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Ullah MI, Alameen AAM, Al-Oanzi ZH, Eltayeb LB, Atif M, Munir MU, Ejaz H. Biological Role of Zinc in Liver Cirrhosis: An Updated Review. Biomedicines 2023; 11:biomedicines11041094. [PMID: 37189711 DOI: 10.3390/biomedicines11041094] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/01/2023] [Accepted: 04/02/2023] [Indexed: 05/17/2023] Open
Abstract
Liver cirrhosis is a complication usually due to the consequence of persistent chronic liver disease. It is associated with different mechanisms, including hypoalbuminemia, impaired amino acid turnover, and micronutrient deficiencies. Consequently, cirrhotic patients can develop progressive complications like ascites, hepatic encephalopathy, and hepatocellular carcinoma. The liver is a vital organ that regulates the different metabolic pathways and transportation of trace elements. Zn is an indispensable micronutrient trace element involved in its crucial functions in cellular metabolic activity. Zn mediates its action by binding to a wide range of proteins; therefore, it imparts numerous biological effects, including cellular division, differentiation, and growth. It is also involved in critical processes for the biosynthesis of structural proteins and regulation of transcription factors and acts as a co-factor for the various enzymatic processes. As the liver is a significant regulator of Zn metabolism, its abnormalities lead to Zn deficiency, which has consequences on cellular, endocrine, immune, sensory, and skin dysfunctions. Conversely, Zn deficiency may modify the functions of hepatocytes and immune responses (acute phase protein production) in inflammatory liver diseases. This review has concisely stated the evolving indication of the critical role of Zn in biological processes and complications associated with liver cirrhosis pathogenesis due to Zn deficiency.
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Affiliation(s)
- Muhammad Ikram Ullah
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Aljouf, Saudi Arabia
| | - Ayman Ali Mohammed Alameen
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Aljouf, Saudi Arabia
| | - Ziad H Al-Oanzi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Aljouf, Saudi Arabia
| | - Lienda Bashier Eltayeb
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Prince Sattam Bin Abdul Aziz University, Al-Kharj 11942, Riyadh, Saudi Arabia
| | - Muhammad Atif
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Aljouf, Saudi Arabia
| | - Muhammad Usman Munir
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka 72388, Aljouf, Saudi Arabia
| | - Hasan Ejaz
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Aljouf, Saudi Arabia
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Metabolic reprogramming of glutamine involved in tumorigenesis, multidrug resistance and tumor immunity. Eur J Pharmacol 2023; 940:175323. [PMID: 36535492 DOI: 10.1016/j.ejphar.2022.175323] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/03/2022] [Accepted: 10/11/2022] [Indexed: 12/23/2022]
Abstract
Glutamine, as the most abundant amino acid in the body, participates in the biological synthesis of nucleotides and other non-essential amino acids in the process of cell metabolism. Recent studies showed that glutamine metabolic reprogramming is an important signal during cancer development and progression. This metabolic signature in cancer cells can promote the development of cancer by activating multiple signaling pathways and oncogenes. It can also be involved in tumor immune regulation and promote the development of drug resistance to tumors. In this review, we mainly summarize the role of glutamine metabolic reprogramming in tumors, including the regulation of multiple signaling pathways. We further discussed the promising tumor treatment strategy by targeting glutamine metabolism alone or in combination with chemotherapeutics.
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Hou YC, Wu JM, Chen KY, Wu MH, Yang PJ, Lee PC, Chen PD, Yeh SL, Lin MT. Glutamine and leucine administration attenuates muscle atrophy in sepsis. Life Sci 2023; 314:121327. [PMID: 36584912 DOI: 10.1016/j.lfs.2022.121327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/02/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022]
Abstract
AIMS This study investigated whether l-glutamine (Gln) and/or l-leucine (Leu) administration could attenuate muscle atrophy in a mouse model of cecal ligation and puncture (CLP)-induced sepsis. MATERIALS AND METHODS Septic mice were given a daily intraperitoneal injection of Gln, Leu, or Gln plus Leu, and mice were sacrificed on either day 1 or 4 after CLP. Blood and muscles were collected for analysis of amino acid contents and markers related to protein degradation, muscle regeneration, and protein synthesis. KEY FINDINGS Leu treatment alone increased both muscle mass and total muscle protein content on day 4 after CLP. Gln administration reduced muscular Gln contents on day 1 and enhanced plasma Gln levels on day 4. Higher plasma branched-chain amino acid (BCAA) abundances and lower muscular BCAA levels were observed in Leu-treated mice on day 4. Gln and Leu individually suppressed muscle expressions of the E3 ubiquitin ligase genes, Trim63 and Fbxo32, on day 4 after CLP. As to muscle expressions of myogenic genes, both Gln and Leu upregulated Myog expression on day 1, but Leu alone enhanced Myf5 gene expression, whereas Gln plus Leu increased MyoD and Myog expression levels on day 4. Akt/mammalian target of rapamycin (mTOR) signaling was only activated by Gln and Leu when individually administered. SIGNIFICANCE Gln and/or Leu administration reduces sepsis-induced muscle degradation and promotes myogenic gene expressions. Leu treatment alone had more-pronounced effects on maintaining muscle mass during sepsis. A combination of Gln and Leu failed to show synergistic effects on alleviating sepsis-induced muscle atrophy.
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Affiliation(s)
- Yu-Chen Hou
- Master Program in Food Safety, College of Nutrition, Taipei Medical University, Taipei, Taiwan; School of Food Safety, College of Nutrition, Taipei Medical University, Taipei, Taiwan; Nutrition Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Jin-Ming Wu
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Kuen-Yuan Chen
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ming-Hsun Wu
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Po-Jen Yang
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Po-Chu Lee
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Po-Da Chen
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Sung-Ling Yeh
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ming-Tsan Lin
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan.
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Rozance PJ, Boehmer BH, Chang EI, Wesolowski SR, Brown LD. Chronic Fetal Leucine Infusion Increases Rate of Leucine Oxidation but Not of Protein Synthesis in Late Gestation Fetal Sheep. J Nutr 2023; 153:493-504. [PMID: 36894241 PMCID: PMC10196590 DOI: 10.1016/j.tjnut.2022.12.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/19/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Leucine increases protein synthesis rates in postnatal animals and adults. Whether supplemental leucine has similar effects in the fetus has not been determined. OBJECTIVE To determine the effect of a chronic leucine infusion on whole-body leucine oxidation and protein metabolic rates, muscle mass, and regulators of muscle protein synthesis in late gestation fetal sheep. METHODS Catheterized fetal sheep at ∼126 d of gestation (term = 147 d) received infusions of saline (CON, n = 11) or leucine (LEU; n = 9) adjusted to increase fetal plasma leucine concentrations by 50%-100% for 9 d. Umbilical substrate net uptake rates and protein metabolic rates were determined using a 1-13C leucine tracer. Myofiber myosin heavy chain (MHC) type and area, expression of amino acid transporters, and abundance of protein synthesis regulators were measured in fetal skeletal muscle. Groups were compared using unpaired t tests. RESULTS Plasma leucine concentrations were 75% higher in LEU fetuses compared with CON by the end of the infusion period (P < 0.0001). Umbilical blood flow and uptake rates of most amino acids, lactate, and oxygen were similar between groups. Fetal whole-body leucine oxidation was 90% higher in LEU (P < 0.0005) but protein synthesis and breakdown rates were similar. Fetal and muscle weights and myofiber areas were similar between groups, however, there were fewer MHC type IIa fibers (P < 0.05), greater mRNA expression levels of amino acid transporters (P < 0.01), and a higher abundance of signaling proteins that regulate protein synthesis (P < 0.05) in muscle from LEU fetuses. CONCLUSIONS A direct leucine infusion for 9 d in late gestation fetal sheep does not increase protein synthesis rates but results in higher leucine oxidation rates and fewer glycolytic myofibers. Increasing leucine concentrations in the fetus stimulates its own oxidation but also increases amino acid transporter expression and primes protein synthetic pathways in skeletal muscle.
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Affiliation(s)
- Paul J Rozance
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Brit H Boehmer
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Eileen I Chang
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Stephanie R Wesolowski
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Laura D Brown
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA.
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Huynh C, Ryu J, Lee J, Inoki A, Inoki K. Nutrient-sensing mTORC1 and AMPK pathways in chronic kidney diseases. Nat Rev Nephrol 2023; 19:102-122. [PMID: 36434160 DOI: 10.1038/s41581-022-00648-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2022] [Indexed: 11/27/2022]
Abstract
Nutrients such as glucose, amino acids and lipids are fundamental sources for the maintenance of essential cellular processes and homeostasis in all organisms. The nutrient-sensing kinases mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) are expressed in many cell types and have key roles in the control of cell growth, proliferation, differentiation, metabolism and survival, ultimately contributing to the physiological development and functions of various organs, including the kidney. Dysregulation of these kinases leads to many human health problems, including cancer, neurodegenerative diseases, metabolic disorders and kidney diseases. In the kidney, physiological levels of mTOR and AMPK activity are required to support kidney cell growth and differentiation and to maintain kidney cell integrity and normal nephron function, including transport of electrolytes, water and glucose. mTOR forms two functional multi-protein kinase complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Hyperactivation of mTORC1 leads to podocyte and tubular cell dysfunction and vulnerability to injury, thereby contributing to the development of chronic kidney diseases, including diabetic kidney disease, obesity-related kidney disease and polycystic kidney disease. Emerging evidence suggests that targeting mTOR and/or AMPK could be an effective therapeutic approach to controlling or preventing these diseases.
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Affiliation(s)
- Christopher Huynh
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jaewhee Ryu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Jooho Lee
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Ayaka Inoki
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
- Department of Internal Medicine, Division of Nephrology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ken Inoki
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
- Department of Internal Medicine, Division of Nephrology, University of Michigan Medical School, Ann Arbor, MI, USA.
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Hirose S, Waku T, Tani M, Masuda H, Endo K, Ashitani S, Aketa I, Kitano H, Nakada S, Wada A, Hatanaka A, Osawa T, Soga T, Kobayashi A. NRF3 activates mTORC1 arginine-dependently for cancer cell viability. iScience 2023; 26:106045. [PMID: 36818298 PMCID: PMC9932127 DOI: 10.1016/j.isci.2023.106045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/18/2022] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Cancer cells coordinate the mTORC1 signals and the related metabolic pathways to robustly and rapidly grow in response to nutrient conditions. Although a CNC-family transcription factor NRF3 promotes cancer development, the biological relevance between NRF3 function and mTORC1 signals in cancer cells remains unknown. Hence, we showed that NRF3 contributes to cancer cell viability through mTORC1 activation in response to amino acids, particularly arginine. NRF3 induced SLC38A9 and RagC expression for the arginine-dependent mTORC1 recruitment onto lysosomes, and it also enhanced RAB5-mediated bulk macropinocytosis and SLC7A1-mediated selective transport for arginine loading into lysosomes. Besides, the inhibition of the NRF3-mTORC1 axis impaired mitochondrial function, leading to cancer cell apoptosis. Consistently, the aberrant upregulation of the axis caused tumor growth and poor prognosis. In conclusion, this study sheds light on the unique function of NRF3 in arginine-dependent mTORC1 activation and the pathophysiological aspects of the NRF3-mTORC1 axis in cancer development.
