WorldWideScience

Sample records for survive er stress

  1. ER stress and hepatic lipid metabolism

    Directory of Open Access Journals (Sweden)

    Huiping eZhou

    2014-05-01

    Full Text Available The endoplasmic reticulum (ER is an important player in regulating protein synthesis and lipid metabolism. Perturbation of ER homeostasis, referred as ER stress, has been linked to numerous pathological conditions, such as inflammation, cardiovascular diseases and metabolic disorders. The liver plays a central role in regulating nutrient and lipid metabolism. Accumulating evidence implicates that ER stress disrupts lipid metabolism and induces hepatic lipotoxicity. Here, we review the major ER stress signaling pathways, how ER stress contributes to the dysregulation of hepatic lipid metabolism, and the potential causative mechanisms of ER stress in hepatic lipotoxicity. Understanding the role of ER stress in hepatic metabolism may lead to the identification of new therapeutic targets for metabolic diseases.

  2. Endoplasmic Reticulum (ER) Stress and Endocrine Disorders.

    Science.gov (United States)

    Ariyasu, Daisuke; Yoshida, Hiderou; Hasegawa, Yukihiro

    2017-02-11

    The endoplasmic reticulum (ER) is the organelle where secretory and membrane proteins are synthesized and folded. Unfolded proteins that are retained within the ER can cause ER stress. Eukaryotic cells have a defense system called the "unfolded protein response" (UPR), which protects cells from ER stress. Cells undergo apoptosis when ER stress exceeds the capacity of the UPR, which has been revealed to cause human diseases. Although neurodegenerative diseases are well-known ER stress-related diseases, it has been discovered that endocrine diseases are also related to ER stress. In this review, we focus on ER stress-related human endocrine disorders. In addition to diabetes mellitus, which is well characterized, several relatively rare genetic disorders such as familial neurohypophyseal diabetes insipidus (FNDI), Wolfram syndrome, and isolated growth hormone deficiency type II (IGHD2) are discussed in this article.

  3. Endoplasmic Reticulum (ER Stress and Endocrine Disorders

    Directory of Open Access Journals (Sweden)

    Daisuke Ariyasu

    2017-02-01

    Full Text Available The endoplasmic reticulum (ER is the organelle where secretory and membrane proteins are synthesized and folded. Unfolded proteins that are retained within the ER can cause ER stress. Eukaryotic cells have a defense system called the “unfolded protein response” (UPR, which protects cells from ER stress. Cells undergo apoptosis when ER stress exceeds the capacity of the UPR, which has been revealed to cause human diseases. Although neurodegenerative diseases are well-known ER stress-related diseases, it has been discovered that endocrine diseases are also related to ER stress. In this review, we focus on ER stress-related human endocrine disorders. In addition to diabetes mellitus, which is well characterized, several relatively rare genetic disorders such as familial neurohypophyseal diabetes insipidus (FNDI, Wolfram syndrome, and isolated growth hormone deficiency type II (IGHD2 are discussed in this article.

  4. ER Stress and Lipid Metabolism in Adipocytes

    Directory of Open Access Journals (Sweden)

    Beth S. Zha

    2012-01-01

    Full Text Available The role of endoplasmic reticulum (ER stress is a rapidly emerging field of interest in the pathogenesis of metabolic diseases. Recent studies have shown that chronic activation of ER stress is closely linked to dysregulation of lipid metabolism in several metabolically important cells including hepatocytes, macrophages, β-cells, and adipocytes. Adipocytes are one of the major cell types involved in the pathogenesis of the metabolic syndrome. Recent advances in dissecting the cellular and molecular mechanisms involved in the regulation of adipogenesis and lipid metabolism indicate that activation of ER stress plays a central role in regulating adipocyte function. In this paper, we discuss the current understanding of the potential role of ER stress in lipid metabolism in adipocytes. In addition, we touch upon the interaction of ER stress and autophagy as well as inflammation. Inhibition of ER stress has the potential of decreasing the pathology in adipose tissue that is seen with energy overbalance.

  5. ER stress, autophagy, and RNA viruses

    Directory of Open Access Journals (Sweden)

    Jia-Rong eJheng

    2014-08-01

    Full Text Available Endoplasmic reticulum (ER stress is a general term for representing the pathway by which various stimuli affect ER functions. ER stress induces the evolutionarily conserved signaling pathways, called the unfolded protein response (UPR, which compromises the stimulus and then determines whether the cell survives or dies. In recent years, ongoing research has suggested that these pathways may be linked to the autophagic response, which plays a key role in the cell’s response to various stressors. Autophagy performs a self-digestion function, and its activation protects cells against certain pathogens. However, the link between the UPR and autophagy may be more complicated. These two systems may act dependently, or the induction of one system may interfere with the other. Experimental studies have found that different viruses modulate these mechanisms to allow them to escape the host immune response or, worse, to exploit the host’s defense to their advantage; thus, this topic is a critical area in antiviral research. In this review, we summarize the current knowledge about how RNA viruses, including influenza virus, poliovirus, coxsackievirus, enterovirus 71, Japanese encephalitis virus, hepatitis C virus, and dengue virus, regulate these processes. We also discuss recent discoveries and how these will produce novel strategies for antiviral treatment.

  6. Endoplasmic reticulum: ER stress regulates mitochondrial bioenergetics

    Science.gov (United States)

    Bravo, Roberto; Gutierrez, Tomás; Paredes, Felipe; Gatica, Damián; Rodriguez, Andrea E.; Pedrozo, Zully; Chiong, Mario; Parra, Valentina; Quest, Andrew F.G.; Rothermel, Beverly A.; Lavandero, Sergio

    2014-01-01

    Endoplasmic reticulum (ER) stress activates an adaptive unfolded protein response (UPR) that facilitates cellular repair, however, under prolonged ER stress, the UPR can ultimately trigger apoptosis thereby terminating damaged cells. The molecular mechanisms responsible for execution of the cell death program are relatively well characterized, but the metabolic events taking place during the adaptive phase of ER stress remain largely undefined. Here we discuss emerging evidence regarding the metabolic changes that occur during the onset of ER stress and how ER influences mitochondrial function through mechanisms involving calcium transfer, thereby facilitating cellular adaptation. Finally, we highlight how dysregulation of ER–mitochondrial calcium homeostasis during prolonged ER stress is emerging as a novel mechanism implicated in the onset of metabolic disorders. PMID:22064245

  7. Sigma-1 receptor chaperone at the ER-mitochondrion interface mediates the mitochondrion-ER-nucleus signaling for cellular survival.

    Science.gov (United States)

    Mori, Tomohisa; Hayashi, Teruo; Hayashi, Eri; Su, Tsung-Ping

    2013-01-01

    The membrane of the endoplasmic reticulum (ER) of a cell forms contacts directly with mitochondria whereby the contact is referred to as the mitochondrion-associated ER membrane or the MAM. Here we found that the MAM regulates cellular survival via an MAM-residing ER chaperone the sigma-1 receptor (Sig-1R) in that the Sig-1R chaperones the ER stress sensor IRE1 to facilitate inter-organelle signaling for survival. IRE1 is found in this study to be enriched at the MAM in CHO cells. We found that IRE1 is stabilized at the MAM by Sig-1Rs when cells are under ER stress. Sig-1Rs stabilize IRE1 and thus allow for conformationally correct IRE1 to dimerize into the long-lasting, activated endonuclease. The IRE1 at the MAM also responds to reactive oxygen species derived from mitochondria. Therefore, the ER-mitochondrion interface serves as an important subcellular entity in the regulation of cellular survival by enhancing the stress-responding signaling between mitochondria, ER, and nucleus.

  8. Mitochondria-Associated Membranes and ER Stress.

    Science.gov (United States)

    van Vliet, Alexander R; Agostinis, Patrizia

    2017-03-28

    The endoplasmic reticulum (ER) is a crucial organelle for coordinating cellular Ca(2+) signaling and protein synthesis and folding. Moreover, the dynamic and complex membranous structures constituting the ER allow the formation of contact sites with other organelles and structures, including among others the mitochondria and the plasma membrane (PM). The contact sites that the ER form with mitochondria is a hot topic in research, and the nature of the so-called mitochondria-associated membranes (MAMs) is continuously evolving. The MAMs consist of a proteinaceous tether that physically connects the ER with mitochondria. The MAMs harness the main functions of both organelles to form a specialized subcompartment at the interface of the ER and mitochondria. Under homeostatic conditions, MAMs are crucial for the efficient transfer of Ca(2+) from the ER to mitochondria, and for proper mitochondria bioenergetics and lipid synthesis. MAMs are also believed to be the master regulators of mitochondrial shape and motility, and to form a crucial site for autophagosome assembly. Not surprisingly, MAMs have been shown to be a hot spot for the transfer of stress signals from the ER to mitochondria, most notably under the conditions of loss of ER proteostasis, by engaging the unfolded protein response (UPR). In this chapter after an introduction on ER biology and ER stress, we will review the emerging and key signaling roles of the MAMs, which have a root in cellular processes and signaling cascades coordinated by the ER.

  9. The genetic architecture of the genome-wide transcriptional response to ER stress in the mouse.

    Directory of Open Access Journals (Sweden)

    Clement Y Chow

    2015-02-01

    Full Text Available Endoplasmic reticulum (ER stress occurs when misfolded proteins accumulate in the ER. The cellular response to ER stress involves complex transcriptional and translational changes, important to the survival of the cell. ER stress is a primary cause and a modifier of many human diseases. A first step to understanding how the ER stress response impacts human disease is to determine how the transcriptional response to ER stress varies among individuals. The genetic diversity of the eight mouse Collaborative Cross (CC founder strains allowed us to determine how genetic variation impacts the ER stress transcriptional response. We used tunicamycin, a drug commonly used to induce ER stress, to elicit an ER stress response in mouse embryonic fibroblasts (MEFs derived from the CC founder strains and measured their transcriptional responses. We identified hundreds of genes that differed in response to ER stress across these genetically diverse strains. Strikingly, inflammatory response genes differed most between strains; major canonical ER stress response genes showed relatively invariant responses across strains. To uncover the genetic architecture underlying these strain differences in ER stress response, we measured the transcriptional response to ER stress in MEFs derived from a subset of F1 crosses between the CC founder strains. We found a unique layer of regulatory variation that is only detectable under ER stress conditions. Over 80% of the regulatory variation under ER stress derives from cis-regulatory differences. This is the first study to characterize the genetic variation in ER stress transcriptional response in the laboratory mouse. Our findings indicate that the ER stress transcriptional response is highly variable among strains and arises from genetic variation in individual downstream response genes, rather than major signaling transcription factors. These results have important implications for understanding how genetic variation

  10. Coronavirus infection, ER stress and Apoptosis

    Directory of Open Access Journals (Sweden)

    TO SING eFUNG

    2014-06-01

    Full Text Available The replication of coronavirus, a family of important animal and human pathogens, is closely associated with the cellular membrane compartments, especially the endoplasmic reticulum (ER. Coronavirus infection of cultured cells was previously shown to cause ER stress and induce the unfolded protein response (UPR, a process that aims to restore the ER homeostasis by global translation shutdown and increasing the ER folding capacity. However under prolonged ER stress, UPR can also induce apoptotic cell death. Accumulating evidence from recent studies has shown that induction of ER stress and UPR may constitute a major aspect of coronavirus-host interaction. Activation of the three branches of UPR modulates a wide variety of signaling pathways, such as mitogen-activated protein (MAP kinases activation, autophagy, apoptosis and innate immune response. ER stress and UPR activation may therefore contribute significantly to the viral replication and pathogenesis during coronavirus infection. In this review, we summarize current knowledge on coronavirus-induced ER stress and UPR activation, with emphasis on their cross-talking to apoptotic signaling.

  11. The role of ER stress in lipid metabolism and lipotoxicity.

    Science.gov (United States)

    Han, Jaeseok; Kaufman, Randal J

    2016-08-01

    The endoplasmic reticulum (ER) is a cellular organelle important for regulating calcium homeostasis, lipid metabolism, protein synthesis, and posttranslational modification and trafficking. Numerous environmental, physiological, and pathological insults disturb ER homeostasis, referred to as ER stress, in which a collection of conserved intracellular signaling pathways, termed the unfolded protein response (UPR), are activated to maintain ER function for cell survival. However, excessive and/or prolonged UPR activation leads to initiation of self-destruction through apoptosis. Excessive accumulation of lipids and their intermediate products causes metabolic abnormalities and cell death, called lipotoxicity, in peripheral organs, including the pancreatic islets, liver, muscle, and heart. Because accumulating evidence links chronic ER stress and defects in UPR signaling to lipotoxicity in peripheral tissues, understanding the role of ER stress in cell physiology is a topic under intense investigation. In this review, we highlight recent findings that link ER stress and UPR signaling to the pathogenesis of peripheral organs due to lipotoxicity. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

  12. Arctigenin alleviates ER stress via activating AMPK

    Science.gov (United States)

    Gu, Yuan; Sun, Xiao-xiao; Ye, Ji-ming; He, Li; Yan, Shou-sheng; Zhang, Hao-hao; Hu, Li-hong; Yuan, Jun-ying; Yu, Qiang

    2012-01-01

    Aim: To investigate the protective effects of arctigenin (ATG), a phenylpropanoid dibenzylbutyrolactone lignan from Arctium lappa L (Compositae), against ER stress in vitro and the underlying mechanisms. Methods: A cell-based screening assay for ER stress regulators was established. Cell viability was measured using MTT assay. PCR and Western blotting were used to analyze gene and protein expression. Silencing of the CaMKKβ, LKB1, and AMPKα1 genes was achieved by RNA interference (RNAi). An ATP bioluminescent assay kit was employed to measure the intracellular ATP levels. Results: ATG (2.5, 5 and 10 μmol/L) inhibited cell death and unfolded protein response (UPR) in a concentration-dependent manner in cells treated with the ER stress inducer brefeldin A (100 nmol/L). ATG (1, 5 and 10 μmol/L) significantly attenuated protein synthesis in cells through inhibiting mTOR-p70S6K signaling and eEF2 activity, which were partially reversed by silencing AMPKα1 with RNAi. ATG (1-50 μmol/L) reduced intracellular ATP level and activated AMPK through inhibiting complex I-mediated respiration. Pretreatment of cells with the AMPK inhibitor compound C (25 μmol/L) rescued the inhibitory effects of ATG on ER stress. Furthermore, ATG (2.5 and 5 μmol/L) efficiently activated AMPK and reduced the ER stress and cell death induced by palmitate (2 mmol/L) in INS-1 β cells. Conclusion: ATG is an effective ER stress alleviator, which protects cells against ER stress through activating AMPK, thus attenuating protein translation and reducing ER load. PMID:22705729

  13. Developing ER Stress Inhibitors for Treating ALS

    Science.gov (United States)

    2015-11-01

    in response to thapsigargin, an inhibitor of the sarco/endoplasmic reticulum Ca2+ ATPase ( SERCA ) channels which initiates ER stress by preventing...O’Regan, J. P., Deng, H. X., and et al. (1993) Mutations in Cu/Zn superoxide dismutase gene are associated with familial amyotrophic lateral

  14. Induction of ER stress in macrophages of tuberculosis granulomas.

    Directory of Open Access Journals (Sweden)

    Tracie A Seimon

    2010-09-01

    Full Text Available The endoplasmic reticulum (ER stress pathway known as the Unfolded Protein Response (UPR is an adaptive survival pathway that protects cells from the buildup of misfolded proteins, but under certain circumstances it can lead to apoptosis. ER stress has been causally associated with macrophage apoptosis in advanced atherosclerosis of mice and humans. Because atherosclerosis shares certain features with tuberculosis (TB with regard to lesional macrophage accumulation, foam cell formation, and apoptosis, we investigated if the ER stress pathway is activated during TB infection.Here we show that ER stress markers such as C/EBP homologous protein (CHOP; also known as GADD153, phosphorylated inositol-requiring enzyme 1 alpha (Ire1α and eukaryotic initiation factor 2 alpha (eIF2α, and activating transcription factor 3 (ATF3 are expressed in macrophage-rich areas of granulomas in lungs of mice infected with virulent Mycobacterium tuberculosis (Mtb. These areas were also positive for numerous apoptotic cells as assayed by TUNEL. Microarray analysis of human caseous TB granulomas isolated by laser capture microdissection reveal that 73% of genes involved in the UPR are upregulated at the mRNA transcript level. The expression of two ER stress markers, ATF3 and CHOP, were also increased in macrophages of human TB granulomas when assayed by immunohistochemistry. CHOP has been causally associated with ER stress-induced macrophage apoptosis. We found that apoptosis was more abundant in granulomas as compared to non-granulomatous tissue isolated from patients with pulmonary TB, and apoptosis correlated with CHOP expression in areas surrounding the centralized areas of caseation.In summary, ER stress is induced in macrophages of TB granulomas in areas where apoptotic cells accumulate in mice and humans. Although macrophage apoptosis is generally thought to be beneficial in initially protecting the host from Mtb infection, death of infected macrophages in

  15. The chlamydial organism Simkania negevensis forms ER vacuole contact sites and inhibits ER-stress.

    Science.gov (United States)

    Mehlitz, Adrian; Karunakaran, Karthika; Herweg, Jo-Ana; Krohne, Georg; van de Linde, Sebastian; Rieck, Elke; Sauer, Markus; Rudel, Thomas

    2014-08-01

    Most intracellular bacterial pathogens reside within membrane-surrounded host-derived vacuoles. Few of these bacteria exploit membranes from the host's endoplasmic reticulum (ER) to form a replicative vacuole. Here, we describe the formation of ER-vacuole contact sites as part of the replicative niche of the chlamydial organism Simkania negevensis. Formation of ER-vacuole contact sites is evolutionary conserved in the distantly related protozoan host Acanthamoeba castellanii. Simkania growth is accompanied by mitochondria associating with the Simkania-containing vacuole (SCV). Super-resolution microscopy as well as 3D reconstruction from electron micrographs of serial ultra-thin sections revealed a single vacuolar system forming extensive ER-SCV contact sites on the Simkania vacuolar surface. Simkania infection induced an ER-stress response, which was later downregulated. Induction of ER-stress with Thapsigargin or Tunicamycin was strongly inhibited in cells infected with Simkania. Inhibition of ER-stress was required for inclusion formation and efficient growth, demonstrating a role of ER-stress in the control of Simkania infection. Thus, Simkania forms extensive ER-SCV contact sites in host species evolutionary as diverse as human and amoeba. Moreover, Simkania is the first bacterial pathogen described to interfere with ER-stress induced signalling to promote infection. © 2014 John Wiley & Sons Ltd.

  16. Linking ER Stress to Autophagy: Potential Implications for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Tom Verfaillie

    2010-01-01

    Full Text Available Different physiological and pathological conditions can perturb protein folding in the endoplasmic reticulum, leading to a condition known as ER stress. ER stress activates a complex intracellular signal transduction pathway, called unfolded protein response (UPR. The UPR is tailored essentially to reestablish ER homeostasis also through adaptive mechanisms involving the stimulation of autophagy. However, when persistent, ER stress can switch the cytoprotective functions of UPR and autophagy into cell death promoting mechanisms. Recently, a variety of anticancer therapies have been linked to the induction of ER stress in cancer cells, suggesting that strategies devised to stimulate its prodeath function or block its prosurvival function, could be envisaged to improve their tumoricidial action. A better understanding of the molecular mechanisms that determine the final outcome of UPR and autophagy activation by chemotherapeutic agents, will offer new opportunities to improve existing cancer therapies as well as unravel novel targets for cancer treatment.

  17. Mechanisms of ER Stress-Mediated Mitochondrial Membrane Permeabilization.

    LENUS (Irish Health Repository)

    Gupta, Sanjeev

    2010-01-01

    During apoptosis, the process of mitochondrial outer membrane permeabilization (MOMP) represents a point-of-no-return as it commits the cell to death. Here we have assessed the role of caspases, Bcl-2 family members and the mitochondrial permeability transition pore on ER stress-induced MOMP and subsequent cell death. Induction of ER stress leads to upregulation of several genes such as Grp78, Edem1, Erp72, Atf4, Wars, Herp, p58ipk, and ERdj4 and leads to caspase activation, release of mitochondrial intermembrane proteins and dissipation of mitochondrial transmembrane potential (DeltaPsim). Mouse embryonic fibroblasts (MEFs) from caspase-9, -2 and, -3 knock-out mice were resistant to ER stress-induced apoptosis which correlated with decreased processing of pro-caspase-3 and -9. Furthermore, pretreatment of cells with caspase inhibitors (Boc-D.fmk and DEVD.fmk) attenuated ER stress-induced loss of DeltaPsim. However, only deficiency of caspase-9 and -2 could prevent ER stress-mediated loss of DeltaPsim. Bcl-2 overexpression or pretreatment of cells with the cell permeable BH4 domain (BH4-Tat) or the mitochondrial permeability transition pore inhibitors, bongkrekic acid or cyclosporine A, attenuated the ER stress-induced loss of DeltaPsim. These data suggest a role for caspase-9 and -2, Bcl-2 family members and the mitochondrial permeability transition pore in loss of mitochondrial membrane potential during ER stress-induced apoptosis.

  18. Coronavirus infection, ER stress, apoptosis and innate immunity

    Science.gov (United States)

    Fung, To S.; Liu, Ding X.

    2014-01-01

    The replication of coronavirus, a family of important animal and human pathogens, is closely associated with the cellular membrane compartments, especially the endoplasmic reticulum (ER). Coronavirus infection of cultured cells was previously shown to cause ER stress and induce the unfolded protein response (UPR), a process that aims to restore the ER homeostasis by global translation shutdown and increasing the ER folding capacity. However, under prolonged ER stress, UPR can also induce apoptotic cell death. Accumulating evidence from recent studies has shown that induction of ER stress and UPR may constitute a major aspect of coronavirus–host interaction. Activation of the three branches of UPR modulates a wide variety of signaling pathways, such as mitogen-activated protein (MAP) kinase activation, autophagy, apoptosis, and innate immune response. ER stress and UPR activation may therefore contribute significantly to the viral replication and pathogenesis during coronavirus infection. In this review, we summarize the current knowledge on coronavirus-induced ER stress and UPR activation, with emphasis on their cross-talking to apoptotic signaling. PMID:24987391

  19. Metformin attenuates ER stress-induced mitochondrial dysfunction.

    Science.gov (United States)

    Chen, Qun; Thompson, Jeremy; Hu, Ying; Das, Anindita; Lesnefsky, Edward J

    2017-12-01

    Endoplasmic reticulum (ER) stress, a disturbance of the ER function, contributes to cardiac injury. ER and mitochondria are closely connected organelles within cells. ER stress contributes to mitochondrial dysfunction, which is a key factor to increase cardiac injury. Metformin, a traditional anti-diabetic drug, decreases cardiac injury during ischemia-reperfusion. Metformin also inhibits ER stress in cultured cells. We hypothesized that metformin can attenuate the ER stress-induced mitochondrial dysfunction and subsequent cardiac injury. Thapsigargin (THAP, 3 mg/kg) was used to induce ER stress in C57BL/6 mice. Cell injury and mitochondrial function were evaluated in the mouse heart 48 hours after 1-time THAP treatment. Metformin was dissolved in drinking water (0.5 g/250 ml) and fed to mice for 7 days before THAP injection. Metformin feeding continued after THAP treatment. THAP treatment increased apoptosis in mouse myocardium compared to control. THAP also led to decreased oxidative phosphorylation in heart mitochondria-oxidizing complex I substrates. THAP decreased the calcium retention capacity, indicating that ER stress sensitizes mitochondria to mitochondrial permeability transition pore opening. The cytosolic C/EBP homologous protein (CHOP) content was markedly increased in THAP-treated hearts compared to control, particularly in the nucleus. Metformin prevented the THAP-induced mitochondrial dysfunction and reduced CHOP content in cytosol and nucleus. Thus, metformin reduces cardiac injury during ER stress through the protection of cardiac mitochondria and attenuation of CHOP expression. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. ER Dysfunction and Protein Folding Stress in ALS

    Science.gov (United States)

    Matus, Soledad; Valenzuela, Vicente; Medinas, Danilo B.; Hetz, Claudio

    2013-01-01

    Amyotrophic lateral sclerosis (ALS) is the most frequent paralytic disease in adults. Most ALS cases are considered sporadic with no clear genetic component. The disruption of protein homeostasis due to chronic stress responses at the endoplasmic reticulum (ER) and the accumulation of abnormal protein inclusions are extensively described in ALS mouse models and patient-derived tissue. Recent studies using pharmacological and genetic manipulation of the unfolded protein response (UPR), an adaptive reaction against ER stress, have demonstrated a complex involvement of the pathway in experimental models of ALS. In addition, quantitative changes in ER stress-responsive chaperones in body fluids have been proposed as possible biomarkers to monitor the disease progression. Here we review most recent advances attributing a causal role of ER stress in ALS. PMID:24324498

  1. ER Stress-Mediated Signaling: Action Potential and Ca(2+) as Key Players.

    Science.gov (United States)

    Bahar, Entaz; Kim, Hyongsuk; Yoon, Hyonok

    2016-09-15

    The proper functioning of the endoplasmic reticulum (ER) is crucial for multiple cellular activities and survival. Disturbances in the normal ER functions lead to the accumulation and aggregation of unfolded proteins, which initiates an adaptive response, the unfolded protein response (UPR), in order to regain normal ER functions. Failure to activate the adaptive response initiates the process of programmed cell death or apoptosis. Apoptosis plays an important role in cell elimination, which is essential for embryogenesis, development, and tissue homeostasis. Impaired apoptosis can lead to the development of various pathological conditions, such as neurodegenerative and autoimmune diseases, cancer, or acquired immune deficiency syndrome (AIDS). Calcium (Ca(2+)) is one of the key regulators of cell survival and it can induce ER stress-mediated apoptosis in response to various conditions. Ca(2+) regulates cell death both at the early and late stages of apoptosis. Severe Ca(2+) dysregulation can promote cell death through apoptosis. Action potential, an electrical signal transmitted along the neurons and muscle fibers, is important for conveying information to, from, and within the brain. Upon the initiation of the action potential, increased levels of cytosolic Ca(2+) (depolarization) lead to the activation of the ER stress response involved in the initiation of apoptosis. In this review, we discuss the involvement of Ca(2+) and action potential in ER stress-mediated apoptosis.

  2. ER Stress-Mediated Signaling: Action Potential and Ca2+ as Key Players

    Science.gov (United States)

    Bahar, Entaz; Kim, Hyongsuk; Yoon, Hyonok

    2016-01-01

    The proper functioning of the endoplasmic reticulum (ER) is crucial for multiple cellular activities and survival. Disturbances in the normal ER functions lead to the accumulation and aggregation of unfolded proteins, which initiates an adaptive response, the unfolded protein response (UPR), in order to regain normal ER functions. Failure to activate the adaptive response initiates the process of programmed cell death or apoptosis. Apoptosis plays an important role in cell elimination, which is essential for embryogenesis, development, and tissue homeostasis. Impaired apoptosis can lead to the development of various pathological conditions, such as neurodegenerative and autoimmune diseases, cancer, or acquired immune deficiency syndrome (AIDS). Calcium (Ca2+) is one of the key regulators of cell survival and it can induce ER stress-mediated apoptosis in response to various conditions. Ca2+ regulates cell death both at the early and late stages of apoptosis. Severe Ca2+ dysregulation can promote cell death through apoptosis. Action potential, an electrical signal transmitted along the neurons and muscle fibers, is important for conveying information to, from, and within the brain. Upon the initiation of the action potential, increased levels of cytosolic Ca2+ (depolarization) lead to the activation of the ER stress response involved in the initiation of apoptosis. In this review, we discuss the involvement of Ca2+ and action potential in ER stress-mediated apoptosis. PMID:27649160

  3. Hippocampal ER stress and learning deficits following repeated pyrethroid exposure.

    Science.gov (United States)

    Hossain, Muhammad M; DiCicco-Bloom, Emanuel; Richardson, Jason R

    2015-01-01

    Endoplasmic reticulum (ER) stress is implicated as a significant contributor to neurodegeneration and cognitive dysfunction. Previously, we reported that the widely used pyrethroid pesticide deltamethrin causes ER stress-mediated apoptosis in SK-N-AS neuroblastoma cells. Whether or not this occurs in vivo remains unknown. Here, we demonstrate that repeated deltamethrin exposure (3 mg/kg every 3 days for 60 days) causes hippocampal ER stress and learning deficits in adult mice. Repeated exposure to deltamethrin caused ER stress in the hippocampus as indicated by increased levels of C/EBP-homologous protein (131%) and glucose-regulated protein 78 (96%). This was accompanied by increased levels of caspase-12 (110%) and activated caspase-3 (50%). To determine whether these effects resulted in learning deficits, hippocampal-dependent learning was evaluated using the Morris water maze. Deltamethrin-treated animals exhibited profound deficits in the acquisition of learning. We also found that deltamethrin exposure resulted in decreased BrdU-positive cells (37%) in the dentate gyrus of the hippocampus, suggesting potential impairment of hippocampal neurogenesis. Collectively, these results demonstrate that repeated deltamethrin exposure leads to ER stress, apoptotic cell death in the hippocampus, and deficits in hippocampal precursor proliferation, which is associated with learning deficits. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Endoplasmic reticulum (ER) Ca2+-channel activity contributes to ER stress and cone death in cyclic nucleotide-gated channel deficiency.

    Science.gov (United States)

    Butler, Michael R; Ma, Hongwei; Yang, Fan; Belcher, Joshua; Le, Yun-Zheng; Mikoshiba, Katsuhiko; Biel, Martin; Michalakis, Stylianos; Iuso, Anthony; Križaj, David; Ding, Xi-Qin

    2017-07-07

    Endoplasmic reticulum (ER) stress and mislocalization of improperly folded proteins have been shown to contribute to photoreceptor death in models of inherited retinal degenerative diseases. In particular, mice with cone cyclic nucleotide-gated (CNG) channel deficiency, a model for achromatopsia, display both early-onset ER stress and opsin mistrafficking. By 2 weeks of age, these mice show elevated signaling from all three arms of the ER-stress pathway, and by 1 month, cone opsin is improperly distributed away from its normal outer segment location to other retinal layers. This work investigated the role of Ca2+-release channels in ER stress, protein mislocalization, and cone death in a mouse model of CNG-channel deficiency. We examined whether preservation of luminal Ca2+ stores through pharmacological and genetic suppression of ER Ca2+ efflux protects cones by attenuating ER stress. We demonstrated that the inhibition of ER Ca2+-efflux channels reduced all three arms of ER-stress signaling while improving opsin trafficking to cone outer segments and decreasing cone death by 20-35%. Cone-specific gene deletion of the inositol-1,4,5-trisphosphate receptor type I (IP3R1) also significantly increased cone density in the CNG-channel-deficient mice, suggesting that IP3R1 signaling contributes to Ca2+ homeostasis and cone survival. Consistent with the important contribution of organellar Ca2+ signaling in this achromatopsia mouse model, significant differences in dynamic intraorganellar Ca2+ levels were detected in CNG-channel-deficient cones. These results thus identify a novel molecular link between Ca2+ homeostasis and cone degeneration, thereby revealing novel therapeutic targets to preserve cones in inherited retinal degenerative diseases. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Calcium homeostasis and ER stress in control of autophagy in cancer cells.

    Science.gov (United States)

    Kania, Elżbieta; Pająk, Beata; Orzechowski, Arkadiusz

    2015-01-01

    Autophagy is a basic catabolic process, serving as an internal engine during responses to various cellular stresses. As regards cancer, autophagy may play a tumor suppressive role by preserving cellular integrity during tumor development and by possible contribution to cell death. However, autophagy may also exert oncogenic effects by promoting tumor cell survival and preventing cell death, for example, upon anticancer treatment. The major factors influencing autophagy are Ca(2+) homeostasis perturbation and starvation. Several Ca(2+) channels like voltage-gated T- and L-type channels, IP3 receptors, or CRAC are involved in autophagy regulation. Glucose transporters, mainly from GLUT family, which are often upregulated in cancer, are also prominent targets for autophagy induction. Signals from both Ca(2+) perturbations and glucose transport blockage might be integrated at UPR and ER stress activation. Molecular pathways such as IRE 1-JNK-Bcl-2, PERK-eIF2α-ATF4, or ATF6-XBP 1-ATG are related to autophagy induced through ER stress. Moreover ER molecular chaperones such as GRP78/BiP and transcription factors like CHOP participate in regulation of ER stress-mediated autophagy. Autophagy modulation might be promising in anticancer therapies; however, it is a context-dependent matter whether inhibition or activation of autophagy leads to tumor cell death.

  6. Calcium Homeostasis and ER Stress in Control of Autophagy in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Elżbieta Kania

    2015-01-01

    Full Text Available Autophagy is a basic catabolic process, serving as an internal engine during responses to various cellular stresses. As regards cancer, autophagy may play a tumor suppressive role by preserving cellular integrity during tumor development and by possible contribution to cell death. However, autophagy may also exert oncogenic effects by promoting tumor cell survival and preventing cell death, for example, upon anticancer treatment. The major factors influencing autophagy are Ca2+ homeostasis perturbation and starvation. Several Ca2+ channels like voltage-gated T- and L-type channels, IP3 receptors, or CRAC are involved in autophagy regulation. Glucose transporters, mainly from GLUT family, which are often upregulated in cancer, are also prominent targets for autophagy induction. Signals from both Ca2+ perturbations and glucose transport blockage might be integrated at UPR and ER stress activation. Molecular pathways such as IRE 1-JNK-Bcl-2, PERK-eIF2α-ATF4, or ATF6-XBP 1-ATG are related to autophagy induced through ER stress. Moreover ER molecular chaperones such as GRP78/BiP and transcription factors like CHOP participate in regulation of ER stress-mediated autophagy. Autophagy modulation might be promising in anticancer therapies; however, it is a context-dependent matter whether inhibition or activation of autophagy leads to tumor cell death.

  7. AAV delivery of GRP78/BiP promotes adaptation of human RPE cell to ER stress.

    Science.gov (United States)

    Ghaderi, Shima; Ahmadian, Shahin; Soheili, Zahra-Soheila; Ahmadieh, Hamid; Samiei, Shahram; Kheitan, Samira; Pirmardan, Ehsan R

    2017-08-07

    Adeno associated virus (AAV)-mediated gene delivery of GRP78 (78 kDa glucose-regulated protein) attenuates the condition of endoplasmic reticulum (ER) stress and prevents apoptotic loss of photoreceptors in Retinitis pigmentosa (RP) rats. In the current study we overexpressed Grp78 with the help of AAV-2 in primary human retinal pigmented epithelium (hRPE) cell cultures and examined its effect on cell response to ER stress. The purpose of this work was studying potential stimulating effect of GRP78 on adaptation/pro-survival of hRPE cells under ER stress, as an in vitro model for RPE degeneration. To investigate the effect of Grp78 overexpression on unfolded protein response (UPR) markers under ER stress, hRPE primary cultures were transduced by recombinant virus rAAV/Grp78, and treated with ER stressor drug, tunicamycin. Expression changes of four UPR markers including GRP78, PERK, ATF6α, and GADD153/CHOP, were assessed by real-time PCR and western blotting. We found that GRP78 has a great contribution in modulation of UPR markers to favor adaptive response in ER-stressed hRPE cells. In fact, GRP78 overexpression affected adaptation and apoptotic phases of early UPR, through enhancement of two master regulators/ER stress sensors (PERK and ATF6α) and down-regulation of a key pro-apoptotic cascade activator (GADD153/CHOP). Together these findings demonstrate the promoting effect of GRP78 on adaptation/pro-survival of hRPE cells under ER stress. This protein with anti-apoptotic actions in the early UPR and important role in cell fate regulation, can be recruited as a useful candidate for future investigations of RPE degenerative diseases. © 2017 Wiley Periodicals, Inc.

  8. Stress sensing in plants by the ER stress sensor/transducer, bZIP28

    Directory of Open Access Journals (Sweden)

    Renu eSrivastava

    2014-02-01

    Full Text Available Two classes of ER stress sensors are known in plants, membrane associated bZIP transcription factors and RNA splicing factors. ER stress occurs under adverse environmental conditions and results from the accumulation of misfolded or unfolded proteins in the ER lumen. One of the membrane-associated transcription factors activated by heat and ER stress agents is bZIP28. In its inactive form, bZIP28 is a type II protein with a single pass transmembrane domain, residing in the ER. bZIP28’s N-terminus, containing a transcriptional activation domain, is oriented towards the cytoplasm and its C-terminal tail is inserted into the ER lumen. In response to stress, bZIP28 exits the ER and moves to the Golgi where it is proteolytically processed, liberating its cytosolic component which relocates to the nucleus to upregulate stress-response genes. bZIP28 is thought to sense stress through its interaction with the major ER chaperone, BIP. BiP binds to bZIP28’s lumenal domain under unstressed conditions and retains it in the ER. BIP binds to the intrinsically disordered regions on bZIP28’s lumen-facing tail. A truncated form of bZIP28, without its C-terminal tail is not retained in the ER but migrates constitutively to the nucleus. Upon stress, BiP releases bZIP28 allowing it to exit the ER. One model to account for the release of bZIP28 by BiP is that BiP is competed away from bZIP28 by the accumulation of misfolded proteins in the ER. However, other forces such as changes in energy charge levels, redox conditions or interaction with DNAJ proteins may also promote release of bZIP28 from BiP. Movement of bZIP28 from the ER to the Golgi is assisted by the interaction of elements of the COPII machinery with the cytoplasmic domain of bZIP28. Thus, the mobilization of bZIP28 in response to stress involves the dissociation of factors that retain it in the ER and the association of factors that mediate its further organelle-to-organelle movement.

  9. Aberrant accumulation of the diabetes autoantigen GAD65 in Golgi membranes in conditions of ER stress and autoimmunity

    DEFF Research Database (Denmark)

    Phelps, Edward A; Cianciaruso, Chiara; Michael, Iacovos P

    2016-01-01

    Pancreatic islet beta cells are particularly susceptible to endoplasmic reticulum (ER) stress, which is implicated in beta cell dysfunction and loss during the pathogenesis of type 1 diabetes (T1D). The peripheral membrane protein GAD65 is an autoantigen in human T1D. GAD65 synthesizes GABA......, an important autocrine and paracrine signaling molecule and a survival factor in islets. We show that ER stress in primary beta cells perturbs the palmitoylation cycle controlling GAD65 endomembrane distribution, resulting in aberrant accumulation of the palmitoylated form in trans-Golgi membranes...... release from stressed and/or damaged beta cells, triggering autoimmunity....

  10. A review of endoplasmic reticulum (ER) stress and nanoparticle (NP) exposure.

    Science.gov (United States)

    Cao, Yi; Long, Jimin; Liu, Liangliang; He, Tong; Jiang, Leying; Zhao, Chunxue; Li, Zhen

    2017-10-01

    Understanding the mechanism of nanoparticle (NP) induced toxicity is important for nanotoxicological and nanomedicinal studies. Endoplasmic reticulum (ER) is a crucial organelle involved in proper protein folding. High levels of misfolded proteins in the ER could lead to a condition termed as ER stress, which may ultimately influence the fate of cells and development of human diseases. In this review, we summarized studies about effects of NP exposure on ER stress. A variety of NPs, especially metal-based NPs, could induce morphological changes of ER and activate ER stress pathway both in vivo and in vitro. In addition, modulation of ER stress by chemicals has been shown to alter the toxicity of NPs. These studies in combination suggested that ER stress could be the mechanism responsible for NP induced toxicity. Meanwhile, nanomedicinal studies also used ER stress inducing NPs or NPs loaded with ER stress inducer to selectively induce ER stress mediated apoptosis in cancer cells for cancer therapy. In contrast, alleviation of ER stress by NPs has also been shown as a strategy to cure metabolic diseases. In conclusion, exposure to NPs may modulate ER stress, which could be a target for future nanotoxicological and nanomedicinal studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. ER stress-induced protein, VIGG, disturbs plant cation homeostasis, which is correlated with growth retardation and robustness to ER stress

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Hironori; Fujita, Keiko; Takuhara, Yuki [Laboratory of Fruit Genetic Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Kofu, Yamanashi 400-0005 (Japan); Ogawa, Atsushi [Department of Biological Production, Akita Prefectural University, Shimosinjyou-nakano 241-438, Akita 010-0195 (Japan); Suzuki, Shunji, E-mail: suzukis@yamanashi.ac.jp [Laboratory of Fruit Genetic Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Kofu, Yamanashi 400-0005 (Japan)

    2011-02-18

    Highlights: {yields} VIGG is an ER stress-induced protein in plant. {yields} We examine the characteristics of VIGG-overexpressing Arabidopsis plants. {yields} VIGG-overexpressing plants reveal growth retardation and robustness to ER stress. {yields} VIGG disturbs cation homeostasis in plant. -- Abstract: VIGG is a putative endoplasmic reticulum (ER) resident protein induced by virus infection and ER stress, and is correlated with fruit quality in grapevine. The present study was undertaken to determine the biological function of VIGG in grapevine. Experiments using fluorescent protein-VIGG fusion protein demonstrated that VIGG is localized in ER and the ER targeting sequence is in the N-terminus. The overexpression of VIGG in Arabidopsis plant led to growth retardation. The rosette leaves of VIGG-overexpressing plants were smaller than those of the control plants and rolled at 42 days after seeding. VIGG-overexpressing plants revealed robustness to ER stress as well as the low expression of ER stress marker proteins, such as the luminal binding proteins. These characteristics of VIGG-overexpressing plants were supported by a microarray experiment that demonstrated the disruption of genes related to ER stress response and flowering, as well as cation mobility, in the plants. Finally, cation homeostasis in the plants was disturbed by the overexpression of VIGG. Taken together, these results suggest that VIGG may disturb cation homeostasis in plant, which is correlated with the robustness to ER stress and growth retardation.

  12. Functional characterization of the ER stress induced X-box-binding protein-1 (Xbp-1 in the porcine system

    Directory of Open Access Journals (Sweden)

    Jin Dong-Il

    2011-05-01

    Full Text Available Abstract Background The unfolded protein response (UPR is an evolutionary conserved adaptive reaction for increasing cell survival under endoplasmic reticulum (ER stress conditions. X-box-binding protein-1 (Xbp1 is a key transcription factor of UPR that activates genes involved in protein folding, secretion, and degradation to restore ER function. The UPR induced by ER stress was extensively studied in diseases linked to protein misfolding and aggregations. However, in the porcine system, genes in the UPR pathway were not investigated. In this study, we isolated and characterized the porcine Xbp1 (pXbp1 gene in ER stress using porcine embryonic fibroblast (PEF cells and porcine organs. ER stress was induced by the treatment of tunicamycin and cell viability was investigated by the MTT assay. For cloning and analyzing the expression pattern of pXbp1, RT-PCR analysis and Western blot were used. Knock-down of pXbp1 was performed by the siRNA-mediated gene silencing. Results We found that the pXbp1 mRNA was the subject of the IRE1α-mediated unconventional splicing by ER stress. Knock-down of pXbp1 enhanced ER stress-mediated cell death in PEF cells. In adult organs, pXbp1 mRNA and protein were expressed and the spliced forms were detected. Conclusions It was first found that the UPR mechanisms and the function of pXbp1 in the porcine system. These results indicate that pXbp1 plays an important role during the ER stress response like other animal systems and open a new opportunity for examining the UPR pathway in the porcine model system.

  13. Surviving endoplasmic reticulum stress is coupled to altered chondrocyte differentiation and function.

    Directory of Open Access Journals (Sweden)

    Kwok Yeung Tsang

    2007-03-01

    Full Text Available In protein folding and secretion disorders, activation of endoplasmic reticulum (ER stress signaling (ERSS protects cells, alleviating stress that would otherwise trigger apoptosis. Whether the stress-surviving cells resume normal function is not known. We studied the in vivo impact of ER stress in terminally differentiating hypertrophic chondrocytes (HCs during endochondral bone formation. In transgenic mice expressing mutant collagen X as a consequence of a 13-base pair deletion in Col10a1 (13del, misfolded alpha1(X chains accumulate in HCs and elicit ERSS. Histological and gene expression analyses showed that these chondrocytes survived ER stress, but terminal differentiation is interrupted, and endochondral bone formation is delayed, producing a chondrodysplasia phenotype. This altered differentiation involves cell-cycle re-entry, the re-expression of genes characteristic of a prehypertrophic-like state, and is cell-autonomous. Concomitantly, expression of Col10a1 and 13del mRNAs are reduced, and ER stress is alleviated. ERSS, abnormal chondrocyte differentiation, and altered growth plate architecture also occur in mice expressing mutant collagen II and aggrecan. Alteration of the differentiation program in chondrocytes expressing unfolded or misfolded proteins may be part of an adaptive response that facilitates survival and recovery from the ensuing ER stress. However, the altered differentiation disrupts the highly coordinated events of endochondral ossification culminating in chondrodysplasia.

  14. Metformin differentially activates ER stress signaling pathways without inducing apoptosis

    Directory of Open Access Journals (Sweden)

    Thomas Quentin

    2012-03-01

    Endoplasmic reticulum stress signaling (ERSS plays an important role in the pathogenesis of diabetes and heart disease. The latter is a common comorbidity of diabetes and worsens patient outcome. Results from clinical studies suggest beneficial effects of metformin – a widely used oral drug for the treatment of type 2 diabetes – on the heart of diabetic patients with heart failure. We therefore analyzed the effect of metformin on ERSS in primary rat cardiomyocytes. We found that metformin activates the PERK-ATF4 but not the ATF6 or IRE1-XBP1 branch in ERSS and leads to a strong upregulation of CHOP mRNA and protein. Surprisingly, long-term induction of CHOP by metformin is not accompanied by apoptosis even though CHOP is regarded to be a mediator of ER-stress-induced apoptosis. In conclusion, metformin induces distinct ER stress pathways in cardiomyocytes and our results indicate that CHOP is not necessarily a mediator of apoptosis. Metformin might exert its cardioprotective effect through selective activation of ERSS pathways in the cardiomyocyte.

  15. Metformin differentially activates ER stress signaling pathways without inducing apoptosis.

    Science.gov (United States)

    Quentin, Thomas; Steinmetz, Michael; Poppe, Andrea; Thoms, Sven

    2012-03-01

    Endoplasmic reticulum stress signaling (ERSS) plays an important role in the pathogenesis of diabetes and heart disease. The latter is a common comorbidity of diabetes and worsens patient outcome. Results from clinical studies suggest beneficial effects of metformin - a widely used oral drug for the treatment of type 2 diabetes - on the heart of diabetic patients with heart failure. We therefore analyzed the effect of metformin on ERSS in primary rat cardiomyocytes. We found that metformin activates the PERK-ATF4 but not the ATF6 or IRE1-XBP1 branch in ERSS and leads to a strong upregulation of CHOP mRNA and protein. Surprisingly, long-term induction of CHOP by metformin is not accompanied by apoptosis even though CHOP is regarded to be a mediator of ER-stress-induced apoptosis. In conclusion, metformin induces distinct ER stress pathways in cardiomyocytes and our results indicate that CHOP is not necessarily a mediator of apoptosis. Metformin might exert its cardioprotective effect through selective activation of ERSS pathways in the cardiomyocyte.

  16. Sirt3-Mediated Autophagy Contributes to Resveratrol-Induced Protection against ER Stress in HT22 Cells

    Directory of Open Access Journals (Sweden)

    Wen-Jun Yan

    2018-02-01

    Full Text Available Endoplasmic reticulum (ER stress occurring in stringent conditions is critically involved in neuronal survival and death. Resveratrol is a non-flavonoid polyphenol that has neuroprotective effects against many neurological disorders. Here, we investigated the potential protective effects of resveratrol in an in vitro ER stress model mimicked by tunicamycin (TM treatment in neuronal HT22 cells. We found that TM dose-dependently decreased cell viability and increased apoptosis, which were both significantly attenuated by resveratrol treatment. Resveratrol markedly reduced the expression or activation of ER stress-associated factors, including GRP78, CHOP, and caspase-12. The results of immunocytochemistry and western blot showed that resveratrol promoted autophagy in TM-treated cells, as evidenced by increased LC3II puncta number, bcelin1 expression and LC3II/LC3I ratio. Pretreatment with the autophagy inhibitor chloroquine could reduce the protective effects of resveratrol. In addition, the expression of Sirt3 protein and its downstream enzyme activities were significantly increased in resveratrol-treated HT22 cells. To confirm the involvement of Sirt3-mediated mechanisms, siRNA transfection was used to knockdown Sirt3 expression in vitro. The results showed that downregulation of Sirt3 could partially prevented the autophagy and protection induced by resveratrol after TM treatment. Our study demonstrates a pivotal role of Sirt3-mediated autophagy in mediating resveratrol-induced protection against ER stress in vitro, and suggests the therapeutic values of resveratrol in ER stress-associated neuronal injury conditions.

  17. Endoplasmic reticulum stress pathway-mediated apoptosis in macrophages contributes to the survival of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Yun-Ji Lim

    Full Text Available BACKGROUND: Apoptosis is thought to play a role in host defenses against intracellular pathogens, including Mycobacterium tuberculosis (Mtb, by preventing the release of intracellular components and the spread of mycobacterial infection. This study aims to investigate the role of endoplasmic reticulum (ER stress mediated apoptosis in mycobacteria infected macrophages. METHODOLOGY/PRINCIPAL FINDINGS: Here, we demonstrate that ER stress-induced apoptosis is associated with Mtb H37Rv-induced cell death of Raw264.7 murine macrophages. We have shown that Mtb H37Rv induced apoptosis are involved in activation of caspase-12, which resides on the cytoplasmic district of the ER. Mtb infection increase levels of other ER stress indicators in a time-dependent manner. Phosphorylation of eIF2α was decreased gradually after Mtb H37Rv infection signifying that Mtb H37Rv infection may affect eIF2α phosphorylation in an attempt to survive within macrophages. Interestingly, the survival of mycobacteria in macrophages was enhanced by silencing CHOP expression. In contrast, survival rate of mycobacteria was reduced by phosphorylation of the eIF2α. Futhermore, the levels of ROS, NO or CHOP expression were significantly increased by live Mtb H37Rv compared to heat-killed Mtb H37Rv indicating that live Mtb H37Rv could induce ER stress response. CONCLUSION/SIGNIFICANCE: These findings indicate that eIF2α/CHOP pathway may influence intracellular survival of Mtb H37Rv in macrophages and only live Mtb H37Rv can induce ER stress response. The data support the ER stress pathway plays an important role in the pathogenesis and persistence of mycobacteria.

  18. HSP72 protects cells from ER stress-induced apoptosis via enhancement of IRE1alpha-XBP1 signaling through a physical interaction.

    LENUS (Irish Health Repository)

    Gupta, Sanjeev

    2010-01-01

    Endoplasmic reticulum (ER) stress is a feature of secretory cells and of many diseases including cancer, neurodegeneration, and diabetes. Adaptation to ER stress depends on the activation of a signal transduction pathway known as the unfolded protein response (UPR). Enhanced expression of Hsp72 has been shown to reduce tissue injury in response to stress stimuli and improve cell survival in experimental models of stroke, sepsis, renal failure, and myocardial ischemia. Hsp72 inhibits several features of the intrinsic apoptotic pathway. However, the molecular mechanisms by which Hsp72 expression inhibits ER stress-induced apoptosis are not clearly understood. Here we show that Hsp72 enhances cell survival under ER stress conditions. The UPR signals through the sensor IRE1alpha, which controls the splicing of the mRNA encoding the transcription factor XBP1. We show that Hsp72 enhances XBP1 mRNA splicing and expression of its target genes, associated with attenuated apoptosis under ER stress conditions. Inhibition of XBP1 mRNA splicing either by dominant negative IRE1alpha or by knocking down XBP1 specifically abrogated the inhibition of ER stress-induced apoptosis by Hsp72. Regulation of the UPR was associated with the formation of a stable protein complex between Hsp72 and the cytosolic domain of IRE1alpha. Finally, Hsp72 enhanced the RNase activity of recombinant IRE1alpha in vitro, suggesting a direct regulation. Our data show that binding of Hsp72 to IRE1alpha enhances IRE1alpha\\/XBP1 signaling at the ER and inhibits ER stress-induced apoptosis. These results provide a physical connection between cytosolic chaperones and the ER stress response.

  19. HSP72 protects cells from ER stress-induced apoptosis via enhancement of IRE1alpha-XBP1 signaling through a physical interaction.

    Directory of Open Access Journals (Sweden)

    Sanjeev Gupta

    2010-07-01

    Full Text Available Endoplasmic reticulum (ER stress is a feature of secretory cells and of many diseases including cancer, neurodegeneration, and diabetes. Adaptation to ER stress depends on the activation of a signal transduction pathway known as the unfolded protein response (UPR. Enhanced expression of Hsp72 has been shown to reduce tissue injury in response to stress stimuli and improve cell survival in experimental models of stroke, sepsis, renal failure, and myocardial ischemia. Hsp72 inhibits several features of the intrinsic apoptotic pathway. However, the molecular mechanisms by which Hsp72 expression inhibits ER stress-induced apoptosis are not clearly understood. Here we show that Hsp72 enhances cell survival under ER stress conditions. The UPR signals through the sensor IRE1alpha, which controls the splicing of the mRNA encoding the transcription factor XBP1. We show that Hsp72 enhances XBP1 mRNA splicing and expression of its target genes, associated with attenuated apoptosis under ER stress conditions. Inhibition of XBP1 mRNA splicing either by dominant negative IRE1alpha or by knocking down XBP1 specifically abrogated the inhibition of ER stress-induced apoptosis by Hsp72. Regulation of the UPR was associated with the formation of a stable protein complex between Hsp72 and the cytosolic domain of IRE1alpha. Finally, Hsp72 enhanced the RNase activity of recombinant IRE1alpha in vitro, suggesting a direct regulation. Our data show that binding of Hsp72 to IRE1alpha enhances IRE1alpha/XBP1 signaling at the ER and inhibits ER stress-induced apoptosis. These results provide a physical connection between cytosolic chaperones and the ER stress response.

  20. The Rim101 pathway contributes to ER stress adaptation through sensing the state of plasma membrane.

    Science.gov (United States)

    Obara, Keisuke; Kihara, Akio

    2017-01-01

    Yeast cells sense alterations in the plasma membrane (PM) lipid asymmetry and external alkalization by the sensor protein Rim21, which functions in the Rim101 pathway. Rim101 signaling is initiated at the PM by the recruitment of the Rim101 signaling complex. The PM physically associates with the cortical endoplasmic reticulum (ER) to form ER-PM contact sites, where several signaling events, lipid exchange, and ion transport take place. In the present study, we investigated the spatial relationship between ER-PM contact sites and the sites of Rim101 signaling. Rim101 signaling mostly proceeds outside ER-PM contact sites in the PM and did not require intact ER-PM contact for its activation. Rather, the Rim101 pathway was constitutively activated by ER-PM contact site disruption, which is known to cause ER stress. ER stress induced by tunicamycin treatment activated the Rim101 pathway. Furthermore, the sensitivity of cells to tunicamycin without ER-PM contact was considerably elevated by the deletion of RIM21. These results suggest that the Rim101 pathway is important for the adaptation to ER stress by compensating for alterations in PM lipid asymmetry induced by ER stress. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  1. ER stress in the brain subfornical organ mediates angiotensin-dependent hypertension.

    Science.gov (United States)

    Young, Colin N; Cao, Xian; Guruju, Mallikarjuna R; Pierce, Joseph P; Morgan, Donald A; Wang, Gang; Iadecola, Costantino; Mark, Allyn L; Davisson, Robin L

    2012-11-01

    Although endoplasmic reticulum (ER) stress is a pathologic mechanism in a variety of chronic diseases, it is unclear what role it plays in chronic hypertension (HTN). Dysregulation of brain mechanisms controlling arterial pressure is strongly implicated in HTN, particularly in models involving angiotensin II (Ang II). We tested the hypothesis that ER stress in the brain is causally linked to Ang II-dependent HTN. Chronic systemic infusion of low-dose Ang II in C57BL/6 mice induced slowly developing HTN, which was abolished by co-infusion of the ER stress inhibitor tauroursodeoxycholic acid (TUDCA) into the lateral cerebroventricle. Investigations of the brain regions involved revealed robust increases in ER stress biomarkers and profound ER morphological abnormalities in the circumventricular subfornical organ (SFO), a region outside the blood-brain barrier and replete with Ang II receptors. Ang II-induced HTN could be prevented in this model by selective genetic supplementation of the ER chaperone 78-kDa glucose-regulated protein (GRP78) in the SFO. These data demonstrate that Ang II-dependent HTN is mediated by ER stress in the brain, particularly the SFO. To our knowledge, this is the first report that ER stress, notably brain ER stress, plays a key role in chronic HTN. Taken together, these findings may have broad implications for the pathophysiology of this disease.

  2. Targeting the hallmarks of cancer with therapy-induced endoplasmic reticulum (ER) stress

    Science.gov (United States)

    Garg, Abhishek D; Maes, Hannelore; van Vliet, Alexander R; Agostinis, Patrizia

    2015-01-01

    The endoplasmic reticulum (ER) is at the center of a number of vital cellular processes such as cell growth, death, and differentiation, crosstalk with immune or stromal cells, and maintenance of proteostasis or homeostasis, and ER functions have implications for various pathologies including cancer. Recently, a number of major hallmarks of cancer have been delineated that are expected to facilitate the development of anticancer therapies. However, therapeutic induction of ER stress as a strategy to broadly target multiple hallmarks of cancer has been seldom discussed despite the fact that several primary or secondary ER stress-inducing therapies have been found to exhibit positive clinical activity in cancer patients. In the present review we provide a brief historical overview of the major discoveries and milestones in the field of ER stress biology with important implications for anticancer therapy. Furthermore, we comprehensively discuss possible strategies enabling the targeting of multiple hallmarks of cancer with therapy-induced ER stress. PMID:27308392

  3. Inhibition of autophagic flux by ROS promotes apoptosis during DTT-induced ER/oxidative stress in HeLa cells.

    Science.gov (United States)

    Xiang, Xi-Yan; Yang, Xiao-Chun; Su, Jin; Kang, Jing-Song; Wu, Yao; Xue, Ya-Nan; Dong, Yu-Tong; Sun, Lian-Kun

    2016-06-01

    As targets for cancer therapy, endoplasmic reticulum (ER) stress and autophagy are closely linked. However, the signaling pathways responsible for induction of autophagy in response to ER stress and its cellular consequences appear to vary with cell type and stimulus. In the present study, we showed that dithiothreitol (DTT) induced ER stress in HeLa cells in a time- and dose-dependent fashion. With increased ER stress, reactive oxygen species (ROS) production increased and autophagy flux, assessed by intracellular accumulation of LC3B-II and p62, was inhibited. N-acetyl-L-cysteine (NAC), a classic antioxidant, exacerbated cell death induced by 3.2 mM of DTT, but attenuated that induced by 6.4 mM DTT. Low cytotoxic doses of DTT transiently activated c-JNU N-terminal kinase (JNK) and p38, whereas high dose of DTT persistently activated JNK and p38 and simultaneously reduced extracellular signal-regulated kinase (ERK) activity. Combined treatment with DTT and U0126, an inhibitor of ERK upstream activators mitogen-activated protein kinase (MAPK) kinase 1 and 2 (MEK1/2), blocked autophagy flux in HeLa cells. This effect was similar to that caused by a combination of DTT and chloroquine (CQ). These data suggested that insufficient autophagy was accompanied by increased ROS production during DTT-induced ER stress. ROS appeared to regulate MAPK signaling, switching from a pro-survival to a pro-apoptotic signal as ER stress increased. ERK inhibition by ROS during severe ER stress blocked autophagic flux. Impaired autophagic flux, in turn, aggravated ER stress, ultimately leading to cell death. Taken together, our data provide the first reported evidence that ROS may control cell fate through regulating the MAPK pathways and autophagic flux during DTT-induced ER/oxidative stress.

  4. Coronavirus-induced ER stress response and its involvement in regulation of coronavirus-host interactions.

    Science.gov (United States)

    Fung, To Sing; Huang, Mei; Liu, Ding Xiang

    2014-12-19

    Coronavirus replication is structurally and functionally associated with the endoplasmic reticulum (ER), a major site of protein synthesis, folding, modification and sorting in the eukaryotic cells. Disturbance of ER homeostasis may occur under various physiological or pathological conditions. In response to the ER stress, signaling pathways of the unfolded protein response (UPR) are activated. UPR is mediated by three ER transmembrane sensors, namely the PKR-like ER protein kinase (PERK), the inositol-requiring protein 1 (IRE1) and the activating transcriptional factor 6 (ATF6). UPR facilitates adaptation to ER stress by reversible translation attenuation, enhancement of ER protein folding capacity and activation of ER-associated degradation (ERAD). In cells under prolonged and irremediable ER stress, UPR can also trigger apoptotic cell death. Accumulating evidence has shown that coronavirus infection causes ER stress and induces UPR in the infected cells. UPR is closely associated with a number of major signaling pathways, including autophagy, apoptosis, the mitogen-activated protein (MAP) kinase pathways, innate immunity and pro-inflammatory response. Therefore, studies on the UPR are pivotal in elucidating the complicated issue of coronavirus-host interaction. In this paper, we present the up-to-date knowledge on coronavirus-induced UPR and discuss its potential involvement in regulation of innate immunity and apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Emerging roles of ER stress and unfolded protein response pathways in skeletal muscle health and disease.

    Science.gov (United States)

    Bohnert, Kyle R; McMillan, Joseph D; Kumar, Ashok

    2018-01-01

    Skeletal muscle is the most abundant tissue in the human body and can adapt its mass as a consequence of physical activity, metabolism, growth factors, and disease conditions. Skeletal muscle contains an extensive network of endoplasmic reticulum (ER), called sarcoplasmic reticulum, which plays an important role in the regulation of proteostasis and calcium homeostasis. In many cell types, environmental and genetic factors that disrupt ER function cause an accumulation of misfolded and unfolded proteins in the ER lumen that ultimately leads to ER stress. To alleviate the stress and restore homeostasis, the ER activates a signaling network called the unfolded protein response (UPR). The UPR has three arms, which regulate protein synthesis and expression of many ER chaperone and regulatory proteins. However, the role of individual UPR pathways in skeletal muscle has just begun to be investigated. Recent studies suggest that UPR pathways play pivotal roles in muscle stem cell homeostasis, myogenic differentiation, and regeneration of injured skeletal muscle. Moreover, markers of ER stress and the UPR are activated in skeletal muscle in diverse conditions such as exercise, denervation, starvation, high fat diet, cancer cachexia, and aging. Accumulating evidence also suggests that ER stress may have important roles in the pathogenesis of inflammatory myopathies and genetic muscle disorders. The purpose of this review article is to discuss the role and potential mechanisms by which ER stress and the individual arms of the UPR regulate skeletal muscle formation, plasticity, and function in various physiological and pathophysiological conditions. © 2017 Wiley Periodicals, Inc.

  6. Transient ER retention as stress response: conformational repair of heat-damaged proteins to secretion-competent structures.

    Science.gov (United States)

    Saris, N; Makarow, M

    1998-06-01

    Mechanisms to acquire tolerance against heat, an important environmental stress condition, have evolved in all organisms, but are largely unknown. When Saccharomyces cerevisiae cells are pre-conditioned at 37 degrees C, they survive an otherwise lethal exposure to 48-50 degrees C, and form colonies at 24 degrees C. We show here that incubation of yeast cells at 48-50 degrees C, after pre-conditioning at 37 degrees C, resulted in inactivation of exocytosis, and in conformational damage and loss of transport competence of proteins residing in the endoplasmic reticulum (ER). Soon after return of the cells to 24 degrees C, membrane traffic was resumed, but cell wall invertase, vacuolar carboxypeptidase Y and a secretory beta-lactamase fusion protein remained in the ER for different times. Thereafter their transport competence was resumed very slowly with widely varying kinetics. While the proteins were undergoing conformational repair in the ER, their native counterparts, synthesized after shift of the cells to 24 degrees C, folded normally, by-passed the heat-affected copies and exited rapidly the ER. The Hsp70 homolog Lhs1p was required for acquisition of secretion competence of heat-damaged proteins. ER retention and refolding of heat-denatured glycoproteins appear to be part of the cellular stress response.

  7. The role of ER stress response on ionizing radiation-induced apoptosis in intestinal epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Sang; Kim, Kwang Seok; Woo, Sang Keun; Lee, Yong Jin; Jeong, Jae Hoon; Lee, Yoon Jin; Kang, Seong Man; Lim, Young Bin [Laboratory of Radiation Effect, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2014-04-15

    Apoptosis in the intestinal epithelium is the primary pathologic factor that initiates radiation-induced intestinal injury. However, mechanism involved in ionizing radiation (IR)-induced apoptosis in the intestinal epithelium is not clearly understood. The endoplasmic reticulum (ER) stress is triggered by perturbation of the ER functions, leading to the activation of the unfolded protein response (UPR), an adaptive signaling cascade aimed at restoring ER homeostasis by facilitating the degradation of misfolded proteins and expanding the protein folding capacity of the cell. Recently, IR has also been shown to induce ER stress, thereby activating the UPR signaling pathway in intestinal epithelial cells. In this study, we report the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhance IR-induced caspase3 activation. Knockdown of xbp1 or atf6 with siRNA leads to inhibition of IR-induced caspase3 activation. Taken together, our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Our findings could contribute to the development of new strategies based on modulating ER stress responses to prevent IR-induced intestinal injury.

  8. Fine-Tuning ER Stress Signal Transducers to Treat Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Medinas, Danilo B; González, Jose V; Falcon, Paulina; Hetz, Claudio

    2017-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motoneurons and paralysis. The mechanisms underlying neuronal degeneration in ALS are starting to be elucidated, highlighting disturbances in motoneuron proteostasis. Endoplasmic reticulum (ER) stress has emerged as an early pathogenic event underlying motoneuron vulnerability and denervation in ALS. Maintenance of ER proteostasis is controlled by a dynamic signaling network known as the unfolded protein response (UPR). Inositol-requiring enzyme 1 (IRE1) is an ER-located kinase and endoribonuclease that operates as a major ER stress transducer, mediating the establishment of adaptive and pro-apoptotic programs. Here we discuss current evidence supporting the role of ER stress in motoneuron demise in ALS and build the rational to target IRE1 to ameliorate neurodegeneration.

  9. Fine-Tuning ER Stress Signal Transducers to Treat Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Danilo B. Medinas

    2017-07-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is a fatal neurodegenerative disease characterized by the progressive loss of motoneurons and paralysis. The mechanisms underlying neuronal degeneration in ALS are starting to be elucidated, highlighting disturbances in motoneuron proteostasis. Endoplasmic reticulum (ER stress has emerged as an early pathogenic event underlying motoneuron vulnerability and denervation in ALS. Maintenance of ER proteostasis is controlled by a dynamic signaling network known as the unfolded protein response (UPR. Inositol-requiring enzyme 1 (IRE1 is an ER-located kinase and endoribonuclease that operates as a major ER stress transducer, mediating the establishment of adaptive and pro-apoptotic programs. Here we discuss current evidence supporting the role of ER stress in motoneuron demise in ALS and build the rational to target IRE1 to ameliorate neurodegeneration.

  10. Mitofusin 2 in POMC neurons connects ER stress with leptin resistance and energy imbalance

    DEFF Research Database (Denmark)

    Schneeberger, Marc; Dietrich, Marcelo O; Sebastián, David

    2013-01-01

    Mitofusin 2 (MFN2) plays critical roles in both mitochondrial fusion and the establishment of mitochondria-endoplasmic reticulum (ER) interactions. Hypothalamic ER stress has emerged as a causative factor for the development of leptin resistance, but the underlying mechanisms are largely unknown....

  11. Endoplasmic reticulum (ER) stress and cAMP/PKA pathway mediated Zn-induced hepatic lipolysis.

    Science.gov (United States)

    Song, Yu-Feng; Hogstrand, Christer; Wei, Chuan-Chuan; Wu, Kun; Pan, Ya-Xiong; Luo, Zhi

    2017-09-01

    The present study was performed to determine the effect of Zn exposure influencing endoplasmic reticulum (ER) stress, explore the underlying molecular mechanism of Zn-induced hepatic lipolysis in a fish species of significance for aquaculture, yellow catfish Pelteobagrus fulvidraco. We found that waterborne Zn exposure evoked ER stress and unfolded protein response (UPR), and activated cAMP/PKA pathway, and up-regulated hepatic lipolysis. The increase in ER stress and lipolysis were associated with activation of cAMP/PKA signaling pathway. Zn also induced an increase in intracellular Ca2+ level, which could be partially prevented by dantrolene (RyR receptor inhibitor) and 2-APB (IP3 receptor inhibitor), demonstrating that the disturbed Ca2+ homeostasis in ER contributed to ER stress and dysregulation of lipolysis. Inhibition of ER stress by PBA attenuated UPR, inhibited the activation of cAMP/PKA pathway and resulted in down-regulation of lipolysis. Inhibition of protein kinase RNA-activated-like ER kinase (PERK) by GSK2656157 and inositol-requiring enzyme (IRE) by STF-083010 differentially influenced Zn-induced changes of lipid metabolism, indicating that PERK and IRE pathways played different regulatory roles in Zn-induced lipolysis. Inhibition of PKA by H89 blocked the Zn-induced activation of cAMP/PKA pathway with a concomitant inhibition of ER stress-mediated lipolysis. Taken together, our findings highlight the importance of the ER stress-cAMP/PKA axis in Zn-induced lipolysis, which provides new insights into Zn toxicology in fish and probably in other vertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 4-PBA improves lithium-induced nephrogenic diabetes insipidus by attenuating ER stress.

    Science.gov (United States)

    Zheng, Peili; Lin, Yu; Wang, Feifei; Luo, Renfei; Zhang, Tiezheng; Hu, Shan; Feng, Pinning; Liang, Xinling; Li, Chunling; Wang, Weidong

    2016-10-01

    Endoplasmic reticulum (ER) stress has been implicated in some types of glomerular and tubular disorders. The objectives of this study were to elucidate the role of ER stress in lithium-induced nephrogenic diabetes insipidus (NDI) and to investigate whether attenuation of ER stress by 4-phenylbutyric acid (4-PBA) improves urinary concentrating defect in lithium-treated rats. Wistar rats received lithium (40 mmol/kg food), 4-PBA (320 mg/kg body wt by gavage every day), or no treatment (control) for 2 wk, and they were dehydrated for 24 h before euthanasia. Lithium treatment resulted in increased urine output and decreased urinary osmolality, which was significantly improved by 4-PBA. 4-PBA also prevented reduced protein expression of aquaporin-2 (AQP2), pS256-AQP2, and pS261-AQP2 in the inner medulla of kidneys from lithium-treated rats after 24-h dehydration. Lithium treatment resulted in increased expression of ER stress markers in the inner medulla, which was associated with dilated cisternae and expansion of ER in the inner medullary collecting duct (IMCD) principal cells. Confocal immunofluorescence studies showed colocalization of a molecular chaperone, binding IgG protein (BiP), with AQP2 in principal cells. Immunohistochemistry demonstrated increased intracellular expression of BiP and decreased AQP2 expression in IMCD principal cells of kidneys from lithium-treated rats. 4-PBA attenuated expression of ER stress markers and recovered ER morphology. In IMCD suspensions isolated from lithium-treated rats, 4-PBA incubation was also associated with increased AQP2 expression and ameliorated ER stress. In conclusion, in experimental lithium-induced NDI, 4-PBA improved the urinary concentrating defect and increased AQP2 expression, likely via attenuating ER stress in IMCD principal cells. Copyright © 2016 the American Physiological Society.

  13. Expression of human Gaucher disease gene GBA generates neurodevelopmental defects and ER stress in Drosophila eye.

    Directory of Open Access Journals (Sweden)

    Takahiro Suzuki

    Full Text Available Gaucher disease (GD is the most common of the lysosomal storage disorders and is caused by defects in the GBA gene encoding glucocerebrosidase (GlcCerase. The accumulation of its substrate, glucocylceramide (GlcCer is considered the main cause of GD. We found here that the expression of human mutated GlcCerase gene (hGBA that is associated with neuronopathy in GD patients causes neurodevelopmental defects in Drosophila eyes. The data indicate that endoplasmic reticulum (ER stress was elevated in Drosophila eye carrying mutated hGBAs by using of the ER stress markers dXBP1 and dBiP. We also found that Ambroxol, a potential pharmacological chaperone for mutated hGBAs, can alleviate the neuronopathic phenotype through reducing ER stress. We demonstrate a novel mechanism of neurodevelopmental defects mediated by ER stress through expression of mutants of human GBA gene in the eye of Drosophila.

  14. ENC1 Modulates the Aggregation and Neurotoxicity of Mutant Huntingtin Through p62 Under ER Stress.

    Science.gov (United States)

    Lee, Huikyong; Ahn, Hye-Hyun; Lee, WonJae; Oh, Yumin; Choi, Hyunwoo; Shim, Sang Mi; Shin, Jaekyoon; Jung, Yong-Keun

    2016-12-01

    Huntington's disease (HD) is a devastating neurodegenerative disorder, which is caused by the expression and aggregation of polyQ-expanded mutant huntingtin protein (mtHTT). While toxic mtHTT aggregates are primarily eliminated through autophagy, autophagy dysfunction is often observed in HD pathogenesis. Here, we show that ectodermal-neural cortex 1 (ENC1), a novel binding partner of sequestosome 1 (p62), negatively regulates autophagy under endoplasmic reticulum (ER) stress. We found that ER stress significantly increases the expression of ENC1 via inositol-requiring enzyme 1 (IRE1)-TNF receptor-associated factor 2 (TRAF2)-c-Jun N-terminal kinase (JNK) pathway. Ectopic expression of ENC1 alone induces the accumulation of detergent-resistant mtHTT aggregates and downregulation of ENC1 alleviates ER stress-induced mtHTT aggregation. Simultaneously, ER stress-induced impairment of autophagy flux is ameliorated by downregulation of ENC1. From immunoprecipitation and immunocytochemical assays, we found that ENC1 binds to p62 through its BTB and C-terminal Kelch (BACK) domain and this interaction is enhanced under ER stress. In particular, ENC1 preferentially interacts with the phosphorylated p62 at Ser403 during ER stress. Interestingly, ENC1 colocalizes with mtHTT aggregates and its C-terminal Kelch domain is required for interfering with the access of p62 to ubiquitinated mtHTT aggregates, thus inhibiting cargo recognition of p62. Accordingly, knockdown of ENC1 expression enhances colocalization of p62 with mtHTT aggregates. Consequently, ENC1 knockdown relieves death of neuronal cells expressing mtHTT under ER stress. These results suggest that ENC1 interacts with the phosphorylated p62 to impair autophagic degradation of mtHTT aggregates and affects cargo recognition failure under ER stress, leading to the accumulation and neurotoxicity of mtHTT aggregates.

  15. ER stress affects processing of MHC class I-associated peptides

    Directory of Open Access Journals (Sweden)

    Meloche Sylvain

    2009-02-01

    Full Text Available Abstract Background Viral infection and neoplastic transformation trigger endoplasmic reticulum (ER stress. Thus, a large proportion of the cells that must be recognized by the immune system are stressed cells. Cells respond to ER stress by launching the unfolded protein response (UPR. The UPR regulates the two key processes that control major histocompatibility complex class I (MHC I-peptide presentation: protein synthesis and degradation. We therefore asked whether and how the UPR impinges on MHC I-peptide presentation. Results We evaluated the impact of the UPR on global MHC I expression and on presentation of the H2Kb-associated SIINFEKL peptide. EL4 cells stably transfected with vectors coding hen egg lysozyme (HEL-SIINFEKL protein variants were stressed with palmitate or exposed to glucose deprivation. UPR decreased surface expression of MHC I but did not affect MHC I mRNA level nor the total amount of intracellular MHC I proteins. Impaired MHC I-peptide presentation was due mainly to reduced supply of peptides owing to an inhibition of overall protein synthesis. Consequently, generation of H2Kb-SIINFEKL complexes was curtailed during ER stress, illustrating how generation of MHC I peptide ligands is tightly coupled to ongoing protein synthesis. Notably, the UPR-induced decline of MHC I-peptide presentation was more severe when the protein source of peptides was localized in the cytosol than in the ER. This difference was not due to changes in the translation rates of the precursor proteins but to increased stability of the cytosolic protein during ER stress. Conclusion Our results demonstrate that ER stress impairs MHC I-peptide presentation, and that it differentially regulates expression of ER- vs. cytosol-derived peptides. Furthermore, this work illustrates how ER stress, a typical feature of infected and malignant cells, can impinge on cues for adaptive immune recognition.

  16. ER stress affects processing of MHC class I-associated peptides.

    Science.gov (United States)

    Granados, Diana P; Tanguay, Pierre-Luc; Hardy, Marie-Pierre; Caron, Etienne; de Verteuil, Danielle; Meloche, Sylvain; Perreault, Claude

    2009-02-16

    Viral infection and neoplastic transformation trigger endoplasmic reticulum (ER) stress. Thus, a large proportion of the cells that must be recognized by the immune system are stressed cells. Cells respond to ER stress by launching the unfolded protein response (UPR). The UPR regulates the two key processes that control major histocompatibility complex class I (MHC I)-peptide presentation: protein synthesis and degradation. We therefore asked whether and how the UPR impinges on MHC I-peptide presentation. We evaluated the impact of the UPR on global MHC I expression and on presentation of the H2Kb-associated SIINFEKL peptide. EL4 cells stably transfected with vectors coding hen egg lysozyme (HEL)-SIINFEKL protein variants were stressed with palmitate or exposed to glucose deprivation. UPR decreased surface expression of MHC I but did not affect MHC I mRNA level nor the total amount of intracellular MHC I proteins. Impaired MHC I-peptide presentation was due mainly to reduced supply of peptides owing to an inhibition of overall protein synthesis. Consequently, generation of H2Kb-SIINFEKL complexes was curtailed during ER stress, illustrating how generation of MHC I peptide ligands is tightly coupled to ongoing protein synthesis. Notably, the UPR-induced decline of MHC I-peptide presentation was more severe when the protein source of peptides was localized in the cytosol than in the ER. This difference was not due to changes in the translation rates of the precursor proteins but to increased stability of the cytosolic protein during ER stress. Our results demonstrate that ER stress impairs MHC I-peptide presentation, and that it differentially regulates expression of ER- vs. cytosol-derived peptides. Furthermore, this work illustrates how ER stress, a typical feature of infected and malignant cells, can impinge on cues for adaptive immune recognition.

