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Sample records for alleviate er stress

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

    PubMed

    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.

  2. Betaine prevented fructose-induced NAFLD by regulating LXRα/PPARα pathway and alleviating ER stress in rats.

    PubMed

    Ge, Chen-Xu; Yu, Rong; Xu, Min-Xuan; Li, Pei-Qin; Fan, Chen-Yu; Li, Jian-Mei; Kong, Ling-Dong

    2016-01-01

    Betaine has been proven effective in treating nonalcoholic fatty liver disease (NAFLD) in animal models, however, its molecular mechanisms remain elusive. The aims of this study were to explore the mechanisms mediating the anti-inflammatory and anti-lipogenic actions of betaine in fructose-fed rats. In this study, betaine improved insulin resistance, reduced body weight gain and serum lipid levels, and prevented hepatic lipid accumulation in fructose-fed rats. It up-regulated hepatic expression of liver X receptor-alpha (LXRα) and peroxisome proliferator-activated receptor-alpha (PPARα), with the attenuation of the changes of their target genes, including hepatic carnitine palmitoyl transferase (CPT) 1α, glycosylphosphatidylinositol anchored high density lipoprotein binding protein 1, apolipoprotein B, sterol regulatory element-binding protein 1c and adipocyte differentiation-related protein, involved in fatty acid oxidation and lipid storage in these model rats. Furthermore, betaine alleviated ER stress and inhibited acetyl-CoA carboxylase α, CPT II, stearoyl-CoA desaturase 1 and fatty acid synthase expression involved in fatty acid synthesis in the liver of fructose-fed rats. Betaine suppressed hepatic gluconeogenesis in fructose-fed rats by moderating protein kinase B -forkhead box protein O1 pathway, as well as p38 mitogen-activated protein kinase and mammalian target of rapamycin activity. Moreover, betaine inhibited hepatic nuclear factor kappa B /nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 inflammasome activation-mediated inflammation in this animal model. These results demonstrated that betaine ameliorated hepatic lipid accumulation, gluconeogenesis, and inflammation through restoring LXRα and PPARα expression and alleviating ER stress in fructose-fed rats. This study provides the potential mechanisms of betaine involved in the treatment of NAFLD.

  3. Lactobacillus rhamnosus GG improves glucose tolerance through alleviating ER stress and suppressing macrophage activation in db/db mice

    PubMed Central

    Park, Kun-Young; Kim, Bobae; Hyun, Chang-Kee

    2015-01-01

    Although recent studies have reported that Lactobacillus rhamnosus GG (LGG), the most extensively studied probiotic strain, exerts an anti-hyperglycemic effect on several rodent models, the underlying mechanism remains unclear. In this study, twenty male C57BL/KsJ-db/db (db/db) mice were divided into 2 groups, LGG-treated and control group, which received a daily dose of LGG (1 × 108 CFU per mouse) and PBS orally for 4 weeks, respectively. We observed that glucose tolerance was significantly improved in LGG-treated db/db mice. Insulin-stimulated Akt phosphorylation and GLUT4 translocation were higher in skeletal muscle of LGG-treated mice relative to their controls. It was also observed that LGG treatment caused significant reductions in endoplasmic reticulum (ER) stress in skeletal muscle and M1-like macrophage activation in white adipose tissues. Our results indicate that the anti-diabetic effect of LGG in db/db mice is associated with alleviated ER stress and suppressed macrophage activation, resulting in enhanced insulin sensitivity. These findings suggest a therapeutic potential of probiotics for prevention and treatment of type 2 diabetes. PMID:26060355

  4. Thermotolerance induced at a mild temperature of 40°C alleviates heat shock-induced ER stress and apoptosis in HeLa cells.

    PubMed

    Bettaieb, Ahmed; Averill-Bates, Diana A

    2015-01-01

    Hyperthermia (39-45°C) has emerged as an alternate prospect for cancer therapy in combination with radiation and chemotherapy. Despite promising progress in the clinic, molecular mechanisms involved in hyperthermia-induced cell death are not clear. Hyperthermia causes protein denaturation/aggregation, which results in cell death by apoptosis and/or necrosis. Hyperthermia also induces thermotolerance, which renders cells resistant to subsequent exposure to lethal heat shock. This study investigates the role of both lethal (42-43°C) and mild (40°C) hyperthermia in regulating ER stress and ER stress-induced apoptosis in HeLa cells. The ability of mild thermotolerance induced at 40°C to alleviate either or both of these processes is also determined. Hyperthermia (42-43°C) induced ER stress, revealed by phosphorylation of PERK, eIF2α and IRE1α, cleavage of ATF6 and increased expression of BiP and sXBP1. Real-time PCR revealed that mRNA levels of ATF6, ATF4, BiP, sXBP1 and CHOP increased in cells exposed to hyperthermia. Moreover, hyperthermia caused disruption of calcium homeostasis and activated the calpain-calpastatin proteolytic system and ER resident caspase 4. Pre-exposure to mild hyperthermia (40°C) alleviated the induction of cytotoxicity and ER stress by hyperthermia (42-43°C) and protected cells against ER stress-induced apoptosis. ShRNA-mediated depletion of Hsp72 abrogated protective effects of mild thermotolerance (40°C) against heat-shock induced ER stress and sensitized cells to ER stress-mediated apoptosis. Our findings show that Hsp72 contributes to the protective effects of mild hyperthermia (40°C) against hyperthermia-induced ER stress and apoptosis.

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

    PubMed Central

    Dash, Srikanta; Chava, Srinivas; Aydin, Yucel; Chandra, Partha K.; Ferraris, Pauline; Chen, Weina; Balart, Luis A.; Wu, Tong; Garry, Robert F.

    2016-01-01

    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. PMID:27223299

  6. Do Carpets Alleviate Stress?

    PubMed Central

    HOKI, Yoko; SATO, Kunio; KASAI, Yuichi

    2016-01-01

    Background: Owing to increased complexity in the evolution of society, stress has become an important public health problem, and is responsible for more than 30 types of diseases. Most of the research on stress conducted to date has focused on physical and psychological aspects; however, there are very few reports about the association between psychological stress and elements within the residential environment, such as the home, room, and furniture. Therefore, in this study, we focused on the effects of indoor flooring in the residential environment on stress, as flooring is a feature that the human body is in contact with for long periods of time. We objectively measured the extent of psychological stress perceived while walking on carpeting and on wood flooring. Methods: Forty-two healthy subjects were recruited for this study, and were asked to walk on carpeting and wood flooring for 10 min each. Their electroencephalogram (EEG) and skin impedance values were measured for each task. Results: The α-wave content percentage in EEG data and skin impedance values were significantly higher just after walking on carpet than just after walking on wood flooring. Conclusion: Walking on carpeting induces less stress than walking on wood flooring.

  7. Do Carpets Alleviate Stress?

    PubMed Central

    HOKI, Yoko; SATO, Kunio; KASAI, Yuichi

    2016-01-01

    Background: Owing to increased complexity in the evolution of society, stress has become an important public health problem, and is responsible for more than 30 types of diseases. Most of the research on stress conducted to date has focused on physical and psychological aspects; however, there are very few reports about the association between psychological stress and elements within the residential environment, such as the home, room, and furniture. Therefore, in this study, we focused on the effects of indoor flooring in the residential environment on stress, as flooring is a feature that the human body is in contact with for long periods of time. We objectively measured the extent of psychological stress perceived while walking on carpeting and on wood flooring. Methods: Forty-two healthy subjects were recruited for this study, and were asked to walk on carpeting and wood flooring for 10 min each. Their electroencephalogram (EEG) and skin impedance values were measured for each task. Results: The α-wave content percentage in EEG data and skin impedance values were significantly higher just after walking on carpet than just after walking on wood flooring. Conclusion: Walking on carpeting induces less stress than walking on wood flooring. PMID:27648413

  8. ER Stress and Angiogenesis.

    PubMed

    Binet, François; Sapieha, Przemyslaw

    2015-10-01

    Proper tissue vascularization is vital for cellular function as it delivers oxygen, nutrients, hormones, and immune cells and helps to clear cellular debris and metabolic waste products. Tissue angiogenesis occurs to satisfy energy requirements and cellular sensors of metabolic imbalance coordinate vessel growth. In this regard, the classical pathways of the unfolded protein response activated under conditions of ER stress have recently been described to generate angiomodulatory or angiostatic signals. This review elaborates on the link between angiogenesis and ER stress and discusses the implications for diseases characterized by altered vascular homeostasis, such as cancer, retinopathies, and atherosclerosis.

  9. Membrane expansion alleviates endoplasmic reticulum stress independently of the unfolded protein response

    PubMed Central

    Prinz, William A.; Thorn, Kurt S.; Voss, Christiane; Walter, Peter

    2009-01-01

    Cells constantly adjust the sizes and shapes of their organelles according to need. In this study, we examine endoplasmic reticulum (ER) membrane expansion during the unfolded protein response (UPR) in the yeast Saccharomyces cerevisiae. We find that membrane expansion occurs through the generation of ER sheets, requires UPR signaling, and is driven by lipid biosynthesis. Uncoupling ER size control and the UPR reveals that membrane expansion alleviates ER stress independently of an increase in ER chaperone levels. Converting the sheets of the expanded ER into tubules by reticulon overexpression does not affect the ability of cells to cope with ER stress, showing that ER size rather than shape is the key factor. Thus, increasing ER size through membrane synthesis is an integral yet distinct part of the cellular program to overcome ER stress. PMID:19948500

  10. Epithelial ER Stress in Crohn's Disease and Ulcerative Colitis.

    PubMed

    Cao, Stewart S

    2016-04-01

    Research in the past decade has greatly expanded our understanding of the pathogenesis of inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. In addition to the sophisticated network of immune response, the epithelial layer lining the mucosa has emerged as an essential player in the development and persistence of intestinal inflammation. As the frontline of numerous environmental insults in the gut, the intestinal epithelial cells are subject to various cellular stresses. In eukaryotic cells, disturbance of endoplasmic reticulum homeostasis may lead to the accumulation of unfolded and misfolded proteins in the ER lumen, a condition called ER stress. This cellular process activates the unfolded protein response, which functions to enhance the ER protein folding capacity, alleviates the burden of protein synthesis and maturation, and activates ER-associated protein degradation. Paneth and goblet cells, 2 secretory epithelial populations in the gut, are particularly sensitive to ER stress on environmental or genetic disturbances. Recent studies suggested that epithelial ER stress may contribute to the pathogenesis of Crohn's disease and ulcerative colitis by compromising protein secretion, inducing epithelial cell apoptosis and activating proinflammatory response in the gut. Our knowledge of ER stress in intestinal epithelial function may open avenue to new inflammatory bowel disease therapies by targeting the ER protein folding homeostasis in the cells lining the intestinal mucosa.

  11. ER stress: Autophagy induction, inhibition and selection

    PubMed Central

    Rashid, Harun-Or; Yadav, Raj Kumar; Kim, Hyung-Ryong; Chae, Han-Jung

    2015-01-01

    An accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) leads to stress conditions. To mitigate such circumstances, stressed cells activate a homeostatic intracellular signaling network cumulatively called the unfolded protein response (UPR), which orchestrates the recuperation of ER function. Macroautophagy (hereafter autophagy), an intracellular lysosome-mediated bulk degradation pathway for recycling and eliminating wornout proteins, protein aggregates, and damaged organelles, has also emerged as an essential protective mechanism during ER stress. These 2 systems are dynamically interconnected, and recent investigations have revealed that ER stress can either stimulate or inhibit autophagy. However, the stress-associated molecular cues that control the changeover switch between induction and inhibition of autophagy are largely obscure. This review summarizes the crosstalk between ER stress and autophagy and their signaling networks mainly in mammalian-based systems. Additionally, we highlight current knowledge on selective autophagy and its connection to ER stress. PMID:26389781

  12. Endoplasmic reticulum: ER stress regulates mitochondrial bioenergetics.

    PubMed

    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

    2012-01-01

    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

  13. Causes and Alleviation of Occupational Stress in Child Care Work

    ERIC Educational Resources Information Center

    Dillenburger, Karola

    2004-01-01

    Occupational stress in not a new phenomenon in the working population. However, in the helping professions it has only recently attracted attention. The survey reported here was carried out in order to assess the extent of occupational stress, identify its causes, and suggest ways in which occupational stress can be alleviated. Field social…

  14. ER Stress-Induced Clearance of Misfolded GPI-Anchored Proteins via the Secretory Pathway

    PubMed Central

    Satpute-Krishnan, Prasanna; Ajinkya, Monica; Bhat, Savithri; Itakura, Eisuke; Hegde, Ramanujan S.; Lippincott-Schwartz, Jennifer

    2014-01-01

    Summary Proteins destined for the cell surface are first assessed in the endoplasmic reticulum (ER) for proper folding before release into the secretory pathway. This ensures that defective proteins are normally prevented from entering the extracellular environment, where they could be disruptive. Here, we report that, when ER folding capacity is saturated during stress, misfolded glycosylphosphatidylinositol-anchored proteins dissociate from resident ER chaperones, engage export receptors, and quantitatively leave the ER via vesicular transport to the Golgi. Clearance from the ER commences within minutes of acute ER stress, before the transcriptional component of the unfolded protein response is activated. These aberrant proteins then access the cell surface transiently before destruction in lysosomes. Inhibiting this stress-induced pathway by depleting the ER-export receptors leads to aggregation of the ER-retained misfolded protein. Thus, this rapid response alleviates the elevated burden of misfolded proteins in the ER at the onset of ER stress, promoting protein homeostasis in the ER. PMID:25083867

  15. Obesity and endoplasmic reticulum (ER) stresses

    PubMed Central

    Tripathi, Yamini B.; Pandey, Vivek

    2012-01-01

    In obesity, the adipose cells behave as inflammatory source and result to low grade inflammation. This systemic inflammation along with oxidative stress is a silent killer and damages other vital organs also. High metabolic process, induced due to high nutritional intake, results to endoplasmic reticulum (ER) stress and mitochondrial stress. This review describes the triggering factor and basic mechanism behind the obesity mediated these stresses in relation to inflammation. Efforts have been made to describe the effect-response cycle between adipocytes and non-adipocyte cells with reference to metabolic syndrome (MS). PMID:22891067

  16. Black tea protects against hypertension-associated endothelial dysfunction through alleviation of endoplasmic reticulum stress.

    PubMed

    San Cheang, Wai; Yuen Ngai, Ching; Yen Tam, Ye; Yu Tian, Xiao; Tak Wong, Wing; Zhang, Yang; Wai Lau, Chi; Chen, Zhen Yu; Bian, Zhao-Xiang; Huang, Yu; Ping Leung, Fung

    2015-01-01

    Hypertensive patients have been found to be associated with elevated levels of homocysteine, known as hyperhomocysteinemia. Homocysteine (Hcy) can induce endoplasmic reticulum (ER) stress in endothelial cells. This study aims to investigate whether black tea (BT) protects against hypertension-associated endothelial dysfunction through alleviation of ER stress. Rat aortae and cultured rat aortic endothelial cells were treated with Hcy, BT extract, and theaflavin-3,3'-digallate (TF3). Male Sprague Dawley rats were infused with angiotensin II (Ang II) to induce hypertension and orally administrated with BT extract at 15 mg/kg/day for 2 weeks. Hcy impaired endothelium-dependent relaxations of rat aortae and led to ER stress in endothelial cells, which were ameliorated by co-incubation of BT extract and TF3. The blood pressure of Ang II-infused rats and plasma Hcy level were normalized by BT consumption. Impaired endothelium-dependent relaxations in renal arteries, carotid arteries and aortae, and flow-mediated dilatations in third-order mesenteric resistance arteries were improved. Elevations of ER stress markers and ROS level, plus down-regulation of Hcy metabolic enzymes in aortae from Ang II-infused rats were prevented by BT treatment. Our data reveal the novel cardiovascular benefits of BT in ameliorating vascular dysfunctions, providing insight into developing BT into beneficial dietary supplements in hypertensive patients. PMID:25976123

  17. Black tea protects against hypertension-associated endothelial dysfunction through alleviation of endoplasmic reticulum stress

    PubMed Central

    San Cheang, Wai; Yuen Ngai, Ching; Yen Tam, Ye; Yu Tian, Xiao; Tak Wong, Wing; Zhang, Yang; Wai Lau, Chi; Chen, Zhen Yu; Bian, Zhao-Xiang; Huang, Yu; Ping Leung, Fung

    2015-01-01

    Hypertensive patients have been found to be associated with elevated levels of homocysteine, known as hyperhomocysteinemia. Homocysteine (Hcy) can induce endoplasmic reticulum (ER) stress in endothelial cells. This study aims to investigate whether black tea (BT) protects against hypertension-associated endothelial dysfunction through alleviation of ER stress. Rat aortae and cultured rat aortic endothelial cells were treated with Hcy, BT extract, and theaflavin-3,3’-digallate (TF3). Male Sprague Dawley rats were infused with angiotensin II (Ang II) to induce hypertension and orally administrated with BT extract at 15 mg/kg/day for 2 weeks. Hcy impaired endothelium-dependent relaxations of rat aortae and led to ER stress in endothelial cells, which were ameliorated by co-incubation of BT extract and TF3. The blood pressure of Ang II-infused rats and plasma Hcy level were normalized by BT consumption. Impaired endothelium-dependent relaxations in renal arteries, carotid arteries and aortae, and flow-mediated dilatations in third-order mesenteric resistance arteries were improved. Elevations of ER stress markers and ROS level, plus down-regulation of Hcy metabolic enzymes in aortae from Ang II-infused rats were prevented by BT treatment. Our data reveal the novel cardiovascular benefits of BT in ameliorating vascular dysfunctions, providing insight into developing BT into beneficial dietary supplements in hypertensive patients. PMID:25976123

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

    PubMed

    Suzuki, Takahiro; Shimoda, Masami; Ito, Kumpei; Hanai, Shuji; Aizawa, Hidenobu; Kato, Tomoki; Kawasaki, Kazunori; Yamaguchi, Terumi; Ryoo, Hyung Don; Goto-Inoue, Naoko; Setou, Mitsutoshi; Tsuji, Shoji; Ishida, Norio

    2013-01-01

    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.

  19. Arbuscular mycorrhizal fungi in alleviation of salt stress: a review

    PubMed Central

    Evelin, Heikham; Kapoor, Rupam; Giri, Bhoopander

    2009-01-01

    Background Salt stress has become a major threat to plant growth and productivity. Arbuscular mycorrhizal fungi colonize plant root systems and modulate plant growth in various ways. Scope This review addresses the significance of arbuscular mycorrhiza in alleviation of salt stress and their beneficial effects on plant growth and productivity. It also focuses on recent progress in unravelling biochemical, physiological and molecular mechanisms in mycorrhizal plants to alleviate salt stress. Conclusions The role of arbuscular mycorrhizal fungi in alleviating salt stress is well documented. This paper reviews the mechanisms arbuscular mycorrhizal fungi employ to enhance the salt tolerance of host plants such as enhanced nutrient acquisition (P, N, Mg and Ca), maintenance of the K+ : Na+ ratio, biochemical changes (accumulation of proline, betaines, polyamines, carbohydrates and antioxidants), physiological changes (photosynthetic efficiency, relative permeability, water status, abscissic acid accumulation, nodulation and nitrogen fixation), molecular changes (the expression of genes: PIP, Na+/H+ antiporters, Lsnced, Lslea and LsP5CS) and ultra-structural changes. Theis review identifies certain lesser explored areas such as molecular and ultra-structural changes where further research is needed for better understanding of symbiosis with reference to salt stress for optimum usage of this technology in the field on a large scale. This review paper gives useful benchmark information for the development and prioritization of future research programmes. PMID:19815570

  20. Curcumin alleviates oxidative stress and mitochondrial dysfunction in astrocytes.

    PubMed

    Daverey, Amita; Agrawal, Sandeep K

    2016-10-01

    Oxidative stress plays a critical role in various neurodegenerative diseases, thus alleviating oxidative stress is a potential strategy for therapeutic intervention and/or prevention of neurodegenerative diseases. In the present study, alleviation of oxidative stress through curcumin is investigated in A172 (human glioblastoma cell line) and HA-sp (human astrocytes cell line derived from the spinal cord) astrocytes. H2O2 was used to induce oxidative stress in astrocytes (A172 and HA-sp). Data show that H2O2 induces activation of astrocytes in dose- and time-dependent manner as evident by increased expression of GFAP in A172 and HA-sp cells after 24 and 12h respectively. An upregulation of Prdx6 was also observed in A172 and HA-sp cells after 24h of H2O2 treatment as compared to untreated control. Our data also showed that curcumin inhibits oxidative stress-induced cytoskeleton disarrangement, and impedes the activation of astrocytes by inhibiting upregulation of GFAP, vimentin and Prdx6. In addition, we observed an inhibition of oxidative stress-induced inflammation, apoptosis and mitochondria fragmentation after curcumin treatment. Therefore, our results suggest that curcumin not only protects astrocytes from H2O2-induced oxidative stress but also reverses the mitochondrial damage and dysfunction induced by oxidative stress. This study also provides evidence for protective role of curcumin on astrocytes by showing its effects on attenuating reactive astrogliosis and inhibiting apoptosis.

  1. ER stress and ER stress-induced apoptosis are activated in gastric SMCs in diabetic rats

    PubMed Central

    Chen, Xia; Fu, Xiang-Sheng; Li, Chang-Ping; Zhao, Hong-Xian

    2014-01-01

    AIM: To investigate the gastric muscle injury caused by endoplasmic reticulum (ER) stress in rats with diabetic gastroparesis. METHODS: Forty rats were randomly divided into two groups: a control group and a diabetic group. Diabetes was induced by intraperitoneal injection of 60 mg/kg of streptozotocin. Gastric emptying was determined at the 4th and 12th week. The ultrastructural changes in gastric smooth muscle cells (SMCs) were investigated by transmission electron microscopy. TdT-mediated dUTP nick end labeling (TUNEL) assay was performed to assess apoptosis of SMCs. Expression of the ER stress marker, glucose-regulated protein 78 (GRP78), and the ER-specific apoptosis mediator, caspase-12 protein, was determined by immunohistochemistry. RESULTS: Gastric emptying was significantly lower in the diabetic rats than in the control rats at the 12th wk (40.71% ± 2.50%, control rats vs 54.65% ± 5.22%, diabetic rats; P < 0.05). Swollen and distended ER with an irregular shape was observed in gastric SMCs in diabetic rats. Apoptosis of gastric SMCs increased in the diabetic rats in addition to increased expression of GRP78 and caspase-12 proteins. CONCLUSION: ER stress and ER stress-mediated apoptosis are activated in gastric SMCs in diabetic rats with gastroparesis. PMID:25009401

  2. Focused grooming networks and stress alleviation in wild female baboons.

    PubMed

    Wittig, Roman M; Crockford, Catherine; Lehmann, Julia; Whitten, Patricia L; Seyfarth, Robert M; Cheney, Dorothy L

    2008-06-01

    We examine the relationship between glucocorticoid (GC) levels and grooming behavior in wild female baboons during a period of instability in the alpha male rank position. All females' GC levels rose significantly at the onset of the unstable period, though levels in females who were at lower risk of infanticide began to decrease sooner in the following weeks. Three factors suggest that females relied on a focused grooming network as a coping mechanism to alleviate stress. First, all females' grooming networks became less diverse in the weeks following the initial upheaval. Second, females whose grooming had already focused on a few predictable partners showed a less dramatic rise in GC levels than females whose grooming network had been more diverse. Third, females who contracted their grooming network the most experienced a greater decrease in GC levels in the following week. We conclude that close bonds with a few preferred partners allow female baboons to alleviate the stress associated with social instability.

  3. ER stress, autophagy, and RNA viruses

    PubMed Central

    Jheng, Jia-Rong; Ho, Jin-Yuan; Horng, Jim-Tong

    2014-01-01

    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. PMID:25140166

  4. Caffeine attenuated ER stress-induced leptin resistance in neurons.

    PubMed

    Hosoi, Toru; Toyoda, Keisuke; Nakatsu, Kanako; Ozawa, Koichiro

    2014-05-21

    Exposing the endoplasmic reticulum (ER) to stress causes the accumulation of unfolded proteins, and subsequently results in ER stress. ER stress may be involved in various disorders such as obesity, diabetes, and neurodegenerative diseases. Leptin is an important circulating hormone, that inhibits food intake and accelerates energy consumption, which suppresses body weight gain. Recent studies demonstrated that leptin resistance is one of the main factors involved in the development of obesity. We and other groups recently reported the role of ER stress in the development of leptin resistance. Therefore, identifying drugs that target ER stress may be a promising fundamental strategy for the treatment of obesity. In the present study, we investigated whether caffeine could affect ER stress and the subsequent development of leptin resistance. We showed that caffeine exhibited chaperone activity, which attenuated protein aggregation. Caffeine also inhibited the ER stress-induced activation of IRE1 and PERK, which suggested the attenuation of ER stress. Moreover, caffeine markedly improved ER stress-induced impairments in the leptin-induced phosphorylation of STAT3. Therefore, these results suggest caffeine may have pharmacological properties that ameliorate leptin resistance by reducing ER stress. PMID:24699176

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

    PubMed

    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.

  6. Dopamine alleviates salt-induced stress in Malus hupehensis.

    PubMed

    Li, Chao; Sun, Xiangkai; Chang, Cong; Jia, Dongfeng; Wei, Zhiwei; Li, Cuiying; Ma, Fengwang

    2015-04-01

    Dopamine mediates many physiological processes in plants. We investigated its role in regulating growth, ion homeostasis and the response to salinity in Malus hupehensis Rehd. Both hydroponics and field-pot experiments were conducted under saline conditions. Salt-stressed plants had reduced growth and a marked decline in their net photosynthetic rates, values for Fv /Fm and chlorophyll contents. However, pretreatment with 100 or 200 μM dopamine significantly alleviated this inhibition and enabled plants to maintain their photosynthetic capacity. In addition to changing stomatal behavior, supplementation with dopamine positively influenced the uptake of K, N, P, S, Cu and Mn ions but had an inhibitory effect on Na and Cl uptake, the balance of which is responsible for managing the response to salinity by Malus plants. Dopamine pretreatment also controlled the burst of hydrogen peroxide, possibly through direct scavenging and by enhancing the activities of antioxidative enzymes and the capacity of the ascorbate-glutathione cycle. We also investigated whether dopamine might regulate salt overly sensitive pathway genes under salinity. Here, MdHKT1, MdNHX1 and MdSOS1 were greatly upregulated in roots and leaves, which possibly contributed to the maintenance of ion homeostasis and, thus, improved salinity resistance in plants exposed earlier to exogenous dopamine. These results support our conclusion that dopamine alleviates salt-induced stress not only at the level of antioxidant defense but also by regulating other mechanisms of ion homeostasis.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26442866

  8. Candida albicans autophagy, no longer a bystander: Its role in tolerance to ER stress-related antifungal drugs.

    PubMed

    Yu, Qilin; Jia, Chang; Dong, Yijie; Zhang, Bing; Xiao, Chenpeng; Chen, Yulu; Wang, Yuzhou; Li, Xiaoling; Wang, Lei; Zhang, Biao; Li, Mingchun

    2015-08-01

    Autophagy is a degradation process involved in pathogenicity of many pathogenic fungi. However, its roles in Candida albicans, the leading fungal pathogen in human beings, remain to be detailed. Most recently, we found that endoplasmic reticulum (ER) stress-inducing conditions led to transcriptional up-regulation of C. albicans autophagy-related (ATG) genes, implying a possible link between autophagy and ER stress response in this pathogen. Using a series of C. albicans ATG mutants and autophagy reporting systems, we found that both treatment of ER stress-related drugs and loss of the ER calcium pump Spf1 promoted autophagic flux of Atg8 and Lap41 (a homologue of Saccharomyces cerevisiae Ape1), indicating that these conditions induce autophagy. Moreover, deletion of ATG genes in the spf1Δ/Δ mutant rendered cells hypersensitive to these drugs and caused activation of UPR, revealing a role of autophagy in alleviating ER stress. In addition, only treatment of tunicamycin and loss of Spf1 in combination increased autophagic flux of the ER component Sec63, suggesting that most of the ER stress-related conditions cause non-selective autophagy rather than selective ER phagy. This study uncovers the important role of C. albicans autophagy in ER stress response and tolerance to antifungal drugs.

  9. Melatonin alleviates cadmium-induced cellular stress and germ cell apoptosis in testes.

    PubMed

    Ji, Yan-Li; Wang, Hua; Meng, Can; Zhao, Xian-Feng; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Meng, Xiu-Hong; Xu, De-Xiang

    2012-01-01

    Increasing evidence demonstrates that melatonin has an anti-apoptotic effect in somatic cells. However, whether melatonin can protect against germ cell apoptosis remains obscure. Cadmium (Cd) is a testicular toxicant and induces germ cell apoptosis. In this study, we investigated the effects of melatonin on Cd-evoked germ cell apoptosis in testes. Male ICR mice were intraperitoneally (i.p.) injected with melatonin (5 mg/kg) every 8 hr, beginning at 8 hr before CdCl(2) (2.0 mg/kg, i.p.). As expected, acute Cd exposure resulted in germ cell apoptosis in testes, as determined by terminal dUTP nick-end labeling (TUNEL) staining. Melatonin significantly alleviated Cd-induced testicular germ cell apoptosis. An additional experiment showed that spliced form of XBP-1, the target of the IRE-1 pathway, was significantly increased in testes of mice injected with CdCl(2). GRP78, an endoplasmic reticulum (ER) chaperone, and CHOP, a downstream target of the PERK pathway, were upregulated in testes of Cd-treated mice. In addition, acute Cd exposure significantly increased testicular eIF2α and JNK phosphorylation, indicating that the unfolded protein response (UPR) pathway was activated by CdCl(2). Interestingly, melatonin almost completely inhibited Cd-induced ER stress and the UPR in testes. In addition, melatonin obviously attenuated Cd-induced heme oxygenase (HO)-1 expression and protein nitration in testes. Taken together, these results suggest that melatonin alleviates Cd-induced cellular stress and germ cell apoptosis in testes. Melatonin may be useful as pharmacological agents to protect against Cd-induced testicular toxicity. PMID:21793897

  10. Coumarin pretreatment alleviates salinity stress in wheat seedlings.

    PubMed

    Saleh, Ahmed Mahmoud; Madany, M M Y

    2015-03-01

    The potentiality of COU to improve plant tolerance to salinity was investigated. Wheat grains were primed with COU (50 ppm) and then grown under different levels of NaCl (50, 100, 150 mM) for two weeks. COU pretreatment improved the growth of wheat seedling under salinity, relative to COU-untreated seedlings, due to the accumulation of osmolytes such as soluble sugars and proline. Moreover, COU treatment significantly improved K(+)/Na(+) ratio in the shoots of both salt stressed and un-stressed seedlings. However, in the roots, this ratio increased only under non-salinity. In consistent with phenylalanine ammonia lyase (PAL), phenolics and flavonoids were accumulated in COU-pretreated seedlings under the higher doses of salinity, relative to COU-untreated seedlings. COU primed seedlings showed higher content of the coumarin derivative, scopoletin, and salicylic, chlorogenic, syringic, vanillic, gallic and ferulic acids, under both salinity and non-salinity conditions. Salinity stress significantly improved the activity of peroxidase (POD) in COU-pretreated seedlings. However, the effect of COU on the total antioxidant capacity (TAC) was only obtained at the highest dose of NaCl (150 mM). The present results suggest that COU pretreatment could alleviate the adverse effect of salinity on the growth of wheat seedlings through enhancing, at least partly, the osmoregulation process and antioxidant defense system.

  11. ER Stress-induced Aberrant Neuronal Maturation and Neurodevelopmental Disorders.

    PubMed

    Kawada, Koichi; Iekumo, Takaaki; Kaneko, Masayuki; Nomura, Yasuyuki; Okuma, Yasunobu

    2016-01-01

    Neurodevelopmental disorders, which include autism spectrum disorder, are congenital impairments in the growth and development of the central nervous system. They are mainly accentuated during infancy and childhood. Autism spectrum disorder may be caused by environmental factors, genomic imprinting of chromosome 15q11-q13 regions, and gene defects such as those in genes encoding neurexin and neuroligin, which are involved in synaptogenesis and synaptic signaling. However, regardless of the many reports on neurodevelopmental disorders, the pathogenic mechanism and treatment of neurodevelopmental disorders remain unclear. Conversely, it has been reported that endoplasmic reticulum (ER) stress is involved in neurodegenerative diseases. ER stress is increased by environmental factors such as alcohol consumption and smoking. Here we show the recent results on ER stress-induced neurodevelopmental disorders. ER stress led to a decrease in the mRNA levels of the proneural factors Hes1/5 and Pax6, which maintain an undifferentiated state of the neural cells. This stress also led to a decrease in nestin expression and an increase in beta-III tubulin expression. In addition, dendrite length was shortened by ER stress in microtubule-associated protein-2 (MAP-2) positive cells. However, the ubiquitin ligase HRD1 expression was increased by ER stress. By suppressing HRD1 expression, the ER stress-induced decrease in nestin and MAP-2 expression and increase in beta-III tubulin returned to control levels. Therefore, we suggest that ER stress induces abnormalities in neuronal differentiation and maturation via HRD1 expression. These results suggest that targeting ER stress may facilitate quicker approaches toward the prevention and treatment of neurodevelopmental disorders. PMID:27252060

  12. Different fatty acids inhibit apoB100 secretion by different pathways: unique roles for ER stress, ceramide, and autophagy

    PubMed Central

    Caviglia, Jorge Matias; Gayet, Constance; Ota, Tsuguhito; Hernandez-Ono, Antonio; Conlon, Donna M.; Jiang, Hongfeng; Fisher, Edward A.; Ginsberg, Henry N.

    2011-01-01

    Although short-term incubation of hepatocytes with oleic acid (OA) stimulates secretion of apolipoprotein B100 (apoB100), exposure to higher doses of OA for longer periods inhibits secretion in association with induction of endoplasmic reticulum (ER) stress. Palmitic acid (PA) induces ER stress, but its effects on apoB100 secretion are unclear. Docosahexaenoic acid (DHA) inhibits apoB100 secretion, but its effects on ER stress have not been studied. We compared the effects of each of these fatty acids on ER stress and apoB100 secretion in McArdle RH7777 (McA) cells: OA and PA induced ER stress and inhibited apoB100 secretion at higher doses; PA was more potent because it also increased the synthesis of ceramide. DHA did not induce ER stress but was the most potent inhibitor of apoB100 secretion, acting via stimulation of autophagy. These unique effects of each fatty acid were confirmed when they were infused into C57BL6J mice. Our results suggest that when both increased hepatic secretion of VLDL apoB100 and hepatic steatosis coexist, reducing ER stress might alleviate hepatic steatosis but at the expense of increased VLDL secretion. In contrast, increasing autophagy might reduce VLDL secretion without causing steatosis. PMID:21719579

  13. 2,4-dichlorophenol induces ER stress-mediated apoptosis via eIF2α dephosphorylation in vitro.

    PubMed

    Zhang, Xiaoning; Zhang, Xiaona; Qi, Yongmei; Huang, Dejun; Zhang, Yingmei

    2016-02-01

    2,4-Dichlorophenol (2,4-DCP) has been widely used to produce herbicides and pharmaceutical intermediates, which exhibits various toxic effects including apoptosis. However, the mechanisms underlying 2,4-DCP-induced apoptosis, especially mediated by endoplasmic reticulum (ER) stress, are still unknown. In the present study, the mouse embryonic fibroblasts (MEFs) were used as an in vitro model system to figure out whether 2,4-DCP could induce ER stress, and further to elucidate the role of ER stress in 2,4-DCP-induced apoptosis. The results showed that 2,4-DCP dramatically caused the decrease of cell viability, the increase of apoptotic cells, the collapse of mitochondrial membrane potential (MMP) and the activation of caspase-3, suggesting that 2,4-DCP did induce apoptosis. Meanwhile, 2,4-DCP acted similarly as ER stress agonist tunicamycin (Tu) to activate all three branches (IRE1α, ATF6 and eIF2α) of ER stress. Furthermore, repression of ER stress or inhibition of eIF2α dephosphorylation significantly alleviated 2,4-DCP-induced apoptosis. Taking these results together, the present study firstly showed that 2,4-DCP induced ER stress-mediated apoptosis via eIF2α dephosphorylation in mammalian cells. These findings will provide new insights into the mechanisms underlying apoptosis after chlorophenols exposure.

  14. Chemical chaperones reduce ER stress and adipose tissue inflammation in high fat diet-induced mouse model of obesity

    PubMed Central

    Chen, Yaqin; Wu, Zhihong; Zhao, Shuiping; Xiang, Rong

    2016-01-01

    Obesity, which is characteristic by chronic inflammation, is defined as abnormal or excessive fat accumulation in adipose tissues. Endoplasmic reticulum (ER) stress is increased in adipose tissue of obese state and is known to be strongly associated with chronic inflammation. The aim of this study was to investigate the effect of ER stress on adipokine secretion in obese mice and explore the potential mechanisms. In this study, we found high-fat diet induced-obesity contributed to strengthened ER stress and triggered chronic inflammation in adipose tissue. Chemical chaperones, 4-PBA and TUDCA, modified metabolic disorders and decreased the levels of inflammatory cytokines in obese mice fed a high-fat diet. The alleviation of ER stress is in accordance with the decrease of free cholesterol in adipose tissue. Furthermore chemical chaperones suppress NF-κB activity in adipose tissue of obese mice in vivo. In vitro studies showed IKK/NF-κB may be involved in the signal transduction of adipokine secretion dysfunction induced by ER stress. The present study revealed the possibility that inhibition of ER stress may be a novel drug target for metabolic abnormalities associated with obesity. Further studies are now needed to characterize the initial incentive of sustained ER stress in obese. PMID:27271106

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

    PubMed Central

    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

  16. Prolonged ER Stressed-Hepatocytes drives an Alternative Macrophage Polarization

    PubMed Central

    Xiu, Fangming; Catapano, Michael; Diao, Li; Stanojcic, Mile; Jeschke, Marc G.

    2015-01-01

    Relatively little is known about the effects of hepatocytes on hepatic macrophages, particularly under the situation of endoplasmic reticulum (ER) stress. We examined the effects of hepatocytes conditioned media (CM) from HepG2 treated with ER stress inducers, Tunicamycin (TM) or Thapsigargin (TG), on the secretion of cytokines, expression of ER stress markers and polarization of PMA activated THP-1 cells (pTHP-1). We found that CM decreased the production of the pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and interleukin (IL)-1β as well as other cytokines and chemokines from pTHP-1 cells. These effects are mediated by the inhibition of TLR4 expression and NF-κB signaling pathway. In addition, hepatocytes CM increased the expression of binding immunoglobulin protein (BiP) and the transcription factor C/EBP homologous protein (CHOP) in pTHP-1 cells. Preconditioning with ER stress inhibitor, small molecular chaperone 4-phenylbutyrate (PBA) before addition of ER stressors, attenuated the ER stress in macrophages, the property of hepatocytes CM to alter TNF-α production and NF-κB expression by macrophages. Remarkably, treatment of macrophage with these CM leads to an alternative activation of macrophages mediated by peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling pathway, which might be resulted from the secretion of IL-10 and IL-4 as well as releasing apoptotic bodies from hepatocytes under ER stress. Our results highlight a mechanism of ER stress transmission from hepatocytes to macrophage that drives an alternative activation of macrophages, which depends on the exposure of hepatocytes to severe and prolonged ER stress. PMID:25944791

  17. NOD1/NOD2 signaling links ER stress with inflammation

    PubMed Central

    Keestra-Gounder, A. Marijke; Byndloss, Mariana X.; Seyffert, Núbia; Young, Briana M.; Chávez-Arroyo, Alfredo; Tsai, April Y.; Cevallos, Stephanie A.; Winter, Maria G.; Pham, Oanh H.; Tiffany, Connor R.; de Jong, Maarten F.; Kerrinnes, Tobias; Ravindran, Resmi; Luciw, Paul A.; McSorley, Stephen J.; Bäumler, Andreas J.; Tsolis, Renée M.

    2016-01-01

    Endoplasmic reticulum (ER) stress is a major contributor to inflammatory diseases, such as Crohn’s disease and type 2 diabetes1,2. ER stress induces the unfolded protein response (UPR), which involves activation of three transmembrane receptors, ATF6 (activating transcription factor 6), PERK (protein kinase RNA-like endoplasmic reticulum kinase) and IRE1α (inositol-requiring enzyme 1α)3 (Extended Data figure 1a). Once activated, IRE1α recruits TRAF2 (TNF receptor-associated factor 2) to the ER membrane to initiate inflammatory responses via the nuclear factor kappa B (NF-κB) pathway4. Inflammation is commonly triggered when pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) or nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), detect tissue damage or microbial infection. However, it is not clear which PRRs play a major role in inducing inflammation during ER stress. Here we show that NOD1 and NOD2, two members of the NLR family of PRRs, are important mediators of ER stress-induced inflammation. The ER stress inducers thapsigargin and dithiothreitol (DTT) triggered production of the pro-inflammatory cytokine interleukin (IL)-6 in a NOD1/2-dependent fashion. Inflammation and IL-6 production triggered by infection with Brucella abortus, which induces ER stress by injecting the type IV secretion system (T4SS) effector protein VceC into host cells5, was TRAF2, NOD1/2 and RIP2-dependent and could be blunted by treatment with the ER-stress inhibitor tauroursodeoxycholate (TUDCA) or an IRE1α kinase inhibitor. The association of NOD1 and NOD2 with pro-inflammatory responses induced by the IRE1α/TRAF2 signaling pathway provides a novel link between innate immunity and ER stress-induced inflammation. PMID:27007849

  18. β-Arrestin2 encourages inflammation-induced epithelial apoptosis through ER stress/PUMA in colitis.

    PubMed

    Zeng, L X; Tao, J; Liu, H L; Tan, S W; Yang, Y D; Peng, X J; Liu, Z H; Jiang, J; Wu, B

    2015-05-01

    β-Arrestins (β-arrs) are regulators and mediators of G protein-coupled receptor signaling, and accumulating evidence suggests that they are functionally involved in inflammation and autoimmune diseases. However, the effect of β-arrs is unclear in inflammatory bowel disease (IBD), and the role of β-arr2 is unknown in ulcerative colitis (UC) and Crohn's disease (CD). The aim of this study is to investigate whether β-arr2 encourages inflammation-induced epithelial apoptosis through endoplasmic reticulum (ER) stress/p53-upregulated modulator of apoptosis (PUMA) in colitis. In the present study, the results showed that β-arr2 was increased in specimens from patients with UC or CD. Furthermore, a β-arr2 deficiency significantly repressed intestinal inflammation, ameliorated colitis, and alleviated mucosal apoptosis in mice. In addition, the targeted deletion of β-arr2 depressed ER stress, inhibited PUMA, and downregulated PUMA-mediated mitochondrial apoptotic signaling in colitis. β-Arr2, an important modulator of G protein-coupled receptor function, binds eIF2α to activate ER stress signaling. Furthermore, the knockdown of PUMA dramatically prevented β-arr2-induced apoptosis via alleviating ER stress in vitro. The results suggest that β-arr2 encourages inflammation-induced epithelial apoptosis through ER stress/PUMA in colitis and that β-arr2 is a potential therapeutic target for colitis.

  19. Rhizospheric bacteria alleviate salt-produced stress in sunflower.

    PubMed

    Shilev, Stefan; Sancho, Enrique D; Benlloch-González, María

    2012-03-01

    The effect of isolate Pseudomonas fluorescens biotype F and P. fluorescens CECT 378(T) inoculation on fresh weight and ions accumulation was studied in sunflower plants grown in sand:peat substrate with addition of 100mM NaCl. The inoculation resulted in an increase in fresh weight of more than 10% in salt treatments and in an accumulation of less Na(+) and more K(+) in plant tissues in all cases. The bacterial inoculants favoured the K(+)/Na(+) ratio in all plant parts and in the case of the isolate CECT 378(T) conducted to 66% increment in leaves, 34% in stems and 16% in roots, while the effect of isolate inoculation was (only) more evident in leaves and stems with 30% and 26%, respectively. Both strains were found to produce indoleacetic acid and siderophores in in-vitro tests, thus the production of indoles was highly dependent on the exogenous tryptophan in the medium. The results suggest that salt stress in sunflower plants was alleviated partially by the inoculation with strains that produce indoles and siderophores, having also a positive effect on the K(+)/Na(+) ratio in the shoot. Moreover, those plants were characterized with better-developed roots. PMID:20685030

  20. Zinc supplementation alleviates heat stress in laying Japanese quail.

    PubMed

    Sahin, Kazim; Kucuk, Omer

    2003-09-01

    The study was conducted to determine whether zinc supplementation could alleviate the detrimental effects of high ambient temperature (34 degrees C) on egg production, digestibility of nutrients and antioxidant status in laying Japanese quail. Quail (n = 180; 52 d old) were divided into six groups (n = 30/group) and were fed a basal diet or the basal diet supplemented with 30 or 60 mg of zinc (ZnSO(4). H(2)O)/kg diet. Birds were kept at 22 degrees C and 58% relative humidity (RH). At 13 wk of age, the thermoneutral (TN) groups remained at the same temperature, whereas the heat-stress (HS) groups were kept in an environmentally controlled room at 34 degrees C and 42% RH for 3 wk. Heat exposure decreased egg production in birds fed the basal diet (P = 0.001). Linear increases in feed intake (P = 0.01) and egg production (P = 0.004) and improved feed efficiency (P = 0.01) and egg quality variables (P 0.05). Results of the present study suggest that supplementation with 60 mg zinc/kg diet protects quail by reducing the negative effects of heat stress.

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

    PubMed

    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.

  2. ER Protein Processing Under Oxidative Stress: Implications and Prevention.

    PubMed

    Khalil, Mahmoud F; Valenzuela, Carlos; Sisniega, Daniella; Skouta, Rachid; Narayan, Mahesh

    2016-06-01

    Elevated levels of mitochondrial nitrosative stress have been associated with the pathogenesis of both Parkinson's and Alzheimer's diseases. The mechanism involves catalytic poisoning of the endoplasmic reticulum (ER)-resident oxidoreductase chaperone, protein disulfide isomerase (PDI), and the subsequent accumulation of ER-processed substrate proteins. Using a model system to mimic mitochondrial oxidative and nitrosative stress, we demonstrate a PDI-independent mechanism whereby reactive oxygen species (ROS) compromise regeneration rates of disulfide bond-containing ER-processed proteins. Under ROS-duress, the secretion-destined traffic adopts disulfide-exposed structures making the protein flux retrotranslocation biased. We also demonstrate that ROS-compromised protein maturation rates can be rescued by the polyphenol ellagic acid (EA). Our results are significant in that they reveal an additional mechanism which could promote neurodegenerative disorders. Furthermore, our data reveal that EA possesses therapeutic potential as a lead prophylactic agent against oxidative/nitrosative stress-related neurodegenerative diseases. PMID:26983927

  3. Dysfunction of Wntless triggers the retrograde Golgi-to-ER transport of Wingless and induces ER stress

    PubMed Central

    Zhang, Peng; Zhou, Lujun; Pei, Chunli; Lin, Xinhua; Yuan, Zengqiang

    2016-01-01

    Secreted Wnts play diverse roles in a non-cell-autonomous fashion. However, the cell-autonomous effect of unsecreted Wnts remains unknown. Endoplasmic reticulum (ER) stress is observed in specialized secretory cells and participates in pathophysiological processes. The correlation between Wnt secretion and ER stress remains poorly understood. Here, we demonstrated that Drosophila miR-307a initiates ER stress specifically in wingless (wg)-expressing cells through targeting wntless (wls/evi). This phenotype could be mimicked by retromer loss-of-function or porcupine (porc) depletion, and rescued by wg knockdown, arguing that unsecreted Wg triggers ER stress. Consistently, we found that disrupting the secretion of human Wnt5a also induced ER stress in mammalian cells. Furthermore, we showed that a C-terminal KKVY-motif of Wg is required for its retrograde Golgi-to-ER transport, thus inducing ER stress. Next, we investigated if COPI, the regulator of retrograde transport, is responsible for unsecreted Wg to induce ER stress. To our surprise, we found that COPI acts as a novel regulator of Wg secretion. Taken together, this study reveals a previously unknown Golgi-to-ER retrograde route of Wg, and elucidates a correlation between Wnt secretion and ER stress during development. PMID:26887613

  4. Oroxin B selectively induces tumor-suppressive ER stress and concurrently inhibits tumor-adaptive ER stress in B-lymphoma cells for effective anti-lymphoma therapy.

    PubMed

    Yang, Ping; Fu, Shilong; Cao, Zhifei; Liao, Huaidong; Huo, Zihe; Pan, Yanyan; Zhang, Gaochuan; Gao, Aidi; Zhou, Quansheng

    2015-10-15

    Cancer cells have both tumor-adaptive and -suppressive endoplasmic reticulum (ER) stress machineries that determine cell fate. In malignant tumors including lymphoma, constant activation of tumor-adaptive ER stress and concurrent reduction of tumor-suppressive ER stress favors cancer cell proliferation and tumor growth. Current ER stress-based anti-tumor drugs typically activate both tumor-adaptive and -suppressive ER stresses, resulting in low anti-cancer efficacy; hence, selective induction of tumor-suppressive ER stress and inhibition of tumor-adaptive ER stress are new strategies for novel anti-cancer drug discovery. Thus far, specific tumor-suppressive ER stress therapeutics have remained absent in clinical settings. In this study, we explored unique tumor-suppressive ER stress agents from the traditional Chinese medicinal herb Oroxylum indicum, and found that a small molecule oroxin B selectively induced tumor-suppressive ER stress in malignant lymphoma cells, but not in normal cells, effectively inhibited lymphoma growth in vivo, and significantly prolonged overall survival of lymphoma-xenografted mice without obvious toxicity. Mechanistic studies have revealed that the expression of key tumor-adaptive ER-stress gene GRP78 was notably suppressed by oroxin B via down-regulation of up-stream key signaling protein ATF6, while tumor-suppressive ER stress master gene DDIT3 was strikingly activated through activating the MKK3-p38 signaling pathway, correcting the imbalance between tumor-suppressive DDIT3 and tumor-adaptive GRP78 in lymphoma. Together, selective induction of unique tumor-suppressive ER stress and concurrent inhibition of tumor-adaptive ER stress in malignant lymphoma are new and feasible approaches for novel anti-lymphoma drug discovery and anti-lymphoma therapy.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Cardiac-Specific Overexpression of Catalase Attenuates Paraquat-Induced Myocardial Geometric and Contractile Alteration: Role of ER Stress

    PubMed Central

    Ge, We; Zhang, Yingmei; Han, Xuefeng; Ren, Jun

    2010-01-01

    Paraquat, a quarternary nitrogen herbicide, is a highly toxic prooxidant resulting in multi-organ failure including the heart via generation of reactive oxygen species although the underlying mechanism has not been well elucidated. This study examined the influence of cardiac-specific overexpression of catalase, an antioxidant detoxifying H2O2, on paraquat-induced myocardial geometric and functional alterations, with a focus on ER stress. FVB and catalase transgenic mice were administrated paraquat for 48 hrs. Myocardial geometry, contractile function, apoptosis, and ER stress were evaluated using echocardiography, edge-detection, caspase-3 activity and immunoblotting. Our results revealed that paraquat treatment significantly enlarged LV end-diastolic and systolic diameters, increased LV mass and resting myocyte length, reduced fractional shortening, cardiomyocyte peak shortening, maximal velocity of shortening/relengthening and prolonged relengthening duration in FVB group. While catalase transgene itself did not alter myocardial geometry and function, it mitigated or significantly attenuated paraquat-elicited myocardial geometric and functional changes. Paraquat promoted overt apoptosis and ER stress as evidenced by increased caspase-3 activity, apoptosis and ER stress markers including Bax, Bcl-2, GADD153, calregulin and phosphorylation of JNK, IRE1α and eIF2α, all were ablated by catalase transgene. Paraquat-induced cardiomyocyte dysfunction was mitigated by the ER stress inhibitor tauroursodeoxycholic acid. Moreover, the JNK inhibitor SP600125 reversed paraquat-induced ER stress as evidenced by enhanced GADD153 and IRE1α phosphorylation. Taken together, these data revealed that catalase may rescue paraquat-induced myocardial geometric and functional alteration possibly via alleviating JNK-mediated ER stress. PMID:20937379

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

    PubMed

    Zheng, Jinying; Peng, Chuan; Ai, Yanbiao; Wang, Heng; Xiao, Xiaoqiu; Li, Jibin

    2016-01-01

    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. PMID:26805874

  8. Bridges between mitochondrial oxidative stress, ER stress and mTOR signaling in pancreatic β cells.

    PubMed

    Wang, Jing; Yang, Xin; Zhang, Jingjing

    2016-08-01

    Pancreatic β cell dysfunction, i.e., failure to provide insulin in concentrations sufficient to control blood sugar, is central to the etiology of all types of diabetes. Current evidence implicates mitochondrial oxidative stress and endoplasmic reticulum (ER) stress in pancreatic β cell loss and impaired insulin secretion. Oxidative and ER stress are interconnected so that misfolded proteins induce reactive oxygen species (ROS) production; likewise, oxidative stress disturbs the ER redox state thereby disrupting correct disulfide bond formation and proper protein folding. mTOR signaling regulates many metabolic processes including protein synthesis, cell growth, survival and proliferation. Oxidative stress inhibits mTORC1, which is considered an important suppressor of mitochondrial oxidative stress in β cells, and ultimately, controls cell survival. The interplay between ER stress and mTORC1 is complicated, since the unfolded protein response (UPR) activation can occur upstream or downstream of mTORC1. Persistent activation of mTORC1 initiates protein synthesis and UPR activation, while in the later phase induces ER stress. Chronic activation of ER stress inhibits Akt/mTORC1 pathway, while under particular settings, acute activation of UPR activates Akt-mTOR signaling. Thus, modulating mitochondrial oxidative stress and ER stress via mTOR signaling may be an approach that will effectively suppress obesity- or glucolipotoxicity-induced metabolic disorders such as insulin resistance and type 2 diabetes mellitus (T2DM). In this review, we focus on the regulations between mTOR signaling and mitochondrial oxidative or ER stress in pancreatic β cells.

  9. Oxidative stress involving changes in Nrf2 and ER stress in early stages of Alzheimer's disease.

    PubMed

    Mota, Sandra I; Costa, Rui O; Ferreira, Ildete L; Santana, Isabel; Caldeira, Gladys L; Padovano, Carmela; Fonseca, Ana C; Baldeiras, Inês; Cunha, Catarina; Letra, Liliana; Oliveira, Catarina R; Pereira, Cláudia M F; Rego, Ana Cristina

    2015-07-01

    Oxidative stress and endoplasmic reticulum (ER) stress have been associated with Alzheimer's disease (AD) progression. In this study we analyzed whether oxidative stress involving changes in Nrf2 and ER stress may constitute early events in AD pathogenesis by using human peripheral blood cells and an AD transgenic mouse model at different disease stages. Increased oxidative stress and increased phosphorylated Nrf2 (p(Ser40)Nrf2) were observed in human peripheral blood mononuclear cells (PBMCs) isolated from individuals with mild cognitive impairment (MCI). Moreover, we observed impaired ER Ca2+ homeostasis and increased ER stress markers in PBMCs from MCI individuals and mild AD patients. Evidence of early oxidative stress defense mechanisms in AD was substantiated by increased p(Ser40)Nrf2 in 3month-old 3xTg-AD male mice PBMCs, and also with increased nuclear Nrf2 levels in brain cortex. However, SOD1 protein levels were decreased in human MCI PBMCs and in 3xTg-AD mice brain cortex; the latter further correlated with reduced SOD1 mRNA levels. Increased ER stress was also detected in the brain cortex of young female and old male 3xTg-AD mice. We demonstrate oxidative stress and early Nrf2 activation in AD human and mouse models, which fails to regulate some of its targets, leading to repressed expression of antioxidant defenses (e.g., SOD-1), and extending to ER stress. Results suggest markers of prodromal AD linked to oxidative stress associated with Nrf2 activation and ER stress that may be followed in human peripheral blood mononuclear cells.

  10. Capsaicin induces apoptosis in PC12 cells through ER stress.

    PubMed

    Krizanova, Olga; Steliarova, Iveta; Csaderova, Lucia; Pastorek, Michal; Hudecova, Sona

    2014-02-01

    Capsaicin, the pungent agent in chili peppers, has been shown to act as a tumor-suppressor in cancer. In our previous study, capsaicin was shown to induce apoptosis in the rat pheochromocytoma cell line (PC12 cells). Thus, the aim of the present study was to determine the potential mechanism by which capsaicin induces apoptosis. We treated PC12 cells with 50, 100 and 500 µM capsaicin and measured the reticular calcium content and expression of the reticular calcium transport systems. These results were correlated with endoplasmic reticulum (ER) stress markers CHOP, ATF4 and X-box binding protein 1 (XBP1), as well as with apoptosis induction. We observed that capsaicin decreased reticular calcium in a concentration-dependent manner. Simultaneously, expression levels of the sarco/endoplasmic reticulum pump and ryanodin receptor of type 2 were modified. These changes were accompanied by increased ER stress, as documented by increased stress markers. Thus, from these results we propose that in PC12 cells capsaicin induces apoptosis through increased ER stress. PMID:24337105

  11. Residual stress alleviation of aircraft metal structures reinforced with filamentary composites

    NASA Technical Reports Server (NTRS)

    Kelly, J. B.; June, R. R.

    1973-01-01

    Methods to eliminate or reduce residual stresses in aircraft metal structures reinforced by filamentary composites are discussed. Residual stress level reductions were achieved by modifying the manufacturing procedures used during adhesive bonding. The residual stress alleviation techniques involved various forms of mechanical constraint which were applied to the components during bonding. Nine methods were evaluated, covering a wide range in complexity. All methods investigated during the program affected the residual stress level. In general, residual stresses were reduced by 70 percent or more from the stress level produced by conventional adhesive bonding procedures.

  12. Rosa rugosa Aqueous Extract Alleviates Endurance Exercise-Induced Stress.

    PubMed

    Seo, Eunjin; You, Yanghee; Yoon, Ho-Geun; Kim, Boemjeong; Kim, Kyungmi; Lee, Yoo-Hyun; Lee, Jeongmin; Chung, Jin Woong; Shim, Sangin; Jun, Woojin

    2015-06-01

    This study was performed to investigate the effect of water extract from Rosa rugosa (RRW) on endurance exercise-induced stress in mice. The mice were orally administered with distilled water or RRW, respectively. The endurance capacity was evaluated by exhaustive swimming using an adjustable-current water pool. Mice administered RRW swam longer before becoming exhausted. Also, RRW administration resulted in less lipid peroxidation, lower muscular antioxidant enzyme activities, and lower cortisol level. The results suggest that RRW can prevent exercise-induced stress by decreasing oxidative stress levels.

  13. Seed priming to alleviate salinity stress in germinating seeds.

    PubMed

    Ibrahim, Ehab A

    2016-03-15

    Salinity is one of the major abiotic stresses that affect crop production in arid and semiarid areas. Seed germination and seedling growth are the stages most sensitive to salinity. Salt stress causes adverse physiological and biochemical changes in germinating seeds. It can affect the seed germination and stand establishment through osmotic stress, ion-specific effects and oxidative stress. The salinity delays or prevents the seed germination through various factors, such as a reduction in water availability, changes in the mobilization of stored reserves and affecting the structural organization of proteins. Various techniques can improve emergence and stand establishment under salt conditions. One of the most frequently utilized is seed priming. The process of seed priming involves prior exposure to an abiotic stress, making a seed more resistant to future exposure. Seed priming stimulates the pre-germination metabolic processes and makes the seed ready for radicle protrusion. It increases the antioxidant system activity and the repair of membranes. These changes promote seed vigor during germination and emergence under salinity stress. The aim of this paper is to review the recent literature on the response of plants to seed priming under salinity stress. The mechanism of the effect of salinity on seed germination is discussed and the seed priming process is summarized. Physiological, biochemical and molecular changes induced by priming that lead to seed enhancement are covered. Plants' responses to some priming agents under salinity stress are reported based on the best available data. For a great number of crops, little information exists and further research is needed. PMID:26812088

  14. Seed priming to alleviate salinity stress in germinating seeds.

    PubMed

    Ibrahim, Ehab A

    2016-03-15

    Salinity is one of the major abiotic stresses that affect crop production in arid and semiarid areas. Seed germination and seedling growth are the stages most sensitive to salinity. Salt stress causes adverse physiological and biochemical changes in germinating seeds. It can affect the seed germination and stand establishment through osmotic stress, ion-specific effects and oxidative stress. The salinity delays or prevents the seed germination through various factors, such as a reduction in water availability, changes in the mobilization of stored reserves and affecting the structural organization of proteins. Various techniques can improve emergence and stand establishment under salt conditions. One of the most frequently utilized is seed priming. The process of seed priming involves prior exposure to an abiotic stress, making a seed more resistant to future exposure. Seed priming stimulates the pre-germination metabolic processes and makes the seed ready for radicle protrusion. It increases the antioxidant system activity and the repair of membranes. These changes promote seed vigor during germination and emergence under salinity stress. The aim of this paper is to review the recent literature on the response of plants to seed priming under salinity stress. The mechanism of the effect of salinity on seed germination is discussed and the seed priming process is summarized. Physiological, biochemical and molecular changes induced by priming that lead to seed enhancement are covered. Plants' responses to some priming agents under salinity stress are reported based on the best available data. For a great number of crops, little information exists and further research is needed.

  15. Autophagy deficiency leads to accumulation of ubiquitinated proteins, ER stress, and cell death in Arabidopsis

    PubMed Central

    Munch, David; Rodriguez, Eleazar; Bressendorff, Simon; Park, Ohkmae K; Hofius, Daniel; Petersen, Morten

    2014-01-01

    Autophagy is a homeostatic degradation and recycling process that is also involved in defense against microbial pathogens and in certain forms of cellular suicide. Autophagy has been proposed to negatively regulate plant immunity-associated cell death related to the hypersensitive response (HR), as older autophagy-deficient mutants are unable to contain this type of cell death 5 to 10 d after infection. Such spreading cell death was found to require NPR1 (nonexpressor of PR genes 1), but surprisingly did not occur in younger atg mutants. In contrast, we find that npr1 mutants are not impaired in rapid programmed cell death activation upon pathogen recognition. Furthermore, our molecular evidence suggests that the NPR1-dependent spreading cell death in older atg mutants may originate from an inability to cope with excessive accumulation of ubiquitinated proteins and ER stress which derive from salicylic acid (SA)-dependent signaling (e.g., systemic acquired resistance). We also demonstrate that both senescence and immunity-related cell death seen in older atg mutants can be recapitulated in younger atg mutants primed with ER stress. We therefore propose that the reduction in SA signaling caused by npr1 loss-of-function is sufficient to alleviate the stress levels accumulated during aging in autophagy deficient cells which would otherwise become insurmountable and lead to uncontrolled cell death. PMID:25046116

  16. ER-stress in Alzheimer's disease: turning the scale?

    PubMed

    Endres, Kristina; Reinhardt, Sven

    2013-01-01

    Pathogenic mechanisms of Alzheimer's disease (AD) are intensely investigated as it is the most common form of dementia and burdens society by its costs and social demands. While key molecules such as A-beta peptides and tau have been identified decades ago, it is still enigmatic what drives the disease in its sporadic manifestation. Synthesis of A-beta peptides as well as phosphorylation of tau proteins comprise normal cellular functions and occur in principle in the healthy as well as in dementia-affected persons. Dyshomeostasis of Amyloid Precursor Protein (APP) cleavage, energy metabolism or kinase/phosphatase activity due to stressors has been suggested as a trigger of the disease. One way for cells to escape stress based on dysfunction of ER is the unfolded protein response - the UPR. This pathway is composed out of three different routes that differ in proteins involved, targets and consequences for cell fate: activation of transmembrane ER resident kinases IRE1-alpha and PERK or monomerization of membrane-anchored activating transcription factor 6 (ATF6) induce activation of versatile transcription factors (XBP-1, eIF2-alpha/ATF4 and ATF6 P50). These bind to specific DNA sequences on target gene promoters and on one hand attenuate general ER-prone protein synthesis and on the other equip the cell with tools to de-stress. If cells fail in stress compensation, this signaling also is able to evoke apoptosis. In this review we summarized knowledge on how APP processing and phosphorylation of tau might be influenced by ER-stress signaling. In addition, we depicted the effects UPR itself seems to have on molecules closely related to AD and describe what is known about UPR in AD animal models as well as in human patients. PMID:24319643

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

    SciTech Connect

    Katoh, Hironori; Fujita, Keiko; Takuhara, Yuki; Ogawa, Atsushi; Suzuki, Shunji

    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.

  18. Herbaspirillum sp. strain GW103 alleviates salt stress in Brassica rapa L. ssp. pekinensis.

    PubMed

    Lee, Gun Woong; Lee, Kui-Jae; Chae, Jong-Chan

    2016-05-01

    Mutual interactions between plant and rhizosphere bacteria facilitate plant growth and reduce risks of biotic and abiotic stresses. The present study demonstrates alleviation of salt stress in Brassica rapa L. ssp. perkinensis (Chinese cabbage) by Herbaspirillum sp. strain GW103 isolated from rhizosphere soil of Phragmites australis. The strain was capable of producing plant beneficial factors, such as auxin, siderophore, and 1-aminocylopropane-1-carboxylic acid deaminase. Treatment of strain GW103 on Chinese cabbage under salt stress increased K(+)/Na(+) ratio in roots generating balance in the ratio of ion homeostasis and consequently contributed to the increase of biomass. In addition, root colonization potential of the strain was observed by green fluorescent protein (GFP)-tagging approach. These results strongly suggest the beneficial impact of strain GW103 by inducing the alleviation of salt stress and development of stress tolerance in Chinese cabbage via plant-microbe interaction.

  19. Herbaspirillum sp. strain GW103 alleviates salt stress in Brassica rapa L. ssp. pekinensis.

    PubMed

    Lee, Gun Woong; Lee, Kui-Jae; Chae, Jong-Chan

    2016-05-01

    Mutual interactions between plant and rhizosphere bacteria facilitate plant growth and reduce risks of biotic and abiotic stresses. The present study demonstrates alleviation of salt stress in Brassica rapa L. ssp. perkinensis (Chinese cabbage) by Herbaspirillum sp. strain GW103 isolated from rhizosphere soil of Phragmites australis. The strain was capable of producing plant beneficial factors, such as auxin, siderophore, and 1-aminocylopropane-1-carboxylic acid deaminase. Treatment of strain GW103 on Chinese cabbage under salt stress increased K(+)/Na(+) ratio in roots generating balance in the ratio of ion homeostasis and consequently contributed to the increase of biomass. In addition, root colonization potential of the strain was observed by green fluorescent protein (GFP)-tagging approach. These results strongly suggest the beneficial impact of strain GW103 by inducing the alleviation of salt stress and development of stress tolerance in Chinese cabbage via plant-microbe interaction. PMID:26358119

  20. Cholesterol biosynthesis and ER stress in peroxisome deficiency.

    PubMed

    Faust, Phyllis L; Kovacs, Werner J

    2014-03-01

    Cholesterol biosynthesis is a multi-step process involving more than 20 enzymes in several subcellular compartments. The pre-squalene segment of the cholesterol/isoprenoid biosynthetic pathway is localized in peroxisomes. This review intends to highlight recent findings illustrating the important role peroxisomes play in cholesterol biosynthesis and maintenance of cholesterol homeostasis. Disruption of the Pex2 gene leads to peroxisome deficiency and widespread metabolic dysfunction. The Pex2(-/-) mouse model for Zellweger syndrome enabled us to evaluate the role of peroxisomes in cholesterol biosynthesis. These studies have shown that Pex2(-/-) mice exhibit low levels of cholesterol in plasma and liver. Pex2(-/-) mice were unable to maintain normal cholesterol homeostasis despite activation of SREBP-2, the master transcriptional regulator of cholesterol biosynthesis, and increased protein levels and activities of cholesterol biosynthetic enzymes. The SREBP-2 pathway remained activated even after normalization of hepatic cholesterol levels in response to bile acid feeding as well as in extrahepatic tissues and the liver of neonatal and longer surviving Pex2 mutants, where cholesterol levels were normal. Several studies have shown that endoplasmic reticulum (ER) stress can dysregulate lipid metabolism via SREBP activation independently of intracellular cholesterol concentration. We demonstrated that peroxisome deficiency activates endoplasmic reticulum stress pathways in Pex2(-/-) mice, especially the integrated stress response mediated by PERK and ATF4 signaling, and thereby leads to dysregulation of the SREBP-2 pathway. Our findings suggest that functional peroxisomes are necessary to prevent chronic ER stress and dysregulation of the endogenous sterol response pathway. The constitutive activation of ER stress pathways might contribute to organ pathology and metabolic dysfunction in peroxisomal disorder patients.

  1. Method for alleviating thermal stress damage in laminates

    NASA Technical Reports Server (NTRS)

    Hoffman, C. A.; Weeton, J. W.; Orth, N. W. (Inventor)

    1981-01-01

    The method is for metallic matrix composites, such as laminated sheet or foil composites. Non-intersecting discrete discontinuities are positively introduced into the interface between the layers so as to reduce the thermal stress produced by unequal expansion of the materials making up the composite. The discontinuities are preferably produced by drilling holes in the metallic matrix layer. However, a plurality of discrete elements may be used between the layers to carry out this purpose.

  2. Hyperoside Induces Endogenous Antioxidant System to Alleviate Oxidative Stress

    PubMed Central

    Park, Ji Young; Han, Xia; Piao, Mei Jing; Oh, Min Chang; Fernando, Pattage Madushan Dilhara Jayatissa; Kang, Kyoung Ah; Ryu, Yea Seong; Jung, Uhee; Kim, In Gyu; Hyun, Jin Won

    2016-01-01

    Background: Hyperoside, a flavonoid which is mainly found in Hypericum perforatum L., has many biological effects. One of the most important effects is to prevent the oxidative stress induced by reactive oxygen species. However, the molecular mechanisms underlying its effect are not fully understood. Oxidative stress is implicated in the occurrence of various physical diseases. A wide array of enzymatic antioxidant defense systems include NADH: quinone oxidoreductase 1, superoxide dismutase, and heme oxygenase-1 (HO-1). In the present study, the protective effects of hyperoside against hydrogen peroxide-induced oxidative stress in human lens epithelial cells, HLE-B3, were investigated in terms of HO-1 induction. Methods: The protein and mRNA expressions of HO-1 were examined by Western blotting and reverse transcriptase-PCR assays, respectively. To evaluate the ability of hyperoside to activate nuclear factor erythroid 2-related factor 2 (Nrf2), Western blotting and electrophoretic mobility shift assay were performed with nuclear extracts prepared from HLE-B3 cells treated with hyperoside. The activation of extracellular signal-regulated kinase (ERK), the upstream kinase of Nrf2 signaling, was monitored by Western blot analysis. The protective effect of hyperoside in HLE-B3 cells against hydrogen peroxide was performed by MTT assay. Results: Hyperoside increased both the mRNA and protein expression of HO-1 in a time- and dose-dependent manner. In addition, hyperoside elevated the level of of Nrf2 and its antioxidant response element-binding activity, which was modulated by upstream of ERK. Moreover, it activated ERK and restored cell viability which was decreased by hydrogen peroxide. Conclusions: Hyperoside is an effective compound to protect cells against oxidative stress via HO-1 induction. PMID:27051648

  3. Alleviation of salt stress in lemongrass by salicylic acid.

    PubMed

    Idrees, Mohd; Naeem, M; Khan, M Nasir; Aftab, Tariq; Khan, M Masroor A; Moinuddin

    2012-07-01

    Soil salinity is one of the key factors adversely affecting the growth, yield, and quality of crops. A pot study was conducted to find out whether exogenous application of salicylic acid could ameliorate the adverse effect of salinity in lemongrass (Cymbopogon flexuosus Steud. Wats.). Two Cymbopogon varieties, Krishna and Neema, were used in the study. Three salinity levels, viz, 50, 100, and 150 mM of NaCl, were applied to 30-day-old plants. Salicylic acid (SA) was applied as foliar spray at 10(-5) M concentration. Totally, six SA-sprays were carried out at 10-day intervals, following the first spray at 30 days after sowing. The growth parameters were progressively reduced with the increase in salinity level; however, growth inhibition was significantly reduced by the foliar application of SA. With the increase in salt stress, a gradual decrease in the activities of carbonic anhydrase and nitrate reductase was observed in both the varieties. SA-treatment not only ameliorated the adverse effects of NaCl but also showed a significant improvement in the activities of these enzymes compared with the untreated stressed-plants. The plants supplemented with NaCl exhibited a significant increase in electrolyte leakage, proline content, and phosphoenol pyruvate carboxylase activity. Content and yield of essential oil was also significantly decreased in plants that received salinity levels; however, SA overcame the unfavorable effects of salinity stress to a considerable extent. Lemongrass variety Krishna was found to be more adapted to salt stress than Neema, as indicated by the overall performance of the two varieties under salt conditions.

  4. Addition lens alleviates reading-induced ocular stress.

    PubMed

    Choy, Camus K; Siu, Andrew W; Lam, Frankie Y; Tse, Jesse T; Lau, Sylvania Y

    2000-01-01

    BACKGROUND: Near tasks have been associated with binocular stress to induce myopia. The aim of this study was to investigate the effects of accommodation on reading-induced near heterophoria. METHODS: We measured the near heterophoria of 22 young adults before and after 30 minutes of reading. The reading task comprised a column of local English newsletter studied monocularly at 33 cm. One of three addition lenses (that is, 0.00 D, +1.50 D and +3.00 D) was randomly incorporated into the optical prescription. The difference in near heterophoria between the pre- and post-reading task was recorded. The experiment was completed on separate days for the other lens powers. RESULTS: Reading for 30 minutes with a plano lens addition (control) increased the near heterophoria by 3.81 +/- 0.95 prism dioptres (SEM) toward exo-deviation (p < 0.002). Addition of a +3.00 D lens significantly decreased the reading-induced exophoric shift to 1.36 +/- 0.55 prism dioptres (SEM). Similarly, a +1.50 D lens reduced the exophoric shift to 3.14 +/- 0.85 prism dioptres (SEM) but the difference was not statistically significant when compared with the control. CONCLUSIONS: The results showed that close work might cause eye strain via the extraocular muscles. Incorporation of plus lens into the optical correction caused a power-dependent reduction in the stress, that is, smaller exophoric shift. Whether binocular stress contributes to myopia and its response to addition lens therapy deserve further investigation.

  5. ER stress and apoptosis: a new mechanism for retinal cell death.

    PubMed

    Jing, Guangjun; Wang, Joshua J; Zhang, Sarah X

    2012-01-01

    The endoplasmic reticulum (ER) is the primary subcellular organelle where proteins are synthesized and folded. When the homeostasis of the ER is disturbed, unfolded or misfolded proteins accumulate in the ER lumen, resulting in ER stress. In response to ER stress, cells activate a set of tightly controlled regulatory programs, known as the unfolded protein response (UPR), to restore the normal function of the ER. However, if ER stress is sustained and the adaptive UPR fails to eliminate unfolded/misfolded proteins, apoptosis will occur to remove the stressed cells. In recent years, a large body of studies has shown that ER stress-induced apoptosis is implicated in numerous human diseases, such as diabetes and neurogenerative diseases. Moreover, emerging evidence supports a role of ER stress in retinal apoptosis and cell death in blinding disorders such as age-related macular degeneration and diabetic retinopathy. In the present review, we summarize recent progress on ER stress and apoptosis in retinal diseases, focusing on various proapoptotic and antiapoptotic pathways that are activated by the UPR, and discuss how these pathways contribute to ER stress-induced apoptosis in retinal cells.

