151
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Liu AP, Botelho RJ, Antonescu CN. The big and intricate dreams of little organelles: Embracing complexity in the study of membrane traffic. Traffic 2017; 18:567-579. [DOI: 10.1111/tra.12497] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 05/30/2017] [Accepted: 05/30/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Allen P. Liu
- Department of Mechanical Engineering University of Michigan Ann Arbor Michigan
- Department of Biomedical Engineering University of Michigan Ann Arbor Michigan
- Cellular and Molecular Biology Program University of Michigan Ann Arbor Michigan
- Biophysics Program University of Michigan Ann Arbor Michigan
| | - Roberto J. Botelho
- The Graduate Program in Molecular Science and Department of Chemistry and Biology Ryerson University Toronto Canada
| | - Costin N. Antonescu
- The Graduate Program in Molecular Science and Department of Chemistry and Biology Ryerson University Toronto Canada
- Keenan Research Centre for Biomedical Science St. Michael's Hospital Toronto Canada
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152
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Rosario FJ, Nathanielsz PW, Powell TL, Jansson T. Maternal folate deficiency causes inhibition of mTOR signaling, down-regulation of placental amino acid transporters and fetal growth restriction in mice. Sci Rep 2017. [PMID: 28638048 PMCID: PMC5479823 DOI: 10.1038/s41598-017-03888-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Maternal folate deficiency is linked to restricted fetal growth, however the underlying mechanisms remain to be established. Here we tested the hypothesis that mTOR functions as a folate sensor in vivo in mice and that maternal folate deficiency inhibits placental mTOR signaling and amino acid transporter activity and causes fetal growth restriction. Folate deficient mice had lower serum folate (−60%). In late pregnancy, fetal weight in the folate deficient group was decreased (−17%, p < 0.05), whereas placental weight, litter size and crown rump length were unaltered. Maternal folate deficiency inhibited placental mTORC1 and mTORC2 signaling and decreased trophoblast plasma membrane System A and L amino acid transporter activities and transporter isoform expression. Folate deficiency also caused a decrease in phosphorylation of specific functional readouts of mTORC1 and mTORC2 signaling in multiple maternal and fetal tissues. We have identified a novel specific molecular link between maternal folate availability and fetal growth, involving regulation of placental mTOR signaling by folate, resulting in changes in placental nutrient transport. mTOR folate sensing may have broad biological significance because of the critical role of folate in normal cell function and the wide range of disorders, including cancer, that have been linked to folate availability.
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Affiliation(s)
- Fredrick J Rosario
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
| | - Peter W Nathanielsz
- Department of Animal Science, University of Wyoming, Laramsie, WY, 82071, USA.,Southwest National Primate Research Center, San Antonio, TX, 78249, USA
| | - Theresa L Powell
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.,Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Thomas Jansson
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
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153
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Wang A, Carraro-Lacroix LR, Owen C, Gao B, Corey PN, Tyrrell P, Brumell JH, Voronov I. Activity-independent targeting of mTOR to lysosomes in primary osteoclasts. Sci Rep 2017; 7:3005. [PMID: 28592812 PMCID: PMC5462732 DOI: 10.1038/s41598-017-03494-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 04/28/2017] [Indexed: 12/14/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) is activated by numerous stimuli, including amino acids and growth factors. This kinase is part of the mTOR complex 1 (mTORC1) which regulates cell proliferation, differentiation, and autophagy. Active mTORC1 is located on lysosomes and has been reported to disassociate from the lysosomal surface in the absence of amino acids. Furthermore, mTORC1 activity has been linked to the vacuolar H+-ATPases (V-ATPases), the proton pumps responsible for lysosomal acidification; however, the exact role of the V-ATPases in mTORC1 signaling is not known. To elucidate the mechanisms involved in mTORC1 regulation by the V-ATPases, we used primary osteoclasts derived from mice carrying a point (R740S) mutation in the a3 subunit of the V-ATPase. In these cells, the mutant protein is expressed but the pump is not functional, resulting in higher lysosomal pH. By analyzing mTOR activation, mTOR/lysosome co-localization, and lysosomal positioning using confocal microscopy, fractionation, and ultrapure lysosomal purification methods, we demonstrate that in primary osteoclasts, mTOR is localized on the lysosomal surface even when mTOR activity is inhibited. Our findings reveal that mTOR targeting to the lysosome in osteoclasts is activity-independent, and that its disassociation from the lysosome during starvation is not universal.
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Affiliation(s)
- Andrew Wang
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | | | - Celeste Owen
- Centre for Modeling Human Disease, Samuel Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Bowen Gao
- Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada
| | - Paul N Corey
- Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada
| | - Pascal Tyrrell
- Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | - John H Brumell
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Irina Voronov
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
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154
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Fabiani IM, Rocha SL. Avaliação do tratamento da sepse com glutamina via enteral em ratos. Rev Col Bras Cir 2017; 44:231-237. [DOI: 10.1590/0100-69912017003002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 12/22/2016] [Indexed: 11/22/2022] Open
Abstract
RESUMO Objetivo: analisar a influência da glutamina nas alterações morfo-histológicas observadas em íleo, pulmão, rim e fígado de ratos Wistar submetidos à sepse. Métodos: a sepse foi induzida por meio de ligadura e punção do ceco. Os animais foram divididos em dois grupos: grupo A, controle, com cinco animais, e grupo B, experimento, com dez animais que utilizaram previamente glutamina por dois dias por via enteral. Na análise histológica, classificou-se as lesões de acordo com um escore cujo valor atribuído dependia da gravidade da lesão e do órgão acometido. A somatória dos valores atribuídos a cada animal resultou em sua nota final. No íleo, avaliaram-se as vilosidades; no fígado, esteatose microgoticular; no pulmão, pneumonite intersticial; e no rim, vacuolização dos túbulos contorcidos proximais. Resultados: a lise celular e a destruição das vilosidades no íleo do grupo controle foram mais intensas em relação aos animais que receberam glutamina. No rim, verificou-se vacuolização mais acentuada dos túbulos contorcidos proximais no grupo controle em relação aos animais que receberam glutamina. Tanto a esteatose microgoticular como a pneumonite intersticial mostraram-se semelhantes em ambos os grupos. Conclusão: o uso de glutamina via enteral previamente à sepse na dose de 0,5 g/kg/dia preservou de maneira significativa a estrutura histológica do intestino delgado e os rins em ratos.
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155
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Lin F. Autophagy in renal tubular injury and repair. Acta Physiol (Oxf) 2017; 220:229-237. [PMID: 28112877 PMCID: PMC7814874 DOI: 10.1111/apha.12852] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/18/2017] [Accepted: 01/18/2017] [Indexed: 02/06/2023]
Abstract
Autophagy is a fundamental cellular process that maintains normal function and structure of the cell. It can be induced during stress and serves as an adaptive response for cell survival. Normal kidneys have high metabolic demands yet are relatively hypoxic, especially in the medulla and papilla. Injury or ageing aggravates metabolic perturbation and activates autophagy in many types of renal cells. In the kidney, tubular epithelial cells consume the most energy due to active transport mechanisms and therefore are the most susceptible to injuries from hypoxic or low-energy states. This brief review will summarize current understandings of the biological function and molecular regulation of epithelial autophagy during tubular injury and repair.
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Affiliation(s)
- F Lin
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY, USA
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156
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Rosario FJ, Powell TL, Jansson T. mTOR folate sensing links folate availability to trophoblast cell function. J Physiol 2017; 595:4189-4206. [PMID: 28374905 DOI: 10.1113/jp272424] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 03/29/2017] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Folate deficiency during pregnancy is associated with restricted fetal growth, although the underlying mechanisms are poorly understood. Here we show that mechanistic target of rapamycin (mTOR) functions as a folate sensor in primary human trophoblast (PHT) cells. Folate sensing by mTOR in PHT cells involves both mTOR Complex 1 and 2 and requires the proton-coupled folate transporter. We report a previously unknown molecular mechanism by which folate regulates trophoblast cell function. Because mTOR is a positive regulator of placental amino acid transport and mitochondrial function, placental mTOR folate sensing may constitute the mechanistic link between maternal folate status and fetal growth. These findings provide new insight into how folate influences human cell physiology and may have implications for our understanding of how altered folate availability causes diseases such as fetal growth restriction, fetal malformations and cancer. ABSTRACT Folate is a water-soluble B vitamin that is essential for cellular methylation reactions and DNA synthesis and repair. Low maternal folate levels in pregnancy are associated with fetal growth restriction, but the underlying mechanisms are poorly understood. Mechanistic target of rapamycin (mTOR) links nutrient availability to cell growth and function by regulating gene expression and protein translation. Here we show that mTOR functions as a folate sensor in primary human trophoblast (PHT) cells. Folate deficiency in PHT cells caused inhibition of mTOR signalling and decreased the activity of key amino acid transporters. Folate sensing by mTOR in PHT cells involves both mTOR Complex 1 and 2 and requires the proton-coupled folate transporter (PCFT, SLC46A1). The involvement of PCFT in mTOR folate sensing is not dependent on its function as a plasma membrane folate transporter. Increasing levels of homocysteine had no effect on PHT mTOR signalling, suggesting that mTOR senses low folate rather than high homocysteine. In addition, we demonstrate that maternal serum folate is positively correlated to placental mTORC1 and mTORC2 signalling activity in human pregnancy. We have identified a previously unknown molecular link between folate availability and cell function involving PCFT and mTOR signalling. We propose that mTOR folate sensing in trophoblast cells matches placental nutrient transport, and therefore fetal growth, to folate availability. These findings may have implications for our understanding of how altered folate availability causes human diseases such as fetal growth restriction, fetal malformations and cancer.
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Affiliation(s)
- Fredrick J Rosario
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Theresa L Powell
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.,Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Thomas Jansson
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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157
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Abstract
Lysosomes are digestive organelles of the endocytic and autophagic pathways. Increasing lysosome enzyme activities could help to clear pathological cellular waste. A recent study shows that lysosomal digestive functions can be promoted in isolated cells and mice by pharmacologically stimulating the autophagy- and lysosome-regulating transcription factors TFEB and ZKSCAN3 through previously unrecognized mTORC1-independent pathways acting via PKC.
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Affiliation(s)
- Paul Saftig
- Biochemical Institute of the Christian-Albrechts University Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Albert Haas
- Institute for Cell Biology of the Rheinische Friedrich-Wilhelms University Bonn, D-53121 Bonn, Germany
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158
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Abstract
Epidemiological evidence links an individual's susceptibility to chronic disease in adult life to events during their intrauterine phase of development. Biologically this should not be unexpected, for organ systems are at their most plastic when progenitor cells are proliferating and differentiating. Influences operating at this time can permanently affect their structure and functional capacity, and the activity of enzyme systems and endocrine axes. It is now appreciated that such effects lay the foundations for a diverse array of diseases that become manifest many years later, often in response to secondary environmental stressors. Fetal development is underpinned by the placenta, the organ that forms the interface between the fetus and its mother. All nutrients and oxygen reaching the fetus must pass through this organ. The placenta also has major endocrine functions, orchestrating maternal adaptations to pregnancy and mobilizing resources for fetal use. In addition, it acts as a selective barrier, creating a protective milieu by minimizing exposure of the fetus to maternal hormones, such as glucocorticoids, xenobiotics, pathogens, and parasites. The placenta shows a remarkable capacity to adapt to adverse environmental cues and lessen their impact on the fetus. However, if placental function is impaired, or its capacity to adapt is exceeded, then fetal development may be compromised. Here, we explore the complex relationships between the placental phenotype and developmental programming of chronic disease in the offspring. Ensuring optimal placentation offers a new approach to the prevention of disorders such as cardiovascular disease, diabetes, and obesity, which are reaching epidemic proportions.
