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Sample records for autophagy potential implications

  1. Autophagy in breast cancer and its implications for therapy

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    Jain, Kirti; Paranandi, Krishna S; Sridharan, Savitha; Basu, Alakananda

    2013-01-01

    Autophagy is an evolutionarily conserved process of cellular self-digestion that serves as a mechanism to clear damaged organelles and recycle nutrients. Since autophagy can promote cell survival as well as cell death, it has been linked to different human pathologies, including cancer. Although mono-allelic deletion of autophagy-related gene BECN1 in breast tumors originally indicated a tumor suppressive role for autophagy in breast cancer, the intense research during the last decade suggests a role for autophagy in tumor progression. It is now recognized that tumor cells often utilize autophagy to survive various stresses, such as oncogene-induced transformation, hypoxia, endoplasmic reticulum (ER) stress and extracellular matrix detachment. Induction of autophagy by tumor cells may also contribute to tumor dormancy and resistance to anticancer therapies, thus making autophagy inhibitors promising drug candidates for breast cancer treatment. The scientific endeavors continue to define a precise role for autophagy in breast cancer. In this article, we review the current literature on the role of autophagy during the development and progression of breast cancer, and discuss the potential of autophagy modulators for breast cancer treatment. PMID:23841025

  2. Inhibition of autophagy initiation potentiates chemosensitivity in mesothelioma.

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    Follo, Carlo; Cheng, Yao; Richards, William G; Bueno, Raphael; Broaddus, Virginia Courtney

    2018-03-01

    The benefits of inhibiting autophagy in cancer are still controversial, with differences in outcome based on the type of tumor, the context and the particular stage of inhibition. Here, we investigated the impact of inhibiting autophagy at different stages on chemosensitivity using 3-dimensional (3D) models of mesothelioma, including ex vivo human tumor fragment spheroids. As shown by LC3B accumulation, we successfully inhibited autophagy using either an early stage ULK1/2 inhibitor (MRT 68921) or a late stage inhibitor (hydroxychloroquine). We found that inhibition of autophagy at the early stage, but not at late stage, potentiated chemosensitivity. This effect was seen only in those spheroids with high autophagy and active initiation at steady state. Inhibition of autophagy alone, at either early or late stage, did not cause cell death, showing that the inhibitors were non-toxic and that mesothelioma did not depend on autophagy at baseline, at least over 24 h. Using ATG13 puncta analysis, we found that autophagy initiation identified tumors that are more chemosensitive at baseline and after autophagy inhibition. Our results highlight a potential role of autophagy initiation in supporting mesothelioma cells during chemotherapy. Our work also highlights the importance of testing the inhibition of different stages in order to uncover the role of autophagy and the potential of its modulation in the treatment of cancer. © 2017 Wiley Periodicals, Inc.

  3. Restarting stalled autophagy a potential therapeutic approach for the lipid storage disorder, Niemann-Pick type C1 disease.

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    Sarkar, Sovan; Maetzel, Dorothea; Korolchuk, Viktor I; Jaenisch, Rudolf

    2014-06-01

    Autophagy is essential for cellular homeostasis and its dysfunction in human diseases has been implicated in the accumulation of misfolded protein and in cellular toxicity. We have recently shown impairment in autophagic flux in the lipid storage disorder, Niemann-Pick type C1 (NPC1) disease associated with abnormal cholesterol sequestration, where maturation of autophagosomes is impaired due to defective amphisome formation caused by failure in SNARE machinery. Abrogation of autophagy also causes cholesterol accumulation, suggesting that defective autophagic flux in NPC1 disease may act as a primary causative factor not only by imparting its deleterious effects, but also by increasing cholesterol load. However, cholesterol depletion treatment with HP-β-cyclodextrin impedes autophagy, whereas pharmacologically stimulating autophagy restores its function independent of amphisome formation. Of potential therapeutic relevance is that a low dose of HP-β-cyclodextrin that does not perturb autophagy, coupled with an autophagy inducer, may rescue both the cholesterol and autophagy defects in NPC1 disease.

  4. Autophagy as a potential target for sarcoma treatment.

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    Min, Li; Choy, Edwin; Pollock, Raphael E; Tu, Chongqi; Hornicek, Francis; Duan, Zhenfeng

    2017-08-01

    Autophagy is a constitutively active, evolutionary conserved, catabolic process for maintaining homeostasis in cellular stress responses and cell survival. Although its mechanism has not been fully illustrated, recent work on autophagy in various types of sarcomas has demonstrated that autophagy exerts an important role in sarcoma cell growth and proliferation, in pro-survival response to therapies and stresses, and in therapeutic resistance of sarcoma. Thus, the autophagic process is being seen as a possibly novel therapeutic target of sarcoma. Additionally, some co-regulators of autophagy have also been investigated as promising biomarkers for the diagnosis and prognosis of sarcoma. In this review, we summarize contemporary advances in the role of autophagy in sarcoma and discuss the potential of autophagy as a new target for sarcoma treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The Role of Reactive Oxygen Species and Autophagy in Periodontitis and Their Potential Linkage

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    Chengcheng Liu

    2017-06-01

    Full Text Available Periodontitis is a chronic inflammatory disease that causes damage to periodontal tissues, which include the gingiva, periodontal ligament, and alveolar bone. The major cause of periodontal tissue destruction is an inappropriate host response to microorganisms and their products. Specifically, a homeostatic imbalance between reactive oxygen species (ROS and antioxidant defense systems has been implicated in the pathogenesis of periodontitis. Elevated levels of ROS acting as intracellular signal transducers result in autophagy, which plays a dual role in periodontitis by promoting cell death or blocking apoptosis in infected cells. Autophagy can also regulate ROS generation and scavenging. Investigations are ongoing to elucidate the crosstalk mechanisms between ROS and autophagy. Here, we review the physiological and pathological roles of ROS and autophagy in periodontal tissues. The redox-sensitive pathways related to autophagy, such as mTORC1, Beclin 1, and the Atg12-Atg5 complex, are explored in depth to provide a comprehensive overview of the crosstalk between ROS and autophagy. Based on the current evidence, we suggest that a potential linkage between ROS and autophagy is involved in the pathogenesis of periodontitis.

  6. Blue-Print Autophagy: Potential for Cancer Treatment

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    Nadia Ruocco

    2016-07-01

    Full Text Available The marine environment represents a very rich source of biologically active compounds with pharmacological applications. This is due to its chemical richness, which is claiming considerable attention from the health science communities. In this review we give a general overview on the marine natural products involved in stimulation and inhibition of autophagy (a type of programmed cell death linked to pharmacological and pathological conditions. Autophagy represents a complex multistep cellular process, wherein a double membrane vesicle (the autophagosome captures organelles and proteins and delivers them to the lysosome. This natural and destructive mechanism allows the cells to degrade and recycle its cellular components, such as amino acids, monosaccharides, and lipids. Autophagy is an important mechanism used by cells to clear pathogenic organism and deal with stresses. Therefore, it has also been implicated in several diseases, predominantly in cancer. In fact, pharmacological stimulation or inhibition of autophagy have been proposed as approaches to develop new therapeutic treatments of cancers. In conclusion, this blue-print autophagy (so defined because it is induced and/or inhibited by marine natural products represents a new strategy for the future of biomedicine and of biotechnology in cancer treatment.

  7. New Potential Pharmacological Functions of Chinese Herbal Medicines via Regulation of Autophagy

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    Betty Yuen Kwan Law

    2016-03-01

    Full Text Available Autophagy is a universal catabolic cellular process for quality control of cytoplasm and maintenance of cellular homeostasis upon nutrient deprivation and environmental stimulus. It involves the lysosomal degradation of cellular components such as misfolded proteins or damaged organelles. Defects in autophagy are implicated in the pathogenesis of diseases including cancers, myopathy, neurodegenerations, infections and cardiovascular diseases. In the recent decade, traditional drugs with new clinical applications are not only commonly found in Western medicines, but also highlighted in Chinese herbal medicines (CHM. For instance, pharmacological studies have revealed that active components or fractions from Chaihu (Radix bupleuri, Hu Zhang (Rhizoma polygoni cuspidati, Donglingcao (Rabdosia rubesens, Hou po (Cortex magnoliae officinalis and Chuan xiong (Rhizoma chuanxiong modulate cancers, neurodegeneration and cardiovascular disease via autophagy. These findings shed light on the potential new applications and formulation of CHM decoctions via regulation of autophagy. This article reviews the roles of autophagy in the pharmacological actions of CHM and discusses their new potential clinical applications in various human diseases.

  8. Autophagy in Inflammatory Diseases

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    Alexander J. S. Choi

    2011-01-01

    Full Text Available Autophagy provides a mechanism for the turnover of cellular organelles and proteins through a lysosome-dependent degradation pathway. During starvation, autophagy exerts a homeostatic function that promotes cell survival by recycling metabolic precursors. Additionally, autophagy can interact with other vital processes such as programmed cell death, inflammation, and adaptive immune mechanisms, and thereby potentially influence disease pathogenesis. Macrophages deficient in autophagic proteins display enhanced caspase-1-dependent proinflammatory cytokine production and the activation of the inflammasome. Autophagy provides a functional role in infectious diseases and sepsis by promoting intracellular bacterial clearance. Mutations in autophagy-related genes, leading to loss of autophagic function, have been implicated in the pathogenesis of Crohn's disease. Furthermore, autophagy-dependent mechanisms have been proposed in the pathogenesis of several pulmonary diseases that involve inflammation, including cystic fibrosis and pulmonary hypertension. Strategies aimed at modulating autophagy may lead to therapeutic interventions for diseases associated with inflammation.

  9. Association of CHMP4B and Autophagy with Micronuclei: Implications for Cataract Formation

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    Antonia P. Sagona

    2014-01-01

    Full Text Available Autophagy is a mechanism of cellular self-degradation that is very important for cellular homeostasis and differentiation. Components of the endosomal sorting complex required for transport (ESCRT machinery are required for endosomal sorting and also for autophagy and the completion of cytokinesis. Here we show that the ESCRT-III subunit CHMP4B not only localizes to normal cytokinetic bridges but also to chromosome bridges and micronuclei, the latter surrounded by lysosomes and autophagosomes. Moreover, CHMP4B can be co-immunoprecipitated with chromatin. Interestingly, a CHMP4B mutation associated with autosomal dominant posterior polar cataract abolishes the ability of CHMP4B to localize to micronuclei. We propose that CHMP4B, through its association with chromatin, may participate in the autophagolysosomal degradation of micronuclei and other extranuclear chromatin. This may have implications for DNA degradation during lens cell differentiation, thus potentially protecting lens cells from cataract development.

  10. Autophagy in the eye: implications for ocular cell health.

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    Frost, Laura S; Mitchell, Claire H; Boesze-Battaglia, Kathleen

    2014-07-01

    Autophagy, a catabolic process by which a cell "eats" itself, turning over its own cellular constituents, plays a key role in cellular homeostasis. In an effort to maintain normal cellular function, autophagy is often up-regulated in response to environmental stresses and excessive organelle damage to facilitate aggregated protein removal. In the eye, virtually all cell types from those comprising the cornea in the front of the eye to the retinal pigment epithelium (RPE) providing a protective barrier for the retina at the back of the eye, rely on one or more aspects of autophagy to maintain structure and/or normal physiological function. In the lens autophagy plays a critical role in lens fiber cell maturation and the formation of the organelle free zone. Numerous studies delineating the role of Atg5, Vsp34 as well as FYCO1 in maintenance of lens transparency are discussed. Corneal endothelial dystrophies are also characterized as having elevated levels of autophagic proteins. Therefore, novel modulators of autophagy such as lithium and melatonin are proposed as new therapeutic strategies for this group of dystrophies. In addition, we summarize how corneal Herpes Simplex Virus (HSV-1) infection subverts the cornea's response to infection by inhibiting the normal autophagic response. Using glaucoma models we analyze the relative contribution of autophagy to cell death and cell survival. The cytoprotective role of autophagy is further discussed in an analysis of photoreceptor cell heath and function. We focus our analysis on the current understanding of autophagy in photoreceptor and RPE health, specifically on the diverse role of autophagy in rods and cones as well as its protective role in light induced degeneration. Lastly, in the RPE we highlight hybrid phagocytosis-autophagy pathways. This comprehensive review allows us to speculate on how alterations in various stages of autophagy contribute to glaucoma and retinal degenerations. Copyright © 2014 Elsevier Ltd

  11. Blue-Print Autophagy: Potential for Cancer Treatment

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    Nadia Ruocco; Susan Costantini; Maria Costantini

    2016-01-01

    The marine environment represents a very rich source of biologically active compounds with pharmacological applications. This is due to its chemical richness, which is claiming considerable attention from the health science communities. In this review we give a general overview on the marine natural products involved in stimulation and inhibition of autophagy (a type of programmed cell death) linked to pharmacological and pathological conditions. Autophagy represents a complex multistep cellu...

  12. Autophagy suppression potentiates the anti-glioblastoma effect of asparaginase in vitro and in vivo

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    Chen, Qicheng; Ye, Li; Fan, Jiajun; Zhang, Xuyao; Wang, Huan; Liao, Siyang; Song, Ping; Wang, Ziyu; Wang, Shaofei; Li, Yubin; Luan, Jingyun; Wang, Yichen; Chen, Wei; Zai, Wenjing; Yang, Ping; Cao, Zhonglian; Ju, Dianwen

    2017-01-01

    Asparaginase has been reported to be effective in the treatment of various leukemia and several malignant solid cancers. However, the anti-tumor effect of asparaginase is always restricted due to complicated mechanisms. Herein, we investigated the mechanisms of how glioblastoma resisted asparaginase treatment and reported a novel approach to enhance the anti-glioblastoma effect of asparaginase. We found that asparaginase could induce growth inhibition and caspase-dependent apoptosis in U87MG/U251MG glioblastoma cells. Meanwhile, autophagy was activated as indicated by autophagosomes formation and upregulated expression of LC3-II. Importantly, abolishing autophagy using chloroquine (CQ) and LY294002 enhanced the cytotoxicity and apoptosis induced by asparaginase in U87MG/U251MG cells. Further study proved that Akt/mTOR and Erk signaling pathways participated in autophagy induction, while reactive oxygen species (ROS) served as an intracellular regulator for both cytotoxicity and autophagy in asparaginase-treated U87MG/U251MG cells. Moreover, combination treatment with autophagy inhibitor CQ significantly enhanced anti-glioblastoma efficacy of asparaginase in U87MG cell xenograft model. Taken together, our results demonstrated that inhibition of autophagy potentiated the anti-tumor effect of asparagine depletion on glioblastoma, indicating that targeting autophagy and asparagine could be a potential approach for glioblastoma treatment. PMID:29207624

  13. Autophagy Therapeutic Potential of Garlic in Human Cancer Therapy

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    Yung-Lin Chu

    2013-07-01

    Full Text Available Cancer is one of the deadliest diseases against humans. To tackle this menace, humans have developed several high-technology therapies, such as chemotherapy, tomotherapy, targeted therapy, and antibody therapy. However, all these therapies have their own adverse side effects. Therefore, recent years have seen increased attention being given to the natural food for complementary therapy, which have less side effects. Garlic 大 蒜 Dà Suàn; Allium sativum, is one of most powerful food used in many of the civilizations for both culinary and medicinal purpose. In general, these foods induce cancer cell death by apoptosis, autophagy, or necrosis. Studies have discussed how natural food factors regulate cell survival or death by autophagy in cancer cells. From many literature reviews, garlic could not only induce apoptosis but also autophagy in cancer cells. Autophagy, which is called type-II programmed cell death, provides new strategy in cancer therapy. In conclusion, we wish that garlic could be the pioneer food of complementary therapy in clinical cancer treatment and increase the life quality of cancer patients.

  14. Wheat homologs of yeast ATG6 function in autophagy and are implicated in powdery mildew immunity.

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    Yue, Jieyu; Sun, Hong; Zhang, Wei; Pei, Dan; He, Yang; Wang, Huazhong

    2015-04-01

    Autophagy-related ATG6 proteins are pleiotropic proteins functioning in autophagy and the phosphatidylinositol 3-phosphate-signaling pathways. Arabidopsis ATG6 regulates normal plant growth, pollen development and germination, and plant responses to biotic/abiotic stresses. However, the ATG6 functions in wheat (Triticum aestivum L.), an important food crop, are lacking. We identified three members, TaATG6a-6c, of the ATG6 family from common wheat. TaATG6a, 6b and 6c were localized on homeologous chromosomes 3DL, 3BL and 3AL, respectively, of the allo-hexaploid wheat genome, and evidence was provided for their essential role in autophagy. The TaATG6a-GFP fusion protein was found in punctate pre-autophagosomal structures. The expression of each TaATG6 gene restored the accumulation of autophagic bodies in atg6-mutant yeast. Additionally, TaATG6 knockdown plants showed impaired constitutive and pathogen-induced autophagy and growth abnormalities under normal conditions. We also examined the expression patterns of wheat ATG6s for clues to their physiological roles, and found that their expression was induced by the fungus Blumeria graminis f. sp. tritici (Bgt), the causal agent of powdery mildew, and by abiotic stress factors. A role for TaATG6s in wheat immunity to powdery mildew was further implied when knockdowns of TaATG6s weakly compromised the broad-spectrum powdery mildew resistance gene Pm21-triggered resistance response and, conversely and significantly, enhanced the basal resistance of susceptible plants. In addition, leaf cell death was sometimes induced by growth-retarded small Bgt mycelia on susceptible TaATG6 knockdown plants after a long period of interaction. Thus, we provide an important extension of the previous characterization of plant ATG6 genes in wheat, and observed a role for autophagy genes in wheat immune responses to fungal pathogens. Three wheat ATG6s were identified and shown to be essential for autophagy biogenesis. Wheat ATG6s are

  15. Discordant signaling and autophagy response to fasting in hearts of obese mice: Implications for ischemia tolerance.

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    Andres, Allen M; Kooren, Joel A; Parker, Sarah J; Tucker, Kyle C; Ravindran, Nandini; Ito, Bruce R; Huang, Chengqun; Venkatraman, Vidya; Van Eyk, Jennifer E; Gottlieb, Roberta A; Mentzer, Robert M

    2016-07-01

    Autophagy is regulated by nutrient and energy status and plays an adaptive role during nutrient deprivation and ischemic stress. Metabolic syndrome (MetS) is a hypernutritive state characterized by obesity, dyslipidemia, elevated fasting blood glucose levels, and insulin resistance. It has also been associated with impaired autophagic flux and larger-sized infarcts. We hypothesized that diet-induced obesity (DIO) affects nutrient sensing, explaining the observed cardiac impaired autophagy. We subjected male friend virus B NIH (FVBN) mice to a high-fat diet, which resulted in increased weight gain, fat deposition, hyperglycemia, insulin resistance, and larger infarcts after myocardial ischemia-reperfusion. Autophagic flux was impaired after 4 wk on a high-fat diet. To interrogate nutrient-sensing pathways, DIO mice were subjected to overnight fasting, and hearts were processed for biochemical and proteomic analysis. Obese mice failed to upregulate LC3-II or to clear p62/SQSTM1 after fasting, although mRNA for LC3B and p62/SQSTM1 were appropriately upregulated in both groups, demonstrating an intact transcriptional response to fasting. Energy- and nutrient-sensing signal transduction pathways [AMPK and mammalian target of rapamycin (mTOR)] also responded appropriately to fasting, although mTOR was more profoundly suppressed in obese mice. Proteomic quantitative analysis of the hearts under fed and fasted conditions revealed broad changes in protein networks involved in oxidative phosphorylation, autophagy, oxidative stress, protein homeostasis, and contractile machinery. In many instances, the fasting response was quite discordant between lean and DIO mice. Network analysis implicated the peroxisome proliferator-activated receptor and mTOR regulatory nodes. Hearts of obese mice exhibited impaired autophagy, altered proteome, and discordant response to nutrient deprivation. Copyright © 2016 the American Physiological Society.

  16. The significance of autophagy in colorectal cancer pathogenesis and implications for therapy.

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    Lai, K; Killingsworth, M C; Lee, C S

    2014-10-01

    Colorectal cancer (CRC) is one of the most common cancers in developed countries with poor survival outcome in advanced stages of the disease due to its resistance to chemotherapy and other forms of treatment. New and alternative approaches are needed to overcome the tumour cells’ capacity for survival and to drive the tumour towards cell death. Autophagy is a mechanism involved in the elimination of damaged cellular components through lysosomal degradation and is capable of inducing programmed cell death. The process has recently gained much interest in understanding the pathogenesis of CRC and its potential for treatment of the disease due to its role in host protection and anticancer activity. This review describes and illustrates the fundamental mechanisms of autophagy, its importance as a prognostic marker and the current approaches to harness its protective and anticancer activity in CRC therapy.

  17. Inhibition of Autophagy Potentiates Atorvastatin-Induced Apoptotic Cell Death in Human Bladder Cancer Cells in Vitro

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    Kang, Minyong; Jeong, Chang Wook; Ku, Ja Hyeon; Kwak, Cheol; Kim, Hyeon Hoe

    2014-01-01

    Statins are cholesterol reduction agents that exhibit anti-cancer activity in several human cancers. Because autophagy is a crucial survival mechanism for cancer cells under stress conditions, cooperative inhibition of autophagy acts synergistically with other anti-cancer drugs. Thus, this study investigates whether combined treatment of atorvastatin and autophagy inhibitors results in enhancing the cytotoxic effects of atorvastatin, upon human bladder cancer cells, T24 and J82, in vitro. To measure cell viability, we performed the EZ-Cytox cell viability assay. We examined apoptosis by flow cytometry using annexin-V/propidium iodide (PI and western blot using procaspase-3 and poly (ADP-ribose) polymerase (PARP) antibodies. To examine autophagy activation, we evaluated the co-localization of LC3 and LysoTracker by immunocytochemistry, as well as the expression of LC3 and p62/sequestosome-1 (SQSTM1) by western blot. In addition, we assessed the survival and proliferation of T24 and J82 cells by a clonogenic assay. We found that atorvastatin reduced the cell viability of T24 and J82 cells via apoptotic cell death and induced autophagy activation, shown by the co-localization of LC3 and LysoTracker. Moreover, pharmacologic inhibition of autophagy significantly enhanced atorvastatin-induced apoptosis in T24 and J82 cells. In sum, inhibition of autophagy potentiates atorvastatin-induced apoptotic cell death in human bladder cancer cells in vitro, providing a potential therapeutic approach to treat bladder cancer. PMID:24815071

  18. Modulation of inflammation and autophagy pathways by trehalose containing eye drop formulation in corneal epithelial cells: implications for dry eye disease

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    Trailokyanath Panigrahi

    2017-10-01

    Full Text Available Ocular surface inflammation is an immunological perturbation activated in response to various adverse conditions and is a key biomarker to understand the disease pathology and its underlying immunological landscape [1]. The molecular link between Inflammation and autophagy, often implicated in disease conditions, is poorly understood. The aim of this study is to understand the regulation of inflammation signaling pathways by using a well-established modulator of autophagy, trehalose (TRE, on desiccation stress-induced inflammation in SV40 immortalized human corneal epithelial cells. To mimic the dry eye condition, HCE cells were exposed to desiccation stress at 80% confluency in a six well tissue culture plate. The medium was completely aspirated and cells were kept for drying at room temperature for 10 min. Fresh medium with TRE was added and incubated for 6 hrs. The regulation of induced inflammatory and autophagic gene expression and protein activation by TRE formulation (1.2% was studied. Optimal drug treatment concentrations were determined by dose escalation cytotoxicity studies. Gene expression was evaluated by quantitative PCR, while protein expression and functions were tested by immunoblotting and fluorescence imaging (Cyto-ID, Lysotracker Red. TRE formulation was able to rescue the morphological changes due to desiccation stress. Live to dead cell ratio increased upon TRE treatment. TRE treatment reduced inflammation induced gene expression of IL-6 (2%, MCP-1 (33.31%, IL-8 (9.56%, MMP-9 (18.96%, and TNFα (58.16% in HCE. Active form of p38, p44/42, and p65 protein levels were altered significantly by TRE treatment. LAMP1 and LC3 autophagy protein markers were also altered with desiccation stress and TRE treatment. The data demonstrate that TRE formulation is effective in reducing desiccation stress induced inflammation in HCE. Further increased phosphorylation of p38, p44/42 and elevated levels of LC3 and LAMP1 suggest that induction

  19. Chaperone-mediated autophagy and neurodegeneration: connections, mechanisms, and therapeutic implications.

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    Liu, Xiaolei; Huang, Sihua; Wang, Xingqin; Tang, Beisha; Li, Wenming; Mao, Zixu

    2015-08-01

    Lysosomes degrade dysfunctional intracellular components via three pathways: macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA). Unlike the other two, CMA degrades cytosolic proteins with a recognized KFERQ-like motif in lysosomes and is important for cellular homeostasis. CMA activity declines with age and is altered in neurodegenerative diseases. Its impairment leads to the accumulation of aggregated proteins, some of which may be directly tied to the pathogenic processes of neurodegenerative diseases. Its induction may accelerate the clearance of pathogenic proteins and promote cell survival, representing a potential therapeutic approach for the treatment of neurodegenerative diseases. In this review, we summarize the current findings on how CMA is involved in neurodegenerative diseases, especially in Parkinson's disease.

  20. The potential regulatory roles of NAD(+) and its metabolism in autophagy.

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    Zhang, Dong-Xia; Zhang, Jia-Ping; Hu, Jiong-Yu; Huang, Yue-Sheng

    2016-04-01

    (Macro)autophagy mediates the bulk degradation of defective organelles, long-lived proteins and protein aggregates in lysosomes and plays a critical role in cellular and tissue homeostasis. Defective autophagy processes have been found to contribute to a variety of metabolic diseases. However, the regulatory mechanisms of autophagy are not fully understood. Increasing data indicate that nicotinamide adenine nucleotide (NAD(+)) homeostasis correlates intimately with autophagy. NAD(+) is a ubiquitous coenzyme that functions primarily as an electron carrier of oxidoreductase in multiple redox reactions. Both NAD(+) homeostasis and its metabolism are thought to play critical roles in regulating autophagy. In this review, we discuss how the regulation of NAD(+) and its metabolism can influence autophagy. We focus on the regulation of NAD(+)/NADH homeostasis and the effects of NAD(+) consumption by poly(ADP-ribose) (PAR) polymerase-1 (PARP-1), NAD(+)-dependent deacetylation by sirtuins and NAD(+) metabolites on autophagy processes and the underlying mechanisms. Future studies should provide more direct evidence for the regulation of autophagy processes by NAD(+). A better understanding of the critical roles of NAD(+) and its metabolites on autophagy will shed light on the complexity of autophagy regulation, which is essential for the discovery of new therapeutic tools for autophagy-related diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Autophagy and Alzheimer’s Disease: From Molecular Mechanisms to Therapeutic Implications

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    Md. Sahab Uddin

    2018-01-01

    Full Text Available Alzheimer’s disease (AD is the most common cause of progressive dementia in the elderly. It is characterized by a progressive and irreversible loss of cognitive abilities and formation of senile plaques, composed mainly of amyloid β (Aβ, and neurofibrillary tangles (NFTs, composed of tau protein, in the hippocampus and cortex of afflicted humans. In brains of AD patients the metabolism of Aβ is dysregulated, which leads to the accumulation and aggregation of Aβ. Metabolism of Aβ and tau proteins is crucially influenced by autophagy. Autophagy is a lysosome-dependent, homeostatic process, in which organelles and proteins are degraded and recycled into energy. Thus, dysfunction of autophagy is suggested to lead to the accretion of noxious proteins in the AD brain. In the present review, we describe the process of autophagy and its importance in AD. Additionally, we discuss mechanisms and genes linking autophagy and AD, i.e., the mTOR pathway, neuroinflammation, endocannabinoid system, ATG7, BCL2, BECN1, CDK5, CLU, CTSD, FOXO1, GFAP, ITPR1, MAPT, PSEN1, SNCA, UBQLN1, and UCHL1. We also present pharmacological agents acting via modulation of autophagy that may show promise in AD therapy. This review updates our knowledge on autophagy mechanisms proposing novel therapeutic targets for the treatment of AD.

  2. Sodium Butyrate Induces Endoplasmic Reticulum Stress and Autophagy in Colorectal Cells: Implications for Apoptosis.

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    Jintao Zhang

    Full Text Available Butyrate, a short-chain fatty acid derived from dietary fiber, inhibits proliferation and induces cell death in colorectal cancer cells. However, clinical trials have shown mixed results regarding the anti-tumor activities of butyrate. We have previously shown that sodium butyrate increases endoplasmic reticulum stress by altering intracellular calcium levels, a well-known autophagy trigger. Here, we investigated whether sodium butyrate-induced endoplasmic reticulum stress mediated autophagy, and whether there was crosstalk between autophagy and the sodium butyrate-induced apoptotic response in human colorectal cancer cells.Human colorectal cancer cell lines (HCT-116 and HT-29 were treated with sodium butyrate at concentrations ranging from 0.5-5mM. Cell proliferation was assessed using MTT tetrazolium salt formation. Autophagy induction was confirmed through a combination of Western blotting for associated proteins, acridine orange staining for acidic vesicles, detection of autolysosomes (MDC staining, and electron microscopy. Apoptosis was quantified by flow cytometry using standard annexinV/propidium iodide staining and by assessing PARP-1 cleavage by Western blot.Sodium butyrate suppressed colorectal cancer cell proliferation, induced autophagy, and resulted in apoptotic cell death. The induction of autophagy was supported by the accumulation of acidic vesicular organelles and autolysosomes, and the expression of autophagy-associated proteins, including microtubule-associated protein II light chain 3 (LC3-II, beclin-1, and autophagocytosis-associated protein (Atg3. The autophagy inhibitors 3-methyladenine (3-MA and chloroquine inhibited sodium butyrate induced autophagy. Furthermore, sodium butyrate treatment markedly enhanced the expression of endoplasmic reticulum stress-associated proteins, including BIP, CHOP, PDI, and IRE-1a. When endoplasmic reticulum stress was inhibited by pharmacological (cycloheximide and mithramycin and genetic

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

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    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.

  4. Epigallocatechin-gallate (EGCG) regulates autophagy in human retinal pigment epithelial cells: A potential role for reducing UVB light-induced retinal damage

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    Li, Chao-Peng; Yao, Jin; Tao, Zhi-Fu; Li, Xiu-Miao; Jiang, Qin; Yan, Biao

    2013-01-01

    Highlights: •UVB irradiation induces RPE autophagy. •EGCG treatment represses UVB-mediated autophagy. •EGCG regulates UVB-mediated autophagy through mTOR signaling pathway. •EGCG sensitizes RPE cells to UVB-induced damage in an autophagy-dependent manner. -- Abstract: Autophagy is an intracellular catabolic process involved in protein and organelle degradation via the lysosomal pathway that has been linked in the pathogenesis of age-related macular degeneration (AMD). UVB irradiation-mediated degeneration of the macular retinal pigment epithelial (RPE) cells is an important hallmark of AMD, which is along with the change in RPE autophagy. Thus, pharmacological manipulation of RPE autophagy may offer an alternative therapeutic target in AMD. Here, we found that epigallocatechin-3-gallate (EGCG), a polyphenolic compound from green tea, plays a regulatory role in UVB irradiation-induced autophagy in RPE cells. UVB irradiation results in a marked increase in the amount of LC3-II protein in a dose-dependent manner. EGCG administration leads to a significant reduction in the formation of LC3-II and autophagosomes. mTOR signaling activation is required for EGCG-induced LC3-II formation, as evidenced by the fact that EGCG-induced LC3-II formation is significantly impaired by rapamycin administration. Moreover, EGCG significantly alleviates the toxic effects of UVB irradiation on RPE cells in an autophagy-dependent manner. Collectively, our study reveals a novel role of EGCG in RPE autophagy. EGCG may be exploited as a potential therapeutic reagent for the treatment of pathological conditions associated with abnormal autophagy

  5. Epigallocatechin-gallate (EGCG) regulates autophagy in human retinal pigment epithelial cells: A potential role for reducing UVB light-induced retinal damage

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chao-Peng; Yao, Jin; Tao, Zhi-Fu; Li, Xiu-Miao; Jiang, Qin, E-mail: jqin710@vip.sina.com; Yan, Biao, E-mail: yanbiao1982@hotmail.com

    2013-09-06

    Highlights: •UVB irradiation induces RPE autophagy. •EGCG treatment represses UVB-mediated autophagy. •EGCG regulates UVB-mediated autophagy through mTOR signaling pathway. •EGCG sensitizes RPE cells to UVB-induced damage in an autophagy-dependent manner. -- Abstract: Autophagy is an intracellular catabolic process involved in protein and organelle degradation via the lysosomal pathway that has been linked in the pathogenesis of age-related macular degeneration (AMD). UVB irradiation-mediated degeneration of the macular retinal pigment epithelial (RPE) cells is an important hallmark of AMD, which is along with the change in RPE autophagy. Thus, pharmacological manipulation of RPE autophagy may offer an alternative therapeutic target in AMD. Here, we found that epigallocatechin-3-gallate (EGCG), a polyphenolic compound from green tea, plays a regulatory role in UVB irradiation-induced autophagy in RPE cells. UVB irradiation results in a marked increase in the amount of LC3-II protein in a dose-dependent manner. EGCG administration leads to a significant reduction in the formation of LC3-II and autophagosomes. mTOR signaling activation is required for EGCG-induced LC3-II formation, as evidenced by the fact that EGCG-induced LC3-II formation is significantly impaired by rapamycin administration. Moreover, EGCG significantly alleviates the toxic effects of UVB irradiation on RPE cells in an autophagy-dependent manner. Collectively, our study reveals a novel role of EGCG in RPE autophagy. EGCG may be exploited as a potential therapeutic reagent for the treatment of pathological conditions associated with abnormal autophagy.

  6. Autophagy regulates the therapeutic potential of mesenchymal stem cells in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Dang, Shipeng; Xu, Huanbai; Xu, Congfeng; Cai, Wei; Li, Qian; Cheng, Yiji; Jin, Min; Wang, Ru-Xing; Peng, Yongde; Zhang, Yi; Wu, Changping; He, Xiaozhou; Wan, Bing; Zhang, Yanyun

    2014-07-01

    Mesenchymal stem cell (MSC)-based therapy is a promising approach to treat various inflammatory disorders including multiple sclerosis. However, the fate of MSCs in the inflammatory microenvironment is largely unknown. Experimental autoimmune encephalomyelitis (EAE) is a well-studied animal model of multiple sclerosis. We demonstrated that autophagy occurred in MSCs during their application for EAE treatment. Inflammatory cytokines, e.g., interferon gamma and tumor necrosis factor, induced autophagy in MSCs synergistically by inducing expression of BECN1/Beclin 1. Inhibition of autophagy by knockdown of Becn1 significantly improved the therapeutic effects of MSCs on EAE, which was mainly attributable to enhanced suppression upon activation and expansion of CD4(+) T cells. Mechanistically, inhibition of autophagy increased reactive oxygen species generation and mitogen-activated protein kinase 1/3 activation in MSCs, which were essential for PTGS2 (prostaglandin-endoperoxide synthase 2 [prostaglandin G/H synthase and cyclooxygenase]) and downstream prostaglandin E2 expression to exert immunoregulatory function. Furthermore, pharmacological treatment of MSCs to inhibit autophagy increased their immunosuppressive effects on T cell-mediated EAE. Our findings indicate that inflammatory microenvironment-induced autophagy downregulates the immunosuppressive function of MSCs. Therefore, modulation of autophagy in MSCs would provide a novel strategy to improve MSC-based immunotherapy.

  7. Autophagy Is a Protective Response to the Oxidative Damage to Endplate Chondrocytes in Intervertebral Disc: Implications for the Treatment of Degenerative Lumbar Disc

    Directory of Open Access Journals (Sweden)

    Ke Chen

    2017-01-01

    Full Text Available Low back pain (LBP is the leading cause of disability in the elderly. Intervertebral disc degeneration (IDD was considered as the main cause for LBP. Degeneration of cartilaginous endplate was a crucial harmful factor during the initiation and development of IDD. Oxidative stress was implicated in IDD. However, the underlying molecular mechanism for the degeneration of cartilaginous endplate remains elusive. Herein, we found that oxidative stress could induce apoptosis and autophagy in endplate chondrocytes evidenced by western blot analysis, flow cytometry, immunofluorescence staining, GFP-LC3B transfection, and MDC staining. In addition, we also found that the apoptosis of endplate chondrocytes was significantly increased after the inhibition of autophagy by bafilomycin A1 shown by flow cytometry. Furthermore, mTOR pathway upstream autophagy was greatly suppressed suggested by western blot assay. In conclusion, our study strongly revealed that oxidative stress could increase autophagy and apoptosis of endplate chondrocytes in intervertebral disc. The increase of autophagy activity could prevent endplate chondrocytes from apoptosis. The autophagy in endplate chondrocytes induced by oxidative stress was mTOR dependent. These findings might shed some new lights on the mechanism for IDD and provide new strategies for the treatments of IDD.

  8. Enhanced myometrial autophagy in postpartum uterine involution

    Directory of Open Access Journals (Sweden)

    Keng-Fu Hsu

    2014-09-01

    Conclusion: Autophagy of myocytes may play an important role in uterine involution. These results have implications for our understanding of myometrial functional adaptations during pregnancy and the physiological role of autophagy in the uterine remodeling events in the postpartum period.

  9. MicroRNA regulation of Autophagy

    DEFF Research Database (Denmark)

    Frankel, Lisa B; Lund, Anders H

    2012-01-01

    recently contributed to our understanding of the molecular mechanisms of the autophagy machinery, yet several gaps remain in our knowledge of this process. The discovery of microRNAs (miRNAs) established a new paradigm of post-transcriptional gene regulation and during the past decade these small non......RNAs to regulation of the autophagy pathway. This regulation occurs both through specific core pathway components as well as through less well-defined mechanisms. Although this field is still in its infancy, we are beginning to understand the potential implications of these initial findings, both from a pathological...

  10. Natural Compounds from Herbs that can Potentially Execute as Autophagy Inducers for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Shian-Ren Lin

    2017-07-01

    Full Text Available Accumulated evidence indicates that autophagy is a response of cancer cells to various anti-cancer therapies. Autophagy is designated as programmed cell death type II, and is characterized by the formation of autophagic vacuoles in the cytoplasm. Numerous herbs, including Chinese herbs, have been applied to cancer treatments as complementary and alternative medicines, supplements, or nutraceuticals to dampen the side or adverse effects of chemotherapy drugs. Moreover, the tumor suppressive actions of herbs and natural products induced autophagy that may lead to cell senescence, increase apoptosis-independent cell death or complement apoptotic processes. Hereby, the underlying mechanisms of natural autophagy inducers are cautiously reviewed in this article. Additionally, three natural compounds—curcumin, 16-hydroxycleroda-3,13-dien-15,16-olide, and prodigiosin—are presented as candidates for autophagy inducers that can trigger cell death in a supplement or alternative medicine for cancer therapy. Despite recent advancements in therapeutic drugs or agents of natural products in several cancers, it warrants further investigation in preclinical and clinical studies.

  11. BAG3 induces the sequestration of proteasomal clients into cytoplasmic puncta : Implications for a proteasome-to-autophagy switch

    NARCIS (Netherlands)

    Minoia, Melania; Boncoraglio, Alessandra; Vinet, Jonathan; Morelli, Federica F.; Brunsting, Jeanette F.; Poletti, Angelo; Krom, Sabine; Reits, Eric; Kampinga, Harm H.; Carra, Serena

    Eukaryotic cells use autophagy and the ubiquitin-proteasome system as their major protein degradation pathways. Upon proteasomal impairment, cells switch to autophagy to ensure proper clearance of clients (the proteasome-to-autophagy switch). The HSPA8 and HSPA1A cochaperone BAG3 has been suggested

  12. BAG3 induces the sequestration of proteasomal clients into cytoplasmic puncta: implications for a proteasome-to-autophagy switch

    NARCIS (Netherlands)

    Minoia, Melania; Boncoraglio, Alessandra; Vinet, Jonathan; Morelli, Federica F.; Brunsting, Jeanette F.; Poletti, Angelo; Krom, Sabine; Reits, Eric; Kampinga, Harm H.; Carra, Serena

    2014-01-01

    Eukaryotic cells use autophagy and the ubiquitin-proteasome system as their major protein degradation pathways. Upon proteasomal impairment, cells switch to autophagy to ensure proper clearance of clients (the proteasome-to-autophagy switch). The HSPA8 and HSPA1A cochaperone BAG3 has been suggested

  13. Concanavalin A: A potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis for cancer therapeutics

    International Nuclear Information System (INIS)

    Li, Wen-wen; Yu, Jia-ying; Xu, Huai-long; Bao, Jin-ku

    2011-01-01

    Highlights: → ConA induces cancer cell death targeting apoptosis and autophagy. → ConA inhibits cancer cell angiogenesis. → ConA is utilized in pre-clinical and clinical trials. -- Abstract: Concanavalin A (ConA), a Ca 2+ /Mn 2+ -dependent and mannose/glucose-binding legume lectin, has drawn a rising attention for its remarkable anti-proliferative and anti-tumor activities to a variety of cancer cells. ConA induces programmed cell death via mitochondria-mediated, P73-Foxo1a-Bim apoptosis and BNIP3-mediated mitochondrial autophagy. Through IKK-NF-κB-COX-2, SHP-2-MEK-1-ERK, and SHP-2-Ras-ERK anti-angiogenic pathways, ConA would inhibit cancer cell survival. In addition, ConA stimulates cell immunity and generates an immune memory, resisting to the same genotypic tumor. These biological findings shed light on new perspectives of ConA as a potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis in pre-clinical or clinical trials for cancer therapeutics.

  14. Circulating Autoantibodies in Age-Related Macular Degeneration Recognize Human Macular Tissue Antigens Implicated in Autophagy, Immunomodulation, and Protection from Oxidative Stress and Apoptosis.

    Directory of Open Access Journals (Sweden)

    Alessandro Iannaccone

    immune system in AMD pathogenesis, AAbs were identified in AMD sera, including early-stage disease. Identified targets may be mechanistically linked to AMD pathogenesis because the identified proteins are implicated in autophagy, immunomodulation, and protection from oxidative stress and apoptosis. In particular, a role in autophagy activation is shared by all five autoantigens, raising the possibility that the detected AAbs may play a role in AMD via autophagy compromise and downstream activation of the inflammasome. Thus, we propose that the detected AAbs provide further insight into AMD pathogenesis and have the potential to contribute to disease biogenesis and progression.

  15. Dengue Virus and Autophagy

    Directory of Open Access Journals (Sweden)

    Nicholas S. Heaton

    2011-08-01

    Full Text Available Several independent groups have published that autophagy is required for optimal RNA replication of dengue virus (DENV. Initially, it was postulated that autophagosomes might play a structural role in replication complex formation. However, cryo-EM tomography of DENV replication complexes showed that DENV replicates on endoplasmic reticulum (ER cisternae invaginations and not on classical autophagosomes. Recently, it was reported that autophagy plays an indirect role in DENV replication by modulating cellular lipid metabolism. DENV-induced autophagosomes deplete cellular triglycerides that are stored in lipid droplets, leading to increased β-oxidation and energy production. This is the first example of a virus triggering autophagy to modulate cellular physiology. In this review, we summarize these data and discuss new questions and implications for autophagy during DENV replication.

  16. Impaired Autophagy in the Lipid-Storage Disorder Niemann-Pick Type C1 Disease

    Directory of Open Access Journals (Sweden)

    Sovan Sarkar

    2013-12-01

    Full Text Available Autophagy dysfunction has been implicated in misfolded protein accumulation and cellular toxicity in several diseases. Whether alterations in autophagy also contribute to the pathology of lipid-storage disorders is not clear. Here, we show defective autophagy in Niemann-Pick type C1 (NPC1 disease associated with cholesterol accumulation, where the maturation of autophagosomes is impaired because of defective amphisome formation caused by failure in SNARE machinery, whereas the lysosomal proteolytic function remains unaffected. Expression of functional NPC1 protein rescues this defect. Inhibition of autophagy also causes cholesterol accumulation. Compromised autophagy was seen in disease-affected organs of Npc1 mutant mice. Of potential therapeutic relevance is that HP-β-cyclodextrin, which is used for cholesterol-depletion treatment, impedes autophagy, whereas stimulating autophagy restores its function independent of amphisome formation. Our data suggest that a low dose of HP-β-cyclodextrin that does not perturb autophagy, coupled with an autophagy inducer, may provide a rational treatment strategy for NPC1 disease.

  17. Impaired autophagy in the lipid-storage disorder Niemann-Pick type C1 disease.

    Science.gov (United States)

    Sarkar, Sovan; Carroll, Bernadette; Buganim, Yosef; Maetzel, Dorothea; Ng, Alex H M; Cassady, John P; Cohen, Malkiel A; Chakraborty, Souvik; Wang, Haoyi; Spooner, Eric; Ploegh, Hidde; Gsponer, Joerg; Korolchuk, Viktor I; Jaenisch, Rudolf

    2013-12-12

    Autophagy dysfunction has been implicated in misfolded protein accumulation and cellular toxicity in several diseases. Whether alterations in autophagy also contribute to the pathology of lipid-storage disorders is not clear. Here, we show defective autophagy in Niemann-Pick type C1 (NPC1) disease associated with cholesterol accumulation, where the maturation of autophagosomes is impaired because of defective amphisome formation caused by failure in SNARE machinery, whereas the lysosomal proteolytic function remains unaffected. Expression of functional NPC1 protein rescues this defect. Inhibition of autophagy also causes cholesterol accumulation. Compromised autophagy was seen in disease-affected organs of Npc1 mutant mice. Of potential therapeutic relevance is that HP-β-cyclodextrin, which is used for cholesterol-depletion treatment, impedes autophagy, whereas stimulating autophagy restores its function independent of amphisome formation. Our data suggest that a low dose of HP-β-cyclodextrin that does not perturb autophagy, coupled with an autophagy inducer, may provide a rational treatment strategy for NPC1 disease. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  18. BAG3 promoted starvation-induced apoptosis of thyroid cancer cells via attenuation of autophagy.

    Science.gov (United States)

    Li, Si; Zhang, Hai-Yan; Wang, Tian; Meng, Xin; Zong, Zhi-Hong; Kong, De-Hui; Wang, Hua-Qin; Du, Zhen-Xian

    2014-11-01

    BAG3 plays a regulatory role in a number of cellular processes. Recent studies have attracted much attention on its role in activation of selective autophagy. In addition, we have very recently reported that BAG3 is implicated in a BECN1-independent autophagy, namely noncanonical autophagy. The current study aimed to investigate the potential involvement of BAG3 in canonical autophagy triggered by Earle's Balanced Salt Solution (EBSS) starvation. Replacement of complete medium with EBSS was used to trigger canonical autophagy. BAG3 expression was measured using real-time RT-PCR and Western blot. Autophagy was monitored using LC3-II transition and p62/SQSTM1 accumulation by Western blot, as well as punctate distribution of LC3 by immunofluorescence staining. Cell growth and apoptotic cell death was investigated using real-time cell analyzer and flowcytometry, respectively. BAG3 expression was potently reduced by EBSS starvation. Forced expression of BAG3 suppressed autophagy and promoted apoptotic cell death of thyroid cancer cells elicited by starvation. In addition, in the presence of autophagy inhibitor, the enhancing effect of BAG3 on apoptotic cell death was attenuated. These results suggest that BAG3 promotes apoptotic cell death in starved thyroid cancer cells, at least in part by autophagy attenuation.

  19. Molecular characterization and expression of Rab7 from Clonorchis sinensis and its potential role in autophagy.

    Science.gov (United States)

    Jia, Feifei; Li, Ye; Huang, Yan; Chen, Tingjin; Li, Shan; Xu, Yanquan; Wu, Zhongdao; Li, Xuerong; Yu, Xinbing

    2013-07-01

    Accumulating evidences suggest that Rab7 GTPase is important for the normal progression of autophagy. However, the role of Rab7 GTPase in regulation of autophagy in Clonorchis sinensis is not known. In this study, a gene encoding Rab7 was isolated from C. sinensis adult cDNA. Recombinant CsRab7 was expressed and purified from Escherichia coli. CsRab7 transcripts were detected in the cDNA of adult worm, metacercaria, cercaria, and egg of C. sinensis, and were highly expressed in the metacercaria. Immunohistochemical localization results revealed that CsRab7 was specifically deposited on the vitellarium and eggs of adult worm. Furthermore, EGFP signal of CsRab7WT and the active mutant CsRab7Q67L were associated with autophagic vesicles in transiently transfected 293T cells. It is concluded from the present study that CsRab7 GTPase possibly contributes to the development of C. sinensis and that the autophagy pathway could be an important site of action with respect to the developmental role of CsRab7 in C. sinensis.

  20. Retinoid receptor signaling and autophagy in acute promyelocytic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Orfali, Nina [Cork Cancer Research Center, University College Cork, Cork (Ireland); Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA. (United States); McKenna, Sharon L. [Cork Cancer Research Center, University College Cork, Cork (Ireland); Cahill, Mary R. [Department of Hematology, Cork University Hospital, Cork (Ireland); Gudas, Lorraine J., E-mail: ljgudas@med.cornell.edu [Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA. (United States); Mongan, Nigel P., E-mail: nigel.mongan@nottingham.ac.uk [Faculty of Medicine and Health Science, School of Veterinary Medicine and Science, University of Nottingham, LE12 5RD (United Kingdom); Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA. (United States)

    2014-05-15

    Retinoids are a family of signaling molecules derived from vitamin A with well established roles in cellular differentiation. Physiologically active retinoids mediate transcriptional effects on cells through interactions with retinoic acid (RARs) and retinoid-X (RXR) receptors. Chromosomal translocations involving the RARα gene, which lead to impaired retinoid signaling, are implicated in acute promyelocytic leukemia (APL). All-trans-retinoic acid (ATRA), alone and in combination with arsenic trioxide (ATO), restores differentiation in APL cells and promotes degradation of the abnormal oncogenic fusion protein through several proteolytic mechanisms. RARα fusion-protein elimination is emerging as critical to obtaining sustained remission and long-term cure in APL. Autophagy is a degradative cellular pathway involved in protein turnover. Both ATRA and ATO also induce autophagy in APL cells. Enhancing autophagy may therefore be of therapeutic benefit in resistant APL and could broaden the application of differentiation therapy to other cancers. Here we discuss retinoid signaling in hematopoiesis, leukemogenesis, and APL treatment. We highlight autophagy as a potential important regulator in anti-leukemic strategies. - Highlights: • Normal and aberrant retinoid signaling in hematopoiesis and leukemia is reviewed. • We suggest a novel role for RARα in the development of X-RARα gene fusions in APL. • ATRA therapy in APL activates transcription and promotes onco-protein degradation. • Autophagy may be involved in both onco-protein degradation and differentiation. • Pharmacologic autophagy induction may potentiate ATRA's therapeutic effects.

  1. Retinoid receptor signaling and autophagy in acute promyelocytic leukemia

    International Nuclear Information System (INIS)

    Orfali, Nina; McKenna, Sharon L.; Cahill, Mary R.; Gudas, Lorraine J.; Mongan, Nigel P.

    2014-01-01

    Retinoids are a family of signaling molecules derived from vitamin A with well established roles in cellular differentiation. Physiologically active retinoids mediate transcriptional effects on cells through interactions with retinoic acid (RARs) and retinoid-X (RXR) receptors. Chromosomal translocations involving the RARα gene, which lead to impaired retinoid signaling, are implicated in acute promyelocytic leukemia (APL). All-trans-retinoic acid (ATRA), alone and in combination with arsenic trioxide (ATO), restores differentiation in APL cells and promotes degradation of the abnormal oncogenic fusion protein through several proteolytic mechanisms. RARα fusion-protein elimination is emerging as critical to obtaining sustained remission and long-term cure in APL. Autophagy is a degradative cellular pathway involved in protein turnover. Both ATRA and ATO also induce autophagy in APL cells. Enhancing autophagy may therefore be of therapeutic benefit in resistant APL and could broaden the application of differentiation therapy to other cancers. Here we discuss retinoid signaling in hematopoiesis, leukemogenesis, and APL treatment. We highlight autophagy as a potential important regulator in anti-leukemic strategies. - Highlights: • Normal and aberrant retinoid signaling in hematopoiesis and leukemia is reviewed. • We suggest a novel role for RARα in the development of X-RARα gene fusions in APL. • ATRA therapy in APL activates transcription and promotes onco-protein degradation. • Autophagy may be involved in both onco-protein degradation and differentiation. • Pharmacologic autophagy induction may potentiate ATRA's therapeutic effects

  2. Autophagy in Measles Virus Infection

    Directory of Open Access Journals (Sweden)

    Aurore Rozières

    2017-11-01

    Full Text Available Autophagy is a biological process that helps cells to recycle obsolete cellular components and which greatly contributes to maintaining cellular integrity in response to environmental stress factors. Autophagy is also among the first lines of cellular defense against invading microorganisms, including viruses. The autophagic destruction of invading pathogens, a process referred to as xenophagy, involves cytosolic autophagy receptors, such as p62/SQSTM1 (Sequestosome 1 or NDP52/CALCOCO2 (Nuclear Dot 52 KDa Protein/Calcium Binding And Coiled-Coil Domain 2, which bind to microbial components and target them towards growing autophagosomes for degradation. However, most, if not all, infectious viruses have evolved molecular tricks to escape from xenophagy. Many viruses even use autophagy, part of the autophagy pathway or some autophagy-associated proteins, to improve their infectious potential. In this regard, the measles virus, responsible for epidemic measles, has a unique interface with autophagy as the virus can induce multiple rounds of autophagy in the course of infection. These successive waves of autophagy result from distinct molecular pathways and seem associated with anti- and/or pro-measles virus consequences. In this review, we describe what the autophagy–measles virus interplay has taught us about both the biology of the virus and the mechanistic orchestration of autophagy.

  3. Nuclear energy: potentiality and implications

    International Nuclear Information System (INIS)

    Bahgat, Gawdat

    2008-01-01

    After a discussion about a broad definition of energy security and about the main challenges facing a potential nuclear renaissance, the article analyses how the European Union and the United States have addressed these challenges. There is no doubt that nuclear power will remain an important component of global energy mix, but it should not be seen as a panacea to the flows in the global energy markets [it

  4. Diet-induced obesity impairs endometrial stromal cell decidualization: a potential role for impaired autophagy.

    Science.gov (United States)

    Rhee, Julie S; Saben, Jessica L; Mayer, Allyson L; Schulte, Maureen B; Asghar, Zeenat; Stephens, Claire; Chi, Maggie M-Y; Moley, Kelle H

    2016-06-01

    What effect does diet-induced obesity have on endometrial stromal cell (ESC) decidualization? Diet-induced obesity impairs ESC decidualization. Decidualization is important for successful implantation and subsequent health of the pregnancy. Compared with normal-weight women, obese women have lower pregnancy rates (both spontaneous and by assisted reproductive technology), higher rates of early pregnancy loss and poorer oocyte quality. Beginning at 6 weeks of age, female C57Bl/6J mice were fed either a high-fat/high-sugar diet (HF/HS; 58% Fat Energy/Sucrose) or a diet of standard mouse chow (CON; 13% Fat) for 12 weeks. At this point, metabolic parameters were measured. Some of the mice (n = 9 HF/HS and 9 CON) were mated with reproductively competent males, and implantation sites were assessed. Other mice (n = 11 HF/HS and 10 CON) were mated with vasectomized males, and artificial decidualization was induced. For in vitro human studies of primary ESCs, endometrial tissue was obtained via biopsy from normo-ovulatory patients without history of infertility (obese = BMI > 30 kg/m(2), n = 11 and lean = BMI treatment with cAMP and medroxyprogesterone. The level of expression of decidualization markers was assessed by RT-qPCR (mRNA) and western blotting (protein). ATP content of ESCs was measured, and levels of autophagy were assessed by western blotting of the autophagy regulators acetyl coa carboxylase (ACC) and ULK1 (Ser 317). Autophagic flux was measured by western blot of the marker LC3b-II. Mice exposed to an HF/HS diet became obese and metabolically impaired. HF/HS-exposed mice mated to reproductively competent males had smaller implantation sites in early pregnancy (P obese women than in those of normal-weight women (Ptreatment abrogated this increase. Many aspects of obesity and metabolic impairment could contribute to the decidualization defects observed in the HF/HS-exposed mice. Although our findings suggest that both autophagy and decidualization are impaired

  5. Inducing autophagy

    DEFF Research Database (Denmark)

    Harder, Lea M; Bunkenborg, Jakob; Andersen, Jens S.

    2014-01-01

    catabolism, which has recently been found to induce autophagy in an MTOR independent way and support cancer cell survival. In this study, quantitative phosphoproteomics was applied to investigate the initial signaling events linking ammonia to the induction of autophagy. The MTOR inhibitor rapamycin was used...... as a reference treatment to emphasize the differences between an MTOR-dependent and -independent autophagy-induction. By this means 5901 phosphosites were identified of which 626 were treatment-specific regulated and 175 were coregulated. Investigation of the ammonia-specific regulated sites supported that MTOR...

  6. BAG3 induces the sequestration of proteasomal clients into cytoplasmic puncta: implications for a proteasome-to-autophagy switch.

    Science.gov (United States)

    Minoia, Melania; Boncoraglio, Alessandra; Vinet, Jonathan; Morelli, Federica F; Brunsting, Jeanette F; Poletti, Angelo; Krom, Sabine; Reits, Eric; Kampinga, Harm H; Carra, Serena

    2014-09-01

    Eukaryotic cells use autophagy and the ubiquitin-proteasome system as their major protein degradation pathways. Upon proteasomal impairment, cells switch to autophagy to ensure proper clearance of clients (the proteasome-to-autophagy switch). The HSPA8 and HSPA1A cochaperone BAG3 has been suggested to be involved in this switch. However, at present it is still unknown whether and to what extent BAG3 can indeed reroute proteasomal clients to the autophagosomal pathway. Here, we show that BAG3 induces the sequestration of ubiquitinated clients into cytoplasmic puncta colabeled with canonical autophagy linkers and markers. Following proteasome inhibition, BAG3 upregulation significantly contributes to the compensatory activation of autophagy and to the degradation of the (poly)ubiquitinated proteins. BAG3 binding to the ubiquitinated clients occurs through the BAG domain, in competition with BAG1, another BAG family member, that normally directs ubiquitinated clients to the proteasome. Therefore, we propose that following proteasome impairment, increasing the BAG3/BAG1 ratio ensures the "BAG-instructed proteasomal to autophagosomal switch and sorting" (BIPASS).

  7. Targeting autophagy in obesity: from pathophysiology to management.

    Science.gov (United States)

    Zhang, Yingmei; Sowers, James R; Ren, Jun

    2018-04-23

    Obesity poses a severe threat to human health, including the increased prevalence of hypertension, insulin resistance, diabetes mellitus, cancer, inflammation, sleep apnoea and other chronic diseases. Current therapies focus mainly on suppressing caloric intake, but the efficacy of this approach remains poor. A better understanding of the pathophysiology of obesity will be essential for the management of obesity and its complications. Knowledge gained over the past three decades regarding the aetiological mechanisms underpinning obesity has provided a framework that emphasizes energy imbalance and neurohormonal dysregulation, which are tightly regulated by autophagy. Accordingly, there is an emerging interest in the role of autophagy, a conserved homeostatic process for cellular quality control through the disposal and recycling of cellular components, in the maintenance of cellular homeostasis and organ function by selectively ridding cells of potentially toxic proteins, lipids and organelles. Indeed, defects in autophagy homeostasis are implicated in metabolic disorders, including obesity, insulin resistance, diabetes mellitus and atherosclerosis. In this Review, the alterations in autophagy that occur in response to nutrient stress, and how these changes alter the course of obesogenesis and obesity-related complications, are discussed. The potential of pharmacological modulation of autophagy for the management of obesity is also addressed.

  8. Autophagy: a new player in skeletal maintenance?

    Science.gov (United States)

    Hocking, Lynne J; Whitehouse, Caroline; Helfrich, Miep H

    2012-07-01

    Imbalances between bone resorption and formation lie at the root of disorders such as osteoporosis, Paget's disease of bone (PDB), and osteopetrosis. Recently, genetic and functional studies have implicated proteins involved in autophagic protein degradation as important mediators of bone cell function in normal physiology and in pathology. Autophagy is the conserved process whereby aggregated proteins, intracellular pathogens, and damaged organelles are degraded and recycled. This process is important both for normal cellular quality control and in response to environmental or internal stressors, particularly in terminally-differentiated cells. Autophagic structures can also act as hubs for the spatial organization of recycling and synthetic process in secretory cells. Alterations to autophagy (reduction, hyperactivation, or impairment) are associated with a number of disorders, including neurodegenerative diseases and cancers, and are now being implicated in maintenance of skeletal homoeostasis. Here, we introduce the topic of autophagy, describe the new findings that are starting to emerge from the bone field, and consider the therapeutic potential of modifying this pathway for the treatment of age-related bone disorders. Copyright © 2012 American Society for Bone and Mineral Research.

  9. Autophagy, lipophagy and lysosomal lipid storage disorders.

    Science.gov (United States)

    Ward, Carl; Martinez-Lopez, Nuria; Otten, Elsje G; Carroll, Bernadette; Maetzel, Dorothea; Singh, Rajat; Sarkar, Sovan; Korolchuk, Viktor I

    2016-04-01

    Autophagy is a catabolic process with an essential function in the maintenance of cellular and tissue homeostasis. It is primarily recognised for its role in the degradation of dysfunctional proteins and unwanted organelles, however in recent years the range of autophagy substrates has also been extended to lipids. Degradation of lipids via autophagy is termed lipophagy. The ability of autophagy to contribute to the maintenance of lipo-homeostasis becomes particularly relevant in the context of genetic lysosomal storage disorders where perturbations of autophagic flux have been suggested to contribute to the disease aetiology. Here we review recent discoveries of the molecular mechanisms mediating lipid turnover by the autophagy pathways. We further focus on the relevance of autophagy, and specifically lipophagy, to the disease mechanisms. Moreover, autophagy is also discussed as a potential therapeutic target in several key lysosomal storage disorders. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Emerging connections between RNA and autophagy

    DEFF Research Database (Denmark)

    Frankel, Lisa B; Lubas, Michal; Lund, Anders H

    2017-01-01

    in yeast, plants and animals, reviewing the molecular mechanisms and biological importance in normal physiology, stress and disease. In addition, we explore emerging evidence of core autophagy regulation mediated by RNA-binding proteins and noncoding RNAs, and point to gaps in our current knowledge......Macroautophagy/autophagy is a key catabolic process, essential for maintaining cellular homeostasis and survival through the removal and recycling of unwanted cellular material. Emerging evidence has revealed intricate connections between the RNA and autophagy research fields. While a majority...... of the connection between RNA and autophagy. Finally, we discuss the pathological implications of RNA-protein aggregation, primarily in the context of neurodegenerative disease....

  11. Autophagy induction by SIRT6 is involved in oxidative stress-induced neuronal damage

    Directory of Open Access Journals (Sweden)

    Jiaxiang Shao

    2016-03-01

    Full Text Available Abstract SIRT6 is a NAD+-dependent histone deacetylase and has been implicated in the regulation of genomic stability, DNA repair, metabolic homeostasis and several diseases. The effect of SIRT6 in cerebral ischemia and oxygen/glucose deprivation (OGD has been reported, however the role of SIRT6 in oxidative stress damage remains unclear. Here we used SH-SY5Y neuronal cells and found that overexpression of SIRT6 led to decreased cell viability and increased necrotic cell death and reactive oxygen species (ROS production under oxidative stress. Mechanistic study revealed that SIRT6 induced autophagy via attenuation of AKT signaling and treatment with autophagy inhibitor 3-MA or knockdown of autophagy-related protein Atg5 rescued H2O2-induced neuronal injury. Conversely, SIRT6 inhibition suppressed autophagy and reduced oxidative stress-induced neuronal damage. These results suggest that SIRT6 might be a potential therapeutic target for neuroprotection.

  12. Mir143-BBC3 cascade reduces microglial survival via interplay between apoptosis and autophagy: Implications for methamphetamine-mediated neurotoxicity

    Science.gov (United States)

    Zhang, Yuan; Shen, Kai; Bai, Ying; Lv, Xuan; Huang, Rongrong; Zhang, Wei; Chao, Jie; Nguyen, Lan K.; Hua, Jun; Gan, Guangming; Hu, Gang; Yao, Honghong

    2016-01-01

    ABSTRACT BBC3 (BCL2 binding component 3) is a known apoptosis inducer; however, its role in microglial survival remains poorly understood. In addition to the classical transcription factor TRP53, Mir143 is involved in BBC3 expression at the post-transcriptional level. Here, we identify unique roles of Mir143-BBC3 in mediating microglial survival via the regulation of the interplay between apoptosis and autophagy. Autophagy inhibition accelerated methamphetamine-induced apoptosis, whereas autophagy induction attenuated the decrease in microglial survival. Moreover, anti-Mir143-dependent BBC3 upregulation reversed the methamphetamine-induced decrease in microglial survival via the regulation of apoptosis and autophagy. The in vivo relevance of these findings was confirmed in mouse models, which demonstrated that the microinjection of anti-Mir143 into the hippocampus ameliorated the methamphetamine-induced decrease in microglia as well as that observed in heterozygous Mir143+/− mice. These findings provide new insight regarding the specific contributions of Mir143-BBC3 to microglial survival in the context of drug abuse. PMID:27464000

  13. Oxidative stress-induced autophagy: Role in pulmonary toxicity

    International Nuclear Information System (INIS)

    Malaviya, Rama; Laskin, Jeffrey D.; Laskin, Debra L.

    2014-01-01

    Autophagy is an evolutionarily conserved catabolic process important in regulating the turnover of essential proteins and in elimination of damaged organelles and protein aggregates. Autophagy is observed in the lung in response to oxidative stress generated as a consequence of exposure to environmental toxicants. Whether autophagy plays role in promoting cell survival or cytotoxicity is unclear. In this article recent findings on oxidative stress-induced autophagy in the lung are reviewed; potential mechanisms initiating autophagy are also discussed. A better understanding of autophagy and its role in pulmonary toxicity may lead to the development of new strategies to treat lung injury associated with oxidative stress. - Highlights: • Exposure to pulmonary toxicants is associated with oxidative stress. • Oxidative stress is known to induce autophagy. • Autophagy is upregulated in the lung following exposure to pulmonary toxicants. • Autophagy may be protective or pathogenic

  14. Oxidative stress-induced autophagy: Role in pulmonary toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Malaviya, Rama [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States); Laskin, Jeffrey D. [Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854 (United States); Laskin, Debra L., E-mail: laskin@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States)

    2014-03-01

    Autophagy is an evolutionarily conserved catabolic process important in regulating the turnover of essential proteins and in elimination of damaged organelles and protein aggregates. Autophagy is observed in the lung in response to oxidative stress generated as a consequence of exposure to environmental toxicants. Whether autophagy plays role in promoting cell survival or cytotoxicity is unclear. In this article recent findings on oxidative stress-induced autophagy in the lung are reviewed; potential mechanisms initiating autophagy are also discussed. A better understanding of autophagy and its role in pulmonary toxicity may lead to the development of new strategies to treat lung injury associated with oxidative stress. - Highlights: • Exposure to pulmonary toxicants is associated with oxidative stress. • Oxidative stress is known to induce autophagy. • Autophagy is upregulated in the lung following exposure to pulmonary toxicants. • Autophagy may be protective or pathogenic.

  15. Dihydroartemisinin potentiates the anticancer effect of cisplatin via mTOR inhibition in cisplatin-resistant ovarian cancer cells: involvement of apoptosis and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xue [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Li, Ling [Department of Brain Cognition Computing Lab, University of Kent, Kent CT2 7NZ (United Kingdom); Jiang, Hong; Jiang, Keping; Jin, Ye [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zheng, Jianhua, E-mail: zhengjianhua1115@126.com [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

    2014-02-14

    Highlights: • Phosphorylation of mTOR is abnormal activation in SKOV3/DDP ovarian cancer cells. • Downregulation of mTOR by DHA helps to sensitize the SKOV3/DDP cells to chemotherapy. • DHA has the potential of induce autophagy in cancer cells. - Abstract: Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistant human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells.

  16. Dihydroartemisinin potentiates the anticancer effect of cisplatin via mTOR inhibition in cisplatin-resistant ovarian cancer cells: involvement of apoptosis and autophagy

    International Nuclear Information System (INIS)

    Feng, Xue; Li, Ling; Jiang, Hong; Jiang, Keping; Jin, Ye; Zheng, Jianhua

    2014-01-01

    Highlights: • Phosphorylation of mTOR is abnormal activation in SKOV3/DDP ovarian cancer cells. • Downregulation of mTOR by DHA helps to sensitize the SKOV3/DDP cells to chemotherapy. • DHA has the potential of induce autophagy in cancer cells. - Abstract: Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistant human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells

  17. EVA1A/TMEM166 Regulates Embryonic Neurogenesis by Autophagy

    Directory of Open Access Journals (Sweden)

    Mengtao Li

    2016-03-01

    Full Text Available Self-renewal and differentiation of neural stem cells is essential for embryonic neurogenesis, which is associated with cell autophagy. However, the mechanism by which autophagy regulates neurogenesis remains undefined. Here, we show that Eva1a/Tmem166, an autophagy-related gene, regulates neural stem cell self-renewal and differentiation. Eva1a depletion impaired the generation of newborn neurons, both in vivo and in vitro. Conversely, overexpression of EVA1A enhanced newborn neuron generation and maturation. Moreover, Eva1a depletion activated the PIK3CA-AKT axis, leading to the activation of the mammalian target of rapamycin and the subsequent inhibition of autophagy. Furthermore, addition of methylpyruvate to the culture during neural stem cell differentiation rescued the defective embryonic neurogenesis induced by Eva1a depletion, suggesting that energy availability is a significant factor in embryonic neurogenesis. Collectively, these data demonstrated that EVA1A regulates embryonic neurogenesis by modulating autophagy. Our results have potential implications for understanding the pathogenesis of neurodevelopmental disorders caused by autophagy dysregulation.

  18. Exploring autophagy with Gene Ontology

    Science.gov (United States)

    2018-01-01

    ABSTRACT Autophagy is a fundamental cellular process that is well conserved among eukaryotes. It is one of the strategies that cells use to catabolize substances in a controlled way. Autophagy is used for recycling cellular components, responding to cellular stresses and ridding cells of foreign material. Perturbations in autophagy have been implicated in a number of pathological conditions such as neurodegeneration, cardiac disease and cancer. The growing knowledge about autophagic mechanisms needs to be collected in a computable and shareable format to allow its use in data representation and interpretation. The Gene Ontology (GO) is a freely available resource that describes how and where gene products function in biological systems. It consists of 3 interrelated structured vocabularies that outline what gene products do at the biochemical level, where they act in a cell and the overall biological objectives to which their actions contribute. It also consists of ‘annotations’ that associate gene products with the terms. Here we describe how we represent autophagy in GO, how we create and define terms relevant to autophagy researchers and how we interrelate those terms to generate a coherent view of the process, therefore allowing an interoperable description of its biological aspects. We also describe how annotation of gene products with GO terms improves data analysis and interpretation, hence bringing a significant benefit to this field of study. PMID:29455577

  19. Retinoid receptor signaling and autophagy in acute promyelocytic leukemia.

    LENUS (Irish Health Repository)

    Orfali, Nina

    2014-05-15

    Retinoids are a family of signaling molecules derived from vitamin A with well established roles in cellular differentiation. Physiologically active retinoids mediate transcriptional effects on cells through interactions with retinoic acid (RARs) and retinoid-X (RXR) receptors. Chromosomal translocations involving the RARα gene, which lead to impaired retinoid signaling, are implicated in acute promyelocytic leukemia (APL). All-trans-retinoic acid (ATRA), alone and in combination with arsenic trioxide (ATO), restores differentiation in APL cells and promotes degradation of the abnormal oncogenic fusion protein through several proteolytic mechanisms. RARα fusion-protein elimination is emerging as critical to obtaining sustained remission and long-term cure in APL. Autophagy is a degradative cellular pathway involved in protein turnover. Both ATRA and ATO also induce autophagy in APL cells. Enhancing autophagy may therefore be of therapeutic benefit in resistant APL and could broaden the application of differentiation therapy to other cancers. Here we discuss retinoid signaling in hematopoiesis, leukemogenesis, and APL treatment. We highlight autophagy as a potential important regulator in anti-leukemic strategies.

  20. Climate change: potential implications for Ireland's biodiversity

    Science.gov (United States)

    Donnelly, Alison

    2018-03-01

    A national biodiversity and climate change adaptation plan is being developed for Ireland by the Department of Communications, Climate Action, and Environment. In order to inform such a plan, it was necessary to review and synthesize some of the recent literature pertaining to the impact of climate change on biodiversity in Ireland. Published research on this topic fell within three broad categories: (i) changes in the timing of life-cycle events (phenology) of plants, birds, and insects; (ii) changes in the geographic range of some bird species; and (iii) changes in the suitable climatic zones of key habitats and species. The synthesis revealed evidence of (i) a trend towards earlier spring activity of plants, birds, and insects which may result in a change in ecosystem function; (ii) an increase in the number of bird species; and (iii) both increases and decreases in the suitable climatic area of key habitats and species, all of which are expected to impact Ireland's future biodiversity. This process identified data gaps and limitations in available information both of which could be used to inform a focused research strategy. In addition, it raises awareness of the potential implications of climate change for biodiversity in Ireland and elsewhere and demonstrates the need for biodiversity conservation plans to factor climate change into future designs.

  1. Th17 response and autophagy - main pathways implicated in the development of inflammatory bowel disease by genome-wide association studies: new factors involved in inflammatory bowel disease susceptibility

    Directory of Open Access Journals (Sweden)

    Roberto Díaz-Peña

    2015-09-01

    Full Text Available Inflammatory bowel disease (IBD is an entity that mainly includes ulcerative colitis (UC and Crohn's disease (CD. Improved health care, diet changes, and higher industrialization are associated with an increase in IBD prevalence. This supports the central role of environmental factors in the pathology of this disease. However, IBD also shows a relevant genetic component as shown by high heritability. Classic genetic studies showed relevant associations between IBD susceptibility and genes involved in the immune response. This is consistent with prior theories about IBD development. According to these, contact of the immune system with a high number of harmless antigens from the diet and the bacterial flora should originate tolerance while preserving response against pathogens. Failure to achieve this balance may originate the typical inflammatory response associated with IBD. Recently, genome-wide association studies (GWASs have confirmed the implication of the immune system, particularly the Th17 immune response, previously associated to other autoimmune diseases, and of autophagy. In this paper, the mechanisms involved in these two relevant pathways and their potential role in the pathogenesis of IBD are reviewed.

  2. Membrane proteomics of phagosomes suggests a connection to autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Shui, Wenqing; Sheu, Leslie; Liu, Jun; Smart, Brian; Petzold, Christopher J.; Hsieh, Tsung-yen; Pitcher, Austin; Keasling*, Jay D.; Bertozzi*, Carolyn R.

    2008-11-25

    Phagocytosis is the central process by which macrophage cellsinternalize and eliminate infectious microbes as well as apoptoticcells. During maturation, phagosomes containing engulfed particlesfuse with various endosomal compartments through theaction of regulatory molecules on the phagosomal membrane. Inthis study, we performed a proteomic analysis of the membranefraction from latex bead-containing (LBC) phagosomes isolatedfrom macrophages. The profile, which comprised 546 proteins,suggests diverse functions of the phagosome and potential connectionsto secretory processes, toll-like receptor signaling, andautophagy. Many identified proteins were not previously knownto reside in the phagosome. We characterized several proteins inLBC phagosomes that change in abundance on induction of autophagy,a process that has been previously implicated in the hostdefense against microbial pathogens. These observations suggestcrosstalk between autophagy and phagocytosis that may be relevantto the innate immune response of macrophages.