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Affiliation(s)
- Shuuhei Hirose
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan,Research Fellow of Japan Society for the Promotion of Science
| | - Tsuyoshi Waku
- Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan,Corresponding author
| | - Misato Tani
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Haruka Masuda
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Keiko Endo
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
| | - Sanae Ashitani
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
| | - Iori Aketa
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Hina Kitano
- Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan
| | - Sota Nakada
- Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan
| | - Ayaka Wada
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Atsushi Hatanaka
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Tsuyoshi Osawa
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
| | - Akira Kobayashi
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan,Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan,Corresponding author
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Li Q, Hoppe T. Role of amino acid metabolism in mitochondrial homeostasis. Front Cell Dev Biol 2023; 11:1127618. [PMID: 36923249 PMCID: PMC10008872 DOI: 10.3389/fcell.2023.1127618] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 02/16/2023] [Indexed: 03/03/2023] Open
Abstract
Mitochondria are central hubs for energy production, metabolism and cellular signal transduction in eukaryotic cells. Maintenance of mitochondrial homeostasis is important for cellular function and survival. In particular, cellular metabolic state is in constant communication with mitochondrial homeostasis. One of the most important metabolic processes that provide energy in the cell is amino acid metabolism. Almost all of the 20 amino acids that serve as the building blocks of proteins are produced or degraded in the mitochondria. The synthesis of the amino acids aspartate and arginine depends on the activity of the respiratory chain, which is essential for cell proliferation. The degradation of branched-chain amino acids mainly occurs in the mitochondrial matrix, contributing to energy metabolism, mitochondrial biogenesis, as well as protein quality control in both mitochondria and cytosol. Dietary supplementation or restriction of amino acids in worms, flies and mice modulates lifespan and health, which has been associated with changes in mitochondrial biogenesis, antioxidant response, as well as the activity of tricarboxylic acid cycle and respiratory chain. Consequently, impaired amino acid metabolism has been associated with both primary mitochondrial diseases and diseases with mitochondrial dysfunction such as cancer. Here, we present recent observations on the crosstalk between amino acid metabolism and mitochondrial homeostasis, summarise the underlying molecular mechanisms to date, and discuss their role in cellular functions and organismal physiology.
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Affiliation(s)
- Qiaochu Li
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Thorsten Hoppe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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Regué L, Wang W, Ji F, Avruch J, Wang H, Dai N. Human T2D-Associated Gene IMP2/IGF2BP2 Promotes the Commitment of Mesenchymal Stem Cells Into Adipogenic Lineage. Diabetes 2023; 72:33-44. [PMID: 36219823 PMCID: PMC9797317 DOI: 10.2337/db21-1087] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 10/06/2022] [Indexed: 01/19/2023]
Abstract
Excessive adiposity is the main cause of obesity and type two diabetes (T2D). Variants in human IMP2/IGF2BP2 gene are associated with increased risk of T2D. However, little is known about its role in adipogenesis and in insulin resistance. Here, we investigate the function of IMP2 during adipocyte development. Mice with Imp2 deletion in mesenchymal stem cells (MSC) are resistant to diet-induced obesity without glucose and insulin tolerance affected. Imp2 is essential for the early commitment of adipocyte-derived stem cells (ADSC) into preadipocytes, but the deletion of Imp2 in MSC is not required for the proliferation and terminal differentiation of committed preadipocytes. Mechanistically, Imp2 binds Wnt receptor Fzd8 mRNA and promotes its degradation by recruiting CCR4-NOT deadenylase complex in an mTOR-dependent manner. Our data demonstrate that Imp2 is required for maintaining white adipose tissue homeostasis through controlling mRNA stability in ADSC. However, the contribution of IMP2 to insulin resistance, a main risk of T2D, is not evident.
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Affiliation(s)
- Laura Regué
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA
- Diabetes Unit of the Medical Services, Massachusetts General Hospital, Boston, MA
- Department of Medicine, Harvard Medical School, Boston, MA
| | - William Wang
- The Lundquist Institute, Torrance, CA
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Fei Ji
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA
- Department of Medicine, Harvard Medical School, Boston, MA
| | - Joseph Avruch
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA
- Diabetes Unit of the Medical Services, Massachusetts General Hospital, Boston, MA
- Department of Medicine, Harvard Medical School, Boston, MA
| | - Hua Wang
- The Lundquist Institute, Torrance, CA
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Ning Dai
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA
- Diabetes Unit of the Medical Services, Massachusetts General Hospital, Boston, MA
- Department of Medicine, Harvard Medical School, Boston, MA
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Han X, Goh KY, Lee WX, Choy SM, Tang HW. The Importance of mTORC1-Autophagy Axis for Skeletal Muscle Diseases. Int J Mol Sci 2022; 24:297. [PMID: 36613741 PMCID: PMC9820406 DOI: 10.3390/ijms24010297] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) complex 1, mTORC1, integrates nutrient and growth factor signals with cellular responses and plays critical roles in regulating cell growth, proliferation, and lifespan. mTORC1 signaling has been reported as a central regulator of autophagy by modulating almost all aspects of the autophagic process, including initiation, expansion, and termination. An increasing number of studies suggest that mTORC1 and autophagy are critical for the physiological function of skeletal muscle and are involved in diverse muscle diseases. Here, we review recent insights into the essential roles of mTORC1 and autophagy in skeletal muscles and their implications in human muscle diseases. Multiple inhibitors targeting mTORC1 or autophagy have already been clinically approved, while others are under development. These chemical modulators that target the mTORC1/autophagy pathways represent promising potentials to cure muscle diseases.
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Affiliation(s)
- Xujun Han
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Kah Yong Goh
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Wen Xing Lee
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Sze Mun Choy
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Hong-Wen Tang
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
- Division of Cellular & Molecular Research, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore 169610, Singapore
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Shimada T, Yamagata K. Spine morphogenesis and synapse formation in tubular sclerosis complex models. Front Mol Neurosci 2022; 15:1019343. [PMID: 36606143 PMCID: PMC9807618 DOI: 10.3389/fnmol.2022.1019343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is caused by mutations in the Tsc1 or Tsc2 genes, whose products form a complex and inactivate the small G-protein Rheb1. The activation of Rheb1 may cause refractory epilepsy, intellectual disability, and autism, which are the major neuropsychiatric manifestations of TSC. Abnormalities in dendritic spines and altered synaptic structure are hallmarks of epilepsy, intellectual disability, and autism. In addition, spine dysmorphology and aberrant synapse formation are observed in TSC animal models. Therefore, it is important to investigate the molecular mechanism underlying the regulation of spine morphology and synapse formation in neurons to identify therapeutic targets for TSC. In this review, we focus on the representative proteins regulated by Rheb1 activity, mTORC1 and syntenin, which are pivotal downstream factors of Rheb1 in the alteration of spine formation and synapse function in TSC neurons.
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Affiliation(s)
- Tadayuki Shimada
- Child Brain Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan,*Correspondence: Tadayuki Shimada,
| | - Kanato Yamagata
- Child Brain Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan,Department of Psychiatry, Takada Nishishiro Hospital, Niigata, Japan,Kanato Yamagata,
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Yan Y, Chen C, Li Z, Zhang J, Park N, Qu CK. Extracellular arginine is required but the arginine transporter CAT3 (Slc7a3) is dispensable for mouse normal and malignant hematopoiesis. Sci Rep 2022; 12:21832. [PMID: 36528691 PMCID: PMC9759514 DOI: 10.1038/s41598-022-24554-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 11/16/2022] [Indexed: 12/23/2022] Open
Abstract
Amino acid-mediated metabolism is one of the key catabolic and anabolic processes involved in diverse cellular functions. However, the role of the semi-essential amino acid arginine in normal and malignant hematopoietic cell development is poorly understood. Here we report that a continuous supply of exogenous arginine is required for the maintenance/function of normal hematopoietic stem cells (HSCs). Surprisingly, knockout of Slc7a3 (CAT3), a major L-arginine transporter, does not affect HSCs in steady-state or under stress. Although Slc7a3 is highly expressed in naïve and activated CD8 T cells, neither T cell development nor activation/proliferation is impacted by Slc7a3 depletion. Furthermore, the Slc7a3 deletion does not attenuate leukemia development driven by Pten loss or the oncogenic Ptpn11E76K mutation. Arginine uptake assays reveal that L-arginine uptake is not disrupted in Slc7a3 knockout cells. These data suggest that extracellular arginine is critically important for HSCs, but CAT3 is dispensable for normal hematopoiesis and leukemogenesis.
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Affiliation(s)
- Yuhan Yan
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Winship Cancer Institute, Children’s Healthcare of Atlanta, Emory University School of Medicine, 1760 Haygood Drive NE, HSRB E302, Atlanta, GA 30322 USA
| | - Chao Chen
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Winship Cancer Institute, Children’s Healthcare of Atlanta, Emory University School of Medicine, 1760 Haygood Drive NE, HSRB E302, Atlanta, GA 30322 USA
| | - Zhiguo Li
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Winship Cancer Institute, Children’s Healthcare of Atlanta, Emory University School of Medicine, 1760 Haygood Drive NE, HSRB E302, Atlanta, GA 30322 USA
| | - Jing Zhang
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Winship Cancer Institute, Children’s Healthcare of Atlanta, Emory University School of Medicine, 1760 Haygood Drive NE, HSRB E302, Atlanta, GA 30322 USA
| | - Narin Park
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Winship Cancer Institute, Children’s Healthcare of Atlanta, Emory University School of Medicine, 1760 Haygood Drive NE, HSRB E302, Atlanta, GA 30322 USA
| | - Cheng-Kui Qu
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Winship Cancer Institute, Children’s Healthcare of Atlanta, Emory University School of Medicine, 1760 Haygood Drive NE, HSRB E302, Atlanta, GA 30322 USA
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Wang G, Chen L, Qin S, Zheng Y, Xia C, Yao J, Wang P, Deng L. Cystine Induced-mTORC2 Activation through Promoting Sin1 Phosphorylation to Suppress Cancer Cell Ferroptosis. Mol Nutr Food Res 2022; 66:e2200186. [PMID: 36189894 DOI: 10.1002/mnfr.202200186] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 09/19/2022] [Indexed: 01/18/2023]
Abstract
SCOPE Mechanistic target of rapamycin (mTOR) serves as a central signaling node in the coordination of cell growth and metabolism, and it functions via two distinct complexes, namely, mTOR complex 1 (mTORC1) and mTORC2. mTORC1 plays a crucial role in sensing amino acids, whereas mTORC2 involves in sensing growth factors. However, it remains largely unclear whether mTORC2 can sense amino acids and the mechanism by which amino acids regulate mTORC2 has not been studied. METHODS AND RESULTS After treating cells with indicated concentration of amino acids for different time, it is found that the mTORC2 activation is significantly increased in response to amino acids stimulation, especially cystine. Particularly, knockdown solute carrier family 7 member 11 (SLC7A11) by siRNA shows that SLC7A11-mediated cystine uptake is responsible for activating mTORC2. Mechanistically, the study finds that p38 is activated in response to cystine stimulation, and co-immunoprecipitation (Co-IP) experiments suggest that p38 regulates the assembly of components within mTORC2 by mediating the phosphorylation of the mTORC2 subunit mitogen-activated protein kinase-interacting protein 1 (Sin1) in a cystine-dependent manner. Finally, combined with inducers and inhibitors of ferroptosis and cell viability assay, the study observes that cystine-mediated regulation of the p38-Sin1-mTOR-AKT pathway induces resistance to ferroptosis. CONCLUSION These results indicate that cystine-induced activation of the p38-Sin1-mTORC2-AKT pathway suppresses ferroptosis.
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Affiliation(s)
- GuoYan Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lei Chen
- Division of Laboratory Safety and Services, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - SenLin Qin
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - YiNing Zheng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chao Xia
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - JunHu Yao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ping Wang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Lu Deng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Wang D, Wan X. Progress in research on the role of amino acid metabolic reprogramming in tumour therapy: A review. Biomed Pharmacother 2022; 156:113923. [DOI: 10.1016/j.biopha.2022.113923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/16/2022] [Accepted: 10/24/2022] [Indexed: 11/26/2022] Open
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Correia B, Sousa MI, Branco AF, Rodrigues AS, Ramalho-Santos J. Leucine and Arginine Availability Modulate Mouse Embryonic Stem Cell Proliferation and Metabolism. Int J Mol Sci 2022; 23:ijms232214286. [PMID: 36430764 PMCID: PMC9694364 DOI: 10.3390/ijms232214286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/19/2022] Open
Abstract
Amino acids are crucial nutrients involved in several cellular and physiological processes, including fertilization and early embryo development. In particular, Leucine and Arginine have been shown to stimulate implantation, as lack of both in a blastocyst culture system is able to induce a dormant state in embryos. The aim of this work was to evaluate the effects of Leucine and Arginine withdrawal on pluripotent mouse embryonic stem cell status, notably, their growth, self-renewal, as well as glycolytic and oxidative metabolism. Our results show that the absence of both Leucine and Arginine does not affect mouse embryonic stem cell pluripotency, while reducing cell proliferation through cell-cycle arrest. Importantly, these effects are not related to Leukemia Inhibitory Factor (LIF) and are reversible when both amino acids are reconstituted in the culture media. Moreover, a lack of these amino acids is related to a reduction in glycolytic and oxidative metabolism and decreased protein translation in mouse embryonic stem cells (mESCs), while maintaining their pluripotent status.