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Affiliation(s)
- Graham J Burton
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
| | - Abigail L Fowden
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
| | - Kent L Thornburg
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
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159
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Liu Y, von Wirén N. Ammonium as a signal for physiological and morphological responses in plants. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2581-2592. [PMID: 28369490 DOI: 10.1093/jxb/erx086] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Ammonium is a major inorganic nitrogen source for plants. At low external supplies, ammonium promotes plant growth, while at high external supplies it causes toxicity. Ammonium triggers rapid changes in cytosolic pH, in gene expression, and in post-translational modifications of proteins, leading to apoplastic acidification, co-ordinated ammonium uptake, enhanced ammonium assimilation, altered oxidative and phytohormonal status, and reshaped root system architecture. Some of these responses are dependent on AMT-type ammonium transporters and are not linked to a nutritional effect, indicating that ammonium is perceived as a signaling molecule by plant cells. This review summarizes current knowledge of ammonium-triggered physiological and morphological responses and highlights existing and putative mechanisms mediating ammonium signaling and sensing events in plants. We put forward the hypothesis that sensing of ammonium takes place at multiple steps along its transport, storage, and assimilation pathways.
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Affiliation(s)
- Ying Liu
- Molecular Plant Nutrition, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Stadt Seeland, OT Gatersleben, Germany
| | - Nicolaus von Wirén
- Molecular Plant Nutrition, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Stadt Seeland, OT Gatersleben, Germany
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160
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FoxO3a suppression and VPS34 activity are essential to anti-atrophic effects of leucine in skeletal muscle. Cell Tissue Res 2017; 369:381-394. [PMID: 28436000 DOI: 10.1007/s00441-017-2614-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 03/21/2017] [Indexed: 12/30/2022]
Abstract
Our aim is to gain insight into the mechanisms underlying the anti-atrophic effects of leucine, namely, the way that this amino acid can restrain the up-regulation of MuRF1 and Mafbx/Atrogin-1 in muscle atrophy. Male rats received dietary leucine supplementation for 1-3 days, during which time their hind limbs were immobilized. Our results showed that leucine inhibited Forkhead Box O3 (FoxO3a) translocation to cell nuclei. In addition, leucine was able to reverse the expected reduction of FoXO3a ubiquitination caused by immobilization. Unexpectedly, leucine promoted these effects independently of the Class I PI3K/Akt pathway. Vacuolar protein sorting 34 (VPS34; a Class III PI3K) was strongly localized in nuclei after immobilization and leucine supplementation was able to prevent this effect. In experiments on cultured primary myotubes, dexamethasone led to the localization of VPS34 in the nucleus. In addition, the pharmacological inhibition of VPS34 blocked VPS34 nuclear localization and impaired the protective effect of leucine upon myotube trophicity. Finally, the pharmacological inhibition of VPS34 in primary myotubes prevented the protective effects of leucine upon MuRF1 and Mafbx/Atrogin-1 gene expression. Autophagy-related target genes were not responsive to leucine. Thus, we demonstrate that the anti-atrophic effect of leucine is dependent upon FoxO3a suppression and VPS34 activity.
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161
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Lee HO, Uzzo RG, Kister D, Kruger WD. Combination of serum histidine and plasma tryptophan as a potential biomarker to detect clear cell renal cell carcinoma. J Transl Med 2017; 15:72. [PMID: 28385150 PMCID: PMC5383954 DOI: 10.1186/s12967-017-1178-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 04/01/2017] [Indexed: 11/26/2022] Open
Abstract
Background In previous work, we showed that serum-free amino acid (SFAA) profiles were different between kidney cancer patients and age and sex matched controls. The goals of the current study are to: (1) confirm our initial observation on an independent sample set; (2) examine if there were similar differences in plasma-free amino acids (PFAA); and (3) determine if removal of tumors changed SFAA and PFAA profiles. Methods SFAA and PFAA profiles were measured in 484 samples taken from 124 healthy controls and 56 clear cell renal cell carcinoma (ccRCC) patients both before and after resection of renal tumors. Results SFAA and PFAA profiles taken from identical blood samples were remarkably different, with the mean individual amino acid concentrations being 40% less in plasma compared to serum. Both SFAA and PFAA profiles differed significantly between ccRCC patients and controls, but the individual amino acids that differed the most, and the direction of the changes, were quite different between the two blood components. Removal of the tumor had almost no effect on either the SFAA or PFAA profiles. A logistic regression model using serum histidine and plasma tryptophan correctly classified 85.5% of control and 84.7% of case samples. Conclusions Our findings show that that tumor mass is not directly linked to alterations in blood amino acid levels, and that a combination of serum histidine and plasma tryptophan may be useful as a biomarker to detect ccRCC. Electronic supplementary material The online version of this article (doi:10.1186/s12967-017-1178-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hyung-Ok Lee
- Cancer Biology Program, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA, 19111, USA
| | - Robert G Uzzo
- Department of Surgical Oncology, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA, 19111, USA
| | - Debra Kister
- Department of Surgical Oncology, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA, 19111, USA
| | - Warren D Kruger
- Cancer Biology Program, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA, 19111, USA.
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162
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Ben-Sahra I, Manning BD. mTORC1 signaling and the metabolic control of cell growth. Curr Opin Cell Biol 2017; 45:72-82. [PMID: 28411448 PMCID: PMC5545101 DOI: 10.1016/j.ceb.2017.02.012] [Citation(s) in RCA: 407] [Impact Index Per Article: 58.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 02/05/2017] [Accepted: 02/17/2017] [Indexed: 01/25/2023]
Abstract
mTOR [mechanistic target of rapamycin] is a serine/threonine protein kinase that, as part of mTORC1 (mTOR complex 1), acts as an important molecular connection between nutrient signals and the metabolic processes indispensable for cell growth. While there has been pronounced interest in the upstream mechanisms regulating mTORC1, the full range of downstream molecular targets through which mTORC1 signaling stimulates cell growth is only recently emerging. It is now evident that mTORC1 promotes cell growth primarily through the activation of key anabolic processes. Through a diverse set of downstream targets, mTORC1 promotes the biosynthesis of macromolecules, including proteins, lipids, and nucleotides to build the biomass underlying cell, tissue, and organismal growth. Here, we focus on the metabolic functions of mTORC1 as they relate to the control of cell growth. As dysregulated mTORC1 underlies a variety of human diseases, including cancer, diabetes, autoimmune diseases, and neurological disorders, understanding the metabolic program downstream of mTORC1 provides insights into its role in these pathological states.
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Affiliation(s)
- Issam Ben-Sahra
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Brendan D Manning
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
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163
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Cobley D, Hálová L, Schauries M, Kaczmarek A, Franz-Wachtel M, Du W, Krug K, Maček B, Petersen J. Ste12/Fab1 phosphatidylinositol-3-phosphate 5-kinase is required for nitrogen-regulated mitotic commitment and cell size control. PLoS One 2017; 12:e0172740. [PMID: 28273166 PMCID: PMC5342193 DOI: 10.1371/journal.pone.0172740] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/08/2017] [Indexed: 11/18/2022] Open
Abstract
Tight coupling of cell growth and cell cycle progression enable cells to adjust their rate of division, and therefore size, to the demands of proliferation in varying nutritional environments. Nutrient stress promotes inhibition of Target Of Rapamycin Complex 1 (TORC1) activity. In fission yeast, reduced TORC1 activity advances mitotic onset and switches growth to a sustained proliferation at reduced cell size. A screen for mutants, that failed to advance mitosis upon nitrogen stress, identified a mutant in the PIKFYVE 1-phosphatidylinositol-3-phosphate 5-kinase fission yeast homolog Ste12. Ste12PIKFYVE deficient mutants were unable to advance the cell cycle to reduce cell size after a nitrogen downshift to poor nitrogen (proline) growth conditions. While it is well established that PI(3,5)P2 signalling is required for autophagy and that Ste12PIKFYVE mutants have enlarged vacuoles (yeast lysosomes), neither a block to autophagy or mutants that independently have enlarged vacuoles had any impact upon nitrogen control of mitotic commitment. The addition of rapamycin to Ste12PIKFYVE deficient mutants reduced cell size at division to suggest that Ste12PIKFYVE possibly functions upstream of TORC1. ste12 mutants display increased Torin1 (TOR inhibitor) sensitivity. However, no major impact on TORC1 or TORC2 activity was observed in the ste12 deficient mutants. In summary, Ste12PIKFYVE is required for nitrogen-stress mediated advancement of mitosis to reduce cell size at division.
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Affiliation(s)
- David Cobley
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Lenka Hálová
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Marie Schauries
- Flinders Centre for Innovation in Cancer, School of Medicine, Flinders University, Adelaide, SA, Australia
| | - Adrian Kaczmarek
- Flinders Centre for Innovation in Cancer, School of Medicine, Flinders University, Adelaide, SA, Australia
| | | | - Wei Du
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Karsten Krug
- Proteome Center Tübingen, Auf der Morgenstelle, Tuebingen, Germany
| | - Boris Maček
- Proteome Center Tübingen, Auf der Morgenstelle, Tuebingen, Germany
| | - Janni Petersen
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
- Flinders Centre for Innovation in Cancer, School of Medicine, Flinders University, Adelaide, SA, Australia
- South Australia Health and Medical Research Institute, North Terrace, Adelaide SA Australia
- * E-mail:
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164
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Duan YH, Li FN, Wen CY, Wang WL, Guo QP, Li YH, Yin YL. Branched-chain amino acid ratios in low-protein diets regulate the free amino acid profile and the expression of hepatic fatty acid metabolism-related genes in growing pigs. J Anim Physiol Anim Nutr (Berl) 2017; 102:e43-e51. [DOI: 10.1111/jpn.12698] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/20/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Y. H. Duan
- Key Laboratory of Agro-ecological Processes in Subtropical Region; Institute of Subtropical Agriculture; Chinese Academy of Sciences; Changsha Hunan China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Changsha Hunan China
- Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Changsha Hunan China
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central; Ministry of Agriculture; Changsha Hunan China
- University of Chinese Academy of Sciences; Beijing China
| | - F. N. Li
- Key Laboratory of Agro-ecological Processes in Subtropical Region; Institute of Subtropical Agriculture; Chinese Academy of Sciences; Changsha Hunan China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Changsha Hunan China
- Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Changsha Hunan China
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central; Ministry of Agriculture; Changsha Hunan China
- Hunan Co-Innovation Center of Animal Production Safety; CICAPS; Changsha Hunan China. Hunan Collaborative Innovation Center for Utilization of Botanical Functional Ingredients; Changsha Hunan China
| | - C. Y. Wen
- Laboratory of Animal Nutrition and Human Health; School of Biology; Hunan Normal University; Changsha Hunan China
| | - W. L. Wang
- Laboratory of Animal Nutrition and Human Health; School of Biology; Hunan Normal University; Changsha Hunan China
| | - Q. P. Guo
- Key Laboratory of Agro-ecological Processes in Subtropical Region; Institute of Subtropical Agriculture; Chinese Academy of Sciences; Changsha Hunan China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Changsha Hunan China
- Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Changsha Hunan China
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central; Ministry of Agriculture; Changsha Hunan China
- University of Chinese Academy of Sciences; Beijing China
| | - Y. H. Li
- Key Laboratory of Agro-ecological Processes in Subtropical Region; Institute of Subtropical Agriculture; Chinese Academy of Sciences; Changsha Hunan China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Changsha Hunan China
- Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Changsha Hunan China
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central; Ministry of Agriculture; Changsha Hunan China
- University of Chinese Academy of Sciences; Beijing China
| | - Y. L. Yin
- Key Laboratory of Agro-ecological Processes in Subtropical Region; Institute of Subtropical Agriculture; Chinese Academy of Sciences; Changsha Hunan China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Changsha Hunan China
- Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Changsha Hunan China
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central; Ministry of Agriculture; Changsha Hunan China
- Laboratory of Animal Nutrition and Human Health; School of Biology; Hunan Normal University; Changsha Hunan China. College of Animal Science; South China Agricultural University; Guangzhou China
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165
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Menon D, Salloum D, Bernfeld E, Gorodetsky E, Akselrod A, Frias MA, Sudderth J, Chen PH, DeBerardinis R, Foster DA. Lipid sensing by mTOR complexes via de novo synthesis of phosphatidic acid. J Biol Chem 2017; 292:6303-6311. [PMID: 28223357 DOI: 10.1074/jbc.m116.772988] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/10/2017] [Indexed: 11/06/2022] Open
Abstract
mTOR, the mammalian target of rapamycin, integrates growth factor and nutrient signals to promote a transformation from catabolic to anabolic metabolism, cell growth, and cell cycle progression. Phosphatidic acid (PA) interacts with the FK506-binding protein-12-rapamycin-binding (FRB) domain of mTOR, which stabilizes both mTOR complexes: mTORC1 and mTORC2. We report here that mTORC1 and mTORC2 are activated in response to exogenously supplied fatty acids via the de novo synthesis of PA, a central metabolite for membrane phospholipid biosynthesis. We examined the impact of exogenously supplied fatty acids on mTOR in KRas-driven cancer cells, which are programmed to utilize exogenous lipids. The induction of mTOR by oleic acid was dependent upon the enzymes responsible for de novo synthesis of PA. Suppression of the de novo synthesis of PA resulted in G1 cell cycle arrest. Although it has long been appreciated that mTOR is a sensor of amino acids and glucose, this study reveals that mTOR also senses the presence of lipids via production of PA.