  3. Autophagy in photodynamic therapy

    African Journals Online (AJOL)

    Autophagy is a conserved intracellular degradation process in which cellular organelles, proteins and invading microbes are degraded by lysosomes. There are three types of autophagy: macroautophagy, mitoautophagy and chaperone- mediated autophagy. This review is focused on macroautophagy which is referred to ...

  4. How Parkinsonian Toxins Dysregulate the Autophagy Machinery

    Directory of Open Access Journals (Sweden)

    Ruben K. Dagda

    2013-11-01

    Full Text Available Since their discovery, Parkinsonian toxins (6-hydroxydopamine, MPP+, paraquat, and rotenone have been widely employed as in vivo and in vitro chemical models of Parkinson’s disease (PD. Alterations in mitochondrial homeostasis, protein quality control pathways, and more recently, autophagy/mitophagy have been implicated in neurotoxin models of PD. Here, we highlight the molecular mechanisms by which different PD toxins dysregulate autophagy/mitophagy and how alterations of these pathways play beneficial or detrimental roles in dopamine neurons. The convergent and divergent effects of PD toxins on mitochondrial function and autophagy/mitophagy are also discussed in this review. Furthermore, we propose new diagnostic tools and discuss how pharmacological modulators of autophagy/mitophagy can be developed as disease-modifying treatments for PD. Finally, we discuss the critical need to identify endogenous and synthetic forms of PD toxins and develop efficient health preventive programs to mitigate the risk of developing PD.

  5. Medicare Part D Roulette, Potential Implications of Random..

    Data.gov (United States)

    U.S. Department of Health & Human Services — Medicare Part D Roulette, Potential Implications of Random Assignment and Plan Restrictions Dual-eligible (Medicare and Medicaid) beneficiaries are randomly assigned...

  6. The interplay between autophagy and ROS in tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Kongara, Sameera [Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ (United States); The Cancer Institute of New Jersey, New Brunswick, NJ (United States); Karantza, Vassiliki, E-mail: karantva@umdnj.edu [Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ (United States); The Cancer Institute of New Jersey, New Brunswick, NJ (United States); Division of Medical Oncology, Department of Internal Medicine, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ (United States)

    2012-11-21

    Reactive oxygen species (ROS) at physiological levels are important cell signaling molecules. However, aberrantly high ROS are intimately associated with disease and commonly observed in cancer. Mitochondria are primary sources of intracellular ROS, and their maintenance is essential to cellular health. Autophagy, an evolutionarily conserved process whereby cytoplasmic components are delivered to lysosomes for degradation, is responsible for mitochondrial turnover and removal of damaged mitochondria. Impaired autophagy is implicated in many pathological conditions, including neurological disorders, inflammatory bowel disease, diabetes, aging, and cancer. The first reports connecting autophagy to cancer showed that allelic loss of the essential autophagy gene BECLIN1 (BECN1) is prevalent in human breast, ovarian, and prostate cancers and that Becn1{sup +/-} mice develop mammary gland hyperplasias, lymphomas, lung and liver tumors. Subsequent studies demonstrated that Atg5{sup -/-} and Atg7{sup -/-} livers give rise to adenomas, Atg4C{sup -/-} mice are susceptible to chemical carcinogenesis, and Bif1{sup -/-} mice are prone to spontaneous tumors, indicating that autophagy defects promote tumorigenesis. Due to defective mitophagy, autophagy-deficient cells accumulate damaged mitochondria and deregulated ROS levels, which likely contribute to their tumor-initiating capacity. However, the role of autophagy in tumorigenesis is complex, as more recent work also revealed tumor dependence on autophagy: autophagy-competent mutant-Ras-expressing cells form tumors more efficiently than their autophagy-deficient counterparts; similarly, FIP200 deficiency suppresses PyMT-driven mammary tumorigenesis. These latter findings are attributed to the fact that tumors driven by powerful oncogenes have high metabolic demands catered to by autophagy. In this review, we discuss the relationship between ROS and autophagy and summarize our current knowledge on their functional interactions

  7. The interplay between autophagy and ROS in tumorigenesis

    International Nuclear Information System (INIS)

    Kongara, Sameera; Karantza, Vassiliki

    2012-01-01

    Reactive oxygen species (ROS) at physiological levels are important cell signaling molecules. However, aberrantly high ROS are intimately associated with disease and commonly observed in cancer. Mitochondria are primary sources of intracellular ROS, and their maintenance is essential to cellular health. Autophagy, an evolutionarily conserved process whereby cytoplasmic components are delivered to lysosomes for degradation, is responsible for mitochondrial turnover and removal of damaged mitochondria. Impaired autophagy is implicated in many pathological conditions, including neurological disorders, inflammatory bowel disease, diabetes, aging, and cancer. The first reports connecting autophagy to cancer showed that allelic loss of the essential autophagy gene BECLIN1 (BECN1) is prevalent in human breast, ovarian, and prostate cancers and that Becn1 +/- mice develop mammary gland hyperplasias, lymphomas, lung and liver tumors. Subsequent studies demonstrated that Atg5 -/- and Atg7 -/- livers give rise to adenomas, Atg4C -/- mice are susceptible to chemical carcinogenesis, and Bif1 -/- mice are prone to spontaneous tumors, indicating that autophagy defects promote tumorigenesis. Due to defective mitophagy, autophagy-deficient cells accumulate damaged mitochondria and deregulated ROS levels, which likely contribute to their tumor-initiating capacity. However, the role of autophagy in tumorigenesis is complex, as more recent work also revealed tumor dependence on autophagy: autophagy-competent mutant-Ras-expressing cells form tumors more efficiently than their autophagy-deficient counterparts; similarly, FIP200 deficiency suppresses PyMT-driven mammary tumorigenesis. These latter findings are attributed to the fact that tumors driven by powerful oncogenes have high metabolic demands catered to by autophagy. In this review, we discuss the relationship between ROS and autophagy and summarize our current knowledge on their functional interactions in tumorigenesis.

  8. Autophagy and Microglia: Novel Partners in Neurodegeneration and Aging.

    Science.gov (United States)

    Plaza-Zabala, Ainhoa; Sierra-Torre, Virginia; Sierra, Amanda

    2017-03-09

    Autophagy is emerging as a core regulator of Central Nervous System (CNS) aging and neurodegeneration. In the brain, it has mostly been studied in neurons, where the delivery of toxic molecules and organelles to the lysosome by autophagy is crucial for neuronal health and survival. However, we propose that the (dys)regulation of autophagy in microglia also affects innate immune functions such as phagocytosis and inflammation, which in turn contribute to the pathophysiology of aging and neurodegenerative diseases. Herein, we first describe the basic concepts of autophagy and its regulation, discuss key aspects for its accurate monitoring at the experimental level, and summarize the evidence linking autophagy impairment to CNS senescence and disease. We focus on acute, chronic, and autoimmunity-mediated neurodegeneration, including ischemia/stroke, Alzheimer's, Parkinson's, and Huntington's diseases, and multiple sclerosis. Next, we describe the actual and potential impact of autophagy on microglial phagocytic and inflammatory function. Thus, we provide evidence of how autophagy may affect microglial phagocytosis of apoptotic cells, amyloid-β, synaptic material, and myelin debris, and regulate the progression of age-associated neurodegenerative diseases. We also discuss data linking autophagy to the regulation of the microglial inflammatory phenotype, which is known to contribute to age-related brain dysfunction. Overall, we update the current knowledge of autophagy and microglia, and highlight as yet unexplored mechanisms whereby autophagy in microglia may contribute to CNS disease and senescence.

  9. The Scavenger Protein Apoptosis Inhibitor of Macrophages (AIM) Potentiates the Antimicrobial Response against Mycobacterium tuberculosis by Enhancing Autophagy

    Science.gov (United States)

    Sanjurjo, Lucía; Amézaga, Núria; Vilaplana, Cristina; Cáceres, Neus; Marzo, Elena; Valeri, Marta; Cardona, Pere-Joan; Sarrias, Maria-Rosa

    2013-01-01

    Apoptosis inhibitor of macrophages (AIM), a scavenger protein secreted by tissue macrophages, is transcriptionally regulated by the nuclear receptor Liver X Receptor (LXR) and Retinoid X Receptor (RXR) heterodimer. Given that LXR exerts a protective immune response against M. tuberculosis, here we analyzed whether AIM is involved in this response. In an experimental murine model of tuberculosis, AIM serum levels peaked dramatically early after infection with M. tuberculosis, providing an in vivo biological link to the disease. We therefore studied the participation of AIM in macrophage response to M. tuberculosis in vitro. For this purpose, we used the H37Rv strain to infect THP-1 macrophages transfected to stably express AIM, thereby increasing infected macrophage survival. Furthermore, the expression of this protein enlarged foam cell formation by enhancing intracellular lipid content. Phagocytosis assays with FITC-labeled M. tuberculosis bacilli indicated that this protein was not involved in bacterial uptake; however, AIM expression decreased the number of intracellular cfus by up to 70% in bacterial killing assays, suggesting that AIM enhances macrophage mycobactericidal activity. Accordingly, M. tuberculosis-infected AIM-expressing cells upregulated the production of reactive oxygen species. Moreover, real-time PCR analysis showed increased mRNA levels of the antimicrobial peptides cathelicidin and defensin 4B. These increases were concomitant with greater cellular concentrations of the autophagy-related molecules Beclin 1 and LC3II, as well as enhanced acidification of mycobacterial phagosomes and LC3 co-localization. In summary, our data support the notion that AIM contributes to key macrophage responses to M. tuberculosis. PMID:24223991

  10. Differential induction of apoptosis and autophagy by pyrrolizidine alkaloid clivorine in human hepatoma Huh-7.5 cells and its toxic implication

    Science.gov (United States)

    Fang, Shoucai; Ho, Wenzhe; Chen, Hui; Liang, Hao; Ye, Li; Tang, Jun

    2017-01-01

    Growing evidence suggests that the pyrrolizidine alkaloids (PAs)-induced hepatotoxicity is mediated by multiple cell death/defence modalities. However, the detailed mechanisms are still lacking. In this study, the hepatotoxic effects of four PAs including three retronecine-type ones (senecionine, seneciphylline and monocrotaline) and one otonecine-type (clivorine) on the proliferation of Huh-7.5 cells and the possible mechanisms were investigated. The results showed that all the PAs could inhibit cell proliferation and induce apoptosis in a concentration-dependent manner. Among them clivorine was the most significant one. In addition to its effect on apoptosis, clivorine treatment could promote autophagy in Huh-7.5 cells, as evidenced by the accumulation of autophagosomes, the enhancement of LC3B expression at the concentrations close to its IC0 value, and the increased conversion of LC3B-I to LC3B-II in the presence of lysosomal inhibitor (chloroquine) and decreased formation of green fluorescent protein (GFP)-LC3 positive puncta in the presence of autophagic sequestration inhibitor (3-methyladenine). Among the other tested PAs, senecionine and seneciphylline also activated autophagy at the same concentrations used for clivorine but monocrotaline did not. Furthermore, our study demonstrated that suppression or enhancement of autophagy resulted in the remarkable enhancement or suppression of senecionine, seneciphylline and clivorine-induced apoptosis at the concentration close to the IC10 for clivorine, respectively, indicating a protective role of autophagy against the PA-induced apoptosis at the low level of exposure. Collectively, our data suggest that PAs in different structures may exert different toxic disturbances on the liver cells. Apoptosis may be one of the most common models of the PA-induced cytotoxicity, while autophagy may be a structure-dependent defence model in the early stage of PA intoxication. Differential induction of apoptosis and autophagy

  11. Autophagy Facilitates Salmonella Replication in HeLa Cells

    Science.gov (United States)

    Yu, Hong B.; Croxen, Matthew A.; Marchiando, Amanda M.; Ferreira, Rosana B. R.; Cadwell, Ken; Foster, Leonard J.; Finlay, B. Brett

    2014-01-01

    ABSTRACT Autophagy is a process whereby a double-membrane structure (autophagosome) engulfs unnecessary cytosolic proteins, organelles, and invading pathogens and delivers them to the lysosome for degradation. We examined the fate of cytosolic Salmonella targeted by autophagy and found that autophagy-targeted Salmonella present in the cytosol of HeLa cells correlates with intracellular bacterial replication. Real-time analyses revealed that a subset of cytosolic Salmonella extensively associates with autophagy components p62 and/or LC3 and replicates quickly, whereas intravacuolar Salmonella shows no or very limited association with p62 or LC3 and replicates much more slowly. Replication of cytosolic Salmonella in HeLa cells is significantly decreased when autophagy components are depleted. Eventually, hyperreplication of cytosolic Salmonella potentiates cell detachment, facilitating the dissemination of Salmonella to neighboring cells. We propose that Salmonella benefits from autophagy for its cytosolic replication in HeLa cells. PMID:24618251

  12. Regulation of Mitochondrial Genome Inheritance by Autophagy and Ubiquitin-Proteasome System: Implications for Health, Fitness, and Fertility

    Directory of Open Access Journals (Sweden)

    Won-Hee Song

    2014-01-01

    Full Text Available Mitochondria, the energy-generating organelles, play a role in numerous cellular functions including adenosine triphosphate (ATP production, cellular homeostasis, and apoptosis. Maternal inheritance of mitochondria and mitochondrial DNA (mtDNA is universally observed in humans and most animals. In general, high levels of mitochondrial heteroplasmy might contribute to a detrimental effect on fitness and disease resistance. Therefore, a disposal of the sperm-derived mitochondria inside fertilized oocytes assures normal preimplantation embryo development. Here we summarize the current research and knowledge concerning the role of autophagic pathway and ubiquitin-proteasome-dependent proteolysis in sperm mitophagy in mammals, including humans. Current data indicate that sperm mitophagy inside the fertilized oocyte could occur along multiple degradation routes converging on autophagic clearance of paternal mitochondria. The influence of assisted reproductive therapies (ART such as intracytoplasmic sperm injection (ICSI, mitochondrial replacement (MR, and assisted fertilization of oocytes from patients of advanced reproductive age on mitochondrial function, inheritance, and fitness and for the development and health of ART babies will be of particular interest to clinical audiences. Altogether, the study of sperm mitophagy after fertilization has implications in the timing of evolution and developmental and reproductive biology and in human health, fitness, and management of mitochondrial disease.

  13. Evaluation of Apoptosis and Autophagy Inducing Potential of Berberis aristata, Azadirachta indica, and Their Synergistic Combinations in Parental and Resistant Human Osteosarcoma Cells

    Science.gov (United States)

    Sengupta, Pracheta; Raman, Sukanya; Chowdhury, Rajdeep; Lohitesh, K.; Saini, Heena; Mukherjee, Sudeshna; Paul, Atish

    2017-01-01

    Cancer is a multifactorial disease and hence can be effectively overcome by a multi-constituently therapeutic strategy. Medicinal plant extracts represent a perfect example of such stratagem. However, minimal studies have been done till date that portray the effect of extraction techniques on the phyto-constituent profile of plant extracts and its impact on anticancer activity. In the present study, we have evaluated the anticancer potential of methanolic extracts of Berberis aristata root and Azadirachta indica seeds prepared by various extraction techniques in human osteosarcoma (HOS) cells. Soxhlation extract of B. aristata (BAM-SX) and sonication extract of A. indica (AIM-SO) were most effective in inducing apoptosis in parental drug sensitive, as well as resistant cell type developed by repeated drug exposure. Generation of reactive oxygen species and cell cycle arrest preceded caspase-mediated apoptosis in HOS cells. Interestingly, inhibition of autophagy enhanced cell death suggesting the cytoprotective role of autophagy. Combination studies of different methanolic extracts of BAM and AIM were performed, among which, the combination of BAM-SO and AIM-SO (BAAISO) was found to show synergism (IC50 10.27 µg/ml) followed by combination of BAM-MC and AIM-MC (BAAIMC) with respect to other combinations in the ratio of 1:1. BAAISO also showed synergism when it was added to cisplatin-resistant HOS cells (HCR). Chromatographic profiling of BAM-SX and AIM-SO by high performance thin layer chromatography resulted in identification of berberine (Rf 0.55), palmitine (Rf 0.50) in BAM-SX and azadirachtin A (Rf 0.36), azadirachtin B (Rf 0.56), nimbin (Rf 0.80), and nimbolide (Rf 0.43) in AIM-SO. The cytotoxic sensitivity obtained can be attributed to the above compounds. Our results highlight the importance of extraction technique and subsequent mechanism of action of multi-constituential B. aristata and A. indica against both sensitive and drug refractory HOS cells. PMID

  14. Evaluation of Apoptosis and Autophagy Inducing Potential of Berberis aristata, Azadirachta indica, and Their Synergistic Combinations in Parental and Resistant Human Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Pracheta Sengupta

    2017-12-01

    Full Text Available Cancer is a multifactorial disease and hence can be effectively overcome by a multi-constituently therapeutic strategy. Medicinal plant extracts represent a perfect example of such stratagem. However, minimal studies have been done till date that portray the effect of extraction techniques on the phyto-constituent profile of plant extracts and its impact on anticancer activity. In the present study, we have evaluated the anticancer potential of methanolic extracts of Berberis aristata root and Azadirachta indica seeds prepared by various extraction techniques in human osteosarcoma (HOS cells. Soxhlation extract of B. aristata (BAM-SX and sonication extract of A. indica (AIM-SO were most effective in inducing apoptosis in parental drug sensitive, as well as resistant cell type developed by repeated drug exposure. Generation of reactive oxygen species and cell cycle arrest preceded caspase-mediated apoptosis in HOS cells. Interestingly, inhibition of autophagy enhanced cell death suggesting the cytoprotective role of autophagy. Combination studies of different methanolic extracts of BAM and AIM were performed, among which, the combination of BAM-SO and AIM-SO (BAAISO was found to show synergism (IC50 10.27 µg/ml followed by combination of BAM-MC and AIM-MC (BAAIMC with respect to other combinations in the ratio of 1:1. BAAISO also showed synergism when it was added to cisplatin-resistant HOS cells (HCR. Chromatographic profiling of BAM-SX and AIM-SO by high performance thin layer chromatography resulted in identification of berberine (Rf 0.55, palmitine (Rf 0.50 in BAM-SX and azadirachtin A (Rf 0.36, azadirachtin B (Rf 0.56, nimbin (Rf 0.80, and nimbolide (Rf 0.43 in AIM-SO. The cytotoxic sensitivity obtained can be attributed to the above compounds. Our results highlight the importance of extraction technique and subsequent mechanism of action of multi-constituential B. aristata and A. indica against both sensitive and drug refractory HOS

  15. Coordinated Upregulation of Mitochondrial Biogenesis and Autophagy in Breast Cancer Cells: The Role of Dynamin Related Protein-1 and Implication for Breast Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Peng Zou

    2016-01-01

    Full Text Available Overactive mitochondrial fission was shown to promote cell transformation and tumor growth. It remains elusive how mitochondrial quality is regulated in such conditions. Here, we show that upregulation of mitochondrial fission protein, dynamin related protein-1 (Drp1, was accompanied with increased mitochondrial biogenesis markers (PGC1α, NRF1, and Tfam in breast cancer cells. However, mitochondrial number was reduced, which was associated with lower mitochondrial oxidative capacity in breast cancer cells. This contrast might be owing to enhanced mitochondrial turnover through autophagy, because an increased population of autophagic vacuoles engulfing mitochondria was observed in the cancer cells. Consistently, BNIP3 (a mitochondrial autophagy marker and autophagic flux were significantly upregulated, indicative of augmented mitochondrial autophagy (mitophagy. The upregulation of Drp1 and BNIP3 was also observed in vivo (human breast carcinomas. Importantly, inhibition of Drp1 significantly suppressed mitochondrial autophagy, metabolic reprogramming, and cancer cell viability. Together, this study reveals coordinated increase of mitochondrial biogenesis and mitophagy in which Drp1 plays a central role regulating breast cancer cell metabolism and survival. Given the emerging evidence of PGC1α contributing to tumor growth, it will be of critical importance to target both mitochondrial biogenesis and mitophagy for effective cancer therapeutics.

  16. Immunologic manifestations of autophagy

    DEFF Research Database (Denmark)

    Deretic, Vojo; Kimura, Tomonori; Timmins, Graham

    2015-01-01

    The broad immunologic roles of autophagy span innate and adaptive immunity and are often manifested in inflammatory diseases. The immune effects of autophagy partially overlap with its roles in metabolism and cytoplasmic quality control but typically expand further afield to encompass unique...... immunologic adaptations. One of the best-appreciated manifestations of autophagy is protection against microbial invasion, but this is by no means limited to direct elimination of intracellular pathogens and includes a stratified array of nearly all principal immunologic processes. This Review summarizes...... the broad immunologic roles of autophagy. Furthermore, it uses the autophagic control of Mycobacterium tuberculosis as a paradigm to illustrate the breadth and complexity of the immune effects of autophagy....

  17. Anti- and pro-tumor functions of autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Galluzzi, Lorenzo; Kepp, Oliver; Vicencio, José-Miguel; Criollo, Alfredo; Maiuri, Maria Chiara; Kroemer, Guido

    2009-09-01

    Autophagy constitutes one of the major responses to stress in eukaryotic cells, and is regulated by a complex network of signaling cascades. Not surprisingly, autophagy is implicated in multiple pathological processes, including infection by pathogens, inflammatory bowel disease, neurodegeneration and cancer. Both oncogenesis and tumor survival are influenced by perturbations of the molecular machinery that controls autophagy. Numerous oncoproteins, including phosphatidylinositol 3-kinase, Akt1 and anti-apoptotic members of the Bcl-2 family suppress autophagy. Conversely, several tumor suppressor proteins (e.g., Atg4c; beclin 1; Bif-1; BH3-only proteins; death-associated protein kinase 1; LKB1/STK11; PTEN; UVRAG) promote the autophagic pathway. This does not entirely apply to p53, one of the most important tumor suppressor proteins, which regulates autophagy in an ambiguous fashion, depending on its subcellular localization. Irrespective of the controversial role of p53, basal levels of autophagy appear to inhibit tumor development. On the contrary, chemotherapy- and metabolic stress-induced activation of the autophagic pathway reportedly contribute to the survival of formed tumors, thereby favoring resistance. In this context, autophagy inhibition would represent a major therapeutic target for chemosensitization. Here, we will review the current knowledge on the dual role of autophagy as an anti- and pro-tumor mechanism.

  18. The Mucosal Immune System and Its Regulation by Autophagy.

    Science.gov (United States)

    Kabat, Agnieszka M; Pott, Johanna; Maloy, Kevin J

    2016-01-01

    The gastrointestinal tract presents a unique challenge to the mucosal immune system, which has to constantly monitor the vast surface for the presence of pathogens, while at the same time maintaining tolerance to beneficial or innocuous antigens. In the intestinal mucosa, specialized innate and adaptive immune components participate in directing appropriate immune responses toward these diverse challenges. Recent studies provide compelling evidence that the process of autophagy influences several aspects of mucosal immune responses. Initially described as a "self-eating" survival pathway that enables nutrient recycling during starvation, autophagy has now been connected to multiple cellular responses, including several aspects of immunity. Initial links between autophagy and host immunity came from the observations that autophagy can target intracellular bacteria for degradation. However, subsequent studies indicated that autophagy plays a much broader role in immune responses, as it can impact antigen processing, thymic selection, lymphocyte homeostasis, and the regulation of immunoglobulin and cytokine secretion. In this review, we provide a comprehensive overview of mucosal immune cells and discuss how autophagy influences many aspects of their physiology and function. We focus on cell type-specific roles of autophagy in the gut, with a particular emphasis on the effects of autophagy on the intestinal T cell compartment. We also provide a perspective on how manipulation of autophagy may potentially be used to treat mucosal inflammatory disorders.

  19. Autophagy is essential for the differentiation of porcine PSCs into insulin-producing cells.

    Science.gov (United States)

    Ren, Lipeng; Yang, Hong; Cui, Yanhua; Xu, Shuanshuan; Sun, Fen; Tian, Na; Hua, Jinlian; Peng, Sha

    2017-07-01

    Porcine pancreatic stem cells (PSCs) are seed cells with potential use for diabetes treatment. Stem cell differentiation requires strict control of protein turnover and lysosomal digestion of organelles. Autophagy is a highly conserved process that controls the turnover of organelles and proteins within cells and contributes to the balance of cellular components. However, whether autophagy plays roles in PSC differentiation remains unknown. In this study, we successfully induced porcine PSCs into insulin-producing cells and found that autophagy was activated during the second induction stage. Inhibition of autophagy in the second stage resulted in reduced differentiational efficiency and impaired glucose-stimulated insulin secretion. Moreover, the expression of active β-catenin increased while autophagy was activated but was suppressed when autophagy was inhibited. Therefore, autophagy is essential to the formation of insulin-producing cells, and the effects of autophagy on differentiation may be regulated by canonical Wnt signalling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. The potential implication of eosinophil activation in the pathogenesis ...

    African Journals Online (AJOL)

    Ehab

    The potential implication of eosinophil activation in the pathogenesis of childhood asthma. INTRODUCTION. Asthma is recognized as an eosinophil mediated inflammation of the airways1. Eosinophils are major contributors to the damage in the airways of asthmatic patients which when activated, degranulate and release ...

  1. Inhibition of the Autophagy Pathway Synergistically Potentiates the Cytotoxic Activity of Givinostat(ITF2357on Human Glioblastoma Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Francesca Angeletti

    2016-10-01

    Full Text Available Increasing evidence highlighted the role of cancer stem cells (CSCs in the development of tumor resistance to therapy, particularly in glioblastoma (GBM. Therefore, the development of new therapies, specifically directed against GBM CSCs, constitutes an important research avenue. Considering the extended range of cancer-related pathways modulated by histone acetylation/deacetylation processes, we studied the anti-proliferative and pro-apoptotic efficacy of givinostat (GVS, a pan-histone deacetylase inhibitor, on cell cultures enriched in CSCs, isolated from nine human GBMs. We report that GVS induced a significant reduction of viability and self-renewal ability in all GBM CSC cultures; conversely, GVS exposure did not cause a significant cytotoxic activity toward differentiated GBM cells and normal mesenchymal human stem cells.Analysing the cellular and molecular mechanisms involved, we demonstrated that GVS affected CSC viability through the activation of programmed cell death pathways. In particular, a marked stimulation of macroautophagy was observed after GVS treatment. To understand the functional link between GVS treatment and autophagy activation, different genetic and pharmacological interfering strategies were used. We show that the up-regulation of the autophagy process, obtained by deprivation of growth factors, induced a reduction of CSC sensitivity to GVS, while the pharmacological inhibition of the autophagy pathway and the silencing of the key autophagy gene ATG7, increased the cell death rate induced by GVS. Altogether these findings suggest that autophagy represents a pro-survival mechanism activated by GBM CSCs to counteract the efficacy of the anti-proliferative activity of GVS. In conclusion, we demonstrate that GVS is a novel pharmacological tool able to target GBM CSC viability and its efficacy can be enhanced by autophagy inhibitory strategies.

  2. Autophagy in protists

    Science.gov (United States)

    Duszenko, Michael; Ginger, Michael L; Brennand, Ana; Gualdrón-López, Melisa; Colombo, Maria-Isabel; Coombs, Graham H; Coppens, Isabelle; Jayabalasingham, Bamini; Langsley, Gordon; de Castro, Solange Lisboa; Menna-Barreto, Rubem; Mottram, Jeremy C; Navarro, Miguel; Rigden, Daniel J; Romano, Patricia S; Stoka, Veronika; Turk, Boris

    2011-01-01

    Autophagy is the degradative process by which eukaryotic cells digest their own components using acid hydrolases within the lysosome. Originally thought to function almost exclusively in providing starving cells with nutrients taken from their own cellular constituents, autophagy is in fact involved in numerous cellular events including differentiation, turnover of macromolecules and organelles and defense against parasitic invaders. During the past 10–20 years, molecular components of the autophagic machinery have been discovered, revealing a complex interactome of proteins and lipids, which, in a concerted way, induce membrane formation to engulf cellular material and target it for lysosomal degradation. Here, our emphasis is autophagy in protists. We discuss experimental and genomic data indicating that the canonical autophagy machinery characterized in animals and fungi appeared prior to the radiation of major eukaryotic lineages. Moreover, we describe how comparative bioinformatics revealed that this canonical machinery has been subject to moderation, outright loss or elaboration on multiple occasions in protist lineages, most probably as a consequence of diverse lifestyle adaptations. We also review experimental studies illustrating how several pathogenic protists either utilize autophagy mechanisms or manipulate host-cell autophagy in order to establish or maintain infection within a host. The essentiality of autophagy for the pathogenicity of many parasites, and the unique features of some of the autophagy-related proteins involved, suggest possible new targets for drug discovery. Further studies of the molecular details of autophagy in protists will undoubtedly enhance our understanding of the diversity and complexity of this cellular phenomenon and the opportunities it offers as a drug target. PMID:20962583

  3. Distinct patterns of autophagy evoked by two benzoxazine derivatives in vascular endothelial cells.

    Science.gov (United States)

    Wang, Li; Dong, ZhiWu; Huang, Bin; Zhao, BaoXiang; Wang, Hua; Zhao, Jing; Kung, HsiangFu; Zhang, ShangLi; Miao, JunYing

    2010-11-01

    Macroautophagy (referred to as autophagy) is an evolutionarily conserved, bulk-destruction process in eukaryotes. During this process, the cytoplasm containing long-lived proteins and organelles is engulfed into double-membrane autophagosomes, and ultimately undergoes enzymatic degradation within lysosomes. Autophagy serves as a prosurvival machinery, or it may contribute to cell death. Accumulating evidence indicates that autophagy is involved in the pathogenesis and intervention of various human diseases. Pharmacological autophagy modulators are arousing interest from biologists and clinical physicians in light of their potential for disease therapy and increasing our understanding of the mechanism of autophagy. In this study, we identified two autophagy enhancers, 6-amino-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine (ABO) and 6,8-dichloro-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine (DBO), in human umbilical vein endothelial cells (HUVEC s) by autophagy assays, and demonstrate that ABO and DBO could stimulate autophagy in an mtor-independent and mtor-dependent manner, respectively; ABO-stimulated autophagy was attributed to the elevation of the Ca2+ channel annexin A7 (ANXA7), whereas DBO's effect was due to the level of intracellular reactive oxygen species (ROS). Importantly, we found that ANXA7 was essential for autophagy induction via modulating the intracellular calcium concentration ([Ca2+]i) in HUVEC s. In summary, our work introduced two distinct autophagy enhancers and highlighted the critical role of ANXA7 in endothelial autophagy.

  4. Chemical Inhibition of Autophagy

    DEFF Research Database (Denmark)

    Baek, Eric; Lin Kim, Che; Gyeom Kim, Mi

    2016-01-01

    Chinese hamster ovary (CHO) cells activate and undergo apoptosis and autophagy for various environmental stresses. Unlike apoptosis, studies on increasing the production of therapeutic proteins in CHO cells by targeting the autophagy pathway are limited. In order to identify the effects of chemical...... autophagy inhibitors on the specific productivity (qp), nine chemical inhibitors that had been reported to target three different phases of autophagy (metformin, dorsomorphin, resveratrol, and SP600125 against initiation and nucleation; 3-MA, wortmannin, and LY294002 against elongation, and chloroquine...... and bafilomycin A1 against autophagosome fusion) were used to treat three recombinant CHO (rCHO) cell lines: the Fc-fusion protein-producing DG44 (DG44-Fc) and DUKX-B11 (DUKX-Fc) and antibody-producing DG44 (DG44-Ab) cell lines. Among the nine chemical inhibitors tested, 3-MA, dorsomorphin, and SP600125...

  5. Impaired Autophagy in the Lipid-Storage Disorder Niemann-Pick Type C1 Disease

    OpenAIRE

    Sarkar, Sovan; Carroll, Bernadette; Buganim, Yosef; Maetzel, Dorothea; Ng, Alex H.M.; Cassady, John P.; Cohen, Malkiel A.; Chakraborty, Souvik; Wang, Haoyi; Spooner, Eric; Ploegh, Hidde; Gsponer, Joerg; Korolchuk, Viktor I.; Jaenisch, Rudolf

    2013-01-01

    Autophagy dysfunction has been implicated in misfolded protein accumulation and cellular toxicity in several diseases. Whether alterations in autophagy also contribute to the pathology of lipid-storage disorders is not clear. Here, we show defective autophagy in Niemann-Pick type C1 (NPC1) disease associated with cholesterol accumulation, where the maturation of autophagosomes is impaired because of defective amphisome formation caused by failure in SNARE machinery, whereas the lysosomal prot...

  6. Autophagy in Trypanosomatids

    Directory of Open Access Journals (Sweden)

    Paul A. M. Michels

    2012-07-01

    Full Text Available Autophagy is a ubiquitous eukaryotic process that also occurs in trypanosomatid parasites, protist organisms belonging to the supergroup Excavata, distinct from the supergroup Opistokontha that includes mammals and fungi. Half of the known yeast and mammalian AuTophaGy (ATG proteins were detected in trypanosomatids, although with low sequence conservation. Trypanosomatids such as Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. are responsible for serious tropical diseases in humans. The parasites are transmitted by insects and, consequently, have a complicated life cycle during which they undergo dramatic morphological and metabolic transformations to adapt to the different environments. Autophagy plays a major role during these transformations. Since inhibition of autophagy affects the transformation, survival and/or virulence of the parasites, the ATGs offer promise for development of drugs against tropical diseases. Furthermore, various trypanocidal drugs have been shown to trigger autophagy-like processes in the parasites. It is inferred that autophagy is used by the parasites in an—not always successful—attempt to cope with the stress caused by the toxic compounds.

  7. VALSARTAN REGULATES MYOCARDIAL AUTOPHAGY AND MITOCHONDRIAL TURNOVER IN EXPERIMENTAL HYPERTENSION

    Science.gov (United States)

    Zhang, Xin; Li, Zi-Lun; Crane, John A.; Jordan, Kyra L.; Pawar, Aditya S.; Textor, Stephen C.; Lerman, Amir; Lerman, Lilach O.

    2014-01-01

    Renovascular hypertension alters cardiac structure and function. Autophagy is activated during left ventricular hypertrophy and linked to adverse cardiac function. The Angiotensin II receptor blocker Valsartan lowers blood pressure and is cardioprotective, but whether it modulates autophagy in the myocardium is unclear. We hypothesized that Valsartan would alleviate autophagy and improve left ventricular myocardial mitochondrial turnover in swine renovascular hypertension. Domestic pigs were randomized to control, unilateral renovascular hypertension, and renovascular hypertension treated with Valsartan (320 mg/day) or conventional triple therapy (Reserpine+hydralazine+hydrochlorothiazide) for 4 weeks post 6-weeks of renovascular hypertension (n=7 each group). Left ventricular remodeling, function and myocardial oxygenation and microcirculation were assessed by multi-detector computer tomography, blood-oxygen-level-dependent magnetic resonance imaging and microcomputer tomography. Myocardial autophagy, markers for mitochondrial degradation and biogenesis, and mitochondrial respiratory-chain proteins were examined ex vivo. Renovascular hypertension induced left ventricular hypertrophy and myocardial hypoxia, enhanced cellular autophagy and mitochondrial degradation, and suppressed mitochondrial biogenesis. Valsartan and triple therapy similarly decreased blood pressure, but Valsartan solely alleviated left ventricular hypertrophy, ameliorated myocardial autophagy and mitophagy, and increased mitochondrial biogenesis. In contrast, triple therapy only slightly attenuated autophagy and preserved mitochondrial proteins, but elicited no improvement in mitophagy. These data suggest a novel potential role of Valsartan in modulating myocardial autophagy and mitochondrial turnover in renovascular hypertension-induced hypertensive heart disease, which may possibly bolster cardiac repair via a blood pressure-independent manner. PMID:24752430

  8. Human Diversity in a Cell Surface Receptor that Inhibits Autophagy.

    Science.gov (United States)

    Chaudhary, Anu; Leite, Mara; Kulasekara, Bridget R; Altura, Melissa A; Ogahara, Cassandra; Weiss, Eli; Fu, Wenqing; Blanc, Marie-Pierre; O'Keeffe, Michael; Terhorst, Cox; Akey, Joshua M; Miller, Samuel I

    2016-07-25

    Mutations in genes encoding autophagy proteins have been associated with human autoimmune diseases, suggesting that diversity in autophagy responses could be associated with disease susceptibility or severity. A cellular genome-wide association study (GWAS) screen was performed to explore normal human diversity in responses to rapamycin, a microbial product that induces autophagy. Cells from several human populations demonstrated variability in expression of a cell surface receptor, CD244 (SlamF4, 2B4), that correlated with changes in rapamycin-induced autophagy. High expression of CD244 and receptor activation with its endogenous ligand CD48 inhibited starvation- and rapamycin-induced autophagy by promoting association of CD244 with the autophagy complex proteins Vps34 and Beclin-1. The association of CD244 with this complex reduced Vps34 lipid kinase activity. Lack of CD244 is associated with auto-antibody production in mice, and lower expression of human CD244 has previously been implicated in severity of human rheumatoid arthritis and systemic lupus erythematosus, indicating that increased autophagy as a result of low levels of CD244 may alter disease outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Nucleotide-oligomerizing domain-1 (NOD1) receptor activation induces pro-inflammatory responses and autophagy in human alveolar macrophages.

    Science.gov (United States)

    Juárez, Esmeralda; Carranza, Claudia; Hernández-Sánchez, Fernando; Loyola, Elva; Escobedo, Dante; León-Contreras, Juan Carlos; Hernández-Pando, Rogelio; Torres, Martha; Sada, Eduardo

    2014-09-25

    Nucleotide-binding oligomerizing domain-1 (NOD1) is a cytoplasmic receptor involved in recognizing bacterial peptidoglycan fragments that localize to the cytosol. NOD1 activation triggers inflammation, antimicrobial mechanisms and autophagy in both epithelial cells and murine macrophages. NOD1 mediates intracellular pathogen clearance in the lungs of mice; however, little is known about NOD1's role in human alveolar macrophages (AMs) or its involvement in Mycobacterium tuberculosis (Mtb) infection. AMs, monocytes (MNs), and monocyte-derived macrophages (MDMs) from healthy subjects were assayed for NOD1 expression. Cells were stimulated with the NOD1 ligand Tri-DAP and cytokine production and autophagy were assessed. Cells were infected with Mtb and treated with Tri-DAP post-infection. CFUs counting determined growth control, and autophagy protein recruitment to pathogen localization sites was analyzed by immunoelectron microscopy. NOD1 was expressed in AMs, MDMs and to a lesser extent MNs. Tri-DAP stimulation induced NOD1 up-regulation and a significant production of IL1β, IL6, IL8, and TNFα in AMs and MDMs; however, the level of NOD1-dependent response in MNs was limited. Autophagy activity determined by expression of proteins Atg9, LC3, IRGM and p62 degradation was induced in a NOD1-dependent manner in AMs and MDMs but not in MNs. Infected AMs could be activated by stimulation with Tri-DAP to control the intracellular growth of Mtb. In addition, recruitment of NOD1 and the autophagy proteins IRGM and LC3 to the Mtb localization site was observed in infected AMs after treatment with Tri-DAP. NOD1 is involved in AM and MDM innate responses, which include proinflammatory cytokines and autophagy, with potential implications in the killing of Mtb in humans.

  10. Methamphetamine-induced neurotoxicity linked to UPS dysfunction and autophagy related changes that can be modulated by PKCδ in dopaminergic neuronal cells

    Science.gov (United States)

    Lin, Mengshien; Shivalingappa, Prashanth Chandramani; Jin, Huajun; Ghosh, Anamitra; Anantharam, Vellareddy; Ali, Syed; Kanthasamy, Anumantha G.; Kanthasamy, Arthi

    2012-01-01

    A compromised protein degradation machinery has been implicated in methamphetamine (MA)-induced neurodegeneration. However, the signaling mechanisms that induce autophagy and UPS dysfunction are not well understood. The present study investigates the contributions of PKC delta (PKCδ) mediated signaling events in MA-induced autophagy, UPS dysfunction and cell death. Using an in vitro mesencephalic dopaminergic cell culture model, we demonstrate that MA-induced early induction of autophagy is associated with reduction in proteasomal function and concomitant dissipation of mitochondrial membrane potential (MMP), followed by significantly increased of PKCδ activation, caspase-3 activation, accumulation of ubiquitin positive aggregates and microtubule associated light chain-3 (LC3-II) levels. Interestingly, siRNA mediated knockdown of PKCδ or overexpression of cleavage resistant mutant of PKCδ dramatically reduced MA-induced autophagy, proteasomal function, and associated accumulation of ubiquitinated protein aggregates, which closely paralleled cell survival. Importantly, when autophagy was inhibited either pharmacologically (3-MA) or genetically (siRNA mediated silencing of LC3), the dopaminergic cells became sensitized to MA-induced apoptosis through caspase-3 activation. Conversely, overexpression of LC3 partially protected against MA-induced apoptotic cell death, suggesting a neuroprotective role for autophagy in MA-induced neurotoxicity. Notably, rat striatal tissue isolated from MA treated rats also exhibited elevated LC3-II, ubiquitinated protein levels, and PKCδ cleavage. Taken together, our data demonstrate that MA-induced autophagy serves as an adaptive strategy for inhibiting mitochondria mediated apoptotic cell death and degradation of aggregated proteins. Our results also suggest that the sustained activation of PKCδ leads to UPS dysfunction, resulting in the activation of caspase-3 mediated apoptotic cell death in the nigrostriatal dopaminergic

  11. Andrographolide Analogue Induces Apoptosis and Autophagy Mediated Cell Death in U937 Cells by Inhibition of PI3K/Akt/mTOR Pathway.

    Directory of Open Access Journals (Sweden)

    Deepak Kumar

    Full Text Available Current chemotherapeutic agents based on apoptosis induction are lacking in desired efficacy. Therefore, there is continuous effort to bring about new dimension in control and gradual eradication of cancer by means of ever evolving therapeutic strategies. Various forms of PCD are being increasingly implicated in anti-cancer therapy and the complex interplay among them is vital for the ultimate fate of proliferating cells. We elaborated and illustrated the underlying mechanism of the most potent Andrographolide analogue (AG-4 mediated action that involved the induction of dual modes of cell death-apoptosis and autophagy in human leukemic U937 cells.AG-4 induced cytotoxicity was associated with redox imbalance and apoptosis which involved mitochondrial depolarisation, altered apoptotic protein expressions, activation of the caspase cascade leading to cell cycle arrest. Incubation with caspase inhibitor Z-VAD-fmk or Bax siRNA decreased cytotoxic efficacy of AG-4 emphasising critical roles of caspase and Bax. In addition, AG-4 induced autophagy as evident from LC3-II accumulation, increased Atg protein expressions and autophagosome formation. Pre-treatment with 3-MA or Atg 5 siRNA suppressed the cytotoxic effect of AG-4 implying the pro-death role of autophagy. Furthermore, incubation with Z-VAD-fmk or Bax siRNA subdued AG-4 induced autophagy and pre-treatment with 3-MA or Atg 5 siRNA curbed AG-4 induced apoptosis-implying that apoptosis and autophagy acted as partners in the context of AG-4 mediated action. AG-4 also inhibited PI3K/Akt/mTOR pathway. Inhibition of mTOR or Akt augmented AG-4 induced apoptosis and autophagy signifying its crucial role in its mechanism of action.Thus, these findings prove the dual ability of AG-4 to induce apoptosis and autophagy which provide a new perspective to it as a potential molecule targeting PCD for future cancer therapeutics.

  12. Proteomics Insights into Autophagy.

    Science.gov (United States)

    Cudjoe, Emmanuel K; Saleh, Tareq; Hawkridge, Adam M; Gewirtz, David A

    2017-10-01

    Autophagy, a conserved cellular process by which cells recycle their contents either to maintain basal homeostasis or in response to external stimuli, has for the past two decades become one of the most studied physiological processes in cell biology. The 2016 Nobel Prize in Medicine and Biology awarded to Dr. Ohsumi Yoshinori, one of the first scientists to characterize this cellular mechanism, attests to its importance. The induction and consequent completion of the process of autophagy results in wide ranging changes to the cellular proteome as well as the secretome. MS-based proteomics affords the ability to measure, in an unbiased manner, the ubiquitous changes that occur when autophagy is initiated and progresses in the cell. The continuous improvements and advances in mass spectrometers, especially relating to ionization sources and detectors, coupled with advances in proteomics experimental design, has made it possible to study autophagy, among other process, in great detail. Innovative labeling strategies and protein separation techniques as well as complementary methods including immuno-capture/blotting/staining have been used in proteomics studies to provide more specific protein identification. In this review, we will discuss recent advances in proteomics studies focused on autophagy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Prohibitin 1 modulates mitochondrial stress-related autophagy in human colonic epithelial cells.

    Directory of Open Access Journals (Sweden)

    Arwa S Kathiria

    Full Text Available Autophagy is an adaptive response to extracellular and intracellular stress by which cytoplasmic components and organelles, including damaged mitochondria, are degraded to promote cell survival and restore cell homeostasis. Certain genes involved in autophagy confer susceptibility to Crohn's disease. Reactive oxygen species and pro-inflammatory cytokines such as tumor necrosis factor α (TNFα, both of which are increased during active inflammatory bowel disease, promote cellular injury and autophagy via mitochondrial damage. Prohibitin (PHB, which plays a role in maintaining normal mitochondrial respiratory function, is decreased during active inflammatory bowel disease. Restoration of colonic epithelial PHB expression protects mice from experimental colitis and combats oxidative stress. In this study, we investigated the potential role of PHB in modulating mitochondrial stress-related autophagy in intestinal epithelial cells.We measured autophagy activation in response to knockdown of PHB expression by RNA interference in Caco2-BBE and HCT116 WT and p53 null cells. The effect of exogenous PHB expression on TNFα- and IFNγ-induced autophagy was assessed. Autophagy was inhibited using Bafilomycin A(1 or siATG16L1 during PHB knockdown and the affect on intracellular oxidative stress, mitochondrial membrane potential, and cell viability were determined. The requirement of intracellular ROS in siPHB-induced autophagy was assessed using the ROS scavenger N-acetyl-L-cysteine.TNFα and IFNγ-induced autophagy inversely correlated with PHB protein expression. Exogenous PHB expression reduced basal autophagy and TNFα-induced autophagy. Gene silencing of PHB in epithelial cells induces mitochondrial autophagy via increased intracellular ROS. Inhibition of autophagy during PHB knockdown exacerbates mitochondrial depolarization and reduces cell viability.Decreased PHB levels coupled with dysfunctional autophagy renders intestinal epithelial cells

  14. Autophagy in plant pathogenic fungi.

    Science.gov (United States)

    Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

    2016-09-01

    Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Autophagy in HCV Infection: Keeping Fat and Inflammation at Bay

    Directory of Open Access Journals (Sweden)

    Tiziana Vescovo

    2014-01-01

    Full Text Available Hepatitis C virus (HCV infection is one of the main causes of chronic liver disease. Viral persistence and pathogenesis rely mainly on the ability of HCV to deregulate specific host processes, including lipid metabolism and innate immunity. Recently, autophagy has emerged as a cellular pathway, playing a role in several aspects of HCV infection. This review summarizes current knowledge on the molecular mechanisms that link the HCV life cycle with autophagy machinery. In particular, we discuss the role of HCV/autophagy interaction in dysregulating inflammation and lipid homeostasis and its potential for translational applications in the treatment of HCV-infected patients.

  16. Nanomaterials and Autophagy: New Insights in Cancer Treatment

    International Nuclear Information System (INIS)

    Panzarini, Elisa; Inguscio, Valentina; Tenuzzo, Bernardetta Anna; Carata, Elisabetta; Dini, Luciana

    2013-01-01

    Autophagy represents a cell’s response to stress. It is an evolutionarily conserved process with diversified roles. Indeed, it controls intracellular homeostasis by degradation and/or recycling intracellular metabolic material, supplies energy, provides nutrients, eliminates cytotoxic materials and damaged proteins and organelles. Moreover, autophagy is involved in several diseases. Recent evidences support a relationship between several classes of nanomaterials and autophagy perturbation, both induction and blockade, in many biological models. In fact, the autophagic mechanism represents a common cellular response to nanomaterials. On the other hand, the dynamic nature of autophagy in cancer biology is an intriguing approach for cancer therapeutics, since during tumour development and therapy, autophagy has been reported to trigger both an early cell survival and a late cell death. The use of nanomaterials in cancer treatment to deliver chemotherapeutic drugs and target tumours is well known. Recently, autophagy modulation mediated by nanomaterials has become an appealing notion in nanomedicine therapeutics, since it can be exploited as adjuvant in chemotherapy or in the development of cancer vaccines or as a potential anti-cancer agent. Herein, we summarize the effects of nanomaterials on autophagic processes in cancer, also considering the therapeutic outcome of synergism between nanomaterials and autophagy to improve existing cancer therapies

  17. Autophagy-Related Deubiquitinating Enzymes Involved in Health and Disease

    Directory of Open Access Journals (Sweden)

    Fouzi El Magraoui

    2015-10-01

    Full Text Available Autophagy is an evolutionarily-conserved process that delivers diverse cytoplasmic components to the lysosomal compartment for either recycling or degradation. This involves the removal of protein aggregates, the turnover of organelles, as well as the elimination of intracellular pathogens. In this situation, when only specific cargoes should be targeted to the lysosome, the potential targets can be selectively marked by the attachment of ubiquitin in order to be recognized by autophagy-receptors. Ubiquitination plays a central role in this process, because it regulates early signaling events during the induction of autophagy and is also used as a degradation-tag on the potential autophagic cargo protein. Here, we review how the ubiquitin-dependent steps of autophagy are balanced or counteracted by deubiquitination events. Moreover, we highlight the functional role of the corresponding deubiquitinating enzymes and discuss how they might be involved in the occurrence of cancer, neurodegenerative diseases or infection with pathogenic bacteria.

  18. Overweight in elderly people induces impaired autophagy in skeletal muscle.

    Science.gov (United States)

    Potes, Yaiza; de Luxán-Delgado, Beatriz; Rodriguez-González, Susana; Guimarães, Marcela Rodrigues Moreira; Solano, Juan J; Fernández-Fernández, María; Bermúdez, Manuel; Boga, Jose A; Vega-Naredo, Ignacio; Coto-Montes, Ana

    2017-09-01

    Sarcopenia is the gradual loss of skeletal muscle mass, strength and quality associated with aging. Changes in body composition, especially in skeletal muscle and fat mass are crucial steps in the development of chronic diseases. We studied the effect of overweight on skeletal muscle tissue in elderly people without reaching obesity to prevent this extreme situation. Overweight induces a progressive protein breakdown reflected as a progressive withdrawal of anabolism against the promoted catabolic state leading to muscle wasting. Protein turnover is regulated by a network of signaling pathways. Muscle damage derived from overweight displayed by oxidative and endoplasmic reticulum (ER) stress induces inflammation and insulin resistance and forces the muscle to increase requirements from autophagy mechanisms. Our findings showed that failure of autophagy in the elderly deprives it to deal with the cell damage caused by overweight. This insufficiently efficient autophagy leads to an accumulation of p62 and NBR1, which are robust markers of protein aggregations. This impaired autophagy affects myogenesis activity. Depletion of myogenic regulatory factors (MRFs) without links to variations in myostatin levels in overweight patients suggest a possible reduction of satellite cells in muscle tissue, which contributes to declined muscle quality. This discovery has important implications that improve the understanding of aged-related atrophy caused by overweight and demonstrates how impaired autophagy is one of the main responsible mechanisms that aggravate muscle wasting. Therefore, autophagy could be an interesting target for therapeutic interventions in humans against muscle impairment diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. The role of autophagy in microbial infection and immunity

    Directory of Open Access Journals (Sweden)

    Desai M

    2015-01-01

    Full Text Available Mayura Desai,1 Rong Fang,2 Jiaren Sun11Department of Microbiology and Immunology, 2Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX, USAAbstract: The autophagy pathway represents an evolutionarily conserved cell recycling process that is activated in response to nutrient deprivation and other stress signals. Over the years, it has been linked to an array of cellular functions. Equally, a wide range of cell-intrinsic, as well as extracellular, factors have been implicated in the induction of the autophagy pathway. Microbial infections represent one such factor that can not only activate autophagy through specific mechanisms but also manipulate the response to the invading microbe's advantage. Moreover, in many cases, particularly among viruses, the pathway has been shown to be intricately involved in the replication cycle of the pathogen. Conversely, autophagy also plays a role in combating the infection process, both through direct destruction of the pathogen and as one of the key mediating factors in the host defense mechanisms of innate and adaptive immunity. Further, the pathway also plays a role in controlling the pathogenesis of infectious diseases by regulating inflammation. In this review, we discuss various interactions between pathogens and the cellular autophagic response and summarize the immunological functions of the autophagy pathway.Keywords: autophagy, xenophagy, antiviral, antibacterial

  20. Dopamine Oxidation and Autophagy

    Directory of Open Access Journals (Sweden)

    Patricia Muñoz

    2012-01-01

    Full Text Available The molecular mechanisms involved in the neurodegenerative process of Parkinson's disease remain unclear. Currently, there is a general agreement that mitochondrial dysfunction, α-synuclein aggregation, oxidative stress, neuroinflammation, and impaired protein degradation are involved in the neurodegeneration of dopaminergic neurons containing neuromelanin in Parkinson's disease. Aminochrome has been proposed to play an essential role in the degeneration of dopaminergic neurons containing neuromelanin by inducing mitochondrial dysfunction, oxidative stress, the formation of neurotoxic α-synuclein protofibrils, and impaired protein degradation. Here, we discuss the relationship between the oxidation of dopamine to aminochrome, the precursor of neuromelanin, autophagy dysfunction in dopaminergic neurons containing neuromelanin, and the role of dopamine oxidation to aminochrome in autophagy dysfunction in dopaminergic neurons. Aminochrome induces the following: (i the formation of α-synuclein protofibrils that inactivate chaperone-mediated autophagy; (ii the formation of adducts with α- and β-tubulin, which induce the aggregation of the microtubules required for the fusion of autophagy vacuoles and lysosomes.

  1. DNA damage and autophagy

    International Nuclear Information System (INIS)

    Rodriguez-Rocha, Humberto; Garcia-Garcia, Aracely; Panayiotidis, Mihalis I.; Franco, Rodrigo

    2011-01-01

    Both exogenous and endogenous agents are a threat to DNA integrity. Exogenous environmental agents such as ultraviolet (UV) and ionizing radiation, genotoxic chemicals and endogenous byproducts of metabolism including reactive oxygen species can cause alterations in DNA structure (DNA damage). Unrepaired DNA damage has been linked to a variety of human disorders including cancer and neurodegenerative disease. Thus, efficient mechanisms to detect DNA lesions, signal their presence and promote their repair have been evolved in cells. If DNA is effectively repaired, DNA damage response is inactivated and normal cell functioning resumes. In contrast, when DNA lesions cannot be removed, chronic DNA damage triggers specific cell responses such as cell death and senescence. Recently, DNA damage has been shown to induce autophagy, a cellular catabolic process that maintains a balance between synthesis, degradation, and recycling of cellular components. But the exact mechanisms by which DNA damage triggers autophagy are unclear. More importantly, the role of autophagy in the DNA damage response and cellular fate is unknown. In this review we analyze evidence that supports a role for autophagy as an integral part of the DNA damage response.

  2. Hyperferritinemia and iron metabolism in Gaucher disease: Potential pathophysiological implications.

    Science.gov (United States)

    Regenboog, Martine; van Kuilenburg, André B P; Verheij, Joanne; Swinkels, Dorine W; Hollak, Carla E M

    2016-11-01

    Gaucher disease (GD) is characterized by large amounts of lipid-storing macrophages and is associated with accumulation of iron. High levels of ferritin are a hallmark of the disease. The precise mechanism underlying the changes in iron metabolism has not been elucidated. A systematic search was conducted to summarize available evidence from the literature on iron metabolism in GD and its potential pathophysiological implications. We conclude that in GD, a chronic low grade inflammation state can lead to high ferritin levels and increased hepcidin transcription with subsequent trapping of ferritin in macrophages. Extensive GD manifestations with severe anemia or extreme splenomegaly can lead to a situation of iron-overload resembling hemochromatosis. We hypothesize that specifically this latter situation carries a risk for the occurrence of associated conditions such as the increased cancer risk, metabolic syndrome and neurodegeneration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Autophagy in C. elegans development.

    Science.gov (United States)

    Palmisano, Nicholas J; Meléndez, Alicia

    2018-04-27

    Autophagy involves the sequestration of cytoplasmic contents in a double-membrane structure referred to as the autophagosome and the degradation of its contents upon delivery to lysosomes. Autophagy activity has a role in multiple biological processes during the development of the nematode Caenorhabditis elegans. Basal levels of autophagy are required to remove aggregate prone proteins, paternal mitochondria, and spermatid-specific membranous organelles. During larval development, autophagy is required for the remodeling that occurs during dauer development, and autophagy can selectively degrade components of the miRNA-induced silencing complex, and modulate miRNA-mediated silencing. Basal levels of autophagy are important in synapse formation and in the germ line, to promote the proliferation of proliferating stem cells. Autophagy activity is also required for the efficient removal of apoptotic cell corpses by promoting phagosome maturation. Finally, autophagy is also involved in lipid homeostasis and in the aging process. In this review, we first describe the molecular complexes involved in the process of autophagy, its regulation, and mechanisms for cargo recognition. In the second section, we discuss the developmental contexts where autophagy has been shown to be important. Studies in C. elegans provide valuable insights into the physiological relevance of this process during metazoan development. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Cheng-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Graduate Institute of Pharmaceutical Science and Technology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan (China); Kuan, Yu-Hsiang [Department of Pharmacology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pharmacy, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Ou, Yen-Chuan; Li, Jian-Ri [Division of Urology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Wu, Chih-Cheng [Department of Anesthesiology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Department of Financial and Computational Mathematics, Providence University, Taichung 433, Taiwan (China); Pan, Pin-Ho [Department of Pediatrics, Tungs’ Taichung MetroHarbor Hospital, Taichung 435, Taiwan (China); Chen, Wen-Ying [Department of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Huang, Hsuan-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Chen, Chun-Jung, E-mail: cjchen@vghtc.gov.tw [Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Institute of Biomedical Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Center for General Education, Tunghai University, Taichung 407, Taiwan (China); Department of Nursing, HungKuang University, Taichung 433, Taiwan (China)

    2014-09-10

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK.

  5. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    International Nuclear Information System (INIS)

    Chang, Cheng-Yi; Kuan, Yu-Hsiang; Ou, Yen-Chuan; Li, Jian-Ri; Wu, Chih-Cheng; Pan, Pin-Ho; Chen, Wen-Ying; Huang, Hsuan-Yi; Chen, Chun-Jung

    2014-01-01

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK

  6. Autophagy-Related Deubiquitinating Enzymes Involved in Health and Disease

    OpenAIRE

    El Magraoui, Fouzi; Reidick, Christina; Meyer, Hemut E.; Platta, Harald W.

    2015-01-01

    Autophagy is an evolutionarily-conserved process that delivers diverse cytoplasmic components to the lysosomal compartment for either recycling or degradation. This involves the removal of protein aggregates, the turnover of organelles, as well as the elimination of intracellular pathogens. In this situation, when only specific cargoes should be targeted to the lysosome, the potential targets can be selectively marked by the attachment of ubiquitin in order to be recognized by autophagy-recep...

  7. Changing shapes of glycogen-autophagy nexus in neurons: perspective from a rare epilepsy.

    Science.gov (United States)

    Singh, Pankaj Kumar; Singh, Sweta

    2015-01-01

    In brain, glycogen metabolism is predominantly restricted to astrocytes but it also indirectly supports neuronal functions. Increased accumulation of glycogen in neurons is mysteriously pathogenic triggering neurodegeneration as seen in "Lafora disease" (LD) and in other transgenic animal models of neuronal glycogen accumulation. LD is a fatal neurodegenerative disorder with excessive glycogen inclusions in neurons. Autophagy, a pathway for bulk degradation of obsolete cellular constituents also degrades metabolites like lipid and glycogen. Recently, defects in this pathway emerged as a plausible reason for glycogen accumulation in neurons in LD, although some contradictions prevail. Albeit surprising, a reciprocal regulation of autophagy by glycogen in neurons has also just been proposed. Notably, increasing evidences of interaction between proteins of autophagy and glycogen metabolism from diverse model systems indicate a conserved, dynamic, and regulatory cross-talk between these two pathways. Concerning these findings, we herein provide certain models for the molecular basis of this cross-talk and discuss its potential implication in the pathophysiology of LD.

  8. Autophagy inhibitor 3-methyladenine protects against endothelial cell barrier dysfunction in acute lung injury.

    Science.gov (United States)

    Slavin, Spencer A; Leonard, Antony; Grose, Valerie; Fazal, Fabeha; Rahman, Arshad

    2018-03-01

    Autophagy is an evolutionarily conserved cellular process that facilitates the continuous recycling of intracellular components (organelles and proteins) and provides an alternative source of energy when nutrients are scarce. Recent studies have implicated autophagy in many disorders, including pulmonary diseases. However, the role of autophagy in endothelial cell (EC) barrier dysfunction and its relevance in the context of acute lung injury (ALI) remain uncertain. Here, we provide evidence that autophagy is a critical component of EC barrier disruption in ALI. Using an aerosolized bacterial lipopolysaccharide (LPS) inhalation mouse model of ALI, we found that administration of the autophagy inhibitor 3-methyladenine (3-MA), either prophylactically or therapeutically, markedly reduced lung vascular leakage and tissue edema. 3-MA was also effective in reducing the levels of proinflammatory mediators and lung neutrophil sequestration induced by LPS. To test the possibility that autophagy in EC could contribute to lung vascular injury, we addressed its role in the mechanism of EC barrier disruption. Knockdown of ATG5, an essential regulator of autophagy, attenuated thrombin-induced EC barrier disruption, confirming the involvement of autophagy in the response. Similarly, exposure of cells to 3-MA, either before or after thrombin, protected against EC barrier dysfunction by inhibiting the cleavage and loss of vascular endothelial cadherin at adherens junctions, as well as formation of actin stress fibers. 3-MA also reversed LPS-induced EC barrier disruption. Together, these data imply a role of autophagy in lung vascular injury and reveal the protective and therapeutic utility of 3-MA against ALI.

  9. Chloroquine inhibits autophagy and deteriorates the mitochondrial dysfunction and apoptosis in hypoxic rat neurons.

    Science.gov (United States)

    Li, Peng; Hao, Lei; Guo, Yan-Yan; Yang, Guang-Lu; Mei, Hua; Li, Xiao-Hua; Zhai, Qiong-Xiang

    2018-06-01

    Mitochondrial dysfunction (MD) and apoptosis in the neurons are associated with neonatal hypoxic-ischemic (HI) encephalopathy (HIE). The present study was to explore the influence of autophagy on the induction of MD and apoptosis in the neurons in a neonatal HIE rats and in hypoxia-treated neurons in vitro. Ten-day-old HI rat pups were sacrificed for brain pathological examination and immunohistochemical analysis. The induction of autophagy, apoptosis and MD were also determined in the neurons under hypoxia, with or without autophagy inhibitor, chloroquine (CQ) treatment. HI treatment caused atrophy and apoptosis of neurons, with a significantly increased levels of apoptosis- and autophagy-associated proteins, such as cleaved caspase 3 and the B subunit of autophagy-related microtubule-associated protein 1 light chain 3 (LC3-B). in vitro experiments demonstrated that the hypoxia induced autophagy in neurons, as was inhibited by CQ. The hypoxia-induced cytochrome c release, cleaved caspase 3 and cleaved caspase 9 were aggravated by CQ. Moreover, there were higher levels of reactive oxygen species, more mitochondrial superoxide and less mitochondrial membrane potential in the CQ-treated neurons under hypoxia than in the neurons singularly under hypoxia. Apoptosis and autophagy were induced in HI neonatal rat neurons, autophagy inhibition deteriorates the hypoxia-induced neuron MD and apoptosis. It implies a neuroprotection of autophagy in the hypoxic-ischemic encephalopathy. Administration of autophagy inducer agents might be promising in HIE treatment. Copyright © 2018. Published by Elsevier Inc.

  10. The Role of AKT/mTOR Pathway in Stress Response to UV-Irradiation: Implication in Skin Carcinogenesis by Regulation of Apoptosis, Autophagy and Senescence

    Science.gov (United States)

    Strozyk, Elwira; Kulms, Dagmar

    2013-01-01

    Induction of DNA damage by UVB and UVA radiation may generate mutations and genomic instability leading to carcinogenesis. Therefore, skin cells being repeatedly exposed to ultraviolet (UV) light have acquired multilayered protective mechanisms to avoid malignant transformation. Besides extensive DNA repair mechanisms, the damaged skin cells can be eliminated by induction of apoptosis, which is mediated through the action of tumor suppressor p53. In order to prevent the excessive loss of skin cells and to maintain the skin barrier function, apoptotic pathways are counteracted by anti-apoptotic signaling including the AKT/mTOR pathway. However, AKT/mTOR not only prevents cell death, but is also active in cell cycle transition and hyper-proliferation, thereby also counteracting p53. In turn, AKT/mTOR is tuned down by the negative regulators being controlled by the p53. This inhibition of AKT/mTOR, in combination with transactivation of damage-regulated autophagy modulators, guides the p53-mediated elimination of damaged cellular components by autophagic clearance. Alternatively, p53 irreversibly blocks cell cycle progression to prevent AKT/mTOR-driven proliferation, thereby inducing premature senescence. Conclusively, AKT/mTOR via an extensive cross talk with p53 influences the UV response in the skin with no black and white scenario deciding over death or survival. PMID:23887651

  11. Simulated degradation of biochar and its potential environmental implications

    International Nuclear Information System (INIS)

    Liu, Zhaoyun; Demisie, Walelign; Zhang, Mingkui

    2013-01-01

    A simulated oxidation technique was used to examine the impacts of degradation on the surface properties of biochar and the potential implications of the changes in biochar properties were discussed. To simulate the short- and long-term environmental degradation, mild and harsh degradation were employed. Results showed that after mild degradation, the biochar samples showed significant reductions in surface area and pore volumes. After harsh degradation, the biochar samples revealed dramatic variations in their surface chemistry, surface area, pore volumes, morphology and adsorption properties. The results clearly indicate that changes of biochar surface properties were affected by biochar types and oxidative conditions. It is suggested that biochar surface properties are likely to be gradually altered during environmental exposure. This implies that these changes have potential effects for altering the physicochemical properties of biochar amended soils. -- Highlights: •Mild and harsh degradation were employed to simulate natural degradation of biochar. •Mild degradation could reduce the surface area and micropore volumes of biochar. •Harsh degradation caused severe changes of all of the biochar surface properties. •Biochar types and oxidative conditions may dominate the changes of its properties. -- The simulated degradation of biochar in this study could provide a mechanism for forecasting short- or long-term environmental degradation of biochar

  12. Autophagy and lysosomal dysfunction as emerging mechanisms of nanomaterial toxicity

    Directory of Open Access Journals (Sweden)

    Stern Stephan T

    2012-06-01

    Full Text Available Abstract The study of the potential risks associated with the manufacture, use, and disposal of nanoscale materials, and their mechanisms of toxicity, is important for the continued advancement of nanotechnology. Currently, the most widely accepted paradigms of nanomaterial toxicity are oxidative stress and inflammation, but the underlying mechanisms are poorly defined. This review will highlight the significance of autophagy and lysosomal dysfunction as emerging mechanisms of nanomaterial toxicity. Most endocytic routes of nanomaterial cell uptake converge upon the lysosome, making the lysosomal compartment the most common intracellular site of nanoparticle sequestration and degradation. In addition to the endo-lysosomal pathway, recent evidence suggests that some nanomaterials can also induce autophagy. Among the many physiological functions, the lysosome, by way of the autophagy (macroautophagy pathway, degrades intracellular pathogens, and damaged organelles and proteins. Thus, autophagy induction by nanoparticles may be an attempt to degrade what is perceived by the cell as foreign or aberrant. While the autophagy and endo-lysosomal pathways have the potential to influence the disposition of nanomaterials, there is also a growing body of literature suggesting that biopersistent nanomaterials can, in turn, negatively impact these pathways. Indeed, there is ample evidence that biopersistent nanomaterials can cause autophagy and lysosomal dysfunctions resulting in toxicological consequences.

  13. A Primary Human Trophoblast Model to Study the Effect of Inflammation Associated with Maternal Obesity on Regulation of Autophagy in the Placenta.

    Science.gov (United States)

    Simon, Bailey; Bucher, Matthew; Maloyan, Alina

    2017-09-27

    Maternal obesity is associated with an increased risk of adverse perinatal outcomes that are likely mediated by compromised placental function that can be attributed to, in part, the dysregulation of autophagy. Aberrant changes in the expression of autophagy regulators in the placentas from obese pregnancies may be regulated by inflammatory processes associated with both obesity and pregnancy. Described here is a protocol for sampling of villous tissue and isolation of villous cytotrophoblasts from the term human placenta for primary cell culture. This is followed by a method for simulating the inflammatory milieu in the obese intrauterine environment by treating primary trophoblasts from lean pregnancies with tumor necrosis factor alpha (TNFα), a proinflammatory cytokine that is elevated in obesity and in pregnancy. Through the implementation of the protocol described here, it is found that exposure to exogenous TNFα regulates the expression of Rubicon, a negative regulator of autophagy, in trophoblasts from lean pregnancies with female fetuses. While a variety of biological factors in the obese intrauterine environment maintain the potential to modulate critical pathways in trophoblasts, this ex vivo system is especially useful for determining if expression patterns observed in vivo in human placentas with maternal obesity are a direct result of TNFα signaling. Ultimately, this approach affords the opportunity to parse out the regulatory and molecular implications of inflammation associated with maternal obesity on autophagy and other critical cellular pathways in trophoblasts that have the potential to impact placental function.

  14. Autophagy as a Possible Underlying Mechanism of Nanomaterial Toxicity

    Directory of Open Access Journals (Sweden)

    Vanessa Cohignac

    2014-07-01

    Full Text Available The rapid development of nanotechnologies is raising safety concerns because of the potential effects of engineered nanomaterials on human health, particularly at the respiratory level. Since the last decades, many in vivo studies have been interested in the pulmonary effects of different classes of nanomaterials. It has been shown that some of them can induce toxic effects, essentially depending on their physico-chemical characteristics, but other studies did not identify such effects. Inflammation and oxidative stress are currently the two main mechanisms described to explain the observed toxicity. However, the exact underlying mechanism(s still remain(s unknown and autophagy could represent an interesting candidate. Autophagy is a physiological process in which cytoplasmic components are digested via a lysosomal pathway. It has been shown that autophagy is involved in the pathogenesis and the progression of human diseases, and is able to modulate the oxidative stress and pro-inflammatory responses. A growing amount of literature suggests that a link between nanomaterial toxicity and autophagy impairment could exist. In this review, we will first summarize what is known about the respiratory effects of nanomaterials and we will then discuss the possible involvement of autophagy in this toxicity. This review should help understand why autophagy impairment could be taken as a promising candidate to fully understand nanomaterials toxicity.

  15. Regulation of Autophagy by Kinases

    International Nuclear Information System (INIS)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda

    2011-01-01

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets

  16. Regulation of Autophagy by Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda, E-mail: alakananda.basu@unthsc.edu [Department of Molecular Biology and Immunology, Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States)

    2011-06-09

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets.

  17. Regulation of Autophagy by Kinases

    Science.gov (United States)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda

    2011-01-01

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets. PMID:24212825

  18. Regulation of Autophagy by Kinases

    Directory of Open Access Journals (Sweden)

    Savitha Sridharan

    2011-06-01

    Full Text Available Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK and protein kinase C that are often deregulated in cancer and are important therapeutic targets.

  19. Tumor cells induce the cancer associated fibroblast phenotype via caveolin-1 degradation: implications for breast cancer and DCIS therapy with autophagy inhibitors.

    Science.gov (United States)

    Martinez-Outschoorn, Ubaldo E; Pavlides, Stephanos; Whitaker-Menezes, Diana; Daumer, Kristin M; Milliman, Janet N; Chiavarina, Barbara; Migneco, Gemma; Witkiewicz, Agnieszka K; Martinez-Cantarin, Maria P; Flomenberg, Neal; Howell, Anthony; Pestell, Richard G; Lisanti, Michael P; Sotgia, Federica

    2010-06-15

    Loss of stromal caveolin 1 (Cav-1) is a novel biomarker for cancer-associated fibroblasts that predicts poor clinical outcome in breast cancer and DCIS patients. We hypothesized that epithelial cancer cells may have the ability to drive Cav-1 downregulation in adjacent normal fibroblasts, thereby promoting the cancer associated fibroblast phenotype. To test this hypothesis directly, here we developed a novel co-culture model employing (i) human breast cancer cells (MCF7), and (ii) immortalized fibroblasts (hTERT-BJ1), which are grown under defined experimental conditions. Importantly, we show that co-culture of immortalized human fibroblasts with MCF7 breast cancer cells leads to Cav-1 downregulation in fibroblasts. These results were also validated using primary cultures of normal human mammary fibroblasts co-cultured with MCF7 cells. In this system, we show that Cav-1 downregulation is mediated by autophagic/lysosomal degradation, as pre-treatment with lysosome-specific inhibitors rescues Cav-1 expression. Functionally, we demonstrate that fibroblasts co-cultured with MCF7 breast cancer cells acquire a cancer associated fibroblast phenotype, characterized by Cav-1 downregulation, increased expression of myofibroblast markers and extracellular matrix proteins, and constitutive activation of TGFβ/Smad2 signaling. siRNA-mediated Cav-1 downregulation mimics several key changes that occur in co-cultured fibroblasts, clearly indicating that a loss of Cav-1 is a critical initiating factor, driving stromal fibroblast activation during tumorigenesis. As such, this co-culture system can now be used as an experimental model for generating "synthetic" cancer associated fibroblasts (CAFs). More specifically, these "synthetic" CAFs could be used for drug screening to identify novel therapeutics that selectively target the Cav-1-negative tumor micro-environment. Our findings also suggest that chloroquine, or other autophagy/lysosome inhibitors, may be useful as anti

  20. The role of autophagy in THP-1 macrophages resistance to HIV- vpr-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hua-ying, E-mail: zhouhuaying_2004@126.com; Zheng, Yu-huang; He, Yan; Chen, Zi; He, Bo

    2017-02-01

    Macrophages are resistant to cell death and are one of HIV reservoirs. HIV viral protein Vpr has the potential to promote infection of and survival of macrophages, which could be a highly significant factor in the development and/or maintenance of macrophage viral reservoirs. However, the impact of vpr on macrophages resistance to apoptosis is yet to be comprehended. Autophagy is a cell survival mechanism under stress state. In this study, we investigated whether autophagy is involved in macrophages resistant to vpr-induced apoptosis. Using the THP1 macrophages, we studied the interconnection between macrophages resistance to apoptosis and autophagy. We found that vpr is able to trigger autophagy in transfected THP-1 macrophages confirmed by electron microscopy (EM) and western blot analysis, and inhibition of autophagy with 3MA increased vpr-induced apoptosis. The results indicate that autophagy may be responsible for maintenance of macrophage HIV reservoirs. - Highlights: • HIV Vpr is able to trigger autophagy in transfected THP-1 macrophages. • Autophagy inhibition increases vpr-transfected THP1-macrophages apoptosis. • Autophagy is involved in THP-1 macrophages resistant to vpr-induced apoptosis.