  17. Protective effect of carbenoxolone on ER stress-induced cell death in hypothalamic neurons.

    Science.gov (United States)

    Kim, Jongwan; Jung, Eun Jung; Moon, Seong-Su; Seo, Minchul

    2015-12-25

    Hypothalamic endoplasmic reticulum (ER) stress is known to be increased in obesity. Induction of ER stress on hypothalamic neurons has been reported to cause hypothalamic neuronal apoptosis and malfunction of energy balance, leading to obesity. Carbenoxolone is an 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitor that converts inactive glucocorticoid into an active form. In addition to its metabolic effect via enzyme inhibitory action, carbenoxolone has shown anti-apoptotic activity in several studies. In this study, the direct effects of carbenoxolone on ER stress and cell death in hypothalamic neurons were investigated. Carbenoxolone attenuated tunicamycin induced ER stress-mediated molecules such as spliced XBP1, ATF4, ATF6, CHOP, and ROS generation. In vivo study also revealed that carbenoxolone decreased tunicamycin-induced ER stress in the hypothalamus. In conclusion, the results of this study show that carbenoxolone has protective effects against tunicamycin induced-ER stress and apoptosis in hypothalamic neurons, suggesting its direct protective effects against obesity. Further study is warranted to clarify the effects of carbenoxolone on hypothalamic regulation of energy balance in obesity. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Differential targeting of androgen and glucocorticoid receptors induces ER stress and apoptosis in prostate cancer cells

    Science.gov (United States)

    Bhalla, Pankaj; Yang, Ximing; Ugolkov, Andrey; Iwadate, Kenichi; Karseladze, Apollon; Budunova, Irina

    2012-01-01

    Androgen (AR) and glucocorticoid (GR) receptor signaling play opposing roles in prostate tumorigenesis: in prostate, AR acts as an oncogene, and GR is a tumor suppressor. Recently, we found that non-steroidal phyto-chemical compound A (CpdA) is AR/GR modulator acting as anti-inflammatory anti-androgen. CpdA inhibits AR and prevents GR transactivation while enhancing GR transrepression. GR and AR are controlled by proteasomal degradation. We found that prolonged exposure of LNCaP, LNCaP-GR, DU145 and PC3 prostate carcinoma (PCa) cells to proteasome inhibitor Bortezomib (BZ) caused AR degradation and GR accumulation. BZ enhanced CpdA ability to inhibit AR and to augment GR transrepression. We also found that CpdA+BZ differentially regulated GR/AR to cooperatively suppress PCa cell growth and survival and to induce endoplasmic reticulum stress (ERS). Importantly, CpdA+BZ differentially regulated GR-responsive genes. CpdA+BZ blocked activation of glucocorticoid-responsive pro-survival genes, including SGK1, but activated BZ-induced ERS-related genes BIP/HSPA5 and CHOP/GADD153. Using ChIP, we showed that SGK1, BIP/HSPA5 and CHOP regulation was due to effects of CpdA and CpdA+BZ on GR loading on their promoters. We also found that AR and GR are abundant in advanced PCa from patients treated by androgen ablation and/or chemotherapy: 56% of carcinomas from treated patients expressed both receptors, and the other 27% expressed either GR or AR. Overall, our data validate the concept of dual AR/GR targeting in prostate cancer (PC) and suggest that BZ combination with dual-target steroid receptor modulator CpdA has high potential for PC therapy. PMID:22223138

  19. The ER Stress Sensor PERK Coordinates ER-Plasma Membrane Contact Site Formation through Interaction with Filamin-A and F-Actin Remodeling.

    Science.gov (United States)

    van Vliet, Alexander R; Giordano, Francesca; Gerlo, Sarah; Segura, Inmaculada; Van Eygen, Sofie; Molenberghs, Geert; Rocha, Susana; Houcine, Audrey; Derua, Rita; Verfaillie, Tom; Vangindertael, Jeroen; De Keersmaecker, Herlinde; Waelkens, Etienne; Tavernier, Jan; Hofkens, Johan; Annaert, Wim; Carmeliet, Peter; Samali, Afshin; Mizuno, Hideaki; Agostinis, Patrizia

    2017-03-02

    Loss of ER Ca(2+) homeostasis triggers endoplasmic reticulum (ER) stress and drives ER-PM contact sites formation in order to refill ER-luminal Ca(2+). Recent studies suggest that the ER stress sensor and mediator of the unfolded protein response (UPR) PERK regulates intracellular Ca(2+) fluxes, but the mechanisms remain elusive. Here, using proximity-dependent biotin identification (BioID), we identified the actin-binding protein Filamin A (FLNA) as a key PERK interactor. Cells lacking PERK accumulate F-actin at the cell edges and display reduced ER-PM contacts. Following ER-Ca(2+) store depletion, the PERK-FLNA interaction drives the expansion of ER-PM juxtapositions by regulating F-actin-assisted relocation of the ER-associated tethering proteins Stromal Interaction Molecule 1 (STIM1) and Extended Synaptotagmin-1 (E-Syt1) to the PM. Cytosolic Ca(2+) elevation elicits rapid and UPR-independent PERK dimerization, which enforces PERK-FLNA-mediated ER-PM juxtapositions. Collectively, our data unravel an unprecedented role of PERK in the regulation of ER-PM appositions through the modulation of the actin cytoskeleton. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Evidence that endoplasmic reticulum (ER) stress and caspase-4 activation occur in human neutrophils

    Energy Technology Data Exchange (ETDEWEB)

    Binet, Francois; Chiasson, Sonia [Laboratoire de recherche en inflammation et physiologie des granulocytes, Universite du Quebec, INRS-Institut Armand-Frappier, Laval, QC (Canada); Girard, Denis, E-mail: denis.girard@iaf.inrs.ca [Laboratoire de recherche en inflammation et physiologie des granulocytes, Universite du Quebec, INRS-Institut Armand-Frappier, Laval, QC (Canada)

    2010-01-01

    Apoptosis can result from activation of three major pathways: the extrinsic, the intrinsic, and the most recently identified endoplasmic reticulum (ER) stress-mediated pathway. While the two former pathways are known to be operational in human polymorphonuclear neutrophils (PMNs), the existence of the ER stress-mediated pathway, generally involving caspase-4, has never been reported in these cells. Recently, we have documented that arsenic trioxide (ATO) induced apoptosis in human PMNs by a mechanism that needs to be further investigated. In this study, using immunofluorescence and electron microscopy, we present evidence of ER alterations in PMNs activated by the ER stress inducer arsenic trioxide (ATO). Several key players of the unfolded protein response, including GRP78, GADD153, ATF6, XBP1 and eIF2{alpha} are expressed and activated in PMNs treated with ATO or other ER stress inducers. Although caspase-4 is expressed and activated in neutrophils, treatment with a caspase-4 inhibitor did not attenuate the pro-apoptotic effect of ATO at a concentration that reverses caspase-4 processing and activation. Our results demonstrate for the first time that the ER stress-mediated apoptotic pathway operates in human neutrophils.

  1. ER Stress and Unfolded Protein Response in Amyotrophic Lateral Sclerosis – A Controversial Role of Protein Disulphide Isomerase

    Directory of Open Access Journals (Sweden)

    Merja eJaronen

    2014-12-01

    Full Text Available Accumulation of proteins in aberrant conformation occurs in many neurodegenerative diseases. Furthermore, dysfunctions in protein handling in endoplasmic reticulum (ER and the following ER stress have been implicated in a vast number of diseases, such as amyotrophic lateral sclerosis (ALS. During excessive ER stress unfolded protein response (UPR is activated to return ER to its normal physiological balance. The exact mechanisms of protein misfolding, accumulation and the following ER stress could lead to neurodegeneration and the question whether UPR is a beneficial compensatory mechanism slowing down the neurodegenerative processes are of interest. Protein disulphide isomerase (PDI is a disulfide bond-modulating ER chaperone, which can also facilitate the ER-associated degradation (ERAD of misfolded proteins. In this review we discuss the recent findings of ER stress, UPR and especially the role of PDI in ALS.

  2. Hepatitis C Virus Infection Induces Autophagy as a Prosurvival Mechanism to Alleviate Hepatic ER-Stress Response

    Directory of Open Access Journals (Sweden)

    Srikanta Dash

    2016-05-01

    Full Text Available Hepatitis C virus (HCV infection frequently leads to chronic liver disease, liver cirrhosis and hepatocellular carcinoma (HCC. The molecular mechanisms by which HCV infection leads to chronic liver disease and HCC are not well understood. The infection cycle of HCV is initiated by the attachment and entry of virus particles into a hepatocyte. Replication of the HCV genome inside hepatocytes leads to accumulation of large amounts of viral proteins and RNA replication intermediates in the endoplasmic reticulum (ER, resulting in production of thousands of new virus particles. HCV-infected hepatocytes mount a substantial stress response. How the infected hepatocyte integrates the viral-induced stress response with chronic infection is unknown. The unfolded protein response (UPR, an ER-associated cellular transcriptional response, is activated in HCV infected hepatocytes. Over the past several years, research performed by a number of laboratories, including ours, has shown that HCV induced UPR robustly activates autophagy to sustain viral replication in the infected hepatocyte. Induction of the cellular autophagy response is required to improve survival of infected cells by inhibition of cellular apoptosis. The autophagy response also inhibits the cellular innate antiviral program that usually inhibits HCV replication. In this review, we discuss the physiological implications of the HCV-induced chronic ER-stress response in the liver disease progression.

  3. Lycopene Protects against Hypoxia/Reoxygenation Injury by Alleviating ER Stress Induced Apoptosis in Neonatal Mouse Cardiomyocytes

    Science.gov (United States)

    Xu, Jiqian; Hu, Houxiang; Chen, Bin; Yue, Rongchuan; Zhou, Zhou; Liu, Yin; Zhang, Shuang; Xu, Lei; Wang, Huan; Yu, Zhengping

    2015-01-01

    Endoplasmic reticulum (ER) stress induced apoptosis plays a pivotal role in myocardial ischemia/reperfusion (I/R)-injury. Inhibiting ER stress is a major therapeutic target/strategy in treating cardiovascular diseases. Our previous studies revealed that lycopene exhibits great pharmacological potential in protecting against the I/R-injury in vitro and vivo, but whether attenuation of ER stress (and) or ER stress-induced apoptosis contributes to the effects remains unclear. In the present study, using neonatal mouse cardiomyocytes to establish an in vitro model of hypoxia/reoxygenation (H/R) to mimic myocardium I/R in vivo, we aimed to explore the hypothesis that lycopene could alleviate the ER stress and ER stress-induced apoptosis in H/R-injury. We observed that lycopene alleviated the H/R injury as revealed by improving cell viability and reducing apoptosis, suppressed reactive oxygen species (ROS) generation and improved the phosphorylated AMPK expression, attenuated ER stress as evidenced by decreasing the expression of GRP78, ATF6 mRNA, sXbp-1 mRNA, eIF2α mRNA and eIF2α phosphorylation, alleviated ER stress-induced apoptosis as manifested by reducing CHOP/GADD153 expression, the ratio of Bax/Bcl-2, caspase-12 and caspase-3 activity in H/R-treated cardiomyocytes. Thapsigargin (TG) is a potent ER stress inducer and used to elicit ER stress of cardiomyocytes. Our results showed that lycopene was able to prevent TG-induced ER stress as reflected by attenuating the protein expression of GRP78 and CHOP/GADD153 compared to TG group, significantly improve TG-caused a loss of cell viability and decrease apoptosis in TG-treated cardiomyocytes. These results suggest that the protective effects of lycopene on H/R-injury are, at least in part, through alleviating ER stress and ER stress-induced apoptosis in neonatal mouse cardiomyocytes. PMID:26291709

  4. Inhibition of ER stress and unfolding protein response pathways causes skeletal muscle wasting during cancer cachexia

    Science.gov (United States)

    Bohnert, Kyle R.; Gallot, Yann S.; Sato, Shuichi; Xiong, Guangyan; Hindi, Sajedah M.; Kumar, Ashok

    2016-01-01

    Cachexia is a devastating syndrome that causes morbidity and mortality in a large number of patients with cancer. However, the mechanisms of cancer cachexia remain poorly understood. Accumulation of misfolded proteins in the endoplasmic reticulum (ER) causes stress. The ER responds to this stress through activating certain pathways commonly known as the unfolding protein response (UPR). The main function of UPR is to restore homeostasis, but excessive or prolonged activation of UPR can lead to pathologic conditions. In this study, we examined the role of ER stress and UPR in regulation of skeletal muscle mass in naïve conditions and during cancer cachexia. Our results demonstrate that multiple markers of ER stress are highly activated in skeletal muscle of Lewis lung carcinoma (LLC) and ApcMin/+ mouse models of cancer cachexia. Treatment of mice with 4-phenylbutyrate (4-PBA), a chemical chaperon and a potent inhibitor of ER stress, significantly reduced skeletal muscle strength and mass in both control and LLC-bearing mice. Blocking the UPR also increased the proportion of fast-type fibers in soleus muscle of both control and LLC-bearing mice. Inhibition of UPR reduced the activity of Akt/mTOR pathway and increased the expression of the components of the ubiquitin–proteasome system and autophagy in LLC-bearing mice. Moreover, we found that the inhibition of UPR causes severe atrophy in cultured myotubes. Our study provides initial evidence that ER stress and UPR pathways are essential for maintaining skeletal muscle mass and strength and for protection against cancer cachexia.—Bohnert, K. R., Gallot, Y. S., Sato, S., Xiong, G., Hindi, S. M., Kumar, A. Inhibition of ER stress and unfolding protein response pathways causes skeletal muscle wasting during cancer cachexia. PMID:27206451

  5. Salidroside Protects Against 6-Hydroxydopamine-Induced Cytotoxicity by Attenuating ER Stress.

    Science.gov (United States)

    Tao, Kai; Wang, Bao; Feng, Dayun; Zhang, Wei; Lu, Fangfang; Lai, Juan; Huang, Lu; Nie, Tiejian; Yang, Qian

    2016-02-01

    Parkinson's disease (PD) is a neurodegenerative disease characterized by a persistent decline of dopaminergic (DA) neurons in the substantia nigra pars compacta. Despite its frequency, effective therapeutic strategies that halt the neurodegenerative processes are lacking, reinforcing the need to better understand the molecular drivers of this disease. Importantly, increasing evidence suggests that the endoplasmic reticulum (ER) stress-induced unfolded protein response is likely involved in DA neuronal death. Salidroside, a major compound isolated from Rhodiola rosea L., possesses potent anti-oxidative stress properties and protects against DA neuronal death. However, the underlying mechanisms are not well understood. In the present study, we demonstrate that salidroside prevents 6-hydroxydopamine (6-OHDA)-induced cytotoxicity by attenuating ER stress. Furthermore, treatment of a DA neuronal cell line (SN4741) and primary cortical neurons with salidroside significantly reduced neurotoxin-induced increases in cytoplasmic reactive oxygen species and calcium, both of which cause ER stress, and cleaved caspase-12, which is responsible for ER stress-induced cell death. Together, these results suggest that salidroside protects SN4741 cells and primary cortical neurons from 6-OHDA-induced neurotoxicity by attenuating ER stress. This provides a rationale for the investigation of salidroside as a potential therapeutic agent in animal models of PD.

  6. A highly sensitive assay for monitoring the secretory pathway and ER stress.

    Directory of Open Access Journals (Sweden)

    Christian E Badr

    2007-06-01

    Full Text Available The secretory pathway is a critical index of the capacity of cells to incorporate proteins into cellular membranes and secrete proteins into the extracellular space. Importantly it is disrupted in response to stress to the endoplasmic reticulum that can be induced by a variety of factors, including expression of mutant proteins and physiologic stress. Activation of the ER stress response is critical in the etiology of a number of diseases, such as diabetes and neurodegeneration, as well as cancer. We have developed a highly sensitive assay to monitor processing of proteins through the secretory pathway and endoplasmic reticulum (ER stress in real-time based on the naturally secreted Gaussia luciferase (Gluc.An expression cassette for Gluc was delivered to cells, and its secretion was monitored by measuring luciferase activity in the conditioned medium. Gluc secretion was decreased down to 90% when these cells were treated with drugs that interfere with the secretory pathway at different steps. Fusing Gluc to a fluorescent protein allowed quantitation and visualization of the secretory pathway in real-time. Expression of this reporter protein did not itself elicit an ER stress response in cells; however, Gluc proved very sensitive at sensing this type of stress, which is associated with a temporary decrease in processing of proteins through the secretory pathway. The Gluc secretion assay was over 20,000-fold more sensitive as compared to the secreted alkaline phosphatase (SEAP, a well established assay for monitoring of protein processing and ER stress in mammalian cells.The Gluc assay provides a fast, quantitative and sensitive technique to monitor the secretory pathway and ER stress and its compatibility with high throughput screening will allow discovery of drugs for treatment of conditions in which the ER stress is generally induced.

  7. JNK interaction with Sab mediates ER stress induced inhibition of mitochondrial respiration and cell death.

    Science.gov (United States)

    Win, S; Than, T A; Fernandez-Checa, J C; Kaplowitz, N

    2014-01-09

    Our aim was to better understand the mechanism and importance of sustained c-Jun N-terminal kinase (JNK) activation in endoplasmic reticulum (ER) stress and effects of ER stress on mitochondria by determining the role of mitochondrial JNK binding protein, Sab. Tunicamycin or brefeldin A induced a rapid and marked decline in basal mitochondrial respiration and reserve-capacity followed by delayed mitochondrial-mediated apoptosis. Knockdown of mitochondrial Sab prevented ER stress-induced sustained JNK activation, impaired respiration, and apoptosis, but did not alter the magnitude or time course of activation of ER stress pathways. P-JNK plus adenosine 5'-triphosphate (ATP) added to isolated liver mitochondria promoted superoxide production, which was amplified by addition of calcium and inhibited by a blocking peptide corresponding to the JNK binding site on Sab (KIM1). This peptide also blocked tunicamycin-induced inhibition of cellular respiration. In conclusion, ER stress triggers an interaction of JNK with mitochondrial Sab, which leads to impaired respiration and increased mitochondrial reactive oxygen species, sustaining JNK activation culminating in apoptosis.

  8. Purple perilla extracts allay ER stress in lipid-laden macrophages.

    Directory of Open Access Journals (Sweden)

    Sin-Hye Park

    Full Text Available There is a growing body of evidence that excess lipids, hypoxic stress and other inflammatory signals can stimulate endoplasmic reticulum (ER stress in metabolic diseases. However, the pathophysiological importance and the underlying mechanisms of this phenomenon remain unknown. The current study investigated that 50 ng/ml oxidized LDL promoted unfolded protein response (UPR and ER stress in J774A1 murine macrophages, which was blocked by extracts (PPE of purple Perilla frutescens, a plant of the mint family Lamiaceae. The ER stressor tunicamycin was employed as a positive control. Treating 1-10 µg/ml oxidized LDL for 24 h elicited lipotoxic apoptosis in macrophages with obvious nuclear condensation and DNA fragmentation, which was inhibited by PPE. Tunicamycin and oxidized LDL activated and induced the UPR components of activating transcription factor 6 and ER resident chaperone BiP/Grp78 in temporal manners and such effects were blocked by ≥5 µg/ml PPE. In addition, PPE suppressed the enhanced mRNA transcription and splicing of X-box binding protein 1 (XBP1 by tunicamycin and oxidized LDL. The protein induction and nuclear translocation of XBP1 were deterred in PPE-treated macrophages under ER stress. The induction of ATP-binding cassette transporter A1 (ABCA1, scavenger receptor-B1 (SR-B1 and intracellular adhesion molecule-1 (ICAM-1 was abolished by the ER stressor in activated macrophages. The protein induction of ABCA1 and ICAM1 but not SR-B1 was retrieved by adding 10 µg/ml PPE to cells. These results demonstrate that PPE inhibited lipotoxic apoptosis and demoted the induction and activation of UPR components in macrophages. PPE restored normal proteostasis in activated macrophages oxidized LDL. Therefore, PPE was a potent agent antagonizing macrophage ER stress due to lipotoxic signals associated with atherosclerosis.

  9. Shiga Toxins: Intracellular Trafficking to the ER Leading to Activation of Host Cell Stress Responses

    Directory of Open Access Journals (Sweden)

    Moo-Seung Lee

    2010-06-01

    Full Text Available Despite efforts to improve hygenic conditions and regulate food and drinking water safety, the enteric pathogens, Shiga toxin-producing Escherichia coli (STEC and Shigella dysenteriae serotype 1 remain major public health concerns due to widespread outbreaks and the severity of extra-intestinal diseases they cause, including acute renal failure and central nervous system complications. Shiga toxins are the key virulence factors expressed by these pathogens mediating extra-intestinal disease. Delivery of the toxins to the endoplasmic reticulum (ER results in host cell protein synthesis inhibition, activation of the ribotoxic stress response, the ER stress response, and in some cases, the induction of apoptosis. Intrinsic and/or extrinsic apoptosis inducing pathways are involved in executing cell death following intoxication. In this review we provide an overview of the current understanding Shiga toxin intracellular trafficking, host cellular responses to the toxin and ER stress-induced apoptosis with an emphasis on recent findings.

  10. Cocaine induces astrocytosis through ER stress-mediated activation of autophagy

    Science.gov (United States)

    Periyasamy, Palsamy; Guo, Ming-Lei; Buch, Shilpa

    2016-01-01

    ABSTRACT Cocaine is known to induce inflammation, thereby contributing in part, to the pathogenesis of neurodegeneration. A recent study from our lab has revealed a link between macroautophagy/autophagy and microglial activation. The current study was aimed at investigating whether cocaine could also mediate activation of astrocytes and, whether this process involved induction of autophagy. Our findings demonstrated that cocaine mediated the activation of astrocytes by altering the levels of autophagy markers, such as BECN1, ATG5, MAP1LC3B-II, and SQSTM1 in both human A172 astrocytoma cells and primary human astrocytes. Furthermore, cocaine treatment resulted in increased formation of endogenous MAP1LC3B puncta in human astrocytes. Additionally, astrocytes transfected with the GFP-MAP1LC3B plasmid also demonstrated cocaine-mediated upregulation of the green fluorescent MAP1LC3B puncta. Cocaine-mediated induction of autophagy involved upstream activation of ER stress proteins such as EIF2AK3, ERN1, ATF6 since blockage of autophagy using either pharmacological or gene-silencing approaches, had no effect on cocaine-mediated induction of ER stress. Using both pharmacological and gene-silencing approaches to block either ER stress or autophagy, our findings demonstrated that cocaine-induced activation of astrocytes (measured by increased levels of GFAP) involved sequential activation of ER stress and autophagy. Cocaine-mediated-increased upregulation of GFAP correlated with increased expression of proinflammatory mediators such as TNF, IL1B, and IL6. In conclusion, these findings reveal an association between ER stress-mediated autophagy and astrogliosis in cocaine-treated astrocytes. Intervention of ER stress and/or autophagy signaling would thus be promising therapeutic targets for abrogating cocaine-mediated neuroinflammation. PMID:27337297

  11. β cell ER stress and the implications for immunogenicity in type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Meghan L. Marre

    2015-10-01

    Full Text Available Type 1 diabetes (T1D is a chronic autoimmune disease characterized by hyperglycemia due to progressive immune-mediated destruction of insulin-producing pancreatic islet β cells. Although many elegant studies have identified β cell autoantigens that are targeted by the autoimmune response, the mechanisms by which these autoantigens are generated remain poorly understood. Normal β cell physiology includes a high demand for insulin production and secretion in response to dynamic glucose sensing. This secretory function predisposes β cells to significantly higher levels of endoplasmic reticulum (ER stress compared to nonsecretory cells. In addition, many environmental triggers associated with T1D onset further augment this inherent ER stress in β cells. ER stress may increase abnormal post-translational modification (PTM of endogenous β cell proteins. Indeed, in other autoimmune disorders such as celiac disease, systemic lupus erythematosus, multiple sclerosis, and rheumatoid arthritis, abnormally modified neo-antigens are presented by antigen presenting cells in draining lymph nodes. In the context of genetic susceptibility to autoimmunity, presentation of neo-antigens activates auto-reactive T cells and pathology ensues. Therefore, the ER stress induced by normal β cell secretory physiology and environmental triggers may be sufficient to generate neo-antigens for the autoimmune response in T1D. This review summarizes what is currently known about ER stress and protein PTM in target organs of other autoimmune disease models, as well as the data supporting a role for ER stress-induced neo-antigen formation in β cells in T1D.

  12. Breast Cancer Survival Defined by the ER/PR/HER2 Subtypes and a Surrogate Classification according to Tumor Grade and Immunohistochemical Biomarkers

    Directory of Open Access Journals (Sweden)

    Carol A. Parise

    2014-01-01

    Full Text Available Introduction. ER, PR, and HER2 are routinely available in breast cancer specimens. The purpose of this study is to contrast breast cancer-specific survival for the eight ER/PR/HER2 subtypes with survival of an immunohistochemical surrogate for the molecular subtype based on the ER/PR/HER2 subtypes and tumor grade. Methods. We identified 123,780 cases of stages 1–3 primary female invasive breast cancer from California Cancer Registry. The surrogate classification was derived using ER/PR/HER2 and tumor grade. Kaplan-Meier survival analysis and Cox proportional hazards modeling were used to assess differences in survival and risk of mortality for the ER/PR/HER2 subtypes and surrogate classification within each stage. Results. The luminal B/HER2− surrogate classification had a higher risk of mortality than the luminal B/HER2+ for all stages of disease. There was no difference in risk of mortality between the ER+/PR+/HER2− and ER+/PR+/HER2+ in stage 3. With one exception in stage 3, the ER-negative subtypes all had an increased risk of mortality when compared with the ER-positive subtypes. Conclusions. Assessment of survival using ER/PR/HER2 illustrates the heterogeneity of HER2+ subtypes. The surrogate classification provides clear separation in survival and adjusted mortality but underestimates the wide variability within the subtypes that make up the classification.

  13. ER stress response plays an important role in aggregation of α-synuclein.

    Science.gov (United States)

    Jiang, Peizhou; Gan, Ming; Ebrahim, Abdul Shukkur; Lin, Wen-Lang; Melrose, Heather L; Yen, Shu-Hui C

    2010-12-13

    Accumulation of filamentous α-synuclein as Lewy bodies is a hallmark of Parkinson's disease. To identify the mechanisms involved in α-synuclein assembly and determine whether the assemblies are cytotoxic, we developed a cell model (3D5) that inducibly expresses wild-type human α-synuclein and forms inclusions that reproduce many morphological and biochemical characteristics of Lewy bodies. In the present study, we evaluated the effects of several histone deacetylase inhibitors on α-synuclein aggregation in 3D5 cells and primary neuronal cultures. These drugs have been demonstrated to protect cells transiently overexpressing α-synuclein from its toxicity. Contrary to transient transfectants, the drug treatment did not benefit 3D5 cells and primary cultures. The treated were less viable and contained more α-synuclein oligomers, active caspases 3 and 9, as well as ER stress markers than non-treated counterparts. The drug-treated, induced-3D5 cells, or primary cultures from transgenic mice overexpressing (<2 fold) α-synuclein, displayed more α-synuclein oligomers and ER stress markers than non-induced or non-transgenic counterparts. Similar effects were demonstrated in cultures treated with tunicamycin, an ER stressor. These effects were blocked by co-treatment with salubrinal, an ER stress inhibitor. In comparison, co-treatment with a pan caspase inhibitor protected cells from demise but did not reduce α-synuclein oligomer accumulation. Our results indicate that an increase of wild-type α-synuclein can elicit ER stress response and sensitize cells to further insults. Most importantly, an increase of ER stress response can promote the aggregation of wild type α-synuclein.

  14. Glucose Regulation of Load‐Induced mTOR Signaling and ER Stress in Mammalian Heart

    Science.gov (United States)

    Sen, Shiraj; Kundu, Bijoy K.; Wu, Henry Cheng‐Ju; Hashmi, S. Shahrukh; Guthrie, Patrick; Locke, Landon W.; Roy, R. Jack; Matherne, G. Paul; Berr, Stuart S.; Terwelp, Matthew; Scott, Brian; Carranza, Sylvia; Frazier, O. Howard; Glover, David K.; Dillmann, Wolfgang H.; Gambello, Michael J.; Entman, Mark L.; Taegtmeyer, Heinrich

    2013-01-01

    Background Changes in energy substrate metabolism are first responders to hemodynamic stress in the heart. We have previously shown that hexose‐6‐phosphate levels regulate mammalian target of rapamycin (mTOR) activation in response to insulin. We now tested the hypothesis that inotropic stimulation and increased afterload also regulate mTOR activation via glucose 6‐phosphate (G6P) accumulation. Methods and Results We subjected the working rat heart ex vivo to a high workload in the presence of different energy‐providing substrates including glucose, glucose analogues, and noncarbohydrate substrates. We observed an association between G6P accumulation, mTOR activation, endoplasmic reticulum (ER) stress, and impaired contractile function, all of which were prevented by pretreating animals with rapamycin (mTOR inhibition) or metformin (AMPK activation). The histone deacetylase inhibitor 4‐phenylbutyrate, which relieves ER stress, also improved contractile function. In contrast, adding the glucose analogue 2‐deoxy‐d‐glucose, which is phosphorylated but not further metabolized, to the perfusate resulted in mTOR activation and contractile dysfunction. Next we tested our hypothesis in vivo by transverse aortic constriction in mice. Using a micro‐PET system, we observed enhanced glucose tracer analog uptake and contractile dysfunction preceding dilatation of the left ventricle. In contrast, in hearts overexpressing SERCA2a, ER stress was reduced and contractile function was preserved with hypertrophy. Finally, we examined failing human hearts and found that mechanical unloading decreased G6P levels and ER stress markers. Conclusions We propose that glucose metabolic changes precede and regulate functional (and possibly also structural) remodeling of the heart. We implicate a critical role for G6P in load‐induced mTOR activation and ER stress. PMID:23686371

  15. HDAC5 Integrates ER Stress and Fasting Signals to Regulate Hepatic Fatty Acid Oxidation.

    Science.gov (United States)

    Qiu, Xinchen; Li, Jian; Lv, Sihan; Yu, Jiamin; Jiang, Junkun; Yao, Jindong; Xiao, Yang; Xu, Bingxin; He, Haiyan; Guo, Fangfei; Zhang, Zhen-Ning; Zhang, Chao; Luan, Bing

    2017-12-11

    Disregulation of fatty acid oxidation, one of the major mechanisms to maintain hepatic lipid homeostasis under fasting conditions, leads to hepatic steatosis. Although obesity and type 2 diabetes-induced ER stress contributes to hepatic steatosis, it is largely unknown how ER stress regulates fatty acid oxidation. Here we show that fasting glucagon stimulates the dephosphorylation and nuclear translocation of HDAC5, where it interacts with PPARα and promotes transcriptional activity of PPARα. As a result, overexpression of HDAC5 but not PPARα binding-deficient HDAC5 in liver improves lipid homeostasis, while RNAi-mediated knockdown of HDAC5 deteriorates hepatic steatosis. ER stress inhibits fatty acid oxidation gene expression via CaMKII-mediated phosphorylation of HDAC5. Most importantly, hepatic overexpression of a phosphorylation-deficient mutant HDAC5 2SA promotes hepatic fatty acid oxidation gene expression, and protects against hepatic steatosis in high-fat-diet (HFD) fed mice. Taken together, we have identified HDAC5 as a novel mediator of hepatic fatty acid oxidation by fasting and ER stress signals and strategies to promote HDAC5 dephosphorylation could serve as new tools for the treatment of obesity-associated hepatic steatosis. Copyright © 2017, The American Society for Biochemistry and Molecular Biology.

  16. The ER stress inducer DMC enhances TRAIL-induced apoptosis in glioblastoma

    NARCIS (Netherlands)

    van Roosmalen, Ingrid A. M.; Dos Reis, Carlos R; Setroikromo, Rita; Yuvaraj, Saravanan; Joseph, Justin V.; Tepper, Pieter G.; Kruyt, Frank A. E.; Quax, Wim J.

    2014-01-01

    Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumour in humans and is highly resistant to current treatment modalities. We have explored the combined treatment of the endoplasmic reticulum (ER) stress-inducing agent 2,5-dimethyl-celecoxib (DMC) and TNF-related

  17. Shikonin ameliorates isoproterenol (ISO)-induced myocardial damage through suppressing fibrosis, inflammation, apoptosis and ER stress.

    Science.gov (United States)

    Yang, Jun; Wang, Zhao; Chen, Dong-Lin

    2017-09-01

    Shikonin, isolated from the roots of herbal plant Lithospermum erythrorhizon, is a naphthoquinone. It has been reported to exert beneficial anti-inflammatory effects and anti-oxidant properties in various diseases. Isoproterenol (ISO) has been widely used to establish cardiac injury in vivo and in vitro. However, shikonin function in ISO-induced cardiac injury remains uncertain. In our study, we attempted to investigate the efficiency and possible molecular mechanism of shikonin in cardiac injury treatment induced by ISO. In vivo, C57BL6 mice were subcutaneously injected with 5mg/kg ISO to induce heart failure. And mice were given a gavage of shikonin (2 or 4mg/kg/d, for four weeks). Cardiac function, fibrosis indices, inflammation response, apoptosis and endoplasmic reticulum (ER) stress were calculated. Pathological alterations, fibrosis-, inflammation-, apoptosis- and ER stress-related molecules were examined. In ISO-induced cardiac injury, shikonin significantly ameliorated heart function, decreased myocardial fibrosis, suppressed inflammation, attenuated apoptosis and ER stress through impeding collagen accumulation, Toll like receptor 4/nuclear transcription factor κB (TLR4/NF-κB), Caspase-3 and glucose-regulated protein 78 (GRP78) signaling pathways activity, relieving heart failure in vivo. Also, in vitro, shikonin attenuated ISO-induced cardiac muscle cells by reducing fibrosis, inflammation, apoptosis and ER stress. Our findings indicated that shikonin treatment attenuated ISO-induced heart injury, providing an effective therapeutic strategy for heart failure treatment for future. Copyright © 2017. Published by Elsevier Masson SAS.

  18. Aging related ER stress is not responsible for anabolic resistance in mouse skeletal muscle

    NARCIS (Netherlands)

    Chalil, S.; Pierre, N.; Bakker, A.D.; Manders, R.J.; Pletsers, A.; Francaux, M.; Klein-Nulend, J.; Jaspers, R.T.; Deldique, L.

    2015-01-01

    Anabolic resistance reflects the inability of skeletal muscle to maintain protein mass by appropriate stimulation of protein synthesis. We hypothesized that endoplasmic reticulum (ER) stress contributes to anabolic resistance in skeletal muscle with aging. Muscles were isolated from adult (8 mo) and

  19. Feedback regulation on PTEN/AKT pathway by the ER stress kinase PERK mediated by interaction with the Vault complex

    DEFF Research Database (Denmark)

    Zhang, Wei; Neo, Suat Peng; Gunaratne, Jayantha

    2015-01-01

    The high proliferation rate of cancer cells, together with environmental factors such as hypoxia and nutrient deprivation can cause Endoplasmic Reticulum (ER) stress. The protein kinase PERK is an essential mediator in one of the three ER stress response pathways. Genetic and pharmacological inhi...

  20. Endoplasmic reticulum (ER) localization is critical for DsbA-L protein to suppress ER stress and adiponectin down-regulation in adipocytes.

    Science.gov (United States)

    Liu, Meilian; Chen, Hongzhi; Wei, Li; Hu, Derong; Dong, Kun; Jia, Weiping; Dong, Lily Q; Liu, Feng

    2015-04-17

    Adiponectin is an adipokine with insulin-sensitizing and anti-inflammatory functions. We previously reported that adiponectin multimerization and stability are promoted by the disulfide bond A oxidoreductase-like protein (DsbA-L) in cells and in vivo. However, the precise mechanism by which DsbA-L regulates adiponectin biosynthesis remains elusive. Here we show that DsbA-L is co-localized with the endoplasmic reticulum (ER) marker protein disulfide isomerase and the mitochondrial marker MitoTracker. In addition, DsbA-L interacts with the ER chaperone protein Ero1-Lα in 3T3-L1 adipocytes. In silico analysis and truncation mapping studies revealed that DsbA-L contains an ER targeting signal at its N terminus. Deletion of the first 6 residues at the N terminus greatly impaired DsbA-L localization in the ER. Overexpression of the wild type but not the ER localization-defective mutant of DsbA-L protects against thapsigargin-induced ER stress and adiponectin down-regulation in 3T3-L1 adipocytes. In addition, overexpression of the wild type but not the ER localization-defective mutant of DsbA-L promotes adiponectin multimerization. Together, our results reveal that DsbA-L is localized in both the mitochondria and the ER in adipocytes and that its ER localization plays a critical role in suppressing ER stress and promoting adiponectin biosynthesis and secretion. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Sex differences play a role in cardiac endoplasmic reticulum stress (ERS) and ERS-initiated apoptosis induced by pressure overload and thapsigargin.

    Science.gov (United States)

    Sari, Flori R; Watanabe, Kenichi; Widyantoro, Bambang; Thandavarayan, Rajarajan A; Harima, Meilei; Kodama, Makoto; Aizawa, Yoshifusa

    2011-01-01

    Excessive endoplasmic reticulum stress (ERS) triggers myocardial apoptosis. Sex differences appear to be an important determinant in the occurrence of stress and apoptosis through many pathways, but the roles of sex differences in the cardiac ERS and ERS-initiated apoptosis are largely unknown. In the present study, we investigated the in vivo role of sex differences in the cardiac ERS and apoptosis elicited by ascending aortic banding surgery or thapsigargin (Thap) injection using male and female C57BL/6 JAX mice. The surgery significantly increased the expression levels of cardiac glucose-regulated protein (GRP)78 and CCAAT/enhancer binding protein homology protein (CHOP) protein, increased the myocardial apoptosis and decreased the sarcoplasmic reticulum Ca(2+)-ATPase isoform (SERCA)2 immunoreactivity in the male mice relative to female mice. Furthermore, during ERS induction using Thap, myocardial apoptosis and the expression levels of cardiac GRP78, inositol-requiring enzyme (Ire)1α and tumor necrosis factor receptor-associated factor (TRAF)2 were significantly increased in male mice relative to female mice. Sex differences significantly affected the above results. Our data suggest that sex differences affected the response of myocardial tissues in dealing with cardiac ERS and further result of ERS, apoptosis, at least in part through the regulation of SERCA2, CHOP, Ire1α and TRAF2. Copyright © 2011. Published by Elsevier Inc.

  2. Tissue factor pathway inhibitor attenuates ER stress-induced inflammation in human M2-polarized macrophages.

    Science.gov (United States)

    Espada, Sandra; Stavik, Benedicte; Holm, Sverre; Sagen, Ellen Lund; Bjerkeli, Vigdis; Skjelland, Mona; Dahl, Tuva B; Espevik, Terje; Kanse, Sandip; Sandset, Per Morten; Skretting, Grethe; Halvorsen, Bente

    2017-09-16

    Endoplasmic reticulum (ER) stress has been shown to play a key role during the initiation and clinical progression of the cardiovascular diseases, such as atherosclerosis. We have recently shown that expression of tissue factor pathway inhibitor (TFPI) in human monocyte-derived macrophages (MDMs) was induced by cholesterol crystals (CC). In the present study we aimed to determine the role of TFPI under ER stress conditions using human MDMs. qRT-PCR and immunohistochemistry analysis were performed to determine the presence of the ER stress marker CCAAT/enhancer binding protein homologous protein (CHOP) and TFPI in human carotid plaque material and also in human MDMs polarized into pro-inflammatory M1 or anti-inflammatory M2 populations. CHOP mRNA levels were upregulated in the plaques compared to healthy vessels, and CHOP protein was localized in the same area as TFPI in the plaques. Both CHOP and TFPI mRNA levels were upregulated after CC treatment, especially in the M2 phenotype, and the ER stress inhibitor 4-phenylbutyric acid (PBA) reversed this effect. Furthermore, CC treatment increased the levels of the pro-inflammatory cytokines TNF-α, IL-6, and IL-8, which for TNF-α and IL-8 was inhibited by PBA, and reduced the levels of the anti-inflammatory cytokine IL-10 in M2-polarized macrophages. Knockdown of TFPI prior to CC treatment exacerbated TNF-α and IL-6 levels, but reduced IL-8 and IL-10 levels. Our results show that CC induce TFPI and cytokine expression in M2-polarized macrophages through activation of the ER stress pathway and that TFPI has a protective effect against TNF-α and IL-6 mediated inflammation. These mechanisms may have implications for the pathogenesis of atherosclerosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Resveratrol enhances palmitate-induced ER stress and apoptosis in cancer cells.

    Directory of Open Access Journals (Sweden)

    Cristina Rojas

    Full Text Available Palmitate, a saturated fatty acid (FA, is known to induce toxicity and cell death in various types of cells. Resveratrol (RSV is able to prevent pathogenesis and/or decelerate the progression of a variety of diseases. Several in vitro and in vivo studies have also shown a protective effect of RSV on fat accumulation induced by FAs. Additionally, endoplasmic reticulum (ER stress has recently been linked to cellular adipogenic responses. To address the hypothesis that the RSV effect on excessive fat accumulation promoted by elevated saturated FAs could be partially mediated by a reduction of ER stress, we studied the RSV action on experimentally induced ER stress using palmitate in several cancer cell lines.We show that, unexpectedly, RSV promotes an amplification of palmitate toxicity and cell death and that this mechanism is likely due to a perturbation of palmitate accumulation in the triglyceride form and to a less important membrane fluidity variation. Additionally, RSV decreases radical oxygen species (ROS generation in palmitate-treated cells but leads to enhanced X-box binding protein-1 (XBP1 splicing and C/EBP homologous protein (CHOP expression. These molecular effects are induced simultaneously to caspase-3 cleavage, suggesting that RSV promotes palmitate lipoapoptosis primarily through an ER stress-dependent mechanism. Moreover, the lipotoxicity reversion induced by eicosapentaenoic acid (EPA or by a liver X receptor (LXR agonist reinforces the hypothesis that RSV-mediated inhibition of palmitate channeling into triglyceride pools could be a key factor in the aggravation of palmitate-induced cytotoxicity.Our results suggest that RSV exerts its cytotoxic role in cancer cells exposed to a saturated FA context primarily by triglyceride accumulation inhibition, probably leading to an intracellular palmitate accumulation that triggers a lipid-mediated cell death. Additionally, this cell death is promoted by ER stress through a CHOP

  4. Takotsubo-kardiomyopati er akut hjertesvigt induceret af stress

    DEFF Research Database (Denmark)

    Fuchs, Annette Maria; Bang, Lia Evi; Holmvang, Lene

    2016-01-01

    angiography, and regional akinesia is not limited to a single vascular territory. As opposed to other cardiomyopathies TTC is completely reversible, albeit with a 5% mortality rate as well as a 10% re-occurrence rate. This article summarizes the current knowledge about aetiology, diagnostics and treatment.......Takotsubo cardiomyopathy (TTC) is an acute cardiac syndrome, characterized by transient left ventricular dysfunction often following a stressful event in post-menopausal women. Symptoms are indistinguishable from myocardial infarction. However, TTC patients do not have a culprit lesion on acute...

  5. Heme Degradation by Heme Oxygenase Protects Mitochondria but Induces ER Stress via Formed Bilirubin

    Directory of Open Access Journals (Sweden)

    Andrea Müllebner

    2015-04-01

    Full Text Available Heme oxygenase (HO, in conjunction with biliverdin reductase, degrades heme to carbon monoxide, ferrous iron and bilirubin (BR; the latter is a potent antioxidant. The induced isoform HO-1 has evoked intense research interest, especially because it manifests anti-inflammatory and anti-apoptotic effects relieving acute cell stress. The mechanisms by which HO mediates the described effects are not completely clear. However, the degradation of heme, a strong pro-oxidant, and the generation of BR are considered to play key roles. The aim of this study was to determine the effects of BR on vital functions of hepatocytes focusing on mitochondria and the endoplasmic reticulum (ER. The affinity of BR to proteins is a known challenge for its exact quantification. We consider two major consequences of this affinity, namely possible analytical errors in the determination of HO activity, and biological effects of BR due to direct interaction with protein function. In order to overcome analytical bias we applied a polynomial correction accounting for the loss of BR due to its adsorption to proteins. To identify potential intracellular targets of BR we used an in vitro approach involving hepatocytes and isolated mitochondria. After verification that the hepatocytes possess HO activity at a similar level as liver tissue by using our improved post-extraction spectroscopic assay, we elucidated the effects of increased HO activity and the formed BR on mitochondrial function and the ER stress response. Our data show that BR may compromise cellular metabolism and proliferation via induction of ER stress. ER and mitochondria respond differently to elevated levels of BR and HO-activity. Mitochondria are susceptible to hemin, but active HO protects them against hemin-induced toxicity. BR at slightly elevated levels induces a stress response at the ER, resulting in a decreased proliferative and metabolic activity of hepatocytes. However, the proteins that are targeted

  6. Calorie-induced ER stress suppresses uroguanylin satiety signaling in diet-induced obesity.

    Science.gov (United States)

    Kim, G W; Lin, J E; Snook, A E; Aing, A S; Merlino, D J; Li, P; Waldman, S A

    2016-05-23

    The uroguanylin-GUCY2C gut-brain axis has emerged as one component regulating feeding, energy homeostasis, body mass and metabolism. Here, we explore a role for this axis in mechanisms underlying diet-induced obesity (DIO). Intestinal uroguanylin expression and secretion, and hypothalamic GUCY2C expression and anorexigenic signaling, were quantified in mice on high-calorie diets for 14 weeks. The role of endoplasmic reticulum (ER) stress in suppressing uroguanylin in DIO was explored using tunicamycin, an inducer of ER stress, and tauroursodeoxycholic acid (TUDCA), a chemical chaperone that inhibits ER stress. The impact of consumed calories on uroguanylin expression was explored by dietary manipulation. The role of uroguanylin in mechanisms underlying obesity was examined using Camk2a-Cre-ER(T2)-Rosa-STOP(loxP/loxP)-Guca2b mice in which tamoxifen induces transgenic hormone expression in brain. DIO suppressed intestinal uroguanylin expression and eliminated its postprandial secretion into the circulation. DIO suppressed uroguanylin through ER stress, an effect mimicked by tunicamycin and blocked by TUDCA. Hormone suppression by DIO reflected consumed calories, rather than the pathophysiological milieu of obesity, as a diet high in calories from carbohydrates suppressed uroguanylin in lean mice, whereas calorie restriction restored uroguanylin in obese mice. However, hypothalamic GUCY2C, enriched in the arcuate nucleus, produced anorexigenic signals mediating satiety upon exogenous agonist administration, and DIO did not impair these responses. Uroguanylin replacement by transgenic expression in brain repaired the hormone insufficiency and reconstituted satiety responses opposing DIO and its associated comorbidities, including visceral adiposity, glucose intolerance and hepatic steatosis. These studies reveal a novel pathophysiological mechanism contributing to obesity in which calorie-induced suppression of intestinal uroguanylin impairs hypothalamic mechanisms

  7. Curcumin attenuates glutamate neurotoxicity in the hippocampus by suppression of ER stress-associated TXNIP/NLRP3 inflammasome activation in a manner dependent on AMPK

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying; Li, Jia; Li, Shanshan; Li, Yi; Wang, Xiangxiang; Liu, Baolin [Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 639, Longmian Road, Nanjing 211198 (China); Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Research, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198 (China); Fu, Qiang, E-mail: fuqiang@cpu.edu.cn [Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 639, Longmian Road, Nanjing 211198 (China); Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Research, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198 (China); Ma, Shiping, E-mail: spma@cpu.edu.cn [Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 639, Longmian Road, Nanjing 211198 (China); Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Research, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198 (China)

    2015-07-01

    Curcumin is a natural polyphenolic compound in Curcuma longa with beneficial effects on neuronal protection. This study aims to investigate the action of curcumin in the hippocampus subjected to glutamate neurotoxicity. Glutamate stimulation induced reactive oxygen species (ROS), endoplasmic reticulum stress (ER stress) and TXNIP/NLRP3 inflammasome activation, leading to damage in the hippocampus. Curcumin treatment in the hippocampus or SH-SY5Y cells inhibited IRE1α and PERK phosphorylation with suppression of intracellular ROS production. Curcumin increased AMPK activity and knockdown of AMPKα with specific siRNA abrogated its inhibitory effects on IRE1α and PERK phosphorylation, indicating that AMPK activity was essential for the suppression of ER stress. As a result, curcumin reduced TXNIP expression and inhibited NLRP3 inflammasome activation by downregulation of NLRP3 and cleaved caspase-1 induction, and thus reduced IL-1β secretion. Specific fluorescent probe and flow cytometry analysis showed that curcumin prevented mitochondrial malfunction and protected cell survival from glutamate neurotoxicity. Moreover, oral administration of curcumin reduced brain infarct volume and attenuated neuronal damage in rats subjected to middle cerebral artery occlusion. Immunohistochemistry showed that curcumin inhibited p-IRE1α, p-PERK and NLRP3 expression in hippocampus CA1 region. Together, these results showed that curcumin attenuated glutamate neurotoxicity by inhibiting ER stress-associated TXNIP/NLRP3 inflammasome activation via the regulation of AMPK, and thereby protected the hippocampus from ischemic insult. - Highlights: • Curcumin attenuates glutamate neurotoxicity in the hippocampus. • Curcumin suppresses ER stress in glutamate-induced hippocampus slices. • Curcumin inhibits TXNIP/NLRP3 inflammasome activation. • Regulation of AMPK by curcumin contributes to suppressing ER stress.

  8. A sphingolipid-dependent diffusion barrier confines ER stress to the yeast mother cell

    Science.gov (United States)

    Clay, Lori; Caudron, Fabrice; Denoth-Lippuner, Annina; Boettcher, Barbara; Buvelot Frei, Stéphanie; Snapp, Erik Lee; Barral, Yves

    2014-01-01

    In many cell types, lateral diffusion barriers compartmentalize the plasma membrane and, at least in budding yeast, the endoplasmic reticulum (ER). However, the molecular nature of these barriers, their mode of action and their cellular functions are unclear. Here, we show that misfolded proteins of the ER remain confined into the mother compartment of budding yeast cells. Confinement required the formation of a lateral diffusion barrier in the form of a distinct domain of the ER-membrane at the bud neck, in a septin-, Bud1 GTPase- and sphingolipid-dependent manner. The sphingolipids, but not Bud1, also contributed to barrier formation in the outer membrane of the dividing nucleus. Barrier-dependent confinement of ER stress into the mother cell promoted aging. Together, our data clarify the physical nature of lateral diffusion barriers in the ER and establish the role of such barriers in the asymmetric segregation of proteotoxic misfolded proteins during cell division and aging. DOI: http://dx.doi.org/10.7554/eLife.01883.001 PMID:24843009

  9. High-intensity training reduces intermittent hypoxia-induced ER stress and myocardial infarct size.

    Science.gov (United States)

    Bourdier, Guillaume; Flore, Patrice; Sanchez, Hervé; Pepin, Jean-Louis; Belaidi, Elise; Arnaud, Claire

    2016-01-15

    Chronic intermittent hypoxia (IH) is described as the major detrimental factor leading to cardiovascular morbimortality in obstructive sleep apnea (OSA) patients. OSA patients exhibit increased infarct size after a myocardial event, and previous animal studies have shown that chronic IH could be the main mechanism. Endoplasmic reticulum (ER) stress plays a major role in the pathophysiology of cardiovascular disease. High-intensity training (HIT) exerts beneficial effects on the cardiovascular system. Thus, we hypothesized that HIT could prevent IH-induced ER stress and the increase in infarct size. Male Wistar rats were exposed to 21 days of IH (21-5% fraction of inspired O2, 60-s cycle, 8 h/day) or normoxia. After 1 wk of IH alone, rats were submitted daily to both IH and HIT (2 × 24 min, 15-30m/min). Rat hearts were either rapidly frozen to evaluate ER stress by Western blot analysis or submitted to an ischemia-reperfusion protocol ex vivo (30 min of global ischemia/120 min of reperfusion). IH induced cardiac proapoptotic ER stress, characterized by increased expression of glucose-regulated protein kinase 78, phosphorylated protein kinase-like ER kinase, activating transcription factor 4, and C/EBP homologous protein. IH-induced myocardial apoptosis was confirmed by increased expression of cleaved caspase-3. These IH-associated proapoptotic alterations were associated with a significant increase in infarct size (35.4 ± 3.2% vs. 22.7 ± 1.7% of ventricles in IH + sedenary and normoxia + sedentary groups, respectively, P < 0.05). HIT prevented both the IH-induced proapoptotic ER stress and increased myocardial infarct size (28.8 ± 3.9% and 21.0 ± 5.1% in IH + HIT and normoxia + HIT groups, respectively, P = 0.28). In conclusion, these findings suggest that HIT could represent a preventive strategy to limit IH-induced myocardial ischemia-reperfusion damages in OSA patients. Copyright © 2016 the American Physiological Society.

  10. ER Stress Causes Rapid Loss of Intestinal Epithelial Stemness through Activation of the Unfolded Protein Response

    Directory of Open Access Journals (Sweden)

    Jarom Heijmans

    2013-04-01

    Full Text Available Stem cells generate rapidly dividing transit-amplifying cells that have lost the capacity for self-renewal but cycle for a number of times until they exit the cell cycle and undergo terminal differentiation. We know very little of the type of signals that trigger the earliest steps of stem cell differentiation and mediate a stem cell to transit-amplifying cell transition. We show that in normal intestinal epithelium, endoplasmic reticulum (ER stress and activity of the unfolded protein response (UPR are induced at the transition from stem cell to transit-amplifying cell. Induction of ER stress causes loss of stemness in a Perk-eIF2α-dependent manner. Inhibition of Perk-eIF2α signaling results in stem cell accumulation in organoid culture of primary intestinal epithelium. Our findings show that the UPR plays an important role in the regulation of intestinal epithelial stem cell differentiation.

  11. Docosahexaenoic Acid Ameliorates Fructose-Induced Hepatic Steatosis Involving ER Stress Response in Primary Mouse Hepatocytes

    Directory of Open Access Journals (Sweden)

    Jinying Zheng

    2016-01-01

    Full Text Available The increase in fructose consumption is considered to be a risk factor for developing nonalcoholic fatty liver disease (NAFLD. We investigated the effects of docosahexaenoic acid (DHA on hepatic lipid metabolism in fructose-treated primary mouse hepatocytes, and the changes of Endoplasmic reticulum (ER stress pathways in response to DHA treatment. The hepatocytes were treated with fructose, DHA, fructose plus DHA, tunicamycin (TM or fructose plus 4-phenylbutyric acid (PBA for 24 h. Intracellular triglyceride (TG accumulation was assessed by Oil Red O staining. The mRNA expression levels and protein levels related to lipid metabolism and ER stress response were determined by real-time PCR and Western blot. Fructose treatment led to obvious TG accumulation in primary hepatocytes through increasing expression of fatty acid synthase (FAS and acetyl-CoA carboxylase (ACC, two key enzymes in hepatic de novo lipogenesis. DHA ameliorates fructose-induced TG accumulation by upregulating the expression of carnitine palmitoyltransferase 1A (CPT-1α and acyl-CoA oxidase 1 (ACOX1. DHA treatment or pretreatment with the ER stress inhibitor PBA significantly decreased TG accumulation and reduced the expression of glucose-regulated protein 78 (GRP78, total inositol-requiring kinase 1 (IRE1α and p-IRE1α. The present results suggest that DHA protects against high fructose-induced hepatocellular lipid accumulation. The current findings also suggest that alleviating the ER stress response seems to play a role in the prevention of fructose-induced hepatic steatosis by DHA.

  12. Persistent ER stress induces the spliced leader RNA silencing pathway (SLS, leading to programmed cell death in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Hanoch Goldshmidt

    2010-01-01

    Full Text Available Trypanosomes are parasites that cycle between the insect host (procyclic form and mammalian host (bloodstream form. These parasites lack conventional transcription regulation, including factors that induce the unfolded protein response (UPR. However, they possess a stress response mechanism, the spliced leader RNA silencing (SLS pathway. SLS elicits shut-off of spliced leader RNA (SL RNA transcription by perturbing the binding of the transcription factor tSNAP42 to its cognate promoter, thus eliminating trans-splicing of all mRNAs. Induction of endoplasmic reticulum (ER stress in procyclic trypanosomes elicits changes in the transcriptome similar to those induced by conventional UPR found in other eukaryotes. The mechanism of up-regulation under ER stress is dependent on differential stabilization of mRNAs. The transcriptome changes are accompanied by ER dilation and elevation in the ER chaperone, BiP. Prolonged ER stress induces SLS pathway. RNAi silencing of SEC63, a factor that participates in protein translocation across the ER membrane, or SEC61, the translocation channel, also induces SLS. Silencing of these genes or prolonged ER stress led to programmed cell death (PCD, evident by exposure of phosphatidyl serine, DNA laddering, increase in reactive oxygen species (ROS production, increase in cytoplasmic Ca(2+, and decrease in mitochondrial membrane potential, as well as typical morphological changes observed by transmission electron microscopy (TEM. ER stress response is also induced in the bloodstream form and if the stress persists it leads to SLS. We propose that prolonged ER stress induces SLS, which serves as a unique death pathway, replacing the conventional caspase-mediated PCD observed in higher eukaryotes.

  13. Survival responses to oxidative stress and aging.

    Science.gov (United States)

    Miura, Yuri; Endo, Tamao

    2010-07-01

    Oxidative stress is recognized as an important environmental factor in aging; however, because reactive oxygen species (ROS) and related free radicals are normally produced both intra- and extracellularly, air-living organisms cannot avoid the risk of oxidative stress. Consequently, these organisms have evolved various anti-oxidant systems to prevent ROS, scavenge free radicals, repair damaged components and adaptive responses. This review will focus on the repair and adaptive response to oxidative stress, and summarize the changes of these systems as a result aging and their relationship to premature aging.

  14. Levistolide A Induces Apoptosis via ROS-Mediated ER Stress Pathway in Colon Cancer Cells.

    Science.gov (United States)

    Yang, Yingjuan; Zhang, Yanhua; Wang, Lan; Lee, Shaochin

    2017-01-01

    Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. Levistolide A (LA), a natural compound isolated from the traditional Chinese herb Ligusticum chuanxiong Hort, is used for treating cancer. In this study, we investigated the anticancer effect of LA in HCT116 and its isogenic p53-/- colon cancer cells, as well as the underlying mechanisms. MTT assay was used to evaluate the effect of LA on the viability of cancer cells. Apoptosis and reactive oxygen species (ROS) production by the cells were determined by flow cytometry. Protein expression was detected by western blotting. The results showed that LA inhibited viability and caused apoptosis of both wild-type and p53-/- HCT116 cells. LA was able to trigger production of ROS and endoplasmic reticulum (ER) stress. Inhibition of ROS using N-acetylcysteine abrogated LA-induced ER stress and apoptosis, as well as the reduction in cancer cell viability. Our results indicate that LA causes apoptosis of colon cancer cells via ROS-mediated ER stress pathway. It will be interesting to develop the natural compound for chemotherapy of cancers such as CRC. © 2017 The Author(s). Published by S. Karger AG, Basel.

  15. Protectin DX suppresses hepatic gluconeogenesis through AMPK-HO-1-mediated inhibition of ER stress.

    Science.gov (United States)

    Jung, Tae Woo; Kim, Hyung-Chun; Abd El-Aty, A M; Jeong, Ji Hoon

    2017-06-01

    Several studies have shown that protectins, which are ω-3 fatty acid-derived proresolution mediators, may improve insulin resistance. Recently, protectin DX (PDX) was documented to attenuate insulin resistance by stimulating IL-6 expression in skeletal muscle, thereby regulating hepatic gluconeogenesis. These findings made us investigate the direct effects of PDX on hepatic glucose metabolism in the context of diabetes. In the current study, we show that PDX regulates hepatic gluconeogenesis in a manner distinct from its indirect glucoregulatory activity via IL-6. We found that PDX stimulated AMP-activated protein kinase (AMPK) phosphorylation, thereby inducing heme oxygenase 1 (HO-1) expression. This induction blocked hepatic gluconeogenesis by suppressing endoplasmic reticulum (ER) stress in hepatocytes under hyperlipidemic conditions. These effects were significantly dampened by silencing AMPK or HO-1 expression with small interfering RNA (siRNA). We also demonstrated that administration of PDX to high fat diet (HFD)-fed mice resulted in increased hepatic AMPK phosphorylation and HO-1 expression, whereas hepatic ER stress was substantially attenuated. Furthermore, PDX treatment suppressed the expression of gluconeogenic genes, thereby decreasing blood glucose levels in HFD-fed mice. In conclusion, our findings suggest that PDX inhibits hepatic gluconeogenesis via AMPK-HO-1-dependent suppression of ER stress. Thus, PDX may be an effective therapeutic target for the treatment of insulin resistance and type 2 diabetes through the regulation of hepatic gluconeogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Ursodeoxycholic Acid (UDCA) Exerts Anti-Atherogenic Effects by Inhibiting Endoplasmic Reticulum (ER) Stress Induced by Disturbed Flow.

    Science.gov (United States)

    Chung, Jihwa; Kim, Kyoung Hwa; Lee, Seok Cheol; An, Shung Hyun; Kwon, Kihwan

    2015-10-01

    Disturbed blood flow with low-oscillatory shear stress (OSS) is a predominant atherogenic factor leading to dysfunctional endothelial cells (ECs). Recently, it was found that disturbed flow can directly induce endoplasmic reticulum (ER) stress in ECs, thereby playing a critical role in the development and progression of atherosclerosis. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid, has long been used to treat chronic cholestatic liver disease and is known to alleviate endoplasmic reticulum (ER) stress at the cellular level. However, its role in atherosclerosis remains unexplored. In this study, we demonstrated the anti-atherogenic activity of UDCA via inhibition of disturbed flow-induced ER stress in atherosclerosis. UDCA effectively reduced ER stress, resulting in a reduction in expression of X-box binding protein-1 (XBP-1) and CEBP-homologous protein (CHOP) in ECs. UDCA also inhibits the disturbed flow-induced inflammatory responses such as increases in adhesion molecules, monocyte adhesion to ECs, and apoptosis of ECs. In a mouse model of disturbed flow-induced atherosclerosis, UDCA inhibits atheromatous plaque formation through the alleviation of ER stress and a decrease in adhesion molecules. Taken together, our results revealed that UDCA exerts anti-atherogenic activity in disturbed flow-induced atherosclerosis by inhibiting ER stress and the inflammatory response. This study suggests that UDCA may be a therapeutic agent for prevention or treatment of atherosclerosis.

  17. Heat shock preconditioning protects against ER stress-induced apoptosis through the regulation of the BH3-only protein BIM

    Directory of Open Access Journals (Sweden)

    Donna Kennedy

    2014-01-01

    Full Text Available A mild heat shock (HS preconditioning and acquisition of thermotolerance protects cells against a variety of cytotoxic agents that otherwise induce apoptosis. Here we tested whether there is a molecular link between HS preconditioning and endoplasmic reticulum (ER stress-induced apoptosis. ER stress results from a loss of ER lumen homeostasis, culminating in an accumulation of unfolded/misfolded proteins in the ER and activation of unfolded protein response (UPR. Unresolved, ER stress leads to activation of BH3-only proteins, mitochondrial membrane permeabilization, caspase activation and apoptotic cell death. HS preconditioning (1 h at 42 °C induced a rapid increase in HSPA1 (HSP70 levels which remained elevated for at least 48 h post-HS. HS preconditioning significantly reduced BAX, caspase activation and apoptosis in cell cultures treated with the ER stress-inducing agents thapsigargin (TG and tunicamycin (TM. HS-mediated protection was found to be due to regulation of the BH3-only protein BIM. Further, overexpression of HSPA1 could not mimic the effect of HS on BIM expression, suggesting that other HS factors may play a role in inhibiting ER stress-induced apoptosis by regulating BIM.

  18. Some ABCA3 mutations elevate ER stress and initiate apoptosis of lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Holzinger Andreas

    2011-01-01

    Full Text Available Abstract Background ABCA3 transporter (ATP-binding cassette transporter of the A subfamily is localized to the limiting membrane of lamellar bodies, organelles for assembly and storage of pulmonary surfactant in alveolar epithelial type II cells (AECII. It transports surfactant phospholipids into lamellar bodies and absence of ABCA3 function disrupts lamellar body biogenesis. Mutations of the ABCA3 gene lead to fatal neonatal surfactant deficiency and chronic interstitial lung disease (ILD of children. ABCA3 mutations can result in either functional defects of the correctly localized ABCA3 or trafficking/folding defects where mutated ABCA3 remains in the endoplasmic reticulum (ER. Methods Human alveolar epithelial A549 cells were transfected with vectors expressing wild-type ABCA3 or one of the three ABCA3 mutant forms, R43L, R280C and L101P, C-terminally tagged with YFP or hemagglutinin-tag. Localization/trafficking properties were analyzed by immunofluorescence and ABCA3 deglycosylation. Uptake of fluorescent NBD-labeled lipids into lamellar bodies was used as a functional assay. ER stress and apoptotic signaling were examined through RT-PCR based analyses of XBP1 splicing, immunoblotting or FACS analyses of stress/apoptosis proteins, Annexin V surface staining and determination of the intracellular glutathion level. Results We demonstrate that two ABCA3 mutations, which affect ABCA3 protein trafficking/folding and lead to partial (R280C or complete (L101P retention of ABCA3 in the ER compartment, can elevate ER stress and susceptibility to it and induce apoptotic markers in the cultured lung epithelial A549 cells. R43L mutation, resulting in a functional defect of the properly localized ABCA3, had no effect on intracellular stress and apoptotic signaling. Conclusion Our data suggest that expression of partially or completely ER localized ABCA3 mutant proteins can increase the apoptotic cell death of the affected cells, which are factors that

  19. Restoration of autophagy alleviates hepatic ER stress and impaired insulin signalling transduction in high fructose-fed male mice.

    Science.gov (United States)

    Wang, Hao; Sun, Ruo-Qiong; Zeng, Xiao-Yi; Zhou, Xiu; Li, Songpei; Jo, Eunjung; Molero, Juan C; Ye, Ji-Ming

    2015-01-01

    High-carbohydrate (mainly fructose) consumption is a major dietary factor for hepatic insulin resistance, involving endoplasmic reticulum (ER) stress and lipid accumulation. Because autophagy has been implicated in ER stress, the present study investigated the role of autophagy in high-fructose (HFru) diet-induced hepatic ER stress and insulin resistance in male C57BL/6J mice. The results show that chronic HFru feeding induced glucose intolerance and impaired insulin signaling transduction in the liver, associated with ER stress and the accumulation of lipids. Intriguingly, hepatic autophagy was suppressed as a result of activation of mammalian target of rapamycin. The suppressed autophagy was detected within 6 hours after HFru feeding along with activation of both inositol-requiring enzyme 1 and protein kinase RNA-like endoplasmic reticulum kinase pathways. These events occurred prior to lipid accumulation or lipogenesis and were sufficient to blunt insulin signaling transduction with activation of c-Jun N-terminal kinase/inhibitory-κB kinase and serine phosphorylation of insulin receptor substrate 1. The stimulation of autophagy attenuated ER stress- and c-Jun N-terminal kinase/inhibitory-κB kinase-associated impairment in insulin signaling transduction in a mammalian target of rapamycin -independent manner. Taken together, our data suggest that restoration of autophagy functions disrupted by fructose is able to alleviate ER stress and improve insulin signaling transduction.

  20. ER Stress Inhibits Liver Fatty Acid Oxidation while Unmitigated Stress Leads to Anorexia-Induced Lipolysis and Both Liver and Kidney Steatosis

    Directory of Open Access Journals (Sweden)

    Diane DeZwaan-McCabe

    2017-05-01

    Full Text Available The unfolded protein response (UPR, induced by endoplasmic reticulum (ER stress, regulates the expression of factors that restore protein folding homeostasis. However, in the liver and kidney, ER stress also leads to lipid accumulation, accompanied at least in the liver by transcriptional suppression of metabolic genes. The mechanisms of this accumulation, including which pathways contribute to the phenotype in each organ, are unclear. We combined gene expression profiling, biochemical assays, and untargeted lipidomics to understand the basis of stress-dependent lipid accumulation, taking advantage of enhanced hepatic and renal steatosis in mice lacking the ER stress sensor ATF6α. We found that impaired fatty acid oxidation contributed to the early development of steatosis in the liver but not the kidney, while anorexia-induced lipolysis promoted late triglyceride and free fatty acid accumulation in both organs. These findings provide evidence for both direct and indirect regulation of peripheral metabolism by ER stress.

  1. Stress, storage and survival of neem seed

    OpenAIRE

    Sacandé, M.

    2000-01-01

    Neem ( Azadirachta indica ) is an important multipurpose tropical tree species, frequently used in planting programmes in the arid tropics. However, its seeds are difficult to store for extended periods of time, as are those of many other tropical species which display intermediate or recalcitrant storage behaviour. This thesis describes the results of our investigations concerning factors involved in the rapid loss of germinability of neem seeds. Stress and surv...

  2. Fibronectin peptides that bind PDGF-BB enhance survival of cells and tissue under stress

    Science.gov (United States)

    Lin, Fubao; Zhu, Jia; Tonnesen, Marcia G.; Taira, Breena R.; McClain, Steve A.; Singer, Adam J.; Clark, Richard A.F.

    2013-01-01

    Stressors after injury from a multitude of factors can lead to cell death. We have identified four fibronectin (FN) peptides, two from the first FN type III repeat (FNIII1), one from the 13th FN type III repeat (FNIII13), and one from FN variable region (IIICS), that when tethered to a surface acted as platelet-derived growth factor-BB (PDGF-BB) enhancers to promote cell survival. One of the FNIII1 peptides and its smallest (14mer) bioactive form (P12) were also active in solution. Specifically, P12 bound PDGF-BB (KD = 200nM), enhanced adult human dermal fibroblast (AHDF) survival under serum starvation, oxidative or endoplasmic reticulum (ER) stressors, and limited burn injury progression in a rat hot comb model. Furthermore, P12 inhibited ER stress-induced c-Jun N-terminal kinase (JNK) activation. Although many growth factors have been found to bind FN directly or indirectly, this is the first report to identify peptide sequences of growth factor-binding sites in FN. The finding of these novel peptides further delineated how the extracellular matrix protein FN can support cell survival. Since the peptide P12 is active in either soluble form or tethered to a substrate, it will have multifactorial uses as a bioactive in tissue engineering. PMID:24126844

  3. Luteolin induces apoptosis by ROS/ER stress and mitochondrial dysfunction in gliomablastoma.

    Science.gov (United States)

    Wang, Qiang; Wang, Handong; Jia, Yue; Pan, Hao; Ding, Hui

    2017-05-01

    Luteolin, a common dietary flavonoid, induces apoptosis of many types of cancer cells. However, its role in glioblastoma and the potential mechanisms remain unknown. In this research, we studied the molecular mechanisms of the anti-cancer effect of luteolin in glioblastoma cancer cell lines. Both U251MG and U87MG human glioblastoma cell lines were tested. Cell growth was assessed by the cell counting kit-8. Cell apoptosis was detected with flow cytometry and caspase-3 immunofluorescence staining. The protein levels of caspase-3/Bax/Bcl-2 and p-PERK/p-eIF2α/ATF4/CHOP/caspase-12 pathway were analyzed using western blots. Reactive oxygen species generation was measured with DCFH-DA staining using flow cytometry. Mitochondrial membrane potential was tested with JC-1 staining. Anti-cancer effect in vivo was measured using tumor xenograft mode in nude mice. Luteolin induced a lethal endoplasmic reticulum stress response and mitochondrial dysfunction in glioblastoma cells by increasing intracellular reactive oxygen species (ROS) levels. Luteolin induced expression of ER stress-associated proteins, including phosphorylation of PERK, eIF2α, ATF4, CHOP and cleaved-caspase 12. Inhibition of ROS production by anti-oxidant N-acetylcysteine could reverse luteolin-induced ER stress and mitochondrial pathways activation as well as apoptosis. What's more, we also showed the anticancer effect of luteolin in vivo. Our results suggest that luteolin induces apoptosis through activating ER stress and mitochondrial dysfunction in glioblastoma cell lines and in vivo, which provides the anti-cancer candidate to treat glioblstoma.

  4. L-Serine-Mediated Neuroprotection Includes the Upregulation of the ER Stress Chaperone Protein Disulfide Isomerase (PDI).

    Science.gov (United States)

    Dunlop, R A; Powell, J T; Metcalf, J S; Guillemin, G J; Cox, P A

    2018-01-01

    The unfolded protein response (UPR) is a highly evolutionarily conserved response to endoplasmic reticulum (ER) stress, which functions to return cells to homeostasis or send them into apoptosis, depending on the degree of cellular damage. β-N-methylamino-L-alanine (L-BMAA) has been shown to induce ER stress in a variety of models and has been linked to several types of neurodegenerative disease including Guamanian amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC). L-Serine, an amino acid critical for cellular metabolism and neurological signaling, has been shown to be protective against L-BMAA-induced neurotoxicity in both animal and cell culture models. While the mechanisms of L-BMAA neurotoxicity have been well characterized, less is known about L-serine neuroprotection. We recently reported that L-serine and L-BMAA generate similar differential expression profiles in a human ER stress/UPR array, despite L-serine being neuroprotective and L-BMAA being linked to neurodegenerative disease. Here, we further investigate the mechanism(s) of L-serine-induced UPR dysregulation by examining key genes and proteins in the ER stress/UPR pathways. We report that L-serine selectively increased protein disulfide isomerase (PDI) protein translation, an ER chaperone involved in refolding misfolded proteins, suggesting it may be modulating the UPR to favor recovery from ER stress. This constitutes a new mechanism for L-serine-mediated neuroprotection and has implications for its use as a therapy for neurodegenerative illnesses.

  5. Brucella suis vaccine strain S2-infected immortalized caprine endometrial epithelial cell lines induce non-apoptotic ER-stress.

    Science.gov (United States)

    Wang, Xiangguo; Lin, Pengfei; Yin, Yanlong; Zhou, Jinhua; Lei, Lanjie; Zhou, Xudong; Jin, Yaping; Wang, Aihua

    2015-05-01

    Brucella, which is regarded as an intracellular pathogen responsible for a zoonotic disease called brucellosis, survives and proliferates within several types of phagocytic and non-phagocytic cells. Brucella infects not only their preferred hosts but also other domestic and wild animal species, inducing abortion and infertility. Therefore, the interaction between uterine cells and Brucella is important for understanding the pathogenesis of this disease. In this study, we describe the Brucella suis vaccine strain S2 (B.suis.S2) infection and replication in the immortalized caprine endometrial epithelial cell line hTERT-EECs and the induced cellular and molecular response modulation in vitro. We found that B.suis S2 was able to infect and replicate to high titers and inhibit the proliferation of EECs and induce non-apoptotic pathways, as determined by B.suis.S2 detection using MTT and acridine orange/ethidium bromide (AO/EB) staining and flow cytometry. We explored the evidence of non-apoptotic pathways using real-time quantitative RT-PCR and by western blot analysis. Finally, we discovered the over-expression of GRP78, ATF4, ATF6, PERK, eIF2α, CHOP, and cytochrome c (Cyt-c) but not IRE1, xbp-1, and caspase-3 in B.suis.S2 (HK)-attacked and B.suis.S2-infected cells, suggesting that the molecular mechanism of ER stress sensor activation by B.suis.S2 is basically concomitant with that by B.suis.S2 (HK) and that ER stress, especially the PERK pathway, plays an important role in the process of B.suis.S2 infecting EEC, which may, in part, explain the role of the uterus in the pathogenesis of B.suis.S2.

  6. Methyl donor deficiency in H9c2 cardiomyoblasts induces ER stress as an important part of the proteome response.

    Science.gov (United States)

    Martinez, Emilie; Deval, Christiane; Jousse, Céline; Mazur, Andrzej; Brachet, Patrick; Comte, Blandine

    2015-02-01

    Deficiency of methyl donors (MDs, folate, vitamin B12, and choline) causes increased plasma level of Hcy, a risk factor for cardiovascular diseases. Previously, we showed that maternal MD deprivation altered the cardiac proteome of rat pups. To better understand its impact on cardiac cells, we exposed rat H9c2 cardiomyoblasts to selectively a synthetic folate- or MD-deficient (FD or MDD) medium. We found that a 4-day exposure to the FD medium, unlike the MDD one, did not cause an abnormal extracellular release of Hcy relatively to similar exposure to the control complete (C) medium. Comparative analyses of the proteomes of FD, MDD, and C cells identified 7 and 6 proteins up- or downregulated by either deficiency, respectively. Most proteins were found interrelated in a single network dealing with "post-translational modification, protein folding and cell death/survival" (FD cells) or "DNA replication/recombination/repair and cell morphology/compromise" (MDD cells). Both deficiencies altered the protein and mRNA levels of the chaperones α-crystallin B, protein disulfide-isomerase A4, and prohibitin. This was concurrent with rapid induction of several key genes of the ER stress response, notably gadd153/chop, and increased expression of the E3 ubiquitin ligases, Hrd1, and MAFbx. In conclusion, the effects of folate and MD deficiencies on the cardiomyoblast proteome display some dissimilarities possibly related to different cellular production of Hcy. In both cases activation of the ER stress could occur in response to accumulation of ubiquitinated misfolded proteins. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. UBC9 regulates the stability of XBP1, a key transcription factor controlling the ER stress response.

