scholarly journals Activation of the Endoplasmic Reticulum Stress Response Impacts the NOD1 Signaling Pathway

2019 ◽  
Vol 87 (8) ◽  
Author(s):  
Jonathan M. Mendez ◽  
Lakshmi Divya Kolora ◽  
James S. Lemon ◽  
Steven L. Dupree ◽  
A. Marijke Keestra-Gounder
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Bacterial Infections ◽  
Diaminopimelic Acid ◽  
Endoplasmic Reticulum Stress Response ◽  
Luciferase Reporter ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Raw264.7 Macrophages ◽  
Stimulation Of

ABSTRACT Nucleotide-binding oligomerization domain 1 (NOD1) is an intracellular pattern recognition receptor (PRR) responsible for sensing bacterial peptidoglycan fragments. Stimulation of NOD1 leads to a robust innate immune response via activation of the major transcription factor NF-κB. In addition to peptidoglycan sensing, NOD1 and the closely related PRR NOD2 have been linked to inflammation by responding to the endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR). Here we show that differential ER stress induction renders cells more susceptible to Salmonella enterica serovar Typhimurium infection in a NOD1-dependent manner, measured by increased NF-κB activation and cytokine expression. In HeLa57A cells stably transfected with an NF-κB::luciferase reporter, we show that cells undergoing ER stress induced by thapsigargin display a significant increase in NF-κB activation in response to NOD1 stimulation by C12-iE-DAP (acylated derivative of the iE-DAP dipeptide [gamma-d-glutamyl-meso-diaminopimelic acid]) and the S. Typhimurium effector protein SopE. Tunicamycin-induced ER stress had no effect on NOD1-stimulated NF-κB activation. We further show that the mouse intestinal epithelial cell line MODE-K and RAW264.7 macrophages are more responsive to Salmonella infection when treated with thapsigargin but not with tunicamycin. These profound differences between thapsigargin- and tunicamycin-treated cells upon inflammation suggest that different components downstream of the UPR contribute to NOD1 activation. We found that the NOD1-induced inflammatory response is dependent on protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) activation in conjunction with stimulation of the inositol triphosphate receptor (IP3R). Together, these results suggest that differential UPR activation makes cells more responsive to bacterial infections in a NOD1-dependent manner.

scholarly journals Nickel Enhances Zinc-Induced Neuronal Cell Death by Priming the Endoplasmic Reticulum Stress Response

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ken-ichiro Tanaka ◽  
Misato Kasai ◽  
Mikako Shimoda ◽  
Ayane Shimizu ◽  
Maho Kubota ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Stress Response ◽  
Trace Metals ◽  
Er Stress ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Endoplasmic Reticulum Stress Response ◽  
Dependent Manner ◽  
Er Stress Response

Trace metals such as zinc (Zn), copper (Cu), and nickel (Ni) play important roles in various physiological functions such as immunity, cell division, and protein synthesis in a wide variety of species. However, excessive amounts of these trace metals cause disorders in various tissues of the central nervous system, respiratory system, and other vital organs. Our previous analysis focusing on neurotoxicity resulting from interactions between Zn and Cu revealed that Cu2+ markedly enhances Zn2+-induced neuronal cell death by activating oxidative stress and the endoplasmic reticulum (ER) stress response. However, neurotoxicity arising from interactions between zinc and metals other than copper has not been examined. Thus, in the current study, we examined the effect of Ni2+ on Zn2+-induced neurotoxicity. Initially, we found that nontoxic concentrations (0–60 μM) of Ni2+ enhance Zn2+-induced neurotoxicity in an immortalized hypothalamic neuronal cell line (GT1-7) in a dose-dependent manner. Next, we analyzed the mechanism enhancing neuronal cell death, focusing on the ER stress response. Our results revealed that Ni2+ treatment significantly primed the Zn2+-induced ER stress response, especially expression of the CCAAT-enhancer-binding protein homologous protein (CHOP). Finally, we examined the effect of carnosine (an endogenous peptide) on Ni2+/Zn2+-induced neurotoxicity and found that carnosine attenuated Ni2+/Zn2+-induced neuronal cell death and ER stress occurring before cell death. Based on our results, Ni2+ treatment significantly enhances Zn2+-induced neuronal cell death by priming the ER stress response. Thus, compounds that decrease the ER stress response, such as carnosine, may be beneficial for neurological diseases.

scholarly journals Activation of endoplasmic reticulum stress response during the development of ischemic heart disease

