregulation Prevents Mitochondrial Dysfunction and Subsequent Cell Death

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Ming Yuan ◽  
Mengqi Gong ◽  
Zhiwei Zhang ◽  
Lei Meng ◽  
Gary Tse ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Mitochondrial Dysfunction ◽  
High Glucose ◽  
Atrial Remodeling ◽  
Mitofusin 2 ◽  
Mitochondrial Oxidative Stress ◽  
Atrial Cardiomyocytes

Mitochondrial oxidative stress and dysfunction play an important role of atrial remodeling and atrial fibrillation (AF) in diabetes mellitus. Endoplasmic reticulum (ER) stress has been linked to both physiological and pathological states including diabetes. The aim of this project is to explore the roles of ER stress in hyperglycemia-induced mitochondrial dysfunction and cell death of atrial cardiomyocytes. High glucose upregulated ER stress, mitochondrial oxidative stress, and mitochondria-associated ER membrane (MAM)- enriched proteins (such as glucose-regulated protein 75 (GRP75) and mitofusin-2 (Mfn2)) of primary cardiomyocytes in vitro. Sodium phenylbutyrate (4-PBA) prevented the above changes. Silencing of Mfn2 in HL-1 cells decreased the Ca2+ transfer from ER to mitochondria under ER stress conditions, which were induced by the ER stress agonist, tunicamycin (TM). Electron microscopy data suggested that Mfn2 siRNA significantly disrupted ER-mitochondria tethering in ER stress-injured HL-1 cells. Mfn2 silencing attenuated mitochondrial oxidative stress and Ca2+ overload, increased mitochondrial membrane potential and mitochondrial oxygen consumption, and protected cells from TM-induced apoptosis. In summary, Mfn2 plays an important role in high glucose-induced ER stress in atrial cardiomyocytes, and Mfn2 silencing prevents mitochondrial Ca2+ overload-mediated mitochondrial dysfunction, thereby decreasing ER stress-mediated cardiomyocyte cell death.

Sign in / Sign up

Export Citation Format

Share Document