  1. GOLGA2 loss causes fibrosis with autophagy in the mouse lung and liver.

    Science.gov (United States)

    Park, Sungjin; Kim, Sanghwa; Kim, Min Jung; Hong, Youngeun; Lee, Ah Young; Lee, Hyunji; Tran, Quangdon; Kim, Minhee; Cho, Hyeonjeong; Park, Jisoo; Kim, Kwang Pyo; Park, Jongsun; Cho, Myung-Haing

    2018-01-01

    Autophagy is a biological recycling process via the self-digestion of organelles, proteins, and lipids for energy-consuming differentiation and homeostasis. The Golgi serves as a donor of the double-membraned phagophore for autophagosome assembly. In addition, recent studies have demonstrated that pulmonary and hepatic fibrosis is accompanied by autophagy. However, the relationships among Golgi function, autophagy, and fibrosis are unclear. Here, we show that the deletion of GOLGA2, encoding a cis-Golgi protein, induces autophagy with Golgi disruption. The induction of autophagy leads to fibrosis along with the reduction of subcellular lipid storage (lipid droplets and lamellar bodies) by autophagy in the lung and liver. GOLGA2 knockout mice clearly demonstrated fibrosis features such as autophagy-activated cells, densely packed hepatocytes, increase of alveolar macrophages, and decrease of alveolar surfactant lipids (dipalmitoylphosphatidylcholine). Therefore, we confirmed the associations among Golgi function, fibrosis, and autophagy. Moreover, GOLGA2 knockout mice may be a potentially valuable animal model for studying autophagy-induced fibrosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Autophagy and neurodegenerative disorders

    Institute of Scientific and Technical Information of China (English)

    Evangelia Kesidou; Roza Lagoudaki; Olga Touloumi; Kyriaki-Nefeli Poulatsidou; Constantina Simeonidou

    2013-01-01

    Accumulation of aberrant proteins and inclusion bodies are hallmarks in most neurodegenerative diseases. Consequently, these aggregates within neurons lead to toxic effects, overproduction of reactive oxygen species and oxidative stress. Autophagy is a significant intracel ular mechanism that removes damaged organelles and misfolded proteins in order to maintain cel homeostasis. Excessive or insufficient autophagic activity in neurons leads to altered homeostasis and influences their survival rate, causing neurodegeneration. The review article provides an update of the role of autophagic process in representative chronic and acute neurodegenerative disorders.

  3. High Altitude Emissions of Black Carbon Aerosols: Potential Climate Implications

    Science.gov (United States)

    Satheesh, S. K.

    2017-12-01

    these, it is hypothesized that such intrusions of black carbon to lower stratosphere and its consequent longer residence time in the stratosphere, would have significant implications for stratospheric chemistry, considering the known ozone depleting potential of black carbon aerosols.

  4. The Effects of Kaempferol-Inhibited Autophagy on Osteoclast Formation.

    Science.gov (United States)

    Kim, Chang-Ju; Shin, Sang-Hun; Kim, Bok-Joo; Kim, Chul-Hoon; Kim, Jung-Han; Kang, Hae-Mi; Park, Bong-Soo; Kim, In-Ryoung

    2018-01-02

    Kaempferol, a flavonoid compound, is derived from the rhizome of Kaempferia galanga L ., which is used in traditional medicine in Asia. Autophagy has pleiotropic functions that are involved in cell growth, survival, nutrient supply under starvation, defense against pathogens, and antigen presentation. There are many studies dealing with the inhibitory effects of natural flavonoids in bone resorption. However, no studies have explained the relationship between the autophagic and inhibitory processes of osteoclastogenesis by natural flavonoids. The present study was undertaken to investigate the inhibitory effects of osteoclastogenesis through the autophagy inhibition process stimulated by kaempferol in murin macrophage (RAW 264.7) cells. The cytotoxic effect of Kaempferol was investigated by MTT assay. The osteoclast differentiation and autophagic process were confirmed via tartrate-resistant acid phosphatase (TRAP) staining, pit formation assay, western blot, and real-time PCR. Kaempferol controlled the expression of autophagy-related factors and in particular, it strongly inhibited the expression of p62/SQSTM1. In the western blot and real time-PCR analysis, when autophagy was suppressed with the application of 3-Methyladenine (3-MA) only, osteoclast and apoptosis related factors were not significantly affected. However, we found that after cells were treated with kaempferol, these factors inhibited autophagy and activated apoptosis. Therefore, we presume that kaempferol-inhibited autophagy activated apoptosis by degradation of p62/SQSTM1. Further study of the p62/SQSTM1 gene as a target in the autophagy mechanism, may help to delineate the potential role of kaempferol in the treatment of bone metabolism disorders.

  5. Estrogen receptor α induces prosurvival autophagy in papillary thyroid cancer via stimulating reactive oxygen species and extracellular signal regulated kinases.

    Science.gov (United States)

    Fan, Dahua; Liu, Shirley Y W; van Hasselt, C Andrew; Vlantis, Alexander C; Ng, Enders K W; Zhang, Haitao; Dong, Yujuan; Ng, Siu Kwan; Chu, Ryan; Chan, Amy B W; Du, Jing; Wei, Wei; Liu, Xiaoling; Liu, Zhimin; Xing, Mingzhao; Chen, George G

    2015-04-01

    The incidence of papillary thyroid cancer (PTC) shows a predominance in females, with a male:female ratio of 1:3, and none of the known risk factors are associated with gender difference. Increasing evidence indicates a role of estrogen in thyroid tumorigenesis, but the mechanism involved remains largely unknown. This study aimed to assess the contribution of autophagy to estrogen receptor α (ERα)-mediated growth of PTC. The expression of ERα in thyroid tissue of patients with PTC tissues was analyzed. Cell viability, proliferation, and apoptosis were evaluated after chemical and genetic inhibition of autophagy. Autophagy in PTC cell lines BCPAP and BCPAP-ERα was assessed. ERα expression was increased in PTC tissues compared with the adjacent nontumor tissues. Estrogen induced autophagy in an ERα-dependent manner. Autophagy induced by estrogen/ERα is associated with generation of reactive oxygen species, activation of ERK1/2, and the survival/growth of PTC cells. Chemical and genetic inhibition of autophagy dramatically decreased tumor cell survival and promoted apoptosis, confirming the positive role of autophagy in the growth of PTC. ERα contributes to the growth of PTC by enhancing an important prosurvival catabolic process, autophagy, in PTC cells. The inhibition of autophagy promotes apoptosis, implicating a novel strategy for the treatment of ERα-positive PTC.

  6. Tuning flux: autophagy as a target of heart disease therapy

    Science.gov (United States)

    Xie, Min; Morales, Cyndi R.; Lavandero, Sergio; Hill, Joseph A.

    2013-01-01

    Purpose of review Despite maximum medical and mechanical support therapy, heart failure remains a relentlessly progressive disorder with substantial morbidity and mortality. Autophagy, an evolutionarily conserved process of cellular cannibalization, has been implicated in virtually all forms of cardiovascular disease. Indeed, its role is context dependent, antagonizing or promoting disease depending on the circumstance. Here, we review current understanding of the role of autophagy in the pathogenesis of heart failure and explore this pathway as a target of therapeutic intervention. Recent findings In preclinical models of heart disease, cardiomyocyte autophagic flux is activated; indeed, its role in disease pathogenesis is the subject of intense investigation to define mechanism. Similarly, in failing human heart of a variety of etiologies, cardiomyocyte autophagic activity is upregulated, and therapy, such as with mechanical support systems, elicits declines in autophagy activity. However, when suppression of autophagy is complete, rapid and catastrophic cell death occurs, consistent with a model in which basal autophagic flux is required for proteostasis. Thus, a narrow zone of ‘optimal’ autophagy seems to exist. The challenge moving forward is to tune the stress-triggered autophagic response within that ‘sweet spot’ range for therapeutic benefit. Summary Whereas we have known for some years of the participation of lysosomal mechanisms in heart disease, it is only recently that upstream mechanisms (autophagy) are being explored. The challenge for the future is to dissect the underlying circuitry and titrate the response into an optimal, proteostasis-promoting range in hopes of mitigating the ever-expanding epidemic of heart failure. PMID:21415729

  7. Cytotoxic Autophagy in Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Khushboo Sharma

    2014-06-01

    Full Text Available Autophagy is a process of cellular self-digestion, whereby the cell degrades subcellular materials in order to generate energy and metabolic precursors in order to prolong survival, classically under conditions of nutrient deprivation. Autophagy can also involve the degradation of damaged or aged organelles, and misfolded or damaged proteins to eliminate these components that might otherwise be deleterious to cellular survival. Consequently, autophagy has generally been considered a prosurvival response. Many, if not most chemotherapeutic drugs and radiation also promote autophagy, which is generally considered a cytoprotective response, in that its inhibition frequently promotes apoptotic cells death. Furthermore, it has been shown that conventional chemotherapeutic drugs and radiation alone rarely induce a form of autophagy that leads to cell death. However, there are multiple examples in the literature where newer chemotherapeutic agents, drug combinations or drugs in combination with radiation promote autophagic cell death. This review will describe autophagic cell death induced in breast tumor cells, lung cancer cells as well as glioblastoma, demonstrating that it cannot be concluded that stress induced autophagy is, of necessity, cytoprotective in function.

  8. Autophagy in DNA Damage Response

    Directory of Open Access Journals (Sweden)

    Piotr Czarny

    2015-01-01

    Full Text Available DNA damage response (DDR involves DNA repair, cell cycle regulation and apoptosis, but autophagy is also suggested to play a role in DDR. Autophagy can be activated in response to DNA-damaging agents, but the exact mechanism underlying this activation is not fully understood, although it is suggested that it involves the inhibition of mammalian target of rapamycin complex 1 (mTORC1. mTORC1 represses autophagy via phosphorylation of the ULK1/2–Atg13–FIP200 complex thus preventing maturation of pre-autophagosomal structures. When DNA damage occurs, it is recognized by some proteins or their complexes, such as poly(ADPribose polymerase 1 (PARP-1, Mre11–Rad50–Nbs1 (MRN complex or FOXO3, which activate repressors of mTORC1. SQSTM1/p62 is one of the proteins whose levels are regulated via autophagic degradation. Inhibition of autophagy by knockout of FIP200 results in upregulation of SQSTM1/p62, enhanced DNA damage and less efficient damage repair. Mitophagy, one form of autophagy involved in the selective degradation of mitochondria, may also play role in DDR. It degrades abnormal mitochondria and can either repress or activate apoptosis, but the exact mechanism remains unknown. There is a need to clarify the role of autophagy in DDR, as this process may possess several important biomedical applications, involving also cancer therapy.

  9. Heme oxygenase-1 enhances autophagy in podocytes as a protective mechanism against high glucose-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Chenglong [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China); Zheng, Haining [Department of Hyperbaric Oxygen, Nanjing General Hospital of Nanjing Military Command, Nanjing (China); Huang, Shanshan; You, Na; Xu, Jiarong; Ye, Xiaolong; Zhu, Qun; Feng, Yamin; You, Qiang; Miao, Heng [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China); Ding, Dafa, E-mail: dingdafa2004@aliyun.com [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China); Lu, Yibing, E-mail: luyibing2004@126.com [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China)

    2015-10-01

    Injury and loss of podocytes play vital roles in diabetic nephropathy progression. Emerging evidence suggests autophagy, which is induced by multiple stressors including hyperglycemia, plays a protective role. Meanwhile, heme oxygenase-1 (HO-1) possesses powerful anti-apoptotic properties. Therefore, we investigated the impact of autophagy on podocyte apoptosis under diabetic conditions and its association with HO-1. Mouse podocytes were cultured in vitro; apoptosis was detected by flow cytometry. Transmission electron microscopy and biochemical autophagic flux assays were used to measure the autophagy markers microtubule-associated protein 1 light chain 3-II (LC3-II) and beclin-1. LC3-II and beclin-1 expression peaked 12–24 h after exposing podocytes to high glucose. Inhibition of autophagy with 3-methyladenine or Beclin-1 siRNAs or Atg 5 siRNAs sensitized cells to apoptosis, suggesting autophagy is a survival mechanism. HO-1 inactivation inhibited autophagy, which aggravated podocyte injury in vitro. Hemin-induced autophagy also protected podocytes from hyperglycemia in vitro and was abrogated by HO-1 siRNA. Adenosine monophosphate-activated protein kinase phosphorylation was higher in hemin-treated and lower in HO-1 siRNA-treated podocytes. Suppression of AMPK activity reversed HO-1-mediated Beclin-1 upregulation and autophagy, indicating HO-1-mediated autophagy is AMPK dependent. These findings suggest HO-1 induction and regulation of autophagy are potential therapeutic targets for diabetic nephropathy. - Highlights: • High glucose leads to increased autophagy in podocytes at an early stage. • The early autophagic response protects against high glucose-induced apoptosis. • Heme oxygenase-1 enhances autophagy and decreases high glucose -mediated apoptosis. • Heme oxygenase-1 induces autophagy through the activation of AMPK.

  10. Heme oxygenase-1 enhances autophagy in podocytes as a protective mechanism against high glucose-induced apoptosis

    International Nuclear Information System (INIS)

    Dong, Chenglong; Zheng, Haining; Huang, Shanshan; You, Na; Xu, Jiarong; Ye, Xiaolong; Zhu, Qun; Feng, Yamin; You, Qiang; Miao, Heng; Ding, Dafa; Lu, Yibing

    2015-01-01

    Injury and loss of podocytes play vital roles in diabetic nephropathy progression. Emerging evidence suggests autophagy, which is induced by multiple stressors including hyperglycemia, plays a protective role. Meanwhile, heme oxygenase-1 (HO-1) possesses powerful anti-apoptotic properties. Therefore, we investigated the impact of autophagy on podocyte apoptosis under diabetic conditions and its association with HO-1. Mouse podocytes were cultured in vitro; apoptosis was detected by flow cytometry. Transmission electron microscopy and biochemical autophagic flux assays were used to measure the autophagy markers microtubule-associated protein 1 light chain 3-II (LC3-II) and beclin-1. LC3-II and beclin-1 expression peaked 12–24 h after exposing podocytes to high glucose. Inhibition of autophagy with 3-methyladenine or Beclin-1 siRNAs or Atg 5 siRNAs sensitized cells to apoptosis, suggesting autophagy is a survival mechanism. HO-1 inactivation inhibited autophagy, which aggravated podocyte injury in vitro. Hemin-induced autophagy also protected podocytes from hyperglycemia in vitro and was abrogated by HO-1 siRNA. Adenosine monophosphate-activated protein kinase phosphorylation was higher in hemin-treated and lower in HO-1 siRNA-treated podocytes. Suppression of AMPK activity reversed HO-1-mediated Beclin-1 upregulation and autophagy, indicating HO-1-mediated autophagy is AMPK dependent. These findings suggest HO-1 induction and regulation of autophagy are potential therapeutic targets for diabetic nephropathy. - Highlights: • High glucose leads to increased autophagy in podocytes at an early stage. • The early autophagic response protects against high glucose-induced apoptosis. • Heme oxygenase-1 enhances autophagy and decreases high glucose -mediated apoptosis. • Heme oxygenase-1 induces autophagy through the activation of AMPK

  11. Prions: Potential Threat to Mankind and Dental Implications

    Directory of Open Access Journals (Sweden)

    Ajay R Bhoosreddy

    2010-01-01

    Full Text Available Prion diseases are fatal, infectious, neurodegenerative disorders with special implications for infection control in the health care system. The causative agent is highly resistant to routine disinfection and sterilization processes and has been transmitted during health care interactions. Thus, it is important to use evidence gained through research and case reports to minimize risk of infection. There is no data suggesting that prions are transmitted easily during dental sittings but there remains a rare risk of such transmission if appropriate infection measures are not adhered to.

  12. Heavy ion irradiation induces autophagy in irradiated C2C12 myoblasts and their bystander cells

    International Nuclear Information System (INIS)

    Hino, Mizuki; Tajika, Yuki; Hamada, Nobuyuki

    2010-01-01

    Autophagy is one of the major processes involved in the degradation of intracellular materials. Here, we examined the potential impact of heavy ion irradiation on the induction of autophagy in irradiated C2C12 mouse myoblasts and their non-targeted bystander cells. In irradiated cells, ultrastructural analysis revealed the accumulation of autophagic structures at various stages of autophagy (id est (i.e.) phagophores, autophagosomes and autolysosomes) within 20 min after irradiation. Multivesicular bodies (MVBs) and autolysosomes containing MVBs (amphisomes) were also observed. Heavy ion irradiation increased the staining of microtubule-associated protein 1 light chain 3 and LysoTracker Red (LTR). Such enhanced staining was suppressed by an autophagy inhibitor 3-methyladenine. In addition to irradiated cells, bystander cells were also positive with LTR staining. Altogether, these results suggest that heavy ion irradiation induces autophagy not only in irradiated myoblasts but also in their bystander cells. (author)

  13. The Role of Autophagy in the Pathogenesis of Diabetic Nephropathy

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    Kosuke Yamahara

    2013-01-01

    Full Text Available Diabetic nephropathy is a leading cause of end-stage renal disease worldwide. The multipronged drug approach targeting blood pressure and serum levels of glucose, insulin, and lipids fails to fully prevent the onset and progression of diabetic nephropathy. Therefore, a new therapeutic target to combat diabetic nephropathy is required. Autophagy is a catabolic process that degrades damaged proteins and organelles in mammalian cells and plays a critical role in maintaining cellular homeostasis. The accumulation of proteins and organelles damaged by hyperglycemia and other diabetes-related metabolic changes is highly associated with the development of diabetic nephropathy. Recent studies have suggested that autophagy activity is altered in both podocytes and proximal tubular cells under diabetic conditions. Autophagy activity is regulated by both nutrient state and intracellular stresses. Under diabetic conditions, an altered nutritional state due to nutrient excess may interfere with the autophagic response stimulated by intracellular stresses, leading to exacerbation of organelle dysfunction and diabetic nephropathy. In this review, we discuss new findings showing the relationships between autophagy and diabetic nephropathy and suggest the therapeutic potential of autophagy in diabetic nephropathy.

  14. Ammonia Induces Autophagy through Dopamine Receptor D3 and MTOR

    Science.gov (United States)

    Li, Zhiyuan; Ji, Xinmiao; Wang, Wenchao; Liu, Juanjuan; Liang, Xiaofei; Wu, Hong; Liu, Jing; Eggert, Ulrike S.; Liu, Qingsong

    2016-01-01

    Hyperammonemia is frequently seen in tumor microenvironments as well as in liver diseases where it can lead to severe brain damage or death. Ammonia induces autophagy, a mechanism that tumor cells may use to protect themselves from external stresses. However, how cells sense ammonia has been unclear. Here we show that culture medium alone containing Glutamine can generate milimolar of ammonia at 37 degrees in the absence of cells. In addition, we reveal that ammonia acts through the G protein-coupled receptor DRD3 (Dopamine receptor D3) to induce autophagy. At the same time, ammonia induces DRD3 degradation, which involves PIK3C3/VPS34-dependent pathways. Ammonia inhibits MTOR (mechanistic target of Rapamycin) activity and localization in cells, which is mediated by DRD3. Therefore, ammonia has dual roles in autophagy: one to induce autophagy through DRD3 and MTOR, the other to increase autophagosomal pH to inhibit autophagic flux. Our study not only adds a new sensing and output pathway for DRD3 that bridges ammonia sensing and autophagy induction, but also provides potential mechanisms for the clinical consequences of hyperammonemia in brain damage, neurodegenerative diseases and tumors. PMID:27077655

  15. MicroRNA-155 promotes autophagy to eliminate intracellular mycobacteria by targeting Rheb.

    Science.gov (United States)

    Wang, Jinli; Yang, Kun; Zhou, Lin; Minhaowu; Wu, Yongjian; Zhu, Min; Lai, Xiaomin; Chen, Tao; Feng, Lianqiang; Li, Meiyu; Huang, Chunyu; Zhong, Qiu; Huang, Xi

    2013-01-01

    Mycobacterium tuberculosis is a hard-to-eradicate intracellular pathogen that infects one-third of the global population. It can live within macrophages owning to its ability to arrest phagolysosome biogenesis. Autophagy has recently been identified as an effective way to control the intracellular mycobacteria by enhancing phagosome maturation. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-mycobacterial response. Both in vivo and in vitro studies showed that miR-155 expression was significantly enhanced after mycobacterial infection. Forced expression of miR-155 accelerated the autophagic response in macrophages, thus promoting the maturation of mycobacterial phagosomes and decreasing the survival rate of intracellular mycobacteria, while transfection with miR-155 inhibitor increased mycobacterial survival. However, macrophage-mediated mycobacterial phagocytosis was not affected after miR-155 overexpression or inhibition. Furthermore, blocking autophagy with specific inhibitor 3-methyladenine or silencing of autophagy related gene 7 (Atg7) reduced the ability of miR-155 to promote autophagy and mycobacterial elimination. More importantly, our study demonstrated that miR-155 bound to the 3'-untranslated region of Ras homologue enriched in brain (Rheb), a negative regulator of autophagy, accelerated the process of autophagy and sequential killing of intracellular mycobacteria by suppressing Rheb expression. Our results reveal a novel role of miR-155 in regulating autophagy-mediated mycobacterial elimination by targeting Rheb, and provide potential targets for clinical treatment.

  16. MicroRNA-155 promotes autophagy to eliminate intracellular mycobacteria by targeting Rheb.

    Directory of Open Access Journals (Sweden)

    Jinli Wang

    Full Text Available Mycobacterium tuberculosis is a hard-to-eradicate intracellular pathogen that infects one-third of the global population. It can live within macrophages owning to its ability to arrest phagolysosome biogenesis. Autophagy has recently been identified as an effective way to control the intracellular mycobacteria by enhancing phagosome maturation. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-mycobacterial response. Both in vivo and in vitro studies showed that miR-155 expression was significantly enhanced after mycobacterial infection. Forced expression of miR-155 accelerated the autophagic response in macrophages, thus promoting the maturation of mycobacterial phagosomes and decreasing the survival rate of intracellular mycobacteria, while transfection with miR-155 inhibitor increased mycobacterial survival. However, macrophage-mediated mycobacterial phagocytosis was not affected after miR-155 overexpression or inhibition. Furthermore, blocking autophagy with specific inhibitor 3-methyladenine or silencing of autophagy related gene 7 (Atg7 reduced the ability of miR-155 to promote autophagy and mycobacterial elimination. More importantly, our study demonstrated that miR-155 bound to the 3'-untranslated region of Ras homologue enriched in brain (Rheb, a negative regulator of autophagy, accelerated the process of autophagy and sequential killing of intracellular mycobacteria by suppressing Rheb expression. Our results reveal a novel role of miR-155 in regulating autophagy-mediated mycobacterial elimination by targeting Rheb, and provide potential targets for clinical treatment.

  17. Involvement of autophagy upregulation in 3,4-methylenedioxymethamphetamine ('ecstasy')-induced serotonergic neurotoxicity.

    Science.gov (United States)

    Li, I-Hsun; Ma, Kuo-Hsing; Kao, Tzu-Jen; Lin, Yang-Yi; Weng, Shao-Ju; Yen, Ting-Yin; Chen, Lih-Chi; Huang, Yuahn-Sieh

    2016-01-01

    It has been suggested that autophagy plays pathogenetic roles in cerebral ischemia, brain trauma, and neurodegenerative disorders. 3,4-Methylenedioxymethamphetamine (MDMA or ecstasy) is an illicit drug that causes long-term serotonergic neurotoxicity in the brain. Apoptosis and necrosis have been implicated in MDMA-induced neurotoxicity, but the role of autophagy in MDMA-elicited serotonergic toxicity has not been investigated. The present study aimed to examine the contribution of autophagy to neurotoxicity in serotonergic neurons in in vitro and in vivo animal models challenged with MDMA. Here, we demonstrated that in cultured rat serotonergic neurons, MDMA exposure induced LC3B-densely stained autophagosome formation, accompanying by a decrease in neurite outgrowth. Autophagy inhibitor 3-methyladenine (3-MA) significantly attenuated MDMA-induced autophagosome accumulation, and ameliorated MDMA-triggered serotonergic neurite damage and neuron death. In contrast, enhanced autophagy flux by rapamycin or impaired autophagosome clearance by bafilomycin A1 led to more autophagosome accumulation in serotonergic neurons and aggravated neurite degeneration. In addition, MDMA-induced autophagy activation in cultured serotonergic neurons might be mediated by serotonin transporter (SERT). In an in vivo animal model administered MDMA, neuroimaging showed that 3-MA protected the serotonin system against MDMA-induced downregulation of SERT evaluated by animal-PET with 4-[(18)F]-ADAM, a SERT radioligand. Taken together, our results demonstrated that MDMA triggers upregulation of autophagy in serotonergic neurons, which appears to be detrimental to neuronal growth. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Pathogenic mutation in the ALS/FTD gene, CCNF, causes elevated Lys48-linked ubiquitylation and defective autophagy.

    Science.gov (United States)

    Lee, Albert; Rayner, Stephanie L; Gwee, Serene S L; De Luca, Alana; Shahheydari, Hamideh; Sundaramoorthy, Vinod; Ragagnin, Audrey; Morsch, Marco; Radford, Rowan; Galper, Jasmin; Freckleton, Sarah; Shi, Bingyang; Walker, Adam K; Don, Emily K; Cole, Nicholas J; Yang, Shu; Williams, Kelly L; Yerbury, Justin J; Blair, Ian P; Atkin, Julie D; Molloy, Mark P; Chung, Roger S

    2018-01-01

    Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative disorders that have common molecular and pathogenic characteristics, such as aberrant accumulation and ubiquitylation of TDP-43; however, the mechanisms that drive this process remain poorly understood. We have recently identified CCNF mutations in familial and sporadic ALS and FTD patients. CCNF encodes cyclin F, a component of an E3 ubiquitin-protein ligase (SCF cyclin F ) complex that is responsible for ubiquitylating proteins for degradation by the ubiquitin-proteasome system. In this study, we examined the ALS/FTD-causing p.Ser621Gly (p.S621G) mutation in cyclin F and its effect upon downstream Lys48-specific ubiquitylation in transfected Neuro-2A and SH-SY5Y cells. Expression of mutant cyclin F S621G caused increased Lys48-specific ubiquitylation of proteins in neuronal cells compared to cyclin F WT . Proteomic analysis of immunoprecipitated Lys48-ubiquitylated proteins from mutant cyclin F S621G -expressing cells identified proteins that clustered within the autophagy pathway, including sequestosome-1 (p62/SQSTM1), heat shock proteins, and chaperonin complex components. Examination of autophagy markers p62, LC3, and lysosome-associated membrane protein 2 (Lamp2) in cells expressing mutant cyclin F S621G revealed defects in the autophagy pathway specifically resulting in impairment in autophagosomal-lysosome fusion. This finding highlights a potential mechanism by which cyclin F interacts with p62, the receptor responsible for transporting ubiquitylated substrates for autophagic degradation. These findings demonstrate that ALS/FTD-causing mutant cyclin F S621G disrupts Lys48-specific ubiquitylation, leading to accumulation of substrates and defects in the autophagic machinery. This study also demonstrates that a single missense mutation in cyclin F causes hyper-ubiquitylation of proteins that can indirectly impair the autophagy degradation pathway, which is

  19. Microbial Disruption of Autophagy Alters Expression of the RISC Component AGO2, a Critical Regulator of the miRNA Silencing Pathway.

    Science.gov (United States)

    Sibony, Michal; Abdullah, Majd; Greenfield, Laura; Raju, Deepa; Wu, Ted; Rodrigues, David M; Galindo-Mata, Esther; Mascarenhas, Heidi; Philpott, Dana J; Silverberg, Mark S; Jones, Nicola L

    2015-12-01

    Autophagy is implicated in Crohn's disease (CD) pathogenesis. Recent evidence suggests autophagy regulates the microRNA (miRNA)-induced silencing complex (miRISC). Therefore, autophagy may play a novel role in CD by regulating expression of miRISC, thereby altering miRNA silencing. As microbes associated with CD can alter autophagy, we hypothesized that microbial disruption of autophagy affects the critical miRISC component AGO2. AGO2 expression was assessed in epithelial and immune cells, and intestinal organoids with disrupted autophagy. Microarray technology was used to determine the expression of downstream miRNAs in cells with defective autophagy. Increased AGO2 was detected in autophagy-deficient ATG5-/- and ATG16-/- mouse embryonic fibroblast cells (MEFs) in comparison with wild-type MEFs. Chemical agents and VacA toxin, which disrupt autophagy, increased AGO2 expression in MEFs, epithelial cells lines, and human monocytes, respectively. Increased AGO2 was also detected in ATG7-/- intestinal organoids, in comparison with wild-type organoids. Five miRNAs were differentially expressed in autophagy-deficient MEFs. Pathway enrichment analysis of the differentially expressed miRNAs implicated signaling pathways previously associated with CD. Taken together, our results suggest that autophagy is involved in the regulation of the critical miRISC component AGO2 in epithelial and immune cells and primary intestinal epithelial cells. We propose a mechanism by which autophagy alters miRNA expression, which likely impacts the regulation of CD-associated pathways. Furthermore, as enteric microbial products can manipulate autophagy and AGO2, our findings suggest a novel mechanism by which enteric microbes could influence miRNA to promote disease.

  20. Characterization of early autophagy signaling by quantitative phosphoproteomics

    DEFF Research Database (Denmark)

    Rigbolt, Kristoffer Tg; Zarei, Mostafa; Sprenger, Adrian

    2014-01-01

    . To elucidate the regulation of early signaling events upon autophagy induction, we applied quantitative phosphoproteomics characterizing the temporal phosphorylation dynamics after starvation and rapamycin treatment. We obtained a comprehensive atlas of phosphorylation kinetics within the first 30 min upon...... revealing regulated phosphorylation sites on proteins involved in a wide range of cellular processes and an impact of the treatments on the kinome. To approach the potential function of the identified phosphorylation sites we performed a screen for MAP1LC3-interacting proteins and identified a group...... induction of autophagy with both treatments affecting widely different cellular processes. The identification of dynamic phosphorylation already after 2 min demonstrates that the earliest events in autophagy signaling occur rapidly after induction. The data was subjected to extensive bioinformatics analysis...

  1. Mental Imagery in Depression: Phenomenology, Potential Mechanisms, and Treatment Implications.

    Science.gov (United States)

    Holmes, Emily A; Blackwell, Simon E; Burnett Heyes, Stephanie; Renner, Fritz; Raes, Filip

    2016-01-01

    Mental imagery is an experience like perception in the absence of a percept. It is a ubiquitous feature of human cognition, yet it has been relatively neglected in the etiology, maintenance, and treatment of depression. Imagery abnormalities in depression include an excess of intrusive negative mental imagery; impoverished positive imagery; bias for observer perspective imagery; and overgeneral memory, in which specific imagery is lacking. We consider the contribution of imagery dysfunctions to depressive psychopathology and implications for cognitive behavioral interventions. Treatment advances capitalizing on the representational format of imagery (as opposed to its content) are reviewed, including imagery rescripting, positive imagery generation, and memory specificity training. Consideration of mental imagery can contribute to clinical assessment and imagery-focused psychological therapeutic techniques and promote investigation of underlying mechanisms for treatment innovation. Research into mental imagery in depression is at an early stage. Work that bridges clinical psychology and neuroscience in the investigation of imagery-related mechanisms is recommended.

  2. Potential Clinical Implications of the Urotensin II Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Emilie Kane

    2011-07-01

    Full Text Available Urotensin-II (UII, which binds to its receptor UT, plays an important role in the heart, kidneys, pancreas, adrenal gland and CNS. In the vasculature, it acts as a potent endothelium-independent vasoconstrictor and endothelium-dependent vasodilator. In disease states, this constriction-dilation equilibrium is disrupted. There is an upregulation of the UII system in heart disease, metabolic syndrome and kidney failure. The increase in UII release and UT expression suggest that UII system may be implicated in the pathology and pathogenesis of these diseases by causing an increase in ACAT-1 activity leading to SMC proliferation and foam cell infiltration, insulin resistance (DMII, as well as inflammation, high blood pressure and plaque formation. Recently, UT antagonists such as SB-611812, palosuran, and most recently a piperazino-isoindolinone based antagonist have been developed in the hope of better understanding the UII system and treating its associated diseases.

  3. Autophagy in human embryonic stem cells

    NARCIS (Netherlands)

    Tra, Thien; Gong, Lan; Kao, Lin-Pin; Li, Xue-Lei; Grandela, Catarina; Devenish, Rodney J.; Wolvetang, Ernst; Prescott, Mark

    2011-01-01

    Autophagy (macroautophagy) is a degradative process that involves the sequestration of cytosolic material including organelles into double membrane vesicles termed autophagosomes for delivery to the lysosome. Autophagy is essential for preimplantation development of mouse embryos and cavitation of

  4. Reassessing Wind Potential Estimates for India: Economic and Policy Implications

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Amol; Bharvirkar, Ranjit; Khangura, Jagmeet

    2011-09-15

    We assess developable on-shore wind potential in India at three different hub-heights and under two sensitivity scenarios – one with no farmland included, the other with all farmland included. Under the “no farmland included” case, the total wind potential in India ranges from 748 GW at 80m hub-height to 976 GW at 120m hub-height. Under the “all farmland included” case, the potential with a minimum capacity factor of 20 percent ranges from 984 GW to 1,549 GW. High quality wind energy sites, at 80m hub-height with a minimum capacity factor of 25 percent, have a potential between 253 GW (no farmland included) and 306 GW (all farmland included). Our estimates are more than 15 times the current official estimate of wind energy potential in India (estimated at 50m hub height) and are about one tenth of the official estimate of the wind energy potential in the US.

  5. Eccentricity samples: Implications on the potential and the velocity distribution

    Directory of Open Access Journals (Sweden)

    Cubarsi R.

    2017-01-01

    Full Text Available Planar and vertical epicycle frequencies and local angular velocity are related to the derivatives up to the second order of the local potential and can be used to test the shape of the potential from stellar disc samples. These samples show a more complex velocity distribution than halo stars and should provide a more realistic test. We assume an axisymmetric potential allowing a mixture of independent ellipsoidal velocity distributions, of separable or Staeckel form in cylindrical or spherical coordinates. We prove that values of local constants are not consistent with a potential separable in addition in cylindrical coordinates and with a spherically symmetric potential. The simplest potential that fits the local constants is used to show that the harmonical and non-harmonical terms of the potential are equally important. The same analysis is used to estimate the local constants. Two families of nested subsamples selected for decreasing planar and vertical eccentricities are used to borne out the relation between the mean squared planar and vertical eccentricities and the velocity dispersions of the subsamples. According to the first-order epicycle model, the radial and vertical velocity components provide accurate information on the planar and vertical epicycle frequencies. However, it is impossible to account for the asymmetric drift which introduces a systematic bias in estimation of the third constant. Under a more general model, when the asymmetric drift is taken into account, the rotation velocity dispersions together with their asymmetric drift provide the correct fit for the local angular velocity. The consistency of the results shows that this new method based on the distribution of eccentricities is worth using for kinematic stellar samples. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. No 176011: Dynamics and Kinematics of Celestial Bodies and Systems

  6. Exocyst and autophagy-related membrane trafficking in plants.

    Science.gov (United States)

    Pecenková, Tamara; Markovic, Vedrana; Sabol, Peter; Kulich, Ivan; Žárský, Viktor

    2017-12-18

    Endomembrane traffic in eukaryotic cells functions partially as a means of communication; delivery of membrane in one direction has to be balanced with a reduction at the other end. This effect is typically the case during the defence against pathogens. To combat pathogens, cellular growth and differentiation are suppressed, while endomembrane traffic is poised towards limiting the pathogen attack. The octameric exocyst vesicle-tethering complex was originally discovered as a factor facilitating vesicle-targeting and vesicle-plasma membrane (PM) fusion during exocytosis prior to and possibly during SNARE complex formation. Interestingly, it was recently implicated both in animals and plants in autophagy membrane traffic. In animal cells, the exocyst is integrated into the mTOR-regulated energy metabolism stress/starvation pathway, participating in the formation and especially initiation of an autophagosome. In plants, the first functional link was to autophagy-related anthocyanin import to the vacuole and to starvation. In this concise review, we summarize the current knowledge of exocyst functions in autophagy and defence in plants that might involve unconventional secretion and compare it with animal conditions. Formation of different exocyst complexes during undisturbed cell growth, as opposed to periods of cellular stress reactions involving autophagy, might contribute to the coordination of endomembrane trafficking pathways. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Saturation wind power potential and its implications for wind energy.

    Science.gov (United States)

    Jacobson, Mark Z; Archer, Cristina L

    2012-09-25

    Wind turbines convert kinetic to electrical energy, which returns to the atmosphere as heat to regenerate some potential and kinetic energy. As the number of wind turbines increases over large geographic regions, power extraction first increases linearly, but then converges to a saturation potential not identified previously from physical principles or turbine properties. These saturation potentials are >250 terawatts (TW) at 100 m globally, approximately 80 TW at 100 m over land plus coastal ocean outside Antarctica, and approximately 380 TW at 10 km in the jet streams. Thus, there is no fundamental barrier to obtaining half (approximately 5.75 TW) or several times the world's all-purpose power from wind in a 2030 clean-energy economy.

  8. Regulation of autophagy by amino acids and MTOR-dependent signal transduction.

    Science.gov (United States)

    Meijer, Alfred J; Lorin, Séverine; Blommaart, Edward F; Codogno, Patrice

    2015-10-01

    Amino acids not only participate in intermediary metabolism but also stimulate insulin-mechanistic target of rapamycin (MTOR)-mediated signal transduction which controls the major metabolic pathways. Among these is the pathway of autophagy which takes care of the degradation of long-lived proteins and of the elimination of damaged or functionally redundant organelles. Proper functioning of this process is essential for cell survival. Dysregulation of autophagy has been implicated in the etiology of several pathologies. The history of the studies on the interrelationship between amino acids, MTOR signaling and autophagy is the subject of this review. The mechanisms responsible for the stimulation of MTOR-mediated signaling, and the inhibition of autophagy, by amino acids have been studied intensively in the past but are still not completely clarified. Recent developments in this field are discussed.

  9. The intersection between growth factors, autophagy and ER stress: A new target to treat neurodegenerative diseases?

    Science.gov (United States)

    Garcia-Huerta, Paula; Troncoso-Escudero, Paulina; Jerez, Carolina; Hetz, Claudio; Vidal, Rene L

    2016-10-15

    One of the salient features of most neurodegenerative diseases is the aggregation of specific proteins in the brain. This proteostasis imbalance is proposed as a key event triggering the neurodegenerative cascade. The unfolded protein response (UPR) and autophagy pathways are emerging as critical processes implicated in handling disease-related misfolded proteins. However, in some conditions, perturbations in the buffering capacity of the proteostasis network may be part of the etiology of the disease. Thus, pharmacological or gene therapy strategies to enhance autophagy or UPR responses are becoming an attractive target for disease intervention. Here, we discuss current evidence depicting the complex involvement of autophagy and ER stress in brain diseases. Novel pathways to modulate protein misfolding are discussed including the relation between aging and growth factor signaling. This article is part of a Special Issue entitled SI:Autophagy. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Autophagy: A double-edged sword in Alzheimer's disease

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... This article briefly summarizes seminal discoveries that are shedding new light on the critical and unique roles of autophagy in AD and potential therapeutic ... those of the staff, the journals, various programmes, and Current Science, has changed from 'ias.ernet.in' (or 'academy.ias.ernet.in') to 'ias.ac.in'.

  11. AMDE-1 is a dual function chemical for autophagy activation and inhibition.

    Directory of Open Access Journals (Sweden)

    Min Li

    Full Text Available Autophagy is the process by which cytosolic components and organelles are delivered to the lysosome for degradation. Autophagy plays important roles in cellular homeostasis and disease pathogenesis. Small chemical molecules that can modulate autophagy activity may have pharmacological value for treating diseases. Using a GFP-LC3-based high content screening assay we identified a novel chemical that is able to modulate autophagy at both initiation and degradation levels. This molecule, termed as Autophagy Modulator with Dual Effect-1 (AMDE-1, triggered autophagy in an Atg5-dependent manner, recruiting Atg16 to the pre-autophagosomal site and causing LC3 lipidation. AMDE-1 induced autophagy through the activation of AMPK, which inactivated mTORC1 and activated ULK1. AMDE-1did not affect MAP kinase, JNK or oxidative stress signaling for autophagy induction. Surprisingly, treatment with AMDE-1 resulted in impairment in autophagic flux and inhibition of long-lived protein degradation. This inhibition was correlated with a reduction in lysosomal degradation capacity but not with autophagosome-lysosome fusion. Further analysis indicated that AMDE-1 caused a reduction in lysosome acidity and lysosomal proteolytic activity, suggesting that it suppressed general lysosome function. AMDE-1 thus also impaired endocytosis-mediated EGF receptor degradation. The dual effects of AMDE-1 on autophagy induction and lysosomal degradation suggested that its net effect would likely lead to autophagic stress and lysosome dysfunction, and therefore cell death. Indeed, AMDE-1 triggered necroptosis and was preferentially cytotoxic to cancer cells. In conclusion, this study identified a new class of autophagy modulators with dual effects, which can be explored for potential uses in cancer therapy.

  12. Establishing a milkborne disease outbreak profile: potential food defense implications.

    Science.gov (United States)

    Newkirk, Ryan; Hedberg, Craig; Bender, Jeff

    2011-03-01

    The main objectives of this study were to establish baseline characteristics for milkborne outbreaks, establish an expected milkborne outbreak profile, and identify potential indicators of food terrorism. This study used 1990-2006 data from the Centers for Disease Control and Prevention Annual Listings of Disease Outbreaks and the Foodborne Outbreak Database (FOOD) to establish epidemiologic baseline characteristics for disease outbreaks associated with fluid milk. FOOD data from 2007 were used to qualitatively validate the potential of the baseline characteristics and the expected outbreak profile. Eighty-three fluid milkborne outbreaks were reported between 1990 and 2006, resulting in 3621 illnesses. The mean number of illnesses per outbreak was 43.6 (illness range: 2-1644). Consumption of unpasteurized milk was associated with 55.4% of reported outbreaks. Campylobacter spp., Escherichia coli, and Salmonella spp. caused 51.2%, 10.8%, and 9.6% of reported outbreaks, respectively. Private homes accounted for 41.0% of outbreak locations. Number ill, outbreak location, and etiology were the primary characteristics which could signal a potential intentional contamination event. In 2007, one pasteurized milk outbreak caused by Listeria was flagged as aberrative compared with the expected outbreak profile. The creation and dissemination of expected outbreak profiles and epidemiologic baseline characteristics allow public health and Homeland Security officials to quickly assess the potential of intentional food contamination. A faster public health and medical system response can result in decreased morbidity and mortality.

  13. Tetrandrine induces lipid accumulation through blockade of autophagy in a hepatic stellate cell line

    International Nuclear Information System (INIS)

    Miyamae, Yusaku; Nishito, Yukina; Nakai, Naomi; Nagumo, Yoko; Usui, Takeo; Masuda, Seiji; Kambe, Taiho; Nagao, Masaya

    2016-01-01

    Macroautophagy, or autophagy, is a cellular response in which unnecessary cytoplasmic components, including lipids and organelles, are self-degraded. Recent studies closely related autophagy to activation of hepatic stellate cells (HSCs), a process critical in the pathogenesis of liver fibrosis. During HSC activation, cytoplasmic lipid droplets (LDs) are degraded as autophagic cargo, and then cells express fibrogenic genes. Thus, inhibition of autophagy in HSCs is a potential therapeutic approach for attenuating liver fibrosis. We found that tetrandrine, a bisbenzylisoquinoline alkaloid isolated from Stephania tetrandra, induced lipid accumulation, a phenotype associated with quiescent HSCs, through blockade of autophagy in the rat-derived HSC line HSC-T6. Tetrandrine inhibited autophagic flux without affecting lysosomal function. A phenotypic comparison using siRNA knockdown suggested that tetrandrine may target regulators, involved in fusion between autophagosomes and lysosomes (e.g., syntaxin 17). Moreover, perilipin 1, an LD-coated protein, co-localized specifically with LC3, a marker protein for autophagosomes, in tetrandrine-treated HSC-T6 cells. This suggests a potential role for perilipin 1 in autophagy-mediated LD degradation in HSCs. Our results identified tetrandrine as a potential tool for prevention and treatment of HSC activation. - Highlights: • Autophagy is closely related to lipid degradation in hepatic stellate cells. • Tetrandrine (Tet) causes lipid accumulation via blockade of autophagy in HSC-T6 cells. • Tet blocked autophagy without affecting lysosomal function unlike bafilomycin A_1. • Perilipin 1 was specifically co-localized with LC3 in Tet-treated cells. • Perilipin 1 may play potential roles in autophagy-mediated lipid degradation.

  14. Tetrandrine induces lipid accumulation through blockade of autophagy in a hepatic stellate cell line

    Energy Technology Data Exchange (ETDEWEB)

    Miyamae, Yusaku, E-mail: ymiyamae@lif.kyoto-u.ac.jp [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Nishito, Yukina; Nakai, Naomi [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Nagumo, Yoko; Usui, Takeo [Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Masuda, Seiji; Kambe, Taiho [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Nagao, Masaya, E-mail: mnagao@kais.kyoto-u.ac.jp [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

    2016-08-12

    Macroautophagy, or autophagy, is a cellular response in which unnecessary cytoplasmic components, including lipids and organelles, are self-degraded. Recent studies closely related autophagy to activation of hepatic stellate cells (HSCs), a process critical in the pathogenesis of liver fibrosis. During HSC activation, cytoplasmic lipid droplets (LDs) are degraded as autophagic cargo, and then cells express fibrogenic genes. Thus, inhibition of autophagy in HSCs is a potential therapeutic approach for attenuating liver fibrosis. We found that tetrandrine, a bisbenzylisoquinoline alkaloid isolated from Stephania tetrandra, induced lipid accumulation, a phenotype associated with quiescent HSCs, through blockade of autophagy in the rat-derived HSC line HSC-T6. Tetrandrine inhibited autophagic flux without affecting lysosomal function. A phenotypic comparison using siRNA knockdown suggested that tetrandrine may target regulators, involved in fusion between autophagosomes and lysosomes (e.g., syntaxin 17). Moreover, perilipin 1, an LD-coated protein, co-localized specifically with LC3, a marker protein for autophagosomes, in tetrandrine-treated HSC-T6 cells. This suggests a potential role for perilipin 1 in autophagy-mediated LD degradation in HSCs. Our results identified tetrandrine as a potential tool for prevention and treatment of HSC activation. - Highlights: • Autophagy is closely related to lipid degradation in hepatic stellate cells. • Tetrandrine (Tet) causes lipid accumulation via blockade of autophagy in HSC-T6 cells. • Tet blocked autophagy without affecting lysosomal function unlike bafilomycin A{sub 1}. • Perilipin 1 was specifically co-localized with LC3 in Tet-treated cells. • Perilipin 1 may play potential roles in autophagy-mediated lipid degradation.

  15. Listeria Occurrence in Poultry Flocks: Detection and Potential Implications

    Directory of Open Access Journals (Sweden)

    Michael J. Rothrock

    2017-08-01

    Full Text Available Foodborne pathogens such as Salmonella, Campylobacter, Escherichia coli, and Listeria are a major concern within the food industry due to their pathogenic potential to cause infection. Of these, Listeria monocytogenes, possesses a high mortality rate (approximately 20% and is considered one of the most dangerous foodborne pathogens. Although the usual reservoirs for Listeria transmission have been extensively studied, little is known about the relationship between Listeria and live poultry production. Sporadic and isolated cases of listeriosis have been attributed to poultry production and Listeria spp. have been isolated from all stages of poultry production and processing. Farm studies suggest that live birds may be an important vector and contributor to contamination of the processing environment and transmission of Listeria to consumers. Therefore, the purpose of this review is to highlight the occurrence, incidence, and potential systemic interactions of Listeria spp. with poultry.

  16. Listeria Occurrence in Poultry Flocks: Detection and Potential Implications.

    Science.gov (United States)

    Rothrock, Michael J; Davis, Morgan L; Locatelli, Aude; Bodie, Aaron; McIntosh, Tori G; Donaldson, Janet R; Ricke, Steven C

    2017-01-01

    Foodborne pathogens such as Salmonella, Campylobacter, Escherichia coli , and Listeria are a major concern within the food industry due to their pathogenic potential to cause infection. Of these, Listeria monocytogenes , possesses a high mortality rate (approximately 20%) and is considered one of the most dangerous foodborne pathogens. Although the usual reservoirs for Listeria transmission have been extensively studied, little is known about the relationship between Listeria and live poultry production. Sporadic and isolated cases of listeriosis have been attributed to poultry production and Listeria spp. have been isolated from all stages of poultry production and processing. Farm studies suggest that live birds may be an important vector and contributor to contamination of the processing environment and transmission of Listeria to consumers. Therefore, the purpose of this review is to highlight the occurrence, incidence, and potential systemic interactions of Listeria spp. with poultry.

  17. Shock Wave Therapy Promotes Cardiomyocyte Autophagy and Survival during Hypoxia

    Directory of Open Access Journals (Sweden)

    Ling Du

    2017-06-01

    Full Text Available Background: Autophagy plays an important role in cardiovascular disease. Controversy still exists regarding the effect of autophagy on ischemic/hypoxic myocardium. Cardiac shock wave therapy (CSWT is an effective alternative treatment for refractory ischemic heart disease. Whether CSWT can regulate cardiomyocyte autophagy under hypoxic conditions is not clear. We established a myocardial hypoxia model using the H9c2 cell line and performed shock waves (SWs treatment to evaluate the effect of SW on autophagy. Methods: The H9c2 cells were incubated under hypoxic conditions, and SW treatment was then performed at energies of 0.02, 0.05, or 0.10 mJ/mm2. The cell viability and intracellular ATP level were examined. Western blot analysis was used to assess the expression of LC3B, AMPK, mTOR, Beclin-1, Sirt1, and HIF-1α. Autophagic vacuoles were visualized by monodansylcadaverine staining. Results: After the 24-hour hypoxic period, cardiomyocyte viability and ATP levels were decreased and autophagy was significantly increased in H9c2 cells. SW treatment with an energy of 0.05 mJ/mm2 significantly increased the cellular viability, ATP level, LC3B-II/I, and number of autophagic vacuoles. In addition, phosphorylated AMPK and Sirt1 were increased and phosphorylated mTOR and HIF-1α were decreased after SW treatment. Conclusion: SW treatment can potentially promote cardiomyocyte autophagy during hypoxia and protect cardiomyocyte function by regulating the AMPK/mTOR pathway.

  18. EGFR overexpressing cells and tumors are dependent on autophagy for growth and survival

    International Nuclear Information System (INIS)

    Jutten, Barry; Keulers, Tom G.; Schaaf, Marco B.E.; Savelkouls, Kim; Theys, Jan; Span, Paul N.; Vooijs, Marc A.; Bussink, Johan; Rouschop, Kasper M.A.

    2013-01-01

    Background and purpose: The epidermal growth factor receptor (EGFR) is overexpressed, amplified or mutated in various human epithelial tumors, and is associated with tumor aggressiveness and therapy resistance. Autophagy activation provides a survival advantage for cells in the tumor microenvironment. In the current study, we assessed the potential of autophagy inhibition (using chloroquine (CQ)) in treatment of EGFR expressing tumors. Material and methods: Quantitative PCR, immunohistochemistry, clonogenic survival, proliferation assays and in vivo tumor growth were used to assess this potential. Results: We show that EGFR overexpressing xenografts are sensitive to CQ treatment and are sensitized to irradiation by autophagy inhibition. In HNSSC xenografts, a correlation between EGFR and expression of the autophagy marker LC3b is observed, suggesting a role for autophagy in EGFR expressing tumors. This observation was substantiated in cell lines, showing high EGFR expressing cells to be more sensitive to CQ addition as reflected by decreased proliferation and survival. Surprisingly high EGFR expressing cells display a lower autophagic flux. Conclusions: The EGFR high expressing cells and tumors investigated in this study are highly dependent on autophagy for growth and survival. Inhibition of autophagy may therefore provide a novel treatment opportunity for EGFR overexpressing tumors

  19. Implication of Heat Shock Factors in Tumorigenesis: Therapeutical Potential

    International Nuclear Information System (INIS)

    Thonel, Aurelie de; Mezger, Valerie; Garrido, Carmen

    2011-01-01

    Heat Shock Factors (HSF) form a family of transcription factors (four in mammals) which were named according to the discovery of their activation by a heat shock. HSFs trigger the expression of genes encoding Heat Shock Proteins (HSPs) that function as molecular chaperones, contributing to establish a cytoprotective state to various proteotoxic stresses and in pathological conditions. Increasing evidence indicates that this ancient transcriptional protective program acts genome-widely and performs unexpected functions in the absence of experimentally defined stress. Indeed, HSFs are able to re-shape cellular pathways controlling longevity, growth, metabolism and development. The most well studied HSF, HSF1, has been found at elevated levels in tumors with high metastatic potential and is associated with poor prognosis. This is partly explained by the above-mentioned cytoprotective (HSP-dependent) function that may enable cancer cells to adapt to the initial oncogenic stress and to support malignant transformation. Nevertheless, HSF1 operates as major multifaceted enhancers of tumorigenesis through, not only the induction of classical heat shock genes, but also of “non-classical” targets. Indeed, in cancer cells, HSF1 regulates genes involved in core cellular functions including proliferation, survival, migration, protein synthesis, signal transduction, and glucose metabolism, making HSF1 a very attractive target in cancer therapy. In this review, we describe the different physiological roles of HSFs as well as the recent discoveries in term of non-cogenic potential of these HSFs, more specifically associated to the activation of “non-classical” HSF target genes. We also present an update on the compounds with potent HSF1-modulating activity of potential interest as anti-cancer therapeutic agents

  20. Implication of Heat Shock Factors in Tumorigenesis: Therapeutical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Thonel, Aurelie de [INSERM U866, Dijon (France); Faculty of Medicine and Pharmacy, University of Burgundy, 21033 Dijon (France); Mezger, Valerie, E-mail: valerie.mezger@univ-paris-diderot.fr [CNRS, UMR7216 Epigenetics and Cell Fate, Paris (France); University Paris Diderot, 75013 Paris (France); Garrido, Carmen, E-mail: valerie.mezger@univ-paris-diderot.fr [INSERM U866, Dijon (France); Faculty of Medicine and Pharmacy, University of Burgundy, 21033 Dijon (France); CHU, Dijon BP1542, Dijon (France)

    2011-03-07

    Heat Shock Factors (HSF) form a family of transcription factors (four in mammals) which were named according to the discovery of their activation by a heat shock. HSFs trigger the expression of genes encoding Heat Shock Proteins (HSPs) that function as molecular chaperones, contributing to establish a cytoprotective state to various proteotoxic stresses and in pathological conditions. Increasing evidence indicates that this ancient transcriptional protective program acts genome-widely and performs unexpected functions in the absence of experimentally defined stress. Indeed, HSFs are able to re-shape cellular pathways controlling longevity, growth, metabolism and development. The most well studied HSF, HSF1, has been found at elevated levels in tumors with high metastatic potential and is associated with poor prognosis. This is partly explained by the above-mentioned cytoprotective (HSP-dependent) function that may enable cancer cells to adapt to the initial oncogenic stress and to support malignant transformation. Nevertheless, HSF1 operates as major multifaceted enhancers of tumorigenesis through, not only the induction of classical heat shock genes, but also of “non-classical” targets. Indeed, in cancer cells, HSF1 regulates genes involved in core cellular functions including proliferation, survival, migration, protein synthesis, signal transduction, and glucose metabolism, making HSF1 a very attractive target in cancer therapy. In this review, we describe the different physiological roles of HSFs as well as the recent discoveries in term of non-cogenic potential of these HSFs, more specifically associated to the activation of “non-classical” HSF target genes. We also present an update on the compounds with potent HSF1-modulating activity of potential interest as anti-cancer therapeutic agents.

  1. Autophagy plays a critical role in ChLym-1-induced cytotoxicity of non-hodgkin's lymphoma cells.

    Directory of Open Access Journals (Sweden)

    Jiajun Fan

    Full Text Available Autophagy is a critical mechanism in both cancer therapy resistance and tumor suppression. Monoclonal antibodies have been documented to kill tumor cells via apoptosis, antibody-dependent cellular cytotoxicity (ADCC and complement-dependent cytotoxicity (CDC. In this study, we report for the first time that chLym-1, a chimeric anti-human HLA-DR monoclonal antibody, induces autophagy in Raji Non-Hodgkin's Lymphoma (NHL cells. Interestingly, inhibition of autophagy by pharmacological inhibitors (3-methyladenine and NH4Cl or genetic approaches (siRNA targeting Atg5 suppresses chLym-1-induced growth inhibition, apoptosis, ADCC and CDC in Raji cells, while induction of autophagy could accelerate cytotoxic effects of chLym-1 on Raji cells. Furthermore, chLym-1-induced autophagy can mediate apoptosis through Caspase 9 activation, demonstrating the tumor-suppressing role of autophagy in antilymphoma effects of chLym-1. Moreover, chLym-1 can activate several upstream signaling pathways of autophagy including Akt/mTOR and extracellular signal-regulated kinase 1/2 (Erk1/2. These results elucidate the critical role of autophagy in cytotoxicity of chLym-1 antibody and suggest a potential therapeutic strategy of NHL therapy by monoclonal antibody chLym-1 in combination with autophagy inducer.

  2. Effects of ambroxol on the autophagy-lysosome pathway and mitochondria in primary cortical neurons.

    Science.gov (United States)

    Magalhaes, J; Gegg, M E; Migdalska-Richards, A; Schapira, A H

    2018-01-23

    Glucocerebrosidase (GBA1) mutations are the major genetic risk factor for Parkinson's Disease (PD). The pathogenic mechanism is still unclear, but alterations in lysosomal-autophagy processes are implicated due to reduction of mutated glucocerebrosidase (GCase) in lysosomes. Wild-type GCase activity is also decreased in sporadic PD brains. Small molecule chaperones that increase lysosomal GCase activity have potential to be disease-modifying therapies for GBA1-associated and sporadic PD. Therefore we have used mouse cortical neurons to explore the effects of the chaperone ambroxol. This chaperone increased wild-type GCase mRNA, protein levels and activity, as well as increasing other lysosomal enzymes and LIMP2, the GCase transporter. Transcription factor EB (TFEB), the master regulator of the CLEAR pathway involved in lysosomal biogenesis was also increased upon ambroxol treatment. Moreover, we found macroautophagy flux blocked and exocytosis increased in neurons treated with ambroxol. We suggest that ambroxol is blocking autophagy and driving cargo towards the secretory pathway. Mitochondria content was also found to be increased by ambroxol via peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α). Our data suggest that ambroxol, besides being a GCase chaperone, also acts on other pathways, such as mitochondria, lysosomal biogenesis, and the secretory pathway.

  3. Recent decrease in typhoon destructive potential and global warming implications

    Science.gov (United States)

    Lin, I-I; Chan, Johnny C.L.

    2015-01-01

    Typhoons (tropical cyclones) severely impact the half-billion population of the Asian Pacific. Intriguingly, during the recent decade, typhoon destructive potential (Power Dissipation Index, PDI) has decreased considerably (by ∼35%). This decrease, paradoxically, has occurred despite the increase in typhoon intensity and ocean warming. Using the method proposed by Emanuel (in 2007), we show that the stronger negative contributions from typhoon frequency and duration, decrease to cancel the positive contribution from the increasing intensity, controlling the PDI. Examining the typhoons' environmental conditions, we find that although the ocean condition became more favourable (warming) in the recent decade, the atmospheric condition ‘worsened' at the same time. The ‘worsened' atmospheric condition appears to effectively overpower the ‘better' ocean conditions to suppress PDI. This stronger negative contribution from reduced typhoon frequency over the increased intensity is also present under the global warming scenario, based on analysis of the simulated typhoon data from high-resolution modelling. PMID:25990561

  4. The human gut microbiota and virome: Potential therapeutic implications.

    Science.gov (United States)

    Scarpellini, Emidio; Ianiro, Gianluca; Attili, Fabia; Bassanelli, Chiara; De Santis, Adriano; Gasbarrini, Antonio

    2015-12-01

    Human gut microbiota is a complex ecosystem with several functions integrated in the host organism (metabolic, immune, nutrients absorption, etc.). Human microbiota is composed by bacteria, yeasts, fungi and, last but not least, viruses, whose composition has not been completely described. According to previous evidence on pathogenic viruses, the human gut harbours plant-derived viruses, giant viruses and, only recently, abundant bacteriophages. New metagenomic methods have allowed to reconstitute entire viral genomes from the genetic material spread in the human gut, opening new perspectives on the understanding of the gut virome composition, the importance of gut microbiome, and potential clinical applications. This review reports the latest evidence on human gut "virome" composition and its function, possible future therapeutic applications in human health in the context of the gut microbiota, and attempts to clarify the role of the gut "virome" in the larger microbial ecosystem. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  5. Configuration and technology implications of potential nuclear hydrogen system applications.

    Energy Technology Data Exchange (ETDEWEB)

    Conzelmann, G.; Petri, M.; Forsberg, C.; Yildiz, B.; ORNL

    2005-11-05

    Nuclear technologies have important distinctions and potential advantages for large-scale generation of hydrogen for U.S. energy services. Nuclear hydrogen requires no imported fossil fuels, results in lower greenhouse-gas emissions and other pollutants, lends itself to large-scale production, and is sustainable. The technical uncertainties in nuclear hydrogen processes and the reactor technologies needed to enable these processes, as well waste, proliferation, and economic issues must be successfully addressed before nuclear energy can be a major contributor to the nation's energy future. In order to address technical issues in the time frame needed to provide optimized hydrogen production choices, the Nuclear Hydrogen Initiative (NHI) must examine a wide range of new technologies, make the best use of research funding, and make early decisions on which technology options to pursue. For these reasons, it is important that system integration studies be performed to help guide the decisions made in the NHI. In framing the scope of system integration analyses, there is a hierarchy of questions that should be addressed: What hydrogen markets will exist and what are their characteristics? Which markets are most consistent with nuclear hydrogen? What nuclear power and production process configurations are optimal? What requirements are placed on the nuclear hydrogen system? The intent of the NHI system studies is to gain a better understanding of nuclear power's potential role in a hydrogen economy and what hydrogen production technologies show the most promise. This work couples with system studies sponsored by DOE-EE and other agencies that provide a basis for evaluating and selecting future hydrogen production technologies. This assessment includes identifying commercial hydrogen applications and their requirements, comparing the characteristics of nuclear hydrogen systems to those market requirements, evaluating nuclear hydrogen configuration options

  6. CAROTID BODY POTENTIATION DURING CHRONIC INTERMITTENT HYPOXIA: IMPLICATION FOR HYPERTENSION

    Directory of Open Access Journals (Sweden)

    Rodrigo eDel Rio

    2014-11-01

    Full Text Available Autonomic dysfunction is involved in the development of hypertension in humans with obstructive sleep apnea, and animals exposed to chronic intermittent hypoxia (CIH. It has been proposed that a crucial step in the development of the hypertension is the potentiation of the carotid body (CB chemosensory responses to hypoxia, but the temporal progression of the CB chemosensory, autonomic and hypertensive changes induced by CIH are not known. We tested the hypothesis that CB potentiation precedes the autonomic imbalance and the hypertension in rats exposed to CIH. Thus, we studied the changes in CB chemosensory and ventilatory responsiveness to hypoxia, the spontaneous baroreflex sensitivity (BRS, heart rate variability (HRV and arterial blood pressure in pentobarbital anesthetized rats exposed to CIH for 7, 14 and 21 days. After 7 days of CIH, CB chemosensory and ventilatory responses to hypoxia were enhanced, while BRS was significantly reduced by 2-fold in CIH-rats compared to sham-rats. These alterations persisted until 21 days of CIH. After 14 days, CIH shifted the HRV power spectra suggesting a predominance of sympathetic over parasympathetic tone. In contrast, hypertension was found after 21 days of CIH. Concomitant changes between the gain of spectral HRV, BRS and ventilatory hypoxic chemoreflex showed that the CIH-induced BRS attenuation preceded the HRV changes. CIH induced a simultaneous decrease of the BRS gain along with an increase of the hypoxic ventilatory gain. Present results show that CIH-induced persistent hypertension was preceded by early changes in CB chemosensory control of cardiorespiratory and autonomic function.

  7. Potentials and policy implications of energy and material efficiency improvement

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Levine, Mark; Price, Lynn; Martin, Nathan; van den Broek, Richard; Block, Kornelis

    1997-01-01

    There is a growing awareness of the serious problems associated with the provision of sufficient energy to meet human needs and to fuel economic growth world-wide. This has pointed to the need for energy and material efficiency, which would reduce air, water and thermal pollution, as well as waste production. Increasing energy and material efficiency also have the benefits of increased employment, improved balance of imports and exports, increased security of energy supply, and adopting environmentally advantageous energy supply. A large potential exists for energy savings through energy and material efficiency improvements. Technologies are not now, nor will they be, in the foreseeable future, the limiting factors with regard to continuing energy efficiency improvements. There are serious barriers to energy efficiency improvement, including unwillingness to invest, lack of available and accessible information, economic disincentives and organizational barriers. A wide range of policy instruments, as well as innovative approaches have been tried in some countries in order to achieve the desired energy efficiency approaches. These include: regulation and guidelines; economic instruments and incentives; voluntary agreements and actions, information, education and training; and research, development and demonstration. An area that requires particular attention is that of improved international co-operation to develop policy instruments and technologies to meet the needs of developing countries. Material efficiency has not received the attention that it deserves. Consequently, there is a dearth of data on the qualities and quantities for final consumption, thus, making it difficult to formulate policies. Available data, however, suggest that there is a large potential for improved use of many materials in industrialized countries.

  8. Assessment of Autophagy in Neurons and Brain Tissue

    Science.gov (United States)

    Benito-Cuesta, Irene; Diez, Héctor; Ordoñez, Lara; Wandosell, Francisco

    2017-01-01

    Autophagy is a complex process that controls the transport of cytoplasmic components into lysosomes for degradation. This highly conserved proteolytic system involves dynamic and complex processes, using similar molecular elements and machinery from yeast to humans. Moreover, autophagic dysfunction may contribute to a broad spectrum of mammalian diseases. Indeed, in adult tissues, where the capacity for regeneration or cell division is low or absent (e.g., in the mammalian brain), the accumulation of proteins/peptides that would otherwise be recycled or destroyed may have pathological implications. Indeed, such changes are hallmarks of pathologies, like Alzheimer’s, Prion or Parkinson’s disease, known as proteinopathies. However, it is still unclear whether such dysfunction is a cause or an effect in these conditions. One advantage when analysing autophagy in the mammalian brain is that almost all the markers described in different cell lineages and systems appear to be present in the brain, and even in neurons. By contrast, the mixture of cell types present in the brain and the differentiation stage of such neurons, when compared with neurons in culture, make translating basic research to the clinic less straightforward. Thus, the purpose of this review is to describe and discuss the methods available to monitor autophagy in neurons and in the mammalian brain, a process that is not yet fully understood, focusing primarily on mammalian macroautophagy. We will describe some general features of neuronal autophagy that point to our focus on neuropathologies in which macroautophagy may be altered. Indeed, we centre this review around the hypothesis that enhanced autophagy may be able to provide therapeutic benefits in some brain pathologies, like Alzheimer’s disease, considering this pathology as one of the most prevalent proteinopathies. PMID:28832529

  9. Ordered bulk degradation via autophagy

    DEFF Research Database (Denmark)

    Dengjel, Jörn; Kristensen, Anders Riis; Andersen, Jens S

    2008-01-01

    During amino acid starvation, cells undergo macroautophagy which is regarded as an unspecific bulk degradation process. Lately, more and more organelle-specific autophagy subtypes such as reticulophagy, mitophagy and ribophagy have been described and it could be shown, depending on the experimental...... at proteasomal and lysosomal degradation ample cross-talk between the two degradation pathways became evident. Degradation via autophagy appeared to be ordered and regulated at the protein complex/organelle level. This raises several important questions such as: can macroautophagy itself be specific and what...

  10. Modulation of pathogen recognition by autophagy

    Directory of Open Access Journals (Sweden)

    Ji Eun eOh

    2012-03-01

    Full Text Available Autophagy is an ancient biological process for maintaining cellular homeostasis by degradation of long-lived cytosolic proteins and organelles. Recent studies demonstrated that autophagy is availed by immune cells to regulate innate immunity. On the one hand, cells exert direct effector function by degrading intracellular pathogens; on the other hand, autophagy modulates pathogen recognition and downstream signaling for innate immune responses. Pathogen recognition via pattern recognition receptors induces autophagy. The function of phagocytic cells is enhanced by recruitment of autophagy-related proteins. Moreover, autophagy acts as a delivery system for viral replication complexes to migrate to the endosomal compartments where virus sensing occurs. In another case, key molecules of the autophagic pathway have been found to negatively regulate immune signaling, thus preventing aberrant activation of cytokine production and consequent immune responses. In this review, we focus on the recent advances in the role of autophagy in pathogen recognition and modulation of innate immune responses.

  11. Intermolecular potential for Ar + D2O from differential scattering cross sections, and its implications for the water pair potential

    International Nuclear Information System (INIS)

    Brooks, R.; Porter, R.A.R.; Kalos, F.; Grosser, A.E.

    1975-01-01

    A velocity selected molecular beam of D 2 O was crossed with a nozzle beam of Ar and the angular distribution of the scattered D 2 O was measured mass spectrometrically. By varying the velocity of the D 2 O beam, the differential cross section was measured at two collision energies. The experimental results were compared with synthetic differential cross sections calculated from Lennard-Jones and Kihara-Stockmayer trial potentials to determine potential parameters. Implications for the H 2 O pair potential are discussed

  12. Potential implications of the helical heart in congenital heart defects.

    Science.gov (United States)

    Corno, Antonio F; Kocica, Mladen J

    2007-01-01

    The anatomic and functional observations made by Francisco Torrent-Guasp, in particular his discovery of the helical ventricular myocardial band (HVMB), have challenged what has been taught to cardiologists and cardiac surgeons over centuries. A literature debate is ongoing, with interdependent articles and comments from supporters and critics. Adequate understanding of heart structure and function is obviously indispensable for the decision-making process in congenital heart defects. The HVMB described by Torrent-Guasp and the potential impact on the understanding and treatment of congenital heart defects has been analyzed in the following settings: embryology, ventriculo-arterial discordance (transposition of great arteries), Ebstein's anomaly, pulmonary valve regurgitation after repair of tetralogy of Fallot, Ross operation, and other congenital heart defects. The common structural spiral feature is only one of the elements responsible for the functional interaction of right and left ventricles, and understanding the form/function relationship in congenital heart defects is more difficult than for acquired heart disease because of the variety and complexity of congenital heart defects. Individuals involved in the care of patients with congenital heart defects have to be stimulated to consider further investigations and alternative surgical strategies.

  13. Cisplatin induces protective autophagy through activation of BECN1 in human bladder cancer cells.

    Science.gov (United States)

    Lin, Ji-Fan; Lin, Yi-Chia; Tsai, Te-Fu; Chen, Hung-En; Chou, Kuang-Yu; Hwang, Thomas I-Sheng

    2017-01-01

    indicated that cisplatin-induced autophagy is mediated by BECN1 in BC cells. Therefore, combinative treatment using cisplatin and autophagy inhibitors could potentially overcome cisplatin resistance related to autophagy induction.

  14. Gender differences in susceptibility to schizophrenia: Potential implication of neurosteroids.

    Science.gov (United States)

    Huang, Yu-Chi; Hung, Chi-Fa; Lin, Pao-Yen; Lee, Yu; Wu, Chih-Ching; Hsu, Su-Ting; Chen, Chien-Chih; Chong, Mian-Yoon; Lin, Chieh-Hsin; Wang, Liang-Jen

    2017-10-01

    Past research has indicated gender differences in the clinical characteristics and course of schizophrenia. In this study, we investigated whether gender differences in the manifestation of schizophrenia are correlated with neurosteroids, including dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and pregnenolone. We further explored the potential relationship between the aforementioned neurosteroids and psychopathology. We recruited 65 schizophrenic patients (36 males and 29 females) and 103 healthy control subjects (47 males and 56 females) and obtained blood samples from the subjects in the morning while in a fasting state to determine the serum levels of DHEA, DHEA-S, and pregnenolone. The psychopathology and mood symptoms of patients with schizophrenia were evaluated using the Positive and Negative Syndrome Scale (PANSS) and 17-item Hamilton Depression Rating Scale, respectively. Compared to the male control subjects, male patients with schizophrenia had significantly lower serum levels of DHEA and pregnenolone. In males with schizophrenia, the serum levels of DHEA and DHEA-S were associated with the age of onset and the duration of illness, while pregnenolone levels were associated with general symptoms of the PANSS. However, none of the neurosteroid levels were different between the female patients with schizophrenia and the female controls, and no significant correlation between neurosteroid levels and psychopathology evaluations was found among the schizophrenic females. Neurosteroids, including DHEA, DHEA-S, and pregnenolone, are involved in the pathophysiology of schizophrenia in male patients, but not in female ones. Therefore, our findings suggest that neurosteroids may be associated with gender differences in susceptibility to schizophrenia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Autophagy postpones apoptotic cell death in PRRSV infection through Bad-Beclin1 interaction.

    Science.gov (United States)

    Zhou, Ao; Li, Shuaifeng; Khan, Faheem Ahmed; Zhang, Shujun

    2016-01-01

    Autophagy and apoptosis play significant roles in PRRSV infection and replication. However, the interaction between these 2 processes in PRRSV replication is still far from been completely understood. In our studies, the exposure of MARC-145 cells to PRRSV confirmed the activation of autophagy and subsequent induction of apoptosis. The inhibition of autophagy by 3-methyladenine (3-MA) caused a significant increase in PRRSV-induced apoptosis, showing a potential connection between both mechanisms. Moreover, we observed an increase in Bad expression (a pro-apoptotic protein) and Beclin1 (an autophagy regulator) in virus-infected cells up to 36h. Co-immunoprecipitation assays showed the formation of Bad and Beclin1 complex in PRRSV infected cells. Accordingly, Bad co-localized with Beclin1 in MARC-145 infected cells. Knockdown of Beclin1 significantly decreased PRRSV replication and PRRSV-induced autophagy, while Bad silencing resulted in increased autophagy and enhanced viral replication. Furthermore, PRRSV infection phosphorylated Bad (Ser112) to promote cellular survival. These results demonstrate that autophagy can favor PRRSV replication by postponing apoptosis through the formation of a Bad-Beclin1 complex.

  16. Kaempferol induces hepatocellular carcinoma cell death via endoplasmic reticulum stress-CHOP-autophagy signaling pathway.

    Science.gov (United States)

    Guo, Haiqing; Lin, Wei; Zhang, Xiangying; Zhang, Xiaohui; Hu, Zhongjie; Li, Liying; Duan, Zhongping; Zhang, Jing; Ren, Feng

    2017-10-10

    Kaempferol is a flavonoid compound that has gained widespread attention due to its antitumor functions. However, the underlying mechanisms are still not clear. The present study investigated the effect of kaempferol on hepatocellular carcinoma and its underlying mechanisms. Kaempferol induced autophagy in a concentration- and time-dependent manner in HepG2 or Huh7 cells, which was evidenced by the significant increase of autophagy-related genes. Inhibition of autophagy pathway, through 3-methyladenine or Atg7 siRNA, strongly diminished kaempferol-induced apoptosis. We further hypothesized that kaempferol can induce autophagy via endoplasmic reticulum (ER) stress pathway. Indeed, blocking ER stress by 4-phenyl butyric acid (4-PBA) or knockdown of CCAAT/enhancer-binding protein homologous protein (CHOP) with siRNA alleviated kaempferol-induced HepG2 or Huh7 cells autophagy; while transfection with plasmid overexpressing CHOP reversed the effect of 4-PBA on kaempferol-induced autophagy. Our results demonstrated that kaempferol induced hepatocarcinoma cell death via ER stress and CHOP-autophagy signaling pathway; kaempferol may be used as a potential chemopreventive agent for patients with hepatocellular carcinoma.