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Affiliation(s)
- Deepak Menon
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065.,the Biochemistry Program and
| | - Darin Salloum
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065.,the Biology Program, Graduate Center of the City University of New York, New York, New York 10016
| | - Elyssa Bernfeld
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065.,the Biochemistry Program and
| | - Elizabeth Gorodetsky
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065
| | - Alla Akselrod
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065
| | - Maria A Frias
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065
| | - Jessica Sudderth
- the Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Pei-Hsuan Chen
- the Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Ralph DeBerardinis
- the Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - David A Foster
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065, .,the Biochemistry Program and.,the Biology Program, Graduate Center of the City University of New York, New York, New York 10016.,the Department of Pharmacology, Weill Cornell Medicine, New York, New York 10021
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166
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González A, Hall MN. Nutrient sensing and TOR signaling in yeast and mammals. EMBO J 2017; 36:397-408. [PMID: 28096180 DOI: 10.15252/embj.201696010] [Citation(s) in RCA: 489] [Impact Index Per Article: 69.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/12/2016] [Accepted: 12/15/2016] [Indexed: 01/13/2023] Open
Abstract
Coordinating cell growth with nutrient availability is critical for cell survival. The evolutionarily conserved TOR (target of rapamycin) controls cell growth in response to nutrients, in particular amino acids. As a central controller of cell growth, mTOR (mammalian TOR) is implicated in several disorders, including cancer, obesity, and diabetes. Here, we review how nutrient availability is sensed and transduced to TOR in budding yeast and mammals. A better understanding of how nutrient availability is transduced to TOR may allow novel strategies in the treatment for mTOR-related diseases.
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167
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Starved epithelial cells uptake extracellular matrix for survival. Nat Commun 2017; 8:13989. [PMID: 28071763 PMCID: PMC5234072 DOI: 10.1038/ncomms13989] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 11/17/2016] [Indexed: 01/12/2023] Open
Abstract
Extracellular matrix adhesion is required for normal epithelial cell survival, nutrient uptake and metabolism. This requirement can be overcome by oncogene activation. Interestingly, inhibition of PI3K/mTOR leads to apoptosis of matrix-detached, but not matrix-attached cancer cells, suggesting that matrix-attached cells use alternate mechanisms to maintain nutrient supplies. Here we demonstrate that under conditions of dietary restriction or growth factor starvation, where PI3K/mTOR signalling is decreased, matrix-attached human mammary epithelial cells upregulate and internalize β4-integrin along with its matrix substrate, laminin. Endocytosed laminin localizes to lysosomes, results in increased intracellular levels of essential amino acids and enhanced mTORC1 signalling, preventing cell death. Moreover, we show that starved human fibroblasts secrete matrix proteins that maintain the growth of starved mammary epithelial cells contingent upon epithelial cell β4-integrin expression. Our study identifies a crosstalk between stromal fibroblasts and epithelial cells under starvation that could be exploited therapeutically to target tumours resistant to PI3K/mTOR inhibition. Inhibition of PI3K/mTOR, which mimics nutrient starvation, causes death of detached but not matrix-attached cancer cells. Here the authors show that nutrient restriction of epithelial cells causes uptake of the matrix protein laminin, which results in increased intracellular amino acids and enhanced mTORC1 signalling.
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168
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Satoh N, Suzuki M, Nakamura M, Suzuki A, Horita S, Seki G, Moriya K. Functional coupling of V-ATPase and CLC-5. World J Nephrol 2017; 6:14-20. [PMID: 28101447 PMCID: PMC5215204 DOI: 10.5527/wjn.v6.i1.14] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/04/2016] [Accepted: 11/02/2016] [Indexed: 02/06/2023] Open
Abstract
Dent’s disease is an X-linked renal tubulopathy characterized by low molecular weight proteinuria, hypercalciuria and progressive renal failure. Disease aetiology is associated with mutations in the CLCN5 gene coding for the electrogenic 2Cl-/H+ antiporter chloride channel 5 (CLC-5), which is expressed in the apical endosomes of renal proximal tubules with the vacuolar type H+-ATPase (V-ATPase). Initially identified as a member of the CLC family of Cl- channels, CLC-5 was presumed to provide Cl- shunt into the endosomal lumen to dissipate H+ accumulation by V-ATPase, thereby facilitating efficient endosomal acidification. However, recent findings showing that CLC-5 is in fact not a Cl- channel but a 2Cl-/H+ antiporter challenged this classical shunt model, leading to a renewed and intense debate on its physiological roles. Cl- accumulation via CLC-5 is predicted to play a critical role in endocytosis, as illustrated in mice carrying an artificial Cl- channel mutation E211A that developed defective endocytosis but normal endosomal acidification. Conversely, a recent functional analysis of a newly identified disease-causing Cl- channel mutation E211Q in a patient with typical Dent’s disease confirmed the functional coupling between V-ATPase and CLC-5 in endosomal acidification, lending support to the classical shunt model. In this editorial, we will address the current recognition of the physiological role of CLC-5 with a specific focus on the functional coupling of V-ATPase and CLC-5.
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169
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Wu J, de Theije CGM, da Silva SL, Abbring S, van der Horst H, Broersen LM, Willemsen L, Kas M, Garssen J, Kraneveld AD. Dietary interventions that reduce mTOR activity rescue autistic-like behavioral deficits in mice. Brain Behav Immun 2017; 59:273-287. [PMID: 27640900 DOI: 10.1016/j.bbi.2016.09.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 08/27/2016] [Accepted: 09/15/2016] [Indexed: 02/07/2023] Open
Abstract
Enhanced mammalian target of rapamycin (mTOR) signaling in the brain has been implicated in the pathogenesis of autism spectrum disorder (ASD). Inhibition of the mTOR pathway improves behavior and neuropathology in mouse models of ASD containing mTOR-associated single gene mutations. The current study demonstrated that the amino acids histidine, lysine, threonine inhibited mTOR signaling and IgE-mediated mast cell activation, while the amino acids leucine, isoleucine, valine had no effect on mTOR signaling in BMMCs. Based on these results, we designed an mTOR-targeting amino acid diet (Active 1 diet) and assessed the effects of dietary interventions with the amino acid diet or a multi-nutrient supplementation diet (Active 2 diet) on autistic-like behavior and mTOR signaling in food allergic mice and in inbred BTBR T+Itpr3tf/J mice. Cow's milk allergic (CMA) or BTBR male mice were fed a Control, Active 1, or Active 2 diet for 7 consecutive weeks. CMA mice showed reduced social interaction and increased self-grooming behavior. Both diets reversed behavioral impairments and inhibited the mTOR activity in the prefrontal cortex and amygdala of CMA mice. In BTBR mice, only Active 1 diet reduced repetitive self-grooming behavior and attenuated the mTOR activity in the prefrontal and somatosensory cortices. The current results suggest that activated mTOR signaling pathway in the brain may be a convergent pathway in the pathogenesis of ASD bridging genetic background and environmental triggers (food allergy) and that mTOR over-activation could serve as a potential therapeutic target for the treatment of ASD.
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Affiliation(s)
- Jiangbo Wu
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Caroline G M de Theije
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Sofia Lopes da Silva
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, The Netherlands
| | - Suzanne Abbring
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Hilma van der Horst
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Laus M Broersen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, The Netherlands
| | - Linette Willemsen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Martien Kas
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands; Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Johan Garssen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, The Netherlands
| | - Aletta D Kraneveld
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
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170
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Subcellular Trafficking of Mammalian Lysosomal Proteins: An Extended View. Int J Mol Sci 2016; 18:ijms18010047. [PMID: 28036022 PMCID: PMC5297682 DOI: 10.3390/ijms18010047] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 12/15/2016] [Accepted: 12/18/2016] [Indexed: 01/02/2023] Open
Abstract
Lysosomes clear macromolecules, maintain nutrient and cholesterol homeostasis, participate in tissue repair, and in many other cellular functions. To assume these tasks, lysosomes rely on their large arsenal of acid hydrolases, transmembrane proteins and membrane-associated proteins. It is therefore imperative that, post-synthesis, these proteins are specifically recognized as lysosomal components and are correctly sorted to this organelle through the endosomes. Lysosomal transmembrane proteins contain consensus motifs in their cytosolic regions (tyrosine- or dileucine-based) that serve as sorting signals to the endosomes, whereas most lysosomal acid hydrolases acquire mannose 6-phosphate (Man-6-P) moieties that mediate binding to two membrane receptors with endosomal sorting motifs in their cytosolic tails. These tyrosine- and dileucine-based motifs are tickets for boarding in clathrin-coated carriers that transport their cargo from the trans-Golgi network and plasma membrane to the endosomes. However, increasing evidence points to additional mechanisms participating in the biogenesis of lysosomes. In some cell types, for example, there are alternatives to the Man-6-P receptors for the transport of some acid hydrolases. In addition, several “non-consensus” sorting motifs have been identified, and atypical transport routes to endolysosomes have been brought to light. These “unconventional” or “less known” transport mechanisms are the focus of this review.