    Science.gov (United States)

    Uemura, Aya; Taniguchi, Mai; Matsuo, Yusaku; Oku, Masaya; Wakabayashi, Sadao; Yoshida, Hiderou

    2013-01-01

    XBP1 is a key transcription factor regulating the mammalian endoplasmic reticulum (ER) stress response, which is a cytoprotective mechanism for dealing with an accumulation of unfolded proteins in the ER (ER stress). The expression of XBP1 is regulated by two different mechanisms: mRNA splicing and protein stability. When ER stress occurs, unspliced XBP1 mRNA is converted to mature mRNA, from which an active transcription factor, pXBP1(S), is translated and activates the transcription of ER-related genes to dispose of unfolded proteins. In the absence of ER stress, pXBP1(U) is translated from unspliced XBP1 mRNA and enhances the degradation of pXBP1(S). Here, we analyzed the regulatory mechanism of pXBP1(S) stability, and found that a SUMO-conjugase, UBC9, specifically bound to the leucine zipper motif of pXBP1(S) and increased the stability of pXBP1(S). Suppression of UBC9 expression by RNA interference reduced both the expression of pXBP1(S) and ER stress-induced transcription by pXBP1(S). Interestingly, overexpression of a UBC9 mutant deficient in SUMO-conjugating activity was able to increase pXBP1(S) expression as well as wild-type UBC9, indicating that UBC9 stabilizes pXBP1(S) without conjugating SUMO moieties. From these observations, we concluded that UBC9 is a novel regulator of the mammalian ER stress response.

  8. FGF21-FGFR1 Coordinates Phospholipid Homeostasis, Lipid Droplet Function, and ER Stress in Obesity.

    Science.gov (United States)

    Ye, Min; Lu, Weiqin; Wang, Xiaojie; Wang, Cong; Abbruzzese, James L; Liang, Guang; Li, Xiaokun; Luo, Yongde

    2016-12-01

    The antiobese and antidiabetic fibroblast growth factor 21 (FGF21) regulates lipid metabolism and energy homeostasis by targeting the βKlotho-FGFR1 (fibroblast growth factor receptor 1) binary complex in adipose tissue adipocytes. Because lipid droplet is the organelle responsible for storing lipid energy in adipocytes, it is the plausible target of FGF21 action. However, the impact of the FGF21-βKlotho-FGFR1 signaling pathway on the functions of the lipid droplet is not clearly understood. Using our mouse models of adipocyte-specific FGFR1 ablation and hepatic overexpression of FGF21 with diet-induced obesity established previously, we analyzed the alterations of the pathways involved in energy and substrate metabolism that is attributable to the dynamic functions of the lipid droplet. In addition to the previous reports showing that FGFR1 deficiency abrogated lipolysis, fatty acid oxidation, and energy expenditure promoted by the elevated FGF21 signal, we observed that the deficiency up-regulated the biosynthesis and remodeling of membrane phospholipids that are important for the biogenesis and expansion of the droplet, whereas the enhanced FGF21 signal constrained the biosynthesis of phospholipids. As a result, the loss of adipose FGFR1 led to a sustained droplet expansion and endoplasmic reticulum (ER) stress, whereas the enhanced FGF21 signal suppressed them in obesogenesis. These new findings reveal that the FGF21-βKlotho-FGFR1 signaling axis plays roles in maintaining phospholipid homeostasis and the dynamic functions of the lipid droplet, whereas protecting against ER stress, and suggest a potential link of phospholipid biosynthesis, lipid droplet dynamics, ER stress, and energy homeostasis in adipose tissue coordinated by this signaling axis.

  9. Varicella-Zoster Virus Infectious Cycle: ER Stress, Autophagic Flux, and Amphisome-Mediated Trafficking.

    Science.gov (United States)

    Grose, Charles; Buckingham, Erin M; Carpenter, John E; Kunkel, Jeremy P

    2016-12-10

    Varicella-zoster virus (VZV) induces abundant autophagy. Of the nine human herpesviruses, the VZV genome is the smallest (~124 kbp), lacking any known inhibitors of autophagy, such as the herpes simplex virus ICP34.5 neurovirulence gene. Therefore, this review assesses the evidence for VZV-induced cellular stress, endoplasmic-reticulum-associated degradation (ERAD), and autophagic flux during the VZV infectious cycle. Even though VZV is difficult to propagate in cell culture, the biosynthesis of the both N - and O -linked viral glycoproteins was found to be abundant. In turn, this biosynthesis provided evidence of endoplasmic reticulum (ER) stress, including a greatly enlarged ER and a greatly diminished production of cellular glycoproteins. Other signs of ER stress following VZV infection included detection of the alternatively spliced higher-molecular-weight form of XBP1 as well as CHOP. VZV infection in cultured cells leads to abundant autophagosome production, as was visualized by the detection of the microtubule-associated protein 1 light chain 3-II (LC3-II). The degree of autophagy induced by VZV infection is comparable to that induced in uninfected cells by serum starvation. The inhibition of autophagic flux by chemicals such as 3-methyladenine or ATG5 siRNA, followed by diminished virus spread and titers, has been observed. Since the latter observation pointed to the virus assembly/trafficking compartments, we purified VZ virions by ultracentrifugation and examined the virion fraction for components of the autophagy pathway. We detected LC3-II protein (an autophagy marker) as well as Rab11 protein, a component of the endosomal pathway. We also observed that the virion-containing vesicles were single-walled; thus, they are not autophagosomes. These results suggested that some VZ virions after secondary envelopment were transported to the outer cell membrane in a vesicle derived from both the autophagy and endosomal pathways, such as an amphisome. Thus, these

  10. Neutral sphingomyelinase inhibition alleviates apoptosis, but not ER stress, in liver ischemia-reperfusion injury.

    Science.gov (United States)

    Tuzcu, Hazal; Unal, Betul; Kırac, Ebru; Konuk, Esma; Ozcan, Filiz; Elpek, Gulsum O; Demir, Necdet; Aslan, Mutay

    2017-03-01

    Previous studies have revealed the activation of neutral sphingomyelinase (N-SMase)/ceramide pathway in hepatic tissue following warm liver ischemia reperfusion (IR) injury. Excessive ceramide accumulation is known to potentiate apoptotic stimuli and a link between apoptosis and endoplasmic reticulum (ER) stress has been established in hepatic IR injury. Thus, this study determined the role of selective N-SMase inhibition on ER stress and apoptotic markers in a rat model of liver IR injury. Selective N-SMase inhibitor was administered via intraperitoneal injections. Liver IR injury was created by clamping blood vessels supplying the median and left lateral hepatic lobes for 60 min, followed by 60 min reperfusion. Levels of sphingmyelin and ceramide in liver tissue were determined by an optimized multiple reactions monitoring (MRM) method using ultrafast-liquid chromatography (UFLC) coupled with tandem mass spectrometry (MS/MS). Spingomyelin levels were significantly increased in all IR groups compared with controls. Treatment with a specific N-SMase inhibitor significantly decreased all measured ceramides in IR injury. A significant increase was observed in ER stress markers C/EBP-homologous protein (CHOP) and 78 kDa glucose-regulated protein (GRP78) in IR injury, which was not significantly altered by N-SMase inhibition. Inhibition of N-SMase caused a significant reduction in phospho-NF-kB levels, hepatic TUNEL staining, cytosolic cytochrome c, and caspase-3, -8, and -9 activities which were significantly increased in IR injury. Data herein confirm the role of ceramide in increased apoptotic cell death and highlight the protective effect of N-SMase inhibition in down-regulation of apoptotic stimuli responses occurring in hepatic IR injury.

  11. Low Dose of Apelin-36 Attenuates ER Stress-Associated Apoptosis in Rats with Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Jian Qiu

    2017-10-01

    Full Text Available Cerebral ischemia/reperfusion (I/R injury-induced cellular apoptosis contributes to neuronal death in ischemic stroke, while endoplasmic reticulum stress (ERS and subsequently triggered unfolded protein response (UPR are the major mechanisms of cerebral I/R injury-induced apoptosis. A number of studies indicated that apelin-13 protects neurons from I/R injury-induced apoptosis. Apelin-36, the longest isoform of apelin, has stronger affinity to apelin receptor than apelin-13 does. However, the role of apelin-36 in ischemic stroke is less studied. In addition, preventive administration of apelin was applied in most studies, which could not precisely reflect its therapeutic potential in ischemic stroke. Here, we first reported that low dose of apelin-36, other than apelin-13, administrated after ischemic stroke significantly reduced infarct volume in rats. Moreover, apelin-36 attenuated cerebral I/R injury-induced apoptosis and caspase-3 activation. Furthermore, apelin-36 suppressed I/R injury-induced CHOP and GRP78 elevation, indicating that apelin-36 inhibited ERS/UPR activation. Our study first demonstrated that post-stroke administration of low-dose apelin-36 could attenuate cerebral I/R injury-induced infarct and apoptosis, which is associated with the inhibition of cerebral I/R injury-induced ERS/UPR activation. Our data support the therapeutic potential of apelin-36 in ischemic stroke although further investigation is needed.

  12. Bicyclol attenuates tetracycline-induced fatty liver associated with inhibition of hepatic ER stress and apoptosis in mice.

    Science.gov (United States)

    Yao, Xiao-Min; Li, Yue; Li, Hong-Wei; Cheng, Xiao-Yan; Lin, Ai-Bin; Qu, Jun-Ge

    2016-01-01

    Endoplasmic reticulum (ER) stress is known to be involved in the development of several metabolic disorders, including non-alcoholic fatty liver disease (NAFLD). Tetracycline can cause hepatic steatosis, and ER stress may be involved in tetracycline-induced fatty liver. Our previous study showed that bicyclol has been proven to protect against tetracycline-induced fatty liver in mice, and ER stress may also be involved in bicyclol's hepatoprotective effect. Therefore, this study was performed to investigate the underlying mechanisms associated with ER stress and apoptosis, by which bicyclol attenuated tetracycline-induced fatty liver in mice. Bicyclol (300 mg/kg) was given to mice by gavage 3 times. Tetracycline (200 mg/kg, intraperitoneally) was injected at 1 h after the last dose of bicyclol. At 6 h and 24 h after single dose of tetracycline injection, serum ALT, AST, TG, CHO and hepatic histopathological examinations were performed to evaluate liver injuries. Hepatic steatosis was assessed by the accumulation of hepatic TG and CHO. Moreover, hepatic apoptosis and ER stress related markers were determined by TUNEL, real-time PCR, and western blot. As a result, bicyclol significantly protected against tetracycline-induced fatty liver as evidenced by the decrease of elevated serum transaminases and hepatic triglyceride, and the attenuation of histopathological changes in mice. In addition, bicyclol remarkably alleviated hepatic apoptosis and the gene expression of caspase-3, and increased the gene expression of XIAP. The gene expressions of ER stress-related markers, including CHOP, GRP78, IRE-1α, and ATF6, which were downregulated by bicyclol pretreatment in tetracycline-injected mice. These results suggested that bicyclol protected tetracycline-induced fatty liver partly due to its ability of anti-apoptosis associated with ER stress.

  13. Baicalin protects AML-12 cells from lipotoxicity via the suppression of ER stress and TXNIP/NLRP3 inflammasome activation.

    Science.gov (United States)

    Zhang, Junli; Zhang, Haiming; Deng, Xiaoling; Zhang, Yuping; Xu, Keshu

    2017-12-25

    Baicalin (BA) is an active flavonoid compound originating from the root of Scutellaria baicalensis Georgi that has been reported to exert anti-inflammation and anti-oxidant effects in liver diseases with a long history. However, its protective and regulatory mechanisms on palmitic acid (PA) induced hepatocyte lipotoxicity remain elusive. In the present work, we investigated the cytoprotective effects of BA in AML-12 hepatocytes against lipotoxicity by inhibiting ER stress, oxidative stress and apoptosis. Our results demonstrated that ER stress was induced by 400 μM PA in AML-12 cells with elevated expression of ER stress marker IRE1α hyperphosphorylation. BA at 12.5 μM and 25 μM effectively inhibited the expression of p-IRE1α as TUDCA. Flow cytometry analysis and immunofluorescence staining revealed that PA-induced ROS and cell apoptosis were reversed by BA. Furthermore, western blotting revealed that PA-challenged expressions of TXNIP and NLRP3 were dramatically suppressed by BA and TUDCA, suggesting that BA inhibited ER stress through a TXNIP/NLRP3 pathway. Overall, our results indicate that BA alleviates PA-induced cytotoxicity in AML-12 cells via suppression of ER stress and TXNIP/NLRP3 inflammasome activation. These results provide a possible basis of the underlying mechanism and a new insight into the application for BA in the treatment of NAFLD. Copyright © 2017. Published by Elsevier B.V.

  14. The sarin-like organophosphorus agent bis(isopropyl methyl)phosphonate induces ER stress in human astrocytoma cells.

    Science.gov (United States)

    Arima, Yosuke; Shiraishi, Hiroaki; Saito, Atsushi; Yoshimoto, Kanji; Namera, Akira; Makita, Ryosuke; Murata, Kazuhiro; Imaizumi, Kazunori; Nagao, Masataka

    2016-01-01

    Organophosphorus (OP) compounds such as sarin are toxic agents that irreversibly inhibit the enzyme acetylcholinesterase. A recent study showed that OP compounds also have multiple toxicity mechanisms, and another suggested that endoplasmic reticulum (ER) dysfunction contributes to OP toxicity. However, the signaling pathway and mechanisms involved are poorly understood. We examined whether the sarin-like OP agent bis(isopropyl methyl)phosphonate (BIMP), which exhibits toxicity similar to that of sarin, induced ER stress in human astrocytoma CCF-STTG1 cells. Our results demonstrate that BIMP exposure reduced cell viability. Moreover, it induced changes in mitochondrial membrane potential and increased cleavage of caspase 3. Treatment with BIMP increased the mRNA levels of the ER stress marker genes binding immunoglobulin protein (BiP) and the transcription factor C/EBP homologous protein (CHOP). Furthermore, BIMP increased the protein expressions and phosphorylation of BiP, CHOP, and protein kinase RNA-like ER kinase and the phosphorylation of eukaryotic translation initiation factor 2. Compared to BIMP treatment alone, pretreatment with the CHOP siRNA, siCHOP, decreased BIMP-dependent CHOP expression and improved CCF-STTG1 cell viability. Our findings suggest that BIMP induced mitochondrial dysfunction and apoptotic cell death event mediated by ER stress in CCF-STTG1 cells and that treatment targeted at managing ER stress has the potential to attenuate the toxicity of OP nerve agents.

  15. HSP-4 endoplasmic reticulum (ER) stress pathway is not activated in a C. elegans model of ethanol intoxication and withdrawal.

    Science.gov (United States)

    Ient, Ben; Edwards, Richard; Mould, Richard; Hannah, Matthew; Holden-Dye, Lindy; O'Connor, Vincent

    2012-12-01

    Acute and chronic exposure of Caenorhabditis elegans to concentrations of ethanol in the range 250-350 mM elicits distinct behaviours. Previous genetic analysis highlights specific neurobiological substrates for these effects. However, ethanol may also elicit cellular stress responses which may contribute to the repertoire of ethanol-induced behaviours. Here, we have studied the effect of ethanol on an important arm of the cellular stress pathways, which emanates from the endoplasmic reticulum (ER) in response to several conditions including heat shock and chemical or genetic perturbations that lead to protein misfolding. HSP-4 is a heat shock protein and homologue of mammalian BiP. It is a pivotal upstream component of the ER stress response. Therefore, we used a C. elegans heat shock protein mutant, hsp-4, and a strain carrying a transcriptional reporter, Phsp-4::gfp, to test the role of the ER following chronic ethanol conditioning. We found no evidence for an overt ER response during acute or prolonged exposure to concentrations of ethanol that lead to defined ethanol-induced behaviours. Furthermore, whilst hsp-4 was strongly induced by tunicamycin, pre-exposure of C. elegans to low doses of tunicamycin followed by ethanol was not sufficient to induce an additive ER stress response. Behavioural analysis of an hsp-4 mutant indicated no difference compared to wild type in susceptibility to ethanol intoxication and withdrawal. There is a clear precedent for a significance of ER stress pathways particularly in clinical conditions associated with toxic or pathological effects of high doses of alcohol consumption. The concentrations of ethanol used in this C. elegans study equate to the highest blood alcohol levels measured in patients with chronic alcohol dependency. Taken together, these observations imply that the classic ER stress pathway in C. elegans is relatively refractory to induction by ethanol.

  16. Programming of Fetal Insulin Resistance in Pregnancies with Maternal Obesity by ER Stress and Inflammation

    Directory of Open Access Journals (Sweden)

    Francisco Westermeier

    2014-01-01

    Full Text Available The global epidemics of obesity during pregnancy and excessive gestational weight gain (GWG are major public health problems worldwide. Obesity and excessive GWG are related to several maternal and fetal complications, including diabetes (pregestational and gestational diabetes and intrauterine programming of insulin resistance (IR. Maternal obesity (MO and neonatal IR are associated with long-term development of obesity, diabetes mellitus, and increased global cardiovascular risk in the offspring. Multiple mechanisms of insulin signaling pathway impairment have been described in obese individuals, involving complex interactions of chronically elevated inflammatory mediators, adipokines, and the critical role of the endoplasmic reticulum (ER stress-dependent unfolded protein response (UPR. However, the underlying cellular processes linking MO and IR in the offspring have not been fully elucidated. Here, we summarize the state-of-the-art evidence supporting the possibility that adverse metabolic postnatal outcomes such as IR in the offspring of pregnancies with MO and/or excessive GWG may be related to intrauterine activation of ER stress response.

  17. Programming of Fetal Insulin Resistance in Pregnancies with Maternal Obesity by ER Stress and Inflammation

    Science.gov (United States)

    Sáez, Pablo J.; Villalobos-Labra, Roberto; Farías-Jofré, Marcelo

    2014-01-01

    The global epidemics of obesity during pregnancy and excessive gestational weight gain (GWG) are major public health problems worldwide. Obesity and excessive GWG are related to several maternal and fetal complications, including diabetes (pregestational and gestational diabetes) and intrauterine programming of insulin resistance (IR). Maternal obesity (MO) and neonatal IR are associated with long-term development of obesity, diabetes mellitus, and increased global cardiovascular risk in the offspring. Multiple mechanisms of insulin signaling pathway impairment have been described in obese individuals, involving complex interactions of chronically elevated inflammatory mediators, adipokines, and the critical role of the endoplasmic reticulum (ER) stress-dependent unfolded protein response (UPR). However, the underlying cellular processes linking MO and IR in the offspring have not been fully elucidated. Here, we summarize the state-of-the-art evidence supporting the possibility that adverse metabolic postnatal outcomes such as IR in the offspring of pregnancies with MO and/or excessive GWG may be related to intrauterine activation of ER stress response. PMID:25093191

  18. p63 mediates an apoptotic response to pharmacological and disease-related ER stress in the developing epidermis.

    Science.gov (United States)

    Pyati, Ujwal J; Gjini, Evisa; Carbonneau, Seth; Lee, Jeong-Soo; Guo, Feng; Jette, Cicely A; Kelsell, David P; Look, A Thomas

    2011-09-13

    Endoplasmic reticulum (ER) stress triggers tissue-specific responses that culminate in either cellular adaptation or apoptosis, but the genetic networks distinguishing these responses are not well understood. Here we demonstrate that ER stress induced in the developing zebrafish causes rapid apoptosis in the brain, spinal cord, tail epidermis, lens, and epiphysis. Focusing on the tail epidermis, we uncover an apoptotic response that depends on Puma, but not on p53 or Chop. puma is transcriptionally activated during this ER stress response in a p53-independent manner, and is an essential mediator of epidermal apoptosis. We demonstrate that the p63 transcription factor is upregulated to initiate this apoptotic pathway and directly activates puma transcription in response to ER stress. We also show that a mutation of human Connexin 31, which causes erythrokeratoderma variabilis, induces ER stress and p63-dependent epidermal apoptosis in the zebrafish embryo, thus implicating this pathway in the pathogenesis of inherited disease. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Crocin protects human embryonic kidney cells (HEK293) from α- and β-Zearalenol-induced ER stress and apoptosis.

    Science.gov (United States)

    Ben Salem, Intidhar; Boussabbeh, Manel; Prola, Alexandre; Guilbert, Arnaud; Bacha, Hassen; Lemaire, Christophe; Abid-Essefi, Salwa

    2016-08-01

    α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) are the major metabolites of Zearalenone (ZEN) and are known to induce many toxic effects. In the present study, we investigated the involvement of endoplasmic reticulum (ER) stress in α- and β-ZOL-mediated toxicity in human kidney cells (HEK293) and evaluated the effect of a common dietary compound Crocin (CRO), from saffron. We show that α- and β-ZOL treatment induces ER stress as evidenced by the upregulation of the 78 kDa glucose-regulated protein (GRP78) and the Growth arrest and DNA damage-inducible protein (GADD34). Activation of the ER stress response is associated with activation of the mitochondrial pathway of apoptosis. This apoptotic process is characterized by an increase in ROS generation and lipid peroxidation, a loss of mitochondrial transmembrane potential (ΔΨm) and activation of caspases. We also demonstrate that the antioxidant properties of CRO help to prevent ER stress and reduce α- and β-ZOL-induced apoptosis in HEK293 cells. Our results suggest that saffron consumption might be helpful to prevent α- and β-ZOL-induced ER stress and toxicity.

  20. Reduction of the HIV protease inhibitor-induced ER stress and inflammatory response by raltegravir in macrophages.

    Directory of Open Access Journals (Sweden)

    Xiaoxuan Zhang

    Full Text Available HIV protease inhibitor (PI, the core component of highly active antiretroviral treatment (HAART for HIV infection, has been implicated in HAART-associated cardiovascular complications. Our previous studies have demonstrated that activation of endoplasmic reticulum (ER stress is linked to HIV PI-induced inflammation and foam cell formation in macrophages. Raltegravir is a first-in-its-class HIV integrase inhibitor, the newest class of anti-HIV agents. We have recently reported that raltegravir has less hepatic toxicity and could prevent HIV PI-induced dysregulation of hepatic lipid metabolism by inhibiting ER stress. However, little information is available as to whether raltegravir would also prevent HIV PI-induced inflammatory response and foam cell formation in macrophages.In this study, we examined the effect of raltegravir on ER stress activation and lipid accumulation in cultured mouse macrophages (J774A.1, primary mouse macrophages, and human THP-1-derived macrophages, and further determined whether the combination of raltegravir with existing HIV PIs would potentially exacerbate or prevent the previously observed activation of inflammatory response and foam cell formation. The results indicated that raltegravir did not induce ER stress and inflammatory response in macrophages. Even more interestingly, HIV PI-induced ER stress, oxidative stress, inflammatory response and foam cell formation were significantly reduced by raltegravir. High performance liquid chromatography (HPLC analysis further demonstrated that raltegravir did not affect the uptake of HIV PIs in macrophages.Raltegravir could prevent HIV PI-induced inflammatory response and foam cell formation by inhibiting ER stress. These results suggest that incorporation of this HIV integrase inhibitor may reduce the cardiovascular complications associated with current HAART.

  1. Reduction of the HIV protease inhibitor-induced ER stress and inflammatory response by raltegravir in macrophages.

    Science.gov (United States)

    Zhang, Xiaoxuan; Cao, Risheng; Liu, Runping; Zhao, Renping; Huang, Yi; Gurley, Emily C; Hylemon, Phillip B; Pandak, William M; Wang, Guangji; Zhang, Luyong; Li, Xiaokun; Zhou, Huiping

    2014-01-01

    HIV protease inhibitor (PI), the core component of highly active antiretroviral treatment (HAART) for HIV infection, has been implicated in HAART-associated cardiovascular complications. Our previous studies have demonstrated that activation of endoplasmic reticulum (ER) stress is linked to HIV PI-induced inflammation and foam cell formation in macrophages. Raltegravir is a first-in-its-class HIV integrase inhibitor, the newest class of anti-HIV agents. We have recently reported that raltegravir has less hepatic toxicity and could prevent HIV PI-induced dysregulation of hepatic lipid metabolism by inhibiting ER stress. However, little information is available as to whether raltegravir would also prevent HIV PI-induced inflammatory response and foam cell formation in macrophages. In this study, we examined the effect of raltegravir on ER stress activation and lipid accumulation in cultured mouse macrophages (J774A.1), primary mouse macrophages, and human THP-1-derived macrophages, and further determined whether the combination of raltegravir with existing HIV PIs would potentially exacerbate or prevent the previously observed activation of inflammatory response and foam cell formation. The results indicated that raltegravir did not induce ER stress and inflammatory response in macrophages. Even more interestingly, HIV PI-induced ER stress, oxidative stress, inflammatory response and foam cell formation were significantly reduced by raltegravir. High performance liquid chromatography (HPLC) analysis further demonstrated that raltegravir did not affect the uptake of HIV PIs in macrophages. Raltegravir could prevent HIV PI-induced inflammatory response and foam cell formation by inhibiting ER stress. These results suggest that incorporation of this HIV integrase inhibitor may reduce the cardiovascular complications associated with current HAART.

  2. ER stress inhibitor attenuates hearing loss and hair cell death in Cdh23erl/erl mutant mice.

    Science.gov (United States)

    Hu, Juan; Li, Bo; Apisa, Luke; Yu, Heping; Entenman, Shami; Xu, Min; Stepanyan, Ruben; Guan, Bo-Jhih; Müller, Ulrich; Hatzoglou, Maria; Zheng, Qing Yin

    2016-11-24

    Hearing loss is one of the most common sensory impairments in humans. Mouse mutant models helped us to better understand the mechanisms of hearing loss. Recently, we have discovered that the erlong (erl) mutation of the cadherin23 (Cdh23) gene leads to hearing loss due to hair cell apoptosis. In this study, we aimed to reveal the molecular pathways upstream to apoptosis in hair cells to exploit more effective therapeutics than an anti-apoptosis strategy. Our results suggest that endoplasmic reticulum (ER) stress is the earliest molecular event leading to the apoptosis of hair cells and hearing loss in erl mice. We also report that the ER stress inhibitor, Salubrinal (Sal), could delay the progression of hearing loss and preserve hair cells. Our results provide evidence that therapies targeting signaling pathways in ER stress development prevent hair cell apoptosis at an early stage and lead to better outcomes than those targeting downstream factors, such as tip-link degeneration and apoptosis.

  3. Inhibitory Effects of Verrucarin A on Tunicamycin-Induced ER Stress in FaO Rat Liver Cells

    Directory of Open Access Journals (Sweden)

    Eun Young Bae

    2015-05-01

    Full Text Available Endoplasmic reticulum (ER stress is linked with development and maintenance of cancer, and serves as a therapeutic target for treatment of cancer. Verrucarin A, isolated from the broth of Fusarium sp. F060190, showed potential inhibitory activity on tunicamycin-induced ER stress in FaO rat liver cells. In addition, the compound decreased tunicamycin-induced GRP78 promoter activity in a dose dependent manner without inducing significant inhibition of luciferase activity and cell growth for 6 and 12 h. Moreover, the compound decreased the expression of GRP78, CHOP, XBP-1, and suppressed XBP-1, and reduced phosphorylation of IRE1α in FaO rat liver cells. This evidence suggests for the first time that verrucarin A inhibited tunicamycin-induced ER stress in FaO rat liver cells.

  4. Dietary Fish Oil Inhibits Pro-Inflammatory and ER Stress Signalling Pathways in the Liver of Sows during Lactation.

    Directory of Open Access Journals (Sweden)

    Denise K Gessner

    Full Text Available Lactating sows have been shown to develop typical signs of an inflammatory condition in the liver during the transition from pregnancy to lactation. Hepatic inflammation is considered critical due to the induction of an acute phase response and the activation of stress signaling pathways like the endoplasmic reticulum (ER stress-induced unfolded protein response (UPR, both of which impair animal's health and performance. Whether ER stress-induced UPR is also activated in the liver of lactating sows and whether dietary fish oil as a source of anti-inflammatory effects n-3 PUFA is able to attenuate hepatic inflammation and ER stress-induced UPR in the liver of sows is currently unknown. Based on this, two experiments with lactating sows were performed. The first experiment revealed that ER stress-induced UPR occurs also in the liver of sows during lactation. This was evident from the up-regulation of a set of genes regulated by the UPR and numerically increased phosphorylation of the ER stress-transducer PERK and PERK-mediated phosphorylation of eIF2α and IκB. The second experiment showed that fish oil inhibits ER stress-induced UPR in the liver of lactating sows. This was demonstrated by decreased mRNA levels of a number of UPR-regulated genes and reduced phosphorylation of PERK and PERK-mediated phosphorylation of eIF2α and IκB in the liver of the fish oil group. The mRNA levels of various nuclear factor-κB-regulated genes encoding inflammatory mediators and acute phase proteins in the liver of lactating sows were also reduced in the fish oil group. In line with this, the plasma levels of acute phase proteins were reduced in the fish oil group, although differences to the control group were not significant. In conclusion, ER stress-induced UPR is present in the liver of lactating sows and fish oil is able to inhibit inflammatory signaling pathways and ER stress-induced UPR in the liver.

  5. Dietary Fish Oil Inhibits Pro-Inflammatory and ER Stress Signalling Pathways in the Liver of Sows during Lactation

    Science.gov (United States)

    Gessner, Denise K.; Gröne, Birthe; Couturier, Aline; Rosenbaum, Susann; Hillen, Sonja; Becker, Sabrina; Erhardt, Georg; Reiner, Gerald; Ringseis, Robert; Eder, Klaus

    2015-01-01

    Lactating sows have been shown to develop typical signs of an inflammatory condition in the liver during the transition from pregnancy to lactation. Hepatic inflammation is considered critical due to the induction of an acute phase response and the activation of stress signaling pathways like the endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR), both of which impair animal´s health and performance. Whether ER stress-induced UPR is also activated in the liver of lactating sows and whether dietary fish oil as a source of anti-inflammatory effects n-3 PUFA is able to attenuate hepatic inflammation and ER stress-induced UPR in the liver of sows is currently unknown. Based on this, two experiments with lactating sows were performed. The first experiment revealed that ER stress-induced UPR occurs also in the liver of sows during lactation. This was evident from the up-regulation of a set of genes regulated by the UPR and numerically increased phosphorylation of the ER stress-transducer PERK and PERK-mediated phosphorylation of eIF2α and IκB. The second experiment showed that fish oil inhibits ER stress-induced UPR in the liver of lactating sows. This was demonstrated by decreased mRNA levels of a number of UPR-regulated genes and reduced phosphorylation of PERK and PERK-mediated phosphorylation of eIF2α and IκB in the liver of the fish oil group. The mRNA levels of various nuclear factor-κB-regulated genes encoding inflammatory mediators and acute phase proteins in the liver of lactating sows were also reduced in the fish oil group. In line with this, the plasma levels of acute phase proteins were reduced in the fish oil group, although differences to the control group were not significant. In conclusion, ER stress-induced UPR is present in the liver of lactating sows and fish oil is able to inhibit inflammatory signaling pathways and ER stress-induced UPR in the liver. PMID:26351857

  6. Morbillivirus glycoprotein expression induces ER stress, alters Ca2+ homeostasis and results in the release of vasostatin.

    Directory of Open Access Journals (Sweden)

    Jean-Marc Brunner

    Full Text Available Although the pathology of Morbillivirus in the central nervous system (CNS is well described, the molecular basis of neurodegenerative events still remains poorly understood. As a model to explore Morbillivirus-mediated CNS dysfunctions, we used canine distemper virus (CDV that we inoculated into two different cell systems: a monkey cell line (Vero and rat primary hippocampal neurons. Importantly, the recombinant CDV used in these studies not only efficiently infects both cell types but recapitulates the uncommon, non-cytolytic cell-to-cell spread mediated by virulent CDVs in brain of dogs. Here, we demonstrated that both CDV surface glycoproteins (F and H markedly accumulated in the endoplasmic reticulum (ER. This accumulation triggered an ER stress, characterized by increased expression of the ER resident chaperon calnexin and the proapoptotic transcription factor CHOP/GADD 153. The expression of calreticulin (CRT, another ER resident chaperon critically involved in the response to misfolded proteins and in Ca(2+ homeostasis, was also upregulated. Transient expression of recombinant CDV F and H surface glycoproteins in Vero cells and primary hippocampal neurons further confirmed a correlation between their accumulation in the ER, CRT upregulation, ER stress and disruption of ER Ca(2+ homeostasis. Furthermore, CDV infection induced CRT fragmentation with re-localisation of a CRT amino-terminal fragment, also known as vasostatin, on the surface of infected and neighbouring non-infected cells. Altogether, these results suggest that ER stress, CRT fragmentation and re-localization on the cell surface may contribute to cytotoxic effects and ensuing cell dysfunctions triggered by Morbillivirus, a mechanism that might potentially be relevant for other neurotropic viruses.

  7. Spliced leader RNA silencing (SLS - a programmed cell death pathway in Trypanosoma brucei that is induced upon ER stress

    Directory of Open Access Journals (Sweden)

    Michaeli Shulamit

    2012-05-01

    Full Text Available Abstract Trypanosoma brucei is the causative agent of African sleeping sickness. The parasite cycles between its insect (procyclic form and mammalian hosts (bloodstream form. Trypanosomes lack conventional transcription regulation, and their genes are transcribed in polycistronic units that are processed by trans-splicing and polyadenylation. In trans-splicing, which is essential for processing of each mRNA, an exon, the spliced leader (SL is added to all mRNAs from a small RNA, the SL RNA. Trypanosomes lack the machinery for the unfolded protein response (UPR, which in other eukaryotes is induced under endoplasmic reticulum (ER stress. Trypanosomes respond to such stress by changing the stability of mRNAs, which are essential for coping with the stress. However, under severe ER stress that is induced by blocking translocation of proteins to the ER, treatment of cells with chemicals that induce misfolding in the ER, or extreme pH, trypanosomes elicit the spliced leader silencing (SLS pathway. In SLS, the transcription of the SL RNA gene is extinguished, and tSNAP42, a specific SL RNA transcription factor, fails to bind to its cognate promoter. SLS leads to complete shut-off of trans-splicing. In this review, I discuss the UPR in mammals and compare it to the ER stress response in T. brucei leading to SLS. I summarize the evidence supporting the notion that SLS is a programmed cell death (PCD pathway that is utilized by the parasites to substitute for the apoptosis observed in higher eukaryotes under prolonged ER stress. I present the hypothesis that SLS evolved to expedite the death process, and rapidly remove from the population unfit parasites that, by elimination via SLS, cause minimal damage to the parasite population.

  8. ER Stress Inhibits Liver Fatty Acid Oxidation while Unmitigated Stress Leads to Anorexia-Induced Lipolysis and Both Liver and Kidney Steatosis

    DEFF Research Database (Denmark)

    DeZwaan-McCabe, Diane; Sheldon, Ryan D; Gorecki, Michelle C

    2017-01-01

    The unfolded protein response (UPR), induced by endoplasmic reticulum (ER) stress, regulates the expression of factors that restore protein folding homeostasis. However, in the liver and kidney, ER stress also leads to lipid accumulation, accompanied at least in the liver by transcriptional...... suppression of metabolic genes. The mechanisms of this accumulation, including which pathways contribute to the phenotype in each organ, are unclear. We combined gene expression profiling, biochemical assays, and untargeted lipidomics to understand the basis of stress-dependent lipid accumulation, taking...... advantage of enhanced hepatic and renal steatosis in mice lacking the ER stress sensor ATF6α. We found that impaired fatty acid oxidation contributed to the early development of steatosis in the liver but not the kidney, while anorexia-induced lipolysis promoted late triglyceride and free fatty acid...

  9. Spontaneous nonalcoholic fatty liver disease and ER stress in Sidt2 deficiency mice

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jialin [Department of Endocrinology and Genetic Metabolism, Yijishan Hospital of Wannan Medical College, Wuhu, 241002 (China); Anhui Province Key Laboratory of Biological Macro-molecules Research, Wannan Medical College, Wuhu, 241001 (China); Zhang, Yao [Anhui Province Key Laboratory of Biological Macro-molecules Research, Wannan Medical College, Wuhu, 241001 (China); Department of Biochemistry and Molecular Biology, Wannan Medical Collage, Wuhu, 241002 (China); Yu, Cui [Department of Endocrinology and Genetic Metabolism, Yijishan Hospital of Wannan Medical College, Wuhu, 241002 (China); Anhui Province Key Laboratory of Biological Macro-molecules Research, Wannan Medical College, Wuhu, 241001 (China); Tan, Fengbiao [Anhui Province Key Laboratory of Biological Macro-molecules Research, Wannan Medical College, Wuhu, 241001 (China); Department of Biochemistry and Molecular Biology, Wannan Medical Collage, Wuhu, 241002 (China); Wang, Lizhuo, E-mail: 19277924@qq.com [Anhui Province Key Laboratory of Biological Macro-molecules Research, Wannan Medical College, Wuhu, 241001 (China); Department of Biochemistry and Molecular Biology, Wannan Medical Collage, Wuhu, 241002 (China)

    2016-08-05

    Sidt2 is a newly discovered lysosomal membrane protein that is closely related to glucose metabolism. In the present study, we found that Sidt2 is also closely related to lipid metabolism. Gradual increases in serum triglyceride (TG) and free fatty acid, as well as elevated aspartate transaminase and alanine transaminase levels were observed in Sidt2{sup −/−} mice fed a normal diet from the age of 3 months, suggesting the presence of lipid metabolism disorders and impaired liver function in these mice. In the liver slices of 6-month-old Sidt2{sup −/−} mice, there were obvious fat degeneration and inflammatory changes. Almost all of the liver cells demonstrated different levels of lipid droplet accumulation and cell swelling, and some of the cells demonstrated balloon-like changes. Infiltration of inflammatory cells was observed in the portal area and hepatic lobule. Electron microscopy showed that macrophages tended to be attached to the endothelial cells, and a large number of lipid droplets were present in the liver cells. Oil red O staining showed that there were significantly increased number of deep straining particles in the liver cells of Sidt2{sup −/−} mice, and the TG content in liver tissue was also significantly increased. Detection of key genes and proteins related to fat synthesis showed that mRNA and protein levels of the SREBP1c in the liver of Sidt2{sup −/−} mice were significantly elevated, and the downstream genes acetyl-CoA carboxylase, fatty acid synthase, and mitochondrial glycerol 3-phosphate acyltransferase were significantly upregulated. In addition, there was severe endoplasmic reticulum stress (ERS) in the liver of Sidt2{sup −/−} mice, which had significantly increased levels of markers specific for unfolded protein response activation, Grp78 and CHOP, as well as significant elevation of downstream p-PERK, p-eIF2a, p-IRE1a, along with ER damage. These results suggest that Sidt2{sup −/−} mice had spontaneous

  10. Neuroprotective Effects of Dexmedetomidine against Thapsigargin-induced ER-stress via Activity of α2-adrenoceptors and Imidazoline Receptors

    Directory of Open Access Journals (Sweden)

    Manami Inagaki

    2016-07-01

    Full Text Available Dexmedetomidine is a potent and highly selective α2-adrenoceptor agonist with sedative, analgesic, and sympatholytic properties, though it also exhibits some affinity for imidazoline binding sites. In addition to its sedative effects, dexmedetomidine exerts neuroprotective effects under ischemic conditions. Invasive incidents such as ischemia or hypoxia induce dysfunctions in energy production or depletion of ATP as well as accumulation and aggregation of abnormal proteins in the endoplasmic reticulum (ER, leading to an ER-stress response. In the present study, we examined whether dexmedetomidine exerts inhibitory effects on apoptosis mediated by thapsigargin-induced ER-stress in SH-SY5Y cells, and proposed a possible underlying mechanism for its neuroprotective effects. We used thapsigargin (TG to generate an ER-stress response in SH-SY5Y cells. SH-SY5Y cells were pretreated with Dex (1–1000 nM or receptor antagonists (atipamezole, efaroxan, BU99006, and 2’,5’-dideoxyadenosine for 1 hour before co-treatment with 1 mM TG for 20 hours. Co-incubation with dexmedetomidine suppressed thapsigargin-induced increases in cytosolic Ca2+, caspase-4 and -3 activity, eIF2α phosphorylation, and expression of ER-stress biomarkers. Dexmedetomidine treatment also decreased cAMP levels. In the presence of atipamezole or efaroxan, but not BU99006, inhibition of eIF2α phosphorylation and CHOP expression significantly increased following treatment with dexmedetomidine in thapsigargin-treated cells. However, pretreatment with BU99006 enhanced the increase in mitochondrial membrane potential associated with dexmedetomidine treatment. The results of the present study demonstrate that dexmedetomidine at clinically relevant concentrations suppresses ER-stress-induced apoptosis in SH-SY5Y cells. Some neuroprotective effects of dexmedetomidine may be mediated by α2-adrenoceptor and I1- and I2-receptors.

  11. Cocaine-mediated microglial activation involves the ER stress-autophagy axis

    Science.gov (United States)

    Guo, Ming-Lei; Liao, Ke; Periyasamy, Palsamy; Yang, Lu; Cai, Yu; Callen, Shannon E; Buch, Shilpa

    2015-01-01

    Cocaine abuse leads to neuroinflammation, which, in turn, contributes to the pathogenesis of neurodegeneration associated with advanced HIV-1 infection. Autophagy plays important roles in both innate and adaptive immune responses. However, the possible functional link between cocaine and autophagy has not been explored before. Herein, we demonstrate that cocaine exposure induced autophagy in both BV-2 and primary rat microglial cells as demonstrated by a dose- and time-dependent induction of autophagy-signature proteins such as BECN1/Beclin 1, ATG5, and MAP1LC3B. These findings were validated wherein cocaine treatment of BV-2 cells resulted in increased formation of puncta in cells expressing either endogenous MAP1LC3B or overexpressing GFP-MAP1LC3B. Specificity of cocaine-induced autophagy was confirmed by treating cells with inhibitors of autophagy (3-MA and wortmannin). Intriguingly, cocaine-mediated induction of autophagy involved upstream activation of 2 ER stress pathways (EIF2AK3- and ERN1-dependent), as evidenced by the ability of the ER stress inhibitor salubrinal to ameliorate cocaine-induced autophagy. In vivo validation of these findings demonstrated increased expression of BECN1, ATG5, and MAP1LC3B-II proteins in cocaine-treated mouse brains compared to untreated animals. Increased autophagy contributes to cocaine-mediated activation of microglia since pretreatment of cells with wortmannin resulted in decreased expression and release of inflammatory factors (TNF, IL1B, IL6, and CCL2) in microglial cells. Taken together, our findings suggest that cocaine exposure results in induction of autophagy that is closely linked with neuroinflammation. Targeting autophagic proteins could thus be considered as a therapeutic strategy for the treatment of cocaine-related neuroinflammation diseases. PMID:26043790

  12. The duration of gastrin treatment affects global gene expression and molecular responses involved in ER stress and anti-apoptosis.

    Science.gov (United States)

    Selvik, Linn-Karina M; Fjeldbo, Christina S; Flatberg, Arnar; Steigedal, Tonje S; Misund, Kristine; Anderssen, Endre; Doseth, Berit; Langaas, Mette; Tripathi, Sushil; Beisvag, Vidar; Lægreid, Astrid; Thommesen, Liv; Bruland, Torunn

    2013-06-28

    How cells decipher the duration of an external signal into different transcriptional outcomes is poorly understood. The hormone gastrin can promote a variety of cellular responses including proliferation, differentiation, migration and anti-apoptosis. While gastrin in normal concentrations has important physiological functions in the gastrointestine, prolonged high levels of gastrin (hypergastrinemia) is related to pathophysiological processes. We have used genome-wide microarray time series analysis and molecular studies to identify genes that are affected by the duration of gastrin treatment in adenocarcinoma cells. Among 403 genes differentially regulated in transiently (gastrin removed after 1 h) versus sustained (gastrin present for 14 h) treated cells, 259 genes upregulated by sustained gastrin treatment compared to untreated controls were expressed at lower levels in the transient mode. The difference was subtle for early genes like Junb and c-Fos, but substantial for delayed and late genes. Inhibition of protein synthesis by cycloheximide was used to distinguish between primary and secondary gastrin regulated genes. The majority of gastrin upregulated genes lower expressed in transiently treated cells were primary genes induced independently of de novo protein synthesis. This indicates that the duration effect of gastrin treatment is mainly mediated via post-translational signalling events, while a smaller fraction of the differentially expressed genes are regulated downstream of primary transcriptional events. Indeed, sustained gastrin treatment specifically induced prolonged ERK1/2 activation and elevated levels of the AP-1 subunit protein JUNB. Enrichment analyses of the differentially expressed genes suggested that endoplasmic reticulum (ER) stress and survival is affected by the duration of gastrin treatment. Sustained treatment exerted an anti-apoptotic effect on serum starvation-induced apoptosis via a PKC-dependent mechanism. In accordance with this

  13. Chemical Chaperones Reduce ER Stress and Restore Glucose Homeostasis in a Mouse Model of Type 2 Diabetes

    Science.gov (United States)

    Özcan, Umut; Yilmaz, Erkan; Özcan, Lale; Furuhashi, Masato; Vaillancourt, Eric; Smith, Ross O.; Görgün, Cem Z.; Hotamisligil, Gökhan S.

    2006-08-01

    Endoplasmic reticulum (ER) stress is a key link between obesity, insulin resistance, and type 2 diabetes. Here, we provide evidence that this mechanistic link can be exploited for therapeutic purposes with orally active chemical chaperones. 4-Phenyl butyric acid and taurine-conjugated ursodeoxycholic acid alleviated ER stress in cells and whole animals. Treatment of obese and diabetic mice with these compounds resulted in normalization of hyperglycemia, restoration of systemic insulin sensitivity, resolution of fatty liver disease, and enhancement of insulin action in liver, muscle, and adipose tissues. Our results demonstrate that chemical chaperones enhance the adaptive capacity of the ER and act as potent antidiabetic modalities with potential application in the treatment of type 2 diabetes.

  14. Expression of bioactive anti-CD20 antibody fragments and induction of ER stress response in Arabidopsis seeds.

    Science.gov (United States)

    Wang, Dezhong; Ma, Jisheng; Sun, Difei; Li, Haiyan; Jiang, Chao; Li, Xiaokun

    2015-08-01

    Seed-based expression system is an attractive platform for the production of recombinant proteins in molecular farming. Despite the many advantages of molecular farming, little is known about the effect of the different subcellular accumulation of recombinant proteins on the endoplasmic reticulum (ER) quality control system in host plants. In this study, we analyzed the expression of anti-CD20 antibody fragments in seeds of Arabidopsis thaliana (ecotype Columbia) and corresponding glycosylation mutants, and evaluated the influence of three different signal sequences on the expression levels of scFv-Fc of C2B8. The highest protein accumulation level, with a maximum of 6.12 % total soluble proteins, was observed upon fusing proteins to the signal peptide of Arabidopsis seed storage albumin 2. The ER stress responses in developing seeds at 13 days post-anthesis were also compared across different transgenic lines under normal and heat shock conditions. Based on the gene expression profiles of ER stress transducers, our results suggest that accumulation of antibody fragments in the ER exerts more stress on ER homeostasis. In addition, quantitative PCR results also implicate enhanced activation of ER-associated degradation in transgenic lines. Last but not the least, we also demonstrate the anti-tumor potency of plant-derived proteins by showing the anti-tumor activity of purified scFv-Fc proteins against Daudi cells. Together, our data implies that better understanding of the interaction between exogenous protein production and the cellular quality control system of the host plant is necessary for the development of an optimal expression strategy that will be especially beneficial to commercial protein manufacturing.

  15. ER Stress Inhibits Liver Fatty Acid Oxidation while Unmitigated Stress Leads to Anorexia-Induced Lipolysis and Both Liver and Kidney Steatosis.

    Science.gov (United States)

    DeZwaan-McCabe, Diane; Sheldon, Ryan D; Gorecki, Michelle C; Guo, Deng-Fu; Gansemer, Erica R; Kaufman, Randal J; Rahmouni, Kamal; Gillum, Matthew P; Taylor, Eric B; Teesch, Lynn M; Rutkowski, D Thomas

    2017-05-30

    The unfolded protein response (UPR), induced by endoplasmic reticulum (ER) stress, regulates the expression of factors that restore protein folding homeostasis. However, in the liver and kidney, ER stress also leads to lipid accumulation, accompanied at least in the liver by transcriptional suppression of metabolic genes. The mechanisms of this accumulation, including which pathways contribute to the phenotype in each organ, are unclear. We combined gene expression profiling, biochemical assays, and untargeted lipidomics to understand the basis of stress-dependent lipid accumulation, taking advantage of enhanced hepatic and renal steatosis in mice lacking the ER stress sensor ATF6α. We found that impaired fatty acid oxidation contributed to the early development of steatosis in the liver but not the kidney, while anorexia-induced lipolysis promoted late triglyceride and free fatty acid accumulation in both organs. These findings provide evidence for both direct and indirect regulation of peripheral metabolism by ER stress. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Signaling dynamics of palmitate-induced ER stress responses mediated by ATF4 in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Cho Hyunju

    2013-01-01

    Full Text Available Abstract Background Palmitic acid, the most common saturated free fatty acid, has been implicated in ER (endoplasmic reticulum stress-mediated apoptosis. This lipoapotosis is dependent, in part, on the upregulation of the activating transcription factor-4 (ATF4. To better understand the mechanisms by which palmitate upregulates the expression level of ATF4, we integrated literature information on palmitate-induced ER stress signaling into a discrete dynamic model. The model provides an in silico framework that enables simulations and predictions. The model predictions were confirmed through further experiments in human hepatocellular carcinoma (HepG2 cells and the results were used to update the model and our current understanding of the signaling induced by palmitate. Results The three key things from the in silico simulation and experimental results are: 1 palmitate induces different signaling pathways (PKR (double-stranded RNA-activated protein kinase, PERK (PKR-like ER kinase, PKA (cyclic AMP (cAMP-dependent protein kinase A in a time dependent-manner, 2 both ATF4 and CREB1 (cAMP-responsive element-binding protein 1 interact with the Atf4 promoter to contribute to a prolonged accumulation of ATF4, and 3 CREB1 is involved in ER-stress induced apoptosis upon palmitate treatment, by regulating ATF4 expression and possibly Ca2+ dependent-CaM (calmodulin signaling pathway. Conclusion The in silico model helped to delineate the essential signaling pathways in palmitate-mediated apoptosis.

  17. Structure-activity relationship of piperine and its synthetic amide analogs for therapeutic potential to prevent experimentally induced ER stress in vitro.

    Science.gov (United States)

    Hammad, Ayat S; Ravindran, Sreenithya; Khalil, Ashraf; Munusamy, Shankar

    2017-05-01

    Endoplasmic reticulum (ER) is the key organelle involved in protein folding and maturation. Emerging studies implicate the role of ER stress in the development of chronic kidney disease. Thus, there is an urgent need for compounds that could ameliorate ER stress and prevent CKD. Piperine and its analogs have been reported to exhibit multiple pharmacological activities; however, their efficacy against ER stress in kidney cells has not been studied yet. Hence, the goal of this study was to synthesize amide-substituted piperine analogs and screen them for pharmacological activity to relieve ER stress using an in vitro model of tunicamycin-induced ER stress using normal rat kidney (NRK-52E) cells. Five amide-substituted piperine analogs were synthesized and their chemical structures were elucidated by pertinent spectroscopic techniques. An in vitro model of ER stress was developed using tunicamycin, and the compounds of interest were screened for their effect on cell viability, and the expression of ER chaperone GRP78, the pro-apoptotic ER stress marker CHOP, and apoptotic caspases 3 and 12 (via western blotting). Our findings indicate that exposure to tunicamycin (0.5 μg/mL) for 2 h induces the expression of GRP78 and CHOP, and apoptotic markers (caspase-3 and caspase-12) and causes a significant reduction in renal cell viability. Pre-treatment of cells with piperine and its cyclohexylamino analog decreased the tunicamycin-induced upregulation of GRP78 and CHOP and cell death. Taken together, our findings demonstrate that piperine and its analogs differentially regulate ER stress, and thus represent potential therapeutic agents to treat ER stress-related renal disorders. Graphical Abstract Piperine (PIP) reduces the expression of ER stress markers (GRP78 and CHOP) induced by pathologic stimuli and consequently decreases the activation of apoptotic caspase-12 and caspase-3; all of which contributes to its chemical chaperone and cytoprotective properties to protect

  18. Effects of Fat and Sugar, Either Consumed or Infused toward the Brain, on Hypothalamic ER Stress Markers

    Directory of Open Access Journals (Sweden)

    Evita Belegri

    2017-05-01

    Full Text Available Protein-folding stress at the Endoplasmic Reticulum (ER occurs in the hypothalamus during diet-induced obesity (DIO and is linked to metabolic disease development. ER stress is buffered by the activation of the unfolded protein response (UPR, a controlled network of pathways inducing a set of genes that recovers ER function. However, it is unclear whether hypothalamic ER stress during DIO results from obesity related changes or from direct nutrient effects in the brain. We here investigated mRNA expression of UPR markers in the hypothalamus of rats that were exposed to a free choice high-fat high-sugar (fcHFHS diet for 1 week and then overnight fed ad libitum, or fasted, or fat/sugar deprived (i.e., switched from obesogenic diet to chow. In addition, we determined the direct effects of fat/sugar on mRNA expression of hypothalamus UPR markers by intracarotic infusions of intralipids and/or glucose in chow-fed rats that were fasted overnight. Short term (1 week exposure to fcHFHS diet increased adiposity compared to chow-feeding. Short term exposure to a fcHFHS diet, followed by mild food restriction overnight, induced hypothalamic ER stress in rats as characterized by an increase in spliced to unspliced X-box binding protein 1 mRNA ratio in hypothalamus of fcHFHS fed rats compared to chow fed rats. Moreover, infused lipids toward the brain of overnight fasted rats, were able to induce a similar response. Non-restricted ad libitum fcHFHS-diet fed or totally fasted rats did not show altered ratios. We also observed a clear increase in hypothalamic activating transcription factor 4 mRNA in rats on the fcHFHS diet while being ad libitum fed or when infused with intralipid via the carotic artery compared to vehicle infusions. However, we did not observe induction of downstream targets implying that this effect is a more general stress response and not related to ER stress. Overall, we conclude that the hypothalamic stress response might be a sensitive

  19. Effect of Saturated Stearic Acid on MAP Kinase and ER Stress Signaling Pathways during Apoptosis Induction in Human Pancreatic β-Cells Is Inhibited by Unsaturated Oleic Acid

    Directory of Open Access Journals (Sweden)

    Jan Šrámek

    2017-11-01

    Full Text Available It has been shown that saturated fatty acids (FAs have a detrimental effect on pancreatic β-cells function and survival, leading to apoptosis, whereas unsaturated FAs are well tolerated and are even capable of inhibiting the pro-apoptotic effect of saturated FAs. Molecular mechanisms of apoptosis induction and regulation by FAs in β-cells remain unclear; however, mitogen-activated protein (MAP kinase and endoplasmic reticulum (ER stress signaling pathways may be involved. In this study, we tested how unsaturated oleic acid (OA affects the effect of saturated stearic acid (SA on the p38 mitogen-activated protein kinase (MAPK and extracellular signal-regulated kinase (ERK pathways as well as the ER stress signaling pathways during apoptosis induction in the human pancreatic β-cells NES2Y. We demonstrated that OA is able to inhibit all effects of SA. OA alone has only minimal or no effects on tested signaling in NES2Y cells. The point of OA inhibitory intervention in SA-induced apoptotic signaling thus seems to be located upstream of the discussed signaling pathways.

  20. ER Stress Inhibits Liver Fatty Acid Oxidation while Unmitigated Stress Leads to Anorexia-Induced Lipolysis and Both Liver and Kidney Steatosis

    DEFF Research Database (Denmark)

    DeZwaan-McCabe, Diane; Sheldon, Ryan D; Gorecki, Michelle C

    2017-01-01

    advantage of enhanced hepatic and renal steatosis in mice lacking the ER stress sensor ATF6α. We found that impaired fatty acid oxidation contributed to the early development of steatosis in the liver but not the kidney, while anorexia-induced lipolysis promoted late triglyceride and free fatty acid...

  1. The NAC domain-containing protein, GmNAC6, is a downstream component of the ER stress- and osmotic stress-induced NRP-mediated cell-death signaling pathway

    OpenAIRE

    Pinheiro Guilherme L; Rosado Gustavo L; Reis Marco TB; Reis Pedro AB; Faria Jerusa AQA; Mendes Giselle C; Fontes Elizabeth PB

    2011-01-01

    Abstract Background The endoplasmic reticulum (ER) is a major signaling organelle, which integrates a variety of responses against physiological stresses. In plants, one such stress-integrating response is the N-rich protein (NRP)-mediated cell death signaling pathway, which is synergistically activated by combined ER stress and osmotic stress signals. Despite the potential of this integrated signaling to protect plant cells against different stress conditions, mechanistic knowledge of the pa...

  2. Male breast carcinoma: correlation of ER, PR, Ki-67, Her2-Neu, and p53 with treatment and survival, a study of 65 cases.

    Science.gov (United States)

    Wang-Rodriguez, Jessica; Cross, Keith; Gallagher, Scott; Djahanban, Marcia; Armstrong, Janet M; Wiedner, Noel; Shapiro, David H

    2002-08-01

    Male breast cancer is rare, and experience of it in any single institution is limited. Our current understanding regarding its biology, natural history, and treatment strategies has been extrapolated from its female counterpart. The aim of this study is to evaluate the expression patterns of estrogen receptor (ER), progesterone receptor (PR), MiB1 (Ki67), Her-2/neu (c-erbB2), and p53 and to correlate them with the prognosis, presentation, staging, management, and survival/outcome in male breast carcinoma identified through the Veterans Administration nationwide cancer registry. Sixty-five cases of male breast cancer were reviewed for classification. Tumor blocks were requested from each institution for immunohistochemical staining and evaluation of ER, PR, p53, Her2-neu, and MiB1. Seventeen age- and disease-matched male veteran patients with breast gynecomastia were used as controls. Traditional prognostic data were collected for comparison with female breast cancers (i.e., age, lymph node status, clinical staging, tumor size, histological grade, and disease-free and overall survival). Male breast carcinoma had worse disease-free survival than controls (P =.03). The clinical stage regardless of tumor size or lymph node metastasis was the single most significant prognostic factor (P <.0001). ER-positive patients appeared to have a better survival than did ER-negative patients (P =.03, univariate; P not significant in multivariate) and did not benefit from treatment with tamoxifen (P =.0027, univariate; P =.42, multivariate). MiB1 and PR expressions did not correlate with treatment or survival, and p53 was associated with shorter disease free survival (P =.07, univariate; P =.047, multivariate). Stage for stage, Her2-neu was associated with shorter disease-free survival (P <.0001) and correlated with positive lymph nodes (P =.08). Surgery alone versus surgery with adjuvant treatments (chemotherapy, radiotherapy, tamoxifen, or combination) did not show any survival

  3. Valsartan reduces AT1-AA-induced apoptosis through suppression oxidative stress mediated ER stress in endothelial progenitor cells.

    Science.gov (United States)

    Wang, Z-C; Qi, J; Liu, L-M; Li, J; Xu, H-Y; Liang, B; Li, B

    2017-03-01

    Valsartan has been reported to have the function of treating hypertension and improving the prognosis of patients. Many studies indicated that valsartan can also increase angiotensin II, andosterone and plasma renin activity (PRA). Autoantibodies against the angiotensin II type 1 receptor (AT1-AA) have been showed to increase reactive oxygen species (ROS) and calcium (Ca2+) and result in apoptosis in vascular smooth muscle cells. In this study, we attempted to explore the effect of valsartan on AT1-AA-induced apoptosis in endothelial progenitor cells. Endothelial progenitor cells (EPCs) were cultured. The cytotoxicity was determined by MTT assay. EPCs apoptosis was determined by DAPI staining and flow cytometry. Reactive oxygen species, intracellular calcium concentration and calpain activity were measured using Fluostar Omega Spectrofluorimeter. The expression of p-ERK, p-eIF-2a, CHOP, Bcl-2 and caspase-3 were detected by Western blot. MTT assays showed valsartan significantly inhibited AT1-AA- induced decline of the viability of EPCs. DAPI staining and flow cytometry results indicated valsartan inhibited AT1-AA-induced decline of the viability of EPCs via inhibiting AT1-AA-induced apoptosis. Furthermore, the increasing of reactive oxygen species, intracellular calcium and calpain activity induced by AT1-AA in EPCs were also recovered after pre-treated with valsartan. Meanwhile, the upregulation of p-ERK, p-eIF-2a and CHOP, downregulation of Bcl-2, and activation of Caspase-3 caused by AT1-AA were reversed after pre-incubated with valsartan. Valsartan could inhibit AT1-AA-induced apoptosis through inhibiting oxidative stress mediated ER stress in EPCs.

  4. ERO1α-dependent endoplasmic reticulum-mitochondrial calcium flux contributes to ER stress and mitochondrial permeabilization by procaspase-activating compound-1 (PAC-1).

    Science.gov (United States)

    Seervi, M; Sobhan, P K; Joseph, J; Ann Mathew, K; Santhoshkumar, T R

    2013-12-19

    Procaspase-activating compound-1 (PAC-1) is the first direct caspase-activating compound discovered; using an in vitro cell-free system of caspase activation. Subsequently, this compound was shown to induce apoptosis in a variety of cancer cells with promising in vivo antitumor activity in canine lymphoma model. Recently, we have reported its ability to kill drug-resistant, Bcl-2/Bcl-xL overexpressing and Bax/Bak-deficient cells despite the essential requirement of mitochondrial cytochrome c (cyt. c) release for caspase activation, indicating that the key molecular targets of PAC-1 in cancer cells are yet to be identified. Here, we have identified Ero1α-dependent endoplasmic reticulum (ER) calcium leakage to mitochondria through mitochondria-associated ER membranes (MAM) and ER luminal hyper-oxidation as the critical events of PAC-1-mediated cell death. PAC-1 treatment upregulated Ero1α in multiple cell lines, whereas silencing of Ero1α significantly inhibited calcium release from ER and cell death. Loss of ER calcium and hyper-oxidation of ER lumen by Ero1α collectively triggered ER stress. Upregulation of GRP78 and splicing of X-box-binding protein 1 (XBP1) mRNA in multiple cancer cells suggested ER stress as the general event triggered by PAC-1. XBP1 mRNA splicing and GRP78 upregulation confirmed ER stress even in Bax/Bak double knockout and PAC-1-resistant Apaf-1-knockout cells, indicating an induction of ER stress-mediated mitochondrial apoptosis by PAC-1. Furthermore, we identified BH3-only protein p53 upregulated modulator of apoptosis (PUMA) as the key molecular link that orchestrates overwhelmed ER stress to mitochondria-mediated apoptosis, involving mitochondrial reactive oxygen species, in a p53-independent manner. Silencing of PUMA in cancer cells effectively reduced cyt. c release and cell death by PAC-1.

  5. ERO1α-dependent endoplasmic reticulum–mitochondrial calcium flux contributes to ER stress and mitochondrial permeabilization by procaspase-activating compound-1 (PAC-1)

    Science.gov (United States)

    Seervi, M; Sobhan, P K; Joseph, J; Ann Mathew, K; Santhoshkumar, T R

    2013-01-01

    Procaspase-activating compound-1 (PAC-1) is the first direct caspase-activating compound discovered; using an in vitro cell-free system of caspase activation. Subsequently, this compound was shown to induce apoptosis in a variety of cancer cells with promising in vivo antitumor activity in canine lymphoma model. Recently, we have reported its ability to kill drug-resistant, Bcl-2/Bcl-xL overexpressing and Bax/Bak-deficient cells despite the essential requirement of mitochondrial cytochrome c (cyt. c) release for caspase activation, indicating that the key molecular targets of PAC-1 in cancer cells are yet to be identified. Here, we have identified Ero1α-dependent endoplasmic reticulum (ER) calcium leakage to mitochondria through mitochondria-associated ER membranes (MAM) and ER luminal hyper-oxidation as the critical events of PAC-1-mediated cell death. PAC-1 treatment upregulated Ero1α in multiple cell lines, whereas silencing of Ero1α significantly inhibited calcium release from ER and cell death. Loss of ER calcium and hyper-oxidation of ER lumen by Ero1α collectively triggered ER stress. Upregulation of GRP78 and splicing of X-box-binding protein 1 (XBP1) mRNA in multiple cancer cells suggested ER stress as the general event triggered by PAC-1. XBP1 mRNA splicing and GRP78 upregulation confirmed ER stress even in Bax/Bak double knockout and PAC-1-resistant Apaf-1-knockout cells, indicating an induction of ER stress-mediated mitochondrial apoptosis by PAC-1. Furthermore, we identified BH3-only protein p53 upregulated modulator of apoptosis (PUMA) as the key molecular link that orchestrates overwhelmed ER stress to mitochondria-mediated apoptosis, involving mitochondrial reactive oxygen species, in a p53-independent manner. Silencing of PUMA in cancer cells effectively reduced cyt. c release and cell death by PAC-1. PMID:24357799

  6. ER Stress Induced by Tunicamycin Triggers α-Synuclein Oligomerization, Dopaminergic Neurons Death and Locomotor Impairment: a New Model of Parkinson's Disease.

    Science.gov (United States)

    Cóppola-Segovia, Valentín; Cavarsan, Clarissa; Maia, Flavia G; Ferraz, Anete C; Nakao, Lia S; Lima, Marcelo Ms; Zanata, Silvio M

    2017-10-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive death of dopaminergic neurons of the substantia nigra pars compacta (SNpc), leading to the major clinical abnormalities that characterize this disease. Although PD's etiology is unknown, α-synuclein aggregation plays a pivotal role in PD pathogenesis, which could be associated to some pathological processes such as oxidative stress, endoplasmic reticulum (ER) stress, impaired protein degradation, and mitochondrial dysfunction. Increasing experimental evidence indicates that ER stress is involved in PD, however most of the described results employed cultured cell lines and genetically modified animal models. In this study, we developed a new ER stress rat model employing the well-known ER stressor tunicamycin (Tm). To evaluate if ER stress was able to induce PD features, we performed an intranigral injection of Tm (0.1 μg/cerebral hemisphere) and animals (male Wistar rats) were analyzed 7 days post injection. The classical 6-OHDA neurotoxin model (1 μg/cerebral hemisphere) was used as an established positive control for PD. We show that Tm injection induced locomotor impairment, dopaminergic neurons death, and activation of astroglia. In addition, we observed an extensive α-synuclein oligomerization in SNpc of Tm-injected animals when compared with DMSO-injected controls. Finally, both Tm and 6-OHDA treated animals presented increased levels of ER stress markers. Taken together, these findings show for the first time that the ER stressor Tm recapitulates some of the phenotypic characteristics observed in rodent models of PD, reinforcing the concept that ER stress could be an important contributor to the pathophysiology of PD. Therefore, we propose the intranigral Tm injection as a new ER stress-based model for the study of PD in vivo.

  7. The ER stress sensor PERK luminal domain functions as a molecular chaperone to interact with misfolded proteins

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng; Li, Jingzhi; Sha, Bingdong

    2016-11-29

    PERK is one of the major sensor proteins which can detect the protein-folding imbalance generated by endoplasmic reticulum (ER) stress. It remains unclear how the sensor protein PERK is activated by ER stress. It has been demonstrated that the PERK luminal domain can recognize and selectively interact with misfolded proteins but not native proteins. Moreover, the PERK luminal domain may function as a molecular chaperone to directly bind to and suppress the aggregation of a number of misfolded model proteins. The data strongly support the hypothesis that the PERK luminal domain can interact directly with misfolded proteins to induce ER stress signaling. To illustrate the mechanism by which the PERK luminal domain interacts with misfolded proteins, the crystal structure of the human PERK luminal domain was determined to 3.2 Å resolution. Two dimers of the PERK luminal domain constitute a tetramer in the asymmetric unit. Superimposition of the PERK luminal domain molecules indicated that the β-sandwich domain could adopt multiple conformations. It is hypothesized that the PERK luminal domain may utilize its flexible β-sandwich domain to recognize and interact with a broad range of misfolded proteins.

  8. DHA induces ER stress and growth arrest in human colon cancer cells: associations with cholesterol and calcium homeostasis *s⃞

    Science.gov (United States)

    Jakobsen, Caroline Hild; Størvold, Gro Leite; Bremseth, Hilde; Follestad, Turid; Sand, Kristin; Mack, Merete; Olsen, Karina Standahl; Lundemo, Anne Gøril; Iversen, Jens Gustav; Krokan, Hans Einar; Schønberg, Svanhild Arentz

    2008-01-01

    Polyunsaturated fatty acids (PUFAs) are normal constituents of the diet, but have properties different from other fatty acids (e.g., through generation of signaling molecules). N-3 PUFAs reduce cancer cell growth, but no unified mechanism has been identified. We show that docosahexaenoic acid (DHA; 22:6 n-3) causes extensive changes in gene expression patterns at mRNA level in the colon cancer cell line SW620. Early changes include unfolded protein response (UPR) and increased levels of phosphorylated eIF2α as verified at protein level. The latter is considered a hallmark of endoplasmic reticulum (ER) stress and is abundantly present already after 3 h. It may coordinate many of the downstream changes observed, including signaling pathways for cell cycle arrest/apoptosis, calcium homeostasis, cholesterol metabolism, ubiquitination, and proteasomal degradation. Also, eicosapentaenoic acid (EPA), but not oleic acid (OA), induced key mediators of ER stress and UPR at protein level. Accumulation of esterified cholesterol was not compensated for by increased total levels of cholesterol, and mRNAs for cholesterol biosynthesis as well as de novo synthesis of cholesterol were reduced. These results suggest that cytotoxic effects of DHA are associated with signaling pathways involving lipid metabolism and ER stress. PMID:18566476

  9. Astragalus polysaccharide modulates ER stress response in an OVA-LPS induced murine model of severe asthma.

    Science.gov (United States)

    Lu, Yuan; Xing, Qiong-Qiong; Xu, Jian-Ya; Ding, Dou; Zhao, Xia

    2016-12-01

    Endoplasmic reticulum (ER) stress has been recently revealed to play a pivotal role in the pathogenesis of severe asthma. Astragalus polysaccharide (APS), a major bioactive component from Astragalus membranaceus, exerts immunomodulatory and anti-inflammatory effects and has been shown to suppress ER stress in chronic diseases such as type-2 diabetes. However, the pharmaceutical application of APS in the treatment of severe asthma is unknown. The results obtained here indicate that APS significantly attenuates eosinophils and neutrophil-dominant airway inflammation by reducing the mRNA levels of Cxcl5, Il8, and chemokine (C-C motif) ligand 20 (Ccl20) and the protein levels of IL13RA and IL17RA. APS also inhibits the activation of unfolded protein response by decreasing the levels of ER stress markers such as C/EBP homologous protein (CHOP), which was associated with a reduction of PERK phosphorylation. Moreover, APS substantially blocks the nuclear translocation of ATF6 and NF-κB p65. Interestingly, we observed that APS markedly suppresses mucus hypersecretion by decreasing the levels of mucin (MUC) 5AC and MUC5B, which might be due to inhibition of goblet cells differentiation by suppressing the expression of IRE1β-correlated genes. In summary, APS can have potential pharmaceutical application in treatment of severe asthma. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The metabolic ER stress sensor IRE1α suppresses alternative activation of macrophages and impairs energy expenditure in obesity.

    Science.gov (United States)

    Shan, Bo; Wang, Xiaoxia; Wu, Ying; Xu, Chi; Xia, Zhixiong; Dai, Jianli; Shao, Mengle; Zhao, Feng; He, Shengqi; Yang, Liu; Zhang, Mingliang; Nan, Fajun; Li, Jia; Liu, Jianmiao; Liu, Jianfeng; Jia, Weiping; Qiu, Yifu; Song, Baoliang; Han, Jing-Dong J; Rui, Liangyou; Duan, Sheng-Zhong; Liu, Yong

    2017-05-01

    Obesity is associated with metabolic inflammation and endoplasmic reticulum (ER) stress, both of which promote metabolic disease progression. Adipose tissue macrophages (ATMs) are key players orchestrating metabolic inflammation, and ER stress enhances macrophage activation. However, whether ER stress pathways underlie ATM regulation of energy homeostasis remains unclear. Here, we identified inositol-requiring enzyme 1α (IRE1α) as a critical switch governing M1-M2 macrophage polarization and energy balance. Myeloid-specific IRE1α abrogation in Ern1 f/f ; Lyz2-Cre mice largely reversed high-fat diet (HFD)-induced M1-M2 imbalance in white adipose tissue (WAT) and blocked HFD-induced obesity, insulin resistance, hyperlipidemia and hepatic steatosis. Brown adipose tissue (BAT) activity, WAT browning and energy expenditure were significantly higher in Ern1 f/f ; Lyz2-Cre mice. Furthermore, IRE1α ablation augmented M2 polarization of macrophages in a cell-autonomous manner. Thus, IRE1α senses protein unfolding and metabolic and immunological states, and consequently guides ATM polarization. The macrophage IRE1α pathway drives obesity and metabolic syndrome through impairing BAT activity and WAT browning.

  11. ER stress activates NF-κB by integrating functions of basal IKK activity, IRE1 and PERK.

    Directory of Open Access Journals (Sweden)

    Arvin B Tam

    Full Text Available NF-κB, a transcription factor, becomes activated during the Unfolded Protein Response (UPR, an endoplasmic reticulum (ER stress response pathway. NF-κB is normally held inactive by its inhibitor, IκBα. Multiple cellular pathways activate IKK (IκBα Kinase which phosphorylate IκBα leading to its degradation and NF-κB activation. Here, we find that IKK is required for maximum activation of NF-κB in response to ER stress. However, unlike canonical NFκB activation, IKK activity does not increase during ER stress, but rather the level of basal IKK activity is critical for determining the extent of NF-κB activation. Furthermore, a key UPR initiator, IRE1, acts to maintain IKK basal activity through IRE1's kinase, but not RNase, activity. Inputs from IRE1 and IKK, in combination with translation repression by PERK, another UPR initiator, lead to maximal NF-κB activation during the UPR. These interdependencies have a significant impact in cancer cells with elevated IKK/NF-κB activity such as renal cell carcinoma cells (786-0. Inhibition of IKK by an IKK inhibitor, which significantly decreases NF-κB activity, is overridden by UPR induction, arguing for the importance of considering UPR activation in cancer treatment.

  12. Paradoxical effects of sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) activator gingerol on NG115-401L neuronal cells: failure to augment ER Ca(2+) uptake and protect against ER stress-induced cell death.

    Science.gov (United States)

    Zhang, Changfeng; Bose, Diptiman D; Thomas, David W

    2015-09-05

    Perturbation of endoplasmic reticulum (ER) Ca(2+) homeostasis and ER stress are thought to underlie a spectrum of defects encompassing major societal diseases such as diabetes and neurodegeneration. In this report we used the NG115-401L neuronal cell line to test the hypothesis that neuroprotection against ER stress may be conferred by pharmacological stimulation of the sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) pumps. We report that the SERCA activator gingerol stimulates SR microsomal Ca(2+)-ATPase activity and restores enzymatic function in the presence of potent SERCA blockers. Yet, enzyme protection in isolated membranes does not extend to protection from ER stress in intact NG115-401L cells. Surprisingly, gingerol not only failed to protect cells from SERCA blocker-induced ER stress and cell death, the compound itself potently induced cell death. Also, we report that gingerol failed to augment ER Ca(2+) uptake, a result contradictory to what has been observed in muscle. Unexpectedly, gingerol discharged ER Ca(2+) stores and coupled robustly to Ca(2+) influx pathways. These observations suggest that gingerol is not acting as a traditional SERCA blocker as thapsigargin mediated ER Ca(2+) store depletion fails to stimulate Ca(2+) influx in the NG115-401L cell phenotype. Moreover, cell death induced by gingerol, in contrast to the classic SERCA inhibitors, is not accompanied by increases in reactive oxygen species production or enzymatic caspase activity. These results argue for a finer regulatory control on SERCA function with gingerol's actions revealing potentially novel routes of coupling altered pump regulation to the assembly of functional Ca(2+) influx units and activation of cell death pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Stress

    OpenAIRE

    Jensen, Line Skov; Lova, Lotte; Hansen, Zandra Kulikovsky; Schønemann, Emilie; Larsen, Line Lyngby; Colberg Olsen, Maria Sophia; Juhl, Nadja; Magnussen, Bogi Roin

    2012-01-01

    Stress er en tilstand som er meget omdiskuteret i samfundet, og dette besværliggør i en vis grad konkretiseringen af mulige løsningsforslag i bestræbelsen på at forebygge den såkaldte folkesygdom. Hovedkonklusionen er, at selv om der bliver gjort meget for at forebygge, er der ikke meget der aktivt kan sættes i værk for at reducere antallet af stressramte, før en fælles forståelse af stressårsager og effektiv stresshåndtering er fremlagt. Problemformuleringen er besvaret gennem en undersø...

  14. ER stress in retinal degeneration in S334ter Rho rats.

    Directory of Open Access Journals (Sweden)

    Vishal M Shinde

    Full Text Available The S334ter rhodopsin (Rho rat (line 4 bears the rhodopsin gene with an early termination codon at residue 334 that is a model for several such mutations found in human patients with autosomal dominant retinitis pigmentosa (ADRP. The Unfolded Protein Response (UPR is implicated in the pathophysiology of several retinal disorders including ADRP in P23H Rho rats. The aim of this study was to examine the onset of UPR gene expression in S334ter Rho retinas to determine if UPR is activated in ADRP animal models and to investigate how the activation of UPR molecules leads to the final demise of S334ter Rho photoreceptors. RT-PCR was performed to evaluate the gene expression profiles for the P10, P12, P15, and P21 stages of the development and progression of ADRP in S334ter Rho photoreceptors. We determined that during the P12-P15 period, ER stress-related genes are strongly upregulated in transgenic retinas, resulting in the activation of the UPR that was confirmed using western blot analysis and RT-PCR. The activation of UPR was associated with the increased expression of JNK, Bik, Bim, Bid, Noxa, and Puma genes and cleavage of caspase-12 that together with activated calpains presumably compromise the integrity of the mitochondrial MPTP, leading to the release of pro-apoptotic AIF1 into the cytosol of S334ter Rho photoreceptor cells. Therefore, two major cross-talking pathways, the UPR and mitochondrial MPTP occur in S334ter-4 Rho retina concomitantly and eventually promote the death of the photoreceptor cells.