  6. Calcium homoeostasis modulator 1 (CALHM1) reduces the calcium content of the endoplasmic reticulum (ER) and triggers ER stress.

    PubMed

    Gallego-Sandín, Sonia; Alonso, María Teresa; García-Sancho, Javier

    2011-08-01

    CALHM1 (calcium homoeostasis modulator 1), a membrane protein with similarity to NMDA (N-methyl-D-aspartate) receptor channels that localizes in the plasma membrane and the ER (endoplasmic reticulum) of neurons, has been shown to generate a plasma-membrane Ca(2+) conductance and has been proposed to influence Alzheimer's disease risk. In the present study we have investigated the effects of CALHM1 on intracellular Ca(2+) handling in HEK-293T [HEK (human embryonic kidney)-293 cells expressing the large T-antigen of SV40 (simian virus 40)] cells by using targeted aequorins for selective monitorization of Ca(2+) transport by organelles. We find that CALHM1 increases Ca(2+) leak from the ER and, more importantly, reduces ER Ca(2+) uptake by decreasing both the transport capacity and the Ca(2+) affinity of SERCA (sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase). As a result, the Ca(2+) content of the ER is drastically decreased. This reduction in the Ca(2+) content of the ER triggered the UPR (unfolded protein response) with induction of several ER stress markers, such as CHOP [C/EBP (CCAAT/enhancer-binding protein)-homologous protein], ERdj4, GRP78 (glucose-regulated protein of 78 kDa) and XBP1 (X-box-binding protein 1). Thus CALHM1 might provide a relevant link between Ca(2+) homoeostasis disruption, ER stress and cell damage in the pathogenesis of neurodegenerative diseases.

  7. ER stress does not cause upregulation and activation of caspase-2 to initiate apoptosis.

    PubMed

    Sandow, J J; Dorstyn, L; O'Reilly, L A; Tailler, M; Kumar, S; Strasser, A; Ekert, P G

    2014-03-01

    A recent report claimed that endoplasmic reticulum (ER) stress activates the ER trans-membrane receptor IRE1α, leading to increased caspase-2 levels via degradation of microRNAs, and consequently induction of apoptosis. This observation casts caspase-2 into a central role in the apoptosis triggered by ER stress. We have used multiple cell types from caspase-2-deficient mice to test this hypothesis but failed to find significant impact of loss of caspase-2 on ER-stress-induced apoptosis. Moreover, we did not observe increased expression of caspase-2 protein in response to ER stress. Our data strongly argue against a critical role for caspase-2 in ER-stress-induced apoptosis.

  8. Regulation of OSU-03012 toxicity by ER stress proteins and ER stress-inducing drugs.

    PubMed

    Booth, Laurence; Roberts, Jane L; Cruickshanks, Nichola; Grant, Steven; Poklepovic, Andrew; Dent, Paul

    2014-10-01

    The present studies examined the toxic interaction between the non-coxib celecoxib derivative OSU-03012 and phosphodiesterase 5 (PDE5) inhibitors, and also determined the roles of endoplasmic reticulum stress response regulators in cell survival. PDE5 inhibitors interacted in a greater than additive fashion with OSU-03012 to kill parental glioma and stem-like glioma cells. Knockdown of the endoplasmic reticulum stress response proteins IRE1 or XBP1 enhanced the lethality of OSU-03012, and of [OSU-03012 + PDE5 inhibitor] treatment. Pan-caspase and caspase-9 inhibition did not alter OSU-03012 lethality but did abolish enhanced killing in the absence of IRE1 or XBP1. Expression of the mitochondrial protective protein BCL-XL or the caspase-8 inhibitor c-FLIP-s, or knockdown of death receptor CD95 or the death receptor caspase-8 linker protein FADD, suppressed killing by [OSU-03012 + PDE5 inhibitor] treatment. CD95 activation was blocked by the nitric oxide synthase inhibitor L-NAME. Knockdown of the autophagy regulatory proteins Beclin1 or ATG5 protected the cells from OSU-03012 and from [OSU-03012 + PDE5 inhibitor] toxicity. Knockdown of IRE1 enhanced OSU-03012/[OSU-03012 + PDE5 inhibitor]-induced JNK activation, and inhibition of JNK suppressed the elevated killing caused by IRE1 knockdown. Knockdown of CD95 blunted JNK activation. Collectively, our data demonstrate that PDE5 inhibitors recruit death receptor signaling to enhance OSU-03012 toxicity in glioblastoma multiforme (GBM) cells. PMID:25103559

  9. Seed treatment with Trichoderma harzianum alleviates biotic, abiotic, and physiological stresses in germinating seeds and seedlings.

    PubMed

    Mastouri, Fatemeh; Björkman, Thomas; Harman, Gary E

    2010-11-01

    Trichoderma spp. are endophytic plant symbionts that are widely used as seed treatments to control diseases and to enhance plant growth and yield. Although some recent work has been published on their abilities to alleviate abiotic stresses, specific knowledge of mechanisms, abilities to control multiple plant stress factors, their effects on seed and seedlings is lacking. We examined the effects of seed treatment with T. harzianum strain T22 on germination of seed exposed to biotic stress (seed and seedling disease caused by Pythium ultimum) and abiotic stresses (osmotic, salinity, chilling, or heat stress). We also evaluated the ability of the beneficial fungus to overcome physiological stress (poor seed quality induced by seed aging). If seed were not under any of the stresses noted above, T22 generally had little effect upon seedling performance. However, under stress, treated seed germinated consistently faster and more uniformly than untreated seeds whether the stress was osmotic, salt, or suboptimal temperatures. The consistent response to varying stresses suggests a common mechanism through which the plant-fungus association enhances tolerance to a wide range of abiotic stresses as well as biotic stress. A common factor that negatively affects plants under these stress conditions is accumulation of toxic reactive oxygen species (ROS), and we tested the hypothesis that T22 reduced damages resulting from accumulation of ROS in stressed plants. Treatment of seeds reduced accumulation of lipid peroxides in seedlings under osmotic stress or in aged seeds. In addition, we showed that the effect of exogenous application of an antioxidant, glutathione, or application of T22, resulted in a similar positive effect on seed germination under osmotic stress or in aged seed. This evidence supports the model that T. harzianum strain T22 increases seedling vigor and ameliorates stress by inducing physiological protection in plants against oxidative damage.

  10. Method for alleviating thermal stress damage in laminates. [metal matrix composites

    NASA Technical Reports Server (NTRS)

    Hoffman, C. A.; Weeton, J. W.; Orth, N. W. (Inventor)

    1980-01-01

    A method is provided for alleviating the stress damage in metallic matrix composites, such as laminated sheet or foil composites. Discontinuities are positively introduced into the interface between the layers so as to reduce the thermal stress produced by unequal expansion of the materials making up the composite. Although a number of discrete elements could be used to form one of the layers and thus carry out this purpose, the discontinuities are preferably produced by simply drilling holes in the metallic matrix layer or by forming grooves in a grid pattern in this layer.

  11. An ER-directed transcriptional response to unfolded protein stress in the absence of conserved sensor-transducer proteins in Giardia lamblia.

    PubMed

    Spycher, Cornelia; Herman, Emily K; Morf, Laura; Qi, Weihong; Rehrauer, Hubert; Aquino Fournier, Catharine; Dacks, Joel B; Hehl, Adrian B

    2013-05-01

    The protozoan Giardia lamblia has a minimized organelle repertoire, and most strikingly lacks a classical stacked Golgi apparatus. Nevertheless, Giardia trophozoites constitutively secrete variant surface proteins, and dramatically increase the volume of protein secretion during differentiation to cysts. Eukaryotic cells have evolved an elaborate system for quality control (QC) of protein folding and capacity in the endoplasmic reticulum (ER). Upon ER-overload, an unfolded protein response (UPR) is triggered on transcriptional/translational level aiming at alleviating ER stress. In Giardia, a minimized secretory machinery and absence of glycan-dependent QC suggests that a genetically conserved UPR (or functional equivalent) to cope with insults to the secretory system has been eliminated. We tested this hypothesis of UPR elimination by profiling the transcriptional response during induced ER-folding stress. We show that on the contrary, ER-folding stress triggers a stressor-specific, ER-directed response with upregulation of only ~ 30 genes, with different kinetics and scope compared with the UPR of other eukaryotes. Computational genomics revealed conserved cis-acting motifs in upstream regions of responder genes capable of stressor-specific gene regulation in transfected cells. Interestingly, the sensors/transducers of folding stress, well conserved in model eukaryotes, are absent in Giardia suggesting the presence of a novel version of this essential eukaryotic function. PMID:23617761

  12. Regulation of OSU-03012 toxicity by ER stress proteins and ER stress inducing drugs

    PubMed Central

    Booth, Laurence; Roberts, Jane L.; Cruickshanks, Nichola; Grant, Steven; Poklepovic, Andrew; Dent, Paul

    2014-01-01

    The present studies examined the toxic interaction between the non-coxib celecoxib derivative OSU-03012 and phosphodiesterase 5 (PDE5) inhibitors, and to determine the roles of endoplasmic reticulum stress response regulators in cell survival. PDE5 inhibitors interacted in a greater than additive fashion with OSU-03012 to kill parental glioma and stem-like glioma cells. Knock down of the endoplasmic reticulum stress response proteins IRE1 or XBP1 enhanced the lethality of OSU-03012, and of [OSU-03012 + PDE5 inhibitor] treatment. Pan-caspase and caspase 9 inhibition did not alter OSU-03012 lethality but did abolish enhanced killing in the absence of IRE1 or XBP1. Expression of the mitochondrial protective protein BCL-XL or the caspase 8 inhibitor c-FLIP-s, or knock down of death receptor CD95 or the death receptor – caspase 8 linker protein FADD, suppressed killing by [OSU-03012 + PDE5 inhibitor] treatment. CD95 activation was blocked by the nitric oxide synthase inhibitor L-NAME. Knock down of the autophagy regulatory proteins Beclin1 or ATG5 protected cells from OSU-03012 and of [OSU-03012 + PDE5 inhibitor] toxicity. Knock down of IRE1 enhanced OSU-03012/[OSU-03012 + PDE5 inhibitor] –induced JNK activation and inhibition of JNK suppressed the elevated killing caused by IRE1 knock down. Knock down of CD95 blunted JNK activation. Collectively our data demonstrates that PDE5 inhibitors recruit death receptor signaling to enhance OSU-03012 toxicity in GBM cells. PMID:25103559

  13. ER signaling is activated to protect human HaCaT keratinocytes from ER stress induced by environmental doses of UVB

    SciTech Connect

    Mera, Kentaro; Kawahara, Ko-ichi; Tada, Ko-ichi; Kawai, Kazuhiro; Hashiguchi, Teruto; Maruyama, Ikuro; Kanekura, Takuro

    2010-06-25

    Proteins are folded properly in the endoplasmic reticulum (ER). Various stress such as hypoxia, ischemia and starvation interfere with the ER function, causing ER stress, which is defined by the accumulation of unfolded protein (UP) in the ER. ER stress is prevented by the UP response (UPR) and ER-associated degradation (ERAD). These signaling pathways are activated by three major ER molecules, ATF6, IRE-1 and PERK. Using HaCaT cells, we investigated ER signaling in human keratinocytes irradiated by environmental doses of ultraviolet B (UVB). The expression of Ero1-L{alpha}, an upstream signaling molecule of ER stress, decreased at 1-4 h after 10 mJ/cm{sup 2} irradiation, indicating that the environmental dose of UVB-induced ER stress in HaCaT cells, without growth retardation. Furthermore, expression of intact ATF6 was decreased and it was translocated to the nuclei. The expression of XBP-1, a downstream molecule of IRE-1, which is an ER chaperone whose expression is regulated by XBP-1, and UP ubiquitination were induced by 10 mJ/cm{sup 2} UVB at 4 h. PERK, which regulates apoptosis, was not phosphorylated. Our results demonstrate that UVB irradiation generates UP in HaCaT cells and that the UPR and ERAD systems are activated to protect cells from UVB-induced ER stress. This is the first report to show ER signaling in UVB-irradiated keratinocytes.

  14. Endoplasmic reticulum ribosome-binding protein 1 (RRBP1) overexpression is frequently found in lung cancer patients and alleviates intracellular stress-induced apoptosis through the enhancement of GRP78.

    PubMed

    Tsai, H-Y; Yang, Y-F; Wu, A T; Yang, C-J; Liu, Y-P; Jan, Y-H; Lee, C-H; Hsiao, Y-W; Yeh, C-T; Shen, C-N; Lu, P-J; Huang, M-S; Hsiao, M

    2013-10-10

    Lung cancer is the leading cause of cancer deaths and is the most occurring malignancy worldwide. Unraveling the molecular mechanisms involved in lung tumorigenesis will greatly improve therapy. During early tumorigenesis, rapid proliferating tumor cells require increased activity of endoplasmic reticulum (ER) for protein synthesis, folding and secretion, thereby are subjected to ER stress. Ribosome-binding protein 1 (RRBP1) was originally identified as a ribosome-binding protein located on the rough ER and associated with unfolding protein response (UPR). In this report, we investigated the role of RRBP1 in lung cancer. RRBP1 was highly expressed in lung cancer tissue, as compared with adjacent normal tissues as assessed by immunohistochemistry (IHC) using lung cancer tissue array (n=87). Knockdown of RRBP1 by short-hairpin RNAs caused ER stress and significantly reduced cell viability and tumorigenicity. This effect was associated with a significant reduction in the expression of glucose-regulated protein 78 (GRP78). UPR regulator GRP78, an anti-apoptotic protein that is widely upregulated in cancer, has a critical role in chemotherapy resistance in some cancers. According to our results, cells with a higher level of RRBP1 were more resistant to ER stress. Ectopic expression of RRBP1 alleviated apoptosis that was induced by the ER-stress agent tunicamycin, 2-deoxy-D-glucose (2DG) or doxorubicin via enhancing GRP78 protein expression. A strong correlation was observed between the expression of RRBP1 and GRP78 in tumor biopsies using the database GSE10072. Our results also indicated that RRBP1 may involve in the regulation of mRNA stability of UPR components including ATF6 and GRP78. Taken together, RRBP1 could alleviate ER stress and help cancer cell survive. RRBP1 is critical for tumor cell survival, which may make it a useful target in lung cancer treatment and a candidate for the development of new targeted therapeutics.

  15. Sulforaphane prevents rat cardiomyocytes from hypoxia/reoxygenation injury in vitro via activating SIRT1 and subsequently inhibiting ER stress

    PubMed Central

    Li, Yun-peng; Wang, Shu-lin; Liu, Bei; Tang, Lu; Kuang, Rong-ren; Wang, Xian-bao; Zhao, Cong; Song, Xu-dong; Cao, Xue-ming; Wu, Xiang; Yang, Ping-zhen; Wang, Li-zi; Chen, Ai-hua

    2016-01-01

    Aim: Sulforaphane (SFN), a natural dietary isothiocyanate, is found to exert beneficial effects for cardiovascular diseases. This study aimed to investigate the mechanisms underlying the protective effects of SFN in a model of myocardial hypoxia/reoxygenation (H/R) injury in vitro. Methods: Cultured neonatal rat cardiomyocytes pretreated with SFN were subjected to 3-h hypoxia followed by 3-h reoxygenation. Cell viability and apoptosis were detected. Caspase-3 activity and mitochondrial membrane potential (ΔΨm) was measured. The expression of ER stress-related apoptotic proteins were analyzed with Western blot analyses. Silent information regulator 1 (SIRT1) activity was determined with SIRT1 deacetylase fluorometric assay kit. Results: SFN (0.1–5 μmol/L) dose-dependently improved the viability of cardiomyocytes, diminished apoptotic cells and suppressed caspase-3 activity. Meanwhile, SFN significantly alleviated the damage of ΔΨm and decreased the expression of ER stress-related apoptosis proteins (GRP78, CHOP and caspase-12), elevating the expression of SIRT1 and Bcl-2/Bax ratio in the cardiomyocytes. Co-treatment of the cardiomyocytes with the SIRT1-specific inhibitor Ex-527 (1 μmol/L) blocked the SFN-induced cardioprotective effects. Conclusion: SFN prevents cardiomyocytes from H/R injury in vitro most likely via activating SIRT1 pathway and subsequently inhibiting the ER stress-dependent apoptosis. PMID:26775664

  16. A novel role of c-FLIP protein in regulation of ER stress response.

    PubMed

    Conti, Silvia; Petrungaro, Simonetta; Marini, Elettra Sara; Masciarelli, Silvia; Tomaipitinca, Luana; Filippini, Antonio; Giampietri, Claudia; Ziparo, Elio

    2016-09-01

    Cellular-Flice-like inhibitory protein (c-FLIP) is an apoptosis modulator known to inhibit the extrinsic apoptotic pathway thus blocking Caspase-8 processing in the Death Inducing Signalling Complex (DISC). We previously demonstrated that c-FLIP localizes at the endoplasmic reticulum (ER) and that c-FLIP-deficient mouse embryonic fibroblasts (MEFs) display an enlarged ER morphology. In the present study, we have addressed the consequences of c-FLIP ablation in the ER stress response by investigating the effects of pharmacologically-induced ER stress in Wild Type (WT) and c-FLIP-/- MEFs. Surprisingly, c-FLIP-/- MEFs were found to be strikingly more resistant than WT MEFs to ER stress-mediated apoptosis. Analysis of Unfolded Protein Response (UPR) pathways revealed that Pancreatic ER Kinase (PERK) and Inositol-Requiring Enzyme 1 (IRE1) branch signalling is compromised in c-FLIP-/- cells when compared with WT cells. We found that c-FLIP modulates the PERK pathway by interfering with the activity of the serine threonine kinase AKT. Indeed, c-FLIP-/- MEFs display higher levels of active AKT than WT MEFs upon ER stress, while treatment with a specific AKT inhibitor of c-FLIP-/- MEFs subjected to ER stress restores the PERK but not the IRE1 pathway. Importantly, the AKT inhibitor or dominant negative AKT transfection sensitizes c-FLIP-/- cells to ER stress-induced cell death while the expression of a constitutively active AKT reduces WT cells sensitivity to ER stress-induced death. Thus, our results demonstrate that c-FLIP modulation of AKT activity is crucial in controlling PERK signalling and sensitivity to ER stress, and highlight c-FLIP as a novel molecular player in PERK and IRE1-mediated ER stress response.

  17. Initiation and execution of lipotoxic ER stress in pancreatic β-cells

    PubMed Central

    Cunha, Daniel A.; Hekerman, Paul; Ladrière, Laurence; Bazarra-Castro, Angie; Ortis, Fernanda; Wakeham, Marion C.; Moore, Fabrice; Rasschaert, Joanne; Cardozo, Alessandra K.; Bellomo, Elisa; Overbergh, Lutgart; Mathieu, Chantal; Lupi, Roberto; Hai, Tsonwin; Herchuelz, Andre; Marchetti, Piero; Rutter, Guy A.; Eizirik, Décio L.; Cnop, Miriam

    2013-01-01

    Summary Free fatty acids (FFA) cause apoptosis of pancreatic β-cells and might contribute to β-cell loss in type 2 diabetes via the induction of endoplasmic reticulum (ER) stress. We studied here the molecular mechanisms implicated in FFA-induced ER stress initiation and apoptosis in INS-1E cells, FACS-purified primary β-cells and human islets exposed to oleate and/or palmitate. Treatment with saturated and/or unsaturated FFA led to differential ER stress signaling. Palmitate induced more apoptosis and markedly activated the IRE1, PERK and ATF6 pathways, owing to a sustained depletion of ER Ca2+ stores, whereas the unsaturated FFA oleate led to milder PERK and IRE1 activation and comparable ATF6 signaling. Non-metabolizable methyl-FFA analogs induced neither ER stress nor β-cell apoptosis. The FFA-induced ER stress response was not modified by high glucose concentrations, suggesting that ER stress in primary β-cells is primarily lipotoxic, and not glucolipotoxic. Palmitate, but not oleate, activated JNK. JNK inhibitors reduced palmitate-mediated AP-1 activation and apoptosis. Blocking the transcription factor CHOP delayed palmitate-induced β-cell apoptosis. In conclusion, saturated FFA induce ER stress via ER Ca2+ depletion. The IRE1 and resulting JNK activation contribute to β-cell apoptosis. PERK activation by palmitate also contributes to β-cell apoptosis via CHOP. PMID:18559892

  18. Roles of meditation on alleviation of oxidative stress and improvement of antioxidant system.

    PubMed

    Mahagita, Chitrawina

    2010-11-01

    According to MEDLINE/Pubmed search to December 2009, the modulation effects of meditation on oxidative stress have been increasingly investigated for acute, short and long-term effects. Both invasive and noninvasive measurements have been utilized. Long-term transcendental and Zen meditators have been showed to diminish oxidative stress seen by a reduction of lipid peroxidation and biophoton emission. Glutathione level and activity of antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase) have been facilitated in Yoga and Sudarshan Kriya practitioners. One year of Tai Chi training has been reported to promote superoxide dismutase activity and lessen lipid peroxidation. Performing diaphragmatic breathing after exhaustive exercise has attenuated oxidative stress faster than control. These data suggest possible roles of meditation and meditation-based techniques on the decrease of oxidative stress which may assist to prevent and/or alleviate deterioration of related diseases. However, further research needs to elucidate the cellular and molecular mechanisms which remain challenge to accomplish.

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

    PubMed Central

    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

  20. Mechanisms of silicon-mediated alleviation of drought and salt stress in plants: a review.

    PubMed

    Rizwan, Muhammad; Ali, Shafaqat; Ibrahim, Muhammad; Farid, Mujahid; Adrees, Muhammad; Bharwana, Saima Aslam; Zia-Ur-Rehman, Muhammad; Qayyum, Muhammad Farooq; Abbas, Farhat

    2015-10-01

    Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na(+) uptake and translocation while increased K(+) uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils.

  1. Mechanisms of silicon-mediated alleviation of drought and salt stress in plants: a review.

    PubMed

    Rizwan, Muhammad; Ali, Shafaqat; Ibrahim, Muhammad; Farid, Mujahid; Adrees, Muhammad; Bharwana, Saima Aslam; Zia-Ur-Rehman, Muhammad; Qayyum, Muhammad Farooq; Abbas, Farhat

    2015-10-01

    Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na(+) uptake and translocation while increased K(+) uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils. PMID:26335528

  2. Dietary Astragalus polysaccharide alleviated immunological stress in broilers exposed to lipopolysaccharide.

    PubMed

    Liu, Lei; Shen, Jing; Zhao, Chao; Wang, Xiaofei; Yao, Junhu; Gong, Yuesheng; Yang, Xiaojun

    2015-01-01

    This study was conducted to investigate whether dietary Astragalus polysaccharide (APS) could alleviate immunological stress response of chickens after challenge with lipopolysaccharide (LPS). A total of 360 one-day-old commercial Arbor Acres broilers were randomly assigned in a 2 × 2 factorial design. The main factors were immunological stress (LPS or saline) and dietary APS (0 or 3g APS/kg feed). At 12, 14, 33 and 35 days of age, chickens were injected intramuscularly with either 500 μg/kg body weight of LPS or sterile saline. The results showed that the decreased daily feed intake and daily weight gain caused by immunological stress were dramatically attenuated by APS supplementation. The LPS challenge led to an increased mRNA abundance of TLR4, NF-κB, IL-1β, IL-6, avian uncoupling protein, α1-acid glycoprotein, hemopexin and y(+)LAT2. However, these negative effects of the LPS administration were ameliorated by APS supplementation. Moreover, dietary APS inhibited the LPS-induced depression of amino acid digestibilities. In conclusion, APS is able to alleviate LPS-induced immunological stress response in chickens. The beneficial effect may be attributed to suppressing the expression of pro-inflammatory cytokines through reducing the TLR4 and NF-κB genes transcription, and therewith improving energy and protein metabolism. PMID:25239195

  3. Dietary Astragalus polysaccharide alleviated immunological stress in broilers exposed to lipopolysaccharide.

    PubMed

    Liu, Lei; Shen, Jing; Zhao, Chao; Wang, Xiaofei; Yao, Junhu; Gong, Yuesheng; Yang, Xiaojun

    2015-01-01

    This study was conducted to investigate whether dietary Astragalus polysaccharide (APS) could alleviate immunological stress response of chickens after challenge with lipopolysaccharide (LPS). A total of 360 one-day-old commercial Arbor Acres broilers were randomly assigned in a 2 × 2 factorial design. The main factors were immunological stress (LPS or saline) and dietary APS (0 or 3g APS/kg feed). At 12, 14, 33 and 35 days of age, chickens were injected intramuscularly with either 500 μg/kg body weight of LPS or sterile saline. The results showed that the decreased daily feed intake and daily weight gain caused by immunological stress were dramatically attenuated by APS supplementation. The LPS challenge led to an increased mRNA abundance of TLR4, NF-κB, IL-1β, IL-6, avian uncoupling protein, α1-acid glycoprotein, hemopexin and y(+)LAT2. However, these negative effects of the LPS administration were ameliorated by APS supplementation. Moreover, dietary APS inhibited the LPS-induced depression of amino acid digestibilities. In conclusion, APS is able to alleviate LPS-induced immunological stress response in chickens. The beneficial effect may be attributed to suppressing the expression of pro-inflammatory cytokines through reducing the TLR4 and NF-κB genes transcription, and therewith improving energy and protein metabolism.

  4. Brassinosteroid alleviates polychlorinated biphenyls-induced oxidative stress by enhancing antioxidant enzymes activity in tomato.

    PubMed

    Ahammed, Golam Jalal; Ruan, Yi-Ping; Zhou, Jie; Xia, Xiao-Jian; Shi, Kai; Zhou, Yan-Hong; Yu, Jing-Quan

    2013-03-01

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants often found in the atmosphere. Phytoremediation of airborne PCBs is an emerging new concept to minimize potential human exposure. However, effects of atmospheric PCBs on plant growth, photosynthesis and antioxidant defence system are poorly understood area. Brassinosteroids have been reported to alleviate different abiotic stresses including organic pollutants-induced stress. Hence, we studied the effects of PCBs and 24-epibrassinolide (EBR) on biomass accumulation, photosynthetic machinery and antioxidant system in tomato plants. PCBs (0.4, 2.0 and 10 μg/l) mist spray significantly decreased dry weight, photosynthesis, chlorophyll contents in a dose dependent manner. Both stomatal and non-stomatal factors were involved in PCBs-induced photosynthetic inhibition. Likewise, the maximal photochemical efficiency of PSII (Fv/Fm), the quantum efficiency of PSII photochemistry (Φ(PSII)) and photochemical quenching coefficient were increasingly decreased by various levels of PCBs, suggesting an induction of photoinhibition. Increased accumulation of H(2)O(2) and O(2)(-) accompanied with high lipid peroxidation confirmed occurrence of oxidative stress upon PCBs exposure. Meanwhile, antioxidant enzymes activity was decreased following exposure to PCBs. Foliar application of EBR (100 nM) increased biomass, photosynthetic capacity, chlorophyll contents and alleviated photoinhibition by enhancing Fv/Fm, Φ(PSII) and qP. EBR significantly decreased harmful ROS accumulation and lipid peroxidation through the induction of antioxidant enzymes activity. Our results suggest a protective role of EBR against PCBs stress which may strengthen phytoremediation approaches by enhancing plant tolerance.

  5. Potassium nitrate application alleviates sodium chloride stress in winter wheat cultivars differing in salt tolerance.

    PubMed

    Zheng, Yanhai; Jia, Aijun; Ning, Tangyuan; Xu, Jialin; Li, Zengjia; Jiang, Gaoming

    2008-09-29

    A sand culture experiment was conducted to answer the question whether or not exogenous KNO(3) can alleviate adverse effects of salt stress in winter wheat by monitoring plant growth, K(+)/Na(+) accumulation and the activity of some antioxidant enzymes. Seeds of two wheat cultivars (CVs), DK961 (salt-tolerant) and JN17 (salt-sensitive), were planted in sandboxes and controls germinated and raised with Hoagland nutrient solution (6 mM KNO(3), no NaCl). Experimental seeds were exposed to seven modified Hoagland solutions containing increased levels of KNO(3) (11, 16, 21 mM) or 100 mM NaCl in combination with the four KNO(3) concentrations (6, 11, 16 and 21 mM). Plants were harvested 30 d after imbibition, with controls approximately 22 cm in height. Both CVs showed significant reduction in plant height, root length and dry weight of shoots and roots under KNO(3) or NaCl stress. However, the combination of increased KNO(3) and NaCl alleviated symptoms of the individual salt stresses by improving growth of shoots and roots, reducing electrolyte leakage, malondialdehyde and soluble sugar contents and enhancing the activities of antioxidant enzymes. The salt-tolerant cultivar accumulated more K(+) in both shoots and roots compared with the higher Na(+) accumulation typical for the salt-sensitive cultivar. Soluble sugar content and activities of antioxidant enzymes were found to be more stable in the salt-tolerant cultivar. Our findings suggest that the optimal K(+)/Na(+) ratio of the nutrient solution should be 16:100 for both the salt-tolerant and the salt-sensitive cultivar under the experimental conditions used, and that the alleviation of NaCl stress symptoms through simultaneously applied elevated KNO(3) was more effective in the salt-tolerant than in the salt-sensitive cultivar.

  6. AMPK-independent inhibition of human macrophage ER stress response by AICAR

    PubMed Central

    Boß, Marcel; Newbatt, Yvette; Gupta, Sahil; Collins, Ian; Brüne, Bernhard; Namgaladze, Dmitry

    2016-01-01

    Obesity-associated insulin resistance is driven by inflammatory processes in response to metabolic overload. Obesity-associated inflammation can be recapitulated in cell culture by exposing macrophages to saturated fatty acids (SFA), and endoplasmic reticulum (ER) stress responses essentially contribute to pro-inflammatory signalling. AMP-activated protein kinase (AMPK) is a central metabolic regulator with established anti-inflammatory actions. Whether pharmacological AMPK activation suppresses SFA-induced inflammation in a human system is unclear. In a setting of hypoxia-potentiated inflammation induced by SFA palmitate, we found that the AMP-mimetic AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) potently suppressed upregulation of ER stress marker mRNAs and pro-inflammatory cytokines. Furthermore, AICAR inhibited macrophage ER stress responses triggered by ER-stressors thapsigargin or tunicamycin. Surprisingly, AICAR acted independent of AMPK or AICAR conversion to 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl monophosphate (ZMP) while requiring intracellular uptake via the equilibrative nucleoside transporter (ENT) ENT1 or the concentrative nucleoside transporter (CNT) CNT3. AICAR did not affect the initiation of the ER stress response, but inhibited the expression of major ER stress transcriptional effectors. Furthermore, AICAR inhibited autophosphorylation of the ER stress sensor inositol-requiring enzyme 1α (IRE1α), while activating its endoribonuclease activity in vitro. Our results suggest that AMPK-independent inhibition of ER stress responses contributes to anti-inflammatory and anti-diabetic effects of AICAR. PMID:27562249

  7. AMPK-independent inhibition of human macrophage ER stress response by AICAR.

    PubMed

    Boß, Marcel; Newbatt, Yvette; Gupta, Sahil; Collins, Ian; Brüne, Bernhard; Namgaladze, Dmitry

    2016-01-01

    Obesity-associated insulin resistance is driven by inflammatory processes in response to metabolic overload. Obesity-associated inflammation can be recapitulated in cell culture by exposing macrophages to saturated fatty acids (SFA), and endoplasmic reticulum (ER) stress responses essentially contribute to pro-inflammatory signalling. AMP-activated protein kinase (AMPK) is a central metabolic regulator with established anti-inflammatory actions. Whether pharmacological AMPK activation suppresses SFA-induced inflammation in a human system is unclear. In a setting of hypoxia-potentiated inflammation induced by SFA palmitate, we found that the AMP-mimetic AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) potently suppressed upregulation of ER stress marker mRNAs and pro-inflammatory cytokines. Furthermore, AICAR inhibited macrophage ER stress responses triggered by ER-stressors thapsigargin or tunicamycin. Surprisingly, AICAR acted independent of AMPK or AICAR conversion to 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl monophosphate (ZMP) while requiring intracellular uptake via the equilibrative nucleoside transporter (ENT) ENT1 or the concentrative nucleoside transporter (CNT) CNT3. AICAR did not affect the initiation of the ER stress response, but inhibited the expression of major ER stress transcriptional effectors. Furthermore, AICAR inhibited autophosphorylation of the ER stress sensor inositol-requiring enzyme 1α (IRE1α), while activating its endoribonuclease activity in vitro. Our results suggest that AMPK-independent inhibition of ER stress responses contributes to anti-inflammatory and anti-diabetic effects of AICAR. PMID:27562249

  8. PUMA mediates ER stress-induced apoptosis in portal hypertensive gastropathy.

    PubMed

    Tan, S; Wei, X; Song, M; Tao, J; Yang, Y; Khatoon, S; Liu, H; Jiang, J; Wu, B

    2014-03-13

    Mucosal apoptosis has been demonstrated to be an essential pathological feature in portal hypertensive gastropathy (PHG). p53-upregulated modulator of apoptosis (PUMA) was identified as a BH3-only Bcl-2 family protein that has an essential role in apoptosis induced by a variety of stimuli, including endoplasmic reticulum (ER) stress. However, whether PUMA is involved in mucosal apoptosis in PHG remains unclear, and whether PUMA induces PHG by mediating ER stress remains unknown. The aim of the study is to investigate whether PUMA is involved in PHG by mediating ER stress apoptotic signaling. To identify whether PUMA is involved in PHG by mediating ER stress, gastric mucosal injury and apoptosis were studied in both PHG patients and PHG animal models using PUMA knockout (PUMA-KO) and PUMA wild-type (PUMA-WT) mice. The induction of PUMA expression and ER stress signaling were investigated, and the mechanisms of PUMA-mediated apoptosis were analyzed. GES-1 and SGC7901 cell lines were used to further identify whether PUMA-mediated apoptosis was induced by ER stress in vitro. Epithelial apoptosis and PUMA were markedly induced in the gastric mucosa of PHG patients and mouse PHG models. ER stress had a potent role in the induction of PUMA and apoptosis in PHG models, and the apoptosis was obviously attenuated in PUMA-KO mice. Although the targeted deletion of PUMA did not affect ER stress, mitochondrial apoptotic signaling was downregulated in mice. Meanwhile, PUMA knockdown significantly ameliorated ER stress-induced mitochondria-dependent apoptosis in vitro. These results indicate that PUMA mediates ER stress-induced mucosal epithelial apoptosis through the mitochondrial apoptotic pathway in PHG, and that PUMA is a potentially therapeutic target for PHG.

  9. Kinetin applications alleviate salt stress and improve the antioxidant composition of leaf extracts in Salvia officinalis.

    PubMed

    Tounekti, Taïeb; Hernández, Iker; Müller, Maren; Khemira, Habib; Munné-Bosch, Sergi

    2011-10-01

    A pot experiment was carried out under glasshouse conditions with common sage (Salvia officinalis L.) to investigate the interactive effects of salt stress and kinetin on growth attributes and the abundance of pigments, ions, phenolic diterpenes and α-tocopherol in leaf extracts of this species. The plants were subjected to the following four treatments: (i) control (nutrient solution), (ii) control + 10 μM kinetin, (iii) salt stress (nutrient solution + 100 mM NaCl), and (iv) salt stress + 10 μM kinetin. Kinetin was applied as a foliar fertilizer. Salt stress reduced water contents, photosynthetic activity and pigment contents of sage leaves. In addition, it increased Na(+) contents, and reduced those of Ca(2+) and K(+) in leaves. Salt stress reduced carnosic acid and 12-O-methyl carnosic acid contents in leaves, while it did not affect carnosol and α-tocopherol contents. Foliar applications of kinetin seemed to counterbalance or alleviate the stress symptoms induced by salinity, improving ion and pigment contents, while leaf phenolic diterpene (mainly carnosol) and α-tocopherol contents also increased in both control and NaCl-treated plants; still this effect was much more obvious in salt-treated plants. A similar effect was also obtained when plants were sprayed with KNO(3) or Ca(NO(3))(2), thus suggesting that kinetin effects were at least partly due to an improvement of ion homeostasis. Kinetin applications resulted in increased transcript levels of the isoprenoid and tocopherol biosynthetic genes, DXPRI and VTE2 and VTE4 in control plants, but not in NaCl-treated plants. We conclude that kinetin can alleviate the negative impact of salt on sage plants cultivated under arid environments with salinity problems.

  10. Kinetin applications alleviate salt stress and improve the antioxidant composition of leaf extracts in Salvia officinalis.

    PubMed

    Tounekti, Taïeb; Hernández, Iker; Müller, Maren; Khemira, Habib; Munné-Bosch, Sergi

    2011-10-01

    A pot experiment was carried out under glasshouse conditions with common sage (Salvia officinalis L.) to investigate the interactive effects of salt stress and kinetin on growth attributes and the abundance of pigments, ions, phenolic diterpenes and α-tocopherol in leaf extracts of this species. The plants were subjected to the following four treatments: (i) control (nutrient solution), (ii) control + 10 μM kinetin, (iii) salt stress (nutrient solution + 100 mM NaCl), and (iv) salt stress + 10 μM kinetin. Kinetin was applied as a foliar fertilizer. Salt stress reduced water contents, photosynthetic activity and pigment contents of sage leaves. In addition, it increased Na(+) contents, and reduced those of Ca(2+) and K(+) in leaves. Salt stress reduced carnosic acid and 12-O-methyl carnosic acid contents in leaves, while it did not affect carnosol and α-tocopherol contents. Foliar applications of kinetin seemed to counterbalance or alleviate the stress symptoms induced by salinity, improving ion and pigment contents, while leaf phenolic diterpene (mainly carnosol) and α-tocopherol contents also increased in both control and NaCl-treated plants; still this effect was much more obvious in salt-treated plants. A similar effect was also obtained when plants were sprayed with KNO(3) or Ca(NO(3))(2), thus suggesting that kinetin effects were at least partly due to an improvement of ion homeostasis. Kinetin applications resulted in increased transcript levels of the isoprenoid and tocopherol biosynthetic genes, DXPRI and VTE2 and VTE4 in control plants, but not in NaCl-treated plants. We conclude that kinetin can alleviate the negative impact of salt on sage plants cultivated under arid environments with salinity problems. PMID:21856165

  11. Selenium alleviates chromium toxicity by preventing oxidative stress in cabbage (Brassica campestris L. ssp. Pekinensis) leaves.

    PubMed

    Qing, Xuejiao; Zhao, Xiaohu; Hu, Chengxiao; Wang, Peng; Zhang, Ying; Zhang, Xuan; Wang, Pengcheng; Shi, Hanzhi; Jia, Fen; Qu, Chanjuan

    2015-04-01

    The beneficial role of selenium (Se) in alleviation of chromium (Cr)-induced oxidative stress is well established. However, little is known about the underlying mechanism. The impacts of exogenous Se (0.1mg/L) on Cr(1mg/L)-induced oxidative stress and antioxidant systems in leaves of cabbage (Brassica campestris L. ssp. Pekinensis) were investigated by using cellular and biochemical approaches. The results showed that supplementation of the medium with Se was effective in reducing Cr-induced increased levels of lipid peroxides and superoxide free radicals (O(-)2(·)), as well as increasing activities of superoxide dismutase (SOD) and peroxidase (POD). Meanwhile, 1mg/L Cr induced loss of plasma membrane integrity, growth inhibition, as well as ultrastructural changes of leaves were significantly reversed due to Se supplementation in the medium. In addition, Se application significantly altered the subcellular distribution of Cr which transported from mitochondria, nucleus and the cell-wall material to the soluble fraction and chloroplasts. However, Se application did no significant alteration of Cr effects on osmotic adjustment accumulating products. The study suggested that Se is able to protect leaves of cabbage against Cr toxicity by alleviation of Cr induced oxidative stress, and re-distribution of Cr in the subcellular of the leaf. Furthermore, free radicals, lipid peroxides, activity of SOD and POD, and subcellular distribution of Cr can be considered the efficient biomarkers to indicate the efficiency of Se to detoxification Cr.

  12. Role of Ulva lactuca Extract in Alleviation of Salinity Stress on Wheat Seedlings

    PubMed Central

    Ibrahim, Wael M.; Ali, Refaat M.; Hemida, Khaulood A.; Sayed, Makram A.

    2014-01-01

    Seaweeds are potentially excellent sources of highly bioactive materials that could represent useful leads in the alleviation of salinity stress. The effects of presoaking wheat grains in water extract of Ulva lactuca on growth, some enzymatic activities, and protein pattern of salinized plants were investigated in this study. Algal presoaking of grains demonstrated a highly significant enhancement in the percentage of seed germination and growth parameters. The activity of superoxide dismutase (SOD) and catalase (CAT) increased with increasing the algal extract concentration while activity of ascorbate peroxidase (APX) and glutathione reductase (GR) was decreased with increasing concentration of algal extract more than 1% (w/v). The protein pattern of wheat seedling showed 12 newly formed bands as result of algal extract treatments compared with control. The bioactive components in U. lactuca extract such as ascorbic acid, betaine, glutathione, and proline could potentially participate in the alleviation of salinity stress. Therefore, algal presoaking is proved to be an effective technique to improve the growth of wheat seedlings under salt stress conditions. PMID:25436231

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

    PubMed

    Sato, Amy Y; Tu, Xiaolin; McAndrews, Kevin A; Plotkin, Lilian I; Bellido, Teresita

    2015-04-01

    Endoplasmic reticulum (ER) stress is associated with increased reactive oxygen species (ROS), results from accumulation of misfolded/unfolded proteins, and can trigger apoptosis. ER stress is alleviated by phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), which inhibits protein translation allowing the ER to recover, thus promoting cell viability. We investigated whether osteoblastic cell apoptosis induced by glucocorticoids (GCs) is due to induction of ROS/ER stress and whether inhibition of eIF2α dephosphorylation promotes survival opposing the deleterious effects of GC in vitro and in vivo. Apoptosis of osteocytic MLO-Y4 and osteoblastic OB-6 cells induced by dexamethasone was abolished by ROS inhibitors. Like GC, the ER stress inducing agents brefeldin A and tunicamycin induced osteoblastic cell apoptosis. Salubrinal or guanabenz, specific inhibitors of eIF2α dephosphorylation, blocked apoptosis induced by either GC or ER stress inducers. Moreover, GC markedly decreased mineralization in OB-6 cells or primary osteoblasts; and salubrinal or guanabenz increased mineralization and prevented the inhibitory effect of GC. Furthermore, salubrinal (1 mg/kg/day) abolished osteoblast and osteocyte apoptosis in cancellous and cortical bone and partially prevented the loss of BMD at all sites and the decreased vertebral cancellous bone formation induced by treatment with prednisolone for 28 days (1.4 mg/kg/day). We conclude that part of the pro-apoptotic actions of GC on osteoblastic cells is mediated through ER stress, and that inhibition of eIF2α dephosphorylation protects from GC-induced apoptosis of osteoblasts and osteocytes in vitro and in vivo and from the deleterious effects of GC on the skeleton. PMID:25532480

  14. Arbuscular mycorrhizal symbiosis influences strigolactone production under salinity and alleviates salt stress in lettuce plants.

    PubMed

    Aroca, Ricardo; Ruiz-Lozano, Juan Manuel; Zamarreño, Angel María; Paz, José Antonio; García-Mina, José María; Pozo, María José; López-Ráez, Juan Antonio

    2013-01-01

    Arbuscular mycorrhizal (AM) symbiosis can alleviate salt stress in plants. However the intimate mechanisms involved, as well as the effect of salinity on the production of signalling molecules associated to the host plant-AM fungus interaction remains largely unknown. In the present work, we have investigated the effects of salinity on lettuce plant performance and production of strigolactones, and assessed its influence on mycorrhizal root colonization. Three different salt concentrations were applied to mycorrhizal and non-mycorrhizal plants, and their effects, over time, analyzed. Plant biomass, stomatal conductance, efficiency of photosystem II, as well as ABA content and strigolactone production were assessed. The expression of ABA biosynthesis genes was also analyzed. AM plants showed improved growth rates and a better performance of physiological parameters such as stomatal conductance and efficiency of photosystem II than non-mycorrhizal plants under salt stress since very early stages - 3 weeks - of plant colonization. Moreover, ABA levels were lower in those plants, suggesting that they were less stressed than non-colonized plants. On the other hand, we show that both AM symbiosis and salinity influence strigolactone production, although in a different way in AM and non-AM plants. The results suggest that AM symbiosis alleviates salt stress by altering the hormonal profiles and affecting plant physiology in the host plant. Moreover, a correlation between strigolactone production, ABA content, AM root colonization and salinity level is shown. We propose here that under these unfavourable conditions, plants increase strigolactone production in order to promote symbiosis establishment to cope with salt stress.

  15. Alleviation of drought stress of marigold (Tagetes erecta) plants by using arbuscular mycorrhizal fungi.

    PubMed

    Asrar, Abdul-Wasea A; Elhindi, Khalid M

    2011-01-01

    The effect of an arbuscular mycorrhizal fungus "AMF" (Glomus constrictum Trappe) on growth, pigments, and phosphorous content of marigold (Tagetes erecta) plant grown under different levels of drought stress was investigated. The applied drought stress levels reduced growth vigor (i.e. plant height, shoot dry weight, flower diameter as well as its fresh and dry weights) of mycorrhizal and non-mycorrhizal plant as compared to control plant (non-drought stressed plant). The presence of mycorrhizal fungus, however, stimulated all growth parameters of the treated plant comparing to non-mycorrhizal treated plant. The photosynthetic pigments (carotene in flowers and chlorophylls a and b in leaves) were also stimulated by the mycorrhizal fungi of well-watered as well as of water-stressed plants. The total pigments of mycorrhizal plants grown under well-watered conditions were higher than those of non-mycorrhizal ones by 60%. In most cases, drought-stressed mycorrhizal plants were significantly better than those of the non-mycorrhizal plants. So, the overall results suggest that mycorrhizal fungal colonization affects host plant positively on growth, pigments, and phosphorous content, flower quality and thereby alleviates the stress imposed by water with holding. PMID:23961109

  16. Nitrogen availability regulates proline and ethylene production and alleviates salinity stress in mustard (Brassica juncea).

    PubMed

    Iqbal, Noushina; Umar, Shahid; Khan, Nafees A

    2015-04-15

    Proline content and ethylene production have been shown to be involved in salt tolerance mechanisms in plants. To assess the role of nitrogen (N) in the protection of photosynthesis under salt stress, the effect of N (0, 5, 10, 20 mM) on proline and ethylene was studied in mustard (Brassica juncea). Sufficient N (10 mM) optimized proline production under non-saline conditions through an increase in proline-metabolizing enzymes, leading to osmotic balance and protection of photosynthesis through optimal ethylene production. Excess N (20 mM), in the absence of salt stress, inhibited photosynthesis and caused higher ethylene evolution but lower proline production compared to sufficient N. In contrast, under salt stress with an increased demand for N, excess N optimized ethylene production, which regulates the proline content resulting in recovered photosynthesis. The effect of excess N on photosynthesis under salt stress was further substantiated by the application of the ethylene biosynthesis inhibitor, 1-aminoethoxy vinylglycine (AVG), which inhibited proline production and photosynthesis. Without salt stress, AVG promoted photosynthesis in plants receiving excess N by inhibiting stress ethylene production. The results suggest that a regulatory interaction exists between ethylene, proline and N for salt tolerance. Nitrogen differentially regulates proline production and ethylene formation to alleviate the adverse effect of salinity on photosynthesis in mustard.

  17. Alleviating versus stimulating effects of bicarbonate on the growth of Vallisneria natans under ammonia stress.

    PubMed

    Dou, Yanyan; Wang, Baozhong; Chen, Liangyan; Yin, Daqiang

    2013-08-01

    Bicarbonate plays a crucial role in limiting the growth of submersed aquatic macrophytes in eutrophic lakes, and high ammonia is often toxic to macrophytes. In order to evaluate the combined effect of HCO3 (-) and total ammonia (i.e., the total of NH3 and NH4 (+)) on submersed macrophytes Vallisneria natans, the growth and physiological response of V. natans in the presence of HCO3 (-) and ammonia were studied. The results showed that with the increase of ammonia, morphological parameters of V. natans declined. In contrast, increased HCO3 (-) concentration stimulated the growth of V. natans, especially when the NH4 (+)-N/NO3 (-)-N ratio was 1:7. High ammonia concentration induced excess free amino acids (FAA) accumulation and soluble carbohydrates (SC) depletion in plant tissues. However, the elevated HCO3 (-) promoted the synthesis of SC and rendered the decrease of FAA/SC ratio. The results also suggested that HCO3 (-) could partially alleviate the stress of ammonia, as evidenced by the decrease of FAA/SC ratio and the growth enhancement of V. natans when the ammonia concentration was 0.58 mg L(-1). Given the fact that HCO3 (-) is probably the dominant available carbon source in most eutrophic lakes, the ability of V. natans to use HCO3 (-) for SC synthesis may explain the alleviating effect of HCO3 (-) on V. natans under ammonia stress. PMID:23381797

  18. Elevated CO2 alleviates high PAR and UV stress in the unicellular chlorophyte Dunaliella tertiolecta.

    PubMed

    García-Gómez, Candela; Gordillo, Francisco J L; Palma, Armando; Lorenzo, M Rosario; Segovia, María

    2014-09-01

    The effects of increased CO2 and irradiance on the physiological performance of the chlorophyte Dunaliella tertiolecta were studied at different PAR and UVR (UVA + UVB) irradiances, simulating the solar radiation at different depths, at present (390 ppmv, LC) and predicted CO2 levels for the year 2100 (1000 ppmv, HC). Elevated CO2 resulted in higher optimum and effective quantum yields (F(v)/F(m) and ϕPSII, respectively), electron transport rates (ETR) and specific growth rates (μ). Cell stress was alleviated in HC with respect to LC as evidenced by a decrease in reactive oxygen species (ROS) accumulation. DNA damage showed a 42-fold increase in cyclobutane-pyrimidine dimer (CPD) formation under the highest irradiance (1100 μmol quanta m(-2) s(-1)) in LC with respect to the lowest irradiance (200 μmol quanta m(-2) s(-1)). Photolyase (CII-PCD-PL) gene expression was upregulated under HC resulting in a drastic decrease in CPD accumulation to only 25% with respect to LC. Proliferating cell nuclear antigen (PCNA) accumulation was always higher in HC and the accumulation pattern indicated its involvement in repair or growth depending on the irradiance dose. The repressor of silencing (ROS1) was only marginally involved in the response, suggesting that photoreactivation was the most relevant mechanism to overcome UVR damage. Our results demonstrate that future scenarios of global change result in alleviation of irradiance stress by CO2-induced photoprotection in D. tertiolecta.

  19. Dietary chromium methionine supplementation could alleviate immunosuppressive effects of heat stress in broiler chicks.

    PubMed

    Jahanian, R; Rasouli, E

    2015-07-01

    circulation. Supplementation of CrMet to heat-stressed chicks modulated (P < 0.01) plasma corticosterone level. The present findings indicate that dietary CrMet supplementation could alleviate heat-stress-induced growth retardation in broiler chicks. Moreover, supplemental CrMet modulated suppressive effects of heat stress on cellular and humoral immune responses.

  20. Verminoside mediates life span extension and alleviates stress in Caenorhabditis elegans.

    PubMed

    Pant, A; Asthana, J; Yadav, A K; Rathor, L; Srivastava, S; Gupta, M M; Pandey, R

    2015-01-01

    The discovery of bioactive molecules modulating aging in living organism promotes development of natural therapeutics for curing age-related afflictions. The progression in age-related disorders can be attributed to increment in intracellular reactive oxygen species (ROS) and oxidative stress level. To this end, we isolated an iridoid verminoside (VMS) from Stereospermum suaveolens (Roxb.) DC. and evaluated its effect on Caenorhabditis elegans. The present study delineates VMS-mediated alteration of intracellular ROS, oxidative stress, and life span in C. elegans. The different tested doses of VMS (5 μM, 25 μM, and 50 μM) were able to enhance ROS scavenging and extend mean life span in C. elegans. The maximal life span extension was observed in 25 μM VMS, that is, 20.79% (P < 0.0001) followed by 9.84% (P < 0.0001) in 5 μM VMS and 8.54% (P < 0.0001) in 50 μM VMS. VMS was able to alleviate juglone-induced oxidative stress and enhanced thermotolerance in worms. The stress-modulating and ROS-scavenging potential of VMS was validated by increment in mean survival by 29.54% (P < 0.0001) in VMS-treated oxidative stress hypersensitive mev-1 mutant strain. Furthermore, VMS modulates expression of DAF-16 (a FoxO transcription factor) promoting stress resistance and longevity. Altogether, our results suggest that VMS attenuates intracellular ROS and stress (oxidative and thermal) level promoting longevity. The longevity and stress modulation can be attributed to VMS-mediated alterations in daf-16 expression which regulates insulin signaling pathway. This study opens doors for development of phytomolecule-based therapeutics for prolonging life span and managing age-related severe disorders.

  1. Aortic ER stress in streptozotocin-induced diabetes mellitus in APA hamsters.

    PubMed

    Kurokawa, Masaki; Hideshima, Makoto; Ishii, Yoshiyuki; Kyuwa, Shigeru; Yoshikawa, Yasuhiro

    2009-04-01

    Atherosclerosis is thought to be associated with endoplasmic reticulum (ER) dysfunction and the accumulation of unfolded proteins. In this study, we examined the relationship between atherosclerosis and ER stress and the effect of sodium 4-phenylbutyrate (4-PBA), a kind of chemical chaperone, on atherosclerosis in streptozotocin-induced diabetic APA hamsters. Male, 8-week-old, APA hamsters were injected with streptozotocin (30 mg/kg body weight) to induce diabetes mellitus, and ER stress was evaluated immunohistochemically or by semi-quantitative RT-PCR analysis using ER stress markers such as calreticulin and GPR78. Control hamsters were injected with citrate buffer and were similarly analyzed. In the aorta of control animals, a weak ER stress was detected, and 4-PBA treatment decreased the calreticulin- and GRP78-positive areas and also reduced the mRNA levels of calreticulin and GRP78. On the other hand, strong ER stress was detected at the lesser curvature of the aortic arch of streptozotocin-induced diabetic APA hamsters. However, 4-PBA treatment failed to lessen the ER stress in the aorta and had no effect on improvement of the atherosclerotic lesions. These results may provide an explanation for the complex etiology of atherosclerosis accompanied by diabetes mellitus and various other clinical phenotypes of atherosclerosis.

  2. NOD1 and NOD2 signalling links ER stress with inflammation.

    PubMed

    Keestra-Gounder, A Marijke; Byndloss, Mariana X; Seyffert, Núbia; Young, Briana M; Chávez-Arroyo, Alfredo; Tsai, April Y; Cevallos, Stephanie A; Winter, Maria G; Pham, Oanh H; Tiffany, Connor R; de Jong, Maarten F; Kerrinnes, Tobias; Ravindran, Resmi; Luciw, Paul A; McSorley, Stephen J; Bäumler, Andreas J; Tsolis, Renée M

    2016-04-21

    Endoplasmic reticulum (ER) stress is a major contributor to inflammatory diseases, such as Crohn disease and type 2 diabetes. ER stress induces the unfolded protein response, which involves activation of three transmembrane receptors, ATF6, PERK and IRE1α. Once activated, IRE1α recruits TRAF2 to the ER membrane to initiate inflammatory responses via the NF-κB pathway. Inflammation is commonly triggered when pattern recognition receptors (PRRs), such as Toll-like receptors or nucleotide-binding oligomerization domain (NOD)-like receptors, detect tissue damage or microbial infection. However, it is not clear which PRRs have a major role in inducing inflammation during ER stress. Here we show that NOD1 and NOD2, two members of the NOD-like receptor family of PRRs, are important mediators of ER-stress-induced inflammation in mouse and human cells. The ER stress inducers thapsigargin and dithiothreitol trigger production of the pro-inflammatory cytokine IL-6 in a NOD1/2-dependent fashion. Inflammation and IL-6 production triggered by infection with Brucella abortus, which induces ER stress by injecting the type IV secretion system effector protein VceC into host cells, is TRAF2, NOD1/2 and RIP2-dependent and can be reduced by treatment with the ER stress inhibitor tauroursodeoxycholate or an IRE1α kinase inhibitor. The association of NOD1 and NOD2 with pro-inflammatory responses induced by the IRE1α/TRAF2 signalling pathway provides a novel link between innate immunity and ER-stress-induced inflammation.

  3. NOD1 and NOD2 signalling links ER stress with inflammation.

    PubMed

    Keestra-Gounder, A Marijke; Byndloss, Mariana X; Seyffert, Núbia; Young, Briana M; Chávez-Arroyo, Alfredo; Tsai, April Y; Cevallos, Stephanie A; Winter, Maria G; Pham, Oanh H; Tiffany, Connor R; de Jong, Maarten F; Kerrinnes, Tobias; Ravindran, Resmi; Luciw, Paul A; McSorley, Stephen J; Bäumler, Andreas J; Tsolis, Renée M

    2016-04-21

    Endoplasmic reticulum (ER) stress is a major contributor to inflammatory diseases, such as Crohn disease and type 2 diabetes. ER stress induces the unfolded protein response, which involves activation of three transmembrane receptors, ATF6, PERK and IRE1α. Once activated, IRE1α recruits TRAF2 to the ER membrane to initiate inflammatory responses via the NF-κB pathway. Inflammation is commonly triggered when pattern recognition receptors (PRRs), such as Toll-like receptors or nucleotide-binding oligomerization domain (NOD)-like receptors, detect tissue damage or microbial infection. However, it is not clear which PRRs have a major role in inducing inflammation during ER stress. Here we show that NOD1 and NOD2, two members of the NOD-like receptor family of PRRs, are important mediators of ER-stress-induced inflammation in mouse and human cells. The ER stress inducers thapsigargin and dithiothreitol trigger production of the pro-inflammatory cytokine IL-6 in a NOD1/2-dependent fashion. Inflammation and IL-6 production triggered by infection with Brucella abortus, which induces ER stress by injecting the type IV secretion system effector protein VceC into host cells, is TRAF2, NOD1/2 and RIP2-dependent and can be reduced by treatment with the ER stress inhibitor tauroursodeoxycholate or an IRE1α kinase inhibitor. The association of NOD1 and NOD2 with pro-inflammatory responses induced by the IRE1α/TRAF2 signalling pathway provides a novel link between innate immunity and ER-stress-induced inflammation. PMID:27007849

  4. A thrombospondin-dependent pathway for a protective ER stress response

    PubMed Central

    Lynch, Jeffrey M.; Maillet, Marjorie; Vanhoutte, Davy; Schloemer, Aryn; Sargent, Michelle A.; Blair, N. Scott; Lynch, Kaari A.; Okada, Tetsuya; Aronow, Bruce J.; Osinska, Hanna; Prywes, Ron; Lorenz, John N.; Mori, Kazutoshi; Lawler, Jack; Robbins, Jeffrey; Molkentin, Jeffery D.

    2012-01-01

    SUMMARY Thrombospondin (Thbs) proteins are induced in sites of tissue damage or active remodeling. The endoplasmic reticulum (ER) stress response is also prominently induced with disease where it regulates protein production and resolution of misfolded proteins. Here we describe a novel function for Thbs’ as ER resident effectors of an adaptive ER stress response. Thbs4 cardiac-specific transgenic mice were protected from myocardial injury while Thbs4−/− mice were sensitized to cardiac maladaptation. Thbs induction produced a unique profile of adaptive ER stress response factors and expansion of the ER and downstream vesicles. The type-3 repeat domain in Thbs’ bind the ER luminal domain of activating transcription factor 6α (Atf6α) to promote its nuclear shuttling. Thbs4−/−mice failed to show activation of Atf6α and other ER stress response factors with injury, and Thbs4-mediated protection was lost when Atf6α was deleted. Hence, Thbs’ can function inside the cell during disease/remodeling to augment ER function and protect through a mechanism involving regulation of Atf6α. PMID:22682248

  5. Alleviation of exogenous oligochitosan on wheat seedlings growth under salt stress.

    PubMed

    Ma, Lianju; Li, Yueying; Yu, Cuimei; Wang, Yan; Li, Xuemei; Li, Na; Chen, Qiang; Bu, Ning

    2012-04-01

    Hydroponic experiments were carried out to study the role of oligochitosan in enhancing wheat (Triticum aestivum L.) resistance to salt stress. Data were collected on plant biomass, chlorophyll content, photosynthetic rate (P (n)), stomatal conductance (g (s)), proline content, antioxidant enzyme activities, and malondialdehyde (MDA) content. Under 150 mM salt stress, plant growth was significantly inhibited. Shoot length, root length, and dry weight were sharply reduced by 26%, 31%, and 20%, respectively, of the control. Superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were increased by 28%, 13%, and 26%, respectively, of the control and MDA content largely accumulated, which was 1.5-fold of the control. However, 0.0625% oligochitosan pretreatment alleviated the adverse effects of salt stress, which was reflected by increasing root length, shoot length, dry weight, chlorophyll content, P (n,) and g (s). Furthermore, it also showed that oligochitosan pretreatment significantly increased antioxidant enzyme (SOD, CAT and POD) activities, and reduced MDA content in leaves. Meanwhile, the accumulation of proline was markedly accelerated. The results indicated that oligochitosan pretreatment ameliorated the adverse effects and partially protected the seedlings from salt stress during the following growth period.

  6. A role for motoneuron subtype-selective ER stress in disease manifestations of FALS mice.

    PubMed

    Saxena, Smita; Cabuy, Erik; Caroni, Pico

    2009-05-01

    The mechanisms underlying disease manifestations in neurodegeneration remain unclear, but their understanding is critical to devising effective therapies. We carry out a longitudinal analysis in vivo of identified motoneurons selectively vulnerable (VUL) or resistant (RES) to motoneuron disease (amyotrophic lateral sclerosis, ALS) and show that subtype-selective endoplasmic reticulum (ER) stress responses influence disease manifestations. VUL motoneurons were selectively prone to ER stress and showed gradually upregulated ER stress markers from birth on in three mouse models of familial ALS (FALS). 25-30 days before the earliest denervations, ubiquitin signals increased in both VUL and RES motoneurons, but an unfolded protein response coupled with microglial activation was initiated selectively in VUL motoneurons. This transition was followed by selective axonal degeneration and spreading stress. The ER stress-protective agent salubrinal attenuated disease manifestations and delayed progression, whereas chronic enhancement of ER stress promoted disease. Thus, whereas all motoneurons are preferentially affected in ALS, ER stress responses in specific motoneuron subtypes influence the progressive manifestations of weakening and paralysis.

  7. BODIPY-Coumarin Conjugate as an Endoplasmic Reticulum Membrane Fluidity Sensor and Its Application to ER Stress Models.

    PubMed

    Lee, Hoyeon; Yang, Zhigang; Wi, Youngjin; Kim, Tae Woo; Verwilst, Peter; Lee, Yun Hak; Han, Ga-In; Kang, Chulhun; Kim, Jong Seung

    2015-12-16

    An endoplasmic reticulum (ER) membrane-selective chemosensor composed of BODIPY and coumarin moieties and a long alkyl chain (n-C18) was synthesized. The emission ratio of BODIPY to coumarin depends on the solution viscosity. The probe is localized to the ER membrane and was applied to reveal the reduced ER membrane fluidity under ER stress conditions.

  8. The binary switch that controls the life and death decisions of ER stressed beta cells

    PubMed Central

    Oslowski, Christine M.; Urano, Fumihiko

    2010-01-01

    Diabetes mellitus is a group of common metabolic disorders defined by hyperglycemia. One of the most important factors contributing to hyperglycemia is dysfunction and death of β cells. Increasing experimental, clinical, and genetic evidence indicates that endoplasmic reticulum (ER) stress plays an important role in β cell dysfunction and death during the progression of type 1 and type 2 diabetes as well as genetic forms of diabetes such as Wolfram syndrome. The mechanisms of ER stress-mediated β cell dysfunction and death are complex and not homogenous. Here we review the recent key findings on the role of ER stress and the unfolded protein response (UPR) in β cells and the mechanisms of ER stress mediated β cell dysfunction and death. Complete understanding of these mechanisms will lead to novel therapeutic modalities for diabetes. PMID:21168319

  9. Parkin is transcriptionally regulated by ATF4: evidence for an interconnection between mitochondrial stress and ER stress.

    PubMed

    Bouman, L; Schlierf, A; Lutz, A K; Shan, J; Deinlein, A; Kast, J; Galehdar, Z; Palmisano, V; Patenge, N; Berg, D; Gasser, T; Augustin, R; Trümbach, D; Irrcher, I; Park, D S; Wurst, W; Kilberg, M S; Tatzelt, J; Winklhofer, K F

    2011-05-01

    Loss of parkin function is responsible for the majority of autosomal recessive parkinsonism. Here, we show that parkin is not only a stress-protective, but also a stress-inducible protein. Both mitochondrial and endoplasmic reticulum (ER) stress induce an increase in parkin-specific mRNA and protein levels. The stress-induced upregulation of parkin is mediated by ATF4, a transcription factor of the unfolded protein response (UPR) that binds to a specific CREB/ATF site within the parkin promoter. Interestingly, c-Jun can bind to the same site, but acts as a transcriptional repressor of parkin gene expression. We also present evidence that mitochondrial damage can induce ER stress, leading to the activation of the UPR, and thereby to an upregulation of parkin expression. Vice versa, ER stress results in mitochondrial damage, which can be prevented by parkin. Notably, the activity of parkin to protect cells from stress-induced cell death is independent of the proteasome, indicating that proteasomal degradation of parkin substrates cannot explain the cytoprotective activity of parkin. Our study supports the notion that parkin has a role in the interorganellar crosstalk between the ER and mitochondria to promote cell survival under stress, suggesting that both ER and mitochondrial stress can contribute to the pathogenesis of Parkinson's disease.

  10. β-aminobutyric acid mediated drought stress alleviation in maize (Zea mays L.).

    PubMed

    Shaw, Arun K; Bhardwaj, Pardeep K; Ghosh, Supriya; Roy, Sankhajit; Saha, Suman; Sherpa, Ang R; Saha, Samir K; Hossain, Zahed

    2016-02-01

    The present study highlights the role of β-aminobutyric acid (BABA) in alleviating drought stress effects in maize (Zea mays L.). Chemical priming was imposed by pretreating 1-week-old plants with 600 μM BABA prior to applying drought stress. Specific activities of key antioxidant enzymes and metabolites (ascorbate and glutathione) levels of ascorbate-glutathione cycle were studied to unravel the priming-induced modulation of plant defense system. Furthermore, changes in endogenous ABA and JA concentrations as well as mRNA expressions of key genes involved in their respective biosynthesis pathways were monitored in BABA-primed (BABA+) and non-primed (BABA-) leaves of drought-challenged plants to better understand the mechanistic insights into the BABA-induced hormonal regulation of plant response to water-deficit stress. Accelerated stomatal closure, high relative water content, and less membrane damage were observed in BABA-primed leaves under water-deficit condition. Elevated APX and SOD activity in non-primed leaves found to be insufficient to scavenge all H2O2 and O2 (·-) resulting in oxidative burst as evident after histochemical staining with NBT and DAB. A higher proline accumulation in non-primed leaves also does not give much protection against drought stress. Increased GR activity supported with the enhanced mRNA and protein expressions might help the BABA-primed plants to maintain a high GSH pool essential for sustaining balanced redox status to counter drought-induced oxidative stress damages. Hormonal analysis suggests that in maize, BABA-potentiated drought tolerance is primarily mediated through JA-dependent pathway by the activation of antioxidant defense systems while ABA biosynthesis pathway also plays an important role in fine-tuning of drought stress response.

  11. Hesperidin alleviates acetaminophen induced toxicity in Wistar rats by abrogation of oxidative stress, apoptosis and inflammation.

    PubMed

    Ahmad, Shiekh Tanveer; Arjumand, Wani; Nafees, Sana; Seth, Amlesh; Ali, Nemat; Rashid, Summya; Sultana, Sarwat

    2012-01-25

    Acetaminophen (APAP) is a widely used analgesic and antipyretic drug, but at high dose it leads to undesirable side effects, such as hepatotoxicity and nephrotoxicity. The present study demonstrates the comparative hepatoprotective and nephroprotective activity of hesperidin (HD), a naturally occurring bioflavonoid against APAP induced toxicity. APAP induces hepatotoxicity and nephrotoxicity as was evident by abnormal deviation in the levels of antioxidant enzymes. Moreover, APAP induced renal damage by inducing apoptotic death and inflammation in renal tubular cells, manifested by an increase in the expression of caspase-3, caspase-9, NFkB, iNOS, Kim-1 and decrease in Bcl-2 expression. These results were further supported by the histopathological examination of kidney. All these features of APAP toxicity were reversed by the co-administration of HD. Therefore, our study favors the view that HD may be a useful modulator in alleviating APAP induced oxidative stress and toxicity.

  12. Naringenin Alleviates Cadmium-Induced Toxicity through the Abrogation of Oxidative Stress in Swiss Albino Mice.

    PubMed

    Das, Avratanu; Roy, Amrita; Das, Ruma; Bhattacharya, Sanjib; Haldar, Pallab Kanti

    2016-01-01

    The present study evaluates the protective potential of the flavonoid naringenin (NRG) against experimentally induced cadmium (Cd) toxicity in Swiss albino mice. NRG (4 and 8 mg/kg) was orally administered to mice 30 min before oral administration of CdCl2 (12 mg/kg) for 11 consecutive days. On the 12th day, we evaluated body and organ weights, hematological profiles, serum biochemical profiles, and hepatic and renal tissue antioxidative parameters including lipid peroxidation, reduced and oxidized glutathione, glutathione-S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase, and catalase. Cotreatment with NRG markedly and significantly normalized body and organ weights, hematological profiles, and serum biochemical profiles and significantly modulated all of the hepatic and renal tissue biochemical parameters in Cd-intoxicated mice. The present findings show that NRG possesses a remarkable alleviative effect against Cd-induced toxicity in albino mice, mediated by abrogation of Cd-induced oxidative stress by multiple mechanisms. PMID:27481493

  13. Naringin Alleviates Diabetic Kidney Disease through Inhibiting Oxidative Stress and Inflammatory Reaction

    PubMed Central

    Chen, Fenqin; Zhang, Ning; Ma, Xiaoyu; Huang, Ting; Shao, Ying; Wu, Can; Wang, Qiuyue

    2015-01-01

    Naringin, a flavanone glycoside extracted from Citrus grandis Osbeck, has a wide range of pharmacological effects. In the present study we aimed at demonstrating the protective effect of naringin against diabetic kidney disease (DKD) and elucidating its possible molecular mechanism underlying. The beneficial effect of naringin was assessed in rats with streptozotocin (STZ)-induced diabetes and high glucose-induced HBZY-1 cells. According to our results, first we found that naringin relieved kidney injury, improved renal function and inhibited collagen formation and renal interstitial fibrosis. Second, we confirmed that naringin restrained oxidative stress by activating Nrf2 antioxidant pathway. Moreover, the results suggested that naringin significantly resisted inflammatory reaction by inhibiting NF- κ B signaling pathway. Taken together, our results demonstrate that naringin effectively alleviates DKD, which provide theoretical basis for naringin clinically used to treatment of DKD. PMID:26619044

  14. ER-mediated stress induces mitochondrial-dependent caspases activation in NT2 neuron-like cells.

    PubMed

    Arduino, Daniela M; Esteves, A Raquel; Domingues, A Filipa; Pereira, Claudia M F; Cardoso, Sandra M; Oliveira, Catarina R

    2009-11-30

    Recent studies have revealed that endoplasmic reticulum (ER) disturbance is involved in the pathophysiology of neurodegenerative disorders, contributing to the activation of the ER stress-mediated apoptotic pathway. Therefore, we investigated here the molecular mechanisms underlying the ER-mitochondria axis, focusing on calcium as a potential mediator of cell death signals. Using NT2 cells treated with brefeldin A or tunicamycin, we observed that ER stress induces changes in the mitochondrial function, impairing mitochondrial membrane potential and distressing mitochondrial respiratory chain complex Moreover, stress stimuli at ER level evoked calcium fluxes between ER and mitochondria. Under these conditions, ER stress activated the unfolded protein response by an overexpression of GRP78, and also caspase-4 and-2, both involved upstream of caspase-9. Our findings show that ER and mitochondria interconnection plays a prominent role in the induction of neuronal cell death under particular stress circumstances.

  15. Sulfur Dioxide Enhances Endogenous Hydrogen Sulfide Accumulation and Alleviates Oxidative Stress Induced by Aluminum Stress in Germinating Wheat Seeds.

    PubMed

    Zhu, Dong-Bo; Hu, Kang-Di; Guo, Xi-Kai; Liu, Yong; Hu, Lan-Ying; Li, Yan-Hong; Wang, Song-Hua; Zhang, Hua

    2015-01-01

    Aluminum ions are especially toxic to plants in acidic soils. Here we present evidences that SO2 protects germinating wheat grains against aluminum stress. SO2 donor (NaHSO3/Na2SO3) pretreatment at 1.2 mM reduced the accumulation of superoxide anion, hydrogen peroxide, and malondialdehyde, enhanced the activities of guaiacol peroxidase, catalase, and ascorbate peroxidase, and decreased the activity of lipoxygenase in germinating wheat grains exposed to Al stress. We also observed higher accumulation of hydrogen sulfide (H2S) in SO2-pretreated grain, suggesting the tight relation between sulfite and sulfide. Wheat grains geminated in water for 36 h were pretreated with or without 1 mM SO2 donor for 12 h prior to exposure to Al stress for 48 h and the ameliorating effects of SO2 on wheat radicles were studied. SO2 donor pretreatment reduced the content of reactive oxygen species, protected membrane integrity, and reduced Al accumulation in wheat radicles. Gene expression analysis showed that SO2 donor pretreatment decreased the expression of Al-responsive genes TaWali1, TaWali2, TaWali3, TaWali5, TaWali6, and TaALMT1 in radicles exposed to Al stress. These results suggested that SO2 could increase endogenous H2S accumulation and the antioxidant capability and decrease endogenous Al content in wheat grains to alleviate Al stress. PMID:26078810

  16. Nitrogen fertilizer improves boron phytoextraction by Brassica juncea grown in contaminated sediments and alleviates plant stress.

    PubMed

    Giansoldati, Virginia; Tassi, Eliana; Morelli, Elisabetta; Gabellieri, Edi; Pedron, Francesca; Barbafieri, Meri

    2012-06-01

    In this study we evaluated the effect of different fertilizer treatments on Brassica plants grown on boron-contaminated sediments. Experiments were conducted in the laboratory and on the lysimeter scale. At laboratory scale (microcosm), five different fertilizers were tested for a 35-d period. On the lysimeter scale, nitrogen fertilization was tested at three different doses and plants were allowed to grow until the end of the vegetative phase (70 d). Results showed that nitrogen application had effectively increased plant biomass production, while B uptake was not affected. Total B phytoextracted increased three-fold when the highest nitrogen dose was applied. Phytotoxicity on Brassica was evaluated by biochemical parameters. In plants grown in unfertilized B-contaminated sediments, the activity of antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX) and pyrogallol peroxidase (PPX) increased, whereas catalase (CAT) decreased with respect to control plants. Addition of N progressively mitigated the alteration of enzymatic activity, thus suggesting that N can aid in alleviating B-induced oxidative stress. SOD activity was restored to control levels just at the lowest N treatment, whereas the CAT inhibition was partially restored only at the highest one. N application also lowered the B-induced increase in APX and PPX activities. Increased glutathione reductase activity indicated the need to restore the oxidative balance of glutathione. Data also suggest a role of glutathione and phytochelatins in B defense mechanisms. Results suggest that the nitrogen fertilizer was effective in improving B phytoextraction by increasing Brassica biomass and by alleviating B-induced oxidative stress. PMID:22382070

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

    PubMed

    Chalil, Sreeda; Pierre, Nicolas; Bakker, Astrid D; Manders, Ralph J; Pletsers, Annelies; Francaux, Marc; Klein-Nulend, Jenneke; Jaspers, Richard T; Deldicque, Louise

    2015-12-25

    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 old (26 mo) mice and weighed. ER stress markers in each muscle were quantified, and the anabolic response to leucine was assessed by measuring the phosphorylation state of S6K1 in soleus and EDL using an ex vivo muscle model. Aging reduced the muscle-to-body weight ratio in soleus, gastrocnemius, and plantaris, but not in EDL and tibialis anterior. Compared to adult mice, the expression of ER stress markers BiP and IRE1α was higher in EDL, and phospho-eIF2α was higher in soleus and EDL of old mice. S6K1 response to leucine was impaired in soleus, but not in EDL, suggesting that anabolic resistance contributes to soleus weight loss in old mice. Pre-incubation with ER stress inducer tunicamycin before leucine stimulation increased S6K1 phosphorylation beyond the level reached by leucine alone. Since tunicamycin did not impair leucine-induced S6K1 response, and based on the different ER stress marker regulation patterns, ER stress is probably not involved in anabolic resistance in skeletal muscle with aging.