2006 ◽  
Vol 291 (3) ◽  
pp. H1411-H1420 ◽  
Author(s):  
Asim Azfer ◽  
Jianli Niu ◽  
Linda M. Rogers ◽  
Frances M. Adamski ◽  
Pappachan E. Kolattukudy
Keyword(s):  
Endoplasmic Reticulum ◽  
Heart Disease ◽  
Stress Response ◽  
Transgenic Mice ◽  
Ischemic Heart Disease ◽  
Er Stress ◽  
Stress Proteins ◽  
Gene Array ◽  
Ischemic Heart ◽  
Endoplasmic Reticulum Stress Response

Endoplasmic reticulum (ER) stress has been found to be associated with neurodegenerative diseases and diabetes mellitus. Whether ER stress is involved in the development of heart disease is not known. Cardiac-specific expression of monocyte chemoattractant protein-1 (MCP-1) in mice causes the development of ischemic heart disease. Here we report that microarray analysis of gene expression changes in the heart of these transgenic mice revealed that a cluster of ER stress-related genes was transcriptionally activated in the heart during the development of ischemic heart disease. The gene array results were verified by quantitative real-time PCR that showed highly elevated transcript levels of genes involved in unfolded protein response such as ER and cytoplasmic chaperones, oxidoreductases, protein disulfide isomerase (PDI) family, and ER-associated degradation system such as ubiquitin. Immunoblot analysis confirmed the expression of chaperones, PDI, and ubiquitin. Immunohistochemical analyses showed that ER stress proteins were associated mainly with the degenerating cardiomyocytes. A novel ubiquitin fold modifier (Ufm1) that has not been previously associated with ER stress and not found to be induced under any condition was also found to be upregulated in the hearts of MCP mice (transgenic mice that express MCP-1 specifically in the heart). The present results strongly suggest that activation of ER stress response is involved in the development of ischemic heart disease in this murine model.

scholarly journals Activation of Hepatitis B Virus S Promoter by a Cell Type-Restricted IRE1-Dependent Pathway Induced by Endoplasmic Reticulum Stress

2005 ◽  
Vol 25 (17) ◽  
pp. 7522-7533 ◽  
Author(s):  
Zhi-Ming Huang ◽  
Thomas Tan ◽  
Hiderou Yoshida ◽  
Kazutoshi Mori ◽  
Yanjun Ma ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Er Stress ◽  
Transcriptional Activation ◽  
Active Form ◽  
Dominant Negative ◽  
Dependent Manner ◽  
Cell Type ◽  
B Virus

ABSTRACT IRE1-alpha is an integral membrane protein of the endoplasmic reticulum (ER) that is a key sensor in the cellular transcriptional response to stress in the ER. Upon induction of ER stress, IRE1-alpha is activated, resulting in the synthesis of the active form of the transcription factor XBP1 via IRE1-mediated splicing of its mRNA. In this report, we have examined the role of IRE1-alpha and XBP1 in activation of the hepatitis B virus S promoter by ER stress. Cotransfection experiments revealed that overexpression of either IRE1-alpha or XBP1 activated this promoter. Conversely, cotransfected dominant-negative IRE1-alpha or small interfering RNA directed against XBP1 decreased the activation of the S promoter by ER stress, confirming an important role for the IRE1-alpha/XBP1 signaling pathway in activation of the S promoter. However, XBP1 does not bind directly to the S promoter; rather, a novel S promoter-binding complex that does not contain XBP1 is induced in cells undergoing ER stress in an XBP1-dependent manner. This complex, as well as transcriptional activation of the S promoter, is induced by ER stress in hepatocytes but not in fibroblasts, despite the presence of active XBP1 in the latter. Thus, the hepatitis B virus S promoter responds to a novel, cell type-restricted transcriptional pathway downstream of IRE1-alpha and XBP1.

scholarly journals Endoplasmic Reticulum Stress Mediates Vascular Smooth Muscle Cell Calcification via Increased Release of Grp78-Loaded Extracellular Vesicles

2020 ◽  
Author(s):  
Malgorzata Furmanik ◽  
Rick van Gorp ◽  
Meredith Whitehead ◽  
Sadia Ahmad ◽  
Jayanta Bordoloi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Er Stress ◽  
Vascular Calcification ◽  
Bone Mineralization ◽  
Extracellular Vesicle ◽  
Dependent Manner ◽  
The Matrix ◽  
Stress Dependent