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171
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van Niekerk G, Loos B, Nell T, Engelbrecht AM. Autophagy--A free meal in sickness-associated anorexia. Autophagy 2016; 12:727-34. [PMID: 27050464 DOI: 10.1080/15548627.2016.1147672] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Activation of the immune system is metabolically costly, yet a hallmark of an infection is a reduction in appetite with a subsequent reduction in metabolite provision. What is the functional value of decreasing nutrient intake when an infection imposes large demands on metabolic parameters? Here, we propose that sickness-associated anorexia (SAA) upregulates the ancient process of autophagy systemically, thereby profoundly controlling not only immune- but also nonimmune-competent cells. This allows an advanced impact on the resolution of an infection through direct pathogen killing, enhancement of epitope presentation and the contribution toward the clearance of noxious factors. By rendering a 'free meal,' autophagy is thus most fundamentally harnessed during an anorexic response in order to promote both host tolerance and resistance. These findings strongly suggest a reassessment of numerous SAA-related clinical applications and a re-evaluation of current efforts in patient care.
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Affiliation(s)
- Gustav van Niekerk
- a Department of Physiological Sciences , Stellenbosch University , Stellenbosch , South Africa
| | - Ben Loos
- b Department of Physiological Sciences , Faculty of Natural Sciences, Stellenbosch University , Stellenbosch , South Africa
| | - Theo Nell
- b Department of Physiological Sciences , Faculty of Natural Sciences, Stellenbosch University , Stellenbosch , South Africa
| | - Anna-Mart Engelbrecht
- b Department of Physiological Sciences , Faculty of Natural Sciences, Stellenbosch University , Stellenbosch , South Africa
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172
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Selective Lysosomal Transporter Degradation by Organelle Membrane Fusion. Dev Cell 2016; 40:151-167. [PMID: 28017618 DOI: 10.1016/j.devcel.2016.11.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/19/2016] [Accepted: 11/28/2016] [Indexed: 12/20/2022]
Abstract
Lysosomes rely on their resident transporter proteins to return products of catabolism to the cell for reuse and for cellular signaling, metal storage, and maintaining the lumenal environment. Despite their importance, little is known about the lifetime of these transporters or how they are regulated. Using Saccharomyces cerevisiae as a model, we discovered a new pathway intrinsic to homotypic lysosome membrane fusion that is responsible for their degradation. Transporter proteins are selectively sorted by the docking machinery into an area between apposing lysosome membranes, which is internalized and degraded by lumenal hydrolases upon organelle fusion. These proteins have diverse lifetimes that are regulated in response to protein misfolding, changing substrate levels, or TOR activation. Analogous to endocytosis for controlling surface protein levels, the "intralumenal fragment pathway" is critical for lysosome membrane remodeling required for organelle function in the context of cellular protein quality control, ion homeostasis, and metabolism.
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173
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Fritsch SD, Weichhart T. Effects of Interferons and Viruses on Metabolism. Front Immunol 2016; 7:630. [PMID: 28066439 PMCID: PMC5174094 DOI: 10.3389/fimmu.2016.00630] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/08/2016] [Indexed: 12/12/2022] Open
Abstract
Interferons (IFNs) are potent pleiotropic cytokines that broadly alter cellular functions in response to viral and other infections. These alterations include changes in protein synthesis, proliferation, membrane composition, and the nutritional microenvironment. Recent evidence suggests that antiviral responses are supported by an IFN-induced rewiring of the cellular metabolism. In this review, we discuss the roles of type I and type II IFNs in regulating the cellular metabolism and biosynthetic reactions. Furthermore, we give an overview of how viruses themselves affect these metabolic activities to promote their replication. In addition, we focus on the lipid as well as amino acid metabolisms, through which IFNs exert potent antiviral and immunomodulatory activities. Conversely, the expression of IFNs is controlled by the nutrient sensor mammalian target of rapamycin or by direct reprograming of lipid metabolic pathways. These findings establish a mutual relationship between IFN production and metabolic core processes.
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Affiliation(s)
| | - Thomas Weichhart
- Institute of Medical Genetics, Medical University of Vienna , Vienna , Austria
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174
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Cherqui S, Courtoy PJ. The renal Fanconi syndrome in cystinosis: pathogenic insights and therapeutic perspectives. Nat Rev Nephrol 2016; 13:115-131. [PMID: 27990015 DOI: 10.1038/nrneph.2016.182] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cystinosis is an autosomal recessive metabolic disease that belongs to the family of lysosomal storage disorders. It is caused by a defect in the lysosomal cystine transporter, cystinosin, which results in an accumulation of cystine in all organs. Despite the ubiquitous expression of cystinosin, a renal Fanconi syndrome is often the first manifestation of cystinosis, usually presenting within the first year of life and characterized by the early and severe dysfunction of proximal tubule cells, highlighting the unique vulnerability of this cell type. The current therapy for cystinosis, cysteamine, facilitates lysosomal cystine clearance and greatly delays progression to kidney failure but is unable to correct the Fanconi syndrome. This Review summarizes decades of studies that have fostered a better understanding of the pathogenesis of the renal Fanconi syndrome associated with cystinosis. These studies have unraveled some of the early molecular changes that occur before the onset of tubular atrophy and identified a role for cystinosin beyond cystine transport, in endolysosomal trafficking and proteolysis, lysosomal clearance, autophagy and the regulation of energy balance. These studies have also led to the identification of new potential therapeutic targets and here, we outline the potential role of stem cell therapy for cystinosis and provide insights into the mechanism of haematopoietic stem cell-mediated kidney protection.
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Affiliation(s)
- Stephanie Cherqui
- Department of Pediatrics, Division of Genetics, University of California San Diego, 9500 Gilman Drive, MC 0734, La Jolla, California 92093-0734, USA
| | - Pierre J Courtoy
- Cell biology, de Duve Institute and Université catholique de Louvain, UCL-Brussels, 75 Avenue Hippocrate, B-1200 Brussels, Belgium
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175
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Patel D, Salloum D, Saqcena M, Chatterjee A, Mroz V, Ohh M, Foster DA. A Late G1 Lipid Checkpoint That Is Dysregulated in Clear Cell Renal Carcinoma Cells. J Biol Chem 2016; 292:936-944. [PMID: 27956548 DOI: 10.1074/jbc.m116.757864] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/09/2016] [Indexed: 12/14/2022] Open
Abstract
Lipids are important nutrients that proliferating cells require to maintain energy homeostasis as well as to build plasma membranes for newly synthesized cells. Previously, we identified nutrient-sensing checkpoints that exist in the latter part of the G1 phase of the cell cycle that are dependent upon essential amino acids, Gln, and finally, a checkpoint mediated by mammalian target of rapamycin (mTOR), which integrates signals from both nutrients and growth factors. In this study, we have identified and temporally mapped a lipid-mediated G1 checkpoint. This checkpoint is located after the Gln checkpoint and before the mTOR-mediated cell cycle checkpoint. Intriguingly, clear cell renal cell carcinoma cells (ccRCC) have a dysregulated lipid-mediated checkpoint due in part to defective phosphatase and tensin homologue (PTEN). When deprived of lipids, instead of arresting in G1, these cells continue to cycle and utilize lipid droplets as a source of lipids. Lipid droplets have been known to maintain endoplasmic reticulum homeostasis and prevent cytotoxic endoplasmic reticulum stress in ccRCC. Dysregulation of the lipid-mediated checkpoint forces these cells to utilize lipid droplets, which could potentially lead to therapeutic opportunities that exploit this property of ccRCC.
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Affiliation(s)
- Deven Patel
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065.,the Biochemistry Program and
| | - Darin Salloum
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065.,Biology Program, Graduate Center of the City University of New York, New York, New York 10016
| | - Mahesh Saqcena
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065.,the Biochemistry Program and
| | - Amrita Chatterjee
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065.,Biology Program, Graduate Center of the City University of New York, New York, New York 10016
| | - Victoria Mroz
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065
| | - Michael Ohh
- the Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David A Foster
- From the Department of Biological Sciences, Hunter College of the City University of New York, New York, New York 10065, .,the Biochemistry Program and.,Biology Program, Graduate Center of the City University of New York, New York, New York 10016.,the Department of Pharmacology, Weill Cornell Medicine, New York, New York 10021, and
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176
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Abstract
p53 that is activated in response to DNA-damaging stress can induce apoptosis or either transient or permanent cell cycle arrests. Apoptosis and permanent cell cycle arrest (senescence) are bona-fide tumor suppressor mechanisms through which p53 inhibits cancer cell survival. In contrast, transient cell cycle arrests induced by p53 can increase survival by allowing cells time to repair their DNA before proceeding with cell division. Mechanisms that control the choice of response to p53 (apoptosis vs arrest) are not fully understood. There is abundant crosstalk between p53 and the IGF-1R/AKT/mTORC1 signaling pathway. Recent studies indicate this crosstalk can determine the choice of response to p53. These findings have clear implications for the potential use of IGF-1R pathway inhibitors against p53 wild-type or p53-null or mutant cancers.
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Affiliation(s)
- Lei Duan
- Rush University Medical Center, Department of Anatomy and Cell Biology, 600 S Paulina Ave., AcFac 507, Chicago, IL 60612
| | - Carl G Maki
- Rush University Medical Center, Department of Anatomy and Cell Biology, 600 S Paulina Ave., AcFac 507, Chicago, IL 60612
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177
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Carmona-Gutierrez D, Hughes AL, Madeo F, Ruckenstuhl C. The crucial impact of lysosomes in aging and longevity. Ageing Res Rev 2016; 32:2-12. [PMID: 27125853 DOI: 10.1016/j.arr.2016.04.009] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 03/26/2016] [Accepted: 04/23/2016] [Indexed: 02/07/2023]
Abstract
Lysosomes are the main catabolic organelles of a cell and play a pivotal role in a plethora of cellular processes, including responses to nutrient availability and composition, stress resistance, programmed cell death, plasma membrane repair, development, and cell differentiation. In line with this pleiotropic importance for cellular and organismal life and death, lysosomal dysfunction is associated with many age-related pathologies like Parkinson's and Alzheimer's disease, as well as with a decline in lifespan. Conversely, targeting lysosomal functional capacity is emerging as a means to promote longevity. Here, we analyze the current knowledge on the prominent influence of lysosomes on aging-related processes, such as their executory and regulatory roles during general and selective macroautophagy, or their storage capacity for amino acids and ions. In addition, we review and discuss the roles of lysosomes as active players in the mechanisms underlying known lifespan-extending interventions like, for example, spermidine or rapamycin administration. In conclusion, this review aims at critically examining the nature and pliability of the different layers, in which lysosomes are involved as a control hub for aging and longevity.
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178
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Colacurcio DJ, Nixon RA. Disorders of lysosomal acidification-The emerging role of v-ATPase in aging and neurodegenerative disease. Ageing Res Rev 2016; 32:75-88. [PMID: 27197071 DOI: 10.1016/j.arr.2016.05.004] [Citation(s) in RCA: 320] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/02/2016] [Accepted: 05/13/2016] [Indexed: 12/21/2022]
Abstract
Autophagy and endocytosis deliver unneeded cellular materials to lysosomes for degradation. Beyond processing cellular waste, lysosomes release metabolites and ions that serve signaling and nutrient sensing roles, linking the functions of the lysosome to various pathways for intracellular metabolism and nutrient homeostasis. Each of these lysosomal behaviors is influenced by the intraluminal pH of the lysosome, which is maintained in the low acidic range by a proton pump, the vacuolar ATPase (v-ATPase). New reports implicate altered v-ATPase activity and lysosomal pH dysregulation in cellular aging, longevity, and adult-onset neurodegenerative diseases, including forms of Parkinson disease and Alzheimer disease. Genetic defects of subunits composing the v-ATPase or v-ATPase-related proteins occur in an increasingly recognized group of familial neurodegenerative diseases. Here, we review the expanding roles of the v-ATPase complex as a platform regulating lysosomal hydrolysis and cellular homeostasis. We discuss the unique vulnerability of neurons to persistent low level lysosomal dysfunction and review recent clinical and experimental studies that link dysfunction of the v-ATPase complex to neurodegenerative diseases across the age spectrum.