  15. Enhanced endoplasmic reticulum SERCA activity by overexpression of hepatic stimulator substance gene prevents hepatic cells from ER stress-induced apoptosis.

    Science.gov (United States)

    Zhang, Jing; Li, Yuan; Jiang, Shujun; Yu, Hao; An, Wei

    2014-02-01

    Although the potential pathogenesis of nonalcoholic fatty liver disease (NAFLD) is unclear, increasing evidence indicates that endoplasmic reticulum (ER) stress may link free fatty acids to NAFLD. Since we previously reported that hepatic stimulator substance (HSS) could protect the liver from steatosis, this study is aimed to investigate whether HSS protection could be related with its inhibition on ER stress. The HSS gene was stably transfected into BEL-7402 hepatoma cells and effectively expressed in ER. The palmitic acid (PA)-induced heptocyte lipotoxicity was reproduced in the HSS-transfected cells, and HSS alleviation of the ER stress and apoptosis were subsequently examined. The results showed that PA treatment led to a heavy accumulation of fatty acids within the cells and a remarkable increase in reactive oxygen species (ROS). However, in the HSS-expressing cells, production of ROS was inhibited and ER stress-related marker glucose-regulated protein 78 (GRP-78), sterol regulatory element-binding protein (SREBP), anti-phospho-PRK-1ike ER kinase (p-PERK), anti-phospho-eukaryotic initiation factor 2α (p-eIF2α), and anti-C/EBP homologous protein (CHOP) were downregulated compared with the wild-type or mutant HSS-transfected cells. Furthermore, PA treatment severely impaired the activity of sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA), leading to imbalanced calcium homeostasis during ER stress, which could be rescued in the HSS-trasfected cells. The protection provided by HSS to the SERCA is identical to that observed with N-acetyl-l-cysteine (NAC) and sodium dimercaptopropane sulfonate (Na-DMPS), which are two typical free radical scavengers. As a consequence, the rate of ER stress-mediated apoptosis in the HSS-expressing cells was significantly reduced. In conclusion, the protective effect of HSS against ER stress may be associated with the removal of ROS to restore the activity of the SERCA.

  16. Adaptation and survival of plants in high stress habitats via fungal endophyte conferred stress tolerance

    Science.gov (United States)

    Rodriguez, Rusty J.; Woodward, Claire; Redman, Regina S.

    2010-01-01

    From the Arctic to the Antarctic, plants thrive in diverse habitats that impose different levels of adaptive pressures depending on the type and degree of biotic and abiotic stresses inherent to each habitat (Stevens, 1989). At any particular location, the abundance and distribution of individual plant species vary tremendously and is theorized to be based on the ability to tolerate a wide range of edaphic conditions and habitat-specific stresses (Pianka, 1966). The ability of individual plant species to thrive in diverse habitats is commonly referred to as phenotypic plasticity and is thought to involve adaptations based on changes in the plant genome (Givnish, 2002; Pan et al., 2006; Robe and Griffiths, 2000; Schurr et al., 2006). Habitats that impose high levels of abiotic stress are typically colonized with fewer plant species compared to habitats imposing low levels of stress. Moreover, high stress habitats have decreased levels of plant abundance compared to low stress habitats even though these habitats may occur in close proximity to one another (Perelman et al., 2007). This is particularly interesting because all plants are known to perceive, transmit signals, and respond to abiotic stresses such as drought, heat, and salinity (Bartels and Sunkar, 2005; Bohnert et al., 1995). Although there has been extensive research performed to determine the genetic, molecular, and physiological bases of how plants respond to and tolerate stress, the nature of plant adaptation to high stress habitats remains unresolved (Leone et al., 2003; Maggio et al., 2003; Tuberosa et al., 2003). However, recent evidence indicates that a ubiquitous aspect of plant biology (fungal symbiosis) is involved in the adaptation and survival of at least some plants in high stress habitats (Rodriguez et al., 2008).

  17. N-rich protein (NRP)-mediated cell death signaling: a new branch of the ER stress response with implications for plant biotechnology.

    Science.gov (United States)

    Reis, Pedro A B; Fontes, Elizabeth P B

    2012-06-01

    Upon disruption of ER homeostasis, plant cells activate at least two branches of the unfolded protein response (UPR) through IRE1-like and ATAF6-like transducers, resulting in the upregulation of ER-resident molecular chaperones and the activation of the ER-associated degradation protein system. Here, we discuss a new ER stress response pathway in plants that is associated with an osmotic stress response in transducing a cell death signal. Both ER and osmotic stress induce the expression of the novel transcription factor GmERD15, which binds and activates N-rich protein (NRP) promoters to induce NRP expression and cause the upregulation of GmNAC6, an effector of the cell death response. In contrast to this activation mechanism, the ER-resident molecular chaperone binding protein (BiP) attenuates the propagation of the cell death signal by modulating the expression and activity of components of the ER and osmotic stress-induced NRP-mediated cell death signaling. This interaction attenuates dehydration-induced cell death and promotes a better adaptation of BiP-overexpressing transgenic lines to drought.

  18. ERLIN2 promotes breast cancer cell survival by modulating endoplasmic reticulum stress pathways

    Directory of Open Access Journals (Sweden)

    Wang Guohui

    2012-06-01

    Full Text Available Abstract Background Amplification of the 8p11-12 region has been found in approximately 15% of human breast cancer and is associated with poor prognosis. Previous genomic analysis has led us to identify the endoplasmic reticulum (ER lipid raft-associated 2 (ERLIN2 gene as one of the candidate oncogenes within the 8p11-12 amplicon in human breast cancer, particularly in the luminal subtype. ERLIN2, an ER membrane protein, has recently been identified as a novel mediator of ER-associated degradation. Yet, the biological roles of ERLIN2 and molecular mechanisms by which ERLIN2 coordinates ER pathways in breast carcinogenesis remain unclear. Methods We established the MCF10A-ERLIN2 cell line, which stably over expresses ERLIN2 in human nontransformed mammary epithelial cells (MCF10A using the pLenti6/V5-ERLIN2 construct. ERLIN2 over expressing cells and their respective parental cell lines were assayed for in vitro transforming phenotypes. Next, we knocked down the ERLIN2 as well as the ER stress sensor IRE1α activity in the breast cancer cell lines to characterize the biological roles and molecular basis of the ERLIN2 in carcinogenesis. Finally, immunohistochemical staining was performed to detect ERLIN2 expression in normal and cancerous human breast tissues Results We found that amplification of the ERLIN2 gene and over expression of the ERLIN2 protein occurs in both luminal and Her2 subtypes of breast cancer. Gain- and loss-of-function approaches demonstrated that ERLIN2 is a novel oncogenic factor associated with the ER stress response pathway. The IRE1α/XBP1 axis in the ER stress pathway modulated expression of ERLIN2 protein levels in breast cancer cells. We also showed that over expression of ERLIN2 facilitated the adaptation of breast epithelial cells to ER stress by supporting cell growth and protecting the cells from ER stress-induced cell death. Conclusions ERLIN2 may confer a selective growth advantage for breast cancer cells by

  19. Gliadin peptides induce tissue transglutaminase activation and ER-stress through Ca2+ mobilization in Caco-2 cells.

    Directory of Open Access Journals (Sweden)

    Ivana Caputo

    Full Text Available BACKGROUND: Celiac disease (CD is an intestinal inflammatory condition that develops in genetically susceptible individuals after exposure to dietary wheat gliadin. The role of post-translational modifications of gliadin catalyzed by tissue transglutaminase (tTG seems to play a crucial role in CD. However, it remains to be established how and where tTG is activated in vivo. We have investigated whether gliadin peptides modulate intracellular Ca(2+ homeostasis and tTG activity. METHODS/PRINCIPAL FINDINGS: We studied Ca(2+ homeostasis in Caco-2 cells by single cell microfluorimetry. Under our conditions, A-gliadin peptides 31-43 and 57-68 rapidly mobilized Ca(2+ from intracellular stores. Specifically, peptide 31-43 mobilized Ca(2+ from the endoplasmic reticulum (ER and mitochondria, whereas peptide 57-68 mobilized Ca(2+ only from mitochondria. We also found that gliadin peptide-induced Ca(2+ mobilization activates the enzymatic function of intracellular tTG as revealed by in situ tTG activity using the tTG substrate pentylamine-biotin. Moreover, we demonstrate that peptide 31-43, but not peptide 57-68, induces an increase of tTG expression. Finally, we monitored the expression of glucose-regulated protein-78 and of CCAAT/enhancer binding protein-homologous protein, which are two biochemical markers of ER-stress, by real-time RT-PCR and western blot. We found that chronic administration of peptide 31-43, but not of peptide 57-68, induces the expression of both genes. CONCLUSIONS: By inducing Ca(2+ mobilization from the ER, peptide 31-43 could promote an ER-stress pathway that may be relevant in CD pathogenesis. Furthermore, peptides 31-43 and 57-68, by activating intracellular tTG, could alter inflammatory key regulators, and induce deamidation of immunogenic peptides and gliadin-tTG crosslinking in enterocytes and specialized antigen-presenting cells.

  20. Two-gene signature improves the discriminatory power of IASLC/ATS/ERS classification to predict the survival of patients with early-stage lung adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Sun Y

    2016-07-01

    Full Text Available Yifeng Sun,1,* Likun Hou,2,* Yu Yang,1 Huikang Xie,2 Yang Yang,1 Zhigang Li,1 Heng Zhao,1 Wen Gao,3 Bo Su4 1Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiaotong University, 2Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, 3Department of Thoracic Surgery, Shanghai Huadong Hospital, Fudan University School of Medicine, Shanghai, 4Central Lab, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: In this study, we investigated the contribution of a gene expression–based signature (composed of BAG1, BRCA1, CDC6, CDK2AP1, ERBB3, FUT3, IL11, LCK, RND3, SH3BGR to survival prediction for early-stage lung adenocarcinoma categorized by the new International Association for the Study of Lung Cancer (IASLC/the American Thoracic Society (ATS/the European Respiratory Society (ERS classification. We also aimed to verify whether gene signature improves the risk discrimination of IASLC/ATS/ERS classification in early-stage lung adenocarcinoma. Patients and methods: Total RNA was extracted from 93 patients with pathologically confirmed TNM stage Ia and Ib lung adenocarcinoma. The mRNA expression levels of ten genes in the signature (BAG1, BRCA1, CDC6, CDK2AP1, ERBB3, FUT3, IL11, LCK, RND3, and SH3BGR were detected using real-time polymerase chain reaction. Each patient was categorized according to the new IASLC/ATS/ERS classification by accessing hematoxylin–eosin-stained slides. The corresponding Kaplan–Meier survival analysis by the log-rank statistic, multivariate Cox proportional hazards modeling, and c-index calculation were conducted using the programming language R (Version 2.15.1 with the “risksetROC” package. Results: The multivariate analysis demonstrated that the risk factor of the ten-gene expression signature can significantly improve the discriminatory

  1. Familial CJD associated PrP mutants within transmembrane region induced Ctm-PrP retention in ER and triggered apoptosis by ER stress in SH-SY5Y cells.

    Directory of Open Access Journals (Sweden)

    Xin Wang

    Full Text Available BACKGROUND: Genetic prion diseases are linked to point and inserted mutations in the prion protein (PrP gene that are presumed to favor conversion of the cellular isoform of PrP (PrP(C to the pathogenic one (PrP(Sc. The pathogenic mechanisms and the subcellular sites of the conversion are not completely understood. Here we introduce several PRNP gene mutations (such as, PrP-KDEL, PrP-3AV, PrP-A117V, PrP-G114V, PrP-P102L and PrP-E200K into the cultured cells in order to explore the pathogenic mechanism of familial prion disease. METHODOLOGY/PRINCIPAL FINDINGS: To address the roles of aberrant retention of PrP in endoplasmic reticulum (ER, the recombinant plasmids expressing full-length human PrP tailed with an ER signal peptide at the COOH-terminal (PrP-KDEL and PrP with three amino acids exchange in transmembrane region (PrP-3AV were constructed. In the preparations of transient transfections, 18-kD COOH-terminal proteolytic resistant fragments (Ctm-PrP were detected in the cells expressing PrP-KDEL and PrP-3AV. Analyses of the cell viabilities in the presences of tunicamycin and brefeldin A revealed that expressions of PrP-KDEL and PrP-3AV sensitized the transfected cells to ER stress stimuli. Western blots and RT-PCR identified the clear alternations of ER stress associated events in the cells expressing PrP-KDEL and PrP-3AV that induced ER mediated apoptosis by CHOP and caspase-12 apoptosis pathway. Moreover, several familial CJD related PrP mutants were transiently introduced into the cultured cells. Only the mutants within the transmembrane region (G114V and A117V induced the formation of Ctm-PrP and caused the ER stress, while the mutants outside the transmembrane region (P102L and E200K failed. CONCLUSIONS/SIGNIFICANCE: The data indicate that the retention of PrP in ER through formation of Ctm-PrP results in ER stress and cell apoptosis. The cytopathic activities caused by different familial CJD associated PrP mutants may vary, among them

  2. Role of ER stress response in photodynamic therapy: ROS generated in different subcellular compartments trigger diverse cell death pathways.

    Directory of Open Access Journals (Sweden)

    Irena Moserova

    Full Text Available We have analyzed the molecular mechanisms of photoinduced cell death using porphyrins with similar structure differing only in the position of the ethylene glycol (EG chain on the phenyl ring. Meta- and para-positioned EG chains targeted porphyrins to different subcellular compartments. After photoactivation, both types of derivatives induced death of tumor cells via reactive oxygen species (ROS. Para derivatives pTPP(EG4 and pTPPF(EG4 primarily accumulated in lysosomes activated the p38 MAP kinase cascade, which in turn induced the mitochondrial apoptotic pathway. In contrast, meta porphyrin derivative mTPP(EG4 localized in the endoplasmic reticulum (ER induced dramatic changes in Ca(2+ homeostasis manifested by Ca(2+ rise in the cytoplasm, activation of calpains and stress caspase-12 or caspase-4. ER stress developed into unfolded protein response. Immediately after irradiation the PERK pathway was activated through phosphorylation of PERK, eIF2α and induction of transcription factors ATF4 and CHOP, which regulate stress response genes. PERK knockdown and PERK deficiency protected cells against mTPP(EG4-mediated apoptosis, confirming the causative role of the PERK pathway.

  3. Survival is associated with complete response on MRI after neoadjuvant chemotherapy in ER-positive HER2-negative breast cancer

    NARCIS (Netherlands)

    Loo, Claudette E; Rigter, Lisanne S; Pengel, Kenneth E; Wesseling, Jelle; Rodenhuis, Sjoerd; Peeters, Marie-Jeanne T F D Vrancken; Sikorska, Karolina; Gilhuijs, Kenneth G A|info:eu-repo/dai/nl/143937979

    2016-01-01

    BACKGROUND: Pathological complete remission (pCR) of estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer is rarely achieved after neoadjuvant chemotherapy (NAC). In addition, the prognostic value of pCR for this breast cancer subtype is limited. We

  4. SCS3 and YFT2 link transcription of phospholipid biosynthetic genes to ER stress and the UPR.

    Directory of Open Access Journals (Sweden)

    Robyn D Moir

    2012-08-01

    Full Text Available The ability to store nutrients in lipid droplets (LDs is an ancient function that provides the primary source of metabolic energy during periods of nutrient insufficiency and between meals. The Fat storage-Inducing Transmembrane (FIT proteins are conserved ER-resident proteins that facilitate fat storage by partitioning energy-rich triglycerides into LDs. FIT2, the ancient ortholog of the FIT gene family first identified in mammals has two homologs in Saccharomyces cerevisiae (SCS3 and YFT2 and other fungi of the Saccharomycotina lineage. Despite the coevolution of these genes for more than 170 million years and their divergence from higher eukaryotes, SCS3, YFT2, and the human FIT2 gene retain some common functions: expression of the yeast genes in a human embryonic kidney cell line promotes LD formation, and expression of human FIT2 in yeast rescues the inositol auxotrophy and chemical and genetic phenotypes of strains lacking SCS3. To better understand the function of SCS3 and YFT2, we investigated the chemical sensitivities of strains deleted for either or both genes and identified synthetic genetic interactions against the viable yeast gene-deletion collection. We show that SCS3 and YFT2 have shared and unique functions that connect major biosynthetic processes critical for cell growth. These include lipid metabolism, vesicular trafficking, transcription of phospholipid biosynthetic genes, and protein synthesis. The genetic data indicate that optimal strain fitness requires a balance between phospholipid synthesis and protein synthesis and that deletion of SCS3 and YFT2 impacts a regulatory mechanism that coordinates these processes. Part of this mechanism involves a role for SCS3 in communicating changes in the ER (e.g. due to low inositol to Opi1-regulated transcription of phospholipid biosynthetic genes. We conclude that SCS3 and YFT2 are required for normal ER membrane biosynthesis in response to perturbations in lipid metabolism and ER

  5. XBP1-LOX Axis is critical in ER stress-induced growth of lung adenocarcinoma in 3D culture.

    Science.gov (United States)

    Yang, Yi; Cheng, Bai-Jun; Jian, Hong; Chen, Zhi-Wei; Zhao, Yi; Yu, Yong-Feng; Li, Zi-Ming; Liao, Mei-Lin; Lu, Shun

    2017-01-01

    Rapid growth of tumor cells needs to consume large amounts of oxygen and glucose, due to lack of blood supply within the tumor, cells live in an environment that lack of oxygen and nutrients. This environment results in endoplasmic reticulum (ER) stress and activates the UPR (unfolded protein response). More and more evidence suggests UPR provides a growth signal pathway required for tumor growth. In the present study, we investigated the relationship between XBP1, one transcription factor in UPR, and the expression of LOX. We found that ER stress induces high expression of XBP1, one transcription factor in UPR, in both 2D culture and 3D culture; but only promotes growth of lung adenocarcinoma cells in in vitro 3D culture other than 2D culture. In 3D culture, we further showed that knockdown XBP1 expression can block Tm/Tg-induced cell growth. LOX genes may be key downstream effector of XBP1. Knockdown LOX expression can partially block XBP1-induced cell growth. Then we showed XBP1 suppressed by RNA interference (RNAi) can reduce the expression of LOX. For the first time, it is being shown that XBP1 can regulate the expression of LOX to promote cell growth.

  6. Activation of ER stress and apoptosis by α- and β-zearalenol in HCT116 cells, protective role of Quercetin.

    Science.gov (United States)

    Ben Salem, Intidhar; Prola, Alexandre; Boussabbeh, Manel; Guilbert, Arnaud; Bacha, Hassen; Lemaire, Christophe; Abid-Essefi, Salwa

    2016-03-01

    Zearalenone (ZEN) and its metabolites are found in many food products and are known to induce many toxic effects. The major ZEN metabolites are α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL). The mechanisms by which they mediate their cytotoxic effects are not well known and seem to differ depending on the type of cells. We investigated the possible underlying mechanism in α-ZOL and β-ZOL-induced toxicity in HCT116 cells. We showed that cell treatment with α-ZOL/β-ZOL generated endoplasmic reticulum (ER) stress and activated the Unfolded Protein Response (UPR) as evidenced by XBP1 mRNA splicing and up-regulation of GADD34, GRP78, ATF4 and CHOP. Apoptosis was triggered by ZEN metabolites-induced ER stress, and executed through a mitochondria-dependent pathway, characterized by a loss of mitochondrial transmembrane potential (ΔΨm), a downstream generation of O2•(-) and caspase 3 activation. Cellular deficiency of the pro-apoptotic proteins Bax and Bak protected cells against α/β-ZOL-induced toxicity. However, treatment with α-ZOL or β-ZOL combined with Quercetin (QUER), a common dietary flavonoid with well-known antioxidant activity, significantly reduced damage induced by α and β-ZOL in all tested markers. We concluded that QUER protects against the cellular toxicity of α and β-ZOL.×. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Crocin and quercetin prevent PAT-induced apoptosis in mammalian cells: Involvement of ROS-mediated ER stress pathway.

    Science.gov (United States)

    Boussabbeh, Manel; Prola, Alexandre; Ben Salem, Intidhar; Guilbert, Arnaud; Bacha, Hassen; Lemaire, Christophe; Abis-Essefi, Salwa

    2016-12-01

    Patulin (PAT) is a secondary metabolite produced by several species of the genera of Penicillium, Aspergillus, and Byssochlamys that can be found in rotting fruits, especially in apples and apple-based products. Exposure to this mycotoxin has been reported to induce intestinal and kidney injuries. The mechanism underlying such toxicity has been linked to the induction of apoptosis which occurred with reactive oxygen species production and endoplasmic reticulum (ER) stress induction. This study aimed to evaluate the effect of the two common dietary compounds Quercetin (QUER), a natural flavonoid, and Crocin (CRO), a natural carotenoid, on PAT-induced toxicity in human colon carcinoma (HCT116) and embryonic kidney cells (HEK293). We showed that antioxidant properties of QUER and CRO help to prevent ER stress activation and lipid peroxidation as evidenced by the reduction in GRP78 and GADD34 expressions and the decrease in malondialdehyde production. Furthermore, we demonstrated their ability to re-establish the loss of the mitochondrial membrane potential to inhibit caspase 3 activation and DNA fragmentation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1851-1858, 2016. © 2015 Wiley Periodicals, Inc.

  8. Effects of ochratoxin A on ER stress, MAPK signaling pathway and autophagy of kidney and spleen in pigs.

    Science.gov (United States)

    Gan, Fang; Hou, Lili; Zhou, Yajiao; Liu, Yunhuan; Huang, Da; Chen, Xingxiang; Huang, Kehe

    2017-10-01

    Ochratoxin A (OTA), a worldwide mycotoxin found in food and feeds, is a potent nephrotoxin and immunotoxin in animals and humans. This research was conducted to evaluate whether endoplasmic reticulum (ER) stress, MAPK signaling pathway and autophagy were induced by OTA in kidney and spleen of pigs. Twenty-seven crossbred pigs randomly allocated to 3 groups were fed for 42 days ad libitum a basal diet without (Con group, 0.00 μg OTA/kg) and with supplementation of OTA at 400 (OTA-L group) and 800 μg/kg (OTA-H group). From each group, 6 pigs were randomly selected for blood collection on days 0, 21, and 42 and 3 pigs were randomly selected for tissue collection on day 42. The results showed that OTA at 400 and 800 μg/kg diets significantly increased OTA concentrations in serum and kidney and spleen induced the histopathological lesions of kidney and spleen, decreased TCR-stimulated T lymphocyte viabilities and IL-2 concentration, increased TNF-α concentration, and decreased T-AOC levels. OTA increased glucose regulated protein 78, p38, and ERK1/2 phosphorylation, and LC3 II and Atg5 protein expression in kidney and spleen of pigs. These results provide new insights into the relationship between OTA and ER stress, p38 and ERK1/2 MAPK signaling pathway and autophagy in pigs. © 2017 Wiley Periodicals, Inc.

  9. Autophagy and ER stress play an essential role in the mechanism of action and drug resistance of the cyclin-dependent kinase inhibitor flavopiridol.

    Science.gov (United States)

    Mahoney, Emilia; Byrd, John C; Johnson, Amy J

    2013-03-01

    Chronic lymphocytic leukemia (CLL) is a mature B cell malignancy and is the most prevalent type of leukemia in adults. There is no curative therapy for this disease; however, several new agents have shown very promising results. Autophagy has not been studied in CLL and in this study we first sought to determine if autophagy was functional in CLL with classic inducers, and if this contributes to direct cytotoxicity or protection from cell death. While autophagy is activated with all classic stimuli of this process, only unfolded protein endoplasmic reticulum (ER) stress-mediated autophagy protects from cell death. Interestingly, select therapeutic agents (fludarabine, GS-1101, flavopiridol), which are active in CLL, also induce autophagy. Of interest, only the broad cyclin-dependent kinase inhibitor flavopiridol has improved efficacy when autophagy is antagonized biochemically (chloroquine) or by siRNA. This promoted an investigation which demonstrated unexpectedly that flavopiridol mediates ER stress and downstream activation of MAP3K5/ASK1, which ultimately is responsible for cell death. Similarly, autophagy activated in part via ER stress and also CDK5 inhibition is protective against cell death induced by this process. Collectively, our studies demonstrate that in CLL, autophagy is induced by multiple stimuli but only acts as a mechanism of resistance against ER stress-mediating agents. Similarly, flavopiridol mediates ER stress as a primary mechanism of action in CLL, and autophagy serves as a mechanism of resistance to this agent.

  10. ER stress and autophagy: new discoveries in the mechanism of action and drug resistance of the cyclin-dependent kinase inhibitor flavopiridol.

    Science.gov (United States)

    Mahoney, Emilia; Lucas, David M; Gupta, Sneha V; Wagner, Amy J; Herman, Sarah E M; Smith, Lisa L; Yeh, Yuh-Ying; Andritsos, Leslie; Jones, Jeffrey A; Flynn, Joseph M; Blum, Kristie A; Zhang, Xiaoli; Lehman, Amy; Kong, Hui; Gurcan, Metin; Grever, Michael R; Johnson, Amy J; Byrd, John C

    2012-08-09

    Cyclin dependent kinase (CDK) inhibitors, such as flavopiridol, demonstrate significant single-agent activity in chronic lymphocytic leukemia (CLL), but the mechanism of action in these nonproliferating cells is unclear. Here we demonstrate that CLL cells undergo autophagy after treatment with therapeutic agents, including fludarabine, CAL-101, and flavopiridol as well as the endoplasmic reticulum (ER) stress-inducing agent thapsigargin. The addition of chloroquine or siRNA against autophagy components enhanced the cytotoxic effects of flavopiridol and thapsigargin, but not the other agents. Similar to thapsigargin, flavopiridol robustly induces a distinct pattern of ER stress in CLL cells that contributes to cell death through IRE1-mediated activation of ASK1 and possibly downstream caspases. Both autophagy and ER stress were documented in tumor cells from CLL patients receiving flavopiridol. Thus, CLL cells undergo autophagy after multiple stimuli, including therapeutic agents, but only with ER stress mediators and CDK inhibitors is autophagy a mechanism of resistance to cell death. These findings collectively demonstrate, for the first time, a novel mechanism of action (ER stress) and drug resistance (autophagy) for CDK inhibitors, such as flavopiridol in CLL, and provide avenues for new therapeutic combination approaches in this disease.

  11. Astragaloside IV protects against podocyte injury via SERCA2-dependent ER stress reduction and AMPKα-regulated autophagy induction in streptozotocin-induced diabetic nephropathy.

    Science.gov (United States)

    Guo, Hengjiang; Wang, Yi; Zhang, Xuemei; Zang, Yingjun; Zhang, Yang; Wang, Li; Wang, Hao; Wang, Yunman; Cao, Aili; Peng, Wen

    2017-07-31

    Aberrant endoplasmic reticulum (ER) stress and autophagy are associated with diabetic nephropathy. Here we investigated the effect of astragaloside IV (AS-IV) on the progression of diabetic nephropathy (DN) and the underlying mechanism involving ER stress and autophagy in streptozotocin (STZ)-induced diabetic mice and high glucose (HG)-incubated podocytes. The diabetic mice developed progressive albuminuria and glomerulosclerosis within 8 weeks, which were significantly ameliorated by AS-IV treatment in a dose-dependent manner. Moreover, diabetes or HG-induced podocyte apoptosis was markedly attenuated by AS-IV, paralleled by a marked remission in ER stress and a remarkable restoration in impaired autophagy, which were associated with a significant improvement in the expression of sarcoendoplasmic reticulum Ca2+ ATPase 2b (SERCA2b) and AMP-activated protein kinase α (AMPKα) phosphorylation, respectively. Knockdown of SERCA2 in podocytes induced ER stress and largely abolished the protective effect of AS-IV, but had no obvious effect on the expression of autophagy-associated proteins. On the other hand, blockade of either autophagy induction or AMPKα activation could also significantly mitigate AS-IV-induced beneficial effect. Collectively, these results suggest that AS-IV prevented the progression of DN, which is mediated at least in part by SERCA2-dependent ER stress attenuation and AMPKα-promoted autophagy induction.

  12. Polyphenolic Extract of Euphorbia supina Attenuates Manganese-Induced Neurotoxicity by Enhancing Antioxidant Activity through Regulation of ER Stress and ER Stress-Mediated Apoptosis

    Directory of Open Access Journals (Sweden)

    Entaz Bahar

    2017-01-01

    Full Text Available Manganese (Mn is an important trace element present in human body, which acts as an enzyme co-factor or activator in various metabolic reactions. While essential in trace amounts, excess levels of Mn in human brain can produce neurotoxicity, including idiopathic Parkinson’s disease (PD-like extrapyramidal manganism symptoms. This study aimed to investigate the protective role of polyphenolic extract of Euphorbia supina (PPEES on Mn-induced neurotoxicity and the underlying mechanism in human neuroblastoma SKNMC cells and Sprague-Dawley (SD male rat brain. PPEES possessed significant amount of total phenolic and flavonoid contents. PPEES also showed significant antioxidant activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH radical scavenging and reducing power capacity (RPC assays. Our results showed that Mn treatment significantly reduced cell viability and increased lactate dehydrogenase (LDH level, which was attenuated by PPEES pretreatment at 100 and 200 µg/mL. Additionally, PPEES pretreatment markedly attenuated Mn-induced antioxidant status alteration by resolving the ROS, MDA and GSH levels and SOD and CAT activities. PPEES pretreatment also significantly attenuated Mn-induced mitochondrial membrane potential (ΔΨm and apoptosis. Meanwhile, PPEES pretreatment significantly reversed the Mn-induced alteration in the GRP78, GADD34, XBP-1, CHOP, Bcl-2, Bax and caspase-3 activities. Furthermore, administration of PPEES (100 and 200 mg/kg to Mn exposed rats showed improvement of histopathological alteration in comparison to Mn-treated rats. Moreover, administration of PPEES to Mn exposed rats showed significant reduction of 8-OHdG and Bax immunoreactivity. The results suggest that PPEES treatment reduces Mn-induced oxidative stress and neuronal cell loss in SKNMC cells and in the rat brain. Therefore, PPEES may be considered as potential treat-ment in Mn-intoxicated patients.

  13. Mcl-1 downregulation leads to the heightened sensitivity exhibited by BCR-ABL positive ALL to induction of energy and ER-stress.

    Science.gov (United States)

    Leclerc, Guy J; DeSalvo, Joanna; Du, Jianfeng; Gao, Ningguo; Leclerc, Gilles M; Lehrman, Mark A; Lampidis, Theodore J; Barredo, Julio C

    2015-08-20

    BCR-ABL positive (+) acute lymphoblastic leukemia (ALL) accounts for ∼30% of cases of ALL. We recently demonstrated that 2-deoxy-d-glucose (2-DG), a dual energy (glycolysis inhibition) and ER-stress (N-linked-glycosylation inhibition) inducer, leads to cell death in ALL via ER-stress/UPR-mediated apoptosis. Among ALL subtypes, BCR-ABL+ ALL cells exhibited the highest sensitivity to 2-DG suggesting BCR-ABL expression may be linked to this increased vulnerability. To confirm the role of BCR-ABL, we constructed a NALM6/BCR-ABL stable cell line and found significant increase in 2-DG-induced apoptosis compared to control. We found that Mcl-1 was downregulated by agents inducing ER-stress and Mcl-1 levels correlated with ALL sensitivity. In addition, we showed that Mcl-1 expression is positively regulated by the MEK/ERK pathway, dependent on BCR-ABL, and further downregulated by combining ER-stressors with TKIs. We determined that energy/ER stressors led to translational repression of Mcl-1 via the AMPK/mTOR and UPR/PERK/eIF2α pathways. Taken together, our data indicate that BCR-ABL+ ALL exhibits heightened sensitivity to induction of energy and ER-stress through inhibition of the MEK/ERK pathway, and translational repression of Mcl-1 expression via AMPK/mTOR and UPR/PERK/eIF2α pathways. This study supports further consideration of strategies combining energy/ER-stress inducers with BCR-ABL TKIs for future clinical translation in BCR-ABL+ ALL patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Role of Oxidative Stress in Modulating Unfolded Protein Response Activity in Chronic Myeloid Leukemia Cell Line.

    Science.gov (United States)

    Bazi, Ali; Keramati, Mohammad Reza; Gholamin, Mehran

    2016-01-01

    Recently, it has been revealed that tyrosine kinase inhibitors (TKIs) act through inducing both oxidative and endoplasmic reticulum (ER) stress in chronic myeloid leukemia cells. However, ER stress signaling triggers both apoptotic and survival processes within cells. Nevertheless, mechanisms by which TKIs avoid the pro-survival effects are not clear. The aim of this study was to evaluate the potential role of oxidative stress in activity of unfolded protein response (UPR) survival pathway within K562 cell line. The expression of UPR survival target genes, Xbp1, and Grp94 (glucose requiring protein 94) was studied in single and combined exposure to oxidative and ER stress in K562 cell line by quantitative and qualitative PCR. The expression of UPR-related survival gene Grp94 was hampered by exposing to oxidative stress in cell induced with ER stress. Interaction of oxidative and ER stress may role as a mediator influencing UPR signaling activity.

  15. Stress i børnefamilier: er børnene årsagen?

    DEFF Research Database (Denmark)

    Engell, Rikke; Nielsen, Naja Rod; Andersen, Anne-Marie Nybo

    2007-01-01

    Danish Health and Morbidity Survey 2000 were used. 3,083 men and 2,813 women aged 25-49 years answered one question on perceived stress. All analyses were stratified on sex and marital status and adjusted for age, socio-economic level, income and work hours/week. RESULTS: No differences in perceived......INTRODUCTION: Stress may affect health negatively. Therefore, it is important to identify risks factors for high levels of stress. Previous studies indicate that parents report higher levels of stress than adults without children. Whether this it due to having children or due to other circumstances...... is unknown. The purpose of this study is to investigate whether parents have higher levels of stress than adults without children after controlling for possible confounders. A possible interaction between being a parent and working time on perceived stress will be examined. METHODS: Cross-sectional data from...

  16. Time lapse imaging analysis of the effect of ER stress modulators on apoptotic cell assessed by caspase3/7 activation in NG108-15 cells

    Directory of Open Access Journals (Sweden)

    Ayako Saito

    2016-03-01

    Full Text Available This paper reports the data from the long term time lapse imaging of neuronal cell line NG108-15 that were treated with apoptosis inducer or various ER stress inducers. Use of the fluorescent reporter for activated caspase3/7 in combination with the conventional light microscope allowed us to investigate the time course of apoptosis induction at the single cell level. Quantitative as well as qualitative data are presented here to show the effect of two different ER stress modulating chemical compounds on caspase3/7-dependent apoptosis in neuronal cell line NG108-15 cells. Additional results and interpretation of our data concerning ER stress and apoptosis in NG108-15 cells can be found in Suga et al. (2015 [1] and in Suga et al. (2015 [2].

  17. Anti-Fibrotic Effect of Losartan, an Angiotensin II Receptor Blocker, Is Mediated through Inhibition of ER Stress via Up-Regulation of SIRT1, Followed by Induction of HO-1 and Thioredoxin.

    Science.gov (United States)

    Kim, Hyosang; Baek, Chung Hee; Lee, Raymond Bok; Chang, Jai Won; Yang, Won Seok; Lee, Sang Koo

    2017-01-31

    Endoplasmic reticulum (ER) stress is increasingly identified as modulator of fibrosis. Losartan, an angiotensin II receptor blocker, has been widely used as the first choice of treatment in chronic renal diseases. We postulated that anti-fibrotic effect of losartan is mediated through inhibition of ER stress via SIRT1 (silent mating type information regulation 2 homolog 1) hemeoxygenase-1 (HO-1)/thioredoxin pathway. Renal tubular cells, tunicamycin (TM)-induced ER stress, and unilateral ureteral obstruction (UUO) mouse model were used. Expression of ER stress was assessed by Western blot analysis and immunohistochemical stain. ER stress was induced by chemical ER stress inducer, tunicamycin, and non-chemical inducers such as TGF-β, angiotensin II, high glucose, and albumin. Losartan suppressed the TM-induced ER stress, as shown by inhibition of TM-induced expression of GRP78 (glucose related protein 78) and p-eIF2α (phosphospecific-eukaryotic translation initiation factor-2α), through up-regulation of SIRT1 via HO-1 and thioredoxin. Losartan also suppressed the ER stress by non-chemical inducers. In both animal models, losartan reduced the tubular expression of GRP78, which were abolished by pretreatment with sirtinol (SIRT1 inhibitor). Sirtinol also blocked the inhibitory effect of losartan on the UUO-induced renal fibrosis. These findings provide new insights into renoprotective effects of losartan and suggest that SIRT1, HO-1, and thioredoxin may be potential pharmacological targets in kidney diseases under excessive ER stress condition.

  18. Ubiquitin fold modifier 1 (UFM1 and its target UFBP1 protect pancreatic beta cells from ER stress-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Katleen Lemaire

    Full Text Available UFM1 is a member of the ubiquitin like protein family. While the enzymatic cascade of UFM1 conjugation has been elucidated in recent years, the biological function remains largely unknown. In this report we demonstrate that the recently identified C20orf116, which we name UFM1-binding protein 1 containing a PCI domain (UFBP1, and CDK5RAP3 interact with UFM1. Components of the UFM1 conjugation pathway (UFM1, UFBP1, UFL1 and CDK5RAP3 are highly expressed in pancreatic islets of Langerhans and some other secretory tissues. Co-localization of UFM1 with UFBP1 in the endoplasmic reticulum (ER depends on UFBP1. We demonstrate that ER stress, which is common in secretory cells, induces expression of Ufm1, Ufbp1 and Ufl1 in the beta-cell line INS-1E. siRNA-mediated Ufm1 or Ufbp1 knockdown enhances apoptosis upon ER stress. Silencing the E3 enzyme UFL1, results in similar outcomes, suggesting that UFM1-UFBP1 conjugation is required to prevent ER stress-induced apoptosis. Together, our data suggest that UFM1-UFBP1 participate in preventing ER stress-induced apoptosis in protein secretory cells.

  19. Simulation of thermal stress in Er2O3 and Al2O3 tritium penetration barriers by finite-element analysis

    Science.gov (United States)

    Liu, Ze; Wang, Yuan; Yu, Guogang; He, Anping; Wang, Ling

    2017-09-01

    The physical vapor deposition method is an effective way to deposit Al2O3 and Er2O3 on 316L stainless steel substrates acting as tritium permeation barriers in a fusion reactor. The distribution of residual thermal stress is calculated both in Al2O3 and Er2O3 coating systems with planar and rough substrates using finite element analysis. The parameters influencing the thermal stress in the sputter process are analyzed, such as coating and substrate properties, temperature and Young’s modulus. This work shows that the thermal stress in Al2O3 and Er2O3 coating systems exhibit a linear relationship with substrate thickness, temperature and Young’s modulus. However, this relationship is inversed with coating thickness. In addition, the rough substrate surface can increase the thermal stress in the process of coating deposition. The adhesive strength between the coating and the substrate is evaluated by the shear stress. Due to the higher compressive shear stress, the Al2O3 coating has a better adhesive strength with a 316L stainless steel substrate than the Er2O3 coating. Furthermore, the analysis shows that it is a useful way to improve adhesive strength with increasing interface roughness.

  20. The Orphan Nuclear Receptor NR4A1 Protects Pancreatic β-Cells from Endoplasmic Reticulum (ER) Stress-mediated Apoptosis.

    Science.gov (United States)

    Yu, Cong; Cui, Shang; Zong, Chen; Gao, Weina; Xu, Tongfu; Gao, Peng; Chen, Jicui; Qin, Dandan; Guan, Qingbo; Liu, Yuantao; Fu, Yuchang; Li, Xia; Wang, Xiangdong

    2015-08-21

    The role of NR4A1 in apoptosis is controversial. Pancreatic β-cells often face endoplasmic reticulum (ER) stress under adverse conditions such as high free fatty acid (FFA) concentrations and sustained hyperglycemia. Severe ER stress results in β-cell apoptosis. The aim of this study was to analyze the role of NR4A1 in ER stress-mediated β-cell apoptosis and to characterize the related mechanisms. We confirmed that upon treatment with the ER stress inducers thapsigargin (TG) or palmitic acid (PA), the mRNA and protein levels of NR4A1 rapidly increased in both MIN6 cells and mouse islets. NR4A1 overexpression in MIN6 cells conferred resistance to cell loss induced by TG or PA, as assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and TUNEL assays indicated that NR4A1 overexpression also protected against ER stress-induced apoptosis. This conclusion was further confirmed by experiments exploiting siRNA to knockdown NR4A1 expression in MIN6 cells or exploiting NR4A1 knock-out mice. NR4A1 overexpression in MIN6 cells reduced C/EBP homologous protein (CHOP) expression and Caspase3 activation induced by TG or PA. NR4A1 overexpression in MIN6 cells or mouse islets resulted in Survivin up-regulation. A critical regulatory element was identified in Survivin promoter (-1872 bp to -1866 bp) with a putative NR4A1 binding site; ChIP assays demonstrated that NR4A1 physically associates with the Survivin promoter. In conclusion, NR4A1 protects pancreatic β-cells against ER stress-mediated apoptosis by up-regulating Survivin expression and down-regulating CHOP expression, which we termed as "positive and negative regulation." © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. New mechanism of lipotoxicity in diabetic cardiomyopathy: Deficiency of Endogenous H2S Production and ER stress.

    Science.gov (United States)

    Guo, Runmin; Wu, Zijun; Jiang, Jiamei; Liu, Chang; Wu, Bin; Li, Xingyue; Li, Teng; Mo, Hailiang; He, Songjian; Li, Shanghai; Yan, Hai; Huang, Ruina; You, Qiong; Wu, Keng

    2017-03-01

    To investigate the roles and mechanisms of endogenous hydrogen sulfide (H2S) and endoplasmic reticulum (ER) stress in the development of diabetic cardiomyopathy (DCM). Blood of DCM patients included in the study were collected. The model of DCM rats was established using streptozotocin (STZ) injection. Cardiac lipotoxicity in vitro models were established using 500μM palmitic acid (PA) treatment for 24h in AC16 cardiomyocytes. Endogenous H2S production in plasma, culture supernatant and heart was measured by sulphur ion-selective electrode assay. Cell viability was tested by using the cell counting kit-8 (CCK-8) kit. Glucose regulated protein (GRP78), CCAAT/enhancer binding protein homologous transcription factor (C/EBP) homologous protein (CHOP), caspase-3 and caspase-12 expressions were measured using western blot analysis. Lipid droplet was evaluated by Oil Red O staining. Apoptosis in hearts of DCM rats was analyzed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. H2S levels in serum of DCM patients and DCM rats were significant lower, H2S contents and cystathionine-γ-lyase (CSE) expression in heart tissues of DCM rats were also markedly lower. H2S levels in supernatants of PA-treated AC16 cardiac cells were decreased. Cardiac lipotoxicity demonstrated by increase in TUNEL positive cells and lipid deposit in vivo and in vitro accompanied by a decrease of H2S levels. Pretreatment AC16 cells with 100μmol/L of NaHS (a donor of H2S) could suppress the PA-induced myocardial injury similar to the effects of 4-phenylbutyric acid (4-PBA, an endoplasmic reticulum (ER) stress inhibitor), leading to an increase in cell viability and preventing lipid deposit. Meanwhile, administration diabetic rats with NaHS or 4-PBA alleviated cardiac lipotoxicity, as evidenced by decrease in TUNEL positive cells, cleaved caspase-3 expression and lipid accumulation. Deficiency of endogenous H2S was involved in lipotoxicity-induced myocardial injury

  2. Free fatty acids induce ER stress and block antiviral activity of interferon alpha against hepatitis C virus in cell culture

    Directory of Open Access Journals (Sweden)

    Gunduz Feyza

    2012-08-01

    Full Text Available Abstract Background Hepatic steatosis is recognized as a major risk factor for liver disease progression and impaired response to interferon based therapy in chronic hepatitis C (CHC patients. The mechanism of response to interferon-alpha (IFN-α therapy under the condition of hepatic steatosis is unexplored. We investigated the effect of hepatocellular steatosis on hepatitis C virus (HCV replication and IFN-α antiviral response in a cell culture model. Methods Sub-genomic replicon (S3-GFP and HCV infected Huh-7.5 cells were cultured with a mixture of saturated (palmitate and unsaturated (oleate long-chain free fatty acids (FFA. Intracytoplasmic fat accumulation in these cells was visualized by Nile red staining and electron microscopy then quantified by microfluorometry. The effect of FFA treatment on HCV replication and IFN-α antiviral response was measured by flow cytometric analysis, Renilla luciferase activity, and real-time RT-PCR. Results FFA treatment induced dose dependent hepatocellular steatosis and lipid droplet accumulation in the HCV replicon cells was confirmed by Nile red staining, microfluorometry, and by electron microscopy. Intracellular fat accumulation supports replication more in the persistently HCV infected culture than in the sub-genomic replicon (S3-GFP cell line. FFA treatment also partially blocked IFN-α response and viral clearance by reducing the phosphorylation of Stat1 and Stat2 dependent IFN-β promoter activation. We show that FFA treatment induces endoplasmic reticulum (ER stress response and down regulates the IFNAR1 chain of the type I IFN receptor leading to defective Jak-Stat signaling and impaired antiviral response. Conclusion These results suggest that intracellular fat accumulation in HCV cell culture induces ER stress, defective Jak-Stat signaling, and attenuates the antiviral response, thus providing an explanation to the clinical observation regarding how hepatocellular steatosis influences IFN

  3. Secretion of novel SEL1L endogenous variants is promoted by ER stress/UPR via endosomes and shed vesicles in human cancer cells.

    Directory of Open Access Journals (Sweden)

    Monica Cattaneo

    Full Text Available We describe here two novel endogenous variants of the human endoplasmic reticulum (ER cargo receptor SEL1LA, designated p38 and p28. Biochemical and RNA interference studies in tumorigenic and non-tumorigenic cells indicate that p38 and p28 are N-terminal, ER-anchorless and more stable relative to the canonical transmembrane SEL1LA. P38 is expressed and constitutively secreted, with increase after ER stress, in the KMS11 myeloma line and in the breast cancer lines MCF7 and SKBr3, but not in the non-tumorigenic breast epithelial MCF10A line. P28 is detected only in the poorly differentiated SKBr3 cell line, where it is secreted after ER stress. Consistently with the presence of p38 and p28 in culture media, morphological studies of SKBr3 and KMS11 cells detect N-terminal SEL1L immunolabeling in secretory/degradative compartments and extracellularly-released membrane vesicles. Our findings suggest that the two new SEL1L variants are engaged in endosomal trafficking and secretion via vesicles, which could contribute to relieve ER stress in tumorigenic cells. P38 and p28 could therefore be relevant as diagnostic markers and/or therapeutic targets in cancer.

  4. XBP1-Independent UPR Pathways Suppress C/EBP-β Mediated Chondrocyte Differentiation in ER-Stress Related Skeletal Disease.

    Directory of Open Access Journals (Sweden)

    Trevor L Cameron

    2015-09-01

    Full Text Available Schmid metaphyseal chondrodysplasia (MCDS involves dwarfism and growth plate cartilage hypertrophic zone expansion resulting from dominant mutations in the hypertrophic zone collagen, Col10a1. Mouse models phenocopying MCDS through the expression of an exogenous misfolding protein in the endoplasmic reticulum (ER in hypertrophic chondrocytes have demonstrated the central importance of ER stress in the pathology of MCDS. The resultant unfolded protein response (UPR in affected chondrocytes involved activation of canonical ER stress sensors, IRE1, ATF6, and PERK with the downstream effect of disrupted chondrocyte differentiation. Here, we investigated the role of the highly conserved IRE1/XBP1 pathway in the pathology of MCDS. Mice with a MCDS collagen X p.N617K knock-in mutation (ColXN617K were crossed with mice in which Xbp1 was inactivated specifically in cartilage (Xbp1CartΔEx2, generating the compound mutant, C/X. The severity of dwarfism and hypertrophic zone expansion in C/X did not differ significantly from ColXN617K, revealing surprising redundancy for the IRE1/XBP1 UPR pathway in the pathology of MCDS. Transcriptomic analyses of hypertrophic zone cartilage identified differentially expressed gene cohorts in MCDS that are pathologically relevant (XBP1-independent or pathologically redundant (XBP1-dependent. XBP1-independent gene expression changes included large-scale transcriptional attenuation of genes encoding secreted proteins and disrupted differentiation from proliferative to hypertrophic chondrocytes. Moreover, these changes were consistent with disruption of C/EBP-β, a master regulator of chondrocyte differentiation, by CHOP, a transcription factor downstream of PERK that inhibits C/EBP proteins, and down-regulation of C/EBP-β transcriptional co-factors, GADD45-β and RUNX2. Thus we propose that the pathology of MCDS is underpinned by XBP1 independent UPR-induced dysregulation of C/EBP-β-mediated chondrocyte differentiation

  5. Tuned to survive: Salt stress induced changes in Arabidopsis

    NARCIS (Netherlands)

    Jułkowska, M.M.

    2015-01-01

    Plants are flexible organisms, with the potential to develop a plethora of morphological variants depending on the growth conditions to which they are exposed. This morphological flexibility enabled plants to colonize almost every corner of the globe and to survive in the harshest conditions. Our

  6. Development of a fluorescent reporter system for monitoring ER stress in Chinese hamster ovary cells and its application for therapeutic protein production.

    Directory of Open Access Journals (Sweden)

    Gargi Roy

    Full Text Available Mammalian cell expression systems have become a workhorse for the production of biotherapeutic proteins. As such, there is an ever increasing demand for higher productivity from these expression platforms to reduce manufacturing costs. While great advances have been made in the optimization of culture conditions and cell line selection to improve productivity, protein mis-folding remains a common limitation to high levels of production of therapeutic proteins. Accumulation of mis- and unfolded protein in the endoplasmic reticulum (ER causes ER stress and initiates the unfolded protein response (UPR that results in an activation of protein folding machinery, translation attenuation in an effort to proper folding of the newly synthesized peptides or may even lead to apoptosis if the correct folding is not restored. As a result, UPR associated apoptosis often results in lower protein expression. To better understand the molecular mechanisms in these pathways, we developed a reporter construct that detects Inositol-requiring enzyme 1 (IRE1-alpha mediated splicing of X-box binding protein 1 (XBP1 to monitor the course of UPR activation in cell lines expressing monoclonal antibodies. Using this reporter we observed a clear activation of UPR in cells treated with known ER stress causing pharmacological agents, such as Tunicamycin (Tm and Thapsigargin (Tg, as well as in stable IgG expressing cells during fed-batch cultures. Furthermore, we developed a stress metric that we term as ER stress index (ERSI to gauge basal ER stress in cells which we used as a predictive tool for isolation of high IgG expressing cell lines. This reporter system, with its ability to monitor the stress involved in recombinant protein expression, has utility to assist in devising engineering strategies for improved production of biotherapeutic drugs.

  7. Up-regulation of K{sub ir}2.1 by ER stress facilitates cell death of brain capillary endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Kito, Hiroaki [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Yamazaki, Daiju [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Department of Biological Chemistry, Kyoto University, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Ohya, Susumu; Yamamura, Hisao [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Asai, Kiyofumi [Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Imaizumi, Yuji, E-mail: yimaizum@phar.nagoya-cu.ac.jp [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan)

    2011-07-29

    Highlights: {yields} We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. {yields} The ER stress facilitated the expression of inward rectifier K{sup +} channel (K{sub ir}2.1) and induced sustained membrane hyperpolarization. {yields} The membrane hyperpolarization induced sustained Ca{sup 2+} entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. {yields} The K{sub ir}2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K{sup +} channel (K{sub ir}2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K{sub ir} channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca{sup 2+} concentration due to Ca{sup 2+} influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K{sub ir}2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

  8. Ultraviolet (UV) and Hydrogen Peroxide Activate Ceramide-ER Stress-AMPK Signaling Axis to Promote Retinal Pigment Epithelium (RPE) Cell Apoptosis

    Science.gov (United States)

    Yao, Jin; Bi, Hui-E; Sheng, Yi; Cheng, Li-Bo; Wendu, Ri-Le; Wang, Cheng-Hu; Cao, Guo-Fan; Jiang, Qin

    2013-01-01

    Ultraviolet (UV) radiation and reactive oxygen species (ROS) impair the physiological functions of retinal pigment epithelium (RPE) cells by inducing cell apoptosis, which is the main cause of age-related macular degeneration (AMD). The mechanism by which UV/ROS induces RPE cell death is not fully addressed. Here, we observed the activation of a ceramide-endoplasmic reticulum (ER) stress-AMP activated protein kinase (AMPK) signaling axis in UV and hydrogen peroxide (H2O2)-treated RPE cells. UV and H2O2 induced an early ceramide production, profound ER stress and AMPK activation. Pharmacological inhibitors against ER stress (salubrinal), ceramide production (fumonisin B1) and AMPK activation (compound C) suppressed UV- and H2O2-induced RPE cell apoptosis. Conversely, cell permeable short-chain C6 ceramide and AMPK activator AICAR (5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide) mimicked UV and H2O2’s effects and promoted RPE cell apoptosis. Together, these results suggest that UV/H2O2 activates the ceramide-ER stress-AMPK signaling axis to promote RPE cell apoptosis. PMID:23685869

  9. Synergistic Effects of Cilostazol and Probucol on ER Stress-Induced Hepatic Steatosis via Heme Oxygenase-1-Dependent Activation of Mitochondrial Biogenesis

    Directory of Open Access Journals (Sweden)

    Yingqing Chen

    2016-01-01

    Full Text Available The selective type-3 phosphodiesterase inhibitor cilostazol and the antihyperlipidemic agent probucol have antioxidative, anti-inflammatory, and antiatherogenic properties. Moreover, cilostazol and probucol can regulate mitochondrial biogenesis. However, the combinatorial effect of cilostazol and probucol on mitochondrial biogenesis remains unknown. Endoplasmic reticulum (ER stress is a well-known causative factor of nonalcoholic fatty liver disease (NAFLD which can impair mitochondrial function in hepatocytes. Here, we investigated the synergistic effects of cilostazol and probucol on mitochondrial biogenesis and ER stress-induced hepatic steatosis. A synergistic effect of cilostazol and probucol on HO-1 and mitochondrial biogenesis gene expression was found in human hepatocellular carcinoma cells (HepG2 and murine primary hepatocytes. Furthermore, in an animal model of ER stress involving tunicamycin, combinatorial treatment with cilostazol and probucol significantly increased the expression of HO-1 and mitochondrial biogenesis-related genes and proteins, whereas it downregulated serum ALT, eIF2 phosphorylation, and CHOP expression, as well as the lipogenesis-related genes SREBP-1c and FAS. Based on these results, we conclude that cilostazol and probucol exhibit a synergistic effect on the activation of mitochondrial biogenesis via upregulation of HO-1, which confers protection against ER stress-induced hepatic steatosis.

  10. Ultraviolet (UV and Hydrogen Peroxide Activate Ceramide-ER Stress-AMPK Signaling Axis to Promote Retinal Pigment Epithelium (RPE Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Jin Yao

    2013-05-01

    Full Text Available Ultraviolet (UV radiation and reactive oxygen species (ROS impair the physiological functions of retinal pigment epithelium (RPE cells by inducing cell apoptosis, which is the main cause of age-related macular degeneration (AMD. The mechanism by which UV/ROS induces RPE cell death is not fully addressed. Here, we observed the activation of a ceramide-endoplasmic reticulum (ER stress-AMP activated protein kinase (AMPK signaling axis in UV and hydrogen peroxide (H2O2-treated RPE cells. UV and H2O2 induced an early ceramide production, profound ER stress and AMPK activation. Pharmacological inhibitors against ER stress (salubrinal, ceramide production (fumonisin B1 and AMPK activation (compound C suppressed UV- and H2O2-induced RPE cell apoptosis. Conversely, cell permeable short-chain C6 ceramide and AMPK activator AICAR (5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide mimicked UV and H2O2’s effects and promoted RPE cell apoptosis. Together, these results suggest that UV/H2O2 activates the ceramide-ER stress-AMPK signaling axis to promote RPE cell apoptosis.

  11. Effect of environmental stress factors on the uptake and survival of Campylobacter jejuni in Acanthamoeba castellanii

    Directory of Open Access Journals (Sweden)

    Bui Xuan

    2012-10-01

    Full Text Available Abstract Background Campylobacter jejuni is a major cause of bacterial food-borne illness in Europe and North America. The mechanisms allowing survival in the environment and transmission to new hosts are not well understood. Environmental free-living protozoa may facilitate both processes. Pre-exposure to heat, starvation, oxidative or osmotic stresses encountered in the environment may affect the subsequent interaction of C. jejuni with free-living protozoa. To test this hypothesis, we examined the impact of environmental stress on expression of virulence-associated genes (ciaB, dnaJ, and htrA of C. jejuni and on its uptake by and intracellular survival within Acanthamoeba castellanii. Results Heat, starvation and osmotic stress reduced the survival of C. jejuni significantly, whereas oxidative stress had no effect. Quantitative RT-PCR experiments showed that the transcription of virulence genes was slightly up-regulated under heat and oxidative stresses but down-regulated under starvation and osmotic stresses, the htrA gene showing the largest down-regulation in response to osmotic stress. Pre-exposure of bacteria to low nutrient or osmotic stress reduced bacterial uptake by amoeba, but no effect of heat or oxidative stress was observed. Finally, C. jejuni rapidly lost viability within amoeba cells and pre-exposure to oxidative stress had no significant effect on intracellular survival. However, the numbers of intracellular bacteria recovered 5 h post-gentamicin treatment were lower with starved, heat treated or osmotically stressed bacteria than with control bacteria. Also, while ~1.5 × 103 colony forming unit/ml internalized bacteria could typically be recovered 24 h post-gentamicin treatment with control bacteria, no starved, heat treated or osmotically stressed bacteria could be recovered at this time point. Overall, pre-exposure of C. jejuni to environmental stresses did not promote intracellular survival in A. castellanii

  12. Survival under stress: molecular mechanisms of metabolic rate ...

    African Journals Online (AJOL)

    Studies in my laboratory are analysing the molecular mechanisms and regulatory events that underlie transitions to and from hypometabolic states In systems including ... Our newest research targets two areas: the role of protein kinases in regulating metabolic adjustments and the role of stress-induced gene expression in ...

  13. Involvement of ER Stress in Dysmyelination of Pelizaeus-Merzbacher Disease with PLP1 Missense Mutations Shown by iPSC-Derived Oligodendrocytes

    Directory of Open Access Journals (Sweden)

    Yuko Numasawa-Kuroiwa

    2014-05-01

    Full Text Available Pelizaeus-Merzbacher disease (PMD is a form of X-linked leukodystrophy caused by mutations in the proteolipid protein 1 (PLP1 gene. Although PLP1 proteins with missense mutations have been shown to accumulate in the rough endoplasmic reticulum (ER in disease model animals and cell lines transfected with mutant PLP1 genes, the exact pathogenetic mechanism of PMD has not previously been clarified. In this study, we established induced pluripotent stem cells (iPSCs from two PMD patients carrying missense mutation and differentiated them into oligodendrocytes in vitro. In the PMD iPSC-derived oligodendrocytes, mislocalization of mutant PLP1 proteins to the ER and an association between increased susceptibility to ER stress and increased numbers of apoptotic oligodendrocytes were observed. Moreover, electron microscopic analysis demonstrated drastically reduced myelin formation accompanied by abnormal ER morphology. Thus, this study demonstrates the involvement of ER stress in pathogenic dysmyelination in the oligodendrocytes of PMD patients with the PLP1 missense mutation.

  14. Eeyarestatin causes cervical cancer cell sensitization to bortezomib treatment by augmenting ER stress and CHOP expression.

    Science.gov (United States)

    Brem, German J; Mylonas, Ioannis; Brüning, Ansgar

    2013-02-01

    The proteasome inhibitor bortezomib is currently being tested in clinical trials against refractory cervical cancer. However, high doses of bortezomib are associated with adverse effects, which may lead to treatment abrogation or to the use of lower, ineffective doses. We investigated combination drug treatments that could enhance the efficacy of low bortezomib concentrations on cervical cancer cells. The cervical cancer cell lines CaSki, HeLa and SW756 were treated with various combinations of bortezomib and eeyarestatin. Treated cells were analyzed for cell viability by clonal assays and the MTT assay, and for expression of pro-apoptotic proteins and cell stress markers by immunofluorescence, immunoblots and RT-PCR analysis. Cotreatment of bortezomib with eeyarestatin markedly enhanced cell death in cervical cancer cells, allowing reduction of the bortezomib concentration necessary for efficient cell death to as low as 5 ng/ml. Combination of bortezomib with eeyarestatin resulted in a massive induction of the endoplasmic reticulum stress reaction, small and large heat shock protein activation, autophagy, and upregulation of pro-apoptotic CHOP. Eeyarestatin is a small molecule recently shown to cause endoplasmic reticulum stress by inhibiting the endoplasmic reticulum-associated degradation pathway, which directs misfolded cytotoxic proteins to proteasomal degradation. Concomitant inhibition of both pathways markedly enhances the efficacy of bortezomib against cervical cancer cells and thus may be applied to reduce the bortezomib dosage required for efficient cervical cancer treatment. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Molecular mechanism of ER stress-induced gene expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in macrophages.

    Science.gov (United States)

    Huang, Yan; Wang, Yarui; Li, Xiaofeng; Chen, Zhaolin; Li, Xiaohui; Wang, Huan; Ni, Mingming; Li, Jun

    2015-06-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor superfamily, whose members are capable of inducing apoptosis and inflammation. Endoplasmic reticulum stress (ERS) plays a key role in immune surveillance in macrophages. TRAIL mRNA and protein expression have previously been detected in macrophages; however, whether ERS has any effects on TRAIL expression in macrophages has not yet been determined. Here, we demonstrate that thapsigargin (TG) and tunicamycin (TM), two ERS inducers activated macrophages were able to increase TRAIL mRNA and protein expression in RAW264.7 macrophages, the culture supernatant of THP-1 cells, and mouse peritoneal macrophages, indicating that ERS as a potent inducer of TRAIL transcription and expression in macrophages. This effect was blocked by the specific JNK inhibitor SP600125 and transcription factor AP-1 inhibitor SR 1130. Interestingly, at the molecular level, regulation of TRAIL expression by ERS was accompanied by a significant decrease in cytokine signaling suppressor 3 (SOCS3). SOCS3 siRNA clearly increased the expression of TRAIL mRNA and protein under ERS by activating the AP-1 components phosphorylated c-Jun and phosphorylated c-Fos in RAW264.7 cells. In contrast, over-expression of SOCS3 reversed ERS-induced TRAIL expression. These findings provide in vitro evidence that SOCS3 plays a critical negative role in the regulation of ERS-induced TRAIL expression via the Jun N-terminal kinase/AP-1 signaling pathway in macrophages. © 2015 FEBS.

  16. Periodontal disease level-butyric acid amounts locally administered in the rat gingival mucosa induce ER stress in the systemic blood.

    Science.gov (United States)

    Cueno, Marni E; Saito, Yuko; Ochiai, Kuniyasu

    2016-05-01

    Periodontal diseases have long been postulated to contribute to systemic diseases and, likewise, it has been proposed that periodontal disease treatment may ameliorate certain systemic diseases. Short-chain fatty acids (SCFA) are major secondary metabolites produced by oral anaerobic bacteria and, among the SCFAs, butyric acid (BA) in high amounts contribute to periodontal disease development. Periodontal disease level-butyric acid (PDL-BA) is found among patients suffering from periodontal disease and has previously shown to induce oxidative stress, whereas, oxidative stress is correlated to endoplasmic reticulum (ER) stress. This would imply that PDL-BA may likewise stimulate ER stress, however, this was never elucidated. A better understanding of the correlation between PDL-BA and systemic ER stress stimulation could shed light on the possible systemic effects of PDL-BA-related periodontal diseases. Here, PDL-BA was injected into the gingival mucosa and the systemic blood obtained from the rat jugular was collected at 0, 15, 60, and 180 min post-injection. Collected blood samples were purified and only the blood cytosol was used throughout this study. Subsequently, we measured blood cytosolic GADD153, Ca(2+), representative apoptotic and inflammatory caspases, and NF-κB amounts. We found that PDL-BA presence increased blood cytosolic GADD153 and Ca(2+) amounts. Moreover, we observed that blood cytosolic caspases and NF-κB were activated only at 60 and 180 min post-injection in the rat gingival mucosa. This suggests that PDL-BA administered through the gingival mucosa may influence the systemic blood via ER stress stimulation and, moreover, prolonged PDL-BA retention in the gingival mucosa may play a significant role in ER stress-related caspase and NF-κB activation. In a periodontal disease scenario, we propose that PDL-BA-related ER stress stimulation leading to the simultaneous activation of apoptosis and inflammation may contribute to periodontal disease

  17. Fluoride Intensifies Hypercaloric Diet-Induced ER Oxidative Stress and Alters Lipid Metabolism.

    Directory of Open Access Journals (Sweden)

    Heloisa Aparecida Barbosa Silva Pereira

    Full Text Available Here, we evaluated the relationship of diet and F-induced oxidative stress to lipid metabolism in the liver of rats eating normocaloric or hypercaloric diets for two time periods (20 or 60 days.Seventy-two 21-day-old Wistar rats were divided into 2 groups (n = 36 based on the type of diet they were eating; each of these groups was then further divided into another two groups (n = 18 based on the time periods of either 20 or 60 days, for a total of four groups. Each of these was divided into 3 subgroups (n = 6 animals/subgroup, dependent on the dose of F administered in the drinking water (0 mg/L(control, 15 mg/L or 50 mg/L. After the experimental period, blood samples and the liver were collected. Plasma samples were analyzed for HDL, cholesterol and triglycerides. Western blots were performed to probe for GRP78, Erp29, SOD2, Apo-E and SREBP in hepatic tissues.As expected,the expression of target proteins involved in oxidative stress increased in the F-treated groups, especially in liver tissue obtained from animals eating a hypercaloric diet. Most changes in the lipid levels and pathological conditions were seen earlier in the time period, at day 20. The morphometric analyses showed a reduction in steatosis in groups on ahypercaloric diet and treated with 50 mg F/L compared to the control, while no changes were obtained in normocaloric-fed rats. Accordingly, plasma TG was reduced in the F-treated group. The reduced expression of Apo-E in a time- and diet-dependent pattern may account for the particular decrease in steatosis in hypercaloric-fed F-treated rats.These results suggest that F changes liver lipid homeostasis, possibly because of the induction of oxidative stress, which seems to be higher in animals fed hypercaloric diets.

  18. ER stress-mediated apoptosis in a new mouse model of osteogenesis imperfecta.

    Directory of Open Access Journals (Sweden)

    Thomas S Lisse

    2008-02-01

    Full Text Available Osteogenesis imperfecta is an inherited disorder characterized by increased bone fragility, fractures, and osteoporosis, and most cases are caused by mutations affecting the type I collagen genes. Here, we describe a new mouse model for Osteogenesis imperfecta termed Aga2 (abnormal gait 2 that was isolated from the Munich N-ethyl-N-nitrosourea mutagenesis program and exhibited phenotypic variability, including reduced bone mass, multiple fractures, and early lethality. The causal gene was mapped to Chromosome 11 by linkage analysis, and a C-terminal frameshift mutation was identified in the Col1a1 (procollagen type I, alpha 1 gene as the cause of the disorder. Aga2 heterozygous animals had markedly increased bone turnover and a disrupted native collagen network. Further studies showed that abnormal proalpha1(I chains accumulated intracellularly in Aga2/+ dermal fibroblasts and were poorly secreted extracellularly. This was associated with the induction of an endoplasmic reticulum stress-specific unfolded protein response involving upregulation of BiP, Hsp47, and Gadd153 with caspases-12 and -3 activation and apoptosis of osteoblasts both in vitro and in vivo. These studies resulted in the identification of a new model for Osteogenesis imperfecta, and identified a role for intracellular modulation of the endoplasmic reticulum stress-associated unfolded protein response machinery toward osteoblast apoptosis during the pathogenesis of disease.

  19. Inflammation and ER Stress Regulate Branched-Chain Amino Acid Uptake and Metabolism in Adipocytes

    Science.gov (United States)

    Burrill, Joel S.; Long, Eric K.; Reilly, Brian; Deng, Yingfeng; Armitage, Ian M.; Scherer, Philipp E.

    2015-01-01

    Inflammation plays a critical role in the pathology of obesity-linked insulin resistance and is mechanistically linked to the effects of macrophage-derived cytokines on adipocyte energy metabolism, particularly that of the mitochondrial branched-chain amino acid (BCAA) and tricarboxylic acid (TCA) pathways. To address the role of inflammation on energy metabolism in adipocytes, we used high fat-fed C57BL/6J mice and lean controls and measured the down-regulation of genes linked to BCAA and TCA cycle metabolism selectively in visceral but not in subcutaneous adipose tissue, brown fat, liver, or muscle. Using 3T3-L1 cells, TNFα, and other proinflammatory cytokine treatments reduced the expression of the genes linked to BCAA transport and oxidation. Consistent with this, [14C]-leucine uptake and conversion to triglycerides was markedly attenuated in TNFα-treated adipocytes, whereas the conversion to protein was relatively unaffected. Because inflammatory cytokines lead to the induction of endoplasmic reticulum stress, we evaluated the effects of tunicamycin or thapsigargin treatment of 3T3-L1 cells and measured a similar down-regulation in the BCAA/TCA cycle pathway. Moreover, transgenic mice overexpressing X-box binding protein 1 in adipocytes similarly down-regulated genes of BCAA and TCA metabolism in vivo. These results indicate that inflammation and endoplasmic reticulum stress attenuate lipogenesis in visceral adipose depots by down-regulating the BCAA/TCA metabolism pathway and are consistent with a model whereby the accumulation of serum BCAA in the obese insulin-resistant state is linked to adipose inflammation. PMID:25635940

  20. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  1. Impact of nutritional stress on early embryonic survival

    Directory of Open Access Journals (Sweden)

    Sukanta Mondal

    2015-09-01

    Full Text Available Background: Low reproductive efficiency is the most critical problem faced by the livestock industry across the globe. Early embryonic loss is one the major cause of poor reproductive efficiency resulting in delayed pregnancy, fewer calves born, reduced milk production, slower genetic progress and substantial financial loss to the beef or dairy industry. The establishment of pregnancy results from the interaction between the embryo and the dam and is the culmination of a series of events initiated with development of the follicle and gametes. Among numerous internal and external factors nutrition has the potency to alter the micro-environment of the oocyte and the embryo, making it more hostile to optimal fertilization and pre-implantation embryonic growth. Understanding the impact of nutritional stress on oocyte function, embryo development and reciprocal signaling networks between the embryo and uterus will lead to alleviation of the problems of early embryonic mortality.

  2. A Copper Chelate of Thiosemicarbazone NSC 689534 induces Oxidative/ER Stress and Inhibits Tumor Growth In Vitro and In Vivo

    Science.gov (United States)

    Hancock, Chad N.; Stockwin, Luke H.; Han, Bingnan; Divelbiss, Raymond D.; Jun, Jung Ho; Malhotra, Sanjay V.; Hollingshead, Melinda G.; Newton, Dianne L.

    2010-01-01

    In this study, a Cu2+ chelate of the novel thiosemicarbazone NSC 689534 was evaluated for in vitro and in vivo anti-cancer activity. Results demonstrated that NSC 689534 activity (low µM range) was enhanced 4–5 fold by copper chelation and completely attenuated by iron. Importantly, once formed, the NSC 689534/Cu2+ complex retained activity in the presence of additional iron or iron-containing biomolecules. NSC 689534/Cu2+ mediated its effects primarily through the induction of ROS, with depletion of cellular glutathione and protein thiols. Pre-treatment of cells with the antioxidant L-NAC impaired activity, whereas NSC 689534/Cu2+ effectively synergized with the glutathione biosynthesis inhibitor, buthionine sulphoximine. Microarray analysis of NSC 689534/Cu2+-treated cells highlighted activation of pathways involved in oxidative and ER-stress/UPR, autophagy and metal metabolism. Further scrutiny of the role of ER-stress and autophagy indicated that NSC 689534/Cu2+ -induced cell death was ER-stress dependent and autophagy-independent. Lastly, NSC 689534/Cu2+ was shown to have activity in an HL60 xenograft model. These data suggest that NSC 689534/Cu2+ is a potent oxidative stress inducer worthy of further preclinical investigation. PMID:20971185

  3. Hyperlipidemia-induced hepatic and small intestine ER stress and decreased paraoxonase 1 expression and activity is associated with HDL dysfunction in Syrian hamsters.

    Science.gov (United States)

    Stancu, Camelia S; Carnuta, Mihaela G; Sanda, Gabriela M; Toma, Laura; Deleanu, Mariana; Niculescu, Loredan S; Sasson, Shlomo; Simionescu, Maya; Sima, Anca V

    2015-11-01

    We aimed at investigating the mechanisms linking hyperlipidemia (HL) with dysfunctional HDL and its main antioxidant enzyme, paraoxonase1 (PON1). PON1 expression and activity was determined in the small intestine, liver, and sera of normal and HL hamsters and associated with the ER stress (ERS) and the development of aortic valve lesions. Male Golden Syrian hamsters were fed standard chow (N) or standard diet with 3% cholesterol and 15% butter for 16 weeks. All hamsters on fat diet developed HL, 50% also hyperglycemia (HLHG) and a fourfold increased homeostasis model assessment of insuline resistance. PON1 expression was reduced in the small intestine and liver (N > HL > HLHG) along with the increased extent of ERS, oxidized lipids, and decreased expression of liver X receptors beta (LXRβ) in the small intestine, peroxisome proliferator-activated receptor-γ (PPARγ) in the liver, and of the glucose transporter 4 in the myocardium. Serum PON1 levels decreased along with the increase of oxidized LDL and lesion areas of the aortic valves (N > HL > HLHG). The fat diet activates the ERS and oxidative stress, decreases LXRβ, PPARγ, and PON1 in the small intestine, liver, and sera of all HL animals, in parallel with the appearance of atherosclerotic lesions in the aortic valves. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Pre-disposition and epigenetics govern variation in bacterial survival upon stress.

    Directory of Open Access Journals (Sweden)

    Ming Ni

    Full Text Available Bacteria suffer various stresses in their unpredictable environment. In response, clonal populations may exhibit cell-to-cell variation, hypothetically to maximize their survival. The origins, propagation, and consequences of this variability remain poorly understood. Variability persists through cell division events, yet detailed lineage information for individual stress-response phenotypes is scarce. This work combines time-lapse microscopy and microfluidics to uniformly manipulate the environmental changes experienced by clonal bacteria. We quantify the growth rates and RpoH-driven heat-shock responses of individual Escherichia coli within their lineage context, stressed by low streptomycin concentrations. We observe an increased variation in phenotypes, as different as survival from death, that can be traced to asymmetric division events occurring prior to stress induction. Epigenetic inheritance contributes to the propagation of the observed phenotypic variation, resulting in three-fold increase of the RpoH-driven expression autocorrelation time following stress induction. We propose that the increased permeability of streptomycin-stressed cells serves as a positive feedback loop underlying this epigenetic effect. Our results suggest that stochasticity, pre-disposition, and epigenetic effects are at the source of stress-induced variability. Unlike in a bet-hedging strategy, we observe that cells with a higher investment in maintenance, measured as the basal RpoH transcriptional activity prior to antibiotic treatment, are more likely to give rise to stressed, frail progeny.

  5. Mitochondrial elongation-mediated glucose metabolism reprogramming is essential for tumour cell survival during energy stress.

    Science.gov (United States)

    Li, J; Huang, Q; Long, X; Guo, X; Sun, X; Jin, X; Li, Z; Ren, T; Yuan, P; Huang, X; Zhang, H; Xing, J

    2017-08-24

    To date, mechanisms of tumour cell survival under energy stress are not well understood. Cumulative evidence is beginning to reveal that specific mitochondrial morphologies are often associated with energetic states and survival of cells. However, the functional roles of mitochondria in the metabolic adaptation of tumour cells to energy stress remain to be elucidated. In this study, we first investigated the changes in mitochondrial morphology induced by nutrition deprivation in tumour cells, and the underlying molecular mechanism. We then systematically explored glucose metabolism reprogramming by energy stress-induced alteration of mitochondrial morphology and its effect on tumour cell survival. Our results showed that starvation treatment resulted in a dramatic mitochondrial elongation, which was mainly mediated by DRP1S637 phosphorylation through protein kinase A activation and subsequent suppression of mitochondrial translocation of DRP1. We further observed that tumour cells under an energy stress condition exhibited a clear shift from glycolysis towards oxidative phosphorylation, which was reversed by the recovery of mitochondrial fission induced by forced expression of mutant DRP1S637A. Mechanistically, energy stress-induced mitochondrial elongation facilitated cristae formation and assembly of respiratory complexes to enhance oxidative phosphorylation, which in turn exhibited a feedback inhibitory effect on glycolysis through NAD+-dependent SIRT1 activation. In addition, our data indicated that DRP1S637-mediated mitochondrial elongation under energy stress was essential for tumour cell survival both in vitro and in vivo and predicted poor prognosis of hepatocellular carcinoma patients. Overall, our study demonstrates that remodelling of mitochondrial morphology plays a critical role in tumour cell adaptation to energy stress by reprogramming glucose metabolism.