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Affiliation(s)
- Bibiana Correia
- Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
- CNC—Center for Neuroscience and Cell Biology, CIBB, University of Coimbra, Azinhaga de Santa Comba, Polo 3, 3000-354 Coimbra, Portugal
| | - Maria Inês Sousa
- Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
- CNC—Center for Neuroscience and Cell Biology, CIBB, University of Coimbra, Azinhaga de Santa Comba, Polo 3, 3000-354 Coimbra, Portugal
| | - Ana Filipa Branco
- CNC—Center for Neuroscience and Cell Biology, CIBB, University of Coimbra, Azinhaga de Santa Comba, Polo 3, 3000-354 Coimbra, Portugal
| | - Ana Sofia Rodrigues
- CNC—Center for Neuroscience and Cell Biology, CIBB, University of Coimbra, Azinhaga de Santa Comba, Polo 3, 3000-354 Coimbra, Portugal
| | - João Ramalho-Santos
- Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
- CNC—Center for Neuroscience and Cell Biology, CIBB, University of Coimbra, Azinhaga de Santa Comba, Polo 3, 3000-354 Coimbra, Portugal
- Correspondence:
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Crater JM, Nixon DF, Furler O’Brien RL. HIV-1 replication and latency are balanced by mTOR-driven cell metabolism. Front Cell Infect Microbiol 2022; 12:1068436. [PMID: 36467738 PMCID: PMC9712982 DOI: 10.3389/fcimb.2022.1068436] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 11/02/2022] [Indexed: 11/19/2022] Open
Abstract
Human Immunodeficiency virus type 1 (HIV-1) relies on host cell metabolism for all aspects of viral replication. Efficient HIV-1 entry, reverse transcription, and integration occurs in activated T cells because HIV-1 proteins co-opt host metabolic pathways to fuel the anabolic requirements of virion production. The HIV-1 viral life cycle is especially dependent on mTOR, which drives signaling and metabolic pathways required for viral entry, replication, and latency. As a central regulator of host cell metabolism, mTOR and its downstream effectors help to regulate the expression of enzymes within the glycolytic and pentose phosphate pathways along with other metabolic pathways regulating amino acid uptake, lipid metabolism, and autophagy. In HIV-1 pathogenesis, mTOR, in addition to HIF-1α and Myc signaling pathways, alter host cell metabolism to create an optimal environment for viral replication. Increased glycolysis and pentose phosphate pathway activity are required in the early stages of the viral life cycle, such as providing sufficient dNTPs for reverse transcription. In later stages, fatty acid synthesis is required for creating cholesterol and membrane lipids required for viral budding. Epigenetics of the provirus fueled by metabolism and mTOR signaling likewise controls active and latent infection. Acetyl-CoA and methyl group abundance, supplied by the TCA cycle and amino acid uptake respectively, may regulate latent infection and reactivation. Thus, understanding and exploring new connections between cellular metabolism and HIV-1 pathogenesis may yield new insights into the latent viral reservoirs and fuel novel treatments and cure strategies.
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Affiliation(s)
| | | | - Robert L. Furler O’Brien
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, United States
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66
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Scarpin MR, Simmons CH, Brunkard JO. Translating across kingdoms: target of rapamycin promotes protein synthesis through conserved and divergent pathways in plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7016-7025. [PMID: 35770874 PMCID: PMC9664230 DOI: 10.1093/jxb/erac267] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
mRNA translation is the growth rate-limiting step in genome expression. Target of rapamycin (TOR) evolved a central regulatory role in eukaryotes as a signaling hub that monitors nutrient availability to maintain homeostasis and promote growth, largely by increasing the rate of translation initiation and protein synthesis. The dynamic pathways engaged by TOR to regulate translation remain debated even in well-studied yeast and mammalian models, however, despite decades of intense investigation. Recent studies have firmly established that TOR also regulates mRNA translation in plants through conserved mechanisms, such as the TOR-LARP1-5'TOP signaling axis, and through pathways specific to plants. Here, we review recent advances in our understanding of the regulation of mRNA translation in plants by TOR.
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Affiliation(s)
- M Regina Scarpin
- Laboratory of Genetics, University of Wisconsin, Madison, WI, USA
- Department of Plant and Microbial Biology, University of California, Berkeley,CA, USA
- Plant Gene Expression Center, USDA Agricultural Research Service, Albany, CA, USA
| | - Carl H Simmons
- Laboratory of Genetics, University of Wisconsin, Madison, WI, USA
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67
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Ma Q, Yang Q, Xu J, Zhang X, Kim D, Liu Z, Da Q, Mao X, Zhou Y, Cai Y, Pareek V, Kim HW, Wu G, Dong Z, Song WL, Gan L, Zhang C, Hong M, Benkovic SJ, Weintraub NL, Fulton D, Asara JM, Ben-Sahra I, Huo Y. ATIC-Associated De Novo Purine Synthesis Is Critically Involved in Proliferative Arterial Disease. Circulation 2022; 146:1444-1460. [PMID: 36073366 PMCID: PMC9643655 DOI: 10.1161/circulationaha.121.058901] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 08/05/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Proliferation of vascular smooth muscle cells (VSMCs) is a hallmark of arterial diseases, especially in arterial restenosis after angioplasty or stent placement. VSMCs reprogram their metabolism to meet the increased requirements of lipids, proteins, and nucleotides for their proliferation. De novo purine synthesis is one of critical pathways for nucleotide synthesis. However, its role in proliferation of VSMCs in these arterial diseases has not been defined. METHODS De novo purine synthesis in proliferative VSMCs was evaluated by liquid chromatography-tandem mass spectrometry. The expression of ATIC (5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase), the critical bifunctional enzyme in the last 2 steps of the de novo purine synthesis pathway, was assessed in VSMCs of proliferative arterial neointima. Global and VSMC-specific knockout of Atic mice were generated and used for examining the role of ATIC-associated purine metabolism in the formation of arterial neointima and atherosclerotic lesions. RESULTS In this study, we found that de novo purine synthesis was increased in proliferative VSMCs. Upregulated purine synthesis genes, including ATIC, were observed in the neointima of the injured vessels and atherosclerotic lesions both in mice and humans. Global or specific knockout of Atic in VSMCs inhibited cell proliferation, attenuating the arterial neointima in models of mouse atherosclerosis and arterial restenosis. CONCLUSIONS These results reveal that de novo purine synthesis plays an important role in VSMC proliferation in arterial disease. These findings suggest that targeting ATIC is a promising therapeutic approach to combat arterial diseases.
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Affiliation(s)
- Qian Ma
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Qiuhua Yang
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Jiean Xu
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Xiaoyu Zhang
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - David Kim
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Zhiping Liu
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Qingen Da
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Xiaoxiao Mao
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Yaqi Zhou
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Yongfeng Cai
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Vidhi Pareek
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, PA 16802, USA
| | - Ha Won Kim
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Wen-liang Song
- Department of Medicine, Vanderbilt University, Nashville, TN 37232, USA
| | - Lin Gan
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Chunxiang Zhang
- Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou 646000, China
| | - Mei Hong
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Stephen J. Benkovic
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, PA 16802, USA
| | - Neal L Weintraub
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - David Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
| | - Issam Ben-Sahra
- Department of Biochemistry and Molecular Genetics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - Yuqing Huo
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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Huang C, Li L, Wang L, Bao J, Zhang X, Yan J, Wu J, Cao N, Wang J, Zhao L, Liu X, Yu X, Zhu X, Lin F. The Amino Acid Permease MoGap1 Regulates TOR Activity and Autophagy in Magnaporthe oryzae. Int J Mol Sci 2022; 23:13663. [PMID: 36362450 PMCID: PMC9655246 DOI: 10.3390/ijms232113663] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 08/26/2023] Open
Abstract
Rice is an important food crop all over the world. It can be infected by the rice blast fungus Magnaporthe oryzae, which results in a significant reduction in rice yield. The infection mechanism of M. oryzae has been an academic focus for a long time. It has been found that G protein, AMPK, cAMP-PKA, and MPS1-MAPK pathways play different roles in the infection process. Recently, the function of TOR signaling in regulating cell growth and autophagy by receiving nutritional signals generated by plant pathogenic fungi has been demonstrated, but its regulatory mechanism in response to the nutritional signals remains unclear. In this study, a yeast amino acid permease homologue MoGap1 was identified and a knockout mutant of MoGap1 was successfully obtained. Through a phenotypic analysis, a stress analysis, autophagy flux detection, and a TOR activity analysis, we found that the deletion of MoGap1 led to a sporulation reduction as well as increased sensitivity to cell wall stress and carbon source stress in M. oryzae. The ΔMogap1 mutant showed high sensitivity to the TOR inhibitor rapamycin. A Western blot analysis further confirmed that the TOR activity significantly decreased, which improved the level of autophagy. The results suggested that MoGap1, as an upstream regulator of TOR signaling, regulated autophagy and responded to adversities such as cell wall stress by regulating the TOR activity.
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Affiliation(s)
- Changli Huang
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Lin Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Lei Wang
- College of Advanced Agricultural Sciences, Zhejiang Agriculture and Forest University, Hangzhou 310007, China
| | - Jiandong Bao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Xiaozhi Zhang
- College of Advanced Agricultural Sciences, Zhejiang Agriculture and Forest University, Hangzhou 310007, China
| | - Jiongyi Yan
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Jiaqi Wu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Na Cao
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Jiaoyu Wang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
- College of Advanced Agricultural Sciences, Zhejiang Agriculture and Forest University, Hangzhou 310007, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Lili Zhao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Xiaohong Liu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Xiaoping Yu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Xueming Zhu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
- College of Advanced Agricultural Sciences, Zhejiang Agriculture and Forest University, Hangzhou 310007, China
| | - Fucheng Lin
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
- College of Advanced Agricultural Sciences, Zhejiang Agriculture and Forest University, Hangzhou 310007, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
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Noel MS, Kim S, Hartley ML, Wong S, Picozzi V, Staszewski H, Kim DW, Van Tornout JM, Philip PA, Chung V, Ocean AJ, Wang‐Gillam A. A randomized phase II study of SM-88 plus methoxsalen, phenytoin, and sirolimus in patients with metastatic pancreatic cancer treated in the second line and beyond. Cancer Med 2022; 11:4169-4181. [PMID: 35499204 PMCID: PMC9678093 DOI: 10.1002/cam4.4768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/11/2022] [Accepted: 04/10/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This trial explores SM-88 used with methoxsalen, phenytoin, and sirolimus (MPS) in pretreated metastatic pancreatic ductal adenocarcinoma (mPDAC) METHODS: Forty-nine patients were randomized to daily 460 or 920 mg oral SM-88 with MPS (SM-88 Regimen). The primary endpoint was objective response rate (RECIST 1.1). RESULTS Thirty-seven patients completed ≥ one cycle of SM-88 Regimen (response evaluable population). Disease control rate (DCR), overall survival (OS), and progression-free survival (PFS) did not differ significantly between dose levels. Stable disease was achieved in 9/37 patients (DCR, 24.3%); there were no complete or partial responses. Quality-of-life (QOL) was maintained and trended in favor of 920 mg. SM-88 Regimen was well tolerated; a single patient (1/49) had related grade 3 and 4 adverse events, which later resolved. In the intention-to-treat population of 49 patients, the median overall survival (mOS) was 3.4 months (95% CI: 2.7-4.9 months). Those treated in the second line had an mOS of 8.1 months and a median PFS of 3.8 months. Survival was higher for patients with stable versus progressive disease (any line; mOS: 10.6 months vs. 3.9 months; p = 0.01). CONCLUSIONS SM-88 Regimen has a favorable safety profile with encouraging QOL effects, disease control, and survival trends. This regimen should be explored in the second-line treatment of patients with mPDAC. CLINICALTRIALS gov Identifier: NCT03512756.