Objective: Vascular calcification is common among aging populations and mediated by vascular smooth muscle cells (VSMCs). The endoplasmic reticulum (ER) is involved in protein folding and ER stress has been implicated in bone mineralization. The role of ER stress in VSMC-mediated calcification is less clear. Approach and Results: mRNA expression of the ER stress markers PERK (PKR (protein kinase RNA)-like ER kinase), ATF (activating transcription factor) 4, ATF6, and Grp78 was detectable in human vessels with levels of PERK decreased in calcified plaques compared to healthy vessels. Protein deposition of Grp78/Grp94 was increased in the matrix of calcified arteries. Induction of ER stress accelerated human primary VSMC-mediated calcification, elevated expression of some osteogenic markers (Runx2, Osterix, ALP, BSP, and OPG), and decreased expression of SMC markers. ER stress potentiated extracellular vesicle (EV) release via SMPD3. EVs from ER stress-treated VSMCs showed increased Grp78 levels and calcification. Electron microscopy confirmed the presence of Grp78/Grp94 in EVs. siRNA knock-down of Grp78 decreased calcification. Warfarin-induced Grp78 and ATF4 expression in rat aortas and VSMCs and increased calcification in an ER stress-dependent manner via increased EV release. Conclusions: ER stress induces vascular calcification by increasing release of Grp78-loaded EVs. Our results reveal a novel mechanism of action of warfarin, involving increased EV release via the PERK-ATF4 pathway, contributing to calcification. This study is the first to show that warfarin induces ER stress and to link ER stress to cargo loading of EVs.

scholarly journals The PERK-Dependent Molecular Mechanisms as a Novel Therapeutic Target for Neurodegenerative Diseases

2020 ◽  
Vol 21 (6) ◽  
pp. 2108 ◽  
Author(s):  
Wioletta Rozpędek-Kamińska ◽  
Natalia Siwecka ◽  
Adam Wawrzynkiewicz ◽  
Radosław Wojtczak ◽  
Dariusz Pytel ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Neurodegenerative Diseases ◽  
Er Stress ◽  
Molecular Mechanisms ◽  
Treatment Strategies ◽  
Stress Conditions ◽  
World Population ◽  
Dependent Manner ◽  
Age Related ◽  
The Unfolded Protein Response

Higher prevalence of neurodegenerative diseases is strictly connected with progressive aging of the world population. Interestingly, a broad range of age-related, neurodegenerative diseases is characterized by a common pathological mechanism—accumulation of misfolded and unfolded proteins within the cells. Under certain circumstances, such protein aggregates may evoke endoplasmic reticulum (ER) stress conditions and subsequent activation of the unfolded protein response (UPR) signaling pathways via the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent manner. Under mild to moderate ER stress, UPR has a pro-adaptive role. However, severe or long-termed ER stress conditions directly evoke shift of the UPR toward its pro-apoptotic branch, which is considered to be a possible cause of neurodegeneration. To this day, there is no effective cure for Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), or prion disease. Currently available treatment approaches for these diseases are only symptomatic and cannot affect the disease progression. Treatment strategies, currently under detailed research, include inhibition of the PERK-dependent UPR signaling branches. The newest data have reported that the use of small-molecule inhibitors of the PERK-mediated signaling branches may contribute to the development of a novel, ground-breaking therapeutic approach for neurodegeneration. In this review, we critically describe all the aspects associated with such targeted therapy against neurodegenerative proteopathies.

scholarly journals Tunicamycin-Induced Endoplasmic Reticulum Stress Mediates Mitochondrial Dysfunction in Human Adipocytes

2020 ◽  
Vol 105 (9) ◽  
pp. 2905-2918
Author(s):  
Laura Jackisch ◽  
Alice M Murphy ◽  
Sudhesh Kumar ◽  
Harpal Randeva ◽  
Gyanendra Tripathi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Mitochondrial Dysfunction ◽  
Oxidative Capacity ◽  
Basal Respiration ◽  
Dependent Manner ◽  
Human Adipocytes ◽  
Mitochondrial Fragmentation ◽  
Dynamic Relationship ◽  
Obese Subjects