  18. RTN1 mediates progression of kidney disease by inducing ER stress

    PubMed Central

    Fan, Ying; Xiao, Wenzhen; Li, Zhengzhe; Li, Xuezhu; Chuang, Peter Y.; Jim, Belinda; Zhang, Weijia; Wei, Chengguo; Wang, Niansong; Jia, Weiping; Xiong, Huabao; Lee, Kyung; He, John C.

    2015-01-01

    Identification of new biomarkers and drug targets for chronic kidney disease (CKD) is required for the development of more effective therapy. Here we report an association between expression of reticulon 1 (RTN1) and severity of CKD. An isoform-specific increase in the expression of RTN1A is detected in the diseased kidneys from mice and humans, and correlates inversely with renal function in patients with diabetic nephropathy. RTN1 overexpression in renal cells induces ER stress and apoptosis, whereas RTN1 knockdown attenuates tunicamycin-induced and hyperglycaemia-induced ER stress and apoptosis. RTN1A interacts with PERK through its N-terminal and C-terminal domains, and mutation of these domains prevents this effect on ER stress. Knockdown of Rtn1a expression in vivo attenuates ER stress and renal fibrosis in mice with unilateral ureteral obstruction, and also attenuates ER stress, proteinuria, glomerular hypertrophy and mesangial expansion in diabetic mice. Together, these data indicate that RTN1A contributes to progression of kidney disease by inducing ER stress. PMID:26227493

  19. Proteus mirabilis alleviates zinc toxicity by preventing oxidative stress in maize (Zea mays) plants.

    PubMed

    Islam, Faisal; Yasmeen, Tahira; Riaz, Muhammad; Arif, Muhammad Saleem; Ali, Shafaqat; Raza, Syed Hammad

    2014-12-01

    Plant-associated bacteria can have beneficial effects on the growth and health of their host. However, the role of plant growth promoting bacteria (PGPR), under metal stress, has not been widely investigated. The present study investigated the possible mandatory role of plant growth promoting rhizobacteria in protecting plants from zinc (Zn) toxicity. The exposure of maize plants to 50µM zinc inhibited biomass production, decreased chlorophyll, total soluble protein and strongly increased accumulation of Zn in both root and shoot. Similarly, Zn enhanced hydrogen peroxide, electrolyte leakage and lipid peroxidation as indicated by malondaldehyde accumulation. Pre-soaking with novel Zn tolerant bacterial strain Proteus mirabilis (ZK1) isolated zinc (Zn) contaminated soil, alleviated the negative effect of Zn on growth and led to a decrease in oxidative injuries caused by Zn. Furthermore, strain ZK1 significantly enhanced the activities of catalase, guaiacol peroxidase, superoxide dismutase and ascorbic acid but lowered the Proline accumulation in Zn stressed plants. The results suggested that the inoculation of Zea mays plants with P. mirabilis during an earlier growth period could be related to its plant growth promoting activities and avoidance of cumulative damage upon exposure to Zn, thus reducing the negative consequences of oxidative stress caused by heavy metal toxicity.

  20. Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: physiological responses.

    PubMed

    Penella, Consuelo; Nebauer, Sergio G; Bautista, Alberto San; López-Galarza, Salvador; Calatayud, Ángeles

    2014-06-15

    nitrate reductase activity in the roots was observed, mainly in plants grafted onto the sensitive rootstocks, as well as the ungrafted plants, and this was associated with the lessened flux to the leaves. This study suggests that PEG-induced water stress can be partially alleviated by using tolerant accessions as rootstocks.

  1. Alleviating effects of exogenous NO on tomato seedlings under combined Cu and Cd stress.

    PubMed

    Wang, Yi-Jun; Dong, Yu-Xiu; Wang, Juan; Cui, Xiu-Min

    2016-03-01

    To investigate the effect of NO on the different origin and regulation of oxidative stress of Cu and/or Cd, tomato seedlings were treated with Cu, Cd, or Cu + Cd in a nutrient solution culture system. The main effect of Cu(2+) was a significant reduction in root activity and nitrate reductase (NR) activity, which was similar to that under 50 μM Cd treatment, but promoted Cu accumulation. The supply of Cu under Cd treatment decreased Cd concentration, while not altered Cu concentration by contrast with Cu treatment, which is suggestive of a replacement of Cu(2+) with Cd(2+) and effective decrease in the boiotoxicity of 50 μM Cd(2+) to tomato seedlings. However, NO alleviated the restriction to NR activity significantly and made the biomass of tomato seedlings recover under Cd treatment, and also increased root activity under Cu and Cu + Cd treatment. Exogenous NO markedly reduced the absorption and transportation of Cu but did not obviously change the translocation of Cd to the aboveground parts under Cu + Cd treatment. Both metals induced lipid peroxidation via the decreasing activation of antioxidant enzymes. The antioxidant enzyme system worked differently under Cu, Cd, or Cu + Cd stress. The activities of peroxidase (POD) and catalase (CAT) were higher under single Cd stress than under the control. Meanwhile, Cu + Cd treatment decreased the activities of POD, superoxide dismutase (SOD), and ascorbic acid peroxidase (APX). Exogenous NO increased POD and SOD activities in the leaves and roots, and CAT activity in the roots under combined Cu and Cd stress. These results suggest that a different response and regulation mechanism that involves exogenous NO is present in tomato seedlings under Cu and Cd stress.

  2. Priming of seeds with nitric oxide donor sodium nitroprusside (SNP) alleviates the inhibition on wheat seed germination by salt stress.

    PubMed

    Duan, Pei; Ding, Feng; Wang, Fang; Wang, Bao-Shan

    2007-06-01

    The effect of SNP, an NO donor, on seed germination of wheat (Triticum aestivum L. cv. 'DK961') under salt stress was studied. The results showed that priming of seeds with 0.06 mmol/L SNP for 24 h markedly alleviated the decrease of the germination percentage, germination index, vigor index and imbibition rate of wheat seeds under salt stress. SNP significantly alleviated the decrease of the beta-amylase activity but almost did not affect the alpha-amylase activity of wheat seeds under salt stress. SNP slightly increased the alpha-amylase isoenzymes (especially isoenzyme 3) and significantly increased the beta-amylase isoenzymes (especially isoenzyme d, e, f and g). SNP pretreatment decreased Na(+) content, but increased the K(+) content, resulting in a mark increase of K(+)/Na(+) ratio of wheat seedlings under salt stress. These results suggested that NO is involved in promoting wheat seed germination under salt stress by increasing the beta-amylase activity.

  3. NOXA contributes to the sensitivity of PERK-deficient cells to ER stress.

    PubMed

    Gupta, Sanjeev; Giricz, Zoltan; Natoni, Alessandro; Donnelly, Neysan; Deegan, Shane; Szegezdi, Eva; Samali, Afshin

    2012-11-16

    PKR-like ER kinase (PERK) deficient mouse embryonic fibroblasts (MEFs) are hypersensitive to ER stress-induced apoptosis. However, the molecular determinants of increased sensitivity of PERK(-/-) MEFs are not clearly understood. Here we show that induction of several Unfolded Protein Response (UPR) target genes is attenuated in PERK(-/-) MEFs. We also report elevated expression of the BH3-only protein, NOXA in PERK(-/-) MEFs. Further, shRNA-mediated knockdown of NOXA rescued the hypersensitivity of PERK(-/-) MEFs to ER stress-induced apoptosis. Taken together our results suggest that compromised induction of UPR and increased NOXA expression contributes to hypersensitivity of PERK(-/-) MEFs to ER stress-induced apoptosis. PMID:23068609

  4. Silicon improves seed germination and alleviates oxidative stress of bud seedlings in tomato under water deficit stress.

    PubMed

    Shi, Yu; Zhang, Yi; Yao, Hejin; Wu, Jiawen; Sun, Hao; Gong, Haijun

    2014-05-01

    The beneficial effects of silicon on plant growth and development under drought have been widely reported. However, little information is available on the effects of silicon on seed germination under drought. In this work, the effects of exogenous silicon (0.5 mM) on the seed germination and tolerance performance of tomato (Solanum lycopersicum L.) bud seedlings under water deficit stress simulated by 10% (w/v) polyethylene glycol (PEG-6000) were investigated in four cultivars ('Jinpengchaoguan', 'Zhongza No.9', 'Houpi L402' and 'Oubao318'). The results showed that the seed germination percentage was notably decreased in the four cultivars under water stress, and it was significantly improved by added silicon. Compared with the non-silicon treatment, silicon addition increased the activities of superoxide dismutase (SOD) and catalase (CAT), and decreased the production of superoxide anion (O2·) and hydrogen peroxide (H2O2) in the radicles of bud seedlings under water stress. Addition of silicon decreased the total phenol concentrations in radicles under water stress, which might contribute to the decrease of peroxidase (POD) activity, as observed in the in vivo and in vitro experiments. The decrease of POD activity might contribute to a less accumulation of hydroxyl radical (·OH) under water stress. Silicon addition also decreased the concentrations of malondialdehyde (MDA) in the radicles under stress, indicating decreased lipid peroxidation. These results suggest that exogenous silicon could improve seed germination and alleviate oxidative stress to bud seedling of tomato by enhancing antioxidant defense. The positive effects of silicon observed in a silicon-excluder also suggest the active involvement of silicon in biochemical processes in plants.

  5. PERK Limits Drosophila Lifespan by Promoting Intestinal Stem Cell Proliferation in Response to ER Stress

    PubMed Central

    Wang, Lifen; Ryoo, Hyung Don; Qi, Yanyan; Jasper, Heinrich

    2015-01-01

    Intestinal homeostasis requires precise control of intestinal stem cell (ISC) proliferation. In Drosophila, this control declines with age largely due to chronic activation of stress signaling and associated chronic inflammatory conditions. An important contributor to this condition is the age-associated increase in endoplasmic reticulum (ER) stress. Here we show that the PKR-like ER kinase (PERK) integrates both cell-autonomous and non-autonomous ER stress stimuli to induce ISC proliferation. In addition to responding to cell-intrinsic ER stress, PERK is also specifically activated in ISCs by JAK/Stat signaling in response to ER stress in neighboring cells. The activation of PERK is required for homeostatic regeneration, as well as for acute regenerative responses, yet the chronic engagement of this response becomes deleterious in aging flies. Accordingly, knocking down PERK in ISCs is sufficient to promote intestinal homeostasis and extend lifespan. Our studies highlight the significance of the PERK branch of the unfolded protein response of the ER (UPRER) in intestinal homeostasis and provide a viable strategy to improve organismal health- and lifespan. PMID:25945494

  6. PERK Limits Drosophila Lifespan by Promoting Intestinal Stem Cell Proliferation in Response to ER Stress.

    PubMed

    Wang, Lifen; Ryoo, Hyung Don; Qi, Yanyan; Jasper, Heinrich

    2015-05-01

    Intestinal homeostasis requires precise control of intestinal stem cell (ISC) proliferation. In Drosophila, this control declines with age largely due to chronic activation of stress signaling and associated chronic inflammatory conditions. An important contributor to this condition is the age-associated increase in endoplasmic reticulum (ER) stress. Here we show that the PKR-like ER kinase (PERK) integrates both cell-autonomous and non-autonomous ER stress stimuli to induce ISC proliferation. In addition to responding to cell-intrinsic ER stress, PERK is also specifically activated in ISCs by JAK/Stat signaling in response to ER stress in neighboring cells. The activation of PERK is required for homeostatic regeneration, as well as for acute regenerative responses, yet the chronic engagement of this response becomes deleterious in aging flies. Accordingly, knocking down PERK in ISCs is sufficient to promote intestinal homeostasis and extend lifespan. Our studies highlight the significance of the PERK branch of the unfolded protein response of the ER (UPRER) in intestinal homeostasis and provide a viable strategy to improve organismal health- and lifespan. PMID:25945494

  7. PERK Limits Drosophila Lifespan by Promoting Intestinal Stem Cell Proliferation in Response to ER Stress.

    PubMed

    Wang, Lifen; Ryoo, Hyung Don; Qi, Yanyan; Jasper, Heinrich

    2015-05-01

    Intestinal homeostasis requires precise control of intestinal stem cell (ISC) proliferation. In Drosophila, this control declines with age largely due to chronic activation of stress signaling and associated chronic inflammatory conditions. An important contributor to this condition is the age-associated increase in endoplasmic reticulum (ER) stress. Here we show that the PKR-like ER kinase (PERK) integrates both cell-autonomous and non-autonomous ER stress stimuli to induce ISC proliferation. In addition to responding to cell-intrinsic ER stress, PERK is also specifically activated in ISCs by JAK/Stat signaling in response to ER stress in neighboring cells. The activation of PERK is required for homeostatic regeneration, as well as for acute regenerative responses, yet the chronic engagement of this response becomes deleterious in aging flies. Accordingly, knocking down PERK in ISCs is sufficient to promote intestinal homeostasis and extend lifespan. Our studies highlight the significance of the PERK branch of the unfolded protein response of the ER (UPRER) in intestinal homeostasis and provide a viable strategy to improve organismal health- and lifespan.

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

    PubMed

    Binet, François; Chiasson, Sonia; Girard, Denis

    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 eIF2alpha 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.

  9. Polyhydroxyfullerene binds cadmium ions and alleviates metal-induced oxidative stress in Saccharomyces cerevisiae.

    PubMed

    Pradhan, Arunava; Pinheiro, José Paulo; Seena, Sahadevan; Pascoal, Cláudia; Cássio, Fernanda

    2014-09-01

    The water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeast Saccharomyces cerevisiae by exposing cells to Cd (≤5 mg liter(-1)) in the absence or presence of PHF (≤500 mg liter(-1)) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.

  10. Polyhydroxyfullerene Binds Cadmium Ions and Alleviates Metal-Induced Oxidative Stress in Saccharomyces cerevisiae

    PubMed Central

    Pradhan, Arunava; Pinheiro, José Paulo; Seena, Sahadevan; Pascoal, Cláudia

    2014-01-01

    The water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeast Saccharomyces cerevisiae by exposing cells to Cd (≤5 mg liter−1) in the absence or presence of PHF (≤500 mg liter−1) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells. PMID:25038095

  11. Strawberry consumption alleviates doxorubicin-induced toxicity by suppressing oxidative stress.

    PubMed

    Giampieri, Francesca; Alvarez-Suarez, Jose M; Gasparrini, Massimiliano; Forbes-Hernandez, Tamara Y; Afrin, Sadia; Bompadre, Stefano; Rubini, Corrado; Zizzi, Antonio; Astolfi, Paola; Santos-Buelga, Celestino; González-Paramás, Ana M; Quiles, Josè L; Mezzetti, Bruno; Battino, Maurizio

    2016-08-01

    Doxorubicin (Dox), one of the most used chemotherapeutic agents, is known to generate oxidative stress and block DNA synthesis, which result in severe dose-limiting toxicity. A strategy to protect against Dox toxic effects could be to use dietary antioxidants of which fruits and vegetable are a rich source. In this context, strawberry consumption is associated with the maintenance of good health and the prevention of several diseases, thanks to the antioxidant capacities of its bioactive compounds. The aim of the present study was to evaluate the protective effects of strawberry consumption against oxidative stress induced by Dox in rats. Animals were fed with strawberry enriched diet (15% of the total calories) for two months and Dox (10 mg/kg; i.p.) was injected at the end of the experimental period. Strawberry consumption significantly inhibited ROS production and oxidative damage biomarkers accumulation in plasma and liver tissue and alleviated histopathological changes in rat livers treated with Dox. The reduction of antioxidant enzyme activities was significantly mitigated after strawberry consumption. In addition, strawberry enriched diet ameliorated liver mitochondrial antioxidant levels and functionality. In conclusion, strawberry intake protects against Dox-induced toxicity, at plasma, liver and mitochondrial levels thanks to its high contents of bioactive compounds. PMID:27286747

  12. Turning Anxiety into Creativity: Using Postmodern Principles to Alleviate Anxiety and Stress through the Art Curriculum and Beyond

    ERIC Educational Resources Information Center

    Ferry, Lisa Marie

    2016-01-01

    The purpose of this action research study is to help students alleviate their anxiety and stress symptoms using activities based on Olivia Gude's postmodern principles. The activities included are the participants own take-along visual art journal kit and classroom projects. Professional learning outcomes include the knowledge to equip teachers…

  13. O-GlcNAc signaling attenuates ER stress-induced cardiomyocyte death.

    PubMed

    Ngoh, Gladys A; Hamid, Tariq; Prabhu, Sumanth D; Jones, Steven P

    2009-11-01

    We previously demonstrated that the O-linked beta-N-acetylglucosamine (O-GlcNAc) posttranslational modification confers cardioprotection at least partially through mitochondrial-dependent mechanisms, but it remained unclear if O-GlcNAc signaling interfered with other mechanisms of cell death. Because ischemia/hypoxia causes endoplasmic reticulum (ER) stress, we ascertained whether O-GlcNAc signaling could attenuate ER stress-induced cell death per se. Before induction of ER stress (with tunicamycin or brefeldin A), we adenovirally overexpressed O-GlcNAc transferase (AdOGT) or pharmacologically inhibited O-GlcNAcase [via O-(2-acetamido-2-deoxy-d-glucopyranosylidene) amino-N-phenylcarbamate] to augment O-GlcNAc levels or adenovirally overexpressed O-GlcNAcase to reduce O-GlcNAc levels. AdOGT significantly (P < 0.05) attenuated the activation of the maladaptive arm of the unfolded protein response [according to C/EBP homologous protein (CHOP) activation] and cardiomyocyte death (reflected by percent propidium iodide positivity). Moreover, pharmacological inhibition of O-GlcNAcase significantly (P < 0.05) mitigated ER stress-induced CHOP activation and cardiac myocyte death. Interestingly, overexpression of GCA did not alter ER stress markers but exacerbated brefeldin A-induced cardiomyocyte death. We conclude that enhanced O-GlcNAc signaling represents a partially proadaptive response to reduce ER stress-induced cell death. These results provide new insights into a possible interaction between O-GlcNAc signaling and ER stress and may partially explain a mechanism of O-GlcNAc-mediated cardioprotection. PMID:19734355

  14. A Highly Sensitive Assay for Monitoring the Secretory Pathway and ER Stress

    PubMed Central

    Breakefield, Xandra O.; Tannous, Bakhos A.

    2007-01-01

    Background 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). Methodology/Principle Findings 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. Conclusions/Significance 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. PMID:17593970

  15. Salubrinal, ER stress inhibitor, attenuates kainic acid-induced hippocampal cell death.

    PubMed

    Kim, Jung Soo; Heo, Rok Won; Kim, Hwajin; Yi, Chin-Ok; Shin, Hyun Joo; Han, Jong Woo; Roh, Gu Seob

    2014-10-01

    Kainic acid (KA)-induced neuronal death is closely linked to endoplasmic reticulum (ER) and mitochondrial dysfunction. Parkin is an ubiquitin E3 ligase that mediates the ubiquitination of the Bcl-2 family of proteins and its mutations are associated with neuronal apoptosis in neurodegenerative diseases. We investigated the effect of salubrinal, an ER stress inhibitor, on the regulation of ER stress and mitochondrial apoptosis induced by KA, in particular, by controlling parkin expression. We showed that salubrinal significantly reduced seizure activity and increased survival rates of mice with KA-induced seizures. We found that salubrinal protected neurons against apoptotic death by reducing expression of mitochondrial apoptotic factors and elF2α-ATF4-CHOP signaling proteins. Interestingly, we showed that salubrinal decreased the KA-induced parkin expression and inhibited parkin translocation to mitochondria, which suggests that parkin may regulate a cross-talk between ER and mitochondria. Collectively, inhibition of ER stress attenuates mitochondrial apoptotic and ER stress pathways and controls parkin-mediated neuronal death following KA-induced seizures. PMID:24728926

  16. Exogenous glycinebetaine alleviates the detrimental effect of Cd stress on perennial ryegrass.

    PubMed

    Lou, Yanhong; Yang, Yong; Hu, Longxing; Liu, Hongmei; Xu, Qingguo

    2015-08-01

    Glycinebetaine (GB) is an important organic osmolyte that accumulates in many plant species in response to abiotic stresses including heavy metals. The objective of this study was to investigate whether exogenous GB would ameliorate the adverse effect of cadmium (Cd) stress on perennial ryegrass (Lolium perenne). Fifty-three days old seedlings were exposed to hydroponic culture for 7 days with six treatments: T1 (control), T2 (0 mM Cd + 20 mM GB), T3 (0 mM Cd + 50 mM GB), T4 (0.5 mM Cd + 0 mM GB), T5 (0.5 mM Cd + 20 mM GB), T6 (0.5 mM Cd + 50 mM GB). Cd stress resulted in a remarkable decrease in turf quality, vertical shoot growth rate (VSGR), normalized relative transpiration (NRT) and Chlorophyll (Chl) content; with significant increases in electric conductivity (EL), malondialdehyde (MDA) content, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) activity, oxalic and tartaric acid content. Exogenous application of GB decreased EL and MDA content in Cd stressed plants, and increased turf quality, VSGR, NRT, Chl content, SOD, CAT, POD activity, oxalic, tartaric acid content, and the gene expression level of SOD and POD when compared with Cd stressed without GB. Perennial ryegrass with 20 mM GB application suppressed the Cd accumulation in both shoots and roots. A lower translocation factor of Cd was found in GB treated plants than non-GB treated plants, and the lowest translocation factor was observed in the 20 mM GB application. These results suggested that GB could alleviate the detrimental effect of Cd on perennial ryegrass and the amelioration was mainly related to the elevation in SOD, CAT, and POD at enzyme and gene expression levels, which reduced Cd content in shoots and improved cell membrane stability by reducing oxidation of membrane lipids. These findings lead us to conclude that application of GB with 20 mM is the best strategy to ameliorate the detrimental impacts of Cd stress on perennial ryegrass. PMID:26135319

  17. Palmitate induces ER calcium depletion and apoptosis in mouse podocytes subsequent to mitochondrial oxidative stress

    PubMed Central

    Xu, S; Nam, S M; Kim, J-H; Das, R; Choi, S-K; Nguyen, T T; Quan, X; Choi, S J; Chung, C H; Lee, E Y; Lee, I-K; Wiederkehr, A; Wollheim, C B; Cha, S-K; Park, K-S

    2015-01-01

    Pathologic alterations in podocytes lead to failure of an essential component of the glomerular filtration barrier and proteinuria in chronic kidney diseases. Elevated levels of saturated free fatty acid (FFA) are harmful to various tissues, implemented in the progression of diabetes and its complications such as proteinuria in diabetic nephropathy. Here, we investigated the molecular mechanism of palmitate cytotoxicity in cultured mouse podocytes. Incubation with palmitate dose-dependently increased cytosolic and mitochondrial reactive oxygen species, depolarized the mitochondrial membrane potential, impaired ATP synthesis and elicited apoptotic cell death. Palmitate not only evoked mitochondrial fragmentation but also caused marked dilation of the endoplasmic reticulum (ER). Consistently, palmitate upregulated ER stress proteins, oligomerized stromal interaction molecule 1 (STIM1) in the subplasmalemmal ER membrane, abolished the cyclopiazonic acid-induced cytosolic Ca2+ increase due to depletion of luminal ER Ca2+. Palmitate-induced ER Ca2+ depletion and cytotoxicity were blocked by a selective inhibitor of the fatty-acid transporter FAT/CD36. Loss of the ER Ca2+ pool induced by palmitate was reverted by the phospholipase C (PLC) inhibitor edelfosine. Palmitate-dependent activation of PLC was further demonstrated by following cytosolic translocation of the pleckstrin homology domain of PLC in palmitate-treated podocytes. An inhibitor of diacylglycerol (DAG) kinase, which elevates cytosolic DAG, strongly promoted ER Ca2+ depletion by low-dose palmitate. GF109203X, a PKC inhibitor, partially prevented palmitate-induced ER Ca2+ loss. Remarkably, the mitochondrial antioxidant mitoTEMPO inhibited palmitate-induced PLC activation, ER Ca2+ depletion and cytotoxicity. Palmitate elicited cytoskeletal changes in podocytes and increased albumin permeability, which was also blocked by mitoTEMPO. These data suggest that oxidative stress caused by saturated FFA leads to

  18. Unfolded protein response-induced ERdj3 secretion links ER stress to extracellular proteostasis

    PubMed Central

    Genereux, Joseph C; Qu, Song; Zhou, Minghai; Ryno, Lisa M; Wang, Shiyu; Shoulders, Matthew D; Kaufman, Randal J; Lasmézas, Corinne I; Kelly, Jeffery W; Wiseman, R Luke

    2015-01-01

    The Unfolded Protein Response (UPR) indirectly regulates extracellular proteostasis through transcriptional remodeling of endoplasmic reticulum (ER) proteostasis pathways. This remodeling attenuates secretion of misfolded, aggregation-prone proteins during ER stress. Through these activities, the UPR has a critical role in preventing the extracellular protein aggregation associated with numerous human diseases. Here, we demonstrate that UPR activation also directly influences extracellular proteostasis through the upregulation and secretion of the ER HSP40 ERdj3/DNAJB11. Secreted ERdj3 binds misfolded proteins in the extracellular space, substoichiometrically inhibits protein aggregation, and attenuates proteotoxicity of disease-associated toxic prion protein. Moreover, ERdj3 can co-secrete with destabilized, aggregation-prone proteins in a stable complex under conditions where ER chaperoning capacity is overwhelmed, preemptively providing extracellular chaperoning of proteotoxic misfolded proteins that evade ER quality control. This regulated co-secretion of ERdj3 with misfolded clients directly links ER and extracellular proteostasis during conditions of ER stress. ERdj3 is, to our knowledge, the first metazoan chaperone whose secretion into the extracellular space is regulated by the UPR, revealing a new mechanism by which UPR activation regulates extracellular proteostasis. PMID:25361606

  19. Autophagy is dispensable to overcome ER stress in the filamentous fungus Aspergillus niger.

    PubMed

    Burggraaf, Anne-Marie; Ram, Arthur F J

    2016-08-01

    Secretory proteins are subjected to stringent quality control systems in the endoplasmic reticulum (ER) which include the targeting of misfolded proteins for proteasomal destruction via the ER-associated degradation (ERAD) pathway. Since deletion of ERAD genes in the filamentous fungus Aspergillus niger had hardly any effect on growth, this study investigates whether autophagy might function as an alternative process to eliminate misfolded proteins from the ER. We generated A. niger double mutants by deleting genes essential for ERAD (derA) and autophagy (atg1 or atg8), and assessed their growth both under normal and ER stress conditions. Sensitivity toward ER stress was examined by treatment with dithiothreitol (DTT) and by expressing a mutant form of glucoamylase (mtGlaA::GFP) in which disulfide bond sites in GlaA were mutated. Misfolding of mtGlaA::GFP was confirmed, as mtGlaA::GFP accumulated in the ER. Expression of mtGlaA::GFP in ERAD and autophagy mutants resulted in a twofold higher accumulation in ΔderA and ΔderAΔatg1 strains compared to Δatg1 and wild type. As ΔderAΔatg1 mutants did not show increased sensitivity toward DTT, not even when mtGlaA::GFP was expressed, the results indicate that autophagy does not act as an alternative pathway in addition to ERAD for removing misfolded proteins from the ER in A. niger.

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

    PubMed

    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.

  1. Adaptation to hot climate and strategies to alleviate heat stress in livestock production.

    PubMed

    Renaudeau, D; Collin, A; Yahav, S; de Basilio, V; Gourdine, J L; Collier, R J

    2012-05-01

    Despite many challenges faced by animal producers, including environmental problems, diseases, economic pressure, and feed availability, it is still predicted that animal production in developing countries will continue to sustain the future growth of the world's meat production. In these areas, livestock performance is generally lower than those obtained in Western Europe and North America. Although many factors can be involved, climatic factors are among the first and crucial limiting factors of the development of animal production in warm regions. In addition, global warming will further accentuate heat stress-related problems. The objective of this paper was to review the effective strategies to alleviate heat stress in the context of tropical livestock production systems. These strategies can be classified into three groups: those increasing feed intake or decreasing metabolic heat production, those enhancing heat-loss capacities, and those involving genetic selection for heat tolerance. Under heat stress, improved production should be possible through modifications of diet composition that either promotes a higher intake or compensates the low feed consumption. In addition, altering feeding management such as a change in feeding time and/or frequency, are efficient tools to avoid excessive heat load and improve survival rate, especially in poultry. Methods to enhance heat exchange between the environment and the animal and those changing the environment to prevent or limit heat stress can be used to improve performance under hot climatic conditions. Although differences in thermal tolerance exist between livestock species (ruminants > monogastrics), there are also large differences between breeds of a species and within each breed. Consequently, the opportunity may exist to improve thermal tolerance of the animals using genetic tools. However, further research is required to quantify the genetic antagonism between adaptation and production traits to evaluate

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

    PubMed

    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 (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. PMID:27649160

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

    PubMed Central

    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

  4. Salicylic acid alleviates adverse effects of heat stress on photosynthesis through changes in proline production and ethylene formation

    PubMed Central

    Khan, M Iqbal R; Iqbal, Noushina; Masood, Asim; Per, Tasir S; Khan, Nafees A

    2013-01-01

    We investigated the potential of salicylic acid (SA) in alleviating the adverse effects of heat stress on photosynthesis in wheat (Triticum aestivum L.) cv WH 711. Activity of ribulose 1,5-bisphosphate carboxylase (Rubisco), photosynthetic-nitrogen use efficiency (NUE), and net photosynthesis decreased in plants subjected to heat stress (40°C for 6 h), but proline metabolism increased. SA treatment (0.5 mM) alleviated heat stress by increasing proline production through the increase in γ-glutamyl kinase (GK) and decrease in proline oxidase (PROX) activity, resulting in promotion of osmotic potential and water potential necessary for maintaining photosynthetic activity. Together with this, SA treatment restricted the ethylene formation in heat-stressed plants to optimal range by inhibiting activity of 1-aminocyclopropane carboxylic acid (ACC) synthase (ACS). This resulted in improved proline metabolism, N assimilation and photosynthesis. The results suggest that SA interacts with proline metabolism and ethylene formation to alleviate the adverse effects of heat stress on photosynthesis in wheat. PMID:24022274

  5. Salicylic acid alleviates adverse effects of heat stress on photosynthesis through changes in proline production and ethylene formation.

    PubMed

    Khan, M Iqbal R; Iqbal, Noushina; Masood, Asim; Per, Tasir S; Khan, Nafees A

    2013-11-01

    We investigated the potential of salicylic acid (SA) in alleviating the adverse effects of heat stress on photosynthesis in wheat (Triticum aestivum L.) cv WH 711. Activity of ribulose 1,5-bisphosphate carboxylase (Rubisco), photosynthetic-nitrogen use efficiency (NUE), and net photosynthesis decreased in plants subjected to heat stress (40 °C for 6 h), but proline metabolism increased. SA treatment (0.5 mM) alleviated heat stress by increasing proline production through the increase in γ-glutamyl kinase (GK) and decrease in proline oxidase (PROX) activity, resulting in promotion of osmotic potential and water potential necessary for maintaining photosynthetic activity. Together with this, SA treatment restricted the ethylene formation in heat-stressed plants to optimal range by inhibiting activity of 1-aminocyclopropane carboxylic acid (ACC) synthase (ACS). This resulted in improved proline metabolism, N assimilation and photosynthesis. The results suggest that SA interacts with proline metabolism and ethylene formation to alleviate the adverse effects of heat stress on photosynthesis in wheat.

  6. Distinct physiological responses of tomato and cucumber plants in silicon-mediated alleviation of cadmium stress

    PubMed Central

    Wu, Jiawen; Guo, Jia; Hu, Yanhong; Gong, Haijun

    2015-01-01

    The alleviative effects of silicon (Si) on cadmium (Cd) toxicity were investigated in cucumber (Cucumis sativus L.) and tomato (Solanum lycopersicum L.) grown hydroponically. The growth of both plant species was inhibited by 100 μM Cd, but Si application counteracted the adverse effects on growth. Si application significantly decreased the Cd concentrations in shoots of both species and roots of cucumber. The root-to-shoot transport of Cd was depressed by added Si in tomato whereas it was increased by added Si in cucumber. The total content of organic acids was decreased in tomato leaves but increased in cucumber roots and leaves by Si application under Cd stress. Si application also increased the cell wall polysaccharide levels in the roots of both species under Cd toxicity. Si-mediated changes in levels of organic acids and cell wall polysaccharides might contribute to the differences in Cd transport in the two species. In addition, Si application also mitigated Cd-induced oxidative damage in both species. The results indicate that there were different mechanisms for Si-mediated decrease in shoot Cd accumulation: in tomato, Si supply decreased root-to-shoot Cd transport; whereas in cucumber, Si supply reduced the Cd uptake by roots. It is suggested that Si-mediated Cd tolerance is associated with different physiological responses in tomato and cucumber plants. PMID:26136764

  7. Selenium alleviates cadmium toxicity by preventing oxidative stress in sunflower (Helianthus annuus) seedlings.

    PubMed

    Saidi, Issam; Chtourou, Yacine; Djebali, Wahbi

    2014-03-01

    The present study investigated the possible mediatory role of selenium (Se) in protecting plants from cadmium (Cd) toxicity. The exposure of sunflower seedlings to 20μM Cd inhibited biomass production, decreased chlorophyll and carotenoid concentrations and strongly increased accumulation of Cd in both roots and shoots. Similarly, Cd enhanced hydrogen peroxides content and lipid peroxidation as indicated by malondialdehyde accumulation. Pre-soaking seeds with Se (5, 10 and 20μM) alleviated the negative effect of Cd on growth and led to a decrease in oxidative injuries caused by Cd. Furthermore, Se enhanced the activities of catalase, ascorbate peroxidase and glutathione reductase, but lowered that of superoxide dismutase and guaiacol peroxidase. As important antioxidants, ascorbate and glutathione contents in sunflower leaves exposed to Cd were significantly decreased by Se treatment. The data suggest that the beneficial effect of Se during an earlier growth period could be related to avoidance of cumulative damage upon exposure to Cd, thus reducing the negative consequences of oxidative stress caused by heavy metal toxicity.

  8. Treadmill exercise alleviates chronic mild stress-induced depression in rats.

    PubMed

    Lee, Taeck-Hyun; Kim, Kijeong; Shin, Mal-Soon; Kim, Chang-Ju; Lim, Baek-Vin

    2015-12-01

    Depression is a major cause of disability and one of the most common public health problems. In the present study, antidepressive effect of treadmill exercise on chronic mild stress (CMS)-induced depression in rats was investigated. For this, sucrose intake test, immunohistochemistry for 5-bromo-2'-deoxyuridine, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining, and Western blot analysis for brain-derived neurotrophic factor, cyclic adenosine monophosphate response element binding protein, and endothelial nitric oxide synthase were conducted. Following adaptation to the animal vivarium and two baseline fluid intake tests, the animals were divided into four groups: the control group, the CMS-induced depression group, the CMS-induced depression and exercise group, and the CMS-induced depression and fluoxetine-treated group. The animals in the CMS groups were exposed to the CMS conditions for 8 weeks and those in the control group were exposed to the control conditions for 8 weeks. After 4 weeks of CMS, the rats in the CMS-induced depression and exercise group were made to run on a motorized treadmill for 30 min once a day for 4 weeks. In the present results, treadmill exercise alleviated CMS-induced depressive symptoms. Treadmill exercise restored sucrose consumption, increased cell proliferation, and decreased apoptotic cell death. The present results suggest the possibility that exercise may improve symptoms of depression. PMID:26730380

  9. Prepubertal Exposure to Genistein Alleviates Di-(2-ethylhexyl) Phthalate Induced Testicular Oxidative Stress in Adult Rats

    PubMed Central

    Zhang, Lian-Dong; Li, He-Cheng; Chong, Tie; Gao, Ming; Yin, Jian; Fu, De-Lai; Deng, Qian; Wang, Zi-Ming

    2014-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is the most widely used plastizer in the world and can suppress testosterone production via activation of oxidative stress. Genistein (GEN) is one of the isoflavones ingredients exhibiting weak estrogenic and potentially antioxidative effects. However, study on reproductive effects following prepubertal multiple endocrine disrupters exposure has been lacking. In this study, DEHP and GEN were administrated to prepubertal male Sprague-Dawley rats by gavage from postnatal day 22 (PND22) to PND35 with vehicle control, GEN at 50 mg/kg body weight (bw)/day (G), DEHP at 50, 150, 450 mg/kg bw/day (D50, D150, D450) and their mixture (G + D50, G + D150, G + D450). On PND90, general morphometry (body weight, AGD, organ weight, and organ coefficient), testicular redox state, and testicular histology were studied. Our results indicated that DEHP could significantly decrease sex organs weight, organ coefficient, and testicular antioxidative ability, which largely depended on the dose of DEHP. However, coadministration of GEN could partially alleviate DEHP-induced reproductive injuries via enhancement of testicular antioxidative enzymes activities, which indicates that GEN has protective effects on DEHP-induced male reproductive system damage after prepubertal exposure and GEN may have promising future in its curative antioxidative role for reproductive disorders caused by other environmental endocrine disruptors. PMID:25530965

  10. Does a sorghum-cowpea composite porridge hold promise for contributing to alleviating oxidative stress?

    PubMed

    Apea-Bah, Franklin B; Minnaar, Amanda; Bester, Megan J; Duodu, Kwaku G

    2014-08-15

    The effect of compositing red non-tannin sorghum with cream-coloured cowpea and porridge preparation on phenolic profile and radical scavenging activity was studied. A maize-soybean composite porridge representing a similar product on the South African market was used as reference sample. UPLC-QToF-MS-ESI was used to determine phenolic composition of the grain flours, their composites and porridges. Total phenolic content was determined using Folin-Ciocalteu method while radical scavenging activity was determined using the ABTS, DPPH and NO radical scavenging assays. Four benzoic acid derivatives and five cinnamic acid derivatives were identified in the samples. The predominant flavonoid subclasses identified in sorghum were flavan-3-ols, flavanones and flavones while cowpea had mainly flavan-3-ols and flavonols with soybean having mainly isoflavones. Compositing the cereals with legumes significantly (p<0.01) increased their total flavonoid content and radical scavenging activities. Sorghum-cowpea composite porridge showed better promise in contributing to alleviating radical induced oxidative stress than maize-soybean composite porridge.

  11. Arbuscular mycorrhizal fungi alleviate oxidative stress induced by ADOR and enhance antioxidant responses of tomato plants.

    PubMed

    García-Sánchez, Mercedes; Palma, José Manuel; Ocampo, Juan Antonio; García-Romera, Inmaculada; Aranda, Elisabet

    2014-03-15

    The behaviour of tomato plants inoculated with arbuscular mycorrhizal (AM) fungi grown in the presence of aqueous extracts from dry olive residue (ADOR) was studied in order to understand how this symbiotic relationship helps plants to cope with oxidative stress caused by ADOR. The influence of AM symbiosis on plant growth and other physiological parameters was also studied. Tomato plants were inoculated with the AM fungus Funneliformis mosseae and were grown in the presence of ADOR bioremediated and non-bioremediated by Coriolopsis floccosa and Penicillium chrysogenum-10. The antioxidant response as well as parameters of oxidative damage were examined in roots and leaves. The data showed a significant increase in the biomass of AM plant growth in the presence of ADOR, regardless of whether it was bioremediated. The establishment and development of the symbiosis were negatively affected after plants were exposed to ADOR. No differences were observed in the relative water content (RWC) or PS II efficiency between non-AM and AM plants. The increase in the enzymatic activities of superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6) and glutathione-S-transferase (GST; EC 2.5.1.18) were simultaneous to the reduction of MDA levels and H2O2 content in AM root growth in the presence of ADOR. Similar H2O2 levels were observed among non-AM and AM plants, although only AM plants showed reduced lipid peroxidation content, probably due to the involvement of antioxidant enzymes. The results highlight how the application of both bioremediated ADOR and AM fungi can alleviate the oxidative stress conditions, improving the growth and development of tomato plants.

  12. Arbuscular mycorrhizal fungi alleviate oxidative stress induced by ADOR and enhance antioxidant responses of tomato plants.

    PubMed

    García-Sánchez, Mercedes; Palma, José Manuel; Ocampo, Juan Antonio; García-Romera, Inmaculada; Aranda, Elisabet

    2014-03-15

    The behaviour of tomato plants inoculated with arbuscular mycorrhizal (AM) fungi grown in the presence of aqueous extracts from dry olive residue (ADOR) was studied in order to understand how this symbiotic relationship helps plants to cope with oxidative stress caused by ADOR. The influence of AM symbiosis on plant growth and other physiological parameters was also studied. Tomato plants were inoculated with the AM fungus Funneliformis mosseae and were grown in the presence of ADOR bioremediated and non-bioremediated by Coriolopsis floccosa and Penicillium chrysogenum-10. The antioxidant response as well as parameters of oxidative damage were examined in roots and leaves. The data showed a significant increase in the biomass of AM plant growth in the presence of ADOR, regardless of whether it was bioremediated. The establishment and development of the symbiosis were negatively affected after plants were exposed to ADOR. No differences were observed in the relative water content (RWC) or PS II efficiency between non-AM and AM plants. The increase in the enzymatic activities of superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6) and glutathione-S-transferase (GST; EC 2.5.1.18) were simultaneous to the reduction of MDA levels and H2O2 content in AM root growth in the presence of ADOR. Similar H2O2 levels were observed among non-AM and AM plants, although only AM plants showed reduced lipid peroxidation content, probably due to the involvement of antioxidant enzymes. The results highlight how the application of both bioremediated ADOR and AM fungi can alleviate the oxidative stress conditions, improving the growth and development of tomato plants. PMID:24594394

  13. [Alleviation of salt stress during maize seed germination by presoaking with exogenous sugar].

    PubMed

    Zhao, Ying; Yang, Ke-jun; Li, Zuo-tong; Zhao, Chang-jiang; Xu, Jing-yu; Hu, Xue- wei; Shi, Xin-xin; Ma, Li-feng

    2015-09-01

    The maize variety Kenyu 6 was used to study the effects of exogenous glucose (Glc) and sucrose (Suc) on salt tolerance of maize seeds at germination stage under 150 mmol · L(-1) NaCl treatment. Results showed that under salt stress condition, 0.5 mmol · L(-1) exogenous Glc and Suc presoaking could promote seed germination and early seedling growth. Compared with the salt treatment, Glc presoaking increased the shoot length, radicle length and corresponding dry mass up to 1.5, 1.3, 2.1 and 1.8 times, and those of the Suc presoaking treatment increased up to 1.7, 1.3. 2.7 and 1.9 times, respectively. Exogenous Glc and Suc presoaking resulted in decreased levels of thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) content of maize shoot under salt stress, which were lowered by 24.9% and 20.6% respectively. Exogenous Glc and Suc presoaking could increase the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR) and induce glucose-6-phosphate dehydrogenase (G6PDH) activity of maize shoot under salt stress. Compared with the salt treatment. Glc presoaking increased the activity of SOD, APX, GPX, GR and G6PDH by 66.2%, 62.9%, 32.0%, 38.5% and 50.5%, and those of the Suc presoaking increased by 67.5%, 59.8%, 30.0%, 38.5% and 50.4%, respectively. Glc and Suc presoaking also significantly increased the contents of ascorbic acid (ASA) and glutathione (GSH), ASA/DHA and GSH/GSSG. The G6PDH activity was found closely related with the strong antioxidation capacity induced by exogenous sugars. In addition, Glc and Suc presoaking enhanced K+/Na+ in maize shoot by 1.3 and 1.4 times of water soaking salt treatment, respectively. These results indicated that exogenous Glc and Suc presoaking could improve antioxidation capacity of maize seeds and maintain the in vivo K+/Na+ ion balance to alleviate the inhibitory effect of salt stress on maize seed germination.

  14. [Alleviation of salt stress during maize seed germination by presoaking with exogenous sugar].

    PubMed

    Zhao, Ying; Yang, Ke-jun; Li, Zuo-tong; Zhao, Chang-jiang; Xu, Jing-yu; Hu, Xue- wei; Shi, Xin-xin; Ma, Li-feng

    2015-09-01

    The maize variety Kenyu 6 was used to study the effects of exogenous glucose (Glc) and sucrose (Suc) on salt tolerance of maize seeds at germination stage under 150 mmol · L(-1) NaCl treatment. Results showed that under salt stress condition, 0.5 mmol · L(-1) exogenous Glc and Suc presoaking could promote seed germination and early seedling growth. Compared with the salt treatment, Glc presoaking increased the shoot length, radicle length and corresponding dry mass up to 1.5, 1.3, 2.1 and 1.8 times, and those of the Suc presoaking treatment increased up to 1.7, 1.3. 2.7 and 1.9 times, respectively. Exogenous Glc and Suc presoaking resulted in decreased levels of thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) content of maize shoot under salt stress, which were lowered by 24.9% and 20.6% respectively. Exogenous Glc and Suc presoaking could increase the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR) and induce glucose-6-phosphate dehydrogenase (G6PDH) activity of maize shoot under salt stress. Compared with the salt treatment. Glc presoaking increased the activity of SOD, APX, GPX, GR and G6PDH by 66.2%, 62.9%, 32.0%, 38.5% and 50.5%, and those of the Suc presoaking increased by 67.5%, 59.8%, 30.0%, 38.5% and 50.4%, respectively. Glc and Suc presoaking also significantly increased the contents of ascorbic acid (ASA) and glutathione (GSH), ASA/DHA and GSH/GSSG. The G6PDH activity was found closely related with the strong antioxidation capacity induced by exogenous sugars. In addition, Glc and Suc presoaking enhanced K+/Na+ in maize shoot by 1.3 and 1.4 times of water soaking salt treatment, respectively. These results indicated that exogenous Glc and Suc presoaking could improve antioxidation capacity of maize seeds and maintain the in vivo K+/Na+ ion balance to alleviate the inhibitory effect of salt stress on maize seed germination. PMID:26785556

  15. ER-stress and apoptosis: molecular mechanisms and potential relevance in infection.

    PubMed

    Häcker, Georg

    2014-10-01

    During ER-stress, one of the responses a cell can choose is apoptosis. Apoptosis generally is a cell's preferred response when other control mechanisms are overwhelmed. We now have a reasonably clear molecular picture what is happening once the apoptotic apparatus has been started. Unclear however are the majority of the upstream pathways that connect other signalling to apoptosis. During ER-stress, confirmed apoptosis-regulating targets are pro- and anti-apoptotic proteins of the Bcl-2-family, whose concerted action induces apoptosis. I will here discuss how mitochondrial apoptosis is triggered, how this is linked to the ER-stress response and in what way this may be relevant during microbial infections.

  16. Bacillus amyloliquefaciens supplementation alleviates immunological stress in lipopolysaccharide-challenged broilers at early age.

    PubMed

    Li, Y; Zhang, H; Chen, Y P; Yang, M X; Zhang, L L; Lu, Z X; Zhou, Y M; Wang, T

    2015-07-01

    This study was conducted to investigate the effect of Bacillus amyloliquefaciens ( BA: ) on the immune function of broilers challenged with lipopolysaccharide ( LPS: ). 192 one-day-old male Arbor Acre broiler chickens were randomly distributed into four treatments: 1) broilers fed a basal diet; 2) broilers fed a basal diet supplemented with BA; 3) LPS-challenged broilers fed a basal diet; and 4) LPS-challenged broilers fed a basal diet supplemented with BA. Each treatment consisted of six replicates with eight broilers per replicate. Broilers were intraperitoneally injected with either 500 μg LPS per kg body weight or sterile saline at 16, 18 and 20 d of age. LPS decreased the average daily gain ( ADG: , P = 0.001) and average daily feed intake (P = 0.001). The decreased ADG (P = 0.009) and increased feed conversion ratio (P = 0.047) in LPS-challenged broilers were alleviated by BA. LPS increased the relative spleen weight (P = 0.001). Relative spleen (P = 0.014) and bursa (P = 0.024) weights in the LPS-challenged broilers were reduced by BA. LPS increased white blood cell ( WBC: ) numbers (P = 0.001). However, the WBC numbers (P = 0.042) and the ratio of lymphocytes to WBC (P = 0.020) in LPS-challenged broilers were decreased with BA treatment. LPS decreased plasma lysozyme activity (P = 0.001), but increased concentrations of plasma corticosterone (P = 0.012) and IL-2 (P = 0.020). In contrast, BA increased lysozyme activity in plasma (P = 0.040). LPS increased mRNA abundances of splenic toll-like receptor 4 (P = 0.046), interferon γ (P = 0.008), IL-1β (P = 0.045) and IL-6, (P = 0.006). IL-2 (P = 0.014) and IL-6 (P = 0.074) mRNA abundances in LPS-challenged broilers were reduced by BA, although BA had an opposite effect for IL-10 mRNA expression in those broilers (P = 0.004). In conclusion, BA supplementation could partially alleviate the compromised growth performance and immune status of broilers under immune stress induced by LPS challenge at early age. PMID

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

    PubMed

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

    2016-08-01

    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

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

    PubMed

    Marré, Meghan L; James, Eddie A; Piganelli, Jon D

    2015-01-01

    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 (APCs) 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. PMID:26579520

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

    PubMed Central

    Marré, Meghan L.; James, Eddie A.; Piganelli, Jon D.

    2015-01-01

    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 (APCs) 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. PMID:26579520

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

    PubMed

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

    2016-08-01

    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.

  1. Alleviation of salt stress-induced inhibition of seed germination in cucumber (Cucumis sativus L.) by ethylene and glutamate.

    PubMed

    Chang, Chenshuo; Wang, Baolan; Shi, Lei; Li, Yinxin; Duo, Lian; Zhang, Wenhao

    2010-09-15

    Ethylene is an important plant gas hormone, and the amino acid Glu is emerging as a messenger molecule in plants. To evaluate the role of ethylene and Glu in seed germination and radicle growth under salt stress, effects of 1-aminocyclopropane-1-carboxylic acid (ACC), Ethephon and Glu on germination and radicle growth of cucumber (Cucumis sativus L.) seeds in the absence and presence of 200 mM NaCl were investigated. Seed germination was markedly inhibited by salt stress, and this effect was alleviated by ACC and Ethephon. In contrast to seed germination, ACC and Ethephon had little effect on radicle growth under salt stress. In addition to ethylene, we found exogenous supply of Glu was effective in alleviating the salt stress-induced inhibition of seed germination and radicle growth. The effect of Glu on the seed germination and radicle growth was specific to L-Glu, whereas D-Glu and Gln had no effect. There was an increase in ethylene production during seed imbibition, and salt stress suppressed ethylene production. Exogenous L-Glu evoked ethylene evolution from the imbibed seeds and attenuated the reduction in ethylene evolution induced by salt stress. The alleviative effect of L-Glu on seed germination was diminished by antagonists of ethylene synthesis, aminoethoxyvinylglycine (AVG) and CoCl(2), suggesting that L-Glu is likely to exert its effect on seed germination by modulation of ethylene evolution. These findings demonstrate that ethylene is associated with suppression of seed germination under salt stress and that L-Glu interacts with ethylene in regulation of seed germination under salt stress.

  2. Hrd1 and ER-Associated Protein Degradation, ERAD, Are Critical Elements of the Adaptive ER Stress Response in Cardiac Myocytes

    PubMed Central

    Doroudgar, Shirin; Völkers, Mirko; Thuerauf, Donna J; Khan, Mohsin; Mohsin, Sadia; Respress, Jonathan L; Wang, Wei; Gude, Natalie; Müller, Oliver J; Wehrens, Xander HT; Sussman, Mark A; Glembotski, Christopher C

    2015-01-01

    Rationale Hrd1 is an endoplasmic reticulum (ER)-transmembrane E3 ubiquitin ligase that has been studied in yeast, where it contributes to ER protein quality control by ER-associated degradation (ERAD) of misfolded proteins that accumulate during ER stress. Neither Hrd1 nor ERAD have been studied in the heart, or in cardiac myocytes, where protein quality control is critical for proper heart function. Objective The objectives of this study were to elucidate roles for Hrd1 in ER stress, ERAD, and viability in cultured cardiac myocytes and in the mouse heart, in vivo. Methods and Results The effects of siRNA-mediated Hrd1 knockdown were examined in cultured neonatal rat ventricular myocytes. The effects of adeno-associated virus (AAV)-mediated Hrd1 knockdown and overexpression were examined in the hearts of mice subjected to pressure-overload induced pathological cardiac hypertrophy, which challenges protein-folding capacity. In cardiac myocytes, the ER stressors, thapsigargin (TG) and tunicamycin (TM) increased ERAD, as well as adaptive ER stress proteins, and minimally affected cell death. However, when Hrd1 was knocked down, TG and TM dramatically decreased ERAD, while increasing maladaptive ER stress proteins and cell death. In vivo, Hrd1 knockdown exacerbated cardiac dysfunction, and increased apoptosis and cardiac hypertrophy, while Hrd1 overexpression preserved cardiac function, and decreased apoptosis and attenuated cardiac hypertrophy in the hearts of mice subjected to pressure-overload. Conclusions Hrd1 and ERAD are essential components of the adaptive ER stress response in cardiac myocytes. Hrd1 contributes to preserving heart structure and function in a mouse model of pathological cardiac hypertrophy. PMID:26137860

  3. Exogenous ascorbic acid and glutathione alleviate oxidative stress induced by salt stress in the chloroplasts of Oryza sativa L.

    PubMed

    Wang, Renlei; Liu, Shaohua; Zhou, Feng; Ding, Chunxia; Hua, Chun

    2014-01-01

    The effects of exogenous ascorbic acid (AsA) and reduced glutathione (GSH) on antioxidant enzyme activities [superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR)] and the contents of malondialdehyde (MDA) and H2O2, as well as of endogenous AsA and GSH, in the chloroplasts of two rice cultivars, the salt-tolerant cultivar Pokkali and the salt-sensitive cultivar Peta, were investigated. Exogenous AsA and GSH enhanced SOD, APX, and GR activities, increased endogenous AsA and GSH contents, and reduced those of H2O2 and MDA in the chloroplasts of both cultivars under salt stress (200 mM NaCl), but the effects were significantly more pronounced in cv. Pokkali. GSH acted more strongly than AsA on the plastidial reactive oxygen scavenging systems. These results indicated that exogenous AsA and GSH differentially enhanced salinity tolerance and alleviated salinity-induced damage in the two rice cultivars.

  4. Involvement of ethylene in gibberellic acid-induced sulfur assimilation, photosynthetic responses, and alleviation of cadmium stress in mustard.

    PubMed

    Masood, Asim; Khan, M Iqbal R; Fatma, Mehar; Asgher, Mohd; Per, Tasir S; Khan, Nafees A

    2016-07-01

    The role of gibberellic acid (GA) or sulfur (S) in stimulation of photosynthesis is known. However, information on the involvement of ethylene in GA-induced photosynthetic responses and cadmium (Cd) tolerance is lacking. This work shows that ethylene is involved in S-assimilation, photosynthetic responses and alleviation of Cd stress by GA in mustard (Brassica juncea L.). Plants grown with 200 mg Cd kg(-1) soil were less responsive to ethylene despite high ethylene evolution and showed photosynthetic inhibition. Plants receiving 10 μM GA spraying plus 100 mg S kg(-1) soil supplementation exhibited increased S-assimilation and photosynthetic responses under Cd stress. Application of GA plus S decreased oxidative stress of plants grown with Cd and limited stress ethylene formation to the range suitable for promoting sulfur use efficiency (SUE), glutathione (GSH) production and photosynthesis. The role of ethylene in GA-induced S-assimilation and reversal of photosynthetic inhibition by Cd was substantiated by inhibiting ethylene biosynthesis with the use of aminoethoxyvinylglycine (AVG). The suppression of S-assimilation and photosynthetic responses by inhibiting ethylene in GA plus S treated plants under Cd stress indicated the involvement of ethylene in GA-induced S-assimilation and Cd stress alleviation. The outcome of the study is important to unravel the interaction between GA and ethylene and their role in Cd tolerance in plants. PMID:26998941

  5. Involvement of ethylene in gibberellic acid-induced sulfur assimilation, photosynthetic responses, and alleviation of cadmium stress in mustard.

    PubMed

    Masood, Asim; Khan, M Iqbal R; Fatma, Mehar; Asgher, Mohd; Per, Tasir S; Khan, Nafees A

    2016-07-01

    The role of gibberellic acid (GA) or sulfur (S) in stimulation of photosynthesis is known. However, information on the involvement of ethylene in GA-induced photosynthetic responses and cadmium (Cd) tolerance is lacking. This work shows that ethylene is involved in S-assimilation, photosynthetic responses and alleviation of Cd stress by GA in mustard (Brassica juncea L.). Plants grown with 200 mg Cd kg(-1) soil were less responsive to ethylene despite high ethylene evolution and showed photosynthetic inhibition. Plants receiving 10 μM GA spraying plus 100 mg S kg(-1) soil supplementation exhibited increased S-assimilation and photosynthetic responses under Cd stress. Application of GA plus S decreased oxidative stress of plants grown with Cd and limited stress ethylene formation to the range suitable for promoting sulfur use efficiency (SUE), glutathione (GSH) production and photosynthesis. The role of ethylene in GA-induced S-assimilation and reversal of photosynthetic inhibition by Cd was substantiated by inhibiting ethylene biosynthesis with the use of aminoethoxyvinylglycine (AVG). The suppression of S-assimilation and photosynthetic responses by inhibiting ethylene in GA plus S treated plants under Cd stress indicated the involvement of ethylene in GA-induced S-assimilation and Cd stress alleviation. The outcome of the study is important to unravel the interaction between GA and ethylene and their role in Cd tolerance in plants.

  6. Isolation and characterization of ACC deaminase-producing fluorescent pseudomonads, to alleviate salinity stress on canola (Brassica napus L.) growth.

    PubMed

    Jalili, Farzad; Khavazi, Kazem; Pazira, Ebrahim; Nejati, Alireza; Rahmani, Hadi Asadi; Sadaghiani, Hasan Rasuli; Miransari, Mohammad

    2009-04-01

    Salinity stress is of great importance in arid and semi-arid areas of the world due to its impact in reducing crop yield. Under salinity stress, the amount of 1-aminocyclopropane-1-carboxylate (ACC), a precursor for ethylene production in plants, increases. Here, we conducted research under the hypothesis that isolated ACC deaminase-producing Pseudomonas fluorescens and Pseudomonas putida can alleviate the stressful effects of salinity on canola (Brassica napus L.) growth. The experiments were conducted in the Soil and Water Research Institute, Tehran, Iran. Seven experimental stages were conducted to isolate and characterize ACC deaminase-producing Pseudomonas fluorescens strains and to determine factors enhancing their growth and, consequently, their effects on the germination of canola seeds. Under salinity stress, in 14% of the isolates, ACC deaminase activity was observed, indicating that they were able to utilize ACC as the sole N-source. Bacterial strains differed in their ability to synthesize auxin and hydrogen cyanide compounds, as well as in their ACC deaminase activity. Under salinity stress, the rate of germinating seeds inoculated with the strains of ACC deaminase-producing Pseudomonas fluorescens and Pseudomonas putida, and seedling growth was significantly higher. These results indicate the significance of soil biological activities, including the activities of plant growth-promoting bacteria, in the alleviation of soil stresses such as salinity on plant growth.

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

    PubMed Central

    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

  8. Protein kinase R-like ER kinase and its role in endoplasmic reticulum stress-decided cell fate

    PubMed Central

    Liu, Z; Lv, Y; Zhao, N; Guan, G; Wang, J

    2015-01-01

    Over the past few decades, understandings and evidences concerning the role of endoplasmic reticulum (ER) stress in deciding the cell fate have been constantly growing. Generally, during ER stress, the signal transductions are mainly conducted by three ER stress transducers: protein kinase R-like endoplasmic reticulum kinase (PERK), inositol-requiring kinase 1 (IRE1) and activating transcription factor 6 (ATF6). Consequently, the harmful stimuli from the ER stress transducers induce apoptosis and autophagy, which share several crosstalks and eventually decide the cell fate. The dominance of apoptosis or autophagy induced by ER stress depends on the type and degree of the stimuli. When ER stress is too severe and prolonged, apoptosis is induced to eliminate the damaged cells; however, when stimuli are mild, cell survival is promoted to maintain normal physiological functions by inducing autophagy. Although all the three pathways participate in ER stress-induced apoptosis and autophagy, PERK shows several unique characteristics by interacting with some specific downstream effectors. Notably, there are some preliminary findings on PERK-dependent mechanisms switching autophagy and apoptosis. In this review, we particularly focused on the novel, intriguing and complicated role of PERK in ER stress-decided cell fate, and also discussed more roles of PERK in restoring cellular homeostasis. However, more in-depth knowledge of PERK in the future would facilitate our understanding about many human diseases and benefit in searching for new molecular therapeutic targets. PMID:26225772

  9. ATF6 upregulates XBP1S and inhibits ER stress-mediated apoptosis in osteoarthritis cartilage.

    PubMed

    Guo, Feng-Jin; Xiong, Zhangyuan; Lu, Xiaojie; Ye, Mengliang; Han, Xiaofeng; Jiang, Rong

    2014-02-01

    As we previously reported, transcription factor XBP1S enhances BMP2-induced chondrocyte differentiation and acts as a positive mediator of chondrocyte hypertrophy. The purpose of this study was to determine (1) whether XBP1S influences ER stress-mediated apoptosis in osteoarthritis (OA); (2) whether ATF6 regulates IRE1/XBP1 signal pathway in OA cartilage; (3) what are the associated molecules affecting apoptosis in osteoarthritis and the molecular events underlying this process. Herein, we examined and found that ER stress-associated molecules were activated in OA patients, specifically XBP1S splice and expression were increased markedly by TNF-α and IL-1β treatments. Transcription factor ATF6 can specifically bind to the promoter of XBP1 gene and enhance the expression of XBP1S spliced by IRE1α in osteoarthritis cartilage. Furthermore, siXBP1S can enhance ER stress-mediated apoptosis and main matrix degradation in osteoarthritis. Whereas AdXBP1S can inhibit ER stress-mediated apoptosis and TNFα induced nitrite production in OA cartilage. In a word, our observations demonstrate the importance of XBP1S in osteoarthritis. ATF6 and IRE1α can regulate endogenous XBP1S gene expression synergistically in OA cartilage. More significantly, XBP1S was a negative regulator of apoptosis in osteoarthritis by affecting caspase 3, caspase 9, caspase 12, p-JNK1, and CHOP.

  10. Activation of HIPK2 Promotes ER Stress-Mediated Neurodegeneration in Amyotrophic Lateral Sclerosis.

    PubMed

    Lee, Sebum; Shang, Yulei; Redmond, Stephanie A; Urisman, Anatoly; Tang, Amy A; Li, Kathy H; Burlingame, Alma L; Pak, Ryan A; Jovičić, Ana; Gitler, Aaron D; Wang, Jinhua; Gray, Nathanael S; Seeley, William W; Siddique, Teepu; Bigio, Eileen H; Lee, Virginia M-Y; Trojanowski, John Q; Chan, Jonah R; Huang, Eric J

    2016-07-01

    Persistent accumulation of misfolded proteins causes endoplasmic reticulum (ER) stress, a prominent feature in many neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Here we report the identification of homeodomain interacting protein kinase 2 (HIPK2) as the essential link that promotes ER-stress-induced cell death via the IRE1α-ASK1-JNK pathway. ER stress, induced by tunicamycin or SOD1(G93A), activates HIPK2 by phosphorylating highly conserved serine and threonine residues (S359/T360) within the activation loop of the HIPK2 kinase domain. In SOD1(G93A) mice, loss of HIPK2 delays disease onset, reduces cell death in spinal motor neurons, mitigates glial pathology, and improves survival. Remarkably, HIPK2 activation positively correlates with TDP-43 proteinopathy in NEFH-tTA/tetO-hTDP-43ΔNLS mice, sporadic ALS and C9ORF72 ALS, and blocking HIPK2 kinase activity protects motor neurons from TDP-43 cytotoxicity. These results reveal a previously unrecognized role of HIPK2 activation in ER-stress-mediated neurodegeneration and its potential role as a biomarker and therapeutic target for ALS. VIDEO ABSTRACT.

  11. Progesterone exerts neuroprotective effects against Aβ-induced neuroinflammation by attenuating ER stress in astrocytes.

    PubMed

    Hong, Yang; Wang, Xiaomin; Sun, Shuang; Xue, Gai; Li, Jianli; Hou, Yanning

    2016-04-01

    The deposition of amyloid-β (Aβ) and neuroinflammation are critical pathological features of Alzheimer's disease (AD). Astrocytes are considered the principal immunoregulatory cells in the brain. Neurosteroid progesterone (PG) exerts neuromodulatory properties, particularly its potential therapeutic function in ameliorating AD. However, the role of PG and the neuroprotective mechanism involving in the regulation of neuroinflammation in astrocytes warrant further investigation. In this study, we found that Aβ significantly increased the processing of neuroinflammatory responses in astrocytes. The processing is induced by an increase activity of PERK/elF2ɑ-dependent endoplasmic reticulum (ER) stress. Additionally, the inhibition of ER stress activation by Salubrinal significantly suppressed the Aβ-induced neuroinflammatory responses in astrocytes. While the treatment of astrocytes with Aβ caused an increase of neuroinflammatory responses, PG significantly inhibited Aβ-induced neuroinflammatory cytokine production by suppressing ER stress activation together with attenuating PERK/elF2ɑ signalling. Taken together, these results indicate that PG exerts a neuroprotective effect against Aβ-induced neuroinflammatory responses, and significantly suppresses ER stress activation, which is an important mediator of the neurotoxic events occurring in Aβ-induced neuroinflammatory responses in astrocytes. These neuroprotective mechanisms may facilitate the development of therapies to ameliorate AD. PMID:26878478

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

    PubMed Central

    Kania, Elżbieta; Pająk, Beata

    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 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. PMID:25821797

  13. Pharmacologic ER Stress Induces Non-alcoholic Steatohepatitis in an Animal Model

    PubMed Central

    Lee, Jin-Sook; Zheng, Ze; Mendez, Roberto; Ha, Seung-Wook; Xie, Youming; Zhang, Kezhong

    2012-01-01

    Endoplasmic reticulum (ER) stress refers to a condition of accumulation of unfolded or misfolded proteins in the ER lumen, which is known to activate an intracellular stress signaling termed Unfolded Protein Response (UPR). A number of pharmacologic reagents or pathophysiologic stimuli can induce ER stress and activation of the UPR signaling, leading to alteration of cell physiology that is associated with the initiation and progression of a variety of diseases. Non-alcoholic steatohepatitis (NASH), characterized by hepatic steatosis and inflammation, has been considered the precursor or the hepatic manifestation of metabolic disease. In this study, we delineated the toxic effect and molecular basis by which pharmacologic ER stress, induced by a bacterial nucleoside antibiotic tunicamycin (TM), promotes NASH in an animal model. Mice of C57BL/6J strain background were challenged with pharmacologic ER stress by intraperitoneal injection of TM. Upon TM injection, mice exhibited a quick NASH state characterized by hepatic steatosis and inflammation. An increase in hepatic triglycerides (TG) and a decrease in plasma lipids, including plasma TG, plasma cholesterol, high-density lipoprotein (HDL), and low-density lipoprotein (LDL), were observed in the TM-treated mice. In response to TM challenge, cleavage of sterol responsive binding protein (SREBP)-1a and SREBP-1c, the key trans-activators for lipid and sterol biosynthesis, was dramatically increased in the liver. Consistent with the hepatic steatosis phenotype, expression of some key regulators and enzymes in de novo lipogenesis and lipid droplet formation was up-regulated, while expression of those involved in lipolysis and fatty acid oxidation was down-regulated in the liver of mice challenged with TM. Moreover, TM treatment significantly increased phosphorylation of NF-κB inhibitors (IκB), leading to the activation of NF-κB-mediated inflammatory pathway in the liver. Our study not only confirmed that

  14. TULP1 Missense Mutations Induces the Endoplasmic Reticulum Unfolded Protein Response Stress Complex (ER-UPR).

    PubMed

    Lobo, Glenn P; Ebke, Lindsey A; Au, Adrian; Hagstrom, Stephanie A

    2016-01-01

    Mutations in the TULP1 gene are associated with early-onset retinitis pigmentosa (RP); however, the molecular mechanisms related to the deleterious effects of TULP1 mutations remains unknown. Several studies have shown that misfolded proteins secondary to genetic mutations can accumulate within the endoplasmic reticulum (ER), causing activation of the unfolded protein response (UPR) complex followed by cellular apoptosis. We hypothesize that TULP1 mutations produce misfolded protein products that accumulate in the ER and induce cellular apoptosis via the UPR. To test our hypothesis, we first performed three in-silico analyses of TULP1 missense mutations (I459K, R420P and F491L), which predicted misfolded protein products. Subsequently, the three mutant TULP1-GFP constructs and wild-type (wt) TULP1-GFP were transiently transfected into hTERT-RPE-1 cells. Staining of cells using ER tracker followed by confocal microscopy showed wt-TULP1 localized predominantly to the cytoplasm and plasma membrane. In contrast, all three mutant TULP1 proteins revealed cytoplasmic punctate staining which co-localized with the ER. Furthermore, western blot analysis of cells expressing mutant TULP1 proteins revealed induction of downstream targets of the ER-UPR complex, including BiP/GPR-78, phosphorylated-PERK (Thr980) and CHOP. Our in-vitro analyses suggest that mutant TULP1 proteins are misfolded and accumulate within the ER leading to induction of the UPR stress response complex. PMID:26427415

  15. Disrupted autophagy after spinal cord injury is associated with ER stress and neuronal cell death

    PubMed Central

    Liu, S; Sarkar, C; Dinizo, M; Faden, A I; Koh, E Y; Lipinski, M M; Wu, J

    2015-01-01

    Autophagy is a catabolic mechanism facilitating degradation of cytoplasmic proteins and organelles in a lysosome-dependent manner. Autophagy flux is necessary for normal neuronal homeostasis and its dysfunction contributes to neuronal cell death in several neurodegenerative diseases. Elevated autophagy has been reported after spinal cord injury (SCI); however, its mechanism, cell type specificity and relationship to cell death are unknown. Using a rat model of contusive SCI, we observed accumulation of LC3-II-positive autophagosomes starting at posttrauma day 1. This was accompanied by a pronounced accumulation of autophagy substrate protein p62, indicating that early elevation of autophagy markers reflected disrupted autophagosome degradation. Levels of lysosomal protease cathepsin D and numbers of cathepsin-D-positive lysosomes were also decreased at this time, suggesting that lysosomal damage may contribute to the observed defect in autophagy flux. Normalization of p62 levels started by day 7 after SCI, and was associated with increased cathepsin D levels. At day 1 after SCI, accumulation of autophagosomes was pronounced in ventral horn motor neurons and dorsal column oligodendrocytes and microglia. In motor neurons, disruption of autophagy strongly correlated with evidence of endoplasmic reticulum (ER) stress. As autophagy is thought to protect against ER stress, its disruption after SCI could contribute to ER-stress-induced neuronal apoptosis. Consistently, motor neurons showing disrupted autophagy co-expressed ER-stress-associated initiator caspase 12 and cleaved executioner caspase 3. Together, these findings indicate that SCI causes lysosomal dysfunction that contributes to autophagy disruption and associated ER-stress-induced neuronal apoptosis. PMID:25569099

  16. Iron depletion increases manganese uptake and potentiates apoptosis through ER stress.

    PubMed

    Seo, Young Ah; Li, Yuan; Wessling-Resnick, Marianne

    2013-09-01

    Iron deficiency is a risk factor for manganese (Mn) accumulation. Excess Mn promotes neurotoxicity but the mechanisms involved and whether iron depletion might affect these pathways is unknown. To study Mn intoxication in vivo, iron deficient and control rats were intranasally instilled with 60mg MnCl2/kg over 3 weeks. TUNEL staining of olfactory tissue revealed that Mn exposure induced apoptosis and that iron deficiency potentiated this effect. In vitro studies using the dopaminergic SH-SY5Y cell line confirmed that Mn-induced apoptosis was enhanced by iron depletion using the iron chelator desferrioxamine. Mn has been reported to induce apoptosis through endoplasmic reticulum stress. In SH-SY5Y cells, Mn exposure induced the ER stress genes glucose regulated protein 94 (GRP94) and C/EBP homologous protein (CHOP). Increased phosphorylation of the eukaryotic translation initiation factor 2α (phospho-eIF2α) was also observed. These effects were accompanied by the activation of ER resident enzyme caspase-12, and the downstream apoptotic effector caspase-3 was also activated. All of the Mn-induced responses were enhanced by DFO treatment. Inhibitors of ER stress and caspases significantly blocked Mn-induced apoptosis and its potentiation by DFO, indicating that ER stress and subsequent caspase activation underlie cell death. Taken together, these data reveal that Mn induces neuronal cell death through ER stress and the UPR response pathway and that this apoptotic effect is potentiated by iron deficiency most likely through upregulation of DMT1. PMID:23764342

  17. Carbon dioxide enrichment alleviates heat stress by improving cellular redox homeostasis through an ABA-independent process in tomato plants.

    PubMed

    Li, X; Ahammed, G J; Zhang, Y Q; Zhang, G Q; Sun, Z H; Zhou, J; Zhou, Y H; Xia, X J; Yu, J Q; Shi, K

    2015-01-01

    Plant responses to elevated CO₂ and high temperature are critically regulated through a complex network of phytohormones and redox homeostasis. However, the involvement of abscisic acid (ABA) in plant adaptation to heat stress under elevated CO₂ conditions has not been thoroughly studied. This study investigated the interactive effects of elevated CO₂ (800 μmol·mol(-1) ) and heat stress (42 °C for 24 h) on the endogenous level of ABA and the cellular redox state of two genotypes of tomato with different ABA biosynthesis capacities. Heat stress significantly decreased maximum photochemical efficiency of PSII (Fv/Fm) and leaf water potential, but also increased levels of malondialdehyde (MDA) and electrolyte leakage (EL) in both genotypes. Heat-induced damage was more severe in the ABA-deficient mutant notabilis (not) than in its parental cultivar Ailsa Craig (Ailsa), suggesting that a certain level of endogenous ABA is required to minimise the heat-induced oxidative damage to the photosynthetic apparatus. Irrespective of genotype, the enrichment of CO₂ remarkably stimulated Fv/Fm, MDA and EL in heat-stressed plants towards enhanced tolerance. In addition, elevated CO₂ significantly strengthened the antioxidant capacity of heat-stressed tomato seedlings towards a reduced cellular redox state for a prolonged period, thereby mitigating oxidative stress. However, elevated CO₂ and heat stress did not alter the endogenous level of ABA or the expression of its biosynthetic gene NCED2 in either genotype, indicating that ABA is not involved in elevated CO₂ -induced heat stress alleviation. The results of this study suggest that elevated CO₂ alleviated heat stress through efficient regulation of the cellular redox poise in an ABA-independent manner in tomato plants.