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Affiliation(s)
- Marcus S. Noel
- Georgetown Lombardi Comprehensive Cancer CenterWashingtonDistrict of ColumbiaUSA
| | - Semmie Kim
- TYME Technologies Inc.BedminsterNew JerseyUSA
| | - Marion L. Hartley
- The Ruesch Center for the Cure of Gastrointestinal CancersWashingtonDistrict of ColumbiaUSA
| | - Steve Wong
- Sarcoma Oncology Research CenterSanta MonicaCaliforniaUSA
| | | | | | - Dae Won Kim
- The University of Texas MD Anderson Cancer CenterHoustonTexasUSA
| | | | - Philip Agop Philip
- Karmanos Cancer CenterWayne State UniversityMichiganDetroitUSA
- SWOGFarmington HillsMichiganUSA
| | | | - Allyson J. Ocean
- Weill Cornell MedicineNew York‐Presbyterian HospitalNew YorkNew YorkUSA
| | - Andrea Wang‐Gillam
- Washington University School of Medicine in St. LouisSt. LouisMissouriUSA
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van Tartwijk FW, Kaminski CF. Protein Condensation, Cellular Organization, and Spatiotemporal Regulation of Cytoplasmic Properties. Adv Biol (Weinh) 2022; 6:e2101328. [PMID: 35796197 DOI: 10.1002/adbi.202101328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 05/15/2022] [Indexed: 01/28/2023]
Abstract
The cytoplasm is an aqueous, highly crowded solution of active macromolecules. Its properties influence the behavior of proteins, including their folding, motion, and interactions. In particular, proteins in the cytoplasm can interact to form phase-separated assemblies, so-called biomolecular condensates. The interplay between cytoplasmic properties and protein condensation is critical in a number of functional contexts and is the subject of this review. The authors first describe how cytoplasmic properties can affect protein behavior, in particular condensate formation, and then describe the functional implications of this interplay in three cellular contexts, which exemplify how protein self-organization can be adapted to support certain physiological phenotypes. The authors then describe the formation of RNA-protein condensates in highly polarized cells such as neurons, where condensates play a critical role in the regulation of local protein synthesis, and describe how different stressors trigger extensive reorganization of the cytoplasm, both through signaling pathways and through direct stress-induced changes in cytoplasmic properties. Finally, the authors describe changes in protein behavior and cytoplasmic properties that may occur in extremophiles, in particular organisms that have adapted to inhabit environments of extreme temperature, and discuss the implications and functional importance of these changes.
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Affiliation(s)
- Francesca W van Tartwijk
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
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Zhang X, Deng Y, Hu S, Hu X, Ma J, Hu J, Hu B, He H, Li L, Liu H, Wang J. Comparative analysis of amino acid content and protein synthesis-related genes expression levels in breast muscle among different duck breeds/strains. Poult Sci 2022; 102:102277. [PMID: 36410066 PMCID: PMC9678761 DOI: 10.1016/j.psj.2022.102277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 11/15/2022] Open
Abstract
Evidences have found important effects of breeds/strains on the content of amino acids (AAs) which is an important substrate for protein synthesis and contributes greatly to meat quality. Therefore, the objective of the present study was to compare the AAs content and protein synthesis-related genes expression levels in breast muscle of native breed (Jianchang duck (J)), hybrid strains (BH1, BH2, and MC♂ × (BGF2♂ × GF2♀)♀ (MC)), and commercial breed (Cherry Verry duck). Results showed that a total of 17 AAs (TAAs) was detected from breast muscle among 5 duck breeds/strains including 11 essential AAs (EAAs). Among these AAs, the contents of Proline, Threonine, Glutamine, Serine, Methionine, Phenylalanine, Histidine, and Cysteine were significant difference among 5 duck breeds/strains. The contents of EAAs, TAAs, and flavor AAs were higher in breast muscle of J and BH2 than those in other duck breeds/strains, and the ratio of EAAs/TAAs was higher in breast muscle of BH2. Furthermore, the expression levels of eukaryotic translation initiation factor 4E-binding protein 1, mammalian target of rapamycin, and proton-coupled amino acid transporter 1 were the highest in breast muscle of BH2, and that of solute carrier family 38 member 2 was the highest in breast muscle of J. Meanwhile, principal component analysis results showed that principal component 1 of BH1, principal component 3 of BH2, and principal component 2 of MC were positively corelated with EAAs/TAAs, and principal component 1 was positively correlated with flavor AAs and EAAs. In conclusion, compared to BH1, MC, and Cherry Verry duck, AA content was higher in breast muscle of BH2 and J, which might be associated with the higher expression levels of mammalian target of rapamycin, eukaryotic translation initiation factor 4E-binding protein 1, and proton-coupled amino acid transporter 1 in breast muscle of BH2 and solute carrier family 38 member 2 in breast muscle of J. The comparative analysis of AA content in breast muscle among different duck breeds/strains could provide an important basis for improving the nutritional value of duck meat in the breeding process.
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Affiliation(s)
- Xin Zhang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Yan Deng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Shenqiang Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Xinyue Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Jiaming Ma
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Jiwei Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Bo Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Hua He
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Liang Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Hehe Liu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Jiwen Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Chengdu Campus, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China.
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72
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Nishikubo K, Ohgaki R, Okanishi H, Okuda S, Xu M, Endou H, Kanai Y. Pharmacologic inhibition of LAT1 predominantly suppresses transport of large neutral amino acids and downregulates global translation in cancer cells. J Cell Mol Med 2022; 26:5246-5256. [PMID: 36071551 PMCID: PMC9575050 DOI: 10.1111/jcmm.17553] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/12/2022] [Accepted: 08/30/2022] [Indexed: 11/29/2022] Open
Abstract
L‐type amino acid transporter 1 (LAT1; SLC7A5), which preferentially transports large neutral amino acids, is highly upregulated in various cancers. LAT1 supplies cancer cells with amino acids as substrates for enhanced biosynthetic and bioenergetic reactions and stimulates signalling networks involved in the regulation of survival, growth and proliferation. LAT1 inhibitors show anti‐cancer effects and a representative compound, JPH203, is under clinical evaluation. However, pharmacological impacts of LAT1 inhibition on the cellular amino acid transport and the translational activity in cancer cells that are conceptually pivotal for its anti‐proliferative effect have not been elucidated yet. Here, we demonstrated that JPH203 drastically inhibits the transport of all the large neutral amino acids in pancreatic ductal adenocarcinoma cells. The inhibitory effects of JPH203 were observed even in competition with high concentrations of amino acids in a cell culture medium. The analyses of the nutrient‐sensing mTORC1 and GAAC pathways and the protein synthesis activity revealed that JPH203 downregulates the global translation. This study demonstrates a predominant contribution of LAT1 to the transport of large neutral amino acids in cancer cells and the suppression of protein synthesis by JPH203 supposed to underly its broad anti‐proliferative effects across various types of cancer cells.
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Affiliation(s)
- Kou Nishikubo
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Ryuichi Ohgaki
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan
| | - Hiroki Okanishi
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Suguru Okuda
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.,Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Minhui Xu
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | | | - Yoshikatsu Kanai
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan
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73
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Hong PP, Li C, Niu GJ, Zhao XF, Wang JX. White spot syndrome virus directly activates mTORC1 signaling to facilitate its replication via polymeric immunoglobulin receptor-mediated infection in shrimp. PLoS Pathog 2022; 18:e1010808. [PMID: 36067252 PMCID: PMC9481175 DOI: 10.1371/journal.ppat.1010808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 09/16/2022] [Accepted: 08/11/2022] [Indexed: 11/19/2022] Open
Abstract
Previous studies have shown that the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway has antiviral functions or is beneficial for viral replication, however, the detail mechanisms by which mTORC1 enhances viral infection remain unclear. Here, we found that proliferation of white spot syndrome virus (WSSV) was decreased after knockdown of mTor (mechanistic target of rapamycin) or injection inhibitor of mTORC1, rapamycin, in Marsupenaeus japonicus, which suggests that mTORC1 is utilized by WSSV for its replication in shrimp. Mechanistically, WSSV infects shrimp by binding to its receptor, polymeric immunoglobulin receptor (pIgR), and induces the interaction of its intracellular domain with Calmodulin. Calmodulin then promotes the activation of protein kinase B (AKT) by interaction with the pleckstrin homology (PH) domain of AKT. Activated AKT phosphorylates mTOR and results in the activation of the mTORC1 signaling pathway to promote its downstream effectors, ribosomal protein S6 kinase (S6Ks), for viral protein translation. Moreover, mTORC1 also phosphorylates eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1), which will result in the separation of 4EBP1 from eukaryotic translation initiation factor 4E (eIF4E) for the translation of viral proteins in shrimp. Our data revealed a novel pathway for WSSV proliferation in shrimp and indicated that mTORC1 may represent a potential clinical target for WSSV control in shrimp aquaculture. White spot syndrome virus (WSSV) is the causative pathogen of white spot disease (WSD) and represents the most destructive viral disease of shrimp. The virus has evolved various strategies to escape from host defenses or exploit host biological pathways for its reproduction. Studies on viral immune-escape mechanisms can provide new strategies for disease prevention and control in shrimp aquaculture. Mechanistic target of rapamycin (mTOR) plays a central role in the regulation of cell growth and metabolism, which nucleates two distinct protein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) with diverse functions at different levels of the signaling pathway. mTORC1 is reported to be exploited by viruses in their reproduction. However, the detail mechanism remains unclear. In this study, we identified a new mechanism of mTOR being hijacked by WSSV in shrimp (Marsupenaeus japonicus). WSSV infects shrimp by its receptor, pIgR and induces the interaction of the intracellular domain of pIgR with Calmodulin. Calmodulin subsequently promotes the activation of AKT by interaction with the pleckstrin homology domain of the kinase. Activated AKT phosphorylates mTOR and results in the activation of the mTORC1 signaling pathway to promote its downstream effectors, S6Ks, for viral protein synthesis. Moreover, mTORC1 also phosphorylates 4EBP1, which results in the separation of 4EBP1 from eIF4E for the translation of viral proteins in shrimp. Our study reveals a novel strategy for WSSV proliferation in shrimp and indicates that the components of mTORC1 may represent potential clinical targets for WSSV control in shrimp aquaculture.
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Affiliation(s)
- Pan-Pan Hong
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong, China
| | - Cang Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong, China
| | - Guo-Juan Niu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong, China
| | - Xiao-Fan Zhao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong, China
| | - Jin-Xing Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong, China
- * E-mail:
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74
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A Rag GTPase dimer code defines the regulation of mTORC1 by amino acids. Nat Cell Biol 2022; 24:1394-1406. [PMID: 36097072 PMCID: PMC9481461 DOI: 10.1038/s41556-022-00976-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 07/13/2022] [Indexed: 12/14/2022]
Abstract
Amino acid availability controls mTORC1 activity via a heterodimeric Rag GTPase complex that functions as a scaffold at the lysosomal surface, bringing together mTORC1 with its activators and effectors. Mammalian cells express four Rag proteins (RagA–D) that form dimers composed of RagA/B bound to RagC/D. Traditionally, the Rag paralogue pairs (RagA/B and RagC/D) are referred to as functionally redundant, with the four dimer combinations used interchangeably in most studies. Here, by using genetically modified cell lines that express single Rag heterodimers, we uncover a Rag dimer code that determines how amino acids regulate mTORC1. First, RagC/D differentially define the substrate specificity downstream of mTORC1, with RagD promoting phosphorylation of its lysosomal substrates TFEB/TFE3, while both Rags are involved in the phosphorylation of non-lysosomal substrates such as S6K. Mechanistically, RagD recruits mTORC1 more potently to lysosomes through increased affinity to the anchoring LAMTOR complex. Furthermore, RagA/B specify the signalling response to amino acid removal, with RagB-expressing cells maintaining lysosomal and active mTORC1 even upon starvation. Overall, our findings reveal key qualitative differences between Rag paralogues in the regulation of mTORC1, and underscore Rag gene duplication and diversification as a potentially impactful event in mammalian evolution. Gollwitzer, Grützmacher et al. and Figlia et al. establish that the various Rag GTPase genes and isoforms differentially regulate mTORC1 activity and distinctly modulate the responsiveness of mammalian cells to amino acid availability.