  17. Suberoylanilide hydroxamic acid sensitizes neuroblastoma to paclitaxel by inhibiting thioredoxin-related protein 14-mediated autophagy.

    Science.gov (United States)

    Zhen, Zijun; Yang, Kaibin; Ye, Litong; You, Zhiyao; Chen, Rirong; Liu, Ying; He, Youjian

    2017-07-01

    Paclitaxel is not as effective for neuroblastoma as most of the front-line chemotherapeutics due to drug resistance. This study explored the regulatory mechanism of paclitaxel-associated autophagy and potential solutions to paclitaxel resistance in neuroblastoma. The formation of autophagic vesicles was detected by scanning transmission electron microscopy and flow cytometry. The autophagy-associated proteins were assessed by western blot. Autophagy was induced and the autophagy-associated proteins LC3-I, LC3-II, Beclin 1, and thioredoxin-related protein 14 (TRP14), were found to be upregulated in neuroblastoma cells that were exposed to paclitaxel. The inhibition of Beclin 1 or TRP14 by siRNA increased the sensitivity of the tumor cells to paclitaxel. In addition, Beclin 1-mediated autophagy was regulated by TRP14. Furthermore, the TRP14 inhibitor suberoylanilide hydroxamic acid (SAHA) downregulated paclitaxel-induced autophagy and enhanced the anticancer effects of paclitaxel in normal control cancer cells but not in cells with upregulated Beclin 1 and TRP14 expression. Our findings showed that paclitaxel-induced autophagy in neuroblastoma cells was regulated by TRP14 and that SAHA could sensitize neuroblastoma cells to paclitaxel by specifically inhibiting TRP14. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  18. Rhynchophylla total alkaloid rescues autophagy, decreases oxidative stress and improves endothelial vasodilation in spontaneous hypertensive rats.

    Science.gov (United States)

    Li, Chao; Jiang, Feng; Li, Yun-Lun; Jiang, Yue-Hua; Yang, Wen-Qing; Sheng, Jie; Xu, Wen-Juan; Zhu, Qing-Jun

    2018-03-01

    Autophagy plays an important role in alleviating oxidative stress and stabilizing atherosclerotic plaques. However, the potential role of autophagy in endothelial vasodilation function has rarely been studied. This study aimed to investigate whether rhynchophylla total alkaloid (RTA) has a positive role in enhancing autophagy through decreasing oxidative stress, and improving endothelial vasodilation. In oxidized low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs), RTA (200 mg/L) significantly suppressed ox-LDL-induced oxidative stress through rescuing autophagy, and decreased cell apoptosis. In spontaneous hypertensive rats (SHR), administration of RTA (50 mg·kg -1 ·d -1 , ip, for 6 weeks) improved endothelin-dependent vasodilation of thoracic aorta rings. Furthermore, RTA administration significantly increased the antioxidant capacity and alleviated oxidative stress through enhancing autophagy in SHR. In ox-LDL-treated HUVECs, we found that the promotion of autophagy by RTA resulted in activation of the AMP-activated protein kinase (AMPK) signaling pathway. Our results show that RTA treatment rescues the ox-LDL-induced autophagy impairment in HUVECs and improves endothelium-dependent vasodilation function in SHR.

  19. Targeting autophagy as a novel strategy for facilitating the therapeutic action of potentiators on ΔF508 cystic fibrosis transmembrane conductance regulator

    NARCIS (Netherlands)

    A. Luciani (Alessandro); V.R. Villella (Valeria Rachela); S. Esposito (Susanna); M. Gavina (Manuela); I. Russo (Ilaria); M. Silano (Marco); S. Guido (Stefano); M. Pettoello-Mantovani (Massimo); R. Carnuccio (Rosa); B.J. Scholte (Bob); A. de Matteis (Antonella); M.C. Maiuri (Maria Chiara); V. Raia (Valeria); A. Luini (Alberto); H.K. Kroemer (Heyo); L. Maiuri (Luigi)

    2012-01-01

    textabstractChannel activators (potentiators) of cystic fibrosis (CF) transmembrane conductance regulator (CFTR), can be used for the treatment of the small subset of CF patients that carry plasma membrane-resident CFTR mutants. However, approximately 90% of CF patients carry the misfolded

  20. Xylitol induces cell death in lung cancer A549 cells by autophagy.

    Science.gov (United States)

    Park, Eunjoo; Park, Mi Hee; Na, Hee Sam; Chung, Jin

    2015-05-01

    Xylitol is a widely used anti-caries agent that has anti-inflammatory effects. We have evaluated the potential of xylitol in cancer treatment. It's effects on cell proliferation and cytotoxicity were measured by MTT assay and LDH assay. Cell morphology and autophagy were examined by immunostaining and immunoblotting. Xylitol inhibited cell proliferation in a dose-dependent manner in these cancer cells: A549, Caki, NCI-H23, HCT-15, HL-60, K562, and SK MEL-2. The IC50 of xylitol in human gingival fibroblast cells was higher than in cancer cells, indicating that it is more specific for cancer cells. Moreover, xylitol induced autophagy in A549 cells that was inhibited by 3-methyladenine, an autophagy inhibitor. These results indicate that xylitol has potential in therapy against lung cancer by inhibiting cell proliferation and inducing autophagy of A549 cells.

  1. Crosstalk between Apoptosis and Autophagy: Molecular Mechanisms and Therapeutic Strategies in Cancer

    Directory of Open Access Journals (Sweden)

    Abdelouahid El-Khattouti

    2013-01-01

    Full Text Available Both apoptosis and autophagy are highly conserved processes that besides their role in the maintenance of the organismal and cellular homeostasis serve as a main target of tumor therapeutics. Although their important roles in the modulation of tumor therapeutic strategies have been widely reported, the molecular actions of both apoptosis and autophagy are counteracted by cancer protective mechanisms. While apoptosis is a tightly regulated process that is implicated in the removal of damaged or unwanted cells, autophagy is a cellular catabolic pathway that is involved in lysosomal degradation and recycling of proteins and organelles, and thereby is considered an important survival/protective mechanism for cancer cells in response to metabolic stress or chemotherapy. Although the relationship between autophagy and cell death is very complicated and has not been characterized in detail, the molecular mechanisms that control this relationship are considered to be a relevant target for the development of a therapeutic strategy for tumor treatment. In this review, we focus on the molecular mechanisms of apoptosis, autophagy, and those of the crosstalk between apoptosis and autophagy in order to provide insight into the molecular mechanisms that may be essential for the balance between cell survival and death as well as their role as targets for the development of novel therapeutic approaches.

  2. The life span-prolonging effect of sirtuin-1 is mediated by autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Maiuri, Maria Chiara; Markaki, Maria; Megalou, Evgenia; Pasparaki, Angela; Palikaras, Konstantinos; Criollo, Alfredo; Galluzzi, Lorenzo; Malik, Shoaib Ahmad; Vitale, Ilio; Michaud, Mickael; Madeo, Frank; Tavernarakis, Nektarios; Kroemer, Guido

    2010-01-01

    The life span of various model organisms can be extended by caloric restriction as well as by autophagy-inducing pharmacological agents. Life span-prolonging effects have also been observed in yeast cells, nematodes and flies upon the overexpression of the deacetylase Sirtuin-1. Intrigued by these observations and by the established link between caloric restriction and Sirtuin-1 activation, we decided to investigate the putative implication of Sirtuin-1 in the response of human cancer cells and Caenorhabditis elegans to multiple triggers of autophagy. Our data indicate that the activation of Sirtuin-1 (by the pharmacological agent resveratrol and/or genetic means) per se ignites autophagy, and that Sirtuin-1 is required for the autophagic response to nutrient deprivation, in both human and nematode cells, but not for autophagy triggered by downstream signals such as the inhibition of mTOR or p53. Since the life spanextending effects of Sirtuin-1 activators are lost in autophagy-deficient C. elegans, our results suggest that caloric restriction and resveratrol extend longevity, at least in experimental settings, by activating autophagy.

  3. p53 represses autophagy in a cell cycle-dependent fashion.

    Science.gov (United States)

    Tasdemir, Ezgi; Maiuri, Maria Chiara; Orhon, Idil; Kepp, Oliver; Morselli, Eugenia; Criollo, Alfredo; Kroemer, Guido

    2008-10-01

    Autophagy is one of the principal mechanisms of cellular defense against nutrient depletion and damage to cytoplasmic organelles. When p53 is inhibited by a pharmacological antagonist (cyclic pifithrin-alpha), depleted by a specific small interfering RNA (siRNA) or deleted by homologous recombination, multiple signs of autophagy are induced. Here, we show by epistatic analysis that p53 inhibition results in a maximum level of autophagy that cannot be further enhanced by a variety of different autophagy inducers including lithium, tunicamycin-induced stress of the endoplasmic reticulum (ER) or inhibition of Bcl-2 and Bcl-X(L) with the BH3 mimetic ABT737. Chemical inducers of autophagy (including rapamycin, lithium, tunicamycin and ABT737) induced rapid depletion of the p53 protein. The absence or the inhibition of p53 caused autophagy mostly in the G(1) phase, less so in the S phase and spares the G(2)/M phase of the cell cycle. The possible pathophysiological implications of these findings are discussed.

  4. Autophagy in Stem Cell Biology: A Perspective on Stem Cell Self-Renewal and Differentiation

    Directory of Open Access Journals (Sweden)

    Xihang Chen

    2018-01-01

    Full Text Available Autophagy is a highly conserved cellular process that degrades modified, surplus, or harmful cytoplasmic components by sequestering them in autophagosomes which then fuses with the lysosome for degradation. As a major intracellular degradation and recycling pathway, autophagy is crucial for maintaining cellular homeostasis, as well as for remodeling during normal development. Impairment of this process has been implicated in various diseases, in the pathogenic response to bacterial and viral infections, and in aging. Pluripotent stem cells, with their ability to self-replicate and to give rise to any specialized cell type, are very valuable resources for cell-based medical therapies and open a number of promising avenues for studying human development and disease. It has been suggested that autophagy is vital for the maintenance of cellular homeostasis in stem cells, and subsequently more in-depth knowledge about the regulation of autophagy in stem cell biology has been acquired recently. In this review, we describe the most significant advances in the understanding of autophagy regulation in hematopoietic and mesenchymal stem cells, as well as in induced pluripotent stem cells. In particular, we highlight the roles of various autophagy activities in the regulation of self-renewal and differentiation of these stem cells.

  5. Nobel Prize Honors Autophagy Discovery.

    Science.gov (United States)

    2016-12-01

    Japanese cell biologist Yoshinori Ohsumi, PhD, was awarded this year's Nobel Prize in Physiology or Medicine for his discovery of autophagy. His groundbreaking studies in yeast cells illuminated how cells break down and recycle damaged material, a process that is critical to the survival of both normal cells and some cancer cells. ©2016 American Association for Cancer Research.

  6. Human Papilloma Virus and Autophagy

    Directory of Open Access Journals (Sweden)

    Domenico Mattoscio

    2018-06-01

    Full Text Available Human papilloma viruses (HPVs are a group of double-stranded DNA viruses known to be the primary cause of cervical cancer. In addition, evidence has now established their role in non-melanoma skin cancers, head and neck cancer (HNC, and the development of other anogenital malignancies. The prevalence of HPV-related HNC, in particular oropharyngeal cancers, is rapidly increasing, foreseeing that HPV-positive oropharyngeal cancers will outnumber uterine cervical cancers in the next 15–20 years. Therefore, despite the successful advent of vaccines originally licensed for cervical cancer prevention, HPV burden is still very high, and a better understanding of HPV biology is urgently needed. Autophagy is the physiological cellular route that accounts for removal, degradation, and recycling of damaged organelles, proteins, and lipids in lysosomal vacuoles. In addition to this scavenger function, autophagy plays a fundamental role during viral infections and cancers and is, therefore, frequently exploited by viruses to their own benefit. Recently, a link between HPV and autophagy has clearly emerged, leading to the conceivable development of novel anti-viral strategies aimed at restraining HPV infectivity. Here, recent findings on how oncogenic HPV16 usurp autophagy are described, highlighting similarities and differences with mechanisms adopted by other oncoviruses.

  7. Inhibiting ROS-TFEB-Dependent Autophagy Enhances Salidroside-Induced Apoptosis in Human Chondrosarcoma Cells.

    Science.gov (United States)

    Zeng, Wei; Xiao, Tao; Cai, Anlie; Cai, Weiliang; Liu, Huanhuan; Liu, Jingling; Li, Jie; Tan, Miduo; Xie, Li; Liu, Ying; Yang, Xiangcheng; Long, Yi

    2017-01-01

    Autophagy modulation has been considered a potential therapeutic strategy for human chondrosarcoma, and a previous study indicated that salidroside exhibits significant anti-carcinogenic activity. However, the ability of salidroside to induce autophagy and its role in human chondrosarcoma cell death remains unclear. We exposed SW1353 cells to different concentrations of salidroside (0.5, 1 and 2 mM) for 24 h. RT-PCR, Western-blotting, Immunocytofluorescence, and Luciferase Reporter Assays were used to evaluate whether salidroside activated the TFEB-dependent autophagy. We show that salidroside induced significant apoptosis in the human chondrosarcoma cell line SW1353. In addition, we demonstrate that salidroside-induced an autophagic response in SW1353 cells, as evidenced by the upregulation of LC3-II and downregulation of P62. Moreover, pharmacological or genetic blocking of autophagy enhanced salidroside -induced apoptosis, indicating the cytoprotective role of autophagy in salidroside-treated SW1353 cells. Salidroside also induced TFEB (Ser142) dephosphorylation, subsequently to activated TFEB nuclear translocation and increase of TFEB reporter activity, which contributed to lysosomal biogenesis and the expression of autophagy-related genes. Importantly, we found that salidroside triggered the generation of ROS in SW1353 cells. Furthermore, NAC, a ROS scavenger, abrogated the effects of salidroside on TFEB-dependent autophagy. These data demonstrate that salidroside increased TFEB-dependent autophagy by activating ROS signaling pathways in human chondrosarcoma cells. These data also suggest that blocking ROS-TFEB-dependent autophagy to enhance the activity of salidroside warrants further attention in treatment of human chondrosarcoma cells. © 2017 The Author(s). Published by S. Karger AG, Basel.

  8. SIRT1 inactivation induces inflammation through the dysregulation of autophagy in human THP-1 cells

    International Nuclear Information System (INIS)

    Takeda-Watanabe, Ai; Kitada, Munehiro; Kanasaki, Keizo; Koya, Daisuke

    2012-01-01

    Highlights: ► SIRT1 inactivation decreases autophagy in THP-1 cell. ► Inhibition of autophagy induces inflammation. ► SIRT1 inactivation induces inflammation through NF-κB activation. ► The p62/Sqstm1 accumulation by impairment of autophagy is related to NF-κB activation. ► SIRT1 inactivation is involved in the activation of mTOR and decreased AMPK activation. -- Abstract: Inflammation plays a crucial role in atherosclerosis. Monocytes/macrophages are some of the cells involved in the inflammatory process in atherogenesis. Autophagy exerts a protective effect against cellular stresses like inflammation, and it is regulated by nutrient-sensing pathways. The nutrient-sensing pathway includes SIRT1, a NAD + -dependent histone deacetylase, which is implicated in the regulation of a variety of cellular processes including inflammation and autophagy. The mechanism through which the dysfunction of SIRT1 contributes to the regulation of inflammation in relation to autophagy in monocytes/macrophages is unclear. In the present study, we demonstrate that treatment with 2-[(2-Hydroxynaphthalen-1-ylmethylene)amino]-N-(1-phenethyl)benzamide (Sirtinol), a chemical inhibitor of SIRT1, induces the overexpression of inflammation-related genes such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 through nuclear factor (NF)-κB signaling activation, which is associated with autophagy dysfunction, as shown through p62/Sqstm1 accumulation and decreased expression of light chain (LC) 3 II in THP-1 cells. The autophagy inhibitor, 3-methyladenine, also induces inflammation-related NF-κB activation. In p62/Sqstm1 knockdown cells, Sirtinol-induced inflammation through NF-κB activation is blocked. In addition, inhibition of SIRT1 is involved in the activation of the mammalian target of rapamycin (mTOR) pathway and is implicated in decreased 5′-AMP activated kinase (AMPK) activation, leading to the impairment of autophagy. The mTOR inhibitor, rapamycin, abolishes

  9. SIRT1 inactivation induces inflammation through the dysregulation of autophagy in human THP-1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Takeda-Watanabe, Ai; Kitada, Munehiro; Kanasaki, Keizo [Diabetology and Endocrinology, Kanazawa Medical University, Kahoku-Gun, Ishikawa (Japan); Koya, Daisuke, E-mail: koya0516@kanazawa-med.ac.jp [Diabetology and Endocrinology, Kanazawa Medical University, Kahoku-Gun, Ishikawa (Japan)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer SIRT1 inactivation decreases autophagy in THP-1 cell. Black-Right-Pointing-Pointer Inhibition of autophagy induces inflammation. Black-Right-Pointing-Pointer SIRT1 inactivation induces inflammation through NF-{kappa}B activation. Black-Right-Pointing-Pointer The p62/Sqstm1 accumulation by impairment of autophagy is related to NF-{kappa}B activation. Black-Right-Pointing-Pointer SIRT1 inactivation is involved in the activation of mTOR and decreased AMPK activation. -- Abstract: Inflammation plays a crucial role in atherosclerosis. Monocytes/macrophages are some of the cells involved in the inflammatory process in atherogenesis. Autophagy exerts a protective effect against cellular stresses like inflammation, and it is regulated by nutrient-sensing pathways. The nutrient-sensing pathway includes SIRT1, a NAD{sup +}-dependent histone deacetylase, which is implicated in the regulation of a variety of cellular processes including inflammation and autophagy. The mechanism through which the dysfunction of SIRT1 contributes to the regulation of inflammation in relation to autophagy in monocytes/macrophages is unclear. In the present study, we demonstrate that treatment with 2-[(2-Hydroxynaphthalen-1-ylmethylene)amino]-N-(1-phenethyl)benzamide (Sirtinol), a chemical inhibitor of SIRT1, induces the overexpression of inflammation-related genes such as tumor necrosis factor (TNF)-{alpha} and interleukin (IL)-6 through nuclear factor (NF)-{kappa}B signaling activation, which is associated with autophagy dysfunction, as shown through p62/Sqstm1 accumulation and decreased expression of light chain (LC) 3 II in THP-1 cells. The autophagy inhibitor, 3-methyladenine, also induces inflammation-related NF-{kappa}B activation. In p62/Sqstm1 knockdown cells, Sirtinol-induced inflammation through NF-{kappa}B activation is blocked. In addition, inhibition of SIRT1 is involved in the activation of the mammalian target of rapamycin (mTOR) pathway and

  10. Autophagy Protects against CYP2E1/Chronic Ethanol-Induced Hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Yongke Lu

    2015-10-01

    Full Text Available Autophagy is an intracellular pathway by which lysosomes degrade and recycle long-lived proteins and cellular organelles. The effects of ethanol on autophagy are complex but recent studies have shown that autophagy serves a protective function against ethanol-induced liver injury. Autophagy was found to also be protective against CYP2E1-dependent toxicity in vitro in HepG2 cells which express CYP2E1 and in vivo in an acute alcohol/CYPE1-dependent liver injury model. The goal of the current report was to extend the previous in vitro and acute in vivo experiments to a chronic ethanol model to evaluate whether autophagy is also protective against CYP2E1-dependent liver injury in a chronic ethanol-fed mouse model. Wild type (WT, CYP2E1 knockout (KO or CYP2E1 humanized transgenic knockin (KI, mice were fed an ethanol liquid diet or control dextrose diet for four weeks. In the last week, some mice received either saline or 3-methyladenine (3-MA, an inhibitor of autophagy, or rapamycin, which stimulates autophagy. Inhibition of autophagy by 3-MA potentiated the ethanol-induced increases in serum transaminase and triglyceride levels in the WT and KI mice but not KO mice, while rapamycin prevented the ethanol liver injury. Treatment with 3-MA enhanced the ethanol-induced fat accumulation in WT mice and caused necrosis in the KI mice; little or no effect was found in the ethanol-fed KO mice or any of the dextrose-fed mice. 3-MA treatment further lowered the ethanol-decrease in hepatic GSH levels and further increased formation of TBARS in WT and KI mice, whereas rapamycin blunted these effects of ethanol. Neither 3-MA nor rapamycin treatment affected CYP2E1 catalytic activity or content or the induction CYP2E1 by ethanol. The 3-MA treatment decreased levels of Beclin-1 and Atg 7 but increased levels of p62 in the ethanol-fed WT and KI mice whereas rapamycin had the opposite effects, validating inhibition and stimulation of autophagy, respectively. These

  11. Feedback regulation between autophagy and PKA.

    Science.gov (United States)

    Torres-Quiroz, Francisco; Filteau, Marie; Landry, Christian R

    2015-01-01

    Protein kinase A (PKA) controls diverse cellular processes and homeostasis in eukaryotic cells. Many processes and substrates of PKA have been described and among them are direct regulators of autophagy. The mechanisms of PKA regulation and how they relate to autophagy remain to be fully understood. We constructed a reporter of PKA activity in yeast to identify genes affecting PKA regulation. The assay systematically measures relative protein-protein interactions between the regulatory and catalytic subunits of the PKA complex in a systematic set of genetic backgrounds. The candidate PKA regulators we identified span multiple processes and molecular functions (autophagy, methionine biosynthesis, TORC signaling, protein acetylation, and DNA repair), which themselves include processes regulated by PKA. These observations suggest the presence of many feedback loops acting through this key regulator. Many of the candidate regulators include genes involved in autophagy, suggesting that not only does PKA regulate autophagy but that autophagy also sends signals back to PKA.

  12. Autophagy is essential for hearing in mice.

    Science.gov (United States)

    Fujimoto, Chisato; Iwasaki, Shinichi; Urata, Shinji; Morishita, Hideaki; Sakamaki, Yuriko; Fujioka, Masato; Kondo, Kenji; Mizushima, Noboru; Yamasoba, Tatsuya

    2017-05-11

    Hearing loss is the most frequent sensory disorder in humans. Auditory hair cells (HCs) are postmitotic at late-embryonic differentiation and postnatal stages, and their damage is the major cause of hearing loss. There is no measurable HC regeneration in the mammalian cochlea, and the maintenance of cell function is crucial for preservation of hearing. Here we generated mice deficient in autophagy-related 5 (Atg5), a gene essential for autophagy, in the HCs to investigate the effect of basal autophagy on hearing acuity. Deletion of Atg5 resulted in HC degeneration and profound congenital hearing loss. In autophagy-deficient HCs, polyubiquitinated proteins and p62/SQSTM1, an autophagy substrate, accumulated as inclusion bodies during the first postnatal week, and these aggregates increased in number. These findings revealed that basal autophagy has an important role in maintenance of HC morphology and hearing acuity.

  13. Osteoporosis and autophagy: What is the relationship?

    Directory of Open Access Journals (Sweden)

    Rinaldo Florencio-Silva

    Full Text Available Summary Autophagy is a survival pathway wherein non-functional proteins and organelles are degraded in lysosomes for recycling and energy production. Therefore, autophagy is fundamental for the maintenance of cell viability, acting as a quality control process that prevents the accumulation of unnecessary structures and oxidative stress. Increasing evidence has shown that autophagy dysfunction is related to several pathologies including neurodegenerative diseases and cancer. Moreover, recent studies have shown that autophagy plays an important role for the maintenance of bone homeostasis. For instance, in vitro and animal and human studies indicate that autophagy dysfunction in bone cells is associated with the onset of bone diseases such as osteoporosis. This review had the purpose of discussing the issue to confirm whether a relationship between autophagy dysfunction and osteoporosis exits.

  14. Autophagy in the control of food intake

    OpenAIRE

    Singh, Rajat

    2012-01-01

    The cellular nutrient sensing apparatus detects nutritional depletion and transmits this information to downstream effectors that generate energy from alternate sources. Autophagy is a crucial catabolic pathway that turns over redundant cytoplasmic components in lysosomes to provide energy to the starved cell. Recent studies have described a role for hypothalamic autophagy in the control of food intake and energy balance. Activated autophagy in hypothalamic neurons during starvation mobilized...

  15. Crosstalk of Autophagy and the Secretory Pathway and Its Role in Diseases.

    Science.gov (United States)

    Zahoor, Muhammad; Farhan, Hesso

    2018-01-01

    The secretory and autophagic pathways are two fundamental, evolutionary highly conserved endomembrane processes. Typically, secretion is associated with biosynthesis and delivery of proteins. In contrast, autophagy is usually considered as a degradative pathway. Thus, an analogy to metabolic pathways is evident. Anabolic (biosynthetic) and catabolic (degradative) pathways are usually intimately linked and intertwined, and likewise, the secretory and autophagy pathways are intertwined. Investigation of this link is an emerging area of research, and we will provide an overview of some of the major advances that have been made to contribute to understanding of how secretion regulates autophagy and vice versa. Finally, we will highlight evidence that supports a potential involvement of the autophagy-secretion crosstalk in human diseases. © 2018 Elsevier Inc. All rights reserved.

  16. A Yin-Yang 1/miR-30a regulatory circuit modulates autophagy in pancreatic cancer cells.

    Science.gov (United States)

    Yang, Chuang; Zhang, Jing-Jing; Peng, Yun-Peng; Zhu, Yi; Yin, Ling-Di; Wei, Ji-Shu; Gao, Wen-Tao; Jiang, Kui-Rong; Miao, Yi

    2017-10-19

    Autophagy is a highly regulated biological process that mediates the degradation of intracellular components. It is required for tumor cell metabolism and homeostasis. Yin-Yang 1 (YY1) has been reported to be involved in autophagy in several carcinomas. However, its role in autophagy in pancreatic cancer, one of the deadliest human malignancies, is unknown. Here, we investigated the function of YY1 in pancreatic cancer cells autophagy and its mechanisms of action. The activity of cells undergoing autophagy was assessed using transmission electron microscopy, immunofluorescence, and Western blotting. A luciferase activity assay, real-time quantitative polymerase chain reaction (RT-qPCR), and chromatin immunoprecipitation (ChIP) were also used to identify putative downstream targets of YY1. YY1 was confirmed to regulate autophagy in pancreatic cancer cells. It was found to directly regulate the expression of miR-30a, a known modulator of autophagy-associated genes. Furthermore, overexpression of miR-30a attenuated the pro-autophagic effects of YY1. Cumulatively, our data suggest that miR-30a acts in a feedback loop to modulate the pro-autophagic activities of YY1. Thus, autophagy in pancreatic cancer cells may be regulated, in part, by a tightly coordinated YY1/miR-30a regulatory circuit. These findings provide a potential druggable target for the development of treatments for pancreatic cancer.

  17. Autophagy and the nutritional signaling pathway

    Directory of Open Access Journals (Sweden)

    Long HE,Shabnam ESLAMFAM,Xi MA,Defa LI

    2016-09-01

    Full Text Available During their growth and development, animals adapt to tremendous changes in order to survive. These include responses to both environmental and physiological changes and autophagy is one of most important adaptive and regulatory mechanisms. Autophagy is defined as an autolytic process to clear damaged cellular organelles and recycle the nutrients via lysosomic degradation. The process of autophagy responds to special conditions such as nutrient withdrawal. Once autophagy is induced, phagophores form and then elongate and curve to form autophagosomes. Autophagosomes then engulf cargo, fuse with endosomes, and finally fuse with lysosomes for maturation. During the initiation process, the ATG1/ULK1 (unc-51-like kinase 1 and VPS34 (which encodes a class III phosphatidylinositol (PtdIns 3-kinase complexes are critical in recruitment and assembly of other complexes required for autophagy. The process of autophagy is regulated by autophagy related genes (ATGs. Amino acid and energy starvation mediate autophagy by activating mTORC1 (mammalian target of rapamycin and AMP-activated protein kinase (AMPK. AMPK is the energy status sensor, the core nutrient signaling component and the metabolic kinase of cells. This review mainly focuses on the mechanism of autophagy regulated by nutrient signaling especially for the two important complexes, ULK1 and VPS34.

  18. Regulation of cardiomyocyte autophagy by calcium.

    Science.gov (United States)

    Shaikh, Soni; Troncoso, Rodrigo; Criollo, Alfredo; Bravo-Sagua, Roberto; García, Lorena; Morselli, Eugenia; Cifuentes, Mariana; Quest, Andrew F G; Hill, Joseph A; Lavandero, Sergio

    2016-04-15

    Calcium signaling plays a crucial role in a multitude of events within the cardiomyocyte, including cell cycle control, growth, apoptosis, and autophagy. With respect to calcium-dependent regulation of autophagy, ion channels and exchangers, receptors, and intracellular mediators play fundamental roles. In this review, we discuss calcium-dependent regulation of cardiomyocyte autophagy, a lysosomal mechanism that is often cytoprotective, serving to defend against disease-related stress and nutrient insufficiency. We also highlight the importance of the subcellular distribution of calcium and related proteins, interorganelle communication, and other key signaling events that govern cardiomyocyte autophagy. Copyright © 2016 the American Physiological Society.

  19. Involvement of Autophagy in Coronavirus Replication

    Directory of Open Access Journals (Sweden)

    Paul Britton

    2012-11-01

    Full Text Available Coronaviruses are single stranded, positive sense RNA viruses, which induce the rearrangement of cellular membranes upon infection of a host cell. This provides the virus with a platform for the assembly of viral replication complexes, improving efficiency of RNA synthesis. The membranes observed in coronavirus infected cells include double membrane vesicles. By nature of their double membrane, these vesicles resemble cellular autophagosomes, generated during the cellular autophagy pathway. In addition, coronavirus infection has been demonstrated to induce autophagy. Here we review current knowledge of coronavirus induced membrane rearrangements and the involvement of autophagy or autophagy protein microtubule associated protein 1B light chain 3 (LC3 in coronavirus replication.

  20. Approaches for Studying Autophagy in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Yanfang Chen

    2017-08-01

    Full Text Available Macroautophagy (hereafter referred to as autophagy is an intracellular degradative process, well conserved among eukaryotes. By engulfing cytoplasmic constituents into the autophagosome for degradation, this process is involved in the maintenance of cellular homeostasis. Autophagy induction triggers the formation of a cup-shaped double membrane structure, the phagophore, which progressively elongates and encloses materials to be removed. This double membrane vesicle, which is called an autophagosome, fuses with lysosome and forms the autolysosome. The inner membrane of the autophagosome, along with engulfed compounds, are degraded by lysosomal enzymes, which enables the recycling of carbohydrates, amino acids, nucleotides, and lipids. In response to various factors, autophagy can be induced for non-selective degradation of bulk cytoplasm. Autophagy is also able to selectively target cargoes and organelles such as mitochondria or peroxisome, functioning as a quality control system. The modification of autophagy flux is involved in developmental processes such as resistance to stress conditions, aging, cell death, and multiple pathologies. So, the use of animal models is essential for understanding these processes in the context of different cell types throughout the entire lifespan. For almost 15 years, the nematode Caenorhabditis elegans has emerged as a powerful model to analyze autophagy in physiological or pathological contexts. This review presents a rapid overview of physiological processes involving autophagy in Caenorhabditis elegans, the different assays used to monitor autophagy, their drawbacks, and specific tools for the analyses of selective autophagy.

  1. The prosurvival role of autophagy in Resveratrol-induced cytotoxicity in human U251 glioma cells

    International Nuclear Information System (INIS)

    Li, Jun; Qin, Zhenghong; Liang, Zhongqin

    2009-01-01

    Previous study reported that resveratrol has anti-tumor activity. In this study, we investigated the involvement of autophagy in the resveratrol-induced apoptotic death of human U251 glioma cells. The growth inhibition of U251 cells induced by resveratrol was assessed with methyl thiazolyl tetrazolium (MTT). The activation of autophagy and proapoptotic effect were characterized by monodansylcadaverine labeling and Hoechst stain, respectively. Mitochondrialtransmembrane potential (ΔΨm) was measured as a function of drug treatment using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1). The role of autophagy and apoptosis in the resveratrol-induced death of U251 cells was assessed using autophagic and caspase inhibitors. Immunofluorescence, flow cytometry, and Western blot analysis were used to study the apoptotic and autophagic mechanisms. Methyl thiazolyl tetrazolium (MTT) assays indicated that resveratrol decreased the viability of U251 cells in a dose- and time-dependent manner. Flow cytometry analysis indicated that resveratrol increased cell population at sub-G1 phase, an index of apoptosis. Furthermore, resveratrol-induced cell death was associated with a collapse of the mitochondrial membrane potential. The pan-caspase inhibitor Z-VAD-fmk suppressed resveratrol-induced U251 cell death. Resveratrol stimulated autophagy was evidenced by punctuate monodansylcadaverine(MDC) staining and microtubule-associated protein light chain 3 (LC3) immunoreactivty. Resveratrol also increased protein levels of beclin 1 and membrane form LC3 (LC3-II). Autophagy inhibitors 3-methylademine (3-MA) and bafilomycin A1 sensitized the cytotoxicity of resveratrol. Together, these findings indicate that resveratrol induces autophagy in human U251 glioma cells and autophagy suppressed resveratrol-induced apoptosis. This study thus suggests that autophagy inhibitors can increase the cytotoxicity of resveratrol to glioma cells

  2. Alix differs from ESCRT proteins in the control of autophagy

    International Nuclear Information System (INIS)

    Petiot, Anne; Strappazzon, Flavie; Chatellard-Causse, Christine; Blot, Beatrice; Torch, Sakina; Jean-Marc Verna; Sadoul, Remy

    2008-01-01

    Alix/AIP1 is a cytosolic protein that regulates cell death through mechanisms that remain unclear. Alix binds to two protein members of the so-called Endosomal Sorting Complex Required for Transport (ESCRT), which facilitates membrane fission events during multivesicular endosome formation, enveloped virus budding and cytokinesis. Alix itself has been suggested to participate in these cellular events and is thus often considered to function in the ESCRT pathway. ESCRT proteins were recently implicated in autophagy, a process involved in bulk degradation of cytoplasmic constituents in lysosomes, which can also participate in cell death. In this study, we shown that, unlike ESCRT proteins, Alix is not involved in autophagy. These results strongly suggest that the capacity of several mutants of Alix to block both caspase-dependent and independent cell death does not relate to their capacity to modulate autophagy. Furthermore, they reinforce the conclusion of other studies demonstrating that the role of Alix is different from that of classical ESCRT proteins

  3. Characterization of the autophagy marker protein Atg8 reveals atypical features of autophagy in Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Rahul Navale

    Full Text Available Conventional autophagy is a lysosome-dependent degradation process that has crucial homeostatic and regulatory functions in eukaryotic organisms. As malaria parasites must dispose a number of self and host cellular contents, we investigated if autophagy in malaria parasites is similar to the conventional autophagy. Genome wide analysis revealed a partial autophagy repertoire in Plasmodium, as homologs for only 15 of the 33 yeast autophagy proteins could be identified, including the autophagy marker Atg8. To gain insights into autophagy in malaria parasites, we investigated Plasmodium falciparum Atg8 (PfAtg8 employing techniques and conditions that are routinely used to study autophagy. Atg8 was similarly expressed and showed punctate localization throughout the parasite in both asexual and sexual stages; it was exclusively found in the pellet fraction as an integral membrane protein, which is in contrast to the yeast or mammalian Atg8 that is distributed among cytosolic and membrane fractions, and suggests for a constitutive autophagy. Starvation, the best known autophagy inducer, decreased PfAtg8 level by almost 3-fold compared to the normally growing parasites. Neither the Atg8-associated puncta nor the Atg8 expression level was significantly altered by treatment of parasites with routinely used autophagy inhibitors (cysteine (E64 and aspartic (pepstatin protease inhibitors, the kinase inhibitor 3-methyladenine, and the lysosomotropic agent chloroquine, indicating an atypical feature of autophagy. Furthermore, prolonged inhibition of the major food vacuole protease activity by E64 and pepstatin did not cause accumulation of the Atg8-associated puncta in the food vacuole, suggesting that autophagy is primarily not meant for degradative function in malaria parasites. Atg8 showed partial colocalization with the apicoplast; doxycycline treatment, which disrupts apicoplast, did not affect Atg8 localization, suggesting a role, but not exclusive, in

  4. Mitofusin 2 Exerts a Protective Role in Ischemia Reperfusion Injury Through Increasing Autophagy

    Directory of Open Access Journals (Sweden)

    Cheng Peng

    2018-05-01

    Full Text Available Background/Aims: Autophagy is essential for maintaining cellular homeostasis and the survival of terminally differentiated cells as neurons. In this study, we aim to investigate whether mitofusin 2, a mitochondrial fusion protein, mediates autophagy in cerebral ischemia/reperfusion (I/R injury. Methods: Primary cultured neurons were treated with oxygen-glucose deprivation/reperfusion to mimic cerebral I/R injury in vitro. Autophagosomes were visualized upon TEM. Autophagy-markers were then detected to monitor autophagy by western-blot and real-time PCR, and the autophagic flux was tracked with a mRFP-GFP-LC3 construct by fluorescence as well as autophagy inhibitors and agonists. The up- and downregulation of Mfn2 were through transfecting a lentivirusexpression vector respectively. And neuronal injury was detected by cell counting kit and TUNEL assay. Results: Results showed I/R increased autophagosome formation and inhibited autolysosome degradation. Furthermore, use of autophagy related agents demonstrated that I/R injury was caused by insufficient autophagy and aggravated by impaired autophagic degradation. The results also indicated that mitofusin 2 could ameliorate I/R injury through increasing autophagosome formation and promoting the fusion of autophagosomes and lysosomes. In contrast, downregulation of mitofusin 2 aggravated the I/R injury by inhibiting autophagosome formation and the fusion of autophagosomes and lysosomes. Additionly, mitofusin 2 overexpression did not lead to autolysosome accumulation induced by I/R. Conclusions: In summary, this study explicitly demonstrated that mitofusin 2 could ameliorate I/R injury mainly through promoting autophagy, which represented a potential novel strategy for neuroprotection against cerebral I/R damage.

  5. 20-hydroxyecdysone upregulates Atg genes to induce autophagy in the Bombyx fat body

    Science.gov (United States)

    Tian, Ling; Ma, Li; Guo, Enen; Deng, Xiaojuan; Ma, Sanyuan; Xia, Qingyou; Cao, Yang; Li, Sheng

    2013-01-01

    Autophagy is finely regulated at multiple levels and plays crucial roles in development and disease. In the fat body of the silkworm, Bombyx mori, autophagy occurs and Atg gene expression peaks during the nonfeeding molting and pupation stages when the steroid hormone (20-hydroxyecdysone; 20E) is high. Injection of 20E into the feeding larvae upregulated Atg genes and reduced TORC1 activity resulting in autophagy induction in the fat body. Conversely, RNAi knockdown of the 20E receptor partner (USP) or targeted overexpression of a dominant negative mutant of the 20E receptor (EcRDN) in the larval fat body reduced autophagy and downregulated the Atg genes, confirming the importance of 20E-induction of Atg gene expression during pupation. Moreover, in vitro treatments of the larval fat body with 20E upregulated the Atg genes. Five Atg genes were potentially 20E primary-responsive, and a 20E response element was identified in the Atg1 (ortholog of human ULK1) promoter region. Furthermore, RNAi knockdown of 4 key genes (namely Br-C, E74, HR3 and βftz-F1) in the 20E-triggered transcriptional cascade reduced autophagy and downregulated Atg genes to different levels. Taken together, we conclude that in addition to blocking TORC1 activity for autophagosome initiation, 20E upregulates Atg genes to induce autophagy in the Bombyx fat body. PMID:23674061

  6. Till Death Do Us Part: The Marriage of Autophagy and Apoptosis

    Directory of Open Access Journals (Sweden)

    Katrina F. Cooper

    2018-01-01

    Full Text Available Autophagy is a widely conserved catabolic process that is necessary for maintaining cellular homeostasis under normal physiological conditions and driving the cell to switch back to this status quo under times of starvation, hypoxia, and oxidative stress. The potential similarities and differences between basal autophagy and stimulus-induced autophagy are still largely unknown. Both act by clearing aberrant or unnecessary cytoplasmic material, such as misfolded proteins, supernumerary and defective organelles. The relationship between reactive oxygen species (ROS and autophagy is complex. Cellular ROS is predominantly derived from mitochondria. Autophagy is triggered by this event, and by clearing the defective organelles effectively, it lowers cellular ROS thereby restoring cellular homeostasis. However, if cellular homeostasis cannot be reached, the cells can switch back and choose a regulated cell death response. Intriguingly, the autophagic and cell death machines both respond to the same stresses and share key regulatory proteins, suggesting that the pathways are intricately connected. Here, the intersection between autophagy and apoptosis is discussed with a particular focus on the role ROS plays.

  7. Regulation of autophagy by cytoplasmic p53.

    Science.gov (United States)

    Tasdemir, Ezgi; Maiuri, M Chiara; Galluzzi, Lorenzo; Vitale, Ilio; Djavaheri-Mergny, Mojgan; D'Amelio, Marcello; Criollo, Alfredo; Morselli, Eugenia; Zhu, Changlian; Harper, Francis; Nannmark, Ulf; Samara, Chrysanthi; Pinton, Paolo; Vicencio, José Miguel; Carnuccio, Rosa; Moll, Ute M; Madeo, Frank; Paterlini-Brechot, Patrizia; Rizzuto, Rosario; Szabadkai, Gyorgy; Pierron, Gérard; Blomgren, Klas; Tavernarakis, Nektarios; Codogno, Patrice; Cecconi, Francesco; Kroemer, Guido

    2008-06-01

    Multiple cellular stressors, including activation of the tumour suppressor p53, can stimulate autophagy. Here we show that deletion, depletion or inhibition of p53 can induce autophagy in human, mouse and nematode cells subjected to knockout, knockdown or pharmacological inhibition of p53. Enhanced autophagy improved the survival of p53-deficient cancer cells under conditions of hypoxia and nutrient depletion, allowing them to maintain high ATP levels. Inhibition of p53 led to autophagy in enucleated cells, and cytoplasmic, not nuclear, p53 was able to repress the enhanced autophagy of p53(-/-) cells. Many different inducers of autophagy (for example, starvation, rapamycin and toxins affecting the endoplasmic reticulum) stimulated proteasome-mediated degradation of p53 through a pathway relying on the E3 ubiquitin ligase HDM2. Inhibition of p53 degradation prevented the activation of autophagy in several cell lines, in response to several distinct stimuli. These results provide evidence of a key signalling pathway that links autophagy to the cancer-associated dysregulation of p53.

  8. Tumor Suppression and Promotion by Autophagy

    Directory of Open Access Journals (Sweden)

    Yenniffer Ávalos

    2014-01-01

    Full Text Available Autophagy is a highly regulated catabolic process that involves lysosomal degradation of proteins and organelles, mostly mitochondria, for the maintenance of cellular homeostasis and reduction of metabolic stress. Problems in the execution of this process are linked to different pathological conditions, such as neurodegeneration, aging, and cancer. Many of the proteins that regulate autophagy are either oncogenes or tumor suppressor proteins. Specifically, tumor suppressor genes that negatively regulate mTOR, such as PTEN, AMPK, LKB1, and TSC1/2 stimulate autophagy while, conversely, oncogenes that activate mTOR, such as class I PI3K, Ras, Rheb, and AKT, inhibit autophagy, suggesting that autophagy is a tumor suppressor mechanism. Consistent with this hypothesis, the inhibition of autophagy promotes oxidative stress, genomic instability, and tumorigenesis. Nevertheless, autophagy also functions as a cytoprotective mechanism under stress conditions, including hypoxia and nutrient starvation, that promotes tumor growth and resistance to chemotherapy in established tumors. Here, in this brief review, we will focus the discussion on this ambiguous role of autophagy in the development and progression of cancer.

  9. Tumor suppression and promotion by autophagy.

    Science.gov (United States)

    Ávalos, Yenniffer; Canales, Jimena; Bravo-Sagua, Roberto; Criollo, Alfredo; Lavandero, Sergio; Quest, Andrew F G

    2014-01-01

    Autophagy is a highly regulated catabolic process that involves lysosomal degradation of proteins and organelles, mostly mitochondria, for the maintenance of cellular homeostasis and reduction of metabolic stress. Problems in the execution of this process are linked to different pathological conditions, such as neurodegeneration, aging, and cancer. Many of the proteins that regulate autophagy are either oncogenes or tumor suppressor proteins. Specifically, tumor suppressor genes that negatively regulate mTOR, such as PTEN, AMPK, LKB1, and TSC1/2 stimulate autophagy while, conversely, oncogenes that activate mTOR, such as class I PI3K, Ras, Rheb, and AKT, inhibit autophagy, suggesting that autophagy is a tumor suppressor mechanism. Consistent with this hypothesis, the inhibition of autophagy promotes oxidative stress, genomic instability, and tumorigenesis. Nevertheless, autophagy also functions as a cytoprotective mechanism under stress conditions, including hypoxia and nutrient starvation, that promotes tumor growth and resistance to chemotherapy in established tumors. Here, in this brief review, we will focus the discussion on this ambiguous role of autophagy in the development and progression of cancer.

  10. Autophagy: A Sweet Process in Diabetes

    NARCIS (Netherlands)

    Meijer, Alfred J.; Codogno, Patrice

    2008-01-01

    Autophagy is inhibited by the insulin-amino acid-mTOR signaling pathway. Two papers in this issue of Cell Metabolism (Ebato et al., 2008; Jung et al., 2008) provide evidence that basal autophagy is necessary to maintain the architecture and function of pancreatic beta cells and that its induction in

  11. 14-Deoxy-11,12-didehydroandrographolide induces DDIT3-dependent endoplasmic reticulum stress-mediated autophagy in T-47D breast carcinoma cells

    International Nuclear Information System (INIS)

    Tan, Heng Kean; Muhammad, Tengku Sifzizul Tengku; Tan, Mei Lan

    2016-01-01

    14-Deoxy-11,12-didehydroandrographolide (14-DDA), a major diterpenoid isolated from Andrographis paniculata (Burm.f.) Nees, is known to be cytotoxic and elicits a non-apoptotic cell death in T-47D breast carcinoma cells. In this study, the mechanistic toxicology properties of 14-DDA in T-47D cells were further investigated. 14-DDA is found to induce the formation of endoplasmic reticulum (ER) vacuoles and autophagosomes, with concurrent upregulation of LC3-II in the breast carcinoma cells. It stimulated an increase in cytosolic calcium concentration and caused a collapse in mitochondrial membrane potential in these cells. In addition, both DDIT3 and GADD45A, molecules implicated in ER stress pathway, were significantly upregulated. DDIT3 knockdown suppressed the formation of both ER vacuoles and autophagosomes, indicating that 14-DDA-induced ER stress and autophagy is dependent on this transcription factor. Collectively, it is possible that GADD45A/p38 MAPK/DDIT3 pathway is involved in the 14-DDA-induced ER-stress-mediated autophagy in T-47D cells. - Highlights: • The mechanistic toxicology properties of 14-DDA in T-47D breast carcinoma cells were investigated. • 14-DDA induces the formation of ER vacuoles and autophagosomes, with concurrent upregulation of LC3-II. • It stimulates an increase in cytosolic calcium concentration and causing collapse in the mitochondrial membrane potential. • Both DDIT3 and GADD45A, molecules implicated in ER stress pathway, were significantly upregulated. • 4-DDA induces ER stress-mediated autophagy in T-47D cells possibly via GADD45A/p38 MAPK/DDIT3 pathway.

  12. Tunnelling in a time dependent quartic potential: Possible implications for cosmology

    International Nuclear Information System (INIS)

    Kabir, R; Mukherjee, A

    2014-01-01

    The theory of a real scalar field with an arbitrary potential plays an important role in cosmology, particularly in the context of inflationary scenarios. However, in most applications, the potential is treated as independent of time, whereas in an evolving universe, for example, before the onset of inflation, the potential is actually likely to be changing with time. As pointed out by Berry in the context of single-particle quantum mechanics, the existence of multiple time scales can lead to results that are qualitatively different from those obtained with a static potential. The present paper reports on numerical investigations in a scalar field theory with a double-well potential that depends explicitly on time. The transition rate per unit volume for the decay of the false vacuum is found to depend strongly on time. Possible implications for old inflation are discussed

  13. Potential risks of nanotechnology to humans and environment: implications and response mechanisms in Africa

    CSIR Research Space (South Africa)

    Musee, N

    2011-11-01

    Full Text Available and Nanotechnology Summer School Pretoria, South Africa, 22nd NOV? 2nd DEC 2009 Potential risks of nanotechnology to humans and the environment: implications and response mechanisms in Africa Ndeke Musee, Lucky Sikhwivhilu, Nomakhwezi Nota, Lisa Schaefer... COVISET Conference, Johannesburg, South Africa, 22-25 Nov 2011? CSIR 2006 www.csir.co.za Effect of SWCNT on Eschericia coli (a) SEM image of E. Coli incubated without SWCNTs for 60 min. [Source: Kang et al. / Langmuir 2007, 23...

  14. Autophagy Proteins in Phagocyte Endocytosis and Exocytosis

    Directory of Open Access Journals (Sweden)

    Christian Münz

    2017-09-01

    Full Text Available Autophagy was initially described as a catabolic pathway that recycles nutrients of cytoplasmic constituents after lysosomal degradation during starvation. Since the immune system monitors products of lysosomal degradation via major histocompatibility complex (MHC class II restricted antigen presentation, autophagy was found to process intracellular antigens for display on MHC class II molecules. In recent years, however, it has become apparent that the molecular machinery of autophagy serves phagocytes in many more membrane trafficking pathways, thereby regulating immunity to infectious disease agents. In this minireview, we will summarize the recent evidence that autophagy proteins regulate phagocyte endocytosis and exocytosis for myeloid cell activation, pathogen replication, and MHC class I and II restricted antigen presentation. Selective stimulation and inhibition of the respective functional modules of the autophagy machinery might constitute valid therapeutic options in the discussed disease settings.

  15. PICALM modulates autophagy activity and tau accumulation

    Science.gov (United States)

    Moreau, Kevin; Fleming, Angeleen; Imarisio, Sara; Lopez Ramirez, Ana; Mercer, Jacob L.; Jimenez-Sanchez, Maria; Bento, Carla F.; Puri, Claudia; Zavodszky, Eszter; Siddiqi, Farah; Lavau, Catherine P.; Betton, Maureen; O’Kane, Cahir J.; Wechsler, Daniel S.; Rubinsztein, David C.

    2014-01-01

    Genome-wide association studies have identified several loci associated with Alzheimer’s disease (AD), including proteins involved in endocytic trafficking such as PICALM/CALM (phosphatidylinositol binding clathrin assembly protein). It is unclear how these loci may contribute to AD pathology. Here we show that CALM modulates autophagy and alters clearance of tau, a protein which is a known autophagy substrate and which is causatively linked to AD, both in vitro and in vivo. Furthermore, altered CALM expression exacerbates tau-mediated toxicity in zebrafish transgenic models. CALM influences autophagy by regulating the endocytosis of SNAREs, such as VAMP2, VAMP3 and VAMP8, which have diverse effects on different stages of the autophagy pathway, from autophagosome formation to autophagosome degradation. This study suggests that the AD genetic risk factor CALM modulates autophagy, and this may affect disease in a number of ways including modulation of tau turnover. PMID:25241929

  16. Autophagy in endometriosis: Friend or foe?

    Science.gov (United States)

    Zhan, Lei; Li, Jun; Wei, Bing

    2018-01-01

    Endometriosis is a chronic, estrogen-dependent disease and characterized by the implantation of endometrial glands and stroma deep and haphazardly into the outside the uterine cavity. It affects an estimated 10% of the female population of reproductive age and results in obvious reduction in health-related quality of life. Unfortunately, there is no a consistent theory for the etiology of endometriosis. Furthermore, the endometriosis is hard to diagnose in early stage and the treatment methods are limited. Importantly, emerging evidence has investigated that there is a close relationship between endometriosis and autophagy. However, autophagy is a friend or foe in endometriosis is puzzling, the precise mechanism underlying autophagy in endometriosis has not been fully elucidated yet. Here, we provide an integrated view on the acquired findings of the connections between endometriosis and autophagy. We also discuss which may contribute to the abnormal level of autophagy in endometriosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. The Crosstalk between ROS and Autophagy in the Field of Transplantation Medicine

    Directory of Open Access Journals (Sweden)

    Anne C. Van Erp

    2017-01-01

    Full Text Available Many factors during the transplantation process influence posttransplant graft function and survival, including donor type and age, graft preservation methods (cold storage, machine perfusion, and ischemia-reperfusion injury. Successively, they will lead to cellular and molecular alterations that determine cell and ultimately organ fate. Oxidative stress and autophagy are implicated in posttransplant outcome since they are both affected by the stress responses triggered in each step (donor, preservation, and recipient of the transplantation process. Furthermore, oxidative stress influences autophagy and vice versa. Interestingly, both processes have positive as well as negative effects on graft outcome, suggesting they are tightly linked during the transplantation process. In this review, we discuss the importance, regulation and crosstalk of oxidative signals, and autophagy in the field of transplantation medicine.

  18. Activated cathepsin L is associated with the switch from autophagy to apoptotic death of SH-SY5Y cells exposed to 6-hydroxydopamine

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lingyun, E-mail: lingyunlee@126.com [Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215123 (China); Experimental Center, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Gao, Luyan [Experimental Center, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Song, Yunzhen; Qin, Zheng-Hong [Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215123 (China); Liang, Zhongqin, E-mail: liangzhongqin@suda.edu.cn [Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215123 (China)

    2016-02-12

    Autophagy and apoptosis are common responses to pathological damage in the process of Parkinson's disease (PD), and lysosome dysfunction may contribute to the etiology of PD's neurodegenerative process. In this study, we demonstrated that the neurotoxin 6-hydroxydopamine (6-OHDA) increased autophagy in SH-SY5Y cells, as determined by detection of the lysosome marker lysosomal-associated membrane protein1, the autophagy protein light chain 3 (LC3)-II and the autophagy substrate P62 protein. Meanwhile, autophagy repression with 3-methyladenine accelerated the activation of caspase-3 and PARP and aggravated the cell apoptotic death induced by 6-OHDA. Furthermore, we found that 6-OHDA treatment resulted in a transient increase in the intracellular and nuclear expression of cathepsin L (CTSL). The CTSL inhibitor, Z-FY-CHO, could promote autophagy, decrease accumulation of P62, and block activation of caspase-3 and PARP. Taken together, these results suggest that activation of autophagy may primarily be a protective process in SH-SY5Y cell death induced by 6-OHDA, and the nuclear translocation of CTSL could enhance the cell apoptotic cascade via disturbing autophagy-apoptotic systems in SH-SY5Y cells. Our findings highlight the potential role of CTSL in the cross talk between autophagy and apoptosis, which might be considered a therapeutic strategy for treatment of pathologic conditions associated with neurodegeneration. - Highlights: • Inhibition of autophagy aggravated the cell apoptotic death in SH-SY5Y cells. • Activation of cathepsin L impaired the autophagy pathway. • Activation of cathepsin L enhanced the cell apoptotic cascade. • Cathepsin L involves in the cross talk between autophagy and apoptosis.

  19. Interleukin-6: a bone marrow stromal cell paracrine signal that induces neuroendocrine differentiation and modulates autophagy in bone metastatic PCa cells.

    Science.gov (United States)

    Delk, Nikki A; Farach-Carson, Mary C

    2012-04-01

    Autophagy reallocates nutrients and clears normal cells of damaged proteins and organelles. In the context of metastatic disease, invading cancer cells hijack autophagic processes to survive and adapt in the host microenvironment. We sought to understand how autophagy is regulated in the metastatic niche for prostate cancer (PCa) cells where bone marrow stromal cell (BMSC) paracrine signaling induces PCa neuroendocrine differentiation (NED). In PCa, this transdifferentiation of metastatic PCa cells to neuronal-like cells correlates with advanced disease. Because autophagy provides a survival advantage for cancer cells and promotes cell differentiation, we hypothesized that autophagy mediates PCa NED in the bone. Thus, we determined the ability of paracrine factors in conditioned media (CM) from two separate BMSC subtypes, HS5 and HS27a, to induce autophagy in C4-2 and C4-2B bone metastatic PCa cells by characterizing the autophagy marker, LC3. Unlike HS27a CM, HS5 CM induced LC3 accumulation in PCa cells, suggesting autophagy was induced and indicating that HS5 and HS27a secrete a different milieu of paracrine factors that influence PCa autophagy. We identified interleukin-6 (IL-6), a cytokine more highly expressed in HS5 cells than in HS27a cells, as a paracrine factor that regulates PCa autophagy. Pharmacological inhibition of STAT3 activity did not attenuate LC3 accumulation, implying that IL-6 regulates NED and autophagy through different pathways. Finally, chloroquine inhibition of autophagic flux blocked PCa NED; hence autophagic flux maintains NED. Our studies imply that autophagy is cytoprotective for PCa cells in the bone, thus targeting autophagy is a potential therapeutic strategy.

  20. BAG3-dependent noncanonical autophagy induced by proteasome inhibition in HepG2 cells.

    Science.gov (United States)

    Liu, Bao-Qin; Du, Zhen-Xian; Zong, Zhi-Hong; Li, Chao; Li, Ning; Zhang, Qiang; Kong, De-Hui; Wang, Hua-Qin

    2013-06-01

    Emerging lines of evidence have shown that blockade of ubiquitin-proteasome system (UPS) activates autophagy. The molecular players that regulate the relationship between them remain to be elucidated. Bcl-2 associated athanogene 3 (BAG3) is a member of the BAG co-chaperone family that regulates the ATPase activity of heat shock protein 70 (HSP70) chaperone family. Studies on BAG3 have demonstrated that it plays multiple roles in physiological and pathological processes, including antiapoptotic activity, signal transduction, regulatory role in virus infection, cell adhesion and migration. Recent studies have attracted much attention on its role in initiation of autophagy. The current study, for the first time, demonstrates that proteasome inhibitors elicit noncanonical autophagy, which was not suppressed by inhibitors of class III phosphatidylinositol 3-kinase (PtdIns3K) or shRNA against Beclin 1 (BECN1). In addition, we demonstrate that BAG3 is ascribed to activation of autophagy elicited by proteasome inhibitors and MAPK8/9/10 (also known as JNK1/2/3 respectively) activation is also implicated via upregulation of BAG3. Moreover, we found that noncanonical autophagy mediated by BAG3 suppresses responsiveness of HepG2 cells to proteasome inhibitors.

  1. Hypercholesterolemia downregulates autophagy in the rat heart.

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    Giricz, Zoltán; Koncsos, Gábor; Rajtík, Tomáš; Varga, Zoltán V; Baranyai, Tamás; Csonka, Csaba; Szobi, Adrián; Adameová, Adriana; Gottlieb, Roberta A; Ferdinandy, Péter

    2017-03-23

    We have previously shown that efficiency of ischemic conditioning is diminished in hypercholesterolemia and that autophagy is necessary for cardioprotection. However, it is unknown whether isolated hypercholesterolemia disturbs autophagy or the mammalian target of rapamycin (mTOR) pathways. Therefore, we investigated whether isolated hypercholesterolemia modulates cardiac autophagy-related pathways or programmed cell death mechanisms such as apoptosis and necroptosis in rat heart. Male Wistar rats were fed either normal chow (NORM; n = 9) or with 2% cholesterol and 0.25% cholic acid-enriched diet (CHOL; n = 9) for 12 weeks. CHOL rats exhibited a 41% increase in plasma total cholesterol level over that of NORM rats (4.09 mmol/L vs. 2.89 mmol/L) at the end of diet period. Animals were sacrificed, hearts were excised and briefly washed out. Left ventricles were snap-frozen for determination of markers of autophagy, mTOR pathway, apoptosis, and necroptosis by Western blot. Isolated hypercholesterolemia was associated with a significant reduction in expression of cardiac autophagy markers such as LC3-II, Beclin-1, Rubicon and RAB7 as compared to controls. Phosphorylation of ribosomal S6, a surrogate marker for mTOR activity, was increased in CHOL samples. Cleaved caspase-3, a marker of apoptosis, increased in CHOL hearts, while no difference in the expression of necroptotic marker RIP1, RIP3 and MLKL was detected between treatments. This is the first comprehensive analysis of autophagy and programmed cell death pathways of apoptosis and necroptosis in hearts of hypercholesterolemic rats. Our data show that isolated hypercholesterolemia suppresses basal cardiac autophagy and that the decrease in autophagy may be a result of an activated mTOR pathway. Reduced autophagy was accompanied by increased apoptosis, while cardiac necroptosis was not modulated by isolated hypercholesterolemia. Decreased basal autophagy and elevated apoptosis may be responsible for the

  2. WNK1 is an unexpected autophagy inhibitor

    Science.gov (United States)

    Gallolu Kankanamalage, Sachith; Lee, A-Young; Wichaidit, Chonlarat; Lorente-Rodriguez, Andres; Shah, Akansha M.; Stippec, Steve; Whitehurst, Angelique W.; Cobb, Melanie H.

    2017-01-01

    ABSTRACT Autophagy is a cellular degradation pathway that is essential to maintain cellular physiology, and deregulation of autophagy leads to multiple diseases in humans. In a recent study, we discovered that the protein kinase WNK1 (WNK lysine deficient protein kinase 1) is an inhibitor of autophagy. The loss of WNK1 increases both basal and starvation-induced autophagy. In addition, the depletion of WNK1 increases the activation of the class III phosphatidylinositol 3-kinase (PtdIns3K) complex, which is required to induce autophagy. Moreover, the loss of WNK1 increases the expression of ULK1 (unc-51 like kinase 1), which is upstream of the PtdIns3K complex. It also increases the pro-autophagic phosphorylation of ULK1 at Ser555 and the activation of AMPK (AMP-activated protein kinase), which is responsible for that phosphorylation. The inhibition of AMPK by compound C decreases the magnitude of autophagy induction following WNK1 loss; however, it does not prevent autophagy induction. We found that the UVRAG (UV radiation resistance associated gene), which is a component of the PtdIns3K, binds to the N-terminal region of WNK1. Moreover, WNK1 partially colocalizes with UVRAG and this colocalization decreases when autophagy is stimulated in cells. The loss of WNK1 also alters the cellular distribution of UVRAG. The depletion of the downstream target of WNK1, OXSR1/OSR1 (oxidative-stress responsive 1) has no effect on autophagy, whereas the depletion of its relative STK39/SPAK (serine/threonine kinase 39) induces autophagy under nutrient-rich and starved conditions. PMID:28282258

  3. Cell death and autophagy: Cytokines, drugs, and nutritional factors

    International Nuclear Information System (INIS)

    Bursch, Wilfried; Karwan, Anneliese; Mayer, Miriam; Dornetshuber, Julia; Froehwein, Ulrike; Schulte-Hermann, Rolf; Fazi, Barbara; Di Sano, Federica; Piredda, Lucia; Piacentini, Mauro; Petrovski, Goran; Fesues, Laszlo; Gerner, Christopher

    2008-01-01

    Cells may use multiple pathways to commit suicide. In certain contexts, dying cells generate large amounts of autophagic vacuoles and clear large proportions of their cytoplasm, before they finally die, as exemplified by the treatment of human mammary carcinoma cells with the anti-estrogen tamoxifen (TAM, ≤1 μM). Protein analysis during autophagic cell death revealed distinct proteins of the nuclear fraction including GST-π and some proteasomal subunit constituents to be affected during autophagic cell death. Depending on the functional status of caspase-3, MCF-7 cells may switch between autophagic and apoptotic features of cell death [Fazi, B., Bursch, W., Fimia, G.M., Nardacci R., Piacentini, M., Di Sano, F., Piredda, L., 2008. Fenretinide induces autophagic cell death in caspase-defective breast cancer cells. Autophagy 4(4), 435-441]. Furthermore, the self-destruction of MCF-7 cells was found to be completed by phagocytosis of cell residues [Petrovski, G., Zahuczky, G., Katona, K., Vereb, G., Martinet, W., Nemes, Z., Bursch, W., Fesues, L., 2007. Clearance of dying autophagic cells of different origin by professional and non-professional phagocytes. Cell Death Diff. 14 (6), 1117-1128]. Autophagy also constitutes a cell's strategy of defense upon cell damage by eliminating damaged bulk proteins/organelles. This biological condition may be exemplified by the treatment of MCF-7 cells with a necrogenic TAM-dose (10 μM), resulting in the lysis of almost all cells within 24 h. However, a transient (1 h) challenge of MCF-7 cells with the same dose allowed the recovery of cells involving autophagy. Enrichment of chaperones in the insoluble cytoplasmic protein fraction indicated the formation of aggresomes, a potential trigger for autophagy. In a further experimental model HL60 cells were treated with TAM, causing dose-dependent distinct responses: 1-5 μM TAM, autophagy predominant; 7-9 μM, apoptosis predominant; 15 μM, necrosis. These phenomena might be

  4. Mesenchymal stem cells promote cell invasion and migration and autophagy-induced epithelial-mesenchymal transition in A549 lung adenocarcinoma cells.

    Science.gov (United States)

    Luo, Dan; Hu, Shiyuan; Tang, Chunlan; Liu, Guoxiang

    2018-03-01

    Mesenchymal stem cells (MSCs) are recruited into the tumour microenvironment and promote tumour growth and metastasis. Tumour microenvironment-induced autophagy is considered to suppress primary tumour formation by impairing migration and invasion. Whether these recruited MSCs regulate tumour autophagy and whether autophagy affects tumour growth are controversial. Our data showed that MSCs promote autophagy activation, reactive oxygen species production, and epithelial-mesenchymal transition (EMT) as well as increased migration and invasion in A549 cells. Decreased expression of E-cadherin and increased expression of vimentin and Snail were observed in A549 cells cocultured with MSCs. Conversely, MSC coculture-mediated autophagy positively promoted tumour EMT. Autophagy inhibition suppressed MSC coculture-mediated EMT and reduced A549 cell migration and invasion slightly. Furthermore, the migratory and invasive abilities of A549 cells were additional increased when autophagy was further enhanced by rapamycin treatment. Taken together, this work suggests that microenvironments containing MSCs can promote autophagy activation for enhancing EMT; MSCs also increase the migratory and invasive abilities of A549 lung adenocarcinoma cells. Mesenchymal stem cell-containing microenvironments and MSC-induced autophagy signalling may be potential targets for blocking lung cancer cell migration and invasion. Copyright © 2018 John Wiley & Sons, Ltd.

  5. Oxidative stress in sickle cell disease; pathophysiology and potential implications for disease management.

    Science.gov (United States)

    Nur, Erfan; Biemond, Bart J; Otten, Hans-Martin; Brandjes, Dees P; Schnog, John-John B

    2011-06-01

    Sickle cell disease (SCD) is a hemoglobinopathy characterized by hemolytic anemia, increased susceptibility to infections and vaso-occlusion leading to a reduced quality of life and life expectancy. Oxidative stress is an important feature of SCD and plays a significant role in the pathophysiology of hemolysis, vaso-occlusion and ensuing organ damage in sickle cell patients. Reactive oxygen species (ROS) and the (end-)products of their oxidative reactions are potential markers of disease severity and could be targets for antioxidant therapies. This review will summarize the role of ROS in SCD and their potential implication for SCD management. Copyright © 2011 Wiley-Liss, Inc.

  6. Non-canonical autophagy: an exception or an underestimated form of autophagy?

    Science.gov (United States)

    Scarlatti, Francesca; Maffei, Roberta; Beau, Isabelle; Ghidoni, Riccardo; Codogno, Patrice

    2008-11-01

    Macroautophagy (hereafter called autophagy) is a dynamic and evolutionarily conserved process used to sequester and degrade cytoplasm and entire organelles in a sequestering vesicle with a double membrane, known as the autophagosome, which ultimately fuses with a lysosome to degrade its autophagic cargo. Recently, we have unraveled two distinct forms of autophagy in cancer cells, which we term canonical and non-canonical autophagy. In contrast to classical or canonical autophagy, non-canonical autophagy is a process that does not require the entire set of autophagy-related (Atg) proteins in particular Beclin 1, to form the autophagosome. Non-canonical autophagy is therefore not blocked by the knockdown of Beclin 1 or of its binding partner hVps34. Moreover overexpression of Bcl-2, which is known to block canonical starvation-induced autophagy by binding to Beclin 1, is unable to reverse the non-canonical autophagy triggered by the polyphenol resveratrol in the breast cancer MCF-7 cell line. In MCF-7 cells, at least, non-canonical autophagy is involved in the caspase-independent cell death induced by resveratrol.

  7. THE ROLE OF AUTOPHAGY AND ANGIOGENESIS IN COLORECTAL CANCER

    Directory of Open Access Journals (Sweden)

    K. V. Rachkovsky

    2017-01-01

    Full Text Available The purpose of the study was a review of available data on the role of autophagy and angiogenesis in the development, progression and prognosis of colorectal cancer. Material and methods. Databases searched were Medline, Cochrane Library and Elibrary. Of 340 studies, 48 were used to write a systematic review. Results. To date, there is a variety of prognostic markers used in the study of pathogenesis, diagnosis and treatment of colorectal cancer. The review describes the molecular mechanisms of the participation of various proteins of autophagy and angiogenesis in the pathogenesis and progression of colorectal cancer, and the potential importance of their use in clinical practice is presented. Conclusion. Many of the existing markers can be used not only in assessing the prognosis, but also sensitivity to chemotherapy. However, the contradictory results of studies with respect to certain proteins require further study, validation, and subsequent introduction into practice. 

  8. The role of tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL) in mediating autophagy in myositis skeletal muscle: A potential non-immune mechanism of muscle damage

    Science.gov (United States)

    Alger, Heather M.; Raben, Nina; Pistilli, Emidio; Francia, Dwight; Rawat, Rashmi; Getnet, Derese; Ghimbovschi, Svetlana; Chen, Yi-Wen; Lundberg, Ingrid E.; Nagaraju, Kanneboyina

    2011-01-01

    Objective Multinucleated cells are relatively resistant to classical apoptosis, and the factors initiating cell-death and damage in myositis are not well defined. We hypothesized that non-immune autophagic cell death may play a role in muscle fiber damage. Recent literature indicates that tumor necrosis factor-alpha-related apoptosis inducing ligand (TRAIL) may induce both NFκB (nuclear factor kappa-light chain enhancer of activated B cells) activation and autophagic cell death in other systems. Here, we have investigated its role in cell death and pathogenesis in vitro and in vivo using myositis (human and mouse) muscle tissues. Methods Gene expression profiling indicated that expression of TRAIL and several autophagy markers was specifically upregulated in myositis muscle tissue; these results were confirmed by immunohistochemistry and immunoblotting. We also analyzed TRAIL-induced cell death (apoptosis and autophagy) and NFκB activation in vitro in cultured cells. Results TRAIL was expressed predominantly in muscle fibers of myositis, but not in biopsies from normal or other dystrophic-diseased muscle. Autophagy markers were upregulated in human and mouse models of myositis. TRAIL expression was restricted to regenerating/atrophic areas of muscle fascicles, blood vessels, and infiltrating lymphocytes. TRAIL induced NFκB activation and IκB degradation in cultured cells that are resistant to TRAIL-induced apoptosis but undergo autophagic cell death. Conclusion Our data demonstrate that TRAIL is expressed in myositis muscle and may mediate both activation of NFκB and autophagic cell death in myositis. Thus, this non-immune pathway may be an attractive target for therapeutic intervention in myositis. PMID:21769834

  9. Autophagy and bacterial clearance: a not so clear picture

    OpenAIRE

    Mostowy, Serge

    2012-01-01

    Autophagy, an intracellular degradation process highly conserved from yeast to humans, is viewed as an important defence mechanism to clear intracellular bacteria. However, recent work has shown that autophagy may have different roles during different bacterial infections that restrict bacterial replication (antibacterial autophagy), act in cell autonomous signalling (non-bacterial autophagy) or support bacterial replication (pro-bacterial autophagy). This review will focus on newfound intera...

  10. Cisplatin induces protective autophagy through activation of BECN1 in human bladder cancer cells

    Directory of Open Access Journals (Sweden)

    Lin JF

    2017-05-01

    cisplatin toward BC cells. These results indicated that cisplatin induced protective autophagy which may contribute to the development of cisplatin resistance and resulted in treatment failure. Mechanistically, upregulation of beclin-1 (BECN1 was detected in cisplatin-treated cells, and knockdown of BECN1 using shRNA attenuated cisplatin-induced autophagy and subsequently enhanced cisplatin-induced apoptosis.Conclusion: Collectively, the study results indicated that cisplatin-induced autophagy is mediated by BECN1 in BC cells. Therefore, combinative treatment using cisplatin and autophagy inhibitors could potentially overcome cisplatin resistance related to autophagy induction. Keywords: autophagy inhibition, autophagy related genes, apoptosis, cisplatin resistance, human urinary bladder urothelial carcinoma, lentiviral-based shRNA

  11. Autophagy as a Molecular Target of Flavonoids Underlying their Protective Effects in Human Disease.

    Science.gov (United States)

    Prieto-Domínguez, Nestor; Garcia-Mediavilla, Maria V; Sanchez-Campos, Sonia; Mauriz, Jose L; Gonzalez-Gallego, Javier

    2018-01-01

    Autophagy is a cellular pathway with the ability to maintain cell homeostasis through the elimination of damaged or useless cellular components, and its deregulation may initiate or aggravate different human diseases. Flavonoids, a group of plant metabolites, are able to modulate different molecular and cellular processes including autophagy. To review the effects of flavonoids on autophagy pathway in both invasive and noninvasive human diseases, focusing on the global outcomes in their progression. Moreover, the efficacy of the combination of flavonoids with drugs or other natural nontoxic compounds was also reviewed. A literature search was performed to identify and analyze peer-reviewed publications containing in vitro and in vivo studies focused on autophagy deregulation in different proliferative and non-proliferative pathologies and the potential protective effects of flavonoids. Analyzed publications indicated that imbalance between cell death and survival induced by changes in autophagy play an important role in the pathophysiology of a number of human diseases. The use of different flavonoids as autophagy modulators, alone or in combination with other molecules, might be a worthy strategy in the treatment of cancer, neurodegenerative disorders, cardiovascular diseases, hepatic diseases, leishmaniasis, influenza, gastric ulcers produced by Helicobacter pylori infection, diabetes, asthma, age-related macular degeneration or osteoporosis. Flavonoids could potentially constitute important adjuvant agents of conventional therapies in the treatment of autophagy deregulation-related diseases. Moreover, combined therapy may help to diminish the doses of those conventional treatments, leading to reduced drug-derivative side effects and to improved patients' survival. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Carbamazepine suppresses calpain-mediated autophagy impairment after ischemia/reperfusion in mouse livers

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    Kim, Jae-Sung, E-mail: Jae.Kim@surgery.ufl.edu; Wang, Jin-Hee, E-mail: jin-hee.wang@surgery.ufl.edu; Biel, Thomas G., E-mail: Thomas.Biel@surgery.ufl.edu; Kim, Do-Sung, E-mail: do-sung.kim@surgery.med.ufl.edu; Flores-Toro, Joseph A., E-mail: Joseph.Flores-Toro@surgery.ufl.edu; Vijayvargiya, Richa, E-mail: rvijayvargiya@ufl.edu; Zendejas, Ivan, E-mail: ivan.zendejas@surgery.ufl.edu; Behrns, Kevin E., E-mail: Kevin.Behrns@surgery.ufl.edu

    2013-12-15

    Onset of the mitochondrial permeability transition (MPT) plays a causative role in ischemia/reperfusion (I/R) injury. Current therapeutic strategies for reducing reperfusion injury remain disappointing. Autophagy is a lysosome-mediated, catabolic process that timely eliminates abnormal or damaged cellular constituents and organelles such as dysfunctional mitochondria. I/R induces calcium overloading and calpain activation, leading to degradation of key autophagy-related proteins (Atg). Carbamazepine (CBZ), an FDA-approved anticonvulsant drug, has recently been reported to increase autophagy. We investigated the effects of CBZ on hepatic I/R injury. Hepatocytes and livers from male C57BL/6 mice were subjected to simulated in vitro, as well as in vivo I/R, respectively. Cell death, intracellular calcium, calpain activity, changes in autophagy-related proteins (Atg), autophagic flux, MPT and mitochondrial membrane potential after I/R were analyzed in the presence and absence of 20 μM CBZ. CBZ significantly increased hepatocyte viability after reperfusion. Confocal microscopy revealed that CBZ prevented calcium overloading, the onset of the MPT and mitochondrial depolarization. Immunoblotting and fluorometric analysis showed that CBZ blocked calpain activation, depletion of Atg7 and Beclin-1 and loss of autophagic flux after reperfusion. Intravital multiphoton imaging of anesthetized mice demonstrated that CBZ substantially reversed autophagic defects and mitochondrial dysfunction after I/R in vivo. In conclusion, CBZ prevents calcium overloading and calpain activation, which, in turn, suppresses Atg7 and Beclin-1 depletion, defective autophagy, onset of the MPT and cell death after I/R. - Highlights: • A mechanism of carbamazepine (CBZ)-induced cytoprotection in livers is proposed. • Impaired autophagy is a key event contributing to lethal reperfusion injury. • The importance of autophagy is extended and confirmed in an in vivo model. • CBZ is a potential

  13. Inhibition of mitochondria- and endoplasmic reticulum stress-mediated autophagy augments temozolomide-induced apoptosis in glioma cells.