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179
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Hu Y, Carraro-Lacroix LR, Wang A, Owen C, Bajenova E, Corey PN, Brumell JH, Voronov I. Lysosomal pH Plays a Key Role in Regulation of mTOR Activity in Osteoclasts. J Cell Biochem 2016. [PMID: 26212375 DOI: 10.1002/jcb.25287] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mammalian target of rapamycin (mTOR) is a serine/threonine kinase involved in the regulation of cell growth. It has been shown to play an important role in osteoclast differentiation, particularly at the earlier stages of osteoclastogenesis. mTOR activation and function, as part of mTORC1 complex, is dependent on lysosomal localization and the vacuolar H(+) -ATPase (V-ATPase) activity; however, the precise mechanism is still not well understood. Using primary mouse osteoclasts that are known to have higher lysosomal pH due to R740S mutation in the V-ATPase a3 subunit, we investigated the role of lysosomal pH in mTORC1 signaling. Our results demonstrated that +/R740S cells had increased basal mTOR protein levels and mTORC1 activity compared to +/+ osteoclasts, while mTOR gene expression was decreased. Treatment with lysosomal inhibitors chloroquine and ammonium chloride, compounds known to raise lysosomal pH, significantly increased mTOR protein levels in +/+ cells, confirming the importance of lysosomal pH in mTOR signaling. These results also suggested that mTOR could be degraded in the lysosome. To test this hypothesis, we cultured osteoclasts with chloroquine or proteasomal inhibitor MG132. Both chloroquine and MG132 increased mTOR and p-mTOR protein levels in +/+ osteoclasts, suggesting that mTOR undergoes both lysosomal and proteasomal degradation. Treatment with cycloheximide, an inhibitor of new protein synthesis, confirmed that mTOR is constitutively expressed and degraded. These results show that, in osteoclasts, the lysosome plays a key role not only in mTOR activation but also in its deactivation through protein degradation, representing a novel molecular mechanism of mTOR regulation.
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Affiliation(s)
- Yingwei Hu
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.,Institute of Dental Medicine, Qilu Hospital, Shandong University, Jinan, China
| | | | - Andrew Wang
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Celeste Owen
- Centre for Modeling Human Disease, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Elena Bajenova
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Paul N Corey
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - John H Brumell
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Irina Voronov
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
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180
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D'Antona G, Tedesco L, Ruocco C, Corsetti G, Ragni M, Fossati A, Saba E, Fenaroli F, Montinaro M, Carruba MO, Valerio A, Nisoli E. A Peculiar Formula of Essential Amino Acids Prevents Rosuvastatin Myopathy in Mice. Antioxid Redox Signal 2016; 25:595-608. [PMID: 27245589 PMCID: PMC5065032 DOI: 10.1089/ars.2015.6582] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AIMS Myopathy, characterized by mitochondrial oxidative stress, occurs in ∼10% of statin-treated patients, and a major risk exists with potent statins such as rosuvastatin (Rvs). We sought to determine whether a peculiar branched-chain amino acid-enriched mixture (BCAAem), found to improve mitochondrial function and reduce oxidative stress in muscle of middle-aged mice, was able to prevent Rvs myopathy. RESULTS Dietary supplementation of BCAAem was able to prevent the structural and functional alterations of muscle induced by Rvs in young mice. Rvs-increased plasma 3-methylhistidine (a marker of muscular protein degradation) was prevented by BCAAem. This was obtained without changes of Rvs ability to reduce cholesterol and triglyceride levels in blood. Rather, BCAAem promotes de novo protein synthesis and reduces proteolysis in cultured myotubes. Morphological alterations of C2C12 cells induced by statin were counteracted by amino acids, as were the Rvs-increased atrogin-1 mRNA and protein levels. Moreover, BCAAem maintained mitochondrial mass and density and citrate synthase activity in skeletal muscle of Rvs-treated mice beside oxygen consumption and ATP levels in C2C12 cells exposed to statin. Notably, BCAAem assisted Rvs to reduce oxidative stress and to increase the anti-reactive oxygen species (ROS) defense system in skeletal muscle. Innovation and Conclusions: The complex interplay between proteostasis and antioxidant properties may underlie the mechanism by which a specific amino acid formula preserves mitochondrial efficiency and muscle health in Rvs-treated mice. Strategies aimed at promoting protein balance and controlling mitochondrial ROS level may be used as therapeutics for the treatment of muscular diseases involving mitochondrial dysfunction, such as statin myopathy. Antioxid. Redox Signal. 25, 595-608.
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Affiliation(s)
- Giuseppe D'Antona
- 1 Department of Public Health, Experimental and Forensic Medicine, Pavia University , Pavia, Italy
| | - Laura Tedesco
- 2 Department of Medical Biotechnology and Translational Medicine, Center for Study and Research on Obesity, Milan University , Milan, Italy
| | - Chiara Ruocco
- 2 Department of Medical Biotechnology and Translational Medicine, Center for Study and Research on Obesity, Milan University , Milan, Italy
| | - Giovanni Corsetti
- 3 Department of Clinical and Experimental Sciences, Brescia University , Brescia, Italy
| | - Maurizio Ragni
- 2 Department of Medical Biotechnology and Translational Medicine, Center for Study and Research on Obesity, Milan University , Milan, Italy
| | - Andrea Fossati
- 2 Department of Medical Biotechnology and Translational Medicine, Center for Study and Research on Obesity, Milan University , Milan, Italy
| | - Elisa Saba
- 4 Department of Molecular and Translational Medicine, Brescia University , Brescia, Italy
| | - Francesca Fenaroli
- 4 Department of Molecular and Translational Medicine, Brescia University , Brescia, Italy
| | - Mery Montinaro
- 4 Department of Molecular and Translational Medicine, Brescia University , Brescia, Italy
| | - Michele O Carruba
- 2 Department of Medical Biotechnology and Translational Medicine, Center for Study and Research on Obesity, Milan University , Milan, Italy
| | - Alessandra Valerio
- 4 Department of Molecular and Translational Medicine, Brescia University , Brescia, Italy
| | - Enzo Nisoli
- 2 Department of Medical Biotechnology and Translational Medicine, Center for Study and Research on Obesity, Milan University , Milan, Italy
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181
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Abstract
The lysosome has long been viewed as the recycling center of the cell. However, recent discoveries have challenged this simple view and have established a central role of the lysosome in nutrient-dependent signal transduction. The degradative role of the lysosome and its newly discovered signaling functions are not in conflict but rather cooperate extensively to mediate fundamental cellular activities such as nutrient sensing, metabolic adaptation, and quality control of proteins and organelles. Moreover, lysosome-based signaling and degradation are subject to reciprocal regulation. Transcriptional programs of increasing complexity control the biogenesis, composition, and abundance of lysosomes and fine-tune their activity to match the evolving needs of the cell. Alterations in these essential activities are, not surprisingly, central to the pathophysiology of an ever-expanding spectrum of conditions, including storage disorders, neurodegenerative diseases, and cancer. Thus, unraveling the functions of this fascinating organelle will contribute to our understanding of the fundamental logic of metabolic organization and will point to novel therapeutic avenues in several human diseases.
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Affiliation(s)
- Rushika M Perera
- Department of Anatomy and Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94143;
| | - Roberto Zoncu
- Department of Molecular and Cellular Biology and Paul F. Glenn Center for Aging Research, University of California, Berkeley, California 94720;
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182
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Catabolic pathways regulated by mTORC1 are pivotal for survival and growth of cancer cells expressing mutant Ras. Oncotarget 2016; 6:40405-17. [PMID: 26575954 PMCID: PMC4747341 DOI: 10.18632/oncotarget.6334] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 11/10/2015] [Indexed: 12/13/2022] Open
Abstract
Oncogenic Ras stimulates macropinocytosis, a clathrin-independent endocytosis that increases the uptake of extracellular fluid. However, the functional significance of and regulatory mechanisms driving macropinocytosis in cancer cells remain largely unknown. Here, we show that extracellular macromolecules, such as albumin, internalized by Ras-expressing cells can support growth and survival under the nutrient-deprived conditions like those found in tumors. Moreover, we demonstrate that autophagy, a lysosome-mediated catabolic pathway, is required for the uptake and degradation of macropinocytic vesicles. Intracellular metabolites derived from macropinocytosis and autophagy directly influence the activity and localization of mTOR, which is ultimately responsible for the restoration of cell growth. Surprisingly, suppression of mTORC1, which typically triggers anabolic processes, facilitates macropinocytosis and thus supports cell growth and survival under the nutrient-deprived conditions. In a mouse xenograft model of pancreatic ductal adenocarcinoma, concomitant inhibition of macropinocytosis/autophagy and mTOR activity resulted in antitumor effects. These data suggest that novel anti-cancer strategies interrupting these metabolic processes and related signaling molecules may represent promising therapeutic avenues.
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183
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Wan ZY, Tian JS, Tan HWS, Chow AL, Sim AYL, Ban KHK, Long YC. Mechanistic target of rapamycin complex 1 is an essential mediator of metabolic and mitogenic effects of fibroblast growth factor 19 in hepatoma cells. Hepatology 2016; 64:1289-301. [PMID: 27178107 DOI: 10.1002/hep.28639] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/27/2016] [Indexed: 12/24/2022]
Abstract
UNLABELLED Fibroblast growth factor 19 (FGF19) is an important postprandial enterokine which regulates liver metabolism and hepatocyte proliferation. However, the precise mechanism by which FGF19 regulates these cellular effects is poorly understood. Given that mechanistic target of rapamycin complex 1 (mTORC1) regulates numerous postprandial adaptations, we investigated the potential role of mTORC1 in FGF19 action. We found that FGF19 activated mTORC1 in HepG2 and HuH7 human hepatoma cells, differentiated 3T3-L1 adipocytes and mouse liver. FGF19 activates the mTORC1-p70S6K and extracellular signal-regulated kinase (Erk)-p90RSK pathways independently to regulate S6 in an additive manner in hepatoma cells, but it uses mTORC1 as the primary pathway to regulate S6 in 3T3-L1 adipocytes. Thus, mTORC1 is a novel mediator of FGF19 signaling, which can act in parallel with Erk or function as the primary pathway to regulate S6. The FGF19-induced mTORC1 pathway requires amino acids for efficient signaling; thus, involvement of mTORC1 confers amino acid sensitivity to FGF19 signaling. Although Akt and Erk are known to activate mTORC1, we found that FGF19 signals to mTORC1 through a third recently identified mTORC1 regulator, Ras-like (Ral) protein. Pharmacological or genetic inhibition of RalA or RalB abolished FGF19-induced mTORC1 activation, demonstrating that Ral proteins are required for FGF19 to activate mTORC1. FGF19 induced metabolic gene expression, fatty acid oxidation, cell growth, and proliferation in HepG2 cells; and these effects were abolished by mTORC1 inhibition, demonstrating an essential role of mTORC1 in FGF19 action. CONCLUSION mTORC1 is a novel and essential mediator of FGF19 action on metabolic and mitogenic programs; thus, the involvement of mTORC1 in FGF19 signaling is an important factor to consider when targeting the pathway for cancer or diabetes therapy. (Hepatology 2016;64:1289-1301).