  18. Yeast Culture and Vitamin E Supplementation Alleviates Heat Stress in Dairy Goats.

    PubMed

    Wang, Lizhi; Wang, Zhisheng; Zou, Huawei; Peng, Quanhui

    2016-06-01

    This study was conducted to determine and compare the effects of yeast yeast culture (YC) and vitamin E (VE) supplementation on endotoxin absorption and antioxidant status in lactating dairy goats suffering from heat stress (HS). Three first lactation Saanen dairy goats (body weight 30±1.5 kg) were surgically fitted with indwelling catheters in the portal vein, mesenteric vein and carotid artery, and were randomly assigned to a 3×3 Latin square design. Dietary treatments were the basal diet, and the basal diet supplemented with either 100 IU VE or 30 g YC. Goats were kept in temperature and humidity-controlled room at 35°C from 8:00 to 20:00 and at 24°C from 20:00 till the next morning at 8:00. The relative humidity was kept at 55%. HS increased dairy goats' rectum temperature and respiration frequency (p<0.01). HS reduced plasma flux rate of milk goats (p<0.01), but the plasma flux rate increased when the animal was under the conditions of the thermo-neutral period (p<0.01). The VE supplementation lowered dairy goats' rectum temperature during thermo-neutral period (p<0.01). Meanwhile, no significant differences were observed between the control and YC treatment in rectum temperature and respiration frequency (p>0.05). Dietary supplementation of VE and YC reduced heat stressed dairy goats' endotoxin concentration of the carotid artery and portal vein (p<0.01). However, the endotoxin concentration of the YC treatment was higher than that of the VE treatment (p<0.01). Both VE and YC supplementation decreased heat stressed dairy goats' absorption of endotoxin in portal vein (p<0.01). The endotoxin absorption of YC treatment was higher than the VE treatment (p<0.01). The addition of VE and YC decreased dairy goats' superoxide dismutase (SOD) concentration during HS and the whole experiment period (p<0.01). The addition of VE lowered SOD concentration during thermo-neutral period (p<0.01). Likewise, the addition of VE and YC lowered dairy goats' malonaldehyde (MDA

  19. Yeast Culture and Vitamin E Supplementation Alleviates Heat Stress in Dairy Goats.

    PubMed

    Wang, Lizhi; Wang, Zhisheng; Zou, Huawei; Peng, Quanhui

    2016-06-01

    This study was conducted to determine and compare the effects of yeast yeast culture (YC) and vitamin E (VE) supplementation on endotoxin absorption and antioxidant status in lactating dairy goats suffering from heat stress (HS). Three first lactation Saanen dairy goats (body weight 30±1.5 kg) were surgically fitted with indwelling catheters in the portal vein, mesenteric vein and carotid artery, and were randomly assigned to a 3×3 Latin square design. Dietary treatments were the basal diet, and the basal diet supplemented with either 100 IU VE or 30 g YC. Goats were kept in temperature and humidity-controlled room at 35°C from 8:00 to 20:00 and at 24°C from 20:00 till the next morning at 8:00. The relative humidity was kept at 55%. HS increased dairy goats' rectum temperature and respiration frequency (p<0.01). HS reduced plasma flux rate of milk goats (p<0.01), but the plasma flux rate increased when the animal was under the conditions of the thermo-neutral period (p<0.01). The VE supplementation lowered dairy goats' rectum temperature during thermo-neutral period (p<0.01). Meanwhile, no significant differences were observed between the control and YC treatment in rectum temperature and respiration frequency (p>0.05). Dietary supplementation of VE and YC reduced heat stressed dairy goats' endotoxin concentration of the carotid artery and portal vein (p<0.01). However, the endotoxin concentration of the YC treatment was higher than that of the VE treatment (p<0.01). Both VE and YC supplementation decreased heat stressed dairy goats' absorption of endotoxin in portal vein (p<0.01). The endotoxin absorption of YC treatment was higher than the VE treatment (p<0.01). The addition of VE and YC decreased dairy goats' superoxide dismutase (SOD) concentration during HS and the whole experiment period (p<0.01). The addition of VE lowered SOD concentration during thermo-neutral period (p<0.01). Likewise, the addition of VE and YC lowered dairy goats' malonaldehyde (MDA

  20. Yeast Culture and Vitamin E Supplementation Alleviates Heat Stress in Dairy Goats

    PubMed Central

    Wang, Lizhi; Wang, Zhisheng; Zou, Huawei; Peng, Quanhui

    2016-01-01

    This study was conducted to determine and compare the effects of yeast yeast culture (YC) and vitamin E (VE) supplementation on endotoxin absorption and antioxidant status in lactating dairy goats suffering from heat stress (HS). Three first lactation Saanen dairy goats (body weight 30±1.5 kg) were surgically fitted with indwelling catheters in the portal vein, mesenteric vein and carotid artery, and were randomly assigned to a 3×3 Latin square design. Dietary treatments were the basal diet, and the basal diet supplemented with either 100 IU VE or 30 g YC. Goats were kept in temperature and humidity-controlled room at 35°C from 8:00 to 20:00 and at 24°C from 20:00 till the next morning at 8:00. The relative humidity was kept at 55%. HS increased dairy goats’ rectum temperature and respiration frequency (p<0.01). HS reduced plasma flux rate of milk goats (p<0.01), but the plasma flux rate increased when the animal was under the conditions of the thermo-neutral period (p<0.01). The VE supplementation lowered dairy goats’ rectum temperature during thermo-neutral period (p<0.01). Meanwhile, no significant differences were observed between the control and YC treatment in rectum temperature and respiration frequency (p>0.05). Dietary supplementation of VE and YC reduced heat stressed dairy goats’ endotoxin concentration of the carotid artery and portal vein (p<0.01). However, the endotoxin concentration of the YC treatment was higher than that of the VE treatment (p<0.01). Both VE and YC supplementation decreased heat stressed dairy goats’ absorption of endotoxin in portal vein (p<0.01). The endotoxin absorption of YC treatment was higher than the VE treatment (p<0.01). The addition of VE and YC decreased dairy goats’ superoxide dismutase (SOD) concentration during HS and the whole experiment period (p<0.01). The addition of VE lowered SOD concentration during thermo-neutral period (p<0.01). Likewise, the addition of VE and YC lowered dairy goats

  1. Pea lectin receptor-like kinase functions in salinity adaptation without yield penalty, by alleviating osmotic and ionic stresses and upregulating stress-responsive genes.

    PubMed

    Vaid, Neha; Pandey, Prashant; Srivastava, Vineet Kumar; Tuteja, Narendra

    2015-05-01

    Lectin receptor-like kinases (LecRLKs) are members of RLK family composed of lectin-like extracellular recognition domain, transmembrane domain and cytoplasmic kinase domain. LecRLKs are plasma membrane proteins believed to be involved in signal transduction. However, most of the members of the protein family even in plants have not been functionally well characterized. Herein, we show that Pisum sativum LecRLK (PsLecRLK) localized in plasma membrane systems and/or other regions of the cell and its transcript upregulated under salinity stress. Overexpression of PsLecRLK in transgenic tobacco plants confers salinity stress tolerance by alleviating both the ionic as well the osmotic component of salinity stress. The transgenic plants show better tissue compartmentalization of Na(+) and higher ROS scavenging activity which probably results in lower membrane damage, improved growth and yield maintenance even under salinity stress. Also, expression of several genes involved in cellular homeostasis is perturbed by PsLecRLK overexpression. Alleviation of osmotic and ionic components of salinity stress along with reduced oxidative damage and upregulation of stress-responsive genes in transgenic plants under salinity stress conditions could be possible mechanism facilitating enhanced stress tolerance. This study presents PsLecRLK as a promising candidate for crop improvement and also opens up new avenue to investigate its signalling pathway.

  2. Intrarenal renin-angiotensin system mediates fatty acid-induced ER stress in the kidney.

    PubMed

    Li, Chunling; Lin, Yu; Luo, Renfei; Chen, Shaoming; Wang, Feifei; Zheng, Peili; Levi, Moshe; Yang, Tianxin; Wang, Weidong

    2016-03-01

    Obesity-related kidney disease is related to caloric excess promoting deleterious cellular responses. Accumulation of saturated free fatty acids in tubular cells produces lipotoxicity involving significant cellular dysfunction and injury. The objectives of this study were to elucidate the role of renin-angiotensin system (RAS) activation in saturated fatty acid-induced endoplasmic reticulum (ER) stress in cultured human proximal tubule epithelial cells (HK2) and in mice fed with a high-fat diet. Treatment with saturated fatty acid palmitic acid (PA; 0.8 mM) for 24 h induced ER stress in HK2, leading to an unfolded protein response as reflected by increased expressions of the ER chaperone binding immunoglobulin protein (BiP) and proapoptotic transcription factor C/EBP homologous protein (CHOP) protein as evaluated by immunoblotting. PA treatment also induced increased protein expression of inositol requiring protein 1α (IRE1α), phosphorylated eukaryotic initiation factor-α (eIF2α), and activating transcription factor 4 (ATF4) as well as activation of caspase-3. PA treatment was associated with increased angiotensin II levels in cultured medium. The angiotensin II type 1 receptor (AT1R) blocker valsartan or renin inhibitor aliskiren dramatically suppressed PA-induced upregulation of BiP, CHOP, IRE1α, p-eIF2α, and ATF4 in HK2 cells. In contrast, valsartan or aliskiren did not prevent ER stress induced by tunicamycin. C57BL/6 mice fed with a high-fat diet for 14 wk exhibited increased protein expressions of BiP and CHOP compared with control mice, which were significantly attenuated by the valsartan treatment. Increased angiotensin II levels in serum and urine were observed in mice fed with a high-fat diet when compared with controls. It is suggested that the intrarenal RAS activation may play an important role in diabetic kidney injury via mediating ER stress induced by saturated fatty acid. PMID:26672616

  3. Deficiency in the mitochondrial apoptotic pathway reveals the toxic potential of autophagy under ER stress conditions

    PubMed Central

    Deegan, Shane; Saveljeva, Svetlana; Logue, Susan E; Pakos-Zebrucka, Karolina; Gupta, Sanjeev; Vandenabeele, Peter; Bertrand, Mathieu JM; Samali, Afshin

    2014-01-01

    Endoplasmic reticulum (ER) stress-induced cell death is normally associated with activation of the mitochondrial apoptotic pathway, which is characterized by CYCS (cytochrome c, somatic) release, apoptosome formation, and caspase activation, resulting in cell death. In this study, we demonstrate that under conditions of ER stress cells devoid of CASP9/caspase-9 or BAX and BAK1, and therefore defective in the mitochondrial apoptotic pathway, still undergo a delayed form of cell death associated with the activation of caspases, therefore revealing the existence of an alternative stress-induced caspase activation pathway. We identified CASP8/caspase-8 as the apical protease in this caspase cascade, and found that knockdown of either of the key autophagic genes, ATG5 or ATG7, impacted on CASP8 activation and cell death induction, highlighting the crucial role of autophagy in the activation of this novel ER stress-induced death pathway. In line with this, we identified a protein complex composed of ATG5, FADD, and pro-CASP8 whose assembly coincides with caspase activation and cell death induction. Together, our results reveal the toxic potential of autophagy in cells undergoing ER stress that are defective in the mitochondrial apoptotic pathway, and suggest a model in which the autophagosome functions as a platform facilitating pro-CASP8 activation. Chemoresistance, a common problem in the treatment of cancer, is frequently caused by the downregulation of key mitochondrial death effector proteins. Alternate stress-induced apoptotic pathways, such as the one described here, may become of particular relevance for tackling the problem of chemoresistance in cancer cells. PMID:25470234

  4. Deficiency in the mitochondrial apoptotic pathway reveals the toxic potential of autophagy under ER stress conditions.

    PubMed

    Deegan, Shane; Saveljeva, Svetlana; Logue, Susan E; Pakos-Zebrucka, Karolina; Gupta, Sanjeev; Vandenabeele, Peter; Bertrand, Mathieu J M; Samali, Afshin

    2014-01-01

    Endoplasmic reticulum (ER) stress-induced cell death is normally associated with activation of the mitochondrial apoptotic pathway, which is characterized by CYCS (cytochrome c, somatic) release, apoptosome formation, and caspase activation, resulting in cell death. In this study, we demonstrate that under conditions of ER stress cells devoid of CASP9/caspase-9 or BAX and BAK1, and therefore defective in the mitochondrial apoptotic pathway, still undergo a delayed form of cell death associated with the activation of caspases, therefore revealing the existence of an alternative stress-induced caspase activation pathway. We identified CASP8/caspase-8 as the apical protease in this caspase cascade, and found that knockdown of either of the key autophagic genes, ATG5 or ATG7, impacted on CASP8 activation and cell death induction, highlighting the crucial role of autophagy in the activation of this novel ER stress-induced death pathway. In line with this, we identified a protein complex composed of ATG5, FADD, and pro-CASP8 whose assembly coincides with caspase activation and cell death induction. Together, our results reveal the toxic potential of autophagy in cells undergoing ER stress that are defective in the mitochondrial apoptotic pathway, and suggest a model in which the autophagosome functions as a platform facilitating pro-CASP8 activation. Chemoresistance, a common problem in the treatment of cancer, is frequently caused by the downregulation of key mitochondrial death effector proteins. Alternate stress-induced apoptotic pathways, such as the one described here, may become of particular relevance for tackling the problem of chemoresistance in cancer cells.

  5. Deficiency in the mitochondrial apoptotic pathway reveals the toxic potential of autophagy under ER stress conditions.

    PubMed

    Deegan, Shane; Saveljeva, Svetlana; Logue, Susan E; Pakos-Zebrucka, Karolina; Gupta, Sanjeev; Vandenabeele, Peter; Bertrand, Mathieu J M; Samali, Afshin

    2014-01-01

    Endoplasmic reticulum (ER) stress-induced cell death is normally associated with activation of the mitochondrial apoptotic pathway, which is characterized by CYCS (cytochrome c, somatic) release, apoptosome formation, and caspase activation, resulting in cell death. In this study, we demonstrate that under conditions of ER stress cells devoid of CASP9/caspase-9 or BAX and BAK1, and therefore defective in the mitochondrial apoptotic pathway, still undergo a delayed form of cell death associated with the activation of caspases, therefore revealing the existence of an alternative stress-induced caspase activation pathway. We identified CASP8/caspase-8 as the apical protease in this caspase cascade, and found that knockdown of either of the key autophagic genes, ATG5 or ATG7, impacted on CASP8 activation and cell death induction, highlighting the crucial role of autophagy in the activation of this novel ER stress-induced death pathway. In line with this, we identified a protein complex composed of ATG5, FADD, and pro-CASP8 whose assembly coincides with caspase activation and cell death induction. Together, our results reveal the toxic potential of autophagy in cells undergoing ER stress that are defective in the mitochondrial apoptotic pathway, and suggest a model in which the autophagosome functions as a platform facilitating pro-CASP8 activation. Chemoresistance, a common problem in the treatment of cancer, is frequently caused by the downregulation of key mitochondrial death effector proteins. Alternate stress-induced apoptotic pathways, such as the one described here, may become of particular relevance for tackling the problem of chemoresistance in cancer cells. PMID:25470234

  6. Genome-wide screen identifies a novel p97/CDC-48-dependent pathway regulating ER-stress-induced gene transcription.

    PubMed

    Marza, Esther; Taouji, Saïd; Barroso, Kim; Raymond, Anne-Aurélie; Guignard, Léo; Bonneu, Marc; Pallares-Lupon, Néstor; Dupuy, Jean-William; Fernandez-Zapico, Martin E; Rosenbaum, Jean; Palladino, Francesca; Dupuy, Denis; Chevet, Eric

    2015-03-01

    The accumulation of misfolded proteins in the endoplasmic reticulum (ER) activates the Unfolded Protein Response (UPR(ER)) to restore ER homeostasis. The AAA(+) ATPase p97/CDC-48 plays key roles in ER stress by promoting both ER protein degradation and transcription of UPR(ER) genes. Although the mechanisms associated with protein degradation are now well established, the molecular events involved in the regulation of gene transcription by p97/CDC-48 remain unclear. Using a reporter-based genome-wide RNAi screen in combination with quantitative proteomic analysis in Caenorhabditis elegans, we have identified RUVB-2, a AAA(+) ATPase, as a novel repressor of a subset of UPR(ER) genes. We show that degradation of RUVB-2 by CDC-48 enhances expression of ER stress response genes through an XBP1-dependent mechanism. The functional interplay between CDC-48 and RUVB-2 in controlling transcription of select UPR(ER) genes appears conserved in human cells. Together, these results describe a novel role for p97/CDC-48, whereby its role in protein degradation is integrated with its role in regulating expression of ER stress response genes.

  7. Genome-wide screen identifies a novel p97/CDC-48-dependent pathway regulating ER-stress-induced gene transcription.

    PubMed

    Marza, Esther; Taouji, Saïd; Barroso, Kim; Raymond, Anne-Aurélie; Guignard, Léo; Bonneu, Marc; Pallares-Lupon, Néstor; Dupuy, Jean-William; Fernandez-Zapico, Martin E; Rosenbaum, Jean; Palladino, Francesca; Dupuy, Denis; Chevet, Eric

    2015-03-01

    The accumulation of misfolded proteins in the endoplasmic reticulum (ER) activates the Unfolded Protein Response (UPR(ER)) to restore ER homeostasis. The AAA(+) ATPase p97/CDC-48 plays key roles in ER stress by promoting both ER protein degradation and transcription of UPR(ER) genes. Although the mechanisms associated with protein degradation are now well established, the molecular events involved in the regulation of gene transcription by p97/CDC-48 remain unclear. Using a reporter-based genome-wide RNAi screen in combination with quantitative proteomic analysis in Caenorhabditis elegans, we have identified RUVB-2, a AAA(+) ATPase, as a novel repressor of a subset of UPR(ER) genes. We show that degradation of RUVB-2 by CDC-48 enhances expression of ER stress response genes through an XBP1-dependent mechanism. The functional interplay between CDC-48 and RUVB-2 in controlling transcription of select UPR(ER) genes appears conserved in human cells. Together, these results describe a novel role for p97/CDC-48, whereby its role in protein degradation is integrated with its role in regulating expression of ER stress response genes. PMID:25652260

  8. Regulation of the transcriptome by ER stress: non-canonical mechanisms and physiological consequences

    PubMed Central

    Arensdorf, Angela M.; Diedrichs, Danilo; Rutkowski, D. Thomas

    2013-01-01

    The mammalian unfolded protein response (UPR) is propagated by three ER-resident transmembrane proteins, each of which initiates a signaling cascade that ultimately culminates in production of a transcriptional activator. The UPR was originally characterized as a pathway for upregulating ER chaperones, and a comprehensive body of subsequent work has shown that protein synthesis, folding, oxidation, trafficking, and degradation are all transcriptionally enhanced by the UPR. However, the global reach of the UPR extends to genes involved in diverse physiological processes having seemingly little to do with ER protein folding, and this includes a substantial number of mRNAs that are suppressed by stress rather than stimulated. Through multiple non-canonical mechanisms emanating from each of the UPR pathways, the cell dynamically regulates transcription and mRNA degradation. Here we highlight these mechanisms and their increasingly appreciated impact on physiological processes. PMID:24348511

  9. Role of brassinosteroids in alleviation of phenanthrene–cadmium co-contamination-induced photosynthetic inhibition and oxidative stress in tomato

    PubMed Central

    Ahammed, Golam Jalal; Yu, Jingquan

    2013-01-01

    Heavy metal pollution often occurs together with organic contaminants. Brassinosteroids (BRs) induce plant tolerance to several abiotic stresses, including phenanthrene (PHE) and cadmium (Cd) stress. However, the role of BRs in PHE+Cd co-contamination-induced stress amelioration is unknown. Here, the interactive effects of PHE, Cd, and 24-epibrassinolide (EBR; a biologically active BR) were investigated in tomato plants. The application of Cd (100 µM) alone was more phytotoxic than PHE applied alone (100 µM); however, their combined application resulted in slightly improved photosynthetic activity and pigment content compared with Cd alone after a 40 d exposure. Accumulation of reactive oxygen species and membrane lipid peroxidation were induced by PHE and/or Cd; however, the differences in effect were insignificant between Cd and PHE+Cd. The foliar application of EBR (0.1 µM) to PHE- and/or Cd-stressed plants alleviated photosynthetic inhibition and oxidative stress by causing enhancement of the activity of the enzymes and related transcript levels of the antioxidant system, secondary metabolism, and the xenobiotic detoxification system. Additionally, PHE and/or Cd residues were significantly decreased in both the leaves and roots after application of EBR, more specifically in PHE+Cd-stressed plants when treated with EBR, indicating a possible improvement in detoxification of these pollutants. The findings thus suggest a potential interaction of EBR and PHE for Cd stress alleviation. These results advocate a positive role for EBR in reducing pollutant residues for food safety and also strengthening phytoremediation. PMID:23201830

  10. Role of brassinosteroids in alleviation of phenanthrene-cadmium co-contamination-induced photosynthetic inhibition and oxidative stress in tomato.

    PubMed

    Ahammed, Golam Jalal; Choudhary, Sikander Pal; Chen, Shuangchen; Xia, Xiaojian; Shi, Kai; Zhou, Yanhong; Yu, Jingquan

    2013-01-01

    Heavy metal pollution often occurs together with organic contaminants. Brassinosteroids (BRs) induce plant tolerance to several abiotic stresses, including phenanthrene (PHE) and cadmium (Cd) stress. However, the role of BRs in PHE+Cd co-contamination-induced stress amelioration is unknown. Here, the interactive effects of PHE, Cd, and 24-epibrassinolide (EBR; a biologically active BR) were investigated in tomato plants. The application of Cd (100 µM) alone was more phytotoxic than PHE applied alone (100 µM); however, their combined application resulted in slightly improved photosynthetic activity and pigment content compared with Cd alone after a 40 d exposure. Accumulation of reactive oxygen species and membrane lipid peroxidation were induced by PHE and/or Cd; however, the differences in effect were insignificant between Cd and PHE+Cd. The foliar application of EBR (0.1 µM) to PHE- and/or Cd-stressed plants alleviated photosynthetic inhibition and oxidative stress by causing enhancement of the activity of the enzymes and related transcript levels of the antioxidant system, secondary metabolism, and the xenobiotic detoxification system. Additionally, PHE and/or Cd residues were significantly decreased in both the leaves and roots after application of EBR, more specifically in PHE+Cd-stressed plants when treated with EBR, indicating a possible improvement in detoxification of these pollutants. The findings thus suggest a potential interaction of EBR and PHE for Cd stress alleviation. These results advocate a positive role for EBR in reducing pollutant residues for food safety and also strengthening phytoremediation.

  11. JunB Inhibits ER Stress and Apoptosis in Pancreatic Beta Cells

    PubMed Central

    Gurzov, Esteban N.; Ortis, Fernanda; Bakiri, Latifa; Wagner, Erwin F.; Eizirik, Decio L.

    2008-01-01

    Cytokines contribute to pancreatic β-cell apoptosis in type 1 diabetes (T1D) by modulation of β-cell gene expression networks. The transcription factor Activator Protein-1 (AP-1) is a key regulator of inflammation and apoptosis. We presently evaluated the function of the AP-1 subunit JunB in cytokine-mediated β-cell dysfunction and death. The cytokines IL-1β+IFN-γ induced an early and transitory upregulation of JunB by NF-κB activation. Knockdown of JunB by RNA interference increased cytokine-mediated expression of inducible nitric oxide synthase (iNOS) and endoplasmic reticulum (ER) stress markers, leading to increased apoptosis in an insulin-producing cell line (INS-1E) and in purified rat primary β-cells. JunB knockdown β-cells and junB−/− fibroblasts were also more sensitive to the chemical ER stressor cyclopiazonic acid (CPA). Conversely, adenoviral-mediated overexpression of JunB diminished iNOS and ER markers expression and protected β-cells from cytokine-induced cell death. These findings demonstrate a novel and unexpected role for JunB as a regulator of defense mechanisms against cytokine- and ER stress-mediated apoptosis. PMID:18716665

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

    PubMed

    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. PMID:26566725

  13. ER stress responses in the absence of apoptosome: a comparative study in CASP9 proficient vs deficient mouse embryonic fibroblasts.

    PubMed

    Deegan, Shane; Saveljeva, Svetlana; Gupta, Sanjeev; MacDonald, David C; Samali, Afshin

    2014-08-29

    Cells respond to endoplasmic reticulum (ER) stress through the unfolded protein response (UPR), autophagy and cell death. In this study we utilized casp9(+/+) and casp9(-/-) MEFs to determine the effect of inhibition of mitochondrial apoptosis pathway on ER stress-induced-cell death, UPR and autophagy. We observed prolonged activation of UPR and autophagy in casp9(-/-) cells as compared with casp9(+/+) MEFs, which displayed transient activation of both pathways. Furthermore we showed that while casp9(-/-) MEFs were resistant to ER stress, prolonged exposure led to the activation of a non-canonical, caspase-mediated mode of cell death.

  14. ER stress responses in the absence of apoptosome: a comparative study in CASP9 proficient vs deficient mouse embryonic fibroblasts.

    PubMed

    Deegan, Shane; Saveljeva, Svetlana; Gupta, Sanjeev; MacDonald, David C; Samali, Afshin

    2014-08-29

    Cells respond to endoplasmic reticulum (ER) stress through the unfolded protein response (UPR), autophagy and cell death. In this study we utilized casp9(+/+) and casp9(-/-) MEFs to determine the effect of inhibition of mitochondrial apoptosis pathway on ER stress-induced-cell death, UPR and autophagy. We observed prolonged activation of UPR and autophagy in casp9(-/-) cells as compared with casp9(+/+) MEFs, which displayed transient activation of both pathways. Furthermore we showed that while casp9(-/-) MEFs were resistant to ER stress, prolonged exposure led to the activation of a non-canonical, caspase-mediated mode of cell death. PMID:25086361

  15. Parasite-induced ER stress response in hepatocytes facilitates Plasmodium liver stage infection.

    PubMed

    Inácio, Patricia; Zuzarte-Luís, Vanessa; Ruivo, Margarida T G; Falkard, Brie; Nagaraj, Nagarjuna; Rooijers, Koos; Mann, Matthias; Mair, Gunnar; Fidock, David A; Mota, Maria M

    2015-08-01

    Upon infection of a mammalian host, Plasmodium parasites first replicate inside hepatocytes, generating thousands of new parasites. Although Plasmodium intra-hepatic development represents a substantial metabolic challenge to the host hepatocyte, how infected cells respond to and integrate this stress remains poorly understood. Here, we present proteomic and transcriptomic analyses, revealing that the endoplasmic reticulum (ER)-resident unfolded protein response (UPR) is activated in host hepatocytes upon Plasmodium berghei infection. The expression of XBP1s--the active form of the UPR mediator XBP1--and the liver-specific UPR mediator CREBH is induced by P. berghei infection in vivo. Furthermore, this UPR induction increases parasite liver burden. Altogether, our data suggest that ER stress is a central feature of P. berghei intra-hepatic development, contributing to the success of infection. PMID:26113366

  16. Parasite-induced ER stress response in hepatocytes facilitates Plasmodium liver stage infection

    PubMed Central

    Inácio, Patricia; Zuzarte-Luís, Vanessa; Ruivo, Margarida TG; Falkard, Brie; Nagaraj, Nagarjuna; Rooijers, Koos; Mann, Matthias; Mair, Gunnar; Fidock, David A; Mota, Maria M

    2015-01-01

    Upon infection of a mammalian host, Plasmodium parasites first replicate inside hepatocytes, generating thousands of new parasites. Although Plasmodium intra-hepatic development represents a substantial metabolic challenge to the host hepatocyte, how infected cells respond to and integrate this stress remains poorly understood. Here, we present proteomic and transcriptomic analyses, revealing that the endoplasmic reticulum (ER)-resident unfolded protein response (UPR) is activated in host hepatocytes upon Plasmodium berghei infection. The expression of XBP1s—the active form of the UPR mediator XBP1—and the liver-specific UPR mediator CREBH is induced by P. berghei infection in vivo. Furthermore, this UPR induction increases parasite liver burden. Altogether, our data suggest that ER stress is a central feature of P. berghei intra-hepatic development, contributing to the success of infection. PMID:26113366

  17. Parasite-induced ER stress response in hepatocytes facilitates Plasmodium liver stage infection.

    PubMed

    Inácio, Patricia; Zuzarte-Luís, Vanessa; Ruivo, Margarida T G; Falkard, Brie; Nagaraj, Nagarjuna; Rooijers, Koos; Mann, Matthias; Mair, Gunnar; Fidock, David A; Mota, Maria M

    2015-08-01

    Upon infection of a mammalian host, Plasmodium parasites first replicate inside hepatocytes, generating thousands of new parasites. Although Plasmodium intra-hepatic development represents a substantial metabolic challenge to the host hepatocyte, how infected cells respond to and integrate this stress remains poorly understood. Here, we present proteomic and transcriptomic analyses, revealing that the endoplasmic reticulum (ER)-resident unfolded protein response (UPR) is activated in host hepatocytes upon Plasmodium berghei infection. The expression of XBP1s--the active form of the UPR mediator XBP1--and the liver-specific UPR mediator CREBH is induced by P. berghei infection in vivo. Furthermore, this UPR induction increases parasite liver burden. Altogether, our data suggest that ER stress is a central feature of P. berghei intra-hepatic development, contributing to the success of infection.

  18. AtHSPR may function in salt-induced cell death and ER stress in Arabidopsis.

    PubMed

    Yang, Tao; Zhang, Peng; Wang, Chongying

    2016-07-01

    Salt stress is a harmful and global abiotic stress to plants and has an adverse effect on all physiological processes of plants. Recently, we cloned and identified a novel AtHSPR (Arabidopsis thaliana Heat Shock Protein Related), which encodes a nuclear-localized protein with ATPase activity, participates in salt and drought tolerance in Arabidopsis. Transcript profiling analysis revealed a differential expression of genes involved in accumulation of reactive oxygen species (ROS), abscisic acid (ABA) signaling, stress response and photosynthesis between athspr mutant and WT under salt stress. Here, we provide further analysis of the data showing the regulation of salt-induced cell death and endoplasmic reticulum (ER) stress response in Arabidopsis and propose a hypothetical model for the role of AtHSPR in the regulation of the salt tolerance in Arabidopsis. PMID:27302034

  19. Rapamycin improves palmitate-induced ER stress/NF κ B pathways associated with stimulating autophagy in adipocytes.

    PubMed

    Yin, Jiajing; Gu, Liping; Wang, Yufan; Fan, Nengguang; Ma, Yuhang; Peng, Yongde

    2015-01-01

    Obesity-induced endoplasmic reticulum (ER) stress and inflammation lead to adipocytes dysfunction. Autophagy helps to adapt to cellular stress and involves in regulating innate inflammatory response. In present study, we examined the activity of rapamycin, a mTOR kinase inhibitor, against endoplasmic reticulum stress and inflammation in adipocytes. An in vitro model was used in which 3T3-L1 adipocytes were preloaded with palmitate (PA) to generate artificial hypertrophy mature adipocytes. Elevated autophagy flux and increased number of autophagosomes were observed in response to PA and rapamycin treatment. Rapamycin attenuated PA-induced PERK and IRE1-associated UPR pathways, evidenced by decreased protein levels of eIF2α phosphorylation, ATF4, CHOP, and JNK phosphorylation. Inhibiting autophagy with chloroquine (CQ) exacerbated these ER stress markers, indicating the role of autophagy in ameliorating ER stress. In addition, cotreatment of CQ abolished the anti-ER stress effects of rapamycin, which confirms the effect of rapamycin on ERs is autophagy-dependent. Furthermore, rapamycin decreased PA-induced nuclear translocation of NFκB P65 subunit, thereby NFκB-dependent inflammatory cytokines MCP-1 and IL-6 expression and secretion. In conclusion, rapamycin attenuated PA-induced ER stress/NFκB pathways to counterbalance adipocytes stress and inflammation. The beneficial of rapamycin in this context partly depends on autophagy. Stimulating autophagy may become a way to attenuate adipocytes dysfunction.

  20. ER stress transcription factor Xbp1 suppresses intestinal tumorigenesis and directs intestinal stem cells

    PubMed Central

    Niederreiter, Lukas; Fritz, Teresa M.J.; Adolph, Timon E.; Krismer, Anna-Maria; Offner, Felix A.; Tschurtschenthaler, Markus; Flak, Magdalena B.; Hosomi, Shuhei; Tomczak, Michal F.; Kaneider, Nicole C.; Sarcevic, Edina; Kempster, Sarah L.; Raine, Tim; Esser, Daniela; Rosenstiel, Philip; Kohno, Kenji; Iwawaki, Takao; Tilg, Herbert

    2013-01-01

    Unresolved endoplasmic reticulum (ER) stress in the epithelium can provoke intestinal inflammation. Hypomorphic variants of ER stress response mediators, such as X-box–binding protein 1 (XBP1), confer genetic risk for inflammatory bowel disease. We report here that hypomorphic Xbp1 function instructs a multilayered regenerative response in the intestinal epithelium. This is characterized by intestinal stem cell (ISC) expansion as shown by an inositol-requiring enzyme 1α (Ire1α)–mediated increase in Lgr5+ and Olfm4+ ISCs and a Stat3-dependent increase in the proliferative output of transit-amplifying cells. These consequences of hypomorphic Xbp1 function are associated with an increased propensity to develop colitis-associated and spontaneous adenomatous polyposis coli (APC)–related tumors of the intestinal epithelium, which in the latter case is shown to be dependent on Ire1α. This study reveals an unexpected role for Xbp1 in suppressing tumor formation through restraint of a pathway that involves an Ire1α- and Stat3-mediated regenerative response of the epithelium as a consequence of ER stress. As such, Xbp1 in the intestinal epithelium not only regulates local inflammation but at the same time also determines the propensity of the epithelium to develop tumors. PMID:24043762

  1. Alleviation of exogenous 6-benzyladenine on two genotypes of eggplant (Solanum melongena Mill.) growth under salt stress.

    PubMed

    Wu, Xuexia; He, Jie; Chen, Jianlin; Yang, Shaojun; Zha, Dingshi

    2014-01-01

    Cytokinins were recently shown to control plant adaptation to environmental stresses. To characterize the roles of cytokinins in the tolerance of eggplant (Solanum melongena Mill.) to salt stress, the protective effects of 6-benzyladenine (6-BA) on the growth, photosynthesis, and antioxidant capacity in the leaves of two eggplant cultivars Huqie12 (salt-sensitive) and Huqie4 (salt-tolerant) were investigated. Under 90 mM NaCl stress, Huqie4 showed higher biomass accumulation and less oxidative damage compared to the Huqie12. Application of exogenous 10 μM 6-BA significantly alleviated the growth suppression caused by salt stress in two eggplant genotypes. In parallel with the growth, 6-BA application in salt-stressed plants resulted in enhanced chlorophyll contents, as well as photosynthetic parameters such as net CO2 assimilation rate (P n), stomatal conductance (g s), transpiration rate (E), and intercellular CO2 concentration (C i). Furthermore, exogenous 6-BA also significantly reduced the O2 (-) production rate and malondialdehyde content and markedly increased the antioxidant enzymes superoxide dismutase and peroxidase, the antioxidant metabolites ascorbate and reduced glutathione (GSH), and proline in both genotypes under salt stress. The results indicate that exogenous 6-BA is useful to improve the salt resistance of eggplant, which is most likely related to the increase in photosynthesis and antioxidant capacity.

  2. Neuroprotective effects of propofol on ER stress-mediated apoptosis in neuroblastoma SH-SY5Y cells.

    PubMed

    Nakajima, Ai; Tsuji, Mayumi; Inagaki, Manami; Tamura, Yurie; Kato, Masumi; Niiya, Akifumi; Usui, Yuki; Oguchi, Katsuji

    2014-02-15

    Anesthetic treatment has been associated with widespread apoptotic neurodegeneration in the neonatal rodent brain. It has recently been suggested that propofol, a short-acting intravenous anesthetic agent, may have a potential as a neuroprotective agent. An apoptotic pathway mediated through endoplasmic reticulum (ER) stress has been attracting attention. ER stress is associated with accumulation of unfolded or misfolded proteins in ER, and ER stress-induced apoptosis is implicated in a wide range of diseases, including ischemia/reperfusion injury, neurodegeneration, and diabetes. We investigated whether thapsigargin-induced ER stress is prevented by propofol in human neuroblastoma SH-SY5Y cells. SH-SY5Y cells were pretreated with various concentrations of propofol (1-10 μM) for 3h before co-treatment with 0.5 μM thapsigargin and propofol for 20 h. Levels of ssDNA, specific evidence of apoptosis, and biomarkers of ER stress (mRNA expression of Chop and sXbp-1) were determined. We also assayed calpain and caspase-4 activities and intracellular Ca(2+) ([Ca(2+)]i) levels. Thapsigargin-induced increases in ssDNA levels, expressions of ER stress biomarkers, activities of caspase-4 and calpain, and level of [Ca(2+)]i were suppressed by co-incubation with propofol. Our data indicate the possibility that propofol inhibits the Ca(2+) release from ER at clinically employed dose levels. These results demonstrate that propofol suppresses the ER stress-induced apoptosis in this cell system, and may have the neuroprotective potency. It may also be a promising agent for preventing damage from cerebral ischemia or edema.

  3. Treadmill exercise alleviates stress-induced impairment of social interaction through 5-hydroxytryptamine 1A receptor activation in rats

    PubMed Central

    Kim, Tae-Woon; Lim, Baek-Vin; Kim, Kijeong; Seo, Jin-Hee; Kim, Chang-Ju

    2015-01-01

    Brain-derived neurotrophic factor (BDNF) and its receptors tyrosine kinase B (trkB), and cyclic adenosine monophosphate response element binding protein (CREB) have been suggested as the neurobiological risk factors causing depressive disorder. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. We in-vestigated the effect of treadmill exercise on social interaction in relation with BDNF and 5-HT expressions following stress in rats. Stress was induced by applying inescapable 0.2 mA electric foot shock to the rats for 7 days. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks. Social interaction test and western blot for BDNF, TrkB, pCREB, and 5-HT1A in the hippocampus were performed. The results indicate that the spend time with unfamiliar partner was decreased by stress, in contrast, treadmill exercise increased the spending time in the stress-induced rats. Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats. In addition, 5-HT1A receptor expression was de-creased by stress, in contrast, treadmill exercise enhanced 5-HT1A expression in the stress-induced rats. In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus. These effects of treadmill exercise are achieved through 5-HT1A receptor activation. PMID:26331133

  4. Treadmill exercise alleviates stress-induced impairment of social interaction through 5-hydroxytryptamine 1A receptor activation in rats.

    PubMed

    Kim, Tae-Woon; Lim, Baek-Vin; Kim, Kijeong; Seo, Jin-Hee; Kim, Chang-Ju

    2015-08-01

    Brain-derived neurotrophic factor (BDNF) and its receptors tyrosine kinase B (trkB), and cyclic adenosine monophosphate response element binding protein (CREB) have been suggested as the neurobiological risk factors causing depressive disorder. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. We in-vestigated the effect of treadmill exercise on social interaction in relation with BDNF and 5-HT expressions following stress in rats. Stress was induced by applying inescapable 0.2 mA electric foot shock to the rats for 7 days. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks. Social interaction test and western blot for BDNF, TrkB, pCREB, and 5-HT1A in the hippocampus were performed. The results indicate that the spend time with unfamiliar partner was decreased by stress, in contrast, treadmill exercise increased the spending time in the stress-induced rats. Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats. In addition, 5-HT1A receptor expression was de-creased by stress, in contrast, treadmill exercise enhanced 5-HT1A expression in the stress-induced rats. In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus. These effects of treadmill exercise are achieved through 5-HT1A receptor activation.

  5. Teacher Stress: What It Is, Why It's Important, How It Can Be Alleviated

    ERIC Educational Resources Information Center

    Prilleltensky, Isaac; Neff, Marilyn; Bessell, Ann

    2016-01-01

    Teacher stress can be conceptualized as an imbalance between risk and protective factors. Stress emanates from risk factors at the personal, interpersonal, and organizational levels. When risk factors exceed protective factors, teacher ability to cope with adversity is inhibited, likely resulting in stress and pernicious consequences. In this…

  6. How Do You Spell Relief? Alleviating Job Stress Caused by Organizations and Executives.

    ERIC Educational Resources Information Center

    Ginsburg, Sigmund G.

    1991-01-01

    College business officers should examine whether they and their institutions are practicing stress-inducing activities, and modify current practice to reduce stress on employees. Stresses can originate in the organizational framework, managerial style, or manager personality. Review of individual and organizational actions possible causing stress…

  7. Glycosylation-independent ERAD pathway serves as a backup system under ER stress.

    PubMed

    Ushioda, Ryo; Hoseki, Jun; Nagata, Kazuhiro

    2013-10-01

    During endoplasmic reticulum (ER)-associated degradation (ERAD), terminally misfolded proteins are retrotranslocated from the ER to the cytosol and degraded by the ubiquitin-proteasome system. Misfolded glycoproteins are recognized by calnexin and transferred to EDEM1, followed by the ER disulfide reductase ERdj5 and the BiP complex. The mechanisms involved in ERAD of nonglycoproteins, however, are poorly understood. Here we show that nonglycoprotein substrates are captured by BiP and then transferred to ERdj5 without going through the calnexin/EDEM1 pathway; after cleavage of disulfide bonds by ERdj5, the nonglycoproteins are transferred to the ERAD scaffold protein SEL1L by the aid of BiP for dislocation into the cytosol. When glucose trimming of the N-glycan groups of the substrates is inhibited, glycoproteins are also targeted to the nonglycoprotein ERAD pathway. These results indicate that two distinct pathways for ERAD of glycoproteins and nonglycoproteins exist in mammalian cells, and these pathways are interchangeable under ER stress conditions.

  8. ER stress and the decline and fall of pancreatic beta cells in type 1 diabetes

    PubMed Central

    Brozzi, Flora

    2016-01-01

    Components of the unfolded protein response (UPR) modulate beta cell inflammation and death in early type 1 diabetes (T1D). The UPR is a mechanism by which cells react to the accumulation of misfolded proteins in the endoplasmic reticulum (ER). It aims to restore cellular homeostasis, but in case of chronic or overwhelming ER stress the persistent activation of the UPR triggers apoptosis, contributing to the loss of beta cells in both T1D and type 2 diabetes. It remains to be determined how and why the transition from ‘physiological’ to ‘pathological’ UPR takes place. A key component of the UPR is the ER transmembrane protein IRE1α (inositol-requiring enzyme 1α). IRE1α activity is modulated by both intra-ER signals and by the formation of protein complexes at its cytosolic domain. The amplitude and duration of IRE1α signaling is critical for the transition between the adaptive and cell death programs, with particular relevance for the activation of the pro-apoptotic c-Jun N-terminal kinase (JNK) in beta cells. In the present review we discuss the available information on IRE1α-regulating proteins in beta cells and their downstream targets, and the important differences observed between cytokine-induced UPR in human and rodent beta cells. PMID:26899404

  9. Carbon monoxide alleviates ethanol-induced oxidative damage and inflammatory stress through activating p38 MAPK pathway

    SciTech Connect

    Li, Yanyan; Gao, Chao; Shi, Yanru; Tang, Yuhan; Liu, Liang; Xiong, Ting; Du, Min; Xing, Mingyou; Liu, Liegang; Yao, Ping

    2013-11-15

    Stress-inducible protein heme oxygenase-1(HO-1) is well-appreciative to counteract oxidative damage and inflammatory stress involving the pathogenesis of alcoholic liver diseases (ALD). The potential role and signaling pathways of HO-1 metabolite carbon monoxide (CO), however, still remained unclear. To explore the precise mechanisms, ethanol-dosed adult male Balb/c mice (5.0 g/kg.bw.) or ethanol-incubated primary rat hepatocytes (100 mmol/L) were pretreated by tricarbonyldichlororuthenium (II) dimmer (CORM-2, 8 mg/kg for mice or 20 μmol/L for hepatocytes), as well as other pharmacological reagents. Our data showed that CO released from HO-1 induction by quercetin prevented ethanol-derived oxidative injury, which was abolished by CO scavenger hemoglobin. The protection was mimicked by CORM-2 with the attenuation of GSH depletion, SOD inactivation, MDA overproduction, and the leakage of AST, ALT or LDH in serum and culture medium induced by ethanol. Moreover, CORM-2 injection or incubation stimulated p38 phosphorylation and suppressed abnormal Tnfa and IL-6, accompanying the alleviation of redox imbalance induced by ethanol and aggravated by inflammatory factors. The protective role of CORM-2 was abolished by SB203580 (p38 inhibitor) but not by PD98059 (ERK inhibitor) or SP600125 (JNK inhibitor). Thus, HO-1 released CO prevented ethanol-elicited hepatic oxidative damage and inflammatory stress through activating p38 MAPK pathway, suggesting a potential therapeutic role of gaseous signal molecule on ALD induced by naturally occurring phytochemicals. - Highlights: • CO alleviated ethanol-derived liver oxidative and inflammatory stress in mice. • CO eased ethanol and inflammatory factor-induced oxidative damage in hepatocytes. • The p38 MAPK is a key signaling mechanism for the protective function of CO in ALD.

  10. Nitric oxide and hydrogen peroxide alleviate drought stress in marigold explants and promote its adventitious root development.

    PubMed

    Liao, Wei-Biao; Huang, Gao-Bao; Yu, Ji-Hua; Zhang, Mei-Ling

    2012-09-01

    Drought stress is one of the most important environmental factors that regulates plant growth and development. In this study, we examined the effects of nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) on adventitious rooting in marigold (Tagetes erecta L.) under drought stress. The results showed that the promoting effect of NO or H(2)O(2) on rooting under drought stress was dose-dependent, with a maximal biological response at 10 μM NO donor sodium nitroprusside (SNP) or 600 μM H(2)O(2). Results also indicated that endogenous NO and H(2)O(2) may play crucial roles in rooting under drought conditions, and H(2)O(2) may be involved in rooting promoted by NO under drought stress. NO or H(2)O(2) treatment attenuated the destruction of mesophyll cells ultrastructure by drought stress. Similarly, NO or H(2)O(2) increased leaf chlorophyll content, chlorophyll fluorescence parameters (Fv/Fm, ΦPS II and qP), and hypocotyls soluble carbohydrate and protein content, while decreasing starch content. Results suggest that the protection of mesophyll cells ultrastructure by NO or H(2)O(2) under drought conditions improves the photosynthetic performance of leaves and alleviates the negative effects of drought on carbohydrate and nitrogen accumulation in explants, thereby adventitious rooting being promoted. PMID:22771430

  11. Spermine alleviates drought stress in white clover with different resistance by influencing carbohydrate metabolism and dehydrins synthesis.

    PubMed

    Li, Zhou; Jing, Wen; Peng, Yan; Zhang, Xin Quan; Ma, Xiao; Huang, Lin Kai; Yan, Yan-Hong

    2015-01-01

    The objective of this research was to analyse whether ameliorating drought stress through exogenously applied spermine (Spm) was related to carbohydrate metabolism, dehydrins accumulation and the transcription of genes encoding dehydrins in two white clovers (drought-susceptible cv. 'Ladino' and drought-resistant cv. 'Haifa') under controlled drying conditions for 10 days. The results show that the application of Spm effectively alleviates negative effects caused by drought stress in both cultivars. Exogenous Spm led to accumulation of more water-soluble carbohydrates (WSC), sucrose, fructose and sorbitol in both cultivars under drought stress, and also significantly elevated glucose content in leaves of drought-resistant cv. 'Haifa', but had no effect on drought-susceptible cv. 'Ladino'. Accordingly, the key enzyme activities of sucrose and sorbitol metabolism changed along with the application of Spm under drought stress. Spm induced a significant increase in sucrose phosphate synthase (SPS) or sorbitol dehydrogenase (SDH) activity, but decrease in sucrose synthetase (SS) activity when two cultivars were subjected to drought. In addition, the improved accumulation of dehydrins induced by exogenous Spm coincided with three genes expression which was responsible for dehydrins synthesis. But Spm-induced transcript level of dehydrin genes increased earlier in cv. 'Ladino' than that in cv. 'Haifa'. Thus, these results suggest that ameliorating drought stress through exogenously applied Spm may be associated with increased carbohydrate accumulation and dehydrins synthesis. There are differences between drought-susceptible and -resistant white clover cultivars related to Spm regulation of WSC metabolism and dehydrins expression.

  12. Dengue-induced autophagy, virus replication and protection from cell death require ER stress (PERK) pathway activation

    PubMed Central

    Datan, E; Roy, S G; Germain, G; Zali, N; McLean, J E; Golshan, G; Harbajan, S; Lockshin, R A; Zakeri, Z

    2016-01-01

    A virus that reproduces in a host without killing cells can easily establish a successful infection. Previously, we showed that dengue-2, a virus that threatens 40% of the world, induces autophagy, enabling dengue to reproduce in cells without triggering cell death. Autophagy further protects the virus-laden cells from further insults. In this study, we evaluate how it does so; we show that dengue upregulates host pathways that increase autophagy, namely endoplasmic reticulum (ER) stress and ataxia telangiectasia mutated (ATM) signaling followed by production of reactive oxygen species (ROS). Inhibition of ER stress or ATM signaling abrogates the dengue-conferred protection against other cell stressors. Direct inhibition of ER stress response in infected cells decreases autophagosome turnover, reduces ROS production and limits reproduction of dengue virus. Blocking ATM activation, which is an early response to infection, decreases transcription of ER stress response proteins, but ATM has limited impact on production of ROS and virus titers. Production of ROS determines only late-onset autophagy in infected cells and is not necessary for dengue-induced protection from stressors. Collectively, these results demonstrate that among the multiple autophagy-inducing pathways during infection, ER stress signaling is more important to viral replication and protection of cells than either ATM or ROS-mediated signaling. To limit virus production and survival of dengue-infected cells, one must address the earliest phase of autophagy, induced by ER stress. PMID:26938301

  13. ER stress and autophagy are involved in the apoptosis induced by cisplatin in human lung cancer cells

    PubMed Central

    SHI, SHAOMIN; TAN, PING; YAN, BINGDI; GAO, RONG; ZHAO, JIANJUN; WANG, JING; GUO, JIA; LI, NING; MA, ZHONGSEN

    2016-01-01

    Cisplatin [cis-diamminedichloroplatinum II (CDDP)] is one of the most classical and effective chemotherapeutic drugs for the treatment of cancers including lung cancer. However, the presence of cisplatin resistance in cancer lowers its curative effect and limits its usage in the clinic. The aim of the present study was to investigate the underlying mechanisms of cisplatin resistance in lung cancer involving endoplasmic reticulum (ER) stress and autophagy. In the present study, we detected the effect of cisplatin on cell viability, ER stress and autophagy in lung cancer cell lines A549 and H460. We also tested the effects of ER stress and autophagy on apoptosis induced by cisplatin. The results showed that cisplatin induced apoptosis, ER stress and autophagy in lung cancer cell lines. In addition, the inhibition of ER stress by 4-phenylbutyric acid (4-PBA) or tauroursodeoxycholic acid sodium (TUDC) enhanced cisplatin-induced apoptosis in the human lung cancer cells. Meanwhile, combination treatment with the autophagic inhibitor 3-methyladenine (3-MA) or chloroquine (CQ) further increased the apoptosis induced by cisplatin in the human lung cancer cells. The present study provides a novel treatment strategy - cisplatin in combination with an autophagic inhibitor or an ER stress inhibitor leads to increased apoptosis in human lung cancer cells. PMID:26985651

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

    PubMed Central

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

    2016-01-01

    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

  15. FAM3A attenuates ER stress-induced mitochondrial dysfunction and apoptosis via CHOP-Wnt pathway.

    PubMed

    Song, Qing; Gou, Wen-Li; Zhang, Rong

    2016-03-01

    Endoplasmic reticulum (ER) stress is linked to several neurological disorders, and neuronal injury cascades initiated by excessive ER stress are mediated, in part, via mitochondrial dysfunction. In the present study, we identified FAM3A as an important regulator of ER stress-induced cell death in neuronal HT22 cells. The ER stress inductor tunicamycin (TM) significantly decreased the expression of FAM3A at both mRNA and protein levels, which was shown to be dependent on the induction of reactive oxygen species (ROS). Overexpression of FAM3A attenuated TM-induced apoptosis and activation of ER stress factors, but had no effect on ER calcium metabolism in HT22 cells. We also found decreased mitochondrial ROS generation, inhibited cytochrome c release and preserved mitochondrial membrane potential (MMP) in FAM3A overexpressed cells. In addition, the experiments using isolated mitochondria showed that overexpression of FAM3A attenuated mitochondrial swelling and loss of mitochondrial Ca(2+) buffering capacity after TM exposure. By using specific targeted small interfering RNA (siRNA) to knockdown the expression of the C/EBP homologous protein (CHOP), we found that FAM3A-induced protection and inhibition of ER stress was mediated by inverting TM-induced decrease of Wnt through the CHOP pathway. Our study demonstrates a pivotal role of FAM3A in protecting against TM-induced cytotoxicity via regulating CHOP-Wnt pathway, and suggests the therapeutic values of FAM3A overexpression against ER stress-associated neuronal injury. PMID:26939760

  16. Nitric Oxide Alleviates Salt Stress Inhibited Photosynthetic Performance by Interacting with Sulfur Assimilation in Mustard.

    PubMed

    Fatma, Mehar; Masood, Asim; Per, Tasir S; Khan, Nafees A

    2016-01-01

    The role of nitric oxide (NO) and sulfur (S) on stomatal responses and photosynthetic performance was studied in mustard (Brassica juncea L.) in presence or absence of salt stress. The combined application of 100 μM NO (as sodium nitroprusside) and 200 mg S kg(-1) soil (S) more prominently influenced stomatal behavior, photosynthetic and growth performance both in the absence and presence of salt stress. The chloroplasts from salt-stressed plants had disorganized chloroplast thylakoids, but combined application of NO and S resulted in well-developed chloroplast thylakoids and properly stacked grana. The leaves from plants receiving NO plus S exhibited lower superoxide ion accumulation under salt stress than the plants receiving NO or S. These plants also exhibited increased activity of ATP-sulfurylase (ATPS), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) and optimized NO generation that helped in minimizing oxidative stress. The enhanced S-assimilation of these plants receiving NO plus S resulted in increased production of cysteine (Cys) and reduced glutathione (GSH). These findings indicated that NO influenced photosynthesis under salt stress by regulating oxidative stress and its effects on S-assimilation, an antioxidant system and NO generation. The results suggest that NO improves photosynthetic performance of plants grown under salt stress more effectively when plants received S. PMID:27200007

  17. Nitric Oxide Alleviates Salt Stress Inhibited Photosynthetic Performance by Interacting with Sulfur Assimilation in Mustard

    PubMed Central

    Fatma, Mehar; Masood, Asim; Per, Tasir S.; Khan, Nafees A.

    2016-01-01

    The role of nitric oxide (NO) and sulfur (S) on stomatal responses and photosynthetic performance was studied in mustard (Brassica juncea L.) in presence or absence of salt stress. The combined application of 100 μM NO (as sodium nitroprusside) and 200 mg S kg−1 soil (S) more prominently influenced stomatal behavior, photosynthetic and growth performance both in the absence and presence of salt stress. The chloroplasts from salt-stressed plants had disorganized chloroplast thylakoids, but combined application of NO and S resulted in well-developed chloroplast thylakoids and properly stacked grana. The leaves from plants receiving NO plus S exhibited lower superoxide ion accumulation under salt stress than the plants receiving NO or S. These plants also exhibited increased activity of ATP-sulfurylase (ATPS), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) and optimized NO generation that helped in minimizing oxidative stress. The enhanced S-assimilation of these plants receiving NO plus S resulted in increased production of cysteine (Cys) and reduced glutathione (GSH). These findings indicated that NO influenced photosynthesis under salt stress by regulating oxidative stress and its effects on S-assimilation, an antioxidant system and NO generation. The results suggest that NO improves photosynthetic performance of plants grown under salt stress more effectively when plants received S. PMID:27200007

  18. Silicon (Si) alleviates cotton (Gossypium hirsutum L.) from zinc (Zn) toxicity stress by limiting Zn uptake and oxidative damage.

    PubMed

    Anwaar, Shad Ali; Ali, Shafaqat; Ali, Skhawat; Ishaque, Wajid; Farid, Mujahid; Farooq, Muhammad Ahsan; Najeeb, Ullah; Abbas, Farhat; Sharif, Muhammad

    2015-03-01

    Silicon (Si) is as an important fertilizer element, which has been found effective in enhancing plant tolerance to variety of biotic and a-biotic stresses. This study investigates the Si potential to alleviate zinc (Zn) toxicity stress in cotton (Gossypium hirsutum L.). Cotton plants were grown in hydroponics and exposed to different Zn concentration, 0, 25, and 50 μM, alone and/or in combination with 1 mM Si. Incremental Zn concentration in growth media instigated the cellular oxidative damage that was evident from elevated levels of hydrogen peroxide (H2O2), electrolyte leakage, and malondialdehyde (MDA) and consequently inhibited cotton growth, biomass, chlorophyll pigments, and photosynthetic process. Application of Si significantly suppressed Zn accumulation in various plant parts, i.e., roots, stems, and leaves and thus promoted biomass, photosynthetic, growth parameters, and antioxidant enzymes activity of Zn-stressed as well unstressed plants. In addition, Si reduced the MDA and H2O2 production and electrolyte leakage suggesting its role in protecting cotton plants from Zn toxicity-induced oxidative damage. Thus, the study indicated that exogenous Si application could improve growth and development of cotton crop experiencing Zn toxicity stress by limiting Zn bioavailability and oxidative damage.

  19. Current developments in arbuscular mycorrhizal fungi research and its role in salinity stress alleviation: a biotechnological perspective.

    PubMed

    Kumar, Ashwani; Dames, Joanna F; Gupta, Aditi; Sharma, Satyawati; Gilbert, Jack A; Ahmad, Parvaiz

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) form widespread symbiotic associations with 80% of known land plants. They play a major role in plant nutrition, growth, water absorption, nutrient cycling and protection from pathogens, and as a result, contribute to ecosystem processes. Salinity stress conditions undoubtedly limit plant productivity and, therefore, the role of AMF as a biological tool for improving plant salt stress tolerance, is gaining economic importance worldwide. However, this approach requires a better understanding of how plants and AMF intimately interact with each other in saline environments and how this interaction leads to physiological changes in plants. This knowledge is important to develop sustainable strategies for successful utilization of AMF to improve plant health under a variety of stress conditions. Recent advances in the field of molecular biology, "omics" technology and advanced microscopy can provide new insight about these mechanisms of interaction between AMF and plants, as well as other microbes. This review mainly discusses the effect of salinity on AMF and plants, and role of AMF in alleviation of salinity stress including insight on methods for AMF identification. The focus remains on latest advancements in mycorrhizal research that can potentially offer an integrative understanding of the role of AMF in salinity tolerance and sustainable crop production. PMID:24708070

  20. Evaluation of arbuscular mycorrhizal fungi capacity to alleviate abiotic stress of olive (Olea europaea L.) plants at different transplant conditions.

    PubMed

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth.

  1. Evaluation of Arbuscular Mycorrhizal Fungi Capacity to Alleviate Abiotic Stress of Olive (Olea europaea L.) Plants at Different Transplant Conditions

    PubMed Central

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth. PMID:24688382

  2. Evaluation of arbuscular mycorrhizal fungi capacity to alleviate abiotic stress of olive (Olea europaea L.) plants at different transplant conditions.

    PubMed

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth. PMID:24688382

  3. Activation of NRF2/ARE by isosilybin alleviates Aβ25-35-induced oxidative stress injury in HT-22 cells.

    PubMed

    Zhou, Jing; Chao, Gao; Li, YuLei; Wu, Min; Zhong, ShuZhi; Feng, ZunYong

    2016-10-01

    Aβ-mediated oxidative stress damage is considered a direct cause of Alzheimer's disease (AD). Therefore, drugs that have been developed to block oxidative stress are considered effective for AD treatment. Isosilybin is a flavonoid compound extracted from Silybum marianum, and it has been confirmed to have many pharmacological activities. This study aimed to verify that isosilybin could alleviate the Aβ25-35-induced oxidative stress damage in HT-22 hippocampal cells and to investigate the specific targets of isosilybin. A non-toxic dose of isosilybin significantly inhibited the production of reactive oxygen species (ROS), the release of malondialdehyde (MDA) and lactate dehydrogenase (LDH), and the Aβ25-35-stimulated reduction in total antioxidant capacity (T-AOC). Subsequent studies showed that isosilybin significantly increased the protein and mRNA expression of antioxidases, including heme oxygenase-1 (HO-1), glutathione S-transferase (GST), and aldo-keto reductases 1C1 and 1C2 (AKR1C2). Moreover, isosilybin stimulated the activity of an antioxidant-response element (ARE)-driven luciferase reporter gene. Further studies showed that isosilybin induced the expression of NFR-2 in a time- and dose-dependent manner and promoted its translocation to the nucleus. This result indicated that the antioxidant function of isosilybin might be achieved through the activation of NRF2/ARE signalling. Subsequent studies showed that the NRF2-specific agonist t-BHQ effectively inhibited ROS, MDA and LDH release and T-AOC reduction under Aβ25-35 stimulation. In addition, t-BHQ induced the expression of HO-1, GST, and AKR1C2, as well as the activity of ARE luciferase reporter plasmids. NRF2 siRNA blocked the antioxidative stress damage function of isosilybin. Therefore, NRF2 is likely to be a key mediator of isosilybin's anti-Aβ25-35-mediated oxidative stress damage function. Overall, our results confirmed that isosilybin regulates the expression of HO-1, GST, and AKR1C2 through

  4. Nutritional Interventions to Alleviate the Negative Consequences of Heat Stress12

    PubMed Central

    Rhoads, Robert P.; Baumgard, Lance H.; Suagee, Jessica K.; Sanders, Sara R.

    2013-01-01

    Energy metabolism is a highly coordinated process, and preferred fuel(s) differ among tissues. The hierarchy of substrate use can be affected by physiological status and environmental factors including high ambient temperature. Unabated heat eventually overwhelms homeothermic mechanisms resulting in heat stress, which compromises animal health, farm animal production, and human performance. Various aspects of heat stress physiology have been extensively studied, yet a clear understanding of the metabolic changes occurring at the cellular, tissue, and whole-body levels in response to an environmental heat load remains ill-defined. For reasons not yet clarified, circulating nonesterified fatty acid levels are reduced during heat stress, even in the presence of elevated stress hormones (epinephrine, glucagon, and cortisol), and heat-stressed animals often have a blunted lipolytic response to catabolic signals. Either directly because of or in coordination with this, animals experiencing environmental hyperthermia exhibit a shift toward carbohydrate use. These metabolic alterations occur coincident with increased circulating basal and stimulated plasma insulin concentrations. Limited data indicate that proper insulin action is necessary to effectively mount a response to heat stress and minimize heat-induced damage. Consistent with this idea, nutritional interventions targeting increased insulin action may improve tolerance and productivity during heat stress. Further research is warranted to uncover the effects of heat on parameters associated with energy metabolism so that more appropriate and effective treatment methodologies can be designed. PMID:23674792

  5. The wheat MAP kinase phosphatase 1 alleviates salt stress and increases antioxidant activities in Arabidopsis.

    PubMed

    Zaidi, Ikram; Ebel, Chantal; Belgaroui, Nibras; Ghorbel, Mouna; Amara, Imène; Hanin, Moez

    2016-04-01

    Mitogen-activated protein kinase phosphatases (MKPs) are important negative regulators in the MAPK signaling pathways, which play crucial roles in plant growth, development and stress responses. We have previously shown that the heterologous expression of a durum wheat MKP, TMKP1, results in increased tolerance to salt stress in yeast but its particular contribution in salt stress tolerance in plants was not investigated. Here, TMKP1 was overexpressed in Arabidopsis thaliana and physiological changes were assessed in transgenic plants exposed to stress conditions. Under salt stress and especially LiCl, the TMKP1 overexpressors displayed higher germination rates in comparison to wild type plants. The enhancement of salt stress tolerance was accompanied by increased antioxidant enzyme activities, namely superoxide dismutase, catalase and peroxydases. Such increases in antioxidant activities were concomitant with lower malondialdehyde, superoxide anion O2(-) and hydrogen peroxide levels in the TMKP1 transgenic seedlings. Moreover, we provide evidence that, in contrast to the Arabidopsis ortholog AtMKP1, TMKP1 acts as a positive regulator of salt stress tolerance via its ectopic expression in the Arabidopsis mkp1 mutant. PMID:26927025

  6. Haem oxygenase-1 is involved in salicylic acid-induced alleviation of oxidative stress due to cadmium stress in Medicago sativa

    PubMed Central

    Shen, Wenbiao

    2012-01-01

    This work examines the involvement of haem oxygenase-1 (HO-1) in salicylic acid (SA)-induced alleviation of oxidative stress as a result of cadmium (Cd) stress in alfalfa (Medicago sativa L.) seedling roots. CdCl2 exposure caused severe growth inhibition and Cd accumulation, which were potentiated by pre-treatment with zinc protoporphyrin (ZnPPIX), a potent HO-1 inhibitor. Pre-treatment of plants with the HO-1 inducer haemin or SA, both of which could induce MsHO1 gene expression, significantly reduced the inhibition of growth and Cd accumulation. The alleviation effects were also evidenced by a decreased content of thiobarbituric acid-reactive substances (TBARS). The antioxidant behaviour was confirmed by histochemical staining for the detection of lipid peroxidation and the loss of plasma membrane integrity. Furthermore, haemin and SA pre-treatment modulated the activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), and guaiacol peroxidase (POD), or their corresponding transcripts. Significant enhancement of the ratios of reduced/oxidized homoglutathione (hGSH), ascorbic acid (ASA)/dehydroascorbate (DHA), and NAD(P)H/NAD(P)+, and expression of their metabolism genes was observed, consistent with a decreased reactive oxygen species (ROS) distribution in the root tips. These effects are specific for HO-1, since ZnPPIX blocked the above actions, and the aggravated effects triggered by SA plus ZnPPIX were differentially reversed when carbon monoxide (CO) or bilirubin (BR), two catalytic by-products of HO-1, was added. Together, the results suggest that HO-1 is involved in the SA-induced alleviation of Cd-triggered oxidative stress by re-establishing redox homeostasis. PMID:22915740

  7. Overexpression of Arabidopsis AnnAt8 Alleviates Abiotic Stress in Transgenic Arabidopsis and Tobacco

    PubMed Central

    Yadav, Deepanker; Ahmed, Israr; Shukla, Pawan; Boyidi, Prasanna; Kirti, Pulugurtha Bharadwaja

    2016-01-01

    Abiotic stress results in massive loss of crop productivity throughout the world. Because of our limited knowledge of the plant defense mechanisms, it is very difficult to exploit the plant genetic resources for manipulation of traits that could benefit multiple stress tolerance in plants. To achieve this, we need a deeper understanding of the plant gene regulatory mechanisms involved in stress responses. Understanding the roles of different members of plant gene families involved in different stress responses, would be a step in this direction. Arabidopsis, which served as a model system for the plant research, is also the most suitable system for the functional characterization of plant gene families. Annexin family in Arabidopsis also is one gene family which has not been fully explored. Eight annexin genes have been reported in the genome of Arabidopsis thaliana. Expression studies of different Arabidopsis annexins revealed their differential regulation under various abiotic stress conditions. AnnAt8 (At5g12380), a member of this family has been shown to exhibit ~433 and ~175 fold increase in transcript levels under NaCl and dehydration stress respectively. To characterize Annexin8 (AnnAt8) further, we have generated transgenic Arabidopsis and tobacco plants constitutively expressing AnnAt8, which were evaluated under different abiotic stress conditions. AnnAt8 overexpressing transgenic plants exhibited higher seed germination rates, better plant growth, and higher chlorophyll retention when compared to wild type plants under abiotic stress treatments. Under stress conditions transgenic plants showed comparatively higher levels of proline and lower levels of malondialdehyde compared to the wild-type plants. Real-Time PCR analyses revealed that the expression of several stress-regulated genes was altered in AnnAt8 over-expressing transgenic tobacco plants, and the enhanced tolerance exhibited by the transgenic plants can be correlated with altered expressions of

  8. Lens ER-stress response during cataract development in Mip-mutant mice.

    PubMed

    Zhou, Yuefang; Bennett, Thomas M; Shiels, Alan

    2016-08-01

    Major intrinsic protein (MIP) is a functional water-channel (AQP0) that also plays a key role in establishing lens fiber cell architecture. Genetic variants of MIP have been associated with inherited and age-related forms of cataract; however, the underlying pathogenic mechanisms are unclear. Here we have used lens transcriptome profiling by microarray-hybridization and qPCR to identify pathogenic changes during cataract development in Mip-mutant (Lop/+) mice. In postnatal Lop/+ lenses (P7) 99 genes were up-regulated and 75 were down-regulated (>2-fold, p=<0.05) when compared with wild-type. A pathway analysis of up-regulated genes in the Lop/+ lens (P7) was consistent with endoplasmic reticulum (ER)-stress and activation of the unfolded protein response (UPR). The most up-regulated UPR genes (>4-fold) in the Lop/+ lens included Chac1>Ddit3>Atf3>Trib3>Xbp1 and the most down-regulated genes (>5-fold) included two anti-oxidant genes, Hspb1 and Hmox1. Lop/+ lenses were further characterized by abundant TUNEL-positive nuclei within central degenerating fiber cells, glutathione depletion, free-radical overproduction, and calpain hyper-activation. These data suggest that Lop/+ lenses undergo proteotoxic ER-stress induced cell-death resulting from prolonged activation of the Eif2ak3/Perk-Atf4-Ddit3-Chac1 branch of the UPR coupled with severe oxidative-stress.

  9. Involvement of ER stress and activation of apoptotic pathways in fisetin induced cytotoxicity in human melanoma.

    PubMed

    Syed, Deeba N; Lall, Rahul K; Chamcheu, Jean Christopher; Haidar, Omar; Mukhtar, Hasan

    2014-12-01

    The prognosis of malignant melanoma remains poor in spite of recent advances in therapeutic strategies for the deadly disease. Fisetin, a dietary flavonoid is currently being investigated for its growth inhibitory properties in various cancer models. We previously showed that fisetin inhibited melanoma growth in vitro and in vivo. Here, we evaluated the molecular basis of fisetin induced cytotoxicity in metastatic human melanoma cells. Fisetin treatment induced endoplasmic reticulum (ER) stress in highly aggressive A375 and 451Lu human melanoma cells, as revealed by up-regulation of ER stress markers including IRE1α, XBP1s, ATF4 and GRP78. Time course analysis indicated that the ER stress was associated with activation of the extrinsic and intrinsic apoptotic pathways. Fisetin treated 2-D melanoma cultures displayed autophagic response concomitant with induction of apoptosis. Prolonged treatment (16days) with fisetin in a 3-D reconstituted melanoma model resulted in inhibition of melanoma progression with significant apoptosis, as evidenced by increased staining of cleaved Caspase-3 in the treated constructs. However, no difference in the expression of autophagic marker LC-3 was noted between treated and control groups. Fisetin treatment to 2-D melanoma cultures resulted in phosphorylation and activation of the multifunctional AMP-activated protein kinase (AMPK) involved in the regulation of diverse cellular processes, including autophagy and apoptosis. Silencing of AMPK failed to prevent cell death indicating that fisetin induced cytotoxicity is mediated through both AMPK-dependent and -independent mechanisms. Taken together, our studies confirm apoptosis as the primary mechanism through which fisetin inhibits melanoma cell growth and that activation of both extrinsic and intrinsic pathways contributes to fisetin induced cytotoxicity.

  10. Chewing gum alleviates negative mood and reduces cortisol during acute laboratory psychological stress.

    PubMed

    Scholey, Andrew; Haskell, Crystal; Robertson, Bernadette; Kennedy, David; Milne, Anthea; Wetherell, Mark

    2009-06-22

    The notion that chewing gum may relieve stress was investigated in a controlled setting. A multi-tasking framework which reliably evokes stress and also includes performance measures was used to induce acute stress in the laboratory. Using a randomised crossover design forty participants (mean age 21.98 years) performed on the multi-tasking framework at two intensities (on separate days) both while chewing and not chewing. Order of workload intensity and chewing conditions were counterbalanced. Before and after undergoing the platform participants completed the state portion of the State-Trait Anxiety Inventory, Bond-Lader visual analogue mood scales, a single Stress Visual Analogue Scale and provided saliva samples for cortisol measurement. Baseline measures showed that both levels of the multi-tasking framework were effective in significantly reducing self-rated alertness, calmness and contentment while increasing self-rated stress and state anxiety. Cortisol levels fell during both levels of the stressor during the morning, reflecting the predominance of a.m. diurnal changes, but this effect was reversed in the afternoon which may reflect a measurable stress response. Pre-post stressor changes (Delta) for each measure at baseline were subtracted from Delta scores under chewing and no chewing conditions. During both levels of stress the chewing gum condition was associated with significantly better alertness and reduced state anxiety, stress and salivary cortisol. Overall performance on the framework was also significantly better in the chewing condition. The mechanisms underlying these effects are unknown but may involve improved cerebral blood flow and/or effects secondary to performance improvement during gum chewing. PMID:19268676

  11. Weak microwave can alleviate water deficit induced by osmotic stress in wheat seedlings.

    PubMed

    Chen, Yi-Ping; Jia, Jing-Fen; Han, Xiao-Ling

    2009-01-01

    The aim of the investigation is to determine the effect of microwave pretreatment of wheat seeds on the resistance of seedlings to osmotic stress. Changes in biophysical, physiological and biochemical characters were measured. The results showed: (1) The magnetic field intensity and seeds temperature increased progressively with microwave pretreatments of 5, 10, 15, 20 s and 25 s compared with controls. Although each microwave pretreatment resulted in an increase in alpha-amylase activity and photon emission intensity, the increase of alpha-amylase activity and photon emission intensity was maximal at a microwave pretreatment of 10 s. (2) Osmotic stress induced by PEG treatment enhanced the concentration of malondialdehyde, while decreasing the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid, glutathione in the seedlings compared with controls. However, compared to osmotic stress alone, in the seedlings treated with microwave irradiation plus osmotic stress the concentration of malondialdehyde decreased, while the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid and glutathione increased. These results suggest that a suitable dose of microwave radiation can enhance the capability to eliminate free radicals induced by osmotic stress in wheat seedlings resulting in an increase in resistance to osmotic stress.

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

    PubMed Central

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

    2016-01-01

    Background/Objectives: 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). Subjects/Methods: 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-ERT2-Rosa-STOPloxP/loxP-Guca2b mice in which tamoxifen induces transgenic hormone expression in brain. Results: 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. Conclusions: These studies reveal a novel pathophysiological mechanism contributing to obesity in which calorie-induced suppression

  13. Biochar alleviates combined stress of ammonium and acids by firstly enriching Methanosaeta and then Methanosarcina.

    PubMed

    Lü, Fan; Luo, Chenghao; Shao, Liming; He, Pinjing

    2016-03-01

    This investigation evaluated the effectiveness of biochar of different particle sizes in alleviating ammonium (NH4(+)) inhibition (up to 7 g-N/L) during anaerobic digestion of 6 g/L glucose. Compared to the control treatment without biochar addition, treatments that included biochar particles 2-5 mm, 0.5-1 mm and 75-150 μm in size reduced the methanization lag phase by 23.9%, 23.8% and 5.9%, respectively, and increased the maximum methane production rate by 47.1%, 23.5% and 44.1%, respectively. These results confirmed that biochar accelerated the initiation of methanization during anaerobic digestion under double inhibition risk from both ammonium and acids. Furthermore, fine biochar significantly promoted the production of volatile fatty acids (VFAs). Comparative analysis on the archaeal and bacterial diversity at the early and later stages of digestion, and in the suspended, biochar loosely bound, and biochar tightly bound fractions suggested that, in suspended fractions, hydrogenotrophic Methanobacterium was actively resistant to ammonium. However, acetoclastic Methanosaeta can survive at VFAs concentrations up to 60-80 mmol-C/L by improved affinity to conductive biochar, resulting in the accelerated initiation of acetate degradation. Improved methanogenesis was followed by the colonization of the biochar tightly bound fractions by Methanosarcina. The selection of appropriate biochar particles sizes was important in facilitating the initial colonization of microbial cells.