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75
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Yuskaitis CJ, Modasia JB, Schrötter S, Rossitto LA, Groff KJ, Morici C, Mithal DS, Chakrabarty RP, Chandel NS, Manning BD, Sahin M. DEPDC5-dependent mTORC1 signaling mechanisms are critical for the anti-seizure effects of acute fasting. Cell Rep 2022; 40:111278. [PMID: 36044864 PMCID: PMC9508617 DOI: 10.1016/j.celrep.2022.111278] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/11/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
Caloric restriction and acute fasting are known to reduce seizures but through unclear mechanisms. mTOR signaling has been suggested as a potential mechanism for seizure protection from fasting. We demonstrate that brain mTORC1 signaling is reduced after acute fasting of mice and that neuronal mTORC1 integrates GATOR1 complex-mediated amino acid and tuberous sclerosis complex (TSC)-mediated growth factor signaling. Neuronal mTORC1 is most sensitive to withdrawal of leucine, arginine, and glutamine, which are dependent on DEPDC5, a component of the GATOR1 complex. Metabolomic analysis reveals that Depdc5 neuronal-specific knockout mice are resistant to sensing significant fluctuations in brain amino acid levels after fasting. Depdc5 neuronal-specific knockout mice are resistant to the protective effects of fasting on seizures or seizure-induced death. These results establish that acute fasting reduces seizure susceptibility in a DEPDC5-dependent manner. Modulation of nutrients upstream of GATOR1 and mTORC1 could offer a rational therapeutic strategy for epilepsy treatment.
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Affiliation(s)
- Christopher J Yuskaitis
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jinita B Modasia
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sandra Schrötter
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Leigh-Ana Rossitto
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Karenna J Groff
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christopher Morici
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Divakar S Mithal
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Section of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Ram P Chakrabarty
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Navdeep S Chandel
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Brendan D Manning
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Mustafa Sahin
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Boston, MA, USA.
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76
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Yamamura J, Ma S, Jia H, Kato H. Activating transcription factor 4-dependent hsa-miR-663a transcription mediates mTORC1/p70S6K1 signaling underleucine deprivation. Front Nutr 2022; 9:965771. [PMID: 35990342 PMCID: PMC9389164 DOI: 10.3389/fnut.2022.965771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/15/2022] [Indexed: 11/15/2022] Open
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is involved in nutrient-induced signaling and is a master regulator of cell growth and metabolism. Amino acid-deficient conditions affect mTORC1 activity; however, its upstream regulators warrant further investigation. MicroRNAs are key regulators of nutrient-related responses; therefore, the present study aimed to assess the leucine starvation-induced microRNA profile and its impact on mTORC1 activity. Transcriptome analysis of human hepatocellular carcinoma cells (HepG2) under leucine deprivation revealed that hsa-miR-663a and hsa-miR-1469 were altered in a transcription factor 4-dependent manner. Overexpression of these microRNAs induced phosphorylation of the ribosomal protein S6 kinase beta-1, a mTORC1 downstream target. Furthermore, hsa-miR-663a downregulated proline-rich Akt1 substrate of 40 kDa (PRAS40), one of the mTORC1 components. In summary, this study provides new insights into the regulatory role of microRNAs in amino acid metabolism and demonstrates alterations in microRNA profile under leucine deprivation in human hepatocytes.
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Affiliation(s)
- Junki Yamamura
- Health Nutrition, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Sihui Ma
- Health Nutrition, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Huijuan Jia
- Health Nutrition, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hisanori Kato
- Health Nutrition, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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77
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Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) senses nutrient levels in the cell and based on the availability, regulates cellular growth and proliferation. Its activity is tightly modulated by two GTPase units, the Rag GTPases and the Rheb GTPase. The Rag GTPases are the central hub of amino acid sensing as they summarize the amino acid signals from upstream regulators and control the subcellular localization of mTORC1. Unique from canonical signaling GTPases, the Rag GTPases are obligatory heterodimers, and the two subunits coordinate their nucleotide loading states to regulate their functional states. Robust biochemical analysis is indispensable to understanding the molecular mechanism governing the GTPase cycle. This chapter discusses protocols for purifying and biochemically characterizing the Rag GTPase heterodimer. We described two purification protocols to recombinantly produce the Rag GTPase heterodimer in large quantities. We then described assays to quantitatively measure the nucleotide binding and hydrolysis by the Rag GTPases. These assays allow for a thorough investigation of this unique heterodimeric GTPase, and they could be applicable to investigations of other noncanonical GTPases.
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Affiliation(s)
- Dylan D Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, United States.
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78
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Loos CMM, McLeod KR, Vanzant ES, Stratton SA, Bohannan AD, Coleman RJ, van Doorn DA, Urschel KL. Differential effect of two dietary protein sources on time course response of muscle anabolic signaling pathways in normal and insulin dysregulated horses. Front Vet Sci 2022; 9:896220. [PMID: 35978710 PMCID: PMC9376591 DOI: 10.3389/fvets.2022.896220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022] Open
Abstract
The objective of the study was to characterize the temporal changes of phosphorylation patterns of mTOR signaling proteins in response to two dietary protein sources in insulin dysregulated (ID, n = 8) and non-ID (n = 8) horses. Horses were individually housed and fed timothy grass hay and 2 daily concentrate meals so that protein was the first limiting nutrient and the total diet provided 120% of daily DE requirements for maintenance. On sample days, horses randomly received 0.25 g CP/kg BW of a pelleted alfalfa (AP) or commercial protein supplement (PS). Blood samples were collected before and 30, 60, 90, 120, 150, 180, 210, 240, 300, 360, 420, and 480 min post feeding and analyzed for plasma glucose, insulin and amino acid (AA) concentrations. Gluteus Medius muscle samples were obtained before and 90, 180, and 300 min after feeding and analyzed for relative abundance of phosphorylated mTOR pathway components using western immunoblot analysis. There was no effect of protein source on postprandial glucose and insulin responses (P ≥ 0.14) but consumption of PS elicited a 2 times larger AUC for essential AA (EAA), greater peak concentrations of EAA and a shorter time to reach peak EAA concentrations compared to AP. Abundance of phosphorylated mTOR (P = 0.08) and rpS6 (P = 0.10) tended to be ~1.5-fold greater after consumption of PS at 90 min compared to AP. Dephosphorylation patterns differed between protein sources and was slower for AP compared to PS. ID horses had a 2 times greater (P = 0.009) AUC and 3 times higher postprandial peak concentrations (P < 0.0001) for insulin compared to non-ID horses after consumption of both treatment pellets, but EAA responses were similar between groups (P = 0.53). Insulin status did not affect rpS6 or mTOR phosphorylation after consumption of either protein source (P ≥ 0.35), but phosphorylated rpS6 abundance was twice as high in ID compared to non-ID horses (P = 0.007). These results suggest that the consumption of higher quality protein sources may result in greater postprandial activation of the mTOR pathway compared to equal amounts of a forage-based protein source. Moreover, ID does not impair postprandial activation of mTOR and rpS6 proteins in horses following a protein-rich meal.
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Affiliation(s)
- Caroline M. M. Loos
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
- *Correspondence: Caroline M. M. Loos
| | - Kyle R. McLeod
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - Eric S. Vanzant
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - Sophie A. Stratton
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - Adam D. Bohannan
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - Robert J. Coleman
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | | | - Kristine L. Urschel
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
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79
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Eskandari SK, Allos H, Al Dulaijan BS, Melhem G, Sulkaj I, Alhaddad JB, Saad AJ, Deban C, Chu P, Choi JY, Kollar B, Pomahac B, Riella LV, Berger SP, Sanders JSF, Lieberman J, Li L, Azzi JR. mTORC1 Inhibition Protects Human Regulatory T Cells From Granzyme-B-Induced Apoptosis. Front Immunol 2022; 13:899975. [PMID: 35757726 PMCID: PMC9229986 DOI: 10.3389/fimmu.2022.899975] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 05/05/2022] [Indexed: 01/17/2023] Open
Abstract
Regulatory T cells (Tregs) have shown great promise as a means of cellular therapy in a multitude of allo- and auto-immune diseases—due in part to their immunosuppressive potency. Nevertheless, the clinical efficacy of human Tregs in patients has been limited by their poor in vivo homeostasis. To avert apoptosis, Tregs require stable antigenic (CD3ζ/T-cell-receptor-mediated), co-stimulatory (CD28-driven), and cytokine (IL-2-dependent) signaling. Notably, this sequence of signals supports an activated Treg phenotype that includes a high expression of granzymes, particularly granzyme B (GrB). Previously, we have shown that aside from the functional effects of GrB in lysing target cells to modulate allo-immunity, GrB can leak out of the intracellular lysosomal granules of host Tregs, initiating pro-apoptotic pathways. Here, we assessed the role of inhibiting mechanistic target of rapamycin complex 1 (mTORC1), a recently favored drug target in the transplant field, in regulating human Treg apoptosis via GrB. Using ex vivo models of human Treg culture and a humanized mouse model of human skin allotransplantation, we found that by inhibiting mTORC1 using rapamycin, intracytoplasmic expression and functionality of GrB diminished in host Tregs; lowering human Treg apoptosis by in part decreasing the phosphorylation of S6K and c-Jun. These findings support the already clinically validated effects of mTORC1 inhibition in patients, most notably their stabilization of Treg bioactivity and in vivo homeostasis.
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Affiliation(s)
- Siawosh K Eskandari
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.,Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Hazim Allos
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Basmah S Al Dulaijan
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Gandolina Melhem
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Ina Sulkaj
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.,Graduate Program in Immunology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Juliano B Alhaddad
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Anis J Saad
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Christa Deban
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Philip Chu
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - John Y Choi
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Branislav Kollar
- Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.,Department of Plastic and Hand Surgery, University of Freiburg Medical Center, Medical Faculty of the University of Freiburg, Freiburg, Germany
| | - Bohdan Pomahac
- Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.,Division of Plastic and Reconstructive Surgery, Smilow Cancer Hospital, Yale School of Medicine, New Haven, CT, United States
| | - Leonardo V Riella
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.,Center of Transplantation Sciences, Division of Nephrology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Stefan P Berger
- Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Jan S F Sanders
- Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Judy Lieberman
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States.,Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, United States
| | - Li Li
- Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Jamil R Azzi
- Transplantation Research Center, Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.,Division of Nephrology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
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80
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Yue S, Li G, He S, Li T. The central role of mTORC1 in amino acid sensing. Cancer Res 2022; 82:2964-2974. [PMID: 35749594 DOI: 10.1158/0008-5472.can-21-4403] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/28/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
The mechanistic target of rapamycin (mTOR) is a master regulator of cell growth that controls cell homeostasis in response to nutrients, growth factors, and other environmental cues. Recent studies have emphasized the importance of lysosomes as a hub for nutrient sensing, especially amino acid sensing by mTORC1. This review highlights recent advances in understanding the amino acid-mTORC1 signaling axis and the role of mTORC1 in cancer.