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Affiliation(s)
- Zhi Yi Wan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Johann Shane Tian
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hayden Weng Siong Tan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ai Lee Chow
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Arthur Yi Loong Sim
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Kenneth Hon Kim Ban
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Institute of Molecular and Cell Biology, A*STAR, Singapore
| | - Yun Chau Long
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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184
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Xia J, Wang R, Zhang T, Ding J. Structural insight into the arginine-binding specificity of CASTOR1 in amino acid-dependent mTORC1 signaling. Cell Discov 2016; 2:16035. [PMID: 27648300 PMCID: PMC5020642 DOI: 10.1038/celldisc.2016.35] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 08/30/2016] [Indexed: 12/25/2022] Open
Abstract
The mechanistic Target Of Rapamycin Complex 1 (mTORC1) is central to the cellular response to changes in nutrient signals such as amino acids. CASTOR1 is shown to be an arginine sensor, which plays an important role in the activation of the mTORC1 pathway. In the deficiency of arginine, CASTOR1 interacts with GATOR2, which together with GATOR1 and Rag GTPases controls the relocalization of mTORC1 to lysosomes. The binding of arginine to CASTOR1 disrupts its association with GATOR2 and hence activates the mTORC1 signaling. Here, we report the crystal structure of CASTOR1 in complex with arginine at 2.5 Å resolution. CASTOR1 comprises of four tandem ACT domains with an architecture resembling the C-terminal allosteric domains of aspartate kinases. ACT1 and ACT3 adopt the typical βαββαβ topology and function in dimerization via the conserved residues from helices α1 of ACT1 and α5 of ACT3; whereas ACT 2 and ACT4, both comprising of two non-sequential regions, assume the unusual ββαββα topology and contribute an arginine-binding pocket at the interface. The bound arginine makes a number of hydrogen-bonding interactions and extensive hydrophobic contacts with the surrounding residues of the binding pocket. The functional roles of the key residues are validated by mutagenesis and biochemical assays. Our structural and functional data together reveal the molecular basis for the arginine-binding specificity of CASTOR1 in the arginine-dependent activation of the mTORC1 signaling.
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Affiliation(s)
- Jing Xia
- School of Life Sciences, Shanghai University , Shanghai, China
| | - Rong Wang
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Tianlong Zhang
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Jianping Ding
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China; Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, China
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185
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Lim CY, Zoncu R. The lysosome as a command-and-control center for cellular metabolism. J Cell Biol 2016; 214:653-64. [PMID: 27621362 PMCID: PMC5021098 DOI: 10.1083/jcb.201607005] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/22/2016] [Indexed: 12/25/2022] Open
Abstract
Lysosomes are membrane-bound organelles found in every eukaryotic cell. They are widely known as terminal catabolic stations that rid cells of waste products and scavenge metabolic building blocks that sustain essential biosynthetic reactions during starvation. In recent years, this classical view has been dramatically expanded by the discovery of new roles of the lysosome in nutrient sensing, transcriptional regulation, and metabolic homeostasis. These discoveries have elevated the lysosome to a decision-making center involved in the control of cellular growth and survival. Here we review these recently discovered properties of the lysosome, with a focus on how lysosomal signaling pathways respond to external and internal cues and how they ultimately enable metabolic homeostasis and cellular adaptation.
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Affiliation(s)
- Chun-Yan Lim
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720 The Paul F. Glenn Center for Aging Research at the University of California, Berkeley, Berkeley, CA 94720
| | - Roberto Zoncu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720 The Paul F. Glenn Center for Aging Research at the University of California, Berkeley, Berkeley, CA 94720
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186
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Fei HR, Tian H, Zhou XL, Yang MF, Sun BL, Yang XY, Jiao P, Wang FZ. Inhibition of autophagy enhances effects of PF-04691502 on apoptosis and DNA damage of lung cancer cells. Int J Biochem Cell Biol 2016; 78:52-62. [DOI: 10.1016/j.biocel.2016.06.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 06/21/2016] [Accepted: 06/30/2016] [Indexed: 10/21/2022]
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187
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Kim ES, Samanta A, Cheng HS, Ding Z, Han W, Toschi L, Chang YT. Effect of oncogene activating mutations and kinase inhibitors on amino acid metabolism of human isogenic breast cancer cells. MOLECULAR BIOSYSTEMS 2016; 11:3378-86. [PMID: 26469267 DOI: 10.1039/c5mb00525f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We investigated the changes in amino acid (AA) metabolism induced in MCF10A, a human mammary epithelial cell line, by the sequential knock-in of K-Ras and PI3K mutant oncogenes. Differentially regulated genes associated to AA pathways were identified on comparing gene expression patterns in the isogenic cell lines. Additionally, we monitored the changes in the levels of AAs and transcripts in the cell lines treated with kinase inhibitors (REGO: a multi-kinase inhibitor, PI3K-i: a PI3K inhibitor, and MEK-i: a MEK inhibitor). In total, 19 AAs and 58 AA-associated transcripts were found to be differentially regulated by oncogene knock-in and by drug treatment. In particular, the multi-kinase and MEK inhibitor affected pathways in K-Ras mutant cells, whereas the PI3K inhibitor showed a major impact in the K-Ras/PI3K double mutant cells. These findings may indicate the dependency of AA metabolism on the oncogene mutation pattern in human cancer. Thus, future therapy might include combinations of kinase inhibitors and drug targeting enzymes of AA pathways.
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Affiliation(s)
- Eung-Sam Kim
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, #02-02 Helios Building, 138667, Singapore and Department of Biological Sciences, Chonnam National University, Gwangju, Korea
| | - Animesh Samanta
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, #02-02 Helios Building, 138667, Singapore
| | - Hui Shan Cheng
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, #02-02 Helios Building, 138667, Singapore
| | - Zhaobing Ding
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, #02-02 Helios Building, 138667, Singapore
| | - Weiping Han
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, #02-02 Helios Building, 138667, Singapore
| | - Luisella Toschi
- Global Drug Discovery, Therapeutic Research Group Oncology/Gynecological Therapies, Tumor Metabolism, Bayer Pharma AG, Berlin, Germany
| | - Young Tae Chang
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, #02-02 Helios Building, 138667, Singapore and Department of Chemistry & MedChem Program of Life Sciences Institute, National University of Singapore, 117543, Singapore.
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188
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Hasegawa T, Muraoka Y, Ikeda HO, Tsuruyama T, Kondo M, Terasaki H, Kakizuka A, Yoshimura N. Neuoroprotective efficacies by KUS121, a VCP modulator, on animal models of retinal degeneration. Sci Rep 2016; 6:31184. [PMID: 27503804 PMCID: PMC4977562 DOI: 10.1038/srep31184] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/14/2016] [Indexed: 12/17/2022] Open
Abstract
Retinitis pigmentosa (RP) is one of the leading causes of adult blindness and has no established therapy. We have shown that valosin-containing protein (VCP) modulators, Kyoto University Substances (KUSs), ameliorated abnormally low ATP levels by inhibiting the ATPase of VCP, thereby protected several types of cells, including retinal neurons, from cell death-inducing insults. In this study, we found that KUS121, one of the VCP modulators, effectively protects photoreceptors both morphologically and functionally, in two animal models of retinal degeneration, rd12 mice and RP rabbits with a rhodopsin (Pro347Leu) mutation. In rd12 mice, KUS121 suppressed the loss of photoreceptors, not only rods but also cones, as well as the visual function deterioration. Significant protective effects existed even when the medication was started in later stages of the disease. In RP rabbits, KUS121 suppressed thinning of the outer nuclear layer and maintained visual function. In the retinas treated with KUS121, suppression of endoplasmic reticulum stress, activation of mammalian target of rapamycin and suppression of disease-associated apoptosis were evident. The ability of KUS121 to protect photoreceptors, especially cones, even in later stages of the disease may contribute to the preservation of central vision in RP patients, which is important for quality of vision.
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Affiliation(s)
- Tomoko Hasegawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, 606-8501, Japan
| | - Yuki Muraoka
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, 606-8501, Japan
| | - Hanako Ohashi Ikeda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, 606-8501, Japan.,Department of Experimental Therapeutics, Institute for Advancement of Clinical and Translational Science, Kyoto university Hospital, Kyoto, 606-8501, Japan
| | - Tatsuaki Tsuruyama
- Center for Anatomical Studies, Kyoto University Graduate School of Medicine, Kyoto, 606-8501, Japan
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Tsu, 514-8607, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 464-8601, Japan
| | - Akira Kakizuka
- Laboratory of Functional Biology, Kyoto University Graduate School of Biostudies &Solution Oriented Research for Science and Technology, Kyoto, 606-8501, Japan
| | - Nagahisa Yoshimura
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, 606-8501, Japan
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189
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Ha J, Kim J. Novel pharmacological modulators of autophagy: an updated patent review (2012-2015). Expert Opin Ther Pat 2016; 26:1273-1289. [PMID: 27476990 DOI: 10.1080/13543776.2016.1217996] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Autophagy is a lysosome-dependent degradation pathway that maintains cellular homeostasis in response to a variety of cellular stresses. Accumulating reports based on animal models have indicated the importance of this catabolic program in many human pathophysiological conditions, including diabetes, neurodegenerative diseases, aging, and cancers. Therefore, autophagy has been highlighted as a novel therapeutic target with a wide range of beneficial effects on human diseases. Here, we review the recent advances of our knowledge toward autophagy, as well as the efforts for developing autophagy modulators. Areas covered: The relevant patents (published at 2012-2015) and the research literature claiming the pharmacological modulation of autophagy are reviewed. Also, their molecular mechanisms and potential therapeutic utilities are discussed. Expert opinion: Considering the molecular machinery involved in autophagy induction, the targeting of autophagy-specific protein is very important to design the therapeutic interventions for specifically treating a variety of autophagy-associated disorders. Many patents and the research literature described in this review have shown promising applications of the relevant autophagy modulators for cancer or neurodegeneration treatments, a few of which are already being considered for clinical evaluation. However, most patents have claimed the modulators of autophagy with little information regarding their mechanisms of action. To design highly potent therapeutics, further work, such as developing compounds that specifically target the autophagy-specific machinery, are required.