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

    PubMed

    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. PMID:27665771

  15. Bilobalide alleviates depression-like behavior and cognitive deficit induced by chronic unpredictable mild stress in mice.

    PubMed

    Wu, Ruiyong; Shui, Li; Wang, Siyang; Song, Zhenzhen; Tai, Fadao

    2016-10-01

    Bilobalide (BB), a unique constituent of Ginkgo biloba, has powerful neuroprotection and stress-alleviating properties. However, whether BB exerts a positive effect on depression and cognitive deficit induced by chronic stress is not known. The present study was designed to investigate the influence of BB on depression and cognitive impairments induced by chronic unpredictable mild stress (CUMS) in mice. During daily exposure to stressors for 5 consecutive weeks, mice were administered BB at the doses of 0, 3, or 6 mg/kg/day intraperitoneally. We replicated the finding that CUMS induced depression-like behavior and cognitive deficits as the CUMS+vehicle (VEH) group showed a significant increase in immobility in the tail suspension test, a decrease in the discrimination index of the novel object recognition task, and increased latency to platform and decreased number of platform crossings in the Morris water maze compared with the control+VEH group. Chronic administration of BB effectively reversed these alterations. In addition, the CUMS+VEH group showed significantly higher levels of baseline serum corticosterone than those of the control+VEH group and BB dose-dependently inhibited this effect. Our results suggest that BB may be useful for inhibition of depression-like behavior and cognitive deficits, and this protective effect was possibly exerted partly through an action on the hypothalamic-pituitary-adrenal axis. PMID:27509313

  16. Brassinolide Increases Potato Root Growth In Vitro in a Dose-Dependent Way and Alleviates Salinity Stress

    PubMed Central

    Xia, Shitou; Su, Yi; Wang, Huiqun; Luo, Weigui; Su, Shengying

    2016-01-01

    Brassinosteroids (BRs) are steroidal phytohormones that regulate various physiological processes, such as root development and stress tolerance. In the present study, we showed that brassinolide (BL) affects potato root in vitro growth in a dose-dependent manner. Low BL concentrations (0.1 and 0.01 μg/L) promoted root elongation and lateral root development, whereas high BL concentrations (1–100 μg/L) inhibited root elongation. There was a significant (P < 0.05) positive correlation between root activity and BL concentrations within a range from 0.01 to 100 μg/L, with the peak activity of 8.238 mg TTC·g−1 FW·h−1 at a BL concentration of 100 μg/L. Furthermore, plants treated with 50 μg/L BL showed enhanced salt stress tolerance through in vitro growth. Under this scenario, BL treatment enhanced the proline content and antioxidant enzymes' (superoxide dismutase, peroxidase, and catalase) activity and reduced malondialdehyde content in potato shoots. Application of BL maintain K+ and Na+ homeostasis by improving tissue K+/Na+ ratio. Therefore, we suggested that the effects of BL on root development from stem fragments explants as well as on primary root development are dose-dependent and that BL application alleviates salt stress on potato by improving root activity, root/shoot ratio, and antioxidative capacity in shoots and maintaining K+/Na+ homeostasis in potato shoots and roots. PMID:27803931

  17. Bilobalide alleviates depression-like behavior and cognitive deficit induced by chronic unpredictable mild stress in mice.

    PubMed

    Wu, Ruiyong; Shui, Li; Wang, Siyang; Song, Zhenzhen; Tai, Fadao

    2016-10-01

    Bilobalide (BB), a unique constituent of Ginkgo biloba, has powerful neuroprotection and stress-alleviating properties. However, whether BB exerts a positive effect on depression and cognitive deficit induced by chronic stress is not known. The present study was designed to investigate the influence of BB on depression and cognitive impairments induced by chronic unpredictable mild stress (CUMS) in mice. During daily exposure to stressors for 5 consecutive weeks, mice were administered BB at the doses of 0, 3, or 6 mg/kg/day intraperitoneally. We replicated the finding that CUMS induced depression-like behavior and cognitive deficits as the CUMS+vehicle (VEH) group showed a significant increase in immobility in the tail suspension test, a decrease in the discrimination index of the novel object recognition task, and increased latency to platform and decreased number of platform crossings in the Morris water maze compared with the control+VEH group. Chronic administration of BB effectively reversed these alterations. In addition, the CUMS+VEH group showed significantly higher levels of baseline serum corticosterone than those of the control+VEH group and BB dose-dependently inhibited this effect. Our results suggest that BB may be useful for inhibition of depression-like behavior and cognitive deficits, and this protective effect was possibly exerted partly through an action on the hypothalamic-pituitary-adrenal axis.

  18. Physical and virtual water transfers for regional water stress alleviation in China

    PubMed Central

    Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R.; Guan, Dabo; Hubacek, Klaus

    2015-01-01

    Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management. PMID:25583516

  19. Spermine Alleviates Drought Stress in White Clover with Different Resistance by Influencing Carbohydrate Metabolism and Dehydrins Synthesis

    PubMed Central

    Li, Zhou; Jing, Wen; Peng, Yan; Zhang, Xin Quan; Ma, Xiao; Huang, Lin Kai; Yan, Yan-hong

    2015-01-01

    The objective of this research was to analyse whether ameliorating drought stress through exogenously applied spermine (Spm) was related to carbohydrate metabolism, dehydrins accumulation and the transcription of genes encoding dehydrins in two white clovers (drought-susceptible cv. ‘Ladino’ and drought-resistant cv. ‘Haifa’) under controlled drying conditions for 10 days. The results show that the application of Spm effectively alleviates negative effects caused by drought stress in both cultivars. Exogenous Spm led to accumulation of more water-soluble carbohydrates (WSC), sucrose, fructose and sorbitol in both cultivars under drought stress, and also significantly elevated glucose content in leaves of drought-resistant cv. ‘Haifa’, but had no effect on drought-susceptible cv. ‘Ladino’. Accordingly, the key enzyme activities of sucrose and sorbitol metabolism changed along with the application of Spm under drought stress. Spm induced a significant increase in sucrose phosphate synthase (SPS) or sorbitol dehydrogenase (SDH) activity, but decrease in sucrose synthetase (SS) activity when two cultivars were subjected to drought. In addition, the improved accumulation of dehydrins induced by exogenous Spm coincided with three genes expression which was responsible for dehydrins synthesis. But Spm-induced transcript level of dehydrin genes increased earlier in cv. ‘Ladino’ than that in cv. ‘Haifa’. Thus, these results suggest that ameliorating drought stress through exogenously applied Spm may be associated with increased carbohydrate accumulation and dehydrins synthesis. There are differences between drought-susceptible and -resistant white clover cultivars related to Spm regulation of WSC metabolism and dehydrins expression. PMID:25835290

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

    PubMed

    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.

  1. ER stress drives Lipocalin 2 upregulation in prostate cancer cells in an NF-κB-dependent manner

    PubMed Central

    2011-01-01

    Background Tumor cells adapt to endoplasmic reticulum (ER) stress through a set of conserved intracellular pathways, as part of a process termed the unfolded protein response (UPR). The expression of UPR genes/proteins correlates with increasing progression and poor clinical outcome of several tumor types, including prostate cancer. UPR signaling can activate NF-κB, a master regulator of transcription of pro-inflammatory, tumorigenic cytokines. Previous studies have shown that Lipocalin 2 (Lcn2) is upregulated in several epithelial cancers, including prostate cancer, and recently Lcn2 was implicated as a key mediator of breast cancer progression. Here, we hypothesize that the tumor cell UPR regulates Lcn2 production. Methods We interrogated Lcn2 regulation in murine and human prostate cancer cells undergoing pharmacological and physiological ER stress, and tested UPR and NF-κB dependence by using pharmacological inhibitors of these signaling pathways. Results Induction of ER stress using thapsigargin (Tg), a canonical pharmacologic ER stress inducer, or via glucose deprivation, a physiologic ER stressor present in the tumor microenvironment, upregulates LCN2 production in murine and human prostate cancer cells. Inhibition of the UPR using 4-phenylbutyric acid (PBA) dramatically decreases Lcn2 transcription and translation. Inhibition of NF-κB in prostate cancer cells undergoing Tg-mediated ER stress by BAY 11-7082 abrogates Lcn2 upregulation. Conclusions We conclude that the UPR activates Lcn2 production in prostate cancer cells in an NF-κB-dependent manner. Our results imply that the observed upregulation of Lipocalin 2 in various types of cancer cells may be the direct consequence of concomitant UPR activation, and that the ER stress/Lipocalin 2 axis is a potential new target for intervention in cancer progression. PMID:21649922

  2. Ethylene production is associated with alleviation of cadmium-induced oxidative stress by sulfur in mustard types differing in ethylene sensitivity.

    PubMed

    Asgher, Mohd; Khan, Nafees A; Khan, M Iqbal R; Fatma, Mehar; Masood, Asim

    2014-08-01

    We studied the response of ethylene-sensitive (Pusa Jai Kisan) and ethylene-insensitive (SS2) mustard (Brassica juncea) cultivars to 0, 0.5, 1.0 and 2.0 mM SO₄(2-), and the effect of 1.0 mM SO₄(2-) was studied in the amelioration of 50 µM cadmium (Cd). The Cd-induced oxidative stress and Cd accumulation were greater in SS2 than Pusa Jai Kisan, but sulfur (S) application alleviated Cd-induced oxidative stress more prominently in Pusa Jai Kisan by increasing S-metabolism and synthesis of reduced glutathione (GSH) and ethylene production; and promoted photosynthesis and plant dry mass under Cd stress. The ethylene-sensitive cultivar responded more to S treatment under Cd stress and showed increased activity of antioxidant system resulting in increased photosynthesis and growth. Cadmium treatment resulted in rapid increase in ethylene formation which adversely influenced photosynthesis and plant dry mass. However, S and ethephon application to Cd-treated plants lowered ethylene formation to optimal range responsible for maximal GSH synthesis and protection against Cd-induced oxidative stress. The similarity of the effectiveness of 1.0 mM SO₄(2-) with 200 µL L(-1) ethylene source as ethephon in alleviation of 50 µM Cd further verifies that differential alleviation of Cd toxicity in the two cultivars by S was dependent on ethylene production. The results suggest that ethylene production determines Cd stress alleviation by S via regulatory interaction with antioxidant metabolism. Thus, ethylene production and sensitivity bear a prominent role in alleviation of Cd stress by S and can be used as a criterion for developing Cd tolerant genotypes.

  3. Brassinolide alleviates salt stress and increases antioxidant activity of cowpea plants (Vigna sinensis).

    PubMed

    El-Mashad, Ali Abdel Aziz; Mohamed, Heba Ibrahim

    2012-07-01

    Soil salinity is one of the most severe factors limiting growth and physiological response in Vigna sinensis plants. Plant salt stress tolerance requires the activation of complex metabolic activities including antioxidative pathways, especially reactive oxygen species and scavenging systems within the cells which can contribute to continued growth under water stress. The present investigation was carried out to study the role of brassinolide in enhancing tolerance of cowpea plants to salt stress (NaCl). Treatment with 0.05 ppm brassinolide as foliar spray mitigated salt stress by inducing enzyme activities responsible for antioxidation, e.g., superoxide dismutase, peroxidase, polyphenol oxidase, and detoxification as well as by elevating contents of ascorbic acid, tocopherol, and glutathione. On the other hand, total soluble proteins decreased with increasing NaCl concentrations in comparison with control plants. However, lipid peroxidation increased with increasing concentrations of NaCl. In addition to, the high concentrations of NaCl (100 and 150 mM) decreased total phenol of cowpea plants as being compared with control plants. SDS-PAGE of protein revealed that NaCl treatments alone or in combination with 0.05 ppm brassinolide were associated with the disappearance of some bands or appearance of unique ones in cowpea plants. Electrophoretic studies of α-esterase, β-esterase, polyphenol oxidase, peroxidase, acid phosphatase, and superoxide dismutase isoenzymes showed wide variations in their intensities and densities among all treatments.

  4. Curcumin induces ER stress-mediated apoptosis through selective generation of reactive oxygen species in cervical cancer cells.

    PubMed

    Kim, Boyun; Kim, Hee Seung; Jung, Eun-Ji; Lee, Jung Yun; K Tsang, Benjamin; Lim, Jeong Mook; Song, Yong Sang

    2016-05-01

    Prolonged accumulation of misfolded or unfolded proteins caused by cellular stress, including oxidative stress, induces endoplasmic reticulum stress, which then activates an unfolded protein response (UPR). ER stress is usually maintained at higher levels in cancer cells as compared to normal cells due to altered metabolism in cancer. Here, we investigated whether curcumin is ER stress-mediated apoptosis in cervical cancer cells, and ROS increased by curcumin are involved in the process as an upstream contributor. Curcumin inhibited proliferation of cervical cancer cells (C33A, CaSki, HeLa, and ME180) and induced apoptotic cell death. Curcumin activated ER-resident UPR sensors, such as PERK, IRE-1α, and ATF6, and their downstream-signaling proteins in cervical cancer cells, but not in normal epithelial cells and peripheral blood mononuclear cells (PBMCs). CHOP, a key factor involved in ER stress-mediated apoptosis, was also activated by curcumin. CHOP decreased the ratio of anti-apoptotic protein Bcl-2 to pro-apoptotic protein Bax expression, and subsequently increased the apoptotic population of cervical cancer cells. Furthermore, curcumin elevated levels of intracellular reactive oxygen species (ROS) in cervical cancer cells, but not in normal epithelial cells. Scavenging ROS resulted in inhibition of ER stress and partially restored cell viability in curcumin-treated cancer cells. Collectively, these observations show that curcumin promotes ER stress-mediated apoptosis in cervical cancer cells through increase of cell type-specific ROS generation. Therefore, modulation of these differential responses to curcumin between normal and cervical cancer cells could be an effective therapeutic strategy without adverse effects on normal cells.

  5. ER Stress Sensor XBP1 Controls Anti-tumor Immunity by Disrupting Dendritic Cell Homeostasis.

    PubMed

    Cubillos-Ruiz, Juan R; Silberman, Pedro C; Rutkowski, Melanie R; Chopra, Sahil; Perales-Puchalt, Alfredo; Song, Minkyung; Zhang, Sheng; Bettigole, Sarah E; Gupta, Divya; Holcomb, Kevin; Ellenson, Lora H; Caputo, Thomas; Lee, Ann-Hwee; Conejo-Garcia, Jose R; Glimcher, Laurie H

    2015-06-18

    Dendritic cells (DCs) are required to initiate and sustain T cell-dependent anti-cancer immunity. However, tumors often evade immune control by crippling normal DC function. The endoplasmic reticulum (ER) stress response factor XBP1 promotes intrinsic tumor growth directly, but whether it also regulates the host anti-tumor immune response is not known. Here we show that constitutive activation of XBP1 in tumor-associated DCs (tDCs) drives ovarian cancer (OvCa) progression by blunting anti-tumor immunity. XBP1 activation, fueled by lipid peroxidation byproducts, induced a triglyceride biosynthetic program in tDCs leading to abnormal lipid accumulation and subsequent inhibition of tDC capacity to support anti-tumor T cells. Accordingly, DC-specific XBP1 deletion or selective nanoparticle-mediated XBP1 silencing in tDCs restored their immunostimulatory activity in situ and extended survival by evoking protective type 1 anti-tumor responses. Targeting the ER stress response should concomitantly inhibit tumor growth and enhance anti-cancer immunity, thus offering a unique approach to cancer immunotherapy.

  6. Cantharidins Induce ER Stress and a Terminal Unfolded Protein Response in OSCC

    PubMed Central

    Xi, Y.; Garshott, D.M.; Brownell, A.L.; Yoo, G.H.; Lin, H.-S.; Freeburg, T.L.; Yoo, N.G.; Kaufman, R.J.; Callaghan, M.U.

    2015-01-01

    Mortality and morbidity associated with oral squamous cell carcinoma (OSCC) remain unacceptably high with disfiguring treatment options and a death rate of 1 per hour in the United States. The approval of cituximab for advanced OSCC has been the only new treatment for these patients since the 1970s, although it has not significantly increased overall survival. To address the paucity of effective new therapies, we undertook a high-throughput screen to discover small molecules and natural products that could induce endoplasmic reticulum (ER) stress and enforce a terminal unfolded protein response (UPR) in OSCC. The terpenoid cantharidin (CNT), previously used to treat various malignancies in culture-specific medical practices for over 2,000 y, emerged as a hit. CNT and its analog, cantharidic acid, potently induced protein and gene expression profiles consistent with the activation of ER stress, the UPR, and apoptosis in OSCC cells. Murine embryonic fibroblasts null for the UPR-associated transcription factors Atf4 or Chop were significantly protected from CNT, implicating a key role for the UPR in the death response. These data validate that our high-throughput screen can identify novel modulators of UPR signaling and that such compounds might provide a new therapeutic approach to treating patients with OSCC. PMID:25425581

  7. ER Stress Sensor XBP1 Controls Anti-tumor Immunity by Disrupting Dendritic Cell Homeostasis

    PubMed Central

    Cubillos-Ruiz, Juan R.; Silberman, Pedro C.; Rutkowski, Melanie R.; Chopra, Sahil; Perales-Puchalt, Alfredo; Song, Minkyung; Zhang, Sheng; Bettigole, Sarah E.; Gupta, Divya; Holcomb, Kevin; Ellenson, Lora H.; Caputo, Thomas; Lee, Ann-Hwee; Conejo-Garcia, Jose R.; Glimcher, Laurie H.

    2015-01-01

    SUMMARY Dendritic cells (DCs) are required to initiate and sustain T cell-dependent anti-cancer immunity. However, tumors often evade immune control by crippling normal DC function. The endoplasmic reticulum (ER) stress response factor XBP1 promotes intrinsic tumor growth directly, but whether it also regulates the host anti-tumor immune response is not known. Here we show that constitutive activation of XBP1 in tumor-associated DCs (tDCs) drives ovarian cancer (OvCa) progression by blunting anti-tumor immunity. XBP1 activation, fueled by lipid peroxidation byproducts, induced a triglyceride biosynthetic program in tDCs leading to abnormal lipid accumulation and subsequent inhibition of tDC capacity to support anti-tumor T cells. Accordingly, DC-specific XBP1 deletion or selective nanoparticle-mediated XBP1 silencing in tDCs restored their immunostimulatory activity in situ and extended survival by evoking protective type 1 anti-tumor responses. Targeting the ER stress response should concomitantly inhibit tumor growth and enhance anti-cancer immunity, thus offering a unique approach to cancer immunotherapy. PMID:26073941

  8. Etoposide Induces Apoptosis in Activated Human Hepatic Stellate Cells via ER Stress

    PubMed Central

    Wang, Chen; Zhang, Feng; Cao, Yu; Zhang, Mingming; Wang, Aixiu; Xu, Mingcui; Su, Min; Zhang, Ming; Zhuge, Yuzheng

    2016-01-01

    The activation of hepatic stellate cells (HSCs) plays a vital role in the progression of liver fibrosis, and the induction of HSCs apoptosis may attenuate or reverse fibrogenesis. The therapeutic effects of etoposide(VP-16), a widely used anticancer agent, on HSCs apoptosis and liver fibrosis resolution are still unclear. Here, we report that VP-16 reduced the proliferation of LX-2 cells and led to significantly high levels of apoptosis, as indicated by Annexin V staining and the proteolytic cleavage of the executioner caspase-3 and PARP. Additionally, the unfolded protein response regulators CHOP, BIP, caspase-12, p-eIF2α and IRE1α, which are considered endoplasmic reticulum (ER) stress markers, were upregulated by VP-16. The strong inhibitory effect of VP-16 on LX-2 cells was mainly dependent on ER stress, which activated JNK signaling pathway. Remarkably, VP-16 treatment decreased the expression of α-SMA and type I collagen and simultaneously increased the ratio of matrix metalloproteinases (MMPs) to tissue inhibitor of matrix metalloproteinases (TIMPs). In contrast, VP-16 induced significantly more apoptosis in HSCs than in normal hepatocytes. Taken together, our findings demonstrate that VP-16 exerts a proapoptotic effect on LX-2 cells and has an antifibrogenic effect on collagen deposition, suggesting a new strategy for the treatment of liver fibrosis. PMID:27680712

  9. Basal autophagy maintains pancreatic acinar cell homeostasis and protein synthesis and prevents ER stress

    PubMed Central

    Antonucci, Laura; Fagman, Johan B.; Kim, Ju Youn; Todoric, Jelena; Gukovsky, Ilya; Mackey, Mason; Ellisman, Mark H.; Karin, Michael

    2015-01-01

    Pancreatic acinar cells possess very high protein synthetic rates as they need to produce and secrete large amounts of digestive enzymes. Acinar cell damage and dysfunction cause malnutrition and pancreatitis, and inflammation of the exocrine pancreas that promotes development of pancreatic ductal adenocarcinoma (PDAC), a deadly pancreatic neoplasm. The cellular and molecular mechanisms that maintain acinar cell function and whose dysregulation can lead to tissue damage and chronic pancreatitis are poorly understood. It was suggested that autophagy, the principal cellular degradative pathway, is impaired in pancreatitis, but it is unknown whether impaired autophagy is a cause or a consequence of pancreatitis. To address this question, we generated Atg7Δpan mice that lack the essential autophagy-related protein 7 (ATG7) in pancreatic epithelial cells. Atg7Δpan mice exhibit severe acinar cell degeneration, leading to pancreatic inflammation and extensive fibrosis. Whereas ATG7 loss leads to the expected decrease in autophagic flux, it also results in endoplasmic reticulum (ER) stress, accumulation of dysfunctional mitochondria, oxidative stress, activation of AMPK, and a marked decrease in protein synthetic capacity that is accompanied by loss of rough ER. Atg7Δpan mice also exhibit spontaneous activation of regenerative mechanisms that initiate acinar-to-ductal metaplasia (ADM), a process that replaces damaged acinar cells with duct-like structures. PMID:26512112

  10. Involvement of TR3/Nur77 translocation to the endoplasmic reticulum in ER stress-induced apoptosis

    SciTech Connect

    Liang Bin; Song Xuhong; Liu Gefei; Li Rui; Xie Jianping; Xiao Lifeng; Du Mudan; Zhang Qiaoxia; Xu Xiaoyuan; Gan Xueqiong; Huang Dongyang . E-mail: huangdy@stu.edu.cn

    2007-08-01

    Nuclear orphan receptor TR3/Nur77/NGFI-B is a novel apoptotic effector protein that initiates apoptosis largely by translocating from the nucleus to the mitochondria, causing the release of cytochrome c. However, it is possible that TR3 translocates to other organelles. The present study was designed to determine the intracellular localization of TR3 following CD437-induced nucleocytoplasmic translocation and the mechanisms involved in TR3-induced apoptosis. In human neuroblastoma SK-N-SH cells and human esophageal squamous carcinoma EC109 and EC9706 cells, 5 {mu}M CD437 induced translocation of TR3 to the endoplasmic reticulum (ER). This distribution was confirmed by immunofluorescence analysis, subcellular fractionation analysis and coimmunoprecipitation analysis. The translocated TR3 interacted with ER-targeting Bcl-2; initiated an early release of Ca{sup 2+} from ER; resulted in ER stress and induced apoptosis through ER-specific caspase-4 activation, together with induction of mitochondrial stress and subsequent activation of caspase-9. Our results identified a novel distribution of TR3 in the ER and defined two parallel mitochondrial- and ER-based pathways that ultimately result in apoptotic cell death.

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

    PubMed

    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.

  12. MZB1 is a GRP94 cochaperone that enables proper immunoglobulin heavy chain biosynthesis upon ER stress

    PubMed Central

    Rosenbaum, Marc; Andreani, Virginia; Kapoor, Tanya; Herp, Simone; Flach, Henrik; Duchniewicz, Marlena; Grosschedl, Rudolf

    2014-01-01

    MZB1 (pERp1) is a B-cell-specific and endoplasmic reticulum (ER)-localized protein implicated in antibody secretion and integrin-mediated cell adhesion. Here, we examine the role of MZB1 in vivo by conditional gene inactivation in the mouse germline and at different stages of B lymphopoiesis. Deletion of MZB1 impairs humoral immune responses and antibody secretion in plasma cells that naturally undergo ER stress. In addition, we found that experimental induction of ER stress by tunicamycin injections in mice results in a block of pro-B-cell to pre-B-cell differentiation specifically in Mzb1−/− mice. A similar developmental block was observed in Mzb1fl/flmb1Cre mice, whereby a Cre recombinase-induced genotoxic stress unmasks a role for MZB1 in the surface expression of immunoglobulin µ heavy chains (µHCs). MZB1 associates directly with the substrate-specific chaperone GRP94 (also called HSP90B1 or gp96) in an ATP-sensitive manner and is required for the interaction of GRP94 with µHCs upon ER stress. Thus, MZB1 seems to act as a substrate-specific cochaperone of GRP94 that enables proper biosynthesis of µHCs under conditions of ER stress. PMID:24888588

  13. Eucommia ulmoides Oliver Extract, Aucubin, and Geniposide Enhance Lysosomal Activity to Regulate ER Stress and Hepatic Lipid Accumulation

    PubMed Central

    Lee, Hwa-Young; Lee, Geum-Hwa; Lee, Mi-Rin; Kim, Hye-Kyung; Kim, Nan-young; Kim, Seung-Hyun; Lee, Yong-Chul; Kim, Hyung-Ryong; Chae, Han-Jung

    2013-01-01

    Eucommia ulmoides Oliver is a natural product widely used as a dietary supplement and medicinal plant. Here, we examined the potential regulatory effects of Eucommia ulmoides Oliver extracts (EUE) on hepatic dyslipidemia and its related mechanisms by in vitro and in vivo studies. EUE and its two active constituents, aucubin and geniposide, inhibited palmitate-induced endoplasmic reticulum (ER) stress, reducing hepatic lipid accumulation through secretion of apolipoprotein B and associated triglycerides and cholesterol in human HepG2 hepatocytes. To determine how EUE diminishes the ER stress response, lysosomal and proteasomal protein degradation activities were analyzed. Although proteasomal activity was not affected, lysosomal enzyme activities including V-ATPase were significantly increased by EUE as well as aucubin and geniposide in HepG2 cells. Treatment with the V-ATPase inhibitor, bafilomycin, reversed the inhibition of ER stress, secretion of apolipoprotein B, and hepatic lipid accumulation induced by EUE or its component, aucubin or geniposide. In addition, EUE was determined to regulate hepatic dyslipidemia by enhancing lysosomal activity and to regulate ER stress in rats fed a high-fat diet. Together, these results suggest that EUE and its active components enhance lysosomal activity, resulting in decreased ER stress and hepatic dyslipidemia. PMID:24349058

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

    PubMed

    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. PMID:27121014

  15. Pachymic acid inhibits growth and induces apoptosis of pancreatic cancer in vitro and in vivo by targeting ER stress.

    PubMed

    Cheng, Shujie; Swanson, Kristen; Eliaz, Isaac; McClintick, Jeanette N; Sandusky, George E; Sliva, Daniel

    2015-01-01

    Pachymic acid (PA) is a purified triterpene extracted from medicinal fungus Poria cocos. In this paper, we investigated the anticancer effect of PA on human chemotherapy resistant pancreatic cancer. PA triggered apoptosis in gemcitabine-resistant pancreatic cancer cells PANC-1 and MIA PaCa-2. Comparative gene expression array analysis demonstrated that endoplasmic reticulum (ER) stress was induced by PA through activation of heat shock response and unfolded protein response related genes. Induced ER stress was confirmed by increasing expression of XBP-1s, ATF4, Hsp70, CHOP and phospho-eIF2α. Moreover, ER stress inhibitor tauroursodeoxycholic acid (TUDCA) blocked PA induced apoptosis. In addition, 25 mg kg-1 of PA significantly suppressed MIA PaCa-2 tumor growth in vivo without toxicity, which correlated with induction of apoptosis and expression of ER stress related proteins in tumor tissues. Taken together, growth inhibition and induction of apoptosis by PA in gemcitabine-resistant pancreatic cancer cells were associated with ER stress activation both in vitro and in vivo. PA may be potentially exploited for the use in treatment of chemotherapy resistant pancreatic cancer.

  16. Carbon monoxide offers neuroprotection from hippocampal cell damage induced by recurrent febrile seizures through the PERK-activated ER stress pathway.

    PubMed

    Han, Ying; Yi, Wenxia; Qin, Jiong; Zhao, Yang; Zhang, Jing; Chang, Xingzhi

    2015-01-12

    Carbon monoxide (CO) is neuroprotective in various models of brain injury, but the precise mechanisms for this are yet to be established. In the present study, using a rat model of recurrent febrile seizures (FSs), we found an increase in plasma CO, evidence of neuronal damage and apoptosis, an increase in the expression of the endoplasmic reticulum stress (ERS) marker glucose-regulated protein 78 (GRP78) and C/EBP homologous binding protein (CHOP), and an increase in phosphorylated protein kinase RNA-like endoplasmic reticulum kinase (p-PERK)/eukaryotic translation initiation factor 2 alpha (p-eIF2α) in the hippocampus after 10 FSs. Administration of Hemin (a CO donor) in FS rats alleviated the neuronal damage, reduced neuronal apoptosis, upregulated GRP78 expression, decreased CHOP, and increased p-PERK and p-eIF2α expression in the hippocampus, compared to FS control rats. In contrast, treating FS rats with ZnPP-IX (a CO synthase inhibitor) aggravated the neuronal damage, enhanced neuronal apoptosis, downregulated GRP78 expression, increased CHOP, and decreased p-PERK and p-eIF2α expression, compared to FS control rats. These results suggest that endogenous CO limits the neuronal damage induced by recurrent FSs, through the PERK-activated ERS pathway.

  17. Comparative proteomic analysis of β-aminobutyric acid-mediated alleviation of salt stress in barley.

    PubMed

    Mostek, Agnieszka; Börner, Andreas; Weidner, Stanisław

    2016-02-01

    The non-protein amino acid β-aminobutyric acid (BABA) is known to induce plant resistance to a broad spectrum of biotic and abiotic stresses. This is the first study describing the effect of BABA seed priming on physiological and proteomic changes under salt stress conditions in barley (Hordeum vulgare). The aim of our study was to investigate the changes of fresh weight, dry weight and relative water content (RWC) as well as root proteome changes of two barley lines contrasting in salt tolerance (DH14, DH 187) in response to salt stress after seed priming in water or in 800 μM BABA. Seed priming with BABA significantly increased (p ≤ 0.05) RWC in both barley lines, which indicates considerably lower water loss in BABA-primed plants than in the non-primed control plants. Dry and fresh matter increased significantly in line DH 187, whereas no changes were detected in line DH14. BABA-primed plants of both lines showed different proteomic patterns than the non-primed control plants. The root proteins exhibiting significant abundance changes (1.75-fold change, p ≤ 0.05) were separated by two-dimensional polyacrylamide gel electrophoresis (2D- PAGE). Thirty-one spots, representing 24 proteins, were successfully identified by MALDI TOF/TOF mass spectrometry. The most prominent differences include the up-regulation of antioxidant enzymes (catalase, peroxidase and superoxide dismutase), PR proteins (chitinase, endo-1,3-β-glucosidase), and chaperones (cyclophilin, HSC 70). Our results indicate that BABA induces defence and detoxification processes which may enable faster and more effective responses to salt stress, increasing the chances of survival under adverse environmental conditions.

  18. Genome-wide screen identifies a novel p97/CDC-48-dependent pathway regulating ER-stress-induced gene transcription

    PubMed Central

    Marza, Esther; Taouji, Saïd; Barroso, Kim; Raymond, Anne-Aurélie; Guignard, Léo; Bonneu, Marc; Pallares-Lupon, Néstor; Dupuy, Jean-William; Fernandez-Zapico, Martin E; Rosenbaum, Jean; Palladino, Francesca; Dupuy, Denis; Chevet, Eric

    2015-01-01

    The accumulation of misfolded proteins in the endoplasmic reticulum (ER) activates the Unfolded Protein Response (UPRER) to restore ER homeostasis. The AAA+ ATPase p97/CDC-48 plays key roles in ER stress by promoting both ER protein degradation and transcription of UPRER genes. Although the mechanisms associated with protein degradation are now well established, the molecular events involved in the regulation of gene transcription by p97/CDC-48 remain unclear. Using a reporter-based genome-wide RNAi screen in combination with quantitative proteomic analysis in Caenorhabditis elegans, we have identified RUVB-2, a AAA+ ATPase, as a novel repressor of a subset of UPRER genes. We show that degradation of RUVB-2 by CDC-48 enhances expression of ER stress response genes through an XBP1-dependent mechanism. The functional interplay between CDC-48 and RUVB-2 in controlling transcription of select UPRER genes appears conserved in human cells. Together, these results describe a novel role for p97/CDC-48, whereby its role in protein degradation is integrated with its role in regulating expression of ER stress response genes. PMID:25652260

  19. Ageing-Associated Oxidative Stress and Inflammation Are Alleviated by Products from Grapes

    PubMed Central

    Petersen, K. S.

    2016-01-01

    Advanced age is associated with increased incidence of a variety of chronic disease states which share oxidative stress and inflammation as causative role players. Furthermore, data point to a role for both cumulative oxidative stress and low grade inflammation in the normal ageing process, independently of disease. Therefore, arguably the best route with which to address premature ageing, as well as age-associated diseases such as diabetes, cardiovascular disease, and dementia, is preventative medicine aimed at modulation of these two responses, which are intricately interlinked. In this review, we provide a detailed account of the literature on the communication of these systems in the context of ageing, but with inclusion of relevant data obtained in other models. In doing so, we attempted to more clearly elucidate or identify the most probable cellular or molecular targets for preventative intervention. In addition, given the absence of a clear pharmaceutical solution in this context, together with the ever-increasing consumer bias for natural medicine, we provide an overview of the literature on grape (Vitis vinifera) derived products, for which beneficial effects are consistently reported in the context of both oxidative stress and inflammation. PMID:27034739

  20. Overexpression of a tomato carotenoid ε-hydroxylase gene alleviates sensitivity to chilling stress in transgenic tobacco.

    PubMed

    Zhou, Bin; Deng, Yong-Sheng; Kong, Fan-Ying; Li, Bin; Meng, Qing-Wei

    2013-09-01

    Chilling is one of the most serious environmental stresses that disrupt the metabolic balance of cells and enhance the production of reactive oxygen species (ROS). Lutein plays important roles in dissipating excess excitation energy and eliminating ROS to maintain the normal physiological function of cells. A tomato carotenoid epsilon-ring hydroxylase gene (LeLUT1) was isolated, and the LeLUT1-GFP fusion protein was localized in the chloroplast of Arabidopsis mesophyll protoplast. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the expression of LeLUT1 was the highest in the leaves and was down-regulated by various abiotic stresses in tomato. The transgenic tobacco plants overexpressing LeLUT1 had higher lutein content, which was decreased in cold condition. Under chilling stress, the non-photochemical quenching (NPQ) values were higher in the transgenic plants than in the wild type (WT) plants. Compared with the WT plants, the transgenic plants showed lower levels of hydrogen peroxide (H2O2), superoxide radical (O2(·-)), relative electrical conductivity, and malondialdehyde content (MDA), and relatively higher values of maximal photochemical efficiency of photosystem II (Fv/Fm), oxidizable P700 of PSI, and net photosynthetic rate (Pn). Therefore, the transgenic seedlings were less suppressed in growth and lost less cotyledon chlorophyll than the WT seedlings. These results suggested that the overexpression of LeLUT1 had a key function in alleviating photoinhibition and photooxidation, and decreased the sensitivity of photosynthesis to chilling stress. PMID:23796723

  1. Alleviation of Drought Stress by Hydrogen Sulfide Is Partially Related to the Abscisic Acid Signaling Pathway in Wheat

    PubMed Central

    Wang, Chenyang; Qin, Haixia; Han, Qiaoxia; Hou, Junfeng; Lu, Hongfang; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Little information is available describing the effects of exogenous H2S on the ABA pathway in the acquisition of drought tolerance in wheat. In this study, we investigated the physiological parameters, the transcription levels of several genes involved in the abscisic acid (ABA) metabolism pathway, and the ABA and H2S contents in wheat leaves and roots under drought stress in response to exogenous NaHS treatment. The results showed that pretreatment with NaHS significantly increased plant height and the leaf relative water content of seedlings under drought stress. Compared with drought stress treatment alone, H2S application increased antioxidant enzyme activities and reduced MDA and H2O2 contents in both leaves and roots. NaHS pretreatment increased the expression levels of ABA biosynthesis and ABA reactivation genes in leaves; whereas the expression levels of ABA biosynthesis and ABA catabolism genes were up-regulated in roots. These results indicated that ABA participates in drought tolerance induced by exogenous H2S, and that the responses in leaves and roots are different. The transcription levels of genes encoding ABA receptors were up-regulated in response to NaHS pretreatment under drought conditions in both leaves and roots. Correspondingly, the H2S contents in leaves and roots were increased by NaHS pretreatment, while the ABA contents of leaves and roots decreased. This implied that there is complex crosstalk between these two signal molecules, and that the alleviation of drought stress by H2S, at least in part, involves the ABA signaling pathway. PMID:27649534

  2. Berberis vulgaris root extract alleviates the adverse effects of heat stress via modulating hepatic nuclear transcription factors in quails.

    PubMed

    Sahin, Kazim; Orhan, Cemal; Tuzcu, Mehmet; Borawska, Maria H; Jabłonski, Jakub; Guler, Osman; Sahin, Nurhan; Hayirli, Armagan

    2013-08-01

    To evaluate the action mode of Berberis vulgaris root extract in the alleviation of oxidative stress, female Japanese quails (n 180, aged 5 weeks) were reared, either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (heat stress, HS), and fed one of three diets: diets containing 0, 100 or 200 mg of B. vulgaris root extract per kg for 12 weeks. Exposure to HS depressed feed intake by 8·5% and egg production by 12·1%, increased hepatic malondialdehyde (MDA) level by 98·0% and decreased hepatic superoxide dismutase, catalase and glutathione peroxidase activities by 23·5, 35·4 and 55·7%, respectively (P<0·001 for all). There were also aggravations in expressions of hepatic NF-κB and heat-shock protein 70 (HSP70) by 42 and 43%, respectively and suppressions in expressions of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and haeme-oxygenase 1 (HO-1) by 57 and 61%, respectively, in heat-stressed quails (P<0·001 for all). As supplemental B. vulgaris extract increased, there were linear increases in performance parameters, activities of antioxidant enzymes and hepatic Nrf2 and HO-1 expressions (P<0·001 for all) and linear decreases in hepatic MDA level and NF-κB and HSP70 expressions at a greater extent in quails reared under TN condition and those reared under HS condition. In conclusion, dietary supplementation of B. vulgaris root extract to quails reduces the detrimental effects of oxidative stress and lipid peroxidation resulting from HS via activating the host defence system at the cellular level.

  3. Alleviation of Drought Stress by Hydrogen Sulfide Is Partially Related to the Abscisic Acid Signaling Pathway in Wheat.

    PubMed

    Ma, Dongyun; Ding, Huina; Wang, Chenyang; Qin, Haixia; Han, Qiaoxia; Hou, Junfeng; Lu, Hongfang; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Little information is available describing the effects of exogenous H2S on the ABA pathway in the acquisition of drought tolerance in wheat. In this study, we investigated the physiological parameters, the transcription levels of several genes involved in the abscisic acid (ABA) metabolism pathway, and the ABA and H2S contents in wheat leaves and roots under drought stress in response to exogenous NaHS treatment. The results showed that pretreatment with NaHS significantly increased plant height and the leaf relative water content of seedlings under drought stress. Compared with drought stress treatment alone, H2S application increased antioxidant enzyme activities and reduced MDA and H2O2 contents in both leaves and roots. NaHS pretreatment increased the expression levels of ABA biosynthesis and ABA reactivation genes in leaves; whereas the expression levels of ABA biosynthesis and ABA catabolism genes were up-regulated in roots. These results indicated that ABA participates in drought tolerance induced by exogenous H2S, and that the responses in leaves and roots are different. The transcription levels of genes encoding ABA receptors were up-regulated in response to NaHS pretreatment under drought conditions in both leaves and roots. Correspondingly, the H2S contents in leaves and roots were increased by NaHS pretreatment, while the ABA contents of leaves and roots decreased. This implied that there is complex crosstalk between these two signal molecules, and that the alleviation of drought stress by H2S, at least in part, involves the ABA signaling pathway. PMID:27649534

  4. Elevated systemic expression of ER stress related genes is associated with stress-related mental disorders in the Detroit Neighborhood Health Study

    PubMed Central

    Nevell, Lisa; Zhang, Kezhong; Aiello, Allison; Koenen, Karestan; Galea, Sandro; Soliven, Richelo; Zhang, Chao; Wildman, Derek E.; Uddin, Monica

    2014-01-01

    Background The role of Endoplasmic Reticulum (ER) stress response in mental illness is not well understood. Human studies and animal models of depression show elevated brain ER stress response. In addition, some ER stress associated disorders (e.g. cardiovascular disease) show higher rates of depression compared to the general population, raising the possibility that ER stress response contributes to depression risk. It remains unknown, however, if ER stress response is present among individuals suffering from other stress-related mental illness, and whether such a response would be evident in a non-clinical sample. This study tests for systemic changes in ER stress response associated with major depressive disorder (MDD) or post-traumatic stress disorder (PTSD) among community-dwelling individuals. Methods We analyzed expression of BiP, EDEM1, CHOP, and XBP1, the major indicators of ER stress response, with Real-Time PCR in leukocyte-derived RNA samples from 86 participants of the Detroit Neighborhood Health Study. Participants were selected based on the presence of either past year MDD or past year PTSD; controls were age and sex matched. Results Relative to controls, MDD is associated with a 1.34-fold increase in BiP (P=0.004), 1.35-fold increase in EDEM1 (P=0.001), 1.68-fold increase in CHOP (P=0.002), and 1.60-fold increase in XBP1 (P=0.004). These results remained significant after correction for multiple testing. In contrast, PTSD is associated with a 1.27 fold increase in EDEM1 expression only (P=0.027), a result that is attenuated to non-significance following adjustment for multiple testing; however, a subsample of participants with past month PTSD showed elevated expression of BiP and EDEM1 (uncorrected p value 0.049 and 0.017, respectively). Conclusions These data indicate systemic and persistent activation of the ER stress response pathway in MDD among community-dwelling individuals. Systemic activation of the ER stress response may also occur in PTSD

  5. Alleviation effect of arbutin on oxidative stress generated through tyrosinase reaction with l-tyrosine and l-DOPA

    PubMed Central

    2014-01-01

    Background Hydroxyl radical that has the highest reactivity among reactive oxygen species (ROS) is generated through l-tyrosine-tyrosinase reaction. Thus, the melanogenesis might induce oxidative stress in the skin. Arbutin (p-hydroxyphenyl-β-d-glucopyranoside), a well-known tyrosinase inhibitor has been widely used for the purpose of skin whitening. The aim of the present study was to examine if arbutin could suppress the hydroxyl radical generation via tyrosinase reaction with its substrates, l-tyrosine and l-DOPA. Results The hydroxyl radical, which was determined by an electron spin resonance-spin trapping technique, was generated by the addition of not only l-tyrosine but l-DOPA to tyrosinase in a concentration dependent manner. Arbutin could inhibit the hydroxyl radical generation in the both reactions. Conclusion It is presumed that arbutin could alleviate oxidative stress derived from the melanogenic pathway in the skin in addition to its function as a whitening agent in cosmetics. PMID:25297374

  6. Carvedilol alleviates adjuvant-induced arthritis and subcutaneous air pouch edema: modulation of oxidative stress and inflammatory mediators.

    PubMed

    Arab, Hany H; El-Sawalhi, Maha M

    2013-04-15

    Rheumatoid arthritis (RA) is a systemic inflammatory disease with cardiovascular complications as the leading cause of morbidity. Carvedilol is an adrenergic antagonist which has been safely used in treatment of several cardiovascular disorders. Given that carvedilol has powerful antioxidant/anti-inflammatory properties, we aimed to investigate its protective potential against arthritis that may add further benefits for its clinical usefulness especially in RA patients with concomitant cardiovascular disorders. Two models were studied in the same rat; adjuvant arthritis and subcutaneous air pouch edema. Carvedilol (10mg/kg/day p.o. for 21days) effectively suppressed inflammation in both models with comparable efficacy to the standard anti-inflammatory diclofenac (5mg/kg/day p.o.). Notably, carvedilol inhibited paw edema and abrogated the leukocyte invasion to air pouch exudates. The latter observation was confirmed by the histopathological assessment of the pouch lining that revealed mitigation of immuno-inflammatory cell influx. Carvedilol reduced/normalized oxidative stress markers (lipid peroxides, nitric oxide and protein thiols) and lowered the release of inflammatory cytokines (TNF-α & IL-6), and eicosanoids (PGE2 & LTB4) in sera and exudates of arthritic rats. Interestingly, carvedilol, per se, didn't present any effect on assessed biochemical parameters in normal rats. Together, the current study highlights evidences for the promising anti-arthritic effects of carvedilol that could be mediated through attenuation of leukocyte migration, alleviation of oxidative stress and suppression of proinflammatory cytokines and eicosanoids.

  7. Resveratrol alleviates endotoxemia-associated adrenal insufficiency by suppressing oxidative/nitrative stress.

    PubMed

    Duan, Guo-Li; Wang, Chang-Nan; Liu, Yu-Jian; Yu, Qing; Tang, Xiao-Lu; Ni, Xin; Zhu, Xiao-Yan

    2016-06-30

    We have recently demonstrated that endotoxin causes oxidative stress and overproduction of nitric oxide in adrenal glands, thereby leading to adrenocortical insufficiency. The aim of this study is to investigate the effects of resveratrol, a natural plant polyphenol with anti-oxidant and anti-nitrative properties, on endotoxemia-associated adrenocortical insufficiency. Resveratrol was administered immediately before injection of lipopolysaccharide (LPS). Twenty four hours later, the adrenocorticotropic hormone (ACTH) stimulation tests was been performed to measure the plasma corticosterone level and the adrenal gland tissues were collected for histopathologic examination, and determination of malondialdehyde (MDA), total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity, inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO) and peroxynitrite production. Treatment with resveratrol significantly inhibited endotoxemia-induced iNOS expression, NO production, and peroxynitrite formation and also attenuated LPS-induced oxidative stress in the adrenal gland, as evidenced by the decrease of pro-oxidant biomarker (MDA), and the increases of anti-oxidant biomarkers (T-AOC, CAT and SOD activity). H&E staining demonstrated that administration of LPS resulted in increased into the adrenal gland. H&E-stained sections of adrenal glands demonstrated signs of leukocyte infiltration and hemorrhage during endotoxemia, which were significantly improved by resveratrol treatment. In addition, resveratrol reversed the LPS-induced downregulation of ACTH receptor and silent information regulator 1 (SIRT1) in adrenal gland, as well as adrenocortical hyporesponsiveness to ACTH. Resveratrol exerts protective effects against endotoxemia-associated adrenocortical insufficiency by suppressing oxidative/nitrative stress. These findings support the potential for resveratrol as a possible pharmacological agent to improve adrenocortical

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

    PubMed Central

    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

  9. Anticancer compound Oplopantriol A kills cancer cells through inducing ER stress and BH3 proteins Bim and Noxa

    PubMed Central

    Jin, H R; Liao, Y; Li, X; Zhang, Z; Zhao, J; Wang, C-Z; Huang, W-H; Li, S-P; Yuan, C-S; Du, W

    2014-01-01

    Oplopantriol-A (OPT) is a natural polyyne from Oplopanax horridus. We show here that OPT preferentially kills cancer cells and inhibits tumor growth. We demonstrate that OPT-induced cancer cell death is mediated by excessive endoplasmic reticulum (ER) stress. Decreasing the level of ER stress either by inactivating components of the unfolded protein response (UPR) pathway or by expression of ER chaperone protein glucose-regulated protein 78 (GRP78) decreases OPT-induced cell death. We show that OPT induces the accumulation of ubiquitinated proteins and the stabilization of unstable proteins, suggesting that OPT functions, at least in part, through interfering with the ubiquitin/proteasome pathway. In support of this, inhibition of protein synthesis significantly decreased the accumulation of ubiquitinated proteins, which is correlated with significantly decreased OPT-induced ER stress and cell death. Finally, we show that OPT treatment significantly induced the expression of BH3-only proteins, Noxa and Bim. Knockdown of both Noxa and Bim significantly blocked OPT-induced cell death. Taken together, our results suggest that OPT is a potential new anticancer agent that induces cancer cell death through inducing ER stress and BH3 proteins Noxa and Bim. PMID:24763047

  10. Mamao Pomace Extract Alleviates Hypertension and Oxidative Stress in Nitric Oxide Deficient Rats

    PubMed Central

    Kukongviriyapan, Upa; Kukongviriyapan, Veerapol; Pannangpetch, Patchareewan; Donpunha, Wanida; Sripui, Jintana; Sae-Eaw, Amporn; Boonla, Orachorn

    2015-01-01

    Reactive oxygen species (ROS)-induced oxidative stress plays a major role in pathogenesis of hypertension. Antidesma thwaitesianum (local name: Mamao) is a tropical plant distributed in the tropical/subtropical areas of the world, including Thailand. Mamao pomace (MP), a by-product generated from Mamao fruits, contains large amounts of antioxidant polyphenolic compounds. The aim of this study was to investigate the antihypertensive and antioxidative effects of MP using hypertensive rats. For this purpose, male Sprague-Dawley rats were given Nω-nitro-l-arginine methyl ester (l-NAME), an inhibitor of endothelial nitric oxide synthase (eNOS), in drinking water (50 mg/kg) for three weeks. MP extract was orally administered daily at doses of 100 and 300 mg/kg. l-NAME administration induced marked increase in blood pressure, peripheral vascular resistance, and oxidative stress. MP treatment significantly prevented the increase in blood pressure, hindlimb blood flow and hindlimb vascular resistance of l-NAME treated hypertensive rats (p < 0.05). The antihypertensive effect of MP treatment was associated with suppression of superoxide production from carotid strips and also with an increase in eNOS protein expression and nitric oxide bioavailability. The present results provide evidence for the antihypertensive effect of MP and suggest that MP might be useful as a dietary supplement against hypertension. PMID:26225998

  11. P21Cip1 Protects against Oxidative Stress by Suppressing ER Dependent Activation of Mitochondrial Death Pathways

    PubMed Central

    Vitiello, Peter F.; Wu, Yu-Chieh M.; Staversky, Rhonda J.; O’Reilly, Michael A.

    2009-01-01

    Although it is well established that the cell cycle inhibitor p21 protects against genotoxic stress by preventing the replication of damaged DNA, recent studies have shown cytoplasmic forms can also protect. It protects by delaying the loss of the anti-apoptotic proteins, Mcl-1 and Bcl-XL; however, the mechanism of regulation is unknown. Utilizing hyperoxia as a model of chronic oxidative stress and DNA damage, p21 was detected in the nucleus and cytoplasm and cytoplasmic expression of p21 was sufficient for cytoprotection. P21 was enriched in a subcellular fraction containing mitochondria and endoplasmic reticulum (ER), suggesting that it may be coordinating ER and mitochondrial stress pathways. Consistent with this, p21 suppressed hyperoxic downregulation of BiP and subsequent activation ER stress signaling which effected Mcl-1, but not Bcl-XL; though both inhibited hyperoxic cell death. Taken together, these data show that p21 integrates the DNA damage response with ER stress signaling which then regulates mitochondrial death pathways during chronic genotoxic stress. PMID:18948188

  12. ER stress upregulated PGE2/IFNγ-induced IL-6 expression and down-regulated iNOS expression in glial cells

    NASA Astrophysics Data System (ADS)

    Hosoi, Toru; Honda, Miya; Oba, Tatsuya; Ozawa, Koichiro

    2013-12-01

    The disruption of endoplasmic reticulum (ER) function can lead to neurodegenerative disorders, in which inflammation has also been implicated. We investigated the possible correlation between ER stress and immune function using glial cells. We demonstrated that ER stress synergistically enhanced prostaglandin (PG) E2 + interferon (IFN) γ-induced interleukin (IL)-6 production. This effect was mediated through cAMP. Immune-activated glial cells produced inducible nitric oxide synthase (iNOS). Interestingly, ER stress inhibited PGE2 + IFNγ-induced iNOS expression. Similar results were obtained when cells were treated with dbcAMP + IFNγ. Thus, cAMP has a dual effect on immune reactions; cAMP up-regulated IL-6 expression, but down-regulated iNOS expression under ER stress. Therefore, our results suggest a link between ER stress and immune reactions in neurodegenerative diseases.

  13. Dietary sodium butyrate alleviates the oxidative stress induced by corticosterone exposure and improves meat quality in broiler chickens.

    PubMed

    Zhang, W H; Gao, F; Zhu, Q F; Li, C; Jiang, Y; Dai, S F; Zhou, G H

    2011-11-01

    The present study was to investigate the effects of dietary microencapsulated sodium butyrate (SB) and acute pre-slaughter stress, mimicked by subcutaneous corticosterone (CORT) administration, on BW, carcass characteristics, muscle antioxidant status, and meat quality of broiler chickens. A total of 120 1-d-old broiler chickens were fed a control diet (without SB) or a 0.4-g microencapsulated SB/kg diet. On 42 d, half of the birds from each treatment were given 1 single subcutaneous injection of CORT (4 mg/kg of BW in corn oil) to mimic acute stress, whereas the other half were injected with the same amount of corn oil (sham control). Three hours later, BW loss was determined and breast meat samples were collected. The results showed that the BW of the CORT-challenged groups lost much more than the sham control group (P < 0.001), whereas it was alleviated by the dietary microencapsulated SB (P < 0.05). Meanwhile, the catalase activity was decreased and malondialdehyde level was increased by the stress (P < 0.05), and the microencapsulated-SB diet significantly inhibited this effect (P < 0.05). Lower pH values and higher yellowness values were also observed in CORT-challenged chickens (P < 0.05), and the microencapsulated-SB diet treatment partially exerted a preventive effect. Microencapsulated SB significantly decreased the contents of saturated fatty acids and C18:0 (P < 0.01 and P < 0.001), and increased C20:0 and C20:4 contents. However, the effect of the stress treatment on fatty acid composition was insignificant (P > 0.05). In addition, diet and stress did not significantly influence carcass characteristics and the chemical composition of breast meat (P > 0.05). These results suggest that microencapsulated SB was favorable for chickens in the presence of stress, which may be partially ascribed to the ability of SB to decrease catabolism and oxidative injury of tissues.

  14. Carvedilol alleviates adjuvant-induced arthritis and subcutaneous air pouch edema: Modulation of oxidative stress and inflammatory mediators

    SciTech Connect

    Arab, Hany H.; El-Sawalhi, Maha M.

    2013-04-15

    Rheumatoid arthritis (RA) is a systemic inflammatory disease with cardiovascular complications as the leading cause of morbidity. Carvedilol is an adrenergic antagonist which has been safely used in treatment of several cardiovascular disorders. Given that carvedilol has powerful antioxidant/anti-inflammatory properties, we aimed to investigate its protective potential against arthritis that may add further benefits for its clinical usefulness especially in RA patients with concomitant cardiovascular disorders. Two models were studied in the same rat; adjuvant arthritis and subcutaneous air pouch edema. Carvedilol (10 mg/kg/day p.o. for 21 days) effectively suppressed inflammation in both models with comparable efficacy to the standard anti-inflammatory diclofenac (5 mg/kg/day p.o.). Notably, carvedilol inhibited paw edema and abrogated the leukocyte invasion to air pouch exudates. The latter observation was confirmed by the histopathological assessment of the pouch lining that revealed mitigation of immuno-inflammatory cell influx. Carvedilol reduced/normalized oxidative stress markers (lipid peroxides, nitric oxide and protein thiols) and lowered the release of inflammatory cytokines (TNF-α and IL-6), and eicosanoids (PGE{sub 2} and LTB{sub 4}) in sera and exudates of arthritic rats. Interestingly, carvedilol, per se, didn't present any effect on assessed biochemical parameters in normal rats. Together, the current study highlights evidences for the promising anti-arthritic effects of carvedilol that could be mediated through attenuation of leukocyte migration, alleviation of oxidative stress and suppression of proinflammatory cytokines and eicosanoids. - Highlights: ► Carvedilol possesses promising anti-arthritic properties. ► It markedly suppressed inflammation in adjuvant arthritis and air pouch edema. ► It abrogated the leukocyte invasion to air pouch exudates and linings. ► It reduced/normalized oxidative stress markers in sera and exudates of

  15. DEFECTIVE TRAFFICKING OF CONE PHOTORECEPTOR CNG CHANNELS INDUCES THE UNFOLDED PROTEIN RESPONSE AND ER STRESS-ASSOCIATED CELL DEATH

    PubMed Central

    Duricka, Deborah L.; Brown, R. Lane; Varnum, Michael D.

    2011-01-01

    SYNOPSIS Mutations that perturb the function of photoreceptor cyclic nucleotide-gated (CNG) channels are associated with several human retinal disorders, but the molecular and cellular mechanisms leading to photoreceptor dysfunction and degeneration remain unclear. Many loss-of-function mutations result in intracellular accumulation of CNG channel subunits. Accumulation of proteins in the endoplasmic reticulum (ER) is known to cause ER stress and trigger the unfolded protein response (UPR), an evolutionarily conserved cellular program that results in either adaptation via increased protein processing capacity or apoptotic cell death. We hypothesize that defective trafficking of cone photoreceptor CNG channels can induce UPR-mediated cell death. To test this idea, CNGA3 subunits bearing the R563H and Q655X mutations were expressed in photoreceptor-derived 661W cells with CNGB3 subunits. Compared to wild type, R563H and Q655X subunits displayed altered degradation rates and/or were retained in the ER. ER retention was associated with increased expression of UPR-related markers of ER stress and with decreased cell viability. Chemical and pharmacological chaperones (TUDCA, 4PBA, and the cGMP analog CPT-cGMP) differentially reduced degradation and/or promoted plasma-membrane localization of defective subunits. Improved subunit maturation was concordant with reduced expression of ER stress markers and improved viability of cells expressing localization-defective channels. These results indicate that ER stress can arise from expression of localization defective CNG channels, and may represent a contributing factor for photoreceptor degeneration. PMID:21992067

  16. Arbuscular mycorrhizal symbiosis elicits shoot proteome changes that are modified during cadmium stress alleviation in Medicago truncatula

    PubMed Central

    2011-01-01

    Background Arbuscular mycorrhizal (AM) fungi, which engage a mutualistic symbiosis with the roots of most plant species, have received much attention for their ability to alleviate heavy metal stress in plants, including cadmium (Cd). While the molecular bases of Cd tolerance displayed by mycorrhizal plants have been extensively analysed in roots, very little is known regarding the mechanisms by which legume aboveground organs can escape metal toxicity upon AM symbiosis. As a model system to address this question, we used Glomus irregulare-colonised Medicago truncatula plants, which were previously shown to accumulate and tolerate heavy metal in their shoots when grown in a substrate spiked with 2 mg Cd kg-1. Results The measurement of three indicators for metal phytoextraction showed that shoots of mycorrhizal M. truncatula plants have a capacity for extracting Cd that is not related to an increase in root-to-shoot translocation rate, but to a high level of allocation plasticity. When analysing the photosynthetic performance in metal-treated mycorrhizal plants relative to those only Cd-supplied, it turned out that the presence of G. irregulare partially alleviated the negative effects of Cd on photosynthesis. To test the mechanisms by which shoots of Cd-treated mycorrhizal plants avoid metal toxicity, we performed a 2-DE/MALDI/TOF-based comparative proteomic analysis of the M. truncatula shoot responses upon mycorrhization and Cd exposure. Whereas the metal-responsive shoot proteins currently identified in non-mycorrhizal M. truncatula indicated that Cd impaired CO2 assimilation, the mycorrhiza-responsive shoot proteome was characterised by an increase in photosynthesis-related proteins coupled to a reduction in glugoneogenesis/glycolysis and antioxidant processes. By contrast, Cd was found to trigger the opposite response coupled the up-accumulation of molecular chaperones in shoot of mycorrhizal plants relative to those metal-free. Conclusion Besides drawing a

  17. Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway

    PubMed Central

    Li, Qing-rong; Wang, Zhuo; Zhou, Wei; Fan, Shou-rui; Ma, Run; Xue, Li; Yang, Lu; Li, Ya-shan; Tan, Hong-li; Shao, Qing-hua; Yang, Hong-ying

    2016-01-01

    Epalrestat is a noncompetitive and reversible aldose reductase inhibitor used for the treatment of diabetic neuropathy. This study assumed that epalrestat had a protective effect on diabetic peripheral nerve injury by suppressing the expression of aldose reductase in peripheral nerves of diabetes mellitus rats. The high-fat and high-carbohydrate model rats were established by intraperitoneal injection of streptozotocin. Peripheral neuropathy occurred in these rats after sustaining high blood glucose for 8 weeks. At 12 weeks after streptozotocin injection, rats were intragastrically administered epalrestat 100 mg/kg daily for 6 weeks. Transmission electron microscope revealed that the injuries to myelinated nerve fibers, non-myelinated nerve fibers and Schwann cells of rat sciatic nerves had reduced compared to rats without epalrestat administuation. Western blot assay and immunohistochemical results demonstrated that after intervention with epalrestat, the activities of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase gradually increased, but aldose reductase protein expression gradually diminished. Results confirmed that epalrestat could protect against diabetic peripheral neuropathy by relieving oxidative stress and suppressing the polyol pathway. PMID:27073391

  18. Autophagy protects intestinal epithelial cells against deoxynivalenol toxicity by alleviating oxidative stress via IKK signaling pathway.

    PubMed

    Tang, Yulong; Li, Jianjun; Li, Fengna; Hu, Chien-An A; Liao, Peng; Tan, Kunrong; Tan, Bie; Xiong, Xia; Liu, Gang; Li, Tiejun; Yin, Yulong

    2015-12-01

    Autophagy is an intracellular process of homeostatic degradation that promotes cell survival under various stressors. Deoxynivalenol (DON), a fungal toxin, often causes diarrhea and disturbs the homeostasis of the intestinal system. To investigate the function of intestinal autophagy in response to DON and associated mechanisms, we firstly knocked out ATG5 (autophagy-related gene 5) in porcine intestinal epithelial cells (IPEC-J2) using CRISPR-Cas9 technology. When treated with DON, autophagy was induced in IPEC-J2 cells but not in IPEC-J2.Atg5ko cells. The deficiency in autophagy increased DON-induced apoptosis in IPEC-J2.atg5ko cells, in part, through the generation of reactive oxygen species (ROS). The cellular stress response can be restored in IPEC-J2.atg5ko cells by overexpressing proteins involved in protein folding. Interestingly, we found that autophagy deficiency downregulated the expression of endoplasmic reticulum folding proteins BiP and PDI when IPEC-J2.atg5ko cells were treated with DON. In addition, we investigated the molecular mechanism of autophagy involved in the IKK, AMPK, and mTOR signaling pathway and found that Bay-117082 and Compound C, specific inhibitors for IKK and AMPK, respectively, inhibited the induction of autophagy. Taken together, our results suggest that autophagy is pivotal for protection against DON in pig intestinal cells.

  19. Recombinant Newcastle disease virus (rL-RVG) triggers autophagy and apoptosis in gastric carcinoma cells by inducing ER stress

    PubMed Central

    Bu, Xuefeng; Zhao, Yinghai; Zhang, Zhijian; Wang, Mubin; Li, Mi; Yan, Yulan

    2016-01-01

    We have reported that the recombinant avirulent Newcastle disease virus (NDV) LaSota strain expressing the rabies virus glycoprotein (rL-RVG) could induce autophagy and apoptosis in gastric carcinoma cells. In the present study, we explored the upstream regulators, endoplasmic reticulum (ER) stress that induce autophagy and apoptosis and the relationships among them. For this purpose, SGC-7901 and HGC cells were infected with rL-RVG. NDV LaSota strain and phosphate-buffered saline (PBS) were treated as the control groups. Western blotting and immunofluorescence microscopy were used to detect the expression of the ER stress-related proteins glucose-regulated protein 78 (GRP78) and the transcription factor GADD153 (CHOP), among others. The expression of beclin-1 and the conversion of light chain (LC) 3-I were used to determine the occurrence of autophagy, and flow cytometry (FCM) and western blotting were used to examine apoptosis-related protein expression. Transmission electron microscopy was also performed to monitor the ultrastructure of the cells. Moreover, small interfering (si) RNA was used to knock down CHOP expression. rL-RVG treatment increased the expression of ER stress-related proteins, such as GRP78, CHOP, activating transcriptional factor 6 (ATF6), X-box-binding protein 1 (XBP-1), and phosphorylated eukaryotic initiation factor 2 (p-eIF2α), in a time- and concentration-dependent manner, and knockdown of CHOP reduced LC3-II conversion and beclin-1 expression. When ER stress was inhibited with 4-PBA, the expression of both autophagy-related proteins and apoptosis-related proteins markedly decreased. Interestingly, inhibition of autophagy with 3-methyladenine (3MA) decreased not only apoptosis-related protein expression but also ER stress-related protein expression. Moreover, we found that downregulation of the c-Jun N-terminal kinase (JNK) pathway by SP600125 reduced LC3-II conversion, beclin-1 expression and caspase-3 activation. Collectively, the

  20. Compounds Triggering ER Stress Exert Anti-Melanoma Effects and Overcome BRAF Inhibitor Resistance.

    PubMed

    Cerezo, Michaël; Lehraiki, Abdelali; Millet, Antoine; Rouaud, Florian; Plaisant, Magali; Jaune, Emilie; Botton, Thomas; Ronco, Cyril; Abbe, Patricia; Amdouni, Hella; Passeron, Thierry; Hofman, Veronique; Mograbi, Baharia; Dabert-Gay, Anne-Sophie; Debayle, Delphine; Alcor, Damien; Rabhi, Nabil; Annicotte, Jean-Sébastien; Héliot, Laurent; Gonzalez-Pisfil, Mariano; Robert, Caroline; Moréra, Solange; Virougoux, Armelle; Gual, Philippe; Ali, Maruf M U; Bertolotto, Corine; Hofman, Paul; Ballotti, Robert; Benhida, Rachid; Rocchi, Stéphane

    2016-06-13

    We have discovered and developed a series of molecules (thiazole benzenesulfonamides). HA15, the lead compound of this series, displayed anti-cancerous activity on all melanoma cells tested, including cells isolated from patients and cells that developed resistance to BRAF inhibitors. Our molecule displayed activity against other liquid and solid tumors. HA15 also exhibited strong efficacy in xenograft mouse models with melanoma cells either sensitive or resistant to BRAF inhibitors. Transcriptomic, proteomic, and biochemical studies identified the chaperone BiP/GRP78/HSPA5 as the specific target of HA15 and demonstrated that the interaction increases ER stress, leading to melanoma cell death by concomitant induction of autophagic and apoptotic mechanisms.

  1. TUSC3 Loss Alters the ER Stress Response and Accelerates Prostate Cancer Growth in vivo

    NASA Astrophysics Data System (ADS)

    Horak, Peter; Tomasich, Erwin; Vaňhara, Petr; Kratochvílová, Kateřina; Anees, Mariam; Marhold, Maximilian; Lemberger, Christof E.; Gerschpacher, Marion; Horvat, Reinhard; Sibilia, Maria; Pils, Dietmar; Krainer, Michael

    2014-01-01

    Prostate cancer is the most prevalent cancer in males in developed countries. Tumor suppressor candidate 3 (TUSC3) has been identified as a putative tumor suppressor gene in prostate cancer, though its function has not been characterized. TUSC3 shares homologies with the yeast oligosaccharyltransferase (OST) complex subunit Ost3p, suggesting a role in protein glycosylation. We provide evidence that TUSC3 is part of the OST complex and affects N-linked glycosylation in mammalian cells. Loss of TUSC3 expression in DU145 and PC3 prostate cancer cell lines leads to increased proliferation, migration and invasion as well as accelerated xenograft growth in a PTEN negative background. TUSC3 downregulation also affects endoplasmic reticulum (ER) structure and stress response, which results in increased Akt signaling. Together, our findings provide first mechanistic insight in TUSC3 function in prostate carcinogenesis in general and N-glycosylation in particular.

  2. Compounds Triggering ER Stress Exert Anti-Melanoma Effects and Overcome BRAF Inhibitor Resistance.

    PubMed

    Cerezo, Michaël; Lehraiki, Abdelali; Millet, Antoine; Rouaud, Florian; Plaisant, Magali; Jaune, Emilie; Botton, Thomas; Ronco, Cyril; Abbe, Patricia; Amdouni, Hella; Passeron, Thierry; Hofman, Veronique; Mograbi, Baharia; Dabert-Gay, Anne-Sophie; Debayle, Delphine; Alcor, Damien; Rabhi, Nabil; Annicotte, Jean-Sébastien; Héliot, Laurent; Gonzalez-Pisfil, Mariano; Robert, Caroline; Moréra, Solange; Virougoux, Armelle; Gual, Philippe; Ali, Maruf M U; Bertolotto, Corine; Hofman, Paul; Ballotti, Robert; Benhida, Rachid; Rocchi, Stéphane

    2016-06-13

    We have discovered and developed a series of molecules (thiazole benzenesulfonamides). HA15, the lead compound of this series, displayed anti-cancerous activity on all melanoma cells tested, including cells isolated from patients and cells that developed resistance to BRAF inhibitors. Our molecule displayed activity against other liquid and solid tumors. HA15 also exhibited strong efficacy in xenograft mouse models with melanoma cells either sensitive or resistant to BRAF inhibitors. Transcriptomic, proteomic, and biochemical studies identified the chaperone BiP/GRP78/HSPA5 as the specific target of HA15 and demonstrated that the interaction increases ER stress, leading to melanoma cell death by concomitant induction of autophagic and apoptotic mechanisms. PMID:27238082

  3. Oxidative Stress Alleviation by Sage Essential Oil in Co-amoxiclav induced Hepatotoxicity in Rats.

    PubMed

    El-Hosseiny, L S; Alqurashy, N N; Sheweita, S A

    2016-06-01

    Clinical studies have shown that several classes of antibiotics are evidenced in drug induced liver injury. The combination of amoxicillin with clavulanic acid is commonly cited in such cases. Accordingly, the present study investigated the potential hepatoprotective and in vivo antioxidant efficacy of sage essential oil in Co-amoxiclav induced hepatotoxicity in rats. Sage essential oil was hydrodistilled from the aerial parts of Salvia officinalis L. and its compositional analysis was characterized by Gas chromatography-Mass spectroscopy. Rats were treated singly or concomitantly with Co-amoxiclav and sage essential oil for a period of seven days. The major components of sage oil as identified by GC-MS were 1,8-cineole, β-pinene, camphor, β-caryophyllene, α-pinene and α-caryophyllene comprising 26.3%, 14.4%, 10.9%, 7.8%, 6% and 2.5% respectively. The in vivo exposure of rats to Co-amoxiclav resulted in hepatotoxicity biochemically evidenced by the significant elevation of serum AST, ALT, ALP, γ-GT, total bilirubin and histologically conveyed by hydropic, inflammatory and cholestatic changes in rats' liver. Oxidative stress mediated the hepatic injury as indicated by the significant escalation in lipid peroxidation, as well as, the significant depletion of both glutathione level and glutathione dependent enzymes' activities. The concomitant administration of sage essential oil with Co-amoxiclav exerted a hepatoprotective effect via inducing an in vivo antioxidant defense response eventually regressing, to some extent, the hepatoarchitectural changes induced by Co-amoxiclav. Results suggest that sage essential oil is a potential candidate for counteracting hepatic injury associating Co-amoxiclav and this effect is in part related to the complexity of its chemical composition. PMID:27493593

  4. Oxidative Stress Alleviation by Sage Essential Oil in Co-amoxiclav induced Hepatotoxicity in Rats

    PubMed Central

    El-Hosseiny, L. S.; Alqurashy, N. N.; Sheweita, S. A.

    2016-01-01

    Clinical studies have shown that several classes of antibiotics are evidenced in drug induced liver injury. The combination of amoxicillin with clavulanic acid is commonly cited in such cases. Accordingly, the present study investigated the potential hepatoprotective and in vivo antioxidant efficacy of sage essential oil in Co-amoxiclav induced hepatotoxicity in rats. Sage essential oil was hydrodistilled from the aerial parts of Salvia officinalis L. and its compositional analysis was characterized by Gas chromatography-Mass spectroscopy. Rats were treated singly or concomitantly with Co-amoxiclav and sage essential oil for a period of seven days. The major components of sage oil as identified by GC-MS were 1,8-cineole, β-pinene, camphor, β-caryophyllene, α-pinene and α-caryophyllene comprising 26.3%, 14.4%, 10.9%, 7.8%, 6% and 2.5% respectively. The in vivo exposure of rats to Co-amoxiclav resulted in hepatotoxicity biochemically evidenced by the significant elevation of serum AST, ALT, ALP, γ-GT, total bilirubin and histologically conveyed by hydropic, inflammatory and cholestatic changes in rats’ liver. Oxidative stress mediated the hepatic injury as indicated by the significant escalation in lipid peroxidation, as well as, the significant depletion of both glutathione level and glutathione dependent enzymes’ activities. The concomitant administration of sage essential oil with Co-amoxiclav exerted a hepatoprotective effect via inducing an in vivo antioxidant defense response eventually regressing, to some extent, the hepatoarchitectural changes induced by Co-amoxiclav. Results suggest that sage essential oil is a potential candidate for counteracting hepatic injury associating Co-amoxiclav and this effect is in part related to the complexity of its chemical composition. PMID:27493593

  5. Oxidative Stress Alleviation by Sage Essential Oil in Co-amoxiclav induced Hepatotoxicity in Rats.

    PubMed

    El-Hosseiny, L S; Alqurashy, N N; Sheweita, S A

    2016-06-01

    Clinical studies have shown that several classes of antibiotics are evidenced in drug induced liver injury. The combination of amoxicillin with clavulanic acid is commonly cited in such cases. Accordingly, the present study investigated the potential hepatoprotective and in vivo antioxidant efficacy of sage essential oil in Co-amoxiclav induced hepatotoxicity in rats. Sage essential oil was hydrodistilled from the aerial parts of Salvia officinalis L. and its compositional analysis was characterized by Gas chromatography-Mass spectroscopy. Rats were treated singly or concomitantly with Co-amoxiclav and sage essential oil for a period of seven days. The major components of sage oil as identified by GC-MS were 1,8-cineole, β-pinene, camphor, β-caryophyllene, α-pinene and α-caryophyllene comprising 26.3%, 14.4%, 10.9%, 7.8%, 6% and 2.5% respectively. The in vivo exposure of rats to Co-amoxiclav resulted in hepatotoxicity biochemically evidenced by the significant elevation of serum AST, ALT, ALP, γ-GT, total bilirubin and histologically conveyed by hydropic, inflammatory and cholestatic changes in rats' liver. Oxidative stress mediated the hepatic injury as indicated by the significant escalation in lipid peroxidation, as well as, the significant depletion of both glutathione level and glutathione dependent enzymes' activities. The concomitant administration of sage essential oil with Co-amoxiclav exerted a hepatoprotective effect via inducing an in vivo antioxidant defense response eventually regressing, to some extent, the hepatoarchitectural changes induced by Co-amoxiclav. Results suggest that sage essential oil is a potential candidate for counteracting hepatic injury associating Co-amoxiclav and this effect is in part related to the complexity of its chemical composition.