  6. The NAC domain-containing protein, GmNAC6, is a downstream component of the ER stress- and osmotic stress-induced NRP-mediated cell-death signaling pathway

    Directory of Open Access Journals (Sweden)

    Pinheiro Guilherme L

    2011-09-01

    Full Text Available Abstract Background The endoplasmic reticulum (ER is a major signaling organelle, which integrates a variety of responses against physiological stresses. In plants, one such stress-integrating response is the N-rich protein (NRP-mediated cell death signaling pathway, which is synergistically activated by combined ER stress and osmotic stress signals. Despite the potential of this integrated signaling to protect plant cells against different stress conditions, mechanistic knowledge of the pathway is lacking, and downstream components have yet to be identified. Results In the present investigation, we discovered an NAC domain-containing protein from soybean, GmNAC6 (Glycine max NAC6, to be a downstream component of the integrated pathway. Similar to NRP-A and NRP-B, GmNAC6 is induced by ER stress and osmotic stress individually, but requires both signals for full activation. Transient expression of GmNAC6 promoted cell death and hypersensitive-like responses in planta. GmNAC6 and NRPs also share overlapping responses to biotic signals, but the induction of NRPs peaked before the increased accumulation of GmNAC6 transcripts. Consistent with the delayed kinetics of GmNAC6 induction, increased levels of NRP-A and NRP-B transcripts induced promoter activation and the expression of the GmNAC6 gene. Conclusions Collectively, our results biochemically link GmNAC6 to the ER stress- and osmotic stress-integrating cell death response and show that GmNAC6 may act downstream of the NRPs.

  7. The impact of oxygen availability on stress survival and radical formation of Bacillus cereus

    NARCIS (Netherlands)

    Mols, J.M.; Pier, I.; Zwietering, M.H.; Abee, T.

    2009-01-01

    Both the growth and stress survival of two model Bacillus cereus strains, ATCC 14579 and ATCC 10987, were tested in three different conditions varying in oxygen availability, i.e., aerobic, microaerobic and anaerobic conditions. Both B. cereus strains displayed highest growth rates and yields under

  8. Combination of proteasome and class I HDAC inhibitors induces apoptosis of NPC cells through an HDAC6-independent ER stress-induced mechanism.

    Science.gov (United States)

    Hui, Kwai Fung; Chiang, Alan K S

    2014-12-15

    The current paradigm stipulates that inhibition of histone deacetylase (HDAC) 6 is essential for the combinatorial effect of proteasome and HDAC inhibitors for the treatment of cancers. Our study aims to investigate the effect of combining different class I HDAC inhibitors (without HDAC6 action) with a proteasome inhibitor on apoptosis of nasopharyngeal carcinoma (NPC). We found that combination of a proteasome inhibitor, bortezomib, and several class I HDAC inhibitors, including MS-275, apicidin and romidepsin, potently induced killing of NPC cells both in vitro and in vivo. Among the drug pairs, combination of bortezomib and romidepsin (bort/romidepsin) was the most potent and could induce apoptosis at low nanomolar concentrations. The apoptosis of NPC cells was reactive oxygen species (ROS)- and caspase-dependent but was independent of HDAC6 inhibition. Of note, bort/romidepsin might directly suppress the formation of aggresome through the downregulation of c-myc. In addition, two markers of endoplasmic reticulum (ER) stress-induced apoptosis, ATF-4 and CHOP/GADD153, were upregulated, whereas a specific inhibitor of caspase-4 (an initiator of ER stress-induced apoptosis) could suppress the apoptosis. When ROS level in the NPC cells was reduced to the untreated level, ER stress-induced caspase activation was abrogated. Collectively, our data demonstrate a model of synergism between proteasome and class I HDAC inhibitors in the induction of ROS-dependent ER stress-induced apoptosis of NPC cells, independent of HDAC6 inhibition, and provide the rationale to combine the more specific and potent class I HDAC inhibitors with proteasome inhibitors for the treatment of cancers. © 2014 UICC.

  9. Survival

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data provide information on the survival of California red-legged frogs in a unique ecosystem to better conserve this threatened species while restoring...

  10. IL-6 and IL-10 Anti-Inflammatory Activity Links Exercise to Hypothalamic Insulin and Leptin Sensitivity through IKKβ and ER Stress Inhibition

    Science.gov (United States)

    Ropelle, Eduardo R.; Flores, Marcelo B.; Cintra, Dennys E.; Rocha, Guilherme Z.; Pauli, José R.; Morari, Joseane; de Souza, Claudio T.; Moraes, Juliana C.; Prada, Patrícia O.; Guadagnini, Dioze; Marin, Rodrigo M.; Oliveira, Alexandre G.; Augusto, Taize M.; Carvalho, Hernandes F.; Velloso, Lício A.; Saad, Mario J. A.; Carvalheira, José B. C.

    2010-01-01

    Overnutrition caused by overeating is associated with insulin and leptin resistance through IKKβ activation and endoplasmic reticulum (ER) stress in the hypothalamus. Here we show that physical exercise suppresses hyperphagia and associated hypothalamic IKKβ/NF-κB activation by a mechanism dependent upon the pro-inflammatory cytokine interleukin (IL)-6. The disruption of hypothalamic-specific IL-6 action blocked the beneficial effects of exercise on the re-balance of food intake and insulin and leptin resistance. This molecular mechanism, mediated by physical activity, involves the anti-inflammatory protein IL-10, a core inhibitor of IKKβ/NF-κB signaling and ER stress. We report that exercise and recombinant IL-6 requires IL-10 expression to suppress hyperphagia-related obesity. Moreover, in contrast to control mice, exercise failed to reverse the pharmacological activation of IKKβ and ER stress in C3H/HeJ mice deficient in hypothalamic IL-6 and IL-10 signaling. Hence, inflammatory signaling in the hypothalamus links beneficial physiological effects of exercise to the central action of insulin and leptin. PMID:20808781

  11. Humic Acid Increases Amyloid β-Induced Cytotoxicity by Induction of ER Stress in Human SK-N-MC Neuronal Cells

    Directory of Open Access Journals (Sweden)

    Hsin-Hua Li

    2015-05-01

    Full Text Available Humic acid (HA is a possible etiological factor associated with for several vascular diseases. It is known that vascular risk factors can directly increase the susceptibility to Alzheimer’s disease (AD, which is a neurodegenerative disorder due to accumulation of amyloid β (Aβ peptide in the brain. However, the role that HA contributes to Aβ-induced cytotoxicity has not been demonstrated. In the present study, we demonstrate that HA exhibits a synergistic effect enhancing Aβ-induced cytotoxicity in cultured human SK-N-MC neuronal cells. Furthermore, this deterioration was mediated through the activation of endoplasmic reticulum (ER stress by stimulating PERK and eIF2α phosphorylation. We also observed HA and Aβ-induced cytotoxicity is associated with mitochondrial dysfunction caused by down-regulation of the Sirt1/PGC1α pathway, while in contrast, treating the cells with the ER stress inhibitor Salubrinal, or over-expression of Sirt1 significantly reduced loss of cell viability by HA and Aβ. Our findings suggest a new mechanism by which HA can deteriorate Aβ-induced cytotoxicity through modulation of ER stress, which may provide significant insights into the pathogenesis of AD co-occurring with vascular injury.

  12. Urotensin II Induces ER Stress and EMT and Increase Extracellular Matrix Production in Renal Tubular Epithelial Cell in Early Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Xin-Xin Pang

    2016-07-01

    Full Text Available Background/Aims: Urotensin II (UII and its receptor are highly expressed in the kidney tissue of patients with diabetic nephropathy (DN. The aim of this study is to examine the roles of UII in the induction of endoplasmic reticulum stress (ER stress and Epithelial-mesenchymal transition (EMT in DN in vivo and in vitro. Methods: Kidney tissues were collected from patients with DN. C57BL/6 mice and mice with UII receptor knock out were injected with two consecutive doses of streptozotocin to induce diabetes and were sacrificed at 3th week for in vivo study. HK-2 cells in vitro were cultured and treated with UII. Markers of ER stress and EMT, fibronectin and type IV collagen were detected by immunohistochemistry, real time PCR and western blot. Results: We found that the expressions of protein of UII, GRP78, CHOP, ALPHA-SMA, fibronectin and type IV collagen were upregulated while E-cadherin protein was downregulated as shown by immunohistochemistry or western blot analysis in kidney of diabetic mice in comparison to normal control; moreover expressions of GRP78, CHOP, ALPHA-SMA, fibronectin and type IV collagen were inhibited while E-caherin expression was enhanced in kidney in diabetic mice with UII receptor knock out in comparison to C57BL/6 diabetic mice. In HK-2 cells, UII induced upregulation of GRP78, CHOP, ALPHA-SMA, fibroblast-specifc protein 1(FSP-1, fibronectin and type collagen and downregulation of E-cadherin. UII receptor antagonist can block UII-induced ER stress and EMT; moreover, 4-PBA can inhibit the mRNA expression of ALPHA-SMA and FSP1 induced by UII in HK-2 cells. Conclusions: We are the first to verify UII induces ER stress and EMT and increase extracellular matrix production in renal tubular epithelial cell in early diabetic mice. Moreover, UII may induce renal tubular epithelial EMT via triggering ER stress pathway in vitro, which might be the new pathogenic pathway for the development of renal fibrosis in DN.

  13. [Peculiarities of behavior of offspring of rats-ambidexters after surviving vital stress].

    Science.gov (United States)

    Avaliani, T V; Apraksina, N K; Lazarenko, N S; Tsikunov, S G

    2013-01-01

    Psychogenic trauma inflicted to mothers (Wistar rats) during pregnancy is more tragic for establishment of psychoemotional functions in offspring than in the rat pups whose mothers survived prior to pregnancy the stress connected with threat of life. The "antenatal stress" causes in the one-month-old offspring the depression-like behavior, while the stress one month prior to conception--the increased anxiety. Disturbances of the integral behavior in the test "open field" can be caused both by the acute psychogenic trauma of mothers and by its delayed consequences. The sharp impoverishment of behavior and the more pronounced psychoemotional disturbances are realized in female individuals regardless of the terms of the action. In the male offspring the vital stress during their mothers' pregnancy produces the rougher behavioral disturbances than stress prior to conception.

  14. Survival of Salmonella serovars on beef carcasses and molecular mechanisms to survive low temperature stress and desiccation

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Thomsen, Line Elnif; Aabo, Søren

    2006-01-01

    . Infantis and S. Newport. This experiment indicates that storage at low temperature of beef carcasses can be used as a reduction strategy for Salmonella spp. in beef. In addition molecular mechanisms to resist low temperature stress and desiccation have been investigated. Mutants in the otsA, rpoS and clp...... at 10°C and 15°C, the ¿clpP mutant was severely affected in ability to form colonies compared to the wildtype. Neither the ¿otsA nor the ¿rpoS were affected in growth or survival at low temperature. In a desiccation model, both the ¿rpoS and ¿clpP mutant were more sensitive than the C5 wildtype...

  15. MiR-17-5p impairs trafficking of H-ERG K+ channel protein by targeting multiple er stress-related chaperones during chronic oxidative stress.

    Directory of Open Access Journals (Sweden)

    Qi Wang

    Full Text Available BACKGROUND: To investigate if microRNAs (miRNAs play a role in regulating h-ERG trafficking in the setting of chronic oxidative stress as a common deleterious factor for many cardiac disorders. METHODS: We treated neonatal rat ventricular myocytes and HEK293 cells with stable expression of h-ERG with H2O2 for 12 h and 48 h. Expression of miR-17-5p seed miRNAs was quantified by real-time RT-PCR. Protein levels of chaperones and h-ERG trafficking were measured by Western blot analysis. Luciferase reporter gene assay was used to study miRNA and target interactions. Whole-cell patch-clamp techniques were employed to record h-ERG K(+ current. RESULTS: H-ERG trafficking was impaired by H2O2 after 48 h treatment, accompanied by reciprocal changes of expression between miR-17-5p seed miRNAs and several chaperones (Hsp70, Hsc70, CANX, and Golga2, with the former upregulated and the latter downregulated. We established these chaperones as targets for miR-17-5p. Application miR-17-5p inhibitor rescued H2O2-induced impairment of h-ERG trafficking. Upregulation of endogenous by H2O2 or forced miR-17-5p expression either reduced h-ERG current. Sequestration of AP1 by its decoy molecule eliminated the upregulation of miR-17-5p, and ameliorated impairment of h-ERG trafficking. CONCLUSIONS: Collectively, deregulation of the miR-17-5p seed family miRNAs can cause severe impairment of h-ERG trafficking through targeting multiple ER stress-related chaperones, and activation of AP1 likely accounts for the deleterious upregulation of these miRNAs, in the setting of prolonged duration of oxidative stress. These findings revealed the role of miRNAs in h-ERG trafficking, which may contribute to the cardiac electrical disturbances associated with oxidative stress.

  16. Role of an ER stress response element in regulating the bidirectional promoter of the mouse CRELD2 - ALG12 gene pair

    Directory of Open Access Journals (Sweden)

    Hirata Yoko

    2010-11-01

    Full Text Available Abstract Background Recently, we identified cysteine-rich with EGF-like domains 2 (CRELD2 as a novel endoplasmic reticulum (ER stress-inducible gene and characterized its transcriptional regulation by ATF6 under ER stress conditions. Interestingly, the CRELD2 and asparagine-linked glycosylation 12 homolog (ALG12 genes are arranged as a bidirectional (head-to-head gene pair and are separated by less than 400 bp. In this study, we characterized the transcriptional regulation of the mouse CRELD2 and ALG12 genes that is mediated by a common bidirectional promoter. Results This short intergenic region contains an ER stress response element (ERSE sequence and is well conserved among the human, rat and mouse genomes. Microarray analysis revealed that CRELD2 and ALG12 mRNAs were induced in Neuro2a cells by treatment with thapsigargin (Tg, an ER stress inducer, in a time-dependent manner. Other ER stress inducers, tunicamycin and brefeldin A, also increased the expression of these two mRNAs in Neuro2a cells. We then tested for the possible involvement of the ERSE motif and other regulatory sites of the intergenic region in the transcriptional regulation of the mouse CRELD2 and ALG12 genes by using variants of the bidirectional reporter construct. With regards to the promoter activities of the CRELD2-ALG12 gene pair, the entire intergenic region hardly responded to Tg, whereas the CRELD2 promoter constructs of the proximal region containing the ERSE motif showed a marked responsiveness to Tg. The same ERSE motif of ALG12 gene in the opposite direction was less responsive to Tg. The direction and the distance of this motif from each transcriptional start site, however, has no impact on the responsiveness of either gene to Tg treatment. Additionally, we found three putative sequences in the intergenic region that antagonize the ERSE-mediated transcriptional activation. Conclusions These results show that the mouse CRELD2 and ALG12 genes are arranged as a

  17. Regulation of apoptotic pathways by Stylophora pistillata (Anthozoa, Pocilloporidae) to survive thermal stress and bleaching.

    Science.gov (United States)

    Kvitt, Hagit; Rosenfeld, Hanna; Zandbank, Keren; Tchernov, Dan

    2011-01-01

    Elevated seawater temperatures are associated with coral bleaching events and related mortality. Nevertheless, some coral species are able to survive bleaching and recover. The apoptotic responses associated to this ability were studied over 3 years in the coral Stylophora pistillata from the Gulf of Eilat subjected to long term thermal stress. These include caspase activity and the expression profiles of the S. pistillata caspase and Bcl-2 genes (StyCasp and StyBcl-2-like) cloned in this study. In corals exposed to thermal stress (32 or 34°C), caspase activity and the expression levels of the StyBcl-2-like gene increased over time (6-48 h) and declined to basal levels within 72 h of thermal stress. Distinct transcript levels were obtained for the StyCasp gene, with stimulated expression from 6 to 48 h of 34°C thermal stress, coinciding with the onset of bleaching. Increased cell death was detected in situ only between 6 to 48 h of stress and was limited to the gastroderm. The bleached corals survived up to one month at 32°C, and recovered back symbionts when placed at 24°C. These results point to a two-stage response in corals that withstand thermal stress: (i) the onset of apoptosis, accompanied by rapid activation of anti-oxidant/anti-apoptotic mediators that block the progression of apoptosis to other cells and (ii) acclimatization of the coral to the chronic thermal stress alongside the completion of symbiosis breakdown. Accordingly, the coral's ability to rapidly curb apoptosis appears to be the most important trait affecting the coral's thermotolerance and survival.

  18. Regulation of apoptotic pathways by Stylophora pistillata (Anthozoa, Pocilloporidae to survive thermal stress and bleaching.

    Directory of Open Access Journals (Sweden)

    Hagit Kvitt

    Full Text Available Elevated seawater temperatures are associated with coral bleaching events and related mortality. Nevertheless, some coral species are able to survive bleaching and recover. The apoptotic responses associated to this ability were studied over 3 years in the coral Stylophora pistillata from the Gulf of Eilat subjected to long term thermal stress. These include caspase activity and the expression profiles of the S. pistillata caspase and Bcl-2 genes (StyCasp and StyBcl-2-like cloned in this study. In corals exposed to thermal stress (32 or 34°C, caspase activity and the expression levels of the StyBcl-2-like gene increased over time (6-48 h and declined to basal levels within 72 h of thermal stress. Distinct transcript levels were obtained for the StyCasp gene, with stimulated expression from 6 to 48 h of 34°C thermal stress, coinciding with the onset of bleaching. Increased cell death was detected in situ only between 6 to 48 h of stress and was limited to the gastroderm. The bleached corals survived up to one month at 32°C, and recovered back symbionts when placed at 24°C. These results point to a two-stage response in corals that withstand thermal stress: (i the onset of apoptosis, accompanied by rapid activation of anti-oxidant/anti-apoptotic mediators that block the progression of apoptosis to other cells and (ii acclimatization of the coral to the chronic thermal stress alongside the completion of symbiosis breakdown. Accordingly, the coral's ability to rapidly curb apoptosis appears to be the most important trait affecting the coral's thermotolerance and survival.

  19. Reduced Insulin/Insulin-Like Growth Factor Receptor Signaling Mitigates Defective Dendrite Morphogenesis in Mutants of the ER Stress Sensor IRE-1.

    Directory of Open Access Journals (Sweden)

    Yehuda Salzberg

    2017-01-01

    Full Text Available Neurons receive excitatory or sensory inputs through their dendrites, which often branch extensively to form unique neuron-specific structures. How neurons regulate the formation of their particular arbor is only partially understood. In genetic screens using the multidendritic arbor of PVD somatosensory neurons in the nematode Caenorhabditis elegans, we identified a mutation in the ER stress sensor IRE-1/Ire1 (inositol requiring enzyme 1 as crucial for proper PVD dendrite arborization in vivo. We further found that regulation of dendrite growth in cultured rat hippocampal neurons depends on Ire1 function, showing an evolutionarily conserved role for IRE-1/Ire1 in dendrite patterning. PVD neurons of nematodes lacking ire-1 display reduced arbor complexity, whereas mutations in genes encoding other ER stress sensors displayed normal PVD dendrites, specifying IRE-1 as a selective ER stress sensor that is essential for PVD dendrite morphogenesis. Although structure function analyses indicated that IRE-1's nuclease activity is necessary for its role in dendrite morphogenesis, mutations in xbp-1, the best-known target of non-canonical splicing by IRE-1/Ire1, do not exhibit PVD phenotypes. We further determined that secretion and distal localization to dendrites of the DMA-1/leucine rich transmembrane receptor (DMA-1/LRR-TM is defective in ire-1 but not xbp-1 mutants, suggesting a block in the secretory pathway. Interestingly, reducing Insulin/IGF1 signaling can bypass the secretory block and restore normal targeting of DMA-1, and consequently normal PVD arborization even in the complete absence of functional IRE-1. This bypass of ire-1 requires the DAF-16/FOXO transcription factor. In sum, our work identifies a conserved role for ire-1 in neuronal branching, which is independent of xbp-1, and suggests that arborization defects associated with neuronal pathologies may be overcome by reducing Insulin/IGF signaling and improving ER homeostasis and

  20. The response of trypanosomes and other eukaryotes to ER stress and the spliced leader RNA silencing (SLS) pathway in Trypanosoma brucei.

    Science.gov (United States)

    Michaeli, Shulamit

    2015-01-01

    The unfolded protein response (UPR) is induced when the quality control machinery of the cell is overloaded with unfolded proteins or when one of the functions of the endoplasmic reticulum (ER) is perturbed. Here, I describe UPR in yeast and mammals, and compare it to what we know about pathogenic fungi and the parasitic protozoans from the order kinetoplastida, focusing on the novel pathway the spliced leader silencing (SLS) in Trypanosoma brucei. Trypanosomes lack conventional transcription regulation, and thus, lack most of the UPR machinery present in other eukaryotes. Trypanosome genes are transcribed in polycistronic units that are processed by trans-splicing and polyadenylation. In trans-splicing, which is essential for processing of each mRNA, an exon known as the spliced leader (SL) is added to all mRNAs from a small RNA, the SL RNA. Under severe ER stress, T. brucei elicits the SLS pathway. In SLS, the transcription of the SL RNA gene is extinguished, and the entire transcription complex dissociates from the SL RNA promoter. Induction of SLS is mediated by an ER-associated kinase (PK3) that migrates to the nucleus, where it phosphorylates the TATA-binding protein (TRF4), leading shut-off of SL RNA transcription. As a result, trans-splicing is inhibited and the parasites activate a programmed cell death (PCD) pathway. Despite the ability to sense the ER stress, the different eukaryotes, especially unicellular parasites and pathogenic fungi, developed a variety of unique and different ways to sense and adjust to this stress in a manner different from their host.

  1. Modeling of thermal stresses and probability of survival of tubular SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Nakajo, Arata [Laboratory for Industrial Energy Systems (LENI), Faculty of Engineering, Swiss Federal Institute of Technology, 1015 Lausanne (Switzerland); Stiller, Christoph; Bolland, Olav [Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim N-7491 (Norway); Haerkegaard, Gunnar [Department of Engineering Design and Materials, Norwegian University of Science and Technology, Trondheim N-7491 (Norway)

    2006-07-14

    The temperature profile generated by a thermo-electro-chemical model was used to calculate the thermal stress distribution in a tubular solid oxide fuel cell (SOFC). The solid heat balances were calculated separately for each layer of the MEA (membrane electrode assembly) in order to detect the radial thermal gradients more precisely. It appeared that the electrolyte undergoes high tensile stresses at the ends of the cell in limited areas and that the anode is submitted to moderate tensile stresses. A simplified version of the widely used Weibull analysis was used to calculate the global probability of survival for the assessment of the risks related to both operating points and load changes. The cell at room temperature was considered and revealed as critical. As a general trend, the computed probabilities of survival were too low for the typical requirements for a commercial product. A sensitivity analysis showed a strong influence of the thermal expansion mismatch between the layers of the MEA on the probability of survival. The lack of knowledge on mechanical material properties as well as uncertainties about the phenomena occurring in the cell revealed itself as a limiting parameter for the simulation of thermal stresses. (author)

  2. Stress-Survival Gene Identification From an Acid Mine Drainage Algal Mat Community

    Science.gov (United States)

    Urbina-Navarrete, J.; Fujishima, K.; Paulino-Lima, I. G.; Rothschild-Mancinelli, B.; Rothschild, L. J.

    2014-12-01

    Microbial communities from acid mine drainage environments are exposed to multiple stressors to include low pH, high dissolved metal loads, seasonal freezing, and desiccation. The microbial and algal communities that inhabit these niche environments have evolved strategies that allow for their ecological success. Metagenomic analyses are useful in identifying species diversity, however they do not elucidate the mechanisms that allow for the resilience of a community under these extreme conditions. Many known or predicted genes encode for protein products that are unknown, or similarly, many proteins cannot be traced to their gene of origin. This investigation seeks to identify genes that are active in an algal consortium during stress from living in an acid mine drainage environment. Our approach involves using the entire community transcriptome for a functional screen in an Escherichia coli host. This approach directly targets the genes involved in survival, without need for characterizing the members of the consortium.The consortium was harvested and stressed with conditions similar to the native environment it was collected from. Exposure to low pH (E. coli. The transformed E. coli were exposed to the same stressors as the original algal consortium to select for surviving cells. Successful cells incorporated the transcripts that encode survival mechanisms, thus allowing for selection and identification of the gene(s) involved. Initial selection screens for freeze and desiccation tolerance have yielded E. coli that are 1 order of magnitude more resistant to freezing (0.01% survival of control with no transcript, 0.2% survival of E. coli with transcript) and 3 orders of magnitude more resistant to desiccation (0.005% survival of control cells with no transcripts, 5% survival of cells with transcript).This work is transformative because genetic functions can be selected without having prior knowledge of the genes or of the organisms involved. Work continues to

  3. Effects of food stress on survival and reproductive performance of seabirds

    Science.gov (United States)

    Piatt, John F.; Kitaysky, Sasha

    2001-01-01

    Traditional field methods of assessing effects of fluctuations in food supply on the survival and reproductive performance of seabirds may give equivocal results. In this project we applied an additional tool: The measure of stress hormones in free-ranging seabirds. Food stress can be quantified by measuring base levels of stress hormones such as corticosterone in the blood of seabirds, or the rise in blood levels of corticosterone in response to a standardized stressor: capture, handling and restraint. We applied these techniques to seabirds breeding in Lower Cook Inlet and also used captive birds for controlled experiments. This study provided a unique opportunity for a concurrent field and captive study of the behavioral and physiological consequences of stress in seabirds. Moreover, this study provides the basis for management of seabird populations in the areas affected by the Exxon Valdez oil spill, which will have broader applications for seabird monitoring programs. This year represents production of a synthesis of the project.

  4. Proteomic analysis of INS-1 rat insulinoma cells: ER stress effects and the protective role of exenatide, a GLP-1 receptor agonist.

    Directory of Open Access Journals (Sweden)

    Mi-Kyung Kim

    Full Text Available Beta cell death caused by endoplasmic reticulum (ER stress is a key factor aggravating type 2 diabetes. Exenatide, a glucagon-like peptide (GLP-1 receptor agonist, prevents beta cell death induced by thapsigargin, a selective inhibitor of ER calcium storage. Here, we report on our proteomic studies designed to elucidate the underlying mechanisms. We conducted comparative proteomic analyses of cellular protein profiles during thapsigargin-induced cell death in the absence and presence of exenatide in INS-1 rat insulinoma cells. Thapsigargin altered cellular proteins involved in metabolic processes and protein folding, whose alterations were variably modified by exenatide treatment. We categorized the proteins with thapsigargin initiated alterations into three groups: those whose alterations were 1 reversed by exenatide, 2 exaggerated by exenatide, and 3 unchanged by exenatide. The most significant effect of thapsigargin on INS-1 cells relevant to their apoptosis was the appearance of newly modified spots of heat shock proteins, thimet oligopeptidase and 14-3-3β, ε, and θ, and the prevention of their appearance by exenatide, suggesting that these proteins play major roles. We also found that various modifications in 14-3-3 isoforms, which precede their appearance and promote INS-1 cell death. This study provides insights into the mechanisms in ER stress-caused INS-1 cell death and its prevention by exenatide.

  5. ER Stress and Autophagic Perturbations Lead to Elevated Extracellular α-Synuclein in GBA-N370S Parkinson's iPSC-Derived Dopamine Neurons

    Directory of Open Access Journals (Sweden)

    Hugo J.R. Fernandes

    2016-03-01

    Full Text Available Heterozygous mutations in the glucocerebrosidase gene (GBA represent the strongest common genetic risk factor for Parkinson's disease (PD, the second most common neurodegenerative disorder. However, the molecular mechanisms underlying this association are still poorly understood. Here, we have analyzed ten independent induced pluripotent stem cell (iPSC lines from three controls and three unrelated PD patients heterozygous for the GBA-N370S mutation, and identified relevant disease mechanisms. After differentiation into dopaminergic neurons, we observed misprocessing of mutant glucocerebrosidase protein in the ER, associated with activation of ER stress and abnormal cellular lipid profiles. Furthermore, we observed autophagic perturbations and an enlargement of the lysosomal compartment specifically in dopamine neurons. Finally, we found increased extracellular α-synuclein in patient-derived neuronal culture medium, which was not associated with exosomes. Overall, ER stress, autophagic/lysosomal perturbations, and elevated extracellular α-synuclein likely represent critical early cellular phenotypes of PD, which might offer multiple therapeutic targets.

  6. Expression of HSF2 decreases in mitosis to enable stress-inducible transcription and cell survival

    Science.gov (United States)

    Elsing, Alexandra N.; Aspelin, Camilla; Björk, Johanna K.; Bergman, Heidi A.; Himanen, Samu V.; Kallio, Marko J.; Roos-Mattjus, Pia

    2014-01-01

    Unless mitigated, external and physiological stresses are detrimental for cells, especially in mitosis, resulting in chromosomal missegregation, aneuploidy, or apoptosis. Heat shock proteins (Hsps) maintain protein homeostasis and promote cell survival. Hsps are transcriptionally regulated by heat shock factors (HSFs). Of these, HSF1 is the master regulator and HSF2 modulates Hsp expression by interacting with HSF1. Due to global inhibition of transcription in mitosis, including HSF1-mediated expression of Hsps, mitotic cells are highly vulnerable to stress. Here, we show that cells can counteract transcriptional silencing and protect themselves against proteotoxicity in mitosis. We found that the condensed chromatin of HSF2-deficient cells is accessible for HSF1 and RNA polymerase II, allowing stress-inducible Hsp expression. Consequently, HSF2-deficient cells exposed to acute stress display diminished mitotic errors and have a survival advantage. We also show that HSF2 expression declines during mitosis in several but not all human cell lines, which corresponds to the Hsp70 induction and protection against stress-induced mitotic abnormalities and apoptosis. PMID:25202032

  7. Effect of storage temperatures and stresses on the survival of Salmonella spp. in halva.

    Science.gov (United States)

    Osaili, T M; Al-Nabulsi, A A; Nazzal, D S; Shaker, R R

    2017-11-01

    The presence of Salmonella spp. in halva has been associated with foodborne illnesses and product recalls from the markets. This study investigated the effect of environmental stresses on the survival of Salmonella spp. in halva during storage for 12 months at 10 and 25°C (log (N 0 /N) g -1 ). Halva samples were inoculated with a cocktail of four strains of unstressed, desiccation stressed or heat stressed Salmonella (10 6 -10 7  CFU per gram). In general, survival of Salmonella spp. in halva decreased significantly (P ˂ 0·05) as storage time and temperature increased. At the end of halva shelf life at 10°C, the initial populations of unstressed, desiccation stressed or heat stressed Salmonella spp. decreased by 2·7, 2·6 or 2·8 log CFU per gram (reduction rate c. 0·2 log CFU per month), respectively. While at 25°C, the populations decreased 5·2, 6·7 or 6·3 log CFU per gram, respectively (reduction rate c. 0·4-0·5 log CFU per month). The populations of stressed Salmonella spp. in halva samples were not significantly different (P ≥ 0·05) from populations of unstressed cells during storage at 10 and 25°C, except during the last 3 months of storage at 25°C when populations of unstressed cells were higher (P tahini halva) with Salmonella from raw materials or during production was documented. Halva and tahini have been involved in salmonellosis outbreaks in different countries. The study demonstrated enhanced survivability of stressed and unstressed Salmonella spp. in halva over a 12-month storage period at 10 and 25°C with lower log reductions than expected. Exposing Salmonella spp. to desiccation or heat stress prior product contamination may play a role in microbial survival in halva during storage. These findings serve as a model to halva producers to implement control measures to prevent Salmonella spp. contamination in halva. © 2017 The Society for Applied Microbiology.

  8. ERK1/2 signalling protects against apoptosis following endoplasmic reticulum stress but cannot provide long-term protection against BAX/BAK-independent cell death

    Science.gov (United States)

    Darling, Nicola J.; Balmanno, Kathryn

    2017-01-01

    Disruption of protein folding in the endoplasmic reticulum (ER) causes ER stress. Activation of the unfolded protein response (UPR) acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2) signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway. PMID:28931068

  9. Determination of survival, identity and stress resistance of probiotic bifidobacteria in bio-yoghurts.

    Science.gov (United States)

    Jayamanne, V S; Adams, M R

    2006-03-01

    To determine the level of bifidobacteria in bio-yoghurts in the UK, identify the species, and compare the resistance of common Bifidobacterium spp. to acidity and oxidative stress. A storage trial of bio-yoghurts was carried out to determine the level and survival of bifidobacteria. The 16S rRNA gene targeted PCR was used to identify the species. Acid tolerance was determined by introducing the organisms to pH-adjusted skimmed milk and enumerating during storage at 4 degrees C. Oxidative stress resistance was determined using the H(2)O(2) disc diffusion assay technique. Nine of 10 bio-yoghurts contained bifidobacteria at levels >10(6) CFU g(-1) at the time of purchase. The viability of the organism decreased during storage and on expiry only five products retained viability >10(6) CFU g(-1) while two others were very close to the target population. Bifidobacterium animalis ssp. lactis showed superior survival abilities and stress tolerance compared with Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium bifidum, Bifidobacterium adolescentis and Bifidobacterium longum biotype infantis. Bifidobacterium animalis ssp. lactis, the only Bifidobacterium spp. found in bio-yoghurts, had the greatest resistance to acidity and oxidative stress. The technological properties of B. animalis ssp. lactis make it suitable for inclusion in bio-yoghurts although its putative health benefits need further investigation.

  10. Cognitive function, stress hormones, heart rate and nutritional status during simulated captivity in military survival training.

    Science.gov (United States)

    Lieberman, Harris R; Farina, Emily K; Caldwell, John; Williams, Kelly W; Thompson, Lauren A; Niro, Philip J; Grohmann, Kyle A; McClung, James P

    2016-10-15

    Stress influences numerous psychological and physiological processes, and its effects have practical implications in a variety of professions and real-world activities. However, few studies have concurrently assessed multiple behavioral, hormonal, nutritional and heart-rate responses of humans to acute, severe stress. This investigation simultaneously assessed cognitive, affective, hormonal, and heart-rate responses induced by an intensely stressful real-world environment designed to simulate wartime captivity. Sixty males were evaluated during and immediately following participation in U.S. Army Survival, Evasion, Resistance, and Escape (SERE) school, three weeks of intense but standardized training for Soldiers at risk of capture. Simulated captivity and intense mock interrogations degraded grammatical reasoning (pworking memory (pnutritional status and heart rate are simultaneously altered, and each of these subsequently recovers at different rates. Published by Elsevier Inc.

  11. Clp chaperones and proteases are central in stress survival, virulence and antibiotic resistance of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Frees, Dorte; Gerth, Ulf; Ingmer, Hanne

    2014-01-01

    proteins. The ATP-dependent ClpP protease is highly conserved among eubacteria and in the chloroplasts and mitochondria of eukaryotic cells. In the serious human pathogen, Staphylococcus aureus inactivation of clpP rendered the bacterium avirulent emphasizing the central role of proteolysis in virulence....... The contribution of the Clp proteins to virulence is likely to occur at multiple levels. First of all, both Clp ATPases and the Clp protease are central players in stress responses required to cope with the adverse conditions met in the host. The ClpP protease has a dual role herein, as it both eliminates stress......-damaged proteins as well as ensures the timely degradation of major stress regulators such as Spx, LexA and CtsR. Additionally, as we will summarize in this review, Clp proteases and Clp chaperones impact on such central processes as virulence gene expression, cell wall metabolism, survival in stationary phase...

  12. Distributing tasks via multiple input pathways increases cellular survival in stress.

    Science.gov (United States)

    Granados, Alejandro A; Crane, Matthew M; Montano-Gutierrez, Luis F; Tanaka, Reiko J; Voliotis, Margaritis; Swain, Peter S

    2017-05-17

    Improving in one aspect of a task can undermine performance in another, but how such opposing demands play out in single cells and impact on fitness is mostly unknown. Here we study budding yeast in dynamic environments of hyperosmotic stress and show how the corresponding signalling network increases cellular survival both by assigning the requirements of high response speed and high response accuracy to two separate input pathways and by having these pathways interact to converge on Hog1, a p38 MAP kinase. Cells with only the less accurate, reflex-like pathway are fitter in sudden stress, whereas cells with only the slow, more accurate pathway are fitter in increasing but fluctuating stress. Our results demonstrate that cellular signalling is vulnerable to trade-offs in performance, but that these trade-offs can be mitigated by assigning the opposing tasks to different signalling subnetworks. Such division of labour could function broadly within cellular signal transduction.

  13. ALS Patient Stem Cells for Unveiling Disease Signatures of Motoneuron Susceptibility: Perspectives on the Deadly Mitochondria, ER Stress and Calcium Triad

    Science.gov (United States)

    Kaus, Anjoscha; Sareen, Dhruv

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is a largely sporadic progressive neurodegenerative disease affecting upper and lower motoneurons (MNs) whose specific etiology is incompletely understood. Mutations in superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TARDBP/TDP-43) and C9orf72, have been identified in subsets of familial and sporadic patients. Key associated molecular and neuropathological features include ubiquitinated TDP-43 inclusions, stress granules, aggregated dipeptide proteins from mutant C9orf72 transcripts, altered mitochondrial ultrastructure, dysregulated calcium homeostasis, oxidative and endoplasmic reticulum (ER) stress, and an unfolded protein response (UPR). Such impairments have been documented in ALS animal models; however, whether these mechanisms are initiating factors or later consequential events leading to MN vulnerability in ALS patients is debatable. Human induced pluripotent stem cells (iPSCs) are a valuable tool that could resolve this “chicken or egg” causality dilemma. Relevant systems for probing pathophysiologically affected cells from large numbers of ALS patients and discovering phenotypic disease signatures of early MN susceptibility are described. Performing unbiased ‘OMICS and high-throughput screening in relevant neural cells from a cohort of ALS patient iPSCs, and rescuing mitochondrial and ER stress impairments, can identify targeted therapeutics for increasing MN longevity in ALS. PMID:26635528

  14. Oxidative Stress Promotes Peroxiredoxin Hyperoxidation and Attenuates Pro-survival Signaling in Aging Chondrocytes.

    Science.gov (United States)

    Collins, John A; Wood, Scott T; Nelson, Kimberly J; Rowe, Meredith A; Carlson, Cathy S; Chubinskaya, Susan; Poole, Leslie B; Furdui, Cristina M; Loeser, Richard F

    2016-03-25

    Oxidative stress-mediated post-translational modifications of redox-sensitive proteins are postulated as a key mechanism underlying age-related cellular dysfunction and disease progression. Peroxiredoxins (PRX) are critical intracellular antioxidants that also regulate redox signaling events. Age-related osteoarthritis is a common form of arthritis that has been associated with mitochondrial dysfunction and oxidative stress. The objective of this study was to determine the effect of aging and oxidative stress on chondrocyte intracellular signaling, with a specific focus on oxidation of cytosolic PRX2 and mitochondrial PRX3. Menadione was used as a model to induce cellular oxidative stress. Compared with chondrocytes isolated from young adult humans, chondrocytes from older adults exhibited higher levels of PRX1-3 hyperoxidation basally and under conditions of oxidative stress. Peroxiredoxin hyperoxidation was associated with inhibition of pro-survival Akt signaling and stimulation of pro-death p38 signaling. These changes were prevented in cultured human chondrocytes by adenoviral expression of catalase targeted to the mitochondria (MCAT) and in cartilage explants from MCAT transgenic mice. Peroxiredoxin hyperoxidation was observedin situin human cartilage sections from older adults and in osteoarthritic cartilage. MCAT transgenic mice exhibited less age-related osteoarthritis. These findings demonstrate that age-related oxidative stress can disrupt normal physiological signaling and contribute to osteoarthritis and suggest peroxiredoxin hyperoxidation as a potential mechanism. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Mitochondrial stress and activation of PI3K and Akt survival pathway in bladder ischemia

    Directory of Open Access Journals (Sweden)

    Yang JH

    2017-06-01

    Full Text Available Jing-Hua Yang,1 Mike B Siroky,1 Subbarao V Yalla,2 Kazem M Azadzoi3,4 1Department of Urology, VA Boston Healthcare System, Boston University School of Medicine, 2Department of Urology, VA Boston Healthcare System, Harvard Medical School, 3Department of Urology, 4Department of Pathology, VA Boston Healthcare System, Boston University School of Medicine, Boston, MA, USA Purpose: Detrusor overactivity contributes to bothersome constellation of lower urinary tract symptoms (LUTS in men and women as they age. However, the underlying mechanisms of non-obstructive detrusor overactivity and LUTS remain largely unknown. Growing evidence suggests that ischemia may be an independent factor in the development of non-obstructive bladder dysfunction. Our goal was to determine the effects of ischemia on detrusor function and voiding behavior and define redox-mediated cellular stress and cell survival signaling in the ischemic bladder. Materials and methods: Male Sprague Dawley rats were randomly divided into treatment (n=8 and control (n=8 groups. In the treatment group, iliac artery atherosclerosis and chronic bladder ischemia were induced. At 8 weeks after bladder ischemia, voiding patterns were examined in metabolic cages, cystometrograms were recorded in conscious animals, and then bladder blood flow was measured under general anesthesia. Bladder tissues were processed for assessment of transcription factors, markers of cellular and mitochondrial stress, mitochondrial respiration, and cell survival signaling pathway.Results: Atherosclerotic occlusive disease spread from the common iliac arteries to the internal iliac and vesical arteries and produced sustained bladder ischemia. Studies in metabolic cages showed increased micturition frequency and decreased voided volume in bladder ischemia. Conscious cystometrograms produced consistent data showing significant increase in micturition frequency and decreased voided volume and bladder capacity. Voiding

  16. Chronic Insulin Exposure Induces ER Stress and Lipid Body Accumulation in Mast Cells at the Expense of Their Secretory Degranulation Response

    Science.gov (United States)

    Balajadia, Januaria; Shimoda, Lori M. N.; Sung, Carl; Turner, Helen

    2015-01-01

    Lipid bodies (LB) are reservoirs of precursors to inflammatory lipid mediators in immunocytes, including mast cells. LB numbers are dynamic, increasing dramatically under conditions of immunological challenge. We have previously shown in vitro that insulin-influenced lipogenic pathways induce LB biogenesis in mast cells, with their numbers attaining steatosis-like levels. Here, we demonstrate that in vivo hyperinsulinemia resulting from high fat diet is associated with LB accumulation in murine mast cells and basophils. We characterize the lipidome of purified insulin-induced LB, and the shifts in the whole cell lipid landscape in LB that are associated with their accumulation, in both model (RBL2H3) and primary mast cells. Lipidomic analysis suggests a gain of function associated with LB accumulation, in terms of elevated levels of eicosanoid precursors that translate to enhanced antigen-induced LTC4 release. Loss-of-function in terms of a suppressed degranulation response was also associated with LB accumulation, as were ER reprogramming and ER stress, analogous to observations in the obese hepatocyte and adipocyte. Taken together, these data suggest that chronic insulin elevation drives mast cell LB enrichment in vitro and in vivo, with associated effects on the cellular lipidome, ER status and pro-inflammatory responses. PMID:26263026

  17. Chronic Insulin Exposure Induces ER Stress and Lipid Body Accumulation in Mast Cells at the Expense of Their Secretory Degranulation Response.

    Directory of Open Access Journals (Sweden)

    William E Greineisen

    Full Text Available Lipid bodies (LB are reservoirs of precursors to inflammatory lipid mediators in immunocytes, including mast cells. LB numbers are dynamic, increasing dramatically under conditions of immunological challenge. We have previously shown in vitro that insulin-influenced lipogenic pathways induce LB biogenesis in mast cells, with their numbers attaining steatosis-like levels. Here, we demonstrate that in vivo hyperinsulinemia resulting from high fat diet is associated with LB accumulation in murine mast cells and basophils. We characterize the lipidome of purified insulin-induced LB, and the shifts in the whole cell lipid landscape in LB that are associated with their accumulation, in both model (RBL2H3 and primary mast cells. Lipidomic analysis suggests a gain of function associated with LB accumulation, in terms of elevated levels of eicosanoid precursors that translate to enhanced antigen-induced LTC4 release. Loss-of-function in terms of a suppressed degranulation response was also associated with LB accumulation, as were ER reprogramming and ER stress, analogous to observations in the obese hepatocyte and adipocyte. Taken together, these data suggest that chronic insulin elevation drives mast cell LB enrichment in vitro and in vivo, with associated effects on the cellular lipidome, ER status and pro-inflammatory responses.

  18. The Antarctic nematode Plectus murrayi: an emerging model to study multiple stress survival.

    Science.gov (United States)

    Adhikari, Bishwo N; Tomasel, Cecilia M; Li, Grace; Wall, Diana H; Adams, Byron J

    2010-11-01

    The genus Plectus is one of the most widely distributed and common nematode taxa of freshwater and terrestrial habitats in the world, and is of particular interest because of its phylogenetic position relative to the origin of the Secernentean radiation. Plectus murrayi, a bacteria-feeding nematode, inhabits both semi-aquatic and terrestrial biotopes in the Antarctic McMurdo Dry Valleys (MCM), where its distribution is limited by organic carbon and soil moisture. Plectus nematodes from the MCM can survive extreme desiccation, freezing conditions, and other types of stress. Ongoing investigations of the physiological and molecular aspects of the stress biology of P. murrayi, along with the availability of genomic resources, will likely establish this nematode as an excellent invertebrate model system for studies of extreme environmental survival, and may provide a valuable source of genomic resources for comparative studies in other organisms. Moreover, because P. murrayi and Caenorhabditis elegans share a most recent common ancestor with the rest of the Secernentea, and given the ability of P. murrayi to be cultured at lower temperatures compared to C. elegans, P. murrayi could also be an emerging model system for the study of the evolution of environment-sensitive (stress response) alleles in nematodes.

  19. Induction of apoptosis through ER stress and TP53 in MCF-7 cells by the nanoparticle [Gd@C82(OH)22]n: A systems biology study.

    Science.gov (United States)

    Wang, Lin; Meng, Jie; Cao, Weipeng; Li, Qizhai; Qiu, Yuqing; Sun, Baoyun; Li, Lei M

    2014-06-01

    The nanoparticle gadolinium endohedral metallofullerenol [Gd@C82(OH)22]n is a new candidate for cancer treatment with low toxicity. However, its anti-cancer mechanisms remain mostly unknown. In this study, we took a systems biology view of the gene expression profiles of human breast cancer cells (MCF-7) and human umbilical vein endothelial cells (ECV304) treated with and without [Gd@C82(OH)22]n, respectively, measured by the Agilent Gene Chip G4112F. To properly analyze these data, we modified a suit of statistical methods we developed. For the first time we applied the sub-sub normalization to Agilent two-color microarrays. Instead of a simple linear regression, we proposed to use a one-knot SPLINE model in the sub-sub normalization to account for nonlinear spatial effects. The parameters estimated by least trimmed squares- and S-estimators show similar normalization results. We made several kinds of inferences by integrating the expression profiles with the bioinformatic knowledge in KEGG pathways, Gene Ontology, JASPAR, and TRANSFAC. In the transcriptional inference, we proposed the BASE2.0 method to infer a transcription factor's up-regulation and down-regulation activities separately. Overall, [Gd@C82(OH)22]n induces more differentiation in MCF-7 cells than in ECV304 cells, particularly in the reduction of protein processing such as protein glucosylation, folding, targeting, exporting, and transporting. Among the KEGG pathways, the ErbB signaling pathway is up-regulated, whereas protein processing in endoplasmic reticulum (ER) is down-regulated. CHOP, a key pro-apoptotic gene downstream of the ER stress pathway, increases to nine folds in MCF-7 cells after treatment. These findings indicate that ER stress may be one important factor that induces apoptosis in MCF-7 cells after [Gd@C82(OH)22]n treatment. The expression profiles of genes associated with ER stress and apoptosis are statistically consistent with other profiles reported in the literature, such as

  20. Interstitial lung disease and myositis-specific and associated autoantibodies: Clinical manifestations, survival and the performance of the new ATS/ERS criteria for interstitial pneumonia with autoimmune features (IPAF).

    Science.gov (United States)

    Mejía, Mayra; Herrera-Bringas, Denisse; Pérez-Román, Diana I; Rivero, Hermes; Mateos-Toledo, Heidegger; Castorena-García, Pedro; Figueroa, José E; Rojas-Serrano, Jorge

    2017-02-01

    to describe the clinical manifestations and survival of patients with ILD and myositis-specific and associated autoantibodies, and to evaluate the performance of the new ATS/ERS classification criteria for IPAF. Patients with ILD and positive in at least one of the following autoantibodies: anti-Jo-1, anti-Ej, anti-PL7, anti-PL 12, anti-PM/SCL 75 and anti-PM/SCL100 were included. Patients were separated into three groups according to their autoantibody profile: 1. Jo-1 positive patients, 2. Non-Jo-1 antisynthetase autoantibody positive patients, and 3. PM/SCL positive patients. Relevant clinical characteristics were registered. Patients were evaluated had they fulfilled Bohan and Peter's criteria (BPC) for inflammatory myopathies. We evaluated the performance of the IPAF ATS/ERS proposal to classify as such the patients that did not fulfilled BPC, and evaluated whether IPAF patients had a worse survival that BPC patients. Sixty-eight patients were included. Jo-1 was the most frequent autoantibody (65%), followed by non Jo1 anti-synthetase autoantibodies (31%). Non-Jo1 patients had lower Creatin Kinase serum levels at the baseline and less frequency of arthritis. Only 50% of patients fulfilled BPC. All patients not complying with BPC did comply with IPAF criteria. There was no difference in survival between IPAF and BPC patients. Anti Jo-1 positive was associated to survival and the extent of lung inflammation was associated to mortality. Patients differ in clinical manifestations according to the autoantibody profile. All patients not complying with BPC did comply with the new IPAF criteria. There was no difference in survival between BPC and IPAF patients. Jo-1 patients had a better survival. Extent of lung inflammation was associate to mortality. Published by Elsevier Ltd.

  1. Propofol attenuates H2O2-induced oxidative stress and apoptosis via the mitochondria- and ER-medicated pathways in neonatal rat cardiomyocytes.

    Science.gov (United States)

    Liu, Xue-Ru; Cao, Lu; Li, Tao; Chen, Lin-Lin; Yu, Yi-Yan; Huang, Wen-Jun; Liu, Li; Tan, Xiao-Qiu

    2017-05-01

    Previous studies have shown that propofol, an intravenous anesthetic commonly used in clinical practice, protects the myocardium from injury. Mitochondria- and endoplasmic reticulum (ER)-mediated oxidative stress and apoptosis are two important signaling pathways involved in myocardial injury and protection. The present study aimed to test the hypothesis that propofol could exert a cardio-protective effect via the above two pathways. Cultured neonatal rat cardiomyocytes were treated with culture medium (control group), H2O2 at 500 μM (H2O2 group), propofol at 50 μM (propofol group), and H2O2 plus propofol (H2O2 + propofol group), respectively. The oxidative stress, mitochondrial membrane potential (ΔΨm) and apoptosis of the cardiomyocytes were evaluated by a series of assays including ELISA, flow cytometry, immunofluorescence microscopy and Western blotting. Propofol significantly suppressed the H2O2-induced elevations in the activities of caspases 3, 8, 9 and 12, the ratio of Bax/Bcl-2, and cell apoptosis. Propofol also inhibited the H2O2-induced reactive oxygen species (ROS) generation, lactic dehydrogenase (LDH) release and mitochondrial transmembrane potential (ΔΨm) depolarization, and restored the H2O2-induced reductions of glutathione (GSH) and superoxide dismutase (SOD). In addition, propofol decreased the expressions of glucose-regulated protein 78 kDa (Grp78) and inositol-requiring enzyme 1α (IRE1α), two important signaling molecules in the ER-mediated apoptosis pathway. Propofol protects cardiomyocytes from H2O2-induced injury by inhibiting the mitochondria- and ER-mediated apoptosis signaling pathways.

  2. Survival, growth and stress response of juvenile tidewater goby, Eucyclogobius newberryi, to interspecific competition for food.

    Science.gov (United States)

    Chase, Daniel A; Flynn, Erin E; Todgham, Anne E

    2016-01-01

    Reintroduction of endangered fishes to historic habitat has been used as a recovery tool; however, these fish may face competition from other fishes that established in their native habitat since extirpation. This study investigated the physiological response of tidewater goby, Eucyclogobius newberryi, an endangered California fish, when competing for food with threespine stickleback, Gasterosteus aculeatus, a native species, and rainwater killifish, Lucania parva, a non-native species. Survival, growth and physiological indicators of stress (i.e. cortisol, glucose and lactate concentrations) were assessed for juvenile fish held for 28 days in two food-limited conditions. When fed a 75% ration, survival of E. newberryi was significantly lower when held with G. aculeatus. In all fish assemblages, weight and relative condition decreased then stabilized over the 28 day experiment, while length remained unchanged. Whole-body cortisol in E. newberryi was not affected by fish assemblage; however, glucose and lactate concentrations were significantly higher with conspecifics than with other fish assemblages. When fed a 50% ration, survival of E. newberryi decreased during the second half of the experiment, while weight and relative condition decreased and length remained unchanged in all three fish assemblages. Cortisol concentrations were significantly higher for all fish assemblages compared with concentrations at the start of the experiment, whereas glucose and lactate concentrations were depressed relative to concentrations at the start of the experiment, with the magnitude of decrease dependent on the species assemblage. Our findings indicate that E. newberryi exhibited reduced growth and an elevated generalized stress response during low food availability. In response to reduced food availability, competition with G. aculeatus had the greatest physiological effect on E. newberryi, with minimal effects from the non-native L. parva. This study presents the first

  3. Oxidative stress survival in a clinical Saccharomyces cerevisiae isolate is influenced by a major quantitative trait nucleotide.

    Science.gov (United States)

    Diezmann, Stephanie; Dietrich, Fred S

    2011-07-01

    One of the major challenges in characterizing eukaryotic genetic diversity is the mapping of phenotypes that are the cumulative effect of multiple alleles. We have investigated tolerance of oxidative stress in the yeast Saccharomyces cerevisiae, a trait showing phenotypic variation in the population. Initial crosses identified that this is a quantitative trait. Microorganisms experience oxidative stress in many environments, including during infection of higher eukaryotes. Natural variation in oxidative stress tolerance is an important aspect of response to oxidative stress exerted by the human immune system and an important trait in microbial pathogens. A clinical isolate of the usually benign yeast S. cerevisiae was found to survive oxidative stress significantly better than the laboratory strain. We investigated the genetic basis of increased peroxide survival by crossing those strains, phenotyping 1500 segregants, and genotyping of high-survival segregants by hybridization of bulk and single segregant DNA to microarrays. This effort has led to the identification of an allele of the transcription factor Rds2 as contributing to stress response. Rds2 has not previously been associated with the survival of oxidative stress. The identification of its role in the oxidative stress response here is an example of a specific trait that appears to be beneficial to Saccharomyces cerevisiae when growing as a pathogen. Understanding the role of this fungal-specific transcription factor in pathogenicity will be important in deciphering how fungi infect and colonize the human host and could eventually lead to a novel drug target.

  4. Surviving in a frozen desert: environmental stress physiology of terrestrial Antarctic arthropods.

    Science.gov (United States)

    Teets, Nicholas M; Denlinger, David L

    2014-01-01

    Abiotic stress is one of the primary constraints limiting the range and success of arthropods, and nowhere is this more apparent than Antarctica. Antarctic arthropods have evolved a suite of adaptations to cope with extremes in temperature and water availability. Here, we review the current state of knowledge regarding the environmental physiology of terrestrial arthropods in Antarctica. To survive low temperatures, mites and Collembola are freeze-intolerant and rely on deep supercooling, in some cases supercooling below -30°C. Also, some of these microarthropods are capable of cryoprotective dehydration to extend their supercooling capacity and reduce the risk of freezing. In contrast, the two best-studied Antarctic insects, the midges Belgica antarctica and Eretmoptera murphyi, are freeze-tolerant year-round and rely on both seasonal and rapid cold-hardening to cope with decreases in temperature. A common theme among Antarctic arthropods is extreme tolerance of dehydration; some accomplish this by cuticular mechanisms to minimize water loss across their cuticle, while a majority have highly permeable cuticles but tolerate upwards of 50-70% loss of body water. Molecular studies of Antarctic arthropod stress physiology are still in their infancy, but several recent studies are beginning to shed light on the underlying mechanisms that govern extreme stress tolerance. Some common themes that are emerging include the importance of cuticular and cytoskeletal rearrangements, heat shock proteins, metabolic restructuring and cell recycling pathways as key mediators of cold and water stress in the Antarctic.

  5. Effect of intrapartum fetal stress associated with obstetrical interventions on viability and survivability of canine neonates

    Directory of Open Access Journals (Sweden)

    Karthik V. Kuttan

    2016-12-01

    Full Text Available Aim: This study was conducted with the objective of identifying and evaluating intrapartum fetal stress in connection with the type of delivery in bitches. Materials and Methods: A total of 26 bitches between 1 and 5 years, belonging to 10 different breeds were evaluated. Bitches were subjected to detailed clinico-gynecological examination based on history. Neonatal stress associated with spontaneous whelping (SW, assisted whelping (AW, and emergency cesarean section (EC was evaluated using umbilical vein lactate (UL estimation by collecting the blood from umbilical vein. Results: A high umbilical vein lactate value was associated with fetal distress. The mean umbilical lactate value was highest in EC (12.54±0.8 mmol/L followed by AW (8.86±0.9 mmol/L and the lowest value was found in SW (7.56±0.58 mmol/L. A significant increase (p<0.05 in umbilical lactate level was observed in EC group of canine neonates compared with AW and SW groups. Overall mean umbilical lactate values of neonates which died within 24 h (13.31±1.08 mmol/L and the neonates which survived beyond 24 h (8.87±0.55 mmol/L differed significantly at 5% level. Conclusion: Immediate identification of neonatal distress by use of umbilical vein lactate estimation is helpful for the clinician to undertake resuscitation or medical therapy to ensure better neonatal survivability.

  6. Habitat quality affects stress responses and survival in a bird wintering under extremely low ambient temperatures

    Science.gov (United States)

    Cīrule, Dina; Krama, Tatjana; Krams, Ronalds; Elferts, Didzis; Kaasik, Ants; Rantala, Markus J.; Mierauskas, Pranas; Luoto, Severi; Krams, Indrikis A.

    2017-12-01

    Animals normally respond to stressful environmental stimuli by releasing glucocorticoid hormones. We investigated whether baseline corticosterone (CORT), handling-induced corticosterone concentration(s), and body condition indices of members of willow tit ( Poecile montanus) groups differed while wintering in old growth forests and managed young forests in mild weather conditions and during cold spells. Willow tits spend the winter season in non-kin groups in which dominant individuals typically claim their priority to access resources, while subordinate individuals may experience greater levels of stress and higher mortality, especially during cold spells. We captured birds to measure baseline CORT and levels of handling-induced CORT secretion after 20 min of capture. Willow tits in the young forests had higher baseline CORT and a smaller increase in CORT in response to capture than individuals in the old forests. Baseline CORT was higher in females and juvenile birds compared to adult males, whereas handling-induced CORT secretion did not differ between birds of different ages. During cold spells, baseline CORT of willow tits increased and handling-induced CORT secretion decreased, especially in birds in young forests. Willow tits' survival was higher in the old forests, with dominant individuals surviving better than subordinates. Our results show that changes in CORT secretion reflect responses to habitat quality and climate harshness, indicating young managed coniferous forests as a suboptimal habitat for the willow tit.

  7. A Mycobacterium avium subsp. paratuberculosis Predicted Serine Protease Is Associated with Acid Stress and Intraphagosomal Survival.

    Science.gov (United States)

    Kugadas, Abirami; Lamont, Elise A; Bannantine, John P; Shoyama, Fernanda M; Brenner, Evan; Janagama, Harish K; Sreevatsan, Srinand

    2016-01-01

    The ability to maintain intra-cellular pH is crucial for bacteria and other microbes to survive in diverse environments, particularly those that undergo fluctuations in pH. Mechanisms of acid resistance remain poorly understood in mycobacteria. Although, studies investigating acid stress in M. tuberculosis are gaining traction, few center on Mycobacterium avium subsp. paratuberculosis (MAP), the etiological agent of chronic enteritis in ruminants. We identified a MAP acid stress response network involved in macrophage infection. The central node of this network was MAP0403, a predicted serine protease that shared an 86% amino acid identity with MarP in M. tuberculosis. Previous studies confirmed MarP as a serine protease integral to maintaining intra-bacterial pH and survival in acid in vitro and in vivo. We show that MAP0403 is upregulated in infected macrophages and MAC-T cells that coincided with phagosome acidification. Treatment of mammalian cells with bafilomcyin A1, a potent inhibitor of phagosomal vATPases, diminished MAP0403 transcription. MAP0403 expression was also noted in acidic medium. A surrogate host, M. smegmatis mc(2) 155, was designed to express MAP0403 and when exposed to either macrophages or in vitro acid stress had increased bacterial cell viability, which corresponds to maintenance of intra-bacterial pH in acidic (pH = 5) conditions, compared to the parent strain. These data suggest that MAP0403 may be the equivalent of MarP in MAP. Future studies confirming MAP0403 as a serine protease and exploring its structure and possible substrates are warranted.

  8. A Mycobacterium avium subsp. paratuberculosis predicted serine protease is associated with acid stress and intraphagosomal survival

    Directory of Open Access Journals (Sweden)

    Abirami Kugadas

    2016-08-01

    Full Text Available AbstractThe ability to maintain intra-cellular pH is crucial for bacteria and other microbes to survive in diverse environments, particularly those that undergo fluctuations in pH. Mechanisms of acid resistance remain poorly understood in mycobacteria. Although studies investigating acid stress in M. tuberculosis are gaining traction, few center on Mycobacterium avium subsp. paratuberculosis (MAP, the etiological agent of chronic enteritis in ruminants. We identified a MAP acid stress response network involved in macrophage infection. The central node of this network was MAP0403, a predicted serine protease that shared an 86% amino acid identity with MarP in M. tuberculosis. Previous studies confirmed MarP as a serine protease integral to maintaining intra-bacterial pH and survival in acid in vitro and in vivo. We show that MAP0403 is upregulated in infected macrophage and MAC-T cells and coincided with phagosome acidification. Treatment of mammalian cells with bafilomcyin A1, a potent inhibitor of phagosomal vATPases, diminished MAP0403 transcription. MAP0403 expression was also noted in acidic medium. A surrogate host, M. smegmatis mc2 155, was designed to express MAP0403 and when exposed to either macrophages or in vitro acid stress had increase bacterial cell viability, which corresponds to maintenance of intra-bacterial pH in acidic (pH = 5 conditions. These data suggest that MAP0403 may be the equivalent of MarP in MAP. Future studies confirming MAP0403 as a serine protease and exploring its structure and possible substrates are warranted.

  9. Survival of Listeria monocytogenes with different antibiotic resistance patterns to food-associated stresses.

    Science.gov (United States)

    Komora, Norton; Bruschi, Carolina; Magalhães, Rui; Ferreira, Vânia; Teixeira, Paula

    2017-03-20

    The ongoing rise of antibiotic resistant microbial pathogens has become one of the major public health threats worldwide. Despite all the effort and actions taken so far, a proliferation of antibiotic resistant (AR) and multi-antibiotic resistant (MAR) strains is still observed, including in foodborne pathogens. This trend has been also noted recently for isolates of Listeria monocytogenes, a species that, although remaining largely sensitive to clinically relevant antimicrobials, has been reported to develop increased tolerance to antibiotics, particularly in isolates recovered from the food-chain. In this study we compared the ability of MAR (n=8), AR (n=18) and antibiotic susceptible (AS, n=11) L. monocytogenes strains from food and clinical origin to survive to different environmental stress conditions, including temperature (58°C), acidic stress (1% v/v lactic acid, pH3.5), and osmotic stress (37% w/v NaCl). The presence of antibiotic active efflux among MAR and AR strains, and its role on L. monocytogenes tolerance to different antimicrobial compounds was also investigated, namely; hydrogen peroxide; organic acids (acetic, citric and lactic); nisin; benzalkonium chloride (BC); and, sodium nitrite. While no significant differences were observed in the survival of the 37 strains exposed to high temperature (58°C), overall the mean logarithmic reduction of clinical strains was statistically lower after acid and salt exposure than that observed for strains of food origin; but both food and clinical strains resistant to two or three antibiotics were significantly less susceptible to acid (lactic acid 1% v/v) and osmotic stresses (37% w/v NaCl) when compared to AS strains. Using the EtBr-agar Cartwheel method, it was possible to detect efflux pumps in three of the 26 MAR and AR isolates, including one control strain; the active efflux in theses isolates was proven to be associated with fluoroquinolone resistance, and possible extrusion of BC and hydrogen peroxide

  10. Clp chaperones and proteases are central in stress survival, virulence and antibiotic resistance of Staphylococcus aureus.

    Science.gov (United States)

    Frees, Dorte; Gerth, Ulf; Ingmer, Hanne

    2014-03-01

    Intracellular proteolysis carried out by energy-dependent proteases is one of the most conserved biological processes. In all cells proteolysis maintains and shapes the cellular proteome by ridding the cell of damaged proteins and by regulating abundance of functional proteins such as regulatory proteins. The ATP-dependent ClpP protease is highly conserved among eubacteria and in the chloroplasts and mitochondria of eukaryotic cells. In the serious human pathogen, Staphylococcus aureus inactivation of clpP rendered the bacterium avirulent emphasizing the central role of proteolysis in virulence. The contribution of the Clp proteins to virulence is likely to occur at multiple levels. First of all, both Clp ATPases and the Clp protease are central players in stress responses required to cope with the adverse conditions met in the host. The ClpP protease has a dual role herein, as it both eliminates stress-damaged proteins as well as ensures the timely degradation of major stress regulators such as Spx, LexA and CtsR. Additionally, as we will summarize in this review, Clp proteases and Clp chaperones impact on such central processes as virulence gene expression, cell wall metabolism, survival in stationary phase, and cell division. These observations together with recent findings that Clp proteins contribute to adaptation to antibiotics highlights the importance of this interesting proteolytic machinery both for understanding pathogenicity of the organism and for treating staphylococcal infections. Copyright © 2013 Elsevier GmbH. All rights reserved.

  11. Glycolaldehyde induces endoplasmic reticulum stress and apoptosis in Schwann cells

    Directory of Open Access Journals (Sweden)

    Keisuke Sato

    2015-01-01

    Full Text Available Schwann cell injury is caused by diabetic neuropathy. The apoptosis of Schwann cells plays a pivotal role in diabetic nerve dysfunction. Glycolaldehyde is a precursor of advanced glycation end products that contribute to the pathogenesis of diabetic neuropathy. In this study, we examined whether glycolaldehyde induces endoplasmic reticulum (ER stress and apoptosis in rat Schwann cells. Schwann cells treated with 500 μM glycolaldehyde showed morphological changes characteristic of apoptosis. Glycolaldehyde activated apoptotic signals, such as caspase-3 and caspase-8. Furthermore, it induced ER stress response involving RNA-dependent protein kinase-like ER kinase (PERK, inositol-requiring ER-to-nucleus signal kinase 1α (IRE1α, and eukaryotic initiation factor 2α (eIF2α. In addition, glycolaldehyde activated CCAAT/enhancer-binding homologous protein (CHOP, an ER stress response factor crucial to executing apoptosis. Knockdown of nuclear factor E2-related factor 2 (Nrf2, which is involved in the promotion of cell survival following ER stress, enhanced glycolaldehyde-induced cytotoxicity, indicating that Nrf2 plays a protective role in the cytotoxicity caused by glycolaldehyde. Taken together, these findings indicate that glycolaldehyde is capable of inducing apoptosis and ER stress in Schwann cells. The ER stress induced by glycolaldehyde may trigger the glycolaldehyde-induced apoptosis in Schwann cells. This study demonstrated for the first time that glycolaldehyde induced ER stress.

  12. Survivability of Salmonella typhimurium L1388 and Salmonella enteritidis L1225 under stressful growth conditions

    Directory of Open Access Journals (Sweden)

    Ngwai YB

    2007-11-01

    Full Text Available In an earlier study with Salmonella typhimurium L1388 (ST and Salmonella enteritidis L1225 (SE isolated from diseased chickens, we found that SE formed more biofilm than ST on abiotic surfaces in a time-dependent manner. Since the ability of salmonellae to survive extreme environment is related to their virulence, the present study examined the survival of Salmonella typhimurium L1388 and Salmonella nteritidis L1225 under the usual stresses that salmonellae encounter during their life cycle. This is with a view to understanding the strains’ stress tolerance that could be used to explain their virulence. Incubation at 37oC for various time periods was done for: i stationary phase (SP cells at pH 2.6; ii log-phase (LP cells at pH 4.0; log-phase or stationary phase cells in broth containing iii hydrogen peroxide, iv sodium chloride and v ethanol; vi stationary phase cells in Hank’s balanced salt solution (single strength containing 10% human serum; and vii prolong stationary phase cells. Stationary phase cells were also incubated at 52oC for 15 min. Surviving cells at the various incubation times were counted on trypticase soy agar (TSA after appropriate dilution in saline and overnight incubation at 37oC. Growth iron-poor medium was determined by growing a single bacterial colony in Medium A with shaking at 37oC or 40oC for 24 h. Statistics was done by one-way analysis-of-variance (ANOVA at P = 0.05. Differences in the survival of ST and SE were insignificant (p>0.05 in acid pH at both pH 4.0 (p = 0.3783 and pH 2.6 (p = 0.4711; at high salinity for log-phase (p = 0.1416 and stationary phase (p = 0.1816 cells; in ethanol (p = 0.5984, human serum (p = 0.8139, prolonged stationary phase (p = 0.3506; and under heat (p = 0.5766. SE was significantly (p<0.05; p = 0.0031 more tolerant to oxidative-killing by hydrogen peroxide. Culturable growth of the ST and SE in an iron-poor medium A revealed insignificant differences at 37oC (p = 0.8381 but

  13. ER stress and basement membrane defects combine to cause glomerular and tubular renal disease resulting from Col4a1 mutations in mice

    Directory of Open Access Journals (Sweden)

    Frances E. Jones

    2016-02-01

    Full Text Available Collagen IV is a major component of basement membranes, and mutations in COL4A1, which encodes collagen IV alpha chain 1, cause a multisystemic disease encompassing cerebrovascular, eye and kidney defects. However, COL4A1 renal disease remains poorly characterized and its pathomolecular mechanisms are unknown. We show that Col4a1 mutations in mice cause hypotension and renal disease, including proteinuria and defects in Bowman's capsule and the glomerular basement membrane, indicating a role for Col4a1 in glomerular filtration. Impaired sodium reabsorption in the loop of Henle and distal nephron despite elevated aldosterone levels indicates that tubular defects contribute to the hypotension, highlighting a novel role for the basement membrane in vascular homeostasis by modulation of the tubular response to aldosterone. Col4a1 mutations also cause diabetes insipidus, whereby the tubular defects lead to polyuria associated with medullary atrophy and a subsequent reduction in the ability to upregulate aquaporin 2 and concentrate urine. Moreover, haematuria, haemorrhage and vascular basement membrane defects confirm an important vascular component. Interestingly, although structural and compositional basement membrane defects occurred in the glomerulus and Bowman's capsule, no tubular basement membrane defects were detected. By contrast, medullary atrophy was associated with chronic ER stress, providing evidence for cell-type-dependent molecular mechanisms of Col4a1 mutations. These data show that both basement membrane defects and ER stress contribute to Col4a1 renal disease, which has important implications for the development of treatment strategies for collagenopathies.

  14. ER stress and basement membrane defects combine to cause glomerular and tubular renal disease resulting from Col4a1 mutations in mice

    Science.gov (United States)

    Jones, Frances E.; Bailey, Matthew A.; Murray, Lydia S.; Lu, Yinhui; McNeilly, Sarah; Schlötzer-Schrehardt, Ursula; Lennon, Rachel; Sado, Yoshikazu; Brownstein, David G.; Mullins, John J.; Kadler, Karl E.; Van Agtmael, Tom

    2016-01-01

    ABSTRACT Collagen IV is a major component of basement membranes, and mutations in COL4A1, which encodes collagen IV alpha chain 1, cause a multisystemic disease encompassing cerebrovascular, eye and kidney defects. However, COL4A1 renal disease remains poorly characterized and its pathomolecular mechanisms are unknown. We show that Col4a1 mutations in mice cause hypotension and renal disease, including proteinuria and defects in Bowman's capsule and the glomerular basement membrane, indicating a role for Col4a1 in glomerular filtration. Impaired sodium reabsorption in the loop of Henle and distal nephron despite elevated aldosterone levels indicates that tubular defects contribute to the hypotension, highlighting a novel role for the basement membrane in vascular homeostasis by modulation of the tubular response to aldosterone. Col4a1 mutations also cause diabetes insipidus, whereby the tubular defects lead to polyuria associated with medullary atrophy and a subsequent reduction in the ability to upregulate aquaporin 2 and concentrate urine. Moreover, haematuria, haemorrhage and vascular basement membrane defects confirm an important vascular component. Interestingly, although structural and compositional basement membrane defects occurred in the glomerulus and Bowman's capsule, no tubular basement membrane defects were detected. By contrast, medullary atrophy was associated with chronic ER stress, providing evidence for cell-type-dependent molecular mechanisms of Col4a1 mutations. These data show that both basement membrane defects and ER stress contribute to Col4a1 renal disease, which has important implications for the development of treatment strategies for collagenopathies. PMID:26839400

  15. Insulin Protects Hepatic Lipotoxicity by Regulating ER Stress through the PI3K/Akt/p53 Involved Pathway Independently of Autophagy Inhibition.

    Science.gov (United States)

    Ning, Hua; Sun, Zongxiang; Liu, Yunyun; Liu, Lei; Hao, Liuyi; Ye, Yaxin; Feng, Rennan; Li, Jie; Li, Ying; Chu, Xia; Li, Songtao; Sun, Changhao

    2016-04-19

    The detrimental role of hepatic lipotoxicity has been well-implicated in the pathogenesis of NAFLD. Previously, we reported that inhibiting autophagy aggravated saturated fatty acid (SFA)-induced hepatotoxicity. Insulin, a physiological inhibitor of autophagy, is commonly increased within NAFLD mainly caused by insulin resistance. We therefore hypothesized that insulin augments the sensitivity of hepatocyte to SFA-induced lipotoxicity. The present study was conducted via employing human and mouse hepatocytes, which were exposed to SFAs, insulin, or their combination. Unexpectedly, our results indicated that insulin protected hepatocytes against SFA-induced lipotoxicity, based on the LDH, MTT, and nuclear morphological measurements, and the detection from cleaved-Parp-1 and -caspase-3 expressions. We subsequently clarified that insulin led to a rapid and short-period inhibition of autophagy, which was gradually recovered after 1 h incubation in hepatocytes, and such extent of inhibition was insufficient to aggravate SFA-induced lipotoxicity. The mechanistic study revealed that insulin-induced alleviation of ER stress contributed to its hepatoprotective role. Pre-treating hepatocytes with insulin significantly stimulated phosphorylated-Akt and reversed SFA-induced up-regulation of p53. Chemical inhibition of p53 by pifithrin-α robustly prevented palmitate-induced cell death. The PI3K/Akt pathway blockade by its special antagonist abolished the protective role of insulin against SFA-induced lipotoxicity and p53 up-regulation. Furthermore, we observed that insulin promoted intracellular TG deposits in hepatocytes in the present of palmitate. However, blocking TG accumulation via genetically silencing DGAT-2 did not prevent insulin-protected lipotoxicity. Our study demonstrated that insulin strongly protected against SFA-induced lipotoxicity in hepatocytes mechanistically through alleviating ER stress via a PI3K/Akt/p53 involved pathway but independently from autophagy.

  16. Glycyrrhizic acid (GA) inhibits reactive oxygen Species mediated photodamage by blocking ER stress and MAPK pathway in UV-B irradiated human skin fibroblasts.

    Science.gov (United States)

    Farrukh, Mufti Rana; Nissar, Ul-Ashraf; Kaiser, Peerzada J; Afnan, Quadri; Sharma, Praduman R; Bhushan, Shashi; Tasduq, Sheikh A

    2015-07-01

    Previously we have reported that generation of reactive oxygen species is the prime event responsible for calcium mediated activation of PERK-eIF2α-CHOP pathway and apoptosis in UV-B irradiated human skin fibroblasts (Hs68). We have also reported that glycyrrhizic acid (GA) mediates potent photoprotective activity against UV-B - irradiation-induced photodamage in human skin fibroblast. In the present study, we aimed to investigate the role of GA in preventing oxidative stress mediated unfolded protein response (UPR) and mitogen activated protein kinases (MAPK) pathway. Human skin fibroblast (Hs68) cells were exposed to UV-B radiations in lab conditions. Different parameters of UVB induced cellular and molecular changes were analysed using western-blotting, microscopy and flow cytometry. Our results show that GA has strong photoprotective action against UV-B induced cellular damage. It was observed that: (a) Oxidative disturbances and intracellular Ca(2+) imbalance induced by UV-B irradiation was significantly restored by GA treatment; (b) activation of PERK-eIF2α-CHOP and MAPK pathway induced by UV-B was significantly blocked by GA; (c) Loss of mitochondrial membrane potential and apoptosis induced by UV-B were reduced by GA treatment. Based on the above findings we conclude GA has a highly significant ROS quenching activity, thereby blocking the cascade of events including release of calcium from ER and subsequent ER stress, MAPK pathway and cellular demise. GA offers highly potent anti photodamage effect and can be exploited for cosmetic or therapeutic purposes. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. 25(OH) vitamin D suppresses macrophage adhesion and migration by downregulation of ER stress and scavenger receptor A1 in type 2 diabetes.