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81
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Wang J, Eming SA, Ding X. Role of mTOR Signaling Cascade in Epidermal Morphogenesis and Skin Barrier Formation. BIOLOGY 2022; 11:biology11060931. [PMID: 35741452 PMCID: PMC9220260 DOI: 10.3390/biology11060931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/13/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary The skin epidermis is a stratified multilayered epithelium that provides a life-sustaining protective and defensive barrier for our body. The barrier machinery is established and maintained through a tightly regulated keratinocyte differentiation program. Under normal conditions, the basal layer keratinocytes undergo active proliferation and migration upward, differentiating into the suprabasal layer cells. Perturbation of the epidermal differentiation program often results in skin barrier defects and inflammatory skin disorders. The protein kinase mechanistic target of rapamycin (mTOR) is the central hub of cell growth, metabolism and nutrient signaling. Over the past several years, we and others using transgenic mouse models have unraveled that mTOR signaling is critical for epidermal differentiation and barrier formation. On the other hand, there is increasing evidence that disturbed activation of mTOR signaling is significantly implicated in the development of various skin diseases. In this review, we focus on the formation of skin barrier and discuss the current understanding on how mTOR signaling networks, including upstream inputs, kinases and downstream effectors, regulate epidermal differentiation and skin barrier formation. We hope this review will help us better understand the metabolic signaling in the epidermis, which may open new vistas for epidermal barrier defect-associated disease therapy. Abstract The skin epidermis, with its capacity for lifelong self-renewal and rapid repairing response upon injury, must maintain an active status in metabolism. Mechanistic target of rapamycin (mTOR) signaling is a central controller of cellular growth and metabolism that coordinates diverse physiological and pathological processes in a variety of tissues and organs. Recent evidence with genetic mouse models highlights an essential role of the mTOR signaling network in epidermal morphogenesis and barrier formation. In this review, we focus on the recent advances in understanding how mTOR signaling networks, including upstream inputs, kinases and downstream effectors, regulate epidermal morphogenesis and skin barrier formation. Understanding the details of the metabolic signaling will be critical for the development of novel pharmacological approaches to promote skin barrier regeneration and to treat epidermal barrier defect-associated diseases.
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Affiliation(s)
- Juan Wang
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People’s Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China;
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China
| | - Sabine A. Eming
- Department of Dermatology, University of Cologne, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
- Institute of Zoology, Developmental Biology Unit, University of Cologne, 50674 Cologne, Germany
- Correspondence: (S.A.E.); (X.D.); Tel.: +86-137-6457-1130 (X.D.)
| | - Xiaolei Ding
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People’s Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China;
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China
- Department of Dermatology, University of Cologne, 50937 Cologne, Germany
- Correspondence: (S.A.E.); (X.D.); Tel.: +86-137-6457-1130 (X.D.)
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82
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Meng D, Yang Q, Jeong MH, Curukovic A, Tiwary S, Melick CH, Lama-Sherpa TD, Wang H, Huerta-Rosario M, Urquhart G, Zacharias LG, Lewis C, DeBerardinis RJ, Jewell JL. SNAT7 regulates mTORC1 via macropinocytosis. Proc Natl Acad Sci U S A 2022; 119:e2123261119. [PMID: 35561222 PMCID: PMC9171778 DOI: 10.1073/pnas.2123261119] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/13/2022] [Indexed: 11/30/2022] Open
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) senses amino acids to control cell growth, metabolism, and autophagy. Some amino acids signal to mTORC1 through the Rag GTPase, whereas glutamine and asparagine activate mTORC1 through a Rag GTPase-independent pathway. Here, we show that the lysosomal glutamine and asparagine transporter SNAT7 activates mTORC1 after extracellular protein, such as albumin, is macropinocytosed. The N terminus of SNAT7 forms nutrient-sensitive interaction with mTORC1 and regulates mTORC1 activation independently of the Rag GTPases. Depletion of SNAT7 inhibits albumin-induced mTORC1 lysosomal localization and subsequent activation. Moreover, SNAT7 is essential to sustain KRAS-driven pancreatic cancer cell growth through mTORC1. Thus, SNAT7 links glutamine and asparagine signaling from extracellular protein to mTORC1 independently of the Rag GTPases and is required for macropinocytosis-mediated mTORC1 activation and pancreatic cancer cell growth.
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Affiliation(s)
- Delong Meng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Qianmei Yang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Mi-Hyeon Jeong
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Adna Curukovic
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Shweta Tiwary
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Chase H. Melick
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Tshering D. Lama-Sherpa
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Huanyu Wang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Mariela Huerta-Rosario
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Greg Urquhart
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Lauren G. Zacharias
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Cheryl Lewis
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ralph J. DeBerardinis
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jenna L. Jewell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
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83
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Paulusma CC, Lamers W, Broer S, van de Graaf SFJ. Amino acid metabolism, transport and signalling in the liver revisited. Biochem Pharmacol 2022; 201:115074. [PMID: 35568239 DOI: 10.1016/j.bcp.2022.115074] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 11/02/2022]
Abstract
The liver controls the systemic exposure of amino acids entering via the gastro-intestinal tract. For most amino acids except branched chain amino acids, hepatic uptake is very efficient. This implies that the liver orchestrates amino acid metabolism and also controls systemic amino acid exposure. Although many amino acid transporters have been identified, cloned and investigated with respect to substrate specificity, transport mechanism, and zonal distribution, which of these players are involved in hepatocellular amino acid transport remains unclear. Here, we aim to provide a review of current insight into the molecular machinery of hepatic amino acid transport. Furthermore, we place this information in a comprehensive overview of amino acid transport, signalling and metabolism.
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Affiliation(s)
- Coen C Paulusma
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands; Department of Gastroenterology and Hepatology, Amsterdam University Medical Centers, Amsterdam, Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Wouter Lamers
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands; Department of Gastroenterology and Hepatology, Amsterdam University Medical Centers, Amsterdam, Netherlands; Department of Anatomy & Embryology, Maastricht University, Maastricht, The Netherlands
| | - Stefan Broer
- Department of Gastroenterology and Hepatology, Amsterdam University Medical Centers, Amsterdam, Netherlands; Research School of Biology, Australian National University, Canberra, Australia
| | - Stan F J van de Graaf
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands; Department of Gastroenterology and Hepatology, Amsterdam University Medical Centers, Amsterdam, Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam University Medical Centers, Amsterdam, The Netherlands; Department of Anatomy & Embryology, Maastricht University, Maastricht, The Netherlands.
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84
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Khor ES, Noor SM, Wong PF. MiR-107 inhibits the sprouting of intersegmental vessels of zebrafish embryos. PROTOPLASMA 2022; 259:691-702. [PMID: 34368895 DOI: 10.1007/s00709-021-01695-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
MicroRNAs (miRNAs) play important roles in various biological processes. Our previous study showed that inhibition of MTOR with rapamycin treatment suppressed human endothelial cell tube formation, concomitant with the down-regulation of miR-107. Similarly, inhibition of Ztor by rapamycin also suppressed vascular development in zebrafish embryos. To gain a better understanding of the role of miR-107 and MTOR in vascular development, the present study sought to validate its function by over-expressing miR-107 in zebrafish embryos via microinjection with mimic miR-107 duplexes. Alkaline phosphatase (ALP) staining was used to visualise blood vessels in the zebrafish embryo, and expressions of Pten, Ztor and Rap1 were investigated by immunoblotting. Over-expression of miR-107 in zebrafish embryos inhibited the sprouting of intersegmental vessels (ISVs) with concomitant down-regulation of phosphorylated Rps6 expression, which confirmed the inhibition of Ztor signalling. As expected, pten, which is the target of miR-107, was down-regulated. Interestingly, Rap1, a small GTPase protein that is involved in intersomitic vessels sprouting during angiogenesis, was also down-regulated when miR-107 was over-expressed. Overall, our findings suggest that miR-107 and Ztor-mediated suppression of vascular development in zebrafish embryo involves Rap1.
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Affiliation(s)
- Eng-Soon Khor
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Suzita Mohd Noor
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Pooi-Fong Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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85
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Buel GR, Dang H, Asara JM, Blenis J, Mutvei AP. Prolonged deprivation of arginine or leucine induces PI3K/Akt-dependent reactivation of mTORC1. J Biol Chem 2022; 298:102030. [PMID: 35577075 PMCID: PMC9194872 DOI: 10.1016/j.jbc.2022.102030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/05/2022] [Accepted: 05/08/2022] [Indexed: 01/08/2023] Open
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86
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Melick CH, Lama-Sherpa TD, Curukovic A, Jewell JL. G-Protein Coupled Receptor Signaling and Mammalian Target of Rapamycin Complex 1 Regulation. Mol Pharmacol 2022; 101:181-190. [PMID: 34965982 PMCID: PMC9092479 DOI: 10.1124/molpharm.121.000302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 11/29/2021] [Indexed: 11/30/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) senses upstream stimuli to regulate numerous cellular functions such as metabolism, growth, and autophagy. Increased activation of mTOR complex 1 (mTORC1) is typically observed in human disease and continues to be an important therapeutic target. Understanding the upstream regulators of mTORC1 will provide a crucial link in targeting hyperactivated mTORC1 in human disease. In this mini-review, we will discuss the regulation of mTORC1 by upstream stimuli, with a specific focus on G-protein coupled receptor signaling to mTORC1. SIGNIFICANCE STATEMENT: mTORC1 is a master regulator of many cellular processes and is often hyperactivated in human disease. Therefore, understanding the molecular underpinnings of G-protein coupled receptor signaling to mTORC1 will undoubtedly be beneficial for human disease.
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Affiliation(s)
- Chase H Melick
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Tshering D Lama-Sherpa
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Adna Curukovic
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jenna L Jewell
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
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87
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Freitas EDS, Katsanos CS. (Dys)regulation of Protein Metabolism in Skeletal Muscle of Humans With Obesity. Front Physiol 2022; 13:843087. [PMID: 35350688 PMCID: PMC8957804 DOI: 10.3389/fphys.2022.843087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/07/2022] [Indexed: 01/22/2023] Open
Abstract
Studies investigating the proteome of skeletal muscle present clear evidence that protein metabolism is altered in muscle of humans with obesity. Moreover, muscle quality (i.e., strength per unit of muscle mass) appears lower in humans with obesity. However, relevant evidence to date describing the protein turnover, a process that determines content and quality of protein, in muscle of humans with obesity is quite inconsistent. This is due, at least in part, to heterogeneity in protein turnover in skeletal muscle of humans with obesity. Although not always evident at the mixed-muscle protein level, the rate of synthesis is generally lower in myofibrillar and mitochondrial proteins in muscle of humans with obesity. Moreover, alterations in the synthesis of protein in muscle of humans with obesity are manifested more readily under conditions that stimulate protein synthesis in muscle, including the fed state, increased plasma amino acid availability to muscle, and exercise. Current evidence supports various biological mechanisms explaining impairments in protein synthesis in muscle of humans with obesity, but this evidence is rather limited and needs to be reproduced under more defined experimental conditions. Expanding our current knowledge with direct measurements of protein breakdown in muscle, and more importantly of protein turnover on a protein by protein basis, will enhance our understanding of how obesity modifies the proteome (content and quality) in muscle of humans with obesity.
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Affiliation(s)
| | - Christos S Katsanos
- School of Life Sciences, Arizona State University, Tempe, AZ, United States.,Department of Physiology and Biomedical Engineering, Mayo Clinic in Arizona, Scottsdale, AZ, United States
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88
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Choi W, Kim J, Ko JW, Choi A, Kwon YH. Effects of maternal branched-chain amino acid and alanine supplementation on growth and biomarkers of protein metabolism in dams fed a low-protein diet and their offspring. Amino Acids 2022; 54:977-988. [PMID: 35353249 DOI: 10.1007/s00726-022-03157-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/13/2022] [Indexed: 11/24/2022]
Abstract
A considerable number of studies have reported that maternal protein restriction may disturb fetal growth and organ development due to a lower availability of amino acids. Leucine, one of branched-chain amino acid (BCAA) promotes protein synthesis through mechanistic target of rapamycin signaling. Here, we investigated the effects of BCAA supplementation in the dams fed a low-protein diet on serum and hepatic biochemical parameters of protein metabolism of dams and their offspring. Female ICR mice were fed a control (20% casein), a low-protein (10% casein), a low-protein with 2% BCAAs or a low-protein with 2% alanine diet for 2 weeks before mating and then throughout pregnancy and lactation. Alanine was used as an amino nitrogen control for the BCAA. Dams and their male offspring were sacrificed at postnatal day 21. There were no changes in body weight and fat mass in low-protein fed dams; however, BCAA supplementation significantly increased fat mass and serum leptin levels. Low-protein diet consumption reduced maternal protein synthesis based on biochemical analysis of serum albumin and hepatic protein levels and immunoblotting of S6 protein, which were increased by BCAA and alanine supplementation. Offspring from dams fed a low-protein diet exhibited lower body and organ weights. Body weight and hepatic protein levels of the offspring were increased by alanine supplementation. However, the decreased serum biochemical parameters, including glucose, triglyceride, total protein and albumin levels in the low-protein offspring group were not changed in response to BCAA or alanine supplementation. A reduced density of the hepatic vessel system in the offspring from dams fed a low-protein diet was restored in the offspring from dams fed either BCAA and alanine-supplemented diet. These results suggest that supplementation of amino nitrogen per se may be responsible for inducing hepatic protein synthesis in the dams fed a low-protein diet and alleviating the distorted growth and liver development of their offspring.