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

    PubMed

    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.

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

    PubMed

    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

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

    PubMed Central

    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

  9. Involvement of mitochondrial dysfunction and ER-stress in the physiopathology of equine osteochondritis dissecans (OCD).

    PubMed

    Desjardin, Clémence; Chat, Sophie; Gilles, Mailys; Legendre, Rachel; Riviere, Julie; Mata, Xavier; Balliau, Thierry; Esquerré, Diane; Cribiu, Edmond P; Betch, Jean-Marc; Schibler, Laurent

    2014-06-01

    Osteochondrosis (OC) is a developmental bone disorder affecting several mammalian species including the horse. Equine OC is described as a focal disruption of endochondral ossification, leading to osteochondral lesions (osteochondritis dissecans, OCD) that may release free bodies within the joint. OCD lesions trigger joint swelling, stiffness and lameness and affects about 30% of the equine population. OCD is considered as multifactorial but its physiopathology is still poorly understood and genes involved in genetic predisposition are still unknown. Our study compared two healthy and two OC-affected 18-month-old French Trotters diagnosed with OCD lesions at the intermediate ridge of the distal tibia. A comparative shot-gun proteomic analysis of non-wounded cartilage and sub-chondral bone from healthy (healthy samples) and OC-affected foals (predisposed samples) identified 83 and 53 modulated proteins, respectively. These proteins are involved in various biological pathways including matrix structure and maintenance, protein biosynthesis, folding and transport, mitochondrial activity, energy and calcium metabolism. Transmission electron microscopy revealed typical features of mitochondrial swelling and ER-stress, such as large, empty mitochondria, and hyper-dilated rough endoplasmic reticulum, in the deep zone of both OC lesions and predisposed cartilage. Abnormal fibril organization surrounding chondrocytes and abnormal features at the ossification front were also observed. Combining these findings with quantitative trait loci and whole genome sequencing results identified about 140 functional candidate genes carrying putative damaging mutations in 30 QTL regions. In summary, our study suggests that OCD lesions may result from defective hypertrophic terminal differentiation associated with mitochondrial dysfunction and ER-stress, leading to impaired cartilage and bone biomechanical properties, making them prone to fractures. In addition, 11 modulated proteins and

  10. Translational and posttranslational regulation of XIAP by eIF2α and ATF4 promotes ER stress-induced cell death during the unfolded protein response.

    PubMed

    Hiramatsu, Nobuhiko; Messah, Carissa; Han, Jaeseok; LaVail, Matthew M; Kaufman, Randal J; Lin, Jonathan H

    2014-05-01

    Endoplasmic reticulum (ER) protein misfolding activates the unfolded protein response (UPR) to help cells cope with ER stress. If ER homeostasis is not restored, UPR promotes cell death. The mechanisms of UPR-mediated cell death are poorly understood. The PKR-like endoplasmic reticulum kinase (PERK) arm of the UPR is implicated in ER stress-induced cell death, in part through up-regulation of proapoptotic CCAAT/enhancer binding protein homologous protein (CHOP). Chop((-)/(-)) cells are partially resistant to ER stress-induced cell death, and CHOP overexpression alone does not induce cell death. These findings suggest that additional mechanisms regulate cell death downstream of PERK. Here we find dramatic suppression of antiapoptosis XIAP proteins in response to chronic ER stress. We find that PERK down-regulates XIAP synthesis through eIF2α and promotes XIAP degradation through ATF4. Of interest, PERK's down-regulation of XIAP occurs independently of CHOP activity. Loss of XIAP leads to increased cell death, whereas XIAP overexpression significantly enhances resistance to ER stress-induced cell death, even in the absence of CHOP. Our findings define a novel signaling circuit between PERK and XIAP that operates in parallel with PERK to CHOP induction to influence cell survival during ER stress. We propose a "two-hit" model of ER stress-induced cell death involving concomitant CHOP up-regulation and XIAP down-regulation both induced by PERK.

  11. Trichosanthes dioica fruit ameliorates experimentally induced arsenic toxicity in male albino rats through the alleviation of oxidative stress.

    PubMed

    Bhattacharya, Sanjib; Haldar, Pallab Kanti

    2012-08-01

    The present work was focused to evaluate the ameliorative property of aqueous extract of Trichosanthes dioica fruit (AQ T. dioica fruit) against arsenic-induced toxicity in male Wistar albino rats. AQ T. dioica fruit was administered orally to rats at 50 and 100 mg/kg body weight for 20 consecutive days prior to oral administration of sodium arsenite (10 mg/kg) for 10 days. Then the rats were sacrificed for the evaluation of body weights, organ weights, hematological profile, serum biochemical profile, and hepatic and renal antioxidative parameters viz. lipid peroxidation, reduced and oxidized glutathione, glutathione-S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, and DNA fragmentation. Pretreatment with AQ T. dioica fruit at both doses markedly and significantly normalized body weights, organ weights, hematological profiles, and serum biochemical profile in arsenic-treated animals. Further, AQ T. dioica fruit pretreatment significantly modulated all the aforesaid hepatic and renal biochemical perturbations and reduced DNA fragmentation in arsenic-intoxicated rats. Therefore, from the present findings, it can be concluded that T. dioica fruit possessed remarkable value in amelioration of arsenic-induced hepatic and renal toxicity, mediated by alleviation of arsenic-induced oxidative stress by multiple mechanisms in male albino rats.

  12. Treadmill exercise alleviates post-traumatic stress disorder-induced impairment of spatial learning memory in rats.

    PubMed

    Kim, Bo-Kyun; Seo, Jin-Hee

    2013-01-01

    Post-traumatic stress disorder (PTSD) is a condition which occurs after a person has experienced unusual stress. The neurons in the hippocampus are especially vulnerable to the PTSD. In the present study, the effect of treadmill exercise on spatial learning memory and cell proliferation in the hippocampus of rats with PTSD. Radial 8-arm maze test and immunohistochemistr for 5-bromo-2'-deoxyridine (BrdU) and double-cortin (DCX) were conducted for this experiment. For the inducing PTSD, the rats were exposure to 0.2 mA electric foot shock for 7 consecutive days. Electric foot shock continued 6 seconds, repeated 10 times with a 30 sec interval per one trial, and repeated 3 trials per day. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks, stating one day after finishing last electric food shock. Presently, the PTSD rats showed longer time of successful performance, higher error number, and lower correct number in the radial-8-arm maze test. Cell proliferation and DCX expression in the hippocampal dentate gyrus were suppressed in the PTSD rats. In contrast, treadmill exercise alleviated PTSD-induced impairment of spatial learning memory. The rats performed treadmill exercise showed longer time of successful performance, higher error number, and lower correct number in the radial-8-arm maze test. Treadmill exercise also enhanced cell proliferation and DCX expression in the hippocampal dentate gyrus of PTSD rats. The present study demonstrated that treadmill exercise ameliorated PTSD-induced memory impairment through enhancing cell proliferation in the hippocampus.

  13. Bcl-2 antagonists interact synergistically with bortezomib in DLBCL cells in association with JNK activation and induction of ER stress.

    PubMed

    Dasmahapatra, Girija; Lembersky, Dmitry; Rahmani, Mohamed; Kramer, Lora; Friedberg, Jonathan; Fisher, Richard I; Dent, Paul; Grant, Steven

    2009-05-01

    Mechanisms underlying interactions between the proteasome inhibitor bortezomib and small molecule Bcl-2 antagonists were examined in GC- and ABC-type human DLBCL (diffuse lymphocytic B-cell lymphoma) cells. Concomitant or sequential exposure to non- or minimally toxic concentrations of bortezomib or other proteasome inhibitors and either HA14-1 or gossypol resulted in a striking increase in Bax/Bak conformational change/translocation, cytochrome c release, caspase activation and synergistic induction of apoptosis in both GC- and ABC-type cells. These events were associated with a sharp increase in activation of the stress kinase JNK and evidence of ER stress induction (e.g., eIF2alpha phosphorylation, activation of caspases-2 and -4, and Grp78 upregulation). Pharmacologic or genetic (e.g., shRNA knockdown) interruption of JNK signaling attenuated HA14-1/bortezomib lethality and ER stress induction. Genetic disruption of the ER stress pathway (e.g., in cells expressing caspase-4 shRNA or DN-eIF2alpha) significantly attenuated lethality. The toxicity of this regimen was independent of ROS generation. Finally, HA14-1 significantly increased bortezomib-mediated JNK activation, ER stress induction, and lethality in bortezomib-resistant cells. Collectively these findings indicate that small molecule Bcl-2 antagonists promote bortezomib-mediated mitochondrial injury and lethality in DLBCL cells in association with enhanced JNK activation and ER stress induction. They also raise the possibility that such a strategy may be effective in different DLBCL sub-types (e.g., GC- or ABC), and in bortezomib-resistant disease. PMID:19270531

  14. Bcl-2 antagonists interact synergistically with bortezomib in DLBCL cells in association with JNK activation and induction of ER stress

    PubMed Central

    Dasmahapatra, Girija; Lembersky, Dmitry; Rahmani, Mohamed; Kramer, Lora; Friedberg, Jonathan; Fisher, Richard I.; Dent, Paul; Grant, Steven

    2010-01-01

    Mechanisms underlying interactions between the proteasome inhibitor bortezomib and small molecule Bcl-2 antagonists were examined in GC- and ABC-type human DLBCL (diffuse lymphocytic B-cell lymphoma) cells. Concomitant or sequential exposure to non- or minimally toxic concentrations of bortezomib or other proteasome inhibitors and either HA14-1 or gossypol resulted in a striking increase in Bax/Bak conformational change/translocation, cytochrome c release, caspase activation and synergistic induction of apoptosis in both GC- and ABC-type cells. These events were associated with a sharp increase in activation of the stress kinase JNK and evidence of ER stress induction (e.g., eIF2α phosphorylation, activation of caspases-2 and -4, and Grp78 upregulation). Pharmacologic or genetic (e.g., shRNA knockdown) interruption of JNK signaling attenuated HA14-1/bortezomib lethality and ER stress induction. Genetic disruption of the ER stress pathway (e.g., in cells expressing caspase-4 shRNA or DN-eIF2α) significantly attenuated lethality. The toxicity of this regimen was independent of ROS generation. Finally, HA14-1 significantly increased bortezomib-mediated JNK activation, ER stress induction, and lethality in bortezomib-resistant cells. Collectively these findings indicate that small molecule Bcl-2 antagonists promote bortezomib-mediated mitochondrial injury and lethality in DLBCL cells in association with enhanced JNK activation and ER stress induction. They also raise the possibility that such a strategy may be effective in different DLBCL sub-types (e.g., GC- or ABC), and in bortezomib-resistant disease. PMID:19270531

  15. Tyrosol, an olive oil polyphenol, inhibits ER stress-induced apoptosis in pancreatic β-cell through JNK signaling.

    PubMed

    Lee, Hyunjung; Im, Sung Won; Jung, Chang Hwa; Jang, Young Jin; Ha, Tae Youl; Ahn, Jiyun

    2016-01-15

    Dysfunction of pancreatic β-cell is a major determinant for the development of type 2 diabetes. Because of the stimulated insulin secretion in metabolic syndrome, endoplasmic reticulum (ER) stress plays a central mediator for β-cell failure. In this study, we investigated whether an antioxidant phenolic compound, tyrosol protects against β-cell dysfunction associated with ER stress. To address this issue, we exposed pancreatic β cells, NIT-1 to tunicamycin with tyrosol. We found tyrosol diminished tunicamycin-induced cell death in a dose-dependent manner. We also detected tyrosol decreased the expressions of apoptosis-related markers. Exposure to tunicamycin evoked UPR response and co-treatment of tyrosol led to reduction of ER stress. These effects of tyrosol were mediated by the phosphorylation of JNK. Moreover, we confirmed supplement of tyrosol ameliorated β-cell loss induced by high fat feeding. Taken together, our study provides a molecular basis for signaling transduction of protective effect of tyrosol against ER stress-induced β-cell death. Therefore, we suggest tyrosol could be a potential therapeutic candidate for amelioration of type 2 diabetes. PMID:26692476

  16. Meloxicam combined with sorafenib synergistically inhibits tumor growth of human hepatocellular carcinoma cells via ER stress-related apoptosis.

    PubMed

    Zhong, Jingtao; Xiu, Peng; Dong, Xiaofeng; Wang, Fuhai; Wei, Honglong; Wang, Xin; Xu, Zongzhen; Liu, Feng; Li, Tao; Wang, Yong; Li, Jie

    2015-10-01

    Sorafenib (SOR) is a promising treatment for advanced hepatocellular carcinoma (HCC). However, the precise mechanisms of toxicity and drug resistance have not been fully explored and new strategies are urgently needed for HCC therapy. Meloxicam (MEL) is a selective cyclooxygenase-2 (COX-2) inhibitor which elicits antitumor effects in human HCC cells. In the present study, we investigated the interaction between MEL and SOR in human SMMC‑7721 cells and the role endoplasmic reticulum (ER) stress exerts in the combination of SOR with MEL treatment-induced cytotoxicity. Our results revealed that the combination treatment synergistically inhibited cell proliferation and enhanced apoptosis. Furthermore, the combination treatment enhanced ER stress-related molecules which involved in SMMC-7721 cell apoptosis. GRP78 knockdown by siRNA or co-treatment with MG132 significantly increased this combination treatment-induced apoptosis. In addition, we found that the combination treatment suppressed tumor growth by way of activation of ER stress in in vivo models. We concluded that the combination of SOR with MEL treatment-induced ER stress, and eventually apoptosis in human SMMC-7721 cells. Knockdown of GRP78 using siRNA or proteosome inhibitor enhanced the cytotoxicity of the combination of SOR with MEL-treatment in SMMC-7721 cells. These findings provided a new potential treatment strategy against HCC.

  17. Smyd1 Facilitates Heart Development by Antagonizing Oxidative and ER Stress Responses

    PubMed Central

    Park, Chong Yon; Harriss, June; Pierce, Stephanie A.; Dekker, Joseph D.; Valenzuela, Nicolas; Srivastava, Deepak; Schwartz, Robert J.; Stewart, M. David; Tucker, Haley O.

    2015-01-01

    Smyd1/Bop is an evolutionary conserved histone methyltransferase previously shown by conventional knockout to be critical for embryonic heart development. To further explore the mechanism(s) in a cell autonomous context, we conditionally ablated Smyd1 in the first and second heart fields of mice using a knock-in (KI) Nkx2.5-cre driver. Robust deletion of floxed-Smyd1 in cardiomyocytes and the outflow tract (OFT) resulted in embryonic lethality at E9.5, truncation of the OFT and right ventricle, and additional defects consistent with impaired expansion and proliferation of the second heart field (SHF). Using a transgenic (Tg) Nkx2.5-cre driver previously shown to not delete in the SHF and OFT, early embryonic lethality was bypassed and both ventricular chambers were formed; however, reduced cardiomyocyte proliferation and other heart defects resulted in later embryonic death at E11.5-12.5. Proliferative impairment prior to both early and mid-gestational lethality was accompanied by dysregulation of transcripts critical for endoplasmic reticulum (ER) stress. Mid-gestational death was also associated with impairment of oxidative stress defense—a phenotype highly similar to the previously characterized knockout of the Smyd1-interacting transcription factor, skNAC. We describe a potential feedback mechanism in which the stress response factor Tribbles3/TRB3, when directly methylated by Smyd1, acts as a co-repressor of Smyd1-mediated transcription. Our findings suggest that Smyd1 is required for maintaining cardiomyocyte proliferation at minimally two different embryonic heart developmental stages, and its loss leads to linked stress responses that signal ensuing lethality. PMID:25803368

  18. Pentoxifylline triggers autophagy via ER stress response that interferes with Pentoxifylline induced apoptosis in human melanoma cells.

    PubMed

    Sharma, Kapil; Ishaq, Mohammad; Sharma, Gaurav; Khan, Mohammad Aslam; Dutta, Rajesh Kumar; Majumdar, Sekhar

    2016-03-01

    Pentoxifylline (PTX), a non-specific phosphodiesterase inhibitor is known to inhibit the growth of various cancer cells including melanoma. Here in this study, we have found that PTX induces autophagy in human melanoma cell lines (A375 and MeWo). Induction of autophagy is associated with the increase in Atg5 expression as knockdown of Atg5 effectively inhibited PTX mediated autophagy. A decrease in mTOR activation was also observed after PTX treatment. We observed that autophagy was activated as a downstream effector mechanism of ER stress induced by PTX. ER stress response was confirmed by upregulation of IRE-1α, GRP78 and CHOP expression. PTX treatment also resulted in an increase in intracellular calcium (Ca(2+)) level. Ca(2+) is the central player as blocking Ca(2+) by intracellular calcium chelator (BAPTA-AM) effectively inhibited the PTX induced ER stress response as well as autophagy. Moreover, silencing of CHOP also resulted in autophagy inhibition with a decrease in Atg5 expression. Collectively, PTX triggers ER stress response followed by induction of autophagy via involvement of Ca(2+)→CHOP→Atg5 signalling cascade. Interestingly, inhibition of intracellular calcium level by BAPTA-AM significantly increased PTX mediated cell death by augmenting intrinsic apoptotic pathway. Inhibition of autophagy by the ATG5 siRNA and pharmacological inhibitor, chloroquine also enhances PTX induced cell death. Taken together, our results clearly indicate that activation of ER stress response and autophagy provides resistance to PTX mediated apoptosis, and thus, interferes with the anticancer activity of PTX in human melanoma cells.

  19. Pentoxifylline triggers autophagy via ER stress response that interferes with Pentoxifylline induced apoptosis in human melanoma cells.

    PubMed

    Sharma, Kapil; Ishaq, Mohammad; Sharma, Gaurav; Khan, Mohammad Aslam; Dutta, Rajesh Kumar; Majumdar, Sekhar

    2016-03-01

    Pentoxifylline (PTX), a non-specific phosphodiesterase inhibitor is known to inhibit the growth of various cancer cells including melanoma. Here in this study, we have found that PTX induces autophagy in human melanoma cell lines (A375 and MeWo). Induction of autophagy is associated with the increase in Atg5 expression as knockdown of Atg5 effectively inhibited PTX mediated autophagy. A decrease in mTOR activation was also observed after PTX treatment. We observed that autophagy was activated as a downstream effector mechanism of ER stress induced by PTX. ER stress response was confirmed by upregulation of IRE-1α, GRP78 and CHOP expression. PTX treatment also resulted in an increase in intracellular calcium (Ca(2+)) level. Ca(2+) is the central player as blocking Ca(2+) by intracellular calcium chelator (BAPTA-AM) effectively inhibited the PTX induced ER stress response as well as autophagy. Moreover, silencing of CHOP also resulted in autophagy inhibition with a decrease in Atg5 expression. Collectively, PTX triggers ER stress response followed by induction of autophagy via involvement of Ca(2+)→CHOP→Atg5 signalling cascade. Interestingly, inhibition of intracellular calcium level by BAPTA-AM significantly increased PTX mediated cell death by augmenting intrinsic apoptotic pathway. Inhibition of autophagy by the ATG5 siRNA and pharmacological inhibitor, chloroquine also enhances PTX induced cell death. Taken together, our results clearly indicate that activation of ER stress response and autophagy provides resistance to PTX mediated apoptosis, and thus, interferes with the anticancer activity of PTX in human melanoma cells. PMID:26793997

  20. Interaction between endoplasmic/sarcoplasmic reticulum stress (ER/SR stress), mitochondrial signaling and Ca(2+) regulation in airway smooth muscle (ASM).

    PubMed

    Delmotte, Philippe; Sieck, Gary C

    2015-02-01

    Airway inflammation is a key aspect of diseases such as asthma. Several inflammatory cytokines (e.g., TNFα and IL-13) increase cytosolic Ca(2+) ([Ca(2+)]cyt) responses to agonist stimulation and Ca(2+) sensitivity of force generation, thereby enhancing airway smooth muscle (ASM) contractility (hyper-reactive state). Inflammation also induces ASM proliferation and remodeling (synthetic state). In normal ASM, the transient elevation of [Ca(2+)]cyt induced by agonists leads to a transient increase in mitochondrial Ca(2+) ([Ca(2+)]mito) that may be important in matching ATP production with ATP consumption. In human ASM (hASM) exposed to TNFα and IL-13, the transient increase in [Ca(2+)]mito is blunted despite enhanced [Ca(2+)]cyt responses. We also found that TNFα and IL-13 induce reactive oxidant species (ROS) formation and endoplasmic/sarcoplasmic reticulum (ER/SR) stress (unfolded protein response) in hASM. ER/SR stress in hASM is associated with disruption of mitochondrial coupling with the ER/SR membrane, which relates to reduced mitofusin 2 (Mfn2) expression. Thus, in hASM it appears that TNFα and IL-13 result in ROS formation leading to ER/SR stress, reduced Mfn2 expression, disruption of mitochondrion-ER/SR coupling, decreased mitochondrial Ca(2+) buffering, mitochondrial fragmentation, and increased cell proliferation.

  1. Early and sustained exposure to high-sucrose diet triggers hippocampal ER stress in young rats.

    PubMed

    Pinto, Bruno Araújo Serra; Melo, Thamys Marinho; Flister, Karla Frida Torres; França, Lucas Martins; Kajihara, Daniela; Tanaka, Leonardo Yuji; Laurindo, Francisco Rafael Martins; Paes, Antonio Marcus de Andrade

    2016-08-01

    Early-life environmental insults have been shown to promote long-term development of chronic non-communicable diseases, including metabolic disturbances and mental illnesses. As such, premature consumption of high-sugar foods has been associated to early onset of detrimental outcomes, whereas underlying mechanisms are still poorly understood. In the present study, we sought to investigate whether early and sustained exposure to high-sucrose diet promotes metabolic disturbances that ultimately might anticipate neurological injuries. At postnatal day 21, weaned male rats started to be fed a standard chow (10 % sucrose, CTR) or a high-sucrose diet (25 % sucrose, HSD) for 9 weeks prior to euthanasia at postnatal day 90. HSD did not alter weight gain and feed efficiency between groups, but increased visceral, non-visceral and brown adipose tissue accumulation. HSD rats demonstrated elevated blood glucose levels in both fasting and fed states, which were associated to impaired glucose tolerance. Peripheral insulin sensitivity did not change, whereas hepatic insulin resistance was supported by increased serum triglyceride levels, as well as higher TyG index values. Assessment of hippocampal gene expression showed endoplasmic reticulum (ER) stress pathways were activated in HSD rats, as compared to CTR. HSD rats had overexpression of unfolded protein response sensors, PERK and ATF6; ER chaperone, PDIA2 and apoptosis-related genes, CHOP and Caspase 3; but decreased expression of chaperone GRP78. Finally, HSD rats demonstrated impaired neuromuscular function and anxious behavior, but preserved cognitive parameters. In conclusion, our data indicate that early exposure to HSD promote metabolic disturbances, which disrupt hippocampus homeostasis and might precociously affect its neurobehavioral functions. PMID:27154727

  2. The PERK pathway independently triggers apoptosis and a Rac1/Slpr/JNK/Dilp8 signaling favoring tissue homeostasis in a chronic ER stress Drosophila model

    PubMed Central

    Demay, Y; Perochon, J; Szuplewski, S; Mignotte, B; Gaumer, S

    2014-01-01

    The endoplasmic reticulum (ER) has a major role in protein folding. The accumulation of unfolded proteins in the ER induces a stress, which can be resolved by the unfolded protein response (UPR). Chronicity of ER stress leads to UPR-induced apoptosis and in turn to an unbalance of tissue homeostasis. Although ER stress-dependent apoptosis is observed in a great number of devastating human diseases, how cells activate apoptosis and promote tissue homeostasis after chronic ER stress remains poorly understood. Here, using the Drosophila wing imaginal disc as a model system, we validated that Presenilin overexpression induces chronic ER stress in vivo. We observed, in this novel model of chronic ER-stress, a PERK/ATF4-dependent apoptosis requiring downregulation of the antiapoptotic diap1 gene. PERK/ATF4 also activated the JNK pathway through Rac1 and Slpr activation in apoptotic cells, leading to the expression of Dilp8. This insulin-like peptide caused a developmental delay, which partially allowed the replacement of apoptotic cells. Thanks to a novel chronic ER stress model, these results establish a new pathway that both participates in tissue homeostasis and triggers apoptosis through an original regulation. PMID:25299777

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

    PubMed

    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. PMID:25957150

  4. Alleviation of salt stress in citrus seedlings inoculated with arbuscular mycorrhizal fungi depends on the rootstock salt tolerance.

    PubMed

    Navarro, Josefa M; Pérez-Tornero, Olaya; Morte, Asunción

    2014-01-01

    Seedlings of Cleopatra mandarin (Citrus reshni Hort. ex Tan.) and Alemow (Citrus macrophylla Wester) were inoculated with a mixture of AM fungi (Rhizophagus irregularis and Funneliformis mosseae) (+AM), or left non-inoculated (-AM). From forty-five days after fungal inoculation onwards, half of +AM or -AM plants were irrigated with nutrient solution containing 50 mM NaCl. Three months later, AM significantly increased plant growth in both Cleopatra mandarin and Alemow rootstocks. Plant growth was higher in salinized +AM plants than in non-salinized -AM plants, demonstrating that AM compensates the growth limitations imposed by salinity. Whereas AM-inoculated Cleopatra mandarin seedlings had a very good response under saline treatment, inoculation in Alemow did not alleviate the negative effect of salinity. The beneficial effect of mycorrhization is unrelated with protection against the uptake of Na or Cl and the effect of AM on these ions did not explain the different response of rootstocks. This response was related with the nutritional status since our findings confirm that AM fungi can alter host responses to salinity stress, improving more the P, K, Fe and Cu plant nutrition in Cleopatra mandarin than in Alemow plants. AM inoculation under saline treatments also increased root Mg concentration but it was higher in Cleopatra mandarin than in Alemow. This could explain why AM fungus did not completely recovered chlorophyll concentrations in Alemow and consequently it had lower photosynthesis rate than control plants. AM fungi play an essential role in citrus rootstock growth and biomass production although the intensity of this response depends on the rootstock salinity tolerance.

  5. Neuronal ER stress impedes myeloid-cell-induced vascular regeneration through IRE1α degradation of netrin-1.

    PubMed

    Binet, François; Mawambo, Gaëlle; Sitaras, Nicholas; Tetreault, Nicolas; Lapalme, Eric; Favret, Sandra; Cerani, Agustin; Leboeuf, Dominique; Tremblay, Sophie; Rezende, Flavio; Juan, Aimee M; Stahl, Andreas; Joyal, Jean-Sebastien; Milot, Eric; Kaufman, Randal J; Guimond, Martin; Kennedy, Timothy E; Sapieha, Przemyslaw

    2013-03-01

    In stroke and proliferative retinopathy, despite hypoxia driven angiogenesis, delayed revascularization of ischemic tissue aggravates the loss of neuronal function. What hinders vascular regrowth in the ischemic central nervous system remains largely unknown. Using the ischemic retina as a model of neurovascular interaction in the CNS, we provide evidence that the failure of reparative angiogenesis is temporally and spatially associated with endoplasmic reticulum (ER) stress. The canonical ER stress pathways of protein kinase RNA-like ER kinase (PERK) and inositol-requiring enzyme-1α (IRE1α) are activated within hypoxic/ischemic retinal ganglion neurons, initiating a cascade that results in angiostatic signals. Our findings demonstrate that the endoribonuclease IRE1α degrades the classical guidance cue netrin-1. This neuron-derived cue triggers a critical reparative-angiogenic switch in neural macrophage/microglial cells. Degradation of netrin-1, by persistent neuronal ER stress, thereby hinders vascular regeneration. These data identify a neuronal-immune mechanism that directly regulates reparative angiogenesis.

  6. Intracellular Ca2+ release through ryanodine receptors contributes to AMPA receptor-mediated mitochondrial dysfunction and ER stress in oligodendrocytes

    PubMed Central

    Ruiz, A; Matute, C; Alberdi, E

    2010-01-01

    Overactivation of ionotropic glutamate receptors in oligodendrocytes induces cytosolic Ca2+ overload and excitotoxic death, a process that contributes to demyelination and multiple sclerosis. Excitotoxic insults cause well-characterized mitochondrial alterations and endoplasmic reticulum (ER) dysfunction, which is not fully understood. In this study, we analyzed the contribution of ER-Ca2+ release through ryanodine receptors (RyRs) and inositol triphosphate receptors (IP3Rs) to excitotoxicity in oligodendrocytes in vitro. First, we observed that oligodendrocytes express all previously characterized RyRs and IP3Rs. Blockade of Ca2+-induced Ca2+ release by TMB-8 following α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor-mediated insults attenuated both oligodendrocyte death and cytosolic Ca2+ overload. In turn, RyR inhibition by ryanodine reduced as well the Ca2+ overload whereas IP3R inhibition was ineffective. Furthermore, AMPA-triggered mitochondrial membrane depolarization, oxidative stress and activation of caspase-3, which in all instances was diminished by RyR inhibition. In addition, we observed that AMPA induced an ER stress response as revealed by α subunit of the eukaryotic initiation factor 2α phosphorylation, overexpression of GRP chaperones and RyR-dependent cleavage of caspase-12. Finally, attenuating ER stress with salubrinal protected oligodendrocytes from AMPA excitotoxicity. Together, these results show that Ca2+ release through RyRs contributes to cytosolic Ca2+ overload, mitochondrial dysfunction, ER stress and cell death following AMPA receptor-mediated excitotoxicity in oligodendrocytes. PMID:21364659

  7. Higher Ammonium Transamination Capacity Can Alleviate Glutamate Inhibition on Winter Wheat (Triticum aestivum L.) Root Growth under High Ammonium Stress.

    PubMed

    Wang, Feng; Gao, Jingwen; Liu, Yang; Tian, Zhongwei; Muhammad, Abid; Zhang, Yixuan; Jiang, Dong; Cao, Weixing; Dai, Tingbo

    2016-01-01

    Most of the studies about NH4+ stress mechanism simply address the effects of free NH4+, failing to recognize the changed nitrogen assimilation products. The objective of this study was to elucidate the effects of glutamate on root growth under high ammonium (NH4+) conditions in winter wheat (Triticum aestivum L.). Hydroponic experiments were conducted using two wheat cultivars, AK58 (NH4+-sensitive) and Xumai25 (NH4+-tolerant) with either 5 mM NH4+ nitrogen (AN) as stress treatment or 5 mM nitrate (NO3-) nitrogen as control. To evaluate the effects of NH4+-assimilation products on plant growth, 1 μM L-methionine sulfoximine (MSO) (an inhibitor of glutamine synthetase (GS)) and 1 mM glutamates (a primary N assimilation product) were added to the solutions, respectively. The AN significantly reduced plant biomass, total root length, surface area and root volume in both cultivars, but less effect was observed in Xumai25. The inhibition effects were alleviated by the application of MSO but strengthened by the application of glutamate. The AN increased the activities of GS, glutamate dehydrogenase (GDH) in both cultivars, resulting in higher glutamate contents. However, its contents were decreased by the application of MSO. Compared to AK58, Xumai25 showed lower glutamate contents due to its higher activities of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT). With the indole-3-acetic acid (IAA) contents decreasing in roots, the ratio of shoot to root in IAA was increased, and further increased by the application of glutamate, and reduced by the application of MSO, but the ratio was lower in Xumai25. Meanwhile, the total soluble sugar contents and its root to shoot ratio also showed similar trends. These results indicate that the NH4+-tolerant cultivar has a greater transamination ability to prevent glutamate over-accumulation to maintain higher IAA transport ability, and consequently promoted soluble sugar transport to roots, further

  8. Higher Ammonium Transamination Capacity Can Alleviate Glutamate Inhibition on Winter Wheat (Triticum aestivum L.) Root Growth under High Ammonium Stress

    PubMed Central

    Liu, Yang; Tian, Zhongwei; Muhammad, Abid; Zhang, Yixuan; Jiang, Dong; Cao, Weixing; Dai, Tingbo

    2016-01-01

    Most of the studies about NH4+ stress mechanism simply address the effects of free NH4+, failing to recognize the changed nitrogen assimilation products. The objective of this study was to elucidate the effects of glutamate on root growth under high ammonium (NH4+) conditions in winter wheat (Triticum aestivum L.). Hydroponic experiments were conducted using two wheat cultivars, AK58 (NH4+-sensitive) and Xumai25 (NH4+-tolerant) with either 5 mM NH4+ nitrogen (AN) as stress treatment or 5 mM nitrate (NO3-) nitrogen as control. To evaluate the effects of NH4+-assimilation products on plant growth, 1 μM L-methionine sulfoximine (MSO) (an inhibitor of glutamine synthetase (GS)) and 1 mM glutamates (a primary N assimilation product) were added to the solutions, respectively. The AN significantly reduced plant biomass, total root length, surface area and root volume in both cultivars, but less effect was observed in Xumai25. The inhibition effects were alleviated by the application of MSO but strengthened by the application of glutamate. The AN increased the activities of GS, glutamate dehydrogenase (GDH) in both cultivars, resulting in higher glutamate contents. However, its contents were decreased by the application of MSO. Compared to AK58, Xumai25 showed lower glutamate contents due to its higher activities of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT). With the indole-3-acetic acid (IAA) contents decreasing in roots, the ratio of shoot to root in IAA was increased, and further increased by the application of glutamate, and reduced by the application of MSO, but the ratio was lower in Xumai25. Meanwhile, the total soluble sugar contents and its root to shoot ratio also showed similar trends. These results indicate that the NH4+-tolerant cultivar has a greater transamination ability to prevent glutamate over-accumulation to maintain higher IAA transport ability, and consequently promoted soluble sugar transport to roots, further

  9. IRS1 deficiency protects β-cells against ER stress-induced apoptosis by modulating sXBP-1 stability and protein translation

    PubMed Central

    Takatani, Tomozumi; Shirakawa, Jun; Roe, Michael W.; Leech, Colin A.; Maier, Bernhard F.; Mirmira, Raghavendra G.; Kulkarni, Rohit N.

    2016-01-01

    Endoplasmic reticulum (ER) stress is among several pathological features that underlie β-cell failure in the development of type 1 and type 2 diabetes. Adaptor proteins in the insulin/insulin-like-growth factor-1 signaling pathways, such as insulin receptor substrate-1 (IRS1) and IRS2, differentially impact β-cell survival but the underlying mechanisms remain unclear. Here we report that β-cells deficient in IRS1 (IRS1KO) are resistant, while IRS2 deficiency (IRS2KO) makes them susceptible to ER stress-mediated apoptosis. IRS1KOs exhibited low nuclear accumulation of spliced XBP-1 due to its poor stability, in contrast to elevated accumulation in IRS2KO. The reduced nuclear accumulation in IRS1KO was due to protein instability of Xbp1 secondary to proteasomal degradation. IRS1KO also demonstrated an attenuation in their general translation status in response to ER stress revealed by polyribosomal profiling. Phosphorylation of eEF2 was dramatically increased in IRS1KO enabling the β-cells to adapt to ER stress by blocking translation. Furthermore, significantly high ER calcium (Ca2+) was detected in IRS1KO β-cells even upon induction of ER stress. These observations suggest that IRS1 could be a therapeutic target for β-cell protection against ER stress-mediated cell death by modulating XBP-1 stability, protein synthesis, and Ca2+ storage in the ER. PMID:27378176

  10. Ethanol promotes saturated fatty acid-induced hepatoxicity through endoplasmic reticulum (ER) stress response.

    PubMed

    Yi, Hong-Wei; Ma, Yu-Xiang; Wang, Xiao-Ning; Wang, Cui-Fen; Lu, Jian; Cao, Wei; Wu, Xu-Dong

    2015-04-01

    Serum palmitic acid (PA), a type of saturated fatty acid, causes lipid accumulation and induces toxicity in hepatocytes. Ethanol (EtOH) is metabolized by the liver and induces hepatic injury and inflammation. Herein, we analyzed the effects of EtOH on PA-induced lipotoxicity in the liver. Our results indicated that EtOH aggravated PA-induced apoptosis and lipid accumulation in primary rat hepatocytes in dose-dependent manner. EtOH intensified PA-caused endoplasmic reticulum (ER) stress response in vitro and in vivo, and the expressions of CHOP, ATF4, and XBP-1 in nucleus were significantly increased. EtOH also increased PA-caused cleaved caspase-3 in cytoplasm. In wild type and CHOP(-/-) mice treated with EtOH and high fat diet (HFD), EtOH worsened the HFD-induced liver injury and dyslipidemia, while CHOP knockout blocked toxic effects of EtOH and PA. Our study suggested that targeting UPR-signaling pathways is a promising, novel approach to reducing EtOH and saturated fatty acid-induced metabolic complications.

  11. Cadmium toxicity induces ER stress and apoptosis via impairing energy homoeostasis in cardiomyocytes

    PubMed Central

    Chen, Chun-yan; Zhang, Shao-li; Liu, Zhi-yong; Tian, Yong; Sun, Qian

    2015-01-01

    Cadmium, a highly toxic environmental pollutant, is reported to induce toxicity and apoptosis in multiple organs and cells, all possibly contributing to apoptosis in certain pathophysiologic situations. Previous studies have described that cadmium toxicity induces biochemical and physiological changes in the heart and finally leads to cardiac dysfunctions, such as decreasing contractile tension, rate of tension development, heart rate, coronary flow rate and atrioventricular node conductivity. Although many progresses have been made, the mechanism responsible for cadmium-induced cellular alternations and cardiac toxicity is still not fully understood. In the present study, we demonstrated that cadmium toxicity induced dramatic endoplasmic reticulum (ER) stress and impaired energy homoeostasis in cultured cardiomyocytes. Moreover, cadmium toxicity may inhibit protein kinase B (AKT)/mTOR (mammalian target of rapamycin) pathway to reduce energy productions, by either disrupting the glucose metabolism or inhibiting mitochondrial respiratory gene expressions. Our work will help to reveal a novel mechanism to clarify the role of cadmium toxicity to cardiomyocytes and provide new possibilities for the treatment of cardiovascular diseases related to cadmium toxicity. PMID:26182376

  12. Pancreatic beta cells are highly susceptible to oxidative and ER stresses during the development of diabetes.

    PubMed

    Gorasia, Dhana G; Dudek, Nadine L; Veith, Paul D; Shankar, Renu; Safavi-Hemami, Helena; Williamson, Nicholas A; Reynolds, Eric C; Hubbard, Michael J; Purcell, Anthony W

    2015-02-01

    The complex interplay of many cell types and the temporal heterogeneity of pancreatic islet composition obscure the direct role of resident alpha and beta cells in the development of Type 1 diabetes. Therefore, in addition to studying islets isolated from non-obese diabetic mice, we analyzed homogeneous cell populations of murine alpha (αTC-1) and beta (NIT-1) cell lines to understand the role and differential survival of these two predominant islet cell populations. A total of 56 proteins in NIT-1 cells and 50 in αTC-1 cells were differentially expressed when exposed to proinflammatory cytokines. The major difference in the protein expression between cytokine-treated NIT-1 and αTC-1 cells was free radical scavenging enzymes. A similar observation was made in cytokine-treated whole islets, where a comprehensive analysis of subcellular fractions revealed that 438 unique proteins were differentially expressed under inflammatory conditions. Our data indicate that beta cells are relatively susceptible to ER and oxidative stress and reveal key pathways that are dysregulated in beta cells during cytokine exposure. Additionally, in the islets, inflammation also leads to enhanced antigen presentation, which completes a three-way insult on beta cells, rendering them targets of infiltrating T lymphocytes.

  13. CCAAT/Enhancer Binding Protein β in relation to ER Stress, Inflammation, and Metabolic Disturbances

    PubMed Central

    van der Krieken, Sophie E.; Popeijus, Herman E.; Mensink, Ronald P.; Plat, Jogchum

    2015-01-01

    The prevalence of the metabolic syndrome and underlying metabolic disturbances increase rapidly in developed countries. Various molecular targets are currently under investigation to unravel the molecular mechanisms that cause these disturbances. This is done in attempt to counter or prevent the negative health consequences of the metabolic disturbances. Here, we reviewed the current knowledge on the role of C/EBP-β in these metabolic disturbances. C/EBP-β deletion in mice resulted in downregulation of hepatic lipogenic genes and increased expression of β-oxidation genes in brown adipose tissue. Furthermore, C/EBP-β is important in the differentiation and maturation of adipocytes and is increased during ER stress and proinflammatory conditions. So far, studies were only conducted in animals and in cell systems. The results found that C/EBP-β is an important transcription factor within the metabolic disturbances of the metabolic system. Therefore, it is interesting to examine the potential role of C/EBP-β at molecular and physiological level in humans. PMID:25699273

  14. CHOP Potentially Co-Operates with FOXO3a in Neuronal Cells to Regulate PUMA and BIM Expression in Response to ER Stress

    PubMed Central

    Ghosh, Arindam P.; Klocke, Barbara J.; Ballestas, Mary E.; Roth, Kevin A.

    2012-01-01

    Endoplasmic reticulum (ER) stress-induced apoptosis has been implicated in various neurodegenerative diseases including Parkinson Disease, Alzheimer Disease and Huntington Disease. PUMA (p53 upregulated modulator of apoptosis) and BIM (BCL2 interacting mediator of cell death), pro-apoptotic BH3 domain-only, BCL2 family members, have previously been shown to regulate ER stress-induced cell death, but the upstream signaling pathways that regulate this response in neuronal cells are incompletely defined. Consistent with previous studies, we show that both PUMA and BIM are induced in response to ER stress in neuronal cells and that transcriptional induction of PUMA regulates ER stress-induced cell death, independent of p53. CHOP (C/EBP homologous protein also known as GADD153; gene name Ddit3), a critical initiator of ER stress-induced apoptosis, was found to regulate both PUMA and BIM expression in response to ER stress. We further show that CHOP knockdown prevents perturbations in the AKT (protein kinase B)/FOXO3a (forkhead box, class O, 3a) pathway in response to ER stress. CHOP co-immunoprecipitated with FOXO3a in tunicamycin treated cells, suggesting that CHOP may also regulate other pro-apoptotic signaling cascades culminating in PUMA and BIM activation and cell death. In summary, CHOP regulates the expression of multiple pro-apoptotic BH3-only molecules through multiple mechanisms, making CHOP an important therapeutic target relevant to a number of neurodegenerative conditions. PMID:22761832

  15. Overexpression of gamma-tocopherol methyl transferase gene in transgenic Brassica juncea plants alleviates abiotic stress: physiological and chlorophyll a fluorescence measurements.

    PubMed

    Yusuf, Mohd Aslam; Kumar, Deepak; Rajwanshi, Ravi; Strasser, Reto Jörg; Tsimilli-Michael, Merope; Govindjee; Sarin, Neera Bhalla

    2010-08-01

    Tocopherols (vitamin E) are lipid soluble antioxidants synthesized by plants and some cyanobacteria. We have earlier reported that overexpression of the gamma-tocopherol methyl transferase (gamma-TMT) gene from Arabidopsis thaliana in transgenic Brassica juncea plants resulted in an over six-fold increase in the level of alpha-tocopherol, the most active form of all the tocopherols. Tocopherol levels have been shown to increase in response to a variety of abiotic stresses. In the present study on Brassica juncea, we found that salt, heavy metal and osmotic stress induced an increase in the total tocopherol levels. Measurements of seed germination, shoot growth and leaf disc senescence showed that transgenic Brassica juncea plants overexpressing the gamma-TMT gene had enhanced tolerance to the induced stresses. Analysis of the chlorophyll a fluorescence rise kinetics, from the initial "O" level to the "P" (the peak) level, showed that there were differential effects of the applied stresses on different sites of the photosynthetic machinery; further, these effects were alleviated in the transgenic (line 16.1) Brassica juncea plants. We show that alpha-tocopherol plays an important role in the alleviation of stress induced by salt, heavy metal and osmoticum in Brassica juncea. PMID:20144585

  16. Alleviating salt stress in tomato seedlings using Arthrobacter and Bacillus megaterium isolated from the rhizosphere of wild plants grown on saline-alkaline lands.

    PubMed

    Fan, Pengfei; Chen, Daitao; He, Yanan; Zhou, Qingxia; Tian, Yongqiang; Gao, Lihong

    2016-11-01

    Salt-induced soil degradation is common in farmlands and limits the growth and development of numerous crop plants in the world. In this study, we isolated salt-tolerant bacteria from the rhizosphere of Tamarix chinensis, Suaeda salsa and Zoysia sinica, which are common wild plants grown on a saline-alkaline land, to test these bacteria's efficiency in alleviating salt stress in tomato plants. We screened out seven strains (TF1-7) that are efficient in reducing salt stress in tomato seedlings. The sequence data of 16S rRNA genes showed that these strains belong to Arthrobacter and Bacillus megaterium. All strains could hydrolyze casein and solubilize phosphate, and showed at least one plant growth promotion (PGP)-related gene, indicating their potential in promoting plant growth. The Arthrobacter strains TF1 and TF7 and the Bacillus megaterium strain TF2 and TF3 could produce indole acetic acid under salt stress, further demonstrating their PGP potential. Tomato seed germination, seedling length, vigor index, and plant fresh and dry weight were enhanced by inoculation of Arthrobacter and B. megaterium strains under salt stress. Our results demonstrated that salt-tolerant bacteria isolated from the rhizosphere of wild plants grown on saline-alkaline lands could be used for alleviating salt stress in crop plants. PMID:27196364

  17. Self-association and BiP dissociation are not sufficient for activation of the ER stress sensor Ire1.

    PubMed

    Oikawa, Daisuke; Kimata, Yukio; Kohno, Kenji

    2007-05-01

    Ire1 is a type I transmembrane protein located on the endoplasmic reticulum (ER). Upon ER stress, Ire1 releases the ER chaperone BiP and self-associates. This activates Ire1 and triggers the unfolded protein response in the yeast Saccharomyces cerevisiae. We isolated and characterized an Ire1 luminal domain mutant lacking both the N-terminal and the juxtamembrane loosely folded subregions. Although this 'core' mutant was able to self-associate and failed to bind BiP even under nonstressed conditions, its activation was still dependent on ER stress. Furthermore, although substitution of Pro for Ser103 (S103P) in the luminal domain of full-length Ire1 caused neither BiP dissociation nor a change in self-association, the substitution in combination with the core mutation resulted in constitutive activation. This phenotype of the S103P mutation required a cluster of positively charged amino acid residues (Arg or Lys) located close to the mutation site in the Ire1 sequence. These observations indicate that in addition to BiP dissociation and self-association of Ire1, another unknown change on the luminal side is crucial for Ire1 activation. PMID:17452628

  18. ER Stress Mediates TiAl6V4 Particle-Induced Peri-Implant Osteolysis by Promoting RANKL Expression in Fibroblasts

    PubMed Central

    Wang, Zhenheng; Liu, Naicheng; Shi, Tongguo; Zhou, Gang; Wang, Zhenzhen; Gan, Jingjing; Guo, Ting; Qian, Hongbo; Bao, Nirong; Zhao, Jianning

    2015-01-01

    Wear particle-induced osteolysis is a major cause of aseptic loosening, which is one of the most common reasons for total hip arthroplasty (THA) failure. Previous studies have shown that the synovial fibroblasts present in the periprosthetic membrane are important targets of wear debris during osteolysis. However, the interaction mechanisms between the wear debris and fibroblasts remain largely unknown. In the present study, we investigated the effect of ER (endoplasmic reticulum) stress induced by TiAl6V4 particles (TiPs) in human synovial fibroblasts and calvarial resorption animal models. The expression of ER stress markers, including IRE1-α, GRP78/Bip and CHOP, were determined by western blot in fibroblasts that had been treated with TiPs for various times and concentration. To address whether ER stress was involved in the expression of RANKL, the effects of ER stress blockers (including 4-PBA and TUDCA) on the expression of RANKL in TiPs-treated fibroblasts were examined by real-time PCR, western blot and ELISA. Osteoclastogenesis was assessed by tartrate resistant acid phosphatase (TRAP) staining. Our study demonstrated that ER stress markers were markedly upregulated in TiPs-treated fibroblasts. Blocking ER stress significantly reduced the TiPs-induced expression of RANKL both in vitro and in vivo. Moreover, the inhibition of ER stress ameliorated wear particle-induced osteolysis in animal models. Taken together, these results suggested that the expression of RANKL induced by TiPs was mediated by ER stress in fibroblasts. Therefore, down regulating the ER stress of fibroblasts represents a potential therapeutic approach for wear particle-induced periprosthetic osteolysis. PMID:26366858

  19. Evaluation of Transient Pin-Stress Requirements for Spacecraft Launching in Lightning Environments. Pain Free Analysis to Alleviate Those Pin Stress Headaches

    NASA Technical Reports Server (NTRS)

    Edwards, Paul; Terseck, Alex; Trout, Dawn

    2016-01-01

    Spacecraft are generally protected from direct lightning attachment by encapsulation within the payload fairing of a launch vehicle and the ground structures that exist at the launch site. Regardless of where lightning strikes, potentially damaging indirect effects prevail from the coupling of electromagnetic fields into a loop created by outer shield of the payload umbilical. The energy coupled into individual spacecraft circuits is dependent on the umbilical current drive, the cable transfer impedance and the source/ load circuitry, and the reference potential used. Lightning induced transient susceptibility of the spacecraft avionics needs to be fully understood in order to define realistic re-test criteria in the event of a lightning occurrence during the launch campaign. Use of standards such as RTCA/DO-160 & SAE 5412 has some applicability but do not represent the indirect environment adequately. This paper evaluates the launch pad environments, the measurement data available, and computer simulations to provide pain-free analysis to alleviate the transient pin-stress headaches for spacecraft launching in Lightning environments.

  20. Simultaneous inhibition of the ubiquitin-proteasome system and autophagy enhances apoptosis induced by ER stress aggravators in human pancreatic cancer cells.

    PubMed

    Li, Xu; Zhu, Feng; Jiang, Jianxin; Sun, Chengyi; Zhong, Qing; Shen, Ming; Wang, Xin; Tian, Rui; Shi, Chengjian; Xu, Meng; Peng, Feng; Guo, Xingjun; Hu, Jun; Ye, Dawei; Wang, Min; Qin, Renyi

    2016-09-01

    In contrast to normal tissue, cancer cells display profound alterations in protein synthesis and degradation. Therefore, proteins that regulate endoplasmic reticulum (ER) homeostasis are being increasingly recognized as potential therapeutic targets. The ubiquitin-proteasome system and autophagy are crucially important for proteostasis in cells. However, interactions between autophagy, the proteasome, and ER stress pathways in cancer remain largely undefined. This study demonstrated that withaferin-A (WA), the biologically active withanolide extracted from Withania somnifera, significantly increased autophagosomes, but blocked the degradation of autophagic cargo by inhibiting SNARE-mediated fusion of autophagosomes and lysosomes in human pancreatic cancer (PC) cells. WA specifically induced proteasome inhibition and promoted the accumulation of ubiquitinated proteins, which resulted in ER stress-mediated apoptosis. Meanwhile, the impaired autophagy at early stage induced by WA was likely activated in response to ER stress. Importantly, combining WA with a series of ER stress aggravators enhanced apoptosis synergistically. WA was well tolerated in mice, and displayed synergism with ER stress aggravators to inhibit tumor growth in PC xenografts. Taken together, these findings indicate that simultaneous suppression of 2 key intracellular protein degradation systems rendered PC cells vulnerable to ER stress, which may represent an avenue for new therapeutic combinations for this disease. PMID:27308733

  1. ER stress related factor ATF6 and caspase-12 trigger apoptosis in neonatal hypoxic-ischemic encephalopathy

    PubMed Central

    Liu, Luran; Liu, Chang; Lu, Yuting; Liu, Lina; Jiang, Yan

    2015-01-01

    The specific and available markers proteins of neonatal hypoxic-ischemic encephalopathy (HIE) injury are correlated with disease severity and the disability in childhood. Exploring the mechanism of HIE is very helpful to the targeted therapeutic approach in clinical. This study aims to explore the cell death-related proteins or biomarkers that plays roles in the HIE injury. In this study, 15 patients were included the 487 autopsies patients performed at the Department of Pathology. The lactate dehydrogenase (LDH) assay was used to detect the cell viability of NGF-differentiated PC12 cell. TUNEL assay was employed to examine the apoptotic cells in embedded slides samples. Three ER stress-related protein, including ATF6, p-Perk and IRE-1 were investigated using Western blot assay for the ER stress examination. The apoptosis associated caspase-12 and CHOP protein were detected by Western blot. The results indicated that LDH activity of living cells during hypoxia was significantly enhanced to 45% and 64% after 8 hours and 24 hours. The TUNEL results showed that plenty of the PC12 cells became the positive staining cells when treated with 0.1% O2 hypoxia. ER stress UPR pathway protein, cleaved ATF6, was increased significantly when treated with 0.1% O2 compared with the cells treated with 20% O2. Furthermore, the caspase 12 activation was triggered when the cells treated with the 0.1% O2. In conclusion, apoptosis is served as an important factor that triggers the HIE brain injury through cleaving the ATF6 and caspase-12 ER stress-related protein. PMID:26261584

  2. Deep-brain magnetic stimulation promotes adult hippocampal neurogenesis and alleviates stress-related behaviors in mouse models for neuropsychiatric disorders

    PubMed Central

    2014-01-01

    Background Repetitive Transcranial Magnetic Stimulation (rTMS)/ Deep-brain Magnetic Stimulation (DMS) is an effective therapy for various neuropsychiatric disorders including major depression disorder. The molecular and cellular mechanisms underlying the impacts of rTMS/DMS on the brain are not yet fully understood. Results Here we studied the effects of deep-brain magnetic stimulation to brain on the molecular and cellular level. We examined the adult hippocampal neurogenesis and hippocampal synaptic plasticity of rodent under stress conditions with deep-brain magnetic stimulation treatment. We found that DMS promotes adult hippocampal neurogenesis significantly and facilitates the development of adult new-born neurons. Remarkably, DMS exerts anti-depression effects in the learned helplessness mouse model and rescues hippocampal long-term plasticity impaired by restraint stress in rats. Moreover, DMS alleviates the stress response in a mouse model for Rett syndrome and prolongs the life span of these animals dramatically. Conclusions Deep-brain magnetic stimulation greatly facilitates adult hippocampal neurogenesis and maturation, also alleviates depression and stress-related responses in animal models. PMID:24512669

  3. Calpain inhibitor attenuates ER stress-induced apoptosis in injured spinal cord after bone mesenchymal stem cells transplantation.

    PubMed

    Wang, Chao; Shi, Dongling; Song, Xinghui; Chen, Yingying; Wang, Linlin; Zhang, Xiaoming

    2016-07-01

    Bone marrow mesenchymal stem cells (BMSCs) therapy for tissue repair is limited by low survival of cells transplanted in the recipient sites after spinal cord injury (SCI). Here, we investigated the effects of a calpain inhibitor (MDL28170) on BMSCs survival by a rat model of spinal cord injury in vitro and in vivo. Conditioned medium from hypoxia injured VSC4.1 motor neurons (Hypoxia-CM) were collected to mimic the micro-environment of injured spinal cord. Tunicamycin was also applied to induce endoplasmic reticulum (ER) stress in BMSCs. The CCK-8 assay, LDH leakage assay and flow cytometer assay demonstrated that MDL28170 could enhance BMSCs survival in response to Hypoxia-CM and tunicamycin. Moreover, MDL28170 significantly enhanced GFP-positive BMSCs survival in vivo after transplantation into the contused spinal cord of SCI rats. The protective effects of MDL28170 on BMSCs survival may inhibit the activation of calpain and the downstream ER stress-induced apoptosis. The present results suggested for the first time that MDL28170 with BMSCs transplant helped to rescue cells in injured spinal cord by modulating the ER stress-induced apoptosis. The calpain inhibitor, MDL28170 may have the promising new strategies for promoting the survival of transplanted BMSCs on cell-based regenerative medicine.

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

    PubMed

    Shinde, Vishal M; Sizova, Olga S; Lin, Jonathan H; LaVail, Matthew M; Gorbatyuk, Marina S

    2012-01-01

    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.

  5. Alleviation of salt stress by enterobacter sp. EJ01 in tomato and Arabidopsis is accompanied by up-regulation of conserved salinity responsive factors in plants.

    PubMed

    Kim, Kangmin; Jang, Ye-Jin; Lee, Sang-Myeong; Oh, Byung-Taek; Chae, Jong-Chan; Lee, Kui-Jae

    2014-02-01

    Microbiota in the niches of the rhizosphere zones can affect plant growth and responses to environmental stress conditions via mutualistic interactions with host plants. Specifically, some beneficial bacteria, collectively referred to as Plant Growth Promoting Rhizobacteria (PGPRs), increase plant biomass and innate immunity potential. Here, we report that Enterobacter sp. EJ01, a bacterium isolated from sea china pink (Dianthus japonicus thunb) in reclaimed land of Gyehwa-do in Korea, improved the vegetative growth and alleviated salt stress in tomato and Arabidopsis. EJ01 was capable of producing 1-aminocy-clopropane-1-carboxylate (ACC) deaminase and also exhibited indole-3-acetic acid (IAA) production. The isolate EJ01 conferred increases in fresh weight, dry weight, and plant height of tomato and Arabidopsis under both normal and high salinity conditions. At the molecular level, short-term treatment with EJ01 increased the expression of salt stress responsive genes such as DREB2b, RD29A, RD29B, and RAB18 in Arabidopsis. The expression of proline biosynthetic genes (i.e. P5CS1 and P5CS2) and of genes related to priming processes (i.e. MPK3 and MPK6) were also up-regulated. In addition, reactive oxygen species scavenging activities were enhanced in tomatoes treated with EJ01 in stressed conditions. GFP-tagged EJ01 displayed colonization in the rhizosphere and endosphere in the roots of Arabidopsis. In conclusion, the newly isolated Enterobacter sp. EJ01 is a likely PGPR and alleviates salt stress in host plants through multiple mechanisms, including the rapid up-regulation of conserved plant salt stress responsive signaling pathways.

  6. Alleviation of Salt Stress by Enterobacter sp. EJ01 in Tomato and Arabidopsis Is Accompanied by Up-Regulation of Conserved Salinity Responsive Factors in Plants

    PubMed Central

    Kim, Kangmin; Jang, Ye-Jin; Lee, Sang-Myeong; Oh, Byung-Taek; Chae, Jong-Chan; Lee, Kui-Jae

    2014-01-01

    Microbiota in the niches of the rhizosphere zones can affect plant growth and responses to environmental stress conditions via mutualistic interactions with host plants. Specifically, some beneficial bacteria, collectively referred to as Plant Growth Promoting Rhizobacteria (PGPRs), increase plant biomass and innate immunity potential. Here, we report that Enterobacter sp. EJ01, a bacterium isolated from sea china pink (Dianthus japonicus thunb) in reclaimed land of Gyehwa-do in Korea, improved the vegetative growth and alleviated salt stress in tomato and Arabidopsis. EJ01 was capable of producing 1-aminocy-clopropane-1-carboxylate (ACC) deaminase and also exhibited indole-3-acetic acid (IAA) production. The isolate EJ01 conferred increases in fresh weight, dry weight, and plant height of tomato and Arabidopsis under both normal and high salinity conditions. At the molecular level, short-term treatment with EJ01 increased the expression of salt stress responsive genes such as DREB2b, RD29A, RD29B, and RAB18 in Arabidopsis. The expression of proline biosynthetic genes (i.e. P5CS1 and P5CS2) and of genes related to priming processes (i.e. MPK3 and MPK6) were also up-regulated. In addition, reactive oxygen species scavenging activities were enhanced in tomatoes treated with EJ01 in stressed conditions. GFP-tagged EJ01 displayed colonization in the rhizosphere and endosphere in the roots of Arabidopsis. In conclusion, the newly isolated Enterobacter sp. EJ01 is a likely PGPR and alleviates salt stress in host plants through multiple mechanisms, including the rapid up-regulation of conserved plant salt stress responsive signaling pathways. PMID:24598995

  7. Absence of Nceh1 augments 25-hydroxycholesterol-induced ER stress and apoptosis in macrophages[S

    PubMed Central

    Sekiya, Motohiro; Yamamuro, Daisuke; Ohshiro, Taichi; Honda, Akira; Takahashi, Manabu; Kumagai, Masayoshi; Sakai, Kent; Nagashima, Shuichi; Tomoda, Hiroshi; Igarashi, Masaki; Okazaki, Hiroaki; Yagyu, Hiroaki; Osuga, Jun-ichi; Ishibashi, Shun

    2014-01-01

    An excess of cholesterol and/or oxysterols induces apoptosis in macrophages, contributing to the development of advanced atherosclerotic lesions. In foam cells, these sterols are stored in esterified forms, which are hydrolyzed by two enzymes: neutral cholesterol ester hydrolase 1 (Nceh1) and hormone-sensitive lipase (Lipe). A deficiency in either enzyme leads to accelerated growth of atherosclerotic lesions in mice. However, it is poorly understood how the esterification and hydrolysis of sterols are linked to apoptosis. Remarkably, Nceh1-deficient thioglycollate-elicited peritoneal macrophages (TGEMs), but not Lipe-deficient TGEMs, were more susceptible to apoptosis induced by oxysterols, particularly 25-hydroxycholesterol (25-HC), and incubation with 25-HC caused massive accumulation of 25-HC ester in the endoplasmic reticulum (ER) due to its defective hydrolysis, thereby activating ER stress signaling such as induction of CCAAT/enhancer-binding protein-homologous protein (CHOP). These changes were nearly reversed by inhibition of ACAT1. In conclusion, deficiency of Nceh1 augments 25-HC-induced ER stress and subsequent apoptosis in TGEMs. In addition to reducing the cholesteryl ester content of foam cells, Nceh1 may protect against the pro-apoptotic effect of oxysterols and modulate the development of atherosclerosis. PMID:24891333

  8. Resveratrol triggers ER stress-mediated apoptosis by disrupting N-linked glycosylation of proteins in ovarian cancer cells.

    PubMed

    Gwak, HyeRan; Kim, Soochi; Dhanasekaran, Danny N; Song, Yong Sang

    2016-02-28

    Malignant tumors have a high glucose demand and alter cellular metabolism to survive. Herein, focusing on the utility of glucose metabolism as a therapeutic target, we found that resveratrol induced endoplasmic reticulum (ER) stress-mediated apoptosis by interrupting protein glycosylation in a cancer-specific manner. Our results indicated that resveratrol suppressed the hexosamine biosynthetic pathway and interrupted protein glycosylation through GSK3β activation. Application of either biochemical intermediates of the hexosamine pathway or small molecular inhibitors of GSK3β reversed the effects of resveratrol on the disruption of protein glycosylation. Additionally, an ER UDPase, ectonucleoside triphosphate diphosphohydrolase 5 (ENTPD5), modulated protein glycosylation by Akt attenuation in response to resveratrol. By inhibition or overexpression of Akt functions, we confirmed that the glycosylation activities were dependent on ENTPD5 expression and regulated by the action of Akt in ovarian cancer cells. Resveratrol-mediated disruption of protein glycosylation induced cellular apoptosis as indicated by the up-regulation of GADD153, followed by the activation of ER-stress sensors (PERK and ATF6α). Thus, our results provide novel insight into cancer cell metabolism and protein glycosylation as a therapeutic target for cancers.

  9. Endoplasmic reticulum stress and the on site function of resident PTP1B.

    PubMed

    Popov, Doina

    2012-06-15

    Growing evidence links the stress at the endoplasmic reticulum (ER) to pathologies such as diabetes mellitus, obesity, liver, heart, renal and neurodegenerative diseases, endothelial dysfunction, atherosclerosis, and cancer. Therefore, identification of molecular pathways beyond ER stress and their appropriate modulation might alleviate the stress, and direct toward novel tools to fight this disturbance. An interesting resident of the ER membrane is protein tyrosine phosphatase 1B (PTP1B), an enzyme that negatively regulates insulin and leptin signaling, contributing to insulin and leptin resistance. Recently, new functions of PTP1B have been established linked to ER stress response. This review evaluates the novel data on ER stressors, discusses the mechanisms beyond PTP1B function in the ER stress response, and emphasizes the potential therapeutic exploitation of PTP1B to relieve ER stress. PMID:22609202

  10. 4-Phenylbutyric acid reduces mutant-TGFBIp levels and ER stress through activation of ERAD pathway in corneal fibroblasts of granular corneal dystrophy type 2.

    PubMed

    Choi, Seung-Il; Lee, Eunhee; Jeong, Jang Bin; Akuzum, Begum; Maeng, Yong-Sun; Kim, Tae-Im; Kim, Eung Kweon

    2016-09-01

    Granular corneal dystrophy type 2 (GCD2) is caused by a point mutation (R124H) in the transforming growth factor β-induced (TGFBI) gene. In GCD2 corneal fibroblasts, secretion of the accumulated mutant TGFBI-encoded protein (TGFBIp) is delayed via the endoplasmic reticulum (ER)/Golgi-dependent secretory pathway. However, ER stress as the pathogenic mechanism underlying GCD2 has not been fully characterized. The aim of this study was to confirm whether ER stress is linked to GCD2 pathogenesis and whether the chemical chaperone, 4-phenylbutyric acid (4-PBA), could be exploited as a therapy for GCD2. We found that the ER chaperone binding immunoglobulin protein (BiP) and the protein disulfide isomerase (PDI) were elevated in GCD2. Western bolt analysis also showed a significant increase in both the protein levels and the phosphorylation of the key ER stress kinases, inositol-requiring enzyme 1α (IRE1α) and double stranded RNA activated protein kinase (PKR)-like ER kinase, as well as in levels of their downstream targets, X box-binding protein 1 (XBP1) and activating transcription factor 4, respectively, in GCD2 corneal fibroblasts. GCD2 cells were found to be more susceptible to ER stress-induced cell death than were wild-type corneal fibroblasts. Treatment with 4-PBA considerably reduced the levels of BiP, IRE1α, and XBP1 in GCD2 cells; notably, 4-PBA treatment significantly reduced the levels of TGFBIp without change in TGFBI mRNA levels. In addition, TGFBIp levels were significantly reduced under ER stress and this reduction was considerably suppressed by the ubiquitin proteasome inhibitor MG132, indicating TGFBIp degradation via the ER-associated degradation pathway. Treatment with 4-PBA not only protected against the GCD2 cell death induced by ER stress but also significantly suppressed the MG132-mediated increase in TGFBIp levels under ER stress. Together, these results suggest that ER stress might comprise an important factor in GCD2 pathophysiology and

  11. Curcumin abates hypoxia-induced oxidative stress based-ER stress-mediated cell death in mouse hippocampal cells (HT22) by controlling Prdx6 and NF-κB regulation

    PubMed Central

    Chhunchha, Bhavana; Fatma, Nigar; Kubo, Eri; Rai, Prerana; Singh, Sanjay P.

    2013-01-01

    Oxidative stress and endoplasmic reticulum (ER) stress are emerging as crucial events in the etiopathology of many neurodegenerative diseases. While the neuroprotective contributions of the dietary compound curcumin has been recognized, the molecular mechanisms underlying curcumin's neuroprotection under oxidative and ER stresses remains elusive. Herein, we show that curcumin protects HT22 from oxidative and ER stresses evoked by the hypoxia (1% O2 or CoCl2 treatment) by enhancing peroxiredoxin 6 (Prdx6) expression. Cells exposed to CoCl2 displayed reduced expression of Prdx6 with higher reactive oxygen species (ROS) expression and activation of NF-κB with IκB phosphorylation. When NF-κB activity was blocked by using SN50, an inhibitor of NF-κB, or cells treated with curcumin, the repression of Prdx6 expression was restored, suggesting the involvement of NF-κB in modulating Prdx6 expression. These cells were enriched with an accumulation of ER stress proteins, C/EBP homologous protein (CHOP), GRP/78, and calreticulin, and had activated states of caspases 12, 9, and 3. Reinforced expression of Prdx6 in HT22 cells by curcumin reestablished survival signaling by reducing propagation of ROS and blunting ER stress signaling. Intriguingly, knockdown of Prdx6 by antisense revealed that loss of Prdx6 contributed to cell death by sustaining enhanced levels of ER stress-responsive proapoptotic proteins, which was due to elevated ROS production, suggesting that Prdx6 deficiency is a cause of initiation of ROS-mediated ER stress-induced apoptosis. We propose that using curcumin to reinforce the naturally occurring Prdx6 expression and attenuate ROS-based ER stress and NF-κB-mediated aberrant signaling improves cell survival and may provide an avenue to treat and/or postpone diseases associated with ROS or ER stress. PMID:23364261

  12. The lumen-facing domain is important for the biological function and organelle-to-organelle movement of bZIP28 during ER stress in Arabidopsis.

    PubMed

    Sun, Le; Lu, Sun-Jie; Zhang, Shuang-Shuang; Zhou, Shun-Fan; Sun, Ling; Liu, Jian-Xiang

    2013-09-01

    The membrane-associated transcription factor, bZIP28, is relocated from the endoplasmic reticulum (ER) to the Golgi and proteolytically released from the membrane mediated by two proteases, S1P and S2P, in response to ER stress in Arabidopsis. The activated N-terminal domain recruits nuclear factor Y (NF-Y) subunits in the nucleus to regulate ER stress downstream genes. Little is known about the functions of the bZIP28 C-terminal lumen-facing domain. Here, we provide novel insights into how the ER lumen-facing domain affects the biological function and organelle-to-organelle movement of bZIP28 in the ER stress response. First, we demonstrated the functional redundancy of bZIP28 and bZIP60 by generation and analysis of the bZIP28 and bZIP60 double mutant zip28zip60. Subsequent genetic complementation experiments in zip28zip60 background with deletions on bZIP28 lumen-facing domain highlighted the importance of lumen-facing domain for its in vivo function of bZIP28 in the ER stress response. The protein subcellular localization and Western blotting results further revealed that the bZIP28 lumen-facing domain contains ER retention signal which is important for the proteolytic activation of bZIP28. Thus, the bZIP28 lumen-facing C-terminus plays important roles in the ER-to-Golgi movement of bZIP28, which may contribute to the sensing of the ER stress.

  13. Late Phase of the Endoplasmic Reticulum Stress Response Pathway Is Regulated by Hog1 MAP Kinase*

    PubMed Central

    Bicknell, Alicia A.; Tourtellotte, Joel; Niwa, Maho

    2010-01-01

    When unfolded proteins accumulate in the endoplasmic reticulum (ER) causing ER stress, the unfolded protein response (UPR) responds rapidly to induce a transcriptional program that functions to alleviate the stress. However, under extreme conditions, when UPR activation is not sufficient to alleviate ER stress, the stress may persist long term. Very little is known about how the cell responds to persistent ER stress that is not resolved by the immediate activation of the UPR. We show that Hog1 MAP kinase becomes phosphorylated during the late stage of ER stress and helps the ER regain homeostasis. Although Hog1 is well known to function in osmotic stress and cell wall integrity pathways, we show that the activation mechanism for Hog1 during ER stress is distinct from both of these pathways. During late stage ER stress, upon phosphorylation, Hog1 translocates into the nucleus and regulates gene expression. Subsequently, Hog1 returns to the cytoplasm, where its phosphorylation levels remain high. From its cytoplasmic location, Hog1 contributes to the activation of autophagy by enhancing the stability of Atg8, a critical autophagy protein. Thus, Hog1 coordinates a multifaceted response to persistent ER stress. PMID:20382742

  14. ER stress in pancreatic beta cells: the thin red line between adaptation and failure.

    PubMed

    Eizirik, Decio L; Cnop, Miriam

    2010-01-01

    Secretory cells, such as pancreatic beta cells, face the challenge of increasing protein synthesis severalfold during acute or chronic stimulation. This poses a burden on the endoplasmic reticulum (ER), the organelle where proinsulin synthesis and folding takes place. Thus, beta cells use various adaptive mechanisms to adjust the functional capacity of the ER to the prevailing demand. These check-and-balance mechanisms are collectively known as the unfolded protein response (UPR). It remains unclear how UPR signaling is ultimately regulated and what delineates the boundaries between a physiological and a pathological response. New discoveries point to the divergent effects of acute and chronic metabolic fluxes and chemical ER stressors on the formation of complexes among UPR transducers, scaffold proteins, and phosphatases. These and other findings provide a first glimpse on how different signals trigger diverging UPR outcomes. PMID:20179270

  15. ER stress stimulates production of the key antimicrobial peptide, cathelicidin, by forming a previously unidentified intracellular S1P signaling complex

    PubMed Central

    Park, Kyungho; Ikushiro, Hiroko; Shin, Kyong-Oh; Kim, Young il; Kim, Jong Youl; Lee, Yong-Moon; Yano, Takato; Holleran, Walter M.; Elias, Peter; Uchida, Yoshikazu

    2016-01-01

    We recently identified a previously unidentified sphingosine-1-phosphate (S1P) signaling mechanism that stimulates production of a key innate immune element, cathelicidin antimicrobial peptide (CAMP), in mammalian cells exposed to external perturbations, such as UVB irradiation and other oxidative stressors that provoke subapoptotic levels of endoplasmic reticulum (ER) stress, independent of the well-known vitamin D receptor-dependent mechanism. ER stress increases cellular ceramide and one of its distal metabolites, S1P, which activates NF-κB followed by C/EBPα activation, leading to CAMP production, but in a S1P receptor-independent fashion. We now show that S1P activates NF-κB through formation of a previously unidentified signaling complex, consisting of S1P, TRAF2, and RIP1 that further associates with three stress-responsive proteins; i.e., heat shock proteins (GRP94 and HSP90α) and IRE1α. S1P specifically interacts with the N-terminal domain of heat shock proteins. Because this ER stress-initiated mechanism is operative in both epithelial cells and macrophages, it appears to be a universal, highly conserved response, broadly protective against diverse external perturbations that lead to increased ER stress. Finally, these studies further illuminate how ER stress and S1P orchestrate critical stress-specific signals that regulate production of one protective response by stimulating production of the key innate immune element, CAMP. PMID:26903652

  16. Alleviative effects of α-lipoic acid supplementation on acute heat stress-induced thermal panting and the level of plasma nonesterified fatty acids in hypothyroid broiler chickens.

    PubMed

    Hamano, Y

    2012-01-01

    1. The present study was conducted to examine the effects of α-lipoic acid on hypothyroidism-induced negative growth performance and whether α-lipoic acid alleviates acute heat stress in relation to hypothyroid status. 2. Female broiler chickens (14 d-old) were fed diets supplemented with α-lipoic acid (100 mg/kg) and an antithyroid substance, propylthiouracil (200 mg/kg), for 20 d under thermoneutral conditions (25°C). At 42 d of age, chickens were exposed to a high ambient temperature (36°C, 60% RH) for 4 h. 3. Under the thermoneutral condition, propylthiouracil administration decreased feed efficiency and concomitantly increased adipose tissue and thyroid gland weights. Plasma nonesterified fatty acids and triacylglycerol were also increased by propylthiouracil administration. However, α-lipoic acid supplementation did not affect the hypothyroidism-induced effects. 4. In hypothyroid chickens, the rise in respiratory rate induced by heat exposure was greatly inhibited by α-lipoic acid administration at 1 h, but this effect had disappeared at 4 h. In addition, a similar inhibitory effect on the concentrations of plasma nonesterified fatty acids was subsequently observed at 4 h. 5. Therefore, the present study suggested that α-lipoic acid alleviates acute heat stress if chickens are in a hypothyroid status.

  17. Observation of silicon-mediated alleviation of cadmium stress in maize (Zea mays L.) seedlings via LED-induced chlorophyll fluorescence

    NASA Astrophysics Data System (ADS)

    Gouveia-Neto, Artur S.; Silva, Elias A.; da Silva, Airon José; do Nascimento, Clístenes W. A.