    Science.gov (United States)

    Riek, Amy E; Oh, Jisu; Darwech, Isra; Moynihan, Clare E; Bruchas, Robin R; Bernal-Mizrachi, Carlos

    2014-10-01

    Cardiovascular disease (CVD) is the leading cause of mortality in patients with type 2 diabetes mellitus (T2DM). Vitamin D deficiency is not only more prevalent in diabetics but also doubles the risk of developing CVD. However, it is unknown whether 25-hydroxy vitamin D [25(OH)D3] replacement slows monocyte adhesion and migration, critical mechanisms involved in atherosclerosis progression. In this study, monocytes from vitamin D-deficient diabetic patients were cultured either in the patient's serum or in vitamin D-deficient media with or without 25(OH)D3 treatment. Adding 25(OH)D3 to monocytes cultured in vitamin D-deficient serum or media decreased monocyte adhesion to fibronectin and migration stimulated by monocyte chemotactic protein 1 (MCP-1). Accordingly, 25(OH)D3 decreased adhesion marker β1- and β2-integrin expression and migration receptor chemokine (C-C motif) receptor 2 (CCR2) expression. 25(OH)D3 treatment downregulated monocyte endoplasmic reticulum (ER) stress and scavenger receptor class A, type 1 (SR-A1) expression. The absence of SR-A1 prevented the increased macrophage adhesion and migration induced by vitamin D deficiency. Moreover, the absence of SR-A1 prevented the induction of adhesion and migration and expression of their associated membrane receptors by Thapsigargin, an ER stress inducer. These results identify cellular activation of monocyte/macrophage vitamin D signaling through 25(OH)D3 as a potential mechanism that could modulate adhesion and migration in diabetic subjects. This article is part of a Special Issue entitled '16th Vitamin D Workshop'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The effect of metformin treatment on endoplasmic reticulum (ER stress induced by status epilepticus (SE via the PERK-eIF2α-CHOP pathway

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2017-07-01

    Full Text Available Status epilepticus (SE is defined as continuous seizure activity lasting more than 5 minutes. It results in neuronal cell death, mediated by endoplasmic reticulum (ER stress response. Previously, metformin demonstrated neuroprotective effects in primary cortical neurons. In this study, we analyzed the effect of metformin on ER stress via the pro-apoptotic protein kinase RNA-like endoplasmic reticulum kinase (PERK - eukaryotic initiation factor 2α (eIF2α - C/EBP homologous protein (CHOP pathway. SE was induced in rats by pentylenetetrazole. Following SE, the rats were treated with salubrinal, GSK2656157, or metformin. In a control group (normal saline SE was not induced. CHOP, eIF2α, and PERK expression was determined by Western blot; apoptosis was analyzed by TUNEL assay. CHOP expression was significantly increased at 6 and 24 hours following SE. At both time points, eIF2α and PERK levels were also increased. At 6 hours, CHOP expression was significantly reduced in salubrinal, GSK2656157 and metformin groups. eIF2α and PERK levels were decreased in metformin group. eIF2α expression was dramatically reduced in salubrinal versus SE group, while PERK expression was markedly reduced in GSK2656157 versus SE group. At 6 and 24 hours, the apoptosis rate was significantly increased in SE versus control group, while it was significantly reduced in GSK2656157 and metformin groups. The apoptosis rate also decreased in salubrinal group at 24 hours, although not to the extent observed in metformin group. Overall, CHOP expression and apoptosis induced by SE in rats were reduced with metformin. Further studies are required to evaluate the clinical relevance of metformin for patients with SE.

  19. Anaerobic survival of Pseudomonas aeruginosa by pyruvate fermentation requires an Usp-type stress protein

    DEFF Research Database (Denmark)

    Schreiber, K; Boes, N; Escbach, M

    2006-01-01

    activity was detected in the deeper layers of a P. aeruginosa biofilm using a PPA3309-gfp (green fluorescent protein gene) fusion and confocal laser-scanning microscopy. This is the first description of an Anr-dependent, anaerobically induced, and functional Usp-like protein in bacteria....... the induced synthesis of three enzymes involved in arginine fermentation, ArcA, ArcB, and ArcC, and the outer membrane protein OprL. Moreover, formation of two proteins of unknown function, PA3309 and PA4352, increased by factors of 72- and 22-fold, respectively. Both belong to the group of universal stress...... proteins (Usp). Long-term survival of a PA3309 knockout mutant by pyruvate fermentation was found drastically reduced. The oxygen-sensing regulator Anr controls expression of the PPA3309-lacZ reporter gene fusion after a shift to anaerobic conditions and further pyruvate fermentation. PA3309 expression...

  20. Combined neonicotinoid pesticide and parasite stress alter honeybee queens’ physiology and survival

    Science.gov (United States)

    Dussaubat, Claudia; Maisonnasse, Alban; Crauser, Didier; Tchamitchian, Sylvie; Bonnet, Marc; Cousin, Marianne; Kretzschmar, André; Brunet, Jean-Luc; Le Conte, Yves

    2016-01-01

    Honeybee colony survival strongly relies on the queen to overcome worker losses exposed to combined stressors like pesticides and parasites. Queen’s capacity to withstand these stressors is however very little known. The effects of the common neonicotinoid pesticide imidacloprid in a chronic and sublethal exposure together with the wide distributed parasite Nosema ceranae have therefore been investigated on queen’s physiology and survivorship in laboratory and field conditions. Early physiological changes were observed on queens, particularly the increase of enzyme activities (catalase [CAT] and glutathione-S-transferase [GST] in the heads) related to protective responses to xenobiotics and oxidative stress against pesticide and parasite alone or combined. Stressors also alter the activity of two other enzymes (carboxylesterase alpha [CaE α] and carboxylesterase para [CaE p] in the midguts) involved in metabolic and detoxification functions. Furthermore, single and combined effects of pesticide and parasite decrease survivorship of queens introduced into mating hives for three months. Because colony demographic regulation relies on queen’s fertility, the compromise of its physiology and life can seriously menace colony survival under pressure of combined stressors. PMID:27578396

  1. Honey bee (Apis mellifera) drones survive oxidative stress due to increased tolerance instead of avoidance or repair of oxidative damage.

    Science.gov (United States)

    Li-Byarlay, Hongmei; Huang, Ming Hua; Simone-Finstrom, Michael; Strand, Micheline K; Tarpy, David R; Rueppell, Olav

    2016-10-01

    Oxidative stress can lead to premature aging symptoms and cause acute mortality at higher doses in a range of organisms. Oxidative stress resistance and longevity are mechanistically and phenotypically linked; considerable variation in oxidative stress resistance exists among and within species and typically covaries with life expectancy. However, it is unclear whether stress-resistant, long-lived individuals avoid, repair, or tolerate molecular damage to survive longer than others. The honey bee (Apis mellifera L.) is an emerging model system that is well-suited to address this question. Furthermore, this species is the most economically important pollinator, whose health may be compromised by pesticide exposure, including oxidative stressors. Here, we develop a protocol for inducing oxidative stress in honey bee males (drones) via Paraquat injection. After injection, individuals from different colony sources were kept in common social conditions to monitor their survival compared to saline-injected controls. Oxidative stress was measured in susceptible and resistant individuals. Paraquat drastically reduced survival but individuals varied in their resistance to treatment within and among colony sources. Longer-lived individuals exhibited higher levels of lipid peroxidation than individuals dying early. In contrast, the level of protein carbonylation was not significantly different between the two groups. This first study of oxidative stress in male honey bees suggests that survival of an acute oxidative stressor is due to tolerance, not prevention or repair, of oxidative damage to lipids. It also demonstrates colony differences in oxidative stress resistance that might be useful for breeding stress-resistant honey bees. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Stress, sex, and plague: Patterns of developmental stress and survival in pre- and post-Black Death London.

    Science.gov (United States)

    DeWitte, Sharon N

    2017-10-26

    Previous research revealed declines in survivorship in London before the Black Death (c. 1346-1353), and improvements in survivorship following the epidemic. These trends indicate that there were declines in general levels of health before the Black Death and improvements thereof afterwards. This study expands on previous research by examining whether changes in survivorship were consistent between the sexes, and how patterns of developmental stress markers changed before and after the Black Death. This study uses samples from London cemeteries dated to one of three periods: Early Pre-Black Death (1000-1200 AD, n = 255), Late Pre-Black Death (1200-1250 AD, n = 247), or Post-Black Death (1350-1540 AD n = 329). Temporal trends in survivorship are assessed via Kaplan-Meier survival analysis, and trends in tibial length (as a proxy for stature) and linear enamel hypoplasia (LEH) are assessed using t-tests and Chi-square tests, respectively. Survivorship for both sexes decreased before the Black Death and increased afterwards. For males, LEH frequencies increased and stature decreased before the epidemic, and LEH declined and stature increased after the Black Death. For females, the only significant change with respect to developmental stress markers was a decrease in stature after the Black Death. These results might reflect variation between the sexes in sensitivity to stressors, the effects of nutrition on pubertal timing, disproportionate access to dietary resources for males in the aftermath of the Black Death, the disproportionate deaths of frail individuals during the epidemic, or some combination of these factors. © 2017 Wiley Periodicals, Inc.

  3. Survival of Listeria monocytogenes in simulated gastrointestinal system and transcriptional profiling of stress- and adhesion-related genes.

    Science.gov (United States)

    Jiang, Lingli; Olesen, Inger; Andersen, Thomas; Fang, Weihuan; Jespersen, Lene

    2010-03-01

    Food ingestion is the major route of exposure to the important human pathogen Listeria monocytogenes. An in vitro gastrointestinal model was used to (1) compare the survival rates of L. monocytogenes strains of serotypes 1/2a, 1/2c, and 4b; and (2) examine the transcription of stress- and adhesion-related genes after exposure to the conditions similar to those encountered in the mouth, stomach, and small intestine. None of the L. monocytogenes strains investigated could survive in the gastric juice at pH 2.5 or 3.0. Their survival increased at higher pH (3.5 and 4.0) in the gastric stress. Relative survival of L. monocytogenes serotypes 4b and 1/2a strains were higher than that of serotype 1/2c, suggesting that pathogenicity might be related to the viability in the gastrointestinal tract. The transcription levels of prfA and the general stress-related genes clpC, clpE, and clpP were upregulated after passing through the simulated gastrointestinal tract, whereas that of the adhesion-related gene ami was downregulated. Taken together, this study revealed that L. monocytogenes strains enhanced the expression of stress-related genes and decreased the transcription of adhesion-related gene in order to survive in the diverse microenvironments.

  4. Brucella suis vaccine strain S2-infected immortalized caprine endometrial epithelial cell lines induce non-apoptotic ER-stress

    OpenAIRE

    Wang, Xiangguo; Lin, Pengfei; Yin, Yanlong; Zhou, Jinhua; Lei, Lanjie; Zhou, Xudong; Jin, Yaping; WANG, Aihua

    2015-01-01

    Brucella, which is regarded as an intracellular pathogen responsible for a zoonotic disease called brucellosis, survives and proliferates within several types of phagocytic and non-phagocytic cells. Brucella infects not only their preferred hosts but also other domestic and wild animal species, inducing abortion and infertility. Therefore, the interaction between uterine cells and Brucella is important for understanding the pathogenesis of this disease. In this study, we describe the Brucella...

  5. ADF and Cofilin1 Control Actin Stress Fibers, Nuclear Integrity, and Cell Survival.

    Science.gov (United States)

    Kanellos, Georgios; Zhou, Jing; Patel, Hitesh; Ridgway, Rachel A; Huels, David; Gurniak, Christine B; Sandilands, Emma; Carragher, Neil O; Sansom, Owen J; Witke, Walter; Brunton, Valerie G; Frame, Margaret C

    2015-12-01

    Genetic co-depletion of the actin-severing proteins ADF and CFL1 triggers catastrophic loss of adult homeostasis in multiple tissues. There is impaired cell-cell adhesion in skin keratinocytes with dysregulation of E-cadherin, hyperproliferation of differentiated cells, and ultimately apoptosis. Mechanistically, the primary consequence of depleting both ADF and CFL1 is uncontrolled accumulation of contractile actin stress fibers associated with enlarged focal adhesions at the plasma membrane, as well as reduced rates of membrane protrusions. This generates increased intracellular acto-myosin tension that promotes nuclear deformation and physical disruption of the nuclear lamina via the LINC complex that normally connects regulated actin filaments to the nuclear envelope. We therefore describe a pathway involving the actin-severing proteins ADF and CFL1 in regulating the dynamic turnover of contractile actin stress fibers, and this is vital to prevent the nucleus from being damaged by actin contractility, in turn preserving cell survival and tissue homeostasis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Effects of heat stress on survival of Frankliniella occidentalis (Thysanoptera: Thripidae) and Thrips tabaci (Thysanoptera: Thripidae).

    Science.gov (United States)

    Wang, J C; Zhang, B; Wang, J P; Li, H G; Wang, S F; Sun, L J; Zheng, C Y

    2014-08-01

    Temperature is known to play a crucial role in the population dynamics of insects. Insects have evolved different mechanisms to resist unfavorable extreme temperatures. In recent years, western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), and onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), have caused significant damage to vegetable crops. Because of global warming and expanding areas of vegetable cultivation, a study of the effects of heat stress on these thrips species is warranted. We exposed the various developmental stages of western flower thrips and onion thrips to temperatures of 41, 43, or 45 degrees C for 2, 6, 12, 24, or 36 h to determine the effects of heat stress on survival. Our results showed that the heat resistance of nonadult western flower thrips was greater than that of the nonadult onion thrips, and that the natural heat resistant ability was the primary factor in heat resistance in western flower thrips. In contrast, the heat resistance of adult onion thrips was greater than that of the adult western flower thrips, which was primarily the result of the ability of searching suitable microenvironment that enabled the onion thrips to mitigate the effects of high temperatures more efficiently than the western flower thrips. Our analysis of the differences in heat resistance between western flower thrips and onion thrips provides important information for the development of thermal treatments for controlling western flower thrips and onion thrips.

  7. Stress Survival Islet 2, Predominantly Present in Listeria monocytogenes Strains of Sequence Type 121, Is Involved in the Alkaline and Oxidative Stress Responses

    Science.gov (United States)

    Harter, Eva; Wagner, Eva Maria; Zaiser, Andreas; Halecker, Sabrina; Wagner, Martin

    2017-01-01

    ABSTRACT The foodborne pathogen Listeria monocytogenes is able to survive a variety of stress conditions leading to the colonization of different niches like the food processing environment. This study focuses on the hypervariable genetic hot spot lmo0443 to lmo0449 haboring three inserts: the stress survival islet 1 (SSI-1), the single-gene insert LMOf2365_0481, and two homologous genes of the nonpathogenic species Listeria innocua: lin0464, coding for a putative transcriptional regulator, and lin0465, encoding an intracellular PfpI protease. Our prevalence study revealed a different distribution of the inserts between human and food-associated isolates. The lin0464-lin0465 insert was predominantly found in food-associated strains of sequence type 121 (ST121). Functional characterization of this insert showed that the putative PfpI protease Lin0465 is involved in alkaline and oxidative stress responses but not in acidic, gastric, heat, cold, osmotic, and antibiotic stresses. In parallel, deletion of lin0464 decreased survival under alkaline and oxidative stresses. The expression of both genes increased significantly under oxidative stress conditions independently of the alternative sigma factor σB. Furthermore, we showed that the expression of the protease gene lin0465 is regulated by the transcription factor lin0464 under stress conditions, suggesting that lin0464 and lin0465 form a functional unit. In conclusion, we identified a novel stress survival islet 2 (SSI-2), predominantly present in L. monocytogenes ST121 strains, beneficial for survival under alkaline and oxidative stresses, potentially supporting adaptation and persistence of L. monocytogenes in food processing environments. IMPORTANCE Listeria monocytogenes strains of ST121 are known to persist for months and even years in food processing environments, thereby increasing the risk of food contamination and listeriosis. However, the molecular mechanism underlying this remarkable niche

  8. Stress Survival Islet 2, Predominantly Present in Listeria monocytogenes Strains of Sequence Type 121, Is Involved in the Alkaline and Oxidative Stress Responses.

    Science.gov (United States)

    Harter, Eva; Wagner, Eva Maria; Zaiser, Andreas; Halecker, Sabrina; Wagner, Martin; Rychli, Kathrin

    2017-08-15

    The foodborne pathogen Listeria monocytogenes is able to survive a variety of stress conditions leading to the colonization of different niches like the food processing environment. This study focuses on the hypervariable genetic hot spot lmo0443 to lmo0449 haboring three inserts: the stress survival islet 1 (SSI-1), the single-gene insert LMOf2365_0481, and two homologous genes of the nonpathogenic species Listeria innocua: lin0464, coding for a putative transcriptional regulator, and lin0465, encoding an intracellular PfpI protease. Our prevalence study revealed a different distribution of the inserts between human and food-associated isolates. The lin0464-lin0465 insert was predominantly found in food-associated strains of sequence type 121 (ST121). Functional characterization of this insert showed that the putative PfpI protease Lin0465 is involved in alkaline and oxidative stress responses but not in acidic, gastric, heat, cold, osmotic, and antibiotic stresses. In parallel, deletion of lin0464 decreased survival under alkaline and oxidative stresses. The expression of both genes increased significantly under oxidative stress conditions independently of the alternative sigma factor σB Furthermore, we showed that the expression of the protease gene lin0465 is regulated by the transcription factor lin0464 under stress conditions, suggesting that lin0464 and lin0465 form a functional unit. In conclusion, we identified a novel stress survival islet 2 (SSI-2), predominantly present in L. monocytogenes ST121 strains, beneficial for survival under alkaline and oxidative stresses, potentially supporting adaptation and persistence of L. monocytogenes in food processing environments.IMPORTANCEListeria monocytogenes strains of ST121 are known to persist for months and even years in food processing environments, thereby increasing the risk of food contamination and listeriosis. However, the molecular mechanism underlying this remarkable niche-specific adaptation is still

  9. Modeling the survival responses of a multi-component biofilm to environmental stress

    Science.gov (United States)

    Carles Brangarí, Albert; Manzoni, Stefano; Sanchez-Vila, Xavier; Fernàndez-Garcia, Daniel

    2017-04-01

    Biofilms are consortia of microorganisms embedded in self-produced matrices of biopolymers. The survival of such communities depends on their capacity to improve the environmental conditions of their habitat by mitigating, or even benefitting from some adverse external factors. The mechanisms by which the microbial habitat is regulated remain mostly unknown. However, many studies have reported physiological responses to environmental stresses that include the release of extracellular polymeric substances (EPS) and the induction of a dormancy state. A sound understanding of these capacities is required to enhance the knowledge of the microbial dynamics in soils and its potential role in the carbon cycle, with significant implications for the degradation of contaminants and the emission of greenhouse gases, among others. We present a numerical analysis of the dynamics of soil microbes and their responses to environmental stresses. The conceptual model considers a multi-component heterotrophic biofilm made up of active cells, dormant cells, EPS, and extracellular enzymes. Biofilm distribution and properties are defined at the pore-scale and used to determine nutrient availability and water saturation via feedbacks of biofilm on soil hydraulic properties. The pore space micro-habitat is modeled as a simplified pore-network of cylindrical tubes in which biofilms proliferate. Microbial compartments and most of the carbon fluxes are defined at the bulk level. Microbial processes include the synthesis, decay and detachment of biomass, the activation/deactivation of cells, and the release and reutilization of EPS. Results suggest that the release of EPS and the capacity to enter a dormant state offer clear evolutionary advantages in scenarios characterized by environmental stress. On the contrary, when the conditions are favorable, the diversion of carbon into the production of the aforementioned survival mechanisms does not confer any additional benefit and the population

  10. HBx regulates fatty acid oxidation to promote hepatocellular carcinoma survival during metabolic stress.

    Science.gov (United States)

    Wang, Ming-Da; Wu, Han; Huang, Shuai; Zhang, Hui-Lu; Qin, Chen-Jie; Zhao, Ling-Hao; Fu, Gong-Bo; Zhou, Xu; Wang, Xian-Ming; Tang, Liang; Wen, Wen; Yang, Wen; Tang, Shan-Hua; Cao, Dan; Guo, Lin-Na; Zeng, Min; Wu, Meng-Chao; Yan, He-Xin; Wang, Hong-Yang

    2016-02-09

    Due to a high rate of nutrient consumption and inadequate vascularization, hepatocellular carcinoma (HCC) cells constantly undergo metabolic stress during tumor development. Hepatitis B virus (HBV) X protein (HBx) has been implicated in the pathogenesis of HBV-induced HCC. In this study, we investigated the functional roles of HBx in HCC adaptation to metabolic stress. Up-regulation of HBx increased the intracellular ATP and NADPH generation, and induced the resistance to glucose deprivation, whereas depletion of HBx via siRNA abolished these effects and conferred HCC cells sensitive to glucose restriction. Though HBx did not affect the glycolysis and oxidative phosphorylation capacity of HCC cells under normal culture conditions, it facilitated fatty acid oxidation (FAO) in the absence of glucose, which maintained NADPH and ATP levels. Further investigation showed that HBx expression, under glucose deprivation, stimulated phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) via a calcium/CaMKK-dependent pathway, which was required for the activation of FAO. Conversely, inhibition of FAO by etomoxir (ETO) restored the sensitivity of HBx-expressing cells to glucose deficiency in vitro and retarded xenograft tumor formation in vivo. Finally, HBx-induced activation of the AMPK and FAO pathways were also observed in xenograft tumors and HBV-associated HCC specimens. Our data suggest that HBx plays a key role in the maintenance of redox and energy homeostasis by activating FAO, which is critical for HCC cell survival under conditions of metabolic stress and might be exploited for therapeutic benefit.

  11. Stress-induced nuclear RNA degradation pathways regulate yeast bromodomain factor 2 to promote cell survival.

    Directory of Open Access Journals (Sweden)

    Kevin Roy

    2014-09-01

    Full Text Available Bromodomain proteins are key regulators of gene expression. How the levels of these factors are regulated in specific environmental conditions is unknown. Previous work has established that expression of yeast Bromodomain factor 2 (BDF2 is limited by spliceosome-mediated decay (SMD. Here we show that BDF2 is subject to an additional layer of post-transcriptional control through RNase III-mediated decay (RMD. We found that the yeast RNase III Rnt1p cleaves a stem-loop structure within the BDF2 mRNA to down-regulate its expression. However, these two nuclear RNA degradation pathways play distinct roles in the regulation of BDF2 expression, as we show that the RMD and SMD pathways of the BDF2 mRNA are differentially activated or repressed in specific environmental conditions. RMD is hyper-activated by salt stress and repressed by hydroxyurea-induced DNA damage while SMD is inactivated by salt stress and predominates during DNA damage. Mutations of cis-acting signals that control SMD and RMD rescue numerous growth defects of cells lacking Bdf1p, and show that SMD plays an important role in the DNA damage response. These results demonstrate that specific environmental conditions modulate nuclear RNA degradation pathways to control BDF2 expression and Bdf2p-mediated gene regulation. Moreover, these results show that precise dosage of Bromodomain factors is essential for cell survival in specific environmental conditions, emphasizing their importance for controlling chromatin structure and gene expression in response to environmental stress.

  12. Stress-Induced Nuclear RNA Degradation Pathways Regulate Yeast Bromodomain Factor 2 to Promote Cell Survival

    Science.gov (United States)

    Roy, Kevin; Chanfreau, Guillaume

    2014-01-01

    Bromodomain proteins are key regulators of gene expression. How the levels of these factors are regulated in specific environmental conditions is unknown. Previous work has established that expression of yeast Bromodomain factor 2 (BDF2) is limited by spliceosome-mediated decay (SMD). Here we show that BDF2 is subject to an additional layer of post-transcriptional control through RNase III-mediated decay (RMD). We found that the yeast RNase III Rnt1p cleaves a stem-loop structure within the BDF2 mRNA to down-regulate its expression. However, these two nuclear RNA degradation pathways play distinct roles in the regulation of BDF2 expression, as we show that the RMD and SMD pathways of the BDF2 mRNA are differentially activated or repressed in specific environmental conditions. RMD is hyper-activated by salt stress and repressed by hydroxyurea-induced DNA damage while SMD is inactivated by salt stress and predominates during DNA damage. Mutations of cis-acting signals that control SMD and RMD rescue numerous growth defects of cells lacking Bdf1p, and show that SMD plays an important role in the DNA damage response. These results demonstrate that specific environmental conditions modulate nuclear RNA degradation pathways to control BDF2 expression and Bdf2p-mediated gene regulation. Moreover, these results show that precise dosage of Bromodomain factors is essential for cell survival in specific environmental conditions, emphasizing their importance for controlling chromatin structure and gene expression in response to environmental stress. PMID:25232960

  13. In utero heat stress decreases calf survival and performance through the first lactation.

    Science.gov (United States)

    Monteiro, A P A; Tao, S; Thompson, I M T; Dahl, G E

    2016-10-01

    Calves born to cows exposed to heat stress during late gestation (i.e., the dry period) have lower birth weight and weaning weight and compromised passive immune transfer compared with those born to dams that are cooled. However, it is unknown if heat stress in utero has carryover effects after weaning. The objective was to evaluate the effect of heat stress (HT) or cooling (CL) in late gestation dairy cows on the survival, growth, fertility, and milk production in the first lactation of their calves. Data of animals obtained from previous experiments conducted during 5 consecutive summers in Florida were pooled and analyzed. Cows were dried off 46d before expected calving and randomly assigned to 1 of 2 treatments, HT or CL. Cooled cows were housed with sprinklers, fans, and shade, whereas only shade was provided to HT cows. Within 4h of birth, 3.8 L of colostrum was fed to calves from both groups of cows. All calves were managed in the same manner and weaned at 49d of age. Birth weight and survival of 146 calves (HT=74; CL=72) were analyzed. Additionally, body weight, growth rate, fertility, and milk production in the first lactation from 72 heifers (HT=34; CL=38) were analyzed. As expected, HT calves were lighter (means ± SEM; 39.1±0.7 vs. 44.8±0.7kg) at birth than CL calves. Cooled heifers were heavier up to 1yr of age, but had similar total weight gain (means ± SEM; 305.8±6.3 vs. 299.1±6.3kg, respectively) compared with HT heifers. No effect of treatment was observed on age at first insemination (AI) and age at first parturition. Compared with CL heifers, HT heifers had a greater number of services per pregnancy confirmed at d 30 after AI, but no treatment effect was observed on number of services per pregnancy confirmed at d 50 after AI. A greater percentage of CL heifers reached first lactation compared with HT heifers (85.4 vs. 65.9%). Moreover, HT heifers produced less milk up to 35wk of the first lactation compared with CL heifers (means ± SEM; 26

  14. PERK induces resistance to cell death elicited by endoplasmic reticulum stress and chemotherapy.

    Science.gov (United States)

    Salaroglio, Iris C; Panada, Elisa; Moiso, Enrico; Buondonno, Ilaria; Provero, Paolo; Rubinstein, Menachem; Kopecka, Joanna; Riganti, Chiara

    2017-05-12

    Nutrient deprivation, hypoxia, radiotherapy and chemotherapy induce endoplasmic reticulum (ER) stress, which activates the so-called unfolded protein response (UPR). Extensive and acute ER stress directs the UPR towards activation of death-triggering pathways. Cancer cells are selected to resist mild and prolonged ER stress by activating pro-survival UPR. We recently found that drug-resistant tumor cells are simultaneously resistant to ER stress-triggered cell death. It is not known if cancer cells adapted to ER stressing conditions acquire a chemoresistant phenotype. To investigate this issue, we generated human cancer cells clones with acquired resistance to ER stress from ER stress-sensitive and chemosensitive cells. ER stress-resistant cells were cross-resistant to multiple chemotherapeutic drugs: such multidrug resistance (MDR) was due to the overexpression of the plasma-membrane transporter MDR related protein 1 (MRP1). Gene profiling analysis unveiled that cells with acquired resistance to ER stress and chemotherapy share higher expression of the UPR sensor protein kinase RNA-like endoplasmic reticulum kinase (PERK), which mediated the erythroid-derived 2-like 2 (Nrf2)-driven transcription of MRP1. Disrupting PERK/Nrf2 axis reversed at the same time resistance to ER stress and chemotherapy. The inducible silencing of PERK reduced tumor growth and restored chemosensitivity in resistant tumor xenografts. Our work demonstrates for the first time that the adaptation to ER stress in cancer cells produces a MDR phenotype. The PERK/Nrf2/MRP1 axis is responsible for the resistance to ER stress and chemotherapy, and may represent a good therapeutic target in aggressive and resistant tumors.

  15. Auranofin induces apoptosis by ROS-mediated ER stress and mitochondrial dysfunction and displayed synergistic lethality with piperlongumine in gastric cancer.

    Science.gov (United States)

    Zou, Peng; Chen, Minxiao; Ji, Jiansong; Chen, Weiqian; Chen, Xi; Ying, Shilong; Zhang, Junru; Zhang, Ziheng; Liu, Zhiguo; Yang, Shulin; Liang, Guang

    2015-11-03

    Gastric cancer (GC) is one of the leading causes of cancer mortality in the world. In addressing the need of treatments for relapsed disease, we report the identification of an existing U.S. Food and Drug Administration-approved small-molecule drug to repurpose for GC treatment. Auranofin (AF), clinically used to treat rheumatic arthritis, but it exhibited preclinical efficacy in GC cells. By increasing intracellular reactive oxygen species (ROS) levels, AF induces a lethal endoplasmic reticulum stress response and mitochondrial dysfunction in cultured GC cells. Blockage of ROS production reversed AF-induced ER stress and mitochondrial pathways activation as well as apoptosis. In addition, AF displays synergistic lethality with an ROS-generating agent piperlongumine, which is a natural product isolated from the long pepper Piper longum L. Taken together, this work provides a novel anticancer candidate for the treatment of gastric cancer. More importantly, it reveals that increased ROS generation might be an effective strategy in treating human gastric cancer.

  16. 9-Norbornyl-6-chloropurine (NCP) induces cell death through GSH depletion-associated ER stress and mitochondrial dysfunction

    Czech Academy of Sciences Publication Activity Database

    Plačková, Pavla; Šála, Michal; Šmídková, Markéta; Dejmek, Milan; Hřebabecký, Hubert; Nencka, Radim; Thibaut, H. J.; Neyts, J.; Mertlíková-Kaiserová, Helena

    2016-01-01

    Roč. 97, Aug (2016), s. 223-235 ISSN 0891-5849 R&D Projects: GA MŠk LO1302; GA ČR GAP303/11/1297 Institutional support: RVO:61388963 Keywords : glutathione-S-transferase * oxidative stress * leukemia Subject RIV: CE - Biochemistry Impact factor: 5.606, year: 2016 http://www.sciencedirect.com/science/article/pii/S0891584916302921

  17. Anoxic or aerial survival of bivalves and other euryoxic invertebrates as a useful response to environmental stress - A comprehensive review

    NARCIS (Netherlands)

    De Zwaan, A.; Eertman, R.H.M.

    1996-01-01

    Laboratory and field studies have demonstrated the applicability of anoxic/aerial survival as an early warning indicator of contaminant induced stress. The effects of xenobiotics, including heavy metals, organometals and organics as well as contaminated field sediments have been investigated. The

  18. "Survival in air" of the blue mussel Mytilus edulis L. as a sensitive response to pollution-induced environmental stress

    NARCIS (Netherlands)

    Eertman, R.H.M.; Wagenvoort, A.J.; Hummel, H.; Smaal, A.C.

    1993-01-01

    Mussels, Mytilus edulis, were exposed for periods of 6 weeks at various locations in Dutch coastal waters during 1989 and 1990. “Survival in air” showed to be a sensitive response parameter for indicating pollution induced environmental stress in transplanted mussels sampled from eight field sites.

  19. Device Survival after Primary Implantation of an Artificial Urinary Sphincter for Male Stress Urinary Incontinence.

    Science.gov (United States)

    Yafi, Faysal A; DeLay, Kenneth J; Stewart, Carrie; Chiang, Jason; Sangkum, Premsant; Hellstrom, Wayne J G

    2017-03-01

    The AMS 800™ artificial urinary sphincter remains the gold standard for the surgical management of male stress urinary incontinence. We reviewed artificial urinary sphincter device survival after primary implantation. Retrospective data were collected from the AMS 800 patient information form database. Since 1972, 77,512 patient information forms for primary artificial urinary sphincter implantation have been completed in the United States. Following exclusion of procedures performed in children and females, and those labeled with an unknown surgical technique, 27,096 artificial urinary sphincter cases were included in the analysis. Collected variables included patient age, surgical approach, number of cuffs and surgeon volume. Measured outcomes included device explantation, device revision, component revision and time to each event. Artificial urinary sphincter insertion was performed by low volume implanters in 22,165 (82.6%) cases. The approach was perineal in 18,373 cases (67.8%) and a tandem cuff was used in 2,224 cases (8.2%). Overall 5,723 cases required revision or explantation (21.1%). Younger age and penoscrotal approach were associated with higher device explantation and revision rates, while the use of a tandem cuff was associated with higher explantation rates. On multivariate analysis younger age, penoscrotal approach and use of a tandem cuff but not surgeon volume were significant factors associated with device explantation and component revision. These data provide a general overview of artificial urinary sphincter device survival and may serve urologists when counseling patients. Younger age, penoscrotal approach and use of a tandem cuff may be associated with inferior outcomes. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  20. Litopenaeus vannamei activating transcription factor 6 alpha gene involvement in ER-stress response and white spot symptom virus infection.

    Science.gov (United States)

    Yuan, Kai; He, Hong-Hui; Zhang, Chao-Zheng; Li, Xiao-Yun; Weng, Shao-Ping; He, Jian-Guo; Chen, Yi-Hong

    2017-11-01

    A previous study found that inositol-requiring enzyme-1-X-box binding protein 1 (IRE1-XBP1) pathway and the protein kinase RNA (PKR)-like ER kinase-eIF2α (PERK-eIF2α) pathway of shrimp play roles in the unfolded protein response (UPR). And they also be proved that was involved in white spot symptom virus (WSSV) infection. Yet the functions of the third branch in shrimp UPR are still unclear. In this study, we showed that upon UPR activation, activating transcription factor 6 alpha (LvATF6α) of Litopenaeus vannamei was cleaved and transferred from the cytoplasm to the nucleus in 293T cells, indicating that the ATF6 pathway in shrimp is also a branch of UPR. Furthermore, LvATF6α could reduce the apoptosis rate of Drosophila Schneider 2 (S2) cells treated with actinomycin, and knock-down expression of LvATF6α increased the apoptosis rate of shrimp hemocytes. In vivo testing revealed that the short from LvATF6α (LvATF6α-s) was obviously increased after UPR activation or WSSV infection, indicating that the ATF6 pathway was activated in L. vannamei gills under such circumstances. Moreover, knock-down expression of LvATF6α could reduce the cumulative mortality and WSSV copy number in WSSV-infected shrimp. Further study revealed that WSSV may profit from shrimp ATF6 pathway activation in two aspects. First, LvATF6α-s significantly upregulated the expression of the WSSV genes (wsv023, wsv045, wsv083, wsv129, wsv222, wsv249, and wsv343). Second, LvATF6α-s inhibited apoptosis by negatively regulating the apoptosis signal-regulating kinase 1 - (c-Jun N-terminal kinase) pathway. All of these evidences suggested that the ATF6 pathway is a member of the L. vannamei UPR, and it is also engaged in WSSV infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Selenium deficiency aggravates T-2 toxin-induced injury of primary neonatal rat cardiomyocytes through ER stress.

    Science.gov (United States)

    Xu, Jing; Pan, Shengchi; Gan, Fang; Hao, Shu; Liu, Dandan; Xu, Haibin; Huang, Kehe

    2018-02-16

    Keshan disease is a potentially fatal cardiomyopathy in humans. Selenium deficiency, T-2 toxin, and myocarditis virus are thought to be the major factors contributing to Keshan disease. But the relationship among these three factors is poorly described. This study aims to explore whether selenium deficiency aggravates T-2 toxin-induced cardiomyocyte injury and its underlying mechanism. Cardiomyocytes were isolated from neonatal rat and cultured at the physiological (2.0 μM) or lower concentrations of selenium with different concentrations of T-2 toxin. Our results showed that selenium deficiencies aggravated T-2 toxin-induced cardiomyocyte injury in a concentration-dependent manner as demonstrated by MTT bioassay, LDH activity, reactive oxygen species levels and caspase 3 protein expressions. T-2 toxin treatment significantly increased mRNA expressions for stress proteins GRP78 and CHOP in cardiomyocytes compared with the control. Selenium deficiencies further promoted GRP78, CHOP and p-eIF2α expressions. Knockdown of CHOP by the specific small interfering RNA eliminated the effect of selenium deficiencies on T-2 toxin-induced injury. It could be concluded that selenium deficiency aggravates T-2 toxin-induced cardiomyocyte injury through initiating more aggressive endoplasmic reticulum stress. Copyright © 2018. Published by Elsevier B.V.

  2. Parkin elimination of mitochondria is important for maintenance of lens epithelial cell ROS levels and survival upon oxidative stress exposure.

    Science.gov (United States)

    Brennan, Lisa; Khoury, Josef; Kantorow, Marc

    2017-01-01

    Age-related cataract is associated with oxidative stress and death of lens epithelial cells (LECs) whose survival is dependent on functional mitochondrial populations. Oxidative stress-induced depolarization/damage of LEC mitochondria results in increased reactive oxygen species (ROS) levels and cell death suggesting the need for a LEC mechanism to remove mitochondria depolarized/damaged upon oxidative stress exposure to prevent ROS release and LEC death. To date, a mechanism(s) for removal of depolarized/damaged LEC mitochondria has yet to be identified and the importance of eliminating oxidative stress-damaged mitochondria to prevent LEC ROS release and death has not been established. Here, we demonstrate that Parkin levels increase in LECs exposed to H2O2-oxidative stress. We establish that Parkin translocates to LEC mitochondria depolarized upon oxidative stress exposure and that Parkin recruits p62/SQSTM1 to depolarized LEC mitochondria. We demonstrate that translocation of Parkin results in the elimination of depolarized/damaged mitochondria and that Parkin clearance of LEC mitochondria is dependent on its ubiquitin ligase activity. Importantly, we demonstrate that Parkin elimination of damaged LEC mitochondria results in reduced ROS levels and increased survival upon oxidative stress exposure. These results establish that Parkin functions to eliminate LEC mitochondria depolarized/damaged upon oxidative stress exposure and that elimination of damaged mitochondria by Parkin is important for LEC homeostasis and survival. The data also suggest that mitochondrial quality control by Parkin could play a role in lens transparency. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Post-traumatic stress disorder in Polish stroke patients who survived Nazi concentration camps.

    Science.gov (United States)

    Pachalska, Maria; Grochmal-Bach, Bozena; MacQueen, Bruce Duncan; Frańczuk, Bogusław

    2006-04-01

    Many persons who survived Nazi concentration camps are now in advanced age, so that rehabilitation centers in Poland are seeing increasing numbers of such patients, especially after strokes. In many cases, the process of rehabilitation is severely hampered by Post-Traumatic Stress Disorder (PTSD), while the neuropsychological consequences of the stroke itself often evoke traumatic memories and simultaneously disorganize or destroy the patient's previous coping mechanisms. The present study describes the program developed by the authors for concentration camp survivors in post-stroke rehabilitation, including the use of art therapy and specially prepared films to help the patients cope with PTSD. The experimental group (KL) consisted of 8 such patients (4 men, 4 women, average age 79.1+/-4.28) with mild post-stroke aphasia who went through the PTSD program, while the comparison group (C) included 8 post-stroke patients, matched for age and gender, who were not concentration camp survivors and showed no premorbid symptoms of PTSD. All subjects were tested at baseline and again 3 months later, using structured interview and observation, self-rating scales for three basic negative emotions (anger, anxiety and sadness) and the Frustration and Aggression Test for the Disabled. The results showed significant differences between the groups at baseline, while at follow-up the differences between groups had changed in both extent and distribution. Qualitative analysis of the results allows for some important observations about the etiology and course of PTSD in these persons.

  4. Insight into post-transcriptional gene regulation: stress-responsive microRNAs and their role in the environmental stress survival of tolerant animals.

    Science.gov (United States)

    Biggar, Kyle K; Storey, Kenneth B

    2015-05-01

    Living animals are constantly faced with various environmental stresses that challenge normal life, including: oxygen limitation, very low or high temperature, as well as restriction of water and food. It has been well established that in response to these stresses, tolerant organisms regularly respond with a distinct suite of cellular modifications that involve transcriptional, translational and post-translational modification. In recent years, a new mechanism of rapid and reversible transcriptome regulation, via the action of non-coding RNA molecules, has emerged into post-transcriptional regulation and has since been shown to be part of the survival response. However, these RNA-based mechanisms by which tolerant organisms respond to stressed conditions are not well understood. Recent studies have begun to show that non-coding RNAs control gene expression and translation of mRNA to protein, and can also have regulatory influence over major cellular processes. For example, select microRNAs have been shown to have regulatory influence over the cell cycle, apoptosis, signal transduction, muscle atrophy and fatty acid metabolism during periods of environmental stress. As we are on the verge of dissecting the roles of non-coding RNA in environmental stress adaptation, this Commentary summarizes the hallmark alterations in microRNA expression that facilitate stress survival. © 2015. Published by The Company of Biologists Ltd.

  5. Compartmental stress responses correlate with cell survival in bystander effects induced by the DNA damage agent, bleomycin.

    Science.gov (United States)

    Savu, Diana; Petcu, Ileana; Temelie, Mihaela; Mustaciosu, Cosmin; Moisoi, Nicoleta

    2015-01-01

    Physical or chemical stress applied to a cell system trigger a signal cascade that is transmitted to the neighboring cell population in a process known as bystander effect. Despite its wide occurrence in biological systems this phenomenon is mainly documented in cancer treatments. Thus understanding whether the bystander effect acts as an adaptive priming element for the neighboring cells or a sensitization factor is critical in designing treatment strategies. Here we characterize the bystander effects induced by bleomycin, a DNA-damaging agent, and compartmental stress responses associated with this phenomenon. Mouse fibroblasts were treated with increasing concentrations of bleomycin and assessed for DNA damage, cell death and induction of compartmental stress response (endoplasmic reticulum, mitochondrial and cytoplasmic stress). Preconditioned media were used to analyze bystander damage using the same end-points. Bleomycin induced bystander response was reflected primarily in increased DNA damage. This was dependent on the concentration of bleomycin and time of media conditioning. Interestingly, we found that ROS but not NO are involved in the transmission of the bystander effect. Consistent transcriptional down-regulation of the stress response factors tested (i.e. BiP, mtHsp60, Hsp70) occurred in the direct effect indicating that bleomycin might induce an arrest of transcription correlated with decreased survival. We observed the opposite trend in the bystander effect, with specific stress markers appearing increased and correlated with increased survival. These data shed new light on the potential role of stress pathways activation in bystander effects and their putative impact on the pro-survival pro-death balance. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  6. Survival and weight change among adult individuals of Periplaneta americana (Linnaeus, 1758 (Blattaria, Blattidae subject to various stress conditions

    Directory of Open Access Journals (Sweden)

    Jucelio Peter Duarte

    2015-03-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n2p103 Periplaneta americana is a species of great importance to public health, since it can act as a vector of many pathogens and it reaches large populations in urban environments. This is probably due to its ability to resist starvation and desiccation. This study aimed to evaluate the effects of absence of water and food on survival and weight change among adult P. americana individuals and check whether the initial weight of individuals influences on their survival. Four groups having twenty P. americana couples were formed and subject to: I no water or food; II no food; III no water; and IV control group. Insects were isolated according to the groups, which were weighed at the beginning and end of the stress conditions. They remained under these conditions until all individuals in each test group were dead. Stress conditions caused reduction in survival time when compared to the control group. Adults with higher body mass survived longer when deprived only of food, while among those lacking water, weight had no influence on survival. Total weight loss was greater among individuals deprived of water than those deprived only of food.

  7. Branched-chain amino acid supplementation reduces oxidative stress and prolongs survival in rats with advanced liver cirrhosis.

    Directory of Open Access Journals (Sweden)

    Motoh Iwasa

    Full Text Available Long-term supplementation with branched-chain amino acids (BCAA is associated with prolonged survival and decreased frequency of development of hepatocellular carcinoma (HCC in patients with liver cirrhosis. However, the pharmaceutical mechanism underlying this association is still unclear. We investigated whether continuous BCAA supplementation increases survival rate of rats exposed to a fibrogenic agent and influences the iron accumulation, oxidative stress, fibrosis, and gluconeogenesis in the liver. Further, the effects of BCAA on gluconeogenesis in cultured cells were also investigated. A significant improvement in cumulative survival was observed in BCAA-supplemented rats with advanced cirrhosis compared to untreated rats with cirrhosis (P<0.05. The prolonged survival due to BCAA supplementation was associated with reduction of iron contents, reactive oxygen species production and attenuated fibrosis in the liver. In addition, BCAA ameliorated glucose metabolism by forkhead box protein O1 pathway in the liver. BCAA prolongs survival in cirrhotic rats and this was likely the consequences of reduced iron accumulation, oxidative stress and fibrosis and improved glucose metabolism in the liver.

  8. Costunolide, an active sesquiterpene lactone, induced apoptosis via ROS-mediated ER stress and JNK pathway in human U2OS cells.

    Science.gov (United States)

    Zhang, Chao; Lu, Tan; Wang, Guo-Dong; Ma, Chao; Zhou, Ying-Feng

    2016-05-01

    Costunolide, an active sesquiterpene lactone, is derived from many herbal medicines and it exhibits a broad spectrum of bioactivities such as anti-inflammatory, potential anti-tumor activity. Herein we assessed the anti-cancer effects of costunolide on U2OS cells and explored the underlying molecular mechanisms. The experiment data show that Costunolide exhibited significant anti-tumor activity by apoptosis related assays including Annexin V-FITC/PI flow cytometric analysis and 4,6-diamino-2-phenyl indole (DAPI) staining morphological analysis. Furthermore, we found Costunolide induced the loss of mitochondrial transmembrane potential, down-regulated Bcl-2/Bax ratio, encouraged Cyt-c release and caspase activation. All those effects are contributed by reactive oxygen species (ROS) generation and ER stress-induced mitochondrial dysfunction which are also responsible for c-Jun N-terminal kinase (JNK) activation. After the treatment of JNK inhibitor SP600125, it obviously reversed costunolide-induced apoptosis. Given N-acetyl-l-cysteine (NAC) effectively blocked the activation of JNK. Taken together, our results demonstrate that costunolide induces apoptosis in human U2OS cells through ROS generation and p38 MAPK/JNK activation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. Hericium erinaceus mycelium and its isolated erinacine A protection from MPTP-induced neurotoxicity through the ER stress, triggering an apoptosis cascade.

    Science.gov (United States)

    Kuo, Hsing-Chun; Lu, Chien-Chang; Shen, Chien-Heng; Tung, Shui-Yi; Hsieh, Meng Chiao; Lee, Ko-Chao; Lee, Li-Ya; Chen, Chin-Chu; Teng, Chih-Chuan; Huang, Wen-Shih; Chen, Te-Chuan; Lee, Kam-Fai

    2016-03-18

    Hericium erinaceus is an edible mushroom; its various pharmacological effects which have been investigated. This study aimed to demonstrate whether efficacy of oral administration of H. erinaceus mycelium (HEM) and its isolated diterpenoid derivative, erinacine A, can act as an anti-neuroinflammatory agent to bring about neuroprotection using an MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) mouse model of Parkinson's disease, which results in motor disturbances, in addition to elucidating the mechanisms involved. Mice were treated with and without HEM or erinacine A, after MPTP injection for brain injuries by the degeneration of dopaminergic nigrostriatal neurons. The efficacy of oral administration of HEM improved MPTP-induced loss of tyrosine hydroxylase positive neurons and brain impairment in the substantia nigra pars compacta as measured by brain histological examination. Treatment with HEM reduced MPTP-induced dopaminergic cell loss, apoptotic cell death induced by oxidative stress, as well as the level of glutathione, nitrotyrosine and 4-hydroxy-2-nonenal (4-HNE). Furthermore, HEM reversed MPTP-associated motor deficits, as revealed by the analysis of rotarod assessment. Our results demonstrated that erinacine A decreases the impairment of MPP-induced neuronal cell cytotoxicity and apoptosis, which were accompanied by ER stress-sustained activation of the IRE1α/TRAF2, JNK1/2 and p38 MAPK pathways, the expression of C/EBP homologous protein (CHOP), IKB-β and NF-κB, as well as Fas and Bax. These physiological and brain histological changes provide HEM neuron-protective insights into the progression of Parkinson's disease, and this protective effect seems to exist both in vivo and in vitro.

  10. Prenatal Stress Exposure Generates Higher Early Survival and Smaller Size without Impacting Developmental Rate in a Pacific Salmon.

    Science.gov (United States)

    Capelle, Pauline M; Semeniuk, Christina A D; Sopinka, Natalie M; Heath, John W; Love, Oliver P

    2016-12-01

    Prenatal exposure to elevated glucocorticoids can act as a signal of environmental stress, resulting in modifications to offspring phenotype. While "negative" phenotypic effects (i.e., smaller size, slower growth) are often reported, recent research coupling phenotype with other fitness-related traits has suggested positive impacts of prenatal stress. Using captive Chinook salmon (Oncorhynchus tshawytscha), we treated eggs with biologically relevant cortisol levels-low (300 ng mL(-1) ), high (1,000 ng mL(-1) ), or control (0 ng mL(-1) )-to examine the early-life impacts of maternally transferred stress hormones on offspring. Specifically, we measured early survival, rate of development, and multiple measures of morphology. Low and high cortisol dosing of eggs resulted in significantly higher survival compared to controls (37% and 24% higher, respectively). Fish reared from high dose eggs were structurally smaller compared to control fish, but despite this variation in structural size, exposure to elevated cortisol did not impact developmental rate. These results demonstrate that elevations in egg cortisol can positively influence offspring fitness through an increase in early survival while also altering phenotype at a critical life-history stage. Overall, these results suggest that exposure to prenatal stress may not always produce apparently negative impacts on offspring fitness and further proposes that complex phenotypic responses should be examined in relevant environmental conditions. © 2017 Wiley Periodicals, Inc.

  11. Endoplasmic reticulum (ER stress inducible factor cysteine-rich with EGF-like domains 2 (Creld2 is an important mediator of BMP9-regulated osteogenic differentiation of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Jiye Zhang

    Full Text Available Mesenchymal stem cells (MSCs are multipotent progenitors that can undergo osteogenic differentiation under proper stimuli. We demonstrated that BMP9 is one of the most osteogenic BMPs. However, the molecular mechanism underlying BMP9-initiated osteogenic signaling in MSCs remains unclear. Through gene expression profiling analysis we identified several candidate mediators of BMP9 osteogenic signaling. Here, we focus on one such signaling mediator and investigate the functional role of cysteine-rich with EGF-like domains 2 (Creld2 in BMP9-initiated osteogenic signaling. Creld2 was originally identified as an ER stress-inducible factor localized in the ER-Golgi apparatus. Our genomewide expression profiling analysis indicates that Creld2 is among the top up-regulated genes in BMP9-stimulated MSCs. We confirm that Creld2 is up-regulated by BMP9 in MSCs. ChIP analysis indicates that Smad1/5/8 directly binds to the Creld2 promoter in a BMP9-dependent fashion. Exogenous expression of Creld2 in MSCs potentiates BMP9-induced early and late osteogenic markers, and matrix mineralization. Conversely, silencing Creld2 expression inhibits BMP9-induced osteogenic differentiation. In vivo stem cell implantation assay reveals that exogenous Creld2 promotes BMP9-induced ectopic bone formation and matrix mineralization, whereas silencing Creld2 expression diminishes BMP9-induced bone formation and matrix mineralization. We further show that Creld2 is localized in ER and the ER stress inducers potentiate BMP9-induced osteogenic differentiation. Our results strongly suggest that Creld2 may be directly regulated by BMP9 and ER stress response may play an important role in regulating osteogenic differentiation.

  12. Progression of pathology in PINK1-deficient mouse brain from splicing via ubiquitination, ER stress, and mitophagy changes to neuroinflammation.

    Science.gov (United States)

    Torres-Odio, Sylvia; Key, Jana; Hoepken, Hans-Hermann; Canet-Pons, Júlia; Valek, Lucie; Roller, Bastian; Walter, Michael; Morales-Gordo, Blas; Meierhofer, David; Harter, Patrick N; Mittelbronn, Michel; Tegeder, Irmgard; Gispert, Suzana; Auburger, Georg

    2017-08-02

    ) human neuroblastoma cells with PINK1-knockdown and murine Pink1 -/- embryonal fibroblasts undergoing acute starvation, (4) triggering mitophagy in these cells with trifluoromethoxy carbonylcyanide phenylhydrazone (FCCP), and (5) subjecting them to pathogenic RNA-analogue poly(I:C). The stress regulation of MAVS, RSAD2, DDX58, IFIT3, IFIT1, and LRRK2 was PINK1 dependent. Dysregulation of some innate immunity genes was also found in skin fibroblast cells from PARK6 patients. Thus, an individual biomarker with expression correlating to progression was not identified. Instead, more advanced disease stages involved additional pathways. Hence, our results identify PINK1 deficiency as an early modulator of innate immunity in neurons, which precedes late stages of neuroinflammation during alpha-synuclein spreading.

  13. Survival and proliferation characteristics of the microalga Chlamydomonas sp. ICE-L after hypergravitational stress pretreatment

    Science.gov (United States)

    Gao, Zhengquan; Li, Demao; Meng, Chunxiao; Xu, Dong; Zhang, Xiaowen; Ye, Naihao

    2013-09-01

    Seeking extraterrestrial life, transferring between planets, even migrating to other planets attracts more and more attention of public and scientists. However, to make it clear for the ability to survive the forces studies is prerequisite to enable the speculations by natural means. Gravity is a critical force involved in all the life on Earth and, possibly, others planets. Organisms have been grown in microgravity habitats and in centrifuges to characterize the biological response to a range of gravitational forces and radiation levels in space and on Earth. However, little is known about the profiles of eukaryotic life under conditions of hyperacceleration attributable to extreme gravities. In this study, a eukaryotic extremophile, the Antarctic green microalga Chlamydomonas sp. ICE-L, showed amazing proliferation capacity during and after hypergravitational stress for 30 min to 48 h at 110,200, 423,400, and 670,800g. These extreme gravities also had profound effects on viability, reproduction rate, photosynthesis efficiency, and gene transcriptional expression of this microalga. Most notably, all three supergravities efficiently stimulated algal cell division, but the greater the centrifugal force and the longer the duration of treatment, the lower the viable rate and breeding potential of samples in the following incubation. These results illustrated Chlamydomonas sp. ICE-L is a useful eukaryotic model system candidate for space research. Further studies could provide new insight into the physical limits of life and its evolution and enhance the possibility for interstellar space travel and the quest for extraterrestrial life according to panspermia theory. Also, it indicated that life come from the outer space is not always prokaryotes but may be eukaryotes.

  14. Branched-Chain Amino Acid Supplementation Reduces Oxidative Stress and Prolongs Survival in Rats with Advanced Liver Cirrhosis

    Science.gov (United States)

    Mifuji-Moroka, Rumi; Hara, Nagisa; Miyachi, Hirohide; Sugimoto, Ryosuke; Tanaka, Hideaki; Fujita, Naoki; Gabazza, Esteban C.; Takei, Yoshiyuki

    2013-01-01

    Long-term supplementation with branched-chain amino acids (BCAA) is associated with prolonged survival and decreased frequency of development of hepatocellular carcinoma (HCC) in patients with liver cirrhosis. However, the pharmaceutical mechanism underlying this association is still unclear. We investigated whether continuous BCAA supplementation increases survival rate of rats exposed to a fibrogenic agent and influences the iron accumulation, oxidative stress, fibrosis, and gluconeogenesis in the liver. Further, the effects of BCAA on gluconeogenesis in cultured cells were also investigated. A significant improvement in cumulative survival was observed in BCAA-supplemented rats with advanced cirrhosis compared to untreated rats with cirrhosis (PBCAA supplementation was associated with reduction of iron contents, reactive oxygen species production and attenuated fibrosis in the liver. In addition, BCAA ameliorated glucose metabolism by forkhead box protein O1 pathway in the liver. BCAA prolongs survival in cirrhotic rats and this was likely the consequences of reduced iron accumulation, oxidative stress and fibrosis and improved glucose metabolism in the liver. PMID:23936183

  15. Hydric stress-dependent effects of Plasmodium falciparum infection on the survival of wild-caught Anopheles gambiae female mosquitoes

    Directory of Open Access Journals (Sweden)

    Aboagye-Antwi Fred

    2010-08-01

    Full Text Available Abstract Background Whether Plasmodium falciparum, the agent of human malaria responsible for over a million deaths per year, causes fitness costs in its mosquito vectors is a burning question that has not yet been adequately resolved. Understanding the evolutionary forces responsible for the maintenance of susceptibility and refractory alleles in natural mosquito populations is critical for understanding malaria transmission dynamics. Methods In natural mosquito populations, Plasmodium fitness costs may only be expressed in combination with other environmental stress factors hence this hypothesis was tested experimentally. Wild-caught blood-fed Anopheles gambiae s.s. females of the M and S molecular form from an area endemic for malaria in Mali, West Africa, were brought to the laboratory and submitted to a 7-day period of mild hydric stress or kept with water ad-libitum. At the end of this experiment all females were submitted to intense desiccation until death. The survival of all females throughout both stress episodes, as well as their body size and infection status was recorded. The importance of stress, body size and molecular form on infection prevalence and female survival was investigated using Logistic Regression and Proportional-Hazard analysis. Results Females subjected to mild stress exhibited patterns of survival and prevalence of infection compatible with increased parasite-induced mortality compared to non-stressed females. Fitness costs seemed to be linked to ookinetes and early oocyst development but not the presence of sporozoites. In addition, when females were subjected to intense desiccation stress, those carrying oocysts exhibited drastically reduced survival but those carrying sporozoites were unaffected. No significant differences in prevalence of infection and infection-induced mortality were found between the M and S molecular forms of Anopheles gambiae. Conclusions Because these results suggest that infected

  16. Major E. coli heat-stress protein do not translocate: implications for cell survival.

    Science.gov (United States)

    Yatvin, M B; Clark, A W; Siegel, F L

    1987-10-01

    When Escherichia coli are exposed to heat stress, the majority of proteins in the process of synthesis at the time of heat stress are rapidly translocated to the outer membrane of the bacterium. The synthesis of most of these proteins appears to take place on membrane-bound polyribosomes. With the temperature shift, overall protein synthesis is inhibited while the synthesis of a small group of proteins is initiated. These proteins are not translocated, but remain in the cytosolic compartment, and they are identifiable as heat-stress proteins. Both the translocation phenomenon and the retention of heat-stress proteins in the cytosolic compartment in proximity to the nucleoid could counteract the effects of heat stress. The translocated proteins may operate by stabilizing the outer membrane prior to the induction of heat-stress proteins and the latter, which are confined to the cytoplasmic compartment, may serve to protect the integrity of the nucleoid structures.

  17. Diversity of Survival Patterns among Escherichia coli O157:H7 Genotypes Subjected to Food-Related Stress Conditions.

    Science.gov (United States)

    Elhadidy, Mohamed; Álvarez-Ordóñez, Avelino

    2016-01-01

    The purpose of this study was to evaluate the resistance patterns to food-related stresses of Shiga toxin producing Escherichia coli O157:H7 strains belonging to specific genotypes. A total of 33 E. coli O157:H7 strains were exposed to seven different stress conditions acting as potential selective pressures affecting the transmission of E. coli O157:H7 to humans through the food chain. These stress conditions included cold, oxidative, osmotic, acid, heat, freeze-thaw, and starvation stresses. The genotypes used for comparison included lineage-specific polymorphism, Shiga-toxin-encoding bacteriophage insertion sites, clade type, tir (A255T) polymorphism, Shiga toxin 2 subtype, and antiterminator Q gene allele. Bacterial resistance to different stressors was calculated by determining D-values (times required for inactivation of 90% of the bacterial population), which were then subjected to univariate and multivariate analyses. In addition, a relative stress resistance value, integrating resistance values to all tested stressors, was calculated for each bacterial strain and allowed for a ranking-type classification of E. coli O157:H7 strains according to their environmental robustness. Lineage I/II strains were found to be significantly more resistant to acid, cold, and starvation stress than lineage II strains. Similarly, tir (255T) and clade 8 encoding strains were significantly more resistant to acid, heat, cold, and starvation stress than tir (255A) and non-clade 8 strains. Principal component analysis, which allows grouping of strains with similar stress survival characteristics, separated strains of lineage I and I/II from strains of lineage II, which in general showed reduced survival abilities. Results obtained suggest that lineage I/II, tir (255T), and clade 8 strains, which have been previously reported to be more frequently associated with human disease cases, have greater multiple stress resistance than strains of other genotypes. The results from this

  18. Contribution of protein isoaspartate methyl transferase (PIMT) in the survival of Salmonella Typhimurium under oxidative stress and virulence.

    Science.gov (United States)

    Kumawat, Manoj; Pesingi, Pavan Kumar; Agarwal, Rajesh Kumar; Goswami, Tapas Kumar; Mahawar, Manish

    2016-06-01

    The enteric pathogen Salmonella Typhimurium (ST) survives inside the oxidative environment of phagocytic cells. Phagocyte generated oxidants primarily target proteins and modify amino acids in them. These modifications render the targeted proteins functionally inactive. Conversion of Asp to iso-Asp is one of the several known oxidant mediated amino acids modifications. By repairing iso-Asp to Asp, protein-isoaspartyl methyltransferase (PIMT) maintains the activities of proteins and thus helps in cellular survival under oxidative stress. To elucidate the role of PIMT in ST survival under oxidative stress, we have constructed a pimt gene deletion strain (Δpimt strain) of ST. The Δpimt strain grows normally in various culture media in vitro. However, in comparison to wild type ST, the Δpimt strain is found significantly (psurvival of Δpimt mutant strain against oxidants in vitro and also inside the macrophages. In mice model, the LD50 for wild type ST and mutant Δpimt has been 1.73×10(4) and 1.38×10(5), respectively. Further, the mutant strain shows reduced dissemination to spleen and liver in mice. Following infection with a mixture of wild type ST and the Δpimt mutant (co-infection experiment), we recover significantly (p<0.001) less numbers of mutant bacteria from the spleen and liver of mice. Copyright © 2016 Elsevier GmbH. All rights reserved.

  19. The Role of Endoplasmic Reticulum Stress in Human Pathology

    Science.gov (United States)

    Oakes, Scott A.; Papa, Feroz R.

    2017-01-01

    Numerous genetic and environmental insults impede the ability of cells to properly fold and posttranslationally modify secretory and transmembrane proteins in the endoplasmic reticulum (ER), leading to a buildup of misfolded proteins in this organelle—a condition called ER stress. ER-stressed cells must rapidly restore protein-folding capacity to match protein-folding demand if they are to survive. In the presence of high levels of misfolded proteins in the ER, an intracellular signaling pathway called the unfolded protein response (UPR) induces a set of transcriptional and translational events that restore ER homeostasis. However, if ER stress persists chronically at high levels, a terminal UPR program ensures that cells commit to self-destruction. Chronic ER stress and defects in UPR signaling are emerging as key contributors to a growing list of human diseases, including diabetes, neurodegeneration, and cancer. Hence, there is much interest in targeting components of the UPR as a therapeutic strategy to combat these ER stress–associated pathologies. PMID:25387057

  20. The time dimension in stress responses : relevance for survival and health

    NARCIS (Netherlands)

    Eriksen, HR; Olff, M; Murison, R; Ursin, H

    1999-01-01

    Within the Cognitive Activation Theory of Stress (CATS), the stress response occurs whenever there is a discrepancy between what the organism is expecting, and what really exists. It affects the biochemistry of the brain, mobilizes resources, affects performance, and endocrine, vegetative, and

  1. The time dimension in stress responses: relevance for survival and health

    NARCIS (Netherlands)

    Eriksen, H. R.; Olff, M.; Murison, R.; Ursin, H.

    1999-01-01

    Within the Cognitive Activation Theory of Stress (CATS), the stress response occurs whenever there is a discrepancy between what the organism is expecting, and what really exists. It affects the biochemistry of the brain, mobilizes resources, affects performance, and endocrine, vegetative, and

  2. Effects of cadmium and a one-time drought stress on survival, growth, and yield of native plant species

    Energy Technology Data Exchange (ETDEWEB)

    Miles, L.J.; Parker, G.R.

    1980-04-01

    Andropogon scoparius, Monarda fistulosa, and Rudbeckia hirta were grown from seed for 6 weeks in an uncontaminated rural site soil and a heavy metal-contaminated urban site soil. The rural site soil was amended with cadmium chloride. Plants grown in both soils were subjected to a one-time drought stress. Survival, shoot weight, root weight, total weight, height, and weekly growth of Andropogon and Monarda were adversely affected by cadmium (Cd) addition and drought stress. Results were similar for Rudbeckia except that shoot, root, and total weight were not significantly affected by drought stress. Root weights of Monarda and Andropogon were more severely affected by Cd addition than were shoot weights. Root-shoot ratios were not significantly affected by drought stress for any species. Drought stress and Cd addition effects were found to be additive for Monarda and Andropogon. The effect of soil Cd addition on growth was found to be primarily due to an initial delay in growth rather than a reduction in the overall rate of growth. However, on the heavy metal contamination urban site soil the growth rate was found to be reduced. This was especially true for Andropogon which was found to be most tolerant of Cd addition to the rural site soil for the species tested. The reduction in growth rate of plants on the urban site soil was probably not due to Cd alone.

  3. The genome of the Antarctic polyextremophile Nesterenkonia sp. AN1 reveals adaptive strategies for survival under multiple stress conditions.

    Science.gov (United States)

    Aliyu, Habibu; De Maayer, Pieter; Cowan, Don

    2016-04-01

    Nesterenkonia sp. AN1 is a polyextremophile isolated from Antarctic desert soil. Genomic analyses and genome comparisons with three mesophilic Nesterenkonia strains indicated that the unique genome fraction of Nesterenkonia sp. AN1 contains adaptive features implicated in the response to cold stress including modulation of membrane fluidity as well as response to cold-associated osmotic and oxidative stress. The core genome also encodes a number of putative cold stress response proteins. RNA-Seq-based transcriptome analyses of Nesterenkonia sp. AN1 grown at 5ºC and 21°C showed that there was significant induction of transcripts that code for antioxidants at 5ºC, demonstrated by the upregulation of sodA, bcp and bpoA2. There was also overexpression of universal stress protein genes related to uspA, along with genes encoding other characterized cold stress features. Genes encoding the two key enzymes of the glyoxylate cycle, isocitrate lyase (ICL) and malate synthase (AceB) were induced at 5ºC, suggesting possible adaptation strategies for energy metabolism in cold habitats. These genomic features may contribute to the survival of Nesterenkonia sp. AN1 in arid Antarctic soils. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Sulfur mustard induces an endoplasmic reticulum stress response in the mouse ear vesicant model

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yoke-Chen; Wang, James D. [Rutgers University, Pharmacology and Toxicology, 170 Frelinghuysen Rd, Piscataway, NJ 08854 (United States); Svoboda, Kathy K. [Texas A and M University, Baylor College of Dentistry, Center for Craniofacial Research 3302 Gaston Ave, Dallas, Texas 75246 (United States); Casillas, Robert P. [MRIGlobal, 425 Volker Boulevard, Kansas City, MO 64110 (United States); Laskin, Jeffrey D. [UMDNJ-Robert Wood Johnson Medical School, Environmental and Occupational Medicine, 170 Frelinghuysen Rd, Piscataway, NJ 08854 (United States); Gordon, Marion K. [Rutgers University, Pharmacology and Toxicology, 170 Frelinghuysen Rd, Piscataway, NJ 08854 (United States); Gerecke, Donald R., E-mail: gerecke@eohsi.rutgers.edu [Rutgers University, Pharmacology and Toxicology, 170 Frelinghuysen Rd, Piscataway, NJ 08854 (United States)

    2013-04-15

    The endoplasmic reticulum (ER) stress response is a cell survival pathway upregulated when cells are under severe stress. Severely damaged mouse ear skin exposed to the vesicant, sulfur mustard (bis-2-chloroethyl sulfide, SM), resulted in increased expression of ER chaperone proteins that accompany misfolded and incorrectly made proteins targeted for degradation. Time course studies with SM using the mouse ear vesicant model (MEVM) showed progressive histopathologic changes including edema, separation of the epidermis from the dermis, persistent inflammation, upregulation of laminin γ2 (one of the chains of laminin-332, a heterotrimeric skin glycoprotein required for wound repair), and delayed wound healing from 24 h to 168 h post exposure. This was associated with time related increased expression of the cell survival ER stress marker, GRP78/BiP, and the ER stress apoptosis marker, GADD153/CHOP, suggesting simultaneous activation of both cell survival and non-mitochondrial apoptosis pathways. Dual immunofluorescence labeling of a keratinocyte migration promoting protein, laminin γ2 and GRP78/BIP, showed colocalization of the two molecules 72 h post exposure indicating that the laminin γ2 was misfolded after SM exposure and trapped within the ER. Taken together, these data show that ER stress is induced in mouse skin within 24 h of vesicant exposure in a defensive response to promote cell survival; however, it appears that this response is rapidly overwhelmed by the apoptotic pathway as a consequence of severe SM-induced injury. - Highlights: ► We demonstrated ER stress response in the mouse ear vesicant model. ► We described the asymmetrical nature of wound repair in the MEVM. ► We identified the distribution of various ER stress markers in the MEVM.

  5. Fatigue surviving, fracture resistance, shear stress and finite element analysis of glass fiber posts with different diameters.

    Science.gov (United States)

    Wandscher, Vinícius Felipe; Bergoli, César Dalmolin; de Oliveira, Ariele Freitas; Kaizer, Osvaldo Bazzan; Souto Borges, Alexandre Luiz; Limberguer, Inácio da Fontoura; Valandro, Luiz Felipe

    2015-03-01

    This study evaluated the shear stress presented in glass fiber posts with parallel fiber (0°) and different coronal diameters under fatigue, fracture resistance and FEA. 160 glass-fiber posts (N=160) with eight different coronal diameters were used (DT=double tapered, number of the post=coronal diameter and W=Wider - fiber post with coronal diameter wider than the conventional): DT1.4; DT1.8W; DT1.6; DT2W; DT1.8; DT2.2W; DT2; DT2.2. Eighty posts were submitted to mechanical cycling (3×10(6) cycles; inclination: 45°; load: 50N; frequency: 4Hz; temperature: 37°C) to assess the surviving under intermittent loading and other eighty posts were submitted to fracture resistance testing (resistance [N] and shear-stress [MPa] values were obtained). The eight posts types were 3D modeled (Rhinoceros 4.0) and the shear-stress (MPa) evaluated using FEA (Ansys 13.0). One-way ANOVA showed statistically differences to fracture resistance (DT2.2W and DT2.2 showed higher values) and shear stress values (DT1.4 showed lower values). Only the DT1.4 fiber posts failed after mechanical cycling. FEA showed similar values of shear stress between the groups and these values were similar to those obtained by shear stress testing. The failure analysis showed that 95% of specimens failed by shear. Posts with parallel fiber (0°) may suffer fractures when an oblique shear load is applied on the structure; except the thinner group, greater coronal diameters promoted the same shear stresses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Responses to environmental stresses in woody plants: key to survive and longevity.

    Science.gov (United States)

    Osakabe, Yuriko; Kawaoka, Akiyoshi; Nishikubo, Nobuyuki; Osakabe, Keishi

    2012-01-01

    Environmental stresses have adverse effects on plant growth and productivity, and are predicted to become more severe and widespread in decades to come. Especially, prolonged and repeated severe stresses affecting growth and development would bring down long-lasting effects in woody plants as a result of its long-term growth period. To counteract these effects, trees have evolved specific mechanisms for acclimation and tolerance to environmental stresses. Plant growth and development are regulated by the integration of many environmental and endogenous signals including plant hormones. Acclimation of land plants to environmental stresses is controlled by molecular cascades, also involving cross-talk with other stresses and plant hormone signaling mechanisms. This review focuses on recent studies on molecular mechanisms of abiotic stress responses in woody plants, functions of plant hormones in wood formation, and the interconnection of cell wall biosynthesis and the mechanisms shown above. Understanding of these mechanisms in depth should shed light on the factors for improvement of woody plants to overcome severe environmental stress conditions.

  7. Chronic stress in adulthood followed by intermittent stress impairs spatial memory and the survival of newborn hippocampal cells in aging animals: prevention by FGL, a peptide mimetic of neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Borcel, Erika; Pérez-Alvarez, Laura; Herrero, Ana Isabel

    2008-01-01

    each week to a stress stimulus. When evaluated in the water maze at the early stages of aging (18 months old), chronic unpredictable stress accelerated spatial-cognitive decline, an effect that was accompanied by a reduction in the survival of newborn cells and in the number of adult granular cells......In this study, we examined whether chronic stress in adulthood can exert long-term effects on spatial-cognitive abilities and on the survival of newborn hippocampal cells in aging animals. Male Wistar rats were subjected to chronic unpredictable stress at midlife (12 months old) and then reexposed......, a peptide mimetic of neural cell adhesion molecule, during the 4 weeks of continuous stress not only prevented the deleterious effects of chronic stress on spatial memory, but also reduced the survival of the newly generated hippocampal cells in aging animals. FGL treatment did not, however, prevent...

  8. First feeding of Eugerres brasilianus (Carapeva larvae with Acartia tonsa (Copepod nauplii increases survival and resistance to acute stress

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo Costa

    2016-01-01

    Full Text Available The rotifer Brachionus sp. is commonly used for larval feeding in marine fish hatcheries. The aim of this study was to evaluate whether the inclusion of Acartia tonsa nauplii in the initial diet of carapeva larvae improves their survival, growth and resistance to stress when compared to the regimen containing only rotifers. Adult copepods were collected in the wild and cultured with the microalgae Chaetoceros muelleri, Isochrysis galbana and Nannochloropsis oculata to obtain nauplii. Carapeva larvae were grown for 15 days using four treatments and three replicates: 1 Brachionus plicatilis rotifers (10 to 15/mL; 2 A. tonsa nauplii (0.25 to 0.5/mL; 3 Brachionus plicatilis rotifers (5 to 7.5/mL + A. tonsa nauplii (0.12 to 0.25/mL, and 4 no supply of live feed. After 15 days, the carapeva larvae were subjected to stress by exposure to air for 10 seconds and then returned to the source tank to evaluate survival after 24 h. Survival and stress resistance were higher in carapeva larvae fed B. plicatilis + A. tonsa nauplii (P<0.05, 20.9 ± 11.2% and 88.9%, respectively. These results confirm the positive effect of the inclusion of copepod nauplii in the diet of fish larvae. However, more research is needed to validate these results.

  9. Effect of environmental stress factors on the uptake and survival of Campylobacter jejuni in Acanthamoeba castellanii

    DEFF Research Database (Denmark)

    Bui, Thanh Xuan; Qvortrup, Klaus; Wolff, Anders

    2012-01-01

    Background: Campylobacter jejuni is a major cause of bacterial food-borne illness in Europe and North America. The mechanisms allowing survival in the environment and transmission to new hosts are not well understood. Environmental free-living protozoa may facilitate both processes. Pre-exposure ......Background: Campylobacter jejuni is a major cause of bacterial food-borne illness in Europe and North America. The mechanisms allowing survival in the environment and transmission to new hosts are not well understood. Environmental free-living protozoa may facilitate both processes. Pre...

  10. Artichoke compound cynarin differentially affects the survival, growth and stress response of normal, immortalized and cancerous human cells

    DEFF Research Database (Denmark)

    Gezer, Ceren; Yücecan, Sevinç; Rattan, Suresh Inder Singh

    2015-01-01

    Cynarin (CYN) is the main derivative of caffeoylquinic acid, found in leaves and heads of artichoke. Potential health-beneficial effects of CYN include as being choloretic-cholesterol lowering, hepatoprotective, anti-atherosclerotic, and antioxidative. We have tested the effects of various doses...... of CYN on the proliferative potential, survival, morphology, and stress response (SR) markers haemoxygenase-1 (HO-1) and heat shock protein-70 (HSP70) in normal human skin fibroblasts (FSF-1), telomerase-immortalized mesenchymal stem cells (hTERT-MSC) and cervical cancer cells, HeLa. Effects of CYN...

  11. Weathering the storm: parental effort and experimental manipulation of stress hormones predict brood survival

    NARCIS (Netherlands)

    Ouyang, JQ; Lendvai, AZ; Dakin, R.; Domalik, AD; Fasanello, VJ; Vassallo, BG; Haussmann, MF; Moore, IT; Bonier, F.

    2015-01-01

    BACKGROUND:Unpredictable and inclement weather is increasing in strength and frequency, challenging organisms to respond adaptively. One way in which animals respond to environmental challenges is through the secretion of glucocorticoid stress hormones. These hormones mobilize energy stores and

  12. Source mechanisms and faulting analysis of the aftershocks in the Lake Erçek area (Eastern Anatolia, Turkey) during the 2011 Van event (Mw 7.1): Implications for the regional stress field and ongoing deformation processes

    Science.gov (United States)

    Toker, M.; Pınar, A.; Tur, H.

    2017-12-01

    In this study, we analysed the source mechanisms and faulting pattern of the aftershocks in the Lake Erçek area, Eastern Anatolia, during the 2011 Van event (Mw 7.1). The fault plane solutions of the aftershocks were used to derive a stress tensor acting around Lake Erçek. The estimated seismological parameters (focal mechanism solutions, stress tensor, and fault focal analyses) were integrated with field surveys and high resolution seismic reflection data so as to better understand the main faulting patterns and deformational features which are the causatives of the observed geomorphological features within and around Lake Erçek. The focal parameters of the 56 aftershocks with magnitude range 3.5 ≤ Mw ≤ 5.5 were obtained using the regional broadband seismic data from the network of Kandilli Observatory and Earthquake Research Institute (KOERI) through the Centroid Moment Tensor (CMT) inversion of locally observed broadband-waves. The implications for the lateral variation of the stress field in the lake area were based on information derived from integration of seismicity and stress tensor inversion results. The major outcomes of our analyses were as follows: (a) The maximum principal stress axis is close to horizontal and aligned in NNW-SSE direction, the minimum compressional stress axis is close to vertical and aligned in an ENE-WSW direction, the intermediate stress axis is close to horizontal and is parallel to the strike of the ruptured fault plane, while the stress ratio is (R = 0.6); (b) the lake basin is mostly deformed by dip-slip faults (dips ≥ 45-60°) in and along its margins where the various folds, basement highs with eroded surfaces and several low-angle normal faults are evident; (c) the majority of the aftershocks have reverse-thrust mechanism with some strike-slip components in the Lake Erçek area (N- and S-margins). Strike-slip and normal faulting events are also evident (E- and W-margins, respectively); (d) the normal and reverse

  13. Symptoms of Post-Traumatic Stress Disorder among Surviving Parents of Child Homicide Victims.

    Science.gov (United States)

    Rinear, Eileen E.