Abstract Context Dysfunctional endoplasmic reticulum (ER) and mitochondria are known to contribute to the pathology of metabolic disease. This damage may occur, in part, as a consequence of ER-mitochondria cross-talk in conditions of nutrient excess such as obesity. To date, insight into this dynamic relationship has not been characterized in adipose tissue. Therefore, this study investigated whether ER stress contributes to the development of mitochondrial inefficiency in human adipocytes from lean and obese participants. Methods Human differentiated adipocytes from Chub-S7 cell line and primary abdominal subcutaneous adipocytes from lean and obese participants were treated with tunicamycin to induce ER stress. Key parameters of mitochondrial function were assessed, including mitochondrial respiration, membrane potential (MMP), and dynamics. Results ER stress led to increased respiratory capacity in a model adipocyte system (Chub-S7 adipocytes) in a concentration and time dependent manner (24 h: 23%↑; 48 h: 68%↑, P < 0.001; 72 h: 136%↑, P < 0.001). This corresponded with mitochondrial inefficiency and diminished MMP, highlighting the formation of dysfunctional mitochondria. Morphological analysis revealed reorganization of mitochondrial network, specifically mitochondrial fragmentation. Furthermore, p-DRP1, a key protein in fission, significantly increased (P < 0.001). Additionally, adipocytes from obese subjects displayed lower basal respiration (49%↓, P < 0.01) and were unresponsive to tunicamycin in contrast to their lean counterparts, demonstrating inefficient mitochondrial oxidative capacity. Conclusion These human data suggest that adipocyte mitochondrial inefficiency is driven by ER stress and exacerbated in obesity. Nutrient excess–induced ER stress leads to mitochondrial dysfunction that may therefore shift lipid deposition ectopically and thus have further implications on the development of related metabolic disorders.

scholarly journals Endoplasmic reticulum stress regulates cell injury in lipopolysaccharide-induced nerve cells

2020 ◽  
Vol 48 (9) ◽  
pp. 030006052094976
Author(s):  
Min Li ◽  
Ying Zhang ◽  
Jixing Wang
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Viability ◽  
Er Stress ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Cell Injury ◽  
Cell Counting ◽  
Tunel Staining ◽  
Dependent Manner ◽  
Stress Markers

Objective Sepsis-associated encephalopathy (SAE) is a common complication of sepsis, and excessive endoplasmic reticulum (ER) stress is closely correlated with the cell injury caused by sepsis. This study aimed to analyze the possible role of ER stress in SAE cell models. Methods PC12 and MES23.5 cells were treated with increasing concentrations of lipopolysaccharides (LPS). The Cell Counting Kit-8 assay was used to detect cell viability and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess cell apoptosis. In addition, the protein expression levels of ER stress markers [GRP78, CHOP, inositol-requiring enzyme 1 (IRE1), and PKR-like ER kinase (PERK)] and apoptosis-related proteins (Bax, Bcl-2, caspase-3, and cleaved caspase-3) were analyzed using western blotting. Results LPS treatment activated ER stress markers in both the PC12 and MES23.5 cells. The overexpression of GRP78 significantly reduced cell viability and enhanced cell apoptosis in a time-dependent manner. An ER stress inhibitor, 4-PBA, significantly enhanced cell viability and inhibited the cell apoptosis induced by LPS. Therefore, an enhanced unfolded protein response (UPR) and UPR suppression may regulate cell apoptosis. Conclusions UPR was shown to be involved in regulating LPS-induced neuron injury. UPR could be a potential therapeutic target in SAE.

scholarly journals Identification of TFII-I as the Endoplasmic Reticulum Stress Response Element Binding Factor ERSF: Its Autoregulation by Stress and Interaction with ATF6

2001 ◽  
Vol 21 (9) ◽  
pp. 3220-3233 ◽  
Author(s):  
Ronald Parker ◽  
Trevor Phan ◽  
Peter Baumeister ◽  
Binayak Roy ◽  
Venugopalan Cheriyath ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Stress Response ◽  
Mammalian Cells ◽  
Phosphorylation Site ◽  
Endoplasmic Reticulum Stress Response ◽  
Sequence Motif ◽  
Response Element ◽  
Potent Inducer ◽  
Stressed Cells ◽  
Stimulation Of