    2013-02-01

    LED-induced chlorophyll fluorescence analysis is exploited to observe, and monitor the time evolution of silicon-induced alleviation of toxicity in maize (Zea mays L.) seedlings in cadmium contaminated soil. Red, and far-red emissions were examined as a function of cadmium-silicon concentrations, during the 20 days period of the seedlings growing process under stress. The chlorophyll fluorescence spectral analysis provided detection, and evaluation of the damage imposed by the metal stress in the early stages of the plant growing process. The technique also provided the time evolution evaluation of the silicon-induced tolerance enhancement of maize plants to cadmium, which is not viable using conventional in vitro spectral analysis techniques

  18. Nitrogen Nutrition Improves the Potential of Wheat (Triticum aestivum L.) to Alleviate the Effects of Drought Stress during Vegetative Growth Periods

    PubMed Central

    Abid, Muhammad; Tian, Zhongwei; Ata-Ul-Karim, Syed Tahir; Cui, Yakun; Liu, Yang; Zahoor, Rizwan; Jiang, Dong; Dai, Tingbo

    2016-01-01

    Efficient nitrogen (N) nutrition has the potential to alleviate drought stress in crops by maintaining metabolic activities even at low tissue water potential. This study was aimed to understand the potential of N to minimize the effects of drought stress applied/occur during tillering (Feekes stage 2) and jointing (Feekes stage 6) growth stages of wheat by observing the regulations and limitations of physiological activities, crop growth rate during drought periods as well as final grain yields at maturity. In present study, pot cultured plants of a wheat cultivar Yangmai-16 were exposed to three water levels [severe stress at 35–40% field capacity (FC), moderate stress at 55–60% FC and well-watered at 75–80% FC] under two N rates (0.24 g and 0.16 g/kg soil). The results showed that the plants under severe drought stress accompanied by low N exhibited highly downregulated photosynthesis, and chlorophyll (Chl) fluorescence during the drought stress periods, and showed an accelerated grain filling rate with shortened grain filling duration (GFD) at post-anthesis, and reduced grain yields. Severe drought-stressed plants especially at jointing, exhibited lower Chl and Rubisco contents, lower efficiency of photosystem II and greater grain yield reductions. In contrast, drought-stressed plants under higher N showed tolerance to drought stress by maintaining higher leaf water potential, Chl and Rubisco content; lower lipid peroxidation associated with higher superoxide dismutase and ascorbate peroxidase activities during drought periods. The plants under higher N showed delayed senescence, increased GFD and lower grain yield reductions. The results of the study suggested that higher N nutrition contributed to drought tolerance in wheat by maintaining higher photosynthetic activities and antioxidative defense system during vegetative growth periods. PMID:27446197

  19. Ceapins inhibit ATF6α signaling by selectively preventing transport of ATF6α to the Golgi apparatus during ER stress.

    PubMed

    Gallagher, Ciara M; Walter, Peter

    2016-01-01

    The membrane-bound transcription factor ATF6α is activated by proteolysis during endoplasmic reticulum (ER) stress. ATF6α target genes encode foldases, chaperones, and lipid biosynthesis enzymes that increase protein-folding capacity in response to demand. The off-state of ATF6α is maintained by its spatial separation in the ER from Golgi-resident proteases that activate it. ER stress induces trafficking of ATF6α. We discovered Ceapins, a class of pyrazole amides, as selective inhibitors of ATF6α signaling that do not inhibit the Golgi proteases or other UPR branches. We show that Ceapins block ATF6α signaling by trapping it in ER-resident foci that are excluded from ER exit sites. Removing the requirement for trafficking by pharmacological elimination of the spatial separation of the ER and Golgi apparatus restored cleavage of ATF6α in the presence of Ceapins. Washout of Ceapins resensitized ATF6α to ER stress. These results suggest that trafficking of ATF6α is regulated by its oligomeric state. PMID:27435962

  20. Ceapins inhibit ATF6α signaling by selectively preventing transport of ATF6α to the Golgi apparatus during ER stress

    PubMed Central

    Gallagher, Ciara M; Walter, Peter

    2016-01-01

    The membrane-bound transcription factor ATF6α is activated by proteolysis during endoplasmic reticulum (ER) stress. ATF6α target genes encode foldases, chaperones, and lipid biosynthesis enzymes that increase protein-folding capacity in response to demand. The off-state of ATF6α is maintained by its spatial separation in the ER from Golgi-resident proteases that activate it. ER stress induces trafficking of ATF6α. We discovered Ceapins, a class of pyrazole amides, as selective inhibitors of ATF6α signaling that do not inhibit the Golgi proteases or other UPR branches. We show that Ceapins block ATF6α signaling by trapping it in ER-resident foci that are excluded from ER exit sites. Removing the requirement for trafficking by pharmacological elimination of the spatial separation of the ER and Golgi apparatus restored cleavage of ATF6α in the presence of Ceapins. Washout of Ceapins resensitized ATF6α to ER stress. These results suggest that trafficking of ATF6α is regulated by its oligomeric state. DOI: http://dx.doi.org/10.7554/eLife.11880.001 PMID:27435962

  1. Nobiletin Induces Protective Autophagy Accompanied by ER-Stress Mediated Apoptosis in Human Gastric Cancer SNU-16 Cells.

    PubMed

    Moon, Jeong Yong; Cho, Somi Kim

    2016-07-14

    Nobiletin, a major component of citrus fruits, is a polymethoxyflavone derivative that exhibits anticancer activity against several forms of cancer, including SNU-16 human gastric cancer cells. To explore the nobiletin-induced cell death mechanism, we examined the changes in protein expression caused by nobiletin in human gastric cancer SNU-16 cells by means of two-dimensional gel electrophoresis (2-DGE), followed by peptide mass fingerprinting (PMF) analysis. Seventeen of 20 selected protein spots were successfully identified, including nine upregulated and eight downregulated proteins. In nobiletin-treated SNU-16 cells the glucose-regulated protein 78 kDa (GRP78) mRNA level was induced most significantly among six proteins related to cell survival and death. Western blot analysis was used to confirm the expression of GRP78 protein. We detected increases in the levels of the ER-stress related proteins inositol requiring enzyme 1 alpha (IRE1-α), activating transcription factor 4 (ATF-4), and C/EBP homology protein (CHOP), as well as GRP78, in response to nobiletin in SNU-16 cells. Furthermore, the ER stress-mediated apoptotic protein caspase-4 was proteolytically activated by nobiletin. Pretreatment with chloroquine, an autophagy inhibitor, strongly augmented apoptosis in SNU-16 cells, as evidenced by decreased cell viability, an increased number of sub-G1 phase cells and increased levels of cleaved PARP. Our results suggest that nobiletin-induced apoptosis in SNU-16 cells is mediated by pathways involving intracellular ER stress-mediated protective autophagy. Thus, the combination of nobiletin and an autophagy inhibitor could be a promising treatment for gastric cancer patients.

  2. Overexpression of violaxanthin de-epoxidase gene alleviates photoinhibition of PSII and PSI in tomato during high light and chilling stress.

    PubMed

    Han, Han; Gao, Shan; Li, Bin; Dong, Xin-Chun; Feng, Hai-Long; Meng, Qing-Wei

    2010-02-15

    A tomato (Lycopersicon esculentum) violaxanthin de-epoxidase gene (LeVDE) was isolated. The deduced amino acid sequence of LeVDE showed high identities with violaxanthin de-epoxidase in other plant species. RNA gel blot analysis showed that the mRNA accumulation of LeVDE in the wild-type (WT) was regulated by diurnal rhythm and temperature. RNA and protein gel blot analyses confirmed that the sense LeVDE was transferred into the tomato genome and overexpressed under the control of 35S-CaMV. The ratio of (A+Z)/(V+A+Z) and the values of non-photochemical quenching (NPQ) were higher in transgenic plants than those in WT under high light and chilling stress (4 degrees C). The net photosynthetic rate (Pn) decreased markedly in WT compared to transgenic lines under high light stress. The maximum quantum yield of primary photochemistry of PSII (Fv/Fm) in transgenic plants decreased more slowly during stresses and recovered faster than that in WT under optimal conditions. The oxidizable P700 in transgenic plants was higher than that in WT under chilling stress. These results suggest that overexpression of LeVDE increased the function of the xanthophyll cycle and alleviated photoinhibition of PSII and PSI in tomato during high light and chilling stress with low irradiance.

  3. Postnatal Treadmill Exercise Alleviates Prenatal Stress-Induced Anxiety in Offspring Rats by Enhancing Cell Proliferation Through 5-Hydroxytryptamine 1A Receptor Activation

    PubMed Central

    2016-01-01

    Purpose: Stress during pregnancy is a risk factor for the development of anxiety-related disorders in offspring later in life. The effects of treadmill exercise on anxiety-like behaviors and hippocampal cell proliferation were investigated using rats exposed to prenatal stress. Methods: Exposure of pregnant rats to a hunting dog in an enclosed room was used to induce stress. Anxiety-like behaviors of offspring were evaluated using the elevated plus maze test. Immunohistochemistry for the detection of 5-bromo-2ʹ- deoxyuridine and doublecortin (DCX) in the hippocampal dentate gyrus and 5-hydroxytryptamine 1A receptors (5-HT1A) in the dorsal raphe was conducted. Brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) levels in the hippocampus were evaluated by western blot analysis. Results: Offspring of maternal rats exposed to stress during pregnancy showed anxiety-like behaviors. Offspring also showed reduced expression of BDNF, TrkB, and DCX in the dentate gyrus, decreased cell proliferation in the hippocampus, and reduced 5-HT1A expression in the dorsal raphe. Postnatal treadmill exercise by offspring, but not maternal exercise during pregnancy, enhanced cell proliferation and expression of these proteins. Conclusions: Postnatal treadmill exercise ameliorated anxiety-like behaviors in offspring of stressed pregnant rats, and the alleviating effect of exercise on these behaviors is hypothesized to result from enhancement of cell proliferation through 5-HT1A activation in offspring rats. PMID:27230461

  4. Kinetin Enhanced 1-Aminocyclopropane-1-Carboxylic Acid Utilization during Alleviation of High Temperatures Stress in Lettuce Seeds.

    PubMed

    Khan, A A; Prusinski, J

    1989-10-01

    The thermoinhibition at 35 and 32 degrees C of pregermination ethylene production and germination in lettuce (Lactuca sativa L. cv Mesa 659) seeds was synergistically or additively alleviated by 0.05 millimolar kinetin (KIN) and 10 millimolar 1-aminocyclopropane-1-carboxylic acid (ACC). The synergistic effect of KIN + ACC on ethylene production and germination at 35 degrees C was inhibited by Co(2+) (44-46%) but not by aminoethoxyvinyl glycine (AVG). The uptake of ACC by the seed was not influenced by KIN. Upon slitting of the seed coats (composed of pericarp, testa and endosperm), following the uptake of chemicals, ACC was readily converted into ethylene at all temperatures, and the synergistic effects of KIN + ACC at 35 degrees C were lost. At 35 degrees C, KIN acted synergistically with ACC or ethephon (ETH) in alleviating the osmotic restraint. At 25 degrees C, ETH was more active than KIN or KIN + ACC in overcoming the osmotic restraint. Thus, the integrity of the seed coats, the KIN-enhanced ACC utilization, and an interaction of KIN with the ethylene produced may be the basis for the synergistic or additive effects of KIN + ACC at high temperature.

  5. Simvastatin inhibits ox-LDL-induced inflammatory adipokines secretion via amelioration of ER stress in 3T3-L1 adipocyte.

    PubMed

    Wu, Zhi-hong; Chen, Ya-qin; Zhao, Shui-ping

    2013-03-01

    Adipocytes behave as a rich source of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Endoplasmic reticulum (ER) stress in adipocytes can alter adipokines secretion and induce inflammation. The aim of this study is to evaluate the effect of simvastatin on the ox-LDL-induced ER stress and expression and secretion of TNF-α and MCP-1 in 3T3-L1 adipocytes. Differentiated adipocytes were treated with various concentrations of ox-LDL (0-100 μg/ml) for 24h with or without simvastatin pre-treatment. The protein expressions of ER stress markers, glucose-regulated protein 78 (GRP78) and C/EBP homology protein (CHOP), were determined by Western blot analysis. The mRNA expressions of TNF-α and MCP-1 were measured by real-time PCR. The protein release of TNF-α and MCP-1 in culture medium were evaluated by ELISA. Ox-LDL treatment led to significant up-regulation of GRP78 and CHOP in dose-dependent manner. The expressions of TNF-α and MCP-1 were dose-dependently increased at mRNA and protein levels after ox-LDL intervention. The effects of ox-LDL on adipocytes were abolished by pre-treatment with 4-phenylbutyrate (4-PBA), a chemical chaperone known to ameliorate ER stress. Simvastatin could inhibit ox-LDL-induced ER stress and reduce the expression of TNF-α and MCP-1 at mRNA and protien level in dose dependent manner. In conclusion, ox-LDL can stimulate the expression and secretion of TNF-α and MCP-1 through its activation of ER stress in adipocytes. Simvastatin might exert direct anti-inflammatory effects in adipocytes through amelioration of ER stress.

  6. Adaptation to ER Stress Is Mediated by Differential Stabilities of Pro-Survival and Pro-Apoptotic mRNAs and Proteins

    PubMed Central

    Rutkowski, D. Thomas; Arnold, Stacey M; Miller, Corey N; Wu, Jun; Li, Jack; Gunnison, Kathryn M; Mori, Kazutoshi; Sadighi Akha, Amir A.; Raden, David; Kaufman, Randal J

    2006-01-01

    The accumulation of unfolded proteins in the endoplasmic reticulum (ER) activates a signaling cascade known as the unfolded protein response (UPR). Although activation of the UPR is well described, there is little sense of how the response, which initiates both apoptotic and adaptive pathways, can selectively allow for adaptation. Here we describe the reconstitution of an adaptive ER stress response in a cell culture system. Monitoring the activation and maintenance of representative UPR gene expression pathways that facilitate either adaptation or apoptosis, we demonstrate that mild ER stress activates all UPR sensors. However, survival is favored during mild stress as a consequence of the intrinsic instabilities of mRNAs and proteins that promote apoptosis compared to those that facilitate protein folding and adaptation. As a consequence, the expression of apoptotic proteins is short-lived as cells adapt to stress. We provide evidence that the selective persistence of ER chaperone expression is also applicable to at least one instance of genetic ER stress. This work provides new insight into how a stress response pathway can be structured to allow cells to avert death as they adapt. It underscores the contribution of posttranscriptional and posttranslational mechanisms in influencing this outcome. PMID:17090218

  7. Peroxisome deficiency-induced ER stress and SREBP-2 pathway activation in the liver of newborn PEX2 knock-out mice.

    PubMed

    Kovacs, Werner J; Charles, Khanichi N; Walter, Katharina M; Shackelford, Janis E; Wikander, Thomas M; Richards, Michael J; Fliesler, Steven J; Krisans, Skaidrite K; Faust, Phyllis L

    2012-06-01

    Disruption of the Pex2 gene leads to peroxisome deficiency and widespread metabolic dysfunction. We previously demonstrated that peroxisomes are critical for maintaining cholesterol homeostasis, using peroxisome-deficient Pex2(-/-) mice on a hybrid Swiss Webster×129S6/SvEv (SW/129) genetic background. Peroxisome deficiency activates hepatic endoplasmic reticulum (ER) stress pathways, leading to dysregulation of the endogenous sterol response mechanism. Herein, we demonstrate a more profound dysregulation of cholesterol homeostasis in newborn Pex2(-/-) mice congenic on a 129S6/SvEv (129) genetic background, and substantial differences between newborn versus postnatal Pex2(-/-) mice in factors that activate ER stress. These differences extend to relationships between activation of genes regulated by SREBP-2 versus PPARα. The SREBP-2 pathway is induced in neonatal Pex2(-/-) livers from 129 and SW/129 strains, despite normal hepatic cholesterol levels. ER stress markers are increased in newborn 129 Pex2(-/-) livers, which occurs in the absence of hepatic steatosis or accumulation of peroxins in the ER. Moreover, the induction of SREBP-2 and ER stress pathways is independent of PPARα activation in livers of newborn 129 and SW/129 Pex2(-/-) mice. Two-week-old wild-type mice treated with the peroxisome proliferator WY-14,643 show strong induction of PPARα-regulated genes and decreased expression of SREBP-2 and its target genes, further demonstrating that SREBP-2 pathway induction is not dependent on PPARα activation. Lastly, there is no activation of either SREBP-2 or ER stress pathways in kidney and lung of newborn Pex2(-/-) mice, suggesting a parallel induction of these pathways in peroxisome-deficient mice. These findings establish novel associations between SREBP-2, ER stress and PPARα pathway inductions.

  8. Panaxydol, a component of Panax ginseng, induces apoptosis in cancer cells through EGFR activation and ER stress and inhibits tumor growth in mouse models.

    PubMed

    Kim, Hee Suk; Lim, Jang Mi; Kim, Joo Young; Kim, Yongjin; Park, Serkin; Sohn, Jeongwon

    2016-03-15

    We reported previously that panaxydol, a component of Panax ginseng roots, induced mitochondria-mediated apoptosis preferentially in transformed cells. This study demonstrates that EGFR activation and the resulting ER stress mediate panaxydol-induced apoptosis, and that panaxydol suppresses in vivo tumor growth in syngeneic and xenogeneic mouse tumor models. In addition, we elucidated that CaMKII and TGF-β-activated kinase (TAK1) participate in p38/JNK activation by elevated cytoplasmic Ca(2+) concentration ([Ca(2+)]c). In MCF-7 cells, EGFR was activated immediately after exposure to panaxydol, and this activation was necessary for induction of apoptosis, suggesting that panaxydol might be a promising anticancer candidate, especially for EGFR-addicted cancer. Activation of PLCγ followed EGFR activation, resulting in Ca(2+) release from the endoplasmic reticulum (ER) via inositol triphosphate and ryanodine receptors. ER Ca(2+) release triggered mitochondrial Ca(2+) uptake indirectly through oxidative stress and ensuing ER stress. Elevated [Ca(2+)]c triggered sequential activation of calmodulin/CaMKII, TAK1 and p38/JNK. As shown previously, p38 and JNK activate NADPH oxidase. Here, it was shown that the resulting oxidative stress triggered ER stress. Among the three signaling branches of the unfolded protein response, protein kinase R-like ER kinase (PERK), but not inositol-requiring enzyme 1 or activating transcription factor 6, played a role in transmitting the apoptosis signal. PERK induced C/EBP homologous protein (CHOP), and CHOP elevated Bim expression, initiating mitochondrial Ca(2+) uptake and apoptosis. In summary, we identified roles of EGFR, the CAMKII-TAK1-p38/JNK pathway, and ER stress in panaxydol-induced apoptosis and demonstrated the in vivo anticancer effect of panaxydol.

  9. Panaxydol, a component of Panax ginseng, induces apoptosis in cancer cells through EGFR activation and ER stress and inhibits tumor growth in mouse models.

    PubMed

    Kim, Hee Suk; Lim, Jang Mi; Kim, Joo Young; Kim, Yongjin; Park, Serkin; Sohn, Jeongwon

    2016-03-15

    We reported previously that panaxydol, a component of Panax ginseng roots, induced mitochondria-mediated apoptosis preferentially in transformed cells. This study demonstrates that EGFR activation and the resulting ER stress mediate panaxydol-induced apoptosis, and that panaxydol suppresses in vivo tumor growth in syngeneic and xenogeneic mouse tumor models. In addition, we elucidated that CaMKII and TGF-β-activated kinase (TAK1) participate in p38/JNK activation by elevated cytoplasmic Ca(2+) concentration ([Ca(2+)]c). In MCF-7 cells, EGFR was activated immediately after exposure to panaxydol, and this activation was necessary for induction of apoptosis, suggesting that panaxydol might be a promising anticancer candidate, especially for EGFR-addicted cancer. Activation of PLCγ followed EGFR activation, resulting in Ca(2+) release from the endoplasmic reticulum (ER) via inositol triphosphate and ryanodine receptors. ER Ca(2+) release triggered mitochondrial Ca(2+) uptake indirectly through oxidative stress and ensuing ER stress. Elevated [Ca(2+)]c triggered sequential activation of calmodulin/CaMKII, TAK1 and p38/JNK. As shown previously, p38 and JNK activate NADPH oxidase. Here, it was shown that the resulting oxidative stress triggered ER stress. Among the three signaling branches of the unfolded protein response, protein kinase R-like ER kinase (PERK), but not inositol-requiring enzyme 1 or activating transcription factor 6, played a role in transmitting the apoptosis signal. PERK induced C/EBP homologous protein (CHOP), and CHOP elevated Bim expression, initiating mitochondrial Ca(2+) uptake and apoptosis. In summary, we identified roles of EGFR, the CAMKII-TAK1-p38/JNK pathway, and ER stress in panaxydol-induced apoptosis and demonstrated the in vivo anticancer effect of panaxydol. PMID:26421996

  10. 3,4-Dihydroxyphenylethanol alleviates early brain injury by modulating oxidative stress and Akt and nuclear factor-κB pathways in a rat model of subarachnoid hemorrhage

    PubMed Central

    FU, PENG; HU, QUAN

    2016-01-01

    3,4-Dihydroxyphenylethanol (DOPET) is a naturally occurring polyphenolic compound, present in olive oil and in the wastewater generated during olive oil processing. DOPET has various biological and pharmacological activities, including anticancer, antibacterial and anti-inflammatory effects. This study was designed to determine whether DOPET alleviates early brain injury (EBI) associated with subarachnoid hemorrhage (SAH) through suppression of oxidative stress and Akt and nuclear factor (NF)-κB pathways. Rats were randomly divided into the following groups: Sham group, SAH group, SAH + vehicle group and SAH + DOPET group. Mortality, blood-brain barrier (BBB) permeability and brain water content were assessed. Oxidative stress, Akt, NF-κB p65 and caspase-3 assays were also performed. DOPET induced a reduction in brain water content, and decreased the BBB permeability of SAH model rats. Furthermore, DOPET effectively controlled oxidative stress, NF-κB p65 and caspase-3 levels, in addition to significantly increasing Akt levels in the cortex following SAH. These results provide evidence that DOPET attenuates apoptosis in a rat SAH model through modulating oxidative stress and Akt and NF-κB signaling pathways. PMID:27168841

  11. Pomegranate extract decreases oxidative stress and alleviates mitochondrial impairment by activating AMPK-Nrf2 in hypothalamic paraventricular nucleus of spontaneously hypertensive rats

    PubMed Central

    Sun, Wenyan; Yan, Chunhong; Frost, Bess; Wang, Xin; Hou, Chen; Zeng, Mengqi; Gao, Hongli; Kang, Yuming; Liu, Jiankang

    2016-01-01

    High blood pressure, or “hypertension,” is associated with high levels of oxidative stress in the paraventricular nucleus of the hypothalamus. While pomegranate extract is a known antioxidant that is thought to have antihypertensive effects, the mechanism whereby pomegranate extract lowers blood pressure and the tissue that mediates its antihypertensive effects are currently unknown. We have used a spontaneously hypertensive rat model to investigate the antihypertensive properties of pomegranate extract. We found that chronic treatment of hypertensive rats with pomegranate extract significantly reduced blood pressure and cardiac hypertrophy. Furthermore, pomegranate extract reduced oxidative stress, increased the antioxidant defense system, and decreased inflammation in the paraventricular nucleus of hypertensive rats. We determined that pomegranate extract reduced mitochondrial superoxide anion levels and increased mitochondrial function in the paraventricular nucleus of hypertensive rats by promoting mitochondrial biogenesis and improving mitochondrial dynamics and clearance. We went on to identify the AMPK-nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) pathway as a mechanism whereby pomegranate extract reduces oxidative stress in the paraventricular nucleus to relieve hypertension. Our findings demonstrate that pomegranate extract alleviates hypertension by reducing oxidative stress and improving mitochondrial function in the paraventricular nucleus, and reveal multiple novel targets for therapeutic treatment of hypertension. PMID:27713551

  12. Elongation factor-1 alpha is a selective regulator of growth factor withdrawal and ER stress-induced apoptosis.

    PubMed

    Talapatra, S; Wagner, J D O; Thompson, C B

    2002-08-01

    To identify genes that contribute to apoptotic resistance, IL-3 dependent hematopoietic cells were transfected with a cDNA expression library and subjected to growth factor withdrawal. Transfected cells were enriched for survivors over two successive rounds of IL-3 withdrawal and reconstitution, resulting in the identification of a full-length elongation factor 1 alpha (EF-1alpha) cDNA. Ectopic EF-1alpha expression conferred protection from growth factor withdrawal and agents that induce endoplasmic reticulum stress, but not from nuclear damage or death receptor signaling. Overexpression of EF-1alpha did not lead to growth factor independent cell proliferation or global alterations in protein levels or rates of synthesis. These findings suggest that overexpression of EF-1alpha results in selective resistance to apoptosis induced by growth factor withdrawal and ER stress. PMID:12107828

  13. Inhibition of HSP90 by AUY922 Preferentially Kills Mutant KRAS Colon Cancer Cells by Activating Bim through ER Stress.

    PubMed

    Wang, Chun Yan; Guo, Su Tang; Wang, Jia Yu; Liu, Fen; Zhang, Yuan Yuan; Yari, Hamed; Yan, Xu Guang; Jin, Lei; Zhang, Xu Dong; Jiang, Chen Chen

    2016-03-01

    Oncogenic mutations of KRAS pose a great challenge in the treatment of colorectal cancer. Here we report that mutant KRAS colon cancer cells are nevertheless more susceptible to apoptosis induced by the HSP90 inhibitor AUY922 than those carrying wild-type KRAS. Although AUY922 inhibited HSP90 activity with comparable potency in colon cancer cells irrespective of their KRAS mutational statuses, those with mutant KRAS were markedly more sensitive to AUY922-induced apoptosis. This was associated with upregulation of the BH3-only proteins Bim, Bik, and PUMA. However, only Bim appeared essential, in that knockdown of Bim abolished, whereas knockdown of Bik or PUMA only moderately attenuated apoptosis induced by AUY922. Mechanistic investigations revealed that endoplasmic reticulum (ER) stress was responsible for AUY922-induced upregulation of Bim, which was inhibited by a chemical chaperone or overexpression of GRP78. Conversely, siRNA knockdown of GRP78 or XBP-1 enhanced AUY922-induced apoptosis. Remarkably, AUY922 inhibited the growth of mutant KRAS colon cancer xenografts through activation of Bim that was similarly associated with ER stress. Taken together, these results suggest that AUY922 is a promising drug in the treatment of mutant KRAS colon cancers, and the agents that enhance the apoptosis-inducing potential of Bim may be useful to improve the therapeutic efficacy.

  14. High-density lipoprotein inhibits ox-LDL-induced adipokine secretion by upregulating SR-BI expression and suppressing ER Stress pathway.

    PubMed

    Song, Guohua; Wu, Xia; Zhang, Pu; Yu, Yang; Yang, Mingfeng; Jiao, Peng; Wang, Ni; Song, Haiming; Wu, You; Zhang, Xiangjian; Liu, Huaxia; Qin, Shucun

    2016-01-01

    Endoplasmic reticulum stress (ERS) in adipocytes can modulate adipokines secretion. The aim of this study was to explore the protective effect of high-density lipoprotein (HDL) on oxidized low-density lipoprotein (ox-LDL)-induced ERS-C/EBP homologous protein (CHOP) pathway-mediated adipokine secretion. Our results showed that serum adipokines, including visfatin, resistin and TNF-α, correlated inversely with serum HDL cholesterol level in patients with abdominal obesity. In vitro, like ERS inhibitor 4-phenylbutyric acid (PBA), HDL inhibited ox-LDL- or tunicamycin (TM, an ERS inducer)-induced increase in visfatin and resistin secretion. Moreover, HDL inhibited ox-LDL-induced free cholesterol (FC) accumulation in whole cell lysate and in the endoplasmic reticulum. Additionally, like PBA, HDL inhibited ox-LDL- or TM-induced activation of ERS response as assessed by the decreased phosphorylation of protein kinase-like ER kinase and eukaryotic translation initiation factor 2α and reduced nuclear translocation of activating transcription factor 6 as well as the downregulation of Bip and CHOP. Furthermore, HDL increased scavenger receptor class B type I (SR-BI) expression and SR-BI siRNA treatment abolished the inhibitory effects of HDL on ox-LDL-induced FC accumulation and CHOP upregulation. These data indicate that HDL may suppress ox-LDL-induced FC accumulation in adipocytes through upregulation of SR-BI, subsequently preventing ox-LDL-induced ER stress-CHOP pathway-mediated adipocyte inflammation. PMID:27468698

  15. High-density lipoprotein inhibits ox-LDL-induced adipokine secretion by upregulating SR-BI expression and suppressing ER Stress pathway

    PubMed Central

    Song, Guohua; Wu, Xia; Zhang, Pu; Yu, Yang; Yang, Mingfeng; Jiao, Peng; Wang, Ni; Song, Haiming; Wu, You; Zhang, Xiangjian; Liu, Huaxia; Qin, Shucun

    2016-01-01

    Endoplasmic reticulum stress (ERS) in adipocytes can modulate adipokines secretion. The aim of this study was to explore the protective effect of high-density lipoprotein (HDL) on oxidized low-density lipoprotein (ox-LDL)-induced ERS-C/EBP homologous protein (CHOP) pathway-mediated adipokine secretion. Our results showed that serum adipokines, including visfatin, resistin and TNF-α, correlated inversely with serum HDL cholesterol level in patients with abdominal obesity. In vitro, like ERS inhibitor 4-phenylbutyric acid (PBA), HDL inhibited ox-LDL- or tunicamycin (TM, an ERS inducer)-induced increase in visfatin and resistin secretion. Moreover, HDL inhibited ox-LDL-induced free cholesterol (FC) accumulation in whole cell lysate and in the endoplasmic reticulum. Additionally, like PBA, HDL inhibited ox-LDL- or TM-induced activation of ERS response as assessed by the decreased phosphorylation of protein kinase-like ER kinase and eukaryotic translation initiation factor 2α and reduced nuclear translocation of activating transcription factor 6 as well as the downregulation of Bip and CHOP. Furthermore, HDL increased scavenger receptor class B type I (SR-BI) expression and SR-BI siRNA treatment abolished the inhibitory effects of HDL on ox-LDL-induced FC accumulation and CHOP upregulation. These data indicate that HDL may suppress ox-LDL-induced FC accumulation in adipocytes through upregulation of SR-BI, subsequently preventing ox-LDL-induced ER stress-CHOP pathway-mediated adipocyte inflammation. PMID:27468698

  16. Biweekly Maps of Wind Stress for the North Pacific from the ERS-1 Scatterometer

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The European Remote-sensing Satellite (ERS-1) was launched in July 1991 and contained several instruments for observing the Earth's ocean including a wind scatterometer. The scatterometer measurements were processed by the European Space Agency (ESA) and the Jet Propulsion Laboratory (JPL). JPL reprocessed (Freilich and Dunbar, 1992) the ERS-1 backscatter measurements to produced a 'value added' data set that contained the ESA wind vector as well as a set of up to four ambiguities. These ambiguities were further processed using a maximum-likelihood estimation (MLE) and a median filter to produce a 'selected vector.' This report describes a technique developed to produce time-averaged wind field estimates with their expected errors using only scatterometer wind vectors. The processing described in this report involved extracting regions of interest from the data tapes, checking the quality and creating the wind field estimate. This analysis also includes the derivation of biweekly average wind vectors over the North Pacific Ocean at a resolution of 0.50 x 0.50. This was done with an optimal average algorithm temporally and an over-determined biharmonic spline spatially. There have been other attempts at creating gridded wind files from ERS-1 winds, e.g., kriging techniques (Bentamy et al., 1996) and successive corrections schemes (Tang and Liu, 1996). There are several inherent problems with the ERS-1 scatterometer. Since this is a multidisciplinary mission, the satellite is flown in different orbits optimized for each phase of the mission. The scatterometer also shares several sub-systems with the Synthetic Aperture Radar (SAR) and cannot be operated while the SAR is in operation. The scatterometer is also a single-sided instrument and only measures backscatter along the right side of the satellite. The processing described here generates biweekly wind maps during the wktwo years analysis period regardless of the satellite orbit or missing data.

  17. Finger millet bran supplementation alleviates obesity-induced oxidative stress, inflammation and gut microbial derangements in high-fat diet-fed mice.

    PubMed

    Murtaza, Nida; Baboota, Ritesh K; Jagtap, Sneha; Singh, Dhirendra P; Khare, Pragyanshu; Sarma, Siddhartha M; Podili, Koteswaraiah; Alagesan, Subramanian; Chandra, T S; Bhutani, K K; Boparai, Ravneet K; Bishnoi, Mahendra; Kondepudi, Kanthi Kiran

    2014-11-14

    Several epidemiological studies have shown that the consumption of finger millet (FM) alleviates diabetes-related complications. In the present study, the effect of finger millet whole grain (FM-WG) and bran (FM-BR) supplementation was evaluated in high-fat diet-fed LACA mice for 12 weeks. Mice were divided into four groups: control group fed a normal diet (10 % fat as energy); a group fed a high-fat diet; a group fed the same high-fat diet supplemented with FM-BR; a group fed the same high-fat diet supplemented with FM-WG. The inclusion of FM-BR at 10 % (w/w) in a high-fat diet had more beneficial effects than that of FM-WG. FM-BR supplementation prevented body weight gain, improved lipid profile and anti-inflammatory status, alleviated oxidative stress, regulated the expression levels of several obesity-related genes, increased the abundance of beneficial gut bacteria (Lactobacillus, Bifidobacteria and Roseburia) and suppressed the abundance of Enterobacter in caecal contents (P≤ 0·05). In conclusion, FM-BR supplementation could be an effective strategy for preventing high-fat diet-induced changes and developing FM-BR-enriched functional foods.

  18. Alleviation of cadmium stress in Solanum lycopersicum L. by arbuscular mycorrhizal fungi via induction of acquired systemic tolerance.

    PubMed

    Hashem, Abeer; Abd Allah, E F; Alqarawi, A A; Al Huqail, Asma A; Egamberdieva, D; Wirth, S

    2016-03-01

    Experiments were conducted to evaluate cadmium (Cd) stress-induced changes in growth, antioxidants and lipid composition of Solanum lycopersicum with and without arbuscular mycorrhizal fungi (AMF). Cadmium stress (50 μM) caused significant changes in the growth and physio-biochemical attributes studied. AMF mitigated the deleterious impact of Cd on the parameters studied. Cadmium stress increased malonaldehyde and hydrogen peroxide production but AMF reduced these parameters by mitigating oxidative stress. The activity of antioxidant enzymes enhanced under Cd treatment and AMF inoculation further enhanced their activity, thus strengthening the plant's defense system. Proline and phenol content increased in Cd-treated as well as AMF-inoculated plants providing efficient protection against Cd stress. Cadmium treatment resulted in great alterations in the main lipid classes leading to a marked change in their composition. Cadmium stress caused a significant reduction in polyunsaturated fatty acids resulting in enhanced membrane leakage. The present study supports the use of AMF as a biological means to ameliorate Cd stress-induced changes in tomato. PMID:26981010

  19. Alleviation of cadmium stress in Solanum lycopersicum L. by arbuscular mycorrhizal fungi via induction of acquired systemic tolerance

    PubMed Central

    Hashem, Abeer; Abd_Allah, E.F.; Alqarawi, A.A.; Al Huqail, Asma A.; Egamberdieva, D.; Wirth, S.

    2015-01-01

    Experiments were conducted to evaluate cadmium (Cd) stress-induced changes in growth, antioxidants and lipid composition of Solanum lycopersicum with and without arbuscular mycorrhizal fungi (AMF). Cadmium stress (50 μM) caused significant changes in the growth and physio-biochemical attributes studied. AMF mitigated the deleterious impact of Cd on the parameters studied. Cadmium stress increased malonaldehyde and hydrogen peroxide production but AMF reduced these parameters by mitigating oxidative stress. The activity of antioxidant enzymes enhanced under Cd treatment and AMF inoculation further enhanced their activity, thus strengthening the plant’s defense system. Proline and phenol content increased in Cd-treated as well as AMF-inoculated plants providing efficient protection against Cd stress. Cadmium treatment resulted in great alterations in the main lipid classes leading to a marked change in their composition. Cadmium stress caused a significant reduction in polyunsaturated fatty acids resulting in enhanced membrane leakage. The present study supports the use of AMF as a biological means to ameliorate Cd stress-induced changes in tomato. PMID:26981010

  20. Growth performance and reproductive traits at first parity of New Zealand white female rabbits as affected by heat stress and its alleviation under Egyptian conditions.

    PubMed

    Marai, I F; Ayyat, M S; Abd el-Monem, U M

    2001-12-01

    Exposing growing and adult New Zealand White (NZW) female rabbits to severe heat stress (temperature-humidity index = 28.9) during summer adversely affected their growth and reproductive traits. The traits that declined significantly (p < 0.01) were the live body weight, daily weight gain and feed intake of growing rabbits, and the litter size and litter weight at weaning (p < 0.05) and the pre-weaning weight gain of pups (p < 0.01) for adult females. The conception rate declined considerably with heat stress. The declines in the values of the digestibility coefficients due to heat stress were 7.9% (p < 0.05) for dry matter (DM), 8.1% (p < 0.05) for crude protein (CP) and 1.0% for crude fibre (CF). The traits that increased significantly (p < 0.01) due to heat stress were water intake, water/feed ratio and rectal temperature in growing rabbits and pre-weaning mortality for adult females. Alleviation of heat stress in the growing and adult female NZW rabbits was more efficient with drinking cool water (10-15 degrees C; between 10:00 and 17:00) than with supplementation with palm oil (as a source of energy) or natural clay (as a natural enhancer to growth and milk production). Supplying the animals with cool drinking water gave the highest body weight and weight gain, conception rate, litter size and weight and digestibility coefficients for DM and CP and the lowest rectal temperature, respiration rate and pre-weaning mortality. The loss in rabbit production pertaining to heat stress estimated from the percentages of decline in conception rate x pre-weaning mortality x litter weight at weaning was 73.0%. The provision of cool water restored 11/12 of heat loss. PMID:11770200

  1. Stress alleviates reduced expression of cell adhesion molecules (NCAM, L1), and deficits in learning and corticosterone regulation of apolipoprotein E knockout mice.

    PubMed

    Grootendorst, J; Oitzl, M S; Dalm, S; Enthoven, L; Schachner, M; de Kloet, E R; Sandi, C

    2001-11-01

    Cell adhesion molecules (CAMs) involved in synaptic changes underlying learning and memory processes, are implicated in the effect of stress on behavioural performance. The present study was designed to test the hypothesis that (i) expression of CAMs is apolipoprotein E- (apoE) genotype dependent and (ii) repeated exposure to stress modulates the synthesis of CAMs in an apoE-genotype dependent manner. Using ELISA we tested this hypothesis and measured expression of NCAM and L1 in different brain regions of naïve and stressed apolipoprotein E-knockout (apoE0/0) and C57Bl6 (wild-type) mice. Naïve apoE0/0 mice had elevated basal morning corticosterone and ACTH concentrations and decreased expression of NCAM and L1 compared to wild-type mice. Repeated exposure of mice to rats, as the common stressor, alleviated the reduction in expression of CAMs in apoE0/0 mice; seven days after the last rat exposure, expression of NCAM was increased in frontal brain and hippocampus whereas expression of L1 was increased in hippocampus and cerebellum. Rat stress attenuated the elevation of basal morning corticosterone concentration in apoE0/0 mice towards concentrations detected in wild-type mice. Moreover, rat stress improved learning and memory of apoE0/0 mice in the water maze. In conclusion, repeated exposure to stress eliminated apoE-genotype-related differences in expression of CAMs. Under these same conditions the differences in cognitive performance and corticosterone concentrations were abolished between wild type and apoE0/0 mice.

  2. Salicylic Acid Alleviates the Adverse Effects of Salt Stress in Torreya grandis cv. Merrillii Seedlings by Activating Photosynthesis and Enhancing Antioxidant Systems

    PubMed Central

    Du, Xuhua; Tang, Hui; Shen, Chaohua; Wu, Jiasheng

    2014-01-01

    Background Salt stress is a major factor limiting plant growth and productivity. Salicylic acid (SA) has been shown to ameliorate the adverse effects of environmental stress on plants. To investigate the protective role of SA in ameliorating salt stress on Torreya grandis (T. grandis) trees, a pot experiment was conducted to analyze the biomass, relative water content (RWC), chlorophyll content, net photosynthesis (Pn), gas exchange parameters, relative leakage conductivity (REC), malondialdehyde (MDA) content, and activities of superoxide dismutase (SOD) and peroxidase (POD) of T. grandis under 0.2% and 0.4% NaCl conditions with and without SA. Methodology/Principal Findings The exposure of T. grandis seedlings to salt conditions resulted in reduced growth rates, which were associated with decreases in RWC and Pn and increases in REC and MDA content. The foliar application of SA effectively increased the chlorophyll (chl (a+b)) content, RWC, net CO2 assimilation rates (Pn), and proline content, enhanced the activities of SOD, CAT and POD, and minimized the increases in the REC and MDA content. These changes increased the capacity of T. grandis in acclimating to salt stress and thus increased the shoot and root dry matter. However, when the plants were under 0% and 0.2% NaCl stress, the dry mass of the shoots and roots did not differ significantly between SA-treated plants and control plants. Conclusions SA induced the salt tolerance and increased the biomass of T. grandis cv. by enhancing the chlorophyll content and activity of antioxidative enzymes, activating the photosynthetic process, and alleviating membrane injury. A better understanding about the effect of salt stress in T. grandis is vital, in order gain knowledge over expanding the plantations to various regions and also for the recovery of T. grandis species in the future. PMID:25302987

  3. Alleviation of Drought Stress and Metabolic Changes in Timothy (Phleum pratense L.) Colonized with Bacillus subtilis B26

    PubMed Central

    Gagné-Bourque, François; Bertrand, Annick; Claessens, Annie; Aliferis, Konstantinos A.; Jabaji, Suha

    2016-01-01

    Drought is a major limiting factor of crop productivity worldwide and its incidence is predicted to increase under climate change. Drought adaptation of cool-season grasses is thus a major challenge to secure the agricultural productivity under current and future climate conditions. Endophytes are non-pathogenic plant-associated bacteria that can play an important role in conferring resistance and improving plant tolerance to drought. In this study, the effect of inoculation of the bacterial endophyte Bacillus subtilis strain B26 on growth, water status, photosynthetic activity and metabolism of timothy (Phleum pratense L.) subjected to drought stress was investigated under controlled conditions. Under both drought-stress and non-stressed conditions, strain B26 successfully colonized the internal tissues of timothy and had a positive impact on plant growth. Exposure of inoculated plant to a 8-week drought-stress led to significant increase in shoot and root biomass by 26.6 and 63.8%, and in photosynthesis and stomatal conductance by 55.2 and 214.9% respectively, compared to non-inoculated plants grown under similar conditions. There was a significant effect of the endophyte on plant metabolism; higher levels of several sugars, notably sucrose and fructans and an increase of key amino acids such as, asparagine, glutamic acid and glutamine were recorded in shoots and roots of colonized plants compared to non-colonized ones. The accumulation of the non-protein amino acid GABA in shoots of stressed plants and in roots of stressed and unstressed plants was increased in the presence of the endophyte. Taken together, our results indicate that B. subtilis B26 improves timothy growth under drought stress through the modification of osmolyte accumulation in roots and shoots. These results will contribute to the development of a microbial agent to improve the yield of grass species including forage crops and cereals exposed to environmental stresses. PMID:27200057

  4. Histone hyperacetylation modulates spinal type II metabotropic glutamate receptor alleviating stress-induced visceral hypersensitivity in female rats

    PubMed Central

    Cao, Dong-Yuan; Bai, Guang; Ji, Yaping; Karpowicz, Jane

    2016-01-01

    Stress is often a trigger to exacerbate chronic pain including visceral hypersensitivity associated with irritable bowel syndrome, a female predominant functional bowel disorder. Epigenetic mechanisms that mediate stress responses are a potential target to interfere with visceral pain. The purpose of this study was to examine the effect of a histone deacetylase inhibitor, suberoylanilide hydroxamic acid, on visceral hypersensitivity induced by a subchronic stressor in female rats and to investigate the involvement of spinal glutamate receptors. Three daily sessions of forced swim induced visceral hypersensitivity. Intrathecal suberoylanilide hydroxamic acid prevented or reversed the stress-induced visceral hypersensitivity, increased spinal histone 3 acetylation and increased mGluR2 and mGluR3 expression. Chromatin immunoprecipitation (ChIP) analysis revealed enrichment of H3K9Ac and H3K18Ac at several promoter Grm2 and Grm3 regions. The mGluR2/3 antagonist LY341495 reversed the inhibitory effect of suberoylanilide hydroxamic acid on the stress-induced visceral hypersensitivity. In surprising contrast, stress and/or suberoylanilide hydroxamic acid had no effect on spinal NMDA receptor expression or function. These data reveal histone modification modulates mGluR2/3 expression in the spinal cord to attenuate stress-induced visceral hypersensitivity. HDAC inhibitors may provide a potential approach to relieve visceral hypersensitivity associated with irritable bowel syndrome. PMID:27385724

  5. Exposure of Jurkat cells to bis (tri-n-butyltin) oxide (TBTO) induces transcriptomics changes indicative for ER- and oxidative stress, T cell activation and apoptosis

    SciTech Connect

    Katika, Madhumohan R.; Hendriksen, Peter J.M.; Loveren, Henk van; Peijnenburg, Ad

    2011-08-01

    Tributyltin oxide (TBTO) is an organotin compound that is widely used as a biocide in agriculture and as an antifouling agent in paints. TBTO is toxic for many cell types, particularly immune cells. The present study aimed to identify the effects of TBTO on the human T lymphocyte cell line Jurkat. Cells were treated with 0.2 and 0.5 {mu}M TBTO for 3, 6, 12 and 24 h and then subjected to whole genome gene expression microarray analysis. The biological interpretation of the gene expression profiles revealed that endoplasmic reticulum (ER) stress is among the earliest effects of TBTO. Simultaneously or shortly thereafter, oxidative stress, activation of NFKB and NFAT, T cell activation, and apoptosis are induced. The effects of TBTO on genes involved in ER stress, NFAT pathway, T cell activation and apoptosis were confirmed by qRT-PCR. Activation and nuclear translocation of NFATC1 and the oxidative stress response proteins NRF2 and KEAP1 were confirmed by immunocytology. Taking advantage of previously published microarray data, we demonstrated that the induction of ER stress, oxidative stress, T cell activation and apoptosis by TBTO is not unique for Jurkat cells but does also occur in mouse thymocytes both ex vivo and in vivo and rat thymocytes ex vivo. We propose that the induction of ER stress leading to a T cell activation response is a major factor in the higher sensitivity of immune cells above other types of cells for TBTO. - Research Highlights: > The human T lymphocyte cell line Jurkat was exposed to TBTO. > Whole-genome microarray experiments were performed. > Data analysis revealed the induction of ER stress and activation of NFAT and NFKB. > Exposure to TBTO also led to T cell activation, oxidative stress and apoptosis.

  6. Antioxidant potential of Cymbopogon citratus extract: alleviation of carbon tetrachloride-induced hepatic oxidative stress and toxicity.

    PubMed

    Koh, Pei Hoon; Mokhtar, Ruzaidi Azli Mohd; Iqbal, Mohammad

    2012-01-01

    This study was aimed to evaluate the effect of Cymbopogon citratus against carbon tetrachloride (CCl(4))-mediated hepatic oxidative damage in rats. Rats were administrated with C. citratus extract (100, 200 and 300 mg/kg b.w.) for 14 days before the challenge of CCl(4) (1.2 ml/kg b.w. p.o) on 13th and 14th days. Hepatic damage was evaluated by employing serum biochemical parameters (alanine aminotransferase-ALT, aspartate aminotransferase-AST and lactate dehydrogenase-LDH), malondialdehye (MDA) level, reduced GSH and antioxidant enzymes (catalase: CAT, glutathione peroxidase: GPX, quinone reductase: QR, glutathione S-transferase: GST, glutathione reductase: GR, glucose-6-phosphate dehyrogenase: G6PD). In addition, CCl(4)-mediated hepatic damage was further evaluated by histopathological examination. However, most of these changes were alleviated by prophylactic treatment of animals with C. citratus dose dependently (p < 0.05). The protection was further evident through decreased histopathological alterations in liver. The results of the present study indicated that the hepatoprotective effect of C. citratus might be ascribable to its antioxidant and free radical scavenging property.

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

    PubMed Central

    Saito, Ayako; Suga, Kei; Ono-Nakagawa, Risa; Sanada, Masumi; Akagawa, Kimio

    2015-01-01

    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]. PMID:26759824

  8. Cristacarpin promotes ER stress-mediated ROS generation leading to premature senescence by activation of p21(waf-1).

    PubMed

    Chakraborty, Souneek; Rasool, Reyaz Ur; Kumar, Sunil; Nayak, Debasis; Rah, Bilal; Katoch, Archana; Amin, Hina; Ali, Asif; Goswami, Anindya

    2016-06-01

    Stress-induced premature senescence (SIPS) is quite similar to replicative senescence that is committed by cells exposed to various stress conditions viz. ultraviolet radiation (DNA damage), hydrogen peroxide (oxidative stress), chemotherapeutic agents (cytotoxic threat), etc. Here, we report that cristacarpin, a natural product obtained from the stem bark of Erythrina suberosa, promotes endoplasmic reticulum (ER) stress, leading to sub-lethal reactive oxygen species (ROS) generation and which eventually terminates by triggering senescence in pancreatic and breast cancer cells through blocking the cell cycle in the G1 phase. The majority of cristacarpin-treated cells responded to conventional SA-β-gal stains; showed characteristic p21(waf1) upregulation along with enlarged and flattened morphology; and increased volume, granularity, and formation of heterochromatin foci-all of these features are the hallmarks of senescence. Inhibition of ROS generation by N-acetyl-L-cysteine (NAC) significantly reduced the expression of p21(waf1), confirming that the modulation in p21(waf1) by anti-proliferative cristacarpin was ROS dependent. Further, the elevation in p21(waf1) expression in PANC-1 and MCF-7 cells was consistent with the decrease in the expression of Cdk-2 and cyclinD1. Here, we provide evidence that cristacarpin promotes senescence in a p53-independent manner. Moreover, cristacarpin treatment induced p38MAPK, indicating the ROS-dependent activation of the MAP kinase pathway, and thus abrogates the tumor growth in mouse allograft tumor model.

  9. Cellular cholesterol accumulation modulates high fat high sucrose (HFHS) diet-induced ER stress and hepatic inflammasome activation in the development of non-alcoholic steatohepatitis.

    PubMed

    Bashiri, Amir; Nesan, Dinushan; Tavallaee, Ghazaleh; Sue-Chue-Lam, Ian; Chien, Kevin; Maguire, Graham F; Naples, Mark; Zhang, Jing; Magomedova, Lilia; Adeli, Khosrow; Cummins, Carolyn L; Ng, Dominic S

    2016-07-01

    Non-alcoholic steatohepatitis (NASH), is the form of non-alcoholic fatty liver disease posing risk to progress into serious long term complications. Human and pre-clinical models implicate cellular cholesterol dysregulation playing important role in its development. Mouse model studies suggest synergism between dietary cholesterol and fat in contributing to NASH but the mechanisms remain poorly understood. Our laboratory previously reported the primary importance of hepatic endoplasmic reticulum cholesterol (ER-Chol) in regulating hepatic ER stress by comparing the responses of wild type, Ldlr-/-xLcat+/+ and Ldlr-/-xLcat-/- mice, to a 2% high cholesterol diet (HCD). Here we further investigated the roles of ER-Chol and ER stress in HFHS diet-induced NASH using the same strains. With HFHS diet feeding, both WT and Ldlr-/-xLcat+/+ accumulate ER-Chol in association with ER stress and inflammasome activation but the Ldlr-/-xLcat-/- mice are protected. By contrast, all three strains accumulate cholesterol crystal, in correlation with ER-Chol, albeit less so in Ldlr-/-xLcat-/- mice. By comparison, HCD feeding per se (i) is sufficient to promote steatosis and activate inflammasomes, and (ii) results in dramatic accumulation of cholesterol crystal which is linked to inflammasome activation in Ldlr-/-xLcat-/- mice, independent of ER-Chol. Our data suggest that both dietary fat and cholesterol each independently promote steatosis, cholesterol crystal accumulation and inflammasome activation through distinct but complementary pathways. In vitro studies using palmitate-induced hepatic steatosis in HepG2 cells confirm the key roles by cellular cholesterol in the induction of steatosis and inflammasome activations. These novel findings provide opportunities for exploring a cellular cholesterol-focused strategy for treatment of NASH. PMID:27090939

  10. EXPRESS: Histone hyperacetylation modulates spinal type II metabotropic glutamate receptor alleviating stress-induced visceral hypersensitivity in female rats.

    PubMed

    Cao, Dong-Yuan; Bai, Guang; Ji, Yaping; Karpowicz, Jane M; Traub, Richard J

    2016-01-01

    Stress is often a trigger to exacerbate chronic pain including visceral hypersensitivity associated with irritable bowel syndrome, a female predominant functional bowel disorder. Epigenetic mechanisms that mediate stress responses are a potential target to interfere with visceral pain. The purpose of this study was to examine the effect of a histone deacetylase inhibitor, suberoylanilide hydroxamic acid, on visceral hypersensitivity induced by a subchronic stressor in female rats and to investigate the involvement of spinal glutamate receptors. Three daily sessions of forced swim induced visceral hypersensitivity. Intrathecal suberoylanilide hydroxamic acid prevented or reversed the stress-induced visceral hypersensitivity, increased spinal histone 3 acetylation and increased mGluR2 and mGluR3 expression. Chromatin immunoprecipitation (ChIP) analysis revealed enrichment of H3K9Ac and H3K18Ac at several promoter Grm2 and Grm3 regions. The mGluR2/3 antagonist LY341495 reversed the inhibitory effect of suberoylanilide hydroxamic acid on the stress-induced visceral hypersensitivity. In surprising contrast, stress and/or suberoylanilide hydroxamic acid had no effect on spinal NMDA receptor expression or function. These data reveal histone modification modulates mGluR2/3 expression in the spinal cord to attenuate stressinduced visceral hypersensitivity. HDAC inhibitors may provide a potential approach to relieve visceral hypersensitivity associated with irritable bowel syndrome. PMID:27385724

  11. Silicon alleviates drought stress of rice plants by improving plant water status, photosynthesis and mineral nutrient absorption.

    PubMed

    Chen, Wei; Yao, Xiaoqin; Cai, Kunzheng; Chen, Jining

    2011-07-01

    Drought is a major constraint for rice production in the rainfed lowlands in China. Silicon (Si) has been verified to play an important role in enhancing plant resistance to environmental stress. Two near-isogenic lines of rice (Oryza sativa L.), w-14 (drought susceptible) and w-20 (drought resistant), were selected to study the effects of exogenous Si application on the physiological traits and nutritional status of rice under drought stress. In wet conditions, Si supply had no effects on growth and physiological parameters of rice plants. Drought stress was found to reduce dry weight, root traits, water potential, photosynthetic parameters, basal quantum yield (F(v)/F(0)), and maximum quantum efficiency of PSII photochemistry (F(v)/F(m)) in rice plants, while Si application significantly increased photosynthetic rate (Pr), transpiration rate (Tr), F(v)/F(0), and F(v)/F(m) of rice plants under drought stress. In addition, water stress increased K, Na, Ca, Mg, Fe content of rice plants, but Si treatment significantly reduced these nutrient level. These results suggested that silicon application was useful to increase drought resistance of rice through the enhancement of photochemical efficiency and adjustment of the mineral nutrient absorption in rice plants.

  12. Nicotinamide ameliorates palmitate-induced ER stress in hepatocytes via cAMP/PKA/CREB pathway-dependent Sirt1 upregulation.

    PubMed

    Li, Jiaxin; Dou, Xiaobing; Li, Songtao; Zhang, Ximei; Zeng, Yong; Song, Zhenyuan

    2015-11-01

    Nicotinamide (NAM) is the amide of nicotinic acid and a predominant precursor for NAD(+) biosynthesis via the salvage pathway. Sirt1 is a NAD(+)-dependent deacetylase, playing an important role in regulating cellular functions. Although hepatoprotective effect of NAM has been reported, the underlying mechanism remains elusive. ER stress, induced by saturated fatty acids, in specific palmitate, plays a pathological role in the development of nonalcoholic fatty liver disease. This study aims to determine the effect of NAM on palmitate-induced ER stress in hepatocytes and to elucidate molecular mechanisms behind. Both HepG2 cells and primary mouse hepatocytes were exposed to palmitate (conjugated to BSA at a 2:1 M ratio), NAM, or their combination for different durations. Cellular NAD(+) level, Sirt1 expression/activity, ER stress, as well as cAMP/PKA/CREB pathway activation were determined. NAM increased Sirt1 expression and enzymatic activity, which contributes to the ameliorative effect of NAM on palmitate-triggered ER stress. NAM increased intracellular NAD(+) level in hepatocytes, however, blocking the salvage pathway, a pathway for NAD(+) synthesis from NAM, only partially prevented NAM-induced Sirt1 upregulation while completely prevented NAD+ increase in response to NAM. Further mechanistic investigations revealed that NAM elevated intracellular cAMP level via suppressing PDE activity, leading to downstream PKA and CREB activation. Importantly, cAMP/PKA/CREB pathway blockade abolished not only NAM-induced Sirt1 upregulation, but also its protective effect against ER stress. Our results demonstrate that NAM protects hepatocytes against palmitate-induced ER stress in hepatocytes via upregulating Sirt1. Activation of the cAMP/PKA/CREB pathway plays a key role in NAM-induced Sirt1 upregulation. PMID:26352206

  13. Treadmill exercise alleviates prenatal noise stress-induced impairment of spatial learning ability through enhancing hippocampal neurogenesis in rat pups.

    PubMed

    Kim, Tae-Woon; Shin, Mal-Soon; Park, Joon-Ki; Shin, Mi-Ai; Lee, Hee-Hyuk; Lee, Sam-Jun

    2013-01-01

    Stress alters brain cell properties and then disturbs cognitive processes, such as learning and memory. In this study, we investigated the effect of postnatal treadmill exercise on hippocampal neurogenesis and spatial learning ability of rat pups following prenatal noise stress. The impact of exercise intensity (mild-intensity exercise vs heavy-intensity exercise) was also compared. The pregnant rats in the stress-applied group were exposed to a 95 dB supersonic machine sound for 1 h once a day from the 15th day after mating until delivery. After birth, the rat pups in the exercise groups were made to run on a treadmill for 30 min once a day for 7 consecutive days, starting 4 weeks after birth. The spatial learning ability was tested using radial-arm maze task and hippocampal neurogenesis was determined by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. The rat pups born from the stress-applied maternal rats spent more time for the seeking of water and showed higher number of error in the radial-arm maze task compared to the control group. These rat pups showed suppressed neurogenesis in the hippocampus. In contrast, the rat pups performed postnatal treadmill exercise saved time for seeking of water and showed lower number of error compared to the stress-applied group. Postnatal treadmill exercise also enhanced neurogenesis in the hippocampus. The mild-intensity exercise showed more potent impact compared to the heavy-intensity exercise. The present results reveal that postnatal treadmill exercise lessens prenatal stress-induced deterioration of brain function in offspring.

  14. Pre-anthesis high-temperature acclimation alleviates damage to the flag leaf caused by post-anthesis heat stress in wheat.

    PubMed

    Wang, Xiao; Cai, Jian; Jiang, Dong; Liu, Fulai; Dai, Tingbo; Cao, Weixing

    2011-04-15

    The objective of this study was to investigate the effect of pre-anthesis high-temperature acclimation on leaf physiology of winter wheat in response to post-anthesis heat stress. The results showed that both pre- and post-anthesis heat stresses significantly depressed flag leaf photosynthesis and enhanced cell membrane peroxidation, as exemplified by increased O₂⁻(·) production rate and reduction in activities of antioxiditave enzymes. However, under post-anthesis heat stress, plants with pre-anthesis high-temperature acclimation (HH) showed much higher photosynthetic rates than those without pre-anthesis high-temperature acclimation (CH). Leaves of HH plants exhibited a higher Chl a/b ratio and lower chlorophyll/carotenoid ratio and superoxide anion radical release rate compared with those of the CH plants. In addition, antioxidant enzyme activities in HH plants were significantly higher than in CH. Coincidently, expressions of photosythesis-responsive gene encoding Rubisco activase B (RcaB) and antioxidant enzyme-related genes encoding mitochondrial manganese superoxide dismutase (Mn-SOD), chloroplastic Cu/Zn superoxide dismutase (Cu/Zn-SOD), catalase (CAT) and cytosolic glutathione reductase (GR) were all up-regulated under HH, whereas a gene encoding a major chlorophyll a/b-binding protein (Cab) was up-regulated by post-anthesis heat stress at 10 DAA, but was down-regulated at 13 DAA. The changes in the expression levels of the HH plants were more pronounced than those for the CH. Collectively, the results indicated that pre-anthesis high-temperature acclimation could effectively alleviate the photosynthetic and oxidative damage caused by post-anthesis heat stress in wheat flag leaves, which was partially attributable to modifications in the expression of the photosythesis-responsive and antioxidant enzymes-related genes.

  15. The novel white spot syndrome virus-induced gene, PmERP15, encodes an ER stress-responsive protein in black tiger shrimp, Penaeus monodon.

    PubMed

    Leu, Jiann-Horng; Liu, Kuan-Fu; Chen, Kuan-Yu; Chen, Shu-Hwa; Wang, Yu-Bin; Lin, Chung-Yen; Lo, Chu-Fang

    2015-04-01

    By microarray screening, we identified a white spot syndrome virus (WSSV)-strongly induced novel gene in gills of Penaeus monodon. The gene, PmERP15, encodes a putative transmembrane protein of 15 kDa, which only showed some degree of similarity (54-59%) to several unknown insect proteins, but had no hits to shrimp proteins. RT-PCR showed that PmERP15 was highly expressed in the hemocytes, heart and lymphoid organs, and that WSSV-induced strong expression of PmERP15 was evident in all tissues examined. Western blot analysis likewise showed that WSSV strongly up-regulated PmERP15 protein levels. In WSSV-infected hemocytes, immunofluorescence staining showed that PmERP15 protein was colocalized with an ER enzyme, protein disulfide isomerase, and in Sf9 insect cells, PmERP15-EGFP fusion protein colocalized with ER -Tracker™ Red dye as well. GRP78, an ER stress marker, was found to be up-regulated in WSSV-infected P. monodon, and both PmERP15 and GRP78 were up-regulated in shrimp injected with ER stress inducers tunicamycin and dithiothreitol. Silencing experiments showed that although PmERP15 dsRNA-injected shrimp succumbed to WSSV infection more rapidly, the WSSV copy number had no significant changes. These results suggest that PmERP15 is an ER stress-induced, ER resident protein, and its induction in WSSV-infected shrimp is caused by the ER stress triggered by WSSV infection. Furthermore, although PmERP15 has no role in WSSV multiplication, its presence is essential for the survival of WSSV-infected shrimp.

  16. The novel white spot syndrome virus-induced gene, PmERP15, encodes an ER stress-responsive protein in black tiger shrimp, Penaeus monodon.

    PubMed

    Leu, Jiann-Horng; Liu, Kuan-Fu; Chen, Kuan-Yu; Chen, Shu-Hwa; Wang, Yu-Bin; Lin, Chung-Yen; Lo, Chu-Fang

    2015-04-01

    By microarray screening, we identified a white spot syndrome virus (WSSV)-strongly induced novel gene in gills of Penaeus monodon. The gene, PmERP15, encodes a putative transmembrane protein of 15 kDa, which only showed some degree of similarity (54-59%) to several unknown insect proteins, but had no hits to shrimp proteins. RT-PCR showed that PmERP15 was highly expressed in the hemocytes, heart and lymphoid organs, and that WSSV-induced strong expression of PmERP15 was evident in all tissues examined. Western blot analysis likewise showed that WSSV strongly up-regulated PmERP15 protein levels. In WSSV-infected hemocytes, immunofluorescence staining showed that PmERP15 protein was colocalized with an ER enzyme, protein disulfide isomerase, and in Sf9 insect cells, PmERP15-EGFP fusion protein colocalized with ER -Tracker™ Red dye as well. GRP78, an ER stress marker, was found to be up-regulated in WSSV-infected P. monodon, and both PmERP15 and GRP78 were up-regulated in shrimp injected with ER stress inducers tunicamycin and dithiothreitol. Silencing experiments showed that although PmERP15 dsRNA-injected shrimp succumbed to WSSV infection more rapidly, the WSSV copy number had no significant changes. These results suggest that PmERP15 is an ER stress-induced, ER resident protein, and its induction in WSSV-infected shrimp is caused by the ER stress triggered by WSSV infection. Furthermore, although PmERP15 has no role in WSSV multiplication, its presence is essential for the survival of WSSV-infected shrimp. PMID:25499032

  17. Nuclear versus cytosolic activity of the yeast Hog1 MAP kinase in response to osmotic and tunicamycin-induced ER stress.

    PubMed

    García-Marqués, Sara; Randez-Gil, Francisca; Prieto, Jose A

    2015-07-22

    We examined the physiological significance of the nuclear versus cytosolic localization of the MAPK Hog1p in the ability of yeast cells to cope with osmotic and ER (endoplasmic reticulum) stress. Our results indicate that nuclear import of Hog1p is not critical for osmoadaptation. Plasma membrane-anchored Hog1p is still able to induce increased expression of GPD1 and glycerol accumulation. This is a key osmoregulatory event, although a small production of the osmolyte coupled with the nuclear import of Hog1p is sufficient to provide osmoresistance. On the contrary, the nuclear activity of Hog1p is dispensable for ER stress adaptation.

  18. Tolerance response to in situ ammonia stress in a pilot-scale anaerobic digestion reactor for alleviating ammonia inhibition.

    PubMed

    Gao, Shumei; Zhao, Mingxing; Chen, Yang; Yu, Meijuan; Ruan, Wenquan

    2015-12-01

    The anaerobic digestion (AD) of protein-rich substrates is generally inhibited by ammonia. In this study, ammonia-tolerant acclimation was exposed to a stepwise in situ ammonia stress during the continuous AD of solid residual kitchen waste by using a continuous stirred tank reactor with a 50 L active volume. The reactor worked well during the acclimation process, with an average daily biogas production of 58 L/d, an effluent soluble chemical oxygen demand of 7238 mg/L, a volatile fatty acid (VFA) content of 578 mg/L, and a VFA/alkalinity ratio of less than 0.4. Moreover, ammonia stress enhanced the activity of Coenzyme F420. The results of high-throughput 16S rDNA sequencing showed that ammonia stress increased the relative abundance of Firmicutes bacteria and hydrogenotrophic methanogens but decreased the abundance of acetotrophic methanogens. This microbial community shift was proposed to be an in situ response strategy for ammonia stress adaptation.

  19. Cinnamon intake alleviates the combined effects of dietary-induced insulin resistance and acute stress on brain mitochondria.

    PubMed

    Couturier, Karine; Hininger, Isabelle; Poulet, Laurent; Anderson, Richard A; Roussel, Anne-Marie; Canini, Frédéric; Batandier, Cécile

    2016-02-01

    Insulin resistance (IR), which is a leading cause of the metabolic syndrome, results in early brain function alterations which may alter brain mitochondrial functioning. Previously, we demonstrated that rats fed a control diet and submitted to an acute restraint stress exhibited a delayed mitochondrial permeability transition pore (mPTP) opening. In this study, we evaluated the combined effects of dietary and emotional stressors as found in western way of life. We studied, in rats submitted or not to an acute stress, the effects of diet-induced IR on brain mitochondria, using a high fat/high fructose diet (HF(2)), as an IR inducer, with addition or not of cinnamon as an insulin sensitizer. We measured Ca(2+) retention capacity, respiration, ROS production, enzymatic activities and cell signaling activation. Under stress, HF(2) diet dramatically decreased the amount of Ca(2+) required to open the mPTP (13%) suggesting an adverse effect on mitochondrial survival. Cinnamon added to the diet corrected this negative effect and resulted in a partial recovery (30%). The effects related to cinnamon addition to the diet could be due to its antioxidant properties or to the observed modulation of PI3K-AKT-GSK3β and MAPK-P38 pathways or to a combination of both. These data suggest a protective effect of cinnamon on brain mitochondria against the negative impact of an HF(2) diet. Cinnamon could be beneficial to counteract deleterious dietary effects in stressed conditions. PMID:26878796

  20. Resolvin D1 reduces ER stress-induced apoptosis and triglyceride accumulation through JNK pathway in HepG2 cells.

    PubMed

    Jung, Tae Woo; Hwang, Hwan-Jin; Hong, Ho Cheol; Choi, Hae Yoon; Yoo, Hye Jin; Baik, Sei Hyun; Choi, Kyung Mook

    2014-06-25

    Research has indicated that stress on the endoplasmic reticulum (ER) of a cell affects the pathogenesis of metabolic disorders such as obesity, type 2 diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD). Resolvins, a novel family derived from ω-3 polyunsaturated fatty acids, have anti-inflammatory and insulin sensitizing properties, and it has been suggested that they play a role in the amelioration of obesity-related metabolic dysfunctions. This study showed that pretreatment with resolvin D1 (RvD1) attenuated ER stress-induced apoptosis and also decreased caspase 3 activity in HepG2 cells. Furthermore, RvD1 significantly decreased tunicamycin-induced triglycerides accumulation as well as SREBP-1 expression. However, tunicamycin-induced ER stress markers were not significantly affected by RvD1 treatment. Moreover, RvD1 treatment did not affect the tunicamycin-induced expression of chaperones that assist protein folding in the ER. These results suggest that RvD1-conferred cellular protection may occur downstream of the ER stress. This was supported by the finding that RvD1 significantly inhibited tunicamycin-induced c-Jun N-terminal kinase (JNK) expression, although P38 and ERK1/2 phosphorylation were not affected. In addition, anisomycin, a JNK activator, increased caspase 3 activity and apoptosis as well as triglycerides accumulation and SREBP1 expression, and RvD1 treatment reversed these changes. In conclusion, RvD1 attenuated ER stress-induced hepatic steatosis and apoptosis via the JNK-mediated pathway. This study may provide insight into a novel underlying mechanism and a strategy for treating NAFLD. PMID:24784707

  1. Prostaglandin EP2 receptor signaling protects human trabecular meshwork cells from apoptosis induced by ER stress through down-regulation of p53.

    PubMed

    Kalouche, Georges; Boucher, Céline; Coste, Annick; Debussche, Laurent; Orsini, Cécile; Baudouin, Christophe; Debeir, Thomas; Vigé, Xavier; Rostène, William

    2016-09-01

    E-prostanoid receptor subtype 2 (EP2) agonists are currently under clinical development as hypotensive agents for the treatment of ocular hypertension. However, the effects of EP2 receptor agonists on trabecular meshwork (TM) alterations leading to primary open-angle glaucoma (POAG) are still unknown. Here, we evaluated whether EP2 receptor activation exhibits protective functions on TM cell death induced by endoplasmic reticulum (ER) stress. We show that the EP2 receptor agonist butaprost protects TM cell death mediated by the ER stress inducer tunicamycin through a cyclic AMP (cAMP)-dependent mechanism, but independent of the classical cAMP sensors, protein kinase A and exchange proteins activated by cAMP. The ER stress-induced intrinsic apoptosis inhibited by the EP2 receptor agonist was correlated with a decreased accumulation of the cellular stress sensor p53. In addition, p53 down-regulation was associated with inhibition of its transcriptional activity, which led to decreased expression of the pro-apoptotic p53-upregulated modulator of apoptosis (PUMA). The stabilization of p53 by nutlin-3a abolished butaprost-mediated cell death protection. In conclusion, we showed that EP2 receptor activation protects against ER stress-dependent mitochondrial apoptosis through down-regulation of p53. The specific inhibition of this pathway could reduce TM alterations observed in POAG patients. PMID:27321910

  2. The Edible Marine Alga Gracilariopsis chorda Alleviates Hypoxia/Reoxygenation-Induced Oxidative Stress in Cultured Hippocampal Neurons

    PubMed Central

    Mohibbullah, Md.; Hannan, Md. Abdul; Choi, Ji-Young; Bhuiyan, Mohammad Maqueshudul Haque; Hong, Yong-Ki; Choi, Jae-Suk; Choi, In Soon; Moon, Il Soo

    2015-01-01

    Abstract Age-related neurological disorders are of growing concern among the elderly, and natural products with neuroprotective properties have been attracting increasing attention as candidates for the prevention or treatment of neurological disorders induced by oxidative stress. In an effort to explore natural resources, we collected some common marine seaweed from the Korean peninsula and Indonesia and screened them for neuroprotective activity against hypoxia/reoxygenation (H/R)-induced oxidative stress. Of the 23 seaweeds examined, the ethanol extract of Gracilariopsis chorda (GCE) provided maximum neuroprotection at an optimum concentration of 15 μg/mL, followed by Undaria pinnatifida. GCE increased cell viability after H/R, decreased the formation of reactive oxygen species (measured by 2′,7′-dichlorodihydrofluorescein diacetate [DCF-DA] staining), and inhibited the double-stranded DNA breaks (measured by H2AX immunocytochemistry), apoptosis (measured by Annexin V/propidium iodide staining), internucleosomal DNA fragmentation (measured by DNA laddering), and dissipation of mitochondrial membrane potential (measured by JC-1 staining). Using reverse-phase high-pressure liquid chromatography, we quantitated the arachidonic acid (AA) in GCE, which provides neuroprotection against H/R-induced oxidative stress. This neuroprotective effect of AA was comparable to that of GCE. These findings suggest that the neuroprotective effect of GCE against H/R-induced neuronal death is due, at least in part, to the AA content that suppresses neuronal apoptosis. PMID:26106876

  3. The Edible Marine Alga Gracilariopsis chorda Alleviates Hypoxia/Reoxygenation-Induced Oxidative Stress in Cultured Hippocampal Neurons.

    PubMed

    Mohibbullah, Md; Hannan, Md Abdul; Choi, Ji-Young; Bhuiyan, Mohammad Maqueshudul Haque; Hong, Yong-Ki; Choi, Jae-Suk; Choi, In Soon; Moon, Il Soo

    2015-09-01

    Age-related neurological disorders are of growing concern among the elderly, and natural products with neuroprotective properties have been attracting increasing attention as candidates for the prevention or treatment of neurological disorders induced by oxidative stress. In an effort to explore natural resources, we collected some common marine seaweed from the Korean peninsula and Indonesia and screened them for neuroprotective activity against hypoxia/reoxygenation (H/R)-induced oxidative stress. Of the 23 seaweeds examined, the ethanol extract of Gracilariopsis chorda (GCE) provided maximum neuroprotection at an optimum concentration of 15 μg/mL, followed by Undaria pinnatifida. GCE increased cell viability after H/R, decreased the formation of reactive oxygen species (measured by 2',7'-dichlorodihydrofluorescein diacetate [DCF-DA] staining), and inhibited the double-stranded DNA breaks (measured by H2AX immunocytochemistry), apoptosis (measured by Annexin V/propidium iodide staining), internucleosomal DNA fragmentation (measured by DNA laddering), and dissipation of mitochondrial membrane potential (measured by JC-1 staining). Using reverse-phase high-pressure liquid chromatography, we quantitated the arachidonic acid (AA) in GCE, which provides neuroprotection against H/R-induced oxidative stress. This neuroprotective effect of AA was comparable to that of GCE. These findings suggest that the neuroprotective effect of GCE against H/R-induced neuronal death is due, at least in part, to the AA content that suppresses neuronal apoptosis.