    This paper recognizes murder as a major cause of mortality among adolescents and young adults and addresses the need for research examining the effects of murder on the victim's surviving family members. The information contained in this report was obtained from surveys completed by 237 members of the Parents of Murdered Children support group.…

  14. Stress Effects in Channel Catfish (Ictalurus punctatus) Fry on Pond Survival

    Science.gov (United States)

    Results from previous studies suggested that channel catfish (Ictalurus punctatus) fry that were housed in very high traffic areas from hatch until reaching 9 g in size were able to survive experimental challenge with Edwardsiella ictaluri better than siblings who were hatched and raised in very low...

  15. Transcript and protein analysis reveals better survival skills of monocyte-derived dendritic cells compared to monocytes during oxidative stress.

    Directory of Open Access Journals (Sweden)

    Ilse Van Brussel

    Full Text Available BACKGROUND: Dendritic cells (DCs, professional antigen-presenting cells with the unique ability to initiate primary T-cell responses, are present in atherosclerotic lesions where they are exposed to oxidative stress that generates cytotoxic reactive oxygen species (ROS. A large body of evidence indicates that cell death is a major modulating factor of atherogenesis. We examined antioxidant defence systems of human monocyte-derived (moDCs and monocytes in response to oxidative stress. METHODS: Oxidative stress was induced by addition of tertiary-butylhydroperoxide (tert-BHP, 30 min. Cellular responses were evaluated using flow cytometry and confocal live cell imaging (both using 5-(and-6-chloromethyl-2,7-dichlorodihydrofluorescein diacetate, CM-H(2DCFDA. Viability was assessed by the neutral red assay. Total RNA was extracted for a PCR profiler array. Five genes were selected for confirmation by Taqman gene expression assays, and by immunoblotting or immunohistochemistry for protein levels. RESULTS: Tert-BHP increased CM-H(2DCFDA fluorescence and caused cell death. Interestingly, all processes occurred more slowly in moDCs than in monocytes. The mRNA profiler array showed more than 2-fold differential expression of 32 oxidative stress-related genes in unstimulated moDCs, including peroxiredoxin-2 (PRDX2, an enzyme reducing hydrogen peroxide and lipid peroxides. PRDX2 upregulation was confirmed by Taqman assays, immunoblotting and immunohistochemistry. Silencing PRDX2 in moDCs by means of siRNA significantly increased CM-DCF fluorescence and cell death upon tert-BHP-stimulation. CONCLUSIONS: Our results indicate that moDCs exhibit higher intracellular antioxidant capacities, making them better equipped to resist oxidative stress than monocytes. Upregulation of PRDX2 is involved in the neutralization of ROS in moDCs. Taken together, this points to better survival skills of DCs in oxidative stress environments, such as atherosclerotic plaques.

  16. Hvem er vi? Hvem er de?

    DEFF Research Database (Denmark)

    Kryger, Niels

    2016-01-01

    Kommentaren tager afsæt i initiativer i de pædagogiske faglige foreninger i Europa EERA) og i Norden (NERA) og argumenterer for at det er forpligtelse for os som nordiske og europæiske pædagogiske forskere at gå op imod de stadigt mere ekskluderende vi-konstruktioner, som er blevet formuleret i for...

  17. Virtual Institute of Microbial Stress and Survival: Deduction of Stress Response Pathways in Metal and Radionuclide Reducing Microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-04-17

    The projects application goals are to: (1) To understand bacterial stress-response to the unique stressors in metal/radionuclide contamination sites; (2) To turn this understanding into a quantitative, data-driven model for exploring policies for natural and biostimulatory bioremediation; (3) To implement proposed policies in the field and compare results to model predictions; and (4) Close the experimental/computation cycle by using discrepancies between models and predictions to drive new measurements and construction of new models. The projects science goals are to: (1) Compare physiological and molecular response of three target microorganisms to environmental perturbation; (2) Deduce the underlying regulatory pathways that control these responses through analysis of phenotype, functional genomic, and molecular interaction data; (3) Use differences in the cellular responses among the target organisms to understand niche specific adaptations of the stress and metal reduction pathways; (4) From this analysis derive an understanding of the mechanisms of pathway evolution in the environment; and (5) Ultimately, derive dynamical models for the control of these pathways to predict how natural stimulation can optimize growth and metal reduction efficiency at field sites.

  18. Food matrices and cell conditions influence survival of Lactobacillus rhamnosus GG under heat stresses and during storage.

    Science.gov (United States)

    Endo, Akihito; Teräsjärvi, Johanna; Salminen, Seppo

    2014-03-17

    The present study evaluated impact of moisture content and cell conditions on survival of probiotic strain, Lactobacillus rhamnosus GG, under lethal heat stresses and during long-term storage using freeze-dried cells and oils as matrices. Viable cell counts of freeze-dried L. rhamnosus GG cells suspended in oils had only 1-log-reduction after 5min at 80°C and approximately 3-log-reduction after 20min, while no or very few viable cells were recorded for freeze dried cells suspended in buffer and cultured cells in oils. Surprisingly, freeze-dried cells suspended in oils still contained 4.3 to 6.7logCFU/ml after 5min at 95°C. Long-term storage study indicated that freeze-dried cells suspended in oils kept viable conditions for 4months, and a loss of the viability was only 0.3 to 0.6logCFU/ml. Viable cell counts of cultured cells suspended in oils were not present after 3days to 3months. These results clearly indicate that moisture and cell conditions have a great impact on survival of probiotics under severe heat stress in processing and during long-term storage. Combination of freeze-dried cells and oils as carrier provides beneficial options to preserve viability of probiotics in food processes and storage. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. C. elegans AMPKs promote survival and arrest germline development during nutrient stress

    Directory of Open Access Journals (Sweden)

    Masamitsu Fukuyama

    2012-08-01

    Mechanisms controlling development, growth, and metabolism are coordinated in response to changes in environmental conditions, enhancing the likelihood of survival to reproductive maturity. Much remains to be learned about the molecular basis underlying environmental influences on these processes. C. elegans larvae enter a developmentally dormant state called L1 diapause when hatched into nutrient-poor conditions. The nematode pten homologue daf-18 is essential for maintenance of survival and germline stem cell quiescence during this period (Fukuyama et al., 2006; Sigmond et al., 2008, but the details of the signaling network(s in which it functions remain to be elucidated. Here, we report that animals lacking both aak-1 and aak-2, which encode the two catalytic α subunits of AMP-activated protein kinase (AMPK, show reduced viability and failure to maintain mitotic quiescence in germline stem cells during L1 diapause. Furthermore, failure to arrest germline proliferation has a long term consequence; aak double mutants that have experienced L1 diapause develop into sterile adults when returned to food, whereas their continuously fed siblings are fertile. Both aak and daf-18 appear to maintain germline quiescence by inhibiting activity of the common downstream target, TORC1 (TOR Complex 1. In contrast, rescue of the lethality phenotype indicates that aak-2 acts not only in the intestine, as does daf-18, but also in neurons, likely promoting survival by preventing energy deprivation during L1 diapause. These results not only provide evidence that AMPK contributes to survival during L1 diapause in a manner distinct from that by which it controls dauer diapause, but they also suggest that AMPK suppresses TORC1 activity to maintain stem cell quiescence.

  20. Puf er plat

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg; Zeller, Clara

    2015-01-01

    Der er stort set ingen, der har fattet, hvad nudging egentlig er. Et nudge er nemlig hverken ”et lille blidt skub”, eller ”en helt ny videnskabelig metode [der] kan ændre vores adfærd, uden vi opdager det - og uden det koster os noget”, ligesom det heller ikke er ”en måde at friste kunder til at ...

  1. Mosquito control pesticides and sea surface temperatures have differential effects on the survival and oxidative stress response of coral larvae.

    Science.gov (United States)

    Ross, Cliff; Olsen, Kevin; Henry, Michael; Pierce, Richard

    2015-04-01

    The declining health of coral reefs is intensifying worldwide at an alarming rate due to the combined effects of land-based sources of pollution and climate change. Despite the persistent use of mosquito control pesticides in populated coastal areas, studies examining the survival and physiological impacts of early life-history stages of non-targeted marine organisms are limited. In order to better understand the combined effects of mosquito pesticides and rising sea surface temperatures, we exposed larvae from the coral Porites astreoides to selected concentrations of two major mosquito pesticide ingredients, naled and permethrin, and seawater elevated +3.5 °C. Following 18-20 h of exposure, larvae exposed to naled concentrations of 2.96 µg L(-1) or greater had significantly reduced survivorship compared to controls. These effects were not detected in the presence of permethrin or elevated temperature. Furthermore, larval settlement, post-settlement survival and zooxanthellae density were not impacted by any treatment. To evaluate the sub-lethal stress response of larvae, several oxidative stress endpoints were utilized. Biomarker responses to pesticide exposure were variable and contingent upon pesticide type as well as the specific biomarker being employed. In some cases, such as with protein carbonylation and catalase gene expression, the effects of naled exposure and temperature were interactive. In other cases pesticide exposure failed to induce any sub-lethal stress response. Overall, these results demonstrate that P. astreoides larvae have a moderate degree of resistance against short-term exposure to ecologically relevant concentrations of pesticides even in the presence of elevated temperature. In addition, this work highlights the importance of considering the complexity and differential responses encountered when examining the impacts of combined stressors that occur on varying spatial scales.

  2. Demokratiets krise er lovende

    DEFF Research Database (Denmark)

    Thomassen, Bjørn; Harrebye, Silas Fehmerling

    2016-01-01

    Demokratiet er i krise. Men den er langtfra bundløs. For når eksisterende partier, traditionelle virksomheder, den velkendte fagforening og de gamle medier udfordres, opstår muligheden for et sceneskift. Meget peger på, at det er på vej...

  3. Endoplasmic Reticulum Stress, Unfolded Protein Response, and Cancer Cell Fate

    Science.gov (United States)

    Corazzari, Marco; Gagliardi, Mara; Fimia, Gian Maria; Piacentini, Mauro

    2017-01-01

    Perturbation of endoplasmic reticulum (ER) homeostasis results in a stress condition termed “ER stress” determining the activation of a finely regulated program defined as unfolded protein response (UPR) and whose primary aim is to restore this organelle’s physiological activity. Several physiological and pathological stimuli deregulate normal ER activity causing UPR activation, such as hypoxia, glucose shortage, genome instability, and cytotoxic compounds administration. Some of these stimuli are frequently observed during uncontrolled proliferation of transformed cells, resulting in tumor core formation and stage progression. Therefore, it is not surprising that ER stress is usually induced during solid tumor development and stage progression, becoming an hallmark of such malignancies. Several UPR components are in fact deregulated in different tumor types, and accumulating data indicate their active involvement in tumor development/progression. However, although the UPR program is primarily a pro-survival process, sustained and/or prolonged stress may result in cell death induction. Therefore, understanding the mechanism(s) regulating the cell survival/death decision under ER stress condition may be crucial in order to specifically target tumor cells and possibly circumvent or overcome tumor resistance to therapies. In this review, we discuss the role played by the UPR program in tumor initiation, progression and resistance to therapy, highlighting the recent advances that have improved our understanding of the molecular mechanisms that regulate the survival/death switch. PMID:28491820

  4. Endoplasmic Reticulum Stress, Unfolded Protein Response, and Cancer Cell Fate

    Directory of Open Access Journals (Sweden)

    Marco Corazzari

    2017-04-01

    Full Text Available Perturbation of endoplasmic reticulum (ER homeostasis results in a stress condition termed “ER stress” determining the activation of a finely regulated program defined as unfolded protein response (UPR and whose primary aim is to restore this organelle’s physiological activity. Several physiological and pathological stimuli deregulate normal ER activity causing UPR activation, such as hypoxia, glucose shortage, genome instability, and cytotoxic compounds administration. Some of these stimuli are frequently observed during uncontrolled proliferation of transformed cells, resulting in tumor core formation and stage progression. Therefore, it is not surprising that ER stress is usually induced during solid tumor development and stage progression, becoming an hallmark of such malignancies. Several UPR components are in fact deregulated in different tumor types, and accumulating data indicate their active involvement in tumor development/progression. However, although the UPR program is primarily a pro-survival process, sustained and/or prolonged stress may result in cell death induction. Therefore, understanding the mechanism(s regulating the cell survival/death decision under ER stress condition may be crucial in order to specifically target tumor cells and possibly circumvent or overcome tumor resistance to therapies. In this review, we discuss the role played by the UPR program in tumor initiation, progression and resistance to therapy, highlighting the recent advances that have improved our understanding of the molecular mechanisms that regulate the survival/death switch.

  5. Plant survival in a changing environment: the role of nitric oxide in plant responses to abiotic stress

    Directory of Open Access Journals (Sweden)

    Marcela eSimontacchi

    2015-11-01

    Full Text Available Nitric oxide in plants may originate endogenously or come from surrounding atmosphere and soil. Interestingly, this gaseous free radical is far from having a constant level and varies greatly among tissues depending on a given plant´s ontogeny and environmental fluctuations.Proper plant growth, vegetative development, and reproduction require the integration of plant hormonal activity with the antioxidant network, as well as the maintenance of concentration of reactive oxygen and nitrogen species within a narrow range. Plants are frequently faced with abiotic stress conditions such as low nutrient availability, salinity, drought, high ultraviolet (UV radiation and extreme temperatures, which can influence developmental processes and lead to growth restriction making adaptive responses the plant´s priority. The ability of plants to respond and survive under environmental-stress conditions involves sensing and signalling events where nitric oxide becomes a critical component mediating hormonal actions, interacting with reactive oxygen species, and modulating gene expression and protein activity. This review focuses on the current knowledge of the role of nitric oxide in adaptive plant responses to some specific abiotic stress conditions, particularly low mineral nutrient supply, drought, salinity and high UV-B radiation.

  6. Short-Term Diet and Moderate Exercise in Young Overweight Men Modulate Cardiocyte and Hepatocarcinoma Survival by Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Marcellino Monda

    2014-01-01

    Full Text Available The present study was designed to evaluate the effects of diet lifestyle on extending lifespan and reducing liver cancer risk. Young overweight men (n=20, without metabolic syndrome, were placed in a 3-week residential program on a low-fat diet and moderate aerobic exercise. In each subject, pre- and postintervention fasting blood were collected for evaluating levels of serum lipids, and oxidative stress markers. Using subject sera and cardiomyocyte (H9C2 culture systems, we measured heat shock protein 27 and 90 expression, lipid accumulation, and oxidative stress marker levels. After 3-weeks of diet, significant reductions (P<0.05 in body mass index, serum lipids and lipid ratios, and oxidative markers were recorded. In vitro, we observed that the addition of postintervention sera increased H9C2 cell number and reduced HSP27 and 90 expression, mitochondrial superoxide anion, and lipid accumulation with a parallel increase in nitric oxide (NO production (all P<0.01. At the same time, postintervention sera decreased human liver hepatocellular carcinoma cell line (HepG-2 proliferation, lipid accumulation, oxidative stress, and extracellular-signal-regulated kinases (ERK1/2 activity. Lifestyle modification in young overweight men, without metabolic syndrome, could ameliorate cardiocyte survival and reduce hepatocellular carcinoma cell proliferation.

  7. Calcium/calmodulin-dependent kinases are involved in growth, thermotolerance, oxidative stress survival, and fertility in Neurospora crassa.

    Science.gov (United States)

    Kumar, Ravi; Tamuli, Ranjan

    2014-04-01

    Calcium/calmodulin-dependent kinases (Ca(2+)/CaMKs) are Ser/Thr protein kinases that respond to change in cytosolic free Ca(2+) ([Ca(2+)]c) and play multiple cellular roles in organisms ranging from fungi to humans. In the filamentous fungus Neurospora crassa, four Ca(2+)/CaM-dependent kinases, Ca(2+)/CaMK-1 to 4, are encoded by the genes NCU09123, NCU02283, NCU06177, and NCU09212, respectively. We found that camk-1 and camk-2 are essential for full fertility in N. crassa. The survival of ∆camk-2 mutant was increased in induced thermotolerance and oxidative stress conditions. In addition, the ∆camk-1 ∆camk-2, ∆camk-4 ∆camk-2, and ∆camk-3 ∆camk-2 double mutants display slow growth phenotype, reduced aerial hyphae, decreased thermotolerance, and increased sensitivity to oxidative stress, revealing the genetic interactions among these kinases. Therefore, Ca(2+)/CaMKs are involved in growth, thermotolerance, oxidative stress tolerance, and fertility in N. crassa.

  8. Chronic stress increases experimental pancreatic cancer growth, reduces survival and can be antagonised by beta-adrenergic receptor blockade.

    Science.gov (United States)

    Partecke, Lars Ivo; Speerforck, Sven; Käding, André; Seubert, Florian; Kühn, Sandra; Lorenz, Eric; Schwandke, Sebastian; Sendler, Matthias; Keßler, Wolfram; Trung, Dung Nguyen; Oswald, Stefan; Weiss, Frank Ulrich; Mayerle, Julia; Henkel, Christin; Menges, Pia; Beyer, Katharina; Lerch, Markus M; Heidecke, Claus-Dieter; von Bernstorff, Wolfram

    2016-01-01

    Chronic stress could promote tumour growth and reduce survival of pancreatic cancer patients via beta-adrenergic receptors of tumour cells. We have tested the impact of chronic acoustic and restraint stress on tumour development in an orthotopic syngeneic murine model of pancreatic cancer. Tumour-bearing C57BL/6 mice exposed to chronic stress had 45% (p = 0.0138) higher circulating steroid and 111% (p = 0.0052) higher adrenal tyrosine hydroxylase levels. Their immune response was significantly suppressed: The in vitro LPS response of splenocytes was significantly reduced regarding Th1- and Th2-cytokines including IFN-gamma, IL-6, IL-10 and MCP-1 (0.0011  0.05). TGF-beta in vitro was increased by 23.4% using catecholamines (p Beta-catecholamines increased proliferation in tumour cells by 18% (p beta-blocker propranolol reduced these effects by 25% (p beta-blockers of patients with pancreatic cancer or other malignancies should be further evaluated as an adjuvant anti-neoplastic agent in clinical trials. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  9. Protective effect of catechin in type I Gaucher disease cells by reducing endoplasmic reticulum stress

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yea-Jin [Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, 336-795 (Korea, Republic of); Kim, Sung-Jo, E-mail: sungjo@hoseo.edu [Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, 336-795 (Korea, Republic of); Heo, Tae-Hwe, E-mail: thhur92@catholic.ac.kr [College of Pharmacy, The Catholic University of Korea, Bucheon 420-743 (Korea, Republic of)

    2011-09-23

    Highlights: {yields} Catechin reduces the expression level of ER stress marker protein in type I Gaucher disease cells. {yields} Catechin induces the proliferation rate of GD cells similar levels to normal cells. {yields} Catechin improves wound healing activity. {yields} Catechin-mediated reductions in ER stress may be associated with enhanced cell survival. {yields} We identified catechin as a protective agent against ER stress in GD cells. -- Abstract: Gaucher disease (GD) is the most common lysosomal storage disorder (LSD) and is divided into three phenotypes, I, II, and III. Type I is the most prevalent form and has its onset in adulthood. The degree of endoplasmic reticulum (ER) stress is one of the factors that determine GD severity. It has recently been reported that antioxidants reduce ER stress and apoptosis by scavenging the oxidants that cause oxidative stress. For this report, we investigated the possibility that catechin can act on type I GD patient cells to alleviate the pathogenic conditions of GD. We treated GD cells with catechin and examined the expression level of GRP78/BiP (an ER stress marker) by western blots and fluorescence microscopy, the proliferation rate of GD cells, and scratch-induced wound healing activity. Our results show that catechin reduces the expression level of GRP78/BiP, leads to cell proliferation rates of GD cells similar levels to normal cells, and improves wound healing activity. We conclude that catechin protects against ER stress in GD cells and catechin-mediated reductions in ER stress may be associated with enhanced cell survival.

  10. Under Stress: Social Coping Mechanisms for Survival among the Working Professionals

    OpenAIRE

    Ms. Coral Barboza; Dr. Babu Thomas

    2016-01-01

    The nature of work of professionals and their family life may very often expose them to high level of stress which has the potential of affecting their productive and earning capacity. Coping strategies have been the subject of many studies and various suggestions have been made regarding the most appropriate way to categorise them in terms of function and efficacy (Amble, 2006; Buys et al., 2010). The goal of the current study was to examine how social coping mechanisms are helpful to employ...

  11. Effect of Hypergravity Stress on Gaseous Exchange and Survival of Young and Old Guinea Pigs

    Science.gov (United States)

    Muradian, Kh. K.; Timchenko, A. N.

    Hypergravity tolerance decreases in aging Guinea pigs, the range being lower than in other studied species of laboratory mammals - mice, hamsters, and rats. Moreover, for the gaseous exchange rate and body temperature, the decline during the stress is not characteristic for Guinea pigs of both age groups, in contrast to other species. In general, hypergravity tolerance of Guinea pigs could be more appropriate experimental models.

  12. Loss of PINK1 impairs stress-induced autophagy and cell survival.

    Directory of Open Access Journals (Sweden)

    Dajana Parganlija

    Full Text Available The mitochondrial kinase PINK1 and the ubiquitin ligase Parkin are participating in quality control after CCCP- or ROS-induced mitochondrial damage, and their dysfunction is associated with the development and progression of Parkinson's disease. Furthermore, PINK1 expression is also induced by starvation indicating an additional role for PINK1 in stress response. Therefore, the effects of PINK1 deficiency on the autophago-lysosomal pathway during stress were investigated. Under trophic deprivation SH-SY5Y cells with stable PINK1 knockdown showed downregulation of key autophagic genes, including Beclin, LC3 and LAMP-2. In good agreement, protein levels of LC3-II and LAMP-2 but not of LAMP-1 were reduced in different cell model systems with PINK1 knockdown or knockout after addition of different stressors. This downregulation of autophagic factors caused increased apoptosis, which could be rescued by overexpression of LC3 or PINK1. Taken together, the PINK1-mediated reduction of autophagic key factors during stress resulted in increased cell death, thus defining an additional pathway that could contribute to the progression of Parkinson's disease in patients with PINK1 mutations.

  13. Survival and virulence of copper- and chlorine-stressed Yersinia enterocolitica in Experimentally infected mice

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.; McFeters, G.A.

    1987-08-01

    The effect of gastric pH on the viability and virulence of Yersinia enterocolitica 0:8 after exposure to sublethal concentrations of copper and chlorine was determined in mice. Viability and injury were assessed with a nonselective TLY agar and two selective media, TLYD agar and CIN agar. Both copper and chlorine caused injury which was manifested by the inability of the cells to grow on selective media. CIN agar was more restrictive to the growth of injured cells than TLYD agar. Injury of the exposed cells was further enhanced in the gastric environment of mice. Besides injury, the low gastric pH caused extensive loss of viability in copper-exposed cells. Lethality in the chlorine-exposed cells was less extensive, and a portion of the inoculum reached the small intestine 5 min postinoculation. No adverse effect on the injured cells was apparent in the small intestine, and a substantial revival of the injury occurred in 3 to 4 h after intraluminal inoculation. The virulence of chlorine-stressed Y. enterocolitica in orally inoculated mice was similar to that of the control culture, but copper-stressed cells showed reduced virulence. Virulence was partly restored by oral administration of sodium bicarbonate before the inoculation of copper-exposed cells. Neutralization of gastric acidity had no effect on the virulence of the control of chlorine-stressed cells.

  14. High temperature and drought stress effects on survival of Pinus ponderosa seedlings.

    Science.gov (United States)

    Kolb, P F; Robberecht, R

    1996-08-01

    We studied the effects of high temperature and drought on the survival, growth and water relations of seedlings of Pinus ponderosa (Dougl.) Lawson, one of few coniferous tree species that can successfully colonize drought-prone sites with high soil surface temperatures. Temperature profiles were measured with 0.07-mm thermocouples in a sparse ponderosa pine forest in northern Idaho. The soil surface and the adjacent 5 mm of air reached maximum temperatures exceeding 75 degrees C, well above the lethal temperature threshold for most plants. Air temperatures 50 mm above the soil surface (seedling needle height) rarely exceeded 45 degrees C. Pinus ponderosa seedlings that survived maintained basal stem temperatures as much as 15 degrees C lower than the surrounding air. The apparent threshold temperature at the seedling stem surface resulting in death was approximately 63 degrees C for less than 1 min. No correlation between seedling mortality and needle temperature was found, although some needles reached temperatures as high as 60 degrees C for periods of cooling the stem below the lethal threshold temperature. Heat exchange calculations showed that rapid water flow through seedling stems can absorb sufficient energy to reduce stem temperature by 30 degrees C during peak sunlight hours.

  15. Diabetic retinopathy pathogenesis and the ameliorating effects of melatonin; involvement of autophagy, inflammation and oxidative stress.

    Science.gov (United States)

    Dehdashtian, Ehsan; Mehrzadi, Saeed; Yousefi, Bahman; Hosseinzadeh, Azam; Reiter, Russel J; Safa, Majid; Ghaznavi, Habib; Naseripour, Masood

    2018-01-15

    Diabetic retinopathy (DR), a microvascular complication of diabetes mellitus (DM), remains as one of the major causes of vision loss worldwide. The release of pro-inflammatory cytokines and the adhesion of leukocytes to retinal capillaries are initial events in DR development. Inflammation, ER stress, oxidative stress and autophagy are major causative factors involved in the pathogenesis of DR. Diabetes associated hyperglycemia leads to mitochondrial electron transport chain dysfunction culminating in a rise in ROS generation. Since mitochondria are the major source of ROS production, oxidative stress induced by mitochondrial dysfunction also contributes to the development of diabetic retinopathy. Autophagy increases in the retina of diabetic patients and is regulated by ER stress, oxidative stress and inflammation-related pathways. Autophagy functions as a double-edged sword in DR. Under mild stress, autophagic activity can lead to cell survival while during severe stress, dysregulated autophagy results in massive cell death and may have a role in initiation and exacerbation of DR. Melatonin and its metabolites play protective roles against inflammation, ER stress and oxidative stress due to their direct free radical scavenger activities and indirect antioxidant activity via the stimulation antioxidant enzymes including glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase. Melatonin also acts as a cell survival agent by modulating autophagy in various cell types and under different conditions through amelioration of oxidative stress, ER stress and inflammation. Herein, we review the possible effects of melatonin on diabetic retinopathy, focusing on its ability to regulate autophagy processes. Copyright © 2017. Published by Elsevier Inc.

  16. Do mycorrhizal network benefits to survival and growth of interior Douglas-fir seedlings increase with soil moisture stress?

    Science.gov (United States)

    Bingham, Marcus A; Simard, Suzanne W

    2011-11-01

    Facilitation of tree establishment by ectomycorrhizal (EM) networks (MNs) may become increasingly important as drought stress increases with climate change in some forested regions of North America. The objective of this study was to determine (1) whether temperature, CO(2) concentration ([CO(2)]), soil moisture, and MNs interact to affect plant establishment success, such that MNs facilitate establishment when plants are the most water stressed, and (2) whether transfer of C and water between plants through MNs plays a role in this. We established interior Douglas-fir (Pseudotsuga menziesiivar.glauca) seedlings in root boxes with and without the potential to form MNs with nearby conspecific seedlings that had consistent access to water via their taproots. We varied temperature, [CO(2)], and soil moisture in growth chambers. Douglas-fir seedling survival increased when the potential existed to form an MN. Growth increased with MN potential under the driest soil conditions, but decreased with temperature at 800 ppm [CO(2)]. Transfer of (13)C to receiver seedlings was unaffected by potential to form an MN with donor seedlings, but deuterated water (D(2)O) transfer increased with MN potential under ambient [CO(2)]. Chlorophyll fluorescence was reduced when seedlings had the potential to form an MN under high [CO(2)] and cool temperatures. We conclude that Douglas-fir seedling establishment in laboratory conditions is facilitated by MN potential where Douglas-fir seedlings have consistent access to water. Moreover, this facilitation appears to increase as water stress potential increases and water transfer via networks may play a role in this. These results suggest that conservation of MN potential may be important to forest regeneration where drought stress increases with climate change.

  17. Survival of the Fittest: Overcoming Oxidative Stress at the Extremes of Acid, Heat and Metal

    Directory of Open Access Journals (Sweden)

    Yukari Maezato

    2012-08-01

    Full Text Available The habitat of metal respiring acidothermophilic lithoautotrophs is perhaps the most oxidizing environment yet identified. Geothermal heat, sulfuric acid and transition metals contribute both individually and synergistically under aerobic conditions to create this niche. Sulfuric acid and metals originating from sulfidic ores catalyze oxidative reactions attacking microbial cell surfaces including lipids, proteins and glycosyl groups. Sulfuric acid also promotes hydrocarbon dehydration contributing to the formation of black “burnt” carbon. Oxidative reactions leading to abstraction of electrons is further impacted by heat through an increase in the proportion of reactant molecules with sufficient energy to react. Collectively these factors and particularly those related to metals must be overcome by thermoacidophilic lithoautotrophs in order for them to survive and proliferate. The necessary mechanisms to achieve this goal are largely unknown however mechanistics insights have been gained through genomic studies. This review focuses on the specific role of metals in this extreme environment with an emphasis on resistance mechanisms in Archaea.

  18. Peroxiredoxin 3 maintains the survival of endometrial cancer stem cells by regulating oxidative stress.

    Science.gov (United States)

    Song, In-Sung; Jeong, Yu Jeong; Seo, Young Jin; Byun, Jung Mi; Kim, Young Nanm; Jeong, Dae Hoon; Han, Jin; Kim, Ki Tae; Jang, Sung-Wuk

    2017-11-03

    Cancer stem cell (CSC)-targeted therapy could reduce tumor growth, recurrence, and metastasis in endometrial cancer (EC). The mitochondria of CSCs have been recently found to be an important target for cancer treatment, but the mitochondrial features of CSCs and their regulators, which maintain mitochondrial function, remain unclear. Here, we investigated the mitochondrial properties of CSCs, and identified specific targets for eliminating CSCs in EC. We found that endometrial CSCs displayed higher mitochondrial membrane potential, Ca 2+ , reactive oxygen species, ATP levels, and oxygen consumption rates than non-CSCs. Further, we also verified that mitochondrial peroxiredoxin 3 (Prx3) was upregulated, and that it contributed to the survival of CSCs in EC. The knockdown of the Prx3 gene resulted not only in decreased sphere formation, but also reduced the viability of endometrial CSCs, by causing mitochondrial dysfunction. Furthermore, we found that the forkhead box protein M1 (FoxM1), an important transcriptional factor, is overexpressed in patients with EC. FoxM1 expression correlates with elevated Prx3 expression levels, in agreement with the tumorigenic ability of Prx3 in endometrial CSCs. Taken together, our findings indicate that human endometrial CSCs have enhanced mitochondrial function compared to that of endometrial tumor cells. Endometrial CSCs show increased expression of the mitochondrial Prx3, which is required for the maintenance of mitochondrial function and survival, and is induced by FoxM1. Based on our findings, we believe that these proteins might represent valuable therapeutic targets and could provide new insights into the development of new therapeutic strategies for patients with endometrial cancer.

  19. Sirtuin 7 promotes cellular survival following genomic stress by attenuation of DNA damage, SAPK activation and p53 response

    Energy Technology Data Exchange (ETDEWEB)

    Kiran, Shashi; Oddi, Vineesha [Laboratory of Cancer Biology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, 500001 (India); Ramakrishna, Gayatri, E-mail: gayatrirama1@gmail.com [Laboratory of Cancer Biology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, 500001 (India); Laboratory of Cancer Cell Biology, Department of Research, Institute of Liver and Biliary Sciences, Delhi 110070 (India)

    2015-02-01

    Maintaining the genomic integrity is a constant challenge in proliferating cells. Amongst various proteins involved in this process, Sirtuins play a key role in DNA damage repair mechanisms in yeast as well as mammals. In the present work we report the role of one of the least explored Sirtuin viz., SIRT7, under conditions of genomic stress when treated with doxorubicin. Knockdown of SIRT7 sensitized osteosarcoma (U2OS) cells to DNA damage induced cell death by doxorubicin. SIRT7 overexpression in NIH3T3 delayed cell cycle progression by causing delay in G1 to S transition. SIRT7 overexpressing cells when treated with low dose of doxorubicin (0.25 µM) showed delayed onset of senescence, lesser accumulation of DNA damage marker γH2AX and lowered levels of growth arrest markers viz., p53 and p21 when compared to doxorubicin treated control GFP expressing cells. Resistance to DNA damage following SIRT7 overexpression was also evident by EdU incorporation studies where cellular growth arrest was significantly delayed. When treated with higher dose of doxorubicin (>1 µM), SIRT7 conferred resistance to apoptosis by attenuating stress activated kinases (SAPK viz., p38 and JNK) and p53 response thereby shifting the cellular fate towards senescence. Interestingly, relocalization of SIRT7 from nucleolus to nucleoplasm together with its co-localization with SAPK was an important feature associated with DNA damage. SIRT7 mediated resistance to doxorubicin induced apoptosis and senescence was lost when p53 level was restored by nutlin treatment. Overall, we propose SIRT7 attenuates DNA damage, SAPK activation and p53 response thereby promoting cellular survival under conditions of genomic stress. - Highlights: • Knockdown of SIRT7 sensitized cells to DNA damage induced apoptosis. • SIRT7 delayed onset of premature senescence by attenuating DNA damage response. • Overexpression of SIRT7 delayed cell cycle progression by delaying G1/S transition. • Upon DNA damage SIRT

  20. A detailed view of Listeria monocytogenes’ adaptation and survival under cold temperature stress

    DEFF Research Database (Denmark)

    Hingston, P.; Hansen, Lisbeth Truelstrup; Wang, S.

    The human pathogen Listeria monocytogenes (Lm) continues to be a challenge for the food industry where it is known to contaminate ready-to-eat foods and grow during refrigerated storage. In order to gain increased control of Lm in the food-supply-chain, an improved understanding of low temperature...... stress adaptation methods is needed. In this study, RNA-seq (strand specific Illumina libraries;22-39 million 2x100bp reads) and cell membrane fatty acid profiling were used to analyze adaptation mechanisms used by a fast growing, serotype 1/2a, Lm food plant isolate at 4°C. Brain heart infusion (BHI...

  1. Repeated freezing induces oxidative stress and reduces survival in the freeze-tolerant goldenrod gall fly, Eurosta solidaginis.

    Science.gov (United States)

    Doelling, Adam R W; Griffis, Nicole; Williams, Jason B

    2014-08-01

    Freeze tolerant insects must not only survive extracellular ice formation but also the generation of reactive oxygen species (ROS) during oxygen reperfusion upon thawing. Furthermore, diurnal fluctuations in temperature place temperate insects at risk of being exposed to multiple freeze-thaw cycles, yet few studies have examined metrics of survival and oxidative stress in freeze-tolerant insects subjected to successive freezing events. To address this, we assessed survival in larvae of the goldenrod gall fly Eurosta solidaginis, after being subjected to 0, 5, 10, 20, or 30 diurnally repeated cold exposures (RCE) to -18°C or a single freeze to -18°C for 20days. In addition, we measured indicators of oxidative stress, levels of cryoprotectants, and total aqueous antioxidant capacity in animals exposed to the above treatments at 8, 32, or 80h after their final thaw. Repeated freezing and thawing, rather than time spent frozen, reduced survival as only 30% of larvae subjected to 20 or 30 RCE successfully pupated, compared to those subjected to fewer RCE or a single 20d freeze, of which 82% pupated. RCE had little effect on the concentration of the cryoprotectant glycerol (4.26±0.66μgglycerol·ngprotein(-1) for all treatments and time points) or sorbitol (18.8±2.9μgsorbitol·mgprotein(-1) for all treatments and time points); however, sorbitol concentrations were more than twofold higher than controls (16.3±2.2μgsorbitol·mgprotein(-1)) initially after a thaw in larvae subjected to a single extended freeze, but levels returned to values similar to controls at 80h after thaw. Thawing likely produced ROS as total aqueous antioxidant capacities peaked at 1.8-fold higher than controls (14.7±1.6mmoltrolox·ngprotein(-1)) in animals exposed to 5, 10, or 20 RCE. By contrast, aqueous antioxidant capacities were similar to controls in larvae subjected to 30 RCE or the single 20d freeze regardless of time post final thaw, indicating these animals may have had an impaired

  2. Distinct Functional Domains of UBC9 Dictate Cell Survival and Resistance to Genotoxic Stress

    Energy Technology Data Exchange (ETDEWEB)

    Van Waardenburg,R.; Duda, D.; Lancaster, C.; Schulman, B.; Bjornsti, M.

    2006-01-01

    Covalent modification with SUMO alters protein function, intracellular localization, or protein-protein interactions. Target recognition is determined, in part, by the SUMO E2 enzyme, Ubc9, while Siz/Pias E3 ligases may facilitate select interactions by acting as substrate adaptors. A yeast conditional Ubc9P{sub 123}L mutant was viable at 36 C yet exhibited enhanced sensitivity to DNA damage. To define functional domains in Ubc9 that dictate cellular responses to genotoxic stress versus those necessary for cell viability, a 1.75- Angstroms structure of yeast Ubc9 that demonstrated considerable conservation of backbone architecture with human Ubc9 was solved. Nevertheless, differences in side chain geometry/charge guided the design of human/yeast chimeras, where swapping domains implicated in (i) binding residues within substrates that flank canonical SUMOylation sites, (ii) interactions with the RanBP2 E3 ligase, and (iii) binding of the heterodimeric E1 and SUMO had distinct effects on cell growth and resistance to DNA-damaging agents. Our findings establish a functional interaction between N-terminal and substrate-binding domains of Ubc9 and distinguish the activities of E3 ligases Siz1 and Siz2 in regulating cellular responses to genotoxic stress.

  3. Posttraumatic stress and posttraumatic growth among low-income mothers who survived Hurricane Katrina.

    Science.gov (United States)

    Lowe, Sarah R; Manove, Emily E; Rhodes, Jean E

    2013-10-01

    The purpose of the study was to explore the relationship between posttraumatic stress (PTS) and posttraumatic growth (PTG) after Hurricane Katrina, and the role of demographics, predisaster psychological distress, hurricane-related stressors, and psychological resources (optimism and purpose) in predicting each. Participants were 334 low-income mothers (82.0% non-Hispanic Black) living in the New Orleans area prior to Hurricane Katrina, who completed surveys in the year prior to the hurricane (T1 [Time 1]) and 1 and 3 years thereafter (T2 and T3). Higher T2 and T3 PTS full-scale and symptom cluster subscales (Intrusion, Avoidance, and Hyperarousal) were significantly associated with higher T3 PTG, and participants who surpassed the clinical cutoff for probable posttraumatic stress disorder at both T2 and T3 had significantly higher PTG than those who never surpassed the clinical cutoff. Older and non-Hispanic Black participants, as well as those who experienced a greater number of hurricane-related stressors and bereavement, reported significantly greater T3 PTS and PTG. Participants with lower T2 optimism reported significantly greater T3 intrusive symptoms, whereas those with higher T1 and T2 purpose reported significantly greater T3 PTG. Based on the results, we suggest practices and policies with which to identify disaster survivors at greater risk for PTS, as well as longitudinal investigations of reciprocal and mediational relationships between psychological resources, PTS, and PTG. (c) 2013 APA, all rights reserved.

  4. DIABETES ASSOCIATED OXIDATIVE STRESS AND INFLAMMATION ALTERS THE PROTECTIVE EFFECT OF OBESITY ON SURVIVAL IN CHD PATIENTS

    Directory of Open Access Journals (Sweden)

    Serpil M. Deger

    2012-06-01

    Full Text Available In contrast to the adverse outcomes of obesity in general population, increased body mass index (BMI is associated with improved survival in hemodialysis (CHD patients. The aim of this retrospective study was to evaluate the association between obesity and mortality by diabetic status among 98 maintenance CHD patients. The median follow up was 33 (19, 56 months. Mean age was 49±13 years, 66% were male and 48 % had obesity. 45% of obese subjects were diabetic. Among the subgroups of study population, survival of diabetic obese patients was significantly lower compared to non-diabetic obese subjects (p=0.007 (Figure 1. The subgroup comparisons showed that diabetic obese patients tend to have higher truncal fat percentage (p<0.001 and lower lean body mass standardized by body surface area compared to nondiabetic counterparts although difference was not statistically significance. Diabetic obese patients had higher leptin (p=0.001 and high sensitivity C-reactive protein levels (0.005. Additionally, protein thiols (P-SH were significantly decreased in diabetic obese participants (p=0.03. Although, elevated body fatness appears to be protective for CHD population, presence of overt diabetes alters this advantage by increasing inflammation and oxidative stress.fx1

  5. MicroRNAs meet calcium: joint venture in ER proteostasis.

    Science.gov (United States)

    Finger, Fabian; Hoppe, Thorsten

    2014-11-04

    The endoplasmic reticulum (ER) is a cellular compartment that has a key function in protein translation and folding. Maintaining its integrity is of fundamental importance for organism's physiology and viability. The dynamic regulation of intraluminal ER Ca(2+) concentration directly influences the activity of ER-resident chaperones and stress response pathways that balance protein load and folding capacity. We review the emerging evidence that microRNAs play important roles in adjusting these processes to frequently changing intracellular and environmental conditions to modify ER Ca(2+) handling and storage and maintain ER homeostasis. Copyright © 2014, American Association for the Advancement of Science.

  6. Anatomical regulation of ice nucleation and cavitation helps trees to survive freezing and drought stress

    Science.gov (United States)

    Lintunen, A.; Hölttä, T.; Kulmala, M.

    2013-06-01

    Water in the xylem, the water transport system of plants, is vulnerable to freezing and cavitation, i.e. to phase change from liquid to ice or gaseous phase. The former is a threat in cold and the latter in dry environmental conditions. Here we show that a small xylem conduit diameter, which has previously been shown to be associated with lower cavitation pressure thus making a plant more drought resistant, is also associated with a decrease in the temperature required for ice nucleation in the xylem. Thus the susceptibility of freezing and cavitation are linked together in the xylem of plants. We explain this linkage by the regulation of the sizes of the nuclei catalysing freezing and drought cavitation. Our results offer better understanding of the similarities of adaption of plants to cold and drought stress, and offer new insights into the ability of plants to adapt to the changing environment.

  7. The effects of superoxide dismutase knockout on the oxidative stress parameters and survival of mouse erythrocytes.

    Science.gov (United States)

    Grzelak, Agnieszka; Kruszewski, Marcin; Macierzyńska, Ewa; Piotrowski, Łukasz; Pułaski, Łukasz; Rychlik, Błazej; Bartosz, Grzegorz

    2009-01-01

    The erythrocytes of 12-month old Sod1 (-/-) mice showed an increased level of reactive oxygen species (ROS), as estimated by the degree of dihydroethidine and dihydrorhodamine oxidation, and the increased level of Heinz bodies. No indices of severe oxidative stress were found in the red blood cells and blood plasma of Sod1 (-/-) mice as judged from the lack of significant changes in the levels of erythrocyte and plasma glutathione, plasma protein thiol and carbonyl groups and thiobarbituric-acid reactive substances in the blood plasma. However, a decreased erythrocyte lifespan, increased reticulocyte count and splenomegaly were noted, indicating the importance of superoxide dismutase for maintaining erythrocyte viability. The levels of erythrocyte ROS and Heinz bodies and the reticulocyte count were indistinguishable in Sod1 (+/+) and Sod1 (+/-) mice, suggesting that a superoxide dismutase activity decrease to half of its normal value may be sufficient to secure the protective effects of the enzyme.

  8. Down-regulation of 14-3-3β exerts anti-cancer effects through inducing ER stress in human glioma U87 cells: Involvement of CHOP–Wnt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Lei; Lei, Hui; Chang, Ming-Ze; Liu, Zhi-Qin [Department of Neurological Disease, Xi' an Central Hospital, Xi' an Jiaotong University, Xi' an, Shaanxi 710000 (China); Bie, Xiao-Hua, E-mail: biexiaohua_xjtu@126.com [Department of Functional Neurosurgery, Xi' an Red Cross Hospital, Xi' an Jiaotong University, Xi' an, Shaanxi 710054 (China)

    2015-07-10

    We previously identified 14-3-3β as a tumor-specific isoform of 14-3-3 protein in astrocytoma, but its functional role in glioma cells and underlying mechanisms are poorly understood. In the present study, we investigated the effects of 14-3-3β inhibition in human glioma U87 cells using specific targeted small interfering RNA (siRNA). The results showed that 14-3-3β is highly expressed in U87 cells but not in normal astrocyte SVGp12 cells. Knockdown of 14-3-3β by Si-14-3-3β transfection significantly decreased the cell viability but increased the LDH release in a time-dependent fashion in U87 cells, and these effects were accompanied with G0/G1 cell cycle arrest and apoptosis. In addition, 14-3-3β knockdown induced ER stress in U87 cells, as evidenced by ER calcium release, increased expression of XBP1S mRNA and induction of ER related pro-apoptotic factors. Down-regulation of 14-3-3β significantly decreased the nuclear localization of β-catenin and inhibited Topflash activity, which was shown to be reversely correlated with CHOP. Furthermore, Si-CHOP and sFRP were used to inhibit CHOP and Wnt, respectively. The results showed that the anti-cancer effects of 14-3-3β knockdown in U87 cells were mediated by increased expression of CHOP and followed inhibition of Wnt/β-catenin pathway. In summary, the remarkable efficiency of 14-3-3β knockdown to induce apoptotic cell death in U87 cells may find therapeutic application for the treatment of glioma patients. - Highlights: • Knockdown of 14-3-3β leads to cytotoxicity in human glioma U87 cells. • Knockdown of 14-3-3β induces cell cycle arrest and apoptosis in U87 cells. • Knockdown of 14-3-3β results in ER stress in U87 cells. • Knockdown of 14-3-3β inhibits Wnt/β-catenin pathway via CHOP activation.

  9. Inhibition of HSP90 Promotes Neural Stem Cell Survival from Oxidative Stress through Attenuating NF-κB/p65 Activation

    Directory of Open Access Journals (Sweden)

    Qian Liu

    2016-01-01

    Full Text Available Stem cell survival after transplantation determines the efficiency of stem cell treatment, which develops as a novel potential therapy for several central nervous system (CNS diseases in recent decades. The engrafted stem cells face the damage of oxidative stress, inflammation, and immune response at the lesion point in host. Among the damaging pathologies, oxidative stress directs stem cells to apoptosis and even death through several signalling pathways and DNA damage. However, the in-detail mechanism of stem cell survival from oxidative stress has not been revealed clearly. Here, in this study, we used hydrogen peroxide (H2O2 to induce the oxidative damage on neural stem cells (NSCs. The damage was in consequence demonstrated involving the activation of heat shock protein 90 (HSP90 and NF-κB/p65 signalling pathways. Further application of the pharmacological inhibitors, respectively, targeting at each signalling indicated an upper-stream role of HSP90 upon NF-κB/p65 on NSCs survival. Preinhibition of HSP90 with the specific inhibitor displayed a significant protection on NSCs against oxidative stress. In conclusion, inhibition of HSP90 would attenuate NF-κB/p65 activation by oxidative induction and promote NSCs survival from oxidative damage. The HSP90/NF-κB mechanism provides a new evidence on rescuing NSCs from oxidative stress and also promotes the stem cell application on CNS pathologies.

  10. Peroxisomes: offshoots of the ER.

    Science.gov (United States)

    van der Zand, Adabella; Tabak, Henk F

    2013-08-01

    Peroxisomes are part of the ubiquitous set of eukaryotic organelles. They are small, single membrane bounded vesicles, specialized in the degradation of very-long-chain fatty acids and in synthesis of myelin lipids. Once considered inconspicuous, recent new insights in the formation and function of peroxisomes have revealed a much more subtle interplay between organelles that warrant a re-evaluation of the historical assignment of peroxisomes as being either autonomous or ER-derived. Peroxisomes acquire their lipids and membrane proteins from the ER, whereas they import their matrix proteins directly from the cytosol. Remarkably, many of its metabolic enzymes and factors controlling peroxisome abundance (fission and inheritance) too are shared with other organelles, stressing interdependence among cellular compartments. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Toxin ζ Triggers a Survival Response to Cope with Stress and Persistence

    Directory of Open Access Journals (Sweden)

    María Moreno-del Álamo

    2017-06-01

    Full Text Available Bacteria have evolved complex regulatory controls in response to various environmental stresses. Protein toxins of the ζ superfamily, found in prominent human pathogens, are broadly distributed in nature. We show that ζ is a uridine diphosphate-N-acetylglucosamine (UNAG-dependent ATPase whose activity is inhibited in vitro by stoichiometric concentrations of ε2 antitoxin. In vivo, transient ζ expression promotes a reversible multi-level response by altering the pool of signaling purine nucleotides, which leads to growth arrest (dormancy, although a small cell subpopulation persists rather than tolerating toxin action. High c-di-AMP levels (absence of phosphodiesterase GdpP decrease, and low c-di-AMP levels (absence of diadenylate cyclase DisA increase the rate of ζ persistence. The absence of CodY, a transition regulator from exponential to stationary phase, sensitizes cells to toxin action, and suppresses persisters formed in the ΔdisA context. These changes, which do not affect the levels of stochastic ampicillin (Amp persistence, sensitize cells to toxin and Amp action. Our findings provide an explanation for the connection between ζ-mediated growth arrest (with alterations in the GTP and c-di-AMP pools and persistence formation.

  12. Trypanosoma cruzi Polyamine Transporter: Its Role on Parasite Growth and Survival Under Stress Conditions.

    Science.gov (United States)

    Reigada, Chantal; Sayé, Melisa; Vera, Edward Valera; Balcazar, Darío; Fraccaroli, Laura; Carrillo, Carolina; Miranda, Mariana R; Pereira, Claudio A

    2016-08-01

    Trypanosoma cruzi is the etiological agent of Chagas disease, a major health problem in Latin America. Polyamines are polycationic compounds that play a critical role as regulators of cell growth and differentiation. In contrast with other protozoa, T. cruzi is auxotrophic for polyamines because of its inability to synthesize putrescine due to the lack of both, arginine and ornithine decarboxylase; therefore, the intracellular availability of polyamines depends exclusively on transport processes. In this work, the polyamine transporter TcPAT12 was overexpressed in T. cruzi epimastigotes demonstrating that growth rates at different concentrations of polyamines strongly depend on the regulation of the polyamine transport. In addition, parasites overexpressing TcPAT12 showed a highly increased resistance to hydrogen peroxide and the trypanocidal drugs nifurtimox and benznidazole, which act by oxidative stress and interfering the synthesis of polyamine derivatives, respectively. Finally, the presence of putative polyamine transporters was analyzed in T. cruzi, Trypanosoma brucei, and Leishmania major genomes identifying 3-6 genes in these trypanosomatids.

  13. SERCA control of cell death and survival.

    Science.gov (United States)

    Chemaly, Elie R; Troncone, Luca; Lebeche, Djamel

    2018-01-01

    Intracellular calcium (Ca2+) is a critical coordinator of various aspects of cellular physiology. It is increasingly apparent that changes in cellular Ca2+ dynamics contribute to the regulation of normal and pathological signal transduction that controls cell growth and survival. Aberrant perturbations in Ca2+ homeostasis have been implicated in a range of pathological conditions, such as cardiovascular diseases, diabetes, tumorigenesis and steatosis hepatitis. Intracellular Ca2+ concentrations are therefore tightly regulated by a number of Ca2+ handling enzymes, proteins, channels and transporters located in the plasma membrane and in Ca2+ storage organelles, which work in concert to fine tune a temporally and spatially precise Ca2+ signal. Chief amongst them is the sarco/endoplasmic reticulum (SR/ER) Ca2+ ATPase pump (SERCA) which actively re-accumulates released Ca2+ back into the SR/ER, therefore maintaining Ca2+ homeostasis. There are at least 14 different SERCA isoforms encoded by three ATP2A1-3 genes whose expressions are species- and tissue-specific. Altered SERCA expression and activity results in cellular malignancy and induction of ER stress and ER stress-associated apoptosis. The role of SERCA misregulation in the control of apoptosis in various cell types and disease setting with prospective therapeutic implications is the focus of this review. Ca2+ is a double edge sword for both life as well as death, and current experimental evidence supports a model in which Ca2+ homeostasis and SERCA activity represent a nodal point that controls cell survival. Pharmacological or genetic targeting of this axis constitutes an incredible therapeutic potential to treat different diseases sharing similar biological disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Survival of Listeria monocytogenes in simulated gastrointestinal system and transcriptional profiling of stress- and adhesion-related genes

    DEFF Research Database (Denmark)

    Jiang, Lingli; Olesen, Inger; Andersen, Thomas

    2010-01-01

    survival of L. monocytogenes serotypes 4b and 1=2a strains were higher than that of serotype 1=2c, suggesting that pathogenicity might be related to the viability in the gastrointestinal tract.The transcription levels of prfA and the general stress-related genes clpC, clpE, and clpP were upregulated...

  15. Identification of sigma factor SigmaB-controlled genes and their impact on acid stress, high hydrostatic pressure, and freeze survival in Listeria monocytogenes EGD-e

    NARCIS (Netherlands)

    Wemekamp-Kamphuis, H.H.; Wouters, J.A.; Leeuw, de P.P.L.A.; Hain, T.; Chakraborty, T.; Abee, T.

    2004-01-01

    The gene encoding the alternative sigma factor sigma(B) in Listeria monocytogenes is induced upon exposure of cells to several stresses. In this study, we investigated the impact of a sigB null mutation on the survival of L. monocytogenes EGD-e at low pH, during high-hydrostatic-pressure treatment,

  16. Vreden er over os

    DEFF Research Database (Denmark)

    Mehlsen, Camilla

    2006-01-01

    Urolige elever, cyklister - der giver fuck-finger, aggressive demonstranter. Samtiden er på vej ind i en æra domineret af vrede, siger rektor Lars-Henrik Schmidt, der er aktuel med bogen 'Om vreden'. Udgivelsesdato: Juni...

  17. The Effect of Freezing Stress on Percentage of Electrolytes Leakage and Survival of Flixweed (Descurainia sophia L. Seedlings

    Directory of Open Access Journals (Sweden)

    E Izadi-Darbandi

    2016-10-01

    Full Text Available Introduction Flixweed (Descurainia sophia L. is a medicinal plant from Brassicaceae family which also known as a weed for winter cereals and oil seed rape. Low temperatures are one of the most important abiotic stresses that threat Flixweed growth and productivity. Therefore it is important to recognize the freeze tolerance of Flixweed for successful planting and utilization in cold regions such as Mashhad in Khorasan Razavi Province (Iran’s north. east. Among many laboratory methods which have been developed to estimate and to evaluate plants response or their tolerance to freez¬ing temperatures, electrolyte leakage (EL test is widely used. This test is based on this principle that damage to the cell membranes results in enhanced leakage of solutes into the apoplastic water, hence recording the amount of leakage after stress treatments provides an estimation of tissue injury. Indeed continuing integration of plasma membrane is one important factor for survival of plants under freezing stress and any disturbance in membrane structure can lead to damage and death. So determination of LT50 point or critical temperature for electrolytes leakage and survival of plant is the most reliable, quantitative and simple methods for evaluating the cold tolerance of plants. The aim of this trial was to determine the LT50 according to the EL and SU% for Flixweed ecotypes. Materials and Methods In order to evaluate freeze tolerance in Flixweed, a factorial experiment based on completely randomized design with three replications was carried out in college of agriculture, Ferdowsi University of Mashhad. Experimental factors included five ecotypes of Flixweed (Eghlid, Sabzewar, Hamedan, Torbat-e-Jam and Neyshabour and 10 freezing temperature levels (0, -2,-4, -6, -8,-10,-12,-14,-16 and -18°C. Flixweed seeds were cultivated in pots in autumn of 2008 and were grown until 5-7 leaf stage under natural weather conditions for acclimation. Then to apply freezing

  18. Apoptosis of HeLa cells induced by a new targeting photosensitizer-based PDT via a mitochondrial pathway and ER stress.

    Science.gov (United States)

    Li, Donghong; Li, Lei; Li, Pengxi; Li, Yi; Chen, Xiangyun

    2015-01-01

    Photodynamic therapy (PDT) is emerging as a viable treatment for many cancers. To decrease the cutaneous photosensitivity induced by PDT, many attempts have been made to search for a targeting photosensitizer; however, few reports describe the molecular mechanism of PDT mediated by this type of targeting photosensitizer. The present study aimed to investigate the molecular mechanism of PDT induced by a new targeting photosensitizer (PS I), reported previously by us, on HeLa cells. Apoptosis is the primary mode of HeLa cell death in our system, and apoptosis occurs in a manner dependent on concentration, irradiation dose, and drug-light intervals. After endocytosis mediated by the folate receptor, PS I was primarily localized to the mitochondria and the endoplasmic reticulum (ER) of HeLa cells. PS I PDT resulted in rapid increases in intracellular reactive oxygen species (ROS) production and Ca(2+) concentration, both of which reached a peak nearly simultaneously at 15 minutes, followed by the loss of mitochondrial membrane potential at 30 minutes, release of cytochrome c from mitochondria into the cytoplasm, downregulation of Bcl-2 expression, and upregulation of Bax expression. Meanwhile, activation of caspase-3, -9, and -12, as well as induction of C/EBP homologous protein (CHOP) and glucose-regulated protein (GRP78), in HeLa cells after PS I PDT was also detected. These results suggest that apoptosis of HeLa cells induced by PS I PDT is not only triggered by ROS but is also regulated by Ca(2+) overload. Mitochondria and the ER serve as the subcellular targets of PS I PDT, the effective activation of which is responsible for PS I PDT-induced apoptosis in HeLa cells.

  19. Development of an Effective Transport Media for Juvenile Spring Chinook Salmon to Mitigate Stress and Improve Smolt Survival During Columbia River Fish Hauling Operations, 1985 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wedemeyer, Gary A.

    1985-02-01

    Selected transport media consisting of mineral salt additions (Na/sup +/, Cl/sup -/, Ca/sup + +/, PO/sub 4//sup -3/, HCO/sub 3//sup -/, and Mg/sup + +/), mineral salts plus tranquilizing concentrations of tricaine methane sulfonate (MS-222), or MS-222 alone were tested for their ability to mitigate stress and increase smolt survival during single and mixed species hauling of Columbia River spring chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Salmo gairdneri). Successful stress mitigation was afforded by several formulations as indicated by protection against life-threatening osmoregulatory and other physiological dysfunctions, and against immediate and delayed hauling mortality. Effects on the seawater survival and growth of smolts hauled in transport media were used as the overall criterion of success. Of the fourteen chemical formulations tested, 10 ppM MS-222 emerged as top-rated in terms of ability to mitigate physiological stress during single and mixed species transport of juvenile spring chinook salmon at hauling densities of 0.5 or 1.0 lb/gallon. Immediate and delayed mortalities from hauling stress were also reduced, but benefits to early marine growth and survival were limited to about the first month in seawater. The two physical factors tested (reduced light intensity and water temperature) were generally less effective than mineral salt additions in mitigating hauling stress, but the degree of protection afforded by reduced light intensity was nevertheless judged to be physiologically beneficial. 36 refs., 1 fig., 19 tabs.

  20. High-fructose diet is as detrimental as high-fat diet in the induction of insulin resistance and diabetes mediated by hepatic/pancreatic endoplasmic reticulum (ER) stress.

    Science.gov (United States)

    Balakumar, M; Raji, L; Prabhu, D; Sathishkumar, C; Prabu, P; Mohan, V; Balasubramanyam, M

    2016-12-01

    In the context of high human consumption of fructose diets, there is an imperative need to understand how dietary fructose intake influence cellular and molecular mechanisms and thereby affect β-cell dysfunction and insulin resistance. While evidence exists for a relationship between high-fat-induced insulin resistance and metabolic disorders, there is lack of studies in relation to high-fructose diet. Therefore, we attempted to study the effect of different diets viz., high-fat diet (HFD), high-fructose diet (HFS), and a combination (HFS + HFD) diet on glucose homeostasis and insulin sensitivity in male Wistar rats compared to control animals fed with normal pellet diet. Investigations include oral glucose tolerance test, insulin tolerance test, histopathology by H&E and Masson's trichrome staining, mRNA expression by real-time PCR, protein expression by Western blot, and caspase-3 activity by colorimetry. Rats subjected to high-fat/fructose diets became glucose intolerant, insulin-resistant, and dyslipidemic. Compared to control animals, rats subjected to different combination of fat/fructose diets showed increased mRNA and protein expression of a battery of ER stress markers both in pancreas and liver. Transcription factors of β-cell function (INSIG1, SREBP1c and PDX1) as well as hepatic gluconeogenesis (FOXO1 and PEPCK) were adversely affected in diet-induced insulin-resistant rats. The convergence of chronic ER stress towards apoptosis in pancreas/liver was also indicated by increased levels of CHOP mRNA & increased activity of both JNK and Caspase-3 in rats subjected to high-fat/fructose diets. Our study exposes the experimental support in that high-fructose diet is equally detrimental in causing metabolic disorders.

  1. Tetraselmis chuii biomass as a potential feed additive to improve survival and oxidative stress status of Pacific white-leg shrimp Litopenaeus vannamei postlarvae

    Directory of Open Access Journals (Sweden)

    Norazira Abdu Rahman

    2017-08-01

    Full Text Available Abstract Shrimp is an important traded fishery commodity. When subjected to stress, shrimp usually suffers from oxidative stress, which leads to cell injury, senescence, and death. To maintain shrimp good health, performance and production, antioxidant and immune systems are important. Natural antioxidants found in microalgae may be used to increase the cell protection against oxidative damage, being a promising alternative to the carcinogenic synthetic antioxidants. In this study, Tetraselmis chuii was evaluated for its effect on survival, growth and oxidative stress biomarkers on Litopenaeus vannamei postlarvae (PL. The antioxidant properties of the formulated feed with T. chuii inclusion were determined using four antioxidant chemical assays. Meanwhile, the oxidative stress biomarkers on PL were analyzed by hydrogen peroxide, membrane stability and lipid peroxidation assays. Results showed that PL reared on diets supplemented with 50% T. chuii had a significantly higher (P ≤ 0.05 survival (97.6 ± 1.4% and lower oxidative stress in terms of hydrogen peroxide content (10.08 ± 0.4 mM g−1 FW and electrolyte leakage (10.8 ± 0.3%. The result of this study also showed that shrimp PL reared on diets supplemented with microalgal, T. chuii have high resistance to reverse salinity stress test (76.7–100%. However, no significant differences (P ≥ 0.05 were found in the growth and lipid peroxidation. Due to the positive effect on oxidative stress status, survival and resistance to salinity stress, the feeding of L. vannamei PL with diet containing at least 50% of T. chuii is recommended as a natural source of antioxidant for PL.

  2. Endoplasmic Reticulum Stress: Its Role in Disease and Novel Prospects for Therapy

    Science.gov (United States)

    Schönthal, Axel H.

    2012-01-01

    The endoplasmic reticulum (ER) is a multifunctional organelle required for lipid biosynthesis, calcium storage, and protein folding and processing. A number of physiological and pathological conditions, as well as a variety of pharmacological agents, are able to disturb proper ER function and thereby cause ER stress, which severely impairs protein folding and therefore poses the risk of proteotoxicity. Specific triggers for ER stress include, for example, particular intracellular alterations (e.g., calcium or redox imbalances), certain microenvironmental conditions (e.g., hypoglycemia, hypoxia, and acidosis), high-fat and high-sugar diet, a variety of natural compounds (e.g., thapsigargin, tunicamycin, and geldanamycin), and several prescription drugs (e.g., bortezomib/Velcade, celecoxib/Celebrex, and nelfinavir/Viracept). The cell reacts to ER stress by initiating a defensive process, called the unfolded protein response (UPR), which is comprised of cellular mechanisms aimed at adaptation and safeguarding cellular survival or, in cases of excessively severe stress, at initiation of apoptosis and elimination of the faulty cell. In recent years, this dichotomic stress response system has been linked to several human diseases, and efforts are underway to develop approaches to exploit ER stress mechanisms for therapy. For example, obesity and type 2 diabetes have been linked to ER stress-induced failure of insulin-producing pancreatic beta cells, and current research efforts are aimed at developing drugs that ameliorate cellular stress and thereby protect beta cell function. Other studies seek to pharmacologically aggravate chronic ER stress in cancer cells in order to enhance apoptosis and achieve tumor cell death. In the following, these principles will be presented and discussed. PMID:24278747

  3. Endoplasmic Reticulum Stress Signaling in Mammalian Oocytes and Embryos: Life in the Balance

    Science.gov (United States)

    Latham, Keith E.

    2015-01-01

    Mammalian oocytes and embryos are exquisitely sensitive to a wide range of insults related to physical stress, chemical exposure, and exposures to adverse maternal nutrition or health status. Although cells manifest specific responses to various stressors, many of these stressors intersect at the endoplasmic reticulum, where disruptions in protein folding and production of reactive oxygen species initiate downstream signaling events. These signals modulate mRNA translation and gene transcription, leading to recovery, activation of autophagy, or with severe and prolonged stress, apoptosis. ER stress signaling has recently come to the fore as a major contributor to embryo demise. Accordingly, agents that modulate or inhibit ER stress signaling have yielded beneficial effects on embryo survival and long-term developmental potential. We review here the mechanisms of ER stress signaling, their connections to mammalian oocytes and embryos, and the promising indications that interventions in this pathway may provide new opportunities for improving mammalian reproduction and health. PMID:25805126

  4. Apoptosis of HeLa cells induced by a new targeting photosensitizer-based PDT via a mitochondrial pathway and ER stress

    Directory of Open Access Journals (Sweden)

    Li D

    2015-04-01

    Full Text Available Donghong Li,1 Lei Li,2 Pengxi Li,1 Yi Li,3 Xiangyun Chen1 1State Key Laboratory of Trauma, Burn and Combined Injury, The Second Department of Research Institute of Surgery, 2The First Department of Research Institute of Surgery, 3Cancer Center, Daping Hospital, Third Military Medical University, Chongqing, People’s Republic of China Abstract: Photodynamic therapy (PDT is emerging as a viable treatment for many cancers. To decrease the cutaneous photosensitivity induced by PDT, many attempts have been made to search for a targeting photosensitizer; however, few reports describe the molecular mechanism of PDT mediated by this type of targeting photosensitizer. The present study aimed to investigate the molecular mechanism of PDT induced by a new targeting photosensitizer (PS I, reported previously by us, on HeLa cells. Apoptosis is the primary mode of HeLa cell death in our system, and apoptosis occurs in a manner dependent on concentration, irradiation dose, and drug–light intervals. After endocytosis mediated by the folate receptor, PS I was primarily localized to the mitochondria and the endoplasmic reticulum (ER of HeLa cells. PS I PDT resulted in rapid increases in intracellular reactive oxygen species (ROS production and Ca2+ concentration, both of which reached a peak nearly simultaneously at 15 minutes, followed by the loss of mitochondrial membrane potential at 30 minutes, release of cytochrome c from mitochondria into the cytoplasm, downregulation of Bcl-2 expression, and upregulation of Bax expression. Meanwhile, activation of caspase-3, -9, and -12, as well as induction of C/EBP homologous protein (CHOP and glucose-regulated protein (GRP78, in HeLa cells after PS I PDT was also detected. These results suggest that apoptosis of HeLa cells induced by PS I PDT is not only triggered by ROS but is also regulated by Ca2+ overload. Mitochondria and the ER serve as the subcellular targets of PS I PDT, the effective activation of which

  5. GTx-822, an ER{beta}-selective agonist, protects retinal pigment epithelium (ARPE-19) from oxidative stress by activating MAPK and PI3-K pathways.

    Science.gov (United States)

    Giddabasappa, Anand; Bauler, Matthew N; Barrett, Christina M; Coss, Christopher C; Wu, Zhongzhi; Miller, Duane D; Dalton, James T; Eswaraka, Jeetendra R

    2010-11-01

    The goal of this study was to determine whether an estrogen receptor-β (ERβ)-selective agonist (GTx-822; GTx, Inc., Memphis, TN) could prevent hydrogen peroxide (H(2)O(2))-induced oxidative stress in ARPE-19 cells and to elucidate the molecular pathways involved in this protection. The selectivity of GTx-822 for ERβ was determined by receptor-binding assay (RBA) and transactivation assay. Cultured ARPE-19 cells were subjected to oxidative stress with t-butyl hydroxide (t-BH) or hydrogen peroxide (H(2)O(2)) in the presence and absence of GTx-822. Reactive oxygen species (ROS) was measured by using H(2)DCFDA fluorescence. Apoptosis was evaluated by cell death ELISA. Mitochondrial membrane potential was measured with the JC-1 assay. Gene expression and protein expression and activation were quantitated with qRT-PCR and Western blot analysis. Phospho-protein arrays elucidated the activation of protein kinases. The RBA and transactivation assay revealed that GTx-822 is an ERβ-selective agonist (K(i) = 0.53 nM). GTx-822 prevented oxidative stress in ARPE-19 cells. It preserved mitochondrial function and prevented cellular apoptosis. Pretreatment with GTx-822 increased ERβ gene and protein expression during oxidative stress. Upregulation of the phase II antioxidant genes GPx-2 and HO-1 was also seen in an ERβ-dependent mechanism. GTx-822 pretreatment induced phosphorylation of ERK1/2, PI3-K, and Bad. This is the first report to show that GTx-822, an ERβ agonist, can protect ARPE-19 cells from the cellular apoptosis induced by oxidative stress. GTx-822 mediated cytoprotection was mediated through induction of both genomic and nongenomic pathways. The results of this study open new avenues for the use of a selective ERβ agonist in treatment of ocular diseases like AMD where oxidative stress plays a major role in disease pathogenesis.

  6. The ribokinases of Arabidopsis thaliana and Saccharomyces cerevisiae are required for ribose recycling from nucleotide catabolism, which in plants is not essential to survive prolonged dark stress.

    Science.gov (United States)

    Schroeder, Rebekka Y; Zhu, Anting; Eubel, Holger; Dahncke, Kathleen; Witte, Claus-Peter

    2017-09-18

    Nucleotide catabolism in Arabidopsis thaliana and Saccharomyces cerevisiae leads to the release of ribose, which requires phosphorylation to ribose-5-phosphate mediated by ribokinase (RBSK). We aimed to characterize RBSK in plants and yeast, to quantify the contribution of plant nucleotide catabolism to the ribose pool, and to investigate whether ribose carbon contributes to dark stress survival of plants. We performed a phylogenetic analysis and determined the kinetic constants of plant-expressed Arabidopsis and yeast RBSKs. Using mass spectrometry, several metabolites were quantified in AtRBSK mutants and double mutants with genes of nucleoside catabolism. Additionally, the dark stress performance of several nucleotide metabolism mutants and rbsk was compared. The plant PfkB family of sugar kinases forms nine major clades likely representing distinct biochemical functions, one of them RBSK. Nucleotide catabolism is the dominant ribose source in plant metabolism and is highly induced by dark stress. However, rbsk cannot be discerned from the wild type in dark stress. Interestingly, the accumulation of guanosine in a guanosine deaminase mutant strongly enhances dark stress symptoms. Although nucleotide catabolism contributes to carbon mobilization upon darkness and is the dominant source of ribose, the contribution appears to be of minor importance for dark stress survival. © 2017 The Authors New Phytologist © 2017 New Phytologist Trust.

  7. Synbiotic Amazonian palm berry (açai, Euterpe oleracea Mart.) ice cream improved Lactobacillus rhamnosus GG survival to simulated gastrointestinal stress.

    Science.gov (United States)

    Costa, Mayra Garcia Maia; Ooki, Gabriela Namur; Vieira, Antônio Diogo Silva; Bedani, Raquel; Saad, Susana Marta Isay

    2017-02-22

    The effect of açai pulp ice cream and of its supplementation with inulin (I), whey protein concentrate (WC), and/or whey protein isolate (WI) on the viability and resistance to simulated gastrointestinal stress of the probiotic Lactobacillus (Lb.) rhamnosus GG strain throughout storage at -18 °C for up to 112 days was evaluated and morphological changes during stress were monitored. Lb. rhamnosus GG viability was stable in all formulations for up to 112 days of storage, preserving populations around 9 log CFU g-1. Compared to the fresh culture, Lb. rhamnosus GG showed higher survival under simulated gastrointestinal conditions when incorporated into açai ice cream, indicating that the presence of the food matrix contributed to the microorganism survival. A reduction of at least 5 log cycles of Lb. rhamnosus GG was observed in all formulations after the gastrointestinal simulation in all storage periods assessed. The addition of I, WC, and/or WI did not show any significant effect on the probiotic survival under simulated gastrointestinal stress (p ice cream. Thus, the açai pulp ice cream was shown to be a suitable matrix for Lb. rhamnosus GG, improving its survival under in vitro simulated gastrointestinal conditions.

  8. Hvor anvendelig er PKI?

    OpenAIRE

    Nielsen, Jon Magne

    2006-01-01

    Denne oppgaven ser på bruken av elektronisk ID i statlige etater i Norge i dag. Det ses spesielt på om bruken av tekologien PKI er en god løsning på etatenes behov på dette området. Som utgangspunkt for analysen er det sett spesielt på to statlige etater. Disse etatenes behov og bruk av elektronisk ID generelt og PKI spesielt blir undersøkt. Det er videre gjort rede for hvilke lover, forskrifter og andre førende dokumenter som danner de formelle rammebetingelsene for etaters bruk av PKI. ...

  9. Physical condition and stress levels during early development reflect feeding rates and predict pre- and post-fledging survival in a nearshore seabird

    Science.gov (United States)

    Lamb, Juliet S.; O'Reilly, Kathleen M.; Jodice, Patrick G.R.

    2016-01-01

    The effects of acute environmental stressors on reproduction in wildlife are often difficult to measure because of the labour and disturbance involved in collecting accurate reproductive data. Stress hormones represent a promising option for assessing the effects of environmental perturbations on altricial young; however, it is necessary first to establish how stress levels are affected by environmental conditions during development and whether elevated stress results in reduced survival and recruitment rates. In birds, the stress hormone corticosterone is deposited in feathers during the entire period of feather growth, making it an integrated measure of background stress levels during development. We tested the utility of feather corticosterone levels in 3- to 4-week-old nestling brown pelicans (Pelecanus occidentalis) for predicting survival rates at both the individual and colony levels. We also assessed the relationship of feather corticosterone to nestling body condition and rates of energy delivery to nestlings. Chicks with higher body condition and lower corticosterone levels were more likely to fledge and to be resighted after fledging, whereas those with lower body condition and higher corticosterone levels were less likely to fledge or be resighted after fledging. Feather corticosterone was also associated with intracolony differences in survival between ground and elevated nest sites. Colony-wide, mean feather corticosterone predicted nest productivity, chick survival and post-fledging dispersal more effectively than did body condition, although these relationships were strongest before fledglings dispersed away from the colony. Both reproductive success and nestling corticosterone were strongly related to nutritional conditions, particularly meal delivery rates. We conclude that feather corticosterone is a powerful predictor of reproductive success and could provide a useful metric for rapidly assessing the effects of changes in environmental

  10. Virulence Factors of Pseudomonas aeruginosa Induce Both the Unfolded Protein and Integrated Stress Responses in Airway Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Emily F A van 't Wout

    2015-06-01

    Full Text Available Pseudomonas aeruginosa infection can be disastrous in chronic lung diseases such as cystic fibrosis and chronic obstructive pulmonary disease. Its toxic effects are largely mediated by secreted virulence factors including pyocyanin, elastase and alkaline protease (AprA. Efficient functioning of the endoplasmic reticulum (ER is crucial for cell survival and appropriate immune responses, while an excess of unfolded proteins within the ER leads to "ER stress" and activation of the "unfolded protein response" (UPR. Bacterial infection and Toll-like receptor activation trigger the UPR most likely due to the increased demand for protein folding of inflammatory mediators. In this study, we show that cell-free conditioned medium of the PAO1 strain of P. aeruginosa, containing secreted virulence factors, induces ER stress in primary bronchial epithelial cells as evidenced by splicing of XBP1 mRNA and induction of CHOP, GRP78 and GADD34 expression. Most aspects of the ER stress response were dependent on TAK1 and p38 MAPK, except for the induction of GADD34 mRNA. Using various mutant strains and purified virulence factors, we identified pyocyanin and AprA as inducers of ER stress. However, the induction of GADD34 was mediated by an ER stress-independent integrated stress response (ISR which was at least partly dependent on the iron-sensing eIF2α kinase HRI. Our data strongly suggest that this increased GADD34 expression served to protect against Pseudomonas-induced, iron-sensitive cell cytotoxicity. In summary, virulence factors from P. aeruginosa induce ER stress in airway epithelial cells and also trigger the ISR to improve cell survival of the host.

  11. Metabolomics er fremtiden

    DEFF Research Database (Denmark)

    Pedersern, Birger

    2010-01-01

    Forskningen i fødevarer har fået et potent redskab i hånden. Metabolomics er vejen frem, mener professor Søren Balling Engelsen fra Københavns Universitet......Forskningen i fødevarer har fået et potent redskab i hånden. Metabolomics er vejen frem, mener professor Søren Balling Engelsen fra Københavns Universitet...

  12. TNF-α promotes survival and migration of MSCs under oxidative stress via NF-κB pathway to attenuate intimal hyperplasia in vein grafts.