ABSTRACT When mammalian cells are subjected to stress targeted to the endoplasmic reticulum (ER), such as depletion of the ER Ca2+ store, the transcription of a family of glucose-regulated protein (GRP) genes encoding ER chaperones is induced. The GRP promoters contain multiple copies of the ER stress response element (ERSE), consisting of a unique tripartite structure, CCAAT(N9)CCACG. Within a subset of mammalian ERSEs, N9 represents a GC-rich sequence of 9 bp that is conserved across species. A novel complex (termed ERSF) exhibits enhanced binding to the ERSE of the grp78 and ERp72 promoters using HeLa nuclear extracts prepared from ER-stressed cells. Optimal binding of ERSF to ERSE and maximal ERSE-mediated stress inducibility require the conserved GGC motif within the 9-bp region. Through chromatographic purification and subsequent microsequencing, we have identified ERSF as TFII-I. Whereas TFII-I remains predominantly nuclear in both nontreated NIH 3T3 cells and cells treated with thapsigargin (Tg), a potent inducer of the GRP stress response through depletion of the ER Ca2+ store, the level of TFII-I transcript was elevated in Tg-stressed cells, correlating with an increase in TFII-I protein level in the nuclei of Tg-stressed cells. Purified recombinant TFII-I isoforms bind directly to the ERSEs of grp78 and ERp72 promoters. The stimulation of ERSE-mediated transcription by TFII-I requires the consensus tyrosine phosphorylation site of TFII-I and the GGC sequence motif of the ERSE. We further discovered that TFII-I is an interactive protein partner of ATF6 and that optimal stimulation of ERSE by ATF6 requires TFII-I.

scholarly journals Endoplasmic reticulum stress response in the roadway for the effects of non-steroidal anti-inflammatory drugs

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Fernanda L.B. Mügge ◽  
Aristóbolo M. Silva
Keyword(s):  
Endoplasmic Reticulum ◽  
Stress Response ◽  
Er Stress ◽  
Stress Responses ◽  
Endoplasmic Reticulum Stress Response ◽  
The Road ◽  
Er Stress Response ◽  
Mediated Effects ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

AbstractOver the past decade, a handful of evidence has been provided that nonsteroidal anti-inflammatory drugs (NSAIDs) display effects on the homeostasis of the endoplasmic reticulum (ER). Their uptake into cells will eventually lead to activation or inhibition of key molecules that mediate ER stress responses, raising not only a growing interest for a pharmacological target in ER stress responses but also important questions how the ER-stress mediated effects induced by NSAIDs could be therapeutically advantageous or not. We review here the toxicity effects and therapeutic applications of NSAIDs involving the three majors ER stress arms namely PERK, IRE1, and ATF6. First, we provide brief introduction on the well-established and characterized downstream events mediated by these ER stress players, followed by presentation of the NSAIDs compounds and mode of action, and finally their effects on ER stress response. NSAIDs present promising drug agents targeting the components of ER stress in different aspects of cancer and other diseases, but a better comprehension of the mechanisms underlying their benefits and harms will certainly pave the road for several diseases’ therapy.

ER stress triggers MCP-1 expression through SET7/9-induced histone methylation in the kidneys of db/db mice

2014 ◽  
Vol 306 (8) ◽  
pp. F916-F925 ◽  
Author(s):  
Jigang Chen ◽  
Yanhong Guo ◽  
Wei Zeng ◽  
Li Huang ◽  
Qi Pang ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Er Stress ◽  
Regulatory Mechanism ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Reporter Assay ◽  
Monocyte Chemoattractant Protein 1 ◽  
Monocyte Chemoattractant ◽  
Glucose Regulated Protein

Epigenetics plays a key role in the pathogenesis of diabetic nephropathy (DN), although the precise regulatory mechanism is still unclear. Here, we examined the role of endoplasmic reticulum (ER) stress in histone H3 lysine 4 (H3K4) methyltransferase SET7/9-induced monocyte chemoattractant protein-1 (MCP-1) expression in the kidneys of db/db mice. Our results indicate that the expression of MCP-1 significantly increased in the kidneys of db/db mice in a time-dependent manner. An increased chromatin mark associated with an active gene (H3K4me1) at MCP-1 promoters accompanied this change in expression. The expression of SET7/9 and the recruitment to these promoters were also elevated. SET7/9 gene silencing with small interfering (si) RNAs significantly attenuated the expression of H3K4me1 and MCP-1. Furthermore, expression of signaling regulator glucose-regulated protein 78 (GRP78), a monitor of ER stress, significantly increased in the kidneys of db/db mice. The expression of spliced X-box binding protein 1 (XBP1s), an ER stress-inducible transcription factor, and recruitment to the SET7/9 promoters were also increased. XBP1s gene silencing with siRNAs significantly attenuated the expression of SET7/9, H3K4me1, and MCP-1. The chaperone betaine not only effectively downregulated the GRP78 and XBP1s expression levels but also markedly decreased the SET7/9, H3K4me1, and MCP-1 levels. Luciferase reporter assay demonstrated that XBP1s participated in ER stress-induced SET7/9 transcription, Taken together, these results reveal that ER stress can trigger the expression of MCP-1, in part through the XBP1s-mediated induction of SET7/9.

Sign in / Sign up

Export Citation Format

Share Document