    Directory of Open Access Journals (Sweden)

    Chien-Ju Lin

    Full Text Available Autophagy is a crucial process for cells to maintain homeostasis and survival through degradation of cellular proteins and organelles, including mitochondria and endoplasmic reticula (ER. We previously demonstrated that temozolomide (TMZ, an alkylating agent for brain tumor chemotherapy, induced reactive oxygen species (ROS/extracellular signal-regulated kinase (ERK-mediated autophagy to protect glioma cells from apoptosis. In this study, we investigated the role of mitochondrial damage and ER stress in TMZ-induced cytotoxicity. Mitochondrial depolarization and mitochondrial permeability transition pore (MPTP opening were observed as a prelude to TMZ-induced autophagy, and these were followed by the loss of mitochondrial mass. Electron transport chain (ETC inhibitors, such as rotenone (a complex I inhibitor, sodium azide (a complex IV inhibitor, and oligomycin (a complex V inhibitor, or the MPTP inhibitor, cyclosporine A, decreased mitochondrial damage-mediated autophagy, and therefore increased TMZ-induced apoptosis. TMZ treatment triggered ER stress with increased expression of GADD153 and GRP78 proteins, and deceased pro-caspase 12 protein. ER stress consequently induced autophagy through c-Jun N-terminal kinases (JNK and Ca(2+ signaling pathways. Combination of TMZ with 4-phenylbutyrate (4-PBA, an ER stress inhibitor, augmented TMZ-induced cytotoxicity by inhibiting autophagy. Taken together, our data indicate that TMZ induced autophagy through mitochondrial damage- and ER stress-dependent mechanisms to protect glioma cells. This study provides evidence that agents targeting mitochondria or ER may be potential anticancer strategies.

  14. A Biological Security Motivation System for Potential Threats: Are There Implications for Policy-Making?

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    Erik Z Woody

    2013-09-01

    Full Text Available Research indicates that there is a specially adapted, hard-wired brain circuit, the security motivation system, which evolved to manage potential threats, such as the possibility of contamination or predation. The existence of this system may have important implications for policy-making related to security. The system is sensitive to partial, uncertain cues of potential danger, detection of which activates a persistent, potent motivational state of wariness or anxiety. This state motivates behaviours to probe the potential danger, such as checking, and to correct for it, such as washing. Engagement in these behaviours serves as the terminating feedback for the activation of the system. Because security motivation theory makes predictions about what kinds of stimuli activate security motivation and what conditions terminate it, the theory may have applications both in understanding how policy-makers can best influence others, such as the public, and also in understanding the behavior of policy-makers themselves.

  15. Autophagy, Innate Immunity and Tissue Repair in Acute Kidney Injury

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    Pu Duann

    2016-05-01

    Full Text Available Kidney is a vital organ with high energy demands to actively maintain plasma hemodynamics, electrolytes and water homeostasis. Among the nephron segments, the renal tubular epithelium is endowed with high mitochondria density for their function in active transport. Acute kidney injury (AKI is an important clinical syndrome and a global public health issue with high mortality rate and socioeconomic burden due to lack of effective therapy. AKI results in acute cell death and necrosis of renal tubule epithelial cells accompanied with leakage of tubular fluid and inflammation. The inflammatory immune response triggered by the tubular cell death, mitochondrial damage, associative oxidative stress, and the release of many tissue damage factors have been identified as key elements driving the pathophysiology of AKI. Autophagy, the cellular mechanism that removes damaged organelles via lysosome-mediated degradation, had been proposed to be renoprotective. An in-depth understanding of the intricate interplay between autophagy and innate immune response, and their roles in AKI pathology could lead to novel therapies in AKI. This review addresses the current pathophysiology of AKI in aspects of mitochondrial dysfunction, innate immunity, and molecular mechanisms of autophagy. Recent advances in renal tissue regeneration and potential therapeutic interventions are also discussed.

  16. Macrophage migration inhibitory factor induces vascular leakage via autophagy

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    Hong-Ru Chen

    2015-01-01

    Full Text Available Vascular leakage is an important feature of acute inflammatory shock, which currently has no effective treatment. Macrophage migration inhibitory factor (MIF is a pro-inflammatory cytokine that can induce vascular leakage and plays an important role in the pathogenesis of shock. However, the mechanism of MIF-induced vascular leakage is still unclear. In this study, using recombinant MIF (rMIF, we demonstrated that MIF induced disorganization and degradation of junction proteins and increased the permeability of human endothelial cells in vitro. Western blotting analysis showed that rMIF treatment induced LC3 conversion and p62 degradation. Inhibition of autophagy with a PI3K inhibitor (3-MA, a ROS scavenger (NAC or autophagosomal-lysosomal fusion inhibitors (bafilomycin A1 and chloroquine rescued rMIF-induced vascular leakage, suggesting that autophagy mediates MIF-induced vascular leakage. The potential involvement of other signaling pathways was also studied using different inhibitors, and the results suggested that MIF-induced vascular leakage may occur through the ERK pathway. In conclusion, we showed that MIF triggered autophagic degradation of endothelial cells, resulting in vascular leakage. Inhibition of MIF-induced autophagy may provide therapeutic targets against vascular leakage in inflammatory shock.

  17. Parkinson disease: a role for autophagy?

    Science.gov (United States)

    Yang, Qian; Mao, Zixu

    2010-08-01

    Autophagy is a term used to describe the process by which lysosomes degrade intracellular components. Known originally as an adaptive response to nutrient deprivation, autophagy has now been recognized to play important roles in several human disorders including neurodegenerative diseases. Experimental results from genetic, cellular, and toxicological studies indicate that many of the etiological factors associated with Parkinson disease (PD) can perturb the autophagic process in various model systems. Thus, the emerging data support the view that dysregulation of autophagy may play a critical role in the pathogenic process of PD.

  18. The dual role of autophagy under hypoxia-involvement of interaction between autophagy and apoptosis.

    Science.gov (United States)

    Li, Mengmeng; Tan, Jin; Miao, Yuyang; Lei, Ping; Zhang, Qiang

    2015-06-01

    Hypoxia is one of severe cellular stress and it is well known to be associated with a worse outcome since a lack of oxygen accelerates the induction of apoptosis. Autophagy, an important and evolutionarily conserved mechanism for maintaining cellular homeostasis, is closely related to the apoptosis caused by hypoxia. Generally autophagy blocks the induction of apoptosis and inhibits the activation of apoptosis-associated caspase which could reduce cellular injury. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis, which could aggravate cell damage under hypoxia condition. In addition, the activation of apoptosis-related proteins-caspase can also degrade autophagy-related proteins, such as Atg3, Atg4, Beclin1 protein, inhibiting autophagy. Although the relationship between autophagy and apoptosis has been known for rather complex for more than a decade, the underlying regulatory mechanisms have not been clearly understood. This short review discusses and summarizes the dual role of autophagy and the interaction and molecular regulatory mechanisms between autophagy and apoptosis under hypoxia.

  19. Beclin1-induced autophagy abrogates radioresistance of lung cancer cells by suppressing osteopontin

    International Nuclear Information System (INIS)

    Chang, Seung-Hee; Minai-Tehrani, Arash; Shin, Ji-Young

    2012-01-01

    Osteopontin (OPN) serves as an indicator of resistance to radiotherapy. However, the role of OPN in the development of acquired radioresistance in human lung cancer cells has not yet been fully elucidated. Therefore, the potential importance of OPN as a marker of lung cancer with a potential significant role in the development of radioresistance against repeated radiotherapy has prompted us to define the pathways by which OPN regulates lung cancer cell growth. In addition, autophagy has been reported to play a key role in the radiosensitization of cancer cells. Here, we report that increased OPN expression through induction of nuclear p53 following irradiation was inhibited by exogenous beclin-1 (BECN1). Our results clearly show that BECN1 gene expression led to induction of autophagy and inhibition of cancer cell growth and angiogenesis. Our results suggest that the induction of autophagy abrogated the radioresistance of the cancer cells. Interestingly, we showed that knockdown of OPN by lentivirus-mediated shRNA induced the autophagy of human lung cancer cell. Taken together, these results suggest that OPN and BECN1 can be molecular targets for overcoming radioresistance by controlling autophagy. (author)

  20. Short-chain fatty acids induced autophagy serves as an adaptive strategy for retarding mitochondria-mediated apoptotic cell death

    OpenAIRE

    Tang, Y; Chen, Y; Jiang, H; Nie, D

    2010-01-01

    Short-chain fatty acids (SCFAs) are the major by-products of bacterial fermentation of undigested dietary fibers in the large intestine. SCFAs, mostly propionate and butyrate, inhibit proliferation and induce apoptosis in colon cancer cells, but clinical trials had mixed results regarding the anti-tumor activities of SCFAs. Herein we demonstrate that propionate and butyrate induced autophagy in human colon cancer cells to dampen apoptosis whereas inhibition of autophagy potentiated SCFA induc...

  1. Structural transitions in conserved, ordered Beclin 1 domains essential to regulating autophagy

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    Glover, Karen; Li, Yue; Mukhopadhyay, Shreya; Leuthner, Zoe; Chakravarthy, Srinivas; Colbert, Christopher L.; Sinha, Sangita C. (NDSU); (IIT)

    2017-08-10

    Beclin 1 (BECN1) is a key regulator of autophagy, a critical catabolic homeostasis pathway that involves sequestration of selected cytoplasmic components by multilayered vesicles called autophagosomes, followed by lysosomal fusion and degradation. BECN1 is a core component of class III phosphatidylinositol-3-kinase complexes responsible for autophagosome nucleation. Without heterologous binding partners, BECN1 forms an antiparallel homodimer via its coiled-coil domain (CCD). However, the last 16 CCD residues, composing an “overlap helix” (OH), have been crystallized in two mutually exclusive states: either as part of the CCD or packed against the C-terminal β-α repeated, autophagy-specific domain (BARAD). Here, using CD spectroscopy, isothermal titration calorimetry, and small-angle X-ray scattering, we show that in the homodimeric state, the OH transitions between these two different packing states, with the predominant state comprising the OH packed against the BARAD, contrary to expectations based on known BECN1 interactions with heterologous partners. We confirmed this observation by comparing the impact of mutating four residues that mediate packing of the OH against both the CCD and BARAD on structure and stability of the CCD, the OH+BARAD, and the two-domain CCD–BARAD. Last, we used cellular assays to demonstrate that mutation of these OH-interface residues abrogates starvation-induced up-regulation of autophagy but does not affect basal autophagy. In summary, we have identified a BECN1 helical region that transitions between packing as part of either one of two conserved domains (i.e. the CCD or the BARAD). Our findings have important implications for the relative stability of autophagy-inactive and autophagy-active BECN1 complexes.

  2. Structural instability of sheath potential distribution and its possible implications for the L/H transition in tokamak plasmas

    International Nuclear Information System (INIS)

    Yoshida, Zensho; Yamada, Hiroshi.

    1988-07-01

    The Bohm equation of electrostatic potential distributions in one-dimensional plasmas has been studied for various Mach numbers and plasma potentials. Solvability and structural stability have been discussed using the Sagdeev potential. Implications of the structural stability for the L/H transitions in tokamak plasmas has been also discussed. (author)

  3. Intersection of autophagy with pathways of antigen presentation.

    Science.gov (United States)

    Patterson, Natalie L; Mintern, Justine D

    2012-12-01

    Traditionally, macroautophagy (autophagy) is viewed as a pathway of cell survival. Autophagy ensures the elimination of damaged or unwanted cytosolic components and provides a source of cellular nutrients during periods of stress. Interestingly, autophagy can also directly intersect with, and impact, other major pathways of cellular function. Here, we will review the contribution of autophagy to pathways of antigen presentation. The autophagy machinery acts to modulate both MHCI and MHCII antigen presentation. As such autophagy is an important participant in pathways that elicit host cell immunity and the elimination of infectious pathogens.

  4. Autophagy: More Than a Nonselective Pathway

    Directory of Open Access Journals (Sweden)

    Fulvio Reggiori

    2012-01-01

    Full Text Available Autophagy is a catabolic pathway conserved among eukaryotes that allows cells to rapidly eliminate large unwanted structures such as aberrant protein aggregates, superfluous or damaged organelles, and invading pathogens. The hallmark of this transport pathway is the sequestration of the cargoes that have to be degraded in the lysosomes by double-membrane vesicles called autophagosomes. The key actors mediating the biogenesis of these carriers are the autophagy-related genes (ATGs. For a long time, it was assumed that autophagy is a bulk process. Recent studies, however, have highlighted the capacity of this pathway to exclusively eliminate specific structures and thus better fulfil the catabolic necessities of the cell. We are just starting to unveil the regulation and mechanism of these selective types of autophagy, but what it is already clearly emerging is that structures targeted to destruction are accurately enwrapped by autophagosomes through the action of specific receptors and adaptors. In this paper, we will briefly discuss the impact that the selective types of autophagy have had on our understanding of autophagy.

  5. Kinases Involved in Both Autophagy and Mitosis.

    Science.gov (United States)

    Li, Zhiyuan; Zhang, Xin

    2017-08-31

    Both mitosis and autophagy are highly regulated dynamic cellular processes and involve various phosphorylation events catalysed by kinases, which play vital roles in almost all physiological and pathological conditions. Mitosis is a key event during the cell cycle, in which the cell divides into two daughter cells. Autophagy is a process in which the cell digests its own cellular contents. Although autophagy regulation has mainly been studied in asynchronous cells, increasing evidence indicates that autophagy is in fact tightly regulated in mitosis. Here in this review, we will discuss kinases that were originally identified to be involved in only one of either mitosis or autophagy, but were later found to participate in both processes, such as CDKs (cyclin-dependent kinases), Aurora kinases, PLK-1 (polo-like kinase 1), BUB1 (budding uninhibited by benzimidazoles 1), MAPKs (mitogen-activated protein kinases), mTORC1 (mechanistic target of rapamycin complex 1), AMPK (AMP-activated protein kinase), PI3K (phosphoinositide-3 kinase) and protein kinase B (AKT). By focusing on kinases involved in both autophagy and mitosis, we will get a more comprehensive understanding about the reciprocal regulation between the two key cellular events, which will also shed light on their related therapeutic investigations.

  6. Kinases Involved in Both Autophagy and Mitosis

    Directory of Open Access Journals (Sweden)

    Zhiyuan Li

    2017-08-01

    Full Text Available Both mitosis and autophagy are highly regulated dynamic cellular processes and involve various phosphorylation events catalysed by kinases, which play vital roles in almost all physiological and pathological conditions. Mitosis is a key event during the cell cycle, in which the cell divides into two daughter cells. Autophagy is a process in which the cell digests its own cellular contents. Although autophagy regulation has mainly been studied in asynchronous cells, increasing evidence indicates that autophagy is in fact tightly regulated in mitosis. Here in this review, we will discuss kinases that were originally identified to be involved in only one of either mitosis or autophagy, but were later found to participate in both processes, such as CDKs (cyclin-dependent kinases, Aurora kinases, PLK-1 (polo-like kinase 1, BUB1 (budding uninhibited by benzimidazoles 1, MAPKs (mitogen-activated protein kinases, mTORC1 (mechanistic target of rapamycin complex 1, AMPK (AMP-activated protein kinase, PI3K (phosphoinositide-3 kinase and protein kinase B (AKT. By focusing on kinases involved in both autophagy and mitosis, we will get a more comprehensive understanding about the reciprocal regulation between the two key cellular events, which will also shed light on their related therapeutic investigations.

  7. Exogenous hydrogen sulfide promotes cell proliferation and differentiation by modulating autophagy in human keratinocytes

    International Nuclear Information System (INIS)

    Xie, Xin; Dai, Hui; Zhuang, Binyu; Chai, Li; Xie, Yanguang; Li, Yuzhen

    2016-01-01

    The effects and the underlying mechanisms of hydrogen sulfide (H 2 S) on keratinocyte proliferation and differentiation are still less known. In the current study, we investigated the effects and the underlying mechanisms of exogenous H 2 S on keratinocyte proliferation and differentiation. Human keratinocytes (HaCaT cells) were treated with various concentrations (0.05, 0.25, 0.5 and 1 mM) of sodium hydrosulfide (NaHS, a donor of H 2 S) for 24 h. A CCK-8 assay was used to assess cell viability. Western blot analysis was performed to determine the expression levels of proteins associated with differentiation and autophagy. Transmission electron microscopy was performed to observe autophagic vacuoles, and flow cytometry was applied to evaluate apoptosis. NaHS promoted the viability, induced the differentiation, and enhanced autophagic activity in a dose-dependent manner in HaCaT cells but had no effect on cell apoptosis. Blockage of autophagy by ATG5 siRNA inhibited NaHS-induced cell proliferation and differentiation. The current study demonstrated that autophagy in response to exogenous H 2 S treatment promoted keratinocyte proliferation and differentiation. Our results provide additional insights into the potential role of autophagy in keratinocyte proliferation and differentiation. - Highlights: • Exogenous H 2 S promotes keratinocyte proliferation and differentiation. • The effects of H 2 S on proliferation and differentiation is modulated by autophagy. • Exogenous H 2 S has no effect on keratinocyte apoptosis.

  8. Role of ROS-mediated autophagy in radiation-induced bystander effect of hepatoma cells.

    Science.gov (United States)

    Wang, Xiangdong; Zhang, Jianghong; Fu, Jiamei; Wang, Juan; Ye, Shuang; Liu, Weili; Shao, Chunlin

    2015-05-01

    Autophagy plays a crucial role in cellular response to ionizing radiation, but it is unclear whether autophagy can modulate radiation-induced bystander effect (RIBE). Here, we investigated the relationship between bystander damage and autophagy in human hepatoma cells of HepG2. HepG2 cells were treated with conditioned medium (CM) collected from 3 Gy γ-rays irradiated hepatoma HepG2 cells for 4, 12, or 24 h, followed by the measurement of micronuclei (MN), intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and protein expressions of microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 in the bystander HepG2 cells. In some experiments, the bystander HepG2 cells were respectively transfected with LC3 small interfering RNA (siRNA), Beclin-1 siRNA or treated with 1% dimethyl sulfoxide (DMSO). Additional MN and mitochondrial dysfunction coupled with ROS were induced in the bystander cells. The expressions of protein markers of autophagy, LC3-II/LC3-I and Beclin-1, increased in the bystander cells. The inductions of bystander MN and overexpressions of LC3 and Beclin-1 were significantly diminished by DMSO. However, when the bystander cells were transfected with LC3 siRNA or Beclin-1 siRNA, the yield of bystander MN was significantly enhanced. The elevated ROS have bi-functions in balancing the bystander effects. One is to cause MN and the other is to induce protective autophagy.

  9. Carnosol induces ROS-mediated beclin1-independent autophagy and apoptosis in triple negative breast cancer.

    Directory of Open Access Journals (Sweden)

    Yusra Al Dhaheri

    Full Text Available In this study we investigated the in vitro and in vivo anticancer effect of carnosol, a naturally occurring polyphenol, in triple negative breast cancer.We found that carnosol significantly inhibited the viability and colony growth induced G2 arrest in the triple negative MDA-MB-231. Blockade of the cell cycle was associated with increased p21/WAF1 expression and downregulation of p27. Interestingly, carnosol was found to induce beclin1-independent autophagy and apoptosis in MDA-MB-231 cells. The coexistence of both events, autophagy and apoptosis, was confirmed by electron micrography. Induction of autophagy was found to be an early event, detected within 3 h post-treatment, which subsequently led to apoptosis. Carnosol treatment also caused a dose-dependent increase in the levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2. Moreover, we show that carnosol induced DNA damage, reduced the mitochondrial potential and triggered the activation of the intrinsic and extrinsic apoptotic pathway. Furthermore, we found that carnosol induced a dose-dependent generation of reactive oxygen species (ROS and inhibition of ROS by tiron, a ROS scavenger, blocked the induction of autophagy and apoptosis and attenuated DNA damage. To our knowledge, this is the first report to identify the induction of autophagy by carnosol.In conclusion our findings provide strong evidence that carnosol may be an alternative therapeutic candidate against the aggressive form of breast cancer and hence deserves more exploration.

  10. Autophagy protects against neural cell death induced by piperidine alkaloids present in Prosopis juliflora (Mesquite).

    Science.gov (United States)

    Silva, Victor D A; Cuevas, Carlos; Muñoz, Patricia; Villa, Monica; Ahumada-Castro, Ulises; Huenchuguala, Sandro; Santos, Cleonice C Dos; Araujo, Fillipe M DE; Ferreira, Rafael S; Silva, Vanessa B DA; Silva, Juliana H C E; Soares, Érica N; Velozo, Eudes S; Segura-Aguilar, Juan; Costa, Silvia L

    2017-01-01

    Prosopis juliflora is a shrub that has been used to feed animals and humans. However, a synergistic action of piperidine alkaloids has been suggested to be responsible for neurotoxic damage observed in animals. We investigated the involvement of programmed cell death (PCD) and autophagy on the mechanism of cell death induced by a total extract (TAE) of alkaloids and fraction (F32) from P. juliflora leaves composed majoritary of juliprosopine in a model of neuron/glial cell co-culture. We saw that TAE (30 µg/mL) and F32 (7.5 µg/mL) induced reduction in ATP levels and changes in mitochondrial membrane potential at 12 h exposure. Moreover, TAE and F32 induced caspase-9 activation, nuclear condensation and neuronal death at 16 h exposure. After 4 h, they induced autophagy characterized by decreases of P62 protein level, increase of LC3II expression and increase in number of GFP-LC3 cells. Interestingly, we demonstrated that inhibition of autophagy by bafilomycin and vinblastine increased the cell death induced by TAE and autophagy induced by serum deprivation and rapamycin reduced cell death induced by F32 at 24 h. These results indicate that the mechanism neural cell death induced by these alkaloids involves PCD via caspase-9 activation and autophagy, which seems to be an important protective mechanism.

  11. Autophagy protects against neural cell death induced by piperidine alkaloids present in Prosopis juliflora (Mesquite

    Directory of Open Access Journals (Sweden)

    VICTOR D.A. SILVA

    Full Text Available ABSTRACT Prosopis juliflora is a shrub that has been used to feed animals and humans. However, a synergistic action of piperidine alkaloids has been suggested to be responsible for neurotoxic damage observed in animals. We investigated the involvement of programmed cell death (PCD and autophagy on the mechanism of cell death induced by a total extract (TAE of alkaloids and fraction (F32 from P. juliflora leaves composed majoritary of juliprosopine in a model of neuron/glial cell co-culture. We saw that TAE (30 µg/mL and F32 (7.5 µg/mL induced reduction in ATP levels and changes in mitochondrial membrane potential at 12 h exposure. Moreover, TAE and F32 induced caspase-9 activation, nuclear condensation and neuronal death at 16 h exposure. After 4 h, they induced autophagy characterized by decreases of P62 protein level, increase of LC3II expression and increase in number of GFP-LC3 cells. Interestingly, we demonstrated that inhibition of autophagy by bafilomycin and vinblastine increased the cell death induced by TAE and autophagy induced by serum deprivation and rapamycin reduced cell death induced by F32 at 24 h. These results indicate that the mechanism neural cell death induced by these alkaloids involves PCD via caspase-9 activation and autophagy, which seems to be an important protective mechanism.

  12. Agent-based modeling of autophagy reveals emergent regulatory behavior of spatio-temporal autophagy dynamics.

    Science.gov (United States)

    Börlin, Christoph S; Lang, Verena; Hamacher-Brady, Anne; Brady, Nathan R

    2014-09-10

    Autophagy is a vesicle-mediated pathway for lysosomal degradation, essential under basal and stressed conditions. Various cellular components, including specific proteins, protein aggregates, organelles and intracellular pathogens, are targets for autophagic degradation. Thereby, autophagy controls numerous vital physiological and pathophysiological functions, including cell signaling, differentiation, turnover of cellular components and pathogen defense. Moreover, autophagy enables the cell to recycle cellular components to metabolic substrates, thereby permitting prolonged survival under low nutrient conditions. Due to the multi-faceted roles for autophagy in maintaining cellular and organismal homeostasis and responding to diverse stresses, malfunction of autophagy contributes to both chronic and acute pathologies. We applied a systems biology approach to improve the understanding of this complex cellular process of autophagy. All autophagy pathway vesicle activities, i.e. creation, movement, fusion and degradation, are highly dynamic, temporally and spatially, and under various forms of regulation. We therefore developed an agent-based model (ABM) to represent individual components of the autophagy pathway, subcellular vesicle dynamics and metabolic feedback with the cellular environment, thereby providing a framework to investigate spatio-temporal aspects of autophagy regulation and dynamic behavior. The rules defining our ABM were derived from literature and from high-resolution images of autophagy markers under basal and activated conditions. Key model parameters were fit with an iterative method using a genetic algorithm and a predefined fitness function. From this approach, we found that accurate prediction of spatio-temporal behavior required increasing model complexity by implementing functional integration of autophagy with the cellular nutrient state. The resulting model is able to reproduce short-term autophagic flux measurements (up to 3

  13. Apoptosis and autophagy induced by pyropheophorbide-α methyl ester-mediated photodynamic therapy in human osteosarcoma MG-63 cells.

    Science.gov (United States)

    Huang, Qiu; Ou, Yun-Sheng; Tao, Yong; Yin, Hang; Tu, Ping-Hua

    2016-06-01

    Pyropheophorbide-α methyl ester (MPPa) was a second-generation photosensitizer with many potential applications. Here, we explored the impact of MPPa-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and autophagy of human osteosarcoma (MG-63) cells as well as the relationships between apoptosis and autophagy of the cells, and investigated the related molecular mechanisms. We found that MPPa-PDT demonstrated the ability to inhibit MG-63 cell viability in an MPPa concentration- and light dose-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, MPPa-PDT could also induce autophagy of MG-63 cell. Meanwhile, the ROS scavenger N-acetyl-L-cysteine (NAC) and the Jnk inhibitor SP600125 were found to inhibit the MPPa-PDT-induced autophagy, and NAC could also inhibit Jnk phosphorylation. Furthermore, pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine showed the potential in reducing the apoptosis rate induced by MPPa-PDT in MG-63 cells. Our results indicated that the mitochondrial pathway was involved in MPPa-PDT-induced apoptosis of MG-63 cells. Meanwhile the ROS-Jnk signaling pathway was involved in MPPa-PDT-induced autophagy, which further promoted the apoptosis in MG-63 cells.

  14. A hybrid of coumarin and phenylsulfonylfuroxan induces caspase-dependent apoptosis and cytoprotective autophagy in lung adenocarcinoma cells.

    Science.gov (United States)

    Wang, Qian; Guo, Yalan; Jiang, Shanshan; Dong, Mengxue; Kuerban, Kudelaidi; Li, Jiyang; Feng, Meiqing; Chen, Ying; Ye, Li

    2018-01-15

    Lung adenocarcinoma is the most primary histologic subtype of non-small cell lung cancer (NSCLC). Compound 8b, a novel coumarin derivative with phenylsulfonylfuroxan group, shows significant antiproliferation activity against lung adenocarcinoma cell with low toxicity. This study aims to uncover the potential of compound 8b in relation to apoptosis as well as autophagy induction in lung adenocarcinoma cells. The cytotoxicity and apoptosis of A549 and H1299 cells induced by compound 8b were detected by MTT, microscope and western blot analysis. Autophagy was determined by TEM, confocal microscopy and western blot analysis. Akt/mTOR and Erk signaling pathway were also examined by western blot analysis. First, significant growth inhibition and caspase-dependent apoptosis were observed in compound 8b-treated A549 and H1299 cells. Then, we confirmed compound 8b-induced autophagy by autophagosomes formation, upregulated expression of autophagy-related protein LC3-II and autophagic flux. Importantly, abolishing autophagy using inhibitors and ATG5 siRNA enhanced the cytotoxicity of compound 8b, indicating the cytoprotective role of autophagy in lung adenocarcinoma. Further mechanistic investigations suggested that Akt/mTOR and Erk signaling pathways contributed to autophagy induction by compound 8b. This results demonstrate that compound 8b induces caspase-dependent apoptosis as well as cytoprotective autophagy in lung adenocarcinoma cells, which may provide scientific evidence for developing this furoxan-based NO-releasing coumarin derivative as a potential anti-lung adenocarcinoma therapeutic agents. Copyright © 2017 Elsevier GmbH. All rights reserved.

  15. Concurrent Autophagy Inhibition Overcomes the Resistance of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Human Bladder Cancer Cells.

    Science.gov (United States)

    Kang, Minyong; Lee, Kyoung-Hwa; Lee, Hye Sun; Jeong, Chang Wook; Kwak, Cheol; Kim, Hyeon Hoe; Ku, Ja Hyeon

    2017-02-04

    Despite the potential therapeutic efficacy of epithelial growth factor receptor (EGFR) inhibitors in the treatment of advanced stage bladder cancer, there currently is no clear evidence to support this hypothesis. In this study, we investigate whether the concurrent treatment of autophagy-blocking agents with EGFR inhibitors exerts synergistic anti-cancer effects in T24 and J82 human bladder cancer cells. Lapatinib and gefitinib were used as EGFR inhibitors, and bafilomycin A1 (BFA1), chloroquine (CQ) and 3-methyladenine (3-MA) were used as the pharmacologic inhibitors of autophagy activities. To assess the proliferative and self-renewal capabilities, the Cell Counting Kit-8 (CCK-8) assay and a clonogenic assay were performed, respectively. To examine apoptotic cell death, flow cytometry using annexin-V/propidium iodide (PI) was used. To measure the autophagy activities, the expression levels of LC3I and II was determined by Western blot analysis. To validate the synergistic effects of autophagy inhibition with EGFR inhibitors, we specifically blocked key autophagy regulatory gene ATG12 by transfection of small interference RNA and examined the phenotypic changes. Of note, lapatinib and gefitinib triggered autophagy activities in T24 and J82 human bladder cancer cells, as indicated by upregulation of LC3II. More importantly, inhibiting autophagy activities with pharmacologic inhibitors (BFA1, CQ or 3-MA) remarkably reduced the cell viabilities and clonal proliferation of T24 and J82 cells, compared to those treated with either of the agents alone. We also obtained similar results of the enhanced anti-cancer effects of EGFR inhibitors by suppressing the expression of ATG12. Notably, the apoptotic assay showed that synergistic anti-cancer effects were induced via the increase of apoptotic cell death. In summary, concomitant inhibition of autophagy activities potentiated the anti-cancer effects of EGFR inhibitors in human bladder cancer cells, indicating a novel

  16. Concurrent Autophagy Inhibition Overcomes the Resistance of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Human Bladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Minyong Kang

    2017-02-01

    Full Text Available Despite the potential therapeutic efficacy of epithelial growth factor receptor (EGFR inhibitors in the treatment of advanced stage bladder cancer, there currently is no clear evidence to support this hypothesis. In this study, we investigate whether the concurrent treatment of autophagy-blocking agents with EGFR inhibitors exerts synergistic anti-cancer effects in T24 and J82 human bladder cancer cells. Lapatinib and gefitinib were used as EGFR inhibitors, and bafilomycin A1 (BFA1, chloroquine (CQ and 3-methyladenine (3-MA were used as the pharmacologic inhibitors of autophagy activities. To assess the proliferative and self-renewal capabilities, the Cell Counting Kit-8 (CCK-8 assay and a clonogenic assay were performed, respectively. To examine apoptotic cell death, flow cytometry using annexin-V/propidium iodide (PI was used. To measure the autophagy activities, the expression levels of LC3I and II was determined by Western blot analysis. To validate the synergistic effects of autophagy inhibition with EGFR inhibitors, we specifically blocked key autophagy regulatory gene ATG12 by transfection of small interference RNA and examined the phenotypic changes. Of note, lapatinib and gefitinib triggered autophagy activities in T24 and J82 human bladder cancer cells, as indicated by upregulation of LC3II. More importantly, inhibiting autophagy activities with pharmacologic inhibitors (BFA1, CQ or 3-MA remarkably reduced the cell viabilities and clonal proliferation of T24 and J82 cells, compared to those treated with either of the agents alone. We also obtained similar results of the enhanced anti-cancer effects of EGFR inhibitors by suppressing the expression of ATG12. Notably, the apoptotic assay showed that synergistic anti-cancer effects were induced via the increase of apoptotic cell death. In summary, concomitant inhibition of autophagy activities potentiated the anti-cancer effects of EGFR inhibitors in human bladder cancer cells, indicating

  17. The role of kaempferol-induced autophagy on differentiation and mineralization of osteoblastic MC3T3-E1 cells.

    Science.gov (United States)

    Kim, In-Ryoung; Kim, Seong-Eon; Baek, Hyun-Su; Kim, Bok-Joo; Kim, Chul-Hoon; Chung, In-Kyo; Park, Bong-Soo; Shin, Sang-Hun

    2016-08-31

    Kaempferol, a kind of flavonol, has been reported to possess various osteogenic biological activities, such as inhibiting bone resorption of osteoclasts and promoting the differentiation and mineralization of preosteoblasts. However, the precise cellular mechanism of action of kaempferol in osteogenesis is elusive. Autophagy is a major intracellular degradation system, which plays an important role in cell growth, survival, differentiation and homeostasis in mammals. Recent studies showed that autophagy appeared to be involved in the degradation of osteoclasts, osteoblasts and osteocytes, potentially pointing to a new pathogenic mechanism of bone homeostasis and bone marrow disease. The potential correlation between autophagy, osteogenesis and flavonoids is unclear. The present study verified that kaempferol promoted osteogenic differentiation and mineralization and that it elevated osteogenic gene expression based on alkaline phosphatase (ALP) activity, alizarin red staining and quantitative PCR. And then we found that kaempferol induced autophagy by acridine orange (AO) and monodansylcadaverine (MDC) staining and autophagy-related protein expression. The correlation between kaempferol-induced autophagy and the osteogenic process was confirmed by the autophagy inhibitor 3-methyladenine (3-MA). Kaempferol promoted the proliferation, differentiation and mineralization of osteoblasts at a concentration of 10 μM. Kaempferol showed cytotoxic properties at concentrations above 50 μM. Concentrations above 10 μM decreased ALP activity, whereas those up to 10 μM increased ALP activity. Kaempferol at concentrations up to 10 μM also increased the expression of the osteoblast- activated factors RUNX-2, osterix, BMP-2 and collagen I according to RT-PCR analyses. 10 μM or less, the higher of the concentration and over time, kaempferol promoted the activity of osteoblasts. Kaempferol induced autophagy. It also increased the expression of the autophagy-related factors

  18. Predicting potential global distributions of two Miscanthus grasses: implications for horticulture, biofuel production, and biological invasions.

    Science.gov (United States)

    Hager, Heather A; Sinasac, Sarah E; Gedalof, Ze'ev; Newman, Jonathan A

    2014-01-01

    In many regions, large proportions of the naturalized and invasive non-native floras were originally introduced deliberately by humans. Pest risk assessments are now used in many jurisdictions to regulate the importation of species and usually include an estimation of the potential distribution in the import area. Two species of Asian grass (Miscanthus sacchariflorus and M. sinensis) that were originally introduced to North America as ornamental plants have since escaped cultivation. These species and their hybrid offspring are now receiving attention for large-scale production as biofuel crops in North America and elsewhere. We evaluated their potential global climate suitability for cultivation and potential invasion using the niche model CLIMEX and evaluated the models' sensitivity to the parameter values. We then compared the sensitivity of projections of future climatically suitable area under two climate models and two emissions scenarios. The models indicate that the species have been introduced to most of the potential global climatically suitable areas in the northern but not the southern hemisphere. The more narrowly distributed species (M. sacchariflorus) is more sensitive to changes in model parameters, which could have implications for modelling species of conservation concern. Climate projections indicate likely contractions in potential range in the south, but expansions in the north, particularly in introduced areas where biomass production trials are under way. Climate sensitivity analysis shows that projections differ more between the selected climate change models than between the selected emissions scenarios. Local-scale assessments are required to overlay suitable habitat with climate projections to estimate areas of cultivation potential and invasion risk.

  19. Characterization of acetate transport in colorectal cancer cells and potential therapeutic implications

    Science.gov (United States)

    Ferro, Suellen; Azevedo-Silva, João; Casal, Margarida; Côrte-Real, Manuela; Baltazar, Fatima; Preto, Ana

    2016-01-01

    Acetate, together with other short chain fatty acids has been implicated in colorectal cancer (CRC) prevention/therapy. Acetate was shown to induce apoptosis in CRC cells. The precise mechanism underlying acetate transport across CRC cells membrane, that may be implicated in its selectivity towards CRC cells, is not fully understood and was addressed here. We also assessed the effect of acetate in CRC glycolytic metabolism and explored its use in combination with the glycolytic inhibitor 3-bromopyruvate (3BP). We provide evidence that acetate enters CRC cells by the secondary active transporters MCT1 and/or MCT2 and SMCT1 as well as by facilitated diffusion via aquaporins. CRC cell exposure to acetate upregulates the expression of MCT1, MCT4 and CD147, while promoting MCT1 plasma membrane localization. We also observed that acetate increases CRC cell glycolytic phenotype and that acetate-induced apoptosis and anti-proliferative effect was potentiated by 3BP. Our data suggest that acetate selectivity towards CRC cells might be explained by the fact that aquaporins and MCTs are found overexpressed in CRC clinical cases. Our work highlights the importance that acetate transport regulation has in the use of drugs such as 3BP as a new therapeutic strategy for CRC. PMID:28874966

  20. Epicardial fat and atrial fibrillation: current evidence, potential mechanisms, clinical implications, and future directions.

    Science.gov (United States)

    Wong, Christopher X; Ganesan, Anand N; Selvanayagam, Joseph B

    2017-05-01

    Obesity is increasingly recognized as a major modifiable determinant of atrial fibrillation (AF). Although body mass index and other clinical measures are useful indications of general adiposity, much recent interest has focused on epicardial fat, a distinct adipose tissue depot that can be readily assessed using non-invasive imaging techniques. A growing body of data from epidemiological and clinical studies has demonstrated that epicardial fat is consistently associated with the presence, severity, and recurrence of AF across a range of clinical settings. Evidence from basic science and translational studies has also suggested that arrhythmogenic mechanisms may involve adipocyte infiltration, pro-fibrotic, and pro-inflammatory paracrine effects, oxidative stress, and other pathways. Despite these advances, however, significant uncertainty exists and many questions remain unanswered. In this article, we review our present understanding of epicardial fat, including its classification and quantification, existing evidence implicating its role in AF, potential mechanisms, implications for clinicians, and future directions for research. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  1. Regulation of Autophagy by Glucose in Mammalian Cells

    OpenAIRE

    Moruno, Félix; Pérez-Jiménez, Eva; Knecht, Erwin

    2012-01-01

    Autophagy is an evolutionarily conserved process that contributes to maintain cell homeostasis. Although it is strongly regulated by many extracellular factors, induction of autophagy is mainly produced by starvation of nutrients. In mammalian cells, the regulation of autophagy by amino acids, and also by the hormone insulin, has been extensively investigated, but knowledge about the effects of other autophagy regulators, including another nutrient, glucose, is more limited. Here we will focu...

  2. Sorafenib-induced defective autophagy promotes cell death by necroptosis

    OpenAIRE

    Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Bj?rklund, Ann-Charlotte; Zhivotovsky, Boris; Grand?r, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis

    2015-01-01

    Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencin...

  3. Autophagy induction contributes to GDC-0349 resistance in head and neck squamous cell carcinoma (HNSCC) cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yajuan; Peng, Yi [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China); Tang, Hao [Department of Pathology, Hubei Cancer Hospital, Wuhan 430071 (China); He, Xiaojun; Wang, Zhaohua [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China); Hu, Desheng, E-mail: hudeshengvvip@sina.com [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China); Zhou, Xiaoyi, E-mail: zhouxy1218@126.com [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China)

    2016-08-19

    Dysregulation of mammalian target of rapamycin (mTOR) signaling contributes to head and neck squamous cell carcinoma (HNSCC) tumorigenesis and progression. In the current study, we tested the anti-HNSCC cell activity by GDC-0349, a selective ATP-competitive inhibitor of mTOR. We showed that GDC-0349 inhibited proliferation of established and primary human HNSCC cells bearing high-level of p-AKT/p-S6K. Further, it induced caspase-dependent apoptosis in the HNSCC cells. GDC-0349 blocked mTORC1 and mTORC2 activation, yet it simultaneously induced autophagy activation in HNSCC cells. The latter was evidenced by induction of LC3B-II, Beclin-1 and Autophagy-related (ATG)-7, as well as downregulation of p62. Autophagy inhibitors (3-methyladenine and bafilomycin A1) or ATG-7 siRNA dramatically potentiated GDC-0349’s cytotoxicity against HNSCC cells. Intriguingly, we showed that ceramide (C14), a pro-apoptotic sphingolipid, also induced ATG-7 degradation, and sensitized HNSCC cells to GDC-0349. Collectively, the preclinical study provided evidences to support GDC-0349 as a promising anti-HNSCC agent. GDC-0349 sensitization may be achieved via autophagy inhibition. - Highlights: • GDC-0349 inhibits proliferation of HNSCC cells bearing high-level of p-AKT/p-S6K. • GDC-0349 activates caspase-dependent apoptosis in HNSCC cells. • Simultaneous blockage of mTORC1/2 by GDC-0349 induces autophagy activation. • Autophagy inhibitor or ATG-7 siRNA potentiates GDC-0349’s cytotoxicity. • C14 ceramide downregulates ATG-7 and sensitizes HNSCC cells to GDC-0349.

  4. Autophagy-associated proteins BAG3 and p62 in testicular cancer.

    Science.gov (United States)

    Bartsch, Georg; Jennewein, Lukas; Harter, Patrick N; Antonietti, Patrick; Blaheta, Roman A; Kvasnicka, Hans-Michael; Kögel, Donat; Haferkamp, Axel; Mittelbronn, Michel; Mani, Jens

    2016-03-01

    Testicular germ cell tumors (TGCT) represent the most common malignant tumor group in the age group of 20 to 40-years old men. The potentially curable effect of cytotoxic therapy in TGCT is mediated mainly by the induction of apoptosis. Autophagy has been discussed as an alternative mechanism of cell death but also of treatment resistance in various types of tumors. However, in TGCT the expression and role of core autophagy-associated factors is hitherto unknown. We designed the study in order to evaluate the potential role of autophagy-associated factors in the development and progression of testicular cancers. Eighty-four patients were assessed for autophagy (BAG3, p62) and apoptosis (cleaved caspase 3) markers using immunohistochemistry (IHC) on tissue micro- arrays. In addition, western blot analyses of frozen tissue of seminoma and non-seminoma were performed. Our findings show that BAG3 was significantly upregulated in seminoma as compared to non-seminoma but not to normal testicular tissue. No significant difference of p62 expression was detected between neoplastic and normal tissue or between seminoma and non-seminoma. BAG3 and p62 showed distinct loco‑regional expression patterns in normal and neoplastic human testicular tissues. In contrast to the autophagic markers, apoptosis rate was significantly higher in testicular tumors as compared to normal testicular tissue, but not between different TGCT subtypes. The present study, for the first time, examined the expression of central autophagy proteins BAG3 and p62 in testicular cancer. Our findings imply that in general apoptosis but not autophagy induction differs between normal and neoplastic testis tissue.

  5. Heat Shock Proteins: Pathogenic Role in Atherosclerosis and Potential Therapeutic Implications

    Directory of Open Access Journals (Sweden)

    Arman Kilic

    2012-01-01

    Full Text Available Heat shock proteins (HSPs are a highly conserved group of proteins that are constitutively expressed and function as molecular chaperones, aiding in protein folding and preventing the accumulation of misfolded proteins. In the arterial wall, HSPs have a protective role under normal physiologic conditions. In disease states, however, HSPs expressed on the vascular endothelial cell surface can act as targets for detrimental autoimmunity due to their highly conserved sequences. Developing therapeutic strategies for atherosclerosis based on HSPs is challenged by the need to balance such physiologic and pathologic roles of these proteins. This paper summarizes the role of HSPs in normal vascular wall processes as well as in the development and progression of atherosclerosis. The potential implications of HSPs in clinical therapies for atherosclerosis are also discussed.

  6. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    International Nuclear Information System (INIS)

    Sinclair, W.K.; Fry, R.J.M.

    1987-01-01

    An overview of presentations and discussions which took place at the US Department of Energy/Commission of European Communities (DOE/CEC) workshop on ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection,'' held at San Diego, California, January 21-22, 1987, is provided. The Department has traditionally supported fundamental research on interactions of ionizing radiation with different biological systems and at all levels of biological organization. The aim of this workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection

  7. Student's corner: potential implications of registered nurse attitudes towards caring for older people.

    Science.gov (United States)

    Marshall, Lynette C

    2010-01-01

    In discussing the potential implications of the attitudes of the registered nurse towards the work of caring for older people, it was helpful to highlight why this work is important, gain some understanding of quality care and how it can be facilitated or hindered. Patient centred care is essential as there is great diversity found amongst older people. It was found that attitudes held by registered nurses and students towards older people have a direct impact on the quality of care provided. Negative attitudes and stereotyping get in the way of quality care while positive attitudes enabled quality care. In identifying the factors that influence these attitudes, registered nurses can take on a leadership role in promoting positive attitudes and challenging negative attitudes towards the care of older people with the goal of providing patient centre care.

  8. Potential environmental implications of nanoscale zero-valent iron particles for environmental remediation

    Directory of Open Access Journals (Sweden)

    Min-Hee Jang

    2014-12-01

    Full Text Available Objectives Nanoscale zero-valent iron (nZVI particles are widely used in the field of various environmental contaminant remediation. Although the potential benefits of nZVI are considerable, there is a distinct need to identify any potential risks after environmental exposure. In this respect, we review recent studies on the environmental applications and implications of nZVI, highlighting research gaps and suggesting future research directions. Methods Environmental application of nZVI is briefly summarized, focusing on its unique properties. Ecotoxicity of nZVI is reviewed according to type of organism, including bacteria, terrestrial organisms, and aquatic organisms. The environmental fate and transport of nZVI are also summarized with regards to exposure scenarios. Finally, the current limitations of risk determination are thoroughly provided. Results The ecotoxicity of nZVI depends on the composition, concentration, size and surface properties of the nanoparticles and the experimental method used, including the species investigated. In addition, the environmental fate and transport of nZVI appear to be complex and depend on the exposure duration and the exposure conditions. To date, field-scale data are limited and only short-term studies using simple exposure methods have been conducted. Conclusions In this regard, the primary focus of future study should be on 1 the development of an appropriate and valid testing method of the environmental fate and ecotoxicity of reactive nanoparticles used in environmental applications and 2 assessing their potential environmental risks using in situ field scale applications.

  9. Beat-to-beat variability of cardiac action potential duration: underlying mechanism and clinical implications.

    Science.gov (United States)

    Nánási, Péter P; Magyar, János; Varró, András; Ördög, Balázs

    2017-10-01

    Beat-to-beat variability of cardiac action potential duration (short-term variability, SV) is a common feature of various cardiac preparations, including the human heart. Although it is believed to be one of the best arrhythmia predictors, the underlying mechanisms are not fully understood at present. The magnitude of SV is basically determined by the intensity of cell-to-cell coupling in multicellular preparations and by the duration of the action potential (APD). To compensate for the APD-dependent nature of SV, the concept of relative SV (RSV) has been introduced by normalizing the changes of SV to the concomitant changes in APD. RSV is reduced by I Ca , I Kr , and I Ks while increased by I Na , suggesting that ion currents involved in the negative feedback regulation of APD tend to keep RSV at a low level. RSV is also influenced by intracellular calcium concentration and tissue redox potential. The clinical implications of APD variability is discussed in detail.

  10. 'Underutilised' agricultural land: its definitions, potential use for future biomass production and its environmental implications

    Science.gov (United States)

    Miyake, Saori; Bargiel, Damian

    2017-04-01

    A growing bioeconomy and increased demand for biomass products on food, health, fibre, industrial products and energy require land resources for feedstock production. It has resulted in significant environmental and socio-economic challenges on a global scale. As a result, consideration of such effects of land use change (LUC) from biomass production (particularly for biofuel feedstock) has emerged as an important area of policy and research, and several potential solutions have been proposed to minimise such adverse LUC effects. One of these solutions is the use of lands that are not in production or not suitable for food crop production, such as 'marginal', 'degraded', 'abandoned' and 'surplus' agricultural lands for future biomass production. The terms referring to these lands are usually associated with the potential production of 'marginal crops', which can grow in marginal conditions (e.g. poor soil fertility, low rainfall, drought) without much water and agrochemical inputs. In our research, we referred to these lands as 'underutilised' agricultural land and attempted to define them for our case study areas located in Australia and Central and Eastern Europe (CEE). Our goal is to identify lands that can be used for future biomass production and to evaluate their environmental implications, particularly impacts related to biodiversity, water and soil at a landscape scale. The identification of these lands incorporates remote sensing and spatially explicit approaches. Our findings confirmed that there was no universal or single definition of the term 'underutilised' agricultural land as the definitions significantly vary by country and region depending not only on the biophysical environment but also political, institutional and socio-economic conditions. Moreover, our results highlighted that the environmental implications of production of biomass on 'underutilised' agricultural land for biomass production are highly controversial. Thus land use change

  11. Elevation of autophagy markers in Sjögren syndrome dry eye.

    Science.gov (United States)

    Byun, Yong-Soo; Lee, Hyun Jung; Shin, Soojung; Chung, So-Hyang

    2017-12-08

    Autophagy is known to be implicated in the pathogenesis of Sjögren syndrome (SS), but evidences are limited. We aimed to examine the levels of autophagy markers in tear film and conjunctival epithelial cells from SS dry eye patients, and analyze their correlations with clinical features. Patients with SS dry eye exhibited lower Schirmer values, lower tear breakup time, and higher ocular staining scores. In tears, ATG5 and LC3B-II/I levels were significantly higher in SS dry eye. ATG5 and LC3B-II mRNA in the conjunctiva were also elevated in SS dry eye compared with non-SS dry eye. The immunostaining of conjunctival epithelium showed a punctate pattern of ATG5 and LC3B-II in SS dry eye. These staining patterns were also observed in the lacrimal gland of SS animal models. ATG5 levels in tears and the conjunctival epithelium strongly correlated with ocular staining scores, and one month of topical corticosteroid treatment reduced both ATG5 and LC3B-II/I levels in tear film and the conjunctival epithelium of patients with SS dry eye. Our results suggest that autophagy is enhanced or dysregulated in SS and autophagy markers may be serve as both diagnostic and therapeutic biomarkers in SS dry eye.

  12. Potential implications for expansion of freeze-tolerant eucalyptus plantations on water resources in the southern United States

    Science.gov (United States)

    James M. Vose; Chelcy F. Miniat; Ge Sun; Peter V. Caldwell

    2014-01-01

    The potential expansion of freeze-tolerant (FT) Eucalyptus plantations in the United States has raised concerns about the implications for water resources. Modeling was used to examine the potential effects of expanding the distribution of FT Eucalyptus plantations in US Department of Agriculture Plant Hardiness Zones 8b and...

  13. Autophagy and Retromer Components in Plant Innate Immunity

    DEFF Research Database (Denmark)

    Munch, David

    -hormone salicylic acid. Here, I present data that make it clear that NPR1 does not directly regulate autophagy, but instead control stress responses that indirectly activate autophagy. The observations presented will also clarify why autophagy has been described as being both a pro-death and pro-life pathway under...

  14. Moderate mammalian target of rapamycin inhibition induces autophagy in HTR8/SVneo cells via O-linked β-N-acetylglucosamine signaling.

    Science.gov (United States)

    Zhang, Qiuxia; Na, Quan; Song, Weiwei

    2017-10-01

    Autophagy, a highly regulated process with a dual role (pro-survival or pro-death), has been implicated in adverse pregnancy outcomes. The aim of this study was to explore the mechanism whereby mammalian target of rapamycin (mTOR) signaling regulates autophagy by modulating protein O-GlcNAcylation in human trophoblasts. HTR8/SVneo cells were incubated in serum-free medium for different time intervals or treated with varying doses of Torin1. Protein expression and cell apoptosis were detected by immunoblotting and flow cytometry, respectively. Short-term serum starvation or slight suppression of mTOR signaling promoted autophagy and decreased apoptosis in HTR8/SVneo cells. Conversely, prolonged serum starvation or excessive inhibition of mTOR reduced autophagy and enhanced cell apoptosis. Both serum starvation and mTOR signaling suppression reduced protein O-GlcNAcylation. Upregulation and downregulation of O-linked β-N-acetylglucosamine (O-GlcNAc) levels attenuated and augmented autophagy, respectively. Moderate mTOR inhibition-induced autophagy was blocked by upregulation of protein O-GlcNAcylation. Furthermore, immunoprecipitation studies revealed that Beclin1 and synaptosome associated protein 29 (SNAP29) could be O-GlcNAcylated, and that slight mTOR inhibition resulted in decreased O-GlcNAc modification of Beclin1 and SNAP29. Notably, we observed an inverse correlation between phosphorylation (Ser15) and O-GlcNAcylation of Beclin1. mTOR signaling inhibition played dual roles in regulating autophagy and apoptosis in HTR8/SVneo cells. Moderate mTOR suppression might induce autophagy via modulating O-GlcNAcylation of Beclin1 and SNAP29. Moreover, the negative interplay between Beclin1 O-GlcNAcylation and phosphorylation (Ser15) may be involved in autophagy regulation by mTOR signaling. © 2017 Japan Society of Obstetrics and Gynecology.

  15. Apoptotic Cell Death Induced by Resveratrol Is Partially Mediated by the Autophagy Pathway in Human Ovarian Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Fangfang Lang

    Full Text Available Resveratrol (trans-3,4,5'-trihydroxystilbene is an active compound in food, such as red grapes, peanuts, and berries. Resveratrol exhibits an anticancer effect on various human cancer cells. However, the mechanism of resveratrol-induced anti-cancer effect at the molecular level remains to be elucidated. In this study, the mechanism underlying the anti-cancer effect of resveratrol in human ovarian cancer cells (OVCAR-3 and Caov-3 was investigated using various molecular biology techniques, such as flow cytometry, western blotting, and RNA interference, with a major focus on the potential role of autophagy in resveratrol-induced apoptotic cell death. We demonstrated that resveratrol induced reactive oxygen species (ROS generation, which triggers autophagy and subsequent apoptotic cell death. Resveratrol induced ATG5 expression and promoted LC3 cleavage. The apoptotic cell death induced by resveratrol was attenuated by both pharmacological and genetic inhibition of autophagy. The autophagy inhibitor chloroquine, which functions at the late stage of autophagy, significantly reduced resveratrol-induced cell death and caspase 3 activity in human ovarian cancer cells. We also demonstrated that targeting ATG5 by siRNA also suppressed resveratrol-induced apoptotic cell death. Thus, we concluded that a common pathway between autophagy and apoptosis exists in resveratrol-induced cell death in OVCAR-3 human ovarian cancer cells.

  16. Cisplatin-induced apoptosis inhibits autophagy, which acts as a pro-survival mechanism in human melanoma cells.

    Science.gov (United States)

    Del Bello, Barbara; Toscano, Marzia; Moretti, Daniele; Maellaro, Emilia

    2013-01-01

    The interplay between a non-lethal autophagic response and apoptotic cell death is still a matter of debate in cancer cell biology. In the present study performed on human melanoma cells, we investigate the role of basal or stimulated autophagy in cisplatin-induced cytotoxicity, as well as the contribution of cisplatin-induced activation of caspases 3/7 and conventional calpains. The results show that, while down-regulating Beclin-1, Atg14 and LC3-II, cisplatin treatment inhibits the basal autophagic response, impairing a physiological pro-survival response. Consistently, exogenously stimulated autophagy, obtained with trehalose or calpains inhibitors (MDL-28170 and calpeptin), protects from cisplatin-induced apoptosis, and such a protection is reverted by inhibiting autophagy with 3-methyladenine or ATG5 silencing. In addition, during trehalose-stimulated autophagy, the cisplatin-induced activation of calpains is abrogated, suggesting the existence of a feedback loop between the autophagic process and calpains. On the whole, our results demonstrate that in human melanoma cells autophagy may function as a beneficial stress response, hindered by cisplatin-induced death mechanisms. In a therapeutic perspective, these findings suggest that the efficacy of cisplatin-based polychemotherapies for melanoma could be potentiated by inhibitors of autophagy.

  17. Low shear stress induces vascular eNOS uncoupling via autophagy-mediated eNOS phosphorylation.

    Science.gov (United States)

    Zhang, Jun-Xia; Qu, Xin-Liang; Chu, Peng; Xie, Du-Jiang; Zhu, Lin-Lin; Chao, Yue-Lin; Li, Li; Zhang, Jun-Jie; Chen, Shao-Liang

    2018-05-01

    Uncoupled endothelial nitric oxide synthase (eNOS) produces O 2 - instead of nitric oxide (NO). Earlier, we reported rapamycin, an autophagy inducer and inhibitor of cellular proliferation, attenuated low shear stress (SS) induced O 2 - production. Nevertheless, it is unclear whether autophagy plays a critical role in the regulation of eNOS uncoupling. Therefore, this study aimed to investigate the modulation of autophagy on eNOS uncoupling induced by low SS exposure. We found that low SS induced endothelial O 2 - burst, which was accompanied by reduced NO release. Furthermore, inhibition of eNOS by L-NAME conspicuously attenuated low SS-induced O 2 - releasing, indicating eNOS uncoupling. Autophagy markers such as LC3 II/I ratio, amount of Beclin1, as well as ULK1/Atg1 were increased during low SS exposure, whereas autophagic degradation of p62/SQSTM1 was markedly reduced, implying impaired autophagic flux. Interestingly, low SS-induced NO reduction could be reversed by rapamycin, WYE-354 or ATG5 overexpression vector via restoration of autophagic flux, but not by N-acetylcysteine or apocynin. eNOS uncoupling might be ascribed to autophagic flux blockade because phosphorylation of eNOS Thr495 by low SS or PMA stimulation was also regulated by autophagy. In contrast, eNOS acetylation was not found to be regulated by low SS and autophagy. Notably, although low SS had no influence on eNOS Ser1177 phosphorylation, whereas boosted eNOS Ser1177 phosphorylation by rapamycin were in favor of the eNOS recoupling through restoration of autophagic flux. Taken together, we reported a novel mechanism for regulation of eNOS uncoupling by low SS via autophagy-mediated eNOS phosphorylation, which is implicated in geometrical nature of atherogenesis. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Antioxidant Supplement Inhibits Skeletal Muscle Constitutive Autophagy rather than Fasting-Induced Autophagy in Mice

    Directory of Open Access Journals (Sweden)

    Zhengtang Qi

    2014-01-01

    Full Text Available In this study, we tested the hypothesis that NAC administration leads to reduced oxidative stress and thus to decreased expression of autophagy markers in young mice. Our results reveal that NAC administration results in reduced muscle mRNA levels of several autophagy markers, including Beclin-1, Atg7, LC3, Atg9, and LAMP2. However, NAC supplement fails to block the activation of skeletal muscle autophagy in response to fasting, because fasting significantly increases the mRNA level of several autophagy markers and LC3 lipidation. We further examined the effects of NAC administration on mitochondrial antioxidant capacity in fed and 24-hour fasted mice. Our results clearly show that NAC administration depresses the expression of manganese superoxide dismutase (MnSOD and TP53-induced glycolysis and apoptosis regulator (TIGAR, both of which play a predominant antioxidant role in mitochondria by reducing ROS level. In addition, we found no beneficial effect of NAC supplement on muscle mass but it can protect from muscle loss in response to fasting. Collectively, our findings indicate that ROS is required for skeletal muscle constitutive autophagy, rather than starvation-induced autophagy, and that antioxidant NAC inhibits constitutive autophagy by the regulation of mitochondrial ROS production and antioxidant capacity.

  19. Hyperosmotic stress stimulates autophagy via polycystin-2.

    Science.gov (United States)

    Peña-Oyarzun, Daniel; Troncoso, Rodrigo; Kretschmar, Catalina; Hernando, Cecilia; Budini, Mauricio; Morselli, Eugenia; Lavandero, Sergio; Criollo, Alfredo

    2017-08-22

    Various intracellular mechanisms are activated in response to stress, leading to adaptation or death. Autophagy, an intracellular process that promotes lysosomal degradation of proteins, is an adaptive response to several types of stress. Osmotic stress occurs under both physiological and pathological conditions, provoking mechanical stress and activating various osmoadaptive mechanisms. Polycystin-2 (PC2), a membrane protein of the polycystin family, is a mechanical sensor capable of activating the cell signaling pathways required for cell adaptation and survival. Here we show that hyperosmotic stress provoked by treatment with hyperosmolar concentrations of sorbitol or mannitol induces autophagy in HeLa and HCT116 cell lines. In addition, we show that mTOR and AMPK, two stress sensor proteins involved modulating autophagy, are downregulated and upregulated, respectively, when cells are subjected to hyperosmotic stress. Finally, our findings show that PC2 is required to promote hyperosmotic stress-induced autophagy. Downregulation of PC2 prevents inhibition of hyperosmotic stress-induced mTOR pathway activation. In conclusion, our data provide new insight into the role of PC2 as a mechanosensor that modulates autophagy under hyperosmotic stress conditions.

  20. A Molecular View of Autophagy in Lepidoptera

    Directory of Open Access Journals (Sweden)

    Davide Romanelli

    2014-01-01

    Full Text Available Metamorphosis represents a critical phase in the development of holometabolous insects, during which the larval body is completely reorganized: in fact, most of the larval organs undergo remodeling or completely degenerate before the final structure of the adult insect is rebuilt. In the past, increasing evidence emerged concerning the intervention of autophagy and apoptosis in the cell death processes that occur in larval organs of Lepidoptera during metamorphosis, but a molecular characterization of these pathways was undertaken only in recent years. In addition to developmentally programmed autophagy, there is growing interest in starvation-induced autophagy. Therefore we are now entering a new era of research on autophagy that foreshadows clarification of the role and regulatory mechanisms underlying this self-digesting process in Lepidoptera. Given that some of the most important lepidopteran species of high economic importance, such as the silkworm, Bombyx mori, belong to this insect order, we expect that this information on autophagy will be fully exploited not only in basic research but also for practical applications.

  1. Autophagy induction for the treatment of cancer.

    Science.gov (United States)

    Pietrocola, Federico; Pol, Jonathan; Vacchelli, Erika; Baracco, Elisa E; Levesque, Sarah; Castoldi, Francesca; Maiuri, Maria Chiara; Madeo, Frank; Kroemer, Guido

    2016-10-02

    Cancer can be viewed in 2 rather distinct ways, namely (i) as a cell-autonomous disease in which malignant cells have escaped control from cell-intrinsic barriers against proliferation and dissemination or (ii) as a systemic disease that involves failing immune control of aberrant cells. Since macroautophagy/autophagy generally increases the fitness of cells as well as their resistance against endogenous or iatrogenic (i.e., relating to illness due to medical intervention) stress, it has been widely proposed that inhibition of autophagy would constitute a valid strategy for sensitizing cancer cells to chemotherapy or radiotherapy. Colliding with this cell-autonomous vision, however, we found that immunosurveillance against transplantable, carcinogen-induced or genetically engineered cancers can be improved by pharmacologically inducing autophagy with caloric restriction mimetics. This positive effect depends on autophagy induction in cancer cells and is mediated by alterations in extracellular ATP metabolism, namely increased release of immunostimulatory ATP and reduced adenosine-dependent recruitment of immunosuppressive regulatory T cells into the tumor bed. The combination of autophagy inducers and chemotherapeutic agents is particularly efficient in reducing cancer growth through the stimulation of CD8 + T lymphocyte-dependent anticancer immune responses.

  2. Autophagy and Liver Ischemia-Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Raffaele Cursio

    2015-01-01

    Full Text Available Liver ischemia-reperfusion (I-R injury occurs during liver resection, liver transplantation, and hemorrhagic shock. The main mode of liver cell death after warm and/or cold liver I-R is necrosis, but other modes of cell death, as apoptosis and autophagy, are also involved. Autophagy is an intracellular self-digesting pathway responsible for removal of long-lived proteins, damaged organelles, and malformed proteins during biosynthesis by lysosomes. Autophagy is found in normal and diseased liver. Although depending on the type of ischemia, warm and/or cold, the dynamic process of liver I-R results mainly in adenosine triphosphate depletion and in production of reactive oxygen species (ROS, leads to both, a local ischemic insult and an acute inflammatory-mediated reperfusion injury, and results finally in cell death. This process can induce liver dysfunction and can increase patient morbidity and mortality after liver surgery and hemorrhagic shock. Whether autophagy protects from or promotes liver injury following warm and/or cold I-R remains to be elucidated. The present review aims to summarize the current knowledge in liver I-R injury focusing on both the beneficial and the detrimental effects of liver autophagy following warm and/or cold liver I-R.

  3. Potentially preventable infant and child deaths identified at autopsy; findings and implications.

    Science.gov (United States)

    Bamber, Andrew R; Mifsud, William; Wolfe, Ingrid; Cass, Hilary; Pryce, Jeremy; Malone, Marian; Sebire, Neil J

    2015-09-01

    The purpose of the study was to determine the proportion of pediatric deaths investigated by HM Coronial autopsy which were potentially preventable deaths due to treatable natural disease, and what implications such findings may have for health policies to reduce their occurrence. A retrospective study of 1779 autopsies of individuals between 7 days and 14 years of age requested by HM Coroner, taking place in one specialist pediatric autopsy center, was undertaken. Cases were included if they involved a definite natural disease process in which appropriate recognition and treatment was likely to have affected their outcome. Strict criteria were used and cases were excluded where the individual had any longstanding condition which might have predisposed them to, or altered the recognition of, acute illness, or its response to therapy. Almost 8% (134/1779) of the study group were potentially preventable deaths as a result of natural disease, the majority occurring in children younger than 2 years of age. Most individuals reported between 1 and 7 days of symptoms before their death, and the majority had sought medical advice during this period, including from general practitioners within working hours, and hospital emergency departments. Of those who had sought medical attention, around one-third had done so more than once (28%, 15/53). Sepsis and pneumonia accounted for the majority of deaths (46 and 34% respectively), with all infections (sepsis, pneumonia and meningitis) accounting for 110/134 (82%). Around 10% of pediatric deaths referred to HM Coroner are potentially preventable, being the result of treatable natural acute illnesses. In many cases medical advice had been sought during the final illness. The results highlight how a review of autopsy data can identify significant findings with the potential to reduce mortality, and the importance of centralized investigation and reporting of pediatric deaths.

  4. Ubiquitin-coated nanodiamonds bind to autophagy receptors for entry into the selective autophagy pathway.

    Science.gov (United States)

    Liu, Kuang-Kai; Qiu, Wei-Ru; Naveen Raj, Emmanuel; Liu, Huei-Fang; Huang, Hou-Syun; Lin, Yu-Wei; Chang, Chien-Jen; Chen, Ting-Hua; Chen, Chinpiao; Chang, Huan-Cheng; Hwang, Jenn-Kang; Chao, Jui-I

    2017-01-02

    Selective macroautophagy/autophagy plays a pivotal role in the processing of foreign pathogens and cellular components to maintain homeostasis in human cells. To date, numerous studies have demonstrated the uptake of nanoparticles by cells, but their intracellular processing through selective autophagy remains unclear. Here we show that carbon-based nanodiamonds (NDs) coated with ubiquitin (Ub) bind to autophagy receptors (SQSTM1 [sequestosome 1], OPTN [optineurin], and CALCOCO2/NDP52 [calcium binding and coiled-coil domain 2]) and are then linked to MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) for entry into the selective autophagy pathway. NDs are ultimately delivered to lysosomes. Ectopically expressed SQSTM1-green fluorescence protein (GFP) could bind to the Ub-coated NDs. By contrast, the Ub-associated domain mutant of SQSTM1 (ΔUBA)-GFP did not bind to the Ub-coated NDs. Chloroquine, an autophagy inhibitor, prevented the ND-containing autophagosomes from fusing with lysosomes. Furthermore, autophagy receptors OPTN and CALCOCO2/NDP52, involved in the processing of bacteria, were found to be involved in the selective autophagy of NDs. However, ND particles located in the lysosomes of cells did not induce mitotic blockage, senescence, or cell death. Single ND clusters in the lysosomes of cells were observed in the xenografted human lung tumors of nude mice. This study demonstrated for the first time that Ub-coated nanoparticles bind to autophagy receptors for entry into the selective autophagy pathway, facilitating their delivery to lysosomes.

  5. Arsenic contamination and potential health risk implications at an abandoned tungsten mine, southern China

    International Nuclear Information System (INIS)

    Liu Chuanping; Luo Chunling; Gao Yun; Li Fangbai; Lin Lanwen; Wu Changan; Li Xiangdong

    2010-01-01

    In an extensive environmental study, field samples, including soil, water, rice, vegetable, fish, human hair and urine, were collected at an abandoned tungsten mine in Shantou City, southern China. Results showed that arsenic (As) concentration in agricultural soils ranged from 3.5 to 935 mg kg -1 with the mean value of 129 mg kg -1 . In addition, As concentration reached up to 325 μg L -1 in the groundwater, and the maximum As concentration in local food were 1.09, 2.38 and 0.60 mg kg -1 for brown rice, vegetable and fish samples, respectively, suggesting the local water resource and food have been severely contaminated with As. Health impact monitoring data revealed that As concentrations in hair and urine samples were up to 2.92 mg kg -1 and 164 μg L -1 , respectively, indicating a potential health risk among the local residents. Effective measurements should be implemented to protect the local community from the As contamination in the environment. - It is the first report on arsenic contamination and potential health risk implications at abandoned Lianhuashan tungsten mine.

  6. Tactile event-related potentials in amyotrophic lateral sclerosis (ALS): Implications for brain-computer interface.

    Science.gov (United States)

    Silvoni, S; Konicar, L; Prats-Sedano, M A; Garcia-Cossio, E; Genna, C; Volpato, C; Cavinato, M; Paggiaro, A; Veser, S; De Massari, D; Birbaumer, N

    2016-01-01

    We investigated neurophysiological brain responses elicited by a tactile event-related potential paradigm in a sample of ALS patients. Underlying cognitive processes and neurophysiological signatures for brain-computer interface (BCI) are addressed. We stimulated the palm of the hand in a group of fourteen ALS patients and a control group of ten healthy participants and recorded electroencephalographic signals in eyes-closed condition. Target and non-target brain responses were analyzed and classified offline. Classification errors served as the basis for neurophysiological brain response sub-grouping. A combined behavioral and quantitative neurophysiological analysis of sub-grouped data showed neither significant between-group differences, nor significant correlations between classification performance and the ALS patients' clinical state. Taking sequential effects of stimuli presentation into account, analyses revealed mean classification errors of 19.4% and 24.3% in healthy participants and ALS patients respectively. Neurophysiological correlates of tactile stimuli presentation are not altered by ALS. Tactile event-related potentials can be used to monitor attention level and task performance in ALS and may constitute a viable basis for future BCIs. Implications for brain-computer interface implementation of the proposed method for patients in critical conditions, such as the late stage of ALS and the (completely) locked-in state, are discussed. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  7. Indoor-breeding of Aedes albopictus in northern peninsular Malaysia and its potential epidemiological implications.

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    Hamady Dieng

    Full Text Available BACKGROUND: The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities. METHODOLOGY/PRINCIPAL FINDINGS: In a series of experiments involving outdoors and indoors breeding populations, we found that Ae. albopictus lives longer in the indoor environment. We also observed increased nighttime biting activity and lifetime fecundity in indoor/domestic adapted females, although they were similar to recently colonized females in body size. CONCLUSION/SIGNIFICANCE: Taken together these data suggest that accommodation of Ae. albopictus to indoor/domestic environment may increase its lifespan, blood feeding success, nuisance and thus vectorial capacity (both in terms of increased vector-host contacts and vector population density. These changes in the breeding behavior of Ae. albopictus, a potential vector of several human pathogens including dengue viruses, require special attention.

  8. Indoor-breeding of Aedes albopictus in northern peninsular Malaysia and its potential epidemiological implications.

    Science.gov (United States)

    Dieng, Hamady; Saifur, Rahman G M; Hassan, Ahmad Abu; Salmah, M R Che; Boots, Michael; Satho, Tomomitsu; Jaal, Zairi; AbuBakar, Sazaly

    2010-07-27

    The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities. In a series of experiments involving outdoors and indoors breeding populations, we found that Ae. albopictus lives longer in the indoor environment. We also observed increased nighttime biting activity and lifetime fecundity in indoor/domestic adapted females, although they were similar to recently colonized females in body size. Taken together these data suggest that accommodation of Ae. albopictus to indoor/domestic environment may increase its lifespan, blood feeding success, nuisance and thus vectorial capacity (both in terms of increased vector-host contacts and vector population density). These changes in the breeding behavior of Ae. albopictus, a potential vector of several human pathogens including dengue viruses, require special attention.

  9. Vorinostat and hydroxychloroquine improve immunity and inhibit autophagy in metastatic colorectal cancer.

    Science.gov (United States)

    Patel, Sukeshi; Hurez, Vincent; Nawrocki, Steffan T; Goros, Martin; Michalek, Joel; Sarantopoulos, John; Curiel, Tyler; Mahalingam, Devalingam

    2016-09-13

    Hydroxychloroquine (HCQ) enhances the anti-cancer activity of the histone deacetylase inhibitor, vorinostat (VOR), in pre-clinical models and early phase clinical studies of metastatic colorectal cancer (mCRC). Mechanisms could include autophagy inhibition, accumulation of ubiquitinated proteins, and subsequent tumor cell apoptosis. There is growing evidence that autophagy inhibition could lead to improved anti-cancer immunity. To date, effects of autophagy on immunity have not been reported in cancer patients. To address this, we expanded an ongoing clinical study to include patients with advanced, refractory mCRC to evaluate further the clinical efficacy and immune effects of VOR plus HCQ. Refractory mCRC patients received VOR 400 milligrams orally with HCQ 600 milligrams orally daily, in a 3-week cycle. The primary endpoint was median progression-free survival (mPFS). Secondary endpoints include median overall survival (mOS), adverse events (AE), pharmacodynamic of inhibition of autophagy in primary tumors, immune cell analyses, and cytokine levels. Twenty patients were enrolled (19 evaluable for survival) with a mPFS of 2.8 months and mOS of 6.7 months. Treatment-related grade 3-4 AEs occurred in 8 patients (40%), with fatigue, nausea/vomiting, and anemia being the most common. Treatment significantly reduced CD4+CD25hiFoxp3+ regulatory and PD-1+ (exhausted) CD4+ and CD8+ T cells and decreased CD45RO-CD62L+ (naive) T cells, consistent with improved anti-tumor immunity. On-study tumor biopsies showed increases in lysosomal protease cathepsin D and p62 accumulation, consistent with autophagy inhibition. Taken together, VOR plus HCQ is active, safe and well tolerated in refractory CRC patients, resulting in potentially improved anti-tumor immunity and inhibition of autophagy.