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Affiliation(s)
- Wooseon Choi
- Department of Food and Nutrition, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.,Department of Pharmacology, The Catholic University of Korea, Seoul, 06591, South Korea
| | - Juhae Kim
- Department of Food and Nutrition, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Je Won Ko
- Department of Food and Nutrition, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Alee Choi
- Department of Food and Nutrition, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Young Hye Kwon
- Department of Food and Nutrition, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea. .,Research Institute of Human Ecology, Seoul National University, Seoul, South Korea.
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89
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Huan J, Grivas P, Birch J, Hansel DE. Emerging Roles for Mammalian Target of Rapamycin (mTOR) Complexes in Bladder Cancer Progression and Therapy. Cancers (Basel) 2022; 14:1555. [PMID: 35326708 PMCID: PMC8946148 DOI: 10.3390/cancers14061555] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/03/2022] [Accepted: 03/15/2022] [Indexed: 12/15/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) pathway regulates important cellular functions. Aberrant activation of this pathway, either through upstream activation by growth factors, loss of inhibitory controls, or molecular alterations, can enhance cancer growth and progression. Bladder cancer shows high levels of mTOR activity in approximately 70% of urothelial carcinomas, suggesting a key role for this pathway in this cancer. mTOR signaling initiates through upstream activation of phosphatidylinositol 3 kinase (PI3K) and protein kinase B (AKT) and results in activation of either mTOR complex 1 (mTORC1) or mTOR complex 2 (mTORC2). While these complexes share several key protein components, unique differences in their complex composition dramatically alter the function and downstream cellular targets of mTOR activity. While significant work has gone into analysis of molecular alterations of the mTOR pathway in bladder cancer, this has not yielded significant benefit in mTOR-targeted therapy approaches in urothelial carcinoma to date. New discoveries regarding signaling convergence onto mTOR complexes in bladder cancer could yield unique insights the biology and targeting of this aggressive disease. In this review, we highlight the functional significance of mTOR signaling in urothelial carcinoma and its potential impact on future therapy implications.
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Affiliation(s)
- Jianya Huan
- Department of Pathology & Laboratory Medicine, Oregon Health & Science University, Portland, OR 97239, USA; (J.H.); (J.B.)
| | - Petros Grivas
- Division of Medical Oncology, Department of Medicine, University of Washington School of Medicine, Fred Hutchinson Cancer Research Center, Seattle Cancer Care Alliance, Seattle, WA 98195, USA;
| | - Jasmine Birch
- Department of Pathology & Laboratory Medicine, Oregon Health & Science University, Portland, OR 97239, USA; (J.H.); (J.B.)
| | - Donna E. Hansel
- Department of Pathology & Laboratory Medicine, Oregon Health & Science University, Portland, OR 97239, USA; (J.H.); (J.B.)
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90
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Pinel K, Heraud C, Morin G, Dias K, Marcé A, Beauclair L, Fontagné-Dicharry S, Masagounder K, Klünemann M, Seiliez I, Beaumatin F. Are the Main Methionine Sources Equivalent? A Focus on DL-Methionine and DL-Methionine Hydroxy Analog Reveals Differences on Rainbow Trout Hepatic Cell Lines Functions. Int J Mol Sci 2022; 23:2935. [PMID: 35328356 PMCID: PMC8954868 DOI: 10.3390/ijms23062935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/01/2022] [Accepted: 03/05/2022] [Indexed: 01/27/2023] Open
Abstract
The replacement of fishmeal by plant proteins in aquafeeds imposes the use of synthetic methionine (MET) sources to balance the amino acid composition of alternative diets and so to meet the metabolic needs of fish of agronomic interest such as rainbow trout (RT-Oncorhynchus mykiss). Nonetheless, debates still exist to determine if one MET source is more efficiently used than another by fish. To address this question, the use of fish cell lines appeared a convenient strategy, since it allowed to perfectly control cell growing conditions notably by fully depleting MET from the media and studying which MET source is capable to restore cell growth/proliferation and metabolism when supplemented back. Thus, results of cell proliferation assays, Western blots, RT-qPCR and liquid chromatography analyses from two RT liver-derived cell lines revealed a better absorption and metabolization of DL-MET than DL-Methionine Hydroxy Analog (MHA) with the activation of the mechanistic Target Of Rapamycin (mTOR) pathway for DL-MET and the activation of integrated stress response (ISR) pathway for MHA. Altogether, the results clearly allow to conclude that both synthetic MET sources are not biologically equivalent, suggesting similar in vivo effects in RT liver and, therefore, questioning the MHA efficiencies in other RT tissues.
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Affiliation(s)
- Karine Pinel
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Cécile Heraud
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Guillaume Morin
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Karine Dias
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Annaëlle Marcé
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Linda Beauclair
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Stéphanie Fontagné-Dicharry
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Karthik Masagounder
- Evonik Operations GmbH, Rodenbacher Chaussee 4, 4D-63457 Hanau, Germany; (K.M.); (M.K.)
| | - Martina Klünemann
- Evonik Operations GmbH, Rodenbacher Chaussee 4, 4D-63457 Hanau, Germany; (K.M.); (M.K.)
| | - Iban Seiliez
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
| | - Florian Beaumatin
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France; (C.H.); (G.M.); (K.D.); (A.M.); (L.B.); (S.F.-D.); (I.S.)
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91
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Mendel ZI, Reynolds MB, Abuaita BH, O'Riordan MX, Swanson JA. Amino acids suppress macropinocytosis and promote release of CSF1 receptor in macrophages. J Cell Sci 2022; 135:jcs259284. [PMID: 35107133 PMCID: PMC8919328 DOI: 10.1242/jcs.259284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/31/2021] [Indexed: 01/12/2023] Open
Abstract
The internalization of solutes by macropinocytosis provides an essential route for nutrient uptake in many cells. Macrophages increase macropinocytosis in response to growth factors and other stimuli. To test the hypothesis that nutrient environments modulate solute uptake by macropinocytosis, this study analyzed the effects of extracellular amino acids on the accumulation of fluorescent fluid-phase probes in murine macrophages. Nine amino acids, added individually or together, were capable of suppressing macropinocytosis in murine bone marrow-derived macrophages stimulated with the growth factors colony stimulating factor 1 (CSF1) or interleukin 34, both ligands of the CSF1 receptor (CSF1R). The suppressive amino acids did not inhibit macropinocytosis in response to lipopolysaccharide, the chemokine CXCL12, or the tumor promoter phorbol myristate acetate. Suppressive amino acids promoted release of CSF1R from cells and resulted in the formation of smaller macropinosomes in response to CSF1. This suppression of growth factor-stimulated macropinocytosis indicates that different nutrient environments modulate CSF1R levels and bulk ingestion by macropinocytosis, with likely consequences for macrophage growth and function.
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Affiliation(s)
- Zachary I. Mendel
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109,USA
| | - Mack B. Reynolds
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109,USA
- Graduate Program in Immunology, University of Michigan Medical School, Ann Arbor, MI 48109,USA
| | - Basel H. Abuaita
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109,USA
| | - Mary X. O'Riordan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109,USA
| | - Joel A. Swanson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109,USA
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92
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A Long Journey before Cycling: Regulation of Quiescence Exit in Adult Muscle Satellite Cells. Int J Mol Sci 2022; 23:ijms23031748. [PMID: 35163665 PMCID: PMC8836154 DOI: 10.3390/ijms23031748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 01/28/2022] [Accepted: 01/30/2022] [Indexed: 02/04/2023] Open
Abstract
Skeletal muscle harbors a pool of stem cells called muscle satellite cells (MuSCs) that are mainly responsible for its robust regenerative capacities. Adult satellite cells are mitotically quiescent in uninjured muscles under homeostasis, but they exit quiescence upon injury to re-enter the cell cycle to proliferate. While most of the expanded satellites cells differentiate and fuse to form new myofibers, some undergo self-renewal to replenish the stem cell pool. Specifically, quiescence exit describes the initial transition of MuSCs from quiescence to the first cell cycle, which takes much longer than the time required for subsequent cell cycles and involves drastic changes in cell size, epigenetic and transcriptomic profiles, and metabolic status. It is, therefore, an essential period indispensable for the success of muscle regeneration. Diverse mechanisms exist in MuSCs to regulate quiescence exit. In this review, we summarize key events that occur during quiescence exit in MuSCs and discuss the molecular regulation of this process with an emphasis on multiple levels of intrinsic regulatory mechanisms. A comprehensive understanding of how quiescence exit is regulated will facilitate satellite cell-based muscle regenerative therapies and advance their applications in various disease and aging conditions.
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93
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Novel Repositioning Therapy for Drug-Resistant Glioblastoma: In Vivo Validation Study of Clindamycin Treatment Targeting the mTOR Pathway and Combination Therapy with Temozolomide. Cancers (Basel) 2022; 14:cancers14030770. [PMID: 35159037 PMCID: PMC8833675 DOI: 10.3390/cancers14030770] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/29/2022] [Accepted: 01/30/2022] [Indexed: 02/05/2023] Open
Abstract
Simple Summary Given the significant costs and lengthy timelines of drug development and clinical trials, drug repositioning is a promising alternative to find effective treatments for brain tumors quickly and inexpensively. In the present study, using a simple drug screen of macrolides, we found that clindamycin (CLD) had cytotoxic effects on glioblastoma (GBM) cells. Further studies showed the inhibition of the mammalian target of rapamycin (mTOR) pathway as the key mechanism of action. Interestingly, we found that co-treatment with temozolomide (TMZ), the alkylating agent considered as standard therapy in GBM, enhanced these effects and proposed the inhibition of O6-methylguanine-DNA methyltransferase (MGMT) protein by CLD as a potential mechanism for this combination effect. Abstract Multimodal therapy including surgery, radiation treatment, and temozolomide (TMZ) is performed on glioblastoma (GBM). However, the prognosis is still poor and there is an urgent need to develop effective treatments to improve survival. Molecular biological analysis was conducted to examine the signal activation patterns in GBM specimens and remains an open problem. Advanced macrolides, such as azithromycin, reduce the phosphorylation of p70 ribosomal protein S6 kinase (p70S6K), a downstream mammalian target of rapamycin (mTOR) effector, and suppress the proliferation of T-cells. We focused on its unique profile and screened for the antitumor activity of approved macrolide antibiotics. Clindamycin (CLD) reduced the viability of GBM cells in vitro. We assessed the effects of the candidate macrolide on the mTOR pathway through Western blotting. CLD attenuated p70S6K phosphorylation in a dose-dependent manner. These effects on GBM cells were enhanced by co-treatment with TMZ. Furthermore, CLD inhibited the expression of the O6-methylguanine-DNA methyltransferase (MGMT) protein in cultured cells. In the mouse xenograft model, CLD and TMZ co-administration significantly suppressed the tumor growth and markedly decreased the number of Ki-67 (clone MIB-1)-positive cells within the tumor. These results suggest that CLD suppressed GBM cell growth by inhibiting mTOR signaling. Moreover, CLD and TMZ showed promising synergistic antitumor activity.