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Affiliation(s)
- Joohun Ha
- a Department of Biochemistry and Molecular Biology , School of Medicine, Kyung Hee University , Seoul , Korea
| | - Joungmok Kim
- b Department of Oral Biochemistry and Molecular Biology , School of Dentistry, Kyung Hee University , Seoul , Korea
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190
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Regulation of autophagy by mitochondrial phospholipids in health and diseases. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:114-129. [PMID: 27502688 DOI: 10.1016/j.bbalip.2016.08.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/28/2016] [Accepted: 08/04/2016] [Indexed: 12/16/2022]
Abstract
Autophagy is an evolutionarily conserved mechanism that maintains nutrient homeostasis by degrading protein aggregates and damaged organelles. Autophagy is reduced in aging, which is implicated in the pathogenesis of aging-related diseases, including cancers, obesity, type 2 diabetes, cardiovascular diseases, and neurodegenerative diseases. Mitochondria-derived phospholipids cardiolipin, phosphatidylethanolamine, and phosphatidylglycerol are critical throughout the autophagic process, from initiation and phagophore formation to elongation and fusion with endolysosomal vesicles. Cardiolipin is also required for mitochondrial fusion and fission, an important step in isolating dysfunctional mitochondria for mitophagy. Furthermore, genetic screen in yeast has identified a surprising role for cardiolipin in regulating lysosomal function. Phosphatidylethanolamine plays a pivotal role in supporting the autophagic process, including autophagosome elongation as part of lipidated Atg8/LC3. An emerging role for phosphatidylglycerol in AMPK and mTORC1 signaling as well as mitochondrial fission may provide the first glimpse into the function of phosphatidylglycerol apart from being a precursor for cardiolipin. This review examines the effects of manipulating phospholipids on autophagy and mitophagy in health and diseases, as well as current limitations in the field. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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191
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Mitchell WK, Wilkinson DJ, Phillips BE, Lund JN, Smith K, Atherton PJ. Human Skeletal Muscle Protein Metabolism Responses to Amino Acid Nutrition. Adv Nutr 2016; 7:828S-38S. [PMID: 27422520 PMCID: PMC4942869 DOI: 10.3945/an.115.011650] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Healthy individuals maintain remarkably constant skeletal muscle mass across much of adult life, suggesting the existence of robust homeostatic mechanisms. Muscle exists in dynamic equilibrium whereby the influx of amino acids (AAs) and the resulting increases in muscle protein synthesis (MPS) associated with the intake of dietary proteins cancel out the efflux of AAs from muscle protein breakdown that occurs between meals. Dysregulated proteostasis is evident with aging, especially beyond the sixth decade of life. Women and men aged 75 y lose muscle mass at a rate of ∼0.7% and 1%/y, respectively (sarcopenia), and lose strength 2- to 5-fold faster (dynapenia) as muscle "quality" decreases. Factors contributing to the disruption of an otherwise robust proteostatic system represent targets for potential therapies that promote healthy aging. Understanding age-related impairments in anabolic responses to AAs and identifying strategies to mitigate these factors constitute major areas of interest. Numerous studies have aimed to identify 1) the influence of distinct protein sources on absorption kinetics and muscle anabolism, 2) the latency and time course of MPS responses to protein/AAs, 3) the impacts of protein/AA intake on muscle microvascular recruitment, and 4) the role of certain AAs (e.g., leucine) as signaling molecules, which are able to trigger anabolic pathways in tissues. This review aims to discuss these 4 issues listed, to provide historical and modern perspectives of AAs as modulators of human skeletal muscle protein metabolism, to describe how advances in stable isotope/mass spectrometric approaches and instrumentation have underpinned these advances, and to highlight relevant differences between young adults and older individuals. Whenever possible, observations are based on human studies, with additional consideration of relevant nonhuman studies.
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Affiliation(s)
- W Kyle Mitchell
- Department of Surgery, Royal Derby Hospital, Derby, United Kingdom; and
| | - Daniel J Wilkinson
- Medical Research Council, Arthritis Research United Kingdom, Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, Royal Derby Hospital, University of Nottingham, Derby, United Kingdom
| | - Bethan E Phillips
- Medical Research Council, Arthritis Research United Kingdom, Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, Royal Derby Hospital, University of Nottingham, Derby, United Kingdom
| | - Jonathan N Lund
- Department of Surgery, Royal Derby Hospital, Derby, United Kingdom; and,,Medical Research Council, Arthritis Research United Kingdom, Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, Royal Derby Hospital, University of Nottingham, Derby, United Kingdom
| | - Kenneth Smith
- Medical Research Council, Arthritis Research United Kingdom, Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, Royal Derby Hospital, University of Nottingham, Derby, United Kingdom
| | - Philip J Atherton
- Medical Research Council, Arthritis Research United Kingdom, Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, Royal Derby Hospital, University of Nottingham, Derby, United Kingdom
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192
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Chaudhary A, Leite M, Kulasekara BR, Altura MA, Ogahara C, Weiss E, Fu W, Blanc MP, O'Keeffe M, Terhorst C, Akey JM, Miller SI. Human Diversity in a Cell Surface Receptor that Inhibits Autophagy. Curr Biol 2016; 26:1791-801. [PMID: 27345162 DOI: 10.1016/j.cub.2016.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 04/27/2016] [Accepted: 05/03/2016] [Indexed: 02/01/2023]
Abstract
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.
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Affiliation(s)
- Anu Chaudhary
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Mara Leite
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | | | - Melissa A Altura
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Cassandra Ogahara
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Eli Weiss
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Wenqing Fu
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Marie-Pierre Blanc
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Michael O'Keeffe
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Cox Terhorst
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Joshua M Akey
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Samuel I Miller
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Department of Immunology, University of Washington, Seattle, WA 98195, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA.
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193
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Lassen KG, McKenzie CI, Mari M, Murano T, Begun J, Baxt LA, Goel G, Villablanca EJ, Kuo SY, Huang H, Macia L, Bhan AK, Batten M, Daly MJ, Reggiori F, Mackay CR, Xavier RJ. Genetic Coding Variant in GPR65 Alters Lysosomal pH and Links Lysosomal Dysfunction with Colitis Risk. Immunity 2016; 44:1392-405. [PMID: 27287411 DOI: 10.1016/j.immuni.2016.05.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/19/2016] [Accepted: 03/21/2016] [Indexed: 12/28/2022]
Abstract
Although numerous polymorphisms have been associated with inflammatory bowel disease (IBD), identifying the function of these genetic factors has proved challenging. Here we identified a role for nine genes in IBD susceptibility loci in antibacterial autophagy and characterized a role for one of these genes, GPR65, in maintaining lysosome function. Mice lacking Gpr65, a proton-sensing G protein-coupled receptor, showed increased susceptibly to bacteria-induced colitis. Epithelial cells and macrophages lacking GPR65 exhibited impaired clearance of intracellular bacteria and accumulation of aberrant lysosomes. Similarly, IBD patient cells and epithelial cells expressing an IBD-associated missense variant, GPR65 I231L, displayed aberrant lysosomal pH resulting in lysosomal dysfunction, impaired bacterial restriction, and altered lipid droplet formation. The GPR65 I231L polymorphism was sufficient to confer decreased GPR65 signaling. Collectively, these data establish a role for GPR65 in IBD susceptibility and identify lysosomal dysfunction as a potentially causative element in IBD pathogenesis with effects on cellular homeostasis and defense.
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Affiliation(s)
- Kara G Lassen
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA.
| | - Craig I McKenzie
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Muriel Mari
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, 3713 AV Groningen, the Netherlands; Department of Cell Biology, University Medical Center Utrecht, 3564 CX Utrecht, the Netherlands
| | - Tatsuro Murano
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jakob Begun
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Mater Research Institute and School of Medicine, University of Queensland, Brisbane, QLD 4101, Australia
| | - Leigh A Baxt
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Gautam Goel
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Eduardo J Villablanca
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Szu-Yu Kuo
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Hailiang Huang
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Laurence Macia
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Atul K Bhan
- Pathology Department, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Marcel Batten
- Garvan Institute of Medical Research and St. Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - Mark J Daly
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Fulvio Reggiori
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, 3713 AV Groningen, the Netherlands; Department of Cell Biology, University Medical Center Utrecht, 3564 CX Utrecht, the Netherlands
| | - Charles R Mackay
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Ramnik J Xavier
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Boston, MA 02114, USA.
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194
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Kishikawa T, Otsuka M, Tan PS, Ohno M, Sun X, Yoshikawa T, Shibata C, Takata A, Kojima K, Takehana K, Ohishi M, Ota S, Noyama T, Kondo Y, Sato M, Soga T, Hoshida Y, Koike K. Decreased miR122 in hepatocellular carcinoma leads to chemoresistance with increased arginine. Oncotarget 2016; 6:8339-52. [PMID: 25826076 PMCID: PMC4480756 DOI: 10.18632/oncotarget.3234] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 01/28/2015] [Indexed: 12/12/2022] Open
Abstract
Reduced expression of microRNA122 (miR122), a liver-specific microRNA, is
frequent in hepatocellular carcinoma (HCC). However, its biological
significances remain poorly understood. Because deregulated amino acid levels in
cancers can affect their biological behavior, we determined the amino acid
levels in miR122-silenced mouse liver tissues, in which intracellular arginine
levels were significantly increased. The increased intracellular arginine levels
were through upregulation of the solute carrier family 7 (SLC7A1), a transporter
of arginine and a direct target of miR122. Arginine is the substrate for nitric
oxide (NO) synthetase, and intracellular NO levels were increased in
miR122-silenced HCC cells, with increased resistance to sorafenib, a multikinase
inhibitor. Conversely, maintenance of the miR122-silenced HCC cells in
arginine-depleted culture media, as well as overexpression of miR122 in
miR122-low-expressing HCC cells, reversed these effects and rendered the cells
more sensitive to sorafenib. Using a reporter knock-in construct, chemical
compounds were screened, and Wee1 kinase inhibitor was identified as
upregulators of miR122 transcription, which increased the sensitivity of the
cells to sorafenib. These results provide an insight into sorafenib resistance
in miR122-low HCC, and suggest that arginine depletion or a combination of
sorafenib with the identified compound may provide promising approaches to
managing this HCC subset.
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Affiliation(s)
- Takahiro Kishikawa
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Motoyuki Otsuka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.,Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama 332-0012, Japan
| | - Poh Seng Tan
- Liver Cancer Program, Tisch Cancer Institute, Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, NY 10029, USA.,Division of Gastroenterology and Hepatology, University Medicine Cluster, National University Health System, 119228, Singapore
| | - Motoko Ohno
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Xiaochen Sun
- Liver Cancer Program, Tisch Cancer Institute, Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, NY 10029, USA
| | - Takeshi Yoshikawa
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Chikako Shibata
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Akemi Takata
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Kentaro Kojima
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Kenji Takehana
- Pharmacology Research Laboratory, Research Institute, Ajinomoto Pharmaceutical Co., Ltd., Kawasaki, Kanagawa 210-8681, Japan
| | - Maki Ohishi
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Sana Ota
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Tomoyuki Noyama
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yuji Kondo
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Masaya Sato
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Tomoyoshi Soga
- Pharmacology Research Laboratory, Research Institute, Ajinomoto Pharmaceutical Co., Ltd., Kawasaki, Kanagawa 210-8681, Japan
| | - Yujin Hoshida
- Liver Cancer Program, Tisch Cancer Institute, Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, NY 10029, USA
| | - Kazuhiko Koike
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
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195
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Christy B, Demaria M, Campisi J, Huang J, Jones D, Dodds SG, Williams C, Hubbard G, Livi CB, Gao X, Weintraub S, Curiel T, Sharp ZD, Hasty P. p53 and rapamycin are additive. Oncotarget 2016; 6:15802-13. [PMID: 26158292 PMCID: PMC4599238 DOI: 10.18632/oncotarget.4602] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/14/2015] [Indexed: 12/13/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a kinase found in a complex (mTORC1) that enables macromolecular synthesis and cell growth and is implicated in cancer etiology. The rapamycin-FK506 binding protein 12 (FKBP12) complex allosterically inhibits mTORC1. In response to stress, p53 inhibits mTORC1 through a separate pathway involving cell signaling and amino acid sensing. Thus, these different mechanisms could be additive. Here we show that p53 improved the ability of rapamycin to: 1) extend mouse life span, 2) suppress ionizing radiation (IR)-induced senescence-associated secretory phenotype (SASP) and 3) increase the levels of amino acids and citric acid in mouse embryonic stem (ES) cells. This additive effect could have implications for cancer treatment since rapamycin and p53 are anti-oncogenic.