  10. Cigarette Smoke Exposure Inhibits Bacterial Killing via TFEB-Mediated Autophagy Impairment and Resulting Phagocytosis Defect

    Directory of Open Access Journals (Sweden)

    Garrett Pehote

    2017-01-01

    Full Text Available Introduction. Cigarette smoke (CS exposure is the leading risk factor for COPD-emphysema pathogenesis. A common characteristic of COPD is impaired phagocytosis that causes frequent exacerbations in patients leading to increased morbidity. However, the underlying mechanism is unclear. Hence, we investigated if CS exposure causes autophagy impairment as a mechanism for diminished bacterial clearance via phagocytosis by utilizing murine macrophages (RAW264.7 cells and Pseudomonas aeruginosa (PA01-GFP as an experimental model. Methods. Briefly, RAW cells were treated with cigarette smoke extract (CSE, chloroquine (autophagy inhibitor, TFEB-shRNA, CFTR(inh-172, and/or fisetin prior to bacterial infection for functional analysis. Results. Bacterial clearance of PA01-GFP was significantly impaired while its survival was promoted by CSE (p<0.01, autophagy inhibition (p<0.05; p<0.01, TFEB knockdown (p<0.01; p<0.001, and inhibition of CFTR function (p<0.001; p<0.01 in comparison to the control group(s that was significantly recovered by autophagy-inducing antioxidant drug, fisetin, treatment (p<0.05; p<0.01; and p<0.001. Moreover, investigations into other pharmacological properties of fisetin show that it has significant mucolytic and bactericidal activities (p<0.01; p<0.001, which warrants further investigation. Conclusions. Our data suggests that CS-mediated autophagy impairment as a critical mechanism involved in the resulting phagocytic defect, as well as the therapeutic potential of autophagy-inducing drugs in restoring is CS-impaired phagocytosis.

  11. The Cytoskeleton-Autophagy Connection.

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    Kast, David J; Dominguez, Roberto

    2017-04-24

    Actin cytoskeleton dynamics play vital roles in most forms of intracellular trafficking by promoting the biogenesis and transport of vesicular cargoes. Mounting evidence indicates that actin dynamics and membrane-cytoskeleton scaffolds also have essential roles in macroautophagy, the process by which cellular waste is isolated inside specialized vesicles called autophagosomes for recycling and degradation. Branched actin polymerization is necessary for the biogenesis of autophagosomes from the endoplasmic reticulum (ER) membrane. Actomyosin-based transport is then used to feed the growing phagophore with pre-selected cargoes and debris derived from different membranous organelles inside the cell. Finally, mature autophagosomes detach from the ER membrane by an as yet unknown mechanism, undergo intracellular transport and then fuse with lysosomes, endosomes and multivesicular bodies through mechanisms that involve actin- and microtubule-mediated motility, cytoskeleton-membrane scaffolds and signaling proteins. In this review, we highlight the considerable progress made recently towards understanding the diverse roles of the cytoskeleton in autophagy. Published by Elsevier Ltd.

  12. Potential environmental and regulatory implications of naturally occurring radioactive materials (NORM)

    International Nuclear Information System (INIS)

    Paschoa, A.S.

    1998-01-01

    The immense volume of naturally occurring radioactive materials (NORM) wastes produced annually by extracting industries throughout the world deserves to come to the attention of international and national environmental protection agencies and regulatory bodies. Although a great deal of work has been done in the fields of radiation protection and remedial actions concerning uranium and other mines, the need to dispose of diffuse NORM wastes will have environmental and regulatory implications that thus far are not fully appreciated. NORM wastes constitute, by and large, unwanted byproducts of industrial activities as diverse as thorium and uranium milling, niobium, tin and gold mining extraction, water treatment, and the production of oil, gas, phosphate fertilizer, coal fire and aluminium. The volumes of NORM wastes produced annually could reach levels so high that the existing low level radioactive waste (LLRW) facilities would be readily occupied by NORM if controlled disposal procedures were not adopted. On the other hand, NORM cannot just be ignored as being below radiological concern (BRC) or lower than exempt concentration levels (ECLs), because sometimes NORM concentrations reach levels as high as 1 x 10 3 kBq/kg for 226 Ra, and not much less for 228 Ra. Unfortunately, thus far, there is not enough information available concerning NORM wastes in key industries, though the international scientific community has been concerned, for a long time now, with technologically enhanced natural radiation exposures (TENRE). This article is written with the intention of examining, to the extent possible, the potential environmental and regulatory implications of NORM wastes being produced in selected industries. (Author)

  13. Autophagy in health and disease: focus on the cardiovascular system.

    Science.gov (United States)

    Mialet-Perez, Jeanne; Vindis, Cécile

    2017-12-12

    Autophagy is a highly conserved mechanism of lysosome-mediated protein and organelle degradation that plays a crucial role in maintaining cellular homeostasis. In the last few years, specific functions for autophagy have been identified in many tissues and organs. In the cardiovascular system, autophagy appears to be essential to heart and vessel homeostasis and function; however defective or excessive autophagy activity seems to contribute to major cardiovascular disorders including heart failure (HF) or atherosclerosis. Here, we review the current knowledge on the role of cardiovascular autophagy in physiological and pathophysiological conditions. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  14. Emerging role of autophagy in kidney function, diseases and aging

    Science.gov (United States)

    Huber, Tobias B.; Edelstein, Charles L.; Hartleben, Björn; Inoki, Ken; Jiang, Man; Koya, Daisuke; Kume, Shinji; Lieberthal, Wilfred; Pallet, Nicolas; Quiroga, Alejandro; Ravichandran, Kameswaran; Susztak, Katalin; Yoshida, Sei; Dong, Zheng

    2012-01-01

    Autophagy is a highly conserved process that degrades cellular long-lived proteins and organelles. Accumulating evidence indicates that autophagy plays a critical role in kidney maintenance, diseases and aging. Ischemic, toxic, immunological, and oxidative insults can cause an induction of autophagy in renal epithelial cells modifying the course of various kidney diseases. This review summarizes recent insights on the role of autophagy in kidney physiology and diseases alluding to possible novel intervention strategies for treating specific kidney disorders by modifying autophagy. PMID:22692002

  15. Global Liver Proteome Analysis Using iTRAQ Reveals AMPK-mTOR-Autophagy Signaling Is Altered by Intrauterine Growth Restriction in Newborn Piglets.

    Science.gov (United States)

    Long, Baisheng; Yin, Cong; Fan, Qiwen; Yan, Guokai; Wang, Zhichang; Li, Xiuzhi; Chen, Changqing; Yang, Xingya; Liu, Lu; Zheng, Zilong; Shi, Min; Yan, Xianghua

    2016-04-01

    Intrauterine growth restriction (IUGR) impairs fetal growth and development, perturbs nutrient metabolism, and increases the risk of developing diseases in postnatal life. However, the underlying mechanisms by which IUGR affects fetal liver development and metabolism remain incompletely understood. Here, we applied a high-throughput proteomics approach and biochemical analysis to investigate the impact of IUGR on the liver of newborn piglets. As a result, we identified 78 differentially expressed proteins in the three biological replicates, including 31 significantly up-regulated proteins and 47 significantly down-regulated proteins. Among them, a majority of differentially expressed proteins were related to nutrient metabolism and mitochondrial function. Additionally, many significantly down-regulated proteins participated in the mTOR signaling pathway and the phagosome maturation signaling pathway. Further analysis suggested that glucose concentration and hepatic glycogen storage were both reduced in IUGR newborn piglets, which may contribute to AMPK activation and mTORC1 inhibition. However, AMPK activation and mTORC1 inhibition failed to induce autophagy in the liver of IUGR neonatal pigs. A possible reason is that PP2Ac, a potential candidate in autophagy regulation, is significantly down-regulated in the liver of IUGR newborn piglets. These findings may provide implications for preventing and treating IUGR in human beings and domestic animals.

  16. Autophagy in the light of sphingolipid metabolism

    DEFF Research Database (Denmark)

    Harvald, Eva Bang; Olsen, Anne Sofie Braun; Færgeman, Nils J.

    2015-01-01

    Maintenance of cellular homeostasis requires tight and coordinated control of numerous metabolic pathways, which are governed by interconnected networks of signaling pathways and energy-sensing regulators. Autophagy, a lysosomal degradation pathway by which the cell self-digests its own components......, has over the past decade been recognized as an essential part of metabolism. Autophagy not only rids the cell of excessive or damaged organelles, misfolded proteins, and invading microorganisms, it also provides nutrients to maintain crucial cellular functions. Besides serving as essential structural...... moieties of biomembranes, lipids including sphingolipids are increasingly being recognized as central regulators of a number of important cellular processes, including autophagy. In the present review we describe how sphingolipids, with special emphasis on ceramides and sphingosine-1-phosphate, can act...

  17. Induction of autophagy by spermidine promotes longevity.

    Science.gov (United States)

    Eisenberg, Tobias; Knauer, Heide; Schauer, Alexandra; Büttner, Sabrina; Ruckenstuhl, Christoph; Carmona-Gutierrez, Didac; Ring, Julia; Schroeder, Sabrina; Magnes, Christoph; Antonacci, Lucia; Fussi, Heike; Deszcz, Luiza; Hartl, Regina; Schraml, Elisabeth; Criollo, Alfredo; Megalou, Evgenia; Weiskopf, Daniela; Laun, Peter; Heeren, Gino; Breitenbach, Michael; Grubeck-Loebenstein, Beatrix; Herker, Eva; Fahrenkrog, Birthe; Fröhlich, Kai-Uwe; Sinner, Frank; Tavernarakis, Nektarios; Minois, Nadege; Kroemer, Guido; Madeo, Frank

    2009-11-01

    Ageing results from complex genetically and epigenetically programmed processes that are elicited in part by noxious or stressful events that cause programmed cell death. Here, we report that administration of spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extended the lifespan of yeast, flies and worms, and human immune cells. In addition, spermidine administration potently inhibited oxidative stress in ageing mice. In ageing yeast, spermidine treatment triggered epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases (HAT), suppressing oxidative stress and necrosis. Conversely, depletion of endogenous polyamines led to hyperacetylation, generation of reactive oxygen species, early necrotic death and decreased lifespan. The altered acetylation status of the chromatin led to significant upregulation of various autophagy-related transcripts, triggering autophagy in yeast, flies, worms and human cells. Finally, we found that enhanced autophagy is crucial for polyamine-induced suppression of necrosis and enhanced longevity.

  18. IKK connects autophagy to major stress pathways.

    Science.gov (United States)

    Criollo, Alfredo; Senovilla, Laura; Authier, Hélène; Maiuri, Maria Chiara; Morselli, Eugenia; Vitale, Ilio; Kepp, Oliver; Tasdemir, Ezgi; Galluzzi, Lorenzo; Shen, Shensi; Tailler, Maximilien; Delahaye, Nicolas; Tesniere, Antoine; De Stefano, Daniela; Younes, Aména Ben; Harper, Francis; Pierron, Gérard; Lavandero, Sergio; Zitvogel, Laurence; Israel, Alain; Baud, Véronique; Kroemer, Guido

    2010-01-01

    Cells respond to stress by activating cytoplasmic mechanisms as well as transcriptional programs that can lead to adaptation or death. Autophagy represents an important cytoprotective response that is regulated by both transcriptional and transcription-independent pathways. NFkappaB is perhaps the transcription factor most frequently activated by stress and has been ascribed with either pro- or anti-autophagic functions, depending on the cellular context. Our results demonstrate that activation of the IKK (IkappaB kinase) complex, which is critical for the stress-elicited activation of NFkappaB, is sufficient to promote autophagy independent of NFkappaB, and that IKK is required for the optimal induction of autophagy by both physiological and pharmacological autophagic triggers.

  19. Myocardial Autophagy after Severe Burn in Rats

    Science.gov (United States)

    Zhang, Qiong; Shi, Xiao-hua; Huang, Yue-sheng

    2012-01-01

    Background Autophagy plays a major role in myocardial ischemia and hypoxia injury. The present study investigated the effects of autophagy on cardiac dysfunction in rats after severe burn. Methods Protein expression of the autophagy markers LC3 and Beclin 1 were determined at 0, 1, 3, 6, and 12 h post-burn in Sprague Dawley rats subjected to 30% total body surface area 3rd degree burns. Autophagic, apoptotic, and oncotic cell death were evaluated in the myocardium at each time point by immunofluorescence. Changes of cardiac function were measured in a Langendorff model of isolated heart at 6 h post-burn, and the autophagic response was measured following activation by Rapamycin and inhibition by 3-methyladenine (3-MA). The angiotensin converting enzyme inhibitor enalaprilat, the angiotensin receptor I blocker losartan, and the reactive oxygen species inhibitor diphenylene iodonium (DPI) were also applied to the ex vivo heart model to examine the roles of these factors in post-burn cardiac function. Results Autophagic cell death was first observed in the myocardium at 3 h post-burn, occurring in 0.008 ± 0.001% of total cardiomyocytes, and continued to increase to a level of 0.022 ± 0.005% by 12 h post-burn. No autophagic cell death was observed in control hearts. Compared with apoptosis, autophagic cell death occurred earlier and in larger quantities. Rapamycin enhanced autophagy and decreased cardiac function in isolated hearts 6 h post-burn, while 3-MA exerted the opposite response. Enalaprilat, losartan, and DPI all inhibited autophagy and enhanced heart function. Conclusion Myocardial autophagy is enhanced in severe burns and autophagic cell death occurred early at 3 h post-burn, which may contribute to post-burn cardiac dysfunction. Angiotensin II and reactive oxygen species may play important roles in this process by regulating cell signaling transduction. PMID:22768082

  20. Polycystin-2-dependent control of cardiomyocyte autophagy.

    Science.gov (United States)

    Criollo, Alfredo; Altamirano, Francisco; Pedrozo, Zully; Schiattarella, Gabriele G; Li, Dan L; Rivera-Mejías, Pablo; Sotomayor-Flores, Cristian; Parra, Valentina; Villalobos, Elisa; Battiprolu, Pavan K; Jiang, Nan; May, Herman I; Morselli, Eugenia; Somlo, Stefan; de Smedt, Humbert; Gillette, Thomas G; Lavandero, Sergio; Hill, Joseph A

    2018-05-01

    Considerable evidence points to critical roles of intracellular Ca 2+ homeostasis in the modulation and control of autophagic activity. Yet, underlying molecular mechanisms remain unknown. Mutations in the gene (pkd2) encoding polycystin-2 (PC2) are associated with autosomal dominant polycystic kidney disease (ADPKD), the most common inherited nephropathy. PC2 has been associated with impaired Ca 2+ handling in cardiomyocytes and indirect evidence suggests that this protein may be involved in autophagic control. Here, we investigated the role for PC2 as an essential regulator of Ca 2+ homeostasis and autophagy. Activation of autophagic flux triggered by mTOR inhibition either pharmacologically (rapamycin) or by means of nutrient depletion was suppressed in cells depleted of PC2. Moreover, cardiomyocyte-specific PC2 knockout mice (αMhc-cre;Pkd2 F/F mice) manifested impaired autophagic flux in the setting of nutrient deprivation. Stress-induced autophagy was blunted by intracellular Ca 2+ chelation using BAPTA-AM, whereas removal of extracellular Ca 2+ had no effect, pointing to a role of intracellular Ca 2+ homeostasis in stress-induced cardiomyocyte autophagy. To determine the link between stress-induced autophagy and PC2-induced Ca 2+ mobilization, we over-expressed either wild-type PC2 (WT) or a Ca 2+ -channel deficient PC2 mutant (PC2-D509V). PC2 over-expression increased autophagic flux, whereas PC2-D509V expression did not. Importantly, autophagy induction triggered by PC2 over-expression was attenuated by BAPTA-AM, supporting a model of PC2-dependent control of autophagy through intracellular Ca 2+ . Furthermore, PC2 ablation was associated with impaired Ca 2+ handling in cardiomyocytes marked by partial depletion of sarcoplasmic reticulum Ca 2+ stores. Finally, we provide evidence that Ca 2+ -mediated autophagy elicited by PC2 is a mechanism conserved across multiple cell types. Together, this study unveils PC2 as a novel regulator of autophagy acting

  1. Autophagy: one more Nobel Prize for yeast

    Directory of Open Access Journals (Sweden)

    Andreas Zimmermann

    2016-12-01

    Full Text Available The recent announcement of the 2016 Nobel Prize in Physiology or Medicine, awarded to Yoshinori Ohsumi for the discoveries of mechanisms governing autophagy, underscores the importance of intracellular degradation and recycling. At the same time, it further cements yeast, in which this field decisively developed, as a prolific model organism. Here we provide a quick historical overview that mirrors both the importance of autophagy as a conserved and essential process for cellular life and death as well as the crucial role of yeast in its mechanistic characterization.

  2. Molecular Interactions of Autophagy with the Immune System and Cancer

    Directory of Open Access Journals (Sweden)

    Yunho Jin

    2017-08-01

    Full Text Available Autophagy is a highly conserved catabolic mechanism that mediates the degradation of damaged cellular components by inducing their fusion with lysosomes. This process provides cells with an alternative source of energy for the synthesis of new proteins and the maintenance of metabolic homeostasis in stressful environments. Autophagy protects against cancer by mediating both innate and adaptive immune responses. Innate immune receptors and lymphocytes (T and B are modulated by autophagy, which represent innate and adaptive immune responses, respectively. Numerous studies have demonstrated beneficial roles for autophagy induction as well as its suppression of cancer cells. Autophagy may induce either survival or death depending on the cell/tissue type. Radiation therapy is commonly used to treat cancer by inducing autophagy in human cancer cell lines. Additionally, melatonin appears to affect cancer cell death by regulating programmed cell death. In this review, we summarize the current understanding of autophagy and its regulation in cancer.

  3. Role of autophagy in development and progression of acute pancreatitis

    Directory of Open Access Journals (Sweden)

    YANG Shuli

    2014-08-01

    Full Text Available Acute pancreatitis is considered an autodigestive disorder in which inappropriate activation of trypsinogen to trypsin within pancreatic acinar cells leads to the development of pancreatitis. Autophagy is an evolutionarily preserved degradation process of cytoplasmic cellular constituents, and it is one of the early pathological processes in acute pancreatitis. Autophagic flux is impaired in acute pancreatitis, which mediates the key pathologic responses of this disease. Impaired autophagy, dysfunction of lysosomes, and dysregulation of autophagy suggest a disorder of the endolysosomal pathway in acute pancreatitis. The role of autophagy in acute pancreatitis is discussed from the aspects of autophagic process, autophagy and activation of trypsinogen, impaired autophagy and acute pancreatitis, and defective autophagy promoting inflammation.

  4. Induction of autophagy by ARHI (DIRAS3) alters fundamental metabolic pathways in ovarian cancer models

    International Nuclear Information System (INIS)

    Ornelas, Argentina; McCullough, Christopher R.; Lu, Zhen; Zacharias, Niki M.; Kelderhouse, Lindsay E.; Gray, Joshua; Yang, Hailing; Engel, Brian J.; Wang, Yan; Mao, Weiqun; Sutton, Margie N.; Bhattacharya, Pratip K.; Bast, Robert C. Jr.; Millward, Steven W.

    2016-01-01

    Autophagy is a bulk catabolic process that modulates tumorigenesis, therapeutic resistance, and dormancy. The tumor suppressor ARHI (DIRAS3) is a potent inducer of autophagy and its expression results in necroptotic cell death in vitro and tumor dormancy in vivo. ARHI is down-regulated or lost in over 60 % of primary ovarian tumors yet is dramatically up-regulated in metastatic disease. The metabolic changes that occur during ARHI induction and their role in modulating death and dormancy are unknown. We employed Nuclear Magnetic Resonance (NMR)-based metabolomic strategies to characterize changes in key metabolic pathways in both cell culture and xenograft models of ARHI expression and autophagy. These pathways were further interrogated by cell-based immunofluorescence imaging, tracer uptake studies, targeted metabolic inhibition, and in vivo PET/CT imaging. Induction of ARHI in cell culture models resulted in an autophagy-dependent increase in lactate production along with increased glucose uptake and enhanced sensitivity to glycolytic inhibitors. Increased uptake of glutamine was also dependent on autophagy and dramatically sensitized cultured ARHI-expressing ovarian cancer cell lines to glutaminase inhibition. Induction of ARHI resulted in a reduction in mitochondrial respiration, decreased mitochondrial membrane potential, and decreased Tom20 staining suggesting an ARHI-dependent loss of mitochondrial function. ARHI induction in mouse xenograft models resulted in an increase in free amino acids, a transient increase in [ 18 F]-FDG uptake, and significantly altered choline metabolism. ARHI expression has previously been shown to trigger autophagy-associated necroptosis in cell culture. In this study, we have demonstrated that ARHI expression results in decreased cellular ATP/ADP, increased oxidative stress, and decreased mitochondrial function. While this bioenergetic shock is consistent with programmed necrosis, our data indicates that the accompanying up

  5. [Radiation-induced bystander effect: the important part of ionizing radiation response. Potential clinical implications].

    Science.gov (United States)

    Wideł, Maria; Przybyszewski, Waldemar; Rzeszowska-Wolny, Joanna

    2009-08-18

    It has long been a central radiobiological dogma that the damaging effects of ionizing radiation, such as cell death, cytogenetic changes, apoptosis, mutagenesis, and carcinogenesis, are the results of the direct ionization of cell structures, particularly DNA, or indirect damage via water radiolysis products. However, several years ago attention turned to a third mechanism of radiation, termed the "bystander effect" or "radiation-induced bystander effect" (RIBE). This is induced by agents and signals emitted by directly irradiated cells and manifests as a lowering of survival, cytogenetic damage, apoptosis enhancement, and biochemical changes in neighboring non-irradiated cells. The bystander effect is mainly observed in in vitro experiments using very low doses of alpha particles (range; mGy, cGy), but also after conventional irradiation (X-rays, gamma rays) at low as well as conventional doses. The mechanisms responsible for the bystander effect are complex and still poorly understood. It is believed that molecular signals released from irradiated cells induce different signaling ways in non-irradiated neighboring cells, leading to the observed events. The molecular signals may be transmitted through gap junction intercellular communication and through a medium transfer mechanism. The nature of these transmitted factors are diverse, and still not definitely established. It seems that RIBE may have important clinical implications for health risk associated with radiation exposure. Potentially, this effect may have important implications in the creation of whole-body or localized side effects in tissues beyond the irradiation field and also in low-dose radiological and radioisotope diagnostics. Factors emitted by irradiated cells may result in the risk of genetic instability, mutations, and second primary cancer induction. They might also have their own part in inducing and extending post-radiation side effects in normal tissue. The bystander effect may be a

  6. Radiation-induced bystander effect: The important part of ionizing radiation response. Potential clinical implications

    Directory of Open Access Journals (Sweden)

    Maria Wideł

    2009-08-01

    Full Text Available It has long been a central radiobiological dogma that the damaging effects of ionizing radiation, such as cell death, cytogenetic changes, apoptosis, mutagenesis, and carcinogenesis, are the results of the direct ionization of cell structures, particularly DNA, or indirect damage via water radiolysis products. However, several years ago attention turned to a third mechanism of radiation, termed the “bystander effect” or “radiation-induced bystander effect” (RIBE. This is induced by agents and signals emitted by directly irradiated cells and manifests as a lowering of survival, cytogenetic damage, apoptosis enhancement, and biochemical changes in neighboring non-irradiated cells. The bystander effect is mainly observed in in vitro experiments using very low doses of alpha particles (range; mGy, cGy, but also after conventional irradiation (X-rays, gamma rays at low as well as conventional doses. The mechanisms responsible for the bystander effect are complex and still poorly understood. It is believed that molecular signals released from irradiated cells induce different signaling ways in non-irradiated neighboring cells, leading to the observed events. The molecular signals may be transmitted through gap junction intercellular communication and through a medium transfer mechanism. The nature of these transmitted factors are diverse, and still not defi nitely established. It seems that RIBE may have important clinical implications for health risk associated with radiation exposure. Potentially, this effectmay have important implications in the creation of whole-body or localized side effects in tissues beyond the irradiation fi eld and also in low-dose radiological and radioisotope diagnostics. Factors emitted by irradiated cells may result in the risk of genetic instability, mutations, and second primary cancer induction. They might also have their own part in inducing and extending post-radiation side effects in normal tissue. The

  7. LC3B is indispensable for selective autophagy of p62 but not basal autophagy

    International Nuclear Information System (INIS)

    Maruyama, Yoko; Sou, Yu-Shin; Kageyama, Shun; Takahashi, Takao; Ueno, Takashi; Tanaka, Keiji; Komatsu, Masaaki; Ichimura, Yoshinobu

    2014-01-01

    Highlights: • Knockdown of LC3 or GABARAP families did not affect the basal autophagy. • LC3B has a higher affinity for the autophagy-specific substrate, p62, than GABARAPs. • siRNA-mediated knockdown of LC3B, but not that of GABARAPs, resulted in significant accumulation of p62. - Abstract: Autophagy is a unique intracellular protein degradation system accompanied by autophagosome formation. Besides its important role through bulk degradation in supplying nutrients, this system has an ability to degrade certain proteins, organelles, and invading bacteria selectively to maintain cellular homeostasis. In yeasts, Atg8p plays key roles in both autophagosome formation and selective autophagy based on its membrane fusion property and interaction with autophagy adaptors/specific substrates. In contrast to the single Atg8p in yeast, mammals have 6 homologs of Atg8p comprising LC3 and GABARAP families. However, it is not clear these two families have different or similar functions. The aim of this study was to determine the separate roles of LC3 and GABARAP families in basal/constitutive and/or selective autophagy. While the combined knockdown of LC3 and GABARAP families caused a defect in long-lived protein degradation through lysosomes, knockdown of each had no effect on the degradation. Meanwhile, knockdown of LC3B but not GABARAPs resulted in significant accumulation of p62/Sqstm1, one of the selective substrate for autophagy. Our results suggest that while mammalian Atg8 homologs are functionally redundant with regard to autophagosome formation, selective autophagy is regulated by specific Atg8 homologs

  8. LC3B is indispensable for selective autophagy of p62 but not basal autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Yoko [Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506 (Japan); Department of Pediatrics, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Sou, Yu-Shin; Kageyama, Shun [Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506 (Japan); Takahashi, Takao [Department of Pediatrics, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Ueno, Takashi [Division of Proteomics and Biomolecular Science, Center for Biomedical Research Resources, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Tanaka, Keiji [Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506 (Japan); Komatsu, Masaaki, E-mail: komatsu-ms@igakuken.or.jp [Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506 (Japan); Department of Biochemistry, School of Medicine, Niigata University, Niigata 951-8510 (Japan); Ichimura, Yoshinobu, E-mail: ichimura-ys@igakuken.or.jp [Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506 (Japan)

    2014-03-28

    Highlights: • Knockdown of LC3 or GABARAP families did not affect the basal autophagy. • LC3B has a higher affinity for the autophagy-specific substrate, p62, than GABARAPs. • siRNA-mediated knockdown of LC3B, but not that of GABARAPs, resulted in significant accumulation of p62. - Abstract: Autophagy is a unique intracellular protein degradation system accompanied by autophagosome formation. Besides its important role through bulk degradation in supplying nutrients, this system has an ability to degrade certain proteins, organelles, and invading bacteria selectively to maintain cellular homeostasis. In yeasts, Atg8p plays key roles in both autophagosome formation and selective autophagy based on its membrane fusion property and interaction with autophagy adaptors/specific substrates. In contrast to the single Atg8p in yeast, mammals have 6 homologs of Atg8p comprising LC3 and GABARAP families. However, it is not clear these two families have different or similar functions. The aim of this study was to determine the separate roles of LC3 and GABARAP families in basal/constitutive and/or selective autophagy. While the combined knockdown of LC3 and GABARAP families caused a defect in long-lived protein degradation through lysosomes, knockdown of each had no effect on the degradation. Meanwhile, knockdown of LC3B but not GABARAPs resulted in significant accumulation of p62/Sqstm1, one of the selective substrate for autophagy. Our results suggest that while mammalian Atg8 homologs are functionally redundant with regard to autophagosome formation, selective autophagy is regulated by specific Atg8 homologs.

  9. Plant selenium hyperaccumulation- Ecological effects and potential implications for selenium cycling and community structure.

    Science.gov (United States)

    Reynolds, R Jason B; Pilon-Smits, Elizabeth A H

    2018-04-25

    Selenium (Se) hyperaccumulation occurs in ~50 plant taxa native to seleniferous soils in Western USA. Hyperaccumulator tissue Se levels, 1000-15,000 mg/kg dry weight, are typically 100 times higher than surrounding vegetation. Relative to other species, hyperaccumulators also transform Se more into organic forms. We review abiotic and biotic factors influencing soil Se distribution and bioavailability, soil being the source of the Se in hyperaccumulators. Next, we summarize the fate of Se in plants, particularly hyperaccumulators. We then extensively review the impact of plant Se accumulation on ecological interactions. Finally, we discuss the potential impact of Se hyperaccumulators on local community composition and Se cycling. Selenium (hyper)accumulation offers ecological advantages: protection from herbivores and pathogens and competitive advantage over other plants. The extreme Se levels in and around hyperaccumulators create a toxic environment for Se-sensitive ecological partners, while offering a niche for Se-resistant partners. Through these dual effects, hyperaccumulators may influence species composition in their local environment, as well as Se cycling. The implied effects of Se hyperaccumulation on community assembly and local Se cycling warrant further investigations into the contribution of hyperaccumulators and general terrestrial vegetation to global Se cycling and may serve as a case study for how trace elements influence ecological processes. Furthermore, understanding ecological implications of plant Se accumulation are vital for safe implementation of biofortification and phytoremediation, technologies increasingly implemented to battle Se deficiency and toxicity. Copyright © 2018. Published by Elsevier B.V.

  10. Addressing potential local adaptation in species distribution models: implications for conservation under climate change

    Science.gov (United States)

    Hällfors, Maria Helena; Liao, Jishan; Dzurisin, Jason D. K.; Grundel, Ralph; Hyvärinen, Marko; Towle, Kevin; Wu, Grace C.; Hellmann, Jessica J.

    2016-01-01

    Species distribution models (SDMs) have been criticized for involving assumptions that ignore or categorize many ecologically relevant factors such as dispersal ability and biotic interactions. Another potential source of model error is the assumption that species are ecologically uniform in their climatic tolerances across their range. Typically, SDMs to treat a species as a single entity, although populations of many species differ due to local adaptation or other genetic differentiation. Not taking local adaptation into account, may lead to incorrect range prediction and therefore misplaced conservation efforts. A constraint is that we often do not know the degree to which populations are locally adapted, however. Lacking experimental evidence, we still can evaluate niche differentiation within a species' range to promote better conservation decisions. We explore possible conservation implications of making type I or type II errors in this context. For each of two species, we construct three separate MaxEnt models, one considering the species as a single population and two of disjunct populations. PCA analyses and response curves indicate different climate characteristics in the current environments of the populations. Model projections into future climates indicate minimal overlap between areas predicted to be climatically suitable by the whole species versus population-based models. We present a workflow for addressing uncertainty surrounding local adaptation in SDM application and illustrate the value of conducting population-based models to compare with whole-species models. These comparisons might result in more cautious management actions when alternative range outcomes are considered.

  11. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    International Nuclear Information System (INIS)

    1988-01-01

    The Office of Health and Environmental Research (OHER) of the US Department of Energy conducts a broad multidisciplinary research program which includes basic biophysics, biophysical chemistry, molecular and cellular biology as well as experimental animal studies and opportunistic human studies. This research is directed at understanding how low levels of radiation of various qualities produce the spectrum of biological effects that are seen for such exposures. This workshop was entitled ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection.'' It ws jointly sponsored by the Department of Energy and the Commission of European Communities. The aim of the workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection. The overview of research provided by this multidisciplinary group will be helpful to the Office in program planning. This report includes a summary of the presentations, extended abstracts, the meeting agenda, research recommendations, and a list of participants. Individual papers are processed separately for the data base

  12. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    The Office of Health and Environmental Research (OHER) of the US Department of Energy conducts a broad multidisciplinary research program which includes basic biophysics, biophysical chemistry, molecular and cellular biology as well as experimental animal studies and opportunistic human studies. This research is directed at understanding how low levels of radiation of various qualities produce the spectrum of biological effects that are seen for such exposures. This workshop was entitled ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection.'' It ws jointly sponsored by the Department of Energy and the Commission of European Communities. The aim of the workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection. The overview of research provided by this multidisciplinary group will be helpful to the Office in program planning. This report includes a summary of the presentations, extended abstracts, the meeting agenda, research recommendations, and a list of participants. Individual papers are processed separately for the data base.

  13. Drug-drug interactions involving lysosomes: mechanisms and potential clinical implications.

    Science.gov (United States)

    Logan, Randall; Funk, Ryan S; Axcell, Erick; Krise, Jeffrey P

    2012-08-01

    Many commercially available, weakly basic drugs have been shown to be lysosomotropic, meaning they are subject to extensive sequestration in lysosomes through an ion trapping-type mechanism. The extent of lysosomal trapping of a drug is an important therapeutic consideration because it can influence both activity and pharmacokinetic disposition. The administration of certain drugs can alter lysosomes such that their accumulation capacity for co-administered and/or secondarily administered drugs is altered. In this review the authors explore what is known regarding the mechanistic basis for drug-drug interactions involving lysosomes. Specifically, the authors address the influence of drugs on lysosomal pH, volume and lipid processing. Many drugs are known to extensively accumulate in lysosomes and significantly alter their structure and function; however, the therapeutic and toxicological implications of this remain controversial. The authors propose that drug-drug interactions involving lysosomes represent an important potential source of variability in drug activity and pharmacokinetics. Most evaluations of drug-drug interactions involving lysosomes have been performed in cultured cells and isolated tissues. More comprehensive in vivo evaluations are needed to fully explore the impact of this drug-drug interaction pathway on therapeutic outcomes.

  14. Variable Methylation Potential in Preterm Placenta: Implication for Epigenetic Programming of the Offspring.

    Science.gov (United States)

    Khot, Vinita V; Chavan-Gautam, Preeti; Mehendale, Savita; Joshi, Sadhana R

    2017-06-01

    Children born preterm are reported to be at increased risk of developing noncommunicable diseases in later life. Altered placental DNA methylation patterns are implicated in fetal programming of adult diseases. Our earlier animal studies focus on micronutrients (folic acid, vitamin B 12 ) and long-chain polyunsaturated fatty acids (LCPUFAs) that interact in the 1 carbon cycle, thereby influencing methylation reactions. Our previous studies in women delivering preterm show altered plasma levels of micronutrients and lower plasma LCPUFA levels. We postulate that alterations in the micronutrient metabolism may affect the regulation of enzymes, methionine adenosyltransferase ( MAT2A), and SAH-hydrolase ( AHCY), involved in the production of methyl donor S-adenosylmethionine (SAM), thereby influencing the methylation potential (MP) in the placenta of women delivering preterm. The present study, therefore, examines the mRNA, protein levels of enzymes ( MAT2A and AHCY), SAM, S-adenosylhomocysteine (SAH) levels, and global DNA methylation levels from preterm (n = 73) and term (n = 73) placentae. The enzyme messenger RNA (mRNA) levels were analyzed by real-time quantitative polymerase chain reaction, protein levels by enzyme-linked immunosorbent assay, and SAM-SAH levels by high-performance liquid chromatography. The mRNA levels for MAT2A and AHCY are higher ( P programming of the developing fetus.

  15. Cadmium content of commercial and contaminated rice, Oryza sativa, in Thailand and potential health implications.

    Science.gov (United States)

    Zwicker, R; Promsawad, A; Zwicker, B M; Laoharojanaphand, S

    2010-03-01

    Thailand is the number one global exporter and among the top five producers of rice in the world. A significant increase in anthropogenic contamination in agricultural soils over the past few decades has lead to concerns with cadmium and its uptake in rice. The cadmium levels in Thai rice from different sources/areas were determined and used to estimate the potential health risks to consumers. The cadmium concentration in the commercial rice samples ranged from below the detection limit to 0.016 mg/kg. The cadmium concentrations in the contaminated rice samples ranged from a low of 0.007 mg/kg to a high of 0.579 mg/kg. Five of the calculated values exceed the proposed PTWI, with one value almost three times higher and two values almost double. The three highly elevated values are certainly a concern from a health standpoint. Ultimately, action is required to address the health implications resulting from the cadmium contamination in agricultural soils used for rice production in a few select areas of Thailand. Overall, this study indicates that the vast majority of rice produced, consumed and exported by Thailand is safe pertaining to cadmium content.

  16. Short report: secondary transmission in porcine cysticercosis: description and their potential implications for control sustainability.

    Science.gov (United States)

    Gonzalez, Armando E; López-Urbina, Teresa; Tsang, Byron Y; Gavidia, César M; Garcia, Héctor H; Silva, María E; Ramos, Daphne D; Manzanedo, Rafael; Sánchez-Hidalgo, Lelia; Gilman, Robert H; Tsang, Victor C W

    2005-09-01

    Taenia solium taeniasis/cysticercosis is one of few potentially eradicable infectious diseases and is the target of control programs in several countries. The larval stage of this zoonotic cestode invades the human brain and is responsible for most cases of adult-onset epilepsy in the world. The pig is the natural intermediate host, harboring the larvae or cysticerci. Our current understanding of the life cycle implicates humans as the only definitive host and tapeworm carrier (developing taeniasis) and thus the sole source of infective eggs that are responsible for cysticercosis in both human and pigs through oral-fecal transmission. Here we show evidence of an alternative pig-to-pig route of transmission, previously not suspected to exist. In a series of four experiments, naive sentinel pigs were exposed to pigs that had been infected orally with tapeworm segments (containing infective eggs) and moved to a clean environment. Consistently in all four experiments, at least one of the sentinel pigs became seropositive or infected with parasite cysts with much lower cyst burdens than did primarily infected animals. Second-hand transmission of Taenia solium eggs could explain the overdispersed pattern of porcine cysticercosis, with few pigs harboring heavy parasite burdens and many more harboring small numbers of parasites. This route of transmission opens new avenues for consideration with respect to control strategies.

  17. Selecting for creativity and innovation potential: implications for practice in healthcare education.

    Science.gov (United States)

    Patterson, Fiona; Zibarras, Lara Dawn

    2017-05-01

    The ability to innovate is an important requirement in many organisations. Despite this pressing need, few selection systems in healthcare focus on identifying the potential for creativity and innovation and so this area has been vastly under-researched. As a first step towards understanding how we might select for creativity and innovation, this paper explores the use of a trait-based measure of creativity and innovation potential, and evaluates its efficacy for use in selection for healthcare education. This study uses a sample of 188 postgraduate physicians applying for education and training in UK General Practice. Participants completed two questionnaires (a trait-based measure of creativity and innovation, and a measure of the Big Five personality dimensions) and were also rated by assessors on creative problem solving measured during a selection centre. In exploring the construct validity of the trait-based measure of creativity and innovation, our research clarifies the associations between personality, and creativity and innovation. In particular, our study highlights the importance of motivation in the creativity and innovation process. Results also suggest that Openness to Experience is positively related to creativity and innovation whereas some aspects of Conscientiousness are negatively associated with creativity and innovation. Results broadly support the utility of using a trait-based measure of creativity and innovation in healthcare selection processes, although practically this may be best delivered as part of an interview process, rather than as a screening tool. Findings are discussed in relation to broader implications for placing more priority on creativity and innovation as selection criteria within healthcare education and training in future.

  18. Evaluating spatial patterns of dioxins in sediments to aid determination of potential implications for marine reptiles

    Energy Technology Data Exchange (ETDEWEB)

    Hermanussen, S.; Gaus, C. [National Research Centre for Environmental Toxicology, Brisbane (Australia); Limpus, C.J. [Queensland Environmental Protection Agency, Brisbane (Australia); Paepke, O. [ERGO Forschungsgesellschaft mbH, Hamburg (Germany); Blanshard, W. [Sea World, Gold Coast (Australia); Connell, D. [School of Public Health, Griffith Univ., Brisbane (Australia)

    2004-09-15

    Recent investigations have identified elevated concentrations of polychlorinated dibenzo-p-dioxins (dioxins) in marine sediments and wildlife of Queensland, Australia. While it has been demonstrated that the contamination is widespread and predominantly land-based, limited information exists on the pathways and fate of these compounds within the near-shore marine system. This environment supports unique and threatened species including green sea turtles (Chelonia mydas). Adult green turtles are predominantly herbivorous, feeding on seagrass and algae. Apart from initial migration to feeding grounds (at {proportional_to}10 years of age) and intermittent migrations to breeding grounds (at {proportional_to}30-50 years and thereafter), green turtles remain and feed within relatively small home ranges. Long life-span (50 years or more), near-shore feeding grounds and highly specialized food requirements render green turtles potentially vulnerable to contaminant exposure. Recent studies have shown a relationship between PCDD/F concentrations found in herbivorous marine wildlife and concentrations in sediments of their habitats. Hence, the spatial evaluation of sediment PCDD/F distribution may assist the assessment of green turtle exposure and its potential implications. The present study provides baseline information on green turtle PCDD/F concentrations in Queensland, Australia and investigates exposure pathways. In addition, spatial distribution of PCDD/Fs in sediments from known green turtle feeding regions is assessed using geographic information systems. This represents the first stage of a large scale investigation into the exposure and sensitivity of marine reptiles to dioxins and dioxin-like compounds and to evaluate whether poor health status observed in some populations may be related to contaminant exposure.

  19. Dehydroandrographolide, an iNOS inhibitor, extracted from from Andrographis paniculata (Burm.f.) Nees, induces autophagy in human oral cancer cells

    Science.gov (United States)

    Hsieh, Ming-Ju; Lin, Chiao-Wen; Chiou, Hui-Ling; Yang, Shun-Fa; Chen, Mu-Kuan

    2015-01-01

    Autophagy, which is constitutively executed at the basal level in all cells, promotes cellular homeostasis by regulating the turnover of organelles and proteins. Andrographolide and dehydroandrographolide (DA) are the two principle components of Andrographis paniculata (Burm.f.) Nees. and are the main contributors to its therapeutic properties. However, the pharmacological activities of dehydroandrographolide (DA) remain unclear. In this study, DA induces oral cancer cell death by activating autophagy. Treatment with autophagy inhibitors inhibited DA-induced human oral cancer cell death. In addition, DA increased LC3-II expression and reduced p53 expression in a time- and concentration-dependent manner. Furthermore, DA induced autophagy and decreased cell viability through modulation of p53 expression. DA-induced autophagy was triggered by an activation of JNK1/2 and an inhibition of Akt and p38. In conclusion, this study demonstrated that DA induced autophagy in human oral cancer cells by modulating p53 expression, activating JNK1/2, and inhibiting Akt and p38. Finally, an administration of DA effectively suppressed the tumor formation in the oral carcinoma xenograft model in vivo. This is the first study to reveal the novel function of DA in activating autophagy, suggesting that DA could serve as a new and potential chemopreventive agent for treating human oral cancer. PMID:26356821

  20. Dehydroandrographolide, an iNOS inhibitor, extracted from Andrographis paniculata (Burm.f.) Nees, induces autophagy in human oral cancer cells.

    Science.gov (United States)

    Hsieh, Ming-Ju; Lin, Chiao-Wen; Chiou, Hui-Ling; Yang, Shun-Fa; Chen, Mu-Kuan

    2015-10-13

    Autophagy, which is constitutively executed at the basal level in all cells, promotes cellular homeostasis by regulating the turnover of organelles and proteins. Andrographolide and dehydroandrographolide (DA) are the two principle components of Andrographis paniculata (Burm.f.) Nees. and are the main contributors to its therapeutic properties. However, the pharmacological activities of dehydroandrographolide (DA) remain unclear. In this study, DA induces oral cancer cell death by activating autophagy. Treatment with autophagy inhibitors inhibited DA-induced human oral cancer cell death. In addition, DA increased LC3-II expression and reduced p53 expression in a time- and concentration-dependent manner. Furthermore, DA induced autophagy and decreased cell viability through modulation of p53 expression. DA-induced autophagy was triggered by an activation of JNK1/2 and an inhibition of Akt and p38. In conclusion, this study demonstrated that DA induced autophagy in human oral cancer cells by modulating p53 expression, activating JNK1/2, and inhibiting Akt and p38. Finally, an administration of DA effectively suppressed the tumor formation in the oral carcinoma xenograft model in vivo. This is the first study to reveal the novel function of DA in activating autophagy, suggesting that DA could serve as a new and potential chemopreventive agent for treating human oral cancer.

  1. Onjisaponin B derived from Radix Polygalae enhances autophagy and accelerates the degradation of mutant α-synuclein and huntingtin in PC-12 cells.

    Science.gov (United States)

    Wu, An-Guo; Wong, Vincent Kam-Wai; Xu, Su-Wei; Chan, Wai-Kit; Ng, Choi-In; Liu, Liang; Law, Betty Yuen-Kwan

    2013-11-15

    Emerging evidence indicates important protective roles being played by autophagy in neurodegenerative disorders through clearance of aggregate-prone or mutant proteins. In the current study, we aimed to identify autophagy inducers from Chinese medicinal herbs as a potential neuroprotective agent that enhances the clearance of mutant huntingtin and α-synuclein in PC-12 cells. Through intensive screening using the green fluorescent protein-light chain 3 (GFP-LC3) autophagy detection platform, we found that the ethanol extracts of Radix Polygalae (Yuan Zhi) were capable of inducing autophagy. Further investigation showed that among three single components derived from Radix Polygalae--i.e., polygalacic acid, senegenin and onjisaponin B--onjisaponin B was able to induce autophagy and accelerate both the removal of mutant huntingtin and A53T α-synuclein, which are highly associated with Huntington disease and Parkinson disease, respectively. Our study further demonstrated that onjisaponin B induces autophagy via the AMPK-mTOR signaling pathway. Therefore, findings in the current study provide detailed insights into the protective mechanism of a novel autophagy inducer, which is valuable for further investigation as a new candidate agent for modulating neurodegenerative disorders through the reduction of toxicity and clearance of mutant proteins in the cellular level.

  2. Opposite Effects of Two Human ATG10 Isoforms on Replication of a HCV Sub-genomic Replicon Are Mediated via Regulating Autophagy Flux in Zebrafish

    Directory of Open Access Journals (Sweden)

    Yu-Chen Li

    2018-04-01

    Full Text Available Autophagy is a host mechanism for cellular homeostatic control. Intracellular stresses are symptoms of, and responses to, dysregulation of the physiological environment of the cell. Alternative gene transcription splicing is a mechanism potentially used by a host to respond to physiological or pathological challenges. Here, we aimed to confirm opposite effects of two isoforms of the human autophagy-related protein ATG10 on an HCV subgenomic replicon in zebrafish. A liver-specific HCV subreplicon model was established and exhibited several changes in gene expression typically induced by HCV infection, including overexpression of several HCV-dependent genes (argsyn, leugpcr, rasgbd, and scaf-2, as well as overexpression of several ER stress related genes (atf4, chop, atf6, and bip. Autophagy flux was blocked in the HCV model. Our results indicated that the replication of the HCV subreplicon was suppressed via a decrease in autophagosome formation caused by the autophagy inhibitor 3MA, but enhanced via dysfunction in the lysosomal degradation caused by another autophagy inhibitor CQ. Human ATG10, a canonical isoform in autophagy, facilitated the amplification of the HCV-subgenomic replicon via promoting autophagosome formation. ATG10S, a non-canonical short isoform of the ATG10 protein, promoted autophagy flux, leading to lysosomal degradation of the HCV-subgenomic replicon. Human ATG10S may therefore inhibit HCV replication, and may be an appropriate target for future antiviral drug screening.

  3. Dysregulation of the Autophagy-Endolysosomal System in Amyotrophic Lateral Sclerosis and Related Motor Neuron Diseases

    Directory of Open Access Journals (Sweden)

    Asako Otomo

    2012-01-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is a heterogeneous group of incurable motor neuron diseases (MNDs characterized by a selective loss of upper and lower motor neurons in the brain and spinal cord. Most cases of ALS are sporadic, while approximately 5–10% cases are familial. More than 16 causative genes for ALS/MNDs have been identified and their underlying pathogenesis, including oxidative stress, endoplasmic reticulum stress, excitotoxicity, mitochondrial dysfunction, neural inflammation, protein misfolding and accumulation, dysfunctional intracellular trafficking, abnormal RNA processing, and noncell-autonomous damage, has begun to emerge. It is currently believed that a complex interplay of multiple toxicity pathways is implicated in disease onset and progression. Among such mechanisms, ones that are associated with disturbances of protein homeostasis, the ubiquitin-proteasome system and autophagy, have recently been highlighted. Although it remains to be determined whether disease-associated protein aggregates have a toxic or protective role in the pathogenesis, the formation of them results from the imbalance between generation and degradation of misfolded proteins within neuronal cells. In this paper, we focus on the autophagy-lysosomal and endocytic degradation systems and implication of their dysfunction to the pathogenesis of ALS/MNDs. The autophagy-endolysosomal pathway could be a major target for the development of therapeutic agents for ALS/MNDs.

  4. Exome sequences of multiplex, multigenerational families reveal schizophrenia risk loci with potential implications for neurocognitive performance.

    Science.gov (United States)

    Kos, Mark Z; Carless, Melanie A; Peralta, Juan; Curran, Joanne E; Quillen, Ellen E; Almeida, Marcio; Blackburn, August; Blondell, Lucy; Roalf, David R; Pogue-Geile, Michael F; Gur, Ruben C; Göring, Harald H H; Nimgaonkar, Vishwajit L; Gur, Raquel E; Almasy, Laura

    2017-12-01

    Schizophrenia is a serious mental illness, involving disruptions in thought and behavior, with a worldwide prevalence of about one percent. Although highly heritable, much of the genetic liability of schizophrenia is yet to be explained. We searched for susceptibility loci in multiplex, multigenerational families affected by schizophrenia, targeting protein-altering variation with in silico predicted functional effects. Exome sequencing was performed on 136 samples from eight European-American families, including 23 individuals diagnosed with schizophrenia or schizoaffective disorder. In total, 11,878 non-synonymous variants from 6,396 genes were tested for their association with schizophrenia spectrum disorders. Pathway enrichment analyses were conducted on gene-based test results, protein-protein interaction (PPI) networks, and epistatic effects. Using a significance threshold of FDR < 0.1, association was detected for rs10941112 (p = 2.1 × 10 -5 ; q-value = 0.073) in AMACR, a gene involved in fatty acid metabolism and previously implicated in schizophrenia, with significant cis effects on gene expression (p = 5.5 × 10 -4 ), including brain tissue data from the Genotype-Tissue Expression project (minimum p = 6.0 × 10 -5 ). A second SNP, rs10378 located in TMEM176A, also shows risk effects in the exome data (p = 2.8 × 10 -5 ; q-value = 0.073). PPIs among our top gene-based association results (p < 0.05; n = 359 genes) reveal significant enrichment of genes involved in NCAM-mediated neurite outgrowth (p = 3.0 × 10 -5 ), while exome-wide SNP-SNP interaction effects for rs10941112 and rs10378 indicate a potential role for kinase-mediated signaling involved in memory and learning. In conclusion, these association results implicate AMACR and TMEM176A in schizophrenia risk, whose effects may be modulated by genes involved in synaptic plasticity and neurocognitive performance. © 2017 Wiley Periodicals, Inc.

  5. Parkinson's Disease: Leucine-Rich Repeat Kinase 2 and Autophagy, Intimate Enemies

    Directory of Open Access Journals (Sweden)

    José M. Bravo-San Pedro

    2012-01-01

    Full Text Available Parkinson's disease is the second common neurodegenerative disorder, after Alzheimer's disease. It is a clinical syndrome characterized by loss of dopamine-generating cells in the substancia nigra, a region of the midbrain. The etiology of Parkinson's disease has long been through to involve both genetic and environmental factors. Mutations in the leucine-rich repeat kinase 2 gene cause late-onset Parkinson's disease with a clinical appearance indistinguishable from Parkinson's disease idiopathic. Autophagy is an intracellular catabolic mechanism whereby a cell recycles or degrades damage proteins and cytoplasmic organelles. This degradative process has been associated with cellular dysfunction in neurodegenerative processes including Parkinson's disease. We discuss the role of leucine-rich repeat kinase 2 in autophagy, and how the deregulations of this degradative mechanism in cells can be implicated in the Parkinson's disease etiology.

  6. CD4 T cell autophagy is integral to memory maintenance.

    Science.gov (United States)

    Murera, Diane; Arbogast, Florent; Arnold, Johan; Bouis, Delphine; Muller, Sylviane; Gros, Frédéric

    2018-04-13

    Studies of mice deficient for autophagy in T cells since thymic development, concluded that autophagy is integral to mature T cell homeostasis. Basal survival and functional impairments in vivo, limited the use of these models to delineate the role of autophagy during the immune response. We generated Atg5 f/f distal Lck (dLck)-cre mice, with deletion of autophagy only at a mature stage. In this model, autophagy deficiency impacts CD8 + T cell survival but has no influence on CD4 + T cell number and short-term activation. Moreover, autophagy in T cells is dispensable during early humoral response but critical for long-term antibody production. Autophagy in CD4 + T cells is required to transfer humoral memory as shown by injection of antigen-experienced cells in naive mice. We also observed a selection of autophagy-competent cells in the CD4 + T cell memory compartment. We performed in vitro differentiation of memory CD4 + T cells, to better characterize autophagy-deficient memory cells. We identified mitochondrial and lipid load defects in differentiated memory CD4 + T cells, together with a compromised survival, without any collapse of energy production. We then propose that memory CD4 + T cells rely on autophagy for their survival to regulate toxic effects of mitochondrial activity and lipid overload.

  7. Mutant p53 protein localized in the cytoplasm inhibits autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Tasdemir, Ezgi; Maiuri, Maria Chiara; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Vicencio, José Miguel; Soussi, Thierry; Kroemer, Guido

    2008-10-01

    The knockout, knockdown or chemical inhibition of p53 stimulates autophagy. Moreover, autophagy-inducing stimuli such as nutrient depletion, rapamycin or lithium cause the depletion of cytoplasmic p53, which in turn is required for the induction of autophagy. Here, we show that retransfection of p53(-/-) HCT 116 colon carcinoma cells with wild type p53 decreases autophagy down to baseline levels. Surprisingly, one third among a panel of 22 cancer-associated p53 single amino acid mutants also inhibited autophagy when transfected into p53(-/-) cells. Those variants of p53 that preferentially localize to the cytoplasm effectively repressed autophagy, whereas p53 mutants that display a prominently nuclear distribution failed to inhibit autophagy. The investigation of a series of deletion mutants revealed that removal of the DNA-binding domain from p53 fails to interfere with its role in the regulation of autophagy. Altogether, these results identify the cytoplasmic localization of p53 as the most important feature for p53-mediated autophagy inhibition. Moreover, the structural requirements for the two biological activities of extranuclear p53, namely induction of apoptosis and inhibition of autophagy, are manifestly different.

  8. Impairment of autophagy: From hereditary disorder to drug intoxication

    International Nuclear Information System (INIS)

    Aki, Toshihiko; Funakoshi, Takeshi; Unuma, Kana; Uemura, Koichi

    2013-01-01

    At first, the molecular mechanism of autophagy was unveiled in a unicellular organism Saccharomyces cerevisiae (budding yeast), followed by the discovery that the basic mechanism of autophagy is conserved in multicellular organisms including mammals. Although autophagy was considered to be a non-selective bulk protein degradation system to recycle amino acids during periods of nutrient starvation, it is also believed to be an essential mechanism for the selective elimination of proteins/organelles that are damaged under pathological conditions. Research advances made using autophagy-deficient animals have revealed that impairments of autophagy often underlie the pathogenesis of hereditary disorders such as Danon, Parkinson's, Alzheimer's, and Huntington's diseases, and amyotrophic lateral sclerosis. On the other hand, there are many reports that drugs and toxicants, including arsenic, cadmium, paraquat, methamphetamine, and ethanol, induce autophagy during the development of their toxicity on many organs including heart, brain, lung, kidney, and liver. Although the question as to whether autophagic machinery is involved in the execution of cell death or not remains controversial, the current view of the role of autophagy during cell/tissue injury is that it is an important, often essential, cytoprotective reaction; disturbances in cytoprotective autophagy aggravate cell/tissue injuries. The purpose of this review is to provide (1) a gross summarization of autophagy processes, which are becoming more important in the field of toxicology, and (2) examples of important studies reporting the involvement of perturbations in autophagy in cell/tissue injuries caused by acute as well as chronic intoxication

  9. Autophagy fails to prevent glucose deprivation/glucose reintroduction-induced neuronal death due to calpain-mediated lysosomal dysfunction in cortical neurons.

    Science.gov (United States)

    Gerónimo-Olvera, Cristian; Montiel, Teresa; Rincon-Heredia, Ruth; Castro-Obregón, Susana; Massieu, Lourdes

    2017-06-29

    Autophagy is triggered during nutrient and energy deprivation in a variety of cells as a homeostatic response to metabolic stress. In the CNS, deficient autophagy has been implicated in neurodegenerative diseases and ischemic brain injury. However, its role in hypoglycemic damage is poorly understood and the dynamics of autophagy during the hypoglycemic and the glucose reperfusion periods, has not been fully described. In the present study, we analyzed the changes in the content of the autophagy proteins BECN1, LC3-II and p62/SQSTM1 by western blot, and autophagosome formation was followed through time-lapse experiments, during glucose deprivation (GD) and glucose reintroduction (GR) in cortical cultures. According to the results, autophagosome formation rapidly increased during GD, and was followed by an active autophagic flux early after glucose replenishment. However, cells progressively died during GR and autophagy inhibition reduced neuronal death. Neurons undergoing apoptosis during GR did not form autophagosomes, while those surviving up to late GR showed autophagosomes. Calpain activity strongly increased during GR and remained elevated during progressive neuronal death. Its activation led to the cleavage of LAMP2 resulting in lysosome membrane permeabilization (LMP) and release of cathepsin B to the cytosol. Calpain inhibition prevented LMP and increased the number of neurons containing lysosomes and autophagosomes increasing cell viability. Taken together, the present results suggest that calpain-mediated lysosome dysfunction during GR turns an adaptive autophagy response to energy stress into a defective autophagy pathway, which contributes to neuronal death. In these conditions, autophagy inhibition results in the improvement of cell survival.

  10. Dihydroptychantol A, a macrocyclic bisbibenzyl derivative, induces autophagy and following apoptosis associated with p53 pathway in human osteosarcoma U2OS cells

    International Nuclear Information System (INIS)

    Li Xia; Wu, William K.K.; Sun Bin; Cui Min; Liu Shanshan; Gao Jian; Lou Hongxiang

    2011-01-01

    Dihydroptychantol A (DHA), a novel macrocyclic bisbibenzyl compound extracted from liverwort Asterella angusta, has antifungal and multi-drug resistance reversal properties. Here, the chemically synthesized DHA was employed to test its anti-cancer activities in human osteosarcoma U2OS cells. Our results demonstrated that DHA induced autophagy followed by apoptotic cell death accompanied with G 2 /M-phase cell cycle arrest in U2OS cells. DHA-induced autophagy was morphologically characterized by the formation of double membrane-bound autophagic vacuoles recognizable at the ultrastructural level. DHA also increased the levels of LC3-II, a marker of autophagy. Surprisingly, DHA-mediated apoptotic cell death was potentiated by the autophagy inhibitor 3-methyladenine, suggesting that autophagy may play a protective role that impedes the eventual cell death. Furthermore, p53 was shown to be involved in DHA-meditated autophagy and apoptosis. In this connection, DHA increased nuclear expression of p53, induced p53 phosphorylation, and upregulated p53 target gene p21 Waf1/Cip1 . In contrast, cytoplasmic p53 was reduced by DHA, which contributed to the stimulation of autophagy. In relation to the cell cycle, DHA decreased the expression of cyclin B 1 , a cyclin required for progression through the G 2 /M phase. Taken together, DHA induces G 2 /M-phase cell cycle arrest and apoptosis in U2OS cells. DHA-induced apoptosis was preceded by the induction of protective autophagy. DHA-mediated autophagy and apoptosis are associated with the cytoplasmic and nuclear functions of p53.

  11. Induction of cytoprotective autophagy in PC-12 cells by cadmium

    International Nuclear Information System (INIS)

    Wang, Qiwen; Zhu, Jiaqiao; Zhang, Kangbao; Jiang, Chenyang; Wang, Yi; Yuan, Yan; Bian, Jianchun; Liu, Xuezhong; Gu, Jianhong; Liu, Zongping

    2013-01-01

    Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity

  12. Autophagy meets fused in sarcoma-positive stress granules.

    Science.gov (United States)

    Matus, Soledad; Bosco, Daryl A; Hetz, Claudio

    2014-12-01

    Mutations in fused in sarcoma and/or translocated in liposarcoma (FUS, TLS or FUS) are linked to familial cases of amyotrophic lateral sclerosis (ALS). Mutant FUS selectively accumulates into discrete cytosolic structures known as stress granules under various stress conditions. In addition, mutant FUS expression can alter the dynamics and morphology of stress granules. Although the link between mutant FUS and stress granules is well established, the mechanisms modulating stress granule formation and disassembly in the context of ALS are poorly understood. In this issue of Neurobiology of Aging, Ryu et al. uncover the impact of autophagy on the potential toxicity of mutant FUS-positive stress granules. The authors provide evidence indicating that enhanced autophagy activity reduces the number of stress granules, which in the case of cells containing mutant FUS-positive stress granules, is neuroprotective. Overall, this study identifies an intersection between the proteostasis network and alterations in RNA metabolism in ALS through the dynamic assembly and disassembly of stress granules. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Inhibition of autophagy overcomes the nanotoxicity elicited by cadmium-based quantum dots.

    Science.gov (United States)

    Fan, Jiajun; Sun, Yun; Wang, Shaofei; Li, Yubin; Zeng, Xian; Cao, Zhonglian; Yang, Ping; Song, Ping; Wang, Ziyu; Xian, Zongshu; Gao, Hongjian; Chen, Qicheng; Cui, Daxiang; Ju, Dianwen

    2016-02-01

    Cadmium-based quantum dots (QDs) have shown their values in disease diagnosis, cellular and molecular tracking, small-animal imaging, and therapeutic drug delivery. However, the potential safety problems of QDs, mainly due to their nanotoxicities by unclear mechanisms, have greatly limited its applications. To reverse this situation, we investigated the underlying biological mechanisms of the toxicity of Quantum Dots CdTe/CdS 655 (QDs 655) in this work. QDs 655 was found to elicit nanotoxicity in vitro and in vivo. During the process, autophagy was activated, which was characterized by three main stages of autophagic flux including formation of autophagosomes, lysosomes fused with autophagosomes, and degradation of autophagosomes by lysosomes. Furthermore, the autophagic cell death was demonstrated in vitro under QDs 655 treatment while inhibition of autophagy by pharmacological inhibitors or genetic approaches could attenuate the toxicity induced by QDs 655 in vitro and in vivo. These results indicated that autophagic flux and autophagic cell death were triggered by QDs 655, which elucidated the critical role of autophagy in QDs 655 induced toxicity. Our data may suggest the approach to overcome the toxicity of QDs and other nanoparticles by autophagy inhibition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Autophagy contributes to apoptosis in A20 and EL4 lymphoma cells treated with fluvastatin.

    Science.gov (United States)

    Qi, Xu-Feng; Kim, Dong-Heui; Lee, Kyu-Jae; Kim, Cheol-Su; Song, Soon-Bong; Cai, Dong-Qing; Kim, Soo-Ki

    2013-11-08

    Convincing evidence indicates that statins stimulate apoptotic cell death in several types of proliferating tumor cells in a cholesterol-lowering-independent manner. However, the relationship between apoptosis and autophagy in lymphoma cells exposed to statins remains unclear. The objective of this study was to elucidate the potential involvement of autophagy in fluvastatin-induced cell death of lymphoma cells. We found that fluvastatin treatment enhanced the activation of pro-apoptotic members such as caspase-3 and Bax, but suppressed the activation of anti-apoptotic molecule Bcl-2 in lymphoma cells including A20 and EL4 cells. The process was accompanied by increases in numbers of annexin V alone or annexin V/PI double positive cells. Furthermore, both autophagosomes and increases in levels of LC3-II were also observed in fluvastatin-treated lymphoma cells. However, apoptosis in fluvastatin-treated lymphoma cells could be blocked by the addition of 3-methyladenine (3-MA), the specific inhibitor of autophagy. Fluvastatin-induced activation of caspase-3, DNA fragmentation, and activation of LC3-II were blocked by metabolic products of the HMG-CoA reductase reaction, such as mevalonate, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). These results suggest that autophagy contributes to fluvastatin-induced apoptosis in lymphoma cells, and that these regulating processes require inhibition of metabolic products of the HMG-CoA reductase reaction including mevalonate, FPP and GGPP.

  15. Greater sage-grouse science (2015–17)—Synthesis and potential management implications

    Science.gov (United States)

    Hanser, Steven E.; Deibert, Patricia A.; Tull, John C.; Carr, Natasha B.; Aldridge, Cameron L.; Bargsten, Travis D.; Christiansen, Thomas J.; Coates, Peter S.; Crist, Michele R.; Doherty, Kevin E.; Ellsworth, Ethan A.; Foster, Lee J.; Herren, Vicki A.; Miller, Kevin H.; Moser, Ann; Naeve, Robin M.; Prentice, Karen L.; Remington, Thomas E.; Ricca, Mark A.; Shinneman, Douglas J.; Truex, Richard L.; Wiechman , Lief A.; Wilson, Dereck C.; Bowen, Zachary H.

    2018-02-15

    Strategy Actionable Science Plan Team, 2016).In October 2017, after a review of the 2015 Federal plans relative to State sage-grouse plans, in accordance with Secretarial Order 3353, the BLM issued a notice of intent to consider whether to amend some, all, or none of the 2015 land use plans. At that time, the BLM requested the U.S. Geological Survey (USGS) to inform this effort through the development of an annotated bibliography of sage-grouse science published since January 2015 and a report that synthesized and outlined the potential management implications of this new science. Development of the annotated bibliography resulted in the identification and summarization of 169 peer-reviewed scientific publications and reports. The USGS then convened an interagency team (hereafter referred to as the “team”) to develop this report that focuses on the primary topics of importance to the ongoing management of sage-grouse and their habitats.The team developed this report in a three-step process. First, the team identified six primary topic areas for discussion based on the members’ collective knowledge regarding sage-grouse, their habitats, and threats to either or both. Second, the team reviewed all the material in the “Annotated Bibliography of Scientific Research on Greater Sage-Grouse Published since January 2015” to identify the science that addressed the topics. Third, team members discussed the science related to each topic, evaluated the consistency of the science with existing knowledge before 2015, and summarized the potential management implications of this science. The six primary topics identified by the team were:Multiscale habitat suitability and mapping toolsDiscrete anthropogenic activitiesDiffuse activitiesFire and invasive speciesRestoration effectivenessPopulation estimation and genetics

  16. Bioenergy costs and potentials with special attention to implications for the land system

    Science.gov (United States)

    Popp, A.; Lotze-Campen, H.; Dietrich, J.; Klein, D.; Bauer, N.; Krause, M.; Beringer, T.; Gerten, D.

    2011-12-01

    In the coming decades, an increasing competition for global land and water resources can be expected, due to rising demand for agricultural products, goals of nature conservation, and changing production conditions due to climate change. Especially biomass from cellulosic bioenergy crops, such as Miscanthus or poplar, is being proposed to play a substantial role in future energy systems if climate policy aims at stabilizing greenhouse gas (GHG) concentration at low levels. However, the potential of bioenergy for climate change mitigation remains unclear due to large uncertainties about future agricultural yield improvements, land availability for biomass plantations, and implications for the land system. In order to explore the cost-effective contribution of bioenergy to a low carbon transition with special attention to implications for the land system, we present a modeling framework with detailed biophysical and economic representation of the land and energy sector: We have linked the global dynamic vegetation and water balance model LPJmL (Bondeau et al. 2007, Rost et al. 2008), the global land and water use model MAgPIE (Lotze-Campen et al. 2008, Popp et al. 2010), and the global energy-economy-climate model ReMIND (Leimbach et al. 2009). In this modeling framework LPJmL supplies spatially explicit (0.5° resolution) agricultural yields as well as carbon and water stocks and fluxes. Based on this biophysical input MAgPIE delivers cost-optimized land use patterns (0.5° resolution), associated GHG emissions and rates of future yield increases in agricultural production. Moreover, shadow prices are calculated for irrigation water (as an indicator for water scarcity), food commodities, and bioenergy (as an indicator for changes in production costs) under different land use constraints such as forest conservation for climate change mitigation and as a contribution to biodiversity conservation. The energy-economy-climate model ReMIND generates the demand for

  17. STAKEHOLDERS’ OPINIONS AND EXPECTATIONS OF THE GLOBAL FUND AND THEIR POTENTIAL ECONOMIC IMPLICATIONS

    Science.gov (United States)

    Galárraga, Omar; Bertozzi, Stefano M.

    2009-01-01

    Objective To analyze stakeholder opinions and expectations of the Global Fund to Fight AIDS, Tuberculosis, and Malaria, and to discuss their potential economic and financial implications. Design The Global Fund commissioned an independent study, the “360° Stakeholder Assessment,” to canvas feedback on the organization’s reputation and performance with an on-line survey of 909 respondents representing major stakeholders worldwide. We created a proxy for expectations based on categorical responses for specific Global Fund attributes’ importance to the stakeholders, and current perceived performance. Methods Using multivariate regression, we analyzed 23 unfulfilled expectations related to: resource mobilization; impact measurement; harmonization and inclusion; effectiveness of the Global Fund partner environment; and portfolio characteristics. The independent variables are personal- and regional-level characteristics that affect expectations. Results The largest unfulfilled expectations relate to: mobilization of private sector resources; efficiency in disbursing funds; and assurance that people affected by the three diseases are reached. Stakeholders involved with the Fund through the Country Coordinating Mechanisms, those working in multilateral organizations, and persons living with HIV are more likely to have unfulfilled expectations. In contrast, higher levels of involvement with the Fund correlate with fulfilled expectations. Stakeholders living in sub-Saharan Africa were less likely to have their expectations met. Conclusions Stakeholders unfulfilled expectations result largely from factors external to them, but also from factors over which they have influence. In particular, attributes related to partnership score poorly even though stakeholders have influence in that area. Joint efforts to address perceived performance gaps may improve future performance, and positively influence investment levels and economic viability. PMID:18664957

  18. Hemi-bucket-handle tears of the meniscus: appearance on MRI and potential surgical implications

    Energy Technology Data Exchange (ETDEWEB)

    Engstrom, Bjorn I.; Vinson, Emily N.; Helms, Clyde A. [Duke University Medical Center, Department of Radiology, Box 3808, Durham, NC (United States); Taylor, Dean C.; Garrett, William E. [Duke University Medical Center, Department of Orthopaedics, Box 3810, Durham, NC (United States)

    2012-08-15

    To describe a type of meniscus flap tear resembling a bucket-handle tear, named a ''hemi-bucket-handle'' tear; to compare its imaging features with those of a typical bucket-handle tear; and to discuss the potential therapeutic implications of distinguishing these two types of tears. Five knee MR examinations were encountered with a type of meniscus tear consisting of a flap of tissue from the undersurface of the meniscus displaced toward the intercondylar notch. A retrospective analysis of 100 MR examinations prospectively interpreted as having bucket-handle type tears yielded 10 additional cases with this type of tear. Cases of hemi-bucket-handle tears were reviewed for tear location and orientation, appearance of the superior articular surface of the meniscus, presence and location of displaced meniscal tissue, and presence of several classic signs of bucket-handle tears. A total of 15/15 tears involved the medial meniscus, had tissue displaced toward the notch, and were mainly horizontal in orientation. The superior surface was intact in 11/15 (73.3%). In 1/15 (6.7%) there was an absent-bow-tie sign; 6/15 (40%) had a double-PCL sign; 14/15 (93.3%) had a double-anterior horn sign. We describe a type of undersurface flap tear, named a hemi-bucket-handle tear, which resembles a bucket-handle tear. Surgeons at our institution feel this tear would likely not heal if repaired given its predominantly horizontal orientation, and additionally speculate the tear could be overlooked at arthroscopy. Thus, we feel it is important to distinguish this type of tear from the typical bucket-handle tear. (orig.)

  19. Hemi-bucket-handle tears of the meniscus: appearance on MRI and potential surgical implications

    International Nuclear Information System (INIS)

    Engstrom, Bjorn I.; Vinson, Emily N.; Helms, Clyde A.; Taylor, Dean C.; Garrett, William E.

    2012-01-01

    To describe a type of meniscus flap tear resembling a bucket-handle tear, named a ''hemi-bucket-handle'' tear; to compare its imaging features with those of a typical bucket-handle tear; and to discuss the potential therapeutic implications of distinguishing these two types of tears. Five knee MR examinations were encountered with a type of meniscus tear consisting of a flap of tissue from the undersurface of the meniscus displaced toward the intercondylar notch. A retrospective analysis of 100 MR examinations prospectively interpreted as having bucket-handle type tears yielded 10 additional cases with this type of tear. Cases of hemi-bucket-handle tears were reviewed for tear location and orientation, appearance of the superior articular surface of the meniscus, presence and location of displaced meniscal tissue, and presence of several classic signs of bucket-handle tears. A total of 15/15 tears involved the medial meniscus, had tissue displaced toward the notch, and were mainly horizontal in orientation. The superior surface was intact in 11/15 (73.3%). In 1/15 (6.7%) there was an absent-bow-tie sign; 6/15 (40%) had a double-PCL sign; 14/15 (93.3%) had a double-anterior horn sign. We describe a type of undersurface flap tear, named a hemi-bucket-handle tear, which resembles a bucket-handle tear. Surgeons at our institution feel this tear would likely not heal if repaired given its predominantly horizontal orientation, and additionally speculate the tear could be overlooked at arthroscopy. Thus, we feel it is important to distinguish this type of tear from the typical bucket-handle tear. (orig.)

  20. Green tea extract induces protective autophagy in A549 non-small lung cancer cell line.

    Science.gov (United States)

    Izdebska, Magdalena; Klimaszewska-Wiśniewska, Anna; Hałas, Marta; Gagat, Maciej; Grzanka, Alina

    2015-12-31

    For many decades, polyphenols, including green tea extract catechins, have been reported to exert multiple anti-tumor activities. However, to date the mechanisms of their action have not been completely elucidated. Thus, the aim of this study was to assess the effect of green tea extract on non-small lung cancer A549 cells. A549 cells following treatment with GTE were analyzed using the inverted light and fluorescence microscope. In order to evaluate cell sensitivity and cell death, the MTT assay and Tali image-based cytometer were used, respectively. Ultrastructural alterations were assessed using a transmission electron microscope. The obtained data suggested that GTE, even at the highest dose employed (150 μM), was not toxic to A549 cells. Likewise, the treatment with GTE resulted in only a very small dose-dependent increase in the population of apoptotic cells. However, enhanced accumulation of vacuole-like structures in response to GTE was seen at the light and electron microscopic level. Furthermore, an increase in the acidic vesicular organelles and LC3-II puncta formation was observed under the fluorescence microscope, following GTE treatment. The analysis of the functional status of autophagy revealed that GTE-induced autophagy may provide self-protection against its own cytotoxicity, since we observed that the blockage of autophagy by bafilomycin A1 decreased the viability of A549 cells and potentiated necrotic cell death induction in response to GTE treatment. Collectively, our results revealed that A549 cells are insensitive to both low and high concentrations of the green tea extract, probably due to the induction of cytoprotective autophagy. These data suggest that a potential utility of GTE in lung cancer therapy may lie in its synergistic combinations with drugs or small molecules that target autophagy, rather than in monotherapy.