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Mechanistic/mammalian target of rapamycin and side effects of antipsychotics: insights into mechanisms and implications for therapy. Transl Psychiatry 2022; 12:13. [PMID: 35013125 PMCID: PMC8748807 DOI: 10.1038/s41398-021-01778-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/08/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022] Open
Abstract
Antipsychotic pharmacotherapy has been widely recommended as the standard of care for the treatment of acute schizophrenia and psychotic symptoms of other psychiatric disorders. However, there are growing concerns regarding antipsychotic-induced side effects, including weight gain, metabolic syndrome (MetS), and extrapyramidal motor disorders, which not only decrease patient compliance, but also predispose to diabetes and cardiovascular diseases. To date, most studies and reviews on the mechanisms of antipsychotic-induced metabolic side effects have focused on central nervous system mediation of appetite and food intake. However, disturbance in glucose and lipid metabolism, and hepatic steatosis induced by antipsychotic drugs might precede weight gain and MetS. Recent studies have demonstrated that the mechanistic/mammalian target of rapamycin (mTOR) pathway plays a critical regulatory role in the pathophysiology of antipsychotic drug-induced disorders of hepatic glucose and lipid metabolism. Furthermore, antipsychotic drugs promote striatal mTOR pathway activation that contributes to extrapyramidal motor side effects. Although recent findings have advanced the understanding of the role of the mTOR pathway in antipsychotic-induced side effects, few reviews have been conducted on this emerging topic. In this review, we synthesize key findings by focusing on the roles of the hepatic and striatal mTOR pathways in the pathogenesis of metabolic and extrapyramidal side effects, respectively. We further discuss the potential therapeutic benefits of normalizing excessive mTOR pathway activation with mTOR specific inhibitors. A deeper understanding of pathogenesis may inform future intervention strategies using the pharmacological or genetic inhibitors of mTOR to prevent and manage antipsychotic-induced side effects.
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Doxsey DD, Veinotte K, Shen K. A New Crosslinking Assay to Study Guanine Nucleotide Binding in the Gtr Heterodimer of S. cerevisiae. Small GTPases 2022; 13:327-334. [PMID: 36328771 PMCID: PMC9639563 DOI: 10.1080/21541248.2022.2141019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) complex is responsible for coordinating nutrient availability with eukaryotic cell growth. Amino acid signals are transmitted towards mTOR via the Rag/Gtr heterodimers. Due to the obligatory heterodimeric architecture of the Rag/Gtr GTPases, investigating their biochemical properties has been challenging. Here, we describe an updated assay that allows us to probe the guanine nucleotide-binding affinity and kinetics to the Gtr heterodimers in Saccharomyces cerevisiae. We first identified the structural element that Gtr2p lacks to enable crosslinking. By using a sequence conservation-based mutation, we restored the crosslinking between Gtr2p and the bound nucleotides. Using this construct, we determined the nucleotide-binding affinities of the Gtr heterodimer, and found that it operates under a different form of intersubunit communication than human Rag GTPases. Our study defines the evolutionary divergence of the Gtr/Rag-mTOR axis of nutrient sensing.
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Affiliation(s)
- Dylan D. Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA
| | - Kristen Veinotte
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA,Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation St, Worcester, MA, 01605, USA,CONTACT Kuang Shen Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA
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96
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Gietzen DW. Brain Signaling of Indispensable Amino Acid Deficiency. J Clin Med 2021; 11:191. [PMID: 35011932 PMCID: PMC8745678 DOI: 10.3390/jcm11010191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/23/2021] [Accepted: 12/27/2021] [Indexed: 12/17/2022] Open
Abstract
Our health requires continual protein synthesis for maintaining and repairing tissues. For protein synthesis to function, all the essential (indispensable) amino acids (IAAs) must be available in the diet, along with those AAs that the cells can synthesize (the dispensable amino acids). Here we review studies that have shown the location of the detector for IAA deficiency in the brain, specifically for recognition of IAA deficient diets (IAAD diets) in the anterior piriform cortex (APC), with subsequent responses in downstream brain areas. The APC is highly excitable, which makes is uniquely suited to serve as an alarm for reductions in IAAs. With a balanced diet, these neurons are kept from over-excitation by GABAergic inhibitory neurons. Because several transporters and receptors on the GABAergic neurons have rapid turnover times, they rely on intact protein synthesis to function. When an IAA is missing, its unique tRNA cannot be charged. This activates the enzyme General Control Nonderepressible 2 (GCN2) that is important in the initiation phase of protein synthesis. Without the inhibitory control supplied by GABAergic neurons, excitation in the circuitry is free to signal an urgent alarm. Studies in rodents have shown rapid recognition of IAA deficiency by quick rejection of the IAAD diet.
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Affiliation(s)
- Dorothy W Gietzen
- Department of Anatomy, Physiology and Cell Biology, University of California, Davis, CA 95616, USA
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97
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Mehrazad Saber Z, Takeuchi Y, Sawada Y, Aita Y, Ho MH, Karkoutly S, Tao D, Katabami K, Ye C, Murayama Y, Shikama A, Masuda Y, Izumida Y, Miyamoto T, Matsuzaka T, Sugasawa T, Takekoshi K, Kawakami Y, Shimano H, Yahagi N. High protein diet-induced metabolic changes are transcriptionally regulated via KLF15-dependent and independent pathways. Biochem Biophys Res Commun 2021; 582:35-42. [PMID: 34688045 DOI: 10.1016/j.bbrc.2021.10.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 01/11/2023]
Abstract
High protein diet (HPD) is an affordable and positive approach in prevention and treatment of many diseases. It is believed that transcriptional regulation is responsible for adaptation after HPD feeding and Kruppel-like factor 15 (KLF15), a zinc finger transcription factor that has been proved to perform transcriptional regulation over amino acid, lipid and glucose metabolism, is known to be involved at least in part in this HPD response. To gain more insight into molecular mechanisms by which HPD controls expressions of genes involved in amino acid metabolism in the liver, we performed RNA-seq analysis of mice fed HPD for a short period (3 days). Compared to a low protein diet, HPD feeding significantly increased hepatic expressions of enzymes involved in the breakdown of all the 20 amino acids. Moreover, using KLF15 knockout mice and in vivo Ad-luc analytical system, we were able to identify Cth (cystathionine gamma-lyase) as a new target gene of KLF15 transcription as well as Ast (aspartate aminotransferase) as an example of KLF15-independent gene despite its remarkable responsiveness to HPD. These findings provide us with a clue to elucidate the entire transcriptional regulatory mechanisms of amino acid metabolic pathways.
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Affiliation(s)
- Zahra Mehrazad Saber
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yoshinori Takeuchi
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yoshikazu Sawada
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yuichi Aita
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Man Hei Ho
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Samia Karkoutly
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Duhan Tao
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Kyoka Katabami
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Chen Ye
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yuki Murayama
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Akito Shikama
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yukari Masuda
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yoshihiko Izumida
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Takafumi Miyamoto
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Takashi Matsuzaka
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Takehito Sugasawa
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Kazuhiro Takekoshi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yasushi Kawakami
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Naoya Yahagi
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan; Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
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98
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Huang Z, Shi X, Zhou G, Li C. Dietary soy, pork and chicken proteins induce distinct nitrogen metabolism in rat liver. FOOD CHEMISTRY: MOLECULAR SCIENCES 2021; 3:100050. [PMID: 35415657 PMCID: PMC8991958 DOI: 10.1016/j.fochms.2021.100050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/30/2021] [Accepted: 10/31/2021] [Indexed: 11/14/2022]
Abstract
Dietary amino acid composition affected nitrogen metabolism in rat liver. Amino acid metabolizing enzymes were downregulated by meat protein diets. Ribosome assembly and protein synthesis were regulated by diet by mTOR pathway.
Diets have been shown to alter metabolism and gene expression. However, few data are available about changes in gene expression in liver after intake of different meat protein diets. This work aimed to explore the long-term effects of protein source on liver metabolic enzymes. Rats were fed protein diets for 90 days to study whether intake of chicken and pork protein diets promoted gene expression involved in hepatic metabolism. Liver proteome profiles were measured by iTRAQ labeling and LC–ESI–MS/MS. Chicken protein diet induced higher level of serum amino acids in rats than soy protein. Amino acid metabolizing enzymes were downregulated by pork and chicken protein diets compared with soy protein diet. Intake of meat protein diets downregulated enzymes involved in protein synthesis, disulfide bond formation, signal peptide addition, transport, localization, degradation and glycosylation modification, but upregulated enzymes involved in prolyl cis–trans isomerization for protein synthesis. Protein diets from different sources affected the amino acid supply, and further influenced ribosome assembly and protein synthesis through mTOR signaling pathway.
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99
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Calvo IA, Sharma S, Paulo JA, Gulka AO, Boeszoermenyi A, Zhang J, Lombana JM, Palmieri CM, Laviolette LA, Arthanari H, Iliopoulos O, Gygi SP, Motamedi M. The fission yeast FLCN/FNIP complex augments TORC1 repression or activation in response to amino acid (AA) availability. iScience 2021; 24:103338. [PMID: 34805795 PMCID: PMC8590082 DOI: 10.1016/j.isci.2021.103338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/10/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
The target of Rapamycin complex1 (TORC1) senses and integrates several environmental signals, including amino acid (AA) availability, to regulate cell growth. Folliculin (FLCN) is a tumor suppressor (TS) protein in renal cell carcinoma, which paradoxically activates TORC1 in response to AA supplementation. Few tractable systems for modeling FLCN as a TS are available. Here, we characterize the FLCN-containing complex in Schizosaccharomyces pombe (called BFC) and show that BFC augments TORC1 repression and activation in response to AA starvation and supplementation, respectively. BFC co-immunoprecipitates V-ATPase, a TORC1 modulator, and regulates its activity in an AA-dependent manner. BFC genetic and proteomic networks identify the conserved peptide transmembrane transporter Ptr2 and the phosphoribosylformylglycinamidine synthase Ade3 as new AA-dependent regulators of TORC1. Overall, these data ascribe an additional repressive function to Folliculin in TORC1 regulation and reveal S. pombe as an excellent system for modeling the AA-dependent, FLCN-mediated repression of TORC1 in eukaryotes.
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Affiliation(s)
- Isabel A. Calvo
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
| | - Shalini Sharma
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
| | - Joao A. Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Alexander O.D. Gulka
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
| | - Andras Boeszoermenyi
- Department of Biochemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
- Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Jingyu Zhang
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
| | - Jose M. Lombana
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
| | - Christina M. Palmieri
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
| | - Laura A. Laviolette
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
| | - Haribabu Arthanari
- Department of Biochemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
- Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Othon Iliopoulos
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
- Division of Hematology-Oncology, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Steven P. Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Mo Motamedi
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine Harvard Medical School, Charlestown, MA 02129, USA
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100
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Zhang S, Lin X, Hou Q, Hu Z, Wang Y, Wang Z. Regulation of mTORC1 by amino acids in mammalian cells: A general picture of recent advances. ACTA ACUST UNITED AC 2021; 7:1009-1023. [PMID: 34738031 PMCID: PMC8536509 DOI: 10.1016/j.aninu.2021.05.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 05/13/2021] [Accepted: 05/18/2021] [Indexed: 12/11/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) integrates various types of signal inputs, such as energy, growth factors, and amino acids to regulate cell growth and proliferation mainly through the 2 direct downstream targets, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and ribosomal protein S6 kinase 1 (S6K1). Most of the signal arms upstream of mTORC1 including energy status, stress signals, and growth factors converge on the tuberous sclerosis complex (TSC) - Ras homologue enriched in brain (Rheb) axis. Amino acids, however, are distinct from other signals and modulate mTORC1 using a unique pathway. In recent years, the transmission mechanism of amino acid signals upstream of mTORC1 has been gradually elucidated, and some sensors or signal transmission pathways for individual amino acids have also been discovered. With the help of these findings, we propose a general picture of recent advances, which demonstrates that various amino acids from lysosomes, cytoplasm, and Golgi are sensed by their respective sensors. These signals converge on mTORC1 and form a huge and complicated signal network with multiple synergies, antagonisms, and feedback mechanisms.
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Affiliation(s)
- Shizhe Zhang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Xueyan Lin
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Qiuling Hou
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Zhiyong Hu
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Yun Wang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Zhonghua Wang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
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