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Affiliation(s)
- Barbara Christy
- Departments of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Cancer Therapy & Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Marco Demaria
- Buck Institute for Research on Aging, Novato, CA, USA
| | | | - Jing Huang
- Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Diane Jones
- Departments of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Sherry G Dodds
- Departments of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Charnae Williams
- Departments of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Gene Hubbard
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Carolina B Livi
- Departments of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Current address: Agilent Technologies, Inc., Santa Clara, CA, USA
| | - Xiaoli Gao
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Susan Weintraub
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Tyler Curiel
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Cancer Therapy & Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Z Dave Sharp
- Departments of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Cancer Therapy & Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Paul Hasty
- Departments of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Cancer Therapy & Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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196
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Melnik BC, John SM, Carrera-Bastos P, Schmitz G. Milk: a postnatal imprinting system stabilizing FoxP3 expression and regulatory T cell differentiation. Clin Transl Allergy 2016; 6:18. [PMID: 27175277 PMCID: PMC4864898 DOI: 10.1186/s13601-016-0108-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/19/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Breastfeeding has protective effects for the development of allergies and atopy. Recent evidence underlines that consumption of unboiled farm milk in early life is a key factor preventing the development of atopic diseases. Farm milk intake has been associated with increased demethylation of FOXP3 and increased numbers of regulatory T cells (Tregs). Thus, the questions arose which components of farm milk control the differentiation and function of Tregs, critical T cell subsets that promote tolerance induction and inhibit the development of allergy and autoimmunity. FINDINGS Based on translational research we identified at least six major signalling pathways that could explain milk's biological role controlling stable FoxP3 expression and Treg differentiation: (1) via maintaining appropriate magnitudes of Akt-mTORC1 signalling, (2) via transfer of milk fat-derived long-chain ω-3 fatty acids, (3) via transfer of milk-derived exosomal microRNAs that apparently decrease FOXP3 promoter methylation, (4) via transfer of exosomal transforming growth factor-β, which induces SMAD2/SMAD3-dependent FoxP3 expression, (5) via milk-derived Bifidobacterium and Lactobacillus species that induce interleukin-10 (IL-10)-mediated differentiation of Tregs, and (6) via milk-derived oligosaccharides that serve as selected nutrients for the growth of bifidobacteria in the intestine of the new born infant. CONCLUSION Accumulating evidence underlines that milk is a complex signalling and epigenetic imprinting network that promotes stable FoxP3 expression and long-lasting Treg differentiation, crucial postnatal events preventing atopic and autoimmune diseases.
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Affiliation(s)
- Bodo C Melnik
- Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Sedanstrasse 115, 49090 Osnabrück, Germany
| | - Swen Malte John
- Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Sedanstrasse 115, 49090 Osnabrück, Germany
| | | | - Gerd Schmitz
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Josef-Strauss-Allee 11, 93053 Regensburg, Germany
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197
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Bertuzzi A, Conte F, Mingrone G, Papa F, Salinari S, Sinisgalli C. Insulin Signaling in Insulin Resistance States and Cancer: A Modeling Analysis. PLoS One 2016; 11:e0154415. [PMID: 27149630 PMCID: PMC4858213 DOI: 10.1371/journal.pone.0154415] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 04/12/2016] [Indexed: 01/21/2023] Open
Abstract
Insulin resistance is the common denominator of several diseases including type 2 diabetes and cancer, and investigating the mechanisms responsible for insulin signaling impairment is of primary importance. A mathematical model of the insulin signaling network (ISN) is proposed and used to investigate the dose-response curves of components of this network. Experimental data of C2C12 myoblasts with phosphatase and tensin homologue (PTEN) suppressed and data of L6 myotubes with induced insulin resistance have been analyzed by the model. We focused particularly on single and double Akt phosphorylation and pointed out insulin signaling changes related to insulin resistance. Moreover, a new characterization of the upstream signaling of the mammalian target of rapamycin complex 2 (mTORC2) is presented. As it is widely recognized that ISN proteins have a crucial role also in cell proliferation and death, the ISN model was linked to a cell population model and applied to data of a cell line of acute myeloid leukemia treated with a mammalian target of rapamycin inhibitor with antitumor activity. The analysis revealed simple relationships among the concentrations of ISN proteins and the parameters of the cell population model that characterize cell cycle progression and cell death.
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Affiliation(s)
- Alessandro Bertuzzi
- Institute of Systems Analysis and Computer Science “A. Ruberti”, CNR, 00185, Rome, Italy
| | - Federica Conte
- Institute of Systems Analysis and Computer Science “A. Ruberti”, CNR, 00185, Rome, Italy
- Department of Computer and System Science, Sapienza University of Rome, 00185, Rome, Italy
| | - Geltrude Mingrone
- Department of Internal Medicine, Catholic University School of Medicine, 00168, Rome, Italy
- * E-mail:
| | - Federico Papa
- Institute of Systems Analysis and Computer Science “A. Ruberti”, CNR, 00185, Rome, Italy
- SYSBIO - Centre of Systems Biology, Milan, Italy
| | - Serenella Salinari
- Department of Computer and System Science, Sapienza University of Rome, 00185, Rome, Italy
| | - Carmela Sinisgalli
- Institute of Systems Analysis and Computer Science “A. Ruberti”, CNR, 00185, Rome, Italy
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198
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Ivanova EA, van den Heuvel LP, Elmonem MA, De Smedt H, Missiaen L, Pastore A, Mekahli D, Bultynck G, Levtchenko EN. Altered mTOR signalling in nephropathic cystinosis. J Inherit Metab Dis 2016; 39:457-464. [PMID: 26909499 DOI: 10.1007/s10545-016-9919-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/22/2016] [Accepted: 02/02/2016] [Indexed: 11/27/2022]
Abstract
Lysosomes play a central role in regulating autophagy via activation of mammalian target of rapamycin complex 1 (mTORC1). We examined mTORC1 signalling in the lysosomal storage disease nephropathic cystinosis (MIM 219800), in which accumulation of autophagy markers has been previously demonstrated. Cystinosis is caused by mutations in the lysosomal cystine transporter cystinosin and initially affects kidney proximal tubules causing renal Fanconi syndrome, followed by a gradual development of end-stage renal disease and extrarenal complications. Using proximal tubular kidney cells obtained from healthy donors and from cystinotic patients, we demonstrate that cystinosin deficiency is associated with a perturbed mTORC1 signalling, delayed reactivation of mTORC1 after starvation and abnormal lysosomal retention of mTOR during starvation. These effects could not be reversed by treatment with cystine-depleting drug cysteamine. Altered mTORC1 signalling can contribute to the development of proximal tubular dysfunction in cystinosis and points to new possibilities in therapeutic intervention through modulation of mTORC-dependent signalling cascades.
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Affiliation(s)
- Ekaterina A Ivanova
- Department of Growth and Regeneration, KU Leuven and University Hospitals Leuven, UZ Herestraat 49, 3000, Leuven, Belgium
| | - Lambertus P van den Heuvel
- Department of Growth and Regeneration, KU Leuven and University Hospitals Leuven, UZ Herestraat 49, 3000, Leuven, Belgium
- Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mohamed A Elmonem
- Department of Growth and Regeneration, KU Leuven and University Hospitals Leuven, UZ Herestraat 49, 3000, Leuven, Belgium
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Humbert De Smedt
- Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Ludwig Missiaen
- Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Anna Pastore
- Laboratory of Proteomics and Metabolomics, Children's Hospital and Research Institute "Bambino Gesù" IRCCS, Rome, Italy
| | - Djalila Mekahli
- Department of Growth and Regeneration, KU Leuven and University Hospitals Leuven, UZ Herestraat 49, 3000, Leuven, Belgium
| | - Greet Bultynck
- Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Elena N Levtchenko
- Department of Growth and Regeneration, KU Leuven and University Hospitals Leuven, UZ Herestraat 49, 3000, Leuven, Belgium.
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199
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Patil MD, Bhaumik J, Babykutty S, Banerjee UC, Fukumura D. Arginine dependence of tumor cells: targeting a chink in cancer's armor. Oncogene 2016; 35:4957-72. [PMID: 27109103 DOI: 10.1038/onc.2016.37] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/02/2016] [Accepted: 02/02/2016] [Indexed: 12/14/2022]
Abstract
Arginine, one among the 20 most common natural amino acids, has a pivotal role in cellular physiology as it is being involved in numerous cellular metabolic and signaling pathways. Dependence on arginine is diverse for both tumor and normal cells. Because of decreased expression of argininosuccinate synthetase and/or ornithine transcarbamoylase, several types of tumor are auxotrophic for arginine. Deprivation of arginine exploits a significant vulnerability of these tumor cells and leads to their rapid demise. Hence, enzyme-mediated arginine depletion is a potential strategy for the selective destruction of tumor cells. Arginase, arginine deiminase and arginine decarboxylase are potential enzymes that may be used for arginine deprivation therapy. These arginine catabolizing enzymes not only reduce tumor growth but also make them susceptible to concomitantly administered anti-cancer therapeutics. Most of these enzymes are currently under clinical investigations and if successful will potentially be advanced as anti-cancer modalities.
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Affiliation(s)
- M D Patil
- Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical Education and Research, Punjab, India
| | - J Bhaumik
- Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical Education and Research, Punjab, India
| | - S Babykutty
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - U C Banerjee
- Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical Education and Research, Punjab, India
| | - D Fukumura
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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200
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Yang XZ, Li XX, Zhang YJ, Rodriguez-Rodriguez L, Xiang MQ, Wang HY, Zheng XFS. Rab1 in cell signaling, cancer and other diseases. Oncogene 2016; 35:5699-5704. [PMID: 27041585 PMCID: PMC5396462 DOI: 10.1038/onc.2016.81] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 02/23/2016] [Accepted: 02/26/2016] [Indexed: 12/17/2022]
Abstract
The endoplasmic reticulum (ER) and Golgi membrane system have major roles in cell signaling and regulation of the biosynthesis/transport of proteins and lipids in response to environmental cues such as amino acid and cholesterol levels. Rab1 is the founding member of the Rab small GTPase family, which is known to mediate dynamic membrane trafficking between ER and Golgi. Growing evidence indicate that Rab1 proteins have important functions beyond their classical vesicular transport functions, including nutrient sensing and signaling, cell migration and presentation of cell-surface receptors. Moreover, deregulation of RAB1 expression has been linked to a myriad of human diseases such as cancer, cardiomyopathy and Parkinson's disease. Further investigating these new physiological and pathological functions of Rab1 should provide new opportunities for better understanding of the disease processes and may lead to more effective therapeutic interventions.
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Affiliation(s)
- X-Z Yang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - X-X Li
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Y-J Zhang
- Rutgers Cancer Institute of New Jersey, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.,Oncology Department, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - L Rodriguez-Rodriguez
- Rutgers Cancer Institute of New Jersey, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.,Department of Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - M-Q Xiang
- Center for Advanced Biotechnology and Medicine, and Department of Pediatrics, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - H-Y Wang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China.,Rutgers Cancer Institute of New Jersey, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.,Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - X F S Zheng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China.,Rutgers Cancer Institute of New Jersey, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.,Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
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