  1. Green tea extract induces protective autophagy in A549 non-small lung cancer cell line

    Directory of Open Access Journals (Sweden)

    Magdalena Izdebska

    2015-12-01

    Full Text Available Background and objectives: For many decades, polyphenols, including green tea extract catechins, have been reported to exert multiple anti-tumor activities. However, to date the mechanisms of their action have not been completely elucidated. Thus, the aim of this study was to assess the effect of green tea extract on non-small lung cancer A549 cells. Material and methods: A549 cells following treatment with GTE were analyzed using the inverted light and fluorescence microscope. In order to evaluate cell sensitivity and cell death, the MTT assay and Tali image-based cytometer were used, respectively. Ultrastructural alterations were assessed using a transmission electron microscope.Results: The obtained data suggested that GTE, even at the highest dose employed (150 μM, was not toxic to A549 cells. Likewise, the treatment with GTE resulted in only a very small dose-dependent increase in the population of apoptotic cells. However, enhanced accumulation of vacuole-like structures in response to GTE was seen at the light and electron microscopic level. Furthermore, an increase in the acidic vesicular organelles and LC3-II puncta formation was observed under the fluorescence microscope, following GTE treatment. The analysis of the functional status of autophagy revealed that GTE-induced autophagy may provide self-protection against its own cytotoxicity, since we observed that the blockage of autophagy by bafilomycin A1 decreased the viability of A549 cells and potentiated necrotic cell death induction in response to GTE treatment.Conclusion: Collectively, our results revealed that A549 cells are insensitive to both low and high concentrations of the green tea extract, probably due to the induction of cytoprotective autophagy. These data suggest that a potential utility of GTE in lung cancer therapy may lie in its synergistic combinations with drugs or small molecules that target autophagy, rather than in monotherapy.

  2. Shear Stress Induces Phenotypic Modulation of Vascular Smooth Muscle Cells via AMPK/mTOR/ULK1-Mediated Autophagy.

    Science.gov (United States)

    Sun, Liqian; Zhao, Manman; Liu, Aihua; Lv, Ming; Zhang, Jingbo; Li, Youxiang; Yang, Xinjian; Wu, Zhongxue

    2018-03-01

    Phenotypic modulation of vascular smooth muscle cells (VSMCs) is involved in the pathophysiological processes of the intracranial aneurysms (IAs). Although shear stress has been implicated in the proliferation, migration, and phenotypic conversion of VSMCs, the molecular mechanisms underlying these events are currently unknown. In this study, we investigated whether shear stress(SS)-induced VSMC phenotypic modulation was mediated by autophagy involved in adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/Unc-51-like kinase 1 (ULK1) pathway. The results show that shear stress could inhibit the expression of key VSMC contractile genes and induce pro-inflammatory/matrix-remodeling genes levels, contributing to VSMCs phenotypic switching from a contractile to a synthetic phenotype. More importantly, Shear stress also markedly increased the levels of the autophagy marker microtubule-associated protein light chain 3-II (LC3II), Beclin-1, and p62 degradation. The autophagy inhibitor 3-methyladenine (3-MA) significantly blocked shear-induced phenotypic modulation of VSMCs. To further explore the molecular mechanism involved in shear-induced autophagy, we found that shear stress could activate AMPK/mTOR/ULK1 signaling pathway in VSMCs. Compound C, a pharmacological inhibitor of AMPK, significantly reduced the levels of p-AMPK and p-ULK, enhanced p-mTOR level, and finally decreased LC3II and Beclin-1 level, which suggested that activated AMPK/mTOR/ULK1 signaling was related to shear-mediated autophagy. These results indicate that shear stress promotes VSMC phenotypic modulation through the induction of autophagy involved in activating the AMPK/mTOR/ULK1 pathway.

  3. Autophagy activation is involved in 3,4-methylenedioxymethamphetamine ('ecstasy'--induced neurotoxicity in cultured cortical neurons.

    Directory of Open Access Journals (Sweden)

    I-Hsun Li

    Full Text Available Autophagic (type II cell death, characterized by the massive accumulation of autophagic vacuoles in the cytoplasm of cells, has been suggested to play pathogenetic roles in cerebral ischemia, brain trauma, and neurodegenerative disorders. 3,4-Methylenedioxymethamphetamine (MDMA or ecstasy is an illicit drug causing long-term neurotoxicity in the brain. Apoptotic (type I and necrotic (type III cell death have been implicated in MDMA-induced neurotoxicity, while the role of autophagy in MDMA-elicited neurotoxicity has not been investigated. The present study aimed to evaluate the occurrence and contribution of autophagy to neurotoxicity in cultured rat cortical neurons challenged with MDMA. Autophagy activation was monitored by expression of microtubule-associated protein 1 light chain 3 (LC3; an autophagic marker using immunofluorescence and western blot analysis. Here, we demonstrate that MDMA exposure induced monodansylcadaverine (MDC- and LC3B-densely stained autophagosome formation and increased conversion of LC3B-I to LC3B-II, coinciding with the neurodegenerative phase of MDMA challenge. Autophagy inhibitor 3-methyladenine (3-MA pretreatment significantly attenuated MDMA-induced autophagosome accumulation, LC3B-II expression, and ameliorated MDMA-triggered neurite damage and neuronal death. In contrast, enhanced autophagy flux by rapamycin or impaired autophagosome clearance by bafilomycin A1 led to more autophagosome accumulation in neurons and aggravated neurite degeneration, indicating that excessive autophagosome accumulation contributes to MDMA-induced neurotoxicity. Furthermore, MDMA induced phosphorylation of AMP-activated protein kinase (AMPK and its downstream unc-51-like kinase 1 (ULK1, suggesting the AMPK/ULK1 signaling pathway might be involved in MDMA-induced autophagy activation.

  4. Heme oxygenase-1 prevents cardiac dysfunction in streptozotocin-diabetic mice by reducing inflammation, oxidative stress, apoptosis and enhancing autophagy.

    Directory of Open Access Journals (Sweden)

    Yanli Zhao

    Full Text Available Heme oxygenase-1 (HO-1 has been implicated in cardiac dysfunction, oxidative stress, inflammation, apoptosis and autophagy associated with heart failure, and atherosclerosis, in addition to its recognized role in metabolic syndrome and diabetes. Numerous studies have presented contradictory findings about the role of HO-1 in diabetic cardiomyopathy (DCM. In this study, we explored the role of HO-1 in myocardial dysfunction, myofibril structure, oxidative stress, inflammation, apoptosis and autophagy using a streptozotocin (STZ-induced diabetes model in mice systemically overexpressing HO-1 (Tg-HO-1 or mutant HO-1 (Tg-mutHO-1. The diabetic mouse model was induced by multiple peritoneal injections of STZ. Two months after injection, left ventricular (LV function was measured by echocardiography. In addition, molecular biomarkers related to oxidative stress, inflammation, apoptosis and autophagy were evaluated using classical molecular biological/biochemical techniques. Mice with DCM exhibited severe LV dysfunction, myofibril structure disarray, aberrant cardiac oxidative stress, inflammation, apoptosis, autophagy and increased levels of HO-1. In addition, we determined that systemic overexpression of HO-1 ameliorated left ventricular dysfunction, myofibril structure disarray, oxidative stress, inflammation, apoptosis and autophagy in DCM mice. Furthermore, serine/threonine-specific protein kinase (Akt and AMP-activated protein kinase (AMPK phosphorylation is normally inhibited in DCM, but overexpression of the HO-1 gene restored the phosphorylation of these kinases to normal levels. In contrast, the functions of HO-1 in DCM were significantly reversed by overexpression of mutant HO-1. This study underlines the unique roles of HO-1, including the inhibition of oxidative stress, inflammation and apoptosis and the enhancement of autophagy, in the pathogenesis of DCM.

  5. Methods for assessing autophagy and autophagic cell death.

    Science.gov (United States)

    Tasdemir, Ezgi; Galluzzi, Lorenzo; Maiuri, M Chiara; Criollo, Alfredo; Vitale, Ilio; Hangen, Emilie; Modjtahedi, Nazanine; Kroemer, Guido

    2008-01-01

    Autophagic (or type 2) cell death is characterized by the massive accumulation of autophagic vacuoles (autophagosomes) in the cytoplasm of cells that lack signs of apoptosis (type 1 cell death). Here we detail and critically assess a series of methods to promote and inhibit autophagy via pharmacological and genetic manipulations. We also review the techniques currently available to detect autophagy, including transmission electron microscopy, half-life assessments of long-lived proteins, detection of LC3 maturation/aggregation, fluorescence microscopy, and colocalization of mitochondrion- or endoplasmic reticulum-specific markers with lysosomal proteins. Massive autophagic vacuolization may cause cellular stress and represent a frustrated attempt of adaptation. In this case, cell death occurs with (or in spite of) autophagy. When cell death occurs through autophagy, on the contrary, the inhibition of the autophagic process should prevent cellular demise. Accordingly, we describe a strategy for discriminating cell death with autophagy from cell death through autophagy.

  6. Forms, Crosstalks, and the Role of Phospholipid Biosynthesis in Autophagy

    Directory of Open Access Journals (Sweden)

    Leanne Pereira

    2012-01-01

    Full Text Available Autophagy is a highly conserved cellular process occurring during periods of stress to ensure a cell's survival by recycling cytosolic constituents and making products that can be used in energy generation and other essential processes. Three major forms of autophagy exist according to the specific mechanism through which cytoplasmic material is transported to a lysosome. Chaperone-mediated autophagy is a highly selective form of autophagy that delivers specific proteins for lysosomal degradation. Microautophagy is a less selective form of autophagy that occurs through lysosomal membrane invaginations, forming tubes and directly engulfing cytoplasm. Finally, macroautophagy involves formation of new membrane bilayers (autophagosomes that engulf cytosolic material and deliver it to lysosomes. This review provides new insights on the crosstalks between different forms of autophagy and the significance of bilayer-forming phospholipid synthesis in autophagosomal membrane formation.

  7. Induction of autophagy is essential for monocyte-macrophage differentiation

    OpenAIRE

    Zhang, Yan; Morgan, Michael J.; Chen, Kun; Choksi, Swati; Liu, Zheng-gang

    2012-01-01

    Monocytes are programmed to undergo apoptosis in the absence of stimulation. Stimuli that promote monocyte-macrophage differentiation not only cause cellular changes, but also prevent the default apoptosis of monocytes. In the present study, we demonstrate that autophagy is induced when monocytes are triggered to differentiate and that the induction of autophagy is pivotal for the survival and differentiation of monocytes. We also show that inhibition of autophagy results in apoptosis of cell...

  8. Targeting Pediatric Glioma with Apoptosis and Autophagy Manipulation

    Science.gov (United States)

    2014-10-01

    that chloroquine treatments give the most reliable inhibition of autophagy without being directly cytotoxic. Bafilomycin can continue to be used for...in pediatric glioma and its interaction with RTK inhibition and apoptotic pathway activation will enable us to develop efficacious clinical trials...of autophagy, Rab7 and Lamp 2. We are now introducing siRNA against Rab7 and Lamp2 to reiterate the effects of Chloroquine inhibition of autophagy

  9. A microtubule inhibitor, ABT-751, induces autophagy and delays apoptosis in Huh-7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ren-Jie [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Lin, Su-Shuan [Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Wu, Wen-Ren [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Chen, Lih-Ren [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Division of Physiology, Livestock Research Institute, Council of Agriculture, Taiwan (China); Li, Chien-Feng [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan (China); National Institute of Cancer Research, National Health Research Institute, Tainan, Taiwan (China); Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Chen, Han-De; Chou, Chien-Ting; Chen, Ya-Chun [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Liang, Shih-Shin [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Chien, Shang-Tao [Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Shiue, Yow-Ling, E-mail: ylshiue@mail.nsysu.edu.tw [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan (China)

    2016-11-15

    The objective was to investigate the upstream mechanisms of apoptosis which were triggered by a novel anti-microtubule drug, ABT-751, in hepatocellular carcinoma-derived Huh-7 cells. Effects of ABT-751 were evaluated by immunocytochemistry, flow cytometric, alkaline comet, soft agar, immunoblotting, CytoID, green fluorescent protein-microtubule associated protein 1 light chain 3 beta detection, plasmid transfection, nuclear/cytosol fractionation, coimmunoprecipitation, quantitative reverse transcription-polymerase chain reaction, small-hairpin RNA interference and mitochondria/cytosol fractionation assays. Results showed that ABT-751 caused dysregulation of microtubule, collapse of mitochondrial membrane potential, generation of reactive oxygen species (ROS), DNA damage, G{sub 2}/M cell cycle arrest, inhibition of anchorage-independent cell growth and apoptosis in Huh-7 cells. ABT-751 also induced early autophagy via upregulation of nuclear TP53 and downregulation of the AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin (MTOR) pathway. Through modulation of the expression levels of DNA damage checkpoint proteins and G{sub 2}/M cell cycle regulators, ABT-751 induced G{sub 2}/M cell cycle arrest. Subsequently, ABT-751 triggered apoptosis with marked downregulation of B-cell CLL/lymphoma 2, upregulation of mitochondrial BCL2 antagonist/killer 1 and BCL2 like 11 protein levels, and cleavages of caspase 8 (CASP8), CASP9, CASP3 and DNA fragmentation factor subunit alpha proteins. Suppression of ROS significantly decreased ABT-751-induced autophagic and apoptotic cells. Pharmacological inhibition of autophagy significantly increased the percentages of ABT-751-induced apoptotic cells. The autophagy induced by ABT-751 plays a protective role to postpone apoptosis by exerting adaptive responses following microtubule damage, ROS and/or impaired mitochondria. - Highlights: • An anti-microtubule agent, ABT-751, induces autophagy and apoptosis in Huh-7 cells.

  10. Colza cell autophagy induced of high dose of industrial sewage sludge

    Science.gov (United States)

    Lasoued, Najla; Guenole Bilal, Issam; Rejeb, Saloua; Bilal, Essaid; Rejeb, Nejib

    2013-04-01

    . Several authors (Gilchrist, 1998; Larsen, 1994 White, 1996; Wyllie et al. 1980) observed this type of behavior in tobacco and mammals. They attribute this to the case of autophagy or apoptosis programmed cell death. Cryns and Yuan (1998) have shown that autophagy is characterized by a decrease in mitochondrial membrane potential, intracellular acidification, massive proteolysis and DNA damage. We must complete these observations in a larger study in cell biology and biochemistry to better understand the phenomenon of colza cell autophagy and its relations with the spreading of industrial sludge rich in heavy metals. These transformations will have a significant impact on the colza oil produced by this type of culture and therefore an impact on the human body.

  11. Tetrandrine, an Activator of Autophagy, Induces Autophagic Cell Death via PKC-α Inhibition and mTOR-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Vincent Kam Wai Wong

    2017-06-01

    Full Text Available Emerging evidence suggests the therapeutic role of autophagic modulators in cancer therapy. This study aims to identify novel traditional Chinese medicinal herbs as potential anti-tumor agents through autophagic induction, which finally lead to autophagy mediated-cell death in apoptosis-resistant cancer cells. Using bioactivity-guided purification, we identified tetrandrine (Tet from herbal plant, Radix stephaniae tetrandrae, as an inducer of autophagy. Across a number of cancer cell lines, we found that breast cancer cells treated with tetrandrine show an increase autophagic flux and formation of autophagosomes. In addition, tetrandrine induces cell death in a panel of apoptosis-resistant cell lines that are deficient for caspase 3, caspase 7, caspase 3 and 7, or Bax-Bak respectively. We also showed that tetrandrine-induced cell death is independent of necrotic cell death. Mechanistically, tetrandrine induces autophagy that depends on mTOR inactivation. Furthermore, tetrandrine induces autophagy in a calcium/calmodulin-dependent protein kinase kinase-β (CaMKK-β, 5′ AMP-activated protein kinase (AMPK independent manner. Finally, by kinase profiling against 300 WT kinases and computational molecular docking analysis, we showed that tetrandrine is a novel PKC-α inhibitor, which lead to autophagic induction through PKC-α inactivation. This study provides detailed insights into the novel cytotoxic mechanism of an anti-tumor compound originated from the herbal plant, which may be useful in promoting autophagy mediated- cell death in cancer cell that is resistant to apoptosis.

  12. Progranulin causes adipose insulin resistance via increased autophagy resulting from activated oxidative stress and endoplasmic reticulum stress.

    Science.gov (United States)

    Guo, Qinyue; Xu, Lin; Li, Huixia; Sun, Hongzhi; Liu, Jiali; Wu, Shufang; Zhou, Bo

    2017-01-31

    Progranulin (PGRN) has recently emerged as an important regulator for insulin resistance. However, the direct effect of progranulin in adipose insulin resistance associated with the autophagy mechanism is not fully understood. In the present study, progranulin was administered to 3T3-L1 adipocytes and C57BL/6 J mice with/without specific inhibitors of oxidative stress and endoplasmic reticulum stress, and metabolic parameters, oxidative stress, endoplasmic reticulum stress and autophagy markers were assessed. Progranulin treatment increased iNOS expression, NO synthesis and ROS generation, and elevated protein expressions of CHOP, GRP78 and the phosphorylation of PERK, and caused a significant increase in Atg7 and LC3-II protein expression and a decreased p62 expression, and decreased insulin-stimulated tyrosine phosphorylation of IRS-1 and glucose uptake, demonstrating that progranulin activated oxidative stress and ER stress, elevated autophagy and induced insulin insensitivity in adipocytes and adipose tissue of mice. Interestingly, inhibition of iNOS and ER stress both reversed progranulin-induced stress response and increased autophagy, protecting against insulin resistance in adipocytes. Furthermore, the administration of the ER stress inhibitor 4-phenyl butyric acid reversed the negative effect of progranulin in vivo. Our findings showed the clinical potential of the novel adipokine progranulin in the regulation of insulin resistance, suggesting that progranulin might mediate adipose insulin resistance, at least in part, by inducing autophagy via activated oxidative stress and ER stress.

  13. Autophagy regulation revealed by SapM-induced block of autophagosome-lysosome fusion via binding RAB7

    International Nuclear Information System (INIS)

    Hu, Dong; Wu, Jing; Wang, Wan; Mu, Min; Zhao, Runpeng; Xu, Xuewei; Chen, Zhaoquan; Xiao, Jian; Hu, Fengyu; Yang, Yabo; Zhang, Rongbo

    2015-01-01

    The mechanism underlying autophagy alteration by mycobacterium tuberculosis remains unclear. Our previous study shows LpqH, a lipoprotein of mycobacterium tuberculosis, can cause autophagosomes accumulation in murine macrophages. It is well known that SapM, another virulence factor, plays an important role in blocking phagosome-endosome fusion. However, the mechanism that SapM interferes with autophagy remains poorly defined. In this study, we report that SapM suppresses the autophagy flux by blocking autophagosome fusion with lysosome. Exposure to SapM results in accumulations of autophagosomes and decreased co-localization of autophagosome with lysosome. Molecularly, Rab7, a small GTPase, is blocked by SapM through its CT domain and is prevented from involvement of autophagosome-lysosome fusion. In conclusion, our study reveals that SapM takes Rab7 as a previously unknown target to govern a distinct molecular mechanism underlying autophagosome-lysosome fusion, which may bring light to a new thought about developing potential drugs or vaccines against tuberculosis. - Highlights: • A mechanism for disrupting autophagosome-lysosome fusion induced by SapM. • Rab7 is involved in SapM-inhibited autophagy. • SapM interacts with Rab7 by CT-domain. • CT-domain is indispensable to SapM-inhibited autophagy

  14. Neferine reduces cisplatin-induced nephrotoxicity by enhancing autophagy via the AMPK/mTOR signaling pathway.

    Science.gov (United States)

    Li, Hui; Tang, Yuling; Wen, Long; Kong, Xianglong; Chen, Xuelian; Liu, Ping; Zhou, Zhiguo; Chen, Wenhang; Xiao, Chenggen; Xiao, Ping; Xiao, Xiangcheng

    2017-03-11

    Cisplatin is one of the most effective chemotherapeutic agents; however, its clinical use is limited by serious side effects of which nephrotoxicity is the most important. Nephrotoxicity induced by cisplatin is closely associated with autophagy reduction and caspase activation. In this study, we investigated whether neferine, an autophagy inducer, had a protective effect against cisplatin-induced nephrotoxicity. In an in vitro cisplatin-induced nephrotoxicity model, we determined that neferine was able to induce autophagy and that pretreatment with neferine not only attenuated cisplatin-induced cell apoptosis but further activated cell autophagy. This pro-survival effect was abolished by the autophagic flux inhibitor chloroquine. Furthermore, neferine pretreatment activated the AMPK/mTOR pathway; however, pharmacological inhibition of AMPK abolished neferine-mediated autophagy and nephroprotection against cisplatin-induced apoptosis. Collectively, our findings suggest for the first time the possible protective mechanism of neferine, which is crucial for its further development as a potential therapeutic agent for cisplatin-induced nephrotoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Autophagy regulation revealed by SapM-induced block of autophagosome-lysosome fusion via binding RAB7

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Dong, E-mail: austhudong@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Wu, Jing, E-mail: wujing8008@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Wang, Wan; Mu, Min; Zhao, Runpeng; Xu, Xuewei; Chen, Zhaoquan [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Xiao, Jian [School of Pharmacy, Wenzhou Medical College, Wenzhou (China); Hu, Fengyu; Yang, Yabo [Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou (China); Zhang, Rongbo, E-mail: lory456@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China)

    2015-05-29

    The mechanism underlying autophagy alteration by mycobacterium tuberculosis remains unclear. Our previous study shows LpqH, a lipoprotein of mycobacterium tuberculosis, can cause autophagosomes accumulation in murine macrophages. It is well known that SapM, another virulence factor, plays an important role in blocking phagosome-endosome fusion. However, the mechanism that SapM interferes with autophagy remains poorly defined. In this study, we report that SapM suppresses the autophagy flux by blocking autophagosome fusion with lysosome. Exposure to SapM results in accumulations of autophagosomes and decreased co-localization of autophagosome with lysosome. Molecularly, Rab7, a small GTPase, is blocked by SapM through its CT domain and is prevented from involvement of autophagosome-lysosome fusion. In conclusion, our study reveals that SapM takes Rab7 as a previously unknown target to govern a distinct molecular mechanism underlying autophagosome-lysosome fusion, which may bring light to a new thought about developing potential drugs or vaccines against tuberculosis. - Highlights: • A mechanism for disrupting autophagosome-lysosome fusion induced by SapM. • Rab7 is involved in SapM-inhibited autophagy. • SapM interacts with Rab7 by CT-domain. • CT-domain is indispensable to SapM-inhibited autophagy.

  16. Exogenous hydrogen sulfide promotes cell proliferation and differentiation by modulating autophagy in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xin [Department of Dermatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, Heilongjiang Province (China); Dai, Hui [Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang Province (China); Zhuang, Binyu [Department of Dermatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, Heilongjiang Province (China); Chai, Li; Xie, Yanguang [Institute of Dermatology of Heilongjiang Province, Harbin, 150001, Heilongjiang Province (China); Li, Yuzhen, E-mail: liyuzhen@medmail.com.cn [Department of Dermatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, Heilongjiang Province (China)

    2016-04-08

    The effects and the underlying mechanisms of hydrogen sulfide (H{sub 2}S) on keratinocyte proliferation and differentiation are still less known. In the current study, we investigated the effects and the underlying mechanisms of exogenous H{sub 2}S on keratinocyte proliferation and differentiation. Human keratinocytes (HaCaT cells) were treated with various concentrations (0.05, 0.25, 0.5 and 1 mM) of sodium hydrosulfide (NaHS, a donor of H{sub 2}S) for 24 h. A CCK-8 assay was used to assess cell viability. Western blot analysis was performed to determine the expression levels of proteins associated with differentiation and autophagy. Transmission electron microscopy was performed to observe autophagic vacuoles, and flow cytometry was applied to evaluate apoptosis. NaHS promoted the viability, induced the differentiation, and enhanced autophagic activity in a dose-dependent manner in HaCaT cells but had no effect on cell apoptosis. Blockage of autophagy by ATG5 siRNA inhibited NaHS-induced cell proliferation and differentiation. The current study demonstrated that autophagy in response to exogenous H{sub 2}S treatment promoted keratinocyte proliferation and differentiation. Our results provide additional insights into the potential role of autophagy in keratinocyte proliferation and differentiation. - Highlights: • Exogenous H{sub 2}S promotes keratinocyte proliferation and differentiation. • The effects of H{sub 2}S on proliferation and differentiation is modulated by autophagy. • Exogenous H{sub 2}S has no effect on keratinocyte apoptosis.

  17. Spliced XBP1 promotes macrophage survival and autophagy by interacting with Beclin-1

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Ping-Ge [Southern Medical University, Guangzhou, Guangdong 510515 (China); Jiang, Zhi-Xin [Centre Laboratory, The 305th Hospital of the People' s Liberation Army, Beijing 100017 (China); Li, Jian-Hua [Department of Geriatric Cardiology, Chinese PLA General Hosptial, Beijing 100853 (China); Zhou, Zhe, E-mail: zhouzhe76@126.com [Laboratory of Biotechnology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Zhang, Qing-Hua, E-mail: 1056055170@qq.com [Department of Cardiology, The 305th Hospital of the People' s Liberation Army, Beijing 100017 (China)

    2015-08-07

    Macrophage autophagy plays an important role in the development of atherosclerosis, but the precise mechanism mediating this process is unclear. The potential role of the X-box binding protein 1 (XBP1), a crucial transduction factor that is involved in endoplasmic reticulum stress and the unfolded protein response, in bone marrow-derived macrophage autophagy is unknown. This study mainly explores the roles of XBP1 mRNA splicing in bone marrow-derived macrophage autophagy. The present study shows that the transient overexpression of spliced XBP1 via adenovirus-mediated gene transfer induces autophagy and promotes proliferation in bone marrow-derived macrophages via the down-regulation of Beclin-1, but that the sustained overexpression of spliced XBP1 leads to apoptosis. When XBP1 is down-regulated in bone marrow-derived macrophages using siRNA, rapamycin-induced autophagosome formation is ablated. Furthermore, we have detected the overexpression of XBP1 in areas of atherosclerotic plaques in the arteries of ApoE−/− mice. These results demonstrate that XBP1 mRNA splicing plays an important role in maintaining the function of bone marrow-derived macrophages and provide new insight into the study and treatment of atherosclerosis. - Highlights: • XBP1 was up-regulated in atherosclerotic plaques of ApoE−/− mice. • Transient spliced XBP1 overexpression induced macrophages autophagy via Beclin-1. • Sustained spliced XBP1 overexpression triggered macrophages apoptosis. • Spliced XBP1 plays a key role in maintaining the macrophages survival.

  18. Autophagy failure in Alzheimer's disease and the role of defective lysosomal acidification.

    Science.gov (United States)

    Wolfe, Devin M; Lee, Ju-Hyun; Kumar, Asok; Lee, Sooyeon; Orenstein, Samantha J; Nixon, Ralph A

    2013-06-01

    Autophagy is a lysosomal degradative process which recycles cellular waste and eliminates potentially toxic damaged organelles and protein aggregates. The important cytoprotective functions of autophagy are demonstrated by the diverse pathogenic consequences that may stem from autophagy dysregulation in a growing number of neurodegenerative disorders. In many of the diseases associated with autophagy anomalies, it is the final stage of autophagy-lysosomal degradation that is disrupted. In several disorders, including Alzheimer's disease (AD), defective lysosomal acidification contributes to this proteolytic failure. The complex regulation of lysosomal pH makes this process vulnerable to disruption by many factors, and reliable lysosomal pH measurements have become increasingly important in investigations of disease mechanisms. Although various reagents for pH quantification have been developed over several decades, they are not all equally well suited for measuring the pH of lysosomes. Here, we evaluate the most commonly used pH probes for sensitivity and localisation, and identify LysoSensor yellow/blue-dextran, among currently used probes, as having the optimal profile of properties for measuring lysosomal pH. In addition, we review evidence that lysosomal acidification is defective in AD and extend our original findings, of elevated lysosomal pH in presenilin 1 (PS1)-deficient blastocysts and neurons, to additional cell models of PS1 and PS1/2 deficiency, to fibroblasts from AD patients with PS1 mutations, and to neurons in the PS/APP mouse model of AD. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  19. The roles of autophagy and hypoxia in human inflammatory periapical lesions.

    Science.gov (United States)

    Huang, H Y; Wang, W C; Lin, P Y; Huang, C P; Chen, C Y; Chen, Y K

    2018-02-01

    To determine the expressions of hypoxia-related [hypoxia-inducible transcription factors (HIF)-1α, BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) and phospho-adenosine monophosphate activated protein kinase (pAMPK)] and autophagy-related [microtubule-associated protein 1 light chain 3 (LC3), beclin-1 (BECN-1), autophagy-related gene (Atg)5-12, and p62] proteins in human inflammatory periapical lesions. Fifteen samples of radicular cysts (RCs) and 21 periapical granulomas (PGs), combined with 17 healthy dental pulp tissues, were examined. Enzyme-linked immunosorbent assay (ELISA) was used to detect interleukin (IL)-1β cytokine; immunohistochemical (IHC) and Western blot (WB) analyses were employed to examine autophagy-related and hypoxia-related proteins. Transmission electron microscopy (TEM) was used to explore the ultrastructural morphology of autophagy in periapical lesions. Nonparametric Kruskal-Wallis tests and Mann-Whitney U-tests were used for statistical analyses. ELISA revealed a significantly higher (P periapical lesions than in normal pulp tissue. Immunoscores of IHC expressions of pAMPK, HIF-1α, BNIP3, BECN-1 and Atg5-12 proteins in periapical lesions were significantly higher (P periapical lesions were noted as compared to normal pulp tissue. Upon TEM, ultrastructural double-membrane autophagosomes and autolysosomes were observed in PGs and RCs. Autophagy associated with hypoxia may play a potential causative role in the development and maintenance of inflamed periapical lesions. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  20. Facilitated ethanol metabolism promotes cardiomyocyte contractile dysfunction through autophagy in murine hearts.

    Science.gov (United States)

    Guo, Rui; Hu, Nan; Kandadi, Machender R; Ren, Jun

    2012-04-01

    Chronic drinking leads to myocardial contractile dysfunction where ethanol metabolism plays an essential role. Acetaldehyde, the main ethanol metabolite, mediates alcohol-induced cell injury although the underlying mechanism is still elusive. This study was designed to examine the mechanism involved in accelerated ethanol metabolism-induced cardiac defect with a focus on autophagy. Wild-type FVB and cardiac-specific overexpression of alcohol dehydrogenase mice were placed on a 4% nutrition-balanced alcohol diet for 8 weeks. Myocardial histology, immunohistochemistry, autophagy markers and signal molecules were examined. Expression of micro RNA miR-30a, a potential target of Beclin 1, was evaluated by real-time PCR. Chronic alcohol intake led to cardiac acetaldehyde accumulation, hypertrophy and overt autophagosome accumulation (LC3-II and Atg7), the effect of which was accentuated by ADH. Signaling molecules governing autophagy initiation including class III PtdIns3K, phosphorylation of mTOR and p70S6K were enhanced and dampened, respectively, following alcohol intake. These alcohol-induced signaling responses were augmented by ADH. ADH accentuated or unmasked alcohol-induced downregulation of Bcl-2, Bcl-xL and MiR-30a. Interestingly, ADH aggravated alcohol-induced p62 accumulation. Autophagy inhibition using 3-MA abolished alcohol-induced cardiomyocyte contractile anomalies. Moreover, acetaldehyde led to cardiomyocyte contractile dysfunction and autophagy induction, which was ablated by 3-MA. Ethanol or acetaldehyde increased GFP-LC3 puncta in H9c2 cells, the effect of which was ablated by 3-MA but unaffected by lysosomal inhibition using bafilomycin A(1), E64D and pepstatin A. In summary, these data suggested that facilitated acetaldehyde production via ADH following alcohol intake triggered cardiac autophagosome formation along with impaired lysosomal degradation, en route to myocardial defect.

  1. Arsenite-induced autophagy is associated with proteotoxicity in human lymphoblastoid cells

    Energy Technology Data Exchange (ETDEWEB)

    Bolt, Alicia M.; Zhao, Fei; Pacheco, Samantha; Klimecki, Walter T., E-mail: klimecki@pharmacy.arizona.edu

    2012-10-15

    Epidemiological studies of arsenic-exposed populations have provided evidence that arsenic exposure in humans is associated with immunosuppression. Previously, we have reported that arsenite-induced toxicity is associated with the induction of autophagy in human lymphoblastoid cell lines (LCL). Autophagy is a cellular process that functions in the degradation of damaged cellular components, including protein aggregates formed by misfolded or damaged proteins. Accumulation of misfolded or damaged proteins in the endoplasmic reticulum (ER) lumen causes ER stress and activates the unfolded protein response (UPR). In an effort to investigate the mechanism of autophagy induction by arsenite in the LCL model, we examined the potential contribution of ER stress and activation of the UPR. LCL exposed to sodium arsenite for 8-days induced expression of UPR-activated genes, including CHOP and GRP78, at the RNA and the protein level. Evidence for activation of the three arms of the UPR was observed. The arsenite-induced activation of the UPR was associated with an accumulation of protein aggregates containing p62 and LC3, proteins with established roles in the sequestration and autophagic clearance of protein aggregates. Taken together, these data provide evidence that arsenite-induced autophagy is associated with the generation of ER stress, activation of the UPR, and formation of protein aggregates that may be targeted to the lysosome for degradation. -- Highlights: ► Arsenite induces endoplasmic reticulum stress and the unfolded protein response. ► Arsenite induces the formation of protein aggregates that contain p62 and LC3-II. ► Time-course data suggests that arsenite-induced autophagy precedes ER stress.

  2. Glucocorticoids induce autophagy in rat bone marrow mesenchymal stem cells

    DEFF Research Database (Denmark)

    Wang, L.; Fan, J.; Lin, Y. S.

    2015-01-01

    Glucocorticoidinduced osteoporosis (GIOP) is a widespread clinical complication following glucocorticoid therapy. This irreversible damage to boneforming and resorbing cells is essential in the pathogenesis of osteoporosis. Autophagy is a physiological process involved in the regulation of cells...... and their responses to diverse stimuli, however, the role of autophagy in glucocorticoidinduced damage to bone marrow mesenchymal stem cells (BMSCs) remains unclear. The current study confirmed that glucocorticoid administration impaired the proliferation of BMSCs. Transmission electron microscopy...... that in response to glucocorticoid administration, induced autophagy aids to maintain proliferation and prevent apoptosis of BMSCs. Thus, it is hypothesized that autophagy may be a novel target in the treatment or prevention of osteoporosis....

  3. Response to the call by DCMS for views on the potential implications of Brexit for Data Protection stakeholders: Brexit: Potential Implications for Digital and ‘Fintech’ Industries

    OpenAIRE

    Mc Cullagh, Karen

    2016-01-01

    Following the outcome of the historic ‘Brexit’ referendum on 23rd June 2016 in which a majority of eligible voters in the UK voted to ‘Leave,’[1] the United Kingdom is potentially on course to leave the European Union,[2] but to ensure continued economic success it will seek to maintain a favourable trading relationship with the EU. This article identifies and critically evaluates the various types of trade deals the UK might negotiate upon exit with a particular focus on trade in services si...

  4. Dysregulation of Autophagy Contributes to Anal Carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Evie H Carchman

    Full Text Available Autophagy is an intracellular catabolic process that removes and recycles unnecessary/dysfunctional cellular components, contributing to cellular health and survival. Autophagy is a highly regulated cellular process that responds to several intracellular signals, many of which are deregulated by human papillomavirus (HPV infection through the expression of HPV-encoded oncoproteins. This adaptive inhibitory response helps prevent viral clearance. A strong correlation remains between HPV infection and the development of squamous cell carcinoma (SCC of the anus, particularly in HIV positive and other immunosuppressed patients. We hypothesize that autophagy is inhibited by HPV-encoded oncoproteins thereby promoting anal carcinogenesis (Fig 1.HPV16 transgenic mice (K14E6/E7 and non-transgenic mice (FVB/N, both of which do not spontaneously develop anal tumors, were treated topically with the chemical carcinogen, 7,12-Dimethylbenz[a]anthracene (DMBA, to induce anal cancer. The anuses at different time points of treatment (5, 10, 15 and 20 weeks were analyzed using immunofluorescence (IF for two key autophagy marker proteins (LC3β and p62 in addition to histological grading. The anuses from the K14E6/E7 mice were also analyzed for visual evidence of autophagic activity by electron microscopy (EM. To see if there was a correlation to humans, archival anal specimens were assessed histologically for grade of dysplasia and then analyzed for LC3β and p62 protein content. To more directly examine the effect of autophagic inhibition on anal carcinogenesis, nontransgenic mice that do not develop anal cancer with DMBA treatment were treated with a known pharmacologic inhibitor of autophagy, chloroquine, and examined for tumor development and analyzed by IF for autophagic proteins.Histologically, we observed the progression of normal anoderm to invasive SCC with DMBA treatment in K14E6/E7 mice but not in nontransgenic, syngeneic FVB/N background control mice

  5. Autophagy and phagocytosis converge for better vision.

    Science.gov (United States)

    Ferguson, Thomas A; Green, Douglas R

    2014-01-01

    The retinal pigment epithelium (RPE) is a single layer of nonregenerating cells essential to homeostasis in the retina and the preservation of vision. While the RPE perform a number of important functions, 2 essential processes are phagocytosis, which removes the most distal tips of the photoreceptors to support disk renewal, and the visual cycle, which maintains the supply of chromophore for regeneration of photo-bleached visual pigments. We recently reported that these processes are linked by a noncanonical form of autophagy termed LC3-associated phagocytosis (LAP) in which components of the autophagy pathway are co-opted by phagocytosis to recover vitamin A in support of optimal vision. Here we summarize these findings.

  6. Quiltophagy--autophagy as folk art.

    Science.gov (United States)

    Crumrine, Barbara M; Klionsky, Daniel J

    2015-01-01

    Over the years macroautophagy (hereafter autophagy) has been depicted artistically through painting, music, dance, videos, and poetry. A unifying idea behind these different aesthetic approaches is that people learn in different ways. Thus, some learners may be engaged by a detailed, but static, painting, whereas others may find insight through the dynamic visualization provided by a dance. While each of these formats has advantages, they also have a common weakness--whether delivered through watercolor on a canvas, words on a paper, or movement captured in a video, they are all 2-dimensional. Yet, some people are tactile learners. In this paper, a quilter describes a project she created with the goal of demonstrating autophagy using a 3-dimensional approach, in which different fiber textures could be used to elaborate certain parts of the process.

  7. Autophagy as an ultrastructural marker of heavy metal toxicity in human cord blood hematopoietic stem cells

    International Nuclear Information System (INIS)

    Di Gioacchino, Mario; Petrarca, Claudia; Perrone, Angela; Farina, Massimo; Sabbioni, Enrico; Hartung, Thomas; Martino, Simone; Esposito, Diana L.; Lotti, Lavinia Vittoria; Mariani-Costantini, Renato

    2008-01-01

    Stem cells are a key target of environmental toxicants, but little is known about their toxicological responses. We aimed at developing an in-vitro model based on adult human stem cells to identify biomarkers of heavy metal exposure. To this end we investigated the responses of human CD34+ hematopoietic progenitor cells to hexavalent chromium (Cr[VI]) and cadmium (Cd). Parallel cultures of CD34+ cells isolated from umbilical cord blood were exposed for 48 h to 0.1 μM and 10 μM Cr(VI) or Cd. Cultures treated with 10 μM Cr(VI) or Cd showed marked cell loss. Ultrastructural analysis of surviving cells revealed prominent autophagosomes/autophagolysosomes, which is diagnostic of autophagy, associated with mitochondrial damage and replication, dilatation of the rough endoplasmic reticulum and Golgi complex, cytoplasmic lipid droplets and chromatin condensation. Treated cells did not show the morphologic hallmarks of apoptosis. Treatment with 0.1 μM Cr(VI) or Cd did not result in cell loss, but at the ultrastructural level cells showed dilated endoplasmic reticulum and evidence of mitochondrial damage. We conclude that autophagy is implicated in the response of human hematopoietic stem cells to toxic concentrations of Cr(VI) and Cd. Autophagy, which mediates cell survival and death under stress, deserves further evaluation to be established as biomarker of metal exposure

  8. Interleukin-6 Reduces β-Cell Oxidative Stress by Linking Autophagy With the Antioxidant Response.

    Science.gov (United States)

    Marasco, Michelle R; Conteh, Abass M; Reissaus, Christopher A; Cupit V, John E; Appleman, Evan M; Mirmira, Raghavendra G; Linnemann, Amelia K

    2018-05-21

    Production of reactive oxygen species (ROS) is a key instigator of β-cell dysfunction in diabetes. The pleiotropic cytokine IL-6 has previously been linked to β-cell autophagy but has not been studied in the context of β-cell antioxidant response. We used a combination of animal models of diabetes and analysis of cultured human islets and rodent β-cells to study how IL-6 influences antioxidant response. We show that IL-6 couples autophagy to antioxidant response to reduce β-cell and human islet ROS. β cell-specific loss of IL-6 signaling in vivo renders mice more susceptible to oxidative damage and cell death by the selective β-cell toxins streptozotocin and alloxan. IL-6-driven ROS reduction is associated with an increase in the master antioxidant factor NRF2, which rapidly translocates to the mitochondria to decrease mitochondrial activity and stimulate mitophagy. IL-6 also initiates a robust transient drop in cellular cAMP, likely contributing to the stimulation of mitophagy for ROS mitigation. Our findings suggest that coupling autophagy to antioxidant response in the β cell leads to stress adaptation that can reduce cellular apoptosis. These findings have implications for β-cell survival under diabetogenic conditions and present novel targets for therapeutic intervention. © 2018 by the American Diabetes Association.

  9. Autophagy as an ultrastructural marker of heavy metal toxicity in human cord blood hematopoietic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Di Gioacchino, Mario [Aging Research Center, ' G. d' Annunzio' University Foundation, Via Colle dell' Ara, 66100 Chieti (Italy); Medicine and Science of Ageing University of Chieti-Pescara, Via dei Vestini 1, 66100 Chieti (Italy)], E-mail: m.digioacchino@unich.it; Petrarca, Claudia; Perrone, Angela [Aging Research Center, ' G. d' Annunzio' University Foundation, Via Colle dell' Ara, 66100 Chieti (Italy); Medicine and Science of Ageing University of Chieti-Pescara, Via dei Vestini 1, 66100 Chieti (Italy); Farina, Massimo; Sabbioni, Enrico; Hartung, Thomas [Oncology and Neurosciences University of Chieti-Pescara, Via dei Vestini 1, 66100 Chieti (Italy); Martino, Simone [Department of Experimental Medicine, University La Sapienza, Viale Regina Elena 324, 00161 Rome (Italy); Esposito, Diana L. [Aging Research Center, ' G. d' Annunzio' University Foundation, Via Colle dell' Ara, 66100 Chieti (Italy); Oncology and Neurosciences University of Chieti-Pescara, Via dei Vestini 1, 66100 Chieti (Italy); Lotti, Lavinia Vittoria [Department of Experimental Medicine, University La Sapienza, Viale Regina Elena 324, 00161 Rome (Italy); Mariani-Costantini, Renato [Aging Research Center, ' G. d' Annunzio' University Foundation, Via Colle dell' Ara, 66100 Chieti (Italy); Oncology and Neurosciences University of Chieti-Pescara, Via dei Vestini 1, 66100 Chieti (Italy)

    2008-03-15

    Stem cells are a key target of environmental toxicants, but little is known about their toxicological responses. We aimed at developing an in-vitro model based on adult human stem cells to identify biomarkers of heavy metal exposure. To this end we investigated the responses of human CD34+ hematopoietic progenitor cells to hexavalent chromium (Cr[VI]) and cadmium (Cd). Parallel cultures of CD34+ cells isolated from umbilical cord blood were exposed for 48 h to 0.1 {mu}M and 10 {mu}M Cr(VI) or Cd. Cultures treated with 10 {mu}M Cr(VI) or Cd showed marked cell loss. Ultrastructural analysis of surviving cells revealed prominent autophagosomes/autophagolysosomes, which is diagnostic of autophagy, associated with mitochondrial damage and replication, dilatation of the rough endoplasmic reticulum and Golgi complex, cytoplasmic lipid droplets and chromatin condensation. Treated cells did not show the morphologic hallmarks of apoptosis. Treatment with 0.1 {mu}M Cr(VI) or Cd did not result in cell loss, but at the ultrastructural level cells showed dilated endoplasmic reticulum and evidence of mitochondrial damage. We conclude that autophagy is implicated in the response of human hematopoietic stem cells to toxic concentrations of Cr(VI) and Cd. Autophagy, which mediates cell survival and death under stress, deserves further evaluation to be established as biomarker of metal exposure.

  10. Functional variant in the autophagy-related 5 gene promotor is associated with childhood asthma.

    Directory of Open Access Journals (Sweden)

    Lisa J Martin

    Full Text Available Autophagy is a cellular process directed at eliminating or recycling cellular proteins. Recently, the autophagy pathway has been implicated in immune dysfunction, the pathogenesis of inflammatory disorders, and response to viral infection. Associations between two genes in the autophagy pathway, ATG5 and ATG7, with childhood asthma were investigated.Using genetic and experimental approaches, we examined the association of 13 HapMap-derived tagging SNPs in ATG5 and ATG7 with childhood asthma in 312 asthmatic and 246 non-allergic control children. We confirmed our findings by using independent cohorts and imputation analysis. Finally, we evaluated the functional relevance of a disease associated SNP.We demonstrated that ATG5 single nucleotide polymorphisms rs12201458 and rs510432 were associated with asthma (p = 0.00085 and 0.0025, respectively. In three independent cohorts, additional variants in ATG5 in the same LD block were associated with asthma (p<0.05. We found that rs510432 was functionally relevant and conferred significantly increased promotor activity. Furthermore, Atg5 expression was increased in nasal epithelium of acute asthmatics compared to stable asthmatics and non-asthmatic controls.Genetic variants in ATG5, including a functional promotor variant, are associated with childhood asthma. These results provide novel evidence for a role for ATG5 in childhood asthma.

  11. Loss of Autophagy in Proopiomelanocortin Neurons Perturbs Axon Growth and Causes Metabolic Dysregulation

    Science.gov (United States)

    Coupé, Bérengère; Ishii, Yuko; Dietrich, Marcelo O; Komatsu, Masaaki; Horvath, Tamas L.; Bouret, Sebastien G.

    2012-01-01

    Summary The hypothalamic melanocortin system, which includes neurons that produce proopiomelanocortin (POMC)-derived peptides, is a major negative regulator of energy balance. POMC neurons begin to acquire their unique properties during neonatal life. The formation of functional neural systems requires massive cytoplasmic remodeling that may involve autophagy, an important intracellular mechanism for the degradation of damaged proteins and organelles. Here we investigated the functional and structural effects of the deletion of an essential autophagy gene, Atg7, in POMC neurons. Lack of Atg7 in POMC neurons caused higher post-weaning body weight, increased adiposity, and glucose intolerance. These metabolic impairments were associated with an age-dependant accumulation of ubiquitin/p62-positive aggregates in the hypothalamus and a disruption in the maturation of POMC-containing axonal projections. Together, these data provide direct genetic evidence that Atg7 in POMC neurons is required for normal metabolic regulation and neural development, and they implicate hypothalamic autophagy deficiency in the pathogenesis of obesity. PMID:22285542

  12. Salinomycin induces autophagy in colon and breast cancer cells with concomitant generation of reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Berlinda Verdoodt

    Full Text Available BACKGROUND: Salinomycin is a polyether ionophore antibiotic that has recently been shown to induce cell death in human cancer cells displaying multiple mechanisms of drug resistance. The underlying mechanisms leading to cell death after salinomycin treatment have not been well characterized. We therefore investigated the role of salinomycin in caspase dependent and independent cell death in colon cancer (SW480, SW620, RKO and breast cancer cell lines (MCF-7, T47D, MDA-MB-453. METHODOLOGY/PRINCIPAL FINDINGS: We detected features of apoptosis in all cell lines tested, but the executor caspases 3 and 7 were only strongly activated in RKO and MDA-MB-453 cells. MCF-7 and SW620 cells instead presented features of autophagy such as cytoplasmic vacuolization and LC3 processing. Caspase proficient cell lines activated autophagy at lower salinomycin concentrations and before the onset of caspase activation. Salinomycin also led to the formation of reactive oxygen species (ROS eliciting JNK activation and induction of the transcription factor JUN. Salinomycin mediated cell death could be partially inhibited by the free radical scavenger N-acetyl-cysteine, implicating ROS formation in the mechanism of salinomycin toxicity. CONCLUSIONS: Our data indicate that, in addition to its previously reported induction of caspase dependent apoptosis, the initiation of autophagy is an important and early effect of salinomycin in tumor cells.

  13. Loss of autophagy in pro-opiomelanocortin neurons perturbs axon growth and causes metabolic dysregulation.

    Science.gov (United States)

    Coupé, Bérengère; Ishii, Yuko; Dietrich, Marcelo O; Komatsu, Masaaki; Horvath, Tamas L; Bouret, Sebastien G

    2012-02-08

    The hypothalamic melanocortin system, which includes neurons that produce pro-opiomelanocortin (POMC)-derived peptides, is a major negative regulator of energy balance. POMC neurons begin to acquire their unique properties during neonatal life. The formation of functional neural systems requires massive cytoplasmic remodeling that may involve autophagy, an important intracellular mechanism for the degradation of damaged proteins and organelles. Here we investigated the functional and structural effects of the deletion of an essential autophagy gene, Atg7, in POMC neurons. Lack of Atg7 in POMC neurons caused higher postweaning body weight, increased adiposity, and glucose intolerance. These metabolic impairments were associated with an age-dependent accumulation of ubiquitin/p62-positive aggregates in the hypothalamus and a disruption in the maturation of POMC-containing axonal projections. Together, these data provide direct genetic evidence that Atg7 in POMC neurons is required for normal metabolic regulation and neural development, and they implicate hypothalamic autophagy deficiency in the pathogenesis of obesity. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. A Molecular View of Autophagy in Lepidoptera

    OpenAIRE

    Romanelli, Davide; Casati, Barbara; Franzetti, Eleonora; Tettamanti, Gianluca

    2014-01-01

    Metamorphosis represents a critical phase in the development of holometabolous insects, during which the larval body is completely reorganized: in fact, most of the larval organs undergo remodeling or completely degenerate before the final structure of the adult insect is rebuilt. In the past, increasing evidence emerged concerning the intervention of autophagy and apoptosis in the cell death processes that occur in larval organs of Lepidoptera during metamorphosis, but a molecular characteri...

  15. A large-scale RNA interference screen identifies genes that regulate autophagy at different stages.

    Science.gov (United States)

    Guo, Sujuan; Pridham, Kevin J; Virbasius, Ching-Man; He, Bin; Zhang, Liqing; Varmark, Hanne; Green, Michael R; Sheng, Zhi

    2018-02-12

    Dysregulated autophagy is central to the pathogenesis and therapeutic development of cancer. However, how autophagy is regulated in cancer is not well understood and genes that modulate cancer autophagy are not fully defined. To gain more insights into autophagy regulation in cancer, we performed a large-scale RNA interference screen in K562 human chronic myeloid leukemia cells using monodansylcadaverine staining, an autophagy-detecting approach equivalent to immunoblotting of the autophagy marker LC3B or fluorescence microscopy of GFP-LC3B. By coupling monodansylcadaverine staining with fluorescence-activated cell sorting, we successfully isolated autophagic K562 cells where we identified 336 short hairpin RNAs. After candidate validation using Cyto-ID fluorescence spectrophotometry, LC3B immunoblotting, and quantitative RT-PCR, 82 genes were identified as autophagy-regulating genes. 20 genes have been reported previously and the remaining 62 candidates are novel autophagy mediators. Bioinformatic analyses revealed that most candidate genes were involved in molecular pathways regulating autophagy, rather than directly participating in the autophagy process. Further autophagy flux assays revealed that 57 autophagy-regulating genes suppressed autophagy initiation, whereas 21 candidates promoted autophagy maturation. Our RNA interference screen identifies identified genes that regulate autophagy at different stages, which helps decode autophagy regulation in cancer and offers novel avenues to develop autophagy-related therapies for cancer.

  16. Indoor and outdoor airborne particles : an in vitro study on mutagenic potential and toxicological implications

    NARCIS (Netherlands)

    Houdt, van J.J.

    1988-01-01

    Introduction

    Air pollution components are present as gases and as particulate matter. As particle deposition takes place in various parts of the respiratory system particulate matter may have other toxicological implications than gaseous pollutants, which all may

  17. The Future Nuclear Arms Control Agenda and Its Potential Implications for the Air Force

    Science.gov (United States)

    2015-08-01

    US AIR FORCE INSTITUTE FOR NATIONAL SECURITY STUDIES USAF ACADEMY, COLORADO INSS OCCASIONAL PAPER AUGUST 2015 70 Dr. Lewis A. Dunn The Future...Implications for the Air Force Dr. Lewis A. Dunn INSS Occasional Paper 70 August 2015 USAF Institute for National Security Studies USAF

  18. Volunteering for College? Potential Implications of Financial Aid Tax Credits Rewarding Community Service

    Science.gov (United States)

    Wells, Ryan S.; Lynch, Cassie M.

    2014-01-01

    President Obama has proposed a financial aid policy whereby students who complete 100 hours of community service would receive a tax credit of US$4,000 for college. After lawmakers cut this proposal from previous legislation, the administration was tasked with studying the feasibility of implementation. However, the implications of the policy for…

  19. β-Cell Autophagy in Diabetes Pathogenesis.

    Science.gov (United States)

    Marasco, Michelle R; Linnemann, Amelia K

    2018-05-01

    Nearly 100 years have passed since Frederick Banting and Charles Best first discovered and purified insulin. Their discovery and subsequent improvements revolutionized the treatment of diabetes, and the field continues to move at an ever-faster pace with respect to unique treatments for both type 1 and type 2 diabetes. Despite these advances, we still do not fully understand how apoptosis of the insulin-producing β-cells is triggered, presenting a challenge in the development of preventative measures. In recent years, the process of autophagy has generated substantial interest in this realm due to discoveries highlighting its clear role in the maintenance of cellular homeostasis. As a result, the number of studies focused on islet and β-cell autophagy has increased substantially in recent years. In this review, we will discuss what is currently known regarding the role of β-cell autophagy in type 1 and type 2 diabetes pathogenesis, with an emphasis on new and exciting developments over the past 5 years. Further, we will discuss how these discoveries might be translated into unique treatments in the coming years.

  20. Hypoxia-Induced Autophagy Is Mediated through Hypoxia-Inducible Factor Induction of BNIP3 and BNIP3L via Their BH3 Domains▿ †

    OpenAIRE

    Bellot, Grégory; Garcia-Medina, Raquel; Gounon, Pierre; Chiche, Johanna; Roux, Danièle; Pouysségur, Jacques; Mazure, Nathalie M.

    2009-01-01

    While hypoxia-inducible factor (HIF) is a major actor in the cell survival response to hypoxia, HIF also is associated with cell death. Several studies implicate the HIF-induced putative BH3-only proapoptotic genes bnip3 and bnip3l in hypoxia-mediated cell death. We, like others, do not support this assertion. Here, we clearly demonstrate that the hypoxic microenvironment contributes to survival rather than cell death by inducing autophagy. The ablation of Beclin1, a major actor of autophagy,...

  1. SIRT1 protects cardiac cells against apoptosis induced by zearalenone or its metabolites α- and β-zearalenol through an autophagy-dependent pathway

    International Nuclear Information System (INIS)

    Ben Salem, Intidhar; Boussabbeh, Manel; Da Silva, Julie Pires; Guilbert, Arnaud; Bacha, Hassen; Abid-Essefi, Salwa; Lemaire, Christophe

    2017-01-01

    Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium in cereals and agricultural products. The major ZEN metabolites are α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL). In the present study, we investigated the underlying mechanism of the toxicity induced by ZEN, α-ZOL and β-ZOL in cardiac cells (H9c2). We show that treatment with ZEN or its metabolites induces the activation of the mitochondrial pathway of apoptosis as characterized by an increase in ROS generation, a loss of mitochondrial transmembrane potential (ΔΨm) and an activation of caspases. Besides, we demonstrate that these mycotoxins promote the activation of autophagy before the onset of apoptosis. Indeed, we observed that a short-time (6 h) treatment with ZEN, α-ZOL or β-ZOL, increased the level of Beclin-1 and LC3-II and induced the accumulation of the CytoID® autophagy detection probe. Moreover, the inhibition of autophagy by Chloroquine significantly increased cell death induced by ZEN, α-ZOL or β-ZOL, suggesting that the activation of autophagy serves as a cardioprotective mechanism against these mycotoxins. In addition, we found that the inhibition (EX527) or the knockdown of SIRT1 (siRNA) significantly increased apoptosis induced by ZEN or its derivatives, whereas SIRT1 activation with RSV greatly prevents the cytotoxic effects of these mycotoxins. By contrast, when autophagy was inhibited by CQ, the activation of SIRT1 by RSV had no protection against the cardiotoxicity of ZEN or its metabolites, suggesting that SIRT1 protects cardiac cells by an autophagy-dependent pathway. - Highlights: • ZEN, α- and β-ZOL induce the mitochondrial pathway of apoptosis in cardiac cells. • Inhibition of autophagy enhanced ZEN-, α-ZOL- and β-ZOL-induced apoptosis. • SIRT1 activates autophagy to protect cells from ZEN, α- and β-ZOL-induced toxicity.

  2. MicroRNA 17-5p regulates autophagy in Mycobacterium tuberculosis-infected macrophages by targeting Mcl-1 and STAT3.

    Science.gov (United States)

    Kumar, Ranjeet; Sahu, Sanjaya Kumar; Kumar, Manish; Jana, Kuladip; Gupta, Pushpa; Gupta, Umesh D; Kundu, Manikuntala; Basu, Joyoti

    2016-05-01

    Autophagy plays a crucial role in the control of bacterial burden during Mycobacterium tuberculosis infection. MicroRNAs (miRNAs) are small non-coding RNAs that regulate immune signalling and inflammation in response to challenge by pathogens. Appreciating the potential of host-directed therapies designed to control autophagy during mycobacterial infection, we focused on the role of miRNAs in regulating M. tuberculosis-induced autophagy in macrophages. Here, we demonstrate that M. tuberculosis infection leads to downregulation of miR-17 and concomitant upregulation of its targets Mcl-1 and STAT3, a transcriptional activator of Mcl-1. Forced expression of miR-17 reduces expression of Mcl-1 and STAT3 and also the interaction between Mcl-1 and Beclin-1. This is directly linked to enhanced autophagy, because Mcl-1 overexpression attenuates the effects of miR-17. At the same time, transfection with a kinase-inactive mutant of protein kinase C δ (PKCδ) (an activator of STAT3) augments M. tuberculosis-induced autophagy, and miR-17 overexpression diminishes phosphorylation of PKCδ, suggesting that an miR-17/PKC δ/STAT3 axis regulates autophagy during M. tuberculosis infection. © 2015 John Wiley & Sons Ltd.

  3. Indoor-Breeding of Aedes albopictus in Northern Peninsular Malaysia and Its Potential Epidemiological Implications

    OpenAIRE

    Dieng, Hamady; Saifur, Rahman G. M.; Hassan, Ahmad Abu; Salmah, M. R. Che; Boots, Michael; Satho, Tomomitsu; Jaal, Zairi; AbuBakar, Sazaly

    2010-01-01

    BACKGROUND: The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity du...

  4. Scotland’s Potential Independence: Defense Implications for Britain, NATO, and the United States

    Science.gov (United States)

    2018-03-01

    EEZ Exclusive Economic Zone EU European Union GDP Gross Domestic Product MoD Ministry of Defence NATO North Atlantic Treaty Organization NPT...Scottish 2 territory in a minimal amount of time. The implications of this effort for NATO could be of concern not only for current regional stability ...Lowlanders focused more on the economic grievances they were facing as businessmen and entrepreneurs whereas the Highlanders found their grievances in

  5. Preservation of autophagy should not direct nutritional therapy

    NARCIS (Netherlands)

    McClave, S.A.; Weijs, P.J.M.

    2015-01-01

    PURPOSE OF REVIEW: Recent reports in the literature have proposed that forced mandatory feeding should be avoided in the first week of critical illness to preserve autophagy, in order to maximize responses to oxidative stress, preserve organ function, and improve outcomes. RECENT FINDINGS: Autophagy

  6. Regulation of Autophagy by Glucose in Mammalian Cells

    Directory of Open Access Journals (Sweden)

    Erwin Knecht

    2012-07-01

    Full Text Available Autophagy is an evolutionarily conserved process that contributes to maintain cell homeostasis. Although it is strongly regulated by many extracellular factors, induction of autophagy is mainly produced by starvation of nutrients. In mammalian cells, the regulation of autophagy by amino acids, and also by the hormone insulin, has been extensively investigated, but knowledge about the effects of other autophagy regulators, including another nutrient, glucose, is more limited. Here we will focus on the signalling pathways by which environmental glucose directly, i.e., independently of insulin and glucagon, regulates autophagy in mammalian cells, but we will also briefly mention some data in yeast. Although glucose deprivation mainly induces autophagy via AMPK activation and the subsequent inhibition of mTORC1, we will also comment other signalling pathways, as well as evidences indicating that, under certain conditions, autophagy can be activated by glucose. A better understanding on how glucose regulates autophagy not only will expand our basic knowledge of this important cell process, but it will be also relevant to understand common human disorders, such as cancer and diabetes, in which glucose levels play an important role.

  7. Autophagy mediates pharmacological lifespan extension by spermidine and resveratrol.

    Science.gov (United States)

    Morselli, Eugenia; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Maiuri, Maria Chiara; Tavernarakis, Nektarios; Madeo, Frank; Kroemer, Guido

    2009-12-23

    Although autophagy has widely been conceived as a self-destructive mechanism that causes cell death, accumulating evidence suggests that autophagy usually mediates cytoprotection, thereby avoiding the apoptotic or necrotic demise of stressed cells. Recent evidence produced by our groups demonstrates that autophagy is also involved in pharmacological manipulations that increase longevity. Exogenous supply of the polyamine spermidine can prolong the lifespan of (while inducing autophagy in) yeast, nematodes and flies. Similarly, resveratrol can trigger autophagy in cells from different organisms, extend lifespan in nematodes, and ameliorate the fitness of human cells undergoing metabolic stress. These beneficial effects are lost when essential autophagy modulators are genetically or pharmacologically inactivated, indicating that autophagy is required for the cytoprotective and/or anti-aging effects of spermidine and resveratrol. Genetic and functional studies indicate that spermidine inhibits histone acetylases, while resveratrol activates the histone deacetylase Sirtuin 1 to confer cytoprotection/longevity. Although it remains elusive whether the same histones (or perhaps other nuclear or cytoplasmic proteins) act as the downstream targets of spermidine and resveratrol, these results point to an essential role of protein hypoacetylation in autophagy control and in the regulation of longevity.

  8. Autophagy contributes to resistance of tumor cells to ionizing radiation.

    Science.gov (United States)

    Chaachouay, Hassan; Ohneseit, Petra; Toulany, Mahmoud; Kehlbach, Rainer; Multhoff, Gabriele; Rodemann, H Peter

    2011-06-01

    Autophagy signaling is a novel important target to improve anticancer therapy. To study the role of autophagy on resistance of tumor cells to ionizing radiation (IR), breast cancer cell lines differing in their intrinsic radiosensitivity were used. Breast cancer cell lines MDA-MB-231 and HBL-100 were examined with respect to clonogenic cell survival and induction of autophagy after radiation exposure and pharmacological interference of the autophagic process. As marker for autophagy the appearance of LC3-I and LC3-II proteins was analyzed by SDS-PAGE and Western blotting. Formation of autophagic vacuoles was monitored by immunofluorescence staining of LC3. LC3-I and LC3-II formation differs markedly in radioresistant MDA-MB-231 versus radiosensitive HBL-100 cells. Western blot analyses of LC3-II/LC3-I ratio indicated marked induction of autophagy by IR in radioresistant MDA-MB-231 cells, but not in radiosensitive HBL-100 cells. Indirect immunofluorescence analysis of LC3-II positive vacuoles confirmed this differential effect. Pre-treatment with 3-methyladenine (3-MA) antagonized IR-induced autophagy. Likewise, pretreatment of radioresistant MDA-231 cells with autophagy inhibitors 3-MA or chloroquine (CQ) significantly reduced clonogenic survival of irradiated cells. Our data clearly indicate that radioresistant breast tumor cells show a strong post-irradiation induction of autophagy, which thus serves as a protective and pro-survival mechanism in radioresistance. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  9. Autophagy in Negative-Strand RNA Virus Infection

    Directory of Open Access Journals (Sweden)

    Yupeng Wang

    2018-02-01

    Full Text Available Autophagy is a homoeostatic process by which cytoplasmic material is targeted for degradation by the cell. Viruses have learned to manipulate the autophagic pathway to ensure their own replication and survival. Although much progress has been achieved in dissecting the interplay between viruses and cellular autophagic machinery, it is not well understood how the cellular autophagic pathway is utilized by viruses and manipulated to their own advantage. In this review, we briefly introduce autophagy, viral xenophagy and the interaction among autophagy, virus and immune response, then focus on the interplay between NS-RNA viruses and autophagy during virus infection. We have selected some exemplary NS-RNA viruses and will describe how these NS-RNA viruses regulate autophagy and the role of autophagy in NS-RNA viral replication and in immune responses to virus infection. We also review recent advances in understanding how NS-RNA viral proteins perturb autophagy and how autophagy-related proteins contribute to NS-RNA virus replication, pathogenesis and antiviral immunity.

  10. Autophagy-dependent secretion: contribution to tumor progression

    Directory of Open Access Journals (Sweden)

    Tom Keulers

    2016-11-01

    Full Text Available Autophagy is best known as a lysosomal degradation and recycling pathway to maintain cellular homeostasis. During autophagy, cytoplasmic content is recognized and packed in autophagic vacuoles, or autophagosomes, and targeted for degradation. However, during the last years, it has become evident that the role of autophagy is not restricted to degradation alone but also mediates unconventional forms of secretion. Furthermore, cells with defects in autophagy apparently are able to reroute their cargo, like mitochondria, to the extracellular environment; effects that contribute to an array of pathologies. In this review we discuss the current knowledge of the physiological roles of autophagy-dependent secretion, i.e. the effect on inflammation and insulin/ hormone secretion. Finally, we focus on the effects of autophagy-dependent secretion on the tumour microenvironment and tumour progression. The autophagy mediated secreted factors may stimulate cellular proliferation via auto- and paracrine signaling. The autophagy mediated release of immune modulating proteins change the immunosuppresive tumor microenvironment and may promote an invasive phenotype. These effects may be either direct or indirect through facilitating formation of the mobilized vesicle, aid in anterograde trafficking or alterations in homeostasis and/or autonomous cell signaling.

  11. Role of Autophagy in the Control of Body Metabolism

    Directory of Open Access Journals (Sweden)

    Wenying Quan

    2013-03-01

    Full Text Available Autophagy plays a crucial role in the maintenance of cellular nutrient balance and the function of organelles such as mitochondria or the endoplasmic reticulum, which are important in intracellular metabolism, insulin release, and insulin sensitivity. In the insulin-producing pancreatic β-cells, autophagy is important in the maintenance of β-cell mass, structure, and function. Mice with deficiencies in β-cell-specific autophagy show reduced β-cell mass and defects in insulin secretion that lead to hypoinsulinemia and hyperglycemia but not diabetes. However, these mice developed diabetes when bred with ob/ob mice, suggesting that autophagy-deficient β-cells have defects in dealing with the increased metabolic stress imposed by obesity. These results also imply that autophagy deficiency in β-cells could be a factor in the progression from obesity to diabetes. Another important function of autophagy is in hypothalamic neurons for the central control of energy expenditure, appetite, and body weight. In addition, mice with autophagy deficiencies in the target tissues of insulin have yielded diverse phenotypes. Taken together, these results suggest that autophagy is important in the control of whole body energy and nutrient homeostasis, and its dysregulation could play a role in the development of metabolic disorders and diabetes.

  12. The Nobel Prize for understanding autophagy, a cellular mechanism ...

    Indian Academy of Sciences (India)

    The lysosome was identified by Christian de Duve in the 1950s as a membrane bound organelle in thecell that contains degradative enzymes such as proteases, lipases, acid phosphatases, etc. (de Duve, 2005).The term autophagy was coined by Christian de Duve in 1963. Autophagy generally occurs at low level, butit ...

  13. Autophagy Primes Neutrophils for Neutrophil Extracellular Trap Formation during Sepsis.

    Science.gov (United States)

    Park, So Young; Shrestha, Sanjeeb; Youn, Young-Jin; Kim, Jun-Kyu; Kim, Shin-Yeong; Kim, Hyun Jung; Park, So-Hee; Ahn, Won-Gyun; Kim, Shin; Lee, Myung Goo; Jung, Ki-Suck; Park, Yong Bum; Mo, Eun-Kyung; Ko, Yousang; Lee, Suh-Young; Koh, Younsuck; Park, Myung Jae; Song, Dong-Keun; Hong, Chang-Won

    2017-09-01

    Neutrophils are key effectors in the host's immune response to sepsis. Excessive stimulation or dysregulated neutrophil functions are believed to be responsible for sepsis pathogenesis. However, the mechanisms regulating functional plasticity of neutrophils during sepsis have not been fully determined. We investigated the role of autophagy in neutrophil functions during sepsis in patients with community-acquired pneumonia. Neutrophils were isolated from patients with sepsis and stimulated with phorbol 12-myristate 13-acetate (PMA). The levels of reactive oxygen species generation, neutrophil extracellular trap (NET) formation, and granule release, and the autophagic status were evaluated. The effect of neutrophil autophagy augmentation was further evaluated in a mouse model of sepsis. Neutrophils isolated from patients who survived sepsis showed an increase in autophagy induction, and were primed for NET formation in response to subsequent PMA stimulation. In contrast, neutrophils isolated from patients who did not survive sepsis showed dysregulated autophagy and a decreased response to PMA stimulation. The induction of autophagy primed healthy neutrophils for NET formation and vice versa. In a mouse model of sepsis, the augmentation of autophagy improved survival via a NET-dependent mechanism. These results indicate that neutrophil autophagy primes neutrophils for increased NET formation, which is important for proper neutrophil effector functions during sepsis. Our study provides important insights into the role of autophagy in neutrophils during sepsis.

  14. Inhibition of autophagy as a treatment strategy for p53 wild-type acute myeloid leukemia

    NARCIS (Netherlands)

    Folkerts, Hendrik; Hilgendorf, Susan; Wierenga, Albertus T J; Jaques, Jennifer; Mulder, André B; Coffer, Paul J; Schuringa, Jan Jacob; Vellenga, Edo

    2017-01-01

    Here we have explored whether inhibition of autophagy can be used as a treatment strategy for acute myeloid leukemia (AML). Steady-state autophagy was measured in leukemic cell lines and primary human CD34(+) AML cells with a large variability in basal autophagy between AMLs observed. The autophagy

  15. TGF-β2 initiates autophagy via Smad and non-Smad pathway to promote glioma cells’ invasion

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2017-11-01

    Full Text Available Abstract Background Glioblastoma multiforme (GBM is characterized by lethal aggressiveness and patients with GBM are in urgent need for new therapeutic avenues to improve quality of life. Current studies on tumor invasion focused on roles of cytokines in tumor microenvironment and numerous evidence suggests that TGF-β2 is abundant in glioma microenvironment and vital for glioma invasion. Autopagy is also emerging as a critical factor in aggressive behaviors of cancer cells; however, the relationship between TGF-β2 and autophagy in glioma has been poorly understood. Methods U251, T98 and U87 GBM cell lines as well as GBM cells from a primary human specimen were used in vitro and in vivo to evaluate the effect of TGF-β2 on autophagy. Western blot, qPCR, immunofluorescence and transmission-electron microscope were used to detect target molecular expression. Lentivirus and siRNA vehicle were introduced to establish cell lines, as well as mitotracker and seahorse experiment to study the metabolic process in glioma. Preclinical therapeutic efficacy was evaluated in orthotopic xenograft mouse models. Results Here we demonstrated that TGF-β2 activated autophagy in human glioma cell lines and knockdown of Smad2 or inhibition of c-Jun NH2-terminal kinase, attenuated TGF-β2-induced autophagy. TGF-β2-induced autophagy is important for glioma invasion due to the alteration of epithelial-mesenchymal transition and metabolism conversion, particularly influencing mitochondria trafficking and membrane potential (△Ψm. Autopaghy also initiated a feedback on TGF-β2 in glioma by keeping its autocrine loop and affecting Smad2/3/7 expression. A xenograft model provided additional confirmation on combination of TGF-β inhibitor (Galunisertib and autophagy inhibitor (CQ to better “turn off” tumor growth. Conclusion Our findings elucidated a potential mechanism of autophagy-associated glioma invasion that TGF-β2 could initiate autophagy via Smad and non

  16. Autophagy in Drosophila: From Historical Studies to Current Knowledge

    Science.gov (United States)

    Mulakkal, Nitha C.; Nagy, Peter; Takats, Szabolcs; Tusco, Radu; Juhász, Gábor; Nezis, Ioannis P.

    2014-01-01

    The discovery of evolutionarily conserved Atg genes required for autophagy in yeast truly revolutionized this research field and made it possible to carry out functional studies on model organisms. Insects including Drosophila are classical and still popular models to study autophagy, starting from the 1960s. This review aims to summarize past achievements and our current knowledge about the role and regulation of autophagy in Drosophila, with an outlook to yeast and mammals. The basic mechanisms of autophagy in fruit fly cells appear to be quite similar to other eukaryotes, and the role that this lysosomal self-degradation process plays in Drosophila models of various diseases already made it possible to recognize certain aspects of human pathologies. Future studies in this complete animal hold great promise for the better understanding of such processes and may also help finding new research avenues for the treatment of disorders with misregulated autophagy. PMID:24949430

  17. Does autophagy work in synaptic plasticity and memory?

    Science.gov (United States)

    Shehata, Mohammad; Inokuchi, Kaoru

    2014-01-01

    Many studies have reported the roles played by regulated proteolysis in neural plasticity and memory. Within this context, most of the research focused on the ubiquitin-proteasome system and the endosome-lysosome system while giving lesser consideration to another major protein degradation system, namely, autophagy. Although autophagy intersects with many of the pathways known to underlie synaptic plasticity and memory, only few reports related autophagy to synaptic remodeling. These pathways include PI3K-mTOR pathway and endosome-dependent proteolysis. In this review, we will discuss several lines of evidence supporting a physiological role of autophagy in memory processes, and the possible mechanistic scenarios for how autophagy could fulfill this function.