    Science.gov (United States)

    Bai, Xiao; Xi, Jie; Bi, Yanwen; Zhao, Xin; Bing, Weidong; Meng, Xiangbin; Liu, Yimin; Zhu, Zhonglai; Song, Guangmin

    2017-09-01

    The oxidative stress caused by endothelial injury is involved in intimal hyperplasia (IH) in vein grafts. Mesenchymal stem cells (MSCs) can home to injured intima and promote endothelial repair. However, MSC apoptosis is increased accompanied by decreased functional activity under oxidative stress. Thus, we investigate whether tumour necrosis factor-α (TNF-α) can promote the survival and activity of MSCs under oxidative stress to reduce IH more effectively, and establish what role the NF-κB pathway plays in this. In this study, we preconditioned MSCs with TNF-α ( TNF -α-PC MSCs) for 24 hrs and measured the activation of the IKK/NF-κB pathway. EdU and transwell assays were performed to assess proliferation and migration of TNF -α-PC MSCs. Apoptosis and migration of TNF -α- PC MSCs were evaluated in conditions of oxidative stress by analysis of the expression of Bcl-2 and CXCR4 proteins. TNF -α- PC MSCs were transplanted into a vein graft model, so that cell homing could be tracked, and endothelial apoptosis and IH of vein grafts were measured. The results demonstrated that TNF-α promotes proliferation and migration of MSCs. Furthermore, survival and migration of TNF -α- PC MSCs under oxidative stress were both enhanced. A greater number of MSCs migrated to the intima of vein grafts after preconditioning with TNF-α, and the formation of neointima was significantly reduced. These effects could be partially abolished by IKK XII (NF-κB inhibitor). All these results indicate that preconditioning with TNF-α can promote survival and migration of MSCs under oxidative stress via the NF-κB pathway and thus attenuate IH of vein grafts. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  13. CCNA2 Is a Prognostic Biomarker for ER+ Breast Cancer and Tamoxifen Resistance

    OpenAIRE

    Gao, Tian; Han, Yong; Yu, Ling; Ao, Sheng; Li, Ziyu; Ji, Jiafu

    2014-01-01

    Identification of effective prognostic biomarkers and targets are of crucial importance to the management of estrogen receptor positive (ER+) breast cancer. CCNA2 (also known as CyclinA2) belongs to the highly conserved cyclin family and is significantly overexpressed in various cancer types. In this study, we demonstrated that CCNA2 had significant predictive power in distant metastasis free survival, disease free survival, recurrence free survival and overall survival of ER+ breast cancer p...

  14. Cascading effects from survival to physiological activities, and gene expression of heat shock protein 90 on the abalone Haliotis discus hannai responding to continuous thermal stress.

    Science.gov (United States)

    Park, Kiyun; Lee, Jung Sick; Kang, Ju-Chan; Kim, Jae Won; Kwak, Ihn-Sil

    2015-02-01

    Increasing temperatures can be a significant stressor for aquatic organisms. Abalones, a type of large marine gastropods, are the most commercially important species in aquaculture for Asia. To evaluate the potential ecological risk posed by temperature stress, we measured biological responses such as survival rate, adhesion ability (falling rate), and foot abnormalities in the abalone Haliotis discus hannai. Additionally, biochemical and molecular responses were evaluated in H. discus hannai exposed to various temperature gradients. The survival rate was reduced in abalones exposed to relative high temperatures (more than 26 °C). Increased temperature stress induced a higher falling rate and abnormal foot structure. Furthermore, increased antioxidant enzyme activities were observed in abalones exposed to relative high temperatures (26 and 28 °C). The activities of superoxide dismutase were induced in a time-dependent manner after high temperature stress. Generally, heat shock protein 90 also increased significantly in H. discus hannai exposed to temperature gradients (more than 24 °C) for 12 h. These results provide valuable information regarding stress responses to increased temperatures, in H. discus hannai: adverse biological and molecular outcomes could be utilized as risk assessments and stress monitoring of marine ecosystems under increased water temperatures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Inhibition of Starvation-Triggered Endoplasmic Reticulum Stress, Autophagy, and Apoptosis in ARPE-19 Cells by Taurine through Modulating the Expression of Calpain-1 and Calpain-2.

    Science.gov (United States)

    Zhang, Yuanyuan; Ren, Shu; Liu, Yuci; Gao, Kun; Liu, Zheng; Zhang, Zhou

    2017-10-14

    Age-related macular degeneration (AMD) is a complex disease with multiple initiators and pathways that converge on death for retinal pigment epithelial (RPE) cells. In this study, effects of taurine on calpains, autophagy, endoplasmic reticulum (ER) stress, and apoptosis in ARPE-19 cells (a human RPE cell line) were investigated. We first confirmed that autophagy, ER stress and apoptosis in ARPE-19 cells were induced by Earle's balanced salt solution (EBSS) through starvation to induce RPE metabolic stress. Secondly, inhibition of ER stress by 4-phenyl butyric acid (4-PBA) alleviated autophagy and apoptosis, and suppression of autophagy by 3-methyl adenine (3-MA) reduced the cell apoptosis, but the ER stress was minimally affected. Thirdly, the apoptosis, ER stress and autophagy were inhibited by gene silencing of calpain-2 and overexpression of calpain-1, respectively. Finally, taurine suppressed both the changes of the important upstream regulators (calpain-1 and calpain-2) and the activation of ER stress, autophagy and apoptosis, and taurine had protective effects on the survival of ARPE-19 cells. Collectively, this data indicate that taurine inhibits starvation-triggered endoplasmic reticulum stress, autophagy, and apoptosis in ARPE-19 cells by modulating the expression of calpain-1 and calpain-2.

  16. Inhibition of Starvation-Triggered Endoplasmic Reticulum Stress, Autophagy, and Apoptosis in ARPE-19 Cells by Taurine through Modulating the Expression of Calpain-1 and Calpain-2

    Directory of Open Access Journals (Sweden)

    Yuanyuan Zhang

    2017-10-01

    Full Text Available Age-related macular degeneration (AMD is a complex disease with multiple initiators and pathways that converge on death for retinal pigment epithelial (RPE cells. In this study, effects of taurine on calpains, autophagy, endoplasmic reticulum (ER stress, and apoptosis in ARPE-19 cells (a human RPE cell line were investigated. We first confirmed that autophagy, ER stress and apoptosis in ARPE-19 cells were induced by Earle’s balanced salt solution (EBSS through starvation to induce RPE metabolic stress. Secondly, inhibition of ER stress by 4-phenyl butyric acid (4-PBA alleviated autophagy and apoptosis, and suppression of autophagy by 3-methyl adenine (3-MA reduced the cell apoptosis, but the ER stress was minimally affected. Thirdly, the apoptosis, ER stress and autophagy were inhibited by gene silencing of calpain-2 and overexpression of calpain-1, respectively. Finally, taurine suppressed both the changes of the important upstream regulators (calpain-1 and calpain-2 and the activation of ER stress, autophagy and apoptosis, and taurine had protective effects on the survival of ARPE-19 cells. Collectively, this data indicate that taurine inhibits starvation-triggered endoplasmic reticulum stress, autophagy, and apoptosis in ARPE-19 cells by modulating the expression of calpain-1 and calpain-2.

  17. Endoplasmic Reticulum Stress-Related Inflammation and Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Tomomi Gotoh

    2011-01-01

    Full Text Available The endoplasmic reticulum (ER is the site of synthesis and maturation of proteins designed for secretion or for localization on the cell membrane. Various types of stress from both inside and outside cells disturb ER function, thus causing unfolded or misfolded proteins to accumulate in the ER. To improve and maintain the ER functions against such stresses, the ER stress response pathway is activated. However, when the stress is prolonged or severe, apoptosis pathways are activated to remove damaged cells. It was recently reported that the ER stress pathway is also involved in the inflammatory response, whereby inflammation induces ER stress, and ER stress induces an inflammatory response. Therefore, the ER stress response pathway is involved in various diseases, including cardiovascular diseases such as atherosclerosis and ischemic diseases, in various ways. The ER stress pathway may represent a novel target for the treatment of these diseases.

  18. Jeg Er blevet FRANKofil

    DEFF Research Database (Denmark)

    Andersson, Lasse

    2014-01-01

    afhængig af Frank Underwood fra serien House of Cards på den fremadstormende TV-streamingstjenesten Netflix. Jeg har opdaget et nyt internetbaseret datingforhold. Et surrealt, fedt miks af det kyniske og joviale personificeret i karakteren Frank Underwood, som er helt igennem ubehagelig, men fantastisk...... spillet af Kevin Spacey. Og tak til Spacey der for en tid har forladt teateret ’The Old Vic’ i London for at begejstre mig. Der er generelt to årsager til mine FRANKofile tilbøjeligheder. For det første er Netflix’s remake af den tyve år gamle BBC serie House of Cards efter min menig et stykke tv...... anden grund, til at jeg er blevet Frankofil, er, at jeg ikke skal sidde og vente på næste søndag efter søndag efter søndag for at få lov at se næste afsnit. Netflix lagde alle tretten timer af sæson 2 ud på nettet. Jeg afgør selv, hvornår jeg skal have mere Frank! Men på trods af mit narkomanlignende...

  19. Innovation er brugerdreven!

    DEFF Research Database (Denmark)

    Helms, Niels Henrik

    2008-01-01

    Brugerdreven innovation er blevet svaret på mange af de udfordringer, som vores moderne samfund står overfor.Det er skrevet ind i såvel regeringsgrundlaget som i de forskellige tiltag, som skal ruste Danmark i forhold til globaliseringen. Vi har ifølge argumentationen her enrække særlige forudsæt......Brugerdreven innovation er blevet svaret på mange af de udfordringer, som vores moderne samfund står overfor.Det er skrevet ind i såvel regeringsgrundlaget som i de forskellige tiltag, som skal ruste Danmark i forhold til globaliseringen. Vi har ifølge argumentationen her enrække særlige...... forudsætninger: samspillet mellem virksomhederne, samspillet mellem forskning, virksomheder og fx erhvervspolitiske tiltag, den særlige danske designtradition. Samtidig er det netop innovationen og især den brugerdrevne innovation, som giver og isærdeleshed skal give Danmark en rolle i en globaliseret økonomi...

  20. Honey bee (Apis mellifera) drones survive oxidative stress due to increased tolerance instead of avoidance or repair of oxidative damage

    Science.gov (United States)

    Oxidative stress can lead to premature aging symptoms and cause acute mortality at higher doses in a range of organisms. Oxidative stress resistance and longevity are mechanistically and phenotypically linked: considerable variation in oxidative stress resistance exists among and within species and ...

  1. Small-Molecule Inhibition of Rho/MKL/SRF Transcription in Prostate Cancer Cells: Modulation of Cell Cycle, ER Stress, and Metastasis Gene Networks

    Directory of Open Access Journals (Sweden)

    Chris R. Evelyn

    2016-05-01

    Full Text Available Metastasis is the major cause of cancer deaths and control of gene transcription has emerged as a critical contributing factor. RhoA- and RhoC-induced gene transcription via the actin-regulated transcriptional co-activator megakaryocytic leukemia (MKL and serum response factor (SRF drive metastasis in breast cancer and melanoma. We recently identified a compound, CCG-1423, which blocks Rho/MKL/SRF-mediated transcription and inhibits PC-3 prostate cancer cell invasion. Here, we undertook a genome-wide expression study in PC-3 cells to explore the mechanism and function of this compound. There was significant overlap in the genes modulated by CCG-1423 and Latrunculin B (Lat B, which blocks the Rho/MKL/SRF pathway by preventing actin polymerization. In contrast, the general transcription inhibitor 5,6-dichloro-1-β-d-ribofuranosyl-1H-benzimidazole (DRB showed a markedly different pattern. Effects of CCG-1423 and Lat B on gene expression correlated with literature studies of MKL knock-down. Gene sets involved in DNA synthesis and repair, G1/S transition, and apoptosis were modulated by CCG-1423. It also upregulated genes involved in endoplasmic reticulum stress. Targets of the known Rho target transcription factor family E2F and genes related to melanoma progression and metastasis were strongly suppressed by CCG-1423. These results confirm the ability of our compound to inhibit expression of numerous Rho/MKL-dependent genes and show effects on stress pathways as well. This suggests a novel approach to targeting aggressive cancers and metastasis.

  2. Sphingolipids activate the endoplasmic reticulum stress surveillance pathway.

    Science.gov (United States)

    Piña, Francisco; Yagisawa, Fumi; Obara, Keisuke; Gregerson, J D; Kihara, Akio; Niwa, Maho

    2018-01-09

    Proper inheritance of functional organelles is vital to cell survival. In the budding yeast, Saccharomyces cerevisiae, the endoplasmic reticulum (ER) stress surveillance (ERSU) pathway ensures that daughter cells inherit a functional ER. Here, we show that the ERSU pathway is activated by phytosphingosine (PHS), an early biosynthetic sphingolipid. Multiple lines of evidence support this: (1) Reducing PHS levels with myriocin diminishes the ability of cells to induce ERSU phenotypes. (2) Aureobasidin A treatment, which blocks conversion of early intermediates to downstream complex sphingolipids, induces ERSU. (3) orm1Δorm2Δ cells, which up-regulate PHS, show an ERSU response even in the absence of ER stress. (4) Lipid analyses confirm that PHS levels are indeed elevated in ER-stressed cells. (5) Lastly, the addition of exogenous PHS is sufficient to induce all ERSU phenotypes. We propose that ER stress elevates PHS, which in turn activates the ERSU pathway to ensure future daughter-cell viability. © 2018 Piña et al.

  3. Tale er guld

    DEFF Research Database (Denmark)

    Juel Henrichsen, Peter

    2014-01-01

    Mange danske kommuner er parate til at indfase automatisk talegenkendelse, men er samtidig nervøse efter en lang række dårlige businesscases i den nærmere fortid. Der klages over høje licenspriser og lavt serviceniveau, den typiske virkning af et de facto monopol på leverandørsiden. Denne artikel...... området - som vi håber at se i 2014 - en begivenhed som præcis kunne løsne den nuværende deadlock og åbne et milliardstort marked for taleteknologi i det offentliges tjeneste....

  4. Bioenergi er blevet moderne

    DEFF Research Database (Denmark)

    Sønderberg Petersen, L.

    2003-01-01

    Risø har udgivet en rapport om moderne bioenergi. Den slår fast, at biomasse er en ligeså værdifuld ressource som vind, og at Danmark vil kunne spille en væsentlig rolle i udviklingen af den teknologi, der skal til for at udnytte hele dens potentiale.......Risø har udgivet en rapport om moderne bioenergi. Den slår fast, at biomasse er en ligeså værdifuld ressource som vind, og at Danmark vil kunne spille en væsentlig rolle i udviklingen af den teknologi, der skal til for at udnytte hele dens potentiale....

  5. Dominant ER Stress-Inducing WFS1 Mutations Underlie a Genetic Syndrome of Neonatal/Infancy-Onset Diabetes, Congenital Sensorineural Deafness, and Congenital Cataracts.

    Science.gov (United States)

    De Franco, Elisa; Flanagan, Sarah E; Yagi, Takuya; Abreu, Damien; Mahadevan, Jana; Johnson, Matthew B; Jones, Garan; Acosta, Fernanda; Mulaudzi, Mphele; Lek, Ngee; Oh, Vera; Petz, Oliver; Caswell, Richard; Ellard, Sian; Urano, Fumihiko; Hattersley, Andrew T

    2017-07-01

    Neonatal diabetes is frequently part of a complex syndrome with extrapancreatic features: 18 genes causing syndromic neonatal diabetes have been identified to date. There are still patients with neonatal diabetes who have novel genetic syndromes. We performed exome sequencing in a patient and his unrelated, unaffected parents to identify the genetic etiology of a syndrome characterized by neonatal diabetes, sensorineural deafness, and congenital cataracts. Further testing was performed in 311 patients with diabetes diagnosed before 1 year of age in whom all known genetic causes had been excluded. We identified 5 patients, including the initial case, with three heterozygous missense mutations in WFS1 (4/5 confirmed de novo). They had diabetes diagnosed before 12 months (2 before 6 months) (5/5), sensorineural deafness diagnosed soon after birth (5/5), congenital cataracts (4/5), and hypotonia (4/5). In vitro studies showed that these WFS1 mutations are functionally different from the known recessive Wolfram syndrome-causing mutations, as they tend to aggregate and induce robust endoplasmic reticulum stress. Our results establish specific dominant WFS1 mutations as a cause of a novel syndrome including neonatal/infancy-onset diabetes, congenital cataracts, and sensorineural deafness. This syndrome has a discrete pathophysiology and differs genetically and clinically from recessive Wolfram syndrome. © 2017 by the American Diabetes Association.

  6. Anti-inflammatory effect of unsaturated fatty acids and Ergosta-7,22-dien-3-ol from Marthasterias glacialis: prevention of CHOP-mediated ER-stress and NF-κB activation.

    Directory of Open Access Journals (Sweden)

    David M Pereira

    Full Text Available There has been increasing awareness to the potential interest of drug discovery from marine natural products to treat several pathological conditions, including inflammation. In this work we describe the anti-inflammatory activity of several compounds present in the echinoderm Marthasterias glacialis (spiny sea-star, using the inflammatory model RAW 264.7 cells challenged with LPS. Lipidomic profiling of the organism revealed two major classes of compounds: fatty acids and sterols. Among these, the predominant compounds cis 11-eicosenoic and cis 11,14 eicosadienoic acids and the unsaturated sterol ergosta-7,22-dien-3-ol were evaluated. The mechanism of action of the compounds was distinct as they modulated different levels of the inflammation pathway. Classical inflammatory markers, such as COX-2, iNOS, IL-6 and NF-κB, were evaluated. We also studied the contribution of the CHOP pathway-mediated ER-stress to the inflammatory process. Overall, the sterol ergosta-7,22-dien-3-ol was the most active compound, however maximum activity was obtained when all compounds were tested in combination, thus suggesting a potentially synergistic activity of both classes of metabolites. This work establishes the echinoderm M. glacialis as an interesting source of anti-inflammatory molecules.

  7. Bifunctional role of ephrin A1-Eph system in stimulating cell proliferation and protecting cells from cell death through the attenuation of ER stress and inflammatory responses in bovine mammary epithelial cells.

    Science.gov (United States)

    Kang, Minkyung; Jeong, Wooyoung; Bae, Hyocheol; Lim, Whasun; Bazer, Fuller W; Song, Gwonhwa

    2018-03-01

    Structural and functional development of the mammary gland is constant in the mammary gland life cycle. Eph receptors and their ligands, ephrins, control events through cell-to-cell interactions during embryonic development, and adult tissue homeostasis; however, little information on participation of ephrin A1, a representative ligand of the Eph receptor, in the development and function of normal mammary glands is known. In this study, we demonstrated functional effects of the ephrin A1-Eph system and mechanisms of its action on bovine mammary epithelial (MAC-T) cells. The in vitro cultured MAC-T cells expressed the ephrin A1 ligand and EphA1, A2, A4, A7, and A8 among the eight members of the Eph A family. Our results revealed that ephrin A1 induced MAC-T cell cycle progression and stimulated cell proliferation with abundant expression of nucleic PCNA and cyclin D1 proteins. Additionally, ephrin A1 induced activation of intracellular signaling molecules involved in PI3 K/AKT and MAPK signaling, and the proliferation-stimulating effect of ephrin A1 was mediated by activation of these pathways. Furthermore, ephrin A1 influenced expression and activation of various ER stress-related proteins and protected MAC-T cells from stress-induced cell death. Finally, ephrin A1 alleviated LPS-induced cell death through down-regulation of inflammatory cytokines. In conclusion, the results of this study suggest that the Eph A-ephrin A1 system is a positive factor in the increase and maintenance of epithelial cells in mammary glands of cows; the signaling system contributes to development, remodeling, and functionality of normal mammary glands and could overcome mastitis in cows and other mammals. © 2017 Wiley Periodicals, Inc.

  8. Translational control of human acetyl-CoA carboxylase 1 mRNA is mediated by an internal ribosome entry site in response to ER stress, serum deprivation or hypoxia mimetic CoCl2.

    Science.gov (United States)

    Damiano, Fabrizio; Testini, Mariangela; Tocci, Romina; Gnoni, Gabriele V; Siculella, Luisa

    2018-01-14

    Acetyl-CoA carboxylase 1 (ACC1) is a cytosolic enzyme catalyzing the rate limiting step in de novo fatty acid biosynthesis. There is mounting evidence showing that ACC1 is susceptible to dysregulation and that it is over-expressed in liver diseases associated with lipid accumulation and in several cancers. In the present study, ACC1 regulation at the translational level is reported. Using several experimental approaches, the presence of an internal ribosome entry site (IRES) has been established in the 5' untranslated region (5' UTR) of the ACC1 mRNA. Transfection experiments with the ACC1 5' UTR inserted in a dicistronic reporter vector show a remarkable increase in the downstream cistron translation, through a cap-independent mechanism. The endoplasmic reticulum (ER) stress condition and the related unfolded protein response (UPR), triggered by treatment with thapsigargin and tunicamycin, cause an increase of the cap-independent translation of ACC1 mRNA in HepG2 cells, despite the overall reduction in global protein synthesis. Other stress conditions, such as serum starvation and incubation with hypoxia mimetic agent CoCl2, up-regulate ACC1 expression in HepG2 cells at the translational level. Overall, these findings indicate that the presence of an IRES in the ACC1 5' UTR allows ACC1 mRNA translation in conditions that are inhibitory to cap-dependent translation. A potential involvement of the cap-independent translation of ACC1 in several pathologies, such as obesity and cancer, has been discussed. Copyright © 2018. Published by Elsevier B.V.

  9. A small molecule inhibitor of NFκB blocks ER stress and the NLRP3 inflammasome and prevents progression of pancreatitis.

    Science.gov (United States)

    Kanak, Mazhar A; Shahbazov, Rauf; Yoshimatsu, Gumpei; Levy, Marlon F; Lawrence, Michael C; Naziruddin, Bashoo

    2017-03-01

    The underlying molecular mechanism that leads to development of chronic pancreatitis remains elusive. The aim of this study is to understand the downstream inflammatory signaling involved in progression of chronic pancreatitis, and to use withaferin A (WA), a small molecule inhibitor of nuclear factor κB (NFκB), to prevent progression of chronic pancreatitis. Two different protocols were used to induce pancreatitis in mice: standard and stringent administration of cerulein. The severity of pancreatitis was assessed by means of pancreatic histology and serum amylase levels. Immunohistochemistry and flow-cytometric analysis was performed to visualize immune cell infiltration into the pancreas. Real-time PCR and Western blot were used to analyze the downstream signaling mechanism involved in the development of chronic pancreatitis. The severity of cerulein-induced pancreatitis was reduced significantly by WA, used as either preventive or curative treatment. Immune cell infiltration into the pancreas and acinar cell death were efficiently reduced by WA treatment. Expression of proinflammatory and proapoptotic genes regulated by NFκB activation was increased by cerulein treatment, and WA suppressed these genes significantly. Sustained endoplasmic reticulum stress activation by cerulein administration was reduced. NLRP3 inflammasome activation in cerulein-induced pancreatitis was identified, and this was also potently blocked by WA. The human pancreatitis tissue gene signature correlated with the mouse model. Our data provide evidence for the role of NFκB in the pathogenesis of chronic pancreatitis, and strongly suggest that WA could be used as a potential therapeutic drug to alleviate some forms of chronic pancreatitis.

  10. Ondskaben er fortryllende

    DEFF Research Database (Denmark)

    Schubart, Rikke

    2013-01-01

    Indlæg om tv-serien Once Upon a Time (2011-), der hører til genren fairytale fantasy, der blander eventyr og fantasy. Her bliver alle eventyr brugt i en fortælling om alle beboere i en lille by, der ikke ved, at de i virkeligheden er eventyr-karakterer....

  11. Riget - alt er tilladt

    DEFF Research Database (Denmark)

    Agger, Gunhild

    2017-01-01

    Riget indtager en nøglestilling, når overgangen mellem faser i Triers produktion skal karakteriseres. Riget danner bro mellem den billedfascination og de radikale stileksperimenter, der præger Triers tidlige produktion, og den genre- og plotbevidsthed, der er typisk for film som Breaking the Wave...... (1996) og Dancer in the Dark (2000). Artiklen analyserer hvordan....

  12. It er godt - basta!

    DEFF Research Database (Denmark)

    Bundsgaard, Jeppe

    2012-01-01

    Der er offentlig konsensus om at it i undervisningen fører til øget faglighed. Men it kan lige så godt resultere i ringere undervisning som i bedre - og ofte anvendes it helt traditionelt og fantasiløst....

  13. Hvad er tidligt sprog

    DEFF Research Database (Denmark)

    Skriver Jensen, Anders

    2009-01-01

    Forfatteren argumenterer for at "early literacy" kan oversættes til "tidligt sprog"; særligt når der er tale om en helhedsorienteret tilgang med vægt på sprog som et alsidigt medie for kommunikation- og betydningsskabelse. Med inspiration fra Jerome Bruners kulturpsykologi diskuteres mulige...

  14. Litteratur er nyttig

    DEFF Research Database (Denmark)

    Kaspersen, Peter

    2012-01-01

    Den anmeldte bog er en forskningsbaseret debatbog om hvilken nytteværdi litteratur har. Bogen placeres i sammenhæng med en række bøger på nordiske sprog og engelsk om litteraturens, litteraturundervisningens og -forskningens legitimitet. Argumentatioen i bogen bygger på Bakhtins litteratursyn, og...

  15. Ideologi er noget bras

    DEFF Research Database (Denmark)

    Hansen, Brian Benjamin; Jøker Bjerre, Henrik

    fra den slovenske filosof Slavoj Zizek stilles imidlertid det spørgsmål i bogen, om ideologien idag ikke blot har taget en anden form. Vi lever i dag ikke i post-ideologiske tider. Snarere er braset selv – X Factor, forbrugsobjekter, underholdning, følelser og balloner – blevet den næsten usynlige...

  16. er 1999

    DEFF Research Database (Denmark)

    Jensen, J. P.; Søndergaard, M.; Jeppesen, E.

    land bidrager med flest næringsstoffer til søerne Stoftilførslen af såvel fosfor som kvælstof til søerne har i 1999 som tidligere år været domineret af tilførslen fra det åbne land, der gen-nemsnitligt har bidraget med ca. 73 % af fosfortilførslen og ca. 78 % af kvælstoftilførslen (Fig. 0...... for de mest belastede søer. Således er både fosfor- og kvælstof-bidraget fra byspildevand og industrispildevand fra 1989 til 1999 reduceret meget markant fra ca. 22 % til ca. 3 %. Figur 0.1 Kildefordeling for fosfor- og kvælsstoftilførslen til søerne i 1999. Grå: Åbent land (landbrug + baggrund). Sort...... af overvågningssøerne, efter at søer-ne er blevet klarvandede som følge af ændringer i fiskebestanden. I halvdelen af søerne var kvælstof-tilbageholdelsen i 1999 højere end 26 %. Medianen og gennemsnittet for den absolutte kvælstoftilbagehol-delse var 93 og 111 mg N m-2 dag-1 svarende til 340 og 405...

  17. Hvad er alternativet?

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    2015-01-01

    Anmeldelsen af Mårtenssons "Konkurrencestatens pædagogik" præsenterer dels forfatterens kritik af og alternativ til den igangværende reform af folkeskolen, dels advarer den mod at forfalde til konspirationsteori. Endelig peger den på, at Mårtenssons såkaldte alternativ er gammel vin på nye flaske...

  18. Patienten - hvor er patienten?

    DEFF Research Database (Denmark)

    Nielsen, Gitte; Dau, Susanne

    2011-01-01

    på, hvad der historisk og nutidigt karakteriserer teori og praksis, samt forholdet herimellem. I den empiriske del er der, med udgangspunkt i Gadamers hermeneutiske tilgang, foretaget tre kvalitative forkusgruppeinterview. Ét af sygeplejestuderende, ét af kliniske vejledere og ét af undervisere...

  19. Er danskerne racister?

    DEFF Research Database (Denmark)

    Necef, Mehmet Ümit; Bech, Henning

    Igennem de seneste årtier er det blevet almindeligt at tale om, at der er en udbredt racisme i Danmark. Påstande om danskernes racisme, fremmedhad og diskrimination optræder dagligt i offentligheden og i medierne, og der henvises ofte til, hvad ’forskerne’ og de ’videnskabelige undersøgelser’ siger...... om emnet. Der kan da næppe heller være tvivl om, at der forekommer racistiske holdninger hos nogle danskere. Men er problemet så stort, som det gøres til i den offentlige debat? Bogen ønsker at afklare, hvorvidt der er videnskabelig dokumentation for påstandene om danskernes racisme. Den går i dybden...... med en række forskeres og eksperters udtalelser på området og præsenterer en grundig analyse af deres fremstilling af dansk racisme i forhold til emner som kultur, seksualitet, kriminalitet og arbejdsmarked....

  20. Nordslesvigeren er nr. 1

    DEFF Research Database (Denmark)

    Christensen, Steffen Lind

    2015-01-01

    Historien om de nordslesvigske krigsdeltagere under 1. Verdenskrig er traditionelt blevet behandlet i et nationalt perspektiv. Her benævnes soldaterne oftest som ’danske’. Denne artikel undersøger, hvordan nordslesvigske soldater på Østfronten selv udtrykte deres identitet i krigssituationen...

  1. Ltc1 is an ER-localized sterol transporter and a component of ER-mitochondria and ER-vacuole contacts.

    Science.gov (United States)

    Murley, Andrew; Sarsam, Reta D; Toulmay, Alexandre; Yamada, Justin; Prinz, William A; Nunnari, Jodi

    2015-05-25

    Organelle contact sites perform fundamental functions in cells, including lipid and ion homeostasis, membrane dynamics, and signaling. Using a forward proteomics approach in yeast, we identified new ER-mitochondria and ER-vacuole contacts specified by an uncharacterized protein, Ylr072w. Ylr072w is a conserved protein with GRAM and VASt domains that selectively transports sterols and is thus termed Ltc1, for Lipid transfer at contact site 1. Ltc1 localized to ER-mitochondria and ER-vacuole contacts via the mitochondrial import receptors Tom70/71 and the vacuolar protein Vac8, respectively. At mitochondria, Ltc1 was required for cell viability in the absence of Mdm34, a subunit of the ER-mitochondria encounter structure. At vacuoles, Ltc1 was required for sterol-enriched membrane domain formation in response to stress. Increasing the proportion of Ltc1 at vacuoles was sufficient to induce sterol-enriched vacuolar domains without stress. Thus, our data support a model in which Ltc1 is a sterol-dependent regulator of organelle and cellular homeostasis via its dual localization to ER-mitochondria and ER-vacuole contact sites. © 2015 Murley et al.

  2. The endoplasmic reticulum stress/unfolded protein response in gliomagenesis, tumor progression and as a therapeutic target in glioblastoma

    NARCIS (Netherlands)

    Peñaranda Fajardo, Natalia; Meijer, Coby; Kruyt, Frank A. E.

    2016-01-01

    Endoplasmic reticulum (ER) stress disrupts among others protein homeostasis in cells leading to the activation of the unfolded protein response (UPR) that is crucial for restoring this balance and cell survival. Hypoxia, reactive oxygen species and nutrient deprivation, conditions commonly present

  3. Selected terpenoids from medicinal plants modulate endoplasmic reticulum stress in metabolic disorders.

    Science.gov (United States)

    Beukes, Natasha; Levendal, Ruby-Ann; Frost, Carminita L

    2014-11-01

    The majority of research performed on cellular stress and apoptosis focuses on mitochondrial dysfunction; however, the importance of the endoplasmic reticulum dysfunction and the link to metabolic diseases has gained a substantial interest. This review focuses on the potential of terpenoids to influence endoplasmic reticulum stress and the possible role terpenoids play as the treatment of metabolic diseases. Metabolic diseases develop as a result of a cascade of cellular pathways. In most cases, cells are able to compensate for the disruption of the cellular homeostasis although the initiation of response pathways; however, chronic stress initiates apoptotic pathways. This reviewed (1) showed the importance of phytoterpenoids to influence endoplasmic reticulum (ER) stress and homeostasis, (2) showed how regulating ER stress affect the cell survival and death, and (3) highlighted some examples of how the progression of metabolic diseases can be influenced by ER. Due to the substantial number of terpenoids that have been identified in literature, this review gave examples of 21 terpenoids that have been documented to have an effect on the different proteins associated with ER stress, how these plant terpenoids influence ER dysfunction and metabolic diseases such as diabetes, cancer, liver, and neurological diseases and parasitic infections. © 2014 Royal Pharmaceutical Society.

  4. Flow cytometric assessment of the protectants for enhanced in vitro survival of probiotic lactic acid bacteria through simulated human gastro-intestinal stresses.

    Science.gov (United States)

    Chen, Song; Cao, Yu; Ferguson, Lynnette R; Shu, Quan; Garg, Sanjay

    2012-07-01

    The aim of this study was to apply flow cytometric (FCM) analysis to assess the use of sucrose and lecithin vesicles for the protection of probiotic lactic acid bacteria in response to the challenge of gastric acidity and bile salts. FCM analysis in combination with fluorescent probes carboxyfluorescein (cF) and propidium iodide was used to reveal the physiological heterogeneity in the stressed bacteria population. Three subpopulations (intact, stressed, and damaged) were differentiated by FCM in all six examined strains. Significant changes were observed in the presence of the selected protectants. The addition of 20 mM sucrose in the simulated gastric fluid substantially increased the number of intact cells over 20 folds and reduced the damaged subpopulation by half. The presence of 2 % (w/v) lecithin vesicles was shown to protect 50 % more intact cells from the challenge of bile salts. The improved survival as evaluated by FCM analysis was further assessed for the proliferation capacity by sorting a number of cells from each subpopulation on nutrient agar plate. The result confirmed conformity between the proliferation-based cultivability and the probe-indicated viability in the samples of the intact and the damaged subpopulations. However, it also revealed the complexities of the stressed (injured) subpopulation. In conclusion, FCM analysis confirmed that the selected protectants could improve the survival of the probiotic strains in the simulated GI environments. The FCM analysis also proved to be a useful analytical tool for the probiotics research.

  5. Stress

    Science.gov (United States)

    ... natural disaster. This type of stress can cause post-traumatic stress disorder (PTSD). Different people may feel stress in different ways. Some people experience digestive symptoms. Others may have headaches, sleeplessness, depressed mood, anger, ...

  6. Effect of oxygen stress on growth and survival of Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes under different storage conditions.

    Science.gov (United States)

    Al-Qadiri, Hamzah; Sablani, Shyam S; Ovissipour, Mahmoudreza; Al-Alami, Nivin; Govindan, Byju; Rasco, Barbara

    2015-04-01

    This study investigated the growth and survival of three foodborne pathogens (Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes) in beef (7% fat) and nutrient broth under different oxygen levels. Samples were tested under anoxic (perfringens could grow in beef at 22 °C, with an increase of approximately 5 log under anoxic conditions and a 1-log increase under microoxic conditions. However, C. perfringens could not survive in beef held at 7 °C under microoxic and oxic storage conditions after 14 days. In an anoxic environment, C. perfringens survived in beef samples held at 7 °C, with a 1-log reduction. A cell decline was observed at 2 log under these conditions, with no surviving cells at the 1-log level. However, the results show that C. jejuni under microoxic conditions survived with declining cell numbers. Significant increases in L. monocytogenes (5 to 7 log) were observed in beef held at 22 °C for 5 days, with the lowest levels recovered under anoxic conditions. L. monocytogenes in refrigerated storage increased by a factor of 2 to 4 log. It showed the greatest growth under oxic conditions, with significant growth under anoxic conditions. These findings can be used to enhance food safety in vacuum-packed and modified atmosphere-packaged food products.

  7. Fluidised-bed spray-drying formulations of Candida sake CPA-1 by adding biodegradable coatings to enhance their survival under stress conditions.

    Science.gov (United States)

    Carbó, Anna; Torres, Rosario; Usall, Josep; Solsona, Cristina; Teixidó, Neus

    2017-11-01

    The biocontrol agent Candida sake CPA-1 has demonstrated to be effective against several diseases on fruit. However, for application of CPA-1 under field conditions, it was necessary to mix it with a food coating to improve survival under stress conditions, as well as adherence and distribution on fruit surfaces. The objective of this study was to obtain a more competitive formulation under field conditions to be applied independently of any product. To achieve this purpose, the drying process of CPA-1 by a fluidised-bed spray-drying system together with biodegradable coatings was optimised. This approach is novel for the drying system used and the formulation obtained which was able to form a film or coating on fruit surfaces. Several substances were tested as carriers and binders, and drying temperature was optimised. The addition of protective compounds was also tested to improve survival of CPA-1 during the dehydration process. Product shelf life, biocontrol efficacy on grapes against Botrytis cinerea, and the improvement of C. sake behaviour under stress conditions were tested. The optimal temperature of drying was 55 °C and two formulations that were able to develop a coating on fruit surfaces were obtained. One of the formulations was created by using a combination of native and pregelatinised potato starch; the other formulation was obtained using maltodextrin and by adding skimmed milk and sucrose as protectant compounds. The formulated products reduced the incidence and severity of B. cinerea, and CPA-1 survival rate was increased under stress conditions of temperature and humidity.

  8. Aquaporins-2 and -4 regulate glycogen metabolism and survival during hyposmotic-anoxic stress in Caenorhabditis elegans.

    Science.gov (United States)

    LaMacchia, John C; Roth, Mark B

    2015-07-15

    Periods of oxygen deprivation can lead to ion and water imbalances in affected tissues that manifest as swelling (edema). Although oxygen deprivation-induced edema is a major contributor to injury in clinical ischemic diseases such as heart attack and stroke, the pathophysiology of this process is incompletely understood. In the present study we investigate the impact of aquaporin-mediated water transport on survival in a Caenorhabditis elegans model of edema formation during complete oxygen deprivation (anoxia). We find that nematodes lacking aquaporin water channels in tissues that interface with the surrounding environment display decreased edema formation and improved survival rates in anoxia. We also find that these animals have significantly reduced demand for glycogen as an energetic substrate during anoxia. Together, our data suggest that reductions in membrane water permeability may be sufficient to induce a hypometabolic state during oxygen deprivation that reduces injury and extends survival limits. Copyright © 2015 the American Physiological Society.

  9. Determine the Influence of Time Held in “Knockdown” Anesthesia on Survival and Stress of Surgically Implanted Juvenile Salmonids

    Energy Technology Data Exchange (ETDEWEB)

    Woodley, Christa M.; Wagner, Katie A.; Knox, Kasey M.

    2012-01-31

    The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed for the U.S. Army Corp of Engineers Portland District (USACE) to address questions related to survival and performance measures of juvenile salmonids as they pass through the Federal Columbia River Power System (FCRPS). Researchers using JSATS acoustic transmitters (ATs) were tasked with standardizing the surgical implantation procedure to ensure that the stressors of handling and surgery on salmonids were consistent and less likely to cause effects of tagging in survival studies. Researchers questioned whether the exposure time in 'knockdown' anesthesia (or induction) to prepare fish for surgery could influence the survival of study fish (CBSPSC 2011). Currently, fish are held in knockdown anesthesia after they reach Stage 4 anesthesia until the completion of the surgical implantation of a transmitter, varies from 5 to 15 minutes for studies conducted in the Columbia Basin. The Columbia Basin Surgical Protocol Steering Committee (CBSPSC ) expressed concern that its currently recommended 10-minute maximum time limit during which fish are held in anesthetic - tricaine methanesulfonate (MS-222, 80 mg L-1 water) - could increase behavioral and physiological costs, and/or decrease survival of outmigrating juvenile salmonids. In addition, the variability in the time fish are held at Stage 4 could affect the data intended for direct comparison of fish within or among survival studies. Under the current recommended protocol, if fish exceed the 10-minute time limit, they are to be released without surgical implantation, thereby increasing the number of fish handled and endangered species 'take' at the bypass systems for FCRPS survival studies.

  10. Er HR ude i tovene?

    DEFF Research Database (Denmark)

    Poulfelt, Flemming

    2015-01-01

    HR: Er der behov for nytænkning i HR-land? Artikler i Harvard Business Review - bakket op af en dansk undersøgelse - konkluderer, at HR stadig mangler gennemslagskraft i virksomhederne. Er HR ude i tovene? ... For i undersøgelsen "Ny Dansk Ledelse" (maj 2015), som er baseret på danske lederes...

  11. Facebook er internettet nu

    DEFF Research Database (Denmark)

    Tække, Jesper

    2014-01-01

    Den store vision for world wide web var, at alle kunne få ubegrænset adgang til alverdens information. www var mangfoldigt og anarkistisk. I dag er der rigtig mange, der kun bruger nettet til at være på Facebook. Hvad bruger Facebook det til? Og hvad gør det ved vores udsyn?......Den store vision for world wide web var, at alle kunne få ubegrænset adgang til alverdens information. www var mangfoldigt og anarkistisk. I dag er der rigtig mange, der kun bruger nettet til at være på Facebook. Hvad bruger Facebook det til? Og hvad gør det ved vores udsyn?...

  12. Effects of release procedures on the primary stress response and post-release survival and growth of hatchery-reared spotted seatrout Cynoscion nebulosus.

    Science.gov (United States)

    Guest, T W; Rakocinski, C F; Evans, A N; Blaylock, R B

    2017-03-01

    To help explain the apparent poor post-release success of hatchery-reared (HR) spotted seatrout Cynoscion nebulosus, this study examined the effects of handling, transport and release procedures on the stress response of two age classes [48 and 80 day post-hatch (dph)] of HR C. nebulosus, as measured by cortisol concentrations and the post-release survival and growth of 48 and 80 dph HR C. nebulosus. As a proxy for stress, tissue cortisol was measured at various times during the handling, tagging (80 dph), transport, acclimation and release process. To consider the implications of the pre-release stressors, growth and survival were monitored in separate field experiments for each age class of acclimated post-transport C. nebulosus using control C. nebulosus that only experienced anaesthesia, transport, acclimation and a net release v. experimental C. nebulosus that underwent the entire routine procedure, including anaesthesia, tagging, transport, acclimation and gravity release through a pipe. For 48 dph C. nebulosus, mean cortisol varied significantly throughout handling and transport, increasing more than six-fold from controls before decreasing in mean concentration just prior to release. For 80 dph C. nebulosus, cortisol varied throughout handling, tagging and transport, first increasing more than three-fold compared with control C. nebulosus, before decreasing and rising slightly just prior to release. For 48 dph C. nebulosus within field enclosures, survival was high and similar for control and experimental groups; experimental C. nebulosus, however, were shorter, lighter and lower in condition than control C. nebulosus. For 80 dph C. nebulosus within field enclosures, fewer experimental C. nebulosus survived and those that did survive were of lower condition than C. nebulosus from the control group. Small untagged C. nebulosus may survive the release procedure better than larger C. nebulosus carrying a coded-wire tag. These findings document

  13. Hvad er en by?

    DEFF Research Database (Denmark)

    Parby, Jakob; Thelle, Mikkel

    2011-01-01

    Nytænkning. Med de moderne megabyer er det slut med at forestille sig byen som noget, man planlægger og giver form. Vi skal lære at se dem som vildtvoksende urbane landskaber. Artikel om megabyer, byudvikling og forestillingen om byen gennem tiderne. Skrevet delvist i anledning af åbningen af...... udstillingen Citambulos på Københavns Museum, der handlede om Mexico City....

  14. Hvis er Himmeriget?

    DEFF Research Database (Denmark)

    Holst, Søren

    2007-01-01

    Udtrykket "de fattige i ånden", som kendes fra Bjergprædikenen i Matthæusevangeliet, forekommer også i to af Dødehavsrullerne. Artiklen undersøger disse tekster og argumenterer for, at udtrykket ikke betegner en særligt "åndelig" fattigdom, men derimod de konkret økonomisk fattige, som er "af ånd...

  15. er 2000

    DEFF Research Database (Denmark)

    Jensen, J. P.; Søndergaard, M.; Jeppesen, E.

    ændringer i be-lastningen af vand-miljøet med nærings-salte. Med NOVA er programmet udvidet til at omfatte både vand-miljøets tilstand i bredeste forstand og miljøfremmede stoffer og tungmetaller. Danmarks Miljøundersø-gelser har som sektor-forskningsinstitu-tion i Miljøministeriet til opgave at forbedre og...

  16. Han er her endnu

    DEFF Research Database (Denmark)

    Bonde, Lisbeth

    2012-01-01

    Interview med den kinesiske aktivist og billedkunstner Ai Weiwei, der sad fængslet i 81 dage i 2011. Hans pas er stadig (i februar 2014) inddraget af myndighederne, så han kan ikke forlade landet, selv om han har betalt en bøde på 13 mio. kr. for ”skatteunddragelse”. Både i sin kunst og i sine ma...

  17. Survival of Enterococcus faecalis during alkaline stress: changes in morphology, ultrastructure, physiochemical properties of the cell wall and specific gene transcripts.

    Science.gov (United States)

    Ran, Shujun; He, Zhiyan; Liang, Jingping

    2013-11-01

    The aim of this investigation was to study the biochemical mechanisms employed by the endodontic pathogen Enterococcus faecalis to survive alkaline environment during biofilm formation. E. faecalis ATCC33186 was inoculated in media at pH 7, 9, 10 and 11 for biofilm formation. The morphology and ultrastructure of biofilm cells were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The physiochemical properties of the cell wall were investigated by measuring the hydrophobicity and Na(+)K(+)-ATPase and H(+)K(+)-ATPase activity. The expression of stress and virulence genes was quantified by real-time quantitative polymerase chain reaction. E. faecalis grown in alkaline medium developed an irregular shape and asymmetrical septation. The activity of Na(+)K(+)-ATPase increased dramatically with rising pH, whereas the activity of H(+)K(+)-ATPase exhibited no increase, except at pH 10. A marked increase in cell surface hydrophobicity was also observed with increased pH and time. In addition, transcription of most of the genes tested increased 2- to 15-fold at pH 9 or 10 compared with pH 7 and increased more than 50-fold at pH 11, which is generally recognised as nearly lethal stress. E. faecalis survival and biofilm formation under alkaline stress was unrelated to H(+)K(+)-ATPase but was correlated with an increase in Na(+)K(+)-ATPase activity and cell-surface hydrophobicity in addition to the up-regulation of genes involved in stress response and biofilm formation. These characteristics may explain why E. faecalis resists alkaline root canal medications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. A Molecular Web: Endoplasmic Reticulum Stress, Inflammation, and Oxidative Stress

    Science.gov (United States)

    Chaudhari, Namrata; Talwar, Priti; Parimisetty, Avinash; Lefebvre d’Hellencourt, Christian; Ravanan, Palaniyandi

    2014-01-01

    Execution of fundamental cellular functions demands regulated protein folding homeostasis. Endoplasmic reticulum (ER) is an active organelle existing to implement this function by folding and modifying secretory and membrane proteins. Loss of protein folding homeostasis is central to various diseases and budding evidences suggest ER stress as being a major contributor in the development or pathology of a diseased state besides other cellular stresses. The trigger for diseases may be diverse but, inflammation and/or ER stress may be basic mechanisms increasing the severity or complicating the condition of the disease. Chronic ER stress and activation of the unfolded-protein response (UPR) through endogenous or exogenous insults may result in impaired calcium and redox homeostasis, oxidative stress via protein overload thereby also influencing vital mitochondrial functions. Calcium released from the ER augments the production of mitochondrial Reactive Oxygen Species (ROS). Toxic accumulation of ROS within ER and mitochondria disturbs fundamental organelle functions. Sustained ER stress is known to potentially elicit inflammatory responses via UPR pathways. Additionally, ROS generated through inflammation or mitochondrial dysfunction could accelerate ER malfunction. Dysfunctional UPR pathways have been associated with a wide range of diseases including several neurodegenerative diseases, stroke, metabolic disorders, cancer, inflammatory disease, diabetes mellitus, cardiovascular disease, and others. In this review, we have discussed the UPR signaling pathways, and networking between ER stress-induced inflammatory pathways, oxidative stress, and mitochondrial signaling events, which further induce or exacerbate ER stress. PMID:25120434

  19. Prodigiosin activates endoplasmic reticulum stress cell death pathway in human breast carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Mu-Yun [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Yuh-Chiang [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); National Research Institute of Chinese Medicine, Taipei, Taiwan (China); Lu, Chien-Hsing [Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Yang, Shu-Yi [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Ho, Tsing-Fen [Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Peng, Yu-Ta [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China)

    2012-12-15

    Prodigiosin is a bacterial tripyrrole pigment with potent cytotoxicity against diverse human cancer cell lines. Endoplasmic reticulum (ER) stress is initiated by accumulation of unfolded or misfolded proteins in the ER lumen and may induce cell death when irremediable. In this study, the role of ER stress in prodigiosin-induced cytotoxicity was elucidated for the first time. Comparable to the ER stress inducer thapsigargin, prodigiosin up-regulated signature ER stress markers GRP78 and CHOP in addition to activating the IRE1, PERK and ATF6 branches of the unfolded protein response (UPR) in multiple human breast carcinoma cell lines, confirming prodigiosin as an ER stress inducer. Prodigiosin transcriptionally up-regulated CHOP, as evidenced by its promoting effect on the CHOP promoter activity. Of note, knockdown of CHOP effectively lowered prodigiosin's capacity to evoke PARP cleavage, reduce cell viability and suppress colony formation, highlighting an essential role of CHOP in prodigiosin-induced cytotoxic ER stress response. In addition, prodigiosin down-regulated BCL2 in a CHOP-dependent manner. Importantly, restoration of BCL2 expression blocked prodigiosin-induced PARP cleavage and greatly enhanced the survival of prodigiosin-treated cells, suggesting that CHOP-dependent BCL2 suppression mediates prodigiosin-elicited cell death. Moreover, pharmacological inhibition of JNK by SP600125 or dominant-negative blockade of PERK-mediated eIF2α phosphorylation impaired prodigiosin-induced CHOP up-regulation and PARP cleavage. Collectively, these results identified ER stress-mediated cell death as a mode-of-action of prodigiosin's tumoricidal effect. Mechanistically, prodigiosin engages the IRE1–JNK and PERK–eIF2α branches of the UPR signaling to up-regulate CHOP, which in turn mediates BCL2 suppression to induce cell death. Highlights: ► Prodigiosin is a bacterial tripyrrole pigment with potent anticancer effect. ► Prodigiosin is herein identified

  20. TeknoStress

    DEFF Research Database (Denmark)

    Thygesen, Niels Thyge

    2017-01-01

    Denne artikel handler om hvordan målstyring skaber stress. Normalt tænker vi på målstyring og andre ledelsesteknologier, som neutrale instrumenter og som i sig selv ikke er harmfulde. Men hvad hvis ledelsesteknologier slet ikke er neutrale og harmløse? Og hvad hvis kimen til stress blandt andet...

  1. Naltrexone ER/Bupropion ER: A Review in Obesity Management.

    Science.gov (United States)

    Greig, Sarah L; Keating, Gillian M

    2015-07-01

    Oral naltrexone extended-release/bupropion extended-release (naltrexone ER/bupropion ER; Contrave(®), Mysimba(™)) is available as an adjunct to a reduced-calorie diet and increased physical activity in adults with an initial body mass index (BMI) of ≥ 30 kg/m(2) (i.e. obese) or a BMI of ≥ 27 kg/m(2) (i.e. overweight) in the presence of at least one bodyweight-related comorbidity, such as type 2 diabetes mellitus, hypertension or dyslipidaemia. In 56-week phase III trials in these patient populations, oral naltrexone ER/bupropion ER 32/360 mg/day was significantly more effective than placebo with regard to percentage bodyweight reductions from baseline and the proportion of patients who achieved bodyweight reductions of ≥ 5 and ≥ 10%. Significantly greater improvements in several cardiometabolic risk factors were also observed with naltrexone ER/bupropion ER versus placebo, as well as greater improvements in glycated haemoglobin levels in obese or overweight adults with type 2 diabetes. Naltrexone ER/bupropion ER was generally well tolerated in phase III trials, with nausea being the most common adverse event. Thus, naltrexone ER/bupropion ER 32/360 mg/day as an adjunct to a reduced-calorie diet and increased physical activity, is an effective and well tolerated option for chronic bodyweight management in obese adults or overweight adults with at least one bodyweight-related comorbidity.

  2. Exposure to extremely low frequency (50 Hz electromagnetic field changes the survival rate and morphometric characteristics of neurosecretory neurons of the earthworm Eisenia foetida (Oligochaeta under illumination stress

    Directory of Open Access Journals (Sweden)

    Banovački Zorana

    2013-01-01

    Full Text Available An in vivo model was set up to establish the behavioral stress response (rate of survival and morphometric characteristics of A1 protocerebral neurosecretory neurons (cell size of Eisenia foetida (Oligochaeta as a result of the synergetic effect of extremely low frequency electromagnetic fields (ELF-EMF - 50 Hz, 50 μT, 17 V/m and 50 Hz, 150 μT, 17 V/m, respectively and constant illumination (420-450 lux. If combined, these two stressors significantly (p<0.05 increased the survival rate of E. foetida in the 150 μT-exposed animals, because of delayed caudal autotomy reflex, an indicator of stress response. In addition, morphometric analysis indicated that there were changes in the protocerebral neurosecretory cells after exposure to the ELF-EMF. The present data support the view that short-term ELF-EMF exposure in “windows” of intensity is likely to stimulate the immune and neuroendocrine response of E. foetida.

  3. Involvement of Endoplasmic Reticulum Stress-Mediated C/EBP Homologous Protein Activation in Coxsackievirus B3-Induced Acute Viral Myocarditis.

    Science.gov (United States)

    Cai, Zhejun; Shen, Li; Ma, Hong; Yang, Jin; Yang, Du; Chen, Han; Wei, Jia; Lu, Qiulun; Wang, Dao Wen; Xiang, Meixiang; Wang, Jian'an

    2015-07-01

    This study tested the hypothesis whether endoplasmic reticulum (ER) stress/C/EBP homologous protein (CHOP) signaling is linked with coxsackievirus B3 (CVB3)-induced acute viral myocarditis (AVMC) in vivo. AVMC was induced by intraperitoneal injection of 1000 tissue culture infectious dose (TCID50) of CVB3 virus in mice. In AVMC mouse hearts (n=11), ER stress and CHOP were significantly activated, and were linked to the induction of proapoptotic signaling including reduction of Bcl-2, activation of Bax and caspase 3, compared with the controls (n=10), whereas these could be markedly blocked by ER stress inhibitor tauroursodeoxycholic acid administration (n=11). Moreover, chemical inhibition of ER stress significantly attenuated cardiomyocytes apoptosis, and prevented cardiac troponin I elevation, ameliorated cardiac dysfunction assessed by both hemodynamic and echocardiographic analysis, reduced viral replication, and increased survival rate after CVB3 inoculation. We further discovered that genetic ablation of CHOP (n=10) suppressed cardiac Bcl-2/Bax ratio reduction and caspase 3 activation, and prevented cardiomyotes apoptosis in vivo, compared with wild-type receiving CVB3 inoculation (n=10). Strikingly, CHOP deficiency exhibited dramatic protective effects on cardiac damage, cardiac dysfunction, viral replication, and promoted survival in CVB3-caused AVMC. Our data imply the involvement of ER stress/CHOP signaling in CVB3-induced AVMC via proapoptotic pathways, and provide a novel strategy for AVMC treatment. © 2015 American Heart Association, Inc.

  4. Endoplasmic Reticulum Stress and Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Kemal Ergin

    2015-04-01

    Full Text Available Endoplasmic reticulum (ER stress, which results from different stimuli, is an important cellular event. There are different types of response to ER stress. One of them is evolutionarily conserved unfolded protein response (UPR. UPR has three sensors for further activation of molecules. These sensors are inositol-requiring enzyme 1 (IRE1, activated transcription factor 6 (ATF6, and ER-resident protein kinase RNA (PKR-like ER kinase (PERK. In the absence of ER stress, these sensors are maintained in an inactive state. However, under ER stress conditions, they became activated and induce the downstream targets. As a consequence of ER stress, the cell may stay alive or became dead. Several studies have shown that ER stress is associated with different types of diseases such as diabetes mellitus, Alzheimer’s disease, prion disease, and cancer. As a cancer type, it has been shown that pancreatic cancer is also associated with ER stress. Pancreatic cancer has a low cure potential with its late diagnosis. Its association with ER stress is seen as a new therapeutic approach. The aim of this is review is to provide an overview of the mechanisms of ER stress and its relationship with pancreatic cancer, one of the diseases in which ER stress affects pathogenesis.

  5. Resilience potential of an Indian Ocean reef: an assessment through coral recruitment pattern and survivability of juvenile corals to recurrent stress events.

    Science.gov (United States)

    Manikandan, Balakrishnan; Ravindran, Jeyaraman; Vidya, Pottekkatt Jayabalan; Shrinivasu, Selvaraju; Manimurali, Rajagopal; Paramasivam, Kaliyaperumal

    2017-05-01

    Coral reefs are degraded by the synergistic action of climate and anthropogenic stressors. Coral cover in the Palk Bay reef at the northern Indian Ocean largely declined in the past decade due to frequent bleaching events, tsunami and increased fishing activities. In this study, we carried out a comparative assessment to assess the differences in the recovery and resilience of three spatially distant reefs viz. Vedhalai, Mandapam and Pamban along Palk Bay affected by moderate, severe and low fishing pressure respectively. The assessment was based on the juvenile coral recruitment pattern and its survivability combined with availability of hard substratum, live coral cover and herbivore reef fish stock. The Vedhalai reef has the highest coral cover (14.6 ± 6.3%), and ≥90% of the live corals in Vedhalai and Mandapam were affected by turf algal overgrowth. The density of herbivore reef fish was low in Vedhalai and Mandapam reefs compared to the Pamban reef with relatively few grazing species. The juvenile coral diversity and density were high in the Pamban reef and low in Vedhalai and Mandapam reefs despite high hard substratum cover. In total, 22 species of juvenile corals of 10 genera were recorded in Palk Bay. Comparison of the species diversity of juvenile corals with adult ones suggested that the Pamban reef is connected with other distant reefs whereas Vedhalai and Mandapam reefs were self-seeded. There was no statistically significant difference in the survivability of juvenile corals between the study sites, and in total, ≥90% of the juvenile corals survived the high sedimentation stress triggered by the northeast monsoon and bleaching stress that occurred recurrently. Our results indicated that the human activities indirectly affected the juvenile coral recruitment by degrading the live coral cover and contributed to the spatial variation in the recovery and resilience of the Palk Bay reef. Low species diversity of the juvenile corals will increase the

  6. Downregulation of miR-205 modulates cell susceptibility to oxidative and endoplasmic reticulum stresses in renal tubular cells.

    Directory of Open Access Journals (Sweden)

    Shiyo Muratsu-Ikeda

    Full Text Available BACKGROUND: Oxidative stress and endoplasmic reticulum (ER stress play a crucial role in tubular damage in both acute kidney injury (AKI and chronic kidney disease (CKD. While the pathophysiological contribution of microRNAs (miRNA to renal damage has also been highlighted, the effect of miRNA on renal damage under oxidative and ER stresses conditions remains elusive. METHODS: We assessed changes in miRNA expression in the cultured renal tubular cell line HK-2 under hypoxia-reoxygenation-induced oxidative stress or ER stress using miRNA microarray assay and real-time RT-PCR. The pathophysiological effect of miRNA was evaluated by cell survival rate, intracellular reactive oxygen species (ROS level, and anti-oxidant enzyme expression in miRNA-inhibited HK-2 or miRNA-overexpressed HK-2 under these stress conditions. The target gene of miRNA was identified by 3'-UTR-luciferase assay. RESULTS: We identified 8 and 10 miRNAs whose expression was significantly altered by oxidative and ER stresses, respectively. Among these, expression of miR-205 was markedly decreased in both stress conditions. Functional analysis revealed that decreased miR-205 led to an increase in cell susceptibility to oxidative and ER stresses, and that this increase was associated with the induction of intracellular ROS and suppression of anti-oxidant enzymes. While increased miR-205 by itself made no change in cell growth or morphology, cell viability under oxidative or ER stress conditions was partially restored. Further, miR-205 bound to the 3'-UTR of the prolyl hydroxylase 1 (PHD1/EGLN2 gene and suppressed the transcription level of EGLN2, which modulates both intracellular ROS level and ER stress state. CONCLUSIONS: miR-205 serves a protective role against both oxidative and ER stresses via the suppression of EGLN2 and subsequent decrease in intracellular ROS. miR-205 may represent a novel therapeutic target in AKI and CKD associated with oxidative or ER stress in tubules.

  7. Posttraumatic stress disorder (PTSD) in children after paediatric intensive care treatment compared to children who survived a major fire disaster

    NARCIS (Netherlands)

    Bronner, M.B.; Knoester, H.; Bos, AP; Last, B.F.; Grootenhuis, M.A.

    2008-01-01

    Background: The goals were to determine the presence of posttraumatic stress disorder (PTSD) in children after paediatric intensive care treatment, to identify risk factors for PTSD, and to compare this data with data from a major fire disaster in the Netherlands. Methods: Children completed the

  8. Crosstalk between endoplasmic reticulum stress, oxidative stress and autophagy: Potential therapeutic targets for acute CNS injuries

    Science.gov (United States)

    Nakka, Venkata Prasuja; Prakash-babu, Phanithi; Vemuganti, Raghu

    2014-01-01

    Endoplasmic reticulum (ER) stress induces a variety of neuronal cell death pathways that play a critical role in the pathophysiology of Stroke. ER stress occurs when unfolded/misfolded proteins accumulate and the folding capacity of ER chaperones exceeds the capacity of ER lumen to facilitate their disposal. As a consequence, a complex set of signaling pathways will be induced that transmit from ER to cytosol and nucleus to compensate damage and to restore the normal cellular homeostasis, collectively known as unfolded protein response (UPR). However, failure of UPR due to severe or prolonged stress leads to cell death. Following acute CNS injuries, chronic disturbances in protein folding and oxidative stress prolong ER stress leading to sustained ER dysfunction and neuronal cell death. While ER stress responses have been well studied after stroke, there is an emerging need to study the association of ER stress with other cell pathways that exacerbate neuronal death after an injury. In this review we summarize the current understanding of the role for ER stress in acute brain injuries, highlighting the diverse molecular mechanisms associated with ER stress and its relation to oxidative stress and autophagy. We also discussed the existing and developing therapeutic options aimed to reduce ER stress to protect the CNS after acute injuries. PMID:25482050

  9. mTOR inhibition increases cell viability via autophagy induction during endoplasmic reticulum stress – An experimental and modeling study

    Directory of Open Access Journals (Sweden)

    Orsolya Kapuy

    2014-01-01

    Full Text Available Unfolded or misfolded proteins in the endoplasmic reticulum (ER trigger an adaptive ER stress response known as unfolded protein response (UPR. Depending on the severity of ER stress, either autophagy-controlled survival or apoptotic cell death can be induced. The molecular mechanisms by which UPR controls multiple fate decisions have started to emerge. One such molecular mechanism involves a master regulator of cell growth, mammalian target of rapamycin (mTOR, which paradoxically is shown to have pro-apoptotic role by mutually interacting with ER stress response. How the interconnections between UPR and mTOR influence the dynamics of autophagy and apoptosis activation is still unclear. Here we make an attempt to explore this problem by using experiments and mathematical modeling. The effect of perturbed mTOR activity in ER stressed cells was studied on autophagy and cell viability by using agents causing mTOR pathway inhibition (such as rapamycin or metyrapone. We observed that mTOR inhibition led to an increase in cell viability and was accompanied by an increase in autophagic activity. It was also shown that autophagy was activated under conditions of severe ER stress but that in the latter phase of stress it was inhibited at the time of apoptosis activation. Our mathematical model shows that both the activation threshold and temporal dynamics of autophagy and apoptosis inducers are sensitive to variation in mTOR activity. These results confirm that autophagy has cytoprotective role and is activated in mutually exclusive manner with respect to ER stress levels.

  10. 'Omics' for microbial food stability: Proteomics for the development of predictive models for bacterial spore stress survival and outgrowth.

    Science.gov (United States)

    Abhyankar, Wishwas; Stelder, Sacha; de Koning, Leo; de Koster, Chris; Brul, Stanley

    2017-01-02

    Bacterial spores are ubiquitous in nature. They are stress resistant entities that are a concern to microbiological food stability due to their environmental stress resistance. In addition germinating and outgrowing spores at undesired times and places pose a significant health burden. The challenge is amplified due to the heterogeneous germination and outgrowth behaviour of isogenic spore populations. We discuss the role of different 'omics' techniques, proteomics in particular, to study spore biology in detail. With examples, the use of label-based and label-free quantitative proteomics approaches in understanding the spore physiology is demonstrated. Also the need of genomics, single cell analyses and analysis of cellular physiology is discussed briefly. Certainly accurate comprehensive data obtained from omics methods and molecular physiology will underpin the development of robust molecular models of bacterial spore germination and outgrowth. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Ammonia exposure induces oxidative stress, endoplasmic reticulum stress and apoptosis in hepatopancreas of pacific white shrimp (Litopenaeus vannamei).

    Science.gov (United States)

    Liang, Zhongxiu; Liu, Rui; Zhao, Depeng; Wang, Lingling; Sun, Mingzhe; Wang, Mengqiang; Song, Linsheng

    2016-07-01

    Ammonia is one of major environmental pollutants in the aquatic system that poses a great threat to the survival of shrimp. In the present study, the mRNA expression of endoplasmic reticulum (ER) stress marker and unfolded protein response (UPR) related genes, as well as the change of redox enzyme and apoptosis were investigated in hepatopancreas of the pacific white shrimp, Litopenaeus vannamei after the exposure of 20 mg L(-1) total ammonia nitrogen (TAN). Compared with the control group, the superoxide dismutase (SOD) activity in hepatopancreas decreased significantly (p vannamei after exposure to ammonia by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. The results indicated that ammonia exposure could induce oxidative stress, which further caused ER stress and apoptosis in hepatopancreas of L. vannamei. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. The Influence of the Toxin/Antitoxin mazEF on Growth and Survival of Listeria monocytogenes under Stress

    DEFF Research Database (Denmark)

    Curtis, Thomas; Takeuchi, Ippei; Gram, Lone

    2017-01-01

    A major factor in the resilience of Listeria monocytogenes is the alternative sigma factor B (σB). Type II Toxin/Antitoxin (TA) systems are also known to have a role in the bacterial stress response upon activation via the ClpP or Lon proteases. Directly upstream of the σB operon in L. monocytoge......A major factor in the resilience of Listeria monocytogenes is the alternative sigma factor B (σB). Type II Toxin/Antitoxin (TA) systems are also known to have a role in the bacterial stress response upon activation via the ClpP or Lon proteases. Directly upstream of the σB operon in L....... monocytogenes is the TA system mazEF, which can cleave mRNA at UACMU sites. In this study, we showed that the mazEF TA locus does not affect the level of persister formation during treatment with antibiotics in lethal doses, but exerts different effects according to the sub-inhibitory stress added. Growth...

  13. Pre-emptive Quality Control Protects the ER from Protein Overload via the Proximity of ERAD Components and SRP

    Directory of Open Access Journals (Sweden)

    Hisae Kadowaki

    2015-11-01

    Full Text Available Cells possess ER quality control systems to adapt to ER stress and maintain their function. ER-stress-induced pre-emptive quality control (ER pQC selectively degrades ER proteins via translocational attenuation during ER stress. However, the molecular mechanism underlying this process remains unclear. Here, we find that most newly synthesized endogenous transthyretin proteins are rerouted to the cytosol without cleavage of the signal peptide, resulting in proteasomal degradation in hepatocytes during ER stress. Derlin family proteins (Derlins, which are ER-associated degradation components, reroute specific ER proteins, but not ER chaperones, from the translocon to the proteasome through interactions with the signal recognition particle (SRP. Moreover, the cytosolic chaperone Bag6 and the AAA-ATPase p97 contribute to the degradation of ER pQC substrates. These findings demonstrate that Derlins-mediated substrate-specific rerouting and Bag6- and p97-mediated effective degradation contribute to the maintenance of ER homeostasis without the need for translocation.

  14. Mechanisms of Translocation of ER Chaperones to the Cell Surface and Immunomodulatory Roles in Cancer and Autoimmunity

    NARCIS (Netherlands)

    Wiersma, Valerie; Michalak, Marek; Abdullah, Trefa M; Bremer, Edwin; Eggleton, Paul

    2015-01-01

    Endoplasmic reticulum (ER) chaperones (e.g., calreticulin, heat shock proteins, and isomerases) perform a multitude of functions within the ER. However, many of these chaperones can translocate to the cytosol and eventually the surface of cells, particularly during ER stress induced by e.g., drugs,

  15. High concentration calcitriol induces endoplasmic reticulum stress related gene profile in breast cancer cells.

    Science.gov (United States)

    Ozkaya, Ali Burak; Ak, Handan; Aydin, Hikmet Hakan

    2017-04-01

    Calcitriol, the active form of vitamin D, is known for its anticancer properties including induction of apoptosis as well as the inhibition of angiogenesis and metastasis. Understanding the mechanisms of action for calcitriol will help with the development of novel treatment strategies. Since vitamin D exerts its cellular actions via binding to its receptor and by altering expressions of a set of genes, we aimed to evaluate the effect of calcitriol on transcriptomic profile of breast cancer cells. We previously demonstrated that calcitriol alters endoplasmic reticulum (ER) stress markers, therefore in this study we have focused on ER-stress-related genes to reveal calcitriols action on these genes in particular. We have treated breast cancer cell lines MCF-7 and MDA-MB-231 with previously determined IC50 concentrations of calcitriol and evaluated the transcriptomic alterations via microarray. During analysis, only genes altered by at least 2-fold with a P value < 0.05 were taken into consideration. Our findings revealed an ER-stress-associated transcriptomic profile induced by calcitriol. Induced genes include genes with a pro-survival function (NUPR1, DNAJB9, HMOX1, LCN2, and LAMP3) and with a pro-death function (CHOP (DDIT3), DDIT4, NDGR1, NOXA, and CLGN). These results suggest that calcitriol induces an ER-stress-like response inducing both pro-survival and pro-death transcripts in the process.

  16. Rouw mag er zijn

    Directory of Open Access Journals (Sweden)

    Marlieke Moors

    2015-12-01

    Full Text Available ABSTRACTGrieving is allowedGrief is a human experience. Every form of loss shapes you into the human being you are today. Contrary to what earlier, unproven grief models postulate, grief does not have an end point. That is, bereavement does not have to be completely processed, but it should be integrated into someone’s life. The outdated grief models were often interpreted and used in a normative way, which led to a normative standard model. This portraits the belief that every mourner would experience similar symptoms and would go through a fixed pattern of phases. However, the updated vision emphasizes the individual and unique process of coping with loss: norms concerning grief should be banned. By means of literature research, interviews with professionals and personal experiences, it became clear that finding an equilibrium between restoration-orientated and loss-orientated coping styles is most beneficial. An important aspect in finding this balance is meaningfulness. Furthermore, the ability to bear a loss and to adapt accordingly are important components. Lastly, attaching significance to a loss is a constructive way of integrating the loss into one’s life. The death of a loved one should therefore not be forgotten or tucked away. After all, grief is the price we pay for love. SAMENVATTINGRouw mag er zijnRouw is een menselijke ervaring en elk verlies vormt je als mens. Rouw heeft, in tegenstelling tot wat de verouderde, niet bewezen rouwmodellen beweren, geen eindpunt. Verlies hoeft namelijk niet verwerkt te worden, maar moet juist geïntegreerd worden in iemands leven. De verouderde rouwmodellen zijn vaak normatief opgevat en toegepast, waaruit een normatief standaardmodel is ontstaan. Daarbij werd gedacht dat elke rouwende dezelfde symptomen zou vertonen en het rouwproces volgens vaste fasen zou verlopen. Binnen de vernieuwde visie wordt er juist van uitgegaan dat elk individu een unieke manier van reageren op rouw heeft. Er zou

  17. The role of BmoR, a MarR Family Regulator, in the survival of Bacteroides fragilis during oxidative stress.

    Science.gov (United States)

    Teixeira, Felipe Lopes; Silva, Deborah Nascimento Dos Santos; Pauer, Heidi; Ferreira, Livia Queiroz; Ferreira, Eliane de Oliveira; Domingues, Regina Maria Cavalcanti Pilotto; Lobo, Leandro Araujo

    2013-12-01

    The intestinal opportunistic pathogen Bacteroides fragilis is among the most aerotolerant species of strict anaerobic bacteria and survives exposure to atmospheric oxygen for up to 72h. Under these circumstances, a strong oxygen stress response (OSR) mechanism is activated and the expression of as much as 45% of B. fragilis genes is altered. One of the most important regulators of this response is the product of the oxyR gene, but other regulation systems are in place during the OSR. The MarR family of transcriptional regulators has been shown to control several physiological events in bacteria, including response to stress conditions. In B. fragilis, at least three homologs of MarR regulators are present, one of which, bmoR, is upregulated during oxidative stress independently of oxyR. In this study, we demonstrate that the inactivation of the bmoR gene in B. fragilis diminishes its ability to withstand oxidative stress caused either by exposure to atmospheric oxygen or hydrogen peroxide. Recovery of growth rate on pre-oxidized media under anaerobiosis is slower than that observed in parental strain. Addition of hydrogen peroxide has a similar effect on the growth rate. Complementation of the mutant strain partially recovered the oxygen resistance phenotype, but the overexpression of the gene in the parental strain was also deleterious to a lesser extent. Our results indicate that BmoR has a role in the OSR in B. fragilis, particularly in the initial stages of oxygen exposure. Copyright © 2013 Elsevier GmbH. All rights reserved.

  18. Alt er ændret. Intet er afklaret

    DEFF Research Database (Denmark)

    Helmersen, Ole

    2017-01-01

    Brexit kan redefinere landets internationale rolle lige så meget som Suezkrisen. Men 15 måneder efter afstemningen er der stadig ingen svar.......Brexit kan redefinere landets internationale rolle lige så meget som Suezkrisen. Men 15 måneder efter afstemningen er der stadig ingen svar....

  19. Melatonin Modulates Neuronal Cell Death Induced by Endoplasmic Reticulum Stress under Insulin Resistance Condition

    Directory of Open Access Journals (Sweden)

    Juhyun Song

    2017-06-01

    Full Text Available Insulin resistance (IR is an important stress factor in the central nervous system, thereby aggravating neuropathogenesis and triggering cognitive decline. Melatonin, which is an antioxidant phytochemical and synthesized by the pineal gland, has multiple functions in cellular responses such as apoptosis and survival against stress. This study investigated whether melatonin modulates the signaling of neuronal cell death induced by endoplasmic reticulum (ER stress under IR condition using SH-SY5Y neuroblastoma cells. Apoptosis cell death signaling markers (cleaved Poly [ADP-ribose] polymerase 1 (PARP, p53, and Bax and ER stress markers (phosphorylated eIF2α (p-eIF2α, ATF4, CHOP, p-IRE1, and spliced XBP1 (sXBP1 were measured using reverse transcription-PCR, quantitative PCR, and western blottings. Immunofluorescence staining was also performed for p-ASK1 and p-IRE1. The mRNA or protein expressions of cell death signaling markers and ER stress markers were increased under IR condition, but significantly attenuated by melatonin treatment. Insulin-induced activation of ASK1 (p-ASK1 was also dose dependently attenuated by melatonin treatment. The regulatory effect of melatonin on neuronal cells under IR condition was associated with ASK1 signaling. In conclusion, the result suggested that melatonin may alleviate ER stress under IR condition, thereby regulating neuronal cell death signaling.

  20. Pre-cultivation with Selected Prebiotics Enhances the Survival and the Stress Response of Lactobacillus rhamnosus Strains in Simulated Gastrointestinal Transit

    Science.gov (United States)

    Succi, Mariantonietta; Tremonte, Patrizio; Pannella, Gianfranco; Tipaldi, Luca; Cozzolino, Autilia; Romaniello, Rossana; Sorrentino, Elena; Coppola, Raffaele

    2017-01-01

    In our study, we dwelled upon combinations of lactobacilli/prebiotics, considering four different strains belonging to the Lactobacillus rhamnosus species, including Lactobacillus rhamnosus GG (LGG), and different prebiotics often found in commercial synbiotic products, such as inulin, lactulose and polyols mannitol and sorbitol. In the first step of the research, the survival, the growth kinetic parameters and the protein expression of Lb. rhamnosus strains cultivated in presence of the different prebiotics as a unique carbon source were evaluated. In the second step, the influence of pre-cultivation in medium added of metabolizable prebiotics on the strains survival to simulated gastrointestinal (GI) transit, assayed without prebiotics addition, was estimated. Our results showed that the presence in the medium of certain low fermented prebiotics, specific for each strain, represents a stress factor that significantly affects the growth of Lb. rhamnosus strains, inducing the up-regulation of several proteins. In detail, all added prebiotics used as unique carbon source caused a growth retard compared with glucose, as testified by increased values of the lag phase and decreased values of the μmax. Mannitol evidenced intermediate μmax values between those registered with glucose and those detected with the other assayed prebiotics. Moreover, the cultivation with prebiotics induced the over expression of 7 protein bands. Interestingly, we found a correlation between the up-regulation of two specific stress proteins, called P4 (ATP-binding subunit Clpx) and P7 (GrpE), and the death kinetic parameters (resistance and cells viability) registered during the simulated GI transit of strains pre-cultivated with specific, low fermented prebiotics. Specifically, the highest resistance and gastric-vitality scores were highlighted for the strain AT195 when pre-cultivated in presence of sorbitol. Conversely, the lowest values were found in the case of DSM20021 pre

  1. Er talesprog en medieteknologi?

    DEFF Research Database (Denmark)

    Tække, Jesper

    2013-01-01

    for den menneskelige udfoldelse. Til at løse denne opgave vil jeg trække på den tyske sociolog og systemteoretiker Niklas Luhmann der også udmærker sig som medieteoretiker (Tække 2006a). Luhmann har ikke selv direkte redegjort for sprog som teknologi, men da han både har udviklet et brugbart...... motiver og viden, må give mening til hvad, der meddeles og selektere en forståelse (Luhmann 2000a). Formålet med og berettigelsen for medieteo