  4. Honokiol confers immunogenicity by dictating calreticulin exposure, activating ER stress and inhibiting epithelial-to-mesenchymal transition.

    PubMed

    Liu, Shing-Hwa; Lee, Wen-Jane; Lai, De-Wei; Wu, Sheng-Mao; Liu, Chia-Yu; Tien, Hsing-Ru; Chiu, Chien-Shan; Peng, Yen-Chun; Jan, Yee-Jee; Chao, Te-Hsin; Pan, Hung-Chuan; Sheu, Meei-Ling

    2015-04-01

    Peritoneal dissemination is a major clinical obstacle in gastrointestinal cancer therapy, and it accounts for the majority of cancer-related mortality. Calreticulin (CRT) is over-expressed in gastric tumors and has been linked to poor prognosis. In this study, immunohistochemistry studies revealed that the up-regulation of CRT was associated with lymph node and distant metastasis in patients with gastric cancer specimens. CRT was significantly down-regulated in highly metastatic gastric cancer cell lines and metastatic animal by Honokiol-treated. Small RNA interference blocking CRT by siRNA-CRT was translocated to the cells in the early immunogenic response to Honokiol. Honokiol activated endoplasmic reticulum (ER) stress and down-regulated peroxisome proliferator-activated receptor-γ (PPARγ) activity resulting in PPARγ and CRT degradation through calpain-II activity, which could be reversed by siRNA-calpain-II. The Calpain-II/PPARγ/CRT axis and interaction evoked by Honokiol could be blocked by gene silencing or pharmacological agents. Both transforming growth factor (TGF)-β1 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced cell migration, invasion and reciprocal down-regulation of epithelial marker E-cadherin, which could be abrogated by siRNA-CRT. Moreover, Honokiol significantly suppressed MNNG-induced gastrointestinal tumor growth and over-expression of CRT in mice. Knockdown CRT in gastric cancer cells was found to effectively reduce growth ability and metastasis in vivo. The present study provides insight into the specific biological behavior of CRT in epithelial-to-mesenchymal transition (EMT) and metastasis. Taken together, our results suggest that the therapeutic inhibition of CRT by Honokiol suppresses both gastric tumor growth and peritoneal dissemination by dictating early translocation of CRT in immunogenic cell death, activating ER stress, and blocking EMT. PMID:25619450

  5. Gene Expression and MicroRNA Expression Analysis in Small Arteries of Spontaneously Hypertensive Rats. Evidence for ER Stress.

    PubMed

    Palao, Teresa; Swärd, Karl; Jongejan, Aldo; Moerland, Perry D; de Vos, Judith; van Weert, Angela; Arribas, Silvia M; Groma, Gergely; vanBavel, Ed; Bakker, Erik N T P

    2015-01-01

    Small arteries are known to develop functional and structural alterations in hypertension. However, the mechanisms of this remodeling are not fully understood. We hypothesized that altered gene expression is associated with the development of hypertension in mesenteric arteries of spontaneously hypertensive rats (SHR). Three sublines of SHR and normotensive Wistar Kyoto rats (WKY) were studied at 6 weeks and 5 months of age. MiRNA and mRNA microarray experiments were performed and analyzed with bioinformatical tools, including Ingenuity Pathway Analysis (IPA). Principal component analysis showed a clear separation in both miRNA and mRNA expression levels between both ages studied, demonstrating strong age-related changes in expression. At the miRNA level, IPA identified differences between SHR and WKY related to metabolic diseases, cellular growth, and proliferation. The mRNAs differentially expressed between SHR and WKY were related to metabolism, cellular movement and proliferation. The most strongly upregulated gene (9.2-fold) was thrombospondin 4 (Thbs4), a protein involved in the endoplasmic reticulum (ER) stress response that activates transcription factor 6α (ATF6α). ATF6α downstream targets were also differentially expressed in SHR vs. WKY. Differential expression of THBS4, the cleaved form of ATF6α, and two of its targets were further confirmed at the protein level by western blot. In summary, these data revealed a number of genes (n = 202) and miRNAs (n = 3) in mesenteric arteries of SHR that had not been related to hypertension previously. The most prominent of these, Thbs4, is related to vascular ER stress that is associated with hypertension.

  6. Dietary rosemary oil alleviates heat stress-induced structural and functional damage through lipid peroxidation in the testes of growing Japanese quail.

    PubMed

    Türk, Gaffari; Çeribaşı, Ali O; Şimşek, Ülkü G; Çeribaşı, Songül; Güvenç, Mehmet; Özer Kaya, Şeyma; Çiftçi, Mehmet; Sönmez, Mustafa; Yüce, Abdurrauf; Bayrakdar, Ali; Yaman, Mine; Tonbak, Fadime

    2016-01-01

    Supplementation of natural antioxidants to diets of male poultry has been reported to be effective in reducing or completely eliminating heat stress (HS)-induced reproductive failures. In this study, the aim is to investigate whether rosemary oil (RO) has a protective effect on HS-induced damage in spermatozoa production, testicular histologic structures, apoptosis, and androgenic receptor (AR) through lipid peroxidation mechanisms in growing Japanese quail. Male chicks (n=90) at 15-days of age were assigned to two groups. The first group (n=45) was kept in a thermo-neutral (TN) room at 22°C for 24h/d. The second group (n=45) was kept in a room with a greater ambient temperature of 34°C for 8h/d (from 9:00 AM to 5:00 PM) and 22°C for 16h/d. Animals in each of these two groups were randomly assigned to three subgroups (RO groups: 0, 125, 250ppm), consisting of 15 chicks (six treatment groups in 2×3 factorial design). Each of subgroups was replicated three times with each replicate including five chicks. The HS treatment significantly reduced the testicular spermatogenic cell counts, amount of testicular Bcl-2 (anti-apoptotic marker) and amount of AR. In addition, it significantly increased testicular lipid peroxidation, Bax (apoptotic marker) immunopositive staining, and the Bax/Bcl-2 ratio in conjunction with some histopathologic damage. Dietary supplementation of RO to diets of quail where the HS treatment was imposed alleviated HS-induced almost all negative changes such as increased testicular lipid peroxidation, decreased numbers of spermatogenic cells, and decreased amounts of Bcl-2 and AR, increased ratio of Bax/Bcl-2 and some testicular histopathologic lesion. In conclusion, dietary supplementation of RO for growing male Japanese quail reared in HS environmental conditions alleviates the HS-induced structural and functional damage by providing a decrease in lipid peroxidation.

  7. Exogenous proline mediates alleviation of cadmium stress by promoting photosynthetic activity, water status and antioxidative enzymes activities of young date palm (Phoenix dactylifera L.).

    PubMed

    Zouari, M; Ben Ahmed, Ch; Zorrig, W; Elloumi, N; Rabhi, M; Delmail, D; Ben Rouina, B; Labrousse, P; Ben Abdallah, F

    2016-06-01

    The ability of exogenous compatible solutes, such as proline, to counteract cadmium (Cd) inhibitory effects in young date palm plants (Phoenix dactylifera L. cv Deglet Nour) was investigated. Two-year-old date palm plants were subjected for five months at different Cd stress levels (0, 10 and 30 mg CdCl2 kg(-1) soil) whether supplied or not with exogenous proline (20mM) added through the irrigation water. Different levels of Cd stress altered plant growth, gas exchanges and chlorophyll content as well as water status, but at different extent among them. In contrast, an increase of antioxidant enzymes activities of Cd-treated plants in association with high amounts of proline content, hydrogen peroxide (H2O2), thiobarbituric acid reactive substances (TBARS) and electrolyte leakage (EL) were observed. Interestingly, exogenous proline mitigated the adverse effects of Cd on young date palm. Indeed, it alleviated the oxidative damage induced by Cd accumulation and established better levels of plant growth, water status and photosynthetic activity. Moreover, proline-treated plants showed high antioxidant enzymes activities (superoxide dismutase, catalase and glutathione peroxydase) in roots and leaves as compared to Cd-treated plants. PMID:26901506

  8. Hydroalcoholic seed extract of Coriandrum sativum (Coriander) alleviates lead-induced oxidative stress in different regions of rat brain.

    PubMed

    Velaga, Manoj Kumar; Yallapragada, Prabhakara Rao; Williams, Dale; Rajanna, Sharada; Bettaiya, Rajanna

    2014-06-01

    Lead exposure is known to cause apoptotic neurodegeneration and neurobehavioral abnormalities in developing and adult brain by impairing cognition and memory. Coriandrum sativum is an herb belonging to Umbelliferae and is reported to have a protective effect against lead toxicity. In the present investigation, an attempt has been made to evaluate the protective activity of the hydroalcoholic extract of C. sativum seed against lead-induced oxidative stress. Male Wistar strain rats (100-120 g) were divided into four groups: control group: 1,000 mg/L of sodium acetate; exposed group: 1,000 mg/L lead acetate for 4 weeks; C. sativum treated 1 (CST1) group: 250 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure; C. sativum treated 2 (CST2) group: 500 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure. After the exposure and treatment periods, rats were sacrificed by cervical dislocation, and the whole brain was immediately isolated and separated into four regions: cerebellum, hippocampus, frontal cortex, and brain stem along with the control group. After sacrifice, blood was immediately collected into heparinized vials and stored at 4 °C. In all the tissues, reactive oxygen species (ROS), lipid peroxidation products (LPP), and total protein carbonyl content (TPCC) were estimated following standard protocols. An indicator enzyme for lead toxicity namely delta-amino levulinic acid dehydratase (δ-ALAD) activity was determined in the blood. A significant (p<0.05) increase in ROS, LPP, and TPCC levels was observed in exposed rat brain regions, while δ-ALAD showed a decrease indicating lead-induced oxidative stress. Treatment with the hydroalcoholic seed extract of C. sativum resulted in a tissue-specific amelioration of oxidative stress produced by lead.

  9. The Effect of Glucose Concentration and Sodium Phenylbutyrate Treatment on Mitochondrial Bioenergetics and ER Stress in 3T3-L1 Adipocytes

    PubMed Central

    Tanis, Ross M.; Piroli, Gerardo G.; Day, Stani D.; Frizzell, Norma

    2016-01-01

    While the 3T3-L1 adipocyte model is routinely used for the study of obesity and diabetes, the mitochondrial respiratory profile in normal versus high glucose has not been examined in detail. We matured adipocytes in normal (5 mM) or high (30 mM) glucose and insulin and examined the mitochondrial bioenergetics. We also assessed the requirement for the Unfolded Protein Response (UPR) and ER stress under these conditions. Basal respiration was ∼1.7-fold greater in adipocytes that had matured in 30 mM glucose; however, their ability to increase oxygen consumption in response to stress was impaired. Adipogenesis proceeded in both normal and high glucose with concomitant activation of the UPR, but only high glucose was associated with increased levels of ER stress and mitochondrial stress as observed by parallel increases in CHOP and protein succination. Treatment of adipocytes with sodium phenylbutyrate relieved mitochondrial stress through a reduction in mitochondrial respiration. Our data suggests that mitochondrial stress, protein succination and ER stress are uniquely linked in adipocytes matured in high glucose. PMID:25448036

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

    PubMed

    Fernandes, Hugo J R; Hartfield, Elizabeth M; Christian, Helen C; Emmanoulidou, Evangelia; Zheng, Ying; Booth, Heather; Bogetofte, Helle; Lang, Charmaine; Ryan, Brent J; Sardi, S Pablo; Badger, Jennifer; Vowles, Jane; Evetts, Samuel; Tofaris, George K; Vekrellis, Kostas; Talbot, Kevin; Hu, Michele T; James, William; Cowley, Sally A; Wade-Martins, Richard

    2016-03-01

    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. PMID:26905200

  11. [Effect of cadmium stress on physiological characteristics of garlic seedlings and the alleviation effects of exogenous calcium].

    PubMed

    Li, He; Lian, Hai-feng; Liu, Shi-qi; Yu, Xin-hui; Sun, Ya-li; Guo, Hui-ping

    2015-04-01

    In the experiment, the effects of exogenous cadmium (Cd2+) and calcium (Ca2+) in nutrient solution on growth, photosynthetic characteristics, enzymes activities, main mineral elements absorption of garlic seedlings were studied. The results showed that cadmium could obviously inhibit the growth of garlic seedlings, decrease the pigment contents and photosynthetic parameters (P(n), E, g(s)) of leaves, reduced the enzymes (SOD, POD, CAT) activities and increase the MDA content of leaves, and also could reduce the N, P, K, Ca, Mg contents and increase the Cd content of roots. The growth was promoted after adding exogenous calcium to garlic seedlings under cadmium stress, which reflected that the morphological indexes were increased at first and then decreased with the increase of exogenous calcium concentrations, and were maximized when the exogenous calcium was 2 or 3 mmol x L(-1). At the same time, the pigment contents and photosynthetic parameters (P(n), E, g(s)) of leaves showed a similar tendency with the morphological indexes, and they were the highest when the exogenous calcium was 2 or 3 mmol x L(-1). In addition, adding exogenous calcium to garlic seedlings under cadmium stress enhanced the enzymes (SOD, POD, CAT) activities and decreased the MDA content of leaves, also added the N, P, K, Ca, Mg contents and reduced the Cd content of roots, and the effect was best when the exogenous calcium concentration was 2 or 3 mmol x L(-1).

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

    SciTech Connect

    Kito, Hiroaki; Yamazaki, Daiju; Ohya, Susumu; Yamamura, Hisao; Asai, Kiyofumi; Imaizumi, Yuji

    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.

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

    SciTech Connect

    Li, Ying; Li, Jia; Li, Shanshan; Li, Yi; Wang, Xiangxiang; Liu, Baolin; Fu, Qiang; Ma, Shiping

    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.

  14. Melatonin alleviates hyperthyroidism induced oxidative stress and neuronal cell death in hippocampus of aged female golden hamster, Mesocricetus auratus.

    PubMed

    Rao, Geeta; Verma, Rakesh; Mukherjee, Arun; Haldar, Chandana; Agrawal, Neeraj Kumar

    2016-09-01

    Oxidative stress is a well known phenomenon under hyperthyroid condition that induces various physiological and neural problems with a higher prevalence in females. We, therefore investigated the antioxidant potential of melatonin (Mel) on hyperthyroidism-induced oxidative stress and neuronal cell death in the hippocampus region of brain (cognition and memory centre) of aged female golden hamster, Mesocricetus auratus. Aged female hamsters were randomly divided into four experimental groups (n=7); group-I: control, group-II: Melatonin (5mgkg(-1)day(-1), i.p., for one week), group-III: Hyperthyroid (100μg kg(-1)day(-1), i.p., for two weeks) and group-IV- Hyper+Mel. Hormonal profiles (thyroid and melatonin), activity of antioxidant enzymes (SOD, CAT and GPX), lipid peroxidation level (TBARS) and the specific apoptotic markers (Bax/Bcl-2 ratio and Caspase-3) expression were evaluated. A significant increase in the profile of total thyroid hormone (tT3 and tT4) in hyperthyroidic group as compared to control while tT3 significantly decreased in melatonin treated hyperthyroidic group. However, Mel level significantly decreased in hyperthyroidic group but increased in melatonin treated hyperthyroidic group. Further, the number of immune-positive cells for thyroid hormone receptor-alpha (TR-α) decreased in the hippocampus of hyperthyroidic group and increased in melatonin treated hyperthyroidic group. Profiles of antioxidant enzymes showed a significant decrease in hyperthyroidic group with a simultaneous increase in lipid peroxidation (TBARS). Melatonin treatment to hyperthyroidic group lead to decreased TBARS level with a concomitant increase in antioxidant enzyme activity. Moreover, increased expression of Bax/Bcl-2 ratio and Caspase-3, in hyperthyroidic group had elevated neuronal cell death in hippocampal area and melatonin treatment reduced its expression in hyperthyroidic group. Our findings thus indicate that melatonin reduced the hyperthyroidism

  15. Cross-talk between endoplasmic reticulum (ER) stress and the MEK/ERK pathway potentiates apoptosis in human triple negative breast carcinoma cells: role of a dihydropyrimidone, nifetepimine.

    PubMed

    Ghosh, Swatilekha; Adhikary, Arghya; Chakraborty, Supriya; Bhattacharjee, Pushpak; Mazumder, Minakshi; Putatunda, Salil; Gorain, Mahadeo; Chakraborty, Arijit; Kundu, Gopal C; Das, Tanya; Sen, Parimal C

    2015-02-13

    Triple negative breast cancers (TNBC) are among the most aggressive and therapy-resistant breast tumors and currently possess almost no molecular targets for therapeutic options in this horizon. In the present study we discerned the molecular mechanisms of potential interaction between the endoplasmic reticulum (ER) stress response and the MEK/ERK pathway in inducing apoptosis in TNBC cells. Here we observed that induction of ER stress alone was not sufficient to trigger significant apoptosis but simultaneous inhibition of the MEK/ERK pathway enhanced ER stress-induced apoptosis via a caspase-dependent mechanism. Our study also demonstrated nifetepimine, a dihydropyrimidone derivative as a potent anti-cancer agent in TNBC cells. Nifetepimine down-regulated the MEK/ERK pathway in MDAMB-231 and MDAMB-468 cells and resulted in blockage of ER stress-mediated GRP78 up-regulation. Detailed mechanistic studies also revealed that nifetepimine by down-regulating pERK expression also declined the promoter binding activity of TFII-I to the GRP78 promoter and in turn regulated GRP78 transcription. Studies further extended to in vivo Swiss albino and SCID mice models also revalidated the anti-carcinogenic property of nifetepimine. Thus our findings cumulatively suggest that nifetepimine couples two distinct signaling pathways to induce the apoptotic death cascade in TNBC cells and raises the possibility for the use of nifetepimine as a potent anti-cancer agent with strong immune-restoring properties for therapeutic intervention for this group of cancer bearers.

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

    PubMed Central

    Chen, Yingqing; Pandiri, Indira; Joe, Yeonsoo; Kim, Hyo Jeong; Kim, Seul-Ki; Park, Jeongmin; Ryu, Jinhyun; Cho, Gyeong Jae; Park, Jeong Woo; Ryter, Stefan W.; Chung, Hun Taeg

    2016-01-01

    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. PMID:27057275

  17. Effect of BSA-induced ER stress on SGLT protein expression levels and alpha-MG uptake in renal proximal tubule cells.

    PubMed

    Lee, Yu Jin; Suh, Han Na; Han, Ho Jae

    2009-06-01

    Recent studies demonstrated that endoplasmic reticulum (ER) stress regulates glucose homeostasis and that ER stress preconditioning which induces an adaptive, protective unfolded protein response (UPR) offers cytoprotection against nephrotoxins. Thus the aim of the present study was to use renal proximal tubule cells (PTCs) to further elucidate the link between the BSA-induced ER stress and alpha-methyl-d-glucopyranoside (alpha-MG) uptake and to identify related signaling pathways. Among ER stress inducers such as high glucose, BSA, H2O2, or tumicamycin, BSA pretreatment ameliorated the reduction of Na(+)-glucose cotransporter (SGLT) expression and alpha-MG uptake by gentamicin or cyclosporine A. Immunofluorescence studies revealed that BSA (10 mg/ml) stimulated the expression of glucose-regulated protein 78 (GRP78), an ER stress biomarker. In addition, BSA increased levels of GRP78 protein expression and eukaryotic initiation factor 2alpha (eIF2alpha) phosphorylation in a time-dependent manner. Furthermore, transfection with a GRP78-specific small interfering RNA (siRNA) inhibited BSA-stimulated SGLT expression and alpha-MG uptake. In experiments designed to unravel the mechanisms underlying BSA-induced ER stress, BSA stimulated the production of cellular reactive oxygen species (ROS), and antioxidants such as ascorbic acid or N-acetylcysteine (NAC) blocked BSA-induced increases in GRP78 activation, eIF2alpha phosphorylation, SGLT expression, and alpha-MG uptake. Moreover, the cells upregulated peroxisome proliferator-activated receptor-gamma (PPARgamma) mRNA levels in response to BSA or troglitazone (a PPARgamma agonist), but BSA was ineffective in the presence of GW9662 (a PPARgamma antagonist). In addition, both BSA and troglitazone stimulated GRP78 and eIF2alpha activation, SGLT expression, and alpha-MG uptake, whereas GW9662 inhibited the effects of BSA. BSA also stimulated phosphorylation of JNK and NF-kappaB, and GW9662 or GRP78 siRNA attenuated this

  18. Oral treatment with the herbal formula B307 alleviates cardiac toxicity in doxorubicin-treated mice via suppressing oxidative stress, inflammation, and apoptosis

    PubMed Central

    Lien, Chia-Ying; Chuang, Tai-Yuan; Hsu, Chih-Hsiang; Lin, Ching-Lung; Wang, Sheue-Er; Sheu, Shuenn-Jyi; Chien, Chiang-Ting; Wu, Chung-Hsin

    2015-01-01

    Objective This study aimed to investigate whether the herbal formula B307 could alleviate doxorubicin (DOX)-induced acute cardiotoxicity. If so, we further unraveled possible molecular mechanisms of cardiac protection under treatment with the herbal formula B307. Methods Before the animal experiment, we examined relative viabilities of Huh7 cancer cells under treatment with the herbal formula B307. To test whether oral treatment with the herbal formula B307 could alleviate cardiotoxicity, equal volumes of B307 (50 mg/kg) or saline (sham treatment) were administered to 20-week-old male mice once daily for 14 consecutive days. Then, DOX (10 mg/kg; ip) was administered to male mice under B307 and sham treatments at 22–23 weeks of age. Cardiac functions in these mice were assessed via echocardiography at 23–24 weeks of age. Then, expressions of oxidative stress, inflammation, and apoptosis-related proteins were examined in the heart tissue by immunohistochemistry and Western blotting at 24–25 weeks of age. Apart from this, mortality rate and body weight were measured during the experiment. Results In vitro, the relative viabilities of Huh7 cancer cells under treatment with the herbal formula B307 had shown no obvious change at doses of 10–160 ng/mL. Furthermore, the relative viabilities of Huh7 cancer cells were significantly reduced under DOX treatment but showed no significant change under DOX only and DOX plus B307 treatment. In vivo, the mortality rate, body weight, and cardiac function of DOX-treated mice were obviously improved under oral treatment with the herbal formula B307. Furthermore, cardiac expressions of endothelial nitric oxide synthase, superoxide dismutase 2, and B-cell lymphoma 2 were significantly enhanced, but tumor necrosis factor alpha, NFKB1 (p50 and its precursor, p105), neurotrophin-3, Bcl-2-associated X protein, calpain, caspase 12, caspase 9, and caspase 3 were significantly suppressed in DOX-treated mice under oral treatment with

  19. The PERK-eIF2α signaling pathway is involved in TCDD-induced ER stress in PC12 cells.

    PubMed

    Duan, Zhiqing; Zhao, Jianya; Fan, Xikang; Tang, Cuiying; Liang, Lingwei; Nie, Xiaoke; Liu, Jiao; Wu, Qiyun; Xu, Guangfei

    2014-09-01

    Studies have shown that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces apoptotic cell death in neuronal cells. However, whether this is the result of endoplasmic reticulum (ER) stress-mediated apoptosis remains unknown. In this study, we determined whether ER stress plays a role in the TCDD-induced apoptosis of pheochromocytoma (PC12) cells and primary neurons. PC12 cells were exposed to different TCDD concentrations (1, 10, 100, 200, or 500nM) for varying lengths of time (1, 3, 6, 12, or 24h). TCDD concentrations much higher than 10nM (100, 200, or 500nM) markedly increased glucose-regulated protein (GRP78) and C/EBP homologous protein (CHOP) levels, which are hallmarks of ER stress. We also evaluated the effects of TCDD on ER morphology in PC12 cells and primary neurons that were treated with different TCDD concentrations (1, 10, 50, or 200nM) for 24h. Ultrastructural ER alterations were observed with transmission electron microscopy in PC12 cells and primary neurons treated with high concentrations of TCDD. Furthermore, TCDD-induced ER stress significantly promoted the activation of the PKR-like ER kinase (PERK), a sensor for the unfolded protein response (UPR), and its downstream target eukaryotic translation initiation factor 2 α (eIF2α); in contrast, TCDD did not appear to affect inositol-requiring enzyme 1 (IRE1) and activating transcription factor 6 (ATF6), two other UPR sensors. Importantly, TCDD significantly inhibited eIF2α phosphorylation and triggered apoptosis in PC12 cells after 6-24h of treatment. Salubrinal, which activates the PERK-eIF2α pathway, significantly enhanced eIF2α phosphorylation in PC12 cells and attenuated the TCDD-induced cell death. In contrast, knocking down eIF2α using small interfering RNA markedly enhanced TCDD-induced cell death. Together, these results indicate that the PERK-eIF2α pathway plays an important role in TCDD-induced ER stress and apoptosis in PC12 cells. PMID:24932542

  20. Inhibition of autophagy enhances heat-induced apoptosis in human non-small cell lung cancer cells through ER stress pathways.

    PubMed

    Xie, Wen-Yue; Zhou, Xiang-Dong; Yang, Juan; Chen, Ling-Xiu; Ran, Dan-Hua

    2016-10-01

    The occurrence and mechanisms of autophagy induced by heat stress are not well known in lung cancer cells. Here, we have demonstrated that heat stress induces autophagy in A549 and NCI-H460 cells through morphological and biochemical analyses. The inhibition of autophagy by chloroquine, 3-methyladenine and Beclin 1 siRNA enhanced heat-induced apoptosis. Moreover, the combination of chloroquine and heat stress inhibited tumor growth and enhanced apoptosis in vivo experiments. In addition, heat-induced autophagy involved the ER stress pathway (PERK- or IRE1-dependent). Further, heat treatment led to the increased phosphorylation of AMPK and the decreased phosphorylation of mTOR in vitro and in vivo. Knockdown of GRP78 inhibited the AMPK-mTOR pathway, and the AMPK inhibitor compound C decreased heat-induced autophagy, suggesting that activation of ER stress was involved in autophagy induction and promotion of the AMPK-mTOR pathway. In conclusion, our data suggested that the heat treatment of lung cancer cells triggered protective autophagy, as mediated by ER stress. Thus, inhibition of autophagy can be a promising strategy to enhance hyperthermia in the treatment of lung cancer patients.

  1. Bilberries potentially alleviate stress-related retinal gene expression induced by a high-fat diet in mice

    PubMed Central

    Kalesnykas, Giedrius; Adriaens, Michiel; Evelo, Chris T.; Törrönen, Riitta; Kaarniranta, Kai

    2012-01-01

    displayed differential regulation of genes in ontology groups, mainly pathways for apoptosis, inflammation, and oxidative stress, especially systemic lupus erythematosus, mitogen-activated protein kinase, and glutathione metabolism. Mice fed a HFD had increased retinal gene expression of several crystallins, while the HFD+BB mice showed potential downregulation of these crystallins when compared to the HFD mice. Bilberries also reduced the expression of genes in the mitogen-activated protein kinase (MAPK) pathway and increased those in the glutathione metabolism pathway. Conclusions HFD feeding induces differential expression of several stress-related genes in the mouse retina. Despite minor effects in the phenotype, a diet rich in bilberries mitigates the upregulation of crystallins otherwise induced by HFD. Thus, the early stages of obesity-associated and stress-related gene expression changes in the retina may be prevented with bilberries in the diet. PMID:22993483

  2. DOT1L Activity Promotes Proliferation and Protects Cortical Neural Stem Cells from Activation of ATF4-DDIT3-Mediated ER Stress In Vitro.

    PubMed

    Roidl, Deborah; Hellbach, Nicole; Bovio, Patrick P; Villarreal, Alejandro; Heidrich, Stefanie; Nestel, Sigrun; Grüning, Björn A; Boenisch, Ulrike; Vogel, Tanja

    2016-01-01

    Growing evidence suggests that the lysine methyltransferase DOT1L/KMT4 has important roles in proliferation, survival, and differentiation of stem cells in development and in disease. We investigated the function of DOT1L in neural stem cells (NSCs) of the cerebral cortex. The pharmacological inhibition and shRNA-mediated knockdown of DOT1L impaired proliferation and survival of NSCs. DOT1L inhibition specifically induced genes that are activated during the unfolded protein response (UPR) in the endoplasmic reticulum (ER). Chromatin-immunoprecipitation analyses revealed that two genes encoding for central molecules involved in the ER stress response, Atf4 and Ddit3 (Chop), are marked with H3K79 methylation. Interference with DOT1L activity resulted in transcriptional activation of both genes accompanied by decreased levels of H3K79 dimethylation. Although downstream effectors of the UPR, such as Ppp1r15a/Gadd34, Atf3, and Tnfrsf10b/Dr5 were also transcriptionally activated, this most likely occurred in response to increased ATF4 expression rather than as a direct consequence of altered H3K79 methylation. While stem cells are particularly vulnerable to stress, the UPR and ER stress have not been extensively studied in these cells yet. Since activation of the ER stress program is also implicated in directing stem cells into differentiation or to maintain a proliferative status, the UPR must be tightly regulated. Our and published data suggest that histone modifications, including H3K4me3, H3K14ac, and H3K79me2, are implicated in the control of transcriptional activation of ER stress genes. In this context, the loss of H3K79me2 at the Atf4- and Ddit3-promoters appears to mark a point-of-no-return that activates the death program in NSCs.

  3. Alleviation of salt stress by halotolerant and halophilic plant growth-promoting bacteria in wheat (Triticum aestivum).

    PubMed

    Orhan, Furkan

    2016-01-01

    In the current study, 18 halotolerant and halophilic bacteria have been investigated for their plant growth promoting abilities in vitro and in a hydroponic culture. The bacterial strains have been investigated for ammonia, indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate-deaminase production, phosphate solubilisation and nitrogen fixation activities. Of the tested bacteria, eight were inoculated with Triticum aestivum in a hydroponic culture. The investigated bacterial strains were found to have different plant-growth promoting activities in vitro. Under salt stress (200mM NaCl), the investigated bacterial strains significantly increased the root and shoot length and total fresh weight of the plants. The growth rates of the plants inoculated with bacterial strains ranged from 62.2% to 78.1%. Identifying of novel halophilic and halotolerant bacteria that promote plant growth can be used as alternatives for salt sensitive plants. Extensive research has been conducted on several halophilic and halotolerant bacterial strains to investigate their plant growth promoting activities. However, to the best of my knowledge, this is the first study to inoculate these bacterial strains with wheat. PMID:27133557

  4. Globular adiponectin reduces vascular calcification via inhibition of ER-stress-mediated smooth muscle cell apoptosis

    PubMed Central

    Lu, Yan; Bian, Yunfei; Wang, Yueru; Bai, Rui; Wang, Jiapu; Xiao, Chuanshi

    2015-01-01

    Objective: This study aims to explore the mechanism of globular adiponectin inhibiting vascular calcification. Methods: We established drug-induced rat vascular calcification model, globular adiponectin was given to observe the effect of globular Adiponectin on the degree of calcification. The markers of vascular calcification and apoptosis were also investigated. Meanwhile, the in vitro effect of globular Adiponectin on vascular calcification was also evaluated using primary cultured rat vascular smooth muscle cells. Results: We found that globular adiponectin could inhibit drug-induced rat vascular calcification significantly in vivo. The apoptosis of vascular smooth muscle cells was also reduced. The possible mechanism could be the down-regulation of endoplasmic reticulum stress by globular adiponectin. Experiments in primary cultured vascular smooth muscle cells also confirmed that globular adiponectin could reduce cell apoptosis to suppress vascular calcification via inhibition of endoplasmic reticulum stress. Conclusions: This study confirmed that globular adiponectin could suppress vascular calcification; one of the mechanisms could be inhibition of endoplasmic reticulum stress to reduce cell apoptosis. It could provide an effective method in the therapy of vascular calcification-associated diseases. PMID:26045760

  5. Leukotriene D4 receptor antagonist montelukast alleviates water avoidance stress-induced degeneration of the gastrointestinal mucosa.

    PubMed

    Ersoy, Yasemin; Cikler, Esra; Cetinel, Sule; Sener, Göksel; Ercan, Feriha

    2008-03-01

    We investigated the role of montelukast (ML), a cysteinyl leukotriene-1 receptor antagonist, on the water avoidance stress (WAS)-induced degeneration of the rat gastric, ileal and colonic mucosa. One group of Wistar albino rats were exposed to chronic WAS (WAS group) 2h daily for 5 days. Another group was administered ML (10mg/kg; i.p.; WAS+ML group) following every WAS exposure for 5 days. Control rats were injected with the vehicle solution only. The stomach, ileum and colon were dissected and investigated for histopathological changes with a light microscope as well as for topographical changes with a scanning electron microscope. The levels of malondialdehyde (MDA, a biomarker of oxidative damage) and glutathione (GSH, a biomarker of protective oxidative injury) were also determined in all dissected tissues. In the WAS group, the stomach epithelium showed ulceration in some areas, dilatations of the gastric glands, degeneration of gastric glandular cells, and prominent congestion of the capillaries. In a similar fashion, degenerated epithelium and severe vascular congestions were observed in the ileum and colon. In all the tissues dense inflammatory cell infiltration and mast cell degranulation in mucosa were observed. The levels of MDA were significantly increased whereas those of GSH were significantly decreased in all test tissues in the WAS group compared to the control group. The morphology of gastric, ileal and colonic mucosa in WAS+ML group showed a significant amelioration showing a reduction in inflammatory cell infiltration and mast cell degranulation. Increased MDA and decreased GSH levels in the WAS group were also ameliorated with ML treatment. Based on the results, ML supplement seems attenuated inflammatory effects of WAS induction in gastrointestinal mucosa.

  6. Effect of treatment of cow's urine "Gomutra" and antioxidants in alleviating the lindane-induced oxidative stress in kidney of Swiss mice (Mus musculus).

    PubMed

    Nagda, Girima; Bhatt, Devendra Kumar

    2014-01-01

    The study aimed to evaluate the effect of cow urine and combination of antioxidants against lindane induced oxidative stress in Swiss mice. Male healthy mice, 8-10 weeks old, weighing 30 ± 5 g were randomly selected and divided into eight groups, namely, control (C); lindane (L); antioxidant (A), antioxidant+lindane (A+L), cow urine (U), cow urine+lindane (U+L), cow urine+antioxidants (U+A) and cow urine+antioxidants+lindane (U+A+L). Group C animals were administered only the vehicle (olive oil); doses selected for other treatments were: lindane: 40 mg/kg b.w.; antioxidants: 125 mg/kg b.w. (vitamin C: 50 mg/kg b.w., vitamin E: 50 mg/kg b.w., α-lipoic acid: 25 mg/kg b.w.) and cow urine: 0.25 ml/kg b.w. In group A+L and U+L antioxidants and cow urine were administered 1 h prior to lindane administration and in group U+A and U+A+L cow urine was administered 10 min before antioxidants. All treatments were administered orally continuously for 60 days. Lindane treated group showed increased lipid peroxidation, whereas glutathione, glutathione peroxidase, superoxide dismutase, catalase, protein and endogenous levels of vitamin C and E were significantly decreased compared to control. Administration of cow urine and antioxidants alleviated the levels of these biochemical parameters.

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

    PubMed Central

    Pereira, Heloisa Aparecida Barbosa Silva; Dionizio, Aline Salgado; Fernandes, Mileni Silva; Araujo, Tamara Teodoro; Cestari, Tânia Mary; Buzalaf, Camila Peres; Iano, Flávia Godoy; Buzalaf, Marília Afonso Rabelo

    2016-01-01

    The role of fluoride (F) in oxidative stress is well reported, but its effects on the lipid metabolism has not been completely explored Background 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). Methods 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. Results 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. Conclusions 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. PMID:27336443

  8. Endoplasmic reticulum (ER) stress-suppressive compounds from scrap cultivation beds of the mushroom Hericium erinaceum.

    PubMed

    Ueda, Keiko; Kodani, Shinya; Kubo, Masakazu; Masuno, Kazuhiko; Sekiya, Atsushi; Nagai, Kaoru; Kawagishi, Hirokazu

    2009-08-01

    Four compounds were isolated from scrap cultivation beds of the mushroom, Hericium erinaceum. Compounds 1-4 were identified as methyl 4-hydroxy-3-(3-methylbutanoyl) benzoate, 2-chloro-1,3-dimethoxy-5-methylbenzene, methyl 4-chloro-3,5-dimethoxybenzoate, and 4-chloro-3,5-dimethoxybenzaldehyde by an interpretation of the NMR and MS data, respectively. This is the first reported isolation of 1 from a natural source. All the compounds showed protective activity against endoplasmic reticulum stress-dependent cell death.

  9. Resveratrol alleviates diabetes-induced testicular dysfunction by inhibiting oxidative stress and c-Jun N-terminal kinase signaling in rats.

    PubMed

    Faid, Iman; Al-Hussaini, Heba; Kilarkaje, Narayana

    2015-12-15

    Diabetes adversely affects reproductive functions in humans and animals. The present study investigated the effects of Resveratrol on diabetes-induced alterations in oxidative stress, c-Jun N-terminal kinase (JNK) signaling and apoptosis in the testis. Adult male Wistar rats (13-15 weeks; n=6/group) were segregated into 1) normal control, 2) Resveratrol-treated (5mg/kg; ip; given during last 3 weeks), 3) Streptozotocin-induced diabetic and, 4) Resveratrol-treated diabetic groups, and euthanized on day 42 after the confirmation of diabetes. Resveratrol did not normalize blood glucose levels in diabetic rats. Resveratrol supplementation recovered diabetes-induced decreases in reproductive organ weights, sperm count and motility, intra-testicular levels of superoxide dismutase, catalase, and glutathione peroxidase and an increase in 4-hydroxynonenal activities (P<0.05). Resveratrol also recovered diabetes-induced increases in JNK signaling pathway proteins, namely, ASK1 (apoptosis signal-regulating kinase 1), JNKs (46 and 54 kDa isoforms) and p-JNK to normal control levels (P<0.05). Interestingly, the expression of a down-stream target of ASK1, MKK4 (mitogen-activated protein kinase kinase 4) and its phosphorylated form (p-MKK4) did not change in experimental groups. Resveratrol inhibited diabetes-induced increases in AP-1 (activator protein-1) components, c-Jun and ATF2 (activating transcription factor 2), but not their phosphorylated forms, to normal control levels (P<0.05). Further, Resveratrol inhibited diabetes-induced increase in cleaved-caspase-3 to normal control levels. In conclusion, Resveratrol alleviates diabetes-induced apoptosis in testis by modulating oxidative stress, JNK signaling pathway and caspase-3 activities, but not by inhibiting hyperglycemia, in rats. These results suggest that Resveratrol supplementation may be a useful strategy to treat diabetes-induced testicular dysfunction.

  10. Undernourishment in utero Primes Hepatic Steatosis in Adult Mice Offspring on an Obesogenic Diet; Involvement of Endoplasmic Reticulum Stress

    PubMed Central

    Muramatsu-Kato, Keiko; Itoh, Hiroaki; Kohmura-Kobayashi, Yukiko; Ferdous, Urmi J.; Tamura, Naoaki; Yaguchi, Chizuko; Uchida, Toshiyuki; Suzuki, Kazunao; Hashimoto, Koshi; Suganami, Takayoshi; Ogawa, Yoshihiro; Kanayama, Naohiro

    2015-01-01

    In order to investigate the possible involvement of endoplasmic reticulum (ER) stress in the developmental origins of hepatic steatosis associated with undernourishment in utero, we herein employed a fetal undernourishment mouse model by maternal caloric restriction in three cohorts; cohort 1) assessment of hepatic steatosis and the ER stress response at 9 weeks of age (wks) before a high fat diet (HFD), cohort 2) assessment of hepatic steatosis and the ER stress response on a HFD at 17 wks, cohort 3) assessment of hepatic steatosis and the ER stress response at 22 wks on a HFD after the alleviation of ER stress with a chemical chaperone, tauroursodeoxycholic acid (TUDCA), from 17 wks to 22 wks. Undernourishment in utero significantly deteriorated hepatic steatosis and led to the significant integration of the ER stress response on a HFD at 17 wks. The alleviation of ER stress by the TUDCA treatment significantly improved the parameters of hepatic steatosis in pups with undernourishment in utero, but not in those with normal nourishment in utero at 22 wks. These results suggest the pivotal involvement of the integration of ER stress in the developmental origins of hepatic steatosis in association with undernourishment in utero. PMID:26581663

  11. Alleviation of Photoinhibition by Co-ordination of Chlororespiration and Cyclic Electron Flow Mediated by NDH under Heat Stressed Condition in Tobacco

    PubMed Central

    Li, Qinghua; Yao, Zheng-Ju; Mi, Hualing

    2016-01-01

    much more in the mutant. The results suggest that chlororespiration and cyclic electron flow mediated by NDH may coordinate to alleviate the over-reduction of stroma, thus to keep operation of CO2 assimilation at certain extent under heat stress condition. PMID:27066014

  12. Impairment of Visual Function and Retinal ER Stress Activation in Wfs1-Deficient Mice

    PubMed Central

    Bonnet Wersinger, Delphine; Benkafadar, Nesrine; Jagodzinska, Jolanta; Hamel, Christian; Tanizawa, Yukio; Lenaers, Guy; Delettre, Cécile

    2014-01-01

    Wolfram syndrome is an early onset genetic disease (1/180,000) featuring diabetes mellitus and optic neuropathy, associated to mutations in the WFS1 gene. Wfs1−/− mouse model shows pancreatic beta cell atrophy, but its visual performance has not been investigated, prompting us to study its visual function and histopathology of the retina and optic nerve. Electroretinogram and visual evoked potentials (VEPs) were performed in Wfs1−/− and Wfs1+/+ mice at 3, 6, 9 and 12 months of age. Fundi were pictured with Micron III apparatus. Retinal ganglion cell (RGC) abundance was determined from Brn3a immunolabeling of retinal sections. RGC axonal loss was quantified by electron microscopy in transversal optic nerve sections. Endoplasmic reticulum stress was assessed using immunoglobulin binding protein (BiP), protein disulfide isomerase (PDI) and inositol-requiring enzyme 1 alpha (Ire1α) markers. Electroretinograms amplitudes were slightly reduced and latencies increased with time in Wfs1−/− mice. Similarly, VEPs showed decreased N+P amplitudes and increased N-wave latency. Analysis of unfolded protein response signaling revealed an activation of endoplasmic reticulum stress in Wfs1−/− mutant mouse retinas. Altogether, progressive VEPs alterations with minimal neuronal cell loss suggest functional alteration of the action potential in the Wfs1−/− optic pathways. PMID:24823368

  13. Oral treatment with herbal formula B307 alleviates cardiac failure in aging R6/2 mice with Huntington's disease via suppressing oxidative stress, inflammation, and apoptosis.

    PubMed

    Lin, Ching-Lung; Wang, Sheue-Er; Hsu, Chih-Hsiang; Sheu, Shuenn-Jyi; Wu, Chung-Hsin

    2015-01-01

    Cardiac failure is often observed in aging patients with Huntington's disease (HD). However, conventional pharmacological treatments for cardiac failure in HD patients have rarely been studied. Chinese herbal medicines, especially combined herbal formulas, have been widely used to treat cardiac dysfunctions over the centuries. Thus, we assess whether oral treatment with herbal formula B307 can alleviate cardiac failure in transgenic mice with HD. After oral B307 or vehicle treatment for 2 weeks, cardiac function and cardiomyocytes in 12-week-old male R6/2 HD mice and their wild-type littermate controls (WT) were examined and then compared via echocardiography, immunohistochemistry, and Western blotting. We found that cardiac performance in aging R6/2 HD mice had significantly deteriorated in comparison with their WT (P<0.01). Cardiac expressions of superoxide dismutase 2 (SOD2) and B-cell lymphoma 2 (Bcl-2) in aging R6/2 HD mice were significantly lower than their WT (P<0.01), but cardiac expressions of tumor necrosis factor alpha (TNF-α), neurotrophin-3 (3-NT), 4-hydroxynonenal (4-HNE), Bcl-2-associated X protein (Bax), calpain, caspase 12, caspase 9, and caspase 3 of aging R6/2 HD mice were significantly higher than their WT (P<0.05). Furthermore, we found that cardiac performance in aging R6/2 HD mice had significantly improved under oral B307 treatment (P<0.05). Cardiac expressions of SOD2 and Bcl-2 of aging R6/2 HD mice were significantly higher under oral B307 treatment (P<0.01), but cardiac expressions of TNF-α, 3-NT, 4-HNE, Bax, calpain, caspase 12, caspase 9, and caspase 3 of aging R6/2 HD mice were significantly reduced under oral B307 treatment (P<0.05). Oral B307 treatment may briefly alleviate cardiac failure in aging HD R6/2 mice via suppressing cardiac oxidative stress, inflammation, and apoptosis. We suggested that the herbal formula B307 may be further developed as a potential health supplement for ameliorating cardiac failure associated with

  14. A highly charged region in the middle domain of plant endoplasmic reticulum (ER)-localized heat-shock protein 90 is required for resistance to tunicamycin or high calcium-induced ER stresses

    PubMed Central

    Chong, Lisa P.; Wang, Yao; Gad, Nanette; Anderson, Nathaniel; Shah, Bhavank; Zhao, Rongmin

    2015-01-01

    Heat-shock protein 90 (HSP90) is a highly conserved molecular chaperone that is involved in modulating a multitude of cellular processes under both physiological and stress conditions. In Arabidopsis, there are seven HSP90 isoforms (HSP90.1–HSP90.7) that are localized in the cytoplasm/nucleus, mitochondrion, chloroplast, and endoplasmic reticulum (ER) where protein folding actively takes place. In this study, we analysed the sequence of ER-localized Arabidopsis HSP90.7 and the other ER GRP94 proteins from plants and animals, and identified a short, charged region that is specifically present in the middle domain of plant-derived GRP94 proteins. To understand the role of this charged region, we analysed transgenic plants that expressed a mutant protein, HSP90.7Δ22, which had this charged region deleted. We showed that seedlings expressing HSP90.7Δ22 had significantly enhanced sensitivity to ER stress induced by tunicamycin or a high concentration of calcium, although its general chaperone activity in preventing the model protein from heat-induced aggregation was not significantly affected. We also analysed the ATP-binding and hydrolysis activity of both wild-type and mutant HSP90.7 proteins, and found that they had slightly different ATP-binding affinities. Finally, using a yeast two-hybrid screen, we identified a small set of HSP90.7 interactors and showed that the charged region is not required for the candidate client interaction, although it may affect their binding affinity, thus providing potential targets for further investigation of HSP90.7 functions. PMID:25297550

  15. Basal plane magnetoelastic stress in magnetic Dy/Y and Er/Lu superlattices

    NASA Astrophysics Data System (ADS)

    del Moral, A.; Ciria, M.; Arnaudas, J. I.; Ward, R. C. C.; Wells, M. R.

    1997-04-01

    The basal plane (bp) cylindrical symmetry breaking magnetoelastic stress (MS), Mγ, has been measured for the series of superlattices (SL) (Dyn/Y15) and (Erm/Lu10), with n=5, 15, 25, and m=10, 20, 30 atomic bp, from 10 K and in applied magnetic fields up to B=12 T, using a capacitive cantilever technique. Field induced transitions are observed. For both series of SLs an effective strong interfacial MS is determined at 10 K and 12 T, up to about one order of magnitude larger and of the opposite sign than the bulk MS. Mγ (12 T) scales with the power m3 of the reduced magnetization m confirming its crystal electric field origin.

  16. Regulation of glutamine carrier proteins by RNF5 determines breast cancer response to ER stress-inducing chemotherapies.

    PubMed

    Jeon, Young Joo; Khelifa, Sihem; Ratnikov, Boris; Scott, David A; Feng, Yongmei; Parisi, Fabio; Ruller, Chelsea; Lau, Eric; Kim, Hyungsoo; Brill, Laurence M; Jiang, Tingting; Rimm, David L; Cardiff, Robert D; Mills, Gordon B; Smith, Jeffrey W; Osterman, Andrei L; Kluger, Yuval; Ronai, Ze'ev A

    2015-03-01

    Many tumor cells are fueled by altered metabolism and increased glutamine (Gln) dependence. We identify regulation of the L-glutamine carrier proteins SLC1A5 and SLC38A2 (SLC1A5/38A2) by the ubiquitin ligase RNF5. Paclitaxel-induced ER stress to breast cancer (BCa) cells promotes RNF5 association, ubiquitination, and degradation of SLC1A5/38A2. This decreases Gln uptake, levels of TCA cycle components, mTOR signaling, and proliferation while increasing autophagy and cell death. Rnf5-deficient MMTV-PyMT mammary tumors were less differentiated and showed elevated SLC1A5 expression. Whereas RNF5 depletion in MDA-MB-231 cells promoted tumorigenesis and abolished paclitaxel responsiveness, SLC1A5/38A2 knockdown elicited opposing effects. Inverse RNF5(hi)/SLC1A5/38A2(lo) expression was associated with positive prognosis in BCa. Thus, RNF5 control of Gln uptake underlies BCa response to chemotherapies. PMID:25759021

  17. Regulation of Glutamine Carrier Proteins by RNF5 Determines Breast Cancer Response to ER Stress-inducing Chemotherapies

    PubMed Central

    Jeon, Young Joo; Khelifa, Sihem; Ratnikov, Boris; Scott, David A.; Feng, Yongmei; Parisi, Fabio; Ruller, Chelsea; Lau, Eric; Kim, Hyungsoo; Brill, Laurence M.; Jiang, Tingting; Rimm, David; Cardiff, Robert D.; Mills, Gordon B.; Smith, Jeffrey W.; Osterman, Andrei L.; Kluger, Yuval; Ronai, Ze'ev A.

    2015-01-01

    Summary Many tumor cells are fueled by altered metabolism and increased glutamine (Gln) dependence. We identify regulation of the L-glutamine carrier proteins SLC1A5 and SLC38A2 (SLC1A5/38A2) by the ubiquitin ligase RNF5. Paclitaxel-induced ER stress to breast cancer (BCa) cells promotes RNF5 association, ubiquitination and degradation of SLC1A5/38A2. This decreases Gln uptake, levels of TCA cycle components, mTOR signaling and proliferation while increasing autophagy and cell death. Rnf5-deficient MMTV-PyMT mammary tumors were less differentiated and showed elevated SLC1A5 expression. Whereas RNF5 depletion in MDA-MB-231 cells promoted tumorigenesis and abolished paclitaxel responsiveness, SLC1A5/38A2 knockdown elicited opposing effects. Inverse RNF5HI/SLC1A5/38A2LO expression was associated with positive prognosis in BCa. Thus, RNF5 control of Gln uptake underlies BCa response to chemotherapies. PMID:25759021

  18. Corticospinal Motor Neurons Are Susceptible to Increased ER Stress and Display Profound Degeneration in the Absence of UCHL1 Function

    PubMed Central

    Jara, Javier H.; Genç, Barış; Cox, Gregory A.; Bohn, Martha C.; Roos, Raymond P.; Macklis, Jeffrey D.; Ulupınar, Emel; Özdinler, P. Hande

    2015-01-01

    Corticospinal motor neurons (CSMN) receive, integrate, and relay cerebral cortex's input toward spinal targets to initiate and modulate voluntary movement. CSMN degeneration is central for numerous motor neuron disorders and neurodegenerative diseases. Previously, 5 patients with mutations in the ubiquitin carboxy-terminal hydrolase-L1 (UCHL1) gene were reported to have neurodegeneration and motor neuron dysfunction with upper motor neuron involvement. To investigate the role of UCHL1 on CSMN health and stability, we used both in vivo and in vitro approaches, and took advantage of the Uchl1nm3419 (UCHL1−/−) mice, which lack all UCHL1 function. We report a unique role of UCHL1 in maintaining CSMN viability and cellular integrity. CSMN show early, selective, progressive, and profound cell loss in the absence of UCHL1. CSMN degeneration, evident even at pre-symptomatic stages by disintegration of the apical dendrite and spine loss, is mediated via increased ER stress. These findings bring a novel understanding to the basis of CSMN vulnerability, and suggest UCHL1−/− mice as a tool to study CSMN pathology. PMID:25596590

  19. Feasibility assessment of a tunnel-ventilated, water-padded barn on alleviation of heat stress for lactating Holstein cows in a humid area.

    PubMed

    Shiao, T F; Chen, J C; Yang, D W; Lee, S N; Lee, C F; Cheng, W T K

    2011-11-01

    The use of evaporative cooling for mitigating heat stress in lactating cows in humid areas is controversial. In Taiwan, Holstein cow performance is significantly restricted by hot and humid weather. This study investigated the efficacy of using a tunnel-ventilated, water-padded freestall (TP) barn for reducing heat stress in lactating cows. From August to October 2006, 36 cows allocated in a 3×3 Latin square were raised in 3 barn cooling treatments: a conventional freestall barn with fans and sprinklers in the feed line (Fan+SP, control), a TP barn, and a TP barn with sprinkler cooling (TP+SP). Daytime air speeds in the 3 barns were 1.23, 2.38, and 2.06 m/s, respectively. Both TP barns were more efficient than the control in reducing the daytime temperature and temperature-humidity index. The barn temperature was <26°C for an extra 4.2h per day, but the relative humidity was >96% in both TP barns. Cows in both TP barns had higher respiration rates and skin temperatures at 0300 h than cows in the Fan+SP barn. The TP environment increased the cows' serum cholesterol level and the activities of alkaline phosphatase and alanine aminotransferase, but blood partial pressure of CO(2) was not affected. Vaginal temperature was persistently high in cows in the TP barn; in the 2 SP barns, it decreased 0.4 to 0.6°C following sprinkling and milking. The intake activity and rumen digestion of cows raised in the 3 environments were similar. Cows in both TP barns ingested more dry matter. Cows in the TP+SP barn tended to produce more milk than those in the Fan+SP barn (25.4 vs. 24.7 kg). Although heat stress was not completely alleviated in these 3 barns, the TP+SP treatment resolved the negative effect of a previous TP barn built in 2004 on intake and milk yield by increasing air speed and using sprinkler cooling. Thus, it is expected that TP+SP barns will be beneficial in regions with high humidity. Adequate air speed and sprinkler cooling are likely to be key factors for

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

    PubMed

    Li, Ying; Li, Jia; Li, Shanshan; Li, Yi; Wang, Xiangxiang; Liu, Baolin; Fu, Qiang; Ma, Shiping

    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. PMID:25791922

  1. N-Myristoyltransferase Inhibition Induces ER-Stress, Cell Cycle Arrest, and Apoptosis in Cancer Cells

    PubMed Central

    2016-01-01

    N-Myristoyltransferase (NMT) covalently attaches a C14 fatty acid to the N-terminal glycine of proteins and has been proposed as a therapeutic target in cancer. We have recently shown that selective NMT inhibition leads to dose-responsive loss of N-myristoylation on more than 100 protein targets in cells, and cytotoxicity in cancer cells. N-myristoylation lies upstream of multiple pro-proliferative and oncogenic pathways, but to date the complex substrate specificity of NMT has limited determination of which diseases are most likely to respond to a selective NMT inhibitor. We describe here the phenotype of NMT inhibition in HeLa cells and show that cells die through apoptosis following or concurrent with accumulation in the G1 phase. We used quantitative proteomics to map protein expression changes for more than 2700 proteins in response to treatment with an NMT inhibitor in HeLa cells and observed down-regulation of proteins involved in cell cycle regulation and up-regulation of proteins involved in the endoplasmic reticulum stress and unfolded protein response, with similar results in breast (MCF-7, MDA-MB-231) and colon (HCT116) cancer cell lines. This study describes the cellular response to NMT inhibition at the proteome level and provides a starting point for selective targeting of specific diseases with NMT inhibitors, potentially in combination with other targeted agents. PMID:27267252

  2. N-Myristoyltransferase Inhibition Induces ER-Stress, Cell Cycle Arrest, and Apoptosis in Cancer Cells.

    PubMed

    Thinon, Emmanuelle; Morales-Sanfrutos, Julia; Mann, David J; Tate, Edward W

    2016-08-19

    N-Myristoyltransferase (NMT) covalently attaches a C14 fatty acid to the N-terminal glycine of proteins and has been proposed as a therapeutic target in cancer. We have recently shown that selective NMT inhibition leads to dose-responsive loss of N-myristoylation on more than 100 protein targets in cells, and cytotoxicity in cancer cells. N-myristoylation lies upstream of multiple pro-proliferative and oncogenic pathways, but to date the complex substrate specificity of NMT has limited determination of which diseases are most likely to respond to a selective NMT inhibitor. We describe here the phenotype of NMT inhibition in HeLa cells and show that cells die through apoptosis following or concurrent with accumulation in the G1 phase. We used quantitative proteomics to map protein expression changes for more than 2700 proteins in response to treatment with an NMT inhibitor in HeLa cells and observed down-regulation of proteins involved in cell cycle regulation and up-regulation of proteins involved in the endoplasmic reticulum stress and unfolded protein response, with similar results in breast (MCF-7, MDA-MB-231) and colon (HCT116) cancer cell lines. This study describes the cellular response to NMT inhibition at the proteome level and provides a starting point for selective targeting of specific diseases with NMT inhibitors, potentially in combination with other targeted agents. PMID:27267252

  3. Treatment with bone marrow mesenchymal stem cells combined with plumbagin alleviates spinal cord injury by affecting oxidative stress, inflammation, apoptotis and the activation of the Nrf2 pathway.

    PubMed

    Yang, Wencheng; Yang, Yan; Yang, Jian-Yi; Liang, Ming; Song, Jiangtao

    2016-04-01

    The aim of the present study was to investigate the protective effect exerted by bone marrow mesenchymal stem cells (BMSCs) in combination with plumbagin on spinal cord injury (SCI) and explore the mechanism behind this protective effect. Firstly, BMSCs were extracted from male Sprague-Dawley rats, cultured in vitro, and identified by hematoxylin. Sprague-Dawley rats were then randomly divided into a control group, SCI model group, BMSC-treated group, a plumbagin-treated group, and a BMSC and plumbagin-treated group. After treatment with BMSCs combined with plumbagin, a Basso, Beattie and Bresnahan (BBB) test was carried out and the spinal cord water content was examined in order to analyze the effect of BMSCs combined with plumbagin on SCI. The myeloperoxidase (MPO), superoxide dismutase (SOD), malondialdehyde (MDA), nuclear factor-κB (NF-κB) p65 unit, tumor necrosis factor-α (TNF-α) levels were also detected. Moreover, nuclear factor erythroid 2‑related factor 2 (Nrf2), phosphoinositide 3-kinase (PI3K), phosphorylated (p-)Akt, p-p38 mitogen-activated protein kinase (MAPK), and p-extracellular-signal-regulated kinase (ERK) protein expression levels were measured using western blot analysis. Treatment with BMSCs combined with plumbagin significantly improved locomotor recovery and reduced the spinal cord water content after SCI. The increased MPO, MDA, NF-κB p65 and TNF-α levels were significantly suppressed and the decreased SOD was significantly increased in SCI rats. The suppression of Nrf2, p-Akt and p-ERK, as well as the promotion of p-p38 MAPK, were reversed by treatment with BMSCs combined with plumbagin. These effects suggest that treatment with BMSCs combined with plumbagin alleviates SCI through its effects on oxidative stress, inflammation, apoptotis and activation of the Nrf2 pathway. PMID:26936518

  4. Genome Analysis of Pseudomonas fluorescens PCL1751: A Rhizobacterium that Controls Root Diseases and Alleviates Salt Stress for Its Plant Host

    PubMed Central

    Cho, Shu-Ting; Chang, Hsing-Hua; Egamberdieva, Dilfuza; Kamilova, Faina; Lugtenberg, Ben; Kuo, Chih-Horng

    2015-01-01

    Pseudomonas fluorescens PCL1751 is a rod-shaped Gram-negative bacterium isolated from the rhizosphere of a greenhouse-grown tomato plant in Uzbekistan. It controls several plant root diseases caused by Fusarium fungi through the mechanism of competition for nutrients and niches (CNN). This mechanism does not rely on the production of antibiotics, so it avoids the concerns of resistance development and is environmentally safe. Additionally, this bacterium promotes plant growth by alleviating salt stress for its plant host. To investigate the genetic mechanisms that may explain these observations, we determined the complete genome sequence of this bacterium, examined its gene content, and performed comparative genomics analysis with other Pseudomonas strains. The genome of P. fluorescens PCL1751 consisted of one circular chromosome that is 6,143,950 base-pairs (bp) in size; no plasmid was found. The annotation included 19 rRNA, 70 tRNA, and 5,534 protein-coding genes. The gene content analysis identified a large number of genes involved in chemotaxis and motility, colonization of the rhizosphere, siderophore biosynthesis, and osmoprotectant production. In contrast, the pathways involved in the biosynthesis of phytohormones or antibiotics were not found. Comparison with other Pseudomonas genomes revealed extensive variations in their genome size and gene content. The presence and absence of secretion system genes were highly variable. As expected, the synteny conservation among strains decreased as a function of phylogenetic divergence. The integration of prophages appeared to be an important driver for genome rearrangements. The whole-genome gene content analysis of this plant growth-promoting rhizobacterium (PGPR) provided some genetic explanations to its phenotypic characteristics. The extensive and versatile substrate utilization pathways, together with the presence of many genes involved in competitive root colonization, provided further support for the finding

  5. Long Chain Omega-3 Polyunsaturated Fatty Acid Supplementation Alleviates Doxorubicin-Induced Depressive-Like Behaviors and Neurotoxicity in Rats: Involvement of Oxidative Stress and Neuroinflammation.

    PubMed

    Wu, Yan-Qin; Dang, Rui-Li; Tang, Mi-Mi; Cai, Hua-Lin; Li, Huan-De; Liao, De-Hua; He, Xin; Cao, Ling-Juan; Xue, Ying; Jiang, Pei

    2016-04-23

    Doxorubicin (DOX) is a chemotherapeutic agent widely used in human malignancies. Its long-term use can cause neurobiological side-effects associated with depression. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), the essential fatty acids found in fish oil, possess neuroprotecitve and antidepressant activities. Thus, the aim of this study was to explore the potential protective effects of ω-3 PUFAs against DOX-induced behavioral changes and neurotoxicity. ω-3 PUFAs were given daily by gavage (1.5 g/kg) over three weeks starting seven days before DOX administration (2.5 mg/kg). Open-field test (OFT) and forced swimming test (FST) were conducted to assess exploratory activity and despair behavior, respectively. Our data showed that ω-3 PUFAs supplementation significantly mitigated the behavioral changes induced by DOX. ω-3 PUFAs pretreatment also alleviated the DOX-induced neural apoptosis. Meanwhile, ω-3 PUFAs treatment ameliorated DOX-induced oxidative stress in the prefrontal cortex and hippocampus. Additionally, gene expression of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α, and the protein levels of NF-κB and iNOS were significantly increased in brain tissues of DOX-treated group, whereas ω-3 PUFAs supplementation significantly attenuated DOX-induced neuroinflammation. In conclusion, ω-3 PUFAs can effectively protect against DOX-induced depressive-like behaviors, and the mechanisms underlying the neuroprotective effect are potentially associated with its anti-oxidant, anti-inflammatory, and anti-apoptotic properties.

  6. Genome Analysis of Pseudomonas fluorescens PCL1751: A Rhizobacterium that Controls Root Diseases and Alleviates Salt Stress for Its Plant Host.

    PubMed

    Cho, Shu-Ting; Chang, Hsing-Hua; Egamberdieva, Dilfuza; Kamilova, Faina; Lugtenberg, Ben; Kuo, Chih-Horng

    2015-01-01

    Pseudomonas fluorescens PCL1751 is a rod-shaped Gram-negative bacterium isolated from the rhizosphere of a greenhouse-grown tomato plant in Uzbekistan. It controls several plant root diseases caused by Fusarium fungi through the mechanism of competition for nutrients and niches (CNN). This mechanism does not rely on the production of antibiotics, so it avoids the concerns of resistance development and is environmentally safe. Additionally, this bacterium promotes plant growth by alleviating salt stress for its plant host. To investigate the genetic mechanisms that may explain these observations, we determined the complete genome sequence of this bacterium, examined its gene content, and performed comparative genomics analysis with other Pseudomonas strains. The genome of P. fluorescens PCL1751 consisted of one circular chromosome that is 6,143,950 base-pairs (bp) in size; no plasmid was found. The annotation included 19 rRNA, 70 tRNA, and 5,534 protein-coding genes. The gene content analysis identified a large number of genes involved in chemotaxis and motility, colonization of the rhizosphere, siderophore biosynthesis, and osmoprotectant production. In contrast, the pathways involved in the biosynthesis of phytohormones or antibiotics were not found. Comparison with other Pseudomonas genomes revealed extensive variations in their genome size and gene content. The presence and absence of secretion system genes were highly variable. As expected, the synteny conservation among strains decreased as a function of phylogenetic divergence. The integration of prophages appeared to be an important driver for genome rearrangements. The whole-genome gene content analysis of this plant growth-promoting rhizobacterium (PGPR) provided some genetic explanations to its phenotypic characteristics. The extensive and versatile substrate utilization pathways, together with the presence of many genes involved in competitive root colonization, provided further support for the finding

  7. Exogenous IAA differentially affects growth, oxidative stress and antioxidants system in Cd stressed Trigonella foenum-graecum L. seedlings: Toxicity alleviation by up-regulation of ascorbate-glutathione cycle.

    PubMed

    Bashri, Gausiya; Prasad, Sheo Mohan

    2016-10-01

    In the present study, effect of exogenous indole-3-acetic acid at their different levels (i.e. low; IAAL, 10µM and high; IAAH, 100µM) were studied on growth, oxidative stress biomarkers and antioxidant enzymes (SOD, POD, CAT and GST), and metabolites (AsA and GSH) as well as enzymes (APX, GR and DHAR) of ascorbate-glutathione cycle in Trigonella foenum-graecum L. seedlings grown under cadmium (Cd1, 3mgCd kg(-1) soil and Cd2, 9mgCd kg(-1) soil) stress. Cadmium (Cd) at both doses caused reduction in growth which was correlated with enhanced lipid peroxidation and damage to membrane as a result of excess accumulation of O2(•-) and H2O2. Cd also enhanced the oxidation of AsA and GSH to DHA and GSSG, respectively which give a clear sign of oxidative stress, despite of accelerated activity of enzymatic antioxidants: SOD, CAT, POD, GST as well as APX, DHAR (except in Cd2 stress) and GR. Exogenous application of IAAL resulted further rise in the activities of these enzymes, and maintained the redox status (> ratios: AsA/DHA and GSH/GSSG) of cells. The maintained redox status of cells under IAAL treatment declined the level of ROS in Cd1 and Cd2 treated seedlings thereby alleviated the Cd toxicity and this effect was more pronounced under Cd1 stress. Contrary to this, exogenous IAAH suppressed the activity of DHAR and GR and disturbed the redox status (< ratios: AsA/DHA and GSH/GSSG) of cells, hence excess accumulation of ROS further aggravated the Cd induced damage. Thus, overall results suggest that IAA at low (IAAL) and high (IAAH) doses affected the Cd toxicity differently by regulating the ascorbate-glutathione cycle as well as activity of other antioxidants in Trigonella seedlings. PMID:27344401

  8. Deficiency of autophagy protein Map1-LC3b mediates IL-17-dependent lung pathology during respiratory viral infection via ER stress associated IL-1

    PubMed Central

    Reed, Michelle; Morris, Susan H.; Owczarczyk, Anna B.; Lukacs, Nicholas W.

    2015-01-01

    While recent studies suggest that IL-1β production is modulated by macroautophagy or sensors of ER stress upon pro-inflammatory insult, autophagy and IL-1β production during viral infection has not been fully investigated. This was addressed using respiratory syncytial virus (RSV), which is associated with lung immunopathology, IL-1, and IL-17a secretion in severely infected patients. Mice deficient in the autophagy-associated protein Map1-LC3b (LC3b−/−) developed increased IL-17a-dependent lung pathology upon infection. RSV-infected LC3b−/− DCs fail to upregulate autophagosome formation, secrete IL-1β and IL-6, and elicit IL-17a production from CD4+ T cells. Bone marrow chimeras revealed both structural and hematopoietic LC3b deficiency contribute to the development of IL-17a-dependent lung pathology in vivo. Further investigation revealed airway epithelium as the primary source of IL-1β during infection, while inhibition of the ER-stress sensor IRE-1 in primary airway epithelial cells reduced IL-1β production identifying a primary ER stress pathway. Finally, blockade of IL-1 receptor signaling in RSV-infected LC3b−/− mice abolished IL-17a-dependent lung pathology. These findings provide novel mechanistic insight into the contribution of autophagy- and ER stress-dependent cytokine production that initiate and maintain aberrant Th17 responses, while identifying IL-1 as a potential therapeutic target in the treatment of severe respiratory viral infections. PMID:25669150

  9. Deficiency of autophagy protein Map1-LC3b mediates IL-17-dependent lung pathology during respiratory viral infection via ER stress-associated IL-1.

    PubMed

    Reed, M; Morris, S H; Owczarczyk, A B; Lukacs, N W

    2015-09-01

    While recent studies suggest that interleukin (IL)-1β production is modulated by macroautophagy or sensors of endoplasmic reticulum (ER) stress upon pro-inflammatory insult, autophagy and IL-1β production during viral infection has not been fully investigated. This was addressed using respiratory syncytial virus (RSV), which is associated with lung immunopathology, IL-1, and IL-17a secretion in severely infected patients. Mice deficient in the autophagy-associated protein Map1-LC3b (LC3b(-/-)) developed increased IL-17a-dependent lung pathology upon infection. RSV-infected LC3b(-/-) dendritic cells (DCs) fail to upregulate autophagosome formation, secrete IL-1β and IL-6, and elicit IL-17a production from CD4+ T cells. Bone marrow chimeras revealed that both structural and hematopoietic LC3b deficiency contribute to the development of IL-17a-dependent lung pathology in vivo. Further investigation revealed airway epithelium as the primary source of IL-1β during infection, whereas inhibition of the ER-stress sensor inositol-requiring protein-1 in primary airway epithelial cells reduced IL-1β production identifying a primary ER stress pathway. Finally, blockade of IL-1 receptor signaling in RSV-infected LC3b(-/-) mice abolished IL-17a-dependent lung pathology. These findings provide novel mechanistic insight into the contribution of autophagy- and ER stress-dependent cytokine production that initiate and maintain aberrant Th17 responses, while identifying IL-1 as a potential therapeutic target in the treatment of severe respiratory viral infections. PMID:25669150

  10. Melatonin set out to ER stress signaling thwarts epithelial mesenchymal transition and peritoneal dissemination via calpain-mediated C/EBPβ and NFκB cleavage.

    PubMed

    Wu, Sheng-Mao; Lin, Wan-Yu; Shen, Chin-Chang; Pan, Hung-Chuan; Keh-Bin, Wang; Chen, Yi-Ching; Jan, Yee-Jee; Lai, De-Wei; Tang, Shu-Ching; Tien, Hsing-Ru; Chiu, Chien-Shan; Tsai, Tsung-Chih; Lai, Yi-Liang; Sheu, Meei-Ling

    2016-03-01

    Peritoneal dissemination of tumor has high mortality and is associated with the loss of epithelial features, acquisition of motile mesenchymal morphology characteristics, and invasive properties by tumor cells. Melatonin is an endogenously produced molecule in all plant species that is known to exert antitumor activity, but to date, its underlying mechanisms and antiperitoneal metastasis efficacy is not well defined. This study determined the antiperitoneal dissemination potential of melatonin in vivo and assessed its association with the inhibition of epithelial-to-mesenchymal transition (EMT) signaling mechanism by endoplasmic reticulum (ER) stress, which may be a major molecular mechanism of melatonin against cancer. The results demonstrate that melatonin inhibited peritoneal metastasis in vivo and activated ER stress in Cignal ERSE Reporter Assay, organelle structure in transmission electron microscopy images, calpain activity, and protein biomarkers like p-elf2α. Moreover, the overexpression of transcription factor C/EBPβ in gastric cancer interacted with NFκB and further regulates COX-2 expression. These were dissociated and downregulated by melatonin, as proven by immunofluorescence imaging, immunoprecipitation, EMSA, and ChIP assay. Melatonin or gene silencing of C/EBPβ decreased the EMT protein markers (E-cadherin, Snail, and Slug) and Wnt/beta-catenin activity by Topflash activity, and increased ER stress markers. In an animal study, the results of melatonin therapy were consistent with those of in vitro findings and attenuated systemic proangiogenesis factor production. In conclusion, C/EBPβ and NFκB inhibition by melatonin may impede both gastric tumor growth and peritoneal dissemination by inducing ER stress and inhibiting EMT. PMID:26514342

  11. Melatonin set out to ER stress signaling thwarts epithelial mesenchymal transition and peritoneal dissemination via calpain-mediated C/EBPβ and NFκB cleavage.

    PubMed

    Wu, Sheng-Mao; Lin, Wan-Yu; Shen, Chin-Chang; Pan, Hung-Chuan; Keh-Bin, Wang; Chen, Yi-Ching; Jan, Yee-Jee; Lai, De-Wei; Tang, Shu-Ching; Tien, Hsing-Ru; Chiu, Chien-Shan; Tsai, Tsung-Chih; Lai, Yi-Liang; Sheu, Meei-Ling

    2016-03-01

    Peritoneal dissemination of tumor has high mortality and is associated with the loss of epithelial features, acquisition of motile mesenchymal morphology characteristics, and invasive properties by tumor cells. Melatonin is an endogenously produced molecule in all plant species that is known to exert antitumor activity, but to date, its underlying mechanisms and antiperitoneal metastasis efficacy is not well defined. This study determined the antiperitoneal dissemination potential of melatonin in vivo and assessed its association with the inhibition of epithelial-to-mesenchymal transition (EMT) signaling mechanism by endoplasmic reticulum (ER) stress, which may be a major molecular mechanism of melatonin against cancer. The results demonstrate that melatonin inhibited peritoneal metastasis in vivo and activated ER stress in Cignal ERSE Reporter Assay, organelle structure in transmission electron microscopy images, calpain activity, and protein biomarkers like p-elf2α. Moreover, the overexpression of transcription factor C/EBPβ in gastric cancer interacted with NFκB and further regulates COX-2 expression. These were dissociated and downregulated by melatonin, as proven by immunofluorescence imaging, immunoprecipitation, EMSA, and ChIP assay. Melatonin or gene silencing of C/EBPβ decreased the EMT protein markers (E-cadherin, Snail, and Slug) and Wnt/beta-catenin activity by Topflash activity, and increased ER stress markers. In an animal study, the results of melatonin therapy were consistent with those of in vitro findings and attenuated systemic proangiogenesis factor production. In conclusion, C/EBPβ and NFκB inhibition by melatonin may impede both gastric tumor growth and peritoneal dissemination by inducing ER stress and inhibiting EMT.

  12. Effects of dietary arginine and glutamine on alleviating the impairment induced by deoxynivalenol stress and immune relevant cytokines in growing pigs.

    PubMed

    Wu, Li; Wang, Wence; Yao, Kang; Zhou, Ting; Yin, Jie; Li, Tiejun; Yang, Lin; He, Liuqin; Yang, Xiaojian; Zhang, Hongfu; Wang, Qi; Huang, Ruilin; Yin, Yulong

    2013-01-01

    glutamine on alleviating the impairment induced by DON stress and immune relevant cytokines in growing pigs.

  13. Retinoic Acid Induced-Autophagic Flux Inhibits ER-Stress Dependent Apoptosis and Prevents Disruption of Blood-Spinal Cord Barrier after Spinal Cord Injury

    PubMed Central

    Zhou, Yulong; Zhang, Hongyu; Zheng, Binbin; Ye, Libing; Zhu, Sipin; Johnson, Noah R; Wang, Zhouguang; Wei, Xiaojie; Chen, Daqing; Cao, Guodong; Fu, Xiaobing; Li, Xiaokun; Xu, Hua-Zi; Xiao, Jian

    2016-01-01