  18. Autophagy in Drosophila: From Historical Studies to Current Knowledge

    Directory of Open Access Journals (Sweden)

    Nitha C. Mulakkal

    2014-01-01

    Full Text Available The discovery of evolutionarily conserved Atg genes required for autophagy in yeast truly revolutionized this research field and made it possible to carry out functional studies on model organisms. Insects including Drosophila are classical and still popular models to study autophagy, starting from the 1960s. This review aims to summarize past achievements and our current knowledge about the role and regulation of autophagy in Drosophila, with an outlook to yeast and mammals. The basic mechanisms of autophagy in fruit fly cells appear to be quite similar to other eukaryotes, and the role that this lysosomal self-degradation process plays in Drosophila models of various diseases already made it possible to recognize certain aspects of human pathologies. Future studies in this complete animal hold great promise for the better understanding of such processes and may also help finding new research avenues for the treatment of disorders with misregulated autophagy.

  19. Modulation of Autophagy-Like Processes by Tumor Viruses

    Directory of Open Access Journals (Sweden)

    Karl Munger

    2012-06-01

    Full Text Available Autophagy is an intracellular degradation pathway for long-lived proteins and organelles. This process is activated above basal levels upon cell intrinsic or environmental stress and dysregulation of autophagy has been linked to various human diseases, including those caused by viral infection. Many viruses have evolved strategies to directly interfere with autophagy, presumably to facilitate their replication or to escape immune detection. However, in some cases, modulation of autophagy appears to be a consequence of the virus disturbing the cell’s metabolic signaling networks. Here, we summarize recent advances in research at the interface of autophagy and viral infection, paying special attention to strategies that human tumor viruses have evolved.

  20. Regulation of autophagy by AMP-activated protein kinase/ sirtuin 1 pathway reduces spinal cord neurons damage

    Directory of Open Access Journals (Sweden)

    Peng Yan

    2017-09-01

    Full Text Available Objective(s: AMP-activated protein kinase/sirtuin 1 (AMPK/SIRT1 signaling pathway has been proved to be involved in the regulation of autophagy in various models. The aim of this study was to evaluate the effect of AMPK/SIRT1 pathway on autophagy after spinal cord injury (SCI. Materials and Methods:The SCI model was established in rats in vivo and the primary spinal cord neurons were subjected to mechanical injury (MI in vitro. The apoptosis in spinal cord tissue and neurons was assessed by TUNEL staining and Hoechst 33342 staining, respectively. The autophagy-related proteins levels were detected by Western blot. The activation of AMPK/SIRT1 pathway was determined by Western blot and immunohistochemical staining. Results: We found that the apoptosis of spinal cord tissue and cell damage of spinal cord neurons was obvious after the trauma. The ratio of LC3II/LC3I and level of p62 were first increased significantly and then decreased after the trauma in vivo and in vitro, indicating the defect in autophagy. The levels of p-AMPK and SIRT1 were increased obviously after the trauma in vivo and in vitro. Further activation of the AMPK/SIRT1 pathway by pretreatment with resveratrol, a confirmed activator of the AMPK/SIRT1 pathway, alleviated the cell damage and promoted the autophagy flux via downregulation of p62 in spinal cord neurons at 24 hr after MI. Conclusion: Our results demonstrate that regulation of autophagy by AMPK/SIRT1 pathway can restrain spinal cord neurons damage, which may be a potential intervention of SCI.

  1. Dihydrocapsaicin (DHC), a saturated structural analog of capsaicin, induces autophagy in human cancer cells in a catalase-regulated manner.

    Science.gov (United States)

    Oh, Seon Hee; Kim, Young Soon; Lim, Sung Chul; Hou, Yi Feng; Chang, In Youb; You, Ho Jin

    2008-11-01

    Although capsaicin, a pungent component of red pepper, is known to induce apoptosis in several types of cancer cells, the mechanisms underlying capsaicin-induced cytotoxicity are unclear. Here, we showed that dihydrocapsaicin (DHC), an analog of capsaicin, is a potential inducer of autophagy. DHC was more cytotoxic than capsaicin in HCT116, MCF-7 and WI38 cell lines. Capsaicin and DHC did not affect the sub-G(1) apoptotic peak, but induced G(0)/G(1) arrest in HCT116 and MCF-7 cells. DHC caused the artificial autophagosome marker GFP-LC3 to redistribute and upregulated expression of autophagy-related proteins. Blocking of autophagy by 3-methyladenine (3MA) as well as siRNA Atg5 induced a high level of caspase-3 activation. Although pretreatment with zVAD completely inhibited caspase-3 activation by 3MA, it did not prevent cell death. DHC-induced autophagy was enhanced by zVAD pretreatment, as shown by increased accumulation of LC3-II protein. DHC attenuated basal ROS levels through catalase induction; this effect was enhanced by antioxidants, which increased both LC3-II expression and caspase-3 activation. The catalase inhibitor 3-amino-1,2,4-triazole (3AT) abrogated DHC-induced expression of LC3-II, overexpression of the catalase gene increased expression of LC3-II protein, and knockdown decreased it. Additionally, DHC-induced autophagy was independent of p53 status. Collectively, DHC activates autophagy in a p53-independent manner and that may contribute to cytotoxicity of DHC.

  2. Autophagy Facilitates Metadherin-Induced Chemotherapy Resistance Through the AMPK/ATG5 Pathway in Gastric Cancer

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    Guoqing Pei

    2018-04-01

    Full Text Available Background/Aims: Metadherin (MTDH is overexpressed in some malignancies and enhances drug resistance; however, its role in gastric cancer (GC and the underlying mechanisms remain largely unexplored. Here, we explore the mechanism by which MTDH induces drug resistance in GC. Methods: We analysed the level of MTDH in GC and adjacent normal gastric mucosal tissues by real-time quantitative PCR (q-PCR. We also analysed the level of autophagy by western blot analysis, confocal microscopy, and transmission electron microscopy after MTDH knockdown and overexpression, and examined fluorouracil (5-FU resistance by Cell Counting Kit-8 at the same time. Finally, GC patient-derived xenograft tumours were used to demonstrate 5-FU resistance. An AMPK pathway inhibitor was applied to determine the molecular mechanisms of autophagy. Results: MTDH expression was significantly increased in the GC specimens compared with that in the adjacent normal gastric mucosal tissues. Further study showed a positive correlation between the expression level of MTDH and 5-FU resistance. MTDH overexpression in MKN45 cells increased the levels of P-glycoprotein (P-gp and promoted 5-FU resistance, while inhibition of MTDH showed the opposite result. The simultaneous inhibition of autophagy and overexpression of MTDH decreased the levels of P-gp and inhibited 5-FU resistance. Moreover, MTDH induced AMPK phosphorylation, regulated ATG5 expression, and finally influenced autophagy, suggesting that MTDH may activate autophagy via the AMPK/ATG5 signalling pathway. Our findings reveal a unique mechanism by which MTDH promotes GC chemoresistance and show that MTDH is a potential target for improved chemotherapeutic sensitivity and GC patient survival. Conclusions: MTDH-stimulated cancer resistance to 5-FU may be mediated through autophagy activated by the AMPK/ATG5 pathway in GC.

  3. Regulation of autophagy by AMP-activated protein kinase/sirtuin 1 pathway reduces spinal cord neurons damage.

    Science.gov (United States)

    Yan, Peng; Bai, Liangjie; Lu, Wei; Gao, Yuzhong; Bi, Yunlong; Lv, Gang

    2017-09-01

    AMP-activated protein kinase/sirtuin 1 (AMPK/SIRT1) signaling pathway has been proved to be involved in the regulation of autophagy in various models. The aim of this study was to evaluate the effect of AMPK/SIRT1 pathway on autophagy after spinal cord injury (SCI). The SCI model was established in rats in vivo and the primary spinal cord neurons were subjected to mechanical injury (MI) in vitro . The apoptosis in spinal cord tissue and neurons was assessed by TUNEL staining and Hoechst 33342 staining, respectively. The autophagy-related proteins levels were detected by Western blot. The activation of AMPK/SIRT1 pathway was determined by Western blot and immunohistochemical staining. We found that the apoptosis of spinal cord tissue and cell damage of spinal cord neurons was obvious after the trauma. The ratio of LC3II/LC3I and level of p62 were first increased significantly and then decreased after the trauma in vivo and in vitro , indicating the defect in autophagy. The levels of p-AMPK and SIRT1 were increased obviously after the trauma in vivo and in vitro . Further activation of the AMPK/SIRT1 pathway by pretreatment with resveratrol, a confirmed activator of the AMPK/SIRT1 pathway, alleviated the cell damage and promoted the autophagy flux via downregulation of p62 in spinal cord neurons at 24 hr after MI. Our results demonstrate that regulation of autophagy by AMPK/SIRT1 pathway can restrain spinal cord neurons damage, which may be a potential intervention of SCI.

  4. The Chemical Potential of Plasma Membrane Cholesterol: Implications for Cell Biology.

    Science.gov (United States)

    Ayuyan, Artem G; Cohen, Fredric S

    2018-02-27

    Cholesterol is abundant in plasma membranes and exhibits a variety of interactions throughout the membrane. Chemical potential accounts for thermodynamic consequences of molecular interactions, and quantifies the effective concentration (i.e., activity) of any substance participating in a process. We have developed, to our knowledge, the first method to measure cholesterol chemical potential in plasma membranes. This was accomplished by complexing methyl-β-cyclodextrin with cholesterol in an aqueous solution and equilibrating it with an organic solvent containing dissolved cholesterol. The chemical potential of cholesterol was thereby equalized in the two phases. Because cholesterol is dilute in the organic phase, here activity and concentration were equivalent. This equivalence allowed the amount of cholesterol bound to methyl-β-cyclodextrin to be converted to cholesterol chemical potential. Our method was used to determine the chemical potential of cholesterol in erythrocytes and in plasma membranes of nucleated cells in culture. For erythrocytes, the chemical potential did not vary when the concentration was below a critical value. Above this value, the chemical potential progressively increased with concentration. We used standard cancer lines to characterize cholesterol chemical potential in plasma membranes of nucleated cells. This chemical potential was significantly greater for highly metastatic breast cancer cells than for nonmetastatic breast cancer cells. Chemical potential depended on density of the cancer cells. A method to alter and fix the cholesterol chemical potential to any value (i.e., a cholesterol chemical potential clamp) was also developed. Cholesterol content did not change when cells were clamped for 24-48 h. It was found that the level of activation of the transcription factor STAT3 increased with increasing cholesterol chemical potential. The cholesterol chemical potential may regulate signaling pathways. Copyright © 2018. Published by

  5. Autophagy-related genes in Helicobacter pylori infection.

    Science.gov (United States)

    Tanaka, Shingo; Nagashima, Hiroyuki; Uotani, Takahiro; Graham, David Y; Yamaoka, Yoshio

    2017-06-01

    In vitro studies have shown that Helicobacter pylori (H. pylori) infection induces autophagy in gastric epithelial cells. However, prolonged exposure to H. pylori reduces autophagy by preventing maturation of the autolysosome. The alterations of the autophagy-related genes in H. pylori infection are not yet fully understood. We analyzed autophagy-related gene expression in H. pylori-infected gastric mucosa compared with uninfected gastric mucosa obtained from 136 Bhutanese volunteers with mild dyspeptic symptoms. We also studied single nucleotide polymorphisms (SNPs) of autophagy-related gene in 283 Bhutanese participants to identify the influence on susceptibility to H. pylori infection. Microarray analysis of 226 autophagy-related genes showed that 16 genes were upregulated (7%) and nine were downregulated (4%). We used quantitative reverse transcriptase polymerase chain reaction to measure mRNA levels of the downregulated genes (ATG16L1, ATG5, ATG4D, and ATG9A) that were core molecules of autophagy. ATG16L1 and ATG5 mRNA levels in H. pylori-positive specimens (n=86) were significantly less than those in H. pylori-negative specimens (n=50). ATG16L1 mRNA levels were inversely related to H. pylori density. We also compared SNPs of ATG16L1 (rs2241880) among 206 H. pylori-positive and 77 H. pylori-negative subjects. The odds ratio for the presence of H. pylori in the GG genotype was 0.40 (95% CI: 0.18-0.91) relative to the AA/AG genotypes. Autophagy-related gene expression profiling using high-throughput microarray analysis indicated that downregulation of core autophagy machinery genes may depress autophagy functions and possibly provide a better intracellular habit for H. pylori in gastric epithelial cells. © 2017 John Wiley & Sons Ltd.

  6. Pravastatin Protects Against Avascular Necrosis of Femoral Head via Autophagy.

    Science.gov (United States)

    Liao, Yun; Zhang, Ping; Yuan, Bo; Li, Ling; Bao, Shisan

    2018-01-01

    Autophagy serves as a stress response and may contribute to the pathogenesis of avascular necrosis of the femoral head induced by steroids. Statins promote angiogenesis and ameliorate endothelial functions through apoptosis inhibition and necrosis of endothelial progenitor cells, however the process used by statins to modulate autophagy in avascular necrosis of the femoral head remains unclear. This manuscript determines whether pravastatin protects against dexamethasone-induced avascular necrosis of the femoral head by activating endothelial progenitor cell autophagy. Pravastatin was observed to enhance the autophagy activity in endothelial progenitor cells, specifically by upregulating LC3-II/Beclin-1 (autophagy related proteins), and autophagosome formation in vivo and in vitro . An autophagy inhibitor, 3-MA, reduced pravastatin protection in endothelial progenitor cells exposed to dexamethasone by attenuating pravastatin-induced autophagy. Adenosine monophosphate-activated protein kinase (AMPK) is a key autophagy regulator by sensing cellular energy changes, and indirectly suppressing activation of the mammalian target of rapamycin (mTOR). We found that phosphorylation of AMPK was upregulated however phosphorylation of mTOR was downregulated in pravastatin-treated endothelial progenitor cells, which was attenuated by AMPK inhibitor compound C. Furthermore, liver kinase B1 (a phosphorylase of AMPK) knockdown eliminated pravastatin regulated autophagy protein LC3-II in endothelial progenitor cells in vitro . We therefore demonstrated pravastatin rescued endothelial progenitor cells from dexamethasone-induced autophagy dysfunction through the AMPK-mTOR signaling pathway in a liver kinase B1-dependent manner. Our results provide useful information for the development of novel therapeutics for management of glucocorticoids-induced avascular necrosis of the femoral head.

  7. Non-specific effects of vaccines: plausible and potentially important, but implications uncertain.

    Science.gov (United States)

    Pollard, Andrew J; Finn, Adam; Curtis, Nigel

    2017-11-01

    Non-specific effects (NSE) or heterologous effects of vaccines are proposed to explain observations in some studies that certain vaccines have an impact beyond the direct protection against infection with the specific pathogen for which the vaccines were designed. The importance and implications of such effects remain controversial. There are several known immunological mechanisms which could lead to NSE, since it is widely recognised that the generation of specific immunity is initiated by non-specific innate immune mechanisms that may also have wider effects on adaptive immune function. However, there are no published studies that demonstrate a mechanistic link between such immunological phenomena and clinically relevant NSE in humans. While it is highly plausible that some vaccines do have NSE, their magnitude and duration, and thus importance, remain uncertain. Although the WHO recently concluded that current evidence does not justify changes to immunisation policy, further studies of sufficient size and quality are needed to assess the importance of NSE for all-cause mortality. This could provide insights into vaccine immunobiology with important implications for infant health and survival. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Inhibition of autophagy contributes to the toxicity of cadmium telluride quantum dots in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Fan J

    2016-07-01

    Full Text Available Junpeng Fan,1–4 Ming Shao,1–4 Lu Lai,3–5 Yi Liu,3–5 Zhixiong Xie1–4,6 1College of Life Sciences, Wuhan University, 2Hubei Provincial Cooperative Innovation Center of Industrial Fermentation,3State Key Laboratory of Virology, 4Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE, 5College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 6School of Life Science and Technology, Hubei Engineering University, Xiaogan, People’s Republic of China Abstract: Cadmium telluride quantum dots (CdTe QDs are used as near-infrared probes in biologic and medical applications, but their cytological effects and mechanism of potential toxicity are still unclear. In this study, we evaluated the toxicity of CdTe QDs of different sizes and investigated their mechanism of toxicity in the yeast Saccharomyces cerevisiae. A growth inhibition assay revealed that orange-emitting CdTe (O-CdTe QDs (half inhibitory concentration [IC50] =59.44±12.02 nmol/L were more toxic than green-emitting CdTe QDs (IC50 =186.61±19.74 nmol/L to S. cerevisiae. Further studies on toxicity mechanisms using a transmission electron microscope and green fluorescent protein tagged Atg8 processing assay revealed that O-CdTe QDs could partially inhibit autophagy at a late stage, which differs from the results reported in mammalian cells. Moreover, autophagy inhibited at a late stage by O-CdTe QDs could be partially recovered by enhancing autophagy with rapamycin (an autophagy activator, combined with an increased number of living cells. These results indicate that inhibition of autophagy acts as a toxicity mechanism of CdTe QDs in S. cerevisiae. This work reports a novel toxicity mechanism of CdTe QDs in yeast and provides valuable information on the effect of CdTe QDs on the processes of living cells. Keywords: CdTe quantum dots, Saccharomyces cerevisiae, toxicity, autophagy

  9. Fish oil curtails the human action potential dome in a heterogeneous manner: Implication for arrhythmogenesis

    NARCIS (Netherlands)

    Verkerk, Arie O.; den Ruijter, Hester M.; de Jonge, Nicolaas; Coronel, Ruben

    2009-01-01

    Omega-3 polyunsaturated fatty acids (omega3-PUFAs) from fish oil modulate various ion channels, including the L-type calcium current (I(Ca,L)). As a result, fish oil shortens the cardiac action potential and may cause a loss of the dome of the action potential (AP). Under conditions of increased

  10. Extensive Lysine Methylation in Hyperthermophilic Crenarchaea: Potential Implications for Protein Stability and Recombinant Enzymes

    Directory of Open Access Journals (Sweden)

    Catherine H. Botting

    2010-01-01

    Full Text Available In eukarya and bacteria, lysine methylation is relatively rare and is catalysed by sequence-specific lysine methyltransferases that typically have only a single-protein target. Using RNA polymerase purified from the thermophilic crenarchaeum Sulfolobus solfataricus, we identified 21 methyllysines distributed across 9 subunits of the enzyme. The modified lysines were predominantly in α-helices and showed no conserved sequence context. A limited survey of the Thermoproteus tenax proteome revealed widespread modification with 52 methyllysines in 30 different proteins. These observations suggest the presence of an unusual lysine methyltransferase with relaxed specificity in the crenarchaea. Since lysine methylation is known to enhance protein thermostability, this may be an adaptation to a thermophilic lifestyle. The implications of this modification for studies and applications of recombinant crenarchaeal enzymes are discussed.

  11. RNA sequencing atopic dermatitis transcriptome profiling provides insights into novel disease mechanisms with potential therapeutic implications

    DEFF Research Database (Denmark)

    Suárez-Fariñas, Mayte; Ungar, Benjamin; Correa da Rosa, Joel

    2015-01-01

    . These limitations might be lessened with next-generation RNA sequencing (RNA-seq). Objective: We sought to define the lesional AD transcriptome using RNA-seq and compare it using microarrays performed on the same cohort. Methods: RNA-seq and microarrays were performed to identify differentially expressed genes...... RNA-seq showed somewhat better agreement with RT-PCR (intraclass correlation coefficient, 0.57 and 0.70 for microarrays and RNA-seq vs RT-PCR, respectively), bias was not eliminated. Among genes uniquely identified by using RNA-seq were triggering receptor expressed on myeloid cells 1 (TREM-1......) signaling (eg, CCL2, CCL3, and single immunoglobulin domain IL1R1 related [SIGIRR]) and IL-36 isoform genes. TREM-1 is a surface receptor implicated in innate and adaptive immunity that amplifies infection-related inflammation. Conclusions: This is the first report of a lesional AD phenotype using RNA...

  12. Environmental Life Cycle Assessment and Cost Analysis of Bath, NY Wastewater Treatment Plant: Potential Upgrade Implications

    Science.gov (United States)

    Many communities across the U.S. are required to upgrade wastewater treatment plants (WWTP) to meet increasingly stringent nutrient effluent standards. However, increased capital, energy and chemical requirements of upgrades create potential trade-offs between eutrophication pot...

  13. Canonical autophagy does not contribute to cellular radioresistance

    International Nuclear Information System (INIS)

    Schaaf, Marco B.E.; Jutten, Barry; Keulers, Tom G.; Savelkouls, Kim G.M.; Peeters, Hanneke J.M.; Beucken, Twan van den; Schooten, Frederik-Jan van; Godschalk, Roger W.; Vooijs, Marc; Rouschop, Kasper M.A.

    2015-01-01

    Background: (Pre)clinical studies indicate that autophagy inhibition increases response to anti-cancer therapies. Although promising, due to contradicting reports, it remains unclear if radiation therapy changes autophagy activity and if autophagy inhibition changes the cellular intrinsic radiosensitivity. Discrepancies may result from different assays and models through off-target effects and influencing other signaling routes. In this study, we directly compared the effects of genetic and pharmacological inhibition of autophagy after irradiation in human cancer cell lines. Materials and methods: Changes in autophagy activity after ionizing radiation (IR) were assessed by flux analysis in eight cell lines. Clonogenic survival, DNA damage (COMET-assay) and H2AX phosphorylation were assessed after chloroquine or 3-methyladenine pretreatment and after ATG7 or LC3b knockdown. Results: IR failed to induce autophagy and chloroquine failed to change intrinsic radiosensitivity of cells. Interestingly, 3-methyladenine and ATG7- or LC3b-deficiency sensitized cancer cells to irradiation. Surprisingly, the radiosensitizing effect of 3-methyladenine was also observed in ATG7 and LC3b deficient cells and was associated with attenuated γ-H2AX formation and DNA damage repair. Conclusion: Our data demonstrate that the anti-tumor effects of chloroquine are independent of changes in intrinsic radioresistance. Furthermore, ATG7 and LC3b support radioresistance independent of canonical autophagy that involves lysosomal degradation

  14. Distinct Contributions of Autophagy Receptors in Measles Virus Replication.

    Science.gov (United States)

    Petkova, Denitsa S; Verlhac, Pauline; Rozières, Aurore; Baguet, Joël; Claviere, Mathieu; Kretz-Remy, Carole; Mahieux, Renaud; Viret, Christophe; Faure, Mathias

    2017-05-22

    Autophagy is a potent cell autonomous defense mechanism that engages the lysosomal pathway to fight intracellular pathogens. Several autophagy receptors can recognize invading pathogens in order to target them towards autophagy for their degradation after the fusion of pathogen-containing autophagosomes with lysosomes. However, numerous intracellular pathogens can avoid or exploit autophagy, among which is measles virus (MeV). This virus induces a complete autophagy flux, which is required to improve viral replication. We therefore asked how measles virus interferes with autophagy receptors during the course of infection. We report that in addition to NDP52/CALCOCO₂ and OPTINEURIN/OPTN, another autophagy receptor, namely T6BP/TAXIBP1, also regulates the maturation of autophagosomes by promoting their fusion with lysosomes, independently of any infection. Surprisingly, only two of these receptors, NDP52 and T6BP, impacted measles virus replication, although independently, and possibly through physical interaction with MeV proteins. Thus, our results suggest that a restricted set of autophagosomes is selectively exploited by measles virus to replicate in the course of infection.

  15. The inositol trisphosphate receptor in the control of autophagy.

    Science.gov (United States)

    Criollo, Alfredo; Vicencio, José Miguel; Tasdemir, Ezgi; Maiuri, M Chiara; Lavandero, Sergio; Kroemer, Guido

    2007-01-01

    The second messenger myo-inositol-1,4,5-trisphosphate (IP(3)) acts on the IP(3) receptor (IP(3)R), an IP(3)-activated Ca(2+) channel of the endoplasmic reticulum (ER). The IP(3)R agonist IP(3) inhibits starvation-induced autophagy. The IP(3)R antagonist xestospongin B induces autophagy in human cells through a pathway that requires the obligate contribution of Beclin-1, Atg5, Atg10, Atg12 and hVps34, yet is inhibited by ER-targeted Bcl-2 or Bcl-XL, two proteins that physically interact with IP(3)R. Autophagy can also be induced by depletion of the IP(3)R by small interfering RNAs. Autophagy induction by IP(3)R blockade cannot be explained by changes in steady state levels of Ca(2+) in the endoplasmic reticulum (ER) and the cytosol. Autophagy induction by IP(3)R blockade is effective in cells lacking the obligate mediator of ER stress IRE1. In contrast, IRE1 is required for autophagy induced by ER stress-inducing agents such a tunicamycin or thapsigargin. These findings suggest that there are several distinct pathways through which autophagy can be initiated at the level of the ER.

  16. The IKK complex contributes to the induction of autophagy.

    Science.gov (United States)

    Criollo, Alfredo; Senovilla, Laura; Authier, Hélène; Maiuri, Maria Chiara; Morselli, Eugenia; Vitale, Ilio; Kepp, Oliver; Tasdemir, Ezgi; Galluzzi, Lorenzo; Shen, Shensi; Tailler, Maximilien; Delahaye, Nicolas; Tesniere, Antoine; De Stefano, Daniela; Younes, Aména Ben; Harper, Francis; Pierron, Gérard; Lavandero, Sergio; Zitvogel, Laurence; Israel, Alain; Baud, Véronique; Kroemer, Guido

    2010-02-03

    In response to stress, cells start transcriptional and transcription-independent programs that can lead to adaptation or death. Here, we show that multiple inducers of autophagy, including nutrient depletion, trigger the activation of the IKK (IkappaB kinase) complex that is best known for its essential role in the activation of the transcription factor NF-kappaB by stress. Constitutively active IKK subunits stimulated autophagy and transduced multiple signals that operate in starvation-induced autophagy, including the phosphorylation of AMPK and JNK1. Genetic inhibition of the nuclear translocation of NF-kappaB or ablation of the p65/RelA NF-kappaB subunit failed to suppress IKK-induced autophagy, indicating that IKK can promote the autophagic pathway in an NF-kappaB-independent manner. In murine and human cells, knockout and/or knockdown of IKK subunits (but not that of p65) prevented the induction of autophagy in response to multiple stimuli. Moreover, the knockout of IKK-beta suppressed the activation of autophagy by food deprivation or rapamycin injections in vivo, in mice. Altogether, these results indicate that IKK has a cardinal role in the stimulation of autophagy by physiological and pharmacological stimuli.

  17. Laser stimulation can activate autophagy in HeLa cells

    International Nuclear Information System (INIS)

    Wang, Yisen; Hu, Minglie; Wang, Chingyue; Lan, Bei; Cao, Youjia; He, Hao

    2014-01-01

    For decades, lasers have been a daily tool in most biological research for fluorescent excitation by confocal or multiphoton microscopy. More than 20 years ago, cell photodamage caused by intense laser stimulation was noticed by generating reactive oxygen species, which was then thought as the main damage effect by photons. In this study, we show that laser stimulation can induce autophagy, an important cell lysosomal pathway responding to immune stimulation and starvation, without any biochemical treatment. Two different types of laser stimulations are found to be capable of activating autophagy: continuous scanning by continuous-wave visible lasers and a short-time flash of femtosecond laser irradiation. The autophagy generation is independent from wavelength, power, and scanning duration of the visible lasers. In contrast, the power of femtosecond laser is very critical to autophagy because the multiphoton excited Ca 2+ dominates autophagy signaling. In general, we show here the different mechanisms of autophagy generation by such laser stimulation, which correspond to confocal microscopy and cell surgery, respectively. Those results can help further understanding of photodamage and autophagy signaling.

  18. Autophagy as an Emerging Common Pathomechanism in Inherited Peripheral Neuropathies

    Directory of Open Access Journals (Sweden)

    Mansour Haidar

    2017-05-01

    Full Text Available The inherited peripheral neuropathies (IPNs comprise a growing list of genetically heterogeneous diseases. With mutations in more than 80 genes being reported to cause IPNs, a wide spectrum of functional consequences is expected to follow this genotypic diversity. Hence, the search for a common pathomechanism among the different phenotypes has become the holy grail of functional research into IPNs. During the last decade, studies on several affected genes have shown a direct and/or indirect correlation with autophagy. Autophagy, a cellular homeostatic process, is required for the removal of cell aggregates, long-lived proteins and dead organelles from the cell in double-membraned vesicles destined for the lysosomes. As an evolutionarily highly conserved process, autophagy is essential for the survival and proper functioning of the cell. Recently, neuronal cells have been shown to be particularly vulnerable to disruption of the autophagic pathway. Furthermore, autophagy has been shown to be affected in various common neurodegenerative diseases of both the central and the peripheral nervous system including Alzheimer’s, Parkinson’s, and Huntington’s diseases. In this review we provide an overview of the genes involved in hereditary neuropathies which are linked to autophagy and we propose the disruption of the autophagic flux as an emerging common pathomechanism. We also shed light on the different steps of the autophagy pathway linked to these genes. Finally, we review the concept of autophagy being a therapeutic target in IPNs, and the possibilities and challenges of this pathway-specific targeting.

  19. Autophagy in the immune response to tuberculosis: clinical perspectives.

    LENUS (Irish Health Repository)

    Ní Cheallaigh, C

    2011-06-01

    A growing body of evidence points to autophagy as an essential component in the immune response to tuberculosis. Autophagy is a direct mechanism of killing intracellular Mycobacterium tuberculosis and also acts as a modulator of proinflammatory cytokine secretion. In addition, autophagy plays a key role in antigen processing and presentation. Autophagy is modulated by cytokines; it is stimulated by T helper type 1 (Th1) cytokines such as tumour necrosis factor (TNF)-α and interferon (IFN)-γ, and is inhibited by the Th2 cytokines interleukin (IL)-4 and IL-13 and the anti-inflammatory cytokine IL-10. Vitamin D, via cathelicidin, can also induce autophagy, as can Toll-like receptor (TLR)-mediated signals. Autophagy-promoting agents, administered either locally to the lungs or systemically, could have a clinical application as adjunctive treatment of drug-resistant and drug-sensitive tuberculosis. Moreover, vaccines which effectively induce autophagy could be more successful in preventing acquisition or reactivation of latent tuberculosis.

  20. Laser stimulation can activate autophagy in HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yisen; Hu, Minglie; Wang, Chingyue [Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin (China); Lan, Bei; Cao, Youjia [Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, Tianjin (China); He, Hao, E-mail: haohe@tju.edu.cn [Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin (China); Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai (China)

    2014-10-27

    For decades, lasers have been a daily tool in most biological research for fluorescent excitation by confocal or multiphoton microscopy. More than 20 years ago, cell photodamage caused by intense laser stimulation was noticed by generating reactive oxygen species, which was then thought as the main damage effect by photons. In this study, we show that laser stimulation can induce autophagy, an important cell lysosomal pathway responding to immune stimulation and starvation, without any biochemical treatment. Two different types of laser stimulations are found to be capable of activating autophagy: continuous scanning by continuous-wave visible lasers and a short-time flash of femtosecond laser irradiation. The autophagy generation is independent from wavelength, power, and scanning duration of the visible lasers. In contrast, the power of femtosecond laser is very critical to autophagy because the multiphoton excited Ca{sup 2+} dominates autophagy signaling. In general, we show here the different mechanisms of autophagy generation by such laser stimulation, which correspond to confocal microscopy and cell surgery, respectively. Those results can help further understanding of photodamage and autophagy signaling.

  1. The regulation of autophagy differentially affects Trypanosoma cruzi metacyclogenesis.

    Directory of Open Access Journals (Sweden)

    María Cristina Vanrell

    2017-11-01

    Full Text Available Autophagy is a cellular process required for the removal of aged organelles and cytosolic components through lysosomal degradation. All types of eukaryotic cells from yeasts to mammalian cells have the machinery to activate autophagy as a result of many physiological and pathological situations. The most frequent stimulus of autophagy is starvation and the result, in this case, is the fast generation of utilizable food (e.g. amino acids and basic nutrients to maintain the vital biological processes. In some organisms, starvation also triggers other associated processes such as differentiation. The protozoan parasite Trypanosoma cruzi undergoes a series of differentiation processes throughout its complex life cycle. Although not all autophagic genes have been identified in the T. cruzi genome, previous works have demonstrated the presence of essential autophagic-related proteins. Under starvation conditions, TcAtg8, which is the parasite homolog of Atg8/LC3 in other organisms, is located in autophagosome-like vesicles. In this work, we have characterized the autophagic pathway during T. cruzi differentiation from the epimastigote to metacyclic trypomastigote form, a process called metacyclogenesis. We demonstrated that autophagy is stimulated during metacyclogenesis and that the induction of autophagy promotes this process. Moreover, with exception of bafilomycin, other classical autophagy modulators have similar effects on T. cruzi autophagy. We also showed that spermidine and related polyamines can positively regulate parasite autophagy and differentiation. We concluded that both polyamine metabolism and autophagy are key processes during T. cruzi metacyclogenesis that could be exploited as drug targets to avoid the parasite cycle progression.

  2. Autophagy Is an Innate Mechanism Associated with Leprosy Polarization

    Science.gov (United States)

    Andrade, Priscila Ribeiro; Ferreira, Helen; Nery, José Augusto da Costa; Côrte-Real, Suzana; da Silva, Gilberto Marcelo Sperandio; Rosa, Patricia Sammarco; Fabri, Mario; Sarno, Euzenir Nunes

    2017-01-01

    Leprosy is a chronic infectious disease that may present different clinical forms according to the immune response of the host. Levels of IFN-γ are significantly raised in paucibacillary tuberculoid (T-lep) when compared with multibacillary lepromatous (L-lep) patients. IFN-γ primes macrophages for inflammatory activation and induces the autophagy antimicrobial mechanism. The involvement of autophagy in the immune response against Mycobacterium leprae remains unexplored. Here, we demonstrated by different autophagic assays that LC3-positive autophagosomes were predominantly observed in T-lep when compared with L-lep lesions and skin-derived macrophages. Accumulation of the autophagic receptors SQSTM1/p62 and NBR1, expression of lysosomal antimicrobial peptides and colocalization analysis of autolysosomes revealed an impairment of the autophagic flux in L-lep cells, which was restored by IFN-γ or rapamycin treatment. Autophagy PCR array gene-expression analysis revealed a significantly upregulation of autophagy genes (BECN1, GPSM3, ATG14, APOL1, and TPR) in T-lep cells. Furthermore, an upregulation of autophagy genes (TPR, GFI1B and GNAI3) as well as LC3 levels was observed in cells of L-lep patients that developed type 1 reaction (T1R) episodes, an acute inflammatory condition associated with increased IFN-γ levels. Finally, we observed increased BCL2 expression in L-lep cells that could be responsible for the blockage of BECN1-mediated autophagy. In addition, in vitro studies demonstrated that dead, but not live M. leprae can induce autophagy in primary and lineage human monocytes, and that live mycobacteria can reduce the autophagy activation triggered by dead mycobacteria, suggesting that M. leprae may hamper the autophagic machinery as an immune escape mechanism. Together, these results indicate that autophagy is an important innate mechanism associated with the M. leprae control in skin macrophages. PMID:28056107

  3. Oxidative Stress, Redox Signaling, and Autophagy: Cell Death Versus Survival

    Science.gov (United States)

    Navarro-Yepes, Juliana; Burns, Michaela; Anandhan, Annadurai; Khalimonchuk, Oleh; del Razo, Luz Maria; Quintanilla-Vega, Betzabet; Pappa, Aglaia; Panayiotidis, Mihalis I.

    2014-01-01

    Abstract Significance: The molecular machinery regulating autophagy has started becoming elucidated, and a number of studies have undertaken the task to determine the role of autophagy in cell fate determination within the context of human disease progression. Oxidative stress and redox signaling are also largely involved in the etiology of human diseases, where both survival and cell death signaling cascades have been reported to be modulated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Recent Advances: To date, there is a good understanding of the signaling events regulating autophagy, as well as the signaling processes by which alterations in redox homeostasis are transduced to the activation/regulation of signaling cascades. However, very little is known about the molecular events linking them to the regulation of autophagy. This lack of information has hampered the understanding of the role of oxidative stress and autophagy in human disease progression. Critical Issues: In this review, we will focus on (i) the molecular mechanism by which ROS/RNS generation, redox signaling, and/or oxidative stress/damage alter autophagic flux rates; (ii) the role of autophagy as a cell death process or survival mechanism in response to oxidative stress; and (iii) alternative mechanisms by which autophagy-related signaling regulate mitochondrial function and antioxidant response. Future Directions: Our research efforts should now focus on understanding the molecular basis of events by which autophagy is fine tuned by oxidation/reduction events. This knowledge will enable us to understand the mechanisms by which oxidative stress and autophagy regulate human diseases such as cancer and neurodegenerative disorders. Antioxid. Redox Signal. 21, 66–85. PMID:24483238

  4. An educational path for the magnetic vector potential and its physical implications

    International Nuclear Information System (INIS)

    Barbieri, S; Cavinato, M; Giliberti, M

    2013-01-01

    We present an educational path for the magnetic vector potential A aimed at undergraduate students and pre-service physics teachers. Starting from the generalized Ampère–Laplace law, in the framework of a slowly varying time-dependent field approximation, the magnetic vector potential is written in terms of its empirical references, i.e. the conduction currents. Therefore, once the currents are known, our approach allows for a clear and univocal physical determination of A, overcoming the mathematical indeterminacy due to the gauge transformations. We have no need to fix a gauge, since for slowly varying time-dependent electric and magnetic fields, the ‘natural’ gauge for A is the Coulomb one. We stress the difference between our approach and those usually presented in the literature. Finally, a physical interpretation of the magnetic vector potential is discussed and some examples of the calculation of A are analysed. (paper)

  5. ER stress, autophagy, and RNA viruses

    Directory of Open Access Journals (Sweden)

    Jia-Rong eJheng

    2014-08-01

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

  6. Implications of an assessment of potential organic contamination of ground water at an inactive uranium mill

    International Nuclear Information System (INIS)

    Price, J.B.

    1986-01-01

    Laws and regulations concerning remedial actions at inactive uranium mills explicitly recognize radiological and nonradiological hazards and may implicitly recognize the potential presence of hazardous wastes at these mill sites. Ground-water studies at the sites have placed an increasing emphasis on screening for priority pollutants. The Grand Junction, Colorado, mill site was deemed to have a high potential for the presence of organic compounds in ground water, and was chosen as a prototype for assessing the presence of organic compounds in ground water at inactive sites. Lessons learned from the assessment of organics at the Grand Junction site were used to develop a screening procedure for other inactive mill sites

  7. Reactive oxygen species acts as executor in radiation enhancement and autophagy inducing by AgNPs.

    Science.gov (United States)

    Wu, Hao; Lin, Jun; Liu, Peidang; Huang, Zhihai; Zhao, Peng; Jin, Haizhen; Ma, Jun; Wen, Longping; Gu, Ning

    2016-09-01

    Malignant glioma is one of the most common intracranial tumor with a dismal prognosis. The radiosensitizing effect of silver nanoparticles (AgNPs) on glioma both in vitro and in vivo were demonstrated in the previous studies of our group. However, the underlying mechanism is still unclear. In this present study, the use of antioxidants is employed for the regulating of reactive oxygen species (ROS) in U251 cells treated with various agents, and the results shows that ROS played an essential role in the autophagy inducing and radiosensitization effect of AgNPs. Moreover, the inhibition of protective autophagy with 3-MA is another way to increase ROS, resulting in the increasing of cell death and apoptosis. Taken together, understanding the relationship between the elevated ROS and autophagy and the effect of ROS should be useful to the clinical applications of AgNPs. These findings could potentially be exploited for new therapeutic strategies in glioma radiotherapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Endoplasmic Reticulum Stress and Autophagy in Homocystinuria Patients with Remethylation Defects.

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    Ainhoa Martínez-Pizarro

    Full Text Available Proper function of endoplasmic reticulum (ER and mitochondria is crucial for cellular homeostasis, and dysfunction at either site as well as perturbation of mitochondria-associated ER membranes (MAMs have been linked to neurodegenerative and metabolic diseases. Previously, we have observed an increase in ROS and apoptosis levels in patient-derived fibroblasts with remethylation disorders causing homocystinuria. Here we show increased mRNA and protein levels of Herp, Grp78, IP3R1, pPERK, ATF4, CHOP, asparagine synthase and GADD45 in patient-derived fibroblasts suggesting ER stress and calcium perturbations in homocystinuria. In addition, overexpressed MAM-associated proteins (Grp75, σ-1R and Mfn2 were found in these cells that could result in mitochondrial calcium overload and oxidative stress increase. Our results also show an activation of autophagy process and a substantial degradation of altered mitochondria by mitophagy in patient-derived fibroblasts. Moreover, we have observed that autophagy was partially abolished by antioxidants suggesting that ROS participate in this process that may have a protective role. Our findings argue that alterations in Ca2+ homeostasis and autophagy may contribute to the development of this metabolic disorder and suggest a therapeutic potential in homocystinuria for agents that stabilize calcium homeostasis and/or restore the proper function of ER-mitochondria communications.

  9. Thermoresponsive nanocomposite gel for local drug delivery to suppress the growth of glioma by inducing autophagy.

    Science.gov (United States)

    Ding, Li; Wang, Qi; Shen, Ming; Sun, Ying; Zhang, Xiangyu; Huang, Can; Chen, Jianhua; Li, Rongxin; Duan, Yourong

    2017-07-03

    Although the treatments of malignant glioma include surgery, radiotherapy and chemotherapy by oral drug administration, the prognosis of patients with glioma remains very poor. We developed a polyethylene glycol-dipalmitoylphosphatidyle- thanoiamine (mPEG-DPPE) calcium phosphate nanoparticles (NPs) injectable thermoresponsive hydrogel (nanocomposite gel) that could provide a sustained and local delivery of paclitaxel (PTX) and temozolomide (TMZ). In addition, the proportion of PTX and TMZ for the optimal synergistic antiglioma effect on C6 cells was determined to be 1:100 (w/w) by the Chou and Talalay method. Our results clearly indicated that the autophagy induced by PTX:TMZ NPs plays an important role in regulating tumor cell death, while autophagy inhibition dramatically reverses the antitumor effect of PTX:TMZ NPs, suggesting that antiproliferative autophagy occurs in response to PTX:TMZ NPs treatment. The antitumor efficacy of the PTX:TMZ NP-loaded gel was evaluated in situ using C6 tumor-bearing rats, and the PTX:TMZ NP-loaded gel exhibited superior antitumor performance. The antitumor effects of the nanocomposite gel in vivo were shown to correlate with autophagic cell death in this study. The in vivo results further confirmed the advantages of such a strategy. The present study may provide evidence supporting the development of nanomedicine for potential clinical application.

  10. Shuangshen Ningxin Capsule, a Traditional Chinese Medicinal Preparation, Alleviates Myocardial Ischemia through Autophagy Regulation

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2015-01-01

    Full Text Available Shuangshen Ningxin capsule (SSNX, a modern Chinese formula, has been used to treat cardiovascular diseases in Eastern Asia. Our study focuses on the autophagy regulation of SSNX against coronary artery injuries. Myocardial infarction model was established in Chinese miniswines (CMS by coronary artery balloon injury. SSNX was administered to the CMS for 8 weeks with 4 mg/kg or 16 mg/kg. Myocardial cells were incubated with 20% SSNX medicated serum for 2 hours. Assays were performed to detect the effects of SSNX on (i coronary artery diameter by angiography, (ii hemodynamics by noninvasive hemodynamic monitoring system, (iii plaque burden and plaque volume by intravenous ultrasound (iv coronary artery histology by H&E staining, (v autophagosome by transmission electron microscopy, (vi lactate dehydrogenase (LDH leakage, and (vii Beclin-1 and LC3-I/II expressions by Western blot. The results showed that CMS treated with SSNX exhibited the correction for the disturbed cardiac hemodynamics, increase of coronary artery diameter, reduction of high plaque burden and plaque volume, and decrease of LDH. The inhibitory effect of SSNX on CMS autophagy was demonstrated by the reduction of autophagosome and the downregulation of beclin-1 and LC3-I/II. SSNX may protect coronary artery and increase the stability of plaque through the suppression of myocardial cellular autophagy, which suggests the potentially therapeutic effect of SSNX on ischemic cardiovascular disease.

  11. Thiamine Deficiency and Neurodegeneration: the Interplay Among Oxidative Stress, Endoplasmic Reticulum Stress, and Autophagy.

    Science.gov (United States)

    Liu, Dexiang; Ke, Zunji; Luo, Jia

    2017-09-01

    Thiamine (vitamin B1) is an essential nutrient and indispensable for normal growth and development of the organism due to its multilateral participation in key biochemical and physiological processes. Humans must obtain thiamine from their diet since it is synthesized only in bacteria, fungi, and plants. Thiamine deficiency (TD) can result from inadequate intake, increased requirement, excessive deletion, and chronic alcohol consumption. TD affects multiple organ systems, including the cardiovascular, muscular, gastrointestinal, and central and peripheral nervous systems. In the brain, TD causes a cascade of events including mild impairment of oxidative metabolism, neuroinflammation, and neurodegeneration, which are commonly observed in neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Thiamine metabolites may serve as promising biomarkers for neurodegenerative diseases, and thiamine supplementations exhibit therapeutic potential for patients of some neurodegenerative diseases. Experimental TD has been used to model aging-related neurodegenerative diseases. However, to date, the cellular and molecular mechanisms underlying TD-induced neurodegeneration are not clear. Recent research evidence indicates that TD causes oxidative stress, endoplasmic reticulum (ER) stress, and autophagy in the brain, which are known to contribute to the pathogenesis of various neurodegenerative diseases. In this review, we discuss the role of oxidative stress, ER stress, and autophagy in TD-mediated neurodegeneration. We propose that it is the interplay of oxidative stress, ER stress, and autophagy that contributes to TD-mediated neurodegeneration.

  12. Autophagy in retinal ganglion cells in a rhesus monkey chronic hypertensive glaucoma model.

    Directory of Open Access Journals (Sweden)

    Shuifeng Deng

    Full Text Available Primary open angle glaucoma (POAG is a neurodegenerative disease characterized by physiological intraocular hypertension that causes damage to the retinal ganglion cells (RGCs. In the past, RGC damage in POAG was suggested to have been attributed to RGC apoptosis. However, in the present study, we applied a model closer to human POAG through the use of a chronic hypertensive glaucoma model in rhesus monkeys to investigate whether another mode of progressive cell death, autophagy, was activated in the glaucomatous retinas. First, in the glaucomatous retinas, the levels of LC3B-II, LC3B-II/LC3B-I and Beclin 1 increased as demonstrated by Western blot analyses, whereas early or initial autophagic vacuoles (AVi and late or degraded autophagic vacuoles (AVd accumulated in the ganglion cell layer (GCL and in the inner plexiform layer (IPL as determined by transmission electron microscopy (TEM analysis. Second, lysosome activity and autophagosome-lysosomal fusion increased in the RGCs of the glaucomatous retinas, as demonstrated by Western blotting against lysosome associated membrane protein-1 (LAMP1 and double labeling against LC3B and LAMP1. Third, apoptosis was activated in the glaucomatous eyes with increased levels of caspase-3 and cleaved caspase-3 and an increased number of TUNEL-positive RGCs. Our results suggested that autophagy was activated in RGCs in the chronic hypertensive glaucoma model of rhesus monkeys and that autophagy may have potential as a new target for intervention in glaucoma treatment.

  13. Selective autophagy of non-ubiquitylated targets in plants: looking for cognate receptor/adaptor proteins

    Directory of Open Access Journals (Sweden)

    Vasko eVeljanovski

    2014-06-01

    Full Text Available Cellular homeostasis is essential for the physiology of eukaryotic cells. Eukaryotic cells, including plant cells, utilize two main pathways to adjust the level of cytoplasmic components, namely the proteasomal and the lysosomal/vacuolar pathways. Macroautophagy is a lysosomal/vacuolar pathway which, until recently, was thought to be non-specific and a bulk degradation process. However, selective autophagy which can be activated in the cell under various physiological conditions, involves the specific degradation of defined macromolecules or organelles by a conserved molecular mechanism. For this process to be efficient, the mechanisms underlying the recognition and selection of the cargo to be engulfed by the double-membrane autophagosome are critical, and not yet well understood. Ubiquitin (poly-ubiquitin conjugation to the target appears to be a conserved ligand mechanism in many types of selective autophagy, and defined receptors/adaptors recognizing and regulating the autophagosomal capture of the ubiquitylated target have been characterized. However, non-proteinaceous and non-ubiquitylated cargoes are also selectively degraded by this pathway. This ubiquitin-independent selective autophagic pathway also involves receptor and/or adaptor proteins linking the cargo to the autophagic machinery. Some of these receptor/adaptor proteins including accessory autophagy-related (Atg and non-Atg proteins have been described in yeast and animal cells but not yet in plants. In this review we discuss the ubiquitin-independent cargo selection mechanisms in selective autophagy degradation of organelles and macromolecules and speculate on potential plant receptor/adaptor proteins.

  14. MDMA-induced neurotoxicity of serotonin neurons involves autophagy and rilmenidine is protective against its pathobiology.

    Science.gov (United States)

    Mercer, Linda D; Higgins, Gavin C; Lau, Chew L; Lawrence, Andrew J; Beart, Philip M

    2017-05-01

    Toxicity of 3,4-methylenedioxymethamphetamine (MDMA) towards biogenic amine neurons is well documented and in primate brain predominantly affects serotonin (5-HT) neurons. MDMA induces damage of 5-HT axons and nerve fibres and intracytoplasmic inclusions. Whilst its pathobiology involves mitochondrially-mediated oxidative stress, we hypothesised MDMA possessed the capacity to activate autophagy, a proteostatic mechanism for degradation of cellular debris. We established a culture of ventral pons from embryonic murine brain enriched in 5-HT neurons to explore mechanisms of MDMA neurotoxicity and recruitment of autophagy, and evaluated possible neuroprotective actions of the clinically approved agent rilmenidine. MDMA (100 μM-1 mM) reduced cell viability, like rapamycin (RM) and hydrogen peroxide (H 2 O 2 ), in a concentration- and time-dependent manner. Immunocytochemistry revealed dieback of 5-HT arbour: MDMA-induced injury was slower than for RM and H 2 O 2 , neuritic blebbing occurred at 48 and 72 h and Hoechst labelling revealed nuclear fragmentation with 100 μM MDMA. MDMA effected concentration-dependent inhibition of [ 3 H]5-HT uptake with 500 μM MDMA totally blocking transport. Western immunoblotting for microtubule associated protein light chain 3 (LC3) revealed autophagosome formation after treatment with MDMA. Confocal analyses and immunocytochemistry for 5-HT, Hoechst and LC3 confirmed MDMA induced autophagy with abundant LC3-positive puncta within 5-HT neurons. Rilmenidine (1 μM) protected against MDMA-induced injury and image analysis showed full preservation of 5-HT arbours. MDMA had no effect on GABA neurons, indicating specificity of action at 5-HT neurons. MDMA-induced neurotoxicity involves autophagy induction in 5-HT neurons, and rilmenidine via beneficial actions against toxic intracellular events represents a potential treatment for its pathobiology in sustained usage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Zinc oxide nanoparticles induce apoptosis and autophagy in human ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Bai D

    2017-09-01

    Full Text Available Ding-Ping Bai,1,* Xi-Feng Zhang,2,* Guo-Liang Zhang,3,4 Yi-Fan Huang,1 Sangiliyandi Gurunathan5 1Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal Health, Fujian Agriculture and Forestry University, Fuzhou, China; 2College of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, China; 3Dong-E-E-Jiao Co., Ltd., Shandong, China; 4National Engineering Research Center for Gelatin-based Traditional Chinese Medicine, Shandong, China; 5Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Seoul, Republic of Korea *These authors contributed equally to this work Background: Zinc oxide nanoparticles (ZnO NPs are frequently used in industrial products such as paint, surface coating, and cosmetics, and recently, they have been explored in biologic and biomedical applications. Therefore, this study was undertaken to investigate the effect of ZnO NPs on cytotoxicity, apoptosis, and autophagy in human ovarian cancer cells (SKOV3. Methods: ZnO NPs with a crystalline size of 20 nm were characterized with various analytical techniques, including ultraviolet-visible spectroscopy, X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and atomic force microscopy. The cytotoxicity, apoptosis, and autophagy were examined using a series of cellular assays. Results: Exposure of cells to ZnO NPs resulted in a dose-dependent loss of cell viability, and the characteristic apoptotic features such as rounding and loss of adherence, enhanced reactive oxygen species generation, and loss of mitochondrial membrane potential were observed in the ZnO NP-treated cells. Furthermore, the cells treated with ZnO NPs showed significant double-strand DNA breaks, which are gained evidences from significant number of γ-H2AX and Rad51 expressed cells. ZnO NP-treated cells showed upregulation of p53 and LC3, indicating that ZnO NPs are able to upregulate apoptosis and autophagy

  16. Harvest residue removal and soil compaction impact forest productivity and recovery: Potential implications for bioenergy harvests

    Science.gov (United States)

    Miranda T. Curzon; Anthony W. D' Amato; Brian J. Palik

    2014-01-01

    Understanding the effects of management on forest structure and function is increasingly important in light of projected increases in both natural and anthropogenic disturbance severity and frequency with global environmental change. We examined potential impacts of the procurement of forest-derived bioenergy, a change in land use that has been suggested as a climate...

  17. Energy conservation potential in China’s petroleum refining industry: Evidence and policy implications

    International Nuclear Information System (INIS)

    Lin, Boqiang; Xie, Xuan

    2015-01-01

    Highlights: • A long-term equilibrium relationship of energy demand in China’s petroleum refining industry is established. • The sectoral energy conservation potential is evaluated by using scenarios analysis. • Energy prices, enterprise scale, R and D investment and ownership structure affect electricity intensity. • Future policy for energy conservation in China’s petroleum refining industry is suggested. - Abstract: China is currently the second largest petroleum refining country in the world due to rapid growth in recent years. Because the petroleum refining industry is energy-intensive, the rapid growth in petroleum refining and development caused massive energy consumption. China’s urbanization process will guarantee sustained growth of the industry for a long time. Therefore, it is necessary to study the energy conservation potential of the petroleum industry. This paper estimates the energy conservation potential of the industry by applying a cointegration model to investigate the long-run equilibrium relationship between energy consumption and some factors such as energy price, enterprise scale, R and D investment and ownership structure. The results show that R and D investment has the greatest reduction impact on energy intensity, and the growth of market participants (i.e. the decline of the share of state-owned companies) can improve energy efficiency of this industry. Under the advanced energy-saving scenario, the accumulated energy conservation potential will reach 230.18 million tons of coal equivalent (tce). Finally, we provide some targeted policy recommendations for industrial energy conservation

  18. Selecting for Creativity and Innovation Potential: Implications for Practice in Healthcare Education

    Science.gov (United States)

    Patterson, Fiona; Zibarras, Lara Dawn

    2017-01-01

    The ability to innovate is an important requirement in many organisations. Despite this pressing need, few selection systems in healthcare focus on identifying the potential for creativity and innovation and so this area has been vastly under-researched. As a first step towards understanding how we might select for creativity and innovation, this…

  19. Separation of Electric Fields Into Potential and Inductive Parts, and Implications for Radial Diffusion

    Science.gov (United States)

    Chan, A. A.; Ilie, R.; Elkington, S. R.; Albert, J.; Huie, W.

    2017-12-01

    It has been traditional to separate radiation belt radial-diffusion coefficients into two contributions: an "electrostatic" diffusion coefficient, which is assumed to be due to a potential (non-inductive) electric field, and an "electromagnetic" diffusion coefficient , which is assumed to be due to the combined effect of an inductive electric field and the corresponding time-dependent magnetic field. One difficulty in implementing this separation when using magnetospheric fields obtained from measurements, or from MHD simulations, is that only the total electric field is given; the separation of the electric field into potential and inductive parts is not readily available. In this work we separate the electric field using a numerical method based on the Helmholtz decomposition of the total motional electric field calculated by the BATS-R-US MHD code. The inner boundary for the electric potential is based on the Ridley Ionospheric Model solution and we assume floating boundary conditions in the solar wind. Using different idealized solar wind drivers, including a solar wind density that is oscillating at a single frequency or with a broad spectrum of frequencies, we calculate potential and inductive electric fields, electric and magnetic power spectral densities, and corresponding radial diffusion coefficients. Simulations driven by idealized solar wind conditions show a clear separation of the potential and inductive contributions to the power spectral densities and diffusion coefficients. Simulations with more realistic solar wind drivers are underway to better assess the use of electrostatic and electromagnetic diffusion coefficients in understanding ULF wave-particle interactions in Earth's radiation belts.

  20. A large-scale RNA interference screen identifies genes that regulate autophagy at different stages

    DEFF Research Database (Denmark)

    Guo, Sujuan; Pridham, Kevin J; Virbasius, Ching-Man

    2018-01-01

    Dysregulated autophagy is central to the pathogenesis and therapeutic development of cancer. However, how autophagy is regulated in cancer is not well understood and genes that modulate cancer autophagy are not fully defined. To gain more insights into autophagy regulation in cancer, we performed...... with fluorescence-activated cell sorting, we successfully isolated autophagic K562 cells where we identified 336 short hairpin RNAs. After candidate validation using Cyto-ID fluorescence spectrophotometry, LC3B immunoblotting, and quantitative RT-PCR, 82 genes were identified as autophagy-regulating genes. 20 genes...... have been reported previously and the remaining 62 candidates are novel autophagy mediators. Bioinformatic analyses revealed that most candidate genes were involved in molecular pathways regulating autophagy, rather than directly participating in the autophagy process. Further autophagy flux assays...

  1. Spermidine and resveratrol induce autophagy by distinct pathways converging on the acetylproteome.

    Science.gov (United States)

    Morselli, Eugenia; Mariño, Guillermo; Bennetzen, Martin V; Eisenberg, Tobias; Megalou, Evgenia; Schroeder, Sabrina; Cabrera, Sandra; Bénit, Paule; Rustin, Pierre; Criollo, Alfredo; Kepp, Oliver; Galluzzi, Lorenzo; Shen, Shensi; Malik, Shoaib Ahmad; Maiuri, Maria Chiara; Horio, Yoshiyuki; López-Otín, Carlos; Andersen, Jens S; Tavernarakis, Nektarios; Madeo, Frank; Kroemer, Guido

    2011-02-21

    Autophagy protects organelles, cells, and organisms against several stress conditions. Induction of autophagy by resveratrol requires the nicotinamide adenine dinucleotide-dependent deacetylase sirtuin 1 (SIRT1). In this paper, we show that the acetylase inhibitor spermidine stimulates autophagy independent of SIRT1 in human and yeast cells as well as in nematodes. Although resveratrol and spermidine ignite autophagy through distinct mechanisms, these compounds stimulate convergent pathways that culminate in concordant modifications of the acetylproteome. Both agents favor convergent deacetylation and acetylation reactions in the cytosol and in the nucleus, respectively. Both resveratrol and spermidine were able to induce autophagy in cytoplasts (enucleated cells). Moreover, a cytoplasm-restricted mutant of SIRT1 could stimulate autophagy, suggesting that cytoplasmic deacetylation reactions dictate the autophagic cascade. At doses at which neither resveratrol nor spermidine stimulated autophagy alone, these agents synergistically induced autophagy. Altogether, these data underscore the importance of an autophagy regulatory network of antagonistic deacetylases and acetylases that can be pharmacologically manipulated.

  2. Enhancement of nitrite on heme-induced oxidative reactions: A potential toxicological implication.

    Science.gov (United States)

    Lu, Naihao; Chen, Wei; Zhu, Jingjie; Peng, Yi-Yuan

    2012-02-01

    Evidence to support the role of heme as major inducers of oxidative damage is increasingly present. Nitrite (NO(2)(-)) is one of the major end products of NO metabolism. Although the biological significance of heme/NO(2)(-)-mediated protein tyrosine nitration is a subject of great interest, the important roles of NO(2)(-) on heme-dependent redox reaction have been greatly underestimated. In this study, we investigated the influence of NO(2)(-) on heme -dependent oxidative reactions. It was found that NO(2)(-) had the capacity to act as a reducing agent to remove high oxidation states of heme iron. In the reduction of ferryl heme to ferric heme, NO(2)(-) was oxidized to a nitrating agent NO(2), and subsequently, tyrosine residues in bovine serum albumin (BSA) were nitrated. However, the presence of NO(2)(-) surprisingly exerted pro-oxidant effect on heme-H(2)O(2)-induced formation of BSA carbonyls at lower concentrations and enhanced the loss of HepG2 cell viability dose-dependently, which was probably due to the ability of this inorganic compound to efficiently enhance the peroxidase activity and oxidative degradation of heme. These data provide novel evidence that the dietary intake and experimental use of NO(2)(-) in vivo and in vitro would possess the pro-oxidant activity through interfering in heme-dependent oxidative reactions. Besides the classic role in protein tyrosine nitration, the deleterious effects on heme redox reactions may provide new insights into the toxicological implications of NO(2)(-) with cellular heme proteins. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Plasma cadmium and zinc and their interrelationship in adult Nigerians: potential health implications

    Directory of Open Access Journals (Sweden)

    Ugwuja Emmanuel Ike

    2015-06-01

    Full Text Available Zinc (an essential trace element and cadmium (a ubiquitous environmental pollutant with acclaimed toxicity have been found to occur together in nature, with reported antagonism between the two elements. The present study aimed at determination of plasma levels of zinc (Zn and cadmium (Cd and their interrelationship in adult Nigerians. The series comprised adults (n=443 aged ≥18 yrs (mean ± SD 38.4±13.7 yrs, consisting of 117 males, 184 non-pregnant and 140 pregnant females. Sociodemographic data were collected by questionnaire while anthropometrics were determined using standard methods. Plasma Cd and Zn were determined by using an atomic absorption spectrophotometer. The mean plasma zinc and cadmium were 94.7±18.1 μg/dl and 0.150±0.548 μg/dl, respectively. Age, sex, pregnancy, and parity had no effect on either plasma Zn or Cd. Although educational level had no effect on plasma Zn, it had a significant effect on Cd; subjects possessing either secondary or tertiary education had significantly lower plasma Cd than subjects without formal education. Moreover, there seemed to be an inverse relationship between Cd and Zn, but this was not statistically significant (r=–0.089; p=0.061. Although plasma Zn was not related to BMI (r=0.037; p=0.432, Cd was significantly negatively correlated with BMI (r=–0.124; p=0.009. It may be concluded that adult Nigerians in Ebonyi State have elevated plasma levels of Cd, with apparent impact on the levels of plasma Zn. This has important public health implications considering the essential roles of Zn in the protection of Cd mediated adverse health effects. While food diversification is recommended to improve plasma Zn, efforts should be made to reduce exposure to Cd to mitigate partially its possible adverse effects.

  4. Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases.

    Science.gov (United States)

    Angelot, Fanny; Seillès, Estelle; Biichlé, Sabeha; Berda, Yael; Gaugler, Béatrice; Plumas, Joel; Chaperot, Laurence; Dignat-George, Françoise; Tiberghien, Pierre; Saas, Philippe; Garnache-Ottou, Francine

    2009-11-01

    Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies. Microparticles generated from endothelial cell lines, platelets or activated T cells were incubated with human plasmacytoid dendritic cells sorted from healthy donor blood or with monocyte-derived dendritic cells. Dendritic cell maturation was evaluated by flow cytometry, cytokine secretion as well as naive T-cell activation and polarization. Labeled microparticles were also used to study cellular interactions. Endothelial microparticles induced plasmacytoid dendritic cell maturation. In contrast, conventional dendritic cells were resistant to endothelial microparticle-induced maturation. In addition to upregulation of co-stimulatory molecules, endothelial microparticle-matured plasmacytoid dendritic cells secreted inflammatory cytokines (interleukins 6 and 8, but no interferon-alpha) and also induced allogeneic naive CD4(+) T cells to proliferate and to produce type 1 cytokines such as interferon-gamma and tumor necrosis factor-alpha. Endothelial microparticle endocytosis by plasmacytoid dendritic cells appeared to be required for plasmacytoid dendritic cell maturation. Importantly, the ability of endothelial microparticles to induce plasmacytoid dendritic cells to mature was specific as microparticles derived from activated T cells or platelets (the major source of circulating microparticules in healthy subjects) did not induce such plasmacytoid dendritic cell maturation. Our data show that endothelial microparticles specifically induce plasmacytoid dendritic cell maturation and production of inflammatory cytokines. This novel activation pathway may be implicated in various inflammatory disorders and

  5. Globular Adiponectin Attenuated H2O2-Induced Apoptosis in Rat Chondrocytes by Inducing Autophagy Through the AMPK/ mTOR Pathway.

    Science.gov (United States)

    Hu, Junzheng; Cui, Weiding; Ding, Wenxiao; Gu, Yanqing; Wang, Zhen; Fan, Weimin

    2017-01-01

    Chondrocyte apoptosis is closely related to the development and progression of osteoarthritis. Global adiponectin (gAPN), secreted from adipose tissue, possesses potent anti-inflammatory and antiapoptotic properties in various cell types. This study aimed to investigate the role of autophagy induced by gAPN in the suppression of H2O2-induced apoptosis and the potential mechanism of gAPN-induced autophagy in chondrocytes. H2O2 was used to induce apoptotic injury in rat chondrocytes. CCK-8 assay was performed to determine the viability of cells treated with different concentrations of gAPN with or without H2O2. Cell apoptosis was detected by flow cytometry and TUNEL staining. Mitochondrial membrane potential was examined using JC-1 fluorescence staining assay. The autophagy inhibitors 3-MA and Bafilomycin A1 were used to treat cells and then evaluate the effect of gAPN-induced autophagy. To determine the downstream pathway, chondrocytes were preincubated with the AMPK inhibitor Compound C. Beclin-1, LC3B, P62 and apoptosis-related proteins were identified by Western blot analysis. H2O2 (400 µM)-induced chondrocytes apoptosis and caspase-3 activation were attenuated by gAPN (0.5 µg/mL). gAPN increased Bcl-2 expression and decreased Bax expression. The loss of mitochondrial membrane potential induced by H2O2 was also abolished by gAPN. Furthermore, the antiapoptotic effect of gAPN was related to gAPN-induced autophagy by increased formation of Beclin-1 and LC3B and P62 degradation. In particular, the inhibition of gAPN-induced autophagy by 3-MA prevented the protective effect of gAPN on apoptosis induced by H2O2. Moreover, gAPN increased p-AMPK expression and decreased p-mTOR expression. Compound C partly suppressed the expression of autophagy-related proteins and restored the expression of p-mTOR suppressed by gAPN. Thus, the AMPK/mTOR pathway played an important role in the induction of autophagy and protection of H2O2-induced chondrocytes apoptosis by gAPN. g

  6. Globular Adiponectin Attenuated H2O2-Induced Apoptosis in Rat Chondrocytes by Inducing Autophagy Through the AMPK/ mTOR Pathway

    Directory of Open Access Journals (Sweden)

    Junzheng Hu

    2017-08-01

    Full Text Available Background/Aims: Chondrocyte apoptosis is closely related to the development and progression of osteoarthritis. Global adiponectin (gAPN, secreted from adipose tissue, possesses potent anti-inflammatory and antiapoptotic properties in various cell types. This study aimed to investigate the role of autophagy induced by gAPN in the suppression of H2O2-induced apoptosis and the potential mechanism of gAPN-induced autophagy in chondrocytes. Methods: H2O2 was used to induce apoptotic injury in rat chondrocytes. CCK-8 assay was performed to determine the viability of cells treated with different concentrations of gAPN with or without H2O2. Cell apoptosis was detected by flow cytometry and TUNEL staining. Mitochondrial membrane potential was examined using JC-1 fluorescence staining assay. The autophagy inhibitors 3-MA and Bafilomycin A1 were used to treat cells and then evaluate the effect of gAPN-induced autophagy. To determine the downstream pathway, chondrocytes were preincubated with the AMPK inhibitor Compound C. Beclin-1, LC3B, P62 and apoptosis-related proteins were identified by Western blot analysis. Results: H2O2 (400 µM-induced chondrocytes apoptosis and caspase-3 activation were attenuated by gAPN (0.5 µg/mL. gAPN increased Bcl-2 expression and decreased Bax expression. The loss of mitochondrial membrane potential induced by H2O2 was also abolished by gAPN. Furthermore, the antiapoptotic effect of gAPN was related to gAPN-induced autophagy by increased formation of Beclin-1 and LC3B and P62 degradation. In particular, the inhibition of gAPN-induced autophagy by 3-MA prevented the protective effect of gAPN on apoptosis induced by H2O2. Moreover, gAPN increased p-AMPK expression and decreased p-mTOR expression. Compound C partly suppressed the expression of autophagy-related proteins and restored the expression of p-mTOR suppressed by gAPN. Thus, the AMPK/mTOR pathway played an important role in the induction of autophagy and protection of

  7. Healthcare Access for Iraqi Refugee Children in Texas: Persistent Barriers, Potential Solutions, and Policy Implications.

    Science.gov (United States)

    Vermette, David; Shetgiri, Rashmi; Al Zuheiri, Haidar; Flores, Glenn

    2015-10-01

    To identify access barriers to healthcare and potential interventions to improve access for Iraqi refugee children. Four focus groups were conducted using consecutive sampling of Iraqi refugee parents residing in the US for 8 months to 5 years. Eight key-informant interviews also were conducted with employees of organizations serving Iraqi refugee families, recruited using snowball sampling. Focus groups and interviews were audiotaped, transcribed, and analyzed using margin coding and grounded theory. Iraqi refugees identified provider availability, Medicaid maintenance and renewal, language issues, and inadequate recognition of post-traumatic stress disorder as barriers to care for their children. Interviewees cited loss of case-management services and difficulties in understanding the Medicaid renewal process as barriers. Potential interventions to improve access include community-oriented efforts to educate parents on Medicaid renewal, obtaining services, and accessing specialists. Given the enduring nature of language and Medicaid renewal barriers, policies addressing eligibility alone are insufficient.

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

    Directory of Open Access Journals (Sweden)

    Wen-Jun Yan

    2018-02-01

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

  9. Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

    International Nuclear Information System (INIS)

    Xia, D.Y.; Li, W.; Qian, H.R.; Yao, S.; Liu, J.G.; Qi, X.K.

    2013-01-01

    Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis

  10. Curcumin Suppresses Proliferation and Migration of MDA-MB-231 Breast Cancer Cells through Autophagy-Dependent Akt Degradation

    Science.gov (United States)

    Zhang, Yemin; Zhou, Yu; Li, Mingxin; Wang, Changhua

    2016-01-01

    Previous studies have evidenced that the anticancer potential of curcumin (diferuloylmethane), a main yellow bioactive compound from plant turmeric was mediated by interfering with PI3K/Akt signaling. However, the underlying molecular mechanism is still poorly understood. This study experimentally revealed that curcumin treatment reduced Akt protein expression in a dose- and time-dependent manner in MDA-MB-231 breast cancer cells, along with an activation of autophagy and suppression of ubiquitin-proteasome system (UPS) function. The curcumin-reduced Akt expression, cell proliferation, and migration were prevented by genetic and pharmacological inhibition of autophagy but not by UPS inhibition. Additionally, inactivation of AMPK by its specific inhibitor compound C or by target shRNA-mediated silencing attenuated curcumin-activated autophagy. Thus, these results indicate that curcumin-stimulated AMPK activity induces activation of the autophagy-lysosomal protein degradation pathway leading to Akt degradation and the subsequent suppression of proliferation and migration in breast cancer cell. PMID:26752181

  11. GAIP interacting protein C-terminus regulates autophagy and exosome biogenesis of pancreatic cancer through metabolic pathways.

    Directory of Open Access Journals (Sweden)

    Santanu Bhattacharya

    Full Text Available GAIP interacting protein C terminus (GIPC is known to play an important role in a variety of physiological and disease states. In the present study, we have identified a novel role for GIPC as a master regulator of autophagy and the exocytotic pathways in cancer. We show that depletion of GIPC-induced autophagy in pancreatic cancer cells, as evident from the upregulation of the autophagy marker LC3II. We further report that GIPC regulates cellular trafficking pathways by modulating the secretion, biogenesis, and molecular composition of exosomes. We also identified the involvement of GIPC on metabolic stress pathways regulating autophagy and microvesicular shedding, and observed that GIPC status determines the loading of cellular cargo in the exosome. Furthermore, we have shown the overexpression of the drug resistance gene ABCG2 in exosomes from GIPC-depleted pancreatic cancer cells. We also demonstrated that depletion of GIPC from cancer cells sensitized them to gemcitabine treatment, an avenue that can be explored as a potential therapeutic strategy to overcome drug resistance in cancer.

  12. Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Xia, D.Y. [Department of Neurology, Navy General Hospital of PLA, Beijing (China); Li, W. [General Hospital of Shenyang Military Command, Department of Neurology, Shenyang, China, Department of Neurology, General Hospital of Shenyang Military Command, Shenyang (China); Qian, H.R.; Yao, S.; Liu, J.G.; Qi, X.K. [Department of Neurology, Navy General Hospital of PLA, Beijing (China)

    2013-08-10

    Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.

  13. Silencing of BAG3 promotes the sensitivity of ovarian cancer cells to cisplatin via inhibition of autophagy.

    Science.gov (United States)

    Qiu, Shuang; Sun, Liang; Jin, Ye; An, Qi; Weng, Changjiang; Zheng, Jianhua

    2017-07-01

    Ovarian cancer is the most lethal disease among all gynecological malignancies. Interval cytoreductive surgery and cisplatin‑based chemotherapy are the recommended therapeutic strategies. However, acquired resistance to cisplatin remains a big challenge for the overall survival and prognosis in ovarian cancer. Complicated molecular mechanisms are involved in the process. At present, increasing evidence indicates that autophagy plays an important role in the prosurvival and resistance against chemotherapy. In the present study, as a novel autophagy regulator, BCL2‑associated athanogene 3 (BAG3) was investigated to study its role in cisplatin sensitivity in epithelial ovarian cancer. However, whether BAG3 participates in cisplatin sensitivity by inducing autophagy and the underlying mechanism in ovarian cancer cells remain to be clarified. Through the use of quantitative real-time PCR, western blot analysis, CCK-8 and immunofluorescence assays our data revealed that cisplatin-induced autophagy protected ovarian cancer cells from the toxicity of the drug and that this process was regulated by BAG3. Silencing of BAG3 increased cisplatin-induced apoptosis. The results also revealed BAG3 as a potential therapeutic target which enhanced the efficacy of cisplatin in ovarian cancer.

  14. Bacteriology of the teeth from a great white shark: potential medical implications for shark bite victims.

    OpenAIRE

    Buck, J D; Spotte, S; Gadbaw, J J

    1984-01-01

    Bacteria were cultured for the first time from the teeth of a great white shark (Carcharodon carcharias). Isolates included Vibrio alginolyticus, Vibrio fluvialis, Vibrio parahaemolyticus, and other genera. All are common in the marine environment and some may be associated with wound infections in humans. Shark bite lacerations may serve as a source of these potentially infectious bacteria, particularly Vibrio spp., and should be treated immediately. Antibiotic susceptibility patterns are sh...

  15. DNA damage-inducible transcript 4 (DDIT4) mediates methamphetamine-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes

    International Nuclear Information System (INIS)

    Chen, Rui; Wang, Bin; Chen, Ling; Cai, Dunpeng; Li, Bing; Chen, Chuanxiang; Huang, Enping; Liu, Chao; Lin, Zhoumeng; Xie, Wei-Bing; Wang, Huijun

    2016-01-01

    Methamphetamine (METH) is an amphetamine-like psychostimulant that is commonly abused. Previous studies have shown that METH can induce damages to the nervous system and recent studies suggest that METH can also cause adverse and potentially lethal effects on the cardiovascular system. Recently, we demonstrated that DNA damage-inducible transcript 4 (DDIT4) regulates METH-induced neurotoxicity. However, the role of DDIT4 in METH-induced cardiotoxicity remains unknown. We hypothesized that DDIT4 may mediate METH-induced autophagy and apoptosis in cardiomyocytes. To test the hypothesis, we examined DDIT4 protein express